udp_usrreq.c revision 1.7
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 1.7 1994/01/08 23:17:18 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 static void udp_detach __P((struct inpcb *)); 60 static void udp_notify __P((struct inpcb *, int)); 61 static struct mbuf * 62 udp_saveopt __P((caddr_t, int, int)); 63 64 /* 65 * UDP protocol implementation. 66 * Per RFC 768, August, 1980. 67 */ 68 void 69 udp_init() 70 { 71 72 udb.inp_next = udb.inp_prev = &udb; 73 } 74 75 #ifndef COMPAT_42 76 int udpcksum = 1; 77 #else 78 int udpcksum = 0; /* XXX */ 79 #endif 80 int udp_ttl = UDP_TTL; 81 82 struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 83 84 void 85 udp_input(m, iphlen) 86 register struct mbuf *m; 87 int iphlen; 88 { 89 register struct ip *ip; 90 register struct udphdr *uh; 91 register struct inpcb *inp; 92 struct mbuf *opts = 0; 93 int len; 94 struct ip save_ip; 95 96 udpstat.udps_ipackets++; 97 98 /* 99 * Strip IP options, if any; should skip this, 100 * make available to user, and use on returned packets, 101 * but we don't yet have a way to check the checksum 102 * with options still present. 103 */ 104 if (iphlen > sizeof (struct ip)) { 105 ip_stripoptions(m, (struct mbuf *)0); 106 iphlen = sizeof(struct ip); 107 } 108 109 /* 110 * Get IP and UDP header together in first mbuf. 111 */ 112 ip = mtod(m, struct ip *); 113 if (m->m_len < iphlen + sizeof(struct udphdr)) { 114 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 115 udpstat.udps_hdrops++; 116 return; 117 } 118 ip = mtod(m, struct ip *); 119 } 120 uh = (struct udphdr *)((caddr_t)ip + iphlen); 121 122 /* 123 * Make mbuf data length reflect UDP length. 124 * If not enough data to reflect UDP length, drop. 125 */ 126 len = ntohs((u_short)uh->uh_ulen); 127 if (ip->ip_len != len) { 128 if (len > ip->ip_len) { 129 udpstat.udps_badlen++; 130 goto bad; 131 } 132 m_adj(m, len - ip->ip_len); 133 /* ip->ip_len = len; */ 134 } 135 /* 136 * Save a copy of the IP header in case we want restore it 137 * for sending an ICMP error message in response. 138 */ 139 save_ip = *ip; 140 141 /* 142 * Checksum extended UDP header and data. 143 */ 144 if (udpcksum && uh->uh_sum) { 145 ((struct ipovly *)ip)->ih_next = 0; 146 ((struct ipovly *)ip)->ih_prev = 0; 147 ((struct ipovly *)ip)->ih_x1 = 0; 148 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 149 if (uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) { 150 udpstat.udps_badsum++; 151 m_freem(m); 152 return; 153 } 154 } 155 #ifdef MULTICAST 156 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 157 in_broadcast(ip->ip_dst)) { 158 struct socket *last; 159 /* 160 * Deliver a multicast or broadcast datagram to *all* sockets 161 * for which the local and remote addresses and ports match 162 * those of the incoming datagram. This allows more than 163 * one process to receive multi/broadcasts on the same port. 164 * (This really ought to be done for unicast datagrams as 165 * well, but that would cause problems with existing 166 * applications that open both address-specific sockets and 167 * a wildcard socket listening to the same port -- they would 168 * end up receiving duplicates of every unicast datagram. 169 * Those applications open the multiple sockets to overcome an 170 * inadequacy of the UDP socket interface, but for backwards 171 * compatibility we avoid the problem here rather than 172 * fixing the interface. Maybe 4.4BSD will remedy this?) 173 */ 174 /* 175 * Construct sockaddr format source address. 176 */ 177 udp_in.sin_port = uh->uh_sport; 178 udp_in.sin_addr = ip->ip_src; 179 m->m_len -= sizeof (struct udpiphdr); 180 m->m_data += sizeof (struct udpiphdr); 181 /* 182 * Locate pcb(s) for datagram. 183 * (Algorithm copied from raw_intr().) 184 */ 185 last = NULL; 186 for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) { 187 if (inp->inp_lport != uh->uh_dport) 188 continue; 189 if (inp->inp_laddr.s_addr != INADDR_ANY) { 190 if (inp->inp_laddr.s_addr != 191 ip->ip_dst.s_addr) 192 continue; 193 } 194 if (inp->inp_faddr.s_addr != INADDR_ANY) { 195 if (inp->inp_faddr.s_addr != 196 ip->ip_src.s_addr || 197 inp->inp_fport != uh->uh_sport) 198 continue; 199 } 200 201 if (last != NULL) { 202 struct mbuf *n; 203 204 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 205 if (sbappendaddr(&last->so_rcv, 206 (struct sockaddr *)&udp_in, 207 n, (struct mbuf *)0) == 0) 208 m_freem(n); 209 else 210 sorwakeup(last); 211 } 212 } 213 last = inp->inp_socket; 214 /* 215 * Don't look for additional matches if this one 216 * does not have the SO_REUSEADDR socket option set. 217 * This heuristic avoids searching through all pcbs 218 * in the common case of a non-shared port. It 219 * assumes that an application will never clear 220 * the SO_REUSEADDR option after setting it. 221 */ 222 if ((last->so_options & SO_REUSEADDR) == 0) 223 break; 224 } 225 226 if (last == NULL) { 227 /* 228 * No matching pcb found; discard datagram. 229 * (No need to send an ICMP Port Unreachable 230 * for a broadcast or multicast datgram.) 231 */ 232 goto bad; 233 } 234 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 235 m, (struct mbuf *)0) == 0) 236 goto bad; 237 sorwakeup(last); 238 return; 239 } 240 #endif 241 /* 242 * Locate pcb for datagram. 243 */ 244 inp = udp_last_inpcb; 245 if (inp->inp_lport != uh->uh_dport || 246 inp->inp_fport != uh->uh_sport || 247 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 248 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 249 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, 250 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 251 if (inp) 252 udp_last_inpcb = inp; 253 udpstat.udpps_pcbcachemiss++; 254 } 255 if (inp == 0) { 256 /* don't send ICMP response for broadcast packet */ 257 udpstat.udps_noport++; 258 #ifndef MULTICAST 259 /* XXX why don't we do this with MULTICAST? */ 260 if (m->m_flags & (M_BCAST | M_MCAST)) { 261 udpstat.udps_noportbcast++; 262 goto bad; 263 } 264 #endif 265 *ip = save_ip; 266 ip->ip_len += iphlen; 267 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT); 268 return; 269 } 270 271 /* 272 * Construct sockaddr format source address. 273 * Stuff source address and datagram in user buffer. 274 */ 275 udp_in.sin_port = uh->uh_sport; 276 udp_in.sin_addr = ip->ip_src; 277 if (inp->inp_flags & INP_CONTROLOPTS) { 278 struct mbuf **mp = &opts; 279 280 if (inp->inp_flags & INP_RECVDSTADDR) { 281 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 282 sizeof(struct in_addr), IP_RECVDSTADDR); 283 if (*mp) 284 mp = &(*mp)->m_next; 285 } 286 #ifdef notyet 287 /* options were tossed above */ 288 if (inp->inp_flags & INP_RECVOPTS) { 289 *mp = udp_saveopt((caddr_t) opts_deleted_above, 290 sizeof(struct in_addr), IP_RECVOPTS); 291 if (*mp) 292 mp = &(*mp)->m_next; 293 } 294 /* ip_srcroute doesn't do what we want here, need to fix */ 295 if (inp->inp_flags & INP_RECVRETOPTS) { 296 *mp = udp_saveopt((caddr_t) ip_srcroute(), 297 sizeof(struct in_addr), IP_RECVRETOPTS); 298 if (*mp) 299 mp = &(*mp)->m_next; 300 } 301 #endif 302 } 303 iphlen += sizeof(struct udphdr); 304 m->m_len -= iphlen; 305 m->m_pkthdr.len -= iphlen; 306 m->m_data += iphlen; 307 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 308 m, opts) == 0) { 309 udpstat.udps_fullsock++; 310 goto bad; 311 } 312 sorwakeup(inp->inp_socket); 313 return; 314 bad: 315 m_freem(m); 316 if (opts) 317 m_freem(opts); 318 } 319 320 /* 321 * Create a "control" mbuf containing the specified data 322 * with the specified type for presentation with a datagram. 323 */ 324 static struct mbuf * 325 udp_saveopt(p, size, type) 326 caddr_t p; 327 register int size; 328 int type; 329 { 330 register struct cmsghdr *cp; 331 struct mbuf *m; 332 333 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 334 return ((struct mbuf *) NULL); 335 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 336 bcopy(p, (caddr_t)(cp + 1), size); 337 size += sizeof(*cp); 338 m->m_len = size; 339 cp->cmsg_len = size; 340 cp->cmsg_level = IPPROTO_IP; 341 cp->cmsg_type = type; 342 return (m); 343 } 344 345 /* 346 * Notify a udp user of an asynchronous error; 347 * just wake up so that he can collect error status. 348 */ 349 static void 350 udp_notify(inp, errno) 351 register struct inpcb *inp; 352 int errno; 353 { 354 355 inp->inp_socket->so_error = errno; 356 sorwakeup(inp->inp_socket); 357 sowwakeup(inp->inp_socket); 358 } 359 360 void 361 udp_ctlinput(cmd, sa, ip) 362 int cmd; 363 struct sockaddr *sa; 364 register struct ip *ip; 365 { 366 register struct udphdr *uh; 367 extern struct in_addr zeroin_addr; 368 extern u_char inetctlerrmap[]; 369 370 if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 371 return; 372 if (ip) { 373 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 374 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 375 cmd, udp_notify); 376 } else 377 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 378 } 379 380 int 381 udp_output(inp, m, addr, control) 382 register struct inpcb *inp; 383 register struct mbuf *m; 384 struct mbuf *addr, *control; 385 { 386 register struct udpiphdr *ui; 387 register int len = m->m_pkthdr.len; 388 struct in_addr laddr; 389 int s, error = 0; 390 391 if (control) 392 m_freem(control); /* XXX */ 393 394 if (addr) { 395 laddr = inp->inp_laddr; 396 if (inp->inp_faddr.s_addr != INADDR_ANY) { 397 error = EISCONN; 398 goto release; 399 } 400 /* 401 * Must block input while temporarily connected. 402 */ 403 s = splnet(); 404 error = in_pcbconnect(inp, addr); 405 if (error) { 406 splx(s); 407 goto release; 408 } 409 } else { 410 if (inp->inp_faddr.s_addr == INADDR_ANY) { 411 error = ENOTCONN; 412 goto release; 413 } 414 } 415 /* 416 * Calculate data length and get a mbuf 417 * for UDP and IP headers. 418 */ 419 M_PREPEND(m, sizeof(struct udpiphdr), M_WAIT); 420 421 /* 422 * Fill in mbuf with extended UDP header 423 * and addresses and length put into network format. 424 */ 425 ui = mtod(m, struct udpiphdr *); 426 ui->ui_next = ui->ui_prev = 0; 427 ui->ui_x1 = 0; 428 ui->ui_pr = IPPROTO_UDP; 429 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 430 ui->ui_src = inp->inp_laddr; 431 ui->ui_dst = inp->inp_faddr; 432 ui->ui_sport = inp->inp_lport; 433 ui->ui_dport = inp->inp_fport; 434 ui->ui_ulen = ui->ui_len; 435 436 /* 437 * Stuff checksum and output datagram. 438 */ 439 ui->ui_sum = 0; 440 if (udpcksum) { 441 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 442 ui->ui_sum = 0xffff; 443 } 444 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 445 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 446 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 447 udpstat.udps_opackets++; 448 error = ip_output(m, inp->inp_options, &inp->inp_route, 449 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST) 450 #ifdef MULTICAST 451 | IP_MULTICASTOPTS, inp->inp_moptions 452 #endif 453 ); 454 455 if (addr) { 456 in_pcbdisconnect(inp); 457 inp->inp_laddr = laddr; 458 splx(s); 459 } 460 return (error); 461 462 release: 463 m_freem(m); 464 return (error); 465 } 466 467 u_long udp_sendspace = 9216; /* really max datagram size */ 468 u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 469 /* 40 1K datagrams */ 470 471 /*ARGSUSED*/ 472 int 473 udp_usrreq(so, req, m, addr, control) 474 struct socket *so; 475 int req; 476 struct mbuf *m, *addr, *control; 477 { 478 struct inpcb *inp = sotoinpcb(so); 479 int error = 0; 480 int s; 481 482 if (req == PRU_CONTROL) 483 return (in_control(so, (int)m, (caddr_t)addr, 484 (struct ifnet *)control)); 485 if (inp == NULL && req != PRU_ATTACH) { 486 error = EINVAL; 487 goto release; 488 } 489 /* 490 * Note: need to block udp_input while changing 491 * the udp pcb queue and/or pcb addresses. 492 */ 493 switch (req) { 494 495 case PRU_ATTACH: 496 if (inp != NULL) { 497 error = EINVAL; 498 break; 499 } 500 s = splnet(); 501 error = in_pcballoc(so, &udb); 502 splx(s); 503 if (error) 504 break; 505 error = soreserve(so, udp_sendspace, udp_recvspace); 506 if (error) 507 break; 508 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = udp_ttl; 509 break; 510 511 case PRU_DETACH: 512 udp_detach(inp); 513 break; 514 515 case PRU_BIND: 516 s = splnet(); 517 error = in_pcbbind(inp, addr); 518 splx(s); 519 break; 520 521 case PRU_LISTEN: 522 error = EOPNOTSUPP; 523 break; 524 525 case PRU_CONNECT: 526 if (inp->inp_faddr.s_addr != INADDR_ANY) { 527 error = EISCONN; 528 break; 529 } 530 s = splnet(); 531 error = in_pcbconnect(inp, addr); 532 splx(s); 533 if (error == 0) 534 soisconnected(so); 535 break; 536 537 case PRU_CONNECT2: 538 error = EOPNOTSUPP; 539 break; 540 541 case PRU_ACCEPT: 542 error = EOPNOTSUPP; 543 break; 544 545 case PRU_DISCONNECT: 546 if (inp->inp_faddr.s_addr == INADDR_ANY) { 547 error = ENOTCONN; 548 break; 549 } 550 s = splnet(); 551 in_pcbdisconnect(inp); 552 inp->inp_laddr.s_addr = INADDR_ANY; 553 splx(s); 554 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 555 break; 556 557 case PRU_SHUTDOWN: 558 socantsendmore(so); 559 break; 560 561 case PRU_SEND: 562 return (udp_output(inp, m, addr, control)); 563 564 case PRU_ABORT: 565 soisdisconnected(so); 566 udp_detach(inp); 567 break; 568 569 case PRU_SOCKADDR: 570 in_setsockaddr(inp, addr); 571 break; 572 573 case PRU_PEERADDR: 574 in_setpeeraddr(inp, addr); 575 break; 576 577 case PRU_SENSE: 578 /* 579 * stat: don't bother with a blocksize. 580 */ 581 return (0); 582 583 case PRU_SENDOOB: 584 case PRU_FASTTIMO: 585 case PRU_SLOWTIMO: 586 case PRU_PROTORCV: 587 case PRU_PROTOSEND: 588 error = EOPNOTSUPP; 589 break; 590 591 case PRU_RCVD: 592 case PRU_RCVOOB: 593 return (EOPNOTSUPP); /* do not free mbuf's */ 594 595 default: 596 panic("udp_usrreq"); 597 } 598 599 release: 600 if (control) { 601 printf("udp control data unexpectedly retained\n"); 602 m_freem(control); 603 } 604 if (m) 605 m_freem(m); 606 return (error); 607 } 608 609 static void 610 udp_detach(inp) 611 struct inpcb *inp; 612 { 613 int s = splnet(); 614 615 if (inp == udp_last_inpcb) 616 udp_last_inpcb = &udb; 617 in_pcbdetach(inp); 618 splx(s); 619 } 620
Indexes created Mon Sep 22 10:09:38 GMT 2025