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: releng/8.1/sys/netinet/udp_usrreq.c 208767 2010-06-03 09:02:53Z rwatson $");
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
181 INP_INFO_LOCK_INIT(&V_udbinfo, "udp");
182 LIST_INIT(&V_udb);
183 #ifdef VIMAGE
184 V_udbinfo.ipi_vnet = curvnet;
185 #endif
186 V_udbinfo.ipi_listhead = &V_udb;
187 V_udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
188 &V_udbinfo.ipi_hashmask);
189 V_udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
190 &V_udbinfo.ipi_porthashmask);
191 V_udbinfo.ipi_zone = uma_zcreate("udp_inpcb", sizeof(struct inpcb),
192 NULL, NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
193 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
194
195 V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
196 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
197 uma_zone_set_max(V_udpcb_zone, maxsockets);
198
199 EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
200 EVENTHANDLER_PRI_ANY);
201 }
202
203 /*
204 * Kernel module interface for updating udpstat. The argument is an index
205 * into udpstat treated as an array of u_long. While this encodes the
206 * general layout of udpstat into the caller, it doesn't encode its location,
207 * so that future changes to add, for example, per-CPU stats support won't
208 * cause binary compatibility problems for kernel modules.
209 */
210 void
211 kmod_udpstat_inc(int statnum)
212 {
213
214 (*((u_long *)&V_udpstat + statnum))++;
215 }
216
217 int
218 udp_newudpcb(struct inpcb *inp)
219 {
220 struct udpcb *up;
221
222 up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
223 if (up == NULL)
224 return (ENOBUFS);
225 inp->inp_ppcb = up;
226 return (0);
227 }
228
229 void
230 udp_discardcb(struct udpcb *up)
231 {
232
233 uma_zfree(V_udpcb_zone, up);
234 }
235
236 #ifdef VIMAGE
237 void
238 udp_destroy(void)
239 {
240
241 hashdestroy(V_udbinfo.ipi_hashbase, M_PCB,
242 V_udbinfo.ipi_hashmask);
243 hashdestroy(V_udbinfo.ipi_porthashbase, M_PCB,
244 V_udbinfo.ipi_porthashmask);
245
246 uma_zdestroy(V_udpcb_zone);
247 uma_zdestroy(V_udbinfo.ipi_zone);
248 INP_INFO_LOCK_DESTROY(&V_udbinfo);
249 }
250 #endif
251
252 /*
253 * Subroutine of udp_input(), which appends the provided mbuf chain to the
254 * passed pcb/socket. The caller must provide a sockaddr_in via udp_in that
255 * contains the source address. If the socket ends up being an IPv6 socket,
256 * udp_append() will convert to a sockaddr_in6 before passing the address
257 * into the socket code.
258 */
259 static void
260 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
261 struct sockaddr_in *udp_in)
262 {
263 struct sockaddr *append_sa;
264 struct socket *so;
265 struct mbuf *opts = 0;
266 #ifdef INET6
267 struct sockaddr_in6 udp_in6;
268 #endif
269 #ifdef IPSEC
270 #ifdef IPSEC_NAT_T
271 #ifdef INET
272 struct udpcb *up;
273 #endif
274 #endif
275 #endif
276
277 INP_RLOCK_ASSERT(inp);
278
279 #ifdef IPSEC
280 /* Check AH/ESP integrity. */
281 if (ipsec4_in_reject(n, inp)) {
282 m_freem(n);
283 V_ipsec4stat.in_polvio++;
284 return;
285 }
286 #ifdef IPSEC_NAT_T
287 #ifdef INET
288 up = intoudpcb(inp);
289 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
290 if (up->u_flags & UF_ESPINUDP_ALL) { /* IPSec UDP encaps. */
291 n = udp4_espdecap(inp, n, off);
292 if (n == NULL) /* Consumed. */
293 return;
294 }
295 #endif /* INET */
296 #endif /* IPSEC_NAT_T */
297 #endif /* IPSEC */
298 #ifdef MAC
299 if (mac_inpcb_check_deliver(inp, n) != 0) {
300 m_freem(n);
301 return;
302 }
303 #endif
304 if (inp->inp_flags & INP_CONTROLOPTS ||
305 inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
306 #ifdef INET6
307 if (inp->inp_vflag & INP_IPV6)
308 (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
309 else
310 #endif
311 ip_savecontrol(inp, &opts, ip, n);
312 }
313 #ifdef INET6
314 if (inp->inp_vflag & INP_IPV6) {
315 bzero(&udp_in6, sizeof(udp_in6));
316 udp_in6.sin6_len = sizeof(udp_in6);
317 udp_in6.sin6_family = AF_INET6;
318 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
319 append_sa = (struct sockaddr *)&udp_in6;
320 } else
321 #endif
322 append_sa = (struct sockaddr *)udp_in;
323 m_adj(n, off);
324
325 so = inp->inp_socket;
326 SOCKBUF_LOCK(&so->so_rcv);
327 if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
328 SOCKBUF_UNLOCK(&so->so_rcv);
329 m_freem(n);
330 if (opts)
331 m_freem(opts);
332 UDPSTAT_INC(udps_fullsock);
333 } else
334 sorwakeup_locked(so);
335 }
336
337 void
338 udp_input(struct mbuf *m, int off)
339 {
340 int iphlen = off;
341 struct ip *ip;
342 struct udphdr *uh;
343 struct ifnet *ifp;
344 struct inpcb *inp;
345 struct udpcb *up;
346 int len;
347 struct ip save_ip;
348 struct sockaddr_in udp_in;
349 #ifdef IPFIREWALL_FORWARD
350 struct m_tag *fwd_tag;
351 #endif
352
353 ifp = m->m_pkthdr.rcvif;
354 UDPSTAT_INC(udps_ipackets);
355
356 /*
357 * Strip IP options, if any; should skip this, make available to
358 * user, and use on returned packets, but we don't yet have a way to
359 * check the checksum with options still present.
360 */
361 if (iphlen > sizeof (struct ip)) {
362 ip_stripoptions(m, (struct mbuf *)0);
363 iphlen = sizeof(struct ip);
364 }
365
366 /*
367 * Get IP and UDP header together in first mbuf.
368 */
369 ip = mtod(m, struct ip *);
370 if (m->m_len < iphlen + sizeof(struct udphdr)) {
371 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
372 UDPSTAT_INC(udps_hdrops);
373 return;
374 }
375 ip = mtod(m, struct ip *);
376 }
377 uh = (struct udphdr *)((caddr_t)ip + iphlen);
378
379 /*
380 * Destination port of 0 is illegal, based on RFC768.
381 */
382 if (uh->uh_dport == 0)
383 goto badunlocked;
384
385 /*
386 * Construct sockaddr format source address. Stuff source address
387 * and datagram in user buffer.
388 */
389 bzero(&udp_in, sizeof(udp_in));
390 udp_in.sin_len = sizeof(udp_in);
391 udp_in.sin_family = AF_INET;
392 udp_in.sin_port = uh->uh_sport;
393 udp_in.sin_addr = ip->ip_src;
394
395 /*
396 * Make mbuf data length reflect UDP length. If not enough data to
397 * reflect UDP length, drop.
398 */
399 len = ntohs((u_short)uh->uh_ulen);
400 if (ip->ip_len != len) {
401 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
402 UDPSTAT_INC(udps_badlen);
403 goto badunlocked;
404 }
405 m_adj(m, len - ip->ip_len);
406 /* ip->ip_len = len; */
407 }
408
409 /*
410 * Save a copy of the IP header in case we want restore it for
411 * sending an ICMP error message in response.
412 */
413 if (!V_udp_blackhole)
414 save_ip = *ip;
415 else
416 memset(&save_ip, 0, sizeof(save_ip));
417
418 /*
419 * Checksum extended UDP header and data.
420 */
421 if (uh->uh_sum) {
422 u_short uh_sum;
423
424 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
425 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
426 uh_sum = m->m_pkthdr.csum_data;
427 else
428 uh_sum = in_pseudo(ip->ip_src.s_addr,
429 ip->ip_dst.s_addr, htonl((u_short)len +
430 m->m_pkthdr.csum_data + IPPROTO_UDP));
431 uh_sum ^= 0xffff;
432 } else {
433 char b[9];
434
435 bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
436 bzero(((struct ipovly *)ip)->ih_x1, 9);
437 ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
438 uh_sum = in_cksum(m, len + sizeof (struct ip));
439 bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
440 }
441 if (uh_sum) {
442 UDPSTAT_INC(udps_badsum);
443 m_freem(m);
444 return;
445 }
446 } else
447 UDPSTAT_INC(udps_nosum);
448
449 #ifdef IPFIREWALL_FORWARD
450 /*
451 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
452 */
453 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
454 if (fwd_tag != NULL) {
455 struct sockaddr_in *next_hop;
456
457 /*
458 * Do the hack.
459 */
460 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
461 ip->ip_dst = next_hop->sin_addr;
462 uh->uh_dport = ntohs(next_hop->sin_port);
463
464 /*
465 * Remove the tag from the packet. We don't need it anymore.
466 */
467 m_tag_delete(m, fwd_tag);
468 }
469 #endif
470
471 INP_INFO_RLOCK(&V_udbinfo);
472 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
473 in_broadcast(ip->ip_dst, ifp)) {
474 struct inpcb *last;
475 struct ip_moptions *imo;
476
477 last = NULL;
478 LIST_FOREACH(inp, &V_udb, inp_list) {
479 if (inp->inp_lport != uh->uh_dport)
480 continue;
481 #ifdef INET6
482 if ((inp->inp_vflag & INP_IPV4) == 0)
483 continue;
484 #endif
485 if (inp->inp_laddr.s_addr != INADDR_ANY &&
486 inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
487 continue;
488 if (inp->inp_faddr.s_addr != INADDR_ANY &&
489 inp->inp_faddr.s_addr != ip->ip_src.s_addr)
490 continue;
491 if (inp->inp_fport != 0 &&
492 inp->inp_fport != uh->uh_sport)
493 continue;
494
495 INP_RLOCK(inp);
496
497 /*
498 * Handle socket delivery policy for any-source
499 * and source-specific multicast. [RFC3678]
500 */
501 imo = inp->inp_moptions;
502 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
503 imo != NULL) {
504 struct sockaddr_in group;
505 int blocked;
506
507 bzero(&group, sizeof(struct sockaddr_in));
508 group.sin_len = sizeof(struct sockaddr_in);
509 group.sin_family = AF_INET;
510 group.sin_addr = ip->ip_dst;
511
512 blocked = imo_multi_filter(imo, ifp,
513 (struct sockaddr *)&group,
514 (struct sockaddr *)&udp_in);
515 if (blocked != MCAST_PASS) {
516 if (blocked == MCAST_NOTGMEMBER)
517 IPSTAT_INC(ips_notmember);
518 if (blocked == MCAST_NOTSMEMBER ||
519 blocked == MCAST_MUTED)
520 UDPSTAT_INC(udps_filtermcast);
521 INP_RUNLOCK(inp);
522 continue;
523 }
524 }
525 if (last != NULL) {
526 struct mbuf *n;
527
528 n = m_copy(m, 0, M_COPYALL);
529 up = intoudpcb(last);
530 if (up->u_tun_func == NULL) {
531 if (n != NULL)
532 udp_append(last,
533 ip, n,
534 iphlen +
535 sizeof(struct udphdr),
536 &udp_in);
537 } else {
538 /*
539 * Engage the tunneling protocol we
540 * will have to leave the info_lock
541 * up, since we are hunting through
542 * multiple UDP's.
543 */
544
545 (*up->u_tun_func)(n, iphlen, last);
546 }
547 INP_RUNLOCK(last);
548 }
549 last = inp;
550 /*
551 * Don't look for additional matches if this one does
552 * not have either the SO_REUSEPORT or SO_REUSEADDR
553 * socket options set. This heuristic avoids
554 * searching through all pcbs in the common case of a
555 * non-shared port. It assumes that an application
556 * will never clear these options after setting them.
557 */
558 if ((last->inp_socket->so_options &
559 (SO_REUSEPORT|SO_REUSEADDR)) == 0)
560 break;
561 }
562
563 if (last == NULL) {
564 /*
565 * No matching pcb found; discard datagram. (No need
566 * to send an ICMP Port Unreachable for a broadcast
567 * or multicast datgram.)
568 */
569 UDPSTAT_INC(udps_noportbcast);
570 goto badheadlocked;
571 }
572 up = intoudpcb(last);
573 if (up->u_tun_func == NULL) {
574 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
575 &udp_in);
576 } else {
577 /*
578 * Engage the tunneling protocol.
579 */
580 (*up->u_tun_func)(m, iphlen, last);
581 }
582 INP_RUNLOCK(last);
583 INP_INFO_RUNLOCK(&V_udbinfo);
584 return;
585 }
586
587 /*
588 * Locate pcb for datagram.
589 */
590 inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
591 ip->ip_dst, uh->uh_dport, 1, ifp);
592 if (inp == NULL) {
593 if (udp_log_in_vain) {
594 char buf[4*sizeof "123"];
595
596 strcpy(buf, inet_ntoa(ip->ip_dst));
597 log(LOG_INFO,
598 "Connection attempt to UDP %s:%d from %s:%d\n",
599 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
600 ntohs(uh->uh_sport));
601 }
602 UDPSTAT_INC(udps_noport);
603 if (m->m_flags & (M_BCAST | M_MCAST)) {
604 UDPSTAT_INC(udps_noportbcast);
605 goto badheadlocked;
606 }
607 if (V_udp_blackhole)
608 goto badheadlocked;
609 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
610 goto badheadlocked;
611 *ip = save_ip;
612 ip->ip_len += iphlen;
613 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
614 INP_INFO_RUNLOCK(&V_udbinfo);
615 return;
616 }
617
618 /*
619 * Check the minimum TTL for socket.
620 */
621 INP_RLOCK(inp);
622 INP_INFO_RUNLOCK(&V_udbinfo);
623 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
624 INP_RUNLOCK(inp);
625 goto badunlocked;
626 }
627 up = intoudpcb(inp);
628 if (up->u_tun_func == NULL) {
629 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
630 } else {
631 /*
632 * Engage the tunneling protocol.
633 */
634
635 (*up->u_tun_func)(m, iphlen, inp);
636 }
637 INP_RUNLOCK(inp);
638 return;
639
640 badheadlocked:
641 if (inp)
642 INP_RUNLOCK(inp);
643 INP_INFO_RUNLOCK(&V_udbinfo);
644 badunlocked:
645 m_freem(m);
646 }
647
648 /*
649 * Notify a udp user of an asynchronous error; just wake up so that they can
650 * collect error status.
651 */
652 struct inpcb *
653 udp_notify(struct inpcb *inp, int errno)
654 {
655
656 /*
657 * While udp_ctlinput() always calls udp_notify() with a read lock
658 * when invoking it directly, in_pcbnotifyall() currently uses write
659 * locks due to sharing code with TCP. For now, accept either a read
660 * or a write lock, but a read lock is sufficient.
661 */
662 INP_LOCK_ASSERT(inp);
663
664 inp->inp_socket->so_error = errno;
665 sorwakeup(inp->inp_socket);
666 sowwakeup(inp->inp_socket);
667 return (inp);
668 }
669
670 void
671 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
672 {
673 struct ip *ip = vip;
674 struct udphdr *uh;
675 struct in_addr faddr;
676 struct inpcb *inp;
677
678 faddr = ((struct sockaddr_in *)sa)->sin_addr;
679 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
680 return;
681
682 /*
683 * Redirects don't need to be handled up here.
684 */
685 if (PRC_IS_REDIRECT(cmd))
686 return;
687
688 /*
689 * Hostdead is ugly because it goes linearly through all PCBs.
690 *
691 * XXX: We never get this from ICMP, otherwise it makes an excellent
692 * DoS attack on machines with many connections.
693 */
694 if (cmd == PRC_HOSTDEAD)
695 ip = NULL;
696 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
697 return;
698 if (ip != NULL) {
699 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
700 INP_INFO_RLOCK(&V_udbinfo);
701 inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
702 ip->ip_src, uh->uh_sport, 0, NULL);
703 if (inp != NULL) {
704 INP_RLOCK(inp);
705 if (inp->inp_socket != NULL) {
706 udp_notify(inp, inetctlerrmap[cmd]);
707 }
708 INP_RUNLOCK(inp);
709 }
710 INP_INFO_RUNLOCK(&V_udbinfo);
711 } else
712 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
713 udp_notify);
714 }
715
716 static int
717 udp_pcblist(SYSCTL_HANDLER_ARGS)
718 {
719 int error, i, n;
720 struct inpcb *inp, **inp_list;
721 inp_gen_t gencnt;
722 struct xinpgen xig;
723
724 /*
725 * The process of preparing the PCB list is too time-consuming and
726 * resource-intensive to repeat twice on every request.
727 */
728 if (req->oldptr == 0) {
729 n = V_udbinfo.ipi_count;
730 req->oldidx = 2 * (sizeof xig)
731 + (n + n/8) * sizeof(struct xinpcb);
732 return (0);
733 }
734
735 if (req->newptr != 0)
736 return (EPERM);
737
738 /*
739 * OK, now we're committed to doing something.
740 */
741 INP_INFO_RLOCK(&V_udbinfo);
742 gencnt = V_udbinfo.ipi_gencnt;
743 n = V_udbinfo.ipi_count;
744 INP_INFO_RUNLOCK(&V_udbinfo);
745
746 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
747 + n * sizeof(struct xinpcb));
748 if (error != 0)
749 return (error);
750
751 xig.xig_len = sizeof xig;
752 xig.xig_count = n;
753 xig.xig_gen = gencnt;
754 xig.xig_sogen = so_gencnt;
755 error = SYSCTL_OUT(req, &xig, sizeof xig);
756 if (error)
757 return (error);
758
759 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
760 if (inp_list == 0)
761 return (ENOMEM);
762
763 INP_INFO_RLOCK(&V_udbinfo);
764 for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
765 inp = LIST_NEXT(inp, inp_list)) {
766 INP_WLOCK(inp);
767 if (inp->inp_gencnt <= gencnt &&
768 cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
769 in_pcbref(inp);
770 inp_list[i++] = inp;
771 }
772 INP_WUNLOCK(inp);
773 }
774 INP_INFO_RUNLOCK(&V_udbinfo);
775 n = i;
776
777 error = 0;
778 for (i = 0; i < n; i++) {
779 inp = inp_list[i];
780 INP_RLOCK(inp);
781 if (inp->inp_gencnt <= gencnt) {
782 struct xinpcb xi;
783
784 bzero(&xi, sizeof(xi));
785 xi.xi_len = sizeof xi;
786 /* XXX should avoid extra copy */
787 bcopy(inp, &xi.xi_inp, sizeof *inp);
788 if (inp->inp_socket)
789 sotoxsocket(inp->inp_socket, &xi.xi_socket);
790 xi.xi_inp.inp_gencnt = inp->inp_gencnt;
791 INP_RUNLOCK(inp);
792 error = SYSCTL_OUT(req, &xi, sizeof xi);
793 } else
794 INP_RUNLOCK(inp);
795 }
796 INP_INFO_WLOCK(&V_udbinfo);
797 for (i = 0; i < n; i++) {
798 inp = inp_list[i];
799 INP_WLOCK(inp);
800 if (!in_pcbrele(inp))
801 INP_WUNLOCK(inp);
802 }
803 INP_INFO_WUNLOCK(&V_udbinfo);
804
805 if (!error) {
806 /*
807 * Give the user an updated idea of our state. If the
808 * generation differs from what we told her before, she knows
809 * that something happened while we were processing this
810 * request, and it might be necessary to retry.
811 */
812 INP_INFO_RLOCK(&V_udbinfo);
813 xig.xig_gen = V_udbinfo.ipi_gencnt;
814 xig.xig_sogen = so_gencnt;
815 xig.xig_count = V_udbinfo.ipi_count;
816 INP_INFO_RUNLOCK(&V_udbinfo);
817 error = SYSCTL_OUT(req, &xig, sizeof xig);
818 }
819 free(inp_list, M_TEMP);
820 return (error);
821 }
822
823 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
824 udp_pcblist, "S,xinpcb", "List of active UDP sockets");
825
826 static int
827 udp_getcred(SYSCTL_HANDLER_ARGS)
828 {
829 struct xucred xuc;
830 struct sockaddr_in addrs[2];
831 struct inpcb *inp;
832 int error;
833
834 error = priv_check(req->td, PRIV_NETINET_GETCRED);
835 if (error)
836 return (error);
837 error = SYSCTL_IN(req, addrs, sizeof(addrs));
838 if (error)
839 return (error);
840 INP_INFO_RLOCK(&V_udbinfo);
841 inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
842 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
843 if (inp != NULL) {
844 INP_RLOCK(inp);
845 INP_INFO_RUNLOCK(&V_udbinfo);
846 if (inp->inp_socket == NULL)
847 error = ENOENT;
848 if (error == 0)
849 error = cr_canseeinpcb(req->td->td_ucred, inp);
850 if (error == 0)
851 cru2x(inp->inp_cred, &xuc);
852 INP_RUNLOCK(inp);
853 } else {
854 INP_INFO_RUNLOCK(&V_udbinfo);
855 error = ENOENT;
856 }
857 if (error == 0)
858 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
859 return (error);
860 }
861
862 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
863 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
864 udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
865
866 int
867 udp_ctloutput(struct socket *so, struct sockopt *sopt)
868 {
869 int error = 0, optval;
870 struct inpcb *inp;
871 #ifdef IPSEC_NAT_T
872 struct udpcb *up;
873 #endif
874
875 inp = sotoinpcb(so);
876 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
877 INP_WLOCK(inp);
878 if (sopt->sopt_level != IPPROTO_UDP) {
879 #ifdef INET6
880 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
881 INP_WUNLOCK(inp);
882 error = ip6_ctloutput(so, sopt);
883 } else {
884 #endif
885 INP_WUNLOCK(inp);
886 error = ip_ctloutput(so, sopt);
887 #ifdef INET6
888 }
889 #endif
890 return (error);
891 }
892
893 switch (sopt->sopt_dir) {
894 case SOPT_SET:
895 switch (sopt->sopt_name) {
896 case UDP_ENCAP:
897 INP_WUNLOCK(inp);
898 error = sooptcopyin(sopt, &optval, sizeof optval,
899 sizeof optval);
900 if (error)
901 break;
902 inp = sotoinpcb(so);
903 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
904 INP_WLOCK(inp);
905 #ifdef IPSEC_NAT_T
906 up = intoudpcb(inp);
907 KASSERT(up != NULL, ("%s: up == NULL", __func__));
908 #endif
909 switch (optval) {
910 case 0:
911 /* Clear all UDP encap. */
912 #ifdef IPSEC_NAT_T
913 up->u_flags &= ~UF_ESPINUDP_ALL;
914 #endif
915 break;
916 #ifdef IPSEC_NAT_T
917 case UDP_ENCAP_ESPINUDP:
918 case UDP_ENCAP_ESPINUDP_NON_IKE:
919 up->u_flags &= ~UF_ESPINUDP_ALL;
920 if (optval == UDP_ENCAP_ESPINUDP)
921 up->u_flags |= UF_ESPINUDP;
922 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
923 up->u_flags |= UF_ESPINUDP_NON_IKE;
924 break;
925 #endif
926 default:
927 error = EINVAL;
928 break;
929 }
930 INP_WUNLOCK(inp);
931 break;
932 default:
933 INP_WUNLOCK(inp);
934 error = ENOPROTOOPT;
935 break;
936 }
937 break;
938 case SOPT_GET:
939 switch (sopt->sopt_name) {
940 #ifdef IPSEC_NAT_T
941 case UDP_ENCAP:
942 up = intoudpcb(inp);
943 KASSERT(up != NULL, ("%s: up == NULL", __func__));
944 optval = up->u_flags & UF_ESPINUDP_ALL;
945 INP_WUNLOCK(inp);
946 error = sooptcopyout(sopt, &optval, sizeof optval);
947 break;
948 #endif
949 default:
950 INP_WUNLOCK(inp);
951 error = ENOPROTOOPT;
952 break;
953 }
954 break;
955 }
956 return (error);
957 }
958
959 static int
960 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
961 struct mbuf *control, struct thread *td)
962 {
963 struct udpiphdr *ui;
964 int len = m->m_pkthdr.len;
965 struct in_addr faddr, laddr;
966 struct cmsghdr *cm;
967 struct sockaddr_in *sin, src;
968 int error = 0;
969 int ipflags;
970 u_short fport, lport;
971 int unlock_udbinfo;
972
973 /*
974 * udp_output() may need to temporarily bind or connect the current
975 * inpcb. As such, we don't know up front whether we will need the
976 * pcbinfo lock or not. Do any work to decide what is needed up
977 * front before acquiring any locks.
978 */
979 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
980 if (control)
981 m_freem(control);
982 m_freem(m);
983 return (EMSGSIZE);
984 }
985
986 src.sin_family = 0;
987 if (control != NULL) {
988 /*
989 * XXX: Currently, we assume all the optional information is
990 * stored in a single mbuf.
991 */
992 if (control->m_next) {
993 m_freem(control);
994 m_freem(m);
995 return (EINVAL);
996 }
997 for (; control->m_len > 0;
998 control->m_data += CMSG_ALIGN(cm->cmsg_len),
999 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1000 cm = mtod(control, struct cmsghdr *);
1001 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1002 || cm->cmsg_len > control->m_len) {
1003 error = EINVAL;
1004 break;
1005 }
1006 if (cm->cmsg_level != IPPROTO_IP)
1007 continue;
1008
1009 switch (cm->cmsg_type) {
1010 case IP_SENDSRCADDR:
1011 if (cm->cmsg_len !=
1012 CMSG_LEN(sizeof(struct in_addr))) {
1013 error = EINVAL;
1014 break;
1015 }
1016 bzero(&src, sizeof(src));
1017 src.sin_family = AF_INET;
1018 src.sin_len = sizeof(src);
1019 src.sin_port = inp->inp_lport;
1020 src.sin_addr =
1021 *(struct in_addr *)CMSG_DATA(cm);
1022 break;
1023
1024 default:
1025 error = ENOPROTOOPT;
1026 break;
1027 }
1028 if (error)
1029 break;
1030 }
1031 m_freem(control);
1032 }
1033 if (error) {
1034 m_freem(m);
1035 return (error);
1036 }
1037
1038 /*
1039 * Depending on whether or not the application has bound or connected
1040 * the socket, we may have to do varying levels of work. The optimal
1041 * case is for a connected UDP socket, as a global lock isn't
1042 * required at all.
1043 *
1044 * In order to decide which we need, we require stability of the
1045 * inpcb binding, which we ensure by acquiring a read lock on the
1046 * inpcb. This doesn't strictly follow the lock order, so we play
1047 * the trylock and retry game; note that we may end up with more
1048 * conservative locks than required the second time around, so later
1049 * assertions have to accept that. Further analysis of the number of
1050 * misses under contention is required.
1051 */
1052 sin = (struct sockaddr_in *)addr;
1053 INP_RLOCK(inp);
1054 if (sin != NULL &&
1055 (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1056 INP_RUNLOCK(inp);
1057 INP_INFO_WLOCK(&V_udbinfo);
1058 INP_WLOCK(inp);
1059 unlock_udbinfo = 2;
1060 } else if ((sin != NULL && (
1061 (sin->sin_addr.s_addr == INADDR_ANY) ||
1062 (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1063 (inp->inp_laddr.s_addr == INADDR_ANY) ||
1064 (inp->inp_lport == 0))) ||
1065 (src.sin_family == AF_INET)) {
1066 if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
1067 INP_RUNLOCK(inp);
1068 INP_INFO_RLOCK(&V_udbinfo);
1069 INP_RLOCK(inp);
1070 }
1071 unlock_udbinfo = 1;
1072 } else
1073 unlock_udbinfo = 0;
1074
1075 /*
1076 * If the IP_SENDSRCADDR control message was specified, override the
1077 * source address for this datagram. Its use is invalidated if the
1078 * address thus specified is incomplete or clobbers other inpcbs.
1079 */
1080 laddr = inp->inp_laddr;
1081 lport = inp->inp_lport;
1082 if (src.sin_family == AF_INET) {
1083 INP_INFO_LOCK_ASSERT(&V_udbinfo);
1084 if ((lport == 0) ||
1085 (laddr.s_addr == INADDR_ANY &&
1086 src.sin_addr.s_addr == INADDR_ANY)) {
1087 error = EINVAL;
1088 goto release;
1089 }
1090 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1091 &laddr.s_addr, &lport, td->td_ucred);
1092 if (error)
1093 goto release;
1094 }
1095
1096 /*
1097 * If a UDP socket has been connected, then a local address/port will
1098 * have been selected and bound.
1099 *
1100 * If a UDP socket has not been connected to, then an explicit
1101 * destination address must be used, in which case a local
1102 * address/port may not have been selected and bound.
1103 */
1104 if (sin != NULL) {
1105 INP_LOCK_ASSERT(inp);
1106 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1107 error = EISCONN;
1108 goto release;
1109 }
1110
1111 /*
1112 * Jail may rewrite the destination address, so let it do
1113 * that before we use it.
1114 */
1115 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1116 if (error)
1117 goto release;
1118
1119 /*
1120 * If a local address or port hasn't yet been selected, or if
1121 * the destination address needs to be rewritten due to using
1122 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1123 * to do the heavy lifting. Once a port is selected, we
1124 * commit the binding back to the socket; we also commit the
1125 * binding of the address if in jail.
1126 *
1127 * If we already have a valid binding and we're not
1128 * requesting a destination address rewrite, use a fast path.
1129 */
1130 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1131 inp->inp_lport == 0 ||
1132 sin->sin_addr.s_addr == INADDR_ANY ||
1133 sin->sin_addr.s_addr == INADDR_BROADCAST) {
1134 INP_INFO_LOCK_ASSERT(&V_udbinfo);
1135 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1136 &lport, &faddr.s_addr, &fport, NULL,
1137 td->td_ucred);
1138 if (error)
1139 goto release;
1140
1141 /*
1142 * XXXRW: Why not commit the port if the address is
1143 * !INADDR_ANY?
1144 */
1145 /* Commit the local port if newly assigned. */
1146 if (inp->inp_laddr.s_addr == INADDR_ANY &&
1147 inp->inp_lport == 0) {
1148 INP_INFO_WLOCK_ASSERT(&V_udbinfo);
1149 INP_WLOCK_ASSERT(inp);
1150 /*
1151 * Remember addr if jailed, to prevent
1152 * rebinding.
1153 */
1154 if (prison_flag(td->td_ucred, PR_IP4))
1155 inp->inp_laddr = laddr;
1156 inp->inp_lport = lport;
1157 if (in_pcbinshash(inp) != 0) {
1158 inp->inp_lport = 0;
1159 error = EAGAIN;
1160 goto release;
1161 }
1162 inp->inp_flags |= INP_ANONPORT;
1163 }
1164 } else {
1165 faddr = sin->sin_addr;
1166 fport = sin->sin_port;
1167 }
1168 } else {
1169 INP_LOCK_ASSERT(inp);
1170 faddr = inp->inp_faddr;
1171 fport = inp->inp_fport;
1172 if (faddr.s_addr == INADDR_ANY) {
1173 error = ENOTCONN;
1174 goto release;
1175 }
1176 }
1177
1178 /*
1179 * Calculate data length and get a mbuf for UDP, IP, and possible
1180 * link-layer headers. Immediate slide the data pointer back forward
1181 * since we won't use that space at this layer.
1182 */
1183 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1184 if (m == NULL) {
1185 error = ENOBUFS;
1186 goto release;
1187 }
1188 m->m_data += max_linkhdr;
1189 m->m_len -= max_linkhdr;
1190 m->m_pkthdr.len -= max_linkhdr;
1191
1192 /*
1193 * Fill in mbuf with extended UDP header and addresses and length put
1194 * into network format.
1195 */
1196 ui = mtod(m, struct udpiphdr *);
1197 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */
1198 ui->ui_pr = IPPROTO_UDP;
1199 ui->ui_src = laddr;
1200 ui->ui_dst = faddr;
1201 ui->ui_sport = lport;
1202 ui->ui_dport = fport;
1203 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1204
1205 /*
1206 * Set the Don't Fragment bit in the IP header.
1207 */
1208 if (inp->inp_flags & INP_DONTFRAG) {
1209 struct ip *ip;
1210
1211 ip = (struct ip *)&ui->ui_i;
1212 ip->ip_off |= IP_DF;
1213 }
1214
1215 ipflags = 0;
1216 if (inp->inp_socket->so_options & SO_DONTROUTE)
1217 ipflags |= IP_ROUTETOIF;
1218 if (inp->inp_socket->so_options & SO_BROADCAST)
1219 ipflags |= IP_ALLOWBROADCAST;
1220 if (inp->inp_flags & INP_ONESBCAST)
1221 ipflags |= IP_SENDONES;
1222
1223 #ifdef MAC
1224 mac_inpcb_create_mbuf(inp, m);
1225 #endif
1226
1227 /*
1228 * Set up checksum and output datagram.
1229 */
1230 if (udp_cksum) {
1231 if (inp->inp_flags & INP_ONESBCAST)
1232 faddr.s_addr = INADDR_BROADCAST;
1233 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1234 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1235 m->m_pkthdr.csum_flags = CSUM_UDP;
1236 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1237 } else
1238 ui->ui_sum = 0;
1239 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1240 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
1241 ((struct ip *)ui)->ip_tos = inp->inp_ip_tos; /* XXX */
1242 UDPSTAT_INC(udps_opackets);
1243
1244 if (unlock_udbinfo == 2)
1245 INP_INFO_WUNLOCK(&V_udbinfo);
1246 else if (unlock_udbinfo == 1)
1247 INP_INFO_RUNLOCK(&V_udbinfo);
1248 error = ip_output(m, inp->inp_options, NULL, ipflags,
1249 inp->inp_moptions, inp);
1250 if (unlock_udbinfo == 2)
1251 INP_WUNLOCK(inp);
1252 else
1253 INP_RUNLOCK(inp);
1254 return (error);
1255
1256 release:
1257 if (unlock_udbinfo == 2) {
1258 INP_WUNLOCK(inp);
1259 INP_INFO_WUNLOCK(&V_udbinfo);
1260 } else if (unlock_udbinfo == 1) {
1261 INP_RUNLOCK(inp);
1262 INP_INFO_RUNLOCK(&V_udbinfo);
1263 } else
1264 INP_RUNLOCK(inp);
1265 m_freem(m);
1266 return (error);
1267 }
1268
1269
1270 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1271 #ifdef INET
1272 /*
1273 * Potentially decap ESP in UDP frame. Check for an ESP header
1274 * and optional marker; if present, strip the UDP header and
1275 * push the result through IPSec.
1276 *
1277 * Returns mbuf to be processed (potentially re-allocated) or
1278 * NULL if consumed and/or processed.
1279 */
1280 static struct mbuf *
1281 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1282 {
1283 size_t minlen, payload, skip, iphlen;
1284 caddr_t data;
1285 struct udpcb *up;
1286 struct m_tag *tag;
1287 struct udphdr *udphdr;
1288 struct ip *ip;
1289
1290 INP_RLOCK_ASSERT(inp);
1291
1292 /*
1293 * Pull up data so the longest case is contiguous:
1294 * IP/UDP hdr + non ESP marker + ESP hdr.
1295 */
1296 minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1297 if (minlen > m->m_pkthdr.len)
1298 minlen = m->m_pkthdr.len;
1299 if ((m = m_pullup(m, minlen)) == NULL) {
1300 V_ipsec4stat.in_inval++;
1301 return (NULL); /* Bypass caller processing. */
1302 }
1303 data = mtod(m, caddr_t); /* Points to ip header. */
1304 payload = m->m_len - off; /* Size of payload. */
1305
1306 if (payload == 1 && data[off] == '\xff')
1307 return (m); /* NB: keepalive packet, no decap. */
1308
1309 up = intoudpcb(inp);
1310 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1311 KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1312 ("u_flags 0x%x", up->u_flags));
1313
1314 /*
1315 * Check that the payload is large enough to hold an
1316 * ESP header and compute the amount of data to remove.
1317 *
1318 * NB: the caller has already done a pullup for us.
1319 * XXX can we assume alignment and eliminate bcopys?
1320 */
1321 if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1322 /*
1323 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1324 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1325 * possible AH mode non-IKE marker+non-ESP marker
1326 * from draft-ietf-ipsec-udp-encaps-00.txt.
1327 */
1328 uint64_t marker;
1329
1330 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1331 return (m); /* NB: no decap. */
1332 bcopy(data + off, &marker, sizeof(uint64_t));
1333 if (marker != 0) /* Non-IKE marker. */
1334 return (m); /* NB: no decap. */
1335 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1336 } else {
1337 uint32_t spi;
1338
1339 if (payload <= sizeof(struct esp)) {
1340 V_ipsec4stat.in_inval++;
1341 m_freem(m);
1342 return (NULL); /* Discard. */
1343 }
1344 bcopy(data + off, &spi, sizeof(uint32_t));
1345 if (spi == 0) /* Non-ESP marker. */
1346 return (m); /* NB: no decap. */
1347 skip = sizeof(struct udphdr);
1348 }
1349
1350 /*
1351 * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1352 * the UDP ports. This is required if we want to select
1353 * the right SPD for multiple hosts behind same NAT.
1354 *
1355 * NB: ports are maintained in network byte order everywhere
1356 * in the NAT-T code.
1357 */
1358 tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1359 2 * sizeof(uint16_t), M_NOWAIT);
1360 if (tag == NULL) {
1361 V_ipsec4stat.in_nomem++;
1362 m_freem(m);
1363 return (NULL); /* Discard. */
1364 }
1365 iphlen = off - sizeof(struct udphdr);
1366 udphdr = (struct udphdr *)(data + iphlen);
1367 ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1368 ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1369 m_tag_prepend(m, tag);
1370
1371 /*
1372 * Remove the UDP header (and possibly the non ESP marker)
1373 * IP header length is iphlen
1374 * Before:
1375 * <--- off --->
1376 * +----+------+-----+
1377 * | IP | UDP | ESP |
1378 * +----+------+-----+
1379 * <-skip->
1380 * After:
1381 * +----+-----+
1382 * | IP | ESP |
1383 * +----+-----+
1384 * <-skip->
1385 */
1386 ovbcopy(data, data + skip, iphlen);
1387 m_adj(m, skip);
1388
1389 ip = mtod(m, struct ip *);
1390 ip->ip_len -= skip;
1391 ip->ip_p = IPPROTO_ESP;
1392
1393 /*
1394 * We cannot yet update the cksums so clear any
1395 * h/w cksum flags as they are no longer valid.
1396 */
1397 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1398 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1399
1400 (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1401 return (NULL); /* NB: consumed, bypass processing. */
1402 }
1403 #endif /* INET */
1404 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1405
1406 static void
1407 udp_abort(struct socket *so)
1408 {
1409 struct inpcb *inp;
1410
1411 inp = sotoinpcb(so);
1412 KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1413 INP_INFO_WLOCK(&V_udbinfo);
1414 INP_WLOCK(inp);
1415 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1416 in_pcbdisconnect(inp);
1417 inp->inp_laddr.s_addr = INADDR_ANY;
1418 soisdisconnected(so);
1419 }
1420 INP_WUNLOCK(inp);
1421 INP_INFO_WUNLOCK(&V_udbinfo);
1422 }
1423
1424 static int
1425 udp_attach(struct socket *so, int proto, struct thread *td)
1426 {
1427 struct inpcb *inp;
1428 int error;
1429
1430 inp = sotoinpcb(so);
1431 KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1432 error = soreserve(so, udp_sendspace, udp_recvspace);
1433 if (error)
1434 return (error);
1435 INP_INFO_WLOCK(&V_udbinfo);
1436 error = in_pcballoc(so, &V_udbinfo);
1437 if (error) {
1438 INP_INFO_WUNLOCK(&V_udbinfo);
1439 return (error);
1440 }
1441
1442 inp = sotoinpcb(so);
1443 inp->inp_vflag |= INP_IPV4;
1444 inp->inp_ip_ttl = V_ip_defttl;
1445
1446 error = udp_newudpcb(inp);
1447 if (error) {
1448 in_pcbdetach(inp);
1449 in_pcbfree(inp);
1450 INP_INFO_WUNLOCK(&V_udbinfo);
1451 return (error);
1452 }
1453
1454 INP_WUNLOCK(inp);
1455 INP_INFO_WUNLOCK(&V_udbinfo);
1456 return (0);
1457 }
1458
1459 int
1460 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1461 {
1462 struct inpcb *inp;
1463 struct udpcb *up;
1464
1465 KASSERT(so->so_type == SOCK_DGRAM,
1466 ("udp_set_kernel_tunneling: !dgram"));
1467 inp = sotoinpcb(so);
1468 KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1469 INP_WLOCK(inp);
1470 up = intoudpcb(inp);
1471 if (up->u_tun_func != NULL) {
1472 INP_WUNLOCK(inp);
1473 return (EBUSY);
1474 }
1475 up->u_tun_func = f;
1476 INP_WUNLOCK(inp);
1477 return (0);
1478 }
1479
1480 static int
1481 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1482 {
1483 struct inpcb *inp;
1484 int error;
1485
1486 inp = sotoinpcb(so);
1487 KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1488 INP_INFO_WLOCK(&V_udbinfo);
1489 INP_WLOCK(inp);
1490 error = in_pcbbind(inp, nam, td->td_ucred);
1491 INP_WUNLOCK(inp);
1492 INP_INFO_WUNLOCK(&V_udbinfo);
1493 return (error);
1494 }
1495
1496 static void
1497 udp_close(struct socket *so)
1498 {
1499 struct inpcb *inp;
1500
1501 inp = sotoinpcb(so);
1502 KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1503 INP_INFO_WLOCK(&V_udbinfo);
1504 INP_WLOCK(inp);
1505 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1506 in_pcbdisconnect(inp);
1507 inp->inp_laddr.s_addr = INADDR_ANY;
1508 soisdisconnected(so);
1509 }
1510 INP_WUNLOCK(inp);
1511 INP_INFO_WUNLOCK(&V_udbinfo);
1512 }
1513
1514 static int
1515 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1516 {
1517 struct inpcb *inp;
1518 int error;
1519 struct sockaddr_in *sin;
1520
1521 inp = sotoinpcb(so);
1522 KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1523 INP_INFO_WLOCK(&V_udbinfo);
1524 INP_WLOCK(inp);
1525 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1526 INP_WUNLOCK(inp);
1527 INP_INFO_WUNLOCK(&V_udbinfo);
1528 return (EISCONN);
1529 }
1530 sin = (struct sockaddr_in *)nam;
1531 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1532 if (error != 0) {
1533 INP_WUNLOCK(inp);
1534 INP_INFO_WUNLOCK(&V_udbinfo);
1535 return (error);
1536 }
1537 error = in_pcbconnect(inp, nam, td->td_ucred);
1538 if (error == 0)
1539 soisconnected(so);
1540 INP_WUNLOCK(inp);
1541 INP_INFO_WUNLOCK(&V_udbinfo);
1542 return (error);
1543 }
1544
1545 static void
1546 udp_detach(struct socket *so)
1547 {
1548 struct inpcb *inp;
1549 struct udpcb *up;
1550
1551 inp = sotoinpcb(so);
1552 KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1553 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1554 ("udp_detach: not disconnected"));
1555 INP_INFO_WLOCK(&V_udbinfo);
1556 INP_WLOCK(inp);
1557 up = intoudpcb(inp);
1558 KASSERT(up != NULL, ("%s: up == NULL", __func__));
1559 inp->inp_ppcb = NULL;
1560 in_pcbdetach(inp);
1561 in_pcbfree(inp);
1562 INP_INFO_WUNLOCK(&V_udbinfo);
1563 udp_discardcb(up);
1564 }
1565
1566 static int
1567 udp_disconnect(struct socket *so)
1568 {
1569 struct inpcb *inp;
1570
1571 inp = sotoinpcb(so);
1572 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1573 INP_INFO_WLOCK(&V_udbinfo);
1574 INP_WLOCK(inp);
1575 if (inp->inp_faddr.s_addr == INADDR_ANY) {
1576 INP_WUNLOCK(inp);
1577 INP_INFO_WUNLOCK(&V_udbinfo);
1578 return (ENOTCONN);
1579 }
1580
1581 in_pcbdisconnect(inp);
1582 inp->inp_laddr.s_addr = INADDR_ANY;
1583 SOCK_LOCK(so);
1584 so->so_state &= ~SS_ISCONNECTED; /* XXX */
1585 SOCK_UNLOCK(so);
1586 INP_WUNLOCK(inp);
1587 INP_INFO_WUNLOCK(&V_udbinfo);
1588 return (0);
1589 }
1590
1591 static int
1592 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1593 struct mbuf *control, struct thread *td)
1594 {
1595 struct inpcb *inp;
1596
1597 inp = sotoinpcb(so);
1598 KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1599 return (udp_output(inp, m, addr, control, td));
1600 }
1601
1602 int
1603 udp_shutdown(struct socket *so)
1604 {
1605 struct inpcb *inp;
1606
1607 inp = sotoinpcb(so);
1608 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1609 INP_WLOCK(inp);
1610 socantsendmore(so);
1611 INP_WUNLOCK(inp);
1612 return (0);
1613 }
1614
1615 struct pr_usrreqs udp_usrreqs = {
1616 .pru_abort = udp_abort,
1617 .pru_attach = udp_attach,
1618 .pru_bind = udp_bind,
1619 .pru_connect = udp_connect,
1620 .pru_control = in_control,
1621 .pru_detach = udp_detach,
1622 .pru_disconnect = udp_disconnect,
1623 .pru_peeraddr = in_getpeeraddr,
1624 .pru_send = udp_send,
1625 .pru_soreceive = soreceive_dgram,
1626 .pru_sosend = sosend_dgram,
1627 .pru_shutdown = udp_shutdown,
1628 .pru_sockaddr = in_getsockaddr,
1629 .pru_sosetlabel = in_pcbsosetlabel,
1630 .pru_close = udp_close,
1631 };
Cache object: eb7ab8b0183183864d08811bef8bfce3
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