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_RLOCK_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                         ip6_savecontrol_v4(inp, n, &opts);
 219                 else
 220 #endif
 221                         ip_savecontrol(inp, &opts, ip, n);
 222         }
 223 #ifdef INET6
 224         if (inp->inp_vflag & INP_IPV6) {
 225                 bzero(&udp_in6, sizeof(udp_in6));
 226                 udp_in6.sin6_len = sizeof(udp_in6);
 227                 udp_in6.sin6_family = AF_INET6;
 228                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 229                 append_sa = (struct sockaddr *)&udp_in6;
 230         } else
 231 #endif
 232                 append_sa = (struct sockaddr *)udp_in;
 233         m_adj(n, off);
 234
 235         so = inp->inp_socket;
 236         SOCKBUF_LOCK(&so->so_rcv);
 237         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 238                 SOCKBUF_UNLOCK(&so->so_rcv);
 239                 m_freem(n);
 240                 if (opts)
 241                         m_freem(opts);
 242                 udpstat.udps_fullsock++;
 243         } else
 244                 sorwakeup_locked(so);
 245 }
 246
 247 void
 248 udp_input(struct mbuf *m, int off)
 249 {
 250         int iphlen = off;
 251         struct ip *ip;
 252         struct udphdr *uh;
 253         struct ifnet *ifp;
 254         struct inpcb *inp;
 255         int len;
 256         struct ip save_ip;
 257         struct sockaddr_in udp_in;
 258 #ifdef IPFIREWALL_FORWARD
 259         struct m_tag *fwd_tag;
 260 #endif
 261
 262         ifp = m->m_pkthdr.rcvif;
 263         udpstat.udps_ipackets++;
 264
 265         /*
 266          * Strip IP options, if any; should skip this, make available to
 267          * user, and use on returned packets, but we don't yet have a way to
 268          * check the checksum with options still present.
 269          */
 270         if (iphlen > sizeof (struct ip)) {
 271                 ip_stripoptions(m, (struct mbuf *)0);
 272                 iphlen = sizeof(struct ip);
 273         }
 274
 275         /*
 276          * Get IP and UDP header together in first mbuf.
 277          */
 278         ip = mtod(m, struct ip *);
 279         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 280                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 281                         udpstat.udps_hdrops++;
 282                         return;
 283                 }
 284                 ip = mtod(m, struct ip *);
 285         }
 286         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 287
 288         /*
 289          * Destination port of 0 is illegal, based on RFC768.
 290          */
 291         if (uh->uh_dport == 0)
 292                 goto badunlocked;
 293
 294         /*
 295          * Construct sockaddr format source address.  Stuff source address
 296          * and datagram in user buffer.
 297          */
 298         bzero(&udp_in, sizeof(udp_in));
 299         udp_in.sin_len = sizeof(udp_in);
 300         udp_in.sin_family = AF_INET;
 301         udp_in.sin_port = uh->uh_sport;
 302         udp_in.sin_addr = ip->ip_src;
 303
 304         /*
 305          * Make mbuf data length reflect UDP length.  If not enough data to
 306          * reflect UDP length, drop.
 307          */
 308         len = ntohs((u_short)uh->uh_ulen);
 309         if (ip->ip_len != len) {
 310                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 311                         udpstat.udps_badlen++;
 312                         goto badunlocked;
 313                 }
 314                 m_adj(m, len - ip->ip_len);
 315                 /* ip->ip_len = len; */
 316         }
 317
 318         /*
 319          * Save a copy of the IP header in case we want restore it for
 320          * sending an ICMP error message in response.
 321          */
 322         if (!udp_blackhole)
 323                 save_ip = *ip;
 324         else
 325                 memset(&save_ip, 0, sizeof(save_ip));
 326
 327         /*
 328          * Checksum extended UDP header and data.
 329          */
 330         if (uh->uh_sum) {
 331                 u_short uh_sum;
 332
 333                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 334                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 335                                 uh_sum = m->m_pkthdr.csum_data;
 336                         else
 337                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 338                                     ip->ip_dst.s_addr, htonl((u_short)len +
 339                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 340                         uh_sum ^= 0xffff;
 341                 } else {
 342                         char b[9];
 343
 344                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 345                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 346                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 347                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 348                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 349                 }
 350                 if (uh_sum) {
 351                         udpstat.udps_badsum++;
 352                         m_freem(m);
 353                         return;
 354                 }
 355         } else
 356                 udpstat.udps_nosum++;
 357
 358 #ifdef IPFIREWALL_FORWARD
 359         /*
 360          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 361          */
 362         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 363         if (fwd_tag != NULL) {
 364                 struct sockaddr_in *next_hop;
 365
 366                 /*
 367                  * Do the hack.
 368                  */
 369                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 370                 ip->ip_dst = next_hop->sin_addr;
 371                 uh->uh_dport = ntohs(next_hop->sin_port);
 372
 373                 /*
 374                  * Remove the tag from the packet.  We don't need it anymore.
 375                  */
 376                 m_tag_delete(m, fwd_tag);
 377         }
 378 #endif
 379
 380         INP_INFO_RLOCK(&udbinfo);
 381         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 382             in_broadcast(ip->ip_dst, ifp)) {
 383                 struct inpcb *last;
 384                 struct ip_moptions *imo;
 385
 386                 last = NULL;
 387                 LIST_FOREACH(inp, &udb, inp_list) {
 388                         if (inp->inp_lport != uh->uh_dport)
 389                                 continue;
 390 #ifdef INET6
 391                         if ((inp->inp_vflag & INP_IPV4) == 0)
 392                                 continue;
 393 #endif
 394                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 395                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 396                                 continue;
 397                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 398                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 399                                 continue;
 400                         /*
 401                          * XXX: Do not check source port of incoming datagram
 402                          * unless inp_connect() has been called to bind the
 403                          * fport part of the 4-tuple; the source could be
 404                          * trying to talk to us with an ephemeral port.
 405                          */
 406                         if (inp->inp_fport != 0 &&
 407                             inp->inp_fport != uh->uh_sport)
 408                                 continue;
 409
 410                         INP_RLOCK(inp);
 411
 412                         /*
 413                          * Handle socket delivery policy for any-source
 414                          * and source-specific multicast. [RFC3678]
 415                          */
 416                         imo = inp->inp_moptions;
 417                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
 418                             imo != NULL) {
 419                                 struct sockaddr_in       sin;
 420                                 struct in_msource       *ims;
 421                                 int                      blocked, mode;
 422                                 size_t                   idx;
 423
 424                                 bzero(&sin, sizeof(struct sockaddr_in));
 425                                 sin.sin_len = sizeof(struct sockaddr_in);
 426                                 sin.sin_family = AF_INET;
 427                                 sin.sin_addr = ip->ip_dst;
 428
 429                                 blocked = 0;
 430                                 idx = imo_match_group(imo, ifp,
 431                                     (struct sockaddr *)&sin);
 432                                 if (idx == -1) {
 433                                         /*
 434                                          * No group membership for this socket.
 435                                          * Do not bump udps_noportbcast, as
 436                                          * this will happen further down.
 437                                          */
 438                                         blocked++;
 439                                 } else {
 440                                         /*
 441                                          * Check for a multicast source filter
 442                                          * entry on this socket for this group.
 443                                          * MCAST_EXCLUDE is the default
 444                                          * behaviour.  It means default accept;
 445                                          * entries, if present, denote sources
 446                                          * to be excluded from delivery.
 447                                          */
 448                                         ims = imo_match_source(imo, idx,
 449                                             (struct sockaddr *)&udp_in);
 450                                         mode = imo->imo_mfilters[idx].imf_fmode;
 451                                         if ((ims != NULL &&
 452                                              mode == MCAST_EXCLUDE) ||
 453                                             (ims == NULL &&
 454                                              mode == MCAST_INCLUDE)) {
 455 #ifdef DIAGNOSTIC
 456                                                 if (bootverbose) {
 457                                                         printf("%s: blocked by"
 458                                                             " source filter\n",
 459                                                             __func__);
 460                                                 }
 461 #endif
 462                                                 udpstat.udps_filtermcast++;
 463                                                 blocked++;
 464                                         }
 465                                 }
 466                                 if (blocked != 0) {
 467                                         INP_RUNLOCK(inp);
 468                                         continue;
 469                                 }
 470                         }
 471                         if (last != NULL) {
 472                                 struct mbuf *n;
 473
 474                                 n = m_copy(m, 0, M_COPYALL);
 475                                 if (n != NULL)
 476                                         udp_append(last, ip, n, iphlen +
 477                                             sizeof(struct udphdr), &udp_in);
 478                                 INP_RUNLOCK(last);
 479                         }
 480                         last = inp;
 481                         /*
 482                          * Don't look for additional matches if this one does
 483                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 484                          * socket options set.  This heuristic avoids
 485                          * searching through all pcbs in the common case of a
 486                          * non-shared port.  It assumes that an application
 487                          * will never clear these options after setting them.
 488                          */
 489                         if ((last->inp_socket->so_options &
 490                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 491                                 break;
 492                 }
 493
 494                 if (last == NULL) {
 495                         /*
 496                          * No matching pcb found; discard datagram.  (No need
 497                          * to send an ICMP Port Unreachable for a broadcast
 498                          * or multicast datgram.)
 499                          */
 500                         udpstat.udps_noportbcast++;
 501                         goto badheadlocked;
 502                 }
 503                 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
 504                     &udp_in);
 505                 INP_RUNLOCK(last);
 506                 INP_INFO_RUNLOCK(&udbinfo);
 507                 return;
 508         }
 509
 510         /*
 511          * Locate pcb for datagram.
 512          */
 513         inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
 514             ip->ip_dst, uh->uh_dport, 1, ifp);
 515         if (inp == NULL) {
 516                 if (udp_log_in_vain) {
 517                         char buf[4*sizeof "123"];
 518
 519                         strcpy(buf, inet_ntoa(ip->ip_dst));
 520                         log(LOG_INFO,
 521                             "Connection attempt to UDP %s:%d from %s:%d\n",
 522                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 523                             ntohs(uh->uh_sport));
 524                 }
 525                 udpstat.udps_noport++;
 526                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 527                         udpstat.udps_noportbcast++;
 528                         goto badheadlocked;
 529                 }
 530                 if (udp_blackhole)
 531                         goto badheadlocked;
 532                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 533                         goto badheadlocked;
 534                 *ip = save_ip;
 535                 ip->ip_len += iphlen;
 536                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 537                 INP_INFO_RUNLOCK(&udbinfo);
 538                 return;
 539         }
 540
 541         /*
 542          * Check the minimum TTL for socket.
 543          */
 544         INP_RLOCK(inp);
 545         INP_INFO_RUNLOCK(&udbinfo);
 546         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 547                 INP_RUNLOCK(inp);
 548                 goto badunlocked;
 549         }
 550         udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
 551         INP_RUNLOCK(inp);
 552         return;
 553
 554 badheadlocked:
 555         if (inp)
 556                 INP_RUNLOCK(inp);
 557         INP_INFO_RUNLOCK(&udbinfo);
 558 badunlocked:
 559         m_freem(m);
 560 }
 561
 562 /*
 563  * Notify a udp user of an asynchronous error; just wake up so that they can
 564  * collect error status.
 565  */
 566 struct inpcb *
 567 udp_notify(struct inpcb *inp, int errno)
 568 {
 569
 570         INP_WLOCK_ASSERT(inp);
 571
 572         inp->inp_socket->so_error = errno;
 573         sorwakeup(inp->inp_socket);
 574         sowwakeup(inp->inp_socket);
 575         return (inp);
 576 }
 577
 578 void
 579 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 580 {
 581         struct ip *ip = vip;
 582         struct udphdr *uh;
 583         struct in_addr faddr;
 584         struct inpcb *inp;
 585
 586         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 587         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 588                 return;
 589
 590         /*
 591          * Redirects don't need to be handled up here.
 592          */
 593         if (PRC_IS_REDIRECT(cmd))
 594                 return;
 595
 596         /*
 597          * Hostdead is ugly because it goes linearly through all PCBs.
 598          *
 599          * XXX: We never get this from ICMP, otherwise it makes an excellent
 600          * DoS attack on machines with many connections.
 601          */
 602         if (cmd == PRC_HOSTDEAD)
 603                 ip = NULL;
 604         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 605                 return;
 606         if (ip != NULL) {
 607                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 608                 INP_INFO_RLOCK(&udbinfo);
 609                 inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
 610                     ip->ip_src, uh->uh_sport, 0, NULL);
 611                 if (inp != NULL) {
 612                         INP_WLOCK(inp);
 613                         if (inp->inp_socket != NULL) {
 614                                 udp_notify(inp, inetctlerrmap[cmd]);
 615                         }
 616                         INP_WUNLOCK(inp);
 617                 }
 618                 INP_INFO_RUNLOCK(&udbinfo);
 619         } else
 620                 in_pcbnotifyall(&udbinfo, faddr, inetctlerrmap[cmd],
 621                     udp_notify);
 622 }
 623
 624 static int
 625 udp_pcblist(SYSCTL_HANDLER_ARGS)
 626 {
 627         int error, i, n;
 628         struct inpcb *inp, **inp_list;
 629         inp_gen_t gencnt;
 630         struct xinpgen xig;
 631
 632         /*
 633          * The process of preparing the PCB list is too time-consuming and
 634          * resource-intensive to repeat twice on every request.
 635          */
 636         if (req->oldptr == 0) {
 637                 n = udbinfo.ipi_count;
 638                 req->oldidx = 2 * (sizeof xig)
 639                         + (n + n/8) * sizeof(struct xinpcb);
 640                 return (0);
 641         }
 642
 643         if (req->newptr != 0)
 644                 return (EPERM);
 645
 646         /*
 647          * OK, now we're committed to doing something.
 648          */
 649         INP_INFO_RLOCK(&udbinfo);
 650         gencnt = udbinfo.ipi_gencnt;
 651         n = udbinfo.ipi_count;
 652         INP_INFO_RUNLOCK(&udbinfo);
 653
 654         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 655                 + n * sizeof(struct xinpcb));
 656         if (error != 0)
 657                 return (error);
 658
 659         xig.xig_len = sizeof xig;
 660         xig.xig_count = n;
 661         xig.xig_gen = gencnt;
 662         xig.xig_sogen = so_gencnt;
 663         error = SYSCTL_OUT(req, &xig, sizeof xig);
 664         if (error)
 665                 return (error);
 666
 667         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 668         if (inp_list == 0)
 669                 return (ENOMEM);
 670
 671         INP_INFO_RLOCK(&udbinfo);
 672         for (inp = LIST_FIRST(udbinfo.ipi_listhead), i = 0; inp && i < n;
 673              inp = LIST_NEXT(inp, inp_list)) {
 674                 INP_RLOCK(inp);
 675                 if (inp->inp_gencnt <= gencnt &&
 676                     cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
 677                         inp_list[i++] = inp;
 678                 INP_RUNLOCK(inp);
 679         }
 680         INP_INFO_RUNLOCK(&udbinfo);
 681         n = i;
 682
 683         error = 0;
 684         for (i = 0; i < n; i++) {
 685                 inp = inp_list[i];
 686                 INP_RLOCK(inp);
 687                 if (inp->inp_gencnt <= gencnt) {
 688                         struct xinpcb xi;
 689                         bzero(&xi, sizeof(xi));
 690                         xi.xi_len = sizeof xi;
 691                         /* XXX should avoid extra copy */
 692                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 693                         if (inp->inp_socket)
 694                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 695                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 696                         INP_RUNLOCK(inp);
 697                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 698                 } else
 699                         INP_RUNLOCK(inp);
 700         }
 701         if (!error) {
 702                 /*
 703                  * Give the user an updated idea of our state.  If the
 704                  * generation differs from what we told her before, she knows
 705                  * that something happened while we were processing this
 706                  * request, and it might be necessary to retry.
 707                  */
 708                 INP_INFO_RLOCK(&udbinfo);
 709                 xig.xig_gen = udbinfo.ipi_gencnt;
 710                 xig.xig_sogen = so_gencnt;
 711                 xig.xig_count = udbinfo.ipi_count;
 712                 INP_INFO_RUNLOCK(&udbinfo);
 713                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 714         }
 715         free(inp_list, M_TEMP);
 716         return (error);
 717 }
 718
 719 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
 720     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 721
 722 static int
 723 udp_getcred(SYSCTL_HANDLER_ARGS)
 724 {
 725         struct xucred xuc;
 726         struct sockaddr_in addrs[2];
 727         struct inpcb *inp;
 728         int error;
 729
 730         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 731         if (error)
 732                 return (error);
 733         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 734         if (error)
 735                 return (error);
 736         INP_INFO_RLOCK(&udbinfo);
 737         inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 738                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
 739         if (inp != NULL) {
 740                 INP_RLOCK(inp);
 741                 INP_INFO_RUNLOCK(&udbinfo);
 742                 if (inp->inp_socket == NULL)
 743                         error = ENOENT;
 744                 if (error == 0)
 745                         error = cr_canseesocket(req->td->td_ucred,
 746                             inp->inp_socket);
 747                 if (error == 0)
 748                         cru2x(inp->inp_socket->so_cred, &xuc);
 749                 INP_RUNLOCK(inp);
 750         } else {
 751                 INP_INFO_RUNLOCK(&udbinfo);
 752                 error = ENOENT;
 753         }
 754         if (error == 0)
 755                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 756         return (error);
 757 }
 758
 759 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 760     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 761     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 762
 763 static int
 764 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
 765     struct mbuf *control, struct thread *td)
 766 {
 767         struct udpiphdr *ui;
 768         int len = m->m_pkthdr.len;
 769         struct in_addr faddr, laddr;
 770         struct cmsghdr *cm;
 771         struct sockaddr_in *sin, src;
 772         int error = 0;
 773         int ipflags;
 774         u_short fport, lport;
 775         int unlock_udbinfo;
 776
 777         /*
 778          * udp_output() may need to temporarily bind or connect the current
 779          * inpcb.  As such, we don't know up front whether we will need the
 780          * pcbinfo lock or not.  Do any work to decide what is needed up
 781          * front before acquiring any locks.
 782          */
 783         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 784                 if (control)
 785                         m_freem(control);
 786                 m_freem(m);
 787                 return (EMSGSIZE);
 788         }
 789
 790         src.sin_family = 0;
 791         if (control != NULL) {
 792                 /*
 793                  * XXX: Currently, we assume all the optional information is
 794                  * stored in a single mbuf.
 795                  */
 796                 if (control->m_next) {
 797                         m_freem(control);
 798                         m_freem(m);
 799                         return (EINVAL);
 800                 }
 801                 for (; control->m_len > 0;
 802                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 803                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 804                         cm = mtod(control, struct cmsghdr *);
 805                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 806                             || cm->cmsg_len > control->m_len) {
 807                                 error = EINVAL;
 808                                 break;
 809                         }
 810                         if (cm->cmsg_level != IPPROTO_IP)
 811                                 continue;
 812
 813                         switch (cm->cmsg_type) {
 814                         case IP_SENDSRCADDR:
 815                                 if (cm->cmsg_len !=
 816                                     CMSG_LEN(sizeof(struct in_addr))) {
 817                                         error = EINVAL;
 818                                         break;
 819                                 }
 820                                 bzero(&src, sizeof(src));
 821                                 src.sin_family = AF_INET;
 822                                 src.sin_len = sizeof(src);
 823                                 src.sin_port = inp->inp_lport;
 824                                 src.sin_addr =
 825                                     *(struct in_addr *)CMSG_DATA(cm);
 826                                 break;
 827
 828                         default:
 829                                 error = ENOPROTOOPT;
 830                                 break;
 831                         }
 832                         if (error)
 833                                 break;
 834                 }
 835                 m_freem(control);
 836         }
 837         if (error) {
 838                 m_freem(m);
 839                 return (error);
 840         }
 841
 842         if (src.sin_family == AF_INET || addr != NULL) {
 843                 INP_INFO_WLOCK(&udbinfo);
 844                 INP_WLOCK(inp);
 845                 unlock_udbinfo = 1;
 846         } else {
 847                 unlock_udbinfo = 0;
 848                 INP_RLOCK(inp);
 849         }
 850
 851 #ifdef MAC
 852         mac_inpcb_create_mbuf(inp, m);
 853 #endif
 854
 855         /*
 856          * If the IP_SENDSRCADDR control message was specified, override the
 857          * source address for this datagram.  Its use is invalidated if the
 858          * address thus specified is incomplete or clobbers other inpcbs.
 859          */
 860         laddr = inp->inp_laddr;
 861         lport = inp->inp_lport;
 862         if (src.sin_family == AF_INET) {
 863                 INP_INFO_LOCK_ASSERT(&udbinfo);
 864                 if ((lport == 0) ||
 865                     (laddr.s_addr == INADDR_ANY &&
 866                      src.sin_addr.s_addr == INADDR_ANY)) {
 867                         error = EINVAL;
 868                         goto release;
 869                 }
 870                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
 871                     &laddr.s_addr, &lport, td->td_ucred);
 872                 if (error)
 873                         goto release;
 874         }
 875
 876         if (addr) {
 877                 INP_INFO_LOCK_ASSERT(&udbinfo);
 878                 INP_LOCK_ASSERT(inp);
 879                 sin = (struct sockaddr_in *)addr;
 880                 if (jailed(td->td_ucred))
 881                         prison_remote_ip(td->td_ucred, 0,
 882                             &sin->sin_addr.s_addr);
 883                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 884                         error = EISCONN;
 885                         goto release;
 886                 }
 887                 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr, &lport,
 888                     &faddr.s_addr, &fport, NULL, td->td_ucred);
 889                 if (error)
 890                         goto release;
 891
 892                 /* Commit the local port if newly assigned. */
 893                 if (inp->inp_laddr.s_addr == INADDR_ANY &&
 894                     inp->inp_lport == 0) {
 895                         INP_INFO_WLOCK_ASSERT(&udbinfo);
 896                         INP_WLOCK_ASSERT(inp);
 897                         /*
 898                          * Remember addr if jailed, to prevent rebinding.
 899                          */
 900                         if (jailed(td->td_ucred))
 901                                 inp->inp_laddr = laddr;
 902                         inp->inp_lport = lport;
 903                         if (in_pcbinshash(inp) != 0) {
 904                                 inp->inp_lport = 0;
 905                                 error = EAGAIN;
 906                                 goto release;
 907                         }
 908                         inp->inp_flags |= INP_ANONPORT;
 909                 }
 910         } else {
 911                 INP_LOCK_ASSERT(inp);
 912                 faddr = inp->inp_faddr;
 913                 fport = inp->inp_fport;
 914                 if (faddr.s_addr == INADDR_ANY) {
 915                         error = ENOTCONN;
 916                         goto release;
 917                 }
 918         }
 919
 920         /*
 921          * Calculate data length and get a mbuf for UDP, IP, and possible
 922          * link-layer headers.  Immediate slide the data pointer back forward
 923          * since we won't use that space at this layer.
 924          */
 925         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
 926         if (m == NULL) {
 927                 error = ENOBUFS;
 928                 goto release;
 929         }
 930         m->m_data += max_linkhdr;
 931         m->m_len -= max_linkhdr;
 932         m->m_pkthdr.len -= max_linkhdr;
 933
 934         /*
 935          * Fill in mbuf with extended UDP header and addresses and length put
 936          * into network format.
 937          */
 938         ui = mtod(m, struct udpiphdr *);
 939         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
 940         ui->ui_pr = IPPROTO_UDP;
 941         ui->ui_src = laddr;
 942         ui->ui_dst = faddr;
 943         ui->ui_sport = lport;
 944         ui->ui_dport = fport;
 945         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
 946
 947         /*
 948          * Set the Don't Fragment bit in the IP header.
 949          */
 950         if (inp->inp_flags & INP_DONTFRAG) {
 951                 struct ip *ip;
 952
 953                 ip = (struct ip *)&ui->ui_i;
 954                 ip->ip_off |= IP_DF;
 955         }
 956
 957         ipflags = 0;
 958         if (inp->inp_socket->so_options & SO_DONTROUTE)
 959                 ipflags |= IP_ROUTETOIF;
 960         if (inp->inp_socket->so_options & SO_BROADCAST)
 961                 ipflags |= IP_ALLOWBROADCAST;
 962         if (inp->inp_flags & INP_ONESBCAST)
 963                 ipflags |= IP_SENDONES;
 964
 965         /*
 966          * Set up checksum and output datagram.
 967          */
 968         if (udp_cksum) {
 969                 if (inp->inp_flags & INP_ONESBCAST)
 970                         faddr.s_addr = INADDR_BROADCAST;
 971                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
 972                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
 973                 m->m_pkthdr.csum_flags = CSUM_UDP;
 974                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 975         } else
 976                 ui->ui_sum = 0;
 977         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
 978         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
 979         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
 980         udpstat.udps_opackets++;
 981
 982         if (unlock_udbinfo)
 983                 INP_INFO_WUNLOCK(&udbinfo);
 984         error = ip_output(m, inp->inp_options, NULL, ipflags,
 985             inp->inp_moptions, inp);
 986         if (unlock_udbinfo)
 987                 INP_WUNLOCK(inp);
 988         else
 989                 INP_RUNLOCK(inp);
 990         return (error);
 991
 992 release:
 993         if (unlock_udbinfo) {
 994                 INP_INFO_WUNLOCK(&udbinfo);
 995                 INP_WUNLOCK(inp);
 996         } else
 997                 INP_RUNLOCK(inp);
 998         m_freem(m);
 999         return (error);
1000 }
1001
1002 static void
1003 udp_abort(struct socket *so)
1004 {
1005         struct inpcb *inp;
1006
1007         inp = sotoinpcb(so);
1008         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1009         INP_INFO_WLOCK(&udbinfo);
1010         INP_WLOCK(inp);
1011         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1012                 in_pcbdisconnect(inp);
1013                 inp->inp_laddr.s_addr = INADDR_ANY;
1014                 soisdisconnected(so);
1015         }
1016         INP_WUNLOCK(inp);
1017         INP_INFO_WUNLOCK(&udbinfo);
1018 }
1019
1020 static int
1021 udp_attach(struct socket *so, int proto, struct thread *td)
1022 {
1023         struct inpcb *inp;
1024         int error;
1025
1026         inp = sotoinpcb(so);
1027         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1028         error = soreserve(so, udp_sendspace, udp_recvspace);
1029         if (error)
1030                 return (error);
1031         INP_INFO_WLOCK(&udbinfo);
1032         error = in_pcballoc(so, &udbinfo);
1033         if (error) {
1034                 INP_INFO_WUNLOCK(&udbinfo);
1035                 return (error);
1036         }
1037
1038         inp = (struct inpcb *)so->so_pcb;
1039         INP_INFO_WUNLOCK(&udbinfo);
1040         inp->inp_vflag |= INP_IPV4;
1041         inp->inp_ip_ttl = ip_defttl;
1042         INP_WUNLOCK(inp);
1043         return (0);
1044 }
1045
1046 static int
1047 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1048 {
1049         struct inpcb *inp;
1050         int error;
1051
1052         inp = sotoinpcb(so);
1053         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1054         INP_INFO_WLOCK(&udbinfo);
1055         INP_WLOCK(inp);
1056         error = in_pcbbind(inp, nam, td->td_ucred);
1057         INP_WUNLOCK(inp);
1058         INP_INFO_WUNLOCK(&udbinfo);
1059         return (error);
1060 }
1061
1062 static void
1063 udp_close(struct socket *so)
1064 {
1065         struct inpcb *inp;
1066
1067         inp = sotoinpcb(so);
1068         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1069         INP_INFO_WLOCK(&udbinfo);
1070         INP_WLOCK(inp);
1071         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1072                 in_pcbdisconnect(inp);
1073                 inp->inp_laddr.s_addr = INADDR_ANY;
1074                 soisdisconnected(so);
1075         }
1076         INP_WUNLOCK(inp);
1077         INP_INFO_WUNLOCK(&udbinfo);
1078 }
1079
1080 static int
1081 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1082 {
1083         struct inpcb *inp;
1084         int error;
1085         struct sockaddr_in *sin;
1086
1087         inp = sotoinpcb(so);
1088         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1089         INP_INFO_WLOCK(&udbinfo);
1090         INP_WLOCK(inp);
1091         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1092                 INP_WUNLOCK(inp);
1093                 INP_INFO_WUNLOCK(&udbinfo);
1094                 return (EISCONN);
1095         }
1096         sin = (struct sockaddr_in *)nam;
1097         if (jailed(td->td_ucred))
1098                 prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr);
1099         error = in_pcbconnect(inp, nam, td->td_ucred);
1100         if (error == 0)
1101                 soisconnected(so);
1102         INP_WUNLOCK(inp);
1103         INP_INFO_WUNLOCK(&udbinfo);
1104         return (error);
1105 }
1106
1107 static void
1108 udp_detach(struct socket *so)
1109 {
1110         struct inpcb *inp;
1111
1112         inp = sotoinpcb(so);
1113         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1114         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1115             ("udp_detach: not disconnected"));
1116         INP_INFO_WLOCK(&udbinfo);
1117         INP_WLOCK(inp);
1118         in_pcbdetach(inp);
1119         in_pcbfree(inp);
1120         INP_INFO_WUNLOCK(&udbinfo);
1121 }
1122
1123 static int
1124 udp_disconnect(struct socket *so)
1125 {
1126         struct inpcb *inp;
1127
1128         inp = sotoinpcb(so);
1129         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1130         INP_INFO_WLOCK(&udbinfo);
1131         INP_WLOCK(inp);
1132         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1133                 INP_WUNLOCK(inp);
1134                 INP_INFO_WUNLOCK(&udbinfo);
1135                 return (ENOTCONN);
1136         }
1137
1138         in_pcbdisconnect(inp);
1139         inp->inp_laddr.s_addr = INADDR_ANY;
1140         SOCK_LOCK(so);
1141         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1142         SOCK_UNLOCK(so);
1143         INP_WUNLOCK(inp);
1144         INP_INFO_WUNLOCK(&udbinfo);
1145         return (0);
1146 }
1147
1148 static int
1149 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1150     struct mbuf *control, struct thread *td)
1151 {
1152         struct inpcb *inp;
1153
1154         inp = sotoinpcb(so);
1155         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1156         return (udp_output(inp, m, addr, control, td));
1157 }
1158
1159 int
1160 udp_shutdown(struct socket *so)
1161 {
1162         struct inpcb *inp;
1163
1164         inp = sotoinpcb(so);
1165         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1166         INP_WLOCK(inp);
1167         socantsendmore(so);
1168         INP_WUNLOCK(inp);
1169         return (0);
1170 }
1171
1172 struct pr_usrreqs udp_usrreqs = {
1173         .pru_abort =            udp_abort,
1174         .pru_attach =           udp_attach,
1175         .pru_bind =             udp_bind,
1176         .pru_connect =          udp_connect,
1177         .pru_control =          in_control,
1178         .pru_detach =           udp_detach,
1179         .pru_disconnect =       udp_disconnect,
1180         .pru_peeraddr =         in_getpeeraddr,
1181         .pru_send =             udp_send,
1182         .pru_soreceive =        soreceive_dgram,
1183         .pru_sosend =           sosend_dgram,
1184         .pru_shutdown =         udp_shutdown,
1185         .pru_sockaddr =         in_getsockaddr,
1186         .pru_sosetlabel =       in_pcbsosetlabel,
1187         .pru_close =            udp_close,
1188 };