sys/netinet/udp_usrreq.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
   3  *      The Regents of the University of California.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 4. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include "opt_ipfw.h"
  37 #include "opt_inet6.h"
  38 #include "opt_ipsec.h"
  39 #include "opt_mac.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/domain.h>
  43 #include <sys/eventhandler.h>
  44 #include <sys/jail.h>
  45 #include <sys/kernel.h>
  46 #include <sys/lock.h>
  47 #include <sys/malloc.h>
  48 #include <sys/mbuf.h>
  49 #include <sys/priv.h>
  50 #include <sys/proc.h>
  51 #include <sys/protosw.h>
  52 #include <sys/signalvar.h>
  53 #include <sys/socket.h>
  54 #include <sys/socketvar.h>
  55 #include <sys/sx.h>
  56 #include <sys/sysctl.h>
  57 #include <sys/syslog.h>
  58 #include <sys/systm.h>
  59
  60 #include <vm/uma.h>
  61
  62 #include <net/if.h>
  63 #include <net/route.h>
  64
  65 #include <netinet/in.h>
  66 #include <netinet/in_pcb.h>
  67 #include <netinet/in_systm.h>
  68 #include <netinet/in_var.h>
  69 #include <netinet/ip.h>
  70 #ifdef INET6
  71 #include <netinet/ip6.h>
  72 #endif
  73 #include <netinet/ip_icmp.h>
  74 #include <netinet/icmp_var.h>
  75 #include <netinet/ip_var.h>
  76 #include <netinet/ip_options.h>
  77 #ifdef INET6
  78 #include <netinet6/ip6_var.h>
  79 #endif
  80 #include <netinet/udp.h>
  81 #include <netinet/udp_var.h>
  82
  83 #ifdef IPSEC
  84 #include <netipsec/ipsec.h>
  85 #endif
  86
  87 #include <machine/in_cksum.h>
  88
  89 #include <security/mac/mac_framework.h>
  90
  91 /*
  92  * UDP protocol implementation.
  93  * Per RFC 768, August, 1980.
  94  */
  95
  96 /*
  97  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
  98  * removes the only data integrity mechanism for packets and malformed
  99  * packets that would otherwise be discarded due to bad checksums, and may
 100  * cause problems (especially for NFS data blocks).
 101  */
 102 static int      udp_cksum = 1;
 103 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum,
 104     0, "");
 105
 106 int     udp_log_in_vain = 0;
 107 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 108     &udp_log_in_vain, 0, "Log all incoming UDP packets");
 109
 110 int     udp_blackhole = 0;
 111 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW, &udp_blackhole, 0,
 112     "Do not send port unreachables for refused connects");
 113
 114 u_long  udp_sendspace = 9216;           /* really max datagram size */
 115                                         /* 40 1K datagrams */
 116 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 117     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 118
 119 u_long  udp_recvspace = 40 * (1024 +
 120 #ifdef INET6
 121                                       sizeof(struct sockaddr_in6)
 122 #else
 123                                       sizeof(struct sockaddr_in)
 124 #endif
 125                                       );
 126
 127 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 128     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 129
 130 struct inpcbhead        udb;            /* from udp_var.h */
 131 struct inpcbinfo        udbinfo;
 132
 133 #ifndef UDBHASHSIZE
 134 #define UDBHASHSIZE     16
 135 #endif
 136
 137 struct udpstat  udpstat;        /* from udp_var.h */
 138 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW, &udpstat,
 139     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 140
 141 static void     udp_detach(struct socket *so);
 142 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 143                     struct mbuf *, struct thread *);
 144
 145 static void
 146 udp_zone_change(void *tag)
 147 {
 148
 149         uma_zone_set_max(udbinfo.ipi_zone, maxsockets);
 150 }
 151
 152 static int
 153 udp_inpcb_init(void *mem, int size, int flags)
 154 {
 155         struct inpcb *inp;
 156
 157         inp = mem;
 158         INP_LOCK_INIT(inp, "inp", "udpinp");
 159         return (0);
 160 }
 161
 162 void
 163 udp_init(void)
 164 {
 165
 166         INP_INFO_LOCK_INIT(&udbinfo, "udp");
 167         LIST_INIT(&udb);
 168         udbinfo.ipi_listhead = &udb;
 169         udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
 170             &udbinfo.ipi_hashmask);
 171         udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
 172             &udbinfo.ipi_porthashmask);
 173         udbinfo.ipi_zone = uma_zcreate("udpcb", sizeof(struct inpcb), NULL,
 174             NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 175         uma_zone_set_max(udbinfo.ipi_zone, maxsockets);
 176         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 177             EVENTHANDLER_PRI_ANY);
 178 }
 179
 180 /*
 181  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 182  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 183  * contains the source address.  If the socket ends up being an IPv6 socket,
 184  * udp_append() will convert to a sockaddr_in6 before passing the address
 185  * into the socket code.
 186  */
 187 static void
 188 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 189     struct sockaddr_in *udp_in)
 190 {
 191         struct sockaddr *append_sa;
 192         struct socket *so;
 193         struct mbuf *opts = 0;
 194 #ifdef INET6
 195         struct sockaddr_in6 udp_in6;
 196 #endif
 197
 198         INP_LOCK_ASSERT(inp);
 199
 200 #ifdef IPSEC
 201         /* Check AH/ESP integrity. */
 202         if (ipsec4_in_reject(n, inp)) {
 203                 m_freem(n);
 204                 ipsec4stat.in_polvio++;
 205                 return;
 206         }
 207 #endif /* IPSEC */
 208 #ifdef MAC
 209         if (mac_inpcb_check_deliver(inp, n) != 0) {
 210                 m_freem(n);
 211                 return;
 212         }
 213 #endif
 214         if (inp->inp_flags & INP_CONTROLOPTS ||
 215             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 216 #ifdef INET6
 217                 if (inp->inp_vflag & INP_IPV6) {
 218                         int savedflags;
 219
 220                         savedflags = inp->inp_flags;
 221                         inp->inp_flags &= ~INP_UNMAPPABLEOPTS;
 222                         ip6_savecontrol(inp, n, &opts);
 223                         inp->inp_flags = savedflags;
 224                 } else
 225 #endif
 226                         ip_savecontrol(inp, &opts, ip, n);
 227         }
 228 #ifdef INET6
 229         if (inp->inp_vflag & INP_IPV6) {
 230                 bzero(&udp_in6, sizeof(udp_in6));
 231                 udp_in6.sin6_len = sizeof(udp_in6);
 232                 udp_in6.sin6_family = AF_INET6;
 233                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 234                 append_sa = (struct sockaddr *)&udp_in6;
 235         } else
 236 #endif
 237                 append_sa = (struct sockaddr *)udp_in;
 238         m_adj(n, off);
 239
 240         so = inp->inp_socket;
 241         SOCKBUF_LOCK(&so->so_rcv);
 242         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 243                 SOCKBUF_UNLOCK(&so->so_rcv);
 244                 m_freem(n);
 245                 if (opts)
 246                         m_freem(opts);
 247                 udpstat.udps_fullsock++;
 248         } else
 249                 sorwakeup_locked(so);
 250 }
 251
 252 void
 253 udp_input(struct mbuf *m, int off)
 254 {
 255         int iphlen = off;
 256         struct ip *ip;
 257         struct udphdr *uh;
 258         struct ifnet *ifp;
 259         struct inpcb *inp;
 260         int len;
 261         struct ip save_ip;
 262         struct sockaddr_in udp_in;
 263 #ifdef IPFIREWALL_FORWARD
 264         struct m_tag *fwd_tag;
 265 #endif
 266
 267         ifp = m->m_pkthdr.rcvif;
 268         udpstat.udps_ipackets++;
 269
 270         /*
 271          * Strip IP options, if any; should skip this, make available to
 272          * user, and use on returned packets, but we don't yet have a way to
 273          * check the checksum with options still present.
 274          */
 275         if (iphlen > sizeof (struct ip)) {
 276                 ip_stripoptions(m, (struct mbuf *)0);
 277                 iphlen = sizeof(struct ip);
 278         }
 279
 280         /*
 281          * Get IP and UDP header together in first mbuf.
 282          */
 283         ip = mtod(m, struct ip *);
 284         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 285                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 286                         udpstat.udps_hdrops++;
 287                         return;
 288                 }
 289                 ip = mtod(m, struct ip *);
 290         }
 291         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 292
 293         /*
 294          * Destination port of 0 is illegal, based on RFC768.
 295          */
 296         if (uh->uh_dport == 0)
 297                 goto badunlocked;
 298
 299         /*
 300          * Construct sockaddr format source address.  Stuff source address
 301          * and datagram in user buffer.
 302          */
 303         bzero(&udp_in, sizeof(udp_in));
 304         udp_in.sin_len = sizeof(udp_in);
 305         udp_in.sin_family = AF_INET;
 306         udp_in.sin_port = uh->uh_sport;
 307         udp_in.sin_addr = ip->ip_src;
 308
 309         /*
 310          * Make mbuf data length reflect UDP length.  If not enough data to
 311          * reflect UDP length, drop.
 312          */
 313         len = ntohs((u_short)uh->uh_ulen);
 314         if (ip->ip_len != len) {
 315                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 316                         udpstat.udps_badlen++;
 317                         goto badunlocked;
 318                 }
 319                 m_adj(m, len - ip->ip_len);
 320                 /* ip->ip_len = len; */
 321         }
 322
 323         /*
 324          * Save a copy of the IP header in case we want restore it for
 325          * sending an ICMP error message in response.
 326          */
 327         if (!udp_blackhole)
 328                 save_ip = *ip;
 329         else
 330                 memset(&save_ip, 0, sizeof(save_ip));
 331
 332         /*
 333          * Checksum extended UDP header and data.
 334          */
 335         if (uh->uh_sum) {
 336                 u_short uh_sum;
 337
 338                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 339                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 340                                 uh_sum = m->m_pkthdr.csum_data;
 341                         else
 342                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 343                                     ip->ip_dst.s_addr, htonl((u_short)len +
 344                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 345                         uh_sum ^= 0xffff;
 346                 } else {
 347                         char b[9];
 348
 349                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 350                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 351                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 352                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 353                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 354                 }
 355                 if (uh_sum) {
 356                         udpstat.udps_badsum++;
 357                         m_freem(m);
 358                         return;
 359                 }
 360         } else
 361                 udpstat.udps_nosum++;
 362
 363 #ifdef IPFIREWALL_FORWARD
 364         /*
 365          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 366          */
 367         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 368         if (fwd_tag != NULL) {
 369                 struct sockaddr_in *next_hop;
 370
 371                 /*
 372                  * Do the hack.
 373                  */
 374                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 375                 ip->ip_dst = next_hop->sin_addr;
 376                 uh->uh_dport = ntohs(next_hop->sin_port);
 377
 378                 /*
 379                  * Remove the tag from the packet.  We don't need it anymore.
 380                  */
 381                 m_tag_delete(m, fwd_tag);
 382         }
 383 #endif
 384
 385         INP_INFO_RLOCK(&udbinfo);
 386         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 387             in_broadcast(ip->ip_dst, ifp)) {
 388                 struct inpcb *last;
 389                 struct ip_moptions *imo;
 390
 391                 last = NULL;
 392                 LIST_FOREACH(inp, &udb, inp_list) {
 393                         if (inp->inp_lport != uh->uh_dport)
 394                                 continue;
 395 #ifdef INET6
 396                         if ((inp->inp_vflag & INP_IPV4) == 0)
 397                                 continue;
 398 #endif
 399                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 400                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 401                                 continue;
 402                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 403                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 404                                 continue;
 405                         /*
 406                          * XXX: Do not check source port of incoming datagram
 407                          * unless inp_connect() has been called to bind the
 408                          * fport part of the 4-tuple; the source could be
 409                          * trying to talk to us with an ephemeral port.
 410                          */
 411                         if (inp->inp_fport != 0 &&
 412                             inp->inp_fport != uh->uh_sport)
 413                                 continue;
 414
 415                         INP_LOCK(inp);
 416
 417                         /*
 418                          * Handle socket delivery policy for any-source
 419                          * and source-specific multicast. [RFC3678]
 420                          */
 421                         imo = inp->inp_moptions;
 422                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
 423                             imo != NULL) {
 424                                 struct sockaddr_in       sin;
 425                                 struct in_msource       *ims;
 426                                 int                      blocked, mode;
 427                                 size_t                   idx;
 428
 429                                 bzero(&sin, sizeof(struct sockaddr_in));
 430                                 sin.sin_len = sizeof(struct sockaddr_in);
 431                                 sin.sin_family = AF_INET;
 432                                 sin.sin_addr = ip->ip_dst;
 433
 434                                 blocked = 0;
 435                                 idx = imo_match_group(imo, ifp,
 436                                     (struct sockaddr *)&sin);
 437                                 if (idx == -1) {
 438                                         /*
 439                                          * No group membership for this socket.
 440                                          * Do not bump udps_noportbcast, as
 441                                          * this will happen further down.
 442                                          */
 443                                         blocked++;
 444                                 } else {
 445                                         /*
 446                                          * Check for a multicast source filter
 447                                          * entry on this socket for this group.
 448                                          * MCAST_EXCLUDE is the default
 449                                          * behaviour.  It means default accept;
 450                                          * entries, if present, denote sources
 451                                          * to be excluded from delivery.
 452                                          */
 453                                         ims = imo_match_source(imo, idx,
 454                                             (struct sockaddr *)&udp_in);
 455                                         mode = imo->imo_mfilters[idx].imf_fmode;
 456                                         if ((ims != NULL &&
 457                                              mode == MCAST_EXCLUDE) ||
 458                                             (ims == NULL &&
 459                                              mode == MCAST_INCLUDE)) {
 460 #ifdef DIAGNOSTIC
 461                                                 if (bootverbose) {
 462                                                         printf("%s: blocked by"
 463                                                             " source filter\n",
 464                                                             __func__);
 465                                                 }
 466 #endif
 467                                                 udpstat.udps_filtermcast++;
 468                                                 blocked++;
 469                                         }
 470                                 }
 471                                 if (blocked != 0) {
 472                                         INP_UNLOCK(inp);
 473                                         continue;
 474                                 }
 475                         }
 476                         if (last != NULL) {
 477                                 struct mbuf *n;
 478
 479                                 n = m_copy(m, 0, M_COPYALL);
 480                                 if (n != NULL)
 481                                         udp_append(last, ip, n, iphlen +
 482                                             sizeof(struct udphdr), &udp_in);
 483                                 INP_UNLOCK(last);
 484                         }
 485                         last = inp;
 486                         /*
 487                          * Don't look for additional matches if this one does
 488                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 489                          * socket options set.  This heuristic avoids
 490                          * searching through all pcbs in the common case of a
 491                          * non-shared port.  It assumes that an application
 492                          * will never clear these options after setting them.
 493                          */
 494                         if ((last->inp_socket->so_options &
 495                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 496                                 break;
 497                 }
 498
 499                 if (last == NULL) {
 500                         /*
 501                          * No matching pcb found; discard datagram.  (No need
 502                          * to send an ICMP Port Unreachable for a broadcast
 503                          * or multicast datgram.)
 504                          */
 505                         udpstat.udps_noportbcast++;
 506                         goto badheadlocked;
 507                 }
 508                 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
 509                     &udp_in);
 510                 INP_UNLOCK(last);
 511                 INP_INFO_RUNLOCK(&udbinfo);
 512                 return;
 513         }
 514
 515         /*
 516          * Locate pcb for datagram.
 517          */
 518         inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
 519             ip->ip_dst, uh->uh_dport, 1, ifp);
 520         if (inp == NULL) {
 521                 if (udp_log_in_vain) {
 522                         char buf[4*sizeof "123"];
 523
 524                         strcpy(buf, inet_ntoa(ip->ip_dst));
 525                         log(LOG_INFO,
 526                             "Connection attempt to UDP %s:%d from %s:%d\n",
 527                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 528                             ntohs(uh->uh_sport));
 529                 }
 530                 udpstat.udps_noport++;
 531                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 532                         udpstat.udps_noportbcast++;
 533                         goto badheadlocked;
 534                 }
 535                 if (udp_blackhole)
 536                         goto badheadlocked;
 537                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 538                         goto badheadlocked;
 539                 *ip = save_ip;
 540                 ip->ip_len += iphlen;
 541                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 542                 INP_INFO_RUNLOCK(&udbinfo);
 543                 return;
 544         }
 545
 546         /*
 547          * Check the minimum TTL for socket.
 548          */
 549         INP_LOCK(inp);
 550         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl)
 551                 goto badheadlocked;
 552         udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
 553         INP_UNLOCK(inp);
 554         INP_INFO_RUNLOCK(&udbinfo);
 555         return;
 556
 557 badheadlocked:
 558         if (inp)
 559                 INP_UNLOCK(inp);
 560         INP_INFO_RUNLOCK(&udbinfo);
 561 badunlocked:
 562         m_freem(m);
 563 }
 564
 565 /*
 566  * Notify a udp user of an asynchronous error; just wake up so that they can
 567  * collect error status.
 568  */
 569 struct inpcb *
 570 udp_notify(struct inpcb *inp, int errno)
 571 {
 572
 573         inp->inp_socket->so_error = errno;
 574         sorwakeup(inp->inp_socket);
 575         sowwakeup(inp->inp_socket);
 576         return (inp);
 577 }
 578
 579 void
 580 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 581 {
 582         struct ip *ip = vip;
 583         struct udphdr *uh;
 584         struct in_addr faddr;
 585         struct inpcb *inp;
 586
 587         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 588         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 589                 return;
 590
 591         /*
 592          * Redirects don't need to be handled up here.
 593          */
 594         if (PRC_IS_REDIRECT(cmd))
 595                 return;
 596
 597         /*
 598          * Hostdead is ugly because it goes linearly through all PCBs.
 599          *
 600          * XXX: We never get this from ICMP, otherwise it makes an excellent
 601          * DoS attack on machines with many connections.
 602          */
 603         if (cmd == PRC_HOSTDEAD)
 604                 ip = NULL;
 605         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 606                 return;
 607         if (ip != NULL) {
 608                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 609                 INP_INFO_RLOCK(&udbinfo);
 610                 inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
 611                     ip->ip_src, uh->uh_sport, 0, NULL);
 612                 if (inp != NULL) {
 613                         INP_LOCK(inp);
 614                         if (inp->inp_socket != NULL) {
 615                                 udp_notify(inp, inetctlerrmap[cmd]);
 616                         }
 617                         INP_UNLOCK(inp);
 618                 }
 619                 INP_INFO_RUNLOCK(&udbinfo);
 620         } else
 621                 in_pcbnotifyall(&udbinfo, faddr, inetctlerrmap[cmd],
 622                     udp_notify);
 623 }
 624
 625 static int
 626 udp_pcblist(SYSCTL_HANDLER_ARGS)
 627 {
 628         int error, i, n;
 629         struct inpcb *inp, **inp_list;
 630         inp_gen_t gencnt;
 631         struct xinpgen xig;
 632
 633         /*
 634          * The process of preparing the PCB list is too time-consuming and
 635          * resource-intensive to repeat twice on every request.
 636          */
 637         if (req->oldptr == 0) {
 638                 n = udbinfo.ipi_count;
 639                 req->oldidx = 2 * (sizeof xig)
 640                         + (n + n/8) * sizeof(struct xinpcb);
 641                 return (0);
 642         }
 643
 644         if (req->newptr != 0)
 645                 return (EPERM);
 646
 647         /*
 648          * OK, now we're committed to doing something.
 649          */
 650         INP_INFO_RLOCK(&udbinfo);
 651         gencnt = udbinfo.ipi_gencnt;
 652         n = udbinfo.ipi_count;
 653         INP_INFO_RUNLOCK(&udbinfo);
 654
 655         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 656                 + n * sizeof(struct xinpcb));
 657         if (error != 0)
 658                 return (error);
 659
 660         xig.xig_len = sizeof xig;
 661         xig.xig_count = n;
 662         xig.xig_gen = gencnt;
 663         xig.xig_sogen = so_gencnt;
 664         error = SYSCTL_OUT(req, &xig, sizeof xig);
 665         if (error)
 666                 return (error);
 667
 668         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 669         if (inp_list == 0)
 670                 return (ENOMEM);
 671
 672         INP_INFO_RLOCK(&udbinfo);
 673         for (inp = LIST_FIRST(udbinfo.ipi_listhead), i = 0; inp && i < n;
 674              inp = LIST_NEXT(inp, inp_list)) {
 675                 INP_LOCK(inp);
 676                 if (inp->inp_gencnt <= gencnt &&
 677                     cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
 678                         inp_list[i++] = inp;
 679                 INP_UNLOCK(inp);
 680         }
 681         INP_INFO_RUNLOCK(&udbinfo);
 682         n = i;
 683
 684         error = 0;
 685         for (i = 0; i < n; i++) {
 686                 inp = inp_list[i];
 687                 INP_LOCK(inp);
 688                 if (inp->inp_gencnt <= gencnt) {
 689                         struct xinpcb xi;
 690                         bzero(&xi, sizeof(xi));
 691                         xi.xi_len = sizeof xi;
 692                         /* XXX should avoid extra copy */
 693                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 694                         if (inp->inp_socket)
 695                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 696                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 697                         INP_UNLOCK(inp);
 698                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 699                 } else
 700                         INP_UNLOCK(inp);
 701         }
 702         if (!error) {
 703                 /*
 704                  * Give the user an updated idea of our state.  If the
 705                  * generation differs from what we told her before, she knows
 706                  * that something happened while we were processing this
 707                  * request, and it might be necessary to retry.
 708                  */
 709                 INP_INFO_RLOCK(&udbinfo);
 710                 xig.xig_gen = udbinfo.ipi_gencnt;
 711                 xig.xig_sogen = so_gencnt;
 712                 xig.xig_count = udbinfo.ipi_count;
 713                 INP_INFO_RUNLOCK(&udbinfo);
 714                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 715         }
 716         free(inp_list, M_TEMP);
 717         return (error);
 718 }
 719
 720 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
 721     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 722
 723 static int
 724 udp_getcred(SYSCTL_HANDLER_ARGS)
 725 {
 726         struct xucred xuc;
 727         struct sockaddr_in addrs[2];
 728         struct inpcb *inp;
 729         int error;
 730
 731         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 732         if (error)
 733                 return (error);
 734         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 735         if (error)
 736                 return (error);
 737         INP_INFO_RLOCK(&udbinfo);
 738         inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 739                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
 740         if (inp == NULL || inp->inp_socket == NULL) {
 741                 error = ENOENT;
 742                 goto out;
 743         }
 744         error = cr_canseesocket(req->td->td_ucred, inp->inp_socket);
 745         if (error)
 746                 goto out;
 747         cru2x(inp->inp_socket->so_cred, &xuc);
 748 out:
 749         INP_INFO_RUNLOCK(&udbinfo);
 750         if (error == 0)
 751                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 752         return (error);
 753 }
 754
 755 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 756     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 757     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 758
 759 static int
 760 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
 761     struct mbuf *control, struct thread *td)
 762 {
 763         struct udpiphdr *ui;
 764         int len = m->m_pkthdr.len;
 765         struct in_addr faddr, laddr;
 766         struct cmsghdr *cm;
 767         struct sockaddr_in *sin, src;
 768         int error = 0;
 769         int ipflags;
 770         u_short fport, lport;
 771         int unlock_udbinfo;
 772
 773         /*
 774          * udp_output() may need to temporarily bind or connect the current
 775          * inpcb.  As such, we don't know up front whether we will need the
 776          * pcbinfo lock or not.  Do any work to decide what is needed up
 777          * front before acquiring any locks.
 778          */
 779         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 780                 if (control)
 781                         m_freem(control);
 782                 m_freem(m);
 783                 return (EMSGSIZE);
 784         }
 785
 786         src.sin_family = 0;
 787         if (control != NULL) {
 788                 /*
 789                  * XXX: Currently, we assume all the optional information is
 790                  * stored in a single mbuf.
 791                  */
 792                 if (control->m_next) {
 793                         m_freem(control);
 794                         m_freem(m);
 795                         return (EINVAL);
 796                 }
 797                 for (; control->m_len > 0;
 798                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 799                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 800                         cm = mtod(control, struct cmsghdr *);
 801                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 802                             || cm->cmsg_len > control->m_len) {
 803                                 error = EINVAL;
 804                                 break;
 805                         }
 806                         if (cm->cmsg_level != IPPROTO_IP)
 807                                 continue;
 808
 809                         switch (cm->cmsg_type) {
 810                         case IP_SENDSRCADDR:
 811                                 if (cm->cmsg_len !=
 812                                     CMSG_LEN(sizeof(struct in_addr))) {
 813                                         error = EINVAL;
 814                                         break;
 815                                 }
 816                                 bzero(&src, sizeof(src));
 817                                 src.sin_family = AF_INET;
 818                                 src.sin_len = sizeof(src);
 819                                 src.sin_port = inp->inp_lport;
 820                                 src.sin_addr =
 821                                     *(struct in_addr *)CMSG_DATA(cm);
 822                                 break;
 823
 824                         default:
 825                                 error = ENOPROTOOPT;
 826                                 break;
 827                         }
 828                         if (error)
 829                                 break;
 830                 }
 831                 m_freem(control);
 832         }
 833         if (error) {
 834                 m_freem(m);
 835                 return (error);
 836         }
 837
 838         if (src.sin_family == AF_INET || addr != NULL) {
 839                 INP_INFO_WLOCK(&udbinfo);
 840                 unlock_udbinfo = 1;
 841         } else
 842                 unlock_udbinfo = 0;
 843         INP_LOCK(inp);
 844
 845 #ifdef MAC
 846         mac_inpcb_create_mbuf(inp, m);
 847 #endif
 848
 849         /*
 850          * If the IP_SENDSRCADDR control message was specified, override the
 851          * source address for this datagram.  Its use is invalidated if the
 852          * address thus specified is incomplete or clobbers other inpcbs.
 853          */
 854         laddr = inp->inp_laddr;
 855         lport = inp->inp_lport;
 856         if (src.sin_family == AF_INET) {
 857                 if ((lport == 0) ||
 858                     (laddr.s_addr == INADDR_ANY &&
 859                      src.sin_addr.s_addr == INADDR_ANY)) {
 860                         error = EINVAL;
 861                         goto release;
 862                 }
 863                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
 864                     &laddr.s_addr, &lport, td->td_ucred);
 865                 if (error)
 866                         goto release;
 867         }
 868
 869         if (addr) {
 870                 sin = (struct sockaddr_in *)addr;
 871                 if (jailed(td->td_ucred))
 872                         prison_remote_ip(td->td_ucred, 0,
 873                             &sin->sin_addr.s_addr);
 874                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 875                         error = EISCONN;
 876                         goto release;
 877                 }
 878                 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr, &lport,
 879                     &faddr.s_addr, &fport, NULL, td->td_ucred);
 880                 if (error)
 881                         goto release;
 882
 883                 /* Commit the local port if newly assigned. */
 884                 if (inp->inp_laddr.s_addr == INADDR_ANY &&
 885                     inp->inp_lport == 0) {
 886                         /*
 887                          * Remember addr if jailed, to prevent rebinding.
 888                          */
 889                         if (jailed(td->td_ucred))
 890                                 inp->inp_laddr = laddr;
 891                         inp->inp_lport = lport;
 892                         if (in_pcbinshash(inp) != 0) {
 893                                 inp->inp_lport = 0;
 894                                 error = EAGAIN;
 895                                 goto release;
 896                         }
 897                         inp->inp_flags |= INP_ANONPORT;
 898                 }
 899         } else {
 900                 faddr = inp->inp_faddr;
 901                 fport = inp->inp_fport;
 902                 if (faddr.s_addr == INADDR_ANY) {
 903                         error = ENOTCONN;
 904                         goto release;
 905                 }
 906         }
 907
 908         /*
 909          * Calculate data length and get a mbuf for UDP, IP, and possible
 910          * link-layer headers.  Immediate slide the data pointer back forward
 911          * since we won't use that space at this layer.
 912          */
 913         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
 914         if (m == NULL) {
 915                 error = ENOBUFS;
 916                 goto release;
 917         }
 918         m->m_data += max_linkhdr;
 919         m->m_len -= max_linkhdr;
 920         m->m_pkthdr.len -= max_linkhdr;
 921
 922         /*
 923          * Fill in mbuf with extended UDP header and addresses and length put
 924          * into network format.
 925          */
 926         ui = mtod(m, struct udpiphdr *);
 927         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
 928         ui->ui_pr = IPPROTO_UDP;
 929         ui->ui_src = laddr;
 930         ui->ui_dst = faddr;
 931         ui->ui_sport = lport;
 932         ui->ui_dport = fport;
 933         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
 934
 935         /*
 936          * Set the Don't Fragment bit in the IP header.
 937          */
 938         if (inp->inp_flags & INP_DONTFRAG) {
 939                 struct ip *ip;
 940
 941                 ip = (struct ip *)&ui->ui_i;
 942                 ip->ip_off |= IP_DF;
 943         }
 944
 945         ipflags = 0;
 946         if (inp->inp_socket->so_options & SO_DONTROUTE)
 947                 ipflags |= IP_ROUTETOIF;
 948         if (inp->inp_socket->so_options & SO_BROADCAST)
 949                 ipflags |= IP_ALLOWBROADCAST;
 950         if (inp->inp_flags & INP_ONESBCAST)
 951                 ipflags |= IP_SENDONES;
 952
 953         /*
 954          * Set up checksum and output datagram.
 955          */
 956         if (udp_cksum) {
 957                 if (inp->inp_flags & INP_ONESBCAST)
 958                         faddr.s_addr = INADDR_BROADCAST;
 959                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
 960                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
 961                 m->m_pkthdr.csum_flags = CSUM_UDP;
 962                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 963         } else
 964                 ui->ui_sum = 0;
 965         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
 966         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
 967         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
 968         udpstat.udps_opackets++;
 969
 970         if (unlock_udbinfo)
 971                 INP_INFO_WUNLOCK(&udbinfo);
 972         error = ip_output(m, inp->inp_options, NULL, ipflags,
 973             inp->inp_moptions, inp);
 974         INP_UNLOCK(inp);
 975         return (error);
 976
 977 release:
 978         INP_UNLOCK(inp);
 979         if (unlock_udbinfo)
 980                 INP_INFO_WUNLOCK(&udbinfo);
 981         m_freem(m);
 982         return (error);
 983 }
 984
 985 static void
 986 udp_abort(struct socket *so)
 987 {
 988         struct inpcb *inp;
 989
 990         inp = sotoinpcb(so);
 991         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
 992         INP_INFO_WLOCK(&udbinfo);
 993         INP_LOCK(inp);
 994         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 995                 in_pcbdisconnect(inp);
 996                 inp->inp_laddr.s_addr = INADDR_ANY;
 997                 soisdisconnected(so);
 998         }
 999         INP_UNLOCK(inp);
1000         INP_INFO_WUNLOCK(&udbinfo);
1001 }
1002
1003 static int
1004 udp_attach(struct socket *so, int proto, struct thread *td)
1005 {
1006         struct inpcb *inp;
1007         int error;
1008
1009         inp = sotoinpcb(so);
1010         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1011         error = soreserve(so, udp_sendspace, udp_recvspace);
1012         if (error)
1013                 return (error);
1014         INP_INFO_WLOCK(&udbinfo);
1015         error = in_pcballoc(so, &udbinfo);
1016         if (error) {
1017                 INP_INFO_WUNLOCK(&udbinfo);
1018                 return (error);
1019         }
1020
1021         inp = (struct inpcb *)so->so_pcb;
1022         INP_INFO_WUNLOCK(&udbinfo);
1023         inp->inp_vflag |= INP_IPV4;
1024         inp->inp_ip_ttl = ip_defttl;
1025         INP_UNLOCK(inp);
1026         return (0);
1027 }
1028
1029 static int
1030 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1031 {
1032         struct inpcb *inp;
1033         int error;
1034
1035         inp = sotoinpcb(so);
1036         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1037         INP_INFO_WLOCK(&udbinfo);
1038         INP_LOCK(inp);
1039         error = in_pcbbind(inp, nam, td->td_ucred);
1040         INP_UNLOCK(inp);
1041         INP_INFO_WUNLOCK(&udbinfo);
1042         return (error);
1043 }
1044
1045 static void
1046 udp_close(struct socket *so)
1047 {
1048         struct inpcb *inp;
1049
1050         inp = sotoinpcb(so);
1051         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1052         INP_INFO_WLOCK(&udbinfo);
1053         INP_LOCK(inp);
1054         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1055                 in_pcbdisconnect(inp);
1056                 inp->inp_laddr.s_addr = INADDR_ANY;
1057                 soisdisconnected(so);
1058         }
1059         INP_UNLOCK(inp);
1060         INP_INFO_WUNLOCK(&udbinfo);
1061 }
1062
1063 static int
1064 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1065 {
1066         struct inpcb *inp;
1067         int error;
1068         struct sockaddr_in *sin;
1069
1070         inp = sotoinpcb(so);
1071         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1072         INP_INFO_WLOCK(&udbinfo);
1073         INP_LOCK(inp);
1074         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1075                 INP_UNLOCK(inp);
1076                 INP_INFO_WUNLOCK(&udbinfo);
1077                 return (EISCONN);
1078         }
1079         sin = (struct sockaddr_in *)nam;
1080         if (jailed(td->td_ucred))
1081                 prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr);
1082         error = in_pcbconnect(inp, nam, td->td_ucred);
1083         if (error == 0)
1084                 soisconnected(so);
1085         INP_UNLOCK(inp);
1086         INP_INFO_WUNLOCK(&udbinfo);
1087         return (error);
1088 }
1089
1090 static void
1091 udp_detach(struct socket *so)
1092 {
1093         struct inpcb *inp;
1094
1095         inp = sotoinpcb(so);
1096         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1097         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1098             ("udp_detach: not disconnected"));
1099         INP_INFO_WLOCK(&udbinfo);
1100         INP_LOCK(inp);
1101         in_pcbdetach(inp);
1102         in_pcbfree(inp);
1103         INP_INFO_WUNLOCK(&udbinfo);
1104 }
1105
1106 static int
1107 udp_disconnect(struct socket *so)
1108 {
1109         struct inpcb *inp;
1110
1111         inp = sotoinpcb(so);
1112         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1113         INP_INFO_WLOCK(&udbinfo);
1114         INP_LOCK(inp);
1115         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1116                 INP_INFO_WUNLOCK(&udbinfo);
1117                 INP_UNLOCK(inp);
1118                 return (ENOTCONN);
1119         }
1120
1121         in_pcbdisconnect(inp);
1122         inp->inp_laddr.s_addr = INADDR_ANY;
1123         SOCK_LOCK(so);
1124         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1125         SOCK_UNLOCK(so);
1126         INP_UNLOCK(inp);
1127         INP_INFO_WUNLOCK(&udbinfo);
1128         return (0);
1129 }
1130
1131 static int
1132 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1133     struct mbuf *control, struct thread *td)
1134 {
1135         struct inpcb *inp;
1136
1137         inp = sotoinpcb(so);
1138         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1139         return (udp_output(inp, m, addr, control, td));
1140 }
1141
1142 int
1143 udp_shutdown(struct socket *so)
1144 {
1145         struct inpcb *inp;
1146
1147         inp = sotoinpcb(so);
1148         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1149         INP_LOCK(inp);
1150         socantsendmore(so);
1151         INP_UNLOCK(inp);
1152         return (0);
1153 }
1154
1155 struct pr_usrreqs udp_usrreqs = {
1156         .pru_abort =            udp_abort,
1157         .pru_attach =           udp_attach,
1158         .pru_bind =             udp_bind,
1159         .pru_connect =          udp_connect,
1160         .pru_control =          in_control,
1161         .pru_detach =           udp_detach,
1162         .pru_disconnect =       udp_disconnect,
1163         .pru_peeraddr =         in_getpeeraddr,
1164         .pru_send =             udp_send,
1165         .pru_sosend =           sosend_dgram,
1166         .pru_shutdown =         udp_shutdown,
1167         .pru_sockaddr =         in_getsockaddr,
1168         .pru_sosetlabel =       in_pcbsosetlabel,
1169         .pru_close =            udp_close,
1170 };