84
85#ifdef IPSEC
86#include <netipsec/ipsec.h>
87#endif
88
89#include <machine/in_cksum.h>
90
91#include <security/mac/mac_framework.h>
92
93/*
94 * UDP protocol implementation.
95 * Per RFC 768, August, 1980.
96 */
97
98#ifdef VIMAGE_GLOBALS
99int udp_blackhole;
100#endif
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 */
108static int udp_cksum = 1;
109SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum,
110 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
116SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_udp, OID_AUTO, blackhole,
117 CTLFLAG_RW, udp_blackhole, 0,
118 "Do not send port unreachables for refused connects");
119
120u_long udp_sendspace = 9216; /* really max datagram size */
121 /* 40 1K datagrams */
122SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
123 &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
124
125u_long udp_recvspace = 40 * (1024 +
126#ifdef INET6
127 sizeof(struct sockaddr_in6)
128#else
129 sizeof(struct sockaddr_in)
130#endif
131 );
132
133SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
134 &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
135
136#ifdef VIMAGE_GLOBALS
137struct inpcbhead udb; /* from udp_var.h */
138struct inpcbinfo udbinfo;
139struct udpstat udpstat; /* from udp_var.h */
140#endif
141
142#ifndef UDBHASHSIZE
143#define UDBHASHSIZE 128
144#endif
145
146SYSCTL_V_STRUCT(V_NET, vnet_inet, _net_inet_udp, UDPCTL_STATS, stats,
147 CTLFLAG_RW, udpstat, udpstat,
148 "UDP statistics (struct udpstat, netinet/udp_var.h)");
149
150static void udp_detach(struct socket *so);
151static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
152 struct mbuf *, struct thread *);
153
154static void
155udp_zone_change(void *tag)
156{
157
158 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
159}
160
161static int
162udp_inpcb_init(void *mem, int size, int flags)
163{
164 struct inpcb *inp;
165
166 inp = mem;
167 INP_LOCK_INIT(inp, "inp", "udpinp");
168 return (0);
169}
170
171void
172udp_init(void)
173{
174 INIT_VNET_INET(curvnet);
175
176 V_udp_blackhole = 0;
177
178 INP_INFO_LOCK_INIT(&V_udbinfo, "udp");
179 LIST_INIT(&V_udb);
180 V_udbinfo.ipi_listhead = &V_udb;
181 V_udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
182 &V_udbinfo.ipi_hashmask);
183 V_udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
184 &V_udbinfo.ipi_porthashmask);
185 V_udbinfo.ipi_zone = uma_zcreate("udpcb", sizeof(struct inpcb), NULL,
186 NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
187 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
188 EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
189 EVENTHANDLER_PRI_ANY);
190}
191
192/*
193 * Subroutine of udp_input(), which appends the provided mbuf chain to the
194 * passed pcb/socket. The caller must provide a sockaddr_in via udp_in that
195 * contains the source address. If the socket ends up being an IPv6 socket,
196 * udp_append() will convert to a sockaddr_in6 before passing the address
197 * into the socket code.
198 */
199static void
200udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
201 struct sockaddr_in *udp_in)
202{
203 struct sockaddr *append_sa;
204 struct socket *so;
205 struct mbuf *opts = 0;
206#ifdef INET6
207 struct sockaddr_in6 udp_in6;
208#endif
209
210 INP_RLOCK_ASSERT(inp);
211
212#ifdef IPSEC
213 /* Check AH/ESP integrity. */
214 if (ipsec4_in_reject(n, inp)) {
215 INIT_VNET_IPSEC(curvnet);
216 m_freem(n);
217 V_ipsec4stat.in_polvio++;
218 return;
219 }
220#endif /* IPSEC */
221#ifdef MAC
222 if (mac_inpcb_check_deliver(inp, n) != 0) {
223 m_freem(n);
224 return;
225 }
226#endif
227 if (inp->inp_flags & INP_CONTROLOPTS ||
228 inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
229#ifdef INET6
230 if (inp->inp_vflag & INP_IPV6)
231 (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
232 else
233#endif
234 ip_savecontrol(inp, &opts, ip, n);
235 }
236#ifdef INET6
237 if (inp->inp_vflag & INP_IPV6) {
238 bzero(&udp_in6, sizeof(udp_in6));
239 udp_in6.sin6_len = sizeof(udp_in6);
240 udp_in6.sin6_family = AF_INET6;
241 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
242 append_sa = (struct sockaddr *)&udp_in6;
243 } else
244#endif
245 append_sa = (struct sockaddr *)udp_in;
246 m_adj(n, off);
247
248 so = inp->inp_socket;
249 SOCKBUF_LOCK(&so->so_rcv);
250 if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
251 INIT_VNET_INET(so->so_vnet);
252 SOCKBUF_UNLOCK(&so->so_rcv);
253 m_freem(n);
254 if (opts)
255 m_freem(opts);
256 V_udpstat.udps_fullsock++;
257 } else
258 sorwakeup_locked(so);
259}
260
261void
262udp_input(struct mbuf *m, int off)
263{
264 INIT_VNET_INET(curvnet);
265 int iphlen = off;
266 struct ip *ip;
267 struct udphdr *uh;
268 struct ifnet *ifp;
269 struct inpcb *inp;
270 int len;
271 struct ip save_ip;
272 struct sockaddr_in udp_in;
273#ifdef IPFIREWALL_FORWARD
274 struct m_tag *fwd_tag;
275#endif
276
277 ifp = m->m_pkthdr.rcvif;
278 V_udpstat.udps_ipackets++;
279
280 /*
281 * Strip IP options, if any; should skip this, make available to
282 * user, and use on returned packets, but we don't yet have a way to
283 * check the checksum with options still present.
284 */
285 if (iphlen > sizeof (struct ip)) {
286 ip_stripoptions(m, (struct mbuf *)0);
287 iphlen = sizeof(struct ip);
288 }
289
290 /*
291 * Get IP and UDP header together in first mbuf.
292 */
293 ip = mtod(m, struct ip *);
294 if (m->m_len < iphlen + sizeof(struct udphdr)) {
295 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
296 V_udpstat.udps_hdrops++;
297 return;
298 }
299 ip = mtod(m, struct ip *);
300 }
301 uh = (struct udphdr *)((caddr_t)ip + iphlen);
302
303 /*
304 * Destination port of 0 is illegal, based on RFC768.
305 */
306 if (uh->uh_dport == 0)
307 goto badunlocked;
308
309 /*
310 * Construct sockaddr format source address. Stuff source address
311 * and datagram in user buffer.
312 */
313 bzero(&udp_in, sizeof(udp_in));
314 udp_in.sin_len = sizeof(udp_in);
315 udp_in.sin_family = AF_INET;
316 udp_in.sin_port = uh->uh_sport;
317 udp_in.sin_addr = ip->ip_src;
318
319 /*
320 * Make mbuf data length reflect UDP length. If not enough data to
321 * reflect UDP length, drop.
322 */
323 len = ntohs((u_short)uh->uh_ulen);
324 if (ip->ip_len != len) {
325 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
326 V_udpstat.udps_badlen++;
327 goto badunlocked;
328 }
329 m_adj(m, len - ip->ip_len);
330 /* ip->ip_len = len; */
331 }
332
333 /*
334 * Save a copy of the IP header in case we want restore it for
335 * sending an ICMP error message in response.
336 */
337 if (!V_udp_blackhole)
338 save_ip = *ip;
339 else
340 memset(&save_ip, 0, sizeof(save_ip));
341
342 /*
343 * Checksum extended UDP header and data.
344 */
345 if (uh->uh_sum) {
346 u_short uh_sum;
347
348 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
349 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
350 uh_sum = m->m_pkthdr.csum_data;
351 else
352 uh_sum = in_pseudo(ip->ip_src.s_addr,
353 ip->ip_dst.s_addr, htonl((u_short)len +
354 m->m_pkthdr.csum_data + IPPROTO_UDP));
355 uh_sum ^= 0xffff;
356 } else {
357 char b[9];
358
359 bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
360 bzero(((struct ipovly *)ip)->ih_x1, 9);
361 ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
362 uh_sum = in_cksum(m, len + sizeof (struct ip));
363 bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
364 }
365 if (uh_sum) {
366 V_udpstat.udps_badsum++;
367 m_freem(m);
368 return;
369 }
370 } else
371 V_udpstat.udps_nosum++;
372
373#ifdef IPFIREWALL_FORWARD
374 /*
375 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
376 */
377 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
378 if (fwd_tag != NULL) {
379 struct sockaddr_in *next_hop;
380
381 /*
382 * Do the hack.
383 */
384 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
385 ip->ip_dst = next_hop->sin_addr;
386 uh->uh_dport = ntohs(next_hop->sin_port);
387
388 /*
389 * Remove the tag from the packet. We don't need it anymore.
390 */
391 m_tag_delete(m, fwd_tag);
392 }
393#endif
394
395 INP_INFO_RLOCK(&V_udbinfo);
396 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
397 in_broadcast(ip->ip_dst, ifp)) {
398 struct inpcb *last;
399 struct ip_moptions *imo;
400
401 last = NULL;
402 LIST_FOREACH(inp, &V_udb, inp_list) {
403 if (inp->inp_lport != uh->uh_dport)
404 continue;
405#ifdef INET6
406 if ((inp->inp_vflag & INP_IPV4) == 0)
407 continue;
408#endif
409 if (inp->inp_laddr.s_addr != INADDR_ANY &&
410 inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
411 continue;
412 if (inp->inp_faddr.s_addr != INADDR_ANY &&
413 inp->inp_faddr.s_addr != ip->ip_src.s_addr)
414 continue;
415 /*
416 * XXX: Do not check source port of incoming datagram
417 * unless inp_connect() has been called to bind the
418 * fport part of the 4-tuple; the source could be
419 * trying to talk to us with an ephemeral port.
420 */
421 if (inp->inp_fport != 0 &&
422 inp->inp_fport != uh->uh_sport)
423 continue;
424
425 INP_RLOCK(inp);
426
427 /*
428 * Handle socket delivery policy for any-source
429 * and source-specific multicast. [RFC3678]
430 */
431 imo = inp->inp_moptions;
432 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
433 imo != NULL) {
434 struct sockaddr_in sin;
435 struct in_msource *ims;
436 int blocked, mode;
437 size_t idx;
438
439 bzero(&sin, sizeof(struct sockaddr_in));
440 sin.sin_len = sizeof(struct sockaddr_in);
441 sin.sin_family = AF_INET;
442 sin.sin_addr = ip->ip_dst;
443
444 blocked = 0;
445 idx = imo_match_group(imo, ifp,
446 (struct sockaddr *)&sin);
447 if (idx == -1) {
448 /*
449 * No group membership for this socket.
450 * Do not bump udps_noportbcast, as
451 * this will happen further down.
452 */
453 blocked++;
454 } else {
455 /*
456 * Check for a multicast source filter
457 * entry on this socket for this group.
458 * MCAST_EXCLUDE is the default
459 * behaviour. It means default accept;
460 * entries, if present, denote sources
461 * to be excluded from delivery.
462 */
463 ims = imo_match_source(imo, idx,
464 (struct sockaddr *)&udp_in);
465 mode = imo->imo_mfilters[idx].imf_fmode;
466 if ((ims != NULL &&
467 mode == MCAST_EXCLUDE) ||
468 (ims == NULL &&
469 mode == MCAST_INCLUDE)) {
470#ifdef DIAGNOSTIC
471 if (bootverbose) {
472 printf("%s: blocked by"
473 " source filter\n",
474 __func__);
475 }
476#endif
477 V_udpstat.udps_filtermcast++;
478 blocked++;
479 }
480 }
481 if (blocked != 0) {
482 INP_RUNLOCK(inp);
483 continue;
484 }
485 }
486 if (last != NULL) {
487 struct mbuf *n;
488
489 n = m_copy(m, 0, M_COPYALL);
490 if (n != NULL)
491 udp_append(last, ip, n, iphlen +
492 sizeof(struct udphdr), &udp_in);
493 INP_RUNLOCK(last);
494 }
495 last = inp;
496 /*
497 * Don't look for additional matches if this one does
498 * not have either the SO_REUSEPORT or SO_REUSEADDR
499 * socket options set. This heuristic avoids
500 * searching through all pcbs in the common case of a
501 * non-shared port. It assumes that an application
502 * will never clear these options after setting them.
503 */
504 if ((last->inp_socket->so_options &
505 (SO_REUSEPORT|SO_REUSEADDR)) == 0)
506 break;
507 }
508
509 if (last == NULL) {
510 /*
511 * No matching pcb found; discard datagram. (No need
512 * to send an ICMP Port Unreachable for a broadcast
513 * or multicast datgram.)
514 */
515 V_udpstat.udps_noportbcast++;
516 goto badheadlocked;
517 }
518 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
519 &udp_in);
520 INP_RUNLOCK(last);
521 INP_INFO_RUNLOCK(&V_udbinfo);
522 return;
523 }
524
525 /*
526 * Locate pcb for datagram.
527 */
528 inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
529 ip->ip_dst, uh->uh_dport, 1, ifp);
530 if (inp == NULL) {
531 if (udp_log_in_vain) {
532 char buf[4*sizeof "123"];
533
534 strcpy(buf, inet_ntoa(ip->ip_dst));
535 log(LOG_INFO,
536 "Connection attempt to UDP %s:%d from %s:%d\n",
537 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
538 ntohs(uh->uh_sport));
539 }
540 V_udpstat.udps_noport++;
541 if (m->m_flags & (M_BCAST | M_MCAST)) {
542 V_udpstat.udps_noportbcast++;
543 goto badheadlocked;
544 }
545 if (V_udp_blackhole)
546 goto badheadlocked;
547 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
548 goto badheadlocked;
549 *ip = save_ip;
550 ip->ip_len += iphlen;
551 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
552 INP_INFO_RUNLOCK(&V_udbinfo);
553 return;
554 }
555
556 /*
557 * Check the minimum TTL for socket.
558 */
559 INP_RLOCK(inp);
560 INP_INFO_RUNLOCK(&V_udbinfo);
561 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
562 INP_RUNLOCK(inp);
563 goto badunlocked;
564 }
565 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
566 INP_RUNLOCK(inp);
567 return;
568
569badheadlocked:
570 if (inp)
571 INP_RUNLOCK(inp);
572 INP_INFO_RUNLOCK(&V_udbinfo);
573badunlocked:
574 m_freem(m);
575}
576
577/*
578 * Notify a udp user of an asynchronous error; just wake up so that they can
579 * collect error status.
580 */
581struct inpcb *
582udp_notify(struct inpcb *inp, int errno)
583{
584
585 /*
586 * While udp_ctlinput() always calls udp_notify() with a read lock
587 * when invoking it directly, in_pcbnotifyall() currently uses write
588 * locks due to sharing code with TCP. For now, accept either a read
589 * or a write lock, but a read lock is sufficient.
590 */
591 INP_LOCK_ASSERT(inp);
592
593 inp->inp_socket->so_error = errno;
594 sorwakeup(inp->inp_socket);
595 sowwakeup(inp->inp_socket);
596 return (inp);
597}
598
599void
600udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
601{
602 INIT_VNET_INET(curvnet);
603 struct ip *ip = vip;
604 struct udphdr *uh;
605 struct in_addr faddr;
606 struct inpcb *inp;
607
608 faddr = ((struct sockaddr_in *)sa)->sin_addr;
609 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
610 return;
611
612 /*
613 * Redirects don't need to be handled up here.
614 */
615 if (PRC_IS_REDIRECT(cmd))
616 return;
617
618 /*
619 * Hostdead is ugly because it goes linearly through all PCBs.
620 *
621 * XXX: We never get this from ICMP, otherwise it makes an excellent
622 * DoS attack on machines with many connections.
623 */
624 if (cmd == PRC_HOSTDEAD)
625 ip = NULL;
626 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
627 return;
628 if (ip != NULL) {
629 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
630 INP_INFO_RLOCK(&V_udbinfo);
631 inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
632 ip->ip_src, uh->uh_sport, 0, NULL);
633 if (inp != NULL) {
634 INP_RLOCK(inp);
635 if (inp->inp_socket != NULL) {
636 udp_notify(inp, inetctlerrmap[cmd]);
637 }
638 INP_RUNLOCK(inp);
639 }
640 INP_INFO_RUNLOCK(&V_udbinfo);
641 } else
642 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
643 udp_notify);
644}
645
646static int
647udp_pcblist(SYSCTL_HANDLER_ARGS)
648{
649 INIT_VNET_INET(curvnet);
650 int error, i, n;
651 struct inpcb *inp, **inp_list;
652 inp_gen_t gencnt;
653 struct xinpgen xig;
654
655 /*
656 * The process of preparing the PCB list is too time-consuming and
657 * resource-intensive to repeat twice on every request.
658 */
659 if (req->oldptr == 0) {
660 n = V_udbinfo.ipi_count;
661 req->oldidx = 2 * (sizeof xig)
662 + (n + n/8) * sizeof(struct xinpcb);
663 return (0);
664 }
665
666 if (req->newptr != 0)
667 return (EPERM);
668
669 /*
670 * OK, now we're committed to doing something.
671 */
672 INP_INFO_RLOCK(&V_udbinfo);
673 gencnt = V_udbinfo.ipi_gencnt;
674 n = V_udbinfo.ipi_count;
675 INP_INFO_RUNLOCK(&V_udbinfo);
676
677 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
678 + n * sizeof(struct xinpcb));
679 if (error != 0)
680 return (error);
681
682 xig.xig_len = sizeof xig;
683 xig.xig_count = n;
684 xig.xig_gen = gencnt;
685 xig.xig_sogen = so_gencnt;
686 error = SYSCTL_OUT(req, &xig, sizeof xig);
687 if (error)
688 return (error);
689
690 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
691 if (inp_list == 0)
692 return (ENOMEM);
693
694 INP_INFO_RLOCK(&V_udbinfo);
695 for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
696 inp = LIST_NEXT(inp, inp_list)) {
697 INP_RLOCK(inp);
698 if (inp->inp_gencnt <= gencnt &&
699 cr_canseeinpcb(req->td->td_ucred, inp) == 0)
700 inp_list[i++] = inp;
701 INP_RUNLOCK(inp);
702 }
703 INP_INFO_RUNLOCK(&V_udbinfo);
704 n = i;
705
706 error = 0;
707 for (i = 0; i < n; i++) {
708 inp = inp_list[i];
709 INP_RLOCK(inp);
710 if (inp->inp_gencnt <= gencnt) {
711 struct xinpcb xi;
712 bzero(&xi, sizeof(xi));
713 xi.xi_len = sizeof xi;
714 /* XXX should avoid extra copy */
715 bcopy(inp, &xi.xi_inp, sizeof *inp);
716 if (inp->inp_socket)
717 sotoxsocket(inp->inp_socket, &xi.xi_socket);
718 xi.xi_inp.inp_gencnt = inp->inp_gencnt;
719 INP_RUNLOCK(inp);
720 error = SYSCTL_OUT(req, &xi, sizeof xi);
721 } else
722 INP_RUNLOCK(inp);
723 }
724 if (!error) {
725 /*
726 * Give the user an updated idea of our state. If the
727 * generation differs from what we told her before, she knows
728 * that something happened while we were processing this
729 * request, and it might be necessary to retry.
730 */
731 INP_INFO_RLOCK(&V_udbinfo);
732 xig.xig_gen = V_udbinfo.ipi_gencnt;
733 xig.xig_sogen = so_gencnt;
734 xig.xig_count = V_udbinfo.ipi_count;
735 INP_INFO_RUNLOCK(&V_udbinfo);
736 error = SYSCTL_OUT(req, &xig, sizeof xig);
737 }
738 free(inp_list, M_TEMP);
739 return (error);
740}
741
742SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
743 udp_pcblist, "S,xinpcb", "List of active UDP sockets");
744
745static int
746udp_getcred(SYSCTL_HANDLER_ARGS)
747{
748 INIT_VNET_INET(curvnet);
749 struct xucred xuc;
750 struct sockaddr_in addrs[2];
751 struct inpcb *inp;
752 int error;
753
754 error = priv_check(req->td, PRIV_NETINET_GETCRED);
755 if (error)
756 return (error);
757 error = SYSCTL_IN(req, addrs, sizeof(addrs));
758 if (error)
759 return (error);
760 INP_INFO_RLOCK(&V_udbinfo);
761 inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
762 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
763 if (inp != NULL) {
764 INP_RLOCK(inp);
765 INP_INFO_RUNLOCK(&V_udbinfo);
766 if (inp->inp_socket == NULL)
767 error = ENOENT;
768 if (error == 0)
769 error = cr_canseeinpcb(req->td->td_ucred, inp);
770 if (error == 0)
771 cru2x(inp->inp_cred, &xuc);
772 INP_RUNLOCK(inp);
773 } else {
774 INP_INFO_RUNLOCK(&V_udbinfo);
775 error = ENOENT;
776 }
777 if (error == 0)
778 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
779 return (error);
780}
781
782SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
783 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
784 udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
785
786static int
787udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
788 struct mbuf *control, struct thread *td)
789{
790 INIT_VNET_INET(inp->inp_vnet);
791 struct udpiphdr *ui;
792 int len = m->m_pkthdr.len;
793 struct in_addr faddr, laddr;
794 struct cmsghdr *cm;
795 struct sockaddr_in *sin, src;
796 int error = 0;
797 int ipflags;
798 u_short fport, lport;
799 int unlock_udbinfo;
800
801 /*
802 * udp_output() may need to temporarily bind or connect the current
803 * inpcb. As such, we don't know up front whether we will need the
804 * pcbinfo lock or not. Do any work to decide what is needed up
805 * front before acquiring any locks.
806 */
807 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
808 if (control)
809 m_freem(control);
810 m_freem(m);
811 return (EMSGSIZE);
812 }
813
814 src.sin_family = 0;
815 if (control != NULL) {
816 /*
817 * XXX: Currently, we assume all the optional information is
818 * stored in a single mbuf.
819 */
820 if (control->m_next) {
821 m_freem(control);
822 m_freem(m);
823 return (EINVAL);
824 }
825 for (; control->m_len > 0;
826 control->m_data += CMSG_ALIGN(cm->cmsg_len),
827 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
828 cm = mtod(control, struct cmsghdr *);
829 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
830 || cm->cmsg_len > control->m_len) {
831 error = EINVAL;
832 break;
833 }
834 if (cm->cmsg_level != IPPROTO_IP)
835 continue;
836
837 switch (cm->cmsg_type) {
838 case IP_SENDSRCADDR:
839 if (cm->cmsg_len !=
840 CMSG_LEN(sizeof(struct in_addr))) {
841 error = EINVAL;
842 break;
843 }
844 bzero(&src, sizeof(src));
845 src.sin_family = AF_INET;
846 src.sin_len = sizeof(src);
847 src.sin_port = inp->inp_lport;
848 src.sin_addr =
849 *(struct in_addr *)CMSG_DATA(cm);
850 break;
851
852 default:
853 error = ENOPROTOOPT;
854 break;
855 }
856 if (error)
857 break;
858 }
859 m_freem(control);
860 }
861 if (error) {
862 m_freem(m);
863 return (error);
864 }
865
866 /*
867 * Depending on whether or not the application has bound or connected
868 * the socket, we may have to do varying levels of work. The optimal
869 * case is for a connected UDP socket, as a global lock isn't
870 * required at all.
871 *
872 * In order to decide which we need, we require stability of the
873 * inpcb binding, which we ensure by acquiring a read lock on the
874 * inpcb. This doesn't strictly follow the lock order, so we play
875 * the trylock and retry game; note that we may end up with more
876 * conservative locks than required the second time around, so later
877 * assertions have to accept that. Further analysis of the number of
878 * misses under contention is required.
879 */
880 sin = (struct sockaddr_in *)addr;
881 INP_RLOCK(inp);
882 if (sin != NULL &&
883 (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
884 INP_RUNLOCK(inp);
885 INP_INFO_WLOCK(&V_udbinfo);
886 INP_WLOCK(inp);
887 unlock_udbinfo = 2;
888 } else if ((sin != NULL && (
889 (sin->sin_addr.s_addr == INADDR_ANY) ||
890 (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
891 (inp->inp_laddr.s_addr == INADDR_ANY) ||
892 (inp->inp_lport == 0))) ||
893 (src.sin_family == AF_INET)) {
894 if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
895 INP_RUNLOCK(inp);
896 INP_INFO_RLOCK(&V_udbinfo);
897 INP_RLOCK(inp);
898 }
899 unlock_udbinfo = 1;
900 } else
901 unlock_udbinfo = 0;
902
903 /*
904 * If the IP_SENDSRCADDR control message was specified, override the
905 * source address for this datagram. Its use is invalidated if the
906 * address thus specified is incomplete or clobbers other inpcbs.
907 */
908 laddr = inp->inp_laddr;
909 lport = inp->inp_lport;
910 if (src.sin_family == AF_INET) {
911 INP_INFO_LOCK_ASSERT(&V_udbinfo);
912 if ((lport == 0) ||
913 (laddr.s_addr == INADDR_ANY &&
914 src.sin_addr.s_addr == INADDR_ANY)) {
915 error = EINVAL;
916 goto release;
917 }
918 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
919 &laddr.s_addr, &lport, td->td_ucred);
920 if (error)
921 goto release;
922 }
923
924 /*
925 * If a UDP socket has been connected, then a local address/port will
926 * have been selected and bound.
927 *
928 * If a UDP socket has not been connected to, then an explicit
929 * destination address must be used, in which case a local
930 * address/port may not have been selected and bound.
931 */
932 if (sin != NULL) {
933 INP_LOCK_ASSERT(inp);
934 if (inp->inp_faddr.s_addr != INADDR_ANY) {
935 error = EISCONN;
936 goto release;
937 }
938
939 /*
940 * Jail may rewrite the destination address, so let it do
941 * that before we use it.
942 */
943 if (prison_remote_ip4(td->td_ucred, &sin->sin_addr) != 0) {
944 error = EINVAL;
945 goto release;
946 }
947
948 /*
949 * If a local address or port hasn't yet been selected, or if
950 * the destination address needs to be rewritten due to using
951 * a special INADDR_ constant, invoke in_pcbconnect_setup()
952 * to do the heavy lifting. Once a port is selected, we
953 * commit the binding back to the socket; we also commit the
954 * binding of the address if in jail.
955 *
956 * If we already have a valid binding and we're not
957 * requesting a destination address rewrite, use a fast path.
958 */
959 if (inp->inp_laddr.s_addr == INADDR_ANY ||
960 inp->inp_lport == 0 ||
961 sin->sin_addr.s_addr == INADDR_ANY ||
962 sin->sin_addr.s_addr == INADDR_BROADCAST) {
963 INP_INFO_LOCK_ASSERT(&V_udbinfo);
964 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
965 &lport, &faddr.s_addr, &fport, NULL,
966 td->td_ucred);
967 if (error)
968 goto release;
969
970 /*
971 * XXXRW: Why not commit the port if the address is
972 * !INADDR_ANY?
973 */
974 /* Commit the local port if newly assigned. */
975 if (inp->inp_laddr.s_addr == INADDR_ANY &&
976 inp->inp_lport == 0) {
977 INP_INFO_WLOCK_ASSERT(&V_udbinfo);
978 INP_WLOCK_ASSERT(inp);
979 /*
980 * Remember addr if jailed, to prevent
981 * rebinding.
982 */
983 if (jailed(td->td_ucred))
984 inp->inp_laddr = laddr;
985 inp->inp_lport = lport;
986 if (in_pcbinshash(inp) != 0) {
987 inp->inp_lport = 0;
988 error = EAGAIN;
989 goto release;
990 }
991 inp->inp_flags |= INP_ANONPORT;
992 }
993 } else {
994 faddr = sin->sin_addr;
995 fport = sin->sin_port;
996 }
997 } else {
998 INP_LOCK_ASSERT(inp);
999 faddr = inp->inp_faddr;
1000 fport = inp->inp_fport;
1001 if (faddr.s_addr == INADDR_ANY) {
1002 error = ENOTCONN;
1003 goto release;
1004 }
1005 }
1006
1007 /*
1008 * Calculate data length and get a mbuf for UDP, IP, and possible
1009 * link-layer headers. Immediate slide the data pointer back forward
1010 * since we won't use that space at this layer.
1011 */
1012 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1013 if (m == NULL) {
1014 error = ENOBUFS;
1015 goto release;
1016 }
1017 m->m_data += max_linkhdr;
1018 m->m_len -= max_linkhdr;
1019 m->m_pkthdr.len -= max_linkhdr;
1020
1021 /*
1022 * Fill in mbuf with extended UDP header and addresses and length put
1023 * into network format.
1024 */
1025 ui = mtod(m, struct udpiphdr *);
1026 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */
1027 ui->ui_pr = IPPROTO_UDP;
1028 ui->ui_src = laddr;
1029 ui->ui_dst = faddr;
1030 ui->ui_sport = lport;
1031 ui->ui_dport = fport;
1032 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1033
1034 /*
1035 * Set the Don't Fragment bit in the IP header.
1036 */
1037 if (inp->inp_flags & INP_DONTFRAG) {
1038 struct ip *ip;
1039
1040 ip = (struct ip *)&ui->ui_i;
1041 ip->ip_off |= IP_DF;
1042 }
1043
1044 ipflags = 0;
1045 if (inp->inp_socket->so_options & SO_DONTROUTE)
1046 ipflags |= IP_ROUTETOIF;
1047 if (inp->inp_socket->so_options & SO_BROADCAST)
1048 ipflags |= IP_ALLOWBROADCAST;
1049 if (inp->inp_flags & INP_ONESBCAST)
1050 ipflags |= IP_SENDONES;
1051
1052#ifdef MAC
1053 mac_inpcb_create_mbuf(inp, m);
1054#endif
1055
1056 /*
1057 * Set up checksum and output datagram.
1058 */
1059 if (udp_cksum) {
1060 if (inp->inp_flags & INP_ONESBCAST)
1061 faddr.s_addr = INADDR_BROADCAST;
1062 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1063 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1064 m->m_pkthdr.csum_flags = CSUM_UDP;
1065 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1066 } else
1067 ui->ui_sum = 0;
1068 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1069 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
1070 ((struct ip *)ui)->ip_tos = inp->inp_ip_tos; /* XXX */
1071 V_udpstat.udps_opackets++;
1072
1073 if (unlock_udbinfo == 2)
1074 INP_INFO_WUNLOCK(&V_udbinfo);
1075 else if (unlock_udbinfo == 1)
1076 INP_INFO_RUNLOCK(&V_udbinfo);
1077 error = ip_output(m, inp->inp_options, NULL, ipflags,
1078 inp->inp_moptions, inp);
1079 if (unlock_udbinfo == 2)
1080 INP_WUNLOCK(inp);
1081 else
1082 INP_RUNLOCK(inp);
1083 return (error);
1084
1085release:
1086 if (unlock_udbinfo == 2) {
1087 INP_WUNLOCK(inp);
1088 INP_INFO_WUNLOCK(&V_udbinfo);
1089 } else if (unlock_udbinfo == 1) {
1090 INP_RUNLOCK(inp);
1091 INP_INFO_RUNLOCK(&V_udbinfo);
1092 } else
1093 INP_RUNLOCK(inp);
1094 m_freem(m);
1095 return (error);
1096}
1097
1098static void
1099udp_abort(struct socket *so)
1100{
1101 INIT_VNET_INET(so->so_vnet);
1102 struct inpcb *inp;
1103
1104 inp = sotoinpcb(so);
1105 KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1106 INP_INFO_WLOCK(&V_udbinfo);
1107 INP_WLOCK(inp);
1108 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1109 in_pcbdisconnect(inp);
1110 inp->inp_laddr.s_addr = INADDR_ANY;
1111 soisdisconnected(so);
1112 }
1113 INP_WUNLOCK(inp);
1114 INP_INFO_WUNLOCK(&V_udbinfo);
1115}
1116
1117static int
1118udp_attach(struct socket *so, int proto, struct thread *td)
1119{
1120 INIT_VNET_INET(so->so_vnet);
1121 struct inpcb *inp;
1122 int error;
1123
1124 inp = sotoinpcb(so);
1125 KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1126 error = soreserve(so, udp_sendspace, udp_recvspace);
1127 if (error)
1128 return (error);
1129 INP_INFO_WLOCK(&V_udbinfo);
1130 error = in_pcballoc(so, &V_udbinfo);
1131 if (error) {
1132 INP_INFO_WUNLOCK(&V_udbinfo);
1133 return (error);
1134 }
1135
1136 inp = (struct inpcb *)so->so_pcb;
1137 INP_INFO_WUNLOCK(&V_udbinfo);
1138 inp->inp_vflag |= INP_IPV4;
1139 inp->inp_ip_ttl = V_ip_defttl;
1140 INP_WUNLOCK(inp);
1141 return (0);
1142}
1143
1144static int
1145udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1146{
1147 INIT_VNET_INET(so->so_vnet);
1148 struct inpcb *inp;
1149 int error;
1150
1151 inp = sotoinpcb(so);
1152 KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1153 INP_INFO_WLOCK(&V_udbinfo);
1154 INP_WLOCK(inp);
1155 error = in_pcbbind(inp, nam, td->td_ucred);
1156 INP_WUNLOCK(inp);
1157 INP_INFO_WUNLOCK(&V_udbinfo);
1158 return (error);
1159}
1160
1161static void
1162udp_close(struct socket *so)
1163{
1164 INIT_VNET_INET(so->so_vnet);
1165 struct inpcb *inp;
1166
1167 inp = sotoinpcb(so);
1168 KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1169 INP_INFO_WLOCK(&V_udbinfo);
1170 INP_WLOCK(inp);
1171 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1172 in_pcbdisconnect(inp);
1173 inp->inp_laddr.s_addr = INADDR_ANY;
1174 soisdisconnected(so);
1175 }
1176 INP_WUNLOCK(inp);
1177 INP_INFO_WUNLOCK(&V_udbinfo);
1178}
1179
1180static int
1181udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1182{
1183 INIT_VNET_INET(so->so_vnet);
1184 struct inpcb *inp;
1185 int error;
1186 struct sockaddr_in *sin;
1187
1188 inp = sotoinpcb(so);
1189 KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1190 INP_INFO_WLOCK(&V_udbinfo);
1191 INP_WLOCK(inp);
1192 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1193 INP_WUNLOCK(inp);
1194 INP_INFO_WUNLOCK(&V_udbinfo);
1195 return (EISCONN);
1196 }
1197 sin = (struct sockaddr_in *)nam;
1198 if (prison_remote_ip4(td->td_ucred, &sin->sin_addr) != 0) {
1199 INP_WUNLOCK(inp);
1200 INP_INFO_WUNLOCK(&udbinfo);
1201 return (EAFNOSUPPORT);
1202 }
1203 error = in_pcbconnect(inp, nam, td->td_ucred);
1204 if (error == 0)
1205 soisconnected(so);
1206 INP_WUNLOCK(inp);
1207 INP_INFO_WUNLOCK(&V_udbinfo);
1208 return (error);
1209}
1210
1211static void
1212udp_detach(struct socket *so)
1213{
1214 INIT_VNET_INET(so->so_vnet);
1215 struct inpcb *inp;
1216
1217 inp = sotoinpcb(so);
1218 KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1219 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1220 ("udp_detach: not disconnected"));
1221 INP_INFO_WLOCK(&V_udbinfo);
1222 INP_WLOCK(inp);
1223 in_pcbdetach(inp);
1224 in_pcbfree(inp);
1225 INP_INFO_WUNLOCK(&V_udbinfo);
1226}
1227
1228static int
1229udp_disconnect(struct socket *so)
1230{
1231 INIT_VNET_INET(so->so_vnet);
1232 struct inpcb *inp;
1233
1234 inp = sotoinpcb(so);
1235 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1236 INP_INFO_WLOCK(&V_udbinfo);
1237 INP_WLOCK(inp);
1238 if (inp->inp_faddr.s_addr == INADDR_ANY) {
1239 INP_WUNLOCK(inp);
1240 INP_INFO_WUNLOCK(&V_udbinfo);
1241 return (ENOTCONN);
1242 }
1243
1244 in_pcbdisconnect(inp);
1245 inp->inp_laddr.s_addr = INADDR_ANY;
1246 SOCK_LOCK(so);
1247 so->so_state &= ~SS_ISCONNECTED; /* XXX */
1248 SOCK_UNLOCK(so);
1249 INP_WUNLOCK(inp);
1250 INP_INFO_WUNLOCK(&V_udbinfo);
1251 return (0);
1252}
1253
1254static int
1255udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1256 struct mbuf *control, struct thread *td)
1257{
1258 struct inpcb *inp;
1259
1260 inp = sotoinpcb(so);
1261 KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1262 return (udp_output(inp, m, addr, control, td));
1263}
1264
1265int
1266udp_shutdown(struct socket *so)
1267{
1268 struct inpcb *inp;
1269
1270 inp = sotoinpcb(so);
1271 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1272 INP_WLOCK(inp);
1273 socantsendmore(so);
1274 INP_WUNLOCK(inp);
1275 return (0);
1276}
1277
1278struct pr_usrreqs udp_usrreqs = {
1279 .pru_abort = udp_abort,
1280 .pru_attach = udp_attach,
1281 .pru_bind = udp_bind,
1282 .pru_connect = udp_connect,
1283 .pru_control = in_control,
1284 .pru_detach = udp_detach,
1285 .pru_disconnect = udp_disconnect,
1286 .pru_peeraddr = in_getpeeraddr,
1287 .pru_send = udp_send,
1288 .pru_soreceive = soreceive_dgram,
1289 .pru_sosend = sosend_dgram,
1290 .pru_shutdown = udp_shutdown,
1291 .pru_sockaddr = in_getsockaddr,
1292 .pru_sosetlabel = in_pcbsosetlabel,
1293 .pru_close = udp_close,
1294};
| 85
86#ifdef IPSEC
87#include <netipsec/ipsec.h>
88#endif
89
90#include <machine/in_cksum.h>
91
92#include <security/mac/mac_framework.h>
93
94/*
95 * UDP protocol implementation.
96 * Per RFC 768, August, 1980.
97 */
98
99#ifdef VIMAGE_GLOBALS
100int udp_blackhole;
101#endif
102
103/*
104 * BSD 4.2 defaulted the udp checksum to be off. Turning off udp checksums
105 * removes the only data integrity mechanism for packets and malformed
106 * packets that would otherwise be discarded due to bad checksums, and may
107 * cause problems (especially for NFS data blocks).
108 */
109static int udp_cksum = 1;
110SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum,
111 0, "compute udp checksum");
112
113int udp_log_in_vain = 0;
114SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
115 &udp_log_in_vain, 0, "Log all incoming UDP packets");
116
117SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_udp, OID_AUTO, blackhole,
118 CTLFLAG_RW, 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
137#ifdef VIMAGE_GLOBALS
138struct inpcbhead udb; /* from udp_var.h */
139struct inpcbinfo udbinfo;
140struct udpstat udpstat; /* from udp_var.h */
141#endif
142
143#ifndef UDBHASHSIZE
144#define UDBHASHSIZE 128
145#endif
146
147SYSCTL_V_STRUCT(V_NET, vnet_inet, _net_inet_udp, UDPCTL_STATS, stats,
148 CTLFLAG_RW, udpstat, udpstat,
149 "UDP statistics (struct udpstat, netinet/udp_var.h)");
150
151static void udp_detach(struct socket *so);
152static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
153 struct mbuf *, struct thread *);
154
155static void
156udp_zone_change(void *tag)
157{
158
159 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
160}
161
162static int
163udp_inpcb_init(void *mem, int size, int flags)
164{
165 struct inpcb *inp;
166
167 inp = mem;
168 INP_LOCK_INIT(inp, "inp", "udpinp");
169 return (0);
170}
171
172void
173udp_init(void)
174{
175 INIT_VNET_INET(curvnet);
176
177 V_udp_blackhole = 0;
178
179 INP_INFO_LOCK_INIT(&V_udbinfo, "udp");
180 LIST_INIT(&V_udb);
181 V_udbinfo.ipi_listhead = &V_udb;
182 V_udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
183 &V_udbinfo.ipi_hashmask);
184 V_udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
185 &V_udbinfo.ipi_porthashmask);
186 V_udbinfo.ipi_zone = uma_zcreate("udpcb", sizeof(struct inpcb), NULL,
187 NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
188 uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
189 EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
190 EVENTHANDLER_PRI_ANY);
191}
192
193/*
194 * Subroutine of udp_input(), which appends the provided mbuf chain to the
195 * passed pcb/socket. The caller must provide a sockaddr_in via udp_in that
196 * contains the source address. If the socket ends up being an IPv6 socket,
197 * udp_append() will convert to a sockaddr_in6 before passing the address
198 * into the socket code.
199 */
200static void
201udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
202 struct sockaddr_in *udp_in)
203{
204 struct sockaddr *append_sa;
205 struct socket *so;
206 struct mbuf *opts = 0;
207#ifdef INET6
208 struct sockaddr_in6 udp_in6;
209#endif
210
211 INP_RLOCK_ASSERT(inp);
212
213#ifdef IPSEC
214 /* Check AH/ESP integrity. */
215 if (ipsec4_in_reject(n, inp)) {
216 INIT_VNET_IPSEC(curvnet);
217 m_freem(n);
218 V_ipsec4stat.in_polvio++;
219 return;
220 }
221#endif /* IPSEC */
222#ifdef MAC
223 if (mac_inpcb_check_deliver(inp, n) != 0) {
224 m_freem(n);
225 return;
226 }
227#endif
228 if (inp->inp_flags & INP_CONTROLOPTS ||
229 inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
230#ifdef INET6
231 if (inp->inp_vflag & INP_IPV6)
232 (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
233 else
234#endif
235 ip_savecontrol(inp, &opts, ip, n);
236 }
237#ifdef INET6
238 if (inp->inp_vflag & INP_IPV6) {
239 bzero(&udp_in6, sizeof(udp_in6));
240 udp_in6.sin6_len = sizeof(udp_in6);
241 udp_in6.sin6_family = AF_INET6;
242 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
243 append_sa = (struct sockaddr *)&udp_in6;
244 } else
245#endif
246 append_sa = (struct sockaddr *)udp_in;
247 m_adj(n, off);
248
249 so = inp->inp_socket;
250 SOCKBUF_LOCK(&so->so_rcv);
251 if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
252 INIT_VNET_INET(so->so_vnet);
253 SOCKBUF_UNLOCK(&so->so_rcv);
254 m_freem(n);
255 if (opts)
256 m_freem(opts);
257 V_udpstat.udps_fullsock++;
258 } else
259 sorwakeup_locked(so);
260}
261
262void
263udp_input(struct mbuf *m, int off)
264{
265 INIT_VNET_INET(curvnet);
266 int iphlen = off;
267 struct ip *ip;
268 struct udphdr *uh;
269 struct ifnet *ifp;
270 struct inpcb *inp;
271 int len;
272 struct ip save_ip;
273 struct sockaddr_in udp_in;
274#ifdef IPFIREWALL_FORWARD
275 struct m_tag *fwd_tag;
276#endif
277
278 ifp = m->m_pkthdr.rcvif;
279 V_udpstat.udps_ipackets++;
280
281 /*
282 * Strip IP options, if any; should skip this, make available to
283 * user, and use on returned packets, but we don't yet have a way to
284 * check the checksum with options still present.
285 */
286 if (iphlen > sizeof (struct ip)) {
287 ip_stripoptions(m, (struct mbuf *)0);
288 iphlen = sizeof(struct ip);
289 }
290
291 /*
292 * Get IP and UDP header together in first mbuf.
293 */
294 ip = mtod(m, struct ip *);
295 if (m->m_len < iphlen + sizeof(struct udphdr)) {
296 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
297 V_udpstat.udps_hdrops++;
298 return;
299 }
300 ip = mtod(m, struct ip *);
301 }
302 uh = (struct udphdr *)((caddr_t)ip + iphlen);
303
304 /*
305 * Destination port of 0 is illegal, based on RFC768.
306 */
307 if (uh->uh_dport == 0)
308 goto badunlocked;
309
310 /*
311 * Construct sockaddr format source address. Stuff source address
312 * and datagram in user buffer.
313 */
314 bzero(&udp_in, sizeof(udp_in));
315 udp_in.sin_len = sizeof(udp_in);
316 udp_in.sin_family = AF_INET;
317 udp_in.sin_port = uh->uh_sport;
318 udp_in.sin_addr = ip->ip_src;
319
320 /*
321 * Make mbuf data length reflect UDP length. If not enough data to
322 * reflect UDP length, drop.
323 */
324 len = ntohs((u_short)uh->uh_ulen);
325 if (ip->ip_len != len) {
326 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
327 V_udpstat.udps_badlen++;
328 goto badunlocked;
329 }
330 m_adj(m, len - ip->ip_len);
331 /* ip->ip_len = len; */
332 }
333
334 /*
335 * Save a copy of the IP header in case we want restore it for
336 * sending an ICMP error message in response.
337 */
338 if (!V_udp_blackhole)
339 save_ip = *ip;
340 else
341 memset(&save_ip, 0, sizeof(save_ip));
342
343 /*
344 * Checksum extended UDP header and data.
345 */
346 if (uh->uh_sum) {
347 u_short uh_sum;
348
349 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
350 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
351 uh_sum = m->m_pkthdr.csum_data;
352 else
353 uh_sum = in_pseudo(ip->ip_src.s_addr,
354 ip->ip_dst.s_addr, htonl((u_short)len +
355 m->m_pkthdr.csum_data + IPPROTO_UDP));
356 uh_sum ^= 0xffff;
357 } else {
358 char b[9];
359
360 bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
361 bzero(((struct ipovly *)ip)->ih_x1, 9);
362 ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
363 uh_sum = in_cksum(m, len + sizeof (struct ip));
364 bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
365 }
366 if (uh_sum) {
367 V_udpstat.udps_badsum++;
368 m_freem(m);
369 return;
370 }
371 } else
372 V_udpstat.udps_nosum++;
373
374#ifdef IPFIREWALL_FORWARD
375 /*
376 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
377 */
378 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
379 if (fwd_tag != NULL) {
380 struct sockaddr_in *next_hop;
381
382 /*
383 * Do the hack.
384 */
385 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
386 ip->ip_dst = next_hop->sin_addr;
387 uh->uh_dport = ntohs(next_hop->sin_port);
388
389 /*
390 * Remove the tag from the packet. We don't need it anymore.
391 */
392 m_tag_delete(m, fwd_tag);
393 }
394#endif
395
396 INP_INFO_RLOCK(&V_udbinfo);
397 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
398 in_broadcast(ip->ip_dst, ifp)) {
399 struct inpcb *last;
400 struct ip_moptions *imo;
401
402 last = NULL;
403 LIST_FOREACH(inp, &V_udb, inp_list) {
404 if (inp->inp_lport != uh->uh_dport)
405 continue;
406#ifdef INET6
407 if ((inp->inp_vflag & INP_IPV4) == 0)
408 continue;
409#endif
410 if (inp->inp_laddr.s_addr != INADDR_ANY &&
411 inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
412 continue;
413 if (inp->inp_faddr.s_addr != INADDR_ANY &&
414 inp->inp_faddr.s_addr != ip->ip_src.s_addr)
415 continue;
416 /*
417 * XXX: Do not check source port of incoming datagram
418 * unless inp_connect() has been called to bind the
419 * fport part of the 4-tuple; the source could be
420 * trying to talk to us with an ephemeral port.
421 */
422 if (inp->inp_fport != 0 &&
423 inp->inp_fport != uh->uh_sport)
424 continue;
425
426 INP_RLOCK(inp);
427
428 /*
429 * Handle socket delivery policy for any-source
430 * and source-specific multicast. [RFC3678]
431 */
432 imo = inp->inp_moptions;
433 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
434 imo != NULL) {
435 struct sockaddr_in sin;
436 struct in_msource *ims;
437 int blocked, mode;
438 size_t idx;
439
440 bzero(&sin, sizeof(struct sockaddr_in));
441 sin.sin_len = sizeof(struct sockaddr_in);
442 sin.sin_family = AF_INET;
443 sin.sin_addr = ip->ip_dst;
444
445 blocked = 0;
446 idx = imo_match_group(imo, ifp,
447 (struct sockaddr *)&sin);
448 if (idx == -1) {
449 /*
450 * No group membership for this socket.
451 * Do not bump udps_noportbcast, as
452 * this will happen further down.
453 */
454 blocked++;
455 } else {
456 /*
457 * Check for a multicast source filter
458 * entry on this socket for this group.
459 * MCAST_EXCLUDE is the default
460 * behaviour. It means default accept;
461 * entries, if present, denote sources
462 * to be excluded from delivery.
463 */
464 ims = imo_match_source(imo, idx,
465 (struct sockaddr *)&udp_in);
466 mode = imo->imo_mfilters[idx].imf_fmode;
467 if ((ims != NULL &&
468 mode == MCAST_EXCLUDE) ||
469 (ims == NULL &&
470 mode == MCAST_INCLUDE)) {
471#ifdef DIAGNOSTIC
472 if (bootverbose) {
473 printf("%s: blocked by"
474 " source filter\n",
475 __func__);
476 }
477#endif
478 V_udpstat.udps_filtermcast++;
479 blocked++;
480 }
481 }
482 if (blocked != 0) {
483 INP_RUNLOCK(inp);
484 continue;
485 }
486 }
487 if (last != NULL) {
488 struct mbuf *n;
489
490 n = m_copy(m, 0, M_COPYALL);
491 if (n != NULL)
492 udp_append(last, ip, n, iphlen +
493 sizeof(struct udphdr), &udp_in);
494 INP_RUNLOCK(last);
495 }
496 last = inp;
497 /*
498 * Don't look for additional matches if this one does
499 * not have either the SO_REUSEPORT or SO_REUSEADDR
500 * socket options set. This heuristic avoids
501 * searching through all pcbs in the common case of a
502 * non-shared port. It assumes that an application
503 * will never clear these options after setting them.
504 */
505 if ((last->inp_socket->so_options &
506 (SO_REUSEPORT|SO_REUSEADDR)) == 0)
507 break;
508 }
509
510 if (last == NULL) {
511 /*
512 * No matching pcb found; discard datagram. (No need
513 * to send an ICMP Port Unreachable for a broadcast
514 * or multicast datgram.)
515 */
516 V_udpstat.udps_noportbcast++;
517 goto badheadlocked;
518 }
519 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
520 &udp_in);
521 INP_RUNLOCK(last);
522 INP_INFO_RUNLOCK(&V_udbinfo);
523 return;
524 }
525
526 /*
527 * Locate pcb for datagram.
528 */
529 inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
530 ip->ip_dst, uh->uh_dport, 1, ifp);
531 if (inp == NULL) {
532 if (udp_log_in_vain) {
533 char buf[4*sizeof "123"];
534
535 strcpy(buf, inet_ntoa(ip->ip_dst));
536 log(LOG_INFO,
537 "Connection attempt to UDP %s:%d from %s:%d\n",
538 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
539 ntohs(uh->uh_sport));
540 }
541 V_udpstat.udps_noport++;
542 if (m->m_flags & (M_BCAST | M_MCAST)) {
543 V_udpstat.udps_noportbcast++;
544 goto badheadlocked;
545 }
546 if (V_udp_blackhole)
547 goto badheadlocked;
548 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
549 goto badheadlocked;
550 *ip = save_ip;
551 ip->ip_len += iphlen;
552 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
553 INP_INFO_RUNLOCK(&V_udbinfo);
554 return;
555 }
556
557 /*
558 * Check the minimum TTL for socket.
559 */
560 INP_RLOCK(inp);
561 INP_INFO_RUNLOCK(&V_udbinfo);
562 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
563 INP_RUNLOCK(inp);
564 goto badunlocked;
565 }
566 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
567 INP_RUNLOCK(inp);
568 return;
569
570badheadlocked:
571 if (inp)
572 INP_RUNLOCK(inp);
573 INP_INFO_RUNLOCK(&V_udbinfo);
574badunlocked:
575 m_freem(m);
576}
577
578/*
579 * Notify a udp user of an asynchronous error; just wake up so that they can
580 * collect error status.
581 */
582struct inpcb *
583udp_notify(struct inpcb *inp, int errno)
584{
585
586 /*
587 * While udp_ctlinput() always calls udp_notify() with a read lock
588 * when invoking it directly, in_pcbnotifyall() currently uses write
589 * locks due to sharing code with TCP. For now, accept either a read
590 * or a write lock, but a read lock is sufficient.
591 */
592 INP_LOCK_ASSERT(inp);
593
594 inp->inp_socket->so_error = errno;
595 sorwakeup(inp->inp_socket);
596 sowwakeup(inp->inp_socket);
597 return (inp);
598}
599
600void
601udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
602{
603 INIT_VNET_INET(curvnet);
604 struct ip *ip = vip;
605 struct udphdr *uh;
606 struct in_addr faddr;
607 struct inpcb *inp;
608
609 faddr = ((struct sockaddr_in *)sa)->sin_addr;
610 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
611 return;
612
613 /*
614 * Redirects don't need to be handled up here.
615 */
616 if (PRC_IS_REDIRECT(cmd))
617 return;
618
619 /*
620 * Hostdead is ugly because it goes linearly through all PCBs.
621 *
622 * XXX: We never get this from ICMP, otherwise it makes an excellent
623 * DoS attack on machines with many connections.
624 */
625 if (cmd == PRC_HOSTDEAD)
626 ip = NULL;
627 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
628 return;
629 if (ip != NULL) {
630 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
631 INP_INFO_RLOCK(&V_udbinfo);
632 inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
633 ip->ip_src, uh->uh_sport, 0, NULL);
634 if (inp != NULL) {
635 INP_RLOCK(inp);
636 if (inp->inp_socket != NULL) {
637 udp_notify(inp, inetctlerrmap[cmd]);
638 }
639 INP_RUNLOCK(inp);
640 }
641 INP_INFO_RUNLOCK(&V_udbinfo);
642 } else
643 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
644 udp_notify);
645}
646
647static int
648udp_pcblist(SYSCTL_HANDLER_ARGS)
649{
650 INIT_VNET_INET(curvnet);
651 int error, i, n;
652 struct inpcb *inp, **inp_list;
653 inp_gen_t gencnt;
654 struct xinpgen xig;
655
656 /*
657 * The process of preparing the PCB list is too time-consuming and
658 * resource-intensive to repeat twice on every request.
659 */
660 if (req->oldptr == 0) {
661 n = V_udbinfo.ipi_count;
662 req->oldidx = 2 * (sizeof xig)
663 + (n + n/8) * sizeof(struct xinpcb);
664 return (0);
665 }
666
667 if (req->newptr != 0)
668 return (EPERM);
669
670 /*
671 * OK, now we're committed to doing something.
672 */
673 INP_INFO_RLOCK(&V_udbinfo);
674 gencnt = V_udbinfo.ipi_gencnt;
675 n = V_udbinfo.ipi_count;
676 INP_INFO_RUNLOCK(&V_udbinfo);
677
678 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
679 + n * sizeof(struct xinpcb));
680 if (error != 0)
681 return (error);
682
683 xig.xig_len = sizeof xig;
684 xig.xig_count = n;
685 xig.xig_gen = gencnt;
686 xig.xig_sogen = so_gencnt;
687 error = SYSCTL_OUT(req, &xig, sizeof xig);
688 if (error)
689 return (error);
690
691 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
692 if (inp_list == 0)
693 return (ENOMEM);
694
695 INP_INFO_RLOCK(&V_udbinfo);
696 for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
697 inp = LIST_NEXT(inp, inp_list)) {
698 INP_RLOCK(inp);
699 if (inp->inp_gencnt <= gencnt &&
700 cr_canseeinpcb(req->td->td_ucred, inp) == 0)
701 inp_list[i++] = inp;
702 INP_RUNLOCK(inp);
703 }
704 INP_INFO_RUNLOCK(&V_udbinfo);
705 n = i;
706
707 error = 0;
708 for (i = 0; i < n; i++) {
709 inp = inp_list[i];
710 INP_RLOCK(inp);
711 if (inp->inp_gencnt <= gencnt) {
712 struct xinpcb xi;
713 bzero(&xi, sizeof(xi));
714 xi.xi_len = sizeof xi;
715 /* XXX should avoid extra copy */
716 bcopy(inp, &xi.xi_inp, sizeof *inp);
717 if (inp->inp_socket)
718 sotoxsocket(inp->inp_socket, &xi.xi_socket);
719 xi.xi_inp.inp_gencnt = inp->inp_gencnt;
720 INP_RUNLOCK(inp);
721 error = SYSCTL_OUT(req, &xi, sizeof xi);
722 } else
723 INP_RUNLOCK(inp);
724 }
725 if (!error) {
726 /*
727 * Give the user an updated idea of our state. If the
728 * generation differs from what we told her before, she knows
729 * that something happened while we were processing this
730 * request, and it might be necessary to retry.
731 */
732 INP_INFO_RLOCK(&V_udbinfo);
733 xig.xig_gen = V_udbinfo.ipi_gencnt;
734 xig.xig_sogen = so_gencnt;
735 xig.xig_count = V_udbinfo.ipi_count;
736 INP_INFO_RUNLOCK(&V_udbinfo);
737 error = SYSCTL_OUT(req, &xig, sizeof xig);
738 }
739 free(inp_list, M_TEMP);
740 return (error);
741}
742
743SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
744 udp_pcblist, "S,xinpcb", "List of active UDP sockets");
745
746static int
747udp_getcred(SYSCTL_HANDLER_ARGS)
748{
749 INIT_VNET_INET(curvnet);
750 struct xucred xuc;
751 struct sockaddr_in addrs[2];
752 struct inpcb *inp;
753 int error;
754
755 error = priv_check(req->td, PRIV_NETINET_GETCRED);
756 if (error)
757 return (error);
758 error = SYSCTL_IN(req, addrs, sizeof(addrs));
759 if (error)
760 return (error);
761 INP_INFO_RLOCK(&V_udbinfo);
762 inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
763 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
764 if (inp != NULL) {
765 INP_RLOCK(inp);
766 INP_INFO_RUNLOCK(&V_udbinfo);
767 if (inp->inp_socket == NULL)
768 error = ENOENT;
769 if (error == 0)
770 error = cr_canseeinpcb(req->td->td_ucred, inp);
771 if (error == 0)
772 cru2x(inp->inp_cred, &xuc);
773 INP_RUNLOCK(inp);
774 } else {
775 INP_INFO_RUNLOCK(&V_udbinfo);
776 error = ENOENT;
777 }
778 if (error == 0)
779 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
780 return (error);
781}
782
783SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
784 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
785 udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
786
787static int
788udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
789 struct mbuf *control, struct thread *td)
790{
791 INIT_VNET_INET(inp->inp_vnet);
792 struct udpiphdr *ui;
793 int len = m->m_pkthdr.len;
794 struct in_addr faddr, laddr;
795 struct cmsghdr *cm;
796 struct sockaddr_in *sin, src;
797 int error = 0;
798 int ipflags;
799 u_short fport, lport;
800 int unlock_udbinfo;
801
802 /*
803 * udp_output() may need to temporarily bind or connect the current
804 * inpcb. As such, we don't know up front whether we will need the
805 * pcbinfo lock or not. Do any work to decide what is needed up
806 * front before acquiring any locks.
807 */
808 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
809 if (control)
810 m_freem(control);
811 m_freem(m);
812 return (EMSGSIZE);
813 }
814
815 src.sin_family = 0;
816 if (control != NULL) {
817 /*
818 * XXX: Currently, we assume all the optional information is
819 * stored in a single mbuf.
820 */
821 if (control->m_next) {
822 m_freem(control);
823 m_freem(m);
824 return (EINVAL);
825 }
826 for (; control->m_len > 0;
827 control->m_data += CMSG_ALIGN(cm->cmsg_len),
828 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
829 cm = mtod(control, struct cmsghdr *);
830 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
831 || cm->cmsg_len > control->m_len) {
832 error = EINVAL;
833 break;
834 }
835 if (cm->cmsg_level != IPPROTO_IP)
836 continue;
837
838 switch (cm->cmsg_type) {
839 case IP_SENDSRCADDR:
840 if (cm->cmsg_len !=
841 CMSG_LEN(sizeof(struct in_addr))) {
842 error = EINVAL;
843 break;
844 }
845 bzero(&src, sizeof(src));
846 src.sin_family = AF_INET;
847 src.sin_len = sizeof(src);
848 src.sin_port = inp->inp_lport;
849 src.sin_addr =
850 *(struct in_addr *)CMSG_DATA(cm);
851 break;
852
853 default:
854 error = ENOPROTOOPT;
855 break;
856 }
857 if (error)
858 break;
859 }
860 m_freem(control);
861 }
862 if (error) {
863 m_freem(m);
864 return (error);
865 }
866
867 /*
868 * Depending on whether or not the application has bound or connected
869 * the socket, we may have to do varying levels of work. The optimal
870 * case is for a connected UDP socket, as a global lock isn't
871 * required at all.
872 *
873 * In order to decide which we need, we require stability of the
874 * inpcb binding, which we ensure by acquiring a read lock on the
875 * inpcb. This doesn't strictly follow the lock order, so we play
876 * the trylock and retry game; note that we may end up with more
877 * conservative locks than required the second time around, so later
878 * assertions have to accept that. Further analysis of the number of
879 * misses under contention is required.
880 */
881 sin = (struct sockaddr_in *)addr;
882 INP_RLOCK(inp);
883 if (sin != NULL &&
884 (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
885 INP_RUNLOCK(inp);
886 INP_INFO_WLOCK(&V_udbinfo);
887 INP_WLOCK(inp);
888 unlock_udbinfo = 2;
889 } else if ((sin != NULL && (
890 (sin->sin_addr.s_addr == INADDR_ANY) ||
891 (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
892 (inp->inp_laddr.s_addr == INADDR_ANY) ||
893 (inp->inp_lport == 0))) ||
894 (src.sin_family == AF_INET)) {
895 if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
896 INP_RUNLOCK(inp);
897 INP_INFO_RLOCK(&V_udbinfo);
898 INP_RLOCK(inp);
899 }
900 unlock_udbinfo = 1;
901 } else
902 unlock_udbinfo = 0;
903
904 /*
905 * If the IP_SENDSRCADDR control message was specified, override the
906 * source address for this datagram. Its use is invalidated if the
907 * address thus specified is incomplete or clobbers other inpcbs.
908 */
909 laddr = inp->inp_laddr;
910 lport = inp->inp_lport;
911 if (src.sin_family == AF_INET) {
912 INP_INFO_LOCK_ASSERT(&V_udbinfo);
913 if ((lport == 0) ||
914 (laddr.s_addr == INADDR_ANY &&
915 src.sin_addr.s_addr == INADDR_ANY)) {
916 error = EINVAL;
917 goto release;
918 }
919 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
920 &laddr.s_addr, &lport, td->td_ucred);
921 if (error)
922 goto release;
923 }
924
925 /*
926 * If a UDP socket has been connected, then a local address/port will
927 * have been selected and bound.
928 *
929 * If a UDP socket has not been connected to, then an explicit
930 * destination address must be used, in which case a local
931 * address/port may not have been selected and bound.
932 */
933 if (sin != NULL) {
934 INP_LOCK_ASSERT(inp);
935 if (inp->inp_faddr.s_addr != INADDR_ANY) {
936 error = EISCONN;
937 goto release;
938 }
939
940 /*
941 * Jail may rewrite the destination address, so let it do
942 * that before we use it.
943 */
944 if (prison_remote_ip4(td->td_ucred, &sin->sin_addr) != 0) {
945 error = EINVAL;
946 goto release;
947 }
948
949 /*
950 * If a local address or port hasn't yet been selected, or if
951 * the destination address needs to be rewritten due to using
952 * a special INADDR_ constant, invoke in_pcbconnect_setup()
953 * to do the heavy lifting. Once a port is selected, we
954 * commit the binding back to the socket; we also commit the
955 * binding of the address if in jail.
956 *
957 * If we already have a valid binding and we're not
958 * requesting a destination address rewrite, use a fast path.
959 */
960 if (inp->inp_laddr.s_addr == INADDR_ANY ||
961 inp->inp_lport == 0 ||
962 sin->sin_addr.s_addr == INADDR_ANY ||
963 sin->sin_addr.s_addr == INADDR_BROADCAST) {
964 INP_INFO_LOCK_ASSERT(&V_udbinfo);
965 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
966 &lport, &faddr.s_addr, &fport, NULL,
967 td->td_ucred);
968 if (error)
969 goto release;
970
971 /*
972 * XXXRW: Why not commit the port if the address is
973 * !INADDR_ANY?
974 */
975 /* Commit the local port if newly assigned. */
976 if (inp->inp_laddr.s_addr == INADDR_ANY &&
977 inp->inp_lport == 0) {
978 INP_INFO_WLOCK_ASSERT(&V_udbinfo);
979 INP_WLOCK_ASSERT(inp);
980 /*
981 * Remember addr if jailed, to prevent
982 * rebinding.
983 */
984 if (jailed(td->td_ucred))
985 inp->inp_laddr = laddr;
986 inp->inp_lport = lport;
987 if (in_pcbinshash(inp) != 0) {
988 inp->inp_lport = 0;
989 error = EAGAIN;
990 goto release;
991 }
992 inp->inp_flags |= INP_ANONPORT;
993 }
994 } else {
995 faddr = sin->sin_addr;
996 fport = sin->sin_port;
997 }
998 } else {
999 INP_LOCK_ASSERT(inp);
1000 faddr = inp->inp_faddr;
1001 fport = inp->inp_fport;
1002 if (faddr.s_addr == INADDR_ANY) {
1003 error = ENOTCONN;
1004 goto release;
1005 }
1006 }
1007
1008 /*
1009 * Calculate data length and get a mbuf for UDP, IP, and possible
1010 * link-layer headers. Immediate slide the data pointer back forward
1011 * since we won't use that space at this layer.
1012 */
1013 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1014 if (m == NULL) {
1015 error = ENOBUFS;
1016 goto release;
1017 }
1018 m->m_data += max_linkhdr;
1019 m->m_len -= max_linkhdr;
1020 m->m_pkthdr.len -= max_linkhdr;
1021
1022 /*
1023 * Fill in mbuf with extended UDP header and addresses and length put
1024 * into network format.
1025 */
1026 ui = mtod(m, struct udpiphdr *);
1027 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */
1028 ui->ui_pr = IPPROTO_UDP;
1029 ui->ui_src = laddr;
1030 ui->ui_dst = faddr;
1031 ui->ui_sport = lport;
1032 ui->ui_dport = fport;
1033 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1034
1035 /*
1036 * Set the Don't Fragment bit in the IP header.
1037 */
1038 if (inp->inp_flags & INP_DONTFRAG) {
1039 struct ip *ip;
1040
1041 ip = (struct ip *)&ui->ui_i;
1042 ip->ip_off |= IP_DF;
1043 }
1044
1045 ipflags = 0;
1046 if (inp->inp_socket->so_options & SO_DONTROUTE)
1047 ipflags |= IP_ROUTETOIF;
1048 if (inp->inp_socket->so_options & SO_BROADCAST)
1049 ipflags |= IP_ALLOWBROADCAST;
1050 if (inp->inp_flags & INP_ONESBCAST)
1051 ipflags |= IP_SENDONES;
1052
1053#ifdef MAC
1054 mac_inpcb_create_mbuf(inp, m);
1055#endif
1056
1057 /*
1058 * Set up checksum and output datagram.
1059 */
1060 if (udp_cksum) {
1061 if (inp->inp_flags & INP_ONESBCAST)
1062 faddr.s_addr = INADDR_BROADCAST;
1063 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1064 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1065 m->m_pkthdr.csum_flags = CSUM_UDP;
1066 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1067 } else
1068 ui->ui_sum = 0;
1069 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1070 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
1071 ((struct ip *)ui)->ip_tos = inp->inp_ip_tos; /* XXX */
1072 V_udpstat.udps_opackets++;
1073
1074 if (unlock_udbinfo == 2)
1075 INP_INFO_WUNLOCK(&V_udbinfo);
1076 else if (unlock_udbinfo == 1)
1077 INP_INFO_RUNLOCK(&V_udbinfo);
1078 error = ip_output(m, inp->inp_options, NULL, ipflags,
1079 inp->inp_moptions, inp);
1080 if (unlock_udbinfo == 2)
1081 INP_WUNLOCK(inp);
1082 else
1083 INP_RUNLOCK(inp);
1084 return (error);
1085
1086release:
1087 if (unlock_udbinfo == 2) {
1088 INP_WUNLOCK(inp);
1089 INP_INFO_WUNLOCK(&V_udbinfo);
1090 } else if (unlock_udbinfo == 1) {
1091 INP_RUNLOCK(inp);
1092 INP_INFO_RUNLOCK(&V_udbinfo);
1093 } else
1094 INP_RUNLOCK(inp);
1095 m_freem(m);
1096 return (error);
1097}
1098
1099static void
1100udp_abort(struct socket *so)
1101{
1102 INIT_VNET_INET(so->so_vnet);
1103 struct inpcb *inp;
1104
1105 inp = sotoinpcb(so);
1106 KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1107 INP_INFO_WLOCK(&V_udbinfo);
1108 INP_WLOCK(inp);
1109 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1110 in_pcbdisconnect(inp);
1111 inp->inp_laddr.s_addr = INADDR_ANY;
1112 soisdisconnected(so);
1113 }
1114 INP_WUNLOCK(inp);
1115 INP_INFO_WUNLOCK(&V_udbinfo);
1116}
1117
1118static int
1119udp_attach(struct socket *so, int proto, struct thread *td)
1120{
1121 INIT_VNET_INET(so->so_vnet);
1122 struct inpcb *inp;
1123 int error;
1124
1125 inp = sotoinpcb(so);
1126 KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1127 error = soreserve(so, udp_sendspace, udp_recvspace);
1128 if (error)
1129 return (error);
1130 INP_INFO_WLOCK(&V_udbinfo);
1131 error = in_pcballoc(so, &V_udbinfo);
1132 if (error) {
1133 INP_INFO_WUNLOCK(&V_udbinfo);
1134 return (error);
1135 }
1136
1137 inp = (struct inpcb *)so->so_pcb;
1138 INP_INFO_WUNLOCK(&V_udbinfo);
1139 inp->inp_vflag |= INP_IPV4;
1140 inp->inp_ip_ttl = V_ip_defttl;
1141 INP_WUNLOCK(inp);
1142 return (0);
1143}
1144
1145static int
1146udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1147{
1148 INIT_VNET_INET(so->so_vnet);
1149 struct inpcb *inp;
1150 int error;
1151
1152 inp = sotoinpcb(so);
1153 KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1154 INP_INFO_WLOCK(&V_udbinfo);
1155 INP_WLOCK(inp);
1156 error = in_pcbbind(inp, nam, td->td_ucred);
1157 INP_WUNLOCK(inp);
1158 INP_INFO_WUNLOCK(&V_udbinfo);
1159 return (error);
1160}
1161
1162static void
1163udp_close(struct socket *so)
1164{
1165 INIT_VNET_INET(so->so_vnet);
1166 struct inpcb *inp;
1167
1168 inp = sotoinpcb(so);
1169 KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1170 INP_INFO_WLOCK(&V_udbinfo);
1171 INP_WLOCK(inp);
1172 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1173 in_pcbdisconnect(inp);
1174 inp->inp_laddr.s_addr = INADDR_ANY;
1175 soisdisconnected(so);
1176 }
1177 INP_WUNLOCK(inp);
1178 INP_INFO_WUNLOCK(&V_udbinfo);
1179}
1180
1181static int
1182udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1183{
1184 INIT_VNET_INET(so->so_vnet);
1185 struct inpcb *inp;
1186 int error;
1187 struct sockaddr_in *sin;
1188
1189 inp = sotoinpcb(so);
1190 KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1191 INP_INFO_WLOCK(&V_udbinfo);
1192 INP_WLOCK(inp);
1193 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1194 INP_WUNLOCK(inp);
1195 INP_INFO_WUNLOCK(&V_udbinfo);
1196 return (EISCONN);
1197 }
1198 sin = (struct sockaddr_in *)nam;
1199 if (prison_remote_ip4(td->td_ucred, &sin->sin_addr) != 0) {
1200 INP_WUNLOCK(inp);
1201 INP_INFO_WUNLOCK(&udbinfo);
1202 return (EAFNOSUPPORT);
1203 }
1204 error = in_pcbconnect(inp, nam, td->td_ucred);
1205 if (error == 0)
1206 soisconnected(so);
1207 INP_WUNLOCK(inp);
1208 INP_INFO_WUNLOCK(&V_udbinfo);
1209 return (error);
1210}
1211
1212static void
1213udp_detach(struct socket *so)
1214{
1215 INIT_VNET_INET(so->so_vnet);
1216 struct inpcb *inp;
1217
1218 inp = sotoinpcb(so);
1219 KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1220 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1221 ("udp_detach: not disconnected"));
1222 INP_INFO_WLOCK(&V_udbinfo);
1223 INP_WLOCK(inp);
1224 in_pcbdetach(inp);
1225 in_pcbfree(inp);
1226 INP_INFO_WUNLOCK(&V_udbinfo);
1227}
1228
1229static int
1230udp_disconnect(struct socket *so)
1231{
1232 INIT_VNET_INET(so->so_vnet);
1233 struct inpcb *inp;
1234
1235 inp = sotoinpcb(so);
1236 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1237 INP_INFO_WLOCK(&V_udbinfo);
1238 INP_WLOCK(inp);
1239 if (inp->inp_faddr.s_addr == INADDR_ANY) {
1240 INP_WUNLOCK(inp);
1241 INP_INFO_WUNLOCK(&V_udbinfo);
1242 return (ENOTCONN);
1243 }
1244
1245 in_pcbdisconnect(inp);
1246 inp->inp_laddr.s_addr = INADDR_ANY;
1247 SOCK_LOCK(so);
1248 so->so_state &= ~SS_ISCONNECTED; /* XXX */
1249 SOCK_UNLOCK(so);
1250 INP_WUNLOCK(inp);
1251 INP_INFO_WUNLOCK(&V_udbinfo);
1252 return (0);
1253}
1254
1255static int
1256udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1257 struct mbuf *control, struct thread *td)
1258{
1259 struct inpcb *inp;
1260
1261 inp = sotoinpcb(so);
1262 KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1263 return (udp_output(inp, m, addr, control, td));
1264}
1265
1266int
1267udp_shutdown(struct socket *so)
1268{
1269 struct inpcb *inp;
1270
1271 inp = sotoinpcb(so);
1272 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1273 INP_WLOCK(inp);
1274 socantsendmore(so);
1275 INP_WUNLOCK(inp);
1276 return (0);
1277}
1278
1279struct pr_usrreqs udp_usrreqs = {
1280 .pru_abort = udp_abort,
1281 .pru_attach = udp_attach,
1282 .pru_bind = udp_bind,
1283 .pru_connect = udp_connect,
1284 .pru_control = in_control,
1285 .pru_detach = udp_detach,
1286 .pru_disconnect = udp_disconnect,
1287 .pru_peeraddr = in_getpeeraddr,
1288 .pru_send = udp_send,
1289 .pru_soreceive = soreceive_dgram,
1290 .pru_sosend = sosend_dgram,
1291 .pru_shutdown = udp_shutdown,
1292 .pru_sockaddr = in_getsockaddr,
1293 .pru_sosetlabel = in_pcbsosetlabel,
1294 .pru_close = udp_close,
1295};
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