sys/netinet/udp_usrreq.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  30  * $FreeBSD$
  31  */
  32
  33 #include "opt_ipfw.h"
  34 #include "opt_ipsec.h"
  35 #include "opt_inet6.h"
  36 #include "opt_mac.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/domain.h>
  41 #include <sys/eventhandler.h>
  42 #include <sys/jail.h>
  43 #include <sys/kernel.h>
  44 #include <sys/lock.h>
  45 #include <sys/malloc.h>
  46 #include <sys/mbuf.h>
  47 #include <sys/priv.h>
  48 #include <sys/proc.h>
  49 #include <sys/protosw.h>
  50 #include <sys/signalvar.h>
  51 #include <sys/socket.h>
  52 #include <sys/socketvar.h>
  53 #include <sys/sx.h>
  54 #include <sys/sysctl.h>
  55 #include <sys/syslog.h>
  56
  57 #include <vm/uma.h>
  58
  59 #include <net/if.h>
  60 #include <net/route.h>
  61
  62 #include <netinet/in.h>
  63 #include <netinet/in_systm.h>
  64 #include <netinet/in_pcb.h>
  65 #include <netinet/in_var.h>
  66 #include <netinet/ip.h>
  67 #ifdef INET6
  68 #include <netinet/ip6.h>
  69 #endif
  70 #include <netinet/ip_icmp.h>
  71 #include <netinet/icmp_var.h>
  72 #include <netinet/ip_var.h>
  73 #include <netinet/ip_options.h>
  74 #ifdef INET6
  75 #include <netinet6/ip6_var.h>
  76 #endif
  77 #include <netinet/udp.h>
  78 #include <netinet/udp_var.h>
  79
  80 #ifdef FAST_IPSEC
  81 #include <netipsec/ipsec.h>
  82 #endif /*FAST_IPSEC*/
  83
  84 #ifdef IPSEC
  85 #include <netinet6/ipsec.h>
  86 #endif /*IPSEC*/
  87
  88 #include <machine/in_cksum.h>
  89
  90 #include <security/mac/mac_framework.h>
  91
  92 /*
  93  * UDP protocol implementation.
  94  * Per RFC 768, August, 1980.
  95  */
  96
  97 /*
  98  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp
  99  * checksums removes the only data integrety mechanism for packets and
 100  * malformed packets that would otherwise be discarded by bad checksums
 101  * may cause problems (especially for NFS data blocks).
 102  */
 103 #ifndef COMPAT_42
 104 static int      udpcksum = 1;
 105 #else
 106 static int      udpcksum = 0;
 107 #endif
 108 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
 109                 &udpcksum, 0, "");
 110
 111 int     log_in_vain = 0;
 112 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 113     &log_in_vain, 0, "Log all incoming UDP packets");
 114
 115 static int      blackhole = 0;
 116 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 117         &blackhole, 0, "Do not send port unreachables for refused connects");
 118
 119 static int      strict_mcast_mship = 0;
 120 SYSCTL_INT(_net_inet_udp, OID_AUTO, strict_mcast_mship, CTLFLAG_RW,
 121         &strict_mcast_mship, 0, "Only send multicast to member sockets");
 122
 123 struct  inpcbhead udb;          /* from udp_var.h */
 124 #define udb6    udb  /* for KAME src sync over BSD*'s */
 125 struct  inpcbinfo udbinfo;
 126
 127 #ifndef UDBHASHSIZE
 128 #define UDBHASHSIZE 16
 129 #endif
 130
 131 struct  udpstat udpstat;        /* from udp_var.h */
 132 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
 133     &udpstat, udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 134
 135 static void udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n,
 136                 int off, struct sockaddr_in *udp_in);
 137
 138 static void udp_detach(struct socket *so);
 139 static  int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 140                 struct mbuf *, struct thread *);
 141
 142 static void
 143 udp_zone_change(void *tag)
 144 {
 145
 146         uma_zone_set_max(udbinfo.ipi_zone, maxsockets);
 147 }
 148
 149 static int
 150 udp_inpcb_init(void *mem, int size, int flags)
 151 {
 152         struct inpcb *inp = mem;
 153
 154         INP_LOCK_INIT(inp, "inp", "udpinp");
 155         return (0);
 156 }
 157
 158 void
 159 udp_init()
 160 {
 161         INP_INFO_LOCK_INIT(&udbinfo, "udp");
 162         LIST_INIT(&udb);
 163         udbinfo.listhead = &udb;
 164         udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask);
 165         udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB,
 166                                         &udbinfo.porthashmask);
 167         udbinfo.ipi_zone = uma_zcreate("udpcb", sizeof(struct inpcb), NULL,
 168             NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 169         uma_zone_set_max(udbinfo.ipi_zone, maxsockets);
 170         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 171                 EVENTHANDLER_PRI_ANY);
 172 }
 173
 174 void
 175 udp_input(m, off)
 176         register struct mbuf *m;
 177         int off;
 178 {
 179         int iphlen = off;
 180         register struct ip *ip;
 181         register struct udphdr *uh;
 182         register struct inpcb *inp;
 183         int len;
 184         struct ip save_ip;
 185         struct sockaddr_in udp_in;
 186 #ifdef IPFIREWALL_FORWARD
 187         struct m_tag *fwd_tag;
 188 #endif
 189
 190         udpstat.udps_ipackets++;
 191
 192         /*
 193          * Strip IP options, if any; should skip this,
 194          * make available to user, and use on returned packets,
 195          * but we don't yet have a way to check the checksum
 196          * with options still present.
 197          */
 198         if (iphlen > sizeof (struct ip)) {
 199                 ip_stripoptions(m, (struct mbuf *)0);
 200                 iphlen = sizeof(struct ip);
 201         }
 202
 203         /*
 204          * Get IP and UDP header together in first mbuf.
 205          */
 206         ip = mtod(m, struct ip *);
 207         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 208                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 209                         udpstat.udps_hdrops++;
 210                         return;
 211                 }
 212                 ip = mtod(m, struct ip *);
 213         }
 214         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 215
 216         /* destination port of 0 is illegal, based on RFC768. */
 217         if (uh->uh_dport == 0)
 218                 goto badunlocked;
 219
 220         /*
 221          * Construct sockaddr format source address.
 222          * Stuff source address and datagram in user buffer.
 223          */
 224         bzero(&udp_in, sizeof(udp_in));
 225         udp_in.sin_len = sizeof(udp_in);
 226         udp_in.sin_family = AF_INET;
 227         udp_in.sin_port = uh->uh_sport;
 228         udp_in.sin_addr = ip->ip_src;
 229
 230         /*
 231          * Make mbuf data length reflect UDP length.
 232          * If not enough data to reflect UDP length, drop.
 233          */
 234         len = ntohs((u_short)uh->uh_ulen);
 235         if (ip->ip_len != len) {
 236                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 237                         udpstat.udps_badlen++;
 238                         goto badunlocked;
 239                 }
 240                 m_adj(m, len - ip->ip_len);
 241                 /* ip->ip_len = len; */
 242         }
 243         /*
 244          * Save a copy of the IP header in case we want restore it
 245          * for sending an ICMP error message in response.
 246          */
 247         if (!blackhole)
 248                 save_ip = *ip;
 249
 250         /*
 251          * Checksum extended UDP header and data.
 252          */
 253         if (uh->uh_sum) {
 254                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 255                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 256                                 uh->uh_sum = m->m_pkthdr.csum_data;
 257                         else
 258                                 uh->uh_sum = in_pseudo(ip->ip_src.s_addr,
 259                                     ip->ip_dst.s_addr, htonl((u_short)len +
 260                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 261                         uh->uh_sum ^= 0xffff;
 262                 } else {
 263                         char b[9];
 264                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 265                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 266                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 267                         uh->uh_sum = in_cksum(m, len + sizeof (struct ip));
 268                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 269                 }
 270                 if (uh->uh_sum) {
 271                         udpstat.udps_badsum++;
 272                         m_freem(m);
 273                         return;
 274                 }
 275         } else
 276                 udpstat.udps_nosum++;
 277
 278 #ifdef IPFIREWALL_FORWARD
 279         /* Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain. */
 280         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 281
 282         if (fwd_tag != NULL) {
 283                 struct sockaddr_in *next_hop;
 284
 285                 /* Do the hack. */
 286                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 287                 ip->ip_dst = next_hop->sin_addr;
 288                 uh->uh_dport = ntohs(next_hop->sin_port);
 289                 /* Remove the tag from the packet.  We don't need it anymore. */
 290                 m_tag_delete(m, fwd_tag);
 291         }
 292 #endif
 293
 294         INP_INFO_RLOCK(&udbinfo);
 295
 296         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 297             in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
 298                 struct inpcb *last;
 299                 /*
 300                  * Deliver a multicast or broadcast datagram to *all* sockets
 301                  * for which the local and remote addresses and ports match
 302                  * those of the incoming datagram.  This allows more than
 303                  * one process to receive multi/broadcasts on the same port.
 304                  * (This really ought to be done for unicast datagrams as
 305                  * well, but that would cause problems with existing
 306                  * applications that open both address-specific sockets and
 307                  * a wildcard socket listening to the same port -- they would
 308                  * end up receiving duplicates of every unicast datagram.
 309                  * Those applications open the multiple sockets to overcome an
 310                  * inadequacy of the UDP socket interface, but for backwards
 311                  * compatibility we avoid the problem here rather than
 312                  * fixing the interface.  Maybe 4.5BSD will remedy this?)
 313                  */
 314
 315                 /*
 316                  * Locate pcb(s) for datagram.
 317                  * (Algorithm copied from raw_intr().)
 318                  */
 319                 last = NULL;
 320                 LIST_FOREACH(inp, &udb, inp_list) {
 321                         if (inp->inp_lport != uh->uh_dport)
 322                                 continue;
 323 #ifdef INET6
 324                         if ((inp->inp_vflag & INP_IPV4) == 0)
 325                                 continue;
 326 #endif
 327                         if (inp->inp_laddr.s_addr != INADDR_ANY) {
 328                                 if (inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 329                                         continue;
 330                         }
 331                         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 332                                 if (inp->inp_faddr.s_addr !=
 333                                     ip->ip_src.s_addr ||
 334                                     inp->inp_fport != uh->uh_sport)
 335                                         continue;
 336                         }
 337                         INP_LOCK(inp);
 338
 339                         /*
 340                          * Check multicast packets to make sure they are only
 341                          * sent to sockets with multicast memberships for the
 342                          * packet's destination address and arrival interface
 343                          */
 344 #define MSHIP(_inp, n) ((_inp)->inp_moptions->imo_membership[(n)])
 345 #define NMSHIPS(_inp) ((_inp)->inp_moptions->imo_num_memberships)
 346                         if (strict_mcast_mship && inp->inp_moptions != NULL) {
 347                                 int mship, foundmship = 0;
 348
 349                                 for (mship = 0; mship < NMSHIPS(inp); mship++) {
 350                                         if (MSHIP(inp, mship)->inm_addr.s_addr
 351                                             == ip->ip_dst.s_addr &&
 352                                             MSHIP(inp, mship)->inm_ifp
 353                                             == m->m_pkthdr.rcvif) {
 354                                                 foundmship = 1;
 355                                                 break;
 356                                         }
 357                                 }
 358                                 if (foundmship == 0) {
 359                                         INP_UNLOCK(inp);
 360                                         continue;
 361                                 }
 362                         }
 363 #undef NMSHIPS
 364 #undef MSHIP
 365                         if (last != NULL) {
 366                                 struct mbuf *n;
 367
 368                                 n = m_copy(m, 0, M_COPYALL);
 369                                 if (n != NULL)
 370                                         udp_append(last, ip, n,
 371                                                    iphlen +
 372                                                    sizeof(struct udphdr),
 373                                                    &udp_in);
 374                                 INP_UNLOCK(last);
 375                         }
 376                         last = inp;
 377                         /*
 378                          * Don't look for additional matches if this one does
 379                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 380                          * socket options set.  This heuristic avoids searching
 381                          * through all pcbs in the common case of a non-shared
 382                          * port.  It assumes that an application will never
 383                          * clear these options after setting them.
 384                          */
 385                         if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR)) == 0)
 386                                 break;
 387                 }
 388
 389                 if (last == NULL) {
 390                         /*
 391                          * No matching pcb found; discard datagram.
 392                          * (No need to send an ICMP Port Unreachable
 393                          * for a broadcast or multicast datgram.)
 394                          */
 395                         udpstat.udps_noportbcast++;
 396                         goto badheadlocked;
 397                 }
 398                 udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
 399                     &udp_in);
 400                 INP_UNLOCK(last);
 401                 INP_INFO_RUNLOCK(&udbinfo);
 402                 return;
 403         }
 404         /*
 405          * Locate pcb for datagram.
 406          */
 407         inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
 408             ip->ip_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 409         if (inp == NULL) {
 410                 if (log_in_vain) {
 411                         char buf[4*sizeof "123"];
 412
 413                         strcpy(buf, inet_ntoa(ip->ip_dst));
 414                         log(LOG_INFO,
 415                             "Connection attempt to UDP %s:%d from %s:%d\n",
 416                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 417                             ntohs(uh->uh_sport));
 418                 }
 419                 udpstat.udps_noport++;
 420                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 421                         udpstat.udps_noportbcast++;
 422                         goto badheadlocked;
 423                 }
 424                 if (blackhole)
 425                         goto badheadlocked;
 426                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 427                         goto badheadlocked;
 428                 *ip = save_ip;
 429                 ip->ip_len += iphlen;
 430                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 431                 INP_INFO_RUNLOCK(&udbinfo);
 432                 return;
 433         }
 434         INP_LOCK(inp);
 435         /* Check the minimum TTL for socket. */
 436         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl)
 437                 goto badheadlocked;
 438         udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
 439         INP_UNLOCK(inp);
 440         INP_INFO_RUNLOCK(&udbinfo);
 441         return;
 442
 443 badheadlocked:
 444         if (inp)
 445                 INP_UNLOCK(inp);
 446         INP_INFO_RUNLOCK(&udbinfo);
 447 badunlocked:
 448         m_freem(m);
 449         return;
 450 }
 451
 452 /*
 453  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 454  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 455  * contains the source address.  If the socket ends up being an IPv6 socket,
 456  * udp_append() will convert to a sockaddr_in6 before passing the address
 457  * into the socket code.
 458  */
 459 static void
 460 udp_append(inp, ip, n, off, udp_in)
 461         struct inpcb *inp;
 462         struct ip *ip;
 463         struct mbuf *n;
 464         int off;
 465         struct sockaddr_in *udp_in;
 466 {
 467         struct sockaddr *append_sa;
 468         struct socket *so;
 469         struct mbuf *opts = 0;
 470 #ifdef INET6
 471         struct sockaddr_in6 udp_in6;
 472 #endif
 473
 474         INP_LOCK_ASSERT(inp);
 475
 476 #if defined(IPSEC) || defined(FAST_IPSEC)
 477         /* check AH/ESP integrity. */
 478         if (ipsec4_in_reject(n, inp)) {
 479 #ifdef IPSEC
 480                 ipsecstat.in_polvio++;
 481 #endif /*IPSEC*/
 482                 m_freem(n);
 483                 return;
 484         }
 485 #endif /*IPSEC || FAST_IPSEC*/
 486 #ifdef MAC
 487         if (mac_check_inpcb_deliver(inp, n) != 0) {
 488                 m_freem(n);
 489                 return;
 490         }
 491 #endif
 492         if (inp->inp_flags & INP_CONTROLOPTS ||
 493             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 494 #ifdef INET6
 495                 if (inp->inp_vflag & INP_IPV6) {
 496                         int savedflags;
 497
 498                         savedflags = inp->inp_flags;
 499                         inp->inp_flags &= ~INP_UNMAPPABLEOPTS;
 500                         ip6_savecontrol(inp, n, &opts);
 501                         inp->inp_flags = savedflags;
 502                 } else
 503 #endif
 504                 ip_savecontrol(inp, &opts, ip, n);
 505         }
 506 #ifdef INET6
 507         if (inp->inp_vflag & INP_IPV6) {
 508                 bzero(&udp_in6, sizeof(udp_in6));
 509                 udp_in6.sin6_len = sizeof(udp_in6);
 510                 udp_in6.sin6_family = AF_INET6;
 511                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 512                 append_sa = (struct sockaddr *)&udp_in6;
 513         } else
 514 #endif
 515         append_sa = (struct sockaddr *)udp_in;
 516         m_adj(n, off);
 517
 518         so = inp->inp_socket;
 519         SOCKBUF_LOCK(&so->so_rcv);
 520         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 521                 m_freem(n);
 522                 if (opts)
 523                         m_freem(opts);
 524                 udpstat.udps_fullsock++;
 525                 SOCKBUF_UNLOCK(&so->so_rcv);
 526         } else
 527                 sorwakeup_locked(so);
 528 }
 529
 530 /*
 531  * Notify a udp user of an asynchronous error;
 532  * just wake up so that he can collect error status.
 533  */
 534 struct inpcb *
 535 udp_notify(inp, errno)
 536         register struct inpcb *inp;
 537         int errno;
 538 {
 539         inp->inp_socket->so_error = errno;
 540         sorwakeup(inp->inp_socket);
 541         sowwakeup(inp->inp_socket);
 542         return inp;
 543 }
 544
 545 void
 546 udp_ctlinput(cmd, sa, vip)
 547         int cmd;
 548         struct sockaddr *sa;
 549         void *vip;
 550 {
 551         struct ip *ip = vip;
 552         struct udphdr *uh;
 553         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 554         struct in_addr faddr;
 555         struct inpcb *inp;
 556
 557         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 558         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 559                 return;
 560
 561         /*
 562          * Redirects don't need to be handled up here.
 563          */
 564         if (PRC_IS_REDIRECT(cmd))
 565                 return;
 566         /*
 567          * Hostdead is ugly because it goes linearly through all PCBs.
 568          * XXX: We never get this from ICMP, otherwise it makes an
 569          * excellent DoS attack on machines with many connections.
 570          */
 571         if (cmd == PRC_HOSTDEAD)
 572                 ip = 0;
 573         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 574                 return;
 575         if (ip) {
 576                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 577                 INP_INFO_RLOCK(&udbinfo);
 578                 inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
 579                     ip->ip_src, uh->uh_sport, 0, NULL);
 580                 if (inp != NULL) {
 581                         INP_LOCK(inp);
 582                         if (inp->inp_socket != NULL) {
 583                                 (*notify)(inp, inetctlerrmap[cmd]);
 584                         }
 585                         INP_UNLOCK(inp);
 586                 }
 587                 INP_INFO_RUNLOCK(&udbinfo);
 588         } else
 589                 in_pcbnotifyall(&udbinfo, faddr, inetctlerrmap[cmd], notify);
 590 }
 591
 592 static int
 593 udp_pcblist(SYSCTL_HANDLER_ARGS)
 594 {
 595         int error, i, n;
 596         struct inpcb *inp, **inp_list;
 597         inp_gen_t gencnt;
 598         struct xinpgen xig;
 599
 600         /*
 601          * The process of preparing the TCB list is too time-consuming and
 602          * resource-intensive to repeat twice on every request.
 603          */
 604         if (req->oldptr == 0) {
 605                 n = udbinfo.ipi_count;
 606                 req->oldidx = 2 * (sizeof xig)
 607                         + (n + n/8) * sizeof(struct xinpcb);
 608                 return 0;
 609         }
 610
 611         if (req->newptr != 0)
 612                 return EPERM;
 613
 614         /*
 615          * OK, now we're committed to doing something.
 616          */
 617         INP_INFO_RLOCK(&udbinfo);
 618         gencnt = udbinfo.ipi_gencnt;
 619         n = udbinfo.ipi_count;
 620         INP_INFO_RUNLOCK(&udbinfo);
 621
 622         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 623                 + n * sizeof(struct xinpcb));
 624         if (error != 0)
 625                 return (error);
 626
 627         xig.xig_len = sizeof xig;
 628         xig.xig_count = n;
 629         xig.xig_gen = gencnt;
 630         xig.xig_sogen = so_gencnt;
 631         error = SYSCTL_OUT(req, &xig, sizeof xig);
 632         if (error)
 633                 return error;
 634
 635         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 636         if (inp_list == 0)
 637                 return ENOMEM;
 638
 639         INP_INFO_RLOCK(&udbinfo);
 640         for (inp = LIST_FIRST(udbinfo.listhead), i = 0; inp && i < n;
 641              inp = LIST_NEXT(inp, inp_list)) {
 642                 INP_LOCK(inp);
 643                 if (inp->inp_gencnt <= gencnt &&
 644                     cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
 645                         inp_list[i++] = inp;
 646                 INP_UNLOCK(inp);
 647         }
 648         INP_INFO_RUNLOCK(&udbinfo);
 649         n = i;
 650
 651         error = 0;
 652         for (i = 0; i < n; i++) {
 653                 inp = inp_list[i];
 654                 INP_LOCK(inp);
 655                 if (inp->inp_gencnt <= gencnt) {
 656                         struct xinpcb xi;
 657                         bzero(&xi, sizeof(xi));
 658                         xi.xi_len = sizeof xi;
 659                         /* XXX should avoid extra copy */
 660                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 661                         if (inp->inp_socket)
 662                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 663                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 664                         INP_UNLOCK(inp);
 665                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 666                 } else
 667                         INP_UNLOCK(inp);
 668         }
 669         if (!error) {
 670                 /*
 671                  * Give the user an updated idea of our state.
 672                  * If the generation differs from what we told
 673                  * her before, she knows that something happened
 674                  * while we were processing this request, and it
 675                  * might be necessary to retry.
 676                  */
 677                 INP_INFO_RLOCK(&udbinfo);
 678                 xig.xig_gen = udbinfo.ipi_gencnt;
 679                 xig.xig_sogen = so_gencnt;
 680                 xig.xig_count = udbinfo.ipi_count;
 681                 INP_INFO_RUNLOCK(&udbinfo);
 682                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 683         }
 684         free(inp_list, M_TEMP);
 685         return error;
 686 }
 687
 688 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
 689             udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 690
 691 static int
 692 udp_getcred(SYSCTL_HANDLER_ARGS)
 693 {
 694         struct xucred xuc;
 695         struct sockaddr_in addrs[2];
 696         struct inpcb *inp;
 697         int error;
 698
 699         error = priv_check_cred(req->td->td_ucred, PRIV_NETINET_GETCRED,
 700             SUSER_ALLOWJAIL);
 701         if (error)
 702                 return (error);
 703         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 704         if (error)
 705                 return (error);
 706         INP_INFO_RLOCK(&udbinfo);
 707         inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 708                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
 709         if (inp == NULL || inp->inp_socket == NULL) {
 710                 error = ENOENT;
 711                 goto out;
 712         }
 713         error = cr_canseesocket(req->td->td_ucred, inp->inp_socket);
 714         if (error)
 715                 goto out;
 716         cru2x(inp->inp_socket->so_cred, &xuc);
 717 out:
 718         INP_INFO_RUNLOCK(&udbinfo);
 719         if (error == 0)
 720                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 721         return (error);
 722 }
 723
 724 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 725     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 726     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 727
 728 static int
 729 udp_output(inp, m, addr, control, td)
 730         register struct inpcb *inp;
 731         struct mbuf *m;
 732         struct sockaddr *addr;
 733         struct mbuf *control;
 734         struct thread *td;
 735 {
 736         register struct udpiphdr *ui;
 737         register int len = m->m_pkthdr.len;
 738         struct in_addr faddr, laddr;
 739         struct cmsghdr *cm;
 740         struct sockaddr_in *sin, src;
 741         int error = 0;
 742         int ipflags;
 743         u_short fport, lport;
 744         int unlock_udbinfo;
 745
 746         /*
 747          * udp_output() may need to temporarily bind or connect the current
 748          * inpcb.  As such, we don't know up front what inpcb locks we will
 749          * need.  Do any work to decide what is needed up front before
 750          * acquiring locks.
 751          */
 752         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 753                 if (control)
 754                         m_freem(control);
 755                 m_freem(m);
 756                 return EMSGSIZE;
 757         }
 758
 759         src.sin_addr.s_addr = INADDR_ANY;
 760         if (control != NULL) {
 761                 /*
 762                  * XXX: Currently, we assume all the optional information
 763                  * is stored in a single mbuf.
 764                  */
 765                 if (control->m_next) {
 766                         m_freem(control);
 767                         m_freem(m);
 768                         return EINVAL;
 769                 }
 770                 for (; control->m_len > 0;
 771                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 772                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 773                         cm = mtod(control, struct cmsghdr *);
 774                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0 ||
 775                             cm->cmsg_len > control->m_len) {
 776                                 error = EINVAL;
 777                                 break;
 778                         }
 779                         if (cm->cmsg_level != IPPROTO_IP)
 780                                 continue;
 781
 782                         switch (cm->cmsg_type) {
 783                         case IP_SENDSRCADDR:
 784                                 if (cm->cmsg_len !=
 785                                     CMSG_LEN(sizeof(struct in_addr))) {
 786                                         error = EINVAL;
 787                                         break;
 788                                 }
 789                                 bzero(&src, sizeof(src));
 790                                 src.sin_family = AF_INET;
 791                                 src.sin_len = sizeof(src);
 792                                 src.sin_port = inp->inp_lport;
 793                                 src.sin_addr = *(struct in_addr *)CMSG_DATA(cm);
 794                                 break;
 795                         default:
 796                                 error = ENOPROTOOPT;
 797                                 break;
 798                         }
 799                         if (error)
 800                                 break;
 801                 }
 802                 m_freem(control);
 803         }
 804         if (error) {
 805                 m_freem(m);
 806                 return error;
 807         }
 808
 809         if (src.sin_addr.s_addr != INADDR_ANY ||
 810             addr != NULL) {
 811                 INP_INFO_WLOCK(&udbinfo);
 812                 unlock_udbinfo = 1;
 813         } else
 814                 unlock_udbinfo = 0;
 815         INP_LOCK(inp);
 816
 817 #ifdef MAC
 818         mac_create_mbuf_from_inpcb(inp, m);
 819 #endif
 820
 821         laddr = inp->inp_laddr;
 822         lport = inp->inp_lport;
 823         if (src.sin_addr.s_addr != INADDR_ANY) {
 824                 if (lport == 0) {
 825                         error = EINVAL;
 826                         goto release;
 827                 }
 828                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
 829                     &laddr.s_addr, &lport, td->td_ucred);
 830                 if (error)
 831                         goto release;
 832         }
 833
 834         if (addr) {
 835                 sin = (struct sockaddr_in *)addr;
 836                 if (jailed(td->td_ucred))
 837                         prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr);
 838                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 839                         error = EISCONN;
 840                         goto release;
 841                 }
 842                 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr, &lport,
 843                     &faddr.s_addr, &fport, NULL, td->td_ucred);
 844                 if (error)
 845                         goto release;
 846
 847                 /* Commit the local port if newly assigned. */
 848                 if (inp->inp_laddr.s_addr == INADDR_ANY &&
 849                     inp->inp_lport == 0) {
 850                         /*
 851                          * Remember addr if jailed, to prevent rebinding.
 852                          */
 853                         if (jailed(td->td_ucred))
 854                                 inp->inp_laddr = laddr;
 855                         inp->inp_lport = lport;
 856                         if (in_pcbinshash(inp) != 0) {
 857                                 inp->inp_lport = 0;
 858                                 error = EAGAIN;
 859                                 goto release;
 860                         }
 861                         inp->inp_flags |= INP_ANONPORT;
 862                 }
 863         } else {
 864                 faddr = inp->inp_faddr;
 865                 fport = inp->inp_fport;
 866                 if (faddr.s_addr == INADDR_ANY) {
 867                         error = ENOTCONN;
 868                         goto release;
 869                 }
 870         }
 871
 872         /*
 873          * Calculate data length and get a mbuf for UDP, IP, and possible
 874          * link-layer headers.  Immediate slide the data pointer back forward
 875          * since we won't use that space at this layer.
 876          */
 877         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
 878         if (m == NULL) {
 879                 error = ENOBUFS;
 880                 goto release;
 881         }
 882         m->m_data += max_linkhdr;
 883         m->m_len -= max_linkhdr;
 884         m->m_pkthdr.len -= max_linkhdr;
 885
 886         /*
 887          * Fill in mbuf with extended UDP header
 888          * and addresses and length put into network format.
 889          */
 890         ui = mtod(m, struct udpiphdr *);
 891         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
 892         ui->ui_pr = IPPROTO_UDP;
 893         ui->ui_src = laddr;
 894         ui->ui_dst = faddr;
 895         ui->ui_sport = lport;
 896         ui->ui_dport = fport;
 897         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
 898
 899         /*
 900          * Set the Don't Fragment bit in the IP header.
 901          */
 902         if (inp->inp_flags & INP_DONTFRAG) {
 903                 struct ip *ip;
 904                 ip = (struct ip *)&ui->ui_i;
 905                 ip->ip_off |= IP_DF;
 906         }
 907
 908         ipflags = 0;
 909         if (inp->inp_socket->so_options & SO_DONTROUTE)
 910                 ipflags |= IP_ROUTETOIF;
 911         if (inp->inp_socket->so_options & SO_BROADCAST)
 912                 ipflags |= IP_ALLOWBROADCAST;
 913         if (inp->inp_flags & INP_ONESBCAST)
 914                 ipflags |= IP_SENDONES;
 915
 916         /*
 917          * Set up checksum and output datagram.
 918          */
 919         if (udpcksum) {
 920                 if (inp->inp_flags & INP_ONESBCAST)
 921                         faddr.s_addr = INADDR_BROADCAST;
 922                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
 923                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
 924                 m->m_pkthdr.csum_flags = CSUM_UDP;
 925                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 926         } else {
 927                 ui->ui_sum = 0;
 928         }
 929         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
 930         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
 931         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
 932         udpstat.udps_opackets++;
 933
 934         if (unlock_udbinfo)
 935                 INP_INFO_WUNLOCK(&udbinfo);
 936         error = ip_output(m, inp->inp_options, NULL, ipflags,
 937             inp->inp_moptions, inp);
 938         INP_UNLOCK(inp);
 939         return (error);
 940
 941 release:
 942         INP_UNLOCK(inp);
 943         if (unlock_udbinfo)
 944                 INP_INFO_WUNLOCK(&udbinfo);
 945         m_freem(m);
 946         return (error);
 947 }
 948
 949 u_long  udp_sendspace = 9216;           /* really max datagram size */
 950                                         /* 40 1K datagrams */
 951 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 952     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 953
 954 u_long  udp_recvspace = 40 * (1024 +
 955 #ifdef INET6
 956                                       sizeof(struct sockaddr_in6)
 957 #else
 958                                       sizeof(struct sockaddr_in)
 959 #endif
 960                                       );
 961 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 962     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 963
 964 static void
 965 udp_abort(struct socket *so)
 966 {
 967         struct inpcb *inp;
 968
 969         inp = sotoinpcb(so);
 970         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
 971         INP_INFO_WLOCK(&udbinfo);
 972         INP_LOCK(inp);
 973         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 974                 in_pcbdisconnect(inp);
 975                 inp->inp_laddr.s_addr = INADDR_ANY;
 976                 soisdisconnected(so);
 977         }
 978         INP_UNLOCK(inp);
 979         INP_INFO_WUNLOCK(&udbinfo);
 980 }
 981
 982 static int
 983 udp_attach(struct socket *so, int proto, struct thread *td)
 984 {
 985         struct inpcb *inp;
 986         int error;
 987
 988         inp = sotoinpcb(so);
 989         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
 990         error = soreserve(so, udp_sendspace, udp_recvspace);
 991         if (error)
 992                 return error;
 993         INP_INFO_WLOCK(&udbinfo);
 994         error = in_pcballoc(so, &udbinfo);
 995         if (error) {
 996                 INP_INFO_WUNLOCK(&udbinfo);
 997                 return error;
 998         }
 999
1000         inp = (struct inpcb *)so->so_pcb;
1001         INP_INFO_WUNLOCK(&udbinfo);
1002         inp->inp_vflag |= INP_IPV4;
1003         inp->inp_ip_ttl = ip_defttl;
1004         INP_UNLOCK(inp);
1005         return 0;
1006 }
1007
1008 static int
1009 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1010 {
1011         struct inpcb *inp;
1012         int error;
1013
1014         inp = sotoinpcb(so);
1015         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1016         INP_INFO_WLOCK(&udbinfo);
1017         INP_LOCK(inp);
1018         error = in_pcbbind(inp, nam, td->td_ucred);
1019         INP_UNLOCK(inp);
1020         INP_INFO_WUNLOCK(&udbinfo);
1021         return error;
1022 }
1023
1024 static void
1025 udp_close(struct socket *so)
1026 {
1027         struct inpcb *inp;
1028
1029         inp = sotoinpcb(so);
1030         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1031         INP_INFO_WLOCK(&udbinfo);
1032         INP_LOCK(inp);
1033         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1034                 in_pcbdisconnect(inp);
1035                 inp->inp_laddr.s_addr = INADDR_ANY;
1036                 soisdisconnected(so);
1037         }
1038         INP_UNLOCK(inp);
1039         INP_INFO_WUNLOCK(&udbinfo);
1040 }
1041
1042 static int
1043 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1044 {
1045         struct inpcb *inp;
1046         int error;
1047         struct sockaddr_in *sin;
1048
1049         inp = sotoinpcb(so);
1050         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1051         INP_INFO_WLOCK(&udbinfo);
1052         INP_LOCK(inp);
1053         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1054                 INP_UNLOCK(inp);
1055                 INP_INFO_WUNLOCK(&udbinfo);
1056                 return EISCONN;
1057         }
1058         sin = (struct sockaddr_in *)nam;
1059         if (jailed(td->td_ucred))
1060                 prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr);
1061         error = in_pcbconnect(inp, nam, td->td_ucred);
1062         if (error == 0)
1063                 soisconnected(so);
1064         INP_UNLOCK(inp);
1065         INP_INFO_WUNLOCK(&udbinfo);
1066         return error;
1067 }
1068
1069 static void
1070 udp_detach(struct socket *so)
1071 {
1072         struct inpcb *inp;
1073
1074         inp = sotoinpcb(so);
1075         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1076         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1077             ("udp_detach: not disconnected"));
1078         INP_INFO_WLOCK(&udbinfo);
1079         INP_LOCK(inp);
1080         in_pcbdetach(inp);
1081         in_pcbfree(inp);
1082         INP_INFO_WUNLOCK(&udbinfo);
1083 }
1084
1085 static int
1086 udp_disconnect(struct socket *so)
1087 {
1088         struct inpcb *inp;
1089
1090         inp = sotoinpcb(so);
1091         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1092         INP_INFO_WLOCK(&udbinfo);
1093         INP_LOCK(inp);
1094         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1095                 INP_INFO_WUNLOCK(&udbinfo);
1096                 INP_UNLOCK(inp);
1097                 return ENOTCONN;
1098         }
1099
1100         in_pcbdisconnect(inp);
1101         inp->inp_laddr.s_addr = INADDR_ANY;
1102         SOCK_LOCK(so);
1103         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1104         SOCK_UNLOCK(so);
1105         INP_UNLOCK(inp);
1106         INP_INFO_WUNLOCK(&udbinfo);
1107         return 0;
1108 }
1109
1110 static int
1111 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1112             struct mbuf *control, struct thread *td)
1113 {
1114         struct inpcb *inp;
1115
1116         inp = sotoinpcb(so);
1117         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1118         return udp_output(inp, m, addr, control, td);
1119 }
1120
1121 int
1122 udp_shutdown(struct socket *so)
1123 {
1124         struct inpcb *inp;
1125
1126         inp = sotoinpcb(so);
1127         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1128         INP_LOCK(inp);
1129         socantsendmore(so);
1130         INP_UNLOCK(inp);
1131         return 0;
1132 }
1133
1134 /*
1135  * This is the wrapper function for in_setsockaddr.  We just pass down
1136  * the pcbinfo for in_setsockaddr to lock.  We don't want to do the locking
1137  * here because in_setsockaddr will call malloc and might block.
1138  */
1139 static int
1140 udp_sockaddr(struct socket *so, struct sockaddr **nam)
1141 {
1142         return (in_setsockaddr(so, nam, &udbinfo));
1143 }
1144
1145 /*
1146  * This is the wrapper function for in_setpeeraddr.  We just pass down
1147  * the pcbinfo for in_setpeeraddr to lock.
1148  */
1149 static int
1150 udp_peeraddr(struct socket *so, struct sockaddr **nam)
1151 {
1152         return (in_setpeeraddr(so, nam, &udbinfo));
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 =         udp_peeraddr,
1164         .pru_send =             udp_send,
1165         .pru_sosend =           sosend_dgram,
1166         .pru_shutdown =         udp_shutdown,
1167         .pru_sockaddr =         udp_sockaddr,
1168         .pru_sosetlabel =       in_pcbsosetlabel,
1169         .pru_close =            udp_close,
1170 };