1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3 * The Regents of the University of California.
4 * Copyright (c) 2008 Robert N. M. Watson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 4. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)udp_usrreq.c 8.6 (Berkeley) 5/23/95
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36
37 #include "opt_ipfw.h"
38 #include "opt_inet6.h"
39 #include "opt_ipsec.h"
40
41 #include <sys/param.h>
42 #include <sys/domain.h>
43 #include <sys/eventhandler.h>
44 #include <sys/jail.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/protosw.h>
52 #include <sys/signalvar.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57 #include <sys/syslog.h>
58 #include <sys/systm.h>
59
60 #include <vm/uma.h>
61
62 #include <net/if.h>
63 #include <net/route.h>
64
65 #include <netinet/in.h>
66 #include <netinet/in_pcb.h>
67 #include <netinet/in_systm.h>
68 #include <netinet/in_var.h>
69 #include <netinet/ip.h>
70 #ifdef INET6
71 #include <netinet/ip6.h>
72 #endif
73 #include <netinet/ip_icmp.h>
74 #include <netinet/icmp_var.h>
75 #include <netinet/ip_var.h>
76 #include <netinet/ip_options.h>
77 #ifdef INET6
78 #include <netinet6/ip6_var.h>
79 #endif
80 #include <netinet/udp.h>
81 #include <netinet/udp_var.h>
82
83 #ifdef IPSEC
84 #include <netipsec/ipsec.h>
85 #include <netipsec/esp.h>
86 #endif
87
88 #include <machine/in_cksum.h>
89
90 #include <security/mac/mac_framework.h>
91
92 /*
93 * UDP protocol implementation.
94 * Per RFC 768, August, 1980.
95 */
96
97 /*
98 * BSD 4.2 defaulted the udp checksum to be off. Turning off udp checksums
99 * removes the only data integrity mechanism for packets and malformed
100 * packets that would otherwise be discarded due to bad checksums, and may
101 * cause problems (especially for NFS data blocks).
102 */
103 VNET_DEFINE(int, udp_cksum) = 1;
104 SYSCTL_VNET_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
105 &VNET_NAME(udp_cksum), 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 * Detached PCBs can linger in the list if someone
499 * holds a reference. (e.g. udp_pcblist)
500 */
501 if (inp->inp_socket == NULL) {
502 INP_RUNLOCK(inp);
503 continue;
504 }
505
506 /*
507 * Handle socket delivery policy for any-source
508 * and source-specific multicast. [RFC3678]
509 */
510 imo = inp->inp_moptions;
511 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
512 imo != NULL) {
513 struct sockaddr_in group;
514 int blocked;
515
516 bzero(&group, sizeof(struct sockaddr_in));
517 group.sin_len = sizeof(struct sockaddr_in);
518 group.sin_family = AF_INET;
519 group.sin_addr = ip->ip_dst;
520
521 blocked = imo_multi_filter(imo, ifp,
522 (struct sockaddr *)&group,
523 (struct sockaddr *)&udp_in);
524 if (blocked != MCAST_PASS) {
525 if (blocked == MCAST_NOTGMEMBER)
526 IPSTAT_INC(ips_notmember);
527 if (blocked == MCAST_NOTSMEMBER ||
528 blocked == MCAST_MUTED)
529 UDPSTAT_INC(udps_filtermcast);
530 INP_RUNLOCK(inp);
531 continue;
532 }
533 }
534 if (last != NULL) {
535 struct mbuf *n;
536
537 n = m_copy(m, 0, M_COPYALL);
538 up = intoudpcb(last);
539 if (up->u_tun_func == NULL) {
540 if (n != NULL)
541 udp_append(last,
542 ip, n,
543 iphlen +
544 sizeof(struct udphdr),
545 &udp_in);
546 } else {
547 /*
548 * Engage the tunneling protocol we
549 * will have to leave the info_lock
550 * up, since we are hunting through
551 * multiple UDP's.
552 */
553
554 (*up->u_tun_func)(n, iphlen, last);
555 }
556 INP_RUNLOCK(last);
557 }
558 last = inp;
559 /*
560 * Don't look for additional matches if this one does
561 * not have either the SO_REUSEPORT or SO_REUSEADDR
562 * socket options set. This heuristic avoids
563 * searching through all pcbs in the common case of a
564 * non-shared port. It assumes that an application
565 * will never clear these options after setting them.
566 */
567 if ((last->inp_socket->so_options &
568 (SO_REUSEPORT|SO_REUSEADDR)) == 0)
569 break;
570 }
571
572 if (last == NULL) {
573 /*
574 * No matching pcb found; discard datagram. (No need
575 * to send an ICMP Port Unreachable for a broadcast
576 * or multicast datgram.)
577 */
578 UDPSTAT_INC(udps_noportbcast);
579 goto badheadlocked;
580 }
581 up = intoudpcb(last);
582 if (up->u_tun_func == NULL) {
583 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
584 &udp_in);
585 } else {
586 /*
587 * Engage the tunneling protocol.
588 */
589 (*up->u_tun_func)(m, iphlen, last);
590 }
591 INP_RUNLOCK(last);
592 INP_INFO_RUNLOCK(&V_udbinfo);
593 return;
594 }
595
596 /*
597 * Locate pcb for datagram.
598 */
599 inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
600 ip->ip_dst, uh->uh_dport, 1, ifp);
601 if (inp == NULL) {
602 if (udp_log_in_vain) {
603 char buf[4*sizeof "123"];
604
605 strcpy(buf, inet_ntoa(ip->ip_dst));
606 log(LOG_INFO,
607 "Connection attempt to UDP %s:%d from %s:%d\n",
608 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
609 ntohs(uh->uh_sport));
610 }
611 UDPSTAT_INC(udps_noport);
612 if (m->m_flags & (M_BCAST | M_MCAST)) {
613 UDPSTAT_INC(udps_noportbcast);
614 goto badheadlocked;
615 }
616 if (V_udp_blackhole)
617 goto badheadlocked;
618 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
619 goto badheadlocked;
620 *ip = save_ip;
621 ip->ip_len += iphlen;
622 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
623 INP_INFO_RUNLOCK(&V_udbinfo);
624 return;
625 }
626
627 /*
628 * Check the minimum TTL for socket.
629 */
630 INP_RLOCK(inp);
631 INP_INFO_RUNLOCK(&V_udbinfo);
632
633 /*
634 * Detached PCBs can linger in the hash table if someone holds a
635 * reference. (e.g. udp_pcblist)
636 */
637 if (inp->inp_socket == NULL) {
638 INP_RUNLOCK(inp);
639 goto badunlocked;
640 }
641 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
642 INP_RUNLOCK(inp);
643 goto badunlocked;
644 }
645 up = intoudpcb(inp);
646 if (up->u_tun_func == NULL) {
647 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
648 } else {
649 /*
650 * Engage the tunneling protocol.
651 */
652
653 (*up->u_tun_func)(m, iphlen, inp);
654 }
655 INP_RUNLOCK(inp);
656 return;
657
658 badheadlocked:
659 if (inp)
660 INP_RUNLOCK(inp);
661 INP_INFO_RUNLOCK(&V_udbinfo);
662 badunlocked:
663 m_freem(m);
664 }
665
666 /*
667 * Notify a udp user of an asynchronous error; just wake up so that they can
668 * collect error status.
669 */
670 struct inpcb *
671 udp_notify(struct inpcb *inp, int errno)
672 {
673
674 /*
675 * While udp_ctlinput() always calls udp_notify() with a read lock
676 * when invoking it directly, in_pcbnotifyall() currently uses write
677 * locks due to sharing code with TCP. For now, accept either a read
678 * or a write lock, but a read lock is sufficient.
679 */
680 INP_LOCK_ASSERT(inp);
681
682 inp->inp_socket->so_error = errno;
683 sorwakeup(inp->inp_socket);
684 sowwakeup(inp->inp_socket);
685 return (inp);
686 }
687
688 void
689 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
690 {
691 struct ip *ip = vip;
692 struct udphdr *uh;
693 struct in_addr faddr;
694 struct inpcb *inp;
695
696 faddr = ((struct sockaddr_in *)sa)->sin_addr;
697 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
698 return;
699
700 /*
701 * Redirects don't need to be handled up here.
702 */
703 if (PRC_IS_REDIRECT(cmd))
704 return;
705
706 /*
707 * Hostdead is ugly because it goes linearly through all PCBs.
708 *
709 * XXX: We never get this from ICMP, otherwise it makes an excellent
710 * DoS attack on machines with many connections.
711 */
712 if (cmd == PRC_HOSTDEAD)
713 ip = NULL;
714 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
715 return;
716 if (ip != NULL) {
717 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
718 INP_INFO_RLOCK(&V_udbinfo);
719 inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
720 ip->ip_src, uh->uh_sport, 0, NULL);
721 if (inp != NULL) {
722 INP_RLOCK(inp);
723 if (inp->inp_socket != NULL) {
724 udp_notify(inp, inetctlerrmap[cmd]);
725 }
726 INP_RUNLOCK(inp);
727 }
728 INP_INFO_RUNLOCK(&V_udbinfo);
729 } else
730 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
731 udp_notify);
732 }
733
734 static int
735 udp_pcblist(SYSCTL_HANDLER_ARGS)
736 {
737 int error, i, n;
738 struct inpcb *inp, **inp_list;
739 inp_gen_t gencnt;
740 struct xinpgen xig;
741
742 /*
743 * The process of preparing the PCB list is too time-consuming and
744 * resource-intensive to repeat twice on every request.
745 */
746 if (req->oldptr == 0) {
747 n = V_udbinfo.ipi_count;
748 n += imax(n / 8, 10);
749 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
750 return (0);
751 }
752
753 if (req->newptr != 0)
754 return (EPERM);
755
756 /*
757 * OK, now we're committed to doing something.
758 */
759 INP_INFO_RLOCK(&V_udbinfo);
760 gencnt = V_udbinfo.ipi_gencnt;
761 n = V_udbinfo.ipi_count;
762 INP_INFO_RUNLOCK(&V_udbinfo);
763
764 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
765 + n * sizeof(struct xinpcb));
766 if (error != 0)
767 return (error);
768
769 xig.xig_len = sizeof xig;
770 xig.xig_count = n;
771 xig.xig_gen = gencnt;
772 xig.xig_sogen = so_gencnt;
773 error = SYSCTL_OUT(req, &xig, sizeof xig);
774 if (error)
775 return (error);
776
777 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
778 if (inp_list == 0)
779 return (ENOMEM);
780
781 INP_INFO_RLOCK(&V_udbinfo);
782 for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
783 inp = LIST_NEXT(inp, inp_list)) {
784 INP_WLOCK(inp);
785 if (inp->inp_gencnt <= gencnt &&
786 cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
787 in_pcbref(inp);
788 inp_list[i++] = inp;
789 }
790 INP_WUNLOCK(inp);
791 }
792 INP_INFO_RUNLOCK(&V_udbinfo);
793 n = i;
794
795 error = 0;
796 for (i = 0; i < n; i++) {
797 inp = inp_list[i];
798 INP_RLOCK(inp);
799 if (inp->inp_gencnt <= gencnt) {
800 struct xinpcb xi;
801
802 bzero(&xi, sizeof(xi));
803 xi.xi_len = sizeof xi;
804 /* XXX should avoid extra copy */
805 bcopy(inp, &xi.xi_inp, sizeof *inp);
806 if (inp->inp_socket)
807 sotoxsocket(inp->inp_socket, &xi.xi_socket);
808 xi.xi_inp.inp_gencnt = inp->inp_gencnt;
809 INP_RUNLOCK(inp);
810 error = SYSCTL_OUT(req, &xi, sizeof xi);
811 } else
812 INP_RUNLOCK(inp);
813 }
814 INP_INFO_WLOCK(&V_udbinfo);
815 for (i = 0; i < n; i++) {
816 inp = inp_list[i];
817 INP_WLOCK(inp);
818 if (!in_pcbrele(inp))
819 INP_WUNLOCK(inp);
820 }
821 INP_INFO_WUNLOCK(&V_udbinfo);
822
823 if (!error) {
824 /*
825 * Give the user an updated idea of our state. If the
826 * generation differs from what we told her before, she knows
827 * that something happened while we were processing this
828 * request, and it might be necessary to retry.
829 */
830 INP_INFO_RLOCK(&V_udbinfo);
831 xig.xig_gen = V_udbinfo.ipi_gencnt;
832 xig.xig_sogen = so_gencnt;
833 xig.xig_count = V_udbinfo.ipi_count;
834 INP_INFO_RUNLOCK(&V_udbinfo);
835 error = SYSCTL_OUT(req, &xig, sizeof xig);
836 }
837 free(inp_list, M_TEMP);
838 return (error);
839 }
840
841 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
842 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
843 udp_pcblist, "S,xinpcb", "List of active UDP sockets");
844
845 static int
846 udp_getcred(SYSCTL_HANDLER_ARGS)
847 {
848 struct xucred xuc;
849 struct sockaddr_in addrs[2];
850 struct inpcb *inp;
851 int error;
852
853 error = priv_check(req->td, PRIV_NETINET_GETCRED);
854 if (error)
855 return (error);
856 error = SYSCTL_IN(req, addrs, sizeof(addrs));
857 if (error)
858 return (error);
859 INP_INFO_RLOCK(&V_udbinfo);
860 inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
861 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
862 if (inp != NULL) {
863 INP_RLOCK(inp);
864 INP_INFO_RUNLOCK(&V_udbinfo);
865 if (inp->inp_socket == NULL)
866 error = ENOENT;
867 if (error == 0)
868 error = cr_canseeinpcb(req->td->td_ucred, inp);
869 if (error == 0)
870 cru2x(inp->inp_cred, &xuc);
871 INP_RUNLOCK(inp);
872 } else {
873 INP_INFO_RUNLOCK(&V_udbinfo);
874 error = ENOENT;
875 }
876 if (error == 0)
877 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
878 return (error);
879 }
880
881 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
882 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
883 udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
884
885 int
886 udp_ctloutput(struct socket *so, struct sockopt *sopt)
887 {
888 int error = 0, optval;
889 struct inpcb *inp;
890 #ifdef IPSEC_NAT_T
891 struct udpcb *up;
892 #endif
893
894 inp = sotoinpcb(so);
895 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
896 INP_WLOCK(inp);
897 if (sopt->sopt_level != IPPROTO_UDP) {
898 #ifdef INET6
899 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
900 INP_WUNLOCK(inp);
901 error = ip6_ctloutput(so, sopt);
902 } else {
903 #endif
904 INP_WUNLOCK(inp);
905 error = ip_ctloutput(so, sopt);
906 #ifdef INET6
907 }
908 #endif
909 return (error);
910 }
911
912 switch (sopt->sopt_dir) {
913 case SOPT_SET:
914 switch (sopt->sopt_name) {
915 case UDP_ENCAP:
916 INP_WUNLOCK(inp);
917 error = sooptcopyin(sopt, &optval, sizeof optval,
918 sizeof optval);
919 if (error)
920 break;
921 inp = sotoinpcb(so);
922 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
923 INP_WLOCK(inp);
924 #ifdef IPSEC_NAT_T
925 up = intoudpcb(inp);
926 KASSERT(up != NULL, ("%s: up == NULL", __func__));
927 #endif
928 switch (optval) {
929 case 0:
930 /* Clear all UDP encap. */
931 #ifdef IPSEC_NAT_T
932 up->u_flags &= ~UF_ESPINUDP_ALL;
933 #endif
934 break;
935 #ifdef IPSEC_NAT_T
936 case UDP_ENCAP_ESPINUDP:
937 case UDP_ENCAP_ESPINUDP_NON_IKE:
938 up->u_flags &= ~UF_ESPINUDP_ALL;
939 if (optval == UDP_ENCAP_ESPINUDP)
940 up->u_flags |= UF_ESPINUDP;
941 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
942 up->u_flags |= UF_ESPINUDP_NON_IKE;
943 break;
944 #endif
945 default:
946 error = EINVAL;
947 break;
948 }
949 INP_WUNLOCK(inp);
950 break;
951 default:
952 INP_WUNLOCK(inp);
953 error = ENOPROTOOPT;
954 break;
955 }
956 break;
957 case SOPT_GET:
958 switch (sopt->sopt_name) {
959 #ifdef IPSEC_NAT_T
960 case UDP_ENCAP:
961 up = intoudpcb(inp);
962 KASSERT(up != NULL, ("%s: up == NULL", __func__));
963 optval = up->u_flags & UF_ESPINUDP_ALL;
964 INP_WUNLOCK(inp);
965 error = sooptcopyout(sopt, &optval, sizeof optval);
966 break;
967 #endif
968 default:
969 INP_WUNLOCK(inp);
970 error = ENOPROTOOPT;
971 break;
972 }
973 break;
974 }
975 return (error);
976 }
977
978 static int
979 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
980 struct mbuf *control, struct thread *td)
981 {
982 struct udpiphdr *ui;
983 int len = m->m_pkthdr.len;
984 struct in_addr faddr, laddr;
985 struct cmsghdr *cm;
986 struct sockaddr_in *sin, src;
987 int error = 0;
988 int ipflags;
989 u_short fport, lport;
990 int unlock_udbinfo;
991 u_char tos;
992
993 /*
994 * udp_output() may need to temporarily bind or connect the current
995 * inpcb. As such, we don't know up front whether we will need the
996 * pcbinfo lock or not. Do any work to decide what is needed up
997 * front before acquiring any locks.
998 */
999 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1000 if (control)
1001 m_freem(control);
1002 m_freem(m);
1003 return (EMSGSIZE);
1004 }
1005
1006 src.sin_family = 0;
1007 tos = inp->inp_ip_tos;
1008 if (control != NULL) {
1009 /*
1010 * XXX: Currently, we assume all the optional information is
1011 * stored in a single mbuf.
1012 */
1013 if (control->m_next) {
1014 m_freem(control);
1015 m_freem(m);
1016 return (EINVAL);
1017 }
1018 for (; control->m_len > 0;
1019 control->m_data += CMSG_ALIGN(cm->cmsg_len),
1020 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1021 cm = mtod(control, struct cmsghdr *);
1022 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1023 || cm->cmsg_len > control->m_len) {
1024 error = EINVAL;
1025 break;
1026 }
1027 if (cm->cmsg_level != IPPROTO_IP)
1028 continue;
1029
1030 switch (cm->cmsg_type) {
1031 case IP_SENDSRCADDR:
1032 if (cm->cmsg_len !=
1033 CMSG_LEN(sizeof(struct in_addr))) {
1034 error = EINVAL;
1035 break;
1036 }
1037 bzero(&src, sizeof(src));
1038 src.sin_family = AF_INET;
1039 src.sin_len = sizeof(src);
1040 src.sin_port = inp->inp_lport;
1041 src.sin_addr =
1042 *(struct in_addr *)CMSG_DATA(cm);
1043 break;
1044
1045 case IP_TOS:
1046 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1047 error = EINVAL;
1048 break;
1049 }
1050 tos = *(u_char *)CMSG_DATA(cm);
1051 break;
1052
1053 default:
1054 error = ENOPROTOOPT;
1055 break;
1056 }
1057 if (error)
1058 break;
1059 }
1060 m_freem(control);
1061 }
1062 if (error) {
1063 m_freem(m);
1064 return (error);
1065 }
1066
1067 /*
1068 * Depending on whether or not the application has bound or connected
1069 * the socket, we may have to do varying levels of work. The optimal
1070 * case is for a connected UDP socket, as a global lock isn't
1071 * required at all.
1072 *
1073 * In order to decide which we need, we require stability of the
1074 * inpcb binding, which we ensure by acquiring a read lock on the
1075 * inpcb. This doesn't strictly follow the lock order, so we play
1076 * the trylock and retry game; note that we may end up with more
1077 * conservative locks than required the second time around, so later
1078 * assertions have to accept that. Further analysis of the number of
1079 * misses under contention is required.
1080 */
1081 sin = (struct sockaddr_in *)addr;
1082 INP_RLOCK(inp);
1083 if (sin != NULL &&
1084 (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1085 INP_RUNLOCK(inp);
1086 INP_INFO_WLOCK(&V_udbinfo);
1087 INP_WLOCK(inp);
1088 unlock_udbinfo = 2;
1089 } else if ((sin != NULL && (
1090 (sin->sin_addr.s_addr == INADDR_ANY) ||
1091 (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1092 (inp->inp_laddr.s_addr == INADDR_ANY) ||
1093 (inp->inp_lport == 0))) ||
1094 (src.sin_family == AF_INET)) {
1095 if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
1096 INP_RUNLOCK(inp);
1097 INP_INFO_RLOCK(&V_udbinfo);
1098 INP_RLOCK(inp);
1099 }
1100 unlock_udbinfo = 1;
1101 } else
1102 unlock_udbinfo = 0;
1103
1104 /*
1105 * If the IP_SENDSRCADDR control message was specified, override the
1106 * source address for this datagram. Its use is invalidated if the
1107 * address thus specified is incomplete or clobbers other inpcbs.
1108 */
1109 laddr = inp->inp_laddr;
1110 lport = inp->inp_lport;
1111 if (src.sin_family == AF_INET) {
1112 INP_INFO_LOCK_ASSERT(&V_udbinfo);
1113 if ((lport == 0) ||
1114 (laddr.s_addr == INADDR_ANY &&
1115 src.sin_addr.s_addr == INADDR_ANY)) {
1116 error = EINVAL;
1117 goto release;
1118 }
1119 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1120 &laddr.s_addr, &lport, td->td_ucred);
1121 if (error)
1122 goto release;
1123 }
1124
1125 /*
1126 * If a UDP socket has been connected, then a local address/port will
1127 * have been selected and bound.
1128 *
1129 * If a UDP socket has not been connected to, then an explicit
1130 * destination address must be used, in which case a local
1131 * address/port may not have been selected and bound.
1132 */
1133 if (sin != NULL) {
1134 INP_LOCK_ASSERT(inp);
1135 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1136 error = EISCONN;
1137 goto release;
1138 }
1139
1140 /*
1141 * Jail may rewrite the destination address, so let it do
1142 * that before we use it.
1143 */
1144 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1145 if (error)
1146 goto release;
1147
1148 /*
1149 * If a local address or port hasn't yet been selected, or if
1150 * the destination address needs to be rewritten due to using
1151 * a special INADDR_ constant, invoke in_pcbconnect_setup()
1152 * to do the heavy lifting. Once a port is selected, we
1153 * commit the binding back to the socket; we also commit the
1154 * binding of the address if in jail.
1155 *
1156 * If we already have a valid binding and we're not
1157 * requesting a destination address rewrite, use a fast path.
1158 */
1159 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1160 inp->inp_lport == 0 ||
1161 sin->sin_addr.s_addr == INADDR_ANY ||
1162 sin->sin_addr.s_addr == INADDR_BROADCAST) {
1163 INP_INFO_LOCK_ASSERT(&V_udbinfo);
1164 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1165 &lport, &faddr.s_addr, &fport, NULL,
1166 td->td_ucred);
1167 if (error)
1168 goto release;
1169
1170 /*
1171 * XXXRW: Why not commit the port if the address is
1172 * !INADDR_ANY?
1173 */
1174 /* Commit the local port if newly assigned. */
1175 if (inp->inp_laddr.s_addr == INADDR_ANY &&
1176 inp->inp_lport == 0) {
1177 INP_INFO_WLOCK_ASSERT(&V_udbinfo);
1178 INP_WLOCK_ASSERT(inp);
1179 /*
1180 * Remember addr if jailed, to prevent
1181 * rebinding.
1182 */
1183 if (prison_flag(td->td_ucred, PR_IP4))
1184 inp->inp_laddr = laddr;
1185 inp->inp_lport = lport;
1186 if (in_pcbinshash(inp) != 0) {
1187 inp->inp_lport = 0;
1188 error = EAGAIN;
1189 goto release;
1190 }
1191 inp->inp_flags |= INP_ANONPORT;
1192 }
1193 } else {
1194 faddr = sin->sin_addr;
1195 fport = sin->sin_port;
1196 }
1197 } else {
1198 INP_LOCK_ASSERT(inp);
1199 faddr = inp->inp_faddr;
1200 fport = inp->inp_fport;
1201 if (faddr.s_addr == INADDR_ANY) {
1202 error = ENOTCONN;
1203 goto release;
1204 }
1205 }
1206
1207 /*
1208 * Calculate data length and get a mbuf for UDP, IP, and possible
1209 * link-layer headers. Immediate slide the data pointer back forward
1210 * since we won't use that space at this layer.
1211 */
1212 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1213 if (m == NULL) {
1214 error = ENOBUFS;
1215 goto release;
1216 }
1217 m->m_data += max_linkhdr;
1218 m->m_len -= max_linkhdr;
1219 m->m_pkthdr.len -= max_linkhdr;
1220
1221 /*
1222 * Fill in mbuf with extended UDP header and addresses and length put
1223 * into network format.
1224 */
1225 ui = mtod(m, struct udpiphdr *);
1226 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */
1227 ui->ui_pr = IPPROTO_UDP;
1228 ui->ui_src = laddr;
1229 ui->ui_dst = faddr;
1230 ui->ui_sport = lport;
1231 ui->ui_dport = fport;
1232 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1233
1234 /*
1235 * Set the Don't Fragment bit in the IP header.
1236 */
1237 if (inp->inp_flags & INP_DONTFRAG) {
1238 struct ip *ip;
1239
1240 ip = (struct ip *)&ui->ui_i;
1241 ip->ip_off |= IP_DF;
1242 }
1243
1244 ipflags = 0;
1245 if (inp->inp_socket->so_options & SO_DONTROUTE)
1246 ipflags |= IP_ROUTETOIF;
1247 if (inp->inp_socket->so_options & SO_BROADCAST)
1248 ipflags |= IP_ALLOWBROADCAST;
1249 if (inp->inp_flags & INP_ONESBCAST)
1250 ipflags |= IP_SENDONES;
1251
1252 #ifdef MAC
1253 mac_inpcb_create_mbuf(inp, m);
1254 #endif
1255
1256 /*
1257 * Set up checksum and output datagram.
1258 */
1259 if (V_udp_cksum) {
1260 if (inp->inp_flags & INP_ONESBCAST)
1261 faddr.s_addr = INADDR_BROADCAST;
1262 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1263 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1264 m->m_pkthdr.csum_flags = CSUM_UDP;
1265 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1266 } else
1267 ui->ui_sum = 0;
1268 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1269 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
1270 ((struct ip *)ui)->ip_tos = tos; /* XXX */
1271 UDPSTAT_INC(udps_opackets);
1272
1273 if (unlock_udbinfo == 2)
1274 INP_INFO_WUNLOCK(&V_udbinfo);
1275 else if (unlock_udbinfo == 1)
1276 INP_INFO_RUNLOCK(&V_udbinfo);
1277 error = ip_output(m, inp->inp_options, NULL, ipflags,
1278 inp->inp_moptions, inp);
1279 if (unlock_udbinfo == 2)
1280 INP_WUNLOCK(inp);
1281 else
1282 INP_RUNLOCK(inp);
1283 return (error);
1284
1285 release:
1286 if (unlock_udbinfo == 2) {
1287 INP_WUNLOCK(inp);
1288 INP_INFO_WUNLOCK(&V_udbinfo);
1289 } else if (unlock_udbinfo == 1) {
1290 INP_RUNLOCK(inp);
1291 INP_INFO_RUNLOCK(&V_udbinfo);
1292 } else
1293 INP_RUNLOCK(inp);
1294 m_freem(m);
1295 return (error);
1296 }
1297
1298
1299 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1300 #ifdef INET
1301 /*
1302 * Potentially decap ESP in UDP frame. Check for an ESP header
1303 * and optional marker; if present, strip the UDP header and
1304 * push the result through IPSec.
1305 *
1306 * Returns mbuf to be processed (potentially re-allocated) or
1307 * NULL if consumed and/or processed.
1308 */
1309 static struct mbuf *
1310 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1311 {
1312 size_t minlen, payload, skip, iphlen;
1313 caddr_t data;
1314 struct udpcb *up;
1315 struct m_tag *tag;
1316 struct udphdr *udphdr;
1317 struct ip *ip;
1318
1319 INP_RLOCK_ASSERT(inp);
1320
1321 /*
1322 * Pull up data so the longest case is contiguous:
1323 * IP/UDP hdr + non ESP marker + ESP hdr.
1324 */
1325 minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1326 if (minlen > m->m_pkthdr.len)
1327 minlen = m->m_pkthdr.len;
1328 if ((m = m_pullup(m, minlen)) == NULL) {
1329 V_ipsec4stat.in_inval++;
1330 return (NULL); /* Bypass caller processing. */
1331 }
1332 data = mtod(m, caddr_t); /* Points to ip header. */
1333 payload = m->m_len - off; /* Size of payload. */
1334
1335 if (payload == 1 && data[off] == '\xff')
1336 return (m); /* NB: keepalive packet, no decap. */
1337
1338 up = intoudpcb(inp);
1339 KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1340 KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1341 ("u_flags 0x%x", up->u_flags));
1342
1343 /*
1344 * Check that the payload is large enough to hold an
1345 * ESP header and compute the amount of data to remove.
1346 *
1347 * NB: the caller has already done a pullup for us.
1348 * XXX can we assume alignment and eliminate bcopys?
1349 */
1350 if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1351 /*
1352 * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1353 * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1354 * possible AH mode non-IKE marker+non-ESP marker
1355 * from draft-ietf-ipsec-udp-encaps-00.txt.
1356 */
1357 uint64_t marker;
1358
1359 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1360 return (m); /* NB: no decap. */
1361 bcopy(data + off, &marker, sizeof(uint64_t));
1362 if (marker != 0) /* Non-IKE marker. */
1363 return (m); /* NB: no decap. */
1364 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1365 } else {
1366 uint32_t spi;
1367
1368 if (payload <= sizeof(struct esp)) {
1369 V_ipsec4stat.in_inval++;
1370 m_freem(m);
1371 return (NULL); /* Discard. */
1372 }
1373 bcopy(data + off, &spi, sizeof(uint32_t));
1374 if (spi == 0) /* Non-ESP marker. */
1375 return (m); /* NB: no decap. */
1376 skip = sizeof(struct udphdr);
1377 }
1378
1379 /*
1380 * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1381 * the UDP ports. This is required if we want to select
1382 * the right SPD for multiple hosts behind same NAT.
1383 *
1384 * NB: ports are maintained in network byte order everywhere
1385 * in the NAT-T code.
1386 */
1387 tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1388 2 * sizeof(uint16_t), M_NOWAIT);
1389 if (tag == NULL) {
1390 V_ipsec4stat.in_nomem++;
1391 m_freem(m);
1392 return (NULL); /* Discard. */
1393 }
1394 iphlen = off - sizeof(struct udphdr);
1395 udphdr = (struct udphdr *)(data + iphlen);
1396 ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1397 ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1398 m_tag_prepend(m, tag);
1399
1400 /*
1401 * Remove the UDP header (and possibly the non ESP marker)
1402 * IP header length is iphlen
1403 * Before:
1404 * <--- off --->
1405 * +----+------+-----+
1406 * | IP | UDP | ESP |
1407 * +----+------+-----+
1408 * <-skip->
1409 * After:
1410 * +----+-----+
1411 * | IP | ESP |
1412 * +----+-----+
1413 * <-skip->
1414 */
1415 ovbcopy(data, data + skip, iphlen);
1416 m_adj(m, skip);
1417
1418 ip = mtod(m, struct ip *);
1419 ip->ip_len -= skip;
1420 ip->ip_p = IPPROTO_ESP;
1421
1422 /*
1423 * We cannot yet update the cksums so clear any
1424 * h/w cksum flags as they are no longer valid.
1425 */
1426 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1427 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1428
1429 (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1430 return (NULL); /* NB: consumed, bypass processing. */
1431 }
1432 #endif /* INET */
1433 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1434
1435 static void
1436 udp_abort(struct socket *so)
1437 {
1438 struct inpcb *inp;
1439
1440 inp = sotoinpcb(so);
1441 KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1442 INP_INFO_WLOCK(&V_udbinfo);
1443 INP_WLOCK(inp);
1444 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1445 in_pcbdisconnect(inp);
1446 inp->inp_laddr.s_addr = INADDR_ANY;
1447 soisdisconnected(so);
1448 }
1449 INP_WUNLOCK(inp);
1450 INP_INFO_WUNLOCK(&V_udbinfo);
1451 }
1452
1453 static int
1454 udp_attach(struct socket *so, int proto, struct thread *td)
1455 {
1456 struct inpcb *inp;
1457 int error;
1458
1459 inp = sotoinpcb(so);
1460 KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1461 error = soreserve(so, udp_sendspace, udp_recvspace);
1462 if (error)
1463 return (error);
1464 INP_INFO_WLOCK(&V_udbinfo);
1465 error = in_pcballoc(so, &V_udbinfo);
1466 if (error) {
1467 INP_INFO_WUNLOCK(&V_udbinfo);
1468 return (error);
1469 }
1470
1471 inp = sotoinpcb(so);
1472 inp->inp_vflag |= INP_IPV4;
1473 inp->inp_ip_ttl = V_ip_defttl;
1474
1475 error = udp_newudpcb(inp);
1476 if (error) {
1477 in_pcbdetach(inp);
1478 in_pcbfree(inp);
1479 INP_INFO_WUNLOCK(&V_udbinfo);
1480 return (error);
1481 }
1482
1483 INP_WUNLOCK(inp);
1484 INP_INFO_WUNLOCK(&V_udbinfo);
1485 return (0);
1486 }
1487
1488 int
1489 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1490 {
1491 struct inpcb *inp;
1492 struct udpcb *up;
1493
1494 KASSERT(so->so_type == SOCK_DGRAM,
1495 ("udp_set_kernel_tunneling: !dgram"));
1496 inp = sotoinpcb(so);
1497 KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1498 INP_WLOCK(inp);
1499 up = intoudpcb(inp);
1500 if (up->u_tun_func != NULL) {
1501 INP_WUNLOCK(inp);
1502 return (EBUSY);
1503 }
1504 up->u_tun_func = f;
1505 INP_WUNLOCK(inp);
1506 return (0);
1507 }
1508
1509 static int
1510 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1511 {
1512 struct inpcb *inp;
1513 int error;
1514
1515 inp = sotoinpcb(so);
1516 KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1517 INP_INFO_WLOCK(&V_udbinfo);
1518 INP_WLOCK(inp);
1519 error = in_pcbbind(inp, nam, td->td_ucred);
1520 INP_WUNLOCK(inp);
1521 INP_INFO_WUNLOCK(&V_udbinfo);
1522 return (error);
1523 }
1524
1525 static void
1526 udp_close(struct socket *so)
1527 {
1528 struct inpcb *inp;
1529
1530 inp = sotoinpcb(so);
1531 KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1532 INP_INFO_WLOCK(&V_udbinfo);
1533 INP_WLOCK(inp);
1534 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1535 in_pcbdisconnect(inp);
1536 inp->inp_laddr.s_addr = INADDR_ANY;
1537 soisdisconnected(so);
1538 }
1539 INP_WUNLOCK(inp);
1540 INP_INFO_WUNLOCK(&V_udbinfo);
1541 }
1542
1543 static int
1544 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1545 {
1546 struct inpcb *inp;
1547 int error;
1548 struct sockaddr_in *sin;
1549
1550 inp = sotoinpcb(so);
1551 KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1552 INP_INFO_WLOCK(&V_udbinfo);
1553 INP_WLOCK(inp);
1554 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1555 INP_WUNLOCK(inp);
1556 INP_INFO_WUNLOCK(&V_udbinfo);
1557 return (EISCONN);
1558 }
1559 sin = (struct sockaddr_in *)nam;
1560 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1561 if (error != 0) {
1562 INP_WUNLOCK(inp);
1563 INP_INFO_WUNLOCK(&V_udbinfo);
1564 return (error);
1565 }
1566 error = in_pcbconnect(inp, nam, td->td_ucred);
1567 if (error == 0)
1568 soisconnected(so);
1569 INP_WUNLOCK(inp);
1570 INP_INFO_WUNLOCK(&V_udbinfo);
1571 return (error);
1572 }
1573
1574 static void
1575 udp_detach(struct socket *so)
1576 {
1577 struct inpcb *inp;
1578 struct udpcb *up;
1579
1580 inp = sotoinpcb(so);
1581 KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1582 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1583 ("udp_detach: not disconnected"));
1584 INP_INFO_WLOCK(&V_udbinfo);
1585 INP_WLOCK(inp);
1586 up = intoudpcb(inp);
1587 KASSERT(up != NULL, ("%s: up == NULL", __func__));
1588 inp->inp_ppcb = NULL;
1589 in_pcbdetach(inp);
1590 in_pcbfree(inp);
1591 INP_INFO_WUNLOCK(&V_udbinfo);
1592 udp_discardcb(up);
1593 }
1594
1595 static int
1596 udp_disconnect(struct socket *so)
1597 {
1598 struct inpcb *inp;
1599
1600 inp = sotoinpcb(so);
1601 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1602 INP_INFO_WLOCK(&V_udbinfo);
1603 INP_WLOCK(inp);
1604 if (inp->inp_faddr.s_addr == INADDR_ANY) {
1605 INP_WUNLOCK(inp);
1606 INP_INFO_WUNLOCK(&V_udbinfo);
1607 return (ENOTCONN);
1608 }
1609
1610 in_pcbdisconnect(inp);
1611 inp->inp_laddr.s_addr = INADDR_ANY;
1612 SOCK_LOCK(so);
1613 so->so_state &= ~SS_ISCONNECTED; /* XXX */
1614 SOCK_UNLOCK(so);
1615 INP_WUNLOCK(inp);
1616 INP_INFO_WUNLOCK(&V_udbinfo);
1617 return (0);
1618 }
1619
1620 static int
1621 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1622 struct mbuf *control, struct thread *td)
1623 {
1624 struct inpcb *inp;
1625
1626 inp = sotoinpcb(so);
1627 KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1628 return (udp_output(inp, m, addr, control, td));
1629 }
1630
1631 int
1632 udp_shutdown(struct socket *so)
1633 {
1634 struct inpcb *inp;
1635
1636 inp = sotoinpcb(so);
1637 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1638 INP_WLOCK(inp);
1639 socantsendmore(so);
1640 INP_WUNLOCK(inp);
1641 return (0);
1642 }
1643
1644 struct pr_usrreqs udp_usrreqs = {
1645 .pru_abort = udp_abort,
1646 .pru_attach = udp_attach,
1647 .pru_bind = udp_bind,
1648 .pru_connect = udp_connect,
1649 .pru_control = in_control,
1650 .pru_detach = udp_detach,
1651 .pru_disconnect = udp_disconnect,
1652 .pru_peeraddr = in_getpeeraddr,
1653 .pru_send = udp_send,
1654 .pru_soreceive = soreceive_dgram,
1655 .pru_sosend = sosend_dgram,
1656 .pru_shutdown = udp_shutdown,
1657 .pru_sockaddr = in_getsockaddr,
1658 .pru_sosetlabel = in_pcbsosetlabel,
1659 .pru_close = udp_close,
1660 };
Cache object: d16fbe99eb4ab3542db2dd1e5087754d
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