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 * $Id: udp_usrreq.c,v 1.35 1997/02/24 20:31:25 wollman Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/queue.h> 39 #include <sys/systm.h> 40 #include <sys/errno.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/protosw.h> 45 #include <sys/socket.h> 46 #include <sys/socketvar.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/syslog.h> 50 51 #include <net/if.h> 52 #include <net/route.h> 53 54 #include <netinet/in.h> 55 #include <netinet/in_systm.h> 56 #include <netinet/ip.h> 57 #include <netinet/in_pcb.h> 58 #include <netinet/in_var.h> 59 #include <netinet/ip_var.h> 60 #include <netinet/ip_icmp.h> 61 #include <netinet/udp.h> 62 #include <netinet/udp_var.h> 63 64 /* 65 * UDP protocol implementation. 66 * Per RFC 768, August, 1980. 67 */ 68 #ifndef COMPAT_42 69 static int udpcksum = 1; 70 #else 71 static int udpcksum = 0; /* XXX */ 72 #endif 73 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, 74 &udpcksum, 0, ""); 75 76 static int log_in_vain = 0; 77 SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW, 78 &log_in_vain, 0, ""); 79 80 static struct inpcbhead udb; /* from udp_var.h */ 81 static struct inpcbinfo udbinfo; 82 83 #ifndef UDBHASHSIZE 84 #define UDBHASHSIZE 64 85 #endif 86 87 static struct udpstat udpstat; /* from udp_var.h */ 88 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RD, 89 &udpstat, udpstat, ""); 90 91 static struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 92 93 static int udp_output __P((struct inpcb *, struct mbuf *, struct mbuf *, 94 struct mbuf *)); 95 static void udp_notify __P((struct inpcb *, int)); 96 97 void 98 udp_init() 99 { 100 LIST_INIT(&udb); 101 udbinfo.listhead = &udb; 102 udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask); 103 } 104 105 void 106 udp_input(m, iphlen) 107 register struct mbuf *m; 108 int iphlen; 109 { 110 register struct ip *ip; 111 register struct udphdr *uh; 112 register struct inpcb *inp; 113 struct mbuf *opts = 0; 114 int len; 115 struct ip save_ip; 116 117 udpstat.udps_ipackets++; 118 119 /* 120 * Strip IP options, if any; should skip this, 121 * make available to user, and use on returned packets, 122 * but we don't yet have a way to check the checksum 123 * with options still present. 124 */ 125 if (iphlen > sizeof (struct ip)) { 126 ip_stripoptions(m, (struct mbuf *)0); 127 iphlen = sizeof(struct ip); 128 } 129 130 /* 131 * Get IP and UDP header together in first mbuf. 132 */ 133 ip = mtod(m, struct ip *); 134 if (m->m_len < iphlen + sizeof(struct udphdr)) { 135 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 136 udpstat.udps_hdrops++; 137 return; 138 } 139 ip = mtod(m, struct ip *); 140 } 141 uh = (struct udphdr *)((caddr_t)ip + iphlen); 142 143 /* 144 * Make mbuf data length reflect UDP length. 145 * If not enough data to reflect UDP length, drop. 146 */ 147 len = ntohs((u_short)uh->uh_ulen); 148 if (ip->ip_len != len) { 149 if (len > ip->ip_len || len < sizeof(struct udphdr)) { 150 udpstat.udps_badlen++; 151 goto bad; 152 } 153 m_adj(m, len - ip->ip_len); 154 /* ip->ip_len = len; */ 155 } 156 /* 157 * Save a copy of the IP header in case we want restore it 158 * for sending an ICMP error message in response. 159 */ 160 save_ip = *ip; 161 162 /* 163 * Checksum extended UDP header and data. 164 */ 165 if (uh->uh_sum) { 166 ((struct ipovly *)ip)->ih_next = 0; 167 ((struct ipovly *)ip)->ih_prev = 0; 168 ((struct ipovly *)ip)->ih_x1 = 0; 169 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 170 uh->uh_sum = in_cksum(m, len + sizeof (struct ip)); 171 if (uh->uh_sum) { 172 udpstat.udps_badsum++; 173 m_freem(m); 174 return; 175 } 176 } 177 178 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 179 in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { 180 struct inpcb *last; 181 /* 182 * Deliver a multicast or broadcast datagram to *all* sockets 183 * for which the local and remote addresses and ports match 184 * those of the incoming datagram. This allows more than 185 * one process to receive multi/broadcasts on the same port. 186 * (This really ought to be done for unicast datagrams as 187 * well, but that would cause problems with existing 188 * applications that open both address-specific sockets and 189 * a wildcard socket listening to the same port -- they would 190 * end up receiving duplicates of every unicast datagram. 191 * Those applications open the multiple sockets to overcome an 192 * inadequacy of the UDP socket interface, but for backwards 193 * compatibility we avoid the problem here rather than 194 * fixing the interface. Maybe 4.5BSD will remedy this?) 195 */ 196 197 /* 198 * Construct sockaddr format source address. 199 */ 200 udp_in.sin_port = uh->uh_sport; 201 udp_in.sin_addr = ip->ip_src; 202 m->m_len -= sizeof (struct udpiphdr); 203 m->m_data += sizeof (struct udpiphdr); 204 /* 205 * Locate pcb(s) for datagram. 206 * (Algorithm copied from raw_intr().) 207 */ 208 last = NULL; 209 for (inp = udb.lh_first; inp != NULL; inp = inp->inp_list.le_next) { 210 if (inp->inp_lport != uh->uh_dport) 211 continue; 212 if (inp->inp_laddr.s_addr != INADDR_ANY) { 213 if (inp->inp_laddr.s_addr != 214 ip->ip_dst.s_addr) 215 continue; 216 } 217 if (inp->inp_faddr.s_addr != INADDR_ANY) { 218 if (inp->inp_faddr.s_addr != 219 ip->ip_src.s_addr || 220 inp->inp_fport != uh->uh_sport) 221 continue; 222 } 223 224 if (last != NULL) { 225 struct mbuf *n; 226 227 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 228 if (last->inp_flags & INP_CONTROLOPTS 229 || last->inp_socket->so_options & SO_TIMESTAMP) 230 ip_savecontrol(last, &opts, ip, n); 231 if (sbappendaddr(&last->inp_socket->so_rcv, 232 (struct sockaddr *)&udp_in, 233 n, opts) == 0) { 234 m_freem(n); 235 if (opts) 236 m_freem(opts); 237 udpstat.udps_fullsock++; 238 } else 239 sorwakeup(last->inp_socket); 240 opts = 0; 241 } 242 } 243 last = inp; 244 /* 245 * Don't look for additional matches if this one does 246 * not have either the SO_REUSEPORT or SO_REUSEADDR 247 * socket options set. This heuristic avoids searching 248 * through all pcbs in the common case of a non-shared 249 * port. It * assumes that an application will never 250 * clear these options after setting them. 251 */ 252 if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR) == 0)) 253 break; 254 } 255 256 if (last == NULL) { 257 /* 258 * No matching pcb found; discard datagram. 259 * (No need to send an ICMP Port Unreachable 260 * for a broadcast or multicast datgram.) 261 */ 262 udpstat.udps_noportbcast++; 263 goto bad; 264 } 265 if (last->inp_flags & INP_CONTROLOPTS 266 || last->inp_socket->so_options & SO_TIMESTAMP) 267 ip_savecontrol(last, &opts, ip, m); 268 if (sbappendaddr(&last->inp_socket->so_rcv, 269 (struct sockaddr *)&udp_in, 270 m, opts) == 0) { 271 udpstat.udps_fullsock++; 272 goto bad; 273 } 274 sorwakeup(last->inp_socket); 275 return; 276 } 277 /* 278 * Locate pcb for datagram. 279 */ 280 inp = in_pcblookuphash(&udbinfo, ip->ip_src, uh->uh_sport, 281 ip->ip_dst, uh->uh_dport, 1); 282 if (inp == NULL) { 283 if (log_in_vain) { 284 char buf[4*sizeof "123"]; 285 286 strcpy(buf, inet_ntoa(ip->ip_dst)); 287 log(LOG_INFO, "Connection attempt to UDP %s:%d" 288 " from %s:%d\n", 289 buf, ntohs(uh->uh_dport), 290 inet_ntoa(ip->ip_src), ntohs(uh->uh_sport)); 291 } 292 udpstat.udps_noport++; 293 if (m->m_flags & (M_BCAST | M_MCAST)) { 294 udpstat.udps_noportbcast++; 295 goto bad; 296 } 297 *ip = save_ip; 298 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); 299 return; 300 } 301 302 /* 303 * Construct sockaddr format source address. 304 * Stuff source address and datagram in user buffer. 305 */ 306 udp_in.sin_port = uh->uh_sport; 307 udp_in.sin_addr = ip->ip_src; 308 if (inp->inp_flags & INP_CONTROLOPTS 309 || inp->inp_socket->so_options & SO_TIMESTAMP) 310 ip_savecontrol(inp, &opts, ip, m); 311 iphlen += sizeof(struct udphdr); 312 m->m_len -= iphlen; 313 m->m_pkthdr.len -= iphlen; 314 m->m_data += iphlen; 315 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 316 m, opts) == 0) { 317 udpstat.udps_fullsock++; 318 goto bad; 319 } 320 sorwakeup(inp->inp_socket); 321 return; 322 bad: 323 m_freem(m); 324 if (opts) 325 m_freem(opts); 326 } 327 328 /* 329 * Notify a udp user of an asynchronous error; 330 * just wake up so that he can collect error status. 331 */ 332 static void 333 udp_notify(inp, errno) 334 register struct inpcb *inp; 335 int errno; 336 { 337 inp->inp_socket->so_error = errno; 338 sorwakeup(inp->inp_socket); 339 sowwakeup(inp->inp_socket); 340 } 341 342 void 343 udp_ctlinput(cmd, sa, vip) 344 int cmd; 345 struct sockaddr *sa; 346 void *vip; 347 { 348 register struct ip *ip = vip; 349 register struct udphdr *uh; 350 351 if (!PRC_IS_REDIRECT(cmd) && 352 ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)) 353 return; 354 if (ip) { 355 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 356 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 357 cmd, udp_notify); 358 } else 359 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 360 } 361 362 static int 363 udp_output(inp, m, addr, control) 364 register struct inpcb *inp; 365 register struct mbuf *m; 366 struct mbuf *addr, *control; 367 { 368 register struct udpiphdr *ui; 369 register int len = m->m_pkthdr.len; 370 struct in_addr laddr; 371 int s = 0, error = 0; 372 373 if (control) 374 m_freem(control); /* XXX */ 375 376 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) { 377 error = EMSGSIZE; 378 goto release; 379 } 380 381 if (addr) { 382 laddr = inp->inp_laddr; 383 if (inp->inp_faddr.s_addr != INADDR_ANY) { 384 error = EISCONN; 385 goto release; 386 } 387 /* 388 * Must block input while temporarily connected. 389 */ 390 s = splnet(); 391 error = in_pcbconnect(inp, addr); 392 if (error) { 393 splx(s); 394 goto release; 395 } 396 } else { 397 if (inp->inp_faddr.s_addr == INADDR_ANY) { 398 error = ENOTCONN; 399 goto release; 400 } 401 } 402 /* 403 * Calculate data length and get a mbuf 404 * for UDP and IP headers. 405 */ 406 M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT); 407 if (m == 0) { 408 error = ENOBUFS; 409 if (addr) 410 splx(s); 411 goto release; 412 } 413 414 /* 415 * Fill in mbuf with extended UDP header 416 * and addresses and length put into network format. 417 */ 418 ui = mtod(m, struct udpiphdr *); 419 ui->ui_next = ui->ui_prev = 0; 420 ui->ui_x1 = 0; 421 ui->ui_pr = IPPROTO_UDP; 422 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 423 ui->ui_src = inp->inp_laddr; 424 ui->ui_dst = inp->inp_faddr; 425 ui->ui_sport = inp->inp_lport; 426 ui->ui_dport = inp->inp_fport; 427 ui->ui_ulen = ui->ui_len; 428 429 /* 430 * Stuff checksum and output datagram. 431 */ 432 ui->ui_sum = 0; 433 if (udpcksum) { 434 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 435 ui->ui_sum = 0xffff; 436 } 437 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 438 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 439 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 440 udpstat.udps_opackets++; 441 error = ip_output(m, inp->inp_options, &inp->inp_route, 442 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST), 443 inp->inp_moptions); 444 445 if (addr) { 446 in_pcbdisconnect(inp); 447 inp->inp_laddr = laddr; 448 splx(s); 449 } 450 return (error); 451 452 release: 453 m_freem(m); 454 return (error); 455 } 456 457 static u_long udp_sendspace = 9216; /* really max datagram size */ 458 /* 40 1K datagrams */ 459 SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW, 460 &udp_sendspace, 0, ""); 461 462 static u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 463 SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW, 464 &udp_recvspace, 0, ""); 465 466 static int 467 udp_abort(struct socket *so) 468 { 469 struct inpcb *inp; 470 int s; 471 472 inp = sotoinpcb(so); 473 if (inp == 0) 474 return EINVAL; /* ??? possible? panic instead? */ 475 soisdisconnected(so); 476 s = splnet(); 477 in_pcbdetach(inp); 478 splx(s); 479 return 0; 480 } 481 482 static int 483 udp_attach(struct socket *so, int proto) 484 { 485 struct inpcb *inp; 486 int s, error; 487 488 inp = sotoinpcb(so); 489 if (inp != 0) 490 return EINVAL; 491 492 s = splnet(); 493 error = in_pcballoc(so, &udbinfo); 494 splx(s); 495 if (error) 496 return error; 497 error = soreserve(so, udp_sendspace, udp_recvspace); 498 if (error) 499 return error; 500 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = ip_defttl; 501 return 0; 502 } 503 504 static int 505 udp_bind(struct socket *so, struct mbuf *nam) 506 { 507 struct inpcb *inp; 508 int s, error; 509 510 inp = sotoinpcb(so); 511 if (inp == 0) 512 return EINVAL; 513 s = splnet(); 514 error = in_pcbbind(inp, nam); 515 splx(s); 516 return error; 517 } 518 519 static int 520 udp_connect(struct socket *so, struct mbuf *nam) 521 { 522 struct inpcb *inp; 523 int s, error; 524 525 inp = sotoinpcb(so); 526 if (inp == 0) 527 return EINVAL; 528 if (inp->inp_faddr.s_addr != INADDR_ANY) 529 return EISCONN; 530 s = splnet(); 531 error = in_pcbconnect(inp, nam); 532 splx(s); 533 if (error == 0) 534 soisconnected(so); 535 return error; 536 } 537 538 static int 539 udp_detach(struct socket *so) 540 { 541 struct inpcb *inp; 542 int s; 543 544 inp = sotoinpcb(so); 545 if (inp == 0) 546 return EINVAL; 547 s = splnet(); 548 in_pcbdetach(inp); 549 splx(s); 550 return 0; 551 } 552 553 static int 554 udp_disconnect(struct socket *so) 555 { 556 struct inpcb *inp; 557 int s; 558 559 inp = sotoinpcb(so); 560 if (inp == 0) 561 return EINVAL; 562 if (inp->inp_faddr.s_addr == INADDR_ANY) 563 return ENOTCONN; 564 565 s = splnet(); 566 in_pcbdisconnect(inp); 567 inp->inp_laddr.s_addr = INADDR_ANY; 568 splx(s); 569 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 570 return 0; 571 } 572 573 static int 574 udp_send(struct socket *so, int flags, struct mbuf *m, struct mbuf *addr, 575 struct mbuf *control) 576 { 577 struct inpcb *inp; 578 579 inp = sotoinpcb(so); 580 if (inp == 0) { 581 m_freem(m); 582 return EINVAL; 583 } 584 return udp_output(inp, m, addr, control); 585 } 586 587 static int 588 udp_shutdown(struct socket *so) 589 { 590 struct inpcb *inp; 591 592 inp = sotoinpcb(so); 593 if (inp == 0) 594 return EINVAL; 595 socantsendmore(so); 596 return 0; 597 } 598 599 struct pr_usrreqs udp_usrreqs = { 600 udp_abort, pru_accept_notsupp, udp_attach, udp_bind, udp_connect, 601 pru_connect2_notsupp, in_control, udp_detach, udp_disconnect, 602 pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp, 603 pru_rcvoob_notsupp, udp_send, pru_sense_null, udp_shutdown, 604 in_setsockaddr 605 }; 606