Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet/udp_usrreq.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 3 * The Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 4. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * @(#)udp_usrreq.c 8.6 (Berkeley) 5/23/95 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "opt_ipfw.h" 37 #include "opt_inet6.h" 38 #include "opt_ipsec.h" 39 #include "opt_mac.h" 40 41 #include <sys/param.h> 42 #include <sys/domain.h> 43 #include <sys/eventhandler.h> 44 #include <sys/jail.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/priv.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 #include <sys/systm.h> 59 60 #include <vm/uma.h> 61 62 #include <net/if.h> 63 #include <net/route.h> 64 65 #include <netinet/in.h> 66 #include <netinet/in_pcb.h> 67 #include <netinet/in_systm.h> 68 #include <netinet/in_var.h> 69 #include <netinet/ip.h> 70 #ifdef INET6 71 #include <netinet/ip6.h> 72 #endif 73 #include <netinet/ip_icmp.h> 74 #include <netinet/icmp_var.h> 75 #include <netinet/ip_var.h> 76 #include <netinet/ip_options.h> 77 #ifdef INET6 78 #include <netinet6/ip6_var.h> 79 #endif 80 #include <netinet/udp.h> 81 #include <netinet/udp_var.h> 82 83 #ifdef IPSEC 84 #include <netipsec/ipsec.h> 85 #endif 86 87 #include <machine/in_cksum.h> 88 89 #include <security/mac/mac_framework.h> 90 91 /* 92 * UDP protocol implementation. 93 * Per RFC 768, August, 1980. 94 */ 95 96 /* 97 * BSD 4.2 defaulted the udp checksum to be off. Turning off udp checksums 98 * removes the only data integrity mechanism for packets and malformed 99 * packets that would otherwise be discarded due to bad checksums, and may 100 * cause problems (especially for NFS data blocks). 101 */ 102 static int udp_cksum = 1; 103 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udp_cksum, 104 0, ""); 105 106 int udp_log_in_vain = 0; 107 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW, 108 &udp_log_in_vain, 0, "Log all incoming UDP packets"); 109 110 int udp_blackhole = 0; 111 SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW, &udp_blackhole, 0, 112 "Do not send port unreachables for refused connects"); 113 114 u_long udp_sendspace = 9216; /* really max datagram size */ 115 /* 40 1K datagrams */ 116 SYSCTL_ULONG(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW, 117 &udp_sendspace, 0, "Maximum outgoing UDP datagram size"); 118 119 u_long udp_recvspace = 40 * (1024 + 120 #ifdef INET6 121 sizeof(struct sockaddr_in6) 122 #else 123 sizeof(struct sockaddr_in) 124 #endif 125 ); 126 127 SYSCTL_ULONG(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW, 128 &udp_recvspace, 0, "Maximum space for incoming UDP datagrams"); 129 130 struct inpcbhead udb; /* from udp_var.h */ 131 struct inpcbinfo udbinfo; 132 133 #ifndef UDBHASHSIZE 134 #define UDBHASHSIZE 16 135 #endif 136 137 struct udpstat udpstat; /* from udp_var.h */ 138 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RW, &udpstat, 139 udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)"); 140 141 static void udp_detach(struct socket *so); 142 static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *, 143 struct mbuf *, struct thread *); 144 145 static void 146 udp_zone_change(void *tag) 147 { 148 149 uma_zone_set_max(udbinfo.ipi_zone, maxsockets); 150 } 151 152 static int 153 udp_inpcb_init(void *mem, int size, int flags) 154 { 155 struct inpcb *inp; 156 157 inp = mem; 158 INP_LOCK_INIT(inp, "inp", "udpinp"); 159 return (0); 160 } 161 162 void 163 udp_init(void) 164 { 165 166 INP_INFO_LOCK_INIT(&udbinfo, "udp"); 167 LIST_INIT(&udb); 168 udbinfo.ipi_listhead = &udb; 169 udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB, 170 &udbinfo.ipi_hashmask); 171 udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB, 172 &udbinfo.ipi_porthashmask); 173 udbinfo.ipi_zone = uma_zcreate("udpcb", sizeof(struct inpcb), NULL, 174 NULL, udp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 175 uma_zone_set_max(udbinfo.ipi_zone, maxsockets); 176 EVENTHANDLER_REGISTER(maxsockets_change, udp_zone_change, NULL, 177 EVENTHANDLER_PRI_ANY); 178 } 179 180 /* 181 * Subroutine of udp_input(), which appends the provided mbuf chain to the 182 * passed pcb/socket. The caller must provide a sockaddr_in via udp_in that 183 * contains the source address. If the socket ends up being an IPv6 socket, 184 * udp_append() will convert to a sockaddr_in6 before passing the address 185 * into the socket code. 186 */ 187 static void 188 udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off, 189 struct sockaddr_in *udp_in) 190 { 191 struct sockaddr *append_sa; 192 struct socket *so; 193 struct mbuf *opts = 0; 194 #ifdef INET6 195 struct sockaddr_in6 udp_in6; 196 #endif 197 198 INP_LOCK_ASSERT(inp); 199 200 #ifdef IPSEC 201 /* Check AH/ESP integrity. */ 202 if (ipsec4_in_reject(n, inp)) { 203 m_freem(n); 204 ipsec4stat.in_polvio++; 205 return; 206 } 207 #endif /* IPSEC */ 208 #ifdef MAC 209 if (mac_check_inpcb_deliver(inp, n) != 0) { 210 m_freem(n); 211 return; 212 } 213 #endif 214 if (inp->inp_flags & INP_CONTROLOPTS || 215 inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) { 216 #ifdef INET6 217 if (inp->inp_vflag & INP_IPV6) { 218 int savedflags; 219 220 savedflags = inp->inp_flags; 221 inp->inp_flags &= ~INP_UNMAPPABLEOPTS; 222 ip6_savecontrol(inp, n, &opts); 223 inp->inp_flags = savedflags; 224 } else 225 #endif 226 ip_savecontrol(inp, &opts, ip, n); 227 } 228 #ifdef INET6 229 if (inp->inp_vflag & INP_IPV6) { 230 bzero(&udp_in6, sizeof(udp_in6)); 231 udp_in6.sin6_len = sizeof(udp_in6); 232 udp_in6.sin6_family = AF_INET6; 233 in6_sin_2_v4mapsin6(udp_in, &udp_in6); 234 append_sa = (struct sockaddr *)&udp_in6; 235 } else 236 #endif 237 append_sa = (struct sockaddr *)udp_in; 238 m_adj(n, off); 239 240 so = inp->inp_socket; 241 SOCKBUF_LOCK(&so->so_rcv); 242 if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) { 243 SOCKBUF_UNLOCK(&so->so_rcv); 244 m_freem(n); 245 if (opts) 246 m_freem(opts); 247 udpstat.udps_fullsock++; 248 } else 249 sorwakeup_locked(so); 250 } 251 252 void 253 udp_input(struct mbuf *m, int off) 254 { 255 int iphlen = off; 256 struct ip *ip; 257 struct udphdr *uh; 258 struct ifnet *ifp; 259 struct inpcb *inp; 260 int len; 261 struct ip save_ip; 262 struct sockaddr_in udp_in; 263 #ifdef IPFIREWALL_FORWARD 264 struct m_tag *fwd_tag; 265 #endif 266 267 ifp = m->m_pkthdr.rcvif; 268 udpstat.udps_ipackets++; 269 270 /* 271 * Strip IP options, if any; should skip this, make available to 272 * user, and use on returned packets, but we don't yet have a way to 273 * check the checksum with options still present. 274 */ 275 if (iphlen > sizeof (struct ip)) { 276 ip_stripoptions(m, (struct mbuf *)0); 277 iphlen = sizeof(struct ip); 278 } 279 280 /* 281 * Get IP and UDP header together in first mbuf. 282 */ 283 ip = mtod(m, struct ip *); 284 if (m->m_len < iphlen + sizeof(struct udphdr)) { 285 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 286 udpstat.udps_hdrops++; 287 return; 288 } 289 ip = mtod(m, struct ip *); 290 } 291 uh = (struct udphdr *)((caddr_t)ip + iphlen); 292 293 /* 294 * Destination port of 0 is illegal, based on RFC768. 295 */ 296 if (uh->uh_dport == 0) 297 goto badunlocked; 298 299 /* 300 * Construct sockaddr format source address. Stuff source address 301 * and datagram in user buffer. 302 */ 303 bzero(&udp_in, sizeof(udp_in)); 304 udp_in.sin_len = sizeof(udp_in); 305 udp_in.sin_family = AF_INET; 306 udp_in.sin_port = uh->uh_sport; 307 udp_in.sin_addr = ip->ip_src; 308 309 /* 310 * Make mbuf data length reflect UDP length. If not enough data to 311 * reflect UDP length, drop. 312 */ 313 len = ntohs((u_short)uh->uh_ulen); 314 if (ip->ip_len != len) { 315 if (len > ip->ip_len || len < sizeof(struct udphdr)) { 316 udpstat.udps_badlen++; 317 goto badunlocked; 318 } 319 m_adj(m, len - ip->ip_len); 320 /* ip->ip_len = len; */ 321 } 322 323 /* 324 * Save a copy of the IP header in case we want restore it for 325 * sending an ICMP error message in response. 326 */ 327 if (!udp_blackhole) 328 save_ip = *ip; 329 else 330 memset(&save_ip, 0, sizeof(save_ip)); 331 332 /* 333 * Checksum extended UDP header and data. 334 */ 335 if (uh->uh_sum) { 336 u_short uh_sum; 337 338 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) { 339 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) 340 uh_sum = m->m_pkthdr.csum_data; 341 else 342 uh_sum = in_pseudo(ip->ip_src.s_addr, 343 ip->ip_dst.s_addr, htonl((u_short)len + 344 m->m_pkthdr.csum_data + IPPROTO_UDP)); 345 uh_sum ^= 0xffff; 346 } else { 347 char b[9]; 348 349 bcopy(((struct ipovly *)ip)->ih_x1, b, 9); 350 bzero(((struct ipovly *)ip)->ih_x1, 9); 351 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 352 uh_sum = in_cksum(m, len + sizeof (struct ip)); 353 bcopy(b, ((struct ipovly *)ip)->ih_x1, 9); 354 } 355 if (uh_sum) { 356 udpstat.udps_badsum++; 357 m_freem(m); 358 return; 359 } 360 } else 361 udpstat.udps_nosum++; 362 363 #ifdef IPFIREWALL_FORWARD 364 /* 365 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain. 366 */ 367 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); 368 if (fwd_tag != NULL) { 369 struct sockaddr_in *next_hop; 370 371 /* 372 * Do the hack. 373 */ 374 next_hop = (struct sockaddr_in *)(fwd_tag + 1); 375 ip->ip_dst = next_hop->sin_addr; 376 uh->uh_dport = ntohs(next_hop->sin_port); 377 378 /* 379 * Remove the tag from the packet. We don't need it anymore. 380 */ 381 m_tag_delete(m, fwd_tag); 382 } 383 #endif 384 385 INP_INFO_RLOCK(&udbinfo); 386 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 387 in_broadcast(ip->ip_dst, ifp)) { 388 struct inpcb *last; 389 struct ip_moptions *imo; 390 391 last = NULL; 392 LIST_FOREACH(inp, &udb, inp_list) { 393 if (inp->inp_lport != uh->uh_dport) 394 continue; 395 #ifdef INET6 396 if ((inp->inp_vflag & INP_IPV4) == 0) 397 continue; 398 #endif 399 if (inp->inp_laddr.s_addr != INADDR_ANY && 400 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) 401 continue; 402 if (inp->inp_faddr.s_addr != INADDR_ANY && 403 inp->inp_faddr.s_addr != ip->ip_src.s_addr) 404 continue; 405 /* 406 * XXX: Do not check source port of incoming datagram 407 * unless inp_connect() has been called to bind the 408 * fport part of the 4-tuple; the source could be 409 * trying to talk to us with an ephemeral port. 410 */ 411 if (inp->inp_fport != 0 && 412 inp->inp_fport != uh->uh_sport) 413 continue; 414 415 INP_LOCK(inp); 416 417 /* 418 * Handle socket delivery policy for any-source 419 * and source-specific multicast. [RFC3678] 420 */ 421 imo = inp->inp_moptions; 422 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 423 imo != NULL) { 424 struct sockaddr_in sin; 425 struct in_msource *ims; 426 int blocked, mode; 427 size_t idx; 428 429 bzero(&sin, sizeof(struct sockaddr_in)); 430 sin.sin_len = sizeof(struct sockaddr_in); 431 sin.sin_family = AF_INET; 432 sin.sin_addr = ip->ip_dst; 433 434 blocked = 0; 435 idx = imo_match_group(imo, ifp, 436 (struct sockaddr *)&sin); 437 if (idx == -1) { 438 /* 439 * No group membership for this socket. 440 * Do not bump udps_noportbcast, as 441 * this will happen further down. 442 */ 443 blocked++; 444 } else { 445 /* 446 * Check for a multicast source filter 447 * entry on this socket for this group. 448 * MCAST_EXCLUDE is the default 449 * behaviour. It means default accept; 450 * entries, if present, denote sources 451 * to be excluded from delivery. 452 */ 453 ims = imo_match_source(imo, idx, 454 (struct sockaddr *)&udp_in); 455 mode = imo->imo_mfilters[idx].imf_fmode; 456 if ((ims != NULL && 457 mode == MCAST_EXCLUDE) || 458 (ims == NULL && 459 mode == MCAST_INCLUDE)) { 460 #ifdef DIAGNOSTIC 461 if (bootverbose) { 462 printf("%s: blocked by" 463 " source filter\n", 464 __func__); 465 } 466 #endif 467 udpstat.udps_filtermcast++; 468 blocked++; 469 } 470 } 471 if (blocked != 0) { 472 INP_UNLOCK(inp); 473 continue; 474 } 475 } 476 if (last != NULL) { 477 struct mbuf *n; 478 479 n = m_copy(m, 0, M_COPYALL); 480 if (n != NULL) 481 udp_append(last, ip, n, iphlen + 482 sizeof(struct udphdr), &udp_in); 483 INP_UNLOCK(last); 484 } 485 last = inp; 486 /* 487 * Don't look for additional matches if this one does 488 * not have either the SO_REUSEPORT or SO_REUSEADDR 489 * socket options set. This heuristic avoids 490 * searching through all pcbs in the common case of a 491 * non-shared port. It assumes that an application 492 * will never clear these options after setting them. 493 */ 494 if ((last->inp_socket->so_options & 495 (SO_REUSEPORT|SO_REUSEADDR)) == 0) 496 break; 497 } 498 499 if (last == NULL) { 500 /* 501 * No matching pcb found; discard datagram. (No need 502 * to send an ICMP Port Unreachable for a broadcast 503 * or multicast datgram.) 504 */ 505 udpstat.udps_noportbcast++; 506 goto badheadlocked; 507 } 508 udp_append(last, ip, m, iphlen + sizeof(struct udphdr), 509 &udp_in); 510 INP_UNLOCK(last); 511 INP_INFO_RUNLOCK(&udbinfo); 512 return; 513 } 514 515 /* 516 * Locate pcb for datagram. 517 */ 518 inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport, 519 ip->ip_dst, uh->uh_dport, 1, ifp); 520 if (inp == NULL) { 521 if (udp_log_in_vain) { 522 char buf[4*sizeof "123"]; 523 524 strcpy(buf, inet_ntoa(ip->ip_dst)); 525 log(LOG_INFO, 526 "Connection attempt to UDP %s:%d from %s:%d\n", 527 buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src), 528 ntohs(uh->uh_sport)); 529 } 530 udpstat.udps_noport++; 531 if (m->m_flags & (M_BCAST | M_MCAST)) { 532 udpstat.udps_noportbcast++; 533 goto badheadlocked; 534 } 535 if (udp_blackhole) 536 goto badheadlocked; 537 if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0) 538 goto badheadlocked; 539 *ip = save_ip; 540 ip->ip_len += iphlen; 541 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); 542 INP_INFO_RUNLOCK(&udbinfo); 543 return; 544 } 545 546 /* 547 * Check the minimum TTL for socket. 548 */ 549 INP_LOCK(inp); 550 if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) 551 goto badheadlocked; 552 udp_append(inp, ip, m, iphlen + sizeof(struct udphdr), &udp_in); 553 INP_UNLOCK(inp); 554 INP_INFO_RUNLOCK(&udbinfo); 555 return; 556 557 badheadlocked: 558 if (inp) 559 INP_UNLOCK(inp); 560 INP_INFO_RUNLOCK(&udbinfo); 561 badunlocked: 562 m_freem(m); 563 } 564 565 /* 566 * Notify a udp user of an asynchronous error; just wake up so that they can 567 * collect error status. 568 */ 569 struct inpcb * 570 udp_notify(struct inpcb *inp, int errno) 571 { 572 573 inp->inp_socket->so_error = errno; 574 sorwakeup(inp->inp_socket); 575 sowwakeup(inp->inp_socket); 576 return (inp); 577 } 578 579 void 580 udp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 581 { 582 struct ip *ip = vip; 583 struct udphdr *uh; 584 struct in_addr faddr; 585 struct inpcb *inp; 586 587 faddr = ((struct sockaddr_in *)sa)->sin_addr; 588 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 589 return; 590 591 /* 592 * Redirects don't need to be handled up here. 593 */ 594 if (PRC_IS_REDIRECT(cmd)) 595 return; 596 597 /* 598 * Hostdead is ugly because it goes linearly through all PCBs. 599 * 600 * XXX: We never get this from ICMP, otherwise it makes an excellent 601 * DoS attack on machines with many connections. 602 */ 603 if (cmd == PRC_HOSTDEAD) 604 ip = NULL; 605 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 606 return; 607 if (ip != NULL) { 608 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 609 INP_INFO_RLOCK(&udbinfo); 610 inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport, 611 ip->ip_src, uh->uh_sport, 0, NULL); 612 if (inp != NULL) { 613 INP_LOCK(inp); 614 if (inp->inp_socket != NULL) { 615 udp_notify(inp, inetctlerrmap[cmd]); 616 } 617 INP_UNLOCK(inp); 618 } 619 INP_INFO_RUNLOCK(&udbinfo); 620 } else 621 in_pcbnotifyall(&udbinfo, faddr, inetctlerrmap[cmd], 622 udp_notify); 623 } 624 625 static int 626 udp_pcblist(SYSCTL_HANDLER_ARGS) 627 { 628 int error, i, n; 629 struct inpcb *inp, **inp_list; 630 inp_gen_t gencnt; 631 struct xinpgen xig; 632 633 /* 634 * The process of preparing the PCB list is too time-consuming and 635 * resource-intensive to repeat twice on every request. 636 */ 637 if (req->oldptr == 0) { 638 n = udbinfo.ipi_count; 639 req->oldidx = 2 * (sizeof xig) 640 + (n + n/8) * sizeof(struct xinpcb); 641 return (0); 642 } 643 644 if (req->newptr != 0) 645 return (EPERM); 646 647 /* 648 * OK, now we're committed to doing something. 649 */ 650 INP_INFO_RLOCK(&udbinfo); 651 gencnt = udbinfo.ipi_gencnt; 652 n = udbinfo.ipi_count; 653 INP_INFO_RUNLOCK(&udbinfo); 654 655 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 656 + n * sizeof(struct xinpcb)); 657 if (error != 0) 658 return (error); 659 660 xig.xig_len = sizeof xig; 661 xig.xig_count = n; 662 xig.xig_gen = gencnt; 663 xig.xig_sogen = so_gencnt; 664 error = SYSCTL_OUT(req, &xig, sizeof xig); 665 if (error) 666 return (error); 667 668 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 669 if (inp_list == 0) 670 return (ENOMEM); 671 672 INP_INFO_RLOCK(&udbinfo); 673 for (inp = LIST_FIRST(udbinfo.ipi_listhead), i = 0; inp && i < n; 674 inp = LIST_NEXT(inp, inp_list)) { 675 INP_LOCK(inp); 676 if (inp->inp_gencnt <= gencnt && 677 cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0) 678 inp_list[i++] = inp; 679 INP_UNLOCK(inp); 680 } 681 INP_INFO_RUNLOCK(&udbinfo); 682 n = i; 683 684 error = 0; 685 for (i = 0; i < n; i++) { 686 inp = inp_list[i]; 687 INP_LOCK(inp); 688 if (inp->inp_gencnt <= gencnt) { 689 struct xinpcb xi; 690 bzero(&xi, sizeof(xi)); 691 xi.xi_len = sizeof xi; 692 /* XXX should avoid extra copy */ 693 bcopy(inp, &xi.xi_inp, sizeof *inp); 694 if (inp->inp_socket) 695 sotoxsocket(inp->inp_socket, &xi.xi_socket); 696 xi.xi_inp.inp_gencnt = inp->inp_gencnt; 697 INP_UNLOCK(inp); 698 error = SYSCTL_OUT(req, &xi, sizeof xi); 699 } else 700 INP_UNLOCK(inp); 701 } 702 if (!error) { 703 /* 704 * Give the user an updated idea of our state. If the 705 * generation differs from what we told her before, she knows 706 * that something happened while we were processing this 707 * request, and it might be necessary to retry. 708 */ 709 INP_INFO_RLOCK(&udbinfo); 710 xig.xig_gen = udbinfo.ipi_gencnt; 711 xig.xig_sogen = so_gencnt; 712 xig.xig_count = udbinfo.ipi_count; 713 INP_INFO_RUNLOCK(&udbinfo); 714 error = SYSCTL_OUT(req, &xig, sizeof xig); 715 } 716 free(inp_list, M_TEMP); 717 return (error); 718 } 719 720 SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 721 udp_pcblist, "S,xinpcb", "List of active UDP sockets"); 722 723 static int 724 udp_getcred(SYSCTL_HANDLER_ARGS) 725 { 726 struct xucred xuc; 727 struct sockaddr_in addrs[2]; 728 struct inpcb *inp; 729 int error; 730 731 error = priv_check(req->td, PRIV_NETINET_GETCRED); 732 if (error) 733 return (error); 734 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 735 if (error) 736 return (error); 737 INP_INFO_RLOCK(&udbinfo); 738 inp = in_pcblookup_hash(&udbinfo, addrs[1].sin_addr, addrs[1].sin_port, 739 addrs[0].sin_addr, addrs[0].sin_port, 1, NULL); 740 if (inp == NULL || inp->inp_socket == NULL) { 741 error = ENOENT; 742 goto out; 743 } 744 error = cr_canseesocket(req->td->td_ucred, inp->inp_socket); 745 if (error) 746 goto out; 747 cru2x(inp->inp_socket->so_cred, &xuc); 748 out: 749 INP_INFO_RUNLOCK(&udbinfo); 750 if (error == 0) 751 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 752 return (error); 753 } 754 755 SYSCTL_PROC(_net_inet_udp, OID_AUTO, getcred, 756 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 757 udp_getcred, "S,xucred", "Get the xucred of a UDP connection"); 758 759 static int 760 udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr, 761 struct mbuf *control, struct thread *td) 762 { 763 struct udpiphdr *ui; 764 int len = m->m_pkthdr.len; 765 struct in_addr faddr, laddr; 766 struct cmsghdr *cm; 767 struct sockaddr_in *sin, src; 768 int error = 0; 769 int ipflags; 770 u_short fport, lport; 771 int unlock_udbinfo; 772 773 /* 774 * udp_output() may need to temporarily bind or connect the current 775 * inpcb. As such, we don't know up front whether we will need the 776 * pcbinfo lock or not. Do any work to decide what is needed up 777 * front before acquiring any locks. 778 */ 779 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) { 780 if (control) 781 m_freem(control); 782 m_freem(m); 783 return (EMSGSIZE); 784 } 785 786 src.sin_family = 0; 787 if (control != NULL) { 788 /* 789 * XXX: Currently, we assume all the optional information is 790 * stored in a single mbuf. 791 */ 792 if (control->m_next) { 793 m_freem(control); 794 m_freem(m); 795 return (EINVAL); 796 } 797 for (; control->m_len > 0; 798 control->m_data += CMSG_ALIGN(cm->cmsg_len), 799 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) { 800 cm = mtod(control, struct cmsghdr *); 801 if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0 802 || cm->cmsg_len > control->m_len) { 803 error = EINVAL; 804 break; 805 } 806 if (cm->cmsg_level != IPPROTO_IP) 807 continue; 808 809 switch (cm->cmsg_type) { 810 case IP_SENDSRCADDR: 811 if (cm->cmsg_len != 812 CMSG_LEN(sizeof(struct in_addr))) { 813 error = EINVAL; 814 break; 815 } 816 bzero(&src, sizeof(src)); 817 src.sin_family = AF_INET; 818 src.sin_len = sizeof(src); 819 src.sin_port = inp->inp_lport; 820 src.sin_addr = 821 *(struct in_addr *)CMSG_DATA(cm); 822 break; 823 824 default: 825 error = ENOPROTOOPT; 826 break; 827 } 828 if (error) 829 break; 830 } 831 m_freem(control); 832 } 833 if (error) { 834 m_freem(m); 835 return (error); 836 } 837 838 if (src.sin_family == AF_INET || addr != NULL) { 839 INP_INFO_WLOCK(&udbinfo); 840 unlock_udbinfo = 1; 841 } else 842 unlock_udbinfo = 0; 843 INP_LOCK(inp); 844 845 #ifdef MAC 846 mac_create_mbuf_from_inpcb(inp, m); 847 #endif 848 849 /* 850 * If the IP_SENDSRCADDR control message was specified, override the 851 * source address for this datagram. Its use is invalidated if the 852 * address thus specified is incomplete or clobbers other inpcbs. 853 */ 854 laddr = inp->inp_laddr; 855 lport = inp->inp_lport; 856 if (src.sin_family == AF_INET) { 857 if ((lport == 0) || 858 (laddr.s_addr == INADDR_ANY && 859 src.sin_addr.s_addr == INADDR_ANY)) { 860 error = EINVAL; 861 goto release; 862 } 863 error = in_pcbbind_setup(inp, (struct sockaddr *)&src, 864 &laddr.s_addr, &lport, td->td_ucred); 865 if (error) 866 goto release; 867 } 868 869 if (addr) { 870 sin = (struct sockaddr_in *)addr; 871 if (jailed(td->td_ucred)) 872 prison_remote_ip(td->td_ucred, 0, 873 &sin->sin_addr.s_addr); 874 if (inp->inp_faddr.s_addr != INADDR_ANY) { 875 error = EISCONN; 876 goto release; 877 } 878 error = in_pcbconnect_setup(inp, addr, &laddr.s_addr, &lport, 879 &faddr.s_addr, &fport, NULL, td->td_ucred); 880 if (error) 881 goto release; 882 883 /* Commit the local port if newly assigned. */ 884 if (inp->inp_laddr.s_addr == INADDR_ANY && 885 inp->inp_lport == 0) { 886 /* 887 * Remember addr if jailed, to prevent rebinding. 888 */ 889 if (jailed(td->td_ucred)) 890 inp->inp_laddr = laddr; 891 inp->inp_lport = lport; 892 if (in_pcbinshash(inp) != 0) { 893 inp->inp_lport = 0; 894 error = EAGAIN; 895 goto release; 896 } 897 inp->inp_flags |= INP_ANONPORT; 898 } 899 } else { 900 faddr = inp->inp_faddr; 901 fport = inp->inp_fport; 902 if (faddr.s_addr == INADDR_ANY) { 903 error = ENOTCONN; 904 goto release; 905 } 906 } 907 908 /* 909 * Calculate data length and get a mbuf for UDP, IP, and possible 910 * link-layer headers. Immediate slide the data pointer back forward 911 * since we won't use that space at this layer. 912 */ 913 M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_DONTWAIT); 914 if (m == NULL) { 915 error = ENOBUFS; 916 goto release; 917 } 918 m->m_data += max_linkhdr; 919 m->m_len -= max_linkhdr; 920 m->m_pkthdr.len -= max_linkhdr; 921 922 /* 923 * Fill in mbuf with extended UDP header and addresses and length put 924 * into network format. 925 */ 926 ui = mtod(m, struct udpiphdr *); 927 bzero(ui->ui_x1, sizeof(ui->ui_x1)); /* XXX still needed? */ 928 ui->ui_pr = IPPROTO_UDP; 929 ui->ui_src = laddr; 930 ui->ui_dst = faddr; 931 ui->ui_sport = lport; 932 ui->ui_dport = fport; 933 ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr)); 934 935 /* 936 * Set the Don't Fragment bit in the IP header. 937 */ 938 if (inp->inp_flags & INP_DONTFRAG) { 939 struct ip *ip; 940 941 ip = (struct ip *)&ui->ui_i; 942 ip->ip_off |= IP_DF; 943 } 944 945 ipflags = 0; 946 if (inp->inp_socket->so_options & SO_DONTROUTE) 947 ipflags |= IP_ROUTETOIF; 948 if (inp->inp_socket->so_options & SO_BROADCAST) 949 ipflags |= IP_ALLOWBROADCAST; 950 if (inp->inp_flags & INP_ONESBCAST) 951 ipflags |= IP_SENDONES; 952 953 /* 954 * Set up checksum and output datagram. 955 */ 956 if (udp_cksum) { 957 if (inp->inp_flags & INP_ONESBCAST) 958 faddr.s_addr = INADDR_BROADCAST; 959 ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr, 960 htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP)); 961 m->m_pkthdr.csum_flags = CSUM_UDP; 962 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 963 } else 964 ui->ui_sum = 0; 965 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 966 ((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */ 967 ((struct ip *)ui)->ip_tos = inp->inp_ip_tos; /* XXX */ 968 udpstat.udps_opackets++; 969 970 if (unlock_udbinfo) 971 INP_INFO_WUNLOCK(&udbinfo); 972 error = ip_output(m, inp->inp_options, NULL, ipflags, 973 inp->inp_moptions, inp); 974 INP_UNLOCK(inp); 975 return (error); 976 977 release: 978 INP_UNLOCK(inp); 979 if (unlock_udbinfo) 980 INP_INFO_WUNLOCK(&udbinfo); 981 m_freem(m); 982 return (error); 983 } 984 985 static void 986 udp_abort(struct socket *so) 987 { 988 struct inpcb *inp; 989 990 inp = sotoinpcb(so); 991 KASSERT(inp != NULL, ("udp_abort: inp == NULL")); 992 INP_INFO_WLOCK(&udbinfo); 993 INP_LOCK(inp); 994 if (inp->inp_faddr.s_addr != INADDR_ANY) { 995 in_pcbdisconnect(inp); 996 inp->inp_laddr.s_addr = INADDR_ANY; 997 soisdisconnected(so); 998 } 999 INP_UNLOCK(inp); 1000 INP_INFO_WUNLOCK(&udbinfo); 1001 } 1002 1003 static int 1004 udp_attach(struct socket *so, int proto, struct thread *td) 1005 { 1006 struct inpcb *inp; 1007 int error; 1008 1009 inp = sotoinpcb(so); 1010 KASSERT(inp == NULL, ("udp_attach: inp != NULL")); 1011 error = soreserve(so, udp_sendspace, udp_recvspace); 1012 if (error) 1013 return (error); 1014 INP_INFO_WLOCK(&udbinfo); 1015 error = in_pcballoc(so, &udbinfo); 1016 if (error) { 1017 INP_INFO_WUNLOCK(&udbinfo); 1018 return (error); 1019 } 1020 1021 inp = (struct inpcb *)so->so_pcb; 1022 INP_INFO_WUNLOCK(&udbinfo); 1023 inp->inp_vflag |= INP_IPV4; 1024 inp->inp_ip_ttl = ip_defttl; 1025 INP_UNLOCK(inp); 1026 return (0); 1027 } 1028 1029 static int 1030 udp_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 1031 { 1032 struct inpcb *inp; 1033 int error; 1034 1035 inp = sotoinpcb(so); 1036 KASSERT(inp != NULL, ("udp_bind: inp == NULL")); 1037 INP_INFO_WLOCK(&udbinfo); 1038 INP_LOCK(inp); 1039 error = in_pcbbind(inp, nam, td->td_ucred); 1040 INP_UNLOCK(inp); 1041 INP_INFO_WUNLOCK(&udbinfo); 1042 return (error); 1043 } 1044 1045 static void 1046 udp_close(struct socket *so) 1047 { 1048 struct inpcb *inp; 1049 1050 inp = sotoinpcb(so); 1051 KASSERT(inp != NULL, ("udp_close: inp == NULL")); 1052 INP_INFO_WLOCK(&udbinfo); 1053 INP_LOCK(inp); 1054 if (inp->inp_faddr.s_addr != INADDR_ANY) { 1055 in_pcbdisconnect(inp); 1056 inp->inp_laddr.s_addr = INADDR_ANY; 1057 soisdisconnected(so); 1058 } 1059 INP_UNLOCK(inp); 1060 INP_INFO_WUNLOCK(&udbinfo); 1061 } 1062 1063 static int 1064 udp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1065 { 1066 struct inpcb *inp; 1067 int error; 1068 struct sockaddr_in *sin; 1069 1070 inp = sotoinpcb(so); 1071 KASSERT(inp != NULL, ("udp_connect: inp == NULL")); 1072 INP_INFO_WLOCK(&udbinfo); 1073 INP_LOCK(inp); 1074 if (inp->inp_faddr.s_addr != INADDR_ANY) { 1075 INP_UNLOCK(inp); 1076 INP_INFO_WUNLOCK(&udbinfo); 1077 return (EISCONN); 1078 } 1079 sin = (struct sockaddr_in *)nam; 1080 if (jailed(td->td_ucred)) 1081 prison_remote_ip(td->td_ucred, 0, &sin->sin_addr.s_addr); 1082 error = in_pcbconnect(inp, nam, td->td_ucred); 1083 if (error == 0) 1084 soisconnected(so); 1085 INP_UNLOCK(inp); 1086 INP_INFO_WUNLOCK(&udbinfo); 1087 return (error); 1088 } 1089 1090 static void 1091 udp_detach(struct socket *so) 1092 { 1093 struct inpcb *inp; 1094 1095 inp = sotoinpcb(so); 1096 KASSERT(inp != NULL, ("udp_detach: inp == NULL")); 1097 KASSERT(inp->inp_faddr.s_addr == INADDR_ANY, 1098 ("udp_detach: not disconnected")); 1099 INP_INFO_WLOCK(&udbinfo); 1100 INP_LOCK(inp); 1101 in_pcbdetach(inp); 1102 in_pcbfree(inp); 1103 INP_INFO_WUNLOCK(&udbinfo); 1104 } 1105 1106 static int 1107 udp_disconnect(struct socket *so) 1108 { 1109 struct inpcb *inp; 1110 1111 inp = sotoinpcb(so); 1112 KASSERT(inp != NULL, ("udp_disconnect: inp == NULL")); 1113 INP_INFO_WLOCK(&udbinfo); 1114 INP_LOCK(inp); 1115 if (inp->inp_faddr.s_addr == INADDR_ANY) { 1116 INP_INFO_WUNLOCK(&udbinfo); 1117 INP_UNLOCK(inp); 1118 return (ENOTCONN); 1119 } 1120 1121 in_pcbdisconnect(inp); 1122 inp->inp_laddr.s_addr = INADDR_ANY; 1123 SOCK_LOCK(so); 1124 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 1125 SOCK_UNLOCK(so); 1126 INP_UNLOCK(inp); 1127 INP_INFO_WUNLOCK(&udbinfo); 1128 return (0); 1129 } 1130 1131 static int 1132 udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr, 1133 struct mbuf *control, struct thread *td) 1134 { 1135 struct inpcb *inp; 1136 1137 inp = sotoinpcb(so); 1138 KASSERT(inp != NULL, ("udp_send: inp == NULL")); 1139 return (udp_output(inp, m, addr, control, td)); 1140 } 1141 1142 int 1143 udp_shutdown(struct socket *so) 1144 { 1145 struct inpcb *inp; 1146 1147 inp = sotoinpcb(so); 1148 KASSERT(inp != NULL, ("udp_shutdown: inp == NULL")); 1149 INP_LOCK(inp); 1150 socantsendmore(so); 1151 INP_UNLOCK(inp); 1152 return (0); 1153 } 1154 1155 struct pr_usrreqs udp_usrreqs = { 1156 .pru_abort = udp_abort, 1157 .pru_attach = udp_attach, 1158 .pru_bind = udp_bind, 1159 .pru_connect = udp_connect, 1160 .pru_control = in_control, 1161 .pru_detach = udp_detach, 1162 .pru_disconnect = udp_disconnect, 1163 .pru_peeraddr = in_getpeeraddr, 1164 .pru_send = udp_send, 1165 .pru_sosend = sosend_dgram, 1166 .pru_shutdown = udp_shutdown, 1167 .pru_sockaddr = in_getsockaddr, 1168 .pru_sosetlabel = in_pcbsosetlabel, 1169 .pru_close = udp_close, 1170 };
Cache object: 6b827ef231ea292034332f08b2d4b942
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