xref: /openbsd/sys/netinet/udp_usrreq.c (revision 3bef86f7)
1 /*	$OpenBSD: udp_usrreq.c,v 1.315 2024/01/21 01:17:20 bluhm Exp $	*/
2 /*	$NetBSD: udp_usrreq.c,v 1.28 1996/03/16 23:54:03 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1988, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
33  *
34  * NRL grants permission for redistribution and use in source and binary
35  * forms, with or without modification, of the software and documentation
36  * created at NRL provided that the following conditions are met:
37  *
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  * 3. All advertising materials mentioning features or use of this software
44  *    must display the following acknowledgements:
45  *	This product includes software developed by the University of
46  *	California, Berkeley and its contributors.
47  *	This product includes software developed at the Information
48  *	Technology Division, US Naval Research Laboratory.
49  * 4. Neither the name of the NRL nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
54  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
56  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
57  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
60  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
61  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
62  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  *
65  * The views and conclusions contained in the software and documentation
66  * are those of the authors and should not be interpreted as representing
67  * official policies, either expressed or implied, of the US Naval
68  * Research Laboratory (NRL).
69  */
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/mbuf.h>
74 #include <sys/protosw.h>
75 #include <sys/socket.h>
76 #include <sys/socketvar.h>
77 #include <sys/sysctl.h>
78 #include <sys/domain.h>
79 
80 #include <net/if.h>
81 #include <net/if_var.h>
82 #include <net/if_media.h>
83 #include <net/route.h>
84 
85 #include <netinet/in.h>
86 #include <netinet/in_var.h>
87 #include <netinet/ip.h>
88 #include <netinet/in_pcb.h>
89 #include <netinet/ip_var.h>
90 #include <netinet/ip_icmp.h>
91 #include <netinet/udp.h>
92 #include <netinet/udp_var.h>
93 
94 #ifdef IPSEC
95 #include <netinet/ip_ipsp.h>
96 #include <netinet/ip_esp.h>
97 #endif
98 
99 #ifdef INET6
100 #include <netinet6/in6_var.h>
101 #include <netinet6/ip6_var.h>
102 #include <netinet6/ip6protosw.h>
103 #endif /* INET6 */
104 
105 #include "pf.h"
106 #if NPF > 0
107 #include <net/pfvar.h>
108 #endif
109 
110 #ifdef PIPEX
111 #include <netinet/if_ether.h>
112 #include <net/pipex.h>
113 #endif
114 
115 /*
116  * UDP protocol implementation.
117  * Per RFC 768, August, 1980.
118  */
119 int	udpcksum = 1;
120 
121 u_int	udp_sendspace = 9216;		/* really max datagram size */
122 u_int	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
123 					/* 40 1K datagrams */
124 
125 const struct pr_usrreqs udp_usrreqs = {
126 	.pru_attach	= udp_attach,
127 	.pru_detach	= udp_detach,
128 	.pru_lock	= udp_lock,
129 	.pru_unlock	= udp_unlock,
130 	.pru_bind	= udp_bind,
131 	.pru_connect	= udp_connect,
132 	.pru_disconnect	= udp_disconnect,
133 	.pru_shutdown	= udp_shutdown,
134 	.pru_send	= udp_send,
135 	.pru_control	= in_control,
136 	.pru_sockaddr	= in_sockaddr,
137 	.pru_peeraddr	= in_peeraddr,
138 };
139 
140 #ifdef INET6
141 const struct pr_usrreqs udp6_usrreqs = {
142 	.pru_attach	= udp_attach,
143 	.pru_detach	= udp_detach,
144 	.pru_lock	= udp_lock,
145 	.pru_unlock	= udp_unlock,
146 	.pru_bind	= udp_bind,
147 	.pru_connect	= udp_connect,
148 	.pru_disconnect	= udp_disconnect,
149 	.pru_shutdown	= udp_shutdown,
150 	.pru_send	= udp_send,
151 	.pru_control	= in6_control,
152 	.pru_sockaddr	= in6_sockaddr,
153 	.pru_peeraddr	= in6_peeraddr,
154 };
155 #endif
156 
157 const struct sysctl_bounded_args udpctl_vars[] = {
158 	{ UDPCTL_CHECKSUM, &udpcksum, 0, 1 },
159 	{ UDPCTL_RECVSPACE, &udp_recvspace, 0, INT_MAX },
160 	{ UDPCTL_SENDSPACE, &udp_sendspace, 0, INT_MAX },
161 };
162 
163 struct	inpcbtable udbtable;
164 #ifdef INET6
165 struct	inpcbtable udb6table;
166 #endif
167 struct	cpumem *udpcounters;
168 
169 void	udp_sbappend(struct inpcb *, struct mbuf *, struct ip *,
170 	    struct ip6_hdr *, int, struct udphdr *, struct sockaddr *,
171 	    u_int32_t);
172 int	udp_output(struct inpcb *, struct mbuf *, struct mbuf *, struct mbuf *);
173 void	udp_notify(struct inpcb *, int);
174 int	udp_sysctl_udpstat(void *, size_t *, void *);
175 
176 #ifndef	UDB_INITIAL_HASH_SIZE
177 #define	UDB_INITIAL_HASH_SIZE	128
178 #endif
179 
180 void
181 udp_init(void)
182 {
183 	udpcounters = counters_alloc(udps_ncounters);
184 	in_pcbinit(&udbtable, UDB_INITIAL_HASH_SIZE);
185 #ifdef INET6
186 	in_pcbinit(&udb6table, UDB_INITIAL_HASH_SIZE);
187 #endif
188 }
189 
190 int
191 udp_input(struct mbuf **mp, int *offp, int proto, int af)
192 {
193 	struct mbuf *m = *mp;
194 	int iphlen = *offp;
195 	struct ip *ip = NULL;
196 	struct udphdr *uh;
197 	struct inpcb *inp = NULL;
198 	struct ip save_ip;
199 	int len;
200 	u_int16_t savesum;
201 	union {
202 		struct sockaddr sa;
203 		struct sockaddr_in sin;
204 #ifdef INET6
205 		struct sockaddr_in6 sin6;
206 #endif /* INET6 */
207 	} srcsa, dstsa;
208 	struct ip6_hdr *ip6 = NULL;
209 	u_int32_t ipsecflowinfo = 0;
210 
211 	udpstat_inc(udps_ipackets);
212 
213 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
214 	if (!uh) {
215 		udpstat_inc(udps_hdrops);
216 		return IPPROTO_DONE;
217 	}
218 
219 	/* Check for illegal destination port 0 */
220 	if (uh->uh_dport == 0) {
221 		udpstat_inc(udps_noport);
222 		goto bad;
223 	}
224 
225 	/*
226 	 * Make mbuf data length reflect UDP length.
227 	 * If not enough data to reflect UDP length, drop.
228 	 */
229 	len = ntohs((u_int16_t)uh->uh_ulen);
230 	switch (af) {
231 	case AF_INET:
232 		if (m->m_pkthdr.len - iphlen != len) {
233 			if (len > (m->m_pkthdr.len - iphlen) ||
234 			    len < sizeof(struct udphdr)) {
235 				udpstat_inc(udps_badlen);
236 				goto bad;
237 			}
238 			m_adj(m, len - (m->m_pkthdr.len - iphlen));
239 		}
240 		ip = mtod(m, struct ip *);
241 		/*
242 		 * Save a copy of the IP header in case we want restore it
243 		 * for sending an ICMP error message in response.
244 		 */
245 		save_ip = *ip;
246 		break;
247 #ifdef INET6
248 	case AF_INET6:
249 		/* jumbograms */
250 		if (len == 0 && m->m_pkthdr.len - iphlen > 0xffff)
251 			len = m->m_pkthdr.len - iphlen;
252 		if (len != m->m_pkthdr.len - iphlen) {
253 			udpstat_inc(udps_badlen);
254 			goto bad;
255 		}
256 		ip6 = mtod(m, struct ip6_hdr *);
257 		break;
258 #endif /* INET6 */
259 	default:
260 		unhandled_af(af);
261 	}
262 
263 	/*
264 	 * Checksum extended UDP header and data.
265 	 * from W.R.Stevens: check incoming udp cksums even if
266 	 *	udpcksum is not set.
267 	 */
268 	savesum = uh->uh_sum;
269 	if (uh->uh_sum == 0) {
270 		udpstat_inc(udps_nosum);
271 #ifdef INET6
272 		/*
273 		 * In IPv6, the UDP checksum is ALWAYS used.
274 		 */
275 		if (ip6)
276 			goto bad;
277 #endif /* INET6 */
278 	} else {
279 		if ((m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_OK) == 0) {
280 			if (m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_BAD) {
281 				udpstat_inc(udps_badsum);
282 				goto bad;
283 			}
284 			udpstat_inc(udps_inswcsum);
285 
286 			if (ip)
287 				uh->uh_sum = in4_cksum(m, IPPROTO_UDP,
288 				    iphlen, len);
289 #ifdef INET6
290 			else if (ip6)
291 				uh->uh_sum = in6_cksum(m, IPPROTO_UDP,
292 				    iphlen, len);
293 #endif /* INET6 */
294 			if (uh->uh_sum != 0) {
295 				udpstat_inc(udps_badsum);
296 				goto bad;
297 			}
298 		}
299 	}
300 
301 #ifdef IPSEC
302 	if (udpencap_enable && udpencap_port && esp_enable &&
303 #if NPF > 0
304 	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
305 #endif
306 	    uh->uh_dport == htons(udpencap_port)) {
307 		u_int32_t spi;
308 		int skip = iphlen + sizeof(struct udphdr);
309 
310 		if (m->m_pkthdr.len - skip < sizeof(u_int32_t)) {
311 			/* packet too short */
312 			m_freem(m);
313 			return IPPROTO_DONE;
314 		}
315 		m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
316 		/*
317 		 * decapsulate if the SPI is not zero, otherwise pass
318 		 * to userland
319 		 */
320 		if (spi != 0) {
321 			int protoff;
322 
323 			if ((m = *mp = m_pullup(m, skip)) == NULL) {
324 				udpstat_inc(udps_hdrops);
325 				return IPPROTO_DONE;
326 			}
327 
328 			/* remove the UDP header */
329 			bcopy(mtod(m, u_char *),
330 			    mtod(m, u_char *) + sizeof(struct udphdr), iphlen);
331 			m_adj(m, sizeof(struct udphdr));
332 			skip -= sizeof(struct udphdr);
333 
334 			espstat_inc(esps_udpencin);
335 			protoff = af == AF_INET ? offsetof(struct ip, ip_p) :
336 			    offsetof(struct ip6_hdr, ip6_nxt);
337 			return ipsec_common_input(mp, skip, protoff,
338 			    af, IPPROTO_ESP, 1);
339 		}
340 	}
341 #endif /* IPSEC */
342 
343 	switch (af) {
344 	case AF_INET:
345 		bzero(&srcsa, sizeof(struct sockaddr_in));
346 		srcsa.sin.sin_len = sizeof(struct sockaddr_in);
347 		srcsa.sin.sin_family = AF_INET;
348 		srcsa.sin.sin_port = uh->uh_sport;
349 		srcsa.sin.sin_addr = ip->ip_src;
350 
351 		bzero(&dstsa, sizeof(struct sockaddr_in));
352 		dstsa.sin.sin_len = sizeof(struct sockaddr_in);
353 		dstsa.sin.sin_family = AF_INET;
354 		dstsa.sin.sin_port = uh->uh_dport;
355 		dstsa.sin.sin_addr = ip->ip_dst;
356 		break;
357 #ifdef INET6
358 	case AF_INET6:
359 		bzero(&srcsa, sizeof(struct sockaddr_in6));
360 		srcsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
361 		srcsa.sin6.sin6_family = AF_INET6;
362 		srcsa.sin6.sin6_port = uh->uh_sport;
363 #if 0 /*XXX inbound flowinfo */
364 		srcsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
365 #endif
366 		/* KAME hack: recover scopeid */
367 		in6_recoverscope(&srcsa.sin6, &ip6->ip6_src);
368 
369 		bzero(&dstsa, sizeof(struct sockaddr_in6));
370 		dstsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
371 		dstsa.sin6.sin6_family = AF_INET6;
372 		dstsa.sin6.sin6_port = uh->uh_dport;
373 #if 0 /*XXX inbound flowinfo */
374 		dstsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
375 #endif
376 		/* KAME hack: recover scopeid */
377 		in6_recoverscope(&dstsa.sin6, &ip6->ip6_dst);
378 		break;
379 #endif /* INET6 */
380 	}
381 
382 	if (m->m_flags & (M_BCAST|M_MCAST)) {
383 		SIMPLEQ_HEAD(, inpcb) inpcblist;
384 		struct inpcbtable *table;
385 
386 		/*
387 		 * Deliver a multicast or broadcast datagram to *all* sockets
388 		 * for which the local and remote addresses and ports match
389 		 * those of the incoming datagram.  This allows more than
390 		 * one process to receive multi/broadcasts on the same port.
391 		 * (This really ought to be done for unicast datagrams as
392 		 * well, but that would cause problems with existing
393 		 * applications that open both address-specific sockets and
394 		 * a wildcard socket listening to the same port -- they would
395 		 * end up receiving duplicates of every unicast datagram.
396 		 * Those applications open the multiple sockets to overcome an
397 		 * inadequacy of the UDP socket interface, but for backwards
398 		 * compatibility we avoid the problem here rather than
399 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
400 		 */
401 
402 		/*
403 		 * Locate pcb(s) for datagram.
404 		 * (Algorithm copied from raw_intr().)
405 		 */
406 		SIMPLEQ_INIT(&inpcblist);
407 #ifdef INET6
408 		if (ip6)
409 			table = &udb6table;
410 		else
411 #endif
412 			table = &udbtable;
413 
414 		rw_enter_write(&table->inpt_notify);
415 		mtx_enter(&table->inpt_mtx);
416 		TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
417 			if (ip6)
418 				KASSERT(ISSET(inp->inp_flags, INP_IPV6));
419 			else
420 				KASSERT(!ISSET(inp->inp_flags, INP_IPV6));
421 
422 			if (inp->inp_socket->so_rcv.sb_state & SS_CANTRCVMORE)
423 				continue;
424 			if (rtable_l2(inp->inp_rtableid) !=
425 			    rtable_l2(m->m_pkthdr.ph_rtableid))
426 				continue;
427 			if (inp->inp_lport != uh->uh_dport)
428 				continue;
429 #ifdef INET6
430 			if (ip6) {
431 				if (inp->inp_ip6_minhlim &&
432 				    inp->inp_ip6_minhlim > ip6->ip6_hlim)
433 					continue;
434 				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6))
435 					if (!IN6_ARE_ADDR_EQUAL(
436 					    &inp->inp_laddr6, &ip6->ip6_dst))
437 						continue;
438 			} else
439 #endif /* INET6 */
440 			{
441 				if (inp->inp_ip_minttl &&
442 				    inp->inp_ip_minttl > ip->ip_ttl)
443 					continue;
444 
445 				if (inp->inp_laddr.s_addr != INADDR_ANY) {
446 					if (inp->inp_laddr.s_addr !=
447 					    ip->ip_dst.s_addr)
448 						continue;
449 				}
450 			}
451 #ifdef INET6
452 			if (ip6) {
453 				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
454 					if (!IN6_ARE_ADDR_EQUAL(
455 					    &inp->inp_faddr6, &ip6->ip6_src) ||
456 					    inp->inp_fport != uh->uh_sport)
457 						continue;
458 			} else
459 #endif /* INET6 */
460 			if (inp->inp_faddr.s_addr != INADDR_ANY) {
461 				if (inp->inp_faddr.s_addr !=
462 				    ip->ip_src.s_addr ||
463 				    inp->inp_fport != uh->uh_sport)
464 					continue;
465 			}
466 
467 			in_pcbref(inp);
468 			SIMPLEQ_INSERT_TAIL(&inpcblist, inp, inp_notify);
469 
470 			/*
471 			 * Don't look for additional matches if this one does
472 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
473 			 * socket options set.  This heuristic avoids searching
474 			 * through all pcbs in the common case of a non-shared
475 			 * port.  It assumes that an application will never
476 			 * clear these options after setting them.
477 			 */
478 			if ((inp->inp_socket->so_options & (SO_REUSEPORT |
479 			    SO_REUSEADDR)) == 0)
480 				break;
481 		}
482 		mtx_leave(&table->inpt_mtx);
483 
484 		if (SIMPLEQ_EMPTY(&inpcblist)) {
485 			rw_exit_write(&table->inpt_notify);
486 
487 			/*
488 			 * No matching pcb found; discard datagram.
489 			 * (No need to send an ICMP Port Unreachable
490 			 * for a broadcast or multicast datgram.)
491 			 */
492 			udpstat_inc(udps_noportbcast);
493 			goto bad;
494 		}
495 
496 		while ((inp = SIMPLEQ_FIRST(&inpcblist)) != NULL) {
497 			struct mbuf *n;
498 
499 			SIMPLEQ_REMOVE_HEAD(&inpcblist, inp_notify);
500 			if (SIMPLEQ_EMPTY(&inpcblist))
501 				n = m;
502 			else
503 				n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
504 			if (n != NULL) {
505 				udp_sbappend(inp, n, ip, ip6, iphlen, uh,
506 				    &srcsa.sa, 0);
507 			}
508 			in_pcbunref(inp);
509 		}
510 		rw_exit_write(&table->inpt_notify);
511 
512 		return IPPROTO_DONE;
513 	}
514 	/*
515 	 * Locate pcb for datagram.
516 	 */
517 #if NPF > 0
518 	inp = pf_inp_lookup(m);
519 #endif
520 	if (inp == NULL) {
521 #ifdef INET6
522 		if (ip6) {
523 			inp = in6_pcblookup(&udb6table, &ip6->ip6_src,
524 			    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
525 			    m->m_pkthdr.ph_rtableid);
526 		} else
527 #endif /* INET6 */
528 		{
529 			inp = in_pcblookup(&udbtable, ip->ip_src,
530 			    uh->uh_sport, ip->ip_dst, uh->uh_dport,
531 			    m->m_pkthdr.ph_rtableid);
532 		}
533 	}
534 	if (inp == NULL) {
535 		udpstat_inc(udps_pcbhashmiss);
536 #ifdef INET6
537 		if (ip6) {
538 			inp = in6_pcblookup_listen(&udb6table, &ip6->ip6_dst,
539 			    uh->uh_dport, m, m->m_pkthdr.ph_rtableid);
540 		} else
541 #endif /* INET6 */
542 		{
543 			inp = in_pcblookup_listen(&udbtable, ip->ip_dst,
544 			    uh->uh_dport, m, m->m_pkthdr.ph_rtableid);
545 		}
546 	}
547 
548 #ifdef IPSEC
549 	if (ipsec_in_use) {
550 		struct m_tag *mtag;
551 		struct tdb_ident *tdbi;
552 		struct tdb *tdb;
553 		int error;
554 
555 		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
556 		if (mtag != NULL) {
557 			tdbi = (struct tdb_ident *)(mtag + 1);
558 			tdb = gettdb(tdbi->rdomain, tdbi->spi,
559 			    &tdbi->dst, tdbi->proto);
560 		} else
561 			tdb = NULL;
562 		error = ipsp_spd_lookup(m, af, iphlen, IPSP_DIRECTION_IN,
563 		    tdb, inp ? inp->inp_seclevel : NULL, NULL, NULL);
564 		if (error) {
565 			udpstat_inc(udps_nosec);
566 			tdb_unref(tdb);
567 			goto bad;
568 		}
569 		/* create ipsec options, id is not modified after creation */
570 		if (tdb && tdb->tdb_ids)
571 			ipsecflowinfo = tdb->tdb_ids->id_flow;
572 		tdb_unref(tdb);
573 	}
574 #endif /*IPSEC */
575 
576 	if (inp == NULL) {
577 		udpstat_inc(udps_noport);
578 		if (m->m_flags & (M_BCAST | M_MCAST)) {
579 			udpstat_inc(udps_noportbcast);
580 			goto bad;
581 		}
582 #ifdef INET6
583 		if (ip6) {
584 			uh->uh_sum = savesum;
585 			icmp6_error(m, ICMP6_DST_UNREACH,
586 			    ICMP6_DST_UNREACH_NOPORT,0);
587 		} else
588 #endif /* INET6 */
589 		{
590 			*ip = save_ip;
591 			uh->uh_sum = savesum;
592 			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT,
593 			    0, 0);
594 		}
595 		return IPPROTO_DONE;
596 	}
597 
598 	KASSERT(sotoinpcb(inp->inp_socket) == inp);
599 	soassertlocked(inp->inp_socket);
600 
601 #ifdef INET6
602 	if (ip6 && inp->inp_ip6_minhlim &&
603 	    inp->inp_ip6_minhlim > ip6->ip6_hlim) {
604 		goto bad;
605 	} else
606 #endif
607 	if (ip && inp->inp_ip_minttl &&
608 	    inp->inp_ip_minttl > ip->ip_ttl) {
609 		goto bad;
610 	}
611 
612 #if NPF > 0
613 	if (inp->inp_socket->so_state & SS_ISCONNECTED)
614 		pf_inp_link(m, inp);
615 #endif
616 
617 #ifdef PIPEX
618 	if (pipex_enable && inp->inp_pipex) {
619 		struct pipex_session *session;
620 		int off = iphlen + sizeof(struct udphdr);
621 
622 		if ((session = pipex_l2tp_lookup_session(m, off)) != NULL) {
623 			m = *mp = pipex_l2tp_input(m, off, session,
624 			    ipsecflowinfo);
625 			pipex_rele_session(session);
626 			if (m == NULL) {
627 				in_pcbunref(inp);
628 				return IPPROTO_DONE;
629 			}
630 		}
631 	}
632 #endif
633 
634 	udp_sbappend(inp, m, ip, ip6, iphlen, uh, &srcsa.sa, ipsecflowinfo);
635 	in_pcbunref(inp);
636 	return IPPROTO_DONE;
637 bad:
638 	m_freem(m);
639 	in_pcbunref(inp);
640 	return IPPROTO_DONE;
641 }
642 
643 void
644 udp_sbappend(struct inpcb *inp, struct mbuf *m, struct ip *ip,
645     struct ip6_hdr *ip6, int hlen, struct udphdr *uh,
646     struct sockaddr *srcaddr, u_int32_t ipsecflowinfo)
647 {
648 	struct socket *so = inp->inp_socket;
649 	struct mbuf *opts = NULL;
650 
651 	hlen += sizeof(*uh);
652 
653 	if (inp->inp_upcall != NULL) {
654 		m = (*inp->inp_upcall)(inp->inp_upcall_arg, m,
655 		    ip, ip6, uh, hlen);
656 		if (m == NULL)
657 			return;
658 	}
659 
660 #ifdef INET6
661 	if (ip6 && (inp->inp_flags & IN6P_CONTROLOPTS ||
662 	    so->so_options & SO_TIMESTAMP))
663 		ip6_savecontrol(inp, m, &opts);
664 #endif /* INET6 */
665 	if (ip && (inp->inp_flags & INP_CONTROLOPTS ||
666 	    so->so_options & SO_TIMESTAMP))
667 		ip_savecontrol(inp, &opts, ip, m);
668 #ifdef INET6
669 	if (ip6 && (inp->inp_flags & IN6P_RECVDSTPORT)) {
670 		struct mbuf **mp = &opts;
671 
672 		while (*mp)
673 			mp = &(*mp)->m_next;
674 		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
675 		    IPV6_RECVDSTPORT, IPPROTO_IPV6);
676 	}
677 #endif /* INET6 */
678 	if (ip && (inp->inp_flags & INP_RECVDSTPORT)) {
679 		struct mbuf **mp = &opts;
680 
681 		while (*mp)
682 			mp = &(*mp)->m_next;
683 		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
684 		    IP_RECVDSTPORT, IPPROTO_IP);
685 	}
686 #ifdef IPSEC
687 	if (ipsecflowinfo && (inp->inp_flags & INP_IPSECFLOWINFO)) {
688 		struct mbuf **mp = &opts;
689 
690 		while (*mp)
691 			mp = &(*mp)->m_next;
692 		*mp = sbcreatecontrol((caddr_t)&ipsecflowinfo,
693 		    sizeof(u_int32_t), IP_IPSECFLOWINFO, IPPROTO_IP);
694 	}
695 #endif
696 	m_adj(m, hlen);
697 
698 	mtx_enter(&inp->inp_mtx);
699 	if (sbappendaddr(so, &so->so_rcv, srcaddr, m, opts) == 0) {
700 		mtx_leave(&inp->inp_mtx);
701 		udpstat_inc(udps_fullsock);
702 		m_freem(m);
703 		m_freem(opts);
704 		return;
705 	}
706 	mtx_leave(&inp->inp_mtx);
707 
708 	sorwakeup(so);
709 }
710 
711 /*
712  * Notify a udp user of an asynchronous error;
713  * just wake up so that he can collect error status.
714  */
715 void
716 udp_notify(struct inpcb *inp, int errno)
717 {
718 	inp->inp_socket->so_error = errno;
719 	sorwakeup(inp->inp_socket);
720 	sowwakeup(inp->inp_socket);
721 }
722 
723 #ifdef INET6
724 void
725 udp6_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *d)
726 {
727 	struct udphdr uh;
728 	struct sockaddr_in6 sa6;
729 	struct ip6_hdr *ip6;
730 	struct mbuf *m;
731 	int off;
732 	void *cmdarg;
733 	struct ip6ctlparam *ip6cp = NULL;
734 	struct udp_portonly {
735 		u_int16_t uh_sport;
736 		u_int16_t uh_dport;
737 	} *uhp;
738 	struct inpcb *inp;
739 	void (*notify)(struct inpcb *, int) = udp_notify;
740 
741 	if (sa == NULL)
742 		return;
743 	if (sa->sa_family != AF_INET6 ||
744 	    sa->sa_len != sizeof(struct sockaddr_in6))
745 		return;
746 
747 	if ((unsigned)cmd >= PRC_NCMDS)
748 		return;
749 	if (PRC_IS_REDIRECT(cmd))
750 		notify = in_rtchange, d = NULL;
751 	else if (cmd == PRC_HOSTDEAD)
752 		d = NULL;
753 	else if (cmd == PRC_MSGSIZE)
754 		; /* special code is present, see below */
755 	else if (inet6ctlerrmap[cmd] == 0)
756 		return;
757 
758 	/* if the parameter is from icmp6, decode it. */
759 	if (d != NULL) {
760 		ip6cp = (struct ip6ctlparam *)d;
761 		m = ip6cp->ip6c_m;
762 		ip6 = ip6cp->ip6c_ip6;
763 		off = ip6cp->ip6c_off;
764 		cmdarg = ip6cp->ip6c_cmdarg;
765 	} else {
766 		m = NULL;
767 		ip6 = NULL;
768 		cmdarg = NULL;
769 		/* XXX: translate addresses into internal form */
770 		sa6 = *satosin6(sa);
771 		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL, NULL)) {
772 			/* should be impossible */
773 			return;
774 		}
775 	}
776 
777 	if (ip6cp && ip6cp->ip6c_finaldst) {
778 		bzero(&sa6, sizeof(sa6));
779 		sa6.sin6_family = AF_INET6;
780 		sa6.sin6_len = sizeof(sa6);
781 		sa6.sin6_addr = *ip6cp->ip6c_finaldst;
782 		/* XXX: assuming M is valid in this case */
783 		sa6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
784 		    ip6cp->ip6c_finaldst);
785 		if (in6_embedscope(ip6cp->ip6c_finaldst, &sa6, NULL, NULL)) {
786 			/* should be impossible */
787 			return;
788 		}
789 	} else {
790 		/* XXX: translate addresses into internal form */
791 		sa6 = *satosin6(sa);
792 		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL, NULL)) {
793 			/* should be impossible */
794 			return;
795 		}
796 	}
797 
798 	if (ip6) {
799 		/*
800 		 * XXX: We assume that when IPV6 is non NULL,
801 		 * M and OFF are valid.
802 		 */
803 		struct sockaddr_in6 sa6_src;
804 
805 		/* check if we can safely examine src and dst ports */
806 		if (m->m_pkthdr.len < off + sizeof(*uhp))
807 			return;
808 
809 		bzero(&uh, sizeof(uh));
810 		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
811 
812 		bzero(&sa6_src, sizeof(sa6_src));
813 		sa6_src.sin6_family = AF_INET6;
814 		sa6_src.sin6_len = sizeof(sa6_src);
815 		sa6_src.sin6_addr = ip6->ip6_src;
816 		sa6_src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
817 		    &ip6->ip6_src);
818 		if (in6_embedscope(&sa6_src.sin6_addr, &sa6_src, NULL, NULL)) {
819 			/* should be impossible */
820 			return;
821 		}
822 
823 		if (cmd == PRC_MSGSIZE) {
824 			/*
825 			 * Check to see if we have a valid UDP socket
826 			 * corresponding to the address in the ICMPv6 message
827 			 * payload.
828 			 */
829 			inp = in6_pcblookup(&udb6table, &sa6.sin6_addr,
830 			    uh.uh_dport, &sa6_src.sin6_addr, uh.uh_sport,
831 			    rdomain);
832 #if 0
833 			/*
834 			 * As the use of sendto(2) is fairly popular,
835 			 * we may want to allow non-connected pcb too.
836 			 * But it could be too weak against attacks...
837 			 * We should at least check if the local address (= s)
838 			 * is really ours.
839 			 */
840 			if (inp == NULL) {
841 				inp = in6_pcblookup_listen(&udb6table,
842 				    &sa6_src.sin6_addr, uh.uh_sport, NULL,
843 				    rdomain))
844 			}
845 #endif
846 
847 			/*
848 			 * Depending on the value of "valid" and routing table
849 			 * size (mtudisc_{hi,lo}wat), we will:
850 			 * - recalculate the new MTU and create the
851 			 *   corresponding routing entry, or
852 			 * - ignore the MTU change notification.
853 			 */
854 			icmp6_mtudisc_update((struct ip6ctlparam *)d,
855 			    inp != NULL);
856 			in_pcbunref(inp);
857 
858 			/*
859 			 * regardless of if we called icmp6_mtudisc_update(),
860 			 * we need to call in6_pcbnotify(), to notify path
861 			 * MTU change to the userland (2292bis-02), because
862 			 * some unconnected sockets may share the same
863 			 * destination and want to know the path MTU.
864 			 */
865 		}
866 
867 		in6_pcbnotify(&udb6table, &sa6, uh.uh_dport,
868 		    &sa6_src, uh.uh_sport, rdomain, cmd, cmdarg, notify);
869 	} else {
870 		in6_pcbnotify(&udb6table, &sa6, 0,
871 		    &sa6_any, 0, rdomain, cmd, cmdarg, notify);
872 	}
873 }
874 #endif
875 
876 void
877 udp_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v)
878 {
879 	struct ip *ip = v;
880 	struct udphdr *uhp;
881 	struct in_addr faddr;
882 	struct inpcb *inp;
883 	void (*notify)(struct inpcb *, int) = udp_notify;
884 	int errno;
885 
886 	if (sa == NULL)
887 		return;
888 	if (sa->sa_family != AF_INET ||
889 	    sa->sa_len != sizeof(struct sockaddr_in))
890 		return;
891 	faddr = satosin(sa)->sin_addr;
892 	if (faddr.s_addr == INADDR_ANY)
893 		return;
894 
895 	if ((unsigned)cmd >= PRC_NCMDS)
896 		return;
897 	errno = inetctlerrmap[cmd];
898 	if (PRC_IS_REDIRECT(cmd))
899 		notify = in_rtchange, ip = 0;
900 	else if (cmd == PRC_HOSTDEAD)
901 		ip = 0;
902 	else if (errno == 0)
903 		return;
904 	if (ip) {
905 		uhp = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
906 
907 #ifdef IPSEC
908 		/* PMTU discovery for udpencap */
909 		if (cmd == PRC_MSGSIZE && ip_mtudisc && udpencap_enable &&
910 		    udpencap_port && uhp->uh_sport == htons(udpencap_port)) {
911 			udpencap_ctlinput(cmd, sa, rdomain, v);
912 			return;
913 		}
914 #endif
915 		inp = in_pcblookup(&udbtable,
916 		    ip->ip_dst, uhp->uh_dport, ip->ip_src, uhp->uh_sport,
917 		    rdomain);
918 		if (inp != NULL)
919 			notify(inp, errno);
920 		in_pcbunref(inp);
921 	} else
922 		in_pcbnotifyall(&udbtable, sa, rdomain, errno, notify);
923 }
924 
925 int
926 udp_output(struct inpcb *inp, struct mbuf *m, struct mbuf *addr,
927     struct mbuf *control)
928 {
929 	struct sockaddr_in *sin = NULL;
930 	struct udpiphdr *ui;
931 	u_int32_t ipsecflowinfo = 0;
932 	struct sockaddr_in src_sin;
933 	int len = m->m_pkthdr.len;
934 	struct in_addr laddr;
935 	int error = 0;
936 
937 #ifdef INET6
938 	if (ISSET(inp->inp_flags, INP_IPV6))
939 		return (udp6_output(inp, m, addr, control));
940 #endif
941 
942 	/*
943 	 * Compute the packet length of the IP header, and
944 	 * punt if the length looks bogus.
945 	 */
946 	if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) {
947 		error = EMSGSIZE;
948 		goto release;
949 	}
950 
951 	memset(&src_sin, 0, sizeof(src_sin));
952 
953 	if (control) {
954 		u_int clen;
955 		struct cmsghdr *cm;
956 		caddr_t cmsgs;
957 
958 		/*
959 		 * XXX: Currently, we assume all the optional information is
960 		 * stored in a single mbuf.
961 		 */
962 		if (control->m_next) {
963 			error = EINVAL;
964 			goto release;
965 		}
966 
967 		clen = control->m_len;
968 		cmsgs = mtod(control, caddr_t);
969 		do {
970 			if (clen < CMSG_LEN(0)) {
971 				error = EINVAL;
972 				goto release;
973 			}
974 			cm = (struct cmsghdr *)cmsgs;
975 			if (cm->cmsg_len < CMSG_LEN(0) ||
976 			    CMSG_ALIGN(cm->cmsg_len) > clen) {
977 				error = EINVAL;
978 				goto release;
979 			}
980 #ifdef IPSEC
981 			if ((inp->inp_flags & INP_IPSECFLOWINFO) != 0 &&
982 			    cm->cmsg_len == CMSG_LEN(sizeof(ipsecflowinfo)) &&
983 			    cm->cmsg_level == IPPROTO_IP &&
984 			    cm->cmsg_type == IP_IPSECFLOWINFO) {
985 				ipsecflowinfo = *(u_int32_t *)CMSG_DATA(cm);
986 			} else
987 #endif
988 			if (cm->cmsg_len == CMSG_LEN(sizeof(struct in_addr)) &&
989 			    cm->cmsg_level == IPPROTO_IP &&
990 			    cm->cmsg_type == IP_SENDSRCADDR) {
991 				memcpy(&src_sin.sin_addr, CMSG_DATA(cm),
992 				    sizeof(struct in_addr));
993 				src_sin.sin_family = AF_INET;
994 				src_sin.sin_len = sizeof(src_sin);
995 				/* no check on reuse when sin->sin_port == 0 */
996 				if ((error = in_pcbaddrisavail(inp, &src_sin,
997 				    0, curproc)))
998 					goto release;
999 			}
1000 			clen -= CMSG_ALIGN(cm->cmsg_len);
1001 			cmsgs += CMSG_ALIGN(cm->cmsg_len);
1002 		} while (clen);
1003 	}
1004 
1005 	if (addr) {
1006 		if ((error = in_nam2sin(addr, &sin)))
1007 			goto release;
1008 		if (sin->sin_port == 0) {
1009 			error = EADDRNOTAVAIL;
1010 			goto release;
1011 		}
1012 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1013 			error = EISCONN;
1014 			goto release;
1015 		}
1016 		error = in_pcbselsrc(&laddr, sin, inp);
1017 		if (error)
1018 			goto release;
1019 
1020 		if (inp->inp_lport == 0) {
1021 			error = in_pcbbind(inp, NULL, curproc);
1022 			if (error)
1023 				goto release;
1024 		}
1025 
1026 		if (src_sin.sin_len > 0 &&
1027 		    src_sin.sin_addr.s_addr != INADDR_ANY &&
1028 		    src_sin.sin_addr.s_addr != inp->inp_laddr.s_addr) {
1029 			src_sin.sin_port = inp->inp_lport;
1030 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
1031 			    (error =
1032 			    in_pcbaddrisavail(inp, &src_sin, 0, curproc)))
1033 				goto release;
1034 			laddr = src_sin.sin_addr;
1035 		}
1036 	} else {
1037 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
1038 			error = ENOTCONN;
1039 			goto release;
1040 		}
1041 		laddr = inp->inp_laddr;
1042 	}
1043 
1044 	/*
1045 	 * Calculate data length and get a mbuf
1046 	 * for UDP and IP headers.
1047 	 */
1048 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
1049 	if (m == NULL) {
1050 		error = ENOBUFS;
1051 		goto bail;
1052 	}
1053 
1054 	/*
1055 	 * Fill in mbuf with extended UDP header
1056 	 * and addresses and length put into network format.
1057 	 */
1058 	ui = mtod(m, struct udpiphdr *);
1059 	bzero(ui->ui_x1, sizeof ui->ui_x1);
1060 	ui->ui_pr = IPPROTO_UDP;
1061 	ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr));
1062 	ui->ui_src = laddr;
1063 	ui->ui_dst = sin ? sin->sin_addr : inp->inp_faddr;
1064 	ui->ui_sport = inp->inp_lport;
1065 	ui->ui_dport = sin ? sin->sin_port : inp->inp_fport;
1066 	ui->ui_ulen = ui->ui_len;
1067 	((struct ip *)ui)->ip_len = htons(sizeof (struct udpiphdr) + len);
1068 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;
1069 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;
1070 	if (udpcksum)
1071 		m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
1072 
1073 	udpstat_inc(udps_opackets);
1074 
1075 	/* force routing table */
1076 	m->m_pkthdr.ph_rtableid = inp->inp_rtableid;
1077 
1078 #if NPF > 0
1079 	if (inp->inp_socket->so_state & SS_ISCONNECTED)
1080 		pf_mbuf_link_inpcb(m, inp);
1081 #endif
1082 
1083 	error = ip_output(m, inp->inp_options, &inp->inp_route,
1084 	    (inp->inp_socket->so_options & SO_BROADCAST), inp->inp_moptions,
1085 	    inp->inp_seclevel, ipsecflowinfo);
1086 
1087 bail:
1088 	m_freem(control);
1089 	return (error);
1090 
1091 release:
1092 	m_freem(m);
1093 	goto bail;
1094 }
1095 
1096 int
1097 udp_attach(struct socket *so, int proto, int wait)
1098 {
1099 	struct inpcbtable *table;
1100 	int error;
1101 
1102 	if (so->so_pcb != NULL)
1103 		return EINVAL;
1104 
1105 	if ((error = soreserve(so, udp_sendspace, udp_recvspace)))
1106 		return error;
1107 
1108 	NET_ASSERT_LOCKED();
1109 #ifdef INET6
1110 	if (so->so_proto->pr_domain->dom_family == PF_INET6)
1111 		table = &udb6table;
1112 	else
1113 #endif
1114 		table = &udbtable;
1115 	if ((error = in_pcballoc(so, table, wait)))
1116 		return error;
1117 #ifdef INET6
1118 	if (sotoinpcb(so)->inp_flags & INP_IPV6)
1119 		sotoinpcb(so)->inp_ipv6.ip6_hlim = ip6_defhlim;
1120 	else
1121 #endif /* INET6 */
1122 		sotoinpcb(so)->inp_ip.ip_ttl = ip_defttl;
1123 	return 0;
1124 }
1125 
1126 int
1127 udp_detach(struct socket *so)
1128 {
1129 	struct inpcb *inp;
1130 
1131 	soassertlocked(so);
1132 
1133 	inp = sotoinpcb(so);
1134 	if (inp == NULL)
1135 		return (EINVAL);
1136 
1137 	in_pcbdetach(inp);
1138 	return (0);
1139 }
1140 
1141 void
1142 udp_lock(struct socket *so)
1143 {
1144 	struct inpcb *inp = sotoinpcb(so);
1145 
1146 	NET_ASSERT_LOCKED();
1147 	mtx_enter(&inp->inp_mtx);
1148 }
1149 
1150 void
1151 udp_unlock(struct socket *so)
1152 {
1153 	struct inpcb *inp = sotoinpcb(so);
1154 
1155 	NET_ASSERT_LOCKED();
1156 	mtx_leave(&inp->inp_mtx);
1157 }
1158 
1159 int
1160 udp_bind(struct socket *so, struct mbuf *addr, struct proc *p)
1161 {
1162 	struct inpcb *inp = sotoinpcb(so);
1163 
1164 	soassertlocked(so);
1165 	return in_pcbbind(inp, addr, p);
1166 }
1167 
1168 int
1169 udp_connect(struct socket *so, struct mbuf *addr)
1170 {
1171 	struct inpcb *inp = sotoinpcb(so);
1172 	int error;
1173 
1174 	soassertlocked(so);
1175 
1176 #ifdef INET6
1177 	if (inp->inp_flags & INP_IPV6) {
1178 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
1179 			return (EISCONN);
1180 	} else
1181 #endif /* INET6 */
1182 	{
1183 		if (inp->inp_faddr.s_addr != INADDR_ANY)
1184 			return (EISCONN);
1185 	}
1186 	error = in_pcbconnect(inp, addr);
1187 	if (error)
1188 		return (error);
1189 
1190 	soisconnected(so);
1191 	return (0);
1192 }
1193 
1194 int
1195 udp_disconnect(struct socket *so)
1196 {
1197 	struct inpcb *inp = sotoinpcb(so);
1198 
1199 	soassertlocked(so);
1200 
1201 #ifdef INET6
1202 	if (inp->inp_flags & INP_IPV6) {
1203 		if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
1204 			return (ENOTCONN);
1205 	} else
1206 #endif /* INET6 */
1207 	{
1208 		if (inp->inp_faddr.s_addr == INADDR_ANY)
1209 			return (ENOTCONN);
1210 	}
1211 	in_pcbunset_laddr(inp);
1212 	in_pcbdisconnect(inp);
1213 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1214 
1215 	return (0);
1216 }
1217 
1218 int
1219 udp_shutdown(struct socket *so)
1220 {
1221 	soassertlocked(so);
1222 	socantsendmore(so);
1223 	return (0);
1224 }
1225 
1226 int
1227 udp_send(struct socket *so, struct mbuf *m, struct mbuf *addr,
1228     struct mbuf *control)
1229 {
1230 	struct inpcb *inp = sotoinpcb(so);
1231 
1232 	soassertlocked(so);
1233 
1234 #ifdef PIPEX
1235 	if (inp->inp_pipex) {
1236 		struct pipex_session *session;
1237 
1238 		if (addr != NULL)
1239 			session =
1240 			    pipex_l2tp_userland_lookup_session(m,
1241 				mtod(addr, struct sockaddr *));
1242 		else
1243 #ifdef INET6
1244 		if (inp->inp_flags & INP_IPV6)
1245 			session =
1246 			    pipex_l2tp_userland_lookup_session_ipv6(
1247 				m, inp->inp_faddr6);
1248 		else
1249 #endif
1250 			session =
1251 			    pipex_l2tp_userland_lookup_session_ipv4(
1252 				m, inp->inp_faddr);
1253 		if (session != NULL) {
1254 			m = pipex_l2tp_userland_output(m, session);
1255 			pipex_rele_session(session);
1256 
1257 			if (m == NULL) {
1258 				m_freem(control);
1259 				return (ENOMEM);
1260 			}
1261 		}
1262 	}
1263 #endif
1264 
1265 	return (udp_output(inp, m, addr, control));
1266 }
1267 
1268 /*
1269  * Sysctl for udp variables.
1270  */
1271 int
1272 udp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
1273     size_t newlen)
1274 {
1275 	int error;
1276 
1277 	/* All sysctl names at this level are terminal. */
1278 	if (namelen != 1)
1279 		return (ENOTDIR);
1280 
1281 	switch (name[0]) {
1282 	case UDPCTL_BADDYNAMIC:
1283 		NET_LOCK();
1284 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1285 		    baddynamicports.udp, sizeof(baddynamicports.udp));
1286 		NET_UNLOCK();
1287 		return (error);
1288 
1289 	case UDPCTL_ROOTONLY:
1290 		if (newp && securelevel > 0)
1291 			return (EPERM);
1292 		NET_LOCK();
1293 		error = sysctl_struct(oldp, oldlenp, newp, newlen,
1294 		    rootonlyports.udp, sizeof(rootonlyports.udp));
1295 		NET_UNLOCK();
1296 		return (error);
1297 
1298 	case UDPCTL_STATS:
1299 		if (newp != NULL)
1300 			return (EPERM);
1301 
1302 		return (udp_sysctl_udpstat(oldp, oldlenp, newp));
1303 
1304 	default:
1305 		NET_LOCK();
1306 		error = sysctl_bounded_arr(udpctl_vars, nitems(udpctl_vars),
1307 		    name, namelen, oldp, oldlenp, newp, newlen);
1308 		NET_UNLOCK();
1309 		return (error);
1310 	}
1311 	/* NOTREACHED */
1312 }
1313 
1314 int
1315 udp_sysctl_udpstat(void *oldp, size_t *oldlenp, void *newp)
1316 {
1317 	uint64_t counters[udps_ncounters];
1318 	struct udpstat udpstat;
1319 	u_long *words = (u_long *)&udpstat;
1320 	int i;
1321 
1322 	CTASSERT(sizeof(udpstat) == (nitems(counters) * sizeof(u_long)));
1323 	memset(&udpstat, 0, sizeof udpstat);
1324 	counters_read(udpcounters, counters, nitems(counters), NULL);
1325 
1326 	for (i = 0; i < nitems(counters); i++)
1327 		words[i] = (u_long)counters[i];
1328 
1329 	return (sysctl_rdstruct(oldp, oldlenp, newp,
1330 	    &udpstat, sizeof(udpstat)));
1331 }
1332