udp_usrreq.c revision 1.8
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 1.8 1994/01/08 23:19:48 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 #ifdef MULTICAST 155 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || 156 in_broadcast(ip->ip_dst)) { 157 struct socket *last; 158 /* 159 * Deliver a multicast or broadcast datagram to *all* sockets 160 * for which the local and remote addresses and ports match 161 * those of the incoming datagram. This allows more than 162 * one process to receive multi/broadcasts on the same port. 163 * (This really ought to be done for unicast datagrams as 164 * well, but that would cause problems with existing 165 * applications that open both address-specific sockets and 166 * a wildcard socket listening to the same port -- they would 167 * end up receiving duplicates of every unicast datagram. 168 * Those applications open the multiple sockets to overcome an 169 * inadequacy of the UDP socket interface, but for backwards 170 * compatibility we avoid the problem here rather than 171 * fixing the interface. Maybe 4.4BSD will remedy this?) 172 */ 173 /* 174 * Construct sockaddr format source address. 175 */ 176 udp_in.sin_port = uh->uh_sport; 177 udp_in.sin_addr = ip->ip_src; 178 m->m_len -= sizeof (struct udpiphdr); 179 m->m_data += sizeof (struct udpiphdr); 180 /* 181 * Locate pcb(s) for datagram. 182 * (Algorithm copied from raw_intr().) 183 */ 184 last = NULL; 185 for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) { 186 if (inp->inp_lport != uh->uh_dport) 187 continue; 188 if (inp->inp_laddr.s_addr != INADDR_ANY) { 189 if (inp->inp_laddr.s_addr != 190 ip->ip_dst.s_addr) 191 continue; 192 } 193 if (inp->inp_faddr.s_addr != INADDR_ANY) { 194 if (inp->inp_faddr.s_addr != 195 ip->ip_src.s_addr || 196 inp->inp_fport != uh->uh_sport) 197 continue; 198 } 199 200 if (last != NULL) { 201 struct mbuf *n; 202 203 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 204 if (sbappendaddr(&last->so_rcv, 205 (struct sockaddr *)&udp_in, 206 n, (struct mbuf *)0) == 0) 207 m_freem(n); 208 else 209 sorwakeup(last); 210 } 211 } 212 last = inp->inp_socket; 213 /* 214 * Don't look for additional matches if this one 215 * does not have the SO_REUSEADDR socket option set. 216 * This heuristic avoids searching through all pcbs 217 * in the common case of a non-shared port. It 218 * assumes that an application will never clear 219 * the SO_REUSEADDR option after setting it. 220 */ 221 if ((last->so_options & SO_REUSEADDR) == 0) 222 break; 223 } 224 225 if (last == NULL) { 226 /* 227 * No matching pcb found; discard datagram. 228 * (No need to send an ICMP Port Unreachable 229 * for a broadcast or multicast datgram.) 230 */ 231 goto bad; 232 } 233 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 234 m, (struct mbuf *)0) == 0) 235 goto bad; 236 sorwakeup(last); 237 return; 238 } 239 #endif 240 /* 241 * Locate pcb for datagram. 242 */ 243 inp = udp_last_inpcb; 244 if (inp->inp_lport != uh->uh_dport || 245 inp->inp_fport != uh->uh_sport || 246 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 247 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 248 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, 249 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 250 if (inp) 251 udp_last_inpcb = inp; 252 udpstat.udpps_pcbcachemiss++; 253 } 254 if (inp == 0) { 255 /* don't send ICMP response for broadcast packet */ 256 udpstat.udps_noport++; 257 #ifndef MULTICAST 258 /* XXX why don't we do this with MULTICAST? */ 259 if (m->m_flags & (M_BCAST | M_MCAST)) { 260 udpstat.udps_noportbcast++; 261 goto bad; 262 } 263 #endif 264 *ip = save_ip; 265 ip->ip_len += iphlen; 266 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT); 267 return; 268 } 269 270 /* 271 * Construct sockaddr format source address. 272 * Stuff source address and datagram in user buffer. 273 */ 274 udp_in.sin_port = uh->uh_sport; 275 udp_in.sin_addr = ip->ip_src; 276 if (inp->inp_flags & INP_CONTROLOPTS) { 277 struct mbuf **mp = &opts; 278 279 if (inp->inp_flags & INP_RECVDSTADDR) { 280 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 281 sizeof(struct in_addr), IP_RECVDSTADDR); 282 if (*mp) 283 mp = &(*mp)->m_next; 284 } 285 #ifdef notyet 286 /* options were tossed above */ 287 if (inp->inp_flags & INP_RECVOPTS) { 288 *mp = udp_saveopt((caddr_t) opts_deleted_above, 289 sizeof(struct in_addr), IP_RECVOPTS); 290 if (*mp) 291 mp = &(*mp)->m_next; 292 } 293 /* ip_srcroute doesn't do what we want here, need to fix */ 294 if (inp->inp_flags & INP_RECVRETOPTS) { 295 *mp = udp_saveopt((caddr_t) ip_srcroute(), 296 sizeof(struct in_addr), IP_RECVRETOPTS); 297 if (*mp) 298 mp = &(*mp)->m_next; 299 } 300 #endif 301 } 302 iphlen += sizeof(struct udphdr); 303 m->m_len -= iphlen; 304 m->m_pkthdr.len -= iphlen; 305 m->m_data += iphlen; 306 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 307 m, opts) == 0) { 308 udpstat.udps_fullsock++; 309 goto bad; 310 } 311 sorwakeup(inp->inp_socket); 312 return; 313 bad: 314 m_freem(m); 315 if (opts) 316 m_freem(opts); 317 } 318 319 /* 320 * Create a "control" mbuf containing the specified data 321 * with the specified type for presentation with a datagram. 322 */ 323 static struct mbuf * 324 udp_saveopt(p, size, type) 325 caddr_t p; 326 register int size; 327 int type; 328 { 329 register struct cmsghdr *cp; 330 struct mbuf *m; 331 332 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 333 return ((struct mbuf *) NULL); 334 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 335 bcopy(p, (caddr_t)(cp + 1), size); 336 size += sizeof(*cp); 337 m->m_len = size; 338 cp->cmsg_len = size; 339 cp->cmsg_level = IPPROTO_IP; 340 cp->cmsg_type = type; 341 return (m); 342 } 343 344 /* 345 * Notify a udp user of an asynchronous error; 346 * just wake up so that he can collect error status. 347 */ 348 static void 349 udp_notify(inp, errno) 350 register struct inpcb *inp; 351 int errno; 352 { 353 354 inp->inp_socket->so_error = errno; 355 sorwakeup(inp->inp_socket); 356 sowwakeup(inp->inp_socket); 357 } 358 359 void 360 udp_ctlinput(cmd, sa, ip) 361 int cmd; 362 struct sockaddr *sa; 363 register struct ip *ip; 364 { 365 register struct udphdr *uh; 366 extern struct in_addr zeroin_addr; 367 extern u_char inetctlerrmap[]; 368 369 if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 370 return; 371 if (ip) { 372 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 373 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 374 cmd, udp_notify); 375 } else 376 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 377 } 378 379 int 380 udp_output(inp, m, addr, control) 381 register struct inpcb *inp; 382 register struct mbuf *m; 383 struct mbuf *addr, *control; 384 { 385 register struct udpiphdr *ui; 386 register int len = m->m_pkthdr.len; 387 struct in_addr laddr; 388 int s, error = 0; 389 390 if (control) 391 m_freem(control); /* XXX */ 392 393 if (addr) { 394 laddr = inp->inp_laddr; 395 if (inp->inp_faddr.s_addr != INADDR_ANY) { 396 error = EISCONN; 397 goto release; 398 } 399 /* 400 * Must block input while temporarily connected. 401 */ 402 s = splnet(); 403 error = in_pcbconnect(inp, addr); 404 if (error) { 405 splx(s); 406 goto release; 407 } 408 } else { 409 if (inp->inp_faddr.s_addr == INADDR_ANY) { 410 error = ENOTCONN; 411 goto release; 412 } 413 } 414 /* 415 * Calculate data length and get a mbuf 416 * for UDP and IP headers. 417 */ 418 M_PREPEND(m, sizeof(struct udpiphdr), M_WAIT); 419 420 /* 421 * Fill in mbuf with extended UDP header 422 * and addresses and length put into network format. 423 */ 424 ui = mtod(m, struct udpiphdr *); 425 ui->ui_next = ui->ui_prev = 0; 426 ui->ui_x1 = 0; 427 ui->ui_pr = IPPROTO_UDP; 428 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 429 ui->ui_src = inp->inp_laddr; 430 ui->ui_dst = inp->inp_faddr; 431 ui->ui_sport = inp->inp_lport; 432 ui->ui_dport = inp->inp_fport; 433 ui->ui_ulen = ui->ui_len; 434 435 /* 436 * Stuff checksum and output datagram. 437 */ 438 ui->ui_sum = 0; 439 if (udpcksum) { 440 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 441 ui->ui_sum = 0xffff; 442 } 443 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 444 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 445 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 446 udpstat.udps_opackets++; 447 error = ip_output(m, inp->inp_options, &inp->inp_route, 448 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST) 449 #ifdef MULTICAST 450 | IP_MULTICASTOPTS, inp->inp_moptions 451 #endif 452 ); 453 454 if (addr) { 455 in_pcbdisconnect(inp); 456 inp->inp_laddr = laddr; 457 splx(s); 458 } 459 return (error); 460 461 release: 462 m_freem(m); 463 return (error); 464 } 465 466 u_long udp_sendspace = 9216; /* really max datagram size */ 467 u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 468 /* 40 1K datagrams */ 469 470 /*ARGSUSED*/ 471 int 472 udp_usrreq(so, req, m, addr, control) 473 struct socket *so; 474 int req; 475 struct mbuf *m, *addr, *control; 476 { 477 struct inpcb *inp = sotoinpcb(so); 478 int error = 0; 479 int s; 480 481 if (req == PRU_CONTROL) 482 return (in_control(so, (int)m, (caddr_t)addr, 483 (struct ifnet *)control)); 484 if (inp == NULL && req != PRU_ATTACH) { 485 error = EINVAL; 486 goto release; 487 } 488 /* 489 * Note: need to block udp_input while changing 490 * the udp pcb queue and/or pcb addresses. 491 */ 492 switch (req) { 493 494 case PRU_ATTACH: 495 if (inp != NULL) { 496 error = EINVAL; 497 break; 498 } 499 s = splnet(); 500 error = in_pcballoc(so, &udb); 501 splx(s); 502 if (error) 503 break; 504 error = soreserve(so, udp_sendspace, udp_recvspace); 505 if (error) 506 break; 507 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = udp_ttl; 508 break; 509 510 case PRU_DETACH: 511 udp_detach(inp); 512 break; 513 514 case PRU_BIND: 515 s = splnet(); 516 error = in_pcbbind(inp, addr); 517 splx(s); 518 break; 519 520 case PRU_LISTEN: 521 error = EOPNOTSUPP; 522 break; 523 524 case PRU_CONNECT: 525 if (inp->inp_faddr.s_addr != INADDR_ANY) { 526 error = EISCONN; 527 break; 528 } 529 s = splnet(); 530 error = in_pcbconnect(inp, addr); 531 splx(s); 532 if (error == 0) 533 soisconnected(so); 534 break; 535 536 case PRU_CONNECT2: 537 error = EOPNOTSUPP; 538 break; 539 540 case PRU_ACCEPT: 541 error = EOPNOTSUPP; 542 break; 543 544 case PRU_DISCONNECT: 545 if (inp->inp_faddr.s_addr == INADDR_ANY) { 546 error = ENOTCONN; 547 break; 548 } 549 s = splnet(); 550 in_pcbdisconnect(inp); 551 inp->inp_laddr.s_addr = INADDR_ANY; 552 splx(s); 553 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 554 break; 555 556 case PRU_SHUTDOWN: 557 socantsendmore(so); 558 break; 559 560 case PRU_SEND: 561 return (udp_output(inp, m, addr, control)); 562 563 case PRU_ABORT: 564 soisdisconnected(so); 565 udp_detach(inp); 566 break; 567 568 case PRU_SOCKADDR: 569 in_setsockaddr(inp, addr); 570 break; 571 572 case PRU_PEERADDR: 573 in_setpeeraddr(inp, addr); 574 break; 575 576 case PRU_SENSE: 577 /* 578 * stat: don't bother with a blocksize. 579 */ 580 return (0); 581 582 case PRU_SENDOOB: 583 case PRU_FASTTIMO: 584 case PRU_SLOWTIMO: 585 case PRU_PROTORCV: 586 case PRU_PROTOSEND: 587 error = EOPNOTSUPP; 588 break; 589 590 case PRU_RCVD: 591 case PRU_RCVOOB: 592 return (EOPNOTSUPP); /* do not free mbuf's */ 593 594 default: 595 panic("udp_usrreq"); 596 } 597 598 release: 599 if (control) { 600 printf("udp control data unexpectedly retained\n"); 601 m_freem(control); 602 } 603 if (m) 604 m_freem(m); 605 return (error); 606 } 607 608 static void 609 udp_detach(inp) 610 struct inpcb *inp; 611 { 612 int s = splnet(); 613 614 if (inp == udp_last_inpcb) 615 udp_last_inpcb = &udb; 616 in_pcbdetach(inp); 617 splx(s); 618 } 619
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