xref: /freebsd/sys/netinet/udp_usrreq.c (revision f1951fd745b894fe6586c298874af98544a5e272)
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  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include "opt_inet.h"
45 #include "opt_inet6.h"
46 #include "opt_ipsec.h"
47 #include "opt_rss.h"
48 
49 #include <sys/param.h>
50 #include <sys/domain.h>
51 #include <sys/eventhandler.h>
52 #include <sys/jail.h>
53 #include <sys/kernel.h>
54 #include <sys/lock.h>
55 #include <sys/malloc.h>
56 #include <sys/mbuf.h>
57 #include <sys/priv.h>
58 #include <sys/proc.h>
59 #include <sys/protosw.h>
60 #include <sys/sdt.h>
61 #include <sys/signalvar.h>
62 #include <sys/socket.h>
63 #include <sys/socketvar.h>
64 #include <sys/sx.h>
65 #include <sys/sysctl.h>
66 #include <sys/syslog.h>
67 #include <sys/systm.h>
68 
69 #include <vm/uma.h>
70 
71 #include <net/if.h>
72 #include <net/if_var.h>
73 #include <net/route.h>
74 #include <net/rss_config.h>
75 
76 #include <netinet/in.h>
77 #include <netinet/in_kdtrace.h>
78 #include <netinet/in_pcb.h>
79 #include <netinet/in_systm.h>
80 #include <netinet/in_var.h>
81 #include <netinet/ip.h>
82 #ifdef INET6
83 #include <netinet/ip6.h>
84 #endif
85 #include <netinet/ip_icmp.h>
86 #include <netinet/icmp_var.h>
87 #include <netinet/ip_var.h>
88 #include <netinet/ip_options.h>
89 #ifdef INET6
90 #include <netinet6/ip6_var.h>
91 #endif
92 #include <netinet/udp.h>
93 #include <netinet/udp_var.h>
94 #include <netinet/udplite.h>
95 #include <netinet/in_rss.h>
96 
97 #include <netipsec/ipsec_support.h>
98 
99 #include <machine/in_cksum.h>
100 
101 #include <security/mac/mac_framework.h>
102 
103 /*
104  * UDP and UDP-Lite protocols implementation.
105  * Per RFC 768, August, 1980.
106  * Per RFC 3828, July, 2004.
107  */
108 
109 /*
110  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
111  * removes the only data integrity mechanism for packets and malformed
112  * packets that would otherwise be discarded due to bad checksums, and may
113  * cause problems (especially for NFS data blocks).
114  */
115 VNET_DEFINE(int, udp_cksum) = 1;
116 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
117     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
118 
119 int	udp_log_in_vain = 0;
120 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
121     &udp_log_in_vain, 0, "Log all incoming UDP packets");
122 
123 VNET_DEFINE(int, udp_blackhole) = 0;
124 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
125     &VNET_NAME(udp_blackhole), 0,
126     "Do not send port unreachables for refused connects");
127 
128 u_long	udp_sendspace = 9216;		/* really max datagram size */
129 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
130     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
131 
132 u_long	udp_recvspace = 40 * (1024 +
133 #ifdef INET6
134 				      sizeof(struct sockaddr_in6)
135 #else
136 				      sizeof(struct sockaddr_in)
137 #endif
138 				      );	/* 40 1K datagrams */
139 
140 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
141     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
142 
143 VNET_DEFINE(struct inpcbhead, udb);		/* from udp_var.h */
144 VNET_DEFINE(struct inpcbinfo, udbinfo);
145 VNET_DEFINE(struct inpcbhead, ulitecb);
146 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
147 VNET_DEFINE_STATIC(uma_zone_t, udpcb_zone);
148 #define	V_udpcb_zone			VNET(udpcb_zone)
149 
150 #ifndef UDBHASHSIZE
151 #define	UDBHASHSIZE	128
152 #endif
153 
154 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
155 VNET_PCPUSTAT_SYSINIT(udpstat);
156 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
157     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
158 
159 #ifdef VIMAGE
160 VNET_PCPUSTAT_SYSUNINIT(udpstat);
161 #endif /* VIMAGE */
162 #ifdef INET
163 static void	udp_detach(struct socket *so);
164 static int	udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
165 		    struct mbuf *, struct thread *);
166 #endif
167 
168 static void
169 udp_zone_change(void *tag)
170 {
171 
172 	uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
173 	uma_zone_set_max(V_udpcb_zone, maxsockets);
174 }
175 
176 static int
177 udp_inpcb_init(void *mem, int size, int flags)
178 {
179 	struct inpcb *inp;
180 
181 	inp = mem;
182 	INP_LOCK_INIT(inp, "inp", "udpinp");
183 	return (0);
184 }
185 
186 static int
187 udplite_inpcb_init(void *mem, int size, int flags)
188 {
189 	struct inpcb *inp;
190 
191 	inp = mem;
192 	INP_LOCK_INIT(inp, "inp", "udpliteinp");
193 	return (0);
194 }
195 
196 void
197 udp_init(void)
198 {
199 
200 	/*
201 	 * For now default to 2-tuple UDP hashing - until the fragment
202 	 * reassembly code can also update the flowid.
203 	 *
204 	 * Once we can calculate the flowid that way and re-establish
205 	 * a 4-tuple, flip this to 4-tuple.
206 	 */
207 	in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
208 	    "udp_inpcb", udp_inpcb_init, IPI_HASHFIELDS_2TUPLE);
209 	V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
210 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
211 	uma_zone_set_max(V_udpcb_zone, maxsockets);
212 	uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
213 	EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
214 	    EVENTHANDLER_PRI_ANY);
215 }
216 
217 void
218 udplite_init(void)
219 {
220 
221 	in_pcbinfo_init(&V_ulitecbinfo, "udplite", &V_ulitecb, UDBHASHSIZE,
222 	    UDBHASHSIZE, "udplite_inpcb", udplite_inpcb_init,
223 	    IPI_HASHFIELDS_2TUPLE);
224 }
225 
226 /*
227  * Kernel module interface for updating udpstat.  The argument is an index
228  * into udpstat treated as an array of u_long.  While this encodes the
229  * general layout of udpstat into the caller, it doesn't encode its location,
230  * so that future changes to add, for example, per-CPU stats support won't
231  * cause binary compatibility problems for kernel modules.
232  */
233 void
234 kmod_udpstat_inc(int statnum)
235 {
236 
237 	counter_u64_add(VNET(udpstat)[statnum], 1);
238 }
239 
240 int
241 udp_newudpcb(struct inpcb *inp)
242 {
243 	struct udpcb *up;
244 
245 	up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
246 	if (up == NULL)
247 		return (ENOBUFS);
248 	inp->inp_ppcb = up;
249 	return (0);
250 }
251 
252 void
253 udp_discardcb(struct udpcb *up)
254 {
255 
256 	uma_zfree(V_udpcb_zone, up);
257 }
258 
259 #ifdef VIMAGE
260 static void
261 udp_destroy(void *unused __unused)
262 {
263 
264 	in_pcbinfo_destroy(&V_udbinfo);
265 	uma_zdestroy(V_udpcb_zone);
266 }
267 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
268 
269 static void
270 udplite_destroy(void *unused __unused)
271 {
272 
273 	in_pcbinfo_destroy(&V_ulitecbinfo);
274 }
275 VNET_SYSUNINIT(udplite, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udplite_destroy,
276     NULL);
277 #endif
278 
279 #ifdef INET
280 /*
281  * Subroutine of udp_input(), which appends the provided mbuf chain to the
282  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
283  * contains the source address.  If the socket ends up being an IPv6 socket,
284  * udp_append() will convert to a sockaddr_in6 before passing the address
285  * into the socket code.
286  *
287  * In the normal case udp_append() will return 0, indicating that you
288  * must unlock the inp. However if a tunneling protocol is in place we increment
289  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
290  * then decrement the reference count. If the inp_rele returns 1, indicating the
291  * inp is gone, we return that to the caller to tell them *not* to unlock
292  * the inp. In the case of multi-cast this will cause the distribution
293  * to stop (though most tunneling protocols known currently do *not* use
294  * multicast).
295  */
296 static int
297 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
298     struct sockaddr_in *udp_in)
299 {
300 	struct sockaddr *append_sa;
301 	struct socket *so;
302 	struct mbuf *tmpopts, *opts = NULL;
303 #ifdef INET6
304 	struct sockaddr_in6 udp_in6;
305 #endif
306 	struct udpcb *up;
307 
308 	INP_LOCK_ASSERT(inp);
309 
310 	/*
311 	 * Engage the tunneling protocol.
312 	 */
313 	up = intoudpcb(inp);
314 	if (up->u_tun_func != NULL) {
315 		in_pcbref(inp);
316 		INP_RUNLOCK(inp);
317 		(*up->u_tun_func)(n, off, inp, (struct sockaddr *)&udp_in[0],
318 		    up->u_tun_ctx);
319 		INP_RLOCK(inp);
320 		return (in_pcbrele_rlocked(inp));
321 	}
322 
323 	off += sizeof(struct udphdr);
324 
325 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
326 	/* Check AH/ESP integrity. */
327 	if (IPSEC_ENABLED(ipv4) &&
328 	    IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
329 		m_freem(n);
330 		return (0);
331 	}
332 	if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
333 		if (IPSEC_ENABLED(ipv4) &&
334 		    UDPENCAP_INPUT(n, off, AF_INET) != 0)
335 			return (0);	/* Consumed. */
336 	}
337 #endif /* IPSEC */
338 #ifdef MAC
339 	if (mac_inpcb_check_deliver(inp, n) != 0) {
340 		m_freem(n);
341 		return (0);
342 	}
343 #endif /* MAC */
344 	if (inp->inp_flags & INP_CONTROLOPTS ||
345 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
346 #ifdef INET6
347 		if (inp->inp_vflag & INP_IPV6)
348 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
349 		else
350 #endif /* INET6 */
351 			ip_savecontrol(inp, &opts, ip, n);
352 	}
353 	if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
354 		tmpopts = sbcreatecontrol((caddr_t)&udp_in[1],
355 			sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP);
356 		if (tmpopts) {
357 			if (opts) {
358 				tmpopts->m_next = opts;
359 				opts = tmpopts;
360 			} else
361 				opts = tmpopts;
362 		}
363 	}
364 #ifdef INET6
365 	if (inp->inp_vflag & INP_IPV6) {
366 		bzero(&udp_in6, sizeof(udp_in6));
367 		udp_in6.sin6_len = sizeof(udp_in6);
368 		udp_in6.sin6_family = AF_INET6;
369 		in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
370 		append_sa = (struct sockaddr *)&udp_in6;
371 	} else
372 #endif /* INET6 */
373 		append_sa = (struct sockaddr *)&udp_in[0];
374 	m_adj(n, off);
375 
376 	so = inp->inp_socket;
377 	SOCKBUF_LOCK(&so->so_rcv);
378 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
379 		SOCKBUF_UNLOCK(&so->so_rcv);
380 		m_freem(n);
381 		if (opts)
382 			m_freem(opts);
383 		UDPSTAT_INC(udps_fullsock);
384 	} else
385 		sorwakeup_locked(so);
386 	return (0);
387 }
388 
389 int
390 udp_input(struct mbuf **mp, int *offp, int proto)
391 {
392 	struct ip *ip;
393 	struct udphdr *uh;
394 	struct ifnet *ifp;
395 	struct inpcb *inp;
396 	uint16_t len, ip_len;
397 	struct inpcbinfo *pcbinfo;
398 	struct ip save_ip;
399 	struct sockaddr_in udp_in[2];
400 	struct mbuf *m;
401 	struct m_tag *fwd_tag;
402 	struct epoch_tracker et;
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[0], sizeof(struct sockaddr_in) * 2);
446 	udp_in[0].sin_len = sizeof(struct sockaddr_in);
447 	udp_in[0].sin_family = AF_INET;
448 	udp_in[0].sin_port = uh->uh_sport;
449 	udp_in[0].sin_addr = ip->ip_src;
450 	udp_in[1].sin_len = sizeof(struct sockaddr_in);
451 	udp_in[1].sin_family = AF_INET;
452 	udp_in[1].sin_port = uh->uh_dport;
453 	udp_in[1].sin_addr = ip->ip_dst;
454 
455 	/*
456 	 * Make mbuf data length reflect UDP length.  If not enough data to
457 	 * reflect UDP length, drop.
458 	 */
459 	len = ntohs((u_short)uh->uh_ulen);
460 	ip_len = ntohs(ip->ip_len) - iphlen;
461 	if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
462 		/* Zero means checksum over the complete packet. */
463 		if (len == 0)
464 			len = ip_len;
465 		cscov_partial = 0;
466 	}
467 	if (ip_len != len) {
468 		if (len > ip_len || len < sizeof(struct udphdr)) {
469 			UDPSTAT_INC(udps_badlen);
470 			goto badunlocked;
471 		}
472 		if (proto == IPPROTO_UDP)
473 			m_adj(m, len - ip_len);
474 	}
475 
476 	/*
477 	 * Save a copy of the IP header in case we want restore it for
478 	 * sending an ICMP error message in response.
479 	 */
480 	if (!V_udp_blackhole)
481 		save_ip = *ip;
482 	else
483 		memset(&save_ip, 0, sizeof(save_ip));
484 
485 	/*
486 	 * Checksum extended UDP header and data.
487 	 */
488 	if (uh->uh_sum) {
489 		u_short uh_sum;
490 
491 		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
492 		    !cscov_partial) {
493 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
494 				uh_sum = m->m_pkthdr.csum_data;
495 			else
496 				uh_sum = in_pseudo(ip->ip_src.s_addr,
497 				    ip->ip_dst.s_addr, htonl((u_short)len +
498 				    m->m_pkthdr.csum_data + proto));
499 			uh_sum ^= 0xffff;
500 		} else {
501 			char b[9];
502 
503 			bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
504 			bzero(((struct ipovly *)ip)->ih_x1, 9);
505 			((struct ipovly *)ip)->ih_len = (proto == IPPROTO_UDP) ?
506 			    uh->uh_ulen : htons(ip_len);
507 			uh_sum = in_cksum(m, len + sizeof (struct ip));
508 			bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
509 		}
510 		if (uh_sum) {
511 			UDPSTAT_INC(udps_badsum);
512 			m_freem(m);
513 			return (IPPROTO_DONE);
514 		}
515 	} else {
516 		if (proto == IPPROTO_UDP) {
517 			UDPSTAT_INC(udps_nosum);
518 		} else {
519 			/* UDPLite requires a checksum */
520 			/* XXX: What is the right UDPLite MIB counter here? */
521 			m_freem(m);
522 			return (IPPROTO_DONE);
523 		}
524 	}
525 
526 	pcbinfo = udp_get_inpcbinfo(proto);
527 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
528 	    in_broadcast(ip->ip_dst, ifp)) {
529 		struct inpcb *last;
530 		struct inpcbhead *pcblist;
531 		struct ip_moptions *imo;
532 
533 		INP_INFO_RLOCK_ET(pcbinfo, et);
534 		pcblist = udp_get_pcblist(proto);
535 		last = NULL;
536 		CK_LIST_FOREACH(inp, pcblist, inp_list) {
537 			if (inp->inp_lport != uh->uh_dport)
538 				continue;
539 #ifdef INET6
540 			if ((inp->inp_vflag & INP_IPV4) == 0)
541 				continue;
542 #endif
543 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
544 			    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
545 				continue;
546 			if (inp->inp_faddr.s_addr != INADDR_ANY &&
547 			    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
548 				continue;
549 			if (inp->inp_fport != 0 &&
550 			    inp->inp_fport != uh->uh_sport)
551 				continue;
552 
553 			INP_RLOCK(inp);
554 
555 			/*
556 			 * XXXRW: Because we weren't holding either the inpcb
557 			 * or the hash lock when we checked for a match
558 			 * before, we should probably recheck now that the
559 			 * inpcb lock is held.
560 			 */
561 
562 			/*
563 			 * Handle socket delivery policy for any-source
564 			 * and source-specific multicast. [RFC3678]
565 			 */
566 			imo = inp->inp_moptions;
567 			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
568 				struct sockaddr_in	 group;
569 				int			 blocked;
570 				if (imo == NULL) {
571 					INP_RUNLOCK(inp);
572 					continue;
573 				}
574 				bzero(&group, sizeof(struct sockaddr_in));
575 				group.sin_len = sizeof(struct sockaddr_in);
576 				group.sin_family = AF_INET;
577 				group.sin_addr = ip->ip_dst;
578 
579 				blocked = imo_multi_filter(imo, ifp,
580 					(struct sockaddr *)&group,
581 					(struct sockaddr *)&udp_in[0]);
582 				if (blocked != MCAST_PASS) {
583 					if (blocked == MCAST_NOTGMEMBER)
584 						IPSTAT_INC(ips_notmember);
585 					if (blocked == MCAST_NOTSMEMBER ||
586 					    blocked == MCAST_MUTED)
587 						UDPSTAT_INC(udps_filtermcast);
588 					INP_RUNLOCK(inp);
589 					continue;
590 				}
591 			}
592 			if (last != NULL) {
593 				struct mbuf *n;
594 
595 				if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) !=
596 				    NULL) {
597 					UDP_PROBE(receive, NULL, last, ip,
598 					    last, uh);
599 					if (udp_append(last, ip, n, iphlen,
600 						udp_in)) {
601 						goto inp_lost;
602 					}
603 				}
604 				INP_RUNLOCK(last);
605 			}
606 			last = inp;
607 			/*
608 			 * Don't look for additional matches if this one does
609 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
610 			 * socket options set.  This heuristic avoids
611 			 * searching through all pcbs in the common case of a
612 			 * non-shared port.  It assumes that an application
613 			 * will never clear these options after setting them.
614 			 */
615 			if ((last->inp_socket->so_options &
616 			    (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0)
617 				break;
618 		}
619 
620 		if (last == NULL) {
621 			/*
622 			 * No matching pcb found; discard datagram.  (No need
623 			 * to send an ICMP Port Unreachable for a broadcast
624 			 * or multicast datgram.)
625 			 */
626 			UDPSTAT_INC(udps_noportbcast);
627 			if (inp)
628 				INP_RUNLOCK(inp);
629 			INP_INFO_RUNLOCK_ET(pcbinfo, et);
630 			goto badunlocked;
631 		}
632 		UDP_PROBE(receive, NULL, last, ip, last, uh);
633 		if (udp_append(last, ip, m, iphlen, udp_in) == 0)
634 			INP_RUNLOCK(last);
635 	inp_lost:
636 		INP_INFO_RUNLOCK_ET(pcbinfo, et);
637 		return (IPPROTO_DONE);
638 	}
639 
640 	/*
641 	 * Locate pcb for datagram.
642 	 */
643 
644 	/*
645 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
646 	 */
647 	if ((m->m_flags & M_IP_NEXTHOP) &&
648 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
649 		struct sockaddr_in *next_hop;
650 
651 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
652 
653 		/*
654 		 * Transparently forwarded. Pretend to be the destination.
655 		 * Already got one like this?
656 		 */
657 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
658 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
659 		if (!inp) {
660 			/*
661 			 * It's new.  Try to find the ambushing socket.
662 			 * Because we've rewritten the destination address,
663 			 * any hardware-generated hash is ignored.
664 			 */
665 			inp = in_pcblookup(pcbinfo, ip->ip_src,
666 			    uh->uh_sport, next_hop->sin_addr,
667 			    next_hop->sin_port ? htons(next_hop->sin_port) :
668 			    uh->uh_dport, INPLOOKUP_WILDCARD |
669 			    INPLOOKUP_RLOCKPCB, ifp);
670 		}
671 		/* Remove the tag from the packet. We don't need it anymore. */
672 		m_tag_delete(m, fwd_tag);
673 		m->m_flags &= ~M_IP_NEXTHOP;
674 	} else
675 		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
676 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
677 		    INPLOOKUP_RLOCKPCB, ifp, m);
678 	if (inp == NULL) {
679 		if (udp_log_in_vain) {
680 			char src[INET_ADDRSTRLEN];
681 			char dst[INET_ADDRSTRLEN];
682 
683 			log(LOG_INFO,
684 			    "Connection attempt to UDP %s:%d from %s:%d\n",
685 			    inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
686 			    inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
687 		}
688 		UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
689 		UDPSTAT_INC(udps_noport);
690 		if (m->m_flags & (M_BCAST | M_MCAST)) {
691 			UDPSTAT_INC(udps_noportbcast);
692 			goto badunlocked;
693 		}
694 		if (V_udp_blackhole)
695 			goto badunlocked;
696 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
697 			goto badunlocked;
698 		*ip = save_ip;
699 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
700 		return (IPPROTO_DONE);
701 	}
702 
703 	/*
704 	 * Check the minimum TTL for socket.
705 	 */
706 	INP_RLOCK_ASSERT(inp);
707 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
708 		UDP_PROBE(receive, NULL, inp, ip, inp, uh);
709 		INP_RUNLOCK(inp);
710 		m_freem(m);
711 		return (IPPROTO_DONE);
712 	}
713 	if (cscov_partial) {
714 		struct udpcb *up;
715 
716 		up = intoudpcb(inp);
717 		if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
718 			INP_RUNLOCK(inp);
719 			m_freem(m);
720 			return (IPPROTO_DONE);
721 		}
722 	}
723 
724 	UDP_PROBE(receive, NULL, inp, ip, inp, uh);
725 	if (udp_append(inp, ip, m, iphlen, udp_in) == 0)
726 		INP_RUNLOCK(inp);
727 	return (IPPROTO_DONE);
728 
729 badunlocked:
730 	m_freem(m);
731 	return (IPPROTO_DONE);
732 }
733 #endif /* INET */
734 
735 /*
736  * Notify a udp user of an asynchronous error; just wake up so that they can
737  * collect error status.
738  */
739 struct inpcb *
740 udp_notify(struct inpcb *inp, int errno)
741 {
742 
743 	/*
744 	 * While udp_ctlinput() always calls udp_notify() with a read lock
745 	 * when invoking it directly, in_pcbnotifyall() currently uses write
746 	 * locks due to sharing code with TCP.  For now, accept either a read
747 	 * or a write lock, but a read lock is sufficient.
748 	 */
749 	INP_LOCK_ASSERT(inp);
750 	if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
751 	     errno == EHOSTDOWN) && inp->inp_route.ro_rt) {
752 		RTFREE(inp->inp_route.ro_rt);
753 		inp->inp_route.ro_rt = (struct rtentry *)NULL;
754 	}
755 
756 	inp->inp_socket->so_error = errno;
757 	sorwakeup(inp->inp_socket);
758 	sowwakeup(inp->inp_socket);
759 	return (inp);
760 }
761 
762 #ifdef INET
763 static void
764 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
765     struct inpcbinfo *pcbinfo)
766 {
767 	struct ip *ip = vip;
768 	struct udphdr *uh;
769 	struct in_addr faddr;
770 	struct inpcb *inp;
771 
772 	faddr = ((struct sockaddr_in *)sa)->sin_addr;
773 	if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
774 		return;
775 
776 	if (PRC_IS_REDIRECT(cmd)) {
777 		/* signal EHOSTDOWN, as it flushes the cached route */
778 		in_pcbnotifyall(&V_udbinfo, faddr, EHOSTDOWN, udp_notify);
779 		return;
780 	}
781 
782 	/*
783 	 * Hostdead is ugly because it goes linearly through all PCBs.
784 	 *
785 	 * XXX: We never get this from ICMP, otherwise it makes an excellent
786 	 * DoS attack on machines with many connections.
787 	 */
788 	if (cmd == PRC_HOSTDEAD)
789 		ip = NULL;
790 	else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
791 		return;
792 	if (ip != NULL) {
793 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
794 		inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
795 		    ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
796 		if (inp != NULL) {
797 			INP_RLOCK_ASSERT(inp);
798 			if (inp->inp_socket != NULL) {
799 				udp_notify(inp, inetctlerrmap[cmd]);
800 			}
801 			INP_RUNLOCK(inp);
802 		} else {
803 			inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
804 					   ip->ip_src, uh->uh_sport,
805 					   INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
806 			if (inp != NULL) {
807 				struct udpcb *up;
808 				void *ctx;
809 				udp_tun_icmp_t func;
810 
811 				up = intoudpcb(inp);
812 				ctx = up->u_tun_ctx;
813 				func = up->u_icmp_func;
814 				INP_RUNLOCK(inp);
815 				if (func != NULL)
816 					(*func)(cmd, sa, vip, ctx);
817 			}
818 		}
819 	} else
820 		in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
821 		    udp_notify);
822 }
823 void
824 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
825 {
826 
827 	return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
828 }
829 
830 void
831 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
832 {
833 
834 	return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
835 }
836 #endif /* INET */
837 
838 static int
839 udp_pcblist(SYSCTL_HANDLER_ARGS)
840 {
841 	int error, i, n;
842 	struct inpcb *inp, **inp_list;
843 	inp_gen_t gencnt;
844 	struct xinpgen xig;
845 	struct epoch_tracker et;
846 
847 	/*
848 	 * The process of preparing the PCB list is too time-consuming and
849 	 * resource-intensive to repeat twice on every request.
850 	 */
851 	if (req->oldptr == 0) {
852 		n = V_udbinfo.ipi_count;
853 		n += imax(n / 8, 10);
854 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
855 		return (0);
856 	}
857 
858 	if (req->newptr != 0)
859 		return (EPERM);
860 
861 	/*
862 	 * OK, now we're committed to doing something.
863 	 */
864 	INP_INFO_RLOCK_ET(&V_udbinfo, et);
865 	gencnt = V_udbinfo.ipi_gencnt;
866 	n = V_udbinfo.ipi_count;
867 	INP_INFO_RUNLOCK_ET(&V_udbinfo, et);
868 
869 	error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
870 		+ n * sizeof(struct xinpcb));
871 	if (error != 0)
872 		return (error);
873 
874 	xig.xig_len = sizeof xig;
875 	xig.xig_count = n;
876 	xig.xig_gen = gencnt;
877 	xig.xig_sogen = so_gencnt;
878 	error = SYSCTL_OUT(req, &xig, sizeof xig);
879 	if (error)
880 		return (error);
881 
882 	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
883 	if (inp_list == NULL)
884 		return (ENOMEM);
885 
886 	INP_INFO_RLOCK_ET(&V_udbinfo, et);
887 	for (inp = CK_LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
888 	     inp = CK_LIST_NEXT(inp, inp_list)) {
889 		INP_WLOCK(inp);
890 		if (inp->inp_gencnt <= gencnt &&
891 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
892 			in_pcbref(inp);
893 			inp_list[i++] = inp;
894 		}
895 		INP_WUNLOCK(inp);
896 	}
897 	INP_INFO_RUNLOCK_ET(&V_udbinfo, et);
898 	n = i;
899 
900 	error = 0;
901 	for (i = 0; i < n; i++) {
902 		inp = inp_list[i];
903 		INP_RLOCK(inp);
904 		if (inp->inp_gencnt <= gencnt) {
905 			struct xinpcb xi;
906 
907 			in_pcbtoxinpcb(inp, &xi);
908 			INP_RUNLOCK(inp);
909 			error = SYSCTL_OUT(req, &xi, sizeof xi);
910 		} else
911 			INP_RUNLOCK(inp);
912 	}
913 	INP_INFO_WLOCK(&V_udbinfo);
914 	for (i = 0; i < n; i++) {
915 		inp = inp_list[i];
916 		INP_RLOCK(inp);
917 		if (!in_pcbrele_rlocked(inp))
918 			INP_RUNLOCK(inp);
919 	}
920 	INP_INFO_WUNLOCK(&V_udbinfo);
921 
922 	if (!error) {
923 		/*
924 		 * Give the user an updated idea of our state.  If the
925 		 * generation differs from what we told her before, she knows
926 		 * that something happened while we were processing this
927 		 * request, and it might be necessary to retry.
928 		 */
929 		INP_INFO_RLOCK_ET(&V_udbinfo, et);
930 		xig.xig_gen = V_udbinfo.ipi_gencnt;
931 		xig.xig_sogen = so_gencnt;
932 		xig.xig_count = V_udbinfo.ipi_count;
933 		INP_INFO_RUNLOCK_ET(&V_udbinfo, et);
934 		error = SYSCTL_OUT(req, &xig, sizeof xig);
935 	}
936 	free(inp_list, M_TEMP);
937 	return (error);
938 }
939 
940 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
941     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
942     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
943 
944 #ifdef INET
945 static int
946 udp_getcred(SYSCTL_HANDLER_ARGS)
947 {
948 	struct xucred xuc;
949 	struct sockaddr_in addrs[2];
950 	struct inpcb *inp;
951 	int error;
952 
953 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
954 	if (error)
955 		return (error);
956 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
957 	if (error)
958 		return (error);
959 	inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
960 	    addrs[0].sin_addr, addrs[0].sin_port,
961 	    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
962 	if (inp != NULL) {
963 		INP_RLOCK_ASSERT(inp);
964 		if (inp->inp_socket == NULL)
965 			error = ENOENT;
966 		if (error == 0)
967 			error = cr_canseeinpcb(req->td->td_ucred, inp);
968 		if (error == 0)
969 			cru2x(inp->inp_cred, &xuc);
970 		INP_RUNLOCK(inp);
971 	} else
972 		error = ENOENT;
973 	if (error == 0)
974 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
975 	return (error);
976 }
977 
978 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
979     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
980     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
981 #endif /* INET */
982 
983 int
984 udp_ctloutput(struct socket *so, struct sockopt *sopt)
985 {
986 	struct inpcb *inp;
987 	struct udpcb *up;
988 	int isudplite, error, optval;
989 
990 	error = 0;
991 	isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
992 	inp = sotoinpcb(so);
993 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
994 	INP_WLOCK(inp);
995 	if (sopt->sopt_level != so->so_proto->pr_protocol) {
996 #ifdef INET6
997 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
998 			INP_WUNLOCK(inp);
999 			error = ip6_ctloutput(so, sopt);
1000 		}
1001 #endif
1002 #if defined(INET) && defined(INET6)
1003 		else
1004 #endif
1005 #ifdef INET
1006 		{
1007 			INP_WUNLOCK(inp);
1008 			error = ip_ctloutput(so, sopt);
1009 		}
1010 #endif
1011 		return (error);
1012 	}
1013 
1014 	switch (sopt->sopt_dir) {
1015 	case SOPT_SET:
1016 		switch (sopt->sopt_name) {
1017 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1018 #ifdef INET
1019 		case UDP_ENCAP:
1020 			if (!IPSEC_ENABLED(ipv4)) {
1021 				INP_WUNLOCK(inp);
1022 				return (ENOPROTOOPT);
1023 			}
1024 			error = UDPENCAP_PCBCTL(inp, sopt);
1025 			break;
1026 #endif /* INET */
1027 #endif /* IPSEC */
1028 		case UDPLITE_SEND_CSCOV:
1029 		case UDPLITE_RECV_CSCOV:
1030 			if (!isudplite) {
1031 				INP_WUNLOCK(inp);
1032 				error = ENOPROTOOPT;
1033 				break;
1034 			}
1035 			INP_WUNLOCK(inp);
1036 			error = sooptcopyin(sopt, &optval, sizeof(optval),
1037 			    sizeof(optval));
1038 			if (error != 0)
1039 				break;
1040 			inp = sotoinpcb(so);
1041 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1042 			INP_WLOCK(inp);
1043 			up = intoudpcb(inp);
1044 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
1045 			if ((optval != 0 && optval < 8) || (optval > 65535)) {
1046 				INP_WUNLOCK(inp);
1047 				error = EINVAL;
1048 				break;
1049 			}
1050 			if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1051 				up->u_txcslen = optval;
1052 			else
1053 				up->u_rxcslen = optval;
1054 			INP_WUNLOCK(inp);
1055 			break;
1056 		default:
1057 			INP_WUNLOCK(inp);
1058 			error = ENOPROTOOPT;
1059 			break;
1060 		}
1061 		break;
1062 	case SOPT_GET:
1063 		switch (sopt->sopt_name) {
1064 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1065 #ifdef INET
1066 		case UDP_ENCAP:
1067 			if (!IPSEC_ENABLED(ipv4)) {
1068 				INP_WUNLOCK(inp);
1069 				return (ENOPROTOOPT);
1070 			}
1071 			error = UDPENCAP_PCBCTL(inp, sopt);
1072 			break;
1073 #endif /* INET */
1074 #endif /* IPSEC */
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 	struct epoch_tracker et;
1116 	int cscov_partial = 0;
1117 	int error = 0;
1118 	int ipflags;
1119 	u_short fport, lport;
1120 	int unlock_udbinfo, unlock_inp;
1121 	u_char tos;
1122 	uint8_t pr;
1123 	uint16_t cscov = 0;
1124 	uint32_t flowid = 0;
1125 	uint8_t flowtype = M_HASHTYPE_NONE;
1126 
1127 	/*
1128 	 * udp_output() may need to temporarily bind or connect the current
1129 	 * inpcb.  As such, we don't know up front whether we will need the
1130 	 * pcbinfo lock or not.  Do any work to decide what is needed up
1131 	 * front before acquiring any locks.
1132 	 */
1133 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1134 		if (control)
1135 			m_freem(control);
1136 		m_freem(m);
1137 		return (EMSGSIZE);
1138 	}
1139 
1140 	src.sin_family = 0;
1141 	sin = (struct sockaddr_in *)addr;
1142 	if (sin == NULL ||
1143 	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1144 		INP_WLOCK(inp);
1145 		unlock_inp = UH_WLOCKED;
1146 	} else {
1147 		INP_RLOCK(inp);
1148 		unlock_inp = UH_RLOCKED;
1149 	}
1150 	tos = inp->inp_ip_tos;
1151 	if (control != NULL) {
1152 		/*
1153 		 * XXX: Currently, we assume all the optional information is
1154 		 * stored in a single mbuf.
1155 		 */
1156 		if (control->m_next) {
1157 			if (unlock_inp == UH_WLOCKED)
1158 				INP_WUNLOCK(inp);
1159 			else
1160 				INP_RUNLOCK(inp);
1161 			m_freem(control);
1162 			m_freem(m);
1163 			return (EINVAL);
1164 		}
1165 		for (; control->m_len > 0;
1166 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
1167 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1168 			cm = mtod(control, struct cmsghdr *);
1169 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1170 			    || cm->cmsg_len > control->m_len) {
1171 				error = EINVAL;
1172 				break;
1173 			}
1174 			if (cm->cmsg_level != IPPROTO_IP)
1175 				continue;
1176 
1177 			switch (cm->cmsg_type) {
1178 			case IP_SENDSRCADDR:
1179 				if (cm->cmsg_len !=
1180 				    CMSG_LEN(sizeof(struct in_addr))) {
1181 					error = EINVAL;
1182 					break;
1183 				}
1184 				bzero(&src, sizeof(src));
1185 				src.sin_family = AF_INET;
1186 				src.sin_len = sizeof(src);
1187 				src.sin_port = inp->inp_lport;
1188 				src.sin_addr =
1189 				    *(struct in_addr *)CMSG_DATA(cm);
1190 				break;
1191 
1192 			case IP_TOS:
1193 				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1194 					error = EINVAL;
1195 					break;
1196 				}
1197 				tos = *(u_char *)CMSG_DATA(cm);
1198 				break;
1199 
1200 			case IP_FLOWID:
1201 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1202 					error = EINVAL;
1203 					break;
1204 				}
1205 				flowid = *(uint32_t *) CMSG_DATA(cm);
1206 				break;
1207 
1208 			case IP_FLOWTYPE:
1209 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1210 					error = EINVAL;
1211 					break;
1212 				}
1213 				flowtype = *(uint32_t *) CMSG_DATA(cm);
1214 				break;
1215 
1216 #ifdef	RSS
1217 			case IP_RSSBUCKETID:
1218 				if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1219 					error = EINVAL;
1220 					break;
1221 				}
1222 				/* This is just a placeholder for now */
1223 				break;
1224 #endif	/* RSS */
1225 			default:
1226 				error = ENOPROTOOPT;
1227 				break;
1228 			}
1229 			if (error)
1230 				break;
1231 		}
1232 		m_freem(control);
1233 	}
1234 	if (error) {
1235 		if (unlock_inp == UH_WLOCKED)
1236 			INP_WUNLOCK(inp);
1237 		else
1238 			INP_RUNLOCK(inp);
1239 		m_freem(m);
1240 		return (error);
1241 	}
1242 
1243 	/*
1244 	 * Depending on whether or not the application has bound or connected
1245 	 * the socket, we may have to do varying levels of work.  The optimal
1246 	 * case is for a connected UDP socket, as a global lock isn't
1247 	 * required at all.
1248 	 *
1249 	 * In order to decide which we need, we require stability of the
1250 	 * inpcb binding, which we ensure by acquiring a read lock on the
1251 	 * inpcb.  This doesn't strictly follow the lock order, so we play
1252 	 * the trylock and retry game; note that we may end up with more
1253 	 * conservative locks than required the second time around, so later
1254 	 * assertions have to accept that.  Further analysis of the number of
1255 	 * misses under contention is required.
1256 	 *
1257 	 * XXXRW: Check that hash locking update here is correct.
1258 	 */
1259 	pr = inp->inp_socket->so_proto->pr_protocol;
1260 	pcbinfo = udp_get_inpcbinfo(pr);
1261 	sin = (struct sockaddr_in *)addr;
1262 	if (sin != NULL &&
1263 	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1264 		INP_HASH_WLOCK(pcbinfo);
1265 		unlock_udbinfo = UH_WLOCKED;
1266 	} else if ((sin != NULL && (
1267 	    (sin->sin_addr.s_addr == INADDR_ANY) ||
1268 	    (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1269 	    (inp->inp_laddr.s_addr == INADDR_ANY) ||
1270 	    (inp->inp_lport == 0))) ||
1271 	    (src.sin_family == AF_INET)) {
1272 		INP_HASH_RLOCK_ET(pcbinfo, et);
1273 		unlock_udbinfo = UH_RLOCKED;
1274 	} else
1275 		unlock_udbinfo = UH_UNLOCKED;
1276 
1277 	/*
1278 	 * If the IP_SENDSRCADDR control message was specified, override the
1279 	 * source address for this datagram.  Its use is invalidated if the
1280 	 * address thus specified is incomplete or clobbers other inpcbs.
1281 	 */
1282 	laddr = inp->inp_laddr;
1283 	lport = inp->inp_lport;
1284 	if (src.sin_family == AF_INET) {
1285 		INP_HASH_LOCK_ASSERT(pcbinfo);
1286 		if ((lport == 0) ||
1287 		    (laddr.s_addr == INADDR_ANY &&
1288 		     src.sin_addr.s_addr == INADDR_ANY)) {
1289 			error = EINVAL;
1290 			goto release;
1291 		}
1292 		error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1293 		    &laddr.s_addr, &lport, td->td_ucred);
1294 		if (error)
1295 			goto release;
1296 	}
1297 
1298 	/*
1299 	 * If a UDP socket has been connected, then a local address/port will
1300 	 * have been selected and bound.
1301 	 *
1302 	 * If a UDP socket has not been connected to, then an explicit
1303 	 * destination address must be used, in which case a local
1304 	 * address/port may not have been selected and bound.
1305 	 */
1306 	if (sin != NULL) {
1307 		INP_LOCK_ASSERT(inp);
1308 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1309 			error = EISCONN;
1310 			goto release;
1311 		}
1312 
1313 		/*
1314 		 * Jail may rewrite the destination address, so let it do
1315 		 * that before we use it.
1316 		 */
1317 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1318 		if (error)
1319 			goto release;
1320 
1321 		/*
1322 		 * If a local address or port hasn't yet been selected, or if
1323 		 * the destination address needs to be rewritten due to using
1324 		 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1325 		 * to do the heavy lifting.  Once a port is selected, we
1326 		 * commit the binding back to the socket; we also commit the
1327 		 * binding of the address if in jail.
1328 		 *
1329 		 * If we already have a valid binding and we're not
1330 		 * requesting a destination address rewrite, use a fast path.
1331 		 */
1332 		if (inp->inp_laddr.s_addr == INADDR_ANY ||
1333 		    inp->inp_lport == 0 ||
1334 		    sin->sin_addr.s_addr == INADDR_ANY ||
1335 		    sin->sin_addr.s_addr == INADDR_BROADCAST) {
1336 			INP_HASH_LOCK_ASSERT(pcbinfo);
1337 			error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1338 			    &lport, &faddr.s_addr, &fport, NULL,
1339 			    td->td_ucred);
1340 			if (error)
1341 				goto release;
1342 
1343 			/*
1344 			 * XXXRW: Why not commit the port if the address is
1345 			 * !INADDR_ANY?
1346 			 */
1347 			/* Commit the local port if newly assigned. */
1348 			if (inp->inp_laddr.s_addr == INADDR_ANY &&
1349 			    inp->inp_lport == 0) {
1350 				INP_WLOCK_ASSERT(inp);
1351 				INP_HASH_WLOCK_ASSERT(pcbinfo);
1352 				/*
1353 				 * Remember addr if jailed, to prevent
1354 				 * rebinding.
1355 				 */
1356 				if (prison_flag(td->td_ucred, PR_IP4))
1357 					inp->inp_laddr = laddr;
1358 				inp->inp_lport = lport;
1359 				if (in_pcbinshash(inp) != 0) {
1360 					inp->inp_lport = 0;
1361 					error = EAGAIN;
1362 					goto release;
1363 				}
1364 				inp->inp_flags |= INP_ANONPORT;
1365 			}
1366 		} else {
1367 			faddr = sin->sin_addr;
1368 			fport = sin->sin_port;
1369 		}
1370 	} else {
1371 		INP_LOCK_ASSERT(inp);
1372 		faddr = inp->inp_faddr;
1373 		fport = inp->inp_fport;
1374 		if (faddr.s_addr == INADDR_ANY) {
1375 			error = ENOTCONN;
1376 			goto release;
1377 		}
1378 	}
1379 
1380 	/*
1381 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1382 	 * link-layer headers.  Immediate slide the data pointer back forward
1383 	 * since we won't use that space at this layer.
1384 	 */
1385 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1386 	if (m == NULL) {
1387 		error = ENOBUFS;
1388 		goto release;
1389 	}
1390 	m->m_data += max_linkhdr;
1391 	m->m_len -= max_linkhdr;
1392 	m->m_pkthdr.len -= max_linkhdr;
1393 
1394 	/*
1395 	 * Fill in mbuf with extended UDP header and addresses and length put
1396 	 * into network format.
1397 	 */
1398 	ui = mtod(m, struct udpiphdr *);
1399 	bzero(ui->ui_x1, sizeof(ui->ui_x1));	/* XXX still needed? */
1400 	ui->ui_v = IPVERSION << 4;
1401 	ui->ui_pr = pr;
1402 	ui->ui_src = laddr;
1403 	ui->ui_dst = faddr;
1404 	ui->ui_sport = lport;
1405 	ui->ui_dport = fport;
1406 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1407 	if (pr == IPPROTO_UDPLITE) {
1408 		struct udpcb *up;
1409 		uint16_t plen;
1410 
1411 		up = intoudpcb(inp);
1412 		cscov = up->u_txcslen;
1413 		plen = (u_short)len + sizeof(struct udphdr);
1414 		if (cscov >= plen)
1415 			cscov = 0;
1416 		ui->ui_len = htons(plen);
1417 		ui->ui_ulen = htons(cscov);
1418 		/*
1419 		 * For UDP-Lite, checksum coverage length of zero means
1420 		 * the entire UDPLite packet is covered by the checksum.
1421 		 */
1422 		cscov_partial = (cscov == 0) ? 0 : 1;
1423 	}
1424 
1425 	/*
1426 	 * Set the Don't Fragment bit in the IP header.
1427 	 */
1428 	if (inp->inp_flags & INP_DONTFRAG) {
1429 		struct ip *ip;
1430 
1431 		ip = (struct ip *)&ui->ui_i;
1432 		ip->ip_off |= htons(IP_DF);
1433 	}
1434 
1435 	ipflags = 0;
1436 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1437 		ipflags |= IP_ROUTETOIF;
1438 	if (inp->inp_socket->so_options & SO_BROADCAST)
1439 		ipflags |= IP_ALLOWBROADCAST;
1440 	if (inp->inp_flags & INP_ONESBCAST)
1441 		ipflags |= IP_SENDONES;
1442 
1443 #ifdef MAC
1444 	mac_inpcb_create_mbuf(inp, m);
1445 #endif
1446 
1447 	/*
1448 	 * Set up checksum and output datagram.
1449 	 */
1450 	ui->ui_sum = 0;
1451 	if (pr == IPPROTO_UDPLITE) {
1452 		if (inp->inp_flags & INP_ONESBCAST)
1453 			faddr.s_addr = INADDR_BROADCAST;
1454 		if (cscov_partial) {
1455 			if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1456 				ui->ui_sum = 0xffff;
1457 		} else {
1458 			if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1459 				ui->ui_sum = 0xffff;
1460 		}
1461 	} else if (V_udp_cksum) {
1462 		if (inp->inp_flags & INP_ONESBCAST)
1463 			faddr.s_addr = INADDR_BROADCAST;
1464 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1465 		    htons((u_short)len + sizeof(struct udphdr) + pr));
1466 		m->m_pkthdr.csum_flags = CSUM_UDP;
1467 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1468 	}
1469 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1470 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
1471 	((struct ip *)ui)->ip_tos = tos;		/* XXX */
1472 	UDPSTAT_INC(udps_opackets);
1473 
1474 	/*
1475 	 * Setup flowid / RSS information for outbound socket.
1476 	 *
1477 	 * Once the UDP code decides to set a flowid some other way,
1478 	 * this allows the flowid to be overridden by userland.
1479 	 */
1480 	if (flowtype != M_HASHTYPE_NONE) {
1481 		m->m_pkthdr.flowid = flowid;
1482 		M_HASHTYPE_SET(m, flowtype);
1483 #ifdef	RSS
1484 	} else {
1485 		uint32_t hash_val, hash_type;
1486 		/*
1487 		 * Calculate an appropriate RSS hash for UDP and
1488 		 * UDP Lite.
1489 		 *
1490 		 * The called function will take care of figuring out
1491 		 * whether a 2-tuple or 4-tuple hash is required based
1492 		 * on the currently configured scheme.
1493 		 *
1494 		 * Later later on connected socket values should be
1495 		 * cached in the inpcb and reused, rather than constantly
1496 		 * re-calculating it.
1497 		 *
1498 		 * UDP Lite is a different protocol number and will
1499 		 * likely end up being hashed as a 2-tuple until
1500 		 * RSS / NICs grow UDP Lite protocol awareness.
1501 		 */
1502 		if (rss_proto_software_hash_v4(faddr, laddr, fport, lport,
1503 		    pr, &hash_val, &hash_type) == 0) {
1504 			m->m_pkthdr.flowid = hash_val;
1505 			M_HASHTYPE_SET(m, hash_type);
1506 		}
1507 #endif
1508 	}
1509 
1510 #ifdef	RSS
1511 	/*
1512 	 * Don't override with the inp cached flowid value.
1513 	 *
1514 	 * Depending upon the kind of send being done, the inp
1515 	 * flowid/flowtype values may actually not be appropriate
1516 	 * for this particular socket send.
1517 	 *
1518 	 * We should either leave the flowid at zero (which is what is
1519 	 * currently done) or set it to some software generated
1520 	 * hash value based on the packet contents.
1521 	 */
1522 	ipflags |= IP_NODEFAULTFLOWID;
1523 #endif	/* RSS */
1524 
1525 	if (unlock_udbinfo == UH_WLOCKED)
1526 		INP_HASH_WUNLOCK(pcbinfo);
1527 	else if (unlock_udbinfo == UH_RLOCKED)
1528 		INP_HASH_RUNLOCK_ET(pcbinfo, et);
1529 	UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1530 	error = ip_output(m, inp->inp_options,
1531 	    (unlock_inp == UH_WLOCKED ? &inp->inp_route : NULL), ipflags,
1532 	    inp->inp_moptions, inp);
1533 	if (unlock_inp == UH_WLOCKED)
1534 		INP_WUNLOCK(inp);
1535 	else
1536 		INP_RUNLOCK(inp);
1537 	return (error);
1538 
1539 release:
1540 	if (unlock_udbinfo == UH_WLOCKED) {
1541 		KASSERT(unlock_inp == UH_WLOCKED,
1542 		    ("%s: excl udbinfo lock, shared inp lock", __func__));
1543 		INP_HASH_WUNLOCK(pcbinfo);
1544 		INP_WUNLOCK(inp);
1545 	} else if (unlock_udbinfo == UH_RLOCKED) {
1546 		KASSERT(unlock_inp == UH_RLOCKED,
1547 		    ("%s: shared udbinfo lock, excl inp lock", __func__));
1548 		INP_HASH_RUNLOCK_ET(pcbinfo, et);
1549 		INP_RUNLOCK(inp);
1550 	} else if (unlock_inp == UH_WLOCKED)
1551 		INP_WUNLOCK(inp);
1552 	else
1553 		INP_RUNLOCK(inp);
1554 	m_freem(m);
1555 	return (error);
1556 }
1557 
1558 static void
1559 udp_abort(struct socket *so)
1560 {
1561 	struct inpcb *inp;
1562 	struct inpcbinfo *pcbinfo;
1563 
1564 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1565 	inp = sotoinpcb(so);
1566 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1567 	INP_WLOCK(inp);
1568 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1569 		INP_HASH_WLOCK(pcbinfo);
1570 		in_pcbdisconnect(inp);
1571 		inp->inp_laddr.s_addr = INADDR_ANY;
1572 		INP_HASH_WUNLOCK(pcbinfo);
1573 		soisdisconnected(so);
1574 	}
1575 	INP_WUNLOCK(inp);
1576 }
1577 
1578 static int
1579 udp_attach(struct socket *so, int proto, struct thread *td)
1580 {
1581 	static uint32_t udp_flowid;
1582 	struct inpcb *inp;
1583 	struct inpcbinfo *pcbinfo;
1584 	int error;
1585 
1586 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1587 	inp = sotoinpcb(so);
1588 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1589 	error = soreserve(so, udp_sendspace, udp_recvspace);
1590 	if (error)
1591 		return (error);
1592 	INP_INFO_WLOCK(pcbinfo);
1593 	error = in_pcballoc(so, pcbinfo);
1594 	if (error) {
1595 		INP_INFO_WUNLOCK(pcbinfo);
1596 		return (error);
1597 	}
1598 
1599 	inp = sotoinpcb(so);
1600 	inp->inp_vflag |= INP_IPV4;
1601 	inp->inp_ip_ttl = V_ip_defttl;
1602 	inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1603 	inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1604 
1605 	error = udp_newudpcb(inp);
1606 	if (error) {
1607 		in_pcbdetach(inp);
1608 		in_pcbfree(inp);
1609 		INP_INFO_WUNLOCK(pcbinfo);
1610 		return (error);
1611 	}
1612 
1613 	INP_WUNLOCK(inp);
1614 	INP_INFO_WUNLOCK(pcbinfo);
1615 	return (0);
1616 }
1617 #endif /* INET */
1618 
1619 int
1620 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1621 {
1622 	struct inpcb *inp;
1623 	struct udpcb *up;
1624 
1625 	KASSERT(so->so_type == SOCK_DGRAM,
1626 	    ("udp_set_kernel_tunneling: !dgram"));
1627 	inp = sotoinpcb(so);
1628 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1629 	INP_WLOCK(inp);
1630 	up = intoudpcb(inp);
1631 	if ((up->u_tun_func != NULL) ||
1632 	    (up->u_icmp_func != NULL)) {
1633 		INP_WUNLOCK(inp);
1634 		return (EBUSY);
1635 	}
1636 	up->u_tun_func = f;
1637 	up->u_icmp_func = i;
1638 	up->u_tun_ctx = ctx;
1639 	INP_WUNLOCK(inp);
1640 	return (0);
1641 }
1642 
1643 #ifdef INET
1644 static int
1645 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1646 {
1647 	struct inpcb *inp;
1648 	struct inpcbinfo *pcbinfo;
1649 	int error;
1650 
1651 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1652 	inp = sotoinpcb(so);
1653 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1654 	INP_WLOCK(inp);
1655 	INP_HASH_WLOCK(pcbinfo);
1656 	error = in_pcbbind(inp, nam, td->td_ucred);
1657 	INP_HASH_WUNLOCK(pcbinfo);
1658 	INP_WUNLOCK(inp);
1659 	return (error);
1660 }
1661 
1662 static void
1663 udp_close(struct socket *so)
1664 {
1665 	struct inpcb *inp;
1666 	struct inpcbinfo *pcbinfo;
1667 
1668 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1669 	inp = sotoinpcb(so);
1670 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1671 	INP_WLOCK(inp);
1672 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1673 		INP_HASH_WLOCK(pcbinfo);
1674 		in_pcbdisconnect(inp);
1675 		inp->inp_laddr.s_addr = INADDR_ANY;
1676 		INP_HASH_WUNLOCK(pcbinfo);
1677 		soisdisconnected(so);
1678 	}
1679 	INP_WUNLOCK(inp);
1680 }
1681 
1682 static int
1683 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1684 {
1685 	struct inpcb *inp;
1686 	struct inpcbinfo *pcbinfo;
1687 	struct sockaddr_in *sin;
1688 	int error;
1689 
1690 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1691 	inp = sotoinpcb(so);
1692 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1693 	INP_WLOCK(inp);
1694 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1695 		INP_WUNLOCK(inp);
1696 		return (EISCONN);
1697 	}
1698 	sin = (struct sockaddr_in *)nam;
1699 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1700 	if (error != 0) {
1701 		INP_WUNLOCK(inp);
1702 		return (error);
1703 	}
1704 	INP_HASH_WLOCK(pcbinfo);
1705 	error = in_pcbconnect(inp, nam, td->td_ucred);
1706 	INP_HASH_WUNLOCK(pcbinfo);
1707 	if (error == 0)
1708 		soisconnected(so);
1709 	INP_WUNLOCK(inp);
1710 	return (error);
1711 }
1712 
1713 static void
1714 udp_detach(struct socket *so)
1715 {
1716 	struct inpcb *inp;
1717 	struct inpcbinfo *pcbinfo;
1718 	struct udpcb *up;
1719 
1720 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1721 	inp = sotoinpcb(so);
1722 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1723 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1724 	    ("udp_detach: not disconnected"));
1725 	INP_INFO_WLOCK(pcbinfo);
1726 	INP_WLOCK(inp);
1727 	up = intoudpcb(inp);
1728 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1729 	inp->inp_ppcb = NULL;
1730 	in_pcbdetach(inp);
1731 	in_pcbfree(inp);
1732 	INP_INFO_WUNLOCK(pcbinfo);
1733 	udp_discardcb(up);
1734 }
1735 
1736 static int
1737 udp_disconnect(struct socket *so)
1738 {
1739 	struct inpcb *inp;
1740 	struct inpcbinfo *pcbinfo;
1741 
1742 	pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1743 	inp = sotoinpcb(so);
1744 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1745 	INP_WLOCK(inp);
1746 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1747 		INP_WUNLOCK(inp);
1748 		return (ENOTCONN);
1749 	}
1750 	INP_HASH_WLOCK(pcbinfo);
1751 	in_pcbdisconnect(inp);
1752 	inp->inp_laddr.s_addr = INADDR_ANY;
1753 	INP_HASH_WUNLOCK(pcbinfo);
1754 	SOCK_LOCK(so);
1755 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1756 	SOCK_UNLOCK(so);
1757 	INP_WUNLOCK(inp);
1758 	return (0);
1759 }
1760 
1761 static int
1762 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1763     struct mbuf *control, struct thread *td)
1764 {
1765 	struct inpcb *inp;
1766 
1767 	inp = sotoinpcb(so);
1768 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1769 	return (udp_output(inp, m, addr, control, td));
1770 }
1771 #endif /* INET */
1772 
1773 int
1774 udp_shutdown(struct socket *so)
1775 {
1776 	struct inpcb *inp;
1777 
1778 	inp = sotoinpcb(so);
1779 	KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1780 	INP_WLOCK(inp);
1781 	socantsendmore(so);
1782 	INP_WUNLOCK(inp);
1783 	return (0);
1784 }
1785 
1786 #ifdef INET
1787 struct pr_usrreqs udp_usrreqs = {
1788 	.pru_abort =		udp_abort,
1789 	.pru_attach =		udp_attach,
1790 	.pru_bind =		udp_bind,
1791 	.pru_connect =		udp_connect,
1792 	.pru_control =		in_control,
1793 	.pru_detach =		udp_detach,
1794 	.pru_disconnect =	udp_disconnect,
1795 	.pru_peeraddr =		in_getpeeraddr,
1796 	.pru_send =		udp_send,
1797 	.pru_soreceive =	soreceive_dgram,
1798 	.pru_sosend =		sosend_dgram,
1799 	.pru_shutdown =		udp_shutdown,
1800 	.pru_sockaddr =		in_getsockaddr,
1801 	.pru_sosetlabel =	in_pcbsosetlabel,
1802 	.pru_close =		udp_close,
1803 };
1804 #endif /* INET */
1805