| File: | src/usr.sbin/dhcpd/dhcp.c |
| Warning: | line 699, column 2 Value stored to 'result' is never read |
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| 1 | /* $OpenBSD: dhcp.c,v 1.57 2017/07/11 10:28:24 reyk Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1995, 1996, 1997, 1998, 1999 |
| 5 | * The Internet Software Consortium. 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 | * |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. Neither the name of The Internet Software Consortium nor the names |
| 17 | * of its contributors may be used to endorse or promote products derived |
| 18 | * from this software without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND |
| 21 | * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| 22 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 23 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 24 | * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR |
| 25 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 26 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 27 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| 28 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| 29 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 30 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 31 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 32 | * SUCH DAMAGE. |
| 33 | * |
| 34 | * This software has been written for the Internet Software Consortium |
| 35 | * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie |
| 36 | * Enterprises. To learn more about the Internet Software Consortium, |
| 37 | * see ``http://www.vix.com/isc''. To learn more about Vixie |
| 38 | * Enterprises, see ``http://www.vix.com''. |
| 39 | */ |
| 40 | |
| 41 | #include <sys/types.h> |
| 42 | #include <sys/socket.h> |
| 43 | |
| 44 | #include <arpa/inet.h> |
| 45 | |
| 46 | #include <net/if.h> |
| 47 | |
| 48 | #include <netinet/in.h> |
| 49 | |
| 50 | #include <errno(*__errno()).h> |
| 51 | #include <stdio.h> |
| 52 | #include <stdlib.h> |
| 53 | #include <string.h> |
| 54 | |
| 55 | #include "dhcp.h" |
| 56 | #include "tree.h" |
| 57 | #include "dhcpd.h" |
| 58 | #include "log.h" |
| 59 | #include "sync.h" |
| 60 | |
| 61 | int outstanding_pings; |
| 62 | |
| 63 | static char dhcp_message[256]; |
| 64 | |
| 65 | void |
| 66 | dhcp(struct packet *packet, int is_udpsock) |
| 67 | { |
| 68 | if (!locate_network(packet) && packet->packet_type != DHCPREQUEST3) |
| 69 | return; |
| 70 | |
| 71 | if (is_udpsock && packet->packet_type != DHCPINFORM8) { |
| 72 | log_info("Unable to handle a DHCP message type=%d on UDP " |
| 73 | "socket", packet->packet_type); |
| 74 | return; |
| 75 | } |
| 76 | |
| 77 | switch (packet->packet_type) { |
| 78 | case DHCPDISCOVER1: |
| 79 | dhcpdiscover(packet); |
| 80 | break; |
| 81 | |
| 82 | case DHCPREQUEST3: |
| 83 | dhcprequest(packet); |
| 84 | break; |
| 85 | |
| 86 | case DHCPRELEASE7: |
| 87 | dhcprelease(packet); |
| 88 | break; |
| 89 | |
| 90 | case DHCPDECLINE4: |
| 91 | dhcpdecline(packet); |
| 92 | break; |
| 93 | |
| 94 | case DHCPINFORM8: |
| 95 | dhcpinform(packet); |
| 96 | break; |
| 97 | |
| 98 | default: |
| 99 | break; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | void |
| 104 | dhcpdiscover(struct packet *packet) |
| 105 | { |
| 106 | struct lease *lease = find_lease(packet, packet->shared_network, 0); |
| 107 | struct host_decl *hp; |
| 108 | |
| 109 | log_info("DHCPDISCOVER from %s via %s", |
| 110 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 111 | packet->raw->chaddr), |
| 112 | packet->raw->giaddr.s_addr ? inet_ntoa(packet->raw->giaddr) : |
| 113 | packet->interface->name); |
| 114 | |
| 115 | /* Sourceless packets don't make sense here. */ |
| 116 | if (!packet->shared_network) { |
| 117 | log_info("Packet from unknown subnet: %s", |
| 118 | inet_ntoa(packet->raw->giaddr)); |
| 119 | return; |
| 120 | } |
| 121 | |
| 122 | /* If we didn't find a lease, try to allocate one... */ |
| 123 | if (!lease) { |
| 124 | lease = packet->shared_network->last_lease; |
| 125 | |
| 126 | /* |
| 127 | * If there are no leases in that subnet that have |
| 128 | * expired, we have nothing to offer this client. |
| 129 | */ |
| 130 | if (!lease || lease->ends > cur_time) { |
| 131 | log_info("no free leases on subnet %s", |
| 132 | packet->shared_network->name); |
| 133 | return; |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * If we find an abandoned lease, take it, but print a |
| 138 | * warning message, so that if it continues to lose, |
| 139 | * the administrator will eventually investigate. |
| 140 | */ |
| 141 | if ((lease->flags & ABANDONED_LEASE16)) { |
| 142 | struct lease *lp; |
| 143 | |
| 144 | /* See if we can find an unabandoned lease first. */ |
| 145 | for (lp = lease; lp; lp = lp->prev) { |
| 146 | if (lp->ends > cur_time) |
| 147 | break; |
| 148 | if (!(lp->flags & ABANDONED_LEASE16)) { |
| 149 | lease = lp; |
| 150 | break; |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * If we can't find an unabandoned lease, |
| 156 | * reclaim the abandoned lease. |
| 157 | */ |
| 158 | if ((lease->flags & ABANDONED_LEASE16)) { |
| 159 | log_warnx("Reclaiming abandoned IP address %s.", |
| 160 | piaddr(lease->ip_addr)); |
| 161 | lease->flags &= ~ABANDONED_LEASE16; |
| 162 | |
| 163 | pfmsg('L', lease); /* unabandon address */ |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | /* Try to find a host_decl that matches the client |
| 168 | identifier or hardware address on the packet, and |
| 169 | has no fixed IP address. If there is one, hang |
| 170 | it off the lease so that its option definitions |
| 171 | can be used. */ |
| 172 | if (((packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len != 0) && |
| 173 | ((hp = find_hosts_by_uid( |
| 174 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].data, |
| 175 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len)) != |
| 176 | NULL((void *)0))) || |
| 177 | ((hp = find_hosts_by_haddr(packet->raw->htype, |
| 178 | packet->raw->chaddr, packet->raw->hlen)) != NULL((void *)0))) { |
| 179 | for (; hp; hp = hp->n_ipaddr) { |
| 180 | if (!hp->fixed_addr) { |
| 181 | lease->host = hp; |
| 182 | break; |
| 183 | } |
| 184 | } |
| 185 | } else |
| 186 | lease->host = NULL((void *)0); |
| 187 | } |
| 188 | |
| 189 | /* If this subnet won't boot unknown clients, ignore the |
| 190 | request. */ |
| 191 | if (!lease->host && |
| 192 | !lease->subnet->group->boot_unknown_clients) { |
| 193 | log_info("Ignoring unknown client %s", |
| 194 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 195 | packet->raw->chaddr)); |
| 196 | } else if (lease->host && !lease->host->group->allow_booting) { |
| 197 | log_info("Declining to boot client %s", |
| 198 | lease->host->name ? lease->host->name : |
| 199 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 200 | packet->raw->chaddr)); |
| 201 | } else |
| 202 | ack_lease(packet, lease, DHCPOFFER2, cur_time + 120); |
| 203 | } |
| 204 | |
| 205 | void |
| 206 | dhcprequest(struct packet *packet) |
| 207 | { |
| 208 | struct lease *lease; |
| 209 | struct iaddr cip; |
| 210 | struct subnet *subnet; |
| 211 | int ours = 0; |
| 212 | |
| 213 | cip.len = 4; |
| 214 | if (packet->options[DHO_DHCP_REQUESTED_ADDRESS50].len == 4) |
| 215 | memcpy(cip.iabuf, |
| 216 | packet->options[DHO_DHCP_REQUESTED_ADDRESS50].data, 4); |
| 217 | else |
| 218 | memcpy(cip.iabuf, &packet->raw->ciaddr.s_addr, 4); |
| 219 | subnet = find_subnet(cip); |
| 220 | |
| 221 | /* Find the lease that matches the address requested by the client. */ |
| 222 | |
| 223 | if (subnet) |
| 224 | lease = find_lease(packet, subnet->shared_network, &ours); |
| 225 | else |
| 226 | lease = NULL((void *)0); |
| 227 | |
| 228 | log_info("DHCPREQUEST for %s from %s via %s", piaddr(cip), |
| 229 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 230 | packet->raw->chaddr), |
| 231 | packet->raw->giaddr.s_addr ? inet_ntoa(packet->raw->giaddr) : |
| 232 | packet->interface->name); |
| 233 | |
| 234 | /* If a client on a given network REQUESTs a lease on an |
| 235 | * address on a different network, NAK it. If the Requested |
| 236 | * Address option was used, the protocol says that it must |
| 237 | * have been broadcast, so we can trust the source network |
| 238 | * information. |
| 239 | * |
| 240 | * If ciaddr was specified and Requested Address was not, then |
| 241 | * we really only know for sure what network a packet came from |
| 242 | * if it came through a BOOTP gateway - if it came through an |
| 243 | * IP router, we'll just have to assume that it's cool. |
| 244 | * |
| 245 | * If we don't think we know where the packet came from, it |
| 246 | * came through a gateway from an unknown network, so it's not |
| 247 | * from a RENEWING client. If we recognize the network it |
| 248 | * *thinks* it's on, we can NAK it even though we don't |
| 249 | * recognize the network it's *actually* on; otherwise we just |
| 250 | * have to ignore it. |
| 251 | * |
| 252 | * We don't currently try to take advantage of access to the |
| 253 | * raw packet, because it's not available on all platforms. |
| 254 | * So a packet that was unicast to us through a router from a |
| 255 | * RENEWING client is going to look exactly like a packet that |
| 256 | * was broadcast to us from an INIT-REBOOT client. |
| 257 | * |
| 258 | * Since we can't tell the difference between these two kinds |
| 259 | * of packets, if the packet appears to have come in off the |
| 260 | * local wire, we have to treat it as if it's a RENEWING |
| 261 | * client. This means that we can't NAK a RENEWING client on |
| 262 | * the local wire that has a bogus address. The good news is |
| 263 | * that we won't ACK it either, so it should revert to INIT |
| 264 | * state and send us a DHCPDISCOVER, which we *can* work with. |
| 265 | * |
| 266 | * Because we can't detect that a RENEWING client is on the |
| 267 | * wrong wire, it's going to sit there trying to renew until |
| 268 | * it gets to the REBIND state, when we *can* NAK it because |
| 269 | * the packet will get to us through a BOOTP gateway. We |
| 270 | * shouldn't actually see DHCPREQUEST packets from RENEWING |
| 271 | * clients on the wrong wire anyway, since their idea of their |
| 272 | * local router will be wrong. In any case, the protocol |
| 273 | * doesn't really allow us to NAK a DHCPREQUEST from a |
| 274 | * RENEWING client, so we can punt on this issue. |
| 275 | */ |
| 276 | if (!packet->shared_network || |
| 277 | (packet->raw->ciaddr.s_addr && packet->raw->giaddr.s_addr) || |
| 278 | (packet->options[DHO_DHCP_REQUESTED_ADDRESS50].len == 4 && |
| 279 | !packet->raw->ciaddr.s_addr)) { |
| 280 | |
| 281 | /* |
| 282 | * If we don't know where it came from but we do know |
| 283 | * where it claims to have come from, it didn't come |
| 284 | * from there. Fry it. |
| 285 | */ |
| 286 | if (!packet->shared_network) { |
| 287 | if (subnet && |
| 288 | subnet->shared_network->group->authoritative) { |
| 289 | nak_lease(packet, &cip); |
| 290 | return; |
| 291 | } |
| 292 | /* Otherwise, ignore it. */ |
| 293 | return; |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * If we do know where it came from and it asked for an |
| 298 | * address that is not on that shared network, nak it. |
| 299 | */ |
| 300 | subnet = find_grouped_subnet(packet->shared_network, cip); |
| 301 | if (!subnet) { |
| 302 | if (packet->shared_network->group->authoritative) |
| 303 | nak_lease(packet, &cip); |
| 304 | return; |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | /* |
| 309 | * If we found a lease for the client but it's not the one the |
| 310 | * client asked for, don't send it - some other server probably |
| 311 | * made the cut. |
| 312 | */ |
| 313 | if (lease && !addr_eq(lease->ip_addr, cip)) { |
| 314 | /* |
| 315 | * If we found the address the client asked for, but |
| 316 | * it wasn't what got picked, the lease belongs to us, |
| 317 | * so we should NAK it. |
| 318 | */ |
| 319 | if (ours) |
| 320 | nak_lease(packet, &cip); |
| 321 | return; |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * If the address the client asked for is ours, but it wasn't |
| 326 | * available for the client, NAK it. |
| 327 | */ |
| 328 | if (!lease && ours) { |
| 329 | nak_lease(packet, &cip); |
| 330 | return; |
| 331 | } |
| 332 | |
| 333 | /* If we're not allowed to serve this client anymore, don't. */ |
| 334 | if (lease && !lease->host && |
| 335 | !lease->subnet->group->boot_unknown_clients) { |
| 336 | log_info("Ignoring unknown client %s", |
| 337 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 338 | packet->raw->chaddr)); |
| 339 | return; |
| 340 | } else if (lease && lease->host && !lease->host->group->allow_booting) |
| 341 | { |
| 342 | log_info("Declining to renew client %s", |
| 343 | lease->host->name ? lease->host->name : |
| 344 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 345 | packet->raw->chaddr)); |
| 346 | return; |
| 347 | } |
| 348 | |
| 349 | /* |
| 350 | * If we own the lease that the client is asking for, |
| 351 | * and it's already been assigned to the client, ack it. |
| 352 | */ |
| 353 | if (lease && |
| 354 | ((lease->uid_len && lease->uid_len == |
| 355 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len && |
| 356 | !memcmp(packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].data, |
| 357 | lease->uid, lease->uid_len)) || |
| 358 | (lease->hardware_addr.hlen == packet->raw->hlen && |
| 359 | lease->hardware_addr.htype == packet->raw->htype && |
| 360 | !memcmp(lease->hardware_addr.haddr, packet->raw->chaddr, |
| 361 | packet->raw->hlen)))) { |
| 362 | ack_lease(packet, lease, DHCPACK5, 0); |
| 363 | sync_lease(lease); |
| 364 | return; |
| 365 | } |
| 366 | |
| 367 | /* |
| 368 | * At this point, the client has requested a lease, and it's |
| 369 | * available, but it wasn't assigned to the client, which |
| 370 | * means that the client probably hasn't gone through the |
| 371 | * DHCPDISCOVER part of the protocol. We are within our |
| 372 | * rights to send a DHCPNAK. We can also send a DHCPACK. |
| 373 | * The thing we probably should not do is to remain silent. |
| 374 | * For now, we'll just assign the lease to the client anyway. |
| 375 | */ |
| 376 | if (lease) { |
| 377 | ack_lease(packet, lease, DHCPACK5, 0); |
| 378 | sync_lease(lease); |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | void |
| 383 | dhcprelease(struct packet *packet) |
| 384 | { |
| 385 | char ciaddrbuf[INET_ADDRSTRLEN16]; |
| 386 | struct lease *lease; |
| 387 | struct iaddr cip; |
| 388 | int i; |
| 389 | |
| 390 | /* |
| 391 | * DHCPRELEASE must not specify address in requested-address |
| 392 | * option, but old protocol specs weren't explicit about this, |
| 393 | * so let it go. |
| 394 | */ |
| 395 | if (packet->options[DHO_DHCP_REQUESTED_ADDRESS50].len) { |
| 396 | log_info("DHCPRELEASE from %s specified requested-address.", |
| 397 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 398 | packet->raw->chaddr)); |
| 399 | } |
| 400 | |
| 401 | i = DHO_DHCP_CLIENT_IDENTIFIER61; |
| 402 | if (packet->options[i].len) { |
| 403 | lease = find_lease_by_uid(packet->options[i].data, |
| 404 | packet->options[i].len); |
| 405 | |
| 406 | /* |
| 407 | * See if we can find a lease that matches the |
| 408 | * IP address the client is claiming. |
| 409 | */ |
| 410 | for (; lease; lease = lease->n_uid) { |
| 411 | if (!memcmp(&packet->raw->ciaddr, |
| 412 | lease->ip_addr.iabuf, 4)) { |
| 413 | break; |
| 414 | } |
| 415 | } |
| 416 | } else { |
| 417 | /* |
| 418 | * The client is supposed to pass a valid client-identifier, |
| 419 | * but the spec on this has changed historically, so try the |
| 420 | * IP address in ciaddr if the client-identifier fails. |
| 421 | */ |
| 422 | cip.len = 4; |
| 423 | memcpy(cip.iabuf, &packet->raw->ciaddr, 4); |
| 424 | lease = find_lease_by_ip_addr(cip); |
| 425 | } |
| 426 | |
| 427 | /* Can't do >1 inet_ntoa() in a printf()! */ |
| 428 | strlcpy(ciaddrbuf, inet_ntoa(packet->raw->ciaddr), sizeof(ciaddrbuf)); |
| 429 | |
| 430 | log_info("DHCPRELEASE of %s from %s via %s (%sfound)", |
| 431 | ciaddrbuf, |
| 432 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 433 | packet->raw->chaddr), |
| 434 | packet->raw->giaddr.s_addr ? inet_ntoa(packet->raw->giaddr) : |
| 435 | packet->interface->name, |
| 436 | lease ? "" : "not "); |
| 437 | |
| 438 | /* If we're already acking this lease, don't do it again. */ |
| 439 | if (lease && lease->state) { |
| 440 | log_info("DHCPRELEASE already acking lease %s", |
| 441 | piaddr(lease->ip_addr)); |
| 442 | return; |
| 443 | } |
| 444 | |
| 445 | /* If we found a lease, release it. */ |
| 446 | if (lease && lease->ends > cur_time) { |
| 447 | /* |
| 448 | * First, we ping this lease to see if it's still |
| 449 | * there. if it is, we don't release it. This avoids |
| 450 | * the problem of spoofed releases being used to liberate |
| 451 | * addresses from the server. |
| 452 | */ |
| 453 | if (!lease->releasing) { |
| 454 | log_info("DHCPRELEASE of %s from %s via %s (found)", |
| 455 | ciaddrbuf, |
| 456 | print_hw_addr(packet->raw->htype, |
| 457 | packet->raw->hlen, packet->raw->chaddr), |
| 458 | packet->raw->giaddr.s_addr ? |
| 459 | inet_ntoa(packet->raw->giaddr) : |
| 460 | packet->interface->name); |
| 461 | |
| 462 | lease->releasing = 1; |
| 463 | add_timeout(cur_time + 1, lease_ping_timeout, lease); |
| 464 | icmp_echorequest(&(lease->ip_addr)); |
| 465 | ++outstanding_pings; |
| 466 | } else { |
| 467 | log_info("DHCPRELEASE of %s from %s via %s ignored " |
| 468 | "(release already pending)", |
| 469 | ciaddrbuf, |
| 470 | print_hw_addr(packet->raw->htype, |
| 471 | packet->raw->hlen, packet->raw->chaddr), |
| 472 | packet->raw->giaddr.s_addr ? |
| 473 | inet_ntoa(packet->raw->giaddr) : |
| 474 | packet->interface->name); |
| 475 | } |
| 476 | } else { |
| 477 | log_info("DHCPRELEASE of %s from %s via %s for nonexistent " |
| 478 | "lease", ciaddrbuf, print_hw_addr(packet->raw->htype, |
| 479 | packet->raw->hlen, packet->raw->chaddr), |
| 480 | packet->raw->giaddr.s_addr ? |
| 481 | inet_ntoa(packet->raw->giaddr) : packet->interface->name); |
| 482 | } |
| 483 | } |
| 484 | |
| 485 | void |
| 486 | dhcpdecline(struct packet *packet) |
| 487 | { |
| 488 | struct lease *lease; |
| 489 | struct iaddr cip; |
| 490 | |
| 491 | /* DHCPDECLINE must specify address. */ |
| 492 | if (packet->options[DHO_DHCP_REQUESTED_ADDRESS50].len != 4) |
| 493 | return; |
| 494 | |
| 495 | cip.len = 4; |
| 496 | memcpy(cip.iabuf, |
| 497 | packet->options[DHO_DHCP_REQUESTED_ADDRESS50].data, 4); |
| 498 | lease = find_lease_by_ip_addr(cip); |
| 499 | |
| 500 | log_info("DHCPDECLINE on %s from %s via %s", |
| 501 | piaddr(cip), print_hw_addr(packet->raw->htype, |
| 502 | packet->raw->hlen, packet->raw->chaddr), |
| 503 | packet->raw->giaddr.s_addr ? inet_ntoa(packet->raw->giaddr) : |
| 504 | packet->interface->name); |
| 505 | |
| 506 | /* If we're already acking this lease, don't do it again. */ |
| 507 | if (lease && lease->state) { |
| 508 | log_info("DHCPDECLINE already acking lease %s", |
| 509 | piaddr(lease->ip_addr)); |
| 510 | return; |
| 511 | } |
| 512 | |
| 513 | /* If we found a lease, mark it as unusable and complain. */ |
| 514 | if (lease) |
| 515 | abandon_lease(lease, "declined."); |
| 516 | } |
| 517 | |
| 518 | void |
| 519 | dhcpinform(struct packet *packet) |
| 520 | { |
| 521 | struct lease lease; |
| 522 | struct iaddr cip; |
| 523 | struct subnet *subnet; |
| 524 | |
| 525 | /* |
| 526 | * ciaddr should be set to client's IP address but |
| 527 | * not all clients are standards compliant. |
| 528 | */ |
| 529 | cip.len = 4; |
| 530 | if (packet->raw->ciaddr.s_addr && !packet->raw->giaddr.s_addr) { |
| 531 | if (memcmp(&packet->raw->ciaddr.s_addr, |
| 532 | packet->client_addr.iabuf, 4) != 0) { |
| 533 | log_info("DHCPINFORM from %s but ciaddr %s is not " |
| 534 | "consistent with actual address", |
| 535 | piaddr(packet->client_addr), |
| 536 | inet_ntoa(packet->raw->ciaddr)); |
| 537 | return; |
| 538 | } |
| 539 | memcpy(cip.iabuf, &packet->raw->ciaddr.s_addr, 4); |
| 540 | } else |
| 541 | memcpy(cip.iabuf, &packet->client_addr.iabuf, 4); |
| 542 | |
| 543 | log_info("DHCPINFORM from %s", piaddr(cip)); |
| 544 | |
| 545 | /* Find the lease that matches the address requested by the client. */ |
| 546 | subnet = find_subnet(cip); |
| 547 | if (!subnet) |
| 548 | return; |
| 549 | |
| 550 | /* Sourceless packets don't make sense here. */ |
| 551 | if (!subnet->shared_network) { |
| 552 | log_info("Packet from unknown subnet: %s", |
| 553 | inet_ntoa(packet->raw->giaddr)); |
| 554 | return; |
| 555 | } |
| 556 | |
| 557 | /* Use a fake lease entry */ |
| 558 | memset(&lease, 0, sizeof(lease)); |
| 559 | lease.subnet = subnet; |
| 560 | lease.shared_network = subnet->shared_network; |
| 561 | |
| 562 | if (packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len) |
| 563 | lease.host = find_hosts_by_uid( |
| 564 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].data, |
| 565 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len); |
| 566 | |
| 567 | lease.starts = lease.timestamp = lease.ends = MIN_TIME0; |
| 568 | lease.flags = INFORM_NOLEASE32; |
| 569 | ack_lease(packet, &lease, DHCPACK5, 0); |
| 570 | if (lease.state != NULL((void *)0)) |
| 571 | free_lease_state(lease.state, "ack_lease"); |
| 572 | } |
| 573 | |
| 574 | void |
| 575 | nak_lease(struct packet *packet, struct iaddr *cip) |
| 576 | { |
| 577 | struct sockaddr_in to; |
| 578 | struct in_addr from; |
| 579 | ssize_t result; |
| 580 | int i; |
| 581 | struct dhcp_packet raw; |
| 582 | unsigned char nak = DHCPNAK6; |
| 583 | struct packet outgoing; |
| 584 | struct tree_cache *options[256]; |
| 585 | struct tree_cache dhcpnak_tree, dhcpmsg_tree; |
| 586 | struct tree_cache client_tree, server_tree; |
| 587 | |
| 588 | memset(options, 0, sizeof options); |
| 589 | memset(&outgoing, 0, sizeof outgoing); |
| 590 | memset(&raw, 0, sizeof raw); |
| 591 | outgoing.raw = &raw; |
| 592 | |
| 593 | /* Set DHCP_MESSAGE_TYPE to DHCPNAK */ |
| 594 | i = DHO_DHCP_MESSAGE_TYPE53; |
| 595 | options[i] = &dhcpnak_tree; |
| 596 | options[i]->value = &nak; |
| 597 | options[i]->len = sizeof nak; |
| 598 | options[i]->buf_size = sizeof nak; |
| 599 | options[i]->timeout = -1; |
| 600 | options[i]->tree = NULL((void *)0); |
| 601 | options[i]->flags = 0; |
| 602 | |
| 603 | /* Set DHCP_MESSAGE to whatever the message is */ |
| 604 | i = DHO_DHCP_MESSAGE56; |
| 605 | options[i] = &dhcpmsg_tree; |
| 606 | options[i]->value = (unsigned char *)dhcp_message; |
| 607 | options[i]->len = strlen(dhcp_message); |
| 608 | options[i]->buf_size = strlen(dhcp_message); |
| 609 | options[i]->timeout = -1; |
| 610 | options[i]->tree = NULL((void *)0); |
| 611 | options[i]->flags = 0; |
| 612 | |
| 613 | /* Include server identifier in the NAK. At least one |
| 614 | * router vendor depends on it when using dhcp relay proxy mode. |
| 615 | */ |
| 616 | i = DHO_DHCP_SERVER_IDENTIFIER54; |
| 617 | if (packet->options[i].len) { |
| 618 | options[i] = &server_tree; |
| 619 | options[i]->value = packet->options[i].data, |
| 620 | options[i]->len = packet->options[i].len; |
| 621 | options[i]->buf_size = packet->options[i].len; |
| 622 | options[i]->timeout = -1; |
| 623 | options[i]->tree = NULL((void *)0); |
| 624 | options[i]->flags = 0; |
| 625 | } |
| 626 | |
| 627 | /* Echo back the client-identifier as RFC 6842 mandates. */ |
| 628 | i = DHO_DHCP_CLIENT_IDENTIFIER61; |
| 629 | if (packet->options[i].len) { |
| 630 | options[i] = &client_tree; |
| 631 | options[i]->value = packet->options[i].data, |
| 632 | options[i]->len = packet->options[i].len; |
| 633 | options[i]->buf_size = packet->options[i].len; |
| 634 | options[i]->timeout = -1; |
| 635 | options[i]->tree = NULL((void *)0); |
| 636 | options[i]->flags = 0; |
| 637 | } |
| 638 | |
| 639 | /* Do not use the client's requested parameter list. */ |
| 640 | i = DHO_DHCP_PARAMETER_REQUEST_LIST55; |
| 641 | if (packet->options[i].data) { |
| 642 | packet->options[i].len = 0; |
| 643 | free(packet->options[i].data); |
| 644 | packet->options[i].data = NULL((void *)0); |
| 645 | } |
| 646 | |
| 647 | /* Set up the option buffer... */ |
| 648 | outgoing.packet_length = cons_options(packet, outgoing.raw, |
| 649 | 0, options, 0, 0, 0, NULL((void *)0), 0); |
| 650 | |
| 651 | /* memset(&raw.ciaddr, 0, sizeof raw.ciaddr);*/ |
| 652 | raw.siaddr = packet->interface->primary_address; |
| 653 | raw.giaddr = packet->raw->giaddr; |
| 654 | memcpy(raw.chaddr, packet->raw->chaddr, sizeof raw.chaddr); |
| 655 | raw.hlen = packet->raw->hlen; |
| 656 | raw.htype = packet->raw->htype; |
| 657 | raw.xid = packet->raw->xid; |
| 658 | raw.secs = packet->raw->secs; |
| 659 | raw.flags = packet->raw->flags | htons(BOOTP_BROADCAST)(__uint16_t)(__builtin_constant_p(32768L) ? (__uint16_t)(((__uint16_t )(32768L) & 0xffU) << 8 | ((__uint16_t)(32768L) & 0xff00U) >> 8) : __swap16md(32768L)); |
| 660 | raw.hops = packet->raw->hops; |
| 661 | raw.op = BOOTREPLY2; |
| 662 | |
| 663 | /* Report what we're sending... */ |
| 664 | log_info("DHCPNAK on %s to %s via %s", piaddr(*cip), |
| 665 | print_hw_addr(packet->raw->htype, packet->raw->hlen, |
| 666 | packet->raw->chaddr), packet->raw->giaddr.s_addr ? |
| 667 | inet_ntoa(packet->raw->giaddr) : packet->interface->name); |
| 668 | |
| 669 | /* Set up the common stuff... */ |
| 670 | memset(&to, 0, sizeof to); |
| 671 | to.sin_family = AF_INET2; |
| 672 | to.sin_len = sizeof to; |
| 673 | |
| 674 | from = packet->interface->primary_address; |
| 675 | |
| 676 | /* Make sure that the packet is at least as big as a BOOTP packet. */ |
| 677 | if (outgoing.packet_length < BOOTP_MIN_LEN300) |
| 678 | outgoing.packet_length = BOOTP_MIN_LEN300; |
| 679 | |
| 680 | /* |
| 681 | * If this was gatewayed, send it back to the gateway. |
| 682 | * Otherwise, broadcast it on the local network. |
| 683 | */ |
| 684 | if (raw.giaddr.s_addr) { |
| 685 | to.sin_addr = raw.giaddr; |
| 686 | to.sin_port = server_port; |
| 687 | |
| 688 | result = packet->interface->send_packet(packet->interface, &raw, |
| 689 | outgoing.packet_length, from, &to, packet->haddr); |
| 690 | if (result == -1) |
| 691 | log_warn("send_fallback"); |
| 692 | return; |
| 693 | } else { |
| 694 | to.sin_addr.s_addr = htonl(INADDR_BROADCAST)(__uint32_t)(__builtin_constant_p(((u_int32_t)(0xffffffff))) ? (__uint32_t)(((__uint32_t)(((u_int32_t)(0xffffffff))) & 0xff ) << 24 | ((__uint32_t)(((u_int32_t)(0xffffffff))) & 0xff00) << 8 | ((__uint32_t)(((u_int32_t)(0xffffffff)) ) & 0xff0000) >> 8 | ((__uint32_t)(((u_int32_t)(0xffffffff ))) & 0xff000000) >> 24) : __swap32md(((u_int32_t)( 0xffffffff)))); |
| 695 | to.sin_port = client_port; |
| 696 | } |
| 697 | |
| 698 | errno(*__errno()) = 0; |
| 699 | result = packet->interface->send_packet(packet->interface, &raw, |
Value stored to 'result' is never read | |
| 700 | outgoing.packet_length, from, &to, NULL((void *)0)); |
| 701 | } |
| 702 | |
| 703 | void |
| 704 | ack_lease(struct packet *packet, struct lease *lease, unsigned int offer, |
| 705 | time_t when) |
| 706 | { |
| 707 | struct lease lt; |
| 708 | struct lease_state *state; |
| 709 | time_t lease_time, offered_lease_time, max_lease_time, default_lease_time; |
| 710 | struct class *vendor_class, *user_class; |
| 711 | int ulafdr, echo_client_id, i; |
| 712 | |
| 713 | /* If we're already acking this lease, don't do it again. */ |
| 714 | if (lease->state) { |
| 715 | if ((lease->flags & STATIC_LEASE1) || |
| 716 | cur_time - lease->timestamp < 60) { |
| 717 | log_info("already acking lease %s", |
| 718 | piaddr(lease->ip_addr)); |
| 719 | return; |
| 720 | } |
| 721 | free_lease_state(lease->state, "ACK timed out"); |
| 722 | lease->state = NULL((void *)0); |
| 723 | } |
| 724 | |
| 725 | i = DHO_DHCP_CLASS_IDENTIFIER60; |
| 726 | if (packet->options[i].len) { |
| 727 | vendor_class = find_class(0, packet->options[i].data, |
| 728 | packet->options[i].len); |
| 729 | } else |
| 730 | vendor_class = NULL((void *)0); |
| 731 | |
| 732 | i = DHO_DHCP_USER_CLASS_ID77; |
| 733 | if (packet->options[i].len) { |
| 734 | user_class = find_class(1, packet->options[i].data, |
| 735 | packet->options[i].len); |
| 736 | } else |
| 737 | user_class = NULL((void *)0); |
| 738 | |
| 739 | /* |
| 740 | * If there is not a specific host entry, and either the |
| 741 | * vendor class or user class (if they exist) deny booting, |
| 742 | * then bug out. |
| 743 | */ |
| 744 | if (!lease->host) { |
| 745 | if (vendor_class && !vendor_class->group->allow_booting) { |
| 746 | log_debug("Booting denied by vendor class"); |
| 747 | return; |
| 748 | } |
| 749 | |
| 750 | if (user_class && !user_class->group->allow_booting) { |
| 751 | log_debug("Booting denied by user class"); |
| 752 | return; |
| 753 | } |
| 754 | } |
| 755 | |
| 756 | /* Allocate a lease state structure... */ |
| 757 | state = new_lease_state("ack_lease"); |
| 758 | if (!state) |
| 759 | fatalx("unable to allocate lease state!"); |
| 760 | memset(state, 0, sizeof *state); |
| 761 | state->got_requested_address = packet->got_requested_address; |
| 762 | state->shared_network = packet->interface->shared_network; |
| 763 | |
| 764 | /* Remember if we got a server identifier option. */ |
| 765 | i = DHO_DHCP_SERVER_IDENTIFIER54; |
| 766 | if (packet->options[i].len) |
| 767 | state->got_server_identifier = 1; |
| 768 | |
| 769 | /* Replace the old lease hostname with the new one, if it's changed. */ |
| 770 | i = DHO_HOST_NAME12; |
| 771 | if (packet->options[i].len && lease->client_hostname && |
| 772 | (strlen(lease->client_hostname) == packet->options[i].len) && |
| 773 | !memcmp(lease->client_hostname, packet->options[i].data, |
| 774 | packet->options[i].len)) { |
| 775 | } else if (packet->options[i].len) { |
| 776 | free(lease->client_hostname); |
| 777 | lease->client_hostname = malloc( packet->options[i].len + 1); |
| 778 | if (!lease->client_hostname) |
| 779 | fatalx("no memory for client hostname.\n"); |
| 780 | memcpy(lease->client_hostname, packet->options[i].data, |
| 781 | packet->options[i].len); |
| 782 | lease->client_hostname[packet->options[i].len] = 0; |
| 783 | } else if (lease->client_hostname) { |
| 784 | free(lease->client_hostname); |
| 785 | lease->client_hostname = 0; |
| 786 | } |
| 787 | |
| 788 | /* Replace the lease client identifier with a new one. */ |
| 789 | i = DHO_DHCP_CLIENT_IDENTIFIER61; |
| 790 | if (packet->options[i].len && lease->client_identifier && |
| 791 | lease->client_identifier_len == packet->options[i].len && |
| 792 | !memcmp(lease->client_identifier, packet->options[i].data, |
| 793 | packet->options[i].len)) { |
| 794 | /* Same client identifier. */ |
| 795 | } else if (packet->options[i].len) { |
| 796 | free(lease->client_identifier); |
| 797 | lease->client_identifier = malloc(packet->options[i].len); |
| 798 | if (!lease->client_identifier) |
| 799 | fatalx("no memory for client identifier.\n"); |
| 800 | lease->client_identifier_len = packet->options[i].len; |
| 801 | memcpy(lease->client_identifier, packet->options[i].data, |
| 802 | packet->options[i].len); |
| 803 | } else if (lease->client_identifier) { |
| 804 | free(lease->client_identifier); |
| 805 | lease->client_identifier = NULL((void *)0); |
| 806 | lease->client_identifier_len = 0; |
| 807 | } |
| 808 | |
| 809 | /* |
| 810 | * Choose a filename; first from the host_decl, if any, then from |
| 811 | * the user class, then from the vendor class. |
| 812 | */ |
| 813 | if (lease->host && lease->host->group->filename) |
| 814 | strlcpy(state->filename, lease->host->group->filename, |
| 815 | sizeof state->filename); |
| 816 | else if (user_class && user_class->group->filename) |
| 817 | strlcpy(state->filename, user_class->group->filename, |
| 818 | sizeof state->filename); |
| 819 | else if (vendor_class && vendor_class->group->filename) |
| 820 | strlcpy(state->filename, vendor_class->group->filename, |
| 821 | sizeof state->filename); |
| 822 | else if (packet->raw->file[0]) |
| 823 | strlcpy(state->filename, packet->raw->file, |
| 824 | sizeof state->filename); |
| 825 | else if (lease->subnet->group->filename) |
| 826 | strlcpy(state->filename, lease->subnet->group->filename, |
| 827 | sizeof state->filename); |
| 828 | else |
| 829 | strlcpy(state->filename, "", sizeof state->filename); |
| 830 | |
| 831 | /* Choose a server name as above. */ |
| 832 | if (lease->host && lease->host->group->server_name) |
| 833 | state->server_name = lease->host->group->server_name; |
| 834 | else if (user_class && user_class->group->server_name) |
| 835 | state->server_name = user_class->group->server_name; |
| 836 | else if (vendor_class && vendor_class->group->server_name) |
| 837 | state->server_name = vendor_class->group->server_name; |
| 838 | else if (lease->subnet->group->server_name) |
| 839 | state->server_name = lease->subnet->group->server_name; |
| 840 | else state->server_name = NULL((void *)0); |
| 841 | |
| 842 | /* |
| 843 | * At this point, we have a lease that we can offer the client. |
| 844 | * Now we construct a lease structure that contains what we want, |
| 845 | * and call supersede_lease to do the right thing with it. |
| 846 | */ |
| 847 | memset(<, 0, sizeof lt); |
| 848 | |
| 849 | /* |
| 850 | * Use the ip address of the lease that we finally found in |
| 851 | * the database. |
| 852 | */ |
| 853 | lt.ip_addr = lease->ip_addr; |
| 854 | |
| 855 | /* Start now. */ |
| 856 | lt.starts = cur_time; |
| 857 | |
| 858 | /* Figure out maximum lease time. */ |
| 859 | if (lease->host && lease->host->group->max_lease_time) |
| 860 | max_lease_time = lease->host->group->max_lease_time; |
| 861 | else |
| 862 | max_lease_time = lease->subnet->group->max_lease_time; |
| 863 | |
| 864 | /* Figure out default lease time. */ |
| 865 | if (lease->host && lease->host->group->default_lease_time) |
| 866 | default_lease_time = lease->host->group->default_lease_time; |
| 867 | else |
| 868 | default_lease_time = lease->subnet->group->default_lease_time; |
| 869 | |
| 870 | /* |
| 871 | * Figure out how long a lease to assign. If this is a |
| 872 | * dynamic BOOTP lease, its duration must be infinite. |
| 873 | */ |
| 874 | if (offer) { |
| 875 | i = DHO_DHCP_LEASE_TIME51; |
| 876 | if (packet->options[i].len == 4) { |
| 877 | lease_time = getULong( packet->options[i].data); |
| 878 | |
| 879 | /* |
| 880 | * Don't let the client ask for a longer lease than |
| 881 | * is supported for this subnet or host. |
| 882 | * |
| 883 | * time_t is signed, so really large numbers come |
| 884 | * back as negative. Don't allow lease_time of 0, |
| 885 | * either. |
| 886 | */ |
| 887 | if (lease_time < 1 || lease_time > max_lease_time) |
| 888 | lease_time = max_lease_time; |
| 889 | } else |
| 890 | lease_time = default_lease_time; |
| 891 | |
| 892 | state->offered_expiry = cur_time + lease_time; |
| 893 | if (when) |
| 894 | lt.ends = when; |
| 895 | else |
| 896 | lt.ends = state->offered_expiry; |
| 897 | } else { |
| 898 | if (lease->host && |
| 899 | lease->host->group->bootp_lease_length) |
| 900 | lt.ends = (cur_time + |
| 901 | lease->host->group->bootp_lease_length); |
| 902 | else if (lease->subnet->group->bootp_lease_length) |
| 903 | lt.ends = (cur_time + |
| 904 | lease->subnet->group->bootp_lease_length); |
| 905 | else if (lease->host && |
| 906 | lease->host->group->bootp_lease_cutoff) |
| 907 | lt.ends = lease->host->group->bootp_lease_cutoff; |
| 908 | else |
| 909 | lt.ends = lease->subnet->group->bootp_lease_cutoff; |
| 910 | state->offered_expiry = lt.ends; |
| 911 | lt.flags = BOOTP_LEASE2; |
| 912 | } |
| 913 | |
| 914 | /* Record the uid, if given... */ |
| 915 | i = DHO_DHCP_CLIENT_IDENTIFIER61; |
| 916 | if (packet->options[i].len) { |
| 917 | if (packet->options[i].len <= sizeof lt.uid_buf) { |
| 918 | memcpy(lt.uid_buf, packet->options[i].data, |
| 919 | packet->options[i].len); |
| 920 | lt.uid = lt.uid_buf; |
| 921 | lt.uid_max = sizeof lt.uid_buf; |
| 922 | lt.uid_len = packet->options[i].len; |
| 923 | } else { |
| 924 | lt.uid_max = lt.uid_len = packet->options[i].len; |
| 925 | lt.uid = malloc(lt.uid_max); |
| 926 | if (!lt.uid) |
| 927 | fatalx("can't allocate memory for large uid."); |
| 928 | memcpy(lt.uid, packet->options[i].data, lt.uid_len); |
| 929 | } |
| 930 | } |
| 931 | |
| 932 | lt.host = lease->host; |
| 933 | lt.subnet = lease->subnet; |
| 934 | lt.shared_network = lease->shared_network; |
| 935 | |
| 936 | /* Don't call supersede_lease on a mocked-up lease. */ |
| 937 | if (lease->flags & (STATIC_LEASE1 | INFORM_NOLEASE32)) { |
| 938 | /* Copy the hardware address into the static lease |
| 939 | structure. */ |
| 940 | lease->hardware_addr.hlen = packet->raw->hlen; |
| 941 | lease->hardware_addr.htype = packet->raw->htype; |
| 942 | memcpy(lease->hardware_addr.haddr, packet->raw->chaddr, |
| 943 | sizeof packet->raw->chaddr); /* XXX */ |
| 944 | } else { |
| 945 | /* Record the hardware address, if given... */ |
| 946 | lt.hardware_addr.hlen = packet->raw->hlen; |
| 947 | lt.hardware_addr.htype = packet->raw->htype; |
| 948 | memcpy(lt.hardware_addr.haddr, packet->raw->chaddr, |
| 949 | sizeof packet->raw->chaddr); |
| 950 | |
| 951 | /* Install the new information about this lease in the |
| 952 | database. If this is a DHCPACK or a dynamic BOOTREPLY |
| 953 | and we can't write the lease, don't ACK it (or BOOTREPLY |
| 954 | it) either. */ |
| 955 | |
| 956 | if (!(supersede_lease(lease, <, !offer || |
| 957 | offer == DHCPACK5) || (offer && offer != DHCPACK5))) { |
| 958 | free_lease_state(state, "ack_lease: !supersede_lease"); |
| 959 | return; |
| 960 | } |
| 961 | } |
| 962 | |
| 963 | /* Remember the interface on which the packet arrived. */ |
| 964 | state->ip = packet->interface; |
| 965 | |
| 966 | /* Set a flag if this client is a lame Microsoft client that NUL |
| 967 | terminates string options and expects us to do likewise. */ |
| 968 | i = DHO_HOST_NAME12; |
| 969 | if (packet->options[i].len && |
| 970 | packet->options[i].data[packet->options[i].len - 1] == '\0') |
| 971 | lease->flags |= MS_NULL_TERMINATION8; |
| 972 | else |
| 973 | lease->flags &= ~MS_NULL_TERMINATION8; |
| 974 | |
| 975 | /* Remember the giaddr, xid, secs, flags and hops. */ |
| 976 | state->giaddr = packet->raw->giaddr; |
| 977 | state->ciaddr = packet->raw->ciaddr; |
| 978 | state->xid = packet->raw->xid; |
| 979 | state->secs = packet->raw->secs; |
| 980 | state->bootp_flags = packet->raw->flags; |
| 981 | state->hops = packet->raw->hops; |
| 982 | state->offer = offer; |
| 983 | memcpy(&state->haddr, packet->haddr, sizeof state->haddr); |
| 984 | |
| 985 | /* Figure out what options to send to the client: */ |
| 986 | |
| 987 | /* Start out with the subnet options... */ |
| 988 | memcpy(state->options, lease->subnet->group->options, |
| 989 | sizeof state->options); |
| 990 | |
| 991 | /* Vendor and user classes are only supported for DHCP clients. */ |
| 992 | if (state->offer) { |
| 993 | /* If we have a vendor class, install those options, |
| 994 | superseding any subnet options. */ |
| 995 | if (vendor_class) { |
| 996 | for (i = 0; i < 256; i++) |
| 997 | if (vendor_class->group->options[i]) |
| 998 | state->options[i] = |
| 999 | vendor_class->group->options[i]; |
| 1000 | } |
| 1001 | |
| 1002 | /* If we have a user class, install those options, |
| 1003 | superseding any subnet and vendor class options. */ |
| 1004 | if (user_class) { |
| 1005 | for (i = 0; i < 256; i++) |
| 1006 | if (user_class->group->options[i]) |
| 1007 | state->options[i] = |
| 1008 | user_class->group->options[i]; |
| 1009 | } |
| 1010 | |
| 1011 | } |
| 1012 | |
| 1013 | /* If we have a host_decl structure, install the associated |
| 1014 | options, superseding anything that's in the way. */ |
| 1015 | if (lease->host) { |
| 1016 | for (i = 0; i < 256; i++) |
| 1017 | if (lease->host->group->options[i]) |
| 1018 | state->options[i] = |
| 1019 | lease->host->group->options[i]; |
| 1020 | } |
| 1021 | |
| 1022 | /* Get the Maximum Message Size option from the packet, if one |
| 1023 | was sent. */ |
| 1024 | i = DHO_DHCP_MAX_MESSAGE_SIZE57; |
| 1025 | if (packet->options[i].data && |
| 1026 | packet->options[i].len == sizeof(u_int16_t)) |
| 1027 | state->max_message_size = getUShort(packet->options[i].data); |
| 1028 | /* Otherwise, if a maximum message size was specified, use that. */ |
| 1029 | else if (state->options[i] && state->options[i]->value) |
| 1030 | state->max_message_size = getUShort(state->options[i]->value); |
| 1031 | |
| 1032 | /* Save the parameter request list if there is one. */ |
| 1033 | i = DHO_DHCP_PARAMETER_REQUEST_LIST55; |
| 1034 | if (packet->options[i].data) { |
| 1035 | state->prl = calloc(1, packet->options[i].len); |
| 1036 | if (!state->prl) |
| 1037 | log_warnx("no memory for parameter request list"); |
| 1038 | else { |
| 1039 | memcpy(state->prl, packet->options[i].data, |
| 1040 | packet->options[i].len); |
| 1041 | state->prl_len = packet->options[i].len; |
| 1042 | } |
| 1043 | } |
| 1044 | |
| 1045 | /* If we didn't get a hostname from an option somewhere, see if |
| 1046 | we can get one from the lease. */ |
| 1047 | i = DHO_HOST_NAME12; |
| 1048 | if (!state->options[i] && lease->hostname) { |
| 1049 | state->options[i] = new_tree_cache("hostname"); |
| 1050 | state->options[i]->flags = TC_TEMPORARY2; |
| 1051 | state->options[i]->value = (unsigned char *)lease->hostname; |
| 1052 | state->options[i]->len = strlen(lease->hostname); |
| 1053 | state->options[i]->buf_size = state->options[i]->len; |
| 1054 | state->options[i]->timeout = -1; |
| 1055 | state->options[i]->tree = NULL((void *)0); |
| 1056 | } |
| 1057 | |
| 1058 | /* |
| 1059 | * Now, if appropriate, put in DHCP-specific options that |
| 1060 | * override those. |
| 1061 | */ |
| 1062 | if (state->offer) { |
| 1063 | i = DHO_DHCP_MESSAGE_TYPE53; |
| 1064 | state->options[i] = new_tree_cache("message-type"); |
| 1065 | state->options[i]->flags = TC_TEMPORARY2; |
| 1066 | state->options[i]->value = &state->offer; |
| 1067 | state->options[i]->len = sizeof state->offer; |
| 1068 | state->options[i]->buf_size = sizeof state->offer; |
| 1069 | state->options[i]->timeout = -1; |
| 1070 | state->options[i]->tree = NULL((void *)0); |
| 1071 | |
| 1072 | i = DHO_DHCP_SERVER_IDENTIFIER54; |
| 1073 | if (!state->options[i]) { |
| 1074 | use_primary: |
| 1075 | state->options[i] = new_tree_cache("server-id"); |
| 1076 | state->options[i]->value = |
| 1077 | (unsigned char *)&state->ip->primary_address; |
| 1078 | state->options[i]->len = |
| 1079 | sizeof state->ip->primary_address; |
| 1080 | state->options[i]->buf_size = state->options[i]->len; |
| 1081 | state->options[i]->timeout = -1; |
| 1082 | state->options[i]->tree = NULL((void *)0); |
| 1083 | state->from.len = sizeof state->ip->primary_address; |
| 1084 | memcpy(state->from.iabuf, &state->ip->primary_address, |
| 1085 | state->from.len); |
| 1086 | } else { |
| 1087 | /* Find the value of the server identifier... */ |
| 1088 | if (!tree_evaluate(state->options[i])) |
| 1089 | goto use_primary; |
| 1090 | if (!state->options[i]->value || |
| 1091 | (state->options[i]->len > |
| 1092 | sizeof state->from.iabuf)) |
| 1093 | goto use_primary; |
| 1094 | |
| 1095 | state->from.len = state->options[i]->len; |
| 1096 | memcpy(state->from.iabuf, state->options[i]->value, |
| 1097 | state->from.len); |
| 1098 | } |
| 1099 | /* |
| 1100 | * Do not ACK a REQUEST intended for another server. |
| 1101 | */ |
| 1102 | if (packet->options[i].len == 4) { |
| 1103 | if (state->options[i]->len != 4 || |
| 1104 | memcmp(packet->options[i].data, |
| 1105 | state->options[i]->value, 4) != 0) { |
| 1106 | free_lease_state(state, "ack_lease: " |
| 1107 | "server identifier"); |
| 1108 | return; |
| 1109 | } |
| 1110 | } |
| 1111 | |
| 1112 | /* If we used the vendor class the client specified, we |
| 1113 | have to return it. */ |
| 1114 | if (vendor_class) { |
| 1115 | i = DHO_DHCP_CLASS_IDENTIFIER60; |
| 1116 | state->options[i] = new_tree_cache("class-identifier"); |
| 1117 | state->options[i]->flags = TC_TEMPORARY2; |
| 1118 | state->options[i]->value = |
| 1119 | (unsigned char *)vendor_class->name; |
| 1120 | state->options[i]->len = strlen(vendor_class->name); |
| 1121 | state->options[i]->buf_size = state->options[i]->len; |
| 1122 | state->options[i]->timeout = -1; |
| 1123 | state->options[i]->tree = NULL((void *)0); |
| 1124 | } |
| 1125 | |
| 1126 | /* If we used the user class the client specified, we |
| 1127 | have to return it. */ |
| 1128 | if (user_class) { |
| 1129 | i = DHO_DHCP_USER_CLASS_ID77; |
| 1130 | state->options[i] = new_tree_cache("user-class"); |
| 1131 | state->options[i]->flags = TC_TEMPORARY2; |
| 1132 | state->options[i]->value = |
| 1133 | (unsigned char *)user_class->name; |
| 1134 | state->options[i]->len = strlen(user_class->name); |
| 1135 | state->options[i]->buf_size = state->options[i]->len; |
| 1136 | state->options[i]->timeout = -1; |
| 1137 | state->options[i]->tree = NULL((void *)0); |
| 1138 | } |
| 1139 | } |
| 1140 | |
| 1141 | /* for DHCPINFORM, don't include lease time parameters */ |
| 1142 | if (state->offer && (lease->flags & INFORM_NOLEASE32) == 0) { |
| 1143 | |
| 1144 | /* Sanity check the lease time. */ |
| 1145 | if ((state->offered_expiry - cur_time) < 15) |
| 1146 | offered_lease_time = default_lease_time; |
| 1147 | else if (state->offered_expiry - cur_time > max_lease_time) |
| 1148 | offered_lease_time = max_lease_time; |
| 1149 | else |
| 1150 | offered_lease_time = |
| 1151 | state->offered_expiry - cur_time; |
| 1152 | |
| 1153 | putULong((unsigned char *)&state->expiry, offered_lease_time); |
| 1154 | i = DHO_DHCP_LEASE_TIME51; |
| 1155 | state->options[i] = new_tree_cache("lease-expiry"); |
| 1156 | state->options[i]->flags = TC_TEMPORARY2; |
| 1157 | state->options[i]->value = (unsigned char *)&state->expiry; |
| 1158 | state->options[i]->len = sizeof state->expiry; |
| 1159 | state->options[i]->buf_size = sizeof state->expiry; |
| 1160 | state->options[i]->timeout = -1; |
| 1161 | state->options[i]->tree = NULL((void *)0); |
| 1162 | |
| 1163 | /* Renewal time is lease time * 0.5. */ |
| 1164 | offered_lease_time /= 2; |
| 1165 | putULong((unsigned char *)&state->renewal, offered_lease_time); |
| 1166 | i = DHO_DHCP_RENEWAL_TIME58; |
| 1167 | state->options[i] = new_tree_cache("renewal-time"); |
| 1168 | state->options[i]->flags = TC_TEMPORARY2; |
| 1169 | state->options[i]->value = |
| 1170 | (unsigned char *)&state->renewal; |
| 1171 | state->options[i]->len = sizeof state->renewal; |
| 1172 | state->options[i]->buf_size = sizeof state->renewal; |
| 1173 | state->options[i]->timeout = -1; |
| 1174 | state->options[i]->tree = NULL((void *)0); |
| 1175 | |
| 1176 | |
| 1177 | /* Rebinding time is lease time * 0.875. */ |
| 1178 | offered_lease_time += (offered_lease_time / 2 + |
| 1179 | offered_lease_time / 4); |
| 1180 | putULong((unsigned char *)&state->rebind, offered_lease_time); |
| 1181 | i = DHO_DHCP_REBINDING_TIME59; |
| 1182 | state->options[i] = new_tree_cache("rebind-time"); |
| 1183 | state->options[i]->flags = TC_TEMPORARY2; |
| 1184 | state->options[i]->value = (unsigned char *)&state->rebind; |
| 1185 | state->options[i]->len = sizeof state->rebind; |
| 1186 | state->options[i]->buf_size = sizeof state->rebind; |
| 1187 | state->options[i]->timeout = -1; |
| 1188 | state->options[i]->tree = NULL((void *)0); |
| 1189 | } |
| 1190 | |
| 1191 | /* Use the subnet mask from the subnet declaration if no other |
| 1192 | mask has been provided. */ |
| 1193 | i = DHO_SUBNET_MASK1; |
| 1194 | if (!state->options[i]) { |
| 1195 | state->options[i] = new_tree_cache("subnet-mask"); |
| 1196 | state->options[i]->flags = TC_TEMPORARY2; |
| 1197 | state->options[i]->value = lease->subnet->netmask.iabuf; |
| 1198 | state->options[i]->len = lease->subnet->netmask.len; |
| 1199 | state->options[i]->buf_size = lease->subnet->netmask.len; |
| 1200 | state->options[i]->timeout = -1; |
| 1201 | state->options[i]->tree = NULL((void *)0); |
| 1202 | } |
| 1203 | |
| 1204 | /* If so directed, use the leased IP address as the router address. |
| 1205 | This supposedly makes Win95 machines ARP for all IP addresses, |
| 1206 | so if the local router does proxy arp, you win. */ |
| 1207 | |
| 1208 | ulafdr = 0; |
| 1209 | if (lease->host) { |
| 1210 | if (lease->host->group->use_lease_addr_for_default_route) |
| 1211 | ulafdr = 1; |
| 1212 | } else if (user_class) { |
| 1213 | if (user_class->group->use_lease_addr_for_default_route) |
| 1214 | ulafdr = 1; |
| 1215 | } else if (vendor_class) { |
| 1216 | if (vendor_class->group->use_lease_addr_for_default_route) |
| 1217 | ulafdr = 1; |
| 1218 | } else if (lease->subnet->group->use_lease_addr_for_default_route) |
| 1219 | ulafdr = 1; |
| 1220 | else |
| 1221 | ulafdr = 0; |
| 1222 | |
| 1223 | i = DHO_ROUTERS3; |
| 1224 | if (ulafdr && !state->options[i]) { |
| 1225 | state->options[i] = new_tree_cache("routers"); |
| 1226 | state->options[i]->flags = TC_TEMPORARY2; |
| 1227 | state->options[i]->value = lease->ip_addr.iabuf; |
| 1228 | state->options[i]->len = lease->ip_addr.len; |
| 1229 | state->options[i]->buf_size = lease->ip_addr.len; |
| 1230 | state->options[i]->timeout = -1; |
| 1231 | state->options[i]->tree = NULL((void *)0); |
| 1232 | } |
| 1233 | |
| 1234 | /* |
| 1235 | * RFC 3046: MUST NOT echo relay agent information if the server |
| 1236 | * does not understand/use the data. We don't. |
| 1237 | */ |
| 1238 | i = DHO_RELAY_AGENT_INFORMATION82; |
| 1239 | memset(&state->options[i], 0, sizeof(state->options[i])); |
| 1240 | |
| 1241 | /* Echo back the client-identifier as RFC 6842 mandates. */ |
| 1242 | if (lease->host) |
| 1243 | echo_client_id = lease->host->group->echo_client_id; |
| 1244 | else if (user_class) |
| 1245 | echo_client_id = user_class->group->echo_client_id; |
| 1246 | else if (vendor_class) |
| 1247 | echo_client_id = vendor_class->group->echo_client_id; |
| 1248 | else |
| 1249 | echo_client_id = lease->subnet->group->echo_client_id; |
| 1250 | i = DHO_DHCP_CLIENT_IDENTIFIER61; |
| 1251 | if (lease->client_identifier && echo_client_id) { |
| 1252 | state->options[i] = new_tree_cache("dhcp-client-identifier"); |
| 1253 | state->options[i]->flags = TC_TEMPORARY2; |
| 1254 | state->options[i]->value = lease->client_identifier; |
| 1255 | state->options[i]->len = lease->client_identifier_len; |
| 1256 | state->options[i]->buf_size = lease->client_identifier_len; |
| 1257 | state->options[i]->timeout = -1; |
| 1258 | state->options[i]->tree = NULL((void *)0); |
| 1259 | } else |
| 1260 | memset(&state->options[i], 0, sizeof(state->options[i])); |
| 1261 | |
| 1262 | lease->state = state; |
| 1263 | |
| 1264 | /* If this is a DHCPOFFER, ping the lease address before actually |
| 1265 | sending the offer. */ |
| 1266 | if (offer == DHCPOFFER2 && !(lease->flags & STATIC_LEASE1) && |
| 1267 | cur_time - lease->timestamp > 60) { |
| 1268 | lease->timestamp = cur_time; |
| 1269 | icmp_echorequest(&lease->ip_addr); |
| 1270 | add_timeout(cur_time + 1, lease_ping_timeout, lease); |
| 1271 | ++outstanding_pings; |
| 1272 | } else { |
| 1273 | lease->timestamp = cur_time; |
| 1274 | dhcp_reply(lease); |
| 1275 | } |
| 1276 | } |
| 1277 | |
| 1278 | void |
| 1279 | dhcp_reply(struct lease *lease) |
| 1280 | { |
| 1281 | char ciaddrbuf[INET_ADDRSTRLEN16]; |
| 1282 | int bufs = 0, packet_length, i; |
| 1283 | struct dhcp_packet raw; |
| 1284 | struct sockaddr_in to; |
| 1285 | struct in_addr from; |
| 1286 | struct lease_state *state = lease->state; |
| 1287 | int nulltp, bootpp; |
| 1288 | u_int8_t *prl; |
| 1289 | int prl_len; |
| 1290 | |
| 1291 | if (!state) |
| 1292 | fatalx("dhcp_reply was supplied lease with no state!"); |
| 1293 | |
| 1294 | /* Compose a response for the client... */ |
| 1295 | memset(&raw, 0, sizeof raw); |
| 1296 | |
| 1297 | /* Copy in the filename if given; otherwise, flag the filename |
| 1298 | buffer as available for options. */ |
| 1299 | if (state->filename[0]) |
| 1300 | strlcpy(raw.file, state->filename, sizeof raw.file); |
| 1301 | else |
| 1302 | bufs |= 1; |
| 1303 | |
| 1304 | /* Copy in the server name if given; otherwise, flag the |
| 1305 | server_name buffer as available for options. */ |
| 1306 | if (state->server_name) |
| 1307 | strlcpy(raw.sname, state->server_name, sizeof raw.sname); |
| 1308 | else |
| 1309 | bufs |= 2; /* XXX */ |
| 1310 | |
| 1311 | memcpy(raw.chaddr, lease->hardware_addr.haddr, sizeof raw.chaddr); |
| 1312 | raw.hlen = lease->hardware_addr.hlen; |
| 1313 | raw.htype = lease->hardware_addr.htype; |
| 1314 | |
| 1315 | /* See if this is a Microsoft client that NUL-terminates its |
| 1316 | strings and expects us to do likewise... */ |
| 1317 | if (lease->flags & MS_NULL_TERMINATION8) |
| 1318 | nulltp = 1; |
| 1319 | else |
| 1320 | nulltp = 0; |
| 1321 | |
| 1322 | /* See if this is a bootp client... */ |
| 1323 | if (state->offer) |
| 1324 | bootpp = 0; |
| 1325 | else |
| 1326 | bootpp = 1; |
| 1327 | |
| 1328 | if (state->options[DHO_DHCP_PARAMETER_REQUEST_LIST55] && |
| 1329 | state->options[DHO_DHCP_PARAMETER_REQUEST_LIST55]->value) { |
| 1330 | prl = state->options[DHO_DHCP_PARAMETER_REQUEST_LIST55]->value; |
| 1331 | prl_len = state->options[DHO_DHCP_PARAMETER_REQUEST_LIST55]->len; |
| 1332 | } else if (state->prl) { |
| 1333 | prl = state->prl; |
| 1334 | prl_len = state->prl_len; |
| 1335 | } else { |
| 1336 | prl = NULL((void *)0); |
| 1337 | prl_len = 0; |
| 1338 | } |
| 1339 | |
| 1340 | /* Insert such options as will fit into the buffer. */ |
| 1341 | packet_length = cons_options(NULL((void *)0), &raw, state->max_message_size, |
| 1342 | state->options, bufs, nulltp, bootpp, prl, prl_len); |
| 1343 | |
| 1344 | /* Having done the cons_options(), we can release the tree_cache |
| 1345 | entries. */ |
| 1346 | for (i = 0; i < 256; i++) { |
| 1347 | if (state->options[i] && |
| 1348 | state->options[i]->flags & TC_TEMPORARY2) |
| 1349 | free_tree_cache(state->options[i]); |
| 1350 | } |
| 1351 | |
| 1352 | memcpy(&raw.ciaddr, &state->ciaddr, sizeof raw.ciaddr); |
| 1353 | if ((lease->flags & INFORM_NOLEASE32) == 0) |
| 1354 | memcpy(&raw.yiaddr, lease->ip_addr.iabuf, 4); |
| 1355 | |
| 1356 | /* Figure out the address of the next server. */ |
| 1357 | if (lease->host && lease->host->group->next_server.len) |
| 1358 | memcpy(&raw.siaddr, lease->host->group->next_server.iabuf, 4); |
| 1359 | else if (lease->subnet->group->next_server.len) |
| 1360 | memcpy(&raw.siaddr, lease->subnet->group->next_server.iabuf, |
| 1361 | 4); |
| 1362 | else if (lease->subnet->interface_address.len) |
| 1363 | memcpy(&raw.siaddr, lease->subnet->interface_address.iabuf, 4); |
| 1364 | else |
| 1365 | raw.siaddr = state->ip->primary_address; |
| 1366 | |
| 1367 | raw.giaddr = state->giaddr; |
| 1368 | |
| 1369 | raw.xid = state->xid; |
| 1370 | raw.secs = state->secs; |
| 1371 | raw.flags = state->bootp_flags; |
| 1372 | raw.hops = state->hops; |
| 1373 | raw.op = BOOTREPLY2; |
| 1374 | |
| 1375 | /* Can't do >1 inet_ntoa() in a printf()! */ |
| 1376 | strlcpy(ciaddrbuf, inet_ntoa(state->ciaddr), sizeof(ciaddrbuf)); |
| 1377 | |
| 1378 | /* Say what we're doing... */ |
| 1379 | if ((state->offer == DHCPACK5) && (lease->flags & INFORM_NOLEASE32)) |
| 1380 | log_info("DHCPACK to %s (%s) via %s", |
| 1381 | ciaddrbuf, |
| 1382 | print_hw_addr(lease->hardware_addr.htype, |
| 1383 | lease->hardware_addr.hlen, lease->hardware_addr.haddr), |
| 1384 | state->giaddr.s_addr ? inet_ntoa(state->giaddr) : |
| 1385 | state->ip->name); |
| 1386 | else |
| 1387 | log_info("%s on %s to %s via %s", |
| 1388 | (state->offer ? (state->offer == DHCPACK5 ? "DHCPACK" : |
| 1389 | "DHCPOFFER") : "BOOTREPLY"), |
| 1390 | piaddr(lease->ip_addr), |
| 1391 | print_hw_addr(lease->hardware_addr.htype, |
| 1392 | lease->hardware_addr.hlen, lease->hardware_addr.haddr), |
| 1393 | state->giaddr.s_addr ? inet_ntoa(state->giaddr) : |
| 1394 | state->ip->name); |
| 1395 | |
| 1396 | memset(&to, 0, sizeof to); |
| 1397 | to.sin_family = AF_INET2; |
| 1398 | #ifdef HAVE_SA_LEN |
| 1399 | to.sin_len = sizeof to; |
| 1400 | #endif |
| 1401 | |
| 1402 | /* Make sure outgoing packets are at least as big |
| 1403 | as a BOOTP packet. */ |
| 1404 | if (packet_length < BOOTP_MIN_LEN300) |
| 1405 | packet_length = BOOTP_MIN_LEN300; |
| 1406 | |
| 1407 | /* If this was gatewayed, send it back to the gateway... */ |
| 1408 | if (raw.giaddr.s_addr) { |
| 1409 | to.sin_addr = raw.giaddr; |
| 1410 | to.sin_port = server_port; |
| 1411 | |
| 1412 | memcpy(&from, state->from.iabuf, sizeof from); |
| 1413 | |
| 1414 | (void) state->ip->send_packet(state->ip, &raw, |
| 1415 | packet_length, from, &to, &state->haddr); |
| 1416 | |
| 1417 | free_lease_state(state, "dhcp_reply gateway"); |
| 1418 | lease->state = NULL((void *)0); |
| 1419 | return; |
| 1420 | |
| 1421 | /* If the client is RENEWING, unicast to the client using the |
| 1422 | regular IP stack. Some clients, particularly those that |
| 1423 | follow RFC1541, are buggy, and send both ciaddr and |
| 1424 | server-identifier. We deal with this situation by assuming |
| 1425 | that if we got both dhcp-server-identifier and ciaddr, and |
| 1426 | giaddr was not set, then the client is on the local |
| 1427 | network, and we can therefore unicast or broadcast to it |
| 1428 | successfully. A client in REQUESTING state on another |
| 1429 | network that's making this mistake will have set giaddr, |
| 1430 | and will therefore get a relayed response from the above |
| 1431 | code. */ |
| 1432 | } else if (raw.ciaddr.s_addr && |
| 1433 | !((state->got_server_identifier || |
| 1434 | (raw.flags & htons(BOOTP_BROADCAST)(__uint16_t)(__builtin_constant_p(32768L) ? (__uint16_t)(((__uint16_t )(32768L) & 0xffU) << 8 | ((__uint16_t)(32768L) & 0xff00U) >> 8) : __swap16md(32768L)))) && |
| 1435 | /* XXX This won't work if giaddr isn't zero, but it is: */ |
| 1436 | (state->shared_network == lease->shared_network)) && |
| 1437 | state->offer == DHCPACK5) { |
| 1438 | to.sin_addr = raw.ciaddr; |
| 1439 | to.sin_port = client_port; |
| 1440 | |
| 1441 | /* If it comes from a client that already knows its address |
| 1442 | and is not requesting a broadcast response, and we can |
| 1443 | unicast to a client without using the ARP protocol, sent it |
| 1444 | directly to that client. */ |
| 1445 | } else if (!(raw.flags & htons(BOOTP_BROADCAST)(__uint16_t)(__builtin_constant_p(32768L) ? (__uint16_t)(((__uint16_t )(32768L) & 0xffU) << 8 | ((__uint16_t)(32768L) & 0xff00U) >> 8) : __swap16md(32768L)))) { |
| 1446 | to.sin_addr = raw.yiaddr; |
| 1447 | to.sin_port = client_port; |
| 1448 | |
| 1449 | /* Otherwise, broadcast it on the local network. */ |
| 1450 | } else { |
| 1451 | to.sin_addr.s_addr = htonl(INADDR_BROADCAST)(__uint32_t)(__builtin_constant_p(((u_int32_t)(0xffffffff))) ? (__uint32_t)(((__uint32_t)(((u_int32_t)(0xffffffff))) & 0xff ) << 24 | ((__uint32_t)(((u_int32_t)(0xffffffff))) & 0xff00) << 8 | ((__uint32_t)(((u_int32_t)(0xffffffff)) ) & 0xff0000) >> 8 | ((__uint32_t)(((u_int32_t)(0xffffffff ))) & 0xff000000) >> 24) : __swap32md(((u_int32_t)( 0xffffffff)))); |
| 1452 | to.sin_port = client_port; |
| 1453 | memset(&state->haddr, 0xff, sizeof state->haddr); |
| 1454 | } |
| 1455 | |
| 1456 | memcpy(&from, state->from.iabuf, sizeof from); |
| 1457 | |
| 1458 | (void) state->ip->send_packet(state->ip, &raw, packet_length, |
| 1459 | from, &to, &state->haddr); |
| 1460 | |
| 1461 | free_lease_state(state, "dhcp_reply"); |
| 1462 | lease->state = NULL((void *)0); |
| 1463 | } |
| 1464 | |
| 1465 | struct lease * |
| 1466 | find_lease(struct packet *packet, struct shared_network *share, |
| 1467 | int *ours) |
| 1468 | { |
| 1469 | struct lease *uid_lease, *ip_lease, *hw_lease; |
| 1470 | struct lease *lease = NULL((void *)0); |
| 1471 | struct iaddr cip; |
| 1472 | struct host_decl *hp, *host = NULL((void *)0); |
| 1473 | struct lease *fixed_lease; |
| 1474 | |
| 1475 | /* Figure out what IP address the client is requesting, if any. */ |
| 1476 | if (packet->options[DHO_DHCP_REQUESTED_ADDRESS50].len == 4) { |
| 1477 | packet->got_requested_address = 1; |
| 1478 | cip.len = 4; |
| 1479 | memcpy(cip.iabuf, |
| 1480 | packet->options[DHO_DHCP_REQUESTED_ADDRESS50].data, |
| 1481 | cip.len); |
| 1482 | } else if (packet->raw->ciaddr.s_addr) { |
| 1483 | cip.len = 4; |
| 1484 | memcpy(cip.iabuf, &packet->raw->ciaddr, 4); |
| 1485 | } else |
| 1486 | cip.len = 0; |
| 1487 | |
| 1488 | /* Try to find a host or lease that's been assigned to the |
| 1489 | specified unique client identifier. */ |
| 1490 | if (packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len) { |
| 1491 | /* First, try to find a fixed host entry for the specified |
| 1492 | client identifier... */ |
| 1493 | hp = find_hosts_by_uid( |
| 1494 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].data, |
| 1495 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len); |
| 1496 | if (hp) { |
| 1497 | host = hp; |
| 1498 | fixed_lease = mockup_lease(packet, share, hp); |
| 1499 | uid_lease = NULL((void *)0); |
| 1500 | } else { |
| 1501 | uid_lease = find_lease_by_uid( |
| 1502 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].data, |
| 1503 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len); |
| 1504 | /* Find the lease matching this uid that's on the |
| 1505 | network the packet came from (if any). */ |
| 1506 | for (; uid_lease; uid_lease = uid_lease->n_uid) |
| 1507 | if (uid_lease->shared_network == share) |
| 1508 | break; |
| 1509 | fixed_lease = NULL((void *)0); |
| 1510 | if (uid_lease && (uid_lease->flags & ABANDONED_LEASE16)) |
| 1511 | uid_lease = NULL((void *)0); |
| 1512 | } |
| 1513 | } else { |
| 1514 | uid_lease = NULL((void *)0); |
| 1515 | fixed_lease = NULL((void *)0); |
| 1516 | } |
| 1517 | |
| 1518 | /* If we didn't find a fixed lease using the uid, try doing |
| 1519 | it with the hardware address... */ |
| 1520 | if (!fixed_lease) { |
| 1521 | hp = find_hosts_by_haddr(packet->raw->htype, |
| 1522 | packet->raw->chaddr, packet->raw->hlen); |
| 1523 | if (hp) { |
| 1524 | host = hp; /* Save it for later. */ |
| 1525 | fixed_lease = mockup_lease(packet, share, hp); |
| 1526 | } |
| 1527 | } |
| 1528 | |
| 1529 | /* If fixed_lease is present but does not match the requested |
| 1530 | IP address, and this is a DHCPREQUEST, then we can't return |
| 1531 | any other lease, so we might as well return now. */ |
| 1532 | if (packet->packet_type == DHCPREQUEST3 && fixed_lease && |
| 1533 | (fixed_lease->ip_addr.len != cip.len || |
| 1534 | memcmp(fixed_lease->ip_addr.iabuf, cip.iabuf, cip.len))) { |
| 1535 | if (ours) |
| 1536 | *ours = 1; |
| 1537 | strlcpy(dhcp_message, "requested address is incorrect", |
| 1538 | sizeof(dhcp_message)); |
| 1539 | return NULL((void *)0); |
| 1540 | } |
| 1541 | |
| 1542 | /* Try to find a lease that's been attached to the client's |
| 1543 | hardware address... */ |
| 1544 | hw_lease = find_lease_by_hw_addr(packet->raw->chaddr, |
| 1545 | packet->raw->hlen); |
| 1546 | /* Find the lease that's on the network the packet came from |
| 1547 | (if any). */ |
| 1548 | for (; hw_lease; hw_lease = hw_lease->n_hw) { |
| 1549 | if (hw_lease->shared_network == share) { |
| 1550 | if ((hw_lease->flags & ABANDONED_LEASE16)) |
| 1551 | continue; |
| 1552 | if (packet->packet_type) |
| 1553 | break; |
| 1554 | if (hw_lease->flags & |
| 1555 | (BOOTP_LEASE2 | DYNAMIC_BOOTP_OK4)) |
| 1556 | break; |
| 1557 | } |
| 1558 | } |
| 1559 | |
| 1560 | /* Try to find a lease that's been allocated to the client's |
| 1561 | IP address. */ |
| 1562 | if (cip.len) |
| 1563 | ip_lease = find_lease_by_ip_addr(cip); |
| 1564 | else |
| 1565 | ip_lease = NULL((void *)0); |
| 1566 | |
| 1567 | /* If ip_lease is valid at this point, set ours to one, so that |
| 1568 | even if we choose a different lease, we know that the address |
| 1569 | the client was requesting was ours, and thus we can NAK it. */ |
| 1570 | if (ip_lease && ours) |
| 1571 | *ours = 1; |
| 1572 | |
| 1573 | /* If the requested IP address isn't on the network the packet |
| 1574 | came from, don't use it. Allow abandoned leases to be matched |
| 1575 | here - if the client is requesting it, there's a decent chance |
| 1576 | that it's because the lease database got trashed and a client |
| 1577 | that thought it had this lease answered an ARP or PING, causing the |
| 1578 | lease to be abandoned. If so, this request probably came from |
| 1579 | that client. */ |
| 1580 | if (ip_lease && (ip_lease->shared_network != share)) { |
| 1581 | ip_lease = NULL((void *)0); |
| 1582 | strlcpy(dhcp_message, "requested address on bad subnet", |
| 1583 | sizeof(dhcp_message)); |
| 1584 | } |
| 1585 | |
| 1586 | /* Toss ip_lease if it hasn't yet expired and isn't owned by the |
| 1587 | client. */ |
| 1588 | if (ip_lease && ip_lease->ends >= cur_time && ip_lease != uid_lease) { |
| 1589 | int i = DHO_DHCP_CLIENT_IDENTIFIER61; |
| 1590 | |
| 1591 | /* Make sure that ip_lease actually belongs to the client, |
| 1592 | and toss it if not. */ |
| 1593 | if ((ip_lease->uid_len && packet->options[i].data && |
| 1594 | ip_lease->uid_len == packet->options[i].len && |
| 1595 | !memcmp(packet->options[i].data, ip_lease->uid, |
| 1596 | ip_lease->uid_len)) || |
| 1597 | (!ip_lease->uid_len && |
| 1598 | ip_lease->hardware_addr.htype == packet->raw->htype && |
| 1599 | ip_lease->hardware_addr.hlen == packet->raw->hlen && |
| 1600 | !memcmp(ip_lease->hardware_addr.haddr, packet->raw->chaddr, |
| 1601 | ip_lease->hardware_addr.hlen))) { |
| 1602 | if (uid_lease) { |
| 1603 | if (uid_lease->ends > cur_time) { |
| 1604 | log_warnx("client %s has duplicate " |
| 1605 | "leases on %s", |
| 1606 | print_hw_addr(packet->raw->htype, |
| 1607 | packet->raw->hlen, |
| 1608 | packet->raw->chaddr), |
| 1609 | ip_lease->shared_network->name); |
| 1610 | |
| 1611 | if (uid_lease && |
| 1612 | !packet->raw->ciaddr.s_addr) |
| 1613 | release_lease(uid_lease); |
| 1614 | } |
| 1615 | uid_lease = ip_lease; |
| 1616 | } |
| 1617 | } else { |
| 1618 | strlcpy(dhcp_message, "requested address is not " |
| 1619 | "available", sizeof(dhcp_message)); |
| 1620 | ip_lease = NULL((void *)0); |
| 1621 | } |
| 1622 | |
| 1623 | /* If we get to here and fixed_lease is not null, that means |
| 1624 | that there are both a dynamic lease and a fixed-address |
| 1625 | declaration for the same IP address. */ |
| 1626 | if (packet->packet_type == DHCPREQUEST3 && fixed_lease) { |
| 1627 | fixed_lease = NULL((void *)0); |
| 1628 | db_conflict: |
| 1629 | log_warnx("Both dynamic and static leases present for " |
| 1630 | "%s.", piaddr(cip)); |
| 1631 | log_warnx("Either remove host declaration %s or " |
| 1632 | "remove %s", (fixed_lease && fixed_lease->host ? |
| 1633 | (fixed_lease->host->name ? |
| 1634 | fixed_lease->host->name : piaddr(cip)) : |
| 1635 | piaddr(cip)), piaddr(cip)); |
| 1636 | log_warnx("from the dynamic address pool for %s", |
| 1637 | share->name); |
| 1638 | if (fixed_lease) |
| 1639 | ip_lease = NULL((void *)0); |
| 1640 | strlcpy(dhcp_message, "database conflict - call for " |
| 1641 | "help!", sizeof(dhcp_message)); |
| 1642 | } |
| 1643 | } |
| 1644 | |
| 1645 | /* If we get to here with both fixed_lease and ip_lease not |
| 1646 | null, then we have a configuration file bug. */ |
| 1647 | if (packet->packet_type == DHCPREQUEST3 && fixed_lease && ip_lease) |
| 1648 | goto db_conflict; |
| 1649 | |
| 1650 | /* Toss hw_lease if it hasn't yet expired and the uid doesn't |
| 1651 | match, except that if the hardware address matches and the |
| 1652 | client is now doing dynamic BOOTP (and thus hasn't provided |
| 1653 | a uid) we let the client get away with it. */ |
| 1654 | if (hw_lease && hw_lease->ends >= cur_time && hw_lease->uid && |
| 1655 | packet->options[DHO_DHCP_CLIENT_IDENTIFIER61].len && |
| 1656 | hw_lease != uid_lease) |
| 1657 | hw_lease = NULL((void *)0); |
| 1658 | |
| 1659 | /* Toss extra pointers to the same lease... */ |
| 1660 | if (hw_lease == uid_lease) |
| 1661 | hw_lease = NULL((void *)0); |
| 1662 | if (ip_lease == hw_lease) |
| 1663 | hw_lease = NULL((void *)0); |
| 1664 | if (ip_lease == uid_lease) |
| 1665 | uid_lease = NULL((void *)0); |
| 1666 | |
| 1667 | /* If we've already eliminated the lease, it wasn't there to |
| 1668 | begin with. If we have come up with a matching lease, |
| 1669 | set the message to bad network in case we have to throw it out. */ |
| 1670 | if (!ip_lease) { |
| 1671 | strlcpy(dhcp_message, "requested address not available", |
| 1672 | sizeof(dhcp_message)); |
| 1673 | } |
| 1674 | |
| 1675 | /* Now eliminate leases that are on the wrong network... */ |
| 1676 | if (ip_lease && share != ip_lease->shared_network) { |
| 1677 | if (packet->packet_type == DHCPREQUEST3) |
| 1678 | release_lease(ip_lease); |
| 1679 | ip_lease = NULL((void *)0); |
| 1680 | } |
| 1681 | if (uid_lease && share != uid_lease->shared_network) { |
| 1682 | if (packet->packet_type == DHCPREQUEST3) |
| 1683 | release_lease(uid_lease); |
| 1684 | uid_lease = NULL((void *)0); |
| 1685 | } |
| 1686 | if (hw_lease && share != hw_lease->shared_network) { |
| 1687 | if (packet->packet_type == DHCPREQUEST3) |
| 1688 | release_lease(hw_lease); |
| 1689 | hw_lease = NULL((void *)0); |
| 1690 | } |
| 1691 | |
| 1692 | /* If this is a DHCPREQUEST, make sure the lease we're going to return |
| 1693 | matches the requested IP address. If it doesn't, don't return a |
| 1694 | lease at all. */ |
| 1695 | if (packet->packet_type == DHCPREQUEST3 && !ip_lease && !fixed_lease) |
| 1696 | return NULL((void *)0); |
| 1697 | |
| 1698 | /* At this point, if fixed_lease is nonzero, we can assign it to |
| 1699 | this client. */ |
| 1700 | if (fixed_lease) |
| 1701 | lease = fixed_lease; |
| 1702 | |
| 1703 | /* If we got a lease that matched the ip address and don't have |
| 1704 | a better offer, use that; otherwise, release it. */ |
| 1705 | if (ip_lease) { |
| 1706 | if (lease) { |
| 1707 | if (packet->packet_type == DHCPREQUEST3) |
| 1708 | release_lease(ip_lease); |
| 1709 | } else { |
| 1710 | lease = ip_lease; |
| 1711 | lease->host = NULL((void *)0); |
| 1712 | } |
| 1713 | } |
| 1714 | |
| 1715 | /* If we got a lease that matched the client identifier, we may want |
| 1716 | to use it, but if we already have a lease we like, we must free |
| 1717 | the lease that matched the client identifier. */ |
| 1718 | if (uid_lease) { |
| 1719 | if (lease) { |
| 1720 | if (packet->packet_type == DHCPREQUEST3) |
| 1721 | release_lease(uid_lease); |
| 1722 | } else { |
| 1723 | lease = uid_lease; |
| 1724 | lease->host = NULL((void *)0); |
| 1725 | } |
| 1726 | } |
| 1727 | |
| 1728 | /* The lease that matched the hardware address is treated likewise. */ |
| 1729 | if (hw_lease) { |
| 1730 | if (lease) { |
| 1731 | if (packet->packet_type == DHCPREQUEST3) |
| 1732 | release_lease(hw_lease); |
| 1733 | } else { |
| 1734 | lease = hw_lease; |
| 1735 | lease->host = NULL((void *)0); |
| 1736 | } |
| 1737 | } |
| 1738 | |
| 1739 | /* If we found a host_decl but no matching address, try to |
| 1740 | find a host_decl that has no address, and if there is one, |
| 1741 | hang it off the lease so that we can use the supplied |
| 1742 | options. */ |
| 1743 | if (lease && host && !lease->host) { |
| 1744 | for (; host; host = host->n_ipaddr) { |
| 1745 | if (!host->fixed_addr) { |
| 1746 | lease->host = host; |
| 1747 | break; |
| 1748 | } |
| 1749 | } |
| 1750 | } |
| 1751 | |
| 1752 | /* If we find an abandoned lease, take it, but print a |
| 1753 | warning message, so that if it continues to lose, |
| 1754 | the administrator will eventually investigate. */ |
| 1755 | if (lease && (lease->flags & ABANDONED_LEASE16)) { |
| 1756 | if (packet->packet_type == DHCPREQUEST3) { |
| 1757 | log_warnx("Reclaiming REQUESTed abandoned IP address " |
| 1758 | "%s.", piaddr(lease->ip_addr)); |
| 1759 | lease->flags &= ~ABANDONED_LEASE16; |
| 1760 | } else |
| 1761 | lease = NULL((void *)0); |
| 1762 | } |
| 1763 | return lease; |
| 1764 | } |
| 1765 | |
| 1766 | /* |
| 1767 | * Search the provided host_decl structure list for an address that's on |
| 1768 | * the specified shared network. If one is found, mock up and return a |
| 1769 | * lease structure for it; otherwise return the null pointer. |
| 1770 | */ |
| 1771 | struct lease * |
| 1772 | mockup_lease(struct packet *packet, struct shared_network *share, |
| 1773 | struct host_decl *hp) |
| 1774 | { |
| 1775 | static struct lease mock; |
| 1776 | |
| 1777 | mock.subnet = find_host_for_network(&hp, &mock.ip_addr, share); |
| 1778 | if (!mock.subnet) |
| 1779 | return (NULL((void *)0)); |
| 1780 | mock.next = mock.prev = NULL((void *)0); |
| 1781 | mock.shared_network = mock.subnet->shared_network; |
| 1782 | mock.host = hp; |
| 1783 | |
| 1784 | if (hp->group->options[DHO_DHCP_CLIENT_IDENTIFIER61]) { |
| 1785 | mock.uid = |
| 1786 | hp->group->options[DHO_DHCP_CLIENT_IDENTIFIER61]->value; |
| 1787 | mock.uid_len = |
| 1788 | hp->group->options[DHO_DHCP_CLIENT_IDENTIFIER61]->len; |
| 1789 | } else { |
| 1790 | mock.uid = NULL((void *)0); |
| 1791 | mock.uid_len = 0; |
| 1792 | } |
| 1793 | |
| 1794 | mock.hardware_addr = hp->interface; |
| 1795 | mock.starts = mock.timestamp = mock.ends = MIN_TIME0; |
| 1796 | mock.flags = STATIC_LEASE1; |
| 1797 | return &mock; |
| 1798 | } |