sys/netinet/udp_usrreq.c

   1 /*
   2  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  34  * $FreeBSD$
  35  */
  36
  37 #include "opt_ipsec.h"
  38 #include "opt_inet6.h"
  39 #include "opt_mac.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/domain.h>
  44 #include <sys/jail.h>
  45 #include <sys/kernel.h>
  46 #include <sys/lock.h>
  47 #include <sys/mac.h>
  48 #include <sys/malloc.h>
  49 #include <sys/mbuf.h>
  50 #include <sys/proc.h>
  51 #include <sys/protosw.h>
  52 #include <sys/signalvar.h>
  53 #include <sys/socket.h>
  54 #include <sys/socketvar.h>
  55 #include <sys/sx.h>
  56 #include <sys/sysctl.h>
  57 #include <sys/syslog.h>
  58
  59 #include <vm/uma.h>
  60
  61 #include <net/if.h>
  62 #include <net/route.h>
  63
  64 #include <netinet/in.h>
  65 #include <netinet/in_systm.h>
  66 #include <netinet/in_pcb.h>
  67 #include <netinet/in_var.h>
  68 #include <netinet/ip.h>
  69 #ifdef INET6
  70 #include <netinet/ip6.h>
  71 #endif
  72 #include <netinet/ip_icmp.h>
  73 #include <netinet/icmp_var.h>
  74 #include <netinet/ip_var.h>
  75 #ifdef INET6
  76 #include <netinet6/ip6_var.h>
  77 #endif
  78 #include <netinet/udp.h>
  79 #include <netinet/udp_var.h>
  80
  81 #ifdef FAST_IPSEC
  82 #include <netipsec/ipsec.h>
  83 #endif /*FAST_IPSEC*/
  84
  85 #ifdef IPSEC
  86 #include <netinet6/ipsec.h>
  87 #endif /*IPSEC*/
  88
  89 #include <machine/in_cksum.h>
  90
  91 /*
  92  * UDP protocol implementation.
  93  * Per RFC 768, August, 1980.
  94  */
  95 #ifndef COMPAT_42
  96 static int      udpcksum = 1;
  97 #else
  98 static int      udpcksum = 0;           /* XXX */
  99 #endif
 100 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
 101                 &udpcksum, 0, "");
 102
 103 int     log_in_vain = 0;
 104 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
 105     &log_in_vain, 0, "Log all incoming UDP packets");
 106
 107 static int      blackhole = 0;
 108 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
 109         &blackhole, 0, "Do not send port unreachables for refused connects");
 110
 111 struct  inpcbhead udb;          /* from udp_var.h */
 112 #define udb6    udb  /* for KAME src sync over BSD*'s */
 113 struct  inpcbinfo udbinfo;
 114
 115 #ifndef UDBHASHSIZE
 116 #define UDBHASHSIZE 16
 117 #endif
 118
 119 struct  udpstat udpstat;        /* from udp_var.h */
 120 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW,
 121     &udpstat, udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
 122
 123 static struct   sockaddr_in udp_in = { sizeof(udp_in), AF_INET };
 124 #ifdef INET6
 125 struct udp_in6 {
 126         struct sockaddr_in6     uin6_sin;
 127         u_char                  uin6_init_done : 1;
 128 } udp_in6 = {
 129         { sizeof(udp_in6.uin6_sin), AF_INET6 },
 130         0
 131 };
 132 struct udp_ip6 {
 133         struct ip6_hdr          uip6_ip6;
 134         u_char                  uip6_init_done : 1;
 135 } udp_ip6;
 136 #endif /* INET6 */
 137
 138 static void udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n,
 139                 int off);
 140 #ifdef INET6
 141 static void ip_2_ip6_hdr(struct ip6_hdr *ip6, struct ip *ip);
 142 #endif
 143
 144 static int udp_detach(struct socket *so);
 145 static  int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
 146                 struct mbuf *, struct thread *);
 147
 148 void
 149 udp_init()
 150 {
 151         INP_INFO_LOCK_INIT(&udbinfo, "udp");
 152         LIST_INIT(&udb);
 153         udbinfo.listhead = &udb;
 154         udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask);
 155         udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB,
 156                                         &udbinfo.porthashmask);
 157         udbinfo.ipi_zone = uma_zcreate("udpcb", sizeof(struct inpcb), NULL,
 158             NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 159         uma_zone_set_max(udbinfo.ipi_zone, maxsockets);
 160 }
 161
 162 void
 163 udp_input(m, off)
 164         register struct mbuf *m;
 165         int off;
 166 {
 167         int iphlen = off;
 168         register struct ip *ip;
 169         register struct udphdr *uh;
 170         register struct inpcb *inp;
 171         struct mbuf *opts = 0;
 172         int len;
 173         struct ip save_ip;
 174
 175         udpstat.udps_ipackets++;
 176
 177         /*
 178          * Strip IP options, if any; should skip this,
 179          * make available to user, and use on returned packets,
 180          * but we don't yet have a way to check the checksum
 181          * with options still present.
 182          */
 183         if (iphlen > sizeof (struct ip)) {
 184                 ip_stripoptions(m, (struct mbuf *)0);
 185                 iphlen = sizeof(struct ip);
 186         }
 187
 188         /*
 189          * Get IP and UDP header together in first mbuf.
 190          */
 191         ip = mtod(m, struct ip *);
 192         if (m->m_len < iphlen + sizeof(struct udphdr)) {
 193                 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
 194                         udpstat.udps_hdrops++;
 195                         return;
 196                 }
 197                 ip = mtod(m, struct ip *);
 198         }
 199         uh = (struct udphdr *)((caddr_t)ip + iphlen);
 200
 201         /* destination port of 0 is illegal, based on RFC768. */
 202         if (uh->uh_dport == 0)
 203                 goto badunlocked;
 204
 205         /*
 206          * Construct sockaddr format source address.
 207          * Stuff source address and datagram in user buffer.
 208          */
 209         udp_in.sin_port = uh->uh_sport;
 210         udp_in.sin_addr = ip->ip_src;
 211 #ifdef INET6
 212         udp_in6.uin6_init_done = udp_ip6.uip6_init_done = 0;
 213 #endif
 214
 215         /*
 216          * Make mbuf data length reflect UDP length.
 217          * If not enough data to reflect UDP length, drop.
 218          */
 219         len = ntohs((u_short)uh->uh_ulen);
 220         if (ip->ip_len != len) {
 221                 if (len > ip->ip_len || len < sizeof(struct udphdr)) {
 222                         udpstat.udps_badlen++;
 223                         goto badunlocked;
 224                 }
 225                 m_adj(m, len - ip->ip_len);
 226                 /* ip->ip_len = len; */
 227         }
 228         /*
 229          * Save a copy of the IP header in case we want restore it
 230          * for sending an ICMP error message in response.
 231          */
 232         if (!blackhole)
 233                 save_ip = *ip;
 234
 235         /*
 236          * Checksum extended UDP header and data.
 237          */
 238         if (uh->uh_sum) {
 239                 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
 240                         if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 241                                 uh->uh_sum = m->m_pkthdr.csum_data;
 242                         else
 243                                 uh->uh_sum = in_pseudo(ip->ip_src.s_addr,
 244                                     ip->ip_dst.s_addr, htonl((u_short)len +
 245                                     m->m_pkthdr.csum_data + IPPROTO_UDP));
 246                         uh->uh_sum ^= 0xffff;
 247                 } else {
 248                         char b[9];
 249                         bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
 250                         bzero(((struct ipovly *)ip)->ih_x1, 9);
 251                         ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 252                         uh->uh_sum = in_cksum(m, len + sizeof (struct ip));
 253                         bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
 254                 }
 255                 if (uh->uh_sum) {
 256                         udpstat.udps_badsum++;
 257                         m_freem(m);
 258                         return;
 259                 }
 260         } else
 261                 udpstat.udps_nosum++;
 262
 263         INP_INFO_RLOCK(&udbinfo);
 264
 265         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
 266             in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
 267                 struct inpcb *last;
 268                 /*
 269                  * Deliver a multicast or broadcast datagram to *all* sockets
 270                  * for which the local and remote addresses and ports match
 271                  * those of the incoming datagram.  This allows more than
 272                  * one process to receive multi/broadcasts on the same port.
 273                  * (This really ought to be done for unicast datagrams as
 274                  * well, but that would cause problems with existing
 275                  * applications that open both address-specific sockets and
 276                  * a wildcard socket listening to the same port -- they would
 277                  * end up receiving duplicates of every unicast datagram.
 278                  * Those applications open the multiple sockets to overcome an
 279                  * inadequacy of the UDP socket interface, but for backwards
 280                  * compatibility we avoid the problem here rather than
 281                  * fixing the interface.  Maybe 4.5BSD will remedy this?)
 282                  */
 283
 284                 /*
 285                  * Locate pcb(s) for datagram.
 286                  * (Algorithm copied from raw_intr().)
 287                  */
 288                 last = NULL;
 289                 LIST_FOREACH(inp, &udb, inp_list) {
 290                         INP_LOCK(inp);
 291                         if (inp->inp_lport != uh->uh_dport) {
 292                 docontinue:
 293                                 INP_UNLOCK(inp);
 294                                 continue;
 295                         }
 296 #ifdef INET6
 297                         if ((inp->inp_vflag & INP_IPV4) == 0)
 298                                 goto docontinue;
 299 #endif
 300                         if (inp->inp_laddr.s_addr != INADDR_ANY) {
 301                                 if (inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
 302                                         goto docontinue;
 303                         }
 304                         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 305                                 if (inp->inp_faddr.s_addr !=
 306                                     ip->ip_src.s_addr ||
 307                                     inp->inp_fport != uh->uh_sport)
 308                                         goto docontinue;
 309                         }
 310
 311                         if (last != NULL) {
 312                                 struct mbuf *n;
 313
 314                                 n = m_copy(m, 0, M_COPYALL);
 315                                 if (n != NULL)
 316                                         udp_append(last, ip, n,
 317                                                    iphlen +
 318                                                    sizeof(struct udphdr));
 319                                 INP_UNLOCK(last);
 320                         }
 321                         last = inp;
 322                         /*
 323                          * Don't look for additional matches if this one does
 324                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 325                          * socket options set.  This heuristic avoids searching
 326                          * through all pcbs in the common case of a non-shared
 327                          * port.  It * assumes that an application will never
 328                          * clear these options after setting them.
 329                          */
 330                         if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR)) == 0)
 331                                 break;
 332                 }
 333
 334                 if (last == NULL) {
 335                         /*
 336                          * No matching pcb found; discard datagram.
 337                          * (No need to send an ICMP Port Unreachable
 338                          * for a broadcast or multicast datgram.)
 339                          */
 340                         udpstat.udps_noportbcast++;
 341                         goto badheadlocked;
 342                 }
 343                 INP_INFO_RUNLOCK(&udbinfo);
 344                 udp_append(last, ip, m, iphlen + sizeof(struct udphdr));
 345                 INP_UNLOCK(last);
 346                 return;
 347         }
 348         /*
 349          * Locate pcb for datagram.
 350          */
 351         inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
 352             ip->ip_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
 353         if (inp == NULL) {
 354                 if (log_in_vain) {
 355                         char buf[4*sizeof "123"];
 356
 357                         strcpy(buf, inet_ntoa(ip->ip_dst));
 358                         log(LOG_INFO,
 359                             "Connection attempt to UDP %s:%d from %s:%d\n",
 360                             buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
 361                             ntohs(uh->uh_sport));
 362                 }
 363                 udpstat.udps_noport++;
 364                 if (m->m_flags & (M_BCAST | M_MCAST)) {
 365                         udpstat.udps_noportbcast++;
 366                         goto badheadlocked;
 367                 }
 368                 if (blackhole)
 369                         goto badheadlocked;
 370                 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
 371                         goto badheadlocked;
 372                 *ip = save_ip;
 373                 ip->ip_len += iphlen;
 374                 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
 375                 INP_INFO_RUNLOCK(&udbinfo);
 376                 return;
 377         }
 378         INP_LOCK(inp);
 379         INP_INFO_RUNLOCK(&udbinfo);
 380         udp_append(inp, ip, m, iphlen + sizeof(struct udphdr));
 381         INP_UNLOCK(inp);
 382         return;
 383
 384 badheadlocked:
 385         INP_INFO_RUNLOCK(&udbinfo);
 386         if (inp)
 387                 INP_UNLOCK(inp);
 388 badunlocked:
 389         m_freem(m);
 390         if (opts)
 391                 m_freem(opts);
 392         return;
 393 }
 394
 395 #ifdef INET6
 396 static void
 397 ip_2_ip6_hdr(ip6, ip)
 398         struct ip6_hdr *ip6;
 399         struct ip *ip;
 400 {
 401         bzero(ip6, sizeof(*ip6));
 402
 403         ip6->ip6_vfc = IPV6_VERSION;
 404         ip6->ip6_plen = ip->ip_len;
 405         ip6->ip6_nxt = ip->ip_p;
 406         ip6->ip6_hlim = ip->ip_ttl;
 407         ip6->ip6_src.s6_addr32[2] = ip6->ip6_dst.s6_addr32[2] =
 408                 IPV6_ADDR_INT32_SMP;
 409         ip6->ip6_src.s6_addr32[3] = ip->ip_src.s_addr;
 410         ip6->ip6_dst.s6_addr32[3] = ip->ip_dst.s_addr;
 411 }
 412 #endif
 413
 414 /*
 415  * subroutine of udp_input(), mainly for source code readability.
 416  * caller must properly init udp_ip6 and udp_in6 beforehand.
 417  */
 418 static void
 419 udp_append(last, ip, n, off)
 420         struct inpcb *last;
 421         struct ip *ip;
 422         struct mbuf *n;
 423         int off;
 424 {
 425         struct sockaddr *append_sa;
 426         struct mbuf *opts = 0;
 427
 428 #ifdef IPSEC
 429         /* check AH/ESP integrity. */
 430         if (ipsec4_in_reject_so(n, last->inp_socket)) {
 431                 ipsecstat.in_polvio++;
 432                 m_freem(n);
 433                 return;
 434         }
 435 #endif /*IPSEC*/
 436 #ifdef FAST_IPSEC
 437         /* check AH/ESP integrity. */
 438         if (ipsec4_in_reject(n, last)) {
 439                 m_freem(n);
 440                 return;
 441         }
 442 #endif /*FAST_IPSEC*/
 443 #ifdef MAC
 444         if (mac_check_socket_deliver(last->inp_socket, n) != 0) {
 445                 m_freem(n);
 446                 return;
 447         }
 448 #endif
 449         if (last->inp_flags & INP_CONTROLOPTS ||
 450             last->inp_socket->so_options & SO_TIMESTAMP) {
 451 #ifdef INET6
 452                 if (last->inp_vflag & INP_IPV6) {
 453                         int savedflags;
 454
 455                         if (udp_ip6.uip6_init_done == 0) {
 456                                 ip_2_ip6_hdr(&udp_ip6.uip6_ip6, ip);
 457                                 udp_ip6.uip6_init_done = 1;
 458                         }
 459                         savedflags = last->inp_flags;
 460                         last->inp_flags &= ~INP_UNMAPPABLEOPTS;
 461                         ip6_savecontrol(last, &opts, &udp_ip6.uip6_ip6, n);
 462                         last->inp_flags = savedflags;
 463                 } else
 464 #endif
 465                 ip_savecontrol(last, &opts, ip, n);
 466         }
 467 #ifdef INET6
 468         if (last->inp_vflag & INP_IPV6) {
 469                 if (udp_in6.uin6_init_done == 0) {
 470                         in6_sin_2_v4mapsin6(&udp_in, &udp_in6.uin6_sin);
 471                         udp_in6.uin6_init_done = 1;
 472                 }
 473                 append_sa = (struct sockaddr *)&udp_in6.uin6_sin;
 474         } else
 475 #endif
 476         append_sa = (struct sockaddr *)&udp_in;
 477         m_adj(n, off);
 478         if (sbappendaddr(&last->inp_socket->so_rcv, append_sa, n, opts) == 0) {
 479                 m_freem(n);
 480                 if (opts)
 481                         m_freem(opts);
 482                 udpstat.udps_fullsock++;
 483         } else
 484                 sorwakeup(last->inp_socket);
 485 }
 486
 487 /*
 488  * Notify a udp user of an asynchronous error;
 489  * just wake up so that he can collect error status.
 490  */
 491 struct inpcb *
 492 udp_notify(inp, errno)
 493         register struct inpcb *inp;
 494         int errno;
 495 {
 496         inp->inp_socket->so_error = errno;
 497         sorwakeup(inp->inp_socket);
 498         sowwakeup(inp->inp_socket);
 499         return inp;
 500 }
 501
 502 void
 503 udp_ctlinput(cmd, sa, vip)
 504         int cmd;
 505         struct sockaddr *sa;
 506         void *vip;
 507 {
 508         struct ip *ip = vip;
 509         struct udphdr *uh;
 510         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 511         struct in_addr faddr;
 512         struct inpcb *inp;
 513         int s;
 514
 515         faddr = ((struct sockaddr_in *)sa)->sin_addr;
 516         if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
 517                 return;
 518
 519         if (PRC_IS_REDIRECT(cmd)) {
 520                 ip = 0;
 521                 notify = in_rtchange;
 522         } else if (cmd == PRC_HOSTDEAD)
 523                 ip = 0;
 524         else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
 525                 return;
 526         if (ip) {
 527                 s = splnet();
 528                 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
 529                 INP_INFO_RLOCK(&udbinfo);
 530                 inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
 531                     ip->ip_src, uh->uh_sport, 0, NULL);
 532                 if (inp != NULL) {
 533                         INP_LOCK(inp);
 534                         if (inp->inp_socket != NULL) {
 535                                 (*notify)(inp, inetctlerrmap[cmd]);
 536                         }
 537                         INP_UNLOCK(inp);
 538                 }
 539                 INP_INFO_RUNLOCK(&udbinfo);
 540                 splx(s);
 541         } else
 542                 in_pcbnotifyall(&udbinfo, faddr, inetctlerrmap[cmd], notify);
 543 }
 544
 545 static int
 546 udp_pcblist(SYSCTL_HANDLER_ARGS)
 547 {
 548         int error, i, n, s;
 549         struct inpcb *inp, **inp_list;
 550         inp_gen_t gencnt;
 551         struct xinpgen xig;
 552
 553         /*
 554          * The process of preparing the TCB list is too time-consuming and
 555          * resource-intensive to repeat twice on every request.
 556          */
 557         if (req->oldptr == 0) {
 558                 n = udbinfo.ipi_count;
 559                 req->oldidx = 2 * (sizeof xig)
 560                         + (n + n/8) * sizeof(struct xinpcb);
 561                 return 0;
 562         }
 563
 564         if (req->newptr != 0)
 565                 return EPERM;
 566
 567         /*
 568          * OK, now we're committed to doing something.
 569          */
 570         s = splnet();
 571         INP_INFO_RLOCK(&udbinfo);
 572         gencnt = udbinfo.ipi_gencnt;
 573         n = udbinfo.ipi_count;
 574         INP_INFO_RUNLOCK(&udbinfo);
 575         splx(s);
 576
 577         sysctl_wire_old_buffer(req, 2 * (sizeof xig)
 578                 + n * sizeof(struct xinpcb));
 579
 580         xig.xig_len = sizeof xig;
 581         xig.xig_count = n;
 582         xig.xig_gen = gencnt;
 583         xig.xig_sogen = so_gencnt;
 584         error = SYSCTL_OUT(req, &xig, sizeof xig);
 585         if (error)
 586                 return error;
 587
 588         inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
 589         if (inp_list == 0)
 590                 return ENOMEM;
 591
 592         s = splnet();
 593         INP_INFO_RLOCK(&udbinfo);
 594         for (inp = LIST_FIRST(udbinfo.listhead), i = 0; inp && i < n;
 595              inp = LIST_NEXT(inp, inp_list)) {
 596                 INP_LOCK(inp);
 597                 if (inp->inp_gencnt <= gencnt &&
 598                     cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
 599                         inp_list[i++] = inp;
 600                 INP_UNLOCK(inp);
 601         }
 602         INP_INFO_RUNLOCK(&udbinfo);
 603         splx(s);
 604         n = i;
 605
 606         error = 0;
 607         for (i = 0; i < n; i++) {
 608                 inp = inp_list[i];
 609                 if (inp->inp_gencnt <= gencnt) {
 610                         struct xinpcb xi;
 611                         xi.xi_len = sizeof xi;
 612                         /* XXX should avoid extra copy */
 613                         bcopy(inp, &xi.xi_inp, sizeof *inp);
 614                         if (inp->inp_socket)
 615                                 sotoxsocket(inp->inp_socket, &xi.xi_socket);
 616                         xi.xi_inp.inp_gencnt = inp->inp_gencnt;
 617                         error = SYSCTL_OUT(req, &xi, sizeof xi);
 618                 }
 619         }
 620         if (!error) {
 621                 /*
 622                  * Give the user an updated idea of our state.
 623                  * If the generation differs from what we told
 624                  * her before, she knows that something happened
 625                  * while we were processing this request, and it
 626                  * might be necessary to retry.
 627                  */
 628                 s = splnet();
 629                 INP_INFO_RLOCK(&udbinfo);
 630                 xig.xig_gen = udbinfo.ipi_gencnt;
 631                 xig.xig_sogen = so_gencnt;
 632                 xig.xig_count = udbinfo.ipi_count;
 633                 INP_INFO_RUNLOCK(&udbinfo);
 634                 splx(s);
 635                 error = SYSCTL_OUT(req, &xig, sizeof xig);
 636         }
 637         free(inp_list, M_TEMP);
 638         return error;
 639 }
 640
 641 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
 642             udp_pcblist, "S,xinpcb", "List of active UDP sockets");
 643
 644 static int
 645 udp_getcred(SYSCTL_HANDLER_ARGS)
 646 {
 647         struct xucred xuc;
 648         struct sockaddr_in addrs[2];
 649         struct inpcb *inp;
 650         int error, s;
 651
 652         error = suser_cred(req->td->td_ucred, PRISON_ROOT);
 653         if (error)
 654                 return (error);
 655         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 656         if (error)
 657                 return (error);
 658         s = splnet();
 659         INP_INFO_RLOCK(&udbinfo);
 660         inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port,
 661                                 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL);
 662         if (inp == NULL || inp->inp_socket == NULL) {
 663                 error = ENOENT;
 664                 goto out;
 665         }
 666         error = cr_canseesocket(req->td->td_ucred, inp->inp_socket);
 667         if (error)
 668                 goto out;
 669         cru2x(inp->inp_socket->so_cred, &xuc);
 670 out:
 671         INP_INFO_RUNLOCK(&udbinfo);
 672         splx(s);
 673         if (error == 0)
 674                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 675         return (error);
 676 }
 677
 678 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred,
 679     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
 680     udp_getcred, "S,xucred", "Get the xucred of a UDP connection");
 681
 682 static int
 683 udp_output(inp, m, addr, control, td)
 684         register struct inpcb *inp;
 685         struct mbuf *m;
 686         struct sockaddr *addr;
 687         struct mbuf *control;
 688         struct thread *td;
 689 {
 690         register struct udpiphdr *ui;
 691         register int len = m->m_pkthdr.len;
 692         struct in_addr faddr, laddr;
 693         struct cmsghdr *cm;
 694         struct sockaddr_in *sin, src;
 695         int error = 0;
 696         int ipflags;
 697         u_short fport, lport;
 698
 699 #ifdef MAC
 700         mac_create_mbuf_from_socket(inp->inp_socket, m);
 701 #endif
 702
 703         if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
 704                 error = EMSGSIZE;
 705                 if (control)
 706                         m_freem(control);
 707                 goto release;
 708         }
 709
 710         src.sin_addr.s_addr = INADDR_ANY;
 711         if (control != NULL) {
 712                 /*
 713                  * XXX: Currently, we assume all the optional information
 714                  * is stored in a single mbuf.
 715                  */
 716                 if (control->m_next) {
 717                         error = EINVAL;
 718                         m_freem(control);
 719                         goto release;
 720                 }
 721                 for (; control->m_len > 0;
 722                     control->m_data += CMSG_ALIGN(cm->cmsg_len),
 723                     control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
 724                         cm = mtod(control, struct cmsghdr *);
 725                         if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0 ||
 726                             cm->cmsg_len > control->m_len) {
 727                                 error = EINVAL;
 728                                 break;
 729                         }
 730                         if (cm->cmsg_level != IPPROTO_IP)
 731                                 continue;
 732
 733                         switch (cm->cmsg_type) {
 734                         case IP_SENDSRCADDR:
 735                                 if (cm->cmsg_len !=
 736                                     CMSG_LEN(sizeof(struct in_addr))) {
 737                                         error = EINVAL;
 738                                         break;
 739                                 }
 740                                 bzero(&src, sizeof(src));
 741                                 src.sin_family = AF_INET;
 742                                 src.sin_len = sizeof(src);
 743                                 src.sin_port = inp->inp_lport;
 744                                 src.sin_addr = *(struct in_addr *)CMSG_DATA(cm);
 745                                 break;
 746                         default:
 747                                 error = ENOPROTOOPT;
 748                                 break;
 749                         }
 750                         if (error)
 751                                 break;
 752                 }
 753                 m_freem(control);
 754         }
 755         if (error)
 756                 goto release;
 757         laddr = inp->inp_laddr;
 758         lport = inp->inp_lport;
 759         if (src.sin_addr.s_addr != INADDR_ANY) {
 760                 if (lport == 0) {
 761                         error = EINVAL;
 762                         goto release;
 763                 }
 764                 error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
 765                     &laddr.s_addr, &lport, td);
 766                 if (error)
 767                         goto release;
 768         }
 769
 770         if (addr) {
 771                 sin = (struct sockaddr_in *)addr;
 772                 if (td && jailed(td->td_ucred))
 773                         prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr);
 774                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
 775                         error = EISCONN;
 776                         goto release;
 777                 }
 778                 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr, &lport,
 779                     &faddr.s_addr, &fport, NULL, td);
 780                 if (error)
 781                         goto release;
 782
 783                 /* Commit the local port if newly assigned. */
 784                 if (inp->inp_laddr.s_addr == INADDR_ANY &&
 785                     inp->inp_lport == 0) {
 786                         inp->inp_lport = lport;
 787                         if (in_pcbinshash(inp) != 0) {
 788                                 inp->inp_lport = 0;
 789                                 error = EAGAIN;
 790                                 goto release;
 791                         }
 792                         inp->inp_flags |= INP_ANONPORT;
 793                 }
 794         } else {
 795                 faddr = inp->inp_faddr;
 796                 fport = inp->inp_fport;
 797                 if (faddr.s_addr == INADDR_ANY) {
 798                         error = ENOTCONN;
 799                         goto release;
 800                 }
 801         }
 802         /*
 803          * Calculate data length and get a mbuf
 804          * for UDP and IP headers.
 805          */
 806         M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
 807         if (m == 0) {
 808                 error = ENOBUFS;
 809                 goto release;
 810         }
 811
 812         /*
 813          * Fill in mbuf with extended UDP header
 814          * and addresses and length put into network format.
 815          */
 816         ui = mtod(m, struct udpiphdr *);
 817         bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
 818         ui->ui_pr = IPPROTO_UDP;
 819         ui->ui_src = laddr;
 820         ui->ui_dst = faddr;
 821         ui->ui_sport = lport;
 822         ui->ui_dport = fport;
 823         ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
 824
 825         ipflags = inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST);
 826         if (inp->inp_flags & INP_ONESBCAST)
 827                 ipflags |= IP_SENDONES;
 828
 829         /*
 830          * Set up checksum and output datagram.
 831          */
 832         if (udpcksum) {
 833                 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, ui->ui_dst.s_addr,
 834                     htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
 835                 m->m_pkthdr.csum_flags = CSUM_UDP;
 836                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 837         } else {
 838                 ui->ui_sum = 0;
 839         }
 840         ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
 841         ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;    /* XXX */
 842         ((struct ip *)ui)->ip_tos = inp->inp_ip_tos;    /* XXX */
 843         udpstat.udps_opackets++;
 844
 845         error = ip_output(m, inp->inp_options, &inp->inp_route, ipflags,
 846             inp->inp_moptions, inp);
 847         return (error);
 848
 849 release:
 850         m_freem(m);
 851         return (error);
 852 }
 853
 854 u_long  udp_sendspace = 9216;           /* really max datagram size */
 855                                         /* 40 1K datagrams */
 856 SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
 857     &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
 858
 859 u_long  udp_recvspace = 40 * (1024 +
 860 #ifdef INET6
 861                                       sizeof(struct sockaddr_in6)
 862 #else
 863                                       sizeof(struct sockaddr_in)
 864 #endif
 865                                       );
 866 SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
 867     &udp_recvspace, 0, "Maximum incoming UDP datagram size");
 868
 869 static int
 870 udp_abort(struct socket *so)
 871 {
 872         struct inpcb *inp;
 873         int s;
 874
 875         INP_INFO_WLOCK(&udbinfo);
 876         inp = sotoinpcb(so);
 877         if (inp == 0) {
 878                 INP_INFO_WUNLOCK(&udbinfo);
 879                 return EINVAL;  /* ??? possible? panic instead? */
 880         }
 881         INP_LOCK(inp);
 882         soisdisconnected(so);
 883         s = splnet();
 884         in_pcbdetach(inp);
 885         INP_INFO_WUNLOCK(&udbinfo);
 886         splx(s);
 887         return 0;
 888 }
 889
 890 static int
 891 udp_attach(struct socket *so, int proto, struct thread *td)
 892 {
 893         struct inpcb *inp;
 894         int s, error;
 895
 896         INP_INFO_WLOCK(&udbinfo);
 897         inp = sotoinpcb(so);
 898         if (inp != 0) {
 899                 INP_INFO_WUNLOCK(&udbinfo);
 900                 return EINVAL;
 901         }
 902         error = soreserve(so, udp_sendspace, udp_recvspace);
 903         if (error) {
 904                 INP_INFO_WUNLOCK(&udbinfo);
 905                 return error;
 906         }
 907         s = splnet();
 908         error = in_pcballoc(so, &udbinfo, td);
 909         splx(s);
 910         if (error) {
 911                 INP_INFO_WUNLOCK(&udbinfo);
 912                 return error;
 913         }
 914
 915         inp = (struct inpcb *)so->so_pcb;
 916         INP_LOCK(inp);
 917         INP_INFO_WUNLOCK(&udbinfo);
 918         inp->inp_vflag |= INP_IPV4;
 919         inp->inp_ip_ttl = ip_defttl;
 920         INP_UNLOCK(inp);
 921         return 0;
 922 }
 923
 924 static int
 925 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 926 {
 927         struct inpcb *inp;
 928         int s, error;
 929
 930         INP_INFO_WLOCK(&udbinfo);
 931         inp = sotoinpcb(so);
 932         if (inp == 0) {
 933                 INP_INFO_WUNLOCK(&udbinfo);
 934                 return EINVAL;
 935         }
 936         INP_LOCK(inp);
 937         s = splnet();
 938         error = in_pcbbind(inp, nam, td);
 939         splx(s);
 940         INP_UNLOCK(inp);
 941         INP_INFO_WUNLOCK(&udbinfo);
 942         return error;
 943 }
 944
 945 static int
 946 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 947 {
 948         struct inpcb *inp;
 949         int s, error;
 950         struct sockaddr_in *sin;
 951
 952         INP_INFO_WLOCK(&udbinfo);
 953         inp = sotoinpcb(so);
 954         if (inp == 0) {
 955                 INP_INFO_WUNLOCK(&udbinfo);
 956                 return EINVAL;
 957         }
 958         INP_LOCK(inp);
 959         if (inp->inp_faddr.s_addr != INADDR_ANY) {
 960                 INP_UNLOCK(inp);
 961                 INP_INFO_WUNLOCK(&udbinfo);
 962                 return EISCONN;
 963         }
 964         s = splnet();
 965         sin = (struct sockaddr_in *)nam;
 966         if (td && jailed(td->td_ucred))
 967                 prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr);
 968         error = in_pcbconnect(inp, nam, td);
 969         splx(s);
 970         if (error == 0)
 971                 soisconnected(so);
 972         INP_UNLOCK(inp);
 973         INP_INFO_WUNLOCK(&udbinfo);
 974         return error;
 975 }
 976
 977 static int
 978 udp_detach(struct socket *so)
 979 {
 980         struct inpcb *inp;
 981         int s;
 982
 983         INP_INFO_WLOCK(&udbinfo);
 984         inp = sotoinpcb(so);
 985         if (inp == 0) {
 986                 INP_INFO_WUNLOCK(&udbinfo);
 987                 return EINVAL;
 988         }
 989         INP_LOCK(inp);
 990         s = splnet();
 991         in_pcbdetach(inp);
 992         INP_INFO_WUNLOCK(&udbinfo);
 993         splx(s);
 994         return 0;
 995 }
 996
 997 static int
 998 udp_disconnect(struct socket *so)
 999 {
1000         struct inpcb *inp;
1001         int s;
1002
1003         INP_INFO_WLOCK(&udbinfo);
1004         inp = sotoinpcb(so);
1005         if (inp == 0) {
1006                 INP_INFO_WUNLOCK(&udbinfo);
1007                 return EINVAL;
1008         }
1009         INP_LOCK(inp);
1010         if (inp->inp_faddr.s_addr == INADDR_ANY) {
1011                 INP_INFO_WUNLOCK(&udbinfo);
1012                 INP_UNLOCK(inp);
1013                 return ENOTCONN;
1014         }
1015
1016         s = splnet();
1017         in_pcbdisconnect(inp);
1018         inp->inp_laddr.s_addr = INADDR_ANY;
1019         INP_UNLOCK(inp);
1020         INP_INFO_WUNLOCK(&udbinfo);
1021         splx(s);
1022         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1023         return 0;
1024 }
1025
1026 static int
1027 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1028             struct mbuf *control, struct thread *td)
1029 {
1030         struct inpcb *inp;
1031         int ret;
1032
1033         INP_INFO_WLOCK(&udbinfo);
1034         inp = sotoinpcb(so);
1035         if (inp == 0) {
1036                 INP_INFO_WUNLOCK(&udbinfo);
1037                 m_freem(m);
1038                 return EINVAL;
1039         }
1040         INP_LOCK(inp);
1041         ret = udp_output(inp, m, addr, control, td);
1042         INP_UNLOCK(inp);
1043         INP_INFO_WUNLOCK(&udbinfo);
1044         return ret;
1045 }
1046
1047 int
1048 udp_shutdown(struct socket *so)
1049 {
1050         struct inpcb *inp;
1051
1052         INP_INFO_RLOCK(&udbinfo);
1053         inp = sotoinpcb(so);
1054         if (inp == 0) {
1055                 INP_INFO_RUNLOCK(&udbinfo);
1056                 return EINVAL;
1057         }
1058         INP_LOCK(inp);
1059         INP_INFO_RUNLOCK(&udbinfo);
1060         socantsendmore(so);
1061         INP_UNLOCK(inp);
1062         return 0;
1063 }
1064
1065 /*
1066  * This is the wrapper function for in_setsockaddr.  We just pass down
1067  * the pcbinfo for in_setsockaddr to lock.  We don't want to do the locking
1068  * here because in_setsockaddr will call malloc and might block.
1069  */
1070 static int
1071 udp_sockaddr(struct socket *so, struct sockaddr **nam)
1072 {
1073         return (in_setsockaddr(so, nam, &udbinfo));
1074 }
1075
1076 /*
1077  * This is the wrapper function for in_setpeeraddr.  We just pass down
1078  * the pcbinfo for in_setpeeraddr to lock.
1079  */
1080 static int
1081 udp_peeraddr(struct socket *so, struct sockaddr **nam)
1082 {
1083         return (in_setpeeraddr(so, nam, &udbinfo));
1084 }
1085
1086 struct pr_usrreqs udp_usrreqs = {
1087         udp_abort, pru_accept_notsupp, udp_attach, udp_bind, udp_connect,
1088         pru_connect2_notsupp, in_control, udp_detach, udp_disconnect,
1089         pru_listen_notsupp, udp_peeraddr, pru_rcvd_notsupp,
1090         pru_rcvoob_notsupp, udp_send, pru_sense_null, udp_shutdown,
1091         udp_sockaddr, sosend, soreceive, sopoll
1092 };