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 * Copyright (c) 2010-2011 Juniper Networks, Inc.
6 * All rights reserved.
7 *
8 * Portions of this software were developed by Robert N. M. Watson under
9 * contract to Juniper Networks, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)udp_usrreq.c 8.6 (Berkeley) 5/23/95
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/netinet/udp_usrreq.c 252026 2013-06-20 09:55:53Z ae $");
40
41#include "opt_ipfw.h"
42#include "opt_inet.h"
43#include "opt_inet6.h"
44#include "opt_ipsec.h"
45
46#include <sys/param.h>
47#include <sys/domain.h>
48#include <sys/eventhandler.h>
49#include <sys/jail.h>
50#include <sys/kernel.h>
51#include <sys/lock.h>
52#include <sys/malloc.h>
53#include <sys/mbuf.h>
54#include <sys/priv.h>
55#include <sys/proc.h>
56#include <sys/protosw.h>
57#include <sys/signalvar.h>
58#include <sys/socket.h>
59#include <sys/socketvar.h>
60#include <sys/sx.h>
61#include <sys/sysctl.h>
62#include <sys/syslog.h>
63#include <sys/systm.h>
64
65#include <vm/uma.h>
66
67#include <net/if.h>
68#include <net/route.h>
69
70#include <netinet/in.h>
71#include <netinet/in_pcb.h>
72#include <netinet/in_systm.h>
73#include <netinet/in_var.h>
74#include <netinet/ip.h>
75#ifdef INET6
76#include <netinet/ip6.h>
77#endif
78#include <netinet/ip_icmp.h>
79#include <netinet/icmp_var.h>
80#include <netinet/ip_var.h>
81#include <netinet/ip_options.h>
82#ifdef INET6
83#include <netinet6/ip6_var.h>
84#endif
85#include <netinet/udp.h>
86#include <netinet/udp_var.h>
87
88#ifdef IPSEC
89#include <netipsec/ipsec.h>
90#include <netipsec/esp.h>
91#endif
92
93#include <machine/in_cksum.h>
94
95#include <security/mac/mac_framework.h>
96
97/*
98 * UDP protocol implementation.
99 * Per RFC 768, August, 1980.
100 */
101
102/*
103 * BSD 4.2 defaulted the udp checksum to be off. Turning off udp checksums
104 * removes the only data integrity mechanism for packets and malformed
105 * packets that would otherwise be discarded due to bad checksums, and may
106 * cause problems (especially for NFS data blocks).
107 */
108VNET_DEFINE(int, udp_cksum) = 1;
109SYSCTL_VNET_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
110 &VNET_NAME(udp_cksum), 0, "compute udp checksum");
111
112int udp_log_in_vain = 0;
113SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
114 &udp_log_in_vain, 0, "Log all incoming UDP packets");
115
116VNET_DEFINE(int, udp_blackhole) = 0;
117SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
118 &VNET_NAME(udp_blackhole), 0,
119 "Do not send port unreachables for refused connects");
120
121u_long udp_sendspace = 9216; /* really max datagram size */
122 /* 40 1K datagrams */
123SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
124 &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
125
126u_long udp_recvspace = 40 * (1024 +
127#ifdef INET6
128 sizeof(struct sockaddr_in6)
129#else
130 sizeof(struct sockaddr_in)
131#endif
132 );
133
134SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
135 &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
136
137VNET_DEFINE(struct inpcbhead, udb); /* from udp_var.h */
138VNET_DEFINE(struct inpcbinfo, udbinfo);
139static VNET_DEFINE(uma_zone_t, udpcb_zone);
140#define V_udpcb_zone VNET(udpcb_zone)
141
142#ifndef UDBHASHSIZE
143#define UDBHASHSIZE 128
144#endif
145
146VNET_DEFINE(struct udpstat, udpstat); /* from udp_var.h */
147SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
148 &VNET_NAME(udpstat), udpstat,
149 "UDP statistics (struct udpstat, netinet/udp_var.h)");
150
151#ifdef INET
152static void udp_detach(struct socket *so);
153static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
154 struct mbuf *, struct thread *);
155#endif
156
157#ifdef IPSEC
158#ifdef IPSEC_NAT_T
159#define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
160#ifdef INET
161static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
162#endif
163#endif /* IPSEC_NAT_T */
164#endif /* IPSEC */
165
166static void
167udp_zone_change(void *tag)
168{
169
170 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
171 uma_zone_set_max(V_udpcb_zone, maxsockets);
172}
173
174static int
175udp_inpcb_init(void *mem, int size, int flags)
176{
177 struct inpcb *inp;
178
179 inp = mem;
180 INP_LOCK_INIT(inp, "inp", "udpinp");
181 return (0);
182}
183
184void
185udp_init(void)
186{
187
188 in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
189 "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE,
190 IPI_HASHFIELDS_2TUPLE);
191 V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
192 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
193 uma_zone_set_max(V_udpcb_zone, maxsockets);
194 uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
195 EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
196 EVENTHANDLER_PRI_ANY);
197}
198
199/*
200 * Kernel module interface for updating udpstat. The argument is an index
201 * into udpstat treated as an array of u_long. While this encodes the
202 * general layout of udpstat into the caller, it doesn't encode its location,
203 * so that future changes to add, for example, per-CPU stats support won't
204 * cause binary compatibility problems for kernel modules.
205 */
206void
207kmod_udpstat_inc(int statnum)
208{
209
210 (*((u_long *)&V_udpstat + statnum))++;
211}
212
213int
214udp_newudpcb(struct inpcb *inp)
215{
216 struct udpcb *up;
217
218 up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
219 if (up == NULL)
220 return (ENOBUFS);
221 inp->inp_ppcb = up;
222 return (0);
223}
224
225void
226udp_discardcb(struct udpcb *up)
227{
228
229 uma_zfree(V_udpcb_zone, up);
230}
231
232#ifdef VIMAGE
233void
234udp_destroy(void)
235{
236
237 in_pcbinfo_destroy(&V_udbinfo);
238 uma_zdestroy(V_udpcb_zone);
239}
240#endif
241
242#ifdef INET
243/*
244 * Subroutine of udp_input(), which appends the provided mbuf chain to the
245 * passed pcb/socket. The caller must provide a sockaddr_in via udp_in that
246 * contains the source address. If the socket ends up being an IPv6 socket,
247 * udp_append() will convert to a sockaddr_in6 before passing the address
248 * into the socket code.
249 */
250static void
251udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
252 struct sockaddr_in *udp_in)
253{
254 struct sockaddr *append_sa;
255 struct socket *so;
256 struct mbuf *opts = 0;
257#ifdef INET6
258 struct sockaddr_in6 udp_in6;
259#endif
260 struct udpcb *up;
261
262 INP_LOCK_ASSERT(inp);
263
264 /*
265 * Engage the tunneling protocol.
266 */
267 up = intoudpcb(inp);
268 if (up->u_tun_func != NULL) {
269 (*up->u_tun_func)(n, off, inp);
270 return;
271 }
272
273 if (n == NULL)
274 return;
275
276 off += sizeof(struct udphdr);
277
278#ifdef IPSEC
279 /* Check AH/ESP integrity. */
280 if (ipsec4_in_reject(n, inp)) {
281 m_freem(n);
282 IPSECSTAT_INC(in_polvio);
283 return;
284 }
285#ifdef IPSEC_NAT_T
286 up = intoudpcb(inp);
287 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
288 if (up->u_flags & UF_ESPINUDP_ALL) { /* IPSec UDP encaps. */
289 n = udp4_espdecap(inp, n, off);
290 if (n == NULL) /* Consumed. */
291 return;
292 }
293#endif /* IPSEC_NAT_T */
294#endif /* IPSEC */
295#ifdef MAC
296 if (mac_inpcb_check_deliver(inp, n) != 0) {
297 m_freem(n);
298 return;
299 }
300#endif /* MAC */
301 if (inp->inp_flags & INP_CONTROLOPTS ||
302 inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
303#ifdef INET6
304 if (inp->inp_vflag & INP_IPV6)
305 (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
306 else
307#endif /* INET6 */
308 ip_savecontrol(inp, &opts, ip, n);
309 }
310#ifdef INET6
311 if (inp->inp_vflag & INP_IPV6) {
312 bzero(&udp_in6, sizeof(udp_in6));
313 udp_in6.sin6_len = sizeof(udp_in6);
314 udp_in6.sin6_family = AF_INET6;
315 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
316 append_sa = (struct sockaddr *)&udp_in6;
317 } else
318#endif /* INET6 */
319 append_sa = (struct sockaddr *)udp_in;
320 m_adj(n, off);
321
322 so = inp->inp_socket;
323 SOCKBUF_LOCK(&so->so_rcv);
324 if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
325 SOCKBUF_UNLOCK(&so->so_rcv);
326 m_freem(n);
327 if (opts)
328 m_freem(opts);
329 UDPSTAT_INC(udps_fullsock);
330 } else
331 sorwakeup_locked(so);
332}
333
334void
335udp_input(struct mbuf *m, int off)
336{
337 int iphlen = off;
338 struct ip *ip;
339 struct udphdr *uh;
340 struct ifnet *ifp;
341 struct inpcb *inp;
342 uint16_t len, ip_len;
343 struct ip save_ip;
344 struct sockaddr_in udp_in;
345 struct m_tag *fwd_tag;
346
347 ifp = m->m_pkthdr.rcvif;
348 UDPSTAT_INC(udps_ipackets);
349
350 /*
351 * Strip IP options, if any; should skip this, make available to
352 * user, and use on returned packets, but we don't yet have a way to
353 * check the checksum with options still present.
354 */
355 if (iphlen > sizeof (struct ip)) {
356 ip_stripoptions(m);
357 iphlen = sizeof(struct ip);
358 }
359
360 /*
361 * Get IP and UDP header together in first mbuf.
362 */
363 ip = mtod(m, struct ip *);
364 if (m->m_len < iphlen + sizeof(struct udphdr)) {
365 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
366 UDPSTAT_INC(udps_hdrops);
367 return;
368 }
369 ip = mtod(m, struct ip *);
370 }
371 uh = (struct udphdr *)((caddr_t)ip + iphlen);
372
373 /*
374 * Destination port of 0 is illegal, based on RFC768.
375 */
376 if (uh->uh_dport == 0)
377 goto badunlocked;
378
379 /*
380 * Construct sockaddr format source address. Stuff source address
381 * and datagram in user buffer.
382 */
383 bzero(&udp_in, sizeof(udp_in));
384 udp_in.sin_len = sizeof(udp_in);
385 udp_in.sin_family = AF_INET;
386 udp_in.sin_port = uh->uh_sport;
387 udp_in.sin_addr = ip->ip_src;
388
389 /*
390 * Make mbuf data length reflect UDP length. If not enough data to
391 * reflect UDP length, drop.
392 */
393 len = ntohs((u_short)uh->uh_ulen);
394 ip_len = ntohs(ip->ip_len) - iphlen;
395 if (ip_len != len) {
396 if (len > ip_len || len < sizeof(struct udphdr)) {
397 UDPSTAT_INC(udps_badlen);
398 goto badunlocked;
399 }
400 m_adj(m, len - ip_len);
401 }
402
403 /*
404 * Save a copy of the IP header in case we want restore it for
405 * sending an ICMP error message in response.
406 */
407 if (!V_udp_blackhole)
408 save_ip = *ip;
409 else
410 memset(&save_ip, 0, sizeof(save_ip));
411
412 /*
413 * Checksum extended UDP header and data.
414 */
415 if (uh->uh_sum) {
416 u_short uh_sum;
417
418 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
419 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
420 uh_sum = m->m_pkthdr.csum_data;
421 else
422 uh_sum = in_pseudo(ip->ip_src.s_addr,
423 ip->ip_dst.s_addr, htonl((u_short)len +
424 m->m_pkthdr.csum_data + IPPROTO_UDP));
425 uh_sum ^= 0xffff;
426 } else {
427 char b[9];
428
429 bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
430 bzero(((struct ipovly *)ip)->ih_x1, 9);
431 ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
432 uh_sum = in_cksum(m, len + sizeof (struct ip));
433 bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
434 }
435 if (uh_sum) {
436 UDPSTAT_INC(udps_badsum);
437 m_freem(m);
438 return;
439 }
440 } else
441 UDPSTAT_INC(udps_nosum);
442
443 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
444 in_broadcast(ip->ip_dst, ifp)) {
445 struct inpcb *last;
446 struct ip_moptions *imo;
447
448 INP_INFO_RLOCK(&V_udbinfo);
449 last = NULL;
450 LIST_FOREACH(inp, &V_udb, inp_list) {
451 if (inp->inp_lport != uh->uh_dport)
452 continue;
453#ifdef INET6
454 if ((inp->inp_vflag & INP_IPV4) == 0)
455 continue;
456#endif
457 if (inp->inp_laddr.s_addr != INADDR_ANY &&
458 inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
459 continue;
460 if (inp->inp_faddr.s_addr != INADDR_ANY &&
461 inp->inp_faddr.s_addr != ip->ip_src.s_addr)
462 continue;
463 if (inp->inp_fport != 0 &&
464 inp->inp_fport != uh->uh_sport)
465 continue;
466
467 INP_RLOCK(inp);
468
469 /*
470 * XXXRW: Because we weren't holding either the inpcb
471 * or the hash lock when we checked for a match
472 * before, we should probably recheck now that the
473 * inpcb lock is held.
474 */
475
476 /*
477 * Handle socket delivery policy for any-source
478 * and source-specific multicast. [RFC3678]
479 */
480 imo = inp->inp_moptions;
481 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
482 struct sockaddr_in group;
483 int blocked;
484 if (imo == NULL) {
485 INP_RUNLOCK(inp);
486 continue;
487 }
488 bzero(&group, sizeof(struct sockaddr_in));
489 group.sin_len = sizeof(struct sockaddr_in);
490 group.sin_family = AF_INET;
491 group.sin_addr = ip->ip_dst;
492
493 blocked = imo_multi_filter(imo, ifp,
494 (struct sockaddr *)&group,
495 (struct sockaddr *)&udp_in);
496 if (blocked != MCAST_PASS) {
497 if (blocked == MCAST_NOTGMEMBER)
498 IPSTAT_INC(ips_notmember);
499 if (blocked == MCAST_NOTSMEMBER ||
500 blocked == MCAST_MUTED)
501 UDPSTAT_INC(udps_filtermcast);
502 INP_RUNLOCK(inp);
503 continue;
504 }
505 }
506 if (last != NULL) {
507 struct mbuf *n;
508
509 n = m_copy(m, 0, M_COPYALL);
510 udp_append(last, ip, n, iphlen, &udp_in);
511 INP_RUNLOCK(last);
512 }
513 last = inp;
514 /*
515 * Don't look for additional matches if this one does
516 * not have either the SO_REUSEPORT or SO_REUSEADDR
517 * socket options set. This heuristic avoids
518 * searching through all pcbs in the common case of a
519 * non-shared port. It assumes that an application
520 * will never clear these options after setting them.
521 */
522 if ((last->inp_socket->so_options &
523 (SO_REUSEPORT|SO_REUSEADDR)) == 0)
524 break;
525 }
526
527 if (last == NULL) {
528 /*
529 * No matching pcb found; discard datagram. (No need
530 * to send an ICMP Port Unreachable for a broadcast
531 * or multicast datgram.)
532 */
533 UDPSTAT_INC(udps_noportbcast);
534 if (inp)
535 INP_RUNLOCK(inp);
536 INP_INFO_RUNLOCK(&V_udbinfo);
537 goto badunlocked;
538 }
539 udp_append(last, ip, m, iphlen, &udp_in);
540 INP_RUNLOCK(last);
541 INP_INFO_RUNLOCK(&V_udbinfo);
542 return;
543 }
544
545 /*
546 * Locate pcb for datagram.
547 */
548
549 /*
550 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
551 */
552 if ((m->m_flags & M_IP_NEXTHOP) &&
553 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
554 struct sockaddr_in *next_hop;
555
556 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
557
558 /*
559 * Transparently forwarded. Pretend to be the destination.
560 * Already got one like this?
561 */
562 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
563 ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
564 if (!inp) {
565 /*
566 * It's new. Try to find the ambushing socket.
567 * Because we've rewritten the destination address,
568 * any hardware-generated hash is ignored.
569 */
570 inp = in_pcblookup(&V_udbinfo, ip->ip_src,
571 uh->uh_sport, next_hop->sin_addr,
572 next_hop->sin_port ? htons(next_hop->sin_port) :
573 uh->uh_dport, INPLOOKUP_WILDCARD |
574 INPLOOKUP_RLOCKPCB, ifp);
575 }
576 /* Remove the tag from the packet. We don't need it anymore. */
577 m_tag_delete(m, fwd_tag);
578 m->m_flags &= ~M_IP_NEXTHOP;
579 } else
580 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
581 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
582 INPLOOKUP_RLOCKPCB, ifp, m);
583 if (inp == NULL) {
584 if (udp_log_in_vain) {
585 char buf[4*sizeof "123"];
586
587 strcpy(buf, inet_ntoa(ip->ip_dst));
588 log(LOG_INFO,
589 "Connection attempt to UDP %s:%d from %s:%d\n",
590 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
591 ntohs(uh->uh_sport));
592 }
593 UDPSTAT_INC(udps_noport);
594 if (m->m_flags & (M_BCAST | M_MCAST)) {
595 UDPSTAT_INC(udps_noportbcast);
596 goto badunlocked;
597 }
598 if (V_udp_blackhole)
599 goto badunlocked;
600 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
601 goto badunlocked;
602 *ip = save_ip;
603 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
604 return;
605 }
606
607 /*
608 * Check the minimum TTL for socket.
609 */
610 INP_RLOCK_ASSERT(inp);
611 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
612 INP_RUNLOCK(inp);
613 m_freem(m);
614 return;
615 }
616 udp_append(inp, ip, m, iphlen, &udp_in);
617 INP_RUNLOCK(inp);
618 return;
619
620badunlocked:
621 m_freem(m);
622}
623#endif /* INET */
624
625/*
626 * Notify a udp user of an asynchronous error; just wake up so that they can
627 * collect error status.
628 */
629struct inpcb *
630udp_notify(struct inpcb *inp, int errno)
631{
632
633 /*
634 * While udp_ctlinput() always calls udp_notify() with a read lock
635 * when invoking it directly, in_pcbnotifyall() currently uses write
636 * locks due to sharing code with TCP. For now, accept either a read
637 * or a write lock, but a read lock is sufficient.
638 */
639 INP_LOCK_ASSERT(inp);
640
641 inp->inp_socket->so_error = errno;
642 sorwakeup(inp->inp_socket);
643 sowwakeup(inp->inp_socket);
644 return (inp);
645}
646
647#ifdef INET
648void
649udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
650{
651 struct ip *ip = vip;
652 struct udphdr *uh;
653 struct in_addr faddr;
654 struct inpcb *inp;
655
656 faddr = ((struct sockaddr_in *)sa)->sin_addr;
657 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
658 return;
659
660 /*
661 * Redirects don't need to be handled up here.
662 */
663 if (PRC_IS_REDIRECT(cmd))
664 return;
665
666 /*
667 * Hostdead is ugly because it goes linearly through all PCBs.
668 *
669 * XXX: We never get this from ICMP, otherwise it makes an excellent
670 * DoS attack on machines with many connections.
671 */
672 if (cmd == PRC_HOSTDEAD)
673 ip = NULL;
674 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
675 return;
676 if (ip != NULL) {
677 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
678 inp = in_pcblookup(&V_udbinfo, faddr, uh->uh_dport,
679 ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
680 if (inp != NULL) {
681 INP_RLOCK_ASSERT(inp);
682 if (inp->inp_socket != NULL) {
683 udp_notify(inp, inetctlerrmap[cmd]);
684 }
685 INP_RUNLOCK(inp);
686 }
687 } else
688 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
689 udp_notify);
690}
691#endif /* INET */
692
693static int
694udp_pcblist(SYSCTL_HANDLER_ARGS)
695{
696 int error, i, n;
697 struct inpcb *inp, **inp_list;
698 inp_gen_t gencnt;
699 struct xinpgen xig;
700
701 /*
702 * The process of preparing the PCB list is too time-consuming and
703 * resource-intensive to repeat twice on every request.
704 */
705 if (req->oldptr == 0) {
706 n = V_udbinfo.ipi_count;
707 n += imax(n / 8, 10);
708 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
709 return (0);
710 }
711
712 if (req->newptr != 0)
713 return (EPERM);
714
715 /*
716 * OK, now we're committed to doing something.
717 */
718 INP_INFO_RLOCK(&V_udbinfo);
719 gencnt = V_udbinfo.ipi_gencnt;
720 n = V_udbinfo.ipi_count;
721 INP_INFO_RUNLOCK(&V_udbinfo);
722
723 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
724 + n * sizeof(struct xinpcb));
725 if (error != 0)
726 return (error);
727
728 xig.xig_len = sizeof xig;
729 xig.xig_count = n;
730 xig.xig_gen = gencnt;
731 xig.xig_sogen = so_gencnt;
732 error = SYSCTL_OUT(req, &xig, sizeof xig);
733 if (error)
734 return (error);
735
736 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
737 if (inp_list == 0)
738 return (ENOMEM);
739
740 INP_INFO_RLOCK(&V_udbinfo);
741 for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
742 inp = LIST_NEXT(inp, inp_list)) {
743 INP_WLOCK(inp);
744 if (inp->inp_gencnt <= gencnt &&
745 cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
746 in_pcbref(inp);
747 inp_list[i++] = inp;
748 }
749 INP_WUNLOCK(inp);
750 }
751 INP_INFO_RUNLOCK(&V_udbinfo);
752 n = i;
753
754 error = 0;
755 for (i = 0; i < n; i++) {
756 inp = inp_list[i];
757 INP_RLOCK(inp);
758 if (inp->inp_gencnt <= gencnt) {
759 struct xinpcb xi;
760
761 bzero(&xi, sizeof(xi));
762 xi.xi_len = sizeof xi;
763 /* XXX should avoid extra copy */
764 bcopy(inp, &xi.xi_inp, sizeof *inp);
765 if (inp->inp_socket)
766 sotoxsocket(inp->inp_socket, &xi.xi_socket);
767 xi.xi_inp.inp_gencnt = inp->inp_gencnt;
768 INP_RUNLOCK(inp);
769 error = SYSCTL_OUT(req, &xi, sizeof xi);
770 } else
771 INP_RUNLOCK(inp);
772 }
773 INP_INFO_WLOCK(&V_udbinfo);
774 for (i = 0; i < n; i++) {
775 inp = inp_list[i];
776 INP_RLOCK(inp);
777 if (!in_pcbrele_rlocked(inp))
778 INP_RUNLOCK(inp);
779 }
780 INP_INFO_WUNLOCK(&V_udbinfo);
781
782 if (!error) {
783 /*
784 * Give the user an updated idea of our state. If the
785 * generation differs from what we told her before, she knows
786 * that something happened while we were processing this
787 * request, and it might be necessary to retry.
788 */
789 INP_INFO_RLOCK(&V_udbinfo);
790 xig.xig_gen = V_udbinfo.ipi_gencnt;
791 xig.xig_sogen = so_gencnt;
792 xig.xig_count = V_udbinfo.ipi_count;
793 INP_INFO_RUNLOCK(&V_udbinfo);
794 error = SYSCTL_OUT(req, &xig, sizeof xig);
795 }
796 free(inp_list, M_TEMP);
797 return (error);
798}
799
800SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
801 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
802 udp_pcblist, "S,xinpcb", "List of active UDP sockets");
803
804#ifdef INET
805static int
806udp_getcred(SYSCTL_HANDLER_ARGS)
807{
808 struct xucred xuc;
809 struct sockaddr_in addrs[2];
810 struct inpcb *inp;
811 int error;
812
813 error = priv_check(req->td, PRIV_NETINET_GETCRED);
814 if (error)
815 return (error);
816 error = SYSCTL_IN(req, addrs, sizeof(addrs));
817 if (error)
818 return (error);
819 inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
820 addrs[0].sin_addr, addrs[0].sin_port,
821 INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
822 if (inp != NULL) {
823 INP_RLOCK_ASSERT(inp);
824 if (inp->inp_socket == NULL)
825 error = ENOENT;
826 if (error == 0)
827 error = cr_canseeinpcb(req->td->td_ucred, inp);
828 if (error == 0)
829 cru2x(inp->inp_cred, &xuc);
830 INP_RUNLOCK(inp);
831 } else
832 error = ENOENT;
833 if (error == 0)
834 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
835 return (error);
836}
837
838SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
839 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
840 udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
841#endif /* INET */
842
843int
844udp_ctloutput(struct socket *so, struct sockopt *sopt)
845{
846 int error = 0, optval;
847 struct inpcb *inp;
848#ifdef IPSEC_NAT_T
849 struct udpcb *up;
850#endif
851
852 inp = sotoinpcb(so);
853 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
854 INP_WLOCK(inp);
855 if (sopt->sopt_level != IPPROTO_UDP) {
856#ifdef INET6
857 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
858 INP_WUNLOCK(inp);
859 error = ip6_ctloutput(so, sopt);
860 }
861#endif
862#if defined(INET) && defined(INET6)
863 else
864#endif
865#ifdef INET
866 {
867 INP_WUNLOCK(inp);
868 error = ip_ctloutput(so, sopt);
869 }
870#endif
871 return (error);
872 }
873
874 switch (sopt->sopt_dir) {
875 case SOPT_SET:
876 switch (sopt->sopt_name) {
877 case UDP_ENCAP:
878 INP_WUNLOCK(inp);
879 error = sooptcopyin(sopt, &optval, sizeof optval,
880 sizeof optval);
881 if (error)
882 break;
883 inp = sotoinpcb(so);
884 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
885 INP_WLOCK(inp);
886#ifdef IPSEC_NAT_T
887 up = intoudpcb(inp);
888 KASSERT(up != NULL, ("%s: up == NULL", __func__));
889#endif
890 switch (optval) {
891 case 0:
892 /* Clear all UDP encap. */
893#ifdef IPSEC_NAT_T
894 up->u_flags &= ~UF_ESPINUDP_ALL;
895#endif
896 break;
897#ifdef IPSEC_NAT_T
898 case UDP_ENCAP_ESPINUDP:
899 case UDP_ENCAP_ESPINUDP_NON_IKE:
900 up->u_flags &= ~UF_ESPINUDP_ALL;
901 if (optval == UDP_ENCAP_ESPINUDP)
902 up->u_flags |= UF_ESPINUDP;
903 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
904 up->u_flags |= UF_ESPINUDP_NON_IKE;
905 break;
906#endif
907 default:
908 error = EINVAL;
909 break;
910 }
911 INP_WUNLOCK(inp);
912 break;
913 default:
914 INP_WUNLOCK(inp);
915 error = ENOPROTOOPT;
916 break;
917 }
918 break;
919 case SOPT_GET:
920 switch (sopt->sopt_name) {
921#ifdef IPSEC_NAT_T
922 case UDP_ENCAP:
923 up = intoudpcb(inp);
924 KASSERT(up != NULL, ("%s: up == NULL", __func__));
925 optval = up->u_flags & UF_ESPINUDP_ALL;
926 INP_WUNLOCK(inp);
927 error = sooptcopyout(sopt, &optval, sizeof optval);
928 break;
929#endif
930 default:
931 INP_WUNLOCK(inp);
932 error = ENOPROTOOPT;
933 break;
934 }
935 break;
936 }
937 return (error);
938}
939
940#ifdef INET
941#define UH_WLOCKED 2
942#define UH_RLOCKED 1
943#define UH_UNLOCKED 0
944static int
945udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
946 struct mbuf *control, struct thread *td)
947{
948 struct udpiphdr *ui;
949 int len = m->m_pkthdr.len;
950 struct in_addr faddr, laddr;
951 struct cmsghdr *cm;
952 struct sockaddr_in *sin, src;
953 int error = 0;
954 int ipflags;
955 u_short fport, lport;
956 int unlock_udbinfo;
957 u_char tos;
958
959 /*
960 * udp_output() may need to temporarily bind or connect the current
961 * inpcb. As such, we don't know up front whether we will need the
962 * pcbinfo lock or not. Do any work to decide what is needed up
963 * front before acquiring any locks.
964 */
965 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
966 if (control)
967 m_freem(control);
968 m_freem(m);
969 return (EMSGSIZE);
970 }
971
972 src.sin_family = 0;
973 INP_RLOCK(inp);
974 tos = inp->inp_ip_tos;
975 if (control != NULL) {
976 /*
977 * XXX: Currently, we assume all the optional information is
978 * stored in a single mbuf.
979 */
980 if (control->m_next) {
981 INP_RUNLOCK(inp);
982 m_freem(control);
983 m_freem(m);
984 return (EINVAL);
985 }
986 for (; control->m_len > 0;
987 control->m_data += CMSG_ALIGN(cm->cmsg_len),
988 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
989 cm = mtod(control, struct cmsghdr *);
990 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
991 || cm->cmsg_len > control->m_len) {
992 error = EINVAL;
993 break;
994 }
995 if (cm->cmsg_level != IPPROTO_IP)
996 continue;
997
998 switch (cm->cmsg_type) {
999 case IP_SENDSRCADDR:
1000 if (cm->cmsg_len !=
1001 CMSG_LEN(sizeof(struct in_addr))) {
1002 error = EINVAL;
1003 break;
1004 }
1005 bzero(&src, sizeof(src));
1006 src.sin_family = AF_INET;
1007 src.sin_len = sizeof(src);
1008 src.sin_port = inp->inp_lport;
1009 src.sin_addr =
1010 *(struct in_addr *)CMSG_DATA(cm);
1011 break;
1012
1013 case IP_TOS:
1014 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1015 error = EINVAL;
1016 break;
1017 }
1018 tos = *(u_char *)CMSG_DATA(cm);
1019 break;
1020
1021 default:
1022 error = ENOPROTOOPT;
1023 break;
1024 }
1025 if (error)
1026 break;
1027 }
1028 m_freem(control);
1029 }
1030 if (error) {
1031 INP_RUNLOCK(inp);
1032 m_freem(m);
1033 return (error);
1034 }
1035
1036 /*
1037 * Depending on whether or not the application has bound or connected
1038 * the socket, we may have to do varying levels of work. The optimal
1039 * case is for a connected UDP socket, as a global lock isn't
1040 * required at all.
1041 *
1042 * In order to decide which we need, we require stability of the
1043 * inpcb binding, which we ensure by acquiring a read lock on the
1044 * inpcb. This doesn't strictly follow the lock order, so we play
1045 * the trylock and retry game; note that we may end up with more
1046 * conservative locks than required the second time around, so later
1047 * assertions have to accept that. Further analysis of the number of
1048 * misses under contention is required.
1049 *
1050 * XXXRW: Check that hash locking update here is correct.
1051 */
1052 sin = (struct sockaddr_in *)addr;
1053 if (sin != NULL &&
1054 (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1055 INP_RUNLOCK(inp);
1056 INP_WLOCK(inp);
1057 INP_HASH_WLOCK(&V_udbinfo);
1058 unlock_udbinfo = UH_WLOCKED;
1059 } else if ((sin != NULL && (
1060 (sin->sin_addr.s_addr == INADDR_ANY) ||
1061 (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1062 (inp->inp_laddr.s_addr == INADDR_ANY) ||
1063 (inp->inp_lport == 0))) ||
1064 (src.sin_family == AF_INET)) {
1065 INP_HASH_RLOCK(&V_udbinfo);
1066 unlock_udbinfo = UH_RLOCKED;
1067 } else
1068 unlock_udbinfo = UH_UNLOCKED;
1069
1070 /*
1071 * If the IP_SENDSRCADDR control message was specified, override the
1072 * source address for this datagram. Its use is invalidated if the
1073 * address thus specified is incomplete or clobbers other inpcbs.
1074 */
1075 laddr = inp->inp_laddr;
1076 lport = inp->inp_lport;
1077 if (src.sin_family == AF_INET) {
1078 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1079 if ((lport == 0) ||
1080 (laddr.s_addr == INADDR_ANY &&
1081 src.sin_addr.s_addr == INADDR_ANY)) {
1082 error = EINVAL;
1083 goto release;
1084 }
1085 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1086 &laddr.s_addr, &lport, td->td_ucred);
1087 if (error)
1088 goto release;
1089 }
1090
1091 /*
1092 * If a UDP socket has been connected, then a local address/port will
1093 * have been selected and bound.
1094 *
1095 * If a UDP socket has not been connected to, then an explicit
1096 * destination address must be used, in which case a local
1097 * address/port may not have been selected and bound.
1098 */
1099 if (sin != NULL) {
1100 INP_LOCK_ASSERT(inp);
1101 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1102 error = EISCONN;
1103 goto release;
1104 }
1105
1106 /*
1107 * Jail may rewrite the destination address, so let it do
1108 * that before we use it.
1109 */
1110 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1111 if (error)
1112 goto release;
1113
1114 /*
1115 * If a local address or port hasn't yet been selected, or if
1116 * the destination address needs to be rewritten due to using
1117 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1118 * to do the heavy lifting. Once a port is selected, we
1119 * commit the binding back to the socket; we also commit the
1120 * binding of the address if in jail.
1121 *
1122 * If we already have a valid binding and we're not
1123 * requesting a destination address rewrite, use a fast path.
1124 */
1125 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1126 inp->inp_lport == 0 ||
1127 sin->sin_addr.s_addr == INADDR_ANY ||
1128 sin->sin_addr.s_addr == INADDR_BROADCAST) {
1129 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1130 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1131 &lport, &faddr.s_addr, &fport, NULL,
1132 td->td_ucred);
1133 if (error)
1134 goto release;
1135
1136 /*
1137 * XXXRW: Why not commit the port if the address is
1138 * !INADDR_ANY?
1139 */
1140 /* Commit the local port if newly assigned. */
1141 if (inp->inp_laddr.s_addr == INADDR_ANY &&
1142 inp->inp_lport == 0) {
1143 INP_WLOCK_ASSERT(inp);
1144 INP_HASH_WLOCK_ASSERT(&V_udbinfo);
1145 /*
1146 * Remember addr if jailed, to prevent
1147 * rebinding.
1148 */
1149 if (prison_flag(td->td_ucred, PR_IP4))
1150 inp->inp_laddr = laddr;
1151 inp->inp_lport = lport;
1152 if (in_pcbinshash(inp) != 0) {
1153 inp->inp_lport = 0;
1154 error = EAGAIN;
1155 goto release;
1156 }
1157 inp->inp_flags |= INP_ANONPORT;
1158 }
1159 } else {
1160 faddr = sin->sin_addr;
1161 fport = sin->sin_port;
1162 }
1163 } else {
1164 INP_LOCK_ASSERT(inp);
1165 faddr = inp->inp_faddr;
1166 fport = inp->inp_fport;
1167 if (faddr.s_addr == INADDR_ANY) {
1168 error = ENOTCONN;
1169 goto release;
1170 }
1171 }
1172
1173 /*
1174 * Calculate data length and get a mbuf for UDP, IP, and possible
1175 * link-layer headers. Immediate slide the data pointer back forward
1176 * since we won't use that space at this layer.
1177 */
1178 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1179 if (m == NULL) {
1180 error = ENOBUFS;
1181 goto release;
1182 }
1183 m->m_data += max_linkhdr;
1184 m->m_len -= max_linkhdr;
1185 m->m_pkthdr.len -= max_linkhdr;
1186
1187 /*
1188 * Fill in mbuf with extended UDP header and addresses and length put
1189 * into network format.
1190 */
1191 ui = mtod(m, struct udpiphdr *);
1192 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */
1193 ui->ui_pr = IPPROTO_UDP;
1194 ui->ui_src = laddr;
1195 ui->ui_dst = faddr;
1196 ui->ui_sport = lport;
1197 ui->ui_dport = fport;
1198 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1199
1200 /*
1201 * Set the Don't Fragment bit in the IP header.
1202 */
1203 if (inp->inp_flags & INP_DONTFRAG) {
1204 struct ip *ip;
1205
1206 ip = (struct ip *)&ui->ui_i;
1207 ip->ip_off |= htons(IP_DF);
1208 }
1209
1210 ipflags = 0;
1211 if (inp->inp_socket->so_options & SO_DONTROUTE)
1212 ipflags |= IP_ROUTETOIF;
1213 if (inp->inp_socket->so_options & SO_BROADCAST)
1214 ipflags |= IP_ALLOWBROADCAST;
1215 if (inp->inp_flags & INP_ONESBCAST)
1216 ipflags |= IP_SENDONES;
1217
1218#ifdef MAC
1219 mac_inpcb_create_mbuf(inp, m);
1220#endif
1221
1222 /*
1223 * Set up checksum and output datagram.
1224 */
1225 if (V_udp_cksum) {
1226 if (inp->inp_flags & INP_ONESBCAST)
1227 faddr.s_addr = INADDR_BROADCAST;
1228 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1229 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1230 m->m_pkthdr.csum_flags = CSUM_UDP;
1231 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1232 } else
1233 ui->ui_sum = 0;
1234 ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1235 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
1236 ((struct ip *)ui)->ip_tos = tos; /* XXX */
1237 UDPSTAT_INC(udps_opackets);
1238
1239 if (unlock_udbinfo == UH_WLOCKED)
1240 INP_HASH_WUNLOCK(&V_udbinfo);
1241 else if (unlock_udbinfo == UH_RLOCKED)
1242 INP_HASH_RUNLOCK(&V_udbinfo);
1243 error = ip_output(m, inp->inp_options, NULL, ipflags,
1244 inp->inp_moptions, inp);
1245 if (unlock_udbinfo == UH_WLOCKED)
1246 INP_WUNLOCK(inp);
1247 else
1248 INP_RUNLOCK(inp);
1249 return (error);
1250
1251release:
1252 if (unlock_udbinfo == UH_WLOCKED) {
1253 INP_HASH_WUNLOCK(&V_udbinfo);
1254 INP_WUNLOCK(inp);
1255 } else if (unlock_udbinfo == UH_RLOCKED) {
1256 INP_HASH_RUNLOCK(&V_udbinfo);
1257 INP_RUNLOCK(inp);
1258 } else
1259 INP_RUNLOCK(inp);
1260 m_freem(m);
1261 return (error);
1262}
1263
1264
1265#if defined(IPSEC) && defined(IPSEC_NAT_T)
1266/*
1267 * Potentially decap ESP in UDP frame. Check for an ESP header
1268 * and optional marker; if present, strip the UDP header and
1269 * push the result through IPSec.
1270 *
1271 * Returns mbuf to be processed (potentially re-allocated) or
1272 * NULL if consumed and/or processed.
1273 */
1274static struct mbuf *
1275udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1276{
1277 size_t minlen, payload, skip, iphlen;
1278 caddr_t data;
1279 struct udpcb *up;
1280 struct m_tag *tag;
1281 struct udphdr *udphdr;
1282 struct ip *ip;
1283
1284 INP_RLOCK_ASSERT(inp);
1285
1286 /*
1287 * Pull up data so the longest case is contiguous:
1288 * IP/UDP hdr + non ESP marker + ESP hdr.
1289 */
1290 minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1291 if (minlen > m->m_pkthdr.len)
1292 minlen = m->m_pkthdr.len;
1293 if ((m = m_pullup(m, minlen)) == NULL) {
1294 IPSECSTAT_INC(in_inval);
1295 return (NULL); /* Bypass caller processing. */
1296 }
1297 data = mtod(m, caddr_t); /* Points to ip header. */
1298 payload = m->m_len - off; /* Size of payload. */
1299
1300 if (payload == 1 && data[off] == '\xff')
1301 return (m); /* NB: keepalive packet, no decap. */
1302
1303 up = intoudpcb(inp);
1304 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1305 KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1306 ("u_flags 0x%x", up->u_flags));
1307
1308 /*
1309 * Check that the payload is large enough to hold an
1310 * ESP header and compute the amount of data to remove.
1311 *
1312 * NB: the caller has already done a pullup for us.
1313 * XXX can we assume alignment and eliminate bcopys?
1314 */
1315 if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1316 /*
1317 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1318 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1319 * possible AH mode non-IKE marker+non-ESP marker
1320 * from draft-ietf-ipsec-udp-encaps-00.txt.
1321 */
1322 uint64_t marker;
1323
1324 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1325 return (m); /* NB: no decap. */
1326 bcopy(data + off, &marker, sizeof(uint64_t));
1327 if (marker != 0) /* Non-IKE marker. */
1328 return (m); /* NB: no decap. */
1329 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1330 } else {
1331 uint32_t spi;
1332
1333 if (payload <= sizeof(struct esp)) {
1334 IPSECSTAT_INC(in_inval);
1335 m_freem(m);
1336 return (NULL); /* Discard. */
1337 }
1338 bcopy(data + off, &spi, sizeof(uint32_t));
1339 if (spi == 0) /* Non-ESP marker. */
1340 return (m); /* NB: no decap. */
1341 skip = sizeof(struct udphdr);
1342 }
1343
1344 /*
1345 * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1346 * the UDP ports. This is required if we want to select
1347 * the right SPD for multiple hosts behind same NAT.
1348 *
1349 * NB: ports are maintained in network byte order everywhere
1350 * in the NAT-T code.
1351 */
1352 tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1353 2 * sizeof(uint16_t), M_NOWAIT);
1354 if (tag == NULL) {
1355 IPSECSTAT_INC(in_nomem);
1356 m_freem(m);
1357 return (NULL); /* Discard. */
1358 }
1359 iphlen = off - sizeof(struct udphdr);
1360 udphdr = (struct udphdr *)(data + iphlen);
1361 ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1362 ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1363 m_tag_prepend(m, tag);
1364
1365 /*
1366 * Remove the UDP header (and possibly the non ESP marker)
1367 * IP header length is iphlen
1368 * Before:
1369 * <--- off --->
1370 * +----+------+-----+
1371 * | IP | UDP | ESP |
1372 * +----+------+-----+
1373 * <-skip->
1374 * After:
1375 * +----+-----+
1376 * | IP | ESP |
1377 * +----+-----+
1378 * <-skip->
1379 */
1380 ovbcopy(data, data + skip, iphlen);
1381 m_adj(m, skip);
1382
1383 ip = mtod(m, struct ip *);
1384 ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1385 ip->ip_p = IPPROTO_ESP;
1386
1387 /*
1388 * We cannot yet update the cksums so clear any
1389 * h/w cksum flags as they are no longer valid.
1390 */
1391 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1392 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1393
1394 (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1395 return (NULL); /* NB: consumed, bypass processing. */
1396}
1397#endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1398
1399static void
1400udp_abort(struct socket *so)
1401{
1402 struct inpcb *inp;
1403
1404 inp = sotoinpcb(so);
1405 KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1406 INP_WLOCK(inp);
1407 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1408 INP_HASH_WLOCK(&V_udbinfo);
1409 in_pcbdisconnect(inp);
1410 inp->inp_laddr.s_addr = INADDR_ANY;
1411 INP_HASH_WUNLOCK(&V_udbinfo);
1412 soisdisconnected(so);
1413 }
1414 INP_WUNLOCK(inp);
1415}
1416
1417static int
1418udp_attach(struct socket *so, int proto, struct thread *td)
1419{
1420 struct inpcb *inp;
1421 int error;
1422
1423 inp = sotoinpcb(so);
1424 KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1425 error = soreserve(so, udp_sendspace, udp_recvspace);
1426 if (error)
1427 return (error);
1428 INP_INFO_WLOCK(&V_udbinfo);
1429 error = in_pcballoc(so, &V_udbinfo);
1430 if (error) {
1431 INP_INFO_WUNLOCK(&V_udbinfo);
1432 return (error);
1433 }
1434
1435 inp = sotoinpcb(so);
1436 inp->inp_vflag |= INP_IPV4;
1437 inp->inp_ip_ttl = V_ip_defttl;
1438
1439 error = udp_newudpcb(inp);
1440 if (error) {
1441 in_pcbdetach(inp);
1442 in_pcbfree(inp);
1443 INP_INFO_WUNLOCK(&V_udbinfo);
1444 return (error);
1445 }
1446
1447 INP_WUNLOCK(inp);
1448 INP_INFO_WUNLOCK(&V_udbinfo);
1449 return (0);
1450}
1451#endif /* INET */
1452
1453int
1454udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1455{
1456 struct inpcb *inp;
1457 struct udpcb *up;
1458
1459 KASSERT(so->so_type == SOCK_DGRAM,
1460 ("udp_set_kernel_tunneling: !dgram"));
1461 inp = sotoinpcb(so);
1462 KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1463 INP_WLOCK(inp);
1464 up = intoudpcb(inp);
1465 if (up->u_tun_func != NULL) {
1466 INP_WUNLOCK(inp);
1467 return (EBUSY);
1468 }
1469 up->u_tun_func = f;
1470 INP_WUNLOCK(inp);
1471 return (0);
1472}
1473
1474#ifdef INET
1475static int
1476udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1477{
1478 struct inpcb *inp;
1479 int error;
1480
1481 inp = sotoinpcb(so);
1482 KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1483 INP_WLOCK(inp);
1484 INP_HASH_WLOCK(&V_udbinfo);
1485 error = in_pcbbind(inp, nam, td->td_ucred);
1486 INP_HASH_WUNLOCK(&V_udbinfo);
1487 INP_WUNLOCK(inp);
1488 return (error);
1489}
1490
1491static void
1492udp_close(struct socket *so)
1493{
1494 struct inpcb *inp;
1495
1496 inp = sotoinpcb(so);
1497 KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1498 INP_WLOCK(inp);
1499 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1500 INP_HASH_WLOCK(&V_udbinfo);
1501 in_pcbdisconnect(inp);
1502 inp->inp_laddr.s_addr = INADDR_ANY;
1503 INP_HASH_WUNLOCK(&V_udbinfo);
1504 soisdisconnected(so);
1505 }
1506 INP_WUNLOCK(inp);
1507}
1508
1509static int
1510udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1511{
1512 struct inpcb *inp;
1513 int error;
1514 struct sockaddr_in *sin;
1515
1516 inp = sotoinpcb(so);
1517 KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1518 INP_WLOCK(inp);
1519 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1520 INP_WUNLOCK(inp);
1521 return (EISCONN);
1522 }
1523 sin = (struct sockaddr_in *)nam;
1524 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1525 if (error != 0) {
1526 INP_WUNLOCK(inp);
1527 return (error);
1528 }
1529 INP_HASH_WLOCK(&V_udbinfo);
1530 error = in_pcbconnect(inp, nam, td->td_ucred);
1531 INP_HASH_WUNLOCK(&V_udbinfo);
1532 if (error == 0)
1533 soisconnected(so);
1534 INP_WUNLOCK(inp);
1535 return (error);
1536}
1537
1538static void
1539udp_detach(struct socket *so)
1540{
1541 struct inpcb *inp;
1542 struct udpcb *up;
1543
1544 inp = sotoinpcb(so);
1545 KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1546 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1547 ("udp_detach: not disconnected"));
1548 INP_INFO_WLOCK(&V_udbinfo);
1549 INP_WLOCK(inp);
1550 up = intoudpcb(inp);
1551 KASSERT(up != NULL, ("%s: up == NULL", __func__));
1552 inp->inp_ppcb = NULL;
1553 in_pcbdetach(inp);
1554 in_pcbfree(inp);
1555 INP_INFO_WUNLOCK(&V_udbinfo);
1556 udp_discardcb(up);
1557}
1558
1559static int
1560udp_disconnect(struct socket *so)
1561{
1562 struct inpcb *inp;
1563
1564 inp = sotoinpcb(so);
1565 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1566 INP_WLOCK(inp);
1567 if (inp->inp_faddr.s_addr == INADDR_ANY) {
1568 INP_WUNLOCK(inp);
1569 return (ENOTCONN);
1570 }
1571 INP_HASH_WLOCK(&V_udbinfo);
1572 in_pcbdisconnect(inp);
1573 inp->inp_laddr.s_addr = INADDR_ANY;
1574 INP_HASH_WUNLOCK(&V_udbinfo);
1575 SOCK_LOCK(so);
1576 so->so_state &= ~SS_ISCONNECTED; /* XXX */
1577 SOCK_UNLOCK(so);
1578 INP_WUNLOCK(inp);
1579 return (0);
1580}
1581
1582static int
1583udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1584 struct mbuf *control, struct thread *td)
1585{
1586 struct inpcb *inp;
1587
1588 inp = sotoinpcb(so);
1589 KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1590 return (udp_output(inp, m, addr, control, td));
1591}
1592#endif /* INET */
1593
1594int
1595udp_shutdown(struct socket *so)
1596{
1597 struct inpcb *inp;
1598
1599 inp = sotoinpcb(so);
1600 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1601 INP_WLOCK(inp);
1602 socantsendmore(so);
1603 INP_WUNLOCK(inp);
1604 return (0);
1605}
1606
1607#ifdef INET
1608struct pr_usrreqs udp_usrreqs = {
1609 .pru_abort = udp_abort,
1610 .pru_attach = udp_attach,
1611 .pru_bind = udp_bind,
1612 .pru_connect = udp_connect,
1613 .pru_control = in_control,
1614 .pru_detach = udp_detach,
1615 .pru_disconnect = udp_disconnect,
1616 .pru_peeraddr = in_getpeeraddr,
1617 .pru_send = udp_send,
1618 .pru_soreceive = soreceive_dgram,
1619 .pru_sosend = sosend_dgram,
1620 .pru_shutdown = udp_shutdown,
1621 .pru_sockaddr = in_getsockaddr,
1622 .pru_sosetlabel = in_pcbsosetlabel,
1623 .pru_close = udp_close,
1624};
1625#endif /* INET */
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 * Copyright (c) 2010-2011 Juniper Networks, Inc.
6 * All rights reserved.
7 *
8 * Portions of this software were developed by Robert N. M. Watson under
9 * contract to Juniper Networks, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)udp_usrreq.c 8.6 (Berkeley) 5/23/95
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/netinet/udp_usrreq.c 252026 2013-06-20 09:55:53Z ae $");
40
41#include "opt_ipfw.h"
42#include "opt_inet.h"
43#include "opt_inet6.h"
44#include "opt_ipsec.h"
45
46#include <sys/param.h>
47#include <sys/domain.h>
48#include <sys/eventhandler.h>
49#include <sys/jail.h>
50#include <sys/kernel.h>
51#include <sys/lock.h>
52#include <sys/malloc.h>
53#include <sys/mbuf.h>
54#include <sys/priv.h>
55#include <sys/proc.h>
56#include <sys/protosw.h>
57#include <sys/signalvar.h>
58#include <sys/socket.h>
59#include <sys/socketvar.h>
60#include <sys/sx.h>
61#include <sys/sysctl.h>
62#include <sys/syslog.h>
63#include <sys/systm.h>
64
65#include <vm/uma.h>
66
67#include <net/if.h>
68#include <net/route.h>
69
70#include <netinet/in.h>
71#include <netinet/in_pcb.h>
72#include <netinet/in_systm.h>
73#include <netinet/in_var.h>
74#include <netinet/ip.h>
75#ifdef INET6
76#include <netinet/ip6.h>
77#endif
78#include <netinet/ip_icmp.h>
79#include <netinet/icmp_var.h>
80#include <netinet/ip_var.h>
81#include <netinet/ip_options.h>
82#ifdef INET6
83#include <netinet6/ip6_var.h>
84#endif
85#include <netinet/udp.h>
86#include <netinet/udp_var.h>
87
88#ifdef IPSEC
89#include <netipsec/ipsec.h>
90#include <netipsec/esp.h>
91#endif
92
93#include <machine/in_cksum.h>
94
95#include <security/mac/mac_framework.h>
96
97/*
98 * UDP protocol implementation.
99 * Per RFC 768, August, 1980.
100 */
101
102/*
103 * BSD 4.2 defaulted the udp checksum to be off. Turning off udp checksums
104 * removes the only data integrity mechanism for packets and malformed
105 * packets that would otherwise be discarded due to bad checksums, and may
106 * cause problems (especially for NFS data blocks).
107 */
108VNET_DEFINE(int, udp_cksum) = 1;
109SYSCTL_VNET_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
110 &VNET_NAME(udp_cksum), 0, "compute udp checksum");
111
112int udp_log_in_vain = 0;
113SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
114 &udp_log_in_vain, 0, "Log all incoming UDP packets");
115
116VNET_DEFINE(int, udp_blackhole) = 0;
117SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
118 &VNET_NAME(udp_blackhole), 0,
119 "Do not send port unreachables for refused connects");
120
121u_long udp_sendspace = 9216; /* really max datagram size */
122 /* 40 1K datagrams */
123SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
124 &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
125
126u_long udp_recvspace = 40 * (1024 +
127#ifdef INET6
128 sizeof(struct sockaddr_in6)
129#else
130 sizeof(struct sockaddr_in)
131#endif
132 );
133
134SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
135 &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
136
137VNET_DEFINE(struct inpcbhead, udb); /* from udp_var.h */
138VNET_DEFINE(struct inpcbinfo, udbinfo);
139static VNET_DEFINE(uma_zone_t, udpcb_zone);
140#define V_udpcb_zone VNET(udpcb_zone)
141
142#ifndef UDBHASHSIZE
143#define UDBHASHSIZE 128
144#endif
145
146VNET_DEFINE(struct udpstat, udpstat); /* from udp_var.h */
147SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
148 &VNET_NAME(udpstat), udpstat,
149 "UDP statistics (struct udpstat, netinet/udp_var.h)");
150
151#ifdef INET
152static void udp_detach(struct socket *so);
153static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
154 struct mbuf *, struct thread *);
155#endif
156
157#ifdef IPSEC
158#ifdef IPSEC_NAT_T
159#define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
160#ifdef INET
161static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
162#endif
163#endif /* IPSEC_NAT_T */
164#endif /* IPSEC */
165
166static void
167udp_zone_change(void *tag)
168{
169
170 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
171 uma_zone_set_max(V_udpcb_zone, maxsockets);
172}
173
174static int
175udp_inpcb_init(void *mem, int size, int flags)
176{
177 struct inpcb *inp;
178
179 inp = mem;
180 INP_LOCK_INIT(inp, "inp", "udpinp");
181 return (0);
182}
183
184void
185udp_init(void)
186{
187
188 in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
189 "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE,
190 IPI_HASHFIELDS_2TUPLE);
191 V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
192 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
193 uma_zone_set_max(V_udpcb_zone, maxsockets);
194 uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
195 EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
196 EVENTHANDLER_PRI_ANY);
197}
198
199/*
200 * Kernel module interface for updating udpstat. The argument is an index
201 * into udpstat treated as an array of u_long. While this encodes the
202 * general layout of udpstat into the caller, it doesn't encode its location,
203 * so that future changes to add, for example, per-CPU stats support won't
204 * cause binary compatibility problems for kernel modules.
205 */
206void
207kmod_udpstat_inc(int statnum)
208{
209
210 (*((u_long *)&V_udpstat + statnum))++;
211}
212
213int
214udp_newudpcb(struct inpcb *inp)
215{
216 struct udpcb *up;
217
218 up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
219 if (up == NULL)
220 return (ENOBUFS);
221 inp->inp_ppcb = up;
222 return (0);
223}
224
225void
226udp_discardcb(struct udpcb *up)
227{
228
229 uma_zfree(V_udpcb_zone, up);
230}
231
232#ifdef VIMAGE
233void
234udp_destroy(void)
235{
236
237 in_pcbinfo_destroy(&V_udbinfo);
238 uma_zdestroy(V_udpcb_zone);
239}
240#endif
241
242#ifdef INET
243/*
244 * Subroutine of udp_input(), which appends the provided mbuf chain to the
245 * passed pcb/socket. The caller must provide a sockaddr_in via udp_in that
246 * contains the source address. If the socket ends up being an IPv6 socket,
247 * udp_append() will convert to a sockaddr_in6 before passing the address
248 * into the socket code.
249 */
250static void
251udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
252 struct sockaddr_in *udp_in)
253{
254 struct sockaddr *append_sa;
255 struct socket *so;
256 struct mbuf *opts = 0;
257#ifdef INET6
258 struct sockaddr_in6 udp_in6;
259#endif
260 struct udpcb *up;
261
262 INP_LOCK_ASSERT(inp);
263
264 /*
265 * Engage the tunneling protocol.
266 */
267 up = intoudpcb(inp);
268 if (up->u_tun_func != NULL) {
269 (*up->u_tun_func)(n, off, inp);
270 return;
271 }
272
273 if (n == NULL)
274 return;
275
276 off += sizeof(struct udphdr);
277
278#ifdef IPSEC
279 /* Check AH/ESP integrity. */
280 if (ipsec4_in_reject(n, inp)) {
281 m_freem(n);
282 IPSECSTAT_INC(in_polvio);
283 return;
284 }
285#ifdef IPSEC_NAT_T
286 up = intoudpcb(inp);
287 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
288 if (up->u_flags & UF_ESPINUDP_ALL) { /* IPSec UDP encaps. */
289 n = udp4_espdecap(inp, n, off);
290 if (n == NULL) /* Consumed. */
291 return;
292 }
293#endif /* IPSEC_NAT_T */
294#endif /* IPSEC */
295#ifdef MAC
296 if (mac_inpcb_check_deliver(inp, n) != 0) {
297 m_freem(n);
298 return;
299 }
300#endif /* MAC */
301 if (inp->inp_flags & INP_CONTROLOPTS ||
302 inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
303#ifdef INET6
304 if (inp->inp_vflag & INP_IPV6)
305 (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
306 else
307#endif /* INET6 */
308 ip_savecontrol(inp, &opts, ip, n);
309 }
310#ifdef INET6
311 if (inp->inp_vflag & INP_IPV6) {
312 bzero(&udp_in6, sizeof(udp_in6));
313 udp_in6.sin6_len = sizeof(udp_in6);
314 udp_in6.sin6_family = AF_INET6;
315 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
316 append_sa = (struct sockaddr *)&udp_in6;
317 } else
318#endif /* INET6 */
319 append_sa = (struct sockaddr *)udp_in;
320 m_adj(n, off);
321
322 so = inp->inp_socket;
323 SOCKBUF_LOCK(&so->so_rcv);
324 if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
325 SOCKBUF_UNLOCK(&so->so_rcv);
326 m_freem(n);
327 if (opts)
328 m_freem(opts);
329 UDPSTAT_INC(udps_fullsock);
330 } else
331 sorwakeup_locked(so);
332}
333
334void
335udp_input(struct mbuf *m, int off)
336{
337 int iphlen = off;
338 struct ip *ip;
339 struct udphdr *uh;
340 struct ifnet *ifp;
341 struct inpcb *inp;
342 uint16_t len, ip_len;
343 struct ip save_ip;
344 struct sockaddr_in udp_in;
345 struct m_tag *fwd_tag;
346
347 ifp = m->m_pkthdr.rcvif;
348 UDPSTAT_INC(udps_ipackets);
349
350 /*
351 * Strip IP options, if any; should skip this, make available to
352 * user, and use on returned packets, but we don't yet have a way to
353 * check the checksum with options still present.
354 */
355 if (iphlen > sizeof (struct ip)) {
356 ip_stripoptions(m);
357 iphlen = sizeof(struct ip);
358 }
359
360 /*
361 * Get IP and UDP header together in first mbuf.
362 */
363 ip = mtod(m, struct ip *);
364 if (m->m_len < iphlen + sizeof(struct udphdr)) {
365 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
366 UDPSTAT_INC(udps_hdrops);
367 return;
368 }
369 ip = mtod(m, struct ip *);
370 }
371 uh = (struct udphdr *)((caddr_t)ip + iphlen);
372
373 /*
374 * Destination port of 0 is illegal, based on RFC768.
375 */
376 if (uh->uh_dport == 0)
377 goto badunlocked;
378
379 /*
380 * Construct sockaddr format source address. Stuff source address
381 * and datagram in user buffer.
382 */
383 bzero(&udp_in, sizeof(udp_in));
384 udp_in.sin_len = sizeof(udp_in);
385 udp_in.sin_family = AF_INET;
386 udp_in.sin_port = uh->uh_sport;
387 udp_in.sin_addr = ip->ip_src;
388
389 /*
390 * Make mbuf data length reflect UDP length. If not enough data to
391 * reflect UDP length, drop.
392 */
393 len = ntohs((u_short)uh->uh_ulen);
394 ip_len = ntohs(ip->ip_len) - iphlen;
395 if (ip_len != len) {
396 if (len > ip_len || len < sizeof(struct udphdr)) {
397 UDPSTAT_INC(udps_badlen);
398 goto badunlocked;
399 }
400 m_adj(m, len - ip_len);
401 }
402
403 /*
404 * Save a copy of the IP header in case we want restore it for
405 * sending an ICMP error message in response.
406 */
407 if (!V_udp_blackhole)
408 save_ip = *ip;
409 else
410 memset(&save_ip, 0, sizeof(save_ip));
411
412 /*
413 * Checksum extended UDP header and data.
414 */
415 if (uh->uh_sum) {
416 u_short uh_sum;
417
418 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
419 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
420 uh_sum = m->m_pkthdr.csum_data;
421 else
422 uh_sum = in_pseudo(ip->ip_src.s_addr,
423 ip->ip_dst.s_addr, htonl((u_short)len +
424 m->m_pkthdr.csum_data + IPPROTO_UDP));
425 uh_sum ^= 0xffff;
426 } else {
427 char b[9];
428
429 bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
430 bzero(((struct ipovly *)ip)->ih_x1, 9);
431 ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
432 uh_sum = in_cksum(m, len + sizeof (struct ip));
433 bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
434 }
435 if (uh_sum) {
436 UDPSTAT_INC(udps_badsum);
437 m_freem(m);
438 return;
439 }
440 } else
441 UDPSTAT_INC(udps_nosum);
442
443 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
444 in_broadcast(ip->ip_dst, ifp)) {
445 struct inpcb *last;
446 struct ip_moptions *imo;
447
448 INP_INFO_RLOCK(&V_udbinfo);
449 last = NULL;
450 LIST_FOREACH(inp, &V_udb, inp_list) {
451 if (inp->inp_lport != uh->uh_dport)
452 continue;
453#ifdef INET6
454 if ((inp->inp_vflag & INP_IPV4) == 0)
455 continue;
456#endif
457 if (inp->inp_laddr.s_addr != INADDR_ANY &&
458 inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
459 continue;
460 if (inp->inp_faddr.s_addr != INADDR_ANY &&
461 inp->inp_faddr.s_addr != ip->ip_src.s_addr)
462 continue;
463 if (inp->inp_fport != 0 &&
464 inp->inp_fport != uh->uh_sport)
465 continue;
466
467 INP_RLOCK(inp);
468
469 /*
470 * XXXRW: Because we weren't holding either the inpcb
471 * or the hash lock when we checked for a match
472 * before, we should probably recheck now that the
473 * inpcb lock is held.
474 */
475
476 /*
477 * Handle socket delivery policy for any-source
478 * and source-specific multicast. [RFC3678]
479 */
480 imo = inp->inp_moptions;
481 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
482 struct sockaddr_in group;
483 int blocked;
484 if (imo == NULL) {
485 INP_RUNLOCK(inp);
486 continue;
487 }
488 bzero(&group, sizeof(struct sockaddr_in));
489 group.sin_len = sizeof(struct sockaddr_in);
490 group.sin_family = AF_INET;
491 group.sin_addr = ip->ip_dst;
492
493 blocked = imo_multi_filter(imo, ifp,
494 (struct sockaddr *)&group,
495 (struct sockaddr *)&udp_in);
496 if (blocked != MCAST_PASS) {
497 if (blocked == MCAST_NOTGMEMBER)
498 IPSTAT_INC(ips_notmember);
499 if (blocked == MCAST_NOTSMEMBER ||
500 blocked == MCAST_MUTED)
501 UDPSTAT_INC(udps_filtermcast);
502 INP_RUNLOCK(inp);
503 continue;
504 }
505 }
506 if (last != NULL) {
507 struct mbuf *n;
508
509 n = m_copy(m, 0, M_COPYALL);
510 udp_append(last, ip, n, iphlen, &udp_in);
511 INP_RUNLOCK(last);
512 }
513 last = inp;
514 /*
515 * Don't look for additional matches if this one does
516 * not have either the SO_REUSEPORT or SO_REUSEADDR
517 * socket options set. This heuristic avoids
518 * searching through all pcbs in the common case of a
519 * non-shared port. It assumes that an application
520 * will never clear these options after setting them.
521 */
522 if ((last->inp_socket->so_options &
523 (SO_REUSEPORT|SO_REUSEADDR)) == 0)
524 break;
525 }
526
527 if (last == NULL) {
528 /*
529 * No matching pcb found; discard datagram. (No need
530 * to send an ICMP Port Unreachable for a broadcast
531 * or multicast datgram.)
532 */
533 UDPSTAT_INC(udps_noportbcast);
534 if (inp)
535 INP_RUNLOCK(inp);
536 INP_INFO_RUNLOCK(&V_udbinfo);
537 goto badunlocked;
538 }
539 udp_append(last, ip, m, iphlen, &udp_in);
540 INP_RUNLOCK(last);
541 INP_INFO_RUNLOCK(&V_udbinfo);
542 return;
543 }
544
545 /*
546 * Locate pcb for datagram.
547 */
548
549 /*
550 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
551 */
552 if ((m->m_flags & M_IP_NEXTHOP) &&
553 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
554 struct sockaddr_in *next_hop;
555
556 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
557
558 /*
559 * Transparently forwarded. Pretend to be the destination.
560 * Already got one like this?
561 */
562 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
563 ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
564 if (!inp) {
565 /*
566 * It's new. Try to find the ambushing socket.
567 * Because we've rewritten the destination address,
568 * any hardware-generated hash is ignored.
569 */
570 inp = in_pcblookup(&V_udbinfo, ip->ip_src,
571 uh->uh_sport, next_hop->sin_addr,
572 next_hop->sin_port ? htons(next_hop->sin_port) :
573 uh->uh_dport, INPLOOKUP_WILDCARD |
574 INPLOOKUP_RLOCKPCB, ifp);
575 }
576 /* Remove the tag from the packet. We don't need it anymore. */
577 m_tag_delete(m, fwd_tag);
578 m->m_flags &= ~M_IP_NEXTHOP;
579 } else
580 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
581 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
582 INPLOOKUP_RLOCKPCB, ifp, m);
583 if (inp == NULL) {
584 if (udp_log_in_vain) {
585 char buf[4*sizeof "123"];
586
587 strcpy(buf, inet_ntoa(ip->ip_dst));
588 log(LOG_INFO,
589 "Connection attempt to UDP %s:%d from %s:%d\n",
590 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
591 ntohs(uh->uh_sport));
592 }
593 UDPSTAT_INC(udps_noport);
594 if (m->m_flags & (M_BCAST | M_MCAST)) {
595 UDPSTAT_INC(udps_noportbcast);
596 goto badunlocked;
597 }
598 if (V_udp_blackhole)
599 goto badunlocked;
600 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
601 goto badunlocked;
602 *ip = save_ip;
603 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
604 return;
605 }
606
607 /*
608 * Check the minimum TTL for socket.
609 */
610 INP_RLOCK_ASSERT(inp);
611 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
612 INP_RUNLOCK(inp);
613 m_freem(m);
614 return;
615 }
616 udp_append(inp, ip, m, iphlen, &udp_in);
617 INP_RUNLOCK(inp);
618 return;
619
620badunlocked:
621 m_freem(m);
622}
623#endif /* INET */
624
625/*
626 * Notify a udp user of an asynchronous error; just wake up so that they can
627 * collect error status.
628 */
629struct inpcb *
630udp_notify(struct inpcb *inp, int errno)
631{
632
633 /*
634 * While udp_ctlinput() always calls udp_notify() with a read lock
635 * when invoking it directly, in_pcbnotifyall() currently uses write
636 * locks due to sharing code with TCP. For now, accept either a read
637 * or a write lock, but a read lock is sufficient.
638 */
639 INP_LOCK_ASSERT(inp);
640
641 inp->inp_socket->so_error = errno;
642 sorwakeup(inp->inp_socket);
643 sowwakeup(inp->inp_socket);
644 return (inp);
645}
646
647#ifdef INET
648void
649udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
650{
651 struct ip *ip = vip;
652 struct udphdr *uh;
653 struct in_addr faddr;
654 struct inpcb *inp;
655
656 faddr = ((struct sockaddr_in *)sa)->sin_addr;
657 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
658 return;
659
660 /*
661 * Redirects don't need to be handled up here.
662 */
663 if (PRC_IS_REDIRECT(cmd))
664 return;
665
666 /*
667 * Hostdead is ugly because it goes linearly through all PCBs.
668 *
669 * XXX: We never get this from ICMP, otherwise it makes an excellent
670 * DoS attack on machines with many connections.
671 */
672 if (cmd == PRC_HOSTDEAD)
673 ip = NULL;
674 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
675 return;
676 if (ip != NULL) {
677 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
678 inp = in_pcblookup(&V_udbinfo, faddr, uh->uh_dport,
679 ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
680 if (inp != NULL) {
681 INP_RLOCK_ASSERT(inp);
682 if (inp->inp_socket != NULL) {
683 udp_notify(inp, inetctlerrmap[cmd]);
684 }
685 INP_RUNLOCK(inp);
686 }
687 } else
688 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
689 udp_notify);
690}
691#endif /* INET */
692
693static int
694udp_pcblist(SYSCTL_HANDLER_ARGS)
695{
696 int error, i, n;
697 struct inpcb *inp, **inp_list;
698 inp_gen_t gencnt;
699 struct xinpgen xig;
700
701 /*
702 * The process of preparing the PCB list is too time-consuming and
703 * resource-intensive to repeat twice on every request.
704 */
705 if (req->oldptr == 0) {
706 n = V_udbinfo.ipi_count;
707 n += imax(n / 8, 10);
708 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
709 return (0);
710 }
711
712 if (req->newptr != 0)
713 return (EPERM);
714
715 /*
716 * OK, now we're committed to doing something.
717 */
718 INP_INFO_RLOCK(&V_udbinfo);
719 gencnt = V_udbinfo.ipi_gencnt;
720 n = V_udbinfo.ipi_count;
721 INP_INFO_RUNLOCK(&V_udbinfo);
722
723 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
724 + n * sizeof(struct xinpcb));
725 if (error != 0)
726 return (error);
727
728 xig.xig_len = sizeof xig;
729 xig.xig_count = n;
730 xig.xig_gen = gencnt;
731 xig.xig_sogen = so_gencnt;
732 error = SYSCTL_OUT(req, &xig, sizeof xig);
733 if (error)
734 return (error);
735
736 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
737 if (inp_list == 0)
738 return (ENOMEM);
739
740 INP_INFO_RLOCK(&V_udbinfo);
741 for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
742 inp = LIST_NEXT(inp, inp_list)) {
743 INP_WLOCK(inp);
744 if (inp->inp_gencnt <= gencnt &&
745 cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
746 in_pcbref(inp);
747 inp_list[i++] = inp;
748 }
749 INP_WUNLOCK(inp);
750 }
751 INP_INFO_RUNLOCK(&V_udbinfo);
752 n = i;
753
754 error = 0;
755 for (i = 0; i < n; i++) {
756 inp = inp_list[i];
757 INP_RLOCK(inp);
758 if (inp->inp_gencnt <= gencnt) {
759 struct xinpcb xi;
760
761 bzero(&xi, sizeof(xi));
762 xi.xi_len = sizeof xi;
763 /* XXX should avoid extra copy */
764 bcopy(inp, &xi.xi_inp, sizeof *inp);
765 if (inp->inp_socket)
766 sotoxsocket(inp->inp_socket, &xi.xi_socket);
767 xi.xi_inp.inp_gencnt = inp->inp_gencnt;
768 INP_RUNLOCK(inp);
769 error = SYSCTL_OUT(req, &xi, sizeof xi);
770 } else
771 INP_RUNLOCK(inp);
772 }
773 INP_INFO_WLOCK(&V_udbinfo);
774 for (i = 0; i < n; i++) {
775 inp = inp_list[i];
776 INP_RLOCK(inp);
777 if (!in_pcbrele_rlocked(inp))
778 INP_RUNLOCK(inp);
779 }
780 INP_INFO_WUNLOCK(&V_udbinfo);
781
782 if (!error) {
783 /*
784 * Give the user an updated idea of our state. If the
785 * generation differs from what we told her before, she knows
786 * that something happened while we were processing this
787 * request, and it might be necessary to retry.
788 */
789 INP_INFO_RLOCK(&V_udbinfo);
790 xig.xig_gen = V_udbinfo.ipi_gencnt;
791 xig.xig_sogen = so_gencnt;
792 xig.xig_count = V_udbinfo.ipi_count;
793 INP_INFO_RUNLOCK(&V_udbinfo);
794 error = SYSCTL_OUT(req, &xig, sizeof xig);
795 }
796 free(inp_list, M_TEMP);
797 return (error);
798}
799
800SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
801 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
802 udp_pcblist, "S,xinpcb", "List of active UDP sockets");
803
804#ifdef INET
805static int
806udp_getcred(SYSCTL_HANDLER_ARGS)
807{
808 struct xucred xuc;
809 struct sockaddr_in addrs[2];
810 struct inpcb *inp;
811 int error;
812
813 error = priv_check(req->td, PRIV_NETINET_GETCRED);
814 if (error)
815 return (error);
816 error = SYSCTL_IN(req, addrs, sizeof(addrs));
817 if (error)
818 return (error);
819 inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
820 addrs[0].sin_addr, addrs[0].sin_port,
821 INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
822 if (inp != NULL) {
823 INP_RLOCK_ASSERT(inp);
824 if (inp->inp_socket == NULL)
825 error = ENOENT;
826 if (error == 0)
827 error = cr_canseeinpcb(req->td->td_ucred, inp);
828 if (error == 0)
829 cru2x(inp->inp_cred, &xuc);
830 INP_RUNLOCK(inp);
831 } else
832 error = ENOENT;
833 if (error == 0)
834 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
835 return (error);
836}
837
838SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
839 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
840 udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
841#endif /* INET */
842
843int
844udp_ctloutput(struct socket *so, struct sockopt *sopt)
845{
846 int error = 0, optval;
847 struct inpcb *inp;
848#ifdef IPSEC_NAT_T
849 struct udpcb *up;
850#endif
851
852 inp = sotoinpcb(so);
853 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
854 INP_WLOCK(inp);
855 if (sopt->sopt_level != IPPROTO_UDP) {
856#ifdef INET6
857 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
858 INP_WUNLOCK(inp);
859 error = ip6_ctloutput(so, sopt);
860 }
861#endif
862#if defined(INET) && defined(INET6)
863 else
864#endif
865#ifdef INET
866 {
867 INP_WUNLOCK(inp);
868 error = ip_ctloutput(so, sopt);
869 }
870#endif
871 return (error);
872 }
873
874 switch (sopt->sopt_dir) {
875 case SOPT_SET:
876 switch (sopt->sopt_name) {
877 case UDP_ENCAP:
878 INP_WUNLOCK(inp);
879 error = sooptcopyin(sopt, &optval, sizeof optval,
880 sizeof optval);
881 if (error)
882 break;
883 inp = sotoinpcb(so);
884 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
885 INP_WLOCK(inp);
886#ifdef IPSEC_NAT_T
887 up = intoudpcb(inp);
888 KASSERT(up != NULL, ("%s: up == NULL", __func__));
889#endif
890 switch (optval) {
891 case 0:
892 /* Clear all UDP encap. */
893#ifdef IPSEC_NAT_T
894 up->u_flags &= ~UF_ESPINUDP_ALL;
895#endif
896 break;
897#ifdef IPSEC_NAT_T
898 case UDP_ENCAP_ESPINUDP:
899 case UDP_ENCAP_ESPINUDP_NON_IKE:
900 up->u_flags &= ~UF_ESPINUDP_ALL;
901 if (optval == UDP_ENCAP_ESPINUDP)
902 up->u_flags |= UF_ESPINUDP;
903 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
904 up->u_flags |= UF_ESPINUDP_NON_IKE;
905 break;
906#endif
907 default:
908 error = EINVAL;
909 break;
910 }
911 INP_WUNLOCK(inp);
912 break;
913 default:
914 INP_WUNLOCK(inp);
915 error = ENOPROTOOPT;
916 break;
917 }
918 break;
919 case SOPT_GET:
920 switch (sopt->sopt_name) {
921#ifdef IPSEC_NAT_T
922 case UDP_ENCAP:
923 up = intoudpcb(inp);
924 KASSERT(up != NULL, ("%s: up == NULL", __func__));
925 optval = up->u_flags & UF_ESPINUDP_ALL;
926 INP_WUNLOCK(inp);
927 error = sooptcopyout(sopt, &optval, sizeof optval);
928 break;
929#endif
930 default:
931 INP_WUNLOCK(inp);
932 error = ENOPROTOOPT;
933 break;
934 }
935 break;
936 }
937 return (error);
938}
939
940#ifdef INET
941#define UH_WLOCKED 2
942#define UH_RLOCKED 1
943#define UH_UNLOCKED 0
944static int
945udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
946 struct mbuf *control, struct thread *td)
947{
948 struct udpiphdr *ui;
949 int len = m->m_pkthdr.len;
950 struct in_addr faddr, laddr;
951 struct cmsghdr *cm;
952 struct sockaddr_in *sin, src;
953 int error = 0;
954 int ipflags;
955 u_short fport, lport;
956 int unlock_udbinfo;
957 u_char tos;
958
959 /*
960 * udp_output() may need to temporarily bind or connect the current
961 * inpcb. As such, we don't know up front whether we will need the
962 * pcbinfo lock or not. Do any work to decide what is needed up
963 * front before acquiring any locks.
964 */
965 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
966 if (control)
967 m_freem(control);
968 m_freem(m);
969 return (EMSGSIZE);
970 }
971
972 src.sin_family = 0;
973 INP_RLOCK(inp);
974 tos = inp->inp_ip_tos;
975 if (control != NULL) {
976 /*
977 * XXX: Currently, we assume all the optional information is
978 * stored in a single mbuf.
979 */
980 if (control->m_next) {
981 INP_RUNLOCK(inp);
982 m_freem(control);
983 m_freem(m);
984 return (EINVAL);
985 }
986 for (; control->m_len > 0;
987 control->m_data += CMSG_ALIGN(cm->cmsg_len),
988 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
989 cm = mtod(control, struct cmsghdr *);
990 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
991 || cm->cmsg_len > control->m_len) {
992 error = EINVAL;
993 break;
994 }
995 if (cm->cmsg_level != IPPROTO_IP)
996 continue;
997
998 switch (cm->cmsg_type) {
999 case IP_SENDSRCADDR:
1000 if (cm->cmsg_len !=
1001 CMSG_LEN(sizeof(struct in_addr))) {
1002 error = EINVAL;
1003 break;
1004 }
1005 bzero(&src, sizeof(src));
1006 src.sin_family = AF_INET;
1007 src.sin_len = sizeof(src);
1008 src.sin_port = inp->inp_lport;
1009 src.sin_addr =
1010 *(struct in_addr *)CMSG_DATA(cm);
1011 break;
1012
1013 case IP_TOS:
1014 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1015 error = EINVAL;
1016 break;
1017 }
1018 tos = *(u_char *)CMSG_DATA(cm);
1019 break;
1020
1021 default:
1022 error = ENOPROTOOPT;
1023 break;
1024 }
1025 if (error)
1026 break;
1027 }
1028 m_freem(control);
1029 }
1030 if (error) {
1031 INP_RUNLOCK(inp);
1032 m_freem(m);
1033 return (error);
1034 }
1035
1036 /*
1037 * Depending on whether or not the application has bound or connected
1038 * the socket, we may have to do varying levels of work. The optimal
1039 * case is for a connected UDP socket, as a global lock isn't
1040 * required at all.
1041 *
1042 * In order to decide which we need, we require stability of the
1043 * inpcb binding, which we ensure by acquiring a read lock on the
1044 * inpcb. This doesn't strictly follow the lock order, so we play
1045 * the trylock and retry game; note that we may end up with more
1046 * conservative locks than required the second time around, so later
1047 * assertions have to accept that. Further analysis of the number of
1048 * misses under contention is required.
1049 *
1050 * XXXRW: Check that hash locking update here is correct.
1051 */
1052 sin = (struct sockaddr_in *)addr;
1053 if (sin != NULL &&
1054 (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1055 INP_RUNLOCK(inp);
1056 INP_WLOCK(inp);
1057 INP_HASH_WLOCK(&V_udbinfo);
1058 unlock_udbinfo = UH_WLOCKED;
1059 } else if ((sin != NULL && (
1060 (sin->sin_addr.s_addr == INADDR_ANY) ||
1061 (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1062 (inp->inp_laddr.s_addr == INADDR_ANY) ||
1063 (inp->inp_lport == 0))) ||
1064 (src.sin_family == AF_INET)) {
1065 INP_HASH_RLOCK(&V_udbinfo);
1066 unlock_udbinfo = UH_RLOCKED;
1067 } else
1068 unlock_udbinfo = UH_UNLOCKED;
1069
1070 /*
1071 * If the IP_SENDSRCADDR control message was specified, override the
1072 * source address for this datagram. Its use is invalidated if the
1073 * address thus specified is incomplete or clobbers other inpcbs.
1074 */
1075 laddr = inp->inp_laddr;
1076 lport = inp->inp_lport;
1077 if (src.sin_family == AF_INET) {
1078 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1079 if ((lport == 0) ||
1080 (laddr.s_addr == INADDR_ANY &&
1081 src.sin_addr.s_addr == INADDR_ANY)) {
1082 error = EINVAL;
1083 goto release;
1084 }
1085 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1086 &laddr.s_addr, &lport, td->td_ucred);
1087 if (error)
1088 goto release;
1089 }
1090
1091 /*
1092 * If a UDP socket has been connected, then a local address/port will
1093 * have been selected and bound.
1094 *
1095 * If a UDP socket has not been connected to, then an explicit
1096 * destination address must be used, in which case a local
1097 * address/port may not have been selected and bound.
1098 */
1099 if (sin != NULL) {
1100 INP_LOCK_ASSERT(inp);
1101 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1102 error = EISCONN;
1103 goto release;
1104 }
1105
1106 /*
1107 * Jail may rewrite the destination address, so let it do
1108 * that before we use it.
1109 */
1110 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1111 if (error)
1112 goto release;
1113
1114 /*
1115 * If a local address or port hasn't yet been selected, or if
1116 * the destination address needs to be rewritten due to using
1117 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1118 * to do the heavy lifting. Once a port is selected, we
1119 * commit the binding back to the socket; we also commit the
1120 * binding of the address if in jail.
1121 *
1122 * If we already have a valid binding and we're not
1123 * requesting a destination address rewrite, use a fast path.
1124 */
1125 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1126 inp->inp_lport == 0 ||
1127 sin->sin_addr.s_addr == INADDR_ANY ||
1128 sin->sin_addr.s_addr == INADDR_BROADCAST) {
1129 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1130 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1131 &lport, &faddr.s_addr, &fport, NULL,
1132 td->td_ucred);
1133 if (error)
1134 goto release;
1135
1136 /*
1137 * XXXRW: Why not commit the port if the address is
1138 * !INADDR_ANY?
1139 */
1140 /* Commit the local port if newly assigned. */
1141 if (inp->inp_laddr.s_addr == INADDR_ANY &&
1142 inp->inp_lport == 0) {
1143 INP_WLOCK_ASSERT(inp);
1144 INP_HASH_WLOCK_ASSERT(&V_udbinfo);
1145 /*
1146 * Remember addr if jailed, to prevent
1147 * rebinding.
1148 */
1149 if (prison_flag(td->td_ucred, PR_IP4))
1150 inp->inp_laddr = laddr;
1151 inp->inp_lport = lport;
1152 if (in_pcbinshash(inp) != 0) {
1153 inp->inp_lport = 0;
1154 error = EAGAIN;
1155 goto release;
1156 }
1157 inp->inp_flags |= INP_ANONPORT;
1158 }
1159 } else {
1160 faddr = sin->sin_addr;
1161 fport = sin->sin_port;
1162 }
1163 } else {
1164 INP_LOCK_ASSERT(inp);
1165 faddr = inp->inp_faddr;
1166 fport = inp->inp_fport;
1167 if (faddr.s_addr == INADDR_ANY) {
1168 error = ENOTCONN;
1169 goto release;
1170 }
1171 }
1172
1173 /*
1174 * Calculate data length and get a mbuf for UDP, IP, and possible
1175 * link-layer headers. Immediate slide the data pointer back forward
1176 * since we won't use that space at this layer.
1177 */
1178 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1179 if (m == NULL) {
1180 error = ENOBUFS;
1181 goto release;
1182 }
1183 m->m_data += max_linkhdr;
1184 m->m_len -= max_linkhdr;
1185 m->m_pkthdr.len -= max_linkhdr;
1186
1187 /*
1188 * Fill in mbuf with extended UDP header and addresses and length put
1189 * into network format.
1190 */
1191 ui = mtod(m, struct udpiphdr *);
1192 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */
1193 ui->ui_pr = IPPROTO_UDP;
1194 ui->ui_src = laddr;
1195 ui->ui_dst = faddr;
1196 ui->ui_sport = lport;
1197 ui->ui_dport = fport;
1198 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1199
1200 /*
1201 * Set the Don't Fragment bit in the IP header.
1202 */
1203 if (inp->inp_flags & INP_DONTFRAG) {
1204 struct ip *ip;
1205
1206 ip = (struct ip *)&ui->ui_i;
1207 ip->ip_off |= htons(IP_DF);
1208 }
1209
1210 ipflags = 0;
1211 if (inp->inp_socket->so_options & SO_DONTROUTE)
1212 ipflags |= IP_ROUTETOIF;
1213 if (inp->inp_socket->so_options & SO_BROADCAST)
1214 ipflags |= IP_ALLOWBROADCAST;
1215 if (inp->inp_flags & INP_ONESBCAST)
1216 ipflags |= IP_SENDONES;
1217
1218#ifdef MAC
1219 mac_inpcb_create_mbuf(inp, m);
1220#endif
1221
1222 /*
1223 * Set up checksum and output datagram.
1224 */
1225 if (V_udp_cksum) {
1226 if (inp->inp_flags & INP_ONESBCAST)
1227 faddr.s_addr = INADDR_BROADCAST;
1228 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1229 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1230 m->m_pkthdr.csum_flags = CSUM_UDP;
1231 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1232 } else
1233 ui->ui_sum = 0;
1234 ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1235 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
1236 ((struct ip *)ui)->ip_tos = tos; /* XXX */
1237 UDPSTAT_INC(udps_opackets);
1238
1239 if (unlock_udbinfo == UH_WLOCKED)
1240 INP_HASH_WUNLOCK(&V_udbinfo);
1241 else if (unlock_udbinfo == UH_RLOCKED)
1242 INP_HASH_RUNLOCK(&V_udbinfo);
1243 error = ip_output(m, inp->inp_options, NULL, ipflags,
1244 inp->inp_moptions, inp);
1245 if (unlock_udbinfo == UH_WLOCKED)
1246 INP_WUNLOCK(inp);
1247 else
1248 INP_RUNLOCK(inp);
1249 return (error);
1250
1251release:
1252 if (unlock_udbinfo == UH_WLOCKED) {
1253 INP_HASH_WUNLOCK(&V_udbinfo);
1254 INP_WUNLOCK(inp);
1255 } else if (unlock_udbinfo == UH_RLOCKED) {
1256 INP_HASH_RUNLOCK(&V_udbinfo);
1257 INP_RUNLOCK(inp);
1258 } else
1259 INP_RUNLOCK(inp);
1260 m_freem(m);
1261 return (error);
1262}
1263
1264
1265#if defined(IPSEC) && defined(IPSEC_NAT_T)
1266/*
1267 * Potentially decap ESP in UDP frame. Check for an ESP header
1268 * and optional marker; if present, strip the UDP header and
1269 * push the result through IPSec.
1270 *
1271 * Returns mbuf to be processed (potentially re-allocated) or
1272 * NULL if consumed and/or processed.
1273 */
1274static struct mbuf *
1275udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1276{
1277 size_t minlen, payload, skip, iphlen;
1278 caddr_t data;
1279 struct udpcb *up;
1280 struct m_tag *tag;
1281 struct udphdr *udphdr;
1282 struct ip *ip;
1283
1284 INP_RLOCK_ASSERT(inp);
1285
1286 /*
1287 * Pull up data so the longest case is contiguous:
1288 * IP/UDP hdr + non ESP marker + ESP hdr.
1289 */
1290 minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1291 if (minlen > m->m_pkthdr.len)
1292 minlen = m->m_pkthdr.len;
1293 if ((m = m_pullup(m, minlen)) == NULL) {
1294 IPSECSTAT_INC(in_inval);
1295 return (NULL); /* Bypass caller processing. */
1296 }
1297 data = mtod(m, caddr_t); /* Points to ip header. */
1298 payload = m->m_len - off; /* Size of payload. */
1299
1300 if (payload == 1 && data[off] == '\xff')
1301 return (m); /* NB: keepalive packet, no decap. */
1302
1303 up = intoudpcb(inp);
1304 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1305 KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1306 ("u_flags 0x%x", up->u_flags));
1307
1308 /*
1309 * Check that the payload is large enough to hold an
1310 * ESP header and compute the amount of data to remove.
1311 *
1312 * NB: the caller has already done a pullup for us.
1313 * XXX can we assume alignment and eliminate bcopys?
1314 */
1315 if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1316 /*
1317 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1318 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1319 * possible AH mode non-IKE marker+non-ESP marker
1320 * from draft-ietf-ipsec-udp-encaps-00.txt.
1321 */
1322 uint64_t marker;
1323
1324 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1325 return (m); /* NB: no decap. */
1326 bcopy(data + off, &marker, sizeof(uint64_t));
1327 if (marker != 0) /* Non-IKE marker. */
1328 return (m); /* NB: no decap. */
1329 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1330 } else {
1331 uint32_t spi;
1332
1333 if (payload <= sizeof(struct esp)) {
1334 IPSECSTAT_INC(in_inval);
1335 m_freem(m);
1336 return (NULL); /* Discard. */
1337 }
1338 bcopy(data + off, &spi, sizeof(uint32_t));
1339 if (spi == 0) /* Non-ESP marker. */
1340 return (m); /* NB: no decap. */
1341 skip = sizeof(struct udphdr);
1342 }
1343
1344 /*
1345 * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1346 * the UDP ports. This is required if we want to select
1347 * the right SPD for multiple hosts behind same NAT.
1348 *
1349 * NB: ports are maintained in network byte order everywhere
1350 * in the NAT-T code.
1351 */
1352 tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1353 2 * sizeof(uint16_t), M_NOWAIT);
1354 if (tag == NULL) {
1355 IPSECSTAT_INC(in_nomem);
1356 m_freem(m);
1357 return (NULL); /* Discard. */
1358 }
1359 iphlen = off - sizeof(struct udphdr);
1360 udphdr = (struct udphdr *)(data + iphlen);
1361 ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1362 ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1363 m_tag_prepend(m, tag);
1364
1365 /*
1366 * Remove the UDP header (and possibly the non ESP marker)
1367 * IP header length is iphlen
1368 * Before:
1369 * <--- off --->
1370 * +----+------+-----+
1371 * | IP | UDP | ESP |
1372 * +----+------+-----+
1373 * <-skip->
1374 * After:
1375 * +----+-----+
1376 * | IP | ESP |
1377 * +----+-----+
1378 * <-skip->
1379 */
1380 ovbcopy(data, data + skip, iphlen);
1381 m_adj(m, skip);
1382
1383 ip = mtod(m, struct ip *);
1384 ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1385 ip->ip_p = IPPROTO_ESP;
1386
1387 /*
1388 * We cannot yet update the cksums so clear any
1389 * h/w cksum flags as they are no longer valid.
1390 */
1391 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1392 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1393
1394 (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1395 return (NULL); /* NB: consumed, bypass processing. */
1396}
1397#endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1398
1399static void
1400udp_abort(struct socket *so)
1401{
1402 struct inpcb *inp;
1403
1404 inp = sotoinpcb(so);
1405 KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1406 INP_WLOCK(inp);
1407 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1408 INP_HASH_WLOCK(&V_udbinfo);
1409 in_pcbdisconnect(inp);
1410 inp->inp_laddr.s_addr = INADDR_ANY;
1411 INP_HASH_WUNLOCK(&V_udbinfo);
1412 soisdisconnected(so);
1413 }
1414 INP_WUNLOCK(inp);
1415}
1416
1417static int
1418udp_attach(struct socket *so, int proto, struct thread *td)
1419{
1420 struct inpcb *inp;
1421 int error;
1422
1423 inp = sotoinpcb(so);
1424 KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1425 error = soreserve(so, udp_sendspace, udp_recvspace);
1426 if (error)
1427 return (error);
1428 INP_INFO_WLOCK(&V_udbinfo);
1429 error = in_pcballoc(so, &V_udbinfo);
1430 if (error) {
1431 INP_INFO_WUNLOCK(&V_udbinfo);
1432 return (error);
1433 }
1434
1435 inp = sotoinpcb(so);
1436 inp->inp_vflag |= INP_IPV4;
1437 inp->inp_ip_ttl = V_ip_defttl;
1438
1439 error = udp_newudpcb(inp);
1440 if (error) {
1441 in_pcbdetach(inp);
1442 in_pcbfree(inp);
1443 INP_INFO_WUNLOCK(&V_udbinfo);
1444 return (error);
1445 }
1446
1447 INP_WUNLOCK(inp);
1448 INP_INFO_WUNLOCK(&V_udbinfo);
1449 return (0);
1450}
1451#endif /* INET */
1452
1453int
1454udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1455{
1456 struct inpcb *inp;
1457 struct udpcb *up;
1458
1459 KASSERT(so->so_type == SOCK_DGRAM,
1460 ("udp_set_kernel_tunneling: !dgram"));
1461 inp = sotoinpcb(so);
1462 KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1463 INP_WLOCK(inp);
1464 up = intoudpcb(inp);
1465 if (up->u_tun_func != NULL) {
1466 INP_WUNLOCK(inp);
1467 return (EBUSY);
1468 }
1469 up->u_tun_func = f;
1470 INP_WUNLOCK(inp);
1471 return (0);
1472}
1473
1474#ifdef INET
1475static int
1476udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1477{
1478 struct inpcb *inp;
1479 int error;
1480
1481 inp = sotoinpcb(so);
1482 KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1483 INP_WLOCK(inp);
1484 INP_HASH_WLOCK(&V_udbinfo);
1485 error = in_pcbbind(inp, nam, td->td_ucred);
1486 INP_HASH_WUNLOCK(&V_udbinfo);
1487 INP_WUNLOCK(inp);
1488 return (error);
1489}
1490
1491static void
1492udp_close(struct socket *so)
1493{
1494 struct inpcb *inp;
1495
1496 inp = sotoinpcb(so);
1497 KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1498 INP_WLOCK(inp);
1499 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1500 INP_HASH_WLOCK(&V_udbinfo);
1501 in_pcbdisconnect(inp);
1502 inp->inp_laddr.s_addr = INADDR_ANY;
1503 INP_HASH_WUNLOCK(&V_udbinfo);
1504 soisdisconnected(so);
1505 }
1506 INP_WUNLOCK(inp);
1507}
1508
1509static int
1510udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1511{
1512 struct inpcb *inp;
1513 int error;
1514 struct sockaddr_in *sin;
1515
1516 inp = sotoinpcb(so);
1517 KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1518 INP_WLOCK(inp);
1519 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1520 INP_WUNLOCK(inp);
1521 return (EISCONN);
1522 }
1523 sin = (struct sockaddr_in *)nam;
1524 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1525 if (error != 0) {
1526 INP_WUNLOCK(inp);
1527 return (error);
1528 }
1529 INP_HASH_WLOCK(&V_udbinfo);
1530 error = in_pcbconnect(inp, nam, td->td_ucred);
1531 INP_HASH_WUNLOCK(&V_udbinfo);
1532 if (error == 0)
1533 soisconnected(so);
1534 INP_WUNLOCK(inp);
1535 return (error);
1536}
1537
1538static void
1539udp_detach(struct socket *so)
1540{
1541 struct inpcb *inp;
1542 struct udpcb *up;
1543
1544 inp = sotoinpcb(so);
1545 KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1546 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1547 ("udp_detach: not disconnected"));
1548 INP_INFO_WLOCK(&V_udbinfo);
1549 INP_WLOCK(inp);
1550 up = intoudpcb(inp);
1551 KASSERT(up != NULL, ("%s: up == NULL", __func__));
1552 inp->inp_ppcb = NULL;
1553 in_pcbdetach(inp);
1554 in_pcbfree(inp);
1555 INP_INFO_WUNLOCK(&V_udbinfo);
1556 udp_discardcb(up);
1557}
1558
1559static int
1560udp_disconnect(struct socket *so)
1561{
1562 struct inpcb *inp;
1563
1564 inp = sotoinpcb(so);
1565 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1566 INP_WLOCK(inp);
1567 if (inp->inp_faddr.s_addr == INADDR_ANY) {
1568 INP_WUNLOCK(inp);
1569 return (ENOTCONN);
1570 }
1571 INP_HASH_WLOCK(&V_udbinfo);
1572 in_pcbdisconnect(inp);
1573 inp->inp_laddr.s_addr = INADDR_ANY;
1574 INP_HASH_WUNLOCK(&V_udbinfo);
1575 SOCK_LOCK(so);
1576 so->so_state &= ~SS_ISCONNECTED; /* XXX */
1577 SOCK_UNLOCK(so);
1578 INP_WUNLOCK(inp);
1579 return (0);
1580}
1581
1582static int
1583udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1584 struct mbuf *control, struct thread *td)
1585{
1586 struct inpcb *inp;
1587
1588 inp = sotoinpcb(so);
1589 KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1590 return (udp_output(inp, m, addr, control, td));
1591}
1592#endif /* INET */
1593
1594int
1595udp_shutdown(struct socket *so)
1596{
1597 struct inpcb *inp;
1598
1599 inp = sotoinpcb(so);
1600 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1601 INP_WLOCK(inp);
1602 socantsendmore(so);
1603 INP_WUNLOCK(inp);
1604 return (0);
1605}
1606
1607#ifdef INET
1608struct pr_usrreqs udp_usrreqs = {
1609 .pru_abort = udp_abort,
1610 .pru_attach = udp_attach,
1611 .pru_bind = udp_bind,
1612 .pru_connect = udp_connect,
1613 .pru_control = in_control,
1614 .pru_detach = udp_detach,
1615 .pru_disconnect = udp_disconnect,
1616 .pru_peeraddr = in_getpeeraddr,
1617 .pru_send = udp_send,
1618 .pru_soreceive = soreceive_dgram,
1619 .pru_sosend = sosend_dgram,
1620 .pru_shutdown = udp_shutdown,
1621 .pru_sockaddr = in_getsockaddr,
1622 .pru_sosetlabel = in_pcbsosetlabel,
1623 .pru_close = udp_close,
1624};
1625#endif /* INET */