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                 IPSECSTAT_INC(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         struct m_tag *fwd_tag;
 345
 346         ifp = m->m_pkthdr.rcvif;
 347         UDPSTAT_INC(udps_ipackets);
 348
 349         /*
 350          * Strip IP options, if any; should skip this, make available to
 351          * user, and use on returned packets, but we don't yet have a way to
 352          * check the checksum with options still present.
 353          */
 354         if (iphlen > sizeof (struct ip)) {
 355                 ip_stripoptions(m, (struct mbuf *)0);
 356                 iphlen = sizeof(struct ip);
 357         }
 358
 359         /*
 360          * Get IP and UDP header together in first mbuf.
 361          */
 362         ip = mtod(m, struct ip *);
 363         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 364                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 365                         UDPSTAT_INC(udps_hdrops);
 366                         return;
 367                 }
 368                 ip = mtod(m, struct ip *);
 369         }
 370         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 371
 372         /*
 373          * Destination port of 0 is illegal, based on RFC768.
 374          */
 375         if (uh->uh_dport == 0)
 376                 goto badunlocked;
 377
 378         /*
 379          * Construct sockaddr format source address.  Stuff source address
 380          * and datagram in user buffer.
 381          */
 382         bzero(&udp_in, sizeof(udp_in));
 383         udp_in.sin_len = sizeof(udp_in);
 384         udp_in.sin_family = AF_INET;
 385         udp_in.sin_port = uh->uh_sport;
 386         udp_in.sin_addr = ip->ip_src;
 387
 388         /*
 389          * Make mbuf data length reflect UDP length.  If not enough data to
 390          * reflect UDP length, drop.
 391          */
 392         len = ntohs((u_short)uh->uh_ulen);
 393         if (ip->ip_len != len) {
 394                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 395                         UDPSTAT_INC(udps_badlen);
 396                         goto badunlocked;
 397                 }
 398                 m_adj(m, len - ip->ip_len);
 399                 /* ip->ip_len = len; */
 400         }
 401
 402         /*
 403          * Save a copy of the IP header in case we want restore it for
 404          * sending an ICMP error message in response.
 405          */
 406         if (!V_udp_blackhole)
 407                 save_ip = *ip;
 408         else
 409                 memset(&save_ip, 0, sizeof(save_ip));
 410
 411         /*
 412          * Checksum extended UDP header and data.
 413          */
 414         if (uh->uh_sum) {
 415                 u_short uh_sum;
 416
 417                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 418                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 419                                 uh_sum = m->m_pkthdr.csum_data;
 420                         else
 421                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 422                                     ip->ip_dst.s_addr, htonl((u_short)len +
 423                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 424                         uh_sum ^= 0xffff;
 425                 } else {
 426                         char b[9];
 427
 428                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 429                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 430                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 431                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 432                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 433                 }
 434                 if (uh_sum) {
 435                         UDPSTAT_INC(udps_badsum);
 436                         m_freem(m);
 437                         return;
 438                 }
 439         } else
 440                 UDPSTAT_INC(udps_nosum);
 441
 442         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 443             in_broadcast(ip->ip_dst, ifp)) {
 444                 struct inpcb *last;
 445                 struct ip_moptions *imo;
 446
 447                 INP_INFO_RLOCK(&V_udbinfo);
 448                 last = NULL;
 449                 LIST_FOREACH(inp, &V_udb, inp_list) {
 450                         if (inp->inp_lport != uh->uh_dport)
 451                                 continue;
 452 #ifdef INET6
 453                         if ((inp->inp_vflag & INP_IPV4) == 0)
 454                                 continue;
 455 #endif
 456                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 457                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 458                                 continue;
 459                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 460                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 461                                 continue;
 462                         if (inp->inp_fport != 0 &&
 463                             inp->inp_fport != uh->uh_sport)
 464                                 continue;
 465
 466                         INP_RLOCK(inp);
 467
 468                         /*
 469                          * XXXRW: Because we weren't holding either the inpcb
 470                          * or the hash lock when we checked for a match
 471                          * before, we should probably recheck now that the
 472                          * inpcb lock is held.
 473                          */
 474
 475                         /*
 476                          * Handle socket delivery policy for any-source
 477                          * and source-specific multicast. [RFC3678]
 478                          */
 479                         imo = inp->inp_moptions;
 480                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 481                                 struct sockaddr_in       group;
 482                                 int                      blocked;
 483                                 if (imo == NULL) {
 484                                         INP_RUNLOCK(inp);
 485                                         continue;
 486                                 }
 487                                 bzero(&group, sizeof(struct sockaddr_in));
 488                                 group.sin_len = sizeof(struct sockaddr_in);
 489                                 group.sin_family = AF_INET;
 490                                 group.sin_addr = ip->ip_dst;
 491
 492                                 blocked = imo_multi_filter(imo, ifp,
 493                                         (struct sockaddr *)&group,
 494                                         (struct sockaddr *)&udp_in);
 495                                 if (blocked != MCAST_PASS) {
 496                                         if (blocked == MCAST_NOTGMEMBER)
 497                                                 IPSTAT_INC(ips_notmember);
 498                                         if (blocked == MCAST_NOTSMEMBER ||
 499                                             blocked == MCAST_MUTED)
 500                                                 UDPSTAT_INC(udps_filtermcast);
 501                                         INP_RUNLOCK(inp);
 502                                         continue;
 503                                 }
 504                         }
 505                         if (last != NULL) {
 506                                 struct mbuf *n;
 507
 508                                 n = m_copy(m, 0, M_COPYALL);
 509                                 udp_append(last, ip, n, iphlen, &udp_in);
 510                                 INP_RUNLOCK(last);
 511                         }
 512                         last = inp;
 513                         /*
 514                          * Don't look for additional matches if this one does
 515                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 516                          * socket options set.  This heuristic avoids
 517                          * searching through all pcbs in the common case of a
 518                          * non-shared port.  It assumes that an application
 519                          * will never clear these options after setting them.
 520                          */
 521                         if ((last->inp_socket->so_options &
 522                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 523                                 break;
 524                 }
 525
 526                 if (last == NULL) {
 527                         /*
 528                          * No matching pcb found; discard datagram.  (No need
 529                          * to send an ICMP Port Unreachable for a broadcast
 530                          * or multicast datgram.)
 531                          */
 532                         UDPSTAT_INC(udps_noportbcast);
 533                         if (inp)
 534                                 INP_RUNLOCK(inp);
 535                         INP_INFO_RUNLOCK(&V_udbinfo);
 536                         goto badunlocked;
 537                 }
 538                 udp_append(last, ip, m, iphlen, &udp_in);
 539                 INP_RUNLOCK(last);
 540                 INP_INFO_RUNLOCK(&V_udbinfo);
 541                 return;
 542         }
 543
 544         /*
 545          * Locate pcb for datagram.
 546          */
 547
 548         /*
 549          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 550          */
 551         if ((m->m_flags & M_IP_NEXTHOP) &&
 552             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 553                 struct sockaddr_in *next_hop;
 554
 555                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 556
 557                 /*
 558                  * Transparently forwarded. Pretend to be the destination.
 559                  * Already got one like this?
 560                  */
 561                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 562                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
 563                 if (!inp) {
 564                         /*
 565                          * It's new.  Try to find the ambushing socket.
 566                          * Because we've rewritten the destination address,
 567                          * any hardware-generated hash is ignored.
 568                          */
 569                         inp = in_pcblookup(&V_udbinfo, ip->ip_src,
 570                             uh->uh_sport, next_hop->sin_addr,
 571                             next_hop->sin_port ? htons(next_hop->sin_port) :
 572                             uh->uh_dport, INPLOOKUP_WILDCARD |
 573                             INPLOOKUP_RLOCKPCB, ifp);
 574                 }
 575                 /* Remove the tag from the packet. We don't need it anymore. */
 576                 m_tag_delete(m, fwd_tag);
 577                 m->m_flags &= ~M_IP_NEXTHOP;
 578         } else
 579                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 580                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
 581                     INPLOOKUP_RLOCKPCB, ifp, m);
 582         if (inp == NULL) {
 583                 if (udp_log_in_vain) {
 584                         char buf[4*sizeof "123"];
 585
 586                         strcpy(buf, inet_ntoa(ip->ip_dst));
 587                         log(LOG_INFO,
 588                             "Connection attempt to UDP %s:%d from %s:%d\n",
 589                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 590                             ntohs(uh->uh_sport));
 591                 }
 592                 UDPSTAT_INC(udps_noport);
 593                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 594                         UDPSTAT_INC(udps_noportbcast);
 595                         goto badunlocked;
 596                 }
 597                 if (V_udp_blackhole)
 598                         goto badunlocked;
 599                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 600                         goto badunlocked;
 601                 *ip = save_ip;
 602                 ip->ip_len += iphlen;
 603                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 604                 return;
 605         }
 606
 607         /*
 608          * Check the minimum TTL for socket.
 609          */
 610         INP_RLOCK_ASSERT(inp);
 611         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 612                 INP_RUNLOCK(inp);
 613                 m_freem(m);
 614                 return;
 615         }
 616         udp_append(inp, ip, m, iphlen, &udp_in);
 617         INP_RUNLOCK(inp);
 618         return;
 619
 620 badunlocked:
 621         m_freem(m);
 622 }
 623 #endif /* INET */
 624
 625 /*
 626  * Notify a udp user of an asynchronous error; just wake up so that they can
 627  * collect error status.
 628  */
 629 struct inpcb *
 630 udp_notify(struct inpcb *inp, int errno)
 631 {
 632
 633         /*
 634          * While udp_ctlinput() always calls udp_notify() with a read lock
 635          * when invoking it directly, in_pcbnotifyall() currently uses write
 636          * locks due to sharing code with TCP.  For now, accept either a read
 637          * or a write lock, but a read lock is sufficient.
 638          */
 639         INP_LOCK_ASSERT(inp);
 640
 641         inp->inp_socket->so_error = errno;
 642         sorwakeup(inp->inp_socket);
 643         sowwakeup(inp->inp_socket);
 644         return (inp);
 645 }
 646
 647 #ifdef INET
 648 void
 649 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 650 {
 651         struct ip *ip = vip;
 652         struct udphdr *uh;
 653         struct in_addr faddr;
 654         struct inpcb *inp;
 655
 656         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 657         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 658                 return;
 659
 660         /*
 661          * Redirects don't need to be handled up here.
 662          */
 663         if (PRC_IS_REDIRECT(cmd))
 664                 return;
 665
 666         /*
 667          * Hostdead is ugly because it goes linearly through all PCBs.
 668          *
 669          * XXX: We never get this from ICMP, otherwise it makes an excellent
 670          * DoS attack on machines with many connections.
 671          */
 672         if (cmd == PRC_HOSTDEAD)
 673                 ip = NULL;
 674         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 675                 return;
 676         if (ip != NULL) {
 677                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 678                 inp = in_pcblookup(&V_udbinfo, faddr, uh->uh_dport,
 679                     ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
 680                 if (inp != NULL) {
 681                         INP_RLOCK_ASSERT(inp);
 682                         if (inp->inp_socket != NULL) {
 683                                 udp_notify(inp, inetctlerrmap[cmd]);
 684                         }
 685                         INP_RUNLOCK(inp);
 686                 }
 687         } else
 688                 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
 689                     udp_notify);
 690 }
 691 #endif /* INET */
 692
 693 static int
 694 udp_pcblist(SYSCTL_HANDLER_ARGS)
 695 {
 696         int error, i, n;
 697         struct inpcb *inp, **inp_list;
 698         inp_gen_t gencnt;
 699         struct xinpgen xig;
 700
 701         /*
 702          * The process of preparing the PCB list is too time-consuming and
 703          * resource-intensive to repeat twice on every request.
 704          */
 705         if (req->oldptr == 0) {
 706                 n = V_udbinfo.ipi_count;
 707                 n += imax(n / 8, 10);
 708                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 709                 return (0);
 710         }
 711
 712         if (req->newptr != 0)
 713                 return (EPERM);
 714
 715         /*
 716          * OK, now we're committed to doing something.
 717          */
 718         INP_INFO_RLOCK(&V_udbinfo);
 719         gencnt = V_udbinfo.ipi_gencnt;
 720         n = V_udbinfo.ipi_count;
 721         INP_INFO_RUNLOCK(&V_udbinfo);
 722
 723         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 724                 + n * sizeof(struct xinpcb));
 725         if (error != 0)
 726                 return (error);
 727
 728         xig.xig_len = sizeof xig;
 729         xig.xig_count = n;
 730         xig.xig_gen = gencnt;
 731         xig.xig_sogen = so_gencnt;
 732         error = SYSCTL_OUT(req, &xig, sizeof xig);
 733         if (error)
 734                 return (error);
 735
 736         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 737         if (inp_list == 0)
 738                 return (ENOMEM);
 739
 740         INP_INFO_RLOCK(&V_udbinfo);
 741         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
 742              inp = LIST_NEXT(inp, inp_list)) {
 743                 INP_WLOCK(inp);
 744                 if (inp->inp_gencnt <= gencnt &&
 745                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
 746                         in_pcbref(inp);
 747                         inp_list[i++] = inp;
 748                 }
 749                 INP_WUNLOCK(inp);
 750         }
 751         INP_INFO_RUNLOCK(&V_udbinfo);
 752         n = i;
 753
 754         error = 0;
 755         for (i = 0; i < n; i++) {
 756                 inp = inp_list[i];
 757                 INP_RLOCK(inp);
 758                 if (inp->inp_gencnt <= gencnt) {
 759                         struct xinpcb xi;
 760
 761                         bzero(&xi, sizeof(xi));
 762                         xi.xi_len = sizeof xi;
 763                         /* XXX should avoid extra copy */
 764                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 765                         if (inp->inp_socket)
 766                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 767                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 768                         INP_RUNLOCK(inp);
 769                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 770                 } else
 771                         INP_RUNLOCK(inp);
 772         }
 773         INP_INFO_WLOCK(&V_udbinfo);
 774         for (i = 0; i < n; i++) {
 775                 inp = inp_list[i];
 776                 INP_RLOCK(inp);
 777                 if (!in_pcbrele_rlocked(inp))
 778                         INP_RUNLOCK(inp);
 779         }
 780         INP_INFO_WUNLOCK(&V_udbinfo);
 781
 782         if (!error) {
 783                 /*
 784                  * Give the user an updated idea of our state.  If the
 785                  * generation differs from what we told her before, she knows
 786                  * that something happened while we were processing this
 787                  * request, and it might be necessary to retry.
 788                  */
 789                 INP_INFO_RLOCK(&V_udbinfo);
 790                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 791                 xig.xig_sogen = so_gencnt;
 792                 xig.xig_count = V_udbinfo.ipi_count;
 793                 INP_INFO_RUNLOCK(&V_udbinfo);
 794                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 795         }
 796         free(inp_list, M_TEMP);
 797         return (error);
 798 }
 799
 800 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
 801     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
 802     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 803
 804 #ifdef INET
 805 static int
 806 udp_getcred(SYSCTL_HANDLER_ARGS)
 807 {
 808         struct xucred xuc;
 809         struct sockaddr_in addrs[2];
 810         struct inpcb *inp;
 811         int error;
 812
 813         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 814         if (error)
 815                 return (error);
 816         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 817         if (error)
 818                 return (error);
 819         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 820             addrs[0].sin_addr, addrs[0].sin_port,
 821             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 822         if (inp != NULL) {
 823                 INP_RLOCK_ASSERT(inp);
 824                 if (inp->inp_socket == NULL)
 825                         error = ENOENT;
 826                 if (error == 0)
 827                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 828                 if (error == 0)
 829                         cru2x(inp->inp_cred, &xuc);
 830                 INP_RUNLOCK(inp);
 831         } else
 832                 error = ENOENT;
 833         if (error == 0)
 834                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 835         return (error);
 836 }
 837
 838 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 839     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 840     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 841 #endif /* INET */
 842
 843 int
 844 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 845 {
 846         int error = 0, optval;
 847         struct inpcb *inp;
 848 #ifdef IPSEC_NAT_T
 849         struct udpcb *up;
 850 #endif
 851
 852         inp = sotoinpcb(so);
 853         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 854         INP_WLOCK(inp);
 855         if (sopt->sopt_level != IPPROTO_UDP) {
 856 #ifdef INET6
 857                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 858                         INP_WUNLOCK(inp);
 859                         error = ip6_ctloutput(so, sopt);
 860                 }
 861 #endif
 862 #if defined(INET) && defined(INET6)
 863                 else
 864 #endif
 865 #ifdef INET
 866                 {
 867                         INP_WUNLOCK(inp);
 868                         error = ip_ctloutput(so, sopt);
 869                 }
 870 #endif
 871                 return (error);
 872         }
 873
 874         switch (sopt->sopt_dir) {
 875         case SOPT_SET:
 876                 switch (sopt->sopt_name) {
 877                 case UDP_ENCAP:
 878                         INP_WUNLOCK(inp);
 879                         error = sooptcopyin(sopt, &optval, sizeof optval,
 880                                             sizeof optval);
 881                         if (error)
 882                                 break;
 883                         inp = sotoinpcb(so);
 884                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 885                         INP_WLOCK(inp);
 886 #ifdef IPSEC_NAT_T
 887                         up = intoudpcb(inp);
 888                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 889 #endif
 890                         switch (optval) {
 891                         case 0:
 892                                 /* Clear all UDP encap. */
 893 #ifdef IPSEC_NAT_T
 894                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 895 #endif
 896                                 break;
 897 #ifdef IPSEC_NAT_T
 898                         case UDP_ENCAP_ESPINUDP:
 899                         case UDP_ENCAP_ESPINUDP_NON_IKE:
 900                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 901                                 if (optval == UDP_ENCAP_ESPINUDP)
 902                                         up->u_flags |= UF_ESPINUDP;
 903                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
 904                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
 905                                 break;
 906 #endif
 907                         default:
 908                                 error = EINVAL;
 909                                 break;
 910                         }
 911                         INP_WUNLOCK(inp);
 912                         break;
 913                 default:
 914                         INP_WUNLOCK(inp);
 915                         error = ENOPROTOOPT;
 916                         break;
 917                 }
 918                 break;
 919         case SOPT_GET:
 920                 switch (sopt->sopt_name) {
 921 #ifdef IPSEC_NAT_T
 922                 case UDP_ENCAP:
 923                         up = intoudpcb(inp);
 924                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 925                         optval = up->u_flags & UF_ESPINUDP_ALL;
 926                         INP_WUNLOCK(inp);
 927                         error = sooptcopyout(sopt, &optval, sizeof optval);
 928                         break;
 929 #endif
 930                 default:
 931                         INP_WUNLOCK(inp);
 932                         error = ENOPROTOOPT;
 933                         break;
 934                 }
 935                 break;
 936         }
 937         return (error);
 938 }
 939
 940 #ifdef INET
 941 #define UH_WLOCKED      2
 942 #define UH_RLOCKED      1
 943 #define UH_UNLOCKED     0
 944 static int
 945 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
 946     struct mbuf *control, struct thread *td)
 947 {
 948         struct udpiphdr *ui;
 949         int len = m->m_pkthdr.len;
 950         struct in_addr faddr, laddr;
 951         struct cmsghdr *cm;
 952         struct sockaddr_in *sin, src;
 953         int error = 0;
 954         int ipflags;
 955         u_short fport, lport;
 956         int unlock_udbinfo;
 957         u_char tos;
 958
 959         /*
 960          * udp_output() may need to temporarily bind or connect the current
 961          * inpcb.  As such, we don't know up front whether we will need the
 962          * pcbinfo lock or not.  Do any work to decide what is needed up
 963          * front before acquiring any locks.
 964          */
 965         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 966                 if (control)
 967                         m_freem(control);
 968                 m_freem(m);
 969                 return (EMSGSIZE);
 970         }
 971
 972         src.sin_family = 0;
 973         INP_RLOCK(inp);
 974         tos = inp->inp_ip_tos;
 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                         case IP_TOS:
1014                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1015                                         error = EINVAL;
1016                                         break;
1017                                 }
1018                                 tos = *(u_char *)CMSG_DATA(cm);
1019                                 break;
1020
1021                         default:
1022                                 error = ENOPROTOOPT;
1023                                 break;
1024                         }
1025                         if (error)
1026                                 break;
1027                 }
1028                 m_freem(control);
1029         }
1030         if (error) {
1031                 INP_RUNLOCK(inp);
1032                 m_freem(m);
1033                 return (error);
1034         }
1035
1036         /*
1037          * Depending on whether or not the application has bound or connected
1038          * the socket, we may have to do varying levels of work.  The optimal
1039          * case is for a connected UDP socket, as a global lock isn't
1040          * required at all.
1041          *
1042          * In order to decide which we need, we require stability of the
1043          * inpcb binding, which we ensure by acquiring a read lock on the
1044          * inpcb.  This doesn't strictly follow the lock order, so we play
1045          * the trylock and retry game; note that we may end up with more
1046          * conservative locks than required the second time around, so later
1047          * assertions have to accept that.  Further analysis of the number of
1048          * misses under contention is required.
1049          *
1050          * XXXRW: Check that hash locking update here is correct.
1051          */
1052         sin = (struct sockaddr_in *)addr;
1053         if (sin != NULL &&
1054             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1055                 INP_RUNLOCK(inp);
1056                 INP_WLOCK(inp);
1057                 INP_HASH_WLOCK(&V_udbinfo);
1058                 unlock_udbinfo = UH_WLOCKED;
1059         } else if ((sin != NULL && (
1060             (sin->sin_addr.s_addr == INADDR_ANY) ||
1061             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1062             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1063             (inp->inp_lport == 0))) ||
1064             (src.sin_family == AF_INET)) {
1065                 INP_HASH_RLOCK(&V_udbinfo);
1066                 unlock_udbinfo = UH_RLOCKED;
1067         } else
1068                 unlock_udbinfo = UH_UNLOCKED;
1069
1070         /*
1071          * If the IP_SENDSRCADDR control message was specified, override the
1072          * source address for this datagram.  Its use is invalidated if the
1073          * address thus specified is incomplete or clobbers other inpcbs.
1074          */
1075         laddr = inp->inp_laddr;
1076         lport = inp->inp_lport;
1077         if (src.sin_family == AF_INET) {
1078                 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1079                 if ((lport == 0) ||
1080                     (laddr.s_addr == INADDR_ANY &&
1081                      src.sin_addr.s_addr == INADDR_ANY)) {
1082                         error = EINVAL;
1083                         goto release;
1084                 }
1085                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1086                     &laddr.s_addr, &lport, td->td_ucred);
1087                 if (error)
1088                         goto release;
1089         }
1090
1091         /*
1092          * If a UDP socket has been connected, then a local address/port will
1093          * have been selected and bound.
1094          *
1095          * If a UDP socket has not been connected to, then an explicit
1096          * destination address must be used, in which case a local
1097          * address/port may not have been selected and bound.
1098          */
1099         if (sin != NULL) {
1100                 INP_LOCK_ASSERT(inp);
1101                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1102                         error = EISCONN;
1103                         goto release;
1104                 }
1105
1106                 /*
1107                  * Jail may rewrite the destination address, so let it do
1108                  * that before we use it.
1109                  */
1110                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1111                 if (error)
1112                         goto release;
1113
1114                 /*
1115                  * If a local address or port hasn't yet been selected, or if
1116                  * the destination address needs to be rewritten due to using
1117                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1118                  * to do the heavy lifting.  Once a port is selected, we
1119                  * commit the binding back to the socket; we also commit the
1120                  * binding of the address if in jail.
1121                  *
1122                  * If we already have a valid binding and we're not
1123                  * requesting a destination address rewrite, use a fast path.
1124                  */
1125                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1126                     inp->inp_lport == 0 ||
1127                     sin->sin_addr.s_addr == INADDR_ANY ||
1128                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1129                         INP_HASH_LOCK_ASSERT(&V_udbinfo);
1130                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1131                             &lport, &faddr.s_addr, &fport, NULL,
1132                             td->td_ucred);
1133                         if (error)
1134                                 goto release;
1135
1136                         /*
1137                          * XXXRW: Why not commit the port if the address is
1138                          * !INADDR_ANY?
1139                          */
1140                         /* Commit the local port if newly assigned. */
1141                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1142                             inp->inp_lport == 0) {
1143                                 INP_WLOCK_ASSERT(inp);
1144                                 INP_HASH_WLOCK_ASSERT(&V_udbinfo);
1145                                 /*
1146                                  * Remember addr if jailed, to prevent
1147                                  * rebinding.
1148                                  */
1149                                 if (prison_flag(td->td_ucred, PR_IP4))
1150                                         inp->inp_laddr = laddr;
1151                                 inp->inp_lport = lport;
1152                                 if (in_pcbinshash(inp) != 0) {
1153                                         inp->inp_lport = 0;
1154                                         error = EAGAIN;
1155                                         goto release;
1156                                 }
1157                                 inp->inp_flags |= INP_ANONPORT;
1158                         }
1159                 } else {
1160                         faddr = sin->sin_addr;
1161                         fport = sin->sin_port;
1162                 }
1163         } else {
1164                 INP_LOCK_ASSERT(inp);
1165                 faddr = inp->inp_faddr;
1166                 fport = inp->inp_fport;
1167                 if (faddr.s_addr == INADDR_ANY) {
1168                         error = ENOTCONN;
1169                         goto release;
1170                 }
1171         }
1172
1173         /*
1174          * Calculate data length and get a mbuf for UDP, IP, and possible
1175          * link-layer headers.  Immediate slide the data pointer back forward
1176          * since we won't use that space at this layer.
1177          */
1178         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT);
1179         if (m == NULL) {
1180                 error = ENOBUFS;
1181                 goto release;
1182         }
1183         m->m_data += max_linkhdr;
1184         m->m_len -= max_linkhdr;
1185         m->m_pkthdr.len -= max_linkhdr;
1186
1187         /*
1188          * Fill in mbuf with extended UDP header and addresses and length put
1189          * into network format.
1190          */
1191         ui = mtod(m, struct udpiphdr *);
1192         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1193         ui->ui_pr = IPPROTO_UDP;
1194         ui->ui_src = laddr;
1195         ui->ui_dst = faddr;
1196         ui->ui_sport = lport;
1197         ui->ui_dport = fport;
1198         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1199
1200         /*
1201          * Set the Don't Fragment bit in the IP header.
1202          */
1203         if (inp->inp_flags & INP_DONTFRAG) {
1204                 struct ip *ip;
1205
1206                 ip = (struct ip *)&ui->ui_i;
1207                 ip->ip_off |= IP_DF;
1208         }
1209
1210         ipflags = 0;
1211         if (inp->inp_socket->so_options & SO_DONTROUTE)
1212                 ipflags |= IP_ROUTETOIF;
1213         if (inp->inp_socket->so_options & SO_BROADCAST)
1214                 ipflags |= IP_ALLOWBROADCAST;
1215         if (inp->inp_flags & INP_ONESBCAST)
1216                 ipflags |= IP_SENDONES;
1217
1218 #ifdef MAC
1219         mac_inpcb_create_mbuf(inp, m);
1220 #endif
1221
1222         /*
1223          * Set up checksum and output datagram.
1224          */
1225         if (V_udp_cksum) {
1226                 if (inp->inp_flags & INP_ONESBCAST)
1227                         faddr.s_addr = INADDR_BROADCAST;
1228                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1229                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1230                 m->m_pkthdr.csum_flags = CSUM_UDP;
1231                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1232         } else
1233                 ui->ui_sum = 0;
1234         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
1235         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1236         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1237         UDPSTAT_INC(udps_opackets);
1238
1239         if (unlock_udbinfo == UH_WLOCKED)
1240                 INP_HASH_WUNLOCK(&V_udbinfo);
1241         else if (unlock_udbinfo == UH_RLOCKED)
1242                 INP_HASH_RUNLOCK(&V_udbinfo);
1243         error = ip_output(m, inp->inp_options, NULL, ipflags,
1244             inp->inp_moptions, inp);
1245         if (unlock_udbinfo == UH_WLOCKED)
1246                 INP_WUNLOCK(inp);
1247         else
1248                 INP_RUNLOCK(inp);
1249         return (error);
1250
1251 release:
1252         if (unlock_udbinfo == UH_WLOCKED) {
1253                 INP_HASH_WUNLOCK(&V_udbinfo);
1254                 INP_WUNLOCK(inp);
1255         } else if (unlock_udbinfo == UH_RLOCKED) {
1256                 INP_HASH_RUNLOCK(&V_udbinfo);
1257                 INP_RUNLOCK(inp);
1258         } else
1259                 INP_RUNLOCK(inp);
1260         m_freem(m);
1261         return (error);
1262 }
1263
1264
1265 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1266 /*
1267  * Potentially decap ESP in UDP frame.  Check for an ESP header
1268  * and optional marker; if present, strip the UDP header and
1269  * push the result through IPSec.
1270  *
1271  * Returns mbuf to be processed (potentially re-allocated) or
1272  * NULL if consumed and/or processed.
1273  */
1274 static struct mbuf *
1275 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1276 {
1277         size_t minlen, payload, skip, iphlen;
1278         caddr_t data;
1279         struct udpcb *up;
1280         struct m_tag *tag;
1281         struct udphdr *udphdr;
1282         struct ip *ip;
1283
1284         INP_RLOCK_ASSERT(inp);
1285
1286         /*
1287          * Pull up data so the longest case is contiguous:
1288          *    IP/UDP hdr + non ESP marker + ESP hdr.
1289          */
1290         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1291         if (minlen > m->m_pkthdr.len)
1292                 minlen = m->m_pkthdr.len;
1293         if ((m = m_pullup(m, minlen)) == NULL) {
1294                 IPSECSTAT_INC(in_inval);
1295                 return (NULL);          /* Bypass caller processing. */
1296         }
1297         data = mtod(m, caddr_t);        /* Points to ip header. */
1298         payload = m->m_len - off;       /* Size of payload. */
1299
1300         if (payload == 1 && data[off] == '\xff')
1301                 return (m);             /* NB: keepalive packet, no decap. */
1302
1303         up = intoudpcb(inp);
1304         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1305         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1306             ("u_flags 0x%x", up->u_flags));
1307
1308         /*
1309          * Check that the payload is large enough to hold an
1310          * ESP header and compute the amount of data to remove.
1311          *
1312          * NB: the caller has already done a pullup for us.
1313          * XXX can we assume alignment and eliminate bcopys?
1314          */
1315         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1316                 /*
1317                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1318                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1319                  * possible AH mode non-IKE marker+non-ESP marker
1320                  * from draft-ietf-ipsec-udp-encaps-00.txt.
1321                  */
1322                 uint64_t marker;
1323
1324                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1325                         return (m);     /* NB: no decap. */
1326                 bcopy(data + off, &marker, sizeof(uint64_t));
1327                 if (marker != 0)        /* Non-IKE marker. */
1328                         return (m);     /* NB: no decap. */
1329                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1330         } else {
1331                 uint32_t spi;
1332
1333                 if (payload <= sizeof(struct esp)) {
1334                         IPSECSTAT_INC(in_inval);
1335                         m_freem(m);
1336                         return (NULL);  /* Discard. */
1337                 }
1338                 bcopy(data + off, &spi, sizeof(uint32_t));
1339                 if (spi == 0)           /* Non-ESP marker. */
1340                         return (m);     /* NB: no decap. */
1341                 skip = sizeof(struct udphdr);
1342         }
1343
1344         /*
1345          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1346          * the UDP ports. This is required if we want to select
1347          * the right SPD for multiple hosts behind same NAT.
1348          *
1349          * NB: ports are maintained in network byte order everywhere
1350          *     in the NAT-T code.
1351          */
1352         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1353                 2 * sizeof(uint16_t), M_NOWAIT);
1354         if (tag == NULL) {
1355                 IPSECSTAT_INC(in_nomem);
1356                 m_freem(m);
1357                 return (NULL);          /* Discard. */
1358         }
1359         iphlen = off - sizeof(struct udphdr);
1360         udphdr = (struct udphdr *)(data + iphlen);
1361         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1362         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1363         m_tag_prepend(m, tag);
1364
1365         /*
1366          * Remove the UDP header (and possibly the non ESP marker)
1367          * IP header length is iphlen
1368          * Before:
1369          *   <--- off --->
1370          *   +----+------+-----+
1371          *   | IP |  UDP | ESP |
1372          *   +----+------+-----+
1373          *        <-skip->
1374          * After:
1375          *          +----+-----+
1376          *          | IP | ESP |
1377          *          +----+-----+
1378          *   <-skip->
1379          */
1380         ovbcopy(data, data + skip, iphlen);
1381         m_adj(m, skip);
1382
1383         ip = mtod(m, struct ip *);
1384         ip->ip_len -= skip;
1385         ip->ip_p = IPPROTO_ESP;
1386
1387         /*
1388          * We cannot yet update the cksums so clear any
1389          * h/w cksum flags as they are no longer valid.
1390          */
1391         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1392                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1393
1394         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1395         return (NULL);                  /* NB: consumed, bypass processing. */
1396 }
1397 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1398
1399 static void
1400 udp_abort(struct socket *so)
1401 {
1402         struct inpcb *inp;
1403
1404         inp = sotoinpcb(so);
1405         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1406         INP_WLOCK(inp);
1407         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1408                 INP_HASH_WLOCK(&V_udbinfo);
1409                 in_pcbdisconnect(inp);
1410                 inp->inp_laddr.s_addr = INADDR_ANY;
1411                 INP_HASH_WUNLOCK(&V_udbinfo);
1412                 soisdisconnected(so);
1413         }
1414         INP_WUNLOCK(inp);
1415 }
1416
1417 static int
1418 udp_attach(struct socket *so, int proto, struct thread *td)
1419 {
1420         struct inpcb *inp;
1421         int error;
1422
1423         inp = sotoinpcb(so);
1424         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1425         error = soreserve(so, udp_sendspace, udp_recvspace);
1426         if (error)
1427                 return (error);
1428         INP_INFO_WLOCK(&V_udbinfo);
1429         error = in_pcballoc(so, &V_udbinfo);
1430         if (error) {
1431                 INP_INFO_WUNLOCK(&V_udbinfo);
1432                 return (error);
1433         }
1434
1435         inp = sotoinpcb(so);
1436         inp->inp_vflag |= INP_IPV4;
1437         inp->inp_ip_ttl = V_ip_defttl;
1438
1439         error = udp_newudpcb(inp);
1440         if (error) {
1441                 in_pcbdetach(inp);
1442                 in_pcbfree(inp);
1443                 INP_INFO_WUNLOCK(&V_udbinfo);
1444                 return (error);
1445         }
1446
1447         INP_WUNLOCK(inp);
1448         INP_INFO_WUNLOCK(&V_udbinfo);
1449         return (0);
1450 }
1451 #endif /* INET */
1452
1453 int
1454 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1455 {
1456         struct inpcb *inp;
1457         struct udpcb *up;
1458
1459         KASSERT(so->so_type == SOCK_DGRAM,
1460             ("udp_set_kernel_tunneling: !dgram"));
1461         inp = sotoinpcb(so);
1462         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1463         INP_WLOCK(inp);
1464         up = intoudpcb(inp);
1465         if (up->u_tun_func != NULL) {
1466                 INP_WUNLOCK(inp);
1467                 return (EBUSY);
1468         }
1469         up->u_tun_func = f;
1470         INP_WUNLOCK(inp);
1471         return (0);
1472 }
1473
1474 #ifdef INET
1475 static int
1476 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1477 {
1478         struct inpcb *inp;
1479         int error;
1480
1481         inp = sotoinpcb(so);
1482         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1483         INP_WLOCK(inp);
1484         INP_HASH_WLOCK(&V_udbinfo);
1485         error = in_pcbbind(inp, nam, td->td_ucred);
1486         INP_HASH_WUNLOCK(&V_udbinfo);
1487         INP_WUNLOCK(inp);
1488         return (error);
1489 }
1490
1491 static void
1492 udp_close(struct socket *so)
1493 {
1494         struct inpcb *inp;
1495
1496         inp = sotoinpcb(so);
1497         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1498         INP_WLOCK(inp);
1499         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1500                 INP_HASH_WLOCK(&V_udbinfo);
1501                 in_pcbdisconnect(inp);
1502                 inp->inp_laddr.s_addr = INADDR_ANY;
1503                 INP_HASH_WUNLOCK(&V_udbinfo);
1504                 soisdisconnected(so);
1505         }
1506         INP_WUNLOCK(inp);
1507 }
1508
1509 static int
1510 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1511 {
1512         struct inpcb *inp;
1513         int error;
1514         struct sockaddr_in *sin;
1515
1516         inp = sotoinpcb(so);
1517         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1518         INP_WLOCK(inp);
1519         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1520                 INP_WUNLOCK(inp);
1521                 return (EISCONN);
1522         }
1523         sin = (struct sockaddr_in *)nam;
1524         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1525         if (error != 0) {
1526                 INP_WUNLOCK(inp);
1527                 return (error);
1528         }
1529         INP_HASH_WLOCK(&V_udbinfo);
1530         error = in_pcbconnect(inp, nam, td->td_ucred);
1531         INP_HASH_WUNLOCK(&V_udbinfo);
1532         if (error == 0)
1533                 soisconnected(so);
1534         INP_WUNLOCK(inp);
1535         return (error);
1536 }
1537
1538 static void
1539 udp_detach(struct socket *so)
1540 {
1541         struct inpcb *inp;
1542         struct udpcb *up;
1543
1544         inp = sotoinpcb(so);
1545         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1546         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1547             ("udp_detach: not disconnected"));
1548         INP_INFO_WLOCK(&V_udbinfo);
1549         INP_WLOCK(inp);
1550         up = intoudpcb(inp);
1551         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1552         inp->inp_ppcb = NULL;
1553         in_pcbdetach(inp);
1554         in_pcbfree(inp);
1555         INP_INFO_WUNLOCK(&V_udbinfo);
1556         udp_discardcb(up);
1557 }
1558
1559 static int
1560 udp_disconnect(struct socket *so)
1561 {
1562         struct inpcb *inp;
1563
1564         inp = sotoinpcb(so);
1565         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1566         INP_WLOCK(inp);
1567         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1568                 INP_WUNLOCK(inp);
1569                 return (ENOTCONN);
1570         }
1571         INP_HASH_WLOCK(&V_udbinfo);
1572         in_pcbdisconnect(inp);
1573         inp->inp_laddr.s_addr = INADDR_ANY;
1574         INP_HASH_WUNLOCK(&V_udbinfo);
1575         SOCK_LOCK(so);
1576         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1577         SOCK_UNLOCK(so);
1578         INP_WUNLOCK(inp);
1579         return (0);
1580 }
1581
1582 static int
1583 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1584     struct mbuf *control, struct thread *td)
1585 {
1586         struct inpcb *inp;
1587
1588         inp = sotoinpcb(so);
1589         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1590         return (udp_output(inp, m, addr, control, td));
1591 }
1592 #endif /* INET */
1593
1594 int
1595 udp_shutdown(struct socket *so)
1596 {
1597         struct inpcb *inp;
1598
1599         inp = sotoinpcb(so);
1600         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1601         INP_WLOCK(inp);
1602         socantsendmore(so);
1603         INP_WUNLOCK(inp);
1604         return (0);
1605 }
1606
1607 #ifdef INET
1608 struct pr_usrreqs udp_usrreqs = {
1609         .pru_abort =            udp_abort,
1610         .pru_attach =           udp_attach,
1611         .pru_bind =             udp_bind,
1612         .pru_connect =          udp_connect,
1613         .pru_control =          in_control,
1614         .pru_detach =           udp_detach,
1615         .pru_disconnect =       udp_disconnect,
1616         .pru_peeraddr =         in_getpeeraddr,
1617         .pru_send =             udp_send,
1618         .pru_soreceive =        soreceive_dgram,
1619         .pru_sosend =           sosend_dgram,
1620         .pru_shutdown =         udp_shutdown,
1621         .pru_sockaddr =         in_getsockaddr,
1622         .pru_sosetlabel =       in_pcbsosetlabel,
1623         .pru_close =            udp_close,
1624 };
1625 #endif /* INET */