xref: /freebsd/sys/netinet/udp_usrreq.c (revision d3a3854fdc6e8da3bc6c1c13aab8d371445d2914)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
5  *	The Regents of the University of California.
6  * Copyright (c) 2008 Robert N. M. Watson
7  * Copyright (c) 2010-2011 Juniper Networks, Inc.
8  * Copyright (c) 2014 Kevin Lo
9  * All rights reserved.
10  *
11  * Portions of this software were developed by Robert N. M. Watson under
12  * contract to Juniper Networks, Inc.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #include "opt_inet.h"
41 #include "opt_inet6.h"
42 #include "opt_ipsec.h"
43 #include "opt_route.h"
44 #include "opt_rss.h"
45 
46 #include <sys/param.h>
47 #include <sys/domain.h>
48 #include <sys/eventhandler.h>
49 #include <sys/jail.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/priv.h>
55 #include <sys/proc.h>
56 #include <sys/protosw.h>
57 #include <sys/sdt.h>
58 #include <sys/signalvar.h>
59 #include <sys/socket.h>
60 #include <sys/socketvar.h>
61 #include <sys/sx.h>
62 #include <sys/sysctl.h>
63 #include <sys/syslog.h>
64 #include <sys/systm.h>
65 
66 #include <vm/uma.h>
67 
68 #include <net/if.h>
69 #include <net/if_var.h>
70 #include <net/route.h>
71 #include <net/route/nhop.h>
72 #include <net/rss_config.h>
73 
74 #include <netinet/in.h>
75 #include <netinet/in_kdtrace.h>
76 #include <netinet/in_fib.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 #include <netipsec/ipsec_support.h>
97 
98 #include <machine/in_cksum.h>
99 
100 #include <security/mac/mac_framework.h>
101 
102 /*
103  * UDP and UDP-Lite protocols implementation.
104  * Per RFC 768, August, 1980.
105  * Per RFC 3828, July, 2004.
106  */
107 
108 VNET_DEFINE(int, udp_bind_all_fibs) = 1;
109 SYSCTL_INT(_net_inet_udp, OID_AUTO, bind_all_fibs, CTLFLAG_VNET | CTLFLAG_RDTUN,
110     &VNET_NAME(udp_bind_all_fibs), 0,
111     "Bound sockets receive traffic from all FIBs");
112 
113 /*
114  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
115  * removes the only data integrity mechanism for packets and malformed
116  * packets that would otherwise be discarded due to bad checksums, and may
117  * cause problems (especially for NFS data blocks).
118  */
119 VNET_DEFINE(int, udp_cksum) = 1;
120 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
121     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
122 
123 VNET_DEFINE(int, udp_log_in_vain) = 0;
124 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_VNET | CTLFLAG_RW,
125     &VNET_NAME(udp_log_in_vain), 0, "Log all incoming UDP packets");
126 
127 VNET_DEFINE(int, udp_blackhole) = 0;
128 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
129     &VNET_NAME(udp_blackhole), 0,
130     "Do not send port unreachables for refused connects");
131 VNET_DEFINE(bool, udp_blackhole_local) = false;
132 SYSCTL_BOOL(_net_inet_udp, OID_AUTO, blackhole_local, CTLFLAG_VNET |
133     CTLFLAG_RW, &VNET_NAME(udp_blackhole_local), false,
134     "Enforce net.inet.udp.blackhole for locally originated packets");
135 
136 u_long	udp_sendspace = 9216;		/* really max datagram size */
137 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
138     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
139 
140 u_long	udp_recvspace = 40 * (1024 +
141 #ifdef INET6
142 				      sizeof(struct sockaddr_in6)
143 #else
144 				      sizeof(struct sockaddr_in)
145 #endif
146 				      );	/* 40 1K datagrams */
147 
148 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
149     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
150 
151 VNET_DEFINE(struct inpcbinfo, udbinfo);
152 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
153 
154 #ifndef UDBHASHSIZE
155 #define	UDBHASHSIZE	128
156 #endif
157 
158 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
159 VNET_PCPUSTAT_SYSINIT(udpstat);
160 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
161     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
162 
163 #ifdef VIMAGE
164 VNET_PCPUSTAT_SYSUNINIT(udpstat);
165 #endif /* VIMAGE */
166 #ifdef INET
167 static void	udp_detach(struct socket *so);
168 #endif
169 
170 INPCBSTORAGE_DEFINE(udpcbstor, udpcb, "udpinp", "udp_inpcb", "udp", "udphash");
171 INPCBSTORAGE_DEFINE(udplitecbstor, udpcb, "udpliteinp", "udplite_inpcb",
172     "udplite", "udplitehash");
173 
174 static void
udp_vnet_init(void * arg __unused)175 udp_vnet_init(void *arg __unused)
176 {
177 
178 	/*
179 	 * For now default to 2-tuple UDP hashing - until the fragment
180 	 * reassembly code can also update the flowid.
181 	 *
182 	 * Once we can calculate the flowid that way and re-establish
183 	 * a 4-tuple, flip this to 4-tuple.
184 	 */
185 	in_pcbinfo_init(&V_udbinfo, &udpcbstor, UDBHASHSIZE, UDBHASHSIZE);
186 	/* Additional pcbinfo for UDP-Lite */
187 	in_pcbinfo_init(&V_ulitecbinfo, &udplitecbstor, UDBHASHSIZE,
188 	    UDBHASHSIZE);
189 }
190 VNET_SYSINIT(udp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
191     udp_vnet_init, NULL);
192 
193 /*
194  * Kernel module interface for updating udpstat.  The argument is an index
195  * into udpstat treated as an array of u_long.  While this encodes the
196  * general layout of udpstat into the caller, it doesn't encode its location,
197  * so that future changes to add, for example, per-CPU stats support won't
198  * cause binary compatibility problems for kernel modules.
199  */
200 void
kmod_udpstat_inc(int statnum)201 kmod_udpstat_inc(int statnum)
202 {
203 
204 	counter_u64_add(VNET(udpstat)[statnum], 1);
205 }
206 
207 #ifdef VIMAGE
208 static void
udp_destroy(void * unused __unused)209 udp_destroy(void *unused __unused)
210 {
211 
212 	in_pcbinfo_destroy(&V_udbinfo);
213 	in_pcbinfo_destroy(&V_ulitecbinfo);
214 }
215 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
216 #endif
217 
218 #ifdef INET
219 /*
220  * Subroutine of udp_input(), which appends the provided mbuf chain to the
221  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
222  * contains the source address.  If the socket ends up being an IPv6 socket,
223  * udp_append() will convert to a sockaddr_in6 before passing the address
224  * into the socket code.
225  *
226  * In the normal case udp_append() will return 'false', indicating that you
227  * must unlock the inpcb.  However if a tunneling protocol is in place we
228  * increment the inpcb refcnt and unlock the inpcb, on return from the tunneling
229  * protocol we then decrement the reference count.  If in_pcbrele_rlocked()
230  * returns 'true', indicating the inpcb is gone, we return that to the caller
231  * to tell them *not* to unlock the inpcb.  In the case of multicast this will
232  * cause the distribution to stop (though most tunneling protocols known
233  * currently do *not* use multicast).
234  *
235  * The mbuf is always consumed.
236  */
237 static bool
udp_append(struct inpcb * inp,struct ip * ip,struct mbuf * n,int off,struct sockaddr_in * udp_in)238 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
239     struct sockaddr_in *udp_in)
240 {
241 	struct sockaddr *append_sa;
242 	struct socket *so;
243 	struct mbuf *tmpopts, *opts = NULL;
244 #ifdef INET6
245 	struct sockaddr_in6 udp_in6;
246 #endif
247 	struct udpcb *up;
248 
249 	INP_LOCK_ASSERT(inp);
250 
251 	/*
252 	 * Engage the tunneling protocol.
253 	 */
254 	up = intoudpcb(inp);
255 	if (up->u_tun_func != NULL) {
256 		bool filtered;
257 
258 		in_pcbref(inp);
259 		INP_RUNLOCK(inp);
260 		filtered = (*up->u_tun_func)(n, off, inp,
261 		    (struct sockaddr *)&udp_in[0], up->u_tun_ctx);
262 		INP_RLOCK(inp);
263 		if (in_pcbrele_rlocked(inp)) {
264 			if (!filtered)
265 				m_freem(n);
266 			return (true);
267 		}
268 		if (filtered)
269 			return (false);
270 	}
271 
272 	off += sizeof(struct udphdr);
273 
274 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
275 	/* Check AH/ESP integrity. */
276 	if (IPSEC_ENABLED(ipv4) &&
277 	    IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
278 		m_freem(n);
279 		return (false);
280 	}
281 	if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
282 		if (IPSEC_ENABLED(ipv4) &&
283 		    UDPENCAP_INPUT(ipv4, n, off, AF_INET) != 0)
284 			return (false);
285 	}
286 #endif /* IPSEC */
287 #ifdef MAC
288 	if (mac_inpcb_check_deliver(inp, n) != 0) {
289 		m_freem(n);
290 		return (false);
291 	}
292 #endif /* MAC */
293 	if (inp->inp_flags & INP_CONTROLOPTS ||
294 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
295 #ifdef INET6
296 		if (inp->inp_vflag & INP_IPV6)
297 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
298 		else
299 #endif /* INET6 */
300 			ip_savecontrol(inp, &opts, ip, n);
301 	}
302 	if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
303 		tmpopts = sbcreatecontrol(&udp_in[1],
304 		    sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP,
305 		    M_NOWAIT);
306 		if (tmpopts) {
307 			if (opts) {
308 				tmpopts->m_next = opts;
309 				opts = tmpopts;
310 			} else
311 				opts = tmpopts;
312 		}
313 	}
314 #ifdef INET6
315 	if (inp->inp_vflag & INP_IPV6) {
316 		bzero(&udp_in6, sizeof(udp_in6));
317 		udp_in6.sin6_len = sizeof(udp_in6);
318 		udp_in6.sin6_family = AF_INET6;
319 		in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
320 		append_sa = (struct sockaddr *)&udp_in6;
321 	} else
322 #endif /* INET6 */
323 		append_sa = (struct sockaddr *)&udp_in[0];
324 	m_adj(n, off);
325 
326 	so = inp->inp_socket;
327 	SOCKBUF_LOCK(&so->so_rcv);
328 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
329 		soroverflow_locked(so);
330 		m_freem(n);
331 		if (opts)
332 			m_freem(opts);
333 		UDPSTAT_INC(udps_fullsock);
334 	} else
335 		sorwakeup_locked(so);
336 	return (false);
337 }
338 
339 static bool
udp_multi_match(const struct inpcb * inp,void * v)340 udp_multi_match(const struct inpcb *inp, void *v)
341 {
342 	struct ip *ip = v;
343 	struct udphdr *uh = (struct udphdr *)(ip + 1);
344 
345 	if (inp->inp_lport != uh->uh_dport)
346 		return (false);
347 #ifdef INET6
348 	if ((inp->inp_vflag & INP_IPV4) == 0)
349 		return (false);
350 #endif
351 	if (inp->inp_laddr.s_addr != INADDR_ANY &&
352 	    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
353 		return (false);
354 	if (inp->inp_faddr.s_addr != INADDR_ANY &&
355 	    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
356 		return (false);
357 	if (inp->inp_fport != 0 &&
358 	    inp->inp_fport != uh->uh_sport)
359 		return (false);
360 
361 	return (true);
362 }
363 
364 static int
udp_multi_input(struct mbuf * m,int proto,struct sockaddr_in * udp_in)365 udp_multi_input(struct mbuf *m, int proto, struct sockaddr_in *udp_in)
366 {
367 	struct ip *ip = mtod(m, struct ip *);
368 	struct inpcb_iterator inpi = INP_ITERATOR(udp_get_inpcbinfo(proto),
369 	    INPLOOKUP_RLOCKPCB, udp_multi_match, ip);
370 #ifdef KDTRACE_HOOKS
371 	struct udphdr *uh = (struct udphdr *)(ip + 1);
372 #endif
373 	struct inpcb *inp;
374 	struct mbuf *n;
375 	int appends = 0, fib;
376 
377 	MPASS(ip->ip_hl == sizeof(struct ip) >> 2);
378 
379 	fib = M_GETFIB(m);
380 
381 	while ((inp = inp_next(&inpi)) != NULL) {
382 		/*
383 		 * XXXRW: Because we weren't holding either the inpcb
384 		 * or the hash lock when we checked for a match
385 		 * before, we should probably recheck now that the
386 		 * inpcb lock is held.
387 		 */
388 
389 		if (V_udp_bind_all_fibs == 0 && fib != inp->inp_inc.inc_fibnum)
390 			/*
391 			 * Sockets bound to a specific FIB can only receive
392 			 * packets from that FIB.
393 			 */
394 			continue;
395 
396 		/*
397 		 * Handle socket delivery policy for any-source
398 		 * and source-specific multicast. [RFC3678]
399 		 */
400 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
401 			struct ip_moptions	*imo;
402 			struct sockaddr_in	 group;
403 			int			 blocked;
404 
405 			imo = inp->inp_moptions;
406 			if (imo == NULL)
407 				continue;
408 			bzero(&group, sizeof(struct sockaddr_in));
409 			group.sin_len = sizeof(struct sockaddr_in);
410 			group.sin_family = AF_INET;
411 			group.sin_addr = ip->ip_dst;
412 
413 			blocked = imo_multi_filter(imo, m->m_pkthdr.rcvif,
414 				(struct sockaddr *)&group,
415 				(struct sockaddr *)&udp_in[0]);
416 			if (blocked != MCAST_PASS) {
417 				if (blocked == MCAST_NOTGMEMBER)
418 					IPSTAT_INC(ips_notmember);
419 				if (blocked == MCAST_NOTSMEMBER ||
420 				    blocked == MCAST_MUTED)
421 					UDPSTAT_INC(udps_filtermcast);
422 				continue;
423 			}
424 		}
425 		if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
426 			if (proto == IPPROTO_UDPLITE)
427 				UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
428 			else
429 				UDP_PROBE(receive, NULL, inp, ip, inp, uh);
430 			if (udp_append(inp, ip, n, sizeof(struct ip), udp_in)) {
431 				break;
432 			} else
433 				appends++;
434 		}
435 		/*
436 		 * Don't look for additional matches if this one does
437 		 * not have either the SO_REUSEPORT or SO_REUSEADDR
438 		 * socket options set.  This heuristic avoids
439 		 * searching through all pcbs in the common case of a
440 		 * non-shared port.  It assumes that an application
441 		 * will never clear these options after setting them.
442 		 */
443 		if ((inp->inp_socket->so_options &
444 		    (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0) {
445 			INP_RUNLOCK(inp);
446 			break;
447 		}
448 	}
449 
450 	if (appends == 0) {
451 		/*
452 		 * No matching pcb found; discard datagram.  (No need
453 		 * to send an ICMP Port Unreachable for a broadcast
454 		 * or multicast datagram.)
455 		 */
456 		UDPSTAT_INC(udps_noport);
457 		if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)))
458 			UDPSTAT_INC(udps_noportmcast);
459 		else
460 			UDPSTAT_INC(udps_noportbcast);
461 	}
462 	m_freem(m);
463 
464 	return (IPPROTO_DONE);
465 }
466 
467 static int
udp_input(struct mbuf ** mp,int * offp,int proto)468 udp_input(struct mbuf **mp, int *offp, int proto)
469 {
470 	struct ip *ip;
471 	struct udphdr *uh;
472 	struct ifnet *ifp;
473 	struct inpcb *inp;
474 	uint16_t len, ip_len;
475 	struct inpcbinfo *pcbinfo;
476 	struct sockaddr_in udp_in[2];
477 	struct mbuf *m;
478 	struct m_tag *fwd_tag;
479 	int cscov_partial, iphlen, lookupflags;
480 
481 	m = *mp;
482 	iphlen = *offp;
483 	ifp = m->m_pkthdr.rcvif;
484 	*mp = NULL;
485 	UDPSTAT_INC(udps_ipackets);
486 
487 	/*
488 	 * Strip IP options, if any; should skip this, make available to
489 	 * user, and use on returned packets, but we don't yet have a way to
490 	 * check the checksum with options still present.
491 	 */
492 	if (iphlen > sizeof (struct ip)) {
493 		ip_stripoptions(m);
494 		iphlen = sizeof(struct ip);
495 	}
496 
497 	/*
498 	 * Get IP and UDP header together in first mbuf.
499 	 */
500 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
501 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
502 			UDPSTAT_INC(udps_hdrops);
503 			return (IPPROTO_DONE);
504 		}
505 	}
506 	ip = mtod(m, struct ip *);
507 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
508 	cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
509 
510 	/*
511 	 * Destination port of 0 is illegal, based on RFC768.
512 	 */
513 	if (uh->uh_dport == 0)
514 		goto badunlocked;
515 
516 	/*
517 	 * Construct sockaddr format source address.  Stuff source address
518 	 * and datagram in user buffer.
519 	 */
520 	bzero(&udp_in[0], sizeof(struct sockaddr_in) * 2);
521 	udp_in[0].sin_len = sizeof(struct sockaddr_in);
522 	udp_in[0].sin_family = AF_INET;
523 	udp_in[0].sin_port = uh->uh_sport;
524 	udp_in[0].sin_addr = ip->ip_src;
525 	udp_in[1].sin_len = sizeof(struct sockaddr_in);
526 	udp_in[1].sin_family = AF_INET;
527 	udp_in[1].sin_port = uh->uh_dport;
528 	udp_in[1].sin_addr = ip->ip_dst;
529 
530 	/*
531 	 * Make mbuf data length reflect UDP length.  If not enough data to
532 	 * reflect UDP length, drop.
533 	 */
534 	len = ntohs((u_short)uh->uh_ulen);
535 	ip_len = ntohs(ip->ip_len) - iphlen;
536 	if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
537 		/* Zero means checksum over the complete packet. */
538 		if (len == 0)
539 			len = ip_len;
540 		cscov_partial = 0;
541 	}
542 	if (ip_len != len) {
543 		if (len > ip_len || len < sizeof(struct udphdr)) {
544 			UDPSTAT_INC(udps_badlen);
545 			goto badunlocked;
546 		}
547 		if (proto == IPPROTO_UDP)
548 			m_adj(m, len - ip_len);
549 	}
550 
551 	/*
552 	 * Checksum extended UDP header and data.
553 	 */
554 	if (uh->uh_sum) {
555 		u_short uh_sum;
556 
557 		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
558 		    !cscov_partial) {
559 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
560 				uh_sum = m->m_pkthdr.csum_data;
561 			else
562 				uh_sum = in_pseudo(ip->ip_src.s_addr,
563 				    ip->ip_dst.s_addr, htonl((u_short)len +
564 				    m->m_pkthdr.csum_data + proto));
565 			uh_sum ^= 0xffff;
566 		} else if (m->m_pkthdr.csum_flags & CSUM_IP_UDP) {
567 			/*
568 			 * Packet from local host (maybe from a VM).
569 			 * Checksum not required.
570 			 */
571 			uh_sum = 0;
572 		} else {
573 			char b[offsetof(struct ipovly, ih_src)];
574 			struct ipovly *ipov = (struct ipovly *)ip;
575 
576 			memcpy(b, ipov, sizeof(b));
577 			bzero(ipov, sizeof(ipov->ih_x1));
578 			ipov->ih_len = (proto == IPPROTO_UDP) ?
579 			    uh->uh_ulen : htons(ip_len);
580 			uh_sum = in_cksum(m, len + sizeof (struct ip));
581 			memcpy(ipov, b, sizeof(b));
582 		}
583 		if (uh_sum) {
584 			UDPSTAT_INC(udps_badsum);
585 			m_freem(m);
586 			return (IPPROTO_DONE);
587 		}
588 	} else {
589 		if (proto == IPPROTO_UDP) {
590 			UDPSTAT_INC(udps_nosum);
591 		} else {
592 			/* UDPLite requires a checksum */
593 			/* XXX: What is the right UDPLite MIB counter here? */
594 			m_freem(m);
595 			return (IPPROTO_DONE);
596 		}
597 	}
598 
599 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
600 	    in_ifnet_broadcast(ip->ip_dst, ifp))
601 		return (udp_multi_input(m, proto, udp_in));
602 
603 	pcbinfo = udp_get_inpcbinfo(proto);
604 
605 	/*
606 	 * Locate pcb for datagram.
607 	 */
608 	lookupflags = INPLOOKUP_RLOCKPCB |
609 	    (V_udp_bind_all_fibs ? 0 : INPLOOKUP_FIB);
610 
611 	/*
612 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
613 	 */
614 	if ((m->m_flags & M_IP_NEXTHOP) &&
615 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
616 		struct sockaddr_in *next_hop;
617 
618 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
619 
620 		/*
621 		 * Transparently forwarded. Pretend to be the destination.
622 		 * Already got one like this?
623 		 */
624 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
625 		    ip->ip_dst, uh->uh_dport, lookupflags, ifp, m);
626 		if (!inp) {
627 			/*
628 			 * It's new.  Try to find the ambushing socket.
629 			 * Because we've rewritten the destination address,
630 			 * any hardware-generated hash is ignored.
631 			 */
632 			inp = in_pcblookup(pcbinfo, ip->ip_src,
633 			    uh->uh_sport, next_hop->sin_addr,
634 			    next_hop->sin_port ? htons(next_hop->sin_port) :
635 			    uh->uh_dport, INPLOOKUP_WILDCARD | lookupflags,
636 			    ifp);
637 		}
638 		/* Remove the tag from the packet. We don't need it anymore. */
639 		m_tag_delete(m, fwd_tag);
640 		m->m_flags &= ~M_IP_NEXTHOP;
641 	} else
642 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
643 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
644 		    lookupflags, ifp, m);
645 	if (inp == NULL) {
646 		if (V_udp_log_in_vain) {
647 			char src[INET_ADDRSTRLEN];
648 			char dst[INET_ADDRSTRLEN];
649 
650 			log(LOG_INFO,
651 			    "Connection attempt to UDP %s:%d from %s:%d\n",
652 			    inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
653 			    inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
654 		}
655 		if (proto == IPPROTO_UDPLITE)
656 			UDPLITE_PROBE(receive, NULL, NULL, ip, NULL, uh);
657 		else
658 			UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
659 		UDPSTAT_INC(udps_noport);
660 		if (m->m_flags & M_MCAST) {
661 			UDPSTAT_INC(udps_noportmcast);
662 			goto badunlocked;
663 		}
664 		if (m->m_flags & M_BCAST) {
665 			UDPSTAT_INC(udps_noportbcast);
666 			goto badunlocked;
667 		}
668 		if (V_udp_blackhole && (V_udp_blackhole_local ||
669 		    !in_localip(ip->ip_src)))
670 			goto badunlocked;
671 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
672 			goto badunlocked;
673 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
674 		return (IPPROTO_DONE);
675 	}
676 
677 	/*
678 	 * Check the minimum TTL for socket.
679 	 */
680 	INP_RLOCK_ASSERT(inp);
681 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
682 		if (proto == IPPROTO_UDPLITE)
683 			UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
684 		else
685 			UDP_PROBE(receive, NULL, inp, ip, inp, uh);
686 		INP_RUNLOCK(inp);
687 		m_freem(m);
688 		return (IPPROTO_DONE);
689 	}
690 	if (cscov_partial) {
691 		struct udpcb *up;
692 
693 		up = intoudpcb(inp);
694 		if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
695 			INP_RUNLOCK(inp);
696 			m_freem(m);
697 			return (IPPROTO_DONE);
698 		}
699 	}
700 
701 	if (proto == IPPROTO_UDPLITE)
702 		UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
703 	else
704 		UDP_PROBE(receive, NULL, inp, ip, inp, uh);
705 	if (!udp_append(inp, ip, m, iphlen, udp_in))
706 		INP_RUNLOCK(inp);
707 	return (IPPROTO_DONE);
708 
709 badunlocked:
710 	m_freem(m);
711 	return (IPPROTO_DONE);
712 }
713 #endif /* INET */
714 
715 /*
716  * Notify a udp user of an asynchronous error; just wake up so that they can
717  * collect error status.
718  */
719 struct inpcb *
udp_notify(struct inpcb * inp,int errno)720 udp_notify(struct inpcb *inp, int errno)
721 {
722 
723 	INP_WLOCK_ASSERT(inp);
724 	if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
725 	     errno == EHOSTDOWN) && inp->inp_route.ro_nh) {
726 		NH_FREE(inp->inp_route.ro_nh);
727 		inp->inp_route.ro_nh = (struct nhop_object *)NULL;
728 	}
729 
730 	inp->inp_socket->so_error = errno;
731 	sorwakeup(inp->inp_socket);
732 	sowwakeup(inp->inp_socket);
733 	return (inp);
734 }
735 
736 #ifdef INET
737 static void
udp_common_ctlinput(struct icmp * icmp,struct inpcbinfo * pcbinfo)738 udp_common_ctlinput(struct icmp *icmp, struct inpcbinfo *pcbinfo)
739 {
740 	struct ip *ip = &icmp->icmp_ip;
741 	struct udphdr *uh;
742 	struct inpcb *inp;
743 
744 	if (icmp_errmap(icmp) == 0)
745 		return;
746 
747 	uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
748 	inp = in_pcblookup(pcbinfo, ip->ip_dst, uh->uh_dport, ip->ip_src,
749 	    uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
750 	if (inp != NULL) {
751 		INP_WLOCK_ASSERT(inp);
752 		if (inp->inp_socket != NULL)
753 			udp_notify(inp, icmp_errmap(icmp));
754 		INP_WUNLOCK(inp);
755 	} else {
756 		inp = in_pcblookup(pcbinfo, ip->ip_dst, uh->uh_dport,
757 		    ip->ip_src, uh->uh_sport,
758 		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
759 		if (inp != NULL) {
760 			struct udpcb *up;
761 			udp_tun_icmp_t *func;
762 
763 			up = intoudpcb(inp);
764 			func = up->u_icmp_func;
765 			INP_RUNLOCK(inp);
766 			if (func != NULL)
767 				func(icmp);
768 		}
769 	}
770 }
771 
772 static void
udp_ctlinput(struct icmp * icmp)773 udp_ctlinput(struct icmp *icmp)
774 {
775 
776 	return (udp_common_ctlinput(icmp, &V_udbinfo));
777 }
778 
779 static void
udplite_ctlinput(struct icmp * icmp)780 udplite_ctlinput(struct icmp *icmp)
781 {
782 
783 	return (udp_common_ctlinput(icmp, &V_ulitecbinfo));
784 }
785 #endif /* INET */
786 
787 static int
udp_pcblist(SYSCTL_HANDLER_ARGS)788 udp_pcblist(SYSCTL_HANDLER_ARGS)
789 {
790 	struct inpcbinfo *pcbinfo = udp_get_inpcbinfo(arg2);
791 	struct inpcb_iterator inpi = INP_ALL_ITERATOR(pcbinfo,
792 	    INPLOOKUP_RLOCKPCB);
793 	struct xinpgen xig;
794 	struct inpcb *inp;
795 	int error;
796 
797 	if (req->newptr != 0)
798 		return (EPERM);
799 
800 	if (req->oldptr == 0) {
801 		int n;
802 
803 		n = pcbinfo->ipi_count;
804 		n += imax(n / 8, 10);
805 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
806 		return (0);
807 	}
808 
809 	if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
810 		return (error);
811 
812 	bzero(&xig, sizeof(xig));
813 	xig.xig_len = sizeof xig;
814 	xig.xig_count = pcbinfo->ipi_count;
815 	xig.xig_gen = pcbinfo->ipi_gencnt;
816 	xig.xig_sogen = so_gencnt;
817 	error = SYSCTL_OUT(req, &xig, sizeof xig);
818 	if (error)
819 		return (error);
820 
821 	while ((inp = inp_next(&inpi)) != NULL) {
822 		if (inp->inp_gencnt <= xig.xig_gen &&
823 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
824 			struct xinpcb xi;
825 
826 			in_pcbtoxinpcb(inp, &xi);
827 			error = SYSCTL_OUT(req, &xi, sizeof xi);
828 			if (error) {
829 				INP_RUNLOCK(inp);
830 				break;
831 			}
832 		}
833 	}
834 
835 	if (!error) {
836 		/*
837 		 * Give the user an updated idea of our state.  If the
838 		 * generation differs from what we told her before, she knows
839 		 * that something happened while we were processing this
840 		 * request, and it might be necessary to retry.
841 		 */
842 		xig.xig_gen = pcbinfo->ipi_gencnt;
843 		xig.xig_sogen = so_gencnt;
844 		xig.xig_count = pcbinfo->ipi_count;
845 		error = SYSCTL_OUT(req, &xig, sizeof xig);
846 	}
847 
848 	return (error);
849 }
850 
851 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
852     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, IPPROTO_UDP,
853     udp_pcblist, "S,xinpcb",
854     "List of active UDP sockets");
855 
856 SYSCTL_PROC(_net_inet_udplite, OID_AUTO, pcblist,
857     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, IPPROTO_UDPLITE,
858     udp_pcblist, "S,xinpcb",
859     "List of active UDP-Lite sockets");
860 
861 #ifdef INET
862 static int
udp_getcred(SYSCTL_HANDLER_ARGS)863 udp_getcred(SYSCTL_HANDLER_ARGS)
864 {
865 	struct xucred xuc;
866 	struct sockaddr_in addrs[2];
867 	struct epoch_tracker et;
868 	struct inpcb *inp;
869 	int error;
870 
871 	if (req->newptr == NULL)
872 		return (EINVAL);
873 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
874 	if (error)
875 		return (error);
876 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
877 	if (error)
878 		return (error);
879 	NET_EPOCH_ENTER(et);
880 	inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
881 	    addrs[0].sin_addr, addrs[0].sin_port,
882 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
883 	NET_EPOCH_EXIT(et);
884 	if (inp != NULL) {
885 		INP_RLOCK_ASSERT(inp);
886 		if (inp->inp_socket == NULL)
887 			error = ENOENT;
888 		if (error == 0)
889 			error = cr_canseeinpcb(req->td->td_ucred, inp);
890 		if (error == 0)
891 			cru2x(inp->inp_cred, &xuc);
892 		INP_RUNLOCK(inp);
893 	} else
894 		error = ENOENT;
895 	if (error == 0)
896 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
897 	return (error);
898 }
899 
900 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
901     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
902     0, 0, udp_getcred, "S,xucred",
903     "Get the xucred of a UDP connection");
904 #endif /* INET */
905 
906 int
udp_ctloutput(struct socket * so,struct sockopt * sopt)907 udp_ctloutput(struct socket *so, struct sockopt *sopt)
908 {
909 	struct inpcb *inp;
910 	struct udpcb *up;
911 	int isudplite, error, optval;
912 
913 	error = 0;
914 	isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
915 	inp = sotoinpcb(so);
916 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
917 	INP_WLOCK(inp);
918 	if (sopt->sopt_level != so->so_proto->pr_protocol) {
919 #ifdef INET6
920 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
921 			INP_WUNLOCK(inp);
922 			error = ip6_ctloutput(so, sopt);
923 		}
924 #endif
925 #if defined(INET) && defined(INET6)
926 		else
927 #endif
928 #ifdef INET
929 		{
930 			INP_WUNLOCK(inp);
931 			error = ip_ctloutput(so, sopt);
932 		}
933 #endif
934 		return (error);
935 	}
936 
937 	switch (sopt->sopt_dir) {
938 	case SOPT_SET:
939 		switch (sopt->sopt_name) {
940 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
941 #if defined(INET) || defined(INET6)
942 		case UDP_ENCAP:
943 #ifdef INET
944 			if (INP_SOCKAF(so) == AF_INET) {
945 				if (!IPSEC_ENABLED(ipv4)) {
946 					INP_WUNLOCK(inp);
947 					return (ENOPROTOOPT);
948 				}
949 				error = UDPENCAP_PCBCTL(ipv4, inp, sopt);
950 				break;
951 			}
952 #endif /* INET */
953 #ifdef INET6
954 			if (INP_SOCKAF(so) == AF_INET6) {
955 				if (!IPSEC_ENABLED(ipv6)) {
956 					INP_WUNLOCK(inp);
957 					return (ENOPROTOOPT);
958 				}
959 				error = UDPENCAP_PCBCTL(ipv6, inp, sopt);
960 				break;
961 			}
962 #endif /* INET6 */
963 			INP_WUNLOCK(inp);
964 			return (EINVAL);
965 #endif /* INET || INET6 */
966 
967 #endif /* IPSEC */
968 		case UDPLITE_SEND_CSCOV:
969 		case UDPLITE_RECV_CSCOV:
970 			if (!isudplite) {
971 				INP_WUNLOCK(inp);
972 				error = ENOPROTOOPT;
973 				break;
974 			}
975 			INP_WUNLOCK(inp);
976 			error = sooptcopyin(sopt, &optval, sizeof(optval),
977 			    sizeof(optval));
978 			if (error != 0)
979 				break;
980 			inp = sotoinpcb(so);
981 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
982 			INP_WLOCK(inp);
983 			up = intoudpcb(inp);
984 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
985 			if ((optval != 0 && optval < 8) || (optval > 65535)) {
986 				INP_WUNLOCK(inp);
987 				error = EINVAL;
988 				break;
989 			}
990 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
991 				up->u_txcslen = optval;
992 			else
993 				up->u_rxcslen = optval;
994 			INP_WUNLOCK(inp);
995 			break;
996 		default:
997 			INP_WUNLOCK(inp);
998 			error = ENOPROTOOPT;
999 			break;
1000 		}
1001 		break;
1002 	case SOPT_GET:
1003 		switch (sopt->sopt_name) {
1004 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1005 #if defined(INET) || defined(INET6)
1006 		case UDP_ENCAP:
1007 #ifdef INET
1008 			if (INP_SOCKAF(so) == AF_INET) {
1009 				if (!IPSEC_ENABLED(ipv4)) {
1010 					INP_WUNLOCK(inp);
1011 					return (ENOPROTOOPT);
1012 				}
1013 				error = UDPENCAP_PCBCTL(ipv4, inp, sopt);
1014 				break;
1015 			}
1016 #endif /* INET */
1017 #ifdef INET6
1018 			if (INP_SOCKAF(so) == AF_INET6) {
1019 				if (!IPSEC_ENABLED(ipv6)) {
1020 					INP_WUNLOCK(inp);
1021 					return (ENOPROTOOPT);
1022 				}
1023 				error = UDPENCAP_PCBCTL(ipv6, inp, sopt);
1024 				break;
1025 			}
1026 #endif /* INET6 */
1027 			INP_WUNLOCK(inp);
1028 			return (EINVAL);
1029 #endif /* INET || INET6 */
1030 
1031 #endif /* IPSEC */
1032 		case UDPLITE_SEND_CSCOV:
1033 		case UDPLITE_RECV_CSCOV:
1034 			if (!isudplite) {
1035 				INP_WUNLOCK(inp);
1036 				error = ENOPROTOOPT;
1037 				break;
1038 			}
1039 			up = intoudpcb(inp);
1040 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1041 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1042 				optval = up->u_txcslen;
1043 			else
1044 				optval = up->u_rxcslen;
1045 			INP_WUNLOCK(inp);
1046 			error = sooptcopyout(sopt, &optval, sizeof(optval));
1047 			break;
1048 		default:
1049 			INP_WUNLOCK(inp);
1050 			error = ENOPROTOOPT;
1051 			break;
1052 		}
1053 		break;
1054 	}
1055 	return (error);
1056 }
1057 
1058 #ifdef INET
1059 #ifdef INET6
1060 /* The logic here is derived from ip6_setpktopt(). See comments there. */
1061 static int
udp_v4mapped_pktinfo(struct cmsghdr * cm,struct sockaddr_in * src,struct inpcb * inp,int flags)1062 udp_v4mapped_pktinfo(struct cmsghdr *cm, struct sockaddr_in * src,
1063     struct inpcb *inp, int flags)
1064 {
1065 	struct ifnet *ifp;
1066 	struct in6_pktinfo *pktinfo;
1067 	struct in_addr ia;
1068 
1069 	NET_EPOCH_ASSERT();
1070 
1071 	if ((flags & PRUS_IPV6) == 0)
1072 		return (0);
1073 
1074 	if (cm->cmsg_level != IPPROTO_IPV6)
1075 		return (0);
1076 
1077 	if  (cm->cmsg_type != IPV6_2292PKTINFO &&
1078 	    cm->cmsg_type != IPV6_PKTINFO)
1079 		return (0);
1080 
1081 	if (cm->cmsg_len !=
1082 	    CMSG_LEN(sizeof(struct in6_pktinfo)))
1083 		return (EINVAL);
1084 
1085 	pktinfo = (struct in6_pktinfo *)CMSG_DATA(cm);
1086 	if (!IN6_IS_ADDR_V4MAPPED(&pktinfo->ipi6_addr) &&
1087 	    !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr))
1088 		return (EINVAL);
1089 
1090 	/* Validate the interface index if specified. */
1091 	if (pktinfo->ipi6_ifindex) {
1092 		ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
1093 		if (ifp == NULL)
1094 			return (ENXIO);
1095 	} else
1096 		ifp = NULL;
1097 	if (ifp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
1098 		ia.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1099 		if (!in_ifhasaddr(ifp, ia))
1100 			return (EADDRNOTAVAIL);
1101 	}
1102 
1103 	bzero(src, sizeof(*src));
1104 	src->sin_family = AF_INET;
1105 	src->sin_len = sizeof(*src);
1106 	src->sin_port = inp->inp_lport;
1107 	src->sin_addr.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1108 
1109 	return (0);
1110 }
1111 #endif	/* INET6 */
1112 
1113 int
udp_send(struct socket * so,int flags,struct mbuf * m,struct sockaddr * addr,struct mbuf * control,struct thread * td)1114 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1115     struct mbuf *control, struct thread *td)
1116 {
1117 	struct inpcb *inp;
1118 	struct udpiphdr *ui;
1119 	int len, error = 0;
1120 	struct in_addr faddr, laddr;
1121 	struct cmsghdr *cm;
1122 	struct inpcbinfo *pcbinfo;
1123 	struct sockaddr_in *sin, src;
1124 	struct epoch_tracker et;
1125 	int cscov_partial = 0;
1126 	int ipflags = 0;
1127 	u_short fport, lport;
1128 	u_char tos, vflagsav;
1129 	uint8_t pr;
1130 	uint16_t cscov = 0;
1131 	uint32_t flowid = 0;
1132 	uint8_t flowtype = M_HASHTYPE_NONE;
1133 	bool use_cached_route;
1134 
1135 	inp = sotoinpcb(so);
1136 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1137 
1138 	if (addr != NULL) {
1139 		if (addr->sa_family != AF_INET)
1140 			error = EAFNOSUPPORT;
1141 		else if (addr->sa_len != sizeof(struct sockaddr_in))
1142 			error = EINVAL;
1143 		if (__predict_false(error != 0)) {
1144 			m_freem(control);
1145 			m_freem(m);
1146 			return (error);
1147 		}
1148 	}
1149 
1150 	len = m->m_pkthdr.len;
1151 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1152 		if (control)
1153 			m_freem(control);
1154 		m_freem(m);
1155 		return (EMSGSIZE);
1156 	}
1157 
1158 	src.sin_family = 0;
1159 	sin = (struct sockaddr_in *)addr;
1160 
1161 	/*
1162 	 * udp_send() may need to bind the current inpcb.  As such, we don't
1163 	 * know up front whether we will need the pcbinfo lock or not.  Do any
1164 	 * work to decide what is needed up front before acquiring any locks.
1165 	 *
1166 	 * We will need network epoch in either case, to safely lookup into
1167 	 * pcb hash.
1168 	 */
1169 	use_cached_route = sin == NULL || (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0);
1170 	if (use_cached_route || (flags & PRUS_IPV6) != 0)
1171 		INP_WLOCK(inp);
1172 	else
1173 		INP_RLOCK(inp);
1174 	NET_EPOCH_ENTER(et);
1175 #ifdef INET6
1176 	if ((flags & PRUS_IPV6) != 0) {
1177 		if ((inp->in6p_outputopts != NULL) &&
1178 		    (inp->in6p_outputopts->ip6po_tclass != -1))
1179 			tos = (u_char)inp->in6p_outputopts->ip6po_tclass;
1180 		else
1181 			tos = 0;
1182 	} else {
1183 		tos = inp->inp_ip_tos;
1184 	}
1185 #else
1186 	tos = inp->inp_ip_tos;
1187 #endif
1188 	if (control != NULL) {
1189 		/*
1190 		 * XXX: Currently, we assume all the optional information is
1191 		 * stored in a single mbuf.
1192 		 */
1193 		if (control->m_next) {
1194 			m_freem(control);
1195 			error = EINVAL;
1196 			goto release;
1197 		}
1198 		for (; control->m_len > 0;
1199 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
1200 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1201 			cm = mtod(control, struct cmsghdr *);
1202 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1203 			    || cm->cmsg_len > control->m_len) {
1204 				error = EINVAL;
1205 				break;
1206 			}
1207 #ifdef INET6
1208 			error = udp_v4mapped_pktinfo(cm, &src, inp, flags);
1209 			if (error != 0)
1210 				break;
1211 			if (((flags & PRUS_IPV6) != 0) &&
1212 			    (cm->cmsg_level == IPPROTO_IPV6) &&
1213 			    (cm->cmsg_type == IPV6_TCLASS)) {
1214 				int tclass;
1215 
1216 				if (cm->cmsg_len != CMSG_LEN(sizeof(int))) {
1217 					error = EINVAL;
1218 					break;
1219 				}
1220 				tclass = *(int *)CMSG_DATA(cm);
1221 				if (tclass < -1 || tclass > 255) {
1222 					error = EINVAL;
1223 					break;
1224 				}
1225 				if (tclass != -1)
1226 					tos = (u_char)tclass;
1227 			}
1228 #endif
1229 			if (cm->cmsg_level != IPPROTO_IP)
1230 				continue;
1231 
1232 			switch (cm->cmsg_type) {
1233 			case IP_SENDSRCADDR:
1234 				if (cm->cmsg_len !=
1235 				    CMSG_LEN(sizeof(struct in_addr))) {
1236 					error = EINVAL;
1237 					break;
1238 				}
1239 				bzero(&src, sizeof(src));
1240 				src.sin_family = AF_INET;
1241 				src.sin_len = sizeof(src);
1242 				src.sin_port = inp->inp_lport;
1243 				src.sin_addr =
1244 				    *(struct in_addr *)CMSG_DATA(cm);
1245 				break;
1246 
1247 			case IP_TOS:
1248 				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1249 					error = EINVAL;
1250 					break;
1251 				}
1252 				tos = *(u_char *)CMSG_DATA(cm);
1253 				break;
1254 
1255 			case IP_FLOWID:
1256 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1257 					error = EINVAL;
1258 					break;
1259 				}
1260 				flowid = *(uint32_t *) CMSG_DATA(cm);
1261 				break;
1262 
1263 			case IP_FLOWTYPE:
1264 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1265 					error = EINVAL;
1266 					break;
1267 				}
1268 				flowtype = *(uint32_t *) CMSG_DATA(cm);
1269 				break;
1270 
1271 #ifdef	RSS
1272 			case IP_RSSBUCKETID:
1273 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1274 					error = EINVAL;
1275 					break;
1276 				}
1277 				/* This is just a placeholder for now */
1278 				break;
1279 #endif	/* RSS */
1280 			default:
1281 				error = ENOPROTOOPT;
1282 				break;
1283 			}
1284 			if (error)
1285 				break;
1286 		}
1287 		m_freem(control);
1288 		control = NULL;
1289 	}
1290 	if (error)
1291 		goto release;
1292 
1293 	pr = inp->inp_socket->so_proto->pr_protocol;
1294 	pcbinfo = udp_get_inpcbinfo(pr);
1295 
1296 	/*
1297 	 * If the IP_SENDSRCADDR control message was specified, override the
1298 	 * source address for this datagram.  Its use is invalidated if the
1299 	 * address thus specified is incomplete or clobbers other inpcbs.
1300 	 */
1301 	laddr = inp->inp_laddr;
1302 	lport = inp->inp_lport;
1303 	if (src.sin_family == AF_INET) {
1304 		if ((lport == 0) ||
1305 		    (laddr.s_addr == INADDR_ANY &&
1306 		     src.sin_addr.s_addr == INADDR_ANY)) {
1307 			error = EINVAL;
1308 			goto release;
1309 		}
1310 		if ((flags & PRUS_IPV6) != 0) {
1311 			vflagsav = inp->inp_vflag;
1312 			inp->inp_vflag |= INP_IPV4;
1313 			inp->inp_vflag &= ~INP_IPV6;
1314 		}
1315 		INP_HASH_WLOCK(pcbinfo);
1316 		error = in_pcbbind_setup(inp, &src, &laddr.s_addr, &lport,
1317 		    V_udp_bind_all_fibs ? 0 : INPBIND_FIB, td->td_ucred);
1318 		INP_HASH_WUNLOCK(pcbinfo);
1319 		if ((flags & PRUS_IPV6) != 0)
1320 			inp->inp_vflag = vflagsav;
1321 		if (error)
1322 			goto release;
1323 	}
1324 
1325 	/*
1326 	 * If a UDP socket has been connected, then a local address/port will
1327 	 * have been selected and bound.
1328 	 *
1329 	 * If a UDP socket has not been connected to, then an explicit
1330 	 * destination address must be used, in which case a local
1331 	 * address/port may not have been selected and bound.
1332 	 */
1333 	if (sin != NULL) {
1334 		INP_LOCK_ASSERT(inp);
1335 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1336 			error = EISCONN;
1337 			goto release;
1338 		}
1339 
1340 		/*
1341 		 * Jail may rewrite the destination address, so let it do
1342 		 * that before we use it.
1343 		 */
1344 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1345 		if (error)
1346 			goto release;
1347 		/*
1348 		 * sendto(2) on unconnected UDP socket results in implicit
1349 		 * binding to INADDR_ANY and anonymous port.  This has two
1350 		 * side effects:
1351 		 * 1) after first sendto(2) the socket will receive datagrams
1352 		 *    destined to the selected port.
1353 		 * 2) subsequent sendto(2) calls will use the same source port.
1354 		 */
1355 		if (inp->inp_lport == 0) {
1356 			struct sockaddr_in wild = {
1357 				.sin_family = AF_INET,
1358 				.sin_len = sizeof(struct sockaddr_in),
1359 			};
1360 
1361 			INP_HASH_WLOCK(pcbinfo);
1362 			error = in_pcbbind(inp, &wild, V_udp_bind_all_fibs ?
1363 			    0 : INPBIND_FIB, td->td_ucred);
1364 			INP_HASH_WUNLOCK(pcbinfo);
1365 			if (error)
1366 				goto release;
1367 			lport = inp->inp_lport;
1368 			laddr = inp->inp_laddr;
1369 		}
1370 		if (laddr.s_addr == INADDR_ANY) {
1371 			error = in_pcbladdr(inp, &sin->sin_addr, &laddr,
1372 			    td->td_ucred);
1373 			if (error)
1374 				goto release;
1375 		}
1376 		faddr = sin->sin_addr;
1377 		fport = sin->sin_port;
1378 	} else {
1379 		INP_LOCK_ASSERT(inp);
1380 		faddr = inp->inp_faddr;
1381 		fport = inp->inp_fport;
1382 		if (faddr.s_addr == INADDR_ANY) {
1383 			error = ENOTCONN;
1384 			goto release;
1385 		}
1386 	}
1387 
1388 	/*
1389 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1390 	 * link-layer headers.  Immediate slide the data pointer back forward
1391 	 * since we won't use that space at this layer.
1392 	 */
1393 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1394 	if (m == NULL) {
1395 		error = ENOBUFS;
1396 		goto release;
1397 	}
1398 	m->m_data += max_linkhdr;
1399 	m->m_len -= max_linkhdr;
1400 	m->m_pkthdr.len -= max_linkhdr;
1401 
1402 	/*
1403 	 * Fill in mbuf with extended UDP header and addresses and length put
1404 	 * into network format.
1405 	 */
1406 	ui = mtod(m, struct udpiphdr *);
1407 	/*
1408 	 * Filling only those fields of udpiphdr that participate in the
1409 	 * checksum calculation. The rest must be zeroed and will be filled
1410 	 * later.
1411 	 */
1412 	bzero(ui->ui_x1, sizeof(ui->ui_x1));
1413 	ui->ui_pr = pr;
1414 	ui->ui_src = laddr;
1415 	ui->ui_dst = faddr;
1416 	ui->ui_sport = lport;
1417 	ui->ui_dport = fport;
1418 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1419 	if (pr == IPPROTO_UDPLITE) {
1420 		struct udpcb *up;
1421 		uint16_t plen;
1422 
1423 		up = intoudpcb(inp);
1424 		cscov = up->u_txcslen;
1425 		plen = (u_short)len + sizeof(struct udphdr);
1426 		if (cscov >= plen)
1427 			cscov = 0;
1428 		ui->ui_len = htons(plen);
1429 		ui->ui_ulen = htons(cscov);
1430 		/*
1431 		 * For UDP-Lite, checksum coverage length of zero means
1432 		 * the entire UDPLite packet is covered by the checksum.
1433 		 */
1434 		cscov_partial = (cscov == 0) ? 0 : 1;
1435 	}
1436 
1437 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1438 		ipflags |= IP_ROUTETOIF;
1439 	if (inp->inp_socket->so_options & SO_BROADCAST)
1440 		ipflags |= IP_ALLOWBROADCAST;
1441 	if (inp->inp_flags & INP_ONESBCAST)
1442 		ipflags |= IP_SENDONES;
1443 
1444 #ifdef MAC
1445 	mac_inpcb_create_mbuf(inp, m);
1446 #endif
1447 
1448 	/*
1449 	 * Set up checksum and output datagram.
1450 	 */
1451 	ui->ui_sum = 0;
1452 	if (pr == IPPROTO_UDPLITE) {
1453 		if (inp->inp_flags & INP_ONESBCAST)
1454 			faddr.s_addr = INADDR_BROADCAST;
1455 		if (cscov_partial) {
1456 			if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1457 				ui->ui_sum = 0xffff;
1458 		} else {
1459 			if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1460 				ui->ui_sum = 0xffff;
1461 		}
1462 	} else if (V_udp_cksum) {
1463 		if (inp->inp_flags & INP_ONESBCAST)
1464 			faddr.s_addr = INADDR_BROADCAST;
1465 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1466 		    htons((u_short)len + sizeof(struct udphdr) + pr));
1467 		m->m_pkthdr.csum_flags = CSUM_UDP;
1468 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1469 	}
1470 	/*
1471 	 * After finishing the checksum computation, fill the remaining fields
1472 	 * of udpiphdr.
1473 	 */
1474 	((struct ip *)ui)->ip_v = IPVERSION;
1475 	((struct ip *)ui)->ip_tos = tos;
1476 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1477 	if (inp->inp_flags & INP_DONTFRAG)
1478 		((struct ip *)ui)->ip_off |= htons(IP_DF);
1479 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;
1480 	UDPSTAT_INC(udps_opackets);
1481 
1482 	/*
1483 	 * Setup flowid / RSS information for outbound socket.
1484 	 *
1485 	 * Once the UDP code decides to set a flowid some other way,
1486 	 * this allows the flowid to be overridden by userland.
1487 	 */
1488 	if (flowtype != M_HASHTYPE_NONE) {
1489 		m->m_pkthdr.flowid = flowid;
1490 		M_HASHTYPE_SET(m, flowtype);
1491 	}
1492 #if defined(ROUTE_MPATH) || defined(RSS)
1493 	else if (CALC_FLOWID_OUTBOUND_SENDTO) {
1494 		uint32_t hash_val, hash_type;
1495 
1496 		hash_val = fib4_calc_packet_hash(laddr, faddr,
1497 		    lport, fport, pr, &hash_type);
1498 		m->m_pkthdr.flowid = hash_val;
1499 		M_HASHTYPE_SET(m, hash_type);
1500 	}
1501 
1502 	/*
1503 	 * Don't override with the inp cached flowid value.
1504 	 *
1505 	 * Depending upon the kind of send being done, the inp
1506 	 * flowid/flowtype values may actually not be appropriate
1507 	 * for this particular socket send.
1508 	 *
1509 	 * We should either leave the flowid at zero (which is what is
1510 	 * currently done) or set it to some software generated
1511 	 * hash value based on the packet contents.
1512 	 */
1513 	ipflags |= IP_NODEFAULTFLOWID;
1514 #endif	/* RSS */
1515 
1516 	if (pr == IPPROTO_UDPLITE)
1517 		UDPLITE_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1518 	else
1519 		UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1520 	error = ip_output(m, inp->inp_options,
1521 	    use_cached_route ? &inp->inp_route : NULL, ipflags,
1522 	    inp->inp_moptions, inp);
1523 	INP_UNLOCK(inp);
1524 	NET_EPOCH_EXIT(et);
1525 	return (error);
1526 
1527 release:
1528 	INP_UNLOCK(inp);
1529 	NET_EPOCH_EXIT(et);
1530 	m_freem(m);
1531 	return (error);
1532 }
1533 
1534 void
udp_abort(struct socket * so)1535 udp_abort(struct socket *so)
1536 {
1537 	struct inpcb *inp;
1538 	struct inpcbinfo *pcbinfo;
1539 
1540 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1541 	inp = sotoinpcb(so);
1542 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1543 	INP_WLOCK(inp);
1544 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1545 		INP_HASH_WLOCK(pcbinfo);
1546 		in_pcbdisconnect(inp);
1547 		INP_HASH_WUNLOCK(pcbinfo);
1548 		soisdisconnected(so);
1549 	}
1550 	INP_WUNLOCK(inp);
1551 }
1552 
1553 static int
udp_attach(struct socket * so,int proto,struct thread * td)1554 udp_attach(struct socket *so, int proto, struct thread *td)
1555 {
1556 	static uint32_t udp_flowid;
1557 	struct inpcbinfo *pcbinfo;
1558 	struct inpcb *inp;
1559 	struct udpcb *up;
1560 	int error;
1561 
1562 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1563 	inp = sotoinpcb(so);
1564 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1565 	error = soreserve(so, udp_sendspace, udp_recvspace);
1566 	if (error)
1567 		return (error);
1568 	error = in_pcballoc(so, pcbinfo);
1569 	if (error)
1570 		return (error);
1571 
1572 	inp = sotoinpcb(so);
1573 	inp->inp_ip_ttl = V_ip_defttl;
1574 	inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1575 	inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1576 	up = intoudpcb(inp);
1577 	bzero(&up->u_start_zero, u_zero_size);
1578 	INP_WUNLOCK(inp);
1579 
1580 	return (0);
1581 }
1582 #endif /* INET */
1583 
1584 int
udp_set_kernel_tunneling(struct socket * so,udp_tun_func_t f,udp_tun_icmp_t i,void * ctx)1585 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1586 {
1587 	struct inpcb *inp;
1588 	struct udpcb *up;
1589 
1590 	KASSERT(so->so_type == SOCK_DGRAM,
1591 	    ("udp_set_kernel_tunneling: !dgram"));
1592 	inp = sotoinpcb(so);
1593 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1594 	INP_WLOCK(inp);
1595 	up = intoudpcb(inp);
1596 	if ((f != NULL || i != NULL) && ((up->u_tun_func != NULL) ||
1597 	    (up->u_icmp_func != NULL))) {
1598 		INP_WUNLOCK(inp);
1599 		return (EBUSY);
1600 	}
1601 	up->u_tun_func = f;
1602 	up->u_icmp_func = i;
1603 	up->u_tun_ctx = ctx;
1604 	INP_WUNLOCK(inp);
1605 	return (0);
1606 }
1607 
1608 #ifdef INET
1609 static int
udp_bind(struct socket * so,struct sockaddr * nam,struct thread * td)1610 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1611 {
1612 	struct inpcb *inp;
1613 	struct inpcbinfo *pcbinfo;
1614 	struct sockaddr_in *sinp;
1615 	int error;
1616 
1617 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1618 	inp = sotoinpcb(so);
1619 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1620 
1621 	sinp = (struct sockaddr_in *)nam;
1622 	if (nam->sa_family != AF_INET) {
1623 		/*
1624 		 * Preserve compatibility with old programs.
1625 		 */
1626 		if (nam->sa_family != AF_UNSPEC ||
1627 		    nam->sa_len < offsetof(struct sockaddr_in, sin_zero) ||
1628 		    sinp->sin_addr.s_addr != INADDR_ANY)
1629 			return (EAFNOSUPPORT);
1630 		nam->sa_family = AF_INET;
1631 	}
1632 	if (nam->sa_len != sizeof(struct sockaddr_in))
1633 		return (EINVAL);
1634 
1635 	INP_WLOCK(inp);
1636 	INP_HASH_WLOCK(pcbinfo);
1637 	error = in_pcbbind(inp, sinp, V_udp_bind_all_fibs ? 0 : INPBIND_FIB,
1638 	    td->td_ucred);
1639 	INP_HASH_WUNLOCK(pcbinfo);
1640 	INP_WUNLOCK(inp);
1641 	return (error);
1642 }
1643 
1644 static void
udp_close(struct socket * so)1645 udp_close(struct socket *so)
1646 {
1647 	struct inpcb *inp;
1648 	struct inpcbinfo *pcbinfo;
1649 
1650 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1651 	inp = sotoinpcb(so);
1652 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1653 	INP_WLOCK(inp);
1654 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1655 		INP_HASH_WLOCK(pcbinfo);
1656 		in_pcbdisconnect(inp);
1657 		INP_HASH_WUNLOCK(pcbinfo);
1658 		soisdisconnected(so);
1659 	}
1660 	INP_WUNLOCK(inp);
1661 }
1662 
1663 static int
udp_connect(struct socket * so,struct sockaddr * nam,struct thread * td)1664 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1665 {
1666 	struct epoch_tracker et;
1667 	struct inpcb *inp;
1668 	struct inpcbinfo *pcbinfo;
1669 	struct sockaddr_in *sin;
1670 	int error;
1671 
1672 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1673 	inp = sotoinpcb(so);
1674 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1675 
1676 	sin = (struct sockaddr_in *)nam;
1677 	if (sin->sin_family != AF_INET)
1678 		return (EAFNOSUPPORT);
1679 	if (sin->sin_len != sizeof(*sin))
1680 		return (EINVAL);
1681 
1682 	INP_WLOCK(inp);
1683 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1684 		INP_WUNLOCK(inp);
1685 		return (EISCONN);
1686 	}
1687 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1688 	if (error != 0) {
1689 		INP_WUNLOCK(inp);
1690 		return (error);
1691 	}
1692 	NET_EPOCH_ENTER(et);
1693 	INP_HASH_WLOCK(pcbinfo);
1694 	error = in_pcbconnect(inp, sin, td->td_ucred);
1695 	INP_HASH_WUNLOCK(pcbinfo);
1696 	NET_EPOCH_EXIT(et);
1697 	if (error == 0)
1698 		soisconnected(so);
1699 	INP_WUNLOCK(inp);
1700 	return (error);
1701 }
1702 
1703 static void
udp_detach(struct socket * so)1704 udp_detach(struct socket *so)
1705 {
1706 	struct inpcb *inp;
1707 
1708 	inp = sotoinpcb(so);
1709 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1710 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1711 	    ("udp_detach: not disconnected"));
1712 	INP_WLOCK(inp);
1713 	in_pcbfree(inp);
1714 }
1715 
1716 int
udp_disconnect(struct socket * so)1717 udp_disconnect(struct socket *so)
1718 {
1719 	struct inpcb *inp;
1720 	struct inpcbinfo *pcbinfo;
1721 
1722 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1723 	inp = sotoinpcb(so);
1724 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1725 	INP_WLOCK(inp);
1726 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1727 		INP_WUNLOCK(inp);
1728 		return (ENOTCONN);
1729 	}
1730 	INP_HASH_WLOCK(pcbinfo);
1731 	in_pcbdisconnect(inp);
1732 	INP_HASH_WUNLOCK(pcbinfo);
1733 	SOCK_LOCK(so);
1734 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1735 	SOCK_UNLOCK(so);
1736 	INP_WUNLOCK(inp);
1737 	return (0);
1738 }
1739 #endif /* INET */
1740 
1741 int
udp_shutdown(struct socket * so,enum shutdown_how how)1742 udp_shutdown(struct socket *so, enum shutdown_how how)
1743 {
1744 	int error;
1745 
1746 	SOCK_LOCK(so);
1747 	if (!(so->so_state & SS_ISCONNECTED))
1748 		/*
1749 		 * POSIX mandates us to just return ENOTCONN when shutdown(2) is
1750 		 * invoked on a datagram sockets, however historically we would
1751 		 * actually tear socket down.  This is known to be leveraged by
1752 		 * some applications to unblock process waiting in recv(2) by
1753 		 * other process that it shares that socket with.  Try to meet
1754 		 * both backward-compatibility and POSIX requirements by forcing
1755 		 * ENOTCONN but still flushing buffers and performing wakeup(9).
1756 		 *
1757 		 * XXXGL: it remains unknown what applications expect this
1758 		 * behavior and is this isolated to unix/dgram or inet/dgram or
1759 		 * both.  See: D10351, D3039.
1760 		 */
1761 		error = ENOTCONN;
1762 	else
1763 		error = 0;
1764 	SOCK_UNLOCK(so);
1765 
1766 	switch (how) {
1767 	case SHUT_RD:
1768 		sorflush(so);
1769 		break;
1770 	case SHUT_RDWR:
1771 		sorflush(so);
1772 		/* FALLTHROUGH */
1773 	case SHUT_WR:
1774 		socantsendmore(so);
1775 	}
1776 
1777 	return (error);
1778 }
1779 
1780 #ifdef INET
1781 #define	UDP_PROTOSW							\
1782 	.pr_type =		SOCK_DGRAM,				\
1783 	.pr_flags =		PR_ATOMIC | PR_ADDR | PR_CAPATTACH,	\
1784 	.pr_ctloutput =		udp_ctloutput,				\
1785 	.pr_abort =		udp_abort,				\
1786 	.pr_attach =		udp_attach,				\
1787 	.pr_bind =		udp_bind,				\
1788 	.pr_connect =		udp_connect,				\
1789 	.pr_control =		in_control,				\
1790 	.pr_detach =		udp_detach,				\
1791 	.pr_disconnect =	udp_disconnect,				\
1792 	.pr_peeraddr =		in_getpeeraddr,				\
1793 	.pr_send =		udp_send,				\
1794 	.pr_soreceive =		soreceive_dgram,			\
1795 	.pr_sosend =		sosend_dgram,				\
1796 	.pr_shutdown =		udp_shutdown,				\
1797 	.pr_sockaddr =		in_getsockaddr,				\
1798 	.pr_sosetlabel =	in_pcbsosetlabel,			\
1799 	.pr_close =		udp_close
1800 
1801 struct protosw udp_protosw = {
1802 	.pr_protocol =		IPPROTO_UDP,
1803 	UDP_PROTOSW
1804 };
1805 
1806 struct protosw udplite_protosw = {
1807 	.pr_protocol =		IPPROTO_UDPLITE,
1808 	UDP_PROTOSW
1809 };
1810 
1811 static void
udp_init(void * arg __unused)1812 udp_init(void *arg __unused)
1813 {
1814 
1815 	IPPROTO_REGISTER(IPPROTO_UDP, udp_input, udp_ctlinput);
1816 	IPPROTO_REGISTER(IPPROTO_UDPLITE, udp_input, udplite_ctlinput);
1817 }
1818 SYSINIT(udp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, udp_init, NULL);
1819 #endif /* INET */
1820