xref: /netbsd-src/sys/netinet/udp_usrreq.c (revision 114ca20a4a7aa68e9c04e01636b83f9c6daf73e8)
1 /*	$NetBSD: udp_usrreq.c,v 1.252 2018/05/18 18:58:51 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 1.252 2018/05/18 18:58:51 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 #include <netinet/ip6.h>
115 #endif
116 
117 #ifdef IPSEC
118 #include <netipsec/ipsec.h>
119 #include <netipsec/esp.h>
120 #endif
121 
122 #ifdef IPKDB
123 #include <ipkdb/ipkdb.h>
124 #endif
125 
126 int udpcksum = 1;
127 int udp_do_loopback_cksum = 0;
128 
129 struct inpcbtable udbtable;
130 
131 percpu_t *udpstat_percpu;
132 
133 #ifdef INET
134 #ifdef IPSEC
135 static int udp4_espinudp(struct mbuf **, int, struct socket *);
136 #endif
137 static void udp4_sendup(struct mbuf *, int, struct sockaddr *,
138     struct socket *);
139 static int udp4_realinput(struct sockaddr_in *, struct sockaddr_in *,
140     struct mbuf **, int);
141 static int udp4_input_checksum(struct mbuf *, const struct udphdr *, int, int);
142 #endif
143 #ifdef INET
144 static void udp_notify (struct inpcb *, int);
145 #endif
146 
147 #ifndef UDBHASHSIZE
148 #define	UDBHASHSIZE	128
149 #endif
150 int udbhashsize = UDBHASHSIZE;
151 
152 /*
153  * For send - really max datagram size; for receive - 40 1K datagrams.
154  */
155 static int udp_sendspace = 9216;
156 static int udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
157 
158 #ifdef MBUFTRACE
159 struct mowner udp_mowner = MOWNER_INIT("udp", "");
160 struct mowner udp_rx_mowner = MOWNER_INIT("udp", "rx");
161 struct mowner udp_tx_mowner = MOWNER_INIT("udp", "tx");
162 #endif
163 
164 #ifdef UDP_CSUM_COUNTERS
165 #include <sys/device.h>
166 
167 #if defined(INET)
168 struct evcnt udp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
169     NULL, "udp", "hwcsum bad");
170 struct evcnt udp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
171     NULL, "udp", "hwcsum ok");
172 struct evcnt udp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
173     NULL, "udp", "hwcsum data");
174 struct evcnt udp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
175     NULL, "udp", "swcsum");
176 
177 EVCNT_ATTACH_STATIC(udp_hwcsum_bad);
178 EVCNT_ATTACH_STATIC(udp_hwcsum_ok);
179 EVCNT_ATTACH_STATIC(udp_hwcsum_data);
180 EVCNT_ATTACH_STATIC(udp_swcsum);
181 #endif /* defined(INET) */
182 
183 #define	UDP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
184 #else
185 #define	UDP_CSUM_COUNTER_INCR(ev)	/* nothing */
186 #endif /* UDP_CSUM_COUNTERS */
187 
188 static void sysctl_net_inet_udp_setup(struct sysctllog **);
189 
190 static int
191 do_udpinit(void)
192 {
193 
194 	in_pcbinit(&udbtable, udbhashsize, udbhashsize);
195 	udpstat_percpu = percpu_alloc(sizeof(uint64_t) * UDP_NSTATS);
196 
197 	MOWNER_ATTACH(&udp_tx_mowner);
198 	MOWNER_ATTACH(&udp_rx_mowner);
199 	MOWNER_ATTACH(&udp_mowner);
200 
201 	return 0;
202 }
203 
204 void
205 udp_init_common(void)
206 {
207 	static ONCE_DECL(doudpinit);
208 
209 	RUN_ONCE(&doudpinit, do_udpinit);
210 }
211 
212 void
213 udp_init(void)
214 {
215 
216 	sysctl_net_inet_udp_setup(NULL);
217 
218 	udp_init_common();
219 }
220 
221 /*
222  * Checksum extended UDP header and data.
223  */
224 int
225 udp_input_checksum(int af, struct mbuf *m, const struct udphdr *uh,
226     int iphlen, int len)
227 {
228 
229 	switch (af) {
230 #ifdef INET
231 	case AF_INET:
232 		return udp4_input_checksum(m, uh, iphlen, len);
233 #endif
234 #ifdef INET6
235 	case AF_INET6:
236 		return udp6_input_checksum(m, uh, iphlen, len);
237 #endif
238 	}
239 #ifdef DIAGNOSTIC
240 	panic("udp_input_checksum: unknown af %d", af);
241 #endif
242 	/* NOTREACHED */
243 	return -1;
244 }
245 
246 #ifdef INET
247 
248 /*
249  * Checksum extended UDP header and data.
250  */
251 static int
252 udp4_input_checksum(struct mbuf *m, const struct udphdr *uh,
253     int iphlen, int len)
254 {
255 
256 	/*
257 	 * XXX it's better to record and check if this mbuf is
258 	 * already checked.
259 	 */
260 
261 	if (uh->uh_sum == 0)
262 		return 0;
263 
264 	switch (m->m_pkthdr.csum_flags &
265 	    ((m_get_rcvif_NOMPSAFE(m)->if_csum_flags_rx & M_CSUM_UDPv4) |
266 	    M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
267 	case M_CSUM_UDPv4|M_CSUM_TCP_UDP_BAD:
268 		UDP_CSUM_COUNTER_INCR(&udp_hwcsum_bad);
269 		goto badcsum;
270 
271 	case M_CSUM_UDPv4|M_CSUM_DATA: {
272 		u_int32_t hw_csum = m->m_pkthdr.csum_data;
273 
274 		UDP_CSUM_COUNTER_INCR(&udp_hwcsum_data);
275 		if (m->m_pkthdr.csum_flags & M_CSUM_NO_PSEUDOHDR) {
276 			const struct ip *ip =
277 			    mtod(m, const struct ip *);
278 
279 			hw_csum = in_cksum_phdr(ip->ip_src.s_addr,
280 			    ip->ip_dst.s_addr,
281 			    htons(hw_csum + len + IPPROTO_UDP));
282 		}
283 		if ((hw_csum ^ 0xffff) != 0)
284 			goto badcsum;
285 		break;
286 	}
287 
288 	case M_CSUM_UDPv4:
289 		/* Checksum was okay. */
290 		UDP_CSUM_COUNTER_INCR(&udp_hwcsum_ok);
291 		break;
292 
293 	default:
294 		/*
295 		 * Need to compute it ourselves.  Maybe skip checksum
296 		 * on loopback interfaces.
297 		 */
298 		if (__predict_true(!(m_get_rcvif_NOMPSAFE(m)->if_flags &
299 				     IFF_LOOPBACK) ||
300 				   udp_do_loopback_cksum)) {
301 			UDP_CSUM_COUNTER_INCR(&udp_swcsum);
302 			if (in4_cksum(m, IPPROTO_UDP, iphlen, len) != 0)
303 				goto badcsum;
304 		}
305 		break;
306 	}
307 
308 	return 0;
309 
310 badcsum:
311 	UDP_STATINC(UDP_STAT_BADSUM);
312 	return -1;
313 }
314 
315 void
316 udp_input(struct mbuf *m, ...)
317 {
318 	va_list ap;
319 	struct sockaddr_in src, dst;
320 	struct ip *ip;
321 	struct udphdr *uh;
322 	int iphlen;
323 	int len;
324 	int n;
325 	u_int16_t ip_len;
326 
327 	va_start(ap, m);
328 	iphlen = va_arg(ap, int);
329 	(void)va_arg(ap, int);		/* ignore value, advance ap */
330 	va_end(ap);
331 
332 	MCLAIM(m, &udp_rx_mowner);
333 	UDP_STATINC(UDP_STAT_IPACKETS);
334 
335 	/*
336 	 * Get IP and UDP header together in first mbuf.
337 	 */
338 	ip = mtod(m, struct ip *);
339 	M_REGION_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
340 	if (uh == NULL) {
341 		UDP_STATINC(UDP_STAT_HDROPS);
342 		return;
343 	}
344 
345 	/*
346 	 * Enforce alignment requirements that are violated in
347 	 * some cases, see kern/50766 for details.
348 	 */
349 	if (UDP_HDR_ALIGNED_P(uh) == 0) {
350 		m = m_copyup(m, iphlen + sizeof(struct udphdr), 0);
351 		if (m == NULL) {
352 			UDP_STATINC(UDP_STAT_HDROPS);
353 			return;
354 		}
355 		ip = mtod(m, struct ip *);
356 		uh = (struct udphdr *)(mtod(m, char *) + iphlen);
357 	}
358 	KASSERT(UDP_HDR_ALIGNED_P(uh));
359 
360 	/* destination port of 0 is illegal, based on RFC768. */
361 	if (uh->uh_dport == 0)
362 		goto bad;
363 
364 	/*
365 	 * Make mbuf data length reflect UDP length.
366 	 * If not enough data to reflect UDP length, drop.
367 	 */
368 	ip_len = ntohs(ip->ip_len);
369 	len = ntohs((u_int16_t)uh->uh_ulen);
370 	if (len < sizeof(struct udphdr)) {
371 		UDP_STATINC(UDP_STAT_BADLEN);
372 		goto bad;
373 	}
374 	if (ip_len != iphlen + len) {
375 		if (ip_len < iphlen + len) {
376 			UDP_STATINC(UDP_STAT_BADLEN);
377 			goto bad;
378 		}
379 		m_adj(m, iphlen + len - ip_len);
380 	}
381 
382 	/*
383 	 * Checksum extended UDP header and data.
384 	 */
385 	if (udp4_input_checksum(m, uh, iphlen, len))
386 		goto badcsum;
387 
388 	/* construct source and dst sockaddrs. */
389 	sockaddr_in_init(&src, &ip->ip_src, uh->uh_sport);
390 	sockaddr_in_init(&dst, &ip->ip_dst, uh->uh_dport);
391 
392 	if ((n = udp4_realinput(&src, &dst, &m, iphlen)) == -1) {
393 		UDP_STATINC(UDP_STAT_HDROPS);
394 		return;
395 	}
396 	if (m == NULL) {
397 		/*
398 		 * packet has been processed by ESP stuff -
399 		 * e.g. dropped NAT-T-keep-alive-packet ...
400 		 */
401 		return;
402 	}
403 
404 	ip = mtod(m, struct ip *);
405 	M_REGION_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
406 	if (uh == NULL) {
407 		UDP_STATINC(UDP_STAT_HDROPS);
408 		return;
409 	}
410 	/* XXX Re-enforce alignment? */
411 
412 #ifdef INET6
413 	if (IN_MULTICAST(ip->ip_dst.s_addr) || n == 0) {
414 		struct sockaddr_in6 src6, dst6;
415 
416 		memset(&src6, 0, sizeof(src6));
417 		src6.sin6_family = AF_INET6;
418 		src6.sin6_len = sizeof(struct sockaddr_in6);
419 		in6_in_2_v4mapin6(&ip->ip_src, &src6.sin6_addr);
420 		src6.sin6_port = uh->uh_sport;
421 		memset(&dst6, 0, sizeof(dst6));
422 		dst6.sin6_family = AF_INET6;
423 		dst6.sin6_len = sizeof(struct sockaddr_in6);
424 		in6_in_2_v4mapin6(&ip->ip_dst, &dst6.sin6_addr);
425 		dst6.sin6_port = uh->uh_dport;
426 
427 		n += udp6_realinput(AF_INET, &src6, &dst6, m, iphlen);
428 	}
429 #endif
430 
431 	if (n == 0) {
432 		if (m->m_flags & (M_BCAST | M_MCAST)) {
433 			UDP_STATINC(UDP_STAT_NOPORTBCAST);
434 			goto bad;
435 		}
436 		UDP_STATINC(UDP_STAT_NOPORT);
437 #ifdef IPKDB
438 		if (checkipkdb(&ip->ip_src, uh->uh_sport, uh->uh_dport,
439 		    m, iphlen + sizeof(struct udphdr),
440 		    m->m_pkthdr.len - iphlen - sizeof(struct udphdr))) {
441 			/*
442 			 * It was a debugger connect packet,
443 			 * just drop it now
444 			 */
445 			goto bad;
446 		}
447 #endif
448 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
449 		m = NULL;
450 	}
451 
452 bad:
453 	if (m)
454 		m_freem(m);
455 	return;
456 
457 badcsum:
458 	m_freem(m);
459 }
460 #endif
461 
462 #ifdef INET
463 static void
464 udp4_sendup(struct mbuf *m, int off /* offset of data portion */,
465     struct sockaddr *src, struct socket *so)
466 {
467 	struct mbuf *opts = NULL;
468 	struct mbuf *n;
469 	struct inpcb *inp;
470 
471 	KASSERT(so != NULL);
472 	KASSERT(so->so_proto->pr_domain->dom_family == AF_INET);
473 	inp = sotoinpcb(so);
474 	KASSERT(inp != NULL);
475 
476 #if defined(IPSEC)
477 	if (ipsec_used && ipsec_in_reject(m, inp)) {
478 		if ((n = m_copypacket(m, M_DONTWAIT)) != NULL)
479 			icmp_error(n, ICMP_UNREACH, ICMP_UNREACH_ADMIN_PROHIBIT,
480 			    0, 0);
481 		return;
482 	}
483 #endif
484 
485 	if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
486 		if (inp->inp_flags & INP_CONTROLOPTS ||
487 		    SOOPT_TIMESTAMP(so->so_options)) {
488 			struct ip *ip = mtod(n, struct ip *);
489 			ip_savecontrol(inp, &opts, ip, n);
490 		}
491 
492 		m_adj(n, off);
493 		if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
494 			m_freem(n);
495 			if (opts)
496 				m_freem(opts);
497 			UDP_STATINC(UDP_STAT_FULLSOCK);
498 			soroverflow(so);
499 		} else
500 			sorwakeup(so);
501 	}
502 }
503 #endif
504 
505 #ifdef INET
506 static int
507 udp4_realinput(struct sockaddr_in *src, struct sockaddr_in *dst,
508     struct mbuf **mp, int off /* offset of udphdr */)
509 {
510 	u_int16_t *sport, *dport;
511 	int rcvcnt;
512 	struct in_addr *src4, *dst4;
513 	struct inpcb_hdr *inph;
514 	struct inpcb *inp;
515 	struct mbuf *m = *mp;
516 
517 	rcvcnt = 0;
518 	off += sizeof(struct udphdr);	/* now, offset of payload */
519 
520 	if (src->sin_family != AF_INET || dst->sin_family != AF_INET)
521 		goto bad;
522 
523 	src4 = &src->sin_addr;
524 	sport = &src->sin_port;
525 	dst4 = &dst->sin_addr;
526 	dport = &dst->sin_port;
527 
528 	if (IN_MULTICAST(dst4->s_addr) ||
529 	    in_broadcast(*dst4, m_get_rcvif_NOMPSAFE(m))) {
530 		/*
531 		 * Deliver a multicast or broadcast datagram to *all* sockets
532 		 * for which the local and remote addresses and ports match
533 		 * those of the incoming datagram.  This allows more than
534 		 * one process to receive multi/broadcasts on the same port.
535 		 * (This really ought to be done for unicast datagrams as
536 		 * well, but that would cause problems with existing
537 		 * applications that open both address-specific sockets and
538 		 * a wildcard socket listening to the same port -- they would
539 		 * end up receiving duplicates of every unicast datagram.
540 		 * Those applications open the multiple sockets to overcome an
541 		 * inadequacy of the UDP socket interface, but for backwards
542 		 * compatibility we avoid the problem here rather than
543 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
544 		 */
545 
546 		/*
547 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
548 		 * we need udpiphdr for IPsec processing so we do that later.
549 		 */
550 		/*
551 		 * Locate pcb(s) for datagram.
552 		 */
553 		TAILQ_FOREACH(inph, &udbtable.inpt_queue, inph_queue) {
554 			inp = (struct inpcb *)inph;
555 			if (inp->inp_af != AF_INET)
556 				continue;
557 
558 			if (inp->inp_lport != *dport)
559 				continue;
560 			if (!in_nullhost(inp->inp_laddr)) {
561 				if (!in_hosteq(inp->inp_laddr, *dst4))
562 					continue;
563 			}
564 			if (!in_nullhost(inp->inp_faddr)) {
565 				if (!in_hosteq(inp->inp_faddr, *src4) ||
566 				    inp->inp_fport != *sport)
567 					continue;
568 			}
569 
570 			udp4_sendup(m, off, (struct sockaddr *)src,
571 			    inp->inp_socket);
572 			rcvcnt++;
573 
574 			/*
575 			 * Don't look for additional matches if this one does
576 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
577 			 * socket options set.  This heuristic avoids searching
578 			 * through all pcbs in the common case of a non-shared
579 			 * port.  It assumes that an application will never
580 			 * clear these options after setting them.
581 			 */
582 			if ((inp->inp_socket->so_options &
583 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
584 				break;
585 		}
586 	} else {
587 		/*
588 		 * Locate pcb for datagram.
589 		 */
590 		inp = in_pcblookup_connect(&udbtable, *src4, *sport, *dst4,
591 		    *dport, 0);
592 		if (inp == 0) {
593 			UDP_STATINC(UDP_STAT_PCBHASHMISS);
594 			inp = in_pcblookup_bind(&udbtable, *dst4, *dport);
595 			if (inp == 0)
596 				return rcvcnt;
597 		}
598 
599 #ifdef IPSEC
600 		/* Handle ESP over UDP */
601 		if (inp->inp_flags & INP_ESPINUDP_ALL) {
602 			switch (udp4_espinudp(mp, off, inp->inp_socket)) {
603 			case -1: /* Error, m was freed */
604 				rcvcnt = -1;
605 				goto bad;
606 
607 			case 1: /* ESP over UDP */
608 				rcvcnt++;
609 				goto bad;
610 
611 			case 0: /* plain UDP */
612 			default: /* Unexpected */
613 				/*
614 				 * Normal UDP processing will take place,
615 				 * m may have changed.
616 				 */
617 				m = *mp;
618 				break;
619 			}
620 		}
621 #endif
622 
623 		/*
624 		 * Check the minimum TTL for socket.
625 		 */
626 		if (mtod(m, struct ip *)->ip_ttl < inp->inp_ip_minttl)
627 			goto bad;
628 
629 		udp4_sendup(m, off, (struct sockaddr *)src, inp->inp_socket);
630 		rcvcnt++;
631 	}
632 
633 bad:
634 	return rcvcnt;
635 }
636 #endif
637 
638 #ifdef INET
639 /*
640  * Notify a udp user of an asynchronous error;
641  * just wake up so that he can collect error status.
642  */
643 static void
644 udp_notify(struct inpcb *inp, int errno)
645 {
646 	inp->inp_socket->so_error = errno;
647 	sorwakeup(inp->inp_socket);
648 	sowwakeup(inp->inp_socket);
649 }
650 
651 void *
652 udp_ctlinput(int cmd, const struct sockaddr *sa, void *v)
653 {
654 	struct ip *ip = v;
655 	struct udphdr *uh;
656 	void (*notify)(struct inpcb *, int) = udp_notify;
657 	int errno;
658 
659 	if (sa->sa_family != AF_INET ||
660 	    sa->sa_len != sizeof(struct sockaddr_in))
661 		return NULL;
662 	if ((unsigned)cmd >= PRC_NCMDS)
663 		return NULL;
664 
665 	errno = inetctlerrmap[cmd];
666 	if (PRC_IS_REDIRECT(cmd)) {
667 		notify = in_rtchange;
668 		ip = NULL;
669 	} else if (cmd == PRC_HOSTDEAD) {
670 		ip = NULL;
671 	} else if (errno == 0) {
672 		return NULL;
673 	}
674 
675 	if (ip) {
676 		uh = (struct udphdr *)((char *)ip + (ip->ip_hl << 2));
677 		in_pcbnotify(&udbtable, satocsin(sa)->sin_addr, uh->uh_dport,
678 		    ip->ip_src, uh->uh_sport, errno, notify);
679 		/* XXX mapped address case */
680 	} else {
681 		in_pcbnotifyall(&udbtable, satocsin(sa)->sin_addr, errno,
682 		    notify);
683 	}
684 
685 	return NULL;
686 }
687 
688 int
689 udp_ctloutput(int op, struct socket *so, struct sockopt *sopt)
690 {
691 	int s;
692 	int error = 0;
693 	struct inpcb *inp;
694 	int family;
695 	int optval;
696 
697 	family = so->so_proto->pr_domain->dom_family;
698 
699 	s = splsoftnet();
700 	switch (family) {
701 #ifdef INET
702 	case PF_INET:
703 		if (sopt->sopt_level != IPPROTO_UDP) {
704 			error = ip_ctloutput(op, so, sopt);
705 			goto end;
706 		}
707 		break;
708 #endif
709 #ifdef INET6
710 	case PF_INET6:
711 		if (sopt->sopt_level != IPPROTO_UDP) {
712 			error = ip6_ctloutput(op, so, sopt);
713 			goto end;
714 		}
715 		break;
716 #endif
717 	default:
718 		error = EAFNOSUPPORT;
719 		goto end;
720 	}
721 
722 
723 	switch (op) {
724 	case PRCO_SETOPT:
725 		inp = sotoinpcb(so);
726 
727 		switch (sopt->sopt_name) {
728 		case UDP_ENCAP:
729 			error = sockopt_getint(sopt, &optval);
730 			if (error)
731 				break;
732 
733 			switch(optval) {
734 			case 0:
735 				inp->inp_flags &= ~INP_ESPINUDP_ALL;
736 				break;
737 
738 			case UDP_ENCAP_ESPINUDP:
739 				inp->inp_flags &= ~INP_ESPINUDP_ALL;
740 				inp->inp_flags |= INP_ESPINUDP;
741 				break;
742 
743 			case UDP_ENCAP_ESPINUDP_NON_IKE:
744 				inp->inp_flags &= ~INP_ESPINUDP_ALL;
745 				inp->inp_flags |= INP_ESPINUDP_NON_IKE;
746 				break;
747 			default:
748 				error = EINVAL;
749 				break;
750 			}
751 			break;
752 
753 		default:
754 			error = ENOPROTOOPT;
755 			break;
756 		}
757 		break;
758 
759 	default:
760 		error = EINVAL;
761 		break;
762 	}
763 
764 end:
765 	splx(s);
766 	return error;
767 }
768 
769 int
770 udp_output(struct mbuf *m, struct inpcb *inp, struct mbuf *control,
771     struct lwp *l)
772 {
773 	struct udpiphdr *ui;
774 	struct route *ro;
775 	struct ip_pktopts pktopts;
776 	kauth_cred_t cred;
777 	int len = m->m_pkthdr.len;
778 	int error, flags = 0;
779 
780 	MCLAIM(m, &udp_tx_mowner);
781 
782 	/*
783 	 * Calculate data length and get a mbuf
784 	 * for UDP and IP headers.
785 	 */
786 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
787 	if (m == NULL) {
788 		error = ENOBUFS;
789 		goto release;
790 	}
791 
792 	/*
793 	 * Compute the packet length of the IP header, and
794 	 * punt if the length looks bogus.
795 	 */
796 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
797 		error = EMSGSIZE;
798 		goto release;
799 	}
800 
801 	if (l == NULL)
802 		cred = NULL;
803 	else
804 		cred = l->l_cred;
805 
806 	/* Setup IP outgoing packet options */
807 	memset(&pktopts, 0, sizeof(pktopts));
808 	error = ip_setpktopts(control, &pktopts, &flags, inp, cred);
809 	if (error != 0)
810 		goto release;
811 
812 	if (control != NULL) {
813 		m_freem(control);
814 		control = NULL;
815 	}
816 
817 	/*
818 	 * Fill in mbuf with extended UDP header
819 	 * and addresses and length put into network format.
820 	 */
821 	ui = mtod(m, struct udpiphdr *);
822 	ui->ui_pr = IPPROTO_UDP;
823 	ui->ui_src = pktopts.ippo_laddr.sin_addr;
824 	ui->ui_dst = inp->inp_faddr;
825 	ui->ui_sport = inp->inp_lport;
826 	ui->ui_dport = inp->inp_fport;
827 	ui->ui_ulen = htons((u_int16_t)len + sizeof(struct udphdr));
828 
829 	ro = &inp->inp_route;
830 
831 	/*
832 	 * Set up checksum and output datagram.
833 	 */
834 	if (udpcksum) {
835 		/*
836 		 * XXX Cache pseudo-header checksum part for
837 		 * XXX "connected" UDP sockets.
838 		 */
839 		ui->ui_sum = in_cksum_phdr(ui->ui_src.s_addr,
840 		    ui->ui_dst.s_addr, htons((u_int16_t)len +
841 		    sizeof(struct udphdr) + IPPROTO_UDP));
842 		m->m_pkthdr.csum_flags = M_CSUM_UDPv4;
843 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
844 	} else
845 		ui->ui_sum = 0;
846 
847 	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
848 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;	/* XXX */
849 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;	/* XXX */
850 	UDP_STATINC(UDP_STAT_OPACKETS);
851 
852 	flags |= inp->inp_socket->so_options & (SO_DONTROUTE|SO_BROADCAST);
853 	return ip_output(m, inp->inp_options, ro, flags, pktopts.ippo_imo, inp);
854 
855  release:
856 	if (control != NULL)
857 		m_freem(control);
858 	m_freem(m);
859 	return error;
860 }
861 
862 static int
863 udp_attach(struct socket *so, int proto)
864 {
865 	struct inpcb *inp;
866 	int error;
867 
868 	KASSERT(sotoinpcb(so) == NULL);
869 
870 	/* Assign the lock (must happen even if we will error out). */
871 	sosetlock(so);
872 
873 #ifdef MBUFTRACE
874 	so->so_mowner = &udp_mowner;
875 	so->so_rcv.sb_mowner = &udp_rx_mowner;
876 	so->so_snd.sb_mowner = &udp_tx_mowner;
877 #endif
878 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
879 		error = soreserve(so, udp_sendspace, udp_recvspace);
880 		if (error) {
881 			return error;
882 		}
883 	}
884 
885 	error = in_pcballoc(so, &udbtable);
886 	if (error) {
887 		return error;
888 	}
889 	inp = sotoinpcb(so);
890 	inp->inp_ip.ip_ttl = ip_defttl;
891 	KASSERT(solocked(so));
892 
893 	return error;
894 }
895 
896 static void
897 udp_detach(struct socket *so)
898 {
899 	struct inpcb *inp;
900 
901 	KASSERT(solocked(so));
902 	inp = sotoinpcb(so);
903 	KASSERT(inp != NULL);
904 	in_pcbdetach(inp);
905 }
906 
907 static int
908 udp_accept(struct socket *so, struct sockaddr *nam)
909 {
910 	KASSERT(solocked(so));
911 
912 	panic("udp_accept");
913 
914 	return EOPNOTSUPP;
915 }
916 
917 static int
918 udp_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
919 {
920 	struct inpcb *inp = sotoinpcb(so);
921 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
922 	int error = 0;
923 	int s;
924 
925 	KASSERT(solocked(so));
926 	KASSERT(inp != NULL);
927 	KASSERT(nam != NULL);
928 
929 	s = splsoftnet();
930 	error = in_pcbbind(inp, sin, l);
931 	splx(s);
932 
933 	return error;
934 }
935 
936 static int
937 udp_listen(struct socket *so, struct lwp *l)
938 {
939 	KASSERT(solocked(so));
940 
941 	return EOPNOTSUPP;
942 }
943 
944 static int
945 udp_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
946 {
947 	struct inpcb *inp = sotoinpcb(so);
948 	int error = 0;
949 	int s;
950 
951 	KASSERT(solocked(so));
952 	KASSERT(inp != NULL);
953 	KASSERT(nam != NULL);
954 
955 	s = splsoftnet();
956 	error = in_pcbconnect(inp, (struct sockaddr_in *)nam, l);
957 	if (! error)
958 		soisconnected(so);
959 	splx(s);
960 	return error;
961 }
962 
963 static int
964 udp_connect2(struct socket *so, struct socket *so2)
965 {
966 	KASSERT(solocked(so));
967 
968 	return EOPNOTSUPP;
969 }
970 
971 static int
972 udp_disconnect(struct socket *so)
973 {
974 	struct inpcb *inp = sotoinpcb(so);
975 	int s;
976 
977 	KASSERT(solocked(so));
978 	KASSERT(inp != NULL);
979 
980 	s = splsoftnet();
981 	/*soisdisconnected(so);*/
982 	so->so_state &= ~SS_ISCONNECTED;	/* XXX */
983 	in_pcbdisconnect(inp);
984 	inp->inp_laddr = zeroin_addr;		/* XXX */
985 	in_pcbstate(inp, INP_BOUND);		/* XXX */
986 	splx(s);
987 
988 	return 0;
989 }
990 
991 static int
992 udp_shutdown(struct socket *so)
993 {
994 	int s;
995 
996 	KASSERT(solocked(so));
997 
998 	s = splsoftnet();
999 	socantsendmore(so);
1000 	splx(s);
1001 
1002 	return 0;
1003 }
1004 
1005 static int
1006 udp_abort(struct socket *so)
1007 {
1008 	KASSERT(solocked(so));
1009 
1010 	panic("udp_abort");
1011 
1012 	return EOPNOTSUPP;
1013 }
1014 
1015 static int
1016 udp_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
1017 {
1018 	return in_control(so, cmd, nam, ifp);
1019 }
1020 
1021 static int
1022 udp_stat(struct socket *so, struct stat *ub)
1023 {
1024 	KASSERT(solocked(so));
1025 
1026 	/* stat: don't bother with a blocksize. */
1027 	return 0;
1028 }
1029 
1030 static int
1031 udp_peeraddr(struct socket *so, struct sockaddr *nam)
1032 {
1033 	int s;
1034 
1035 	KASSERT(solocked(so));
1036 	KASSERT(sotoinpcb(so) != NULL);
1037 	KASSERT(nam != NULL);
1038 
1039 	s = splsoftnet();
1040 	in_setpeeraddr(sotoinpcb(so), (struct sockaddr_in *)nam);
1041 	splx(s);
1042 
1043 	return 0;
1044 }
1045 
1046 static int
1047 udp_sockaddr(struct socket *so, struct sockaddr *nam)
1048 {
1049 	int s;
1050 
1051 	KASSERT(solocked(so));
1052 	KASSERT(sotoinpcb(so) != NULL);
1053 	KASSERT(nam != NULL);
1054 
1055 	s = splsoftnet();
1056 	in_setsockaddr(sotoinpcb(so), (struct sockaddr_in *)nam);
1057 	splx(s);
1058 
1059 	return 0;
1060 }
1061 
1062 static int
1063 udp_rcvd(struct socket *so, int flags, struct lwp *l)
1064 {
1065 	KASSERT(solocked(so));
1066 
1067 	return EOPNOTSUPP;
1068 }
1069 
1070 static int
1071 udp_recvoob(struct socket *so, struct mbuf *m, int flags)
1072 {
1073 	KASSERT(solocked(so));
1074 
1075 	return EOPNOTSUPP;
1076 }
1077 
1078 static int
1079 udp_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
1080     struct mbuf *control, struct lwp *l)
1081 {
1082 	struct inpcb *inp = sotoinpcb(so);
1083 	int error = 0;
1084 	struct in_addr laddr;			/* XXX */
1085 	int s;
1086 
1087 	KASSERT(solocked(so));
1088 	KASSERT(inp != NULL);
1089 	KASSERT(m != NULL);
1090 
1091 	memset(&laddr, 0, sizeof laddr);
1092 
1093 	s = splsoftnet();
1094 	if (nam) {
1095 		laddr = inp->inp_laddr;		/* XXX */
1096 		if ((so->so_state & SS_ISCONNECTED) != 0) {
1097 			error = EISCONN;
1098 			goto die;
1099 		}
1100 		error = in_pcbconnect(inp, (struct sockaddr_in *)nam, l);
1101 		if (error)
1102 			goto die;
1103 	} else {
1104 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1105 			error = ENOTCONN;
1106 			goto die;
1107 		}
1108 	}
1109 	error = udp_output(m, inp, control, l);
1110 	m = NULL;
1111 	control = NULL;
1112 	if (nam) {
1113 		in_pcbdisconnect(inp);
1114 		inp->inp_laddr = laddr;		/* XXX */
1115 		in_pcbstate(inp, INP_BOUND);	/* XXX */
1116 	}
1117   die:
1118 	if (m != NULL)
1119 		m_freem(m);
1120 	if (control != NULL)
1121 		m_freem(control);
1122 
1123 	splx(s);
1124 	return error;
1125 }
1126 
1127 static int
1128 udp_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
1129 {
1130 	KASSERT(solocked(so));
1131 
1132 	m_freem(m);
1133 	m_freem(control);
1134 
1135 	return EOPNOTSUPP;
1136 }
1137 
1138 static int
1139 udp_purgeif(struct socket *so, struct ifnet *ifp)
1140 {
1141 	int s;
1142 
1143 	s = splsoftnet();
1144 	mutex_enter(softnet_lock);
1145 	in_pcbpurgeif0(&udbtable, ifp);
1146 #ifdef NET_MPSAFE
1147 	mutex_exit(softnet_lock);
1148 #endif
1149 	in_purgeif(ifp);
1150 #ifdef NET_MPSAFE
1151 	mutex_enter(softnet_lock);
1152 #endif
1153 	in_pcbpurgeif(&udbtable, ifp);
1154 	mutex_exit(softnet_lock);
1155 	splx(s);
1156 
1157 	return 0;
1158 }
1159 
1160 static int
1161 sysctl_net_inet_udp_stats(SYSCTLFN_ARGS)
1162 {
1163 
1164 	return (NETSTAT_SYSCTL(udpstat_percpu, UDP_NSTATS));
1165 }
1166 
1167 /*
1168  * Sysctl for udp variables.
1169  */
1170 static void
1171 sysctl_net_inet_udp_setup(struct sysctllog **clog)
1172 {
1173 
1174 	sysctl_createv(clog, 0, NULL, NULL,
1175 		       CTLFLAG_PERMANENT,
1176 		       CTLTYPE_NODE, "inet", NULL,
1177 		       NULL, 0, NULL, 0,
1178 		       CTL_NET, PF_INET, CTL_EOL);
1179 	sysctl_createv(clog, 0, NULL, NULL,
1180 		       CTLFLAG_PERMANENT,
1181 		       CTLTYPE_NODE, "udp",
1182 		       SYSCTL_DESCR("UDPv4 related settings"),
1183 		       NULL, 0, NULL, 0,
1184 		       CTL_NET, PF_INET, IPPROTO_UDP, CTL_EOL);
1185 
1186 	sysctl_createv(clog, 0, NULL, NULL,
1187 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1188 		       CTLTYPE_INT, "checksum",
1189 		       SYSCTL_DESCR("Compute UDP checksums"),
1190 		       NULL, 0, &udpcksum, 0,
1191 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_CHECKSUM,
1192 		       CTL_EOL);
1193 	sysctl_createv(clog, 0, NULL, NULL,
1194 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1195 		       CTLTYPE_INT, "sendspace",
1196 		       SYSCTL_DESCR("Default UDP send buffer size"),
1197 		       NULL, 0, &udp_sendspace, 0,
1198 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_SENDSPACE,
1199 		       CTL_EOL);
1200 	sysctl_createv(clog, 0, NULL, NULL,
1201 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1202 		       CTLTYPE_INT, "recvspace",
1203 		       SYSCTL_DESCR("Default UDP receive buffer size"),
1204 		       NULL, 0, &udp_recvspace, 0,
1205 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_RECVSPACE,
1206 		       CTL_EOL);
1207 	sysctl_createv(clog, 0, NULL, NULL,
1208 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1209 		       CTLTYPE_INT, "do_loopback_cksum",
1210 		       SYSCTL_DESCR("Perform UDP checksum on loopback"),
1211 		       NULL, 0, &udp_do_loopback_cksum, 0,
1212 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_LOOPBACKCKSUM,
1213 		       CTL_EOL);
1214 	sysctl_createv(clog, 0, NULL, NULL,
1215 		       CTLFLAG_PERMANENT,
1216 		       CTLTYPE_STRUCT, "pcblist",
1217 		       SYSCTL_DESCR("UDP protocol control block list"),
1218 		       sysctl_inpcblist, 0, &udbtable, 0,
1219 		       CTL_NET, PF_INET, IPPROTO_UDP, CTL_CREATE,
1220 		       CTL_EOL);
1221 	sysctl_createv(clog, 0, NULL, NULL,
1222 		       CTLFLAG_PERMANENT,
1223 		       CTLTYPE_STRUCT, "stats",
1224 		       SYSCTL_DESCR("UDP statistics"),
1225 		       sysctl_net_inet_udp_stats, 0, NULL, 0,
1226 		       CTL_NET, PF_INET, IPPROTO_UDP, UDPCTL_STATS,
1227 		       CTL_EOL);
1228 }
1229 #endif
1230 
1231 void
1232 udp_statinc(u_int stat)
1233 {
1234 
1235 	KASSERT(stat < UDP_NSTATS);
1236 	UDP_STATINC(stat);
1237 }
1238 
1239 #if defined(INET) && defined(IPSEC)
1240 /*
1241  * Handle ESP-in-UDP packets (RFC3948).
1242  *
1243  * We need to distinguish between ESP packets and IKE packets. We do so by
1244  * looking at the Non-ESP and Non-IKE markers.
1245  *
1246  * If IKE, we process the UDP packet as usual. Otherwise, ESP, we invoke
1247  * IPsec.
1248  *
1249  * Returns:
1250  *     1 if the packet was processed
1251  *     0 if normal UDP processing should take place
1252  *    -1 if an error occurred and m was freed
1253  */
1254 static int
1255 udp4_espinudp(struct mbuf **mp, int off, struct socket *so)
1256 {
1257 	size_t len;
1258 	uint8_t *data;
1259 	struct inpcb *inp;
1260 	size_t skip = 0;
1261 	size_t minlen;
1262 	size_t iphdrlen;
1263 	struct ip *ip;
1264 	struct m_tag *tag;
1265 	struct udphdr *udphdr;
1266 	u_int16_t sport, dport;
1267 	struct mbuf *m = *mp;
1268 
1269 	/*
1270 	 * Collapse the mbuf chain if the first mbuf is too short.
1271 	 * The longest case is: UDP + max(Non-ESP, Non-IKE) + ESP.
1272 	 */
1273 	minlen = off + 2 * sizeof(uint32_t) + sizeof(struct esp);
1274 	if (minlen > m->m_pkthdr.len)
1275 		minlen = m->m_pkthdr.len;
1276 
1277 	if (m->m_len < minlen) {
1278 		if ((*mp = m_pullup(m, minlen)) == NULL) {
1279 			return -1;
1280 		}
1281 		m = *mp;
1282 	}
1283 
1284 	len = m->m_len - off;
1285 	data = mtod(m, uint8_t *) + off;
1286 	inp = sotoinpcb(so);
1287 
1288 	/* Ignore keepalive packets. */
1289 	if ((len == 1) && (*data == 0xff)) {
1290 		m_freem(m);
1291 		*mp = NULL; /* avoid any further processing by caller */
1292 		return 1;
1293 	}
1294 
1295 	/* Handle Non-ESP marker (32bit). If zero, then IKE. */
1296 	if (inp->inp_flags & INP_ESPINUDP) {
1297 		uint32_t *marker = (uint32_t *)data;
1298 
1299 		if (len <= sizeof(uint32_t))
1300 			return 0;
1301 		if (marker[0] == 0)
1302 			return 0;
1303 
1304 		skip = sizeof(struct udphdr);
1305 	}
1306 
1307 	/* Handle Non-IKE marker (64bit). If non-zero, then IKE. */
1308 	if (inp->inp_flags & INP_ESPINUDP_NON_IKE) {
1309 		uint32_t *marker = (uint32_t *)data;
1310 
1311 		if (len <= 2 * sizeof(uint32_t) + sizeof(struct esp))
1312 			return 0;
1313 		if (marker[0] != 0 || marker[1] != 0)
1314 			return 0;
1315 
1316 		skip = sizeof(struct udphdr) + 2 * sizeof(uint32_t);
1317 	}
1318 
1319 	/*
1320 	 * Get the UDP ports. They are handled in network order
1321 	 * everywhere in the IPSEC_NAT_T code.
1322 	 */
1323 	udphdr = (struct udphdr *)((char *)data - skip);
1324 	sport = udphdr->uh_sport;
1325 	dport = udphdr->uh_dport;
1326 
1327 	/*
1328 	 * Remove the UDP header, plus a possible marker. IP header
1329 	 * length is iphdrlen.
1330 	 *
1331 	 * Before:
1332 	 *   <--- off --->
1333 	 *   +----+------+-----+
1334 	 *   | IP |  UDP | ESP |
1335 	 *   +----+------+-----+
1336 	 *        <-skip->
1337 	 * After:
1338 	 *          +----+-----+
1339 	 *          | IP | ESP |
1340 	 *          +----+-----+
1341 	 *   <-skip->
1342 	 */
1343 	iphdrlen = off - sizeof(struct udphdr);
1344 	memmove(mtod(m, char *) + skip, mtod(m, void *), iphdrlen);
1345 	m_adj(m, skip);
1346 
1347 	ip = mtod(m, struct ip *);
1348 	ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1349 	ip->ip_p = IPPROTO_ESP;
1350 
1351 	/*
1352 	 * We have modified the packet - it is now ESP, so we should not
1353 	 * return to UDP processing.
1354 	 *
1355 	 * Add a PACKET_TAG_IPSEC_NAT_T_PORTS tag to remember the source
1356 	 * UDP port. This is required if we want to select the right SPD
1357 	 * for multiple hosts behind same NAT.
1358 	 */
1359 	if ((tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1360 	    sizeof(sport) + sizeof(dport), M_DONTWAIT)) == NULL) {
1361 		m_freem(m);
1362 		return -1;
1363 	}
1364 	((u_int16_t *)(tag + 1))[0] = sport;
1365 	((u_int16_t *)(tag + 1))[1] = dport;
1366 	m_tag_prepend(m, tag);
1367 
1368 	if (ipsec_used)
1369 		ipsec4_common_input(m, iphdrlen, IPPROTO_ESP);
1370 	else
1371 		m_freem(m);
1372 
1373 	/* We handled it, it shouldn't be handled by UDP */
1374 	*mp = NULL; /* avoid free by caller ... */
1375 	return 1;
1376 }
1377 #endif
1378 
1379 PR_WRAP_USRREQS(udp)
1380 #define	udp_attach	udp_attach_wrapper
1381 #define	udp_detach	udp_detach_wrapper
1382 #define	udp_accept	udp_accept_wrapper
1383 #define	udp_bind	udp_bind_wrapper
1384 #define	udp_listen	udp_listen_wrapper
1385 #define	udp_connect	udp_connect_wrapper
1386 #define	udp_connect2	udp_connect2_wrapper
1387 #define	udp_disconnect	udp_disconnect_wrapper
1388 #define	udp_shutdown	udp_shutdown_wrapper
1389 #define	udp_abort	udp_abort_wrapper
1390 #define	udp_ioctl	udp_ioctl_wrapper
1391 #define	udp_stat	udp_stat_wrapper
1392 #define	udp_peeraddr	udp_peeraddr_wrapper
1393 #define	udp_sockaddr	udp_sockaddr_wrapper
1394 #define	udp_rcvd	udp_rcvd_wrapper
1395 #define	udp_recvoob	udp_recvoob_wrapper
1396 #define	udp_send	udp_send_wrapper
1397 #define	udp_sendoob	udp_sendoob_wrapper
1398 #define	udp_purgeif	udp_purgeif_wrapper
1399 
1400 const struct pr_usrreqs udp_usrreqs = {
1401 	.pr_attach	= udp_attach,
1402 	.pr_detach	= udp_detach,
1403 	.pr_accept	= udp_accept,
1404 	.pr_bind	= udp_bind,
1405 	.pr_listen	= udp_listen,
1406 	.pr_connect	= udp_connect,
1407 	.pr_connect2	= udp_connect2,
1408 	.pr_disconnect	= udp_disconnect,
1409 	.pr_shutdown	= udp_shutdown,
1410 	.pr_abort	= udp_abort,
1411 	.pr_ioctl	= udp_ioctl,
1412 	.pr_stat	= udp_stat,
1413 	.pr_peeraddr	= udp_peeraddr,
1414 	.pr_sockaddr	= udp_sockaddr,
1415 	.pr_rcvd	= udp_rcvd,
1416 	.pr_recvoob	= udp_recvoob,
1417 	.pr_send	= udp_send,
1418 	.pr_sendoob	= udp_sendoob,
1419 	.pr_purgeif	= udp_purgeif,
1420 };
1421