sys/netinet/udp_usrreq.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
   3  *      The Regents of the University of California.
   4  * Copyright (c) 2008 Robert N. M. Watson
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 4. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include "opt_ipfw.h"
  38 #include "opt_inet6.h"
  39 #include "opt_ipsec.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 #include <netipsec/esp.h>
  86 #endif
  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 VNET_DEFINE(int, udp_blackhole);
  98
  99 /*
 100  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
 101  * removes the only data integrity mechanism for packets and malformed
 102  * packets that would otherwise be discarded due to bad checksums, and may
 103  * cause problems (especially for NFS data blocks).
 104  */
 105 static int      udp_cksum = 1;
 106 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum,
 107     0, "compute udp checksum");
 108
 109 int     udp_log_in_vain = 0;
 110 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 111     &udp_log_in_vain, 0, "Log all incoming UDP packets");
 112
 113 SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 114     &VNET_NAME(udp_blackhole), 0,
 115     "Do not send port unreachables for refused connects");
 116
 117 u_long  udp_sendspace = 9216;           /* really max datagram size */
 118                                         /* 40 1K datagrams */
 119 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 120     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 121
 122 u_long  udp_recvspace = 40 * (1024 +
 123 #ifdef INET6
 124                                       sizeof(struct sockaddr_in6)
 125 #else
 126                                       sizeof(struct sockaddr_in)
 127 #endif
 128                                       );
 129
 130 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 131     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 132
 133 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
 134 VNET_DEFINE(struct inpcbinfo, udbinfo);
 135 static VNET_DEFINE(uma_zone_t, udpcb_zone);
 136 VNET_DEFINE(struct udpstat, udpstat);           /* from udp_var.h */
 137
 138 #define V_udpcb_zone                    VNET(udpcb_zone)
 139
 140 #ifndef UDBHASHSIZE
 141 #define UDBHASHSIZE     128
 142 #endif
 143
 144 SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
 145     &VNET_NAME(udpstat), udpstat,
 146     "UDP statistics (struct udpstat, netinet/udp_var.h)");
 147
 148 static void     udp_detach(struct socket *so);
 149 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 150                     struct mbuf *, struct thread *);
 151 #ifdef IPSEC
 152 #ifdef IPSEC_NAT_T
 153 #define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
 154 #ifdef INET
 155 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
 156 #endif
 157 #endif /* IPSEC_NAT_T */
 158 #endif /* IPSEC */
 159
 160 static void
 161 udp_zone_change(void *tag)
 162 {
 163
 164         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 165         uma_zone_set_max(V_udpcb_zone, maxsockets);
 166 }
 167
 168 static int
 169 udp_inpcb_init(void *mem, int size, int flags)
 170 {
 171         struct inpcb *inp;
 172
 173         inp = mem;
 174         INP_LOCK_INIT(inp, "inp", "udpinp");
 175         return (0);
 176 }
 177
 178 void
 179 udp_init(void)
 180 {
 181
 182         V_udp_blackhole = 0;
 183
 184         INP_INFO_LOCK_INIT(&V_udbinfo, "udp");
 185         LIST_INIT(&V_udb);
 186 #ifdef VIMAGE
 187         V_udbinfo.ipi_vnet = curvnet;
 188 #endif
 189         V_udbinfo.ipi_listhead = &V_udb;
 190         V_udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
 191             &V_udbinfo.ipi_hashmask);
 192         V_udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
 193             &V_udbinfo.ipi_porthashmask);
 194         V_udbinfo.ipi_zone = uma_zcreate("udp_inpcb", sizeof(struct inpcb),
 195             NULL, NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 196         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 197
 198         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
 199             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 200         uma_zone_set_max(V_udpcb_zone, maxsockets);
 201
 202         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 203             EVENTHANDLER_PRI_ANY);
 204 }
 205
 206 /*
 207  * Kernel module interface for updating udpstat.  The argument is an index
 208  * into udpstat treated as an array of u_long.  While this encodes the
 209  * general layout of udpstat into the caller, it doesn't encode its location,
 210  * so that future changes to add, for example, per-CPU stats support won't
 211  * cause binary compatibility problems for kernel modules.
 212  */
 213 void
 214 kmod_udpstat_inc(int statnum)
 215 {
 216
 217         (*((u_long *)&V_udpstat + statnum))++;
 218 }
 219
 220 int
 221 udp_newudpcb(struct inpcb *inp)
 222 {
 223         struct udpcb *up;
 224
 225         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
 226         if (up == NULL)
 227                 return (ENOBUFS);
 228         inp->inp_ppcb = up;
 229         return (0);
 230 }
 231
 232 void
 233 udp_discardcb(struct udpcb *up)
 234 {
 235
 236         uma_zfree(V_udpcb_zone, up);
 237 }
 238
 239 #ifdef VIMAGE
 240 void
 241 udp_destroy(void)
 242 {
 243
 244         hashdestroy(V_udbinfo.ipi_hashbase, M_PCB,
 245             V_udbinfo.ipi_hashmask);
 246         hashdestroy(V_udbinfo.ipi_porthashbase, M_PCB,
 247             V_udbinfo.ipi_porthashmask);
 248         INP_INFO_LOCK_DESTROY(&V_udbinfo);
 249 }
 250 #endif
 251
 252 /*
 253  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 254  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 255  * contains the source address.  If the socket ends up being an IPv6 socket,
 256  * udp_append() will convert to a sockaddr_in6 before passing the address
 257  * into the socket code.
 258  */
 259 static void
 260 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 261     struct sockaddr_in *udp_in)
 262 {
 263         struct sockaddr *append_sa;
 264         struct socket *so;
 265         struct mbuf *opts = 0;
 266 #ifdef INET6
 267         struct sockaddr_in6 udp_in6;
 268 #endif
 269 #ifdef IPSEC
 270 #ifdef IPSEC_NAT_T
 271 #ifdef INET
 272         struct udpcb *up;
 273 #endif
 274 #endif
 275 #endif
 276
 277         INP_RLOCK_ASSERT(inp);
 278
 279 #ifdef IPSEC
 280         /* Check AH/ESP integrity. */
 281         if (ipsec4_in_reject(n, inp)) {
 282                 m_freem(n);
 283                 V_ipsec4stat.in_polvio++;
 284                 return;
 285         }
 286 #ifdef IPSEC_NAT_T
 287 #ifdef INET
 288         up = intoudpcb(inp);
 289         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
 290         if (up->u_flags & UF_ESPINUDP_ALL) {    /* IPSec UDP encaps. */
 291                 n = udp4_espdecap(inp, n, off);
 292                 if (n == NULL)                          /* Consumed. */
 293                         return;
 294         }
 295 #endif /* INET */
 296 #endif /* IPSEC_NAT_T */
 297 #endif /* IPSEC */
 298 #ifdef MAC
 299         if (mac_inpcb_check_deliver(inp, n) != 0) {
 300                 m_freem(n);
 301                 return;
 302         }
 303 #endif
 304         if (inp->inp_flags & INP_CONTROLOPTS ||
 305             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 306 #ifdef INET6
 307                 if (inp->inp_vflag & INP_IPV6)
 308                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
 309                 else
 310 #endif
 311                         ip_savecontrol(inp, &opts, ip, n);
 312         }
 313 #ifdef INET6
 314         if (inp->inp_vflag & INP_IPV6) {
 315                 bzero(&udp_in6, sizeof(udp_in6));
 316                 udp_in6.sin6_len = sizeof(udp_in6);
 317                 udp_in6.sin6_family = AF_INET6;
 318                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 319                 append_sa = (struct sockaddr *)&udp_in6;
 320         } else
 321 #endif
 322                 append_sa = (struct sockaddr *)udp_in;
 323         m_adj(n, off);
 324
 325         so = inp->inp_socket;
 326         SOCKBUF_LOCK(&so->so_rcv);
 327         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 328                 SOCKBUF_UNLOCK(&so->so_rcv);
 329                 m_freem(n);
 330                 if (opts)
 331                         m_freem(opts);
 332                 UDPSTAT_INC(udps_fullsock);
 333         } else
 334                 sorwakeup_locked(so);
 335 }
 336
 337 void
 338 udp_input(struct mbuf *m, int off)
 339 {
 340         int iphlen = off;
 341         struct ip *ip;
 342         struct udphdr *uh;
 343         struct ifnet *ifp;
 344         struct inpcb *inp;
 345         struct udpcb *up;
 346         int len;
 347         struct ip save_ip;
 348         struct sockaddr_in udp_in;
 349 #ifdef IPFIREWALL_FORWARD
 350         struct m_tag *fwd_tag;
 351 #endif
 352
 353         ifp = m->m_pkthdr.rcvif;
 354         UDPSTAT_INC(udps_ipackets);
 355
 356         /*
 357          * Strip IP options, if any; should skip this, make available to
 358          * user, and use on returned packets, but we don't yet have a way to
 359          * check the checksum with options still present.
 360          */
 361         if (iphlen > sizeof (struct ip)) {
 362                 ip_stripoptions(m, (struct mbuf *)0);
 363                 iphlen = sizeof(struct ip);
 364         }
 365
 366         /*
 367          * Get IP and UDP header together in first mbuf.
 368          */
 369         ip = mtod(m, struct ip *);
 370         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 371                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 372                         UDPSTAT_INC(udps_hdrops);
 373                         return;
 374                 }
 375                 ip = mtod(m, struct ip *);
 376         }
 377         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 378
 379         /*
 380          * Destination port of 0 is illegal, based on RFC768.
 381          */
 382         if (uh->uh_dport == 0)
 383                 goto badunlocked;
 384
 385         /*
 386          * Construct sockaddr format source address.  Stuff source address
 387          * and datagram in user buffer.
 388          */
 389         bzero(&udp_in, sizeof(udp_in));
 390         udp_in.sin_len = sizeof(udp_in);
 391         udp_in.sin_family = AF_INET;
 392         udp_in.sin_port = uh->uh_sport;
 393         udp_in.sin_addr = ip->ip_src;
 394
 395         /*
 396          * Make mbuf data length reflect UDP length.  If not enough data to
 397          * reflect UDP length, drop.
 398          */
 399         len = ntohs((u_short)uh->uh_ulen);
 400         if (ip->ip_len != len) {
 401                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 402                         UDPSTAT_INC(udps_badlen);
 403                         goto badunlocked;
 404                 }
 405                 m_adj(m, len - ip->ip_len);
 406                 /* ip->ip_len = len; */
 407         }
 408
 409         /*
 410          * Save a copy of the IP header in case we want restore it for
 411          * sending an ICMP error message in response.
 412          */
 413         if (!V_udp_blackhole)
 414                 save_ip = *ip;
 415         else
 416                 memset(&save_ip, 0, sizeof(save_ip));
 417
 418         /*
 419          * Checksum extended UDP header and data.
 420          */
 421         if (uh->uh_sum) {
 422                 u_short uh_sum;
 423
 424                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 425                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 426                                 uh_sum = m->m_pkthdr.csum_data;
 427                         else
 428                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 429                                     ip->ip_dst.s_addr, htonl((u_short)len +
 430                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 431                         uh_sum ^= 0xffff;
 432                 } else {
 433                         char b[9];
 434
 435                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 436                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 437                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 438                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 439                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 440                 }
 441                 if (uh_sum) {
 442                         UDPSTAT_INC(udps_badsum);
 443                         m_freem(m);
 444                         return;
 445                 }
 446         } else
 447                 UDPSTAT_INC(udps_nosum);
 448
 449 #ifdef IPFIREWALL_FORWARD
 450         /*
 451          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 452          */
 453         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 454         if (fwd_tag != NULL) {
 455                 struct sockaddr_in *next_hop;
 456
 457                 /*
 458                  * Do the hack.
 459                  */
 460                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 461                 ip->ip_dst = next_hop->sin_addr;
 462                 uh->uh_dport = ntohs(next_hop->sin_port);
 463
 464                 /*
 465                  * Remove the tag from the packet.  We don't need it anymore.
 466                  */
 467                 m_tag_delete(m, fwd_tag);
 468         }
 469 #endif
 470
 471         INP_INFO_RLOCK(&V_udbinfo);
 472         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 473             in_broadcast(ip->ip_dst, ifp)) {
 474                 struct inpcb *last;
 475                 struct ip_moptions *imo;
 476
 477                 last = NULL;
 478                 LIST_FOREACH(inp, &V_udb, inp_list) {
 479                         if (inp->inp_lport != uh->uh_dport)
 480                                 continue;
 481 #ifdef INET6
 482                         if ((inp->inp_vflag & INP_IPV4) == 0)
 483                                 continue;
 484 #endif
 485                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 486                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 487                                 continue;
 488                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 489                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 490                                 continue;
 491                         if (inp->inp_fport != 0 &&
 492                             inp->inp_fport != uh->uh_sport)
 493                                 continue;
 494
 495                         INP_RLOCK(inp);
 496
 497                         /*
 498                          * Handle socket delivery policy for any-source
 499                          * and source-specific multicast. [RFC3678]
 500                          */
 501                         imo = inp->inp_moptions;
 502                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
 503                             imo != NULL) {
 504                                 struct sockaddr_in       group;
 505                                 int                      blocked;
 506
 507                                 bzero(&group, sizeof(struct sockaddr_in));
 508                                 group.sin_len = sizeof(struct sockaddr_in);
 509                                 group.sin_family = AF_INET;
 510                                 group.sin_addr = ip->ip_dst;
 511
 512                                 blocked = imo_multi_filter(imo, ifp,
 513                                         (struct sockaddr *)&group,
 514                                         (struct sockaddr *)&udp_in);
 515                                 if (blocked != MCAST_PASS) {
 516                                         if (blocked == MCAST_NOTGMEMBER)
 517                                                 IPSTAT_INC(ips_notmember);
 518                                         if (blocked == MCAST_NOTSMEMBER ||
 519                                             blocked == MCAST_MUTED)
 520                                                 UDPSTAT_INC(udps_filtermcast);
 521                                         INP_RUNLOCK(inp);
 522                                         continue;
 523                                 }
 524                         }
 525                         if (last != NULL) {
 526                                 struct mbuf *n;
 527
 528                                 n = m_copy(m, 0, M_COPYALL);
 529                                 up = intoudpcb(last);
 530                                 if (up->u_tun_func == NULL) {
 531                                         if (n != NULL)
 532                                                 udp_append(last,
 533                                                     ip, n,
 534                                                     iphlen +
 535                                                     sizeof(struct udphdr),
 536                                                     &udp_in);
 537                                 } else {
 538                                         /*
 539                                          * Engage the tunneling protocol we
 540                                          * will have to leave the info_lock
 541                                          * up, since we are hunting through
 542                                          * multiple UDP's.
 543                                          */
 544
 545                                         (*up->u_tun_func)(n, iphlen, last);
 546                                 }
 547                                 INP_RUNLOCK(last);
 548                         }
 549                         last = inp;
 550                         /*
 551                          * Don't look for additional matches if this one does
 552                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 553                          * socket options set.  This heuristic avoids
 554                          * searching through all pcbs in the common case of a
 555                          * non-shared port.  It assumes that an application
 556                          * will never clear these options after setting them.
 557                          */
 558                         if ((last->inp_socket->so_options &
 559                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 560                                 break;
 561                 }
 562
 563                 if (last == NULL) {
 564                         /*
 565                          * No matching pcb found; discard datagram.  (No need
 566                          * to send an ICMP Port Unreachable for a broadcast
 567                          * or multicast datgram.)
 568                          */
 569                         UDPSTAT_INC(udps_noportbcast);
 570                         goto badheadlocked;
 571                 }
 572                 up = intoudpcb(last);
 573                 if (up->u_tun_func == NULL) {
 574                         udp_append(last, ip, m, iphlen + sizeof(struct udphdr),
 575                             &udp_in);
 576                 } else {
 577                         /*
 578                          * Engage the tunneling protocol.
 579                          */
 580                         (*up->u_tun_func)(m, iphlen, last);
 581                 }
 582                 INP_RUNLOCK(last);
 583                 INP_INFO_RUNLOCK(&V_udbinfo);
 584                 return;
 585         }
 586
 587         /*
 588          * Locate pcb for datagram.
 589          */
 590         inp = in_pcblookup_hash(&V_udbinfo, ip->ip_src, uh->uh_sport,
 591             ip->ip_dst, uh->uh_dport, 1, ifp);
 592         if (inp == NULL) {
 593                 if (udp_log_in_vain) {
 594                         char buf[4*sizeof "123"];
 595
 596                         strcpy(buf, inet_ntoa(ip->ip_dst));
 597                         log(LOG_INFO,
 598                             "Connection attempt to UDP %s:%d from %s:%d\n",
 599                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 600                             ntohs(uh->uh_sport));
 601                 }
 602                 UDPSTAT_INC(udps_noport);
 603                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 604                         UDPSTAT_INC(udps_noportbcast);
 605                         goto badheadlocked;
 606                 }
 607                 if (V_udp_blackhole)
 608                         goto badheadlocked;
 609                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 610                         goto badheadlocked;
 611                 *ip = save_ip;
 612                 ip->ip_len += iphlen;
 613                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 614                 INP_INFO_RUNLOCK(&V_udbinfo);
 615                 return;
 616         }
 617
 618         /*
 619          * Check the minimum TTL for socket.
 620          */
 621         INP_RLOCK(inp);
 622         INP_INFO_RUNLOCK(&V_udbinfo);
 623         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 624                 INP_RUNLOCK(inp);
 625                 goto badunlocked;
 626         }
 627         up = intoudpcb(inp);
 628         if (up->u_tun_func == NULL) {
 629                 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in);
 630         } else {
 631                 /*
 632                  * Engage the tunneling protocol.
 633                  */
 634
 635                 (*up->u_tun_func)(m, iphlen, inp);
 636         }
 637         INP_RUNLOCK(inp);
 638         return;
 639
 640 badheadlocked:
 641         if (inp)
 642                 INP_RUNLOCK(inp);
 643         INP_INFO_RUNLOCK(&V_udbinfo);
 644 badunlocked:
 645         m_freem(m);
 646 }
 647
 648 /*
 649  * Notify a udp user of an asynchronous error; just wake up so that they can
 650  * collect error status.
 651  */
 652 struct inpcb *
 653 udp_notify(struct inpcb *inp, int errno)
 654 {
 655
 656         /*
 657          * While udp_ctlinput() always calls udp_notify() with a read lock
 658          * when invoking it directly, in_pcbnotifyall() currently uses write
 659          * locks due to sharing code with TCP.  For now, accept either a read
 660          * or a write lock, but a read lock is sufficient.
 661          */
 662         INP_LOCK_ASSERT(inp);
 663
 664         inp->inp_socket->so_error = errno;
 665         sorwakeup(inp->inp_socket);
 666         sowwakeup(inp->inp_socket);
 667         return (inp);
 668 }
 669
 670 void
 671 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 672 {
 673         struct ip *ip = vip;
 674         struct udphdr *uh;
 675         struct in_addr faddr;
 676         struct inpcb *inp;
 677
 678         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 679         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 680                 return;
 681
 682         /*
 683          * Redirects don't need to be handled up here.
 684          */
 685         if (PRC_IS_REDIRECT(cmd))
 686                 return;
 687
 688         /*
 689          * Hostdead is ugly because it goes linearly through all PCBs.
 690          *
 691          * XXX: We never get this from ICMP, otherwise it makes an excellent
 692          * DoS attack on machines with many connections.
 693          */
 694         if (cmd == PRC_HOSTDEAD)
 695                 ip = NULL;
 696         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 697                 return;
 698         if (ip != NULL) {
 699                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 700                 INP_INFO_RLOCK(&V_udbinfo);
 701                 inp = in_pcblookup_hash(&V_udbinfo, faddr, uh->uh_dport,
 702                     ip->ip_src, uh->uh_sport, 0, NULL);
 703                 if (inp != NULL) {
 704                         INP_RLOCK(inp);
 705                         if (inp->inp_socket != NULL) {
 706                                 udp_notify(inp, inetctlerrmap[cmd]);
 707                         }
 708                         INP_RUNLOCK(inp);
 709                 }
 710                 INP_INFO_RUNLOCK(&V_udbinfo);
 711         } else
 712                 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
 713                     udp_notify);
 714 }
 715
 716 static int
 717 udp_pcblist(SYSCTL_HANDLER_ARGS)
 718 {
 719         int error, i, n;
 720         struct inpcb *inp, **inp_list;
 721         inp_gen_t gencnt;
 722         struct xinpgen xig;
 723
 724         /*
 725          * The process of preparing the PCB list is too time-consuming and
 726          * resource-intensive to repeat twice on every request.
 727          */
 728         if (req->oldptr == 0) {
 729                 n = V_udbinfo.ipi_count;
 730                 req->oldidx = 2 * (sizeof xig)
 731                         + (n + n/8) * sizeof(struct xinpcb);
 732                 return (0);
 733         }
 734
 735         if (req->newptr != 0)
 736                 return (EPERM);
 737
 738         /*
 739          * OK, now we're committed to doing something.
 740          */
 741         INP_INFO_RLOCK(&V_udbinfo);
 742         gencnt = V_udbinfo.ipi_gencnt;
 743         n = V_udbinfo.ipi_count;
 744         INP_INFO_RUNLOCK(&V_udbinfo);
 745
 746         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 747                 + n * sizeof(struct xinpcb));
 748         if (error != 0)
 749                 return (error);
 750
 751         xig.xig_len = sizeof xig;
 752         xig.xig_count = n;
 753         xig.xig_gen = gencnt;
 754         xig.xig_sogen = so_gencnt;
 755         error = SYSCTL_OUT(req, &xig, sizeof xig);
 756         if (error)
 757                 return (error);
 758
 759         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 760         if (inp_list == 0)
 761                 return (ENOMEM);
 762
 763         INP_INFO_RLOCK(&V_udbinfo);
 764         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
 765              inp = LIST_NEXT(inp, inp_list)) {
 766                 INP_RLOCK(inp);
 767                 if (inp->inp_gencnt <= gencnt &&
 768                     cr_canseeinpcb(req->td->td_ucred, inp) == 0)
 769                         inp_list[i++] = inp;
 770                 INP_RUNLOCK(inp);
 771         }
 772         INP_INFO_RUNLOCK(&V_udbinfo);
 773         n = i;
 774
 775         error = 0;
 776         for (i = 0; i < n; i++) {
 777                 inp = inp_list[i];
 778                 INP_RLOCK(inp);
 779                 if (inp->inp_gencnt <= gencnt) {
 780                         struct xinpcb xi;
 781                         bzero(&xi, sizeof(xi));
 782                         xi.xi_len = sizeof xi;
 783                         /* XXX should avoid extra copy */
 784                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 785                         if (inp->inp_socket)
 786                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 787                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 788                         INP_RUNLOCK(inp);
 789                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 790                 } else
 791                         INP_RUNLOCK(inp);
 792         }
 793         if (!error) {
 794                 /*
 795                  * Give the user an updated idea of our state.  If the
 796                  * generation differs from what we told her before, she knows
 797                  * that something happened while we were processing this
 798                  * request, and it might be necessary to retry.
 799                  */
 800                 INP_INFO_RLOCK(&V_udbinfo);
 801                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 802                 xig.xig_sogen = so_gencnt;
 803                 xig.xig_count = V_udbinfo.ipi_count;
 804                 INP_INFO_RUNLOCK(&V_udbinfo);
 805                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 806         }
 807         free(inp_list, M_TEMP);
 808         return (error);
 809 }
 810
 811 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
 812     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 813
 814 static int
 815 udp_getcred(SYSCTL_HANDLER_ARGS)
 816 {
 817         struct xucred xuc;
 818         struct sockaddr_in addrs[2];
 819         struct inpcb *inp;
 820         int error;
 821
 822         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 823         if (error)
 824                 return (error);
 825         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 826         if (error)
 827                 return (error);
 828         INP_INFO_RLOCK(&V_udbinfo);
 829         inp = in_pcblookup_hash(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 830                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
 831         if (inp != NULL) {
 832                 INP_RLOCK(inp);
 833                 INP_INFO_RUNLOCK(&V_udbinfo);
 834                 if (inp->inp_socket == NULL)
 835                         error = ENOENT;
 836                 if (error == 0)
 837                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 838                 if (error == 0)
 839                         cru2x(inp->inp_cred, &xuc);
 840                 INP_RUNLOCK(inp);
 841         } else {
 842                 INP_INFO_RUNLOCK(&V_udbinfo);
 843                 error = ENOENT;
 844         }
 845         if (error == 0)
 846                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 847         return (error);
 848 }
 849
 850 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 851     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 852     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 853
 854 int
 855 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 856 {
 857         int error = 0, optval;
 858         struct inpcb *inp;
 859 #ifdef IPSEC_NAT_T
 860         struct udpcb *up;
 861 #endif
 862
 863         inp = sotoinpcb(so);
 864         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 865         INP_WLOCK(inp);
 866         if (sopt->sopt_level != IPPROTO_UDP) {
 867 #ifdef INET6
 868                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 869                         INP_WUNLOCK(inp);
 870                         error = ip6_ctloutput(so, sopt);
 871                 } else {
 872 #endif
 873                         INP_WUNLOCK(inp);
 874                         error = ip_ctloutput(so, sopt);
 875 #ifdef INET6
 876                 }
 877 #endif
 878                 return (error);
 879         }
 880
 881         switch (sopt->sopt_dir) {
 882         case SOPT_SET:
 883                 switch (sopt->sopt_name) {
 884                 case UDP_ENCAP:
 885                         INP_WUNLOCK(inp);
 886                         error = sooptcopyin(sopt, &optval, sizeof optval,
 887                                             sizeof optval);
 888                         if (error)
 889                                 break;
 890                         inp = sotoinpcb(so);
 891                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 892                         INP_WLOCK(inp);
 893 #ifdef IPSEC_NAT_T
 894                         up = intoudpcb(inp);
 895                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 896 #endif
 897                         switch (optval) {
 898                         case 0:
 899                                 /* Clear all UDP encap. */
 900 #ifdef IPSEC_NAT_T
 901                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 902 #endif
 903                                 break;
 904 #ifdef IPSEC_NAT_T
 905                         case UDP_ENCAP_ESPINUDP:
 906                         case UDP_ENCAP_ESPINUDP_NON_IKE:
 907                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 908                                 if (optval == UDP_ENCAP_ESPINUDP)
 909                                         up->u_flags |= UF_ESPINUDP;
 910                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
 911                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
 912                                 break;
 913 #endif
 914                         default:
 915                                 error = EINVAL;
 916                                 break;
 917                         }
 918                         INP_WUNLOCK(inp);
 919                         break;
 920                 default:
 921                         INP_WUNLOCK(inp);
 922                         error = ENOPROTOOPT;
 923                         break;
 924                 }
 925                 break;
 926         case SOPT_GET:
 927                 switch (sopt->sopt_name) {
 928 #ifdef IPSEC_NAT_T
 929                 case UDP_ENCAP:
 930                         up = intoudpcb(inp);
 931                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 932                         optval = up->u_flags & UF_ESPINUDP_ALL;
 933                         INP_WUNLOCK(inp);
 934                         error = sooptcopyout(sopt, &optval, sizeof optval);
 935                         break;
 936 #endif
 937                 default:
 938                         INP_WUNLOCK(inp);
 939                         error = ENOPROTOOPT;
 940                         break;
 941                 }
 942                 break;
 943         }
 944         return (error);
 945 }
 946
 947 static int
 948 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
 949     struct mbuf *control, struct thread *td)
 950 {
 951         struct udpiphdr *ui;
 952         int len = m->m_pkthdr.len;
 953         struct in_addr faddr, laddr;
 954         struct cmsghdr *cm;
 955         struct sockaddr_in *sin, src;
 956         int error = 0;
 957         int ipflags;
 958         u_short fport, lport;
 959         int unlock_udbinfo;
 960
 961         /*
 962          * udp_output() may need to temporarily bind or connect the current
 963          * inpcb.  As such, we don't know up front whether we will need the
 964          * pcbinfo lock or not.  Do any work to decide what is needed up
 965          * front before acquiring any locks.
 966          */
 967         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 968                 if (control)
 969                         m_freem(control);
 970                 m_freem(m);
 971                 return (EMSGSIZE);
 972         }
 973
 974         src.sin_family = 0;
 975         if (control != NULL) {
 976                 /*
 977                  * XXX: Currently, we assume all the optional information is
 978                  * stored in a single mbuf.
 979                  */
 980                 if (control->m_next) {
 981                         m_freem(control);
 982                         m_freem(m);
 983                         return (EINVAL);
 984                 }
 985                 for (; control->m_len > 0;
 986                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 987                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 988                         cm = mtod(control, struct cmsghdr *);
 989                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 990                             || cm->cmsg_len > control->m_len) {
 991                                 error = EINVAL;
 992                                 break;
 993                         }
 994                         if (cm->cmsg_level != IPPROTO_IP)
 995                                 continue;
 996
 997                         switch (cm->cmsg_type) {
 998                         case IP_SENDSRCADDR:
 999                                 if (cm->cmsg_len !=
1000                                     CMSG_LEN(sizeof(struct in_addr))) {
1001                                         error = EINVAL;
1002                                         break;
1003                                 }
1004                                 bzero(&src, sizeof(src));
1005                                 src.sin_family = AF_INET;
1006                                 src.sin_len = sizeof(src);
1007                                 src.sin_port = inp->inp_lport;
1008                                 src.sin_addr =
1009                                     *(struct in_addr *)CMSG_DATA(cm);
1010                                 break;
1011
1012                         default:
1013                                 error = ENOPROTOOPT;
1014                                 break;
1015                         }
1016                         if (error)
1017                                 break;
1018                 }
1019                 m_freem(control);
1020         }
1021         if (error) {
1022                 m_freem(m);
1023                 return (error);
1024         }
1025
1026         /*
1027          * Depending on whether or not the application has bound or connected
1028          * the socket, we may have to do varying levels of work.  The optimal
1029          * case is for a connected UDP socket, as a global lock isn't
1030          * required at all.
1031          *
1032          * In order to decide which we need, we require stability of the
1033          * inpcb binding, which we ensure by acquiring a read lock on the
1034          * inpcb.  This doesn't strictly follow the lock order, so we play
1035          * the trylock and retry game; note that we may end up with more
1036          * conservative locks than required the second time around, so later
1037          * assertions have to accept that.  Further analysis of the number of
1038          * misses under contention is required.
1039          */
1040         sin = (struct sockaddr_in *)addr;
1041         INP_RLOCK(inp);
1042         if (sin != NULL &&
1043             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1044                 INP_RUNLOCK(inp);
1045                 INP_INFO_WLOCK(&V_udbinfo);
1046                 INP_WLOCK(inp);
1047                 unlock_udbinfo = 2;
1048         } else if ((sin != NULL && (
1049             (sin->sin_addr.s_addr == INADDR_ANY) ||
1050             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1051             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1052             (inp->inp_lport == 0))) ||
1053             (src.sin_family == AF_INET)) {
1054                 if (!INP_INFO_TRY_RLOCK(&V_udbinfo)) {
1055                         INP_RUNLOCK(inp);
1056                         INP_INFO_RLOCK(&V_udbinfo);
1057                         INP_RLOCK(inp);
1058                 }
1059                 unlock_udbinfo = 1;
1060         } else
1061                 unlock_udbinfo = 0;
1062
1063         /*
1064          * If the IP_SENDSRCADDR control message was specified, override the
1065          * source address for this datagram.  Its use is invalidated if the
1066          * address thus specified is incomplete or clobbers other inpcbs.
1067          */
1068         laddr = inp->inp_laddr;
1069         lport = inp->inp_lport;
1070         if (src.sin_family == AF_INET) {
1071                 INP_INFO_LOCK_ASSERT(&V_udbinfo);
1072                 if ((lport == 0) ||
1073                     (laddr.s_addr == INADDR_ANY &&
1074                      src.sin_addr.s_addr == INADDR_ANY)) {
1075                         error = EINVAL;
1076                         goto release;
1077                 }
1078                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1079                     &laddr.s_addr, &lport, td->td_ucred);
1080                 if (error)
1081                         goto release;
1082         }
1083
1084         /*
1085          * If a UDP socket has been connected, then a local address/port will
1086          * have been selected and bound.
1087          *
1088          * If a UDP socket has not been connected to, then an explicit
1089          * destination address must be used, in which case a local
1090          * address/port may not have been selected and bound.
1091          */
1092         if (sin != NULL) {
1093                 INP_LOCK_ASSERT(inp);
1094                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1095                         error = EISCONN;
1096                         goto release;
1097                 }
1098
1099                 /*
1100                  * Jail may rewrite the destination address, so let it do
1101                  * that before we use it.
1102                  */
1103                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1104                 if (error)
1105                         goto release;
1106
1107                 /*
1108                  * If a local address or port hasn't yet been selected, or if
1109                  * the destination address needs to be rewritten due to using
1110                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1111                  * to do the heavy lifting.  Once a port is selected, we
1112                  * commit the binding back to the socket; we also commit the
1113                  * binding of the address if in jail.
1114                  *
1115                  * If we already have a valid binding and we're not
1116                  * requesting a destination address rewrite, use a fast path.
1117                  */
1118                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1119                     inp->inp_lport == 0 ||
1120                     sin->sin_addr.s_addr == INADDR_ANY ||
1121                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1122                         INP_INFO_LOCK_ASSERT(&V_udbinfo);
1123                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1124                             &lport, &faddr.s_addr, &fport, NULL,
1125                             td->td_ucred);
1126                         if (error)
1127                                 goto release;
1128
1129                         /*
1130                          * XXXRW: Why not commit the port if the address is
1131                          * !INADDR_ANY?
1132                          */
1133                         /* Commit the local port if newly assigned. */
1134                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1135                             inp->inp_lport == 0) {
1136                                 INP_INFO_WLOCK_ASSERT(&V_udbinfo);
1137                                 INP_WLOCK_ASSERT(inp);
1138                                 /*
1139                                  * Remember addr if jailed, to prevent
1140                                  * rebinding.
1141                                  */
1142                                 if (prison_flag(td->td_ucred, PR_IP4))
1143                                         inp->inp_laddr = laddr;
1144                                 inp->inp_lport = lport;
1145                                 if (in_pcbinshash(inp) != 0) {
1146                                         inp->inp_lport = 0;
1147                                         error = EAGAIN;
1148                                         goto release;
1149                                 }
1150                                 inp->inp_flags |= INP_ANONPORT;
1151                         }
1152                 } else {
1153                         faddr = sin->sin_addr;
1154                         fport = sin->sin_port;
1155                 }
1156         } else {
1157                 INP_LOCK_ASSERT(inp);
1158                 faddr = inp->inp_faddr;
1159                 fport = inp->inp_fport;
1160                 if (faddr.s_addr == INADDR_ANY) {
1161                         error = ENOTCONN;
1162                         goto release;
1163                 }
1164         }
1165
1166         /*
1167          * Calculate data length and get a mbuf for UDP, IP, and possible
1168          * link-layer headers.  Immediate slide the data pointer back forward
1169          * since we won't use that space at this layer.
1170          */
1171         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1172         if (m == NULL) {
1173                 error = ENOBUFS;
1174                 goto release;
1175         }
1176         m->m_data += max_linkhdr;
1177         m->m_len -= max_linkhdr;
1178         m->m_pkthdr.len -= max_linkhdr;
1179
1180         /*
1181          * Fill in mbuf with extended UDP header and addresses and length put
1182          * into network format.
1183          */
1184         ui = mtod(m, struct udpiphdr *);
1185         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1186         ui->ui_pr = IPPROTO_UDP;
1187         ui->ui_src = laddr;
1188         ui->ui_dst = faddr;
1189         ui->ui_sport = lport;
1190         ui->ui_dport = fport;
1191         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1192
1193         /*
1194          * Set the Don't Fragment bit in the IP header.
1195          */
1196         if (inp->inp_flags & INP_DONTFRAG) {
1197                 struct ip *ip;
1198
1199                 ip = (struct ip *)&ui->ui_i;
1200                 ip->ip_off |= IP_DF;
1201         }
1202
1203         ipflags = 0;
1204         if (inp->inp_socket->so_options & SO_DONTROUTE)
1205                 ipflags |= IP_ROUTETOIF;
1206         if (inp->inp_socket->so_options & SO_BROADCAST)
1207                 ipflags |= IP_ALLOWBROADCAST;
1208         if (inp->inp_flags & INP_ONESBCAST)
1209                 ipflags |= IP_SENDONES;
1210
1211 #ifdef MAC
1212         mac_inpcb_create_mbuf(inp, m);
1213 #endif
1214
1215         /*
1216          * Set up checksum and output datagram.
1217          */
1218         if (udp_cksum) {
1219                 if (inp->inp_flags & INP_ONESBCAST)
1220                         faddr.s_addr = INADDR_BROADCAST;
1221                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1222                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1223                 m->m_pkthdr.csum_flags = CSUM_UDP;
1224                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1225         } else
1226                 ui->ui_sum = 0;
1227         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1228         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1229         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
1230         UDPSTAT_INC(udps_opackets);
1231
1232         if (unlock_udbinfo == 2)
1233                 INP_INFO_WUNLOCK(&V_udbinfo);
1234         else if (unlock_udbinfo == 1)
1235                 INP_INFO_RUNLOCK(&V_udbinfo);
1236         error = ip_output(m, inp->inp_options, NULL, ipflags,
1237             inp->inp_moptions, inp);
1238         if (unlock_udbinfo == 2)
1239                 INP_WUNLOCK(inp);
1240         else
1241                 INP_RUNLOCK(inp);
1242         return (error);
1243
1244 release:
1245         if (unlock_udbinfo == 2) {
1246                 INP_WUNLOCK(inp);
1247                 INP_INFO_WUNLOCK(&V_udbinfo);
1248         } else if (unlock_udbinfo == 1) {
1249                 INP_RUNLOCK(inp);
1250                 INP_INFO_RUNLOCK(&V_udbinfo);
1251         } else
1252                 INP_RUNLOCK(inp);
1253         m_freem(m);
1254         return (error);
1255 }
1256
1257
1258 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1259 #ifdef INET
1260 /*
1261  * Potentially decap ESP in UDP frame.  Check for an ESP header
1262  * and optional marker; if present, strip the UDP header and
1263  * push the result through IPSec.
1264  *
1265  * Returns mbuf to be processed (potentially re-allocated) or
1266  * NULL if consumed and/or processed.
1267  */
1268 static struct mbuf *
1269 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1270 {
1271         size_t minlen, payload, skip, iphlen;
1272         caddr_t data;
1273         struct udpcb *up;
1274         struct m_tag *tag;
1275         struct udphdr *udphdr;
1276         struct ip *ip;
1277
1278         INP_RLOCK_ASSERT(inp);
1279
1280         /*
1281          * Pull up data so the longest case is contiguous:
1282          *    IP/UDP hdr + non ESP marker + ESP hdr.
1283          */
1284         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1285         if (minlen > m->m_pkthdr.len)
1286                 minlen = m->m_pkthdr.len;
1287         if ((m = m_pullup(m, minlen)) == NULL) {
1288                 V_ipsec4stat.in_inval++;
1289                 return (NULL);          /* Bypass caller processing. */
1290         }
1291         data = mtod(m, caddr_t);        /* Points to ip header. */
1292         payload = m->m_len - off;       /* Size of payload. */
1293
1294         if (payload == 1 && data[off] == '\xff')
1295                 return (m);             /* NB: keepalive packet, no decap. */
1296
1297         up = intoudpcb(inp);
1298         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1299         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1300             ("u_flags 0x%x", up->u_flags));
1301
1302         /*
1303          * Check that the payload is large enough to hold an
1304          * ESP header and compute the amount of data to remove.
1305          *
1306          * NB: the caller has already done a pullup for us.
1307          * XXX can we assume alignment and eliminate bcopys?
1308          */
1309         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1310                 /*
1311                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1312                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1313                  * possible AH mode non-IKE marker+non-ESP marker
1314                  * from draft-ietf-ipsec-udp-encaps-00.txt.
1315                  */
1316                 uint64_t marker;
1317
1318                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1319                         return (m);     /* NB: no decap. */
1320                 bcopy(data + off, &marker, sizeof(uint64_t));
1321                 if (marker != 0)        /* Non-IKE marker. */
1322                         return (m);     /* NB: no decap. */
1323                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1324         } else {
1325                 uint32_t spi;
1326
1327                 if (payload <= sizeof(struct esp)) {
1328                         V_ipsec4stat.in_inval++;
1329                         m_freem(m);
1330                         return (NULL);  /* Discard. */
1331                 }
1332                 bcopy(data + off, &spi, sizeof(uint32_t));
1333                 if (spi == 0)           /* Non-ESP marker. */
1334                         return (m);     /* NB: no decap. */
1335                 skip = sizeof(struct udphdr);
1336         }
1337
1338         /*
1339          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1340          * the UDP ports. This is required if we want to select
1341          * the right SPD for multiple hosts behind same NAT.
1342          *
1343          * NB: ports are maintained in network byte order everywhere
1344          *     in the NAT-T code.
1345          */
1346         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1347                 2 * sizeof(uint16_t), M_NOWAIT);
1348         if (tag == NULL) {
1349                 V_ipsec4stat.in_nomem++;
1350                 m_freem(m);
1351                 return (NULL);          /* Discard. */
1352         }
1353         iphlen = off - sizeof(struct udphdr);
1354         udphdr = (struct udphdr *)(data + iphlen);
1355         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1356         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1357         m_tag_prepend(m, tag);
1358
1359         /*
1360          * Remove the UDP header (and possibly the non ESP marker)
1361          * IP header length is iphlen
1362          * Before:
1363          *   <--- off --->
1364          *   +----+------+-----+
1365          *   | IP |  UDP | ESP |
1366          *   +----+------+-----+
1367          *        <-skip->
1368          * After:
1369          *          +----+-----+
1370          *          | IP | ESP |
1371          *          +----+-----+
1372          *   <-skip->
1373          */
1374         ovbcopy(data, data + skip, iphlen);
1375         m_adj(m, skip);
1376
1377         ip = mtod(m, struct ip *);
1378         ip->ip_len -= skip;
1379         ip->ip_p = IPPROTO_ESP;
1380
1381         /*
1382          * We cannot yet update the cksums so clear any
1383          * h/w cksum flags as they are no longer valid.
1384          */
1385         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1386                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1387
1388         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1389         return (NULL);                  /* NB: consumed, bypass processing. */
1390 }
1391 #endif /* INET */
1392 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1393
1394 static void
1395 udp_abort(struct socket *so)
1396 {
1397         struct inpcb *inp;
1398
1399         inp = sotoinpcb(so);
1400         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1401         INP_INFO_WLOCK(&V_udbinfo);
1402         INP_WLOCK(inp);
1403         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1404                 in_pcbdisconnect(inp);
1405                 inp->inp_laddr.s_addr = INADDR_ANY;
1406                 soisdisconnected(so);
1407         }
1408         INP_WUNLOCK(inp);
1409         INP_INFO_WUNLOCK(&V_udbinfo);
1410 }
1411
1412 static int
1413 udp_attach(struct socket *so, int proto, struct thread *td)
1414 {
1415         struct inpcb *inp;
1416         int error;
1417
1418         inp = sotoinpcb(so);
1419         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1420         error = soreserve(so, udp_sendspace, udp_recvspace);
1421         if (error)
1422                 return (error);
1423         INP_INFO_WLOCK(&V_udbinfo);
1424         error = in_pcballoc(so, &V_udbinfo);
1425         if (error) {
1426                 INP_INFO_WUNLOCK(&V_udbinfo);
1427                 return (error);
1428         }
1429
1430         inp = (struct inpcb *)so->so_pcb;
1431         inp->inp_vflag |= INP_IPV4;
1432         inp->inp_ip_ttl = V_ip_defttl;
1433
1434         error = udp_newudpcb(inp);
1435         if (error) {
1436                 in_pcbdetach(inp);
1437                 in_pcbfree(inp);
1438                 INP_INFO_WUNLOCK(&V_udbinfo);
1439                 return (error);
1440         }
1441
1442         INP_WUNLOCK(inp);
1443         INP_INFO_WUNLOCK(&V_udbinfo);
1444         return (0);
1445 }
1446
1447 int
1448 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1449 {
1450         struct inpcb *inp;
1451         struct udpcb *up;
1452
1453         KASSERT(so->so_type == SOCK_DGRAM, ("udp_set_kernel_tunneling: !dgram"));
1454         KASSERT(so->so_pcb != NULL, ("udp_set_kernel_tunneling: NULL inp"));
1455         if (so->so_type != SOCK_DGRAM) {
1456                 /* Not UDP socket... sorry! */
1457                 return (ENOTSUP);
1458         }
1459         inp = (struct inpcb *)so->so_pcb;
1460         if (inp == NULL) {
1461                 /* NULL INP? */
1462                 return (EINVAL);
1463         }
1464         INP_WLOCK(inp);
1465         up = intoudpcb(inp);
1466         if (up->u_tun_func != NULL) {
1467                 INP_WUNLOCK(inp);
1468                 return (EBUSY);
1469         }
1470         up->u_tun_func = f;
1471         INP_WUNLOCK(inp);
1472         return (0);
1473 }
1474
1475 static int
1476 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1477 {
1478         struct inpcb *inp;
1479         int error;
1480
1481         inp = sotoinpcb(so);
1482         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1483         INP_INFO_WLOCK(&V_udbinfo);
1484         INP_WLOCK(inp);
1485         error = in_pcbbind(inp, nam, td->td_ucred);
1486         INP_WUNLOCK(inp);
1487         INP_INFO_WUNLOCK(&V_udbinfo);
1488         return (error);
1489 }
1490
1491 static void
1492 udp_close(struct socket *so)
1493 {
1494         struct inpcb *inp;
1495
1496         inp = sotoinpcb(so);
1497         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1498         INP_INFO_WLOCK(&V_udbinfo);
1499         INP_WLOCK(inp);
1500         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1501                 in_pcbdisconnect(inp);
1502                 inp->inp_laddr.s_addr = INADDR_ANY;
1503                 soisdisconnected(so);
1504         }
1505         INP_WUNLOCK(inp);
1506         INP_INFO_WUNLOCK(&V_udbinfo);
1507 }
1508
1509 static int
1510 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1511 {
1512         struct inpcb *inp;
1513         int error;
1514         struct sockaddr_in *sin;
1515
1516         inp = sotoinpcb(so);
1517         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1518         INP_INFO_WLOCK(&V_udbinfo);
1519         INP_WLOCK(inp);
1520         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1521                 INP_WUNLOCK(inp);
1522                 INP_INFO_WUNLOCK(&V_udbinfo);
1523                 return (EISCONN);
1524         }
1525         sin = (struct sockaddr_in *)nam;
1526         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1527         if (error != 0) {
1528                 INP_WUNLOCK(inp);
1529                 INP_INFO_WUNLOCK(&V_udbinfo);
1530                 return (error);
1531         }
1532         error = in_pcbconnect(inp, nam, td->td_ucred);
1533         if (error == 0)
1534                 soisconnected(so);
1535         INP_WUNLOCK(inp);
1536         INP_INFO_WUNLOCK(&V_udbinfo);
1537         return (error);
1538 }
1539
1540 static void
1541 udp_detach(struct socket *so)
1542 {
1543         struct inpcb *inp;
1544         struct udpcb *up;
1545
1546         inp = sotoinpcb(so);
1547         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1548         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1549             ("udp_detach: not disconnected"));
1550         INP_INFO_WLOCK(&V_udbinfo);
1551         INP_WLOCK(inp);
1552         up = intoudpcb(inp);
1553         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1554         inp->inp_ppcb = NULL;
1555         in_pcbdetach(inp);
1556         in_pcbfree(inp);
1557         INP_INFO_WUNLOCK(&V_udbinfo);
1558         udp_discardcb(up);
1559 }
1560
1561 static int
1562 udp_disconnect(struct socket *so)
1563 {
1564         struct inpcb *inp;
1565
1566         inp = sotoinpcb(so);
1567         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1568         INP_INFO_WLOCK(&V_udbinfo);
1569         INP_WLOCK(inp);
1570         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1571                 INP_WUNLOCK(inp);
1572                 INP_INFO_WUNLOCK(&V_udbinfo);
1573                 return (ENOTCONN);
1574         }
1575
1576         in_pcbdisconnect(inp);
1577         inp->inp_laddr.s_addr = INADDR_ANY;
1578         SOCK_LOCK(so);
1579         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1580         SOCK_UNLOCK(so);
1581         INP_WUNLOCK(inp);
1582         INP_INFO_WUNLOCK(&V_udbinfo);
1583         return (0);
1584 }
1585
1586 static int
1587 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1588     struct mbuf *control, struct thread *td)
1589 {
1590         struct inpcb *inp;
1591
1592         inp = sotoinpcb(so);
1593         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1594         return (udp_output(inp, m, addr, control, td));
1595 }
1596
1597 int
1598 udp_shutdown(struct socket *so)
1599 {
1600         struct inpcb *inp;
1601
1602         inp = sotoinpcb(so);
1603         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1604         INP_WLOCK(inp);
1605         socantsendmore(so);
1606         INP_WUNLOCK(inp);
1607         return (0);
1608 }
1609
1610 struct pr_usrreqs udp_usrreqs = {
1611         .pru_abort =            udp_abort,
1612         .pru_attach =           udp_attach,
1613         .pru_bind =             udp_bind,
1614         .pru_connect =          udp_connect,
1615         .pru_control =          in_control,
1616         .pru_detach =           udp_detach,
1617         .pru_disconnect =       udp_disconnect,
1618         .pru_peeraddr =         in_getpeeraddr,
1619         .pru_send =             udp_send,
1620         .pru_soreceive =        soreceive_dgram,
1621         .pru_sosend =           sosend_dgram,
1622         .pru_shutdown =         udp_shutdown,
1623         .pru_sockaddr =         in_getsockaddr,
1624         .pru_sosetlabel =       in_pcbsosetlabel,
1625         .pru_close =            udp_close,
1626 };