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1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * Copyright (c) 2010-2011 Juniper Networks, Inc.
4  * Copyright (c) 2014 Kevin Lo
5  * All rights reserved.
6  *
7  * Portions of this software were developed by Robert N. M. Watson under
8  * contract to Juniper Networks, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the project nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *      $KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
35  *      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
36  */
37
38 /*-
39  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
40  *      The Regents of the University of California.
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 4. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
68  */
69
70 #include <sys/cdefs.h>
71 __FBSDID("$FreeBSD$");
72
73 #include "opt_inet.h"
74 #include "opt_inet6.h"
75 #include "opt_ipfw.h"
76 #include "opt_ipsec.h"
77 #include "opt_rss.h"
78
79 #include <sys/param.h>
80 #include <sys/jail.h>
81 #include <sys/kernel.h>
82 #include <sys/lock.h>
83 #include <sys/mbuf.h>
84 #include <sys/priv.h>
85 #include <sys/proc.h>
86 #include <sys/protosw.h>
87 #include <sys/sdt.h>
88 #include <sys/signalvar.h>
89 #include <sys/socket.h>
90 #include <sys/socketvar.h>
91 #include <sys/sx.h>
92 #include <sys/sysctl.h>
93 #include <sys/syslog.h>
94 #include <sys/systm.h>
95
96 #include <net/if.h>
97 #include <net/if_var.h>
98 #include <net/if_types.h>
99 #include <net/route.h>
100 #include <net/rss_config.h>
101
102 #include <netinet/in.h>
103 #include <netinet/in_kdtrace.h>
104 #include <netinet/in_pcb.h>
105 #include <netinet/in_systm.h>
106 #include <netinet/in_var.h>
107 #include <netinet/ip.h>
108 #include <netinet/ip_icmp.h>
109 #include <netinet/ip6.h>
110 #include <netinet/icmp_var.h>
111 #include <netinet/icmp6.h>
112 #include <netinet/ip_var.h>
113 #include <netinet/udp.h>
114 #include <netinet/udp_var.h>
115 #include <netinet/udplite.h>
116
117 #include <netinet6/ip6protosw.h>
118 #include <netinet6/ip6_var.h>
119 #include <netinet6/in6_pcb.h>
120 #include <netinet6/in6_rss.h>
121 #include <netinet6/udp6_var.h>
122 #include <netinet6/scope6_var.h>
123
124 #ifdef IPSEC
125 #include <netipsec/ipsec.h>
126 #include <netipsec/ipsec6.h>
127 #endif /* IPSEC */
128
129 #include <security/mac/mac_framework.h>
130
131 /*
132  * UDP protocol implementation.
133  * Per RFC 768, August, 1980.
134  */
135
136 extern struct protosw   inetsw[];
137 static void             udp6_detach(struct socket *so);
138
139 static int
140 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
141     struct sockaddr_in6 *fromsa)
142 {
143         struct socket *so;
144         struct mbuf *opts;
145         struct udpcb *up;
146
147         INP_LOCK_ASSERT(inp);
148
149         /*
150          * Engage the tunneling protocol.
151          */
152         up = intoudpcb(inp);
153         if (up->u_tun_func != NULL) {
154                 in_pcbref(inp);
155                 INP_RUNLOCK(inp);
156                 (*up->u_tun_func)(n, off, inp, (struct sockaddr *)fromsa,
157                     up->u_tun_ctx);
158                 INP_RLOCK(inp);
159                 return (in_pcbrele_rlocked(inp));
160         }
161 #ifdef IPSEC
162         /* Check AH/ESP integrity. */
163         if (ipsec6_in_reject(n, inp)) {
164                 m_freem(n);
165                 return (0);
166         }
167 #endif /* IPSEC */
168 #ifdef MAC
169         if (mac_inpcb_check_deliver(inp, n) != 0) {
170                 m_freem(n);
171                 return (0);
172         }
173 #endif
174         opts = NULL;
175         if (inp->inp_flags & INP_CONTROLOPTS ||
176             inp->inp_socket->so_options & SO_TIMESTAMP)
177                 ip6_savecontrol(inp, n, &opts);
178         m_adj(n, off + sizeof(struct udphdr));
179
180         so = inp->inp_socket;
181         SOCKBUF_LOCK(&so->so_rcv);
182         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
183             opts) == 0) {
184                 SOCKBUF_UNLOCK(&so->so_rcv);
185                 m_freem(n);
186                 if (opts)
187                         m_freem(opts);
188                 UDPSTAT_INC(udps_fullsock);
189         } else
190                 sorwakeup_locked(so);
191         return (0);
192 }
193
194 int
195 udp6_input(struct mbuf **mp, int *offp, int proto)
196 {
197         struct mbuf *m = *mp;
198         struct ifnet *ifp;
199         struct ip6_hdr *ip6;
200         struct udphdr *uh;
201         struct inpcb *inp;
202         struct inpcbinfo *pcbinfo;
203         struct udpcb *up;
204         int off = *offp;
205         int cscov_partial;
206         int plen, ulen;
207         struct sockaddr_in6 fromsa;
208         struct m_tag *fwd_tag;
209         uint16_t uh_sum;
210         uint8_t nxt;
211
212         ifp = m->m_pkthdr.rcvif;
213         ip6 = mtod(m, struct ip6_hdr *);
214
215 #ifndef PULLDOWN_TEST
216         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
217         ip6 = mtod(m, struct ip6_hdr *);
218         uh = (struct udphdr *)((caddr_t)ip6 + off);
219 #else
220         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
221         if (!uh)
222                 return (IPPROTO_DONE);
223 #endif
224
225         UDPSTAT_INC(udps_ipackets);
226
227         /*
228          * Destination port of 0 is illegal, based on RFC768.
229          */
230         if (uh->uh_dport == 0)
231                 goto badunlocked;
232
233         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
234         ulen = ntohs((u_short)uh->uh_ulen);
235
236         nxt = proto;
237         cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
238         if (nxt == IPPROTO_UDPLITE) {
239                 /* Zero means checksum over the complete packet. */
240                 if (ulen == 0)
241                         ulen = plen;
242                 if (ulen == plen)
243                         cscov_partial = 0;
244                 if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
245                         /* XXX: What is the right UDPLite MIB counter? */
246                         goto badunlocked;
247                 }
248                 if (uh->uh_sum == 0) {
249                         /* XXX: What is the right UDPLite MIB counter? */
250                         goto badunlocked;
251                 }
252         } else {
253                 if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
254                         UDPSTAT_INC(udps_badlen);
255                         goto badunlocked;
256                 }
257                 if (uh->uh_sum == 0) {
258                         UDPSTAT_INC(udps_nosum);
259                         goto badunlocked;
260                 }
261         }
262
263         if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
264             !cscov_partial) {
265                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
266                         uh_sum = m->m_pkthdr.csum_data;
267                 else
268                         uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
269                             m->m_pkthdr.csum_data);
270                 uh_sum ^= 0xffff;
271         } else
272                 uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
273
274         if (uh_sum != 0) {
275                 UDPSTAT_INC(udps_badsum);
276                 goto badunlocked;
277         }
278
279         /*
280          * Construct sockaddr format source address.
281          */
282         init_sin6(&fromsa, m);
283         fromsa.sin6_port = uh->uh_sport;
284
285         pcbinfo = udp_get_inpcbinfo(nxt);
286         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
287                 struct inpcb *last;
288                 struct inpcbhead *pcblist;
289                 struct ip6_moptions *imo;
290
291                 INP_INFO_RLOCK(pcbinfo);
292                 /*
293                  * In the event that laddr should be set to the link-local
294                  * address (this happens in RIPng), the multicast address
295                  * specified in the received packet will not match laddr.  To
296                  * handle this situation, matching is relaxed if the
297                  * receiving interface is the same as one specified in the
298                  * socket and if the destination multicast address matches
299                  * one of the multicast groups specified in the socket.
300                  */
301
302                 /*
303                  * KAME note: traditionally we dropped udpiphdr from mbuf
304                  * here.  We need udphdr for IPsec processing so we do that
305                  * later.
306                  */
307                 pcblist = udp_get_pcblist(nxt);
308                 last = NULL;
309                 LIST_FOREACH(inp, pcblist, inp_list) {
310                         if ((inp->inp_vflag & INP_IPV6) == 0)
311                                 continue;
312                         if (inp->inp_lport != uh->uh_dport)
313                                 continue;
314                         if (inp->inp_fport != 0 &&
315                             inp->inp_fport != uh->uh_sport)
316                                 continue;
317                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
318                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
319                                                         &ip6->ip6_dst))
320                                         continue;
321                         }
322                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
323                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
324                                                         &ip6->ip6_src) ||
325                                     inp->inp_fport != uh->uh_sport)
326                                         continue;
327                         }
328
329                         /*
330                          * XXXRW: Because we weren't holding either the inpcb
331                          * or the hash lock when we checked for a match 
332                          * before, we should probably recheck now that the 
333                          * inpcb lock is (supposed to be) held.
334                          */
335
336                         /*
337                          * Handle socket delivery policy for any-source
338                          * and source-specific multicast. [RFC3678]
339                          */
340                         imo = inp->in6p_moptions;
341                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
342                                 struct sockaddr_in6      mcaddr;
343                                 int                      blocked;
344
345                                 INP_RLOCK(inp);
346
347                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
348                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
349                                 mcaddr.sin6_family = AF_INET6;
350                                 mcaddr.sin6_addr = ip6->ip6_dst;
351
352                                 blocked = im6o_mc_filter(imo, ifp,
353                                         (struct sockaddr *)&mcaddr,
354                                         (struct sockaddr *)&fromsa);
355                                 if (blocked != MCAST_PASS) {
356                                         if (blocked == MCAST_NOTGMEMBER)
357                                                 IP6STAT_INC(ip6s_notmember);
358                                         if (blocked == MCAST_NOTSMEMBER ||
359                                             blocked == MCAST_MUTED)
360                                                 UDPSTAT_INC(udps_filtermcast);
361                                         INP_RUNLOCK(inp); /* XXX */
362                                         continue;
363                                 }
364
365                                 INP_RUNLOCK(inp);
366                         }
367                         if (last != NULL) {
368                                 struct mbuf *n;
369
370                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
371                                         INP_RLOCK(last);
372                                         UDP_PROBE(receive, NULL, last, ip6,
373                                             last, uh);
374                                         if (udp6_append(last, n, off, &fromsa))
375                                                 goto inp_lost;
376                                         INP_RUNLOCK(last);
377                                 }
378                         }
379                         last = inp;
380                         /*
381                          * Don't look for additional matches if this one does
382                          * not have either the SO_REUSEPORT or SO_REUSEADDR
383                          * socket options set.  This heuristic avoids
384                          * searching through all pcbs in the common case of a
385                          * non-shared port.  It assumes that an application
386                          * will never clear these options after setting them.
387                          */
388                         if ((last->inp_socket->so_options &
389                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
390                                 break;
391                 }
392
393                 if (last == NULL) {
394                         /*
395                          * No matching pcb found; discard datagram.  (No need
396                          * to send an ICMP Port Unreachable for a broadcast
397                          * or multicast datgram.)
398                          */
399                         UDPSTAT_INC(udps_noport);
400                         UDPSTAT_INC(udps_noportmcast);
401                         goto badheadlocked;
402                 }
403                 INP_RLOCK(last);
404                 INP_INFO_RUNLOCK(pcbinfo);
405                 UDP_PROBE(receive, NULL, last, ip6, last, uh);
406                 if (udp6_append(last, m, off, &fromsa) == 0) 
407                         INP_RUNLOCK(last);
408         inp_lost:
409                 return (IPPROTO_DONE);
410         }
411         /*
412          * Locate pcb for datagram.
413          */
414
415         /*
416          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
417          */
418         if ((m->m_flags & M_IP6_NEXTHOP) &&
419             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
420                 struct sockaddr_in6 *next_hop6;
421
422                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
423
424                 /*
425                  * Transparently forwarded. Pretend to be the destination.
426                  * Already got one like this?
427                  */
428                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
429                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
430                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
431                 if (!inp) {
432                         /*
433                          * It's new.  Try to find the ambushing socket.
434                          * Because we've rewritten the destination address,
435                          * any hardware-generated hash is ignored.
436                          */
437                         inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
438                             uh->uh_sport, &next_hop6->sin6_addr,
439                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
440                             uh->uh_dport, INPLOOKUP_WILDCARD |
441                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
442                 }
443                 /* Remove the tag from the packet. We don't need it anymore. */
444                 m_tag_delete(m, fwd_tag);
445                 m->m_flags &= ~M_IP6_NEXTHOP;
446         } else
447                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
448                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
449                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
450                     m->m_pkthdr.rcvif, m);
451         if (inp == NULL) {
452                 if (udp_log_in_vain) {
453                         char ip6bufs[INET6_ADDRSTRLEN];
454                         char ip6bufd[INET6_ADDRSTRLEN];
455
456                         log(LOG_INFO,
457                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
458                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
459                             ntohs(uh->uh_dport),
460                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
461                             ntohs(uh->uh_sport));
462                 }
463                 UDPSTAT_INC(udps_noport);
464                 if (m->m_flags & M_MCAST) {
465                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
466                         UDPSTAT_INC(udps_noportmcast);
467                         goto badunlocked;
468                 }
469                 if (V_udp_blackhole)
470                         goto badunlocked;
471                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
472                         goto badunlocked;
473                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
474                 return (IPPROTO_DONE);
475         }
476         INP_RLOCK_ASSERT(inp);
477         up = intoudpcb(inp);
478         if (cscov_partial) {
479                 if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
480                         INP_RUNLOCK(inp);
481                         m_freem(m);
482                         return (IPPROTO_DONE);
483                 }
484         }
485         UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
486         if (udp6_append(inp, m, off, &fromsa) == 0)
487                 INP_RUNLOCK(inp);
488         return (IPPROTO_DONE);
489
490 badheadlocked:
491         INP_INFO_RUNLOCK(pcbinfo);
492 badunlocked:
493         if (m)
494                 m_freem(m);
495         return (IPPROTO_DONE);
496 }
497
498 static void
499 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
500     struct inpcbinfo *pcbinfo)
501 {
502         struct udphdr uh;
503         struct ip6_hdr *ip6;
504         struct mbuf *m;
505         int off = 0;
506         struct ip6ctlparam *ip6cp = NULL;
507         const struct sockaddr_in6 *sa6_src = NULL;
508         void *cmdarg;
509         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
510         struct udp_portonly {
511                 u_int16_t uh_sport;
512                 u_int16_t uh_dport;
513         } *uhp;
514
515         if (sa->sa_family != AF_INET6 ||
516             sa->sa_len != sizeof(struct sockaddr_in6))
517                 return;
518
519         if ((unsigned)cmd >= PRC_NCMDS)
520                 return;
521         if (PRC_IS_REDIRECT(cmd))
522                 notify = in6_rtchange, d = NULL;
523         else if (cmd == PRC_HOSTDEAD)
524                 d = NULL;
525         else if (inet6ctlerrmap[cmd] == 0)
526                 return;
527
528         /* if the parameter is from icmp6, decode it. */
529         if (d != NULL) {
530                 ip6cp = (struct ip6ctlparam *)d;
531                 m = ip6cp->ip6c_m;
532                 ip6 = ip6cp->ip6c_ip6;
533                 off = ip6cp->ip6c_off;
534                 cmdarg = ip6cp->ip6c_cmdarg;
535                 sa6_src = ip6cp->ip6c_src;
536         } else {
537                 m = NULL;
538                 ip6 = NULL;
539                 cmdarg = NULL;
540                 sa6_src = &sa6_any;
541         }
542
543         if (ip6) {
544                 /*
545                  * XXX: We assume that when IPV6 is non NULL,
546                  * M and OFF are valid.
547                  */
548
549                 /* Check if we can safely examine src and dst ports. */
550                 if (m->m_pkthdr.len < off + sizeof(*uhp))
551                         return;
552
553                 bzero(&uh, sizeof(uh));
554                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
555
556                 (void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
557                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
558                     cmdarg, notify);
559         } else
560                 (void)in6_pcbnotify(pcbinfo, sa, 0,
561                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
562 }
563
564 void
565 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
566 {
567
568         return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
569 }
570
571 void
572 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
573 {
574
575         return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
576 }
577
578 static int
579 udp6_getcred(SYSCTL_HANDLER_ARGS)
580 {
581         struct xucred xuc;
582         struct sockaddr_in6 addrs[2];
583         struct inpcb *inp;
584         int error;
585
586         error = priv_check(req->td, PRIV_NETINET_GETCRED);
587         if (error)
588                 return (error);
589
590         if (req->newlen != sizeof(addrs))
591                 return (EINVAL);
592         if (req->oldlen != sizeof(struct xucred))
593                 return (EINVAL);
594         error = SYSCTL_IN(req, addrs, sizeof(addrs));
595         if (error)
596                 return (error);
597         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
598             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
599                 return (error);
600         }
601         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
602             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
603             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
604         if (inp != NULL) {
605                 INP_RLOCK_ASSERT(inp);
606                 if (inp->inp_socket == NULL)
607                         error = ENOENT;
608                 if (error == 0)
609                         error = cr_canseesocket(req->td->td_ucred,
610                             inp->inp_socket);
611                 if (error == 0)
612                         cru2x(inp->inp_cred, &xuc);
613                 INP_RUNLOCK(inp);
614         } else
615                 error = ENOENT;
616         if (error == 0)
617                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
618         return (error);
619 }
620
621 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
622     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
623
624 static int
625 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
626     struct mbuf *control, struct thread *td)
627 {
628         u_int32_t ulen = m->m_pkthdr.len;
629         u_int32_t plen = sizeof(struct udphdr) + ulen;
630         struct ip6_hdr *ip6;
631         struct udphdr *udp6;
632         struct in6_addr *laddr, *faddr, in6a;
633         struct sockaddr_in6 *sin6 = NULL;
634         struct ifnet *oifp = NULL;
635         int cscov_partial = 0;
636         int scope_ambiguous = 0;
637         u_short fport;
638         int error = 0;
639         uint8_t nxt;
640         uint16_t cscov = 0;
641         struct ip6_pktopts *optp, opt;
642         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
643         int flags;
644         struct sockaddr_in6 tmp;
645
646         INP_WLOCK_ASSERT(inp);
647         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
648
649         if (addr6) {
650                 /* addr6 has been validated in udp6_send(). */
651                 sin6 = (struct sockaddr_in6 *)addr6;
652
653                 /* protect *sin6 from overwrites */
654                 tmp = *sin6;
655                 sin6 = &tmp;
656
657                 /*
658                  * Application should provide a proper zone ID or the use of
659                  * default zone IDs should be enabled.  Unfortunately, some
660                  * applications do not behave as it should, so we need a
661                  * workaround.  Even if an appropriate ID is not determined,
662                  * we'll see if we can determine the outgoing interface.  If we
663                  * can, determine the zone ID based on the interface below.
664                  */
665                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
666                         scope_ambiguous = 1;
667                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
668                         return (error);
669         }
670
671         nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
672             IPPROTO_UDP : IPPROTO_UDPLITE;
673         if (control) {
674                 if ((error = ip6_setpktopts(control, &opt,
675                     inp->in6p_outputopts, td->td_ucred, nxt)) != 0)
676                         goto release;
677                 optp = &opt;
678         } else
679                 optp = inp->in6p_outputopts;
680
681         if (sin6) {
682                 faddr = &sin6->sin6_addr;
683
684                 /*
685                  * Since we saw no essential reason for calling in_pcbconnect,
686                  * we get rid of such kind of logic, and call in6_selectsrc
687                  * and in6_pcbsetport in order to fill in the local address
688                  * and the local port.
689                  */
690                 if (sin6->sin6_port == 0) {
691                         error = EADDRNOTAVAIL;
692                         goto release;
693                 }
694
695                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
696                         /* how about ::ffff:0.0.0.0 case? */
697                         error = EISCONN;
698                         goto release;
699                 }
700
701                 fport = sin6->sin6_port; /* allow 0 port */
702
703                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
704                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
705                                 /*
706                                  * I believe we should explicitly discard the
707                                  * packet when mapped addresses are disabled,
708                                  * rather than send the packet as an IPv6 one.
709                                  * If we chose the latter approach, the packet
710                                  * might be sent out on the wire based on the
711                                  * default route, the situation which we'd
712                                  * probably want to avoid.
713                                  * (20010421 jinmei@kame.net)
714                                  */
715                                 error = EINVAL;
716                                 goto release;
717                         }
718                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
719                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
720                                 /*
721                                  * when remote addr is an IPv4-mapped address,
722                                  * local addr should not be an IPv6 address,
723                                  * since you cannot determine how to map IPv6
724                                  * source address to IPv4.
725                                  */
726                                 error = EINVAL;
727                                 goto release;
728                         }
729
730                         af = AF_INET;
731                 }
732
733                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
734                         error = in6_selectsrc(sin6, optp, inp, NULL,
735                             td->td_ucred, &oifp, &in6a);
736                         if (error)
737                                 goto release;
738                         if (oifp && scope_ambiguous &&
739                             (error = in6_setscope(&sin6->sin6_addr,
740                             oifp, NULL))) {
741                                 goto release;
742                         }
743                         laddr = &in6a;
744                 } else
745                         laddr = &inp->in6p_laddr;       /* XXX */
746                 if (laddr == NULL) {
747                         if (error == 0)
748                                 error = EADDRNOTAVAIL;
749                         goto release;
750                 }
751                 if (inp->inp_lport == 0 &&
752                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
753                         /* Undo an address bind that may have occurred. */
754                         inp->in6p_laddr = in6addr_any;
755                         goto release;
756                 }
757         } else {
758                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
759                         error = ENOTCONN;
760                         goto release;
761                 }
762                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
763                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
764                                 /*
765                                  * XXX: this case would happen when the
766                                  * application sets the V6ONLY flag after
767                                  * connecting the foreign address.
768                                  * Such applications should be fixed,
769                                  * so we bark here.
770                                  */
771                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
772                                     "option was set for a connected socket\n");
773                                 error = EINVAL;
774                                 goto release;
775                         } else
776                                 af = AF_INET;
777                 }
778                 laddr = &inp->in6p_laddr;
779                 faddr = &inp->in6p_faddr;
780                 fport = inp->inp_fport;
781         }
782
783         if (af == AF_INET)
784                 hlen = sizeof(struct ip);
785
786         /*
787          * Calculate data length and get a mbuf
788          * for UDP and IP6 headers.
789          */
790         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
791         if (m == NULL) {
792                 error = ENOBUFS;
793                 goto release;
794         }
795
796         /*
797          * Stuff checksum and output datagram.
798          */
799         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
800         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
801         udp6->uh_dport = fport;
802         if (nxt == IPPROTO_UDPLITE) {
803                 struct udpcb *up;
804
805                 up = intoudpcb(inp);
806                 cscov = up->u_txcslen;
807                 if (cscov >= plen)
808                         cscov = 0;
809                 udp6->uh_ulen = htons(cscov);
810                 /*
811                  * For UDP-Lite, checksum coverage length of zero means
812                  * the entire UDPLite packet is covered by the checksum.
813                  */
814                 cscov_partial = (cscov == 0) ? 0 : 1;
815         } else if (plen <= 0xffff)
816                 udp6->uh_ulen = htons((u_short)plen);
817         else
818                 udp6->uh_ulen = 0;
819         udp6->uh_sum = 0;
820
821         switch (af) {
822         case AF_INET6:
823                 ip6 = mtod(m, struct ip6_hdr *);
824                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
825                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
826                 ip6->ip6_vfc    |= IPV6_VERSION;
827                 ip6->ip6_plen   = htons((u_short)plen);
828                 ip6->ip6_nxt    = nxt;
829                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
830                 ip6->ip6_src    = *laddr;
831                 ip6->ip6_dst    = *faddr;
832
833                 if (cscov_partial) {
834                         if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
835                             sizeof(struct ip6_hdr), plen, cscov)) == 0)
836                                 udp6->uh_sum = 0xffff;
837                 } else {
838                         udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
839                         m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
840                         m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
841                 }
842
843 #ifdef  RSS
844                 {
845                         uint32_t hash_val, hash_type;
846                         uint8_t pr;
847
848                         pr = inp->inp_socket->so_proto->pr_protocol;
849                         /*
850                          * Calculate an appropriate RSS hash for UDP and
851                          * UDP Lite.
852                          *
853                          * The called function will take care of figuring out
854                          * whether a 2-tuple or 4-tuple hash is required based
855                          * on the currently configured scheme.
856                          *
857                          * Later later on connected socket values should be
858                          * cached in the inpcb and reused, rather than constantly
859                          * re-calculating it.
860                          *
861                          * UDP Lite is a different protocol number and will
862                          * likely end up being hashed as a 2-tuple until
863                          * RSS / NICs grow UDP Lite protocol awareness.
864                          */
865                         if (rss_proto_software_hash_v6(faddr, laddr, fport,
866                             inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
867                                 m->m_pkthdr.flowid = hash_val;
868                                 M_HASHTYPE_SET(m, hash_type);
869                         }
870                 }
871 #endif
872                 flags = 0;
873 #ifdef  RSS
874                 /*
875                  * Don't override with the inp cached flowid.
876                  *
877                  * Until the whole UDP path is vetted, it may actually
878                  * be incorrect.
879                  */
880                 flags |= IP_NODEFAULTFLOWID;
881 #endif
882
883                 UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
884                 UDPSTAT_INC(udps_opackets);
885                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
886                     NULL, inp);
887                 break;
888         case AF_INET:
889                 error = EAFNOSUPPORT;
890                 goto release;
891         }
892         goto releaseopt;
893
894 release:
895         m_freem(m);
896
897 releaseopt:
898         if (control) {
899                 ip6_clearpktopts(&opt, -1);
900                 m_freem(control);
901         }
902         return (error);
903 }
904
905 static void
906 udp6_abort(struct socket *so)
907 {
908         struct inpcb *inp;
909         struct inpcbinfo *pcbinfo;
910
911         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
912         inp = sotoinpcb(so);
913         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
914
915         INP_WLOCK(inp);
916 #ifdef INET
917         if (inp->inp_vflag & INP_IPV4) {
918                 struct pr_usrreqs *pru;
919                 uint8_t nxt;
920
921                 nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
922                     IPPROTO_UDP : IPPROTO_UDPLITE;
923                 INP_WUNLOCK(inp);
924                 pru = inetsw[ip_protox[nxt]].pr_usrreqs;
925                 (*pru->pru_abort)(so);
926                 return;
927         }
928 #endif
929
930         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
931                 INP_HASH_WLOCK(pcbinfo);
932                 in6_pcbdisconnect(inp);
933                 inp->in6p_laddr = in6addr_any;
934                 INP_HASH_WUNLOCK(pcbinfo);
935                 soisdisconnected(so);
936         }
937         INP_WUNLOCK(inp);
938 }
939
940 static int
941 udp6_attach(struct socket *so, int proto, struct thread *td)
942 {
943         struct inpcb *inp;
944         struct inpcbinfo *pcbinfo;
945         int error;
946
947         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
948         inp = sotoinpcb(so);
949         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
950
951         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
952                 error = soreserve(so, udp_sendspace, udp_recvspace);
953                 if (error)
954                         return (error);
955         }
956         INP_INFO_WLOCK(pcbinfo);
957         error = in_pcballoc(so, pcbinfo);
958         if (error) {
959                 INP_INFO_WUNLOCK(pcbinfo);
960                 return (error);
961         }
962         inp = (struct inpcb *)so->so_pcb;
963         inp->inp_vflag |= INP_IPV6;
964         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
965                 inp->inp_vflag |= INP_IPV4;
966         inp->in6p_hops = -1;    /* use kernel default */
967         inp->in6p_cksum = -1;   /* just to be sure */
968         /*
969          * XXX: ugly!!
970          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
971          * because the socket may be bound to an IPv6 wildcard address,
972          * which may match an IPv4-mapped IPv6 address.
973          */
974         inp->inp_ip_ttl = V_ip_defttl;
975
976         error = udp_newudpcb(inp);
977         if (error) {
978                 in_pcbdetach(inp);
979                 in_pcbfree(inp);
980                 INP_INFO_WUNLOCK(pcbinfo);
981                 return (error);
982         }
983         INP_WUNLOCK(inp);
984         INP_INFO_WUNLOCK(pcbinfo);
985         return (0);
986 }
987
988 static int
989 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
990 {
991         struct inpcb *inp;
992         struct inpcbinfo *pcbinfo;
993         int error;
994
995         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
996         inp = sotoinpcb(so);
997         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
998
999         INP_WLOCK(inp);
1000         INP_HASH_WLOCK(pcbinfo);
1001         inp->inp_vflag &= ~INP_IPV4;
1002         inp->inp_vflag |= INP_IPV6;
1003         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1004                 struct sockaddr_in6 *sin6_p;
1005
1006                 sin6_p = (struct sockaddr_in6 *)nam;
1007
1008                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
1009                         inp->inp_vflag |= INP_IPV4;
1010 #ifdef INET
1011                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
1012                         struct sockaddr_in sin;
1013
1014                         in6_sin6_2_sin(&sin, sin6_p);
1015                         inp->inp_vflag |= INP_IPV4;
1016                         inp->inp_vflag &= ~INP_IPV6;
1017                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
1018                             td->td_ucred);
1019                         goto out;
1020                 }
1021 #endif
1022         }
1023
1024         error = in6_pcbbind(inp, nam, td->td_ucred);
1025 #ifdef INET
1026 out:
1027 #endif
1028         INP_HASH_WUNLOCK(pcbinfo);
1029         INP_WUNLOCK(inp);
1030         return (error);
1031 }
1032
1033 static void
1034 udp6_close(struct socket *so)
1035 {
1036         struct inpcb *inp;
1037         struct inpcbinfo *pcbinfo;
1038
1039         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1040         inp = sotoinpcb(so);
1041         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
1042
1043         INP_WLOCK(inp);
1044 #ifdef INET
1045         if (inp->inp_vflag & INP_IPV4) {
1046                 struct pr_usrreqs *pru;
1047                 uint8_t nxt;
1048
1049                 nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1050                     IPPROTO_UDP : IPPROTO_UDPLITE;
1051                 INP_WUNLOCK(inp);
1052                 pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1053                 (*pru->pru_disconnect)(so);
1054                 return;
1055         }
1056 #endif
1057         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1058                 INP_HASH_WLOCK(pcbinfo);
1059                 in6_pcbdisconnect(inp);
1060                 inp->in6p_laddr = in6addr_any;
1061                 INP_HASH_WUNLOCK(pcbinfo);
1062                 soisdisconnected(so);
1063         }
1064         INP_WUNLOCK(inp);
1065 }
1066
1067 static int
1068 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1069 {
1070         struct inpcb *inp;
1071         struct inpcbinfo *pcbinfo;
1072         struct sockaddr_in6 *sin6;
1073         int error;
1074
1075         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1076         inp = sotoinpcb(so);
1077         sin6 = (struct sockaddr_in6 *)nam;
1078         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1079
1080         /*
1081          * XXXRW: Need to clarify locking of v4/v6 flags.
1082          */
1083         INP_WLOCK(inp);
1084 #ifdef INET
1085         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1086                 struct sockaddr_in sin;
1087
1088                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1089                         error = EINVAL;
1090                         goto out;
1091                 }
1092                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1093                         error = EISCONN;
1094                         goto out;
1095                 }
1096                 in6_sin6_2_sin(&sin, sin6);
1097                 inp->inp_vflag |= INP_IPV4;
1098                 inp->inp_vflag &= ~INP_IPV6;
1099                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1100                 if (error != 0)
1101                         goto out;
1102                 INP_HASH_WLOCK(pcbinfo);
1103                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1104                     td->td_ucred);
1105                 INP_HASH_WUNLOCK(pcbinfo);
1106                 if (error == 0)
1107                         soisconnected(so);
1108                 goto out;
1109         }
1110 #endif
1111         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1112                 error = EISCONN;
1113                 goto out;
1114         }
1115         inp->inp_vflag &= ~INP_IPV4;
1116         inp->inp_vflag |= INP_IPV6;
1117         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1118         if (error != 0)
1119                 goto out;
1120         INP_HASH_WLOCK(pcbinfo);
1121         error = in6_pcbconnect(inp, nam, td->td_ucred);
1122         INP_HASH_WUNLOCK(pcbinfo);
1123         if (error == 0)
1124                 soisconnected(so);
1125 out:
1126         INP_WUNLOCK(inp);
1127         return (error);
1128 }
1129
1130 static void
1131 udp6_detach(struct socket *so)
1132 {
1133         struct inpcb *inp;
1134         struct inpcbinfo *pcbinfo;
1135         struct udpcb *up;
1136
1137         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1138         inp = sotoinpcb(so);
1139         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1140
1141         INP_INFO_WLOCK(pcbinfo);
1142         INP_WLOCK(inp);
1143         up = intoudpcb(inp);
1144         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1145         in_pcbdetach(inp);
1146         in_pcbfree(inp);
1147         INP_INFO_WUNLOCK(pcbinfo);
1148         udp_discardcb(up);
1149 }
1150
1151 static int
1152 udp6_disconnect(struct socket *so)
1153 {
1154         struct inpcb *inp;
1155         struct inpcbinfo *pcbinfo;
1156         int error;
1157
1158         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1159         inp = sotoinpcb(so);
1160         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1161
1162         INP_WLOCK(inp);
1163 #ifdef INET
1164         if (inp->inp_vflag & INP_IPV4) {
1165                 struct pr_usrreqs *pru;
1166                 uint8_t nxt;
1167
1168                 nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
1169                     IPPROTO_UDP : IPPROTO_UDPLITE;
1170                 INP_WUNLOCK(inp);
1171                 pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1172                 (void)(*pru->pru_disconnect)(so);
1173                 return (0);
1174         }
1175 #endif
1176
1177         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1178                 error = ENOTCONN;
1179                 goto out;
1180         }
1181
1182         INP_HASH_WLOCK(pcbinfo);
1183         in6_pcbdisconnect(inp);
1184         inp->in6p_laddr = in6addr_any;
1185         INP_HASH_WUNLOCK(pcbinfo);
1186         SOCK_LOCK(so);
1187         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1188         SOCK_UNLOCK(so);
1189 out:
1190         INP_WUNLOCK(inp);
1191         return (0);
1192 }
1193
1194 static int
1195 udp6_send(struct socket *so, int flags, struct mbuf *m,
1196     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1197 {
1198         struct inpcb *inp;
1199         struct inpcbinfo *pcbinfo;
1200         int error = 0;
1201
1202         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1203         inp = sotoinpcb(so);
1204         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1205
1206         INP_WLOCK(inp);
1207         if (addr) {
1208                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1209                         error = EINVAL;
1210                         goto bad;
1211                 }
1212                 if (addr->sa_family != AF_INET6) {
1213                         error = EAFNOSUPPORT;
1214                         goto bad;
1215                 }
1216         }
1217
1218 #ifdef INET
1219         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1220                 int hasv4addr;
1221                 struct sockaddr_in6 *sin6 = 0;
1222
1223                 if (addr == 0)
1224                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1225                 else {
1226                         sin6 = (struct sockaddr_in6 *)addr;
1227                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1228                             ? 1 : 0;
1229                 }
1230                 if (hasv4addr) {
1231                         struct pr_usrreqs *pru;
1232                         uint8_t nxt;
1233
1234                         nxt = (inp->inp_socket->so_proto->pr_protocol ==
1235                             IPPROTO_UDP) ? IPPROTO_UDP : IPPROTO_UDPLITE;
1236                         /*
1237                          * XXXRW: We release UDP-layer locks before calling
1238                          * udp_send() in order to avoid recursion.  However,
1239                          * this does mean there is a short window where inp's
1240                          * fields are unstable.  Could this lead to a
1241                          * potential race in which the factors causing us to
1242                          * select the UDPv4 output routine are invalidated?
1243                          */
1244                         INP_WUNLOCK(inp);
1245                         if (sin6)
1246                                 in6_sin6_2_sin_in_sock(addr);
1247                         pru = inetsw[ip_protox[nxt]].pr_usrreqs;
1248                         /* addr will just be freed in sendit(). */
1249                         return ((*pru->pru_send)(so, flags, m, addr, control,
1250                             td));
1251                 }
1252         }
1253 #endif
1254 #ifdef MAC
1255         mac_inpcb_create_mbuf(inp, m);
1256 #endif
1257         INP_HASH_WLOCK(pcbinfo);
1258         error = udp6_output(inp, m, addr, control, td);
1259         INP_HASH_WUNLOCK(pcbinfo);
1260         INP_WUNLOCK(inp);
1261         return (error);
1262
1263 bad:
1264         INP_WUNLOCK(inp);
1265         m_freem(m);
1266         return (error);
1267 }
1268
1269 struct pr_usrreqs udp6_usrreqs = {
1270         .pru_abort =            udp6_abort,
1271         .pru_attach =           udp6_attach,
1272         .pru_bind =             udp6_bind,
1273         .pru_connect =          udp6_connect,
1274         .pru_control =          in6_control,
1275         .pru_detach =           udp6_detach,
1276         .pru_disconnect =       udp6_disconnect,
1277         .pru_peeraddr =         in6_mapped_peeraddr,
1278         .pru_send =             udp6_send,
1279         .pru_shutdown =         udp_shutdown,
1280         .pru_sockaddr =         in6_mapped_sockaddr,
1281         .pru_soreceive =        soreceive_dgram,
1282         .pru_sosend =           sosend_dgram,
1283         .pru_sosetlabel =       in_pcbsosetlabel,
1284         .pru_close =            udp6_close
1285 };