udp_usrreq.c revision 1.5
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 1.5 1993/12/18 00:42:15 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 /* 169 * Construct sockaddr format source address. 170 */ 171 udp_in.sin_port = uh->uh_sport; 172 udp_in.sin_addr = ip->ip_src; 173 m->m_len -= sizeof (struct udpiphdr); 174 m->m_data += sizeof (struct udpiphdr); 175 /* 176 * Locate pcb(s) for datagram. 177 * (Algorithm copied from raw_intr().) 178 */ 179 last = NULL; 180 for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) { 181 if (inp->inp_lport != uh->uh_dport) 182 continue; 183 if (inp->inp_laddr.s_addr != INADDR_ANY) { 184 if (inp->inp_laddr.s_addr != 185 ip->ip_dst.s_addr) 186 continue; 187 } 188 if (inp->inp_faddr.s_addr != INADDR_ANY) { 189 if (inp->inp_faddr.s_addr != 190 ip->ip_src.s_addr || 191 inp->inp_fport != uh->uh_sport) 192 continue; 193 } 194 195 if (last != NULL) { 196 struct mbuf *n; 197 198 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 199 if (sbappendaddr(&last->so_rcv, 200 (struct sockaddr *)&udp_in, 201 n, (struct mbuf *)0) == 0) 202 m_freem(n); 203 else 204 sorwakeup(last); 205 } 206 } 207 last = inp->inp_socket; 208 /* 209 * Don't look for additional matches if this one 210 * does not have the SO_REUSEADDR socket option set. 211 * This heuristic avoids searching through all pcbs 212 * in the common case of a non-shared port. It 213 * assumes that an application will never clear 214 * the SO_REUSEADDR option after setting it. 215 */ 216 if ((last->so_options & SO_REUSEADDR) == 0) 217 break; 218 } 219 220 if (last == NULL) { 221 /* 222 * No matching pcb found; discard datagram. 223 * (No need to send an ICMP Port Unreachable 224 * for a broadcast or multicast datgram.) 225 */ 226 goto bad; 227 } 228 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 229 m, (struct mbuf *)0) == 0) 230 goto bad; 231 sorwakeup(last); 232 return; 233 } 234 #endif 235 /* 236 * Locate pcb for datagram. 237 */ 238 inp = udp_last_inpcb; 239 if (inp->inp_lport != uh->uh_dport || 240 inp->inp_fport != uh->uh_sport || 241 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 242 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 243 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, 244 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 245 if (inp) 246 udp_last_inpcb = inp; 247 udpstat.udpps_pcbcachemiss++; 248 } 249 if (inp == 0) { 250 /* don't send ICMP response for broadcast packet */ 251 udpstat.udps_noport++; 252 #ifndef MULTICAST 253 /* XXX why don't we do this with MULTICAST? */ 254 if (m->m_flags & (M_BCAST | M_MCAST)) { 255 udpstat.udps_noportbcast++; 256 goto bad; 257 } 258 #endif 259 *ip = save_ip; 260 ip->ip_len += iphlen; 261 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT); 262 return; 263 } 264 265 /* 266 * Construct sockaddr format source address. 267 * Stuff source address and datagram in user buffer. 268 */ 269 udp_in.sin_port = uh->uh_sport; 270 udp_in.sin_addr = ip->ip_src; 271 if (inp->inp_flags & INP_CONTROLOPTS) { 272 struct mbuf **mp = &opts; 273 struct mbuf *udp_saveopt(); 274 275 if (inp->inp_flags & INP_RECVDSTADDR) { 276 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 277 sizeof(struct in_addr), IP_RECVDSTADDR); 278 if (*mp) 279 mp = &(*mp)->m_next; 280 } 281 #ifdef notyet 282 /* options were tossed above */ 283 if (inp->inp_flags & INP_RECVOPTS) { 284 *mp = udp_saveopt((caddr_t) opts_deleted_above, 285 sizeof(struct in_addr), IP_RECVOPTS); 286 if (*mp) 287 mp = &(*mp)->m_next; 288 } 289 /* ip_srcroute doesn't do what we want here, need to fix */ 290 if (inp->inp_flags & INP_RECVRETOPTS) { 291 *mp = udp_saveopt((caddr_t) ip_srcroute(), 292 sizeof(struct in_addr), IP_RECVRETOPTS); 293 if (*mp) 294 mp = &(*mp)->m_next; 295 } 296 #endif 297 } 298 iphlen += sizeof(struct udphdr); 299 m->m_len -= iphlen; 300 m->m_pkthdr.len -= iphlen; 301 m->m_data += iphlen; 302 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 303 m, opts) == 0) { 304 udpstat.udps_fullsock++; 305 goto bad; 306 } 307 sorwakeup(inp->inp_socket); 308 return; 309 bad: 310 m_freem(m); 311 if (opts) 312 m_freem(opts); 313 } 314 315 /* 316 * Create a "control" mbuf containing the specified data 317 * with the specified type for presentation with a datagram. 318 */ 319 struct mbuf * 320 udp_saveopt(p, size, type) 321 caddr_t p; 322 register int size; 323 int type; 324 { 325 register struct cmsghdr *cp; 326 struct mbuf *m; 327 328 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 329 return ((struct mbuf *) NULL); 330 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 331 bcopy(p, (caddr_t)(cp + 1), size); 332 size += sizeof(*cp); 333 m->m_len = size; 334 cp->cmsg_len = size; 335 cp->cmsg_level = IPPROTO_IP; 336 cp->cmsg_type = type; 337 return (m); 338 } 339 340 /* 341 * Notify a udp user of an asynchronous error; 342 * just wake up so that he can collect error status. 343 */ 344 udp_notify(inp, errno) 345 register struct inpcb *inp; 346 { 347 348 inp->inp_socket->so_error = errno; 349 sorwakeup(inp->inp_socket); 350 sowwakeup(inp->inp_socket); 351 } 352 353 udp_ctlinput(cmd, sa, ip) 354 int cmd; 355 struct sockaddr *sa; 356 register struct ip *ip; 357 { 358 register struct udphdr *uh; 359 extern struct in_addr zeroin_addr; 360 extern u_char inetctlerrmap[]; 361 362 if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 363 return; 364 if (ip) { 365 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 366 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 367 cmd, udp_notify); 368 } else 369 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 370 } 371 372 udp_output(inp, m, addr, control) 373 register struct inpcb *inp; 374 register struct mbuf *m; 375 struct mbuf *addr, *control; 376 { 377 register struct udpiphdr *ui; 378 register int len = m->m_pkthdr.len; 379 struct in_addr laddr; 380 int s, error = 0; 381 382 if (control) 383 m_freem(control); /* XXX */ 384 385 if (addr) { 386 laddr = inp->inp_laddr; 387 if (inp->inp_faddr.s_addr != INADDR_ANY) { 388 error = EISCONN; 389 goto release; 390 } 391 /* 392 * Must block input while temporarily connected. 393 */ 394 s = splnet(); 395 error = in_pcbconnect(inp, addr); 396 if (error) { 397 splx(s); 398 goto release; 399 } 400 } else { 401 if (inp->inp_faddr.s_addr == INADDR_ANY) { 402 error = ENOTCONN; 403 goto release; 404 } 405 } 406 /* 407 * Calculate data length and get a mbuf 408 * for UDP and IP headers. 409 */ 410 M_PREPEND(m, sizeof(struct udpiphdr), M_WAIT); 411 412 /* 413 * Fill in mbuf with extended UDP header 414 * and addresses and length put into network format. 415 */ 416 ui = mtod(m, struct udpiphdr *); 417 ui->ui_next = ui->ui_prev = 0; 418 ui->ui_x1 = 0; 419 ui->ui_pr = IPPROTO_UDP; 420 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 421 ui->ui_src = inp->inp_laddr; 422 ui->ui_dst = inp->inp_faddr; 423 ui->ui_sport = inp->inp_lport; 424 ui->ui_dport = inp->inp_fport; 425 ui->ui_ulen = ui->ui_len; 426 427 /* 428 * Stuff checksum and output datagram. 429 */ 430 ui->ui_sum = 0; 431 if (udpcksum) { 432 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 433 ui->ui_sum = 0xffff; 434 } 435 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 436 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 437 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 438 udpstat.udps_opackets++; 439 error = ip_output(m, inp->inp_options, &inp->inp_route, 440 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST) 441 #ifdef MULTICAST 442 | IP_MULTICASTOPTS, inp->inp_moptions 443 #endif 444 ); 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 u_long udp_sendspace = 9216; /* really max datagram size */ 459 u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 460 /* 40 1K datagrams */ 461 462 /*ARGSUSED*/ 463 udp_usrreq(so, req, m, addr, control) 464 struct socket *so; 465 int req; 466 struct mbuf *m, *addr, *control; 467 { 468 struct inpcb *inp = sotoinpcb(so); 469 int error = 0; 470 int s; 471 472 if (req == PRU_CONTROL) 473 return (in_control(so, (int)m, (caddr_t)addr, 474 (struct ifnet *)control)); 475 if (inp == NULL && req != PRU_ATTACH) { 476 error = EINVAL; 477 goto release; 478 } 479 /* 480 * Note: need to block udp_input while changing 481 * the udp pcb queue and/or pcb addresses. 482 */ 483 switch (req) { 484 485 case PRU_ATTACH: 486 if (inp != NULL) { 487 error = EINVAL; 488 break; 489 } 490 s = splnet(); 491 error = in_pcballoc(so, &udb); 492 splx(s); 493 if (error) 494 break; 495 error = soreserve(so, udp_sendspace, udp_recvspace); 496 if (error) 497 break; 498 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = udp_ttl; 499 break; 500 501 case PRU_DETACH: 502 udp_detach(inp); 503 break; 504 505 case PRU_BIND: 506 s = splnet(); 507 error = in_pcbbind(inp, addr); 508 splx(s); 509 break; 510 511 case PRU_LISTEN: 512 error = EOPNOTSUPP; 513 break; 514 515 case PRU_CONNECT: 516 if (inp->inp_faddr.s_addr != INADDR_ANY) { 517 error = EISCONN; 518 break; 519 } 520 s = splnet(); 521 error = in_pcbconnect(inp, addr); 522 splx(s); 523 if (error == 0) 524 soisconnected(so); 525 break; 526 527 case PRU_CONNECT2: 528 error = EOPNOTSUPP; 529 break; 530 531 case PRU_ACCEPT: 532 error = EOPNOTSUPP; 533 break; 534 535 case PRU_DISCONNECT: 536 if (inp->inp_faddr.s_addr == INADDR_ANY) { 537 error = ENOTCONN; 538 break; 539 } 540 s = splnet(); 541 in_pcbdisconnect(inp); 542 inp->inp_laddr.s_addr = INADDR_ANY; 543 splx(s); 544 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 545 break; 546 547 case PRU_SHUTDOWN: 548 socantsendmore(so); 549 break; 550 551 case PRU_SEND: 552 return (udp_output(inp, m, addr, control)); 553 554 case PRU_ABORT: 555 soisdisconnected(so); 556 udp_detach(inp); 557 break; 558 559 case PRU_SOCKADDR: 560 in_setsockaddr(inp, addr); 561 break; 562 563 case PRU_PEERADDR: 564 in_setpeeraddr(inp, addr); 565 break; 566 567 case PRU_SENSE: 568 /* 569 * stat: don't bother with a blocksize. 570 */ 571 return (0); 572 573 case PRU_SENDOOB: 574 case PRU_FASTTIMO: 575 case PRU_SLOWTIMO: 576 case PRU_PROTORCV: 577 case PRU_PROTOSEND: 578 error = EOPNOTSUPP; 579 break; 580 581 case PRU_RCVD: 582 case PRU_RCVOOB: 583 return (EOPNOTSUPP); /* do not free mbuf's */ 584 585 default: 586 panic("udp_usrreq"); 587 } 588 589 release: 590 if (control) { 591 printf("udp control data unexpectedly retained\n"); 592 m_freem(control); 593 } 594 if (m) 595 m_freem(m); 596 return (error); 597 } 598 599 udp_detach(inp) 600 struct inpcb *inp; 601 { 602 int s = splnet(); 603 604 if (inp == udp_last_inpcb) 605 udp_last_inpcb = &udb; 606 in_pcbdetach(inp); 607 splx(s); 608 } 609
Indexes created Sun Sep 21 15:09:59 GMT 2025