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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