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  * Copyright (c) 2010-2011 Juniper Networks, Inc.
   6  * All rights reserved.
   7  *
   8  * Portions of this software were developed by Robert N. M. Watson under
   9  * contract to Juniper Networks, Inc.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  36  */
  37
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD$");
  40
  41 #include "opt_ipfw.h"
  42 #include "opt_inet.h"
  43 #include "opt_inet6.h"
  44 #include "opt_ipsec.h"
  45
  46 #include <sys/param.h>
  47 #include <sys/domain.h>
  48 #include <sys/eventhandler.h>
  49 #include <sys/jail.h>
  50 #include <sys/kernel.h>
  51 #include <sys/lock.h>
  52 #include <sys/malloc.h>
  53 #include <sys/mbuf.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/protosw.h>
  57 #include <sys/signalvar.h>
  58 #include <sys/socket.h>
  59 #include <sys/socketvar.h>
  60 #include <sys/sx.h>
  61 #include <sys/sysctl.h>
  62 #include <sys/syslog.h>
  63 #include <sys/systm.h>
  64
  65 #include <vm/uma.h>
  66
  67 #include <net/if.h>
  68 #include <net/route.h>
  69
  70 #include <netinet/in.h>
  71 #include <netinet/in_pcb.h>
  72 #include <netinet/in_systm.h>
  73 #include <netinet/in_var.h>
  74 #include <netinet/ip.h>
  75 #ifdef INET6
  76 #include <netinet/ip6.h>
  77 #endif
  78 #include <netinet/ip_icmp.h>
  79 #include <netinet/icmp_var.h>
  80 #include <netinet/ip_var.h>
  81 #include <netinet/ip_options.h>
  82 #ifdef INET6
  83 #include <netinet6/ip6_var.h>
  84 #endif
  85 #include <netinet/udp.h>
  86 #include <netinet/udp_var.h>
  87
  88 #ifdef IPSEC
  89 #include <netipsec/ipsec.h>
  90 #include <netipsec/esp.h>
  91 #endif
  92
  93 #include <machine/in_cksum.h>
  94
  95 #include <security/mac/mac_framework.h>
  96
  97 /*
  98  * UDP protocol implementation.
  99  * Per RFC 768, August, 1980.
 100  */
 101
 102 /*
 103  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
 104  * removes the only data integrity mechanism for packets and malformed
 105  * packets that would otherwise be discarded due to bad checksums, and may
 106  * cause problems (especially for NFS data blocks).
 107  */
 108 VNET_DEFINE(int, udp_cksum) = 1;
 109 SYSCTL_VNET_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
 110     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
 111
 112 int     udp_log_in_vain = 0;
 113 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 114     &udp_log_in_vain, 0, "Log all incoming UDP packets");
 115
 116 VNET_DEFINE(int, udp_blackhole) = 0;
 117 SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 118     &VNET_NAME(udp_blackhole), 0,
 119     "Do not send port unreachables for refused connects");
 120
 121 u_long  udp_sendspace = 9216;           /* really max datagram size */
 122                                         /* 40 1K datagrams */
 123 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 124     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 125
 126 u_long  udp_recvspace = 40 * (1024 +
 127 #ifdef INET6
 128                                       sizeof(struct sockaddr_in6)
 129 #else
 130                                       sizeof(struct sockaddr_in)
 131 #endif
 132                                       );
 133
 134 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 135     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 136
 137 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
 138 VNET_DEFINE(struct inpcbinfo, udbinfo);
 139 static VNET_DEFINE(uma_zone_t, udpcb_zone);
 140 #define V_udpcb_zone                    VNET(udpcb_zone)
 141
 142 #ifndef UDBHASHSIZE
 143 #define UDBHASHSIZE     128
 144 #endif
 145
 146 VNET_DEFINE(struct udpstat, udpstat);           /* from udp_var.h */
 147 SYSCTL_VNET_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
 148     &VNET_NAME(udpstat), udpstat,
 149     "UDP statistics (struct udpstat, netinet/udp_var.h)");
 150
 151 #ifdef INET
 152 static void     udp_detach(struct socket *so);
 153 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 154                     struct mbuf *, struct thread *);
 155 #endif
 156
 157 #ifdef IPSEC
 158 #ifdef IPSEC_NAT_T
 159 #define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
 160 #ifdef INET
 161 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
 162 #endif
 163 #endif /* IPSEC_NAT_T */
 164 #endif /* IPSEC */
 165
 166 static void
 167 udp_zone_change(void *tag)
 168 {
 169
 170         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 171         uma_zone_set_max(V_udpcb_zone, maxsockets);
 172 }
 173
 174 static int
 175 udp_inpcb_init(void *mem, int size, int flags)
 176 {
 177         struct inpcb *inp;
 178
 179         inp = mem;
 180         INP_LOCK_INIT(inp, "inp", "udpinp");
 181         return (0);
 182 }
 183
 184 void
 185 udp_init(void)
 186 {
 187
 188         in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
 189             "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE,
 190             IPI_HASHFIELDS_2TUPLE);
 191         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
 192             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 193         uma_zone_set_max(V_udpcb_zone, maxsockets);
 194         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 195             EVENTHANDLER_PRI_ANY);
 196 }
 197
 198 /*
 199  * Kernel module interface for updating udpstat.  The argument is an index
 200  * into udpstat treated as an array of u_long.  While this encodes the
 201  * general layout of udpstat into the caller, it doesn't encode its location,
 202  * so that future changes to add, for example, per-CPU stats support won't
 203  * cause binary compatibility problems for kernel modules.
 204  */
 205 void
 206 kmod_udpstat_inc(int statnum)
 207 {
 208
 209         (*((u_long *)&V_udpstat + statnum))++;
 210 }
 211
 212 int
 213 udp_newudpcb(struct inpcb *inp)
 214 {
 215         struct udpcb *up;
 216
 217         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
 218         if (up == NULL)
 219                 return (ENOBUFS);
 220         inp->inp_ppcb = up;
 221         return (0);
 222 }
 223
 224 void
 225 udp_discardcb(struct udpcb *up)
 226 {
 227
 228         uma_zfree(V_udpcb_zone, up);
 229 }
 230
 231 #ifdef VIMAGE
 232 void
 233 udp_destroy(void)
 234 {
 235
 236         in_pcbinfo_destroy(&V_udbinfo);
 237         uma_zdestroy(V_udpcb_zone);
 238 }
 239 #endif
 240
 241 #ifdef INET
 242 /*
 243  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 244  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 245  * contains the source address.  If the socket ends up being an IPv6 socket,
 246  * udp_append() will convert to a sockaddr_in6 before passing the address
 247  * into the socket code.
 248  */
 249 static void
 250 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 251     struct sockaddr_in *udp_in)
 252 {
 253         struct sockaddr *append_sa;
 254         struct socket *so;
 255         struct mbuf *opts = 0;
 256 #ifdef INET6
 257         struct sockaddr_in6 udp_in6;
 258 #endif
 259         struct udpcb *up;
 260
 261         INP_LOCK_ASSERT(inp);
 262
 263         /*
 264          * Engage the tunneling protocol.
 265          */
 266         up = intoudpcb(inp);
 267         if (up->u_tun_func != NULL) {
 268                 (*up->u_tun_func)(n, off, inp);
 269                 return;
 270         }
 271
 272         if (n == NULL)
 273                 return;
 274
 275         off += sizeof(struct udphdr);
 276
 277 #ifdef IPSEC
 278         /* Check AH/ESP integrity. */
 279         if (ipsec4_in_reject(n, inp)) {
 280                 m_freem(n);
 281                 V_ipsec4stat.in_polvio++;
 282                 return;
 283         }
 284 #ifdef IPSEC_NAT_T
 285         up = intoudpcb(inp);
 286         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
 287         if (up->u_flags & UF_ESPINUDP_ALL) {    /* IPSec UDP encaps. */
 288                 n = udp4_espdecap(inp, n, off);
 289                 if (n == NULL)                          /* Consumed. */
 290                         return;
 291         }
 292 #endif /* IPSEC_NAT_T */
 293 #endif /* IPSEC */
 294 #ifdef MAC
 295         if (mac_inpcb_check_deliver(inp, n) != 0) {
 296                 m_freem(n);
 297                 return;
 298         }
 299 #endif /* MAC */
 300         if (inp->inp_flags & INP_CONTROLOPTS ||
 301             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 302 #ifdef INET6
 303                 if (inp->inp_vflag & INP_IPV6)
 304                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
 305                 else
 306 #endif /* INET6 */
 307                         ip_savecontrol(inp, &opts, ip, n);
 308         }
 309 #ifdef INET6
 310         if (inp->inp_vflag & INP_IPV6) {
 311                 bzero(&udp_in6, sizeof(udp_in6));
 312                 udp_in6.sin6_len = sizeof(udp_in6);
 313                 udp_in6.sin6_family = AF_INET6;
 314                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 315                 append_sa = (struct sockaddr *)&udp_in6;
 316         } else
 317 #endif /* INET6 */
 318                 append_sa = (struct sockaddr *)udp_in;
 319         m_adj(n, off);
 320
 321         so = inp->inp_socket;
 322         SOCKBUF_LOCK(&so->so_rcv);
 323         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 324                 SOCKBUF_UNLOCK(&so->so_rcv);
 325                 m_freem(n);
 326                 if (opts)
 327                         m_freem(opts);
 328                 UDPSTAT_INC(udps_fullsock);
 329         } else
 330                 sorwakeup_locked(so);
 331 }
 332
 333 void
 334 udp_input(struct mbuf *m, int off)
 335 {
 336         int iphlen = off;
 337         struct ip *ip;
 338         struct udphdr *uh;
 339         struct ifnet *ifp;
 340         struct inpcb *inp;
 341         int len;
 342         struct ip save_ip;
 343         struct sockaddr_in udp_in;
 344 #ifdef IPFIREWALL_FORWARD
 345         struct m_tag *fwd_tag;
 346 #endif
 347
 348         ifp = m->m_pkthdr.rcvif;
 349         UDPSTAT_INC(udps_ipackets);
 350
 351         /*
 352          * Strip IP options, if any; should skip this, make available to
 353          * user, and use on returned packets, but we don't yet have a way to
 354          * check the checksum with options still present.
 355          */
 356         if (iphlen > sizeof (struct ip)) {
 357                 ip_stripoptions(m, (struct mbuf *)0);
 358                 iphlen = sizeof(struct ip);
 359         }
 360
 361         /*
 362          * Get IP and UDP header together in first mbuf.
 363          */
 364         ip = mtod(m, struct ip *);
 365         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 366                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 367                         UDPSTAT_INC(udps_hdrops);
 368                         return;
 369                 }
 370                 ip = mtod(m, struct ip *);
 371         }
 372         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 373
 374         /*
 375          * Destination port of 0 is illegal, based on RFC768.
 376          */
 377         if (uh->uh_dport == 0)
 378                 goto badunlocked;
 379
 380         /*
 381          * Construct sockaddr format source address.  Stuff source address
 382          * and datagram in user buffer.
 383          */
 384         bzero(&udp_in, sizeof(udp_in));
 385         udp_in.sin_len = sizeof(udp_in);
 386         udp_in.sin_family = AF_INET;
 387         udp_in.sin_port = uh->uh_sport;
 388         udp_in.sin_addr = ip->ip_src;
 389
 390         /*
 391          * Make mbuf data length reflect UDP length.  If not enough data to
 392          * reflect UDP length, drop.
 393          */
 394         len = ntohs((u_short)uh->uh_ulen);
 395         if (ip->ip_len != len) {
 396                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 397                         UDPSTAT_INC(udps_badlen);
 398                         goto badunlocked;
 399                 }
 400                 m_adj(m, len - ip->ip_len);
 401                 /* ip->ip_len = len; */
 402         }
 403
 404         /*
 405          * Save a copy of the IP header in case we want restore it for
 406          * sending an ICMP error message in response.
 407          */
 408         if (!V_udp_blackhole)
 409                 save_ip = *ip;
 410         else
 411                 memset(&save_ip, 0, sizeof(save_ip));
 412
 413         /*
 414          * Checksum extended UDP header and data.
 415          */
 416         if (uh->uh_sum) {
 417                 u_short uh_sum;
 418
 419                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 420                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 421                                 uh_sum = m->m_pkthdr.csum_data;
 422                         else
 423                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 424                                     ip->ip_dst.s_addr, htonl((u_short)len +
 425                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 426                         uh_sum ^= 0xffff;
 427                 } else {
 428                         char b[9];
 429
 430                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 431                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 432                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 433                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 434                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 435                 }
 436                 if (uh_sum) {
 437                         UDPSTAT_INC(udps_badsum);
 438                         m_freem(m);
 439                         return;
 440                 }
 441         } else
 442                 UDPSTAT_INC(udps_nosum);
 443
 444         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 445             in_broadcast(ip->ip_dst, ifp)) {
 446                 struct inpcb *last;
 447                 struct ip_moptions *imo;
 448
 449                 INP_INFO_RLOCK(&V_udbinfo);
 450                 last = NULL;
 451                 LIST_FOREACH(inp, &V_udb, inp_list) {
 452                         if (inp->inp_lport != uh->uh_dport)
 453                                 continue;
 454 #ifdef INET6
 455                         if ((inp->inp_vflag & INP_IPV4) == 0)
 456                                 continue;
 457 #endif
 458                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 459                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 460                                 continue;
 461                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 462                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 463                                 continue;
 464                         if (inp->inp_fport != 0 &&
 465                             inp->inp_fport != uh->uh_sport)
 466                                 continue;
 467
 468                         INP_RLOCK(inp);
 469
 470                         /*
 471                          * XXXRW: Because we weren't holding either the inpcb
 472                          * or the hash lock when we checked for a match
 473                          * before, we should probably recheck now that the
 474                          * inpcb lock is held.
 475                          */
 476
 477                         /*
 478                          * Handle socket delivery policy for any-source
 479                          * and source-specific multicast. [RFC3678]
 480                          */
 481                         imo = inp->inp_moptions;
 482                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 483                                 struct sockaddr_in       group;
 484                                 int                      blocked;
 485                                 if (imo == NULL) {
 486                                         INP_RUNLOCK(inp);
 487                                         continue;
 488                                 }
 489                                 bzero(&group, sizeof(struct sockaddr_in));
 490                                 group.sin_len = sizeof(struct sockaddr_in);
 491                                 group.sin_family = AF_INET;
 492                                 group.sin_addr = ip->ip_dst;
 493
 494                                 blocked = imo_multi_filter(imo, ifp,
 495                                         (struct sockaddr *)&group,
 496                                         (struct sockaddr *)&udp_in);
 497                                 if (blocked != MCAST_PASS) {
 498                                         if (blocked == MCAST_NOTGMEMBER)
 499                                                 IPSTAT_INC(ips_notmember);
 500                                         if (blocked == MCAST_NOTSMEMBER ||
 501                                             blocked == MCAST_MUTED)
 502                                                 UDPSTAT_INC(udps_filtermcast);
 503                                         INP_RUNLOCK(inp);
 504                                         continue;
 505                                 }
 506                         }
 507                         if (last != NULL) {
 508                                 struct mbuf *n;
 509
 510                                 n = m_copy(m, 0, M_COPYALL);
 511                                 udp_append(last, ip, n, iphlen, &udp_in);
 512                                 INP_RUNLOCK(last);
 513                         }
 514                         last = inp;
 515                         /*
 516                          * Don't look for additional matches if this one does
 517                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 518                          * socket options set.  This heuristic avoids
 519                          * searching through all pcbs in the common case of a
 520                          * non-shared port.  It assumes that an application
 521                          * will never clear these options after setting them.
 522                          */
 523                         if ((last->inp_socket->so_options &
 524                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 525                                 break;
 526                 }
 527
 528                 if (last == NULL) {
 529                         /*
 530                          * No matching pcb found; discard datagram.  (No need
 531                          * to send an ICMP Port Unreachable for a broadcast
 532                          * or multicast datgram.)
 533                          */
 534                         UDPSTAT_INC(udps_noportbcast);
 535                         if (inp)
 536                                 INP_RUNLOCK(inp);
 537                         INP_INFO_RUNLOCK(&V_udbinfo);
 538                         goto badunlocked;
 539                 }
 540                 udp_append(last, ip, m, iphlen, &udp_in);
 541                 INP_RUNLOCK(last);
 542                 INP_INFO_RUNLOCK(&V_udbinfo);
 543                 return;
 544         }
 545
 546         /*
 547          * Locate pcb for datagram.
 548          */
 549 #ifdef IPFIREWALL_FORWARD
 550         /*
 551          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 552          */
 553         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 554         if (fwd_tag != NULL) {
 555                 struct sockaddr_in *next_hop;
 556
 557                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 558
 559                 /*
 560                  * Transparently forwarded. Pretend to be the destination.
 561                  * Already got one like this?
 562                  */
 563                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 564                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
 565                 if (!inp) {
 566                         /*
 567                          * It's new.  Try to find the ambushing socket.
 568                          * Because we've rewritten the destination address,
 569                          * any hardware-generated hash is ignored.
 570                          */
 571                         inp = in_pcblookup(&V_udbinfo, ip->ip_src,
 572                             uh->uh_sport, next_hop->sin_addr,
 573                             next_hop->sin_port ? htons(next_hop->sin_port) :
 574                             uh->uh_dport, INPLOOKUP_WILDCARD |
 575                             INPLOOKUP_RLOCKPCB, ifp);
 576                 }
 577                 /* Remove the tag from the packet. We don't need it anymore. */
 578                 m_tag_delete(m, fwd_tag);
 579         } else
 580 #endif /* IPFIREWALL_FORWARD */
 581                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 582                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
 583                     INPLOOKUP_RLOCKPCB, ifp, m);
 584         if (inp == NULL) {
 585                 if (udp_log_in_vain) {
 586                         char buf[4*sizeof "123"];
 587
 588                         strcpy(buf, inet_ntoa(ip->ip_dst));
 589                         log(LOG_INFO,
 590                             "Connection attempt to UDP %s:%d from %s:%d\n",
 591                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 592                             ntohs(uh->uh_sport));
 593                 }
 594                 UDPSTAT_INC(udps_noport);
 595                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 596                         UDPSTAT_INC(udps_noportbcast);
 597                         goto badunlocked;
 598                 }
 599                 if (V_udp_blackhole)
 600                         goto badunlocked;
 601                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 602                         goto badunlocked;
 603                 *ip = save_ip;
 604                 ip->ip_len += iphlen;
 605                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 606                 return;
 607         }
 608
 609         /*
 610          * Check the minimum TTL for socket.
 611          */
 612         INP_RLOCK_ASSERT(inp);
 613         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 614                 INP_RUNLOCK(inp);
 615                 m_freem(m);
 616                 return;
 617         }
 618         udp_append(inp, ip, m, iphlen, &udp_in);
 619         INP_RUNLOCK(inp);
 620         return;
 621
 622 badunlocked:
 623         m_freem(m);
 624 }
 625 #endif /* INET */
 626
 627 /*
 628  * Notify a udp user of an asynchronous error; just wake up so that they can
 629  * collect error status.
 630  */
 631 struct inpcb *
 632 udp_notify(struct inpcb *inp, int errno)
 633 {
 634
 635         /*
 636          * While udp_ctlinput() always calls udp_notify() with a read lock
 637          * when invoking it directly, in_pcbnotifyall() currently uses write
 638          * locks due to sharing code with TCP.  For now, accept either a read
 639          * or a write lock, but a read lock is sufficient.
 640          */
 641         INP_LOCK_ASSERT(inp);
 642
 643         inp->inp_socket->so_error = errno;
 644         sorwakeup(inp->inp_socket);
 645         sowwakeup(inp->inp_socket);
 646         return (inp);
 647 }
 648
 649 #ifdef INET
 650 void
 651 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 652 {
 653         struct ip *ip = vip;
 654         struct udphdr *uh;
 655         struct in_addr faddr;
 656         struct inpcb *inp;
 657
 658         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 659         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 660                 return;
 661
 662         /*
 663          * Redirects don't need to be handled up here.
 664          */
 665         if (PRC_IS_REDIRECT(cmd))
 666                 return;
 667
 668         /*
 669          * Hostdead is ugly because it goes linearly through all PCBs.
 670          *
 671          * XXX: We never get this from ICMP, otherwise it makes an excellent
 672          * DoS attack on machines with many connections.
 673          */
 674         if (cmd == PRC_HOSTDEAD)
 675                 ip = NULL;
 676         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 677                 return;
 678         if (ip != NULL) {
 679                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 680                 inp = in_pcblookup(&V_udbinfo, faddr, uh->uh_dport,
 681                     ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
 682                 if (inp != NULL) {
 683                         INP_RLOCK_ASSERT(inp);
 684                         if (inp->inp_socket != NULL) {
 685                                 udp_notify(inp, inetctlerrmap[cmd]);
 686                         }
 687                         INP_RUNLOCK(inp);
 688                 }
 689         } else
 690                 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
 691                     udp_notify);
 692 }
 693 #endif /* INET */
 694
 695 static int
 696 udp_pcblist(SYSCTL_HANDLER_ARGS)
 697 {
 698         int error, i, n;
 699         struct inpcb *inp, **inp_list;
 700         inp_gen_t gencnt;
 701         struct xinpgen xig;
 702
 703         /*
 704          * The process of preparing the PCB list is too time-consuming and
 705          * resource-intensive to repeat twice on every request.
 706          */
 707         if (req->oldptr == 0) {
 708                 n = V_udbinfo.ipi_count;
 709                 n += imax(n / 8, 10);
 710                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 711                 return (0);
 712         }
 713
 714         if (req->newptr != 0)
 715                 return (EPERM);
 716
 717         /*
 718          * OK, now we're committed to doing something.
 719          */
 720         INP_INFO_RLOCK(&V_udbinfo);
 721         gencnt = V_udbinfo.ipi_gencnt;
 722         n = V_udbinfo.ipi_count;
 723         INP_INFO_RUNLOCK(&V_udbinfo);
 724
 725         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 726                 + n * sizeof(struct xinpcb));
 727         if (error != 0)
 728                 return (error);
 729
 730         xig.xig_len = sizeof xig;
 731         xig.xig_count = n;
 732         xig.xig_gen = gencnt;
 733         xig.xig_sogen = so_gencnt;
 734         error = SYSCTL_OUT(req, &xig, sizeof xig);
 735         if (error)
 736                 return (error);
 737
 738         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 739         if (inp_list == 0)
 740                 return (ENOMEM);
 741
 742         INP_INFO_RLOCK(&V_udbinfo);
 743         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
 744              inp = LIST_NEXT(inp, inp_list)) {
 745                 INP_WLOCK(inp);
 746                 if (inp->inp_gencnt <= gencnt &&
 747                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
 748                         in_pcbref(inp);
 749                         inp_list[i++] = inp;
 750                 }
 751                 INP_WUNLOCK(inp);
 752         }
 753         INP_INFO_RUNLOCK(&V_udbinfo);
 754         n = i;
 755
 756         error = 0;
 757         for (i = 0; i < n; i++) {
 758                 inp = inp_list[i];
 759                 INP_RLOCK(inp);
 760                 if (inp->inp_gencnt <= gencnt) {
 761                         struct xinpcb xi;
 762
 763                         bzero(&xi, sizeof(xi));
 764                         xi.xi_len = sizeof xi;
 765                         /* XXX should avoid extra copy */
 766                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 767                         if (inp->inp_socket)
 768                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 769                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 770                         INP_RUNLOCK(inp);
 771                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 772                 } else
 773                         INP_RUNLOCK(inp);
 774         }
 775         INP_INFO_WLOCK(&V_udbinfo);
 776         for (i = 0; i < n; i++) {
 777                 inp = inp_list[i];
 778                 INP_RLOCK(inp);
 779                 if (!in_pcbrele_rlocked(inp))
 780                         INP_RUNLOCK(inp);
 781         }
 782         INP_INFO_WUNLOCK(&V_udbinfo);
 783
 784         if (!error) {
 785                 /*
 786                  * Give the user an updated idea of our state.  If the
 787                  * generation differs from what we told her before, she knows
 788                  * that something happened while we were processing this
 789                  * request, and it might be necessary to retry.
 790                  */
 791                 INP_INFO_RLOCK(&V_udbinfo);
 792                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 793                 xig.xig_sogen = so_gencnt;
 794                 xig.xig_count = V_udbinfo.ipi_count;
 795                 INP_INFO_RUNLOCK(&V_udbinfo);
 796                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 797         }
 798         free(inp_list, M_TEMP);
 799         return (error);
 800 }
 801
 802 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
 803     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
 804     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 805
 806 #ifdef INET
 807 static int
 808 udp_getcred(SYSCTL_HANDLER_ARGS)
 809 {
 810         struct xucred xuc;
 811         struct sockaddr_in addrs[2];
 812         struct inpcb *inp;
 813         int error;
 814
 815         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 816         if (error)
 817                 return (error);
 818         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 819         if (error)
 820                 return (error);
 821         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 822             addrs[0].sin_addr, addrs[0].sin_port,
 823             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 824         if (inp != NULL) {
 825                 INP_RLOCK_ASSERT(inp);
 826                 if (inp->inp_socket == NULL)
 827                         error = ENOENT;
 828                 if (error == 0)
 829                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 830                 if (error == 0)
 831                         cru2x(inp->inp_cred, &xuc);
 832                 INP_RUNLOCK(inp);
 833         } else
 834                 error = ENOENT;
 835         if (error == 0)
 836                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 837         return (error);
 838 }
 839
 840 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 841     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 842     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 843 #endif /* INET */
 844
 845 int
 846 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 847 {
 848         int error = 0, optval;
 849         struct inpcb *inp;
 850 #ifdef IPSEC_NAT_T
 851         struct udpcb *up;
 852 #endif
 853
 854         inp = sotoinpcb(so);
 855         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 856         INP_WLOCK(inp);
 857         if (sopt->sopt_level != IPPROTO_UDP) {
 858 #ifdef INET6
 859                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 860                         INP_WUNLOCK(inp);
 861                         error = ip6_ctloutput(so, sopt);
 862                 }
 863 #endif
 864 #if defined(INET) && defined(INET6)
 865                 else
 866 #endif
 867 #ifdef INET
 868                 {
 869                         INP_WUNLOCK(inp);
 870                         error = ip_ctloutput(so, sopt);
 871                 }
 872 #endif
 873                 return (error);
 874         }
 875
 876         switch (sopt->sopt_dir) {
 877         case SOPT_SET:
 878                 switch (sopt->sopt_name) {
 879                 case UDP_ENCAP:
 880                         INP_WUNLOCK(inp);
 881                         error = sooptcopyin(sopt, &optval, sizeof optval,
 882                                             sizeof optval);
 883                         if (error)
 884                                 break;
 885                         inp = sotoinpcb(so);
 886                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 887                         INP_WLOCK(inp);
 888 #ifdef IPSEC_NAT_T
 889                         up = intoudpcb(inp);
 890                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 891 #endif
 892                         switch (optval) {
 893                         case 0:
 894                                 /* Clear all UDP encap. */
 895 #ifdef IPSEC_NAT_T
 896                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 897 #endif
 898                                 break;
 899 #ifdef IPSEC_NAT_T
 900                         case UDP_ENCAP_ESPINUDP:
 901                         case UDP_ENCAP_ESPINUDP_NON_IKE:
 902                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 903                                 if (optval == UDP_ENCAP_ESPINUDP)
 904                                         up->u_flags |= UF_ESPINUDP;
 905                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
 906                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
 907                                 break;
 908 #endif
 909                         default:
 910                                 error = EINVAL;
 911                                 break;
 912                         }
 913                         INP_WUNLOCK(inp);
 914                         break;
 915                 default:
 916                         INP_WUNLOCK(inp);
 917                         error = ENOPROTOOPT;
 918                         break;
 919                 }
 920                 break;
 921         case SOPT_GET:
 922                 switch (sopt->sopt_name) {
 923 #ifdef IPSEC_NAT_T
 924                 case UDP_ENCAP:
 925                         up = intoudpcb(inp);
 926                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 927                         optval = up->u_flags & UF_ESPINUDP_ALL;
 928                         INP_WUNLOCK(inp);
 929                         error = sooptcopyout(sopt, &optval, sizeof optval);
 930                         break;
 931 #endif
 932                 default:
 933                         INP_WUNLOCK(inp);
 934                         error = ENOPROTOOPT;
 935                         break;
 936                 }
 937                 break;
 938         }
 939         return (error);
 940 }
 941
 942 #ifdef INET
 943 #define UH_WLOCKED      2
 944 #define UH_RLOCKED      1
 945 #define UH_UNLOCKED     0
 946 static int
 947 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
 948     struct mbuf *control, struct thread *td)
 949 {
 950         struct udpiphdr *ui;
 951         int len = m->m_pkthdr.len;
 952         struct in_addr faddr, laddr;
 953         struct cmsghdr *cm;
 954         struct sockaddr_in *sin, src;
 955         int error = 0;
 956         int ipflags;
 957         u_short fport, lport;
 958         int unlock_udbinfo;
 959
 960         /*
 961          * udp_output() may need to temporarily bind or connect the current
 962          * inpcb.  As such, we don't know up front whether we will need the
 963          * pcbinfo lock or not.  Do any work to decide what is needed up
 964          * front before acquiring any locks.
 965          */
 966         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 967                 if (control)
 968                         m_freem(control);
 969                 m_freem(m);
 970                 return (EMSGSIZE);
 971         }
 972
 973         src.sin_family = 0;
 974         INP_RLOCK(inp);
 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                         INP_RUNLOCK(inp);
 982                         m_freem(control);
 983                         m_freem(m);
 984                         return (EINVAL);
 985                 }
 986                 for (; control->m_len > 0;
 987                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 988                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 989                         cm = mtod(control, struct cmsghdr *);
 990                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 991                             || cm->cmsg_len > control->m_len) {
 992                                 error = EINVAL;
 993                                 break;
 994                         }
 995                         if (cm->cmsg_level != IPPROTO_IP)
 996                                 continue;
 997
 998                         switch (cm->cmsg_type) {
 999                         case IP_SENDSRCADDR:
1000                                 if (cm->cmsg_len !=
1001                                     CMSG_LEN(sizeof(struct in_addr))) {
1002                                         error = EINVAL;
1003                                         break;
1004                                 }
1005                                 bzero(&src, sizeof(src));
1006                                 src.sin_family = AF_INET;
1007                                 src.sin_len = sizeof(src);
1008                                 src.sin_port = inp->inp_lport;
1009                                 src.sin_addr =
1010                                     *(struct in_addr *)CMSG_DATA(cm);
1011                                 break;
1012
1013                         default:
1014                                 error = ENOPROTOOPT;
1015                                 break;
1016                         }
1017                         if (error)
1018                                 break;
1019                 }
1020                 m_freem(control);
1021         }
1022         if (error) {
1023                 INP_RUNLOCK(inp);
1024                 m_freem(m);
1025                 return (error);
1026         }
1027
1028         /*
1029          * Depending on whether or not the application has bound or connected
1030          * the socket, we may have to do varying levels of work.  The optimal
1031          * case is for a connected UDP socket, as a global lock isn't
1032          * required at all.
1033          *
1034          * In order to decide which we need, we require stability of the
1035          * inpcb binding, which we ensure by acquiring a read lock on the
1036          * inpcb.  This doesn't strictly follow the lock order, so we play
1037          * the trylock and retry game; note that we may end up with more
1038          * conservative locks than required the second time around, so later
1039          * assertions have to accept that.  Further analysis of the number of
1040          * misses under contention is required.
1041          *
1042          * XXXRW: Check that hash locking update here is correct.
1043          */
1044         sin = (struct sockaddr_in *)addr;
1045         if (sin != NULL &&
1046             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1047                 INP_RUNLOCK(inp);
1048                 INP_WLOCK(inp);
1049                 INP_HASH_WLOCK(&V_udbinfo);
1050                 unlock_udbinfo = UH_WLOCKED;
1051         } else if ((sin != NULL && (
1052             (sin->sin_addr.s_addr == INADDR_ANY) ||
1053             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1054             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1055             (inp->inp_lport == 0))) ||
1056             (src.sin_family == AF_INET)) {
1057                 INP_HASH_RLOCK(&V_udbinfo);
1058                 unlock_udbinfo = UH_RLOCKED;
1059         } else
1060                 unlock_udbinfo = UH_UNLOCKED;
1061
1062         /*
1063          * If the IP_SENDSRCADDR control message was specified, override the
1064          * source address for this datagram.  Its use is invalidated if the
1065          * address thus specified is incomplete or clobbers other inpcbs.
1066          */
1067         laddr = inp->inp_laddr;
1068         lport = inp->inp_lport;
1069         if (src.sin_family == AF_INET) {
1070                 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1071                 if ((lport == 0) ||
1072                     (laddr.s_addr == INADDR_ANY &&
1073                      src.sin_addr.s_addr == INADDR_ANY)) {
1074                         error = EINVAL;
1075                         goto release;
1076                 }
1077                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1078                     &laddr.s_addr, &lport, td->td_ucred);
1079                 if (error)
1080                         goto release;
1081         }
1082
1083         /*
1084          * If a UDP socket has been connected, then a local address/port will
1085          * have been selected and bound.
1086          *
1087          * If a UDP socket has not been connected to, then an explicit
1088          * destination address must be used, in which case a local
1089          * address/port may not have been selected and bound.
1090          */
1091         if (sin != NULL) {
1092                 INP_LOCK_ASSERT(inp);
1093                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1094                         error = EISCONN;
1095                         goto release;
1096                 }
1097
1098                 /*
1099                  * Jail may rewrite the destination address, so let it do
1100                  * that before we use it.
1101                  */
1102                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1103                 if (error)
1104                         goto release;
1105
1106                 /*
1107                  * If a local address or port hasn't yet been selected, or if
1108                  * the destination address needs to be rewritten due to using
1109                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1110                  * to do the heavy lifting.  Once a port is selected, we
1111                  * commit the binding back to the socket; we also commit the
1112                  * binding of the address if in jail.
1113                  *
1114                  * If we already have a valid binding and we're not
1115                  * requesting a destination address rewrite, use a fast path.
1116                  */
1117                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1118                     inp->inp_lport == 0 ||
1119                     sin->sin_addr.s_addr == INADDR_ANY ||
1120                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1121                         INP_HASH_LOCK_ASSERT(&V_udbinfo);
1122                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1123                             &lport, &faddr.s_addr, &fport, NULL,
1124                             td->td_ucred);
1125                         if (error)
1126                                 goto release;
1127
1128                         /*
1129                          * XXXRW: Why not commit the port if the address is
1130                          * !INADDR_ANY?
1131                          */
1132                         /* Commit the local port if newly assigned. */
1133                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1134                             inp->inp_lport == 0) {
1135                                 INP_WLOCK_ASSERT(inp);
1136                                 INP_HASH_WLOCK_ASSERT(&V_udbinfo);
1137                                 /*
1138                                  * Remember addr if jailed, to prevent
1139                                  * rebinding.
1140                                  */
1141                                 if (prison_flag(td->td_ucred, PR_IP4))
1142                                         inp->inp_laddr = laddr;
1143                                 inp->inp_lport = lport;
1144                                 if (in_pcbinshash(inp) != 0) {
1145                                         inp->inp_lport = 0;
1146                                         error = EAGAIN;
1147                                         goto release;
1148                                 }
1149                                 inp->inp_flags |= INP_ANONPORT;
1150                         }
1151                 } else {
1152                         faddr = sin->sin_addr;
1153                         fport = sin->sin_port;
1154                 }
1155         } else {
1156                 INP_LOCK_ASSERT(inp);
1157                 faddr = inp->inp_faddr;
1158                 fport = inp->inp_fport;
1159                 if (faddr.s_addr == INADDR_ANY) {
1160                         error = ENOTCONN;
1161                         goto release;
1162                 }
1163         }
1164
1165         /*
1166          * Calculate data length and get a mbuf for UDP, IP, and possible
1167          * link-layer headers.  Immediate slide the data pointer back forward
1168          * since we won't use that space at this layer.
1169          */
1170         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1171         if (m == NULL) {
1172                 error = ENOBUFS;
1173                 goto release;
1174         }
1175         m->m_data += max_linkhdr;
1176         m->m_len -= max_linkhdr;
1177         m->m_pkthdr.len -= max_linkhdr;
1178
1179         /*
1180          * Fill in mbuf with extended UDP header and addresses and length put
1181          * into network format.
1182          */
1183         ui = mtod(m, struct udpiphdr *);
1184         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1185         ui->ui_pr = IPPROTO_UDP;
1186         ui->ui_src = laddr;
1187         ui->ui_dst = faddr;
1188         ui->ui_sport = lport;
1189         ui->ui_dport = fport;
1190         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1191
1192         /*
1193          * Set the Don't Fragment bit in the IP header.
1194          */
1195         if (inp->inp_flags & INP_DONTFRAG) {
1196                 struct ip *ip;
1197
1198                 ip = (struct ip *)&ui->ui_i;
1199                 ip->ip_off |= IP_DF;
1200         }
1201
1202         ipflags = 0;
1203         if (inp->inp_socket->so_options & SO_DONTROUTE)
1204                 ipflags |= IP_ROUTETOIF;
1205         if (inp->inp_socket->so_options & SO_BROADCAST)
1206                 ipflags |= IP_ALLOWBROADCAST;
1207         if (inp->inp_flags & INP_ONESBCAST)
1208                 ipflags |= IP_SENDONES;
1209
1210 #ifdef MAC
1211         mac_inpcb_create_mbuf(inp, m);
1212 #endif
1213
1214         /*
1215          * Set up checksum and output datagram.
1216          */
1217         if (V_udp_cksum) {
1218                 if (inp->inp_flags & INP_ONESBCAST)
1219                         faddr.s_addr = INADDR_BROADCAST;
1220                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1221                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1222                 m->m_pkthdr.csum_flags = CSUM_UDP;
1223                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1224         } else
1225                 ui->ui_sum = 0;
1226         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1227         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1228         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
1229         UDPSTAT_INC(udps_opackets);
1230
1231         if (unlock_udbinfo == UH_WLOCKED)
1232                 INP_HASH_WUNLOCK(&V_udbinfo);
1233         else if (unlock_udbinfo == UH_RLOCKED)
1234                 INP_HASH_RUNLOCK(&V_udbinfo);
1235         error = ip_output(m, inp->inp_options, NULL, ipflags,
1236             inp->inp_moptions, inp);
1237         if (unlock_udbinfo == UH_WLOCKED)
1238                 INP_WUNLOCK(inp);
1239         else
1240                 INP_RUNLOCK(inp);
1241         return (error);
1242
1243 release:
1244         if (unlock_udbinfo == UH_WLOCKED) {
1245                 INP_HASH_WUNLOCK(&V_udbinfo);
1246                 INP_WUNLOCK(inp);
1247         } else if (unlock_udbinfo == UH_RLOCKED) {
1248                 INP_HASH_RUNLOCK(&V_udbinfo);
1249                 INP_RUNLOCK(inp);
1250         } else
1251                 INP_RUNLOCK(inp);
1252         m_freem(m);
1253         return (error);
1254 }
1255
1256
1257 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1258 /*
1259  * Potentially decap ESP in UDP frame.  Check for an ESP header
1260  * and optional marker; if present, strip the UDP header and
1261  * push the result through IPSec.
1262  *
1263  * Returns mbuf to be processed (potentially re-allocated) or
1264  * NULL if consumed and/or processed.
1265  */
1266 static struct mbuf *
1267 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1268 {
1269         size_t minlen, payload, skip, iphlen;
1270         caddr_t data;
1271         struct udpcb *up;
1272         struct m_tag *tag;
1273         struct udphdr *udphdr;
1274         struct ip *ip;
1275
1276         INP_RLOCK_ASSERT(inp);
1277
1278         /*
1279          * Pull up data so the longest case is contiguous:
1280          *    IP/UDP hdr + non ESP marker + ESP hdr.
1281          */
1282         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1283         if (minlen > m->m_pkthdr.len)
1284                 minlen = m->m_pkthdr.len;
1285         if ((m = m_pullup(m, minlen)) == NULL) {
1286                 V_ipsec4stat.in_inval++;
1287                 return (NULL);          /* Bypass caller processing. */
1288         }
1289         data = mtod(m, caddr_t);        /* Points to ip header. */
1290         payload = m->m_len - off;       /* Size of payload. */
1291
1292         if (payload == 1 && data[off] == '\xff')
1293                 return (m);             /* NB: keepalive packet, no decap. */
1294
1295         up = intoudpcb(inp);
1296         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1297         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1298             ("u_flags 0x%x", up->u_flags));
1299
1300         /*
1301          * Check that the payload is large enough to hold an
1302          * ESP header and compute the amount of data to remove.
1303          *
1304          * NB: the caller has already done a pullup for us.
1305          * XXX can we assume alignment and eliminate bcopys?
1306          */
1307         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1308                 /*
1309                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1310                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1311                  * possible AH mode non-IKE marker+non-ESP marker
1312                  * from draft-ietf-ipsec-udp-encaps-00.txt.
1313                  */
1314                 uint64_t marker;
1315
1316                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1317                         return (m);     /* NB: no decap. */
1318                 bcopy(data + off, &marker, sizeof(uint64_t));
1319                 if (marker != 0)        /* Non-IKE marker. */
1320                         return (m);     /* NB: no decap. */
1321                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1322         } else {
1323                 uint32_t spi;
1324
1325                 if (payload <= sizeof(struct esp)) {
1326                         V_ipsec4stat.in_inval++;
1327                         m_freem(m);
1328                         return (NULL);  /* Discard. */
1329                 }
1330                 bcopy(data + off, &spi, sizeof(uint32_t));
1331                 if (spi == 0)           /* Non-ESP marker. */
1332                         return (m);     /* NB: no decap. */
1333                 skip = sizeof(struct udphdr);
1334         }
1335
1336         /*
1337          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1338          * the UDP ports. This is required if we want to select
1339          * the right SPD for multiple hosts behind same NAT.
1340          *
1341          * NB: ports are maintained in network byte order everywhere
1342          *     in the NAT-T code.
1343          */
1344         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1345                 2 * sizeof(uint16_t), M_NOWAIT);
1346         if (tag == NULL) {
1347                 V_ipsec4stat.in_nomem++;
1348                 m_freem(m);
1349                 return (NULL);          /* Discard. */
1350         }
1351         iphlen = off - sizeof(struct udphdr);
1352         udphdr = (struct udphdr *)(data + iphlen);
1353         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1354         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1355         m_tag_prepend(m, tag);
1356
1357         /*
1358          * Remove the UDP header (and possibly the non ESP marker)
1359          * IP header length is iphlen
1360          * Before:
1361          *   <--- off --->
1362          *   +----+------+-----+
1363          *   | IP |  UDP | ESP |
1364          *   +----+------+-----+
1365          *        <-skip->
1366          * After:
1367          *          +----+-----+
1368          *          | IP | ESP |
1369          *          +----+-----+
1370          *   <-skip->
1371          */
1372         ovbcopy(data, data + skip, iphlen);
1373         m_adj(m, skip);
1374
1375         ip = mtod(m, struct ip *);
1376         ip->ip_len -= skip;
1377         ip->ip_p = IPPROTO_ESP;
1378
1379         /*
1380          * We cannot yet update the cksums so clear any
1381          * h/w cksum flags as they are no longer valid.
1382          */
1383         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1384                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1385
1386         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1387         return (NULL);                  /* NB: consumed, bypass processing. */
1388 }
1389 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1390
1391 static void
1392 udp_abort(struct socket *so)
1393 {
1394         struct inpcb *inp;
1395
1396         inp = sotoinpcb(so);
1397         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1398         INP_WLOCK(inp);
1399         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1400                 INP_HASH_WLOCK(&V_udbinfo);
1401                 in_pcbdisconnect(inp);
1402                 inp->inp_laddr.s_addr = INADDR_ANY;
1403                 INP_HASH_WUNLOCK(&V_udbinfo);
1404                 soisdisconnected(so);
1405         }
1406         INP_WUNLOCK(inp);
1407 }
1408
1409 static int
1410 udp_attach(struct socket *so, int proto, struct thread *td)
1411 {
1412         struct inpcb *inp;
1413         int error;
1414
1415         inp = sotoinpcb(so);
1416         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1417         error = soreserve(so, udp_sendspace, udp_recvspace);
1418         if (error)
1419                 return (error);
1420         INP_INFO_WLOCK(&V_udbinfo);
1421         error = in_pcballoc(so, &V_udbinfo);
1422         if (error) {
1423                 INP_INFO_WUNLOCK(&V_udbinfo);
1424                 return (error);
1425         }
1426
1427         inp = sotoinpcb(so);
1428         inp->inp_vflag |= INP_IPV4;
1429         inp->inp_ip_ttl = V_ip_defttl;
1430
1431         error = udp_newudpcb(inp);
1432         if (error) {
1433                 in_pcbdetach(inp);
1434                 in_pcbfree(inp);
1435                 INP_INFO_WUNLOCK(&V_udbinfo);
1436                 return (error);
1437         }
1438
1439         INP_WUNLOCK(inp);
1440         INP_INFO_WUNLOCK(&V_udbinfo);
1441         return (0);
1442 }
1443 #endif /* INET */
1444
1445 int
1446 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1447 {
1448         struct inpcb *inp;
1449         struct udpcb *up;
1450
1451         KASSERT(so->so_type == SOCK_DGRAM,
1452             ("udp_set_kernel_tunneling: !dgram"));
1453         inp = sotoinpcb(so);
1454         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1455         INP_WLOCK(inp);
1456         up = intoudpcb(inp);
1457         if (up->u_tun_func != NULL) {
1458                 INP_WUNLOCK(inp);
1459                 return (EBUSY);
1460         }
1461         up->u_tun_func = f;
1462         INP_WUNLOCK(inp);
1463         return (0);
1464 }
1465
1466 #ifdef INET
1467 static int
1468 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1469 {
1470         struct inpcb *inp;
1471         int error;
1472
1473         inp = sotoinpcb(so);
1474         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1475         INP_WLOCK(inp);
1476         INP_HASH_WLOCK(&V_udbinfo);
1477         error = in_pcbbind(inp, nam, td->td_ucred);
1478         INP_HASH_WUNLOCK(&V_udbinfo);
1479         INP_WUNLOCK(inp);
1480         return (error);
1481 }
1482
1483 static void
1484 udp_close(struct socket *so)
1485 {
1486         struct inpcb *inp;
1487
1488         inp = sotoinpcb(so);
1489         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1490         INP_WLOCK(inp);
1491         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1492                 INP_HASH_WLOCK(&V_udbinfo);
1493                 in_pcbdisconnect(inp);
1494                 inp->inp_laddr.s_addr = INADDR_ANY;
1495                 INP_HASH_WUNLOCK(&V_udbinfo);
1496                 soisdisconnected(so);
1497         }
1498         INP_WUNLOCK(inp);
1499 }
1500
1501 static int
1502 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1503 {
1504         struct inpcb *inp;
1505         int error;
1506         struct sockaddr_in *sin;
1507
1508         inp = sotoinpcb(so);
1509         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1510         INP_WLOCK(inp);
1511         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1512                 INP_WUNLOCK(inp);
1513                 return (EISCONN);
1514         }
1515         sin = (struct sockaddr_in *)nam;
1516         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1517         if (error != 0) {
1518                 INP_WUNLOCK(inp);
1519                 return (error);
1520         }
1521         INP_HASH_WLOCK(&V_udbinfo);
1522         error = in_pcbconnect(inp, nam, td->td_ucred);
1523         INP_HASH_WUNLOCK(&V_udbinfo);
1524         if (error == 0)
1525                 soisconnected(so);
1526         INP_WUNLOCK(inp);
1527         return (error);
1528 }
1529
1530 static void
1531 udp_detach(struct socket *so)
1532 {
1533         struct inpcb *inp;
1534         struct udpcb *up;
1535
1536         inp = sotoinpcb(so);
1537         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1538         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1539             ("udp_detach: not disconnected"));
1540         INP_INFO_WLOCK(&V_udbinfo);
1541         INP_WLOCK(inp);
1542         up = intoudpcb(inp);
1543         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1544         inp->inp_ppcb = NULL;
1545         in_pcbdetach(inp);
1546         in_pcbfree(inp);
1547         INP_INFO_WUNLOCK(&V_udbinfo);
1548         udp_discardcb(up);
1549 }
1550
1551 static int
1552 udp_disconnect(struct socket *so)
1553 {
1554         struct inpcb *inp;
1555
1556         inp = sotoinpcb(so);
1557         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1558         INP_WLOCK(inp);
1559         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1560                 INP_WUNLOCK(inp);
1561                 return (ENOTCONN);
1562         }
1563         INP_HASH_WLOCK(&V_udbinfo);
1564         in_pcbdisconnect(inp);
1565         inp->inp_laddr.s_addr = INADDR_ANY;
1566         INP_HASH_WUNLOCK(&V_udbinfo);
1567         SOCK_LOCK(so);
1568         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1569         SOCK_UNLOCK(so);
1570         INP_WUNLOCK(inp);
1571         return (0);
1572 }
1573
1574 static int
1575 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1576     struct mbuf *control, struct thread *td)
1577 {
1578         struct inpcb *inp;
1579
1580         inp = sotoinpcb(so);
1581         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1582         return (udp_output(inp, m, addr, control, td));
1583 }
1584 #endif /* INET */
1585
1586 int
1587 udp_shutdown(struct socket *so)
1588 {
1589         struct inpcb *inp;
1590
1591         inp = sotoinpcb(so);
1592         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1593         INP_WLOCK(inp);
1594         socantsendmore(so);
1595         INP_WUNLOCK(inp);
1596         return (0);
1597 }
1598
1599 #ifdef INET
1600 struct pr_usrreqs udp_usrreqs = {
1601         .pru_abort =            udp_abort,
1602         .pru_attach =           udp_attach,
1603         .pru_bind =             udp_bind,
1604         .pru_connect =          udp_connect,
1605         .pru_control =          in_control,
1606         .pru_detach =           udp_detach,
1607         .pru_disconnect =       udp_disconnect,
1608         .pru_peeraddr =         in_getpeeraddr,
1609         .pru_send =             udp_send,
1610         .pru_soreceive =        soreceive_dgram,
1611         .pru_sosend =           sosend_dgram,
1612         .pru_shutdown =         udp_shutdown,
1613         .pru_sockaddr =         in_getsockaddr,
1614         .pru_sosetlabel =       in_pcbsosetlabel,
1615         .pru_close =            udp_close,
1616 };
1617 #endif /* INET */