1 /* $NetBSD: udp_usrreq.c,v 1.44 1998/01/05 10:32:16 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 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 8.6 (Berkeley) 5/23/95 36 */ 37 #include "ipkdb.h" 38 39 #include <sys/param.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/protosw.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/errno.h> 46 #include <sys/stat.h> 47 #include <sys/systm.h> 48 #include <sys/proc.h> 49 50 #include <vm/vm.h> 51 #include <sys/sysctl.h> 52 53 #include <net/if.h> 54 #include <net/route.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_systm.h> 58 #include <netinet/in_var.h> 59 #include <netinet/ip.h> 60 #include <netinet/in_pcb.h> 61 #include <netinet/ip_var.h> 62 #include <netinet/ip_icmp.h> 63 #include <netinet/udp.h> 64 #include <netinet/udp_var.h> 65 66 #include <machine/stdarg.h> 67 68 /* 69 * UDP protocol implementation. 70 * Per RFC 768, August, 1980. 71 */ 72 #ifndef COMPAT_42 73 int udpcksum = 1; 74 #else 75 int udpcksum = 0; /* XXX */ 76 #endif 77 78 static void udp_notify __P((struct inpcb *, int)); 79 80 #ifndef UDBHASHSIZE 81 #define UDBHASHSIZE 128 82 #endif 83 int udbhashsize = UDBHASHSIZE; 84 85 void 86 udp_init() 87 { 88 89 in_pcbinit(&udbtable, udbhashsize, udbhashsize); 90 } 91 92 void 93 #if __STDC__ 94 udp_input(struct mbuf *m, ...) 95 #else 96 udp_input(m, va_alist) 97 struct mbuf *m; 98 va_dcl 99 #endif 100 { 101 register struct ip *ip; 102 register struct udphdr *uh; 103 register struct inpcb *inp; 104 struct mbuf *opts = 0; 105 int len; 106 struct ip save_ip; 107 int iphlen; 108 va_list ap; 109 struct sockaddr_in udpsrc; 110 111 va_start(ap, m); 112 iphlen = va_arg(ap, int); 113 va_end(ap); 114 115 udpstat.udps_ipackets++; 116 117 /* 118 * Strip IP options, if any; should skip this, 119 * make available to user, and use on returned packets, 120 * but we don't yet have a way to check the checksum 121 * with options still present. 122 */ 123 if (iphlen > sizeof (struct ip)) { 124 ip_stripoptions(m, (struct mbuf *)0); 125 iphlen = sizeof(struct ip); 126 } 127 128 /* 129 * Get IP and UDP header together in first mbuf. 130 */ 131 ip = mtod(m, struct ip *); 132 if (m->m_len < iphlen + sizeof(struct udphdr)) { 133 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 134 udpstat.udps_hdrops++; 135 return; 136 } 137 ip = mtod(m, struct ip *); 138 } 139 uh = (struct udphdr *)((caddr_t)ip + iphlen); 140 141 /* 142 * Make mbuf data length reflect UDP length. 143 * If not enough data to reflect UDP length, drop. 144 */ 145 len = ntohs((u_int16_t)uh->uh_ulen); 146 if (ip->ip_len != len) { 147 if (len > ip->ip_len) { 148 udpstat.udps_badlen++; 149 goto bad; 150 } 151 m_adj(m, len - ip->ip_len); 152 /* ip->ip_len = len; */ 153 } 154 /* 155 * Save a copy of the IP header in case we want restore it 156 * for sending an ICMP error message in response. 157 */ 158 save_ip = *ip; 159 160 /* 161 * Checksum extended UDP header and data. 162 */ 163 if (uh->uh_sum) { 164 bzero(((struct ipovly *)ip)->ih_x1, 165 sizeof ((struct ipovly *)ip)->ih_x1); 166 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 167 if ((uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) != 0) { 168 udpstat.udps_badsum++; 169 m_freem(m); 170 return; 171 } 172 } 173 174 if (IN_MULTICAST(ip->ip_dst.s_addr) || 175 in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { 176 struct inpcb *last; 177 /* 178 * Deliver a multicast or broadcast datagram to *all* sockets 179 * for which the local and remote addresses and ports match 180 * those of the incoming datagram. This allows more than 181 * one process to receive multi/broadcasts on the same port. 182 * (This really ought to be done for unicast datagrams as 183 * well, but that would cause problems with existing 184 * applications that open both address-specific sockets and 185 * a wildcard socket listening to the same port -- they would 186 * end up receiving duplicates of every unicast datagram. 187 * Those applications open the multiple sockets to overcome an 188 * inadequacy of the UDP socket interface, but for backwards 189 * compatibility we avoid the problem here rather than 190 * fixing the interface. Maybe 4.5BSD will remedy this?) 191 */ 192 193 /* 194 * Construct sockaddr format source address. 195 */ 196 udpsrc.sin_family = AF_INET; 197 udpsrc.sin_len = sizeof(struct sockaddr_in); 198 udpsrc.sin_addr = ip->ip_src; 199 udpsrc.sin_port = uh->uh_sport; 200 bzero((caddr_t)udpsrc.sin_zero, sizeof(udpsrc.sin_zero)); 201 202 iphlen += sizeof(struct udphdr); 203 m->m_len -= iphlen; 204 m->m_pkthdr.len -= iphlen; 205 m->m_data += iphlen; 206 /* 207 * Locate pcb(s) for datagram. 208 * (Algorithm copied from raw_intr().) 209 */ 210 last = NULL; 211 for (inp = udbtable.inpt_queue.cqh_first; 212 inp != (struct inpcb *)&udbtable.inpt_queue; 213 inp = inp->inp_queue.cqe_next) { 214 if (inp->inp_lport != uh->uh_dport) 215 continue; 216 if (!in_nullhost(inp->inp_laddr)) { 217 if (!in_hosteq(inp->inp_laddr, ip->ip_dst)) 218 continue; 219 } 220 if (!in_nullhost(inp->inp_faddr)) { 221 if (!in_hosteq(inp->inp_faddr, ip->ip_src) || 222 inp->inp_fport != uh->uh_sport) 223 continue; 224 } 225 226 if (last != NULL) { 227 struct mbuf *n; 228 229 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 230 if (last->inp_flags & INP_CONTROLOPTS 231 || last->inp_socket->so_options & 232 SO_TIMESTAMP) { 233 ip_savecontrol(last, &opts, 234 ip, n); 235 } 236 if (sbappendaddr( 237 &last->inp_socket->so_rcv, 238 sintosa(&udpsrc), n, opts) == 0) { 239 m_freem(n); 240 if (opts) 241 m_freem(opts); 242 } else 243 sorwakeup(last->inp_socket); 244 opts = 0; 245 } 246 } 247 last = inp; 248 /* 249 * Don't look for additional matches if this one does 250 * not have either the SO_REUSEPORT or SO_REUSEADDR 251 * socket options set. This heuristic avoids searching 252 * through all pcbs in the common case of a non-shared 253 * port. It * assumes that an application will never 254 * clear these options after setting them. 255 */ 256 if ((last->inp_socket->so_options & 257 (SO_REUSEPORT|SO_REUSEADDR)) == 0) 258 break; 259 } 260 261 if (last == NULL) { 262 /* 263 * No matching pcb found; discard datagram. 264 * (No need to send an ICMP Port Unreachable 265 * for a broadcast or multicast datgram.) 266 */ 267 udpstat.udps_noportbcast++; 268 goto bad; 269 } 270 if (last->inp_flags & INP_CONTROLOPTS || 271 last->inp_socket->so_options & SO_TIMESTAMP) 272 ip_savecontrol(last, &opts, ip, m); 273 if (sbappendaddr(&last->inp_socket->so_rcv, 274 sintosa(&udpsrc), m, opts) == 0) { 275 udpstat.udps_fullsock++; 276 goto bad; 277 } 278 sorwakeup(last->inp_socket); 279 return; 280 } 281 /* 282 * Locate pcb for datagram. 283 */ 284 inp = in_pcblookup_connect(&udbtable, ip->ip_src, uh->uh_sport, 285 ip->ip_dst, uh->uh_dport); 286 if (inp == 0) { 287 ++udpstat.udps_pcbhashmiss; 288 inp = in_pcblookup_bind(&udbtable, ip->ip_dst, uh->uh_dport); 289 if (inp == 0) { 290 udpstat.udps_noport++; 291 if (m->m_flags & (M_BCAST | M_MCAST)) { 292 udpstat.udps_noportbcast++; 293 goto bad; 294 } 295 *ip = save_ip; 296 #if NIPKDB > 0 297 if (checkipkdb(&ip->ip_src, 298 uh->uh_sport, 299 uh->uh_dport, 300 m, 301 iphlen + sizeof(struct udphdr), 302 len - sizeof(struct udphdr))) 303 /* It was a debugger connect packet, just drop it now */ 304 goto bad; 305 #endif 306 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); 307 return; 308 } 309 } 310 311 /* 312 * Construct sockaddr format source address. 313 * Stuff source address and datagram in user buffer. 314 */ 315 udpsrc.sin_family = AF_INET; 316 udpsrc.sin_len = sizeof(struct sockaddr_in); 317 udpsrc.sin_addr = ip->ip_src; 318 udpsrc.sin_port = uh->uh_sport; 319 bzero((caddr_t)udpsrc.sin_zero, sizeof(udpsrc.sin_zero)); 320 321 if (inp->inp_flags & INP_CONTROLOPTS || 322 inp->inp_socket->so_options & SO_TIMESTAMP) 323 ip_savecontrol(inp, &opts, ip, m); 324 iphlen += sizeof(struct udphdr); 325 m->m_len -= iphlen; 326 m->m_pkthdr.len -= iphlen; 327 m->m_data += iphlen; 328 if (sbappendaddr(&inp->inp_socket->so_rcv, sintosa(&udpsrc), m, 329 opts) == 0) { 330 udpstat.udps_fullsock++; 331 goto bad; 332 } 333 sorwakeup(inp->inp_socket); 334 return; 335 bad: 336 m_freem(m); 337 if (opts) 338 m_freem(opts); 339 } 340 341 /* 342 * Notify a udp user of an asynchronous error; 343 * just wake up so that he can collect error status. 344 */ 345 static void 346 udp_notify(inp, errno) 347 register struct inpcb *inp; 348 int errno; 349 { 350 351 inp->inp_socket->so_error = errno; 352 sorwakeup(inp->inp_socket); 353 sowwakeup(inp->inp_socket); 354 } 355 356 void * 357 udp_ctlinput(cmd, sa, v) 358 int cmd; 359 struct sockaddr *sa; 360 void *v; 361 { 362 register struct ip *ip = v; 363 register struct udphdr *uh; 364 extern int inetctlerrmap[]; 365 void (*notify) __P((struct inpcb *, int)) = udp_notify; 366 int errno; 367 368 if ((unsigned)cmd >= PRC_NCMDS) 369 return NULL; 370 errno = inetctlerrmap[cmd]; 371 if (PRC_IS_REDIRECT(cmd)) 372 notify = in_rtchange, ip = 0; 373 else if (cmd == PRC_HOSTDEAD) 374 ip = 0; 375 else if (errno == 0) 376 return NULL; 377 if (ip) { 378 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 379 in_pcbnotify(&udbtable, satosin(sa)->sin_addr, uh->uh_dport, 380 ip->ip_src, uh->uh_sport, errno, notify); 381 } else 382 in_pcbnotifyall(&udbtable, satosin(sa)->sin_addr, errno, 383 notify); 384 return NULL; 385 } 386 387 int 388 #if __STDC__ 389 udp_output(struct mbuf *m, ...) 390 #else 391 udp_output(m, va_alist) 392 struct mbuf *m; 393 va_dcl 394 #endif 395 { 396 register struct inpcb *inp; 397 register struct udpiphdr *ui; 398 register int len = m->m_pkthdr.len; 399 int error = 0; 400 va_list ap; 401 402 va_start(ap, m); 403 inp = va_arg(ap, struct inpcb *); 404 va_end(ap); 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_DONTWAIT); 411 if (m == 0) { 412 error = ENOBUFS; 413 goto release; 414 } 415 416 /* 417 * Compute the packet length of the IP header, and 418 * punt if the length looks bogus. 419 */ 420 if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) { 421 error = EMSGSIZE; 422 goto release; 423 } 424 425 /* 426 * Fill in mbuf with extended UDP header 427 * and addresses and length put into network format. 428 */ 429 ui = mtod(m, struct udpiphdr *); 430 bzero(ui->ui_x1, sizeof ui->ui_x1); 431 ui->ui_pr = IPPROTO_UDP; 432 ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr)); 433 ui->ui_src = inp->inp_laddr; 434 ui->ui_dst = inp->inp_faddr; 435 ui->ui_sport = inp->inp_lport; 436 ui->ui_dport = inp->inp_fport; 437 ui->ui_ulen = ui->ui_len; 438 439 /* 440 * Stuff checksum and output datagram. 441 */ 442 ui->ui_sum = 0; 443 if (udpcksum) { 444 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 445 ui->ui_sum = 0xffff; 446 } 447 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 448 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 449 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 450 udpstat.udps_opackets++; 451 return (ip_output(m, inp->inp_options, &inp->inp_route, 452 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST), 453 inp->inp_moptions)); 454 455 release: 456 m_freem(m); 457 return (error); 458 } 459 460 int udp_sendspace = 9216; /* really max datagram size */ 461 int udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 462 /* 40 1K datagrams */ 463 464 /*ARGSUSED*/ 465 int 466 udp_usrreq(so, req, m, nam, control, p) 467 struct socket *so; 468 int req; 469 struct mbuf *m, *nam, *control; 470 struct proc *p; 471 { 472 register struct inpcb *inp; 473 int s; 474 register int error = 0; 475 476 if (req == PRU_CONTROL) 477 return (in_control(so, (long)m, (caddr_t)nam, 478 (struct ifnet *)control, p)); 479 480 s = splsoftnet(); 481 inp = sotoinpcb(so); 482 #ifdef DIAGNOSTIC 483 if (req != PRU_SEND && req != PRU_SENDOOB && control) 484 panic("udp_usrreq: unexpected control mbuf"); 485 #endif 486 if (inp == 0 && req != PRU_ATTACH) { 487 error = EINVAL; 488 goto release; 489 } 490 491 /* 492 * Note: need to block udp_input while changing 493 * the udp pcb queue and/or pcb addresses. 494 */ 495 switch (req) { 496 497 case PRU_ATTACH: 498 if (inp != 0) { 499 error = EISCONN; 500 break; 501 } 502 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 503 error = soreserve(so, udp_sendspace, udp_recvspace); 504 if (error) 505 break; 506 } 507 error = in_pcballoc(so, &udbtable); 508 if (error) 509 break; 510 inp = sotoinpcb(so); 511 inp->inp_ip.ip_ttl = ip_defttl; 512 break; 513 514 case PRU_DETACH: 515 in_pcbdetach(inp); 516 break; 517 518 case PRU_BIND: 519 error = in_pcbbind(inp, nam, p); 520 break; 521 522 case PRU_LISTEN: 523 error = EOPNOTSUPP; 524 break; 525 526 case PRU_CONNECT: 527 error = in_pcbconnect(inp, nam); 528 if (error) 529 break; 530 soisconnected(so); 531 break; 532 533 case PRU_CONNECT2: 534 error = EOPNOTSUPP; 535 break; 536 537 case PRU_DISCONNECT: 538 /*soisdisconnected(so);*/ 539 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 540 in_pcbdisconnect(inp); 541 inp->inp_laddr = zeroin_addr; /* XXX */ 542 in_pcbstate(inp, INP_BOUND); /* XXX */ 543 break; 544 545 case PRU_SHUTDOWN: 546 socantsendmore(so); 547 break; 548 549 case PRU_RCVD: 550 error = EOPNOTSUPP; 551 break; 552 553 case PRU_SEND: 554 if (control && control->m_len) { 555 m_freem(control); 556 m_freem(m); 557 error = EINVAL; 558 break; 559 } 560 { 561 struct in_addr laddr; /* XXX */ 562 563 if (nam) { 564 laddr = inp->inp_laddr; /* XXX */ 565 if ((so->so_state & SS_ISCONNECTED) != 0) { 566 error = EISCONN; 567 goto die; 568 } 569 error = in_pcbconnect(inp, nam); 570 if (error) { 571 die: 572 m_freem(m); 573 break; 574 } 575 } else { 576 if ((so->so_state & SS_ISCONNECTED) == 0) { 577 error = ENOTCONN; 578 goto die; 579 } 580 } 581 error = udp_output(m, inp); 582 if (nam) { 583 in_pcbdisconnect(inp); 584 inp->inp_laddr = laddr; /* XXX */ 585 in_pcbstate(inp, INP_BOUND); /* XXX */ 586 } 587 } 588 break; 589 590 case PRU_SENSE: 591 /* 592 * stat: don't bother with a blocksize. 593 */ 594 splx(s); 595 return (0); 596 597 case PRU_RCVOOB: 598 error = EOPNOTSUPP; 599 break; 600 601 case PRU_SENDOOB: 602 m_freem(control); 603 m_freem(m); 604 error = EOPNOTSUPP; 605 break; 606 607 case PRU_SOCKADDR: 608 in_setsockaddr(inp, nam); 609 break; 610 611 case PRU_PEERADDR: 612 in_setpeeraddr(inp, nam); 613 break; 614 615 default: 616 panic("udp_usrreq"); 617 } 618 619 release: 620 splx(s); 621 return (error); 622 } 623 624 /* 625 * Sysctl for udp variables. 626 */ 627 int 628 udp_sysctl(name, namelen, oldp, oldlenp, newp, newlen) 629 int *name; 630 u_int namelen; 631 void *oldp; 632 size_t *oldlenp; 633 void *newp; 634 size_t newlen; 635 { 636 /* All sysctl names at this level are terminal. */ 637 if (namelen != 1) 638 return (ENOTDIR); 639 640 switch (name[0]) { 641 case UDPCTL_CHECKSUM: 642 return (sysctl_int(oldp, oldlenp, newp, newlen, &udpcksum)); 643 case UDPCTL_SENDSPACE: 644 return (sysctl_int(oldp, oldlenp, newp, newlen, 645 &udp_sendspace)); 646 case UDPCTL_RECVSPACE: 647 return (sysctl_int(oldp, oldlenp, newp, newlen, 648 &udp_recvspace)); 649 default: 650 return (ENOPROTOOPT); 651 } 652 /* NOTREACHED */ 653 } 654