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 #include "opt_kdtrace.h"
  46
  47 #include <sys/param.h>
  48 #include <sys/domain.h>
  49 #include <sys/eventhandler.h>
  50 #include <sys/jail.h>
  51 #include <sys/kernel.h>
  52 #include <sys/lock.h>
  53 #include <sys/malloc.h>
  54 #include <sys/mbuf.h>
  55 #include <sys/priv.h>
  56 #include <sys/proc.h>
  57 #include <sys/protosw.h>
  58 #include <sys/sdt.h>
  59 #include <sys/signalvar.h>
  60 #include <sys/socket.h>
  61 #include <sys/socketvar.h>
  62 #include <sys/sx.h>
  63 #include <sys/sysctl.h>
  64 #include <sys/syslog.h>
  65 #include <sys/systm.h>
  66
  67 #include <vm/uma.h>
  68
  69 #include <net/if.h>
  70 #include <net/route.h>
  71
  72 #include <netinet/in.h>
  73 #include <netinet/in_kdtrace.h>
  74 #include <netinet/in_pcb.h>
  75 #include <netinet/in_systm.h>
  76 #include <netinet/in_var.h>
  77 #include <netinet/ip.h>
  78 #ifdef INET6
  79 #include <netinet/ip6.h>
  80 #endif
  81 #include <netinet/ip_icmp.h>
  82 #include <netinet/icmp_var.h>
  83 #include <netinet/ip_var.h>
  84 #include <netinet/ip_options.h>
  85 #ifdef INET6
  86 #include <netinet6/ip6_var.h>
  87 #endif
  88 #include <netinet/udp.h>
  89 #include <netinet/udp_var.h>
  90
  91 #ifdef IPSEC
  92 #include <netipsec/ipsec.h>
  93 #include <netipsec/esp.h>
  94 #endif
  95
  96 #include <machine/in_cksum.h>
  97
  98 #include <security/mac/mac_framework.h>
  99
 100 /*
 101  * UDP protocol implementation.
 102  * Per RFC 768, August, 1980.
 103  */
 104
 105 /*
 106  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
 107  * removes the only data integrity mechanism for packets and malformed
 108  * packets that would otherwise be discarded due to bad checksums, and may
 109  * cause problems (especially for NFS data blocks).
 110  */
 111 VNET_DEFINE(int, udp_cksum) = 1;
 112 SYSCTL_VNET_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
 113     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
 114
 115 int     udp_log_in_vain = 0;
 116 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 117     &udp_log_in_vain, 0, "Log all incoming UDP packets");
 118
 119 VNET_DEFINE(int, udp_blackhole) = 0;
 120 SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 121     &VNET_NAME(udp_blackhole), 0,
 122     "Do not send port unreachables for refused connects");
 123
 124 u_long  udp_sendspace = 9216;           /* really max datagram size */
 125                                         /* 40 1K datagrams */
 126 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 127     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 128
 129 u_long  udp_recvspace = 40 * (1024 +
 130 #ifdef INET6
 131                                       sizeof(struct sockaddr_in6)
 132 #else
 133                                       sizeof(struct sockaddr_in)
 134 #endif
 135                                       );
 136
 137 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 138     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 139
 140 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
 141 VNET_DEFINE(struct inpcbinfo, udbinfo);
 142 static VNET_DEFINE(uma_zone_t, udpcb_zone);
 143 #define V_udpcb_zone                    VNET(udpcb_zone)
 144
 145 #ifndef UDBHASHSIZE
 146 #define UDBHASHSIZE     128
 147 #endif
 148
 149 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);          /* from udp_var.h */
 150 VNET_PCPUSTAT_SYSINIT(udpstat);
 151 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
 152     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 153
 154 #ifdef VIMAGE
 155 VNET_PCPUSTAT_SYSUNINIT(udpstat);
 156 #endif /* VIMAGE */
 157 #ifdef INET
 158 static void     udp_detach(struct socket *so);
 159 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 160                     struct mbuf *, struct thread *);
 161 #endif
 162
 163 #ifdef IPSEC
 164 #ifdef IPSEC_NAT_T
 165 #define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
 166 #ifdef INET
 167 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
 168 #endif
 169 #endif /* IPSEC_NAT_T */
 170 #endif /* IPSEC */
 171
 172 static void
 173 udp_zone_change(void *tag)
 174 {
 175
 176         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 177         uma_zone_set_max(V_udpcb_zone, maxsockets);
 178 }
 179
 180 static int
 181 udp_inpcb_init(void *mem, int size, int flags)
 182 {
 183         struct inpcb *inp;
 184
 185         inp = mem;
 186         INP_LOCK_INIT(inp, "inp", "udpinp");
 187         return (0);
 188 }
 189
 190 void
 191 udp_init(void)
 192 {
 193
 194         in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
 195             "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE,
 196             IPI_HASHFIELDS_2TUPLE);
 197         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
 198             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 199         uma_zone_set_max(V_udpcb_zone, maxsockets);
 200         uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
 201         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 202             EVENTHANDLER_PRI_ANY);
 203 }
 204
 205 /*
 206  * Kernel module interface for updating udpstat.  The argument is an index
 207  * into udpstat treated as an array of u_long.  While this encodes the
 208  * general layout of udpstat into the caller, it doesn't encode its location,
 209  * so that future changes to add, for example, per-CPU stats support won't
 210  * cause binary compatibility problems for kernel modules.
 211  */
 212 void
 213 kmod_udpstat_inc(int statnum)
 214 {
 215
 216         counter_u64_add(VNET(udpstat)[statnum], 1);
 217 }
 218
 219 int
 220 udp_newudpcb(struct inpcb *inp)
 221 {
 222         struct udpcb *up;
 223
 224         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
 225         if (up == NULL)
 226                 return (ENOBUFS);
 227         inp->inp_ppcb = up;
 228         return (0);
 229 }
 230
 231 void
 232 udp_discardcb(struct udpcb *up)
 233 {
 234
 235         uma_zfree(V_udpcb_zone, up);
 236 }
 237
 238 #ifdef VIMAGE
 239 void
 240 udp_destroy(void)
 241 {
 242
 243         in_pcbinfo_destroy(&V_udbinfo);
 244         uma_zdestroy(V_udpcb_zone);
 245 }
 246 #endif
 247
 248 #ifdef INET
 249 /*
 250  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 251  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 252  * contains the source address.  If the socket ends up being an IPv6 socket,
 253  * udp_append() will convert to a sockaddr_in6 before passing the address
 254  * into the socket code.
 255  */
 256 static void
 257 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 258     struct sockaddr_in *udp_in)
 259 {
 260         struct sockaddr *append_sa;
 261         struct socket *so;
 262         struct mbuf *opts = 0;
 263 #ifdef INET6
 264         struct sockaddr_in6 udp_in6;
 265 #endif
 266         struct udpcb *up;
 267
 268         INP_LOCK_ASSERT(inp);
 269
 270         /*
 271          * Engage the tunneling protocol.
 272          */
 273         up = intoudpcb(inp);
 274         if (up->u_tun_func != NULL) {
 275                 (*up->u_tun_func)(n, off, inp);
 276                 return;
 277         }
 278
 279         if (n == NULL)
 280                 return;
 281
 282         off += sizeof(struct udphdr);
 283
 284 #ifdef IPSEC
 285         /* Check AH/ESP integrity. */
 286         if (ipsec4_in_reject(n, inp)) {
 287                 m_freem(n);
 288                 IPSECSTAT_INC(ips_in_polvio);
 289                 return;
 290         }
 291 #ifdef IPSEC_NAT_T
 292         up = intoudpcb(inp);
 293         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
 294         if (up->u_flags & UF_ESPINUDP_ALL) {    /* IPSec UDP encaps. */
 295                 n = udp4_espdecap(inp, n, off);
 296                 if (n == NULL)                          /* Consumed. */
 297                         return;
 298         }
 299 #endif /* IPSEC_NAT_T */
 300 #endif /* IPSEC */
 301 #ifdef MAC
 302         if (mac_inpcb_check_deliver(inp, n) != 0) {
 303                 m_freem(n);
 304                 return;
 305         }
 306 #endif /* MAC */
 307         if (inp->inp_flags & INP_CONTROLOPTS ||
 308             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 309 #ifdef INET6
 310                 if (inp->inp_vflag & INP_IPV6)
 311                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
 312                 else
 313 #endif /* INET6 */
 314                         ip_savecontrol(inp, &opts, ip, n);
 315         }
 316 #ifdef INET6
 317         if (inp->inp_vflag & INP_IPV6) {
 318                 bzero(&udp_in6, sizeof(udp_in6));
 319                 udp_in6.sin6_len = sizeof(udp_in6);
 320                 udp_in6.sin6_family = AF_INET6;
 321                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 322                 append_sa = (struct sockaddr *)&udp_in6;
 323         } else
 324 #endif /* INET6 */
 325                 append_sa = (struct sockaddr *)udp_in;
 326         m_adj(n, off);
 327
 328         so = inp->inp_socket;
 329         SOCKBUF_LOCK(&so->so_rcv);
 330         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 331                 SOCKBUF_UNLOCK(&so->so_rcv);
 332                 m_freem(n);
 333                 if (opts)
 334                         m_freem(opts);
 335                 UDPSTAT_INC(udps_fullsock);
 336         } else
 337                 sorwakeup_locked(so);
 338 }
 339
 340 void
 341 udp_input(struct mbuf *m, int off)
 342 {
 343         int iphlen = off;
 344         struct ip *ip;
 345         struct udphdr *uh;
 346         struct ifnet *ifp;
 347         struct inpcb *inp;
 348         uint16_t len, ip_len;
 349         struct ip save_ip;
 350         struct sockaddr_in udp_in;
 351         struct m_tag *fwd_tag;
 352
 353         ifp = m->m_pkthdr.rcvif;
 354         UDPSTAT_INC(udps_ipackets);
 355
 356         /*
 357          * Strip IP options, if any; should skip this, make available to
 358          * user, and use on returned packets, but we don't yet have a way to
 359          * check the checksum with options still present.
 360          */
 361         if (iphlen > sizeof (struct ip)) {
 362                 ip_stripoptions(m);
 363                 iphlen = sizeof(struct ip);
 364         }
 365
 366         /*
 367          * Get IP and UDP header together in first mbuf.
 368          */
 369         ip = mtod(m, struct ip *);
 370         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 371                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 372                         UDPSTAT_INC(udps_hdrops);
 373                         return;
 374                 }
 375                 ip = mtod(m, struct ip *);
 376         }
 377         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 378
 379         /*
 380          * Destination port of 0 is illegal, based on RFC768.
 381          */
 382         if (uh->uh_dport == 0)
 383                 goto badunlocked;
 384
 385         /*
 386          * Construct sockaddr format source address.  Stuff source address
 387          * and datagram in user buffer.
 388          */
 389         bzero(&udp_in, sizeof(udp_in));
 390         udp_in.sin_len = sizeof(udp_in);
 391         udp_in.sin_family = AF_INET;
 392         udp_in.sin_port = uh->uh_sport;
 393         udp_in.sin_addr = ip->ip_src;
 394
 395         /*
 396          * Make mbuf data length reflect UDP length.  If not enough data to
 397          * reflect UDP length, drop.
 398          */
 399         len = ntohs((u_short)uh->uh_ulen);
 400         ip_len = ntohs(ip->ip_len) - iphlen;
 401         if (ip_len != len) {
 402                 if (len > ip_len || len < sizeof(struct udphdr)) {
 403                         UDPSTAT_INC(udps_badlen);
 404                         goto badunlocked;
 405                 }
 406                 m_adj(m, len - ip_len);
 407         }
 408
 409         /*
 410          * Save a copy of the IP header in case we want restore it for
 411          * sending an ICMP error message in response.
 412          */
 413         if (!V_udp_blackhole)
 414                 save_ip = *ip;
 415         else
 416                 memset(&save_ip, 0, sizeof(save_ip));
 417
 418         /*
 419          * Checksum extended UDP header and data.
 420          */
 421         if (uh->uh_sum) {
 422                 u_short uh_sum;
 423
 424                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 425                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 426                                 uh_sum = m->m_pkthdr.csum_data;
 427                         else
 428                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 429                                     ip->ip_dst.s_addr, htonl((u_short)len +
 430                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 431                         uh_sum ^= 0xffff;
 432                 } else {
 433                         char b[9];
 434
 435                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 436                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 437                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 438                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 439                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 440                 }
 441                 if (uh_sum) {
 442                         UDPSTAT_INC(udps_badsum);
 443                         m_freem(m);
 444                         return;
 445                 }
 446         } else
 447                 UDPSTAT_INC(udps_nosum);
 448
 449         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 450             in_broadcast(ip->ip_dst, ifp)) {
 451                 struct inpcb *last;
 452                 struct ip_moptions *imo;
 453
 454                 INP_INFO_RLOCK(&V_udbinfo);
 455                 last = NULL;
 456                 LIST_FOREACH(inp, &V_udb, inp_list) {
 457                         if (inp->inp_lport != uh->uh_dport)
 458                                 continue;
 459 #ifdef INET6
 460                         if ((inp->inp_vflag & INP_IPV4) == 0)
 461                                 continue;
 462 #endif
 463                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 464                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 465                                 continue;
 466                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 467                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 468                                 continue;
 469                         if (inp->inp_fport != 0 &&
 470                             inp->inp_fport != uh->uh_sport)
 471                                 continue;
 472
 473                         INP_RLOCK(inp);
 474
 475                         /*
 476                          * XXXRW: Because we weren't holding either the inpcb
 477                          * or the hash lock when we checked for a match
 478                          * before, we should probably recheck now that the
 479                          * inpcb lock is held.
 480                          */
 481
 482                         /*
 483                          * Handle socket delivery policy for any-source
 484                          * and source-specific multicast. [RFC3678]
 485                          */
 486                         imo = inp->inp_moptions;
 487                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 488                                 struct sockaddr_in       group;
 489                                 int                      blocked;
 490                                 if (imo == NULL) {
 491                                         INP_RUNLOCK(inp);
 492                                         continue;
 493                                 }
 494                                 bzero(&group, sizeof(struct sockaddr_in));
 495                                 group.sin_len = sizeof(struct sockaddr_in);
 496                                 group.sin_family = AF_INET;
 497                                 group.sin_addr = ip->ip_dst;
 498
 499                                 blocked = imo_multi_filter(imo, ifp,
 500                                         (struct sockaddr *)&group,
 501                                         (struct sockaddr *)&udp_in);
 502                                 if (blocked != MCAST_PASS) {
 503                                         if (blocked == MCAST_NOTGMEMBER)
 504                                                 IPSTAT_INC(ips_notmember);
 505                                         if (blocked == MCAST_NOTSMEMBER ||
 506                                             blocked == MCAST_MUTED)
 507                                                 UDPSTAT_INC(udps_filtermcast);
 508                                         INP_RUNLOCK(inp);
 509                                         continue;
 510                                 }
 511                         }
 512                         if (last != NULL) {
 513                                 struct mbuf *n;
 514
 515                                 n = m_copy(m, 0, M_COPYALL);
 516                                 udp_append(last, ip, n, iphlen, &udp_in);
 517                                 INP_RUNLOCK(last);
 518                         }
 519                         last = inp;
 520                         /*
 521                          * Don't look for additional matches if this one does
 522                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 523                          * socket options set.  This heuristic avoids
 524                          * searching through all pcbs in the common case of a
 525                          * non-shared port.  It assumes that an application
 526                          * will never clear these options after setting them.
 527                          */
 528                         if ((last->inp_socket->so_options &
 529                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 530                                 break;
 531                 }
 532
 533                 if (last == NULL) {
 534                         /*
 535                          * No matching pcb found; discard datagram.  (No need
 536                          * to send an ICMP Port Unreachable for a broadcast
 537                          * or multicast datgram.)
 538                          */
 539                         UDPSTAT_INC(udps_noportbcast);
 540                         if (inp)
 541                                 INP_RUNLOCK(inp);
 542                         INP_INFO_RUNLOCK(&V_udbinfo);
 543                         goto badunlocked;
 544                 }
 545                 udp_append(last, ip, m, iphlen, &udp_in);
 546                 INP_RUNLOCK(last);
 547                 INP_INFO_RUNLOCK(&V_udbinfo);
 548                 return;
 549         }
 550
 551         /*
 552          * Locate pcb for datagram.
 553          */
 554
 555         /*
 556          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 557          */
 558         if ((m->m_flags & M_IP_NEXTHOP) &&
 559             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 560                 struct sockaddr_in *next_hop;
 561
 562                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 563
 564                 /*
 565                  * Transparently forwarded. Pretend to be the destination.
 566                  * Already got one like this?
 567                  */
 568                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 569                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
 570                 if (!inp) {
 571                         /*
 572                          * It's new.  Try to find the ambushing socket.
 573                          * Because we've rewritten the destination address,
 574                          * any hardware-generated hash is ignored.
 575                          */
 576                         inp = in_pcblookup(&V_udbinfo, ip->ip_src,
 577                             uh->uh_sport, next_hop->sin_addr,
 578                             next_hop->sin_port ? htons(next_hop->sin_port) :
 579                             uh->uh_dport, INPLOOKUP_WILDCARD |
 580                             INPLOOKUP_RLOCKPCB, ifp);
 581                 }
 582                 /* Remove the tag from the packet. We don't need it anymore. */
 583                 m_tag_delete(m, fwd_tag);
 584                 m->m_flags &= ~M_IP_NEXTHOP;
 585         } else
 586                 inp = in_pcblookup_mbuf(&V_udbinfo, ip->ip_src, uh->uh_sport,
 587                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
 588                     INPLOOKUP_RLOCKPCB, ifp, m);
 589         if (inp == NULL) {
 590                 if (udp_log_in_vain) {
 591                         char buf[4*sizeof "123"];
 592
 593                         strcpy(buf, inet_ntoa(ip->ip_dst));
 594                         log(LOG_INFO,
 595                             "Connection attempt to UDP %s:%d from %s:%d\n",
 596                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 597                             ntohs(uh->uh_sport));
 598                 }
 599                 UDPSTAT_INC(udps_noport);
 600                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 601                         UDPSTAT_INC(udps_noportbcast);
 602                         goto badunlocked;
 603                 }
 604                 if (V_udp_blackhole)
 605                         goto badunlocked;
 606                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 607                         goto badunlocked;
 608                 *ip = save_ip;
 609                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 610                 return;
 611         }
 612
 613         /*
 614          * Check the minimum TTL for socket.
 615          */
 616         INP_RLOCK_ASSERT(inp);
 617         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 618                 INP_RUNLOCK(inp);
 619                 m_freem(m);
 620                 return;
 621         }
 622
 623         UDP_PROBE(receive, NULL, inp, ip, inp, uh);
 624         udp_append(inp, ip, m, iphlen, &udp_in);
 625         INP_RUNLOCK(inp);
 626         return;
 627
 628 badunlocked:
 629         m_freem(m);
 630 }
 631 #endif /* INET */
 632
 633 /*
 634  * Notify a udp user of an asynchronous error; just wake up so that they can
 635  * collect error status.
 636  */
 637 struct inpcb *
 638 udp_notify(struct inpcb *inp, int errno)
 639 {
 640
 641         /*
 642          * While udp_ctlinput() always calls udp_notify() with a read lock
 643          * when invoking it directly, in_pcbnotifyall() currently uses write
 644          * locks due to sharing code with TCP.  For now, accept either a read
 645          * or a write lock, but a read lock is sufficient.
 646          */
 647         INP_LOCK_ASSERT(inp);
 648
 649         inp->inp_socket->so_error = errno;
 650         sorwakeup(inp->inp_socket);
 651         sowwakeup(inp->inp_socket);
 652         return (inp);
 653 }
 654
 655 #ifdef INET
 656 void
 657 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 658 {
 659         struct ip *ip = vip;
 660         struct udphdr *uh;
 661         struct in_addr faddr;
 662         struct inpcb *inp;
 663
 664         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 665         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 666                 return;
 667
 668         /*
 669          * Redirects don't need to be handled up here.
 670          */
 671         if (PRC_IS_REDIRECT(cmd))
 672                 return;
 673
 674         /*
 675          * Hostdead is ugly because it goes linearly through all PCBs.
 676          *
 677          * XXX: We never get this from ICMP, otherwise it makes an excellent
 678          * DoS attack on machines with many connections.
 679          */
 680         if (cmd == PRC_HOSTDEAD)
 681                 ip = NULL;
 682         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 683                 return;
 684         if (ip != NULL) {
 685                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 686                 inp = in_pcblookup(&V_udbinfo, faddr, uh->uh_dport,
 687                     ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
 688                 if (inp != NULL) {
 689                         INP_RLOCK_ASSERT(inp);
 690                         if (inp->inp_socket != NULL) {
 691                                 udp_notify(inp, inetctlerrmap[cmd]);
 692                         }
 693                         INP_RUNLOCK(inp);
 694                 }
 695         } else
 696                 in_pcbnotifyall(&V_udbinfo, faddr, inetctlerrmap[cmd],
 697                     udp_notify);
 698 }
 699 #endif /* INET */
 700
 701 static int
 702 udp_pcblist(SYSCTL_HANDLER_ARGS)
 703 {
 704         int error, i, n;
 705         struct inpcb *inp, **inp_list;
 706         inp_gen_t gencnt;
 707         struct xinpgen xig;
 708
 709         /*
 710          * The process of preparing the PCB list is too time-consuming and
 711          * resource-intensive to repeat twice on every request.
 712          */
 713         if (req->oldptr == 0) {
 714                 n = V_udbinfo.ipi_count;
 715                 n += imax(n / 8, 10);
 716                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 717                 return (0);
 718         }
 719
 720         if (req->newptr != 0)
 721                 return (EPERM);
 722
 723         /*
 724          * OK, now we're committed to doing something.
 725          */
 726         INP_INFO_RLOCK(&V_udbinfo);
 727         gencnt = V_udbinfo.ipi_gencnt;
 728         n = V_udbinfo.ipi_count;
 729         INP_INFO_RUNLOCK(&V_udbinfo);
 730
 731         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 732                 + n * sizeof(struct xinpcb));
 733         if (error != 0)
 734                 return (error);
 735
 736         xig.xig_len = sizeof xig;
 737         xig.xig_count = n;
 738         xig.xig_gen = gencnt;
 739         xig.xig_sogen = so_gencnt;
 740         error = SYSCTL_OUT(req, &xig, sizeof xig);
 741         if (error)
 742                 return (error);
 743
 744         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 745         if (inp_list == 0)
 746                 return (ENOMEM);
 747
 748         INP_INFO_RLOCK(&V_udbinfo);
 749         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
 750              inp = LIST_NEXT(inp, inp_list)) {
 751                 INP_WLOCK(inp);
 752                 if (inp->inp_gencnt <= gencnt &&
 753                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
 754                         in_pcbref(inp);
 755                         inp_list[i++] = inp;
 756                 }
 757                 INP_WUNLOCK(inp);
 758         }
 759         INP_INFO_RUNLOCK(&V_udbinfo);
 760         n = i;
 761
 762         error = 0;
 763         for (i = 0; i < n; i++) {
 764                 inp = inp_list[i];
 765                 INP_RLOCK(inp);
 766                 if (inp->inp_gencnt <= gencnt) {
 767                         struct xinpcb xi;
 768
 769                         bzero(&xi, sizeof(xi));
 770                         xi.xi_len = sizeof xi;
 771                         /* XXX should avoid extra copy */
 772                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 773                         if (inp->inp_socket)
 774                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 775                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 776                         INP_RUNLOCK(inp);
 777                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 778                 } else
 779                         INP_RUNLOCK(inp);
 780         }
 781         INP_INFO_WLOCK(&V_udbinfo);
 782         for (i = 0; i < n; i++) {
 783                 inp = inp_list[i];
 784                 INP_RLOCK(inp);
 785                 if (!in_pcbrele_rlocked(inp))
 786                         INP_RUNLOCK(inp);
 787         }
 788         INP_INFO_WUNLOCK(&V_udbinfo);
 789
 790         if (!error) {
 791                 /*
 792                  * Give the user an updated idea of our state.  If the
 793                  * generation differs from what we told her before, she knows
 794                  * that something happened while we were processing this
 795                  * request, and it might be necessary to retry.
 796                  */
 797                 INP_INFO_RLOCK(&V_udbinfo);
 798                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 799                 xig.xig_sogen = so_gencnt;
 800                 xig.xig_count = V_udbinfo.ipi_count;
 801                 INP_INFO_RUNLOCK(&V_udbinfo);
 802                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 803         }
 804         free(inp_list, M_TEMP);
 805         return (error);
 806 }
 807
 808 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
 809     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
 810     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 811
 812 #ifdef INET
 813 static int
 814 udp_getcred(SYSCTL_HANDLER_ARGS)
 815 {
 816         struct xucred xuc;
 817         struct sockaddr_in addrs[2];
 818         struct inpcb *inp;
 819         int error;
 820
 821         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 822         if (error)
 823                 return (error);
 824         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 825         if (error)
 826                 return (error);
 827         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 828             addrs[0].sin_addr, addrs[0].sin_port,
 829             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 830         if (inp != NULL) {
 831                 INP_RLOCK_ASSERT(inp);
 832                 if (inp->inp_socket == NULL)
 833                         error = ENOENT;
 834                 if (error == 0)
 835                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 836                 if (error == 0)
 837                         cru2x(inp->inp_cred, &xuc);
 838                 INP_RUNLOCK(inp);
 839         } else
 840                 error = ENOENT;
 841         if (error == 0)
 842                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 843         return (error);
 844 }
 845
 846 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 847     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 848     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 849 #endif /* INET */
 850
 851 int
 852 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 853 {
 854         int error = 0, optval;
 855         struct inpcb *inp;
 856 #ifdef IPSEC_NAT_T
 857         struct udpcb *up;
 858 #endif
 859
 860         inp = sotoinpcb(so);
 861         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 862         INP_WLOCK(inp);
 863         if (sopt->sopt_level != IPPROTO_UDP) {
 864 #ifdef INET6
 865                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 866                         INP_WUNLOCK(inp);
 867                         error = ip6_ctloutput(so, sopt);
 868                 }
 869 #endif
 870 #if defined(INET) && defined(INET6)
 871                 else
 872 #endif
 873 #ifdef INET
 874                 {
 875                         INP_WUNLOCK(inp);
 876                         error = ip_ctloutput(so, sopt);
 877                 }
 878 #endif
 879                 return (error);
 880         }
 881
 882         switch (sopt->sopt_dir) {
 883         case SOPT_SET:
 884                 switch (sopt->sopt_name) {
 885                 case UDP_ENCAP:
 886                         INP_WUNLOCK(inp);
 887                         error = sooptcopyin(sopt, &optval, sizeof optval,
 888                                             sizeof optval);
 889                         if (error)
 890                                 break;
 891                         inp = sotoinpcb(so);
 892                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 893                         INP_WLOCK(inp);
 894 #ifdef IPSEC_NAT_T
 895                         up = intoudpcb(inp);
 896                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 897 #endif
 898                         switch (optval) {
 899                         case 0:
 900                                 /* Clear all UDP encap. */
 901 #ifdef IPSEC_NAT_T
 902                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 903 #endif
 904                                 break;
 905 #ifdef IPSEC_NAT_T
 906                         case UDP_ENCAP_ESPINUDP:
 907                         case UDP_ENCAP_ESPINUDP_NON_IKE:
 908                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 909                                 if (optval == UDP_ENCAP_ESPINUDP)
 910                                         up->u_flags |= UF_ESPINUDP;
 911                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
 912                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
 913                                 break;
 914 #endif
 915                         default:
 916                                 error = EINVAL;
 917                                 break;
 918                         }
 919                         INP_WUNLOCK(inp);
 920                         break;
 921                 default:
 922                         INP_WUNLOCK(inp);
 923                         error = ENOPROTOOPT;
 924                         break;
 925                 }
 926                 break;
 927         case SOPT_GET:
 928                 switch (sopt->sopt_name) {
 929 #ifdef IPSEC_NAT_T
 930                 case UDP_ENCAP:
 931                         up = intoudpcb(inp);
 932                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 933                         optval = up->u_flags & UF_ESPINUDP_ALL;
 934                         INP_WUNLOCK(inp);
 935                         error = sooptcopyout(sopt, &optval, sizeof optval);
 936                         break;
 937 #endif
 938                 default:
 939                         INP_WUNLOCK(inp);
 940                         error = ENOPROTOOPT;
 941                         break;
 942                 }
 943                 break;
 944         }
 945         return (error);
 946 }
 947
 948 #ifdef INET
 949 #define UH_WLOCKED      2
 950 #define UH_RLOCKED      1
 951 #define UH_UNLOCKED     0
 952 static int
 953 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
 954     struct mbuf *control, struct thread *td)
 955 {
 956         struct udpiphdr *ui;
 957         int len = m->m_pkthdr.len;
 958         struct in_addr faddr, laddr;
 959         struct cmsghdr *cm;
 960         struct sockaddr_in *sin, src;
 961         int error = 0;
 962         int ipflags;
 963         u_short fport, lport;
 964         int unlock_udbinfo;
 965         u_char tos;
 966
 967         /*
 968          * udp_output() may need to temporarily bind or connect the current
 969          * inpcb.  As such, we don't know up front whether we will need the
 970          * pcbinfo lock or not.  Do any work to decide what is needed up
 971          * front before acquiring any locks.
 972          */
 973         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 974                 if (control)
 975                         m_freem(control);
 976                 m_freem(m);
 977                 return (EMSGSIZE);
 978         }
 979
 980         src.sin_family = 0;
 981         INP_RLOCK(inp);
 982         tos = inp->inp_ip_tos;
 983         if (control != NULL) {
 984                 /*
 985                  * XXX: Currently, we assume all the optional information is
 986                  * stored in a single mbuf.
 987                  */
 988                 if (control->m_next) {
 989                         INP_RUNLOCK(inp);
 990                         m_freem(control);
 991                         m_freem(m);
 992                         return (EINVAL);
 993                 }
 994                 for (; control->m_len > 0;
 995                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 996                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 997                         cm = mtod(control, struct cmsghdr *);
 998                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
 999                             || cm->cmsg_len > control->m_len) {
1000                                 error = EINVAL;
1001                                 break;
1002                         }
1003                         if (cm->cmsg_level != IPPROTO_IP)
1004                                 continue;
1005
1006                         switch (cm->cmsg_type) {
1007                         case IP_SENDSRCADDR:
1008                                 if (cm->cmsg_len !=
1009                                     CMSG_LEN(sizeof(struct in_addr))) {
1010                                         error = EINVAL;
1011                                         break;
1012                                 }
1013                                 bzero(&src, sizeof(src));
1014                                 src.sin_family = AF_INET;
1015                                 src.sin_len = sizeof(src);
1016                                 src.sin_port = inp->inp_lport;
1017                                 src.sin_addr =
1018                                     *(struct in_addr *)CMSG_DATA(cm);
1019                                 break;
1020
1021                         case IP_TOS:
1022                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1023                                         error = EINVAL;
1024                                         break;
1025                                 }
1026                                 tos = *(u_char *)CMSG_DATA(cm);
1027                                 break;
1028
1029                         default:
1030                                 error = ENOPROTOOPT;
1031                                 break;
1032                         }
1033                         if (error)
1034                                 break;
1035                 }
1036                 m_freem(control);
1037         }
1038         if (error) {
1039                 INP_RUNLOCK(inp);
1040                 m_freem(m);
1041                 return (error);
1042         }
1043
1044         /*
1045          * Depending on whether or not the application has bound or connected
1046          * the socket, we may have to do varying levels of work.  The optimal
1047          * case is for a connected UDP socket, as a global lock isn't
1048          * required at all.
1049          *
1050          * In order to decide which we need, we require stability of the
1051          * inpcb binding, which we ensure by acquiring a read lock on the
1052          * inpcb.  This doesn't strictly follow the lock order, so we play
1053          * the trylock and retry game; note that we may end up with more
1054          * conservative locks than required the second time around, so later
1055          * assertions have to accept that.  Further analysis of the number of
1056          * misses under contention is required.
1057          *
1058          * XXXRW: Check that hash locking update here is correct.
1059          */
1060         sin = (struct sockaddr_in *)addr;
1061         if (sin != NULL &&
1062             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1063                 INP_RUNLOCK(inp);
1064                 INP_WLOCK(inp);
1065                 INP_HASH_WLOCK(&V_udbinfo);
1066                 unlock_udbinfo = UH_WLOCKED;
1067         } else if ((sin != NULL && (
1068             (sin->sin_addr.s_addr == INADDR_ANY) ||
1069             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1070             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1071             (inp->inp_lport == 0))) ||
1072             (src.sin_family == AF_INET)) {
1073                 INP_HASH_RLOCK(&V_udbinfo);
1074                 unlock_udbinfo = UH_RLOCKED;
1075         } else
1076                 unlock_udbinfo = UH_UNLOCKED;
1077
1078         /*
1079          * If the IP_SENDSRCADDR control message was specified, override the
1080          * source address for this datagram.  Its use is invalidated if the
1081          * address thus specified is incomplete or clobbers other inpcbs.
1082          */
1083         laddr = inp->inp_laddr;
1084         lport = inp->inp_lport;
1085         if (src.sin_family == AF_INET) {
1086                 INP_HASH_LOCK_ASSERT(&V_udbinfo);
1087                 if ((lport == 0) ||
1088                     (laddr.s_addr == INADDR_ANY &&
1089                      src.sin_addr.s_addr == INADDR_ANY)) {
1090                         error = EINVAL;
1091                         goto release;
1092                 }
1093                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1094                     &laddr.s_addr, &lport, td->td_ucred);
1095                 if (error)
1096                         goto release;
1097         }
1098
1099         /*
1100          * If a UDP socket has been connected, then a local address/port will
1101          * have been selected and bound.
1102          *
1103          * If a UDP socket has not been connected to, then an explicit
1104          * destination address must be used, in which case a local
1105          * address/port may not have been selected and bound.
1106          */
1107         if (sin != NULL) {
1108                 INP_LOCK_ASSERT(inp);
1109                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1110                         error = EISCONN;
1111                         goto release;
1112                 }
1113
1114                 /*
1115                  * Jail may rewrite the destination address, so let it do
1116                  * that before we use it.
1117                  */
1118                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1119                 if (error)
1120                         goto release;
1121
1122                 /*
1123                  * If a local address or port hasn't yet been selected, or if
1124                  * the destination address needs to be rewritten due to using
1125                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1126                  * to do the heavy lifting.  Once a port is selected, we
1127                  * commit the binding back to the socket; we also commit the
1128                  * binding of the address if in jail.
1129                  *
1130                  * If we already have a valid binding and we're not
1131                  * requesting a destination address rewrite, use a fast path.
1132                  */
1133                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1134                     inp->inp_lport == 0 ||
1135                     sin->sin_addr.s_addr == INADDR_ANY ||
1136                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1137                         INP_HASH_LOCK_ASSERT(&V_udbinfo);
1138                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1139                             &lport, &faddr.s_addr, &fport, NULL,
1140                             td->td_ucred);
1141                         if (error)
1142                                 goto release;
1143
1144                         /*
1145                          * XXXRW: Why not commit the port if the address is
1146                          * !INADDR_ANY?
1147                          */
1148                         /* Commit the local port if newly assigned. */
1149                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1150                             inp->inp_lport == 0) {
1151                                 INP_WLOCK_ASSERT(inp);
1152                                 INP_HASH_WLOCK_ASSERT(&V_udbinfo);
1153                                 /*
1154                                  * Remember addr if jailed, to prevent
1155                                  * rebinding.
1156                                  */
1157                                 if (prison_flag(td->td_ucred, PR_IP4))
1158                                         inp->inp_laddr = laddr;
1159                                 inp->inp_lport = lport;
1160                                 if (in_pcbinshash(inp) != 0) {
1161                                         inp->inp_lport = 0;
1162                                         error = EAGAIN;
1163                                         goto release;
1164                                 }
1165                                 inp->inp_flags |= INP_ANONPORT;
1166                         }
1167                 } else {
1168                         faddr = sin->sin_addr;
1169                         fport = sin->sin_port;
1170                 }
1171         } else {
1172                 INP_LOCK_ASSERT(inp);
1173                 faddr = inp->inp_faddr;
1174                 fport = inp->inp_fport;
1175                 if (faddr.s_addr == INADDR_ANY) {
1176                         error = ENOTCONN;
1177                         goto release;
1178                 }
1179         }
1180
1181         /*
1182          * Calculate data length and get a mbuf for UDP, IP, and possible
1183          * link-layer headers.  Immediate slide the data pointer back forward
1184          * since we won't use that space at this layer.
1185          */
1186         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1187         if (m == NULL) {
1188                 error = ENOBUFS;
1189                 goto release;
1190         }
1191         m->m_data += max_linkhdr;
1192         m->m_len -= max_linkhdr;
1193         m->m_pkthdr.len -= max_linkhdr;
1194
1195         /*
1196          * Fill in mbuf with extended UDP header and addresses and length put
1197          * into network format.
1198          */
1199         ui = mtod(m, struct udpiphdr *);
1200         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1201         ui->ui_v = IPVERSION << 4;
1202         ui->ui_pr = IPPROTO_UDP;
1203         ui->ui_src = laddr;
1204         ui->ui_dst = faddr;
1205         ui->ui_sport = lport;
1206         ui->ui_dport = fport;
1207         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1208
1209         /*
1210          * Set the Don't Fragment bit in the IP header.
1211          */
1212         if (inp->inp_flags & INP_DONTFRAG) {
1213                 struct ip *ip;
1214
1215                 ip = (struct ip *)&ui->ui_i;
1216                 ip->ip_off |= htons(IP_DF);
1217         }
1218
1219         ipflags = 0;
1220         if (inp->inp_socket->so_options & SO_DONTROUTE)
1221                 ipflags |= IP_ROUTETOIF;
1222         if (inp->inp_socket->so_options & SO_BROADCAST)
1223                 ipflags |= IP_ALLOWBROADCAST;
1224         if (inp->inp_flags & INP_ONESBCAST)
1225                 ipflags |= IP_SENDONES;
1226
1227 #ifdef MAC
1228         mac_inpcb_create_mbuf(inp, m);
1229 #endif
1230
1231         /*
1232          * Set up checksum and output datagram.
1233          */
1234         if (V_udp_cksum) {
1235                 if (inp->inp_flags & INP_ONESBCAST)
1236                         faddr.s_addr = INADDR_BROADCAST;
1237                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1238                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
1239                 m->m_pkthdr.csum_flags = CSUM_UDP;
1240                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1241         } else
1242                 ui->ui_sum = 0;
1243         ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1244         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1245         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1246         UDPSTAT_INC(udps_opackets);
1247
1248         if (unlock_udbinfo == UH_WLOCKED)
1249                 INP_HASH_WUNLOCK(&V_udbinfo);
1250         else if (unlock_udbinfo == UH_RLOCKED)
1251                 INP_HASH_RUNLOCK(&V_udbinfo);
1252         UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1253         error = ip_output(m, inp->inp_options, NULL, ipflags,
1254             inp->inp_moptions, inp);
1255         if (unlock_udbinfo == UH_WLOCKED)
1256                 INP_WUNLOCK(inp);
1257         else
1258                 INP_RUNLOCK(inp);
1259         return (error);
1260
1261 release:
1262         if (unlock_udbinfo == UH_WLOCKED) {
1263                 INP_HASH_WUNLOCK(&V_udbinfo);
1264                 INP_WUNLOCK(inp);
1265         } else if (unlock_udbinfo == UH_RLOCKED) {
1266                 INP_HASH_RUNLOCK(&V_udbinfo);
1267                 INP_RUNLOCK(inp);
1268         } else
1269                 INP_RUNLOCK(inp);
1270         m_freem(m);
1271         return (error);
1272 }
1273
1274
1275 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1276 /*
1277  * Potentially decap ESP in UDP frame.  Check for an ESP header
1278  * and optional marker; if present, strip the UDP header and
1279  * push the result through IPSec.
1280  *
1281  * Returns mbuf to be processed (potentially re-allocated) or
1282  * NULL if consumed and/or processed.
1283  */
1284 static struct mbuf *
1285 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1286 {
1287         size_t minlen, payload, skip, iphlen;
1288         caddr_t data;
1289         struct udpcb *up;
1290         struct m_tag *tag;
1291         struct udphdr *udphdr;
1292         struct ip *ip;
1293
1294         INP_RLOCK_ASSERT(inp);
1295
1296         /*
1297          * Pull up data so the longest case is contiguous:
1298          *    IP/UDP hdr + non ESP marker + ESP hdr.
1299          */
1300         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1301         if (minlen > m->m_pkthdr.len)
1302                 minlen = m->m_pkthdr.len;
1303         if ((m = m_pullup(m, minlen)) == NULL) {
1304                 IPSECSTAT_INC(ips_in_inval);
1305                 return (NULL);          /* Bypass caller processing. */
1306         }
1307         data = mtod(m, caddr_t);        /* Points to ip header. */
1308         payload = m->m_len - off;       /* Size of payload. */
1309
1310         if (payload == 1 && data[off] == '\xff')
1311                 return (m);             /* NB: keepalive packet, no decap. */
1312
1313         up = intoudpcb(inp);
1314         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1315         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1316             ("u_flags 0x%x", up->u_flags));
1317
1318         /*
1319          * Check that the payload is large enough to hold an
1320          * ESP header and compute the amount of data to remove.
1321          *
1322          * NB: the caller has already done a pullup for us.
1323          * XXX can we assume alignment and eliminate bcopys?
1324          */
1325         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1326                 /*
1327                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1328                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1329                  * possible AH mode non-IKE marker+non-ESP marker
1330                  * from draft-ietf-ipsec-udp-encaps-00.txt.
1331                  */
1332                 uint64_t marker;
1333
1334                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1335                         return (m);     /* NB: no decap. */
1336                 bcopy(data + off, &marker, sizeof(uint64_t));
1337                 if (marker != 0)        /* Non-IKE marker. */
1338                         return (m);     /* NB: no decap. */
1339                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1340         } else {
1341                 uint32_t spi;
1342
1343                 if (payload <= sizeof(struct esp)) {
1344                         IPSECSTAT_INC(ips_in_inval);
1345                         m_freem(m);
1346                         return (NULL);  /* Discard. */
1347                 }
1348                 bcopy(data + off, &spi, sizeof(uint32_t));
1349                 if (spi == 0)           /* Non-ESP marker. */
1350                         return (m);     /* NB: no decap. */
1351                 skip = sizeof(struct udphdr);
1352         }
1353
1354         /*
1355          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1356          * the UDP ports. This is required if we want to select
1357          * the right SPD for multiple hosts behind same NAT.
1358          *
1359          * NB: ports are maintained in network byte order everywhere
1360          *     in the NAT-T code.
1361          */
1362         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1363                 2 * sizeof(uint16_t), M_NOWAIT);
1364         if (tag == NULL) {
1365                 IPSECSTAT_INC(ips_in_nomem);
1366                 m_freem(m);
1367                 return (NULL);          /* Discard. */
1368         }
1369         iphlen = off - sizeof(struct udphdr);
1370         udphdr = (struct udphdr *)(data + iphlen);
1371         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1372         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1373         m_tag_prepend(m, tag);
1374
1375         /*
1376          * Remove the UDP header (and possibly the non ESP marker)
1377          * IP header length is iphlen
1378          * Before:
1379          *   <--- off --->
1380          *   +----+------+-----+
1381          *   | IP |  UDP | ESP |
1382          *   +----+------+-----+
1383          *        <-skip->
1384          * After:
1385          *          +----+-----+
1386          *          | IP | ESP |
1387          *          +----+-----+
1388          *   <-skip->
1389          */
1390         ovbcopy(data, data + skip, iphlen);
1391         m_adj(m, skip);
1392
1393         ip = mtod(m, struct ip *);
1394         ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1395         ip->ip_p = IPPROTO_ESP;
1396
1397         /*
1398          * We cannot yet update the cksums so clear any
1399          * h/w cksum flags as they are no longer valid.
1400          */
1401         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1402                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1403
1404         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1405         return (NULL);                  /* NB: consumed, bypass processing. */
1406 }
1407 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1408
1409 static void
1410 udp_abort(struct socket *so)
1411 {
1412         struct inpcb *inp;
1413
1414         inp = sotoinpcb(so);
1415         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1416         INP_WLOCK(inp);
1417         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1418                 INP_HASH_WLOCK(&V_udbinfo);
1419                 in_pcbdisconnect(inp);
1420                 inp->inp_laddr.s_addr = INADDR_ANY;
1421                 INP_HASH_WUNLOCK(&V_udbinfo);
1422                 soisdisconnected(so);
1423         }
1424         INP_WUNLOCK(inp);
1425 }
1426
1427 static int
1428 udp_attach(struct socket *so, int proto, struct thread *td)
1429 {
1430         struct inpcb *inp;
1431         int error;
1432
1433         inp = sotoinpcb(so);
1434         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1435         error = soreserve(so, udp_sendspace, udp_recvspace);
1436         if (error)
1437                 return (error);
1438         INP_INFO_WLOCK(&V_udbinfo);
1439         error = in_pcballoc(so, &V_udbinfo);
1440         if (error) {
1441                 INP_INFO_WUNLOCK(&V_udbinfo);
1442                 return (error);
1443         }
1444
1445         inp = sotoinpcb(so);
1446         inp->inp_vflag |= INP_IPV4;
1447         inp->inp_ip_ttl = V_ip_defttl;
1448
1449         error = udp_newudpcb(inp);
1450         if (error) {
1451                 in_pcbdetach(inp);
1452                 in_pcbfree(inp);
1453                 INP_INFO_WUNLOCK(&V_udbinfo);
1454                 return (error);
1455         }
1456
1457         INP_WUNLOCK(inp);
1458         INP_INFO_WUNLOCK(&V_udbinfo);
1459         return (0);
1460 }
1461 #endif /* INET */
1462
1463 int
1464 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1465 {
1466         struct inpcb *inp;
1467         struct udpcb *up;
1468
1469         KASSERT(so->so_type == SOCK_DGRAM,
1470             ("udp_set_kernel_tunneling: !dgram"));
1471         inp = sotoinpcb(so);
1472         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1473         INP_WLOCK(inp);
1474         up = intoudpcb(inp);
1475         if (up->u_tun_func != NULL) {
1476                 INP_WUNLOCK(inp);
1477                 return (EBUSY);
1478         }
1479         up->u_tun_func = f;
1480         INP_WUNLOCK(inp);
1481         return (0);
1482 }
1483
1484 #ifdef INET
1485 static int
1486 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1487 {
1488         struct inpcb *inp;
1489         int error;
1490
1491         inp = sotoinpcb(so);
1492         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1493         INP_WLOCK(inp);
1494         INP_HASH_WLOCK(&V_udbinfo);
1495         error = in_pcbbind(inp, nam, td->td_ucred);
1496         INP_HASH_WUNLOCK(&V_udbinfo);
1497         INP_WUNLOCK(inp);
1498         return (error);
1499 }
1500
1501 static void
1502 udp_close(struct socket *so)
1503 {
1504         struct inpcb *inp;
1505
1506         inp = sotoinpcb(so);
1507         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1508         INP_WLOCK(inp);
1509         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1510                 INP_HASH_WLOCK(&V_udbinfo);
1511                 in_pcbdisconnect(inp);
1512                 inp->inp_laddr.s_addr = INADDR_ANY;
1513                 INP_HASH_WUNLOCK(&V_udbinfo);
1514                 soisdisconnected(so);
1515         }
1516         INP_WUNLOCK(inp);
1517 }
1518
1519 static int
1520 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1521 {
1522         struct inpcb *inp;
1523         int error;
1524         struct sockaddr_in *sin;
1525
1526         inp = sotoinpcb(so);
1527         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1528         INP_WLOCK(inp);
1529         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1530                 INP_WUNLOCK(inp);
1531                 return (EISCONN);
1532         }
1533         sin = (struct sockaddr_in *)nam;
1534         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1535         if (error != 0) {
1536                 INP_WUNLOCK(inp);
1537                 return (error);
1538         }
1539         INP_HASH_WLOCK(&V_udbinfo);
1540         error = in_pcbconnect(inp, nam, td->td_ucred);
1541         INP_HASH_WUNLOCK(&V_udbinfo);
1542         if (error == 0)
1543                 soisconnected(so);
1544         INP_WUNLOCK(inp);
1545         return (error);
1546 }
1547
1548 static void
1549 udp_detach(struct socket *so)
1550 {
1551         struct inpcb *inp;
1552         struct udpcb *up;
1553
1554         inp = sotoinpcb(so);
1555         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1556         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1557             ("udp_detach: not disconnected"));
1558         INP_INFO_WLOCK(&V_udbinfo);
1559         INP_WLOCK(inp);
1560         up = intoudpcb(inp);
1561         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1562         inp->inp_ppcb = NULL;
1563         in_pcbdetach(inp);
1564         in_pcbfree(inp);
1565         INP_INFO_WUNLOCK(&V_udbinfo);
1566         udp_discardcb(up);
1567 }
1568
1569 static int
1570 udp_disconnect(struct socket *so)
1571 {
1572         struct inpcb *inp;
1573
1574         inp = sotoinpcb(so);
1575         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1576         INP_WLOCK(inp);
1577         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1578                 INP_WUNLOCK(inp);
1579                 return (ENOTCONN);
1580         }
1581         INP_HASH_WLOCK(&V_udbinfo);
1582         in_pcbdisconnect(inp);
1583         inp->inp_laddr.s_addr = INADDR_ANY;
1584         INP_HASH_WUNLOCK(&V_udbinfo);
1585         SOCK_LOCK(so);
1586         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1587         SOCK_UNLOCK(so);
1588         INP_WUNLOCK(inp);
1589         return (0);
1590 }
1591
1592 static int
1593 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1594     struct mbuf *control, struct thread *td)
1595 {
1596         struct inpcb *inp;
1597
1598         inp = sotoinpcb(so);
1599         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1600         return (udp_output(inp, m, addr, control, td));
1601 }
1602 #endif /* INET */
1603
1604 int
1605 udp_shutdown(struct socket *so)
1606 {
1607         struct inpcb *inp;
1608
1609         inp = sotoinpcb(so);
1610         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1611         INP_WLOCK(inp);
1612         socantsendmore(so);
1613         INP_WUNLOCK(inp);
1614         return (0);
1615 }
1616
1617 #ifdef INET
1618 struct pr_usrreqs udp_usrreqs = {
1619         .pru_abort =            udp_abort,
1620         .pru_attach =           udp_attach,
1621         .pru_bind =             udp_bind,
1622         .pru_connect =          udp_connect,
1623         .pru_control =          in_control,
1624         .pru_detach =           udp_detach,
1625         .pru_disconnect =       udp_disconnect,
1626         .pru_peeraddr =         in_getpeeraddr,
1627         .pru_send =             udp_send,
1628         .pru_soreceive =        soreceive_dgram,
1629         .pru_sosend =           sosend_dgram,
1630         .pru_shutdown =         udp_shutdown,
1631         .pru_sockaddr =         in_getsockaddr,
1632         .pru_sosetlabel =       in_pcbsosetlabel,
1633         .pru_close =            udp_close,
1634 };
1635 #endif /* INET */