udp_usrreq.c revision 1.12
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 1.12 1994/02/10 18:46:06 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 /* 58 * UDP protocol implementation. 59 * Per RFC 768, August, 1980. 60 */ 61 #ifndef COMPAT_42 62 int udpcksum = 1; 63 #else 64 int udpcksum = 0; /* XXX */ 65 #endif 66 int udp_ttl = UDP_TTL; 67 68 struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 69 struct inpcb *udp_last_inpcb = &udb; 70 71 static void udp_detach __P((struct inpcb *)); 72 static void udp_notify __P((struct inpcb *, int)); 73 static struct mbuf * 74 udp_saveopt __P((caddr_t, int, int)); 75 76 void 77 udp_init() 78 { 79 80 udb.inp_next = udb.inp_prev = &udb; 81 } 82 83 void 84 udp_input(m, iphlen) 85 register struct mbuf *m; 86 int iphlen; 87 { 88 register struct ip *ip; 89 register struct udphdr *uh; 90 register struct inpcb *inp; 91 struct mbuf *opts = 0; 92 int len; 93 struct ip save_ip; 94 95 udpstat.udps_ipackets++; 96 97 /* 98 * Strip IP options, if any; should skip this, 99 * make available to user, and use on returned packets, 100 * but we don't yet have a way to check the checksum 101 * with options still present. 102 */ 103 if (iphlen > sizeof (struct ip)) { 104 ip_stripoptions(m, (struct mbuf *)0); 105 iphlen = sizeof(struct ip); 106 } 107 108 /* 109 * Get IP and UDP header together in first mbuf. 110 */ 111 ip = mtod(m, struct ip *); 112 if (m->m_len < iphlen + sizeof(struct udphdr)) { 113 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 114 udpstat.udps_hdrops++; 115 return; 116 } 117 ip = mtod(m, struct ip *); 118 } 119 uh = (struct udphdr *)((caddr_t)ip + iphlen); 120 121 /* 122 * Make mbuf data length reflect UDP length. 123 * If not enough data to reflect UDP length, drop. 124 */ 125 len = ntohs((u_short)uh->uh_ulen); 126 if (ip->ip_len != len) { 127 if (len > ip->ip_len) { 128 udpstat.udps_badlen++; 129 goto bad; 130 } 131 m_adj(m, len - ip->ip_len); 132 /* ip->ip_len = len; */ 133 } 134 /* 135 * Save a copy of the IP header in case we want restore it 136 * for sending an ICMP error message in response. 137 */ 138 save_ip = *ip; 139 140 /* 141 * Checksum extended UDP header and data. 142 */ 143 if (udpcksum && uh->uh_sum) { 144 ((struct ipovly *)ip)->ih_next = 0; 145 ((struct ipovly *)ip)->ih_prev = 0; 146 ((struct ipovly *)ip)->ih_x1 = 0; 147 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 148 if (uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) { 149 udpstat.udps_badsum++; 150 m_freem(m); 151 return; 152 } 153 } 154 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 155 in_broadcast(ip->ip_dst)) { 156 struct socket *last; 157 /* 158 * Deliver a multicast or broadcast datagram to *all* sockets 159 * for which the local and remote addresses and ports match 160 * those of the incoming datagram. This allows more than 161 * one process to receive multi/broadcasts on the same port. 162 * (This really ought to be done for unicast datagrams as 163 * well, but that would cause problems with existing 164 * applications that open both address-specific sockets and 165 * a wildcard socket listening to the same port -- they would 166 * end up receiving duplicates of every unicast datagram. 167 * Those applications open the multiple sockets to overcome an 168 * inadequacy of the UDP socket interface, but for backwards 169 * compatibility we avoid the problem here rather than 170 * fixing the interface. Maybe 4.4BSD will remedy this?) 171 */ 172 /* 173 * Construct sockaddr format source address. 174 */ 175 udp_in.sin_port = uh->uh_sport; 176 udp_in.sin_addr = ip->ip_src; 177 m->m_len -= sizeof (struct udpiphdr); 178 m->m_data += sizeof (struct udpiphdr); 179 /* 180 * Locate pcb(s) for datagram. 181 * (Algorithm copied from raw_intr().) 182 */ 183 last = NULL; 184 for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) { 185 if (inp->inp_lport != uh->uh_dport) 186 continue; 187 if (inp->inp_laddr.s_addr != INADDR_ANY) { 188 if (inp->inp_laddr.s_addr != 189 ip->ip_dst.s_addr) 190 continue; 191 } 192 if (inp->inp_faddr.s_addr != INADDR_ANY) { 193 if (inp->inp_faddr.s_addr != 194 ip->ip_src.s_addr || 195 inp->inp_fport != uh->uh_sport) 196 continue; 197 } 198 199 if (last != NULL) { 200 struct mbuf *n; 201 202 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 203 if (sbappendaddr(&last->so_rcv, 204 (struct sockaddr *)&udp_in, 205 n, (struct mbuf *)0) == 0) 206 m_freem(n); 207 else 208 sorwakeup(last); 209 } 210 } 211 last = inp->inp_socket; 212 /* 213 * Don't look for additional matches if this one 214 * does not have the SO_REUSEADDR socket option set. 215 * This heuristic avoids searching through all pcbs 216 * in the common case of a non-shared port. It 217 * assumes that an application will never clear 218 * the SO_REUSEADDR option after setting it. 219 */ 220 if ((last->so_options & SO_REUSEADDR) == 0) 221 break; 222 } 223 224 if (last == NULL) { 225 /* 226 * No matching pcb found; discard datagram. 227 * (No need to send an ICMP Port Unreachable 228 * for a broadcast or multicast datgram.) 229 */ 230 goto bad; 231 } 232 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 233 m, (struct mbuf *)0) == 0) 234 goto bad; 235 sorwakeup(last); 236 return; 237 } 238 /* 239 * Locate pcb for datagram. 240 */ 241 inp = udp_last_inpcb; 242 if (inp->inp_lport != uh->uh_dport || 243 inp->inp_fport != uh->uh_sport || 244 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 245 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 246 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, 247 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 248 if (inp) 249 udp_last_inpcb = inp; 250 udpstat.udpps_pcbcachemiss++; 251 } 252 if (inp == 0) { 253 /* don't send ICMP response for broadcast packet */ 254 udpstat.udps_noport++; 255 *ip = save_ip; 256 ip->ip_len += iphlen; 257 { 258 register struct in_addr foo = {}; 259 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, foo); 260 } 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; 272 273 if (inp->inp_flags & INP_RECVDSTADDR) { 274 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 275 sizeof(struct in_addr), IP_RECVDSTADDR); 276 if (*mp) 277 mp = &(*mp)->m_next; 278 } 279 #ifdef notyet 280 /* options were tossed above */ 281 if (inp->inp_flags & INP_RECVOPTS) { 282 *mp = udp_saveopt((caddr_t) opts_deleted_above, 283 sizeof(struct in_addr), IP_RECVOPTS); 284 if (*mp) 285 mp = &(*mp)->m_next; 286 } 287 /* ip_srcroute doesn't do what we want here, need to fix */ 288 if (inp->inp_flags & INP_RECVRETOPTS) { 289 *mp = udp_saveopt((caddr_t) ip_srcroute(), 290 sizeof(struct in_addr), IP_RECVRETOPTS); 291 if (*mp) 292 mp = &(*mp)->m_next; 293 } 294 #endif 295 } 296 iphlen += sizeof(struct udphdr); 297 m->m_len -= iphlen; 298 m->m_pkthdr.len -= iphlen; 299 m->m_data += iphlen; 300 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 301 m, opts) == 0) { 302 udpstat.udps_fullsock++; 303 goto bad; 304 } 305 sorwakeup(inp->inp_socket); 306 return; 307 bad: 308 m_freem(m); 309 if (opts) 310 m_freem(opts); 311 } 312 313 /* 314 * Create a "control" mbuf containing the specified data 315 * with the specified type for presentation with a datagram. 316 */ 317 static struct mbuf * 318 udp_saveopt(p, size, type) 319 caddr_t p; 320 register int size; 321 int type; 322 { 323 register struct cmsghdr *cp; 324 struct mbuf *m; 325 326 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 327 return ((struct mbuf *) NULL); 328 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 329 bcopy(p, (caddr_t)(cp + 1), size); 330 size += sizeof(*cp); 331 m->m_len = size; 332 cp->cmsg_len = size; 333 cp->cmsg_level = IPPROTO_IP; 334 cp->cmsg_type = type; 335 return (m); 336 } 337 338 /* 339 * Notify a udp user of an asynchronous error; 340 * just wake up so that he can collect error status. 341 */ 342 static void 343 udp_notify(inp, errno) 344 register struct inpcb *inp; 345 int errno; 346 { 347 348 inp->inp_socket->so_error = errno; 349 sorwakeup(inp->inp_socket); 350 sowwakeup(inp->inp_socket); 351 } 352 353 void 354 udp_ctlinput(cmd, sa, ip) 355 int cmd; 356 struct sockaddr *sa; 357 register struct ip *ip; 358 { 359 register struct udphdr *uh; 360 extern struct in_addr zeroin_addr; 361 extern u_char inetctlerrmap[]; 362 363 if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 364 return; 365 if (ip) { 366 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 367 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 368 cmd, udp_notify); 369 } else 370 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 371 } 372 373 int 374 udp_output(inp, m, addr, control) 375 register struct inpcb *inp; 376 register struct mbuf *m; 377 struct mbuf *addr, *control; 378 { 379 register struct udpiphdr *ui; 380 register int len = m->m_pkthdr.len; 381 struct in_addr laddr; 382 int s, error = 0; 383 384 if (control) 385 m_freem(control); /* XXX */ 386 387 if (addr) { 388 laddr = inp->inp_laddr; 389 if (inp->inp_faddr.s_addr != INADDR_ANY) { 390 error = EISCONN; 391 goto release; 392 } 393 /* 394 * Must block input while temporarily connected. 395 */ 396 s = splnet(); 397 error = in_pcbconnect(inp, addr); 398 if (error) { 399 splx(s); 400 goto release; 401 } 402 } else { 403 if (inp->inp_faddr.s_addr == INADDR_ANY) { 404 error = ENOTCONN; 405 goto release; 406 } 407 } 408 /* 409 * Calculate data length and get a mbuf 410 * for UDP and IP headers. 411 */ 412 M_PREPEND(m, sizeof(struct udpiphdr), M_WAIT); 413 414 /* 415 * Fill in mbuf with extended UDP header 416 * and addresses and length put into network format. 417 */ 418 ui = mtod(m, struct udpiphdr *); 419 ui->ui_next = ui->ui_prev = 0; 420 ui->ui_x1 = 0; 421 ui->ui_pr = IPPROTO_UDP; 422 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 423 ui->ui_src = inp->inp_laddr; 424 ui->ui_dst = inp->inp_faddr; 425 ui->ui_sport = inp->inp_lport; 426 ui->ui_dport = inp->inp_fport; 427 ui->ui_ulen = ui->ui_len; 428 429 /* 430 * Stuff checksum and output datagram. 431 */ 432 ui->ui_sum = 0; 433 if (udpcksum) { 434 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 435 ui->ui_sum = 0xffff; 436 } 437 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 438 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 439 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 440 udpstat.udps_opackets++; 441 error = ip_output(m, inp->inp_options, &inp->inp_route, 442 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST), 443 inp->inp_moptions); 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 int 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 static void 600 udp_detach(inp) 601 struct inpcb *inp; 602 { 603 int s = splnet(); 604 605 if (inp == udp_last_inpcb) 606 udp_last_inpcb = &udb; 607 in_pcbdetach(inp); 608 splx(s); 609 } 610
Indexes created Mon Sep 22 05:09:51 GMT 2025