xref: /netbsd-src/sys/netinet/udp_usrreq.c (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1 /*	$NetBSD: udp_usrreq.c,v 1.250 2018/05/01 08:42:41 maxv Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
61  */
62 
63 /*
64  * UDP protocol implementation.
65  * Per RFC 768, August, 1980.
66  */
67 
68 #include <sys/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.250 2018/05/01 08:42:41 maxv Exp $");
70 
71 #ifdef _KERNEL_OPT
72 #include "opt_inet.h"
73 #include "opt_ipsec.h"
74 #include "opt_inet_csum.h"
75 #include "opt_ipkdb.h"
76 #include "opt_mbuftrace.h"
77 #include "opt_net_mpsafe.h"
78 #endif
79 
80 #include <sys/param.h>
81 #include <sys/mbuf.h>
82 #include <sys/once.h>
83 #include <sys/protosw.h>
84 #include <sys/socket.h>
85 #include <sys/socketvar.h>
86 #include <sys/systm.h>
87 #include <sys/proc.h>
88 #include <sys/domain.h>
89 #include <sys/sysctl.h>
90 
91 #include <net/if.h>
92 
93 #include <netinet/in.h>
94 #include <netinet/in_systm.h>
95 #include <netinet/in_var.h>
96 #include <netinet/ip.h>
97 #include <netinet/in_pcb.h>
98 #include <netinet/ip_var.h>
99 #include <netinet/ip_icmp.h>
100 #include <netinet/udp.h>
101 #include <netinet/udp_var.h>
102 #include <netinet/udp_private.h>
103 
104 #ifdef INET6
105 #include <netinet/ip6.h>
106 #include <netinet6/ip6_var.h>
107 #include <netinet6/ip6_private.h>
108 #include <netinet6/in6_pcb.h>
109 #include <netinet6/udp6_var.h>
110 #include <netinet6/udp6_private.h>
111 #endif
112 
113 #ifndef INET6
114 /* always need ip6.h for IP6_EXTHDR_GET */
115 #include <netinet/ip6.h>
116 #endif
117 
118 #ifdef IPSEC
119 #include <netipsec/ipsec.h>
120 #include <netipsec/esp.h>
121 #endif
122 
123 #ifdef IPKDB
124 #include <ipkdb/ipkdb.h>
125 #endif
126 
127 int udpcksum = 1;
128 int udp_do_loopback_cksum = 0;
129 
130 struct inpcbtable udbtable;
131 
132 percpu_t *udpstat_percpu;
133 
134 #ifdef INET
135 #ifdef IPSEC
136 static int udp4_espinudp(struct mbuf **, int, struct socket *);
137 #endif
138 static void udp4_sendup(struct mbuf *, int, struct sockaddr *,
139     struct socket *);
140 static int udp4_realinput(struct sockaddr_in *, struct sockaddr_in *,
141     struct mbuf **, int);
142 static int udp4_input_checksum(struct mbuf *, const struct udphdr *, int, int);
143 #endif
144 #ifdef INET
145 static void udp_notify (struct inpcb *, int);
146 #endif
147 
148 #ifndef UDBHASHSIZE
149 #define	UDBHASHSIZE	128
150 #endif
151 int udbhashsize = UDBHASHSIZE;
152 
153 /*
154  * For send - really max datagram size; for receive - 40 1K datagrams.
155  */
156 static int udp_sendspace = 9216;
157 static int udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
158 
159 #ifdef MBUFTRACE
160 struct mowner udp_mowner = MOWNER_INIT("udp", "");
161 struct mowner udp_rx_mowner = MOWNER_INIT("udp", "rx");
162 struct mowner udp_tx_mowner = MOWNER_INIT("udp", "tx");
163 #endif
164 
165 #ifdef UDP_CSUM_COUNTERS
166 #include <sys/device.h>
167 
168 #if defined(INET)
169 struct evcnt udp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
170     NULL, "udp", "hwcsum bad");
171 struct evcnt udp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
172     NULL, "udp", "hwcsum ok");
173 struct evcnt udp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
174     NULL, "udp", "hwcsum data");
175 struct evcnt udp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
176     NULL, "udp", "swcsum");
177 
178 EVCNT_ATTACH_STATIC(udp_hwcsum_bad);
179 EVCNT_ATTACH_STATIC(udp_hwcsum_ok);
180 EVCNT_ATTACH_STATIC(udp_hwcsum_data);
181 EVCNT_ATTACH_STATIC(udp_swcsum);
182 #endif /* defined(INET) */
183 
184 #define	UDP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
185 #else
186 #define	UDP_CSUM_COUNTER_INCR(ev)	/* nothing */
187 #endif /* UDP_CSUM_COUNTERS */
188 
189 static void sysctl_net_inet_udp_setup(struct sysctllog **);
190 
191 static int
192 do_udpinit(void)
193 {
194 
195 	in_pcbinit(&udbtable, udbhashsize, udbhashsize);
196 	udpstat_percpu = percpu_alloc(sizeof(uint64_t) * UDP_NSTATS);
197 
198 	MOWNER_ATTACH(&udp_tx_mowner);
199 	MOWNER_ATTACH(&udp_rx_mowner);
200 	MOWNER_ATTACH(&udp_mowner);
201 
202 	return 0;
203 }
204 
205 void
206 udp_init_common(void)
207 {
208 	static ONCE_DECL(doudpinit);
209 
210 	RUN_ONCE(&doudpinit, do_udpinit);
211 }
212 
213 void
214 udp_init(void)
215 {
216 
217 	sysctl_net_inet_udp_setup(NULL);
218 
219 	udp_init_common();
220 }
221 
222 /*
223  * Checksum extended UDP header and data.
224  */
225 int
226 udp_input_checksum(int af, struct mbuf *m, const struct udphdr *uh,
227     int iphlen, int len)
228 {
229 
230 	switch (af) {
231 #ifdef INET
232 	case AF_INET:
233 		return udp4_input_checksum(m, uh, iphlen, len);
234 #endif
235 #ifdef INET6
236 	case AF_INET6:
237 		return udp6_input_checksum(m, uh, iphlen, len);
238 #endif
239 	}
240 #ifdef DIAGNOSTIC
241 	panic("udp_input_checksum: unknown af %d", af);
242 #endif
243 	/* NOTREACHED */
244 	return -1;
245 }
246 
247 #ifdef INET
248 
249 /*
250  * Checksum extended UDP header and data.
251  */
252 static int
253 udp4_input_checksum(struct mbuf *m, const struct udphdr *uh,
254     int iphlen, int len)
255 {
256 
257 	/*
258 	 * XXX it's better to record and check if this mbuf is
259 	 * already checked.
260 	 */
261 
262 	if (uh->uh_sum == 0)
263 		return 0;
264 
265 	switch (m->m_pkthdr.csum_flags &
266 	    ((m_get_rcvif_NOMPSAFE(m)->if_csum_flags_rx & M_CSUM_UDPv4) |
267 	    M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
268 	case M_CSUM_UDPv4|M_CSUM_TCP_UDP_BAD:
269 		UDP_CSUM_COUNTER_INCR(&udp_hwcsum_bad);
270 		goto badcsum;
271 
272 	case M_CSUM_UDPv4|M_CSUM_DATA: {
273 		u_int32_t hw_csum = m->m_pkthdr.csum_data;
274 
275 		UDP_CSUM_COUNTER_INCR(&udp_hwcsum_data);
276 		if (m->m_pkthdr.csum_flags & M_CSUM_NO_PSEUDOHDR) {
277 			const struct ip *ip =
278 			    mtod(m, const struct ip *);
279 
280 			hw_csum = in_cksum_phdr(ip->ip_src.s_addr,
281 			    ip->ip_dst.s_addr,
282 			    htons(hw_csum + len + IPPROTO_UDP));
283 		}
284 		if ((hw_csum ^ 0xffff) != 0)
285 			goto badcsum;
286 		break;
287 	}
288 
289 	case M_CSUM_UDPv4:
290 		/* Checksum was okay. */
291 		UDP_CSUM_COUNTER_INCR(&udp_hwcsum_ok);
292 		break;
293 
294 	default:
295 		/*
296 		 * Need to compute it ourselves.  Maybe skip checksum
297 		 * on loopback interfaces.
298 		 */
299 		if (__predict_true(!(m_get_rcvif_NOMPSAFE(m)->if_flags &
300 				     IFF_LOOPBACK) ||
301 				   udp_do_loopback_cksum)) {
302 			UDP_CSUM_COUNTER_INCR(&udp_swcsum);
303 			if (in4_cksum(m, IPPROTO_UDP, iphlen, len) != 0)
304 				goto badcsum;
305 		}
306 		break;
307 	}
308 
309 	return 0;
310 
311 badcsum:
312 	UDP_STATINC(UDP_STAT_BADSUM);
313 	return -1;
314 }
315 
316 void
317 udp_input(struct mbuf *m, ...)
318 {
319 	va_list ap;
320 	struct sockaddr_in src, dst;
321 	struct ip *ip;
322 	struct udphdr *uh;
323 	int iphlen;
324 	int len;
325 	int n;
326 	u_int16_t ip_len;
327 
328 	va_start(ap, m);
329 	iphlen = va_arg(ap, int);
330 	(void)va_arg(ap, int);		/* ignore value, advance ap */
331 	va_end(ap);
332 
333 	MCLAIM(m, &udp_rx_mowner);
334 	UDP_STATINC(UDP_STAT_IPACKETS);
335 
336 	/*
337 	 * Get IP and UDP header together in first mbuf.
338 	 */
339 	ip = mtod(m, struct ip *);
340 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
341 	if (uh == NULL) {
342 		UDP_STATINC(UDP_STAT_HDROPS);
343 		return;
344 	}
345 
346 	/*
347 	 * Enforce alignment requirements that are violated in
348 	 * some cases, see kern/50766 for details.
349 	 */
350 	if (UDP_HDR_ALIGNED_P(uh) == 0) {
351 		m = m_copyup(m, iphlen + sizeof(struct udphdr), 0);
352 		if (m == NULL) {
353 			UDP_STATINC(UDP_STAT_HDROPS);
354 			return;
355 		}
356 		ip = mtod(m, struct ip *);
357 		uh = (struct udphdr *)(mtod(m, char *) + iphlen);
358 	}
359 	KASSERT(UDP_HDR_ALIGNED_P(uh));
360 
361 	/* destination port of 0 is illegal, based on RFC768. */
362 	if (uh->uh_dport == 0)
363 		goto bad;
364 
365 	/*
366 	 * Make mbuf data length reflect UDP length.
367 	 * If not enough data to reflect UDP length, drop.
368 	 */
369 	ip_len = ntohs(ip->ip_len);
370 	len = ntohs((u_int16_t)uh->uh_ulen);
371 	if (len < sizeof(struct udphdr)) {
372 		UDP_STATINC(UDP_STAT_BADLEN);
373 		goto bad;
374 	}
375 	if (ip_len != iphlen + len) {
376 		if (ip_len < iphlen + len) {
377 			UDP_STATINC(UDP_STAT_BADLEN);
378 			goto bad;
379 		}
380 		m_adj(m, iphlen + len - ip_len);
381 	}
382 
383 	/*
384 	 * Checksum extended UDP header and data.
385 	 */
386 	if (udp4_input_checksum(m, uh, iphlen, len))
387 		goto badcsum;
388 
389 	/* construct source and dst sockaddrs. */
390 	sockaddr_in_init(&src, &ip->ip_src, uh->uh_sport);
391 	sockaddr_in_init(&dst, &ip->ip_dst, uh->uh_dport);
392 
393 	if ((n = udp4_realinput(&src, &dst, &m, iphlen)) == -1) {
394 		UDP_STATINC(UDP_STAT_HDROPS);
395 		return;
396 	}
397 	if (m == NULL) {
398 		/*
399 		 * packet has been processed by ESP stuff -
400 		 * e.g. dropped NAT-T-keep-alive-packet ...
401 		 */
402 		return;
403 	}
404 
405 	ip = mtod(m, struct ip *);
406 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
407 	if (uh == NULL) {
408 		UDP_STATINC(UDP_STAT_HDROPS);
409 		return;
410 	}
411 	/* XXX Re-enforce alignment? */
412 
413 #ifdef INET6
414 	if (IN_MULTICAST(ip->ip_dst.s_addr) || n == 0) {
415 		struct sockaddr_in6 src6, dst6;
416 
417 		memset(&src6, 0, sizeof(src6));
418 		src6.sin6_family = AF_INET6;
419 		src6.sin6_len = sizeof(struct sockaddr_in6);
420 		in6_in_2_v4mapin6(&ip->ip_src, &src6.sin6_addr);
421 		src6.sin6_port = uh->uh_sport;
422 		memset(&dst6, 0, sizeof(dst6));
423 		dst6.sin6_family = AF_INET6;
424 		dst6.sin6_len = sizeof(struct sockaddr_in6);
425 		in6_in_2_v4mapin6(&ip->ip_dst, &dst6.sin6_addr);
426 		dst6.sin6_port = uh->uh_dport;
427 
428 		n += udp6_realinput(AF_INET, &src6, &dst6, m, iphlen);
429 	}
430 #endif
431 
432 	if (n == 0) {
433 		if (m->m_flags & (M_BCAST | M_MCAST)) {
434 			UDP_STATINC(UDP_STAT_NOPORTBCAST);
435 			goto bad;
436 		}
437 		UDP_STATINC(UDP_STAT_NOPORT);
438 #ifdef IPKDB
439 		if (checkipkdb(&ip->ip_src, uh->uh_sport, uh->uh_dport,
440 		    m, iphlen + sizeof(struct udphdr),
441 		    m->m_pkthdr.len - iphlen - sizeof(struct udphdr))) {
442 			/*
443 			 * It was a debugger connect packet,
444 			 * just drop it now
445 			 */
446 			goto bad;
447 		}
448 #endif
449 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
450 		m = NULL;
451 	}
452 
453 bad:
454 	if (m)
455 		m_freem(m);
456 	return;
457 
458 badcsum:
459 	m_freem(m);
460 }
461 #endif
462 
463 #ifdef INET
464 static void
465 udp4_sendup(struct mbuf *m, int off /* offset of data portion */,
466     struct sockaddr *src, struct socket *so)
467 {
468 	struct mbuf *opts = NULL;
469 	struct mbuf *n;
470 	struct inpcb *inp;
471 
472 	KASSERT(so != NULL);
473 	KASSERT(so->so_proto->pr_domain->dom_family == AF_INET);
474 	inp = sotoinpcb(so);
475 	KASSERT(inp != NULL);
476 
477 #if defined(IPSEC)
478 	if (ipsec_used && ipsec_in_reject(m, inp)) {
479 		if ((n = m_copypacket(m, M_DONTWAIT)) != NULL)
480 			icmp_error(n, ICMP_UNREACH, ICMP_UNREACH_ADMIN_PROHIBIT,
481 			    0, 0);
482 		return;
483 	}
484 #endif
485 
486 	if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
487 		if (inp->inp_flags & INP_CONTROLOPTS ||
488 		    SOOPT_TIMESTAMP(so->so_options)) {
489 			struct ip *ip = mtod(n, struct ip *);
490 			ip_savecontrol(inp, &opts, ip, n);
491 		}
492 
493 		m_adj(n, off);
494 		if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
495 			m_freem(n);
496 			if (opts)
497 				m_freem(opts);
498 			UDP_STATINC(UDP_STAT_FULLSOCK);
499 			soroverflow(so);
500 		} else
501 			sorwakeup(so);
502 	}
503 }
504 #endif
505 
506 #ifdef INET
507 static int
508 udp4_realinput(struct sockaddr_in *src, struct sockaddr_in *dst,
509     struct mbuf **mp, int off /* offset of udphdr */)
510 {
511 	u_int16_t *sport, *dport;
512 	int rcvcnt;
513 	struct in_addr *src4, *dst4;
514 	struct inpcb_hdr *inph;
515 	struct inpcb *inp;
516 	struct mbuf *m = *mp;
517 
518 	rcvcnt = 0;
519 	off += sizeof(struct udphdr);	/* now, offset of payload */
520 
521 	if (src->sin_family != AF_INET || dst->sin_family != AF_INET)
522 		goto bad;
523 
524 	src4 = &src->sin_addr;
525 	sport = &src->sin_port;
526 	dst4 = &dst->sin_addr;
527 	dport = &dst->sin_port;
528 
529 	if (IN_MULTICAST(dst4->s_addr) ||
530 	    in_broadcast(*dst4, m_get_rcvif_NOMPSAFE(m))) {
531 		/*
532 		 * Deliver a multicast or broadcast datagram to *all* sockets
533 		 * for which the local and remote addresses and ports match
534 		 * those of the incoming datagram.  This allows more than
535 		 * one process to receive multi/broadcasts on the same port.
536 		 * (This really ought to be done for unicast datagrams as
537 		 * well, but that would cause problems with existing
538 		 * applications that open both address-specific sockets and
539 		 * a wildcard socket listening to the same port -- they would
540 		 * end up receiving duplicates of every unicast datagram.
541 		 * Those applications open the multiple sockets to overcome an
542 		 * inadequacy of the UDP socket interface, but for backwards
543 		 * compatibility we avoid the problem here rather than
544 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
545 		 */
546 
547 		/*
548 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
549 		 * we need udpiphdr for IPsec processing so we do that later.
550 		 */
551 		/*
552 		 * Locate pcb(s) for datagram.
553 		 */
554 		TAILQ_FOREACH(inph, &udbtable.inpt_queue, inph_queue) {
555 			inp = (struct inpcb *)inph;
556 			if (inp->inp_af != AF_INET)
557 				continue;
558 
559 			if (inp->inp_lport != *dport)
560 				continue;
561 			if (!in_nullhost(inp->inp_laddr)) {
562 				if (!in_hosteq(inp->inp_laddr, *dst4))
563 					continue;
564 			}
565 			if (!in_nullhost(inp->inp_faddr)) {
566 				if (!in_hosteq(inp->inp_faddr, *src4) ||
567 				    inp->inp_fport != *sport)
568 					continue;
569 			}
570 
571 			udp4_sendup(m, off, (struct sockaddr *)src,
572 			    inp->inp_socket);
573 			rcvcnt++;
574 
575 			/*
576 			 * Don't look for additional matches if this one does
577 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
578 			 * socket options set.  This heuristic avoids searching
579 			 * through all pcbs in the common case of a non-shared
580 			 * port.  It assumes that an application will never
581 			 * clear these options after setting them.
582 			 */
583 			if ((inp->inp_socket->so_options &
584 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
585 				break;
586 		}
587 	} else {
588 		/*
589 		 * Locate pcb for datagram.
590 		 */
591 		inp = in_pcblookup_connect(&udbtable, *src4, *sport, *dst4,
592 		    *dport, 0);
593 		if (inp == 0) {
594 			UDP_STATINC(UDP_STAT_PCBHASHMISS);
595 			inp = in_pcblookup_bind(&udbtable, *dst4, *dport);
596 			if (inp == 0)
597 				return rcvcnt;
598 		}
599 
600 #ifdef IPSEC
601 		/* Handle ESP over UDP */
602 		if (inp->inp_flags & INP_ESPINUDP_ALL) {
603 			switch (udp4_espinudp(mp, off, inp->inp_socket)) {
604 			case -1: /* Error, m was freed */
605 				rcvcnt = -1;
606 				goto bad;
607 
608 			case 1: /* ESP over UDP */
609 				rcvcnt++;
610 				goto bad;
611 
612 			case 0: /* plain UDP */
613 			default: /* Unexpected */
614 				/*
615 				 * Normal UDP processing will take place,
616 				 * m may have changed.
617 				 */
618 				m = *mp;
619 				break;
620 			}
621 		}
622 #endif
623 
624 		/*
625 		 * Check the minimum TTL for socket.
626 		 */
627 		if (mtod(m, struct ip *)->ip_ttl < inp->inp_ip_minttl)
628 			goto bad;
629 
630 		udp4_sendup(m, off, (struct sockaddr *)src, inp->inp_socket);
631 		rcvcnt++;
632 	}
633 
634 bad:
635 	return rcvcnt;
636 }
637 #endif
638 
639 #ifdef INET
640 /*
641  * Notify a udp user of an asynchronous error;
642  * just wake up so that he can collect error status.
643  */
644 static void
645 udp_notify(struct inpcb *inp, int errno)
646 {
647 	inp->inp_socket->so_error = errno;
648 	sorwakeup(inp->inp_socket);
649 	sowwakeup(inp->inp_socket);
650 }
651 
652 void *
653 udp_ctlinput(int cmd, const struct sockaddr *sa, void *v)
654 {
655 	struct ip *ip = v;
656 	struct udphdr *uh;
657 	void (*notify)(struct inpcb *, int) = udp_notify;
658 	int errno;
659 
660 	if (sa->sa_family != AF_INET ||
661 	    sa->sa_len != sizeof(struct sockaddr_in))
662 		return NULL;
663 	if ((unsigned)cmd >= PRC_NCMDS)
664 		return NULL;
665 
666 	errno = inetctlerrmap[cmd];
667 	if (PRC_IS_REDIRECT(cmd)) {
668 		notify = in_rtchange;
669 		ip = NULL;
670 	} else if (cmd == PRC_HOSTDEAD) {
671 		ip = NULL;
672 	} else if (errno == 0) {
673 		return NULL;
674 	}
675 
676 	if (ip) {
677 		uh = (struct udphdr *)((char *)ip + (ip->ip_hl << 2));
678 		in_pcbnotify(&udbtable, satocsin(sa)->sin_addr, uh->uh_dport,
679 		    ip->ip_src, uh->uh_sport, errno, notify);
680 		/* XXX mapped address case */
681 	} else {
682 		in_pcbnotifyall(&udbtable, satocsin(sa)->sin_addr, errno,
683 		    notify);
684 	}
685 
686 	return NULL;
687 }
688 
689 int
690 udp_ctloutput(int op, struct socket *so, struct sockopt *sopt)
691 {
692 	int s;
693 	int error = 0;
694 	struct inpcb *inp;
695 	int family;
696 	int optval;
697 
698 	family = so->so_proto->pr_domain->dom_family;
699 
700 	s = splsoftnet();
701 	switch (family) {
702 #ifdef INET
703 	case PF_INET:
704 		if (sopt->sopt_level != IPPROTO_UDP) {
705 			error = ip_ctloutput(op, so, sopt);
706 			goto end;
707 		}
708 		break;
709 #endif
710 #ifdef INET6
711 	case PF_INET6:
712 		if (sopt->sopt_level != IPPROTO_UDP) {
713 			error = ip6_ctloutput(op, so, sopt);
714 			goto end;
715 		}
716 		break;
717 #endif
718 	default:
719 		error = EAFNOSUPPORT;
720 		goto end;
721 	}
722 
723 
724 	switch (op) {
725 	case PRCO_SETOPT:
726 		inp = sotoinpcb(so);
727 
728 		switch (sopt->sopt_name) {
729 		case UDP_ENCAP:
730 			error = sockopt_getint(sopt, &optval);
731 			if (error)
732 				break;
733 
734 			switch(optval) {
735 			case 0:
736 				inp->inp_flags &= ~INP_ESPINUDP_ALL;
737 				break;
738 
739 			case UDP_ENCAP_ESPINUDP:
740 				inp->inp_flags &= ~INP_ESPINUDP_ALL;
741 				inp->inp_flags |= INP_ESPINUDP;
742 				break;
743 
744 			case UDP_ENCAP_ESPINUDP_NON_IKE:
745 				inp->inp_flags &= ~INP_ESPINUDP_ALL;
746 				inp->inp_flags |= INP_ESPINUDP_NON_IKE;
747 				break;
748 			default:
749 				error = EINVAL;
750 				break;
751 			}
752 			break;
753 
754 		default:
755 			error = ENOPROTOOPT;
756 			break;
757 		}
758 		break;
759 
760 	default:
761 		error = EINVAL;
762 		break;
763 	}
764 
765 end:
766 	splx(s);
767 	return error;
768 }
769 
770 int
771 udp_output(struct mbuf *m, struct inpcb *inp, struct mbuf *control,
772     struct lwp *l)
773 {
774 	struct udpiphdr *ui;
775 	struct route *ro;
776 	struct ip_pktopts pktopts;
777 	kauth_cred_t cred;
778 	int len = m->m_pkthdr.len;
779 	int error, flags = 0;
780 
781 	MCLAIM(m, &udp_tx_mowner);
782 
783 	/*
784 	 * Calculate data length and get a mbuf
785 	 * for UDP and IP headers.
786 	 */
787 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
788 	if (m == NULL) {
789 		error = ENOBUFS;
790 		goto release;
791 	}
792 
793 	/*
794 	 * Compute the packet length of the IP header, and
795 	 * punt if the length looks bogus.
796 	 */
797 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
798 		error = EMSGSIZE;
799 		goto release;
800 	}
801 
802 	if (l == NULL)
803 		cred = NULL;
804 	else
805 		cred = l->l_cred;
806 
807 	/* Setup IP outgoing packet options */
808 	memset(&pktopts, 0, sizeof(pktopts));
809 	error = ip_setpktopts(control, &pktopts, &flags, inp, cred);
810 	if (error != 0)
811 		goto release;
812 
813 	if (control != NULL) {
814 		m_freem(control);
815 		control = NULL;
816 	}
817 
818 	/*
819 	 * Fill in mbuf with extended UDP header
820 	 * and addresses and length put into network format.
821 	 */
822 	ui = mtod(m, struct udpiphdr *);
823 	ui->ui_pr = IPPROTO_UDP;
824 	ui->ui_src = pktopts.ippo_laddr.sin_addr;
825 	ui->ui_dst = inp->inp_faddr;
826 	ui->ui_sport = inp->inp_lport;
827 	ui->ui_dport = inp->inp_fport;
828 	ui->ui_ulen = htons((u_int16_t)len + sizeof(struct udphdr));
829 
830 	ro = &inp->inp_route;
831 
832 	/*
833 	 * Set up checksum and output datagram.
834 	 */
835 	if (udpcksum) {
836 		/*
837 		 * XXX Cache pseudo-header checksum part for
838 		 * XXX "connected" UDP sockets.
839 		 */
840 		ui->ui_sum = in_cksum_phdr(ui->ui_src.s_addr,
841 		    ui->ui_dst.s_addr, htons((u_int16_t)len +
842 		    sizeof(struct udphdr) + IPPROTO_UDP));
843 		m->m_pkthdr.csum_flags = M_CSUM_UDPv4;
844 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
845 	} else
846 		ui->ui_sum = 0;
847 
848 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
849 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;	/* XXX */
850 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;	/* XXX */
851 	UDP_STATINC(UDP_STAT_OPACKETS);
852 
853 	flags |= inp->inp_socket->so_options & (SO_DONTROUTE|SO_BROADCAST);
854 	return ip_output(m, inp->inp_options, ro, flags, pktopts.ippo_imo, inp);
855 
856  release:
857 	if (control != NULL)
858 		m_freem(control);
859 	m_freem(m);
860 	return error;
861 }
862 
863 static int
864 udp_attach(struct socket *so, int proto)
865 {
866 	struct inpcb *inp;
867 	int error;
868 
869 	KASSERT(sotoinpcb(so) == NULL);
870 
871 	/* Assign the lock (must happen even if we will error out). */
872 	sosetlock(so);
873 
874 #ifdef MBUFTRACE
875 	so->so_mowner = &udp_mowner;
876 	so->so_rcv.sb_mowner = &udp_rx_mowner;
877 	so->so_snd.sb_mowner = &udp_tx_mowner;
878 #endif
879 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
880 		error = soreserve(so, udp_sendspace, udp_recvspace);
881 		if (error) {
882 			return error;
883 		}
884 	}
885 
886 	error = in_pcballoc(so, &udbtable);
887 	if (error) {
888 		return error;
889 	}
890 	inp = sotoinpcb(so);
891 	inp->inp_ip.ip_ttl = ip_defttl;
892 	KASSERT(solocked(so));
893 
894 	return error;
895 }
896 
897 static void
898 udp_detach(struct socket *so)
899 {
900 	struct inpcb *inp;
901 
902 	KASSERT(solocked(so));
903 	inp = sotoinpcb(so);
904 	KASSERT(inp != NULL);
905 	in_pcbdetach(inp);
906 }
907 
908 static int
909 udp_accept(struct socket *so, struct sockaddr *nam)
910 {
911 	KASSERT(solocked(so));
912 
913 	panic("udp_accept");
914 
915 	return EOPNOTSUPP;
916 }
917 
918 static int
919 udp_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
920 {
921 	struct inpcb *inp = sotoinpcb(so);
922 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
923 	int error = 0;
924 	int s;
925 
926 	KASSERT(solocked(so));
927 	KASSERT(inp != NULL);
928 	KASSERT(nam != NULL);
929 
930 	s = splsoftnet();
931 	error = in_pcbbind(inp, sin, l);
932 	splx(s);
933 
934 	return error;
935 }
936 
937 static int
938 udp_listen(struct socket *so, struct lwp *l)
939 {
940 	KASSERT(solocked(so));
941 
942 	return EOPNOTSUPP;
943 }
944 
945 static int
946 udp_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
947 {
948 	struct inpcb *inp = sotoinpcb(so);
949 	int error = 0;
950 	int s;
951 
952 	KASSERT(solocked(so));
953 	KASSERT(inp != NULL);
954 	KASSERT(nam != NULL);
955 
956 	s = splsoftnet();
957 	error = in_pcbconnect(inp, (struct sockaddr_in *)nam, l);
958 	if (! error)
959 		soisconnected(so);
960 	splx(s);
961 	return error;
962 }
963 
964 static int
965 udp_connect2(struct socket *so, struct socket *so2)
966 {
967 	KASSERT(solocked(so));
968 
969 	return EOPNOTSUPP;
970 }
971 
972 static int
973 udp_disconnect(struct socket *so)
974 {
975 	struct inpcb *inp = sotoinpcb(so);
976 	int s;
977 
978 	KASSERT(solocked(so));
979 	KASSERT(inp != NULL);
980 
981 	s = splsoftnet();
982 	/*soisdisconnected(so);*/
983 	so->so_state &= ~SS_ISCONNECTED;	/* XXX */
984 	in_pcbdisconnect(inp);
985 	inp->inp_laddr = zeroin_addr;		/* XXX */
986 	in_pcbstate(inp, INP_BOUND);		/* XXX */
987 	splx(s);
988 
989 	return 0;
990 }
991 
992 static int
993 udp_shutdown(struct socket *so)
994 {
995 	int s;
996 
997 	KASSERT(solocked(so));
998 
999 	s = splsoftnet();
1000 	socantsendmore(so);
1001 	splx(s);
1002 
1003 	return 0;
1004 }
1005 
1006 static int
1007 udp_abort(struct socket *so)
1008 {
1009 	KASSERT(solocked(so));
1010 
1011 	panic("udp_abort");
1012 
1013 	return EOPNOTSUPP;
1014 }
1015 
1016 static int
1017 udp_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
1018 {
1019 	return in_control(so, cmd, nam, ifp);
1020 }
1021 
1022 static int
1023 udp_stat(struct socket *so, struct stat *ub)
1024 {
1025 	KASSERT(solocked(so));
1026 
1027 	/* stat: don't bother with a blocksize. */
1028 	return 0;
1029 }
1030 
1031 static int
1032 udp_peeraddr(struct socket *so, struct sockaddr *nam)
1033 {
1034 	int s;
1035 
1036 	KASSERT(solocked(so));
1037 	KASSERT(sotoinpcb(so) != NULL);
1038 	KASSERT(nam != NULL);
1039 
1040 	s = splsoftnet();
1041 	in_setpeeraddr(sotoinpcb(so), (struct sockaddr_in *)nam);
1042 	splx(s);
1043 
1044 	return 0;
1045 }
1046 
1047 static int
1048 udp_sockaddr(struct socket *so, struct sockaddr *nam)
1049 {
1050 	int s;
1051 
1052 	KASSERT(solocked(so));
1053 	KASSERT(sotoinpcb(so) != NULL);
1054 	KASSERT(nam != NULL);
1055 
1056 	s = splsoftnet();
1057 	in_setsockaddr(sotoinpcb(so), (struct sockaddr_in *)nam);
1058 	splx(s);
1059 
1060 	return 0;
1061 }
1062 
1063 static int
1064 udp_rcvd(struct socket *so, int flags, struct lwp *l)
1065 {
1066 	KASSERT(solocked(so));
1067 
1068 	return EOPNOTSUPP;
1069 }
1070 
1071 static int
1072 udp_recvoob(struct socket *so, struct mbuf *m, int flags)
1073 {
1074 	KASSERT(solocked(so));
1075 
1076 	return EOPNOTSUPP;
1077 }
1078 
1079 static int
1080 udp_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
1081     struct mbuf *control, struct lwp *l)
1082 {
1083 	struct inpcb *inp = sotoinpcb(so);
1084 	int error = 0;
1085 	struct in_addr laddr;			/* XXX */
1086 	int s;
1087 
1088 	KASSERT(solocked(so));
1089 	KASSERT(inp != NULL);
1090 	KASSERT(m != NULL);
1091 
1092 	memset(&laddr, 0, sizeof laddr);
1093 
1094 	s = splsoftnet();
1095 	if (nam) {
1096 		laddr = inp->inp_laddr;		/* XXX */
1097 		if ((so->so_state & SS_ISCONNECTED) != 0) {
1098 			error = EISCONN;
1099 			goto die;
1100 		}
1101 		error = in_pcbconnect(inp, (struct sockaddr_in *)nam, l);
1102 		if (error)
1103 			goto die;
1104 	} else {
1105 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1106 			error = ENOTCONN;
1107 			goto die;
1108 		}
1109 	}
1110 	error = udp_output(m, inp, control, l);
1111 	m = NULL;
1112 	control = NULL;
1113 	if (nam) {
1114 		in_pcbdisconnect(inp);
1115 		inp->inp_laddr = laddr;		/* XXX */
1116 		in_pcbstate(inp, INP_BOUND);	/* XXX */
1117 	}
1118   die:
1119 	if (m != NULL)
1120 		m_freem(m);
1121 	if (control != NULL)
1122 		m_freem(control);
1123 
1124 	splx(s);
1125 	return error;
1126 }
1127 
1128 static int
1129 udp_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
1130 {
1131 	KASSERT(solocked(so));
1132 
1133 	m_freem(m);
1134 	m_freem(control);
1135 
1136 	return EOPNOTSUPP;
1137 }
1138 
1139 static int
1140 udp_purgeif(struct socket *so, struct ifnet *ifp)
1141 {
1142 	int s;
1143 
1144 	s = splsoftnet();
1145 	mutex_enter(softnet_lock);
1146 	in_pcbpurgeif0(&udbtable, ifp);
1147 #ifdef NET_MPSAFE
1148 	mutex_exit(softnet_lock);
1149 #endif
1150 	in_purgeif(ifp);
1151 #ifdef NET_MPSAFE
1152 	mutex_enter(softnet_lock);
1153 #endif
1154 	in_pcbpurgeif(&udbtable, ifp);
1155 	mutex_exit(softnet_lock);
1156 	splx(s);
1157 
1158 	return 0;
1159 }
1160 
1161 static int
1162 sysctl_net_inet_udp_stats(SYSCTLFN_ARGS)
1163 {
1164 
1165 	return (NETSTAT_SYSCTL(udpstat_percpu, UDP_NSTATS));
1166 }
1167 
1168 /*
1169  * Sysctl for udp variables.
1170  */
1171 static void
1172 sysctl_net_inet_udp_setup(struct sysctllog **clog)
1173 {
1174 
1175 	sysctl_createv(clog, 0, NULL, NULL,
1176 		       CTLFLAG_PERMANENT,
1177 		       CTLTYPE_NODE, "inet", NULL,
1178 		       NULL, 0, NULL, 0,
1179 		       CTL_NET, PF_INET, CTL_EOL);
1180 	sysctl_createv(clog, 0, NULL, NULL,
1181 		       CTLFLAG_PERMANENT,
1182 		       CTLTYPE_NODE, "udp",
1183 		       SYSCTL_DESCR("UDPv4 related settings"),
1184 		       NULL, 0, NULL, 0,
1185 		       CTL_NET, PF_INET, IPPROTO_UDP, CTL_EOL);
1186 
1187 	sysctl_createv(clog, 0, NULL, NULL,
1188 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1189 		       CTLTYPE_INT, "checksum",
1190 		       SYSCTL_DESCR("Compute UDP checksums"),
1191 		       NULL, 0, &udpcksum, 0,
1192 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_CHECKSUM,
1193 		       CTL_EOL);
1194 	sysctl_createv(clog, 0, NULL, NULL,
1195 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1196 		       CTLTYPE_INT, "sendspace",
1197 		       SYSCTL_DESCR("Default UDP send buffer size"),
1198 		       NULL, 0, &udp_sendspace, 0,
1199 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_SENDSPACE,
1200 		       CTL_EOL);
1201 	sysctl_createv(clog, 0, NULL, NULL,
1202 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1203 		       CTLTYPE_INT, "recvspace",
1204 		       SYSCTL_DESCR("Default UDP receive buffer size"),
1205 		       NULL, 0, &udp_recvspace, 0,
1206 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_RECVSPACE,
1207 		       CTL_EOL);
1208 	sysctl_createv(clog, 0, NULL, NULL,
1209 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1210 		       CTLTYPE_INT, "do_loopback_cksum",
1211 		       SYSCTL_DESCR("Perform UDP checksum on loopback"),
1212 		       NULL, 0, &udp_do_loopback_cksum, 0,
1213 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_LOOPBACKCKSUM,
1214 		       CTL_EOL);
1215 	sysctl_createv(clog, 0, NULL, NULL,
1216 		       CTLFLAG_PERMANENT,
1217 		       CTLTYPE_STRUCT, "pcblist",
1218 		       SYSCTL_DESCR("UDP protocol control block list"),
1219 		       sysctl_inpcblist, 0, &udbtable, 0,
1220 		       CTL_NET, PF_INET, IPPROTO_UDP, CTL_CREATE,
1221 		       CTL_EOL);
1222 	sysctl_createv(clog, 0, NULL, NULL,
1223 		       CTLFLAG_PERMANENT,
1224 		       CTLTYPE_STRUCT, "stats",
1225 		       SYSCTL_DESCR("UDP statistics"),
1226 		       sysctl_net_inet_udp_stats, 0, NULL, 0,
1227 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_STATS,
1228 		       CTL_EOL);
1229 }
1230 #endif
1231 
1232 void
1233 udp_statinc(u_int stat)
1234 {
1235 
1236 	KASSERT(stat < UDP_NSTATS);
1237 	UDP_STATINC(stat);
1238 }
1239 
1240 #if defined(INET) && defined(IPSEC)
1241 /*
1242  * Returns:
1243  *     1 if the packet was processed
1244  *     0 if normal UDP processing should take place
1245  *    -1 if an error occurred and m was freed
1246  */
1247 static int
1248 udp4_espinudp(struct mbuf **mp, int off, struct socket *so)
1249 {
1250 	size_t len;
1251 	void *data;
1252 	struct inpcb *inp;
1253 	size_t skip = 0;
1254 	size_t minlen;
1255 	size_t iphdrlen;
1256 	struct ip *ip;
1257 	struct m_tag *tag;
1258 	struct udphdr *udphdr;
1259 	u_int16_t sport, dport;
1260 	struct mbuf *m = *mp;
1261 
1262 	/*
1263 	 * Collapse the mbuf chain if the first mbuf is too short
1264 	 * The longest case is: UDP + non ESP marker + ESP.
1265 	 */
1266 	minlen = off + sizeof(u_int64_t) + sizeof(struct esp);
1267 	if (minlen > m->m_pkthdr.len)
1268 		minlen = m->m_pkthdr.len;
1269 
1270 	if (m->m_len < minlen) {
1271 		if ((*mp = m_pullup(m, minlen)) == NULL) {
1272 			return -1;
1273 		}
1274 		m = *mp;
1275 	}
1276 
1277 	len = m->m_len - off;
1278 	data = mtod(m, char *) + off;
1279 	inp = sotoinpcb(so);
1280 
1281 	/* Ignore keepalive packets */
1282 	if ((len == 1) && (*(unsigned char *)data == 0xff)) {
1283 		m_freem(m);
1284 		*mp = NULL; /* avoid any further processing by caller ... */
1285 		return 1;
1286 	}
1287 
1288 	/*
1289 	 * Check that the payload is long enough to hold
1290 	 * an ESP header and compute the length of encapsulation
1291 	 * header to remove
1292 	 */
1293 	if (inp->inp_flags & INP_ESPINUDP) {
1294 		u_int32_t *st = (u_int32_t *)data;
1295 
1296 		if ((len <= sizeof(struct esp)) || (*st == 0))
1297 			return 0; /* Normal UDP processing */
1298 
1299 		skip = sizeof(struct udphdr);
1300 	}
1301 
1302 	if (inp->inp_flags & INP_ESPINUDP_NON_IKE) {
1303 		u_int32_t *st = (u_int32_t *)data;
1304 
1305 		if ((len <= sizeof(u_int64_t) + sizeof(struct esp)) ||
1306 		    ((st[0] | st[1]) != 0))
1307 			return 0; /* Normal UDP processing */
1308 
1309 		skip = sizeof(struct udphdr) + sizeof(u_int64_t);
1310 	}
1311 
1312 	/*
1313 	 * Get the UDP ports. They are handled in network
1314 	 * order everywhere in IPSEC_NAT_T code.
1315 	 */
1316 	udphdr = (struct udphdr *)((char *)data - skip);
1317 	sport = udphdr->uh_sport;
1318 	dport = udphdr->uh_dport;
1319 
1320 	/*
1321 	 * Remove the UDP header (and possibly the non ESP marker)
1322 	 * IP header length is iphdrlen
1323 	 * Before:
1324 	 *   <--- off --->
1325 	 *   +----+------+-----+
1326 	 *   | IP |  UDP | ESP |
1327 	 *   +----+------+-----+
1328 	 *        <-skip->
1329 	 * After:
1330 	 *          +----+-----+
1331 	 *          | IP | ESP |
1332 	 *          +----+-----+
1333 	 *   <-skip->
1334 	 */
1335 	iphdrlen = off - sizeof(struct udphdr);
1336 	memmove(mtod(m, char *) + skip, mtod(m, void *), iphdrlen);
1337 	m_adj(m, skip);
1338 
1339 	ip = mtod(m, struct ip *);
1340 	ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1341 	ip->ip_p = IPPROTO_ESP;
1342 
1343 	/*
1344 	 * We have modified the packet - it is now ESP, so we should not
1345 	 * return to UDP processing ...
1346 	 *
1347 	 * Add a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1348 	 * the source UDP port. This is required if we want
1349 	 * to select the right SPD for multiple hosts behind
1350 	 * same NAT
1351 	 */
1352 	if ((tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1353 	    sizeof(sport) + sizeof(dport), M_DONTWAIT)) == NULL) {
1354 		m_freem(m);
1355 		return -1;
1356 	}
1357 	((u_int16_t *)(tag + 1))[0] = sport;
1358 	((u_int16_t *)(tag + 1))[1] = dport;
1359 	m_tag_prepend(m, tag);
1360 
1361 	if (ipsec_used)
1362 		ipsec4_common_input(m, iphdrlen, IPPROTO_ESP);
1363 	else
1364 		m_freem(m);
1365 
1366 	/* We handled it, it shouldn't be handled by UDP */
1367 	*mp = NULL; /* avoid free by caller ... */
1368 	return 1;
1369 }
1370 #endif
1371 
1372 PR_WRAP_USRREQS(udp)
1373 #define	udp_attach	udp_attach_wrapper
1374 #define	udp_detach	udp_detach_wrapper
1375 #define	udp_accept	udp_accept_wrapper
1376 #define	udp_bind	udp_bind_wrapper
1377 #define	udp_listen	udp_listen_wrapper
1378 #define	udp_connect	udp_connect_wrapper
1379 #define	udp_connect2	udp_connect2_wrapper
1380 #define	udp_disconnect	udp_disconnect_wrapper
1381 #define	udp_shutdown	udp_shutdown_wrapper
1382 #define	udp_abort	udp_abort_wrapper
1383 #define	udp_ioctl	udp_ioctl_wrapper
1384 #define	udp_stat	udp_stat_wrapper
1385 #define	udp_peeraddr	udp_peeraddr_wrapper
1386 #define	udp_sockaddr	udp_sockaddr_wrapper
1387 #define	udp_rcvd	udp_rcvd_wrapper
1388 #define	udp_recvoob	udp_recvoob_wrapper
1389 #define	udp_send	udp_send_wrapper
1390 #define	udp_sendoob	udp_sendoob_wrapper
1391 #define	udp_purgeif	udp_purgeif_wrapper
1392 
1393 const struct pr_usrreqs udp_usrreqs = {
1394 	.pr_attach	= udp_attach,
1395 	.pr_detach	= udp_detach,
1396 	.pr_accept	= udp_accept,
1397 	.pr_bind	= udp_bind,
1398 	.pr_listen	= udp_listen,
1399 	.pr_connect	= udp_connect,
1400 	.pr_connect2	= udp_connect2,
1401 	.pr_disconnect	= udp_disconnect,
1402 	.pr_shutdown	= udp_shutdown,
1403 	.pr_abort	= udp_abort,
1404 	.pr_ioctl	= udp_ioctl,
1405 	.pr_stat	= udp_stat,
1406 	.pr_peeraddr	= udp_peeraddr,
1407 	.pr_sockaddr	= udp_sockaddr,
1408 	.pr_rcvd	= udp_rcvd,
1409 	.pr_recvoob	= udp_recvoob,
1410 	.pr_send	= udp_send,
1411 	.pr_sendoob	= udp_sendoob,
1412 	.pr_purgeif	= udp_purgeif,
1413 };
1414