sys/netinet/udp_usrreq.c

   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
 131 u_long  udp_sendspace = 9216;           /* really max datagram size */
 132 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 133     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 134
 135 u_long  udp_recvspace = 40 * (1024 +
 136 #ifdef INET6
 137                                       sizeof(struct sockaddr_in6)
 138 #else
 139                                       sizeof(struct sockaddr_in)
 140 #endif
 141                                       );        /* 40 1K datagrams */
 142
 143 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 144     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 145
 146 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
 147 VNET_DEFINE(struct inpcbinfo, udbinfo);
 148 VNET_DEFINE(struct inpcbhead, ulitecb);
 149 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
 150 VNET_DEFINE_STATIC(uma_zone_t, udpcb_zone);
 151 #define V_udpcb_zone                    VNET(udpcb_zone)
 152
 153 #ifndef UDBHASHSIZE
 154 #define UDBHASHSIZE     128
 155 #endif
 156
 157 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);          /* from udp_var.h */
 158 VNET_PCPUSTAT_SYSINIT(udpstat);
 159 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
 160     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 161
 162 #ifdef VIMAGE
 163 VNET_PCPUSTAT_SYSUNINIT(udpstat);
 164 #endif /* VIMAGE */
 165 #ifdef INET
 166 static void     udp_detach(struct socket *so);
 167 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 168                     struct mbuf *, struct thread *, int);
 169 #endif
 170
 171 static void
 172 udp_zone_change(void *tag)
 173 {
 174
 175         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 176         uma_zone_set_max(V_udpcb_zone, maxsockets);
 177 }
 178
 179 static int
 180 udp_inpcb_init(void *mem, int size, int flags)
 181 {
 182         struct inpcb *inp;
 183
 184         inp = mem;
 185         INP_LOCK_INIT(inp, "inp", "udpinp");
 186         return (0);
 187 }
 188
 189 static int
 190 udplite_inpcb_init(void *mem, int size, int flags)
 191 {
 192         struct inpcb *inp;
 193
 194         inp = mem;
 195         INP_LOCK_INIT(inp, "inp", "udpliteinp");
 196         return (0);
 197 }
 198
 199 void
 200 udp_init(void)
 201 {
 202
 203         /*
 204          * For now default to 2-tuple UDP hashing - until the fragment
 205          * reassembly code can also update the flowid.
 206          *
 207          * Once we can calculate the flowid that way and re-establish
 208          * a 4-tuple, flip this to 4-tuple.
 209          */
 210         in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
 211             "udp_inpcb", udp_inpcb_init, IPI_HASHFIELDS_2TUPLE);
 212         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
 213             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
 214         uma_zone_set_max(V_udpcb_zone, maxsockets);
 215         uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
 216         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 217             EVENTHANDLER_PRI_ANY);
 218 }
 219
 220 void
 221 udplite_init(void)
 222 {
 223
 224         in_pcbinfo_init(&V_ulitecbinfo, "udplite", &V_ulitecb, UDBHASHSIZE,
 225             UDBHASHSIZE, "udplite_inpcb", udplite_inpcb_init,
 226             IPI_HASHFIELDS_2TUPLE);
 227 }
 228
 229 /*
 230  * Kernel module interface for updating udpstat.  The argument is an index
 231  * into udpstat treated as an array of u_long.  While this encodes the
 232  * general layout of udpstat into the caller, it doesn't encode its location,
 233  * so that future changes to add, for example, per-CPU stats support won't
 234  * cause binary compatibility problems for kernel modules.
 235  */
 236 void
 237 kmod_udpstat_inc(int statnum)
 238 {
 239
 240         counter_u64_add(VNET(udpstat)[statnum], 1);
 241 }
 242
 243 int
 244 udp_newudpcb(struct inpcb *inp)
 245 {
 246         struct udpcb *up;
 247
 248         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
 249         if (up == NULL)
 250                 return (ENOBUFS);
 251         inp->inp_ppcb = up;
 252         return (0);
 253 }
 254
 255 void
 256 udp_discardcb(struct udpcb *up)
 257 {
 258
 259         uma_zfree(V_udpcb_zone, up);
 260 }
 261
 262 #ifdef VIMAGE
 263 static void
 264 udp_destroy(void *unused __unused)
 265 {
 266
 267         in_pcbinfo_destroy(&V_udbinfo);
 268         uma_zdestroy(V_udpcb_zone);
 269 }
 270 VNET_SYSUNINIT(udp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udp_destroy, NULL);
 271
 272 static void
 273 udplite_destroy(void *unused __unused)
 274 {
 275
 276         in_pcbinfo_destroy(&V_ulitecbinfo);
 277 }
 278 VNET_SYSUNINIT(udplite, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, udplite_destroy,
 279     NULL);
 280 #endif
 281
 282 #ifdef INET
 283 /*
 284  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 285  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 286  * contains the source address.  If the socket ends up being an IPv6 socket,
 287  * udp_append() will convert to a sockaddr_in6 before passing the address
 288  * into the socket code.
 289  *
 290  * In the normal case udp_append() will return 0, indicating that you
 291  * must unlock the inp. However if a tunneling protocol is in place we increment
 292  * the inpcb refcnt and unlock the inp, on return from the tunneling protocol we
 293  * then decrement the reference count. If the inp_rele returns 1, indicating the
 294  * inp is gone, we return that to the caller to tell them *not* to unlock
 295  * the inp. In the case of multi-cast this will cause the distribution
 296  * to stop (though most tunneling protocols known currently do *not* use
 297  * multicast).
 298  */
 299 static int
 300 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 301     struct sockaddr_in *udp_in)
 302 {
 303         struct sockaddr *append_sa;
 304         struct socket *so;
 305         struct mbuf *tmpopts, *opts = NULL;
 306 #ifdef INET6
 307         struct sockaddr_in6 udp_in6;
 308 #endif
 309         struct udpcb *up;
 310
 311         INP_LOCK_ASSERT(inp);
 312
 313         /*
 314          * Engage the tunneling protocol.
 315          */
 316         up = intoudpcb(inp);
 317         if (up->u_tun_func != NULL) {
 318                 in_pcbref(inp);
 319                 INP_RUNLOCK(inp);
 320                 (*up->u_tun_func)(n, off, inp, (struct sockaddr *)&udp_in[0],
 321                     up->u_tun_ctx);
 322                 INP_RLOCK(inp);
 323                 return (in_pcbrele_rlocked(inp));
 324         }
 325
 326         off += sizeof(struct udphdr);
 327
 328 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 329         /* Check AH/ESP integrity. */
 330         if (IPSEC_ENABLED(ipv4) &&
 331             IPSEC_CHECK_POLICY(ipv4, n, inp) != 0) {
 332                 m_freem(n);
 333                 return (0);
 334         }
 335         if (up->u_flags & UF_ESPINUDP) {/* IPSec UDP encaps. */
 336                 if (IPSEC_ENABLED(ipv4) &&
 337                     UDPENCAP_INPUT(n, off, AF_INET) != 0)
 338                         return (0);     /* Consumed. */
 339         }
 340 #endif /* IPSEC */
 341 #ifdef MAC
 342         if (mac_inpcb_check_deliver(inp, n) != 0) {
 343                 m_freem(n);
 344                 return (0);
 345         }
 346 #endif /* MAC */
 347         if (inp->inp_flags & INP_CONTROLOPTS ||
 348             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 349 #ifdef INET6
 350                 if (inp->inp_vflag & INP_IPV6)
 351                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
 352                 else
 353 #endif /* INET6 */
 354                         ip_savecontrol(inp, &opts, ip, n);
 355         }
 356         if ((inp->inp_vflag & INP_IPV4) && (inp->inp_flags2 & INP_ORIGDSTADDR)) {
 357                 tmpopts = sbcreatecontrol((caddr_t)&udp_in[1],
 358                         sizeof(struct sockaddr_in), IP_ORIGDSTADDR, IPPROTO_IP);
 359                 if (tmpopts) {
 360                         if (opts) {
 361                                 tmpopts->m_next = opts;
 362                                 opts = tmpopts;
 363                         } else
 364                                 opts = tmpopts;
 365                 }
 366         }
 367 #ifdef INET6
 368         if (inp->inp_vflag & INP_IPV6) {
 369                 bzero(&udp_in6, sizeof(udp_in6));
 370                 udp_in6.sin6_len = sizeof(udp_in6);
 371                 udp_in6.sin6_family = AF_INET6;
 372                 in6_sin_2_v4mapsin6(&udp_in[0], &udp_in6);
 373                 append_sa = (struct sockaddr *)&udp_in6;
 374         } else
 375 #endif /* INET6 */
 376                 append_sa = (struct sockaddr *)&udp_in[0];
 377         m_adj(n, off);
 378
 379         so = inp->inp_socket;
 380         SOCKBUF_LOCK(&so->so_rcv);
 381         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 382                 SOCKBUF_UNLOCK(&so->so_rcv);
 383                 m_freem(n);
 384                 if (opts)
 385                         m_freem(opts);
 386                 UDPSTAT_INC(udps_fullsock);
 387         } else
 388                 sorwakeup_locked(so);
 389         return (0);
 390 }
 391
 392 int
 393 udp_input(struct mbuf **mp, int *offp, int proto)
 394 {
 395         struct ip *ip;
 396         struct udphdr *uh;
 397         struct ifnet *ifp;
 398         struct inpcb *inp;
 399         uint16_t len, ip_len;
 400         struct inpcbinfo *pcbinfo;
 401         struct ip save_ip;
 402         struct sockaddr_in udp_in[2];
 403         struct mbuf *m;
 404         struct m_tag *fwd_tag;
 405         int cscov_partial, iphlen;
 406
 407         m = *mp;
 408         iphlen = *offp;
 409         ifp = m->m_pkthdr.rcvif;
 410         *mp = NULL;
 411         UDPSTAT_INC(udps_ipackets);
 412
 413         /*
 414          * Strip IP options, if any; should skip this, make available to
 415          * user, and use on returned packets, but we don't yet have a way to
 416          * check the checksum with options still present.
 417          */
 418         if (iphlen > sizeof (struct ip)) {
 419                 ip_stripoptions(m);
 420                 iphlen = sizeof(struct ip);
 421         }
 422
 423         /*
 424          * Get IP and UDP header together in first mbuf.
 425          */
 426         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 427                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
 428                         UDPSTAT_INC(udps_hdrops);
 429                         return (IPPROTO_DONE);
 430                 }
 431         }
 432         ip = mtod(m, struct ip *);
 433         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 434         cscov_partial = (proto == IPPROTO_UDPLITE) ? 1 : 0;
 435
 436         /*
 437          * Destination port of 0 is illegal, based on RFC768.
 438          */
 439         if (uh->uh_dport == 0)
 440                 goto badunlocked;
 441
 442         /*
 443          * Construct sockaddr format source address.  Stuff source address
 444          * and datagram in user buffer.
 445          */
 446         bzero(&udp_in[0], sizeof(struct sockaddr_in) * 2);
 447         udp_in[0].sin_len = sizeof(struct sockaddr_in);
 448         udp_in[0].sin_family = AF_INET;
 449         udp_in[0].sin_port = uh->uh_sport;
 450         udp_in[0].sin_addr = ip->ip_src;
 451         udp_in[1].sin_len = sizeof(struct sockaddr_in);
 452         udp_in[1].sin_family = AF_INET;
 453         udp_in[1].sin_port = uh->uh_dport;
 454         udp_in[1].sin_addr = ip->ip_dst;
 455
 456         /*
 457          * Make mbuf data length reflect UDP length.  If not enough data to
 458          * reflect UDP length, drop.
 459          */
 460         len = ntohs((u_short)uh->uh_ulen);
 461         ip_len = ntohs(ip->ip_len) - iphlen;
 462         if (proto == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
 463                 /* Zero means checksum over the complete packet. */
 464                 if (len == 0)
 465                         len = ip_len;
 466                 cscov_partial = 0;
 467         }
 468         if (ip_len != len) {
 469                 if (len > ip_len || len < sizeof(struct udphdr)) {
 470                         UDPSTAT_INC(udps_badlen);
 471                         goto badunlocked;
 472                 }
 473                 if (proto == IPPROTO_UDP)
 474                         m_adj(m, len - ip_len);
 475         }
 476
 477         /*
 478          * Save a copy of the IP header in case we want restore it for
 479          * sending an ICMP error message in response.
 480          */
 481         if (!V_udp_blackhole)
 482                 save_ip = *ip;
 483         else
 484                 memset(&save_ip, 0, sizeof(save_ip));
 485
 486         /*
 487          * Checksum extended UDP header and data.
 488          */
 489         if (uh->uh_sum) {
 490                 u_short uh_sum;
 491
 492                 if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
 493                     !cscov_partial) {
 494                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 495                                 uh_sum = m->m_pkthdr.csum_data;
 496                         else
 497                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 498                                     ip->ip_dst.s_addr, htonl((u_short)len +
 499                                     m->m_pkthdr.csum_data + proto));
 500                         uh_sum ^= 0xffff;
 501                 } else {
 502                         char b[9];
 503
 504                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 505                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 506                         ((struct ipovly *)ip)->ih_len = (proto == IPPROTO_UDP) ?
 507                             uh->uh_ulen : htons(ip_len);
 508                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 509                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 510                 }
 511                 if (uh_sum) {
 512                         UDPSTAT_INC(udps_badsum);
 513                         m_freem(m);
 514                         return (IPPROTO_DONE);
 515                 }
 516         } else {
 517                 if (proto == IPPROTO_UDP) {
 518                         UDPSTAT_INC(udps_nosum);
 519                 } else {
 520                         /* UDPLite requires a checksum */
 521                         /* XXX: What is the right UDPLite MIB counter here? */
 522                         m_freem(m);
 523                         return (IPPROTO_DONE);
 524                 }
 525         }
 526
 527         pcbinfo = udp_get_inpcbinfo(proto);
 528         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 529             in_broadcast(ip->ip_dst, ifp)) {
 530                 struct inpcb *last;
 531                 struct inpcbhead *pcblist;
 532
 533                 NET_EPOCH_ASSERT();
 534
 535                 pcblist = udp_get_pcblist(proto);
 536                 last = NULL;
 537                 CK_LIST_FOREACH(inp, pcblist, inp_list) {
 538                         if (inp->inp_lport != uh->uh_dport)
 539                                 continue;
 540 #ifdef INET6
 541                         if ((inp->inp_vflag & INP_IPV4) == 0)
 542                                 continue;
 543 #endif
 544                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 545                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 546                                 continue;
 547                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 548                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 549                                 continue;
 550                         if (inp->inp_fport != 0 &&
 551                             inp->inp_fport != uh->uh_sport)
 552                                 continue;
 553
 554                         INP_RLOCK(inp);
 555
 556                         if (__predict_false(inp->inp_flags2 & INP_FREED)) {
 557                                 INP_RUNLOCK(inp);
 558                                 continue;
 559                         }
 560
 561                         /*
 562                          * XXXRW: Because we weren't holding either the inpcb
 563                          * or the hash lock when we checked for a match
 564                          * before, we should probably recheck now that the
 565                          * inpcb lock is held.
 566                          */
 567
 568                         /*
 569                          * Handle socket delivery policy for any-source
 570                          * and source-specific multicast. [RFC3678]
 571                          */
 572                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 573                                 struct ip_moptions      *imo;
 574                                 struct sockaddr_in       group;
 575                                 int                      blocked;
 576
 577                                 imo = inp->inp_moptions;
 578                                 if (imo == NULL) {
 579                                         INP_RUNLOCK(inp);
 580                                         continue;
 581                                 }
 582                                 bzero(&group, sizeof(struct sockaddr_in));
 583                                 group.sin_len = sizeof(struct sockaddr_in);
 584                                 group.sin_family = AF_INET;
 585                                 group.sin_addr = ip->ip_dst;
 586
 587                                 blocked = imo_multi_filter(imo, ifp,
 588                                         (struct sockaddr *)&group,
 589                                         (struct sockaddr *)&udp_in[0]);
 590                                 if (blocked != MCAST_PASS) {
 591                                         if (blocked == MCAST_NOTGMEMBER)
 592                                                 IPSTAT_INC(ips_notmember);
 593                                         if (blocked == MCAST_NOTSMEMBER ||
 594                                             blocked == MCAST_MUTED)
 595                                                 UDPSTAT_INC(udps_filtermcast);
 596                                         INP_RUNLOCK(inp);
 597                                         continue;
 598                                 }
 599                         }
 600                         if (last != NULL) {
 601                                 struct mbuf *n;
 602
 603                                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) !=
 604                                     NULL) {
 605                                         if (proto == IPPROTO_UDPLITE)
 606                                                 UDPLITE_PROBE(receive, NULL, last, ip,
 607                                                     last, uh);
 608                                         else
 609                                                 UDP_PROBE(receive, NULL, last, ip, last,
 610                                                     uh);
 611                                         if (udp_append(last, ip, n, iphlen,
 612                                                 udp_in)) {
 613                                                 goto inp_lost;
 614                                         }
 615                                 }
 616                                 INP_RUNLOCK(last);
 617                         }
 618                         last = inp;
 619                         /*
 620                          * Don't look for additional matches if this one does
 621                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 622                          * socket options set.  This heuristic avoids
 623                          * searching through all pcbs in the common case of a
 624                          * non-shared port.  It assumes that an application
 625                          * will never clear these options after setting them.
 626                          */
 627                         if ((last->inp_socket->so_options &
 628                             (SO_REUSEPORT|SO_REUSEPORT_LB|SO_REUSEADDR)) == 0)
 629                                 break;
 630                 }
 631
 632                 if (last == NULL) {
 633                         /*
 634                          * No matching pcb found; discard datagram.  (No need
 635                          * to send an ICMP Port Unreachable for a broadcast
 636                          * or multicast datgram.)
 637                          */
 638                         UDPSTAT_INC(udps_noportbcast);
 639                         if (inp)
 640                                 INP_RUNLOCK(inp);
 641                         goto badunlocked;
 642                 }
 643                 if (proto == IPPROTO_UDPLITE)
 644                         UDPLITE_PROBE(receive, NULL, last, ip, last, uh);
 645                 else
 646                         UDP_PROBE(receive, NULL, last, ip, last, uh);
 647                 if (udp_append(last, ip, m, iphlen, udp_in) == 0)
 648                         INP_RUNLOCK(last);
 649         inp_lost:
 650                 return (IPPROTO_DONE);
 651         }
 652
 653         /*
 654          * Locate pcb for datagram.
 655          */
 656
 657         /*
 658          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 659          */
 660         if ((m->m_flags & M_IP_NEXTHOP) &&
 661             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 662                 struct sockaddr_in *next_hop;
 663
 664                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 665
 666                 /*
 667                  * Transparently forwarded. Pretend to be the destination.
 668                  * Already got one like this?
 669                  */
 670                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
 671                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
 672                 if (!inp) {
 673                         /*
 674                          * It's new.  Try to find the ambushing socket.
 675                          * Because we've rewritten the destination address,
 676                          * any hardware-generated hash is ignored.
 677                          */
 678                         inp = in_pcblookup(pcbinfo, ip->ip_src,
 679                             uh->uh_sport, next_hop->sin_addr,
 680                             next_hop->sin_port ? htons(next_hop->sin_port) :
 681                             uh->uh_dport, INPLOOKUP_WILDCARD |
 682                             INPLOOKUP_RLOCKPCB, ifp);
 683                 }
 684                 /* Remove the tag from the packet. We don't need it anymore. */
 685                 m_tag_delete(m, fwd_tag);
 686                 m->m_flags &= ~M_IP_NEXTHOP;
 687         } else
 688                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
 689                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
 690                     INPLOOKUP_RLOCKPCB, ifp, m);
 691         if (inp == NULL) {
 692                 if (V_udp_log_in_vain) {
 693                         char src[INET_ADDRSTRLEN];
 694                         char dst[INET_ADDRSTRLEN];
 695
 696                         log(LOG_INFO,
 697                             "Connection attempt to UDP %s:%d from %s:%d\n",
 698                             inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
 699                             inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
 700                 }
 701                 if (proto == IPPROTO_UDPLITE)
 702                         UDPLITE_PROBE(receive, NULL, NULL, ip, NULL, uh);
 703                 else
 704                         UDP_PROBE(receive, NULL, NULL, ip, NULL, uh);
 705                 UDPSTAT_INC(udps_noport);
 706                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 707                         UDPSTAT_INC(udps_noportbcast);
 708                         goto badunlocked;
 709                 }
 710                 if (V_udp_blackhole)
 711                         goto badunlocked;
 712                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 713                         goto badunlocked;
 714                 *ip = save_ip;
 715                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 716                 return (IPPROTO_DONE);
 717         }
 718
 719         /*
 720          * Check the minimum TTL for socket.
 721          */
 722         INP_RLOCK_ASSERT(inp);
 723         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 724                 if (proto == IPPROTO_UDPLITE)
 725                         UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
 726                 else
 727                         UDP_PROBE(receive, NULL, inp, ip, inp, uh);
 728                 INP_RUNLOCK(inp);
 729                 m_freem(m);
 730                 return (IPPROTO_DONE);
 731         }
 732         if (cscov_partial) {
 733                 struct udpcb *up;
 734
 735                 up = intoudpcb(inp);
 736                 if (up->u_rxcslen == 0 || up->u_rxcslen > len) {
 737                         INP_RUNLOCK(inp);
 738                         m_freem(m);
 739                         return (IPPROTO_DONE);
 740                 }
 741         }
 742
 743         if (proto == IPPROTO_UDPLITE)
 744                 UDPLITE_PROBE(receive, NULL, inp, ip, inp, uh);
 745         else
 746                 UDP_PROBE(receive, NULL, inp, ip, inp, uh);
 747         if (udp_append(inp, ip, m, iphlen, udp_in) == 0)
 748                 INP_RUNLOCK(inp);
 749         return (IPPROTO_DONE);
 750
 751 badunlocked:
 752         m_freem(m);
 753         return (IPPROTO_DONE);
 754 }
 755 #endif /* INET */
 756
 757 /*
 758  * Notify a udp user of an asynchronous error; just wake up so that they can
 759  * collect error status.
 760  */
 761 struct inpcb *
 762 udp_notify(struct inpcb *inp, int errno)
 763 {
 764
 765         INP_WLOCK_ASSERT(inp);
 766         if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
 767              errno == EHOSTDOWN) && inp->inp_route.ro_nh) {
 768                 NH_FREE(inp->inp_route.ro_nh);
 769                 inp->inp_route.ro_nh = (struct nhop_object *)NULL;
 770         }
 771
 772         inp->inp_socket->so_error = errno;
 773         sorwakeup(inp->inp_socket);
 774         sowwakeup(inp->inp_socket);
 775         return (inp);
 776 }
 777
 778 #ifdef INET
 779 static void
 780 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
 781     struct inpcbinfo *pcbinfo)
 782 {
 783         struct ip *ip = vip;
 784         struct udphdr *uh;
 785         struct in_addr faddr;
 786         struct inpcb *inp;
 787
 788         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 789         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 790                 return;
 791
 792         if (PRC_IS_REDIRECT(cmd)) {
 793                 /* signal EHOSTDOWN, as it flushes the cached route */
 794                 in_pcbnotifyall(&V_udbinfo, faddr, EHOSTDOWN, udp_notify);
 795                 return;
 796         }
 797
 798         /*
 799          * Hostdead is ugly because it goes linearly through all PCBs.
 800          *
 801          * XXX: We never get this from ICMP, otherwise it makes an excellent
 802          * DoS attack on machines with many connections.
 803          */
 804         if (cmd == PRC_HOSTDEAD)
 805                 ip = NULL;
 806         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 807                 return;
 808         if (ip != NULL) {
 809                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 810                 inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
 811                     ip->ip_src, uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
 812                 if (inp != NULL) {
 813                         INP_WLOCK_ASSERT(inp);
 814                         if (inp->inp_socket != NULL) {
 815                                 udp_notify(inp, inetctlerrmap[cmd]);
 816                         }
 817                         INP_WUNLOCK(inp);
 818                 } else {
 819                         inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
 820                                            ip->ip_src, uh->uh_sport,
 821                                            INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 822                         if (inp != NULL) {
 823                                 struct udpcb *up;
 824                                 void *ctx;
 825                                 udp_tun_icmp_t func;
 826
 827                                 up = intoudpcb(inp);
 828                                 ctx = up->u_tun_ctx;
 829                                 func = up->u_icmp_func;
 830                                 INP_RUNLOCK(inp);
 831                                 if (func != NULL)
 832                                         (*func)(cmd, sa, vip, ctx);
 833                         }
 834                 }
 835         } else
 836                 in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
 837                     udp_notify);
 838 }
 839 void
 840 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 841 {
 842
 843         return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
 844 }
 845
 846 void
 847 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 848 {
 849
 850         return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
 851 }
 852 #endif /* INET */
 853
 854 static int
 855 udp_pcblist(SYSCTL_HANDLER_ARGS)
 856 {
 857         struct xinpgen xig;
 858         struct epoch_tracker et;
 859         struct inpcb *inp;
 860         int error;
 861
 862         if (req->newptr != 0)
 863                 return (EPERM);
 864
 865         if (req->oldptr == 0) {
 866                 int n;
 867
 868                 n = V_udbinfo.ipi_count;
 869                 n += imax(n / 8, 10);
 870                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 871                 return (0);
 872         }
 873
 874         if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
 875                 return (error);
 876
 877         bzero(&xig, sizeof(xig));
 878         xig.xig_len = sizeof xig;
 879         xig.xig_count = V_udbinfo.ipi_count;
 880         xig.xig_gen = V_udbinfo.ipi_gencnt;
 881         xig.xig_sogen = so_gencnt;
 882         error = SYSCTL_OUT(req, &xig, sizeof xig);
 883         if (error)
 884                 return (error);
 885
 886         NET_EPOCH_ENTER(et);
 887         for (inp = CK_LIST_FIRST(V_udbinfo.ipi_listhead);
 888             inp != NULL;
 889             inp = CK_LIST_NEXT(inp, inp_list)) {
 890                 INP_RLOCK(inp);
 891                 if (inp->inp_gencnt <= xig.xig_gen &&
 892                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
 893                         struct xinpcb xi;
 894
 895                         in_pcbtoxinpcb(inp, &xi);
 896                         INP_RUNLOCK(inp);
 897                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 898                         if (error)
 899                                 break;
 900                 } else
 901                         INP_RUNLOCK(inp);
 902         }
 903         NET_EPOCH_EXIT(et);
 904
 905         if (!error) {
 906                 /*
 907                  * Give the user an updated idea of our state.  If the
 908                  * generation differs from what we told her before, she knows
 909                  * that something happened while we were processing this
 910                  * request, and it might be necessary to retry.
 911                  */
 912                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 913                 xig.xig_sogen = so_gencnt;
 914                 xig.xig_count = V_udbinfo.ipi_count;
 915                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 916         }
 917
 918         return (error);
 919 }
 920
 921 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
 922     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
 923     udp_pcblist, "S,xinpcb",
 924     "List of active UDP sockets");
 925
 926 #ifdef INET
 927 static int
 928 udp_getcred(SYSCTL_HANDLER_ARGS)
 929 {
 930         struct xucred xuc;
 931         struct sockaddr_in addrs[2];
 932         struct epoch_tracker et;
 933         struct inpcb *inp;
 934         int error;
 935
 936         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 937         if (error)
 938                 return (error);
 939         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 940         if (error)
 941                 return (error);
 942         NET_EPOCH_ENTER(et);
 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         NET_EPOCH_EXIT(et);
 947         if (inp != NULL) {
 948                 INP_RLOCK_ASSERT(inp);
 949                 if (inp->inp_socket == NULL)
 950                         error = ENOENT;
 951                 if (error == 0)
 952                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 953                 if (error == 0)
 954                         cru2x(inp->inp_cred, &xuc);
 955                 INP_RUNLOCK(inp);
 956         } else
 957                 error = ENOENT;
 958         if (error == 0)
 959                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 960         return (error);
 961 }
 962
 963 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 964     CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
 965     0, 0, udp_getcred, "S,xucred",
 966     "Get the xucred of a UDP connection");
 967 #endif /* INET */
 968
 969 int
 970 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 971 {
 972         struct inpcb *inp;
 973         struct udpcb *up;
 974         int isudplite, error, optval;
 975
 976         error = 0;
 977         isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
 978         inp = sotoinpcb(so);
 979         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 980         INP_WLOCK(inp);
 981         if (sopt->sopt_level != so->so_proto->pr_protocol) {
 982 #ifdef INET6
 983                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 984                         INP_WUNLOCK(inp);
 985                         error = ip6_ctloutput(so, sopt);
 986                 }
 987 #endif
 988 #if defined(INET) && defined(INET6)
 989                 else
 990 #endif
 991 #ifdef INET
 992                 {
 993                         INP_WUNLOCK(inp);
 994                         error = ip_ctloutput(so, sopt);
 995                 }
 996 #endif
 997                 return (error);
 998         }
 999
1000         switch (sopt->sopt_dir) {
1001         case SOPT_SET:
1002                 switch (sopt->sopt_name) {
1003 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1004 #ifdef INET
1005                 case UDP_ENCAP:
1006                         if (!IPSEC_ENABLED(ipv4)) {
1007                                 INP_WUNLOCK(inp);
1008                                 return (ENOPROTOOPT);
1009                         }
1010                         error = UDPENCAP_PCBCTL(inp, sopt);
1011                         break;
1012 #endif /* INET */
1013 #endif /* IPSEC */
1014                 case UDPLITE_SEND_CSCOV:
1015                 case UDPLITE_RECV_CSCOV:
1016                         if (!isudplite) {
1017                                 INP_WUNLOCK(inp);
1018                                 error = ENOPROTOOPT;
1019                                 break;
1020                         }
1021                         INP_WUNLOCK(inp);
1022                         error = sooptcopyin(sopt, &optval, sizeof(optval),
1023                             sizeof(optval));
1024                         if (error != 0)
1025                                 break;
1026                         inp = sotoinpcb(so);
1027                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1028                         INP_WLOCK(inp);
1029                         up = intoudpcb(inp);
1030                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1031                         if ((optval != 0 && optval < 8) || (optval > 65535)) {
1032                                 INP_WUNLOCK(inp);
1033                                 error = EINVAL;
1034                                 break;
1035                         }
1036                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1037                                 up->u_txcslen = optval;
1038                         else
1039                                 up->u_rxcslen = optval;
1040                         INP_WUNLOCK(inp);
1041                         break;
1042                 default:
1043                         INP_WUNLOCK(inp);
1044                         error = ENOPROTOOPT;
1045                         break;
1046                 }
1047                 break;
1048         case SOPT_GET:
1049                 switch (sopt->sopt_name) {
1050 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1051 #ifdef INET
1052                 case UDP_ENCAP:
1053                         if (!IPSEC_ENABLED(ipv4)) {
1054                                 INP_WUNLOCK(inp);
1055                                 return (ENOPROTOOPT);
1056                         }
1057                         error = UDPENCAP_PCBCTL(inp, sopt);
1058                         break;
1059 #endif /* INET */
1060 #endif /* IPSEC */
1061                 case UDPLITE_SEND_CSCOV:
1062                 case UDPLITE_RECV_CSCOV:
1063                         if (!isudplite) {
1064                                 INP_WUNLOCK(inp);
1065                                 error = ENOPROTOOPT;
1066                                 break;
1067                         }
1068                         up = intoudpcb(inp);
1069                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1070                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1071                                 optval = up->u_txcslen;
1072                         else
1073                                 optval = up->u_rxcslen;
1074                         INP_WUNLOCK(inp);
1075                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1076                         break;
1077                 default:
1078                         INP_WUNLOCK(inp);
1079                         error = ENOPROTOOPT;
1080                         break;
1081                 }
1082                 break;
1083         }
1084         return (error);
1085 }
1086
1087 #ifdef INET
1088 #ifdef INET6
1089 /* The logic here is derived from ip6_setpktopt(). See comments there. */
1090 static int
1091 udp_v4mapped_pktinfo(struct cmsghdr *cm, struct sockaddr_in * src,
1092     struct inpcb *inp, int flags)
1093 {
1094         struct ifnet *ifp;
1095         struct in6_pktinfo *pktinfo;
1096         struct in_addr ia;
1097
1098         if ((flags & PRUS_IPV6) == 0)
1099                 return (0);
1100
1101         if (cm->cmsg_level != IPPROTO_IPV6)
1102                 return (0);
1103
1104         if  (cm->cmsg_type != IPV6_2292PKTINFO &&
1105             cm->cmsg_type != IPV6_PKTINFO)
1106                 return (0);
1107
1108         if (cm->cmsg_len !=
1109             CMSG_LEN(sizeof(struct in6_pktinfo)))
1110                 return (EINVAL);
1111
1112         pktinfo = (struct in6_pktinfo *)CMSG_DATA(cm);
1113         if (!IN6_IS_ADDR_V4MAPPED(&pktinfo->ipi6_addr) &&
1114             !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr))
1115                 return (EINVAL);
1116
1117         /* Validate the interface index if specified. */
1118         if (pktinfo->ipi6_ifindex > V_if_index)
1119                 return (ENXIO);
1120
1121         ifp = NULL;
1122         if (pktinfo->ipi6_ifindex) {
1123                 ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
1124                 if (ifp == NULL)
1125                         return (ENXIO);
1126         }
1127         if (ifp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
1128                 ia.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1129                 if (in_ifhasaddr(ifp, ia) == 0)
1130                         return (EADDRNOTAVAIL);
1131         }
1132
1133         bzero(src, sizeof(*src));
1134         src->sin_family = AF_INET;
1135         src->sin_len = sizeof(*src);
1136         src->sin_port = inp->inp_lport;
1137         src->sin_addr.s_addr = pktinfo->ipi6_addr.s6_addr32[3];
1138
1139         return (0);
1140 }
1141 #endif
1142
1143 static int
1144 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
1145     struct mbuf *control, struct thread *td, int flags)
1146 {
1147         struct udpiphdr *ui;
1148         int len = m->m_pkthdr.len;
1149         struct in_addr faddr, laddr;
1150         struct cmsghdr *cm;
1151         struct inpcbinfo *pcbinfo;
1152         struct sockaddr_in *sin, src;
1153         struct epoch_tracker et;
1154         int cscov_partial = 0;
1155         int error = 0;
1156         int ipflags = 0;
1157         u_short fport, lport;
1158         u_char tos;
1159         uint8_t pr;
1160         uint16_t cscov = 0;
1161         uint32_t flowid = 0;
1162         uint8_t flowtype = M_HASHTYPE_NONE;
1163
1164         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1165                 if (control)
1166                         m_freem(control);
1167                 m_freem(m);
1168                 return (EMSGSIZE);
1169         }
1170
1171         src.sin_family = 0;
1172         sin = (struct sockaddr_in *)addr;
1173
1174         /*
1175          * udp_output() may need to temporarily bind or connect the current
1176          * inpcb.  As such, we don't know up front whether we will need the
1177          * pcbinfo lock or not.  Do any work to decide what is needed up
1178          * front before acquiring any locks.
1179          *
1180          * We will need network epoch in either case, to safely lookup into
1181          * pcb hash.
1182          */
1183         if (sin == NULL ||
1184             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0))
1185                 INP_WLOCK(inp);
1186         else
1187                 INP_RLOCK(inp);
1188         NET_EPOCH_ENTER(et);
1189         tos = inp->inp_ip_tos;
1190         if (control != NULL) {
1191                 /*
1192                  * XXX: Currently, we assume all the optional information is
1193                  * stored in a single mbuf.
1194                  */
1195                 if (control->m_next) {
1196                         m_freem(control);
1197                         error = EINVAL;
1198                         goto release;
1199                 }
1200                 for (; control->m_len > 0;
1201                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
1202                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1203                         cm = mtod(control, struct cmsghdr *);
1204                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1205                             || cm->cmsg_len > control->m_len) {
1206                                 error = EINVAL;
1207                                 break;
1208                         }
1209 #ifdef INET6
1210                         error = udp_v4mapped_pktinfo(cm, &src, inp, flags);
1211                         if (error != 0)
1212                                 break;
1213 #endif
1214                         if (cm->cmsg_level != IPPROTO_IP)
1215                                 continue;
1216
1217                         switch (cm->cmsg_type) {
1218                         case IP_SENDSRCADDR:
1219                                 if (cm->cmsg_len !=
1220                                     CMSG_LEN(sizeof(struct in_addr))) {
1221                                         error = EINVAL;
1222                                         break;
1223                                 }
1224                                 bzero(&src, sizeof(src));
1225                                 src.sin_family = AF_INET;
1226                                 src.sin_len = sizeof(src);
1227                                 src.sin_port = inp->inp_lport;
1228                                 src.sin_addr =
1229                                     *(struct in_addr *)CMSG_DATA(cm);
1230                                 break;
1231
1232                         case IP_TOS:
1233                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1234                                         error = EINVAL;
1235                                         break;
1236                                 }
1237                                 tos = *(u_char *)CMSG_DATA(cm);
1238                                 break;
1239
1240                         case IP_FLOWID:
1241                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1242                                         error = EINVAL;
1243                                         break;
1244                                 }
1245                                 flowid = *(uint32_t *) CMSG_DATA(cm);
1246                                 break;
1247
1248                         case IP_FLOWTYPE:
1249                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1250                                         error = EINVAL;
1251                                         break;
1252                                 }
1253                                 flowtype = *(uint32_t *) CMSG_DATA(cm);
1254                                 break;
1255
1256 #ifdef  RSS
1257                         case IP_RSSBUCKETID:
1258                                 if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
1259                                         error = EINVAL;
1260                                         break;
1261                                 }
1262                                 /* This is just a placeholder for now */
1263                                 break;
1264 #endif  /* RSS */
1265                         default:
1266                                 error = ENOPROTOOPT;
1267                                 break;
1268                         }
1269                         if (error)
1270                                 break;
1271                 }
1272                 m_freem(control);
1273         }
1274         if (error)
1275                 goto release;
1276
1277         pr = inp->inp_socket->so_proto->pr_protocol;
1278         pcbinfo = udp_get_inpcbinfo(pr);
1279
1280         /*
1281          * If the IP_SENDSRCADDR control message was specified, override the
1282          * source address for this datagram.  Its use is invalidated if the
1283          * address thus specified is incomplete or clobbers other inpcbs.
1284          */
1285         laddr = inp->inp_laddr;
1286         lport = inp->inp_lport;
1287         if (src.sin_family == AF_INET) {
1288                 INP_HASH_LOCK_ASSERT(pcbinfo);
1289                 if ((lport == 0) ||
1290                     (laddr.s_addr == INADDR_ANY &&
1291                      src.sin_addr.s_addr == INADDR_ANY)) {
1292                         error = EINVAL;
1293                         goto release;
1294                 }
1295                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1296                     &laddr.s_addr, &lport, td->td_ucred);
1297                 if (error)
1298                         goto release;
1299         }
1300
1301         /*
1302          * If a UDP socket has been connected, then a local address/port will
1303          * have been selected and bound.
1304          *
1305          * If a UDP socket has not been connected to, then an explicit
1306          * destination address must be used, in which case a local
1307          * address/port may not have been selected and bound.
1308          */
1309         if (sin != NULL) {
1310                 INP_LOCK_ASSERT(inp);
1311                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1312                         error = EISCONN;
1313                         goto release;
1314                 }
1315
1316                 /*
1317                  * Jail may rewrite the destination address, so let it do
1318                  * that before we use it.
1319                  */
1320                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1321                 if (error)
1322                         goto release;
1323
1324                 /*
1325                  * If a local address or port hasn't yet been selected, or if
1326                  * the destination address needs to be rewritten due to using
1327                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1328                  * to do the heavy lifting.  Once a port is selected, we
1329                  * commit the binding back to the socket; we also commit the
1330                  * binding of the address if in jail.
1331                  *
1332                  * If we already have a valid binding and we're not
1333                  * requesting a destination address rewrite, use a fast path.
1334                  */
1335                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1336                     inp->inp_lport == 0 ||
1337                     sin->sin_addr.s_addr == INADDR_ANY ||
1338                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1339                         INP_HASH_LOCK_ASSERT(pcbinfo);
1340                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1341                             &lport, &faddr.s_addr, &fport, NULL,
1342                             td->td_ucred);
1343                         if (error)
1344                                 goto release;
1345
1346                         /*
1347                          * XXXRW: Why not commit the port if the address is
1348                          * !INADDR_ANY?
1349                          */
1350                         /* Commit the local port if newly assigned. */
1351                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1352                             inp->inp_lport == 0) {
1353                                 INP_WLOCK_ASSERT(inp);
1354                                 /*
1355                                  * Remember addr if jailed, to prevent
1356                                  * rebinding.
1357                                  */
1358                                 if (prison_flag(td->td_ucred, PR_IP4))
1359                                         inp->inp_laddr = laddr;
1360                                 inp->inp_lport = lport;
1361                                 INP_HASH_WLOCK(pcbinfo);
1362                                 error = in_pcbinshash(inp);
1363                                 INP_HASH_WUNLOCK(pcbinfo);
1364                                 if (error != 0) {
1365                                         inp->inp_lport = 0;
1366                                         error = EAGAIN;
1367                                         goto release;
1368                                 }
1369                                 inp->inp_flags |= INP_ANONPORT;
1370                         }
1371                 } else {
1372                         faddr = sin->sin_addr;
1373                         fport = sin->sin_port;
1374                 }
1375         } else {
1376                 INP_LOCK_ASSERT(inp);
1377                 faddr = inp->inp_faddr;
1378                 fport = inp->inp_fport;
1379                 if (faddr.s_addr == INADDR_ANY) {
1380                         error = ENOTCONN;
1381                         goto release;
1382                 }
1383         }
1384
1385         /*
1386          * Calculate data length and get a mbuf for UDP, IP, and possible
1387          * link-layer headers.  Immediate slide the data pointer back forward
1388          * since we won't use that space at this layer.
1389          */
1390         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1391         if (m == NULL) {
1392                 error = ENOBUFS;
1393                 goto release;
1394         }
1395         m->m_data += max_linkhdr;
1396         m->m_len -= max_linkhdr;
1397         m->m_pkthdr.len -= max_linkhdr;
1398
1399         /*
1400          * Fill in mbuf with extended UDP header and addresses and length put
1401          * into network format.
1402          */
1403         ui = mtod(m, struct udpiphdr *);
1404         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1405         ui->ui_v = IPVERSION << 4;
1406         ui->ui_pr = pr;
1407         ui->ui_src = laddr;
1408         ui->ui_dst = faddr;
1409         ui->ui_sport = lport;
1410         ui->ui_dport = fport;
1411         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1412         if (pr == IPPROTO_UDPLITE) {
1413                 struct udpcb *up;
1414                 uint16_t plen;
1415
1416                 up = intoudpcb(inp);
1417                 cscov = up->u_txcslen;
1418                 plen = (u_short)len + sizeof(struct udphdr);
1419                 if (cscov >= plen)
1420                         cscov = 0;
1421                 ui->ui_len = htons(plen);
1422                 ui->ui_ulen = htons(cscov);
1423                 /*
1424                  * For UDP-Lite, checksum coverage length of zero means
1425                  * the entire UDPLite packet is covered by the checksum.
1426                  */
1427                 cscov_partial = (cscov == 0) ? 0 : 1;
1428         }
1429
1430         /*
1431          * Set the Don't Fragment bit in the IP header.
1432          */
1433         if (inp->inp_flags & INP_DONTFRAG) {
1434                 struct ip *ip;
1435
1436                 ip = (struct ip *)&ui->ui_i;
1437                 ip->ip_off |= htons(IP_DF);
1438         }
1439
1440         if (inp->inp_socket->so_options & SO_DONTROUTE)
1441                 ipflags |= IP_ROUTETOIF;
1442         if (inp->inp_socket->so_options & SO_BROADCAST)
1443                 ipflags |= IP_ALLOWBROADCAST;
1444         if (inp->inp_flags & INP_ONESBCAST)
1445                 ipflags |= IP_SENDONES;
1446
1447 #ifdef MAC
1448         mac_inpcb_create_mbuf(inp, m);
1449 #endif
1450
1451         /*
1452          * Set up checksum and output datagram.
1453          */
1454         ui->ui_sum = 0;
1455         if (pr == IPPROTO_UDPLITE) {
1456                 if (inp->inp_flags & INP_ONESBCAST)
1457                         faddr.s_addr = INADDR_BROADCAST;
1458                 if (cscov_partial) {
1459                         if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1460                                 ui->ui_sum = 0xffff;
1461                 } else {
1462                         if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1463                                 ui->ui_sum = 0xffff;
1464                 }
1465         } else if (V_udp_cksum) {
1466                 if (inp->inp_flags & INP_ONESBCAST)
1467                         faddr.s_addr = INADDR_BROADCAST;
1468                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1469                     htons((u_short)len + sizeof(struct udphdr) + pr));
1470                 m->m_pkthdr.csum_flags = CSUM_UDP;
1471                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1472         }
1473         ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1474         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1475         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1476         UDPSTAT_INC(udps_opackets);
1477
1478         /*
1479          * Setup flowid / RSS information for outbound socket.
1480          *
1481          * Once the UDP code decides to set a flowid some other way,
1482          * this allows the flowid to be overridden by userland.
1483          */
1484         if (flowtype != M_HASHTYPE_NONE) {
1485                 m->m_pkthdr.flowid = flowid;
1486                 M_HASHTYPE_SET(m, flowtype);
1487         }
1488 #if defined(ROUTE_MPATH) || defined(RSS)
1489         else if (CALC_FLOWID_OUTBOUND_SENDTO) {
1490                 uint32_t hash_val, hash_type;
1491
1492                 hash_val = fib4_calc_packet_hash(laddr, faddr,
1493                     lport, fport, pr, &hash_type);
1494                 m->m_pkthdr.flowid = hash_val;
1495                 M_HASHTYPE_SET(m, hash_type);
1496         }
1497
1498         /*
1499          * Don't override with the inp cached flowid value.
1500          *
1501          * Depending upon the kind of send being done, the inp
1502          * flowid/flowtype values may actually not be appropriate
1503          * for this particular socket send.
1504          *
1505          * We should either leave the flowid at zero (which is what is
1506          * currently done) or set it to some software generated
1507          * hash value based on the packet contents.
1508          */
1509         ipflags |= IP_NODEFAULTFLOWID;
1510 #endif  /* RSS */
1511
1512         if (pr == IPPROTO_UDPLITE)
1513                 UDPLITE_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1514         else
1515                 UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1516         error = ip_output(m, inp->inp_options,
1517             INP_WLOCKED(inp) ? &inp->inp_route : NULL, ipflags,
1518             inp->inp_moptions, inp);
1519         INP_UNLOCK(inp);
1520         NET_EPOCH_EXIT(et);
1521         return (error);
1522
1523 release:
1524         INP_UNLOCK(inp);
1525         NET_EPOCH_EXIT(et);
1526         m_freem(m);
1527         return (error);
1528 }
1529
1530 static void
1531 udp_abort(struct socket *so)
1532 {
1533         struct inpcb *inp;
1534         struct inpcbinfo *pcbinfo;
1535
1536         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1537         inp = sotoinpcb(so);
1538         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1539         INP_WLOCK(inp);
1540         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1541                 INP_HASH_WLOCK(pcbinfo);
1542                 in_pcbdisconnect(inp);
1543                 inp->inp_laddr.s_addr = INADDR_ANY;
1544                 INP_HASH_WUNLOCK(pcbinfo);
1545                 soisdisconnected(so);
1546         }
1547         INP_WUNLOCK(inp);
1548 }
1549
1550 static int
1551 udp_attach(struct socket *so, int proto, struct thread *td)
1552 {
1553         static uint32_t udp_flowid;
1554         struct inpcb *inp;
1555         struct inpcbinfo *pcbinfo;
1556         int error;
1557
1558         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1559         inp = sotoinpcb(so);
1560         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1561         error = soreserve(so, udp_sendspace, udp_recvspace);
1562         if (error)
1563                 return (error);
1564         INP_INFO_WLOCK(pcbinfo);
1565         error = in_pcballoc(so, pcbinfo);
1566         if (error) {
1567                 INP_INFO_WUNLOCK(pcbinfo);
1568                 return (error);
1569         }
1570
1571         inp = sotoinpcb(so);
1572         inp->inp_vflag |= INP_IPV4;
1573         inp->inp_ip_ttl = V_ip_defttl;
1574         inp->inp_flowid = atomic_fetchadd_int(&udp_flowid, 1);
1575         inp->inp_flowtype = M_HASHTYPE_OPAQUE;
1576
1577         error = udp_newudpcb(inp);
1578         if (error) {
1579                 in_pcbdetach(inp);
1580                 in_pcbfree(inp);
1581                 INP_INFO_WUNLOCK(pcbinfo);
1582                 return (error);
1583         }
1584
1585         INP_WUNLOCK(inp);
1586         INP_INFO_WUNLOCK(pcbinfo);
1587         return (0);
1588 }
1589 #endif /* INET */
1590
1591 int
1592 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f, udp_tun_icmp_t i, void *ctx)
1593 {
1594         struct inpcb *inp;
1595         struct udpcb *up;
1596
1597         KASSERT(so->so_type == SOCK_DGRAM,
1598             ("udp_set_kernel_tunneling: !dgram"));
1599         inp = sotoinpcb(so);
1600         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1601         INP_WLOCK(inp);
1602         up = intoudpcb(inp);
1603         if ((up->u_tun_func != NULL) ||
1604             (up->u_icmp_func != NULL)) {
1605                 INP_WUNLOCK(inp);
1606                 return (EBUSY);
1607         }
1608         up->u_tun_func = f;
1609         up->u_icmp_func = i;
1610         up->u_tun_ctx = ctx;
1611         INP_WUNLOCK(inp);
1612         return (0);
1613 }
1614
1615 #ifdef INET
1616 static int
1617 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1618 {
1619         struct inpcb *inp;
1620         struct inpcbinfo *pcbinfo;
1621         int error;
1622
1623         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1624         inp = sotoinpcb(so);
1625         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1626         INP_WLOCK(inp);
1627         INP_HASH_WLOCK(pcbinfo);
1628         error = in_pcbbind(inp, nam, td->td_ucred);
1629         INP_HASH_WUNLOCK(pcbinfo);
1630         INP_WUNLOCK(inp);
1631         return (error);
1632 }
1633
1634 static void
1635 udp_close(struct socket *so)
1636 {
1637         struct inpcb *inp;
1638         struct inpcbinfo *pcbinfo;
1639
1640         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1641         inp = sotoinpcb(so);
1642         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1643         INP_WLOCK(inp);
1644         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1645                 INP_HASH_WLOCK(pcbinfo);
1646                 in_pcbdisconnect(inp);
1647                 inp->inp_laddr.s_addr = INADDR_ANY;
1648                 INP_HASH_WUNLOCK(pcbinfo);
1649                 soisdisconnected(so);
1650         }
1651         INP_WUNLOCK(inp);
1652 }
1653
1654 static int
1655 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1656 {
1657         struct epoch_tracker et;
1658         struct inpcb *inp;
1659         struct inpcbinfo *pcbinfo;
1660         struct sockaddr_in *sin;
1661         int error;
1662
1663         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1664         inp = sotoinpcb(so);
1665         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1666         INP_WLOCK(inp);
1667         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1668                 INP_WUNLOCK(inp);
1669                 return (EISCONN);
1670         }
1671         sin = (struct sockaddr_in *)nam;
1672         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1673         if (error != 0) {
1674                 INP_WUNLOCK(inp);
1675                 return (error);
1676         }
1677         NET_EPOCH_ENTER(et);
1678         INP_HASH_WLOCK(pcbinfo);
1679         error = in_pcbconnect(inp, nam, td->td_ucred);
1680         INP_HASH_WUNLOCK(pcbinfo);
1681         NET_EPOCH_EXIT(et);
1682         if (error == 0)
1683                 soisconnected(so);
1684         INP_WUNLOCK(inp);
1685         return (error);
1686 }
1687
1688 static void
1689 udp_detach(struct socket *so)
1690 {
1691         struct inpcb *inp;
1692         struct inpcbinfo *pcbinfo;
1693         struct udpcb *up;
1694
1695         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1696         inp = sotoinpcb(so);
1697         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1698         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1699             ("udp_detach: not disconnected"));
1700         INP_INFO_WLOCK(pcbinfo);
1701         INP_WLOCK(inp);
1702         up = intoudpcb(inp);
1703         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1704         inp->inp_ppcb = NULL;
1705         in_pcbdetach(inp);
1706         in_pcbfree(inp);
1707         INP_INFO_WUNLOCK(pcbinfo);
1708         udp_discardcb(up);
1709 }
1710
1711 static int
1712 udp_disconnect(struct socket *so)
1713 {
1714         struct inpcb *inp;
1715         struct inpcbinfo *pcbinfo;
1716
1717         pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
1718         inp = sotoinpcb(so);
1719         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1720         INP_WLOCK(inp);
1721         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1722                 INP_WUNLOCK(inp);
1723                 return (ENOTCONN);
1724         }
1725         INP_HASH_WLOCK(pcbinfo);
1726         in_pcbdisconnect(inp);
1727         inp->inp_laddr.s_addr = INADDR_ANY;
1728         INP_HASH_WUNLOCK(pcbinfo);
1729         SOCK_LOCK(so);
1730         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1731         SOCK_UNLOCK(so);
1732         INP_WUNLOCK(inp);
1733         return (0);
1734 }
1735
1736 static int
1737 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1738     struct mbuf *control, struct thread *td)
1739 {
1740         struct inpcb *inp;
1741
1742         inp = sotoinpcb(so);
1743         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1744         return (udp_output(inp, m, addr, control, td, flags));
1745 }
1746 #endif /* INET */
1747
1748 int
1749 udp_shutdown(struct socket *so)
1750 {
1751         struct inpcb *inp;
1752
1753         inp = sotoinpcb(so);
1754         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1755         INP_WLOCK(inp);
1756         socantsendmore(so);
1757         INP_WUNLOCK(inp);
1758         return (0);
1759 }
1760
1761 #ifdef INET
1762 struct pr_usrreqs udp_usrreqs = {
1763         .pru_abort =            udp_abort,
1764         .pru_attach =           udp_attach,
1765         .pru_bind =             udp_bind,
1766         .pru_connect =          udp_connect,
1767         .pru_control =          in_control,
1768         .pru_detach =           udp_detach,
1769         .pru_disconnect =       udp_disconnect,
1770         .pru_peeraddr =         in_getpeeraddr,
1771         .pru_send =             udp_send,
1772         .pru_soreceive =        soreceive_dgram,
1773         .pru_sosend =           sosend_dgram,
1774         .pru_shutdown =         udp_shutdown,
1775         .pru_sockaddr =         in_getsockaddr,
1776         .pru_sosetlabel =       in_pcbsosetlabel,
1777         .pru_close =            udp_close,
1778 };
1779 #endif /* INET */