sys/netinet/udp_usrreq.c

   1 /*
   2  * Copyright (c) 2004 Jeffrey M. Hsu.  All rights reserved.
   3  * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to The DragonFly Project
   6  * by Jeffrey M. Hsu.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of The DragonFly Project nor the names of its
  17  *    contributors may be used to endorse or promote products derived
  18  *    from this software without specific, prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  67  * $FreeBSD: src/sys/netinet/udp_usrreq.c,v 1.64.2.18 2003/01/24 05:11:34 sam Exp $
  68  * $DragonFly: src/sys/netinet/udp_usrreq.c,v 1.42 2007/04/22 01:13:14 dillon Exp $
  69  */
  70
  71 #include "opt_ipsec.h"
  72 #include "opt_inet6.h"
  73
  74 #include <sys/param.h>
  75 #include <sys/systm.h>
  76 #include <sys/kernel.h>
  77 #include <sys/malloc.h>
  78 #include <sys/mbuf.h>
  79 #include <sys/domain.h>
  80 #include <sys/proc.h>
  81 #include <sys/protosw.h>
  82 #include <sys/socket.h>
  83 #include <sys/socketvar.h>
  84 #include <sys/sysctl.h>
  85 #include <sys/syslog.h>
  86 #include <sys/thread2.h>
  87 #include <sys/in_cksum.h>
  88
  89 #include <machine/stdarg.h>
  90
  91 #include <vm/vm_zone.h>
  92
  93 #include <net/if.h>
  94 #include <net/route.h>
  95
  96 #include <netinet/in.h>
  97 #include <netinet/in_systm.h>
  98 #include <netinet/ip.h>
  99 #ifdef INET6
 100 #include <netinet/ip6.h>
 101 #endif
 102 #include <netinet/in_pcb.h>
 103 #include <netinet/in_var.h>
 104 #include <netinet/ip_var.h>
 105 #ifdef INET6
 106 #include <netinet6/ip6_var.h>
 107 #endif
 108 #include <netinet/ip_icmp.h>
 109 #include <netinet/icmp_var.h>
 110 #include <netinet/udp.h>
 111 #include <netinet/udp_var.h>
 112
 113 #ifdef FAST_IPSEC
 114 #include <netproto/ipsec/ipsec.h>
 115 #endif
 116
 117 #ifdef IPSEC
 118 #include <netinet6/ipsec.h>
 119 #endif
 120
 121 /*
 122  * UDP protocol implementation.
 123  * Per RFC 768, August, 1980.
 124  */
 125 #ifndef COMPAT_42
 126 static int      udpcksum = 1;
 127 #else
 128 static int      udpcksum = 0;           /* XXX */
 129 #endif
 130 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
 131                 &udpcksum, 0, "");
 132
 133 int     log_in_vain = 0;
 134 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 135     &log_in_vain, 0, "Log all incoming UDP packets");
 136
 137 static int      blackhole = 0;
 138 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 139         &blackhole, 0, "Do not send port unreachables for refused connects");
 140
 141 static int      strict_mcast_mship = 1;
 142 SYSCTL_INT(_net_inet_udp, OID_AUTO, strict_mcast_mship, CTLFLAG_RW,
 143         &strict_mcast_mship, 0, "Only send multicast to member sockets");
 144
 145 struct  inpcbinfo udbinfo;
 146
 147 #ifndef UDBHASHSIZE
 148 #define UDBHASHSIZE 16
 149 #endif
 150
 151 struct  udpstat udpstat;        /* from udp_var.h */
 152 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
 153     &udpstat, udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 154
 155 static struct   sockaddr_in udp_in = { sizeof udp_in, AF_INET };
 156 #ifdef INET6
 157 struct udp_in6 {
 158         struct sockaddr_in6     uin6_sin;
 159         u_char                  uin6_init_done : 1;
 160 } udp_in6 = {
 161         { sizeof udp_in6.uin6_sin, AF_INET6 },
 162         0
 163 };
 164 struct udp_ip6 {
 165         struct ip6_hdr          uip6_ip6;
 166         u_char                  uip6_init_done : 1;
 167 } udp_ip6;
 168 #endif /* INET6 */
 169
 170 static void udp_append (struct inpcb *last, struct ip *ip,
 171                             struct mbuf *n, int off);
 172 #ifdef INET6
 173 static void ip_2_ip6_hdr (struct ip6_hdr *ip6, struct ip *ip);
 174 #endif
 175
 176 static int udp_detach (struct socket *so);
 177 static  int udp_output (struct inpcb *, struct mbuf *, struct sockaddr *,
 178                             struct mbuf *, struct thread *);
 179
 180 void
 181 udp_init(void)
 182 {
 183         in_pcbinfo_init(&udbinfo);
 184         udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask);
 185         udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB,
 186                                         &udbinfo.porthashmask);
 187         udbinfo.wildcardhashbase = hashinit(UDBHASHSIZE, M_PCB,
 188                                             &udbinfo.wildcardhashmask);
 189         udbinfo.ipi_zone = zinit("udpcb", sizeof(struct inpcb), maxsockets,
 190                                  ZONE_INTERRUPT, 0);
 191         udp_thread_init();
 192 }
 193
 194 /*
 195  * Check multicast packets to make sure they are only sent to sockets with
 196  * multicast memberships for the packet's destination address and arrival
 197  * interface.  Multicast packets to multicast-unaware sockets are also
 198  * disallowed.
 199  *
 200  * Returns 0 if the packet is acceptable, -1 if it is not.
 201  */
 202 static __inline int
 203 check_multicast_membership(struct ip *ip, struct inpcb *inp, struct mbuf *m)
 204 {
 205         int mshipno;
 206         struct ip_moptions *mopt;
 207
 208         if (strict_mcast_mship == 0 ||
 209             !IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 210                 return (0);
 211         }
 212         mopt = inp->inp_moptions;
 213         if (mopt == NULL)
 214                 return (-1);
 215         for (mshipno = 0; mshipno <= mopt->imo_num_memberships; ++mshipno) {
 216                 struct in_multi *maddr = mopt->imo_membership[mshipno];
 217
 218                 if (ip->ip_dst.s_addr == maddr->inm_addr.s_addr &&
 219                     m->m_pkthdr.rcvif == maddr->inm_ifp) {
 220                         return (0);
 221                 }
 222         }
 223         return (-1);
 224 }
 225
 226 void
 227 udp_input(struct mbuf *m, ...)
 228 {
 229         int iphlen;
 230         struct ip *ip;
 231         struct udphdr *uh;
 232         struct inpcb *inp;
 233         struct mbuf *opts = NULL;
 234         int len, off, proto;
 235         struct ip save_ip;
 236         struct sockaddr *append_sa;
 237         __va_list ap;
 238
 239         __va_start(ap, m);
 240         off = __va_arg(ap, int);
 241         proto = __va_arg(ap, int);
 242         __va_end(ap);
 243
 244         iphlen = off;
 245         udpstat.udps_ipackets++;
 246
 247         /*
 248          * Strip IP options, if any; should skip this,
 249          * make available to user, and use on returned packets,
 250          * but we don't yet have a way to check the checksum
 251          * with options still present.
 252          */
 253         if (iphlen > sizeof(struct ip)) {
 254                 ip_stripoptions(m);
 255                 iphlen = sizeof(struct ip);
 256         }
 257
 258         /*
 259          * IP and UDP headers are together in first mbuf.
 260          * Already checked and pulled up in ip_demux().
 261          */
 262         KASSERT(m->m_len >= iphlen + sizeof(struct udphdr),
 263             ("UDP header not in one mbuf"));
 264
 265         ip = mtod(m, struct ip *);
 266         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 267
 268         /* destination port of 0 is illegal, based on RFC768. */
 269         if (uh->uh_dport == 0)
 270                 goto bad;
 271
 272         /*
 273          * Make mbuf data length reflect UDP length.
 274          * If not enough data to reflect UDP length, drop.
 275          */
 276         len = ntohs((u_short)uh->uh_ulen);
 277         if (ip->ip_len != len) {
 278                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 279                         udpstat.udps_badlen++;
 280                         goto bad;
 281                 }
 282                 m_adj(m, len - ip->ip_len);
 283                 /* ip->ip_len = len; */
 284         }
 285         /*
 286          * Save a copy of the IP header in case we want restore it
 287          * for sending an ICMP error message in response.
 288          */
 289         save_ip = *ip;
 290
 291         /*
 292          * Checksum extended UDP header and data.
 293          */
 294         if (uh->uh_sum) {
 295                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 296                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 297                                 uh->uh_sum = m->m_pkthdr.csum_data;
 298                         else
 299                                 uh->uh_sum = in_pseudo(ip->ip_src.s_addr,
 300                                     ip->ip_dst.s_addr, htonl((u_short)len +
 301                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 302                         uh->uh_sum ^= 0xffff;
 303                 } else {
 304                         char b[9];
 305
 306                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 307                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 308                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 309                         uh->uh_sum = in_cksum(m, len + sizeof(struct ip));
 310                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 311                 }
 312                 if (uh->uh_sum) {
 313                         udpstat.udps_badsum++;
 314                         m_freem(m);
 315                         return;
 316                 }
 317         } else
 318                 udpstat.udps_nosum++;
 319
 320         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 321             in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
 322                 struct inpcb *last;
 323
 324                 /*
 325                  * Deliver a multicast or broadcast datagram to *all* sockets
 326                  * for which the local and remote addresses and ports match
 327                  * those of the incoming datagram.  This allows more than
 328                  * one process to receive multi/broadcasts on the same port.
 329                  * (This really ought to be done for unicast datagrams as
 330                  * well, but that would cause problems with existing
 331                  * applications that open both address-specific sockets and
 332                  * a wildcard socket listening to the same port -- they would
 333                  * end up receiving duplicates of every unicast datagram.
 334                  * Those applications open the multiple sockets to overcome an
 335                  * inadequacy of the UDP socket interface, but for backwards
 336                  * compatibility we avoid the problem here rather than
 337                  * fixing the interface.  Maybe 4.5BSD will remedy this?)
 338                  */
 339
 340                 /*
 341                  * Construct sockaddr format source address.
 342                  */
 343                 udp_in.sin_port = uh->uh_sport;
 344                 udp_in.sin_addr = ip->ip_src;
 345                 /*
 346                  * Locate pcb(s) for datagram.
 347                  * (Algorithm copied from raw_intr().)
 348                  */
 349                 last = NULL;
 350 #ifdef INET6
 351                 udp_in6.uin6_init_done = udp_ip6.uip6_init_done = 0;
 352 #endif
 353                 LIST_FOREACH(inp, &udbinfo.pcblisthead, inp_list) {
 354                         if (inp->inp_flags & INP_PLACEMARKER)
 355                                 continue;
 356 #ifdef INET6
 357                         if (!(inp->inp_vflag & INP_IPV4))
 358                                 continue;
 359 #endif
 360                         if (inp->inp_lport != uh->uh_dport)
 361                                 continue;
 362                         if (inp->inp_laddr.s_addr != INADDR_ANY) {
 363                                 if (inp->inp_laddr.s_addr !=
 364                                     ip->ip_dst.s_addr)
 365                                         continue;
 366                         }
 367                         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 368                                 if (inp->inp_faddr.s_addr !=
 369                                     ip->ip_src.s_addr ||
 370                                     inp->inp_fport != uh->uh_sport)
 371                                         continue;
 372                         }
 373
 374                         if (check_multicast_membership(ip, inp, m) < 0)
 375                                 continue;
 376
 377                         if (last != NULL) {
 378                                 struct mbuf *n;
 379
 380 #ifdef IPSEC
 381                                 /* check AH/ESP integrity. */
 382                                 if (ipsec4_in_reject_so(m, last->inp_socket))
 383                                         ipsecstat.in_polvio++;
 384                                         /* do not inject data to pcb */
 385                                 else
 386 #endif /*IPSEC*/
 387 #ifdef FAST_IPSEC
 388                                 /* check AH/ESP integrity. */
 389                                 if (ipsec4_in_reject(m, last))
 390                                         ;
 391                                 else
 392 #endif /*FAST_IPSEC*/
 393                                 if ((n = m_copypacket(m, MB_DONTWAIT)) != NULL)
 394                                         udp_append(last, ip, n,
 395                                                    iphlen +
 396                                                    sizeof(struct udphdr));
 397                         }
 398                         last = inp;
 399                         /*
 400                          * Don't look for additional matches if this one does
 401                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 402                          * socket options set.  This heuristic avoids searching
 403                          * through all pcbs in the common case of a non-shared
 404                          * port.  It * assumes that an application will never
 405                          * clear these options after setting them.
 406                          */
 407                         if (!(last->inp_socket->so_options &
 408                             (SO_REUSEPORT | SO_REUSEADDR)))
 409                                 break;
 410                 }
 411
 412                 if (last == NULL) {
 413                         /*
 414                          * No matching pcb found; discard datagram.
 415                          * (No need to send an ICMP Port Unreachable
 416                          * for a broadcast or multicast datgram.)
 417                          */
 418                         udpstat.udps_noportbcast++;
 419                         goto bad;
 420                 }
 421 #ifdef IPSEC
 422                 /* check AH/ESP integrity. */
 423                 if (ipsec4_in_reject_so(m, last->inp_socket)) {
 424                         ipsecstat.in_polvio++;
 425                         goto bad;
 426                 }
 427 #endif /*IPSEC*/
 428 #ifdef FAST_IPSEC
 429                 /* check AH/ESP integrity. */
 430                 if (ipsec4_in_reject(m, last))
 431                         goto bad;
 432 #endif /*FAST_IPSEC*/
 433                 udp_append(last, ip, m, iphlen + sizeof(struct udphdr));
 434                 return;
 435         }
 436         /*
 437          * Locate pcb for datagram.
 438          */
 439         inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
 440             ip->ip_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 441         if (inp == NULL) {
 442                 if (log_in_vain) {
 443                         char buf[sizeof "aaa.bbb.ccc.ddd"];
 444
 445                         strcpy(buf, inet_ntoa(ip->ip_dst));
 446                         log(LOG_INFO,
 447                             "Connection attempt to UDP %s:%d from %s:%d\n",
 448                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 449                             ntohs(uh->uh_sport));
 450                 }
 451                 udpstat.udps_noport++;
 452                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 453                         udpstat.udps_noportbcast++;
 454                         goto bad;
 455                 }
 456                 if (blackhole)
 457                         goto bad;
 458 #ifdef ICMP_BANDLIM
 459                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 460                         goto bad;
 461 #endif
 462                 *ip = save_ip;
 463                 ip->ip_len += iphlen;
 464                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 465                 return;
 466         }
 467 #ifdef IPSEC
 468         if (ipsec4_in_reject_so(m, inp->inp_socket)) {
 469                 ipsecstat.in_polvio++;
 470                 goto bad;
 471         }
 472 #endif /*IPSEC*/
 473 #ifdef FAST_IPSEC
 474         if (ipsec4_in_reject(m, inp))
 475                 goto bad;
 476 #endif /*FAST_IPSEC*/
 477         /*
 478          * Check the minimum TTL for socket.
 479          */
 480         if (ip->ip_ttl < inp->inp_ip_minttl)
 481                 goto bad;
 482
 483         /*
 484          * Construct sockaddr format source address.
 485          * Stuff source address and datagram in user buffer.
 486          */
 487         udp_in.sin_port = uh->uh_sport;
 488         udp_in.sin_addr = ip->ip_src;
 489         if ((inp->inp_flags & INP_CONTROLOPTS) ||
 490             (inp->inp_socket->so_options & SO_TIMESTAMP)) {
 491 #ifdef INET6
 492                 if (inp->inp_vflag & INP_IPV6) {
 493                         int savedflags;
 494
 495                         ip_2_ip6_hdr(&udp_ip6.uip6_ip6, ip);
 496                         savedflags = inp->inp_flags;
 497                         inp->inp_flags &= ~INP_UNMAPPABLEOPTS;
 498                         ip6_savecontrol(inp, &opts, &udp_ip6.uip6_ip6, m);
 499                         inp->inp_flags = savedflags;
 500                 } else
 501 #endif
 502                 ip_savecontrol(inp, &opts, ip, m);
 503         }
 504         m_adj(m, iphlen + sizeof(struct udphdr));
 505 #ifdef INET6
 506         if (inp->inp_vflag & INP_IPV6) {
 507                 in6_sin_2_v4mapsin6(&udp_in, &udp_in6.uin6_sin);
 508                 append_sa = (struct sockaddr *)&udp_in6;
 509         } else
 510 #endif
 511                 append_sa = (struct sockaddr *)&udp_in;
 512         if (ssb_appendaddr(&inp->inp_socket->so_rcv, append_sa, m, opts) == 0) {
 513                 udpstat.udps_fullsock++;
 514                 goto bad;
 515         }
 516         sorwakeup(inp->inp_socket);
 517         return;
 518 bad:
 519         m_freem(m);
 520         if (opts)
 521                 m_freem(opts);
 522         return;
 523 }
 524
 525 #ifdef INET6
 526 static void
 527 ip_2_ip6_hdr(struct ip6_hdr *ip6, struct ip *ip)
 528 {
 529         bzero(ip6, sizeof *ip6);
 530
 531         ip6->ip6_vfc = IPV6_VERSION;
 532         ip6->ip6_plen = ip->ip_len;
 533         ip6->ip6_nxt = ip->ip_p;
 534         ip6->ip6_hlim = ip->ip_ttl;
 535         ip6->ip6_src.s6_addr32[2] = ip6->ip6_dst.s6_addr32[2] =
 536                 IPV6_ADDR_INT32_SMP;
 537         ip6->ip6_src.s6_addr32[3] = ip->ip_src.s_addr;
 538         ip6->ip6_dst.s6_addr32[3] = ip->ip_dst.s_addr;
 539 }
 540 #endif
 541
 542 /*
 543  * subroutine of udp_input(), mainly for source code readability.
 544  * caller must properly init udp_ip6 and udp_in6 beforehand.
 545  */
 546 static void
 547 udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n, int off)
 548 {
 549         struct sockaddr *append_sa;
 550         struct mbuf *opts = NULL;
 551
 552         if (last->inp_flags & INP_CONTROLOPTS ||
 553             last->inp_socket->so_options & SO_TIMESTAMP) {
 554 #ifdef INET6
 555                 if (last->inp_vflag & INP_IPV6) {
 556                         int savedflags;
 557
 558                         if (udp_ip6.uip6_init_done == 0) {
 559                                 ip_2_ip6_hdr(&udp_ip6.uip6_ip6, ip);
 560                                 udp_ip6.uip6_init_done = 1;
 561                         }
 562                         savedflags = last->inp_flags;
 563                         last->inp_flags &= ~INP_UNMAPPABLEOPTS;
 564                         ip6_savecontrol(last, &opts, &udp_ip6.uip6_ip6, n);
 565                         last->inp_flags = savedflags;
 566                 } else
 567 #endif
 568                 ip_savecontrol(last, &opts, ip, n);
 569         }
 570 #ifdef INET6
 571         if (last->inp_vflag & INP_IPV6) {
 572                 if (udp_in6.uin6_init_done == 0) {
 573                         in6_sin_2_v4mapsin6(&udp_in, &udp_in6.uin6_sin);
 574                         udp_in6.uin6_init_done = 1;
 575                 }
 576                 append_sa = (struct sockaddr *)&udp_in6.uin6_sin;
 577         } else
 578 #endif
 579                 append_sa = (struct sockaddr *)&udp_in;
 580         m_adj(n, off);
 581         if (ssb_appendaddr(&last->inp_socket->so_rcv, append_sa, n, opts) == 0) {
 582                 m_freem(n);
 583                 if (opts)
 584                         m_freem(opts);
 585                 udpstat.udps_fullsock++;
 586         } else
 587                 sorwakeup(last->inp_socket);
 588 }
 589
 590 /*
 591  * Notify a udp user of an asynchronous error;
 592  * just wake up so that he can collect error status.
 593  */
 594 void
 595 udp_notify(struct inpcb *inp, int error)
 596 {
 597         inp->inp_socket->so_error = error;
 598         sorwakeup(inp->inp_socket);
 599         sowwakeup(inp->inp_socket);
 600 }
 601
 602 void
 603 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 604 {
 605         struct ip *ip = vip;
 606         struct udphdr *uh;
 607         void (*notify) (struct inpcb *, int) = udp_notify;
 608         struct in_addr faddr;
 609         struct inpcb *inp;
 610
 611         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 612         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 613                 return;
 614
 615         if (PRC_IS_REDIRECT(cmd)) {
 616                 ip = NULL;
 617                 notify = in_rtchange;
 618         } else if (cmd == PRC_HOSTDEAD)
 619                 ip = NULL;
 620         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 621                 return;
 622         if (ip) {
 623                 crit_enter();
 624                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 625                 inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
 626                                         ip->ip_src, uh->uh_sport, 0, NULL);
 627                 if (inp != NULL && inp->inp_socket != NULL)
 628                         (*notify)(inp, inetctlerrmap[cmd]);
 629                 crit_exit();
 630         } else
 631                 in_pcbnotifyall(&udbinfo.pcblisthead, faddr, inetctlerrmap[cmd],
 632                                 notify);
 633 }
 634
 635 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, &udbinfo, 0,
 636             in_pcblist_global, "S,xinpcb", "List of active UDP sockets");
 637
 638 static int
 639 udp_getcred(SYSCTL_HANDLER_ARGS)
 640 {
 641         struct sockaddr_in addrs[2];
 642         struct inpcb *inp;
 643         int error;
 644
 645         error = suser(req->td);
 646         if (error)
 647                 return (error);
 648         error = SYSCTL_IN(req, addrs, sizeof addrs);
 649         if (error)
 650                 return (error);
 651         crit_enter();
 652         inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 653                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
 654         if (inp == NULL || inp->inp_socket == NULL) {
 655                 error = ENOENT;
 656                 goto out;
 657         }
 658         error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
 659 out:
 660         crit_exit();
 661         return (error);
 662 }
 663
 664 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
 665     0, 0, udp_getcred, "S,ucred", "Get the ucred of a UDP connection");
 666
 667 static int
 668 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *dstaddr,
 669            struct mbuf *control, struct thread *td)
 670 {
 671         struct udpiphdr *ui;
 672         int len = m->m_pkthdr.len;
 673         struct sockaddr_in *sin;        /* really is initialized before use */
 674         int error = 0;
 675
 676         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 677                 error = EMSGSIZE;
 678                 goto release;
 679         }
 680
 681         if (inp->inp_lport == 0) {      /* unbound socket */
 682                 error = in_pcbbind(inp, (struct sockaddr *)NULL, td);
 683                 if (error)
 684                         goto release;
 685                 in_pcbinswildcardhash(inp);
 686         }
 687
 688         if (dstaddr != NULL) {          /* destination address specified */
 689                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 690                         /* already connected */
 691                         error = EISCONN;
 692                         goto release;
 693                 }
 694                 sin = (struct sockaddr_in *)dstaddr;
 695                 if (!prison_remote_ip(td, (struct sockaddr *)&sin)) {
 696                         error = EAFNOSUPPORT; /* IPv6 only jail */
 697                         goto release;
 698                 }
 699         } else {
 700                 if (inp->inp_faddr.s_addr == INADDR_ANY) {
 701                         /* no destination specified and not already connected */
 702                         error = ENOTCONN;
 703                         goto release;
 704                 }
 705                 sin = NULL;
 706         }
 707
 708         /*
 709          * Calculate data length and get a mbuf
 710          * for UDP and IP headers.
 711          */
 712         M_PREPEND(m, sizeof(struct udpiphdr), MB_DONTWAIT);
 713         if (m == NULL) {
 714                 error = ENOBUFS;
 715                 goto release;
 716         }
 717
 718         /*
 719          * Fill in mbuf with extended UDP header
 720          * and addresses and length put into network format.
 721          */
 722         ui = mtod(m, struct udpiphdr *);
 723         bzero(ui->ui_x1, sizeof ui->ui_x1);     /* XXX still needed? */
 724         ui->ui_pr = IPPROTO_UDP;
 725
 726         /*
 727          * Set destination address.
 728          */
 729         if (dstaddr != NULL) {                  /* use specified destination */
 730                 ui->ui_dst = sin->sin_addr;
 731                 ui->ui_dport = sin->sin_port;
 732         } else {                                /* use connected destination */
 733                 ui->ui_dst = inp->inp_faddr;
 734                 ui->ui_dport = inp->inp_fport;
 735         }
 736
 737         /*
 738          * Set source address.
 739          */
 740         if (inp->inp_laddr.s_addr == INADDR_ANY) {
 741                 struct sockaddr_in *if_sin;
 742
 743                 if (dstaddr == NULL) {
 744                         /*
 745                          * connect() had (or should have) failed because
 746                          * the interface had no IP address, but the
 747                          * application proceeded to call send() anyways.
 748                          */
 749                         error = ENOTCONN;
 750                         goto release;
 751                 }
 752
 753                 /* Look up outgoing interface. */
 754                 if ((error = in_pcbladdr(inp, dstaddr, &if_sin, td)))
 755                         goto release;
 756                 ui->ui_src = if_sin->sin_addr;  /* use address of interface */
 757         } else {
 758                 ui->ui_src = inp->inp_laddr;    /* use non-null bound address */
 759         }
 760         ui->ui_sport = inp->inp_lport;
 761         KASSERT(inp->inp_lport != 0, ("inp lport should have been bound"));
 762
 763         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
 764
 765         /*
 766          * Set up checksum and output datagram.
 767          */
 768         if (udpcksum) {
 769                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, ui->ui_dst.s_addr,
 770                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
 771                 m->m_pkthdr.csum_flags = CSUM_UDP;
 772                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 773         } else {
 774                 ui->ui_sum = 0;
 775         }
 776         ((struct ip *)ui)->ip_len = sizeof(struct udpiphdr) + len;
 777         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
 778         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
 779         udpstat.udps_opackets++;
 780
 781         error = ip_output(m, inp->inp_options, &inp->inp_route,
 782             (inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST)),
 783             inp->inp_moptions, inp);
 784
 785         return (error);
 786
 787 release:
 788         m_freem(m);
 789         return (error);
 790 }
 791
 792 u_long  udp_sendspace = 9216;           /* really max datagram size */
 793                                         /* 40 1K datagrams */
 794 SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 795     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 796
 797 u_long  udp_recvspace = 40 * (1024 +
 798 #ifdef INET6
 799                                       sizeof(struct sockaddr_in6)
 800 #else
 801                                       sizeof(struct sockaddr_in)
 802 #endif
 803                                       );
 804 SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 805     &udp_recvspace, 0, "Maximum incoming UDP datagram size");
 806
 807 static int
 808 udp_abort(struct socket *so)
 809 {
 810         struct inpcb *inp;
 811
 812         inp = so->so_pcb;
 813         if (inp == NULL)
 814                 return EINVAL;  /* ??? possible? panic instead? */
 815         soisdisconnected(so);
 816         crit_enter();
 817         in_pcbdetach(inp);
 818         crit_exit();
 819         return 0;
 820 }
 821
 822 static int
 823 udp_attach(struct socket *so, int proto, struct pru_attach_info *ai)
 824 {
 825         struct inpcb *inp;
 826         int error;
 827
 828         inp = so->so_pcb;
 829         if (inp != NULL)
 830                 return EINVAL;
 831
 832         error = soreserve(so, udp_sendspace, udp_recvspace, ai->sb_rlimit);
 833         if (error)
 834                 return error;
 835         crit_enter();
 836         error = in_pcballoc(so, &udbinfo);
 837         crit_exit();
 838         if (error)
 839                 return error;
 840
 841         inp = (struct inpcb *)so->so_pcb;
 842         inp->inp_vflag |= INP_IPV4;
 843         inp->inp_ip_ttl = ip_defttl;
 844         return 0;
 845 }
 846
 847 static int
 848 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 849 {
 850         struct sockaddr_in *sin = (struct sockaddr_in *)nam;
 851         struct inpcb *inp;
 852         int error;
 853
 854         inp = so->so_pcb;
 855         if (inp == NULL)
 856                 return EINVAL;
 857         crit_enter();
 858         error = in_pcbbind(inp, nam, td);
 859         crit_exit();
 860         if (error == 0) {
 861                 if (sin->sin_addr.s_addr != INADDR_ANY)
 862                         inp->inp_flags |= INP_WASBOUND_NOTANY;
 863                 in_pcbinswildcardhash(inp);
 864         }
 865         return error;
 866 }
 867
 868 static int
 869 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 870 {
 871         struct inpcb *inp;
 872         int error;
 873
 874         inp = so->so_pcb;
 875         if (inp == NULL)
 876                 return EINVAL;
 877         if (inp->inp_faddr.s_addr != INADDR_ANY)
 878                 return EISCONN;
 879         error = 0;
 880         crit_enter();
 881         if (td->td_proc && td->td_proc->p_ucred->cr_prison != NULL &&
 882             inp->inp_laddr.s_addr == INADDR_ANY) {
 883                 error = in_pcbbind(inp, NULL, td);
 884         }
 885         if (error == 0) {
 886                 if (!prison_remote_ip(td, nam))
 887                         return(EAFNOSUPPORT); /* IPv6 only jail */
 888                 if (inp->inp_flags & INP_WILDCARD)
 889                         in_pcbremwildcardhash(inp);
 890                 error = in_pcbconnect(inp, nam, td);
 891         }
 892         crit_exit();
 893         if (error == 0)
 894                 soisconnected(so);
 895         else if (error == EAFNOSUPPORT) {       /* connection dissolved */
 896                 /*
 897                  * Follow traditional BSD behavior and retain
 898                  * the local port binding.  But, fix the old misbehavior
 899                  * of overwriting any previously bound local address.
 900                  */
 901                 if (!(inp->inp_flags & INP_WASBOUND_NOTANY))
 902                         inp->inp_laddr.s_addr = INADDR_ANY;
 903                 in_pcbinswildcardhash(inp);
 904         }
 905         return error;
 906 }
 907
 908 static int
 909 udp_detach(struct socket *so)
 910 {
 911         struct inpcb *inp;
 912
 913         inp = so->so_pcb;
 914         if (inp == NULL)
 915                 return EINVAL;
 916         crit_enter();
 917         in_pcbdetach(inp);
 918         crit_exit();
 919         return 0;
 920 }
 921
 922 static int
 923 udp_disconnect(struct socket *so)
 924 {
 925         struct inpcb *inp;
 926
 927         inp = so->so_pcb;
 928         if (inp == NULL)
 929                 return EINVAL;
 930         if (inp->inp_faddr.s_addr == INADDR_ANY)
 931                 return ENOTCONN;
 932
 933         crit_enter();
 934         in_pcbdisconnect(inp);
 935         crit_exit();
 936         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
 937         return 0;
 938 }
 939
 940 static int
 941 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
 942             struct mbuf *control, struct thread *td)
 943 {
 944         struct inpcb *inp;
 945
 946         inp = so->so_pcb;
 947         if (inp == NULL) {
 948                 m_freem(m);
 949                 return EINVAL;
 950         }
 951         return udp_output(inp, m, addr, control, td);
 952 }
 953
 954 int
 955 udp_shutdown(struct socket *so)
 956 {
 957         struct inpcb *inp;
 958
 959         inp = so->so_pcb;
 960         if (inp == NULL)
 961                 return EINVAL;
 962         socantsendmore(so);
 963         return 0;
 964 }
 965
 966 struct pr_usrreqs udp_usrreqs = {
 967         .pru_abort = udp_abort,
 968         .pru_accept = pru_accept_notsupp,
 969         .pru_attach = udp_attach,
 970         .pru_bind = udp_bind,
 971         .pru_connect = udp_connect,
 972         .pru_connect2 = pru_connect2_notsupp,
 973         .pru_control = in_control,
 974         .pru_detach = udp_detach,
 975         .pru_disconnect = udp_disconnect,
 976         .pru_listen = pru_listen_notsupp,
 977         .pru_peeraddr = in_setpeeraddr,
 978         .pru_rcvd = pru_rcvd_notsupp,
 979         .pru_rcvoob = pru_rcvoob_notsupp,
 980         .pru_send = udp_send,
 981         .pru_sense = pru_sense_null,
 982         .pru_shutdown = udp_shutdown,
 983         .pru_sockaddr = in_setsockaddr,
 984         .pru_sosend = sosendudp,
 985         .pru_soreceive = soreceive,
 986         .pru_sopoll = sopoll
 987 };
 988