udp_usrreq.c revision 1.6
1 /* 2 * Copyright (c) 1982, 1986, 1988, 1990 Regents of the University of California. 3 * 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 * from: @(#)udp_usrreq.c 7.20 (Berkeley) 4/20/91 34 * $Id: udp_usrreq.c,v 1.6 1994/01/08 21:22:06 mycroft Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/malloc.h> 39 #include <sys/mbuf.h> 40 #include <sys/protosw.h> 41 #include <sys/socket.h> 42 #include <sys/socketvar.h> 43 #include <sys/stat.h> 44 45 #include <net/if.h> 46 #include <net/route.h> 47 48 #include <netinet/in.h> 49 #include <netinet/in_systm.h> 50 #include <netinet/ip.h> 51 #include <netinet/in_pcb.h> 52 #include <netinet/ip_var.h> 53 #include <netinet/ip_icmp.h> 54 #include <netinet/udp.h> 55 #include <netinet/udp_var.h> 56 57 struct inpcb *udp_last_inpcb = &udb; 58 59 /* 60 * UDP protocol implementation. 61 * Per RFC 768, August, 1980. 62 */ 63 udp_init() 64 { 65 66 udb.inp_next = udb.inp_prev = &udb; 67 } 68 69 #ifndef COMPAT_42 70 int udpcksum = 1; 71 #else 72 int udpcksum = 0; /* XXX */ 73 #endif 74 int udp_ttl = UDP_TTL; 75 76 struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 77 78 udp_input(m, iphlen) 79 register struct mbuf *m; 80 int iphlen; 81 { 82 register struct ip *ip; 83 register struct udphdr *uh; 84 register struct inpcb *inp; 85 struct mbuf *opts = 0; 86 int len; 87 struct ip save_ip; 88 89 udpstat.udps_ipackets++; 90 91 /* 92 * Strip IP options, if any; should skip this, 93 * make available to user, and use on returned packets, 94 * but we don't yet have a way to check the checksum 95 * with options still present. 96 */ 97 if (iphlen > sizeof (struct ip)) { 98 ip_stripoptions(m, (struct mbuf *)0); 99 iphlen = sizeof(struct ip); 100 } 101 102 /* 103 * Get IP and UDP header together in first mbuf. 104 */ 105 ip = mtod(m, struct ip *); 106 if (m->m_len < iphlen + sizeof(struct udphdr)) { 107 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 108 udpstat.udps_hdrops++; 109 return; 110 } 111 ip = mtod(m, struct ip *); 112 } 113 uh = (struct udphdr *)((caddr_t)ip + iphlen); 114 115 /* 116 * Make mbuf data length reflect UDP length. 117 * If not enough data to reflect UDP length, drop. 118 */ 119 len = ntohs((u_short)uh->uh_ulen); 120 if (ip->ip_len != len) { 121 if (len > ip->ip_len) { 122 udpstat.udps_badlen++; 123 goto bad; 124 } 125 m_adj(m, len - ip->ip_len); 126 /* ip->ip_len = len; */ 127 } 128 /* 129 * Save a copy of the IP header in case we want restore it 130 * for sending an ICMP error message in response. 131 */ 132 save_ip = *ip; 133 134 /* 135 * Checksum extended UDP header and data. 136 */ 137 if (udpcksum && uh->uh_sum) { 138 ((struct ipovly *)ip)->ih_next = 0; 139 ((struct ipovly *)ip)->ih_prev = 0; 140 ((struct ipovly *)ip)->ih_x1 = 0; 141 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 142 if (uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) { 143 udpstat.udps_badsum++; 144 m_freem(m); 145 return; 146 } 147 } 148 #ifdef MULTICAST 149 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 150 in_broadcast(ip->ip_dst)) { 151 struct socket *last; 152 /* 153 * Deliver a multicast or broadcast datagram to *all* sockets 154 * for which the local and remote addresses and ports match 155 * those of the incoming datagram. This allows more than 156 * one process to receive multi/broadcasts on the same port. 157 * (This really ought to be done for unicast datagrams as 158 * well, but that would cause problems with existing 159 * applications that open both address-specific sockets and 160 * a wildcard socket listening to the same port -- they would 161 * end up receiving duplicates of every unicast datagram. 162 * Those applications open the multiple sockets to overcome an 163 * inadequacy of the UDP socket interface, but for backwards 164 * compatibility we avoid the problem here rather than 165 * fixing the interface. Maybe 4.4BSD will remedy this?) 166 */ 167 /* 168 * Construct sockaddr format source address. 169 */ 170 udp_in.sin_port = uh->uh_sport; 171 udp_in.sin_addr = ip->ip_src; 172 m->m_len -= sizeof (struct udpiphdr); 173 m->m_data += sizeof (struct udpiphdr); 174 /* 175 * Locate pcb(s) for datagram. 176 * (Algorithm copied from raw_intr().) 177 */ 178 last = NULL; 179 for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) { 180 if (inp->inp_lport != uh->uh_dport) 181 continue; 182 if (inp->inp_laddr.s_addr != INADDR_ANY) { 183 if (inp->inp_laddr.s_addr != 184 ip->ip_dst.s_addr) 185 continue; 186 } 187 if (inp->inp_faddr.s_addr != INADDR_ANY) { 188 if (inp->inp_faddr.s_addr != 189 ip->ip_src.s_addr || 190 inp->inp_fport != uh->uh_sport) 191 continue; 192 } 193 194 if (last != NULL) { 195 struct mbuf *n; 196 197 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 198 if (sbappendaddr(&last->so_rcv, 199 (struct sockaddr *)&udp_in, 200 n, (struct mbuf *)0) == 0) 201 m_freem(n); 202 else 203 sorwakeup(last); 204 } 205 } 206 last = inp->inp_socket; 207 /* 208 * Don't look for additional matches if this one 209 * does not have the SO_REUSEADDR socket option set. 210 * This heuristic avoids searching through all pcbs 211 * in the common case of a non-shared port. It 212 * assumes that an application will never clear 213 * the SO_REUSEADDR option after setting it. 214 */ 215 if ((last->so_options & SO_REUSEADDR) == 0) 216 break; 217 } 218 219 if (last == NULL) { 220 /* 221 * No matching pcb found; discard datagram. 222 * (No need to send an ICMP Port Unreachable 223 * for a broadcast or multicast datgram.) 224 */ 225 goto bad; 226 } 227 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 228 m, (struct mbuf *)0) == 0) 229 goto bad; 230 sorwakeup(last); 231 return; 232 } 233 #endif 234 /* 235 * Locate pcb for datagram. 236 */ 237 inp = udp_last_inpcb; 238 if (inp->inp_lport != uh->uh_dport || 239 inp->inp_fport != uh->uh_sport || 240 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 241 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 242 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, 243 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 244 if (inp) 245 udp_last_inpcb = inp; 246 udpstat.udpps_pcbcachemiss++; 247 } 248 if (inp == 0) { 249 /* don't send ICMP response for broadcast packet */ 250 udpstat.udps_noport++; 251 #ifndef MULTICAST 252 /* XXX why don't we do this with MULTICAST? */ 253 if (m->m_flags & (M_BCAST | M_MCAST)) { 254 udpstat.udps_noportbcast++; 255 goto bad; 256 } 257 #endif 258 *ip = save_ip; 259 ip->ip_len += iphlen; 260 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT); 261 return; 262 } 263 264 /* 265 * Construct sockaddr format source address. 266 * Stuff source address and datagram in user buffer. 267 */ 268 udp_in.sin_port = uh->uh_sport; 269 udp_in.sin_addr = ip->ip_src; 270 if (inp->inp_flags & INP_CONTROLOPTS) { 271 struct mbuf **mp = &opts; 272 struct mbuf *udp_saveopt(); 273 274 if (inp->inp_flags & INP_RECVDSTADDR) { 275 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 276 sizeof(struct in_addr), IP_RECVDSTADDR); 277 if (*mp) 278 mp = &(*mp)->m_next; 279 } 280 #ifdef notyet 281 /* options were tossed above */ 282 if (inp->inp_flags & INP_RECVOPTS) { 283 *mp = udp_saveopt((caddr_t) opts_deleted_above, 284 sizeof(struct in_addr), IP_RECVOPTS); 285 if (*mp) 286 mp = &(*mp)->m_next; 287 } 288 /* ip_srcroute doesn't do what we want here, need to fix */ 289 if (inp->inp_flags & INP_RECVRETOPTS) { 290 *mp = udp_saveopt((caddr_t) ip_srcroute(), 291 sizeof(struct in_addr), IP_RECVRETOPTS); 292 if (*mp) 293 mp = &(*mp)->m_next; 294 } 295 #endif 296 } 297 iphlen += sizeof(struct udphdr); 298 m->m_len -= iphlen; 299 m->m_pkthdr.len -= iphlen; 300 m->m_data += iphlen; 301 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 302 m, opts) == 0) { 303 udpstat.udps_fullsock++; 304 goto bad; 305 } 306 sorwakeup(inp->inp_socket); 307 return; 308 bad: 309 m_freem(m); 310 if (opts) 311 m_freem(opts); 312 } 313 314 /* 315 * Create a "control" mbuf containing the specified data 316 * with the specified type for presentation with a datagram. 317 */ 318 struct mbuf * 319 udp_saveopt(p, size, type) 320 caddr_t p; 321 register int size; 322 int type; 323 { 324 register struct cmsghdr *cp; 325 struct mbuf *m; 326 327 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 328 return ((struct mbuf *) NULL); 329 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 330 bcopy(p, (caddr_t)(cp + 1), size); 331 size += sizeof(*cp); 332 m->m_len = size; 333 cp->cmsg_len = size; 334 cp->cmsg_level = IPPROTO_IP; 335 cp->cmsg_type = type; 336 return (m); 337 } 338 339 /* 340 * Notify a udp user of an asynchronous error; 341 * just wake up so that he can collect error status. 342 */ 343 udp_notify(inp, errno) 344 register struct inpcb *inp; 345 { 346 347 inp->inp_socket->so_error = errno; 348 sorwakeup(inp->inp_socket); 349 sowwakeup(inp->inp_socket); 350 } 351 352 udp_ctlinput(cmd, sa, ip) 353 int cmd; 354 struct sockaddr *sa; 355 register struct ip *ip; 356 { 357 register struct udphdr *uh; 358 extern struct in_addr zeroin_addr; 359 extern u_char inetctlerrmap[]; 360 361 if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 362 return; 363 if (ip) { 364 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 365 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 366 cmd, udp_notify); 367 } else 368 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 369 } 370 371 udp_output(inp, m, addr, control) 372 register struct inpcb *inp; 373 register struct mbuf *m; 374 struct mbuf *addr, *control; 375 { 376 register struct udpiphdr *ui; 377 register int len = m->m_pkthdr.len; 378 struct in_addr laddr; 379 int s, error = 0; 380 381 if (control) 382 m_freem(control); /* XXX */ 383 384 if (addr) { 385 laddr = inp->inp_laddr; 386 if (inp->inp_faddr.s_addr != INADDR_ANY) { 387 error = EISCONN; 388 goto release; 389 } 390 /* 391 * Must block input while temporarily connected. 392 */ 393 s = splnet(); 394 error = in_pcbconnect(inp, addr); 395 if (error) { 396 splx(s); 397 goto release; 398 } 399 } else { 400 if (inp->inp_faddr.s_addr == INADDR_ANY) { 401 error = ENOTCONN; 402 goto release; 403 } 404 } 405 /* 406 * Calculate data length and get a mbuf 407 * for UDP and IP headers. 408 */ 409 M_PREPEND(m, sizeof(struct udpiphdr), M_WAIT); 410 411 /* 412 * Fill in mbuf with extended UDP header 413 * and addresses and length put into network format. 414 */ 415 ui = mtod(m, struct udpiphdr *); 416 ui->ui_next = ui->ui_prev = 0; 417 ui->ui_x1 = 0; 418 ui->ui_pr = IPPROTO_UDP; 419 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 420 ui->ui_src = inp->inp_laddr; 421 ui->ui_dst = inp->inp_faddr; 422 ui->ui_sport = inp->inp_lport; 423 ui->ui_dport = inp->inp_fport; 424 ui->ui_ulen = ui->ui_len; 425 426 /* 427 * Stuff checksum and output datagram. 428 */ 429 ui->ui_sum = 0; 430 if (udpcksum) { 431 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 432 ui->ui_sum = 0xffff; 433 } 434 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 435 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 436 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 437 udpstat.udps_opackets++; 438 error = ip_output(m, inp->inp_options, &inp->inp_route, 439 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST) 440 #ifdef MULTICAST 441 | IP_MULTICASTOPTS, inp->inp_moptions 442 #endif 443 ); 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 u_long udp_sendspace = 9216; /* really max datagram size */ 458 u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 459 /* 40 1K datagrams */ 460 461 /*ARGSUSED*/ 462 udp_usrreq(so, req, m, addr, control) 463 struct socket *so; 464 int req; 465 struct mbuf *m, *addr, *control; 466 { 467 struct inpcb *inp = sotoinpcb(so); 468 int error = 0; 469 int s; 470 471 if (req == PRU_CONTROL) 472 return (in_control(so, (int)m, (caddr_t)addr, 473 (struct ifnet *)control)); 474 if (inp == NULL && req != PRU_ATTACH) { 475 error = EINVAL; 476 goto release; 477 } 478 /* 479 * Note: need to block udp_input while changing 480 * the udp pcb queue and/or pcb addresses. 481 */ 482 switch (req) { 483 484 case PRU_ATTACH: 485 if (inp != NULL) { 486 error = EINVAL; 487 break; 488 } 489 s = splnet(); 490 error = in_pcballoc(so, &udb); 491 splx(s); 492 if (error) 493 break; 494 error = soreserve(so, udp_sendspace, udp_recvspace); 495 if (error) 496 break; 497 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = udp_ttl; 498 break; 499 500 case PRU_DETACH: 501 udp_detach(inp); 502 break; 503 504 case PRU_BIND: 505 s = splnet(); 506 error = in_pcbbind(inp, addr); 507 splx(s); 508 break; 509 510 case PRU_LISTEN: 511 error = EOPNOTSUPP; 512 break; 513 514 case PRU_CONNECT: 515 if (inp->inp_faddr.s_addr != INADDR_ANY) { 516 error = EISCONN; 517 break; 518 } 519 s = splnet(); 520 error = in_pcbconnect(inp, addr); 521 splx(s); 522 if (error == 0) 523 soisconnected(so); 524 break; 525 526 case PRU_CONNECT2: 527 error = EOPNOTSUPP; 528 break; 529 530 case PRU_ACCEPT: 531 error = EOPNOTSUPP; 532 break; 533 534 case PRU_DISCONNECT: 535 if (inp->inp_faddr.s_addr == INADDR_ANY) { 536 error = ENOTCONN; 537 break; 538 } 539 s = splnet(); 540 in_pcbdisconnect(inp); 541 inp->inp_laddr.s_addr = INADDR_ANY; 542 splx(s); 543 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 544 break; 545 546 case PRU_SHUTDOWN: 547 socantsendmore(so); 548 break; 549 550 case PRU_SEND: 551 return (udp_output(inp, m, addr, control)); 552 553 case PRU_ABORT: 554 soisdisconnected(so); 555 udp_detach(inp); 556 break; 557 558 case PRU_SOCKADDR: 559 in_setsockaddr(inp, addr); 560 break; 561 562 case PRU_PEERADDR: 563 in_setpeeraddr(inp, addr); 564 break; 565 566 case PRU_SENSE: 567 /* 568 * stat: don't bother with a blocksize. 569 */ 570 return (0); 571 572 case PRU_SENDOOB: 573 case PRU_FASTTIMO: 574 case PRU_SLOWTIMO: 575 case PRU_PROTORCV: 576 case PRU_PROTOSEND: 577 error = EOPNOTSUPP; 578 break; 579 580 case PRU_RCVD: 581 case PRU_RCVOOB: 582 return (EOPNOTSUPP); /* do not free mbuf's */ 583 584 default: 585 panic("udp_usrreq"); 586 } 587 588 release: 589 if (control) { 590 printf("udp control data unexpectedly retained\n"); 591 m_freem(control); 592 } 593 if (m) 594 m_freem(m); 595 return (error); 596 } 597 598 udp_detach(inp) 599 struct inpcb *inp; 600 { 601 int s = splnet(); 602 603 if (inp == udp_last_inpcb) 604 udp_last_inpcb = &udb; 605 in_pcbdetach(inp); 606 splx(s); 607 } 608
Indexes created Wed Sep 24 05:09:52 GMT 2025