xref: /netbsd/sys/netinet/udp_usrreq.c (revision c4a72b64)
1 /*	$NetBSD: udp_usrreq.c,v 1.96 2002/08/14 00:23:36 itojun 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. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *	This product includes software developed by the University of
47  *	California, Berkeley and its contributors.
48  * 4. Neither the name of the University nor the names of its contributors
49  *    may be used to endorse or promote products derived from this software
50  *    without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  *
64  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
65  */
66 
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: udp_usrreq.c,v 1.96 2002/08/14 00:23:36 itojun Exp $");
69 
70 #include "opt_inet.h"
71 #include "opt_ipsec.h"
72 #include "opt_inet_csum.h"
73 #include "opt_ipkdb.h"
74 
75 #include <sys/param.h>
76 #include <sys/malloc.h>
77 #include <sys/mbuf.h>
78 #include <sys/protosw.h>
79 #include <sys/socket.h>
80 #include <sys/socketvar.h>
81 #include <sys/errno.h>
82 #include <sys/stat.h>
83 #include <sys/systm.h>
84 #include <sys/proc.h>
85 #include <sys/domain.h>
86 #include <sys/sysctl.h>
87 
88 #include <net/if.h>
89 #include <net/route.h>
90 
91 #include <netinet/in.h>
92 #include <netinet/in_systm.h>
93 #include <netinet/in_var.h>
94 #include <netinet/ip.h>
95 #include <netinet/in_pcb.h>
96 #include <netinet/ip_var.h>
97 #include <netinet/ip_icmp.h>
98 #include <netinet/udp.h>
99 #include <netinet/udp_var.h>
100 
101 #ifdef INET6
102 #include <netinet/ip6.h>
103 #include <netinet/icmp6.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet6/in6_pcb.h>
106 #include <netinet6/udp6_var.h>
107 #endif
108 
109 #ifdef PULLDOWN_TEST
110 #ifndef INET6
111 /* always need ip6.h for IP6_EXTHDR_GET */
112 #include <netinet/ip6.h>
113 #endif
114 #endif
115 
116 #include "faith.h"
117 #if defined(NFAITH) && NFAITH > 0
118 #include <net/if_faith.h>
119 #endif
120 
121 #include <machine/stdarg.h>
122 
123 #ifdef IPSEC
124 #include <netinet6/ipsec.h>
125 #include <netkey/key.h>
126 #endif /*IPSEC*/
127 
128 #ifdef IPKDB
129 #include <ipkdb/ipkdb.h>
130 #endif
131 
132 /*
133  * UDP protocol implementation.
134  * Per RFC 768, August, 1980.
135  */
136 #ifndef	COMPAT_42
137 int	udpcksum = 1;
138 #else
139 int	udpcksum = 0;		/* XXX */
140 #endif
141 
142 struct	inpcbtable udbtable;
143 struct	udpstat udpstat;
144 
145 #ifdef INET
146 static void udp4_sendup __P((struct mbuf *, int, struct sockaddr *,
147 	struct socket *));
148 static int udp4_realinput __P((struct sockaddr_in *, struct sockaddr_in *,
149 	struct mbuf *, int));
150 #endif
151 #ifdef INET6
152 static void udp6_sendup __P((struct mbuf *, int, struct sockaddr *,
153 	struct socket *));
154 static int udp6_realinput __P((int, struct sockaddr_in6 *,
155 	struct sockaddr_in6 *, struct mbuf *, int));
156 #endif
157 #ifdef INET
158 static	void udp_notify __P((struct inpcb *, int));
159 #endif
160 
161 #ifndef UDBHASHSIZE
162 #define	UDBHASHSIZE	128
163 #endif
164 int	udbhashsize = UDBHASHSIZE;
165 
166 #ifdef UDP_CSUM_COUNTERS
167 #include <sys/device.h>
168 
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 #define	UDP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
179 
180 #else
181 
182 #define	UDP_CSUM_COUNTER_INCR(ev)	/* nothing */
183 
184 #endif /* UDP_CSUM_COUNTERS */
185 
186 void
187 udp_init()
188 {
189 
190 #ifdef INET
191 	in_pcbinit(&udbtable, udbhashsize, udbhashsize);
192 #endif
193 
194 #ifdef UDP_CSUM_COUNTERS
195 	evcnt_attach_static(&udp_hwcsum_bad);
196 	evcnt_attach_static(&udp_hwcsum_ok);
197 	evcnt_attach_static(&udp_hwcsum_data);
198 	evcnt_attach_static(&udp_swcsum);
199 #endif /* UDP_CSUM_COUNTERS */
200 }
201 
202 #ifdef INET
203 void
204 #if __STDC__
205 udp_input(struct mbuf *m, ...)
206 #else
207 udp_input(m, va_alist)
208 	struct mbuf *m;
209 	va_dcl
210 #endif
211 {
212 	va_list ap;
213 	struct sockaddr_in src, dst;
214 	struct ip *ip;
215 	struct udphdr *uh;
216 	int iphlen, proto;
217 	int len;
218 	int n;
219 	u_int16_t ip_len;
220 
221 	va_start(ap, m);
222 	iphlen = va_arg(ap, int);
223 	proto = va_arg(ap, int);
224 	va_end(ap);
225 
226 	udpstat.udps_ipackets++;
227 
228 #ifndef PULLDOWN_TEST
229 	/*
230 	 * Strip IP options, if any; should skip this,
231 	 * make available to user, and use on returned packets,
232 	 * but we don't yet have a way to check the checksum
233 	 * with options still present.
234 	 */
235 	if (iphlen > sizeof (struct ip)) {
236 		ip_stripoptions(m, (struct mbuf *)0);
237 		iphlen = sizeof(struct ip);
238 	}
239 #else
240 	/*
241 	 * we may enable the above code if we save and pass IPv4 options
242 	 * to the userland.
243 	 */
244 #endif
245 
246 	/*
247 	 * Get IP and UDP header together in first mbuf.
248 	 */
249 	ip = mtod(m, struct ip *);
250 #ifndef PULLDOWN_TEST
251 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
252 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
253 			udpstat.udps_hdrops++;
254 			return;
255 		}
256 		ip = mtod(m, struct ip *);
257 	}
258 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
259 #else
260 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
261 	if (uh == NULL) {
262 		udpstat.udps_hdrops++;
263 		return;
264 	}
265 #endif
266 	KASSERT(UDP_HDR_ALIGNED_P(uh));
267 
268 	/* destination port of 0 is illegal, based on RFC768. */
269 	if (uh->uh_dport == 0)
270 		goto bad;
271 
272 	/*
273 	 * Make mbuf data length reflect UDP length.
274 	 * If not enough data to reflect UDP length, drop.
275 	 */
276 	ip_len = ntohs(ip->ip_len);
277 	len = ntohs((u_int16_t)uh->uh_ulen);
278 	if (ip_len != iphlen + len) {
279 		if (ip_len < iphlen + len || len < sizeof(struct udphdr)) {
280 			udpstat.udps_badlen++;
281 			goto bad;
282 		}
283 		m_adj(m, iphlen + len - ip_len);
284 	}
285 
286 	/*
287 	 * Checksum extended UDP header and data.
288 	 */
289 	if (uh->uh_sum) {
290 		switch (m->m_pkthdr.csum_flags &
291 			((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_UDPv4) |
292 			 M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
293 		case M_CSUM_UDPv4|M_CSUM_TCP_UDP_BAD:
294 			UDP_CSUM_COUNTER_INCR(&udp_hwcsum_bad);
295 			goto badcsum;
296 
297 		case M_CSUM_UDPv4|M_CSUM_DATA:
298 			UDP_CSUM_COUNTER_INCR(&udp_hwcsum_data);
299 			if ((m->m_pkthdr.csum_data ^ 0xffff) != 0)
300 				goto badcsum;
301 			break;
302 
303 		case M_CSUM_UDPv4:
304 			/* Checksum was okay. */
305 			UDP_CSUM_COUNTER_INCR(&udp_hwcsum_ok);
306 			break;
307 
308 		default:
309 			/* Need to compute it ourselves. */
310 			UDP_CSUM_COUNTER_INCR(&udp_swcsum);
311 			if (in4_cksum(m, IPPROTO_UDP, iphlen, len) != 0)
312 				goto badcsum;
313 			break;
314 		}
315 	}
316 
317 	/* construct source and dst sockaddrs. */
318 	bzero(&src, sizeof(src));
319 	src.sin_family = AF_INET;
320 	src.sin_len = sizeof(struct sockaddr_in);
321 	bcopy(&ip->ip_src, &src.sin_addr, sizeof(src.sin_addr));
322 	src.sin_port = uh->uh_sport;
323 	bzero(&dst, sizeof(dst));
324 	dst.sin_family = AF_INET;
325 	dst.sin_len = sizeof(struct sockaddr_in);
326 	bcopy(&ip->ip_dst, &dst.sin_addr, sizeof(dst.sin_addr));
327 	dst.sin_port = uh->uh_dport;
328 
329 	n = udp4_realinput(&src, &dst, m, iphlen);
330 #ifdef INET6
331 	if (IN_MULTICAST(ip->ip_dst.s_addr) || n == 0) {
332 		struct sockaddr_in6 src6, dst6;
333 
334 		bzero(&src6, sizeof(src6));
335 		src6.sin6_family = AF_INET6;
336 		src6.sin6_len = sizeof(struct sockaddr_in6);
337 		src6.sin6_addr.s6_addr[10] = src6.sin6_addr.s6_addr[11] = 0xff;
338 		bcopy(&ip->ip_src, &src6.sin6_addr.s6_addr[12],
339 			sizeof(ip->ip_src));
340 		src6.sin6_port = uh->uh_sport;
341 		bzero(&dst6, sizeof(dst6));
342 		dst6.sin6_family = AF_INET6;
343 		dst6.sin6_len = sizeof(struct sockaddr_in6);
344 		dst6.sin6_addr.s6_addr[10] = dst6.sin6_addr.s6_addr[11] = 0xff;
345 		bcopy(&ip->ip_dst, &dst6.sin6_addr.s6_addr[12],
346 			sizeof(ip->ip_dst));
347 		dst6.sin6_port = uh->uh_dport;
348 
349 		n += udp6_realinput(AF_INET, &src6, &dst6, m, iphlen);
350 	}
351 #endif
352 
353 	if (n == 0) {
354 		if (m->m_flags & (M_BCAST | M_MCAST)) {
355 			udpstat.udps_noportbcast++;
356 			goto bad;
357 		}
358 		udpstat.udps_noport++;
359 #ifdef IPKDB
360 		if (checkipkdb(&ip->ip_src, uh->uh_sport, uh->uh_dport,
361 				m, iphlen + sizeof(struct udphdr),
362 				m->m_pkthdr.len - iphlen - sizeof(struct udphdr))) {
363 			/*
364 			 * It was a debugger connect packet,
365 			 * just drop it now
366 			 */
367 			goto bad;
368 		}
369 #endif
370 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
371 		m = NULL;
372 	}
373 
374 bad:
375 	if (m)
376 		m_freem(m);
377 	return;
378 
379 badcsum:
380 	m_freem(m);
381 	udpstat.udps_badsum++;
382 }
383 #endif
384 
385 #ifdef INET6
386 int
387 udp6_input(mp, offp, proto)
388 	struct mbuf **mp;
389 	int *offp, proto;
390 {
391 	struct mbuf *m = *mp;
392 	int off = *offp;
393 	struct sockaddr_in6 src, dst;
394 	struct ip6_hdr *ip6;
395 	struct udphdr *uh;
396 	u_int32_t plen, ulen;
397 
398 #ifndef PULLDOWN_TEST
399 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
400 #endif
401 	ip6 = mtod(m, struct ip6_hdr *);
402 
403 #if defined(NFAITH) && 0 < NFAITH
404 	if (faithprefix(&ip6->ip6_dst)) {
405 		/* send icmp6 host unreach? */
406 		m_freem(m);
407 		return IPPROTO_DONE;
408 	}
409 #endif
410 
411 	udp6stat.udp6s_ipackets++;
412 
413 	/* check for jumbogram is done in ip6_input.  we can trust pkthdr.len */
414 	plen = m->m_pkthdr.len - off;
415 #ifndef PULLDOWN_TEST
416 	uh = (struct udphdr *)((caddr_t)ip6 + off);
417 #else
418 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(struct udphdr));
419 	if (uh == NULL) {
420 		ip6stat.ip6s_tooshort++;
421 		return IPPROTO_DONE;
422 	}
423 #endif
424 	KASSERT(UDP_HDR_ALIGNED_P(uh));
425 	ulen = ntohs((u_short)uh->uh_ulen);
426 	/*
427 	 * RFC2675 section 4: jumbograms will have 0 in the UDP header field,
428 	 * iff payload length > 0xffff.
429 	 */
430 	if (ulen == 0 && plen > 0xffff)
431 		ulen = plen;
432 
433 	if (plen != ulen) {
434 		udp6stat.udp6s_badlen++;
435 		goto bad;
436 	}
437 
438 	/* destination port of 0 is illegal, based on RFC768. */
439 	if (uh->uh_dport == 0)
440 		goto bad;
441 
442 	/* Be proactive about malicious use of IPv4 mapped address */
443 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
444 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
445 		/* XXX stat */
446 		goto bad;
447 	}
448 
449 	/*
450 	 * Checksum extended UDP header and data.
451 	 */
452 	if (uh->uh_sum == 0)
453 		udp6stat.udp6s_nosum++;
454 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
455 		udp6stat.udp6s_badsum++;
456 		goto bad;
457 	}
458 
459 	/*
460 	 * Construct source and dst sockaddrs.
461 	 * Note that ifindex (s6_addr16[1]) is already filled.
462 	 */
463 	bzero(&src, sizeof(src));
464 	src.sin6_family = AF_INET6;
465 	src.sin6_len = sizeof(struct sockaddr_in6);
466 	/* KAME hack: recover scopeid */
467 	(void)in6_recoverscope(&src, &ip6->ip6_src, m->m_pkthdr.rcvif);
468 	src.sin6_port = uh->uh_sport;
469 	bzero(&dst, sizeof(dst));
470 	dst.sin6_family = AF_INET6;
471 	dst.sin6_len = sizeof(struct sockaddr_in6);
472 	/* KAME hack: recover scopeid */
473 	(void)in6_recoverscope(&dst, &ip6->ip6_dst, m->m_pkthdr.rcvif);
474 	dst.sin6_port = uh->uh_dport;
475 
476 	if (udp6_realinput(AF_INET6, &src, &dst, m, off) == 0) {
477 		if (m->m_flags & M_MCAST) {
478 			udp6stat.udp6s_noportmcast++;
479 			goto bad;
480 		}
481 		udp6stat.udp6s_noport++;
482 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
483 		m = NULL;
484 	}
485 
486 bad:
487 	if (m)
488 		m_freem(m);
489 	return IPPROTO_DONE;
490 }
491 #endif
492 
493 #ifdef INET
494 static void
495 udp4_sendup(m, off, src, so)
496 	struct mbuf *m;
497 	int off;	/* offset of data portion */
498 	struct sockaddr *src;
499 	struct socket *so;
500 {
501 	struct mbuf *opts = NULL;
502 	struct mbuf *n;
503 	struct inpcb *inp = NULL;
504 #ifdef INET6
505 	struct in6pcb *in6p = NULL;
506 #endif
507 
508 	if (!so)
509 		return;
510 	switch (so->so_proto->pr_domain->dom_family) {
511 	case AF_INET:
512 		inp = sotoinpcb(so);
513 		break;
514 #ifdef INET6
515 	case AF_INET6:
516 		in6p = sotoin6pcb(so);
517 		break;
518 #endif
519 	default:
520 		return;
521 	}
522 
523 #ifdef IPSEC
524 	/* check AH/ESP integrity. */
525 	if (so != NULL && ipsec4_in_reject_so(m, so)) {
526 		ipsecstat.in_polvio++;
527 		return;
528 	}
529 #endif /*IPSEC*/
530 
531 	if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
532 		if (inp && (inp->inp_flags & INP_CONTROLOPTS
533 			 || so->so_options & SO_TIMESTAMP)) {
534 			struct ip *ip = mtod(n, struct ip *);
535 			ip_savecontrol(inp, &opts, ip, n);
536 		}
537 
538 		m_adj(n, off);
539 		if (sbappendaddr(&so->so_rcv, src, n,
540 				opts) == 0) {
541 			m_freem(n);
542 			if (opts)
543 				m_freem(opts);
544 			udpstat.udps_fullsock++;
545 		} else
546 			sorwakeup(so);
547 	}
548 }
549 #endif
550 
551 #ifdef INET6
552 static void
553 udp6_sendup(m, off, src, so)
554 	struct mbuf *m;
555 	int off;	/* offset of data portion */
556 	struct sockaddr *src;
557 	struct socket *so;
558 {
559 	struct mbuf *opts = NULL;
560 	struct mbuf *n;
561 	struct in6pcb *in6p = NULL;
562 
563 	if (!so)
564 		return;
565 	if (so->so_proto->pr_domain->dom_family != AF_INET6)
566 		return;
567 	in6p = sotoin6pcb(so);
568 
569 #ifdef IPSEC
570 	/* check AH/ESP integrity. */
571 	if (so != NULL && ipsec6_in_reject_so(m, so)) {
572 		ipsec6stat.in_polvio++;
573 		return;
574 	}
575 #endif /*IPSEC*/
576 
577 	if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
578 		if (in6p && (in6p->in6p_flags & IN6P_CONTROLOPTS
579 			  || in6p->in6p_socket->so_options & SO_TIMESTAMP)) {
580 			struct ip6_hdr *ip6 = mtod(n, struct ip6_hdr *);
581 			ip6_savecontrol(in6p, &opts, ip6, n);
582 		}
583 
584 		m_adj(n, off);
585 		if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
586 			m_freem(n);
587 			if (opts)
588 				m_freem(opts);
589 			udp6stat.udp6s_fullsock++;
590 		} else
591 			sorwakeup(so);
592 	}
593 }
594 #endif
595 
596 #ifdef INET
597 static int
598 udp4_realinput(src, dst, m, off)
599 	struct sockaddr_in *src;
600 	struct sockaddr_in *dst;
601 	struct mbuf *m;
602 	int off;	/* offset of udphdr */
603 {
604 	u_int16_t *sport, *dport;
605 	int rcvcnt;
606 	struct in_addr *src4, *dst4;
607 	struct inpcb *inp;
608 
609 	rcvcnt = 0;
610 	off += sizeof(struct udphdr);	/* now, offset of payload */
611 
612 	if (src->sin_family != AF_INET || dst->sin_family != AF_INET)
613 		goto bad;
614 
615 	src4 = &src->sin_addr;
616 	sport = &src->sin_port;
617 	dst4 = &dst->sin_addr;
618 	dport = &dst->sin_port;
619 
620 	if (IN_MULTICAST(dst4->s_addr) ||
621 	    in_broadcast(*dst4, m->m_pkthdr.rcvif)) {
622 		struct inpcb *last;
623 		/*
624 		 * Deliver a multicast or broadcast datagram to *all* sockets
625 		 * for which the local and remote addresses and ports match
626 		 * those of the incoming datagram.  This allows more than
627 		 * one process to receive multi/broadcasts on the same port.
628 		 * (This really ought to be done for unicast datagrams as
629 		 * well, but that would cause problems with existing
630 		 * applications that open both address-specific sockets and
631 		 * a wildcard socket listening to the same port -- they would
632 		 * end up receiving duplicates of every unicast datagram.
633 		 * Those applications open the multiple sockets to overcome an
634 		 * inadequacy of the UDP socket interface, but for backwards
635 		 * compatibility we avoid the problem here rather than
636 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
637 		 */
638 
639 		/*
640 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
641 		 * we need udpiphdr for IPsec processing so we do that later.
642 		 */
643 		/*
644 		 * Locate pcb(s) for datagram.
645 		 */
646 		CIRCLEQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
647 			if (inp->inp_lport != *dport)
648 				continue;
649 			if (!in_nullhost(inp->inp_laddr)) {
650 				if (!in_hosteq(inp->inp_laddr, *dst4))
651 					continue;
652 			}
653 			if (!in_nullhost(inp->inp_faddr)) {
654 				if (!in_hosteq(inp->inp_faddr, *src4) ||
655 				    inp->inp_fport != *sport)
656 					continue;
657 			}
658 
659 			last = inp;
660 			udp4_sendup(m, off, (struct sockaddr *)src,
661 				inp->inp_socket);
662 			rcvcnt++;
663 
664 			/*
665 			 * Don't look for additional matches if this one does
666 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
667 			 * socket options set.  This heuristic avoids searching
668 			 * through all pcbs in the common case of a non-shared
669 			 * port.  It assumes that an application will never
670 			 * clear these options after setting them.
671 			 */
672 			if ((inp->inp_socket->so_options &
673 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
674 				break;
675 		}
676 	} else {
677 		/*
678 		 * Locate pcb for datagram.
679 		 */
680 		inp = in_pcblookup_connect(&udbtable, *src4, *sport, *dst4, *dport);
681 		if (inp == 0) {
682 			++udpstat.udps_pcbhashmiss;
683 			inp = in_pcblookup_bind(&udbtable, *dst4, *dport);
684 			if (inp == 0)
685 				return rcvcnt;
686 		}
687 
688 		udp4_sendup(m, off, (struct sockaddr *)src, inp->inp_socket);
689 		rcvcnt++;
690 	}
691 
692 bad:
693 	return rcvcnt;
694 }
695 #endif
696 
697 #ifdef INET6
698 static int
699 udp6_realinput(af, src, dst, m, off)
700 	int af;		/* af on packet */
701 	struct sockaddr_in6 *src;
702 	struct sockaddr_in6 *dst;
703 	struct mbuf *m;
704 	int off;	/* offset of udphdr */
705 {
706 	u_int16_t sport, dport;
707 	int rcvcnt;
708 	struct in6_addr src6, dst6;
709 	const struct in_addr *dst4;
710 	struct in6pcb *in6p;
711 
712 	rcvcnt = 0;
713 	off += sizeof(struct udphdr);	/* now, offset of payload */
714 
715 	if (af != AF_INET && af != AF_INET6)
716 		goto bad;
717 	if (src->sin6_family != AF_INET6 || dst->sin6_family != AF_INET6)
718 		goto bad;
719 
720 	in6_embedscope(&src6, src, NULL, NULL);
721 	sport = src->sin6_port;
722 	in6_embedscope(&dst6, dst, NULL, NULL);
723 	dport = dst->sin6_port;
724 	dst4 = (struct in_addr *)&dst->sin6_addr.s6_addr[12];
725 
726 	if (IN6_IS_ADDR_MULTICAST(&dst6) ||
727 	    (af == AF_INET && IN_MULTICAST(dst4->s_addr))) {
728 		struct in6pcb *last;
729 		/*
730 		 * Deliver a multicast or broadcast datagram to *all* sockets
731 		 * for which the local and remote addresses and ports match
732 		 * those of the incoming datagram.  This allows more than
733 		 * one process to receive multi/broadcasts on the same port.
734 		 * (This really ought to be done for unicast datagrams as
735 		 * well, but that would cause problems with existing
736 		 * applications that open both address-specific sockets and
737 		 * a wildcard socket listening to the same port -- they would
738 		 * end up receiving duplicates of every unicast datagram.
739 		 * Those applications open the multiple sockets to overcome an
740 		 * inadequacy of the UDP socket interface, but for backwards
741 		 * compatibility we avoid the problem here rather than
742 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
743 		 */
744 
745 		/*
746 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
747 		 * we need udpiphdr for IPsec processing so we do that later.
748 		 */
749 		/*
750 		 * Locate pcb(s) for datagram.
751 		 */
752 		for (in6p = udb6.in6p_next; in6p != &udb6;
753 		     in6p = in6p->in6p_next) {
754 			if (in6p->in6p_lport != dport)
755 				continue;
756 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
757 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &dst6))
758 					continue;
759 			} else {
760 				if (IN6_IS_ADDR_V4MAPPED(&dst6) &&
761 				    (in6p->in6p_flags & IN6P_IPV6_V6ONLY))
762 					continue;
763 			}
764 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
765 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
766 				    &src6) || in6p->in6p_fport != sport)
767 					continue;
768 			} else {
769 				if (IN6_IS_ADDR_V4MAPPED(&src6) &&
770 				    (in6p->in6p_flags & IN6P_IPV6_V6ONLY))
771 					continue;
772 			}
773 
774 			last = in6p;
775 			udp6_sendup(m, off, (struct sockaddr *)src,
776 				in6p->in6p_socket);
777 			rcvcnt++;
778 
779 			/*
780 			 * Don't look for additional matches if this one does
781 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
782 			 * socket options set.  This heuristic avoids searching
783 			 * through all pcbs in the common case of a non-shared
784 			 * port.  It assumes that an application will never
785 			 * clear these options after setting them.
786 			 */
787 			if ((in6p->in6p_socket->so_options &
788 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
789 				break;
790 		}
791 	} else {
792 		/*
793 		 * Locate pcb for datagram.
794 		 */
795 		in6p = in6_pcblookup_connect(&udb6, &src6, sport,
796 		    &dst6, dport, 0);
797 		if (in6p == 0) {
798 			++udpstat.udps_pcbhashmiss;
799 			in6p = in6_pcblookup_bind(&udb6, &dst6, dport, 0);
800 			if (in6p == 0)
801 				return rcvcnt;
802 		}
803 
804 		udp6_sendup(m, off, (struct sockaddr *)src, in6p->in6p_socket);
805 		rcvcnt++;
806 	}
807 
808 bad:
809 	return rcvcnt;
810 }
811 #endif
812 
813 #ifdef INET
814 /*
815  * Notify a udp user of an asynchronous error;
816  * just wake up so that he can collect error status.
817  */
818 static void
819 udp_notify(inp, errno)
820 	struct inpcb *inp;
821 	int errno;
822 {
823 
824 	inp->inp_socket->so_error = errno;
825 	sorwakeup(inp->inp_socket);
826 	sowwakeup(inp->inp_socket);
827 }
828 
829 void *
830 udp_ctlinput(cmd, sa, v)
831 	int cmd;
832 	struct sockaddr *sa;
833 	void *v;
834 {
835 	struct ip *ip = v;
836 	struct udphdr *uh;
837 	void (*notify) __P((struct inpcb *, int)) = udp_notify;
838 	int errno;
839 
840 	if (sa->sa_family != AF_INET
841 	 || sa->sa_len != sizeof(struct sockaddr_in))
842 		return NULL;
843 	if ((unsigned)cmd >= PRC_NCMDS)
844 		return NULL;
845 	errno = inetctlerrmap[cmd];
846 	if (PRC_IS_REDIRECT(cmd))
847 		notify = in_rtchange, ip = 0;
848 	else if (cmd == PRC_HOSTDEAD)
849 		ip = 0;
850 	else if (errno == 0)
851 		return NULL;
852 	if (ip) {
853 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
854 		in_pcbnotify(&udbtable, satosin(sa)->sin_addr, uh->uh_dport,
855 		    ip->ip_src, uh->uh_sport, errno, notify);
856 
857 		/* XXX mapped address case */
858 	} else
859 		in_pcbnotifyall(&udbtable, satosin(sa)->sin_addr, errno,
860 		    notify);
861 	return NULL;
862 }
863 
864 int
865 #if __STDC__
866 udp_output(struct mbuf *m, ...)
867 #else
868 udp_output(m, va_alist)
869 	struct mbuf *m;
870 	va_dcl
871 #endif
872 {
873 	struct inpcb *inp;
874 	struct udpiphdr *ui;
875 	int len = m->m_pkthdr.len;
876 	int error = 0;
877 	va_list ap;
878 
879 	va_start(ap, m);
880 	inp = va_arg(ap, struct inpcb *);
881 	va_end(ap);
882 
883 	/*
884 	 * Calculate data length and get a mbuf
885 	 * for UDP and IP headers.
886 	 */
887 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
888 	if (m == 0) {
889 		error = ENOBUFS;
890 		goto release;
891 	}
892 
893 	/*
894 	 * Compute the packet length of the IP header, and
895 	 * punt if the length looks bogus.
896 	 */
897 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
898 		error = EMSGSIZE;
899 		goto release;
900 	}
901 
902 	/*
903 	 * Fill in mbuf with extended UDP header
904 	 * and addresses and length put into network format.
905 	 */
906 	ui = mtod(m, struct udpiphdr *);
907 	ui->ui_pr = IPPROTO_UDP;
908 	ui->ui_src = inp->inp_laddr;
909 	ui->ui_dst = inp->inp_faddr;
910 	ui->ui_sport = inp->inp_lport;
911 	ui->ui_dport = inp->inp_fport;
912 	ui->ui_ulen = htons((u_int16_t)len + sizeof(struct udphdr));
913 
914 	/*
915 	 * Set up checksum and output datagram.
916 	 */
917 	if (udpcksum) {
918 		/*
919 		 * XXX Cache pseudo-header checksum part for
920 		 * XXX "connected" UDP sockets.
921 		 */
922 		ui->ui_sum = in_cksum_phdr(ui->ui_src.s_addr,
923 		    ui->ui_dst.s_addr, htons((u_int16_t)len +
924 		    sizeof(struct udphdr) + IPPROTO_UDP));
925 		m->m_pkthdr.csum_flags = M_CSUM_UDPv4;
926 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
927 	} else
928 		ui->ui_sum = 0;
929 	((struct ip *)ui)->ip_len = htons(sizeof (struct udpiphdr) + len);
930 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;	/* XXX */
931 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;	/* XXX */
932 	udpstat.udps_opackets++;
933 
934 #ifdef IPSEC
935 	if (ipsec_setsocket(m, inp->inp_socket) != 0) {
936 		error = ENOBUFS;
937 		goto release;
938 	}
939 #endif /*IPSEC*/
940 
941 	return (ip_output(m, inp->inp_options, &inp->inp_route,
942 	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST),
943 	    inp->inp_moptions));
944 
945 release:
946 	m_freem(m);
947 	return (error);
948 }
949 
950 int	udp_sendspace = 9216;		/* really max datagram size */
951 int	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
952 					/* 40 1K datagrams */
953 
954 /*ARGSUSED*/
955 int
956 udp_usrreq(so, req, m, nam, control, p)
957 	struct socket *so;
958 	int req;
959 	struct mbuf *m, *nam, *control;
960 	struct proc *p;
961 {
962 	struct inpcb *inp;
963 	int s;
964 	int error = 0;
965 
966 	if (req == PRU_CONTROL)
967 		return (in_control(so, (long)m, (caddr_t)nam,
968 		    (struct ifnet *)control, p));
969 
970 	if (req == PRU_PURGEIF) {
971 		in_pcbpurgeif0(&udbtable, (struct ifnet *)control);
972 		in_purgeif((struct ifnet *)control);
973 		in_pcbpurgeif(&udbtable, (struct ifnet *)control);
974 		return (0);
975 	}
976 
977 	s = splsoftnet();
978 	inp = sotoinpcb(so);
979 #ifdef DIAGNOSTIC
980 	if (req != PRU_SEND && req != PRU_SENDOOB && control)
981 		panic("udp_usrreq: unexpected control mbuf");
982 #endif
983 	if (inp == 0 && req != PRU_ATTACH) {
984 		error = EINVAL;
985 		goto release;
986 	}
987 
988 	/*
989 	 * Note: need to block udp_input while changing
990 	 * the udp pcb queue and/or pcb addresses.
991 	 */
992 	switch (req) {
993 
994 	case PRU_ATTACH:
995 		if (inp != 0) {
996 			error = EISCONN;
997 			break;
998 		}
999 		if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
1000 			error = soreserve(so, udp_sendspace, udp_recvspace);
1001 			if (error)
1002 				break;
1003 		}
1004 		error = in_pcballoc(so, &udbtable);
1005 		if (error)
1006 			break;
1007 		inp = sotoinpcb(so);
1008 		inp->inp_ip.ip_ttl = ip_defttl;
1009 		break;
1010 
1011 	case PRU_DETACH:
1012 		in_pcbdetach(inp);
1013 		break;
1014 
1015 	case PRU_BIND:
1016 		error = in_pcbbind(inp, nam, p);
1017 		break;
1018 
1019 	case PRU_LISTEN:
1020 		error = EOPNOTSUPP;
1021 		break;
1022 
1023 	case PRU_CONNECT:
1024 		error = in_pcbconnect(inp, nam);
1025 		if (error)
1026 			break;
1027 		soisconnected(so);
1028 		break;
1029 
1030 	case PRU_CONNECT2:
1031 		error = EOPNOTSUPP;
1032 		break;
1033 
1034 	case PRU_DISCONNECT:
1035 		/*soisdisconnected(so);*/
1036 		so->so_state &= ~SS_ISCONNECTED;	/* XXX */
1037 		in_pcbdisconnect(inp);
1038 		inp->inp_laddr = zeroin_addr;		/* XXX */
1039 		in_pcbstate(inp, INP_BOUND);		/* XXX */
1040 		break;
1041 
1042 	case PRU_SHUTDOWN:
1043 		socantsendmore(so);
1044 		break;
1045 
1046 	case PRU_RCVD:
1047 		error = EOPNOTSUPP;
1048 		break;
1049 
1050 	case PRU_SEND:
1051 		if (control && control->m_len) {
1052 			m_freem(control);
1053 			m_freem(m);
1054 			error = EINVAL;
1055 			break;
1056 		}
1057 	{
1058 		struct in_addr laddr;			/* XXX */
1059 
1060 		if (nam) {
1061 			laddr = inp->inp_laddr;		/* XXX */
1062 			if ((so->so_state & SS_ISCONNECTED) != 0) {
1063 				error = EISCONN;
1064 				goto die;
1065 			}
1066 			error = in_pcbconnect(inp, nam);
1067 			if (error) {
1068 			die:
1069 				m_freem(m);
1070 				break;
1071 			}
1072 		} else {
1073 			if ((so->so_state & SS_ISCONNECTED) == 0) {
1074 				error = ENOTCONN;
1075 				goto die;
1076 			}
1077 		}
1078 		error = udp_output(m, inp);
1079 		if (nam) {
1080 			in_pcbdisconnect(inp);
1081 			inp->inp_laddr = laddr;		/* XXX */
1082 			in_pcbstate(inp, INP_BOUND);	/* XXX */
1083 		}
1084 	}
1085 		break;
1086 
1087 	case PRU_SENSE:
1088 		/*
1089 		 * stat: don't bother with a blocksize.
1090 		 */
1091 		splx(s);
1092 		return (0);
1093 
1094 	case PRU_RCVOOB:
1095 		error =  EOPNOTSUPP;
1096 		break;
1097 
1098 	case PRU_SENDOOB:
1099 		m_freem(control);
1100 		m_freem(m);
1101 		error =  EOPNOTSUPP;
1102 		break;
1103 
1104 	case PRU_SOCKADDR:
1105 		in_setsockaddr(inp, nam);
1106 		break;
1107 
1108 	case PRU_PEERADDR:
1109 		in_setpeeraddr(inp, nam);
1110 		break;
1111 
1112 	default:
1113 		panic("udp_usrreq");
1114 	}
1115 
1116 release:
1117 	splx(s);
1118 	return (error);
1119 }
1120 
1121 /*
1122  * Sysctl for udp variables.
1123  */
1124 int
1125 udp_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1126 	int *name;
1127 	u_int namelen;
1128 	void *oldp;
1129 	size_t *oldlenp;
1130 	void *newp;
1131 	size_t newlen;
1132 {
1133 	/* All sysctl names at this level are terminal. */
1134 	if (namelen != 1)
1135 		return (ENOTDIR);
1136 
1137 	switch (name[0]) {
1138 	case UDPCTL_CHECKSUM:
1139 		return (sysctl_int(oldp, oldlenp, newp, newlen, &udpcksum));
1140 	case UDPCTL_SENDSPACE:
1141 		return (sysctl_int(oldp, oldlenp, newp, newlen,
1142 		    &udp_sendspace));
1143 	case UDPCTL_RECVSPACE:
1144 		return (sysctl_int(oldp, oldlenp, newp, newlen,
1145 		    &udp_recvspace));
1146 	default:
1147 		return (ENOPROTOOPT);
1148 	}
1149 	/* NOTREACHED */
1150 }
1151 #endif
1152