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 1.30 1996/10/25 17:57:53 fenner Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/queue.h> 39 #include <sys/systm.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/protosw.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/errno.h> 46 #include <sys/stat.h> 47 #include <sys/kernel.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 void udp_detach __P((struct inpcb *)); 94 static int udp_output __P((struct inpcb *, struct mbuf *, struct mbuf *, 95 struct mbuf *)); 96 static void udp_notify __P((struct inpcb *, int)); 97 98 void 99 udp_init() 100 { 101 LIST_INIT(&udb); 102 udbinfo.listhead = &udb; 103 udbinfo.hashbase = phashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashsize); 104 } 105 106 void 107 udp_input(m, iphlen) 108 register struct mbuf *m; 109 int iphlen; 110 { 111 register struct ip *ip; 112 register struct udphdr *uh; 113 register struct inpcb *inp; 114 struct mbuf *opts = 0; 115 int len; 116 struct ip save_ip; 117 118 udpstat.udps_ipackets++; 119 120 /* 121 * Strip IP options, if any; should skip this, 122 * make available to user, and use on returned packets, 123 * but we don't yet have a way to check the checksum 124 * with options still present. 125 */ 126 if (iphlen > sizeof (struct ip)) { 127 ip_stripoptions(m, (struct mbuf *)0); 128 iphlen = sizeof(struct ip); 129 } 130 131 /* 132 * Get IP and UDP header together in first mbuf. 133 */ 134 ip = mtod(m, struct ip *); 135 if (m->m_len < iphlen + sizeof(struct udphdr)) { 136 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 137 udpstat.udps_hdrops++; 138 return; 139 } 140 ip = mtod(m, struct ip *); 141 } 142 uh = (struct udphdr *)((caddr_t)ip + iphlen); 143 144 /* 145 * Make mbuf data length reflect UDP length. 146 * If not enough data to reflect UDP length, drop. 147 */ 148 len = ntohs((u_short)uh->uh_ulen); 149 if (ip->ip_len != len) { 150 if (len > ip->ip_len || len < sizeof(struct udphdr)) { 151 udpstat.udps_badlen++; 152 goto bad; 153 } 154 m_adj(m, len - ip->ip_len); 155 /* ip->ip_len = len; */ 156 } 157 /* 158 * Save a copy of the IP header in case we want restore it 159 * for sending an ICMP error message in response. 160 */ 161 save_ip = *ip; 162 163 /* 164 * Checksum extended UDP header and data. 165 */ 166 if (uh->uh_sum) { 167 ((struct ipovly *)ip)->ih_next = 0; 168 ((struct ipovly *)ip)->ih_prev = 0; 169 ((struct ipovly *)ip)->ih_x1 = 0; 170 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 171 uh->uh_sum = in_cksum(m, len + sizeof (struct ip)); 172 if (uh->uh_sum) { 173 udpstat.udps_badsum++; 174 m_freem(m); 175 return; 176 } 177 } 178 179 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 180 in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { 181 struct inpcb *last; 182 /* 183 * Deliver a multicast or broadcast datagram to *all* sockets 184 * for which the local and remote addresses and ports match 185 * those of the incoming datagram. This allows more than 186 * one process to receive multi/broadcasts on the same port. 187 * (This really ought to be done for unicast datagrams as 188 * well, but that would cause problems with existing 189 * applications that open both address-specific sockets and 190 * a wildcard socket listening to the same port -- they would 191 * end up receiving duplicates of every unicast datagram. 192 * Those applications open the multiple sockets to overcome an 193 * inadequacy of the UDP socket interface, but for backwards 194 * compatibility we avoid the problem here rather than 195 * fixing the interface. Maybe 4.5BSD will remedy this?) 196 */ 197 198 /* 199 * Construct sockaddr format source address. 200 */ 201 udp_in.sin_port = uh->uh_sport; 202 udp_in.sin_addr = ip->ip_src; 203 m->m_len -= sizeof (struct udpiphdr); 204 m->m_data += sizeof (struct udpiphdr); 205 /* 206 * Locate pcb(s) for datagram. 207 * (Algorithm copied from raw_intr().) 208 */ 209 last = NULL; 210 for (inp = udb.lh_first; inp != NULL; inp = inp->inp_list.le_next) { 211 if (inp->inp_lport != uh->uh_dport) 212 continue; 213 if (inp->inp_laddr.s_addr != INADDR_ANY) { 214 if (inp->inp_laddr.s_addr != 215 ip->ip_dst.s_addr) 216 continue; 217 } 218 if (inp->inp_faddr.s_addr != INADDR_ANY) { 219 if (inp->inp_faddr.s_addr != 220 ip->ip_src.s_addr || 221 inp->inp_fport != uh->uh_sport) 222 continue; 223 } 224 225 if (last != NULL) { 226 struct mbuf *n; 227 228 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 229 if (last->inp_flags & INP_CONTROLOPTS 230 || last->inp_socket->so_options & SO_TIMESTAMP) 231 ip_savecontrol(last, &opts, ip, n); 232 if (sbappendaddr(&last->inp_socket->so_rcv, 233 (struct sockaddr *)&udp_in, 234 n, opts) == 0) { 235 m_freem(n); 236 if (opts) 237 m_freem(opts); 238 udpstat.udps_fullsock++; 239 } else 240 sorwakeup(last->inp_socket); 241 opts = 0; 242 } 243 } 244 last = inp; 245 /* 246 * Don't look for additional matches if this one does 247 * not have either the SO_REUSEPORT or SO_REUSEADDR 248 * socket options set. This heuristic avoids searching 249 * through all pcbs in the common case of a non-shared 250 * port. It * assumes that an application will never 251 * clear these options after setting them. 252 */ 253 if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR) == 0)) 254 break; 255 } 256 257 if (last == NULL) { 258 /* 259 * No matching pcb found; discard datagram. 260 * (No need to send an ICMP Port Unreachable 261 * for a broadcast or multicast datgram.) 262 */ 263 udpstat.udps_noportbcast++; 264 goto bad; 265 } 266 if (last->inp_flags & INP_CONTROLOPTS 267 || last->inp_socket->so_options & SO_TIMESTAMP) 268 ip_savecontrol(last, &opts, ip, m); 269 if (sbappendaddr(&last->inp_socket->so_rcv, 270 (struct sockaddr *)&udp_in, 271 m, opts) == 0) { 272 udpstat.udps_fullsock++; 273 goto bad; 274 } 275 sorwakeup(last->inp_socket); 276 return; 277 } 278 /* 279 * Locate pcb for datagram. 280 */ 281 inp = in_pcblookuphash(&udbinfo, ip->ip_src, uh->uh_sport, 282 ip->ip_dst, uh->uh_dport, 1); 283 if (inp == NULL) { 284 if (log_in_vain) { 285 char buf[4*sizeof "123"]; 286 287 strcpy(buf, inet_ntoa(ip->ip_dst)); 288 log(LOG_INFO, "Connection attempt to UDP %s:%d" 289 " from %s:%d\n", 290 buf, ntohs(uh->uh_dport), 291 inet_ntoa(ip->ip_src), ntohs(uh->uh_sport)); 292 } 293 udpstat.udps_noport++; 294 if (m->m_flags & (M_BCAST | M_MCAST)) { 295 udpstat.udps_noportbcast++; 296 goto bad; 297 } 298 *ip = save_ip; 299 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); 300 return; 301 } 302 303 /* 304 * Construct sockaddr format source address. 305 * Stuff source address and datagram in user buffer. 306 */ 307 udp_in.sin_port = uh->uh_sport; 308 udp_in.sin_addr = ip->ip_src; 309 if (inp->inp_flags & INP_CONTROLOPTS 310 || inp->inp_socket->so_options & SO_TIMESTAMP) 311 ip_savecontrol(inp, &opts, ip, m); 312 iphlen += sizeof(struct udphdr); 313 m->m_len -= iphlen; 314 m->m_pkthdr.len -= iphlen; 315 m->m_data += iphlen; 316 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 317 m, opts) == 0) { 318 udpstat.udps_fullsock++; 319 goto bad; 320 } 321 sorwakeup(inp->inp_socket); 322 return; 323 bad: 324 m_freem(m); 325 if (opts) 326 m_freem(opts); 327 } 328 329 /* 330 * Notify a udp user of an asynchronous error; 331 * just wake up so that he can collect error status. 332 */ 333 static void 334 udp_notify(inp, errno) 335 register struct inpcb *inp; 336 int errno; 337 { 338 inp->inp_socket->so_error = errno; 339 sorwakeup(inp->inp_socket); 340 sowwakeup(inp->inp_socket); 341 } 342 343 void 344 udp_ctlinput(cmd, sa, vip) 345 int cmd; 346 struct sockaddr *sa; 347 void *vip; 348 { 349 register struct ip *ip = vip; 350 register struct udphdr *uh; 351 352 if (!PRC_IS_REDIRECT(cmd) && 353 ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)) 354 return; 355 if (ip) { 356 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 357 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 358 cmd, udp_notify); 359 } else 360 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 361 } 362 363 static int 364 udp_output(inp, m, addr, control) 365 register struct inpcb *inp; 366 register struct mbuf *m; 367 struct mbuf *addr, *control; 368 { 369 register struct udpiphdr *ui; 370 register int len = m->m_pkthdr.len; 371 struct in_addr laddr; 372 int s = 0, error = 0; 373 374 if (control) 375 m_freem(control); /* XXX */ 376 377 if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) { 378 error = EMSGSIZE; 379 goto release; 380 } 381 382 if (addr) { 383 laddr = inp->inp_laddr; 384 if (inp->inp_faddr.s_addr != INADDR_ANY) { 385 error = EISCONN; 386 goto release; 387 } 388 /* 389 * Must block input while temporarily connected. 390 */ 391 s = splnet(); 392 error = in_pcbconnect(inp, addr); 393 if (error) { 394 splx(s); 395 goto release; 396 } 397 } else { 398 if (inp->inp_faddr.s_addr == INADDR_ANY) { 399 error = ENOTCONN; 400 goto release; 401 } 402 } 403 /* 404 * Calculate data length and get a mbuf 405 * for UDP and IP headers. 406 */ 407 M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT); 408 if (m == 0) { 409 error = ENOBUFS; 410 if (addr) 411 splx(s); 412 goto release; 413 } 414 415 /* 416 * Fill in mbuf with extended UDP header 417 * and addresses and length put into network format. 418 */ 419 ui = mtod(m, struct udpiphdr *); 420 ui->ui_next = ui->ui_prev = 0; 421 ui->ui_x1 = 0; 422 ui->ui_pr = IPPROTO_UDP; 423 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 424 ui->ui_src = inp->inp_laddr; 425 ui->ui_dst = inp->inp_faddr; 426 ui->ui_sport = inp->inp_lport; 427 ui->ui_dport = inp->inp_fport; 428 ui->ui_ulen = ui->ui_len; 429 430 /* 431 * Stuff checksum and output datagram. 432 */ 433 ui->ui_sum = 0; 434 if (udpcksum) { 435 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 436 ui->ui_sum = 0xffff; 437 } 438 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 439 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 440 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 441 udpstat.udps_opackets++; 442 error = ip_output(m, inp->inp_options, &inp->inp_route, 443 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST), 444 inp->inp_moptions); 445 446 if (addr) { 447 in_pcbdisconnect(inp); 448 inp->inp_laddr = laddr; 449 splx(s); 450 } 451 return (error); 452 453 release: 454 m_freem(m); 455 return (error); 456 } 457 458 static u_long udp_sendspace = 9216; /* really max datagram size */ 459 /* 40 1K datagrams */ 460 SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW, 461 &udp_sendspace, 0, ""); 462 463 static u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 464 SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW, 465 &udp_recvspace, 0, ""); 466 467 /*ARGSUSED*/ 468 int 469 udp_usrreq(so, req, m, addr, control) 470 struct socket *so; 471 int req; 472 struct mbuf *m, *addr, *control; 473 { 474 struct inpcb *inp = sotoinpcb(so); 475 int error = 0; 476 int s; 477 478 if (req == PRU_CONTROL) 479 return (in_control(so, (u_long)m, (caddr_t)addr, 480 (struct ifnet *)control)); 481 if (inp == NULL && req != PRU_ATTACH) { 482 error = EINVAL; 483 goto release; 484 } 485 /* 486 * Note: need to block udp_input while changing 487 * the udp pcb queue and/or pcb addresses. 488 */ 489 switch (req) { 490 491 case PRU_ATTACH: 492 if (inp != NULL) { 493 error = EINVAL; 494 break; 495 } 496 s = splnet(); 497 error = in_pcballoc(so, &udbinfo); 498 splx(s); 499 if (error) 500 break; 501 error = soreserve(so, udp_sendspace, udp_recvspace); 502 if (error) 503 break; 504 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = ip_defttl; 505 break; 506 507 case PRU_DETACH: 508 udp_detach(inp); 509 break; 510 511 case PRU_BIND: 512 s = splnet(); 513 error = in_pcbbind(inp, addr); 514 splx(s); 515 break; 516 517 case PRU_LISTEN: 518 error = EOPNOTSUPP; 519 break; 520 521 case PRU_CONNECT: 522 if (inp->inp_faddr.s_addr != INADDR_ANY) { 523 error = EISCONN; 524 break; 525 } 526 s = splnet(); 527 error = in_pcbconnect(inp, addr); 528 splx(s); 529 if (error == 0) 530 soisconnected(so); 531 break; 532 533 case PRU_CONNECT2: 534 error = EOPNOTSUPP; 535 break; 536 537 case PRU_ACCEPT: 538 error = EOPNOTSUPP; 539 break; 540 541 case PRU_DISCONNECT: 542 if (inp->inp_faddr.s_addr == INADDR_ANY) { 543 error = ENOTCONN; 544 break; 545 } 546 s = splnet(); 547 in_pcbdisconnect(inp); 548 inp->inp_laddr.s_addr = INADDR_ANY; 549 splx(s); 550 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 551 break; 552 553 case PRU_SHUTDOWN: 554 socantsendmore(so); 555 break; 556 557 case PRU_SEND: 558 return (udp_output(inp, m, addr, control)); 559 560 case PRU_ABORT: 561 soisdisconnected(so); 562 udp_detach(inp); 563 break; 564 565 case PRU_SOCKADDR: 566 in_setsockaddr(inp, addr); 567 break; 568 569 case PRU_PEERADDR: 570 in_setpeeraddr(inp, addr); 571 break; 572 573 case PRU_SENSE: 574 /* 575 * stat: don't bother with a blocksize. 576 */ 577 return (0); 578 579 case PRU_SENDOOB: 580 case PRU_FASTTIMO: 581 case PRU_SLOWTIMO: 582 case PRU_PROTORCV: 583 case PRU_PROTOSEND: 584 error = EOPNOTSUPP; 585 break; 586 587 case PRU_RCVD: 588 case PRU_RCVOOB: 589 return (EOPNOTSUPP); /* do not free mbuf's */ 590 591 default: 592 panic("udp_usrreq"); 593 } 594 595 release: 596 if (control) { 597 printf("udp control data unexpectedly retained\n"); 598 m_freem(control); 599 } 600 if (m) 601 m_freem(m); 602 return (error); 603 } 604 605 static void 606 udp_detach(inp) 607 struct inpcb *inp; 608 { 609 int s = splnet(); 610 611 in_pcbdetach(inp); 612 splx(s); 613 } 614