1 /* $OpenBSD: misc.c,v 1.198 2024/10/24 03:14:37 djm Exp $ */ 2 /* 3 * Copyright (c) 2000 Markus Friedl. All rights reserved. 4 * Copyright (c) 2005-2020 Damien Miller. All rights reserved. 5 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 21 #include <sys/types.h> 22 #include <sys/ioctl.h> 23 #include <sys/socket.h> 24 #include <sys/stat.h> 25 #include <sys/time.h> 26 #include <sys/wait.h> 27 #include <sys/un.h> 28 29 #include <net/if.h> 30 #include <netinet/in.h> 31 #include <netinet/ip.h> 32 #include <netinet/tcp.h> 33 #include <arpa/inet.h> 34 35 #include <ctype.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <netdb.h> 39 #include <paths.h> 40 #include <pwd.h> 41 #include <libgen.h> 42 #include <limits.h> 43 #include <nlist.h> 44 #include <poll.h> 45 #include <signal.h> 46 #include <stdarg.h> 47 #include <stdio.h> 48 #include <stdint.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 53 #include "xmalloc.h" 54 #include "misc.h" 55 #include "log.h" 56 #include "ssh.h" 57 #include "sshbuf.h" 58 #include "ssherr.h" 59 60 /* remove newline at end of string */ 61 char * 62 chop(char *s) 63 { 64 char *t = s; 65 while (*t) { 66 if (*t == '\n' || *t == '\r') { 67 *t = '\0'; 68 return s; 69 } 70 t++; 71 } 72 return s; 73 74 } 75 76 /* remove whitespace from end of string */ 77 void 78 rtrim(char *s) 79 { 80 size_t i; 81 82 if ((i = strlen(s)) == 0) 83 return; 84 for (i--; i > 0; i--) { 85 if (isspace((unsigned char)s[i])) 86 s[i] = '\0'; 87 } 88 } 89 90 /* 91 * returns pointer to character after 'prefix' in 's' or otherwise NULL 92 * if the prefix is not present. 93 */ 94 const char * 95 strprefix(const char *s, const char *prefix, int ignorecase) 96 { 97 size_t prefixlen; 98 99 if ((prefixlen = strlen(prefix)) == 0) 100 return s; 101 if (ignorecase) { 102 if (strncasecmp(s, prefix, prefixlen) != 0) 103 return NULL; 104 } else { 105 if (strncmp(s, prefix, prefixlen) != 0) 106 return NULL; 107 } 108 return s + prefixlen; 109 } 110 111 /* set/unset filedescriptor to non-blocking */ 112 int 113 set_nonblock(int fd) 114 { 115 int val; 116 117 val = fcntl(fd, F_GETFL); 118 if (val == -1) { 119 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 120 return (-1); 121 } 122 if (val & O_NONBLOCK) { 123 debug3("fd %d is O_NONBLOCK", fd); 124 return (0); 125 } 126 debug2("fd %d setting O_NONBLOCK", fd); 127 val |= O_NONBLOCK; 128 if (fcntl(fd, F_SETFL, val) == -1) { 129 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 130 strerror(errno)); 131 return (-1); 132 } 133 return (0); 134 } 135 136 int 137 unset_nonblock(int fd) 138 { 139 int val; 140 141 val = fcntl(fd, F_GETFL); 142 if (val == -1) { 143 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 144 return (-1); 145 } 146 if (!(val & O_NONBLOCK)) { 147 debug3("fd %d is not O_NONBLOCK", fd); 148 return (0); 149 } 150 debug("fd %d clearing O_NONBLOCK", fd); 151 val &= ~O_NONBLOCK; 152 if (fcntl(fd, F_SETFL, val) == -1) { 153 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 154 fd, strerror(errno)); 155 return (-1); 156 } 157 return (0); 158 } 159 160 const char * 161 ssh_gai_strerror(int gaierr) 162 { 163 if (gaierr == EAI_SYSTEM && errno != 0) 164 return strerror(errno); 165 return gai_strerror(gaierr); 166 } 167 168 /* disable nagle on socket */ 169 void 170 set_nodelay(int fd) 171 { 172 int opt; 173 socklen_t optlen; 174 175 optlen = sizeof opt; 176 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 177 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 178 return; 179 } 180 if (opt == 1) { 181 debug2("fd %d is TCP_NODELAY", fd); 182 return; 183 } 184 opt = 1; 185 debug2("fd %d setting TCP_NODELAY", fd); 186 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 187 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 188 } 189 190 /* Allow local port reuse in TIME_WAIT */ 191 int 192 set_reuseaddr(int fd) 193 { 194 int on = 1; 195 196 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 197 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 198 return -1; 199 } 200 return 0; 201 } 202 203 /* Get/set routing domain */ 204 char * 205 get_rdomain(int fd) 206 { 207 int rtable; 208 char *ret; 209 socklen_t len = sizeof(rtable); 210 211 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 212 error("Failed to get routing domain for fd %d: %s", 213 fd, strerror(errno)); 214 return NULL; 215 } 216 xasprintf(&ret, "%d", rtable); 217 return ret; 218 } 219 220 int 221 set_rdomain(int fd, const char *name) 222 { 223 int rtable; 224 const char *errstr; 225 226 if (name == NULL) 227 return 0; /* default table */ 228 229 rtable = (int)strtonum(name, 0, 255, &errstr); 230 if (errstr != NULL) { 231 /* Shouldn't happen */ 232 error("Invalid routing domain \"%s\": %s", name, errstr); 233 return -1; 234 } 235 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 236 &rtable, sizeof(rtable)) == -1) { 237 error("Failed to set routing domain %d on fd %d: %s", 238 rtable, fd, strerror(errno)); 239 return -1; 240 } 241 return 0; 242 } 243 244 int 245 get_sock_af(int fd) 246 { 247 struct sockaddr_storage to; 248 socklen_t tolen = sizeof(to); 249 250 memset(&to, 0, sizeof(to)); 251 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 252 return -1; 253 return to.ss_family; 254 } 255 256 void 257 set_sock_tos(int fd, int tos) 258 { 259 int af; 260 261 switch ((af = get_sock_af(fd))) { 262 case -1: 263 /* assume not a socket */ 264 break; 265 case AF_INET: 266 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 267 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 268 &tos, sizeof(tos)) == -1) { 269 error("setsockopt socket %d IP_TOS %d: %s", 270 fd, tos, strerror(errno)); 271 } 272 break; 273 case AF_INET6: 274 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 275 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 276 &tos, sizeof(tos)) == -1) { 277 error("setsockopt socket %d IPV6_TCLASS %d: %s", 278 fd, tos, strerror(errno)); 279 } 280 break; 281 default: 282 debug2_f("unsupported socket family %d", af); 283 break; 284 } 285 } 286 287 /* 288 * Wait up to *timeoutp milliseconds for events on fd. Updates 289 * *timeoutp with time remaining. 290 * Returns 0 if fd ready or -1 on timeout or error (see errno). 291 */ 292 static int 293 waitfd(int fd, int *timeoutp, short events, volatile sig_atomic_t *stop) 294 { 295 struct pollfd pfd; 296 struct timespec timeout; 297 int oerrno, r; 298 sigset_t nsigset, osigset; 299 300 if (timeoutp && *timeoutp == -1) 301 timeoutp = NULL; 302 pfd.fd = fd; 303 pfd.events = events; 304 ptimeout_init(&timeout); 305 if (timeoutp != NULL) 306 ptimeout_deadline_ms(&timeout, *timeoutp); 307 if (stop != NULL) 308 sigfillset(&nsigset); 309 for (; timeoutp == NULL || *timeoutp >= 0;) { 310 if (stop != NULL) { 311 sigprocmask(SIG_BLOCK, &nsigset, &osigset); 312 if (*stop) { 313 sigprocmask(SIG_SETMASK, &osigset, NULL); 314 errno = EINTR; 315 return -1; 316 } 317 } 318 r = ppoll(&pfd, 1, ptimeout_get_tsp(&timeout), 319 stop != NULL ? &osigset : NULL); 320 oerrno = errno; 321 if (stop != NULL) 322 sigprocmask(SIG_SETMASK, &osigset, NULL); 323 if (timeoutp) 324 *timeoutp = ptimeout_get_ms(&timeout); 325 errno = oerrno; 326 if (r > 0) 327 return 0; 328 else if (r == -1 && errno != EAGAIN && errno != EINTR) 329 return -1; 330 else if (r == 0) 331 break; 332 } 333 /* timeout */ 334 errno = ETIMEDOUT; 335 return -1; 336 } 337 338 /* 339 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 340 * *timeoutp with time remaining. 341 * Returns 0 if fd ready or -1 on timeout or error (see errno). 342 */ 343 int 344 waitrfd(int fd, int *timeoutp, volatile sig_atomic_t *stop) { 345 return waitfd(fd, timeoutp, POLLIN, stop); 346 } 347 348 /* 349 * Attempt a non-blocking connect(2) to the specified address, waiting up to 350 * *timeoutp milliseconds for the connection to complete. If the timeout is 351 * <=0, then wait indefinitely. 352 * 353 * Returns 0 on success or -1 on failure. 354 */ 355 int 356 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 357 socklen_t addrlen, int *timeoutp) 358 { 359 int optval = 0; 360 socklen_t optlen = sizeof(optval); 361 362 /* No timeout: just do a blocking connect() */ 363 if (timeoutp == NULL || *timeoutp <= 0) 364 return connect(sockfd, serv_addr, addrlen); 365 366 set_nonblock(sockfd); 367 for (;;) { 368 if (connect(sockfd, serv_addr, addrlen) == 0) { 369 /* Succeeded already? */ 370 unset_nonblock(sockfd); 371 return 0; 372 } else if (errno == EINTR) 373 continue; 374 else if (errno != EINPROGRESS) 375 return -1; 376 break; 377 } 378 379 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT, NULL) == -1) 380 return -1; 381 382 /* Completed or failed */ 383 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 384 debug("getsockopt: %s", strerror(errno)); 385 return -1; 386 } 387 if (optval != 0) { 388 errno = optval; 389 return -1; 390 } 391 unset_nonblock(sockfd); 392 return 0; 393 } 394 395 /* Characters considered whitespace in strsep calls. */ 396 #define WHITESPACE " \t\r\n" 397 #define QUOTE "\"" 398 399 /* return next token in configuration line */ 400 static char * 401 strdelim_internal(char **s, int split_equals) 402 { 403 char *old; 404 int wspace = 0; 405 406 if (*s == NULL) 407 return NULL; 408 409 old = *s; 410 411 *s = strpbrk(*s, 412 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 413 if (*s == NULL) 414 return (old); 415 416 if (*s[0] == '\"') { 417 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 418 /* Find matching quote */ 419 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 420 return (NULL); /* no matching quote */ 421 } else { 422 *s[0] = '\0'; 423 *s += strspn(*s + 1, WHITESPACE) + 1; 424 return (old); 425 } 426 } 427 428 /* Allow only one '=' to be skipped */ 429 if (split_equals && *s[0] == '=') 430 wspace = 1; 431 *s[0] = '\0'; 432 433 /* Skip any extra whitespace after first token */ 434 *s += strspn(*s + 1, WHITESPACE) + 1; 435 if (split_equals && *s[0] == '=' && !wspace) 436 *s += strspn(*s + 1, WHITESPACE) + 1; 437 438 return (old); 439 } 440 441 /* 442 * Return next token in configuration line; splts on whitespace or a 443 * single '=' character. 444 */ 445 char * 446 strdelim(char **s) 447 { 448 return strdelim_internal(s, 1); 449 } 450 451 /* 452 * Return next token in configuration line; splts on whitespace only. 453 */ 454 char * 455 strdelimw(char **s) 456 { 457 return strdelim_internal(s, 0); 458 } 459 460 struct passwd * 461 pwcopy(struct passwd *pw) 462 { 463 struct passwd *copy = xcalloc(1, sizeof(*copy)); 464 465 copy->pw_name = xstrdup(pw->pw_name); 466 copy->pw_passwd = xstrdup(pw->pw_passwd); 467 copy->pw_gecos = xstrdup(pw->pw_gecos); 468 copy->pw_uid = pw->pw_uid; 469 copy->pw_gid = pw->pw_gid; 470 copy->pw_expire = pw->pw_expire; 471 copy->pw_change = pw->pw_change; 472 copy->pw_class = xstrdup(pw->pw_class); 473 copy->pw_dir = xstrdup(pw->pw_dir); 474 copy->pw_shell = xstrdup(pw->pw_shell); 475 return copy; 476 } 477 478 /* 479 * Convert ASCII string to TCP/IP port number. 480 * Port must be >=0 and <=65535. 481 * Return -1 if invalid. 482 */ 483 int 484 a2port(const char *s) 485 { 486 struct servent *se; 487 long long port; 488 const char *errstr; 489 490 port = strtonum(s, 0, 65535, &errstr); 491 if (errstr == NULL) 492 return (int)port; 493 if ((se = getservbyname(s, "tcp")) != NULL) 494 return ntohs(se->s_port); 495 return -1; 496 } 497 498 int 499 a2tun(const char *s, int *remote) 500 { 501 const char *errstr = NULL; 502 char *sp, *ep; 503 int tun; 504 505 if (remote != NULL) { 506 *remote = SSH_TUNID_ANY; 507 sp = xstrdup(s); 508 if ((ep = strchr(sp, ':')) == NULL) { 509 free(sp); 510 return (a2tun(s, NULL)); 511 } 512 ep[0] = '\0'; ep++; 513 *remote = a2tun(ep, NULL); 514 tun = a2tun(sp, NULL); 515 free(sp); 516 return (*remote == SSH_TUNID_ERR ? *remote : tun); 517 } 518 519 if (strcasecmp(s, "any") == 0) 520 return (SSH_TUNID_ANY); 521 522 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 523 if (errstr != NULL) 524 return (SSH_TUNID_ERR); 525 526 return (tun); 527 } 528 529 #define SECONDS 1 530 #define MINUTES (SECONDS * 60) 531 #define HOURS (MINUTES * 60) 532 #define DAYS (HOURS * 24) 533 #define WEEKS (DAYS * 7) 534 535 static char * 536 scandigits(char *s) 537 { 538 while (isdigit((unsigned char)*s)) 539 s++; 540 return s; 541 } 542 543 /* 544 * Convert a time string into seconds; format is 545 * a sequence of: 546 * time[qualifier] 547 * 548 * Valid time qualifiers are: 549 * <none> seconds 550 * s|S seconds 551 * m|M minutes 552 * h|H hours 553 * d|D days 554 * w|W weeks 555 * 556 * Examples: 557 * 90m 90 minutes 558 * 1h30m 90 minutes 559 * 2d 2 days 560 * 1w 1 week 561 * 562 * Return -1 if time string is invalid. 563 */ 564 int 565 convtime(const char *s) 566 { 567 int secs, total = 0, multiplier; 568 char *p, *os, *np, c = 0; 569 const char *errstr; 570 571 if (s == NULL || *s == '\0') 572 return -1; 573 p = os = strdup(s); /* deal with const */ 574 if (os == NULL) 575 return -1; 576 577 while (*p) { 578 np = scandigits(p); 579 if (np) { 580 c = *np; 581 *np = '\0'; 582 } 583 secs = (int)strtonum(p, 0, INT_MAX, &errstr); 584 if (errstr) 585 goto fail; 586 *np = c; 587 588 multiplier = 1; 589 switch (c) { 590 case '\0': 591 np--; /* back up */ 592 break; 593 case 's': 594 case 'S': 595 break; 596 case 'm': 597 case 'M': 598 multiplier = MINUTES; 599 break; 600 case 'h': 601 case 'H': 602 multiplier = HOURS; 603 break; 604 case 'd': 605 case 'D': 606 multiplier = DAYS; 607 break; 608 case 'w': 609 case 'W': 610 multiplier = WEEKS; 611 break; 612 default: 613 goto fail; 614 } 615 if (secs > INT_MAX / multiplier) 616 goto fail; 617 secs *= multiplier; 618 if (total > INT_MAX - secs) 619 goto fail; 620 total += secs; 621 if (total < 0) 622 goto fail; 623 p = ++np; 624 } 625 free(os); 626 return total; 627 fail: 628 free(os); 629 return -1; 630 } 631 632 #define TF_BUFS 8 633 #define TF_LEN 9 634 635 const char * 636 fmt_timeframe(time_t t) 637 { 638 char *buf; 639 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 640 static int idx = 0; 641 unsigned int sec, min, hrs, day; 642 unsigned long long week; 643 644 buf = tfbuf[idx++]; 645 if (idx == TF_BUFS) 646 idx = 0; 647 648 week = t; 649 650 sec = week % 60; 651 week /= 60; 652 min = week % 60; 653 week /= 60; 654 hrs = week % 24; 655 week /= 24; 656 day = week % 7; 657 week /= 7; 658 659 if (week > 0) 660 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 661 else if (day > 0) 662 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 663 else 664 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 665 666 return (buf); 667 } 668 669 /* 670 * Returns a standardized host+port identifier string. 671 * Caller must free returned string. 672 */ 673 char * 674 put_host_port(const char *host, u_short port) 675 { 676 char *hoststr; 677 678 if (port == 0 || port == SSH_DEFAULT_PORT) 679 return(xstrdup(host)); 680 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 681 fatal("put_host_port: asprintf: %s", strerror(errno)); 682 debug3("put_host_port: %s", hoststr); 683 return hoststr; 684 } 685 686 /* 687 * Search for next delimiter between hostnames/addresses and ports. 688 * Argument may be modified (for termination). 689 * Returns *cp if parsing succeeds. 690 * *cp is set to the start of the next field, if one was found. 691 * The delimiter char, if present, is stored in delim. 692 * If this is the last field, *cp is set to NULL. 693 */ 694 char * 695 hpdelim2(char **cp, char *delim) 696 { 697 char *s, *old; 698 699 if (cp == NULL || *cp == NULL) 700 return NULL; 701 702 old = s = *cp; 703 if (*s == '[') { 704 if ((s = strchr(s, ']')) == NULL) 705 return NULL; 706 else 707 s++; 708 } else if ((s = strpbrk(s, ":/")) == NULL) 709 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 710 711 switch (*s) { 712 case '\0': 713 *cp = NULL; /* no more fields*/ 714 break; 715 716 case ':': 717 case '/': 718 if (delim != NULL) 719 *delim = *s; 720 *s = '\0'; /* terminate */ 721 *cp = s + 1; 722 break; 723 724 default: 725 return NULL; 726 } 727 728 return old; 729 } 730 731 /* The common case: only accept colon as delimiter. */ 732 char * 733 hpdelim(char **cp) 734 { 735 char *r, delim = '\0'; 736 737 r = hpdelim2(cp, &delim); 738 if (delim == '/') 739 return NULL; 740 return r; 741 } 742 743 char * 744 cleanhostname(char *host) 745 { 746 if (*host == '[' && host[strlen(host) - 1] == ']') { 747 host[strlen(host) - 1] = '\0'; 748 return (host + 1); 749 } else 750 return host; 751 } 752 753 char * 754 colon(char *cp) 755 { 756 int flag = 0; 757 758 if (*cp == ':') /* Leading colon is part of file name. */ 759 return NULL; 760 if (*cp == '[') 761 flag = 1; 762 763 for (; *cp; ++cp) { 764 if (*cp == '@' && *(cp+1) == '[') 765 flag = 1; 766 if (*cp == ']' && *(cp+1) == ':' && flag) 767 return (cp+1); 768 if (*cp == ':' && !flag) 769 return (cp); 770 if (*cp == '/') 771 return NULL; 772 } 773 return NULL; 774 } 775 776 /* 777 * Parse a [user@]host:[path] string. 778 * Caller must free returned user, host and path. 779 * Any of the pointer return arguments may be NULL (useful for syntax checking). 780 * If user was not specified then *userp will be set to NULL. 781 * If host was not specified then *hostp will be set to NULL. 782 * If path was not specified then *pathp will be set to ".". 783 * Returns 0 on success, -1 on failure. 784 */ 785 int 786 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 787 { 788 char *user = NULL, *host = NULL, *path = NULL; 789 char *sdup, *tmp; 790 int ret = -1; 791 792 if (userp != NULL) 793 *userp = NULL; 794 if (hostp != NULL) 795 *hostp = NULL; 796 if (pathp != NULL) 797 *pathp = NULL; 798 799 sdup = xstrdup(s); 800 801 /* Check for remote syntax: [user@]host:[path] */ 802 if ((tmp = colon(sdup)) == NULL) 803 goto out; 804 805 /* Extract optional path */ 806 *tmp++ = '\0'; 807 if (*tmp == '\0') 808 tmp = "."; 809 path = xstrdup(tmp); 810 811 /* Extract optional user and mandatory host */ 812 tmp = strrchr(sdup, '@'); 813 if (tmp != NULL) { 814 *tmp++ = '\0'; 815 host = xstrdup(cleanhostname(tmp)); 816 if (*sdup != '\0') 817 user = xstrdup(sdup); 818 } else { 819 host = xstrdup(cleanhostname(sdup)); 820 user = NULL; 821 } 822 823 /* Success */ 824 if (userp != NULL) { 825 *userp = user; 826 user = NULL; 827 } 828 if (hostp != NULL) { 829 *hostp = host; 830 host = NULL; 831 } 832 if (pathp != NULL) { 833 *pathp = path; 834 path = NULL; 835 } 836 ret = 0; 837 out: 838 free(sdup); 839 free(user); 840 free(host); 841 free(path); 842 return ret; 843 } 844 845 /* 846 * Parse a [user@]host[:port] string. 847 * Caller must free returned user and host. 848 * Any of the pointer return arguments may be NULL (useful for syntax checking). 849 * If user was not specified then *userp will be set to NULL. 850 * If port was not specified then *portp will be -1. 851 * Returns 0 on success, -1 on failure. 852 */ 853 int 854 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 855 { 856 char *sdup, *cp, *tmp; 857 char *user = NULL, *host = NULL; 858 int port = -1, ret = -1; 859 860 if (userp != NULL) 861 *userp = NULL; 862 if (hostp != NULL) 863 *hostp = NULL; 864 if (portp != NULL) 865 *portp = -1; 866 867 if ((sdup = tmp = strdup(s)) == NULL) 868 return -1; 869 /* Extract optional username */ 870 if ((cp = strrchr(tmp, '@')) != NULL) { 871 *cp = '\0'; 872 if (*tmp == '\0') 873 goto out; 874 if ((user = strdup(tmp)) == NULL) 875 goto out; 876 tmp = cp + 1; 877 } 878 /* Extract mandatory hostname */ 879 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 880 goto out; 881 host = xstrdup(cleanhostname(cp)); 882 /* Convert and verify optional port */ 883 if (tmp != NULL && *tmp != '\0') { 884 if ((port = a2port(tmp)) <= 0) 885 goto out; 886 } 887 /* Success */ 888 if (userp != NULL) { 889 *userp = user; 890 user = NULL; 891 } 892 if (hostp != NULL) { 893 *hostp = host; 894 host = NULL; 895 } 896 if (portp != NULL) 897 *portp = port; 898 ret = 0; 899 out: 900 free(sdup); 901 free(user); 902 free(host); 903 return ret; 904 } 905 906 /* 907 * Converts a two-byte hex string to decimal. 908 * Returns the decimal value or -1 for invalid input. 909 */ 910 static int 911 hexchar(const char *s) 912 { 913 unsigned char result[2]; 914 int i; 915 916 for (i = 0; i < 2; i++) { 917 if (s[i] >= '0' && s[i] <= '9') 918 result[i] = (unsigned char)(s[i] - '0'); 919 else if (s[i] >= 'a' && s[i] <= 'f') 920 result[i] = (unsigned char)(s[i] - 'a') + 10; 921 else if (s[i] >= 'A' && s[i] <= 'F') 922 result[i] = (unsigned char)(s[i] - 'A') + 10; 923 else 924 return -1; 925 } 926 return (result[0] << 4) | result[1]; 927 } 928 929 /* 930 * Decode an url-encoded string. 931 * Returns a newly allocated string on success or NULL on failure. 932 */ 933 static char * 934 urldecode(const char *src) 935 { 936 char *ret, *dst; 937 int ch; 938 size_t srclen; 939 940 if ((srclen = strlen(src)) >= SIZE_MAX) 941 fatal_f("input too large"); 942 ret = xmalloc(srclen + 1); 943 for (dst = ret; *src != '\0'; src++) { 944 switch (*src) { 945 case '+': 946 *dst++ = ' '; 947 break; 948 case '%': 949 if (!isxdigit((unsigned char)src[1]) || 950 !isxdigit((unsigned char)src[2]) || 951 (ch = hexchar(src + 1)) == -1) { 952 free(ret); 953 return NULL; 954 } 955 *dst++ = ch; 956 src += 2; 957 break; 958 default: 959 *dst++ = *src; 960 break; 961 } 962 } 963 *dst = '\0'; 964 965 return ret; 966 } 967 968 /* 969 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 970 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 971 * Either user or path may be url-encoded (but not host or port). 972 * Caller must free returned user, host and path. 973 * Any of the pointer return arguments may be NULL (useful for syntax checking) 974 * but the scheme must always be specified. 975 * If user was not specified then *userp will be set to NULL. 976 * If port was not specified then *portp will be -1. 977 * If path was not specified then *pathp will be set to NULL. 978 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 979 */ 980 int 981 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 982 int *portp, char **pathp) 983 { 984 char *uridup, *cp, *tmp, ch; 985 char *user = NULL, *host = NULL, *path = NULL; 986 int port = -1, ret = -1; 987 size_t len; 988 989 len = strlen(scheme); 990 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 991 return 1; 992 uri += len + 3; 993 994 if (userp != NULL) 995 *userp = NULL; 996 if (hostp != NULL) 997 *hostp = NULL; 998 if (portp != NULL) 999 *portp = -1; 1000 if (pathp != NULL) 1001 *pathp = NULL; 1002 1003 uridup = tmp = xstrdup(uri); 1004 1005 /* Extract optional ssh-info (username + connection params) */ 1006 if ((cp = strchr(tmp, '@')) != NULL) { 1007 char *delim; 1008 1009 *cp = '\0'; 1010 /* Extract username and connection params */ 1011 if ((delim = strchr(tmp, ';')) != NULL) { 1012 /* Just ignore connection params for now */ 1013 *delim = '\0'; 1014 } 1015 if (*tmp == '\0') { 1016 /* Empty username */ 1017 goto out; 1018 } 1019 if ((user = urldecode(tmp)) == NULL) 1020 goto out; 1021 tmp = cp + 1; 1022 } 1023 1024 /* Extract mandatory hostname */ 1025 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 1026 goto out; 1027 host = xstrdup(cleanhostname(cp)); 1028 if (!valid_domain(host, 0, NULL)) 1029 goto out; 1030 1031 if (tmp != NULL && *tmp != '\0') { 1032 if (ch == ':') { 1033 /* Convert and verify port. */ 1034 if ((cp = strchr(tmp, '/')) != NULL) 1035 *cp = '\0'; 1036 if ((port = a2port(tmp)) <= 0) 1037 goto out; 1038 tmp = cp ? cp + 1 : NULL; 1039 } 1040 if (tmp != NULL && *tmp != '\0') { 1041 /* Extract optional path */ 1042 if ((path = urldecode(tmp)) == NULL) 1043 goto out; 1044 } 1045 } 1046 1047 /* Success */ 1048 if (userp != NULL) { 1049 *userp = user; 1050 user = NULL; 1051 } 1052 if (hostp != NULL) { 1053 *hostp = host; 1054 host = NULL; 1055 } 1056 if (portp != NULL) 1057 *portp = port; 1058 if (pathp != NULL) { 1059 *pathp = path; 1060 path = NULL; 1061 } 1062 ret = 0; 1063 out: 1064 free(uridup); 1065 free(user); 1066 free(host); 1067 free(path); 1068 return ret; 1069 } 1070 1071 /* function to assist building execv() arguments */ 1072 void 1073 addargs(arglist *args, char *fmt, ...) 1074 { 1075 va_list ap; 1076 char *cp; 1077 u_int nalloc; 1078 int r; 1079 1080 va_start(ap, fmt); 1081 r = vasprintf(&cp, fmt, ap); 1082 va_end(ap); 1083 if (r == -1) 1084 fatal_f("argument too long"); 1085 1086 nalloc = args->nalloc; 1087 if (args->list == NULL) { 1088 nalloc = 32; 1089 args->num = 0; 1090 } else if (args->num > (256 * 1024)) 1091 fatal_f("too many arguments"); 1092 else if (args->num >= args->nalloc) 1093 fatal_f("arglist corrupt"); 1094 else if (args->num+2 >= nalloc) 1095 nalloc *= 2; 1096 1097 args->list = xrecallocarray(args->list, args->nalloc, 1098 nalloc, sizeof(char *)); 1099 args->nalloc = nalloc; 1100 args->list[args->num++] = cp; 1101 args->list[args->num] = NULL; 1102 } 1103 1104 void 1105 replacearg(arglist *args, u_int which, char *fmt, ...) 1106 { 1107 va_list ap; 1108 char *cp; 1109 int r; 1110 1111 va_start(ap, fmt); 1112 r = vasprintf(&cp, fmt, ap); 1113 va_end(ap); 1114 if (r == -1) 1115 fatal_f("argument too long"); 1116 if (args->list == NULL || args->num >= args->nalloc) 1117 fatal_f("arglist corrupt"); 1118 1119 if (which >= args->num) 1120 fatal_f("tried to replace invalid arg %d >= %d", 1121 which, args->num); 1122 free(args->list[which]); 1123 args->list[which] = cp; 1124 } 1125 1126 void 1127 freeargs(arglist *args) 1128 { 1129 u_int i; 1130 1131 if (args == NULL) 1132 return; 1133 if (args->list != NULL && args->num < args->nalloc) { 1134 for (i = 0; i < args->num; i++) 1135 free(args->list[i]); 1136 free(args->list); 1137 } 1138 args->nalloc = args->num = 0; 1139 args->list = NULL; 1140 } 1141 1142 /* 1143 * Expands tildes in the file name. Returns data allocated by xmalloc. 1144 * Warning: this calls getpw*. 1145 */ 1146 int 1147 tilde_expand(const char *filename, uid_t uid, char **retp) 1148 { 1149 char *ocopy = NULL, *copy, *s = NULL; 1150 const char *path = NULL, *user = NULL; 1151 struct passwd *pw; 1152 size_t len; 1153 int ret = -1, r, slash; 1154 1155 *retp = NULL; 1156 if (*filename != '~') { 1157 *retp = xstrdup(filename); 1158 return 0; 1159 } 1160 ocopy = copy = xstrdup(filename + 1); 1161 1162 if (*copy == '\0') /* ~ */ 1163 path = NULL; 1164 else if (*copy == '/') { 1165 copy += strspn(copy, "/"); 1166 if (*copy == '\0') 1167 path = NULL; /* ~/ */ 1168 else 1169 path = copy; /* ~/path */ 1170 } else { 1171 user = copy; 1172 if ((path = strchr(copy, '/')) != NULL) { 1173 copy[path - copy] = '\0'; 1174 path++; 1175 path += strspn(path, "/"); 1176 if (*path == '\0') /* ~user/ */ 1177 path = NULL; 1178 /* else ~user/path */ 1179 } 1180 /* else ~user */ 1181 } 1182 if (user != NULL) { 1183 if ((pw = getpwnam(user)) == NULL) { 1184 error_f("No such user %s", user); 1185 goto out; 1186 } 1187 } else if ((pw = getpwuid(uid)) == NULL) { 1188 error_f("No such uid %ld", (long)uid); 1189 goto out; 1190 } 1191 1192 /* Make sure directory has a trailing '/' */ 1193 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1194 1195 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1196 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1197 error_f("xasprintf failed"); 1198 goto out; 1199 } 1200 if (r >= PATH_MAX) { 1201 error_f("Path too long"); 1202 goto out; 1203 } 1204 /* success */ 1205 ret = 0; 1206 *retp = s; 1207 s = NULL; 1208 out: 1209 free(s); 1210 free(ocopy); 1211 return ret; 1212 } 1213 1214 char * 1215 tilde_expand_filename(const char *filename, uid_t uid) 1216 { 1217 char *ret; 1218 1219 if (tilde_expand(filename, uid, &ret) != 0) 1220 cleanup_exit(255); 1221 return ret; 1222 } 1223 1224 /* 1225 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1226 * substitutions. A number of escapes may be specified as 1227 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1228 * by a NULL escape_char. Returns replaced string in memory allocated by 1229 * xmalloc which the caller must free. 1230 */ 1231 static char * 1232 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1233 const char *string, va_list ap) 1234 { 1235 #define EXPAND_MAX_KEYS 64 1236 u_int num_keys = 0, i; 1237 struct { 1238 const char *key; 1239 const char *repl; 1240 } keys[EXPAND_MAX_KEYS]; 1241 struct sshbuf *buf; 1242 int r, missingvar = 0; 1243 char *ret = NULL, *var, *varend, *val; 1244 size_t len; 1245 1246 if ((buf = sshbuf_new()) == NULL) 1247 fatal_f("sshbuf_new failed"); 1248 if (parseerror == NULL) 1249 fatal_f("null parseerror arg"); 1250 *parseerror = 1; 1251 1252 /* Gather keys if we're doing percent expansion. */ 1253 if (percent) { 1254 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1255 keys[num_keys].key = va_arg(ap, char *); 1256 if (keys[num_keys].key == NULL) 1257 break; 1258 keys[num_keys].repl = va_arg(ap, char *); 1259 if (keys[num_keys].repl == NULL) { 1260 fatal_f("NULL replacement for token %s", 1261 keys[num_keys].key); 1262 } 1263 } 1264 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1265 fatal_f("too many keys"); 1266 if (num_keys == 0) 1267 fatal_f("percent expansion without token list"); 1268 } 1269 1270 /* Expand string */ 1271 for (i = 0; *string != '\0'; string++) { 1272 /* Optionally process ${ENVIRONMENT} expansions. */ 1273 if (dollar && string[0] == '$' && string[1] == '{') { 1274 string += 2; /* skip over '${' */ 1275 if ((varend = strchr(string, '}')) == NULL) { 1276 error_f("environment variable '%s' missing " 1277 "closing '}'", string); 1278 goto out; 1279 } 1280 len = varend - string; 1281 if (len == 0) { 1282 error_f("zero-length environment variable"); 1283 goto out; 1284 } 1285 var = xmalloc(len + 1); 1286 (void)strlcpy(var, string, len + 1); 1287 if ((val = getenv(var)) == NULL) { 1288 error_f("env var ${%s} has no value", var); 1289 missingvar = 1; 1290 } else { 1291 debug3_f("expand ${%s} -> '%s'", var, val); 1292 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1293 fatal_fr(r, "sshbuf_put ${}"); 1294 } 1295 free(var); 1296 string += len; 1297 continue; 1298 } 1299 1300 /* 1301 * Process percent expansions if we have a list of TOKENs. 1302 * If we're not doing percent expansion everything just gets 1303 * appended here. 1304 */ 1305 if (*string != '%' || !percent) { 1306 append: 1307 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1308 fatal_fr(r, "sshbuf_put_u8 %%"); 1309 continue; 1310 } 1311 string++; 1312 /* %% case */ 1313 if (*string == '%') 1314 goto append; 1315 if (*string == '\0') { 1316 error_f("invalid format"); 1317 goto out; 1318 } 1319 for (i = 0; i < num_keys; i++) { 1320 if (strchr(keys[i].key, *string) != NULL) { 1321 if ((r = sshbuf_put(buf, keys[i].repl, 1322 strlen(keys[i].repl))) != 0) 1323 fatal_fr(r, "sshbuf_put %%-repl"); 1324 break; 1325 } 1326 } 1327 if (i >= num_keys) { 1328 error_f("unknown key %%%c", *string); 1329 goto out; 1330 } 1331 } 1332 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1333 fatal_f("sshbuf_dup_string failed"); 1334 *parseerror = 0; 1335 out: 1336 sshbuf_free(buf); 1337 return *parseerror ? NULL : ret; 1338 #undef EXPAND_MAX_KEYS 1339 } 1340 1341 /* 1342 * Expand only environment variables. 1343 * Note that although this function is variadic like the other similar 1344 * functions, any such arguments will be unused. 1345 */ 1346 1347 char * 1348 dollar_expand(int *parseerr, const char *string, ...) 1349 { 1350 char *ret; 1351 int err; 1352 va_list ap; 1353 1354 va_start(ap, string); 1355 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1356 va_end(ap); 1357 if (parseerr != NULL) 1358 *parseerr = err; 1359 return ret; 1360 } 1361 1362 /* 1363 * Returns expanded string or NULL if a specified environment variable is 1364 * not defined, or calls fatal if the string is invalid. 1365 */ 1366 char * 1367 percent_expand(const char *string, ...) 1368 { 1369 char *ret; 1370 int err; 1371 va_list ap; 1372 1373 va_start(ap, string); 1374 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1375 va_end(ap); 1376 if (err) 1377 fatal_f("failed"); 1378 return ret; 1379 } 1380 1381 /* 1382 * Returns expanded string or NULL if a specified environment variable is 1383 * not defined, or calls fatal if the string is invalid. 1384 */ 1385 char * 1386 percent_dollar_expand(const char *string, ...) 1387 { 1388 char *ret; 1389 int err; 1390 va_list ap; 1391 1392 va_start(ap, string); 1393 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1394 va_end(ap); 1395 if (err) 1396 fatal_f("failed"); 1397 return ret; 1398 } 1399 1400 int 1401 tun_open(int tun, int mode, char **ifname) 1402 { 1403 struct ifreq ifr; 1404 char name[100]; 1405 int fd = -1, sock; 1406 const char *tunbase = "tun"; 1407 1408 if (ifname != NULL) 1409 *ifname = NULL; 1410 1411 if (mode == SSH_TUNMODE_ETHERNET) 1412 tunbase = "tap"; 1413 1414 /* Open the tunnel device */ 1415 if (tun <= SSH_TUNID_MAX) { 1416 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1417 fd = open(name, O_RDWR); 1418 } else if (tun == SSH_TUNID_ANY) { 1419 for (tun = 100; tun >= 0; tun--) { 1420 snprintf(name, sizeof(name), "/dev/%s%d", 1421 tunbase, tun); 1422 if ((fd = open(name, O_RDWR)) >= 0) 1423 break; 1424 } 1425 } else { 1426 debug_f("invalid tunnel %u", tun); 1427 return -1; 1428 } 1429 1430 if (fd == -1) { 1431 debug_f("%s open: %s", name, strerror(errno)); 1432 return -1; 1433 } 1434 1435 debug_f("%s mode %d fd %d", name, mode, fd); 1436 1437 /* Bring interface up if it is not already */ 1438 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1439 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1440 goto failed; 1441 1442 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1443 debug_f("get interface %s flags: %s", ifr.ifr_name, 1444 strerror(errno)); 1445 goto failed; 1446 } 1447 1448 if (!(ifr.ifr_flags & IFF_UP)) { 1449 ifr.ifr_flags |= IFF_UP; 1450 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1451 debug_f("activate interface %s: %s", ifr.ifr_name, 1452 strerror(errno)); 1453 goto failed; 1454 } 1455 } 1456 1457 if (ifname != NULL) 1458 *ifname = xstrdup(ifr.ifr_name); 1459 1460 close(sock); 1461 return fd; 1462 1463 failed: 1464 if (fd >= 0) 1465 close(fd); 1466 if (sock >= 0) 1467 close(sock); 1468 return -1; 1469 } 1470 1471 void 1472 sanitise_stdfd(void) 1473 { 1474 int nullfd, dupfd; 1475 1476 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1477 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1478 strerror(errno)); 1479 exit(1); 1480 } 1481 while (++dupfd <= STDERR_FILENO) { 1482 /* Only populate closed fds. */ 1483 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1484 if (dup2(nullfd, dupfd) == -1) { 1485 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1486 exit(1); 1487 } 1488 } 1489 } 1490 if (nullfd > STDERR_FILENO) 1491 close(nullfd); 1492 } 1493 1494 char * 1495 tohex(const void *vp, size_t l) 1496 { 1497 const u_char *p = (const u_char *)vp; 1498 char b[3], *r; 1499 size_t i, hl; 1500 1501 if (l > 65536) 1502 return xstrdup("tohex: length > 65536"); 1503 1504 hl = l * 2 + 1; 1505 r = xcalloc(1, hl); 1506 for (i = 0; i < l; i++) { 1507 snprintf(b, sizeof(b), "%02x", p[i]); 1508 strlcat(r, b, hl); 1509 } 1510 return (r); 1511 } 1512 1513 /* 1514 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1515 * then the separator 'sep' will be prepended before the formatted arguments. 1516 * Extended strings are heap allocated. 1517 */ 1518 void 1519 xextendf(char **sp, const char *sep, const char *fmt, ...) 1520 { 1521 va_list ap; 1522 char *tmp1, *tmp2; 1523 1524 va_start(ap, fmt); 1525 xvasprintf(&tmp1, fmt, ap); 1526 va_end(ap); 1527 1528 if (*sp == NULL || **sp == '\0') { 1529 free(*sp); 1530 *sp = tmp1; 1531 return; 1532 } 1533 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1534 free(tmp1); 1535 free(*sp); 1536 *sp = tmp2; 1537 } 1538 1539 1540 u_int64_t 1541 get_u64(const void *vp) 1542 { 1543 const u_char *p = (const u_char *)vp; 1544 u_int64_t v; 1545 1546 v = (u_int64_t)p[0] << 56; 1547 v |= (u_int64_t)p[1] << 48; 1548 v |= (u_int64_t)p[2] << 40; 1549 v |= (u_int64_t)p[3] << 32; 1550 v |= (u_int64_t)p[4] << 24; 1551 v |= (u_int64_t)p[5] << 16; 1552 v |= (u_int64_t)p[6] << 8; 1553 v |= (u_int64_t)p[7]; 1554 1555 return (v); 1556 } 1557 1558 u_int32_t 1559 get_u32(const void *vp) 1560 { 1561 const u_char *p = (const u_char *)vp; 1562 u_int32_t v; 1563 1564 v = (u_int32_t)p[0] << 24; 1565 v |= (u_int32_t)p[1] << 16; 1566 v |= (u_int32_t)p[2] << 8; 1567 v |= (u_int32_t)p[3]; 1568 1569 return (v); 1570 } 1571 1572 u_int32_t 1573 get_u32_le(const void *vp) 1574 { 1575 const u_char *p = (const u_char *)vp; 1576 u_int32_t v; 1577 1578 v = (u_int32_t)p[0]; 1579 v |= (u_int32_t)p[1] << 8; 1580 v |= (u_int32_t)p[2] << 16; 1581 v |= (u_int32_t)p[3] << 24; 1582 1583 return (v); 1584 } 1585 1586 u_int16_t 1587 get_u16(const void *vp) 1588 { 1589 const u_char *p = (const u_char *)vp; 1590 u_int16_t v; 1591 1592 v = (u_int16_t)p[0] << 8; 1593 v |= (u_int16_t)p[1]; 1594 1595 return (v); 1596 } 1597 1598 void 1599 put_u64(void *vp, u_int64_t v) 1600 { 1601 u_char *p = (u_char *)vp; 1602 1603 p[0] = (u_char)(v >> 56) & 0xff; 1604 p[1] = (u_char)(v >> 48) & 0xff; 1605 p[2] = (u_char)(v >> 40) & 0xff; 1606 p[3] = (u_char)(v >> 32) & 0xff; 1607 p[4] = (u_char)(v >> 24) & 0xff; 1608 p[5] = (u_char)(v >> 16) & 0xff; 1609 p[6] = (u_char)(v >> 8) & 0xff; 1610 p[7] = (u_char)v & 0xff; 1611 } 1612 1613 void 1614 put_u32(void *vp, u_int32_t v) 1615 { 1616 u_char *p = (u_char *)vp; 1617 1618 p[0] = (u_char)(v >> 24) & 0xff; 1619 p[1] = (u_char)(v >> 16) & 0xff; 1620 p[2] = (u_char)(v >> 8) & 0xff; 1621 p[3] = (u_char)v & 0xff; 1622 } 1623 1624 void 1625 put_u32_le(void *vp, u_int32_t v) 1626 { 1627 u_char *p = (u_char *)vp; 1628 1629 p[0] = (u_char)v & 0xff; 1630 p[1] = (u_char)(v >> 8) & 0xff; 1631 p[2] = (u_char)(v >> 16) & 0xff; 1632 p[3] = (u_char)(v >> 24) & 0xff; 1633 } 1634 1635 void 1636 put_u16(void *vp, u_int16_t v) 1637 { 1638 u_char *p = (u_char *)vp; 1639 1640 p[0] = (u_char)(v >> 8) & 0xff; 1641 p[1] = (u_char)v & 0xff; 1642 } 1643 1644 void 1645 ms_subtract_diff(struct timeval *start, int *ms) 1646 { 1647 struct timeval diff, finish; 1648 1649 monotime_tv(&finish); 1650 timersub(&finish, start, &diff); 1651 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1652 } 1653 1654 void 1655 ms_to_timespec(struct timespec *ts, int ms) 1656 { 1657 if (ms < 0) 1658 ms = 0; 1659 ts->tv_sec = ms / 1000; 1660 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1661 } 1662 1663 void 1664 monotime_ts(struct timespec *ts) 1665 { 1666 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1667 fatal("clock_gettime: %s", strerror(errno)); 1668 } 1669 1670 void 1671 monotime_tv(struct timeval *tv) 1672 { 1673 struct timespec ts; 1674 1675 monotime_ts(&ts); 1676 tv->tv_sec = ts.tv_sec; 1677 tv->tv_usec = ts.tv_nsec / 1000; 1678 } 1679 1680 time_t 1681 monotime(void) 1682 { 1683 struct timespec ts; 1684 1685 monotime_ts(&ts); 1686 return (ts.tv_sec); 1687 } 1688 1689 double 1690 monotime_double(void) 1691 { 1692 struct timespec ts; 1693 1694 monotime_ts(&ts); 1695 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1696 } 1697 1698 void 1699 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1700 { 1701 bw->buflen = buflen; 1702 bw->rate = kbps; 1703 bw->thresh = buflen; 1704 bw->lamt = 0; 1705 timerclear(&bw->bwstart); 1706 timerclear(&bw->bwend); 1707 } 1708 1709 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1710 void 1711 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1712 { 1713 u_int64_t waitlen; 1714 struct timespec ts, rm; 1715 1716 bw->lamt += read_len; 1717 if (!timerisset(&bw->bwstart)) { 1718 monotime_tv(&bw->bwstart); 1719 return; 1720 } 1721 if (bw->lamt < bw->thresh) 1722 return; 1723 1724 monotime_tv(&bw->bwend); 1725 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1726 if (!timerisset(&bw->bwend)) 1727 return; 1728 1729 bw->lamt *= 8; 1730 waitlen = (double)1000000L * bw->lamt / bw->rate; 1731 1732 bw->bwstart.tv_sec = waitlen / 1000000L; 1733 bw->bwstart.tv_usec = waitlen % 1000000L; 1734 1735 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1736 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1737 1738 /* Adjust the wait time */ 1739 if (bw->bwend.tv_sec) { 1740 bw->thresh /= 2; 1741 if (bw->thresh < bw->buflen / 4) 1742 bw->thresh = bw->buflen / 4; 1743 } else if (bw->bwend.tv_usec < 10000) { 1744 bw->thresh *= 2; 1745 if (bw->thresh > bw->buflen * 8) 1746 bw->thresh = bw->buflen * 8; 1747 } 1748 1749 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1750 while (nanosleep(&ts, &rm) == -1) { 1751 if (errno != EINTR) 1752 break; 1753 ts = rm; 1754 } 1755 } 1756 1757 bw->lamt = 0; 1758 monotime_tv(&bw->bwstart); 1759 } 1760 1761 /* Make a template filename for mk[sd]temp() */ 1762 void 1763 mktemp_proto(char *s, size_t len) 1764 { 1765 const char *tmpdir; 1766 int r; 1767 1768 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1769 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1770 if (r > 0 && (size_t)r < len) 1771 return; 1772 } 1773 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1774 if (r < 0 || (size_t)r >= len) 1775 fatal_f("template string too short"); 1776 } 1777 1778 static const struct { 1779 const char *name; 1780 int value; 1781 } ipqos[] = { 1782 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1783 { "af11", IPTOS_DSCP_AF11 }, 1784 { "af12", IPTOS_DSCP_AF12 }, 1785 { "af13", IPTOS_DSCP_AF13 }, 1786 { "af21", IPTOS_DSCP_AF21 }, 1787 { "af22", IPTOS_DSCP_AF22 }, 1788 { "af23", IPTOS_DSCP_AF23 }, 1789 { "af31", IPTOS_DSCP_AF31 }, 1790 { "af32", IPTOS_DSCP_AF32 }, 1791 { "af33", IPTOS_DSCP_AF33 }, 1792 { "af41", IPTOS_DSCP_AF41 }, 1793 { "af42", IPTOS_DSCP_AF42 }, 1794 { "af43", IPTOS_DSCP_AF43 }, 1795 { "cs0", IPTOS_DSCP_CS0 }, 1796 { "cs1", IPTOS_DSCP_CS1 }, 1797 { "cs2", IPTOS_DSCP_CS2 }, 1798 { "cs3", IPTOS_DSCP_CS3 }, 1799 { "cs4", IPTOS_DSCP_CS4 }, 1800 { "cs5", IPTOS_DSCP_CS5 }, 1801 { "cs6", IPTOS_DSCP_CS6 }, 1802 { "cs7", IPTOS_DSCP_CS7 }, 1803 { "ef", IPTOS_DSCP_EF }, 1804 { "le", IPTOS_DSCP_LE }, 1805 { "lowdelay", IPTOS_LOWDELAY }, 1806 { "throughput", IPTOS_THROUGHPUT }, 1807 { "reliability", IPTOS_RELIABILITY }, 1808 { NULL, -1 } 1809 }; 1810 1811 int 1812 parse_ipqos(const char *cp) 1813 { 1814 const char *errstr; 1815 u_int i; 1816 int val; 1817 1818 if (cp == NULL) 1819 return -1; 1820 for (i = 0; ipqos[i].name != NULL; i++) { 1821 if (strcasecmp(cp, ipqos[i].name) == 0) 1822 return ipqos[i].value; 1823 } 1824 /* Try parsing as an integer */ 1825 val = (int)strtonum(cp, 0, 255, &errstr); 1826 if (errstr) 1827 return -1; 1828 return val; 1829 } 1830 1831 const char * 1832 iptos2str(int iptos) 1833 { 1834 int i; 1835 static char iptos_str[sizeof "0xff"]; 1836 1837 for (i = 0; ipqos[i].name != NULL; i++) { 1838 if (ipqos[i].value == iptos) 1839 return ipqos[i].name; 1840 } 1841 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1842 return iptos_str; 1843 } 1844 1845 void 1846 lowercase(char *s) 1847 { 1848 for (; *s; s++) 1849 *s = tolower((u_char)*s); 1850 } 1851 1852 int 1853 unix_listener(const char *path, int backlog, int unlink_first) 1854 { 1855 struct sockaddr_un sunaddr; 1856 int saved_errno, sock; 1857 1858 memset(&sunaddr, 0, sizeof(sunaddr)); 1859 sunaddr.sun_family = AF_UNIX; 1860 if (strlcpy(sunaddr.sun_path, path, 1861 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1862 error_f("path \"%s\" too long for Unix domain socket", path); 1863 errno = ENAMETOOLONG; 1864 return -1; 1865 } 1866 1867 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1868 if (sock == -1) { 1869 saved_errno = errno; 1870 error_f("socket: %.100s", strerror(errno)); 1871 errno = saved_errno; 1872 return -1; 1873 } 1874 if (unlink_first == 1) { 1875 if (unlink(path) != 0 && errno != ENOENT) 1876 error("unlink(%s): %.100s", path, strerror(errno)); 1877 } 1878 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1879 saved_errno = errno; 1880 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1881 close(sock); 1882 errno = saved_errno; 1883 return -1; 1884 } 1885 if (listen(sock, backlog) == -1) { 1886 saved_errno = errno; 1887 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1888 close(sock); 1889 unlink(path); 1890 errno = saved_errno; 1891 return -1; 1892 } 1893 return sock; 1894 } 1895 1896 /* 1897 * Compares two strings that maybe be NULL. Returns non-zero if strings 1898 * are both NULL or are identical, returns zero otherwise. 1899 */ 1900 static int 1901 strcmp_maybe_null(const char *a, const char *b) 1902 { 1903 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1904 return 0; 1905 if (a != NULL && strcmp(a, b) != 0) 1906 return 0; 1907 return 1; 1908 } 1909 1910 /* 1911 * Compare two forwards, returning non-zero if they are identical or 1912 * zero otherwise. 1913 */ 1914 int 1915 forward_equals(const struct Forward *a, const struct Forward *b) 1916 { 1917 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1918 return 0; 1919 if (a->listen_port != b->listen_port) 1920 return 0; 1921 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1922 return 0; 1923 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1924 return 0; 1925 if (a->connect_port != b->connect_port) 1926 return 0; 1927 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1928 return 0; 1929 /* allocated_port and handle are not checked */ 1930 return 1; 1931 } 1932 1933 /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */ 1934 int 1935 permitopen_port(const char *p) 1936 { 1937 int port; 1938 1939 if (strcmp(p, "*") == 0) 1940 return FWD_PERMIT_ANY_PORT; 1941 if ((port = a2port(p)) > 0) 1942 return port; 1943 return -1; 1944 } 1945 1946 /* returns 1 if process is already daemonized, 0 otherwise */ 1947 int 1948 daemonized(void) 1949 { 1950 int fd; 1951 1952 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1953 close(fd); 1954 return 0; /* have controlling terminal */ 1955 } 1956 if (getppid() != 1) 1957 return 0; /* parent is not init */ 1958 if (getsid(0) != getpid()) 1959 return 0; /* not session leader */ 1960 debug3("already daemonized"); 1961 return 1; 1962 } 1963 1964 /* 1965 * Splits 's' into an argument vector. Handles quoted string and basic 1966 * escape characters (\\, \", \'). Caller must free the argument vector 1967 * and its members. 1968 */ 1969 int 1970 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1971 { 1972 int r = SSH_ERR_INTERNAL_ERROR; 1973 int argc = 0, quote, i, j; 1974 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1975 1976 *argvp = NULL; 1977 *argcp = 0; 1978 1979 for (i = 0; s[i] != '\0'; i++) { 1980 /* Skip leading whitespace */ 1981 if (s[i] == ' ' || s[i] == '\t') 1982 continue; 1983 if (terminate_on_comment && s[i] == '#') 1984 break; 1985 /* Start of a token */ 1986 quote = 0; 1987 1988 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1989 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1990 argv[argc] = NULL; 1991 1992 /* Copy the token in, removing escapes */ 1993 for (j = 0; s[i] != '\0'; i++) { 1994 if (s[i] == '\\') { 1995 if (s[i + 1] == '\'' || 1996 s[i + 1] == '\"' || 1997 s[i + 1] == '\\' || 1998 (quote == 0 && s[i + 1] == ' ')) { 1999 i++; /* Skip '\' */ 2000 arg[j++] = s[i]; 2001 } else { 2002 /* Unrecognised escape */ 2003 arg[j++] = s[i]; 2004 } 2005 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 2006 break; /* done */ 2007 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 2008 quote = s[i]; /* quote start */ 2009 else if (quote != 0 && s[i] == quote) 2010 quote = 0; /* quote end */ 2011 else 2012 arg[j++] = s[i]; 2013 } 2014 if (s[i] == '\0') { 2015 if (quote != 0) { 2016 /* Ran out of string looking for close quote */ 2017 r = SSH_ERR_INVALID_FORMAT; 2018 goto out; 2019 } 2020 break; 2021 } 2022 } 2023 /* Success */ 2024 *argcp = argc; 2025 *argvp = argv; 2026 argc = 0; 2027 argv = NULL; 2028 r = 0; 2029 out: 2030 if (argc != 0 && argv != NULL) { 2031 for (i = 0; i < argc; i++) 2032 free(argv[i]); 2033 free(argv); 2034 } 2035 return r; 2036 } 2037 2038 /* 2039 * Reassemble an argument vector into a string, quoting and escaping as 2040 * necessary. Caller must free returned string. 2041 */ 2042 char * 2043 argv_assemble(int argc, char **argv) 2044 { 2045 int i, j, ws, r; 2046 char c, *ret; 2047 struct sshbuf *buf, *arg; 2048 2049 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2050 fatal_f("sshbuf_new failed"); 2051 2052 for (i = 0; i < argc; i++) { 2053 ws = 0; 2054 sshbuf_reset(arg); 2055 for (j = 0; argv[i][j] != '\0'; j++) { 2056 r = 0; 2057 c = argv[i][j]; 2058 switch (c) { 2059 case ' ': 2060 case '\t': 2061 ws = 1; 2062 r = sshbuf_put_u8(arg, c); 2063 break; 2064 case '\\': 2065 case '\'': 2066 case '"': 2067 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2068 break; 2069 /* FALLTHROUGH */ 2070 default: 2071 r = sshbuf_put_u8(arg, c); 2072 break; 2073 } 2074 if (r != 0) 2075 fatal_fr(r, "sshbuf_put_u8"); 2076 } 2077 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2078 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2079 (r = sshbuf_putb(buf, arg)) != 0 || 2080 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2081 fatal_fr(r, "assemble"); 2082 } 2083 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2084 fatal_f("malloc failed"); 2085 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2086 ret[sshbuf_len(buf)] = '\0'; 2087 sshbuf_free(buf); 2088 sshbuf_free(arg); 2089 return ret; 2090 } 2091 2092 char * 2093 argv_next(int *argcp, char ***argvp) 2094 { 2095 char *ret = (*argvp)[0]; 2096 2097 if (*argcp > 0 && ret != NULL) { 2098 (*argcp)--; 2099 (*argvp)++; 2100 } 2101 return ret; 2102 } 2103 2104 void 2105 argv_consume(int *argcp) 2106 { 2107 *argcp = 0; 2108 } 2109 2110 void 2111 argv_free(char **av, int ac) 2112 { 2113 int i; 2114 2115 if (av == NULL) 2116 return; 2117 for (i = 0; i < ac; i++) 2118 free(av[i]); 2119 free(av); 2120 } 2121 2122 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2123 int 2124 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2125 { 2126 int status; 2127 2128 while (waitpid(pid, &status, 0) == -1) { 2129 if (errno != EINTR) { 2130 error("%s waitpid: %s", tag, strerror(errno)); 2131 return -1; 2132 } 2133 } 2134 if (WIFSIGNALED(status)) { 2135 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2136 return -1; 2137 } else if (WEXITSTATUS(status) != 0) { 2138 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2139 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2140 return -1; 2141 } 2142 return 0; 2143 } 2144 2145 /* 2146 * Check a given path for security. This is defined as all components 2147 * of the path to the file must be owned by either the owner of 2148 * of the file or root and no directories must be group or world writable. 2149 * 2150 * XXX Should any specific check be done for sym links ? 2151 * 2152 * Takes a file name, its stat information (preferably from fstat() to 2153 * avoid races), the uid of the expected owner, their home directory and an 2154 * error buffer plus max size as arguments. 2155 * 2156 * Returns 0 on success and -1 on failure 2157 */ 2158 int 2159 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2160 uid_t uid, char *err, size_t errlen) 2161 { 2162 char buf[PATH_MAX], homedir[PATH_MAX]; 2163 char *cp; 2164 int comparehome = 0; 2165 struct stat st; 2166 2167 if (realpath(name, buf) == NULL) { 2168 snprintf(err, errlen, "realpath %s failed: %s", name, 2169 strerror(errno)); 2170 return -1; 2171 } 2172 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2173 comparehome = 1; 2174 2175 if (!S_ISREG(stp->st_mode)) { 2176 snprintf(err, errlen, "%s is not a regular file", buf); 2177 return -1; 2178 } 2179 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2180 (stp->st_mode & 022) != 0) { 2181 snprintf(err, errlen, "bad ownership or modes for file %s", 2182 buf); 2183 return -1; 2184 } 2185 2186 /* for each component of the canonical path, walking upwards */ 2187 for (;;) { 2188 if ((cp = dirname(buf)) == NULL) { 2189 snprintf(err, errlen, "dirname() failed"); 2190 return -1; 2191 } 2192 strlcpy(buf, cp, sizeof(buf)); 2193 2194 if (stat(buf, &st) == -1 || 2195 (st.st_uid != 0 && st.st_uid != uid) || 2196 (st.st_mode & 022) != 0) { 2197 snprintf(err, errlen, 2198 "bad ownership or modes for directory %s", buf); 2199 return -1; 2200 } 2201 2202 /* If are past the homedir then we can stop */ 2203 if (comparehome && strcmp(homedir, buf) == 0) 2204 break; 2205 2206 /* 2207 * dirname should always complete with a "/" path, 2208 * but we can be paranoid and check for "." too 2209 */ 2210 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2211 break; 2212 } 2213 return 0; 2214 } 2215 2216 /* 2217 * Version of safe_path() that accepts an open file descriptor to 2218 * avoid races. 2219 * 2220 * Returns 0 on success and -1 on failure 2221 */ 2222 int 2223 safe_path_fd(int fd, const char *file, struct passwd *pw, 2224 char *err, size_t errlen) 2225 { 2226 struct stat st; 2227 2228 /* check the open file to avoid races */ 2229 if (fstat(fd, &st) == -1) { 2230 snprintf(err, errlen, "cannot stat file %s: %s", 2231 file, strerror(errno)); 2232 return -1; 2233 } 2234 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2235 } 2236 2237 /* 2238 * Sets the value of the given variable in the environment. If the variable 2239 * already exists, its value is overridden. 2240 */ 2241 void 2242 child_set_env(char ***envp, u_int *envsizep, const char *name, 2243 const char *value) 2244 { 2245 char **env; 2246 u_int envsize; 2247 u_int i, namelen; 2248 2249 if (strchr(name, '=') != NULL) { 2250 error("Invalid environment variable \"%.100s\"", name); 2251 return; 2252 } 2253 2254 /* 2255 * Find the slot where the value should be stored. If the variable 2256 * already exists, we reuse the slot; otherwise we append a new slot 2257 * at the end of the array, expanding if necessary. 2258 */ 2259 env = *envp; 2260 namelen = strlen(name); 2261 for (i = 0; env[i]; i++) 2262 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2263 break; 2264 if (env[i]) { 2265 /* Reuse the slot. */ 2266 free(env[i]); 2267 } else { 2268 /* New variable. Expand if necessary. */ 2269 envsize = *envsizep; 2270 if (i >= envsize - 1) { 2271 if (envsize >= 1000) 2272 fatal("child_set_env: too many env vars"); 2273 envsize += 50; 2274 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2275 *envsizep = envsize; 2276 } 2277 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2278 env[i + 1] = NULL; 2279 } 2280 2281 /* Allocate space and format the variable in the appropriate slot. */ 2282 /* XXX xasprintf */ 2283 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2284 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2285 } 2286 2287 /* 2288 * Check and optionally lowercase a domain name, also removes trailing '.' 2289 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2290 */ 2291 int 2292 valid_domain(char *name, int makelower, const char **errstr) 2293 { 2294 size_t i, l = strlen(name); 2295 u_char c, last = '\0'; 2296 static char errbuf[256]; 2297 2298 if (l == 0) { 2299 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2300 goto bad; 2301 } 2302 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0]) && 2303 name[0] != '_' /* technically invalid, but common */) { 2304 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2305 "starts with invalid character", name); 2306 goto bad; 2307 } 2308 for (i = 0; i < l; i++) { 2309 c = tolower((u_char)name[i]); 2310 if (makelower) 2311 name[i] = (char)c; 2312 if (last == '.' && c == '.') { 2313 snprintf(errbuf, sizeof(errbuf), "domain name " 2314 "\"%.100s\" contains consecutive separators", name); 2315 goto bad; 2316 } 2317 if (c != '.' && c != '-' && !isalnum(c) && 2318 c != '_') /* technically invalid, but common */ { 2319 snprintf(errbuf, sizeof(errbuf), "domain name " 2320 "\"%.100s\" contains invalid characters", name); 2321 goto bad; 2322 } 2323 last = c; 2324 } 2325 if (name[l - 1] == '.') 2326 name[l - 1] = '\0'; 2327 if (errstr != NULL) 2328 *errstr = NULL; 2329 return 1; 2330 bad: 2331 if (errstr != NULL) 2332 *errstr = errbuf; 2333 return 0; 2334 } 2335 2336 /* 2337 * Verify that a environment variable name (not including initial '$') is 2338 * valid; consisting of one or more alphanumeric or underscore characters only. 2339 * Returns 1 on valid, 0 otherwise. 2340 */ 2341 int 2342 valid_env_name(const char *name) 2343 { 2344 const char *cp; 2345 2346 if (name[0] == '\0') 2347 return 0; 2348 for (cp = name; *cp != '\0'; cp++) { 2349 if (!isalnum((u_char)*cp) && *cp != '_') 2350 return 0; 2351 } 2352 return 1; 2353 } 2354 2355 const char * 2356 atoi_err(const char *nptr, int *val) 2357 { 2358 const char *errstr = NULL; 2359 2360 if (nptr == NULL || *nptr == '\0') 2361 return "missing"; 2362 *val = strtonum(nptr, 0, INT_MAX, &errstr); 2363 return errstr; 2364 } 2365 2366 int 2367 parse_absolute_time(const char *s, uint64_t *tp) 2368 { 2369 struct tm tm; 2370 time_t tt; 2371 char buf[32], *fmt; 2372 const char *cp; 2373 size_t l; 2374 int is_utc = 0; 2375 2376 *tp = 0; 2377 2378 l = strlen(s); 2379 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) { 2380 is_utc = 1; 2381 l--; 2382 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) { 2383 is_utc = 1; 2384 l -= 3; 2385 } 2386 /* 2387 * POSIX strptime says "The application shall ensure that there 2388 * is white-space or other non-alphanumeric characters between 2389 * any two conversion specifications" so arrange things this way. 2390 */ 2391 switch (l) { 2392 case 8: /* YYYYMMDD */ 2393 fmt = "%Y-%m-%d"; 2394 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2395 break; 2396 case 12: /* YYYYMMDDHHMM */ 2397 fmt = "%Y-%m-%dT%H:%M"; 2398 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2399 s, s + 4, s + 6, s + 8, s + 10); 2400 break; 2401 case 14: /* YYYYMMDDHHMMSS */ 2402 fmt = "%Y-%m-%dT%H:%M:%S"; 2403 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2404 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2405 break; 2406 default: 2407 return SSH_ERR_INVALID_FORMAT; 2408 } 2409 2410 memset(&tm, 0, sizeof(tm)); 2411 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0') 2412 return SSH_ERR_INVALID_FORMAT; 2413 if (is_utc) { 2414 if ((tt = timegm(&tm)) < 0) 2415 return SSH_ERR_INVALID_FORMAT; 2416 } else { 2417 if ((tt = mktime(&tm)) < 0) 2418 return SSH_ERR_INVALID_FORMAT; 2419 } 2420 /* success */ 2421 *tp = (uint64_t)tt; 2422 return 0; 2423 } 2424 2425 void 2426 format_absolute_time(uint64_t t, char *buf, size_t len) 2427 { 2428 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2429 struct tm tm; 2430 2431 localtime_r(&tt, &tm); 2432 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2433 } 2434 2435 /* 2436 * Parse a "pattern=interval" clause (e.g. a ChannelTimeout). 2437 * Returns 0 on success or non-zero on failure. 2438 * Caller must free *typep. 2439 */ 2440 int 2441 parse_pattern_interval(const char *s, char **typep, int *secsp) 2442 { 2443 char *cp, *sdup; 2444 int secs; 2445 2446 if (typep != NULL) 2447 *typep = NULL; 2448 if (secsp != NULL) 2449 *secsp = 0; 2450 if (s == NULL) 2451 return -1; 2452 sdup = xstrdup(s); 2453 2454 if ((cp = strchr(sdup, '=')) == NULL || cp == sdup) { 2455 free(sdup); 2456 return -1; 2457 } 2458 *cp++ = '\0'; 2459 if ((secs = convtime(cp)) < 0) { 2460 free(sdup); 2461 return -1; 2462 } 2463 /* success */ 2464 if (typep != NULL) 2465 *typep = xstrdup(sdup); 2466 if (secsp != NULL) 2467 *secsp = secs; 2468 free(sdup); 2469 return 0; 2470 } 2471 2472 /* check if path is absolute */ 2473 int 2474 path_absolute(const char *path) 2475 { 2476 return (*path == '/') ? 1 : 0; 2477 } 2478 2479 void 2480 skip_space(char **cpp) 2481 { 2482 char *cp; 2483 2484 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2485 ; 2486 *cpp = cp; 2487 } 2488 2489 /* authorized_key-style options parsing helpers */ 2490 2491 /* 2492 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2493 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2494 * if negated option matches. 2495 * If the option or negated option matches, then *optsp is updated to 2496 * point to the first character after the option. 2497 */ 2498 int 2499 opt_flag(const char *opt, int allow_negate, const char **optsp) 2500 { 2501 size_t opt_len = strlen(opt); 2502 const char *opts = *optsp; 2503 int negate = 0; 2504 2505 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2506 opts += 3; 2507 negate = 1; 2508 } 2509 if (strncasecmp(opts, opt, opt_len) == 0) { 2510 *optsp = opts + opt_len; 2511 return negate ? 0 : 1; 2512 } 2513 return -1; 2514 } 2515 2516 char * 2517 opt_dequote(const char **sp, const char **errstrp) 2518 { 2519 const char *s = *sp; 2520 char *ret; 2521 size_t i; 2522 2523 *errstrp = NULL; 2524 if (*s != '"') { 2525 *errstrp = "missing start quote"; 2526 return NULL; 2527 } 2528 s++; 2529 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2530 *errstrp = "memory allocation failed"; 2531 return NULL; 2532 } 2533 for (i = 0; *s != '\0' && *s != '"';) { 2534 if (s[0] == '\\' && s[1] == '"') 2535 s++; 2536 ret[i++] = *s++; 2537 } 2538 if (*s == '\0') { 2539 *errstrp = "missing end quote"; 2540 free(ret); 2541 return NULL; 2542 } 2543 ret[i] = '\0'; 2544 s++; 2545 *sp = s; 2546 return ret; 2547 } 2548 2549 int 2550 opt_match(const char **opts, const char *term) 2551 { 2552 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2553 (*opts)[strlen(term)] == '=') { 2554 *opts += strlen(term) + 1; 2555 return 1; 2556 } 2557 return 0; 2558 } 2559 2560 void 2561 opt_array_append2(const char *file, const int line, const char *directive, 2562 char ***array, int **iarray, u_int *lp, const char *s, int i) 2563 { 2564 2565 if (*lp >= INT_MAX) 2566 fatal("%s line %d: Too many %s entries", file, line, directive); 2567 2568 if (iarray != NULL) { 2569 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2570 sizeof(**iarray)); 2571 (*iarray)[*lp] = i; 2572 } 2573 2574 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2575 (*array)[*lp] = xstrdup(s); 2576 (*lp)++; 2577 } 2578 2579 void 2580 opt_array_append(const char *file, const int line, const char *directive, 2581 char ***array, u_int *lp, const char *s) 2582 { 2583 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2584 } 2585 2586 void 2587 opt_array_free2(char **array, int **iarray, u_int l) 2588 { 2589 u_int i; 2590 2591 if (array == NULL || l == 0) 2592 return; 2593 for (i = 0; i < l; i++) 2594 free(array[i]); 2595 free(array); 2596 free(iarray); 2597 } 2598 2599 sshsig_t 2600 ssh_signal(int signum, sshsig_t handler) 2601 { 2602 struct sigaction sa, osa; 2603 2604 /* mask all other signals while in handler */ 2605 memset(&sa, 0, sizeof(sa)); 2606 sa.sa_handler = handler; 2607 sigfillset(&sa.sa_mask); 2608 if (signum != SIGALRM) 2609 sa.sa_flags = SA_RESTART; 2610 if (sigaction(signum, &sa, &osa) == -1) { 2611 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2612 return SIG_ERR; 2613 } 2614 return osa.sa_handler; 2615 } 2616 2617 int 2618 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2619 { 2620 int devnull, ret = 0; 2621 2622 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2623 error_f("open %s: %s", _PATH_DEVNULL, 2624 strerror(errno)); 2625 return -1; 2626 } 2627 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2628 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2629 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2630 error_f("dup2: %s", strerror(errno)); 2631 ret = -1; 2632 } 2633 if (devnull > STDERR_FILENO) 2634 close(devnull); 2635 return ret; 2636 } 2637 2638 /* 2639 * Runs command in a subprocess with a minimal environment. 2640 * Returns pid on success, 0 on failure. 2641 * The child stdout and stderr maybe captured, left attached or sent to 2642 * /dev/null depending on the contents of flags. 2643 * "tag" is prepended to log messages. 2644 * NB. "command" is only used for logging; the actual command executed is 2645 * av[0]. 2646 */ 2647 pid_t 2648 subprocess(const char *tag, const char *command, 2649 int ac, char **av, FILE **child, u_int flags, 2650 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2651 { 2652 FILE *f = NULL; 2653 struct stat st; 2654 int fd, devnull, p[2], i; 2655 pid_t pid; 2656 char *cp, errmsg[512]; 2657 u_int nenv = 0; 2658 char **env = NULL; 2659 2660 /* If dropping privs, then must specify user and restore function */ 2661 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2662 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2663 return 0; 2664 } 2665 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2666 error("%s: no user for current uid", tag); 2667 return 0; 2668 } 2669 if (child != NULL) 2670 *child = NULL; 2671 2672 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2673 tag, command, pw->pw_name, flags); 2674 2675 /* Check consistency */ 2676 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2677 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2678 error_f("inconsistent flags"); 2679 return 0; 2680 } 2681 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2682 error_f("inconsistent flags/output"); 2683 return 0; 2684 } 2685 2686 /* 2687 * If executing an explicit binary, then verify the it exists 2688 * and appears safe-ish to execute 2689 */ 2690 if (!path_absolute(av[0])) { 2691 error("%s path is not absolute", tag); 2692 return 0; 2693 } 2694 if (drop_privs != NULL) 2695 drop_privs(pw); 2696 if (stat(av[0], &st) == -1) { 2697 error("Could not stat %s \"%s\": %s", tag, 2698 av[0], strerror(errno)); 2699 goto restore_return; 2700 } 2701 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2702 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2703 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2704 goto restore_return; 2705 } 2706 /* Prepare to keep the child's stdout if requested */ 2707 if (pipe(p) == -1) { 2708 error("%s: pipe: %s", tag, strerror(errno)); 2709 restore_return: 2710 if (restore_privs != NULL) 2711 restore_privs(); 2712 return 0; 2713 } 2714 if (restore_privs != NULL) 2715 restore_privs(); 2716 2717 switch ((pid = fork())) { 2718 case -1: /* error */ 2719 error("%s: fork: %s", tag, strerror(errno)); 2720 close(p[0]); 2721 close(p[1]); 2722 return 0; 2723 case 0: /* child */ 2724 /* Prepare a minimal environment for the child. */ 2725 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2726 nenv = 5; 2727 env = xcalloc(sizeof(*env), nenv); 2728 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2729 child_set_env(&env, &nenv, "USER", pw->pw_name); 2730 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2731 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2732 if ((cp = getenv("LANG")) != NULL) 2733 child_set_env(&env, &nenv, "LANG", cp); 2734 } 2735 2736 for (i = 1; i < NSIG; i++) 2737 ssh_signal(i, SIG_DFL); 2738 2739 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2740 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2741 strerror(errno)); 2742 _exit(1); 2743 } 2744 if (dup2(devnull, STDIN_FILENO) == -1) { 2745 error("%s: dup2: %s", tag, strerror(errno)); 2746 _exit(1); 2747 } 2748 2749 /* Set up stdout as requested; leave stderr in place for now. */ 2750 fd = -1; 2751 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2752 fd = p[1]; 2753 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2754 fd = devnull; 2755 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2756 error("%s: dup2: %s", tag, strerror(errno)); 2757 _exit(1); 2758 } 2759 closefrom(STDERR_FILENO + 1); 2760 2761 if (geteuid() == 0 && 2762 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2763 error("%s: initgroups(%s, %u): %s", tag, 2764 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2765 _exit(1); 2766 } 2767 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2768 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2769 strerror(errno)); 2770 _exit(1); 2771 } 2772 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2773 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2774 strerror(errno)); 2775 _exit(1); 2776 } 2777 /* stdin is pointed to /dev/null at this point */ 2778 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2779 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2780 error("%s: dup2: %s", tag, strerror(errno)); 2781 _exit(1); 2782 } 2783 if (env != NULL) 2784 execve(av[0], av, env); 2785 else 2786 execv(av[0], av); 2787 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2788 command, strerror(errno)); 2789 _exit(127); 2790 default: /* parent */ 2791 break; 2792 } 2793 2794 close(p[1]); 2795 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2796 close(p[0]); 2797 else if ((f = fdopen(p[0], "r")) == NULL) { 2798 error("%s: fdopen: %s", tag, strerror(errno)); 2799 close(p[0]); 2800 /* Don't leave zombie child */ 2801 kill(pid, SIGTERM); 2802 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2803 ; 2804 return 0; 2805 } 2806 /* Success */ 2807 debug3_f("%s pid %ld", tag, (long)pid); 2808 if (child != NULL) 2809 *child = f; 2810 return pid; 2811 } 2812 2813 const char * 2814 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2815 { 2816 size_t i, envlen; 2817 2818 envlen = strlen(env); 2819 for (i = 0; i < nenvs; i++) { 2820 if (strncmp(envs[i], env, envlen) == 0 && 2821 envs[i][envlen] == '=') { 2822 return envs[i] + envlen + 1; 2823 } 2824 } 2825 return NULL; 2826 } 2827 2828 const char * 2829 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs) 2830 { 2831 char *name, *cp; 2832 const char *ret; 2833 2834 name = xstrdup(env); 2835 if ((cp = strchr(name, '=')) == NULL) { 2836 free(name); 2837 return NULL; /* not env=val */ 2838 } 2839 *cp = '\0'; 2840 ret = lookup_env_in_list(name, envs, nenvs); 2841 free(name); 2842 return ret; 2843 } 2844 2845 /* 2846 * Helpers for managing poll(2)/ppoll(2) timeouts 2847 * Will remember the earliest deadline and return it for use in poll/ppoll. 2848 */ 2849 2850 /* Initialise a poll/ppoll timeout with an indefinite deadline */ 2851 void 2852 ptimeout_init(struct timespec *pt) 2853 { 2854 /* 2855 * Deliberately invalid for ppoll(2). 2856 * Will be converted to NULL in ptimeout_get_tspec() later. 2857 */ 2858 pt->tv_sec = -1; 2859 pt->tv_nsec = 0; 2860 } 2861 2862 /* Specify a poll/ppoll deadline of at most 'sec' seconds */ 2863 void 2864 ptimeout_deadline_sec(struct timespec *pt, long sec) 2865 { 2866 if (pt->tv_sec == -1 || pt->tv_sec >= sec) { 2867 pt->tv_sec = sec; 2868 pt->tv_nsec = 0; 2869 } 2870 } 2871 2872 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */ 2873 static void 2874 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p) 2875 { 2876 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=)) 2877 *pt = *p; 2878 } 2879 2880 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */ 2881 void 2882 ptimeout_deadline_ms(struct timespec *pt, long ms) 2883 { 2884 struct timespec p; 2885 2886 p.tv_sec = ms / 1000; 2887 p.tv_nsec = (ms % 1000) * 1000000; 2888 ptimeout_deadline_tsp(pt, &p); 2889 } 2890 2891 /* Specify a poll/ppoll deadline at wall clock monotime 'when' (timespec) */ 2892 void 2893 ptimeout_deadline_monotime_tsp(struct timespec *pt, struct timespec *when) 2894 { 2895 struct timespec now, t; 2896 2897 monotime_ts(&now); 2898 2899 if (timespeccmp(&now, when, >=)) { 2900 /* 'when' is now or in the past. Timeout ASAP */ 2901 pt->tv_sec = 0; 2902 pt->tv_nsec = 0; 2903 } else { 2904 timespecsub(when, &now, &t); 2905 ptimeout_deadline_tsp(pt, &t); 2906 } 2907 } 2908 2909 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */ 2910 void 2911 ptimeout_deadline_monotime(struct timespec *pt, time_t when) 2912 { 2913 struct timespec t; 2914 2915 t.tv_sec = when; 2916 t.tv_nsec = 0; 2917 ptimeout_deadline_monotime_tsp(pt, &t); 2918 } 2919 2920 /* Get a poll(2) timeout value in milliseconds */ 2921 int 2922 ptimeout_get_ms(struct timespec *pt) 2923 { 2924 if (pt->tv_sec == -1) 2925 return -1; 2926 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000) 2927 return INT_MAX; 2928 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000); 2929 } 2930 2931 /* Get a ppoll(2) timeout value as a timespec pointer */ 2932 struct timespec * 2933 ptimeout_get_tsp(struct timespec *pt) 2934 { 2935 return pt->tv_sec == -1 ? NULL : pt; 2936 } 2937 2938 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */ 2939 int 2940 ptimeout_isset(struct timespec *pt) 2941 { 2942 return pt->tv_sec != -1; 2943 } 2944 2945 /* 2946 * Returns zero if the library at 'path' contains symbol 's', nonzero 2947 * otherwise. 2948 */ 2949 int 2950 lib_contains_symbol(const char *path, const char *s) 2951 { 2952 struct nlist nl[2]; 2953 int ret = -1, r; 2954 2955 memset(nl, 0, sizeof(nl)); 2956 nl[0].n_name = xstrdup(s); 2957 nl[1].n_name = NULL; 2958 if ((r = nlist(path, nl)) == -1) { 2959 error_f("nlist failed for %s", path); 2960 goto out; 2961 } 2962 if (r != 0 || nl[0].n_value == 0 || nl[0].n_type == 0) { 2963 error_f("library %s does not contain symbol %s", path, s); 2964 goto out; 2965 } 2966 /* success */ 2967 ret = 0; 2968 out: 2969 free(nl[0].n_name); 2970 return ret; 2971 } 2972 2973 int 2974 signal_is_crash(int sig) 2975 { 2976 switch (sig) { 2977 case SIGSEGV: 2978 case SIGBUS: 2979 case SIGTRAP: 2980 case SIGSYS: 2981 case SIGFPE: 2982 case SIGILL: 2983 case SIGABRT: 2984 return 1; 2985 } 2986 return 0; 2987 } 2988