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  * Copyright (c) 2014 Kevin Lo
   7  * All rights reserved.
   8  *
   9  * Portions of this software were developed by Robert N. M. Watson under
  10  * contract to Juniper Networks, Inc.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  37  */
  38
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD$");
  41
  42 #include "opt_ipfw.h"
  43 #include "opt_inet.h"
  44 #include "opt_inet6.h"
  45 #include "opt_ipsec.h"
  46 #include "opt_kdtrace.h"
  47
  48 #include <sys/param.h>
  49 #include <sys/domain.h>
  50 #include <sys/eventhandler.h>
  51 #include <sys/jail.h>
  52 #include <sys/kernel.h>
  53 #include <sys/lock.h>
  54 #include <sys/malloc.h>
  55 #include <sys/mbuf.h>
  56 #include <sys/priv.h>
  57 #include <sys/proc.h>
  58 #include <sys/protosw.h>
  59 #include <sys/sdt.h>
  60 #include <sys/signalvar.h>
  61 #include <sys/socket.h>
  62 #include <sys/socketvar.h>
  63 #include <sys/sx.h>
  64 #include <sys/sysctl.h>
  65 #include <sys/syslog.h>
  66 #include <sys/systm.h>
  67
  68 #include <vm/uma.h>
  69
  70 #include <net/if.h>
  71 #include <net/route.h>
  72
  73 #include <netinet/in.h>
  74 #include <netinet/in_kdtrace.h>
  75 #include <netinet/in_pcb.h>
  76 #include <netinet/in_systm.h>
  77 #include <netinet/in_var.h>
  78 #include <netinet/ip.h>
  79 #ifdef INET6
  80 #include <netinet/ip6.h>
  81 #endif
  82 #include <netinet/ip_icmp.h>
  83 #include <netinet/icmp_var.h>
  84 #include <netinet/ip_var.h>
  85 #include <netinet/ip_options.h>
  86 #ifdef INET6
  87 #include <netinet6/ip6_var.h>
  88 #endif
  89 #include <netinet/udp.h>
  90 #include <netinet/udp_var.h>
  91 #include <netinet/udplite.h>
  92
  93 #ifdef IPSEC
  94 #include <netipsec/ipsec.h>
  95 #include <netipsec/esp.h>
  96 #endif
  97
  98 #include <machine/in_cksum.h>
  99
 100 #include <security/mac/mac_framework.h>
 101
 102 /*
 103  * UDP and UDP-Lite protocols implementation.
 104  * Per RFC 768, August, 1980.
 105  * Per RFC 3828, July, 2004.
 106  */
 107
 108 /*
 109  * BSD 4.2 defaulted the udp checksum to be off.  Turning off udp checksums
 110  * removes the only data integrity mechanism for packets and malformed
 111  * packets that would otherwise be discarded due to bad checksums, and may
 112  * cause problems (especially for NFS data blocks).
 113  */
 114 VNET_DEFINE(int, udp_cksum) = 1;
 115 SYSCTL_VNET_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
 116     &VNET_NAME(udp_cksum), 0, "compute udp checksum");
 117
 118 int     udp_log_in_vain = 0;
 119 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 120     &udp_log_in_vain, 0, "Log all incoming UDP packets");
 121
 122 VNET_DEFINE(int, udp_blackhole) = 0;
 123 SYSCTL_VNET_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 124     &VNET_NAME(udp_blackhole), 0,
 125     "Do not send port unreachables for refused connects");
 126
 127 u_long  udp_sendspace = 9216;           /* really max datagram size */
 128                                         /* 40 1K datagrams */
 129 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 130     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 131
 132 u_long  udp_recvspace = 40 * (1024 +
 133 #ifdef INET6
 134                                       sizeof(struct sockaddr_in6)
 135 #else
 136                                       sizeof(struct sockaddr_in)
 137 #endif
 138                                       );
 139
 140 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 141     &udp_recvspace, 0, "Maximum space for incoming UDP datagrams");
 142
 143 VNET_DEFINE(struct inpcbhead, udb);             /* from udp_var.h */
 144 VNET_DEFINE(struct inpcbinfo, udbinfo);
 145 VNET_DEFINE(struct inpcbhead, ulitecb);
 146 VNET_DEFINE(struct inpcbinfo, ulitecbinfo);
 147 static VNET_DEFINE(uma_zone_t, udpcb_zone);
 148 #define V_udpcb_zone                    VNET(udpcb_zone)
 149
 150 #ifndef UDBHASHSIZE
 151 #define UDBHASHSIZE     128
 152 #endif
 153
 154 VNET_PCPUSTAT_DEFINE(struct udpstat, udpstat);          /* from udp_var.h */
 155 VNET_PCPUSTAT_SYSINIT(udpstat);
 156 SYSCTL_VNET_PCPUSTAT(_net_inet_udp, UDPCTL_STATS, stats, struct udpstat,
 157     udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 158
 159 #ifdef VIMAGE
 160 VNET_PCPUSTAT_SYSUNINIT(udpstat);
 161 #endif /* VIMAGE */
 162 #ifdef INET
 163 static void     udp_detach(struct socket *so);
 164 static int      udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 165                     struct mbuf *, struct thread *);
 166 #endif
 167
 168 #ifdef IPSEC
 169 #ifdef IPSEC_NAT_T
 170 #define UF_ESPINUDP_ALL (UF_ESPINUDP_NON_IKE|UF_ESPINUDP)
 171 #ifdef INET
 172 static struct mbuf *udp4_espdecap(struct inpcb *, struct mbuf *, int);
 173 #endif
 174 #endif /* IPSEC_NAT_T */
 175 #endif /* IPSEC */
 176
 177 static void
 178 udp_zone_change(void *tag)
 179 {
 180
 181         uma_zone_set_max(V_udbinfo.ipi_zone, maxsockets);
 182         uma_zone_set_max(V_udpcb_zone, maxsockets);
 183 }
 184
 185 static int
 186 udp_inpcb_init(void *mem, int size, int flags)
 187 {
 188         struct inpcb *inp;
 189
 190         inp = mem;
 191         INP_LOCK_INIT(inp, "inp", "udpinp");
 192         return (0);
 193 }
 194
 195 static int
 196 udplite_inpcb_init(void *mem, int size, int flags)
 197 {
 198         struct inpcb *inp;
 199
 200         inp = mem;
 201         INP_LOCK_INIT(inp, "inp", "udpliteinp");
 202         return (0);
 203 }
 204
 205 void
 206 udp_init(void)
 207 {
 208
 209         in_pcbinfo_init(&V_udbinfo, "udp", &V_udb, UDBHASHSIZE, UDBHASHSIZE,
 210             "udp_inpcb", udp_inpcb_init, NULL, UMA_ZONE_NOFREE,
 211             IPI_HASHFIELDS_2TUPLE);
 212         V_udpcb_zone = uma_zcreate("udpcb", sizeof(struct udpcb),
 213             NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 214         uma_zone_set_max(V_udpcb_zone, maxsockets);
 215         uma_zone_set_warning(V_udpcb_zone, "kern.ipc.maxsockets limit reached");
 216         EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL,
 217             EVENTHANDLER_PRI_ANY);
 218 }
 219
 220 void
 221 udplite_init(void)
 222 {
 223
 224         in_pcbinfo_init(&V_ulitecbinfo, "udplite", &V_ulitecb, UDBHASHSIZE,
 225             UDBHASHSIZE, "udplite_inpcb", udplite_inpcb_init, NULL,
 226             UMA_ZONE_NOFREE, IPI_HASHFIELDS_2TUPLE);
 227 }
 228
 229 /*
 230  * Kernel module interface for updating udpstat.  The argument is an index
 231  * into udpstat treated as an array of u_long.  While this encodes the
 232  * general layout of udpstat into the caller, it doesn't encode its location,
 233  * so that future changes to add, for example, per-CPU stats support won't
 234  * cause binary compatibility problems for kernel modules.
 235  */
 236 void
 237 kmod_udpstat_inc(int statnum)
 238 {
 239
 240         counter_u64_add(VNET(udpstat)[statnum], 1);
 241 }
 242
 243 int
 244 udp_newudpcb(struct inpcb *inp)
 245 {
 246         struct udpcb *up;
 247
 248         up = uma_zalloc(V_udpcb_zone, M_NOWAIT | M_ZERO);
 249         if (up == NULL)
 250                 return (ENOBUFS);
 251         inp->inp_ppcb = up;
 252         return (0);
 253 }
 254
 255 void
 256 udp_discardcb(struct udpcb *up)
 257 {
 258
 259         uma_zfree(V_udpcb_zone, up);
 260 }
 261
 262 #ifdef VIMAGE
 263 void
 264 udp_destroy(void)
 265 {
 266
 267         in_pcbinfo_destroy(&V_udbinfo);
 268         uma_zdestroy(V_udpcb_zone);
 269 }
 270
 271 void
 272 udplite_destroy(void)
 273 {
 274
 275         in_pcbinfo_destroy(&V_ulitecbinfo);
 276 }
 277 #endif
 278
 279 #ifdef INET
 280 /*
 281  * Subroutine of udp_input(), which appends the provided mbuf chain to the
 282  * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 283  * contains the source address.  If the socket ends up being an IPv6 socket,
 284  * udp_append() will convert to a sockaddr_in6 before passing the address
 285  * into the socket code.
 286  */
 287 static void
 288 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 289     struct sockaddr_in *udp_in)
 290 {
 291         struct sockaddr *append_sa;
 292         struct socket *so;
 293         struct mbuf *opts = 0;
 294 #ifdef INET6
 295         struct sockaddr_in6 udp_in6;
 296 #endif
 297         struct udpcb *up;
 298
 299         INP_LOCK_ASSERT(inp);
 300
 301         /*
 302          * Engage the tunneling protocol.
 303          */
 304         up = intoudpcb(inp);
 305         if (up->u_tun_func != NULL) {
 306                 (*up->u_tun_func)(n, off, inp);
 307                 return;
 308         }
 309
 310         if (n == NULL)
 311                 return;
 312
 313         off += sizeof(struct udphdr);
 314
 315 #ifdef IPSEC
 316         /* Check AH/ESP integrity. */
 317         if (ipsec4_in_reject(n, inp)) {
 318                 m_freem(n);
 319                 IPSECSTAT_INC(ips_in_polvio);
 320                 return;
 321         }
 322 #ifdef IPSEC_NAT_T
 323         up = intoudpcb(inp);
 324         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
 325         if (up->u_flags & UF_ESPINUDP_ALL) {    /* IPSec UDP encaps. */
 326                 n = udp4_espdecap(inp, n, off);
 327                 if (n == NULL)                          /* Consumed. */
 328                         return;
 329         }
 330 #endif /* IPSEC_NAT_T */
 331 #endif /* IPSEC */
 332 #ifdef MAC
 333         if (mac_inpcb_check_deliver(inp, n) != 0) {
 334                 m_freem(n);
 335                 return;
 336         }
 337 #endif /* MAC */
 338         if (inp->inp_flags & INP_CONTROLOPTS ||
 339             inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
 340 #ifdef INET6
 341                 if (inp->inp_vflag & INP_IPV6)
 342                         (void)ip6_savecontrol_v4(inp, n, &opts, NULL);
 343                 else
 344 #endif /* INET6 */
 345                         ip_savecontrol(inp, &opts, ip, n);
 346         }
 347 #ifdef INET6
 348         if (inp->inp_vflag & INP_IPV6) {
 349                 bzero(&udp_in6, sizeof(udp_in6));
 350                 udp_in6.sin6_len = sizeof(udp_in6);
 351                 udp_in6.sin6_family = AF_INET6;
 352                 in6_sin_2_v4mapsin6(udp_in, &udp_in6);
 353                 append_sa = (struct sockaddr *)&udp_in6;
 354         } else
 355 #endif /* INET6 */
 356                 append_sa = (struct sockaddr *)udp_in;
 357         m_adj(n, off);
 358
 359         so = inp->inp_socket;
 360         SOCKBUF_LOCK(&so->so_rcv);
 361         if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
 362                 SOCKBUF_UNLOCK(&so->so_rcv);
 363                 m_freem(n);
 364                 if (opts)
 365                         m_freem(opts);
 366                 UDPSTAT_INC(udps_fullsock);
 367         } else
 368                 sorwakeup_locked(so);
 369 }
 370
 371 void
 372 udp_input(struct mbuf *m, int off)
 373 {
 374         int iphlen = off;
 375         struct ip *ip;
 376         struct udphdr *uh;
 377         struct ifnet *ifp;
 378         struct inpcb *inp;
 379         uint16_t len, ip_len;
 380         struct inpcbinfo *pcbinfo;
 381         struct ip save_ip;
 382         struct sockaddr_in udp_in;
 383         struct m_tag *fwd_tag;
 384         int cscov_partial;
 385         uint8_t pr;
 386
 387         ifp = m->m_pkthdr.rcvif;
 388         UDPSTAT_INC(udps_ipackets);
 389
 390         /*
 391          * Strip IP options, if any; should skip this, make available to
 392          * user, and use on returned packets, but we don't yet have a way to
 393          * check the checksum with options still present.
 394          */
 395         if (iphlen > sizeof (struct ip)) {
 396                 ip_stripoptions(m);
 397                 iphlen = sizeof(struct ip);
 398         }
 399
 400         /*
 401          * Get IP and UDP header together in first mbuf.
 402          */
 403         ip = mtod(m, struct ip *);
 404         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 405                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
 406                         UDPSTAT_INC(udps_hdrops);
 407                         return;
 408                 }
 409                 ip = mtod(m, struct ip *);
 410         }
 411         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 412         pr = ip->ip_p;
 413         cscov_partial = (pr == IPPROTO_UDPLITE) ? 1 : 0;
 414
 415         /*
 416          * Destination port of 0 is illegal, based on RFC768.
 417          */
 418         if (uh->uh_dport == 0)
 419                 goto badunlocked;
 420
 421         /*
 422          * Construct sockaddr format source address.  Stuff source address
 423          * and datagram in user buffer.
 424          */
 425         bzero(&udp_in, sizeof(udp_in));
 426         udp_in.sin_len = sizeof(udp_in);
 427         udp_in.sin_family = AF_INET;
 428         udp_in.sin_port = uh->uh_sport;
 429         udp_in.sin_addr = ip->ip_src;
 430
 431         /*
 432          * Make mbuf data length reflect UDP length.  If not enough data to
 433          * reflect UDP length, drop.
 434          */
 435         len = ntohs((u_short)uh->uh_ulen);
 436         ip_len = ntohs(ip->ip_len) - iphlen;
 437         if (pr == IPPROTO_UDPLITE && len == 0) {
 438                 /* Zero means checksum over the complete packet. */
 439                 len = ip_len;
 440                 cscov_partial = 0;
 441         }
 442         if (ip_len != len) {
 443                 if (len > ip_len || len < sizeof(struct udphdr)) {
 444                         UDPSTAT_INC(udps_badlen);
 445                         goto badunlocked;
 446                 }
 447                 if (pr == IPPROTO_UDP)
 448                         m_adj(m, len - ip_len);
 449         }
 450
 451         /*
 452          * Save a copy of the IP header in case we want restore it for
 453          * sending an ICMP error message in response.
 454          */
 455         if (!V_udp_blackhole)
 456                 save_ip = *ip;
 457         else
 458                 memset(&save_ip, 0, sizeof(save_ip));
 459
 460         /*
 461          * Checksum extended UDP header and data.
 462          */
 463         if (uh->uh_sum) {
 464                 u_short uh_sum;
 465
 466                 if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
 467                     !cscov_partial) {
 468                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 469                                 uh_sum = m->m_pkthdr.csum_data;
 470                         else
 471                                 uh_sum = in_pseudo(ip->ip_src.s_addr,
 472                                     ip->ip_dst.s_addr, htonl((u_short)len +
 473                                     m->m_pkthdr.csum_data + pr));
 474                         uh_sum ^= 0xffff;
 475                 } else {
 476                         char b[9];
 477
 478                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 479                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 480                         ((struct ipovly *)ip)->ih_len = (pr == IPPROTO_UDP) ?
 481                             uh->uh_ulen : htons(ip_len);
 482                         uh_sum = in_cksum(m, len + sizeof (struct ip));
 483                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 484                 }
 485                 if (uh_sum) {
 486                         UDPSTAT_INC(udps_badsum);
 487                         m_freem(m);
 488                         return;
 489                 }
 490         } else
 491                 UDPSTAT_INC(udps_nosum);
 492
 493         pcbinfo = get_inpcbinfo(pr);
 494         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 495             in_broadcast(ip->ip_dst, ifp)) {
 496                 struct inpcb *last;
 497                 struct inpcbhead *pcblist;
 498                 struct ip_moptions *imo;
 499
 500                 INP_INFO_RLOCK(pcbinfo);
 501                 pcblist = get_pcblist(pr);
 502                 last = NULL;
 503                 LIST_FOREACH(inp, pcblist, inp_list) {
 504                         if (inp->inp_lport != uh->uh_dport)
 505                                 continue;
 506 #ifdef INET6
 507                         if ((inp->inp_vflag & INP_IPV4) == 0)
 508                                 continue;
 509 #endif
 510                         if (inp->inp_laddr.s_addr != INADDR_ANY &&
 511                             inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 512                                 continue;
 513                         if (inp->inp_faddr.s_addr != INADDR_ANY &&
 514                             inp->inp_faddr.s_addr != ip->ip_src.s_addr)
 515                                 continue;
 516                         if (inp->inp_fport != 0 &&
 517                             inp->inp_fport != uh->uh_sport)
 518                                 continue;
 519
 520                         INP_RLOCK(inp);
 521
 522                         /*
 523                          * XXXRW: Because we weren't holding either the inpcb
 524                          * or the hash lock when we checked for a match
 525                          * before, we should probably recheck now that the
 526                          * inpcb lock is held.
 527                          */
 528
 529                         /*
 530                          * Handle socket delivery policy for any-source
 531                          * and source-specific multicast. [RFC3678]
 532                          */
 533                         imo = inp->inp_moptions;
 534                         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 535                                 struct sockaddr_in       group;
 536                                 int                      blocked;
 537                                 if (imo == NULL) {
 538                                         INP_RUNLOCK(inp);
 539                                         continue;
 540                                 }
 541                                 bzero(&group, sizeof(struct sockaddr_in));
 542                                 group.sin_len = sizeof(struct sockaddr_in);
 543                                 group.sin_family = AF_INET;
 544                                 group.sin_addr = ip->ip_dst;
 545
 546                                 blocked = imo_multi_filter(imo, ifp,
 547                                         (struct sockaddr *)&group,
 548                                         (struct sockaddr *)&udp_in);
 549                                 if (blocked != MCAST_PASS) {
 550                                         if (blocked == MCAST_NOTGMEMBER)
 551                                                 IPSTAT_INC(ips_notmember);
 552                                         if (blocked == MCAST_NOTSMEMBER ||
 553                                             blocked == MCAST_MUTED)
 554                                                 UDPSTAT_INC(udps_filtermcast);
 555                                         INP_RUNLOCK(inp);
 556                                         continue;
 557                                 }
 558                         }
 559                         if (last != NULL) {
 560                                 struct mbuf *n;
 561
 562                                 n = m_copy(m, 0, M_COPYALL);
 563                                 udp_append(last, ip, n, iphlen, &udp_in);
 564                                 INP_RUNLOCK(last);
 565                         }
 566                         last = inp;
 567                         /*
 568                          * Don't look for additional matches if this one does
 569                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 570                          * socket options set.  This heuristic avoids
 571                          * searching through all pcbs in the common case of a
 572                          * non-shared port.  It assumes that an application
 573                          * will never clear these options after setting them.
 574                          */
 575                         if ((last->inp_socket->so_options &
 576                             (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 577                                 break;
 578                 }
 579
 580                 if (last == NULL) {
 581                         /*
 582                          * No matching pcb found; discard datagram.  (No need
 583                          * to send an ICMP Port Unreachable for a broadcast
 584                          * or multicast datgram.)
 585                          */
 586                         UDPSTAT_INC(udps_noportbcast);
 587                         if (inp)
 588                                 INP_RUNLOCK(inp);
 589                         INP_INFO_RUNLOCK(pcbinfo);
 590                         goto badunlocked;
 591                 }
 592                 udp_append(last, ip, m, iphlen, &udp_in);
 593                 INP_RUNLOCK(last);
 594                 INP_INFO_RUNLOCK(pcbinfo);
 595                 return;
 596         }
 597
 598         /*
 599          * Locate pcb for datagram.
 600          */
 601
 602         /*
 603          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 604          */
 605         if ((m->m_flags & M_IP_NEXTHOP) &&
 606             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 607                 struct sockaddr_in *next_hop;
 608
 609                 next_hop = (struct sockaddr_in *)(fwd_tag + 1);
 610
 611                 /*
 612                  * Transparently forwarded. Pretend to be the destination.
 613                  * Already got one like this?
 614                  */
 615                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
 616                     ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, m);
 617                 if (!inp) {
 618                         /*
 619                          * It's new.  Try to find the ambushing socket.
 620                          * Because we've rewritten the destination address,
 621                          * any hardware-generated hash is ignored.
 622                          */
 623                         inp = in_pcblookup(pcbinfo, ip->ip_src,
 624                             uh->uh_sport, next_hop->sin_addr,
 625                             next_hop->sin_port ? htons(next_hop->sin_port) :
 626                             uh->uh_dport, INPLOOKUP_WILDCARD |
 627                             INPLOOKUP_RLOCKPCB, ifp);
 628                 }
 629                 /* Remove the tag from the packet. We don't need it anymore. */
 630                 m_tag_delete(m, fwd_tag);
 631                 m->m_flags &= ~M_IP_NEXTHOP;
 632         } else
 633                 inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
 634                     ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
 635                     INPLOOKUP_RLOCKPCB, ifp, m);
 636         if (inp == NULL) {
 637                 if (udp_log_in_vain) {
 638                         char buf[4*sizeof "123"];
 639
 640                         strcpy(buf, inet_ntoa(ip->ip_dst));
 641                         log(LOG_INFO,
 642                             "Connection attempt to UDP %s:%d from %s:%d\n",
 643                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 644                             ntohs(uh->uh_sport));
 645                 }
 646                 UDPSTAT_INC(udps_noport);
 647                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 648                         UDPSTAT_INC(udps_noportbcast);
 649                         goto badunlocked;
 650                 }
 651                 if (V_udp_blackhole)
 652                         goto badunlocked;
 653                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 654                         goto badunlocked;
 655                 *ip = save_ip;
 656                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 657                 return;
 658         }
 659
 660         /*
 661          * Check the minimum TTL for socket.
 662          */
 663         INP_RLOCK_ASSERT(inp);
 664         if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
 665                 INP_RUNLOCK(inp);
 666                 m_freem(m);
 667                 return;
 668         }
 669         if (cscov_partial) {
 670                 struct udpcb *up;
 671
 672                 up = intoudpcb(inp);
 673                 if (up->u_rxcslen > len) {
 674                         INP_RUNLOCK(inp);
 675                         m_freem(m);
 676                         return;
 677                 }
 678         }
 679
 680         UDP_PROBE(receive, NULL, inp, ip, inp, uh);
 681         udp_append(inp, ip, m, iphlen, &udp_in);
 682         INP_RUNLOCK(inp);
 683         return;
 684
 685 badunlocked:
 686         m_freem(m);
 687 }
 688 #endif /* INET */
 689
 690 /*
 691  * Notify a udp user of an asynchronous error; just wake up so that they can
 692  * collect error status.
 693  */
 694 struct inpcb *
 695 udp_notify(struct inpcb *inp, int errno)
 696 {
 697
 698         /*
 699          * While udp_ctlinput() always calls udp_notify() with a read lock
 700          * when invoking it directly, in_pcbnotifyall() currently uses write
 701          * locks due to sharing code with TCP.  For now, accept either a read
 702          * or a write lock, but a read lock is sufficient.
 703          */
 704         INP_LOCK_ASSERT(inp);
 705
 706         inp->inp_socket->so_error = errno;
 707         sorwakeup(inp->inp_socket);
 708         sowwakeup(inp->inp_socket);
 709         return (inp);
 710 }
 711
 712 #ifdef INET
 713 static void
 714 udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
 715     struct inpcbinfo *pcbinfo)
 716 {
 717         struct ip *ip = vip;
 718         struct udphdr *uh;
 719         struct in_addr faddr;
 720         struct inpcb *inp;
 721
 722         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 723         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 724                 return;
 725
 726         /*
 727          * Redirects don't need to be handled up here.
 728          */
 729         if (PRC_IS_REDIRECT(cmd))
 730                 return;
 731
 732         /*
 733          * Hostdead is ugly because it goes linearly through all PCBs.
 734          *
 735          * XXX: We never get this from ICMP, otherwise it makes an excellent
 736          * DoS attack on machines with many connections.
 737          */
 738         if (cmd == PRC_HOSTDEAD)
 739                 ip = NULL;
 740         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 741                 return;
 742         if (ip != NULL) {
 743                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 744                 inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
 745                     ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
 746                 if (inp != NULL) {
 747                         INP_RLOCK_ASSERT(inp);
 748                         if (inp->inp_socket != NULL) {
 749                                 udp_notify(inp, inetctlerrmap[cmd]);
 750                         }
 751                         INP_RUNLOCK(inp);
 752                 }
 753         } else
 754                 in_pcbnotifyall(pcbinfo, faddr, inetctlerrmap[cmd],
 755                     udp_notify);
 756 }
 757 void
 758 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 759 {
 760
 761         return (udp_common_ctlinput(cmd, sa, vip, &V_udbinfo));
 762 }
 763
 764 void
 765 udplite_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 766 {
 767
 768         return (udp_common_ctlinput(cmd, sa, vip, &V_ulitecbinfo));
 769 }
 770 #endif /* INET */
 771
 772 static int
 773 udp_pcblist(SYSCTL_HANDLER_ARGS)
 774 {
 775         int error, i, n;
 776         struct inpcb *inp, **inp_list;
 777         inp_gen_t gencnt;
 778         struct xinpgen xig;
 779
 780         /*
 781          * The process of preparing the PCB list is too time-consuming and
 782          * resource-intensive to repeat twice on every request.
 783          */
 784         if (req->oldptr == 0) {
 785                 n = V_udbinfo.ipi_count;
 786                 n += imax(n / 8, 10);
 787                 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 788                 return (0);
 789         }
 790
 791         if (req->newptr != 0)
 792                 return (EPERM);
 793
 794         /*
 795          * OK, now we're committed to doing something.
 796          */
 797         INP_INFO_RLOCK(&V_udbinfo);
 798         gencnt = V_udbinfo.ipi_gencnt;
 799         n = V_udbinfo.ipi_count;
 800         INP_INFO_RUNLOCK(&V_udbinfo);
 801
 802         error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 803                 + n * sizeof(struct xinpcb));
 804         if (error != 0)
 805                 return (error);
 806
 807         xig.xig_len = sizeof xig;
 808         xig.xig_count = n;
 809         xig.xig_gen = gencnt;
 810         xig.xig_sogen = so_gencnt;
 811         error = SYSCTL_OUT(req, &xig, sizeof xig);
 812         if (error)
 813                 return (error);
 814
 815         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 816         if (inp_list == 0)
 817                 return (ENOMEM);
 818
 819         INP_INFO_RLOCK(&V_udbinfo);
 820         for (inp = LIST_FIRST(V_udbinfo.ipi_listhead), i = 0; inp && i < n;
 821              inp = LIST_NEXT(inp, inp_list)) {
 822                 INP_WLOCK(inp);
 823                 if (inp->inp_gencnt <= gencnt &&
 824                     cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
 825                         in_pcbref(inp);
 826                         inp_list[i++] = inp;
 827                 }
 828                 INP_WUNLOCK(inp);
 829         }
 830         INP_INFO_RUNLOCK(&V_udbinfo);
 831         n = i;
 832
 833         error = 0;
 834         for (i = 0; i < n; i++) {
 835                 inp = inp_list[i];
 836                 INP_RLOCK(inp);
 837                 if (inp->inp_gencnt <= gencnt) {
 838                         struct xinpcb xi;
 839
 840                         bzero(&xi, sizeof(xi));
 841                         xi.xi_len = sizeof xi;
 842                         /* XXX should avoid extra copy */
 843                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 844                         if (inp->inp_socket)
 845                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 846                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 847                         INP_RUNLOCK(inp);
 848                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 849                 } else
 850                         INP_RUNLOCK(inp);
 851         }
 852         INP_INFO_WLOCK(&V_udbinfo);
 853         for (i = 0; i < n; i++) {
 854                 inp = inp_list[i];
 855                 INP_RLOCK(inp);
 856                 if (!in_pcbrele_rlocked(inp))
 857                         INP_RUNLOCK(inp);
 858         }
 859         INP_INFO_WUNLOCK(&V_udbinfo);
 860
 861         if (!error) {
 862                 /*
 863                  * Give the user an updated idea of our state.  If the
 864                  * generation differs from what we told her before, she knows
 865                  * that something happened while we were processing this
 866                  * request, and it might be necessary to retry.
 867                  */
 868                 INP_INFO_RLOCK(&V_udbinfo);
 869                 xig.xig_gen = V_udbinfo.ipi_gencnt;
 870                 xig.xig_sogen = so_gencnt;
 871                 xig.xig_count = V_udbinfo.ipi_count;
 872                 INP_INFO_RUNLOCK(&V_udbinfo);
 873                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 874         }
 875         free(inp_list, M_TEMP);
 876         return (error);
 877 }
 878
 879 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
 880     CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
 881     udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 882
 883 #ifdef INET
 884 static int
 885 udp_getcred(SYSCTL_HANDLER_ARGS)
 886 {
 887         struct xucred xuc;
 888         struct sockaddr_in addrs[2];
 889         struct inpcb *inp;
 890         int error;
 891
 892         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 893         if (error)
 894                 return (error);
 895         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 896         if (error)
 897                 return (error);
 898         inp = in_pcblookup(&V_udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 899             addrs[0].sin_addr, addrs[0].sin_port,
 900             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 901         if (inp != NULL) {
 902                 INP_RLOCK_ASSERT(inp);
 903                 if (inp->inp_socket == NULL)
 904                         error = ENOENT;
 905                 if (error == 0)
 906                         error = cr_canseeinpcb(req->td->td_ucred, inp);
 907                 if (error == 0)
 908                         cru2x(inp->inp_cred, &xuc);
 909                 INP_RUNLOCK(inp);
 910         } else
 911                 error = ENOENT;
 912         if (error == 0)
 913                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 914         return (error);
 915 }
 916
 917 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 918     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 919     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 920 #endif /* INET */
 921
 922 int
 923 udp_ctloutput(struct socket *so, struct sockopt *sopt)
 924 {
 925         struct inpcb *inp;
 926         struct udpcb *up;
 927         int isudplite, error, optval;
 928
 929         error = 0;
 930         isudplite = (so->so_proto->pr_protocol == IPPROTO_UDPLITE) ? 1 : 0;
 931         inp = sotoinpcb(so);
 932         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 933         INP_WLOCK(inp);
 934         if (sopt->sopt_level != so->so_proto->pr_protocol) {
 935 #ifdef INET6
 936                 if (INP_CHECK_SOCKAF(so, AF_INET6)) {
 937                         INP_WUNLOCK(inp);
 938                         error = ip6_ctloutput(so, sopt);
 939                 }
 940 #endif
 941 #if defined(INET) && defined(INET6)
 942                 else
 943 #endif
 944 #ifdef INET
 945                 {
 946                         INP_WUNLOCK(inp);
 947                         error = ip_ctloutput(so, sopt);
 948                 }
 949 #endif
 950                 return (error);
 951         }
 952
 953         switch (sopt->sopt_dir) {
 954         case SOPT_SET:
 955                 switch (sopt->sopt_name) {
 956                 case UDP_ENCAP:
 957                         INP_WUNLOCK(inp);
 958                         error = sooptcopyin(sopt, &optval, sizeof optval,
 959                                             sizeof optval);
 960                         if (error)
 961                                 break;
 962                         inp = sotoinpcb(so);
 963                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
 964                         INP_WLOCK(inp);
 965 #ifdef IPSEC_NAT_T
 966                         up = intoudpcb(inp);
 967                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
 968 #endif
 969                         switch (optval) {
 970                         case 0:
 971                                 /* Clear all UDP encap. */
 972 #ifdef IPSEC_NAT_T
 973                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 974 #endif
 975                                 break;
 976 #ifdef IPSEC_NAT_T
 977                         case UDP_ENCAP_ESPINUDP:
 978                         case UDP_ENCAP_ESPINUDP_NON_IKE:
 979                                 up->u_flags &= ~UF_ESPINUDP_ALL;
 980                                 if (optval == UDP_ENCAP_ESPINUDP)
 981                                         up->u_flags |= UF_ESPINUDP;
 982                                 else if (optval == UDP_ENCAP_ESPINUDP_NON_IKE)
 983                                         up->u_flags |= UF_ESPINUDP_NON_IKE;
 984                                 break;
 985 #endif
 986                         default:
 987                                 error = EINVAL;
 988                                 break;
 989                         }
 990                         INP_WUNLOCK(inp);
 991                         break;
 992                 case UDPLITE_SEND_CSCOV:
 993                 case UDPLITE_RECV_CSCOV:
 994                         if (!isudplite) {
 995                                 INP_WUNLOCK(inp);
 996                                 error = ENOPROTOOPT;
 997                                 break;
 998                         }
 999                         INP_WUNLOCK(inp);
1000                         error = sooptcopyin(sopt, &optval, sizeof(optval),
1001                             sizeof(optval));
1002                         if (error != 0)
1003                                 break;
1004                         inp = sotoinpcb(so);
1005                         KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1006                         INP_WLOCK(inp);
1007                         up = intoudpcb(inp);
1008                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1009                         if (optval != 0 && optval < 8) {
1010                                 INP_WUNLOCK(inp);
1011                                 error = EINVAL;
1012                                 break;
1013                         }
1014                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1015                                 up->u_txcslen = optval;
1016                         else
1017                                 up->u_rxcslen = optval;
1018                         INP_WUNLOCK(inp);
1019                         break;
1020                 default:
1021                         INP_WUNLOCK(inp);
1022                         error = ENOPROTOOPT;
1023                         break;
1024                 }
1025                 break;
1026         case SOPT_GET:
1027                 switch (sopt->sopt_name) {
1028 #ifdef IPSEC_NAT_T
1029                 case UDP_ENCAP:
1030                         up = intoudpcb(inp);
1031                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1032                         optval = up->u_flags & UF_ESPINUDP_ALL;
1033                         INP_WUNLOCK(inp);
1034                         error = sooptcopyout(sopt, &optval, sizeof optval);
1035                         break;
1036 #endif
1037                 case UDPLITE_SEND_CSCOV:
1038                 case UDPLITE_RECV_CSCOV:
1039                         if (!isudplite) {
1040                                 INP_WUNLOCK(inp);
1041                                 error = ENOPROTOOPT;
1042                                 break;
1043                         }
1044                         up = intoudpcb(inp);
1045                         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1046                         if (sopt->sopt_name == UDPLITE_SEND_CSCOV)
1047                                 optval = up->u_txcslen;
1048                         else
1049                                 optval = up->u_rxcslen;
1050                         INP_WUNLOCK(inp);
1051                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1052                         break;
1053                 default:
1054                         INP_WUNLOCK(inp);
1055                         error = ENOPROTOOPT;
1056                         break;
1057                 }
1058                 break;
1059         }
1060         return (error);
1061 }
1062
1063 #ifdef INET
1064 #define UH_WLOCKED      2
1065 #define UH_RLOCKED      1
1066 #define UH_UNLOCKED     0
1067 static int
1068 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
1069     struct mbuf *control, struct thread *td)
1070 {
1071         struct udpiphdr *ui;
1072         int len = m->m_pkthdr.len;
1073         struct in_addr faddr, laddr;
1074         struct cmsghdr *cm;
1075         struct inpcbinfo *pcbinfo;
1076         struct sockaddr_in *sin, src;
1077         int cscov_partial = 0;
1078         int error = 0;
1079         int ipflags;
1080         u_short fport, lport;
1081         int unlock_udbinfo;
1082         u_char tos;
1083         uint8_t pr;
1084         uint16_t cscov = 0;
1085
1086         /*
1087          * udp_output() may need to temporarily bind or connect the current
1088          * inpcb.  As such, we don't know up front whether we will need the
1089          * pcbinfo lock or not.  Do any work to decide what is needed up
1090          * front before acquiring any locks.
1091          */
1092         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
1093                 if (control)
1094                         m_freem(control);
1095                 m_freem(m);
1096                 return (EMSGSIZE);
1097         }
1098
1099         src.sin_family = 0;
1100         INP_RLOCK(inp);
1101         tos = inp->inp_ip_tos;
1102         if (control != NULL) {
1103                 /*
1104                  * XXX: Currently, we assume all the optional information is
1105                  * stored in a single mbuf.
1106                  */
1107                 if (control->m_next) {
1108                         INP_RUNLOCK(inp);
1109                         m_freem(control);
1110                         m_freem(m);
1111                         return (EINVAL);
1112                 }
1113                 for (; control->m_len > 0;
1114                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
1115                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
1116                         cm = mtod(control, struct cmsghdr *);
1117                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
1118                             || cm->cmsg_len > control->m_len) {
1119                                 error = EINVAL;
1120                                 break;
1121                         }
1122                         if (cm->cmsg_level != IPPROTO_IP)
1123                                 continue;
1124
1125                         switch (cm->cmsg_type) {
1126                         case IP_SENDSRCADDR:
1127                                 if (cm->cmsg_len !=
1128                                     CMSG_LEN(sizeof(struct in_addr))) {
1129                                         error = EINVAL;
1130                                         break;
1131                                 }
1132                                 bzero(&src, sizeof(src));
1133                                 src.sin_family = AF_INET;
1134                                 src.sin_len = sizeof(src);
1135                                 src.sin_port = inp->inp_lport;
1136                                 src.sin_addr =
1137                                     *(struct in_addr *)CMSG_DATA(cm);
1138                                 break;
1139
1140                         case IP_TOS:
1141                                 if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
1142                                         error = EINVAL;
1143                                         break;
1144                                 }
1145                                 tos = *(u_char *)CMSG_DATA(cm);
1146                                 break;
1147
1148                         default:
1149                                 error = ENOPROTOOPT;
1150                                 break;
1151                         }
1152                         if (error)
1153                                 break;
1154                 }
1155                 m_freem(control);
1156         }
1157         if (error) {
1158                 INP_RUNLOCK(inp);
1159                 m_freem(m);
1160                 return (error);
1161         }
1162
1163         /*
1164          * Depending on whether or not the application has bound or connected
1165          * the socket, we may have to do varying levels of work.  The optimal
1166          * case is for a connected UDP socket, as a global lock isn't
1167          * required at all.
1168          *
1169          * In order to decide which we need, we require stability of the
1170          * inpcb binding, which we ensure by acquiring a read lock on the
1171          * inpcb.  This doesn't strictly follow the lock order, so we play
1172          * the trylock and retry game; note that we may end up with more
1173          * conservative locks than required the second time around, so later
1174          * assertions have to accept that.  Further analysis of the number of
1175          * misses under contention is required.
1176          *
1177          * XXXRW: Check that hash locking update here is correct.
1178          */
1179         pr = inp->inp_socket->so_proto->pr_protocol;
1180         pcbinfo = get_inpcbinfo(pr);
1181         sin = (struct sockaddr_in *)addr;
1182         if (sin != NULL &&
1183             (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
1184                 INP_RUNLOCK(inp);
1185                 INP_WLOCK(inp);
1186                 INP_HASH_WLOCK(pcbinfo);
1187                 unlock_udbinfo = UH_WLOCKED;
1188         } else if ((sin != NULL && (
1189             (sin->sin_addr.s_addr == INADDR_ANY) ||
1190             (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
1191             (inp->inp_laddr.s_addr == INADDR_ANY) ||
1192             (inp->inp_lport == 0))) ||
1193             (src.sin_family == AF_INET)) {
1194                 INP_HASH_RLOCK(pcbinfo);
1195                 unlock_udbinfo = UH_RLOCKED;
1196         } else
1197                 unlock_udbinfo = UH_UNLOCKED;
1198
1199         /*
1200          * If the IP_SENDSRCADDR control message was specified, override the
1201          * source address for this datagram.  Its use is invalidated if the
1202          * address thus specified is incomplete or clobbers other inpcbs.
1203          */
1204         laddr = inp->inp_laddr;
1205         lport = inp->inp_lport;
1206         if (src.sin_family == AF_INET) {
1207                 INP_HASH_LOCK_ASSERT(pcbinfo);
1208                 if ((lport == 0) ||
1209                     (laddr.s_addr == INADDR_ANY &&
1210                      src.sin_addr.s_addr == INADDR_ANY)) {
1211                         error = EINVAL;
1212                         goto release;
1213                 }
1214                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
1215                     &laddr.s_addr, &lport, td->td_ucred);
1216                 if (error)
1217                         goto release;
1218         }
1219
1220         /*
1221          * If a UDP socket has been connected, then a local address/port will
1222          * have been selected and bound.
1223          *
1224          * If a UDP socket has not been connected to, then an explicit
1225          * destination address must be used, in which case a local
1226          * address/port may not have been selected and bound.
1227          */
1228         if (sin != NULL) {
1229                 INP_LOCK_ASSERT(inp);
1230                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1231                         error = EISCONN;
1232                         goto release;
1233                 }
1234
1235                 /*
1236                  * Jail may rewrite the destination address, so let it do
1237                  * that before we use it.
1238                  */
1239                 error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1240                 if (error)
1241                         goto release;
1242
1243                 /*
1244                  * If a local address or port hasn't yet been selected, or if
1245                  * the destination address needs to be rewritten due to using
1246                  * a special INADDR_ constant, invoke in_pcbconnect_setup()
1247                  * to do the heavy lifting.  Once a port is selected, we
1248                  * commit the binding back to the socket; we also commit the
1249                  * binding of the address if in jail.
1250                  *
1251                  * If we already have a valid binding and we're not
1252                  * requesting a destination address rewrite, use a fast path.
1253                  */
1254                 if (inp->inp_laddr.s_addr == INADDR_ANY ||
1255                     inp->inp_lport == 0 ||
1256                     sin->sin_addr.s_addr == INADDR_ANY ||
1257                     sin->sin_addr.s_addr == INADDR_BROADCAST) {
1258                         INP_HASH_LOCK_ASSERT(pcbinfo);
1259                         error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
1260                             &lport, &faddr.s_addr, &fport, NULL,
1261                             td->td_ucred);
1262                         if (error)
1263                                 goto release;
1264
1265                         /*
1266                          * XXXRW: Why not commit the port if the address is
1267                          * !INADDR_ANY?
1268                          */
1269                         /* Commit the local port if newly assigned. */
1270                         if (inp->inp_laddr.s_addr == INADDR_ANY &&
1271                             inp->inp_lport == 0) {
1272                                 INP_WLOCK_ASSERT(inp);
1273                                 INP_HASH_WLOCK_ASSERT(pcbinfo);
1274                                 /*
1275                                  * Remember addr if jailed, to prevent
1276                                  * rebinding.
1277                                  */
1278                                 if (prison_flag(td->td_ucred, PR_IP4))
1279                                         inp->inp_laddr = laddr;
1280                                 inp->inp_lport = lport;
1281                                 if (in_pcbinshash(inp) != 0) {
1282                                         inp->inp_lport = 0;
1283                                         error = EAGAIN;
1284                                         goto release;
1285                                 }
1286                                 inp->inp_flags |= INP_ANONPORT;
1287                         }
1288                 } else {
1289                         faddr = sin->sin_addr;
1290                         fport = sin->sin_port;
1291                 }
1292         } else {
1293                 INP_LOCK_ASSERT(inp);
1294                 faddr = inp->inp_faddr;
1295                 fport = inp->inp_fport;
1296                 if (faddr.s_addr == INADDR_ANY) {
1297                         error = ENOTCONN;
1298                         goto release;
1299                 }
1300         }
1301
1302         /*
1303          * Calculate data length and get a mbuf for UDP, IP, and possible
1304          * link-layer headers.  Immediate slide the data pointer back forward
1305          * since we won't use that space at this layer.
1306          */
1307         M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
1308         if (m == NULL) {
1309                 error = ENOBUFS;
1310                 goto release;
1311         }
1312         m->m_data += max_linkhdr;
1313         m->m_len -= max_linkhdr;
1314         m->m_pkthdr.len -= max_linkhdr;
1315
1316         /*
1317          * Fill in mbuf with extended UDP header and addresses and length put
1318          * into network format.
1319          */
1320         ui = mtod(m, struct udpiphdr *);
1321         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
1322         ui->ui_pr = pr;
1323         ui->ui_src = laddr;
1324         ui->ui_dst = faddr;
1325         ui->ui_sport = lport;
1326         ui->ui_dport = fport;
1327         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
1328         if (pr == IPPROTO_UDPLITE) {
1329                 struct udpcb *up;
1330                 uint16_t plen;
1331
1332                 up = intoudpcb(inp);
1333                 cscov = up->u_txcslen;
1334                 plen = (u_short)len + sizeof(struct udphdr);
1335                 if (cscov >= plen)
1336                         cscov = 0;
1337                 ui->ui_len = htons(plen);
1338                 ui->ui_ulen = htons(cscov);
1339                 /*
1340                  * For UDP-Lite, checksum coverage length of zero means
1341                  * the entire UDPLite packet is covered by the checksum.
1342                  */
1343                 cscov_partial = (cscov == 0) ? 0 : 1;
1344         } else
1345                 ui->ui_v = IPVERSION << 4;
1346
1347         /*
1348          * Set the Don't Fragment bit in the IP header.
1349          */
1350         if (inp->inp_flags & INP_DONTFRAG) {
1351                 struct ip *ip;
1352
1353                 ip = (struct ip *)&ui->ui_i;
1354                 ip->ip_off |= htons(IP_DF);
1355         }
1356
1357         ipflags = 0;
1358         if (inp->inp_socket->so_options & SO_DONTROUTE)
1359                 ipflags |= IP_ROUTETOIF;
1360         if (inp->inp_socket->so_options & SO_BROADCAST)
1361                 ipflags |= IP_ALLOWBROADCAST;
1362         if (inp->inp_flags & INP_ONESBCAST)
1363                 ipflags |= IP_SENDONES;
1364
1365 #ifdef MAC
1366         mac_inpcb_create_mbuf(inp, m);
1367 #endif
1368
1369         /*
1370          * Set up checksum and output datagram.
1371          */
1372         ui->ui_sum = 0;
1373         if (pr == IPPROTO_UDPLITE) {
1374                 if (inp->inp_flags & INP_ONESBCAST)
1375                         faddr.s_addr = INADDR_BROADCAST;
1376                 if (cscov_partial) {
1377                         if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
1378                                 ui->ui_sum = 0xffff;
1379                 } else {
1380                         if ((ui->ui_sum = in_cksum(m, sizeof(struct udpiphdr) + len)) == 0)
1381                                 ui->ui_sum = 0xffff;
1382                 }
1383         } else if (V_udp_cksum) {
1384                 if (inp->inp_flags & INP_ONESBCAST)
1385                         faddr.s_addr = INADDR_BROADCAST;
1386                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
1387                     htons((u_short)len + sizeof(struct udphdr) + pr));
1388                 m->m_pkthdr.csum_flags = CSUM_UDP;
1389                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
1390         }
1391         ((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
1392         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
1393         ((struct ip *)ui)->ip_tos = tos;                /* XXX */
1394         UDPSTAT_INC(udps_opackets);
1395
1396         if (unlock_udbinfo == UH_WLOCKED)
1397                 INP_HASH_WUNLOCK(pcbinfo);
1398         else if (unlock_udbinfo == UH_RLOCKED)
1399                 INP_HASH_RUNLOCK(pcbinfo);
1400         UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
1401         error = ip_output(m, inp->inp_options, NULL, ipflags,
1402             inp->inp_moptions, inp);
1403         if (unlock_udbinfo == UH_WLOCKED)
1404                 INP_WUNLOCK(inp);
1405         else
1406                 INP_RUNLOCK(inp);
1407         return (error);
1408
1409 release:
1410         if (unlock_udbinfo == UH_WLOCKED) {
1411                 INP_HASH_WUNLOCK(pcbinfo);
1412                 INP_WUNLOCK(inp);
1413         } else if (unlock_udbinfo == UH_RLOCKED) {
1414                 INP_HASH_RUNLOCK(pcbinfo);
1415                 INP_RUNLOCK(inp);
1416         } else
1417                 INP_RUNLOCK(inp);
1418         m_freem(m);
1419         return (error);
1420 }
1421
1422
1423 #if defined(IPSEC) && defined(IPSEC_NAT_T)
1424 /*
1425  * Potentially decap ESP in UDP frame.  Check for an ESP header
1426  * and optional marker; if present, strip the UDP header and
1427  * push the result through IPSec.
1428  *
1429  * Returns mbuf to be processed (potentially re-allocated) or
1430  * NULL if consumed and/or processed.
1431  */
1432 static struct mbuf *
1433 udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
1434 {
1435         size_t minlen, payload, skip, iphlen;
1436         caddr_t data;
1437         struct udpcb *up;
1438         struct m_tag *tag;
1439         struct udphdr *udphdr;
1440         struct ip *ip;
1441
1442         INP_RLOCK_ASSERT(inp);
1443
1444         /*
1445          * Pull up data so the longest case is contiguous:
1446          *    IP/UDP hdr + non ESP marker + ESP hdr.
1447          */
1448         minlen = off + sizeof(uint64_t) + sizeof(struct esp);
1449         if (minlen > m->m_pkthdr.len)
1450                 minlen = m->m_pkthdr.len;
1451         if ((m = m_pullup(m, minlen)) == NULL) {
1452                 IPSECSTAT_INC(ips_in_inval);
1453                 return (NULL);          /* Bypass caller processing. */
1454         }
1455         data = mtod(m, caddr_t);        /* Points to ip header. */
1456         payload = m->m_len - off;       /* Size of payload. */
1457
1458         if (payload == 1 && data[off] == '\xff')
1459                 return (m);             /* NB: keepalive packet, no decap. */
1460
1461         up = intoudpcb(inp);
1462         KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
1463         KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
1464             ("u_flags 0x%x", up->u_flags));
1465
1466         /*
1467          * Check that the payload is large enough to hold an
1468          * ESP header and compute the amount of data to remove.
1469          *
1470          * NB: the caller has already done a pullup for us.
1471          * XXX can we assume alignment and eliminate bcopys?
1472          */
1473         if (up->u_flags & UF_ESPINUDP_NON_IKE) {
1474                 /*
1475                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
1476                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
1477                  * possible AH mode non-IKE marker+non-ESP marker
1478                  * from draft-ietf-ipsec-udp-encaps-00.txt.
1479                  */
1480                 uint64_t marker;
1481
1482                 if (payload <= sizeof(uint64_t) + sizeof(struct esp))
1483                         return (m);     /* NB: no decap. */
1484                 bcopy(data + off, &marker, sizeof(uint64_t));
1485                 if (marker != 0)        /* Non-IKE marker. */
1486                         return (m);     /* NB: no decap. */
1487                 skip = sizeof(uint64_t) + sizeof(struct udphdr);
1488         } else {
1489                 uint32_t spi;
1490
1491                 if (payload <= sizeof(struct esp)) {
1492                         IPSECSTAT_INC(ips_in_inval);
1493                         m_freem(m);
1494                         return (NULL);  /* Discard. */
1495                 }
1496                 bcopy(data + off, &spi, sizeof(uint32_t));
1497                 if (spi == 0)           /* Non-ESP marker. */
1498                         return (m);     /* NB: no decap. */
1499                 skip = sizeof(struct udphdr);
1500         }
1501
1502         /*
1503          * Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
1504          * the UDP ports. This is required if we want to select
1505          * the right SPD for multiple hosts behind same NAT.
1506          *
1507          * NB: ports are maintained in network byte order everywhere
1508          *     in the NAT-T code.
1509          */
1510         tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
1511                 2 * sizeof(uint16_t), M_NOWAIT);
1512         if (tag == NULL) {
1513                 IPSECSTAT_INC(ips_in_nomem);
1514                 m_freem(m);
1515                 return (NULL);          /* Discard. */
1516         }
1517         iphlen = off - sizeof(struct udphdr);
1518         udphdr = (struct udphdr *)(data + iphlen);
1519         ((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
1520         ((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
1521         m_tag_prepend(m, tag);
1522
1523         /*
1524          * Remove the UDP header (and possibly the non ESP marker)
1525          * IP header length is iphlen
1526          * Before:
1527          *   <--- off --->
1528          *   +----+------+-----+
1529          *   | IP |  UDP | ESP |
1530          *   +----+------+-----+
1531          *        <-skip->
1532          * After:
1533          *          +----+-----+
1534          *          | IP | ESP |
1535          *          +----+-----+
1536          *   <-skip->
1537          */
1538         ovbcopy(data, data + skip, iphlen);
1539         m_adj(m, skip);
1540
1541         ip = mtod(m, struct ip *);
1542         ip->ip_len = htons(ntohs(ip->ip_len) - skip);
1543         ip->ip_p = IPPROTO_ESP;
1544
1545         /*
1546          * We cannot yet update the cksums so clear any
1547          * h/w cksum flags as they are no longer valid.
1548          */
1549         if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
1550                 m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
1551
1552         (void) ipsec4_common_input(m, iphlen, ip->ip_p);
1553         return (NULL);                  /* NB: consumed, bypass processing. */
1554 }
1555 #endif /* defined(IPSEC) && defined(IPSEC_NAT_T) */
1556
1557 static void
1558 udp_abort(struct socket *so)
1559 {
1560         struct inpcb *inp;
1561         struct inpcbinfo *pcbinfo;
1562
1563         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1564         inp = sotoinpcb(so);
1565         KASSERT(inp != NULL, ("udp_abort: inp == NULL"));
1566         INP_WLOCK(inp);
1567         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1568                 INP_HASH_WLOCK(pcbinfo);
1569                 in_pcbdisconnect(inp);
1570                 inp->inp_laddr.s_addr = INADDR_ANY;
1571                 INP_HASH_WUNLOCK(pcbinfo);
1572                 soisdisconnected(so);
1573         }
1574         INP_WUNLOCK(inp);
1575 }
1576
1577 static int
1578 udp_attach(struct socket *so, int proto, struct thread *td)
1579 {
1580         struct inpcb *inp;
1581         struct inpcbinfo *pcbinfo;
1582         int error;
1583
1584         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1585         inp = sotoinpcb(so);
1586         KASSERT(inp == NULL, ("udp_attach: inp != NULL"));
1587         error = soreserve(so, udp_sendspace, udp_recvspace);
1588         if (error)
1589                 return (error);
1590         INP_INFO_WLOCK(pcbinfo);
1591         error = in_pcballoc(so, pcbinfo);
1592         if (error) {
1593                 INP_INFO_WUNLOCK(pcbinfo);
1594                 return (error);
1595         }
1596
1597         inp = sotoinpcb(so);
1598         inp->inp_vflag |= INP_IPV4;
1599         inp->inp_ip_ttl = V_ip_defttl;
1600
1601         error = udp_newudpcb(inp);
1602         if (error) {
1603                 in_pcbdetach(inp);
1604                 in_pcbfree(inp);
1605                 INP_INFO_WUNLOCK(pcbinfo);
1606                 return (error);
1607         }
1608
1609         INP_WUNLOCK(inp);
1610         INP_INFO_WUNLOCK(pcbinfo);
1611         return (0);
1612 }
1613 #endif /* INET */
1614
1615 int
1616 udp_set_kernel_tunneling(struct socket *so, udp_tun_func_t f)
1617 {
1618         struct inpcb *inp;
1619         struct udpcb *up;
1620
1621         KASSERT(so->so_type == SOCK_DGRAM,
1622             ("udp_set_kernel_tunneling: !dgram"));
1623         inp = sotoinpcb(so);
1624         KASSERT(inp != NULL, ("udp_set_kernel_tunneling: inp == NULL"));
1625         INP_WLOCK(inp);
1626         up = intoudpcb(inp);
1627         if (up->u_tun_func != NULL) {
1628                 INP_WUNLOCK(inp);
1629                 return (EBUSY);
1630         }
1631         up->u_tun_func = f;
1632         INP_WUNLOCK(inp);
1633         return (0);
1634 }
1635
1636 #ifdef INET
1637 static int
1638 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1639 {
1640         struct inpcb *inp;
1641         struct inpcbinfo *pcbinfo;
1642         int error;
1643
1644         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1645         inp = sotoinpcb(so);
1646         KASSERT(inp != NULL, ("udp_bind: inp == NULL"));
1647         INP_WLOCK(inp);
1648         INP_HASH_WLOCK(pcbinfo);
1649         error = in_pcbbind(inp, nam, td->td_ucred);
1650         INP_HASH_WUNLOCK(pcbinfo);
1651         INP_WUNLOCK(inp);
1652         return (error);
1653 }
1654
1655 static void
1656 udp_close(struct socket *so)
1657 {
1658         struct inpcb *inp;
1659         struct inpcbinfo *pcbinfo;
1660
1661         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1662         inp = sotoinpcb(so);
1663         KASSERT(inp != NULL, ("udp_close: inp == NULL"));
1664         INP_WLOCK(inp);
1665         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1666                 INP_HASH_WLOCK(pcbinfo);
1667                 in_pcbdisconnect(inp);
1668                 inp->inp_laddr.s_addr = INADDR_ANY;
1669                 INP_HASH_WUNLOCK(pcbinfo);
1670                 soisdisconnected(so);
1671         }
1672         INP_WUNLOCK(inp);
1673 }
1674
1675 static int
1676 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1677 {
1678         struct inpcb *inp;
1679         struct inpcbinfo *pcbinfo;
1680         struct sockaddr_in *sin;
1681         int error;
1682
1683         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1684         inp = sotoinpcb(so);
1685         KASSERT(inp != NULL, ("udp_connect: inp == NULL"));
1686         INP_WLOCK(inp);
1687         if (inp->inp_faddr.s_addr != INADDR_ANY) {
1688                 INP_WUNLOCK(inp);
1689                 return (EISCONN);
1690         }
1691         sin = (struct sockaddr_in *)nam;
1692         error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
1693         if (error != 0) {
1694                 INP_WUNLOCK(inp);
1695                 return (error);
1696         }
1697         INP_HASH_WLOCK(pcbinfo);
1698         error = in_pcbconnect(inp, nam, td->td_ucred);
1699         INP_HASH_WUNLOCK(pcbinfo);
1700         if (error == 0)
1701                 soisconnected(so);
1702         INP_WUNLOCK(inp);
1703         return (error);
1704 }
1705
1706 static void
1707 udp_detach(struct socket *so)
1708 {
1709         struct inpcb *inp;
1710         struct inpcbinfo *pcbinfo;
1711         struct udpcb *up;
1712
1713         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1714         inp = sotoinpcb(so);
1715         KASSERT(inp != NULL, ("udp_detach: inp == NULL"));
1716         KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
1717             ("udp_detach: not disconnected"));
1718         INP_INFO_WLOCK(pcbinfo);
1719         INP_WLOCK(inp);
1720         up = intoudpcb(inp);
1721         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1722         inp->inp_ppcb = NULL;
1723         in_pcbdetach(inp);
1724         in_pcbfree(inp);
1725         INP_INFO_WUNLOCK(pcbinfo);
1726         udp_discardcb(up);
1727 }
1728
1729 static int
1730 udp_disconnect(struct socket *so)
1731 {
1732         struct inpcb *inp;
1733         struct inpcbinfo *pcbinfo;
1734
1735         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1736         inp = sotoinpcb(so);
1737         KASSERT(inp != NULL, ("udp_disconnect: inp == NULL"));
1738         INP_WLOCK(inp);
1739         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1740                 INP_WUNLOCK(inp);
1741                 return (ENOTCONN);
1742         }
1743         INP_HASH_WLOCK(pcbinfo);
1744         in_pcbdisconnect(inp);
1745         inp->inp_laddr.s_addr = INADDR_ANY;
1746         INP_HASH_WUNLOCK(pcbinfo);
1747         SOCK_LOCK(so);
1748         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1749         SOCK_UNLOCK(so);
1750         INP_WUNLOCK(inp);
1751         return (0);
1752 }
1753
1754 static int
1755 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1756     struct mbuf *control, struct thread *td)
1757 {
1758         struct inpcb *inp;
1759
1760         inp = sotoinpcb(so);
1761         KASSERT(inp != NULL, ("udp_send: inp == NULL"));
1762         return (udp_output(inp, m, addr, control, td));
1763 }
1764 #endif /* INET */
1765
1766 int
1767 udp_shutdown(struct socket *so)
1768 {
1769         struct inpcb *inp;
1770
1771         inp = sotoinpcb(so);
1772         KASSERT(inp != NULL, ("udp_shutdown: inp == NULL"));
1773         INP_WLOCK(inp);
1774         socantsendmore(so);
1775         INP_WUNLOCK(inp);
1776         return (0);
1777 }
1778
1779 #ifdef INET
1780 struct pr_usrreqs udp_usrreqs = {
1781         .pru_abort =            udp_abort,
1782         .pru_attach =           udp_attach,
1783         .pru_bind =             udp_bind,
1784         .pru_connect =          udp_connect,
1785         .pru_control =          in_control,
1786         .pru_detach =           udp_detach,
1787         .pru_disconnect =       udp_disconnect,
1788         .pru_peeraddr =         in_getpeeraddr,
1789         .pru_send =             udp_send,
1790         .pru_soreceive =        soreceive_dgram,
1791         .pru_sosend =           sosend_dgram,
1792         .pru_shutdown =         udp_shutdown,
1793         .pru_sockaddr =         in_getsockaddr,
1794         .pru_sosetlabel =       in_pcbsosetlabel,
1795         .pru_close =            udp_close,
1796 };
1797 #endif /* INET */