udp_usrreq.c revision 1.19
1 /* $NetBSD: udp_usrreq.c,v 1.19 1995/06/12 06:24:22 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94 36 */ 37 38 #include <sys/param.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/protosw.h> 42 #include <sys/socket.h> 43 #include <sys/socketvar.h> 44 #include <sys/errno.h> 45 #include <sys/stat.h> 46 47 #include <net/if.h> 48 #include <net/route.h> 49 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #include <netinet/in_var.h> 53 #include <netinet/ip.h> 54 #include <netinet/in_pcb.h> 55 #include <netinet/ip_var.h> 56 #include <netinet/ip_icmp.h> 57 #include <netinet/udp.h> 58 #include <netinet/udp_var.h> 59 60 /* 61 * UDP protocol implementation. 62 * Per RFC 768, August, 1980. 63 */ 64 #ifndef COMPAT_42 65 int udpcksum = 1; 66 #else 67 int udpcksum = 0; /* XXX */ 68 #endif 69 70 struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 71 struct inpcb *udp_last_inpcb = 0; 72 73 static void udp_detach __P((struct inpcb *)); 74 static void udp_notify __P((struct inpcb *, int)); 75 static struct mbuf *udp_saveopt __P((caddr_t, int, int)); 76 77 void 78 udp_init() 79 { 80 81 in_pcbinit(&udbtable); 82 } 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_int16_t)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 } 155 156 if (IN_MULTICAST(ip->ip_dst.s_addr) || 157 in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { 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 4.5BSD will remedy this?) 173 */ 174 175 /* 176 * Construct sockaddr format source address. 177 */ 178 udp_in.sin_port = uh->uh_sport; 179 udp_in.sin_addr = ip->ip_src; 180 m->m_len -= sizeof (struct udpiphdr); 181 m->m_data += sizeof (struct udpiphdr); 182 /* 183 * Locate pcb(s) for datagram. 184 * (Algorithm copied from raw_intr().) 185 */ 186 last = NULL; 187 for (inp = udbtable.inpt_list.lh_first; inp != 0; 188 inp = inp->inp_list.le_next) { 189 if (inp->inp_lport != uh->uh_dport) 190 continue; 191 if (inp->inp_laddr.s_addr != INADDR_ANY) { 192 if (inp->inp_laddr.s_addr != 193 ip->ip_dst.s_addr) 194 continue; 195 } 196 if (inp->inp_faddr.s_addr != INADDR_ANY) { 197 if (inp->inp_faddr.s_addr != 198 ip->ip_src.s_addr || 199 inp->inp_fport != uh->uh_sport) 200 continue; 201 } 202 203 if (last != NULL) { 204 struct mbuf *n; 205 206 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 207 if (sbappendaddr(&last->so_rcv, 208 sintosa(&udp_in), n, 209 (struct mbuf *)0) == 0) { 210 m_freem(n); 211 udpstat.udps_fullsock++; 212 } else 213 sorwakeup(last); 214 } 215 } 216 last = inp->inp_socket; 217 /* 218 * Don't look for additional matches if this one does 219 * not have either the SO_REUSEPORT or SO_REUSEADDR 220 * socket options set. This heuristic avoids searching 221 * through all pcbs in the common case of a non-shared 222 * port. It * assumes that an application will never 223 * clear these options after setting them. 224 */ 225 if ((last->so_options&(SO_REUSEPORT|SO_REUSEADDR) == 0)) 226 break; 227 } 228 229 if (last == NULL) { 230 /* 231 * No matching pcb found; discard datagram. 232 * (No need to send an ICMP Port Unreachable 233 * for a broadcast or multicast datgram.) 234 */ 235 udpstat.udps_noportbcast++; 236 goto bad; 237 } 238 if (sbappendaddr(&last->so_rcv, sintosa(&udp_in), m, 239 (struct mbuf *)0) == 0) { 240 udpstat.udps_fullsock++; 241 goto bad; 242 } 243 sorwakeup(last); 244 return; 245 } 246 /* 247 * Locate pcb for datagram. 248 */ 249 inp = udp_last_inpcb; 250 if (inp == 0 || 251 inp->inp_lport != uh->uh_dport || 252 inp->inp_fport != uh->uh_sport || 253 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 254 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 255 udpstat.udpps_pcbcachemiss++; 256 inp = in_pcblookup(&udbtable, ip->ip_src, uh->uh_sport, 257 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 258 if (inp == 0) { 259 udpstat.udps_noport++; 260 if (m->m_flags & (M_BCAST | M_MCAST)) { 261 udpstat.udps_noportbcast++; 262 goto bad; 263 } 264 *ip = save_ip; 265 ip->ip_len += iphlen; 266 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); 267 return; 268 } 269 udp_last_inpcb = inp; 270 } 271 272 /* 273 * Construct sockaddr format source address. 274 * Stuff source address and datagram in user buffer. 275 */ 276 udp_in.sin_port = uh->uh_sport; 277 udp_in.sin_addr = ip->ip_src; 278 if (inp->inp_flags & INP_CONTROLOPTS) { 279 struct mbuf **mp = &opts; 280 281 if (inp->inp_flags & INP_RECVDSTADDR) { 282 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 283 sizeof(struct in_addr), IP_RECVDSTADDR); 284 if (*mp) 285 mp = &(*mp)->m_next; 286 } 287 #ifdef notyet 288 /* options were tossed above */ 289 if (inp->inp_flags & INP_RECVOPTS) { 290 *mp = udp_saveopt((caddr_t) opts_deleted_above, 291 sizeof(struct in_addr), IP_RECVOPTS); 292 if (*mp) 293 mp = &(*mp)->m_next; 294 } 295 /* ip_srcroute doesn't do what we want here, need to fix */ 296 if (inp->inp_flags & INP_RECVRETOPTS) { 297 *mp = udp_saveopt((caddr_t) ip_srcroute(), 298 sizeof(struct in_addr), IP_RECVRETOPTS); 299 if (*mp) 300 mp = &(*mp)->m_next; 301 } 302 #endif 303 } 304 iphlen += sizeof(struct udphdr); 305 m->m_len -= iphlen; 306 m->m_pkthdr.len -= iphlen; 307 m->m_data += iphlen; 308 if (sbappendaddr(&inp->inp_socket->so_rcv, sintosa(&udp_in), m, 309 opts) == 0) { 310 udpstat.udps_fullsock++; 311 goto bad; 312 } 313 sorwakeup(inp->inp_socket); 314 return; 315 bad: 316 m_freem(m); 317 if (opts) 318 m_freem(opts); 319 } 320 321 /* 322 * Create a "control" mbuf containing the specified data 323 * with the specified type for presentation with a datagram. 324 */ 325 struct mbuf * 326 udp_saveopt(p, size, type) 327 caddr_t p; 328 register int size; 329 int type; 330 { 331 register struct cmsghdr *cp; 332 struct mbuf *m; 333 334 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 335 return ((struct mbuf *) NULL); 336 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 337 bcopy(p, CMSG_DATA(cp), size); 338 size += sizeof(*cp); 339 m->m_len = size; 340 cp->cmsg_len = size; 341 cp->cmsg_level = IPPROTO_IP; 342 cp->cmsg_type = type; 343 return (m); 344 } 345 346 /* 347 * Notify a udp user of an asynchronous error; 348 * just wake up so that he can collect error status. 349 */ 350 static void 351 udp_notify(inp, errno) 352 register struct inpcb *inp; 353 int errno; 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 void (*notify) __P((struct inpcb *, int)) = udp_notify; 370 371 if (PRC_IS_REDIRECT(cmd)) 372 notify = in_rtchange, ip = 0; 373 else if (cmd == PRC_HOSTDEAD) 374 ip = 0; 375 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 376 return; 377 if (ip) { 378 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 379 in_pcbnotify(&udbtable, sa, uh->uh_dport, ip->ip_src, 380 uh->uh_sport, cmd, notify); 381 } else 382 in_pcbnotifyall(&udbtable, sa, cmd, notify); 383 } 384 385 int 386 udp_output(inp, m, addr, control) 387 register struct inpcb *inp; 388 register struct mbuf *m; 389 struct mbuf *addr, *control; 390 { 391 register struct udpiphdr *ui; 392 register int len = m->m_pkthdr.len; 393 struct in_addr laddr; 394 int s, error = 0; 395 396 if (control) 397 m_freem(control); /* XXX */ 398 399 if (addr) { 400 laddr = inp->inp_laddr; 401 if (inp->inp_faddr.s_addr != INADDR_ANY) { 402 error = EISCONN; 403 goto release; 404 } 405 /* 406 * Must block input while temporarily connected. 407 */ 408 s = splnet(); 409 error = in_pcbconnect(inp, addr); 410 if (error) { 411 splx(s); 412 goto release; 413 } 414 } else { 415 if (inp->inp_faddr.s_addr == INADDR_ANY) { 416 error = ENOTCONN; 417 goto release; 418 } 419 } 420 /* 421 * Calculate data length and get a mbuf 422 * for UDP and IP headers. 423 */ 424 M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT); 425 if (m == 0) { 426 error = ENOBUFS; 427 goto release; 428 } 429 430 /* 431 * Fill in mbuf with extended UDP header 432 * and addresses and length put into network format. 433 */ 434 ui = mtod(m, struct udpiphdr *); 435 ui->ui_next = ui->ui_prev = 0; 436 ui->ui_x1 = 0; 437 ui->ui_pr = IPPROTO_UDP; 438 ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr)); 439 ui->ui_src = inp->inp_laddr; 440 ui->ui_dst = inp->inp_faddr; 441 ui->ui_sport = inp->inp_lport; 442 ui->ui_dport = inp->inp_fport; 443 ui->ui_ulen = ui->ui_len; 444 445 /* 446 * Stuff checksum and output datagram. 447 */ 448 ui->ui_sum = 0; 449 if (udpcksum) { 450 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 451 ui->ui_sum = 0xffff; 452 } 453 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 454 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 455 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 456 udpstat.udps_opackets++; 457 error = ip_output(m, inp->inp_options, &inp->inp_route, 458 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST), 459 inp->inp_moptions); 460 461 if (addr) { 462 in_pcbdisconnect(inp); 463 inp->inp_laddr = laddr; 464 splx(s); 465 } 466 return (error); 467 468 release: 469 m_freem(m); 470 return (error); 471 } 472 473 u_long udp_sendspace = 9216; /* really max datagram size */ 474 u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 475 /* 40 1K datagrams */ 476 477 /*ARGSUSED*/ 478 int 479 udp_usrreq(so, req, m, addr, control) 480 struct socket *so; 481 int req; 482 struct mbuf *m, *addr, *control; 483 { 484 struct inpcb *inp = sotoinpcb(so); 485 int error = 0; 486 int s; 487 488 if (req == PRU_CONTROL) 489 return (in_control(so, (long)m, (caddr_t)addr, 490 (struct ifnet *)control)); 491 if (inp == NULL && req != PRU_ATTACH) { 492 error = EINVAL; 493 goto release; 494 } 495 /* 496 * Note: need to block udp_input while changing 497 * the udp pcb queue and/or pcb addresses. 498 */ 499 switch (req) { 500 501 case PRU_ATTACH: 502 if (inp != NULL) { 503 error = EINVAL; 504 break; 505 } 506 s = splnet(); 507 error = in_pcballoc(so, &udbtable); 508 splx(s); 509 if (error) 510 break; 511 error = soreserve(so, udp_sendspace, udp_recvspace); 512 if (error) 513 break; 514 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = ip_defttl; 515 break; 516 517 case PRU_DETACH: 518 udp_detach(inp); 519 break; 520 521 case PRU_BIND: 522 s = splnet(); 523 error = in_pcbbind(inp, addr); 524 splx(s); 525 break; 526 527 case PRU_LISTEN: 528 error = EOPNOTSUPP; 529 break; 530 531 case PRU_CONNECT: 532 if (inp->inp_faddr.s_addr != INADDR_ANY) { 533 error = EISCONN; 534 break; 535 } 536 s = splnet(); 537 error = in_pcbconnect(inp, addr); 538 splx(s); 539 if (error == 0) 540 soisconnected(so); 541 break; 542 543 case PRU_CONNECT2: 544 error = EOPNOTSUPP; 545 break; 546 547 case PRU_ACCEPT: 548 error = EOPNOTSUPP; 549 break; 550 551 case PRU_DISCONNECT: 552 if (inp->inp_faddr.s_addr == INADDR_ANY) { 553 error = ENOTCONN; 554 break; 555 } 556 s = splnet(); 557 in_pcbdisconnect(inp); 558 inp->inp_laddr.s_addr = INADDR_ANY; 559 splx(s); 560 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 561 break; 562 563 case PRU_SHUTDOWN: 564 socantsendmore(so); 565 break; 566 567 case PRU_SEND: 568 return (udp_output(inp, m, addr, control)); 569 570 case PRU_ABORT: 571 soisdisconnected(so); 572 udp_detach(inp); 573 break; 574 575 case PRU_SOCKADDR: 576 in_setsockaddr(inp, addr); 577 break; 578 579 case PRU_PEERADDR: 580 in_setpeeraddr(inp, addr); 581 break; 582 583 case PRU_SENSE: 584 /* 585 * stat: don't bother with a blocksize. 586 */ 587 return (0); 588 589 case PRU_SENDOOB: 590 case PRU_FASTTIMO: 591 case PRU_SLOWTIMO: 592 case PRU_PROTORCV: 593 case PRU_PROTOSEND: 594 error = EOPNOTSUPP; 595 break; 596 597 case PRU_RCVD: 598 case PRU_RCVOOB: 599 return (EOPNOTSUPP); /* do not free mbuf's */ 600 601 default: 602 panic("udp_usrreq"); 603 } 604 605 release: 606 if (control) { 607 printf("udp control data unexpectedly retained\n"); 608 m_freem(control); 609 } 610 if (m) 611 m_freem(m); 612 return (error); 613 } 614 615 static void 616 udp_detach(inp) 617 struct inpcb *inp; 618 { 619 int s = splnet(); 620 621 if (inp == udp_last_inpcb) 622 udp_last_inpcb = 0; 623 in_pcbdetach(inp); 624 splx(s); 625 } 626 627 /* 628 * Sysctl for udp variables. 629 */ 630 udp_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 631 int *name; 632 u_int namelen; 633 void *oldp; 634 size_t *oldlenp; 635 void *newp; 636 size_t newlen; 637 { 638 /* All sysctl names at this level are terminal. */ 639 if (namelen != 1) 640 return (ENOTDIR); 641 642 switch (name[0]) { 643 case UDPCTL_CHECKSUM: 644 return (sysctl_int(oldp, oldlenp, newp, newlen, &udpcksum)); 645 default: 646 return (ENOPROTOOPT); 647 } 648 /* NOTREACHED */ 649 } 650
Indexes created Mon Sep 22 05:09:51 GMT 2025