1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * dhcpcd - DHCP client daemon 4 * Copyright (c) 2006-2019 Roy Marples <roy@marples.name> 5 * All rights reserved 6 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/stat.h> 30 #include <sys/uio.h> 31 #include <sys/wait.h> 32 33 #include <netinet/in.h> 34 #include <arpa/inet.h> 35 36 #include <assert.h> 37 #include <ctype.h> 38 #include <errno.h> 39 #include <signal.h> 40 #include <spawn.h> 41 #include <stdarg.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #include "config.h" 47 #include "common.h" 48 #include "dhcp.h" 49 #include "dhcp6.h" 50 #include "if.h" 51 #include "if-options.h" 52 #include "ipv4ll.h" 53 #include "ipv6nd.h" 54 #include "logerr.h" 55 #include "script.h" 56 57 /* Allow the OS to define another script env var name */ 58 #ifndef RC_SVCNAME 59 #define RC_SVCNAME "RC_SVCNAME" 60 #endif 61 62 #define DEFAULT_PATH "/usr/bin:/usr/sbin:/bin:/sbin" 63 64 static const char * const if_params[] = { 65 "interface", 66 "protocol", 67 "reason", 68 "pid", 69 "ifcarrier", 70 "ifmetric", 71 "ifwireless", 72 "ifflags", 73 "ssid", 74 "profile", 75 "interface_order", 76 NULL 77 }; 78 79 void 80 if_printoptions(void) 81 { 82 const char * const *p; 83 84 for (p = if_params; *p; p++) 85 printf(" - %s\n", *p); 86 } 87 88 static int 89 script_exec(const struct dhcpcd_ctx *ctx, char *const *argv, char *const *env) 90 { 91 pid_t pid = 0; 92 posix_spawnattr_t attr; 93 int r; 94 #ifdef USE_SIGNALS 95 size_t i; 96 short flags; 97 sigset_t defsigs; 98 #else 99 UNUSED(ctx); 100 #endif 101 102 /* posix_spawn is a safe way of executing another image 103 * and changing signals back to how they should be. */ 104 if (posix_spawnattr_init(&attr) == -1) 105 return -1; 106 #ifdef USE_SIGNALS 107 flags = POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF; 108 posix_spawnattr_setflags(&attr, flags); 109 sigemptyset(&defsigs); 110 for (i = 0; i < dhcpcd_signals_len; i++) 111 sigaddset(&defsigs, dhcpcd_signals[i]); 112 posix_spawnattr_setsigdefault(&attr, &defsigs); 113 posix_spawnattr_setsigmask(&attr, &ctx->sigset); 114 #endif 115 errno = 0; 116 r = posix_spawn(&pid, argv[0], NULL, &attr, argv, env); 117 posix_spawnattr_destroy(&attr); 118 if (r) { 119 errno = r; 120 return -1; 121 } 122 return pid; 123 } 124 125 #ifdef INET 126 static int 127 append_config(FILE *fp, const char *prefix, const char *const *config) 128 { 129 size_t i; 130 131 if (config == NULL) 132 return 0; 133 134 /* Do we need to replace existing config rather than append? */ 135 for (i = 0; config[i] != NULL; i++) { 136 if (efprintf(fp, "%s_%s", prefix, config[i]) == -1) 137 return -1; 138 } 139 return 1; 140 } 141 142 #endif 143 144 #define PROTO_LINK 0 145 #define PROTO_DHCP 1 146 #define PROTO_IPV4LL 2 147 #define PROTO_RA 3 148 #define PROTO_DHCP6 4 149 #define PROTO_STATIC6 5 150 static const char *protocols[] = { 151 "link", 152 "dhcp", 153 "ipv4ll", 154 "ra", 155 "dhcp6", 156 "static6" 157 }; 158 159 int 160 efprintf(FILE *fp, const char *fmt, ...) 161 { 162 va_list args; 163 int r; 164 165 va_start(args, fmt); 166 r = vfprintf(fp, fmt, args); 167 va_end(args); 168 if (r == -1) 169 return -1; 170 /* Write a trailing NULL so we can easily create env strings. */ 171 if (fputc('\0', fp) == EOF) 172 return -1; 173 return r; 174 } 175 176 static char ** 177 script_buftoenv(struct dhcpcd_ctx *ctx, char *buf, size_t len) 178 { 179 char **env, **envp, *bufp, *endp; 180 size_t nenv; 181 182 /* Count the terminated env strings. 183 * Assert that the terminations are correct. */ 184 nenv = 0; 185 endp = buf + len; 186 for (bufp = buf; bufp < endp; bufp++) { 187 if (*bufp == '\0') { 188 #ifndef NDEBUG 189 if (bufp + 1 < endp) 190 assert(*(bufp + 1) != '\0'); 191 #endif 192 nenv++; 193 } 194 } 195 assert(*(bufp - 1) == '\0'); 196 197 if (ctx->script_envlen < nenv) { 198 env = reallocarray(ctx->script_env, nenv + 1, sizeof(*env)); 199 if (env == NULL) 200 return NULL; 201 ctx->script_env = env; 202 ctx->script_envlen = nenv; 203 } 204 205 bufp = buf; 206 envp = ctx->script_env; 207 *envp++ = bufp++; 208 endp--; /* Avoid setting the last \0 to an invalid pointer */ 209 for (; bufp < endp; bufp++) { 210 if (*bufp == '\0') 211 *envp++ = bufp + 1; 212 } 213 *envp = NULL; 214 215 return ctx->script_env; 216 } 217 218 static long 219 make_env(const struct interface *ifp, const char *reason) 220 { 221 struct dhcpcd_ctx *ctx = ifp->ctx; 222 FILE *fp; 223 long buf_pos, i; 224 char *path; 225 int protocol = PROTO_LINK; 226 const struct if_options *ifo = ifp->options; 227 const struct interface *ifp2; 228 int af; 229 #ifdef INET 230 const struct dhcp_state *state; 231 #ifdef IPV4LL 232 const struct ipv4ll_state *istate; 233 #endif 234 #endif 235 #ifdef DHCP6 236 const struct dhcp6_state *d6_state; 237 #endif 238 239 #ifdef HAVE_OPEN_MEMSTREAM 240 if (ctx->script_fp == NULL) { 241 fp = open_memstream(&ctx->script_buf, &ctx->script_buflen); 242 if (fp == NULL) 243 goto eexit; 244 ctx->script_fp = fp; 245 } else { 246 fp = ctx->script_fp; 247 rewind(fp); 248 } 249 #else 250 char tmpfile[] = "/tmp/dhcpcd-script-env-XXXXXX"; 251 int tmpfd; 252 253 fp = NULL; 254 tmpfd = mkstemp(tmpfile); 255 if (tmpfd == -1) 256 goto eexit; 257 unlink(tmpfile); 258 fp = fdopen(tmpfd, "w+"); 259 if (fp == NULL) { 260 close(tmpfd); 261 goto eexit; 262 } 263 #endif 264 265 #ifdef INET 266 state = D_STATE(ifp); 267 #ifdef IPV4LL 268 istate = IPV4LL_CSTATE(ifp); 269 #endif 270 #endif 271 #ifdef DHCP6 272 d6_state = D6_CSTATE(ifp); 273 #endif 274 if (strcmp(reason, "TEST") == 0) { 275 if (1 == 2) {} 276 #ifdef INET6 277 #ifdef DHCP6 278 else if (d6_state && d6_state->new) 279 protocol = PROTO_DHCP6; 280 #endif 281 else if (ipv6nd_hasra(ifp)) 282 protocol = PROTO_RA; 283 #endif 284 #ifdef INET 285 #ifdef IPV4LL 286 else if (istate && istate->addr != NULL) 287 protocol = PROTO_IPV4LL; 288 #endif 289 else 290 protocol = PROTO_DHCP; 291 #endif 292 } 293 #ifdef INET6 294 else if (strcmp(reason, "STATIC6") == 0) 295 protocol = PROTO_STATIC6; 296 #ifdef DHCP6 297 else if (reason[strlen(reason) - 1] == '6') 298 protocol = PROTO_DHCP6; 299 #endif 300 else if (strcmp(reason, "ROUTERADVERT") == 0) 301 protocol = PROTO_RA; 302 #endif 303 else if (strcmp(reason, "PREINIT") == 0 || 304 strcmp(reason, "CARRIER") == 0 || 305 strcmp(reason, "NOCARRIER") == 0 || 306 strcmp(reason, "UNKNOWN") == 0 || 307 strcmp(reason, "DEPARTED") == 0 || 308 strcmp(reason, "STOPPED") == 0) 309 protocol = PROTO_LINK; 310 #ifdef INET 311 #ifdef IPV4LL 312 else if (strcmp(reason, "IPV4LL") == 0) 313 protocol = PROTO_IPV4LL; 314 #endif 315 else 316 protocol = PROTO_DHCP; 317 #endif 318 319 /* Needed for scripts */ 320 path = getenv("PATH"); 321 if (efprintf(fp, "PATH=%s", path == NULL ? DEFAULT_PATH:path) == -1) 322 goto eexit; 323 324 if (efprintf(fp, "interface=%s", ifp->name) == -1) 325 goto eexit; 326 if (efprintf(fp, "reason=%s", reason) == -1) 327 goto eexit; 328 if (ifp->ctx->options & DHCPCD_DUMPLEASE) 329 goto dumplease; 330 if (efprintf(fp, "pid=%d", getpid()) == -1) 331 goto eexit; 332 if (efprintf(fp, "ifcarrier=%s", 333 ifp->carrier == LINK_UNKNOWN ? "unknown" : 334 ifp->carrier == LINK_UP ? "up" : "down") == -1) 335 goto eexit; 336 if (efprintf(fp, "ifmetric=%d", ifp->metric) == -1) 337 goto eexit; 338 if (efprintf(fp, "ifwireless=%d", ifp->wireless) == -1) 339 goto eexit; 340 if (efprintf(fp, "ifflags=%u", ifp->flags) == -1) 341 goto eexit; 342 if (efprintf(fp, "ifmtu=%d", if_getmtu(ifp)) == -1) 343 goto eexit; 344 345 if (fprintf(fp, "interface_order=") == -1) 346 goto eexit; 347 TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) { 348 if (ifp2 != TAILQ_FIRST(ifp->ctx->ifaces)) { 349 if (fputc(' ', fp) == EOF) 350 return -1; 351 } 352 if (fprintf(fp, "%s", ifp2->name) == -1) 353 return -1; 354 } 355 if (fputc('\0', fp) == EOF) 356 return -1; 357 358 if (strcmp(reason, "STOPPED") == 0) { 359 if (efprintf(fp, "if_up=false") == -1) 360 goto eexit; 361 if (efprintf(fp, "if_down=%s", 362 ifo->options & DHCPCD_RELEASE ? "true" : "false") == -1) 363 goto eexit; 364 } else if (strcmp(reason, "TEST") == 0 || 365 strcmp(reason, "PREINIT") == 0 || 366 strcmp(reason, "CARRIER") == 0 || 367 strcmp(reason, "UNKNOWN") == 0) 368 { 369 if (efprintf(fp, "if_up=false") == -1) 370 goto eexit; 371 if (efprintf(fp, "if_down=false") == -1) 372 goto eexit; 373 } else if (1 == 2 /* appease ifdefs */ 374 #ifdef INET 375 || (protocol == PROTO_DHCP && state && state->new) 376 #ifdef IPV4LL 377 || (protocol == PROTO_IPV4LL && IPV4LL_STATE_RUNNING(ifp)) 378 #endif 379 #endif 380 #ifdef INET6 381 || (protocol == PROTO_STATIC6 && IPV6_STATE_RUNNING(ifp)) 382 #ifdef DHCP6 383 || (protocol == PROTO_DHCP6 && d6_state && d6_state->new) 384 #endif 385 || (protocol == PROTO_RA && ipv6nd_hasra(ifp)) 386 #endif 387 ) 388 { 389 if (efprintf(fp, "if_up=true") == -1) 390 goto eexit; 391 if (efprintf(fp, "if_down=false") == -1) 392 goto eexit; 393 } else { 394 if (efprintf(fp, "if_up=false") == -1) 395 goto eexit; 396 if (efprintf(fp, "if_down=true") == -1) 397 goto eexit; 398 } 399 if (protocols[protocol] != NULL) { 400 if (efprintf(fp, "protocol=%s", protocols[protocol]) == -1) 401 goto eexit; 402 } 403 if ((af = dhcpcd_ifafwaiting(ifp)) != AF_MAX) { 404 if (efprintf(fp, "if_afwaiting=%d", af) == -1) 405 goto eexit; 406 } 407 if ((af = dhcpcd_afwaiting(ifp->ctx)) != AF_MAX) { 408 TAILQ_FOREACH(ifp2, ifp->ctx->ifaces, next) { 409 if ((af = dhcpcd_ifafwaiting(ifp2)) != AF_MAX) 410 break; 411 } 412 } 413 if (af != AF_MAX) { 414 if (efprintf(fp, "af_waiting=%d", af) == -1) 415 goto eexit; 416 } 417 if (ifo->options & DHCPCD_DEBUG) { 418 if (efprintf(fp, "syslog_debug=true") == -1) 419 goto eexit; 420 } 421 if (*ifp->profile != '\0') { 422 if (efprintf(fp, "profile=%s", ifp->profile) == -1) 423 goto eexit; 424 } 425 if (ifp->wireless) { 426 char pssid[IF_SSIDLEN * 4]; 427 428 if (print_string(pssid, sizeof(pssid), OT_ESCSTRING, 429 ifp->ssid, ifp->ssid_len) != -1) 430 { 431 if (efprintf(fp, "ifssid=%s", pssid) == -1) 432 goto eexit; 433 } 434 } 435 #ifdef INET 436 if (protocol == PROTO_DHCP && state && state->old) { 437 if (dhcp_env(fp, "old", ifp, 438 state->old, state->old_len) == -1) 439 goto eexit; 440 if (append_config(fp, "old", 441 (const char *const *)ifo->config) == -1) 442 goto eexit; 443 } 444 #endif 445 #ifdef DHCP6 446 if (protocol == PROTO_DHCP6 && d6_state && d6_state->old) { 447 if (dhcp6_env(fp, "old", ifp, 448 d6_state->old, d6_state->old_len) == -1) 449 goto eexit; 450 } 451 #endif 452 453 dumplease: 454 #ifdef INET 455 #ifdef IPV4LL 456 if (protocol == PROTO_IPV4LL) { 457 if (ipv4ll_env(fp, istate->down ? "old" : "new", ifp) == -1) 458 goto eexit; 459 } 460 #endif 461 if (protocol == PROTO_DHCP && state && state->new) { 462 if (dhcp_env(fp, "new", ifp, 463 state->new, state->new_len) == -1) 464 goto eexit; 465 if (append_config(fp, "new", 466 (const char *const *)ifo->config) == -1) 467 goto eexit; 468 } 469 #endif 470 #ifdef INET6 471 if (protocol == PROTO_STATIC6) { 472 if (ipv6_env(fp, "new", ifp) == -1) 473 goto eexit; 474 } 475 #ifdef DHCP6 476 if (protocol == PROTO_DHCP6 && D6_STATE_RUNNING(ifp)) { 477 if (dhcp6_env(fp, "new", ifp, 478 d6_state->new, d6_state->new_len) == -1) 479 goto eexit; 480 } 481 #endif 482 if (protocol == PROTO_RA) { 483 if (ipv6nd_env(fp, ifp) == -1) 484 goto eexit; 485 } 486 #endif 487 488 /* Add our base environment */ 489 if (ifo->environ) { 490 for (i = 0; ifo->environ[i] != NULL; i++) 491 if (efprintf(fp, "%s", ifo->environ[i]) == -1) 492 goto eexit; 493 } 494 495 /* Convert buffer to argv */ 496 fflush(fp); 497 498 buf_pos = ftell(fp); 499 if (buf_pos == -1) { 500 logerr(__func__); 501 goto eexit; 502 } 503 504 #ifndef HAVE_OPEN_MEMSTREAM 505 size_t buf_len = (size_t)buf_pos; 506 if (ctx->script_buflen < buf_len) { 507 char *buf = realloc(ctx->script_buf, buf_len); 508 if (buf == NULL) 509 goto eexit; 510 ctx->script_buf = buf; 511 ctx->script_buflen = buf_len; 512 } 513 rewind(fp); 514 if (fread(ctx->script_buf, sizeof(char), buf_len, fp) != buf_len) 515 goto eexit; 516 fclose(fp); 517 fp = NULL; 518 #endif 519 520 if (script_buftoenv(ctx, ctx->script_buf, (size_t)buf_pos) == NULL) 521 goto eexit; 522 523 return buf_pos - 1; 524 525 eexit: 526 logerr(__func__); 527 #ifndef HAVE_OPEN_MEMSTREAM 528 if (fp != NULL) 529 fclose(fp); 530 #endif 531 return -1; 532 } 533 534 static int 535 send_interface1(struct fd_list *fd, const struct interface *ifp, 536 const char *reason) 537 { 538 struct dhcpcd_ctx *ctx = ifp->ctx; 539 long len; 540 541 len = make_env(ifp, reason); 542 if (len == -1) 543 return -1; 544 return control_queue(fd, ctx->script_buf, (size_t)len, 1); 545 } 546 547 int 548 send_interface(struct fd_list *fd, const struct interface *ifp) 549 { 550 const char *reason; 551 int retval = 0; 552 #ifdef INET 553 const struct dhcp_state *d; 554 #endif 555 #ifdef DHCP6 556 const struct dhcp6_state *d6; 557 #endif 558 559 switch (ifp->carrier) { 560 case LINK_UP: 561 reason = "CARRIER"; 562 break; 563 case LINK_DOWN: 564 case LINK_DOWN_IFFUP: 565 reason = "NOCARRIER"; 566 break; 567 default: 568 reason = "UNKNOWN"; 569 break; 570 } 571 if (send_interface1(fd, ifp, reason) == -1) 572 retval = -1; 573 #ifdef INET 574 if (D_STATE_RUNNING(ifp)) { 575 d = D_CSTATE(ifp); 576 if (send_interface1(fd, ifp, d->reason) == -1) 577 retval = -1; 578 } 579 #ifdef IPV4LL 580 if (IPV4LL_STATE_RUNNING(ifp)) { 581 if (send_interface1(fd, ifp, "IPV4LL") == -1) 582 retval = -1; 583 } 584 #endif 585 #endif 586 587 #ifdef INET6 588 if (IPV6_STATE_RUNNING(ifp)) { 589 if (send_interface1(fd, ifp, "STATIC6") == -1) 590 retval = -1; 591 } 592 if (RS_STATE_RUNNING(ifp)) { 593 if (send_interface1(fd, ifp, "ROUTERADVERT") == -1) 594 retval = -1; 595 } 596 #ifdef DHCP6 597 if (D6_STATE_RUNNING(ifp)) { 598 d6 = D6_CSTATE(ifp); 599 if (send_interface1(fd, ifp, d6->reason) == -1) 600 retval = -1; 601 } 602 #endif 603 #endif 604 605 return retval; 606 } 607 608 int 609 script_runreason(const struct interface *ifp, const char *reason) 610 { 611 struct dhcpcd_ctx *ctx = ifp->ctx; 612 char *argv[2]; 613 pid_t pid; 614 int status = 0; 615 struct fd_list *fd; 616 617 if (ifp->options->script == NULL && 618 TAILQ_FIRST(&ifp->ctx->control_fds) == NULL) 619 return 0; 620 621 /* Make our env */ 622 if (make_env(ifp, reason) == -1) { 623 logerr(__func__); 624 return -1; 625 } 626 627 if (ifp->options->script == NULL) 628 goto send_listeners; 629 630 argv[0] = ifp->options->script; 631 argv[1] = NULL; 632 logdebugx("%s: executing `%s' %s", ifp->name, argv[0], reason); 633 634 pid = script_exec(ctx, argv, ctx->script_env); 635 if (pid == -1) 636 logerr("%s: %s", __func__, argv[0]); 637 else if (pid != 0) { 638 /* Wait for the script to finish */ 639 while (waitpid(pid, &status, 0) == -1) { 640 if (errno != EINTR) { 641 logerr("%s: waitpid", __func__); 642 status = 0; 643 break; 644 } 645 } 646 if (WIFEXITED(status)) { 647 if (WEXITSTATUS(status)) 648 logerrx("%s: %s: WEXITSTATUS %d", 649 __func__, argv[0], WEXITSTATUS(status)); 650 } else if (WIFSIGNALED(status)) 651 logerrx("%s: %s: %s", 652 __func__, argv[0], strsignal(WTERMSIG(status))); 653 } 654 655 send_listeners: 656 /* Send to our listeners */ 657 status = 0; 658 TAILQ_FOREACH(fd, &ctx->control_fds, next) { 659 if (!(fd->flags & FD_LISTEN)) 660 continue; 661 if (control_queue(fd, ctx->script_buf, ctx->script_buflen, 662 true) == -1) 663 logerr("%s: control_queue", __func__); 664 else 665 status = 1; 666 } 667 668 return WEXITSTATUS(status); 669 } 670