xref: /freebsd/sys/netinet/udp_usrreq.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3  *	The Regents of the University of California.
4  * Copyright (c) 2008 Robert N. M. Watson
5  * Copyright (c) 2010-2011 Juniper Networks, Inc.
6  * Copyright (c) 2014 Kevin Lo
7  * All rights reserved.
8  *
9  * Portions of this software were developed by Robert N. M. Watson under
10  * contract to Juniper Networks, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "opt_ipfw.h"
43 #include "opt_inet.h"
44 #include "opt_inet6.h"
45 #include "opt_ipsec.h"
46 #include "opt_rss.h"
47 
48 #include <sys/param.h>
49 #include <sys/domain.h>
50 #include <sys/eventhandler.h>
51 #include <sys/jail.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/malloc.h>
55 #include <sys/mbuf.h>
56 #include <sys/priv.h>
57 #include <sys/proc.h>
58 #include <sys/protosw.h>
59 #include <sys/sdt.h>
60 #include <sys/signalvar.h>
61 #include <sys/socket.h>
62 #include <sys/socketvar.h>
63 #include <sys/sx.h>
64 #include <sys/sysctl.h>
65 #include <sys/syslog.h>
66 #include <sys/systm.h>
67 
68 #include <vm/uma.h>
69 
70 #include <net/if.h>
71 #include <net/if_var.h>
72 #include <net/route.h>
73 #include <net/rss_config.h>
74 
75 #include <netinet/in.h>
76 #include <netinet/in_kdtrace.h>
77 #include <netinet/in_pcb.h>
78 #include <netinet/in_systm.h>
79 #include <netinet/in_var.h>
80 #include <netinet/ip.h>
81 #ifdef INET6
82 #include <netinet/ip6.h>
83 #endif
84 #include <netinet/ip_icmp.h>
85 #include <netinet/icmp_var.h>
86 #include <netinet/ip_var.h>
87 #include <netinet/ip_options.h>
88 #ifdef INET6
89 #include <netinet6/ip6_var.h>
90 #endif
91 #include <netinet/udp.h>
92 #include <netinet/udp_var.h>
93 #include <netinet/udplite.h>
94 #include <netinet/in_rss.h>
95 
96 #ifdef IPSEC
97 #include <netipsec/ipsec.h>
98 #include <netipsec/esp.h>
99 #endif
100 
101 #include <machine/in_cksum.h>
102 
103 #include <security/mac/mac_framework.h>
104 
105 /*
106  * UDP and UDP-Lite protocols implementation.
107  * Per RFC 768, August, 1980.
108  * Per RFC 3828, July, 2004.
109  */
110 
111 /*
112  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
113  * removes the only data integrity mechanism for packets and malformed
114  * packets that would otherwise be discarded due to bad checksums, and may
115  * cause problems (especially for NFS data blocks).
116  */
117 VNET_DEFINE(int, udp_cksum) = 1;
118 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
119     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
120 
121 int	udp_log_in_vain = 0;
122 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
123     &udp_log_in_vain, 0, "Log all incoming UDP packets");
124 
125 VNET_DEFINE(int, udp_blackhole) = 0;
126 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
127     &VNET_NAME(udp_blackhole), 0,
128     "Do not send port unreachables for refused connects");
129 
130 u_long	udp_sendspace = 9216;		/* really max datagram size */
131 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
132     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
133 
134 u_long	udp_recvspace = 40 * (1024 +
135 #ifdef INET6
136 				      sizeof(struct sockaddr_in6)
137 #else
138 				      sizeof(struct sockaddr_in)
139 #endif
140 				      );	/* 40 1K datagrams */
141 
142 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
143     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
144 
145 VNET_DEFINE(struct inpcbhead, udb);		/* from udp_var.h */
146 VNET_DEFINE(struct inpcbinfo, udbinfo);
147 VNET_DEFINE(struct inpcbhead, ulitecb);
148 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
149 static VNET_DEFINE(uma_zone_t, udpcb_zone);
150 #define	V_udpcb_zone			VNET(udpcb_zone)
151 
152 #ifndef UDBHASHSIZE
153 #define	UDBHASHSIZE	128
154 #endif
155 
156 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
157 VNET_PCPUSTAT_SYSINIT(udpstat);
158 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
159     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
160 
161 #ifdef VIMAGE
162 VNET_PCPUSTAT_SYSUNINIT(udpstat);
163 #endif /* VIMAGE */
164 #ifdef INET
165 static void	udp_detach(struct socket *so);
166 static int	udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
167 		    struct mbuf *, struct thread *);
168 #endif
169 
170 #ifdef IPSEC
171 #ifdef IPSEC_NAT_T
172 #define	UF_ESPINUDP_ALL	(UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
173 #ifdef INET
174 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
175 #endif
176 #endif /* IPSEC_NAT_T */
177 #endif /* IPSEC */
178 
179 static void
180 udp_zone_change(void *tag)
181 {
182 
183 	uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
184 	uma_zone_set_max(V_udpcb_zone, maxsockets);
185 }
186 
187 static int
188 udp_inpcb_init(void *mem, int size, int flags)
189 {
190 	struct inpcb *inp;
191 
192 	inp = mem;
193 	INP_LOCK_INIT(inp, "inp", "udpinp");
194 	return (0);
195 }
196 
197 static int
198 udplite_inpcb_init(void *mem, int size, int flags)
199 {
200 	struct inpcb *inp;
201 
202 	inp = mem;
203 	INP_LOCK_INIT(inp, "inp", "udpliteinp");
204 	return (0);
205 }
206 
207 void
208 udp_init(void)
209 {
210 
211 	/*
212 	 * For now default to 2-tuple UDP hashing - until the fragment
213 	 * reassembly code can also update the flowid.
214 	 *
215 	 * Once we can calculate the flowid that way and re-establish
216 	 * a 4-tuple, flip this to 4-tuple.
217 	 */
218 	in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
219 	    "udp_inpcb", udp_inpcb_init, NULL, 0,
220 	    IPI_HASHFIELDS_2TUPLE);
221 	V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
222 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
223 	uma_zone_set_max(V_udpcb_zone, maxsockets);
224 	uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
225 	EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
226 	    EVENTHANDLER_PRI_ANY);
227 }
228 
229 void
230 udplite_init(void)
231 {
232 
233 	in_pcbinfo_init(&V_ulitecbinfo, "udplite", &V_ulitecb, UDBHASHSIZE,
234 	    UDBHASHSIZE, "udplite_inpcb", udplite_inpcb_init, NULL,
235 	    0, IPI_HASHFIELDS_2TUPLE);
236 }
237 
238 /*
239  * Kernel module interface for updating udpstat.  The argument is an index
240  * into udpstat treated as an array of u_long.  While this encodes the
241  * general layout of udpstat into the caller, it doesn't encode its location,
242  * so that future changes to add, for example, per-CPU stats support won't
243  * cause binary compatibility problems for kernel modules.
244  */
245 void
246 kmod_udpstat_inc(int statnum)
247 {
248 
249 	counter_u64_add(VNET(udpstat)[statnum], 1);
250 }
251 
252 int
253 udp_newudpcb(struct inpcb *inp)
254 {
255 	struct udpcb *up;
256 
257 	up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
258 	if (up == NULL)
259 		return (ENOBUFS);
260 	inp->inp_ppcb = up;
261 	return (0);
262 }
263 
264 void
265 udp_discardcb(struct udpcb *up)
266 {
267 
268 	uma_zfree(V_udpcb_zone, up);
269 }
270 
271 #ifdef VIMAGE
272 void
273 udp_destroy(void)
274 {
275 
276 	in_pcbinfo_destroy(&V_udbinfo);
277 	uma_zdestroy(V_udpcb_zone);
278 }
279 
280 void
281 udplite_destroy(void)
282 {
283 
284 	in_pcbinfo_destroy(&V_ulitecbinfo);
285 }
286 #endif
287 
288 #ifdef INET
289 /*
290  * Subroutine of udp_input(), which appends the provided mbuf chain to the
291  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
292  * contains the source address.  If the socket ends up being an IPv6 socket,
293  * udp_append() will convert to a sockaddr_in6 before passing the address
294  * into the socket code.
295  *
296  * In the normal case udp_append() will return 0, indicating that you
297  * must unlock the inp. However if a tunneling protocol is in place we increment
298  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
299  * then decrement the reference count. If the inp_rele returns 1, indicating the
300  * inp is gone, we return that to the caller to tell them *not* to unlock
301  * the inp. In the case of multi-cast this will cause the distribution
302  * to stop (though most tunneling protocols known currently do *not* use
303  * multicast).
304  */
305 static int
306 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
307     struct sockaddr_in *udp_in)
308 {
309 	struct sockaddr *append_sa;
310 	struct socket *so;
311 	struct mbuf *opts = 0;
312 #ifdef INET6
313 	struct sockaddr_in6 udp_in6;
314 #endif
315 	struct udpcb *up;
316 
317 	INP_LOCK_ASSERT(inp);
318 
319 	/*
320 	 * Engage the tunneling protocol.
321 	 */
322 	up = intoudpcb(inp);
323 	if (up->u_tun_func != NULL) {
324 		in_pcbref(inp);
325 		INP_RUNLOCK(inp);
326 		(*up->u_tun_func)(n, off, inp, (struct sockaddr *)udp_in,
327 		    up->u_tun_ctx);
328 		INP_RLOCK(inp);
329 		return (in_pcbrele_rlocked(inp));
330 	}
331 
332 	off += sizeof(struct udphdr);
333 
334 #ifdef IPSEC
335 	/* Check AH/ESP integrity. */
336 	if (ipsec4_in_reject(n, inp)) {
337 		m_freem(n);
338 		return (0);
339 	}
340 #ifdef IPSEC_NAT_T
341 	up = intoudpcb(inp);
342 	KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
343 	if (up->u_flags & UF_ESPINUDP_ALL) {	/* IPSec UDP encaps. */
344 		n = udp4_espdecap(inp, n, off);
345 		if (n == NULL)				/* Consumed. */
346 			return (0);
347 	}
348 #endif /* IPSEC_NAT_T */
349 #endif /* IPSEC */
350 #ifdef MAC
351 	if (mac_inpcb_check_deliver(inp, n) != 0) {
352 		m_freem(n);
353 		return (0);
354 	}
355 #endif /* MAC */
356 	if (inp->inp_flags & INP_CONTROLOPTS ||
357 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
358 #ifdef INET6
359 		if (inp->inp_vflag & INP_IPV6)
360 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
361 		else
362 #endif /* INET6 */
363 			ip_savecontrol(inp, &opts, ip, n);
364 	}
365 #ifdef INET6
366 	if (inp->inp_vflag & INP_IPV6) {
367 		bzero(&udp_in6, sizeof(udp_in6));
368 		udp_in6.sin6_len = sizeof(udp_in6);
369 		udp_in6.sin6_family = AF_INET6;
370 		in6_sin_2_v4mapsin6(udp_in, &udp_in6);
371 		append_sa = (struct sockaddr *)&udp_in6;
372 	} else
373 #endif /* INET6 */
374 		append_sa = (struct sockaddr *)udp_in;
375 	m_adj(n, off);
376 
377 	so = inp->inp_socket;
378 	SOCKBUF_LOCK(&so->so_rcv);
379 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
380 		SOCKBUF_UNLOCK(&so->so_rcv);
381 		m_freem(n);
382 		if (opts)
383 			m_freem(opts);
384 		UDPSTAT_INC(udps_fullsock);
385 	} else
386 		sorwakeup_locked(so);
387 	return (0);
388 }
389 
390 int
391 udp_input(struct mbuf **mp, int *offp, int proto)
392 {
393 	struct ip *ip;
394 	struct udphdr *uh;
395 	struct ifnet *ifp;
396 	struct inpcb *inp;
397 	uint16_t len, ip_len;
398 	struct inpcbinfo *pcbinfo;
399 	struct ip save_ip;
400 	struct sockaddr_in udp_in;
401 	struct mbuf *m;
402 	struct m_tag *fwd_tag;
403 	int cscov_partial, iphlen;
404 
405 	m = *mp;
406 	iphlen = *offp;
407 	ifp = m->m_pkthdr.rcvif;
408 	*mp = NULL;
409 	UDPSTAT_INC(udps_ipackets);
410 
411 	/*
412 	 * Strip IP options, if any; should skip this, make available to
413 	 * user, and use on returned packets, but we don't yet have a way to
414 	 * check the checksum with options still present.
415 	 */
416 	if (iphlen > sizeof (struct ip)) {
417 		ip_stripoptions(m);
418 		iphlen = sizeof(struct ip);
419 	}
420 
421 	/*
422 	 * Get IP and UDP header together in first mbuf.
423 	 */
424 	ip = mtod(m, struct ip *);
425 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
426 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
427 			UDPSTAT_INC(udps_hdrops);
428 			return (IPPROTO_DONE);
429 		}
430 		ip = mtod(m, struct ip *);
431 	}
432 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
433 	cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
434 
435 	/*
436 	 * Destination port of 0 is illegal, based on RFC768.
437 	 */
438 	if (uh->uh_dport == 0)
439 		goto badunlocked;
440 
441 	/*
442 	 * Construct sockaddr format source address.  Stuff source address
443 	 * and datagram in user buffer.
444 	 */
445 	bzero(&udp_in, sizeof(udp_in));
446 	udp_in.sin_len = sizeof(udp_in);
447 	udp_in.sin_family = AF_INET;
448 	udp_in.sin_port = uh->uh_sport;
449 	udp_in.sin_addr = ip->ip_src;
450 
451 	/*
452 	 * Make mbuf data length reflect UDP length.  If not enough data to
453 	 * reflect UDP length, drop.
454 	 */
455 	len = ntohs((u_short)uh->uh_ulen);
456 	ip_len = ntohs(ip->ip_len) - iphlen;
457 	if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
458 		/* Zero means checksum over the complete packet. */
459 		if (len == 0)
460 			len = ip_len;
461 		cscov_partial = 0;
462 	}
463 	if (ip_len != len) {
464 		if (len > ip_len || len < sizeof(struct udphdr)) {
465 			UDPSTAT_INC(udps_badlen);
466 			goto badunlocked;
467 		}
468 		if (proto == IPPROTO_UDP)
469 			m_adj(m, len - ip_len);
470 	}
471 
472 	/*
473 	 * Save a copy of the IP header in case we want restore it for
474 	 * sending an ICMP error message in response.
475 	 */
476 	if (!V_udp_blackhole)
477 		save_ip = *ip;
478 	else
479 		memset(&save_ip, 0, sizeof(save_ip));
480 
481 	/*
482 	 * Checksum extended UDP header and data.
483 	 */
484 	if (uh->uh_sum) {
485 		u_short uh_sum;
486 
487 		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
488 		    !cscov_partial) {
489 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
490 				uh_sum = m->m_pkthdr.csum_data;
491 			else
492 				uh_sum = in_pseudo(ip->ip_src.s_addr,
493 				    ip->ip_dst.s_addr, htonl((u_short)len +
494 				    m->m_pkthdr.csum_data + proto));
495 			uh_sum ^= 0xffff;
496 		} else {
497 			char b[9];
498 
499 			bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
500 			bzero(((struct ipovly *)ip)->ih_x1, 9);
501 			((struct ipovly *)ip)->ih_len = (proto == IPPROTO_UDP) ?
502 			    uh->uh_ulen : htons(ip_len);
503 			uh_sum = in_cksum(m, len + sizeof (struct ip));
504 			bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
505 		}
506 		if (uh_sum) {
507 			UDPSTAT_INC(udps_badsum);
508 			m_freem(m);
509 			return (IPPROTO_DONE);
510 		}
511 	} else {
512 		if (proto == IPPROTO_UDP) {
513 			UDPSTAT_INC(udps_nosum);
514 		} else {
515 			/* UDPLite requires a checksum */
516 			/* XXX: What is the right UDPLite MIB counter here? */
517 			m_freem(m);
518 			return (IPPROTO_DONE);
519 		}
520 	}
521 
522 	pcbinfo = udp_get_inpcbinfo(proto);
523 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
524 	    in_broadcast(ip->ip_dst, ifp)) {
525 		struct inpcb *last;
526 		struct inpcbhead *pcblist;
527 		struct ip_moptions *imo;
528 
529 		INP_INFO_RLOCK(pcbinfo);
530 		pcblist = udp_get_pcblist(proto);
531 		last = NULL;
532 		LIST_FOREACH(inp, pcblist, inp_list) {
533 			if (inp->inp_lport != uh->uh_dport)
534 				continue;
535 #ifdef INET6
536 			if ((inp->inp_vflag & INP_IPV4) == 0)
537 				continue;
538 #endif
539 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
540 			    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
541 				continue;
542 			if (inp->inp_faddr.s_addr != INADDR_ANY &&
543 			    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
544 				continue;
545 			if (inp->inp_fport != 0 &&
546 			    inp->inp_fport != uh->uh_sport)
547 				continue;
548 
549 			INP_RLOCK(inp);
550 
551 			/*
552 			 * XXXRW: Because we weren't holding either the inpcb
553 			 * or the hash lock when we checked for a match
554 			 * before, we should probably recheck now that the
555 			 * inpcb lock is held.
556 			 */
557 
558 			/*
559 			 * Handle socket delivery policy for any-source
560 			 * and source-specific multicast. [RFC3678]
561 			 */
562 			imo = inp->inp_moptions;
563 			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
564 				struct sockaddr_in	 group;
565 				int			 blocked;
566 				if (imo == NULL) {
567 					INP_RUNLOCK(inp);
568 					continue;
569 				}
570 				bzero(&group, sizeof(struct sockaddr_in));
571 				group.sin_len = sizeof(struct sockaddr_in);
572 				group.sin_family = AF_INET;
573 				group.sin_addr = ip->ip_dst;
574 
575 				blocked = imo_multi_filter(imo, ifp,
576 					(struct sockaddr *)&group,
577 					(struct sockaddr *)&udp_in);
578 				if (blocked != MCAST_PASS) {
579 					if (blocked == MCAST_NOTGMEMBER)
580 						IPSTAT_INC(ips_notmember);
581 					if (blocked == MCAST_NOTSMEMBER ||
582 					    blocked == MCAST_MUTED)
583 						UDPSTAT_INC(udps_filtermcast);
584 					INP_RUNLOCK(inp);
585 					continue;
586 				}
587 			}
588 			if (last != NULL) {
589 				struct mbuf *n;
590 
591 				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
592 					UDP_PROBE(receive, NULL, last, ip,
593 					    last, uh);
594 					if (udp_append(last, ip, n, iphlen,
595 						&udp_in)) {
596 						goto inp_lost;
597 					}
598 				}
599 				INP_RUNLOCK(last);
600 			}
601 			last = inp;
602 			/*
603 			 * Don't look for additional matches if this one does
604 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
605 			 * socket options set.  This heuristic avoids
606 			 * searching through all pcbs in the common case of a
607 			 * non-shared port.  It assumes that an application
608 			 * will never clear these options after setting them.
609 			 */
610 			if ((last->inp_socket->so_options &
611 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
612 				break;
613 		}
614 
615 		if (last == NULL) {
616 			/*
617 			 * No matching pcb found; discard datagram.  (No need
618 			 * to send an ICMP Port Unreachable for a broadcast
619 			 * or multicast datgram.)
620 			 */
621 			UDPSTAT_INC(udps_noportbcast);
622 			if (inp)
623 				INP_RUNLOCK(inp);
624 			INP_INFO_RUNLOCK(pcbinfo);
625 			goto badunlocked;
626 		}
627 		UDP_PROBE(receive, NULL, last, ip, last, uh);
628 		if (udp_append(last, ip, m, iphlen, &udp_in) == 0)
629 			INP_RUNLOCK(last);
630 	inp_lost:
631 		INP_INFO_RUNLOCK(pcbinfo);
632 		return (IPPROTO_DONE);
633 	}
634 
635 	/*
636 	 * Locate pcb for datagram.
637 	 */
638 
639 	/*
640 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
641 	 */
642 	if ((m->m_flags & M_IP_NEXTHOP) &&
643 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
644 		struct sockaddr_in *next_hop;
645 
646 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
647 
648 		/*
649 		 * Transparently forwarded. Pretend to be the destination.
650 		 * Already got one like this?
651 		 */
652 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
653 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
654 		if (!inp) {
655 			/*
656 			 * It's new.  Try to find the ambushing socket.
657 			 * Because we've rewritten the destination address,
658 			 * any hardware-generated hash is ignored.
659 			 */
660 			inp = in_pcblookup(pcbinfo, ip->ip_src,
661 			    uh->uh_sport, next_hop->sin_addr,
662 			    next_hop->sin_port ? htons(next_hop->sin_port) :
663 			    uh->uh_dport, INPLOOKUP_WILDCARD |
664 			    INPLOOKUP_RLOCKPCB, ifp);
665 		}
666 		/* Remove the tag from the packet. We don't need it anymore. */
667 		m_tag_delete(m, fwd_tag);
668 		m->m_flags &= ~M_IP_NEXTHOP;
669 	} else
670 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
671 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
672 		    INPLOOKUP_RLOCKPCB, ifp, m);
673 	if (inp == NULL) {
674 		if (udp_log_in_vain) {
675 			char buf[4*sizeof "123"];
676 
677 			strcpy(buf, inet_ntoa(ip->ip_dst));
678 			log(LOG_INFO,
679 			    "Connection attempt to UDP %s:%d from %s:%d\n",
680 			    buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
681 			    ntohs(uh->uh_sport));
682 		}
683 		UDPSTAT_INC(udps_noport);
684 		if (m->m_flags & (M_BCAST | M_MCAST)) {
685 			UDPSTAT_INC(udps_noportbcast);
686 			goto badunlocked;
687 		}
688 		if (V_udp_blackhole)
689 			goto badunlocked;
690 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
691 			goto badunlocked;
692 		*ip = save_ip;
693 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
694 		return (IPPROTO_DONE);
695 	}
696 
697 	/*
698 	 * Check the minimum TTL for socket.
699 	 */
700 	INP_RLOCK_ASSERT(inp);
701 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
702 		INP_RUNLOCK(inp);
703 		m_freem(m);
704 		return (IPPROTO_DONE);
705 	}
706 	if (cscov_partial) {
707 		struct udpcb *up;
708 
709 		up = intoudpcb(inp);
710 		if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
711 			INP_RUNLOCK(inp);
712 			m_freem(m);
713 			return (IPPROTO_DONE);
714 		}
715 	}
716 
717 	UDP_PROBE(receive, NULL, inp, ip, inp, uh);
718 	if (udp_append(inp, ip, m, iphlen, &udp_in) == 0)
719 		INP_RUNLOCK(inp);
720 	return (IPPROTO_DONE);
721 
722 badunlocked:
723 	m_freem(m);
724 	return (IPPROTO_DONE);
725 }
726 #endif /* INET */
727 
728 /*
729  * Notify a udp user of an asynchronous error; just wake up so that they can
730  * collect error status.
731  */
732 struct inpcb *
733 udp_notify(struct inpcb *inp, int errno)
734 {
735 
736 	/*
737 	 * While udp_ctlinput() always calls udp_notify() with a read lock
738 	 * when invoking it directly, in_pcbnotifyall() currently uses write
739 	 * locks due to sharing code with TCP.  For now, accept either a read
740 	 * or a write lock, but a read lock is sufficient.
741 	 */
742 	INP_LOCK_ASSERT(inp);
743 
744 	inp->inp_socket->so_error = errno;
745 	sorwakeup(inp->inp_socket);
746 	sowwakeup(inp->inp_socket);
747 	return (inp);
748 }
749 
750 #ifdef INET
751 static void
752 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
753     struct inpcbinfo *pcbinfo)
754 {
755 	struct ip *ip = vip;
756 	struct udphdr *uh;
757 	struct in_addr faddr;
758 	struct inpcb *inp;
759 
760 	faddr = ((struct sockaddr_in *)sa)->sin_addr;
761 	if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
762 		return;
763 
764 	/*
765 	 * Redirects don't need to be handled up here.
766 	 */
767 	if (PRC_IS_REDIRECT(cmd))
768 		return;
769 
770 	/*
771 	 * Hostdead is ugly because it goes linearly through all PCBs.
772 	 *
773 	 * XXX: We never get this from ICMP, otherwise it makes an excellent
774 	 * DoS attack on machines with many connections.
775 	 */
776 	if (cmd == PRC_HOSTDEAD)
777 		ip = NULL;
778 	else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
779 		return;
780 	if (ip != NULL) {
781 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
782 		inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
783 		    ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
784 		if (inp != NULL) {
785 			INP_RLOCK_ASSERT(inp);
786 			if (inp->inp_socket != NULL) {
787 				udp_notify(inp, inetctlerrmap[cmd]);
788 			}
789 			INP_RUNLOCK(inp);
790 		}
791 	} else
792 		in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
793 		    udp_notify);
794 }
795 void
796 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
797 {
798 
799 	return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
800 }
801 
802 void
803 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
804 {
805 
806 	return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
807 }
808 #endif /* INET */
809 
810 static int
811 udp_pcblist(SYSCTL_HANDLER_ARGS)
812 {
813 	int error, i, n;
814 	struct inpcb *inp, **inp_list;
815 	inp_gen_t gencnt;
816 	struct xinpgen xig;
817 
818 	/*
819 	 * The process of preparing the PCB list is too time-consuming and
820 	 * resource-intensive to repeat twice on every request.
821 	 */
822 	if (req->oldptr == 0) {
823 		n = V_udbinfo.ipi_count;
824 		n += imax(n / 8, 10);
825 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
826 		return (0);
827 	}
828 
829 	if (req->newptr != 0)
830 		return (EPERM);
831 
832 	/*
833 	 * OK, now we're committed to doing something.
834 	 */
835 	INP_INFO_RLOCK(&V_udbinfo);
836 	gencnt = V_udbinfo.ipi_gencnt;
837 	n = V_udbinfo.ipi_count;
838 	INP_INFO_RUNLOCK(&V_udbinfo);
839 
840 	error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
841 		+ n * sizeof(struct xinpcb));
842 	if (error != 0)
843 		return (error);
844 
845 	xig.xig_len = sizeof xig;
846 	xig.xig_count = n;
847 	xig.xig_gen = gencnt;
848 	xig.xig_sogen = so_gencnt;
849 	error = SYSCTL_OUT(req, &xig, sizeof xig);
850 	if (error)
851 		return (error);
852 
853 	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
854 	if (inp_list == 0)
855 		return (ENOMEM);
856 
857 	INP_INFO_RLOCK(&V_udbinfo);
858 	for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
859 	     inp = LIST_NEXT(inp, inp_list)) {
860 		INP_WLOCK(inp);
861 		if (inp->inp_gencnt <= gencnt &&
862 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
863 			in_pcbref(inp);
864 			inp_list[i++] = inp;
865 		}
866 		INP_WUNLOCK(inp);
867 	}
868 	INP_INFO_RUNLOCK(&V_udbinfo);
869 	n = i;
870 
871 	error = 0;
872 	for (i = 0; i < n; i++) {
873 		inp = inp_list[i];
874 		INP_RLOCK(inp);
875 		if (inp->inp_gencnt <= gencnt) {
876 			struct xinpcb xi;
877 
878 			bzero(&xi, sizeof(xi));
879 			xi.xi_len = sizeof xi;
880 			/* XXX should avoid extra copy */
881 			bcopy(inp, &xi.xi_inp, sizeof *inp);
882 			if (inp->inp_socket)
883 				sotoxsocket(inp->inp_socket, &xi.xi_socket);
884 			xi.xi_inp.inp_gencnt = inp->inp_gencnt;
885 			INP_RUNLOCK(inp);
886 			error = SYSCTL_OUT(req, &xi, sizeof xi);
887 		} else
888 			INP_RUNLOCK(inp);
889 	}
890 	INP_INFO_WLOCK(&V_udbinfo);
891 	for (i = 0; i < n; i++) {
892 		inp = inp_list[i];
893 		INP_RLOCK(inp);
894 		if (!in_pcbrele_rlocked(inp))
895 			INP_RUNLOCK(inp);
896 	}
897 	INP_INFO_WUNLOCK(&V_udbinfo);
898 
899 	if (!error) {
900 		/*
901 		 * Give the user an updated idea of our state.  If the
902 		 * generation differs from what we told her before, she knows
903 		 * that something happened while we were processing this
904 		 * request, and it might be necessary to retry.
905 		 */
906 		INP_INFO_RLOCK(&V_udbinfo);
907 		xig.xig_gen = V_udbinfo.ipi_gencnt;
908 		xig.xig_sogen = so_gencnt;
909 		xig.xig_count = V_udbinfo.ipi_count;
910 		INP_INFO_RUNLOCK(&V_udbinfo);
911 		error = SYSCTL_OUT(req, &xig, sizeof xig);
912 	}
913 	free(inp_list, M_TEMP);
914 	return (error);
915 }
916 
917 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
918     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
919     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
920 
921 #ifdef INET
922 static int
923 udp_getcred(SYSCTL_HANDLER_ARGS)
924 {
925 	struct xucred xuc;
926 	struct sockaddr_in addrs[2];
927 	struct inpcb *inp;
928 	int error;
929 
930 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
931 	if (error)
932 		return (error);
933 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
934 	if (error)
935 		return (error);
936 	inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
937 	    addrs[0].sin_addr, addrs[0].sin_port,
938 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
939 	if (inp != NULL) {
940 		INP_RLOCK_ASSERT(inp);
941 		if (inp->inp_socket == NULL)
942 			error = ENOENT;
943 		if (error == 0)
944 			error = cr_canseeinpcb(req->td->td_ucred, inp);
945 		if (error == 0)
946 			cru2x(inp->inp_cred, &xuc);
947 		INP_RUNLOCK(inp);
948 	} else
949 		error = ENOENT;
950 	if (error == 0)
951 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
952 	return (error);
953 }
954 
955 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
956     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
957     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
958 #endif /* INET */
959 
960 int
961 udp_ctloutput(struct socket *so, struct sockopt *sopt)
962 {
963 	struct inpcb *inp;
964 	struct udpcb *up;
965 	int isudplite, error, optval;
966 
967 	error = 0;
968 	isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
969 	inp = sotoinpcb(so);
970 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
971 	INP_WLOCK(inp);
972 	if (sopt->sopt_level != so->so_proto->pr_protocol) {
973 #ifdef INET6
974 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
975 			INP_WUNLOCK(inp);
976 			error = ip6_ctloutput(so, sopt);
977 		}
978 #endif
979 #if defined(INET) && defined(INET6)
980 		else
981 #endif
982 #ifdef INET
983 		{
984 			INP_WUNLOCK(inp);
985 			error = ip_ctloutput(so, sopt);
986 		}
987 #endif
988 		return (error);
989 	}
990 
991 	switch (sopt->sopt_dir) {
992 	case SOPT_SET:
993 		switch (sopt->sopt_name) {
994 		case UDP_ENCAP:
995 			INP_WUNLOCK(inp);
996 			error = sooptcopyin(sopt, &optval, sizeof optval,
997 					    sizeof optval);
998 			if (error)
999 				break;
1000 			inp = sotoinpcb(so);
1001 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1002 			INP_WLOCK(inp);
1003 #ifdef IPSEC_NAT_T
1004 			up = intoudpcb(inp);
1005 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1006 #endif
1007 			switch (optval) {
1008 			case 0:
1009 				/* Clear all UDP encap. */
1010 #ifdef IPSEC_NAT_T
1011 				up->u_flags &= ~UF_ESPINUDP_ALL;
1012 #endif
1013 				break;
1014 #ifdef IPSEC_NAT_T
1015 			case UDP_ENCAP_ESPINUDP:
1016 			case UDP_ENCAP_ESPINUDP_NON_IKE:
1017 				up->u_flags &= ~UF_ESPINUDP_ALL;
1018 				if (optval == UDP_ENCAP_ESPINUDP)
1019 					up->u_flags |= UF_ESPINUDP;
1020 				else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
1021 					up->u_flags |= UF_ESPINUDP_NON_IKE;
1022 				break;
1023 #endif
1024 			default:
1025 				error = EINVAL;
1026 				break;
1027 			}
1028 			INP_WUNLOCK(inp);
1029 			break;
1030 		case UDPLITE_SEND_CSCOV:
1031 		case UDPLITE_RECV_CSCOV:
1032 			if (!isudplite) {
1033 				INP_WUNLOCK(inp);
1034 				error = ENOPROTOOPT;
1035 				break;
1036 			}
1037 			INP_WUNLOCK(inp);
1038 			error = sooptcopyin(sopt, &optval, sizeof(optval),
1039 			    sizeof(optval));
1040 			if (error != 0)
1041 				break;
1042 			inp = sotoinpcb(so);
1043 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1044 			INP_WLOCK(inp);
1045 			up = intoudpcb(inp);
1046 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1047 			if ((optval != 0 && optval < 8) || (optval > 65535)) {
1048 				INP_WUNLOCK(inp);
1049 				error = EINVAL;
1050 				break;
1051 			}
1052 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1053 				up->u_txcslen = optval;
1054 			else
1055 				up->u_rxcslen = optval;
1056 			INP_WUNLOCK(inp);
1057 			break;
1058 		default:
1059 			INP_WUNLOCK(inp);
1060 			error = ENOPROTOOPT;
1061 			break;
1062 		}
1063 		break;
1064 	case SOPT_GET:
1065 		switch (sopt->sopt_name) {
1066 #ifdef IPSEC_NAT_T
1067 		case UDP_ENCAP:
1068 			up = intoudpcb(inp);
1069 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1070 			optval = up->u_flags & UF_ESPINUDP_ALL;
1071 			INP_WUNLOCK(inp);
1072 			error = sooptcopyout(sopt, &optval, sizeof optval);
1073 			break;
1074 #endif
1075 		case UDPLITE_SEND_CSCOV:
1076 		case UDPLITE_RECV_CSCOV:
1077 			if (!isudplite) {
1078 				INP_WUNLOCK(inp);
1079 				error = ENOPROTOOPT;
1080 				break;
1081 			}
1082 			up = intoudpcb(inp);
1083 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1084 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1085 				optval = up->u_txcslen;
1086 			else
1087 				optval = up->u_rxcslen;
1088 			INP_WUNLOCK(inp);
1089 			error = sooptcopyout(sopt, &optval, sizeof(optval));
1090 			break;
1091 		default:
1092 			INP_WUNLOCK(inp);
1093 			error = ENOPROTOOPT;
1094 			break;
1095 		}
1096 		break;
1097 	}
1098 	return (error);
1099 }
1100 
1101 #ifdef INET
1102 #define	UH_WLOCKED	2
1103 #define	UH_RLOCKED	1
1104 #define	UH_UNLOCKED	0
1105 static int
1106 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
1107     struct mbuf *control, struct thread *td)
1108 {
1109 	struct udpiphdr *ui;
1110 	int len = m->m_pkthdr.len;
1111 	struct in_addr faddr, laddr;
1112 	struct cmsghdr *cm;
1113 	struct inpcbinfo *pcbinfo;
1114 	struct sockaddr_in *sin, src;
1115 	int cscov_partial = 0;
1116 	int error = 0;
1117 	int ipflags;
1118 	u_short fport, lport;
1119 	int unlock_udbinfo;
1120 	u_char tos;
1121 	uint8_t pr;
1122 	uint16_t cscov = 0;
1123 	uint32_t flowid = 0;
1124 	uint8_t flowtype = M_HASHTYPE_NONE;
1125 
1126 	/*
1127 	 * udp_output() may need to temporarily bind or connect the current
1128 	 * inpcb.  As such, we don't know up front whether we will need the
1129 	 * pcbinfo lock or not.  Do any work to decide what is needed up
1130 	 * front before acquiring any locks.
1131 	 */
1132 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1133 		if (control)
1134 			m_freem(control);
1135 		m_freem(m);
1136 		return (EMSGSIZE);
1137 	}
1138 
1139 	src.sin_family = 0;
1140 	INP_RLOCK(inp);
1141 	tos = inp->inp_ip_tos;
1142 	if (control != NULL) {
1143 		/*
1144 		 * XXX: Currently, we assume all the optional information is
1145 		 * stored in a single mbuf.
1146 		 */
1147 		if (control->m_next) {
1148 			INP_RUNLOCK(inp);
1149 			m_freem(control);
1150 			m_freem(m);
1151 			return (EINVAL);
1152 		}
1153 		for (; control->m_len > 0;
1154 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
1155 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1156 			cm = mtod(control, struct cmsghdr *);
1157 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1158 			    || cm->cmsg_len > control->m_len) {
1159 				error = EINVAL;
1160 				break;
1161 			}
1162 			if (cm->cmsg_level != IPPROTO_IP)
1163 				continue;
1164 
1165 			switch (cm->cmsg_type) {
1166 			case IP_SENDSRCADDR:
1167 				if (cm->cmsg_len !=
1168 				    CMSG_LEN(sizeof(struct in_addr))) {
1169 					error = EINVAL;
1170 					break;
1171 				}
1172 				bzero(&src, sizeof(src));
1173 				src.sin_family = AF_INET;
1174 				src.sin_len = sizeof(src);
1175 				src.sin_port = inp->inp_lport;
1176 				src.sin_addr =
1177 				    *(struct in_addr *)CMSG_DATA(cm);
1178 				break;
1179 
1180 			case IP_TOS:
1181 				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1182 					error = EINVAL;
1183 					break;
1184 				}
1185 				tos = *(u_char *)CMSG_DATA(cm);
1186 				break;
1187 
1188 			case IP_FLOWID:
1189 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1190 					error = EINVAL;
1191 					break;
1192 				}
1193 				flowid = *(uint32_t *) CMSG_DATA(cm);
1194 				break;
1195 
1196 			case IP_FLOWTYPE:
1197 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1198 					error = EINVAL;
1199 					break;
1200 				}
1201 				flowtype = *(uint32_t *) CMSG_DATA(cm);
1202 				break;
1203 
1204 #ifdef	RSS
1205 			case IP_RSSBUCKETID:
1206 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1207 					error = EINVAL;
1208 					break;
1209 				}
1210 				/* This is just a placeholder for now */
1211 				break;
1212 #endif	/* RSS */
1213 			default:
1214 				error = ENOPROTOOPT;
1215 				break;
1216 			}
1217 			if (error)
1218 				break;
1219 		}
1220 		m_freem(control);
1221 	}
1222 	if (error) {
1223 		INP_RUNLOCK(inp);
1224 		m_freem(m);
1225 		return (error);
1226 	}
1227 
1228 	/*
1229 	 * Depending on whether or not the application has bound or connected
1230 	 * the socket, we may have to do varying levels of work.  The optimal
1231 	 * case is for a connected UDP socket, as a global lock isn't
1232 	 * required at all.
1233 	 *
1234 	 * In order to decide which we need, we require stability of the
1235 	 * inpcb binding, which we ensure by acquiring a read lock on the
1236 	 * inpcb.  This doesn't strictly follow the lock order, so we play
1237 	 * the trylock and retry game; note that we may end up with more
1238 	 * conservative locks than required the second time around, so later
1239 	 * assertions have to accept that.  Further analysis of the number of
1240 	 * misses under contention is required.
1241 	 *
1242 	 * XXXRW: Check that hash locking update here is correct.
1243 	 */
1244 	pr = inp->inp_socket->so_proto->pr_protocol;
1245 	pcbinfo = udp_get_inpcbinfo(pr);
1246 	sin = (struct sockaddr_in *)addr;
1247 	if (sin != NULL &&
1248 	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1249 		INP_RUNLOCK(inp);
1250 		INP_WLOCK(inp);
1251 		INP_HASH_WLOCK(pcbinfo);
1252 		unlock_udbinfo = UH_WLOCKED;
1253 	} else if ((sin != NULL && (
1254 	    (sin->sin_addr.s_addr == INADDR_ANY) ||
1255 	    (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1256 	    (inp->inp_laddr.s_addr == INADDR_ANY) ||
1257 	    (inp->inp_lport == 0))) ||
1258 	    (src.sin_family == AF_INET)) {
1259 		INP_HASH_RLOCK(pcbinfo);
1260 		unlock_udbinfo = UH_RLOCKED;
1261 	} else
1262 		unlock_udbinfo = UH_UNLOCKED;
1263 
1264 	/*
1265 	 * If the IP_SENDSRCADDR control message was specified, override the
1266 	 * source address for this datagram.  Its use is invalidated if the
1267 	 * address thus specified is incomplete or clobbers other inpcbs.
1268 	 */
1269 	laddr = inp->inp_laddr;
1270 	lport = inp->inp_lport;
1271 	if (src.sin_family == AF_INET) {
1272 		INP_HASH_LOCK_ASSERT(pcbinfo);
1273 		if ((lport == 0) ||
1274 		    (laddr.s_addr == INADDR_ANY &&
1275 		     src.sin_addr.s_addr == INADDR_ANY)) {
1276 			error = EINVAL;
1277 			goto release;
1278 		}
1279 		error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1280 		    &laddr.s_addr, &lport, td->td_ucred);
1281 		if (error)
1282 			goto release;
1283 	}
1284 
1285 	/*
1286 	 * If a UDP socket has been connected, then a local address/port will
1287 	 * have been selected and bound.
1288 	 *
1289 	 * If a UDP socket has not been connected to, then an explicit
1290 	 * destination address must be used, in which case a local
1291 	 * address/port may not have been selected and bound.
1292 	 */
1293 	if (sin != NULL) {
1294 		INP_LOCK_ASSERT(inp);
1295 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1296 			error = EISCONN;
1297 			goto release;
1298 		}
1299 
1300 		/*
1301 		 * Jail may rewrite the destination address, so let it do
1302 		 * that before we use it.
1303 		 */
1304 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1305 		if (error)
1306 			goto release;
1307 
1308 		/*
1309 		 * If a local address or port hasn't yet been selected, or if
1310 		 * the destination address needs to be rewritten due to using
1311 		 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1312 		 * to do the heavy lifting.  Once a port is selected, we
1313 		 * commit the binding back to the socket; we also commit the
1314 		 * binding of the address if in jail.
1315 		 *
1316 		 * If we already have a valid binding and we're not
1317 		 * requesting a destination address rewrite, use a fast path.
1318 		 */
1319 		if (inp->inp_laddr.s_addr == INADDR_ANY ||
1320 		    inp->inp_lport == 0 ||
1321 		    sin->sin_addr.s_addr == INADDR_ANY ||
1322 		    sin->sin_addr.s_addr == INADDR_BROADCAST) {
1323 			INP_HASH_LOCK_ASSERT(pcbinfo);
1324 			error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1325 			    &lport, &faddr.s_addr, &fport, NULL,
1326 			    td->td_ucred);
1327 			if (error)
1328 				goto release;
1329 
1330 			/*
1331 			 * XXXRW: Why not commit the port if the address is
1332 			 * !INADDR_ANY?
1333 			 */
1334 			/* Commit the local port if newly assigned. */
1335 			if (inp->inp_laddr.s_addr == INADDR_ANY &&
1336 			    inp->inp_lport == 0) {
1337 				INP_WLOCK_ASSERT(inp);
1338 				INP_HASH_WLOCK_ASSERT(pcbinfo);
1339 				/*
1340 				 * Remember addr if jailed, to prevent
1341 				 * rebinding.
1342 				 */
1343 				if (prison_flag(td->td_ucred, PR_IP4))
1344 					inp->inp_laddr = laddr;
1345 				inp->inp_lport = lport;
1346 				if (in_pcbinshash(inp) != 0) {
1347 					inp->inp_lport = 0;
1348 					error = EAGAIN;
1349 					goto release;
1350 				}
1351 				inp->inp_flags |= INP_ANONPORT;
1352 			}
1353 		} else {
1354 			faddr = sin->sin_addr;
1355 			fport = sin->sin_port;
1356 		}
1357 	} else {
1358 		INP_LOCK_ASSERT(inp);
1359 		faddr = inp->inp_faddr;
1360 		fport = inp->inp_fport;
1361 		if (faddr.s_addr == INADDR_ANY) {
1362 			error = ENOTCONN;
1363 			goto release;
1364 		}
1365 	}
1366 
1367 	/*
1368 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1369 	 * link-layer headers.  Immediate slide the data pointer back forward
1370 	 * since we won't use that space at this layer.
1371 	 */
1372 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1373 	if (m == NULL) {
1374 		error = ENOBUFS;
1375 		goto release;
1376 	}
1377 	m->m_data += max_linkhdr;
1378 	m->m_len -= max_linkhdr;
1379 	m->m_pkthdr.len -= max_linkhdr;
1380 
1381 	/*
1382 	 * Fill in mbuf with extended UDP header and addresses and length put
1383 	 * into network format.
1384 	 */
1385 	ui = mtod(m, struct udpiphdr *);
1386 	bzero(ui->ui_x1, sizeof(ui->ui_x1));	/* XXX still needed? */
1387 	ui->ui_pr = pr;
1388 	ui->ui_src = laddr;
1389 	ui->ui_dst = faddr;
1390 	ui->ui_sport = lport;
1391 	ui->ui_dport = fport;
1392 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1393 	if (pr == IPPROTO_UDPLITE) {
1394 		struct udpcb *up;
1395 		uint16_t plen;
1396 
1397 		up = intoudpcb(inp);
1398 		cscov = up->u_txcslen;
1399 		plen = (u_short)len + sizeof(struct udphdr);
1400 		if (cscov >= plen)
1401 			cscov = 0;
1402 		ui->ui_len = htons(plen);
1403 		ui->ui_ulen = htons(cscov);
1404 		/*
1405 		 * For UDP-Lite, checksum coverage length of zero means
1406 		 * the entire UDPLite packet is covered by the checksum.
1407 		 */
1408 		cscov_partial = (cscov == 0) ? 0 : 1;
1409 	} else
1410 		ui->ui_v = IPVERSION << 4;
1411 
1412 	/*
1413 	 * Set the Don't Fragment bit in the IP header.
1414 	 */
1415 	if (inp->inp_flags & INP_DONTFRAG) {
1416 		struct ip *ip;
1417 
1418 		ip = (struct ip *)&ui->ui_i;
1419 		ip->ip_off |= htons(IP_DF);
1420 	}
1421 
1422 	ipflags = 0;
1423 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1424 		ipflags |= IP_ROUTETOIF;
1425 	if (inp->inp_socket->so_options & SO_BROADCAST)
1426 		ipflags |= IP_ALLOWBROADCAST;
1427 	if (inp->inp_flags & INP_ONESBCAST)
1428 		ipflags |= IP_SENDONES;
1429 
1430 #ifdef MAC
1431 	mac_inpcb_create_mbuf(inp, m);
1432 #endif
1433 
1434 	/*
1435 	 * Set up checksum and output datagram.
1436 	 */
1437 	ui->ui_sum = 0;
1438 	if (pr == IPPROTO_UDPLITE) {
1439 		if (inp->inp_flags & INP_ONESBCAST)
1440 			faddr.s_addr = INADDR_BROADCAST;
1441 		if (cscov_partial) {
1442 			if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1443 				ui->ui_sum = 0xffff;
1444 		} else {
1445 			if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1446 				ui->ui_sum = 0xffff;
1447 		}
1448 	} else if (V_udp_cksum) {
1449 		if (inp->inp_flags & INP_ONESBCAST)
1450 			faddr.s_addr = INADDR_BROADCAST;
1451 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1452 		    htons((u_short)len + sizeof(struct udphdr) + pr));
1453 		m->m_pkthdr.csum_flags = CSUM_UDP;
1454 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1455 	}
1456 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1457 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
1458 	((struct ip *)ui)->ip_tos = tos;		/* XXX */
1459 	UDPSTAT_INC(udps_opackets);
1460 
1461 	/*
1462 	 * Setup flowid / RSS information for outbound socket.
1463 	 *
1464 	 * Once the UDP code decides to set a flowid some other way,
1465 	 * this allows the flowid to be overridden by userland.
1466 	 */
1467 	if (flowtype != M_HASHTYPE_NONE) {
1468 		m->m_pkthdr.flowid = flowid;
1469 		M_HASHTYPE_SET(m, flowtype);
1470 #ifdef	RSS
1471 	} else {
1472 		uint32_t hash_val, hash_type;
1473 		/*
1474 		 * Calculate an appropriate RSS hash for UDP and
1475 		 * UDP Lite.
1476 		 *
1477 		 * The called function will take care of figuring out
1478 		 * whether a 2-tuple or 4-tuple hash is required based
1479 		 * on the currently configured scheme.
1480 		 *
1481 		 * Later later on connected socket values should be
1482 		 * cached in the inpcb and reused, rather than constantly
1483 		 * re-calculating it.
1484 		 *
1485 		 * UDP Lite is a different protocol number and will
1486 		 * likely end up being hashed as a 2-tuple until
1487 		 * RSS / NICs grow UDP Lite protocol awareness.
1488 		 */
1489 		if (rss_proto_software_hash_v4(faddr, laddr, fport, lport,
1490 		    pr, &hash_val, &hash_type) == 0) {
1491 			m->m_pkthdr.flowid = hash_val;
1492 			M_HASHTYPE_SET(m, hash_type);
1493 		}
1494 #endif
1495 	}
1496 
1497 #ifdef	RSS
1498 	/*
1499 	 * Don't override with the inp cached flowid value.
1500 	 *
1501 	 * Depending upon the kind of send being done, the inp
1502 	 * flowid/flowtype values may actually not be appropriate
1503 	 * for this particular socket send.
1504 	 *
1505 	 * We should either leave the flowid at zero (which is what is
1506 	 * currently done) or set it to some software generated
1507 	 * hash value based on the packet contents.
1508 	 */
1509 	ipflags |= IP_NODEFAULTFLOWID;
1510 #endif	/* RSS */
1511 
1512 	if (unlock_udbinfo == UH_WLOCKED)
1513 		INP_HASH_WUNLOCK(pcbinfo);
1514 	else if (unlock_udbinfo == UH_RLOCKED)
1515 		INP_HASH_RUNLOCK(pcbinfo);
1516 	UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1517 	error = ip_output(m, inp->inp_options, NULL, ipflags,
1518 	    inp->inp_moptions, inp);
1519 	if (unlock_udbinfo == UH_WLOCKED)
1520 		INP_WUNLOCK(inp);
1521 	else
1522 		INP_RUNLOCK(inp);
1523 	return (error);
1524 
1525 release:
1526 	if (unlock_udbinfo == UH_WLOCKED) {
1527 		INP_HASH_WUNLOCK(pcbinfo);
1528 		INP_WUNLOCK(inp);
1529 	} else if (unlock_udbinfo == UH_RLOCKED) {
1530 		INP_HASH_RUNLOCK(pcbinfo);
1531 		INP_RUNLOCK(inp);
1532 	} else
1533 		INP_RUNLOCK(inp);
1534 	m_freem(m);
1535 	return (error);
1536 }
1537 
1538 
1539 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1540 /*
1541  * Potentially decap ESP in UDP frame.  Check for an ESP header
1542  * and optional marker; if present, strip the UDP header and
1543  * push the result through IPSec.
1544  *
1545  * Returns mbuf to be processed (potentially re-allocated) or
1546  * NULL if consumed and/or processed.
1547  */
1548 static struct mbuf *
1549 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1550 {
1551 	size_t minlen, payload, skip, iphlen;
1552 	caddr_t data;
1553 	struct udpcb *up;
1554 	struct m_tag *tag;
1555 	struct udphdr *udphdr;
1556 	struct ip *ip;
1557 
1558 	INP_RLOCK_ASSERT(inp);
1559 
1560 	/*
1561 	 * Pull up data so the longest case is contiguous:
1562 	 *    IP/UDP hdr + non ESP marker + ESP hdr.
1563 	 */
1564 	minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1565 	if (minlen > m->m_pkthdr.len)
1566 		minlen = m->m_pkthdr.len;
1567 	if ((m = m_pullup(m, minlen)) == NULL) {
1568 		IPSECSTAT_INC(ips_in_inval);
1569 		return (NULL);		/* Bypass caller processing. */
1570 	}
1571 	data = mtod(m, caddr_t);	/* Points to ip header. */
1572 	payload = m->m_len - off;	/* Size of payload. */
1573 
1574 	if (payload == 1 && data[off] == '\xff')
1575 		return (m);		/* NB: keepalive packet, no decap. */
1576 
1577 	up = intoudpcb(inp);
1578 	KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1579 	KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1580 	    ("u_flags 0x%x", up->u_flags));
1581 
1582 	/*
1583 	 * Check that the payload is large enough to hold an
1584 	 * ESP header and compute the amount of data to remove.
1585 	 *
1586 	 * NB: the caller has already done a pullup for us.
1587 	 * XXX can we assume alignment and eliminate bcopys?
1588 	 */
1589 	if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1590 		/*
1591 		 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1592 		 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1593 		 * possible AH mode non-IKE marker+non-ESP marker
1594 		 * from draft-ietf-ipsec-udp-encaps-00.txt.
1595 		 */
1596 		uint64_t marker;
1597 
1598 		if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1599 			return (m);	/* NB: no decap. */
1600 		bcopy(data + off, &marker, sizeof(uint64_t));
1601 		if (marker != 0)	/* Non-IKE marker. */
1602 			return (m);	/* NB: no decap. */
1603 		skip = sizeof(uint64_t) + sizeof(struct udphdr);
1604 	} else {
1605 		uint32_t spi;
1606 
1607 		if (payload <= sizeof(struct esp)) {
1608 			IPSECSTAT_INC(ips_in_inval);
1609 			m_freem(m);
1610 			return (NULL);	/* Discard. */
1611 		}
1612 		bcopy(data + off, &spi, sizeof(uint32_t));
1613 		if (spi == 0)		/* Non-ESP marker. */
1614 			return (m);	/* NB: no decap. */
1615 		skip = sizeof(struct udphdr);
1616 	}
1617 
1618 	/*
1619 	 * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1620 	 * the UDP ports. This is required if we want to select
1621 	 * the right SPD for multiple hosts behind same NAT.
1622 	 *
1623 	 * NB: ports are maintained in network byte order everywhere
1624 	 *     in the NAT-T code.
1625 	 */
1626 	tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1627 		2 * sizeof(uint16_t), M_NOWAIT);
1628 	if (tag == NULL) {
1629 		IPSECSTAT_INC(ips_in_nomem);
1630 		m_freem(m);
1631 		return (NULL);		/* Discard. */
1632 	}
1633 	iphlen = off - sizeof(struct udphdr);
1634 	udphdr = (struct udphdr *)(data + iphlen);
1635 	((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1636 	((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1637 	m_tag_prepend(m, tag);
1638 
1639 	/*
1640 	 * Remove the UDP header (and possibly the non ESP marker)
1641 	 * IP header length is iphlen
1642 	 * Before:
1643 	 *   <--- off --->
1644 	 *   +----+------+-----+
1645 	 *   | IP |  UDP | ESP |
1646 	 *   +----+------+-----+
1647 	 *        <-skip->
1648 	 * After:
1649 	 *          +----+-----+
1650 	 *          | IP | ESP |
1651 	 *          +----+-----+
1652 	 *   <-skip->
1653 	 */
1654 	ovbcopy(data, data + skip, iphlen);
1655 	m_adj(m, skip);
1656 
1657 	ip = mtod(m, struct ip *);
1658 	ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1659 	ip->ip_p = IPPROTO_ESP;
1660 
1661 	/*
1662 	 * We cannot yet update the cksums so clear any
1663 	 * h/w cksum flags as they are no longer valid.
1664 	 */
1665 	if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1666 		m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1667 
1668 	(void) ipsec_common_input(m, iphlen, offsetof(struct ip, ip_p),
1669 				AF_INET, ip->ip_p);
1670 	return (NULL);			/* NB: consumed, bypass processing. */
1671 }
1672 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1673 
1674 static void
1675 udp_abort(struct socket *so)
1676 {
1677 	struct inpcb *inp;
1678 	struct inpcbinfo *pcbinfo;
1679 
1680 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1681 	inp = sotoinpcb(so);
1682 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1683 	INP_WLOCK(inp);
1684 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1685 		INP_HASH_WLOCK(pcbinfo);
1686 		in_pcbdisconnect(inp);
1687 		inp->inp_laddr.s_addr = INADDR_ANY;
1688 		INP_HASH_WUNLOCK(pcbinfo);
1689 		soisdisconnected(so);
1690 	}
1691 	INP_WUNLOCK(inp);
1692 }
1693 
1694 static int
1695 udp_attach(struct socket *so, int proto, struct thread *td)
1696 {
1697 	struct inpcb *inp;
1698 	struct inpcbinfo *pcbinfo;
1699 	int error;
1700 
1701 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1702 	inp = sotoinpcb(so);
1703 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1704 	error = soreserve(so, udp_sendspace, udp_recvspace);
1705 	if (error)
1706 		return (error);
1707 	INP_INFO_WLOCK(pcbinfo);
1708 	error = in_pcballoc(so, pcbinfo);
1709 	if (error) {
1710 		INP_INFO_WUNLOCK(pcbinfo);
1711 		return (error);
1712 	}
1713 
1714 	inp = sotoinpcb(so);
1715 	inp->inp_vflag |= INP_IPV4;
1716 	inp->inp_ip_ttl = V_ip_defttl;
1717 
1718 	error = udp_newudpcb(inp);
1719 	if (error) {
1720 		in_pcbdetach(inp);
1721 		in_pcbfree(inp);
1722 		INP_INFO_WUNLOCK(pcbinfo);
1723 		return (error);
1724 	}
1725 
1726 	INP_WUNLOCK(inp);
1727 	INP_INFO_WUNLOCK(pcbinfo);
1728 	return (0);
1729 }
1730 #endif /* INET */
1731 
1732 int
1733 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, void *ctx)
1734 {
1735 	struct inpcb *inp;
1736 	struct udpcb *up;
1737 
1738 	KASSERT(so->so_type == SOCK_DGRAM,
1739 	    ("udp_set_kernel_tunneling: !dgram"));
1740 	inp = sotoinpcb(so);
1741 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1742 	INP_WLOCK(inp);
1743 	up = intoudpcb(inp);
1744 	if (up->u_tun_func != NULL) {
1745 		INP_WUNLOCK(inp);
1746 		return (EBUSY);
1747 	}
1748 	up->u_tun_func = f;
1749 	up->u_tun_ctx = ctx;
1750 	INP_WUNLOCK(inp);
1751 	return (0);
1752 }
1753 
1754 #ifdef INET
1755 static int
1756 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1757 {
1758 	struct inpcb *inp;
1759 	struct inpcbinfo *pcbinfo;
1760 	int error;
1761 
1762 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1763 	inp = sotoinpcb(so);
1764 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1765 	INP_WLOCK(inp);
1766 	INP_HASH_WLOCK(pcbinfo);
1767 	error = in_pcbbind(inp, nam, td->td_ucred);
1768 	INP_HASH_WUNLOCK(pcbinfo);
1769 	INP_WUNLOCK(inp);
1770 	return (error);
1771 }
1772 
1773 static void
1774 udp_close(struct socket *so)
1775 {
1776 	struct inpcb *inp;
1777 	struct inpcbinfo *pcbinfo;
1778 
1779 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1780 	inp = sotoinpcb(so);
1781 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1782 	INP_WLOCK(inp);
1783 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1784 		INP_HASH_WLOCK(pcbinfo);
1785 		in_pcbdisconnect(inp);
1786 		inp->inp_laddr.s_addr = INADDR_ANY;
1787 		INP_HASH_WUNLOCK(pcbinfo);
1788 		soisdisconnected(so);
1789 	}
1790 	INP_WUNLOCK(inp);
1791 }
1792 
1793 static int
1794 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1795 {
1796 	struct inpcb *inp;
1797 	struct inpcbinfo *pcbinfo;
1798 	struct sockaddr_in *sin;
1799 	int error;
1800 
1801 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1802 	inp = sotoinpcb(so);
1803 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1804 	INP_WLOCK(inp);
1805 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1806 		INP_WUNLOCK(inp);
1807 		return (EISCONN);
1808 	}
1809 	sin = (struct sockaddr_in *)nam;
1810 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1811 	if (error != 0) {
1812 		INP_WUNLOCK(inp);
1813 		return (error);
1814 	}
1815 	INP_HASH_WLOCK(pcbinfo);
1816 	error = in_pcbconnect(inp, nam, td->td_ucred);
1817 	INP_HASH_WUNLOCK(pcbinfo);
1818 	if (error == 0)
1819 		soisconnected(so);
1820 	INP_WUNLOCK(inp);
1821 	return (error);
1822 }
1823 
1824 static void
1825 udp_detach(struct socket *so)
1826 {
1827 	struct inpcb *inp;
1828 	struct inpcbinfo *pcbinfo;
1829 	struct udpcb *up;
1830 
1831 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1832 	inp = sotoinpcb(so);
1833 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1834 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1835 	    ("udp_detach: not disconnected"));
1836 	INP_INFO_WLOCK(pcbinfo);
1837 	INP_WLOCK(inp);
1838 	up = intoudpcb(inp);
1839 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1840 	inp->inp_ppcb = NULL;
1841 	in_pcbdetach(inp);
1842 	in_pcbfree(inp);
1843 	INP_INFO_WUNLOCK(pcbinfo);
1844 	udp_discardcb(up);
1845 }
1846 
1847 static int
1848 udp_disconnect(struct socket *so)
1849 {
1850 	struct inpcb *inp;
1851 	struct inpcbinfo *pcbinfo;
1852 
1853 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1854 	inp = sotoinpcb(so);
1855 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1856 	INP_WLOCK(inp);
1857 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1858 		INP_WUNLOCK(inp);
1859 		return (ENOTCONN);
1860 	}
1861 	INP_HASH_WLOCK(pcbinfo);
1862 	in_pcbdisconnect(inp);
1863 	inp->inp_laddr.s_addr = INADDR_ANY;
1864 	INP_HASH_WUNLOCK(pcbinfo);
1865 	SOCK_LOCK(so);
1866 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1867 	SOCK_UNLOCK(so);
1868 	INP_WUNLOCK(inp);
1869 	return (0);
1870 }
1871 
1872 static int
1873 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1874     struct mbuf *control, struct thread *td)
1875 {
1876 	struct inpcb *inp;
1877 
1878 	inp = sotoinpcb(so);
1879 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1880 	return (udp_output(inp, m, addr, control, td));
1881 }
1882 #endif /* INET */
1883 
1884 int
1885 udp_shutdown(struct socket *so)
1886 {
1887 	struct inpcb *inp;
1888 
1889 	inp = sotoinpcb(so);
1890 	KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1891 	INP_WLOCK(inp);
1892 	socantsendmore(so);
1893 	INP_WUNLOCK(inp);
1894 	return (0);
1895 }
1896 
1897 #ifdef INET
1898 struct pr_usrreqs udp_usrreqs = {
1899 	.pru_abort =		udp_abort,
1900 	.pru_attach =		udp_attach,
1901 	.pru_bind =		udp_bind,
1902 	.pru_connect =		udp_connect,
1903 	.pru_control =		in_control,
1904 	.pru_detach =		udp_detach,
1905 	.pru_disconnect =	udp_disconnect,
1906 	.pru_peeraddr =		in_getpeeraddr,
1907 	.pru_send =		udp_send,
1908 	.pru_soreceive =	soreceive_dgram,
1909 	.pru_sosend =		sosend_dgram,
1910 	.pru_shutdown =		udp_shutdown,
1911 	.pru_sockaddr =		in_getsockaddr,
1912 	.pru_sosetlabel =	in_pcbsosetlabel,
1913 	.pru_close =		udp_close,
1914 };
1915 #endif /* INET */
1916