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 1.18 1995/12/14 09:53:49 phk Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/protosw.h> 42 #include <sys/socket.h> 43 #include <sys/socketvar.h> 44 #include <sys/errno.h> 45 #include <sys/stat.h> 46 #include <sys/queue.h> 47 #include <sys/kernel.h> 48 #include <sys/sysctl.h> 49 50 #include <net/if.h> 51 #include <net/route.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/ip.h> 56 #include <netinet/in_pcb.h> 57 #include <netinet/in_var.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/ip_icmp.h> 60 #include <netinet/udp.h> 61 #include <netinet/udp_var.h> 62 63 /* 64 * UDP protocol implementation. 65 * Per RFC 768, August, 1980. 66 */ 67 #ifndef COMPAT_42 68 static int udpcksum = 1; 69 #else 70 static int udpcksum = 0; /* XXX */ 71 #endif 72 SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, 73 &udpcksum, 0, ""); 74 75 static struct inpcbhead udb; /* from udp_var.h */ 76 static struct inpcbinfo udbinfo; 77 78 #ifndef UDBHASHSIZE 79 #define UDBHASHSIZE 64 80 #endif 81 82 static struct udpstat udpstat; /* from udp_var.h */ 83 SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RD, 84 &udpstat, udpstat, ""); 85 86 static struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 87 88 static void udp_detach __P((struct inpcb *)); 89 static int udp_output __P((struct inpcb *, struct mbuf *, struct mbuf *, 90 struct mbuf *)); 91 static void udp_notify __P((struct inpcb *, int)); 92 static struct mbuf *udp_saveopt __P((caddr_t, int, int)); 93 94 void 95 udp_init() 96 { 97 LIST_INIT(&udb); 98 udbinfo.listhead = &udb; 99 udbinfo.hashbase = phashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashsize); 100 } 101 102 void 103 udp_input(m, iphlen) 104 register struct mbuf *m; 105 int iphlen; 106 { 107 register struct ip *ip; 108 register struct udphdr *uh; 109 register struct inpcb *inp; 110 struct mbuf *opts = 0; 111 int len; 112 struct ip save_ip; 113 114 udpstat.udps_ipackets++; 115 116 /* 117 * Strip IP options, if any; should skip this, 118 * make available to user, and use on returned packets, 119 * but we don't yet have a way to check the checksum 120 * with options still present. 121 */ 122 if (iphlen > sizeof (struct ip)) { 123 ip_stripoptions(m, (struct mbuf *)0); 124 iphlen = sizeof(struct ip); 125 } 126 127 /* 128 * Get IP and UDP header together in first mbuf. 129 */ 130 ip = mtod(m, struct ip *); 131 if (m->m_len < iphlen + sizeof(struct udphdr)) { 132 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 133 udpstat.udps_hdrops++; 134 return; 135 } 136 ip = mtod(m, struct ip *); 137 } 138 uh = (struct udphdr *)((caddr_t)ip + iphlen); 139 140 /* 141 * Make mbuf data length reflect UDP length. 142 * If not enough data to reflect UDP length, drop. 143 */ 144 len = ntohs((u_short)uh->uh_ulen); 145 if (ip->ip_len != len) { 146 if (len > ip->ip_len || len < sizeof(struct udphdr)) { 147 udpstat.udps_badlen++; 148 goto bad; 149 } 150 m_adj(m, len - ip->ip_len); 151 /* ip->ip_len = len; */ 152 } 153 /* 154 * Save a copy of the IP header in case we want restore it 155 * for sending an ICMP error message in response. 156 */ 157 save_ip = *ip; 158 159 /* 160 * Checksum extended UDP header and data. 161 */ 162 if (uh->uh_sum) { 163 ((struct ipovly *)ip)->ih_next = 0; 164 ((struct ipovly *)ip)->ih_prev = 0; 165 ((struct ipovly *)ip)->ih_x1 = 0; 166 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 167 uh->uh_sum = in_cksum(m, len + sizeof (struct ip)); 168 if (uh->uh_sum) { 169 udpstat.udps_badsum++; 170 m_freem(m); 171 return; 172 } 173 } 174 175 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 176 in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { 177 struct socket *last; 178 /* 179 * Deliver a multicast or broadcast datagram to *all* sockets 180 * for which the local and remote addresses and ports match 181 * those of the incoming datagram. This allows more than 182 * one process to receive multi/broadcasts on the same port. 183 * (This really ought to be done for unicast datagrams as 184 * well, but that would cause problems with existing 185 * applications that open both address-specific sockets and 186 * a wildcard socket listening to the same port -- they would 187 * end up receiving duplicates of every unicast datagram. 188 * Those applications open the multiple sockets to overcome an 189 * inadequacy of the UDP socket interface, but for backwards 190 * compatibility we avoid the problem here rather than 191 * fixing the interface. Maybe 4.5BSD will remedy this?) 192 */ 193 194 /* 195 * Construct sockaddr format source address. 196 */ 197 udp_in.sin_port = uh->uh_sport; 198 udp_in.sin_addr = ip->ip_src; 199 m->m_len -= sizeof (struct udpiphdr); 200 m->m_data += sizeof (struct udpiphdr); 201 /* 202 * Locate pcb(s) for datagram. 203 * (Algorithm copied from raw_intr().) 204 */ 205 last = NULL; 206 for (inp = udb.lh_first; inp != NULL; inp = inp->inp_list.le_next) { 207 if (inp->inp_lport != uh->uh_dport) 208 continue; 209 if (inp->inp_laddr.s_addr != INADDR_ANY) { 210 if (inp->inp_laddr.s_addr != 211 ip->ip_dst.s_addr) 212 continue; 213 } 214 if (inp->inp_faddr.s_addr != INADDR_ANY) { 215 if (inp->inp_faddr.s_addr != 216 ip->ip_src.s_addr || 217 inp->inp_fport != uh->uh_sport) 218 continue; 219 } 220 221 if (last != NULL) { 222 struct mbuf *n; 223 224 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 225 if (sbappendaddr(&last->so_rcv, 226 (struct sockaddr *)&udp_in, 227 n, (struct mbuf *)0) == 0) { 228 m_freem(n); 229 udpstat.udps_fullsock++; 230 } else 231 sorwakeup(last); 232 } 233 } 234 last = inp->inp_socket; 235 /* 236 * Don't look for additional matches if this one does 237 * not have either the SO_REUSEPORT or SO_REUSEADDR 238 * socket options set. This heuristic avoids searching 239 * through all pcbs in the common case of a non-shared 240 * port. It * assumes that an application will never 241 * clear these options after setting them. 242 */ 243 if ((last->so_options&(SO_REUSEPORT|SO_REUSEADDR) == 0)) 244 break; 245 } 246 247 if (last == NULL) { 248 /* 249 * No matching pcb found; discard datagram. 250 * (No need to send an ICMP Port Unreachable 251 * for a broadcast or multicast datgram.) 252 */ 253 udpstat.udps_noportbcast++; 254 goto bad; 255 } 256 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 257 m, (struct mbuf *)0) == 0) { 258 udpstat.udps_fullsock++; 259 goto bad; 260 } 261 sorwakeup(last); 262 return; 263 } 264 /* 265 * Locate pcb for datagram. First look for an exact match. 266 */ 267 inp = in_pcblookuphash(&udbinfo, ip->ip_src, uh->uh_sport, 268 ip->ip_dst, uh->uh_dport); 269 /* 270 * ...and if that fails, do a wildcard search. 271 */ 272 if (inp == NULL) { 273 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, ip->ip_dst, 274 uh->uh_dport, INPLOOKUP_WILDCARD); 275 } 276 if (inp == NULL) { 277 udpstat.udps_noport++; 278 if (m->m_flags & (M_BCAST | M_MCAST)) { 279 udpstat.udps_noportbcast++; 280 goto bad; 281 } 282 *ip = save_ip; 283 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); 284 return; 285 } 286 287 /* 288 * Construct sockaddr format source address. 289 * Stuff source address and datagram in user buffer. 290 */ 291 udp_in.sin_port = uh->uh_sport; 292 udp_in.sin_addr = ip->ip_src; 293 if (inp->inp_flags & INP_CONTROLOPTS) { 294 struct mbuf **mp = &opts; 295 296 if (inp->inp_flags & INP_RECVDSTADDR) { 297 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 298 sizeof(struct in_addr), IP_RECVDSTADDR); 299 if (*mp) 300 mp = &(*mp)->m_next; 301 } 302 #ifdef notyet 303 /* options were tossed above */ 304 if (inp->inp_flags & INP_RECVOPTS) { 305 *mp = udp_saveopt((caddr_t) opts_deleted_above, 306 sizeof(struct in_addr), IP_RECVOPTS); 307 if (*mp) 308 mp = &(*mp)->m_next; 309 } 310 /* ip_srcroute doesn't do what we want here, need to fix */ 311 if (inp->inp_flags & INP_RECVRETOPTS) { 312 *mp = udp_saveopt((caddr_t) ip_srcroute(), 313 sizeof(struct in_addr), IP_RECVRETOPTS); 314 if (*mp) 315 mp = &(*mp)->m_next; 316 } 317 #endif 318 } 319 iphlen += sizeof(struct udphdr); 320 m->m_len -= iphlen; 321 m->m_pkthdr.len -= iphlen; 322 m->m_data += iphlen; 323 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 324 m, opts) == 0) { 325 udpstat.udps_fullsock++; 326 goto bad; 327 } 328 sorwakeup(inp->inp_socket); 329 return; 330 bad: 331 m_freem(m); 332 if (opts) 333 m_freem(opts); 334 } 335 336 /* 337 * Create a "control" mbuf containing the specified data 338 * with the specified type for presentation with a datagram. 339 */ 340 struct mbuf * 341 udp_saveopt(p, size, type) 342 caddr_t p; 343 register int size; 344 int type; 345 { 346 register struct cmsghdr *cp; 347 struct mbuf *m; 348 349 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 350 return ((struct mbuf *) NULL); 351 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 352 (void)memcpy(CMSG_DATA(cp), p, size); 353 size += sizeof(*cp); 354 m->m_len = size; 355 cp->cmsg_len = size; 356 cp->cmsg_level = IPPROTO_IP; 357 cp->cmsg_type = type; 358 return (m); 359 } 360 361 /* 362 * Notify a udp user of an asynchronous error; 363 * just wake up so that he can collect error status. 364 */ 365 static void 366 udp_notify(inp, errno) 367 register struct inpcb *inp; 368 int errno; 369 { 370 inp->inp_socket->so_error = errno; 371 sorwakeup(inp->inp_socket); 372 sowwakeup(inp->inp_socket); 373 } 374 375 void 376 udp_ctlinput(cmd, sa, vip) 377 int cmd; 378 struct sockaddr *sa; 379 void *vip; 380 { 381 register struct ip *ip = vip; 382 register struct udphdr *uh; 383 384 if (!PRC_IS_REDIRECT(cmd) && 385 ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)) 386 return; 387 if (ip) { 388 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 389 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 390 cmd, udp_notify); 391 } else 392 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 393 } 394 395 static int 396 udp_output(inp, m, addr, control) 397 register struct inpcb *inp; 398 register struct mbuf *m; 399 struct mbuf *addr, *control; 400 { 401 register struct udpiphdr *ui; 402 register int len = m->m_pkthdr.len; 403 struct in_addr laddr; 404 int s = 0, error = 0; 405 406 if (control) 407 m_freem(control); /* XXX */ 408 409 if (addr) { 410 laddr = inp->inp_laddr; 411 if (inp->inp_faddr.s_addr != INADDR_ANY) { 412 error = EISCONN; 413 goto release; 414 } 415 /* 416 * Must block input while temporarily connected. 417 */ 418 s = splnet(); 419 error = in_pcbconnect(inp, addr); 420 if (error) { 421 splx(s); 422 goto release; 423 } 424 } else { 425 if (inp->inp_faddr.s_addr == INADDR_ANY) { 426 error = ENOTCONN; 427 goto release; 428 } 429 } 430 /* 431 * Calculate data length and get a mbuf 432 * for UDP and IP headers. 433 */ 434 M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT); 435 if (m == 0) { 436 error = ENOBUFS; 437 if (addr) 438 splx(s); 439 goto release; 440 } 441 442 /* 443 * Fill in mbuf with extended UDP header 444 * and addresses and length put into network format. 445 */ 446 ui = mtod(m, struct udpiphdr *); 447 ui->ui_next = ui->ui_prev = 0; 448 ui->ui_x1 = 0; 449 ui->ui_pr = IPPROTO_UDP; 450 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 451 ui->ui_src = inp->inp_laddr; 452 ui->ui_dst = inp->inp_faddr; 453 ui->ui_sport = inp->inp_lport; 454 ui->ui_dport = inp->inp_fport; 455 ui->ui_ulen = ui->ui_len; 456 457 /* 458 * Stuff checksum and output datagram. 459 */ 460 ui->ui_sum = 0; 461 if (udpcksum) { 462 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 463 ui->ui_sum = 0xffff; 464 } 465 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 466 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 467 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 468 udpstat.udps_opackets++; 469 error = ip_output(m, inp->inp_options, &inp->inp_route, 470 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST), 471 inp->inp_moptions); 472 473 if (addr) { 474 in_pcbdisconnect(inp); 475 inp->inp_laddr = laddr; 476 splx(s); 477 } 478 return (error); 479 480 release: 481 m_freem(m); 482 return (error); 483 } 484 485 static u_long udp_sendspace = 9216; /* really max datagram size */ 486 /* 40 1K datagrams */ 487 SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW, 488 &udp_sendspace, 0, ""); 489 490 static u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 491 SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW, 492 &udp_recvspace, 0, ""); 493 494 /*ARGSUSED*/ 495 int 496 udp_usrreq(so, req, m, addr, control) 497 struct socket *so; 498 int req; 499 struct mbuf *m, *addr, *control; 500 { 501 struct inpcb *inp = sotoinpcb(so); 502 int error = 0; 503 int s; 504 505 if (req == PRU_CONTROL) 506 return (in_control(so, (u_long)m, (caddr_t)addr, 507 (struct ifnet *)control)); 508 if (inp == NULL && req != PRU_ATTACH) { 509 error = EINVAL; 510 goto release; 511 } 512 /* 513 * Note: need to block udp_input while changing 514 * the udp pcb queue and/or pcb addresses. 515 */ 516 switch (req) { 517 518 case PRU_ATTACH: 519 if (inp != NULL) { 520 error = EINVAL; 521 break; 522 } 523 s = splnet(); 524 error = in_pcballoc(so, &udbinfo); 525 splx(s); 526 if (error) 527 break; 528 error = soreserve(so, udp_sendspace, udp_recvspace); 529 if (error) 530 break; 531 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = ip_defttl; 532 break; 533 534 case PRU_DETACH: 535 udp_detach(inp); 536 break; 537 538 case PRU_BIND: 539 s = splnet(); 540 error = in_pcbbind(inp, addr); 541 splx(s); 542 break; 543 544 case PRU_LISTEN: 545 error = EOPNOTSUPP; 546 break; 547 548 case PRU_CONNECT: 549 if (inp->inp_faddr.s_addr != INADDR_ANY) { 550 error = EISCONN; 551 break; 552 } 553 s = splnet(); 554 error = in_pcbconnect(inp, addr); 555 splx(s); 556 if (error == 0) 557 soisconnected(so); 558 break; 559 560 case PRU_CONNECT2: 561 error = EOPNOTSUPP; 562 break; 563 564 case PRU_ACCEPT: 565 error = EOPNOTSUPP; 566 break; 567 568 case PRU_DISCONNECT: 569 if (inp->inp_faddr.s_addr == INADDR_ANY) { 570 error = ENOTCONN; 571 break; 572 } 573 s = splnet(); 574 in_pcbdisconnect(inp); 575 inp->inp_laddr.s_addr = INADDR_ANY; 576 splx(s); 577 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 578 break; 579 580 case PRU_SHUTDOWN: 581 socantsendmore(so); 582 break; 583 584 case PRU_SEND: 585 return (udp_output(inp, m, addr, control)); 586 587 case PRU_ABORT: 588 soisdisconnected(so); 589 udp_detach(inp); 590 break; 591 592 case PRU_SOCKADDR: 593 in_setsockaddr(inp, addr); 594 break; 595 596 case PRU_PEERADDR: 597 in_setpeeraddr(inp, addr); 598 break; 599 600 case PRU_SENSE: 601 /* 602 * stat: don't bother with a blocksize. 603 */ 604 return (0); 605 606 case PRU_SENDOOB: 607 case PRU_FASTTIMO: 608 case PRU_SLOWTIMO: 609 case PRU_PROTORCV: 610 case PRU_PROTOSEND: 611 error = EOPNOTSUPP; 612 break; 613 614 case PRU_RCVD: 615 case PRU_RCVOOB: 616 return (EOPNOTSUPP); /* do not free mbuf's */ 617 618 default: 619 panic("udp_usrreq"); 620 } 621 622 release: 623 if (control) { 624 printf("udp control data unexpectedly retained\n"); 625 m_freem(control); 626 } 627 if (m) 628 m_freem(m); 629 return (error); 630 } 631 632 static void 633 udp_detach(inp) 634 struct inpcb *inp; 635 { 636 int s = splnet(); 637 638 in_pcbdetach(inp); 639 splx(s); 640 } 641