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_PCPUSTAT_DEFINE(struct udpstat, udpstat);          /* from udp_var.h */
 147 VNET_PCPUSTAT_SYSINIT(udpstat);
 148 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
 149     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 150
 151 #ifdef VIMAGE
 152 VNET_PCPUSTAT_SYSUNINIT(udpstat);
 153 #endif /* VIMAGE */
 154 #ifdef INET
 155 static void     udp_detach(struct socket *so);
 156 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 157                     struct mbuf *, struct thread *);
 158 #endif
 159
 160 #ifdef IPSEC
 161 #ifdef IPSEC_NAT_T
 162 #define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
 163 #ifdef INET
 164 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
 165 #endif
 166 #endif /* IPSEC_NAT_T */
 167 #endif /* IPSEC */
 168
 169 static void
 170 udp_zone_change(void *tag)
 171 {
 172
 173         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 174         uma_zone_set_max(V_udpcb_zone, maxsockets);
 175 }
 176
 177 static int
 178 udp_inpcb_init(void *mem, int size, int flags)
 179 {
 180         struct inpcb *inp;
 181
 182         inp = mem;
 183         INP_LOCK_INIT(inp, "inp", "udpinp");
 184         return (0);
 185 }
 186
 187 void
 188 udp_init(void)
 189 {
 190
 191         in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
 192             "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE,
 193             IPI_HASHFIELDS_2TUPLE);
 194         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
 195             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 196         uma_zone_set_max(V_udpcb_zone, maxsockets);
 197         uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
 198         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 199             EVENTHANDLER_PRI_ANY);
 200 }
 201
 202 /*
 203  * Kernel module interface for updating udpstat.  The argument is an index
 204  * into udpstat treated as an array of u_long.  While this encodes the
 205  * general layout of udpstat into the caller, it doesn't encode its location,
 206  * so that future changes to add, for example, per-CPU stats support won't
 207  * cause binary compatibility problems for kernel modules.
 208  */
 209 void
 210 kmod_udpstat_inc(int statnum)
 211 {
 212
 213         counter_u64_add(VNET(udpstat)[statnum], 1);
 214 }
 215
 216 int
 217 udp_newudpcb(struct inpcb *inp)
 218 {
 219         struct udpcb *up;
 220
 221         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
 222         if (up == NULL)
 223                 return (ENOBUFS);
 224         inp->inp_ppcb = up;
 225         return (0);
 226 }
 227
 228 void
 229 udp_discardcb(struct udpcb *up)
 230 {
 231
 232         uma_zfree(V_udpcb_zone, up);
 233 }
 234
 235 #ifdef VIMAGE
 236 void
 237 udp_destroy(void)
 238 {
 239
 240         in_pcbinfo_destroy(&V_udbinfo);
 241         uma_zdestroy(V_udpcb_zone);
 242 }
 243 #endif
 244
 245 #ifdef INET
 246 /*
 247  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 248  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 249  * contains the source address.  If the socket ends up being an IPv6 socket,
 250  * udp_append() will convert to a sockaddr_in6 before passing the address
 251  * into the socket code.
 252  */
 253 static void
 254 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 255     struct sockaddr_in *udp_in)
 256 {
 257         struct sockaddr *append_sa;
 258         struct socket *so;
 259         struct mbuf *opts = 0;
 260 #ifdef INET6
 261         struct sockaddr_in6 udp_in6;
 262 #endif
 263         struct udpcb *up;
 264
 265         INP_LOCK_ASSERT(inp);
 266
 267         /*
 268          * Engage the tunneling protocol.
 269          */
 270         up = intoudpcb(inp);
 271         if (up->u_tun_func != NULL) {
 272                 (*up->u_tun_func)(n, off, inp);
 273                 return;
 274         }
 275
 276         if (n == NULL)
 277                 return;
 278
 279         off += sizeof(struct udphdr);
 280
 281 #ifdef IPSEC
 282         /* Check AH/ESP integrity. */
 283         if (ipsec4_in_reject(n, inp)) {
 284                 m_freem(n);
 285                 IPSECSTAT_INC(in_polvio);
 286                 return;
 287         }
 288 #ifdef IPSEC_NAT_T
 289         up = intoudpcb(inp);
 290         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
 291         if (up->u_flags & UF_ESPINUDP_ALL) {    /* IPSec UDP encaps. */
 292                 n = udp4_espdecap(inp, n, off);
 293                 if (n == NULL)                          /* Consumed. */
 294                         return;
 295         }
 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 /* MAC */
 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 /* INET6 */
 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 /* INET6 */
 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         uint16_t len, ip_len;
 346         struct ip save_ip;
 347         struct sockaddr_in udp_in;
 348         struct m_tag *fwd_tag;
 349
 350         ifp = m->m_pkthdr.rcvif;
 351         UDPSTAT_INC(udps_ipackets);
 352
 353         /*
 354          * Strip IP options, if any; should skip this, make available to
 355          * user, and use on returned packets, but we don't yet have a way to
 356          * check the checksum with options still present.
 357          */
 358         if (iphlen > sizeof (struct ip)) {
 359                 ip_stripoptions(m);
 360                 iphlen = sizeof(struct ip);
 361         }
 362
 363         /*
 364          * Get IP and UDP header together in first mbuf.
 365          */
 366         ip = mtod(m, struct ip *);
 367         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 368                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 369                         UDPSTAT_INC(udps_hdrops);
 370                         return;
 371                 }
 372                 ip = mtod(m, struct ip *);
 373         }
 374         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 375
 376         /*
 377          * Destination port of 0 is illegal, based on RFC768.
 378          */
 379         if (uh->uh_dport == 0)
 380                 goto badunlocked;
 381
 382         /*
 383          * Construct sockaddr format source address.  Stuff source address
 384          * and datagram in user buffer.
 385          */
 386         bzero(&udp_in, sizeof(udp_in));
 387         udp_in.sin_len = sizeof(udp_in);
 388         udp_in.sin_family = AF_INET;
 389         udp_in.sin_port = uh->uh_sport;
 390         udp_in.sin_addr = ip->ip_src;
 391
 392         /*
 393          * Make mbuf data length reflect UDP length.  If not enough data to
 394          * reflect UDP length, drop.
 395          */
 396         len = ntohs((u_short)uh->uh_ulen);
 397         ip_len = ntohs(ip->ip_len) - iphlen;
 398         if (ip_len != len) {
 399                 if (len > ip_len || len < sizeof(struct udphdr)) {
 400                         UDPSTAT_INC(udps_badlen);
 401                         goto badunlocked;
 402                 }
 403                 m_adj(m, len - ip_len);
 404         }
 405
 406         /*
 407          * Save a copy of the IP header in case we want restore it for
 408          * sending an ICMP error message in response.
 409          */
 410         if (!V_udp_blackhole)
 411                 save_ip = *ip;
 412         else
 413                 memset(&save_ip, 0, sizeof(save_ip));
 414
 415         /*
 416          * Checksum extended UDP header and data.
 417          */
 418         if (uh->uh_sum) {
 419                 u_short uh_sum;
 420
 421                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 422                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 423                                 uh_sum = m->m_pkthdr.csum_data;
 424                         else
 425                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 426                                     ip->ip_dst.s_addr, htonl((u_short)len +
 427                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 428                         uh_sum ^= 0xffff;
 429                 } else {
 430                         char b[9];
 431
 432                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 433                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 434                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 435                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 436                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 437                 }
 438                 if (uh_sum) {
 439                         UDPSTAT_INC(udps_badsum);
 440                         m_freem(m);
 441                         return;
 442                 }
 443         } else
 444                 UDPSTAT_INC(udps_nosum);
 445
 446         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 447             in_broadcast(ip->ip_dst, ifp)) {
 448                 struct inpcb *last;
 449                 struct ip_moptions *imo;
 450
 451                 INP_INFO_RLOCK(&V_udbinfo);
 452                 last = NULL;
 453                 LIST_FOREACH(inp, &V_udb, inp_list) {
 454                         if (inp->inp_lport != uh->uh_dport)
 455                                 continue;
 456 #ifdef INET6
 457                         if ((inp->inp_vflag & INP_IPV4) == 0)
 458                                 continue;
 459 #endif
 460                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 461                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 462                                 continue;
 463                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 464                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 465                                 continue;
 466                         if (inp->inp_fport != 0 &&
 467                             inp->inp_fport != uh->uh_sport)
 468                                 continue;
 469
 470                         INP_RLOCK(inp);
 471
 472                         /*
 473                          * XXXRW: Because we weren't holding either the inpcb
 474                          * or the hash lock when we checked for a match
 475                          * before, we should probably recheck now that the
 476                          * inpcb lock is held.
 477                          */
 478
 479                         /*
 480                          * Handle socket delivery policy for any-source
 481                          * and source-specific multicast. [RFC3678]
 482                          */
 483                         imo = inp->inp_moptions;
 484                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 485                                 struct sockaddr_in       group;
 486                                 int                      blocked;
 487                                 if (imo == NULL) {
 488                                         INP_RUNLOCK(inp);
 489                                         continue;
 490                                 }
 491                                 bzero(&group, sizeof(struct sockaddr_in));
 492                                 group.sin_len = sizeof(struct sockaddr_in);
 493                                 group.sin_family = AF_INET;
 494                                 group.sin_addr = ip->ip_dst;
 495
 496                                 blocked = imo_multi_filter(imo, ifp,
 497                                         (struct sockaddr *)&group,
 498                                         (struct sockaddr *)&udp_in);
 499                                 if (blocked != MCAST_PASS) {
 500                                         if (blocked == MCAST_NOTGMEMBER)
 501                                                 IPSTAT_INC(ips_notmember);
 502                                         if (blocked == MCAST_NOTSMEMBER ||
 503                                             blocked == MCAST_MUTED)
 504                                                 UDPSTAT_INC(udps_filtermcast);
 505                                         INP_RUNLOCK(inp);
 506                                         continue;
 507                                 }
 508                         }
 509                         if (last != NULL) {
 510                                 struct mbuf *n;
 511
 512                                 n = m_copy(m, 0, M_COPYALL);
 513                                 udp_append(last, ip, n, iphlen, &udp_in);
 514                                 INP_RUNLOCK(last);
 515                         }
 516                         last = inp;
 517                         /*
 518                          * Don't look for additional matches if this one does
 519                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 520                          * socket options set.  This heuristic avoids
 521                          * searching through all pcbs in the common case of a
 522                          * non-shared port.  It assumes that an application
 523                          * will never clear these options after setting them.
 524                          */
 525                         if ((last->inp_socket->so_options &
 526                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 527                                 break;
 528                 }
 529
 530                 if (last == NULL) {
 531                         /*
 532                          * No matching pcb found; discard datagram.  (No need
 533                          * to send an ICMP Port Unreachable for a broadcast
 534                          * or multicast datgram.)
 535                          */
 536                         UDPSTAT_INC(udps_noportbcast);
 537                         if (inp)
 538                                 INP_RUNLOCK(inp);
 539                         INP_INFO_RUNLOCK(&V_udbinfo);
 540                         goto badunlocked;
 541                 }
 542                 udp_append(last, ip, m, iphlen, &udp_in);
 543                 INP_RUNLOCK(last);
 544                 INP_INFO_RUNLOCK(&V_udbinfo);
 545                 return;
 546         }
 547
 548         /*
 549          * Locate pcb for datagram.
 550          */
 551
 552         /*
 553          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 554          */
 555         if ((m->m_flags & M_IP_NEXTHOP) &&
 556             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 557                 struct sockaddr_in *next_hop;
 558
 559                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 560
 561                 /*
 562                  * Transparently forwarded. Pretend to be the destination.
 563                  * Already got one like this?
 564                  */
 565                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 566                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
 567                 if (!inp) {
 568                         /*
 569                          * It's new.  Try to find the ambushing socket.
 570                          * Because we've rewritten the destination address,
 571                          * any hardware-generated hash is ignored.
 572                          */
 573                         inp = in_pcblookup(&V_udbinfo, ip->ip_src,
 574                             uh->uh_sport, next_hop->sin_addr,
 575                             next_hop->sin_port ? htons(next_hop->sin_port) :
 576                             uh->uh_dport, INPLOOKUP_WILDCARD |
 577                             INPLOOKUP_RLOCKPCB, ifp);
 578                 }
 579                 /* Remove the tag from the packet. We don't need it anymore. */
 580                 m_tag_delete(m, fwd_tag);
 581                 m->m_flags &= ~M_IP_NEXTHOP;
 582         } else
 583                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 584                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
 585                     INPLOOKUP_RLOCKPCB, ifp, m);
 586         if (inp == NULL) {
 587                 if (udp_log_in_vain) {
 588                         char buf[4*sizeof "123"];
 589
 590                         strcpy(buf, inet_ntoa(ip->ip_dst));
 591                         log(LOG_INFO,
 592                             "Connection attempt to UDP %s:%d from %s:%d\n",
 593                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 594                             ntohs(uh->uh_sport));
 595                 }
 596                 UDPSTAT_INC(udps_noport);
 597                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 598                         UDPSTAT_INC(udps_noportbcast);
 599                         goto badunlocked;
 600                 }
 601                 if (V_udp_blackhole)
 602                         goto badunlocked;
 603                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 604                         goto badunlocked;
 605                 *ip = save_ip;
 606                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 607                 return;
 608         }
 609
 610         /*
 611          * Check the minimum TTL for socket.
 612          */
 613         INP_RLOCK_ASSERT(inp);
 614         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 615                 INP_RUNLOCK(inp);
 616                 m_freem(m);
 617                 return;
 618         }
 619         udp_append(inp, ip, m, iphlen, &udp_in);
 620         INP_RUNLOCK(inp);
 621         return;
 622
 623 badunlocked:
 624         m_freem(m);
 625 }
 626 #endif /* INET */
 627
 628 /*
 629  * Notify a udp user of an asynchronous error; just wake up so that they can
 630  * collect error status.
 631  */
 632 struct inpcb *
 633 udp_notify(struct inpcb *inp, int errno)
 634 {
 635
 636         /*
 637          * While udp_ctlinput() always calls udp_notify() with a read lock
 638          * when invoking it directly, in_pcbnotifyall() currently uses write
 639          * locks due to sharing code with TCP.  For now, accept either a read
 640          * or a write lock, but a read lock is sufficient.
 641          */
 642         INP_LOCK_ASSERT(inp);
 643
 644         inp->inp_socket->so_error = errno;
 645         sorwakeup(inp->inp_socket);
 646         sowwakeup(inp->inp_socket);
 647         return (inp);
 648 }
 649
 650 #ifdef INET
 651 void
 652 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 653 {
 654         struct ip *ip = vip;
 655         struct udphdr *uh;
 656         struct in_addr faddr;
 657         struct inpcb *inp;
 658
 659         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 660         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 661                 return;
 662
 663         /*
 664          * Redirects don't need to be handled up here.
 665          */
 666         if (PRC_IS_REDIRECT(cmd))
 667                 return;
 668
 669         /*
 670          * Hostdead is ugly because it goes linearly through all PCBs.
 671          *
 672          * XXX: We never get this from ICMP, otherwise it makes an excellent
 673          * DoS attack on machines with many connections.
 674          */
 675         if (cmd == PRC_HOSTDEAD)
 676                 ip = NULL;
 677         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 678                 return;
 679         if (ip != NULL) {
 680                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 681                 inp = in_pcblookup(&V_udbinfo, faddr, uh->uh_dport,
 682                     ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
 683                 if (inp != NULL) {
 684                         INP_RLOCK_ASSERT(inp);
 685                         if (inp->inp_socket != NULL) {
 686                                 udp_notify(inp, inetctlerrmap[cmd]);
 687                         }
 688                         INP_RUNLOCK(inp);
 689                 }
 690         } else
 691                 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
 692                     udp_notify);
 693 }
 694 #endif /* INET */
 695
 696 static int
 697 udp_pcblist(SYSCTL_HANDLER_ARGS)
 698 {
 699         int error, i, n;
 700         struct inpcb *inp, **inp_list;
 701         inp_gen_t gencnt;
 702         struct xinpgen xig;
 703
 704         /*
 705          * The process of preparing the PCB list is too time-consuming and
 706          * resource-intensive to repeat twice on every request.
 707          */
 708         if (req->oldptr == 0) {
 709                 n = V_udbinfo.ipi_count;
 710                 n += imax(n / 8, 10);
 711                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 712                 return (0);
 713         }
 714
 715         if (req->newptr != 0)
 716                 return (EPERM);
 717
 718         /*
 719          * OK, now we're committed to doing something.
 720          */
 721         INP_INFO_RLOCK(&V_udbinfo);
 722         gencnt = V_udbinfo.ipi_gencnt;
 723         n = V_udbinfo.ipi_count;
 724         INP_INFO_RUNLOCK(&V_udbinfo);
 725
 726         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 727                 + n * sizeof(struct xinpcb));
 728         if (error != 0)
 729                 return (error);
 730
 731         xig.xig_len = sizeof xig;
 732         xig.xig_count = n;
 733         xig.xig_gen = gencnt;
 734         xig.xig_sogen = so_gencnt;
 735         error = SYSCTL_OUT(req, &xig, sizeof xig);
 736         if (error)
 737                 return (error);
 738
 739         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 740         if (inp_list == 0)
 741                 return (ENOMEM);
 742
 743         INP_INFO_RLOCK(&V_udbinfo);
 744         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
 745              inp = LIST_NEXT(inp, inp_list)) {
 746                 INP_WLOCK(inp);
 747                 if (inp->inp_gencnt <= gencnt &&
 748                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
 749                         in_pcbref(inp);
 750                         inp_list[i++] = inp;
 751                 }
 752                 INP_WUNLOCK(inp);
 753         }
 754         INP_INFO_RUNLOCK(&V_udbinfo);
 755         n = i;
 756
 757         error = 0;
 758         for (i = 0; i < n; i++) {
 759                 inp = inp_list[i];
 760                 INP_RLOCK(inp);
 761                 if (inp->inp_gencnt <= gencnt) {
 762                         struct xinpcb xi;
 763
 764                         bzero(&xi, sizeof(xi));
 765                         xi.xi_len = sizeof xi;
 766                         /* XXX should avoid extra copy */
 767                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 768                         if (inp->inp_socket)
 769                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 770                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 771                         INP_RUNLOCK(inp);
 772                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 773                 } else
 774                         INP_RUNLOCK(inp);
 775         }
 776         INP_INFO_WLOCK(&V_udbinfo);
 777         for (i = 0; i < n; i++) {
 778                 inp = inp_list[i];
 779                 INP_RLOCK(inp);
 780                 if (!in_pcbrele_rlocked(inp))
 781                         INP_RUNLOCK(inp);
 782         }
 783         INP_INFO_WUNLOCK(&V_udbinfo);
 784
 785         if (!error) {
 786                 /*
 787                  * Give the user an updated idea of our state.  If the
 788                  * generation differs from what we told her before, she knows
 789                  * that something happened while we were processing this
 790                  * request, and it might be necessary to retry.
 791                  */
 792                 INP_INFO_RLOCK(&V_udbinfo);
 793                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 794                 xig.xig_sogen = so_gencnt;
 795                 xig.xig_count = V_udbinfo.ipi_count;
 796                 INP_INFO_RUNLOCK(&V_udbinfo);
 797                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 798         }
 799         free(inp_list, M_TEMP);
 800         return (error);
 801 }
 802
 803 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
 804     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
 805     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 806
 807 #ifdef INET
 808 static int
 809 udp_getcred(SYSCTL_HANDLER_ARGS)
 810 {
 811         struct xucred xuc;
 812         struct sockaddr_in addrs[2];
 813         struct inpcb *inp;
 814         int error;
 815
 816         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 817         if (error)
 818                 return (error);
 819         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 820         if (error)
 821                 return (error);
 822         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 823             addrs[0].sin_addr, addrs[0].sin_port,
 824             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 825         if (inp != NULL) {
 826                 INP_RLOCK_ASSERT(inp);
 827                 if (inp->inp_socket == NULL)
 828                         error = ENOENT;
 829                 if (error == 0)
 830                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 831                 if (error == 0)
 832                         cru2x(inp->inp_cred, &xuc);
 833                 INP_RUNLOCK(inp);
 834         } else
 835                 error = ENOENT;
 836         if (error == 0)
 837                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 838         return (error);
 839 }
 840
 841 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 842     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 843     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 844 #endif /* INET */
 845
 846 int
 847 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 848 {
 849         int error = 0, optval;
 850         struct inpcb *inp;
 851 #ifdef IPSEC_NAT_T
 852         struct udpcb *up;
 853 #endif
 854
 855         inp = sotoinpcb(so);
 856         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 857         INP_WLOCK(inp);
 858         if (sopt->sopt_level != IPPROTO_UDP) {
 859 #ifdef INET6
 860                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 861                         INP_WUNLOCK(inp);
 862                         error = ip6_ctloutput(so, sopt);
 863                 }
 864 #endif
 865 #if defined(INET) && defined(INET6)
 866                 else
 867 #endif
 868 #ifdef INET
 869                 {
 870                         INP_WUNLOCK(inp);
 871                         error = ip_ctloutput(so, sopt);
 872                 }
 873 #endif
 874                 return (error);
 875         }
 876
 877         switch (sopt->sopt_dir) {
 878         case SOPT_SET:
 879                 switch (sopt->sopt_name) {
 880                 case UDP_ENCAP:
 881                         INP_WUNLOCK(inp);
 882                         error = sooptcopyin(sopt, &optval, sizeof optval,
 883                                             sizeof optval);
 884                         if (error)
 885                                 break;
 886                         inp = sotoinpcb(so);
 887                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 888                         INP_WLOCK(inp);
 889 #ifdef IPSEC_NAT_T
 890                         up = intoudpcb(inp);
 891                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 892 #endif
 893                         switch (optval) {
 894                         case 0:
 895                                 /* Clear all UDP encap. */
 896 #ifdef IPSEC_NAT_T
 897                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 898 #endif
 899                                 break;
 900 #ifdef IPSEC_NAT_T
 901                         case UDP_ENCAP_ESPINUDP:
 902                         case UDP_ENCAP_ESPINUDP_NON_IKE:
 903                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 904                                 if (optval == UDP_ENCAP_ESPINUDP)
 905                                         up->u_flags |= UF_ESPINUDP;
 906                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
 907                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
 908                                 break;
 909 #endif
 910                         default:
 911                                 error = EINVAL;
 912                                 break;
 913                         }
 914                         INP_WUNLOCK(inp);
 915                         break;
 916                 default:
 917                         INP_WUNLOCK(inp);
 918                         error = ENOPROTOOPT;
 919                         break;
 920                 }
 921                 break;
 922         case SOPT_GET:
 923                 switch (sopt->sopt_name) {
 924 #ifdef IPSEC_NAT_T
 925                 case UDP_ENCAP:
 926                         up = intoudpcb(inp);
 927                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 928                         optval = up->u_flags & UF_ESPINUDP_ALL;
 929                         INP_WUNLOCK(inp);
 930                         error = sooptcopyout(sopt, &optval, sizeof optval);
 931                         break;
 932 #endif
 933                 default:
 934                         INP_WUNLOCK(inp);
 935                         error = ENOPROTOOPT;
 936                         break;
 937                 }
 938                 break;
 939         }
 940         return (error);
 941 }
 942
 943 #ifdef INET
 944 #define UH_WLOCKED      2
 945 #define UH_RLOCKED      1
 946 #define UH_UNLOCKED     0
 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         u_char tos;
 961
 962         /*
 963          * udp_output() may need to temporarily bind or connect the current
 964          * inpcb.  As such, we don't know up front whether we will need the
 965          * pcbinfo lock or not.  Do any work to decide what is needed up
 966          * front before acquiring any locks.
 967          */
 968         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 969                 if (control)
 970                         m_freem(control);
 971                 m_freem(m);
 972                 return (EMSGSIZE);
 973         }
 974
 975         src.sin_family = 0;
 976         INP_RLOCK(inp);
 977         tos = inp->inp_ip_tos;
 978         if (control != NULL) {
 979                 /*
 980                  * XXX: Currently, we assume all the optional information is
 981                  * stored in a single mbuf.
 982                  */
 983                 if (control->m_next) {
 984                         INP_RUNLOCK(inp);
 985                         m_freem(control);
 986                         m_freem(m);
 987                         return (EINVAL);
 988                 }
 989                 for (; control->m_len > 0;
 990                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 991                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 992                         cm = mtod(control, struct cmsghdr *);
 993                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 994                             || cm->cmsg_len > control->m_len) {
 995                                 error = EINVAL;
 996                                 break;
 997                         }
 998                         if (cm->cmsg_level != IPPROTO_IP)
 999                                 continue;
1000
1001                         switch (cm->cmsg_type) {
1002                         case IP_SENDSRCADDR:
1003                                 if (cm->cmsg_len !=
1004                                     CMSG_LEN(sizeof(struct in_addr))) {
1005                                         error = EINVAL;
1006                                         break;
1007                                 }
1008                                 bzero(&src, sizeof(src));
1009                                 src.sin_family = AF_INET;
1010                                 src.sin_len = sizeof(src);
1011                                 src.sin_port = inp->inp_lport;
1012                                 src.sin_addr =
1013                                     *(struct in_addr *)CMSG_DATA(cm);
1014                                 break;
1015
1016                         case IP_TOS:
1017                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1018                                         error = EINVAL;
1019                                         break;
1020                                 }
1021                                 tos = *(u_char *)CMSG_DATA(cm);
1022                                 break;
1023
1024                         default:
1025                                 error = ENOPROTOOPT;
1026                                 break;
1027                         }
1028                         if (error)
1029                                 break;
1030                 }
1031                 m_freem(control);
1032         }
1033         if (error) {
1034                 INP_RUNLOCK(inp);
1035                 m_freem(m);
1036                 return (error);
1037         }
1038
1039         /*
1040          * Depending on whether or not the application has bound or connected
1041          * the socket, we may have to do varying levels of work.  The optimal
1042          * case is for a connected UDP socket, as a global lock isn't
1043          * required at all.
1044          *
1045          * In order to decide which we need, we require stability of the
1046          * inpcb binding, which we ensure by acquiring a read lock on the
1047          * inpcb.  This doesn't strictly follow the lock order, so we play
1048          * the trylock and retry game; note that we may end up with more
1049          * conservative locks than required the second time around, so later
1050          * assertions have to accept that.  Further analysis of the number of
1051          * misses under contention is required.
1052          *
1053          * XXXRW: Check that hash locking update here is correct.
1054          */
1055         sin = (struct sockaddr_in *)addr;
1056         if (sin != NULL &&
1057             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1058                 INP_RUNLOCK(inp);
1059                 INP_WLOCK(inp);
1060                 INP_HASH_WLOCK(&V_udbinfo);
1061                 unlock_udbinfo = UH_WLOCKED;
1062         } else if ((sin != NULL && (
1063             (sin->sin_addr.s_addr == INADDR_ANY) ||
1064             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1065             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1066             (inp->inp_lport == 0))) ||
1067             (src.sin_family == AF_INET)) {
1068                 INP_HASH_RLOCK(&V_udbinfo);
1069                 unlock_udbinfo = UH_RLOCKED;
1070         } else
1071                 unlock_udbinfo = UH_UNLOCKED;
1072
1073         /*
1074          * If the IP_SENDSRCADDR control message was specified, override the
1075          * source address for this datagram.  Its use is invalidated if the
1076          * address thus specified is incomplete or clobbers other inpcbs.
1077          */
1078         laddr = inp->inp_laddr;
1079         lport = inp->inp_lport;
1080         if (src.sin_family == AF_INET) {
1081                 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1082                 if ((lport == 0) ||
1083                     (laddr.s_addr == INADDR_ANY &&
1084                      src.sin_addr.s_addr == INADDR_ANY)) {
1085                         error = EINVAL;
1086                         goto release;
1087                 }
1088                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1089                     &laddr.s_addr, &lport, td->td_ucred);
1090                 if (error)
1091                         goto release;
1092         }
1093
1094         /*
1095          * If a UDP socket has been connected, then a local address/port will
1096          * have been selected and bound.
1097          *
1098          * If a UDP socket has not been connected to, then an explicit
1099          * destination address must be used, in which case a local
1100          * address/port may not have been selected and bound.
1101          */
1102         if (sin != NULL) {
1103                 INP_LOCK_ASSERT(inp);
1104                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1105                         error = EISCONN;
1106                         goto release;
1107                 }
1108
1109                 /*
1110                  * Jail may rewrite the destination address, so let it do
1111                  * that before we use it.
1112                  */
1113                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1114                 if (error)
1115                         goto release;
1116
1117                 /*
1118                  * If a local address or port hasn't yet been selected, or if
1119                  * the destination address needs to be rewritten due to using
1120                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1121                  * to do the heavy lifting.  Once a port is selected, we
1122                  * commit the binding back to the socket; we also commit the
1123                  * binding of the address if in jail.
1124                  *
1125                  * If we already have a valid binding and we're not
1126                  * requesting a destination address rewrite, use a fast path.
1127                  */
1128                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1129                     inp->inp_lport == 0 ||
1130                     sin->sin_addr.s_addr == INADDR_ANY ||
1131                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1132                         INP_HASH_LOCK_ASSERT(&V_udbinfo);
1133                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1134                             &lport, &faddr.s_addr, &fport, NULL,
1135                             td->td_ucred);
1136                         if (error)
1137                                 goto release;
1138
1139                         /*
1140                          * XXXRW: Why not commit the port if the address is
1141                          * !INADDR_ANY?
1142                          */
1143                         /* Commit the local port if newly assigned. */
1144                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1145                             inp->inp_lport == 0) {
1146                                 INP_WLOCK_ASSERT(inp);
1147                                 INP_HASH_WLOCK_ASSERT(&V_udbinfo);
1148                                 /*
1149                                  * Remember addr if jailed, to prevent
1150                                  * rebinding.
1151                                  */
1152                                 if (prison_flag(td->td_ucred, PR_IP4))
1153                                         inp->inp_laddr = laddr;
1154                                 inp->inp_lport = lport;
1155                                 if (in_pcbinshash(inp) != 0) {
1156                                         inp->inp_lport = 0;
1157                                         error = EAGAIN;
1158                                         goto release;
1159                                 }
1160                                 inp->inp_flags |= INP_ANONPORT;
1161                         }
1162                 } else {
1163                         faddr = sin->sin_addr;
1164                         fport = sin->sin_port;
1165                 }
1166         } else {
1167                 INP_LOCK_ASSERT(inp);
1168                 faddr = inp->inp_faddr;
1169                 fport = inp->inp_fport;
1170                 if (faddr.s_addr == INADDR_ANY) {
1171                         error = ENOTCONN;
1172                         goto release;
1173                 }
1174         }
1175
1176         /*
1177          * Calculate data length and get a mbuf for UDP, IP, and possible
1178          * link-layer headers.  Immediate slide the data pointer back forward
1179          * since we won't use that space at this layer.
1180          */
1181         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1182         if (m == NULL) {
1183                 error = ENOBUFS;
1184                 goto release;
1185         }
1186         m->m_data += max_linkhdr;
1187         m->m_len -= max_linkhdr;
1188         m->m_pkthdr.len -= max_linkhdr;
1189
1190         /*
1191          * Fill in mbuf with extended UDP header and addresses and length put
1192          * into network format.
1193          */
1194         ui = mtod(m, struct udpiphdr *);
1195         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1196         ui->ui_pr = IPPROTO_UDP;
1197         ui->ui_src = laddr;
1198         ui->ui_dst = faddr;
1199         ui->ui_sport = lport;
1200         ui->ui_dport = fport;
1201         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1202
1203         /*
1204          * Set the Don't Fragment bit in the IP header.
1205          */
1206         if (inp->inp_flags & INP_DONTFRAG) {
1207                 struct ip *ip;
1208
1209                 ip = (struct ip *)&ui->ui_i;
1210                 ip->ip_off |= htons(IP_DF);
1211         }
1212
1213         ipflags = 0;
1214         if (inp->inp_socket->so_options & SO_DONTROUTE)
1215                 ipflags |= IP_ROUTETOIF;
1216         if (inp->inp_socket->so_options & SO_BROADCAST)
1217                 ipflags |= IP_ALLOWBROADCAST;
1218         if (inp->inp_flags & INP_ONESBCAST)
1219                 ipflags |= IP_SENDONES;
1220
1221 #ifdef MAC
1222         mac_inpcb_create_mbuf(inp, m);
1223 #endif
1224
1225         /*
1226          * Set up checksum and output datagram.
1227          */
1228         if (V_udp_cksum) {
1229                 if (inp->inp_flags & INP_ONESBCAST)
1230                         faddr.s_addr = INADDR_BROADCAST;
1231                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1232                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1233                 m->m_pkthdr.csum_flags = CSUM_UDP;
1234                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1235         } else
1236                 ui->ui_sum = 0;
1237         ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1238         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1239         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1240         UDPSTAT_INC(udps_opackets);
1241
1242         if (unlock_udbinfo == UH_WLOCKED)
1243                 INP_HASH_WUNLOCK(&V_udbinfo);
1244         else if (unlock_udbinfo == UH_RLOCKED)
1245                 INP_HASH_RUNLOCK(&V_udbinfo);
1246         error = ip_output(m, inp->inp_options, NULL, ipflags,
1247             inp->inp_moptions, inp);
1248         if (unlock_udbinfo == UH_WLOCKED)
1249                 INP_WUNLOCK(inp);
1250         else
1251                 INP_RUNLOCK(inp);
1252         return (error);
1253
1254 release:
1255         if (unlock_udbinfo == UH_WLOCKED) {
1256                 INP_HASH_WUNLOCK(&V_udbinfo);
1257                 INP_WUNLOCK(inp);
1258         } else if (unlock_udbinfo == UH_RLOCKED) {
1259                 INP_HASH_RUNLOCK(&V_udbinfo);
1260                 INP_RUNLOCK(inp);
1261         } else
1262                 INP_RUNLOCK(inp);
1263         m_freem(m);
1264         return (error);
1265 }
1266
1267
1268 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1269 /*
1270  * Potentially decap ESP in UDP frame.  Check for an ESP header
1271  * and optional marker; if present, strip the UDP header and
1272  * push the result through IPSec.
1273  *
1274  * Returns mbuf to be processed (potentially re-allocated) or
1275  * NULL if consumed and/or processed.
1276  */
1277 static struct mbuf *
1278 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1279 {
1280         size_t minlen, payload, skip, iphlen;
1281         caddr_t data;
1282         struct udpcb *up;
1283         struct m_tag *tag;
1284         struct udphdr *udphdr;
1285         struct ip *ip;
1286
1287         INP_RLOCK_ASSERT(inp);
1288
1289         /*
1290          * Pull up data so the longest case is contiguous:
1291          *    IP/UDP hdr + non ESP marker + ESP hdr.
1292          */
1293         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1294         if (minlen > m->m_pkthdr.len)
1295                 minlen = m->m_pkthdr.len;
1296         if ((m = m_pullup(m, minlen)) == NULL) {
1297                 IPSECSTAT_INC(in_inval);
1298                 return (NULL);          /* Bypass caller processing. */
1299         }
1300         data = mtod(m, caddr_t);        /* Points to ip header. */
1301         payload = m->m_len - off;       /* Size of payload. */
1302
1303         if (payload == 1 && data[off] == '\xff')
1304                 return (m);             /* NB: keepalive packet, no decap. */
1305
1306         up = intoudpcb(inp);
1307         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1308         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1309             ("u_flags 0x%x", up->u_flags));
1310
1311         /*
1312          * Check that the payload is large enough to hold an
1313          * ESP header and compute the amount of data to remove.
1314          *
1315          * NB: the caller has already done a pullup for us.
1316          * XXX can we assume alignment and eliminate bcopys?
1317          */
1318         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1319                 /*
1320                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1321                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1322                  * possible AH mode non-IKE marker+non-ESP marker
1323                  * from draft-ietf-ipsec-udp-encaps-00.txt.
1324                  */
1325                 uint64_t marker;
1326
1327                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1328                         return (m);     /* NB: no decap. */
1329                 bcopy(data + off, &marker, sizeof(uint64_t));
1330                 if (marker != 0)        /* Non-IKE marker. */
1331                         return (m);     /* NB: no decap. */
1332                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1333         } else {
1334                 uint32_t spi;
1335
1336                 if (payload <= sizeof(struct esp)) {
1337                         IPSECSTAT_INC(in_inval);
1338                         m_freem(m);
1339                         return (NULL);  /* Discard. */
1340                 }
1341                 bcopy(data + off, &spi, sizeof(uint32_t));
1342                 if (spi == 0)           /* Non-ESP marker. */
1343                         return (m);     /* NB: no decap. */
1344                 skip = sizeof(struct udphdr);
1345         }
1346
1347         /*
1348          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1349          * the UDP ports. This is required if we want to select
1350          * the right SPD for multiple hosts behind same NAT.
1351          *
1352          * NB: ports are maintained in network byte order everywhere
1353          *     in the NAT-T code.
1354          */
1355         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1356                 2 * sizeof(uint16_t), M_NOWAIT);
1357         if (tag == NULL) {
1358                 IPSECSTAT_INC(in_nomem);
1359                 m_freem(m);
1360                 return (NULL);          /* Discard. */
1361         }
1362         iphlen = off - sizeof(struct udphdr);
1363         udphdr = (struct udphdr *)(data + iphlen);
1364         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1365         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1366         m_tag_prepend(m, tag);
1367
1368         /*
1369          * Remove the UDP header (and possibly the non ESP marker)
1370          * IP header length is iphlen
1371          * Before:
1372          *   <--- off --->
1373          *   +----+------+-----+
1374          *   | IP |  UDP | ESP |
1375          *   +----+------+-----+
1376          *        <-skip->
1377          * After:
1378          *          +----+-----+
1379          *          | IP | ESP |
1380          *          +----+-----+
1381          *   <-skip->
1382          */
1383         ovbcopy(data, data + skip, iphlen);
1384         m_adj(m, skip);
1385
1386         ip = mtod(m, struct ip *);
1387         ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1388         ip->ip_p = IPPROTO_ESP;
1389
1390         /*
1391          * We cannot yet update the cksums so clear any
1392          * h/w cksum flags as they are no longer valid.
1393          */
1394         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1395                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1396
1397         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1398         return (NULL);                  /* NB: consumed, bypass processing. */
1399 }
1400 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1401
1402 static void
1403 udp_abort(struct socket *so)
1404 {
1405         struct inpcb *inp;
1406
1407         inp = sotoinpcb(so);
1408         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1409         INP_WLOCK(inp);
1410         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1411                 INP_HASH_WLOCK(&V_udbinfo);
1412                 in_pcbdisconnect(inp);
1413                 inp->inp_laddr.s_addr = INADDR_ANY;
1414                 INP_HASH_WUNLOCK(&V_udbinfo);
1415                 soisdisconnected(so);
1416         }
1417         INP_WUNLOCK(inp);
1418 }
1419
1420 static int
1421 udp_attach(struct socket *so, int proto, struct thread *td)
1422 {
1423         struct inpcb *inp;
1424         int error;
1425
1426         inp = sotoinpcb(so);
1427         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1428         error = soreserve(so, udp_sendspace, udp_recvspace);
1429         if (error)
1430                 return (error);
1431         INP_INFO_WLOCK(&V_udbinfo);
1432         error = in_pcballoc(so, &V_udbinfo);
1433         if (error) {
1434                 INP_INFO_WUNLOCK(&V_udbinfo);
1435                 return (error);
1436         }
1437
1438         inp = sotoinpcb(so);
1439         inp->inp_vflag |= INP_IPV4;
1440         inp->inp_ip_ttl = V_ip_defttl;
1441
1442         error = udp_newudpcb(inp);
1443         if (error) {
1444                 in_pcbdetach(inp);
1445                 in_pcbfree(inp);
1446                 INP_INFO_WUNLOCK(&V_udbinfo);
1447                 return (error);
1448         }
1449
1450         INP_WUNLOCK(inp);
1451         INP_INFO_WUNLOCK(&V_udbinfo);
1452         return (0);
1453 }
1454 #endif /* INET */
1455
1456 int
1457 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1458 {
1459         struct inpcb *inp;
1460         struct udpcb *up;
1461
1462         KASSERT(so->so_type == SOCK_DGRAM,
1463             ("udp_set_kernel_tunneling: !dgram"));
1464         inp = sotoinpcb(so);
1465         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1466         INP_WLOCK(inp);
1467         up = intoudpcb(inp);
1468         if (up->u_tun_func != NULL) {
1469                 INP_WUNLOCK(inp);
1470                 return (EBUSY);
1471         }
1472         up->u_tun_func = f;
1473         INP_WUNLOCK(inp);
1474         return (0);
1475 }
1476
1477 #ifdef INET
1478 static int
1479 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1480 {
1481         struct inpcb *inp;
1482         int error;
1483
1484         inp = sotoinpcb(so);
1485         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1486         INP_WLOCK(inp);
1487         INP_HASH_WLOCK(&V_udbinfo);
1488         error = in_pcbbind(inp, nam, td->td_ucred);
1489         INP_HASH_WUNLOCK(&V_udbinfo);
1490         INP_WUNLOCK(inp);
1491         return (error);
1492 }
1493
1494 static void
1495 udp_close(struct socket *so)
1496 {
1497         struct inpcb *inp;
1498
1499         inp = sotoinpcb(so);
1500         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1501         INP_WLOCK(inp);
1502         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1503                 INP_HASH_WLOCK(&V_udbinfo);
1504                 in_pcbdisconnect(inp);
1505                 inp->inp_laddr.s_addr = INADDR_ANY;
1506                 INP_HASH_WUNLOCK(&V_udbinfo);
1507                 soisdisconnected(so);
1508         }
1509         INP_WUNLOCK(inp);
1510 }
1511
1512 static int
1513 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1514 {
1515         struct inpcb *inp;
1516         int error;
1517         struct sockaddr_in *sin;
1518
1519         inp = sotoinpcb(so);
1520         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1521         INP_WLOCK(inp);
1522         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1523                 INP_WUNLOCK(inp);
1524                 return (EISCONN);
1525         }
1526         sin = (struct sockaddr_in *)nam;
1527         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1528         if (error != 0) {
1529                 INP_WUNLOCK(inp);
1530                 return (error);
1531         }
1532         INP_HASH_WLOCK(&V_udbinfo);
1533         error = in_pcbconnect(inp, nam, td->td_ucred);
1534         INP_HASH_WUNLOCK(&V_udbinfo);
1535         if (error == 0)
1536                 soisconnected(so);
1537         INP_WUNLOCK(inp);
1538         return (error);
1539 }
1540
1541 static void
1542 udp_detach(struct socket *so)
1543 {
1544         struct inpcb *inp;
1545         struct udpcb *up;
1546
1547         inp = sotoinpcb(so);
1548         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1549         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1550             ("udp_detach: not disconnected"));
1551         INP_INFO_WLOCK(&V_udbinfo);
1552         INP_WLOCK(inp);
1553         up = intoudpcb(inp);
1554         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1555         inp->inp_ppcb = NULL;
1556         in_pcbdetach(inp);
1557         in_pcbfree(inp);
1558         INP_INFO_WUNLOCK(&V_udbinfo);
1559         udp_discardcb(up);
1560 }
1561
1562 static int
1563 udp_disconnect(struct socket *so)
1564 {
1565         struct inpcb *inp;
1566
1567         inp = sotoinpcb(so);
1568         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1569         INP_WLOCK(inp);
1570         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1571                 INP_WUNLOCK(inp);
1572                 return (ENOTCONN);
1573         }
1574         INP_HASH_WLOCK(&V_udbinfo);
1575         in_pcbdisconnect(inp);
1576         inp->inp_laddr.s_addr = INADDR_ANY;
1577         INP_HASH_WUNLOCK(&V_udbinfo);
1578         SOCK_LOCK(so);
1579         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1580         SOCK_UNLOCK(so);
1581         INP_WUNLOCK(inp);
1582         return (0);
1583 }
1584
1585 static int
1586 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1587     struct mbuf *control, struct thread *td)
1588 {
1589         struct inpcb *inp;
1590
1591         inp = sotoinpcb(so);
1592         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1593         return (udp_output(inp, m, addr, control, td));
1594 }
1595 #endif /* INET */
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 #ifdef INET
1611 struct pr_usrreqs udp_usrreqs = {
1612         .pru_abort =            udp_abort,
1613         .pru_attach =           udp_attach,
1614         .pru_bind =             udp_bind,
1615         .pru_connect =          udp_connect,
1616         .pru_control =          in_control,
1617         .pru_detach =           udp_detach,
1618         .pru_disconnect =       udp_disconnect,
1619         .pru_peeraddr =         in_getpeeraddr,
1620         .pru_send =             udp_send,
1621         .pru_soreceive =        soreceive_dgram,
1622         .pru_sosend =           sosend_dgram,
1623         .pru_shutdown =         udp_shutdown,
1624         .pru_sockaddr =         in_getsockaddr,
1625         .pru_sosetlabel =       in_pcbsosetlabel,
1626         .pru_close =            udp_close,
1627 };
1628 #endif /* INET */