xref: /titanic_41/usr/src/uts/common/inet/udp/udp.c (revision ebd1706e95186ddae1d4c0d63c47544cf33832ee)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /* Copyright (c) 1990 Mentat Inc. */
27 
28 #pragma ident	"%Z%%M%	%I%	%E% SMI"
29 
30 const char udp_version[] = "%Z%%M%	%I%	%E% SMI";
31 
32 #include <sys/types.h>
33 #include <sys/stream.h>
34 #include <sys/dlpi.h>
35 #include <sys/pattr.h>
36 #include <sys/stropts.h>
37 #include <sys/strlog.h>
38 #include <sys/strsun.h>
39 #define	_SUN_TPI_VERSION 2
40 #include <sys/tihdr.h>
41 #include <sys/timod.h>
42 #include <sys/tiuser.h>
43 #include <sys/ddi.h>
44 #include <sys/sunddi.h>
45 #include <sys/strsubr.h>
46 #include <sys/suntpi.h>
47 #include <sys/xti_inet.h>
48 #include <sys/cmn_err.h>
49 #include <sys/kmem.h>
50 #include <sys/policy.h>
51 #include <sys/ucred.h>
52 #include <sys/zone.h>
53 
54 #include <sys/socket.h>
55 #include <sys/sockio.h>
56 #include <sys/vtrace.h>
57 #include <sys/debug.h>
58 #include <sys/isa_defs.h>
59 #include <sys/random.h>
60 #include <netinet/in.h>
61 #include <netinet/ip6.h>
62 #include <netinet/icmp6.h>
63 #include <netinet/udp.h>
64 #include <net/if.h>
65 #include <net/route.h>
66 
67 #include <inet/common.h>
68 #include <inet/ip.h>
69 #include <inet/ip_impl.h>
70 #include <inet/ip6.h>
71 #include <inet/ip_ire.h>
72 #include <inet/ip_if.h>
73 #include <inet/ip_multi.h>
74 #include <inet/mi.h>
75 #include <inet/mib2.h>
76 #include <inet/nd.h>
77 #include <inet/optcom.h>
78 #include <inet/snmpcom.h>
79 #include <inet/kstatcom.h>
80 #include <inet/udp_impl.h>
81 #include <inet/ipclassifier.h>
82 #include <inet/ipsec_impl.h>
83 #include <inet/ipp_common.h>
84 
85 /*
86  * The ipsec_info.h header file is here since it has the definition for the
87  * M_CTL message types used by IP to convey information to the ULP. The
88  * ipsec_info.h needs the pfkeyv2.h, hence the latters presence.
89  */
90 #include <net/pfkeyv2.h>
91 #include <inet/ipsec_info.h>
92 
93 /*
94  * Synchronization notes:
95  *
96  * UDP uses a combination of its internal perimeter, a global lock and
97  * a set of bind hash locks to protect its data structures.  Please see
98  * the note above udp_mode_assertions for details about the internal
99  * perimeter.
100  *
101  * When a UDP endpoint is bound to a local port, it is inserted into
102  * a bind hash list.  The list consists of an array of udp_fanout_t buckets.
103  * The size of the array is controlled by the udp_bind_fanout_size variable.
104  * This variable can be changed in /etc/system if the default value is
105  * not large enough.  Each bind hash bucket is protected by a per bucket
106  * lock.  It protects the udp_bind_hash and udp_ptpbhn fields in the udp_t
107  * structure.  An UDP endpoint is removed from the bind hash list only
108  * when it is being unbound or being closed.  The per bucket lock also
109  * protects a UDP endpoint's state changes.
110  *
111  * Plumbing notes:
112  *
113  * Both udp and ip are merged, but the streams plumbing is kept unchanged
114  * in that udp is always pushed atop /dev/ip.  This is done to preserve
115  * backwards compatibility for certain applications which rely on such
116  * plumbing geometry to do things such as issuing I_POP on the stream
117  * in order to obtain direct access to /dev/ip, etc.
118  *
119  * All UDP processings happen in the /dev/ip instance; the udp module
120  * instance does not possess any state about the endpoint, and merely
121  * acts as a dummy module whose presence is to keep the streams plumbing
122  * appearance unchanged.  At open time /dev/ip allocates a conn_t that
123  * happens to embed a udp_t.  This stays dormant until the time udp is
124  * pushed, which indicates to /dev/ip that it must convert itself from
125  * an IP to a UDP endpoint.
126  *
127  * We only allow for the following plumbing cases:
128  *
129  * Normal:
130  *	/dev/ip is first opened and later udp is pushed directly on top.
131  *	This is the default action that happens when a udp socket or
132  *	/dev/udp is opened.  The conn_t created by /dev/ip instance is
133  *	now shared and is marked with IPCL_UDP.
134  *
135  * SNMP-only:
136  *	udp is pushed on top of a module other than /dev/ip.  When this
137  *	happens it will support only SNMP semantics.  A new conn_t is
138  *	allocated and marked with IPCL_UDPMOD.
139  *
140  * The above cases imply that we don't support any intermediate module to
141  * reside in between /dev/ip and udp -- in fact, we never supported such
142  * scenario in the past as the inter-layer communication semantics have
143  * always been private.  Also note that the normal case allows for SNMP
144  * requests to be processed in addition to the rest of UDP operations.
145  *
146  * The normal case plumbing is depicted by the following diagram:
147  *
148  *	+---------------+---------------+
149  *	|		|		| udp
150  *	|     udp_wq	|    udp_rq	|
151  *	|		|    UDP_RD	|
152  *	|		|		|
153  *	+---------------+---------------+
154  *		|		^
155  *		v		|
156  *	+---------------+---------------+
157  *	|		|		| /dev/ip
158  *	|     ip_wq	|     ip_rq	| conn_t
159  *	|     UDP_WR	|		|
160  *	|		|		|
161  *	+---------------+---------------+
162  *
163  * Messages arriving at udp_wq from above will end up in ip_wq before
164  * it gets processed, i.e. udp write entry points will advance udp_wq
165  * and use its q_next value as ip_wq in order to use the conn_t that
166  * is stored in its q_ptr.  Likewise, messages generated by ip to the
167  * module above udp will appear as if they are originated from udp_rq,
168  * i.e. putnext() calls to the module above udp is done using the
169  * udp_rq instead of ip_rq in order to avoid udp_rput() which does
170  * nothing more than calling putnext().
171  *
172  * The above implies the following rule of thumb:
173  *
174  *   1. udp_t is obtained from conn_t, which is created by the /dev/ip
175  *	instance and is stored in q_ptr of both ip_wq and ip_rq.  There
176  *	is no direct reference to conn_t from either udp_wq or udp_rq.
177  *
178  *   2. Write-side entry points of udp can obtain the conn_t via the
179  *	Q_TO_CONN() macro, using the queue value obtain from UDP_WR().
180  *
181  *   3. While in /dev/ip context, putnext() to the module above udp can
182  *	be done by supplying the queue value obtained from UDP_RD().
183  *
184  */
185 
186 static queue_t *UDP_WR(queue_t *);
187 static queue_t *UDP_RD(queue_t *);
188 
189 udp_stat_t udp_statistics = {
190 	{ "udp_ip_send",		KSTAT_DATA_UINT64 },
191 	{ "udp_ip_ire_send",		KSTAT_DATA_UINT64 },
192 	{ "udp_ire_null",		KSTAT_DATA_UINT64 },
193 	{ "udp_drain",			KSTAT_DATA_UINT64 },
194 	{ "udp_sock_fallback",		KSTAT_DATA_UINT64 },
195 	{ "udp_rrw_busy",		KSTAT_DATA_UINT64 },
196 	{ "udp_rrw_msgcnt",		KSTAT_DATA_UINT64 },
197 	{ "udp_out_sw_cksum",		KSTAT_DATA_UINT64 },
198 	{ "udp_out_sw_cksum_bytes",	KSTAT_DATA_UINT64 },
199 	{ "udp_out_opt",		KSTAT_DATA_UINT64 },
200 	{ "udp_out_err_notconn",	KSTAT_DATA_UINT64 },
201 	{ "udp_out_err_output",		KSTAT_DATA_UINT64 },
202 	{ "udp_out_err_tudr",		KSTAT_DATA_UINT64 },
203 	{ "udp_in_pktinfo",		KSTAT_DATA_UINT64 },
204 	{ "udp_in_recvdstaddr",		KSTAT_DATA_UINT64 },
205 	{ "udp_in_recvopts",		KSTAT_DATA_UINT64 },
206 	{ "udp_in_recvif",		KSTAT_DATA_UINT64 },
207 	{ "udp_in_recvslla",		KSTAT_DATA_UINT64 },
208 	{ "udp_in_recvucred",		KSTAT_DATA_UINT64 },
209 	{ "udp_in_recvttl",		KSTAT_DATA_UINT64 },
210 	{ "udp_in_recvhopopts",		KSTAT_DATA_UINT64 },
211 	{ "udp_in_recvhoplimit",	KSTAT_DATA_UINT64 },
212 	{ "udp_in_recvdstopts",		KSTAT_DATA_UINT64 },
213 	{ "udp_in_recvrtdstopts",	KSTAT_DATA_UINT64 },
214 	{ "udp_in_recvrthdr",		KSTAT_DATA_UINT64 },
215 	{ "udp_in_recvpktinfo",		KSTAT_DATA_UINT64 },
216 	{ "udp_in_recvtclass",		KSTAT_DATA_UINT64 },
217 #ifdef DEBUG
218 	{ "udp_data_conn",		KSTAT_DATA_UINT64 },
219 	{ "udp_data_notconn",		KSTAT_DATA_UINT64 },
220 #endif
221 };
222 
223 static kstat_t *udp_ksp;
224 struct kmem_cache *udp_cache;
225 
226 /*
227  * Bind hash list size and hash function.  It has to be a power of 2 for
228  * hashing.
229  */
230 #define	UDP_BIND_FANOUT_SIZE	512
231 #define	UDP_BIND_HASH(lport) \
232 	((ntohs((uint16_t)lport)) & (udp_bind_fanout_size - 1))
233 
234 /* UDP bind fanout hash structure. */
235 typedef struct udp_fanout_s {
236 	udp_t *uf_udp;
237 	kmutex_t uf_lock;
238 #if defined(_LP64) || defined(_I32LPx)
239 	char	uf_pad[48];
240 #else
241 	char	uf_pad[56];
242 #endif
243 } udp_fanout_t;
244 
245 uint_t udp_bind_fanout_size = UDP_BIND_FANOUT_SIZE;
246 /* udp_fanout_t *udp_bind_fanout. */
247 static udp_fanout_t *udp_bind_fanout;
248 
249 /*
250  * This controls the rate some ndd info report functions can be used
251  * by non-priviledged users.  It stores the last time such info is
252  * requested.  When those report functions are called again, this
253  * is checked with the current time and compare with the ndd param
254  * udp_ndd_get_info_interval.
255  */
256 static clock_t udp_last_ndd_get_info_time;
257 #define	NDD_TOO_QUICK_MSG \
258 	"ndd get info rate too high for non-priviledged users, try again " \
259 	"later.\n"
260 #define	NDD_OUT_OF_BUF_MSG	"<< Out of buffer >>\n"
261 
262 static void	udp_addr_req(queue_t *q, mblk_t *mp);
263 static void	udp_bind(queue_t *q, mblk_t *mp);
264 static void	udp_bind_hash_insert(udp_fanout_t *uf, udp_t *udp);
265 static void	udp_bind_hash_remove(udp_t *udp, boolean_t caller_holds_lock);
266 static int	udp_build_hdrs(queue_t *q, udp_t *udp);
267 static void	udp_capability_req(queue_t *q, mblk_t *mp);
268 static int	udp_close(queue_t *q);
269 static void	udp_connect(queue_t *q, mblk_t *mp);
270 static void	udp_disconnect(queue_t *q, mblk_t *mp);
271 static void	udp_err_ack(queue_t *q, mblk_t *mp, t_scalar_t t_error,
272 		    int sys_error);
273 static void	udp_err_ack_prim(queue_t *q, mblk_t *mp, int primitive,
274 		    t_scalar_t tlierr, int unixerr);
275 static int	udp_extra_priv_ports_get(queue_t *q, mblk_t *mp, caddr_t cp,
276 		    cred_t *cr);
277 static int	udp_extra_priv_ports_add(queue_t *q, mblk_t *mp,
278 		    char *value, caddr_t cp, cred_t *cr);
279 static int	udp_extra_priv_ports_del(queue_t *q, mblk_t *mp,
280 		    char *value, caddr_t cp, cred_t *cr);
281 static void	udp_icmp_error(queue_t *q, mblk_t *mp);
282 static void	udp_icmp_error_ipv6(queue_t *q, mblk_t *mp);
283 static void	udp_info_req(queue_t *q, mblk_t *mp);
284 static mblk_t	*udp_ip_bind_mp(udp_t *udp, t_scalar_t bind_prim,
285 		    t_scalar_t addr_length);
286 static int	udp_open(queue_t *q, dev_t *devp, int flag, int sflag,
287 		    cred_t *credp);
288 static  int	udp_unitdata_opt_process(queue_t *q, mblk_t *mp,
289 		    int *errorp, void *thisdg_attrs);
290 static boolean_t udp_opt_allow_udr_set(t_scalar_t level, t_scalar_t name);
291 static int	udp_param_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr);
292 static boolean_t udp_param_register(udpparam_t *udppa, int cnt);
293 static int	udp_param_set(queue_t *q, mblk_t *mp, char *value, caddr_t cp,
294 		    cred_t *cr);
295 static int	udp_pkt_set(uchar_t *invalp, uint_t inlen, boolean_t sticky,
296 		    uchar_t **optbufp, uint_t *optlenp);
297 static void	udp_report_item(mblk_t *mp, udp_t *udp);
298 static void	udp_rput(queue_t *q, mblk_t *mp);
299 static void	udp_rput_other(queue_t *, mblk_t *);
300 static int	udp_rinfop(queue_t *q, infod_t *dp);
301 static int	udp_rrw(queue_t *q, struiod_t *dp);
302 static	void	udp_rput_bind_ack(queue_t *q, mblk_t *mp);
303 static int	udp_status_report(queue_t *q, mblk_t *mp, caddr_t cp,
304 		    cred_t *cr);
305 static void	udp_send_data(udp_t *udp, queue_t *q, mblk_t *mp, ipha_t *ipha);
306 static void	udp_ud_err(queue_t *q, mblk_t *mp, uchar_t *destaddr,
307 		    t_scalar_t destlen, t_scalar_t err);
308 static void	udp_unbind(queue_t *q, mblk_t *mp);
309 static in_port_t udp_update_next_port(in_port_t port, boolean_t random);
310 static void	udp_wput(queue_t *q, mblk_t *mp);
311 static mblk_t	*udp_output_v4(conn_t *, mblk_t *mp, ipaddr_t v4dst,
312 		    uint16_t port, uint_t srcid, int *error);
313 static mblk_t	*udp_output_v6(conn_t *connp, mblk_t *mp, sin6_t *sin6,
314 		    t_scalar_t tudr_optlen, int *error);
315 static void	udp_wput_other(queue_t *q, mblk_t *mp);
316 static void	udp_wput_iocdata(queue_t *q, mblk_t *mp);
317 static void	udp_output(conn_t *connp, mblk_t *mp, struct sockaddr *addr,
318 		    socklen_t addrlen);
319 static size_t	udp_set_rcv_hiwat(udp_t *udp, size_t size);
320 
321 static void	udp_kstat_init(void);
322 static void	udp_kstat_fini(void);
323 static int	udp_kstat_update(kstat_t *kp, int rw);
324 static void	udp_input_wrapper(void *arg, mblk_t *mp, void *arg2);
325 static void	udp_rput_other_wrapper(void *arg, mblk_t *mp, void *arg2);
326 static void	udp_wput_other_wrapper(void *arg, mblk_t *mp, void *arg2);
327 static void	udp_resume_bind_cb(void *arg, mblk_t *mp, void *arg2);
328 
329 static void	udp_rcv_enqueue(queue_t *q, udp_t *udp, mblk_t *mp,
330 		    uint_t pkt_len);
331 static void	udp_rcv_drain(queue_t *q, udp_t *udp, boolean_t closing);
332 static void	udp_enter(conn_t *, mblk_t *, sqproc_t, uint8_t);
333 static void	udp_exit(conn_t *);
334 static void	udp_become_writer(conn_t *, mblk_t *, sqproc_t, uint8_t);
335 #ifdef DEBUG
336 static void	udp_mode_assertions(udp_t *, int);
337 #endif /* DEBUG */
338 
339 major_t UDP6_MAJ;
340 #define	UDP6 "udp6"
341 
342 #define	UDP_RECV_HIWATER	(56 * 1024)
343 #define	UDP_RECV_LOWATER	128
344 #define	UDP_XMIT_HIWATER	(56 * 1024)
345 #define	UDP_XMIT_LOWATER	1024
346 
347 static struct module_info udp_info =  {
348 	UDP_MOD_ID, UDP_MOD_NAME, 1, INFPSZ, UDP_RECV_HIWATER, UDP_RECV_LOWATER
349 };
350 
351 static struct qinit udp_rinit = {
352 	(pfi_t)udp_rput, NULL, udp_open, udp_close, NULL,
353 	&udp_info, NULL, udp_rrw, udp_rinfop, STRUIOT_STANDARD
354 };
355 
356 static struct qinit udp_winit = {
357 	(pfi_t)udp_wput, NULL, NULL, NULL, NULL,
358 	&udp_info, NULL, NULL, NULL, STRUIOT_NONE
359 };
360 
361 /* Support for just SNMP if UDP is not pushed directly over device IP */
362 struct qinit udp_snmp_rinit = {
363 	(pfi_t)putnext, NULL, udp_open, ip_snmpmod_close, NULL,
364 	&udp_info, NULL, NULL, NULL, STRUIOT_NONE
365 };
366 
367 struct qinit udp_snmp_winit = {
368 	(pfi_t)ip_snmpmod_wput, NULL, udp_open, ip_snmpmod_close, NULL,
369 	&udp_info, NULL, NULL, NULL, STRUIOT_NONE
370 };
371 
372 struct streamtab udpinfo = {
373 	&udp_rinit, &udp_winit
374 };
375 
376 static	sin_t	sin_null;	/* Zero address for quick clears */
377 static	sin6_t	sin6_null;	/* Zero address for quick clears */
378 
379 /* Hint not protected by any lock */
380 static in_port_t	udp_g_next_port_to_try;
381 
382 /*
383  * Extra privileged ports. In host byte order.
384  */
385 #define	UDP_NUM_EPRIV_PORTS	64
386 static int	udp_g_num_epriv_ports = UDP_NUM_EPRIV_PORTS;
387 static in_port_t udp_g_epriv_ports[UDP_NUM_EPRIV_PORTS] = { 2049, 4045 };
388 
389 /* Only modified during _init and _fini thus no locking is needed. */
390 static IDP	udp_g_nd;	/* Points to table of UDP ND variables. */
391 
392 /* MIB-2 stuff for SNMP */
393 static mib2_udp_t	udp_mib;	/* SNMP fixed size info */
394 static kstat_t		*udp_mibkp;	/* kstat exporting udp_mib data */
395 
396 #define	UDP_MAXPACKET_IPV4 (IP_MAXPACKET - UDPH_SIZE - IP_SIMPLE_HDR_LENGTH)
397 
398 /* Default structure copied into T_INFO_ACK messages */
399 static struct T_info_ack udp_g_t_info_ack_ipv4 = {
400 	T_INFO_ACK,
401 	UDP_MAXPACKET_IPV4,	/* TSDU_size. Excl. headers */
402 	T_INVALID,	/* ETSU_size.  udp does not support expedited data. */
403 	T_INVALID,	/* CDATA_size. udp does not support connect data. */
404 	T_INVALID,	/* DDATA_size. udp does not support disconnect data. */
405 	sizeof (sin_t),	/* ADDR_size. */
406 	0,		/* OPT_size - not initialized here */
407 	UDP_MAXPACKET_IPV4,	/* TIDU_size.  Excl. headers */
408 	T_CLTS,		/* SERV_type.  udp supports connection-less. */
409 	TS_UNBND,	/* CURRENT_state.  This is set from udp_state. */
410 	(XPG4_1|SENDZERO) /* PROVIDER_flag */
411 };
412 
413 #define	UDP_MAXPACKET_IPV6 (IP_MAXPACKET - UDPH_SIZE - IPV6_HDR_LEN)
414 
415 static	struct T_info_ack udp_g_t_info_ack_ipv6 = {
416 	T_INFO_ACK,
417 	UDP_MAXPACKET_IPV6,	/* TSDU_size.  Excl. headers */
418 	T_INVALID,	/* ETSU_size.  udp does not support expedited data. */
419 	T_INVALID,	/* CDATA_size. udp does not support connect data. */
420 	T_INVALID,	/* DDATA_size. udp does not support disconnect data. */
421 	sizeof (sin6_t), /* ADDR_size. */
422 	0,		/* OPT_size - not initialized here */
423 	UDP_MAXPACKET_IPV6,	/* TIDU_size. Excl. headers */
424 	T_CLTS,		/* SERV_type.  udp supports connection-less. */
425 	TS_UNBND,	/* CURRENT_state.  This is set from udp_state. */
426 	(XPG4_1|SENDZERO) /* PROVIDER_flag */
427 };
428 
429 /* largest UDP port number */
430 #define	UDP_MAX_PORT	65535
431 
432 /*
433  * Table of ND variables supported by udp.  These are loaded into udp_g_nd
434  * in udp_open.
435  * All of these are alterable, within the min/max values given, at run time.
436  */
437 /* BEGIN CSTYLED */
438 udpparam_t udp_param_arr[] = {
439  /*min		max		value		name */
440  { 0L,		256,		32,		"udp_wroff_extra" },
441  { 1L,		255,		255,		"udp_ipv4_ttl" },
442  { 0,		IPV6_MAX_HOPS,	IPV6_DEFAULT_HOPS, "udp_ipv6_hoplimit"},
443  { 1024,	(32 * 1024),	1024,		"udp_smallest_nonpriv_port" },
444  { 0,		1,		1,		"udp_do_checksum" },
445  { 1024,	UDP_MAX_PORT,	(32 * 1024),	"udp_smallest_anon_port" },
446  { 1024,	UDP_MAX_PORT,	UDP_MAX_PORT,	"udp_largest_anon_port" },
447  { UDP_XMIT_LOWATER, (1<<30), UDP_XMIT_HIWATER,	"udp_xmit_hiwat"},
448  { 0,		     (1<<30), UDP_XMIT_LOWATER, "udp_xmit_lowat"},
449  { UDP_RECV_LOWATER, (1<<30), UDP_RECV_HIWATER,	"udp_recv_hiwat"},
450  { 65536,	(1<<30),	2*1024*1024,	"udp_max_buf"},
451  { 100,		60000,		1000,		"udp_ndd_get_info_interval"},
452 };
453 /* END CSTYLED */
454 
455 /*
456  * The smallest anonymous port in the priviledged port range which UDP
457  * looks for free port.  Use in the option UDP_ANONPRIVBIND.
458  */
459 static in_port_t udp_min_anonpriv_port = 512;
460 
461 /* If set to 0, pick ephemeral port sequentially; otherwise randomly. */
462 uint32_t udp_random_anon_port = 1;
463 
464 /*
465  * Hook functions to enable cluster networking.
466  * On non-clustered systems these vectors must always be NULL
467  */
468 
469 void (*cl_inet_bind)(uchar_t protocol, sa_family_t addr_family,
470     uint8_t *laddrp, in_port_t lport) = NULL;
471 void (*cl_inet_unbind)(uint8_t protocol, sa_family_t addr_family,
472     uint8_t *laddrp, in_port_t lport) = NULL;
473 
474 typedef union T_primitives *t_primp_t;
475 
476 #define	UDP_ENQUEUE_MP(udp, mp, proc, tag) {			\
477 	ASSERT((mp)->b_prev == NULL && (mp)->b_queue == NULL);	\
478 	ASSERT(MUTEX_HELD(&(udp)->udp_connp->conn_lock));	\
479 	(mp)->b_queue = (queue_t *)((uintptr_t)tag);		\
480 	(mp)->b_prev = (mblk_t *)proc;				\
481 	if ((udp)->udp_mphead == NULL)				\
482 		(udp)->udp_mphead = (mp);			\
483 	else							\
484 		(udp)->udp_mptail->b_next = (mp);		\
485 	(udp)->udp_mptail = (mp);				\
486 	(udp)->udp_mpcount++;					\
487 }
488 
489 #define	UDP_READERS_INCREF(udp) {				\
490 	ASSERT(MUTEX_HELD(&(udp)->udp_connp->conn_lock));	\
491 	(udp)->udp_reader_count++;				\
492 }
493 
494 #define	UDP_READERS_DECREF(udp) {				\
495 	ASSERT(MUTEX_HELD(&(udp)->udp_connp->conn_lock));	\
496 	(udp)->udp_reader_count--;				\
497 	if ((udp)->udp_reader_count == 0)			\
498 		cv_broadcast(&(udp)->udp_connp->conn_cv);	\
499 }
500 
501 #define	UDP_SQUEUE_DECREF(udp) {				\
502 	ASSERT(MUTEX_HELD(&(udp)->udp_connp->conn_lock));	\
503 	(udp)->udp_squeue_count--;				\
504 	if ((udp)->udp_squeue_count == 0)			\
505 		cv_broadcast(&(udp)->udp_connp->conn_cv);	\
506 }
507 
508 /*
509  * Notes on UDP endpoint synchronization:
510  *
511  * UDP needs exclusive operation on a per endpoint basis, when executing
512  * functions that modify the endpoint state.  udp_rput_other() deals with
513  * packets with IP options, and processing these packets end up having
514  * to update the endpoint's option related state.  udp_wput_other() deals
515  * with control operations from the top, e.g. connect() that needs to
516  * update the endpoint state.  These could be synchronized using locks,
517  * but the current version uses squeues for this purpose.  squeues may
518  * give performance improvement for certain cases such as connected UDP
519  * sockets; thus the framework allows for using squeues.
520  *
521  * The perimeter routines are described as follows:
522  *
523  * udp_enter():
524  *	Enter the UDP endpoint perimeter.
525  *
526  * udp_become_writer():
527  *	Become exclusive on the UDP endpoint.  Specifies a function
528  *	that will be called exclusively either immediately or later
529  *	when the perimeter is available exclusively.
530  *
531  * udp_exit():
532  *	Exit the UDP perimeter.
533  *
534  * Entering UDP from the top or from the bottom must be done using
535  * udp_enter().  No lock must be held while attempting to enter the UDP
536  * perimeter.  When finished, udp_exit() must be called to get out of
537  * the perimeter.
538  *
539  * UDP operates in either MT_HOT mode or in SQUEUE mode.  In MT_HOT mode,
540  * multiple threads may enter a UDP endpoint concurrently.  This is used
541  * for sending and/or receiving normal data.  Control operations and other
542  * special cases call udp_become_writer() to become exclusive on a per
543  * endpoint basis and this results in transitioning to SQUEUE mode.  squeue
544  * by definition serializes access to the conn_t.  When there are no more
545  * pending messages on the squeue for the UDP connection, the endpoint
546  * reverts to MT_HOT mode.  During the interregnum when not all MT threads
547  * of an endpoint have finished, messages are queued in the UDP endpoint
548  * and the UDP is in UDP_MT_QUEUED mode or UDP_QUEUED_SQUEUE mode.
549  *
550  * These modes have the following analogs:
551  *
552  *	UDP_MT_HOT/udp_reader_count==0		none
553  *	UDP_MT_HOT/udp_reader_count>0		RW_READ_LOCK
554  *	UDP_MT_QUEUED				RW_WRITE_WANTED
555  *	UDP_SQUEUE or UDP_QUEUED_SQUEUE		RW_WRITE_LOCKED
556  *
557  * Stable modes:	UDP_MT_HOT, UDP_SQUEUE
558  * Transient modes:	UDP_MT_QUEUED, UDP_QUEUED_SQUEUE
559  *
560  * While in stable modes, UDP keeps track of the number of threads
561  * operating on the endpoint.  The udp_reader_count variable represents
562  * the number of threads entering the endpoint as readers while it is
563  * in UDP_MT_HOT mode.  Transitioning to UDP_SQUEUE happens when there
564  * is only a single reader, i.e. when this counter drops to 1.  Likewise,
565  * udp_squeue_count represents the number of threads operating on the
566  * endpoint's squeue while it is in UDP_SQUEUE mode.  The mode transition
567  * to UDP_MT_HOT happens after the last thread exits the endpoint, i.e.
568  * when this counter drops to 0.
569  *
570  * The default mode is set to UDP_MT_HOT and UDP alternates between
571  * UDP_MT_HOT and UDP_SQUEUE as shown in the state transition below.
572  *
573  * Mode transition:
574  * ----------------------------------------------------------------
575  * old mode		Event				New mode
576  * ----------------------------------------------------------------
577  * UDP_MT_HOT		Call to udp_become_writer()	UDP_SQUEUE
578  *			and udp_reader_count == 1
579  *
580  * UDP_MT_HOT		Call to udp_become_writer()	UDP_MT_QUEUED
581  *			and udp_reader_count > 1
582  *
583  * UDP_MT_QUEUED	udp_reader_count drops to zero	UDP_QUEUED_SQUEUE
584  *
585  * UDP_QUEUED_SQUEUE	All messages enqueued on the	UDP_SQUEUE
586  *			internal UDP queue successfully
587  *			moved to squeue AND udp_squeue_count != 0
588  *
589  * UDP_QUEUED_SQUEUE	All messages enqueued on the	UDP_MT_HOT
590  *			internal UDP queue successfully
591  *			moved to squeue AND udp_squeue_count
592  *			drops to zero
593  *
594  * UDP_SQUEUE		udp_squeue_count drops to zero	UDP_MT_HOT
595  * ----------------------------------------------------------------
596  */
597 
598 static queue_t *
599 UDP_WR(queue_t *q)
600 {
601 	ASSERT(q->q_ptr == NULL && _OTHERQ(q)->q_ptr == NULL);
602 	ASSERT(WR(q)->q_next != NULL && WR(q)->q_next->q_ptr != NULL);
603 	ASSERT(IPCL_IS_UDP(Q_TO_CONN(WR(q)->q_next)));
604 
605 	return (_WR(q)->q_next);
606 }
607 
608 static queue_t *
609 UDP_RD(queue_t *q)
610 {
611 	ASSERT(q->q_ptr != NULL && _OTHERQ(q)->q_ptr != NULL);
612 	ASSERT(IPCL_IS_UDP(Q_TO_CONN(q)));
613 	ASSERT(RD(q)->q_next != NULL && RD(q)->q_next->q_ptr == NULL);
614 
615 	return (_RD(q)->q_next);
616 }
617 
618 #ifdef DEBUG
619 #define	UDP_MODE_ASSERTIONS(udp, caller) udp_mode_assertions(udp, caller)
620 #else
621 #define	UDP_MODE_ASSERTIONS(udp, caller)
622 #endif
623 
624 /* Invariants */
625 #ifdef DEBUG
626 
627 uint32_t udp_count[4];
628 
629 /* Context of udp_mode_assertions */
630 #define	UDP_ENTER		1
631 #define	UDP_BECOME_WRITER	2
632 #define	UDP_EXIT		3
633 
634 static void
635 udp_mode_assertions(udp_t *udp, int caller)
636 {
637 	ASSERT(MUTEX_HELD(&udp->udp_connp->conn_lock));
638 
639 	switch (udp->udp_mode) {
640 	case UDP_MT_HOT:
641 		/*
642 		 * Messages have not yet been enqueued on the internal queue,
643 		 * otherwise we would have switched to UDP_MT_QUEUED. Likewise
644 		 * by definition, there can't be any messages enqueued on the
645 		 * squeue. The UDP could be quiescent, so udp_reader_count
646 		 * could be zero at entry.
647 		 */
648 		ASSERT(udp->udp_mphead == NULL && udp->udp_mpcount == 0 &&
649 		    udp->udp_squeue_count == 0);
650 		ASSERT(caller == UDP_ENTER || udp->udp_reader_count != 0);
651 		udp_count[0]++;
652 		break;
653 
654 	case UDP_MT_QUEUED:
655 		/*
656 		 * The last MT thread to exit the udp perimeter empties the
657 		 * internal queue and then switches the UDP to
658 		 * UDP_QUEUED_SQUEUE mode. Since we are still in UDP_MT_QUEUED
659 		 * mode, it means there must be at least 1 MT thread still in
660 		 * the perimeter and at least 1 message on the internal queue.
661 		 */
662 		ASSERT(udp->udp_reader_count >= 1 && udp->udp_mphead != NULL &&
663 		    udp->udp_mpcount != 0 && udp->udp_squeue_count == 0);
664 		udp_count[1]++;
665 		break;
666 
667 	case UDP_QUEUED_SQUEUE:
668 		/*
669 		 * The switch has happened from MT to SQUEUE. So there can't
670 		 * any MT threads. Messages could still pile up on the internal
671 		 * queue until the transition is complete and we move to
672 		 * UDP_SQUEUE mode. We can't assert on nonzero udp_squeue_count
673 		 * since the squeue could drain any time.
674 		 */
675 		ASSERT(udp->udp_reader_count == 0);
676 		udp_count[2]++;
677 		break;
678 
679 	case UDP_SQUEUE:
680 		/*
681 		 * The transition is complete. Thre can't be any messages on
682 		 * the internal queue. The udp could be quiescent or the squeue
683 		 * could drain any time, so we can't assert on nonzero
684 		 * udp_squeue_count during entry. Nor can we assert that
685 		 * udp_reader_count is zero, since, a reader thread could have
686 		 * directly become writer in line by calling udp_become_writer
687 		 * without going through the queued states.
688 		 */
689 		ASSERT(udp->udp_mphead == NULL && udp->udp_mpcount == 0);
690 		ASSERT(caller == UDP_ENTER || udp->udp_squeue_count != 0);
691 		udp_count[3]++;
692 		break;
693 	}
694 }
695 #endif
696 
697 #define	_UDP_ENTER(connp, mp, proc, tag) {				\
698 	udp_t *_udp = (connp)->conn_udp;				\
699 									\
700 	mutex_enter(&(connp)->conn_lock);				\
701 	if ((connp)->conn_state_flags & CONN_CLOSING) {			\
702 		mutex_exit(&(connp)->conn_lock);			\
703 		freemsg(mp);						\
704 	} else {							\
705 		UDP_MODE_ASSERTIONS(_udp, UDP_ENTER);			\
706 									\
707 		switch (_udp->udp_mode) {				\
708 		case UDP_MT_HOT:					\
709 			/* We can execute as reader right away. */	\
710 			UDP_READERS_INCREF(_udp);			\
711 			mutex_exit(&(connp)->conn_lock);		\
712 			(*(proc))(connp, mp, (connp)->conn_sqp);	\
713 			break;						\
714 									\
715 		case UDP_SQUEUE:					\
716 			/*						\
717 			 * We are in squeue mode, send the		\
718 			 * packet to the squeue				\
719 			 */						\
720 			_udp->udp_squeue_count++;			\
721 			CONN_INC_REF_LOCKED(connp);			\
722 			mutex_exit(&(connp)->conn_lock);		\
723 			squeue_enter((connp)->conn_sqp, mp, proc,	\
724 			    connp, tag);				\
725 			break;						\
726 									\
727 		case UDP_MT_QUEUED:					\
728 		case UDP_QUEUED_SQUEUE:					\
729 			/*						\
730 			 * Some messages may have been enqueued		\
731 			 * ahead of us.  Enqueue the new message	\
732 			 * at the tail of the internal queue to		\
733 			 * preserve message ordering.			\
734 			 */						\
735 			UDP_ENQUEUE_MP(_udp, mp, proc, tag);		\
736 			mutex_exit(&(connp)->conn_lock);		\
737 			break;						\
738 		}							\
739 	}								\
740 }
741 
742 static void
743 udp_enter(conn_t *connp, mblk_t *mp, sqproc_t proc, uint8_t tag)
744 {
745 	_UDP_ENTER(connp, mp, proc, tag);
746 }
747 
748 static void
749 udp_become_writer(conn_t *connp, mblk_t *mp, sqproc_t proc, uint8_t tag)
750 {
751 	udp_t	*udp;
752 
753 	udp = connp->conn_udp;
754 
755 	mutex_enter(&connp->conn_lock);
756 
757 	UDP_MODE_ASSERTIONS(udp, UDP_BECOME_WRITER);
758 
759 	switch (udp->udp_mode) {
760 	case UDP_MT_HOT:
761 		if (udp->udp_reader_count == 1) {
762 			/*
763 			 * We are the only MT thread. Switch to squeue mode
764 			 * immediately.
765 			 */
766 			udp->udp_mode = UDP_SQUEUE;
767 			udp->udp_squeue_count = 1;
768 			CONN_INC_REF_LOCKED(connp);
769 			mutex_exit(&connp->conn_lock);
770 			squeue_enter(connp->conn_sqp, mp, proc, connp, tag);
771 			return;
772 		}
773 		/* FALLTHRU */
774 
775 	case UDP_MT_QUEUED:
776 		/* Enqueue the packet internally in UDP */
777 		udp->udp_mode = UDP_MT_QUEUED;
778 		UDP_ENQUEUE_MP(udp, mp, proc, tag);
779 		mutex_exit(&connp->conn_lock);
780 		return;
781 
782 	case UDP_SQUEUE:
783 	case UDP_QUEUED_SQUEUE:
784 		/*
785 		 * We are already exclusive. i.e. we are already
786 		 * writer. Simply call the desired function.
787 		 */
788 		udp->udp_squeue_count++;
789 		mutex_exit(&connp->conn_lock);
790 		(*proc)(connp, mp, connp->conn_sqp);
791 		return;
792 	}
793 }
794 
795 /*
796  * Transition from MT mode to SQUEUE mode, when the last MT thread
797  * is exiting the UDP perimeter. Move all messages from the internal
798  * udp queue to the squeue. A better way would be to move all the
799  * messages in one shot, this needs more support from the squeue framework
800  */
801 static void
802 udp_switch_to_squeue(udp_t *udp)
803 {
804 	mblk_t *mp;
805 	mblk_t	*mp_next;
806 	sqproc_t proc;
807 	uint8_t	tag;
808 	conn_t	*connp = udp->udp_connp;
809 
810 	ASSERT(MUTEX_HELD(&connp->conn_lock));
811 	ASSERT(udp->udp_mode == UDP_MT_QUEUED);
812 	while (udp->udp_mphead != NULL) {
813 		mp = udp->udp_mphead;
814 		udp->udp_mphead = NULL;
815 		udp->udp_mptail = NULL;
816 		udp->udp_mpcount = 0;
817 		udp->udp_mode = UDP_QUEUED_SQUEUE;
818 		mutex_exit(&connp->conn_lock);
819 		/*
820 		 * It is best not to hold any locks across the calls
821 		 * to squeue functions. Since we drop the lock we
822 		 * need to go back and check the udp_mphead once again
823 		 * after the squeue_fill and hence the while loop at
824 		 * the top of this function
825 		 */
826 		for (; mp != NULL; mp = mp_next) {
827 			mp_next = mp->b_next;
828 			proc = (sqproc_t)mp->b_prev;
829 			tag = (uint8_t)((uintptr_t)mp->b_queue);
830 			mp->b_next = NULL;
831 			mp->b_prev = NULL;
832 			mp->b_queue = NULL;
833 			CONN_INC_REF(connp);
834 			udp->udp_squeue_count++;
835 			squeue_fill(connp->conn_sqp, mp, proc, connp,
836 			    tag);
837 		}
838 		mutex_enter(&connp->conn_lock);
839 	}
840 	/*
841 	 * udp_squeue_count of zero implies that the squeue has drained
842 	 * even before we arrived here (i.e. after the squeue_fill above)
843 	 */
844 	udp->udp_mode = (udp->udp_squeue_count != 0) ?
845 	    UDP_SQUEUE : UDP_MT_HOT;
846 }
847 
848 #define	_UDP_EXIT(connp) {						\
849 	udp_t *_udp = (connp)->conn_udp;				\
850 									\
851 	mutex_enter(&(connp)->conn_lock);				\
852 	UDP_MODE_ASSERTIONS(_udp, UDP_EXIT);				\
853 									\
854 	switch (_udp->udp_mode) {					\
855 	case UDP_MT_HOT:						\
856 		UDP_READERS_DECREF(_udp);				\
857 		mutex_exit(&(connp)->conn_lock);			\
858 		break;							\
859 									\
860 	case UDP_SQUEUE:						\
861 		UDP_SQUEUE_DECREF(_udp);				\
862 		if (_udp->udp_squeue_count == 0)			\
863 		    _udp->udp_mode = UDP_MT_HOT;			\
864 		mutex_exit(&(connp)->conn_lock);			\
865 		break;							\
866 									\
867 	case UDP_MT_QUEUED:						\
868 		/*							\
869 		 * If this is the last MT thread, we need to		\
870 		 * switch to squeue mode				\
871 		 */							\
872 		UDP_READERS_DECREF(_udp);				\
873 		if (_udp->udp_reader_count == 0)			\
874 			udp_switch_to_squeue(_udp);			\
875 		mutex_exit(&(connp)->conn_lock);			\
876 		break;							\
877 									\
878 	case UDP_QUEUED_SQUEUE:						\
879 		UDP_SQUEUE_DECREF(_udp);				\
880 		/*							\
881 		 * Even if the udp_squeue_count drops to zero, we	\
882 		 * don't want to change udp_mode to UDP_MT_HOT here.	\
883 		 * The thread in udp_switch_to_squeue will take care	\
884 		 * of the transition to UDP_MT_HOT, after emptying	\
885 		 * any more new messages that have been enqueued in	\
886 		 * udp_mphead.						\
887 		 */							\
888 		mutex_exit(&(connp)->conn_lock);			\
889 		break;							\
890 	}								\
891 }
892 
893 static void
894 udp_exit(conn_t *connp)
895 {
896 	_UDP_EXIT(connp);
897 }
898 
899 /*
900  * Return the next anonymous port in the priviledged port range for
901  * bind checking.
902  */
903 static in_port_t
904 udp_get_next_priv_port(void)
905 {
906 	static in_port_t next_priv_port = IPPORT_RESERVED - 1;
907 
908 	if (next_priv_port < udp_min_anonpriv_port) {
909 		next_priv_port = IPPORT_RESERVED - 1;
910 	}
911 	return (next_priv_port--);
912 }
913 
914 /* UDP bind hash report triggered via the Named Dispatch mechanism. */
915 /* ARGSUSED */
916 static int
917 udp_bind_hash_report(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr)
918 {
919 	udp_fanout_t	*udpf;
920 	int		i;
921 	zoneid_t	zoneid;
922 	conn_t		*connp;
923 	udp_t		*udp;
924 
925 	connp = Q_TO_CONN(q);
926 	udp = connp->conn_udp;
927 
928 	/* Refer to comments in udp_status_report(). */
929 	if (cr == NULL || secpolicy_net_config(cr, B_TRUE) != 0) {
930 		if (ddi_get_lbolt() - udp_last_ndd_get_info_time <
931 		    drv_usectohz(udp_ndd_get_info_interval * 1000)) {
932 			(void) mi_mpprintf(mp, NDD_TOO_QUICK_MSG);
933 			return (0);
934 		}
935 	}
936 	if ((mp->b_cont = allocb(ND_MAX_BUF_LEN, BPRI_HI)) == NULL) {
937 		/* The following may work even if we cannot get a large buf. */
938 		(void) mi_mpprintf(mp, NDD_OUT_OF_BUF_MSG);
939 		return (0);
940 	}
941 
942 	(void) mi_mpprintf(mp,
943 	    "UDP     " MI_COL_HDRPAD_STR
944 	/*   12345678[89ABCDEF] */
945 	    " zone lport src addr        dest addr       port  state");
946 	/*    1234 12345 xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx 12345 UNBOUND */
947 
948 	zoneid = connp->conn_zoneid;
949 
950 	for (i = 0; i < udp_bind_fanout_size; i++) {
951 		udpf = &udp_bind_fanout[i];
952 		mutex_enter(&udpf->uf_lock);
953 
954 		/* Print the hash index. */
955 		udp = udpf->uf_udp;
956 		if (zoneid != GLOBAL_ZONEID) {
957 			/* skip to first entry in this zone; might be none */
958 			while (udp != NULL &&
959 			    udp->udp_connp->conn_zoneid != zoneid)
960 				udp = udp->udp_bind_hash;
961 		}
962 		if (udp != NULL) {
963 			uint_t print_len, buf_len;
964 
965 			buf_len = mp->b_cont->b_datap->db_lim -
966 			    mp->b_cont->b_wptr;
967 			print_len = snprintf((char *)mp->b_cont->b_wptr,
968 			    buf_len, "%d\n", i);
969 			if (print_len < buf_len) {
970 				mp->b_cont->b_wptr += print_len;
971 			} else {
972 				mp->b_cont->b_wptr += buf_len;
973 			}
974 			for (; udp != NULL; udp = udp->udp_bind_hash) {
975 				if (zoneid == GLOBAL_ZONEID ||
976 				    zoneid == udp->udp_connp->conn_zoneid)
977 					udp_report_item(mp->b_cont, udp);
978 			}
979 		}
980 		mutex_exit(&udpf->uf_lock);
981 	}
982 	udp_last_ndd_get_info_time = ddi_get_lbolt();
983 	return (0);
984 }
985 
986 /*
987  * Hash list removal routine for udp_t structures.
988  */
989 static void
990 udp_bind_hash_remove(udp_t *udp, boolean_t caller_holds_lock)
991 {
992 	udp_t	*udpnext;
993 	kmutex_t *lockp;
994 
995 	if (udp->udp_ptpbhn == NULL)
996 		return;
997 
998 	/*
999 	 * Extract the lock pointer in case there are concurrent
1000 	 * hash_remove's for this instance.
1001 	 */
1002 	ASSERT(udp->udp_port != 0);
1003 	if (!caller_holds_lock) {
1004 		lockp = &udp_bind_fanout[UDP_BIND_HASH(udp->udp_port)].uf_lock;
1005 		ASSERT(lockp != NULL);
1006 		mutex_enter(lockp);
1007 	}
1008 	if (udp->udp_ptpbhn != NULL) {
1009 		udpnext = udp->udp_bind_hash;
1010 		if (udpnext != NULL) {
1011 			udpnext->udp_ptpbhn = udp->udp_ptpbhn;
1012 			udp->udp_bind_hash = NULL;
1013 		}
1014 		*udp->udp_ptpbhn = udpnext;
1015 		udp->udp_ptpbhn = NULL;
1016 	}
1017 	if (!caller_holds_lock) {
1018 		mutex_exit(lockp);
1019 	}
1020 }
1021 
1022 static void
1023 udp_bind_hash_insert(udp_fanout_t *uf, udp_t *udp)
1024 {
1025 	udp_t	**udpp;
1026 	udp_t	*udpnext;
1027 
1028 	ASSERT(MUTEX_HELD(&uf->uf_lock));
1029 	if (udp->udp_ptpbhn != NULL) {
1030 		udp_bind_hash_remove(udp, B_TRUE);
1031 	}
1032 	udpp = &uf->uf_udp;
1033 	udpnext = udpp[0];
1034 	if (udpnext != NULL) {
1035 		/*
1036 		 * If the new udp bound to the INADDR_ANY address
1037 		 * and the first one in the list is not bound to
1038 		 * INADDR_ANY we skip all entries until we find the
1039 		 * first one bound to INADDR_ANY.
1040 		 * This makes sure that applications binding to a
1041 		 * specific address get preference over those binding to
1042 		 * INADDR_ANY.
1043 		 */
1044 		if (V6_OR_V4_INADDR_ANY(udp->udp_bound_v6src) &&
1045 		    !V6_OR_V4_INADDR_ANY(udpnext->udp_bound_v6src)) {
1046 			while ((udpnext = udpp[0]) != NULL &&
1047 			    !V6_OR_V4_INADDR_ANY(
1048 			    udpnext->udp_bound_v6src)) {
1049 				udpp = &(udpnext->udp_bind_hash);
1050 			}
1051 			if (udpnext != NULL)
1052 				udpnext->udp_ptpbhn = &udp->udp_bind_hash;
1053 		} else {
1054 			udpnext->udp_ptpbhn = &udp->udp_bind_hash;
1055 		}
1056 	}
1057 	udp->udp_bind_hash = udpnext;
1058 	udp->udp_ptpbhn = udpp;
1059 	udpp[0] = udp;
1060 }
1061 
1062 /*
1063  * This routine is called to handle each O_T_BIND_REQ/T_BIND_REQ message
1064  * passed to udp_wput.
1065  * It associates a port number and local address with the stream.
1066  * The O_T_BIND_REQ/T_BIND_REQ is passed downstream to ip with the UDP
1067  * protocol type (IPPROTO_UDP) placed in the message following the address.
1068  * A T_BIND_ACK message is passed upstream when ip acknowledges the request.
1069  * (Called as writer.)
1070  *
1071  * Note that UDP over IPv4 and IPv6 sockets can use the same port number
1072  * without setting SO_REUSEADDR. This is needed so that they
1073  * can be viewed as two independent transport protocols.
1074  * However, anonymouns ports are allocated from the same range to avoid
1075  * duplicating the udp_g_next_port_to_try.
1076  */
1077 static void
1078 udp_bind(queue_t *q, mblk_t *mp)
1079 {
1080 	sin_t		*sin;
1081 	sin6_t		*sin6;
1082 	mblk_t		*mp1;
1083 	in_port_t	port;		/* Host byte order */
1084 	in_port_t	requested_port;	/* Host byte order */
1085 	struct T_bind_req *tbr;
1086 	int		count;
1087 	in6_addr_t	v6src;
1088 	boolean_t	bind_to_req_port_only;
1089 	int		loopmax;
1090 	udp_fanout_t	*udpf;
1091 	in_port_t	lport;		/* Network byte order */
1092 	zoneid_t	zoneid;
1093 	conn_t		*connp;
1094 	udp_t		*udp;
1095 
1096 	connp = Q_TO_CONN(q);
1097 	udp = connp->conn_udp;
1098 	if ((mp->b_wptr - mp->b_rptr) < sizeof (*tbr)) {
1099 		(void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
1100 		    "udp_bind: bad req, len %u",
1101 		    (uint_t)(mp->b_wptr - mp->b_rptr));
1102 		udp_err_ack(q, mp, TPROTO, 0);
1103 		return;
1104 	}
1105 
1106 	if (udp->udp_state != TS_UNBND) {
1107 		(void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
1108 		    "udp_bind: bad state, %u", udp->udp_state);
1109 		udp_err_ack(q, mp, TOUTSTATE, 0);
1110 		return;
1111 	}
1112 	/*
1113 	 * Reallocate the message to make sure we have enough room for an
1114 	 * address and the protocol type.
1115 	 */
1116 	mp1 = reallocb(mp, sizeof (struct T_bind_ack) + sizeof (sin6_t) + 1, 1);
1117 	if (!mp1) {
1118 		udp_err_ack(q, mp, TSYSERR, ENOMEM);
1119 		return;
1120 	}
1121 
1122 	mp = mp1;
1123 	tbr = (struct T_bind_req *)mp->b_rptr;
1124 	switch (tbr->ADDR_length) {
1125 	case 0:			/* Request for a generic port */
1126 		tbr->ADDR_offset = sizeof (struct T_bind_req);
1127 		if (udp->udp_family == AF_INET) {
1128 			tbr->ADDR_length = sizeof (sin_t);
1129 			sin = (sin_t *)&tbr[1];
1130 			*sin = sin_null;
1131 			sin->sin_family = AF_INET;
1132 			mp->b_wptr = (uchar_t *)&sin[1];
1133 		} else {
1134 			ASSERT(udp->udp_family == AF_INET6);
1135 			tbr->ADDR_length = sizeof (sin6_t);
1136 			sin6 = (sin6_t *)&tbr[1];
1137 			*sin6 = sin6_null;
1138 			sin6->sin6_family = AF_INET6;
1139 			mp->b_wptr = (uchar_t *)&sin6[1];
1140 		}
1141 		port = 0;
1142 		break;
1143 
1144 	case sizeof (sin_t):	/* Complete IPv4 address */
1145 		sin = (sin_t *)mi_offset_param(mp, tbr->ADDR_offset,
1146 		    sizeof (sin_t));
1147 		if (sin == NULL || !OK_32PTR((char *)sin)) {
1148 			udp_err_ack(q, mp, TSYSERR, EINVAL);
1149 			return;
1150 		}
1151 		if (udp->udp_family != AF_INET ||
1152 		    sin->sin_family != AF_INET) {
1153 			udp_err_ack(q, mp, TSYSERR, EAFNOSUPPORT);
1154 			return;
1155 		}
1156 		port = ntohs(sin->sin_port);
1157 		break;
1158 
1159 	case sizeof (sin6_t):	/* complete IPv6 address */
1160 		sin6 = (sin6_t *)mi_offset_param(mp, tbr->ADDR_offset,
1161 		    sizeof (sin6_t));
1162 		if (sin6 == NULL || !OK_32PTR((char *)sin6)) {
1163 			udp_err_ack(q, mp, TSYSERR, EINVAL);
1164 			return;
1165 		}
1166 		if (udp->udp_family != AF_INET6 ||
1167 		    sin6->sin6_family != AF_INET6) {
1168 			udp_err_ack(q, mp, TSYSERR, EAFNOSUPPORT);
1169 			return;
1170 		}
1171 		port = ntohs(sin6->sin6_port);
1172 		break;
1173 
1174 	default:		/* Invalid request */
1175 		(void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
1176 		    "udp_bind: bad ADDR_length length %u", tbr->ADDR_length);
1177 		udp_err_ack(q, mp, TBADADDR, 0);
1178 		return;
1179 	}
1180 
1181 	requested_port = port;
1182 
1183 	if (requested_port == 0 || tbr->PRIM_type == O_T_BIND_REQ)
1184 		bind_to_req_port_only = B_FALSE;
1185 	else			/* T_BIND_REQ and requested_port != 0 */
1186 		bind_to_req_port_only = B_TRUE;
1187 
1188 	if (requested_port == 0) {
1189 		/*
1190 		 * If the application passed in zero for the port number, it
1191 		 * doesn't care which port number we bind to. Get one in the
1192 		 * valid range.
1193 		 */
1194 		if (udp->udp_anon_priv_bind) {
1195 			port = udp_get_next_priv_port();
1196 		} else {
1197 			port = udp_update_next_port(udp_g_next_port_to_try,
1198 			    B_TRUE);
1199 		}
1200 	} else {
1201 		/*
1202 		 * If the port is in the well-known privileged range,
1203 		 * make sure the caller was privileged.
1204 		 */
1205 		int i;
1206 		boolean_t priv = B_FALSE;
1207 
1208 		if (port < udp_smallest_nonpriv_port) {
1209 			priv = B_TRUE;
1210 		} else {
1211 			for (i = 0; i < udp_g_num_epriv_ports; i++) {
1212 				if (port == udp_g_epriv_ports[i]) {
1213 					priv = B_TRUE;
1214 					break;
1215 				}
1216 			}
1217 		}
1218 
1219 		if (priv) {
1220 			cred_t *cr = DB_CREDDEF(mp, connp->conn_cred);
1221 
1222 			if (secpolicy_net_privaddr(cr, port) != 0) {
1223 				udp_err_ack(q, mp, TACCES, 0);
1224 				return;
1225 			}
1226 		}
1227 	}
1228 
1229 	/*
1230 	 * Copy the source address into our udp structure. This address
1231 	 * may still be zero; if so, IP will fill in the correct address
1232 	 * each time an outbound packet is passed to it.
1233 	 */
1234 	if (udp->udp_family == AF_INET) {
1235 		ASSERT(sin != NULL);
1236 		ASSERT(udp->udp_ipversion == IPV4_VERSION);
1237 		udp->udp_max_hdr_len = IP_SIMPLE_HDR_LENGTH + UDPH_SIZE +
1238 		    udp->udp_ip_snd_options_len;
1239 		IN6_IPADDR_TO_V4MAPPED(sin->sin_addr.s_addr, &v6src);
1240 	} else {
1241 		ASSERT(sin6 != NULL);
1242 		v6src = sin6->sin6_addr;
1243 		if (IN6_IS_ADDR_V4MAPPED(&v6src)) {
1244 			udp->udp_ipversion = IPV4_VERSION;
1245 			udp->udp_max_hdr_len = IP_SIMPLE_HDR_LENGTH +
1246 			    UDPH_SIZE + udp->udp_ip_snd_options_len;
1247 		} else {
1248 			udp->udp_ipversion = IPV6_VERSION;
1249 			udp->udp_max_hdr_len = udp->udp_sticky_hdrs_len;
1250 		}
1251 	}
1252 
1253 	/*
1254 	 * If udp_reuseaddr is not set, then we have to make sure that
1255 	 * the IP address and port number the application requested
1256 	 * (or we selected for the application) is not being used by
1257 	 * another stream.  If another stream is already using the
1258 	 * requested IP address and port, the behavior depends on
1259 	 * "bind_to_req_port_only". If set the bind fails; otherwise we
1260 	 * search for any an unused port to bind to the the stream.
1261 	 *
1262 	 * As per the BSD semantics, as modified by the Deering multicast
1263 	 * changes, if udp_reuseaddr is set, then we allow multiple binds
1264 	 * to the same port independent of the local IP address.
1265 	 *
1266 	 * This is slightly different than in SunOS 4.X which did not
1267 	 * support IP multicast. Note that the change implemented by the
1268 	 * Deering multicast code effects all binds - not only binding
1269 	 * to IP multicast addresses.
1270 	 *
1271 	 * Note that when binding to port zero we ignore SO_REUSEADDR in
1272 	 * order to guarantee a unique port.
1273 	 */
1274 
1275 	count = 0;
1276 	if (udp->udp_anon_priv_bind) {
1277 		/* loopmax = (IPPORT_RESERVED-1) - udp_min_anonpriv_port + 1 */
1278 		loopmax = IPPORT_RESERVED - udp_min_anonpriv_port;
1279 	} else {
1280 		loopmax = udp_largest_anon_port - udp_smallest_anon_port + 1;
1281 	}
1282 
1283 	zoneid = connp->conn_zoneid;
1284 	for (;;) {
1285 		udp_t		*udp1;
1286 		boolean_t	is_inaddr_any;
1287 		boolean_t	found_exclbind = B_FALSE;
1288 
1289 		is_inaddr_any = V6_OR_V4_INADDR_ANY(v6src);
1290 		/*
1291 		 * Walk through the list of udp streams bound to
1292 		 * requested port with the same IP address.
1293 		 */
1294 		lport = htons(port);
1295 		udpf = &udp_bind_fanout[UDP_BIND_HASH(lport)];
1296 		mutex_enter(&udpf->uf_lock);
1297 		for (udp1 = udpf->uf_udp; udp1 != NULL;
1298 		    udp1 = udp1->udp_bind_hash) {
1299 			if (lport != udp1->udp_port ||
1300 			    zoneid != udp1->udp_connp->conn_zoneid)
1301 				continue;
1302 
1303 			/*
1304 			 * If UDP_EXCLBIND is set for either the bound or
1305 			 * binding endpoint, the semantics of bind
1306 			 * is changed according to the following chart.
1307 			 *
1308 			 * spec = specified address (v4 or v6)
1309 			 * unspec = unspecified address (v4 or v6)
1310 			 * A = specified addresses are different for endpoints
1311 			 *
1312 			 * bound	bind to		allowed?
1313 			 * -------------------------------------
1314 			 * unspec	unspec		no
1315 			 * unspec	spec		no
1316 			 * spec		unspec		no
1317 			 * spec		spec		yes if A
1318 			 */
1319 			if (udp1->udp_exclbind || udp->udp_exclbind) {
1320 				if (V6_OR_V4_INADDR_ANY(
1321 				    udp1->udp_bound_v6src) ||
1322 				    is_inaddr_any ||
1323 				    IN6_ARE_ADDR_EQUAL(&udp1->udp_bound_v6src,
1324 				    &v6src)) {
1325 					found_exclbind = B_TRUE;
1326 					break;
1327 				}
1328 				continue;
1329 			}
1330 
1331 			/*
1332 			 * Check ipversion to allow IPv4 and IPv6 sockets to
1333 			 * have disjoint port number spaces.
1334 			 */
1335 			if (udp->udp_ipversion != udp1->udp_ipversion)
1336 				continue;
1337 
1338 			/*
1339 			 * No difference depending on SO_REUSEADDR.
1340 			 *
1341 			 * If existing port is bound to a
1342 			 * non-wildcard IP address and
1343 			 * the requesting stream is bound to
1344 			 * a distinct different IP addresses
1345 			 * (non-wildcard, also), keep going.
1346 			 */
1347 			if (!is_inaddr_any &&
1348 			    !V6_OR_V4_INADDR_ANY(udp1->udp_bound_v6src) &&
1349 			    !IN6_ARE_ADDR_EQUAL(&udp1->udp_bound_v6src,
1350 			    &v6src)) {
1351 				continue;
1352 			}
1353 			break;
1354 		}
1355 
1356 		if (!found_exclbind &&
1357 		    (udp->udp_reuseaddr && requested_port != 0)) {
1358 			break;
1359 		}
1360 
1361 		if (udp1 == NULL) {
1362 			/*
1363 			 * No other stream has this IP address
1364 			 * and port number. We can use it.
1365 			 */
1366 			break;
1367 		}
1368 		mutex_exit(&udpf->uf_lock);
1369 		if (bind_to_req_port_only) {
1370 			/*
1371 			 * We get here only when requested port
1372 			 * is bound (and only first  of the for()
1373 			 * loop iteration).
1374 			 *
1375 			 * The semantics of this bind request
1376 			 * require it to fail so we return from
1377 			 * the routine (and exit the loop).
1378 			 *
1379 			 */
1380 			udp_err_ack(q, mp, TADDRBUSY, 0);
1381 			return;
1382 		}
1383 
1384 		if (udp->udp_anon_priv_bind) {
1385 			port = udp_get_next_priv_port();
1386 		} else {
1387 			if ((count == 0) && (requested_port != 0)) {
1388 				/*
1389 				 * If the application wants us to find
1390 				 * a port, get one to start with. Set
1391 				 * requested_port to 0, so that we will
1392 				 * update udp_g_next_port_to_try below.
1393 				 */
1394 				port = udp_update_next_port(
1395 				    udp_g_next_port_to_try, B_TRUE);
1396 				requested_port = 0;
1397 			} else {
1398 				port = udp_update_next_port(port + 1, B_FALSE);
1399 			}
1400 		}
1401 
1402 		if (++count >= loopmax) {
1403 			/*
1404 			 * We've tried every possible port number and
1405 			 * there are none available, so send an error
1406 			 * to the user.
1407 			 */
1408 			udp_err_ack(q, mp, TNOADDR, 0);
1409 			return;
1410 		}
1411 	}
1412 
1413 	/*
1414 	 * Copy the source address into our udp structure.  This address
1415 	 * may still be zero; if so, ip will fill in the correct address
1416 	 * each time an outbound packet is passed to it.
1417 	 * If we are binding to a broadcast or multicast address udp_rput
1418 	 * will clear the source address when it receives the T_BIND_ACK.
1419 	 */
1420 	udp->udp_v6src = udp->udp_bound_v6src = v6src;
1421 	udp->udp_port = lport;
1422 	/*
1423 	 * Now reset the the next anonymous port if the application requested
1424 	 * an anonymous port, or we handed out the next anonymous port.
1425 	 */
1426 	if ((requested_port == 0) && (!udp->udp_anon_priv_bind)) {
1427 		udp_g_next_port_to_try = port + 1;
1428 	}
1429 
1430 	/* Initialize the O_T_BIND_REQ/T_BIND_REQ for ip. */
1431 	if (udp->udp_family == AF_INET) {
1432 		sin->sin_port = udp->udp_port;
1433 	} else {
1434 		int error;
1435 
1436 		sin6->sin6_port = udp->udp_port;
1437 		/* Rebuild the header template */
1438 		error = udp_build_hdrs(q, udp);
1439 		if (error != 0) {
1440 			mutex_exit(&udpf->uf_lock);
1441 			udp_err_ack(q, mp, TSYSERR, error);
1442 			return;
1443 		}
1444 	}
1445 	udp->udp_state = TS_IDLE;
1446 	udp_bind_hash_insert(udpf, udp);
1447 	mutex_exit(&udpf->uf_lock);
1448 
1449 	if (cl_inet_bind) {
1450 		/*
1451 		 * Running in cluster mode - register bind information
1452 		 */
1453 		if (udp->udp_ipversion == IPV4_VERSION) {
1454 			(*cl_inet_bind)(IPPROTO_UDP, AF_INET,
1455 			    (uint8_t *)(&V4_PART_OF_V6(udp->udp_v6src)),
1456 			    (in_port_t)udp->udp_port);
1457 		} else {
1458 			(*cl_inet_bind)(IPPROTO_UDP, AF_INET6,
1459 			    (uint8_t *)&(udp->udp_v6src),
1460 			    (in_port_t)udp->udp_port);
1461 		}
1462 
1463 	}
1464 
1465 	/* Pass the protocol number in the message following the address. */
1466 	*mp->b_wptr++ = IPPROTO_UDP;
1467 	if (!V6_OR_V4_INADDR_ANY(udp->udp_v6src)) {
1468 		/*
1469 		 * Append a request for an IRE if udp_v6src not
1470 		 * zero (IPv4 - INADDR_ANY, or IPv6 - all-zeroes address).
1471 		 */
1472 		mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
1473 		if (!mp->b_cont) {
1474 			udp_err_ack(q, mp, TSYSERR, ENOMEM);
1475 			return;
1476 		}
1477 		mp->b_cont->b_wptr += sizeof (ire_t);
1478 		mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
1479 	}
1480 	if (udp->udp_family == AF_INET6)
1481 		mp = ip_bind_v6(q, mp, connp, NULL);
1482 	else
1483 		mp = ip_bind_v4(q, mp, connp);
1484 
1485 	if (mp != NULL)
1486 		udp_rput_other(_RD(q), mp);
1487 	else
1488 		CONN_INC_REF(connp);
1489 }
1490 
1491 
1492 void
1493 udp_resume_bind(conn_t *connp, mblk_t *mp)
1494 {
1495 	udp_enter(connp, mp, udp_resume_bind_cb, SQTAG_BIND_RETRY);
1496 }
1497 
1498 /*
1499  * This is called from ip_wput_nondata to resume a deferred UDP bind.
1500  */
1501 /* ARGSUSED */
1502 static void
1503 udp_resume_bind_cb(void *arg, mblk_t *mp, void *arg2)
1504 {
1505 	conn_t *connp = arg;
1506 
1507 	ASSERT(connp != NULL && IPCL_IS_UDP(connp));
1508 
1509 	udp_rput_other(connp->conn_rq, mp);
1510 
1511 	CONN_OPER_PENDING_DONE(connp);
1512 	udp_exit(connp);
1513 }
1514 
1515 /*
1516  * This routine handles each T_CONN_REQ message passed to udp.  It
1517  * associates a default destination address with the stream.
1518  *
1519  * This routine sends down a T_BIND_REQ to IP with the following mblks:
1520  *	T_BIND_REQ	- specifying local and remote address/port
1521  *	IRE_DB_REQ_TYPE	- to get an IRE back containing ire_type and src
1522  *	T_OK_ACK	- for the T_CONN_REQ
1523  *	T_CONN_CON	- to keep the TPI user happy
1524  *
1525  * The connect completes in udp_rput.
1526  * When a T_BIND_ACK is received information is extracted from the IRE
1527  * and the two appended messages are sent to the TPI user.
1528  * Should udp_rput receive T_ERROR_ACK for the T_BIND_REQ it will convert
1529  * it to an error ack for the appropriate primitive.
1530  */
1531 static void
1532 udp_connect(queue_t *q, mblk_t *mp)
1533 {
1534 	sin6_t	*sin6;
1535 	sin_t	*sin;
1536 	struct T_conn_req	*tcr;
1537 	in6_addr_t v6dst;
1538 	ipaddr_t v4dst;
1539 	uint16_t dstport;
1540 	uint32_t flowinfo;
1541 	mblk_t	*mp1, *mp2;
1542 	udp_fanout_t	*udpf;
1543 	udp_t	*udp, *udp1;
1544 
1545 	udp = Q_TO_UDP(q);
1546 
1547 	tcr = (struct T_conn_req *)mp->b_rptr;
1548 
1549 	/* A bit of sanity checking */
1550 	if ((mp->b_wptr - mp->b_rptr) < sizeof (struct T_conn_req)) {
1551 		udp_err_ack(q, mp, TPROTO, 0);
1552 		return;
1553 	}
1554 	/*
1555 	 * This UDP must have bound to a port already before doing
1556 	 * a connect.
1557 	 */
1558 	if (udp->udp_state == TS_UNBND) {
1559 		(void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
1560 		    "udp_connect: bad state, %u", udp->udp_state);
1561 		udp_err_ack(q, mp, TOUTSTATE, 0);
1562 		return;
1563 	}
1564 	ASSERT(udp->udp_port != 0 && udp->udp_ptpbhn != NULL);
1565 
1566 	udpf = &udp_bind_fanout[UDP_BIND_HASH(udp->udp_port)];
1567 
1568 	if (udp->udp_state == TS_DATA_XFER) {
1569 		/* Already connected - clear out state */
1570 		mutex_enter(&udpf->uf_lock);
1571 		udp->udp_v6src = udp->udp_bound_v6src;
1572 		udp->udp_state = TS_IDLE;
1573 		mutex_exit(&udpf->uf_lock);
1574 	}
1575 
1576 	if (tcr->OPT_length != 0) {
1577 		udp_err_ack(q, mp, TBADOPT, 0);
1578 		return;
1579 	}
1580 
1581 	/*
1582 	 * Determine packet type based on type of address passed in
1583 	 * the request should contain an IPv4 or IPv6 address.
1584 	 * Make sure that address family matches the type of
1585 	 * family of the the address passed down
1586 	 */
1587 	switch (tcr->DEST_length) {
1588 	default:
1589 		udp_err_ack(q, mp, TBADADDR, 0);
1590 		return;
1591 
1592 	case sizeof (sin_t):
1593 		sin = (sin_t *)mi_offset_param(mp, tcr->DEST_offset,
1594 		    sizeof (sin_t));
1595 		if (sin == NULL || !OK_32PTR((char *)sin)) {
1596 			udp_err_ack(q, mp, TSYSERR, EINVAL);
1597 			return;
1598 		}
1599 		if (udp->udp_family != AF_INET ||
1600 		    sin->sin_family != AF_INET) {
1601 			udp_err_ack(q, mp, TSYSERR, EAFNOSUPPORT);
1602 			return;
1603 		}
1604 		v4dst = sin->sin_addr.s_addr;
1605 		dstport = sin->sin_port;
1606 		IN6_IPADDR_TO_V4MAPPED(v4dst, &v6dst);
1607 		ASSERT(udp->udp_ipversion == IPV4_VERSION);
1608 		udp->udp_max_hdr_len = IP_SIMPLE_HDR_LENGTH + UDPH_SIZE +
1609 		    udp->udp_ip_snd_options_len;
1610 		break;
1611 
1612 	case sizeof (sin6_t):
1613 		sin6 = (sin6_t *)mi_offset_param(mp, tcr->DEST_offset,
1614 		    sizeof (sin6_t));
1615 		if (sin6 == NULL || !OK_32PTR((char *)sin6)) {
1616 			udp_err_ack(q, mp, TSYSERR, EINVAL);
1617 			return;
1618 		}
1619 		if (udp->udp_family != AF_INET6 ||
1620 		    sin6->sin6_family != AF_INET6) {
1621 			udp_err_ack(q, mp, TSYSERR, EAFNOSUPPORT);
1622 			return;
1623 		}
1624 		v6dst = sin6->sin6_addr;
1625 		if (IN6_IS_ADDR_V4MAPPED(&v6dst)) {
1626 			IN6_V4MAPPED_TO_IPADDR(&v6dst, v4dst);
1627 			udp->udp_ipversion = IPV4_VERSION;
1628 			udp->udp_max_hdr_len = IP_SIMPLE_HDR_LENGTH +
1629 			    UDPH_SIZE + udp->udp_ip_snd_options_len;
1630 			flowinfo = 0;
1631 		} else {
1632 			udp->udp_ipversion = IPV6_VERSION;
1633 			udp->udp_max_hdr_len = udp->udp_sticky_hdrs_len;
1634 			flowinfo = sin6->sin6_flowinfo;
1635 		}
1636 		dstport = sin6->sin6_port;
1637 		break;
1638 	}
1639 	if (dstport == 0) {
1640 		udp_err_ack(q, mp, TBADADDR, 0);
1641 		return;
1642 	}
1643 
1644 	/*
1645 	 * Create a default IP header with no IP options.
1646 	 */
1647 	udp->udp_dstport = dstport;
1648 	if (udp->udp_ipversion == IPV4_VERSION) {
1649 		/*
1650 		 * Interpret a zero destination to mean loopback.
1651 		 * Update the T_CONN_REQ (sin/sin6) since it is used to
1652 		 * generate the T_CONN_CON.
1653 		 */
1654 		if (v4dst == INADDR_ANY) {
1655 			v4dst = htonl(INADDR_LOOPBACK);
1656 			IN6_IPADDR_TO_V4MAPPED(v4dst, &v6dst);
1657 			if (udp->udp_family == AF_INET) {
1658 				sin->sin_addr.s_addr = v4dst;
1659 			} else {
1660 				sin6->sin6_addr = v6dst;
1661 			}
1662 		}
1663 		udp->udp_v6dst = v6dst;
1664 		udp->udp_flowinfo = 0;
1665 
1666 		/*
1667 		 * If the destination address is multicast and
1668 		 * an outgoing multicast interface has been set,
1669 		 * use the address of that interface as our
1670 		 * source address if no source address has been set.
1671 		 */
1672 		if (V4_PART_OF_V6(udp->udp_v6src) == INADDR_ANY &&
1673 		    CLASSD(v4dst) &&
1674 		    udp->udp_multicast_if_addr != INADDR_ANY) {
1675 			IN6_IPADDR_TO_V4MAPPED(udp->udp_multicast_if_addr,
1676 			    &udp->udp_v6src);
1677 		}
1678 	} else {
1679 		ASSERT(udp->udp_ipversion == IPV6_VERSION);
1680 		/*
1681 		 * Interpret a zero destination to mean loopback.
1682 		 * Update the T_CONN_REQ (sin/sin6) since it is used to
1683 		 * generate the T_CONN_CON.
1684 		 */
1685 		if (IN6_IS_ADDR_UNSPECIFIED(&v6dst)) {
1686 			v6dst = ipv6_loopback;
1687 			sin6->sin6_addr = v6dst;
1688 		}
1689 		udp->udp_v6dst = v6dst;
1690 		udp->udp_flowinfo = flowinfo;
1691 		/*
1692 		 * If the destination address is multicast and
1693 		 * an outgoing multicast interface has been set,
1694 		 * then the ip bind logic will pick the correct source
1695 		 * address (i.e. matching the outgoing multicast interface).
1696 		 */
1697 	}
1698 
1699 	/*
1700 	 * Verify that the src/port/dst/port is unique for all
1701 	 * connections in TS_DATA_XFER
1702 	 */
1703 	mutex_enter(&udpf->uf_lock);
1704 	for (udp1 = udpf->uf_udp; udp1 != NULL; udp1 = udp1->udp_bind_hash) {
1705 		if (udp1->udp_state != TS_DATA_XFER)
1706 			continue;
1707 		if (udp->udp_port != udp1->udp_port ||
1708 		    udp->udp_ipversion != udp1->udp_ipversion ||
1709 		    dstport != udp1->udp_dstport ||
1710 		    !IN6_ARE_ADDR_EQUAL(&udp->udp_v6src, &udp1->udp_v6src) ||
1711 		    !IN6_ARE_ADDR_EQUAL(&v6dst, &udp1->udp_v6dst))
1712 			continue;
1713 		mutex_exit(&udpf->uf_lock);
1714 		udp_err_ack(q, mp, TBADADDR, 0);
1715 		return;
1716 	}
1717 	udp->udp_state = TS_DATA_XFER;
1718 	mutex_exit(&udpf->uf_lock);
1719 
1720 	/*
1721 	 * Send down bind to IP to verify that there is a route
1722 	 * and to determine the source address.
1723 	 * This will come back as T_BIND_ACK with an IRE_DB_TYPE in rput.
1724 	 */
1725 	if (udp->udp_family == AF_INET)
1726 		mp1 = udp_ip_bind_mp(udp, O_T_BIND_REQ, sizeof (ipa_conn_t));
1727 	else
1728 		mp1 = udp_ip_bind_mp(udp, O_T_BIND_REQ, sizeof (ipa6_conn_t));
1729 	if (mp1 == NULL) {
1730 		udp_err_ack(q, mp, TSYSERR, ENOMEM);
1731 bind_failed:
1732 		mutex_enter(&udpf->uf_lock);
1733 		udp->udp_state = TS_IDLE;
1734 		mutex_exit(&udpf->uf_lock);
1735 		return;
1736 	}
1737 
1738 	/*
1739 	 * We also have to send a connection confirmation to
1740 	 * keep TLI happy. Prepare it for udp_rput.
1741 	 */
1742 	if (udp->udp_family == AF_INET)
1743 		mp2 = mi_tpi_conn_con(NULL, (char *)sin,
1744 		    sizeof (*sin), NULL, 0);
1745 	else
1746 		mp2 = mi_tpi_conn_con(NULL, (char *)sin6,
1747 		    sizeof (*sin6), NULL, 0);
1748 	if (mp2 == NULL) {
1749 		freemsg(mp1);
1750 		udp_err_ack(q, mp, TSYSERR, ENOMEM);
1751 		goto bind_failed;
1752 	}
1753 
1754 	mp = mi_tpi_ok_ack_alloc(mp);
1755 	if (mp == NULL) {
1756 		/* Unable to reuse the T_CONN_REQ for the ack. */
1757 		freemsg(mp2);
1758 		udp_err_ack_prim(q, mp1, T_CONN_REQ, TSYSERR, ENOMEM);
1759 		goto bind_failed;
1760 	}
1761 
1762 	/* Hang onto the T_OK_ACK and T_CONN_CON for later. */
1763 	linkb(mp1, mp);
1764 	linkb(mp1, mp2);
1765 
1766 	if (udp->udp_family == AF_INET)
1767 		mp1 = ip_bind_v4(q, mp1, udp->udp_connp);
1768 	else
1769 		mp1 = ip_bind_v6(q, mp1, udp->udp_connp, NULL);
1770 
1771 	if (mp1 != NULL)
1772 		udp_rput_other(_RD(q), mp1);
1773 	else
1774 		CONN_INC_REF(udp->udp_connp);
1775 }
1776 
1777 static int
1778 udp_close(queue_t *q)
1779 {
1780 	conn_t	*connp = Q_TO_CONN(UDP_WR(q));
1781 	udp_t	*udp;
1782 	queue_t	*ip_rq = RD(UDP_WR(q));
1783 
1784 	ASSERT(connp != NULL && IPCL_IS_UDP(connp));
1785 	udp = connp->conn_udp;
1786 
1787 	ip_quiesce_conn(connp);
1788 	/*
1789 	 * Disable read-side synchronous stream
1790 	 * interface and drain any queued data.
1791 	 */
1792 	udp_rcv_drain(q, udp, B_TRUE);
1793 	ASSERT(!udp->udp_direct_sockfs);
1794 
1795 	qprocsoff(q);
1796 
1797 	/* restore IP module's high and low water marks to default values */
1798 	ip_rq->q_hiwat = ip_rq->q_qinfo->qi_minfo->mi_hiwat;
1799 	WR(ip_rq)->q_hiwat = WR(ip_rq)->q_qinfo->qi_minfo->mi_hiwat;
1800 	WR(ip_rq)->q_lowat = WR(ip_rq)->q_qinfo->qi_minfo->mi_lowat;
1801 
1802 	ASSERT(udp->udp_rcv_cnt == 0);
1803 	ASSERT(udp->udp_rcv_msgcnt == 0);
1804 	ASSERT(udp->udp_rcv_list_head == NULL);
1805 	ASSERT(udp->udp_rcv_list_tail == NULL);
1806 
1807 	/* connp is now single threaded. */
1808 	udp_close_free(connp);
1809 	/*
1810 	 * Restore connp as an IP endpoint.  We don't need
1811 	 * any locks since we are now single threaded
1812 	 */
1813 	connp->conn_flags &= ~IPCL_UDP;
1814 	connp->conn_state_flags &=
1815 	    ~(CONN_CLOSING | CONN_CONDEMNED | CONN_QUIESCED);
1816 	return (0);
1817 }
1818 
1819 /*
1820  * Called in the close path from IP (ip_quiesce_conn) to quiesce the conn
1821  */
1822 void
1823 udp_quiesce_conn(conn_t *connp)
1824 {
1825 	udp_t	*udp = connp->conn_udp;
1826 
1827 	if (cl_inet_unbind != NULL && udp->udp_state == TS_IDLE) {
1828 		/*
1829 		 * Running in cluster mode - register unbind information
1830 		 */
1831 		if (udp->udp_ipversion == IPV4_VERSION) {
1832 			(*cl_inet_unbind)(IPPROTO_UDP, AF_INET,
1833 			    (uint8_t *)(&(V4_PART_OF_V6(udp->udp_v6src))),
1834 			    (in_port_t)udp->udp_port);
1835 		} else {
1836 			(*cl_inet_unbind)(IPPROTO_UDP, AF_INET6,
1837 			    (uint8_t *)(&(udp->udp_v6src)),
1838 			    (in_port_t)udp->udp_port);
1839 		}
1840 	}
1841 
1842 	udp_bind_hash_remove(udp, B_FALSE);
1843 
1844 	mutex_enter(&connp->conn_lock);
1845 	while (udp->udp_reader_count != 0 || udp->udp_squeue_count != 0 ||
1846 	    udp->udp_mode != UDP_MT_HOT) {
1847 		cv_wait(&connp->conn_cv, &connp->conn_lock);
1848 	}
1849 	mutex_exit(&connp->conn_lock);
1850 }
1851 
1852 void
1853 udp_close_free(conn_t *connp)
1854 {
1855 	udp_t *udp = connp->conn_udp;
1856 
1857 	/* If there are any options associated with the stream, free them. */
1858 	if (udp->udp_ip_snd_options) {
1859 		mi_free((char *)udp->udp_ip_snd_options);
1860 		udp->udp_ip_snd_options = NULL;
1861 	}
1862 
1863 	if (udp->udp_ip_rcv_options) {
1864 		mi_free((char *)udp->udp_ip_rcv_options);
1865 		udp->udp_ip_rcv_options = NULL;
1866 	}
1867 
1868 	/* Free memory associated with sticky options */
1869 	if (udp->udp_sticky_hdrs_len != 0) {
1870 		kmem_free(udp->udp_sticky_hdrs,
1871 		    udp->udp_sticky_hdrs_len);
1872 		udp->udp_sticky_hdrs = NULL;
1873 		udp->udp_sticky_hdrs_len = 0;
1874 	}
1875 
1876 	if (udp->udp_sticky_ipp.ipp_fields & IPPF_HOPOPTS) {
1877 		kmem_free(udp->udp_sticky_ipp.ipp_hopopts,
1878 		    udp->udp_sticky_ipp.ipp_hopoptslen);
1879 		udp->udp_sticky_ipp.ipp_hopopts = NULL;
1880 	}
1881 	if (udp->udp_sticky_ipp.ipp_fields & IPPF_RTDSTOPTS) {
1882 		kmem_free(udp->udp_sticky_ipp.ipp_rtdstopts,
1883 		    udp->udp_sticky_ipp.ipp_rtdstoptslen);
1884 		udp->udp_sticky_ipp.ipp_rtdstopts = NULL;
1885 	}
1886 	if (udp->udp_sticky_ipp.ipp_fields & IPPF_RTHDR) {
1887 		kmem_free(udp->udp_sticky_ipp.ipp_rthdr,
1888 		    udp->udp_sticky_ipp.ipp_rthdrlen);
1889 		udp->udp_sticky_ipp.ipp_rthdr = NULL;
1890 	}
1891 	if (udp->udp_sticky_ipp.ipp_fields & IPPF_DSTOPTS) {
1892 		kmem_free(udp->udp_sticky_ipp.ipp_dstopts,
1893 		    udp->udp_sticky_ipp.ipp_dstoptslen);
1894 		udp->udp_sticky_ipp.ipp_dstopts = NULL;
1895 	}
1896 	udp->udp_sticky_ipp.ipp_fields &=
1897 	    ~(IPPF_HOPOPTS|IPPF_RTDSTOPTS|IPPF_RTHDR|IPPF_DSTOPTS);
1898 
1899 	udp->udp_connp = NULL;
1900 	connp->conn_udp = NULL;
1901 	kmem_cache_free(udp_cache, udp);
1902 }
1903 
1904 /*
1905  * This routine handles each T_DISCON_REQ message passed to udp
1906  * as an indicating that UDP is no longer connected. This results
1907  * in sending a T_BIND_REQ to IP to restore the binding to just
1908  * the local address/port.
1909  *
1910  * This routine sends down a T_BIND_REQ to IP with the following mblks:
1911  *	T_BIND_REQ	- specifying just the local address/port
1912  *	T_OK_ACK	- for the T_DISCON_REQ
1913  *
1914  * The disconnect completes in udp_rput.
1915  * When a T_BIND_ACK is received the appended T_OK_ACK is sent to the TPI user.
1916  * Should udp_rput receive T_ERROR_ACK for the T_BIND_REQ it will convert
1917  * it to an error ack for the appropriate primitive.
1918  */
1919 static void
1920 udp_disconnect(queue_t *q, mblk_t *mp)
1921 {
1922 	udp_t	*udp = Q_TO_UDP(q);
1923 	mblk_t	*mp1;
1924 	udp_fanout_t *udpf;
1925 
1926 	if (udp->udp_state != TS_DATA_XFER) {
1927 		(void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
1928 		    "udp_disconnect: bad state, %u", udp->udp_state);
1929 		udp_err_ack(q, mp, TOUTSTATE, 0);
1930 		return;
1931 	}
1932 	udpf = &udp_bind_fanout[UDP_BIND_HASH(udp->udp_port)];
1933 	mutex_enter(&udpf->uf_lock);
1934 	udp->udp_v6src = udp->udp_bound_v6src;
1935 	udp->udp_state = TS_IDLE;
1936 	mutex_exit(&udpf->uf_lock);
1937 
1938 	/*
1939 	 * Send down bind to IP to remove the full binding and revert
1940 	 * to the local address binding.
1941 	 */
1942 	if (udp->udp_family == AF_INET)
1943 		mp1 = udp_ip_bind_mp(udp, O_T_BIND_REQ, sizeof (sin_t));
1944 	else
1945 		mp1 = udp_ip_bind_mp(udp, O_T_BIND_REQ, sizeof (sin6_t));
1946 	if (mp1 == NULL) {
1947 		udp_err_ack(q, mp, TSYSERR, ENOMEM);
1948 		return;
1949 	}
1950 	mp = mi_tpi_ok_ack_alloc(mp);
1951 	if (mp == NULL) {
1952 		/* Unable to reuse the T_DISCON_REQ for the ack. */
1953 		udp_err_ack_prim(q, mp1, T_DISCON_REQ, TSYSERR, ENOMEM);
1954 		return;
1955 	}
1956 
1957 	if (udp->udp_family == AF_INET6) {
1958 		int error;
1959 
1960 		/* Rebuild the header template */
1961 		error = udp_build_hdrs(q, udp);
1962 		if (error != 0) {
1963 			udp_err_ack_prim(q, mp, T_DISCON_REQ, TSYSERR, error);
1964 			freemsg(mp1);
1965 			return;
1966 		}
1967 	}
1968 	mutex_enter(&udpf->uf_lock);
1969 	udp->udp_discon_pending = 1;
1970 	mutex_exit(&udpf->uf_lock);
1971 
1972 	/* Append the T_OK_ACK to the T_BIND_REQ for udp_rput */
1973 	linkb(mp1, mp);
1974 
1975 	if (udp->udp_family == AF_INET6)
1976 		mp1 = ip_bind_v6(q, mp1, udp->udp_connp, NULL);
1977 	else
1978 		mp1 = ip_bind_v4(q, mp1, udp->udp_connp);
1979 
1980 	if (mp1 != NULL)
1981 		udp_rput_other(_RD(q), mp1);
1982 	else
1983 		CONN_INC_REF(udp->udp_connp);
1984 }
1985 
1986 /* This routine creates a T_ERROR_ACK message and passes it upstream. */
1987 static void
1988 udp_err_ack(queue_t *q, mblk_t *mp, t_scalar_t t_error, int sys_error)
1989 {
1990 	if ((mp = mi_tpi_err_ack_alloc(mp, t_error, sys_error)) != NULL)
1991 		putnext(UDP_RD(q), mp);
1992 }
1993 
1994 /* Shorthand to generate and send TPI error acks to our client */
1995 static void
1996 udp_err_ack_prim(queue_t *q, mblk_t *mp, int primitive, t_scalar_t t_error,
1997     int sys_error)
1998 {
1999 	struct T_error_ack	*teackp;
2000 
2001 	if ((mp = tpi_ack_alloc(mp, sizeof (struct T_error_ack),
2002 	    M_PCPROTO, T_ERROR_ACK)) != NULL) {
2003 		teackp = (struct T_error_ack *)mp->b_rptr;
2004 		teackp->ERROR_prim = primitive;
2005 		teackp->TLI_error = t_error;
2006 		teackp->UNIX_error = sys_error;
2007 		putnext(UDP_RD(q), mp);
2008 	}
2009 }
2010 
2011 /*ARGSUSED*/
2012 static int
2013 udp_extra_priv_ports_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr)
2014 {
2015 	int i;
2016 
2017 	for (i = 0; i < udp_g_num_epriv_ports; i++) {
2018 		if (udp_g_epriv_ports[i] != 0)
2019 			(void) mi_mpprintf(mp, "%d ", udp_g_epriv_ports[i]);
2020 	}
2021 	return (0);
2022 }
2023 
2024 /* ARGSUSED */
2025 static int
2026 udp_extra_priv_ports_add(queue_t *q, mblk_t *mp, char *value, caddr_t cp,
2027     cred_t *cr)
2028 {
2029 	long	new_value;
2030 	int	i;
2031 
2032 	/*
2033 	 * Fail the request if the new value does not lie within the
2034 	 * port number limits.
2035 	 */
2036 	if (ddi_strtol(value, NULL, 10, &new_value) != 0 ||
2037 	    new_value <= 0 || new_value >= 65536) {
2038 		return (EINVAL);
2039 	}
2040 
2041 	/* Check if the value is already in the list */
2042 	for (i = 0; i < udp_g_num_epriv_ports; i++) {
2043 		if (new_value == udp_g_epriv_ports[i]) {
2044 			return (EEXIST);
2045 		}
2046 	}
2047 	/* Find an empty slot */
2048 	for (i = 0; i < udp_g_num_epriv_ports; i++) {
2049 		if (udp_g_epriv_ports[i] == 0)
2050 			break;
2051 	}
2052 	if (i == udp_g_num_epriv_ports) {
2053 		return (EOVERFLOW);
2054 	}
2055 
2056 	/* Set the new value */
2057 	udp_g_epriv_ports[i] = (in_port_t)new_value;
2058 	return (0);
2059 }
2060 
2061 /* ARGSUSED */
2062 static int
2063 udp_extra_priv_ports_del(queue_t *q, mblk_t *mp, char *value, caddr_t cp,
2064     cred_t *cr)
2065 {
2066 	long	new_value;
2067 	int	i;
2068 
2069 	/*
2070 	 * Fail the request if the new value does not lie within the
2071 	 * port number limits.
2072 	 */
2073 	if (ddi_strtol(value, NULL, 10, &new_value) != 0 ||
2074 	    new_value <= 0 || new_value >= 65536) {
2075 		return (EINVAL);
2076 	}
2077 
2078 	/* Check that the value is already in the list */
2079 	for (i = 0; i < udp_g_num_epriv_ports; i++) {
2080 		if (udp_g_epriv_ports[i] == new_value)
2081 			break;
2082 	}
2083 	if (i == udp_g_num_epriv_ports) {
2084 		return (ESRCH);
2085 	}
2086 
2087 	/* Clear the value */
2088 	udp_g_epriv_ports[i] = 0;
2089 	return (0);
2090 }
2091 
2092 /* At minimum we need 4 bytes of UDP header */
2093 #define	ICMP_MIN_UDP_HDR	4
2094 
2095 /*
2096  * udp_icmp_error is called by udp_rput to process ICMP msgs. passed up by IP.
2097  * Generates the appropriate T_UDERROR_IND for permanent (non-transient) errors.
2098  * Assumes that IP has pulled up everything up to and including the ICMP header.
2099  * An M_CTL could potentially come here from some other module (i.e. if UDP
2100  * is pushed on some module other than IP). Thus, if we find that the M_CTL
2101  * does not have enough ICMP information , following STREAMS conventions,
2102  * we send it upstream assuming it is an M_CTL we don't understand.
2103  */
2104 static void
2105 udp_icmp_error(queue_t *q, mblk_t *mp)
2106 {
2107 	icmph_t *icmph;
2108 	ipha_t	*ipha;
2109 	int	iph_hdr_length;
2110 	udpha_t	*udpha;
2111 	sin_t	sin;
2112 	sin6_t	sin6;
2113 	mblk_t	*mp1;
2114 	int	error = 0;
2115 	size_t	mp_size = MBLKL(mp);
2116 	udp_t	*udp = Q_TO_UDP(q);
2117 
2118 	/*
2119 	 * Assume IP provides aligned packets - otherwise toss
2120 	 */
2121 	if (!OK_32PTR(mp->b_rptr)) {
2122 		freemsg(mp);
2123 		return;
2124 	}
2125 
2126 	/*
2127 	 * Verify that we have a complete IP header and the application has
2128 	 * asked for errors. If not, send it upstream.
2129 	 */
2130 	if (!udp->udp_dgram_errind || mp_size < sizeof (ipha_t)) {
2131 noticmpv4:
2132 		putnext(UDP_RD(q), mp);
2133 		return;
2134 	}
2135 
2136 	ipha = (ipha_t *)mp->b_rptr;
2137 	/*
2138 	 * Verify IP version. Anything other than IPv4 or IPv6 packet is sent
2139 	 * upstream. ICMPv6  is handled in udp_icmp_error_ipv6.
2140 	 */
2141 	switch (IPH_HDR_VERSION(ipha)) {
2142 	case IPV6_VERSION:
2143 		udp_icmp_error_ipv6(q, mp);
2144 		return;
2145 	case IPV4_VERSION:
2146 		break;
2147 	default:
2148 		goto noticmpv4;
2149 	}
2150 
2151 	/* Skip past the outer IP and ICMP headers */
2152 	iph_hdr_length = IPH_HDR_LENGTH(ipha);
2153 	icmph = (icmph_t *)&mp->b_rptr[iph_hdr_length];
2154 	/*
2155 	 * If we don't have the correct outer IP header length or if the ULP
2156 	 * is not IPPROTO_ICMP or if we don't have a complete inner IP header
2157 	 * send the packet upstream.
2158 	 */
2159 	if (iph_hdr_length < sizeof (ipha_t) ||
2160 	    ipha->ipha_protocol != IPPROTO_ICMP ||
2161 	    (ipha_t *)&icmph[1] + 1 > (ipha_t *)mp->b_wptr) {
2162 		goto noticmpv4;
2163 	}
2164 	ipha = (ipha_t *)&icmph[1];
2165 
2166 	/* Skip past the inner IP and find the ULP header */
2167 	iph_hdr_length = IPH_HDR_LENGTH(ipha);
2168 	udpha = (udpha_t *)((char *)ipha + iph_hdr_length);
2169 	/*
2170 	 * If we don't have the correct inner IP header length or if the ULP
2171 	 * is not IPPROTO_UDP or if we don't have at least ICMP_MIN_UDP_HDR
2172 	 * bytes of UDP header, send it upstream.
2173 	 */
2174 	if (iph_hdr_length < sizeof (ipha_t) ||
2175 	    ipha->ipha_protocol != IPPROTO_UDP ||
2176 	    (uchar_t *)udpha + ICMP_MIN_UDP_HDR > mp->b_wptr) {
2177 		goto noticmpv4;
2178 	}
2179 
2180 	switch (icmph->icmph_type) {
2181 	case ICMP_DEST_UNREACHABLE:
2182 		switch (icmph->icmph_code) {
2183 		case ICMP_FRAGMENTATION_NEEDED:
2184 			/*
2185 			 * IP has already adjusted the path MTU.
2186 			 * XXX Somehow pass MTU indication to application?
2187 			 */
2188 			break;
2189 		case ICMP_PORT_UNREACHABLE:
2190 		case ICMP_PROTOCOL_UNREACHABLE:
2191 			error = ECONNREFUSED;
2192 			break;
2193 		default:
2194 			/* Transient errors */
2195 			break;
2196 		}
2197 		break;
2198 	default:
2199 		/* Transient errors */
2200 		break;
2201 	}
2202 	if (error == 0) {
2203 		freemsg(mp);
2204 		return;
2205 	}
2206 
2207 	switch (udp->udp_family) {
2208 	case AF_INET:
2209 		sin = sin_null;
2210 		sin.sin_family = AF_INET;
2211 		sin.sin_addr.s_addr = ipha->ipha_dst;
2212 		sin.sin_port = udpha->uha_dst_port;
2213 		mp1 = mi_tpi_uderror_ind((char *)&sin, sizeof (sin_t), NULL, 0,
2214 		    error);
2215 		break;
2216 	case AF_INET6:
2217 		sin6 = sin6_null;
2218 		sin6.sin6_family = AF_INET6;
2219 		IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &sin6.sin6_addr);
2220 		sin6.sin6_port = udpha->uha_dst_port;
2221 
2222 		mp1 = mi_tpi_uderror_ind((char *)&sin6, sizeof (sin6_t),
2223 		    NULL, 0, error);
2224 		break;
2225 	}
2226 	if (mp1)
2227 		putnext(UDP_RD(q), mp1);
2228 	freemsg(mp);
2229 }
2230 
2231 /*
2232  * udp_icmp_error_ipv6 is called by udp_icmp_error to process ICMP for IPv6.
2233  * Generates the appropriate T_UDERROR_IND for permanent (non-transient) errors.
2234  * Assumes that IP has pulled up all the extension headers as well as the
2235  * ICMPv6 header.
2236  * An M_CTL could potentially come here from some other module (i.e. if UDP
2237  * is pushed on some module other than IP). Thus, if we find that the M_CTL
2238  * does not have enough ICMP information , following STREAMS conventions,
2239  * we send it upstream assuming it is an M_CTL we don't understand. The reason
2240  * it might get here is if the non-ICMP M_CTL accidently has 6 in the version
2241  * field (when cast to ipha_t in udp_icmp_error).
2242  */
2243 static void
2244 udp_icmp_error_ipv6(queue_t *q, mblk_t *mp)
2245 {
2246 	icmp6_t		*icmp6;
2247 	ip6_t		*ip6h, *outer_ip6h;
2248 	uint16_t	hdr_length;
2249 	uint8_t		*nexthdrp;
2250 	udpha_t		*udpha;
2251 	sin6_t		sin6;
2252 	mblk_t		*mp1;
2253 	int		error = 0;
2254 	size_t		mp_size = MBLKL(mp);
2255 	udp_t		*udp = Q_TO_UDP(q);
2256 
2257 	/*
2258 	 * Verify that we have a complete IP header. If not, send it upstream.
2259 	 */
2260 	if (mp_size < sizeof (ip6_t)) {
2261 noticmpv6:
2262 		putnext(UDP_RD(q), mp);
2263 		return;
2264 	}
2265 
2266 	outer_ip6h = (ip6_t *)mp->b_rptr;
2267 	/*
2268 	 * Verify this is an ICMPV6 packet, else send it upstream
2269 	 */
2270 	if (outer_ip6h->ip6_nxt == IPPROTO_ICMPV6) {
2271 		hdr_length = IPV6_HDR_LEN;
2272 	} else if (!ip_hdr_length_nexthdr_v6(mp, outer_ip6h, &hdr_length,
2273 	    &nexthdrp) ||
2274 	    *nexthdrp != IPPROTO_ICMPV6) {
2275 		goto noticmpv6;
2276 	}
2277 	icmp6 = (icmp6_t *)&mp->b_rptr[hdr_length];
2278 	ip6h = (ip6_t *)&icmp6[1];
2279 	/*
2280 	 * Verify we have a complete ICMP and inner IP header.
2281 	 */
2282 	if ((uchar_t *)&ip6h[1] > mp->b_wptr)
2283 		goto noticmpv6;
2284 
2285 	if (!ip_hdr_length_nexthdr_v6(mp, ip6h, &hdr_length, &nexthdrp))
2286 		goto noticmpv6;
2287 	udpha = (udpha_t *)((char *)ip6h + hdr_length);
2288 	/*
2289 	 * Validate inner header. If the ULP is not IPPROTO_UDP or if we don't
2290 	 * have at least ICMP_MIN_UDP_HDR bytes of  UDP header send the
2291 	 * packet upstream.
2292 	 */
2293 	if ((*nexthdrp != IPPROTO_UDP) ||
2294 	    ((uchar_t *)udpha + ICMP_MIN_UDP_HDR) > mp->b_wptr) {
2295 		goto noticmpv6;
2296 	}
2297 
2298 	switch (icmp6->icmp6_type) {
2299 	case ICMP6_DST_UNREACH:
2300 		switch (icmp6->icmp6_code) {
2301 		case ICMP6_DST_UNREACH_NOPORT:
2302 			error = ECONNREFUSED;
2303 			break;
2304 		case ICMP6_DST_UNREACH_ADMIN:
2305 		case ICMP6_DST_UNREACH_NOROUTE:
2306 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
2307 		case ICMP6_DST_UNREACH_ADDR:
2308 			/* Transient errors */
2309 			break;
2310 		default:
2311 			break;
2312 		}
2313 		break;
2314 	case ICMP6_PACKET_TOO_BIG: {
2315 		struct T_unitdata_ind	*tudi;
2316 		struct T_opthdr		*toh;
2317 		size_t			udi_size;
2318 		mblk_t			*newmp;
2319 		t_scalar_t		opt_length = sizeof (struct T_opthdr) +
2320 		    sizeof (struct ip6_mtuinfo);
2321 		sin6_t			*sin6;
2322 		struct ip6_mtuinfo	*mtuinfo;
2323 
2324 		/*
2325 		 * If the application has requested to receive path mtu
2326 		 * information, send up an empty message containing an
2327 		 * IPV6_PATHMTU ancillary data item.
2328 		 */
2329 		if (!udp->udp_ipv6_recvpathmtu)
2330 			break;
2331 
2332 		udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin6_t) +
2333 		    opt_length;
2334 		if ((newmp = allocb(udi_size, BPRI_MED)) == NULL) {
2335 			BUMP_MIB(&udp_mib, udpInErrors);
2336 			break;
2337 		}
2338 
2339 		/*
2340 		 * newmp->b_cont is left to NULL on purpose.  This is an
2341 		 * empty message containing only ancillary data.
2342 		 */
2343 		newmp->b_datap->db_type = M_PROTO;
2344 		tudi = (struct T_unitdata_ind *)newmp->b_rptr;
2345 		newmp->b_wptr = (uchar_t *)tudi + udi_size;
2346 		tudi->PRIM_type = T_UNITDATA_IND;
2347 		tudi->SRC_length = sizeof (sin6_t);
2348 		tudi->SRC_offset = sizeof (struct T_unitdata_ind);
2349 		tudi->OPT_offset = tudi->SRC_offset + sizeof (sin6_t);
2350 		tudi->OPT_length = opt_length;
2351 
2352 		sin6 = (sin6_t *)&tudi[1];
2353 		bzero(sin6, sizeof (sin6_t));
2354 		sin6->sin6_family = AF_INET6;
2355 		sin6->sin6_addr = udp->udp_v6dst;
2356 
2357 		toh = (struct T_opthdr *)&sin6[1];
2358 		toh->level = IPPROTO_IPV6;
2359 		toh->name = IPV6_PATHMTU;
2360 		toh->len = opt_length;
2361 		toh->status = 0;
2362 
2363 		mtuinfo = (struct ip6_mtuinfo *)&toh[1];
2364 		bzero(mtuinfo, sizeof (struct ip6_mtuinfo));
2365 		mtuinfo->ip6m_addr.sin6_family = AF_INET6;
2366 		mtuinfo->ip6m_addr.sin6_addr = ip6h->ip6_dst;
2367 		mtuinfo->ip6m_mtu = icmp6->icmp6_mtu;
2368 		/*
2369 		 * We've consumed everything we need from the original
2370 		 * message.  Free it, then send our empty message.
2371 		 */
2372 		freemsg(mp);
2373 		putnext(UDP_RD(q), newmp);
2374 		return;
2375 	}
2376 	case ICMP6_TIME_EXCEEDED:
2377 		/* Transient errors */
2378 		break;
2379 	case ICMP6_PARAM_PROB:
2380 		/* If this corresponds to an ICMP_PROTOCOL_UNREACHABLE */
2381 		if (icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER &&
2382 		    (uchar_t *)ip6h + icmp6->icmp6_pptr ==
2383 		    (uchar_t *)nexthdrp) {
2384 			error = ECONNREFUSED;
2385 			break;
2386 		}
2387 		break;
2388 	}
2389 	if (error == 0) {
2390 		freemsg(mp);
2391 		return;
2392 	}
2393 
2394 	sin6 = sin6_null;
2395 	sin6.sin6_family = AF_INET6;
2396 	sin6.sin6_addr = ip6h->ip6_dst;
2397 	sin6.sin6_port = udpha->uha_dst_port;
2398 	sin6.sin6_flowinfo = ip6h->ip6_vcf & ~IPV6_VERS_AND_FLOW_MASK;
2399 
2400 	mp1 = mi_tpi_uderror_ind((char *)&sin6, sizeof (sin6_t), NULL, 0,
2401 	    error);
2402 	if (mp1)
2403 		putnext(UDP_RD(q), mp1);
2404 	freemsg(mp);
2405 }
2406 
2407 /*
2408  * This routine responds to T_ADDR_REQ messages.  It is called by udp_wput.
2409  * The local address is filled in if endpoint is bound. The remote address
2410  * is filled in if remote address has been precified ("connected endpoint")
2411  * (The concept of connected CLTS sockets is alien to published TPI
2412  *  but we support it anyway).
2413  */
2414 static void
2415 udp_addr_req(queue_t *q, mblk_t *mp)
2416 {
2417 	sin_t	*sin;
2418 	sin6_t	*sin6;
2419 	mblk_t	*ackmp;
2420 	struct T_addr_ack *taa;
2421 	udp_t	*udp = Q_TO_UDP(q);
2422 
2423 	/* Make it large enough for worst case */
2424 	ackmp = reallocb(mp, sizeof (struct T_addr_ack) +
2425 	    2 * sizeof (sin6_t), 1);
2426 	if (ackmp == NULL) {
2427 		udp_err_ack(q, mp, TSYSERR, ENOMEM);
2428 		return;
2429 	}
2430 	taa = (struct T_addr_ack *)ackmp->b_rptr;
2431 
2432 	bzero(taa, sizeof (struct T_addr_ack));
2433 	ackmp->b_wptr = (uchar_t *)&taa[1];
2434 
2435 	taa->PRIM_type = T_ADDR_ACK;
2436 	ackmp->b_datap->db_type = M_PCPROTO;
2437 	/*
2438 	 * Note: Following code assumes 32 bit alignment of basic
2439 	 * data structures like sin_t and struct T_addr_ack.
2440 	 */
2441 	if (udp->udp_state != TS_UNBND) {
2442 		/*
2443 		 * Fill in local address first
2444 		 */
2445 		taa->LOCADDR_offset = sizeof (*taa);
2446 		if (udp->udp_family == AF_INET) {
2447 			taa->LOCADDR_length = sizeof (sin_t);
2448 			sin = (sin_t *)&taa[1];
2449 			/* Fill zeroes and then initialize non-zero fields */
2450 			*sin = sin_null;
2451 			sin->sin_family = AF_INET;
2452 			if (!IN6_IS_ADDR_V4MAPPED_ANY(&udp->udp_v6src) &&
2453 			    !IN6_IS_ADDR_UNSPECIFIED(&udp->udp_v6src)) {
2454 				IN6_V4MAPPED_TO_IPADDR(&udp->udp_v6src,
2455 				    sin->sin_addr.s_addr);
2456 			} else {
2457 				/*
2458 				 * INADDR_ANY
2459 				 * udp_v6src is not set, we might be bound to
2460 				 * broadcast/multicast. Use udp_bound_v6src as
2461 				 * local address instead (that could
2462 				 * also still be INADDR_ANY)
2463 				 */
2464 				IN6_V4MAPPED_TO_IPADDR(&udp->udp_bound_v6src,
2465 				    sin->sin_addr.s_addr);
2466 			}
2467 			sin->sin_port = udp->udp_port;
2468 			ackmp->b_wptr = (uchar_t *)&sin[1];
2469 			if (udp->udp_state == TS_DATA_XFER) {
2470 				/*
2471 				 * connected, fill remote address too
2472 				 */
2473 				taa->REMADDR_length = sizeof (sin_t);
2474 				/* assumed 32-bit alignment */
2475 				taa->REMADDR_offset = taa->LOCADDR_offset +
2476 				    taa->LOCADDR_length;
2477 
2478 				sin = (sin_t *)(ackmp->b_rptr +
2479 				    taa->REMADDR_offset);
2480 				/* initialize */
2481 				*sin = sin_null;
2482 				sin->sin_family = AF_INET;
2483 				sin->sin_addr.s_addr =
2484 				    V4_PART_OF_V6(udp->udp_v6dst);
2485 				sin->sin_port = udp->udp_dstport;
2486 				ackmp->b_wptr = (uchar_t *)&sin[1];
2487 			}
2488 		} else {
2489 			taa->LOCADDR_length = sizeof (sin6_t);
2490 			sin6 = (sin6_t *)&taa[1];
2491 			/* Fill zeroes and then initialize non-zero fields */
2492 			*sin6 = sin6_null;
2493 			sin6->sin6_family = AF_INET6;
2494 			if (!IN6_IS_ADDR_UNSPECIFIED(&udp->udp_v6src)) {
2495 				sin6->sin6_addr = udp->udp_v6src;
2496 			} else {
2497 				/*
2498 				 * UNSPECIFIED
2499 				 * udp_v6src is not set, we might be bound to
2500 				 * broadcast/multicast. Use udp_bound_v6src as
2501 				 * local address instead (that could
2502 				 * also still be UNSPECIFIED)
2503 				 */
2504 				sin6->sin6_addr =
2505 				    udp->udp_bound_v6src;
2506 			}
2507 			sin6->sin6_port = udp->udp_port;
2508 			ackmp->b_wptr = (uchar_t *)&sin6[1];
2509 			if (udp->udp_state == TS_DATA_XFER) {
2510 				/*
2511 				 * connected, fill remote address too
2512 				 */
2513 				taa->REMADDR_length = sizeof (sin6_t);
2514 				/* assumed 32-bit alignment */
2515 				taa->REMADDR_offset = taa->LOCADDR_offset +
2516 				    taa->LOCADDR_length;
2517 
2518 				sin6 = (sin6_t *)(ackmp->b_rptr +
2519 				    taa->REMADDR_offset);
2520 				/* initialize */
2521 				*sin6 = sin6_null;
2522 				sin6->sin6_family = AF_INET6;
2523 				sin6->sin6_addr = udp->udp_v6dst;
2524 				sin6->sin6_port =  udp->udp_dstport;
2525 				ackmp->b_wptr = (uchar_t *)&sin6[1];
2526 			}
2527 			ackmp->b_wptr = (uchar_t *)&sin6[1];
2528 		}
2529 	}
2530 	ASSERT(ackmp->b_wptr <= ackmp->b_datap->db_lim);
2531 	putnext(UDP_RD(q), ackmp);
2532 }
2533 
2534 static void
2535 udp_copy_info(struct T_info_ack *tap, udp_t *udp)
2536 {
2537 	if (udp->udp_family == AF_INET) {
2538 		*tap = udp_g_t_info_ack_ipv4;
2539 	} else {
2540 		*tap = udp_g_t_info_ack_ipv6;
2541 	}
2542 	tap->CURRENT_state = udp->udp_state;
2543 	tap->OPT_size = udp_max_optsize;
2544 }
2545 
2546 /*
2547  * This routine responds to T_CAPABILITY_REQ messages.  It is called by
2548  * udp_wput.  Much of the T_CAPABILITY_ACK information is copied from
2549  * udp_g_t_info_ack.  The current state of the stream is copied from
2550  * udp_state.
2551  */
2552 static void
2553 udp_capability_req(queue_t *q, mblk_t *mp)
2554 {
2555 	t_uscalar_t		cap_bits1;
2556 	struct T_capability_ack	*tcap;
2557 	udp_t	*udp = Q_TO_UDP(q);
2558 
2559 	cap_bits1 = ((struct T_capability_req *)mp->b_rptr)->CAP_bits1;
2560 
2561 	mp = tpi_ack_alloc(mp, sizeof (struct T_capability_ack),
2562 	    mp->b_datap->db_type, T_CAPABILITY_ACK);
2563 	if (!mp)
2564 		return;
2565 
2566 	tcap = (struct T_capability_ack *)mp->b_rptr;
2567 	tcap->CAP_bits1 = 0;
2568 
2569 	if (cap_bits1 & TC1_INFO) {
2570 		udp_copy_info(&tcap->INFO_ack, udp);
2571 		tcap->CAP_bits1 |= TC1_INFO;
2572 	}
2573 
2574 	putnext(UDP_RD(q), mp);
2575 }
2576 
2577 /*
2578  * This routine responds to T_INFO_REQ messages.  It is called by udp_wput.
2579  * Most of the T_INFO_ACK information is copied from udp_g_t_info_ack.
2580  * The current state of the stream is copied from udp_state.
2581  */
2582 static void
2583 udp_info_req(queue_t *q, mblk_t *mp)
2584 {
2585 	udp_t *udp = Q_TO_UDP(q);
2586 
2587 	/* Create a T_INFO_ACK message. */
2588 	mp = tpi_ack_alloc(mp, sizeof (struct T_info_ack), M_PCPROTO,
2589 	    T_INFO_ACK);
2590 	if (!mp)
2591 		return;
2592 	udp_copy_info((struct T_info_ack *)mp->b_rptr, udp);
2593 	putnext(UDP_RD(q), mp);
2594 }
2595 
2596 /*
2597  * IP recognizes seven kinds of bind requests:
2598  *
2599  * - A zero-length address binds only to the protocol number.
2600  *
2601  * - A 4-byte address is treated as a request to
2602  * validate that the address is a valid local IPv4
2603  * address, appropriate for an application to bind to.
2604  * IP does the verification, but does not make any note
2605  * of the address at this time.
2606  *
2607  * - A 16-byte address contains is treated as a request
2608  * to validate a local IPv6 address, as the 4-byte
2609  * address case above.
2610  *
2611  * - A 16-byte sockaddr_in to validate the local IPv4 address and also
2612  * use it for the inbound fanout of packets.
2613  *
2614  * - A 24-byte sockaddr_in6 to validate the local IPv6 address and also
2615  * use it for the inbound fanout of packets.
2616  *
2617  * - A 12-byte address (ipa_conn_t) containing complete IPv4 fanout
2618  * information consisting of local and remote addresses
2619  * and ports.  In this case, the addresses are both
2620  * validated as appropriate for this operation, and, if
2621  * so, the information is retained for use in the
2622  * inbound fanout.
2623  *
2624  * - A 36-byte address address (ipa6_conn_t) containing complete IPv6
2625  * fanout information, like the 12-byte case above.
2626  *
2627  * IP will also fill in the IRE request mblk with information
2628  * regarding our peer.  In all cases, we notify IP of our protocol
2629  * type by appending a single protocol byte to the bind request.
2630  */
2631 static mblk_t *
2632 udp_ip_bind_mp(udp_t *udp, t_scalar_t bind_prim, t_scalar_t addr_length)
2633 {
2634 	char	*cp;
2635 	mblk_t	*mp;
2636 	struct T_bind_req *tbr;
2637 	ipa_conn_t	*ac;
2638 	ipa6_conn_t	*ac6;
2639 	sin_t		*sin;
2640 	sin6_t		*sin6;
2641 
2642 	ASSERT(bind_prim == O_T_BIND_REQ || bind_prim == T_BIND_REQ);
2643 
2644 	mp = allocb(sizeof (*tbr) + addr_length + 1, BPRI_HI);
2645 	if (!mp)
2646 		return (mp);
2647 	mp->b_datap->db_type = M_PROTO;
2648 	tbr = (struct T_bind_req *)mp->b_rptr;
2649 	tbr->PRIM_type = bind_prim;
2650 	tbr->ADDR_offset = sizeof (*tbr);
2651 	tbr->CONIND_number = 0;
2652 	tbr->ADDR_length = addr_length;
2653 	cp = (char *)&tbr[1];
2654 	switch (addr_length) {
2655 	case sizeof (ipa_conn_t):
2656 		ASSERT(udp->udp_family == AF_INET);
2657 		/* Append a request for an IRE */
2658 		mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
2659 		if (!mp->b_cont) {
2660 			freemsg(mp);
2661 			return (NULL);
2662 		}
2663 		mp->b_cont->b_wptr += sizeof (ire_t);
2664 		mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
2665 
2666 		/* cp known to be 32 bit aligned */
2667 		ac = (ipa_conn_t *)cp;
2668 		ac->ac_laddr = V4_PART_OF_V6(udp->udp_v6src);
2669 		ac->ac_faddr = V4_PART_OF_V6(udp->udp_v6dst);
2670 		ac->ac_fport = udp->udp_dstport;
2671 		ac->ac_lport = udp->udp_port;
2672 		break;
2673 
2674 	case sizeof (ipa6_conn_t):
2675 		ASSERT(udp->udp_family == AF_INET6);
2676 		/* Append a request for an IRE */
2677 		mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
2678 		if (!mp->b_cont) {
2679 			freemsg(mp);
2680 			return (NULL);
2681 		}
2682 		mp->b_cont->b_wptr += sizeof (ire_t);
2683 		mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
2684 
2685 		/* cp known to be 32 bit aligned */
2686 		ac6 = (ipa6_conn_t *)cp;
2687 		ac6->ac6_laddr = udp->udp_v6src;
2688 		ac6->ac6_faddr = udp->udp_v6dst;
2689 		ac6->ac6_fport = udp->udp_dstport;
2690 		ac6->ac6_lport = udp->udp_port;
2691 		break;
2692 
2693 	case sizeof (sin_t):
2694 		ASSERT(udp->udp_family == AF_INET);
2695 		/* Append a request for an IRE */
2696 		mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
2697 		if (!mp->b_cont) {
2698 			freemsg(mp);
2699 			return (NULL);
2700 		}
2701 		mp->b_cont->b_wptr += sizeof (ire_t);
2702 		mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
2703 
2704 		sin = (sin_t *)cp;
2705 		*sin = sin_null;
2706 		sin->sin_family = AF_INET;
2707 		sin->sin_addr.s_addr = V4_PART_OF_V6(udp->udp_bound_v6src);
2708 		sin->sin_port = udp->udp_port;
2709 		break;
2710 
2711 	case sizeof (sin6_t):
2712 		ASSERT(udp->udp_family == AF_INET6);
2713 		/* Append a request for an IRE */
2714 		mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
2715 		if (!mp->b_cont) {
2716 			freemsg(mp);
2717 			return (NULL);
2718 		}
2719 		mp->b_cont->b_wptr += sizeof (ire_t);
2720 		mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
2721 
2722 		sin6 = (sin6_t *)cp;
2723 		*sin6 = sin6_null;
2724 		sin6->sin6_family = AF_INET6;
2725 		sin6->sin6_addr = udp->udp_bound_v6src;
2726 		sin6->sin6_port = udp->udp_port;
2727 		break;
2728 	}
2729 	/* Add protocol number to end */
2730 	cp[addr_length] = (char)IPPROTO_UDP;
2731 	mp->b_wptr = (uchar_t *)&cp[addr_length + 1];
2732 	return (mp);
2733 }
2734 
2735 /*
2736  * This is the open routine for udp.  It allocates a udp_t structure for
2737  * the stream and, on the first open of the module, creates an ND table.
2738  */
2739 /* ARGSUSED */
2740 static int
2741 udp_open(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
2742 {
2743 	int	err;
2744 	udp_t	*udp;
2745 	conn_t *connp;
2746 	zoneid_t zoneid = getzoneid();
2747 	queue_t	*ip_wq;
2748 	char	*name;
2749 
2750 	TRACE_1(TR_FAC_UDP, TR_UDP_OPEN, "udp_open: q %p", q);
2751 
2752 	/* If the stream is already open, return immediately. */
2753 	if (q->q_ptr != NULL)
2754 		return (0);
2755 
2756 	/* If this is not a push of udp as a module, fail. */
2757 	if (sflag != MODOPEN)
2758 		return (EINVAL);
2759 
2760 	q->q_hiwat = udp_recv_hiwat;
2761 	WR(q)->q_hiwat = udp_xmit_hiwat;
2762 	WR(q)->q_lowat = udp_xmit_lowat;
2763 
2764 	/* Insert ourselves in the stream since we're about to walk q_next */
2765 	qprocson(q);
2766 
2767 	udp = kmem_cache_alloc(udp_cache, KM_SLEEP);
2768 	bzero(udp, sizeof (*udp));
2769 
2770 	/*
2771 	 * UDP is supported only as a module and it has to be pushed directly
2772 	 * above the device instance of IP. If UDP is pushed anywhere else
2773 	 * on a stream, it will support just T_SVR4_OPTMGMT_REQ for the
2774 	 * sake of MIB browsers and fail everything else.
2775 	 */
2776 	ip_wq = WR(q)->q_next;
2777 	if (ip_wq->q_next != NULL ||
2778 	    (name = ip_wq->q_qinfo->qi_minfo->mi_idname) == NULL ||
2779 	    strcmp(name, IP_MOD_NAME) != 0 ||
2780 	    ip_wq->q_qinfo->qi_minfo->mi_idnum != IP_MOD_ID) {
2781 		/* Support just SNMP for MIB browsers */
2782 		connp = ipcl_conn_create(IPCL_IPCCONN, KM_SLEEP);
2783 		connp->conn_rq = q;
2784 		connp->conn_wq = WR(q);
2785 		connp->conn_flags |= IPCL_UDPMOD;
2786 		connp->conn_cred = credp;
2787 		connp->conn_zoneid = zoneid;
2788 		connp->conn_udp = udp;
2789 		udp->udp_connp = connp;
2790 		q->q_ptr = WR(q)->q_ptr = connp;
2791 		crhold(credp);
2792 		q->q_qinfo = &udp_snmp_rinit;
2793 		WR(q)->q_qinfo = &udp_snmp_winit;
2794 		return (0);
2795 	}
2796 
2797 	/*
2798 	 * Initialize the udp_t structure for this stream.
2799 	 */
2800 	q = RD(ip_wq);
2801 	connp = Q_TO_CONN(q);
2802 	mutex_enter(&connp->conn_lock);
2803 	connp->conn_proto = IPPROTO_UDP;
2804 	connp->conn_flags |= IPCL_UDP;
2805 	connp->conn_sqp = IP_SQUEUE_GET(lbolt);
2806 	connp->conn_udp = udp;
2807 
2808 	/* Set the initial state of the stream and the privilege status. */
2809 	udp->udp_connp = connp;
2810 	udp->udp_state = TS_UNBND;
2811 	udp->udp_mode = UDP_MT_HOT;
2812 	if (getmajor(*devp) == (major_t)UDP6_MAJ) {
2813 		udp->udp_family = AF_INET6;
2814 		udp->udp_ipversion = IPV6_VERSION;
2815 		udp->udp_max_hdr_len = IPV6_HDR_LEN + UDPH_SIZE;
2816 		udp->udp_ttl = udp_ipv6_hoplimit;
2817 		connp->conn_af_isv6 = B_TRUE;
2818 		connp->conn_flags |= IPCL_ISV6;
2819 	} else {
2820 		udp->udp_family = AF_INET;
2821 		udp->udp_ipversion = IPV4_VERSION;
2822 		udp->udp_max_hdr_len = IP_SIMPLE_HDR_LENGTH + UDPH_SIZE;
2823 		udp->udp_ttl = udp_ipv4_ttl;
2824 		connp->conn_af_isv6 = B_FALSE;
2825 		connp->conn_flags &= ~IPCL_ISV6;
2826 	}
2827 
2828 	udp->udp_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
2829 	connp->conn_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
2830 	connp->conn_zoneid = zoneid;
2831 
2832 	if (connp->conn_flags & IPCL_SOCKET) {
2833 		udp->udp_issocket = B_TRUE;
2834 		udp->udp_direct_sockfs = B_TRUE;
2835 	}
2836 	mutex_exit(&connp->conn_lock);
2837 
2838 	/*
2839 	 * The transmit hiwat/lowat is only looked at on IP's queue.
2840 	 * Store in q_hiwat in order to return on SO_SNDBUF/SO_RCVBUF
2841 	 * getsockopts.
2842 	 */
2843 	q->q_hiwat = udp_recv_hiwat;
2844 	WR(q)->q_hiwat = udp_xmit_hiwat;
2845 	WR(q)->q_lowat = udp_xmit_lowat;
2846 
2847 	if (udp->udp_family == AF_INET6) {
2848 		/* Build initial header template for transmit */
2849 		if ((err = udp_build_hdrs(q, udp)) != 0) {
2850 			qprocsoff(UDP_RD(q));
2851 			udp->udp_connp = NULL;
2852 			connp->conn_udp = NULL;
2853 			kmem_cache_free(udp_cache, udp);
2854 			return (err);
2855 		}
2856 	}
2857 
2858 	/* Set the Stream head write offset and high watermark. */
2859 	(void) mi_set_sth_wroff(UDP_RD(q),
2860 	    udp->udp_max_hdr_len + udp_wroff_extra);
2861 	(void) mi_set_sth_hiwat(UDP_RD(q), udp_set_rcv_hiwat(udp, q->q_hiwat));
2862 
2863 	return (0);
2864 }
2865 
2866 /*
2867  * Which UDP options OK to set through T_UNITDATA_REQ...
2868  */
2869 /* ARGSUSED */
2870 static boolean_t
2871 udp_opt_allow_udr_set(t_scalar_t level, t_scalar_t name)
2872 {
2873 	return (B_TRUE);
2874 }
2875 
2876 /*
2877  * This routine gets default values of certain options whose default
2878  * values are maintained by protcol specific code
2879  */
2880 /* ARGSUSED */
2881 int
2882 udp_opt_default(queue_t	*q, t_scalar_t level, t_scalar_t name, uchar_t *ptr)
2883 {
2884 	int *i1 = (int *)ptr;
2885 
2886 	switch (level) {
2887 	case IPPROTO_IP:
2888 		switch (name) {
2889 		case IP_MULTICAST_TTL:
2890 			*ptr = (uchar_t)IP_DEFAULT_MULTICAST_TTL;
2891 			return (sizeof (uchar_t));
2892 		case IP_MULTICAST_LOOP:
2893 			*ptr = (uchar_t)IP_DEFAULT_MULTICAST_LOOP;
2894 			return (sizeof (uchar_t));
2895 		}
2896 		break;
2897 	case IPPROTO_IPV6:
2898 		switch (name) {
2899 		case IPV6_MULTICAST_HOPS:
2900 			*i1 = IP_DEFAULT_MULTICAST_TTL;
2901 			return (sizeof (int));
2902 		case IPV6_MULTICAST_LOOP:
2903 			*i1 = IP_DEFAULT_MULTICAST_LOOP;
2904 			return (sizeof (int));
2905 		case IPV6_UNICAST_HOPS:
2906 			*i1 = udp_ipv6_hoplimit;
2907 			return (sizeof (int));
2908 		}
2909 		break;
2910 	}
2911 	return (-1);
2912 }
2913 
2914 /*
2915  * This routine retrieves the current status of socket options
2916  * and expects the caller to pass in the queue pointer of the
2917  * upper instance.  It returns the size of the option retrieved.
2918  */
2919 int
2920 udp_opt_get(queue_t *q, t_scalar_t level, t_scalar_t name, uchar_t *ptr)
2921 {
2922 	int	*i1 = (int *)ptr;
2923 	conn_t	*connp;
2924 	udp_t	*udp;
2925 	ip6_pkt_t *ipp;
2926 
2927 	q = UDP_WR(q);
2928 	connp = Q_TO_CONN(q);
2929 	udp = connp->conn_udp;
2930 	ipp = &udp->udp_sticky_ipp;
2931 
2932 	switch (level) {
2933 	case SOL_SOCKET:
2934 		switch (name) {
2935 		case SO_DEBUG:
2936 			*i1 = udp->udp_debug;
2937 			break;	/* goto sizeof (int) option return */
2938 		case SO_REUSEADDR:
2939 			*i1 = udp->udp_reuseaddr;
2940 			break;	/* goto sizeof (int) option return */
2941 		case SO_TYPE:
2942 			*i1 = SOCK_DGRAM;
2943 			break;	/* goto sizeof (int) option return */
2944 
2945 		/*
2946 		 * The following three items are available here,
2947 		 * but are only meaningful to IP.
2948 		 */
2949 		case SO_DONTROUTE:
2950 			*i1 = udp->udp_dontroute;
2951 			break;	/* goto sizeof (int) option return */
2952 		case SO_USELOOPBACK:
2953 			*i1 = udp->udp_useloopback;
2954 			break;	/* goto sizeof (int) option return */
2955 		case SO_BROADCAST:
2956 			*i1 = udp->udp_broadcast;
2957 			break;	/* goto sizeof (int) option return */
2958 
2959 		case SO_SNDBUF:
2960 			*i1 = q->q_hiwat;
2961 			break;	/* goto sizeof (int) option return */
2962 		case SO_RCVBUF:
2963 			*i1 = RD(q)->q_hiwat;
2964 			break;	/* goto sizeof (int) option return */
2965 		case SO_DGRAM_ERRIND:
2966 			*i1 = udp->udp_dgram_errind;
2967 			break;	/* goto sizeof (int) option return */
2968 		case SO_RECVUCRED:
2969 			*i1 = udp->udp_recvucred;
2970 			break;	/* goto sizeof (int) option return */
2971 		default:
2972 			return (-1);
2973 		}
2974 		break;
2975 	case IPPROTO_IP:
2976 		if (udp->udp_family != AF_INET)
2977 			return (-1);
2978 		switch (name) {
2979 		case IP_OPTIONS:
2980 		case T_IP_OPTIONS:
2981 			if (udp->udp_ip_rcv_options_len)
2982 				bcopy(udp->udp_ip_rcv_options, ptr,
2983 				    udp->udp_ip_rcv_options_len);
2984 			return (udp->udp_ip_rcv_options_len);
2985 		case IP_TOS:
2986 		case T_IP_TOS:
2987 			*i1 = (int)udp->udp_type_of_service;
2988 			break;	/* goto sizeof (int) option return */
2989 		case IP_TTL:
2990 			*i1 = (int)udp->udp_ttl;
2991 			break;	/* goto sizeof (int) option return */
2992 		case IP_MULTICAST_IF:
2993 			/* 0 address if not set */
2994 			*(ipaddr_t *)ptr = udp->udp_multicast_if_addr;
2995 			return (sizeof (ipaddr_t));
2996 		case IP_MULTICAST_TTL:
2997 			*(uchar_t *)ptr = udp->udp_multicast_ttl;
2998 			return (sizeof (uchar_t));
2999 		case IP_MULTICAST_LOOP:
3000 			*ptr = connp->conn_multicast_loop;
3001 			return (sizeof (uint8_t));
3002 		case IP_RECVOPTS:
3003 			*i1 = udp->udp_recvopts;
3004 			break;	/* goto sizeof (int) option return */
3005 		case IP_RECVDSTADDR:
3006 			*i1 = udp->udp_recvdstaddr;
3007 			break;	/* goto sizeof (int) option return */
3008 		case IP_RECVIF:
3009 			*i1 = udp->udp_recvif;
3010 			break;	/* goto sizeof (int) option return */
3011 		case IP_RECVSLLA:
3012 			*i1 = udp->udp_recvslla;
3013 			break;	/* goto sizeof (int) option return */
3014 		case IP_RECVTTL:
3015 			*i1 = udp->udp_recvttl;
3016 			break;	/* goto sizeof (int) option return */
3017 		case IP_ADD_MEMBERSHIP:
3018 		case IP_DROP_MEMBERSHIP:
3019 		case IP_BLOCK_SOURCE:
3020 		case IP_UNBLOCK_SOURCE:
3021 		case IP_ADD_SOURCE_MEMBERSHIP:
3022 		case IP_DROP_SOURCE_MEMBERSHIP:
3023 		case MCAST_JOIN_GROUP:
3024 		case MCAST_LEAVE_GROUP:
3025 		case MCAST_BLOCK_SOURCE:
3026 		case MCAST_UNBLOCK_SOURCE:
3027 		case MCAST_JOIN_SOURCE_GROUP:
3028 		case MCAST_LEAVE_SOURCE_GROUP:
3029 		case IP_DONTFAILOVER_IF:
3030 			/* cannot "get" the value for these */
3031 			return (-1);
3032 		case IP_BOUND_IF:
3033 			/* Zero if not set */
3034 			*i1 = udp->udp_bound_if;
3035 			break;	/* goto sizeof (int) option return */
3036 		case IP_UNSPEC_SRC:
3037 			*i1 = udp->udp_unspec_source;
3038 			break;	/* goto sizeof (int) option return */
3039 		case IP_XMIT_IF:
3040 			*i1 = udp->udp_xmit_if;
3041 			break; /* goto sizeof (int) option return */
3042 		default:
3043 			return (-1);
3044 		}
3045 		break;
3046 	case IPPROTO_IPV6:
3047 		if (udp->udp_family != AF_INET6)
3048 			return (-1);
3049 		switch (name) {
3050 		case IPV6_UNICAST_HOPS:
3051 			*i1 = (unsigned int)udp->udp_ttl;
3052 			break;	/* goto sizeof (int) option return */
3053 		case IPV6_MULTICAST_IF:
3054 			/* 0 index if not set */
3055 			*i1 = udp->udp_multicast_if_index;
3056 			break;	/* goto sizeof (int) option return */
3057 		case IPV6_MULTICAST_HOPS:
3058 			*i1 = udp->udp_multicast_ttl;
3059 			break;	/* goto sizeof (int) option return */
3060 		case IPV6_MULTICAST_LOOP:
3061 			*i1 = connp->conn_multicast_loop;
3062 			break;	/* goto sizeof (int) option return */
3063 		case IPV6_JOIN_GROUP:
3064 		case IPV6_LEAVE_GROUP:
3065 		case MCAST_JOIN_GROUP:
3066 		case MCAST_LEAVE_GROUP:
3067 		case MCAST_BLOCK_SOURCE:
3068 		case MCAST_UNBLOCK_SOURCE:
3069 		case MCAST_JOIN_SOURCE_GROUP:
3070 		case MCAST_LEAVE_SOURCE_GROUP:
3071 			/* cannot "get" the value for these */
3072 			return (-1);
3073 		case IPV6_BOUND_IF:
3074 			/* Zero if not set */
3075 			*i1 = udp->udp_bound_if;
3076 			break;	/* goto sizeof (int) option return */
3077 		case IPV6_UNSPEC_SRC:
3078 			*i1 = udp->udp_unspec_source;
3079 			break;	/* goto sizeof (int) option return */
3080 		case IPV6_RECVPKTINFO:
3081 			*i1 = udp->udp_ipv6_recvpktinfo;
3082 			break;	/* goto sizeof (int) option return */
3083 		case IPV6_RECVTCLASS:
3084 			*i1 = udp->udp_ipv6_recvtclass;
3085 			break;	/* goto sizeof (int) option return */
3086 		case IPV6_RECVPATHMTU:
3087 			*i1 = udp->udp_ipv6_recvpathmtu;
3088 			break;	/* goto sizeof (int) option return */
3089 		case IPV6_RECVHOPLIMIT:
3090 			*i1 = udp->udp_ipv6_recvhoplimit;
3091 			break;	/* goto sizeof (int) option return */
3092 		case IPV6_RECVHOPOPTS:
3093 			*i1 = udp->udp_ipv6_recvhopopts;
3094 			break;	/* goto sizeof (int) option return */
3095 		case IPV6_RECVDSTOPTS:
3096 			*i1 = udp->udp_ipv6_recvdstopts;
3097 			break;	/* goto sizeof (int) option return */
3098 		case _OLD_IPV6_RECVDSTOPTS:
3099 			*i1 = udp->udp_old_ipv6_recvdstopts;
3100 			break;	/* goto sizeof (int) option return */
3101 		case IPV6_RECVRTHDRDSTOPTS:
3102 			*i1 = udp->udp_ipv6_recvrthdrdstopts;
3103 			break;	/* goto sizeof (int) option return */
3104 		case IPV6_RECVRTHDR:
3105 			*i1 = udp->udp_ipv6_recvrthdr;
3106 			break;	/* goto sizeof (int) option return */
3107 		case IPV6_PKTINFO: {
3108 			/* XXX assumes that caller has room for max size! */
3109 			struct in6_pktinfo *pkti;
3110 
3111 			pkti = (struct in6_pktinfo *)ptr;
3112 			if (ipp->ipp_fields & IPPF_IFINDEX)
3113 				pkti->ipi6_ifindex = ipp->ipp_ifindex;
3114 			else
3115 				pkti->ipi6_ifindex = 0;
3116 			if (ipp->ipp_fields & IPPF_ADDR)
3117 				pkti->ipi6_addr = ipp->ipp_addr;
3118 			else
3119 				pkti->ipi6_addr = ipv6_all_zeros;
3120 			return (sizeof (struct in6_pktinfo));
3121 		}
3122 		case IPV6_TCLASS:
3123 			if (ipp->ipp_fields & IPPF_TCLASS)
3124 				*i1 = ipp->ipp_tclass;
3125 			else
3126 				*i1 = IPV6_FLOW_TCLASS(
3127 				    IPV6_DEFAULT_VERS_AND_FLOW);
3128 			break;	/* goto sizeof (int) option return */
3129 		case IPV6_NEXTHOP: {
3130 			sin6_t *sin6 = (sin6_t *)ptr;
3131 
3132 			if (!(ipp->ipp_fields & IPPF_NEXTHOP))
3133 				return (0);
3134 			*sin6 = sin6_null;
3135 			sin6->sin6_family = AF_INET6;
3136 			sin6->sin6_addr = ipp->ipp_nexthop;
3137 			return (sizeof (sin6_t));
3138 		}
3139 		case IPV6_HOPOPTS:
3140 			if (!(ipp->ipp_fields & IPPF_HOPOPTS))
3141 				return (0);
3142 			bcopy(ipp->ipp_hopopts, ptr, ipp->ipp_hopoptslen);
3143 			return (ipp->ipp_hopoptslen);
3144 		case IPV6_RTHDRDSTOPTS:
3145 			if (!(ipp->ipp_fields & IPPF_RTDSTOPTS))
3146 				return (0);
3147 			bcopy(ipp->ipp_rtdstopts, ptr, ipp->ipp_rtdstoptslen);
3148 			return (ipp->ipp_rtdstoptslen);
3149 		case IPV6_RTHDR:
3150 			if (!(ipp->ipp_fields & IPPF_RTHDR))
3151 				return (0);
3152 			bcopy(ipp->ipp_rthdr, ptr, ipp->ipp_rthdrlen);
3153 			return (ipp->ipp_rthdrlen);
3154 		case IPV6_DSTOPTS:
3155 			if (!(ipp->ipp_fields & IPPF_DSTOPTS))
3156 				return (0);
3157 			bcopy(ipp->ipp_dstopts, ptr, ipp->ipp_dstoptslen);
3158 			return (ipp->ipp_dstoptslen);
3159 		case IPV6_PATHMTU:
3160 			return (ip_fill_mtuinfo(&udp->udp_v6dst,
3161 				udp->udp_dstport, (struct ip6_mtuinfo *)ptr));
3162 		default:
3163 			return (-1);
3164 		}
3165 		break;
3166 	case IPPROTO_UDP:
3167 		switch (name) {
3168 		case UDP_ANONPRIVBIND:
3169 			*i1 = udp->udp_anon_priv_bind;
3170 			break;
3171 		case UDP_EXCLBIND:
3172 			*i1 = udp->udp_exclbind ? UDP_EXCLBIND : 0;
3173 			break;
3174 		case UDP_RCVHDR:
3175 			*i1 = udp->udp_rcvhdr ? 1 : 0;
3176 			break;
3177 		default:
3178 			return (-1);
3179 		}
3180 		break;
3181 	default:
3182 		return (-1);
3183 	}
3184 	return (sizeof (int));
3185 }
3186 
3187 /*
3188  * This routine sets socket options; it expects the caller
3189  * to pass in the queue pointer of the upper instance.
3190  */
3191 /* ARGSUSED */
3192 int
3193 udp_opt_set(queue_t *q, uint_t optset_context, int level,
3194     int name, uint_t inlen, uchar_t *invalp, uint_t *outlenp,
3195     uchar_t *outvalp, void *thisdg_attrs, cred_t *cr, mblk_t *mblk)
3196 {
3197 	int	*i1 = (int *)invalp;
3198 	boolean_t onoff = (*i1 == 0) ? 0 : 1;
3199 	boolean_t checkonly;
3200 	int	error;
3201 	conn_t	*connp;
3202 	udp_t	*udp;
3203 
3204 	q = UDP_WR(q);
3205 	connp = Q_TO_CONN(q);
3206 	udp = connp->conn_udp;
3207 
3208 	switch (optset_context) {
3209 	case SETFN_OPTCOM_CHECKONLY:
3210 		checkonly = B_TRUE;
3211 		/*
3212 		 * Note: Implies T_CHECK semantics for T_OPTCOM_REQ
3213 		 * inlen != 0 implies value supplied and
3214 		 * 	we have to "pretend" to set it.
3215 		 * inlen == 0 implies that there is no
3216 		 * 	value part in T_CHECK request and just validation
3217 		 * done elsewhere should be enough, we just return here.
3218 		 */
3219 		if (inlen == 0) {
3220 			*outlenp = 0;
3221 			return (0);
3222 		}
3223 		break;
3224 	case SETFN_OPTCOM_NEGOTIATE:
3225 		checkonly = B_FALSE;
3226 		break;
3227 	case SETFN_UD_NEGOTIATE:
3228 	case SETFN_CONN_NEGOTIATE:
3229 		checkonly = B_FALSE;
3230 		/*
3231 		 * Negotiating local and "association-related" options
3232 		 * through T_UNITDATA_REQ.
3233 		 *
3234 		 * Following routine can filter out ones we do not
3235 		 * want to be "set" this way.
3236 		 */
3237 		if (!udp_opt_allow_udr_set(level, name)) {
3238 			*outlenp = 0;
3239 			return (EINVAL);
3240 		}
3241 		break;
3242 	default:
3243 		/*
3244 		 * We should never get here
3245 		 */
3246 		*outlenp = 0;
3247 		return (EINVAL);
3248 	}
3249 
3250 	ASSERT((optset_context != SETFN_OPTCOM_CHECKONLY) ||
3251 	    (optset_context == SETFN_OPTCOM_CHECKONLY && inlen != 0));
3252 
3253 	/*
3254 	 * For fixed length options, no sanity check
3255 	 * of passed in length is done. It is assumed *_optcom_req()
3256 	 * routines do the right thing.
3257 	 */
3258 
3259 	switch (level) {
3260 	case SOL_SOCKET:
3261 		switch (name) {
3262 		case SO_REUSEADDR:
3263 			if (!checkonly)
3264 				udp->udp_reuseaddr = onoff;
3265 			break;
3266 		case SO_DEBUG:
3267 			if (!checkonly)
3268 				udp->udp_debug = onoff;
3269 			break;
3270 		/*
3271 		 * The following three items are available here,
3272 		 * but are only meaningful to IP.
3273 		 */
3274 		case SO_DONTROUTE:
3275 			if (!checkonly)
3276 				udp->udp_dontroute = onoff;
3277 			break;
3278 		case SO_USELOOPBACK:
3279 			if (!checkonly)
3280 				udp->udp_useloopback = onoff;
3281 			break;
3282 		case SO_BROADCAST:
3283 			if (!checkonly)
3284 				udp->udp_broadcast = onoff;
3285 			break;
3286 
3287 		case SO_SNDBUF:
3288 			if (*i1 > udp_max_buf) {
3289 				*outlenp = 0;
3290 				return (ENOBUFS);
3291 			}
3292 			if (!checkonly) {
3293 				q->q_hiwat = *i1;
3294 				WR(UDP_RD(q))->q_hiwat = *i1;
3295 			}
3296 			break;
3297 		case SO_RCVBUF:
3298 			if (*i1 > udp_max_buf) {
3299 				*outlenp = 0;
3300 				return (ENOBUFS);
3301 			}
3302 			if (!checkonly) {
3303 				RD(q)->q_hiwat = *i1;
3304 				UDP_RD(q)->q_hiwat = *i1;
3305 				(void) mi_set_sth_hiwat(UDP_RD(q),
3306 				    udp_set_rcv_hiwat(udp, *i1));
3307 			}
3308 			break;
3309 		case SO_DGRAM_ERRIND:
3310 			if (!checkonly)
3311 				udp->udp_dgram_errind = onoff;
3312 			break;
3313 		case SO_RECVUCRED:
3314 			if (!checkonly)
3315 				udp->udp_recvucred = onoff;
3316 			break;
3317 		default:
3318 			*outlenp = 0;
3319 			return (EINVAL);
3320 		}
3321 		break;
3322 	case IPPROTO_IP:
3323 		if (udp->udp_family != AF_INET) {
3324 			*outlenp = 0;
3325 			return (ENOPROTOOPT);
3326 		}
3327 		switch (name) {
3328 		case IP_OPTIONS:
3329 		case T_IP_OPTIONS:
3330 			/* Save options for use by IP. */
3331 			if (inlen & 0x3) {
3332 				*outlenp = 0;
3333 				return (EINVAL);
3334 			}
3335 			if (checkonly)
3336 				break;
3337 
3338 			if (udp->udp_ip_snd_options) {
3339 				mi_free((char *)udp->udp_ip_snd_options);
3340 				udp->udp_ip_snd_options_len = 0;
3341 				udp->udp_ip_snd_options = NULL;
3342 			}
3343 			if (inlen) {
3344 				udp->udp_ip_snd_options =
3345 					(uchar_t *)mi_alloc(inlen, BPRI_HI);
3346 				if (udp->udp_ip_snd_options) {
3347 					bcopy(invalp, udp->udp_ip_snd_options,
3348 					    inlen);
3349 					udp->udp_ip_snd_options_len = inlen;
3350 				}
3351 			}
3352 			udp->udp_max_hdr_len = IP_SIMPLE_HDR_LENGTH +
3353 			    UDPH_SIZE + udp->udp_ip_snd_options_len;
3354 			(void) mi_set_sth_wroff(RD(q), udp->udp_max_hdr_len +
3355 			    udp_wroff_extra);
3356 			break;
3357 		case IP_TTL:
3358 			if (!checkonly) {
3359 				udp->udp_ttl = (uchar_t)*i1;
3360 			}
3361 			break;
3362 		case IP_TOS:
3363 		case T_IP_TOS:
3364 			if (!checkonly) {
3365 				udp->udp_type_of_service = (uchar_t)*i1;
3366 			}
3367 			break;
3368 		case IP_MULTICAST_IF: {
3369 			/*
3370 			 * TODO should check OPTMGMT reply and undo this if
3371 			 * there is an error.
3372 			 */
3373 			struct in_addr *inap = (struct in_addr *)invalp;
3374 			if (!checkonly) {
3375 				udp->udp_multicast_if_addr =
3376 				    inap->s_addr;
3377 			}
3378 			break;
3379 		}
3380 		case IP_MULTICAST_TTL:
3381 			if (!checkonly)
3382 				udp->udp_multicast_ttl = *invalp;
3383 			break;
3384 		case IP_MULTICAST_LOOP:
3385 			if (!checkonly)
3386 				connp->conn_multicast_loop = *invalp;
3387 			break;
3388 		case IP_RECVOPTS:
3389 			if (!checkonly)
3390 				udp->udp_recvopts = onoff;
3391 			break;
3392 		case IP_RECVDSTADDR:
3393 			if (!checkonly)
3394 				udp->udp_recvdstaddr = onoff;
3395 			break;
3396 		case IP_RECVIF:
3397 			if (!checkonly)
3398 				udp->udp_recvif = onoff;
3399 			break;
3400 		case IP_RECVSLLA:
3401 			if (!checkonly)
3402 				udp->udp_recvslla = onoff;
3403 			break;
3404 		case IP_RECVTTL:
3405 			if (!checkonly)
3406 				udp->udp_recvttl = onoff;
3407 			break;
3408 		case IP_ADD_MEMBERSHIP:
3409 		case IP_DROP_MEMBERSHIP:
3410 		case IP_BLOCK_SOURCE:
3411 		case IP_UNBLOCK_SOURCE:
3412 		case IP_ADD_SOURCE_MEMBERSHIP:
3413 		case IP_DROP_SOURCE_MEMBERSHIP:
3414 		case MCAST_JOIN_GROUP:
3415 		case MCAST_LEAVE_GROUP:
3416 		case MCAST_BLOCK_SOURCE:
3417 		case MCAST_UNBLOCK_SOURCE:
3418 		case MCAST_JOIN_SOURCE_GROUP:
3419 		case MCAST_LEAVE_SOURCE_GROUP:
3420 		case IP_SEC_OPT:
3421 			/*
3422 			 * "soft" error (negative)
3423 			 * option not handled at this level
3424 			 * Do not modify *outlenp.
3425 			 */
3426 			return (-EINVAL);
3427 		case IP_BOUND_IF:
3428 			if (!checkonly)
3429 				udp->udp_bound_if = *i1;
3430 			break;
3431 		case IP_UNSPEC_SRC:
3432 			if (!checkonly)
3433 				udp->udp_unspec_source = onoff;
3434 			break;
3435 		case IP_XMIT_IF:
3436 			if (!checkonly)
3437 				udp->udp_xmit_if = *i1;
3438 			break;
3439 		default:
3440 			*outlenp = 0;
3441 			return (EINVAL);
3442 		}
3443 		break;
3444 	case IPPROTO_IPV6: {
3445 		ip6_pkt_t		*ipp;
3446 		boolean_t		sticky;
3447 
3448 		if (udp->udp_family != AF_INET6) {
3449 			*outlenp = 0;
3450 			return (ENOPROTOOPT);
3451 		}
3452 		/*
3453 		 * Deal with both sticky options and ancillary data
3454 		 */
3455 		if (thisdg_attrs == NULL) {
3456 			/* sticky options, or none */
3457 			ipp = &udp->udp_sticky_ipp;
3458 			sticky = B_TRUE;
3459 		} else {
3460 			/* ancillary data */
3461 			ipp = (ip6_pkt_t *)thisdg_attrs;
3462 			sticky = B_FALSE;
3463 		}
3464 
3465 		switch (name) {
3466 		case IPV6_MULTICAST_IF:
3467 			if (!checkonly)
3468 				udp->udp_multicast_if_index = *i1;
3469 			break;
3470 		case IPV6_UNICAST_HOPS:
3471 			/* -1 means use default */
3472 			if (*i1 < -1 || *i1 > IPV6_MAX_HOPS) {
3473 				*outlenp = 0;
3474 				return (EINVAL);
3475 			}
3476 			if (!checkonly) {
3477 				if (*i1 == -1) {
3478 					udp->udp_ttl = ipp->ipp_unicast_hops =
3479 					    udp_ipv6_hoplimit;
3480 					ipp->ipp_fields &= ~IPPF_UNICAST_HOPS;
3481 					/* Pass modified value to IP. */
3482 					*i1 = udp->udp_ttl;
3483 				} else {
3484 					udp->udp_ttl = ipp->ipp_unicast_hops =
3485 					    (uint8_t)*i1;
3486 					ipp->ipp_fields |= IPPF_UNICAST_HOPS;
3487 				}
3488 				/* Rebuild the header template */
3489 				error = udp_build_hdrs(q, udp);
3490 				if (error != 0) {
3491 					*outlenp = 0;
3492 					return (error);
3493 				}
3494 			}
3495 			break;
3496 		case IPV6_MULTICAST_HOPS:
3497 			/* -1 means use default */
3498 			if (*i1 < -1 || *i1 > IPV6_MAX_HOPS) {
3499 				*outlenp = 0;
3500 				return (EINVAL);
3501 			}
3502 			if (!checkonly) {
3503 				if (*i1 == -1) {
3504 					udp->udp_multicast_ttl =
3505 					    ipp->ipp_multicast_hops =
3506 					    IP_DEFAULT_MULTICAST_TTL;
3507 					ipp->ipp_fields &= ~IPPF_MULTICAST_HOPS;
3508 					/* Pass modified value to IP. */
3509 					*i1 = udp->udp_multicast_ttl;
3510 				} else {
3511 					udp->udp_multicast_ttl =
3512 					    ipp->ipp_multicast_hops =
3513 					    (uint8_t)*i1;
3514 					ipp->ipp_fields |= IPPF_MULTICAST_HOPS;
3515 				}
3516 			}
3517 			break;
3518 		case IPV6_MULTICAST_LOOP:
3519 			if (*i1 != 0 && *i1 != 1) {
3520 				*outlenp = 0;
3521 				return (EINVAL);
3522 			}
3523 			if (!checkonly)
3524 				connp->conn_multicast_loop = *i1;
3525 			break;
3526 		case IPV6_JOIN_GROUP:
3527 		case IPV6_LEAVE_GROUP:
3528 		case MCAST_JOIN_GROUP:
3529 		case MCAST_LEAVE_GROUP:
3530 		case MCAST_BLOCK_SOURCE:
3531 		case MCAST_UNBLOCK_SOURCE:
3532 		case MCAST_JOIN_SOURCE_GROUP:
3533 		case MCAST_LEAVE_SOURCE_GROUP:
3534 			/*
3535 			 * "soft" error (negative)
3536 			 * option not handled at this level
3537 			 * Note: Do not modify *outlenp
3538 			 */
3539 			return (-EINVAL);
3540 		case IPV6_BOUND_IF:
3541 			if (!checkonly)
3542 				udp->udp_bound_if = *i1;
3543 			break;
3544 		case IPV6_UNSPEC_SRC:
3545 			if (!checkonly)
3546 				udp->udp_unspec_source = onoff;
3547 			break;
3548 		/*
3549 		 * Set boolean switches for ancillary data delivery
3550 		 */
3551 		case IPV6_RECVPKTINFO:
3552 			if (!checkonly)
3553 				udp->udp_ipv6_recvpktinfo = onoff;
3554 			break;
3555 		case IPV6_RECVTCLASS:
3556 			if (!checkonly) {
3557 				udp->udp_ipv6_recvtclass = onoff;
3558 			}
3559 			break;
3560 		case IPV6_RECVPATHMTU:
3561 			if (!checkonly) {
3562 				udp->udp_ipv6_recvpathmtu = onoff;
3563 			}
3564 			break;
3565 		case IPV6_RECVHOPLIMIT:
3566 			if (!checkonly)
3567 				udp->udp_ipv6_recvhoplimit = onoff;
3568 			break;
3569 		case IPV6_RECVHOPOPTS:
3570 			if (!checkonly)
3571 				udp->udp_ipv6_recvhopopts = onoff;
3572 			break;
3573 		case IPV6_RECVDSTOPTS:
3574 			if (!checkonly)
3575 				udp->udp_ipv6_recvdstopts = onoff;
3576 			break;
3577 		case _OLD_IPV6_RECVDSTOPTS:
3578 			if (!checkonly)
3579 				udp->udp_old_ipv6_recvdstopts = onoff;
3580 			break;
3581 		case IPV6_RECVRTHDRDSTOPTS:
3582 			if (!checkonly)
3583 				udp->udp_ipv6_recvrthdrdstopts = onoff;
3584 			break;
3585 		case IPV6_RECVRTHDR:
3586 			if (!checkonly)
3587 				udp->udp_ipv6_recvrthdr = onoff;
3588 			break;
3589 		/*
3590 		 * Set sticky options or ancillary data.
3591 		 * If sticky options, (re)build any extension headers
3592 		 * that might be needed as a result.
3593 		 */
3594 		case IPV6_PKTINFO:
3595 			/*
3596 			 * The source address and ifindex are verified
3597 			 * in ip_opt_set(). For ancillary data the
3598 			 * source address is checked in ip_wput_v6.
3599 			 */
3600 			if (inlen != 0 && inlen != sizeof (struct in6_pktinfo))
3601 				return (EINVAL);
3602 			if (checkonly)
3603 				break;
3604 
3605 			if (inlen == 0) {
3606 				ipp->ipp_fields &= ~(IPPF_IFINDEX|IPPF_ADDR);
3607 				ipp->ipp_sticky_ignored |=
3608 				    (IPPF_IFINDEX|IPPF_ADDR);
3609 			} else {
3610 				struct in6_pktinfo *pkti;
3611 
3612 				pkti = (struct in6_pktinfo *)invalp;
3613 				ipp->ipp_ifindex = pkti->ipi6_ifindex;
3614 				ipp->ipp_addr = pkti->ipi6_addr;
3615 				if (ipp->ipp_ifindex != 0)
3616 					ipp->ipp_fields |= IPPF_IFINDEX;
3617 				else
3618 					ipp->ipp_fields &= ~IPPF_IFINDEX;
3619 				if (!IN6_IS_ADDR_UNSPECIFIED(
3620 				    &ipp->ipp_addr))
3621 					ipp->ipp_fields |= IPPF_ADDR;
3622 				else
3623 					ipp->ipp_fields &= ~IPPF_ADDR;
3624 			}
3625 			if (sticky) {
3626 				error = udp_build_hdrs(q, udp);
3627 				if (error != 0)
3628 					return (error);
3629 			}
3630 			break;
3631 		case IPV6_HOPLIMIT:
3632 			if (sticky)
3633 				return (EINVAL);
3634 			if (inlen != 0 && inlen != sizeof (int))
3635 				return (EINVAL);
3636 			if (checkonly)
3637 				break;
3638 
3639 			if (inlen == 0) {
3640 				ipp->ipp_fields &= ~IPPF_HOPLIMIT;
3641 				ipp->ipp_sticky_ignored |= IPPF_HOPLIMIT;
3642 			} else {
3643 				if (*i1 > 255 || *i1 < -1)
3644 					return (EINVAL);
3645 				if (*i1 == -1)
3646 					ipp->ipp_hoplimit = udp_ipv6_hoplimit;
3647 				else
3648 					ipp->ipp_hoplimit = *i1;
3649 				ipp->ipp_fields |= IPPF_HOPLIMIT;
3650 			}
3651 			break;
3652 		case IPV6_TCLASS:
3653 			if (inlen != 0 && inlen != sizeof (int))
3654 				return (EINVAL);
3655 			if (checkonly)
3656 				break;
3657 
3658 			if (inlen == 0) {
3659 				ipp->ipp_fields &= ~IPPF_TCLASS;
3660 				ipp->ipp_sticky_ignored |= IPPF_TCLASS;
3661 			} else {
3662 				if (*i1 > 255 || *i1 < -1)
3663 					return (EINVAL);
3664 				if (*i1 == -1)
3665 					ipp->ipp_tclass = 0;
3666 				else
3667 					ipp->ipp_tclass = *i1;
3668 				ipp->ipp_fields |= IPPF_TCLASS;
3669 			}
3670 			if (sticky) {
3671 				error = udp_build_hdrs(q, udp);
3672 				if (error != 0)
3673 					return (error);
3674 			}
3675 			break;
3676 		case IPV6_NEXTHOP:
3677 			/*
3678 			 * IP will verify that the nexthop is reachable
3679 			 * and fail for sticky options.
3680 			 */
3681 			if (inlen != 0 && inlen != sizeof (sin6_t))
3682 				return (EINVAL);
3683 			if (checkonly)
3684 				break;
3685 
3686 			if (inlen == 0) {
3687 				ipp->ipp_fields &= ~IPPF_NEXTHOP;
3688 				ipp->ipp_sticky_ignored |= IPPF_NEXTHOP;
3689 			} else {
3690 				sin6_t *sin6 = (sin6_t *)invalp;
3691 
3692 				if (sin6->sin6_family != AF_INET6)
3693 					return (EAFNOSUPPORT);
3694 				if (IN6_IS_ADDR_V4MAPPED(
3695 				    &sin6->sin6_addr))
3696 					return (EADDRNOTAVAIL);
3697 				ipp->ipp_nexthop = sin6->sin6_addr;
3698 				if (!IN6_IS_ADDR_UNSPECIFIED(
3699 				    &ipp->ipp_nexthop))
3700 					ipp->ipp_fields |= IPPF_NEXTHOP;
3701 				else
3702 					ipp->ipp_fields &= ~IPPF_NEXTHOP;
3703 			}
3704 			if (sticky) {
3705 				error = udp_build_hdrs(q, udp);
3706 				if (error != 0)
3707 					return (error);
3708 			}
3709 			break;
3710 		case IPV6_HOPOPTS: {
3711 			ip6_hbh_t *hopts = (ip6_hbh_t *)invalp;
3712 			/*
3713 			 * Sanity checks - minimum size, size a multiple of
3714 			 * eight bytes, and matching size passed in.
3715 			 */
3716 			if (inlen != 0 &&
3717 			    inlen != (8 * (hopts->ip6h_len + 1)))
3718 				return (EINVAL);
3719 
3720 			if (checkonly)
3721 				break;
3722 
3723 			if (inlen == 0) {
3724 				if (sticky &&
3725 				    (ipp->ipp_fields & IPPF_HOPOPTS) != 0) {
3726 					kmem_free(ipp->ipp_hopopts,
3727 					    ipp->ipp_hopoptslen);
3728 					ipp->ipp_hopopts = NULL;
3729 					ipp->ipp_hopoptslen = 0;
3730 				}
3731 				ipp->ipp_fields &= ~IPPF_HOPOPTS;
3732 				ipp->ipp_sticky_ignored |= IPPF_HOPOPTS;
3733 			} else {
3734 				error = udp_pkt_set(invalp, inlen, sticky,
3735 				    (uchar_t **)&ipp->ipp_hopopts,
3736 				    &ipp->ipp_hopoptslen);
3737 				if (error != 0)
3738 					return (error);
3739 				ipp->ipp_fields |= IPPF_HOPOPTS;
3740 			}
3741 			if (sticky) {
3742 				error = udp_build_hdrs(q, udp);
3743 				if (error != 0)
3744 					return (error);
3745 			}
3746 			break;
3747 		}
3748 		case IPV6_RTHDRDSTOPTS: {
3749 			ip6_dest_t *dopts = (ip6_dest_t *)invalp;
3750 
3751 			/*
3752 			 * Sanity checks - minimum size, size a multiple of
3753 			 * eight bytes, and matching size passed in.
3754 			 */
3755 			if (inlen != 0 &&
3756 			    inlen != (8 * (dopts->ip6d_len + 1)))
3757 				return (EINVAL);
3758 
3759 			if (checkonly)
3760 				break;
3761 
3762 			if (inlen == 0) {
3763 				if (sticky &&
3764 				    (ipp->ipp_fields & IPPF_RTDSTOPTS) != 0) {
3765 					kmem_free(ipp->ipp_rtdstopts,
3766 					    ipp->ipp_rtdstoptslen);
3767 					ipp->ipp_rtdstopts = NULL;
3768 					ipp->ipp_rtdstoptslen = 0;
3769 				}
3770 
3771 				ipp->ipp_fields &= ~IPPF_RTDSTOPTS;
3772 				ipp->ipp_sticky_ignored |= IPPF_RTDSTOPTS;
3773 			} else {
3774 				error = udp_pkt_set(invalp, inlen, sticky,
3775 				    (uchar_t **)&ipp->ipp_rtdstopts,
3776 				    &ipp->ipp_rtdstoptslen);
3777 				if (error != 0)
3778 					return (error);
3779 				ipp->ipp_fields |= IPPF_RTDSTOPTS;
3780 			}
3781 			if (sticky) {
3782 				error = udp_build_hdrs(q, udp);
3783 				if (error != 0)
3784 					return (error);
3785 			}
3786 			break;
3787 		}
3788 		case IPV6_DSTOPTS: {
3789 			ip6_dest_t *dopts = (ip6_dest_t *)invalp;
3790 
3791 			/*
3792 			 * Sanity checks - minimum size, size a multiple of
3793 			 * eight bytes, and matching size passed in.
3794 			 */
3795 			if (inlen != 0 &&
3796 			    inlen != (8 * (dopts->ip6d_len + 1)))
3797 				return (EINVAL);
3798 
3799 			if (checkonly)
3800 				break;
3801 
3802 			if (inlen == 0) {
3803 				if (sticky &&
3804 				    (ipp->ipp_fields & IPPF_DSTOPTS) != 0) {
3805 					kmem_free(ipp->ipp_dstopts,
3806 					    ipp->ipp_dstoptslen);
3807 					ipp->ipp_dstopts = NULL;
3808 					ipp->ipp_dstoptslen = 0;
3809 				}
3810 				ipp->ipp_fields &= ~IPPF_DSTOPTS;
3811 				ipp->ipp_sticky_ignored |= IPPF_DSTOPTS;
3812 			} else {
3813 				error = udp_pkt_set(invalp, inlen, sticky,
3814 				    (uchar_t **)&ipp->ipp_dstopts,
3815 				    &ipp->ipp_dstoptslen);
3816 				if (error != 0)
3817 					return (error);
3818 				ipp->ipp_fields |= IPPF_DSTOPTS;
3819 			}
3820 			if (sticky) {
3821 				error = udp_build_hdrs(q, udp);
3822 				if (error != 0)
3823 					return (error);
3824 			}
3825 			break;
3826 		}
3827 		case IPV6_RTHDR: {
3828 			ip6_rthdr_t *rt = (ip6_rthdr_t *)invalp;
3829 
3830 			/*
3831 			 * Sanity checks - minimum size, size a multiple of
3832 			 * eight bytes, and matching size passed in.
3833 			 */
3834 			if (inlen != 0 &&
3835 			    inlen != (8 * (rt->ip6r_len + 1)))
3836 				return (EINVAL);
3837 
3838 			if (checkonly)
3839 				break;
3840 
3841 			if (inlen == 0) {
3842 				if (sticky &&
3843 				    (ipp->ipp_fields & IPPF_RTHDR) != 0) {
3844 					kmem_free(ipp->ipp_rthdr,
3845 					    ipp->ipp_rthdrlen);
3846 					ipp->ipp_rthdr = NULL;
3847 					ipp->ipp_rthdrlen = 0;
3848 				}
3849 				ipp->ipp_fields &= ~IPPF_RTHDR;
3850 				ipp->ipp_sticky_ignored |= IPPF_RTHDR;
3851 			} else {
3852 				error = udp_pkt_set(invalp, inlen, sticky,
3853 				    (uchar_t **)&ipp->ipp_rthdr,
3854 				    &ipp->ipp_rthdrlen);
3855 				if (error != 0)
3856 					return (error);
3857 				ipp->ipp_fields |= IPPF_RTHDR;
3858 			}
3859 			if (sticky) {
3860 				error = udp_build_hdrs(q, udp);
3861 				if (error != 0)
3862 					return (error);
3863 			}
3864 			break;
3865 		}
3866 
3867 		case IPV6_DONTFRAG:
3868 			if (checkonly)
3869 				break;
3870 
3871 			if (onoff) {
3872 				ipp->ipp_fields |= IPPF_DONTFRAG;
3873 			} else {
3874 				ipp->ipp_fields &= ~IPPF_DONTFRAG;
3875 			}
3876 			break;
3877 
3878 		case IPV6_USE_MIN_MTU:
3879 			if (inlen != sizeof (int))
3880 				return (EINVAL);
3881 
3882 			if (*i1 < -1 || *i1 > 1)
3883 				return (EINVAL);
3884 
3885 			if (checkonly)
3886 				break;
3887 
3888 			ipp->ipp_fields |= IPPF_USE_MIN_MTU;
3889 			ipp->ipp_use_min_mtu = *i1;
3890 			break;
3891 
3892 		case IPV6_BOUND_PIF:
3893 		case IPV6_SEC_OPT:
3894 		case IPV6_DONTFAILOVER_IF:
3895 		case IPV6_SRC_PREFERENCES:
3896 		case IPV6_V6ONLY:
3897 			/* Handled at the IP level */
3898 			return (-EINVAL);
3899 		default:
3900 			*outlenp = 0;
3901 			return (EINVAL);
3902 		}
3903 		break;
3904 		}		/* end IPPROTO_IPV6 */
3905 	case IPPROTO_UDP:
3906 		switch (name) {
3907 		case UDP_ANONPRIVBIND:
3908 			if ((error = secpolicy_net_privaddr(cr, 0)) != 0) {
3909 				*outlenp = 0;
3910 				return (error);
3911 			}
3912 			if (!checkonly) {
3913 				udp->udp_anon_priv_bind = onoff;
3914 			}
3915 			break;
3916 		case UDP_EXCLBIND:
3917 			if (!checkonly)
3918 				udp->udp_exclbind = onoff;
3919 			break;
3920 		case UDP_RCVHDR:
3921 			if (!checkonly)
3922 				udp->udp_rcvhdr = onoff;
3923 			break;
3924 		default:
3925 			*outlenp = 0;
3926 			return (EINVAL);
3927 		}
3928 		break;
3929 	default:
3930 		*outlenp = 0;
3931 		return (EINVAL);
3932 	}
3933 	/*
3934 	 * Common case of OK return with outval same as inval.
3935 	 */
3936 	if (invalp != outvalp) {
3937 		/* don't trust bcopy for identical src/dst */
3938 		(void) bcopy(invalp, outvalp, inlen);
3939 	}
3940 	*outlenp = inlen;
3941 	return (0);
3942 }
3943 
3944 /*
3945  * Update udp_sticky_hdrs based on udp_sticky_ipp, udp_v6src, and udp_ttl.
3946  * The headers include ip6i_t (if needed), ip6_t, any sticky extension
3947  * headers, and the udp header.
3948  * Returns failure if can't allocate memory.
3949  */
3950 static int
3951 udp_build_hdrs(queue_t *q, udp_t *udp)
3952 {
3953 	uchar_t	*hdrs;
3954 	uint_t	hdrs_len;
3955 	ip6_t	*ip6h;
3956 	ip6i_t	*ip6i;
3957 	udpha_t	*udpha;
3958 	ip6_pkt_t *ipp = &udp->udp_sticky_ipp;
3959 
3960 	hdrs_len = ip_total_hdrs_len_v6(ipp) + UDPH_SIZE;
3961 	ASSERT(hdrs_len != 0);
3962 	if (hdrs_len != udp->udp_sticky_hdrs_len) {
3963 		/* Need to reallocate */
3964 		hdrs = kmem_alloc(hdrs_len, KM_NOSLEEP);
3965 		if (hdrs == NULL)
3966 			return (ENOMEM);
3967 
3968 		if (udp->udp_sticky_hdrs_len != 0) {
3969 			kmem_free(udp->udp_sticky_hdrs,
3970 			    udp->udp_sticky_hdrs_len);
3971 		}
3972 		udp->udp_sticky_hdrs = hdrs;
3973 		udp->udp_sticky_hdrs_len = hdrs_len;
3974 	}
3975 	ip_build_hdrs_v6(udp->udp_sticky_hdrs,
3976 	    udp->udp_sticky_hdrs_len - UDPH_SIZE, ipp, IPPROTO_UDP);
3977 
3978 	/* Set header fields not in ipp */
3979 	if (ipp->ipp_fields & IPPF_HAS_IP6I) {
3980 		ip6i = (ip6i_t *)udp->udp_sticky_hdrs;
3981 		ip6h = (ip6_t *)&ip6i[1];
3982 	} else {
3983 		ip6h = (ip6_t *)udp->udp_sticky_hdrs;
3984 	}
3985 
3986 	if (!(ipp->ipp_fields & IPPF_ADDR))
3987 		ip6h->ip6_src = udp->udp_v6src;
3988 
3989 	udpha = (udpha_t *)(udp->udp_sticky_hdrs + hdrs_len - UDPH_SIZE);
3990 	udpha->uha_src_port = udp->udp_port;
3991 
3992 	/* Try to get everything in a single mblk */
3993 	if (hdrs_len > udp->udp_max_hdr_len) {
3994 		udp->udp_max_hdr_len = hdrs_len;
3995 		(void) mi_set_sth_wroff(RD(q), udp->udp_max_hdr_len +
3996 		    udp_wroff_extra);
3997 	}
3998 	return (0);
3999 }
4000 
4001 /*
4002  * Set optbuf and optlen for the option.
4003  * If sticky is set allocate memory (if not already present).
4004  * Otherwise just point optbuf and optlen at invalp and inlen.
4005  * Returns failure if memory can not be allocated.
4006  */
4007 static int
4008 udp_pkt_set(uchar_t *invalp, uint_t inlen, boolean_t sticky,
4009     uchar_t **optbufp, uint_t *optlenp)
4010 {
4011 	uchar_t *optbuf;
4012 
4013 	if (!sticky) {
4014 		*optbufp = invalp;
4015 		*optlenp = inlen;
4016 		return (0);
4017 	}
4018 	if (inlen == *optlenp) {
4019 		/* Unchanged length - no need to realocate */
4020 		bcopy(invalp, *optbufp, inlen);
4021 		return (0);
4022 	}
4023 	if (inlen != 0) {
4024 		/* Allocate new buffer before free */
4025 		optbuf = kmem_alloc(inlen, KM_NOSLEEP);
4026 		if (optbuf == NULL)
4027 			return (ENOMEM);
4028 	} else {
4029 		optbuf = NULL;
4030 	}
4031 	/* Free old buffer */
4032 	if (*optlenp != 0)
4033 		kmem_free(*optbufp, *optlenp);
4034 
4035 	bcopy(invalp, optbuf, inlen);
4036 	*optbufp = optbuf;
4037 	*optlenp = inlen;
4038 	return (0);
4039 }
4040 
4041 /*
4042  * This routine retrieves the value of an ND variable in a udpparam_t
4043  * structure.  It is called through nd_getset when a user reads the
4044  * variable.
4045  */
4046 /* ARGSUSED */
4047 static int
4048 udp_param_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr)
4049 {
4050 	udpparam_t *udppa = (udpparam_t *)cp;
4051 
4052 	(void) mi_mpprintf(mp, "%d", udppa->udp_param_value);
4053 	return (0);
4054 }
4055 
4056 /*
4057  * Walk through the param array specified registering each element with the
4058  * named dispatch (ND) handler.
4059  */
4060 static boolean_t
4061 udp_param_register(udpparam_t *udppa, int cnt)
4062 {
4063 	for (; cnt-- > 0; udppa++) {
4064 		if (udppa->udp_param_name && udppa->udp_param_name[0]) {
4065 			if (!nd_load(&udp_g_nd, udppa->udp_param_name,
4066 			    udp_param_get, udp_param_set,
4067 			    (caddr_t)udppa)) {
4068 				nd_free(&udp_g_nd);
4069 				return (B_FALSE);
4070 			}
4071 		}
4072 	}
4073 	if (!nd_load(&udp_g_nd, "udp_extra_priv_ports",
4074 	    udp_extra_priv_ports_get, NULL, NULL)) {
4075 		nd_free(&udp_g_nd);
4076 		return (B_FALSE);
4077 	}
4078 	if (!nd_load(&udp_g_nd, "udp_extra_priv_ports_add",
4079 	    NULL, udp_extra_priv_ports_add, NULL)) {
4080 		nd_free(&udp_g_nd);
4081 		return (B_FALSE);
4082 	}
4083 	if (!nd_load(&udp_g_nd, "udp_extra_priv_ports_del",
4084 	    NULL, udp_extra_priv_ports_del, NULL)) {
4085 		nd_free(&udp_g_nd);
4086 		return (B_FALSE);
4087 	}
4088 	if (!nd_load(&udp_g_nd, "udp_status", udp_status_report, NULL,
4089 	    NULL)) {
4090 		nd_free(&udp_g_nd);
4091 		return (B_FALSE);
4092 	}
4093 	if (!nd_load(&udp_g_nd, "udp_bind_hash", udp_bind_hash_report, NULL,
4094 	    NULL)) {
4095 		nd_free(&udp_g_nd);
4096 		return (B_FALSE);
4097 	}
4098 	return (B_TRUE);
4099 }
4100 
4101 /* This routine sets an ND variable in a udpparam_t structure. */
4102 /* ARGSUSED */
4103 static int
4104 udp_param_set(queue_t *q, mblk_t *mp, char *value, caddr_t cp, cred_t *cr)
4105 {
4106 	long		new_value;
4107 	udpparam_t	*udppa = (udpparam_t *)cp;
4108 
4109 	/*
4110 	 * Fail the request if the new value does not lie within the
4111 	 * required bounds.
4112 	 */
4113 	if (ddi_strtol(value, NULL, 10, &new_value) != 0 ||
4114 	    new_value < udppa->udp_param_min ||
4115 	    new_value > udppa->udp_param_max) {
4116 		return (EINVAL);
4117 	}
4118 
4119 	/* Set the new value */
4120 	udppa->udp_param_value = new_value;
4121 	return (0);
4122 }
4123 
4124 static void
4125 udp_input(conn_t *connp, mblk_t *mp)
4126 {
4127 	struct T_unitdata_ind	*tudi;
4128 	uchar_t			*rptr;		/* Pointer to IP header */
4129 	int			hdr_length;	/* Length of IP+UDP headers */
4130 	int			udi_size;	/* Size of T_unitdata_ind */
4131 	int			mp_len;
4132 	udp_t			*udp;
4133 	udpha_t			*udpha;
4134 	int			ipversion;
4135 	ip6_pkt_t		ipp;
4136 	ip6_t			*ip6h;
4137 	ip6i_t			*ip6i;
4138 	mblk_t			*mp1;
4139 	mblk_t			*options_mp = NULL;
4140 	in_pktinfo_t		*pinfo = NULL;
4141 	cred_t			*cr = NULL;
4142 	queue_t			*q = connp->conn_rq;
4143 	pid_t			cpid;
4144 
4145 	TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_START,
4146 	    "udp_rput_start: q %p mp %p", q, mp);
4147 
4148 	udp = connp->conn_udp;
4149 	rptr = mp->b_rptr;
4150 	ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_CTL);
4151 	ASSERT(OK_32PTR(rptr));
4152 
4153 	/*
4154 	 * IP should have prepended the options data in an M_CTL
4155 	 * Check M_CTL "type" to make sure are not here bcos of
4156 	 * a valid ICMP message
4157 	 */
4158 	if (DB_TYPE(mp) == M_CTL) {
4159 		if (MBLKL(mp) == sizeof (in_pktinfo_t) &&
4160 		    ((in_pktinfo_t *)mp->b_rptr)->in_pkt_ulp_type ==
4161 		    IN_PKTINFO) {
4162 			/*
4163 			 * IP_RECVIF or IP_RECVSLLA information has been
4164 			 * appended to the packet by IP. We need to
4165 			 * extract the mblk and adjust the rptr
4166 			 */
4167 			pinfo = (in_pktinfo_t *)mp->b_rptr;
4168 			options_mp = mp;
4169 			mp = mp->b_cont;
4170 			rptr = mp->b_rptr;
4171 			UDP_STAT(udp_in_pktinfo);
4172 		} else {
4173 			/*
4174 			 * ICMP messages.
4175 			 */
4176 			udp_icmp_error(q, mp);
4177 			TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4178 				"udp_rput_end: q %p (%S)", q, "m_ctl");
4179 			return;
4180 		}
4181 	}
4182 
4183 	mp_len = msgdsize(mp);
4184 	/*
4185 	 * This is the inbound data path.
4186 	 * First, we check to make sure the IP version number is correct,
4187 	 * and then pull the IP and UDP headers into the first mblk.
4188 	 * Assume IP provides aligned packets - otherwise toss.
4189 	 * Also, check if we have a complete IP header.
4190 	 */
4191 
4192 	/* Initialize regardless if ipversion is IPv4 or IPv6 */
4193 	ipp.ipp_fields = 0;
4194 
4195 	ipversion = IPH_HDR_VERSION(rptr);
4196 	switch (ipversion) {
4197 	case IPV4_VERSION:
4198 		ASSERT(MBLKL(mp) >= sizeof (ipha_t));
4199 		ASSERT(((ipha_t *)rptr)->ipha_protocol == IPPROTO_UDP);
4200 		hdr_length = IPH_HDR_LENGTH(rptr) + UDPH_SIZE;
4201 		if ((hdr_length > IP_SIMPLE_HDR_LENGTH + UDPH_SIZE) ||
4202 		    (udp->udp_ip_rcv_options_len)) {
4203 			/*
4204 			 * Handle IPv4 packets with options outside of the
4205 			 * main data path. Not needed for AF_INET6 sockets
4206 			 * since they don't support a getsockopt of IP_OPTIONS.
4207 			 */
4208 			if (udp->udp_family == AF_INET6)
4209 				break;
4210 			/*
4211 			 * UDP length check performed for IPv4 packets with
4212 			 * options to check whether UDP length specified in
4213 			 * the header is the same as the physical length of
4214 			 * the packet.
4215 			 */
4216 			udpha = (udpha_t *)(rptr + (hdr_length - UDPH_SIZE));
4217 			if (mp_len != (ntohs(udpha->uha_length) +
4218 			    hdr_length - UDPH_SIZE)) {
4219 				goto tossit;
4220 			}
4221 			/*
4222 			 * Handle the case where the packet has IP options
4223 			 * and the IP_RECVSLLA & IP_RECVIF are set
4224 			 */
4225 			if (pinfo != NULL)
4226 				mp = options_mp;
4227 			udp_become_writer(connp, mp, udp_rput_other_wrapper,
4228 			    SQTAG_UDP_INPUT);
4229 			TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4230 				"udp_rput_end: q %p (%S)", q, "end");
4231 			return;
4232 		}
4233 
4234 		/* Handle IPV6_RECVHOPLIMIT. */
4235 		if ((udp->udp_family == AF_INET6) && (pinfo != NULL) &&
4236 		    udp->udp_ipv6_recvpktinfo) {
4237 			if (pinfo->in_pkt_flags & IPF_RECVIF) {
4238 				ipp.ipp_fields |= IPPF_IFINDEX;
4239 				ipp.ipp_ifindex = pinfo->in_pkt_ifindex;
4240 			}
4241 		}
4242 		break;
4243 	case IPV6_VERSION:
4244 		/*
4245 		 * IPv6 packets can only be received by applications
4246 		 * that are prepared to receive IPv6 addresses.
4247 		 * The IP fanout must ensure this.
4248 		 */
4249 		ASSERT(udp->udp_family == AF_INET6);
4250 
4251 		ip6h = (ip6_t *)rptr;
4252 		ASSERT((uchar_t *)&ip6h[1] <= mp->b_wptr);
4253 
4254 		if (ip6h->ip6_nxt != IPPROTO_UDP) {
4255 			uint8_t nexthdrp;
4256 			/* Look for ifindex information */
4257 			if (ip6h->ip6_nxt == IPPROTO_RAW) {
4258 				ip6i = (ip6i_t *)ip6h;
4259 				if ((uchar_t *)&ip6i[1] > mp->b_wptr)
4260 					goto tossit;
4261 
4262 				if (ip6i->ip6i_flags & IP6I_IFINDEX) {
4263 					ASSERT(ip6i->ip6i_ifindex != 0);
4264 					ipp.ipp_fields |= IPPF_IFINDEX;
4265 					ipp.ipp_ifindex = ip6i->ip6i_ifindex;
4266 				}
4267 				rptr = (uchar_t *)&ip6i[1];
4268 				mp->b_rptr = rptr;
4269 				if (rptr == mp->b_wptr) {
4270 					mp1 = mp->b_cont;
4271 					freeb(mp);
4272 					mp = mp1;
4273 					rptr = mp->b_rptr;
4274 				}
4275 				if (MBLKL(mp) < (IPV6_HDR_LEN + UDPH_SIZE))
4276 					goto tossit;
4277 				ip6h = (ip6_t *)rptr;
4278 				mp_len = msgdsize(mp);
4279 			}
4280 			/*
4281 			 * Find any potentially interesting extension headers
4282 			 * as well as the length of the IPv6 + extension
4283 			 * headers.
4284 			 */
4285 			hdr_length = ip_find_hdr_v6(mp, ip6h, &ipp, &nexthdrp) +
4286 			    UDPH_SIZE;
4287 			ASSERT(nexthdrp == IPPROTO_UDP);
4288 		} else {
4289 			hdr_length = IPV6_HDR_LEN + UDPH_SIZE;
4290 			ip6i = NULL;
4291 		}
4292 		break;
4293 	default:
4294 		ASSERT(0);
4295 	}
4296 
4297 	/*
4298 	 * IP inspected the UDP header thus all of it must be in the mblk.
4299 	 * UDP length check is performed for IPv6 packets and IPv4 packets
4300 	 * without options to check if the size of the packet as specified
4301 	 * by the header is the same as the physical size of the packet.
4302 	 */
4303 	udpha = (udpha_t *)(rptr + (hdr_length - UDPH_SIZE));
4304 	if ((MBLKL(mp) < hdr_length) ||
4305 	    (mp_len != (ntohs(udpha->uha_length) + hdr_length - UDPH_SIZE))) {
4306 		goto tossit;
4307 	}
4308 
4309 	/* Walk past the headers. */
4310 	if (!udp->udp_rcvhdr) {
4311 		mp->b_rptr = rptr + hdr_length;
4312 		mp_len -= hdr_length;
4313 	}
4314 
4315 	/*
4316 	 * This is the inbound data path.  Packets are passed upstream as
4317 	 * T_UNITDATA_IND messages with full IP headers still attached.
4318 	 */
4319 	if (udp->udp_family == AF_INET) {
4320 		sin_t *sin;
4321 
4322 		ASSERT(IPH_HDR_VERSION((ipha_t *)rptr) == IPV4_VERSION);
4323 
4324 		/*
4325 		 * Normally only send up the address.
4326 		 * If IP_RECVDSTADDR is set we include the destination IP
4327 		 * address as an option. With IP_RECVOPTS we include all
4328 		 * the IP options. Only ip_rput_other() handles packets
4329 		 * that contain IP options.
4330 		 */
4331 		udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin_t);
4332 		if (udp->udp_recvdstaddr) {
4333 			udi_size += sizeof (struct T_opthdr) +
4334 			    sizeof (struct in_addr);
4335 			UDP_STAT(udp_in_recvdstaddr);
4336 		}
4337 
4338 		/*
4339 		 * If the IP_RECVSLLA or the IP_RECVIF is set then allocate
4340 		 * space accordingly
4341 		 */
4342 		if (udp->udp_recvif && (pinfo != NULL) &&
4343 		    (pinfo->in_pkt_flags & IPF_RECVIF)) {
4344 			udi_size += sizeof (struct T_opthdr) + sizeof (uint_t);
4345 			UDP_STAT(udp_in_recvif);
4346 		}
4347 
4348 		if (udp->udp_recvslla && (pinfo != NULL) &&
4349 		    (pinfo->in_pkt_flags & IPF_RECVSLLA)) {
4350 			udi_size += sizeof (struct T_opthdr) +
4351 			    sizeof (struct sockaddr_dl);
4352 			UDP_STAT(udp_in_recvslla);
4353 		}
4354 
4355 		if (udp->udp_recvucred && (cr = DB_CRED(mp)) != NULL) {
4356 			udi_size += sizeof (struct T_opthdr) + ucredsize;
4357 			cpid = DB_CPID(mp);
4358 			UDP_STAT(udp_in_recvucred);
4359 		}
4360 		/*
4361 		 * If IP_RECVTTL is set allocate the appropriate sized buffer
4362 		 */
4363 		if (udp->udp_recvttl) {
4364 			udi_size += sizeof (struct T_opthdr) + sizeof (uint8_t);
4365 			UDP_STAT(udp_in_recvttl);
4366 		}
4367 
4368 		ASSERT(IPH_HDR_LENGTH((ipha_t *)rptr) == IP_SIMPLE_HDR_LENGTH);
4369 
4370 		/* Allocate a message block for the T_UNITDATA_IND structure. */
4371 		mp1 = allocb(udi_size, BPRI_MED);
4372 		if (mp1 == NULL) {
4373 			freemsg(mp);
4374 			if (options_mp != NULL)
4375 				freeb(options_mp);
4376 			TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4377 				"udp_rput_end: q %p (%S)", q, "allocbfail");
4378 			BUMP_MIB(&udp_mib, udpInErrors);
4379 			return;
4380 		}
4381 		mp1->b_cont = mp;
4382 		mp = mp1;
4383 		mp->b_datap->db_type = M_PROTO;
4384 		tudi = (struct T_unitdata_ind *)mp->b_rptr;
4385 		mp->b_wptr = (uchar_t *)tudi + udi_size;
4386 		tudi->PRIM_type = T_UNITDATA_IND;
4387 		tudi->SRC_length = sizeof (sin_t);
4388 		tudi->SRC_offset = sizeof (struct T_unitdata_ind);
4389 		tudi->OPT_offset = sizeof (struct T_unitdata_ind) +
4390 		    sizeof (sin_t);
4391 		udi_size -= (sizeof (struct T_unitdata_ind) + sizeof (sin_t));
4392 		tudi->OPT_length = udi_size;
4393 		sin = (sin_t *)&tudi[1];
4394 		sin->sin_addr.s_addr = ((ipha_t *)rptr)->ipha_src;
4395 		sin->sin_port =	udpha->uha_src_port;
4396 		sin->sin_family = udp->udp_family;
4397 		*(uint32_t *)&sin->sin_zero[0] = 0;
4398 		*(uint32_t *)&sin->sin_zero[4] = 0;
4399 
4400 		/*
4401 		 * Add options if IP_RECVDSTADDR, IP_RECVIF, IP_RECVSLLA or
4402 		 * IP_RECVTTL has been set.
4403 		 */
4404 		if (udi_size != 0) {
4405 			/*
4406 			 * Copy in destination address before options to avoid
4407 			 * any padding issues.
4408 			 */
4409 			char *dstopt;
4410 
4411 			dstopt = (char *)&sin[1];
4412 			if (udp->udp_recvdstaddr) {
4413 				struct T_opthdr *toh;
4414 				ipaddr_t *dstptr;
4415 
4416 				toh = (struct T_opthdr *)dstopt;
4417 				toh->level = IPPROTO_IP;
4418 				toh->name = IP_RECVDSTADDR;
4419 				toh->len = sizeof (struct T_opthdr) +
4420 				    sizeof (ipaddr_t);
4421 				toh->status = 0;
4422 				dstopt += sizeof (struct T_opthdr);
4423 				dstptr = (ipaddr_t *)dstopt;
4424 				*dstptr = ((ipha_t *)rptr)->ipha_dst;
4425 				dstopt += sizeof (ipaddr_t);
4426 				udi_size -= toh->len;
4427 			}
4428 
4429 			if (udp->udp_recvslla && (pinfo != NULL) &&
4430 			    (pinfo->in_pkt_flags & IPF_RECVSLLA)) {
4431 
4432 				struct T_opthdr *toh;
4433 				struct sockaddr_dl	*dstptr;
4434 
4435 				toh = (struct T_opthdr *)dstopt;
4436 				toh->level = IPPROTO_IP;
4437 				toh->name = IP_RECVSLLA;
4438 				toh->len = sizeof (struct T_opthdr) +
4439 					sizeof (struct sockaddr_dl);
4440 				toh->status = 0;
4441 				dstopt += sizeof (struct T_opthdr);
4442 				dstptr = (struct sockaddr_dl *)dstopt;
4443 				bcopy(&pinfo->in_pkt_slla, dstptr,
4444 				    sizeof (struct sockaddr_dl));
4445 				dstopt += sizeof (struct sockaddr_dl);
4446 				udi_size -= toh->len;
4447 			}
4448 
4449 			if (udp->udp_recvif && (pinfo != NULL) &&
4450 			    (pinfo->in_pkt_flags & IPF_RECVIF)) {
4451 
4452 				struct T_opthdr *toh;
4453 				uint_t		*dstptr;
4454 
4455 				toh = (struct T_opthdr *)dstopt;
4456 				toh->level = IPPROTO_IP;
4457 				toh->name = IP_RECVIF;
4458 				toh->len = sizeof (struct T_opthdr) +
4459 					sizeof (uint_t);
4460 				toh->status = 0;
4461 				dstopt += sizeof (struct T_opthdr);
4462 				dstptr = (uint_t *)dstopt;
4463 				*dstptr = pinfo->in_pkt_ifindex;
4464 				dstopt += sizeof (uint_t);
4465 				udi_size -= toh->len;
4466 			}
4467 
4468 			if (cr != NULL) {
4469 				struct T_opthdr *toh;
4470 
4471 				toh = (struct T_opthdr *)dstopt;
4472 				toh->level = SOL_SOCKET;
4473 				toh->name = SCM_UCRED;
4474 				toh->len = sizeof (struct T_opthdr) + ucredsize;
4475 				toh->status = 0;
4476 				(void) cred2ucred(cr, cpid, &toh[1]);
4477 				dstopt += toh->len;
4478 				udi_size -= toh->len;
4479 			}
4480 
4481 			if (udp->udp_recvttl) {
4482 				struct	T_opthdr *toh;
4483 				uint8_t	*dstptr;
4484 
4485 				toh = (struct T_opthdr *)dstopt;
4486 				toh->level = IPPROTO_IP;
4487 				toh->name = IP_RECVTTL;
4488 				toh->len = sizeof (struct T_opthdr) +
4489 				    sizeof (uint8_t);
4490 				toh->status = 0;
4491 				dstopt += sizeof (struct T_opthdr);
4492 				dstptr = (uint8_t *)dstopt;
4493 				*dstptr = ((ipha_t *)rptr)->ipha_ttl;
4494 				dstopt += sizeof (uint8_t);
4495 				udi_size -= toh->len;
4496 			}
4497 
4498 			/* Consumed all of allocated space */
4499 			ASSERT(udi_size == 0);
4500 		}
4501 	} else {
4502 		sin6_t *sin6;
4503 
4504 		/*
4505 		 * Handle both IPv4 and IPv6 packets for IPv6 sockets.
4506 		 *
4507 		 * Normally we only send up the address. If receiving of any
4508 		 * optional receive side information is enabled, we also send
4509 		 * that up as options.
4510 		 * [ Only udp_rput_other() handles packets that contain IP
4511 		 * options so code to account for does not appear immediately
4512 		 * below but elsewhere ]
4513 		 */
4514 		udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin6_t);
4515 
4516 		if (ipp.ipp_fields & (IPPF_HOPOPTS|IPPF_DSTOPTS|IPPF_RTDSTOPTS|
4517 		    IPPF_RTHDR|IPPF_IFINDEX)) {
4518 			if (udp->udp_ipv6_recvhopopts &&
4519 			    (ipp.ipp_fields & IPPF_HOPOPTS)) {
4520 				udi_size += sizeof (struct T_opthdr) +
4521 				    ipp.ipp_hopoptslen;
4522 				UDP_STAT(udp_in_recvhopopts);
4523 			}
4524 			if ((udp->udp_ipv6_recvdstopts ||
4525 				udp->udp_old_ipv6_recvdstopts) &&
4526 			    (ipp.ipp_fields & IPPF_DSTOPTS)) {
4527 				udi_size += sizeof (struct T_opthdr) +
4528 				    ipp.ipp_dstoptslen;
4529 				UDP_STAT(udp_in_recvdstopts);
4530 			}
4531 			if (((udp->udp_ipv6_recvdstopts &&
4532 			    udp->udp_ipv6_recvrthdr &&
4533 			    (ipp.ipp_fields & IPPF_RTHDR)) ||
4534 			    udp->udp_ipv6_recvrthdrdstopts) &&
4535 			    (ipp.ipp_fields & IPPF_RTDSTOPTS)) {
4536 				udi_size += sizeof (struct T_opthdr) +
4537 				    ipp.ipp_rtdstoptslen;
4538 				UDP_STAT(udp_in_recvrtdstopts);
4539 			}
4540 			if (udp->udp_ipv6_recvrthdr &&
4541 			    (ipp.ipp_fields & IPPF_RTHDR)) {
4542 				udi_size += sizeof (struct T_opthdr) +
4543 				    ipp.ipp_rthdrlen;
4544 				UDP_STAT(udp_in_recvrthdr);
4545 			}
4546 			if (udp->udp_ipv6_recvpktinfo &&
4547 			    (ipp.ipp_fields & IPPF_IFINDEX)) {
4548 				udi_size += sizeof (struct T_opthdr) +
4549 				    sizeof (struct in6_pktinfo);
4550 				UDP_STAT(udp_in_recvpktinfo);
4551 			}
4552 
4553 		}
4554 		if (udp->udp_recvucred && (cr = DB_CRED(mp)) != NULL) {
4555 			udi_size += sizeof (struct T_opthdr) + ucredsize;
4556 			cpid = DB_CPID(mp);
4557 			UDP_STAT(udp_in_recvucred);
4558 		}
4559 
4560 		if (udp->udp_ipv6_recvhoplimit) {
4561 			udi_size += sizeof (struct T_opthdr) + sizeof (int);
4562 			UDP_STAT(udp_in_recvhoplimit);
4563 		}
4564 
4565 		if (udp->udp_ipv6_recvtclass) {
4566 			udi_size += sizeof (struct T_opthdr) + sizeof (int);
4567 			UDP_STAT(udp_in_recvtclass);
4568 		}
4569 
4570 		mp1 = allocb(udi_size, BPRI_MED);
4571 		if (mp1 == NULL) {
4572 			freemsg(mp);
4573 			if (options_mp != NULL)
4574 				freeb(options_mp);
4575 			TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4576 				"udp_rput_end: q %p (%S)", q, "allocbfail");
4577 			BUMP_MIB(&udp_mib, udpInErrors);
4578 			return;
4579 		}
4580 		mp1->b_cont = mp;
4581 		mp = mp1;
4582 		mp->b_datap->db_type = M_PROTO;
4583 		tudi = (struct T_unitdata_ind *)mp->b_rptr;
4584 		mp->b_wptr = (uchar_t *)tudi + udi_size;
4585 		tudi->PRIM_type = T_UNITDATA_IND;
4586 		tudi->SRC_length = sizeof (sin6_t);
4587 		tudi->SRC_offset = sizeof (struct T_unitdata_ind);
4588 		tudi->OPT_offset = sizeof (struct T_unitdata_ind) +
4589 		    sizeof (sin6_t);
4590 		udi_size -= (sizeof (struct T_unitdata_ind) + sizeof (sin6_t));
4591 		tudi->OPT_length = udi_size;
4592 		sin6 = (sin6_t *)&tudi[1];
4593 		if (ipversion == IPV4_VERSION) {
4594 			in6_addr_t v6dst;
4595 
4596 			IN6_IPADDR_TO_V4MAPPED(((ipha_t *)rptr)->ipha_src,
4597 			    &sin6->sin6_addr);
4598 			IN6_IPADDR_TO_V4MAPPED(((ipha_t *)rptr)->ipha_dst,
4599 			    &v6dst);
4600 			sin6->sin6_flowinfo = 0;
4601 			sin6->sin6_scope_id = 0;
4602 			sin6->__sin6_src_id = ip_srcid_find_addr(&v6dst,
4603 			    connp->conn_zoneid);
4604 		} else {
4605 			sin6->sin6_addr = ip6h->ip6_src;
4606 			/* No sin6_flowinfo per API */
4607 			sin6->sin6_flowinfo = 0;
4608 			/* For link-scope source pass up scope id */
4609 			if ((ipp.ipp_fields & IPPF_IFINDEX) &&
4610 			    IN6_IS_ADDR_LINKSCOPE(&ip6h->ip6_src))
4611 				sin6->sin6_scope_id = ipp.ipp_ifindex;
4612 			else
4613 				sin6->sin6_scope_id = 0;
4614 			sin6->__sin6_src_id = ip_srcid_find_addr(
4615 			    &ip6h->ip6_dst, connp->conn_zoneid);
4616 		}
4617 		sin6->sin6_port = udpha->uha_src_port;
4618 		sin6->sin6_family = udp->udp_family;
4619 
4620 		if (udi_size != 0) {
4621 			uchar_t *dstopt;
4622 
4623 			dstopt = (uchar_t *)&sin6[1];
4624 			if (udp->udp_ipv6_recvpktinfo &&
4625 			    (ipp.ipp_fields & IPPF_IFINDEX)) {
4626 				struct T_opthdr *toh;
4627 				struct in6_pktinfo *pkti;
4628 
4629 				toh = (struct T_opthdr *)dstopt;
4630 				toh->level = IPPROTO_IPV6;
4631 				toh->name = IPV6_PKTINFO;
4632 				toh->len = sizeof (struct T_opthdr) +
4633 				    sizeof (*pkti);
4634 				toh->status = 0;
4635 				dstopt += sizeof (struct T_opthdr);
4636 				pkti = (struct in6_pktinfo *)dstopt;
4637 				if (ipversion == IPV6_VERSION)
4638 					pkti->ipi6_addr = ip6h->ip6_dst;
4639 				else
4640 					IN6_IPADDR_TO_V4MAPPED(
4641 						((ipha_t *)rptr)->ipha_dst,
4642 						    &pkti->ipi6_addr);
4643 				pkti->ipi6_ifindex = ipp.ipp_ifindex;
4644 				dstopt += sizeof (*pkti);
4645 				udi_size -= toh->len;
4646 			}
4647 			if (udp->udp_ipv6_recvhoplimit) {
4648 				struct T_opthdr *toh;
4649 
4650 				toh = (struct T_opthdr *)dstopt;
4651 				toh->level = IPPROTO_IPV6;
4652 				toh->name = IPV6_HOPLIMIT;
4653 				toh->len = sizeof (struct T_opthdr) +
4654 				    sizeof (uint_t);
4655 				toh->status = 0;
4656 				dstopt += sizeof (struct T_opthdr);
4657 				if (ipversion == IPV6_VERSION)
4658 					*(uint_t *)dstopt = ip6h->ip6_hops;
4659 				else
4660 					*(uint_t *)dstopt =
4661 					    ((ipha_t *)rptr)->ipha_ttl;
4662 				dstopt += sizeof (uint_t);
4663 				udi_size -= toh->len;
4664 			}
4665 			if (udp->udp_ipv6_recvtclass) {
4666 				struct T_opthdr *toh;
4667 
4668 				toh = (struct T_opthdr *)dstopt;
4669 				toh->level = IPPROTO_IPV6;
4670 				toh->name = IPV6_TCLASS;
4671 				toh->len = sizeof (struct T_opthdr) +
4672 				    sizeof (uint_t);
4673 				toh->status = 0;
4674 				dstopt += sizeof (struct T_opthdr);
4675 				if (ipversion == IPV6_VERSION) {
4676 					*(uint_t *)dstopt =
4677 					IPV6_FLOW_TCLASS(ip6h->ip6_flow);
4678 				} else {
4679 					ipha_t *ipha = (ipha_t *)rptr;
4680 					*(uint_t *)dstopt =
4681 					    ipha->ipha_type_of_service;
4682 				}
4683 				dstopt += sizeof (uint_t);
4684 				udi_size -= toh->len;
4685 			}
4686 			if (udp->udp_ipv6_recvhopopts &&
4687 			    (ipp.ipp_fields & IPPF_HOPOPTS)) {
4688 				struct T_opthdr *toh;
4689 
4690 				toh = (struct T_opthdr *)dstopt;
4691 				toh->level = IPPROTO_IPV6;
4692 				toh->name = IPV6_HOPOPTS;
4693 				toh->len = sizeof (struct T_opthdr) +
4694 				    ipp.ipp_hopoptslen;
4695 				toh->status = 0;
4696 				dstopt += sizeof (struct T_opthdr);
4697 				bcopy(ipp.ipp_hopopts, dstopt,
4698 				    ipp.ipp_hopoptslen);
4699 				dstopt += ipp.ipp_hopoptslen;
4700 				udi_size -= toh->len;
4701 			}
4702 			if (udp->udp_ipv6_recvdstopts &&
4703 			    udp->udp_ipv6_recvrthdr &&
4704 			    (ipp.ipp_fields & IPPF_RTHDR) &&
4705 			    (ipp.ipp_fields & IPPF_RTDSTOPTS)) {
4706 				struct T_opthdr *toh;
4707 
4708 				toh = (struct T_opthdr *)dstopt;
4709 				toh->level = IPPROTO_IPV6;
4710 				toh->name = IPV6_DSTOPTS;
4711 				toh->len = sizeof (struct T_opthdr) +
4712 				    ipp.ipp_rtdstoptslen;
4713 				toh->status = 0;
4714 				dstopt += sizeof (struct T_opthdr);
4715 				bcopy(ipp.ipp_rtdstopts, dstopt,
4716 				    ipp.ipp_rtdstoptslen);
4717 				dstopt += ipp.ipp_rtdstoptslen;
4718 				udi_size -= toh->len;
4719 			}
4720 			if (udp->udp_ipv6_recvrthdr &&
4721 			    (ipp.ipp_fields & IPPF_RTHDR)) {
4722 				struct T_opthdr *toh;
4723 
4724 				toh = (struct T_opthdr *)dstopt;
4725 				toh->level = IPPROTO_IPV6;
4726 				toh->name = IPV6_RTHDR;
4727 				toh->len = sizeof (struct T_opthdr) +
4728 				    ipp.ipp_rthdrlen;
4729 				toh->status = 0;
4730 				dstopt += sizeof (struct T_opthdr);
4731 				bcopy(ipp.ipp_rthdr, dstopt, ipp.ipp_rthdrlen);
4732 				dstopt += ipp.ipp_rthdrlen;
4733 				udi_size -= toh->len;
4734 			}
4735 			if (udp->udp_ipv6_recvdstopts &&
4736 			    (ipp.ipp_fields & IPPF_DSTOPTS)) {
4737 				struct T_opthdr *toh;
4738 
4739 				toh = (struct T_opthdr *)dstopt;
4740 				toh->level = IPPROTO_IPV6;
4741 				toh->name = IPV6_DSTOPTS;
4742 				toh->len = sizeof (struct T_opthdr) +
4743 				    ipp.ipp_dstoptslen;
4744 				toh->status = 0;
4745 				dstopt += sizeof (struct T_opthdr);
4746 				bcopy(ipp.ipp_dstopts, dstopt,
4747 				    ipp.ipp_dstoptslen);
4748 				dstopt += ipp.ipp_dstoptslen;
4749 				udi_size -= toh->len;
4750 			}
4751 
4752 			if (cr != NULL) {
4753 				struct T_opthdr *toh;
4754 
4755 				toh = (struct T_opthdr *)dstopt;
4756 				toh->level = SOL_SOCKET;
4757 				toh->name = SCM_UCRED;
4758 				toh->len = sizeof (struct T_opthdr) + ucredsize;
4759 				toh->status = 0;
4760 				(void) cred2ucred(cr, cpid, &toh[1]);
4761 				dstopt += toh->len;
4762 				udi_size -= toh->len;
4763 			}
4764 			/* Consumed all of allocated space */
4765 			ASSERT(udi_size == 0);
4766 		}
4767 #undef	sin6
4768 		/* No IP_RECVDSTADDR for IPv6. */
4769 	}
4770 
4771 	BUMP_MIB(&udp_mib, udpInDatagrams);
4772 	TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4773 		"udp_rput_end: q %p (%S)", q, "end");
4774 	if (options_mp != NULL)
4775 		freeb(options_mp);
4776 
4777 	if (udp->udp_direct_sockfs) {
4778 		/*
4779 		 * There is nothing above us except for the stream head;
4780 		 * use the read-side synchronous stream interface in
4781 		 * order to reduce the time spent in interrupt thread.
4782 		 */
4783 		ASSERT(udp->udp_issocket);
4784 		udp_rcv_enqueue(UDP_RD(q), udp, mp, mp_len);
4785 	} else {
4786 		/*
4787 		 * Use regular STREAMS interface to pass data upstream
4788 		 * if this is not a socket endpoint, or if we have
4789 		 * switched over to the slow mode due to sockmod being
4790 		 * popped or a module being pushed on top of us.
4791 		 */
4792 		putnext(UDP_RD(q), mp);
4793 	}
4794 	return;
4795 
4796 tossit:
4797 	freemsg(mp);
4798 	if (options_mp != NULL)
4799 		freeb(options_mp);
4800 	BUMP_MIB(&udp_mib, udpInErrors);
4801 }
4802 
4803 void
4804 udp_conn_recv(conn_t *connp, mblk_t *mp)
4805 {
4806 	_UDP_ENTER(connp, mp, udp_input_wrapper, SQTAG_UDP_FANOUT);
4807 }
4808 
4809 /* ARGSUSED */
4810 static void
4811 udp_input_wrapper(void *arg, mblk_t *mp, void *arg2)
4812 {
4813 	udp_input((conn_t *)arg, mp);
4814 	_UDP_EXIT((conn_t *)arg);
4815 }
4816 
4817 /*
4818  * Process non-M_DATA messages as well as M_DATA messages that requires
4819  * modifications to udp_ip_rcv_options i.e. IPv4 packets with IP options.
4820  */
4821 static void
4822 udp_rput_other(queue_t *q, mblk_t *mp)
4823 {
4824 	struct T_unitdata_ind	*tudi;
4825 	mblk_t			*mp1;
4826 	uchar_t			*rptr;
4827 	uchar_t			*new_rptr;
4828 	int			hdr_length;
4829 	int			udi_size;	/* Size of T_unitdata_ind */
4830 	int			opt_len;	/* Length of IP options */
4831 	sin_t			*sin;
4832 	struct T_error_ack	*tea;
4833 	mblk_t			*options_mp = NULL;
4834 	in_pktinfo_t		*pinfo;
4835 	boolean_t		recv_on = B_FALSE;
4836 	cred_t			*cr = NULL;
4837 	udp_t			*udp = Q_TO_UDP(q);
4838 	pid_t			cpid;
4839 
4840 	TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_START,
4841 	    "udp_rput_other: q %p mp %p", q, mp);
4842 
4843 	ASSERT(OK_32PTR(mp->b_rptr));
4844 	rptr = mp->b_rptr;
4845 
4846 	switch (mp->b_datap->db_type) {
4847 	case M_CTL:
4848 		/*
4849 		 * We are here only if IP_RECVSLLA and/or IP_RECVIF are set
4850 		 */
4851 		recv_on = B_TRUE;
4852 		options_mp = mp;
4853 		pinfo = (in_pktinfo_t *)options_mp->b_rptr;
4854 
4855 		/*
4856 		 * The actual data is in mp->b_cont
4857 		 */
4858 		mp = mp->b_cont;
4859 		ASSERT(OK_32PTR(mp->b_rptr));
4860 		rptr = mp->b_rptr;
4861 		break;
4862 	case M_DATA:
4863 		/*
4864 		 * M_DATA messages contain IPv4 datagrams.  They are handled
4865 		 * after this switch.
4866 		 */
4867 		break;
4868 	case M_PROTO:
4869 	case M_PCPROTO:
4870 		/* M_PROTO messages contain some type of TPI message. */
4871 		ASSERT((uintptr_t)(mp->b_wptr - rptr) <= (uintptr_t)INT_MAX);
4872 		if (mp->b_wptr - rptr < sizeof (t_scalar_t)) {
4873 			freemsg(mp);
4874 			TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4875 			    "udp_rput_other_end: q %p (%S)", q, "protoshort");
4876 			return;
4877 		}
4878 		tea = (struct T_error_ack *)rptr;
4879 
4880 		switch (tea->PRIM_type) {
4881 		case T_ERROR_ACK:
4882 			switch (tea->ERROR_prim) {
4883 			case O_T_BIND_REQ:
4884 			case T_BIND_REQ: {
4885 				/*
4886 				 * If our O_T_BIND_REQ/T_BIND_REQ fails,
4887 				 * clear out the associated port and source
4888 				 * address before passing the message
4889 				 * upstream. If this was caused by a T_CONN_REQ
4890 				 * revert back to bound state.
4891 				 */
4892 				udp_fanout_t	*udpf;
4893 
4894 				udpf = &udp_bind_fanout[
4895 				    UDP_BIND_HASH(udp->udp_port)];
4896 				mutex_enter(&udpf->uf_lock);
4897 				if (udp->udp_state == TS_DATA_XFER) {
4898 					/* Connect failed */
4899 					tea->ERROR_prim = T_CONN_REQ;
4900 					/* Revert back to the bound source */
4901 					udp->udp_v6src = udp->udp_bound_v6src;
4902 					udp->udp_state = TS_IDLE;
4903 					mutex_exit(&udpf->uf_lock);
4904 					if (udp->udp_family == AF_INET6)
4905 						(void) udp_build_hdrs(q, udp);
4906 					break;
4907 				}
4908 
4909 				if (udp->udp_discon_pending) {
4910 					tea->ERROR_prim = T_DISCON_REQ;
4911 					udp->udp_discon_pending = 0;
4912 				}
4913 				V6_SET_ZERO(udp->udp_v6src);
4914 				V6_SET_ZERO(udp->udp_bound_v6src);
4915 				udp->udp_state = TS_UNBND;
4916 				udp_bind_hash_remove(udp, B_TRUE);
4917 				udp->udp_port = 0;
4918 				mutex_exit(&udpf->uf_lock);
4919 				if (udp->udp_family == AF_INET6)
4920 					(void) udp_build_hdrs(q, udp);
4921 				break;
4922 			}
4923 			default:
4924 				break;
4925 			}
4926 			break;
4927 		case T_BIND_ACK:
4928 			udp_rput_bind_ack(q, mp);
4929 			return;
4930 
4931 		case T_OPTMGMT_ACK:
4932 		case T_OK_ACK:
4933 			break;
4934 		default:
4935 			freemsg(mp);
4936 			return;
4937 		}
4938 		putnext(UDP_RD(q), mp);
4939 		return;
4940 	}
4941 
4942 	/*
4943 	 * This is the inbound data path.
4944 	 * First, we make sure the data contains both IP and UDP headers.
4945 	 *
4946 	 * This handle IPv4 packets for only AF_INET sockets.
4947 	 * AF_INET6 sockets can never access udp_ip_rcv_options thus there
4948 	 * is no need saving the options.
4949 	 */
4950 	ASSERT(IPH_HDR_VERSION((ipha_t *)rptr) == IPV4_VERSION);
4951 	hdr_length = IPH_HDR_LENGTH(rptr) + UDPH_SIZE;
4952 	if (mp->b_wptr - rptr < hdr_length) {
4953 		if (!pullupmsg(mp, hdr_length)) {
4954 			freemsg(mp);
4955 			if (options_mp != NULL)
4956 				freeb(options_mp);
4957 			BUMP_MIB(&udp_mib, udpInErrors);
4958 			TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
4959 			    "udp_rput_other_end: q %p (%S)", q, "hdrshort");
4960 			BUMP_MIB(&udp_mib, udpInErrors);
4961 			return;
4962 		}
4963 		rptr = mp->b_rptr;
4964 	}
4965 	/* Walk past the headers. */
4966 	new_rptr = rptr + hdr_length;
4967 	if (!udp->udp_rcvhdr)
4968 		mp->b_rptr = new_rptr;
4969 
4970 	/* Save the options if any */
4971 	opt_len = hdr_length - (IP_SIMPLE_HDR_LENGTH + UDPH_SIZE);
4972 	if (opt_len > 0) {
4973 		if (opt_len > udp->udp_ip_rcv_options_len) {
4974 			if (udp->udp_ip_rcv_options_len)
4975 				mi_free((char *)udp->udp_ip_rcv_options);
4976 			udp->udp_ip_rcv_options_len = 0;
4977 			udp->udp_ip_rcv_options =
4978 			    (uchar_t *)mi_alloc(opt_len, BPRI_HI);
4979 			if (udp->udp_ip_rcv_options)
4980 				udp->udp_ip_rcv_options_len = opt_len;
4981 		}
4982 		if (udp->udp_ip_rcv_options_len) {
4983 			bcopy(rptr + IP_SIMPLE_HDR_LENGTH,
4984 			    udp->udp_ip_rcv_options, opt_len);
4985 			/* Adjust length if we are resusing the space */
4986 			udp->udp_ip_rcv_options_len = opt_len;
4987 		}
4988 	} else if (udp->udp_ip_rcv_options_len) {
4989 		mi_free((char *)udp->udp_ip_rcv_options);
4990 		udp->udp_ip_rcv_options = NULL;
4991 		udp->udp_ip_rcv_options_len = 0;
4992 	}
4993 
4994 	/*
4995 	 * Normally only send up the address.
4996 	 * If IP_RECVDSTADDR is set we include the destination IP
4997 	 * address as an option. With IP_RECVOPTS we include all
4998 	 * the IP options.
4999 	 */
5000 	udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin_t);
5001 	if (udp->udp_recvdstaddr) {
5002 		udi_size += sizeof (struct T_opthdr) + sizeof (struct in_addr);
5003 		UDP_STAT(udp_in_recvdstaddr);
5004 	}
5005 	if (udp->udp_recvopts && opt_len > 0) {
5006 		udi_size += sizeof (struct T_opthdr) + opt_len;
5007 		UDP_STAT(udp_in_recvopts);
5008 	}
5009 
5010 	/*
5011 	 * If the IP_RECVSLLA or the IP_RECVIF is set then allocate
5012 	 * space accordingly
5013 	 */
5014 	if (udp->udp_recvif && recv_on &&
5015 	    (pinfo->in_pkt_flags & IPF_RECVIF)) {
5016 		udi_size += sizeof (struct T_opthdr) + sizeof (uint_t);
5017 		UDP_STAT(udp_in_recvif);
5018 	}
5019 
5020 	if (udp->udp_recvslla && recv_on &&
5021 	    (pinfo->in_pkt_flags & IPF_RECVSLLA)) {
5022 		udi_size += sizeof (struct T_opthdr) +
5023 		    sizeof (struct sockaddr_dl);
5024 		UDP_STAT(udp_in_recvslla);
5025 	}
5026 
5027 	if (udp->udp_recvucred && (cr = DB_CRED(mp)) != NULL) {
5028 		udi_size += sizeof (struct T_opthdr) + ucredsize;
5029 		cpid = DB_CPID(mp);
5030 		UDP_STAT(udp_in_recvucred);
5031 	}
5032 	/*
5033 	 * If IP_RECVTTL is set allocate the appropriate sized buffer
5034 	 */
5035 	if (udp->udp_recvttl) {
5036 		udi_size += sizeof (struct T_opthdr) + sizeof (uint8_t);
5037 		UDP_STAT(udp_in_recvttl);
5038 	}
5039 
5040 	/* Allocate a message block for the T_UNITDATA_IND structure. */
5041 	mp1 = allocb(udi_size, BPRI_MED);
5042 	if (mp1 == NULL) {
5043 		freemsg(mp);
5044 		if (options_mp != NULL)
5045 			freeb(options_mp);
5046 		TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
5047 			"udp_rput_other_end: q %p (%S)", q, "allocbfail");
5048 		BUMP_MIB(&udp_mib, udpInErrors);
5049 		return;
5050 	}
5051 	mp1->b_cont = mp;
5052 	mp = mp1;
5053 	mp->b_datap->db_type = M_PROTO;
5054 	tudi = (struct T_unitdata_ind *)mp->b_rptr;
5055 	mp->b_wptr = (uchar_t *)tudi + udi_size;
5056 	tudi->PRIM_type = T_UNITDATA_IND;
5057 	tudi->SRC_length = sizeof (sin_t);
5058 	tudi->SRC_offset = sizeof (struct T_unitdata_ind);
5059 	tudi->OPT_offset = sizeof (struct T_unitdata_ind) + sizeof (sin_t);
5060 	udi_size -= (sizeof (struct T_unitdata_ind) + sizeof (sin_t));
5061 	tudi->OPT_length = udi_size;
5062 
5063 	sin = (sin_t *)&tudi[1];
5064 	sin->sin_addr.s_addr = ((ipha_t *)rptr)->ipha_src;
5065 	sin->sin_port =	((in_port_t *)
5066 	    new_rptr)[-(UDPH_SIZE/sizeof (in_port_t))];
5067 	sin->sin_family = AF_INET;
5068 	*(uint32_t *)&sin->sin_zero[0] = 0;
5069 	*(uint32_t *)&sin->sin_zero[4] = 0;
5070 
5071 	/*
5072 	 * Add options if IP_RECVDSTADDR, IP_RECVIF, IP_RECVSLLA or
5073 	 * IP_RECVTTL has been set.
5074 	 */
5075 	if (udi_size != 0) {
5076 		/*
5077 		 * Copy in destination address before options to avoid any
5078 		 * padding issues.
5079 		 */
5080 		char *dstopt;
5081 
5082 		dstopt = (char *)&sin[1];
5083 		if (udp->udp_recvdstaddr) {
5084 			struct T_opthdr *toh;
5085 			ipaddr_t *dstptr;
5086 
5087 			toh = (struct T_opthdr *)dstopt;
5088 			toh->level = IPPROTO_IP;
5089 			toh->name = IP_RECVDSTADDR;
5090 			toh->len = sizeof (struct T_opthdr) + sizeof (ipaddr_t);
5091 			toh->status = 0;
5092 			dstopt += sizeof (struct T_opthdr);
5093 			dstptr = (ipaddr_t *)dstopt;
5094 			*dstptr = (((ipaddr_t *)rptr)[4]);
5095 			dstopt += sizeof (ipaddr_t);
5096 			udi_size -= toh->len;
5097 		}
5098 		if (udp->udp_recvopts && udi_size != 0) {
5099 			struct T_opthdr *toh;
5100 
5101 			toh = (struct T_opthdr *)dstopt;
5102 			toh->level = IPPROTO_IP;
5103 			toh->name = IP_RECVOPTS;
5104 			toh->len = sizeof (struct T_opthdr) + opt_len;
5105 			toh->status = 0;
5106 			dstopt += sizeof (struct T_opthdr);
5107 			bcopy(rptr + IP_SIMPLE_HDR_LENGTH, dstopt, opt_len);
5108 			dstopt += opt_len;
5109 			udi_size -= toh->len;
5110 		}
5111 
5112 		if (udp->udp_recvslla && recv_on &&
5113 		    (pinfo->in_pkt_flags & IPF_RECVSLLA)) {
5114 
5115 			struct T_opthdr *toh;
5116 			struct sockaddr_dl	*dstptr;
5117 
5118 			toh = (struct T_opthdr *)dstopt;
5119 			toh->level = IPPROTO_IP;
5120 			toh->name = IP_RECVSLLA;
5121 			toh->len = sizeof (struct T_opthdr) +
5122 			    sizeof (struct sockaddr_dl);
5123 			toh->status = 0;
5124 			dstopt += sizeof (struct T_opthdr);
5125 			dstptr = (struct sockaddr_dl *)dstopt;
5126 			bcopy(&pinfo->in_pkt_slla, dstptr,
5127 			    sizeof (struct sockaddr_dl));
5128 			dstopt += sizeof (struct sockaddr_dl);
5129 			udi_size -= toh->len;
5130 		}
5131 
5132 		if (udp->udp_recvif && recv_on &&
5133 		    (pinfo->in_pkt_flags & IPF_RECVIF)) {
5134 
5135 			struct T_opthdr *toh;
5136 			uint_t		*dstptr;
5137 
5138 			toh = (struct T_opthdr *)dstopt;
5139 			toh->level = IPPROTO_IP;
5140 			toh->name = IP_RECVIF;
5141 			toh->len = sizeof (struct T_opthdr) +
5142 			    sizeof (uint_t);
5143 			toh->status = 0;
5144 			dstopt += sizeof (struct T_opthdr);
5145 			dstptr = (uint_t *)dstopt;
5146 			*dstptr = pinfo->in_pkt_ifindex;
5147 			dstopt += sizeof (uint_t);
5148 			udi_size -= toh->len;
5149 		}
5150 
5151 		if (cr != NULL) {
5152 			struct T_opthdr *toh;
5153 
5154 			toh = (struct T_opthdr *)dstopt;
5155 			toh->level = SOL_SOCKET;
5156 			toh->name = SCM_UCRED;
5157 			toh->len = sizeof (struct T_opthdr) + ucredsize;
5158 			toh->status = 0;
5159 			(void) cred2ucred(cr, cpid, &toh[1]);
5160 			dstopt += toh->len;
5161 			udi_size -= toh->len;
5162 		}
5163 
5164 		if (udp->udp_recvttl) {
5165 			struct	T_opthdr *toh;
5166 			uint8_t	*dstptr;
5167 
5168 			toh = (struct T_opthdr *)dstopt;
5169 			toh->level = IPPROTO_IP;
5170 			toh->name = IP_RECVTTL;
5171 			toh->len = sizeof (struct T_opthdr) +
5172 			    sizeof (uint8_t);
5173 			toh->status = 0;
5174 			dstopt += sizeof (struct T_opthdr);
5175 			dstptr = (uint8_t *)dstopt;
5176 			*dstptr = ((ipha_t *)rptr)->ipha_ttl;
5177 			dstopt += sizeof (uint8_t);
5178 			udi_size -= toh->len;
5179 		}
5180 
5181 		ASSERT(udi_size == 0);	/* "Consumed" all of allocated space */
5182 	}
5183 	BUMP_MIB(&udp_mib, udpInDatagrams);
5184 	TRACE_2(TR_FAC_UDP, TR_UDP_RPUT_END,
5185 	    "udp_rput_other_end: q %p (%S)", q, "end");
5186 	if (options_mp != NULL)
5187 		freeb(options_mp);
5188 
5189 	if (udp->udp_direct_sockfs) {
5190 		/*
5191 		 * There is nothing above us except for the stream head;
5192 		 * use the read-side synchronous stream interface in
5193 		 * order to reduce the time spent in interrupt thread.
5194 		 */
5195 		ASSERT(udp->udp_issocket);
5196 		udp_rcv_enqueue(UDP_RD(q), udp, mp, msgdsize(mp));
5197 	} else {
5198 		/*
5199 		 * Use regular STREAMS interface to pass data upstream
5200 		 * if this is not a socket endpoint, or if we have
5201 		 * switched over to the slow mode due to sockmod being
5202 		 * popped or a module being pushed on top of us.
5203 		 */
5204 		putnext(UDP_RD(q), mp);
5205 	}
5206 }
5207 
5208 /* ARGSUSED */
5209 static void
5210 udp_rput_other_wrapper(void *arg, mblk_t *mp, void *arg2)
5211 {
5212 	conn_t *connp = arg;
5213 
5214 	udp_rput_other(connp->conn_rq, mp);
5215 	udp_exit(connp);
5216 }
5217 
5218 /*
5219  * Process a T_BIND_ACK
5220  */
5221 static void
5222 udp_rput_bind_ack(queue_t *q, mblk_t *mp)
5223 {
5224 	udp_t	*udp = Q_TO_UDP(q);
5225 	mblk_t	*mp1;
5226 	ire_t	*ire;
5227 	struct T_bind_ack *tba;
5228 	uchar_t *addrp;
5229 	ipa_conn_t	*ac;
5230 	ipa6_conn_t	*ac6;
5231 
5232 	if (udp->udp_discon_pending)
5233 		udp->udp_discon_pending = 0;
5234 
5235 	/*
5236 	 * If a broadcast/multicast address was bound set
5237 	 * the source address to 0.
5238 	 * This ensures no datagrams with broadcast address
5239 	 * as source address are emitted (which would violate
5240 	 * RFC1122 - Hosts requirements)
5241 	 *
5242 	 * Note that when connecting the returned IRE is
5243 	 * for the destination address and we only perform
5244 	 * the broadcast check for the source address (it
5245 	 * is OK to connect to a broadcast/multicast address.)
5246 	 */
5247 	mp1 = mp->b_cont;
5248 	if (mp1 != NULL && mp1->b_datap->db_type == IRE_DB_TYPE) {
5249 		ire = (ire_t *)mp1->b_rptr;
5250 
5251 		/*
5252 		 * Note: we get IRE_BROADCAST for IPv6 to "mark" a multicast
5253 		 * local address.
5254 		 */
5255 		if (ire->ire_type == IRE_BROADCAST &&
5256 		    udp->udp_state != TS_DATA_XFER) {
5257 			/* This was just a local bind to a broadcast addr */
5258 			V6_SET_ZERO(udp->udp_v6src);
5259 			if (udp->udp_family == AF_INET6)
5260 				(void) udp_build_hdrs(q, udp);
5261 		} else if (V6_OR_V4_INADDR_ANY(udp->udp_v6src)) {
5262 			/*
5263 			 * Local address not yet set - pick it from the
5264 			 * T_bind_ack
5265 			 */
5266 			tba = (struct T_bind_ack *)mp->b_rptr;
5267 			addrp = &mp->b_rptr[tba->ADDR_offset];
5268 			switch (udp->udp_family) {
5269 			case AF_INET:
5270 				if (tba->ADDR_length == sizeof (ipa_conn_t)) {
5271 					ac = (ipa_conn_t *)addrp;
5272 				} else {
5273 					ASSERT(tba->ADDR_length ==
5274 					    sizeof (ipa_conn_x_t));
5275 					ac = &((ipa_conn_x_t *)addrp)->acx_conn;
5276 				}
5277 				IN6_IPADDR_TO_V4MAPPED(ac->ac_laddr,
5278 				    &udp->udp_v6src);
5279 				break;
5280 			case AF_INET6:
5281 				if (tba->ADDR_length == sizeof (ipa6_conn_t)) {
5282 					ac6 = (ipa6_conn_t *)addrp;
5283 				} else {
5284 					ASSERT(tba->ADDR_length ==
5285 					    sizeof (ipa6_conn_x_t));
5286 					ac6 = &((ipa6_conn_x_t *)
5287 					    addrp)->ac6x_conn;
5288 				}
5289 				udp->udp_v6src = ac6->ac6_laddr;
5290 				(void) udp_build_hdrs(q, udp);
5291 				break;
5292 			}
5293 		}
5294 		mp1 = mp1->b_cont;
5295 	}
5296 	/*
5297 	 * Look for one or more appended ACK message added by
5298 	 * udp_connect or udp_disconnect.
5299 	 * If none found just send up the T_BIND_ACK.
5300 	 * udp_connect has appended a T_OK_ACK and a T_CONN_CON.
5301 	 * udp_disconnect has appended a T_OK_ACK.
5302 	 */
5303 	if (mp1 != NULL) {
5304 		if (mp->b_cont == mp1)
5305 			mp->b_cont = NULL;
5306 		else {
5307 			ASSERT(mp->b_cont->b_cont == mp1);
5308 			mp->b_cont->b_cont = NULL;
5309 		}
5310 		freemsg(mp);
5311 		mp = mp1;
5312 		while (mp != NULL) {
5313 			mp1 = mp->b_cont;
5314 			mp->b_cont = NULL;
5315 			putnext(UDP_RD(q), mp);
5316 			mp = mp1;
5317 		}
5318 		return;
5319 	}
5320 	freemsg(mp->b_cont);
5321 	mp->b_cont = NULL;
5322 	putnext(UDP_RD(q), mp);
5323 }
5324 
5325 /*
5326  * return SNMP stuff in buffer in mpdata
5327  */
5328 int
5329 udp_snmp_get(queue_t *q, mblk_t *mpctl)
5330 {
5331 	mblk_t			*mpdata;
5332 	mblk_t			*mp_conn_ctl;
5333 	mblk_t			*mp6_conn_ctl;
5334 	mblk_t			*mp_conn_data;
5335 	mblk_t			*mp6_conn_data;
5336 	mblk_t			*mp_conn_tail = NULL;
5337 	mblk_t			*mp6_conn_tail = NULL;
5338 	struct opthdr		*optp;
5339 	mib2_udpEntry_t		ude;
5340 	mib2_udp6Entry_t	ude6;
5341 	int			state;
5342 	zoneid_t		zoneid;
5343 	int			i;
5344 	connf_t			*connfp;
5345 	conn_t			*connp = Q_TO_CONN(q);
5346 	udp_t			*udp = connp->conn_udp;
5347 
5348 	if (mpctl == NULL ||
5349 	    (mpdata = mpctl->b_cont) == NULL ||
5350 	    (mp_conn_ctl = copymsg(mpctl)) == NULL ||
5351 	    (mp6_conn_ctl = copymsg(mpctl)) == NULL) {
5352 		freemsg(mp_conn_ctl);
5353 		return (0);
5354 	}
5355 
5356 	mp_conn_data = mp_conn_ctl->b_cont;
5357 	mp6_conn_data = mp6_conn_ctl->b_cont;
5358 
5359 	zoneid = connp->conn_zoneid;
5360 
5361 	/* fixed length structure for IPv4 and IPv6 counters */
5362 	SET_MIB(udp_mib.udpEntrySize, sizeof (mib2_udpEntry_t));
5363 	SET_MIB(udp_mib.udp6EntrySize, sizeof (mib2_udp6Entry_t));
5364 	optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
5365 	optp->level = MIB2_UDP;
5366 	optp->name = 0;
5367 	(void) snmp_append_data(mpdata, (char *)&udp_mib, sizeof (udp_mib));
5368 	optp->len = msgdsize(mpdata);
5369 	qreply(q, mpctl);
5370 
5371 	for (i = 0; i < CONN_G_HASH_SIZE; i++) {
5372 		connfp = &ipcl_globalhash_fanout[i];
5373 		connp = NULL;
5374 
5375 		while ((connp = ipcl_get_next_conn(connfp, connp,
5376 		    IPCL_UDP))) {
5377 			udp = connp->conn_udp;
5378 			if (zoneid != connp->conn_zoneid)
5379 				continue;
5380 
5381 			/*
5382 			 * Note that the port numbers are sent in
5383 			 * host byte order
5384 			 */
5385 
5386 			if (udp->udp_state == TS_UNBND)
5387 				state = MIB2_UDP_unbound;
5388 			else if (udp->udp_state == TS_IDLE)
5389 				state = MIB2_UDP_idle;
5390 			else if (udp->udp_state == TS_DATA_XFER)
5391 				state = MIB2_UDP_connected;
5392 			else
5393 				state = MIB2_UDP_unknown;
5394 
5395 			/*
5396 			 * Create an IPv4 table entry for IPv4 entries and also
5397 			 * any IPv6 entries which are bound to in6addr_any
5398 			 * (i.e. anything a IPv4 peer could connect/send to).
5399 			 */
5400 			if (udp->udp_ipversion == IPV4_VERSION ||
5401 			    (udp->udp_state <= TS_IDLE &&
5402 			    IN6_IS_ADDR_UNSPECIFIED(&udp->udp_v6src))) {
5403 				ude.udpEntryInfo.ue_state = state;
5404 				/*
5405 				 * If in6addr_any this will set it to
5406 				 * INADDR_ANY
5407 				 */
5408 				ude.udpLocalAddress =
5409 				    V4_PART_OF_V6(udp->udp_v6src);
5410 				ude.udpLocalPort = ntohs(udp->udp_port);
5411 				if (udp->udp_state == TS_DATA_XFER) {
5412 					/*
5413 					 * Can potentially get here for
5414 					 * v6 socket if another process
5415 					 * (say, ping) has just done a
5416 					 * sendto(), changing the state
5417 					 * from the TS_IDLE above to
5418 					 * TS_DATA_XFER by the time we hit
5419 					 * this part of the code.
5420 					 */
5421 					ude.udpEntryInfo.ue_RemoteAddress =
5422 					    V4_PART_OF_V6(udp->udp_v6dst);
5423 					ude.udpEntryInfo.ue_RemotePort =
5424 					    ntohs(udp->udp_dstport);
5425 				} else {
5426 					ude.udpEntryInfo.ue_RemoteAddress = 0;
5427 					ude.udpEntryInfo.ue_RemotePort = 0;
5428 				}
5429 				(void) snmp_append_data2(mp_conn_data,
5430 				    &mp_conn_tail, (char *)&ude, sizeof (ude));
5431 			}
5432 			if (udp->udp_ipversion == IPV6_VERSION) {
5433 				ude6.udp6EntryInfo.ue_state  = state;
5434 				ude6.udp6LocalAddress = udp->udp_v6src;
5435 				ude6.udp6LocalPort = ntohs(udp->udp_port);
5436 				ude6.udp6IfIndex = udp->udp_bound_if;
5437 				if (udp->udp_state == TS_DATA_XFER) {
5438 					ude6.udp6EntryInfo.ue_RemoteAddress =
5439 					    udp->udp_v6dst;
5440 					ude6.udp6EntryInfo.ue_RemotePort =
5441 					    ntohs(udp->udp_dstport);
5442 				} else {
5443 					ude6.udp6EntryInfo.ue_RemoteAddress =
5444 					    sin6_null.sin6_addr;
5445 					ude6.udp6EntryInfo.ue_RemotePort = 0;
5446 				}
5447 				(void) snmp_append_data2(mp6_conn_data,
5448 				    &mp6_conn_tail, (char *)&ude6,
5449 				    sizeof (ude6));
5450 			}
5451 		}
5452 	}
5453 
5454 	/* IPv4 UDP endpoints */
5455 	optp = (struct opthdr *)&mp_conn_ctl->b_rptr[
5456 	    sizeof (struct T_optmgmt_ack)];
5457 	optp->level = MIB2_UDP;
5458 	optp->name = MIB2_UDP_ENTRY;
5459 	optp->len = msgdsize(mp_conn_data);
5460 	qreply(q, mp_conn_ctl);
5461 
5462 	/* IPv6 UDP endpoints */
5463 	optp = (struct opthdr *)&mp6_conn_ctl->b_rptr[
5464 	    sizeof (struct T_optmgmt_ack)];
5465 	optp->level = MIB2_UDP6;
5466 	optp->name = MIB2_UDP6_ENTRY;
5467 	optp->len = msgdsize(mp6_conn_data);
5468 	qreply(q, mp6_conn_ctl);
5469 
5470 	return (1);
5471 }
5472 
5473 /*
5474  * Return 0 if invalid set request, 1 otherwise, including non-udp requests.
5475  * NOTE: Per MIB-II, UDP has no writable data.
5476  * TODO:  If this ever actually tries to set anything, it needs to be
5477  * to do the appropriate locking.
5478  */
5479 /* ARGSUSED */
5480 int
5481 udp_snmp_set(queue_t *q, t_scalar_t level, t_scalar_t name,
5482     uchar_t *ptr, int len)
5483 {
5484 	switch (level) {
5485 	case MIB2_UDP:
5486 		return (0);
5487 	default:
5488 		return (1);
5489 	}
5490 }
5491 
5492 static void
5493 udp_report_item(mblk_t *mp, udp_t *udp)
5494 {
5495 	char *state;
5496 	char addrbuf1[INET6_ADDRSTRLEN];
5497 	char addrbuf2[INET6_ADDRSTRLEN];
5498 	uint_t print_len, buf_len;
5499 
5500 	buf_len = mp->b_datap->db_lim - mp->b_wptr;
5501 	ASSERT(buf_len >= 0);
5502 	if (buf_len == 0)
5503 		return;
5504 
5505 	if (udp->udp_state == TS_UNBND)
5506 		state = "UNBOUND";
5507 	else if (udp->udp_state == TS_IDLE)
5508 		state = "IDLE";
5509 	else if (udp->udp_state == TS_DATA_XFER)
5510 		state = "CONNECTED";
5511 	else
5512 		state = "UnkState";
5513 	print_len = snprintf((char *)mp->b_wptr, buf_len,
5514 	    MI_COL_PTRFMT_STR "%4d %5u %s %s %5u %s\n",
5515 	    (void *)udp, udp->udp_connp->conn_zoneid, ntohs(udp->udp_port),
5516 	    inet_ntop(AF_INET6, &udp->udp_v6src,
5517 		addrbuf1, sizeof (addrbuf1)),
5518 	    inet_ntop(AF_INET6, &udp->udp_v6dst,
5519 		addrbuf2, sizeof (addrbuf2)),
5520 	    ntohs(udp->udp_dstport), state);
5521 	if (print_len < buf_len) {
5522 		mp->b_wptr += print_len;
5523 	} else {
5524 		mp->b_wptr += buf_len;
5525 	}
5526 }
5527 
5528 /* Report for ndd "udp_status" */
5529 /* ARGSUSED */
5530 static int
5531 udp_status_report(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr)
5532 {
5533 	zoneid_t zoneid;
5534 	connf_t	*connfp;
5535 	conn_t	*connp = Q_TO_CONN(q);
5536 	udp_t	*udp = connp->conn_udp;
5537 	int	i;
5538 
5539 	/*
5540 	 * Because of the ndd constraint, at most we can have 64K buffer
5541 	 * to put in all UDP info.  So to be more efficient, just
5542 	 * allocate a 64K buffer here, assuming we need that large buffer.
5543 	 * This may be a problem as any user can read udp_status.  Therefore
5544 	 * we limit the rate of doing this using udp_ndd_get_info_interval.
5545 	 * This should be OK as normal users should not do this too often.
5546 	 */
5547 	if (cr == NULL || secpolicy_net_config(cr, B_TRUE) != 0) {
5548 		if (ddi_get_lbolt() - udp_last_ndd_get_info_time <
5549 		    drv_usectohz(udp_ndd_get_info_interval * 1000)) {
5550 			(void) mi_mpprintf(mp, NDD_TOO_QUICK_MSG);
5551 			return (0);
5552 		}
5553 	}
5554 	if ((mp->b_cont = allocb(ND_MAX_BUF_LEN, BPRI_HI)) == NULL) {
5555 		/* The following may work even if we cannot get a large buf. */
5556 		(void) mi_mpprintf(mp, NDD_OUT_OF_BUF_MSG);
5557 		return (0);
5558 	}
5559 	(void) mi_mpprintf(mp,
5560 	    "UDP     " MI_COL_HDRPAD_STR
5561 	/*   12345678[89ABCDEF] */
5562 	    " zone lport src addr        dest addr       port  state");
5563 	/*    1234 12345 xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx 12345 UNBOUND */
5564 
5565 	zoneid = connp->conn_zoneid;
5566 
5567 	for (i = 0; i < CONN_G_HASH_SIZE; i++) {
5568 		connfp = &ipcl_globalhash_fanout[i];
5569 		connp = NULL;
5570 
5571 		while ((connp = ipcl_get_next_conn(connfp, connp,
5572 		    IPCL_UDP))) {
5573 			udp = connp->conn_udp;
5574 			if (zoneid != GLOBAL_ZONEID &&
5575 			    zoneid != connp->conn_zoneid)
5576 				continue;
5577 
5578 			udp_report_item(mp->b_cont, udp);
5579 		}
5580 	}
5581 	udp_last_ndd_get_info_time = ddi_get_lbolt();
5582 	return (0);
5583 }
5584 
5585 /*
5586  * This routine creates a T_UDERROR_IND message and passes it upstream.
5587  * The address and options are copied from the T_UNITDATA_REQ message
5588  * passed in mp.  This message is freed.
5589  */
5590 static void
5591 udp_ud_err(queue_t *q, mblk_t *mp, uchar_t *destaddr, t_scalar_t destlen,
5592     t_scalar_t err)
5593 {
5594 	struct T_unitdata_req *tudr;
5595 	mblk_t	*mp1;
5596 	uchar_t	*optaddr;
5597 	t_scalar_t optlen;
5598 
5599 	if (DB_TYPE(mp) == M_DATA) {
5600 		ASSERT(destaddr != NULL && destlen != 0);
5601 		optaddr = NULL;
5602 		optlen = 0;
5603 	} else {
5604 		if ((mp->b_wptr < mp->b_rptr) ||
5605 		    (MBLKL(mp)) < sizeof (struct T_unitdata_req)) {
5606 			goto done;
5607 		}
5608 		tudr = (struct T_unitdata_req *)mp->b_rptr;
5609 		destaddr = mp->b_rptr + tudr->DEST_offset;
5610 		if (destaddr < mp->b_rptr || destaddr >= mp->b_wptr ||
5611 		    destaddr + tudr->DEST_length < mp->b_rptr ||
5612 		    destaddr + tudr->DEST_length > mp->b_wptr) {
5613 			goto done;
5614 		}
5615 		optaddr = mp->b_rptr + tudr->OPT_offset;
5616 		if (optaddr < mp->b_rptr || optaddr >= mp->b_wptr ||
5617 		    optaddr + tudr->OPT_length < mp->b_rptr ||
5618 		    optaddr + tudr->OPT_length > mp->b_wptr) {
5619 			goto done;
5620 		}
5621 		destlen = tudr->DEST_length;
5622 		optlen = tudr->OPT_length;
5623 	}
5624 
5625 	mp1 = mi_tpi_uderror_ind((char *)destaddr, destlen,
5626 	    (char *)optaddr, optlen, err);
5627 	if (mp1 != NULL)
5628 		putnext(UDP_RD(q), mp1);
5629 
5630 done:
5631 	freemsg(mp);
5632 }
5633 
5634 /*
5635  * This routine removes a port number association from a stream.  It
5636  * is called by udp_wput to handle T_UNBIND_REQ messages.
5637  */
5638 static void
5639 udp_unbind(queue_t *q, mblk_t *mp)
5640 {
5641 	udp_t *udp = Q_TO_UDP(q);
5642 
5643 	/* If a bind has not been done, we can't unbind. */
5644 	if (udp->udp_state == TS_UNBND) {
5645 		udp_err_ack(q, mp, TOUTSTATE, 0);
5646 		return;
5647 	}
5648 	if (cl_inet_unbind != NULL) {
5649 		/*
5650 		 * Running in cluster mode - register unbind information
5651 		 */
5652 		if (udp->udp_ipversion == IPV4_VERSION) {
5653 			(*cl_inet_unbind)(IPPROTO_UDP, AF_INET,
5654 			    (uint8_t *)(&V4_PART_OF_V6(udp->udp_v6src)),
5655 			    (in_port_t)udp->udp_port);
5656 		} else {
5657 			(*cl_inet_unbind)(IPPROTO_UDP, AF_INET6,
5658 			    (uint8_t *)&(udp->udp_v6src),
5659 			    (in_port_t)udp->udp_port);
5660 		}
5661 	}
5662 
5663 	udp_bind_hash_remove(udp, B_FALSE);
5664 	V6_SET_ZERO(udp->udp_v6src);
5665 	V6_SET_ZERO(udp->udp_bound_v6src);
5666 	udp->udp_port = 0;
5667 	udp->udp_state = TS_UNBND;
5668 
5669 	if (udp->udp_family == AF_INET6) {
5670 		int error;
5671 
5672 		/* Rebuild the header template */
5673 		error = udp_build_hdrs(q, udp);
5674 		if (error != 0) {
5675 			udp_err_ack(q, mp, TSYSERR, error);
5676 			return;
5677 		}
5678 	}
5679 	/*
5680 	 * Pass the unbind to IP; T_UNBIND_REQ is larger than T_OK_ACK
5681 	 * and therefore ip_unbind must never return NULL.
5682 	 */
5683 	mp = ip_unbind(q, mp);
5684 	ASSERT(mp != NULL);
5685 	putnext(UDP_RD(q), mp);
5686 }
5687 
5688 /*
5689  * Don't let port fall into the privileged range.
5690  * Since the extra priviledged ports can be arbitrary we also
5691  * ensure that we exclude those from consideration.
5692  * udp_g_epriv_ports is not sorted thus we loop over it until
5693  * there are no changes.
5694  */
5695 static in_port_t
5696 udp_update_next_port(in_port_t port, boolean_t random)
5697 {
5698 	int i;
5699 
5700 	if (random && udp_random_anon_port != 0) {
5701 		(void) random_get_pseudo_bytes((uint8_t *)&port,
5702 		    sizeof (in_port_t));
5703 		/*
5704 		 * Unless changed by a sys admin, the smallest anon port
5705 		 * is 32768 and the largest anon port is 65535.  It is
5706 		 * very likely (50%) for the random port to be smaller
5707 		 * than the smallest anon port.  When that happens,
5708 		 * add port % (anon port range) to the smallest anon
5709 		 * port to get the random port.  It should fall into the
5710 		 * valid anon port range.
5711 		 */
5712 		if (port < udp_smallest_anon_port) {
5713 			port = udp_smallest_anon_port +
5714 			    port % (udp_largest_anon_port -
5715 			    udp_smallest_anon_port);
5716 		}
5717 	}
5718 
5719 retry:
5720 	if (port < udp_smallest_anon_port || port > udp_largest_anon_port)
5721 		port = udp_smallest_anon_port;
5722 
5723 	if (port < udp_smallest_nonpriv_port)
5724 		port = udp_smallest_nonpriv_port;
5725 
5726 	for (i = 0; i < udp_g_num_epriv_ports; i++) {
5727 		if (port == udp_g_epriv_ports[i]) {
5728 			port++;
5729 			/*
5730 			 * Make sure that the port is in the
5731 			 * valid range.
5732 			 */
5733 			goto retry;
5734 		}
5735 	}
5736 	return (port);
5737 }
5738 
5739 static mblk_t *
5740 udp_output_v4(conn_t *connp, mblk_t *mp, ipaddr_t v4dst, uint16_t port,
5741     uint_t srcid, int *error)
5742 {
5743 	udp_t	*udp = connp->conn_udp;
5744 	queue_t	*q = connp->conn_wq;
5745 	mblk_t	*mp1 = (DB_TYPE(mp) == M_DATA ? mp : mp->b_cont);
5746 	mblk_t	*mp2;
5747 	ipha_t	*ipha;
5748 	int	ip_hdr_length;
5749 	uint32_t ip_len;
5750 	udpha_t	*udpha;
5751 
5752 	*error = 0;
5753 
5754 	/* mp1 points to the M_DATA mblk carrying the packet */
5755 	ASSERT(mp1 != NULL && DB_TYPE(mp1) == M_DATA);
5756 
5757 	/* Add an IP header */
5758 	ip_hdr_length = IP_SIMPLE_HDR_LENGTH + UDPH_SIZE +
5759 	    udp->udp_ip_snd_options_len;
5760 	ipha = (ipha_t *)&mp1->b_rptr[-ip_hdr_length];
5761 	if (DB_REF(mp1) != 1 || (uchar_t *)ipha < DB_BASE(mp1) ||
5762 	    !OK_32PTR(ipha)) {
5763 		mp2 = allocb(ip_hdr_length + udp_wroff_extra, BPRI_LO);
5764 		if (mp2 == NULL) {
5765 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
5766 			    "udp_wput_end: q %p (%S)", q, "allocbfail2");
5767 			*error = ENOMEM;
5768 			goto done;
5769 		}
5770 		mp2->b_wptr = DB_LIM(mp2);
5771 		mp2->b_cont = mp1;
5772 		mp1 = mp2;
5773 		if (DB_TYPE(mp) != M_DATA)
5774 			mp->b_cont = mp1;
5775 		else
5776 			mp = mp1;
5777 
5778 		ipha = (ipha_t *)(mp1->b_wptr - ip_hdr_length);
5779 	}
5780 	ip_hdr_length -= UDPH_SIZE;
5781 #ifdef	_BIG_ENDIAN
5782 	/* Set version, header length, and tos */
5783 	*(uint16_t *)&ipha->ipha_version_and_hdr_length =
5784 	    ((((IP_VERSION << 4) | (ip_hdr_length>>2)) << 8) |
5785 		udp->udp_type_of_service);
5786 	/* Set ttl and protocol */
5787 	*(uint16_t *)&ipha->ipha_ttl = (udp->udp_ttl << 8) | IPPROTO_UDP;
5788 #else
5789 	/* Set version, header length, and tos */
5790 	*(uint16_t *)&ipha->ipha_version_and_hdr_length =
5791 		((udp->udp_type_of_service << 8) |
5792 		    ((IP_VERSION << 4) | (ip_hdr_length>>2)));
5793 	/* Set ttl and protocol */
5794 	*(uint16_t *)&ipha->ipha_ttl = (IPPROTO_UDP << 8) | udp->udp_ttl;
5795 #endif
5796 	/*
5797 	 * Copy our address into the packet.  If this is zero,
5798 	 * first look at __sin6_src_id for a hint. If we leave the source
5799 	 * as INADDR_ANY then ip will fill in the real source address.
5800 	 */
5801 	IN6_V4MAPPED_TO_IPADDR(&udp->udp_v6src, ipha->ipha_src);
5802 	if (srcid != 0 && ipha->ipha_src == INADDR_ANY) {
5803 		in6_addr_t v6src;
5804 
5805 		ip_srcid_find_id(srcid, &v6src, connp->conn_zoneid);
5806 		IN6_V4MAPPED_TO_IPADDR(&v6src, ipha->ipha_src);
5807 	}
5808 
5809 	ipha->ipha_fragment_offset_and_flags = 0;
5810 	ipha->ipha_ident = 0;
5811 
5812 	mp1->b_rptr = (uchar_t *)ipha;
5813 
5814 	ASSERT((uintptr_t)(mp1->b_wptr - (uchar_t *)ipha) <=
5815 	    (uintptr_t)UINT_MAX);
5816 
5817 	/* Determine length of packet */
5818 	ip_len = (uint32_t)(mp1->b_wptr - (uchar_t *)ipha);
5819 	if ((mp2 = mp1->b_cont) != NULL) {
5820 		do {
5821 			ASSERT((uintptr_t)MBLKL(mp2) <= (uintptr_t)UINT_MAX);
5822 			ip_len += (uint32_t)MBLKL(mp2);
5823 		} while ((mp2 = mp2->b_cont) != NULL);
5824 	}
5825 	/*
5826 	 * If the size of the packet is greater than the maximum allowed by
5827 	 * ip, return an error. Passing this down could cause panics because
5828 	 * the size will have wrapped and be inconsistent with the msg size.
5829 	 */
5830 	if (ip_len > IP_MAXPACKET) {
5831 		TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
5832 		    "udp_wput_end: q %p (%S)", q, "IP length exceeded");
5833 		*error = EMSGSIZE;
5834 		goto done;
5835 	}
5836 	ipha->ipha_length = htons((uint16_t)ip_len);
5837 	ip_len -= ip_hdr_length;
5838 	ip_len = htons((uint16_t)ip_len);
5839 	udpha = (udpha_t *)(((uchar_t *)ipha) + ip_hdr_length);
5840 
5841 	/*
5842 	 * Copy in the destination address
5843 	 */
5844 	if (v4dst == INADDR_ANY)
5845 		ipha->ipha_dst = htonl(INADDR_LOOPBACK);
5846 	else
5847 		ipha->ipha_dst = v4dst;
5848 
5849 	/*
5850 	 * Set ttl based on IP_MULTICAST_TTL to match IPv6 logic.
5851 	 */
5852 	if (CLASSD(v4dst))
5853 		ipha->ipha_ttl = udp->udp_multicast_ttl;
5854 
5855 	udpha->uha_dst_port = port;
5856 	udpha->uha_src_port = udp->udp_port;
5857 
5858 	if (ip_hdr_length > IP_SIMPLE_HDR_LENGTH) {
5859 		uint32_t	cksum;
5860 
5861 		bcopy(udp->udp_ip_snd_options, &ipha[1],
5862 		    udp->udp_ip_snd_options_len);
5863 		/*
5864 		 * Massage source route putting first source route in ipha_dst.
5865 		 * Ignore the destination in T_unitdata_req.
5866 		 * Create a checksum adjustment for a source route, if any.
5867 		 */
5868 		cksum = ip_massage_options(ipha);
5869 		cksum = (cksum & 0xFFFF) + (cksum >> 16);
5870 		cksum -= ((ipha->ipha_dst >> 16) & 0xFFFF) +
5871 		    (ipha->ipha_dst & 0xFFFF);
5872 		if ((int)cksum < 0)
5873 			cksum--;
5874 		cksum = (cksum & 0xFFFF) + (cksum >> 16);
5875 		/*
5876 		 * IP does the checksum if uha_checksum is non-zero,
5877 		 * We make it easy for IP to include our pseudo header
5878 		 * by putting our length in uha_checksum.
5879 		 */
5880 		cksum += ip_len;
5881 		cksum = (cksum & 0xFFFF) + (cksum >> 16);
5882 		/* There might be a carry. */
5883 		cksum = (cksum & 0xFFFF) + (cksum >> 16);
5884 #ifdef _LITTLE_ENDIAN
5885 		if (udp_do_checksum)
5886 			ip_len = (cksum << 16) | ip_len;
5887 #else
5888 		if (udp_do_checksum)
5889 			ip_len = (ip_len << 16) | cksum;
5890 		else
5891 			ip_len <<= 16;
5892 #endif
5893 	} else {
5894 		/*
5895 		 * IP does the checksum if uha_checksum is non-zero,
5896 		 * We make it easy for IP to include our pseudo header
5897 		 * by putting our length in uha_checksum.
5898 		 */
5899 		if (udp_do_checksum)
5900 			ip_len |= (ip_len << 16);
5901 #ifndef _LITTLE_ENDIAN
5902 		else
5903 			ip_len <<= 16;
5904 #endif
5905 	}
5906 	/* Set UDP length and checksum */
5907 	*((uint32_t *)&udpha->uha_length) = ip_len;
5908 
5909 	if (DB_TYPE(mp) != M_DATA) {
5910 		ASSERT(mp != mp1);
5911 		freeb(mp);
5912 	}
5913 
5914 	/* mp has been consumed and we'll return success */
5915 	ASSERT(*error == 0);
5916 	mp = NULL;
5917 
5918 	/* We're done.  Pass the packet to ip. */
5919 	BUMP_MIB(&udp_mib, udpOutDatagrams);
5920 	TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
5921 		"udp_wput_end: q %p (%S)", q, "end");
5922 
5923 	if ((connp->conn_flags & IPCL_CHECK_POLICY) != 0 ||
5924 	    CONN_OUTBOUND_POLICY_PRESENT(connp) ||
5925 	    connp->conn_dontroute || connp->conn_xmit_if_ill != NULL ||
5926 	    connp->conn_nofailover_ill != NULL ||
5927 	    connp->conn_outgoing_ill != NULL ||
5928 	    ipha->ipha_version_and_hdr_length != IP_SIMPLE_HDR_VERSION ||
5929 	    IPP_ENABLED(IPP_LOCAL_OUT) || ip_g_mrouter != NULL) {
5930 		UDP_STAT(udp_ip_send);
5931 		ip_output(connp, mp1, connp->conn_wq, IP_WPUT);
5932 	} else {
5933 		udp_send_data(udp, connp->conn_wq, mp1, ipha);
5934 	}
5935 
5936 done:
5937 	if (*error != 0) {
5938 		ASSERT(mp != NULL);
5939 		BUMP_MIB(&udp_mib, udpOutErrors);
5940 	}
5941 	return (mp);
5942 }
5943 
5944 static void
5945 udp_send_data(udp_t *udp, queue_t *q, mblk_t *mp, ipha_t *ipha)
5946 {
5947 	conn_t	*connp = udp->udp_connp;
5948 	ipaddr_t src, dst;
5949 	ill_t	*ill;
5950 	ire_t	*ire;
5951 	ipif_t	*ipif = NULL;
5952 	mblk_t	*ire_fp_mp;
5953 	uint_t	ire_fp_mp_len;
5954 	uint16_t *up;
5955 	uint32_t cksum, hcksum_txflags;
5956 	queue_t	*dev_q;
5957 	boolean_t retry_caching;
5958 
5959 	dst = ipha->ipha_dst;
5960 	src = ipha->ipha_src;
5961 	ASSERT(ipha->ipha_ident == 0);
5962 
5963 	if (CLASSD(dst)) {
5964 		int err;
5965 
5966 		ipif = conn_get_held_ipif(connp,
5967 		    &connp->conn_multicast_ipif, &err);
5968 
5969 		if (ipif == NULL || ipif->ipif_isv6 ||
5970 		    (ipif->ipif_ill->ill_phyint->phyint_flags &
5971 		    PHYI_LOOPBACK)) {
5972 			if (ipif != NULL)
5973 				ipif_refrele(ipif);
5974 			UDP_STAT(udp_ip_send);
5975 			ip_output(connp, mp, q, IP_WPUT);
5976 			return;
5977 		}
5978 	}
5979 
5980 	retry_caching = B_FALSE;
5981 	mutex_enter(&connp->conn_lock);
5982 	ire = connp->conn_ire_cache;
5983 	ASSERT(!(connp->conn_state_flags & CONN_INCIPIENT));
5984 
5985 	if (ire == NULL || ire->ire_addr != dst ||
5986 	    (ire->ire_marks & IRE_MARK_CONDEMNED)) {
5987 		retry_caching = B_TRUE;
5988 	} else if (CLASSD(dst) && (ire->ire_type & IRE_CACHE)) {
5989 		ill_t *stq_ill = (ill_t *)ire->ire_stq->q_ptr;
5990 
5991 		ASSERT(ipif != NULL);
5992 		if (stq_ill != ipif->ipif_ill && (stq_ill->ill_group == NULL ||
5993 		    stq_ill->ill_group != ipif->ipif_ill->ill_group))
5994 			retry_caching = B_TRUE;
5995 	}
5996 
5997 	if (!retry_caching) {
5998 		ASSERT(ire != NULL);
5999 		IRE_REFHOLD(ire);
6000 		mutex_exit(&connp->conn_lock);
6001 	} else {
6002 		boolean_t cached = B_FALSE;
6003 
6004 		connp->conn_ire_cache = NULL;
6005 		mutex_exit(&connp->conn_lock);
6006 
6007 		/* Release the old ire */
6008 		if (ire != NULL) {
6009 			IRE_REFRELE_NOTR(ire);
6010 			ire = NULL;
6011 		}
6012 
6013 		if (CLASSD(dst)) {
6014 			ASSERT(ipif != NULL);
6015 			ire = ire_ctable_lookup(dst, 0, 0, ipif,
6016 			    connp->conn_zoneid, MATCH_IRE_ILL_GROUP);
6017 		} else {
6018 			ASSERT(ipif == NULL);
6019 			ire = ire_cache_lookup(dst, connp->conn_zoneid);
6020 		}
6021 
6022 		if (ire == NULL) {
6023 			if (ipif != NULL)
6024 				ipif_refrele(ipif);
6025 			UDP_STAT(udp_ire_null);
6026 			ip_output(connp, mp, q, IP_WPUT);
6027 			return;
6028 		}
6029 		IRE_REFHOLD_NOTR(ire);
6030 
6031 		mutex_enter(&connp->conn_lock);
6032 		if (!(connp->conn_state_flags & CONN_CLOSING) &&
6033 		    connp->conn_ire_cache == NULL) {
6034 			rw_enter(&ire->ire_bucket->irb_lock, RW_READER);
6035 			if (!(ire->ire_marks & IRE_MARK_CONDEMNED)) {
6036 				connp->conn_ire_cache = ire;
6037 				cached = B_TRUE;
6038 			}
6039 			rw_exit(&ire->ire_bucket->irb_lock);
6040 		}
6041 		mutex_exit(&connp->conn_lock);
6042 
6043 		/*
6044 		 * We can continue to use the ire but since it was not
6045 		 * cached, we should drop the extra reference.
6046 		 */
6047 		if (!cached)
6048 			IRE_REFRELE_NOTR(ire);
6049 	}
6050 	ASSERT(ire != NULL && ire->ire_ipversion == IPV4_VERSION);
6051 	ASSERT(!CLASSD(dst) || ipif != NULL);
6052 
6053 	if ((ire->ire_type & (IRE_BROADCAST|IRE_LOCAL|IRE_LOOPBACK)) ||
6054 	    (ire->ire_flags & RTF_MULTIRT) || ire->ire_stq == NULL ||
6055 	    ire->ire_max_frag < ntohs(ipha->ipha_length) ||
6056 	    (ire_fp_mp = ire->ire_fp_mp) == NULL ||
6057 	    (ire_fp_mp_len = MBLKL(ire_fp_mp)) > MBLKHEAD(mp)) {
6058 		if (ipif != NULL)
6059 			ipif_refrele(ipif);
6060 		UDP_STAT(udp_ip_ire_send);
6061 		IRE_REFRELE(ire);
6062 		ip_output(connp, mp, q, IP_WPUT);
6063 		return;
6064 	}
6065 
6066 	BUMP_MIB(&ip_mib, ipOutRequests);
6067 
6068 	ill = ire_to_ill(ire);
6069 	ASSERT(ill != NULL);
6070 
6071 	dev_q = ire->ire_stq->q_next;
6072 	ASSERT(dev_q != NULL);
6073 	/*
6074 	 * If the service thread is already running, or if the driver
6075 	 * queue is currently flow-controlled, queue this packet.
6076 	 */
6077 	if ((q->q_first != NULL || connp->conn_draining) ||
6078 	    ((dev_q->q_next || dev_q->q_first) && !canput(dev_q))) {
6079 		if (ip_output_queue) {
6080 			(void) putq(q, mp);
6081 		} else {
6082 			BUMP_MIB(&ip_mib, ipOutDiscards);
6083 			freemsg(mp);
6084 		}
6085 		if (ipif != NULL)
6086 			ipif_refrele(ipif);
6087 		IRE_REFRELE(ire);
6088 		return;
6089 	}
6090 
6091 	ipha->ipha_ident = (uint16_t)atomic_add_32_nv(&ire->ire_ident, 1);
6092 #ifndef _BIG_ENDIAN
6093 	ipha->ipha_ident = (ipha->ipha_ident << 8) | (ipha->ipha_ident >> 8);
6094 #endif
6095 
6096 	if (src == INADDR_ANY && !connp->conn_unspec_src) {
6097 		if (CLASSD(dst) && !(ire->ire_flags & RTF_SETSRC))
6098 			src = ipha->ipha_src = ipif->ipif_src_addr;
6099 		else
6100 			src = ipha->ipha_src = ire->ire_src_addr;
6101 	}
6102 
6103 	if (ILL_HCKSUM_CAPABLE(ill) && dohwcksum) {
6104 		ASSERT(ill->ill_hcksum_capab != NULL);
6105 		hcksum_txflags = ill->ill_hcksum_capab->ill_hcksum_txflags;
6106 	} else {
6107 		hcksum_txflags = 0;
6108 	}
6109 
6110 	/* pseudo-header checksum (do it in parts for IP header checksum) */
6111 	cksum = (dst >> 16) + (dst & 0xFFFF) + (src >> 16) + (src & 0xFFFF);
6112 
6113 	ASSERT(ipha->ipha_version_and_hdr_length == IP_SIMPLE_HDR_VERSION);
6114 	up = IPH_UDPH_CHECKSUMP(ipha, IP_SIMPLE_HDR_LENGTH);
6115 	if (*up != 0) {
6116 		IP_CKSUM_XMIT_FAST(ire->ire_ipversion, hcksum_txflags,
6117 		    mp, ipha, up, IPPROTO_UDP, IP_SIMPLE_HDR_LENGTH,
6118 		    ntohs(ipha->ipha_length), cksum);
6119 
6120 		/* Software checksum? */
6121 		if (DB_CKSUMFLAGS(mp) == 0) {
6122 			UDP_STAT(udp_out_sw_cksum);
6123 			UDP_STAT_UPDATE(udp_out_sw_cksum_bytes,
6124 			    ntohs(ipha->ipha_length) - IP_SIMPLE_HDR_LENGTH);
6125 		}
6126 	}
6127 
6128 	ipha->ipha_fragment_offset_and_flags |=
6129 	    (uint32_t)htons(ire->ire_frag_flag);
6130 
6131 	/* Calculate IP header checksum if hardware isn't capable */
6132 	if (!(DB_CKSUMFLAGS(mp) & HCK_IPV4_HDRCKSUM)) {
6133 		IP_HDR_CKSUM(ipha, cksum, ((uint32_t *)ipha)[0],
6134 		    ((uint16_t *)ipha)[4]);
6135 	}
6136 
6137 	if (CLASSD(dst)) {
6138 		ilm_t *ilm;
6139 
6140 		ILM_WALKER_HOLD(ill);
6141 		ilm = ilm_lookup_ill(ill, dst, ALL_ZONES);
6142 		ILM_WALKER_RELE(ill);
6143 		if (ilm != NULL) {
6144 			ip_multicast_loopback(q, ill, mp,
6145 			    connp->conn_multicast_loop ? 0 :
6146 			    IP_FF_NO_MCAST_LOOP, connp->conn_zoneid);
6147 		}
6148 
6149 		/* If multicast TTL is 0 then we are done */
6150 		if (ipha->ipha_ttl == 0) {
6151 			if (ipif != NULL)
6152 				ipif_refrele(ipif);
6153 			freemsg(mp);
6154 			IRE_REFRELE(ire);
6155 			return;
6156 		}
6157 	}
6158 
6159 	ASSERT(DB_TYPE(ire_fp_mp) == M_DATA);
6160 	mp->b_rptr = (uchar_t *)ipha - ire_fp_mp_len;
6161 	bcopy(ire_fp_mp->b_rptr, mp->b_rptr, ire_fp_mp_len);
6162 
6163 	UPDATE_OB_PKT_COUNT(ire);
6164 	ire->ire_last_used_time = lbolt;
6165 
6166 	if (ILL_POLL_CAPABLE(ill)) {
6167 		/*
6168 		 * Send the packet directly to DLD, where it may be queued
6169 		 * depending on the availability of transmit resources at
6170 		 * the media layer.
6171 		 */
6172 		IP_POLL_ILL_TX(ill, mp);
6173 	} else {
6174 		putnext(ire->ire_stq, mp);
6175 	}
6176 
6177 	if (ipif != NULL)
6178 		ipif_refrele(ipif);
6179 	IRE_REFRELE(ire);
6180 }
6181 
6182 /*
6183  * This routine handles all messages passed downstream.  It either
6184  * consumes the message or passes it downstream; it never queues a
6185  * a message.
6186  */
6187 static void
6188 udp_output(conn_t *connp, mblk_t *mp, struct sockaddr *addr, socklen_t addrlen)
6189 {
6190 	sin6_t		*sin6;
6191 	sin_t		*sin;
6192 	ipaddr_t	v4dst;
6193 	uint16_t	port;
6194 	uint_t		srcid;
6195 	queue_t		*q = connp->conn_wq;
6196 	udp_t		*udp = connp->conn_udp;
6197 	t_scalar_t	optlen;
6198 	int		error = 0;
6199 	struct sockaddr_storage ss;
6200 
6201 	TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_START,
6202 	    "udp_wput_start: connp %p mp %p", connp, mp);
6203 
6204 	/*
6205 	 * We directly handle several cases here: T_UNITDATA_REQ message
6206 	 * coming down as M_PROTO/M_PCPROTO and M_DATA messages for both
6207 	 * connected and non-connected socket.  The latter carries the
6208 	 * address structure along when this routine gets called.
6209 	 */
6210 	switch (DB_TYPE(mp)) {
6211 	case M_DATA:
6212 		if (!udp->udp_direct_sockfs || udp->udp_state != TS_DATA_XFER) {
6213 			if (!udp->udp_direct_sockfs ||
6214 			    addr == NULL || addrlen == 0) {
6215 				/* Not connected; address is required */
6216 				BUMP_MIB(&udp_mib, udpOutErrors);
6217 				UDP_STAT(udp_out_err_notconn);
6218 				freemsg(mp);
6219 				TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6220 				    "udp_wput_end: connp %p (%S)", connp,
6221 				    "not-connected; address required");
6222 				return;
6223 			}
6224 			ASSERT(udp->udp_issocket);
6225 			UDP_DBGSTAT(udp_data_notconn);
6226 			/* Not connected; do some more checks below */
6227 			optlen = 0;
6228 			break;
6229 		}
6230 		/* M_DATA for connected socket */
6231 		UDP_DBGSTAT(udp_data_conn);
6232 		IN6_V4MAPPED_TO_IPADDR(&udp->udp_v6dst, v4dst);
6233 
6234 		/* Initialize addr and addrlen as if they're passed in */
6235 		if (udp->udp_family == AF_INET) {
6236 			sin = (sin_t *)&ss;
6237 			sin->sin_family = AF_INET;
6238 			sin->sin_port = udp->udp_dstport;
6239 			sin->sin_addr.s_addr = v4dst;
6240 			addr = (struct sockaddr *)sin;
6241 			addrlen = sizeof (*sin);
6242 		} else {
6243 			sin6 = (sin6_t *)&ss;
6244 			sin6->sin6_family = AF_INET6;
6245 			sin6->sin6_port = udp->udp_dstport;
6246 			sin6->sin6_flowinfo = udp->udp_flowinfo;
6247 			sin6->sin6_addr = udp->udp_v6dst;
6248 			sin6->sin6_scope_id = 0;
6249 			sin6->__sin6_src_id = 0;
6250 			addr = (struct sockaddr *)sin6;
6251 			addrlen = sizeof (*sin6);
6252 		}
6253 
6254 		if (udp->udp_family == AF_INET ||
6255 		    IN6_IS_ADDR_V4MAPPED(&udp->udp_v6dst)) {
6256 			/*
6257 			 * Handle both AF_INET and AF_INET6; the latter
6258 			 * for IPV4 mapped destination addresses.  Note
6259 			 * here that both addr and addrlen point to the
6260 			 * corresponding struct depending on the address
6261 			 * family of the socket.
6262 			 */
6263 			mp = udp_output_v4(connp, mp, v4dst,
6264 			    udp->udp_dstport, 0, &error);
6265 		} else {
6266 			mp = udp_output_v6(connp, mp, sin6, 0, &error);
6267 		}
6268 		if (error != 0) {
6269 			ASSERT(addr != NULL && addrlen != 0);
6270 			goto ud_error;
6271 		}
6272 		return;
6273 	case M_PROTO:
6274 	case M_PCPROTO: {
6275 		struct T_unitdata_req *tudr;
6276 
6277 		ASSERT((uintptr_t)MBLKL(mp) <= (uintptr_t)INT_MAX);
6278 		tudr = (struct T_unitdata_req *)mp->b_rptr;
6279 
6280 		/* Handle valid T_UNITDATA_REQ here */
6281 		if (MBLKL(mp) >= sizeof (*tudr) &&
6282 		    ((t_primp_t)mp->b_rptr)->type == T_UNITDATA_REQ) {
6283 			if (mp->b_cont == NULL) {
6284 				TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6285 				    "udp_wput_end: q %p (%S)", q, "badaddr");
6286 				error = EPROTO;
6287 				goto ud_error;
6288 			}
6289 
6290 			if (!MBLKIN(mp, 0, tudr->DEST_offset +
6291 			    tudr->DEST_length)) {
6292 				TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6293 				    "udp_wput_end: q %p (%S)", q, "badaddr");
6294 				error = EADDRNOTAVAIL;
6295 				goto ud_error;
6296 			}
6297 			/*
6298 			 * If a port has not been bound to the stream, fail.
6299 			 * This is not a problem when sockfs is directly
6300 			 * above us, because it will ensure that the socket
6301 			 * is first bound before allowing data to be sent.
6302 			 */
6303 			if (udp->udp_state == TS_UNBND) {
6304 				TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6305 				    "udp_wput_end: q %p (%S)", q, "outstate");
6306 				error = EPROTO;
6307 				goto ud_error;
6308 			}
6309 			addr = (struct sockaddr *)
6310 			    &mp->b_rptr[tudr->DEST_offset];
6311 			addrlen = tudr->DEST_length;
6312 			optlen = tudr->OPT_length;
6313 			if (optlen != 0)
6314 				UDP_STAT(udp_out_opt);
6315 			break;
6316 		}
6317 		/* FALLTHRU */
6318 	}
6319 	default:
6320 		udp_become_writer(connp, mp, udp_wput_other_wrapper,
6321 		    SQTAG_UDP_OUTPUT);
6322 		return;
6323 	}
6324 	ASSERT(addr != NULL);
6325 
6326 	switch (udp->udp_family) {
6327 	case AF_INET6:
6328 		sin6 = (sin6_t *)addr;
6329 		if (!OK_32PTR((char *)sin6) || addrlen != sizeof (sin6_t) ||
6330 		    sin6->sin6_family != AF_INET6) {
6331 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6332 			    "udp_wput_end: q %p (%S)", q, "badaddr");
6333 			error = EADDRNOTAVAIL;
6334 			goto ud_error;
6335 		}
6336 
6337 		if (!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
6338 			/*
6339 			 * Destination is a non-IPv4-compatible IPv6 address.
6340 			 * Send out an IPv6 format packet.
6341 			 */
6342 			mp = udp_output_v6(connp, mp, sin6, optlen, &error);
6343 			if (error != 0)
6344 				goto ud_error;
6345 
6346 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6347 			    "udp_wput_end: q %p (%S)", q, "udp_output_v6");
6348 			return;
6349 		}
6350 		/*
6351 		 * If the local address is not zero or a mapped address
6352 		 * return an error.  It would be possible to send an IPv4
6353 		 * packet but the response would never make it back to the
6354 		 * application since it is bound to a non-mapped address.
6355 		 */
6356 		if (!IN6_IS_ADDR_V4MAPPED(&udp->udp_v6src) &&
6357 		    !IN6_IS_ADDR_UNSPECIFIED(&udp->udp_v6src)) {
6358 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6359 			    "udp_wput_end: q %p (%S)", q, "badaddr");
6360 			error = EADDRNOTAVAIL;
6361 			goto ud_error;
6362 		}
6363 		/* Send IPv4 packet without modifying udp_ipversion */
6364 		/* Extract port and ipaddr */
6365 		port = sin6->sin6_port;
6366 		IN6_V4MAPPED_TO_IPADDR(&sin6->sin6_addr, v4dst);
6367 		srcid = sin6->__sin6_src_id;
6368 		break;
6369 
6370 	case AF_INET:
6371 		sin = (sin_t *)addr;
6372 		if (!OK_32PTR((char *)sin) || addrlen != sizeof (sin_t) ||
6373 		    sin->sin_family != AF_INET) {
6374 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6375 			    "udp_wput_end: q %p (%S)", q, "badaddr");
6376 			error = EADDRNOTAVAIL;
6377 			goto ud_error;
6378 		}
6379 		/* Extract port and ipaddr */
6380 		port = sin->sin_port;
6381 		v4dst = sin->sin_addr.s_addr;
6382 		srcid = 0;
6383 		break;
6384 	}
6385 
6386 	/*
6387 	 * If options passed in, feed it for verification and handling
6388 	 */
6389 	if (optlen != 0) {
6390 		ASSERT(DB_TYPE(mp) != M_DATA);
6391 		if (udp_unitdata_opt_process(q, mp, &error, NULL) < 0) {
6392 			/* failure */
6393 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_END,
6394 			    "udp_wput_end: q %p (%S)", q,
6395 			    "udp_unitdata_opt_process");
6396 			goto ud_error;
6397 		}
6398 		/*
6399 		 * Note: success in processing options.
6400 		 * mp option buffer represented by
6401 		 * OPT_length/offset now potentially modified
6402 		 * and contain option setting results
6403 		 */
6404 	}
6405 	ASSERT(error == 0);
6406 	mp = udp_output_v4(connp, mp, v4dst, port, srcid, &error);
6407 	if (error != 0) {
6408 ud_error:
6409 		UDP_STAT(udp_out_err_output);
6410 		ASSERT(mp != NULL);
6411 		/* mp is freed by the following routine */
6412 		udp_ud_err(q, mp, (uchar_t *)addr, (t_scalar_t)addrlen,
6413 		    (t_scalar_t)error);
6414 	}
6415 }
6416 
6417 /* ARGSUSED */
6418 static void
6419 udp_output_wrapper(void *arg, mblk_t *mp, void *arg2)
6420 {
6421 	udp_output((conn_t *)arg, mp, NULL, 0);
6422 	_UDP_EXIT((conn_t *)arg);
6423 }
6424 
6425 static void
6426 udp_wput(queue_t *q, mblk_t *mp)
6427 {
6428 	_UDP_ENTER(Q_TO_CONN(UDP_WR(q)), mp, udp_output_wrapper,
6429 	    SQTAG_UDP_WPUT);
6430 }
6431 
6432 /*
6433  * Allocate and prepare a T_UNITDATA_REQ message.
6434  */
6435 static mblk_t *
6436 udp_tudr_alloc(struct sockaddr *addr, socklen_t addrlen)
6437 {
6438 	struct T_unitdata_req *tudr;
6439 	mblk_t *mp;
6440 
6441 	mp = allocb(sizeof (*tudr) + addrlen, BPRI_MED);
6442 	if (mp != NULL) {
6443 		mp->b_wptr += sizeof (*tudr) + addrlen;
6444 		DB_TYPE(mp) = M_PROTO;
6445 
6446 		tudr = (struct T_unitdata_req *)mp->b_rptr;
6447 		tudr->PRIM_type = T_UNITDATA_REQ;
6448 		tudr->DEST_length = addrlen;
6449 		tudr->DEST_offset = (t_scalar_t)sizeof (*tudr);
6450 		tudr->OPT_length = 0;
6451 		tudr->OPT_offset = 0;
6452 		bcopy(addr, tudr+1, addrlen);
6453 	}
6454 	return (mp);
6455 }
6456 
6457 /*
6458  * Entry point for sockfs when udp is in "direct sockfs" mode.  This mode
6459  * is valid when we are directly beneath the stream head, and thus sockfs
6460  * is able to bypass STREAMS and directly call us, passing along the sockaddr
6461  * structure without the cumbersome T_UNITDATA_REQ interface.  Note that
6462  * this is done for both connected and non-connected endpoint.
6463  */
6464 void
6465 udp_wput_data(queue_t *q, mblk_t *mp, struct sockaddr *addr, socklen_t addrlen)
6466 {
6467 	conn_t	*connp;
6468 	udp_t	*udp;
6469 
6470 	q = UDP_WR(q);
6471 	connp = Q_TO_CONN(q);
6472 	udp = connp->conn_udp;
6473 
6474 	/* udpsockfs should only send down M_DATA for this entry point */
6475 	ASSERT(DB_TYPE(mp) == M_DATA);
6476 
6477 	mutex_enter(&connp->conn_lock);
6478 	UDP_MODE_ASSERTIONS(udp, UDP_ENTER);
6479 
6480 	if (udp->udp_mode != UDP_MT_HOT) {
6481 		/*
6482 		 * We can't enter this conn right away because another
6483 		 * thread is currently executing as writer; therefore we
6484 		 * need to deposit the message into the squeue to be
6485 		 * drained later.  If a socket address is present, we
6486 		 * need to create a T_UNITDATA_REQ message as placeholder.
6487 		 */
6488 		if (addr != NULL && addrlen != 0) {
6489 			mblk_t *tudr_mp = udp_tudr_alloc(addr, addrlen);
6490 
6491 			if (tudr_mp == NULL) {
6492 				mutex_exit(&connp->conn_lock);
6493 				BUMP_MIB(&udp_mib, udpOutErrors);
6494 				UDP_STAT(udp_out_err_tudr);
6495 				freemsg(mp);
6496 				return;
6497 			}
6498 			/* Tag the packet with T_UNITDATA_REQ */
6499 			tudr_mp->b_cont = mp;
6500 			mp = tudr_mp;
6501 		}
6502 		mutex_exit(&connp->conn_lock);
6503 		udp_enter(connp, mp, udp_output_wrapper, SQTAG_UDP_WPUT);
6504 		return;
6505 	}
6506 
6507 	/* We can execute as reader right away. */
6508 	UDP_READERS_INCREF(udp);
6509 	mutex_exit(&connp->conn_lock);
6510 
6511 	udp_output(connp, mp, addr, addrlen);
6512 
6513 	mutex_enter(&connp->conn_lock);
6514 	UDP_MODE_ASSERTIONS(udp, UDP_EXIT);
6515 	UDP_READERS_DECREF(udp);
6516 	mutex_exit(&connp->conn_lock);
6517 }
6518 
6519 /*
6520  * udp_output_v6():
6521  * Assumes that udp_wput did some sanity checking on the destination
6522  * address.
6523  */
6524 static mblk_t *
6525 udp_output_v6(conn_t *connp, mblk_t *mp, sin6_t *sin6, t_scalar_t tudr_optlen,
6526     int *error)
6527 {
6528 	ip6_t		*ip6h;
6529 	ip6i_t		*ip6i;	/* mp1->b_rptr even if no ip6i_t */
6530 	mblk_t		*mp1 = (DB_TYPE(mp) == M_DATA ? mp : mp->b_cont);
6531 	mblk_t		*mp2;
6532 	int		udp_ip_hdr_len = IPV6_HDR_LEN + UDPH_SIZE;
6533 	size_t		ip_len;
6534 	udpha_t		*udph;
6535 	udp_t		*udp = connp->conn_udp;
6536 	queue_t		*q = connp->conn_wq;
6537 	ip6_pkt_t	ipp_s;	/* For ancillary data options */
6538 	ip6_pkt_t	*ipp = &ipp_s;
6539 	ip6_pkt_t	*tipp;	/* temporary ipp */
6540 	uint32_t	csum = 0;
6541 	uint_t		ignore = 0;
6542 	uint_t		option_exists = 0, is_sticky = 0;
6543 	uint8_t		*cp;
6544 	uint8_t		*nxthdr_ptr;
6545 
6546 	*error = 0;
6547 
6548 	/* mp1 points to the M_DATA mblk carrying the packet */
6549 	ASSERT(mp1 != NULL && DB_TYPE(mp1) == M_DATA);
6550 	ASSERT(tudr_optlen == 0 || DB_TYPE(mp) != M_DATA);
6551 
6552 	/*
6553 	 * If the local address is a mapped address return
6554 	 * an error.
6555 	 * It would be possible to send an IPv6 packet but the
6556 	 * response would never make it back to the application
6557 	 * since it is bound to a mapped address.
6558 	 */
6559 	if (IN6_IS_ADDR_V4MAPPED(&udp->udp_v6src)) {
6560 		*error = EADDRNOTAVAIL;
6561 		goto done;
6562 	}
6563 
6564 	ipp->ipp_fields = 0;
6565 	ipp->ipp_sticky_ignored = 0;
6566 
6567 	/*
6568 	 * If TPI options passed in, feed it for verification and handling
6569 	 */
6570 	if (tudr_optlen != 0) {
6571 		if (udp_unitdata_opt_process(q, mp, error, (void *)ipp) < 0) {
6572 			/* failure */
6573 			goto done;
6574 		}
6575 		ignore = ipp->ipp_sticky_ignored;
6576 		ASSERT(*error == 0);
6577 	}
6578 
6579 	if (sin6->sin6_scope_id != 0 &&
6580 	    IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
6581 		/*
6582 		 * IPPF_SCOPE_ID is special.  It's neither a sticky
6583 		 * option nor ancillary data.  It needs to be
6584 		 * explicitly set in options_exists.
6585 		 */
6586 		option_exists |= IPPF_SCOPE_ID;
6587 	}
6588 
6589 	if ((udp->udp_sticky_ipp.ipp_fields == 0) && (ipp->ipp_fields == 0)) {
6590 		/* No sticky options nor ancillary data. */
6591 		goto no_options;
6592 	}
6593 
6594 	/*
6595 	 * Go through the options figuring out where each is going to
6596 	 * come from and build two masks.  The first mask indicates if
6597 	 * the option exists at all.  The second mask indicates if the
6598 	 * option is sticky or ancillary.
6599 	 */
6600 	if (!(ignore & IPPF_HOPOPTS)) {
6601 		if (ipp->ipp_fields & IPPF_HOPOPTS) {
6602 			option_exists |= IPPF_HOPOPTS;
6603 			udp_ip_hdr_len += ipp->ipp_hopoptslen;
6604 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_HOPOPTS) {
6605 			option_exists |= IPPF_HOPOPTS;
6606 			is_sticky |= IPPF_HOPOPTS;
6607 			udp_ip_hdr_len += udp->udp_sticky_ipp.ipp_hopoptslen;
6608 		}
6609 	}
6610 
6611 	if (!(ignore & IPPF_RTHDR)) {
6612 		if (ipp->ipp_fields & IPPF_RTHDR) {
6613 			option_exists |= IPPF_RTHDR;
6614 			udp_ip_hdr_len += ipp->ipp_rthdrlen;
6615 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_RTHDR) {
6616 			option_exists |= IPPF_RTHDR;
6617 			is_sticky |= IPPF_RTHDR;
6618 			udp_ip_hdr_len += udp->udp_sticky_ipp.ipp_rthdrlen;
6619 		}
6620 	}
6621 
6622 	if (!(ignore & IPPF_RTDSTOPTS) && (option_exists & IPPF_RTHDR)) {
6623 		if (ipp->ipp_fields & IPPF_RTDSTOPTS) {
6624 			option_exists |= IPPF_RTDSTOPTS;
6625 			udp_ip_hdr_len += ipp->ipp_rtdstoptslen;
6626 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_RTDSTOPTS) {
6627 			option_exists |= IPPF_RTDSTOPTS;
6628 			is_sticky |= IPPF_RTDSTOPTS;
6629 			udp_ip_hdr_len += udp->udp_sticky_ipp.ipp_rtdstoptslen;
6630 		}
6631 	}
6632 
6633 	if (!(ignore & IPPF_DSTOPTS)) {
6634 		if (ipp->ipp_fields & IPPF_DSTOPTS) {
6635 			option_exists |= IPPF_DSTOPTS;
6636 			udp_ip_hdr_len += ipp->ipp_dstoptslen;
6637 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_DSTOPTS) {
6638 			option_exists |= IPPF_DSTOPTS;
6639 			is_sticky |= IPPF_DSTOPTS;
6640 			udp_ip_hdr_len += udp->udp_sticky_ipp.ipp_dstoptslen;
6641 		}
6642 	}
6643 
6644 	if (!(ignore & IPPF_IFINDEX)) {
6645 		if (ipp->ipp_fields & IPPF_IFINDEX) {
6646 			option_exists |= IPPF_IFINDEX;
6647 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_IFINDEX) {
6648 			option_exists |= IPPF_IFINDEX;
6649 			is_sticky |= IPPF_IFINDEX;
6650 		}
6651 	}
6652 
6653 	if (!(ignore & IPPF_ADDR)) {
6654 		if (ipp->ipp_fields & IPPF_ADDR) {
6655 			option_exists |= IPPF_ADDR;
6656 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_ADDR) {
6657 			option_exists |= IPPF_ADDR;
6658 			is_sticky |= IPPF_ADDR;
6659 		}
6660 	}
6661 
6662 	if (!(ignore & IPPF_DONTFRAG)) {
6663 		if (ipp->ipp_fields & IPPF_DONTFRAG) {
6664 			option_exists |= IPPF_DONTFRAG;
6665 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_DONTFRAG) {
6666 			option_exists |= IPPF_DONTFRAG;
6667 			is_sticky |= IPPF_DONTFRAG;
6668 		}
6669 	}
6670 
6671 	if (!(ignore & IPPF_USE_MIN_MTU)) {
6672 		if (ipp->ipp_fields & IPPF_USE_MIN_MTU) {
6673 			option_exists |= IPPF_USE_MIN_MTU;
6674 		} else if (udp->udp_sticky_ipp.ipp_fields &
6675 		    IPPF_USE_MIN_MTU) {
6676 			option_exists |= IPPF_USE_MIN_MTU;
6677 			is_sticky |= IPPF_USE_MIN_MTU;
6678 		}
6679 	}
6680 
6681 	if (!(ignore & IPPF_HOPLIMIT) && (ipp->ipp_fields & IPPF_HOPLIMIT))
6682 		option_exists |= IPPF_HOPLIMIT;
6683 	/* IPV6_HOPLIMIT can never be sticky */
6684 	ASSERT(!(udp->udp_sticky_ipp.ipp_fields & IPPF_HOPLIMIT));
6685 
6686 	if (!(ignore & IPPF_UNICAST_HOPS) &&
6687 	    (udp->udp_sticky_ipp.ipp_fields & IPPF_UNICAST_HOPS)) {
6688 		option_exists |= IPPF_UNICAST_HOPS;
6689 		is_sticky |= IPPF_UNICAST_HOPS;
6690 	}
6691 
6692 	if (!(ignore & IPPF_MULTICAST_HOPS) &&
6693 	    (udp->udp_sticky_ipp.ipp_fields & IPPF_MULTICAST_HOPS)) {
6694 		option_exists |= IPPF_MULTICAST_HOPS;
6695 		is_sticky |= IPPF_MULTICAST_HOPS;
6696 	}
6697 
6698 	if (!(ignore & IPPF_TCLASS)) {
6699 		if (ipp->ipp_fields & IPPF_TCLASS) {
6700 			option_exists |= IPPF_TCLASS;
6701 		} else if (udp->udp_sticky_ipp.ipp_fields & IPPF_TCLASS) {
6702 			option_exists |= IPPF_TCLASS;
6703 			is_sticky |= IPPF_TCLASS;
6704 		}
6705 	}
6706 
6707 no_options:
6708 
6709 	/*
6710 	 * If any options carried in the ip6i_t were specified, we
6711 	 * need to account for the ip6i_t in the data we'll be sending
6712 	 * down.
6713 	 */
6714 	if (option_exists & IPPF_HAS_IP6I)
6715 		udp_ip_hdr_len += sizeof (ip6i_t);
6716 
6717 	/* check/fix buffer config, setup pointers into it */
6718 	ip6h = (ip6_t *)&mp1->b_rptr[-udp_ip_hdr_len];
6719 	if (DB_REF(mp1) != 1 || ((unsigned char *)ip6h < DB_BASE(mp1)) ||
6720 	    !OK_32PTR(ip6h)) {
6721 		/* Try to get everything in a single mblk next time */
6722 		if (udp_ip_hdr_len > udp->udp_max_hdr_len) {
6723 			udp->udp_max_hdr_len = udp_ip_hdr_len;
6724 			(void) mi_set_sth_wroff(UDP_RD(q),
6725 			    udp->udp_max_hdr_len + udp_wroff_extra);
6726 		}
6727 		mp2 = allocb(udp_ip_hdr_len + udp_wroff_extra, BPRI_LO);
6728 		if (mp2 == NULL) {
6729 			*error = ENOMEM;
6730 			goto done;
6731 		}
6732 		mp2->b_wptr = DB_LIM(mp2);
6733 		mp2->b_cont = mp1;
6734 		mp1 = mp2;
6735 		if (DB_TYPE(mp) != M_DATA)
6736 			mp->b_cont = mp1;
6737 		else
6738 			mp = mp1;
6739 
6740 		ip6h = (ip6_t *)(mp1->b_wptr - udp_ip_hdr_len);
6741 	}
6742 	mp1->b_rptr = (unsigned char *)ip6h;
6743 	ip6i = (ip6i_t *)ip6h;
6744 
6745 #define	ANCIL_OR_STICKY_PTR(f) ((is_sticky & f) ? &udp->udp_sticky_ipp : ipp)
6746 	if (option_exists & IPPF_HAS_IP6I) {
6747 		ip6h = (ip6_t *)&ip6i[1];
6748 		ip6i->ip6i_flags = 0;
6749 		ip6i->ip6i_vcf = IPV6_DEFAULT_VERS_AND_FLOW;
6750 
6751 		/* sin6_scope_id takes precendence over IPPF_IFINDEX */
6752 		if (option_exists & IPPF_SCOPE_ID) {
6753 			ip6i->ip6i_flags |= IP6I_IFINDEX;
6754 			ip6i->ip6i_ifindex = sin6->sin6_scope_id;
6755 		} else if (option_exists & IPPF_IFINDEX) {
6756 			tipp = ANCIL_OR_STICKY_PTR(IPPF_IFINDEX);
6757 			ASSERT(tipp->ipp_ifindex != 0);
6758 			ip6i->ip6i_flags |= IP6I_IFINDEX;
6759 			ip6i->ip6i_ifindex = tipp->ipp_ifindex;
6760 		}
6761 
6762 		if (option_exists & IPPF_ADDR) {
6763 			/*
6764 			 * Enable per-packet source address verification if
6765 			 * IPV6_PKTINFO specified the source address.
6766 			 * ip6_src is set in the transport's _wput function.
6767 			 */
6768 			ip6i->ip6i_flags |= IP6I_VERIFY_SRC;
6769 		}
6770 
6771 		if (option_exists & IPPF_DONTFRAG) {
6772 			ip6i->ip6i_flags |= IP6I_DONTFRAG;
6773 		}
6774 
6775 		if (option_exists & IPPF_USE_MIN_MTU) {
6776 			ip6i->ip6i_flags = IP6I_API_USE_MIN_MTU(
6777 			    ip6i->ip6i_flags, ipp->ipp_use_min_mtu);
6778 		}
6779 
6780 		if (option_exists & IPPF_NEXTHOP) {
6781 			tipp = ANCIL_OR_STICKY_PTR(IPPF_NEXTHOP);
6782 			ASSERT(!IN6_IS_ADDR_UNSPECIFIED(&tipp->ipp_nexthop));
6783 			ip6i->ip6i_flags |= IP6I_NEXTHOP;
6784 			ip6i->ip6i_nexthop = tipp->ipp_nexthop;
6785 		}
6786 
6787 		/*
6788 		 * tell IP this is an ip6i_t private header
6789 		 */
6790 		ip6i->ip6i_nxt = IPPROTO_RAW;
6791 	}
6792 
6793 	/* Initialize IPv6 header */
6794 	ip6h->ip6_vcf = IPV6_DEFAULT_VERS_AND_FLOW;
6795 	bzero(&ip6h->ip6_src, sizeof (ip6h->ip6_src));
6796 
6797 	/* Set the hoplimit of the outgoing packet. */
6798 	if (option_exists & IPPF_HOPLIMIT) {
6799 		/* IPV6_HOPLIMIT ancillary data overrides all other settings. */
6800 		ip6h->ip6_hops = ipp->ipp_hoplimit;
6801 		ip6i->ip6i_flags |= IP6I_HOPLIMIT;
6802 	} else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
6803 		ip6h->ip6_hops = udp->udp_multicast_ttl;
6804 		if (option_exists & IPPF_MULTICAST_HOPS)
6805 			ip6i->ip6i_flags |= IP6I_HOPLIMIT;
6806 	} else {
6807 		ip6h->ip6_hops = udp->udp_ttl;
6808 		if (option_exists & IPPF_UNICAST_HOPS)
6809 			ip6i->ip6i_flags |= IP6I_HOPLIMIT;
6810 	}
6811 
6812 	if (option_exists & IPPF_ADDR) {
6813 		tipp = ANCIL_OR_STICKY_PTR(IPPF_ADDR);
6814 		ASSERT(!IN6_IS_ADDR_UNSPECIFIED(&tipp->ipp_addr));
6815 		ip6h->ip6_src = tipp->ipp_addr;
6816 	} else {
6817 		/*
6818 		 * The source address was not set using IPV6_PKTINFO.
6819 		 * First look at the bound source.
6820 		 * If unspecified fallback to __sin6_src_id.
6821 		 */
6822 		ip6h->ip6_src = udp->udp_v6src;
6823 		if (sin6->__sin6_src_id != 0 &&
6824 		    IN6_IS_ADDR_UNSPECIFIED(&ip6h->ip6_src)) {
6825 			ip_srcid_find_id(sin6->__sin6_src_id,
6826 			    &ip6h->ip6_src, connp->conn_zoneid);
6827 		}
6828 	}
6829 
6830 	nxthdr_ptr = (uint8_t *)&ip6h->ip6_nxt;
6831 	cp = (uint8_t *)&ip6h[1];
6832 
6833 	/*
6834 	 * Here's where we have to start stringing together
6835 	 * any extension headers in the right order:
6836 	 * Hop-by-hop, destination, routing, and final destination opts.
6837 	 */
6838 	if (option_exists & IPPF_HOPOPTS) {
6839 		/* Hop-by-hop options */
6840 		ip6_hbh_t *hbh = (ip6_hbh_t *)cp;
6841 		tipp = ANCIL_OR_STICKY_PTR(IPPF_HOPOPTS);
6842 
6843 		*nxthdr_ptr = IPPROTO_HOPOPTS;
6844 		nxthdr_ptr = &hbh->ip6h_nxt;
6845 
6846 		bcopy(tipp->ipp_hopopts, cp, tipp->ipp_hopoptslen);
6847 		cp += tipp->ipp_hopoptslen;
6848 	}
6849 	/*
6850 	 * En-route destination options
6851 	 * Only do them if there's a routing header as well
6852 	 */
6853 	if (option_exists & IPPF_RTDSTOPTS) {
6854 		ip6_dest_t *dst = (ip6_dest_t *)cp;
6855 		tipp = ANCIL_OR_STICKY_PTR(IPPF_RTDSTOPTS);
6856 
6857 		*nxthdr_ptr = IPPROTO_DSTOPTS;
6858 		nxthdr_ptr = &dst->ip6d_nxt;
6859 
6860 		bcopy(tipp->ipp_rtdstopts, cp, tipp->ipp_rtdstoptslen);
6861 		cp += tipp->ipp_rtdstoptslen;
6862 	}
6863 	/*
6864 	 * Routing header next
6865 	 */
6866 	if (option_exists & IPPF_RTHDR) {
6867 		ip6_rthdr_t *rt = (ip6_rthdr_t *)cp;
6868 		tipp = ANCIL_OR_STICKY_PTR(IPPF_RTHDR);
6869 
6870 		*nxthdr_ptr = IPPROTO_ROUTING;
6871 		nxthdr_ptr = &rt->ip6r_nxt;
6872 
6873 		bcopy(tipp->ipp_rthdr, cp, tipp->ipp_rthdrlen);
6874 		cp += tipp->ipp_rthdrlen;
6875 	}
6876 	/*
6877 	 * Do ultimate destination options
6878 	 */
6879 	if (option_exists & IPPF_DSTOPTS) {
6880 		ip6_dest_t *dest = (ip6_dest_t *)cp;
6881 		tipp = ANCIL_OR_STICKY_PTR(IPPF_DSTOPTS);
6882 
6883 		*nxthdr_ptr = IPPROTO_DSTOPTS;
6884 		nxthdr_ptr = &dest->ip6d_nxt;
6885 
6886 		bcopy(tipp->ipp_dstopts, cp, tipp->ipp_dstoptslen);
6887 		cp += tipp->ipp_dstoptslen;
6888 	}
6889 	/*
6890 	 * Now set the last header pointer to the proto passed in
6891 	 */
6892 	ASSERT((int)(cp - (uint8_t *)ip6i) == (udp_ip_hdr_len - UDPH_SIZE));
6893 	*nxthdr_ptr = IPPROTO_UDP;
6894 
6895 	/* Update UDP header */
6896 	udph = (udpha_t *)((uchar_t *)ip6i + udp_ip_hdr_len - UDPH_SIZE);
6897 	udph->uha_dst_port = sin6->sin6_port;
6898 	udph->uha_src_port = udp->udp_port;
6899 
6900 	/*
6901 	 * Copy in the destination address
6902 	 */
6903 	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
6904 		ip6h->ip6_dst = ipv6_loopback;
6905 	else
6906 		ip6h->ip6_dst = sin6->sin6_addr;
6907 
6908 	ip6h->ip6_vcf =
6909 	    (IPV6_DEFAULT_VERS_AND_FLOW & IPV6_VERS_AND_FLOW_MASK) |
6910 	    (sin6->sin6_flowinfo & ~IPV6_VERS_AND_FLOW_MASK);
6911 
6912 	if (option_exists & IPPF_TCLASS) {
6913 		tipp = ANCIL_OR_STICKY_PTR(IPPF_TCLASS);
6914 		ip6h->ip6_vcf = IPV6_TCLASS_FLOW(ip6h->ip6_vcf,
6915 		    tipp->ipp_tclass);
6916 	}
6917 
6918 	if (option_exists & IPPF_RTHDR) {
6919 		ip6_rthdr_t	*rth;
6920 
6921 		/*
6922 		 * Perform any processing needed for source routing.
6923 		 * We know that all extension headers will be in the same mblk
6924 		 * as the IPv6 header.
6925 		 */
6926 		rth = ip_find_rthdr_v6(ip6h, mp1->b_wptr);
6927 		if (rth != NULL && rth->ip6r_segleft != 0) {
6928 			if (rth->ip6r_type != IPV6_RTHDR_TYPE_0) {
6929 				/*
6930 				 * Drop packet - only support Type 0 routing.
6931 				 * Notify the application as well.
6932 				 */
6933 				*error = EPROTO;
6934 				goto done;
6935 			}
6936 
6937 			/*
6938 			 * rth->ip6r_len is twice the number of
6939 			 * addresses in the header. Thus it must be even.
6940 			 */
6941 			if (rth->ip6r_len & 0x1) {
6942 				*error = EPROTO;
6943 				goto done;
6944 			}
6945 			/*
6946 			 * Shuffle the routing header and ip6_dst
6947 			 * addresses, and get the checksum difference
6948 			 * between the first hop (in ip6_dst) and
6949 			 * the destination (in the last routing hdr entry).
6950 			 */
6951 			csum = ip_massage_options_v6(ip6h, rth);
6952 			/*
6953 			 * Verify that the first hop isn't a mapped address.
6954 			 * Routers along the path need to do this verification
6955 			 * for subsequent hops.
6956 			 */
6957 			if (IN6_IS_ADDR_V4MAPPED(&ip6h->ip6_dst)) {
6958 				*error = EADDRNOTAVAIL;
6959 				goto done;
6960 			}
6961 
6962 			cp += (rth->ip6r_len + 1)*8;
6963 		}
6964 	}
6965 
6966 	/* count up length of UDP packet */
6967 	ip_len = (mp1->b_wptr - (unsigned char *)ip6h) - IPV6_HDR_LEN;
6968 	if ((mp2 = mp1->b_cont) != NULL) {
6969 		do {
6970 			ASSERT((uintptr_t)MBLKL(mp2) <= (uintptr_t)UINT_MAX);
6971 			ip_len += (uint32_t)MBLKL(mp2);
6972 		} while ((mp2 = mp2->b_cont) != NULL);
6973 	}
6974 
6975 	/*
6976 	 * If the size of the packet is greater than the maximum allowed by
6977 	 * ip, return an error. Passing this down could cause panics because
6978 	 * the size will have wrapped and be inconsistent with the msg size.
6979 	 */
6980 	if (ip_len > IP_MAXPACKET) {
6981 		*error = EMSGSIZE;
6982 		goto done;
6983 	}
6984 
6985 	/* Store the UDP length. Subtract length of extension hdrs */
6986 	udph->uha_length = htons(ip_len + IPV6_HDR_LEN -
6987 	    (int)((uchar_t *)udph - (uchar_t *)ip6h));
6988 
6989 	/*
6990 	 * We make it easy for IP to include our pseudo header
6991 	 * by putting our length in uh_checksum, modified (if
6992 	 * we have a routing header) by the checksum difference
6993 	 * between the ultimate destination and first hop addresses.
6994 	 * Note: UDP over IPv6 must always checksum the packet.
6995 	 */
6996 	csum += udph->uha_length;
6997 	csum = (csum & 0xFFFF) + (csum >> 16);
6998 	udph->uha_checksum = (uint16_t)csum;
6999 
7000 #ifdef _LITTLE_ENDIAN
7001 	ip_len = htons(ip_len);
7002 #endif
7003 	ip6h->ip6_plen = ip_len;
7004 
7005 	if (DB_TYPE(mp) != M_DATA) {
7006 		ASSERT(mp != mp1);
7007 		freeb(mp);
7008 	}
7009 
7010 	/* mp has been consumed and we'll return success */
7011 	ASSERT(*error == 0);
7012 	mp = NULL;
7013 
7014 	/* We're done. Pass the packet to IP */
7015 	BUMP_MIB(&udp_mib, udpOutDatagrams);
7016 	ip_output_v6(connp, mp1, q, IP_WPUT);
7017 
7018 done:
7019 	if (*error != 0) {
7020 		ASSERT(mp != NULL);
7021 		BUMP_MIB(&udp_mib, udpOutErrors);
7022 	}
7023 	return (mp);
7024 }
7025 
7026 static void
7027 udp_wput_other(queue_t *q, mblk_t *mp)
7028 {
7029 	uchar_t	*rptr = mp->b_rptr;
7030 	struct datab *db;
7031 	struct iocblk *iocp;
7032 	cred_t	*cr;
7033 	conn_t	*connp = Q_TO_CONN(q);
7034 	udp_t	*udp = connp->conn_udp;
7035 
7036 	TRACE_1(TR_FAC_UDP, TR_UDP_WPUT_OTHER_START,
7037 		"udp_wput_other_start: q %p", q);
7038 
7039 	db = mp->b_datap;
7040 
7041 	cr = DB_CREDDEF(mp, connp->conn_cred);
7042 
7043 	switch (db->db_type) {
7044 	case M_PROTO:
7045 	case M_PCPROTO:
7046 		if (mp->b_wptr - rptr < sizeof (t_scalar_t)) {
7047 			freemsg(mp);
7048 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7049 				"udp_wput_other_end: q %p (%S)",
7050 				q, "protoshort");
7051 			return;
7052 		}
7053 		switch (((t_primp_t)rptr)->type) {
7054 		case T_ADDR_REQ:
7055 			udp_addr_req(q, mp);
7056 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7057 				"udp_wput_other_end: q %p (%S)", q, "addrreq");
7058 			return;
7059 		case O_T_BIND_REQ:
7060 		case T_BIND_REQ:
7061 			udp_bind(q, mp);
7062 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7063 				"udp_wput_other_end: q %p (%S)", q, "bindreq");
7064 			return;
7065 		case T_CONN_REQ:
7066 			udp_connect(q, mp);
7067 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7068 				"udp_wput_other_end: q %p (%S)", q, "connreq");
7069 			return;
7070 		case T_CAPABILITY_REQ:
7071 			udp_capability_req(q, mp);
7072 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7073 				"udp_wput_other_end: q %p (%S)", q, "capabreq");
7074 			return;
7075 		case T_INFO_REQ:
7076 			udp_info_req(q, mp);
7077 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7078 				"udp_wput_other_end: q %p (%S)", q, "inforeq");
7079 			return;
7080 		case T_UNITDATA_REQ:
7081 			/*
7082 			 * If a T_UNITDATA_REQ gets here, the address must
7083 			 * be bad.  Valid T_UNITDATA_REQs are handled
7084 			 * in udp_wput.
7085 			 */
7086 			udp_ud_err(q, mp, NULL, 0, EADDRNOTAVAIL);
7087 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7088 				"udp_wput_other_end: q %p (%S)",
7089 				q, "unitdatareq");
7090 			return;
7091 		case T_UNBIND_REQ:
7092 			udp_unbind(q, mp);
7093 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7094 			    "udp_wput_other_end: q %p (%S)", q, "unbindreq");
7095 			return;
7096 		case T_SVR4_OPTMGMT_REQ:
7097 			if (!snmpcom_req(q, mp, udp_snmp_set, udp_snmp_get, cr))
7098 				/*
7099 				 * Use upper queue for option processing in
7100 				 * case the request is not handled at this
7101 				 * level and needs to be passed down to IP.
7102 				 */
7103 				(void) svr4_optcom_req(_WR(UDP_RD(q)),
7104 				    mp, cr, &udp_opt_obj);
7105 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7106 			    "udp_wput_other_end: q %p (%S)",
7107 			    q, "optmgmtreq");
7108 			return;
7109 
7110 		case T_OPTMGMT_REQ:
7111 			/*
7112 			 * Use upper queue for option processing in
7113 			 * case the request is not handled at this
7114 			 * level and needs to be passed down to IP.
7115 			 */
7116 			(void) tpi_optcom_req(_WR(UDP_RD(q)),
7117 			    mp, cr, &udp_opt_obj);
7118 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7119 				"udp_wput_other_end: q %p (%S)",
7120 				q, "optmgmtreq");
7121 			return;
7122 
7123 		case T_DISCON_REQ:
7124 			udp_disconnect(q, mp);
7125 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7126 				"udp_wput_other_end: q %p (%S)",
7127 				q, "disconreq");
7128 			return;
7129 
7130 		/* The following TPI message is not supported by udp. */
7131 		case O_T_CONN_RES:
7132 		case T_CONN_RES:
7133 			udp_err_ack(q, mp, TNOTSUPPORT, 0);
7134 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7135 				"udp_wput_other_end: q %p (%S)",
7136 				q, "connres/disconreq");
7137 			return;
7138 
7139 		/* The following 3 TPI messages are illegal for udp. */
7140 		case T_DATA_REQ:
7141 		case T_EXDATA_REQ:
7142 		case T_ORDREL_REQ:
7143 			udp_err_ack(q, mp, TNOTSUPPORT, 0);
7144 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7145 				"udp_wput_other_end: q %p (%S)",
7146 				q, "data/exdata/ordrel");
7147 			return;
7148 		default:
7149 			break;
7150 		}
7151 		break;
7152 	case M_FLUSH:
7153 		if (*rptr & FLUSHW)
7154 			flushq(q, FLUSHDATA);
7155 		break;
7156 	case M_IOCTL:
7157 		iocp = (struct iocblk *)mp->b_rptr;
7158 		switch (iocp->ioc_cmd) {
7159 		case TI_GETPEERNAME:
7160 			if (udp->udp_state != TS_DATA_XFER) {
7161 				/*
7162 				 * If a default destination address has not
7163 				 * been associated with the stream, then we
7164 				 * don't know the peer's name.
7165 				 */
7166 				iocp->ioc_error = ENOTCONN;
7167 				iocp->ioc_count = 0;
7168 				mp->b_datap->db_type = M_IOCACK;
7169 				putnext(UDP_RD(q), mp);
7170 				TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7171 					"udp_wput_other_end: q %p (%S)",
7172 					q, "getpeername");
7173 				return;
7174 			}
7175 			/* FALLTHRU */
7176 		case TI_GETMYNAME: {
7177 			/*
7178 			 * For TI_GETPEERNAME and TI_GETMYNAME, we first
7179 			 * need to copyin the user's strbuf structure.
7180 			 * Processing will continue in the M_IOCDATA case
7181 			 * below.
7182 			 */
7183 			mi_copyin(q, mp, NULL,
7184 			    SIZEOF_STRUCT(strbuf, iocp->ioc_flag));
7185 			TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7186 				"udp_wput_other_end: q %p (%S)",
7187 				q, "getmyname");
7188 			return;
7189 			}
7190 		case ND_SET:
7191 			/* nd_getset performs the necessary checking */
7192 		case ND_GET:
7193 			if (nd_getset(q, udp_g_nd, mp)) {
7194 				putnext(UDP_RD(q), mp);
7195 				TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7196 					"udp_wput_other_end: q %p (%S)",
7197 					q, "get");
7198 				return;
7199 			}
7200 			break;
7201 		case _SIOCSOCKFALLBACK:
7202 			/*
7203 			 * Either sockmod is about to be popped and the
7204 			 * socket would now be treated as a plain stream,
7205 			 * or a module is about to be pushed so we could
7206 			 * no longer use read-side synchronous stream.
7207 			 * Drain any queued data and disable direct sockfs
7208 			 * interface from now on.
7209 			 */
7210 			if (!udp->udp_issocket) {
7211 				DB_TYPE(mp) = M_IOCNAK;
7212 				iocp->ioc_error = EINVAL;
7213 			} else {
7214 				udp->udp_issocket = B_FALSE;
7215 				if (udp->udp_direct_sockfs) {
7216 					/*
7217 					 * Disable read-side synchronous
7218 					 * stream interface and drain any
7219 					 * queued data.
7220 					 */
7221 					udp_rcv_drain(UDP_RD(q), udp,
7222 					    B_FALSE);
7223 					ASSERT(!udp->udp_direct_sockfs);
7224 					UDP_STAT(udp_sock_fallback);
7225 				}
7226 				DB_TYPE(mp) = M_IOCACK;
7227 				iocp->ioc_error = 0;
7228 			}
7229 			iocp->ioc_count = 0;
7230 			iocp->ioc_rval = 0;
7231 			putnext(UDP_RD(q), mp);
7232 			return;
7233 		default:
7234 			break;
7235 		}
7236 		break;
7237 	case M_IOCDATA:
7238 		udp_wput_iocdata(q, mp);
7239 		TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7240 			"udp_wput_other_end: q %p (%S)", q, "iocdata");
7241 		return;
7242 	default:
7243 		/* Unrecognized messages are passed through without change. */
7244 		break;
7245 	}
7246 	TRACE_2(TR_FAC_UDP, TR_UDP_WPUT_OTHER_END,
7247 		"udp_wput_other_end: q %p (%S)", q, "end");
7248 	ip_output(connp, mp, q, IP_WPUT);
7249 }
7250 
7251 /* ARGSUSED */
7252 static void
7253 udp_wput_other_wrapper(void *arg, mblk_t *mp, void *arg2)
7254 {
7255 	udp_wput_other(((conn_t *)arg)->conn_wq, mp);
7256 	udp_exit((conn_t *)arg);
7257 }
7258 
7259 /*
7260  * udp_wput_iocdata is called by udp_wput_other to handle all M_IOCDATA
7261  * messages.
7262  */
7263 static void
7264 udp_wput_iocdata(queue_t *q, mblk_t *mp)
7265 {
7266 	mblk_t	*mp1;
7267 	STRUCT_HANDLE(strbuf, sb);
7268 	uint16_t port;
7269 	in6_addr_t	v6addr;
7270 	ipaddr_t	v4addr;
7271 	uint32_t	flowinfo = 0;
7272 	int		addrlen;
7273 	udp_t		*udp = Q_TO_UDP(q);
7274 
7275 	/* Make sure it is one of ours. */
7276 	switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
7277 	case TI_GETMYNAME:
7278 	case TI_GETPEERNAME:
7279 		break;
7280 	default:
7281 		ip_output(Q_TO_CONN(q), mp, q, IP_WPUT);
7282 		return;
7283 	}
7284 
7285 	q = WR(UDP_RD(q));
7286 	switch (mi_copy_state(q, mp, &mp1)) {
7287 	case -1:
7288 		return;
7289 	case MI_COPY_CASE(MI_COPY_IN, 1):
7290 		break;
7291 	case MI_COPY_CASE(MI_COPY_OUT, 1):
7292 		/*
7293 		 * The address has been copied out, so now
7294 		 * copyout the strbuf.
7295 		 */
7296 		mi_copyout(q, mp);
7297 		return;
7298 	case MI_COPY_CASE(MI_COPY_OUT, 2):
7299 		/*
7300 		 * The address and strbuf have been copied out.
7301 		 * We're done, so just acknowledge the original
7302 		 * M_IOCTL.
7303 		 */
7304 		mi_copy_done(q, mp, 0);
7305 		return;
7306 	default:
7307 		/*
7308 		 * Something strange has happened, so acknowledge
7309 		 * the original M_IOCTL with an EPROTO error.
7310 		 */
7311 		mi_copy_done(q, mp, EPROTO);
7312 		return;
7313 	}
7314 
7315 	/*
7316 	 * Now we have the strbuf structure for TI_GETMYNAME
7317 	 * and TI_GETPEERNAME.  Next we copyout the requested
7318 	 * address and then we'll copyout the strbuf.
7319 	 */
7320 	STRUCT_SET_HANDLE(sb, ((struct iocblk *)mp->b_rptr)->ioc_flag,
7321 	    (void *)mp1->b_rptr);
7322 	if (udp->udp_family == AF_INET)
7323 		addrlen = sizeof (sin_t);
7324 	else
7325 		addrlen = sizeof (sin6_t);
7326 
7327 	if (STRUCT_FGET(sb, maxlen) < addrlen) {
7328 		mi_copy_done(q, mp, EINVAL);
7329 		return;
7330 	}
7331 	switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
7332 	case TI_GETMYNAME:
7333 		if (udp->udp_family == AF_INET) {
7334 			ASSERT(udp->udp_ipversion == IPV4_VERSION);
7335 			if (!IN6_IS_ADDR_V4MAPPED_ANY(&udp->udp_v6src) &&
7336 			    !IN6_IS_ADDR_UNSPECIFIED(&udp->udp_v6src)) {
7337 				v4addr = V4_PART_OF_V6(udp->udp_v6src);
7338 			} else {
7339 				/*
7340 				 * INADDR_ANY
7341 				 * udp_v6src is not set, we might be bound to
7342 				 * broadcast/multicast. Use udp_bound_v6src as
7343 				 * local address instead (that could
7344 				 * also still be INADDR_ANY)
7345 				 */
7346 				v4addr = V4_PART_OF_V6(udp->udp_bound_v6src);
7347 			}
7348 		} else {
7349 			/* udp->udp_family == AF_INET6 */
7350 			if (!IN6_IS_ADDR_UNSPECIFIED(&udp->udp_v6src)) {
7351 				v6addr = udp->udp_v6src;
7352 			} else {
7353 				/*
7354 				 * UNSPECIFIED
7355 				 * udp_v6src is not set, we might be bound to
7356 				 * broadcast/multicast. Use udp_bound_v6src as
7357 				 * local address instead (that could
7358 				 * also still be UNSPECIFIED)
7359 				 */
7360 				v6addr = udp->udp_bound_v6src;
7361 			}
7362 		}
7363 		port = udp->udp_port;
7364 		break;
7365 	case TI_GETPEERNAME:
7366 		if (udp->udp_state != TS_DATA_XFER) {
7367 			mi_copy_done(q, mp, ENOTCONN);
7368 			return;
7369 		}
7370 		if (udp->udp_family == AF_INET) {
7371 			ASSERT(udp->udp_ipversion == IPV4_VERSION);
7372 			v4addr = V4_PART_OF_V6(udp->udp_v6dst);
7373 		} else {
7374 			/* udp->udp_family == AF_INET6) */
7375 			v6addr = udp->udp_v6dst;
7376 			flowinfo = udp->udp_flowinfo;
7377 		}
7378 		port = udp->udp_dstport;
7379 		break;
7380 	default:
7381 		mi_copy_done(q, mp, EPROTO);
7382 		return;
7383 	}
7384 	mp1 = mi_copyout_alloc(q, mp, STRUCT_FGETP(sb, buf), addrlen, B_TRUE);
7385 	if (!mp1)
7386 		return;
7387 
7388 	if (udp->udp_family == AF_INET) {
7389 		sin_t *sin;
7390 
7391 		STRUCT_FSET(sb, len, (int)sizeof (sin_t));
7392 		sin = (sin_t *)mp1->b_rptr;
7393 		mp1->b_wptr = (uchar_t *)&sin[1];
7394 		*sin = sin_null;
7395 		sin->sin_family = AF_INET;
7396 		sin->sin_addr.s_addr = v4addr;
7397 		sin->sin_port = port;
7398 	} else {
7399 		/* udp->udp_family == AF_INET6 */
7400 		sin6_t *sin6;
7401 
7402 		STRUCT_FSET(sb, len, (int)sizeof (sin6_t));
7403 		sin6 = (sin6_t *)mp1->b_rptr;
7404 		mp1->b_wptr = (uchar_t *)&sin6[1];
7405 		*sin6 = sin6_null;
7406 		sin6->sin6_family = AF_INET6;
7407 		sin6->sin6_flowinfo = flowinfo;
7408 		sin6->sin6_addr = v6addr;
7409 		sin6->sin6_port = port;
7410 	}
7411 	/* Copy out the address */
7412 	mi_copyout(q, mp);
7413 }
7414 
7415 
7416 static int
7417 udp_unitdata_opt_process(queue_t *q, mblk_t *mp, int *errorp,
7418     void *thisdg_attrs)
7419 {
7420 	struct T_unitdata_req *udreqp;
7421 	int is_absreq_failure;
7422 	cred_t *cr;
7423 	conn_t	*connp = Q_TO_CONN(q);
7424 
7425 	ASSERT(((t_primp_t)mp->b_rptr)->type);
7426 
7427 	cr = DB_CREDDEF(mp, connp->conn_cred);
7428 
7429 	udreqp = (struct T_unitdata_req *)mp->b_rptr;
7430 	*errorp = 0;
7431 
7432 	/*
7433 	 * Use upper queue for option processing since the callback
7434 	 * routines expect to be called in UDP instance instead of IP.
7435 	 */
7436 	*errorp = tpi_optcom_buf(_WR(UDP_RD(q)), mp, &udreqp->OPT_length,
7437 	    udreqp->OPT_offset, cr, &udp_opt_obj,
7438 	    thisdg_attrs, &is_absreq_failure);
7439 
7440 	if (*errorp != 0) {
7441 		/*
7442 		 * Note: No special action needed in this
7443 		 * module for "is_absreq_failure"
7444 		 */
7445 		return (-1);		/* failure */
7446 	}
7447 	ASSERT(is_absreq_failure == 0);
7448 	return (0);	/* success */
7449 }
7450 
7451 void
7452 udp_ddi_init(void)
7453 {
7454 	int i;
7455 
7456 	UDP6_MAJ = ddi_name_to_major(UDP6);
7457 
7458 	udp_max_optsize = optcom_max_optsize(udp_opt_obj.odb_opt_des_arr,
7459 	    udp_opt_obj.odb_opt_arr_cnt);
7460 
7461 	if (udp_bind_fanout_size & (udp_bind_fanout_size - 1)) {
7462 		/* Not a power of two. Round up to nearest power of two */
7463 		for (i = 0; i < 31; i++) {
7464 			if (udp_bind_fanout_size < (1 << i))
7465 				break;
7466 		}
7467 		udp_bind_fanout_size = 1 << i;
7468 	}
7469 	udp_bind_fanout = kmem_zalloc(udp_bind_fanout_size *
7470 	    sizeof (udp_fanout_t), KM_SLEEP);
7471 	for (i = 0; i < udp_bind_fanout_size; i++) {
7472 		mutex_init(&udp_bind_fanout[i].uf_lock, NULL, MUTEX_DEFAULT,
7473 		    NULL);
7474 	}
7475 	(void) udp_param_register(udp_param_arr, A_CNT(udp_param_arr));
7476 
7477 	udp_kstat_init();
7478 
7479 	udp_cache = kmem_cache_create("udp_cache", sizeof (udp_t),
7480 	    CACHE_ALIGN_SIZE, NULL, NULL, NULL, NULL, NULL, 0);
7481 }
7482 
7483 void
7484 udp_ddi_destroy(void)
7485 {
7486 	int i;
7487 
7488 	nd_free(&udp_g_nd);
7489 
7490 	for (i = 0; i < udp_bind_fanout_size; i++) {
7491 		mutex_destroy(&udp_bind_fanout[i].uf_lock);
7492 	}
7493 
7494 	kmem_free(udp_bind_fanout, udp_bind_fanout_size *
7495 	    sizeof (udp_fanout_t));
7496 
7497 	udp_kstat_fini();
7498 
7499 	kmem_cache_destroy(udp_cache);
7500 }
7501 
7502 static void
7503 udp_kstat_init(void)
7504 {
7505 	udp_named_kstat_t template = {
7506 		{ "inDatagrams",	KSTAT_DATA_UINT32, 0 },
7507 		{ "inErrors",		KSTAT_DATA_UINT32, 0 },
7508 		{ "outDatagrams",	KSTAT_DATA_UINT32, 0 },
7509 		{ "entrySize",		KSTAT_DATA_INT32, 0 },
7510 		{ "entry6Size",		KSTAT_DATA_INT32, 0 },
7511 		{ "outErrors",		KSTAT_DATA_UINT32, 0 },
7512 	};
7513 
7514 	udp_mibkp = kstat_create(UDP_MOD_NAME, 0, UDP_MOD_NAME,
7515 	    "mib2", KSTAT_TYPE_NAMED, NUM_OF_FIELDS(udp_named_kstat_t), 0);
7516 
7517 	if (udp_mibkp == NULL)
7518 		return;
7519 
7520 	template.entrySize.value.ui32 = sizeof (mib2_udpEntry_t);
7521 	template.entry6Size.value.ui32 = sizeof (mib2_udp6Entry_t);
7522 
7523 	bcopy(&template, udp_mibkp->ks_data, sizeof (template));
7524 
7525 	udp_mibkp->ks_update = udp_kstat_update;
7526 
7527 	kstat_install(udp_mibkp);
7528 
7529 	if ((udp_ksp = kstat_create(UDP_MOD_NAME, 0, "udpstat",
7530 	    "net", KSTAT_TYPE_NAMED,
7531 	    sizeof (udp_statistics) / sizeof (kstat_named_t),
7532 	    KSTAT_FLAG_VIRTUAL)) != NULL) {
7533 		udp_ksp->ks_data = &udp_statistics;
7534 		kstat_install(udp_ksp);
7535 	}
7536 }
7537 
7538 static void
7539 udp_kstat_fini(void)
7540 {
7541 	if (udp_ksp != NULL) {
7542 		kstat_delete(udp_ksp);
7543 		udp_ksp = NULL;
7544 	}
7545 	if (udp_mibkp != NULL) {
7546 		kstat_delete(udp_mibkp);
7547 		udp_mibkp = NULL;
7548 	}
7549 }
7550 
7551 static int
7552 udp_kstat_update(kstat_t *kp, int rw)
7553 {
7554 	udp_named_kstat_t *udpkp;
7555 
7556 	if ((kp == NULL) || (kp->ks_data == NULL))
7557 		return (EIO);
7558 
7559 	if (rw == KSTAT_WRITE)
7560 		return (EACCES);
7561 
7562 	udpkp = (udp_named_kstat_t *)kp->ks_data;
7563 
7564 	udpkp->inDatagrams.value.ui32 =	udp_mib.udpInDatagrams;
7565 	udpkp->inErrors.value.ui32 =	udp_mib.udpInErrors;
7566 	udpkp->outDatagrams.value.ui32 = udp_mib.udpOutDatagrams;
7567 	udpkp->outErrors.value.ui32 =	udp_mib.udpOutErrors;
7568 
7569 	return (0);
7570 }
7571 
7572 /* ARGSUSED */
7573 static void
7574 udp_rput(queue_t *q, mblk_t *mp)
7575 {
7576 	/*
7577 	 * We get here whenever we do qreply() from IP,
7578 	 * i.e as part of handlings ioctls, etc.
7579 	 */
7580 	putnext(q, mp);
7581 }
7582 
7583 /*
7584  * Read-side synchronous stream info entry point, called as a
7585  * result of handling certain STREAMS ioctl operations.
7586  */
7587 static int
7588 udp_rinfop(queue_t *q, infod_t *dp)
7589 {
7590 	mblk_t	*mp;
7591 	uint_t	cmd = dp->d_cmd;
7592 	int	res = 0;
7593 	int	error = 0;
7594 	udp_t	*udp = Q_TO_UDP(RD(UDP_WR(q)));
7595 	struct stdata *stp = STREAM(q);
7596 
7597 	mutex_enter(&udp->udp_drain_lock);
7598 	/* If shutdown on read has happened, return nothing */
7599 	mutex_enter(&stp->sd_lock);
7600 	if (stp->sd_flag & STREOF) {
7601 		mutex_exit(&stp->sd_lock);
7602 		goto done;
7603 	}
7604 	mutex_exit(&stp->sd_lock);
7605 
7606 	if ((mp = udp->udp_rcv_list_head) == NULL)
7607 		goto done;
7608 
7609 	ASSERT(DB_TYPE(mp) != M_DATA && mp->b_cont != NULL);
7610 
7611 	if (cmd & INFOD_COUNT) {
7612 		/*
7613 		 * Return the number of messages.
7614 		 */
7615 		dp->d_count += udp->udp_rcv_msgcnt;
7616 		res |= INFOD_COUNT;
7617 	}
7618 	if (cmd & INFOD_BYTES) {
7619 		/*
7620 		 * Return size of all data messages.
7621 		 */
7622 		dp->d_bytes += udp->udp_rcv_cnt;
7623 		res |= INFOD_BYTES;
7624 	}
7625 	if (cmd & INFOD_FIRSTBYTES) {
7626 		/*
7627 		 * Return size of first data message.
7628 		 */
7629 		dp->d_bytes = msgdsize(mp);
7630 		res |= INFOD_FIRSTBYTES;
7631 		dp->d_cmd &= ~INFOD_FIRSTBYTES;
7632 	}
7633 	if (cmd & INFOD_COPYOUT) {
7634 		mblk_t *mp1 = mp->b_cont;
7635 		int n;
7636 		/*
7637 		 * Return data contents of first message.
7638 		 */
7639 		ASSERT(DB_TYPE(mp1) == M_DATA);
7640 		while (mp1 != NULL && dp->d_uiop->uio_resid > 0) {
7641 			n = MIN(dp->d_uiop->uio_resid, MBLKL(mp1));
7642 			if (n != 0 && (error = uiomove((char *)mp1->b_rptr, n,
7643 			    UIO_READ, dp->d_uiop)) != 0) {
7644 				goto done;
7645 			}
7646 			mp1 = mp1->b_cont;
7647 		}
7648 		res |= INFOD_COPYOUT;
7649 		dp->d_cmd &= ~INFOD_COPYOUT;
7650 	}
7651 done:
7652 	mutex_exit(&udp->udp_drain_lock);
7653 
7654 	dp->d_res |= res;
7655 
7656 	return (error);
7657 }
7658 
7659 /*
7660  * Read-side synchronous stream entry point.  This is called as a result
7661  * of recv/read operation done at sockfs, and is guaranteed to execute
7662  * outside of the interrupt thread context.  It returns a single datagram
7663  * (b_cont chain of T_UNITDATA_IND plus data) to the upper layer.
7664  */
7665 static int
7666 udp_rrw(queue_t *q, struiod_t *dp)
7667 {
7668 	mblk_t	*mp;
7669 	udp_t	*udp = Q_TO_UDP(_RD(UDP_WR(q)));
7670 
7671 	/* We should never get here when we're in SNMP mode */
7672 	ASSERT(!(udp->udp_connp->conn_flags & IPCL_UDPMOD));
7673 
7674 	/*
7675 	 * Dequeue datagram from the head of the list and return
7676 	 * it to caller; also ensure that RSLEEP sd_wakeq flag is
7677 	 * set/cleared depending on whether or not there's data
7678 	 * remaining in the list.
7679 	 */
7680 	mutex_enter(&udp->udp_drain_lock);
7681 	if (!udp->udp_direct_sockfs) {
7682 		mutex_exit(&udp->udp_drain_lock);
7683 		UDP_STAT(udp_rrw_busy);
7684 		return (EBUSY);
7685 	}
7686 	if ((mp = udp->udp_rcv_list_head) != NULL) {
7687 		uint_t size = msgdsize(mp);
7688 
7689 		/* Last datagram in the list? */
7690 		if ((udp->udp_rcv_list_head = mp->b_next) == NULL)
7691 			udp->udp_rcv_list_tail = NULL;
7692 		mp->b_next = NULL;
7693 
7694 		udp->udp_rcv_cnt -= size;
7695 		udp->udp_rcv_msgcnt--;
7696 		UDP_STAT(udp_rrw_msgcnt);
7697 
7698 		/* No longer flow-controlling? */
7699 		if (udp->udp_rcv_cnt < udp->udp_rcv_hiwat &&
7700 		    udp->udp_rcv_msgcnt < udp->udp_rcv_hiwat)
7701 			udp->udp_drain_qfull = B_FALSE;
7702 	}
7703 	if (udp->udp_rcv_list_head == NULL) {
7704 		/*
7705 		 * Either we just dequeued the last datagram or
7706 		 * we get here from sockfs and have nothing to
7707 		 * return; in this case clear RSLEEP.
7708 		 */
7709 		ASSERT(udp->udp_rcv_cnt == 0);
7710 		ASSERT(udp->udp_rcv_msgcnt == 0);
7711 		ASSERT(udp->udp_rcv_list_tail == NULL);
7712 		STR_WAKEUP_CLEAR(STREAM(q));
7713 	} else {
7714 		/*
7715 		 * More data follows; we need udp_rrw() to be
7716 		 * called in future to pick up the rest.
7717 		 */
7718 		STR_WAKEUP_SET(STREAM(q));
7719 	}
7720 	mutex_exit(&udp->udp_drain_lock);
7721 	dp->d_mp = mp;
7722 	return (0);
7723 }
7724 
7725 /*
7726  * Enqueue a completely-built T_UNITDATA_IND message into the receive
7727  * list; this is typically executed within the interrupt thread context
7728  * and so we do things as quickly as possible.
7729  */
7730 static void
7731 udp_rcv_enqueue(queue_t *q, udp_t *udp, mblk_t *mp, uint_t pkt_len)
7732 {
7733 	ASSERT(q == RD(q));
7734 	ASSERT(pkt_len == msgdsize(mp));
7735 	ASSERT(mp->b_next == NULL && mp->b_cont != NULL);
7736 	ASSERT(DB_TYPE(mp) == M_PROTO && DB_TYPE(mp->b_cont) == M_DATA);
7737 	ASSERT(MBLKL(mp) >= sizeof (struct T_unitdata_ind));
7738 
7739 	mutex_enter(&udp->udp_drain_lock);
7740 	/*
7741 	 * Wake up and signal the receiving app; it is okay to do this
7742 	 * before enqueueing the mp because we are holding the drain lock.
7743 	 * One of the advantages of synchronous stream is the ability for
7744 	 * us to find out when the application performs a read on the
7745 	 * socket by way of udp_rrw() entry point being called.  We need
7746 	 * to generate SIGPOLL/SIGIO for each received data in the case
7747 	 * of asynchronous socket just as in the strrput() case.  However,
7748 	 * we only wake the application up when necessary, i.e. during the
7749 	 * first enqueue.  When udp_rrw() is called, we send up a single
7750 	 * datagram upstream and call STR_WAKEUP_SET() again when there
7751 	 * are still data remaining in our receive queue.
7752 	 */
7753 	if (udp->udp_rcv_list_head == NULL) {
7754 		STR_WAKEUP_SET(STREAM(q));
7755 		udp->udp_rcv_list_head = mp;
7756 	} else {
7757 		udp->udp_rcv_list_tail->b_next = mp;
7758 	}
7759 	udp->udp_rcv_list_tail = mp;
7760 	udp->udp_rcv_cnt += pkt_len;
7761 	udp->udp_rcv_msgcnt++;
7762 
7763 	/* Need to flow-control? */
7764 	if (udp->udp_rcv_cnt >= udp->udp_rcv_hiwat ||
7765 	    udp->udp_rcv_msgcnt >= udp->udp_rcv_hiwat)
7766 		udp->udp_drain_qfull = B_TRUE;
7767 
7768 	/* Update poll events and send SIGPOLL/SIGIO if necessary */
7769 	STR_SENDSIG(STREAM(q));
7770 	mutex_exit(&udp->udp_drain_lock);
7771 }
7772 
7773 /*
7774  * Drain the contents of receive list to the module upstream; we do
7775  * this during close or when we fallback to the slow mode due to
7776  * sockmod being popped or a module being pushed on top of us.
7777  */
7778 static void
7779 udp_rcv_drain(queue_t *q, udp_t *udp, boolean_t closing)
7780 {
7781 	mblk_t *mp;
7782 
7783 	ASSERT(q == RD(q));
7784 
7785 	mutex_enter(&udp->udp_drain_lock);
7786 	/*
7787 	 * There is no race with a concurrent udp_input() sending
7788 	 * up packets using putnext() after we have cleared the
7789 	 * udp_direct_sockfs flag but before we have completed
7790 	 * sending up the packets in udp_rcv_list, since we are
7791 	 * either a writer or we have quiesced the conn.
7792 	 */
7793 	udp->udp_direct_sockfs = B_FALSE;
7794 	mutex_exit(&udp->udp_drain_lock);
7795 
7796 	if (udp->udp_rcv_list_head != NULL)
7797 		UDP_STAT(udp_drain);
7798 
7799 	/*
7800 	 * Send up everything via putnext(); note here that we
7801 	 * don't need the udp_drain_lock to protect us since
7802 	 * nothing can enter udp_rrw() and that we currently
7803 	 * have exclusive access to this udp.
7804 	 */
7805 	while ((mp = udp->udp_rcv_list_head) != NULL) {
7806 		udp->udp_rcv_list_head = mp->b_next;
7807 		mp->b_next = NULL;
7808 		udp->udp_rcv_cnt -= msgdsize(mp);
7809 		udp->udp_rcv_msgcnt--;
7810 		if (closing) {
7811 			freemsg(mp);
7812 		} else {
7813 			putnext(q, mp);
7814 		}
7815 	}
7816 	ASSERT(udp->udp_rcv_cnt == 0);
7817 	ASSERT(udp->udp_rcv_msgcnt == 0);
7818 	ASSERT(udp->udp_rcv_list_head == NULL);
7819 	udp->udp_rcv_list_tail = NULL;
7820 	udp->udp_drain_qfull = B_FALSE;
7821 }
7822 
7823 static size_t
7824 udp_set_rcv_hiwat(udp_t *udp, size_t size)
7825 {
7826 	/* We add a bit of extra buffering */
7827 	size += size >> 1;
7828 	if (size > udp_max_buf)
7829 		size = udp_max_buf;
7830 
7831 	udp->udp_rcv_hiwat = size;
7832 	return (size);
7833 }
7834 
7835 /*
7836  * Little helper for IPsec's NAT-T processing.
7837  */
7838 boolean_t
7839 udp_compute_checksum(void)
7840 {
7841 	return (udp_do_checksum);
7842 }
7843