1 /* 2 * Copyright (c) 1982, 1986, 1988, 1990 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)udp_usrreq.c 7.25 (Berkeley) 07/18/92 8 */ 9 10 #include "param.h" 11 #include "malloc.h" 12 #include "mbuf.h" 13 #include "protosw.h" 14 #include "socket.h" 15 #include "socketvar.h" 16 #include "errno.h" 17 #include "stat.h" 18 19 #include "../net/if.h" 20 #include "../net/route.h" 21 22 #include "in.h" 23 #include "in_systm.h" 24 #include "ip.h" 25 #include "in_pcb.h" 26 #include "ip_var.h" 27 #include "ip_icmp.h" 28 #include "udp.h" 29 #include "udp_var.h" 30 31 struct inpcb *udp_last_inpcb = &udb; 32 33 /* 34 * UDP protocol implementation. 35 * Per RFC 768, August, 1980. 36 */ 37 udp_init() 38 { 39 40 udb.inp_next = udb.inp_prev = &udb; 41 } 42 43 #ifndef COMPAT_42 44 int udpcksum = 1; 45 #else 46 int udpcksum = 0; /* XXX */ 47 #endif 48 int udp_ttl = UDP_TTL; 49 50 struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; 51 52 udp_input(m, iphlen) 53 register struct mbuf *m; 54 int iphlen; 55 { 56 register struct ip *ip; 57 register struct udphdr *uh; 58 register struct inpcb *inp; 59 struct mbuf *opts = 0; 60 int len; 61 struct ip save_ip; 62 63 udpstat.udps_ipackets++; 64 65 /* 66 * Strip IP options, if any; should skip this, 67 * make available to user, and use on returned packets, 68 * but we don't yet have a way to check the checksum 69 * with options still present. 70 */ 71 if (iphlen > sizeof (struct ip)) { 72 ip_stripoptions(m, (struct mbuf *)0); 73 iphlen = sizeof(struct ip); 74 } 75 76 /* 77 * Get IP and UDP header together in first mbuf. 78 */ 79 ip = mtod(m, struct ip *); 80 if (m->m_len < iphlen + sizeof(struct udphdr)) { 81 if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { 82 udpstat.udps_hdrops++; 83 return; 84 } 85 ip = mtod(m, struct ip *); 86 } 87 uh = (struct udphdr *)((caddr_t)ip + iphlen); 88 89 /* 90 * Make mbuf data length reflect UDP length. 91 * If not enough data to reflect UDP length, drop. 92 */ 93 len = ntohs((u_short)uh->uh_ulen); 94 if (ip->ip_len != len) { 95 if (len > ip->ip_len) { 96 udpstat.udps_badlen++; 97 goto bad; 98 } 99 m_adj(m, len - ip->ip_len); 100 /* ip->ip_len = len; */ 101 } 102 /* 103 * Save a copy of the IP header in case we want restore it 104 * for sending an ICMP error message in response. 105 */ 106 save_ip = *ip; 107 108 /* 109 * Checksum extended UDP header and data. 110 */ 111 if (udpcksum && uh->uh_sum) { 112 ((struct ipovly *)ip)->ih_next = 0; 113 ((struct ipovly *)ip)->ih_prev = 0; 114 ((struct ipovly *)ip)->ih_x1 = 0; 115 ((struct ipovly *)ip)->ih_len = uh->uh_ulen; 116 if (uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) { 117 udpstat.udps_badsum++; 118 m_freem(m); 119 return; 120 } 121 } 122 123 #ifdef MULTICAST 124 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || 125 in_broadcast(ip->ip_dst)) { 126 struct socket *last; 127 /* 128 * Deliver a multicast or broadcast datagram to *all* sockets 129 * for which the local and remote addresses and ports match 130 * those of the incoming datagram. This allows more than 131 * one process to receive multi/broadcasts on the same port. 132 * (This really ought to be done for unicast datagrams as 133 * well, but that would cause problems with existing 134 * applications that open both address-specific sockets and 135 * a wildcard socket listening to the same port -- they would 136 * end up receiving duplicates of every unicast datagram. 137 * Those applications open the multiple sockets to overcome an 138 * inadequacy of the UDP socket interface, but for backwards 139 * compatibility we avoid the problem here rather than 140 * fixing the interface. Maybe 4.4BSD will remedy this?) 141 */ 142 143 /* 144 * Construct sockaddr format source address. 145 */ 146 udp_in.sin_port = uh->uh_sport; 147 udp_in.sin_addr = ip->ip_src; 148 m->m_len -= sizeof (struct udpiphdr); 149 m->m_data += sizeof (struct udpiphdr); 150 /* 151 * Locate pcb(s) for datagram. 152 * (Algorithm copied from raw_intr().) 153 */ 154 last = NULL; 155 for (inp = udb.inp_next; inp != &udb; inp = inp->inp_next) { 156 if (inp->inp_lport != uh->uh_dport) 157 continue; 158 if (inp->inp_laddr.s_addr != INADDR_ANY) { 159 if (inp->inp_laddr.s_addr != 160 ip->ip_dst.s_addr) 161 continue; 162 } 163 if (inp->inp_faddr.s_addr != INADDR_ANY) { 164 if (inp->inp_faddr.s_addr != 165 ip->ip_src.s_addr || 166 inp->inp_fport != uh->uh_sport) 167 continue; 168 } 169 170 if (last != NULL) { 171 struct mbuf *n; 172 173 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { 174 if (sbappendaddr(&last->so_rcv, 175 (struct sockaddr *)&udp_in, 176 n, (struct mbuf *)0) == 0) 177 m_freem(n); 178 else 179 sorwakeup(last); 180 } 181 } 182 last = inp->inp_socket; 183 /* 184 * Don't look for additional matches if this one 185 * does not have the SO_REUSEPORT socket option set. 186 * This heuristic avoids searching through all pcbs 187 * in the common case of a non-shared port. It 188 * assumes that an application will never clear 189 * the SO_REUSEPORT option after setting it. 190 */ 191 if ((last->so_options & SO_REUSEPORT) == 0) 192 break; 193 } 194 195 if (last == NULL) { 196 /* 197 * No matching pcb found; discard datagram. 198 * (No need to send an ICMP Port Unreachable 199 * for a broadcast or multicast datgram.) 200 */ 201 goto bad; 202 } 203 if (sbappendaddr(&last->so_rcv, (struct sockaddr *)&udp_in, 204 m, (struct mbuf *)0) == 0) 205 goto bad; 206 sorwakeup(last); 207 return; 208 } 209 #endif 210 /* 211 * Locate pcb for datagram. 212 */ 213 inp = udp_last_inpcb; 214 if (inp->inp_lport != uh->uh_dport || 215 inp->inp_fport != uh->uh_sport || 216 inp->inp_faddr.s_addr != ip->ip_src.s_addr || 217 inp->inp_laddr.s_addr != ip->ip_dst.s_addr) { 218 inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport, 219 ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); 220 if (inp) 221 udp_last_inpcb = inp; 222 udpstat.udpps_pcbcachemiss++; 223 } 224 if (inp == 0) { 225 /* don't send ICMP response for broadcast packet */ 226 udpstat.udps_noport++; 227 #ifndef MULTICAST 228 /* XXX why don't we do this with MULTICAST? */ 229 if (m->m_flags & (M_BCAST | M_MCAST)) { 230 udpstat.udps_noportbcast++; 231 goto bad; 232 } 233 #endif 234 *ip = save_ip; 235 ip->ip_len += iphlen; 236 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT); 237 return; 238 } 239 240 /* 241 * Construct sockaddr format source address. 242 * Stuff source address and datagram in user buffer. 243 */ 244 udp_in.sin_port = uh->uh_sport; 245 udp_in.sin_addr = ip->ip_src; 246 if (inp->inp_flags & INP_CONTROLOPTS) { 247 struct mbuf **mp = &opts; 248 struct mbuf *udp_saveopt(); 249 250 if (inp->inp_flags & INP_RECVDSTADDR) { 251 *mp = udp_saveopt((caddr_t) &ip->ip_dst, 252 sizeof(struct in_addr), IP_RECVDSTADDR); 253 if (*mp) 254 mp = &(*mp)->m_next; 255 } 256 #ifdef notyet 257 /* options were tossed above */ 258 if (inp->inp_flags & INP_RECVOPTS) { 259 *mp = udp_saveopt((caddr_t) opts_deleted_above, 260 sizeof(struct in_addr), IP_RECVOPTS); 261 if (*mp) 262 mp = &(*mp)->m_next; 263 } 264 /* ip_srcroute doesn't do what we want here, need to fix */ 265 if (inp->inp_flags & INP_RECVRETOPTS) { 266 *mp = udp_saveopt((caddr_t) ip_srcroute(), 267 sizeof(struct in_addr), IP_RECVRETOPTS); 268 if (*mp) 269 mp = &(*mp)->m_next; 270 } 271 #endif 272 } 273 iphlen += sizeof(struct udphdr); 274 m->m_len -= iphlen; 275 m->m_pkthdr.len -= iphlen; 276 m->m_data += iphlen; 277 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, 278 m, opts) == 0) { 279 udpstat.udps_fullsock++; 280 goto bad; 281 } 282 sorwakeup(inp->inp_socket); 283 return; 284 bad: 285 m_freem(m); 286 if (opts) 287 m_freem(opts); 288 } 289 290 /* 291 * Create a "control" mbuf containing the specified data 292 * with the specified type for presentation with a datagram. 293 */ 294 struct mbuf * 295 udp_saveopt(p, size, type) 296 caddr_t p; 297 register int size; 298 int type; 299 { 300 register struct cmsghdr *cp; 301 struct mbuf *m; 302 303 if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) 304 return ((struct mbuf *) NULL); 305 cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); 306 bcopy(p, (caddr_t)(cp + 1), size); 307 size += sizeof(*cp); 308 m->m_len = size; 309 cp->cmsg_len = size; 310 cp->cmsg_level = IPPROTO_IP; 311 cp->cmsg_type = type; 312 return (m); 313 } 314 315 /* 316 * Notify a udp user of an asynchronous error; 317 * just wake up so that he can collect error status. 318 */ 319 udp_notify(inp, errno) 320 register struct inpcb *inp; 321 int errno; 322 { 323 324 inp->inp_socket->so_error = errno; 325 sorwakeup(inp->inp_socket); 326 sowwakeup(inp->inp_socket); 327 } 328 329 udp_ctlinput(cmd, sa, ip) 330 int cmd; 331 struct sockaddr *sa; 332 register struct ip *ip; 333 { 334 register struct udphdr *uh; 335 extern struct in_addr zeroin_addr; 336 extern u_char inetctlerrmap[]; 337 338 if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 339 return; 340 if (ip) { 341 uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 342 in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, 343 cmd, udp_notify); 344 } else 345 in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); 346 } 347 348 udp_output(inp, m, addr, control) 349 register struct inpcb *inp; 350 register struct mbuf *m; 351 struct mbuf *addr, *control; 352 { 353 register struct udpiphdr *ui; 354 register int len = m->m_pkthdr.len; 355 struct in_addr laddr; 356 int s, error = 0; 357 358 if (control) 359 m_freem(control); /* XXX */ 360 361 if (addr) { 362 laddr = inp->inp_laddr; 363 if (inp->inp_faddr.s_addr != INADDR_ANY) { 364 error = EISCONN; 365 goto release; 366 } 367 /* 368 * Must block input while temporarily connected. 369 */ 370 s = splnet(); 371 error = in_pcbconnect(inp, addr); 372 if (error) { 373 splx(s); 374 goto release; 375 } 376 } else { 377 if (inp->inp_faddr.s_addr == INADDR_ANY) { 378 error = ENOTCONN; 379 goto release; 380 } 381 } 382 /* 383 * Calculate data length and get a mbuf 384 * for UDP and IP headers. 385 */ 386 M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT); 387 if (m == 0) { 388 error = ENOBUFS; 389 goto release; 390 } 391 392 /* 393 * Fill in mbuf with extended UDP header 394 * and addresses and length put into network format. 395 */ 396 ui = mtod(m, struct udpiphdr *); 397 ui->ui_next = ui->ui_prev = 0; 398 ui->ui_x1 = 0; 399 ui->ui_pr = IPPROTO_UDP; 400 ui->ui_len = htons((u_short)len + sizeof (struct udphdr)); 401 ui->ui_src = inp->inp_laddr; 402 ui->ui_dst = inp->inp_faddr; 403 ui->ui_sport = inp->inp_lport; 404 ui->ui_dport = inp->inp_fport; 405 ui->ui_ulen = ui->ui_len; 406 407 /* 408 * Stuff checksum and output datagram. 409 */ 410 ui->ui_sum = 0; 411 if (udpcksum) { 412 if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0) 413 ui->ui_sum = 0xffff; 414 } 415 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 416 ((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl; /* XXX */ 417 ((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos; /* XXX */ 418 udpstat.udps_opackets++; 419 error = ip_output(m, inp->inp_options, &inp->inp_route, 420 inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST) 421 #ifdef MULTICAST 422 , inp->inp_moptions 423 #endif 424 ); 425 426 if (addr) { 427 in_pcbdisconnect(inp); 428 inp->inp_laddr = laddr; 429 splx(s); 430 } 431 return (error); 432 433 release: 434 m_freem(m); 435 return (error); 436 } 437 438 u_long udp_sendspace = 9216; /* really max datagram size */ 439 u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); 440 /* 40 1K datagrams */ 441 442 /*ARGSUSED*/ 443 udp_usrreq(so, req, m, addr, control) 444 struct socket *so; 445 int req; 446 struct mbuf *m, *addr, *control; 447 { 448 struct inpcb *inp = sotoinpcb(so); 449 int error = 0; 450 int s; 451 452 if (req == PRU_CONTROL) 453 return (in_control(so, (int)m, (caddr_t)addr, 454 (struct ifnet *)control)); 455 if (inp == NULL && req != PRU_ATTACH) { 456 error = EINVAL; 457 goto release; 458 } 459 /* 460 * Note: need to block udp_input while changing 461 * the udp pcb queue and/or pcb addresses. 462 */ 463 switch (req) { 464 465 case PRU_ATTACH: 466 if (inp != NULL) { 467 error = EINVAL; 468 break; 469 } 470 s = splnet(); 471 error = in_pcballoc(so, &udb); 472 splx(s); 473 if (error) 474 break; 475 error = soreserve(so, udp_sendspace, udp_recvspace); 476 if (error) 477 break; 478 ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = udp_ttl; 479 break; 480 481 case PRU_DETACH: 482 udp_detach(inp); 483 break; 484 485 case PRU_BIND: 486 s = splnet(); 487 error = in_pcbbind(inp, addr); 488 splx(s); 489 break; 490 491 case PRU_LISTEN: 492 error = EOPNOTSUPP; 493 break; 494 495 case PRU_CONNECT: 496 if (inp->inp_faddr.s_addr != INADDR_ANY) { 497 error = EISCONN; 498 break; 499 } 500 s = splnet(); 501 error = in_pcbconnect(inp, addr); 502 splx(s); 503 if (error == 0) 504 soisconnected(so); 505 break; 506 507 case PRU_CONNECT2: 508 error = EOPNOTSUPP; 509 break; 510 511 case PRU_ACCEPT: 512 error = EOPNOTSUPP; 513 break; 514 515 case PRU_DISCONNECT: 516 if (inp->inp_faddr.s_addr == INADDR_ANY) { 517 error = ENOTCONN; 518 break; 519 } 520 s = splnet(); 521 in_pcbdisconnect(inp); 522 inp->inp_laddr.s_addr = INADDR_ANY; 523 splx(s); 524 so->so_state &= ~SS_ISCONNECTED; /* XXX */ 525 break; 526 527 case PRU_SHUTDOWN: 528 socantsendmore(so); 529 break; 530 531 case PRU_SEND: 532 return (udp_output(inp, m, addr, control)); 533 534 case PRU_ABORT: 535 soisdisconnected(so); 536 udp_detach(inp); 537 break; 538 539 case PRU_SOCKADDR: 540 in_setsockaddr(inp, addr); 541 break; 542 543 case PRU_PEERADDR: 544 in_setpeeraddr(inp, addr); 545 break; 546 547 case PRU_SENSE: 548 /* 549 * stat: don't bother with a blocksize. 550 */ 551 return (0); 552 553 case PRU_SENDOOB: 554 case PRU_FASTTIMO: 555 case PRU_SLOWTIMO: 556 case PRU_PROTORCV: 557 case PRU_PROTOSEND: 558 error = EOPNOTSUPP; 559 break; 560 561 case PRU_RCVD: 562 case PRU_RCVOOB: 563 return (EOPNOTSUPP); /* do not free mbuf's */ 564 565 default: 566 panic("udp_usrreq"); 567 } 568 569 release: 570 if (control) { 571 printf("udp control data unexpectedly retained\n"); 572 m_freem(control); 573 } 574 if (m) 575 m_freem(m); 576 return (error); 577 } 578 579 udp_detach(inp) 580 struct inpcb *inp; 581 { 582 int s = splnet(); 583 584 if (inp == udp_last_inpcb) 585 udp_last_inpcb = &udb; 586 in_pcbdetach(inp); 587 splx(s); 588 } 589