xref: /freebsd/sys/netinet/udp_usrreq.c (revision aa0a1e58)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3  *	The Regents of the University of California.
4  * Copyright (c) 2008 Robert N. M. Watson
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  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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  *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_ipfw.h"
38 #include "opt_inet6.h"
39 #include "opt_ipsec.h"
40 
41 #include <sys/param.h>
42 #include <sys/domain.h>
43 #include <sys/eventhandler.h>
44 #include <sys/jail.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/protosw.h>
52 #include <sys/signalvar.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57 #include <sys/syslog.h>
58 #include <sys/systm.h>
59 
60 #include <vm/uma.h>
61 
62 #include <net/if.h>
63 #include <net/route.h>
64 
65 #include <netinet/in.h>
66 #include <netinet/in_pcb.h>
67 #include <netinet/in_systm.h>
68 #include <netinet/in_var.h>
69 #include <netinet/ip.h>
70 #ifdef INET6
71 #include <netinet/ip6.h>
72 #endif
73 #include <netinet/ip_icmp.h>
74 #include <netinet/icmp_var.h>
75 #include <netinet/ip_var.h>
76 #include <netinet/ip_options.h>
77 #ifdef INET6
78 #include <netinet6/ip6_var.h>
79 #endif
80 #include <netinet/udp.h>
81 #include <netinet/udp_var.h>
82 
83 #ifdef IPSEC
84 #include <netipsec/ipsec.h>
85 #include <netipsec/esp.h>
86 #endif
87 
88 #include <machine/in_cksum.h>
89 
90 #include <security/mac/mac_framework.h>
91 
92 /*
93  * UDP protocol implementation.
94  * Per RFC 768, August, 1980.
95  */
96 
97 /*
98  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
99  * removes the only data integrity mechanism for packets and malformed
100  * packets that would otherwise be discarded due to bad checksums, and may
101  * cause problems (especially for NFS data blocks).
102  */
103 static int	udp_cksum = 1;
104 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum,
105     0, "compute udp checksum");
106 
107 int	udp_log_in_vain = 0;
108 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
109     &udp_log_in_vain, 0, "Log all incoming UDP packets");
110 
111 VNET_DEFINE(int, udp_blackhole) = 0;
112 SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
113     &VNET_NAME(udp_blackhole), 0,
114     "Do not send port unreachables for refused connects");
115 
116 u_long	udp_sendspace = 9216;		/* really max datagram size */
117 					/* 40 1K datagrams */
118 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
119     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
120 
121 u_long	udp_recvspace = 40 * (1024 +
122 #ifdef INET6
123 				      sizeof(struct sockaddr_in6)
124 #else
125 				      sizeof(struct sockaddr_in)
126 #endif
127 				      );
128 
129 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
130     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
131 
132 VNET_DEFINE(struct inpcbhead, udb);		/* from udp_var.h */
133 VNET_DEFINE(struct inpcbinfo, udbinfo);
134 static VNET_DEFINE(uma_zone_t, udpcb_zone);
135 #define	V_udpcb_zone			VNET(udpcb_zone)
136 
137 #ifndef UDBHASHSIZE
138 #define	UDBHASHSIZE	128
139 #endif
140 
141 VNET_DEFINE(struct udpstat, udpstat);		/* from udp_var.h */
142 SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
143     &VNET_NAME(udpstat), udpstat,
144     "UDP statistics (struct udpstat, netinet/udp_var.h)");
145 
146 static void	udp_detach(struct socket *so);
147 static int	udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
148 		    struct mbuf *, struct thread *);
149 #ifdef IPSEC
150 #ifdef IPSEC_NAT_T
151 #define	UF_ESPINUDP_ALL	(UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
152 #ifdef INET
153 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
154 #endif
155 #endif /* IPSEC_NAT_T */
156 #endif /* IPSEC */
157 
158 static void
159 udp_zone_change(void *tag)
160 {
161 
162 	uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
163 	uma_zone_set_max(V_udpcb_zone, maxsockets);
164 }
165 
166 static int
167 udp_inpcb_init(void *mem, int size, int flags)
168 {
169 	struct inpcb *inp;
170 
171 	inp = mem;
172 	INP_LOCK_INIT(inp, "inp", "udpinp");
173 	return (0);
174 }
175 
176 void
177 udp_init(void)
178 {
179 
180 	in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
181 	    "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE);
182 	V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
183 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
184 	uma_zone_set_max(V_udpcb_zone, maxsockets);
185 	EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
186 	    EVENTHANDLER_PRI_ANY);
187 }
188 
189 /*
190  * Kernel module interface for updating udpstat.  The argument is an index
191  * into udpstat treated as an array of u_long.  While this encodes the
192  * general layout of udpstat into the caller, it doesn't encode its location,
193  * so that future changes to add, for example, per-CPU stats support won't
194  * cause binary compatibility problems for kernel modules.
195  */
196 void
197 kmod_udpstat_inc(int statnum)
198 {
199 
200 	(*((u_long *)&V_udpstat + statnum))++;
201 }
202 
203 int
204 udp_newudpcb(struct inpcb *inp)
205 {
206 	struct udpcb *up;
207 
208 	up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
209 	if (up == NULL)
210 		return (ENOBUFS);
211 	inp->inp_ppcb = up;
212 	return (0);
213 }
214 
215 void
216 udp_discardcb(struct udpcb *up)
217 {
218 
219 	uma_zfree(V_udpcb_zone, up);
220 }
221 
222 #ifdef VIMAGE
223 void
224 udp_destroy(void)
225 {
226 
227 	in_pcbinfo_destroy(&V_udbinfo);
228 	uma_zdestroy(V_udpcb_zone);
229 }
230 #endif
231 
232 /*
233  * Subroutine of udp_input(), which appends the provided mbuf chain to the
234  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
235  * contains the source address.  If the socket ends up being an IPv6 socket,
236  * udp_append() will convert to a sockaddr_in6 before passing the address
237  * into the socket code.
238  */
239 static void
240 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
241     struct sockaddr_in *udp_in)
242 {
243 	struct sockaddr *append_sa;
244 	struct socket *so;
245 	struct mbuf *opts = 0;
246 #ifdef INET6
247 	struct sockaddr_in6 udp_in6;
248 #endif
249 #ifdef IPSEC
250 #ifdef IPSEC_NAT_T
251 #ifdef INET
252 	struct udpcb *up;
253 #endif
254 #endif
255 #endif
256 
257 	INP_RLOCK_ASSERT(inp);
258 
259 #ifdef IPSEC
260 	/* Check AH/ESP integrity. */
261 	if (ipsec4_in_reject(n, inp)) {
262 		m_freem(n);
263 		V_ipsec4stat.in_polvio++;
264 		return;
265 	}
266 #ifdef IPSEC_NAT_T
267 #ifdef INET
268 	up = intoudpcb(inp);
269 	KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
270 	if (up->u_flags & UF_ESPINUDP_ALL) {	/* IPSec UDP encaps. */
271 		n = udp4_espdecap(inp, n, off);
272 		if (n == NULL)				/* Consumed. */
273 			return;
274 	}
275 #endif /* INET */
276 #endif /* IPSEC_NAT_T */
277 #endif /* IPSEC */
278 #ifdef MAC
279 	if (mac_inpcb_check_deliver(inp, n) != 0) {
280 		m_freem(n);
281 		return;
282 	}
283 #endif
284 	if (inp->inp_flags & INP_CONTROLOPTS ||
285 	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
286 #ifdef INET6
287 		if (inp->inp_vflag & INP_IPV6)
288 			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
289 		else
290 #endif
291 			ip_savecontrol(inp, &opts, ip, n);
292 	}
293 #ifdef INET6
294 	if (inp->inp_vflag & INP_IPV6) {
295 		bzero(&udp_in6, sizeof(udp_in6));
296 		udp_in6.sin6_len = sizeof(udp_in6);
297 		udp_in6.sin6_family = AF_INET6;
298 		in6_sin_2_v4mapsin6(udp_in, &udp_in6);
299 		append_sa = (struct sockaddr *)&udp_in6;
300 	} else
301 #endif
302 		append_sa = (struct sockaddr *)udp_in;
303 	m_adj(n, off);
304 
305 	so = inp->inp_socket;
306 	SOCKBUF_LOCK(&so->so_rcv);
307 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
308 		SOCKBUF_UNLOCK(&so->so_rcv);
309 		m_freem(n);
310 		if (opts)
311 			m_freem(opts);
312 		UDPSTAT_INC(udps_fullsock);
313 	} else
314 		sorwakeup_locked(so);
315 }
316 
317 void
318 udp_input(struct mbuf *m, int off)
319 {
320 	int iphlen = off;
321 	struct ip *ip;
322 	struct udphdr *uh;
323 	struct ifnet *ifp;
324 	struct inpcb *inp;
325 	struct udpcb *up;
326 	int len;
327 	struct ip save_ip;
328 	struct sockaddr_in udp_in;
329 #ifdef IPFIREWALL_FORWARD
330 	struct m_tag *fwd_tag;
331 #endif
332 
333 	ifp = m->m_pkthdr.rcvif;
334 	UDPSTAT_INC(udps_ipackets);
335 
336 	/*
337 	 * Strip IP options, if any; should skip this, make available to
338 	 * user, and use on returned packets, but we don't yet have a way to
339 	 * check the checksum with options still present.
340 	 */
341 	if (iphlen > sizeof (struct ip)) {
342 		ip_stripoptions(m, (struct mbuf *)0);
343 		iphlen = sizeof(struct ip);
344 	}
345 
346 	/*
347 	 * Get IP and UDP header together in first mbuf.
348 	 */
349 	ip = mtod(m, struct ip *);
350 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
351 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
352 			UDPSTAT_INC(udps_hdrops);
353 			return;
354 		}
355 		ip = mtod(m, struct ip *);
356 	}
357 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
358 
359 	/*
360 	 * Destination port of 0 is illegal, based on RFC768.
361 	 */
362 	if (uh->uh_dport == 0)
363 		goto badunlocked;
364 
365 	/*
366 	 * Construct sockaddr format source address.  Stuff source address
367 	 * and datagram in user buffer.
368 	 */
369 	bzero(&udp_in, sizeof(udp_in));
370 	udp_in.sin_len = sizeof(udp_in);
371 	udp_in.sin_family = AF_INET;
372 	udp_in.sin_port = uh->uh_sport;
373 	udp_in.sin_addr = ip->ip_src;
374 
375 	/*
376 	 * Make mbuf data length reflect UDP length.  If not enough data to
377 	 * reflect UDP length, drop.
378 	 */
379 	len = ntohs((u_short)uh->uh_ulen);
380 	if (ip->ip_len != len) {
381 		if (len > ip->ip_len || len < sizeof(struct udphdr)) {
382 			UDPSTAT_INC(udps_badlen);
383 			goto badunlocked;
384 		}
385 		m_adj(m, len - ip->ip_len);
386 		/* ip->ip_len = len; */
387 	}
388 
389 	/*
390 	 * Save a copy of the IP header in case we want restore it for
391 	 * sending an ICMP error message in response.
392 	 */
393 	if (!V_udp_blackhole)
394 		save_ip = *ip;
395 	else
396 		memset(&save_ip, 0, sizeof(save_ip));
397 
398 	/*
399 	 * Checksum extended UDP header and data.
400 	 */
401 	if (uh->uh_sum) {
402 		u_short uh_sum;
403 
404 		if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
405 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
406 				uh_sum = m->m_pkthdr.csum_data;
407 			else
408 				uh_sum = in_pseudo(ip->ip_src.s_addr,
409 				    ip->ip_dst.s_addr, htonl((u_short)len +
410 				    m->m_pkthdr.csum_data + IPPROTO_UDP));
411 			uh_sum ^= 0xffff;
412 		} else {
413 			char b[9];
414 
415 			bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
416 			bzero(((struct ipovly *)ip)->ih_x1, 9);
417 			((struct ipovly *)ip)->ih_len = uh->uh_ulen;
418 			uh_sum = in_cksum(m, len + sizeof (struct ip));
419 			bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
420 		}
421 		if (uh_sum) {
422 			UDPSTAT_INC(udps_badsum);
423 			m_freem(m);
424 			return;
425 		}
426 	} else
427 		UDPSTAT_INC(udps_nosum);
428 
429 #ifdef IPFIREWALL_FORWARD
430 	/*
431 	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
432 	 */
433 	fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
434 	if (fwd_tag != NULL) {
435 		struct sockaddr_in *next_hop;
436 
437 		/*
438 		 * Do the hack.
439 		 */
440 		next_hop = (struct sockaddr_in *)(fwd_tag + 1);
441 		ip->ip_dst = next_hop->sin_addr;
442 		uh->uh_dport = ntohs(next_hop->sin_port);
443 
444 		/*
445 		 * Remove the tag from the packet.  We don't need it anymore.
446 		 */
447 		m_tag_delete(m, fwd_tag);
448 	}
449 #endif
450 
451 	INP_INFO_RLOCK(&V_udbinfo);
452 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
453 	    in_broadcast(ip->ip_dst, ifp)) {
454 		struct inpcb *last;
455 		struct ip_moptions *imo;
456 
457 		last = NULL;
458 		LIST_FOREACH(inp, &V_udb, inp_list) {
459 			if (inp->inp_lport != uh->uh_dport)
460 				continue;
461 #ifdef INET6
462 			if ((inp->inp_vflag & INP_IPV4) == 0)
463 				continue;
464 #endif
465 			if (inp->inp_laddr.s_addr != INADDR_ANY &&
466 			    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
467 				continue;
468 			if (inp->inp_faddr.s_addr != INADDR_ANY &&
469 			    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
470 				continue;
471 			if (inp->inp_fport != 0 &&
472 			    inp->inp_fport != uh->uh_sport)
473 				continue;
474 
475 			INP_RLOCK(inp);
476 
477 			/*
478 			 * Handle socket delivery policy for any-source
479 			 * and source-specific multicast. [RFC3678]
480 			 */
481 			imo = inp->inp_moptions;
482 			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
483 				struct sockaddr_in	 group;
484 				int			 blocked;
485 				if (imo == NULL) {
486 					INP_RUNLOCK(inp);
487 					continue;
488 				}
489 				bzero(&group, sizeof(struct sockaddr_in));
490 				group.sin_len = sizeof(struct sockaddr_in);
491 				group.sin_family = AF_INET;
492 				group.sin_addr = ip->ip_dst;
493 
494 				blocked = imo_multi_filter(imo, ifp,
495 					(struct sockaddr *)&group,
496 					(struct sockaddr *)&udp_in);
497 				if (blocked != MCAST_PASS) {
498 					if (blocked == MCAST_NOTGMEMBER)
499 						IPSTAT_INC(ips_notmember);
500 					if (blocked == MCAST_NOTSMEMBER ||
501 					    blocked == MCAST_MUTED)
502 						UDPSTAT_INC(udps_filtermcast);
503 					INP_RUNLOCK(inp);
504 					continue;
505 				}
506 			}
507 			if (last != NULL) {
508 				struct mbuf *n;
509 
510 				n = m_copy(m, 0, M_COPYALL);
511 				up = intoudpcb(last);
512 				if (up->u_tun_func == NULL) {
513 					if (n != NULL)
514 						udp_append(last,
515 						    ip, n,
516 						    iphlen +
517 						    sizeof(struct udphdr),
518 						    &udp_in);
519 				} else {
520 					/*
521 					 * Engage the tunneling protocol we
522 					 * will have to leave the info_lock
523 					 * up, since we are hunting through
524 					 * multiple UDP's.
525 					 */
526 
527 					(*up->u_tun_func)(n, iphlen, last);
528 				}
529 				INP_RUNLOCK(last);
530 			}
531 			last = inp;
532 			/*
533 			 * Don't look for additional matches if this one does
534 			 * not have either the SO_REUSEPORT or SO_REUSEADDR
535 			 * socket options set.  This heuristic avoids
536 			 * searching through all pcbs in the common case of a
537 			 * non-shared port.  It assumes that an application
538 			 * will never clear these options after setting them.
539 			 */
540 			if ((last->inp_socket->so_options &
541 			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
542 				break;
543 		}
544 
545 		if (last == NULL) {
546 			/*
547 			 * No matching pcb found; discard datagram.  (No need
548 			 * to send an ICMP Port Unreachable for a broadcast
549 			 * or multicast datgram.)
550 			 */
551 			UDPSTAT_INC(udps_noportbcast);
552 			goto badheadlocked;
553 		}
554 		up = intoudpcb(last);
555 		if (up->u_tun_func == NULL) {
556 			udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
557 			    &udp_in);
558 		} else {
559 			/*
560 			 * Engage the tunneling protocol.
561 			 */
562 			(*up->u_tun_func)(m, iphlen, last);
563 		}
564 		INP_RUNLOCK(last);
565 		INP_INFO_RUNLOCK(&V_udbinfo);
566 		return;
567 	}
568 
569 	/*
570 	 * Locate pcb for datagram.
571 	 */
572 	inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
573 	    ip->ip_dst, uh->uh_dport, 1, ifp);
574 	if (inp == NULL) {
575 		if (udp_log_in_vain) {
576 			char buf[4*sizeof "123"];
577 
578 			strcpy(buf, inet_ntoa(ip->ip_dst));
579 			log(LOG_INFO,
580 			    "Connection attempt to UDP %s:%d from %s:%d\n",
581 			    buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
582 			    ntohs(uh->uh_sport));
583 		}
584 		UDPSTAT_INC(udps_noport);
585 		if (m->m_flags & (M_BCAST | M_MCAST)) {
586 			UDPSTAT_INC(udps_noportbcast);
587 			goto badheadlocked;
588 		}
589 		if (V_udp_blackhole)
590 			goto badheadlocked;
591 		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
592 			goto badheadlocked;
593 		*ip = save_ip;
594 		ip->ip_len += iphlen;
595 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
596 		INP_INFO_RUNLOCK(&V_udbinfo);
597 		return;
598 	}
599 
600 	/*
601 	 * Check the minimum TTL for socket.
602 	 */
603 	INP_RLOCK(inp);
604 	INP_INFO_RUNLOCK(&V_udbinfo);
605 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
606 		INP_RUNLOCK(inp);
607 		goto badunlocked;
608 	}
609 	up = intoudpcb(inp);
610 	if (up->u_tun_func == NULL) {
611 		udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
612 	} else {
613 		/*
614 		 * Engage the tunneling protocol.
615 		 */
616 
617 		(*up->u_tun_func)(m, iphlen, inp);
618 	}
619 	INP_RUNLOCK(inp);
620 	return;
621 
622 badheadlocked:
623 	if (inp)
624 		INP_RUNLOCK(inp);
625 	INP_INFO_RUNLOCK(&V_udbinfo);
626 badunlocked:
627 	m_freem(m);
628 }
629 
630 /*
631  * Notify a udp user of an asynchronous error; just wake up so that they can
632  * collect error status.
633  */
634 struct inpcb *
635 udp_notify(struct inpcb *inp, int errno)
636 {
637 
638 	/*
639 	 * While udp_ctlinput() always calls udp_notify() with a read lock
640 	 * when invoking it directly, in_pcbnotifyall() currently uses write
641 	 * locks due to sharing code with TCP.  For now, accept either a read
642 	 * or a write lock, but a read lock is sufficient.
643 	 */
644 	INP_LOCK_ASSERT(inp);
645 
646 	inp->inp_socket->so_error = errno;
647 	sorwakeup(inp->inp_socket);
648 	sowwakeup(inp->inp_socket);
649 	return (inp);
650 }
651 
652 void
653 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
654 {
655 	struct ip *ip = vip;
656 	struct udphdr *uh;
657 	struct in_addr faddr;
658 	struct inpcb *inp;
659 
660 	faddr = ((struct sockaddr_in *)sa)->sin_addr;
661 	if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
662 		return;
663 
664 	/*
665 	 * Redirects don't need to be handled up here.
666 	 */
667 	if (PRC_IS_REDIRECT(cmd))
668 		return;
669 
670 	/*
671 	 * Hostdead is ugly because it goes linearly through all PCBs.
672 	 *
673 	 * XXX: We never get this from ICMP, otherwise it makes an excellent
674 	 * DoS attack on machines with many connections.
675 	 */
676 	if (cmd == PRC_HOSTDEAD)
677 		ip = NULL;
678 	else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
679 		return;
680 	if (ip != NULL) {
681 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
682 		INP_INFO_RLOCK(&V_udbinfo);
683 		inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
684 		    ip->ip_src, uh->uh_sport, 0, NULL);
685 		if (inp != NULL) {
686 			INP_RLOCK(inp);
687 			if (inp->inp_socket != NULL) {
688 				udp_notify(inp, inetctlerrmap[cmd]);
689 			}
690 			INP_RUNLOCK(inp);
691 		}
692 		INP_INFO_RUNLOCK(&V_udbinfo);
693 	} else
694 		in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
695 		    udp_notify);
696 }
697 
698 static int
699 udp_pcblist(SYSCTL_HANDLER_ARGS)
700 {
701 	int error, i, n;
702 	struct inpcb *inp, **inp_list;
703 	inp_gen_t gencnt;
704 	struct xinpgen xig;
705 
706 	/*
707 	 * The process of preparing the PCB list is too time-consuming and
708 	 * resource-intensive to repeat twice on every request.
709 	 */
710 	if (req->oldptr == 0) {
711 		n = V_udbinfo.ipi_count;
712 		n += imax(n / 8, 10);
713 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
714 		return (0);
715 	}
716 
717 	if (req->newptr != 0)
718 		return (EPERM);
719 
720 	/*
721 	 * OK, now we're committed to doing something.
722 	 */
723 	INP_INFO_RLOCK(&V_udbinfo);
724 	gencnt = V_udbinfo.ipi_gencnt;
725 	n = V_udbinfo.ipi_count;
726 	INP_INFO_RUNLOCK(&V_udbinfo);
727 
728 	error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
729 		+ n * sizeof(struct xinpcb));
730 	if (error != 0)
731 		return (error);
732 
733 	xig.xig_len = sizeof xig;
734 	xig.xig_count = n;
735 	xig.xig_gen = gencnt;
736 	xig.xig_sogen = so_gencnt;
737 	error = SYSCTL_OUT(req, &xig, sizeof xig);
738 	if (error)
739 		return (error);
740 
741 	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
742 	if (inp_list == 0)
743 		return (ENOMEM);
744 
745 	INP_INFO_RLOCK(&V_udbinfo);
746 	for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
747 	     inp = LIST_NEXT(inp, inp_list)) {
748 		INP_WLOCK(inp);
749 		if (inp->inp_gencnt <= gencnt &&
750 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
751 			in_pcbref(inp);
752 			inp_list[i++] = inp;
753 		}
754 		INP_WUNLOCK(inp);
755 	}
756 	INP_INFO_RUNLOCK(&V_udbinfo);
757 	n = i;
758 
759 	error = 0;
760 	for (i = 0; i < n; i++) {
761 		inp = inp_list[i];
762 		INP_RLOCK(inp);
763 		if (inp->inp_gencnt <= gencnt) {
764 			struct xinpcb xi;
765 
766 			bzero(&xi, sizeof(xi));
767 			xi.xi_len = sizeof xi;
768 			/* XXX should avoid extra copy */
769 			bcopy(inp, &xi.xi_inp, sizeof *inp);
770 			if (inp->inp_socket)
771 				sotoxsocket(inp->inp_socket, &xi.xi_socket);
772 			xi.xi_inp.inp_gencnt = inp->inp_gencnt;
773 			INP_RUNLOCK(inp);
774 			error = SYSCTL_OUT(req, &xi, sizeof xi);
775 		} else
776 			INP_RUNLOCK(inp);
777 	}
778 	INP_INFO_WLOCK(&V_udbinfo);
779 	for (i = 0; i < n; i++) {
780 		inp = inp_list[i];
781 		INP_WLOCK(inp);
782 		if (!in_pcbrele(inp))
783 			INP_WUNLOCK(inp);
784 	}
785 	INP_INFO_WUNLOCK(&V_udbinfo);
786 
787 	if (!error) {
788 		/*
789 		 * Give the user an updated idea of our state.  If the
790 		 * generation differs from what we told her before, she knows
791 		 * that something happened while we were processing this
792 		 * request, and it might be necessary to retry.
793 		 */
794 		INP_INFO_RLOCK(&V_udbinfo);
795 		xig.xig_gen = V_udbinfo.ipi_gencnt;
796 		xig.xig_sogen = so_gencnt;
797 		xig.xig_count = V_udbinfo.ipi_count;
798 		INP_INFO_RUNLOCK(&V_udbinfo);
799 		error = SYSCTL_OUT(req, &xig, sizeof xig);
800 	}
801 	free(inp_list, M_TEMP);
802 	return (error);
803 }
804 
805 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
806     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
807     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
808 
809 static int
810 udp_getcred(SYSCTL_HANDLER_ARGS)
811 {
812 	struct xucred xuc;
813 	struct sockaddr_in addrs[2];
814 	struct inpcb *inp;
815 	int error;
816 
817 	error = priv_check(req->td, PRIV_NETINET_GETCRED);
818 	if (error)
819 		return (error);
820 	error = SYSCTL_IN(req, addrs, sizeof(addrs));
821 	if (error)
822 		return (error);
823 	INP_INFO_RLOCK(&V_udbinfo);
824 	inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
825 				addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
826 	if (inp != NULL) {
827 		INP_RLOCK(inp);
828 		INP_INFO_RUNLOCK(&V_udbinfo);
829 		if (inp->inp_socket == NULL)
830 			error = ENOENT;
831 		if (error == 0)
832 			error = cr_canseeinpcb(req->td->td_ucred, inp);
833 		if (error == 0)
834 			cru2x(inp->inp_cred, &xuc);
835 		INP_RUNLOCK(inp);
836 	} else {
837 		INP_INFO_RUNLOCK(&V_udbinfo);
838 		error = ENOENT;
839 	}
840 	if (error == 0)
841 		error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
842 	return (error);
843 }
844 
845 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
846     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
847     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
848 
849 int
850 udp_ctloutput(struct socket *so, struct sockopt *sopt)
851 {
852 	int error = 0, optval;
853 	struct inpcb *inp;
854 #ifdef IPSEC_NAT_T
855 	struct udpcb *up;
856 #endif
857 
858 	inp = sotoinpcb(so);
859 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
860 	INP_WLOCK(inp);
861 	if (sopt->sopt_level != IPPROTO_UDP) {
862 #ifdef INET6
863 		if (INP_CHECK_SOCKAF(so, AF_INET6)) {
864 			INP_WUNLOCK(inp);
865 			error = ip6_ctloutput(so, sopt);
866 		} else {
867 #endif
868 			INP_WUNLOCK(inp);
869 			error = ip_ctloutput(so, sopt);
870 #ifdef INET6
871 		}
872 #endif
873 		return (error);
874 	}
875 
876 	switch (sopt->sopt_dir) {
877 	case SOPT_SET:
878 		switch (sopt->sopt_name) {
879 		case UDP_ENCAP:
880 			INP_WUNLOCK(inp);
881 			error = sooptcopyin(sopt, &optval, sizeof optval,
882 					    sizeof optval);
883 			if (error)
884 				break;
885 			inp = sotoinpcb(so);
886 			KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
887 			INP_WLOCK(inp);
888 #ifdef IPSEC_NAT_T
889 			up = intoudpcb(inp);
890 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
891 #endif
892 			switch (optval) {
893 			case 0:
894 				/* Clear all UDP encap. */
895 #ifdef IPSEC_NAT_T
896 				up->u_flags &= ~UF_ESPINUDP_ALL;
897 #endif
898 				break;
899 #ifdef IPSEC_NAT_T
900 			case UDP_ENCAP_ESPINUDP:
901 			case UDP_ENCAP_ESPINUDP_NON_IKE:
902 				up->u_flags &= ~UF_ESPINUDP_ALL;
903 				if (optval == UDP_ENCAP_ESPINUDP)
904 					up->u_flags |= UF_ESPINUDP;
905 				else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
906 					up->u_flags |= UF_ESPINUDP_NON_IKE;
907 				break;
908 #endif
909 			default:
910 				error = EINVAL;
911 				break;
912 			}
913 			INP_WUNLOCK(inp);
914 			break;
915 		default:
916 			INP_WUNLOCK(inp);
917 			error = ENOPROTOOPT;
918 			break;
919 		}
920 		break;
921 	case SOPT_GET:
922 		switch (sopt->sopt_name) {
923 #ifdef IPSEC_NAT_T
924 		case UDP_ENCAP:
925 			up = intoudpcb(inp);
926 			KASSERT(up != NULL, ("%s: up == NULL", __func__));
927 			optval = up->u_flags & UF_ESPINUDP_ALL;
928 			INP_WUNLOCK(inp);
929 			error = sooptcopyout(sopt, &optval, sizeof optval);
930 			break;
931 #endif
932 		default:
933 			INP_WUNLOCK(inp);
934 			error = ENOPROTOOPT;
935 			break;
936 		}
937 		break;
938 	}
939 	return (error);
940 }
941 
942 static int
943 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
944     struct mbuf *control, struct thread *td)
945 {
946 	struct udpiphdr *ui;
947 	int len = m->m_pkthdr.len;
948 	struct in_addr faddr, laddr;
949 	struct cmsghdr *cm;
950 	struct sockaddr_in *sin, src;
951 	int error = 0;
952 	int ipflags;
953 	u_short fport, lport;
954 	int unlock_udbinfo;
955 
956 	/*
957 	 * udp_output() may need to temporarily bind or connect the current
958 	 * inpcb.  As such, we don't know up front whether we will need the
959 	 * pcbinfo lock or not.  Do any work to decide what is needed up
960 	 * front before acquiring any locks.
961 	 */
962 	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
963 		if (control)
964 			m_freem(control);
965 		m_freem(m);
966 		return (EMSGSIZE);
967 	}
968 
969 	src.sin_family = 0;
970 	if (control != NULL) {
971 		/*
972 		 * XXX: Currently, we assume all the optional information is
973 		 * stored in a single mbuf.
974 		 */
975 		if (control->m_next) {
976 			m_freem(control);
977 			m_freem(m);
978 			return (EINVAL);
979 		}
980 		for (; control->m_len > 0;
981 		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
982 		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
983 			cm = mtod(control, struct cmsghdr *);
984 			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
985 			    || cm->cmsg_len > control->m_len) {
986 				error = EINVAL;
987 				break;
988 			}
989 			if (cm->cmsg_level != IPPROTO_IP)
990 				continue;
991 
992 			switch (cm->cmsg_type) {
993 			case IP_SENDSRCADDR:
994 				if (cm->cmsg_len !=
995 				    CMSG_LEN(sizeof(struct in_addr))) {
996 					error = EINVAL;
997 					break;
998 				}
999 				bzero(&src, sizeof(src));
1000 				src.sin_family = AF_INET;
1001 				src.sin_len = sizeof(src);
1002 				src.sin_port = inp->inp_lport;
1003 				src.sin_addr =
1004 				    *(struct in_addr *)CMSG_DATA(cm);
1005 				break;
1006 
1007 			default:
1008 				error = ENOPROTOOPT;
1009 				break;
1010 			}
1011 			if (error)
1012 				break;
1013 		}
1014 		m_freem(control);
1015 	}
1016 	if (error) {
1017 		m_freem(m);
1018 		return (error);
1019 	}
1020 
1021 	/*
1022 	 * Depending on whether or not the application has bound or connected
1023 	 * the socket, we may have to do varying levels of work.  The optimal
1024 	 * case is for a connected UDP socket, as a global lock isn't
1025 	 * required at all.
1026 	 *
1027 	 * In order to decide which we need, we require stability of the
1028 	 * inpcb binding, which we ensure by acquiring a read lock on the
1029 	 * inpcb.  This doesn't strictly follow the lock order, so we play
1030 	 * the trylock and retry game; note that we may end up with more
1031 	 * conservative locks than required the second time around, so later
1032 	 * assertions have to accept that.  Further analysis of the number of
1033 	 * misses under contention is required.
1034 	 */
1035 	sin = (struct sockaddr_in *)addr;
1036 	INP_RLOCK(inp);
1037 	if (sin != NULL &&
1038 	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1039 		INP_RUNLOCK(inp);
1040 		INP_INFO_WLOCK(&V_udbinfo);
1041 		INP_WLOCK(inp);
1042 		unlock_udbinfo = 2;
1043 	} else if ((sin != NULL && (
1044 	    (sin->sin_addr.s_addr == INADDR_ANY) ||
1045 	    (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1046 	    (inp->inp_laddr.s_addr == INADDR_ANY) ||
1047 	    (inp->inp_lport == 0))) ||
1048 	    (src.sin_family == AF_INET)) {
1049 		if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
1050 			INP_RUNLOCK(inp);
1051 			INP_INFO_RLOCK(&V_udbinfo);
1052 			INP_RLOCK(inp);
1053 		}
1054 		unlock_udbinfo = 1;
1055 	} else
1056 		unlock_udbinfo = 0;
1057 
1058 	/*
1059 	 * If the IP_SENDSRCADDR control message was specified, override the
1060 	 * source address for this datagram.  Its use is invalidated if the
1061 	 * address thus specified is incomplete or clobbers other inpcbs.
1062 	 */
1063 	laddr = inp->inp_laddr;
1064 	lport = inp->inp_lport;
1065 	if (src.sin_family == AF_INET) {
1066 		INP_INFO_LOCK_ASSERT(&V_udbinfo);
1067 		if ((lport == 0) ||
1068 		    (laddr.s_addr == INADDR_ANY &&
1069 		     src.sin_addr.s_addr == INADDR_ANY)) {
1070 			error = EINVAL;
1071 			goto release;
1072 		}
1073 		error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1074 		    &laddr.s_addr, &lport, td->td_ucred);
1075 		if (error)
1076 			goto release;
1077 	}
1078 
1079 	/*
1080 	 * If a UDP socket has been connected, then a local address/port will
1081 	 * have been selected and bound.
1082 	 *
1083 	 * If a UDP socket has not been connected to, then an explicit
1084 	 * destination address must be used, in which case a local
1085 	 * address/port may not have been selected and bound.
1086 	 */
1087 	if (sin != NULL) {
1088 		INP_LOCK_ASSERT(inp);
1089 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
1090 			error = EISCONN;
1091 			goto release;
1092 		}
1093 
1094 		/*
1095 		 * Jail may rewrite the destination address, so let it do
1096 		 * that before we use it.
1097 		 */
1098 		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1099 		if (error)
1100 			goto release;
1101 
1102 		/*
1103 		 * If a local address or port hasn't yet been selected, or if
1104 		 * the destination address needs to be rewritten due to using
1105 		 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1106 		 * to do the heavy lifting.  Once a port is selected, we
1107 		 * commit the binding back to the socket; we also commit the
1108 		 * binding of the address if in jail.
1109 		 *
1110 		 * If we already have a valid binding and we're not
1111 		 * requesting a destination address rewrite, use a fast path.
1112 		 */
1113 		if (inp->inp_laddr.s_addr == INADDR_ANY ||
1114 		    inp->inp_lport == 0 ||
1115 		    sin->sin_addr.s_addr == INADDR_ANY ||
1116 		    sin->sin_addr.s_addr == INADDR_BROADCAST) {
1117 			INP_INFO_LOCK_ASSERT(&V_udbinfo);
1118 			error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1119 			    &lport, &faddr.s_addr, &fport, NULL,
1120 			    td->td_ucred);
1121 			if (error)
1122 				goto release;
1123 
1124 			/*
1125 			 * XXXRW: Why not commit the port if the address is
1126 			 * !INADDR_ANY?
1127 			 */
1128 			/* Commit the local port if newly assigned. */
1129 			if (inp->inp_laddr.s_addr == INADDR_ANY &&
1130 			    inp->inp_lport == 0) {
1131 				INP_INFO_WLOCK_ASSERT(&V_udbinfo);
1132 				INP_WLOCK_ASSERT(inp);
1133 				/*
1134 				 * Remember addr if jailed, to prevent
1135 				 * rebinding.
1136 				 */
1137 				if (prison_flag(td->td_ucred, PR_IP4))
1138 					inp->inp_laddr = laddr;
1139 				inp->inp_lport = lport;
1140 				if (in_pcbinshash(inp) != 0) {
1141 					inp->inp_lport = 0;
1142 					error = EAGAIN;
1143 					goto release;
1144 				}
1145 				inp->inp_flags |= INP_ANONPORT;
1146 			}
1147 		} else {
1148 			faddr = sin->sin_addr;
1149 			fport = sin->sin_port;
1150 		}
1151 	} else {
1152 		INP_LOCK_ASSERT(inp);
1153 		faddr = inp->inp_faddr;
1154 		fport = inp->inp_fport;
1155 		if (faddr.s_addr == INADDR_ANY) {
1156 			error = ENOTCONN;
1157 			goto release;
1158 		}
1159 	}
1160 
1161 	/*
1162 	 * Calculate data length and get a mbuf for UDP, IP, and possible
1163 	 * link-layer headers.  Immediate slide the data pointer back forward
1164 	 * since we won't use that space at this layer.
1165 	 */
1166 	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1167 	if (m == NULL) {
1168 		error = ENOBUFS;
1169 		goto release;
1170 	}
1171 	m->m_data += max_linkhdr;
1172 	m->m_len -= max_linkhdr;
1173 	m->m_pkthdr.len -= max_linkhdr;
1174 
1175 	/*
1176 	 * Fill in mbuf with extended UDP header and addresses and length put
1177 	 * into network format.
1178 	 */
1179 	ui = mtod(m, struct udpiphdr *);
1180 	bzero(ui->ui_x1, sizeof(ui->ui_x1));	/* XXX still needed? */
1181 	ui->ui_pr = IPPROTO_UDP;
1182 	ui->ui_src = laddr;
1183 	ui->ui_dst = faddr;
1184 	ui->ui_sport = lport;
1185 	ui->ui_dport = fport;
1186 	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1187 
1188 	/*
1189 	 * Set the Don't Fragment bit in the IP header.
1190 	 */
1191 	if (inp->inp_flags & INP_DONTFRAG) {
1192 		struct ip *ip;
1193 
1194 		ip = (struct ip *)&ui->ui_i;
1195 		ip->ip_off |= IP_DF;
1196 	}
1197 
1198 	ipflags = 0;
1199 	if (inp->inp_socket->so_options & SO_DONTROUTE)
1200 		ipflags |= IP_ROUTETOIF;
1201 	if (inp->inp_socket->so_options & SO_BROADCAST)
1202 		ipflags |= IP_ALLOWBROADCAST;
1203 	if (inp->inp_flags & INP_ONESBCAST)
1204 		ipflags |= IP_SENDONES;
1205 
1206 #ifdef MAC
1207 	mac_inpcb_create_mbuf(inp, m);
1208 #endif
1209 
1210 	/*
1211 	 * Set up checksum and output datagram.
1212 	 */
1213 	if (udp_cksum) {
1214 		if (inp->inp_flags & INP_ONESBCAST)
1215 			faddr.s_addr = INADDR_BROADCAST;
1216 		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1217 		    htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1218 		m->m_pkthdr.csum_flags = CSUM_UDP;
1219 		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1220 	} else
1221 		ui->ui_sum = 0;
1222 	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1223 	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
1224 	((struct ip *)ui)->ip_tos = inp->inp_ip_tos;	/* XXX */
1225 	UDPSTAT_INC(udps_opackets);
1226 
1227 	if (unlock_udbinfo == 2)
1228 		INP_INFO_WUNLOCK(&V_udbinfo);
1229 	else if (unlock_udbinfo == 1)
1230 		INP_INFO_RUNLOCK(&V_udbinfo);
1231 	error = ip_output(m, inp->inp_options, NULL, ipflags,
1232 	    inp->inp_moptions, inp);
1233 	if (unlock_udbinfo == 2)
1234 		INP_WUNLOCK(inp);
1235 	else
1236 		INP_RUNLOCK(inp);
1237 	return (error);
1238 
1239 release:
1240 	if (unlock_udbinfo == 2) {
1241 		INP_WUNLOCK(inp);
1242 		INP_INFO_WUNLOCK(&V_udbinfo);
1243 	} else if (unlock_udbinfo == 1) {
1244 		INP_RUNLOCK(inp);
1245 		INP_INFO_RUNLOCK(&V_udbinfo);
1246 	} else
1247 		INP_RUNLOCK(inp);
1248 	m_freem(m);
1249 	return (error);
1250 }
1251 
1252 
1253 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1254 #ifdef INET
1255 /*
1256  * Potentially decap ESP in UDP frame.  Check for an ESP header
1257  * and optional marker; if present, strip the UDP header and
1258  * push the result through IPSec.
1259  *
1260  * Returns mbuf to be processed (potentially re-allocated) or
1261  * NULL if consumed and/or processed.
1262  */
1263 static struct mbuf *
1264 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1265 {
1266 	size_t minlen, payload, skip, iphlen;
1267 	caddr_t data;
1268 	struct udpcb *up;
1269 	struct m_tag *tag;
1270 	struct udphdr *udphdr;
1271 	struct ip *ip;
1272 
1273 	INP_RLOCK_ASSERT(inp);
1274 
1275 	/*
1276 	 * Pull up data so the longest case is contiguous:
1277 	 *    IP/UDP hdr + non ESP marker + ESP hdr.
1278 	 */
1279 	minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1280 	if (minlen > m->m_pkthdr.len)
1281 		minlen = m->m_pkthdr.len;
1282 	if ((m = m_pullup(m, minlen)) == NULL) {
1283 		V_ipsec4stat.in_inval++;
1284 		return (NULL);		/* Bypass caller processing. */
1285 	}
1286 	data = mtod(m, caddr_t);	/* Points to ip header. */
1287 	payload = m->m_len - off;	/* Size of payload. */
1288 
1289 	if (payload == 1 && data[off] == '\xff')
1290 		return (m);		/* NB: keepalive packet, no decap. */
1291 
1292 	up = intoudpcb(inp);
1293 	KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1294 	KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1295 	    ("u_flags 0x%x", up->u_flags));
1296 
1297 	/*
1298 	 * Check that the payload is large enough to hold an
1299 	 * ESP header and compute the amount of data to remove.
1300 	 *
1301 	 * NB: the caller has already done a pullup for us.
1302 	 * XXX can we assume alignment and eliminate bcopys?
1303 	 */
1304 	if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1305 		/*
1306 		 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1307 		 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1308 		 * possible AH mode non-IKE marker+non-ESP marker
1309 		 * from draft-ietf-ipsec-udp-encaps-00.txt.
1310 		 */
1311 		uint64_t marker;
1312 
1313 		if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1314 			return (m);	/* NB: no decap. */
1315 		bcopy(data + off, &marker, sizeof(uint64_t));
1316 		if (marker != 0)	/* Non-IKE marker. */
1317 			return (m);	/* NB: no decap. */
1318 		skip = sizeof(uint64_t) + sizeof(struct udphdr);
1319 	} else {
1320 		uint32_t spi;
1321 
1322 		if (payload <= sizeof(struct esp)) {
1323 			V_ipsec4stat.in_inval++;
1324 			m_freem(m);
1325 			return (NULL);	/* Discard. */
1326 		}
1327 		bcopy(data + off, &spi, sizeof(uint32_t));
1328 		if (spi == 0)		/* Non-ESP marker. */
1329 			return (m);	/* NB: no decap. */
1330 		skip = sizeof(struct udphdr);
1331 	}
1332 
1333 	/*
1334 	 * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1335 	 * the UDP ports. This is required if we want to select
1336 	 * the right SPD for multiple hosts behind same NAT.
1337 	 *
1338 	 * NB: ports are maintained in network byte order everywhere
1339 	 *     in the NAT-T code.
1340 	 */
1341 	tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1342 		2 * sizeof(uint16_t), M_NOWAIT);
1343 	if (tag == NULL) {
1344 		V_ipsec4stat.in_nomem++;
1345 		m_freem(m);
1346 		return (NULL);		/* Discard. */
1347 	}
1348 	iphlen = off - sizeof(struct udphdr);
1349 	udphdr = (struct udphdr *)(data + iphlen);
1350 	((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1351 	((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1352 	m_tag_prepend(m, tag);
1353 
1354 	/*
1355 	 * Remove the UDP header (and possibly the non ESP marker)
1356 	 * IP header length is iphlen
1357 	 * Before:
1358 	 *   <--- off --->
1359 	 *   +----+------+-----+
1360 	 *   | IP |  UDP | ESP |
1361 	 *   +----+------+-----+
1362 	 *        <-skip->
1363 	 * After:
1364 	 *          +----+-----+
1365 	 *          | IP | ESP |
1366 	 *          +----+-----+
1367 	 *   <-skip->
1368 	 */
1369 	ovbcopy(data, data + skip, iphlen);
1370 	m_adj(m, skip);
1371 
1372 	ip = mtod(m, struct ip *);
1373 	ip->ip_len -= skip;
1374 	ip->ip_p = IPPROTO_ESP;
1375 
1376 	/*
1377 	 * We cannot yet update the cksums so clear any
1378 	 * h/w cksum flags as they are no longer valid.
1379 	 */
1380 	if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1381 		m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1382 
1383 	(void) ipsec4_common_input(m, iphlen, ip->ip_p);
1384 	return (NULL);			/* NB: consumed, bypass processing. */
1385 }
1386 #endif /* INET */
1387 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1388 
1389 static void
1390 udp_abort(struct socket *so)
1391 {
1392 	struct inpcb *inp;
1393 
1394 	inp = sotoinpcb(so);
1395 	KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1396 	INP_INFO_WLOCK(&V_udbinfo);
1397 	INP_WLOCK(inp);
1398 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1399 		in_pcbdisconnect(inp);
1400 		inp->inp_laddr.s_addr = INADDR_ANY;
1401 		soisdisconnected(so);
1402 	}
1403 	INP_WUNLOCK(inp);
1404 	INP_INFO_WUNLOCK(&V_udbinfo);
1405 }
1406 
1407 static int
1408 udp_attach(struct socket *so, int proto, struct thread *td)
1409 {
1410 	struct inpcb *inp;
1411 	int error;
1412 
1413 	inp = sotoinpcb(so);
1414 	KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1415 	error = soreserve(so, udp_sendspace, udp_recvspace);
1416 	if (error)
1417 		return (error);
1418 	INP_INFO_WLOCK(&V_udbinfo);
1419 	error = in_pcballoc(so, &V_udbinfo);
1420 	if (error) {
1421 		INP_INFO_WUNLOCK(&V_udbinfo);
1422 		return (error);
1423 	}
1424 
1425 	inp = sotoinpcb(so);
1426 	inp->inp_vflag |= INP_IPV4;
1427 	inp->inp_ip_ttl = V_ip_defttl;
1428 
1429 	error = udp_newudpcb(inp);
1430 	if (error) {
1431 		in_pcbdetach(inp);
1432 		in_pcbfree(inp);
1433 		INP_INFO_WUNLOCK(&V_udbinfo);
1434 		return (error);
1435 	}
1436 
1437 	INP_WUNLOCK(inp);
1438 	INP_INFO_WUNLOCK(&V_udbinfo);
1439 	return (0);
1440 }
1441 
1442 int
1443 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1444 {
1445 	struct inpcb *inp;
1446 	struct udpcb *up;
1447 
1448 	KASSERT(so->so_type == SOCK_DGRAM,
1449 	    ("udp_set_kernel_tunneling: !dgram"));
1450 	inp = sotoinpcb(so);
1451 	KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1452 	INP_WLOCK(inp);
1453 	up = intoudpcb(inp);
1454 	if (up->u_tun_func != NULL) {
1455 		INP_WUNLOCK(inp);
1456 		return (EBUSY);
1457 	}
1458 	up->u_tun_func = f;
1459 	INP_WUNLOCK(inp);
1460 	return (0);
1461 }
1462 
1463 static int
1464 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1465 {
1466 	struct inpcb *inp;
1467 	int error;
1468 
1469 	inp = sotoinpcb(so);
1470 	KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1471 	INP_INFO_WLOCK(&V_udbinfo);
1472 	INP_WLOCK(inp);
1473 	error = in_pcbbind(inp, nam, td->td_ucred);
1474 	INP_WUNLOCK(inp);
1475 	INP_INFO_WUNLOCK(&V_udbinfo);
1476 	return (error);
1477 }
1478 
1479 static void
1480 udp_close(struct socket *so)
1481 {
1482 	struct inpcb *inp;
1483 
1484 	inp = sotoinpcb(so);
1485 	KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1486 	INP_INFO_WLOCK(&V_udbinfo);
1487 	INP_WLOCK(inp);
1488 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1489 		in_pcbdisconnect(inp);
1490 		inp->inp_laddr.s_addr = INADDR_ANY;
1491 		soisdisconnected(so);
1492 	}
1493 	INP_WUNLOCK(inp);
1494 	INP_INFO_WUNLOCK(&V_udbinfo);
1495 }
1496 
1497 static int
1498 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1499 {
1500 	struct inpcb *inp;
1501 	int error;
1502 	struct sockaddr_in *sin;
1503 
1504 	inp = sotoinpcb(so);
1505 	KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1506 	INP_INFO_WLOCK(&V_udbinfo);
1507 	INP_WLOCK(inp);
1508 	if (inp->inp_faddr.s_addr != INADDR_ANY) {
1509 		INP_WUNLOCK(inp);
1510 		INP_INFO_WUNLOCK(&V_udbinfo);
1511 		return (EISCONN);
1512 	}
1513 	sin = (struct sockaddr_in *)nam;
1514 	error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1515 	if (error != 0) {
1516 		INP_WUNLOCK(inp);
1517 		INP_INFO_WUNLOCK(&V_udbinfo);
1518 		return (error);
1519 	}
1520 	error = in_pcbconnect(inp, nam, td->td_ucred);
1521 	if (error == 0)
1522 		soisconnected(so);
1523 	INP_WUNLOCK(inp);
1524 	INP_INFO_WUNLOCK(&V_udbinfo);
1525 	return (error);
1526 }
1527 
1528 static void
1529 udp_detach(struct socket *so)
1530 {
1531 	struct inpcb *inp;
1532 	struct udpcb *up;
1533 
1534 	inp = sotoinpcb(so);
1535 	KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1536 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1537 	    ("udp_detach: not disconnected"));
1538 	INP_INFO_WLOCK(&V_udbinfo);
1539 	INP_WLOCK(inp);
1540 	up = intoudpcb(inp);
1541 	KASSERT(up != NULL, ("%s: up == NULL", __func__));
1542 	inp->inp_ppcb = NULL;
1543 	in_pcbdetach(inp);
1544 	in_pcbfree(inp);
1545 	INP_INFO_WUNLOCK(&V_udbinfo);
1546 	udp_discardcb(up);
1547 }
1548 
1549 static int
1550 udp_disconnect(struct socket *so)
1551 {
1552 	struct inpcb *inp;
1553 
1554 	inp = sotoinpcb(so);
1555 	KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1556 	INP_INFO_WLOCK(&V_udbinfo);
1557 	INP_WLOCK(inp);
1558 	if (inp->inp_faddr.s_addr == INADDR_ANY) {
1559 		INP_WUNLOCK(inp);
1560 		INP_INFO_WUNLOCK(&V_udbinfo);
1561 		return (ENOTCONN);
1562 	}
1563 
1564 	in_pcbdisconnect(inp);
1565 	inp->inp_laddr.s_addr = INADDR_ANY;
1566 	SOCK_LOCK(so);
1567 	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
1568 	SOCK_UNLOCK(so);
1569 	INP_WUNLOCK(inp);
1570 	INP_INFO_WUNLOCK(&V_udbinfo);
1571 	return (0);
1572 }
1573 
1574 static int
1575 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1576     struct mbuf *control, struct thread *td)
1577 {
1578 	struct inpcb *inp;
1579 
1580 	inp = sotoinpcb(so);
1581 	KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1582 	return (udp_output(inp, m, addr, control, td));
1583 }
1584 
1585 int
1586 udp_shutdown(struct socket *so)
1587 {
1588 	struct inpcb *inp;
1589 
1590 	inp = sotoinpcb(so);
1591 	KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1592 	INP_WLOCK(inp);
1593 	socantsendmore(so);
1594 	INP_WUNLOCK(inp);
1595 	return (0);
1596 }
1597 
1598 struct pr_usrreqs udp_usrreqs = {
1599 	.pru_abort =		udp_abort,
1600 	.pru_attach =		udp_attach,
1601 	.pru_bind =		udp_bind,
1602 	.pru_connect =		udp_connect,
1603 	.pru_control =		in_control,
1604 	.pru_detach =		udp_detach,
1605 	.pru_disconnect =	udp_disconnect,
1606 	.pru_peeraddr =		in_getpeeraddr,
1607 	.pru_send =		udp_send,
1608 	.pru_soreceive =	soreceive_dgram,
1609 	.pru_sosend =		sosend_dgram,
1610 	.pru_shutdown =		udp_shutdown,
1611 	.pru_sockaddr =		in_getsockaddr,
1612 	.pru_sosetlabel =	in_pcbsosetlabel,
1613 	.pru_close =		udp_close,
1614 };
1615