1 /* $OpenBSD: misc.c,v 1.189 2023/10/12 03:36:32 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 /* set/unset filedescriptor to non-blocking */ 91 int 92 set_nonblock(int fd) 93 { 94 int val; 95 96 val = fcntl(fd, F_GETFL); 97 if (val == -1) { 98 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 99 return (-1); 100 } 101 if (val & O_NONBLOCK) { 102 debug3("fd %d is O_NONBLOCK", fd); 103 return (0); 104 } 105 debug2("fd %d setting O_NONBLOCK", fd); 106 val |= O_NONBLOCK; 107 if (fcntl(fd, F_SETFL, val) == -1) { 108 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 109 strerror(errno)); 110 return (-1); 111 } 112 return (0); 113 } 114 115 int 116 unset_nonblock(int fd) 117 { 118 int val; 119 120 val = fcntl(fd, F_GETFL); 121 if (val == -1) { 122 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 123 return (-1); 124 } 125 if (!(val & O_NONBLOCK)) { 126 debug3("fd %d is not O_NONBLOCK", fd); 127 return (0); 128 } 129 debug("fd %d clearing O_NONBLOCK", fd); 130 val &= ~O_NONBLOCK; 131 if (fcntl(fd, F_SETFL, val) == -1) { 132 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 133 fd, strerror(errno)); 134 return (-1); 135 } 136 return (0); 137 } 138 139 const char * 140 ssh_gai_strerror(int gaierr) 141 { 142 if (gaierr == EAI_SYSTEM && errno != 0) 143 return strerror(errno); 144 return gai_strerror(gaierr); 145 } 146 147 /* disable nagle on socket */ 148 void 149 set_nodelay(int fd) 150 { 151 int opt; 152 socklen_t optlen; 153 154 optlen = sizeof opt; 155 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 156 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 157 return; 158 } 159 if (opt == 1) { 160 debug2("fd %d is TCP_NODELAY", fd); 161 return; 162 } 163 opt = 1; 164 debug2("fd %d setting TCP_NODELAY", fd); 165 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 166 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 167 } 168 169 /* Allow local port reuse in TIME_WAIT */ 170 int 171 set_reuseaddr(int fd) 172 { 173 int on = 1; 174 175 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 176 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 177 return -1; 178 } 179 return 0; 180 } 181 182 /* Get/set routing domain */ 183 char * 184 get_rdomain(int fd) 185 { 186 int rtable; 187 char *ret; 188 socklen_t len = sizeof(rtable); 189 190 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 191 error("Failed to get routing domain for fd %d: %s", 192 fd, strerror(errno)); 193 return NULL; 194 } 195 xasprintf(&ret, "%d", rtable); 196 return ret; 197 } 198 199 int 200 set_rdomain(int fd, const char *name) 201 { 202 int rtable; 203 const char *errstr; 204 205 if (name == NULL) 206 return 0; /* default table */ 207 208 rtable = (int)strtonum(name, 0, 255, &errstr); 209 if (errstr != NULL) { 210 /* Shouldn't happen */ 211 error("Invalid routing domain \"%s\": %s", name, errstr); 212 return -1; 213 } 214 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 215 &rtable, sizeof(rtable)) == -1) { 216 error("Failed to set routing domain %d on fd %d: %s", 217 rtable, fd, strerror(errno)); 218 return -1; 219 } 220 return 0; 221 } 222 223 int 224 get_sock_af(int fd) 225 { 226 struct sockaddr_storage to; 227 socklen_t tolen = sizeof(to); 228 229 memset(&to, 0, sizeof(to)); 230 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 231 return -1; 232 return to.ss_family; 233 } 234 235 void 236 set_sock_tos(int fd, int tos) 237 { 238 int af; 239 240 switch ((af = get_sock_af(fd))) { 241 case -1: 242 /* assume not a socket */ 243 break; 244 case AF_INET: 245 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 246 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 247 &tos, sizeof(tos)) == -1) { 248 error("setsockopt socket %d IP_TOS %d: %s", 249 fd, tos, strerror(errno)); 250 } 251 break; 252 case AF_INET6: 253 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 254 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 255 &tos, sizeof(tos)) == -1) { 256 error("setsockopt socket %d IPV6_TCLASS %d: %s", 257 fd, tos, strerror(errno)); 258 } 259 break; 260 default: 261 debug2_f("unsupported socket family %d", af); 262 break; 263 } 264 } 265 266 /* 267 * Wait up to *timeoutp milliseconds for events on fd. Updates 268 * *timeoutp with time remaining. 269 * Returns 0 if fd ready or -1 on timeout or error (see errno). 270 */ 271 static int 272 waitfd(int fd, int *timeoutp, short events, volatile sig_atomic_t *stop) 273 { 274 struct pollfd pfd; 275 struct timespec timeout; 276 int oerrno, r; 277 sigset_t nsigset, osigset; 278 279 if (timeoutp && *timeoutp == -1) 280 timeoutp = NULL; 281 pfd.fd = fd; 282 pfd.events = events; 283 ptimeout_init(&timeout); 284 if (timeoutp != NULL) 285 ptimeout_deadline_ms(&timeout, *timeoutp); 286 if (stop != NULL) 287 sigfillset(&nsigset); 288 for (; timeoutp == NULL || *timeoutp >= 0;) { 289 if (stop != NULL) { 290 sigprocmask(SIG_BLOCK, &nsigset, &osigset); 291 if (*stop) { 292 sigprocmask(SIG_SETMASK, &osigset, NULL); 293 errno = EINTR; 294 return -1; 295 } 296 } 297 r = ppoll(&pfd, 1, ptimeout_get_tsp(&timeout), 298 stop != NULL ? &osigset : NULL); 299 oerrno = errno; 300 if (stop != NULL) 301 sigprocmask(SIG_SETMASK, &osigset, NULL); 302 if (timeoutp) 303 *timeoutp = ptimeout_get_ms(&timeout); 304 errno = oerrno; 305 if (r > 0) 306 return 0; 307 else if (r == -1 && errno != EAGAIN && errno != EINTR) 308 return -1; 309 else if (r == 0) 310 break; 311 } 312 /* timeout */ 313 errno = ETIMEDOUT; 314 return -1; 315 } 316 317 /* 318 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 319 * *timeoutp with time remaining. 320 * Returns 0 if fd ready or -1 on timeout or error (see errno). 321 */ 322 int 323 waitrfd(int fd, int *timeoutp, volatile sig_atomic_t *stop) { 324 return waitfd(fd, timeoutp, POLLIN, stop); 325 } 326 327 /* 328 * Attempt a non-blocking connect(2) to the specified address, waiting up to 329 * *timeoutp milliseconds for the connection to complete. If the timeout is 330 * <=0, then wait indefinitely. 331 * 332 * Returns 0 on success or -1 on failure. 333 */ 334 int 335 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 336 socklen_t addrlen, int *timeoutp) 337 { 338 int optval = 0; 339 socklen_t optlen = sizeof(optval); 340 341 /* No timeout: just do a blocking connect() */ 342 if (timeoutp == NULL || *timeoutp <= 0) 343 return connect(sockfd, serv_addr, addrlen); 344 345 set_nonblock(sockfd); 346 for (;;) { 347 if (connect(sockfd, serv_addr, addrlen) == 0) { 348 /* Succeeded already? */ 349 unset_nonblock(sockfd); 350 return 0; 351 } else if (errno == EINTR) 352 continue; 353 else if (errno != EINPROGRESS) 354 return -1; 355 break; 356 } 357 358 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT, NULL) == -1) 359 return -1; 360 361 /* Completed or failed */ 362 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 363 debug("getsockopt: %s", strerror(errno)); 364 return -1; 365 } 366 if (optval != 0) { 367 errno = optval; 368 return -1; 369 } 370 unset_nonblock(sockfd); 371 return 0; 372 } 373 374 /* Characters considered whitespace in strsep calls. */ 375 #define WHITESPACE " \t\r\n" 376 #define QUOTE "\"" 377 378 /* return next token in configuration line */ 379 static char * 380 strdelim_internal(char **s, int split_equals) 381 { 382 char *old; 383 int wspace = 0; 384 385 if (*s == NULL) 386 return NULL; 387 388 old = *s; 389 390 *s = strpbrk(*s, 391 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 392 if (*s == NULL) 393 return (old); 394 395 if (*s[0] == '\"') { 396 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 397 /* Find matching quote */ 398 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 399 return (NULL); /* no matching quote */ 400 } else { 401 *s[0] = '\0'; 402 *s += strspn(*s + 1, WHITESPACE) + 1; 403 return (old); 404 } 405 } 406 407 /* Allow only one '=' to be skipped */ 408 if (split_equals && *s[0] == '=') 409 wspace = 1; 410 *s[0] = '\0'; 411 412 /* Skip any extra whitespace after first token */ 413 *s += strspn(*s + 1, WHITESPACE) + 1; 414 if (split_equals && *s[0] == '=' && !wspace) 415 *s += strspn(*s + 1, WHITESPACE) + 1; 416 417 return (old); 418 } 419 420 /* 421 * Return next token in configuration line; splts on whitespace or a 422 * single '=' character. 423 */ 424 char * 425 strdelim(char **s) 426 { 427 return strdelim_internal(s, 1); 428 } 429 430 /* 431 * Return next token in configuration line; splts on whitespace only. 432 */ 433 char * 434 strdelimw(char **s) 435 { 436 return strdelim_internal(s, 0); 437 } 438 439 struct passwd * 440 pwcopy(struct passwd *pw) 441 { 442 struct passwd *copy = xcalloc(1, sizeof(*copy)); 443 444 copy->pw_name = xstrdup(pw->pw_name); 445 copy->pw_passwd = xstrdup(pw->pw_passwd); 446 copy->pw_gecos = xstrdup(pw->pw_gecos); 447 copy->pw_uid = pw->pw_uid; 448 copy->pw_gid = pw->pw_gid; 449 copy->pw_expire = pw->pw_expire; 450 copy->pw_change = pw->pw_change; 451 copy->pw_class = xstrdup(pw->pw_class); 452 copy->pw_dir = xstrdup(pw->pw_dir); 453 copy->pw_shell = xstrdup(pw->pw_shell); 454 return copy; 455 } 456 457 /* 458 * Convert ASCII string to TCP/IP port number. 459 * Port must be >=0 and <=65535. 460 * Return -1 if invalid. 461 */ 462 int 463 a2port(const char *s) 464 { 465 struct servent *se; 466 long long port; 467 const char *errstr; 468 469 port = strtonum(s, 0, 65535, &errstr); 470 if (errstr == NULL) 471 return (int)port; 472 if ((se = getservbyname(s, "tcp")) != NULL) 473 return ntohs(se->s_port); 474 return -1; 475 } 476 477 int 478 a2tun(const char *s, int *remote) 479 { 480 const char *errstr = NULL; 481 char *sp, *ep; 482 int tun; 483 484 if (remote != NULL) { 485 *remote = SSH_TUNID_ANY; 486 sp = xstrdup(s); 487 if ((ep = strchr(sp, ':')) == NULL) { 488 free(sp); 489 return (a2tun(s, NULL)); 490 } 491 ep[0] = '\0'; ep++; 492 *remote = a2tun(ep, NULL); 493 tun = a2tun(sp, NULL); 494 free(sp); 495 return (*remote == SSH_TUNID_ERR ? *remote : tun); 496 } 497 498 if (strcasecmp(s, "any") == 0) 499 return (SSH_TUNID_ANY); 500 501 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 502 if (errstr != NULL) 503 return (SSH_TUNID_ERR); 504 505 return (tun); 506 } 507 508 #define SECONDS 1 509 #define MINUTES (SECONDS * 60) 510 #define HOURS (MINUTES * 60) 511 #define DAYS (HOURS * 24) 512 #define WEEKS (DAYS * 7) 513 514 /* 515 * Convert a time string into seconds; format is 516 * a sequence of: 517 * time[qualifier] 518 * 519 * Valid time qualifiers are: 520 * <none> seconds 521 * s|S seconds 522 * m|M minutes 523 * h|H hours 524 * d|D days 525 * w|W weeks 526 * 527 * Examples: 528 * 90m 90 minutes 529 * 1h30m 90 minutes 530 * 2d 2 days 531 * 1w 1 week 532 * 533 * Return -1 if time string is invalid. 534 */ 535 int 536 convtime(const char *s) 537 { 538 long total, secs, multiplier; 539 const char *p; 540 char *endp; 541 542 errno = 0; 543 total = 0; 544 p = s; 545 546 if (p == NULL || *p == '\0') 547 return -1; 548 549 while (*p) { 550 secs = strtol(p, &endp, 10); 551 if (p == endp || 552 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 553 secs < 0) 554 return -1; 555 556 multiplier = 1; 557 switch (*endp++) { 558 case '\0': 559 endp--; 560 break; 561 case 's': 562 case 'S': 563 break; 564 case 'm': 565 case 'M': 566 multiplier = MINUTES; 567 break; 568 case 'h': 569 case 'H': 570 multiplier = HOURS; 571 break; 572 case 'd': 573 case 'D': 574 multiplier = DAYS; 575 break; 576 case 'w': 577 case 'W': 578 multiplier = WEEKS; 579 break; 580 default: 581 return -1; 582 } 583 if (secs > INT_MAX / multiplier) 584 return -1; 585 secs *= multiplier; 586 if (total > INT_MAX - secs) 587 return -1; 588 total += secs; 589 if (total < 0) 590 return -1; 591 p = endp; 592 } 593 594 return total; 595 } 596 597 #define TF_BUFS 8 598 #define TF_LEN 9 599 600 const char * 601 fmt_timeframe(time_t t) 602 { 603 char *buf; 604 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 605 static int idx = 0; 606 unsigned int sec, min, hrs, day; 607 unsigned long long week; 608 609 buf = tfbuf[idx++]; 610 if (idx == TF_BUFS) 611 idx = 0; 612 613 week = t; 614 615 sec = week % 60; 616 week /= 60; 617 min = week % 60; 618 week /= 60; 619 hrs = week % 24; 620 week /= 24; 621 day = week % 7; 622 week /= 7; 623 624 if (week > 0) 625 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 626 else if (day > 0) 627 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 628 else 629 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 630 631 return (buf); 632 } 633 634 /* 635 * Returns a standardized host+port identifier string. 636 * Caller must free returned string. 637 */ 638 char * 639 put_host_port(const char *host, u_short port) 640 { 641 char *hoststr; 642 643 if (port == 0 || port == SSH_DEFAULT_PORT) 644 return(xstrdup(host)); 645 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 646 fatal("put_host_port: asprintf: %s", strerror(errno)); 647 debug3("put_host_port: %s", hoststr); 648 return hoststr; 649 } 650 651 /* 652 * Search for next delimiter between hostnames/addresses and ports. 653 * Argument may be modified (for termination). 654 * Returns *cp if parsing succeeds. 655 * *cp is set to the start of the next field, if one was found. 656 * The delimiter char, if present, is stored in delim. 657 * If this is the last field, *cp is set to NULL. 658 */ 659 char * 660 hpdelim2(char **cp, char *delim) 661 { 662 char *s, *old; 663 664 if (cp == NULL || *cp == NULL) 665 return NULL; 666 667 old = s = *cp; 668 if (*s == '[') { 669 if ((s = strchr(s, ']')) == NULL) 670 return NULL; 671 else 672 s++; 673 } else if ((s = strpbrk(s, ":/")) == NULL) 674 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 675 676 switch (*s) { 677 case '\0': 678 *cp = NULL; /* no more fields*/ 679 break; 680 681 case ':': 682 case '/': 683 if (delim != NULL) 684 *delim = *s; 685 *s = '\0'; /* terminate */ 686 *cp = s + 1; 687 break; 688 689 default: 690 return NULL; 691 } 692 693 return old; 694 } 695 696 /* The common case: only accept colon as delimiter. */ 697 char * 698 hpdelim(char **cp) 699 { 700 char *r, delim = '\0'; 701 702 r = hpdelim2(cp, &delim); 703 if (delim == '/') 704 return NULL; 705 return r; 706 } 707 708 char * 709 cleanhostname(char *host) 710 { 711 if (*host == '[' && host[strlen(host) - 1] == ']') { 712 host[strlen(host) - 1] = '\0'; 713 return (host + 1); 714 } else 715 return host; 716 } 717 718 char * 719 colon(char *cp) 720 { 721 int flag = 0; 722 723 if (*cp == ':') /* Leading colon is part of file name. */ 724 return NULL; 725 if (*cp == '[') 726 flag = 1; 727 728 for (; *cp; ++cp) { 729 if (*cp == '@' && *(cp+1) == '[') 730 flag = 1; 731 if (*cp == ']' && *(cp+1) == ':' && flag) 732 return (cp+1); 733 if (*cp == ':' && !flag) 734 return (cp); 735 if (*cp == '/') 736 return NULL; 737 } 738 return NULL; 739 } 740 741 /* 742 * Parse a [user@]host:[path] string. 743 * Caller must free returned user, host and path. 744 * Any of the pointer return arguments may be NULL (useful for syntax checking). 745 * If user was not specified then *userp will be set to NULL. 746 * If host was not specified then *hostp will be set to NULL. 747 * If path was not specified then *pathp will be set to ".". 748 * Returns 0 on success, -1 on failure. 749 */ 750 int 751 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 752 { 753 char *user = NULL, *host = NULL, *path = NULL; 754 char *sdup, *tmp; 755 int ret = -1; 756 757 if (userp != NULL) 758 *userp = NULL; 759 if (hostp != NULL) 760 *hostp = NULL; 761 if (pathp != NULL) 762 *pathp = NULL; 763 764 sdup = xstrdup(s); 765 766 /* Check for remote syntax: [user@]host:[path] */ 767 if ((tmp = colon(sdup)) == NULL) 768 goto out; 769 770 /* Extract optional path */ 771 *tmp++ = '\0'; 772 if (*tmp == '\0') 773 tmp = "."; 774 path = xstrdup(tmp); 775 776 /* Extract optional user and mandatory host */ 777 tmp = strrchr(sdup, '@'); 778 if (tmp != NULL) { 779 *tmp++ = '\0'; 780 host = xstrdup(cleanhostname(tmp)); 781 if (*sdup != '\0') 782 user = xstrdup(sdup); 783 } else { 784 host = xstrdup(cleanhostname(sdup)); 785 user = NULL; 786 } 787 788 /* Success */ 789 if (userp != NULL) { 790 *userp = user; 791 user = NULL; 792 } 793 if (hostp != NULL) { 794 *hostp = host; 795 host = NULL; 796 } 797 if (pathp != NULL) { 798 *pathp = path; 799 path = NULL; 800 } 801 ret = 0; 802 out: 803 free(sdup); 804 free(user); 805 free(host); 806 free(path); 807 return ret; 808 } 809 810 /* 811 * Parse a [user@]host[:port] string. 812 * Caller must free returned user and host. 813 * Any of the pointer return arguments may be NULL (useful for syntax checking). 814 * If user was not specified then *userp will be set to NULL. 815 * If port was not specified then *portp will be -1. 816 * Returns 0 on success, -1 on failure. 817 */ 818 int 819 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 820 { 821 char *sdup, *cp, *tmp; 822 char *user = NULL, *host = NULL; 823 int port = -1, ret = -1; 824 825 if (userp != NULL) 826 *userp = NULL; 827 if (hostp != NULL) 828 *hostp = NULL; 829 if (portp != NULL) 830 *portp = -1; 831 832 if ((sdup = tmp = strdup(s)) == NULL) 833 return -1; 834 /* Extract optional username */ 835 if ((cp = strrchr(tmp, '@')) != NULL) { 836 *cp = '\0'; 837 if (*tmp == '\0') 838 goto out; 839 if ((user = strdup(tmp)) == NULL) 840 goto out; 841 tmp = cp + 1; 842 } 843 /* Extract mandatory hostname */ 844 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 845 goto out; 846 host = xstrdup(cleanhostname(cp)); 847 /* Convert and verify optional port */ 848 if (tmp != NULL && *tmp != '\0') { 849 if ((port = a2port(tmp)) <= 0) 850 goto out; 851 } 852 /* Success */ 853 if (userp != NULL) { 854 *userp = user; 855 user = NULL; 856 } 857 if (hostp != NULL) { 858 *hostp = host; 859 host = NULL; 860 } 861 if (portp != NULL) 862 *portp = port; 863 ret = 0; 864 out: 865 free(sdup); 866 free(user); 867 free(host); 868 return ret; 869 } 870 871 /* 872 * Converts a two-byte hex string to decimal. 873 * Returns the decimal value or -1 for invalid input. 874 */ 875 static int 876 hexchar(const char *s) 877 { 878 unsigned char result[2]; 879 int i; 880 881 for (i = 0; i < 2; i++) { 882 if (s[i] >= '0' && s[i] <= '9') 883 result[i] = (unsigned char)(s[i] - '0'); 884 else if (s[i] >= 'a' && s[i] <= 'f') 885 result[i] = (unsigned char)(s[i] - 'a') + 10; 886 else if (s[i] >= 'A' && s[i] <= 'F') 887 result[i] = (unsigned char)(s[i] - 'A') + 10; 888 else 889 return -1; 890 } 891 return (result[0] << 4) | result[1]; 892 } 893 894 /* 895 * Decode an url-encoded string. 896 * Returns a newly allocated string on success or NULL on failure. 897 */ 898 static char * 899 urldecode(const char *src) 900 { 901 char *ret, *dst; 902 int ch; 903 size_t srclen; 904 905 if ((srclen = strlen(src)) >= SIZE_MAX) 906 fatal_f("input too large"); 907 ret = xmalloc(srclen + 1); 908 for (dst = ret; *src != '\0'; src++) { 909 switch (*src) { 910 case '+': 911 *dst++ = ' '; 912 break; 913 case '%': 914 if (!isxdigit((unsigned char)src[1]) || 915 !isxdigit((unsigned char)src[2]) || 916 (ch = hexchar(src + 1)) == -1) { 917 free(ret); 918 return NULL; 919 } 920 *dst++ = ch; 921 src += 2; 922 break; 923 default: 924 *dst++ = *src; 925 break; 926 } 927 } 928 *dst = '\0'; 929 930 return ret; 931 } 932 933 /* 934 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 935 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 936 * Either user or path may be url-encoded (but not host or port). 937 * Caller must free returned user, host and path. 938 * Any of the pointer return arguments may be NULL (useful for syntax checking) 939 * but the scheme must always be specified. 940 * If user was not specified then *userp will be set to NULL. 941 * If port was not specified then *portp will be -1. 942 * If path was not specified then *pathp will be set to NULL. 943 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 944 */ 945 int 946 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 947 int *portp, char **pathp) 948 { 949 char *uridup, *cp, *tmp, ch; 950 char *user = NULL, *host = NULL, *path = NULL; 951 int port = -1, ret = -1; 952 size_t len; 953 954 len = strlen(scheme); 955 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 956 return 1; 957 uri += len + 3; 958 959 if (userp != NULL) 960 *userp = NULL; 961 if (hostp != NULL) 962 *hostp = NULL; 963 if (portp != NULL) 964 *portp = -1; 965 if (pathp != NULL) 966 *pathp = NULL; 967 968 uridup = tmp = xstrdup(uri); 969 970 /* Extract optional ssh-info (username + connection params) */ 971 if ((cp = strchr(tmp, '@')) != NULL) { 972 char *delim; 973 974 *cp = '\0'; 975 /* Extract username and connection params */ 976 if ((delim = strchr(tmp, ';')) != NULL) { 977 /* Just ignore connection params for now */ 978 *delim = '\0'; 979 } 980 if (*tmp == '\0') { 981 /* Empty username */ 982 goto out; 983 } 984 if ((user = urldecode(tmp)) == NULL) 985 goto out; 986 tmp = cp + 1; 987 } 988 989 /* Extract mandatory hostname */ 990 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 991 goto out; 992 host = xstrdup(cleanhostname(cp)); 993 if (!valid_domain(host, 0, NULL)) 994 goto out; 995 996 if (tmp != NULL && *tmp != '\0') { 997 if (ch == ':') { 998 /* Convert and verify port. */ 999 if ((cp = strchr(tmp, '/')) != NULL) 1000 *cp = '\0'; 1001 if ((port = a2port(tmp)) <= 0) 1002 goto out; 1003 tmp = cp ? cp + 1 : NULL; 1004 } 1005 if (tmp != NULL && *tmp != '\0') { 1006 /* Extract optional path */ 1007 if ((path = urldecode(tmp)) == NULL) 1008 goto out; 1009 } 1010 } 1011 1012 /* Success */ 1013 if (userp != NULL) { 1014 *userp = user; 1015 user = NULL; 1016 } 1017 if (hostp != NULL) { 1018 *hostp = host; 1019 host = NULL; 1020 } 1021 if (portp != NULL) 1022 *portp = port; 1023 if (pathp != NULL) { 1024 *pathp = path; 1025 path = NULL; 1026 } 1027 ret = 0; 1028 out: 1029 free(uridup); 1030 free(user); 1031 free(host); 1032 free(path); 1033 return ret; 1034 } 1035 1036 /* function to assist building execv() arguments */ 1037 void 1038 addargs(arglist *args, char *fmt, ...) 1039 { 1040 va_list ap; 1041 char *cp; 1042 u_int nalloc; 1043 int r; 1044 1045 va_start(ap, fmt); 1046 r = vasprintf(&cp, fmt, ap); 1047 va_end(ap); 1048 if (r == -1) 1049 fatal_f("argument too long"); 1050 1051 nalloc = args->nalloc; 1052 if (args->list == NULL) { 1053 nalloc = 32; 1054 args->num = 0; 1055 } else if (args->num > (256 * 1024)) 1056 fatal_f("too many arguments"); 1057 else if (args->num >= args->nalloc) 1058 fatal_f("arglist corrupt"); 1059 else if (args->num+2 >= nalloc) 1060 nalloc *= 2; 1061 1062 args->list = xrecallocarray(args->list, args->nalloc, 1063 nalloc, sizeof(char *)); 1064 args->nalloc = nalloc; 1065 args->list[args->num++] = cp; 1066 args->list[args->num] = NULL; 1067 } 1068 1069 void 1070 replacearg(arglist *args, u_int which, char *fmt, ...) 1071 { 1072 va_list ap; 1073 char *cp; 1074 int r; 1075 1076 va_start(ap, fmt); 1077 r = vasprintf(&cp, fmt, ap); 1078 va_end(ap); 1079 if (r == -1) 1080 fatal_f("argument too long"); 1081 if (args->list == NULL || args->num >= args->nalloc) 1082 fatal_f("arglist corrupt"); 1083 1084 if (which >= args->num) 1085 fatal_f("tried to replace invalid arg %d >= %d", 1086 which, args->num); 1087 free(args->list[which]); 1088 args->list[which] = cp; 1089 } 1090 1091 void 1092 freeargs(arglist *args) 1093 { 1094 u_int i; 1095 1096 if (args == NULL) 1097 return; 1098 if (args->list != NULL && args->num < args->nalloc) { 1099 for (i = 0; i < args->num; i++) 1100 free(args->list[i]); 1101 free(args->list); 1102 } 1103 args->nalloc = args->num = 0; 1104 args->list = NULL; 1105 } 1106 1107 /* 1108 * Expands tildes in the file name. Returns data allocated by xmalloc. 1109 * Warning: this calls getpw*. 1110 */ 1111 int 1112 tilde_expand(const char *filename, uid_t uid, char **retp) 1113 { 1114 char *ocopy = NULL, *copy, *s = NULL; 1115 const char *path = NULL, *user = NULL; 1116 struct passwd *pw; 1117 size_t len; 1118 int ret = -1, r, slash; 1119 1120 *retp = NULL; 1121 if (*filename != '~') { 1122 *retp = xstrdup(filename); 1123 return 0; 1124 } 1125 ocopy = copy = xstrdup(filename + 1); 1126 1127 if (*copy == '\0') /* ~ */ 1128 path = NULL; 1129 else if (*copy == '/') { 1130 copy += strspn(copy, "/"); 1131 if (*copy == '\0') 1132 path = NULL; /* ~/ */ 1133 else 1134 path = copy; /* ~/path */ 1135 } else { 1136 user = copy; 1137 if ((path = strchr(copy, '/')) != NULL) { 1138 copy[path - copy] = '\0'; 1139 path++; 1140 path += strspn(path, "/"); 1141 if (*path == '\0') /* ~user/ */ 1142 path = NULL; 1143 /* else ~user/path */ 1144 } 1145 /* else ~user */ 1146 } 1147 if (user != NULL) { 1148 if ((pw = getpwnam(user)) == NULL) { 1149 error_f("No such user %s", user); 1150 goto out; 1151 } 1152 } else if ((pw = getpwuid(uid)) == NULL) { 1153 error_f("No such uid %ld", (long)uid); 1154 goto out; 1155 } 1156 1157 /* Make sure directory has a trailing '/' */ 1158 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1159 1160 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1161 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1162 error_f("xasprintf failed"); 1163 goto out; 1164 } 1165 if (r >= PATH_MAX) { 1166 error_f("Path too long"); 1167 goto out; 1168 } 1169 /* success */ 1170 ret = 0; 1171 *retp = s; 1172 s = NULL; 1173 out: 1174 free(s); 1175 free(ocopy); 1176 return ret; 1177 } 1178 1179 char * 1180 tilde_expand_filename(const char *filename, uid_t uid) 1181 { 1182 char *ret; 1183 1184 if (tilde_expand(filename, uid, &ret) != 0) 1185 cleanup_exit(255); 1186 return ret; 1187 } 1188 1189 /* 1190 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1191 * substitutions. A number of escapes may be specified as 1192 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1193 * by a NULL escape_char. Returns replaced string in memory allocated by 1194 * xmalloc which the caller must free. 1195 */ 1196 static char * 1197 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1198 const char *string, va_list ap) 1199 { 1200 #define EXPAND_MAX_KEYS 64 1201 u_int num_keys = 0, i; 1202 struct { 1203 const char *key; 1204 const char *repl; 1205 } keys[EXPAND_MAX_KEYS]; 1206 struct sshbuf *buf; 1207 int r, missingvar = 0; 1208 char *ret = NULL, *var, *varend, *val; 1209 size_t len; 1210 1211 if ((buf = sshbuf_new()) == NULL) 1212 fatal_f("sshbuf_new failed"); 1213 if (parseerror == NULL) 1214 fatal_f("null parseerror arg"); 1215 *parseerror = 1; 1216 1217 /* Gather keys if we're doing percent expansion. */ 1218 if (percent) { 1219 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1220 keys[num_keys].key = va_arg(ap, char *); 1221 if (keys[num_keys].key == NULL) 1222 break; 1223 keys[num_keys].repl = va_arg(ap, char *); 1224 if (keys[num_keys].repl == NULL) { 1225 fatal_f("NULL replacement for token %s", 1226 keys[num_keys].key); 1227 } 1228 } 1229 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1230 fatal_f("too many keys"); 1231 if (num_keys == 0) 1232 fatal_f("percent expansion without token list"); 1233 } 1234 1235 /* Expand string */ 1236 for (i = 0; *string != '\0'; string++) { 1237 /* Optionally process ${ENVIRONMENT} expansions. */ 1238 if (dollar && string[0] == '$' && string[1] == '{') { 1239 string += 2; /* skip over '${' */ 1240 if ((varend = strchr(string, '}')) == NULL) { 1241 error_f("environment variable '%s' missing " 1242 "closing '}'", string); 1243 goto out; 1244 } 1245 len = varend - string; 1246 if (len == 0) { 1247 error_f("zero-length environment variable"); 1248 goto out; 1249 } 1250 var = xmalloc(len + 1); 1251 (void)strlcpy(var, string, len + 1); 1252 if ((val = getenv(var)) == NULL) { 1253 error_f("env var ${%s} has no value", var); 1254 missingvar = 1; 1255 } else { 1256 debug3_f("expand ${%s} -> '%s'", var, val); 1257 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1258 fatal_fr(r, "sshbuf_put ${}"); 1259 } 1260 free(var); 1261 string += len; 1262 continue; 1263 } 1264 1265 /* 1266 * Process percent expansions if we have a list of TOKENs. 1267 * If we're not doing percent expansion everything just gets 1268 * appended here. 1269 */ 1270 if (*string != '%' || !percent) { 1271 append: 1272 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1273 fatal_fr(r, "sshbuf_put_u8 %%"); 1274 continue; 1275 } 1276 string++; 1277 /* %% case */ 1278 if (*string == '%') 1279 goto append; 1280 if (*string == '\0') { 1281 error_f("invalid format"); 1282 goto out; 1283 } 1284 for (i = 0; i < num_keys; i++) { 1285 if (strchr(keys[i].key, *string) != NULL) { 1286 if ((r = sshbuf_put(buf, keys[i].repl, 1287 strlen(keys[i].repl))) != 0) 1288 fatal_fr(r, "sshbuf_put %%-repl"); 1289 break; 1290 } 1291 } 1292 if (i >= num_keys) { 1293 error_f("unknown key %%%c", *string); 1294 goto out; 1295 } 1296 } 1297 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1298 fatal_f("sshbuf_dup_string failed"); 1299 *parseerror = 0; 1300 out: 1301 sshbuf_free(buf); 1302 return *parseerror ? NULL : ret; 1303 #undef EXPAND_MAX_KEYS 1304 } 1305 1306 /* 1307 * Expand only environment variables. 1308 * Note that although this function is variadic like the other similar 1309 * functions, any such arguments will be unused. 1310 */ 1311 1312 char * 1313 dollar_expand(int *parseerr, const char *string, ...) 1314 { 1315 char *ret; 1316 int err; 1317 va_list ap; 1318 1319 va_start(ap, string); 1320 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1321 va_end(ap); 1322 if (parseerr != NULL) 1323 *parseerr = err; 1324 return ret; 1325 } 1326 1327 /* 1328 * Returns expanded string or NULL if a specified environment variable is 1329 * not defined, or calls fatal if the string is invalid. 1330 */ 1331 char * 1332 percent_expand(const char *string, ...) 1333 { 1334 char *ret; 1335 int err; 1336 va_list ap; 1337 1338 va_start(ap, string); 1339 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1340 va_end(ap); 1341 if (err) 1342 fatal_f("failed"); 1343 return ret; 1344 } 1345 1346 /* 1347 * Returns expanded string or NULL if a specified environment variable is 1348 * not defined, or calls fatal if the string is invalid. 1349 */ 1350 char * 1351 percent_dollar_expand(const char *string, ...) 1352 { 1353 char *ret; 1354 int err; 1355 va_list ap; 1356 1357 va_start(ap, string); 1358 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1359 va_end(ap); 1360 if (err) 1361 fatal_f("failed"); 1362 return ret; 1363 } 1364 1365 int 1366 tun_open(int tun, int mode, char **ifname) 1367 { 1368 struct ifreq ifr; 1369 char name[100]; 1370 int fd = -1, sock; 1371 const char *tunbase = "tun"; 1372 1373 if (ifname != NULL) 1374 *ifname = NULL; 1375 1376 if (mode == SSH_TUNMODE_ETHERNET) 1377 tunbase = "tap"; 1378 1379 /* Open the tunnel device */ 1380 if (tun <= SSH_TUNID_MAX) { 1381 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1382 fd = open(name, O_RDWR); 1383 } else if (tun == SSH_TUNID_ANY) { 1384 for (tun = 100; tun >= 0; tun--) { 1385 snprintf(name, sizeof(name), "/dev/%s%d", 1386 tunbase, tun); 1387 if ((fd = open(name, O_RDWR)) >= 0) 1388 break; 1389 } 1390 } else { 1391 debug_f("invalid tunnel %u", tun); 1392 return -1; 1393 } 1394 1395 if (fd == -1) { 1396 debug_f("%s open: %s", name, strerror(errno)); 1397 return -1; 1398 } 1399 1400 debug_f("%s mode %d fd %d", name, mode, fd); 1401 1402 /* Bring interface up if it is not already */ 1403 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1404 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1405 goto failed; 1406 1407 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1408 debug_f("get interface %s flags: %s", ifr.ifr_name, 1409 strerror(errno)); 1410 goto failed; 1411 } 1412 1413 if (!(ifr.ifr_flags & IFF_UP)) { 1414 ifr.ifr_flags |= IFF_UP; 1415 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1416 debug_f("activate interface %s: %s", ifr.ifr_name, 1417 strerror(errno)); 1418 goto failed; 1419 } 1420 } 1421 1422 if (ifname != NULL) 1423 *ifname = xstrdup(ifr.ifr_name); 1424 1425 close(sock); 1426 return fd; 1427 1428 failed: 1429 if (fd >= 0) 1430 close(fd); 1431 if (sock >= 0) 1432 close(sock); 1433 return -1; 1434 } 1435 1436 void 1437 sanitise_stdfd(void) 1438 { 1439 int nullfd, dupfd; 1440 1441 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1442 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1443 strerror(errno)); 1444 exit(1); 1445 } 1446 while (++dupfd <= STDERR_FILENO) { 1447 /* Only populate closed fds. */ 1448 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1449 if (dup2(nullfd, dupfd) == -1) { 1450 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1451 exit(1); 1452 } 1453 } 1454 } 1455 if (nullfd > STDERR_FILENO) 1456 close(nullfd); 1457 } 1458 1459 char * 1460 tohex(const void *vp, size_t l) 1461 { 1462 const u_char *p = (const u_char *)vp; 1463 char b[3], *r; 1464 size_t i, hl; 1465 1466 if (l > 65536) 1467 return xstrdup("tohex: length > 65536"); 1468 1469 hl = l * 2 + 1; 1470 r = xcalloc(1, hl); 1471 for (i = 0; i < l; i++) { 1472 snprintf(b, sizeof(b), "%02x", p[i]); 1473 strlcat(r, b, hl); 1474 } 1475 return (r); 1476 } 1477 1478 /* 1479 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1480 * then the separator 'sep' will be prepended before the formatted arguments. 1481 * Extended strings are heap allocated. 1482 */ 1483 void 1484 xextendf(char **sp, const char *sep, const char *fmt, ...) 1485 { 1486 va_list ap; 1487 char *tmp1, *tmp2; 1488 1489 va_start(ap, fmt); 1490 xvasprintf(&tmp1, fmt, ap); 1491 va_end(ap); 1492 1493 if (*sp == NULL || **sp == '\0') { 1494 free(*sp); 1495 *sp = tmp1; 1496 return; 1497 } 1498 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1499 free(tmp1); 1500 free(*sp); 1501 *sp = tmp2; 1502 } 1503 1504 1505 u_int64_t 1506 get_u64(const void *vp) 1507 { 1508 const u_char *p = (const u_char *)vp; 1509 u_int64_t v; 1510 1511 v = (u_int64_t)p[0] << 56; 1512 v |= (u_int64_t)p[1] << 48; 1513 v |= (u_int64_t)p[2] << 40; 1514 v |= (u_int64_t)p[3] << 32; 1515 v |= (u_int64_t)p[4] << 24; 1516 v |= (u_int64_t)p[5] << 16; 1517 v |= (u_int64_t)p[6] << 8; 1518 v |= (u_int64_t)p[7]; 1519 1520 return (v); 1521 } 1522 1523 u_int32_t 1524 get_u32(const void *vp) 1525 { 1526 const u_char *p = (const u_char *)vp; 1527 u_int32_t v; 1528 1529 v = (u_int32_t)p[0] << 24; 1530 v |= (u_int32_t)p[1] << 16; 1531 v |= (u_int32_t)p[2] << 8; 1532 v |= (u_int32_t)p[3]; 1533 1534 return (v); 1535 } 1536 1537 u_int32_t 1538 get_u32_le(const void *vp) 1539 { 1540 const u_char *p = (const u_char *)vp; 1541 u_int32_t v; 1542 1543 v = (u_int32_t)p[0]; 1544 v |= (u_int32_t)p[1] << 8; 1545 v |= (u_int32_t)p[2] << 16; 1546 v |= (u_int32_t)p[3] << 24; 1547 1548 return (v); 1549 } 1550 1551 u_int16_t 1552 get_u16(const void *vp) 1553 { 1554 const u_char *p = (const u_char *)vp; 1555 u_int16_t v; 1556 1557 v = (u_int16_t)p[0] << 8; 1558 v |= (u_int16_t)p[1]; 1559 1560 return (v); 1561 } 1562 1563 void 1564 put_u64(void *vp, u_int64_t v) 1565 { 1566 u_char *p = (u_char *)vp; 1567 1568 p[0] = (u_char)(v >> 56) & 0xff; 1569 p[1] = (u_char)(v >> 48) & 0xff; 1570 p[2] = (u_char)(v >> 40) & 0xff; 1571 p[3] = (u_char)(v >> 32) & 0xff; 1572 p[4] = (u_char)(v >> 24) & 0xff; 1573 p[5] = (u_char)(v >> 16) & 0xff; 1574 p[6] = (u_char)(v >> 8) & 0xff; 1575 p[7] = (u_char)v & 0xff; 1576 } 1577 1578 void 1579 put_u32(void *vp, u_int32_t v) 1580 { 1581 u_char *p = (u_char *)vp; 1582 1583 p[0] = (u_char)(v >> 24) & 0xff; 1584 p[1] = (u_char)(v >> 16) & 0xff; 1585 p[2] = (u_char)(v >> 8) & 0xff; 1586 p[3] = (u_char)v & 0xff; 1587 } 1588 1589 void 1590 put_u32_le(void *vp, u_int32_t v) 1591 { 1592 u_char *p = (u_char *)vp; 1593 1594 p[0] = (u_char)v & 0xff; 1595 p[1] = (u_char)(v >> 8) & 0xff; 1596 p[2] = (u_char)(v >> 16) & 0xff; 1597 p[3] = (u_char)(v >> 24) & 0xff; 1598 } 1599 1600 void 1601 put_u16(void *vp, u_int16_t v) 1602 { 1603 u_char *p = (u_char *)vp; 1604 1605 p[0] = (u_char)(v >> 8) & 0xff; 1606 p[1] = (u_char)v & 0xff; 1607 } 1608 1609 void 1610 ms_subtract_diff(struct timeval *start, int *ms) 1611 { 1612 struct timeval diff, finish; 1613 1614 monotime_tv(&finish); 1615 timersub(&finish, start, &diff); 1616 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1617 } 1618 1619 void 1620 ms_to_timespec(struct timespec *ts, int ms) 1621 { 1622 if (ms < 0) 1623 ms = 0; 1624 ts->tv_sec = ms / 1000; 1625 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1626 } 1627 1628 void 1629 monotime_ts(struct timespec *ts) 1630 { 1631 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1632 fatal("clock_gettime: %s", strerror(errno)); 1633 } 1634 1635 void 1636 monotime_tv(struct timeval *tv) 1637 { 1638 struct timespec ts; 1639 1640 monotime_ts(&ts); 1641 tv->tv_sec = ts.tv_sec; 1642 tv->tv_usec = ts.tv_nsec / 1000; 1643 } 1644 1645 time_t 1646 monotime(void) 1647 { 1648 struct timespec ts; 1649 1650 monotime_ts(&ts); 1651 return (ts.tv_sec); 1652 } 1653 1654 double 1655 monotime_double(void) 1656 { 1657 struct timespec ts; 1658 1659 monotime_ts(&ts); 1660 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1661 } 1662 1663 void 1664 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1665 { 1666 bw->buflen = buflen; 1667 bw->rate = kbps; 1668 bw->thresh = buflen; 1669 bw->lamt = 0; 1670 timerclear(&bw->bwstart); 1671 timerclear(&bw->bwend); 1672 } 1673 1674 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1675 void 1676 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1677 { 1678 u_int64_t waitlen; 1679 struct timespec ts, rm; 1680 1681 bw->lamt += read_len; 1682 if (!timerisset(&bw->bwstart)) { 1683 monotime_tv(&bw->bwstart); 1684 return; 1685 } 1686 if (bw->lamt < bw->thresh) 1687 return; 1688 1689 monotime_tv(&bw->bwend); 1690 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1691 if (!timerisset(&bw->bwend)) 1692 return; 1693 1694 bw->lamt *= 8; 1695 waitlen = (double)1000000L * bw->lamt / bw->rate; 1696 1697 bw->bwstart.tv_sec = waitlen / 1000000L; 1698 bw->bwstart.tv_usec = waitlen % 1000000L; 1699 1700 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1701 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1702 1703 /* Adjust the wait time */ 1704 if (bw->bwend.tv_sec) { 1705 bw->thresh /= 2; 1706 if (bw->thresh < bw->buflen / 4) 1707 bw->thresh = bw->buflen / 4; 1708 } else if (bw->bwend.tv_usec < 10000) { 1709 bw->thresh *= 2; 1710 if (bw->thresh > bw->buflen * 8) 1711 bw->thresh = bw->buflen * 8; 1712 } 1713 1714 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1715 while (nanosleep(&ts, &rm) == -1) { 1716 if (errno != EINTR) 1717 break; 1718 ts = rm; 1719 } 1720 } 1721 1722 bw->lamt = 0; 1723 monotime_tv(&bw->bwstart); 1724 } 1725 1726 /* Make a template filename for mk[sd]temp() */ 1727 void 1728 mktemp_proto(char *s, size_t len) 1729 { 1730 const char *tmpdir; 1731 int r; 1732 1733 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1734 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1735 if (r > 0 && (size_t)r < len) 1736 return; 1737 } 1738 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1739 if (r < 0 || (size_t)r >= len) 1740 fatal_f("template string too short"); 1741 } 1742 1743 static const struct { 1744 const char *name; 1745 int value; 1746 } ipqos[] = { 1747 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1748 { "af11", IPTOS_DSCP_AF11 }, 1749 { "af12", IPTOS_DSCP_AF12 }, 1750 { "af13", IPTOS_DSCP_AF13 }, 1751 { "af21", IPTOS_DSCP_AF21 }, 1752 { "af22", IPTOS_DSCP_AF22 }, 1753 { "af23", IPTOS_DSCP_AF23 }, 1754 { "af31", IPTOS_DSCP_AF31 }, 1755 { "af32", IPTOS_DSCP_AF32 }, 1756 { "af33", IPTOS_DSCP_AF33 }, 1757 { "af41", IPTOS_DSCP_AF41 }, 1758 { "af42", IPTOS_DSCP_AF42 }, 1759 { "af43", IPTOS_DSCP_AF43 }, 1760 { "cs0", IPTOS_DSCP_CS0 }, 1761 { "cs1", IPTOS_DSCP_CS1 }, 1762 { "cs2", IPTOS_DSCP_CS2 }, 1763 { "cs3", IPTOS_DSCP_CS3 }, 1764 { "cs4", IPTOS_DSCP_CS4 }, 1765 { "cs5", IPTOS_DSCP_CS5 }, 1766 { "cs6", IPTOS_DSCP_CS6 }, 1767 { "cs7", IPTOS_DSCP_CS7 }, 1768 { "ef", IPTOS_DSCP_EF }, 1769 { "le", IPTOS_DSCP_LE }, 1770 { "lowdelay", IPTOS_LOWDELAY }, 1771 { "throughput", IPTOS_THROUGHPUT }, 1772 { "reliability", IPTOS_RELIABILITY }, 1773 { NULL, -1 } 1774 }; 1775 1776 int 1777 parse_ipqos(const char *cp) 1778 { 1779 u_int i; 1780 char *ep; 1781 long val; 1782 1783 if (cp == NULL) 1784 return -1; 1785 for (i = 0; ipqos[i].name != NULL; i++) { 1786 if (strcasecmp(cp, ipqos[i].name) == 0) 1787 return ipqos[i].value; 1788 } 1789 /* Try parsing as an integer */ 1790 val = strtol(cp, &ep, 0); 1791 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1792 return -1; 1793 return val; 1794 } 1795 1796 const char * 1797 iptos2str(int iptos) 1798 { 1799 int i; 1800 static char iptos_str[sizeof "0xff"]; 1801 1802 for (i = 0; ipqos[i].name != NULL; i++) { 1803 if (ipqos[i].value == iptos) 1804 return ipqos[i].name; 1805 } 1806 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1807 return iptos_str; 1808 } 1809 1810 void 1811 lowercase(char *s) 1812 { 1813 for (; *s; s++) 1814 *s = tolower((u_char)*s); 1815 } 1816 1817 int 1818 unix_listener(const char *path, int backlog, int unlink_first) 1819 { 1820 struct sockaddr_un sunaddr; 1821 int saved_errno, sock; 1822 1823 memset(&sunaddr, 0, sizeof(sunaddr)); 1824 sunaddr.sun_family = AF_UNIX; 1825 if (strlcpy(sunaddr.sun_path, path, 1826 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1827 error_f("path \"%s\" too long for Unix domain socket", path); 1828 errno = ENAMETOOLONG; 1829 return -1; 1830 } 1831 1832 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1833 if (sock == -1) { 1834 saved_errno = errno; 1835 error_f("socket: %.100s", strerror(errno)); 1836 errno = saved_errno; 1837 return -1; 1838 } 1839 if (unlink_first == 1) { 1840 if (unlink(path) != 0 && errno != ENOENT) 1841 error("unlink(%s): %.100s", path, strerror(errno)); 1842 } 1843 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1844 saved_errno = errno; 1845 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1846 close(sock); 1847 errno = saved_errno; 1848 return -1; 1849 } 1850 if (listen(sock, backlog) == -1) { 1851 saved_errno = errno; 1852 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1853 close(sock); 1854 unlink(path); 1855 errno = saved_errno; 1856 return -1; 1857 } 1858 return sock; 1859 } 1860 1861 /* 1862 * Compares two strings that maybe be NULL. Returns non-zero if strings 1863 * are both NULL or are identical, returns zero otherwise. 1864 */ 1865 static int 1866 strcmp_maybe_null(const char *a, const char *b) 1867 { 1868 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1869 return 0; 1870 if (a != NULL && strcmp(a, b) != 0) 1871 return 0; 1872 return 1; 1873 } 1874 1875 /* 1876 * Compare two forwards, returning non-zero if they are identical or 1877 * zero otherwise. 1878 */ 1879 int 1880 forward_equals(const struct Forward *a, const struct Forward *b) 1881 { 1882 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1883 return 0; 1884 if (a->listen_port != b->listen_port) 1885 return 0; 1886 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1887 return 0; 1888 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1889 return 0; 1890 if (a->connect_port != b->connect_port) 1891 return 0; 1892 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1893 return 0; 1894 /* allocated_port and handle are not checked */ 1895 return 1; 1896 } 1897 1898 /* returns 1 if process is already daemonized, 0 otherwise */ 1899 int 1900 daemonized(void) 1901 { 1902 int fd; 1903 1904 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1905 close(fd); 1906 return 0; /* have controlling terminal */ 1907 } 1908 if (getppid() != 1) 1909 return 0; /* parent is not init */ 1910 if (getsid(0) != getpid()) 1911 return 0; /* not session leader */ 1912 debug3("already daemonized"); 1913 return 1; 1914 } 1915 1916 /* 1917 * Splits 's' into an argument vector. Handles quoted string and basic 1918 * escape characters (\\, \", \'). Caller must free the argument vector 1919 * and its members. 1920 */ 1921 int 1922 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1923 { 1924 int r = SSH_ERR_INTERNAL_ERROR; 1925 int argc = 0, quote, i, j; 1926 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1927 1928 *argvp = NULL; 1929 *argcp = 0; 1930 1931 for (i = 0; s[i] != '\0'; i++) { 1932 /* Skip leading whitespace */ 1933 if (s[i] == ' ' || s[i] == '\t') 1934 continue; 1935 if (terminate_on_comment && s[i] == '#') 1936 break; 1937 /* Start of a token */ 1938 quote = 0; 1939 1940 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1941 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1942 argv[argc] = NULL; 1943 1944 /* Copy the token in, removing escapes */ 1945 for (j = 0; s[i] != '\0'; i++) { 1946 if (s[i] == '\\') { 1947 if (s[i + 1] == '\'' || 1948 s[i + 1] == '\"' || 1949 s[i + 1] == '\\' || 1950 (quote == 0 && s[i + 1] == ' ')) { 1951 i++; /* Skip '\' */ 1952 arg[j++] = s[i]; 1953 } else { 1954 /* Unrecognised escape */ 1955 arg[j++] = s[i]; 1956 } 1957 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1958 break; /* done */ 1959 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1960 quote = s[i]; /* quote start */ 1961 else if (quote != 0 && s[i] == quote) 1962 quote = 0; /* quote end */ 1963 else 1964 arg[j++] = s[i]; 1965 } 1966 if (s[i] == '\0') { 1967 if (quote != 0) { 1968 /* Ran out of string looking for close quote */ 1969 r = SSH_ERR_INVALID_FORMAT; 1970 goto out; 1971 } 1972 break; 1973 } 1974 } 1975 /* Success */ 1976 *argcp = argc; 1977 *argvp = argv; 1978 argc = 0; 1979 argv = NULL; 1980 r = 0; 1981 out: 1982 if (argc != 0 && argv != NULL) { 1983 for (i = 0; i < argc; i++) 1984 free(argv[i]); 1985 free(argv); 1986 } 1987 return r; 1988 } 1989 1990 /* 1991 * Reassemble an argument vector into a string, quoting and escaping as 1992 * necessary. Caller must free returned string. 1993 */ 1994 char * 1995 argv_assemble(int argc, char **argv) 1996 { 1997 int i, j, ws, r; 1998 char c, *ret; 1999 struct sshbuf *buf, *arg; 2000 2001 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2002 fatal_f("sshbuf_new failed"); 2003 2004 for (i = 0; i < argc; i++) { 2005 ws = 0; 2006 sshbuf_reset(arg); 2007 for (j = 0; argv[i][j] != '\0'; j++) { 2008 r = 0; 2009 c = argv[i][j]; 2010 switch (c) { 2011 case ' ': 2012 case '\t': 2013 ws = 1; 2014 r = sshbuf_put_u8(arg, c); 2015 break; 2016 case '\\': 2017 case '\'': 2018 case '"': 2019 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2020 break; 2021 /* FALLTHROUGH */ 2022 default: 2023 r = sshbuf_put_u8(arg, c); 2024 break; 2025 } 2026 if (r != 0) 2027 fatal_fr(r, "sshbuf_put_u8"); 2028 } 2029 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2030 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2031 (r = sshbuf_putb(buf, arg)) != 0 || 2032 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2033 fatal_fr(r, "assemble"); 2034 } 2035 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2036 fatal_f("malloc failed"); 2037 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2038 ret[sshbuf_len(buf)] = '\0'; 2039 sshbuf_free(buf); 2040 sshbuf_free(arg); 2041 return ret; 2042 } 2043 2044 char * 2045 argv_next(int *argcp, char ***argvp) 2046 { 2047 char *ret = (*argvp)[0]; 2048 2049 if (*argcp > 0 && ret != NULL) { 2050 (*argcp)--; 2051 (*argvp)++; 2052 } 2053 return ret; 2054 } 2055 2056 void 2057 argv_consume(int *argcp) 2058 { 2059 *argcp = 0; 2060 } 2061 2062 void 2063 argv_free(char **av, int ac) 2064 { 2065 int i; 2066 2067 if (av == NULL) 2068 return; 2069 for (i = 0; i < ac; i++) 2070 free(av[i]); 2071 free(av); 2072 } 2073 2074 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2075 int 2076 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2077 { 2078 int status; 2079 2080 while (waitpid(pid, &status, 0) == -1) { 2081 if (errno != EINTR) { 2082 error("%s waitpid: %s", tag, strerror(errno)); 2083 return -1; 2084 } 2085 } 2086 if (WIFSIGNALED(status)) { 2087 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2088 return -1; 2089 } else if (WEXITSTATUS(status) != 0) { 2090 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2091 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2092 return -1; 2093 } 2094 return 0; 2095 } 2096 2097 /* 2098 * Check a given path for security. This is defined as all components 2099 * of the path to the file must be owned by either the owner of 2100 * of the file or root and no directories must be group or world writable. 2101 * 2102 * XXX Should any specific check be done for sym links ? 2103 * 2104 * Takes a file name, its stat information (preferably from fstat() to 2105 * avoid races), the uid of the expected owner, their home directory and an 2106 * error buffer plus max size as arguments. 2107 * 2108 * Returns 0 on success and -1 on failure 2109 */ 2110 int 2111 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2112 uid_t uid, char *err, size_t errlen) 2113 { 2114 char buf[PATH_MAX], homedir[PATH_MAX]; 2115 char *cp; 2116 int comparehome = 0; 2117 struct stat st; 2118 2119 if (realpath(name, buf) == NULL) { 2120 snprintf(err, errlen, "realpath %s failed: %s", name, 2121 strerror(errno)); 2122 return -1; 2123 } 2124 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2125 comparehome = 1; 2126 2127 if (!S_ISREG(stp->st_mode)) { 2128 snprintf(err, errlen, "%s is not a regular file", buf); 2129 return -1; 2130 } 2131 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2132 (stp->st_mode & 022) != 0) { 2133 snprintf(err, errlen, "bad ownership or modes for file %s", 2134 buf); 2135 return -1; 2136 } 2137 2138 /* for each component of the canonical path, walking upwards */ 2139 for (;;) { 2140 if ((cp = dirname(buf)) == NULL) { 2141 snprintf(err, errlen, "dirname() failed"); 2142 return -1; 2143 } 2144 strlcpy(buf, cp, sizeof(buf)); 2145 2146 if (stat(buf, &st) == -1 || 2147 (st.st_uid != 0 && st.st_uid != uid) || 2148 (st.st_mode & 022) != 0) { 2149 snprintf(err, errlen, 2150 "bad ownership or modes for directory %s", buf); 2151 return -1; 2152 } 2153 2154 /* If are past the homedir then we can stop */ 2155 if (comparehome && strcmp(homedir, buf) == 0) 2156 break; 2157 2158 /* 2159 * dirname should always complete with a "/" path, 2160 * but we can be paranoid and check for "." too 2161 */ 2162 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2163 break; 2164 } 2165 return 0; 2166 } 2167 2168 /* 2169 * Version of safe_path() that accepts an open file descriptor to 2170 * avoid races. 2171 * 2172 * Returns 0 on success and -1 on failure 2173 */ 2174 int 2175 safe_path_fd(int fd, const char *file, struct passwd *pw, 2176 char *err, size_t errlen) 2177 { 2178 struct stat st; 2179 2180 /* check the open file to avoid races */ 2181 if (fstat(fd, &st) == -1) { 2182 snprintf(err, errlen, "cannot stat file %s: %s", 2183 file, strerror(errno)); 2184 return -1; 2185 } 2186 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2187 } 2188 2189 /* 2190 * Sets the value of the given variable in the environment. If the variable 2191 * already exists, its value is overridden. 2192 */ 2193 void 2194 child_set_env(char ***envp, u_int *envsizep, const char *name, 2195 const char *value) 2196 { 2197 char **env; 2198 u_int envsize; 2199 u_int i, namelen; 2200 2201 if (strchr(name, '=') != NULL) { 2202 error("Invalid environment variable \"%.100s\"", name); 2203 return; 2204 } 2205 2206 /* 2207 * Find the slot where the value should be stored. If the variable 2208 * already exists, we reuse the slot; otherwise we append a new slot 2209 * at the end of the array, expanding if necessary. 2210 */ 2211 env = *envp; 2212 namelen = strlen(name); 2213 for (i = 0; env[i]; i++) 2214 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2215 break; 2216 if (env[i]) { 2217 /* Reuse the slot. */ 2218 free(env[i]); 2219 } else { 2220 /* New variable. Expand if necessary. */ 2221 envsize = *envsizep; 2222 if (i >= envsize - 1) { 2223 if (envsize >= 1000) 2224 fatal("child_set_env: too many env vars"); 2225 envsize += 50; 2226 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2227 *envsizep = envsize; 2228 } 2229 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2230 env[i + 1] = NULL; 2231 } 2232 2233 /* Allocate space and format the variable in the appropriate slot. */ 2234 /* XXX xasprintf */ 2235 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2236 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2237 } 2238 2239 /* 2240 * Check and optionally lowercase a domain name, also removes trailing '.' 2241 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2242 */ 2243 int 2244 valid_domain(char *name, int makelower, const char **errstr) 2245 { 2246 size_t i, l = strlen(name); 2247 u_char c, last = '\0'; 2248 static char errbuf[256]; 2249 2250 if (l == 0) { 2251 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2252 goto bad; 2253 } 2254 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2255 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2256 "starts with invalid character", name); 2257 goto bad; 2258 } 2259 for (i = 0; i < l; i++) { 2260 c = tolower((u_char)name[i]); 2261 if (makelower) 2262 name[i] = (char)c; 2263 if (last == '.' && c == '.') { 2264 snprintf(errbuf, sizeof(errbuf), "domain name " 2265 "\"%.100s\" contains consecutive separators", name); 2266 goto bad; 2267 } 2268 if (c != '.' && c != '-' && !isalnum(c) && 2269 c != '_') /* technically invalid, but common */ { 2270 snprintf(errbuf, sizeof(errbuf), "domain name " 2271 "\"%.100s\" contains invalid characters", name); 2272 goto bad; 2273 } 2274 last = c; 2275 } 2276 if (name[l - 1] == '.') 2277 name[l - 1] = '\0'; 2278 if (errstr != NULL) 2279 *errstr = NULL; 2280 return 1; 2281 bad: 2282 if (errstr != NULL) 2283 *errstr = errbuf; 2284 return 0; 2285 } 2286 2287 /* 2288 * Verify that a environment variable name (not including initial '$') is 2289 * valid; consisting of one or more alphanumeric or underscore characters only. 2290 * Returns 1 on valid, 0 otherwise. 2291 */ 2292 int 2293 valid_env_name(const char *name) 2294 { 2295 const char *cp; 2296 2297 if (name[0] == '\0') 2298 return 0; 2299 for (cp = name; *cp != '\0'; cp++) { 2300 if (!isalnum((u_char)*cp) && *cp != '_') 2301 return 0; 2302 } 2303 return 1; 2304 } 2305 2306 const char * 2307 atoi_err(const char *nptr, int *val) 2308 { 2309 const char *errstr = NULL; 2310 long long num; 2311 2312 if (nptr == NULL || *nptr == '\0') 2313 return "missing"; 2314 num = strtonum(nptr, 0, INT_MAX, &errstr); 2315 if (errstr == NULL) 2316 *val = (int)num; 2317 return errstr; 2318 } 2319 2320 int 2321 parse_absolute_time(const char *s, uint64_t *tp) 2322 { 2323 struct tm tm; 2324 time_t tt; 2325 char buf[32], *fmt; 2326 const char *cp; 2327 size_t l; 2328 int is_utc = 0; 2329 2330 *tp = 0; 2331 2332 l = strlen(s); 2333 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) { 2334 is_utc = 1; 2335 l--; 2336 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) { 2337 is_utc = 1; 2338 l -= 3; 2339 } 2340 /* 2341 * POSIX strptime says "The application shall ensure that there 2342 * is white-space or other non-alphanumeric characters between 2343 * any two conversion specifications" so arrange things this way. 2344 */ 2345 switch (l) { 2346 case 8: /* YYYYMMDD */ 2347 fmt = "%Y-%m-%d"; 2348 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2349 break; 2350 case 12: /* YYYYMMDDHHMM */ 2351 fmt = "%Y-%m-%dT%H:%M"; 2352 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2353 s, s + 4, s + 6, s + 8, s + 10); 2354 break; 2355 case 14: /* YYYYMMDDHHMMSS */ 2356 fmt = "%Y-%m-%dT%H:%M:%S"; 2357 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2358 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2359 break; 2360 default: 2361 return SSH_ERR_INVALID_FORMAT; 2362 } 2363 2364 memset(&tm, 0, sizeof(tm)); 2365 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0') 2366 return SSH_ERR_INVALID_FORMAT; 2367 if (is_utc) { 2368 if ((tt = timegm(&tm)) < 0) 2369 return SSH_ERR_INVALID_FORMAT; 2370 } else { 2371 if ((tt = mktime(&tm)) < 0) 2372 return SSH_ERR_INVALID_FORMAT; 2373 } 2374 /* success */ 2375 *tp = (uint64_t)tt; 2376 return 0; 2377 } 2378 2379 void 2380 format_absolute_time(uint64_t t, char *buf, size_t len) 2381 { 2382 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2383 struct tm tm; 2384 2385 localtime_r(&tt, &tm); 2386 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2387 } 2388 2389 /* 2390 * Parse a "pattern=interval" clause (e.g. a ChannelTimeout). 2391 * Returns 0 on success or non-zero on failure. 2392 * Caller must free *typep. 2393 */ 2394 int 2395 parse_pattern_interval(const char *s, char **typep, int *secsp) 2396 { 2397 char *cp, *sdup; 2398 int secs; 2399 2400 if (typep != NULL) 2401 *typep = NULL; 2402 if (secsp != NULL) 2403 *secsp = 0; 2404 if (s == NULL) 2405 return -1; 2406 sdup = xstrdup(s); 2407 2408 if ((cp = strchr(sdup, '=')) == NULL || cp == sdup) { 2409 free(sdup); 2410 return -1; 2411 } 2412 *cp++ = '\0'; 2413 if ((secs = convtime(cp)) < 0) { 2414 free(sdup); 2415 return -1; 2416 } 2417 /* success */ 2418 if (typep != NULL) 2419 *typep = xstrdup(sdup); 2420 if (secsp != NULL) 2421 *secsp = secs; 2422 free(sdup); 2423 return 0; 2424 } 2425 2426 /* check if path is absolute */ 2427 int 2428 path_absolute(const char *path) 2429 { 2430 return (*path == '/') ? 1 : 0; 2431 } 2432 2433 void 2434 skip_space(char **cpp) 2435 { 2436 char *cp; 2437 2438 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2439 ; 2440 *cpp = cp; 2441 } 2442 2443 /* authorized_key-style options parsing helpers */ 2444 2445 /* 2446 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2447 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2448 * if negated option matches. 2449 * If the option or negated option matches, then *optsp is updated to 2450 * point to the first character after the option. 2451 */ 2452 int 2453 opt_flag(const char *opt, int allow_negate, const char **optsp) 2454 { 2455 size_t opt_len = strlen(opt); 2456 const char *opts = *optsp; 2457 int negate = 0; 2458 2459 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2460 opts += 3; 2461 negate = 1; 2462 } 2463 if (strncasecmp(opts, opt, opt_len) == 0) { 2464 *optsp = opts + opt_len; 2465 return negate ? 0 : 1; 2466 } 2467 return -1; 2468 } 2469 2470 char * 2471 opt_dequote(const char **sp, const char **errstrp) 2472 { 2473 const char *s = *sp; 2474 char *ret; 2475 size_t i; 2476 2477 *errstrp = NULL; 2478 if (*s != '"') { 2479 *errstrp = "missing start quote"; 2480 return NULL; 2481 } 2482 s++; 2483 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2484 *errstrp = "memory allocation failed"; 2485 return NULL; 2486 } 2487 for (i = 0; *s != '\0' && *s != '"';) { 2488 if (s[0] == '\\' && s[1] == '"') 2489 s++; 2490 ret[i++] = *s++; 2491 } 2492 if (*s == '\0') { 2493 *errstrp = "missing end quote"; 2494 free(ret); 2495 return NULL; 2496 } 2497 ret[i] = '\0'; 2498 s++; 2499 *sp = s; 2500 return ret; 2501 } 2502 2503 int 2504 opt_match(const char **opts, const char *term) 2505 { 2506 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2507 (*opts)[strlen(term)] == '=') { 2508 *opts += strlen(term) + 1; 2509 return 1; 2510 } 2511 return 0; 2512 } 2513 2514 void 2515 opt_array_append2(const char *file, const int line, const char *directive, 2516 char ***array, int **iarray, u_int *lp, const char *s, int i) 2517 { 2518 2519 if (*lp >= INT_MAX) 2520 fatal("%s line %d: Too many %s entries", file, line, directive); 2521 2522 if (iarray != NULL) { 2523 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2524 sizeof(**iarray)); 2525 (*iarray)[*lp] = i; 2526 } 2527 2528 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2529 (*array)[*lp] = xstrdup(s); 2530 (*lp)++; 2531 } 2532 2533 void 2534 opt_array_append(const char *file, const int line, const char *directive, 2535 char ***array, u_int *lp, const char *s) 2536 { 2537 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2538 } 2539 2540 sshsig_t 2541 ssh_signal(int signum, sshsig_t handler) 2542 { 2543 struct sigaction sa, osa; 2544 2545 /* mask all other signals while in handler */ 2546 memset(&sa, 0, sizeof(sa)); 2547 sa.sa_handler = handler; 2548 sigfillset(&sa.sa_mask); 2549 if (signum != SIGALRM) 2550 sa.sa_flags = SA_RESTART; 2551 if (sigaction(signum, &sa, &osa) == -1) { 2552 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2553 return SIG_ERR; 2554 } 2555 return osa.sa_handler; 2556 } 2557 2558 int 2559 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2560 { 2561 int devnull, ret = 0; 2562 2563 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2564 error_f("open %s: %s", _PATH_DEVNULL, 2565 strerror(errno)); 2566 return -1; 2567 } 2568 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2569 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2570 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2571 error_f("dup2: %s", strerror(errno)); 2572 ret = -1; 2573 } 2574 if (devnull > STDERR_FILENO) 2575 close(devnull); 2576 return ret; 2577 } 2578 2579 /* 2580 * Runs command in a subprocess with a minimal environment. 2581 * Returns pid on success, 0 on failure. 2582 * The child stdout and stderr maybe captured, left attached or sent to 2583 * /dev/null depending on the contents of flags. 2584 * "tag" is prepended to log messages. 2585 * NB. "command" is only used for logging; the actual command executed is 2586 * av[0]. 2587 */ 2588 pid_t 2589 subprocess(const char *tag, const char *command, 2590 int ac, char **av, FILE **child, u_int flags, 2591 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2592 { 2593 FILE *f = NULL; 2594 struct stat st; 2595 int fd, devnull, p[2], i; 2596 pid_t pid; 2597 char *cp, errmsg[512]; 2598 u_int nenv = 0; 2599 char **env = NULL; 2600 2601 /* If dropping privs, then must specify user and restore function */ 2602 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2603 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2604 return 0; 2605 } 2606 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2607 error("%s: no user for current uid", tag); 2608 return 0; 2609 } 2610 if (child != NULL) 2611 *child = NULL; 2612 2613 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2614 tag, command, pw->pw_name, flags); 2615 2616 /* Check consistency */ 2617 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2618 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2619 error_f("inconsistent flags"); 2620 return 0; 2621 } 2622 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2623 error_f("inconsistent flags/output"); 2624 return 0; 2625 } 2626 2627 /* 2628 * If executing an explicit binary, then verify the it exists 2629 * and appears safe-ish to execute 2630 */ 2631 if (!path_absolute(av[0])) { 2632 error("%s path is not absolute", tag); 2633 return 0; 2634 } 2635 if (drop_privs != NULL) 2636 drop_privs(pw); 2637 if (stat(av[0], &st) == -1) { 2638 error("Could not stat %s \"%s\": %s", tag, 2639 av[0], strerror(errno)); 2640 goto restore_return; 2641 } 2642 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2643 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2644 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2645 goto restore_return; 2646 } 2647 /* Prepare to keep the child's stdout if requested */ 2648 if (pipe(p) == -1) { 2649 error("%s: pipe: %s", tag, strerror(errno)); 2650 restore_return: 2651 if (restore_privs != NULL) 2652 restore_privs(); 2653 return 0; 2654 } 2655 if (restore_privs != NULL) 2656 restore_privs(); 2657 2658 switch ((pid = fork())) { 2659 case -1: /* error */ 2660 error("%s: fork: %s", tag, strerror(errno)); 2661 close(p[0]); 2662 close(p[1]); 2663 return 0; 2664 case 0: /* child */ 2665 /* Prepare a minimal environment for the child. */ 2666 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2667 nenv = 5; 2668 env = xcalloc(sizeof(*env), nenv); 2669 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2670 child_set_env(&env, &nenv, "USER", pw->pw_name); 2671 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2672 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2673 if ((cp = getenv("LANG")) != NULL) 2674 child_set_env(&env, &nenv, "LANG", cp); 2675 } 2676 2677 for (i = 1; i < NSIG; i++) 2678 ssh_signal(i, SIG_DFL); 2679 2680 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2681 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2682 strerror(errno)); 2683 _exit(1); 2684 } 2685 if (dup2(devnull, STDIN_FILENO) == -1) { 2686 error("%s: dup2: %s", tag, strerror(errno)); 2687 _exit(1); 2688 } 2689 2690 /* Set up stdout as requested; leave stderr in place for now. */ 2691 fd = -1; 2692 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2693 fd = p[1]; 2694 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2695 fd = devnull; 2696 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2697 error("%s: dup2: %s", tag, strerror(errno)); 2698 _exit(1); 2699 } 2700 closefrom(STDERR_FILENO + 1); 2701 2702 if (geteuid() == 0 && 2703 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2704 error("%s: initgroups(%s, %u): %s", tag, 2705 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2706 _exit(1); 2707 } 2708 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2709 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2710 strerror(errno)); 2711 _exit(1); 2712 } 2713 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2714 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2715 strerror(errno)); 2716 _exit(1); 2717 } 2718 /* stdin is pointed to /dev/null at this point */ 2719 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2720 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2721 error("%s: dup2: %s", tag, strerror(errno)); 2722 _exit(1); 2723 } 2724 if (env != NULL) 2725 execve(av[0], av, env); 2726 else 2727 execv(av[0], av); 2728 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2729 command, strerror(errno)); 2730 _exit(127); 2731 default: /* parent */ 2732 break; 2733 } 2734 2735 close(p[1]); 2736 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2737 close(p[0]); 2738 else if ((f = fdopen(p[0], "r")) == NULL) { 2739 error("%s: fdopen: %s", tag, strerror(errno)); 2740 close(p[0]); 2741 /* Don't leave zombie child */ 2742 kill(pid, SIGTERM); 2743 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2744 ; 2745 return 0; 2746 } 2747 /* Success */ 2748 debug3_f("%s pid %ld", tag, (long)pid); 2749 if (child != NULL) 2750 *child = f; 2751 return pid; 2752 } 2753 2754 const char * 2755 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2756 { 2757 size_t i, envlen; 2758 2759 envlen = strlen(env); 2760 for (i = 0; i < nenvs; i++) { 2761 if (strncmp(envs[i], env, envlen) == 0 && 2762 envs[i][envlen] == '=') { 2763 return envs[i] + envlen + 1; 2764 } 2765 } 2766 return NULL; 2767 } 2768 2769 const char * 2770 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs) 2771 { 2772 char *name, *cp; 2773 const char *ret; 2774 2775 name = xstrdup(env); 2776 if ((cp = strchr(name, '=')) == NULL) { 2777 free(name); 2778 return NULL; /* not env=val */ 2779 } 2780 *cp = '\0'; 2781 ret = lookup_env_in_list(name, envs, nenvs); 2782 free(name); 2783 return ret; 2784 } 2785 2786 /* 2787 * Helpers for managing poll(2)/ppoll(2) timeouts 2788 * Will remember the earliest deadline and return it for use in poll/ppoll. 2789 */ 2790 2791 /* Initialise a poll/ppoll timeout with an indefinite deadline */ 2792 void 2793 ptimeout_init(struct timespec *pt) 2794 { 2795 /* 2796 * Deliberately invalid for ppoll(2). 2797 * Will be converted to NULL in ptimeout_get_tspec() later. 2798 */ 2799 pt->tv_sec = -1; 2800 pt->tv_nsec = 0; 2801 } 2802 2803 /* Specify a poll/ppoll deadline of at most 'sec' seconds */ 2804 void 2805 ptimeout_deadline_sec(struct timespec *pt, long sec) 2806 { 2807 if (pt->tv_sec == -1 || pt->tv_sec >= sec) { 2808 pt->tv_sec = sec; 2809 pt->tv_nsec = 0; 2810 } 2811 } 2812 2813 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */ 2814 static void 2815 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p) 2816 { 2817 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=)) 2818 *pt = *p; 2819 } 2820 2821 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */ 2822 void 2823 ptimeout_deadline_ms(struct timespec *pt, long ms) 2824 { 2825 struct timespec p; 2826 2827 p.tv_sec = ms / 1000; 2828 p.tv_nsec = (ms % 1000) * 1000000; 2829 ptimeout_deadline_tsp(pt, &p); 2830 } 2831 2832 /* Specify a poll/ppoll deadline at wall clock monotime 'when' (timespec) */ 2833 void 2834 ptimeout_deadline_monotime_tsp(struct timespec *pt, struct timespec *when) 2835 { 2836 struct timespec now, t; 2837 2838 monotime_ts(&now); 2839 2840 if (timespeccmp(&now, when, >=)) { 2841 /* 'when' is now or in the past. Timeout ASAP */ 2842 pt->tv_sec = 0; 2843 pt->tv_nsec = 0; 2844 } else { 2845 timespecsub(when, &now, &t); 2846 ptimeout_deadline_tsp(pt, &t); 2847 } 2848 } 2849 2850 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */ 2851 void 2852 ptimeout_deadline_monotime(struct timespec *pt, time_t when) 2853 { 2854 struct timespec t; 2855 2856 t.tv_sec = when; 2857 t.tv_nsec = 0; 2858 ptimeout_deadline_monotime_tsp(pt, &t); 2859 } 2860 2861 /* Get a poll(2) timeout value in milliseconds */ 2862 int 2863 ptimeout_get_ms(struct timespec *pt) 2864 { 2865 if (pt->tv_sec == -1) 2866 return -1; 2867 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000) 2868 return INT_MAX; 2869 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000); 2870 } 2871 2872 /* Get a ppoll(2) timeout value as a timespec pointer */ 2873 struct timespec * 2874 ptimeout_get_tsp(struct timespec *pt) 2875 { 2876 return pt->tv_sec == -1 ? NULL : pt; 2877 } 2878 2879 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */ 2880 int 2881 ptimeout_isset(struct timespec *pt) 2882 { 2883 return pt->tv_sec != -1; 2884 } 2885 2886 /* 2887 * Returns zero if the library at 'path' contains symbol 's', nonzero 2888 * otherwise. 2889 */ 2890 int 2891 lib_contains_symbol(const char *path, const char *s) 2892 { 2893 struct nlist nl[2]; 2894 int ret = -1, r; 2895 2896 memset(nl, 0, sizeof(nl)); 2897 nl[0].n_name = xstrdup(s); 2898 nl[1].n_name = NULL; 2899 if ((r = nlist(path, nl)) == -1) { 2900 error_f("nlist failed for %s", path); 2901 goto out; 2902 } 2903 if (r != 0 || nl[0].n_value == 0 || nl[0].n_type == 0) { 2904 error_f("library %s does not contain symbol %s", path, s); 2905 goto out; 2906 } 2907 /* success */ 2908 ret = 0; 2909 out: 2910 free(nl[0].n_name); 2911 return ret; 2912 } 2913