xref: /netbsd-src/sys/netinet/udp_usrreq.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
1 /*	$NetBSD: udp_usrreq.c,v 1.92 2001/12/21 02:51:08 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 1.92 2001/12/21 02:51:08 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 #ifdef INET
143 static void udp4_sendup __P((struct mbuf *, int, struct sockaddr *,
144 	struct socket *));
145 static int udp4_realinput __P((struct sockaddr_in *, struct sockaddr_in *,
146 	struct mbuf *, int));
147 #endif
148 #ifdef INET6
149 static void udp6_sendup __P((struct mbuf *, int, struct sockaddr *,
150 	struct socket *));
151 static int udp6_realinput __P((int, struct sockaddr_in6 *,
152 	struct sockaddr_in6 *, struct mbuf *, int));
153 #endif
154 #ifdef INET
155 static	void udp_notify __P((struct inpcb *, int));
156 #endif
157 
158 #ifndef UDBHASHSIZE
159 #define	UDBHASHSIZE	128
160 #endif
161 int	udbhashsize = UDBHASHSIZE;
162 
163 #ifdef UDP_CSUM_COUNTERS
164 #include <sys/device.h>
165 
166 struct evcnt udp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
167     NULL, "udp", "hwcsum bad");
168 struct evcnt udp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
169     NULL, "udp", "hwcsum ok");
170 struct evcnt udp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
171     NULL, "udp", "hwcsum data");
172 struct evcnt udp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
173     NULL, "udp", "swcsum");
174 
175 #define	UDP_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
176 
177 #else
178 
179 #define	UDP_CSUM_COUNTER_INCR(ev)	/* nothing */
180 
181 #endif /* UDP_CSUM_COUNTERS */
182 
183 void
184 udp_init()
185 {
186 
187 #ifdef INET
188 	in_pcbinit(&udbtable, udbhashsize, udbhashsize);
189 #endif
190 
191 #ifdef UDP_CSUM_COUNTERS
192 	evcnt_attach_static(&udp_hwcsum_bad);
193 	evcnt_attach_static(&udp_hwcsum_ok);
194 	evcnt_attach_static(&udp_hwcsum_data);
195 	evcnt_attach_static(&udp_swcsum);
196 #endif /* UDP_CSUM_COUNTERS */
197 }
198 
199 #ifdef INET
200 void
201 #if __STDC__
202 udp_input(struct mbuf *m, ...)
203 #else
204 udp_input(m, va_alist)
205 	struct mbuf *m;
206 	va_dcl
207 #endif
208 {
209 	va_list ap;
210 	struct sockaddr_in src, dst;
211 	struct ip *ip;
212 	struct udphdr *uh;
213 	int iphlen, proto;
214 	int len;
215 	int n;
216 
217 	va_start(ap, m);
218 	iphlen = va_arg(ap, int);
219 	proto = va_arg(ap, int);
220 	va_end(ap);
221 
222 	udpstat.udps_ipackets++;
223 
224 #ifndef PULLDOWN_TEST
225 	/*
226 	 * Strip IP options, if any; should skip this,
227 	 * make available to user, and use on returned packets,
228 	 * but we don't yet have a way to check the checksum
229 	 * with options still present.
230 	 */
231 	if (iphlen > sizeof (struct ip)) {
232 		ip_stripoptions(m, (struct mbuf *)0);
233 		iphlen = sizeof(struct ip);
234 	}
235 #else
236 	/*
237 	 * we may enable the above code if we save and pass IPv4 options
238 	 * to the userland.
239 	 */
240 #endif
241 
242 	/*
243 	 * Get IP and UDP header together in first mbuf.
244 	 */
245 	ip = mtod(m, struct ip *);
246 #ifndef PULLDOWN_TEST
247 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
248 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
249 			udpstat.udps_hdrops++;
250 			return;
251 		}
252 		ip = mtod(m, struct ip *);
253 	}
254 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
255 #else
256 	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
257 	if (uh == NULL) {
258 		udpstat.udps_hdrops++;
259 		return;
260 	}
261 #endif
262 
263 	/* destination port of 0 is illegal, based on RFC768. */
264 	if (uh->uh_dport == 0)
265 		goto bad;
266 
267 	/*
268 	 * Make mbuf data length reflect UDP length.
269 	 * If not enough data to reflect UDP length, drop.
270 	 */
271 	len = ntohs((u_int16_t)uh->uh_ulen);
272 	if (ip->ip_len != iphlen + len) {
273 		if (ip->ip_len < iphlen + len || len < sizeof(struct udphdr)) {
274 			udpstat.udps_badlen++;
275 			goto bad;
276 		}
277 		m_adj(m, iphlen + len - ip->ip_len);
278 	}
279 
280 	/*
281 	 * Checksum extended UDP header and data.
282 	 */
283 	if (uh->uh_sum) {
284 		switch (m->m_pkthdr.csum_flags &
285 			((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_UDPv4) |
286 			 M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
287 		case M_CSUM_UDPv4|M_CSUM_TCP_UDP_BAD:
288 			UDP_CSUM_COUNTER_INCR(&udp_hwcsum_bad);
289 			goto badcsum;
290 
291 		case M_CSUM_UDPv4|M_CSUM_DATA:
292 			UDP_CSUM_COUNTER_INCR(&udp_hwcsum_data);
293 			if ((m->m_pkthdr.csum_data ^ 0xffff) != 0)
294 				goto badcsum;
295 			break;
296 
297 		case M_CSUM_UDPv4:
298 			/* Checksum was okay. */
299 			UDP_CSUM_COUNTER_INCR(&udp_hwcsum_ok);
300 			break;
301 
302 		default:
303 			/* Need to compute it ourselves. */
304 			UDP_CSUM_COUNTER_INCR(&udp_swcsum);
305 			if (in4_cksum(m, IPPROTO_UDP, iphlen, len) != 0)
306 				goto badcsum;
307 			break;
308 		}
309 	}
310 
311 	/* construct source and dst sockaddrs. */
312 	bzero(&src, sizeof(src));
313 	src.sin_family = AF_INET;
314 	src.sin_len = sizeof(struct sockaddr_in);
315 	bcopy(&ip->ip_src, &src.sin_addr, sizeof(src.sin_addr));
316 	src.sin_port = uh->uh_sport;
317 	bzero(&dst, sizeof(dst));
318 	dst.sin_family = AF_INET;
319 	dst.sin_len = sizeof(struct sockaddr_in);
320 	bcopy(&ip->ip_dst, &dst.sin_addr, sizeof(dst.sin_addr));
321 	dst.sin_port = uh->uh_dport;
322 
323 	n = udp4_realinput(&src, &dst, m, iphlen);
324 #ifdef INET6
325 	if (IN_MULTICAST(ip->ip_dst.s_addr) || n == 0) {
326 		struct sockaddr_in6 src6, dst6;
327 
328 		bzero(&src6, sizeof(src6));
329 		src6.sin6_family = AF_INET6;
330 		src6.sin6_len = sizeof(struct sockaddr_in6);
331 		src6.sin6_addr.s6_addr[10] = src6.sin6_addr.s6_addr[11] = 0xff;
332 		bcopy(&ip->ip_src, &src6.sin6_addr.s6_addr[12],
333 			sizeof(ip->ip_src));
334 		src6.sin6_port = uh->uh_sport;
335 		bzero(&dst6, sizeof(dst6));
336 		dst6.sin6_family = AF_INET6;
337 		dst6.sin6_len = sizeof(struct sockaddr_in6);
338 		dst6.sin6_addr.s6_addr[10] = dst6.sin6_addr.s6_addr[11] = 0xff;
339 		bcopy(&ip->ip_dst, &dst6.sin6_addr.s6_addr[12],
340 			sizeof(ip->ip_dst));
341 		dst6.sin6_port = uh->uh_dport;
342 
343 		n += udp6_realinput(AF_INET, &src6, &dst6, m, iphlen);
344 	}
345 #endif
346 
347 	if (n == 0) {
348 		if (m->m_flags & (M_BCAST | M_MCAST)) {
349 			udpstat.udps_noportbcast++;
350 			goto bad;
351 		}
352 		udpstat.udps_noport++;
353 #ifdef IPKDB
354 		if (checkipkdb(&ip->ip_src, uh->uh_sport, uh->uh_dport,
355 				m, iphlen + sizeof(struct udphdr),
356 				m->m_pkthdr.len - iphlen - sizeof(struct udphdr))) {
357 			/*
358 			 * It was a debugger connect packet,
359 			 * just drop it now
360 			 */
361 			goto bad;
362 		}
363 #endif
364 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
365 		m = NULL;
366 	}
367 
368 bad:
369 	if (m)
370 		m_freem(m);
371 	return;
372 
373 badcsum:
374 	m_freem(m);
375 	udpstat.udps_badsum++;
376 }
377 #endif
378 
379 #ifdef INET6
380 int
381 udp6_input(mp, offp, proto)
382 	struct mbuf **mp;
383 	int *offp, proto;
384 {
385 	struct mbuf *m = *mp;
386 	int off = *offp;
387 	struct sockaddr_in6 src, dst;
388 	struct ip6_hdr *ip6;
389 	struct udphdr *uh;
390 	u_int32_t plen, ulen;
391 
392 #ifndef PULLDOWN_TEST
393 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
394 #endif
395 	ip6 = mtod(m, struct ip6_hdr *);
396 
397 #if defined(NFAITH) && 0 < NFAITH
398 	if (faithprefix(&ip6->ip6_dst)) {
399 		/* send icmp6 host unreach? */
400 		m_freem(m);
401 		return IPPROTO_DONE;
402 	}
403 #endif
404 
405 	udp6stat.udp6s_ipackets++;
406 
407 	/* check for jumbogram is done in ip6_input.  we can trust pkthdr.len */
408 	plen = m->m_pkthdr.len - off;
409 #ifndef PULLDOWN_TEST
410 	uh = (struct udphdr *)((caddr_t)ip6 + off);
411 #else
412 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(struct udphdr));
413 	if (uh == NULL) {
414 		ip6stat.ip6s_tooshort++;
415 		return IPPROTO_DONE;
416 	}
417 #endif
418 	ulen = ntohs((u_short)uh->uh_ulen);
419 	/*
420 	 * RFC2675 section 4: jumbograms will have 0 in the UDP header field,
421 	 * iff payload length > 0xffff.
422 	 */
423 	if (ulen == 0 && plen > 0xffff)
424 		ulen = plen;
425 
426 	if (plen != ulen) {
427 		udp6stat.udp6s_badlen++;
428 		goto bad;
429 	}
430 
431 	/* destination port of 0 is illegal, based on RFC768. */
432 	if (uh->uh_dport == 0)
433 		goto bad;
434 
435 	/* Be proactive about malicious use of IPv4 mapped address */
436 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
437 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
438 		/* XXX stat */
439 		goto bad;
440 	}
441 
442 	/*
443 	 * Checksum extended UDP header and data.
444 	 */
445 	if (uh->uh_sum == 0)
446 		udp6stat.udp6s_nosum++;
447 	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
448 		udp6stat.udp6s_badsum++;
449 		goto bad;
450 	}
451 
452 	/*
453 	 * Construct source and dst sockaddrs.
454 	 * Note that ifindex (s6_addr16[1]) is already filled.
455 	 */
456 	bzero(&src, sizeof(src));
457 	src.sin6_family = AF_INET6;
458 	src.sin6_len = sizeof(struct sockaddr_in6);
459 	/* KAME hack: recover scopeid */
460 	(void)in6_recoverscope(&src, &ip6->ip6_src, m->m_pkthdr.rcvif);
461 	src.sin6_port = uh->uh_sport;
462 	bzero(&dst, sizeof(dst));
463 	dst.sin6_family = AF_INET6;
464 	dst.sin6_len = sizeof(struct sockaddr_in6);
465 	/* KAME hack: recover scopeid */
466 	(void)in6_recoverscope(&dst, &ip6->ip6_dst, m->m_pkthdr.rcvif);
467 	dst.sin6_port = uh->uh_dport;
468 
469 	if (udp6_realinput(AF_INET6, &src, &dst, m, off) == 0) {
470 		if (m->m_flags & M_MCAST) {
471 			udp6stat.udp6s_noportmcast++;
472 			goto bad;
473 		}
474 		udp6stat.udp6s_noport++;
475 		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
476 		m = NULL;
477 	}
478 
479 bad:
480 	if (m)
481 		m_freem(m);
482 	return IPPROTO_DONE;
483 }
484 #endif
485 
486 #ifdef INET
487 static void
488 udp4_sendup(m, off, src, so)
489 	struct mbuf *m;
490 	int off;	/* offset of data portion */
491 	struct sockaddr *src;
492 	struct socket *so;
493 {
494 	struct mbuf *opts = NULL;
495 	struct mbuf *n;
496 	struct inpcb *inp = NULL;
497 #ifdef INET6
498 	struct in6pcb *in6p = NULL;
499 #endif
500 
501 	if (!so)
502 		return;
503 	switch (so->so_proto->pr_domain->dom_family) {
504 	case AF_INET:
505 		inp = sotoinpcb(so);
506 		break;
507 #ifdef INET6
508 	case AF_INET6:
509 		in6p = sotoin6pcb(so);
510 		break;
511 #endif
512 	default:
513 		return;
514 	}
515 
516 #ifdef IPSEC
517 	/* check AH/ESP integrity. */
518 	if (so != NULL && ipsec4_in_reject_so(m, so)) {
519 		ipsecstat.in_polvio++;
520 		return;
521 	}
522 #endif /*IPSEC*/
523 
524 	if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
525 		if (inp && (inp->inp_flags & INP_CONTROLOPTS
526 			 || so->so_options & SO_TIMESTAMP)) {
527 			struct ip *ip = mtod(n, struct ip *);
528 			ip_savecontrol(inp, &opts, ip, n);
529 		}
530 
531 		m_adj(n, off);
532 		if (sbappendaddr(&so->so_rcv, src, n,
533 				opts) == 0) {
534 			m_freem(n);
535 			if (opts)
536 				m_freem(opts);
537 			udpstat.udps_fullsock++;
538 		} else
539 			sorwakeup(so);
540 	}
541 }
542 #endif
543 
544 #ifdef INET6
545 static void
546 udp6_sendup(m, off, src, so)
547 	struct mbuf *m;
548 	int off;	/* offset of data portion */
549 	struct sockaddr *src;
550 	struct socket *so;
551 {
552 	struct mbuf *opts = NULL;
553 	struct mbuf *n;
554 	struct in6pcb *in6p = NULL;
555 
556 	if (!so)
557 		return;
558 	if (so->so_proto->pr_domain->dom_family != AF_INET6)
559 		return;
560 	in6p = sotoin6pcb(so);
561 
562 #ifdef IPSEC
563 	/* check AH/ESP integrity. */
564 	if (so != NULL && ipsec6_in_reject_so(m, so)) {
565 		ipsec6stat.in_polvio++;
566 		return;
567 	}
568 #endif /*IPSEC*/
569 
570 	if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
571 		if (in6p && (in6p->in6p_flags & IN6P_CONTROLOPTS
572 			  || in6p->in6p_socket->so_options & SO_TIMESTAMP)) {
573 			struct ip6_hdr *ip6 = mtod(n, struct ip6_hdr *);
574 			ip6_savecontrol(in6p, &opts, ip6, n);
575 		}
576 
577 		m_adj(n, off);
578 		if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
579 			m_freem(n);
580 			if (opts)
581 				m_freem(opts);
582 			udp6stat.udp6s_fullsock++;
583 		} else
584 			sorwakeup(so);
585 	}
586 }
587 #endif
588 
589 #ifdef INET
590 static int
591 udp4_realinput(src, dst, m, off)
592 	struct sockaddr_in *src;
593 	struct sockaddr_in *dst;
594 	struct mbuf *m;
595 	int off;	/* offset of udphdr */
596 {
597 	u_int16_t *sport, *dport;
598 	int rcvcnt;
599 	struct in_addr *src4, *dst4;
600 	struct inpcb *inp;
601 
602 	rcvcnt = 0;
603 	off += sizeof(struct udphdr);	/* now, offset of payload */
604 
605 	if (src->sin_family != AF_INET || dst->sin_family != AF_INET)
606 		goto bad;
607 
608 	src4 = &src->sin_addr;
609 	sport = &src->sin_port;
610 	dst4 = &dst->sin_addr;
611 	dport = &dst->sin_port;
612 
613 	if (IN_MULTICAST(dst4->s_addr) ||
614 	    in_broadcast(*dst4, m->m_pkthdr.rcvif)) {
615 		struct inpcb *last;
616 		/*
617 		 * Deliver a multicast or broadcast datagram to *all* sockets
618 		 * for which the local and remote addresses and ports match
619 		 * those of the incoming datagram.  This allows more than
620 		 * one process to receive multi/broadcasts on the same port.
621 		 * (This really ought to be done for unicast datagrams as
622 		 * well, but that would cause problems with existing
623 		 * applications that open both address-specific sockets and
624 		 * a wildcard socket listening to the same port -- they would
625 		 * end up receiving duplicates of every unicast datagram.
626 		 * Those applications open the multiple sockets to overcome an
627 		 * inadequacy of the UDP socket interface, but for backwards
628 		 * compatibility we avoid the problem here rather than
629 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
630 		 */
631 
632 		/*
633 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
634 		 * we need udpiphdr for IPsec processing so we do that later.
635 		 */
636 		/*
637 		 * Locate pcb(s) for datagram.
638 		 */
639 		CIRCLEQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
640 			if (inp->inp_lport != *dport)
641 				continue;
642 			if (!in_nullhost(inp->inp_laddr)) {
643 				if (!in_hosteq(inp->inp_laddr, *dst4))
644 					continue;
645 			}
646 			if (!in_nullhost(inp->inp_faddr)) {
647 				if (!in_hosteq(inp->inp_faddr, *src4) ||
648 				    inp->inp_fport != *sport)
649 					continue;
650 			}
651 
652 			last = inp;
653 			udp4_sendup(m, off, (struct sockaddr *)src,
654 				inp->inp_socket);
655 			rcvcnt++;
656 
657 			/*
658 			 * Don't look for additional matches if this one does
659 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
660 			 * socket options set.  This heuristic avoids searching
661 			 * through all pcbs in the common case of a non-shared
662 			 * port.  It assumes that an application will never
663 			 * clear these options after setting them.
664 			 */
665 			if ((inp->inp_socket->so_options &
666 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
667 				break;
668 		}
669 	} else {
670 		/*
671 		 * Locate pcb for datagram.
672 		 */
673 		inp = in_pcblookup_connect(&udbtable, *src4, *sport, *dst4, *dport);
674 		if (inp == 0) {
675 			++udpstat.udps_pcbhashmiss;
676 			inp = in_pcblookup_bind(&udbtable, *dst4, *dport);
677 			if (inp == 0)
678 				return rcvcnt;
679 		}
680 
681 		udp4_sendup(m, off, (struct sockaddr *)src, inp->inp_socket);
682 		rcvcnt++;
683 	}
684 
685 bad:
686 	return rcvcnt;
687 }
688 #endif
689 
690 #ifdef INET6
691 static int
692 udp6_realinput(af, src, dst, m, off)
693 	int af;		/* af on packet */
694 	struct sockaddr_in6 *src;
695 	struct sockaddr_in6 *dst;
696 	struct mbuf *m;
697 	int off;	/* offset of udphdr */
698 {
699 	u_int16_t sport, dport;
700 	int rcvcnt;
701 	struct in6_addr src6, dst6;
702 	const struct in_addr *dst4;
703 	struct in6pcb *in6p;
704 
705 	rcvcnt = 0;
706 	off += sizeof(struct udphdr);	/* now, offset of payload */
707 
708 	if (af != AF_INET && af != AF_INET6)
709 		goto bad;
710 	if (src->sin6_family != AF_INET6 || dst->sin6_family != AF_INET6)
711 		goto bad;
712 
713 	in6_embedscope(&src6, src, NULL, NULL);
714 	sport = src->sin6_port;
715 	in6_embedscope(&dst6, dst, NULL, NULL);
716 	dport = dst->sin6_port;
717 	dst4 = (struct in_addr *)&dst->sin6_addr.s6_addr[12];
718 
719 	if (IN6_IS_ADDR_MULTICAST(&dst6) ||
720 	    (af == AF_INET && IN_MULTICAST(dst4->s_addr))) {
721 		struct in6pcb *last;
722 		/*
723 		 * Deliver a multicast or broadcast datagram to *all* sockets
724 		 * for which the local and remote addresses and ports match
725 		 * those of the incoming datagram.  This allows more than
726 		 * one process to receive multi/broadcasts on the same port.
727 		 * (This really ought to be done for unicast datagrams as
728 		 * well, but that would cause problems with existing
729 		 * applications that open both address-specific sockets and
730 		 * a wildcard socket listening to the same port -- they would
731 		 * end up receiving duplicates of every unicast datagram.
732 		 * Those applications open the multiple sockets to overcome an
733 		 * inadequacy of the UDP socket interface, but for backwards
734 		 * compatibility we avoid the problem here rather than
735 		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
736 		 */
737 
738 		/*
739 		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
740 		 * we need udpiphdr for IPsec processing so we do that later.
741 		 */
742 		/*
743 		 * Locate pcb(s) for datagram.
744 		 */
745 		for (in6p = udb6.in6p_next; in6p != &udb6;
746 		     in6p = in6p->in6p_next) {
747 			if (in6p->in6p_lport != dport)
748 				continue;
749 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
750 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &dst6))
751 					continue;
752 			} else {
753 				if (IN6_IS_ADDR_V4MAPPED(&dst6) &&
754 				    (in6p->in6p_flags & IN6P_IPV6_V6ONLY))
755 					continue;
756 			}
757 			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
758 				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
759 				    &src6) || in6p->in6p_fport != sport)
760 					continue;
761 			} else {
762 				if (IN6_IS_ADDR_V4MAPPED(&src6) &&
763 				    (in6p->in6p_flags & IN6P_IPV6_V6ONLY))
764 					continue;
765 			}
766 
767 			last = in6p;
768 			udp6_sendup(m, off, (struct sockaddr *)src,
769 				in6p->in6p_socket);
770 			rcvcnt++;
771 
772 			/*
773 			 * Don't look for additional matches if this one does
774 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
775 			 * socket options set.  This heuristic avoids searching
776 			 * through all pcbs in the common case of a non-shared
777 			 * port.  It assumes that an application will never
778 			 * clear these options after setting them.
779 			 */
780 			if ((in6p->in6p_socket->so_options &
781 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
782 				break;
783 		}
784 	} else {
785 		/*
786 		 * Locate pcb for datagram.
787 		 */
788 		in6p = in6_pcblookup_connect(&udb6, &src6, sport,
789 		    &dst6, dport, 0);
790 		if (in6p == 0) {
791 			++udpstat.udps_pcbhashmiss;
792 			in6p = in6_pcblookup_bind(&udb6, &dst6, dport, 0);
793 			if (in6p == 0)
794 				return rcvcnt;
795 		}
796 
797 		udp6_sendup(m, off, (struct sockaddr *)src, in6p->in6p_socket);
798 		rcvcnt++;
799 	}
800 
801 bad:
802 	return rcvcnt;
803 }
804 #endif
805 
806 #ifdef INET
807 /*
808  * Notify a udp user of an asynchronous error;
809  * just wake up so that he can collect error status.
810  */
811 static void
812 udp_notify(inp, errno)
813 	struct inpcb *inp;
814 	int errno;
815 {
816 
817 	inp->inp_socket->so_error = errno;
818 	sorwakeup(inp->inp_socket);
819 	sowwakeup(inp->inp_socket);
820 }
821 
822 void *
823 udp_ctlinput(cmd, sa, v)
824 	int cmd;
825 	struct sockaddr *sa;
826 	void *v;
827 {
828 	struct ip *ip = v;
829 	struct udphdr *uh;
830 	void (*notify) __P((struct inpcb *, int)) = udp_notify;
831 	int errno;
832 
833 	if (sa->sa_family != AF_INET
834 	 || sa->sa_len != sizeof(struct sockaddr_in))
835 		return NULL;
836 	if ((unsigned)cmd >= PRC_NCMDS)
837 		return NULL;
838 	errno = inetctlerrmap[cmd];
839 	if (PRC_IS_REDIRECT(cmd))
840 		notify = in_rtchange, ip = 0;
841 	else if (cmd == PRC_HOSTDEAD)
842 		ip = 0;
843 	else if (errno == 0)
844 		return NULL;
845 	if (ip) {
846 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
847 		in_pcbnotify(&udbtable, satosin(sa)->sin_addr, uh->uh_dport,
848 		    ip->ip_src, uh->uh_sport, errno, notify);
849 
850 		/* XXX mapped address case */
851 	} else
852 		in_pcbnotifyall(&udbtable, satosin(sa)->sin_addr, errno,
853 		    notify);
854 	return NULL;
855 }
856 
857 int
858 #if __STDC__
859 udp_output(struct mbuf *m, ...)
860 #else
861 udp_output(m, va_alist)
862 	struct mbuf *m;
863 	va_dcl
864 #endif
865 {
866 	struct inpcb *inp;
867 	struct udpiphdr *ui;
868 	int len = m->m_pkthdr.len;
869 	int error = 0;
870 	va_list ap;
871 
872 	va_start(ap, m);
873 	inp = va_arg(ap, struct inpcb *);
874 	va_end(ap);
875 
876 	/*
877 	 * Calculate data length and get a mbuf
878 	 * for UDP and IP headers.
879 	 */
880 	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
881 	if (m == 0) {
882 		error = ENOBUFS;
883 		goto release;
884 	}
885 
886 	/*
887 	 * Compute the packet length of the IP header, and
888 	 * punt if the length looks bogus.
889 	 */
890 	if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) {
891 		error = EMSGSIZE;
892 		goto release;
893 	}
894 
895 	/*
896 	 * Fill in mbuf with extended UDP header
897 	 * and addresses and length put into network format.
898 	 */
899 	ui = mtod(m, struct udpiphdr *);
900 	ui->ui_pr = IPPROTO_UDP;
901 	ui->ui_src = inp->inp_laddr;
902 	ui->ui_dst = inp->inp_faddr;
903 	ui->ui_sport = inp->inp_lport;
904 	ui->ui_dport = inp->inp_fport;
905 	ui->ui_ulen = htons((u_int16_t)len + sizeof(struct udphdr));
906 
907 	/*
908 	 * Set up checksum and output datagram.
909 	 */
910 	if (udpcksum) {
911 		/*
912 		 * XXX Cache pseudo-header checksum part for
913 		 * XXX "connected" UDP sockets.
914 		 */
915 		ui->ui_sum = in_cksum_phdr(ui->ui_src.s_addr,
916 		    ui->ui_dst.s_addr, htons((u_int16_t)len +
917 		    sizeof(struct udphdr) + IPPROTO_UDP));
918 		m->m_pkthdr.csum_flags = M_CSUM_UDPv4;
919 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
920 	} else
921 		ui->ui_sum = 0;
922 	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
923 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;	/* XXX */
924 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;	/* XXX */
925 	udpstat.udps_opackets++;
926 
927 #ifdef IPSEC
928 	if (ipsec_setsocket(m, inp->inp_socket) != 0) {
929 		error = ENOBUFS;
930 		goto release;
931 	}
932 #endif /*IPSEC*/
933 
934 	return (ip_output(m, inp->inp_options, &inp->inp_route,
935 	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST),
936 	    inp->inp_moptions));
937 
938 release:
939 	m_freem(m);
940 	return (error);
941 }
942 
943 int	udp_sendspace = 9216;		/* really max datagram size */
944 int	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
945 					/* 40 1K datagrams */
946 
947 /*ARGSUSED*/
948 int
949 udp_usrreq(so, req, m, nam, control, p)
950 	struct socket *so;
951 	int req;
952 	struct mbuf *m, *nam, *control;
953 	struct proc *p;
954 {
955 	struct inpcb *inp;
956 	int s;
957 	int error = 0;
958 
959 	if (req == PRU_CONTROL)
960 		return (in_control(so, (long)m, (caddr_t)nam,
961 		    (struct ifnet *)control, p));
962 
963 	if (req == PRU_PURGEIF) {
964 		in_pcbpurgeif0(&udbtable, (struct ifnet *)control);
965 		in_purgeif((struct ifnet *)control);
966 		in_pcbpurgeif(&udbtable, (struct ifnet *)control);
967 		return (0);
968 	}
969 
970 	s = splsoftnet();
971 	inp = sotoinpcb(so);
972 #ifdef DIAGNOSTIC
973 	if (req != PRU_SEND && req != PRU_SENDOOB && control)
974 		panic("udp_usrreq: unexpected control mbuf");
975 #endif
976 	if (inp == 0 && req != PRU_ATTACH) {
977 		error = EINVAL;
978 		goto release;
979 	}
980 
981 	/*
982 	 * Note: need to block udp_input while changing
983 	 * the udp pcb queue and/or pcb addresses.
984 	 */
985 	switch (req) {
986 
987 	case PRU_ATTACH:
988 		if (inp != 0) {
989 			error = EISCONN;
990 			break;
991 		}
992 		if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
993 			error = soreserve(so, udp_sendspace, udp_recvspace);
994 			if (error)
995 				break;
996 		}
997 		error = in_pcballoc(so, &udbtable);
998 		if (error)
999 			break;
1000 		inp = sotoinpcb(so);
1001 		inp->inp_ip.ip_ttl = ip_defttl;
1002 		break;
1003 
1004 	case PRU_DETACH:
1005 		in_pcbdetach(inp);
1006 		break;
1007 
1008 	case PRU_BIND:
1009 		error = in_pcbbind(inp, nam, p);
1010 		break;
1011 
1012 	case PRU_LISTEN:
1013 		error = EOPNOTSUPP;
1014 		break;
1015 
1016 	case PRU_CONNECT:
1017 		error = in_pcbconnect(inp, nam);
1018 		if (error)
1019 			break;
1020 		soisconnected(so);
1021 		break;
1022 
1023 	case PRU_CONNECT2:
1024 		error = EOPNOTSUPP;
1025 		break;
1026 
1027 	case PRU_DISCONNECT:
1028 		/*soisdisconnected(so);*/
1029 		so->so_state &= ~SS_ISCONNECTED;	/* XXX */
1030 		in_pcbdisconnect(inp);
1031 		inp->inp_laddr = zeroin_addr;		/* XXX */
1032 		in_pcbstate(inp, INP_BOUND);		/* XXX */
1033 		break;
1034 
1035 	case PRU_SHUTDOWN:
1036 		socantsendmore(so);
1037 		break;
1038 
1039 	case PRU_RCVD:
1040 		error = EOPNOTSUPP;
1041 		break;
1042 
1043 	case PRU_SEND:
1044 		if (control && control->m_len) {
1045 			m_freem(control);
1046 			m_freem(m);
1047 			error = EINVAL;
1048 			break;
1049 		}
1050 	{
1051 		struct in_addr laddr;			/* XXX */
1052 
1053 		if (nam) {
1054 			laddr = inp->inp_laddr;		/* XXX */
1055 			if ((so->so_state & SS_ISCONNECTED) != 0) {
1056 				error = EISCONN;
1057 				goto die;
1058 			}
1059 			error = in_pcbconnect(inp, nam);
1060 			if (error) {
1061 			die:
1062 				m_freem(m);
1063 				break;
1064 			}
1065 		} else {
1066 			if ((so->so_state & SS_ISCONNECTED) == 0) {
1067 				error = ENOTCONN;
1068 				goto die;
1069 			}
1070 		}
1071 		error = udp_output(m, inp);
1072 		if (nam) {
1073 			in_pcbdisconnect(inp);
1074 			inp->inp_laddr = laddr;		/* XXX */
1075 			in_pcbstate(inp, INP_BOUND);	/* XXX */
1076 		}
1077 	}
1078 		break;
1079 
1080 	case PRU_SENSE:
1081 		/*
1082 		 * stat: don't bother with a blocksize.
1083 		 */
1084 		splx(s);
1085 		return (0);
1086 
1087 	case PRU_RCVOOB:
1088 		error =  EOPNOTSUPP;
1089 		break;
1090 
1091 	case PRU_SENDOOB:
1092 		m_freem(control);
1093 		m_freem(m);
1094 		error =  EOPNOTSUPP;
1095 		break;
1096 
1097 	case PRU_SOCKADDR:
1098 		in_setsockaddr(inp, nam);
1099 		break;
1100 
1101 	case PRU_PEERADDR:
1102 		in_setpeeraddr(inp, nam);
1103 		break;
1104 
1105 	default:
1106 		panic("udp_usrreq");
1107 	}
1108 
1109 release:
1110 	splx(s);
1111 	return (error);
1112 }
1113 
1114 /*
1115  * Sysctl for udp variables.
1116  */
1117 int
1118 udp_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
1119 	int *name;
1120 	u_int namelen;
1121 	void *oldp;
1122 	size_t *oldlenp;
1123 	void *newp;
1124 	size_t newlen;
1125 {
1126 	/* All sysctl names at this level are terminal. */
1127 	if (namelen != 1)
1128 		return (ENOTDIR);
1129 
1130 	switch (name[0]) {
1131 	case UDPCTL_CHECKSUM:
1132 		return (sysctl_int(oldp, oldlenp, newp, newlen, &udpcksum));
1133 	case UDPCTL_SENDSPACE:
1134 		return (sysctl_int(oldp, oldlenp, newp, newlen,
1135 		    &udp_sendspace));
1136 	case UDPCTL_RECVSPACE:
1137 		return (sysctl_int(oldp, oldlenp, newp, newlen,
1138 		    &udp_recvspace));
1139 	default:
1140 		return (ENOPROTOOPT);
1141 	}
1142 	/* NOTREACHED */
1143 }
1144 #endif
1145