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MFC r310593,r310599:
[FreeBSD/FreeBSD.git] / sys / netinet / udp_usrreq.c
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3  *      The Regents of the University of California.
4  * Copyright (c) 2008 Robert N. M. Watson
5  * Copyright (c) 2010-2011 Juniper Networks, Inc.
6  * Copyright (c) 2014 Kevin Lo
7  * All rights reserved.
8  *
9  * Portions of this software were developed by Robert N. M. Watson under
10  * contract to Juniper Networks, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
37  */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include "opt_inet.h"
43 #include "opt_inet6.h"
44 #include "opt_ipsec.h"
45 #include "opt_rss.h"
46
47 #include <sys/param.h>
48 #include <sys/domain.h>
49 #include <sys/eventhandler.h>
50 #include <sys/jail.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mbuf.h>
55 #include <sys/priv.h>
56 #include <sys/proc.h>
57 #include <sys/protosw.h>
58 #include <sys/sdt.h>
59 #include <sys/signalvar.h>
60 #include <sys/socket.h>
61 #include <sys/socketvar.h>
62 #include <sys/sx.h>
63 #include <sys/sysctl.h>
64 #include <sys/syslog.h>
65 #include <sys/systm.h>
66
67 #include <vm/uma.h>
68
69 #include <net/if.h>
70 #include <net/if_var.h>
71 #include <net/route.h>
72 #include <net/rss_config.h>
73
74 #include <netinet/in.h>
75 #include <netinet/in_kdtrace.h>
76 #include <netinet/in_pcb.h>
77 #include <netinet/in_systm.h>
78 #include <netinet/in_var.h>
79 #include <netinet/ip.h>
80 #ifdef INET6
81 #include <netinet/ip6.h>
82 #endif
83 #include <netinet/ip_icmp.h>
84 #include <netinet/icmp_var.h>
85 #include <netinet/ip_var.h>
86 #include <netinet/ip_options.h>
87 #ifdef INET6
88 #include <netinet6/ip6_var.h>
89 #endif
90 #include <netinet/udp.h>
91 #include <netinet/udp_var.h>
92 #include <netinet/udplite.h>
93 #include <netinet/in_rss.h>
94
95 #include <netipsec/ipsec_support.h>
96
97 #include <machine/in_cksum.h>
98
99 #include <security/mac/mac_framework.h>
100
101 /*
102  * UDP and UDP-Lite protocols implementation.
103  * Per RFC 768, August, 1980.
104  * Per RFC 3828, July, 2004.
105  */
106
107 /*
108  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
109  * removes the only data integrity mechanism for packets and malformed
110  * packets that would otherwise be discarded due to bad checksums, and may
111  * cause problems (especially for NFS data blocks).
112  */
113 VNET_DEFINE(int, udp_cksum) = 1;
114 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
115     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
116
117 int     udp_log_in_vain = 0;
118 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
119     &udp_log_in_vain, 0, "Log all incoming UDP packets");
120
121 VNET_DEFINE(int, udp_blackhole) = 0;
122 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
123     &VNET_NAME(udp_blackhole), 0,
124     "Do not send port unreachables for refused connects");
125
126 u_long  udp_sendspace = 9216;           /* really max datagram size */
127 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
128     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
129
130 u_long  udp_recvspace = 40 * (1024 +
131 #ifdef INET6
132                                       sizeof(struct sockaddr_in6)
133 #else
134                                       sizeof(struct sockaddr_in)
135 #endif
136                                       );        /* 40 1K datagrams */
137
138 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
139     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
140
141 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
142 VNET_DEFINE(struct inpcbinfo, udbinfo);
143 VNET_DEFINE(struct inpcbhead, ulitecb);
144 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
145 static VNET_DEFINE(uma_zone_t, udpcb_zone);
146 #define V_udpcb_zone                    VNET(udpcb_zone)
147
148 #ifndef UDBHASHSIZE
149 #define UDBHASHSIZE     128
150 #endif
151
152 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);          /* from udp_var.h */
153 VNET_PCPUSTAT_SYSINIT(udpstat);
154 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
155     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
156
157 #ifdef VIMAGE
158 VNET_PCPUSTAT_SYSUNINIT(udpstat);
159 #endif /* VIMAGE */
160 #ifdef INET
161 static void     udp_detach(struct socket *so);
162 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
163                     struct mbuf *, struct thread *);
164 #endif
165
166 static void
167 udp_zone_change(void *tag)
168 {
169
170         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
171         uma_zone_set_max(V_udpcb_zone, maxsockets);
172 }
173
174 static int
175 udp_inpcb_init(void *mem, int size, int flags)
176 {
177         struct inpcb *inp;
178
179         inp = mem;
180         INP_LOCK_INIT(inp, "inp", "udpinp");
181         return (0);
182 }
183
184 static int
185 udplite_inpcb_init(void *mem, int size, int flags)
186 {
187         struct inpcb *inp;
188
189         inp = mem;
190         INP_LOCK_INIT(inp, "inp", "udpliteinp");
191         return (0);
192 }
193
194 void
195 udp_init(void)
196 {
197
198         /*
199          * For now default to 2-tuple UDP hashing - until the fragment
200          * reassembly code can also update the flowid.
201          *
202          * Once we can calculate the flowid that way and re-establish
203          * a 4-tuple, flip this to 4-tuple.
204          */
205         in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
206             "udp_inpcb", udp_inpcb_init, NULL, 0,
207             IPI_HASHFIELDS_2TUPLE);
208         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
209             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
210         uma_zone_set_max(V_udpcb_zone, maxsockets);
211         uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
212         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
213             EVENTHANDLER_PRI_ANY);
214 }
215
216 void
217 udplite_init(void)
218 {
219
220         in_pcbinfo_init(&V_ulitecbinfo, "udplite", &V_ulitecb, UDBHASHSIZE,
221             UDBHASHSIZE, "udplite_inpcb", udplite_inpcb_init, NULL,
222             0, IPI_HASHFIELDS_2TUPLE);
223 }
224
225 /*
226  * Kernel module interface for updating udpstat.  The argument is an index
227  * into udpstat treated as an array of u_long.  While this encodes the
228  * general layout of udpstat into the caller, it doesn't encode its location,
229  * so that future changes to add, for example, per-CPU stats support won't
230  * cause binary compatibility problems for kernel modules.
231  */
232 void
233 kmod_udpstat_inc(int statnum)
234 {
235
236         counter_u64_add(VNET(udpstat)[statnum], 1);
237 }
238
239 int
240 udp_newudpcb(struct inpcb *inp)
241 {
242         struct udpcb *up;
243
244         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
245         if (up == NULL)
246                 return (ENOBUFS);
247         inp->inp_ppcb = up;
248         return (0);
249 }
250
251 void
252 udp_discardcb(struct udpcb *up)
253 {
254
255         uma_zfree(V_udpcb_zone, up);
256 }
257
258 #ifdef VIMAGE
259 static void
260 udp_destroy(void *unused __unused)
261 {
262
263         in_pcbinfo_destroy(&V_udbinfo);
264         uma_zdestroy(V_udpcb_zone);
265 }
266 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
267
268 static void
269 udplite_destroy(void *unused __unused)
270 {
271
272         in_pcbinfo_destroy(&V_ulitecbinfo);
273 }
274 VNET_SYSUNINIT(udplite, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udplite_destroy,
275     NULL);
276 #endif
277
278 #ifdef INET
279 /*
280  * Subroutine of udp_input(), which appends the provided mbuf chain to the
281  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
282  * contains the source address.  If the socket ends up being an IPv6 socket,
283  * udp_append() will convert to a sockaddr_in6 before passing the address
284  * into the socket code.
285  *
286  * In the normal case udp_append() will return 0, indicating that you
287  * must unlock the inp. However if a tunneling protocol is in place we increment
288  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
289  * then decrement the reference count. If the inp_rele returns 1, indicating the
290  * inp is gone, we return that to the caller to tell them *not* to unlock
291  * the inp. In the case of multi-cast this will cause the distribution
292  * to stop (though most tunneling protocols known currently do *not* use
293  * multicast).
294  */
295 static int
296 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
297     struct sockaddr_in *udp_in)
298 {
299         struct sockaddr *append_sa;
300         struct socket *so;
301         struct mbuf *opts = NULL;
302 #ifdef INET6
303         struct sockaddr_in6 udp_in6;
304 #endif
305         struct udpcb *up;
306
307         INP_LOCK_ASSERT(inp);
308
309         /*
310          * Engage the tunneling protocol.
311          */
312         up = intoudpcb(inp);
313         if (up->u_tun_func != NULL) {
314                 in_pcbref(inp);
315                 INP_RUNLOCK(inp);
316                 (*up->u_tun_func)(n, off, inp, (struct sockaddr *)udp_in,
317                     up->u_tun_ctx);
318                 INP_RLOCK(inp);
319                 return (in_pcbrele_rlocked(inp));
320         }
321
322         off += sizeof(struct udphdr);
323
324 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
325         /* Check AH/ESP integrity. */
326         if (IPSEC_ENABLED(ipv4) &&
327             IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
328                 m_freem(n);
329                 return (0);
330         }
331         if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
332                 if (IPSEC_ENABLED(ipv4) &&
333                     UDPENCAP_INPUT(n, off, AF_INET) != 0)
334                         return (0);     /* Consumed. */
335         }
336 #endif /* IPSEC */
337 #ifdef MAC
338         if (mac_inpcb_check_deliver(inp, n) != 0) {
339                 m_freem(n);
340                 return (0);
341         }
342 #endif /* MAC */
343         if (inp->inp_flags & INP_CONTROLOPTS ||
344             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
345 #ifdef INET6
346                 if (inp->inp_vflag & INP_IPV6)
347                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
348                 else
349 #endif /* INET6 */
350                         ip_savecontrol(inp, &opts, ip, n);
351         }
352 #ifdef INET6
353         if (inp->inp_vflag & INP_IPV6) {
354                 bzero(&udp_in6, sizeof(udp_in6));
355                 udp_in6.sin6_len = sizeof(udp_in6);
356                 udp_in6.sin6_family = AF_INET6;
357                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
358                 append_sa = (struct sockaddr *)&udp_in6;
359         } else
360 #endif /* INET6 */
361                 append_sa = (struct sockaddr *)udp_in;
362         m_adj(n, off);
363
364         so = inp->inp_socket;
365         SOCKBUF_LOCK(&so->so_rcv);
366         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
367                 SOCKBUF_UNLOCK(&so->so_rcv);
368                 m_freem(n);
369                 if (opts)
370                         m_freem(opts);
371                 UDPSTAT_INC(udps_fullsock);
372         } else
373                 sorwakeup_locked(so);
374         return (0);
375 }
376
377 int
378 udp_input(struct mbuf **mp, int *offp, int proto)
379 {
380         struct ip *ip;
381         struct udphdr *uh;
382         struct ifnet *ifp;
383         struct inpcb *inp;
384         uint16_t len, ip_len;
385         struct inpcbinfo *pcbinfo;
386         struct ip save_ip;
387         struct sockaddr_in udp_in;
388         struct mbuf *m;
389         struct m_tag *fwd_tag;
390         int cscov_partial, iphlen;
391
392         m = *mp;
393         iphlen = *offp;
394         ifp = m->m_pkthdr.rcvif;
395         *mp = NULL;
396         UDPSTAT_INC(udps_ipackets);
397
398         /*
399          * Strip IP options, if any; should skip this, make available to
400          * user, and use on returned packets, but we don't yet have a way to
401          * check the checksum with options still present.
402          */
403         if (iphlen > sizeof (struct ip)) {
404                 ip_stripoptions(m);
405                 iphlen = sizeof(struct ip);
406         }
407
408         /*
409          * Get IP and UDP header together in first mbuf.
410          */
411         ip = mtod(m, struct ip *);
412         if (m->m_len < iphlen + sizeof(struct udphdr)) {
413                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
414                         UDPSTAT_INC(udps_hdrops);
415                         return (IPPROTO_DONE);
416                 }
417                 ip = mtod(m, struct ip *);
418         }
419         uh = (struct udphdr *)((caddr_t)ip + iphlen);
420         cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
421
422         /*
423          * Destination port of 0 is illegal, based on RFC768.
424          */
425         if (uh->uh_dport == 0)
426                 goto badunlocked;
427
428         /*
429          * Construct sockaddr format source address.  Stuff source address
430          * and datagram in user buffer.
431          */
432         bzero(&udp_in, sizeof(udp_in));
433         udp_in.sin_len = sizeof(udp_in);
434         udp_in.sin_family = AF_INET;
435         udp_in.sin_port = uh->uh_sport;
436         udp_in.sin_addr = ip->ip_src;
437
438         /*
439          * Make mbuf data length reflect UDP length.  If not enough data to
440          * reflect UDP length, drop.
441          */
442         len = ntohs((u_short)uh->uh_ulen);
443         ip_len = ntohs(ip->ip_len) - iphlen;
444         if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
445                 /* Zero means checksum over the complete packet. */
446                 if (len == 0)
447                         len = ip_len;
448                 cscov_partial = 0;
449         }
450         if (ip_len != len) {
451                 if (len > ip_len || len < sizeof(struct udphdr)) {
452                         UDPSTAT_INC(udps_badlen);
453                         goto badunlocked;
454                 }
455                 if (proto == IPPROTO_UDP)
456                         m_adj(m, len - ip_len);
457         }
458
459         /*
460          * Save a copy of the IP header in case we want restore it for
461          * sending an ICMP error message in response.
462          */
463         if (!V_udp_blackhole)
464                 save_ip = *ip;
465         else
466                 memset(&save_ip, 0, sizeof(save_ip));
467
468         /*
469          * Checksum extended UDP header and data.
470          */
471         if (uh->uh_sum) {
472                 u_short uh_sum;
473
474                 if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
475                     !cscov_partial) {
476                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
477                                 uh_sum = m->m_pkthdr.csum_data;
478                         else
479                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
480                                     ip->ip_dst.s_addr, htonl((u_short)len +
481                                     m->m_pkthdr.csum_data + proto));
482                         uh_sum ^= 0xffff;
483                 } else {
484                         char b[9];
485
486                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
487                         bzero(((struct ipovly *)ip)->ih_x1, 9);
488                         ((struct ipovly *)ip)->ih_len = (proto == IPPROTO_UDP) ?
489                             uh->uh_ulen : htons(ip_len);
490                         uh_sum = in_cksum(m, len + sizeof (struct ip));
491                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
492                 }
493                 if (uh_sum) {
494                         UDPSTAT_INC(udps_badsum);
495                         m_freem(m);
496                         return (IPPROTO_DONE);
497                 }
498         } else {
499                 if (proto == IPPROTO_UDP) {
500                         UDPSTAT_INC(udps_nosum);
501                 } else {
502                         /* UDPLite requires a checksum */
503                         /* XXX: What is the right UDPLite MIB counter here? */
504                         m_freem(m);
505                         return (IPPROTO_DONE);
506                 }
507         }
508
509         pcbinfo = udp_get_inpcbinfo(proto);
510         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
511             in_broadcast(ip->ip_dst, ifp)) {
512                 struct inpcb *last;
513                 struct inpcbhead *pcblist;
514                 struct ip_moptions *imo;
515
516                 INP_INFO_RLOCK(pcbinfo);
517                 pcblist = udp_get_pcblist(proto);
518                 last = NULL;
519                 LIST_FOREACH(inp, pcblist, inp_list) {
520                         if (inp->inp_lport != uh->uh_dport)
521                                 continue;
522 #ifdef INET6
523                         if ((inp->inp_vflag & INP_IPV4) == 0)
524                                 continue;
525 #endif
526                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
527                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
528                                 continue;
529                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
530                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
531                                 continue;
532                         if (inp->inp_fport != 0 &&
533                             inp->inp_fport != uh->uh_sport)
534                                 continue;
535
536                         INP_RLOCK(inp);
537
538                         /*
539                          * XXXRW: Because we weren't holding either the inpcb
540                          * or the hash lock when we checked for a match
541                          * before, we should probably recheck now that the
542                          * inpcb lock is held.
543                          */
544
545                         /*
546                          * Handle socket delivery policy for any-source
547                          * and source-specific multicast. [RFC3678]
548                          */
549                         imo = inp->inp_moptions;
550                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
551                                 struct sockaddr_in       group;
552                                 int                      blocked;
553                                 if (imo == NULL) {
554                                         INP_RUNLOCK(inp);
555                                         continue;
556                                 }
557                                 bzero(&group, sizeof(struct sockaddr_in));
558                                 group.sin_len = sizeof(struct sockaddr_in);
559                                 group.sin_family = AF_INET;
560                                 group.sin_addr = ip->ip_dst;
561
562                                 blocked = imo_multi_filter(imo, ifp,
563                                         (struct sockaddr *)&group,
564                                         (struct sockaddr *)&udp_in);
565                                 if (blocked != MCAST_PASS) {
566                                         if (blocked == MCAST_NOTGMEMBER)
567                                                 IPSTAT_INC(ips_notmember);
568                                         if (blocked == MCAST_NOTSMEMBER ||
569                                             blocked == MCAST_MUTED)
570                                                 UDPSTAT_INC(udps_filtermcast);
571                                         INP_RUNLOCK(inp);
572                                         continue;
573                                 }
574                         }
575                         if (last != NULL) {
576                                 struct mbuf *n;
577
578                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
579                                         UDP_PROBE(receive, NULL, last, ip,
580                                             last, uh);
581                                         if (udp_append(last, ip, n, iphlen,
582                                                 &udp_in)) {
583                                                 goto inp_lost;
584                                         }
585                                 }
586                                 INP_RUNLOCK(last);
587                         }
588                         last = inp;
589                         /*
590                          * Don't look for additional matches if this one does
591                          * not have either the SO_REUSEPORT or SO_REUSEADDR
592                          * socket options set.  This heuristic avoids
593                          * searching through all pcbs in the common case of a
594                          * non-shared port.  It assumes that an application
595                          * will never clear these options after setting them.
596                          */
597                         if ((last->inp_socket->so_options &
598                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
599                                 break;
600                 }
601
602                 if (last == NULL) {
603                         /*
604                          * No matching pcb found; discard datagram.  (No need
605                          * to send an ICMP Port Unreachable for a broadcast
606                          * or multicast datgram.)
607                          */
608                         UDPSTAT_INC(udps_noportbcast);
609                         if (inp)
610                                 INP_RUNLOCK(inp);
611                         INP_INFO_RUNLOCK(pcbinfo);
612                         goto badunlocked;
613                 }
614                 UDP_PROBE(receive, NULL, last, ip, last, uh);
615                 if (udp_append(last, ip, m, iphlen, &udp_in) == 0) 
616                         INP_RUNLOCK(last);
617         inp_lost:
618                 INP_INFO_RUNLOCK(pcbinfo);
619                 return (IPPROTO_DONE);
620         }
621
622         /*
623          * Locate pcb for datagram.
624          */
625
626         /*
627          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
628          */
629         if ((m->m_flags & M_IP_NEXTHOP) &&
630             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
631                 struct sockaddr_in *next_hop;
632
633                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
634
635                 /*
636                  * Transparently forwarded. Pretend to be the destination.
637                  * Already got one like this?
638                  */
639                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
640                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
641                 if (!inp) {
642                         /*
643                          * It's new.  Try to find the ambushing socket.
644                          * Because we've rewritten the destination address,
645                          * any hardware-generated hash is ignored.
646                          */
647                         inp = in_pcblookup(pcbinfo, ip->ip_src,
648                             uh->uh_sport, next_hop->sin_addr,
649                             next_hop->sin_port ? htons(next_hop->sin_port) :
650                             uh->uh_dport, INPLOOKUP_WILDCARD |
651                             INPLOOKUP_RLOCKPCB, ifp);
652                 }
653                 /* Remove the tag from the packet. We don't need it anymore. */
654                 m_tag_delete(m, fwd_tag);
655                 m->m_flags &= ~M_IP_NEXTHOP;
656         } else
657                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
658                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
659                     INPLOOKUP_RLOCKPCB, ifp, m);
660         if (inp == NULL) {
661                 if (udp_log_in_vain) {
662                         char src[INET_ADDRSTRLEN];
663                         char dst[INET_ADDRSTRLEN];
664
665                         log(LOG_INFO,
666                             "Connection attempt to UDP %s:%d from %s:%d\n",
667                             inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
668                             inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
669                 }
670                 UDPSTAT_INC(udps_noport);
671                 if (m->m_flags & (M_BCAST | M_MCAST)) {
672                         UDPSTAT_INC(udps_noportbcast);
673                         goto badunlocked;
674                 }
675                 if (V_udp_blackhole)
676                         goto badunlocked;
677                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
678                         goto badunlocked;
679                 *ip = save_ip;
680                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
681                 return (IPPROTO_DONE);
682         }
683
684         /*
685          * Check the minimum TTL for socket.
686          */
687         INP_RLOCK_ASSERT(inp);
688         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
689                 INP_RUNLOCK(inp);
690                 m_freem(m);
691                 return (IPPROTO_DONE);
692         }
693         if (cscov_partial) {
694                 struct udpcb *up;
695
696                 up = intoudpcb(inp);
697                 if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
698                         INP_RUNLOCK(inp);
699                         m_freem(m);
700                         return (IPPROTO_DONE);
701                 }
702         }
703
704         UDP_PROBE(receive, NULL, inp, ip, inp, uh);
705         if (udp_append(inp, ip, m, iphlen, &udp_in) == 0) 
706                 INP_RUNLOCK(inp);
707         return (IPPROTO_DONE);
708
709 badunlocked:
710         m_freem(m);
711         return (IPPROTO_DONE);
712 }
713 #endif /* INET */
714
715 /*
716  * Notify a udp user of an asynchronous error; just wake up so that they can
717  * collect error status.
718  */
719 struct inpcb *
720 udp_notify(struct inpcb *inp, int errno)
721 {
722
723         /*
724          * While udp_ctlinput() always calls udp_notify() with a read lock
725          * when invoking it directly, in_pcbnotifyall() currently uses write
726          * locks due to sharing code with TCP.  For now, accept either a read
727          * or a write lock, but a read lock is sufficient.
728          */
729         INP_LOCK_ASSERT(inp);
730         if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
731              errno == EHOSTDOWN) && inp->inp_route.ro_rt) {
732                 RTFREE(inp->inp_route.ro_rt);
733                 inp->inp_route.ro_rt = (struct rtentry *)NULL;
734         }
735
736         inp->inp_socket->so_error = errno;
737         sorwakeup(inp->inp_socket);
738         sowwakeup(inp->inp_socket);
739         return (inp);
740 }
741
742 #ifdef INET
743 static void
744 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
745     struct inpcbinfo *pcbinfo)
746 {
747         struct ip *ip = vip;
748         struct udphdr *uh;
749         struct in_addr faddr;
750         struct inpcb *inp;
751
752         faddr = ((struct sockaddr_in *)sa)->sin_addr;
753         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
754                 return;
755
756         if (PRC_IS_REDIRECT(cmd)) {
757                 /* signal EHOSTDOWN, as it flushes the cached route */
758                 in_pcbnotifyall(&V_udbinfo, faddr, EHOSTDOWN, udp_notify);
759                 return;
760         }
761
762         /*
763          * Hostdead is ugly because it goes linearly through all PCBs.
764          *
765          * XXX: We never get this from ICMP, otherwise it makes an excellent
766          * DoS attack on machines with many connections.
767          */
768         if (cmd == PRC_HOSTDEAD)
769                 ip = NULL;
770         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
771                 return;
772         if (ip != NULL) {
773                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
774                 inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
775                     ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
776                 if (inp != NULL) {
777                         INP_RLOCK_ASSERT(inp);
778                         if (inp->inp_socket != NULL) {
779                                 udp_notify(inp, inetctlerrmap[cmd]);
780                         }
781                         INP_RUNLOCK(inp);
782                 } else {
783                         inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
784                                            ip->ip_src, uh->uh_sport,
785                                            INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
786                         if (inp != NULL) {
787                                 struct udpcb *up;
788
789                                 up = intoudpcb(inp);
790                                 if (up->u_icmp_func != NULL) {
791                                         INP_RUNLOCK(inp);
792                                         (*up->u_icmp_func)(cmd, sa, vip, up->u_tun_ctx);
793                                 } else {
794                                         INP_RUNLOCK(inp);
795                                 }
796                         }
797                 }
798         } else
799                 in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
800                     udp_notify);
801 }
802 void
803 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
804 {
805
806         return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
807 }
808
809 void
810 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
811 {
812
813         return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
814 }
815 #endif /* INET */
816
817 static int
818 udp_pcblist(SYSCTL_HANDLER_ARGS)
819 {
820         int error, i, n;
821         struct inpcb *inp, **inp_list;
822         inp_gen_t gencnt;
823         struct xinpgen xig;
824
825         /*
826          * The process of preparing the PCB list is too time-consuming and
827          * resource-intensive to repeat twice on every request.
828          */
829         if (req->oldptr == 0) {
830                 n = V_udbinfo.ipi_count;
831                 n += imax(n / 8, 10);
832                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
833                 return (0);
834         }
835
836         if (req->newptr != 0)
837                 return (EPERM);
838
839         /*
840          * OK, now we're committed to doing something.
841          */
842         INP_INFO_RLOCK(&V_udbinfo);
843         gencnt = V_udbinfo.ipi_gencnt;
844         n = V_udbinfo.ipi_count;
845         INP_INFO_RUNLOCK(&V_udbinfo);
846
847         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
848                 + n * sizeof(struct xinpcb));
849         if (error != 0)
850                 return (error);
851
852         xig.xig_len = sizeof xig;
853         xig.xig_count = n;
854         xig.xig_gen = gencnt;
855         xig.xig_sogen = so_gencnt;
856         error = SYSCTL_OUT(req, &xig, sizeof xig);
857         if (error)
858                 return (error);
859
860         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
861         if (inp_list == NULL)
862                 return (ENOMEM);
863
864         INP_INFO_RLOCK(&V_udbinfo);
865         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
866              inp = LIST_NEXT(inp, inp_list)) {
867                 INP_WLOCK(inp);
868                 if (inp->inp_gencnt <= gencnt &&
869                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
870                         in_pcbref(inp);
871                         inp_list[i++] = inp;
872                 }
873                 INP_WUNLOCK(inp);
874         }
875         INP_INFO_RUNLOCK(&V_udbinfo);
876         n = i;
877
878         error = 0;
879         for (i = 0; i < n; i++) {
880                 inp = inp_list[i];
881                 INP_RLOCK(inp);
882                 if (inp->inp_gencnt <= gencnt) {
883                         struct xinpcb xi;
884
885                         bzero(&xi, sizeof(xi));
886                         xi.xi_len = sizeof xi;
887                         /* XXX should avoid extra copy */
888                         bcopy(inp, &xi.xi_inp, sizeof *inp);
889                         if (inp->inp_socket)
890                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
891                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
892                         INP_RUNLOCK(inp);
893                         error = SYSCTL_OUT(req, &xi, sizeof xi);
894                 } else
895                         INP_RUNLOCK(inp);
896         }
897         INP_INFO_WLOCK(&V_udbinfo);
898         for (i = 0; i < n; i++) {
899                 inp = inp_list[i];
900                 INP_RLOCK(inp);
901                 if (!in_pcbrele_rlocked(inp))
902                         INP_RUNLOCK(inp);
903         }
904         INP_INFO_WUNLOCK(&V_udbinfo);
905
906         if (!error) {
907                 /*
908                  * Give the user an updated idea of our state.  If the
909                  * generation differs from what we told her before, she knows
910                  * that something happened while we were processing this
911                  * request, and it might be necessary to retry.
912                  */
913                 INP_INFO_RLOCK(&V_udbinfo);
914                 xig.xig_gen = V_udbinfo.ipi_gencnt;
915                 xig.xig_sogen = so_gencnt;
916                 xig.xig_count = V_udbinfo.ipi_count;
917                 INP_INFO_RUNLOCK(&V_udbinfo);
918                 error = SYSCTL_OUT(req, &xig, sizeof xig);
919         }
920         free(inp_list, M_TEMP);
921         return (error);
922 }
923
924 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
925     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
926     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
927
928 #ifdef INET
929 static int
930 udp_getcred(SYSCTL_HANDLER_ARGS)
931 {
932         struct xucred xuc;
933         struct sockaddr_in addrs[2];
934         struct inpcb *inp;
935         int error;
936
937         error = priv_check(req->td, PRIV_NETINET_GETCRED);
938         if (error)
939                 return (error);
940         error = SYSCTL_IN(req, addrs, sizeof(addrs));
941         if (error)
942                 return (error);
943         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
944             addrs[0].sin_addr, addrs[0].sin_port,
945             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
946         if (inp != NULL) {
947                 INP_RLOCK_ASSERT(inp);
948                 if (inp->inp_socket == NULL)
949                         error = ENOENT;
950                 if (error == 0)
951                         error = cr_canseeinpcb(req->td->td_ucred, inp);
952                 if (error == 0)
953                         cru2x(inp->inp_cred, &xuc);
954                 INP_RUNLOCK(inp);
955         } else
956                 error = ENOENT;
957         if (error == 0)
958                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
959         return (error);
960 }
961
962 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
963     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
964     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
965 #endif /* INET */
966
967 int
968 udp_ctloutput(struct socket *so, struct sockopt *sopt)
969 {
970         struct inpcb *inp;
971         struct udpcb *up;
972         int isudplite, error, optval;
973
974         error = 0;
975         isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
976         inp = sotoinpcb(so);
977         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
978         INP_WLOCK(inp);
979         if (sopt->sopt_level != so->so_proto->pr_protocol) {
980 #ifdef INET6
981                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
982                         INP_WUNLOCK(inp);
983                         error = ip6_ctloutput(so, sopt);
984                 }
985 #endif
986 #if defined(INET) && defined(INET6)
987                 else
988 #endif
989 #ifdef INET
990                 {
991                         INP_WUNLOCK(inp);
992                         error = ip_ctloutput(so, sopt);
993                 }
994 #endif
995                 return (error);
996         }
997
998         switch (sopt->sopt_dir) {
999         case SOPT_SET:
1000                 switch (sopt->sopt_name) {
1001 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1002 #ifdef INET
1003                 case UDP_ENCAP:
1004                         if (!IPSEC_ENABLED(ipv4)) {
1005                                 INP_WUNLOCK(inp);
1006                                 return (ENOPROTOOPT);
1007                         }
1008                         error = UDPENCAP_PCBCTL(inp, sopt);
1009                         break;
1010 #endif /* INET */
1011 #endif /* IPSEC */
1012                 case UDPLITE_SEND_CSCOV:
1013                 case UDPLITE_RECV_CSCOV:
1014                         if (!isudplite) {
1015                                 INP_WUNLOCK(inp);
1016                                 error = ENOPROTOOPT;
1017                                 break;
1018                         }
1019                         INP_WUNLOCK(inp);
1020                         error = sooptcopyin(sopt, &optval, sizeof(optval),
1021                             sizeof(optval));
1022                         if (error != 0)
1023                                 break;
1024                         inp = sotoinpcb(so);
1025                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1026                         INP_WLOCK(inp);
1027                         up = intoudpcb(inp);
1028                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1029                         if ((optval != 0 && optval < 8) || (optval > 65535)) {
1030                                 INP_WUNLOCK(inp);
1031                                 error = EINVAL;
1032                                 break;
1033                         }
1034                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1035                                 up->u_txcslen = optval;
1036                         else
1037                                 up->u_rxcslen = optval;
1038                         INP_WUNLOCK(inp);
1039                         break;
1040                 default:
1041                         INP_WUNLOCK(inp);
1042                         error = ENOPROTOOPT;
1043                         break;
1044                 }
1045                 break;
1046         case SOPT_GET:
1047                 switch (sopt->sopt_name) {
1048 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1049 #ifdef INET
1050                 case UDP_ENCAP:
1051                         if (!IPSEC_ENABLED(ipv4)) {
1052                                 INP_WUNLOCK(inp);
1053                                 return (ENOPROTOOPT);
1054                         }
1055                         error = UDPENCAP_PCBCTL(inp, sopt);
1056                         break;
1057 #endif /* INET */
1058 #endif /* IPSEC */
1059                 case UDPLITE_SEND_CSCOV:
1060                 case UDPLITE_RECV_CSCOV:
1061                         if (!isudplite) {
1062                                 INP_WUNLOCK(inp);
1063                                 error = ENOPROTOOPT;
1064                                 break;
1065                         }
1066                         up = intoudpcb(inp);
1067                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1068                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1069                                 optval = up->u_txcslen;
1070                         else
1071                                 optval = up->u_rxcslen;
1072                         INP_WUNLOCK(inp);
1073                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1074                         break;
1075                 default:
1076                         INP_WUNLOCK(inp);
1077                         error = ENOPROTOOPT;
1078                         break;
1079                 }
1080                 break;
1081         }       
1082         return (error);
1083 }
1084
1085 #ifdef INET
1086 #define UH_WLOCKED      2
1087 #define UH_RLOCKED      1
1088 #define UH_UNLOCKED     0
1089 static int
1090 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
1091     struct mbuf *control, struct thread *td)
1092 {
1093         struct udpiphdr *ui;
1094         int len = m->m_pkthdr.len;
1095         struct in_addr faddr, laddr;
1096         struct cmsghdr *cm;
1097         struct inpcbinfo *pcbinfo;
1098         struct sockaddr_in *sin, src;
1099         int cscov_partial = 0;
1100         int error = 0;
1101         int ipflags;
1102         u_short fport, lport;
1103         int unlock_udbinfo, unlock_inp;
1104         u_char tos;
1105         uint8_t pr;
1106         uint16_t cscov = 0;
1107         uint32_t flowid = 0;
1108         uint8_t flowtype = M_HASHTYPE_NONE;
1109
1110         /*
1111          * udp_output() may need to temporarily bind or connect the current
1112          * inpcb.  As such, we don't know up front whether we will need the
1113          * pcbinfo lock or not.  Do any work to decide what is needed up
1114          * front before acquiring any locks.
1115          */
1116         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1117                 if (control)
1118                         m_freem(control);
1119                 m_freem(m);
1120                 return (EMSGSIZE);
1121         }
1122
1123         src.sin_family = 0;
1124         sin = (struct sockaddr_in *)addr;
1125         if (sin == NULL ||
1126             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1127                 INP_WLOCK(inp);
1128                 unlock_inp = UH_WLOCKED;
1129         } else {
1130                 INP_RLOCK(inp);
1131                 unlock_inp = UH_RLOCKED;
1132         }
1133         tos = inp->inp_ip_tos;
1134         if (control != NULL) {
1135                 /*
1136                  * XXX: Currently, we assume all the optional information is
1137                  * stored in a single mbuf.
1138                  */
1139                 if (control->m_next) {
1140                         if (unlock_inp == UH_WLOCKED)
1141                                 INP_WUNLOCK(inp);
1142                         else
1143                                 INP_RUNLOCK(inp);
1144                         m_freem(control);
1145                         m_freem(m);
1146                         return (EINVAL);
1147                 }
1148                 for (; control->m_len > 0;
1149                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
1150                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1151                         cm = mtod(control, struct cmsghdr *);
1152                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1153                             || cm->cmsg_len > control->m_len) {
1154                                 error = EINVAL;
1155                                 break;
1156                         }
1157                         if (cm->cmsg_level != IPPROTO_IP)
1158                                 continue;
1159
1160                         switch (cm->cmsg_type) {
1161                         case IP_SENDSRCADDR:
1162                                 if (cm->cmsg_len !=
1163                                     CMSG_LEN(sizeof(struct in_addr))) {
1164                                         error = EINVAL;
1165                                         break;
1166                                 }
1167                                 bzero(&src, sizeof(src));
1168                                 src.sin_family = AF_INET;
1169                                 src.sin_len = sizeof(src);
1170                                 src.sin_port = inp->inp_lport;
1171                                 src.sin_addr =
1172                                     *(struct in_addr *)CMSG_DATA(cm);
1173                                 break;
1174
1175                         case IP_TOS:
1176                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1177                                         error = EINVAL;
1178                                         break;
1179                                 }
1180                                 tos = *(u_char *)CMSG_DATA(cm);
1181                                 break;
1182
1183                         case IP_FLOWID:
1184                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1185                                         error = EINVAL;
1186                                         break;
1187                                 }
1188                                 flowid = *(uint32_t *) CMSG_DATA(cm);
1189                                 break;
1190
1191                         case IP_FLOWTYPE:
1192                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1193                                         error = EINVAL;
1194                                         break;
1195                                 }
1196                                 flowtype = *(uint32_t *) CMSG_DATA(cm);
1197                                 break;
1198
1199 #ifdef  RSS
1200                         case IP_RSSBUCKETID:
1201                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1202                                         error = EINVAL;
1203                                         break;
1204                                 }
1205                                 /* This is just a placeholder for now */
1206                                 break;
1207 #endif  /* RSS */
1208                         default:
1209                                 error = ENOPROTOOPT;
1210                                 break;
1211                         }
1212                         if (error)
1213                                 break;
1214                 }
1215                 m_freem(control);
1216         }
1217         if (error) {
1218                 if (unlock_inp == UH_WLOCKED)
1219                         INP_WUNLOCK(inp);
1220                 else
1221                         INP_RUNLOCK(inp);
1222                 m_freem(m);
1223                 return (error);
1224         }
1225
1226         /*
1227          * Depending on whether or not the application has bound or connected
1228          * the socket, we may have to do varying levels of work.  The optimal
1229          * case is for a connected UDP socket, as a global lock isn't
1230          * required at all.
1231          *
1232          * In order to decide which we need, we require stability of the
1233          * inpcb binding, which we ensure by acquiring a read lock on the
1234          * inpcb.  This doesn't strictly follow the lock order, so we play
1235          * the trylock and retry game; note that we may end up with more
1236          * conservative locks than required the second time around, so later
1237          * assertions have to accept that.  Further analysis of the number of
1238          * misses under contention is required.
1239          *
1240          * XXXRW: Check that hash locking update here is correct.
1241          */
1242         pr = inp->inp_socket->so_proto->pr_protocol;
1243         pcbinfo = udp_get_inpcbinfo(pr);
1244         sin = (struct sockaddr_in *)addr;
1245         if (sin != NULL &&
1246             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1247                 INP_HASH_WLOCK(pcbinfo);
1248                 unlock_udbinfo = UH_WLOCKED;
1249         } else if ((sin != NULL && (
1250             (sin->sin_addr.s_addr == INADDR_ANY) ||
1251             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1252             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1253             (inp->inp_lport == 0))) ||
1254             (src.sin_family == AF_INET)) {
1255                 INP_HASH_RLOCK(pcbinfo);
1256                 unlock_udbinfo = UH_RLOCKED;
1257         } else
1258                 unlock_udbinfo = UH_UNLOCKED;
1259
1260         /*
1261          * If the IP_SENDSRCADDR control message was specified, override the
1262          * source address for this datagram.  Its use is invalidated if the
1263          * address thus specified is incomplete or clobbers other inpcbs.
1264          */
1265         laddr = inp->inp_laddr;
1266         lport = inp->inp_lport;
1267         if (src.sin_family == AF_INET) {
1268                 INP_HASH_LOCK_ASSERT(pcbinfo);
1269                 if ((lport == 0) ||
1270                     (laddr.s_addr == INADDR_ANY &&
1271                      src.sin_addr.s_addr == INADDR_ANY)) {
1272                         error = EINVAL;
1273                         goto release;
1274                 }
1275                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1276                     &laddr.s_addr, &lport, td->td_ucred);
1277                 if (error)
1278                         goto release;
1279         }
1280
1281         /*
1282          * If a UDP socket has been connected, then a local address/port will
1283          * have been selected and bound.
1284          *
1285          * If a UDP socket has not been connected to, then an explicit
1286          * destination address must be used, in which case a local
1287          * address/port may not have been selected and bound.
1288          */
1289         if (sin != NULL) {
1290                 INP_LOCK_ASSERT(inp);
1291                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1292                         error = EISCONN;
1293                         goto release;
1294                 }
1295
1296                 /*
1297                  * Jail may rewrite the destination address, so let it do
1298                  * that before we use it.
1299                  */
1300                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1301                 if (error)
1302                         goto release;
1303
1304                 /*
1305                  * If a local address or port hasn't yet been selected, or if
1306                  * the destination address needs to be rewritten due to using
1307                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1308                  * to do the heavy lifting.  Once a port is selected, we
1309                  * commit the binding back to the socket; we also commit the
1310                  * binding of the address if in jail.
1311                  *
1312                  * If we already have a valid binding and we're not
1313                  * requesting a destination address rewrite, use a fast path.
1314                  */
1315                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1316                     inp->inp_lport == 0 ||
1317                     sin->sin_addr.s_addr == INADDR_ANY ||
1318                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1319                         INP_HASH_LOCK_ASSERT(pcbinfo);
1320                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1321                             &lport, &faddr.s_addr, &fport, NULL,
1322                             td->td_ucred);
1323                         if (error)
1324                                 goto release;
1325
1326                         /*
1327                          * XXXRW: Why not commit the port if the address is
1328                          * !INADDR_ANY?
1329                          */
1330                         /* Commit the local port if newly assigned. */
1331                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1332                             inp->inp_lport == 0) {
1333                                 INP_WLOCK_ASSERT(inp);
1334                                 INP_HASH_WLOCK_ASSERT(pcbinfo);
1335                                 /*
1336                                  * Remember addr if jailed, to prevent
1337                                  * rebinding.
1338                                  */
1339                                 if (prison_flag(td->td_ucred, PR_IP4))
1340                                         inp->inp_laddr = laddr;
1341                                 inp->inp_lport = lport;
1342                                 if (in_pcbinshash(inp) != 0) {
1343                                         inp->inp_lport = 0;
1344                                         error = EAGAIN;
1345                                         goto release;
1346                                 }
1347                                 inp->inp_flags |= INP_ANONPORT;
1348                         }
1349                 } else {
1350                         faddr = sin->sin_addr;
1351                         fport = sin->sin_port;
1352                 }
1353         } else {
1354                 INP_LOCK_ASSERT(inp);
1355                 faddr = inp->inp_faddr;
1356                 fport = inp->inp_fport;
1357                 if (faddr.s_addr == INADDR_ANY) {
1358                         error = ENOTCONN;
1359                         goto release;
1360                 }
1361         }
1362
1363         /*
1364          * Calculate data length and get a mbuf for UDP, IP, and possible
1365          * link-layer headers.  Immediate slide the data pointer back forward
1366          * since we won't use that space at this layer.
1367          */
1368         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1369         if (m == NULL) {
1370                 error = ENOBUFS;
1371                 goto release;
1372         }
1373         m->m_data += max_linkhdr;
1374         m->m_len -= max_linkhdr;
1375         m->m_pkthdr.len -= max_linkhdr;
1376
1377         /*
1378          * Fill in mbuf with extended UDP header and addresses and length put
1379          * into network format.
1380          */
1381         ui = mtod(m, struct udpiphdr *);
1382         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1383         ui->ui_pr = pr;
1384         ui->ui_src = laddr;
1385         ui->ui_dst = faddr;
1386         ui->ui_sport = lport;
1387         ui->ui_dport = fport;
1388         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1389         if (pr == IPPROTO_UDPLITE) {
1390                 struct udpcb *up;
1391                 uint16_t plen;
1392
1393                 up = intoudpcb(inp);
1394                 cscov = up->u_txcslen;
1395                 plen = (u_short)len + sizeof(struct udphdr);
1396                 if (cscov >= plen)
1397                         cscov = 0;
1398                 ui->ui_len = htons(plen);
1399                 ui->ui_ulen = htons(cscov);
1400                 /*
1401                  * For UDP-Lite, checksum coverage length of zero means
1402                  * the entire UDPLite packet is covered by the checksum.
1403                  */
1404                 cscov_partial = (cscov == 0) ? 0 : 1;
1405         } else
1406                 ui->ui_v = IPVERSION << 4;
1407
1408         /*
1409          * Set the Don't Fragment bit in the IP header.
1410          */
1411         if (inp->inp_flags & INP_DONTFRAG) {
1412                 struct ip *ip;
1413
1414                 ip = (struct ip *)&ui->ui_i;
1415                 ip->ip_off |= htons(IP_DF);
1416         }
1417
1418         ipflags = 0;
1419         if (inp->inp_socket->so_options & SO_DONTROUTE)
1420                 ipflags |= IP_ROUTETOIF;
1421         if (inp->inp_socket->so_options & SO_BROADCAST)
1422                 ipflags |= IP_ALLOWBROADCAST;
1423         if (inp->inp_flags & INP_ONESBCAST)
1424                 ipflags |= IP_SENDONES;
1425
1426 #ifdef MAC
1427         mac_inpcb_create_mbuf(inp, m);
1428 #endif
1429
1430         /*
1431          * Set up checksum and output datagram.
1432          */
1433         ui->ui_sum = 0;
1434         if (pr == IPPROTO_UDPLITE) {
1435                 if (inp->inp_flags & INP_ONESBCAST)
1436                         faddr.s_addr = INADDR_BROADCAST;
1437                 if (cscov_partial) {
1438                         if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1439                                 ui->ui_sum = 0xffff;
1440                 } else {
1441                         if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1442                                 ui->ui_sum = 0xffff;
1443                 }
1444         } else if (V_udp_cksum) {
1445                 if (inp->inp_flags & INP_ONESBCAST)
1446                         faddr.s_addr = INADDR_BROADCAST;
1447                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1448                     htons((u_short)len + sizeof(struct udphdr) + pr));
1449                 m->m_pkthdr.csum_flags = CSUM_UDP;
1450                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1451         }
1452         ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1453         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1454         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1455         UDPSTAT_INC(udps_opackets);
1456
1457         /*
1458          * Setup flowid / RSS information for outbound socket.
1459          *
1460          * Once the UDP code decides to set a flowid some other way,
1461          * this allows the flowid to be overridden by userland.
1462          */
1463         if (flowtype != M_HASHTYPE_NONE) {
1464                 m->m_pkthdr.flowid = flowid;
1465                 M_HASHTYPE_SET(m, flowtype);
1466 #ifdef  RSS
1467         } else {
1468                 uint32_t hash_val, hash_type;
1469                 /*
1470                  * Calculate an appropriate RSS hash for UDP and
1471                  * UDP Lite.
1472                  *
1473                  * The called function will take care of figuring out
1474                  * whether a 2-tuple or 4-tuple hash is required based
1475                  * on the currently configured scheme.
1476                  *
1477                  * Later later on connected socket values should be
1478                  * cached in the inpcb and reused, rather than constantly
1479                  * re-calculating it.
1480                  *
1481                  * UDP Lite is a different protocol number and will
1482                  * likely end up being hashed as a 2-tuple until
1483                  * RSS / NICs grow UDP Lite protocol awareness.
1484                  */
1485                 if (rss_proto_software_hash_v4(faddr, laddr, fport, lport,
1486                     pr, &hash_val, &hash_type) == 0) {
1487                         m->m_pkthdr.flowid = hash_val;
1488                         M_HASHTYPE_SET(m, hash_type);
1489                 }
1490 #endif
1491         }
1492
1493 #ifdef  RSS
1494         /*
1495          * Don't override with the inp cached flowid value.
1496          *
1497          * Depending upon the kind of send being done, the inp
1498          * flowid/flowtype values may actually not be appropriate
1499          * for this particular socket send.
1500          *
1501          * We should either leave the flowid at zero (which is what is
1502          * currently done) or set it to some software generated
1503          * hash value based on the packet contents.
1504          */
1505         ipflags |= IP_NODEFAULTFLOWID;
1506 #endif  /* RSS */
1507
1508         if (unlock_udbinfo == UH_WLOCKED)
1509                 INP_HASH_WUNLOCK(pcbinfo);
1510         else if (unlock_udbinfo == UH_RLOCKED)
1511                 INP_HASH_RUNLOCK(pcbinfo);
1512         UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1513         error = ip_output(m, inp->inp_options,
1514             (unlock_inp == UH_WLOCKED ? &inp->inp_route : NULL), ipflags,
1515             inp->inp_moptions, inp);
1516         if (unlock_inp == UH_WLOCKED)
1517                 INP_WUNLOCK(inp);
1518         else
1519                 INP_RUNLOCK(inp);
1520         return (error);
1521
1522 release:
1523         if (unlock_udbinfo == UH_WLOCKED) {
1524                 KASSERT(unlock_inp == UH_WLOCKED,
1525                     ("%s: excl udbinfo lock, shared inp lock", __func__));
1526                 INP_HASH_WUNLOCK(pcbinfo);
1527                 INP_WUNLOCK(inp);
1528         } else if (unlock_udbinfo == UH_RLOCKED) {
1529                 KASSERT(unlock_inp == UH_RLOCKED,
1530                     ("%s: shared udbinfo lock, excl inp lock", __func__));
1531                 INP_HASH_RUNLOCK(pcbinfo);
1532                 INP_RUNLOCK(inp);
1533         } else if (unlock_inp == UH_WLOCKED)
1534                 INP_WUNLOCK(inp);
1535         else
1536                 INP_RUNLOCK(inp);
1537         m_freem(m);
1538         return (error);
1539 }
1540
1541 static void
1542 udp_abort(struct socket *so)
1543 {
1544         struct inpcb *inp;
1545         struct inpcbinfo *pcbinfo;
1546
1547         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1548         inp = sotoinpcb(so);
1549         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1550         INP_WLOCK(inp);
1551         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1552                 INP_HASH_WLOCK(pcbinfo);
1553                 in_pcbdisconnect(inp);
1554                 inp->inp_laddr.s_addr = INADDR_ANY;
1555                 INP_HASH_WUNLOCK(pcbinfo);
1556                 soisdisconnected(so);
1557         }
1558         INP_WUNLOCK(inp);
1559 }
1560
1561 static int
1562 udp_attach(struct socket *so, int proto, struct thread *td)
1563 {
1564         struct inpcb *inp;
1565         struct inpcbinfo *pcbinfo;
1566         int error;
1567
1568         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1569         inp = sotoinpcb(so);
1570         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1571         error = soreserve(so, udp_sendspace, udp_recvspace);
1572         if (error)
1573                 return (error);
1574         INP_INFO_WLOCK(pcbinfo);
1575         error = in_pcballoc(so, pcbinfo);
1576         if (error) {
1577                 INP_INFO_WUNLOCK(pcbinfo);
1578                 return (error);
1579         }
1580
1581         inp = sotoinpcb(so);
1582         inp->inp_vflag |= INP_IPV4;
1583         inp->inp_ip_ttl = V_ip_defttl;
1584
1585         error = udp_newudpcb(inp);
1586         if (error) {
1587                 in_pcbdetach(inp);
1588                 in_pcbfree(inp);
1589                 INP_INFO_WUNLOCK(pcbinfo);
1590                 return (error);
1591         }
1592
1593         INP_WUNLOCK(inp);
1594         INP_INFO_WUNLOCK(pcbinfo);
1595         return (0);
1596 }
1597 #endif /* INET */
1598
1599 int
1600 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1601 {
1602         struct inpcb *inp;
1603         struct udpcb *up;
1604
1605         KASSERT(so->so_type == SOCK_DGRAM,
1606             ("udp_set_kernel_tunneling: !dgram"));
1607         inp = sotoinpcb(so);
1608         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1609         INP_WLOCK(inp);
1610         up = intoudpcb(inp);
1611         if ((up->u_tun_func != NULL) ||
1612             (up->u_icmp_func != NULL)) {
1613                 INP_WUNLOCK(inp);
1614                 return (EBUSY);
1615         }
1616         up->u_tun_func = f;
1617         up->u_icmp_func = i;
1618         up->u_tun_ctx = ctx;
1619         INP_WUNLOCK(inp);
1620         return (0);
1621 }
1622
1623 #ifdef INET
1624 static int
1625 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1626 {
1627         struct inpcb *inp;
1628         struct inpcbinfo *pcbinfo;
1629         int error;
1630
1631         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1632         inp = sotoinpcb(so);
1633         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1634         INP_WLOCK(inp);
1635         INP_HASH_WLOCK(pcbinfo);
1636         error = in_pcbbind(inp, nam, td->td_ucred);
1637         INP_HASH_WUNLOCK(pcbinfo);
1638         INP_WUNLOCK(inp);
1639         return (error);
1640 }
1641
1642 static void
1643 udp_close(struct socket *so)
1644 {
1645         struct inpcb *inp;
1646         struct inpcbinfo *pcbinfo;
1647
1648         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1649         inp = sotoinpcb(so);
1650         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1651         INP_WLOCK(inp);
1652         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1653                 INP_HASH_WLOCK(pcbinfo);
1654                 in_pcbdisconnect(inp);
1655                 inp->inp_laddr.s_addr = INADDR_ANY;
1656                 INP_HASH_WUNLOCK(pcbinfo);
1657                 soisdisconnected(so);
1658         }
1659         INP_WUNLOCK(inp);
1660 }
1661
1662 static int
1663 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1664 {
1665         struct inpcb *inp;
1666         struct inpcbinfo *pcbinfo;
1667         struct sockaddr_in *sin;
1668         int error;
1669
1670         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1671         inp = sotoinpcb(so);
1672         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1673         INP_WLOCK(inp);
1674         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1675                 INP_WUNLOCK(inp);
1676                 return (EISCONN);
1677         }
1678         sin = (struct sockaddr_in *)nam;
1679         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1680         if (error != 0) {
1681                 INP_WUNLOCK(inp);
1682                 return (error);
1683         }
1684         INP_HASH_WLOCK(pcbinfo);
1685         error = in_pcbconnect(inp, nam, td->td_ucred);
1686         INP_HASH_WUNLOCK(pcbinfo);
1687         if (error == 0)
1688                 soisconnected(so);
1689         INP_WUNLOCK(inp);
1690         return (error);
1691 }
1692
1693 static void
1694 udp_detach(struct socket *so)
1695 {
1696         struct inpcb *inp;
1697         struct inpcbinfo *pcbinfo;
1698         struct udpcb *up;
1699
1700         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1701         inp = sotoinpcb(so);
1702         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1703         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1704             ("udp_detach: not disconnected"));
1705         INP_INFO_WLOCK(pcbinfo);
1706         INP_WLOCK(inp);
1707         up = intoudpcb(inp);
1708         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1709         inp->inp_ppcb = NULL;
1710         in_pcbdetach(inp);
1711         in_pcbfree(inp);
1712         INP_INFO_WUNLOCK(pcbinfo);
1713         udp_discardcb(up);
1714 }
1715
1716 static int
1717 udp_disconnect(struct socket *so)
1718 {
1719         struct inpcb *inp;
1720         struct inpcbinfo *pcbinfo;
1721
1722         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1723         inp = sotoinpcb(so);
1724         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1725         INP_WLOCK(inp);
1726         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1727                 INP_WUNLOCK(inp);
1728                 return (ENOTCONN);
1729         }
1730         INP_HASH_WLOCK(pcbinfo);
1731         in_pcbdisconnect(inp);
1732         inp->inp_laddr.s_addr = INADDR_ANY;
1733         INP_HASH_WUNLOCK(pcbinfo);
1734         SOCK_LOCK(so);
1735         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1736         SOCK_UNLOCK(so);
1737         INP_WUNLOCK(inp);
1738         return (0);
1739 }
1740
1741 static int
1742 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1743     struct mbuf *control, struct thread *td)
1744 {
1745         struct inpcb *inp;
1746
1747         inp = sotoinpcb(so);
1748         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1749         return (udp_output(inp, m, addr, control, td));
1750 }
1751 #endif /* INET */
1752
1753 int
1754 udp_shutdown(struct socket *so)
1755 {
1756         struct inpcb *inp;
1757
1758         inp = sotoinpcb(so);
1759         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1760         INP_WLOCK(inp);
1761         socantsendmore(so);
1762         INP_WUNLOCK(inp);
1763         return (0);
1764 }
1765
1766 #ifdef INET
1767 struct pr_usrreqs udp_usrreqs = {
1768         .pru_abort =            udp_abort,
1769         .pru_attach =           udp_attach,
1770         .pru_bind =             udp_bind,
1771         .pru_connect =          udp_connect,
1772         .pru_control =          in_control,
1773         .pru_detach =           udp_detach,
1774         .pru_disconnect =       udp_disconnect,
1775         .pru_peeraddr =         in_getpeeraddr,
1776         .pru_send =             udp_send,
1777         .pru_soreceive =        soreceive_dgram,
1778         .pru_sosend =           sosend_dgram,
1779         .pru_shutdown =         udp_shutdown,
1780         .pru_sockaddr =         in_getsockaddr,
1781         .pru_sosetlabel =       in_pcbsosetlabel,
1782         .pru_close =            udp_close,
1783 };
1784 #endif /* INET */