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1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
5  *      The Regents of the University of California.
6  * Copyright (c) 2008 Robert N. M. Watson
7  * Copyright (c) 2010-2011 Juniper Networks, Inc.
8  * Copyright (c) 2014 Kevin Lo
9  * All rights reserved.
10  *
11  * Portions of this software were developed by Robert N. M. Watson under
12  * contract to Juniper Networks, Inc.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
39  */
40
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43
44 #include "opt_inet.h"
45 #include "opt_inet6.h"
46 #include "opt_ipsec.h"
47 #include "opt_route.h"
48 #include "opt_rss.h"
49
50 #include <sys/param.h>
51 #include <sys/domain.h>
52 #include <sys/eventhandler.h>
53 #include <sys/jail.h>
54 #include <sys/kernel.h>
55 #include <sys/lock.h>
56 #include <sys/malloc.h>
57 #include <sys/mbuf.h>
58 #include <sys/priv.h>
59 #include <sys/proc.h>
60 #include <sys/protosw.h>
61 #include <sys/sdt.h>
62 #include <sys/signalvar.h>
63 #include <sys/socket.h>
64 #include <sys/socketvar.h>
65 #include <sys/sx.h>
66 #include <sys/sysctl.h>
67 #include <sys/syslog.h>
68 #include <sys/systm.h>
69
70 #include <vm/uma.h>
71
72 #include <net/if.h>
73 #include <net/if_var.h>
74 #include <net/route.h>
75 #include <net/route/nhop.h>
76 #include <net/rss_config.h>
77
78 #include <netinet/in.h>
79 #include <netinet/in_kdtrace.h>
80 #include <netinet/in_fib.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/in_systm.h>
83 #include <netinet/in_var.h>
84 #include <netinet/ip.h>
85 #ifdef INET6
86 #include <netinet/ip6.h>
87 #endif
88 #include <netinet/ip_icmp.h>
89 #include <netinet/icmp_var.h>
90 #include <netinet/ip_var.h>
91 #include <netinet/ip_options.h>
92 #ifdef INET6
93 #include <netinet6/ip6_var.h>
94 #endif
95 #include <netinet/udp.h>
96 #include <netinet/udp_var.h>
97 #include <netinet/udplite.h>
98 #include <netinet/in_rss.h>
99
100 #include <netipsec/ipsec_support.h>
101
102 #include <machine/in_cksum.h>
103
104 #include <security/mac/mac_framework.h>
105
106 /*
107  * UDP and UDP-Lite protocols implementation.
108  * Per RFC 768, August, 1980.
109  * Per RFC 3828, July, 2004.
110  */
111
112 /*
113  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
114  * removes the only data integrity mechanism for packets and malformed
115  * packets that would otherwise be discarded due to bad checksums, and may
116  * cause problems (especially for NFS data blocks).
117  */
118 VNET_DEFINE(int, udp_cksum) = 1;
119 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_VNET | CTLFLAG_RW,
120     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
121
122 VNET_DEFINE(int, udp_log_in_vain) = 0;
123 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_VNET | CTLFLAG_RW,
124     &VNET_NAME(udp_log_in_vain), 0, "Log all incoming UDP packets");
125
126 VNET_DEFINE(int, udp_blackhole) = 0;
127 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_VNET | CTLFLAG_RW,
128     &VNET_NAME(udp_blackhole), 0,
129     "Do not send port unreachables for refused connects");
130 VNET_DEFINE(bool, udp_blackhole_local) = false;
131 SYSCTL_BOOL(_net_inet_udp, OID_AUTO, blackhole_local, CTLFLAG_VNET |
132     CTLFLAG_RW, &VNET_NAME(udp_blackhole_local), false,
133     "Enforce net.inet.udp.blackhole for locally originated packets");
134
135 u_long  udp_sendspace = 9216;           /* really max datagram size */
136 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
137     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
138
139 u_long  udp_recvspace = 40 * (1024 +
140 #ifdef INET6
141                                       sizeof(struct sockaddr_in6)
142 #else
143                                       sizeof(struct sockaddr_in)
144 #endif
145                                       );        /* 40 1K datagrams */
146
147 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
148     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
149
150 VNET_DEFINE(struct inpcbinfo, udbinfo);
151 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
152 VNET_DEFINE_STATIC(uma_zone_t, udpcb_zone);
153 #define V_udpcb_zone                    VNET(udpcb_zone)
154
155 #ifndef UDBHASHSIZE
156 #define UDBHASHSIZE     128
157 #endif
158
159 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);          /* from udp_var.h */
160 VNET_PCPUSTAT_SYSINIT(udpstat);
161 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
162     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
163
164 #ifdef VIMAGE
165 VNET_PCPUSTAT_SYSUNINIT(udpstat);
166 #endif /* VIMAGE */
167 #ifdef INET
168 static void     udp_detach(struct socket *so);
169 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
170                     struct mbuf *, struct thread *, int);
171 #endif
172
173 INPCBSTORAGE_DEFINE(udpcbstor, "udpinp", "udp_inpcb", "udp", "udphash");
174 INPCBSTORAGE_DEFINE(udplitecbstor, "udpliteinp", "udplite_inpcb", "udplite",
175     "udplitehash");
176
177 static void
178 udp_vnet_init(void *arg __unused)
179 {
180
181         /*
182          * For now default to 2-tuple UDP hashing - until the fragment
183          * reassembly code can also update the flowid.
184          *
185          * Once we can calculate the flowid that way and re-establish
186          * a 4-tuple, flip this to 4-tuple.
187          */
188         in_pcbinfo_init(&V_udbinfo, &udpcbstor, UDBHASHSIZE, UDBHASHSIZE);
189         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
190             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
191         uma_zone_set_max(V_udpcb_zone, maxsockets);
192         uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
193
194         /* Additional pcbinfo for UDP-Lite */
195         in_pcbinfo_init(&V_ulitecbinfo, &udplitecbstor, UDBHASHSIZE,
196             UDBHASHSIZE);
197 }
198 VNET_SYSINIT(udp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
199     udp_vnet_init, NULL);
200
201 /*
202  * Kernel module interface for updating udpstat.  The argument is an index
203  * into udpstat treated as an array of u_long.  While this encodes the
204  * general layout of udpstat into the caller, it doesn't encode its location,
205  * so that future changes to add, for example, per-CPU stats support won't
206  * cause binary compatibility problems for kernel modules.
207  */
208 void
209 kmod_udpstat_inc(int statnum)
210 {
211
212         counter_u64_add(VNET(udpstat)[statnum], 1);
213 }
214
215 int
216 udp_newudpcb(struct inpcb *inp)
217 {
218         struct udpcb *up;
219
220         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
221         if (up == NULL)
222                 return (ENOBUFS);
223         inp->inp_ppcb = up;
224         return (0);
225 }
226
227 void
228 udp_discardcb(struct udpcb *up)
229 {
230
231         uma_zfree(V_udpcb_zone, up);
232 }
233
234 #ifdef VIMAGE
235 static void
236 udp_destroy(void *unused __unused)
237 {
238
239         in_pcbinfo_destroy(&V_udbinfo);
240         uma_zdestroy(V_udpcb_zone);
241 }
242 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
243
244 static void
245 udplite_destroy(void *unused __unused)
246 {
247
248         in_pcbinfo_destroy(&V_ulitecbinfo);
249 }
250 VNET_SYSUNINIT(udplite, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udplite_destroy,
251     NULL);
252 #endif
253
254 #ifdef INET
255 /*
256  * Subroutine of udp_input(), which appends the provided mbuf chain to the
257  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
258  * contains the source address.  If the socket ends up being an IPv6 socket,
259  * udp_append() will convert to a sockaddr_in6 before passing the address
260  * into the socket code.
261  *
262  * In the normal case udp_append() will return 0, indicating that you
263  * must unlock the inp. However if a tunneling protocol is in place we increment
264  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
265  * then decrement the reference count. If the inp_rele returns 1, indicating the
266  * inp is gone, we return that to the caller to tell them *not* to unlock
267  * the inp. In the case of multi-cast this will cause the distribution
268  * to stop (though most tunneling protocols known currently do *not* use
269  * multicast).
270  */
271 static int
272 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
273     struct sockaddr_in *udp_in)
274 {
275         struct sockaddr *append_sa;
276         struct socket *so;
277         struct mbuf *tmpopts, *opts = NULL;
278 #ifdef INET6
279         struct sockaddr_in6 udp_in6;
280 #endif
281         struct udpcb *up;
282         bool filtered;
283
284         INP_LOCK_ASSERT(inp);
285
286         /*
287          * Engage the tunneling protocol.
288          */
289         up = intoudpcb(inp);
290         if (up->u_tun_func != NULL) {
291                 in_pcbref(inp);
292                 INP_RUNLOCK(inp);
293                 filtered = (*up->u_tun_func)(n, off, inp, (struct sockaddr *)&udp_in[0],
294                     up->u_tun_ctx);
295                 INP_RLOCK(inp);
296                 if (filtered)
297                         return (in_pcbrele_rlocked(inp));
298         }
299
300         off += sizeof(struct udphdr);
301
302 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
303         /* Check AH/ESP integrity. */
304         if (IPSEC_ENABLED(ipv4) &&
305             IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
306                 m_freem(n);
307                 return (0);
308         }
309         if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
310                 if (IPSEC_ENABLED(ipv4) &&
311                     UDPENCAP_INPUT(n, off, AF_INET) != 0)
312                         return (0);     /* Consumed. */
313         }
314 #endif /* IPSEC */
315 #ifdef MAC
316         if (mac_inpcb_check_deliver(inp, n) != 0) {
317                 m_freem(n);
318                 return (0);
319         }
320 #endif /* MAC */
321         if (inp->inp_flags & INP_CONTROLOPTS ||
322             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
323 #ifdef INET6
324                 if (inp->inp_vflag & INP_IPV6)
325                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
326                 else
327 #endif /* INET6 */
328                         ip_savecontrol(inp, &opts, ip, n);
329         }
330         if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
331                 tmpopts = sbcreatecontrol(&udp_in[1],
332                     sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP,
333                     M_NOWAIT);
334                 if (tmpopts) {
335                         if (opts) {
336                                 tmpopts->m_next = opts;
337                                 opts = tmpopts;
338                         } else
339                                 opts = tmpopts;
340                 }
341         }
342 #ifdef INET6
343         if (inp->inp_vflag & INP_IPV6) {
344                 bzero(&udp_in6, sizeof(udp_in6));
345                 udp_in6.sin6_len = sizeof(udp_in6);
346                 udp_in6.sin6_family = AF_INET6;
347                 in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
348                 append_sa = (struct sockaddr *)&udp_in6;
349         } else
350 #endif /* INET6 */
351                 append_sa = (struct sockaddr *)&udp_in[0];
352         m_adj(n, off);
353
354         so = inp->inp_socket;
355         SOCKBUF_LOCK(&so->so_rcv);
356         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
357                 soroverflow_locked(so);
358                 m_freem(n);
359                 if (opts)
360                         m_freem(opts);
361                 UDPSTAT_INC(udps_fullsock);
362         } else
363                 sorwakeup_locked(so);
364         return (0);
365 }
366
367 static bool
368 udp_multi_match(const struct inpcb *inp, void *v)
369 {
370         struct ip *ip = v;
371         struct udphdr *uh = (struct udphdr *)(ip + 1);
372
373         if (inp->inp_lport != uh->uh_dport)
374                 return (false);
375 #ifdef INET6
376         if ((inp->inp_vflag & INP_IPV4) == 0)
377                 return (false);
378 #endif
379         if (inp->inp_laddr.s_addr != INADDR_ANY &&
380             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
381                 return (false);
382         if (inp->inp_faddr.s_addr != INADDR_ANY &&
383             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
384                 return (false);
385         if (inp->inp_fport != 0 &&
386             inp->inp_fport != uh->uh_sport)
387                 return (false);
388
389         return (true);
390 }
391
392 static int
393 udp_multi_input(struct mbuf *m, int proto, struct sockaddr_in *udp_in)
394 {
395         struct ip *ip = mtod(m, struct ip *);
396         struct inpcb_iterator inpi = INP_ITERATOR(udp_get_inpcbinfo(proto),
397             INPLOOKUP_RLOCKPCB, udp_multi_match, ip);
398 #ifdef KDTRACE_HOOKS
399         struct udphdr *uh = (struct udphdr *)(ip + 1);
400 #endif
401         struct inpcb *inp;
402         struct mbuf *n;
403         int appends = 0;
404
405         MPASS(ip->ip_hl == sizeof(struct ip) >> 2);
406
407         while ((inp = inp_next(&inpi)) != NULL) {
408                 /*
409                  * XXXRW: Because we weren't holding either the inpcb
410                  * or the hash lock when we checked for a match
411                  * before, we should probably recheck now that the
412                  * inpcb lock is held.
413                  */
414                 /*
415                  * Handle socket delivery policy for any-source
416                  * and source-specific multicast. [RFC3678]
417                  */
418                 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
419                         struct ip_moptions      *imo;
420                         struct sockaddr_in       group;
421                         int                      blocked;
422
423                         imo = inp->inp_moptions;
424                         if (imo == NULL)
425                                 continue;
426                         bzero(&group, sizeof(struct sockaddr_in));
427                         group.sin_len = sizeof(struct sockaddr_in);
428                         group.sin_family = AF_INET;
429                         group.sin_addr = ip->ip_dst;
430
431                         blocked = imo_multi_filter(imo, m->m_pkthdr.rcvif,
432                                 (struct sockaddr *)&group,
433                                 (struct sockaddr *)&udp_in[0]);
434                         if (blocked != MCAST_PASS) {
435                                 if (blocked == MCAST_NOTGMEMBER)
436                                         IPSTAT_INC(ips_notmember);
437                                 if (blocked == MCAST_NOTSMEMBER ||
438                                     blocked == MCAST_MUTED)
439                                         UDPSTAT_INC(udps_filtermcast);
440                                 continue;
441                         }
442                 }
443                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
444                         if (proto == IPPROTO_UDPLITE)
445                                 UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
446                         else
447                                 UDP_PROBE(receive, NULL, inp, ip, inp, uh);
448                         if (udp_append(inp, ip, n, sizeof(struct ip), udp_in)) {
449                                 INP_RUNLOCK(inp);
450                                 break;
451                         } else
452                                 appends++;
453                 }
454                 /*
455                  * Don't look for additional matches if this one does
456                  * not have either the SO_REUSEPORT or SO_REUSEADDR
457                  * socket options set.  This heuristic avoids
458                  * searching through all pcbs in the common case of a
459                  * non-shared port.  It assumes that an application
460                  * will never clear these options after setting them.
461                  */
462                 if ((inp->inp_socket->so_options &
463                     (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0) {
464                         INP_RUNLOCK(inp);
465                         break;
466                 }
467         }
468
469         if (appends == 0) {
470                 /*
471                  * No matching pcb found; discard datagram.  (No need
472                  * to send an ICMP Port Unreachable for a broadcast
473                  * or multicast datgram.)
474                  */
475                 UDPSTAT_INC(udps_noport);
476                 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)))
477                         UDPSTAT_INC(udps_noportmcast);
478                 else
479                         UDPSTAT_INC(udps_noportbcast);
480         }
481         m_freem(m);
482
483         return (IPPROTO_DONE);
484 }
485
486 static int
487 udp_input(struct mbuf **mp, int *offp, int proto)
488 {
489         struct ip *ip;
490         struct udphdr *uh;
491         struct ifnet *ifp;
492         struct inpcb *inp;
493         uint16_t len, ip_len;
494         struct inpcbinfo *pcbinfo;
495         struct sockaddr_in udp_in[2];
496         struct mbuf *m;
497         struct m_tag *fwd_tag;
498         int cscov_partial, iphlen;
499
500         m = *mp;
501         iphlen = *offp;
502         ifp = m->m_pkthdr.rcvif;
503         *mp = NULL;
504         UDPSTAT_INC(udps_ipackets);
505
506         /*
507          * Strip IP options, if any; should skip this, make available to
508          * user, and use on returned packets, but we don't yet have a way to
509          * check the checksum with options still present.
510          */
511         if (iphlen > sizeof (struct ip)) {
512                 ip_stripoptions(m);
513                 iphlen = sizeof(struct ip);
514         }
515
516         /*
517          * Get IP and UDP header together in first mbuf.
518          */
519         if (m->m_len < iphlen + sizeof(struct udphdr)) {
520                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
521                         UDPSTAT_INC(udps_hdrops);
522                         return (IPPROTO_DONE);
523                 }
524         }
525         ip = mtod(m, struct ip *);
526         uh = (struct udphdr *)((caddr_t)ip + iphlen);
527         cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
528
529         /*
530          * Destination port of 0 is illegal, based on RFC768.
531          */
532         if (uh->uh_dport == 0)
533                 goto badunlocked;
534
535         /*
536          * Construct sockaddr format source address.  Stuff source address
537          * and datagram in user buffer.
538          */
539         bzero(&udp_in[0], sizeof(struct sockaddr_in) * 2);
540         udp_in[0].sin_len = sizeof(struct sockaddr_in);
541         udp_in[0].sin_family = AF_INET;
542         udp_in[0].sin_port = uh->uh_sport;
543         udp_in[0].sin_addr = ip->ip_src;
544         udp_in[1].sin_len = sizeof(struct sockaddr_in);
545         udp_in[1].sin_family = AF_INET;
546         udp_in[1].sin_port = uh->uh_dport;
547         udp_in[1].sin_addr = ip->ip_dst;
548
549         /*
550          * Make mbuf data length reflect UDP length.  If not enough data to
551          * reflect UDP length, drop.
552          */
553         len = ntohs((u_short)uh->uh_ulen);
554         ip_len = ntohs(ip->ip_len) - iphlen;
555         if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
556                 /* Zero means checksum over the complete packet. */
557                 if (len == 0)
558                         len = ip_len;
559                 cscov_partial = 0;
560         }
561         if (ip_len != len) {
562                 if (len > ip_len || len < sizeof(struct udphdr)) {
563                         UDPSTAT_INC(udps_badlen);
564                         goto badunlocked;
565                 }
566                 if (proto == IPPROTO_UDP)
567                         m_adj(m, len - ip_len);
568         }
569
570         /*
571          * Checksum extended UDP header and data.
572          */
573         if (uh->uh_sum) {
574                 u_short uh_sum;
575
576                 if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
577                     !cscov_partial) {
578                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
579                                 uh_sum = m->m_pkthdr.csum_data;
580                         else
581                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
582                                     ip->ip_dst.s_addr, htonl((u_short)len +
583                                     m->m_pkthdr.csum_data + proto));
584                         uh_sum ^= 0xffff;
585                 } else {
586                         char b[offsetof(struct ipovly, ih_src)];
587                         struct ipovly *ipov = (struct ipovly *)ip;
588
589                         bcopy(ipov, b, sizeof(b));
590                         bzero(ipov, sizeof(ipov->ih_x1));
591                         ipov->ih_len = (proto == IPPROTO_UDP) ?
592                             uh->uh_ulen : htons(ip_len);
593                         uh_sum = in_cksum(m, len + sizeof (struct ip));
594                         bcopy(b, ipov, sizeof(b));
595                 }
596                 if (uh_sum) {
597                         UDPSTAT_INC(udps_badsum);
598                         m_freem(m);
599                         return (IPPROTO_DONE);
600                 }
601         } else {
602                 if (proto == IPPROTO_UDP) {
603                         UDPSTAT_INC(udps_nosum);
604                 } else {
605                         /* UDPLite requires a checksum */
606                         /* XXX: What is the right UDPLite MIB counter here? */
607                         m_freem(m);
608                         return (IPPROTO_DONE);
609                 }
610         }
611
612         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
613             in_broadcast(ip->ip_dst, ifp))
614                 return (udp_multi_input(m, proto, udp_in));
615
616         pcbinfo = udp_get_inpcbinfo(proto);
617
618         /*
619          * Locate pcb for datagram.
620          *
621          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
622          */
623         if ((m->m_flags & M_IP_NEXTHOP) &&
624             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
625                 struct sockaddr_in *next_hop;
626
627                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
628
629                 /*
630                  * Transparently forwarded. Pretend to be the destination.
631                  * Already got one like this?
632                  */
633                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
634                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
635                 if (!inp) {
636                         /*
637                          * It's new.  Try to find the ambushing socket.
638                          * Because we've rewritten the destination address,
639                          * any hardware-generated hash is ignored.
640                          */
641                         inp = in_pcblookup(pcbinfo, ip->ip_src,
642                             uh->uh_sport, next_hop->sin_addr,
643                             next_hop->sin_port ? htons(next_hop->sin_port) :
644                             uh->uh_dport, INPLOOKUP_WILDCARD |
645                             INPLOOKUP_RLOCKPCB, ifp);
646                 }
647                 /* Remove the tag from the packet. We don't need it anymore. */
648                 m_tag_delete(m, fwd_tag);
649                 m->m_flags &= ~M_IP_NEXTHOP;
650         } else
651                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
652                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
653                     INPLOOKUP_RLOCKPCB, ifp, m);
654         if (inp == NULL) {
655                 if (V_udp_log_in_vain) {
656                         char src[INET_ADDRSTRLEN];
657                         char dst[INET_ADDRSTRLEN];
658
659                         log(LOG_INFO,
660                             "Connection attempt to UDP %s:%d from %s:%d\n",
661                             inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
662                             inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
663                 }
664                 if (proto == IPPROTO_UDPLITE)
665                         UDPLITE_PROBE(receive, NULL, NULL, ip, NULL, uh);
666                 else
667                         UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
668                 UDPSTAT_INC(udps_noport);
669                 if (m->m_flags & (M_BCAST | M_MCAST)) {
670                         UDPSTAT_INC(udps_noportbcast);
671                         goto badunlocked;
672                 }
673                 if (V_udp_blackhole && (V_udp_blackhole_local ||
674                     !in_localip(ip->ip_src)))
675                         goto badunlocked;
676                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
677                         goto badunlocked;
678                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
679                 return (IPPROTO_DONE);
680         }
681
682         /*
683          * Check the minimum TTL for socket.
684          */
685         INP_RLOCK_ASSERT(inp);
686         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
687                 if (proto == IPPROTO_UDPLITE)
688                         UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
689                 else
690                         UDP_PROBE(receive, NULL, inp, ip, inp, uh);
691                 INP_RUNLOCK(inp);
692                 m_freem(m);
693                 return (IPPROTO_DONE);
694         }
695         if (cscov_partial) {
696                 struct udpcb *up;
697
698                 up = intoudpcb(inp);
699                 if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
700                         INP_RUNLOCK(inp);
701                         m_freem(m);
702                         return (IPPROTO_DONE);
703                 }
704         }
705
706         if (proto == IPPROTO_UDPLITE)
707                 UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
708         else
709                 UDP_PROBE(receive, NULL, inp, ip, inp, uh);
710         if (udp_append(inp, ip, m, iphlen, udp_in) == 0)
711                 INP_RUNLOCK(inp);
712         return (IPPROTO_DONE);
713
714 badunlocked:
715         m_freem(m);
716         return (IPPROTO_DONE);
717 }
718 #endif /* INET */
719
720 /*
721  * Notify a udp user of an asynchronous error; just wake up so that they can
722  * collect error status.
723  */
724 struct inpcb *
725 udp_notify(struct inpcb *inp, int errno)
726 {
727
728         INP_WLOCK_ASSERT(inp);
729         if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
730              errno == EHOSTDOWN) && inp->inp_route.ro_nh) {
731                 NH_FREE(inp->inp_route.ro_nh);
732                 inp->inp_route.ro_nh = (struct nhop_object *)NULL;
733         }
734
735         inp->inp_socket->so_error = errno;
736         sorwakeup(inp->inp_socket);
737         sowwakeup(inp->inp_socket);
738         return (inp);
739 }
740
741 #ifdef INET
742 static void
743 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
744     struct inpcbinfo *pcbinfo)
745 {
746         struct ip *ip = vip;
747         struct udphdr *uh;
748         struct in_addr faddr;
749         struct inpcb *inp;
750
751         faddr = ((struct sockaddr_in *)sa)->sin_addr;
752         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
753                 return;
754
755         if (PRC_IS_REDIRECT(cmd)) {
756                 /* signal EHOSTDOWN, as it flushes the cached route */
757                 in_pcbnotifyall(pcbinfo, faddr, EHOSTDOWN, udp_notify);
758                 return;
759         }
760
761         /*
762          * Hostdead is ugly because it goes linearly through all PCBs.
763          *
764          * XXX: We never get this from ICMP, otherwise it makes an excellent
765          * DoS attack on machines with many connections.
766          */
767         if (cmd == PRC_HOSTDEAD)
768                 ip = NULL;
769         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
770                 return;
771         if (ip != NULL) {
772                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
773                 inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
774                     ip->ip_src, uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
775                 if (inp != NULL) {
776                         INP_WLOCK_ASSERT(inp);
777                         if (inp->inp_socket != NULL) {
778                                 udp_notify(inp, inetctlerrmap[cmd]);
779                         }
780                         INP_WUNLOCK(inp);
781                 } else {
782                         inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
783                                            ip->ip_src, uh->uh_sport,
784                                            INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
785                         if (inp != NULL) {
786                                 struct udpcb *up;
787                                 void *ctx;
788                                 udp_tun_icmp_t func;
789
790                                 up = intoudpcb(inp);
791                                 ctx = up->u_tun_ctx;
792                                 func = up->u_icmp_func;
793                                 INP_RUNLOCK(inp);
794                                 if (func != NULL)
795                                         (*func)(cmd, sa, vip, ctx);
796                         }
797                 }
798         } else
799                 in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
800                     udp_notify);
801 }
802
803 static void
804 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
805 {
806
807         return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
808 }
809
810 static void
811 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
812 {
813
814         return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
815 }
816 #endif /* INET */
817
818 static int
819 udp_pcblist(SYSCTL_HANDLER_ARGS)
820 {
821         struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_udbinfo,
822             INPLOOKUP_RLOCKPCB);
823         struct xinpgen xig;
824         struct inpcb *inp;
825         int error;
826
827         if (req->newptr != 0)
828                 return (EPERM);
829
830         if (req->oldptr == 0) {
831                 int n;
832
833                 n = V_udbinfo.ipi_count;
834                 n += imax(n / 8, 10);
835                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
836                 return (0);
837         }
838
839         if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
840                 return (error);
841
842         bzero(&xig, sizeof(xig));
843         xig.xig_len = sizeof xig;
844         xig.xig_count = V_udbinfo.ipi_count;
845         xig.xig_gen = V_udbinfo.ipi_gencnt;
846         xig.xig_sogen = so_gencnt;
847         error = SYSCTL_OUT(req, &xig, sizeof xig);
848         if (error)
849                 return (error);
850
851         while ((inp = inp_next(&inpi)) != NULL) {
852                 if (inp->inp_gencnt <= xig.xig_gen &&
853                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
854                         struct xinpcb xi;
855
856                         in_pcbtoxinpcb(inp, &xi);
857                         error = SYSCTL_OUT(req, &xi, sizeof xi);
858                         if (error) {
859                                 INP_RUNLOCK(inp);
860                                 break;
861                         }
862                 }
863         }
864
865         if (!error) {
866                 /*
867                  * Give the user an updated idea of our state.  If the
868                  * generation differs from what we told her before, she knows
869                  * that something happened while we were processing this
870                  * request, and it might be necessary to retry.
871                  */
872                 xig.xig_gen = V_udbinfo.ipi_gencnt;
873                 xig.xig_sogen = so_gencnt;
874                 xig.xig_count = V_udbinfo.ipi_count;
875                 error = SYSCTL_OUT(req, &xig, sizeof xig);
876         }
877
878         return (error);
879 }
880
881 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
882     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
883     udp_pcblist, "S,xinpcb",
884     "List of active UDP sockets");
885
886 #ifdef INET
887 static int
888 udp_getcred(SYSCTL_HANDLER_ARGS)
889 {
890         struct xucred xuc;
891         struct sockaddr_in addrs[2];
892         struct epoch_tracker et;
893         struct inpcb *inp;
894         int error;
895
896         error = priv_check(req->td, PRIV_NETINET_GETCRED);
897         if (error)
898                 return (error);
899         error = SYSCTL_IN(req, addrs, sizeof(addrs));
900         if (error)
901                 return (error);
902         NET_EPOCH_ENTER(et);
903         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
904             addrs[0].sin_addr, addrs[0].sin_port,
905             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
906         NET_EPOCH_EXIT(et);
907         if (inp != NULL) {
908                 INP_RLOCK_ASSERT(inp);
909                 if (inp->inp_socket == NULL)
910                         error = ENOENT;
911                 if (error == 0)
912                         error = cr_canseeinpcb(req->td->td_ucred, inp);
913                 if (error == 0)
914                         cru2x(inp->inp_cred, &xuc);
915                 INP_RUNLOCK(inp);
916         } else
917                 error = ENOENT;
918         if (error == 0)
919                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
920         return (error);
921 }
922
923 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
924     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
925     0, 0, udp_getcred, "S,xucred",
926     "Get the xucred of a UDP connection");
927 #endif /* INET */
928
929 int
930 udp_ctloutput(struct socket *so, struct sockopt *sopt)
931 {
932         struct inpcb *inp;
933         struct udpcb *up;
934         int isudplite, error, optval;
935
936         error = 0;
937         isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
938         inp = sotoinpcb(so);
939         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
940         INP_WLOCK(inp);
941         if (sopt->sopt_level != so->so_proto->pr_protocol) {
942 #ifdef INET6
943                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
944                         INP_WUNLOCK(inp);
945                         error = ip6_ctloutput(so, sopt);
946                 }
947 #endif
948 #if defined(INET) && defined(INET6)
949                 else
950 #endif
951 #ifdef INET
952                 {
953                         INP_WUNLOCK(inp);
954                         error = ip_ctloutput(so, sopt);
955                 }
956 #endif
957                 return (error);
958         }
959
960         switch (sopt->sopt_dir) {
961         case SOPT_SET:
962                 switch (sopt->sopt_name) {
963 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
964 #ifdef INET
965                 case UDP_ENCAP:
966                         if (!IPSEC_ENABLED(ipv4)) {
967                                 INP_WUNLOCK(inp);
968                                 return (ENOPROTOOPT);
969                         }
970                         error = UDPENCAP_PCBCTL(inp, sopt);
971                         break;
972 #endif /* INET */
973 #endif /* IPSEC */
974                 case UDPLITE_SEND_CSCOV:
975                 case UDPLITE_RECV_CSCOV:
976                         if (!isudplite) {
977                                 INP_WUNLOCK(inp);
978                                 error = ENOPROTOOPT;
979                                 break;
980                         }
981                         INP_WUNLOCK(inp);
982                         error = sooptcopyin(sopt, &optval, sizeof(optval),
983                             sizeof(optval));
984                         if (error != 0)
985                                 break;
986                         inp = sotoinpcb(so);
987                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
988                         INP_WLOCK(inp);
989                         up = intoudpcb(inp);
990                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
991                         if ((optval != 0 && optval < 8) || (optval > 65535)) {
992                                 INP_WUNLOCK(inp);
993                                 error = EINVAL;
994                                 break;
995                         }
996                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
997                                 up->u_txcslen = optval;
998                         else
999                                 up->u_rxcslen = optval;
1000                         INP_WUNLOCK(inp);
1001                         break;
1002                 default:
1003                         INP_WUNLOCK(inp);
1004                         error = ENOPROTOOPT;
1005                         break;
1006                 }
1007                 break;
1008         case SOPT_GET:
1009                 switch (sopt->sopt_name) {
1010 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1011 #ifdef INET
1012                 case UDP_ENCAP:
1013                         if (!IPSEC_ENABLED(ipv4)) {
1014                                 INP_WUNLOCK(inp);
1015                                 return (ENOPROTOOPT);
1016                         }
1017                         error = UDPENCAP_PCBCTL(inp, sopt);
1018                         break;
1019 #endif /* INET */
1020 #endif /* IPSEC */
1021                 case UDPLITE_SEND_CSCOV:
1022                 case UDPLITE_RECV_CSCOV:
1023                         if (!isudplite) {
1024                                 INP_WUNLOCK(inp);
1025                                 error = ENOPROTOOPT;
1026                                 break;
1027                         }
1028                         up = intoudpcb(inp);
1029                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1030                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1031                                 optval = up->u_txcslen;
1032                         else
1033                                 optval = up->u_rxcslen;
1034                         INP_WUNLOCK(inp);
1035                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1036                         break;
1037                 default:
1038                         INP_WUNLOCK(inp);
1039                         error = ENOPROTOOPT;
1040                         break;
1041                 }
1042                 break;
1043         }
1044         return (error);
1045 }
1046
1047 #ifdef INET
1048 #ifdef INET6
1049 /* The logic here is derived from ip6_setpktopt(). See comments there. */
1050 static int
1051 udp_v4mapped_pktinfo(struct cmsghdr *cm, struct sockaddr_in * src,
1052     struct inpcb *inp, int flags)
1053 {
1054         struct ifnet *ifp;
1055         struct in6_pktinfo *pktinfo;
1056         struct in_addr ia;
1057
1058         if ((flags & PRUS_IPV6) == 0)
1059                 return (0);
1060
1061         if (cm->cmsg_level != IPPROTO_IPV6)
1062                 return (0);
1063
1064         if  (cm->cmsg_type != IPV6_2292PKTINFO &&
1065             cm->cmsg_type != IPV6_PKTINFO)
1066                 return (0);
1067
1068         if (cm->cmsg_len !=
1069             CMSG_LEN(sizeof(struct in6_pktinfo)))
1070                 return (EINVAL);
1071
1072         pktinfo = (struct in6_pktinfo *)CMSG_DATA(cm);
1073         if (!IN6_IS_ADDR_V4MAPPED(&pktinfo->ipi6_addr) &&
1074             !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr))
1075                 return (EINVAL);
1076
1077         /* Validate the interface index if specified. */
1078         if (pktinfo->ipi6_ifindex) {
1079                 struct epoch_tracker et;
1080
1081                 NET_EPOCH_ENTER(et);
1082                 ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
1083                 NET_EPOCH_EXIT(et);     /* XXXGL: unsafe ifp */
1084                 if (ifp == NULL)
1085                         return (ENXIO);
1086         } else
1087                 ifp = NULL;
1088         if (ifp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
1089                 ia.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1090                 if (in_ifhasaddr(ifp, ia) == 0)
1091                         return (EADDRNOTAVAIL);
1092         }
1093
1094         bzero(src, sizeof(*src));
1095         src->sin_family = AF_INET;
1096         src->sin_len = sizeof(*src);
1097         src->sin_port = inp->inp_lport;
1098         src->sin_addr.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1099
1100         return (0);
1101 }
1102 #endif
1103
1104 static int
1105 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
1106     struct mbuf *control, struct thread *td, int flags)
1107 {
1108         struct udpiphdr *ui;
1109         int len = m->m_pkthdr.len;
1110         struct in_addr faddr, laddr;
1111         struct cmsghdr *cm;
1112         struct inpcbinfo *pcbinfo;
1113         struct sockaddr_in *sin, src;
1114         struct epoch_tracker et;
1115         int cscov_partial = 0;
1116         int error = 0;
1117         int ipflags = 0;
1118         u_short fport, lport;
1119         u_char tos;
1120         uint8_t pr;
1121         uint16_t cscov = 0;
1122         uint32_t flowid = 0;
1123         uint8_t flowtype = M_HASHTYPE_NONE;
1124
1125         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1126                 if (control)
1127                         m_freem(control);
1128                 m_freem(m);
1129                 return (EMSGSIZE);
1130         }
1131
1132         src.sin_family = 0;
1133         sin = (struct sockaddr_in *)addr;
1134
1135         /*
1136          * udp_output() may need to temporarily bind or connect the current
1137          * inpcb.  As such, we don't know up front whether we will need the
1138          * pcbinfo lock or not.  Do any work to decide what is needed up
1139          * front before acquiring any locks.
1140          *
1141          * We will need network epoch in either case, to safely lookup into
1142          * pcb hash.
1143          */
1144         if (sin == NULL ||
1145             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0))
1146                 INP_WLOCK(inp);
1147         else
1148                 INP_RLOCK(inp);
1149         NET_EPOCH_ENTER(et);
1150         tos = inp->inp_ip_tos;
1151         if (control != NULL) {
1152                 /*
1153                  * XXX: Currently, we assume all the optional information is
1154                  * stored in a single mbuf.
1155                  */
1156                 if (control->m_next) {
1157                         m_freem(control);
1158                         error = EINVAL;
1159                         goto release;
1160                 }
1161                 for (; control->m_len > 0;
1162                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
1163                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1164                         cm = mtod(control, struct cmsghdr *);
1165                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1166                             || cm->cmsg_len > control->m_len) {
1167                                 error = EINVAL;
1168                                 break;
1169                         }
1170 #ifdef INET6
1171                         error = udp_v4mapped_pktinfo(cm, &src, inp, flags);
1172                         if (error != 0)
1173                                 break;
1174 #endif
1175                         if (cm->cmsg_level != IPPROTO_IP)
1176                                 continue;
1177
1178                         switch (cm->cmsg_type) {
1179                         case IP_SENDSRCADDR:
1180                                 if (cm->cmsg_len !=
1181                                     CMSG_LEN(sizeof(struct in_addr))) {
1182                                         error = EINVAL;
1183                                         break;
1184                                 }
1185                                 bzero(&src, sizeof(src));
1186                                 src.sin_family = AF_INET;
1187                                 src.sin_len = sizeof(src);
1188                                 src.sin_port = inp->inp_lport;
1189                                 src.sin_addr =
1190                                     *(struct in_addr *)CMSG_DATA(cm);
1191                                 break;
1192
1193                         case IP_TOS:
1194                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1195                                         error = EINVAL;
1196                                         break;
1197                                 }
1198                                 tos = *(u_char *)CMSG_DATA(cm);
1199                                 break;
1200
1201                         case IP_FLOWID:
1202                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1203                                         error = EINVAL;
1204                                         break;
1205                                 }
1206                                 flowid = *(uint32_t *) CMSG_DATA(cm);
1207                                 break;
1208
1209                         case IP_FLOWTYPE:
1210                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1211                                         error = EINVAL;
1212                                         break;
1213                                 }
1214                                 flowtype = *(uint32_t *) CMSG_DATA(cm);
1215                                 break;
1216
1217 #ifdef  RSS
1218                         case IP_RSSBUCKETID:
1219                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1220                                         error = EINVAL;
1221                                         break;
1222                                 }
1223                                 /* This is just a placeholder for now */
1224                                 break;
1225 #endif  /* RSS */
1226                         default:
1227                                 error = ENOPROTOOPT;
1228                                 break;
1229                         }
1230                         if (error)
1231                                 break;
1232                 }
1233                 m_freem(control);
1234                 control = NULL;
1235         }
1236         if (error)
1237                 goto release;
1238
1239         pr = inp->inp_socket->so_proto->pr_protocol;
1240         pcbinfo = udp_get_inpcbinfo(pr);
1241
1242         /*
1243          * If the IP_SENDSRCADDR control message was specified, override the
1244          * source address for this datagram.  Its use is invalidated if the
1245          * address thus specified is incomplete or clobbers other inpcbs.
1246          */
1247         laddr = inp->inp_laddr;
1248         lport = inp->inp_lport;
1249         if (src.sin_family == AF_INET) {
1250                 if ((lport == 0) ||
1251                     (laddr.s_addr == INADDR_ANY &&
1252                      src.sin_addr.s_addr == INADDR_ANY)) {
1253                         error = EINVAL;
1254                         goto release;
1255                 }
1256                 INP_HASH_WLOCK(pcbinfo);
1257                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1258                     &laddr.s_addr, &lport, td->td_ucred);
1259                 INP_HASH_WUNLOCK(pcbinfo);
1260                 if (error)
1261                         goto release;
1262         }
1263
1264         /*
1265          * If a UDP socket has been connected, then a local address/port will
1266          * have been selected and bound.
1267          *
1268          * If a UDP socket has not been connected to, then an explicit
1269          * destination address must be used, in which case a local
1270          * address/port may not have been selected and bound.
1271          */
1272         if (sin != NULL) {
1273                 INP_LOCK_ASSERT(inp);
1274                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1275                         error = EISCONN;
1276                         goto release;
1277                 }
1278
1279                 /*
1280                  * Jail may rewrite the destination address, so let it do
1281                  * that before we use it.
1282                  */
1283                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1284                 if (error)
1285                         goto release;
1286
1287                 /*
1288                  * If a local address or port hasn't yet been selected, or if
1289                  * the destination address needs to be rewritten due to using
1290                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1291                  * to do the heavy lifting.  Once a port is selected, we
1292                  * commit the binding back to the socket; we also commit the
1293                  * binding of the address if in jail.
1294                  *
1295                  * If we already have a valid binding and we're not
1296                  * requesting a destination address rewrite, use a fast path.
1297                  */
1298                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1299                     inp->inp_lport == 0 ||
1300                     sin->sin_addr.s_addr == INADDR_ANY ||
1301                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1302                         INP_HASH_WLOCK(pcbinfo);
1303                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1304                             &lport, &faddr.s_addr, &fport, NULL,
1305                             td->td_ucred);
1306                         if (error) {
1307                                 INP_HASH_WUNLOCK(pcbinfo);
1308                                 goto release;
1309                         }
1310
1311                         /*
1312                          * XXXRW: Why not commit the port if the address is
1313                          * !INADDR_ANY?
1314                          */
1315                         /* Commit the local port if newly assigned. */
1316                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1317                             inp->inp_lport == 0) {
1318                                 INP_WLOCK_ASSERT(inp);
1319                                 /*
1320                                  * Remember addr if jailed, to prevent
1321                                  * rebinding.
1322                                  */
1323                                 if (prison_flag(td->td_ucred, PR_IP4))
1324                                         inp->inp_laddr = laddr;
1325                                 inp->inp_lport = lport;
1326                                 error = in_pcbinshash(inp);
1327                                 INP_HASH_WUNLOCK(pcbinfo);
1328                                 if (error != 0) {
1329                                         inp->inp_lport = 0;
1330                                         error = EAGAIN;
1331                                         goto release;
1332                                 }
1333                                 inp->inp_flags |= INP_ANONPORT;
1334                         } else
1335                                 INP_HASH_WUNLOCK(pcbinfo);
1336                 } else {
1337                         faddr = sin->sin_addr;
1338                         fport = sin->sin_port;
1339                 }
1340         } else {
1341                 INP_LOCK_ASSERT(inp);
1342                 faddr = inp->inp_faddr;
1343                 fport = inp->inp_fport;
1344                 if (faddr.s_addr == INADDR_ANY) {
1345                         error = ENOTCONN;
1346                         goto release;
1347                 }
1348         }
1349
1350         /*
1351          * Calculate data length and get a mbuf for UDP, IP, and possible
1352          * link-layer headers.  Immediate slide the data pointer back forward
1353          * since we won't use that space at this layer.
1354          */
1355         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1356         if (m == NULL) {
1357                 error = ENOBUFS;
1358                 goto release;
1359         }
1360         m->m_data += max_linkhdr;
1361         m->m_len -= max_linkhdr;
1362         m->m_pkthdr.len -= max_linkhdr;
1363
1364         /*
1365          * Fill in mbuf with extended UDP header and addresses and length put
1366          * into network format.
1367          */
1368         ui = mtod(m, struct udpiphdr *);
1369         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1370         ui->ui_v = IPVERSION << 4;
1371         ui->ui_pr = pr;
1372         ui->ui_src = laddr;
1373         ui->ui_dst = faddr;
1374         ui->ui_sport = lport;
1375         ui->ui_dport = fport;
1376         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1377         if (pr == IPPROTO_UDPLITE) {
1378                 struct udpcb *up;
1379                 uint16_t plen;
1380
1381                 up = intoudpcb(inp);
1382                 cscov = up->u_txcslen;
1383                 plen = (u_short)len + sizeof(struct udphdr);
1384                 if (cscov >= plen)
1385                         cscov = 0;
1386                 ui->ui_len = htons(plen);
1387                 ui->ui_ulen = htons(cscov);
1388                 /*
1389                  * For UDP-Lite, checksum coverage length of zero means
1390                  * the entire UDPLite packet is covered by the checksum.
1391                  */
1392                 cscov_partial = (cscov == 0) ? 0 : 1;
1393         }
1394
1395         /*
1396          * Set the Don't Fragment bit in the IP header.
1397          */
1398         if (inp->inp_flags & INP_DONTFRAG) {
1399                 struct ip *ip;
1400
1401                 ip = (struct ip *)&ui->ui_i;
1402                 ip->ip_off |= htons(IP_DF);
1403         }
1404
1405         if (inp->inp_socket->so_options & SO_DONTROUTE)
1406                 ipflags |= IP_ROUTETOIF;
1407         if (inp->inp_socket->so_options & SO_BROADCAST)
1408                 ipflags |= IP_ALLOWBROADCAST;
1409         if (inp->inp_flags & INP_ONESBCAST)
1410                 ipflags |= IP_SENDONES;
1411
1412 #ifdef MAC
1413         mac_inpcb_create_mbuf(inp, m);
1414 #endif
1415
1416         /*
1417          * Set up checksum and output datagram.
1418          */
1419         ui->ui_sum = 0;
1420         if (pr == IPPROTO_UDPLITE) {
1421                 if (inp->inp_flags & INP_ONESBCAST)
1422                         faddr.s_addr = INADDR_BROADCAST;
1423                 if (cscov_partial) {
1424                         if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1425                                 ui->ui_sum = 0xffff;
1426                 } else {
1427                         if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1428                                 ui->ui_sum = 0xffff;
1429                 }
1430         } else if (V_udp_cksum) {
1431                 if (inp->inp_flags & INP_ONESBCAST)
1432                         faddr.s_addr = INADDR_BROADCAST;
1433                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1434                     htons((u_short)len + sizeof(struct udphdr) + pr));
1435                 m->m_pkthdr.csum_flags = CSUM_UDP;
1436                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1437         }
1438         ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1439         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1440         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1441         UDPSTAT_INC(udps_opackets);
1442
1443         /*
1444          * Setup flowid / RSS information for outbound socket.
1445          *
1446          * Once the UDP code decides to set a flowid some other way,
1447          * this allows the flowid to be overridden by userland.
1448          */
1449         if (flowtype != M_HASHTYPE_NONE) {
1450                 m->m_pkthdr.flowid = flowid;
1451                 M_HASHTYPE_SET(m, flowtype);
1452         }
1453 #if defined(ROUTE_MPATH) || defined(RSS)
1454         else if (CALC_FLOWID_OUTBOUND_SENDTO) {
1455                 uint32_t hash_val, hash_type;
1456
1457                 hash_val = fib4_calc_packet_hash(laddr, faddr,
1458                     lport, fport, pr, &hash_type);
1459                 m->m_pkthdr.flowid = hash_val;
1460                 M_HASHTYPE_SET(m, hash_type);
1461         }
1462
1463         /*
1464          * Don't override with the inp cached flowid value.
1465          *
1466          * Depending upon the kind of send being done, the inp
1467          * flowid/flowtype values may actually not be appropriate
1468          * for this particular socket send.
1469          *
1470          * We should either leave the flowid at zero (which is what is
1471          * currently done) or set it to some software generated
1472          * hash value based on the packet contents.
1473          */
1474         ipflags |= IP_NODEFAULTFLOWID;
1475 #endif  /* RSS */
1476
1477         if (pr == IPPROTO_UDPLITE)
1478                 UDPLITE_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1479         else
1480                 UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1481         error = ip_output(m, inp->inp_options,
1482             INP_WLOCKED(inp) ? &inp->inp_route : NULL, ipflags,
1483             inp->inp_moptions, inp);
1484         INP_UNLOCK(inp);
1485         NET_EPOCH_EXIT(et);
1486         return (error);
1487
1488 release:
1489         INP_UNLOCK(inp);
1490         NET_EPOCH_EXIT(et);
1491         m_freem(m);
1492         return (error);
1493 }
1494
1495 pr_abort_t udp_abort;                   /* shared with udp6_usrreq.c */
1496 void
1497 udp_abort(struct socket *so)
1498 {
1499         struct inpcb *inp;
1500         struct inpcbinfo *pcbinfo;
1501
1502         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1503         inp = sotoinpcb(so);
1504         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1505         INP_WLOCK(inp);
1506         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1507                 INP_HASH_WLOCK(pcbinfo);
1508                 in_pcbdisconnect(inp);
1509                 inp->inp_laddr.s_addr = INADDR_ANY;
1510                 INP_HASH_WUNLOCK(pcbinfo);
1511                 soisdisconnected(so);
1512         }
1513         INP_WUNLOCK(inp);
1514 }
1515
1516 static int
1517 udp_attach(struct socket *so, int proto, struct thread *td)
1518 {
1519         static uint32_t udp_flowid;
1520         struct inpcb *inp;
1521         struct inpcbinfo *pcbinfo;
1522         int error;
1523
1524         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1525         inp = sotoinpcb(so);
1526         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1527         error = soreserve(so, udp_sendspace, udp_recvspace);
1528         if (error)
1529                 return (error);
1530         error = in_pcballoc(so, pcbinfo);
1531         if (error)
1532                 return (error);
1533
1534         inp = sotoinpcb(so);
1535         inp->inp_ip_ttl = V_ip_defttl;
1536         inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1537         inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1538
1539         error = udp_newudpcb(inp);
1540         if (error) {
1541                 in_pcbdetach(inp);
1542                 in_pcbfree(inp);
1543                 return (error);
1544         }
1545         INP_WUNLOCK(inp);
1546
1547         return (0);
1548 }
1549 #endif /* INET */
1550
1551 int
1552 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1553 {
1554         struct inpcb *inp;
1555         struct udpcb *up;
1556
1557         KASSERT(so->so_type == SOCK_DGRAM,
1558             ("udp_set_kernel_tunneling: !dgram"));
1559         inp = sotoinpcb(so);
1560         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1561         INP_WLOCK(inp);
1562         up = intoudpcb(inp);
1563         if ((f != NULL || i != NULL) && ((up->u_tun_func != NULL) ||
1564             (up->u_icmp_func != NULL))) {
1565                 INP_WUNLOCK(inp);
1566                 return (EBUSY);
1567         }
1568         up->u_tun_func = f;
1569         up->u_icmp_func = i;
1570         up->u_tun_ctx = ctx;
1571         INP_WUNLOCK(inp);
1572         return (0);
1573 }
1574
1575 #ifdef INET
1576 static int
1577 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1578 {
1579         struct inpcb *inp;
1580         struct inpcbinfo *pcbinfo;
1581         struct sockaddr_in *sinp;
1582         int error;
1583
1584         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1585         inp = sotoinpcb(so);
1586         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1587
1588         sinp = (struct sockaddr_in *)nam;
1589         if (nam->sa_family != AF_INET) {
1590                 /*
1591                  * Preserve compatibility with old programs.
1592                  */
1593                 if (nam->sa_family != AF_UNSPEC ||
1594                     nam->sa_len < offsetof(struct sockaddr_in, sin_zero) ||
1595                     sinp->sin_addr.s_addr != INADDR_ANY)
1596                         return (EAFNOSUPPORT);
1597                 nam->sa_family = AF_INET;
1598         }
1599         if (nam->sa_len != sizeof(struct sockaddr_in))
1600                 return (EINVAL);
1601
1602         INP_WLOCK(inp);
1603         INP_HASH_WLOCK(pcbinfo);
1604         error = in_pcbbind(inp, nam, td->td_ucred);
1605         INP_HASH_WUNLOCK(pcbinfo);
1606         INP_WUNLOCK(inp);
1607         return (error);
1608 }
1609
1610 static void
1611 udp_close(struct socket *so)
1612 {
1613         struct inpcb *inp;
1614         struct inpcbinfo *pcbinfo;
1615
1616         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1617         inp = sotoinpcb(so);
1618         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1619         INP_WLOCK(inp);
1620         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1621                 INP_HASH_WLOCK(pcbinfo);
1622                 in_pcbdisconnect(inp);
1623                 inp->inp_laddr.s_addr = INADDR_ANY;
1624                 INP_HASH_WUNLOCK(pcbinfo);
1625                 soisdisconnected(so);
1626         }
1627         INP_WUNLOCK(inp);
1628 }
1629
1630 static int
1631 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1632 {
1633         struct epoch_tracker et;
1634         struct inpcb *inp;
1635         struct inpcbinfo *pcbinfo;
1636         struct sockaddr_in *sin;
1637         int error;
1638
1639         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1640         inp = sotoinpcb(so);
1641         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1642
1643         sin = (struct sockaddr_in *)nam;
1644         if (sin->sin_family != AF_INET)
1645                 return (EAFNOSUPPORT);
1646         if (sin->sin_len != sizeof(*sin))
1647                 return (EINVAL);
1648
1649         INP_WLOCK(inp);
1650         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1651                 INP_WUNLOCK(inp);
1652                 return (EISCONN);
1653         }
1654         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1655         if (error != 0) {
1656                 INP_WUNLOCK(inp);
1657                 return (error);
1658         }
1659         NET_EPOCH_ENTER(et);
1660         INP_HASH_WLOCK(pcbinfo);
1661         error = in_pcbconnect(inp, nam, td->td_ucred, true);
1662         INP_HASH_WUNLOCK(pcbinfo);
1663         NET_EPOCH_EXIT(et);
1664         if (error == 0)
1665                 soisconnected(so);
1666         INP_WUNLOCK(inp);
1667         return (error);
1668 }
1669
1670 static void
1671 udp_detach(struct socket *so)
1672 {
1673         struct inpcb *inp;
1674         struct udpcb *up;
1675
1676         inp = sotoinpcb(so);
1677         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1678         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1679             ("udp_detach: not disconnected"));
1680         INP_WLOCK(inp);
1681         up = intoudpcb(inp);
1682         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1683         inp->inp_ppcb = NULL;
1684         in_pcbdetach(inp);
1685         in_pcbfree(inp);
1686         udp_discardcb(up);
1687 }
1688
1689 pr_disconnect_t udp_disconnect;         /* shared with udp6_usrreq.c */
1690 int
1691 udp_disconnect(struct socket *so)
1692 {
1693         struct inpcb *inp;
1694         struct inpcbinfo *pcbinfo;
1695
1696         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1697         inp = sotoinpcb(so);
1698         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1699         INP_WLOCK(inp);
1700         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1701                 INP_WUNLOCK(inp);
1702                 return (ENOTCONN);
1703         }
1704         INP_HASH_WLOCK(pcbinfo);
1705         in_pcbdisconnect(inp);
1706         inp->inp_laddr.s_addr = INADDR_ANY;
1707         INP_HASH_WUNLOCK(pcbinfo);
1708         SOCK_LOCK(so);
1709         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1710         SOCK_UNLOCK(so);
1711         INP_WUNLOCK(inp);
1712         return (0);
1713 }
1714
1715 pr_send_t udp_send;                     /* shared with udp6_usrreq.c */
1716 int
1717 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1718     struct mbuf *control, struct thread *td)
1719 {
1720         struct inpcb *inp;
1721         int error;
1722
1723         inp = sotoinpcb(so);
1724         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1725
1726         if (addr != NULL) {
1727                 error = 0;
1728                 if (addr->sa_family != AF_INET)
1729                         error = EAFNOSUPPORT;
1730                 else if (addr->sa_len != sizeof(struct sockaddr_in))
1731                         error = EINVAL;
1732                 if (__predict_false(error != 0)) {
1733                         m_freem(control);
1734                         m_freem(m);
1735                         return (error);
1736                 }
1737         }
1738         return (udp_output(inp, m, addr, control, td, flags));
1739 }
1740 #endif /* INET */
1741
1742 int
1743 udp_shutdown(struct socket *so)
1744 {
1745         struct inpcb *inp;
1746
1747         inp = sotoinpcb(so);
1748         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1749         INP_WLOCK(inp);
1750         socantsendmore(so);
1751         INP_WUNLOCK(inp);
1752         return (0);
1753 }
1754
1755 #ifdef INET
1756 #define UDP_PROTOSW                                                     \
1757         .pr_type =              SOCK_DGRAM,                             \
1758         .pr_flags =             PR_ATOMIC | PR_ADDR | PR_CAPATTACH,     \
1759         .pr_ctloutput =         udp_ctloutput,                          \
1760         .pr_abort =             udp_abort,                              \
1761         .pr_attach =            udp_attach,                             \
1762         .pr_bind =              udp_bind,                               \
1763         .pr_connect =           udp_connect,                            \
1764         .pr_control =           in_control,                             \
1765         .pr_detach =            udp_detach,                             \
1766         .pr_disconnect =        udp_disconnect,                         \
1767         .pr_peeraddr =          in_getpeeraddr,                         \
1768         .pr_send =              udp_send,                               \
1769         .pr_soreceive =         soreceive_dgram,                        \
1770         .pr_sosend =            sosend_dgram,                           \
1771         .pr_shutdown =          udp_shutdown,                           \
1772         .pr_sockaddr =          in_getsockaddr,                         \
1773         .pr_sosetlabel =        in_pcbsosetlabel,                       \
1774         .pr_close =             udp_close
1775
1776 struct protosw udp_protosw = {
1777         .pr_protocol =          IPPROTO_UDP,
1778         UDP_PROTOSW
1779 };
1780
1781 struct protosw udplite_protosw = {
1782         .pr_protocol =          IPPROTO_UDPLITE,
1783         UDP_PROTOSW
1784 };
1785
1786 static void
1787 udp_init(void *arg __unused)
1788 {
1789
1790         IPPROTO_REGISTER(IPPROTO_UDP, udp_input, udp_ctlinput);
1791         IPPROTO_REGISTER(IPPROTO_UDPLITE, udp_input, udplite_ctlinput);
1792 }
1793 SYSINIT(udp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, udp_init, NULL);
1794 #endif /* INET */