Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1 | /* |
| 2 | * dhcpcd - DHCP client daemon |
| 3 | * Copyright (c) 2006-2015 Roy Marples <roy@marples.name> |
| 4 | * All rights reserved |
| 5 | |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 16 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 17 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 18 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 19 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 20 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 21 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 22 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 23 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 24 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 25 | * SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #include <sys/param.h> |
| 29 | #include <sys/socket.h> |
| 30 | #include <sys/stat.h> |
| 31 | |
| 32 | #include <arpa/inet.h> |
| 33 | #include <net/if.h> |
| 34 | #include <net/route.h> |
| 35 | #include <netinet/if_ether.h> |
| 36 | #include <netinet/in_systm.h> |
| 37 | #include <netinet/in.h> |
| 38 | #include <netinet/ip.h> |
| 39 | #define __FAVOR_BSD /* Nasty glibc hack so we can use BSD semantics for UDP */ |
| 40 | #include <netinet/udp.h> |
| 41 | #undef __FAVOR_BSD |
| 42 | |
| 43 | #include <ctype.h> |
| 44 | #include <errno.h> |
| 45 | #include <fcntl.h> |
| 46 | #include <inttypes.h> |
| 47 | #include <stddef.h> |
| 48 | #include <stdlib.h> |
| 49 | #include <string.h> |
| 50 | #include <unistd.h> |
| 51 | |
| 52 | #define ELOOP_QUEUE 2 |
| 53 | #include "config.h" |
| 54 | #include "arp.h" |
| 55 | #include "common.h" |
| 56 | #include "dhcp.h" |
| 57 | #include "dhcpcd.h" |
| 58 | #include "dhcp-common.h" |
| 59 | #include "duid.h" |
| 60 | #include "eloop.h" |
| 61 | #include "if.h" |
| 62 | #include "ipv4.h" |
| 63 | #include "ipv4ll.h" |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 64 | #include "rpc-interface.h" |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 65 | #include "script.h" |
| 66 | |
| 67 | #define DAD "Duplicate address detected" |
| 68 | #define DHCP_MIN_LEASE 20 |
| 69 | |
| 70 | #define IPV4A ADDRIPV4 | ARRAY |
| 71 | #define IPV4R ADDRIPV4 | REQUEST |
| 72 | |
| 73 | /* We should define a maximum for the NAK exponential backoff */ |
| 74 | #define NAKOFF_MAX 60 |
| 75 | |
| 76 | /* Wait N nanoseconds between sending a RELEASE and dropping the address. |
| 77 | * This gives the kernel enough time to actually send it. */ |
| 78 | #define RELEASE_DELAY_S 0 |
| 79 | #define RELEASE_DELAY_NS 10000000 |
| 80 | |
| 81 | #ifndef IPDEFTTL |
| 82 | #define IPDEFTTL 64 /* RFC1340 */ |
| 83 | #endif |
| 84 | |
| 85 | struct dhcp_op { |
| 86 | uint8_t value; |
| 87 | const char *name; |
| 88 | }; |
| 89 | |
| 90 | static const struct dhcp_op dhcp_ops[] = { |
| 91 | { DHCP_DISCOVER, "DISCOVER" }, |
| 92 | { DHCP_OFFER, "OFFER" }, |
| 93 | { DHCP_REQUEST, "REQUEST" }, |
| 94 | { DHCP_DECLINE, "DECLINE" }, |
| 95 | { DHCP_ACK, "ACK" }, |
| 96 | { DHCP_NAK, "NAK" }, |
| 97 | { DHCP_RELEASE, "RELEASE" }, |
| 98 | { DHCP_INFORM, "INFORM" }, |
| 99 | { DHCP_FORCERENEW, "DHCP_FORCERENEW"}, |
| 100 | { 0, NULL } |
| 101 | }; |
| 102 | |
| 103 | static const char * const dhcp_params[] = { |
| 104 | "ip_address", |
| 105 | "subnet_cidr", |
| 106 | "network_number", |
| 107 | "filename", |
| 108 | "server_name", |
| 109 | NULL |
| 110 | }; |
| 111 | |
| 112 | struct udp_dhcp_packet |
| 113 | { |
| 114 | struct ip ip; |
| 115 | struct udphdr udp; |
| 116 | struct dhcp_message dhcp; |
| 117 | }; |
| 118 | |
| 119 | static const size_t udp_dhcp_len = sizeof(struct udp_dhcp_packet); |
| 120 | |
| 121 | static int dhcp_open(struct interface *ifp); |
| 122 | |
| 123 | void |
| 124 | dhcp_printoptions(const struct dhcpcd_ctx *ctx, |
| 125 | const struct dhcp_opt *opts, size_t opts_len) |
| 126 | { |
| 127 | const char * const *p; |
| 128 | size_t i, j; |
| 129 | const struct dhcp_opt *opt, *opt2; |
| 130 | int cols; |
| 131 | |
| 132 | for (p = dhcp_params; *p; p++) |
| 133 | printf(" %s\n", *p); |
| 134 | |
| 135 | for (i = 0, opt = ctx->dhcp_opts; i < ctx->dhcp_opts_len; i++, opt++) { |
| 136 | for (j = 0, opt2 = opts; j < opts_len; j++, opt2++) |
| 137 | if (opt->option == opt2->option) |
| 138 | break; |
| 139 | if (j == opts_len) { |
| 140 | cols = printf("%03d %s", opt->option, opt->var); |
| 141 | dhcp_print_option_encoding(opt, cols); |
| 142 | } |
| 143 | } |
| 144 | for (i = 0, opt = opts; i < opts_len; i++, opt++) { |
| 145 | cols = printf("%03d %s", opt->option, opt->var); |
| 146 | dhcp_print_option_encoding(opt, cols); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | #define get_option_raw(ctx, dhcp, opt) get_option(ctx, dhcp, opt, NULL) |
| 151 | static const uint8_t * |
| 152 | get_option(struct dhcpcd_ctx *ctx, |
| 153 | const struct dhcp_message *dhcp, unsigned int opt, size_t *len) |
| 154 | { |
| 155 | const uint8_t *p = dhcp->options; |
| 156 | const uint8_t *e = p + sizeof(dhcp->options); |
| 157 | uint8_t l, ol = 0; |
| 158 | uint8_t o = 0; |
| 159 | uint8_t overl = 0; |
| 160 | uint8_t *bp = NULL; |
| 161 | const uint8_t *op = NULL; |
| 162 | size_t bl = 0; |
| 163 | |
| 164 | /* Check we have the magic cookie */ |
| 165 | if (dhcp->cookie != htonl(MAGIC_COOKIE)) { |
| 166 | errno = ENOTSUP; |
| 167 | return NULL; |
| 168 | } |
| 169 | |
Samuel Tan | 9ae79b8 | 2015-08-13 16:46:52 -0700 | [diff] [blame] | 170 | /* DHCP options are in TLV format with T and L each being a single |
| 171 | * bytes. In general, here we have p -> T, ol=p+1 -> L, op -> V. |
| 172 | * We must make sure there is enough room to read both T and L. |
| 173 | */ |
| 174 | while (p + 1 < e) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 175 | o = *p++; |
| 176 | if (o == opt) { |
| 177 | if (op) { |
| 178 | if (!ctx->opt_buffer) { |
| 179 | ctx->opt_buffer = |
| 180 | malloc(DHCP_OPTION_LEN + |
| 181 | BOOTFILE_LEN + SERVERNAME_LEN); |
| 182 | if (ctx->opt_buffer == NULL) |
| 183 | return NULL; |
| 184 | } |
| 185 | if (!bp) |
| 186 | bp = ctx->opt_buffer; |
| 187 | memcpy(bp, op, ol); |
| 188 | bp += ol; |
| 189 | } |
Samuel Tan | 9ae79b8 | 2015-08-13 16:46:52 -0700 | [diff] [blame] | 190 | ol = (p + *p < e) ? *p : e - (p + 1); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 191 | if (p + ol > e) { |
| 192 | errno = EINVAL; |
| 193 | return NULL; |
| 194 | } |
| 195 | op = p + 1; |
| 196 | bl += ol; |
| 197 | } |
| 198 | switch (o) { |
| 199 | case DHO_PAD: |
| 200 | continue; |
| 201 | case DHO_END: |
| 202 | if (overl & 1) { |
| 203 | /* bit 1 set means parse boot file */ |
| 204 | overl = (uint8_t)(overl & ~1); |
| 205 | p = dhcp->bootfile; |
| 206 | e = p + sizeof(dhcp->bootfile); |
| 207 | } else if (overl & 2) { |
| 208 | /* bit 2 set means parse server name */ |
| 209 | overl = (uint8_t)(overl & ~2); |
| 210 | p = dhcp->servername; |
| 211 | e = p + sizeof(dhcp->servername); |
| 212 | } else |
| 213 | goto exit; |
| 214 | break; |
| 215 | case DHO_OPTIONSOVERLOADED: |
| 216 | /* Ensure we only get this option once by setting |
| 217 | * the last bit as well as the value. |
| 218 | * This is valid because only the first two bits |
| 219 | * actually mean anything in RFC2132 Section 9.3 */ |
| 220 | if (!overl) |
| 221 | overl = 0x80 | p[1]; |
| 222 | break; |
| 223 | } |
| 224 | l = *p++; |
| 225 | p += l; |
| 226 | } |
| 227 | |
| 228 | exit: |
| 229 | if (len) |
| 230 | *len = bl; |
| 231 | if (bp) { |
| 232 | memcpy(bp, op, ol); |
| 233 | return (const uint8_t *)ctx->opt_buffer; |
| 234 | } |
| 235 | if (op) |
| 236 | return op; |
| 237 | errno = ENOENT; |
| 238 | return NULL; |
| 239 | } |
| 240 | |
| 241 | int |
| 242 | get_option_addr(struct dhcpcd_ctx *ctx, |
| 243 | struct in_addr *a, const struct dhcp_message *dhcp, |
| 244 | uint8_t option) |
| 245 | { |
| 246 | const uint8_t *p; |
| 247 | size_t len; |
| 248 | |
| 249 | p = get_option(ctx, dhcp, option, &len); |
| 250 | if (!p || len < (ssize_t)sizeof(a->s_addr)) |
| 251 | return -1; |
| 252 | memcpy(&a->s_addr, p, sizeof(a->s_addr)); |
| 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | static int |
| 257 | get_option_uint32(struct dhcpcd_ctx *ctx, |
| 258 | uint32_t *i, const struct dhcp_message *dhcp, uint8_t option) |
| 259 | { |
| 260 | const uint8_t *p; |
| 261 | size_t len; |
| 262 | uint32_t d; |
| 263 | |
| 264 | p = get_option(ctx, dhcp, option, &len); |
| 265 | if (!p || len < (ssize_t)sizeof(d)) |
| 266 | return -1; |
| 267 | memcpy(&d, p, sizeof(d)); |
| 268 | if (i) |
| 269 | *i = ntohl(d); |
| 270 | return 0; |
| 271 | } |
| 272 | |
| 273 | static int |
| 274 | get_option_uint8(struct dhcpcd_ctx *ctx, |
| 275 | uint8_t *i, const struct dhcp_message *dhcp, uint8_t option) |
| 276 | { |
| 277 | const uint8_t *p; |
| 278 | size_t len; |
| 279 | |
| 280 | p = get_option(ctx, dhcp, option, &len); |
| 281 | if (!p || len < (ssize_t)sizeof(*p)) |
| 282 | return -1; |
| 283 | if (i) |
| 284 | *i = *(p); |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | ssize_t |
| 289 | decode_rfc3442(char *out, size_t len, const uint8_t *p, size_t pl) |
| 290 | { |
| 291 | const uint8_t *e; |
| 292 | size_t bytes = 0, ocets; |
| 293 | int b; |
| 294 | uint8_t cidr; |
| 295 | struct in_addr addr; |
| 296 | char *o = out; |
| 297 | |
| 298 | /* Minimum is 5 -first is CIDR and a router length of 4 */ |
| 299 | if (pl < 5) { |
| 300 | errno = EINVAL; |
| 301 | return -1; |
| 302 | } |
| 303 | |
| 304 | e = p + pl; |
| 305 | while (p < e) { |
| 306 | cidr = *p++; |
| 307 | if (cidr > 32) { |
| 308 | errno = EINVAL; |
| 309 | return -1; |
| 310 | } |
| 311 | ocets = (size_t)(cidr + 7) / NBBY; |
| 312 | if (p + 4 + ocets > e) { |
| 313 | errno = ERANGE; |
| 314 | return -1; |
| 315 | } |
| 316 | if (!out) { |
| 317 | p += 4 + ocets; |
| 318 | bytes += ((4 * 4) * 2) + 4; |
| 319 | continue; |
| 320 | } |
| 321 | if ((((4 * 4) * 2) + 4) > len) { |
| 322 | errno = ENOBUFS; |
| 323 | return -1; |
| 324 | } |
| 325 | if (o != out) { |
| 326 | *o++ = ' '; |
| 327 | len--; |
| 328 | } |
| 329 | /* If we have ocets then we have a destination and netmask */ |
| 330 | if (ocets > 0) { |
| 331 | addr.s_addr = 0; |
| 332 | memcpy(&addr.s_addr, p, ocets); |
| 333 | b = snprintf(o, len, "%s/%d", inet_ntoa(addr), cidr); |
| 334 | p += ocets; |
| 335 | } else |
| 336 | b = snprintf(o, len, "0.0.0.0/0"); |
| 337 | o += b; |
| 338 | len -= (size_t)b; |
| 339 | |
| 340 | /* Finally, snag the router */ |
| 341 | memcpy(&addr.s_addr, p, 4); |
| 342 | p += 4; |
| 343 | b = snprintf(o, len, " %s", inet_ntoa(addr)); |
| 344 | o += b; |
| 345 | len -= (size_t)b; |
| 346 | } |
| 347 | |
| 348 | if (out) |
| 349 | return o - out; |
| 350 | return (ssize_t)bytes; |
| 351 | } |
| 352 | |
| 353 | static struct rt_head * |
| 354 | decode_rfc3442_rt(struct dhcpcd_ctx *ctx, const uint8_t *data, size_t dl) |
| 355 | { |
| 356 | const uint8_t *p = data; |
| 357 | const uint8_t *e; |
| 358 | uint8_t cidr; |
| 359 | size_t ocets; |
| 360 | struct rt_head *routes; |
| 361 | struct rt *rt = NULL; |
| 362 | |
| 363 | /* Minimum is 5 -first is CIDR and a router length of 4 */ |
| 364 | if (dl < 5) |
| 365 | return NULL; |
| 366 | |
| 367 | routes = malloc(sizeof(*routes)); |
| 368 | TAILQ_INIT(routes); |
| 369 | e = p + dl; |
| 370 | while (p < e) { |
| 371 | cidr = *p++; |
| 372 | if (cidr > 32) { |
| 373 | ipv4_freeroutes(routes); |
| 374 | errno = EINVAL; |
| 375 | return NULL; |
| 376 | } |
| 377 | |
| 378 | ocets = (size_t)(cidr + 7) / NBBY; |
| 379 | if (p + 4 + ocets > e) { |
| 380 | ipv4_freeroutes(routes); |
| 381 | errno = ERANGE; |
| 382 | return NULL; |
| 383 | } |
| 384 | |
| 385 | rt = calloc(1, sizeof(*rt)); |
| 386 | if (rt == NULL) { |
| 387 | logger(ctx, LOG_ERR, "%s: %m", __func__); |
| 388 | ipv4_freeroutes(routes); |
| 389 | return NULL; |
| 390 | } |
| 391 | TAILQ_INSERT_TAIL(routes, rt, next); |
| 392 | |
| 393 | /* If we have ocets then we have a destination and netmask */ |
| 394 | if (ocets > 0) { |
| 395 | memcpy(&rt->dest.s_addr, p, ocets); |
| 396 | p += ocets; |
| 397 | rt->net.s_addr = htonl(~0U << (32 - cidr)); |
| 398 | } |
| 399 | |
| 400 | /* Finally, snag the router */ |
| 401 | memcpy(&rt->gate.s_addr, p, 4); |
| 402 | p += 4; |
| 403 | } |
| 404 | return routes; |
| 405 | } |
| 406 | |
| 407 | char * |
| 408 | decode_rfc3361(const uint8_t *data, size_t dl) |
| 409 | { |
| 410 | uint8_t enc; |
| 411 | size_t l; |
| 412 | ssize_t r; |
| 413 | char *sip = NULL; |
| 414 | struct in_addr addr; |
| 415 | char *p; |
| 416 | |
| 417 | if (dl < 2) { |
| 418 | errno = EINVAL; |
| 419 | return 0; |
| 420 | } |
| 421 | |
| 422 | enc = *data++; |
| 423 | dl--; |
| 424 | switch (enc) { |
| 425 | case 0: |
| 426 | if ((r = decode_rfc3397(NULL, 0, data, dl)) > 0) { |
| 427 | l = (size_t)r; |
| 428 | sip = malloc(l); |
| 429 | if (sip == NULL) |
| 430 | return 0; |
| 431 | decode_rfc3397(sip, l, data, dl); |
| 432 | } |
| 433 | break; |
| 434 | case 1: |
| 435 | if (dl == 0 || dl % 4 != 0) { |
| 436 | errno = EINVAL; |
| 437 | break; |
| 438 | } |
| 439 | addr.s_addr = INADDR_BROADCAST; |
| 440 | l = ((dl / sizeof(addr.s_addr)) * ((4 * 4) + 1)) + 1; |
| 441 | sip = p = malloc(l); |
| 442 | if (sip == NULL) |
| 443 | return 0; |
| 444 | while (dl != 0) { |
| 445 | memcpy(&addr.s_addr, data, sizeof(addr.s_addr)); |
| 446 | data += sizeof(addr.s_addr); |
| 447 | p += snprintf(p, l - (size_t)(p - sip), |
| 448 | "%s ", inet_ntoa(addr)); |
| 449 | dl -= sizeof(addr.s_addr); |
| 450 | } |
| 451 | *--p = '\0'; |
| 452 | break; |
| 453 | default: |
| 454 | errno = EINVAL; |
| 455 | return 0; |
| 456 | } |
| 457 | |
| 458 | return sip; |
| 459 | } |
| 460 | |
| 461 | /* Decode an RFC5969 6rd order option into a space |
| 462 | * separated string. Returns length of string (including |
| 463 | * terminating zero) or zero on error. */ |
| 464 | ssize_t |
| 465 | decode_rfc5969(char *out, size_t len, const uint8_t *p, size_t pl) |
| 466 | { |
| 467 | uint8_t ipv4masklen, ipv6prefixlen; |
| 468 | uint8_t ipv6prefix[16]; |
| 469 | uint8_t br[4]; |
| 470 | int i; |
| 471 | ssize_t b, bytes = 0; |
| 472 | |
| 473 | if (pl < 22) { |
| 474 | errno = EINVAL; |
| 475 | return 0; |
| 476 | } |
| 477 | |
| 478 | ipv4masklen = *p++; |
| 479 | pl--; |
| 480 | ipv6prefixlen = *p++; |
| 481 | pl--; |
| 482 | |
| 483 | for (i = 0; i < 16; i++) { |
| 484 | ipv6prefix[i] = *p++; |
| 485 | pl--; |
| 486 | } |
| 487 | if (out) { |
| 488 | b= snprintf(out, len, |
| 489 | "%d %d " |
| 490 | "%02x%02x:%02x%02x:" |
| 491 | "%02x%02x:%02x%02x:" |
| 492 | "%02x%02x:%02x%02x:" |
| 493 | "%02x%02x:%02x%02x", |
| 494 | ipv4masklen, ipv6prefixlen, |
| 495 | ipv6prefix[0], ipv6prefix[1], ipv6prefix[2], ipv6prefix[3], |
| 496 | ipv6prefix[4], ipv6prefix[5], ipv6prefix[6], ipv6prefix[7], |
| 497 | ipv6prefix[8], ipv6prefix[9], ipv6prefix[10],ipv6prefix[11], |
| 498 | ipv6prefix[12],ipv6prefix[13],ipv6prefix[14], ipv6prefix[15] |
| 499 | ); |
| 500 | |
| 501 | len -= (size_t)b; |
| 502 | out += b; |
| 503 | bytes += b; |
| 504 | } else { |
| 505 | bytes += 16 * 2 + 8 + 2 + 1 + 2; |
| 506 | } |
| 507 | |
| 508 | while (pl >= 4) { |
| 509 | br[0] = *p++; |
| 510 | br[1] = *p++; |
| 511 | br[2] = *p++; |
| 512 | br[3] = *p++; |
| 513 | pl -= 4; |
| 514 | |
| 515 | if (out) { |
| 516 | b= snprintf(out, len, " %d.%d.%d.%d", |
| 517 | br[0], br[1], br[2], br[3]); |
| 518 | len -= (size_t)b; |
| 519 | out += b; |
| 520 | bytes += b; |
| 521 | } else { |
| 522 | bytes += (4 * 4); |
| 523 | } |
| 524 | } |
| 525 | |
| 526 | return bytes; |
| 527 | } |
| 528 | |
| 529 | static char * |
| 530 | get_option_string(struct dhcpcd_ctx *ctx, |
| 531 | const struct dhcp_message *dhcp, uint8_t option) |
| 532 | { |
| 533 | size_t len; |
| 534 | const uint8_t *p; |
| 535 | char *s; |
| 536 | |
| 537 | p = get_option(ctx, dhcp, option, &len); |
| 538 | if (!p || len == 0 || *p == '\0') |
| 539 | return NULL; |
| 540 | |
| 541 | s = malloc(sizeof(char) * (len + 1)); |
| 542 | if (s) { |
| 543 | memcpy(s, p, len); |
| 544 | s[len] = '\0'; |
| 545 | } |
| 546 | return s; |
| 547 | } |
| 548 | |
| 549 | /* This calculates the netmask that we should use for static routes. |
| 550 | * This IS different from the calculation used to calculate the netmask |
| 551 | * for an interface address. */ |
| 552 | static uint32_t |
| 553 | route_netmask(uint32_t ip_in) |
| 554 | { |
| 555 | /* used to be unsigned long - check if error */ |
| 556 | uint32_t p = ntohl(ip_in); |
| 557 | uint32_t t; |
| 558 | |
| 559 | if (IN_CLASSA(p)) |
| 560 | t = ~IN_CLASSA_NET; |
| 561 | else { |
| 562 | if (IN_CLASSB(p)) |
| 563 | t = ~IN_CLASSB_NET; |
| 564 | else { |
| 565 | if (IN_CLASSC(p)) |
| 566 | t = ~IN_CLASSC_NET; |
| 567 | else |
| 568 | t = 0; |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | while (t & p) |
| 573 | t >>= 1; |
| 574 | |
| 575 | return (htonl(~t)); |
| 576 | } |
| 577 | |
| 578 | /* We need to obey routing options. |
| 579 | * If we have a CSR then we only use that. |
| 580 | * Otherwise we add static routes and then routers. */ |
| 581 | struct rt_head * |
| 582 | get_option_routes(struct interface *ifp, const struct dhcp_message *dhcp) |
| 583 | { |
| 584 | struct if_options *ifo = ifp->options; |
| 585 | const uint8_t *p; |
| 586 | const uint8_t *e; |
| 587 | struct rt_head *routes = NULL; |
| 588 | struct rt *route = NULL; |
| 589 | size_t len; |
| 590 | const char *csr = ""; |
| 591 | |
| 592 | /* If we have CSR's then we MUST use these only */ |
| 593 | if (!has_option_mask(ifo->nomask, DHO_CSR)) |
| 594 | p = get_option(ifp->ctx, dhcp, DHO_CSR, &len); |
| 595 | else |
| 596 | p = NULL; |
| 597 | /* Check for crappy MS option */ |
| 598 | if (!p && !has_option_mask(ifo->nomask, DHO_MSCSR)) { |
| 599 | p = get_option(ifp->ctx, dhcp, DHO_MSCSR, &len); |
| 600 | if (p) |
| 601 | csr = "MS "; |
| 602 | } |
| 603 | if (p) { |
| 604 | routes = decode_rfc3442_rt(ifp->ctx, p, len); |
| 605 | if (routes) { |
| 606 | const struct dhcp_state *state; |
| 607 | |
| 608 | state = D_CSTATE(ifp); |
| 609 | if (!(ifo->options & DHCPCD_CSR_WARNED) && |
| 610 | !(state->added & STATE_FAKE)) |
| 611 | { |
| 612 | logger(ifp->ctx, LOG_DEBUG, |
| 613 | "%s: using %sClassless Static Routes", |
| 614 | ifp->name, csr); |
| 615 | ifo->options |= DHCPCD_CSR_WARNED; |
| 616 | } |
| 617 | return routes; |
| 618 | } |
| 619 | } |
| 620 | |
| 621 | /* OK, get our static routes first. */ |
| 622 | routes = malloc(sizeof(*routes)); |
| 623 | if (routes == NULL) { |
| 624 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 625 | return NULL; |
| 626 | } |
| 627 | TAILQ_INIT(routes); |
| 628 | if (!has_option_mask(ifo->nomask, DHO_STATICROUTE)) |
| 629 | p = get_option(ifp->ctx, dhcp, DHO_STATICROUTE, &len); |
| 630 | else |
| 631 | p = NULL; |
| 632 | /* RFC 2131 Section 5.8 states length MUST be in multiples of 8 */ |
| 633 | if (p && len % 8 == 0) { |
| 634 | e = p + len; |
| 635 | while (p < e) { |
| 636 | if ((route = calloc(1, sizeof(*route))) == NULL) { |
| 637 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 638 | ipv4_freeroutes(routes); |
| 639 | return NULL; |
| 640 | } |
| 641 | memcpy(&route->dest.s_addr, p, 4); |
| 642 | p += 4; |
| 643 | memcpy(&route->gate.s_addr, p, 4); |
| 644 | p += 4; |
| 645 | /* RFC 2131 Section 5.8 states default route is |
| 646 | * illegal */ |
| 647 | if (route->dest.s_addr == htonl(INADDR_ANY)) { |
| 648 | errno = EINVAL; |
| 649 | free(route); |
| 650 | continue; |
| 651 | } |
| 652 | route->net.s_addr = route_netmask(route->dest.s_addr); |
| 653 | TAILQ_INSERT_TAIL(routes, route, next); |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | /* Now grab our routers */ |
| 658 | if (!has_option_mask(ifo->nomask, DHO_ROUTER)) |
| 659 | p = get_option(ifp->ctx, dhcp, DHO_ROUTER, &len); |
| 660 | else |
| 661 | p = NULL; |
| 662 | if (p) { |
| 663 | e = p + len; |
| 664 | while (p < e) { |
| 665 | if ((route = calloc(1, sizeof(*route))) == NULL) { |
| 666 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 667 | ipv4_freeroutes(routes); |
| 668 | return NULL; |
| 669 | } |
| 670 | memcpy(&route->gate.s_addr, p, 4); |
| 671 | p += 4; |
| 672 | TAILQ_INSERT_TAIL(routes, route, next); |
| 673 | } |
| 674 | } |
| 675 | |
| 676 | return routes; |
| 677 | } |
| 678 | |
| 679 | #define PUTADDR(_type, _val) \ |
| 680 | { \ |
| 681 | *p++ = _type; \ |
| 682 | *p++ = 4; \ |
| 683 | memcpy(p, &_val.s_addr, 4); \ |
| 684 | p += 4; \ |
| 685 | } |
| 686 | |
| 687 | int |
| 688 | dhcp_message_add_addr(struct dhcp_message *dhcp, |
| 689 | uint8_t type, struct in_addr addr) |
| 690 | { |
| 691 | uint8_t *p; |
| 692 | size_t len; |
| 693 | |
| 694 | p = dhcp->options; |
| 695 | while (*p != DHO_END) { |
| 696 | p++; |
| 697 | p += *p + 1; |
| 698 | } |
| 699 | |
| 700 | len = (size_t)(p - (uint8_t *)dhcp); |
| 701 | if (len + 6 > sizeof(*dhcp)) { |
| 702 | errno = ENOMEM; |
| 703 | return -1; |
| 704 | } |
| 705 | |
| 706 | PUTADDR(type, addr); |
| 707 | *p = DHO_END; |
| 708 | return 0; |
| 709 | } |
| 710 | |
| 711 | ssize_t |
| 712 | make_message(struct dhcp_message **message, |
| 713 | const struct interface *ifp, |
| 714 | uint8_t type) |
| 715 | { |
| 716 | struct dhcp_message *dhcp; |
| 717 | uint8_t *m, *lp, *p, *auth; |
| 718 | uint8_t *n_params = NULL, auth_len; |
| 719 | uint32_t ul; |
| 720 | uint16_t sz; |
| 721 | size_t len, i; |
| 722 | const struct dhcp_opt *opt; |
| 723 | struct if_options *ifo = ifp->options; |
| 724 | const struct dhcp_state *state = D_CSTATE(ifp); |
| 725 | const struct dhcp_lease *lease = &state->lease; |
| 726 | time_t up = uptime() - state->start_uptime; |
| 727 | char hbuf[HOSTNAME_MAX_LEN + 1]; |
| 728 | const char *hostname; |
| 729 | const struct vivco *vivco; |
| 730 | |
| 731 | dhcp = calloc(1, sizeof (*dhcp)); |
| 732 | if (dhcp == NULL) |
| 733 | return -1; |
| 734 | m = (uint8_t *)dhcp; |
| 735 | p = dhcp->options; |
| 736 | |
| 737 | if ((type == DHCP_INFORM || type == DHCP_RELEASE || |
| 738 | (type == DHCP_REQUEST && |
| 739 | state->net.s_addr == lease->net.s_addr && |
| 740 | (state->new == NULL || |
| 741 | state->new->cookie == htonl(MAGIC_COOKIE))))) |
| 742 | { |
| 743 | dhcp->ciaddr = state->addr.s_addr; |
| 744 | /* In-case we haven't actually configured the address yet */ |
| 745 | if (type == DHCP_INFORM && state->addr.s_addr == 0) |
| 746 | dhcp->ciaddr = lease->addr.s_addr; |
| 747 | } |
| 748 | |
| 749 | dhcp->op = DHCP_BOOTREQUEST; |
| 750 | dhcp->hwtype = (uint8_t)ifp->family; |
| 751 | switch (ifp->family) { |
| 752 | case ARPHRD_ETHER: |
| 753 | case ARPHRD_IEEE802: |
| 754 | dhcp->hwlen = (uint8_t)ifp->hwlen; |
| 755 | memcpy(&dhcp->chaddr, &ifp->hwaddr, ifp->hwlen); |
| 756 | break; |
| 757 | } |
| 758 | |
| 759 | if (ifo->options & DHCPCD_BROADCAST && |
| 760 | dhcp->ciaddr == 0 && |
| 761 | type != DHCP_DECLINE && |
| 762 | type != DHCP_RELEASE) |
| 763 | dhcp->flags = htons(BROADCAST_FLAG); |
| 764 | |
| 765 | if (type != DHCP_DECLINE && type != DHCP_RELEASE) { |
| 766 | if (up < 0 || up > (time_t)UINT16_MAX) |
| 767 | dhcp->secs = htons((uint16_t)UINT16_MAX); |
| 768 | else |
| 769 | dhcp->secs = htons((uint16_t)up); |
| 770 | } |
| 771 | dhcp->xid = htonl(state->xid); |
| 772 | dhcp->cookie = htonl(MAGIC_COOKIE); |
| 773 | |
| 774 | if (!(ifo->options & DHCPCD_BOOTP)) { |
| 775 | *p++ = DHO_MESSAGETYPE; |
| 776 | *p++ = 1; |
| 777 | *p++ = type; |
| 778 | } |
| 779 | |
| 780 | if (state->clientid) { |
| 781 | *p++ = DHO_CLIENTID; |
| 782 | memcpy(p, state->clientid, (size_t)state->clientid[0] + 1); |
| 783 | p += state->clientid[0] + 1; |
| 784 | } |
| 785 | |
| 786 | if (lease->addr.s_addr && lease->cookie == htonl(MAGIC_COOKIE)) { |
| 787 | if (type == DHCP_DECLINE || |
| 788 | (type == DHCP_REQUEST && |
| 789 | lease->addr.s_addr != state->addr.s_addr)) |
| 790 | { |
| 791 | PUTADDR(DHO_IPADDRESS, lease->addr); |
| 792 | if (lease->server.s_addr) |
| 793 | PUTADDR(DHO_SERVERID, lease->server); |
| 794 | } |
| 795 | |
| 796 | if (type == DHCP_RELEASE) { |
| 797 | if (lease->server.s_addr) |
| 798 | PUTADDR(DHO_SERVERID, lease->server); |
| 799 | } |
| 800 | } |
| 801 | |
| 802 | if (type == DHCP_DECLINE) { |
| 803 | *p++ = DHO_MESSAGE; |
| 804 | len = strlen(DAD); |
| 805 | *p++ = (uint8_t)len; |
| 806 | memcpy(p, DAD, len); |
| 807 | p += len; |
| 808 | } |
| 809 | |
| 810 | if (type == DHCP_DISCOVER && |
| 811 | !(ifp->ctx->options & DHCPCD_TEST) && |
| 812 | has_option_mask(ifo->requestmask, DHO_RAPIDCOMMIT)) |
| 813 | { |
| 814 | /* RFC 4039 Section 3 */ |
| 815 | *p++ = DHO_RAPIDCOMMIT; |
| 816 | *p++ = 0; |
| 817 | } |
| 818 | |
| 819 | if (type == DHCP_DISCOVER && ifo->options & DHCPCD_REQUEST) |
| 820 | PUTADDR(DHO_IPADDRESS, ifo->req_addr); |
| 821 | |
| 822 | /* RFC 2563 Auto Configure */ |
| 823 | if (type == DHCP_DISCOVER && ifo->options & DHCPCD_IPV4LL) { |
| 824 | *p++ = DHO_AUTOCONFIGURE; |
| 825 | *p++ = 1; |
| 826 | *p++ = 1; |
| 827 | } |
| 828 | |
| 829 | if (type == DHCP_DISCOVER || |
| 830 | type == DHCP_INFORM || |
| 831 | type == DHCP_REQUEST) |
| 832 | { |
| 833 | if (!(ifo->options & DHCPCD_BOOTP)) { |
| 834 | int mtu; |
| 835 | |
| 836 | *p++ = DHO_MAXMESSAGESIZE; |
| 837 | *p++ = 2; |
| 838 | mtu = if_getmtu(ifp->name); |
| 839 | if (mtu < MTU_MIN) { |
| 840 | if (if_setmtu(ifp->name, MTU_MIN) == 0) |
| 841 | sz = MTU_MIN; |
| 842 | } else if (mtu > MTU_MAX) { |
| 843 | /* Even though our MTU could be greater than |
| 844 | * MTU_MAX (1500) dhcpcd does not presently |
| 845 | * handle DHCP packets any bigger. */ |
| 846 | mtu = MTU_MAX; |
| 847 | } |
| 848 | sz = htons((uint16_t)mtu); |
| 849 | memcpy(p, &sz, 2); |
| 850 | p += 2; |
| 851 | } |
| 852 | |
| 853 | if (ifo->userclass[0]) { |
| 854 | *p++ = DHO_USERCLASS; |
| 855 | memcpy(p, ifo->userclass, |
| 856 | (size_t)ifo->userclass[0] + 1); |
| 857 | p += ifo->userclass[0] + 1; |
| 858 | } |
| 859 | |
| 860 | if (ifo->vendorclassid[0]) { |
| 861 | *p++ = DHO_VENDORCLASSID; |
| 862 | memcpy(p, ifo->vendorclassid, |
| 863 | (size_t)ifo->vendorclassid[0] + 1); |
| 864 | p += ifo->vendorclassid[0] + 1; |
| 865 | } |
| 866 | |
| 867 | if (type != DHCP_INFORM) { |
| 868 | if (ifo->leasetime != 0) { |
| 869 | *p++ = DHO_LEASETIME; |
| 870 | *p++ = 4; |
| 871 | ul = htonl(ifo->leasetime); |
| 872 | memcpy(p, &ul, 4); |
| 873 | p += 4; |
| 874 | } |
| 875 | } |
| 876 | |
| 877 | if (ifo->hostname[0] == '\0') |
| 878 | hostname = get_hostname(hbuf, sizeof(hbuf), |
| 879 | ifo->options & DHCPCD_HOSTNAME_SHORT ? 1 : 0); |
| 880 | else |
| 881 | hostname = ifo->hostname; |
| 882 | |
| 883 | /* |
| 884 | * RFC4702 3.1 States that if we send the Client FQDN option |
| 885 | * then we MUST NOT also send the Host Name option. |
| 886 | * Technically we could, but that is not RFC conformant and |
| 887 | * also seems to break some DHCP server implemetations such as |
| 888 | * Windows. On the other hand, ISC dhcpd is just as non RFC |
| 889 | * conformant by not accepting a partially qualified FQDN. |
| 890 | */ |
| 891 | if (ifo->fqdn != FQDN_DISABLE) { |
| 892 | /* IETF DHC-FQDN option (81), RFC4702 */ |
| 893 | *p++ = DHO_FQDN; |
| 894 | lp = p; |
| 895 | *p++ = 3; |
| 896 | /* |
| 897 | * Flags: 0000NEOS |
| 898 | * S: 1 => Client requests Server to update |
| 899 | * a RR in DNS as well as PTR |
| 900 | * O: 1 => Server indicates to client that |
| 901 | * DNS has been updated |
| 902 | * E: 1 => Name data is DNS format |
| 903 | * N: 1 => Client requests Server to not |
| 904 | * update DNS |
| 905 | */ |
| 906 | if (hostname) |
| 907 | *p++ = (uint8_t)((ifo->fqdn & 0x09) | 0x04); |
| 908 | else |
| 909 | *p++ = (FQDN_NONE & 0x09) | 0x04; |
| 910 | *p++ = 0; /* from server for PTR RR */ |
| 911 | *p++ = 0; /* from server for A RR if S=1 */ |
| 912 | if (hostname) { |
| 913 | i = encode_rfc1035(hostname, p); |
| 914 | *lp = (uint8_t)(*lp + i); |
| 915 | p += i; |
| 916 | } |
| 917 | } else if (ifo->options & DHCPCD_HOSTNAME && hostname) { |
| 918 | *p++ = DHO_HOSTNAME; |
| 919 | len = strlen(hostname); |
| 920 | *p++ = (uint8_t)len; |
| 921 | memcpy(p, hostname, len); |
| 922 | p += len; |
| 923 | } |
| 924 | |
| 925 | /* vendor is already encoded correctly, so just add it */ |
| 926 | if (ifo->vendor[0]) { |
| 927 | *p++ = DHO_VENDOR; |
| 928 | memcpy(p, ifo->vendor, (size_t)ifo->vendor[0] + 1); |
| 929 | p += ifo->vendor[0] + 1; |
| 930 | } |
| 931 | |
| 932 | if ((ifo->auth.options & DHCPCD_AUTH_SENDREQUIRE) != |
| 933 | DHCPCD_AUTH_SENDREQUIRE) |
| 934 | { |
| 935 | /* We support HMAC-MD5 */ |
| 936 | *p++ = DHO_FORCERENEW_NONCE; |
| 937 | *p++ = 1; |
| 938 | *p++ = AUTH_ALG_HMAC_MD5; |
| 939 | } |
| 940 | |
| 941 | if (ifo->vivco_len) { |
| 942 | *p++ = DHO_VIVCO; |
| 943 | lp = p++; |
| 944 | *lp = sizeof(ul); |
| 945 | ul = htonl(ifo->vivco_en); |
| 946 | memcpy(p, &ul, sizeof(ul)); |
| 947 | p += sizeof(ul); |
| 948 | for (i = 0, vivco = ifo->vivco; |
| 949 | i < ifo->vivco_len; |
| 950 | i++, vivco++) |
| 951 | { |
| 952 | len = (size_t)(p - m) + vivco->len + 1; |
| 953 | if (len > sizeof(*dhcp)) |
| 954 | goto toobig; |
| 955 | if (vivco->len + 2 + *lp > 255) { |
| 956 | logger(ifp->ctx, LOG_ERR, |
| 957 | "%s: VIVCO option too big", |
| 958 | ifp->name); |
| 959 | free(dhcp); |
| 960 | return -1; |
| 961 | } |
| 962 | *p++ = (uint8_t)vivco->len; |
| 963 | memcpy(p, vivco->data, vivco->len); |
| 964 | p += vivco->len; |
| 965 | *lp = (uint8_t)(*lp + vivco->len + 1); |
| 966 | } |
| 967 | } |
| 968 | |
| 969 | len = (size_t)((p - m) + 3); |
| 970 | if (len > sizeof(*dhcp)) |
| 971 | goto toobig; |
| 972 | *p++ = DHO_PARAMETERREQUESTLIST; |
| 973 | n_params = p; |
| 974 | *p++ = 0; |
| 975 | for (i = 0, opt = ifp->ctx->dhcp_opts; |
| 976 | i < ifp->ctx->dhcp_opts_len; |
| 977 | i++, opt++) |
| 978 | { |
| 979 | if (!(opt->type & REQUEST || |
| 980 | has_option_mask(ifo->requestmask, opt->option))) |
| 981 | continue; |
| 982 | if (opt->type & NOREQ) |
| 983 | continue; |
| 984 | if (type == DHCP_INFORM && |
| 985 | (opt->option == DHO_RENEWALTIME || |
| 986 | opt->option == DHO_REBINDTIME)) |
| 987 | continue; |
| 988 | len = (size_t)((p - m) + 2); |
| 989 | if (len > sizeof(*dhcp)) |
| 990 | goto toobig; |
| 991 | *p++ = (uint8_t)opt->option; |
| 992 | } |
| 993 | for (i = 0, opt = ifo->dhcp_override; |
| 994 | i < ifo->dhcp_override_len; |
| 995 | i++, opt++) |
| 996 | { |
| 997 | /* Check if added above */ |
| 998 | for (lp = n_params + 1; lp < p; lp++) |
| 999 | if (*lp == (uint8_t)opt->option) |
| 1000 | break; |
| 1001 | if (lp < p) |
| 1002 | continue; |
| 1003 | if (!(opt->type & REQUEST || |
| 1004 | has_option_mask(ifo->requestmask, opt->option))) |
| 1005 | continue; |
| 1006 | if (opt->type & NOREQ) |
| 1007 | continue; |
| 1008 | if (type == DHCP_INFORM && |
| 1009 | (opt->option == DHO_RENEWALTIME || |
| 1010 | opt->option == DHO_REBINDTIME)) |
| 1011 | continue; |
| 1012 | len = (size_t)((p - m) + 2); |
| 1013 | if (len > sizeof(*dhcp)) |
| 1014 | goto toobig; |
| 1015 | *p++ = (uint8_t)opt->option; |
| 1016 | } |
| 1017 | *n_params = (uint8_t)(p - n_params - 1); |
| 1018 | } |
| 1019 | |
| 1020 | /* silence GCC */ |
| 1021 | auth_len = 0; |
| 1022 | auth = NULL; |
| 1023 | |
| 1024 | if (ifo->auth.options & DHCPCD_AUTH_SEND) { |
| 1025 | ssize_t alen = dhcp_auth_encode(&ifo->auth, |
| 1026 | state->auth.token, |
| 1027 | NULL, 0, 4, type, NULL, 0); |
| 1028 | if (alen != -1 && alen > UINT8_MAX) { |
| 1029 | errno = ERANGE; |
| 1030 | alen = -1; |
| 1031 | } |
| 1032 | if (alen == -1) |
| 1033 | logger(ifp->ctx, LOG_ERR, |
| 1034 | "%s: dhcp_auth_encode: %m", ifp->name); |
| 1035 | else if (alen != 0) { |
| 1036 | auth_len = (uint8_t)alen; |
| 1037 | len = (size_t)((p + alen) - m); |
| 1038 | if (len > sizeof(*dhcp)) |
| 1039 | goto toobig; |
| 1040 | *p++ = DHO_AUTHENTICATION; |
| 1041 | *p++ = auth_len; |
| 1042 | auth = p; |
| 1043 | p += auth_len; |
| 1044 | } |
| 1045 | } |
| 1046 | |
| 1047 | *p++ = DHO_END; |
| 1048 | |
| 1049 | /* Pad out to the BOOTP minimum message length. |
| 1050 | * Some DHCP servers incorrectly require this. */ |
| 1051 | while (p - m < BOOTP_MESSAGE_LENTH_MIN) |
| 1052 | *p++ = DHO_PAD; |
| 1053 | |
| 1054 | len = (size_t)(p - m); |
| 1055 | if (ifo->auth.options & DHCPCD_AUTH_SEND && auth_len != 0) |
| 1056 | dhcp_auth_encode(&ifo->auth, state->auth.token, |
| 1057 | m, len, 4, type, auth, auth_len); |
| 1058 | |
| 1059 | *message = dhcp; |
| 1060 | return (ssize_t)len; |
| 1061 | |
| 1062 | toobig: |
| 1063 | logger(ifp->ctx, LOG_ERR, "%s: DHCP messge too big", ifp->name); |
| 1064 | free(dhcp); |
| 1065 | return -1; |
| 1066 | } |
| 1067 | |
| 1068 | static ssize_t |
| 1069 | write_lease(const struct interface *ifp, const struct dhcp_message *dhcp) |
| 1070 | { |
| 1071 | int fd; |
| 1072 | size_t len; |
| 1073 | ssize_t bytes; |
| 1074 | const uint8_t *e, *p; |
| 1075 | uint8_t l; |
| 1076 | uint8_t o = 0; |
| 1077 | const struct dhcp_state *state = D_CSTATE(ifp); |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1078 | uint8_t write_buffer[sizeof(*dhcp) + sizeof(state->server_info) + 1]; |
| 1079 | uint8_t *w; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1080 | |
| 1081 | /* We don't write BOOTP leases */ |
| 1082 | if (IS_BOOTP(ifp, dhcp)) { |
| 1083 | unlink(state->leasefile); |
| 1084 | return 0; |
| 1085 | } |
| 1086 | |
| 1087 | logger(ifp->ctx, LOG_DEBUG, "%s: writing lease `%s'", |
| 1088 | ifp->name, state->leasefile); |
| 1089 | |
Samuel Tan | dd90b01 | 2015-08-13 16:27:29 -0700 | [diff] [blame] | 1090 | fd = open(state->leasefile, O_WRONLY | O_CREAT | O_TRUNC, 0600); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1091 | if (fd == -1) |
| 1092 | return -1; |
| 1093 | |
| 1094 | /* Only write as much as we need */ |
| 1095 | p = dhcp->options; |
| 1096 | e = p + sizeof(dhcp->options); |
| 1097 | len = sizeof(*dhcp); |
| 1098 | while (p < e) { |
| 1099 | o = *p; |
| 1100 | if (o == DHO_END) { |
| 1101 | len = (size_t)(p - (const uint8_t *)dhcp); |
| 1102 | break; |
| 1103 | } |
| 1104 | p++; |
| 1105 | if (o != DHO_PAD) { |
| 1106 | l = *p++; |
| 1107 | p += l; |
| 1108 | } |
| 1109 | } |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1110 | |
| 1111 | memcpy(write_buffer, dhcp, len); |
| 1112 | w = write_buffer + len; |
| 1113 | |
| 1114 | /* Copy in server info if this is available. */ |
| 1115 | if (state->server_info.gw_hwlen != 0) { |
| 1116 | *w++ = DHO_END; |
| 1117 | memcpy(w, &state->server_info, sizeof(state->server_info)); |
| 1118 | len += sizeof(state->server_info) + 1; |
| 1119 | } |
| 1120 | |
| 1121 | bytes = write(fd, write_buffer, len); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1122 | close(fd); |
| 1123 | return bytes; |
| 1124 | } |
| 1125 | |
| 1126 | static struct dhcp_message * |
| 1127 | read_lease(struct interface *ifp) |
| 1128 | { |
| 1129 | int fd; |
| 1130 | struct dhcp_message *dhcp; |
| 1131 | struct dhcp_state *state = D_STATE(ifp); |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1132 | uint8_t read_buffer[sizeof(*dhcp) + sizeof(state->server_info) + 1]; |
| 1133 | const uint8_t *options_startp = |
| 1134 | read_buffer + offsetof(struct dhcp_message, options); |
| 1135 | const uint8_t *options_endp = options_startp + sizeof(dhcp->options); |
| 1136 | uint8_t option_len; |
| 1137 | uint8_t option_type = 0; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1138 | ssize_t bytes; |
| 1139 | const uint8_t *auth; |
| 1140 | uint8_t type; |
| 1141 | size_t auth_len; |
| 1142 | |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1143 | memset(&state->server_info, 0, sizeof(state->server_info)); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1144 | fd = open(state->leasefile, O_RDONLY); |
| 1145 | if (fd == -1) { |
| 1146 | if (errno != ENOENT) |
| 1147 | logger(ifp->ctx, LOG_ERR, "%s: open `%s': %m", |
| 1148 | ifp->name, state->leasefile); |
| 1149 | return NULL; |
| 1150 | } |
| 1151 | logger(ifp->ctx, LOG_DEBUG, "%s: reading lease `%s'", |
| 1152 | ifp->name, state->leasefile); |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1153 | bytes = read(fd, read_buffer, sizeof(read_buffer)); |
| 1154 | close(fd); |
| 1155 | |
| 1156 | /* Lease file should at minimum contain all fields before options. */ |
| 1157 | if (read_buffer + bytes < options_startp) |
| 1158 | return NULL; |
| 1159 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1160 | dhcp = calloc(1, sizeof(*dhcp)); |
| 1161 | if (dhcp == NULL) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1162 | return NULL; |
| 1163 | } |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1164 | |
| 1165 | if (options_endp > read_buffer + bytes) |
| 1166 | options_endp = read_buffer + bytes; |
| 1167 | |
| 1168 | while (options_startp < options_endp) { |
| 1169 | option_type = *options_startp++; |
| 1170 | if (option_type == DHO_END) |
| 1171 | break; |
| 1172 | if (option_type != DHO_PAD) { |
| 1173 | option_len = *options_startp++; |
| 1174 | options_startp += option_len; |
| 1175 | } |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1176 | } |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1177 | memcpy(dhcp, read_buffer, options_startp - read_buffer); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1178 | |
| 1179 | /* We may have found a BOOTP server */ |
| 1180 | if (get_option_uint8(ifp->ctx, &type, dhcp, DHO_MESSAGETYPE) == -1) |
| 1181 | type = 0; |
| 1182 | |
| 1183 | /* Authenticate the message */ |
| 1184 | auth = get_option(ifp->ctx, dhcp, DHO_AUTHENTICATION, &auth_len); |
| 1185 | if (auth) { |
| 1186 | if (dhcp_auth_validate(&state->auth, &ifp->options->auth, |
| 1187 | (uint8_t *)dhcp, sizeof(*dhcp), 4, type, |
| 1188 | auth, auth_len) == NULL) |
| 1189 | { |
| 1190 | logger(ifp->ctx, LOG_DEBUG, |
| 1191 | "%s: dhcp_auth_validate: %m", ifp->name); |
| 1192 | free(dhcp); |
| 1193 | return NULL; |
| 1194 | } |
| 1195 | if (state->auth.token) |
| 1196 | logger(ifp->ctx, LOG_DEBUG, |
| 1197 | "%s: validated using 0x%08" PRIu32, |
| 1198 | ifp->name, state->auth.token->secretid); |
| 1199 | else |
| 1200 | logger(ifp->ctx, LOG_DEBUG, |
| 1201 | "%s: accepted reconfigure key", ifp->name); |
| 1202 | } |
| 1203 | |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1204 | /* |
| 1205 | * DHCP server information is stored after the DHO_END character |
| 1206 | * in the lease file. The first byte of the server information |
| 1207 | * is the length of the gateway hardware address. |
| 1208 | */ |
| 1209 | options_endp = read_buffer + bytes; |
| 1210 | if (options_startp >= options_endp || |
| 1211 | options_startp + sizeof(state->server_info) > options_endp) |
| 1212 | return dhcp; |
| 1213 | |
| 1214 | logger(ifp->ctx, LOG_DEBUG, "%s: found server info in lease '%s'", |
| 1215 | ifp->name, state->leasefile); |
| 1216 | |
| 1217 | memcpy(&state->server_info, options_startp, sizeof(state->server_info)); |
| 1218 | if (state->server_info.gw_hwlen != ifp->hwlen) { |
| 1219 | logger(ifp->ctx, LOG_ERR, "%s: lease file %s has incompatible" |
| 1220 | "MAC address length %d (expected %zd)", |
| 1221 | ifp->name, state->leasefile, |
| 1222 | state->server_info.gw_hwlen, ifp->hwlen); |
| 1223 | memset(&state->server_info, 0, sizeof(state->server_info)); |
| 1224 | } |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1225 | return dhcp; |
| 1226 | } |
| 1227 | |
| 1228 | static const struct dhcp_opt * |
| 1229 | dhcp_getoverride(const struct if_options *ifo, unsigned int o) |
| 1230 | { |
| 1231 | size_t i; |
| 1232 | const struct dhcp_opt *opt; |
| 1233 | |
| 1234 | for (i = 0, opt = ifo->dhcp_override; |
| 1235 | i < ifo->dhcp_override_len; |
| 1236 | i++, opt++) |
| 1237 | { |
| 1238 | if (opt->option == o) |
| 1239 | return opt; |
| 1240 | } |
| 1241 | return NULL; |
| 1242 | } |
| 1243 | |
| 1244 | static const uint8_t * |
| 1245 | dhcp_getoption(struct dhcpcd_ctx *ctx, |
| 1246 | size_t *os, unsigned int *code, size_t *len, |
| 1247 | const uint8_t *od, size_t ol, struct dhcp_opt **oopt) |
| 1248 | { |
| 1249 | size_t i; |
| 1250 | struct dhcp_opt *opt; |
| 1251 | |
| 1252 | if (od) { |
| 1253 | if (ol < 2) { |
| 1254 | errno = EINVAL; |
| 1255 | return NULL; |
| 1256 | } |
| 1257 | *os = 2; /* code + len */ |
| 1258 | *code = (unsigned int)*od++; |
| 1259 | *len = (size_t)*od++; |
Samuel Tan | b745ca9 | 2016-01-08 09:46:36 -0800 | [diff] [blame] | 1260 | if (*len > ol - *os) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1261 | errno = EINVAL; |
| 1262 | return NULL; |
| 1263 | } |
| 1264 | } |
| 1265 | |
Samuel Tan | b745ca9 | 2016-01-08 09:46:36 -0800 | [diff] [blame] | 1266 | *oopt = NULL; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1267 | for (i = 0, opt = ctx->dhcp_opts; i < ctx->dhcp_opts_len; i++, opt++) { |
| 1268 | if (opt->option == *code) { |
| 1269 | *oopt = opt; |
| 1270 | break; |
| 1271 | } |
| 1272 | } |
| 1273 | |
| 1274 | return od; |
| 1275 | } |
| 1276 | |
| 1277 | ssize_t |
| 1278 | dhcp_env(char **env, const char *prefix, const struct dhcp_message *dhcp, |
| 1279 | const struct interface *ifp) |
| 1280 | { |
| 1281 | const struct if_options *ifo; |
| 1282 | const uint8_t *p; |
| 1283 | struct in_addr addr; |
| 1284 | struct in_addr net; |
| 1285 | struct in_addr brd; |
| 1286 | struct dhcp_opt *opt, *vo; |
| 1287 | size_t e, i, pl; |
| 1288 | char **ep; |
| 1289 | char cidr[4], safe[(BOOTFILE_LEN * 4) + 1]; |
| 1290 | uint8_t overl = 0; |
| 1291 | uint32_t en; |
| 1292 | |
| 1293 | e = 0; |
| 1294 | ifo = ifp->options; |
| 1295 | get_option_uint8(ifp->ctx, &overl, dhcp, DHO_OPTIONSOVERLOADED); |
| 1296 | |
| 1297 | if (env == NULL) { |
| 1298 | if (dhcp->yiaddr || dhcp->ciaddr) |
| 1299 | e += 5; |
| 1300 | if (*dhcp->bootfile && !(overl & 1)) |
| 1301 | e++; |
| 1302 | if (*dhcp->servername && !(overl & 2)) |
| 1303 | e++; |
| 1304 | for (i = 0, opt = ifp->ctx->dhcp_opts; |
| 1305 | i < ifp->ctx->dhcp_opts_len; |
| 1306 | i++, opt++) |
| 1307 | { |
| 1308 | if (has_option_mask(ifo->nomask, opt->option)) |
| 1309 | continue; |
| 1310 | if (dhcp_getoverride(ifo, opt->option)) |
| 1311 | continue; |
| 1312 | p = get_option(ifp->ctx, dhcp, opt->option, &pl); |
| 1313 | if (!p) |
| 1314 | continue; |
| 1315 | e += dhcp_envoption(ifp->ctx, NULL, NULL, ifp->name, |
| 1316 | opt, dhcp_getoption, p, pl); |
| 1317 | } |
| 1318 | for (i = 0, opt = ifo->dhcp_override; |
| 1319 | i < ifo->dhcp_override_len; |
| 1320 | i++, opt++) |
| 1321 | { |
| 1322 | if (has_option_mask(ifo->nomask, opt->option)) |
| 1323 | continue; |
| 1324 | p = get_option(ifp->ctx, dhcp, opt->option, &pl); |
| 1325 | if (!p) |
| 1326 | continue; |
| 1327 | e += dhcp_envoption(ifp->ctx, NULL, NULL, ifp->name, |
| 1328 | opt, dhcp_getoption, p, pl); |
| 1329 | } |
| 1330 | return (ssize_t)e; |
| 1331 | } |
| 1332 | |
| 1333 | ep = env; |
| 1334 | if (dhcp->yiaddr || dhcp->ciaddr) { |
| 1335 | /* Set some useful variables that we derive from the DHCP |
| 1336 | * message but are not necessarily in the options */ |
| 1337 | addr.s_addr = dhcp->yiaddr ? dhcp->yiaddr : dhcp->ciaddr; |
| 1338 | setvar(ifp->ctx, &ep, prefix, "ip_address", inet_ntoa(addr)); |
| 1339 | if (get_option_addr(ifp->ctx, &net, |
| 1340 | dhcp, DHO_SUBNETMASK) == -1) { |
| 1341 | net.s_addr = ipv4_getnetmask(addr.s_addr); |
| 1342 | setvar(ifp->ctx, &ep, prefix, |
| 1343 | "subnet_mask", inet_ntoa(net)); |
| 1344 | } |
| 1345 | snprintf(cidr, sizeof(cidr), "%d", inet_ntocidr(net)); |
| 1346 | setvar(ifp->ctx, &ep, prefix, "subnet_cidr", cidr); |
| 1347 | if (get_option_addr(ifp->ctx, &brd, |
| 1348 | dhcp, DHO_BROADCAST) == -1) { |
| 1349 | brd.s_addr = addr.s_addr | ~net.s_addr; |
| 1350 | setvar(ifp->ctx, &ep, prefix, |
| 1351 | "broadcast_address", inet_ntoa(brd)); |
| 1352 | } |
| 1353 | addr.s_addr = dhcp->yiaddr & net.s_addr; |
| 1354 | setvar(ifp->ctx, &ep, prefix, |
| 1355 | "network_number", inet_ntoa(addr)); |
| 1356 | } |
| 1357 | |
| 1358 | if (*dhcp->bootfile && !(overl & 1)) { |
| 1359 | print_string(safe, sizeof(safe), STRING, |
| 1360 | dhcp->bootfile, sizeof(dhcp->bootfile)); |
| 1361 | setvar(ifp->ctx, &ep, prefix, "filename", safe); |
| 1362 | } |
| 1363 | if (*dhcp->servername && !(overl & 2)) { |
| 1364 | print_string(safe, sizeof(safe), STRING | DOMAIN, |
| 1365 | dhcp->servername, sizeof(dhcp->servername)); |
| 1366 | setvar(ifp->ctx, &ep, prefix, "server_name", safe); |
| 1367 | } |
| 1368 | |
| 1369 | /* Zero our indexes */ |
| 1370 | if (env) { |
| 1371 | for (i = 0, opt = ifp->ctx->dhcp_opts; |
| 1372 | i < ifp->ctx->dhcp_opts_len; |
| 1373 | i++, opt++) |
| 1374 | dhcp_zero_index(opt); |
| 1375 | for (i = 0, opt = ifp->options->dhcp_override; |
| 1376 | i < ifp->options->dhcp_override_len; |
| 1377 | i++, opt++) |
| 1378 | dhcp_zero_index(opt); |
| 1379 | for (i = 0, opt = ifp->ctx->vivso; |
| 1380 | i < ifp->ctx->vivso_len; |
| 1381 | i++, opt++) |
| 1382 | dhcp_zero_index(opt); |
| 1383 | } |
| 1384 | |
| 1385 | for (i = 0, opt = ifp->ctx->dhcp_opts; |
| 1386 | i < ifp->ctx->dhcp_opts_len; |
| 1387 | i++, opt++) |
| 1388 | { |
| 1389 | if (has_option_mask(ifo->nomask, opt->option)) |
| 1390 | continue; |
| 1391 | if (dhcp_getoverride(ifo, opt->option)) |
| 1392 | continue; |
| 1393 | if ((p = get_option(ifp->ctx, dhcp, opt->option, &pl))) { |
| 1394 | ep += dhcp_envoption(ifp->ctx, ep, prefix, ifp->name, |
| 1395 | opt, dhcp_getoption, p, pl); |
| 1396 | if (opt->option == DHO_VIVSO && |
| 1397 | pl > (int)sizeof(uint32_t)) |
| 1398 | { |
| 1399 | memcpy(&en, p, sizeof(en)); |
| 1400 | en = ntohl(en); |
| 1401 | vo = vivso_find(en, ifp); |
| 1402 | if (vo) { |
| 1403 | /* Skip over en + total size */ |
| 1404 | p += sizeof(en) + 1; |
| 1405 | pl -= sizeof(en) + 1; |
| 1406 | ep += dhcp_envoption(ifp->ctx, |
| 1407 | ep, prefix, ifp->name, |
| 1408 | vo, dhcp_getoption, p, pl); |
| 1409 | } |
| 1410 | } |
| 1411 | } |
| 1412 | } |
| 1413 | |
| 1414 | for (i = 0, opt = ifo->dhcp_override; |
| 1415 | i < ifo->dhcp_override_len; |
| 1416 | i++, opt++) |
| 1417 | { |
| 1418 | if (has_option_mask(ifo->nomask, opt->option)) |
| 1419 | continue; |
| 1420 | if ((p = get_option(ifp->ctx, dhcp, opt->option, &pl))) |
| 1421 | ep += dhcp_envoption(ifp->ctx, ep, prefix, ifp->name, |
| 1422 | opt, dhcp_getoption, p, pl); |
| 1423 | } |
| 1424 | |
| 1425 | return ep - env; |
| 1426 | } |
| 1427 | |
| 1428 | static void |
| 1429 | get_lease(struct dhcpcd_ctx *ctx, |
| 1430 | struct dhcp_lease *lease, const struct dhcp_message *dhcp) |
| 1431 | { |
| 1432 | |
| 1433 | lease->cookie = dhcp->cookie; |
| 1434 | /* BOOTP does not set yiaddr for replies when ciaddr is set. */ |
| 1435 | if (dhcp->yiaddr) |
| 1436 | lease->addr.s_addr = dhcp->yiaddr; |
| 1437 | else |
| 1438 | lease->addr.s_addr = dhcp->ciaddr; |
| 1439 | if (get_option_addr(ctx, &lease->net, dhcp, DHO_SUBNETMASK) == -1) |
| 1440 | lease->net.s_addr = ipv4_getnetmask(lease->addr.s_addr); |
| 1441 | if (get_option_addr(ctx, &lease->brd, dhcp, DHO_BROADCAST) == -1) |
| 1442 | lease->brd.s_addr = lease->addr.s_addr | ~lease->net.s_addr; |
| 1443 | if (get_option_uint32(ctx, &lease->leasetime, dhcp, DHO_LEASETIME) != 0) |
| 1444 | lease->leasetime = ~0U; /* Default to infinite lease */ |
| 1445 | if (get_option_uint32(ctx, &lease->renewaltime, |
| 1446 | dhcp, DHO_RENEWALTIME) != 0) |
| 1447 | lease->renewaltime = 0; |
| 1448 | if (get_option_uint32(ctx, &lease->rebindtime, |
| 1449 | dhcp, DHO_REBINDTIME) != 0) |
| 1450 | lease->rebindtime = 0; |
| 1451 | if (get_option_addr(ctx, &lease->server, dhcp, DHO_SERVERID) != 0) |
| 1452 | lease->server.s_addr = INADDR_ANY; |
| 1453 | } |
| 1454 | |
| 1455 | static const char * |
| 1456 | get_dhcp_op(uint8_t type) |
| 1457 | { |
| 1458 | const struct dhcp_op *d; |
| 1459 | |
| 1460 | for (d = dhcp_ops; d->name; d++) |
| 1461 | if (d->value == type) |
| 1462 | return d->name; |
| 1463 | return NULL; |
| 1464 | } |
| 1465 | |
| 1466 | static void |
| 1467 | dhcp_fallback(void *arg) |
| 1468 | { |
| 1469 | struct interface *iface; |
| 1470 | |
| 1471 | iface = (struct interface *)arg; |
| 1472 | dhcpcd_selectprofile(iface, iface->options->fallback); |
| 1473 | dhcpcd_startinterface(iface); |
| 1474 | } |
| 1475 | |
| 1476 | uint32_t |
| 1477 | dhcp_xid(const struct interface *ifp) |
| 1478 | { |
| 1479 | uint32_t xid; |
| 1480 | |
| 1481 | if (ifp->options->options & DHCPCD_XID_HWADDR && |
| 1482 | ifp->hwlen >= sizeof(xid)) |
| 1483 | /* The lower bits are probably more unique on the network */ |
| 1484 | memcpy(&xid, (ifp->hwaddr + ifp->hwlen) - sizeof(xid), |
| 1485 | sizeof(xid)); |
| 1486 | else |
| 1487 | xid = arc4random(); |
| 1488 | |
| 1489 | return xid; |
| 1490 | } |
| 1491 | |
| 1492 | void |
| 1493 | dhcp_close(struct interface *ifp) |
| 1494 | { |
| 1495 | struct dhcp_state *state = D_STATE(ifp); |
| 1496 | |
| 1497 | if (state == NULL) |
| 1498 | return; |
| 1499 | |
| 1500 | if (state->raw_fd != -1) { |
| 1501 | eloop_event_delete(ifp->ctx->eloop, state->raw_fd, 0); |
| 1502 | close(state->raw_fd); |
| 1503 | state->raw_fd = -1; |
| 1504 | } |
| 1505 | |
| 1506 | state->interval = 0; |
| 1507 | } |
| 1508 | |
| 1509 | static int |
| 1510 | dhcp_openudp(struct interface *ifp) |
| 1511 | { |
| 1512 | int s; |
| 1513 | struct sockaddr_in sin; |
| 1514 | int n; |
| 1515 | struct dhcp_state *state; |
| 1516 | #ifdef SO_BINDTODEVICE |
| 1517 | struct ifreq ifr; |
| 1518 | char *p; |
| 1519 | #endif |
| 1520 | |
| 1521 | #ifdef SOCK_CLOEXEC |
| 1522 | if ((s = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP)) == -1) |
| 1523 | return -1; |
| 1524 | #else |
| 1525 | if ((s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) |
| 1526 | return -1; |
| 1527 | if ((n = fcntl(s, F_GETFD, 0)) == -1 || |
| 1528 | fcntl(s, F_SETFD, n | FD_CLOEXEC) == -1) |
| 1529 | { |
| 1530 | close(s); |
| 1531 | return -1; |
| 1532 | } |
| 1533 | #endif |
| 1534 | |
| 1535 | n = 1; |
| 1536 | if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &n, sizeof(n)) == -1) |
| 1537 | goto eexit; |
| 1538 | #ifdef SO_BINDTODEVICE |
| 1539 | if (ifp) { |
| 1540 | memset(&ifr, 0, sizeof(ifr)); |
| 1541 | strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name)); |
| 1542 | /* We can only bind to the real device */ |
| 1543 | p = strchr(ifr.ifr_name, ':'); |
| 1544 | if (p) |
| 1545 | *p = '\0'; |
| 1546 | if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, &ifr, |
| 1547 | sizeof(ifr)) == -1) |
| 1548 | goto eexit; |
| 1549 | } |
| 1550 | #endif |
| 1551 | memset(&sin, 0, sizeof(sin)); |
| 1552 | sin.sin_family = AF_INET; |
| 1553 | sin.sin_port = htons(DHCP_CLIENT_PORT); |
| 1554 | if (ifp) { |
| 1555 | state = D_STATE(ifp); |
| 1556 | sin.sin_addr.s_addr = state->addr.s_addr; |
| 1557 | } else |
| 1558 | state = NULL; /* appease gcc */ |
| 1559 | if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) == -1) |
| 1560 | goto eexit; |
| 1561 | |
| 1562 | return s; |
| 1563 | |
| 1564 | eexit: |
| 1565 | close(s); |
| 1566 | return -1; |
| 1567 | } |
| 1568 | |
| 1569 | static uint16_t |
| 1570 | checksum(const void *data, unsigned int len) |
| 1571 | { |
| 1572 | const uint8_t *addr = data; |
| 1573 | uint32_t sum = 0; |
| 1574 | |
| 1575 | while (len > 1) { |
| 1576 | sum += (uint32_t)(addr[0] * 256 + addr[1]); |
| 1577 | addr += 2; |
| 1578 | len -= 2; |
| 1579 | } |
| 1580 | |
| 1581 | if (len == 1) |
| 1582 | sum += (uint32_t)(*addr * 256); |
| 1583 | |
| 1584 | sum = (sum >> 16) + (sum & 0xffff); |
| 1585 | sum += (sum >> 16); |
| 1586 | |
| 1587 | return (uint16_t)~htons((uint16_t)sum); |
| 1588 | } |
| 1589 | |
| 1590 | static struct udp_dhcp_packet * |
| 1591 | dhcp_makeudppacket(size_t *sz, const uint8_t *data, size_t length, |
| 1592 | struct in_addr source, struct in_addr dest) |
| 1593 | { |
| 1594 | struct udp_dhcp_packet *udpp; |
| 1595 | struct ip *ip; |
| 1596 | struct udphdr *udp; |
| 1597 | |
| 1598 | udpp = calloc(1, sizeof(*udpp)); |
| 1599 | if (udpp == NULL) |
| 1600 | return NULL; |
| 1601 | ip = &udpp->ip; |
| 1602 | udp = &udpp->udp; |
| 1603 | |
| 1604 | /* OK, this is important :) |
| 1605 | * We copy the data to our packet and then create a small part of the |
| 1606 | * ip structure and an invalid ip_len (basically udp length). |
| 1607 | * We then fill the udp structure and put the checksum |
| 1608 | * of the whole packet into the udp checksum. |
| 1609 | * Finally we complete the ip structure and ip checksum. |
| 1610 | * If we don't do the ordering like so then the udp checksum will be |
| 1611 | * broken, so find another way of doing it! */ |
| 1612 | |
| 1613 | memcpy(&udpp->dhcp, data, length); |
| 1614 | |
| 1615 | ip->ip_p = IPPROTO_UDP; |
| 1616 | ip->ip_src.s_addr = source.s_addr; |
| 1617 | if (dest.s_addr == 0) |
| 1618 | ip->ip_dst.s_addr = INADDR_BROADCAST; |
| 1619 | else |
| 1620 | ip->ip_dst.s_addr = dest.s_addr; |
| 1621 | |
| 1622 | udp->uh_sport = htons(DHCP_CLIENT_PORT); |
| 1623 | udp->uh_dport = htons(DHCP_SERVER_PORT); |
| 1624 | udp->uh_ulen = htons((uint16_t)(sizeof(*udp) + length)); |
| 1625 | ip->ip_len = udp->uh_ulen; |
| 1626 | udp->uh_sum = checksum(udpp, sizeof(*udpp)); |
| 1627 | |
| 1628 | ip->ip_v = IPVERSION; |
| 1629 | ip->ip_hl = sizeof(*ip) >> 2; |
| 1630 | ip->ip_id = (uint16_t)arc4random_uniform(UINT16_MAX); |
| 1631 | ip->ip_ttl = IPDEFTTL; |
| 1632 | ip->ip_len = htons((uint16_t)(sizeof(*ip) + sizeof(*udp) + length)); |
| 1633 | ip->ip_sum = checksum(ip, sizeof(*ip)); |
| 1634 | |
| 1635 | *sz = sizeof(*ip) + sizeof(*udp) + length; |
| 1636 | return udpp; |
| 1637 | } |
| 1638 | |
| 1639 | static void |
| 1640 | send_message(struct interface *ifp, uint8_t type, |
| 1641 | void (*callback)(void *)) |
| 1642 | { |
| 1643 | struct dhcp_state *state = D_STATE(ifp); |
| 1644 | struct if_options *ifo = ifp->options; |
| 1645 | struct dhcp_message *dhcp; |
| 1646 | struct udp_dhcp_packet *udp; |
| 1647 | size_t len; |
| 1648 | ssize_t r; |
| 1649 | struct in_addr from, to; |
| 1650 | in_addr_t a = INADDR_ANY; |
| 1651 | struct timespec tv; |
| 1652 | int s; |
| 1653 | #ifdef IN_IFF_NOTUSEABLE |
| 1654 | struct ipv4_addr *ia; |
| 1655 | #endif |
| 1656 | |
| 1657 | if (!callback) |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 1658 | logger(ifp->ctx, LOG_INFO, "%s: sending %s with xid 0x%x", |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1659 | ifp->name, |
| 1660 | ifo->options & DHCPCD_BOOTP ? "BOOTP" : get_dhcp_op(type), |
| 1661 | state->xid); |
| 1662 | else { |
| 1663 | if (state->interval == 0) |
Samuel Tan | e942e09 | 2015-08-13 17:14:37 -0700 | [diff] [blame] | 1664 | state->interval = DHCP_BASE; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1665 | else { |
| 1666 | state->interval *= 2; |
Samuel Tan | e942e09 | 2015-08-13 17:14:37 -0700 | [diff] [blame] | 1667 | if (state->interval > DHCP_MAX) |
| 1668 | state->interval = DHCP_MAX; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1669 | } |
| 1670 | tv.tv_sec = state->interval + DHCP_RAND_MIN; |
| 1671 | tv.tv_nsec = (suseconds_t)arc4random_uniform( |
| 1672 | (DHCP_RAND_MAX - DHCP_RAND_MIN) * NSEC_PER_SEC); |
| 1673 | timespecnorm(&tv); |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 1674 | logger(ifp->ctx, LOG_INFO, |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1675 | "%s: sending %s (xid 0x%x), next in %0.1f seconds", |
| 1676 | ifp->name, |
| 1677 | ifo->options & DHCPCD_BOOTP ? "BOOTP" : get_dhcp_op(type), |
| 1678 | state->xid, |
| 1679 | timespec_to_double(&tv)); |
| 1680 | } |
| 1681 | |
| 1682 | if (dhcp_open(ifp) == -1) |
| 1683 | return; |
| 1684 | |
| 1685 | if (state->added && !(state->added & STATE_FAKE) && |
| 1686 | state->addr.s_addr != INADDR_ANY && |
| 1687 | state->new != NULL && |
| 1688 | #ifdef IN_IFF_NOTUSEABLE |
| 1689 | ((ia = ipv4_iffindaddr(ifp, &state->addr, NULL)) && |
| 1690 | !(ia->addr_flags & IN_IFF_NOTUSEABLE)) && |
| 1691 | #endif |
| 1692 | (state->new->cookie == htonl(MAGIC_COOKIE) || |
| 1693 | ifp->options->options & DHCPCD_INFORM)) |
| 1694 | { |
| 1695 | s = dhcp_openudp(ifp); |
| 1696 | if (s == -1 && errno != EADDRINUSE) |
| 1697 | logger(ifp->ctx, LOG_ERR, |
| 1698 | "%s: dhcp_openudp: %m", ifp->name); |
| 1699 | } else |
| 1700 | s = -1; |
| 1701 | |
| 1702 | /* If we couldn't open a UDP port for our IP address |
| 1703 | * then we cannot renew. |
| 1704 | * This could happen if our IP was pulled out from underneath us. |
| 1705 | * Also, we should not unicast from a BOOTP lease. */ |
| 1706 | if (s == -1 || |
| 1707 | (!(ifo->options & DHCPCD_INFORM) && |
| 1708 | IS_BOOTP(ifp, state->new))) |
| 1709 | { |
| 1710 | a = state->addr.s_addr; |
| 1711 | state->addr.s_addr = INADDR_ANY; |
| 1712 | } |
| 1713 | r = make_message(&dhcp, ifp, type); |
| 1714 | if (r == -1) |
| 1715 | goto fail; |
| 1716 | len = (size_t)r; |
| 1717 | if (a) |
| 1718 | state->addr.s_addr = a; |
| 1719 | from.s_addr = dhcp->ciaddr; |
| 1720 | if (from.s_addr) |
| 1721 | to.s_addr = state->lease.server.s_addr; |
| 1722 | else |
| 1723 | to.s_addr = INADDR_ANY; |
| 1724 | if (to.s_addr && to.s_addr != INADDR_BROADCAST) { |
| 1725 | struct sockaddr_in sin; |
| 1726 | |
| 1727 | memset(&sin, 0, sizeof(sin)); |
| 1728 | sin.sin_family = AF_INET; |
| 1729 | sin.sin_addr.s_addr = to.s_addr; |
| 1730 | sin.sin_port = htons(DHCP_SERVER_PORT); |
| 1731 | r = sendto(s, (uint8_t *)dhcp, len, 0, |
| 1732 | (struct sockaddr *)&sin, sizeof(sin)); |
| 1733 | if (r == -1) |
| 1734 | logger(ifp->ctx, LOG_ERR, |
| 1735 | "%s: dhcp_sendpacket: %m", ifp->name); |
| 1736 | } else { |
| 1737 | size_t ulen; |
| 1738 | |
| 1739 | r = 0; |
| 1740 | udp = dhcp_makeudppacket(&ulen, (uint8_t *)dhcp, len, from, to); |
| 1741 | if (udp == NULL) { |
| 1742 | logger(ifp->ctx, LOG_ERR, "dhcp_makeudppacket: %m"); |
| 1743 | } else { |
| 1744 | r = if_sendrawpacket(ifp, ETHERTYPE_IP, |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 1745 | (uint8_t *)udp, ulen, NULL); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1746 | free(udp); |
| 1747 | } |
| 1748 | /* If we failed to send a raw packet this normally means |
| 1749 | * we don't have the ability to work beneath the IP layer |
| 1750 | * for this interface. |
| 1751 | * As such we remove it from consideration without actually |
| 1752 | * stopping the interface. */ |
| 1753 | if (r == -1) { |
| 1754 | logger(ifp->ctx, LOG_ERR, |
| 1755 | "%s: if_sendrawpacket: %m", ifp->name); |
| 1756 | switch(errno) { |
| 1757 | case ENETDOWN: |
| 1758 | case ENETRESET: |
| 1759 | case ENETUNREACH: |
| 1760 | break; |
| 1761 | default: |
| 1762 | if (!(ifp->ctx->options & DHCPCD_TEST)) |
| 1763 | dhcp_drop(ifp, "FAIL"); |
| 1764 | dhcp_free(ifp); |
| 1765 | eloop_timeout_delete(ifp->ctx->eloop, |
| 1766 | NULL, ifp); |
| 1767 | callback = NULL; |
| 1768 | } |
| 1769 | } |
| 1770 | } |
| 1771 | free(dhcp); |
| 1772 | |
| 1773 | fail: |
| 1774 | if (s != -1) |
| 1775 | close(s); |
| 1776 | |
| 1777 | /* Even if we fail to send a packet we should continue as we are |
| 1778 | * as our failure timeouts will change out codepath when needed. */ |
| 1779 | if (callback) |
| 1780 | eloop_timeout_add_tv(ifp->ctx->eloop, &tv, callback, ifp); |
| 1781 | } |
| 1782 | |
| 1783 | static void |
| 1784 | send_inform(void *arg) |
| 1785 | { |
| 1786 | |
| 1787 | send_message((struct interface *)arg, DHCP_INFORM, send_inform); |
| 1788 | } |
| 1789 | |
| 1790 | static void |
| 1791 | send_discover(void *arg) |
| 1792 | { |
| 1793 | |
| 1794 | send_message((struct interface *)arg, DHCP_DISCOVER, send_discover); |
| 1795 | } |
| 1796 | |
| 1797 | static void |
| 1798 | send_request(void *arg) |
| 1799 | { |
| 1800 | |
| 1801 | send_message((struct interface *)arg, DHCP_REQUEST, send_request); |
| 1802 | } |
| 1803 | |
| 1804 | static void |
| 1805 | send_renew(void *arg) |
| 1806 | { |
| 1807 | |
| 1808 | send_message((struct interface *)arg, DHCP_REQUEST, send_renew); |
| 1809 | } |
| 1810 | |
| 1811 | static void |
| 1812 | send_rebind(void *arg) |
| 1813 | { |
| 1814 | |
| 1815 | send_message((struct interface *)arg, DHCP_REQUEST, send_rebind); |
| 1816 | } |
| 1817 | |
| 1818 | void |
| 1819 | dhcp_discover(void *arg) |
| 1820 | { |
| 1821 | struct interface *ifp = arg; |
| 1822 | struct dhcp_state *state = D_STATE(ifp); |
| 1823 | struct if_options *ifo = ifp->options; |
| 1824 | |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 1825 | rpc_signal_status("Discover"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1826 | state->state = DHS_DISCOVER; |
| 1827 | state->xid = dhcp_xid(ifp); |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 1828 | state->nak_receive_count = 0; |
| 1829 | state->failed_address_offer_count = 0; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1830 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 1831 | if (ifo->fallback) |
| 1832 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 1833 | ifo->reboot, dhcp_fallback, ifp); |
| 1834 | else if (ifo->options & DHCPCD_IPV4LL && |
| 1835 | !IN_LINKLOCAL(htonl(state->addr.s_addr))) |
| 1836 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 1837 | ifo->reboot, ipv4ll_start, ifp); |
| 1838 | if (ifo->options & DHCPCD_REQUEST) |
| 1839 | logger(ifp->ctx, LOG_INFO, |
| 1840 | "%s: soliciting a DHCP lease (requesting %s)", |
| 1841 | ifp->name, inet_ntoa(ifo->req_addr)); |
| 1842 | else |
| 1843 | logger(ifp->ctx, LOG_INFO, |
| 1844 | "%s: soliciting a %s lease", |
| 1845 | ifp->name, ifo->options & DHCPCD_BOOTP ? "BOOTP" : "DHCP"); |
| 1846 | send_discover(ifp); |
| 1847 | } |
| 1848 | |
| 1849 | static void |
| 1850 | dhcp_request(void *arg) |
| 1851 | { |
| 1852 | struct interface *ifp = arg; |
| 1853 | struct dhcp_state *state = D_STATE(ifp); |
| 1854 | |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 1855 | logger(ifp->ctx, LOG_INFO, "%s: requesting lease of %s", |
| 1856 | ifp->name, inet_ntoa(state->lease.addr)); |
| 1857 | |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 1858 | rpc_signal_status("Request"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1859 | state->state = DHS_REQUEST; |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 1860 | state->nak_receive_count = 0; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1861 | send_request(ifp); |
| 1862 | } |
| 1863 | |
| 1864 | static void |
| 1865 | dhcp_expire(void *arg) |
| 1866 | { |
| 1867 | struct interface *ifp = arg; |
| 1868 | struct dhcp_state *state = D_STATE(ifp); |
| 1869 | |
| 1870 | logger(ifp->ctx, LOG_ERR, "%s: DHCP lease expired", ifp->name); |
| 1871 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 1872 | dhcp_drop(ifp, "EXPIRE"); |
| 1873 | unlink(state->leasefile); |
| 1874 | state->interval = 0; |
| 1875 | dhcp_discover(ifp); |
| 1876 | } |
| 1877 | |
| 1878 | static void |
| 1879 | dhcp_decline(struct interface *ifp) |
| 1880 | { |
| 1881 | |
| 1882 | send_message(ifp, DHCP_DECLINE, NULL); |
| 1883 | } |
| 1884 | |
| 1885 | static void |
| 1886 | dhcp_renew(void *arg) |
| 1887 | { |
| 1888 | struct interface *ifp = arg; |
| 1889 | struct dhcp_state *state = D_STATE(ifp); |
| 1890 | struct dhcp_lease *lease = &state->lease; |
| 1891 | |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 1892 | rpc_signal_status("Renew"); |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 1893 | logger(ifp->ctx, LOG_INFO, "%s: renewing lease of %s", |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1894 | ifp->name, inet_ntoa(lease->addr)); |
| 1895 | logger(ifp->ctx, LOG_DEBUG, "%s: rebind in %"PRIu32" seconds," |
| 1896 | " expire in %"PRIu32" seconds", |
| 1897 | ifp->name, lease->rebindtime - lease->renewaltime, |
| 1898 | lease->leasetime - lease->renewaltime); |
| 1899 | state->state = DHS_RENEW; |
| 1900 | state->xid = dhcp_xid(ifp); |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 1901 | state->nak_receive_count = 0; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1902 | send_renew(ifp); |
| 1903 | } |
| 1904 | |
| 1905 | #ifndef IN_IFF_TENTATIVE |
| 1906 | static void |
| 1907 | dhcp_arp_announced(struct arp_state *astate) |
| 1908 | { |
| 1909 | |
| 1910 | arp_close(astate->iface); |
| 1911 | } |
| 1912 | #endif |
| 1913 | |
| 1914 | static void |
| 1915 | dhcp_rebind(void *arg) |
| 1916 | { |
| 1917 | struct interface *ifp = arg; |
| 1918 | struct dhcp_state *state = D_STATE(ifp); |
| 1919 | struct dhcp_lease *lease = &state->lease; |
| 1920 | |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 1921 | rpc_signal_status("Rebind"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1922 | logger(ifp->ctx, LOG_WARNING, |
| 1923 | "%s: failed to renew DHCP, rebinding", ifp->name); |
| 1924 | logger(ifp->ctx, LOG_DEBUG, "%s: expire in %"PRIu32" seconds", |
| 1925 | ifp->name, lease->leasetime - lease->rebindtime); |
| 1926 | state->state = DHS_REBIND; |
| 1927 | eloop_timeout_delete(ifp->ctx->eloop, send_renew, ifp); |
| 1928 | state->lease.server.s_addr = 0; |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 1929 | state->nak_receive_count = 0; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 1930 | ifp->options->options &= ~(DHCPCD_CSR_WARNED | |
| 1931 | DHCPCD_ROUTER_HOST_ROUTE_WARNED); |
| 1932 | send_rebind(ifp); |
| 1933 | } |
| 1934 | |
Samuel Tan | 9177c6f | 2015-08-13 16:47:36 -0700 | [diff] [blame] | 1935 | static void |
| 1936 | init_option_iterator(const struct dhcp_message *message, |
| 1937 | struct dhcp_option_iterator *iterator) |
| 1938 | { |
| 1939 | iterator->message = message; |
| 1940 | iterator->ptr = message->options; |
| 1941 | iterator->end = iterator->ptr + sizeof(message->options); |
| 1942 | iterator->extra_option_locations = 0; |
| 1943 | iterator->extra_option_locations_set = 0; |
| 1944 | } |
| 1945 | |
| 1946 | static int |
| 1947 | iterate_next_option(struct dhcp_option_iterator *iterator, |
| 1948 | uint8_t *option, uint8_t *length, const uint8_t **value) |
| 1949 | { |
| 1950 | uint8_t option_code; |
| 1951 | uint8_t option_len; |
| 1952 | |
| 1953 | /* Process special DHO_PAD and DHO_END opcodes. */ |
| 1954 | while (iterator->ptr < iterator->end) { |
| 1955 | if (*iterator->ptr == DHO_PAD) { |
| 1956 | iterator->ptr++; |
| 1957 | continue; |
| 1958 | } |
| 1959 | |
| 1960 | if (*iterator->ptr != DHO_END) |
| 1961 | break; |
| 1962 | |
| 1963 | if (iterator->extra_option_locations & |
| 1964 | OPTION_OVERLOADED_BOOT_FILE) { |
| 1965 | iterator->extra_option_locations &= |
| 1966 | ~OPTION_OVERLOADED_BOOT_FILE; |
| 1967 | iterator->ptr = iterator->message->bootfile; |
| 1968 | iterator->end = iterator->ptr + |
| 1969 | sizeof(iterator->message->bootfile); |
| 1970 | } else if (iterator->extra_option_locations & |
| 1971 | OPTION_OVERLOADED_SERVER_NAME) { |
| 1972 | iterator->extra_option_locations &= |
| 1973 | ~OPTION_OVERLOADED_SERVER_NAME; |
| 1974 | iterator->ptr = iterator->message->servername; |
| 1975 | iterator->end = iterator->ptr + |
| 1976 | sizeof(iterator->message->servername); |
| 1977 | } else |
| 1978 | return 0; |
| 1979 | } |
| 1980 | |
| 1981 | if (iterator->ptr + 2 > iterator->end) |
| 1982 | return 0; |
| 1983 | |
| 1984 | option_code = *iterator->ptr++; |
| 1985 | option_len = *iterator->ptr++; |
| 1986 | if (iterator->ptr + option_len > iterator->end) |
| 1987 | return 0; |
| 1988 | |
| 1989 | if (option_code == DHO_OPTIONSOVERLOADED && option_len > 0 && |
| 1990 | !iterator->extra_option_locations_set) { |
| 1991 | iterator->extra_option_locations = *iterator->ptr; |
| 1992 | iterator->extra_option_locations_set = 1; |
| 1993 | } |
| 1994 | |
| 1995 | if (option) |
| 1996 | *option = option_code; |
| 1997 | if (length) |
| 1998 | *length = option_len; |
| 1999 | if (value) |
| 2000 | *value = iterator->ptr; |
| 2001 | |
| 2002 | iterator->ptr += option_len; |
| 2003 | |
| 2004 | return 1; |
| 2005 | } |
| 2006 | |
| 2007 | static void |
| 2008 | merge_option_values(const struct dhcp_message *src, |
| 2009 | struct dhcp_message *dst, uint8_t *copy_options) |
| 2010 | { |
| 2011 | uint8_t supplied_options[OPTION_MASK_SIZE]; |
| 2012 | struct dhcp_option_iterator dst_iterator; |
| 2013 | struct dhcp_option_iterator src_iterator; |
| 2014 | uint8_t option; |
| 2015 | const uint8_t *option_value; |
| 2016 | uint8_t option_length; |
| 2017 | uint8_t *out; |
| 2018 | const uint8_t *out_end; |
| 2019 | int added_options = 0; |
| 2020 | |
| 2021 | /* Traverse the destination message for options already supplied. */ |
| 2022 | memset(&supplied_options, 0, sizeof(supplied_options)); |
| 2023 | init_option_iterator(dst, &dst_iterator); |
| 2024 | while (iterate_next_option(&dst_iterator, &option, NULL, NULL)) { |
| 2025 | add_option_mask(supplied_options, option); |
| 2026 | } |
| 2027 | |
| 2028 | /* We will start merging options at the end of the last block |
| 2029 | * the iterator traversed to. The const cast below is safe since |
| 2030 | * this points to data within the (non-const) dst message. */ |
| 2031 | out = (uint8_t *) dst_iterator.ptr; |
| 2032 | out_end = dst_iterator.end; |
| 2033 | |
| 2034 | init_option_iterator(src, &src_iterator); |
| 2035 | while (iterate_next_option(&src_iterator, &option, &option_length, |
| 2036 | &option_value)) { |
| 2037 | if (has_option_mask(supplied_options, option) || |
| 2038 | !has_option_mask(copy_options, option)) |
| 2039 | continue; |
| 2040 | /* We need space for this option, plus a trailing DHO_END. */ |
| 2041 | if (out + option_length + 3 > out_end) { |
| 2042 | syslog(LOG_ERR, |
| 2043 | "%s: unable to fit option %d (length %d)", |
| 2044 | __func__, option, option_length); |
| 2045 | continue; |
| 2046 | } |
| 2047 | *out++ = option; |
| 2048 | *out++ = option_length; |
| 2049 | memcpy(out, option_value, option_length); |
| 2050 | out += option_length; |
| 2051 | added_options++; |
| 2052 | } |
| 2053 | |
| 2054 | if (added_options) { |
| 2055 | *out++ = DHO_END; |
| 2056 | syslog(LOG_INFO, "carrying over %d options from original offer", |
| 2057 | added_options); |
| 2058 | } |
| 2059 | } |
| 2060 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2061 | void |
| 2062 | dhcp_bind(struct interface *ifp, struct arp_state *astate) |
| 2063 | { |
| 2064 | struct dhcp_state *state = D_STATE(ifp); |
| 2065 | struct if_options *ifo = ifp->options; |
| 2066 | struct dhcp_lease *lease = &state->lease; |
| 2067 | uint8_t ipv4ll = 0; |
| 2068 | |
| 2069 | if (state->state == DHS_BOUND) |
| 2070 | goto applyaddr; |
| 2071 | state->reason = NULL; |
| 2072 | free(state->old); |
| 2073 | state->old = state->new; |
| 2074 | state->new = state->offer; |
| 2075 | state->offer = NULL; |
| 2076 | get_lease(ifp->ctx, lease, state->new); |
| 2077 | if (ifo->options & DHCPCD_STATIC) { |
| 2078 | logger(ifp->ctx, LOG_INFO, "%s: using static address %s/%d", |
| 2079 | ifp->name, inet_ntoa(lease->addr), |
| 2080 | inet_ntocidr(lease->net)); |
| 2081 | lease->leasetime = ~0U; |
| 2082 | state->reason = "STATIC"; |
| 2083 | } else if (state->new->cookie != htonl(MAGIC_COOKIE)) { |
| 2084 | logger(ifp->ctx, LOG_INFO, "%s: using IPv4LL address %s", |
| 2085 | ifp->name, inet_ntoa(lease->addr)); |
| 2086 | lease->leasetime = ~0U; |
| 2087 | state->reason = "IPV4LL"; |
| 2088 | ipv4ll = 1; |
| 2089 | } else if (ifo->options & DHCPCD_INFORM) { |
| 2090 | if (ifo->req_addr.s_addr != 0) |
| 2091 | lease->addr.s_addr = ifo->req_addr.s_addr; |
| 2092 | else |
| 2093 | lease->addr.s_addr = state->addr.s_addr; |
| 2094 | logger(ifp->ctx, LOG_INFO, "%s: received approval for %s", |
| 2095 | ifp->name, inet_ntoa(lease->addr)); |
| 2096 | lease->leasetime = ~0U; |
| 2097 | state->reason = "INFORM"; |
| 2098 | } else { |
| 2099 | if (lease->frominfo) |
| 2100 | state->reason = "TIMEOUT"; |
| 2101 | if (lease->leasetime == ~0U) { |
| 2102 | lease->renewaltime = |
| 2103 | lease->rebindtime = |
| 2104 | lease->leasetime; |
| 2105 | logger(ifp->ctx, LOG_INFO, "%s: leased %s for infinity", |
| 2106 | ifp->name, inet_ntoa(lease->addr)); |
| 2107 | } else { |
| 2108 | if (lease->leasetime < DHCP_MIN_LEASE) { |
| 2109 | logger(ifp->ctx, LOG_WARNING, |
| 2110 | "%s: minimum lease is %d seconds", |
| 2111 | ifp->name, DHCP_MIN_LEASE); |
| 2112 | lease->leasetime = DHCP_MIN_LEASE; |
| 2113 | } |
| 2114 | if (lease->rebindtime == 0) |
| 2115 | lease->rebindtime = |
| 2116 | (uint32_t)(lease->leasetime * T2); |
| 2117 | else if (lease->rebindtime >= lease->leasetime) { |
| 2118 | lease->rebindtime = |
| 2119 | (uint32_t)(lease->leasetime * T2); |
| 2120 | logger(ifp->ctx, LOG_WARNING, |
| 2121 | "%s: rebind time greater than lease " |
| 2122 | "time, forcing to %"PRIu32" seconds", |
| 2123 | ifp->name, lease->rebindtime); |
| 2124 | } |
| 2125 | if (lease->renewaltime == 0) |
| 2126 | lease->renewaltime = |
| 2127 | (uint32_t)(lease->leasetime * T1); |
| 2128 | else if (lease->renewaltime > lease->rebindtime) { |
| 2129 | lease->renewaltime = |
| 2130 | (uint32_t)(lease->leasetime * T1); |
| 2131 | logger(ifp->ctx, LOG_WARNING, |
| 2132 | "%s: renewal time greater than rebind " |
| 2133 | "time, forcing to %"PRIu32" seconds", |
| 2134 | ifp->name, lease->renewaltime); |
| 2135 | } |
| 2136 | logger(ifp->ctx, |
| 2137 | lease->addr.s_addr == state->addr.s_addr && |
| 2138 | !(state->added & STATE_FAKE) ? |
| 2139 | LOG_DEBUG : LOG_INFO, |
| 2140 | "%s: leased %s for %"PRIu32" seconds", ifp->name, |
| 2141 | inet_ntoa(lease->addr), lease->leasetime); |
| 2142 | } |
| 2143 | } |
| 2144 | if (ifp->ctx->options & DHCPCD_TEST) { |
| 2145 | state->reason = "TEST"; |
| 2146 | script_runreason(ifp, state->reason); |
| 2147 | eloop_exit(ifp->ctx->eloop, EXIT_SUCCESS); |
| 2148 | return; |
| 2149 | } |
| 2150 | if (state->reason == NULL) { |
| 2151 | if (state->old && !(state->added & STATE_FAKE)) { |
| 2152 | if (state->old->yiaddr == state->new->yiaddr && |
| 2153 | lease->server.s_addr) |
| 2154 | state->reason = "RENEW"; |
| 2155 | else |
| 2156 | state->reason = "REBIND"; |
| 2157 | } else if (state->state == DHS_REBOOT) |
| 2158 | state->reason = "REBOOT"; |
| 2159 | else |
| 2160 | state->reason = "BOUND"; |
| 2161 | } |
Samuel Tan | 9177c6f | 2015-08-13 16:47:36 -0700 | [diff] [blame] | 2162 | |
| 2163 | if (state->old && state->old->yiaddr == state->new->yiaddr && |
| 2164 | (state->state == DHS_REBOOT || state->state == DHS_RENEW || |
| 2165 | state->state == DHS_REBIND)) { |
| 2166 | /* Some DHCP servers respond to REQUEST with a subset |
| 2167 | * of the original requested parameters. If they were not |
| 2168 | * supplied in the response to a renewal, we should assume |
| 2169 | * that it's reasonable to transfer them forward from the |
| 2170 | * original offer. */ |
| 2171 | merge_option_values(state->old, state->new, ifo->requestmask); |
| 2172 | } |
| 2173 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2174 | if (lease->leasetime == ~0U) |
| 2175 | lease->renewaltime = lease->rebindtime = lease->leasetime; |
| 2176 | else { |
| 2177 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2178 | (time_t)lease->renewaltime, dhcp_renew, ifp); |
| 2179 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2180 | (time_t)lease->rebindtime, dhcp_rebind, ifp); |
| 2181 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2182 | (time_t)lease->leasetime, dhcp_expire, ifp); |
| 2183 | logger(ifp->ctx, LOG_DEBUG, |
| 2184 | "%s: renew in %"PRIu32" seconds, rebind in %"PRIu32 |
| 2185 | " seconds", |
| 2186 | ifp->name, lease->renewaltime, lease->rebindtime); |
| 2187 | } |
| 2188 | if (!(ifo->options & DHCPCD_STATIC) && |
| 2189 | state->new->cookie != htonl(MAGIC_COOKIE)) |
| 2190 | state->state = DHS_IPV4LL_BOUND; |
| 2191 | else |
| 2192 | state->state = DHS_BOUND; |
| 2193 | if (!state->lease.frominfo && |
| 2194 | !(ifo->options & (DHCPCD_INFORM | DHCPCD_STATIC))) |
| 2195 | if (write_lease(ifp, state->new) == -1) |
| 2196 | logger(ifp->ctx, LOG_ERR, |
| 2197 | "%s: write_lease: %m", __func__); |
| 2198 | |
| 2199 | applyaddr: |
| 2200 | ipv4_applyaddr(ifp); |
| 2201 | if (ifo->options & DHCPCD_ARP && |
| 2202 | !(ifp->ctx->options & DHCPCD_FORKED)) |
| 2203 | { |
| 2204 | #ifdef IN_IFF_TENTATIVE |
| 2205 | if (astate) |
| 2206 | arp_free_but(astate); |
| 2207 | else if (!ipv4ll) |
| 2208 | arp_close(ifp); |
| 2209 | #else |
| 2210 | if (state->added) { |
| 2211 | if (astate == NULL) { |
| 2212 | astate = arp_new(ifp, &state->addr); |
| 2213 | astate->announced_cb = |
| 2214 | dhcp_arp_announced; |
| 2215 | } |
| 2216 | if (astate) { |
| 2217 | arp_announce(astate); |
| 2218 | if (!ipv4ll) |
| 2219 | arp_free_but(astate); |
| 2220 | } |
| 2221 | } else if (!ipv4ll) |
| 2222 | arp_close(ifp); |
| 2223 | #endif |
| 2224 | } |
| 2225 | } |
| 2226 | |
| 2227 | static void |
| 2228 | dhcp_timeout(void *arg) |
| 2229 | { |
| 2230 | struct interface *ifp = arg; |
| 2231 | struct dhcp_state *state = D_STATE(ifp); |
| 2232 | |
| 2233 | dhcp_bind(ifp, NULL); |
| 2234 | state->interval = 0; |
| 2235 | dhcp_discover(ifp); |
| 2236 | } |
| 2237 | |
| 2238 | struct dhcp_message * |
| 2239 | dhcp_message_new(const struct in_addr *addr, const struct in_addr *mask) |
| 2240 | { |
| 2241 | struct dhcp_message *dhcp; |
| 2242 | uint8_t *p; |
| 2243 | |
| 2244 | dhcp = calloc(1, sizeof(*dhcp)); |
| 2245 | if (dhcp == NULL) |
| 2246 | return NULL; |
| 2247 | dhcp->yiaddr = addr->s_addr; |
| 2248 | p = dhcp->options; |
| 2249 | if (mask && mask->s_addr != INADDR_ANY) { |
| 2250 | *p++ = DHO_SUBNETMASK; |
| 2251 | *p++ = sizeof(mask->s_addr); |
| 2252 | memcpy(p, &mask->s_addr, sizeof(mask->s_addr)); |
| 2253 | p+= sizeof(mask->s_addr); |
| 2254 | } |
| 2255 | *p++ = DHO_END; |
| 2256 | return dhcp; |
| 2257 | } |
| 2258 | |
| 2259 | static void |
| 2260 | dhcp_static(struct interface *ifp) |
| 2261 | { |
| 2262 | struct if_options *ifo; |
| 2263 | struct dhcp_state *state; |
| 2264 | |
| 2265 | state = D_STATE(ifp); |
| 2266 | ifo = ifp->options; |
| 2267 | if (ifo->req_addr.s_addr == INADDR_ANY) { |
| 2268 | logger(ifp->ctx, LOG_INFO, |
| 2269 | "%s: waiting for 3rd party to " |
| 2270 | "configure IP address", |
| 2271 | ifp->name); |
| 2272 | state->reason = "3RDPARTY"; |
| 2273 | script_runreason(ifp, state->reason); |
| 2274 | return; |
| 2275 | } |
| 2276 | state->offer = dhcp_message_new(&ifo->req_addr, &ifo->req_mask); |
| 2277 | if (state->offer) { |
| 2278 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 2279 | dhcp_bind(ifp, NULL); |
| 2280 | } |
| 2281 | } |
| 2282 | |
| 2283 | void |
| 2284 | dhcp_inform(struct interface *ifp) |
| 2285 | { |
| 2286 | struct dhcp_state *state; |
| 2287 | struct if_options *ifo; |
| 2288 | struct ipv4_addr *ap; |
| 2289 | |
| 2290 | state = D_STATE(ifp); |
| 2291 | ifo = ifp->options; |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 2292 | logger(ifp->ctx, LOG_INFO, "%s: informing peers of local address", |
| 2293 | ifp->name); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2294 | if (ifp->ctx->options & DHCPCD_TEST) { |
| 2295 | state->addr.s_addr = ifo->req_addr.s_addr; |
| 2296 | state->net.s_addr = ifo->req_mask.s_addr; |
| 2297 | } else { |
| 2298 | if (ifo->req_addr.s_addr == INADDR_ANY) { |
| 2299 | state = D_STATE(ifp); |
| 2300 | ap = ipv4_iffindaddr(ifp, NULL, NULL); |
| 2301 | if (ap == NULL) { |
| 2302 | logger(ifp->ctx, LOG_INFO, |
| 2303 | "%s: waiting for 3rd party to " |
| 2304 | "configure IP address", |
| 2305 | ifp->name); |
| 2306 | state->reason = "3RDPARTY"; |
| 2307 | script_runreason(ifp, state->reason); |
| 2308 | return; |
| 2309 | } |
| 2310 | state->offer = |
| 2311 | dhcp_message_new(&ap->addr, &ap->net); |
| 2312 | } else |
| 2313 | state->offer = |
| 2314 | dhcp_message_new(&ifo->req_addr, &ifo->req_mask); |
| 2315 | if (state->offer) { |
| 2316 | ifo->options |= DHCPCD_STATIC; |
| 2317 | dhcp_bind(ifp, NULL); |
| 2318 | ifo->options &= ~DHCPCD_STATIC; |
| 2319 | } |
| 2320 | } |
| 2321 | |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 2322 | rpc_signal_status("Inform"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2323 | state->state = DHS_INFORM; |
| 2324 | state->xid = dhcp_xid(ifp); |
| 2325 | send_inform(ifp); |
| 2326 | } |
| 2327 | |
| 2328 | void |
| 2329 | dhcp_reboot_newopts(struct interface *ifp, unsigned long long oldopts) |
| 2330 | { |
| 2331 | struct if_options *ifo; |
| 2332 | struct dhcp_state *state = D_STATE(ifp); |
| 2333 | |
| 2334 | if (state == NULL) |
| 2335 | return; |
| 2336 | ifo = ifp->options; |
| 2337 | if ((ifo->options & (DHCPCD_INFORM | DHCPCD_STATIC) && |
| 2338 | state->addr.s_addr != ifo->req_addr.s_addr) || |
| 2339 | (oldopts & (DHCPCD_INFORM | DHCPCD_STATIC) && |
| 2340 | !(ifo->options & (DHCPCD_INFORM | DHCPCD_STATIC)))) |
| 2341 | { |
| 2342 | dhcp_drop(ifp, "EXPIRE"); |
| 2343 | } |
| 2344 | } |
| 2345 | |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2346 | static void start_unicast_arp(struct interface *ifp); |
| 2347 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2348 | static void |
| 2349 | dhcp_reboot(struct interface *ifp) |
| 2350 | { |
| 2351 | struct if_options *ifo; |
| 2352 | struct dhcp_state *state = D_STATE(ifp); |
| 2353 | |
| 2354 | if (state == NULL) |
| 2355 | return; |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 2356 | rpc_signal_status("Reboot"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2357 | ifo = ifp->options; |
| 2358 | state->state = DHS_REBOOT; |
| 2359 | state->interval = 0; |
| 2360 | |
| 2361 | if (ifo->options & DHCPCD_LINK && ifp->carrier == LINK_DOWN) { |
| 2362 | logger(ifp->ctx, LOG_INFO, |
| 2363 | "%s: waiting for carrier", ifp->name); |
| 2364 | return; |
| 2365 | } |
| 2366 | if (ifo->options & DHCPCD_STATIC) { |
| 2367 | dhcp_static(ifp); |
| 2368 | return; |
| 2369 | } |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2370 | if (ifo->options & DHCPCD_UNICAST_ARP) { |
| 2371 | start_unicast_arp(ifp); |
| 2372 | } |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2373 | if (ifo->options & DHCPCD_INFORM) { |
| 2374 | logger(ifp->ctx, LOG_INFO, "%s: informing address of %s", |
| 2375 | ifp->name, inet_ntoa(state->lease.addr)); |
| 2376 | dhcp_inform(ifp); |
| 2377 | return; |
| 2378 | } |
| 2379 | if (ifo->reboot == 0 || state->offer == NULL) { |
| 2380 | dhcp_discover(ifp); |
| 2381 | return; |
| 2382 | } |
| 2383 | if (state->offer->cookie == 0) |
| 2384 | return; |
| 2385 | |
| 2386 | logger(ifp->ctx, LOG_INFO, "%s: rebinding lease of %s", |
| 2387 | ifp->name, inet_ntoa(state->lease.addr)); |
| 2388 | state->xid = dhcp_xid(ifp); |
| 2389 | state->lease.server.s_addr = 0; |
| 2390 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 2391 | |
| 2392 | /* Need to add this before dhcp_expire and friends. */ |
| 2393 | if (!ifo->fallback && ifo->options & DHCPCD_IPV4LL && |
| 2394 | !IN_LINKLOCAL(htonl(state->addr.s_addr))) |
| 2395 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2396 | ifo->reboot, ipv4ll_start, ifp); |
| 2397 | |
| 2398 | if (ifo->options & DHCPCD_LASTLEASE && state->lease.frominfo) |
| 2399 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2400 | ifo->reboot, dhcp_timeout, ifp); |
| 2401 | else if (!(ifo->options & DHCPCD_INFORM)) |
| 2402 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2403 | ifo->reboot, dhcp_expire, ifp); |
| 2404 | |
| 2405 | /* Don't bother ARP checking as the server could NAK us first. |
| 2406 | * Don't call dhcp_request as that would change the state */ |
| 2407 | send_request(ifp); |
| 2408 | } |
| 2409 | |
| 2410 | void |
| 2411 | dhcp_drop(struct interface *ifp, const char *reason) |
| 2412 | { |
| 2413 | struct dhcp_state *state; |
| 2414 | #ifdef RELEASE_SLOW |
| 2415 | struct timespec ts; |
| 2416 | #endif |
| 2417 | |
| 2418 | state = D_STATE(ifp); |
| 2419 | /* dhcp_start may just have been called and we don't yet have a state |
| 2420 | * but we do have a timeout, so punt it. */ |
| 2421 | if (state == NULL) { |
| 2422 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 2423 | return; |
| 2424 | } |
| 2425 | /* Don't reset DHCP state if we have an IPv4LL address and link is up, |
| 2426 | * unless the interface is departing. */ |
| 2427 | if (state->state != DHS_IPV4LL_BOUND || |
| 2428 | ifp->carrier != LINK_UP || |
| 2429 | ifp->options->options & DHCPCD_DEPARTED) |
| 2430 | { |
| 2431 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 2432 | dhcp_auth_reset(&state->auth); |
| 2433 | dhcp_close(ifp); |
| 2434 | } |
| 2435 | |
Samuel Tan | e942e09 | 2015-08-13 17:14:37 -0700 | [diff] [blame] | 2436 | if (ifp->options->options & DHCPCD_RELEASE || |
| 2437 | strcmp(reason, "RELEASE") == 0) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2438 | unlink(state->leasefile); |
| 2439 | if (ifp->carrier != LINK_DOWN && |
| 2440 | state->new != NULL && |
| 2441 | state->new->cookie == htonl(MAGIC_COOKIE)) |
| 2442 | { |
| 2443 | logger(ifp->ctx, LOG_INFO, "%s: releasing lease of %s", |
| 2444 | ifp->name, inet_ntoa(state->lease.addr)); |
| 2445 | state->xid = dhcp_xid(ifp); |
| 2446 | send_message(ifp, DHCP_RELEASE, NULL); |
| 2447 | #ifdef RELEASE_SLOW |
| 2448 | /* Give the packet a chance to go */ |
| 2449 | ts.tv_sec = RELEASE_DELAY_S; |
| 2450 | ts.tv_nsec = RELEASE_DELAY_NS; |
| 2451 | nanosleep(&ts, NULL); |
| 2452 | #endif |
| 2453 | } |
| 2454 | } |
| 2455 | |
| 2456 | free(state->old); |
| 2457 | state->old = state->new; |
| 2458 | state->new = NULL; |
| 2459 | state->reason = reason; |
| 2460 | ipv4_applyaddr(ifp); |
| 2461 | free(state->old); |
| 2462 | state->old = NULL; |
| 2463 | state->lease.addr.s_addr = 0; |
| 2464 | ifp->options->options &= ~(DHCPCD_CSR_WARNED | |
| 2465 | DHCPCD_ROUTER_HOST_ROUTE_WARNED); |
| 2466 | } |
| 2467 | |
| 2468 | static void |
| 2469 | log_dhcp1(int lvl, const char *msg, |
| 2470 | const struct interface *ifp, const struct dhcp_message *dhcp, |
| 2471 | const struct in_addr *from, int ad) |
| 2472 | { |
| 2473 | const char *tfrom; |
| 2474 | char *a, sname[sizeof(dhcp->servername) * 4]; |
| 2475 | struct in_addr addr; |
| 2476 | int r; |
| 2477 | |
| 2478 | if (strcmp(msg, "NAK:") == 0) { |
| 2479 | a = get_option_string(ifp->ctx, dhcp, DHO_MESSAGE); |
| 2480 | if (a) { |
| 2481 | char *tmp; |
| 2482 | size_t al, tmpl; |
| 2483 | |
| 2484 | al = strlen(a); |
| 2485 | tmpl = (al * 4) + 1; |
| 2486 | tmp = malloc(tmpl); |
| 2487 | if (tmp == NULL) { |
| 2488 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 2489 | free(a); |
| 2490 | return; |
| 2491 | } |
| 2492 | print_string(tmp, tmpl, STRING, (uint8_t *)a, al); |
| 2493 | free(a); |
| 2494 | a = tmp; |
| 2495 | } |
| 2496 | } else if (ad && dhcp->yiaddr != 0) { |
| 2497 | addr.s_addr = dhcp->yiaddr; |
| 2498 | a = strdup(inet_ntoa(addr)); |
| 2499 | if (a == NULL) { |
| 2500 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 2501 | return; |
| 2502 | } |
| 2503 | } else |
| 2504 | a = NULL; |
| 2505 | |
| 2506 | tfrom = "from"; |
| 2507 | r = get_option_addr(ifp->ctx, &addr, dhcp, DHO_SERVERID); |
| 2508 | if (dhcp->servername[0] && r == 0) { |
| 2509 | print_string(sname, sizeof(sname), STRING, |
| 2510 | dhcp->servername, strlen((const char *)dhcp->servername)); |
| 2511 | if (a == NULL) |
| 2512 | logger(ifp->ctx, lvl, "%s: %s %s %s `%s'", |
| 2513 | ifp->name, msg, tfrom, inet_ntoa(addr), sname); |
| 2514 | else |
| 2515 | logger(ifp->ctx, lvl, "%s: %s %s %s %s `%s'", |
| 2516 | ifp->name, msg, a, tfrom, inet_ntoa(addr), sname); |
| 2517 | } else { |
| 2518 | if (r != 0) { |
| 2519 | tfrom = "via"; |
| 2520 | addr = *from; |
| 2521 | } |
| 2522 | if (a == NULL) |
| 2523 | logger(ifp->ctx, lvl, "%s: %s %s %s", |
| 2524 | ifp->name, msg, tfrom, inet_ntoa(addr)); |
| 2525 | else |
| 2526 | logger(ifp->ctx, lvl, "%s: %s %s %s %s", |
| 2527 | ifp->name, msg, a, tfrom, inet_ntoa(addr)); |
| 2528 | } |
| 2529 | free(a); |
| 2530 | } |
| 2531 | |
| 2532 | static void |
| 2533 | log_dhcp(int lvl, const char *msg, |
| 2534 | const struct interface *ifp, const struct dhcp_message *dhcp, |
| 2535 | const struct in_addr *from) |
| 2536 | { |
| 2537 | |
| 2538 | log_dhcp1(lvl, msg, ifp, dhcp, from, 1); |
| 2539 | } |
| 2540 | |
| 2541 | static int |
| 2542 | blacklisted_ip(const struct if_options *ifo, in_addr_t addr) |
| 2543 | { |
| 2544 | size_t i; |
| 2545 | |
| 2546 | for (i = 0; i < ifo->blacklist_len; i += 2) |
| 2547 | if (ifo->blacklist[i] == (addr & ifo->blacklist[i + 1])) |
| 2548 | return 1; |
| 2549 | return 0; |
| 2550 | } |
| 2551 | |
| 2552 | static int |
| 2553 | whitelisted_ip(const struct if_options *ifo, in_addr_t addr) |
| 2554 | { |
| 2555 | size_t i; |
| 2556 | |
| 2557 | if (ifo->whitelist_len == 0) |
| 2558 | return -1; |
| 2559 | for (i = 0; i < ifo->whitelist_len; i += 2) |
| 2560 | if (ifo->whitelist[i] == (addr & ifo->whitelist[i + 1])) |
| 2561 | return 1; |
| 2562 | return 0; |
| 2563 | } |
| 2564 | |
| 2565 | static void |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2566 | save_gateway_addr(struct interface *ifp, const uint8_t *gw_hwaddr) |
| 2567 | { |
| 2568 | struct dhcp_state *state = D_STATE(ifp); |
| 2569 | memcpy(state->server_info.gw_hwaddr, gw_hwaddr, ifp->hwlen); |
| 2570 | state->server_info.gw_hwlen = ifp->hwlen; |
| 2571 | } |
| 2572 | |
| 2573 | static void |
| 2574 | dhcp_probe_gw_timeout(struct arp_state *astate) |
| 2575 | { |
Samuel Tan | 1c4088e | 2015-08-13 16:18:58 -0700 | [diff] [blame] | 2576 | struct dhcp_state *state = D_STATE(astate->iface); |
| 2577 | |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2578 | /* Ignore unicast ARP failures. */ |
| 2579 | if (astate->dest_hwlen) |
| 2580 | return; |
| 2581 | |
| 2582 | /* Probegw failure, allow ourselves to fail only once this way */ |
Samuel Tan | 1c4088e | 2015-08-13 16:18:58 -0700 | [diff] [blame] | 2583 | logger(astate->iface->ctx, LOG_ERR, |
| 2584 | "%s: Probe gateway %s timed out ", |
| 2585 | astate->iface->name, inet_ntoa(astate->addr)); |
| 2586 | astate->iface->options->options &= ~DHCPCD_ARPGW; |
| 2587 | |
| 2588 | unlink(state->leasefile); |
| 2589 | if (!state->lease.frominfo) |
| 2590 | dhcp_decline(astate->iface); |
| 2591 | #ifdef IN_IFF_DUPLICATED |
| 2592 | ia = ipv4_iffindaddr(astate->iface, &astate->addr, NULL); |
| 2593 | if (ia) |
| 2594 | ipv4_deladdr(astate->iface, &ia->addr, &ia->net); |
| 2595 | #endif |
| 2596 | eloop_timeout_delete(astate->iface->ctx->eloop, NULL, |
| 2597 | astate->iface); |
| 2598 | eloop_timeout_add_sec(astate->iface->ctx->eloop, |
| 2599 | DHCP_RAND_MAX, dhcp_discover, astate->iface); |
| 2600 | } |
| 2601 | |
| 2602 | static void |
| 2603 | dhcp_probe_gw_response(struct arp_state *astate, const struct arp_msg *amsg) |
| 2604 | { |
| 2605 | /* Verify this is a response for the gateway probe. */ |
| 2606 | if (astate->src_addr.s_addr != 0 && |
| 2607 | amsg && |
| 2608 | amsg->tip.s_addr == astate->src_addr.s_addr && |
| 2609 | amsg->sip.s_addr == astate->addr.s_addr) { |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2610 | if (astate->dest_hwlen) { |
| 2611 | /* Response to unicast ARP. */ |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 2612 | rpc_notify_unicast_arp(astate->iface); |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2613 | } else { |
| 2614 | /* Response to arpgw request. */ |
| 2615 | save_gateway_addr(astate->iface, amsg->sha); |
| 2616 | |
| 2617 | dhcp_close(astate->iface); |
| 2618 | eloop_timeout_delete(astate->iface->ctx->eloop, |
| 2619 | NULL, astate->iface); |
| 2620 | #ifdef IN_IFF_TENTATIVE |
| 2621 | ipv4_finaliseaddr(astate->iface); |
| 2622 | #else |
| 2623 | dhcp_bind(astate->iface, NULL); |
| 2624 | #endif |
| 2625 | } |
Samuel Tan | 1c4088e | 2015-08-13 16:18:58 -0700 | [diff] [blame] | 2626 | arp_close(astate->iface); |
| 2627 | } |
| 2628 | } |
| 2629 | |
| 2630 | static int |
| 2631 | dhcp_probe_gw(struct interface *ifp) |
| 2632 | { |
| 2633 | struct dhcp_state *state = D_STATE(ifp); |
| 2634 | struct arp_state *astate; |
| 2635 | struct in_addr gateway_addr; |
| 2636 | |
| 2637 | if (get_option_addr(ifp->ctx, &gateway_addr, |
| 2638 | state->offer, DHO_ROUTER) == 0) { |
| 2639 | astate = arp_new(ifp, &gateway_addr); |
| 2640 | if (astate) { |
| 2641 | astate->src_addr.s_addr = state->offer->yiaddr; |
| 2642 | astate->probed_cb = dhcp_probe_gw_timeout; |
| 2643 | astate->conflicted_cb = dhcp_probe_gw_response; |
| 2644 | arp_probe(astate); |
| 2645 | return 1; |
| 2646 | } |
| 2647 | } |
| 2648 | return 0; |
| 2649 | } |
| 2650 | |
| 2651 | static void |
Samuel Tan | f20514b | 2015-08-13 16:24:02 -0700 | [diff] [blame] | 2652 | start_unicast_arp(struct interface *ifp) |
| 2653 | { |
| 2654 | struct dhcp_state *state = D_STATE(ifp); |
| 2655 | struct in_addr gwa; |
| 2656 | struct in_addr src_addr; |
| 2657 | struct arp_state *astate; |
| 2658 | |
| 2659 | if (!state->offer) |
| 2660 | return; |
| 2661 | |
| 2662 | if (!state->lease.frominfo) |
| 2663 | return; |
| 2664 | |
| 2665 | if (state->server_info.gw_hwlen != ifp->hwlen) |
| 2666 | return; |
| 2667 | |
| 2668 | if (get_option_addr(ifp->ctx, &gwa, state->offer, DHO_ROUTER)) |
| 2669 | return; |
| 2670 | |
| 2671 | astate = arp_new(ifp, &gwa); |
| 2672 | if (!astate) |
| 2673 | return; |
| 2674 | if (state->offer->yiaddr) |
| 2675 | astate->src_addr.s_addr = state->offer->yiaddr; |
| 2676 | else |
| 2677 | astate->src_addr.s_addr = state->offer->ciaddr; |
| 2678 | astate->probed_cb = dhcp_probe_gw_timeout; |
| 2679 | astate->conflicted_cb = dhcp_probe_gw_response; |
| 2680 | astate->dest_hwlen = state->server_info.gw_hwlen; |
| 2681 | memcpy(astate->dest_hwaddr, state->server_info.gw_hwaddr, |
| 2682 | state->server_info.gw_hwlen); |
| 2683 | |
| 2684 | arp_probe(astate); |
| 2685 | |
| 2686 | /* Invalidate our gateway address until the next successful PROBEGW. */ |
| 2687 | state->server_info.gw_hwlen = 0; |
| 2688 | } |
| 2689 | |
| 2690 | static void |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2691 | dhcp_arp_probed(struct arp_state *astate) |
| 2692 | { |
| 2693 | struct dhcp_state *state; |
| 2694 | struct if_options *ifo; |
| 2695 | |
| 2696 | /* We didn't find a profile for this |
| 2697 | * address or hwaddr, so move to the next |
| 2698 | * arping profile */ |
| 2699 | state = D_STATE(astate->iface); |
| 2700 | ifo = astate->iface->options; |
| 2701 | if (state->arping_index < ifo->arping_len) { |
| 2702 | if (++state->arping_index < ifo->arping_len) { |
| 2703 | astate->addr.s_addr = |
| 2704 | ifo->arping[state->arping_index - 1]; |
| 2705 | arp_probe(astate); |
| 2706 | } |
| 2707 | dhcpcd_startinterface(astate->iface); |
| 2708 | return; |
| 2709 | } |
Samuel Tan | 1c4088e | 2015-08-13 16:18:58 -0700 | [diff] [blame] | 2710 | |
| 2711 | /* Probe the gateway specified in the lease offer. */ |
| 2712 | if ((ifo->options & DHCPCD_ARPGW) && (dhcp_probe_gw(astate->iface))) { |
| 2713 | return; |
| 2714 | } |
| 2715 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2716 | dhcp_close(astate->iface); |
| 2717 | eloop_timeout_delete(astate->iface->ctx->eloop, NULL, astate->iface); |
| 2718 | #ifdef IN_IFF_TENTATIVE |
| 2719 | ipv4_finaliseaddr(astate->iface); |
| 2720 | arp_close(astate->iface); |
| 2721 | #else |
| 2722 | dhcp_bind(astate->iface, astate); |
| 2723 | #endif |
| 2724 | } |
| 2725 | |
| 2726 | static void |
| 2727 | dhcp_arp_conflicted(struct arp_state *astate, const struct arp_msg *amsg) |
| 2728 | { |
| 2729 | struct dhcp_state *state; |
| 2730 | struct if_options *ifo; |
| 2731 | |
| 2732 | state = D_STATE(astate->iface); |
| 2733 | ifo = astate->iface->options; |
| 2734 | if (state->arping_index && |
| 2735 | state->arping_index <= ifo->arping_len && |
| 2736 | amsg && |
| 2737 | (amsg->sip.s_addr == ifo->arping[state->arping_index - 1] || |
| 2738 | (amsg->sip.s_addr == 0 && |
| 2739 | amsg->tip.s_addr == ifo->arping[state->arping_index - 1]))) |
| 2740 | { |
| 2741 | char buf[HWADDR_LEN * 3]; |
| 2742 | |
| 2743 | astate->failed.s_addr = ifo->arping[state->arping_index - 1]; |
| 2744 | arp_report_conflicted(astate, amsg); |
| 2745 | hwaddr_ntoa(amsg->sha, astate->iface->hwlen, buf, sizeof(buf)); |
| 2746 | if (dhcpcd_selectprofile(astate->iface, buf) == -1 && |
| 2747 | dhcpcd_selectprofile(astate->iface, |
| 2748 | inet_ntoa(astate->failed)) == -1) |
| 2749 | { |
| 2750 | /* We didn't find a profile for this |
| 2751 | * address or hwaddr, so move to the next |
| 2752 | * arping profile */ |
| 2753 | dhcp_arp_probed(astate); |
| 2754 | return; |
| 2755 | } |
| 2756 | dhcp_close(astate->iface); |
| 2757 | arp_close(astate->iface); |
| 2758 | eloop_timeout_delete(astate->iface->ctx->eloop, NULL, |
| 2759 | astate->iface); |
| 2760 | dhcpcd_startinterface(astate->iface); |
| 2761 | } |
| 2762 | |
| 2763 | /* RFC 2131 3.1.5, Client-server interaction |
| 2764 | * NULL amsg means IN_IFF_DUPLICATED */ |
| 2765 | if (amsg == NULL || (state->offer && |
| 2766 | (amsg->sip.s_addr == state->offer->yiaddr || |
| 2767 | (amsg->sip.s_addr == 0 && |
| 2768 | amsg->tip.s_addr == state->offer->yiaddr)))) |
| 2769 | { |
| 2770 | #ifdef IN_IFF_DUPLICATED |
| 2771 | struct ipv4_addr *ia; |
| 2772 | #endif |
| 2773 | |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 2774 | if (amsg) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2775 | astate->failed.s_addr = state->offer->yiaddr; |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 2776 | state->failed.s_addr = state->offer->yiaddr; |
| 2777 | } else { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2778 | astate->failed = astate->addr; |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 2779 | state->failed = astate->addr; |
| 2780 | } |
| 2781 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2782 | arp_report_conflicted(astate, amsg); |
| 2783 | unlink(state->leasefile); |
| 2784 | if (!state->lease.frominfo) |
| 2785 | dhcp_decline(astate->iface); |
| 2786 | #ifdef IN_IFF_DUPLICATED |
| 2787 | ia = ipv4_iffindaddr(astate->iface, &astate->addr, NULL); |
| 2788 | if (ia) |
| 2789 | ipv4_deladdr(astate->iface, &ia->addr, &ia->net); |
| 2790 | #endif |
Samuel Tan | 11464a5 | 2015-08-13 16:48:29 -0700 | [diff] [blame] | 2791 | arp_close(astate->iface); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2792 | eloop_timeout_delete(astate->iface->ctx->eloop, NULL, |
| 2793 | astate->iface); |
| 2794 | eloop_timeout_add_sec(astate->iface->ctx->eloop, |
| 2795 | DHCP_RAND_MAX, dhcp_discover, astate->iface); |
| 2796 | } |
| 2797 | } |
| 2798 | |
| 2799 | static void |
Samuel Tan | b2d21e6 | 2015-08-13 16:45:06 -0700 | [diff] [blame] | 2800 | handle_nak(void *arg) |
| 2801 | { |
| 2802 | struct interface *ifp = arg; |
| 2803 | struct dhcp_state *state = D_STATE(ifp); |
| 2804 | |
| 2805 | logger(ifp->ctx, LOG_INFO, "%s: Handling deferred NAK", ifp->name); |
| 2806 | if (!(ifp->ctx->options & DHCPCD_TEST)) { |
| 2807 | dhcp_drop(ifp, "NAK"); |
| 2808 | unlink(state->leasefile); |
| 2809 | } |
| 2810 | |
| 2811 | /* If we constantly get NAKS then we should slowly back off */ |
| 2812 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2813 | state->nakoff, dhcp_discover, ifp); |
| 2814 | if (state->nakoff == 0) |
| 2815 | state->nakoff = 1; |
| 2816 | else { |
| 2817 | state->nakoff *= 2; |
| 2818 | if (state->nakoff > NAKOFF_MAX) |
| 2819 | state->nakoff = NAKOFF_MAX; |
| 2820 | } |
| 2821 | } |
| 2822 | |
| 2823 | static void |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2824 | dhcp_handledhcp(struct interface *ifp, struct dhcp_message **dhcpp, |
| 2825 | const struct in_addr *from) |
| 2826 | { |
| 2827 | struct dhcp_state *state = D_STATE(ifp); |
| 2828 | struct if_options *ifo = ifp->options; |
| 2829 | struct dhcp_message *dhcp = *dhcpp; |
| 2830 | struct dhcp_lease *lease = &state->lease; |
| 2831 | uint8_t type, tmp; |
| 2832 | const uint8_t *auth; |
| 2833 | struct in_addr addr; |
| 2834 | unsigned int i; |
| 2835 | size_t auth_len; |
| 2836 | char *msg; |
| 2837 | struct arp_state *astate; |
| 2838 | struct ipv4_addr *ia; |
| 2839 | |
| 2840 | /* We may have found a BOOTP server */ |
| 2841 | if (get_option_uint8(ifp->ctx, &type, dhcp, DHO_MESSAGETYPE) == -1) |
| 2842 | type = 0; |
| 2843 | else if (ifo->options & DHCPCD_BOOTP) { |
| 2844 | logger(ifp->ctx, LOG_DEBUG, |
| 2845 | "%s: ignoring DHCP reply (excpecting BOOTP)", |
| 2846 | ifp->name); |
| 2847 | return; |
| 2848 | } |
| 2849 | |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 2850 | logger(ifp->ctx, LOG_INFO, "%s: received %s with xid 0x%x", |
| 2851 | ifp->name, get_dhcp_op(type), state->xid); |
| 2852 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2853 | /* Authenticate the message */ |
| 2854 | auth = get_option(ifp->ctx, dhcp, DHO_AUTHENTICATION, &auth_len); |
| 2855 | if (auth) { |
| 2856 | if (dhcp_auth_validate(&state->auth, &ifo->auth, |
| 2857 | (uint8_t *)*dhcpp, sizeof(**dhcpp), 4, type, |
| 2858 | auth, auth_len) == NULL) |
| 2859 | { |
| 2860 | logger(ifp->ctx, LOG_DEBUG, |
| 2861 | "%s: dhcp_auth_validate: %m", ifp->name); |
| 2862 | log_dhcp1(LOG_ERR, "authentication failed", |
| 2863 | ifp, dhcp, from, 0); |
| 2864 | return; |
| 2865 | } |
| 2866 | if (state->auth.token) |
| 2867 | logger(ifp->ctx, LOG_DEBUG, |
| 2868 | "%s: validated using 0x%08" PRIu32, |
| 2869 | ifp->name, state->auth.token->secretid); |
| 2870 | else |
| 2871 | logger(ifp->ctx, LOG_DEBUG, |
| 2872 | "%s: accepted reconfigure key", ifp->name); |
| 2873 | } else if (ifo->auth.options & DHCPCD_AUTH_REQUIRE) { |
| 2874 | log_dhcp1(LOG_ERR, "no authentication", ifp, dhcp, from, 0); |
| 2875 | return; |
| 2876 | } else if (ifo->auth.options & DHCPCD_AUTH_SEND) |
| 2877 | log_dhcp1(LOG_WARNING, "no authentication", |
| 2878 | ifp, dhcp, from, 0); |
| 2879 | |
| 2880 | /* RFC 3203 */ |
| 2881 | if (type == DHCP_FORCERENEW) { |
| 2882 | if (from->s_addr == INADDR_ANY || |
| 2883 | from->s_addr == INADDR_BROADCAST) |
| 2884 | { |
| 2885 | log_dhcp(LOG_ERR, "discarding Force Renew", |
| 2886 | ifp, dhcp, from); |
| 2887 | return; |
| 2888 | } |
| 2889 | if (auth == NULL) { |
| 2890 | log_dhcp(LOG_ERR, "unauthenticated Force Renew", |
| 2891 | ifp, dhcp, from); |
| 2892 | return; |
| 2893 | } |
| 2894 | if (state->state != DHS_BOUND && state->state != DHS_INFORM) { |
| 2895 | log_dhcp(LOG_DEBUG, "not bound, ignoring Force Renew", |
| 2896 | ifp, dhcp, from); |
| 2897 | return; |
| 2898 | } |
| 2899 | log_dhcp(LOG_ERR, "Force Renew from", ifp, dhcp, from); |
| 2900 | /* The rebind and expire timings are still the same, we just |
| 2901 | * enter the renew state early */ |
| 2902 | if (state->state == DHS_BOUND) { |
| 2903 | eloop_timeout_delete(ifp->ctx->eloop, |
| 2904 | dhcp_renew, ifp); |
| 2905 | dhcp_renew(ifp); |
| 2906 | } else { |
| 2907 | eloop_timeout_delete(ifp->ctx->eloop, |
| 2908 | send_inform, ifp); |
| 2909 | dhcp_inform(ifp); |
| 2910 | } |
| 2911 | return; |
| 2912 | } |
| 2913 | |
| 2914 | if (state->state == DHS_BOUND) { |
| 2915 | /* Before we supported FORCERENEW we closed off the raw |
| 2916 | * port so we effectively ignored all messages. |
| 2917 | * As such we'll not log by default here. */ |
| 2918 | //log_dhcp(LOG_DEBUG, "bound, ignoring", iface, dhcp, from); |
| 2919 | return; |
| 2920 | } |
| 2921 | |
| 2922 | /* Ensure it's the right transaction */ |
| 2923 | if (state->xid != ntohl(dhcp->xid)) { |
| 2924 | logger(ifp->ctx, LOG_DEBUG, |
| 2925 | "%s: wrong xid 0x%x (expecting 0x%x) from %s", |
| 2926 | ifp->name, ntohl(dhcp->xid), state->xid, |
| 2927 | inet_ntoa(*from)); |
| 2928 | return; |
| 2929 | } |
| 2930 | /* reset the message counter */ |
| 2931 | state->interval = 0; |
| 2932 | |
| 2933 | /* Ensure that no reject options are present */ |
| 2934 | for (i = 1; i < 255; i++) { |
| 2935 | if (has_option_mask(ifo->rejectmask, i) && |
| 2936 | get_option_uint8(ifp->ctx, &tmp, dhcp, (uint8_t)i) == 0) |
| 2937 | { |
| 2938 | log_dhcp(LOG_WARNING, "reject DHCP", ifp, dhcp, from); |
| 2939 | return; |
| 2940 | } |
| 2941 | } |
| 2942 | |
| 2943 | if (type == DHCP_NAK) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2944 | if ((msg = get_option_string(ifp->ctx, dhcp, DHO_MESSAGE))) { |
| 2945 | logger(ifp->ctx, LOG_WARNING, "%s: message: %s", |
| 2946 | ifp->name, msg); |
| 2947 | free(msg); |
| 2948 | } |
| 2949 | if (state->state == DHS_INFORM) /* INFORM should not be NAKed */ |
| 2950 | return; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2951 | |
Samuel Tan | b2d21e6 | 2015-08-13 16:45:06 -0700 | [diff] [blame] | 2952 | log_dhcp(LOG_WARNING, "NAK (deferred):", ifp, dhcp, from); |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 2953 | rpc_signal_status("NakDefer"); |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 2954 | if (state->nak_receive_count == 0) |
| 2955 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 2956 | DHCP_BASE, handle_nak, ifp); |
| 2957 | state->nak_receive_count++; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 2958 | return; |
| 2959 | } |
| 2960 | |
| 2961 | /* Ensure that all required options are present */ |
| 2962 | for (i = 1; i < 255; i++) { |
| 2963 | if (has_option_mask(ifo->requiremask, i) && |
| 2964 | get_option_uint8(ifp->ctx, &tmp, dhcp, (uint8_t)i) != 0) |
| 2965 | { |
| 2966 | /* If we are BOOTP, then ignore the need for serverid. |
| 2967 | * To ignore BOOTP, require dhcp_message_type. |
| 2968 | * However, nothing really stops BOOTP from providing |
| 2969 | * DHCP style options as well so the above isn't |
| 2970 | * always true. */ |
| 2971 | if (type == 0 && i == DHO_SERVERID) |
| 2972 | continue; |
| 2973 | log_dhcp(LOG_WARNING, "reject DHCP", ifp, dhcp, from); |
| 2974 | return; |
| 2975 | } |
| 2976 | } |
| 2977 | |
| 2978 | /* DHCP Auto-Configure, RFC 2563 */ |
| 2979 | if (type == DHCP_OFFER && dhcp->yiaddr == 0) { |
| 2980 | log_dhcp(LOG_WARNING, "no address given", ifp, dhcp, from); |
| 2981 | if ((msg = get_option_string(ifp->ctx, dhcp, DHO_MESSAGE))) { |
| 2982 | logger(ifp->ctx, LOG_WARNING, |
| 2983 | "%s: message: %s", ifp->name, msg); |
| 2984 | free(msg); |
| 2985 | } |
| 2986 | if ((state->state == DHS_DISCOVER || |
| 2987 | state->state == DHS_IPV4LL_BOUND) && |
| 2988 | get_option_uint8(ifp->ctx, &tmp, dhcp, |
| 2989 | DHO_AUTOCONFIGURE) == 0) |
| 2990 | { |
| 2991 | switch (tmp) { |
| 2992 | case 0: |
| 2993 | log_dhcp(LOG_WARNING, "IPv4LL disabled from", |
| 2994 | ifp, dhcp, from); |
| 2995 | dhcp_drop(ifp, "EXPIRE"); |
| 2996 | arp_close(ifp); |
| 2997 | eloop_timeout_delete(ifp->ctx->eloop, |
| 2998 | NULL, ifp); |
| 2999 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 3000 | DHCP_MAX, dhcp_discover, |
| 3001 | ifp); |
| 3002 | break; |
| 3003 | case 1: |
| 3004 | log_dhcp(LOG_WARNING, "IPv4LL enabled from", |
| 3005 | ifp, dhcp, from); |
| 3006 | eloop_timeout_delete(ifp->ctx->eloop, |
| 3007 | NULL, ifp); |
| 3008 | if (IN_LINKLOCAL(htonl(state->addr.s_addr))) |
| 3009 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 3010 | DHCP_MAX, dhcp_discover, ifp); |
| 3011 | else |
| 3012 | ipv4ll_start(ifp); |
| 3013 | break; |
| 3014 | default: |
| 3015 | logger(ifp->ctx, LOG_ERR, |
| 3016 | "%s: unknown auto configuration option %d", |
| 3017 | ifp->name, tmp); |
| 3018 | break; |
| 3019 | } |
| 3020 | } |
| 3021 | return; |
| 3022 | } |
| 3023 | |
| 3024 | /* Ensure that the address offered is valid */ |
| 3025 | if ((type == 0 || type == DHCP_OFFER || type == DHCP_ACK) && |
| 3026 | (dhcp->ciaddr == INADDR_ANY || dhcp->ciaddr == INADDR_BROADCAST) && |
| 3027 | (dhcp->yiaddr == INADDR_ANY || dhcp->yiaddr == INADDR_BROADCAST)) |
| 3028 | { |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 3029 | rpc_signal_status("IgnoreInvalidOffer"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3030 | log_dhcp(LOG_WARNING, "reject invalid address", |
| 3031 | ifp, dhcp, from); |
| 3032 | return; |
| 3033 | } |
| 3034 | |
| 3035 | #ifdef IN_IFF_DUPLICATED |
| 3036 | ia = ipv4_iffindaddr(ifp, &lease->addr, NULL); |
| 3037 | if (ia && ia->addr_flags & IN_IFF_DUPLICATED) { |
| 3038 | log_dhcp(LOG_WARNING, "declined duplicate address", |
| 3039 | ifp, dhcp, from); |
| 3040 | if (type) |
| 3041 | dhcp_decline(ifp); |
| 3042 | ipv4_deladdr(ifp, &ia->addr, &ia->net); |
| 3043 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 3044 | eloop_timeout_add_sec(ifp->ctx->eloop, |
| 3045 | DHCP_RAND_MAX, dhcp_discover, ifp); |
| 3046 | return; |
| 3047 | } |
| 3048 | #endif |
| 3049 | |
| 3050 | if ((type == 0 || type == DHCP_OFFER) && |
| 3051 | (state->state == DHS_DISCOVER || state->state == DHS_IPV4LL_BOUND)) |
| 3052 | { |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 3053 | if (dhcp->yiaddr == state->failed.s_addr && |
| 3054 | state->failed_address_offer_count == 0) { |
| 3055 | log_dhcp(LOG_WARNING, |
| 3056 | "reject previously declined address", |
| 3057 | ifp, dhcp, from); |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 3058 | rpc_signal_status("IgnoreFailedOffer"); |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 3059 | state->failed_address_offer_count++; |
| 3060 | return; |
| 3061 | } |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3062 | lease->frominfo = 0; |
| 3063 | lease->addr.s_addr = dhcp->yiaddr; |
| 3064 | lease->cookie = dhcp->cookie; |
| 3065 | if (type == 0 || |
| 3066 | get_option_addr(ifp->ctx, |
| 3067 | &lease->server, dhcp, DHO_SERVERID) != 0) |
| 3068 | lease->server.s_addr = INADDR_ANY; |
| 3069 | log_dhcp(LOG_INFO, "offered", ifp, dhcp, from); |
| 3070 | free(state->offer); |
| 3071 | state->offer = dhcp; |
| 3072 | *dhcpp = NULL; |
| 3073 | if (ifp->ctx->options & DHCPCD_TEST) { |
| 3074 | free(state->old); |
| 3075 | state->old = state->new; |
| 3076 | state->new = state->offer; |
| 3077 | state->offer = NULL; |
| 3078 | state->reason = "TEST"; |
| 3079 | script_runreason(ifp, state->reason); |
| 3080 | eloop_exit(ifp->ctx->eloop, EXIT_SUCCESS); |
| 3081 | return; |
| 3082 | } |
| 3083 | eloop_timeout_delete(ifp->ctx->eloop, send_discover, ifp); |
Samuel Tan | b2d21e6 | 2015-08-13 16:45:06 -0700 | [diff] [blame] | 3084 | eloop_timeout_delete(ifp->ctx->eloop, handle_nak, ifp); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3085 | /* We don't request BOOTP addresses */ |
| 3086 | if (type) { |
| 3087 | /* We used to ARP check here, but that seems to be in |
| 3088 | * violation of RFC2131 where it only describes |
| 3089 | * DECLINE after REQUEST. |
| 3090 | * It also seems that some MS DHCP servers actually |
| 3091 | * ignore DECLINE if no REQUEST, ie we decline a |
| 3092 | * DISCOVER. */ |
| 3093 | dhcp_request(ifp); |
| 3094 | return; |
| 3095 | } |
| 3096 | } |
| 3097 | |
| 3098 | if (type) { |
| 3099 | if (type == DHCP_OFFER) { |
| 3100 | log_dhcp(LOG_WARNING, "ignoring offer of", |
| 3101 | ifp, dhcp, from); |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 3102 | rpc_signal_status("IgnoreAdditionalOffer"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3103 | return; |
| 3104 | } |
| 3105 | |
| 3106 | /* We should only be dealing with acks */ |
| 3107 | if (type != DHCP_ACK) { |
| 3108 | log_dhcp(LOG_ERR, "not ACK or OFFER", |
| 3109 | ifp, dhcp, from); |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 3110 | rpc_signal_status("IgnoreNonOffer"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3111 | return; |
| 3112 | } |
| 3113 | |
| 3114 | if (!(ifo->options & DHCPCD_INFORM)) |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 3115 | log_dhcp(LOG_INFO, "acknowledged", ifp, dhcp, from); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3116 | else |
| 3117 | ifo->options &= ~DHCPCD_STATIC; |
| 3118 | } |
| 3119 | |
| 3120 | |
| 3121 | /* No NAK, so reset the backoff |
| 3122 | * We don't reset on an OFFER message because the server could |
| 3123 | * potentially NAK the REQUEST. */ |
| 3124 | state->nakoff = 0; |
| 3125 | |
| 3126 | /* BOOTP could have already assigned this above, so check we still |
| 3127 | * have a pointer. */ |
| 3128 | if (*dhcpp) { |
| 3129 | free(state->offer); |
| 3130 | state->offer = dhcp; |
| 3131 | *dhcpp = NULL; |
| 3132 | } |
| 3133 | |
| 3134 | lease->frominfo = 0; |
| 3135 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 3136 | astate = NULL; |
| 3137 | |
Samuel Tan | 47d708b | 2015-08-13 16:51:04 -0700 | [diff] [blame] | 3138 | #ifdef IN_IFF_TENTATIVE |
| 3139 | addr.s_addr = state->offer->yiaddr; |
| 3140 | astate = arp_new(ifp, &addr); |
| 3141 | if (astate) { |
| 3142 | astate->probed_cb = dhcp_arp_probed; |
| 3143 | astate->conflicted_cb = dhcp_arp_conflicted; |
| 3144 | /* No need to start the probe as we'll |
| 3145 | * listen to the kernel stating DAD or not and |
| 3146 | * that action look look for our ARP state for |
| 3147 | * what to do. */ |
| 3148 | } |
| 3149 | #else |
Samuel Tan | 5158c9d | 2015-08-13 18:09:30 -0700 | [diff] [blame] | 3150 | if ((ifo->options & DHCPCD_ARP || state->nak_receive_count > 0 || |
| 3151 | dhcp->yiaddr == state->failed.s_addr) |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3152 | && state->addr.s_addr != state->offer->yiaddr) |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3153 | { |
| 3154 | addr.s_addr = state->offer->yiaddr; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3155 | /* If the interface already has the address configured |
| 3156 | * then we can't ARP for duplicate detection. */ |
| 3157 | ia = ipv4_findaddr(ifp->ctx, &addr); |
Samuel Tan | 47d708b | 2015-08-13 16:51:04 -0700 | [diff] [blame] | 3158 | if (ia == NULL) { |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3159 | astate = arp_new(ifp, &addr); |
| 3160 | if (astate) { |
| 3161 | astate->probed_cb = dhcp_arp_probed; |
| 3162 | astate->conflicted_cb = dhcp_arp_conflicted; |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3163 | arp_probe(astate); |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 3164 | rpc_signal_status("ArpSelf"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3165 | } |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3166 | return; |
| 3167 | } |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3168 | } |
Samuel Tan | 47d708b | 2015-08-13 16:51:04 -0700 | [diff] [blame] | 3169 | #endif |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3170 | |
Samuel Tan | 1c4088e | 2015-08-13 16:18:58 -0700 | [diff] [blame] | 3171 | if ((ifo->options & DHCPCD_ARPGW) && (dhcp_probe_gw(ifp))) { |
Samuel Tan | 23ff6ed | 2015-08-13 16:50:06 -0700 | [diff] [blame] | 3172 | rpc_signal_status("ArpGateway"); |
Samuel Tan | 1c4088e | 2015-08-13 16:18:58 -0700 | [diff] [blame] | 3173 | return; |
| 3174 | } |
| 3175 | |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3176 | dhcp_bind(ifp, astate); |
| 3177 | } |
| 3178 | |
| 3179 | static size_t |
| 3180 | get_udp_data(const uint8_t **data, const uint8_t *udp) |
| 3181 | { |
| 3182 | struct udp_dhcp_packet p; |
| 3183 | |
| 3184 | memcpy(&p, udp, sizeof(p)); |
| 3185 | *data = udp + offsetof(struct udp_dhcp_packet, dhcp); |
| 3186 | return ntohs(p.ip.ip_len) - sizeof(p.ip) - sizeof(p.udp); |
| 3187 | } |
| 3188 | |
| 3189 | static int |
| 3190 | valid_udp_packet(const uint8_t *data, size_t data_len, struct in_addr *from, |
| 3191 | int noudpcsum) |
| 3192 | { |
| 3193 | struct udp_dhcp_packet p; |
| 3194 | uint16_t bytes, udpsum; |
| 3195 | |
| 3196 | if (data_len < sizeof(p.ip)) { |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 3197 | syslog(LOG_WARNING, "packet short than an ip header " |
| 3198 | "(len=%zd)", data_len); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3199 | if (from) |
| 3200 | from->s_addr = INADDR_ANY; |
| 3201 | errno = EINVAL; |
| 3202 | return -1; |
| 3203 | } |
| 3204 | memcpy(&p, data, MIN(data_len, sizeof(p))); |
| 3205 | if (from) |
| 3206 | from->s_addr = p.ip.ip_src.s_addr; |
| 3207 | if (data_len > sizeof(p)) { |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 3208 | syslog(LOG_WARNING, "packet too long (%zd bytes)", data_len); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3209 | errno = EINVAL; |
| 3210 | return -1; |
| 3211 | } |
| 3212 | if (checksum(&p.ip, sizeof(p.ip)) != 0) { |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 3213 | syslog(LOG_WARNING, "packet failed ip header checksum"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3214 | errno = EINVAL; |
| 3215 | return -1; |
| 3216 | } |
| 3217 | |
| 3218 | bytes = ntohs(p.ip.ip_len); |
| 3219 | if (data_len < bytes) { |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 3220 | syslog(LOG_WARNING, "packet appears truncated " |
| 3221 | "(len=%zd, ip_len=%zd)", data_len, bytes); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3222 | errno = EINVAL; |
| 3223 | return -1; |
| 3224 | } |
| 3225 | |
| 3226 | if (noudpcsum == 0) { |
| 3227 | udpsum = p.udp.uh_sum; |
| 3228 | p.udp.uh_sum = 0; |
| 3229 | p.ip.ip_hl = 0; |
| 3230 | p.ip.ip_v = 0; |
| 3231 | p.ip.ip_tos = 0; |
| 3232 | p.ip.ip_len = p.udp.uh_ulen; |
| 3233 | p.ip.ip_id = 0; |
| 3234 | p.ip.ip_off = 0; |
| 3235 | p.ip.ip_ttl = 0; |
| 3236 | p.ip.ip_sum = 0; |
| 3237 | if (udpsum && checksum(&p, bytes) != udpsum) { |
Samuel Tan | 24aa62e | 2015-08-13 17:12:30 -0700 | [diff] [blame] | 3238 | syslog(LOG_WARNING, "packet failed udp checksum"); |
Samuel Tan | d7ed851 | 2015-08-13 16:11:35 -0700 | [diff] [blame] | 3239 | errno = EINVAL; |
| 3240 | return -1; |
| 3241 | } |
| 3242 | } |
| 3243 | |
| 3244 | return 0; |
| 3245 | } |
| 3246 | |
| 3247 | static void |
| 3248 | dhcp_handlepacket(void *arg) |
| 3249 | { |
| 3250 | struct interface *ifp = arg; |
| 3251 | struct dhcp_message *dhcp = NULL; |
| 3252 | const uint8_t *pp; |
| 3253 | size_t bytes; |
| 3254 | struct in_addr from; |
| 3255 | int i, flags; |
| 3256 | const struct dhcp_state *state = D_CSTATE(ifp); |
| 3257 | |
| 3258 | /* Need this API due to BPF */ |
| 3259 | flags = 0; |
| 3260 | while (!(flags & RAW_EOF)) { |
| 3261 | bytes = (size_t)if_readrawpacket(ifp, ETHERTYPE_IP, |
| 3262 | ifp->ctx->packet, udp_dhcp_len, &flags); |
| 3263 | if ((ssize_t)bytes == -1) { |
| 3264 | logger(ifp->ctx, LOG_ERR, |
| 3265 | "%s: dhcp if_readrawpacket: %m", ifp->name); |
| 3266 | dhcp_close(ifp); |
| 3267 | arp_close(ifp); |
| 3268 | break; |
| 3269 | } |
| 3270 | if (valid_udp_packet(ifp->ctx->packet, bytes, |
| 3271 | &from, flags & RAW_PARTIALCSUM) == -1) |
| 3272 | { |
| 3273 | logger(ifp->ctx, LOG_ERR, |
| 3274 | "%s: invalid UDP packet from %s", |
| 3275 | ifp->name, inet_ntoa(from)); |
| 3276 | continue; |
| 3277 | } |
| 3278 | i = whitelisted_ip(ifp->options, from.s_addr); |
| 3279 | if (i == 0) { |
| 3280 | logger(ifp->ctx, LOG_WARNING, |
| 3281 | "%s: non whitelisted DHCP packet from %s", |
| 3282 | ifp->name, inet_ntoa(from)); |
| 3283 | continue; |
| 3284 | } else if (i != 1 && |
| 3285 | blacklisted_ip(ifp->options, from.s_addr) == 1) |
| 3286 | { |
| 3287 | logger(ifp->ctx, LOG_WARNING, |
| 3288 | "%s: blacklisted DHCP packet from %s", |
| 3289 | ifp->name, inet_ntoa(from)); |
| 3290 | continue; |
| 3291 | } |
| 3292 | if (ifp->flags & IFF_POINTOPOINT && |
| 3293 | state->dst.s_addr != from.s_addr) |
| 3294 | { |
| 3295 | logger(ifp->ctx, LOG_WARNING, |
| 3296 | "%s: server %s is not destination", |
| 3297 | ifp->name, inet_ntoa(from)); |
| 3298 | } |
| 3299 | bytes = get_udp_data(&pp, ifp->ctx->packet); |
| 3300 | if (bytes > sizeof(*dhcp)) { |
| 3301 | logger(ifp->ctx, LOG_ERR, |
| 3302 | "%s: packet greater than DHCP size from %s", |
| 3303 | ifp->name, inet_ntoa(from)); |
| 3304 | continue; |
| 3305 | } |
| 3306 | if (dhcp == NULL) { |
| 3307 | dhcp = calloc(1, sizeof(*dhcp)); |
| 3308 | if (dhcp == NULL) { |
| 3309 | logger(ifp->ctx, LOG_ERR, |
| 3310 | "%s: calloc: %m", __func__); |
| 3311 | break; |
| 3312 | } |
| 3313 | } |
| 3314 | memcpy(dhcp, pp, bytes); |
| 3315 | if (dhcp->cookie != htonl(MAGIC_COOKIE)) { |
| 3316 | logger(ifp->ctx, LOG_DEBUG, "%s: bogus cookie from %s", |
| 3317 | ifp->name, inet_ntoa(from)); |
| 3318 | continue; |
| 3319 | } |
| 3320 | /* Ensure packet is for us */ |
| 3321 | if (ifp->hwlen <= sizeof(dhcp->chaddr) && |
| 3322 | memcmp(dhcp->chaddr, ifp->hwaddr, ifp->hwlen)) |
| 3323 | { |
| 3324 | char buf[sizeof(dhcp->chaddr) * 3]; |
| 3325 | |
| 3326 | logger(ifp->ctx, LOG_DEBUG, |
| 3327 | "%s: xid 0x%x is for hwaddr %s", |
| 3328 | ifp->name, ntohl(dhcp->xid), |
| 3329 | hwaddr_ntoa(dhcp->chaddr, sizeof(dhcp->chaddr), |
| 3330 | buf, sizeof(buf))); |
| 3331 | continue; |
| 3332 | } |
| 3333 | dhcp_handledhcp(ifp, &dhcp, &from); |
| 3334 | if (state->raw_fd == -1) |
| 3335 | break; |
| 3336 | } |
| 3337 | free(dhcp); |
| 3338 | } |
| 3339 | |
| 3340 | static void |
| 3341 | dhcp_handleudp(void *arg) |
| 3342 | { |
| 3343 | struct dhcpcd_ctx *ctx; |
| 3344 | uint8_t buffer[sizeof(struct dhcp_message)]; |
| 3345 | |
| 3346 | ctx = arg; |
| 3347 | |
| 3348 | /* Just read what's in the UDP fd and discard it as we always read |
| 3349 | * from the raw fd */ |
| 3350 | if (read(ctx->udp_fd, buffer, sizeof(buffer)) == -1) { |
| 3351 | logger(ctx, LOG_ERR, "%s: %m", __func__); |
| 3352 | eloop_event_delete(ctx->eloop, ctx->udp_fd, 0); |
| 3353 | close(ctx->udp_fd); |
| 3354 | ctx->udp_fd = -1; |
| 3355 | } |
| 3356 | } |
| 3357 | |
| 3358 | static int |
| 3359 | dhcp_open(struct interface *ifp) |
| 3360 | { |
| 3361 | struct dhcp_state *state; |
| 3362 | |
| 3363 | if (ifp->ctx->packet == NULL) { |
| 3364 | ifp->ctx->packet = malloc(udp_dhcp_len); |
| 3365 | if (ifp->ctx->packet == NULL) { |
| 3366 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 3367 | return -1; |
| 3368 | } |
| 3369 | } |
| 3370 | |
| 3371 | state = D_STATE(ifp); |
| 3372 | if (state->raw_fd == -1) { |
| 3373 | state->raw_fd = if_openrawsocket(ifp, ETHERTYPE_IP); |
| 3374 | if (state->raw_fd == -1) { |
| 3375 | if (errno == ENOENT) { |
| 3376 | logger(ifp->ctx, LOG_ERR, |
| 3377 | "%s not found", if_pfname); |
| 3378 | /* May as well disable IPv4 entirely at |
| 3379 | * this point as we really need it. */ |
| 3380 | ifp->options->options &= ~DHCPCD_IPV4; |
| 3381 | } else |
| 3382 | logger(ifp->ctx, LOG_ERR, "%s: %s: %m", |
| 3383 | __func__, ifp->name); |
| 3384 | return -1; |
| 3385 | } |
| 3386 | eloop_event_add(ifp->ctx->eloop, |
| 3387 | state->raw_fd, dhcp_handlepacket, ifp, NULL, NULL); |
| 3388 | } |
| 3389 | return 0; |
| 3390 | } |
| 3391 | |
| 3392 | int |
| 3393 | dhcp_dump(struct interface *ifp) |
| 3394 | { |
| 3395 | struct dhcp_state *state; |
| 3396 | |
| 3397 | ifp->if_data[IF_DATA_DHCP] = state = calloc(1, sizeof(*state)); |
| 3398 | if (state == NULL) |
| 3399 | goto eexit; |
| 3400 | state->raw_fd = state->arp_fd = -1; |
| 3401 | TAILQ_INIT(&state->arp_states); |
| 3402 | dhcp_set_leasefile(state->leasefile, sizeof(state->leasefile), |
| 3403 | AF_INET, ifp, ""); |
| 3404 | state->new = read_lease(ifp); |
| 3405 | if (state->new == NULL) { |
| 3406 | logger(ifp->ctx, LOG_ERR, "%s: %s: %m", |
| 3407 | *ifp->name ? ifp->name : state->leasefile, __func__); |
| 3408 | return -1; |
| 3409 | } |
| 3410 | state->reason = "DUMP"; |
| 3411 | return script_runreason(ifp, state->reason); |
| 3412 | |
| 3413 | eexit: |
| 3414 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 3415 | return -1; |
| 3416 | } |
| 3417 | |
| 3418 | void |
| 3419 | dhcp_free(struct interface *ifp) |
| 3420 | { |
| 3421 | struct dhcp_state *state = D_STATE(ifp); |
| 3422 | struct dhcpcd_ctx *ctx; |
| 3423 | |
| 3424 | dhcp_close(ifp); |
| 3425 | arp_close(ifp); |
| 3426 | if (state) { |
| 3427 | free(state->old); |
| 3428 | free(state->new); |
| 3429 | free(state->offer); |
| 3430 | free(state->buffer); |
| 3431 | free(state->clientid); |
| 3432 | free(state); |
| 3433 | ifp->if_data[IF_DATA_DHCP] = NULL; |
| 3434 | } |
| 3435 | |
| 3436 | ctx = ifp->ctx; |
| 3437 | /* If we don't have any more DHCP enabled interfaces, |
| 3438 | * close the global socket and release resources */ |
| 3439 | if (ctx->ifaces) { |
| 3440 | TAILQ_FOREACH(ifp, ctx->ifaces, next) { |
| 3441 | if (D_STATE(ifp)) |
| 3442 | break; |
| 3443 | } |
| 3444 | } |
| 3445 | if (ifp == NULL) { |
| 3446 | if (ctx->udp_fd != -1) { |
| 3447 | eloop_event_delete(ctx->eloop, ctx->udp_fd, 0); |
| 3448 | close(ctx->udp_fd); |
| 3449 | ctx->udp_fd = -1; |
| 3450 | } |
| 3451 | |
| 3452 | free(ctx->packet); |
| 3453 | free(ctx->opt_buffer); |
| 3454 | ctx->packet = NULL; |
| 3455 | ctx->opt_buffer = NULL; |
| 3456 | } |
| 3457 | } |
| 3458 | |
| 3459 | static int |
| 3460 | dhcp_init(struct interface *ifp) |
| 3461 | { |
| 3462 | struct dhcp_state *state; |
| 3463 | const struct if_options *ifo; |
| 3464 | uint8_t len; |
| 3465 | char buf[(sizeof(ifo->clientid) - 1) * 3]; |
| 3466 | |
| 3467 | state = D_STATE(ifp); |
| 3468 | if (state == NULL) { |
| 3469 | ifp->if_data[IF_DATA_DHCP] = calloc(1, sizeof(*state)); |
| 3470 | state = D_STATE(ifp); |
| 3471 | if (state == NULL) |
| 3472 | return -1; |
| 3473 | /* 0 is a valid fd, so init to -1 */ |
| 3474 | state->raw_fd = state->arp_fd = -1; |
| 3475 | TAILQ_INIT(&state->arp_states); |
| 3476 | |
| 3477 | /* Now is a good time to find IPv4 routes */ |
| 3478 | if_initrt(ifp); |
| 3479 | } |
| 3480 | |
| 3481 | state->state = DHS_INIT; |
| 3482 | state->reason = "PREINIT"; |
| 3483 | state->nakoff = 0; |
| 3484 | dhcp_set_leasefile(state->leasefile, sizeof(state->leasefile), |
| 3485 | AF_INET, ifp, ""); |
| 3486 | |
| 3487 | ifo = ifp->options; |
| 3488 | /* We need to drop the leasefile so that dhcp_start |
| 3489 | * doesn't load it. */ |
| 3490 | if (ifo->options & DHCPCD_REQUEST) |
| 3491 | unlink(state->leasefile); |
| 3492 | |
| 3493 | free(state->clientid); |
| 3494 | state->clientid = NULL; |
| 3495 | |
| 3496 | if (*ifo->clientid) { |
| 3497 | state->clientid = malloc((size_t)(ifo->clientid[0] + 1)); |
| 3498 | if (state->clientid == NULL) |
| 3499 | goto eexit; |
| 3500 | memcpy(state->clientid, ifo->clientid, |
| 3501 | (size_t)(ifo->clientid[0]) + 1); |
| 3502 | } else if (ifo->options & DHCPCD_CLIENTID) { |
| 3503 | if (ifo->options & DHCPCD_DUID) { |
| 3504 | state->clientid = malloc(ifp->ctx->duid_len + 6); |
| 3505 | if (state->clientid == NULL) |
| 3506 | goto eexit; |
| 3507 | state->clientid[0] =(uint8_t)(ifp->ctx->duid_len + 5); |
| 3508 | state->clientid[1] = 255; /* RFC 4361 */ |
| 3509 | memcpy(state->clientid + 2, ifo->iaid, 4); |
| 3510 | memcpy(state->clientid + 6, ifp->ctx->duid, |
| 3511 | ifp->ctx->duid_len); |
| 3512 | } else { |
| 3513 | len = (uint8_t)(ifp->hwlen + 1); |
| 3514 | state->clientid = malloc((size_t)len + 1); |
| 3515 | if (state->clientid == NULL) |
| 3516 | goto eexit; |
| 3517 | state->clientid[0] = len; |
| 3518 | state->clientid[1] = (uint8_t)ifp->family; |
| 3519 | memcpy(state->clientid + 2, ifp->hwaddr, |
| 3520 | ifp->hwlen); |
| 3521 | } |
| 3522 | } |
| 3523 | |
| 3524 | if (ifo->options & DHCPCD_DUID) |
| 3525 | /* Don't bother logging as DUID and IAID are reported |
| 3526 | * at device start. */ |
| 3527 | return 0; |
| 3528 | |
| 3529 | if (ifo->options & DHCPCD_CLIENTID) |
| 3530 | logger(ifp->ctx, LOG_DEBUG, "%s: using ClientID %s", ifp->name, |
| 3531 | hwaddr_ntoa(state->clientid + 1, state->clientid[0], |
| 3532 | buf, sizeof(buf))); |
| 3533 | else if (ifp->hwlen) |
| 3534 | logger(ifp->ctx, LOG_DEBUG, "%s: using hwaddr %s", ifp->name, |
| 3535 | hwaddr_ntoa(ifp->hwaddr, ifp->hwlen, buf, sizeof(buf))); |
| 3536 | return 0; |
| 3537 | |
| 3538 | eexit: |
| 3539 | logger(ifp->ctx, LOG_ERR, "%s: error making ClientID: %m", __func__); |
| 3540 | return -1; |
| 3541 | } |
| 3542 | |
| 3543 | static void |
| 3544 | dhcp_start1(void *arg) |
| 3545 | { |
| 3546 | struct interface *ifp = arg; |
| 3547 | struct if_options *ifo = ifp->options; |
| 3548 | struct dhcp_state *state; |
| 3549 | struct stat st; |
| 3550 | uint32_t l; |
| 3551 | int nolease; |
| 3552 | |
| 3553 | if (!(ifo->options & DHCPCD_IPV4)) |
| 3554 | return; |
| 3555 | |
| 3556 | /* Listen on *.*.*.*:bootpc so that the kernel never sends an |
| 3557 | * ICMP port unreachable message back to the DHCP server */ |
| 3558 | if (ifp->ctx->udp_fd == -1) { |
| 3559 | ifp->ctx->udp_fd = dhcp_openudp(NULL); |
| 3560 | if (ifp->ctx->udp_fd == -1) { |
| 3561 | /* Don't log an error if some other process |
| 3562 | * is handling this. */ |
| 3563 | if (errno != EADDRINUSE) |
| 3564 | logger(ifp->ctx, LOG_ERR, |
| 3565 | "%s: dhcp_openudp: %m", __func__); |
| 3566 | } else |
| 3567 | eloop_event_add(ifp->ctx->eloop, |
| 3568 | ifp->ctx->udp_fd, dhcp_handleudp, |
| 3569 | ifp->ctx, NULL, NULL); |
| 3570 | } |
| 3571 | |
| 3572 | if (dhcp_init(ifp) == -1) { |
| 3573 | logger(ifp->ctx, LOG_ERR, "%s: dhcp_init: %m", ifp->name); |
| 3574 | return; |
| 3575 | } |
| 3576 | |
| 3577 | state = D_STATE(ifp); |
| 3578 | state->start_uptime = uptime(); |
| 3579 | free(state->offer); |
| 3580 | state->offer = NULL; |
| 3581 | |
| 3582 | if (state->arping_index < ifo->arping_len) { |
| 3583 | struct arp_state *astate; |
| 3584 | |
| 3585 | astate = arp_new(ifp, NULL); |
| 3586 | if (astate) { |
| 3587 | astate->probed_cb = dhcp_arp_probed; |
| 3588 | astate->conflicted_cb = dhcp_arp_conflicted; |
| 3589 | dhcp_arp_probed(astate); |
| 3590 | } |
| 3591 | return; |
| 3592 | } |
| 3593 | |
| 3594 | if (ifo->options & DHCPCD_STATIC) { |
| 3595 | dhcp_static(ifp); |
| 3596 | return; |
| 3597 | } |
| 3598 | |
| 3599 | if (ifo->options & DHCPCD_DHCP && dhcp_open(ifp) == -1) |
| 3600 | return; |
| 3601 | |
| 3602 | if (ifo->options & DHCPCD_INFORM) { |
| 3603 | dhcp_inform(ifp); |
| 3604 | return; |
| 3605 | } |
| 3606 | if (ifp->hwlen == 0 && ifo->clientid[0] == '\0') { |
| 3607 | logger(ifp->ctx, LOG_WARNING, |
| 3608 | "%s: needs a clientid to configure", ifp->name); |
| 3609 | dhcp_drop(ifp, "FAIL"); |
| 3610 | eloop_timeout_delete(ifp->ctx->eloop, NULL, ifp); |
| 3611 | return; |
| 3612 | } |
| 3613 | /* We don't want to read the old lease if we NAK an old test */ |
| 3614 | nolease = state->offer && ifp->ctx->options & DHCPCD_TEST; |
| 3615 | if (!nolease) { |
| 3616 | state->offer = read_lease(ifp); |
| 3617 | /* Check the saved lease matches the type we want */ |
| 3618 | if (state->offer) { |
| 3619 | #ifdef IN_IFF_DUPLICATED |
| 3620 | struct in_addr addr; |
| 3621 | struct ipv4_addr *ia; |
| 3622 | |
| 3623 | addr.s_addr = state->offer->yiaddr; |
| 3624 | ia = ipv4_iffindaddr(ifp, &addr, NULL); |
| 3625 | #endif |
| 3626 | |
| 3627 | if ((IS_BOOTP(ifp, state->offer) && |
| 3628 | !(ifo->options & DHCPCD_BOOTP)) || |
| 3629 | #ifdef IN_IFF_DUPLICATED |
| 3630 | (ia && ia->addr_flags & IN_IFF_DUPLICATED) || |
| 3631 | #endif |
| 3632 | (!IS_BOOTP(ifp, state->offer) && |
| 3633 | ifo->options & DHCPCD_BOOTP)) |
| 3634 | { |
| 3635 | free(state->offer); |
| 3636 | state->offer = NULL; |
| 3637 | } |
| 3638 | } |
| 3639 | } |
| 3640 | if (state->offer) { |
| 3641 | get_lease(ifp->ctx, &state->lease, state->offer); |
| 3642 | state->lease.frominfo = 1; |
| 3643 | if (state->new == NULL && |
| 3644 | ipv4_iffindaddr(ifp, &state->lease.addr, &state->lease.net)) |
| 3645 | { |
| 3646 | /* We still have the IP address from the last lease. |
| 3647 | * Fake add the address and routes from it so the lease |
| 3648 | * can be cleaned up. */ |
| 3649 | state->new = malloc(sizeof(*state->new)); |
| 3650 | if (state->new) { |
| 3651 | memcpy(state->new, state->offer, |
| 3652 | sizeof(*state->new)); |
| 3653 | state->addr = state->lease.addr; |
| 3654 | state->net = state->lease.net; |
| 3655 | state->added |= STATE_ADDED | STATE_FAKE; |
| 3656 | ipv4_buildroutes(ifp->ctx); |
| 3657 | } else |
| 3658 | logger(ifp->ctx, LOG_ERR, "%s: %m", __func__); |
| 3659 | } |
| 3660 | if (state->offer->cookie == 0) { |
| 3661 | if (state->offer->yiaddr == state->addr.s_addr) { |
| 3662 | free(state->offer); |
| 3663 | state->offer = NULL; |
| 3664 | } |
| 3665 | } else if (state->lease.leasetime != ~0U && |
| 3666 | stat(state->leasefile, &st) == 0) |
| 3667 | { |
| 3668 | time_t now; |
| 3669 | |
| 3670 | /* Offset lease times and check expiry */ |
| 3671 | now = time(NULL); |
| 3672 | if (now == -1 || |
| 3673 | (time_t)state->lease.leasetime < now - st.st_mtime) |
| 3674 | { |
| 3675 | logger(ifp->ctx, LOG_DEBUG, |
| 3676 | "%s: discarding expired lease", ifp->name); |
| 3677 | free(state->offer); |
| 3678 | state->offer = NULL; |
| 3679 | state->lease.addr.s_addr = 0; |
| 3680 | /* Technically we should discard the lease |
| 3681 | * as it's expired, just as DHCPv6 addresses |
| 3682 | * would be by the kernel. |
| 3683 | * However, this may violate POLA so |
| 3684 | * we currently leave it be. |
| 3685 | * If we get a totally different lease from |
| 3686 | * the DHCP server we'll drop it anyway, as |
| 3687 | * we will on any other event which would |
| 3688 | * trigger a lease drop. |
| 3689 | * This should only happen if dhcpcd stops |
| 3690 | * running and the lease expires before |
| 3691 | * dhcpcd starts again. */ |
| 3692 | #if 0 |
| 3693 | if (state->new) |
| 3694 | dhcp_drop(ifp, "EXPIRE"); |
| 3695 | #endif |
| 3696 | } else { |
| 3697 | l = (uint32_t)(now - st.st_mtime); |
| 3698 | state->lease.leasetime -= l; |
| 3699 | state->lease.renewaltime -= l; |
| 3700 | state->lease.rebindtime -= l; |
| 3701 | } |
| 3702 | } |
| 3703 | } |
| 3704 | |
| 3705 | if (!(ifo->options & DHCPCD_DHCP)) { |
| 3706 | if (ifo->options & DHCPCD_IPV4LL) { |
| 3707 | if (state->offer && state->offer->cookie != 0) { |
| 3708 | free(state->offer); |
| 3709 | state->offer = NULL; |
| 3710 | } |
| 3711 | ipv4ll_start(ifp); |
| 3712 | } |
| 3713 | return; |
| 3714 | } |
| 3715 | |
| 3716 | if (state->offer == NULL || state->offer->cookie == 0) |
| 3717 | dhcp_discover(ifp); |
| 3718 | else |
| 3719 | dhcp_reboot(ifp); |
| 3720 | } |
| 3721 | |
| 3722 | void |
| 3723 | dhcp_start(struct interface *ifp) |
| 3724 | { |
| 3725 | struct timespec tv; |
| 3726 | |
| 3727 | if (!(ifp->options->options & DHCPCD_IPV4)) |
| 3728 | return; |
| 3729 | |
| 3730 | /* No point in delaying a static configuration */ |
| 3731 | tv.tv_sec = DHCP_MIN_DELAY; |
| 3732 | tv.tv_nsec = (suseconds_t)arc4random_uniform( |
| 3733 | (DHCP_MAX_DELAY - DHCP_MIN_DELAY) * NSEC_PER_SEC); |
| 3734 | timespecnorm(&tv); |
| 3735 | logger(ifp->ctx, LOG_DEBUG, |
| 3736 | "%s: delaying IPv4 for %0.1f seconds", |
| 3737 | ifp->name, timespec_to_double(&tv)); |
| 3738 | |
| 3739 | eloop_timeout_add_tv(ifp->ctx->eloop, &tv, dhcp_start1, ifp); |
| 3740 | } |
| 3741 | |
| 3742 | void |
| 3743 | dhcp_handleifa(int cmd, struct interface *ifp, |
| 3744 | const struct in_addr *addr, |
| 3745 | const struct in_addr *net, |
| 3746 | const struct in_addr *dst, |
| 3747 | __unused int flags) |
| 3748 | { |
| 3749 | struct dhcp_state *state; |
| 3750 | struct if_options *ifo; |
| 3751 | uint8_t i; |
| 3752 | |
| 3753 | state = D_STATE(ifp); |
| 3754 | if (state == NULL) |
| 3755 | return; |
| 3756 | |
| 3757 | if (cmd == RTM_DELADDR) { |
| 3758 | if (state->addr.s_addr == addr->s_addr && |
| 3759 | state->net.s_addr == net->s_addr) |
| 3760 | { |
| 3761 | logger(ifp->ctx, LOG_INFO, |
| 3762 | "%s: removing IP address %s/%d", |
| 3763 | ifp->name, inet_ntoa(state->addr), |
| 3764 | inet_ntocidr(state->net)); |
| 3765 | dhcp_drop(ifp, "EXPIRE"); |
| 3766 | } |
| 3767 | return; |
| 3768 | } |
| 3769 | |
| 3770 | if (cmd != RTM_NEWADDR) |
| 3771 | return; |
| 3772 | |
| 3773 | ifo = ifp->options; |
| 3774 | if (ifo->options & DHCPCD_INFORM) { |
| 3775 | if (state->state != DHS_INFORM) |
| 3776 | dhcp_inform(ifp); |
| 3777 | return; |
| 3778 | } |
| 3779 | |
| 3780 | if (!(ifo->options & DHCPCD_STATIC)) |
| 3781 | return; |
| 3782 | if (ifo->req_addr.s_addr != INADDR_ANY) |
| 3783 | return; |
| 3784 | |
| 3785 | free(state->old); |
| 3786 | state->old = state->new; |
| 3787 | state->new = dhcp_message_new(addr, net); |
| 3788 | if (state->new == NULL) |
| 3789 | return; |
| 3790 | state->dst.s_addr = dst ? dst->s_addr : INADDR_ANY; |
| 3791 | if (dst) { |
| 3792 | for (i = 1; i < 255; i++) |
| 3793 | if (i != DHO_ROUTER && has_option_mask(ifo->dstmask,i)) |
| 3794 | dhcp_message_add_addr(state->new, i, *dst); |
| 3795 | } |
| 3796 | state->reason = "STATIC"; |
| 3797 | ipv4_buildroutes(ifp->ctx); |
| 3798 | script_runreason(ifp, state->reason); |
| 3799 | if (ifo->options & DHCPCD_INFORM) { |
| 3800 | state->state = DHS_INFORM; |
| 3801 | state->xid = dhcp_xid(ifp); |
| 3802 | state->lease.server.s_addr = dst ? dst->s_addr : INADDR_ANY; |
| 3803 | state->addr = *addr; |
| 3804 | state->net = *net; |
| 3805 | dhcp_inform(ifp); |
| 3806 | } |
| 3807 | } |