1 /* $OpenBSD: misc.c,v 1.184 2023/07/19 14:02:27 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) 273 { 274 struct pollfd pfd; 275 struct timeval t_start; 276 int oerrno, r; 277 278 pfd.fd = fd; 279 pfd.events = events; 280 for (; *timeoutp >= 0;) { 281 monotime_tv(&t_start); 282 r = poll(&pfd, 1, *timeoutp); 283 oerrno = errno; 284 ms_subtract_diff(&t_start, timeoutp); 285 errno = oerrno; 286 if (r > 0) 287 return 0; 288 else if (r == -1 && errno != EAGAIN && errno != EINTR) 289 return -1; 290 else if (r == 0) 291 break; 292 } 293 /* timeout */ 294 errno = ETIMEDOUT; 295 return -1; 296 } 297 298 /* 299 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 300 * *timeoutp with time remaining. 301 * Returns 0 if fd ready or -1 on timeout or error (see errno). 302 */ 303 int 304 waitrfd(int fd, int *timeoutp) { 305 return waitfd(fd, timeoutp, POLLIN); 306 } 307 308 /* 309 * Attempt a non-blocking connect(2) to the specified address, waiting up to 310 * *timeoutp milliseconds for the connection to complete. If the timeout is 311 * <=0, then wait indefinitely. 312 * 313 * Returns 0 on success or -1 on failure. 314 */ 315 int 316 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 317 socklen_t addrlen, int *timeoutp) 318 { 319 int optval = 0; 320 socklen_t optlen = sizeof(optval); 321 322 /* No timeout: just do a blocking connect() */ 323 if (timeoutp == NULL || *timeoutp <= 0) 324 return connect(sockfd, serv_addr, addrlen); 325 326 set_nonblock(sockfd); 327 for (;;) { 328 if (connect(sockfd, serv_addr, addrlen) == 0) { 329 /* Succeeded already? */ 330 unset_nonblock(sockfd); 331 return 0; 332 } else if (errno == EINTR) 333 continue; 334 else if (errno != EINPROGRESS) 335 return -1; 336 break; 337 } 338 339 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) 340 return -1; 341 342 /* Completed or failed */ 343 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 344 debug("getsockopt: %s", strerror(errno)); 345 return -1; 346 } 347 if (optval != 0) { 348 errno = optval; 349 return -1; 350 } 351 unset_nonblock(sockfd); 352 return 0; 353 } 354 355 /* Characters considered whitespace in strsep calls. */ 356 #define WHITESPACE " \t\r\n" 357 #define QUOTE "\"" 358 359 /* return next token in configuration line */ 360 static char * 361 strdelim_internal(char **s, int split_equals) 362 { 363 char *old; 364 int wspace = 0; 365 366 if (*s == NULL) 367 return NULL; 368 369 old = *s; 370 371 *s = strpbrk(*s, 372 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 373 if (*s == NULL) 374 return (old); 375 376 if (*s[0] == '\"') { 377 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 378 /* Find matching quote */ 379 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 380 return (NULL); /* no matching quote */ 381 } else { 382 *s[0] = '\0'; 383 *s += strspn(*s + 1, WHITESPACE) + 1; 384 return (old); 385 } 386 } 387 388 /* Allow only one '=' to be skipped */ 389 if (split_equals && *s[0] == '=') 390 wspace = 1; 391 *s[0] = '\0'; 392 393 /* Skip any extra whitespace after first token */ 394 *s += strspn(*s + 1, WHITESPACE) + 1; 395 if (split_equals && *s[0] == '=' && !wspace) 396 *s += strspn(*s + 1, WHITESPACE) + 1; 397 398 return (old); 399 } 400 401 /* 402 * Return next token in configuration line; splts on whitespace or a 403 * single '=' character. 404 */ 405 char * 406 strdelim(char **s) 407 { 408 return strdelim_internal(s, 1); 409 } 410 411 /* 412 * Return next token in configuration line; splts on whitespace only. 413 */ 414 char * 415 strdelimw(char **s) 416 { 417 return strdelim_internal(s, 0); 418 } 419 420 struct passwd * 421 pwcopy(struct passwd *pw) 422 { 423 struct passwd *copy = xcalloc(1, sizeof(*copy)); 424 425 copy->pw_name = xstrdup(pw->pw_name); 426 copy->pw_passwd = xstrdup(pw->pw_passwd); 427 copy->pw_gecos = xstrdup(pw->pw_gecos); 428 copy->pw_uid = pw->pw_uid; 429 copy->pw_gid = pw->pw_gid; 430 copy->pw_expire = pw->pw_expire; 431 copy->pw_change = pw->pw_change; 432 copy->pw_class = xstrdup(pw->pw_class); 433 copy->pw_dir = xstrdup(pw->pw_dir); 434 copy->pw_shell = xstrdup(pw->pw_shell); 435 return copy; 436 } 437 438 /* 439 * Convert ASCII string to TCP/IP port number. 440 * Port must be >=0 and <=65535. 441 * Return -1 if invalid. 442 */ 443 int 444 a2port(const char *s) 445 { 446 struct servent *se; 447 long long port; 448 const char *errstr; 449 450 port = strtonum(s, 0, 65535, &errstr); 451 if (errstr == NULL) 452 return (int)port; 453 if ((se = getservbyname(s, "tcp")) != NULL) 454 return ntohs(se->s_port); 455 return -1; 456 } 457 458 int 459 a2tun(const char *s, int *remote) 460 { 461 const char *errstr = NULL; 462 char *sp, *ep; 463 int tun; 464 465 if (remote != NULL) { 466 *remote = SSH_TUNID_ANY; 467 sp = xstrdup(s); 468 if ((ep = strchr(sp, ':')) == NULL) { 469 free(sp); 470 return (a2tun(s, NULL)); 471 } 472 ep[0] = '\0'; ep++; 473 *remote = a2tun(ep, NULL); 474 tun = a2tun(sp, NULL); 475 free(sp); 476 return (*remote == SSH_TUNID_ERR ? *remote : tun); 477 } 478 479 if (strcasecmp(s, "any") == 0) 480 return (SSH_TUNID_ANY); 481 482 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 483 if (errstr != NULL) 484 return (SSH_TUNID_ERR); 485 486 return (tun); 487 } 488 489 #define SECONDS 1 490 #define MINUTES (SECONDS * 60) 491 #define HOURS (MINUTES * 60) 492 #define DAYS (HOURS * 24) 493 #define WEEKS (DAYS * 7) 494 495 /* 496 * Convert a time string into seconds; format is 497 * a sequence of: 498 * time[qualifier] 499 * 500 * Valid time qualifiers are: 501 * <none> seconds 502 * s|S seconds 503 * m|M minutes 504 * h|H hours 505 * d|D days 506 * w|W weeks 507 * 508 * Examples: 509 * 90m 90 minutes 510 * 1h30m 90 minutes 511 * 2d 2 days 512 * 1w 1 week 513 * 514 * Return -1 if time string is invalid. 515 */ 516 int 517 convtime(const char *s) 518 { 519 long total, secs, multiplier; 520 const char *p; 521 char *endp; 522 523 errno = 0; 524 total = 0; 525 p = s; 526 527 if (p == NULL || *p == '\0') 528 return -1; 529 530 while (*p) { 531 secs = strtol(p, &endp, 10); 532 if (p == endp || 533 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 534 secs < 0) 535 return -1; 536 537 multiplier = 1; 538 switch (*endp++) { 539 case '\0': 540 endp--; 541 break; 542 case 's': 543 case 'S': 544 break; 545 case 'm': 546 case 'M': 547 multiplier = MINUTES; 548 break; 549 case 'h': 550 case 'H': 551 multiplier = HOURS; 552 break; 553 case 'd': 554 case 'D': 555 multiplier = DAYS; 556 break; 557 case 'w': 558 case 'W': 559 multiplier = WEEKS; 560 break; 561 default: 562 return -1; 563 } 564 if (secs > INT_MAX / multiplier) 565 return -1; 566 secs *= multiplier; 567 if (total > INT_MAX - secs) 568 return -1; 569 total += secs; 570 if (total < 0) 571 return -1; 572 p = endp; 573 } 574 575 return total; 576 } 577 578 #define TF_BUFS 8 579 #define TF_LEN 9 580 581 const char * 582 fmt_timeframe(time_t t) 583 { 584 char *buf; 585 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 586 static int idx = 0; 587 unsigned int sec, min, hrs, day; 588 unsigned long long week; 589 590 buf = tfbuf[idx++]; 591 if (idx == TF_BUFS) 592 idx = 0; 593 594 week = t; 595 596 sec = week % 60; 597 week /= 60; 598 min = week % 60; 599 week /= 60; 600 hrs = week % 24; 601 week /= 24; 602 day = week % 7; 603 week /= 7; 604 605 if (week > 0) 606 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 607 else if (day > 0) 608 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 609 else 610 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 611 612 return (buf); 613 } 614 615 /* 616 * Returns a standardized host+port identifier string. 617 * Caller must free returned string. 618 */ 619 char * 620 put_host_port(const char *host, u_short port) 621 { 622 char *hoststr; 623 624 if (port == 0 || port == SSH_DEFAULT_PORT) 625 return(xstrdup(host)); 626 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 627 fatal("put_host_port: asprintf: %s", strerror(errno)); 628 debug3("put_host_port: %s", hoststr); 629 return hoststr; 630 } 631 632 /* 633 * Search for next delimiter between hostnames/addresses and ports. 634 * Argument may be modified (for termination). 635 * Returns *cp if parsing succeeds. 636 * *cp is set to the start of the next field, if one was found. 637 * The delimiter char, if present, is stored in delim. 638 * If this is the last field, *cp is set to NULL. 639 */ 640 char * 641 hpdelim2(char **cp, char *delim) 642 { 643 char *s, *old; 644 645 if (cp == NULL || *cp == NULL) 646 return NULL; 647 648 old = s = *cp; 649 if (*s == '[') { 650 if ((s = strchr(s, ']')) == NULL) 651 return NULL; 652 else 653 s++; 654 } else if ((s = strpbrk(s, ":/")) == NULL) 655 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 656 657 switch (*s) { 658 case '\0': 659 *cp = NULL; /* no more fields*/ 660 break; 661 662 case ':': 663 case '/': 664 if (delim != NULL) 665 *delim = *s; 666 *s = '\0'; /* terminate */ 667 *cp = s + 1; 668 break; 669 670 default: 671 return NULL; 672 } 673 674 return old; 675 } 676 677 /* The common case: only accept colon as delimiter. */ 678 char * 679 hpdelim(char **cp) 680 { 681 char *r, delim = '\0'; 682 683 r = hpdelim2(cp, &delim); 684 if (delim == '/') 685 return NULL; 686 return r; 687 } 688 689 char * 690 cleanhostname(char *host) 691 { 692 if (*host == '[' && host[strlen(host) - 1] == ']') { 693 host[strlen(host) - 1] = '\0'; 694 return (host + 1); 695 } else 696 return host; 697 } 698 699 char * 700 colon(char *cp) 701 { 702 int flag = 0; 703 704 if (*cp == ':') /* Leading colon is part of file name. */ 705 return NULL; 706 if (*cp == '[') 707 flag = 1; 708 709 for (; *cp; ++cp) { 710 if (*cp == '@' && *(cp+1) == '[') 711 flag = 1; 712 if (*cp == ']' && *(cp+1) == ':' && flag) 713 return (cp+1); 714 if (*cp == ':' && !flag) 715 return (cp); 716 if (*cp == '/') 717 return NULL; 718 } 719 return NULL; 720 } 721 722 /* 723 * Parse a [user@]host:[path] string. 724 * Caller must free returned user, host and path. 725 * Any of the pointer return arguments may be NULL (useful for syntax checking). 726 * If user was not specified then *userp will be set to NULL. 727 * If host was not specified then *hostp will be set to NULL. 728 * If path was not specified then *pathp will be set to ".". 729 * Returns 0 on success, -1 on failure. 730 */ 731 int 732 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 733 { 734 char *user = NULL, *host = NULL, *path = NULL; 735 char *sdup, *tmp; 736 int ret = -1; 737 738 if (userp != NULL) 739 *userp = NULL; 740 if (hostp != NULL) 741 *hostp = NULL; 742 if (pathp != NULL) 743 *pathp = NULL; 744 745 sdup = xstrdup(s); 746 747 /* Check for remote syntax: [user@]host:[path] */ 748 if ((tmp = colon(sdup)) == NULL) 749 goto out; 750 751 /* Extract optional path */ 752 *tmp++ = '\0'; 753 if (*tmp == '\0') 754 tmp = "."; 755 path = xstrdup(tmp); 756 757 /* Extract optional user and mandatory host */ 758 tmp = strrchr(sdup, '@'); 759 if (tmp != NULL) { 760 *tmp++ = '\0'; 761 host = xstrdup(cleanhostname(tmp)); 762 if (*sdup != '\0') 763 user = xstrdup(sdup); 764 } else { 765 host = xstrdup(cleanhostname(sdup)); 766 user = NULL; 767 } 768 769 /* Success */ 770 if (userp != NULL) { 771 *userp = user; 772 user = NULL; 773 } 774 if (hostp != NULL) { 775 *hostp = host; 776 host = NULL; 777 } 778 if (pathp != NULL) { 779 *pathp = path; 780 path = NULL; 781 } 782 ret = 0; 783 out: 784 free(sdup); 785 free(user); 786 free(host); 787 free(path); 788 return ret; 789 } 790 791 /* 792 * Parse a [user@]host[:port] string. 793 * Caller must free returned user and host. 794 * Any of the pointer return arguments may be NULL (useful for syntax checking). 795 * If user was not specified then *userp will be set to NULL. 796 * If port was not specified then *portp will be -1. 797 * Returns 0 on success, -1 on failure. 798 */ 799 int 800 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 801 { 802 char *sdup, *cp, *tmp; 803 char *user = NULL, *host = NULL; 804 int port = -1, ret = -1; 805 806 if (userp != NULL) 807 *userp = NULL; 808 if (hostp != NULL) 809 *hostp = NULL; 810 if (portp != NULL) 811 *portp = -1; 812 813 if ((sdup = tmp = strdup(s)) == NULL) 814 return -1; 815 /* Extract optional username */ 816 if ((cp = strrchr(tmp, '@')) != NULL) { 817 *cp = '\0'; 818 if (*tmp == '\0') 819 goto out; 820 if ((user = strdup(tmp)) == NULL) 821 goto out; 822 tmp = cp + 1; 823 } 824 /* Extract mandatory hostname */ 825 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 826 goto out; 827 host = xstrdup(cleanhostname(cp)); 828 /* Convert and verify optional port */ 829 if (tmp != NULL && *tmp != '\0') { 830 if ((port = a2port(tmp)) <= 0) 831 goto out; 832 } 833 /* Success */ 834 if (userp != NULL) { 835 *userp = user; 836 user = NULL; 837 } 838 if (hostp != NULL) { 839 *hostp = host; 840 host = NULL; 841 } 842 if (portp != NULL) 843 *portp = port; 844 ret = 0; 845 out: 846 free(sdup); 847 free(user); 848 free(host); 849 return ret; 850 } 851 852 /* 853 * Converts a two-byte hex string to decimal. 854 * Returns the decimal value or -1 for invalid input. 855 */ 856 static int 857 hexchar(const char *s) 858 { 859 unsigned char result[2]; 860 int i; 861 862 for (i = 0; i < 2; i++) { 863 if (s[i] >= '0' && s[i] <= '9') 864 result[i] = (unsigned char)(s[i] - '0'); 865 else if (s[i] >= 'a' && s[i] <= 'f') 866 result[i] = (unsigned char)(s[i] - 'a') + 10; 867 else if (s[i] >= 'A' && s[i] <= 'F') 868 result[i] = (unsigned char)(s[i] - 'A') + 10; 869 else 870 return -1; 871 } 872 return (result[0] << 4) | result[1]; 873 } 874 875 /* 876 * Decode an url-encoded string. 877 * Returns a newly allocated string on success or NULL on failure. 878 */ 879 static char * 880 urldecode(const char *src) 881 { 882 char *ret, *dst; 883 int ch; 884 size_t srclen; 885 886 if ((srclen = strlen(src)) >= SIZE_MAX) 887 fatal_f("input too large"); 888 ret = xmalloc(srclen + 1); 889 for (dst = ret; *src != '\0'; src++) { 890 switch (*src) { 891 case '+': 892 *dst++ = ' '; 893 break; 894 case '%': 895 if (!isxdigit((unsigned char)src[1]) || 896 !isxdigit((unsigned char)src[2]) || 897 (ch = hexchar(src + 1)) == -1) { 898 free(ret); 899 return NULL; 900 } 901 *dst++ = ch; 902 src += 2; 903 break; 904 default: 905 *dst++ = *src; 906 break; 907 } 908 } 909 *dst = '\0'; 910 911 return ret; 912 } 913 914 /* 915 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 916 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 917 * Either user or path may be url-encoded (but not host or port). 918 * Caller must free returned user, host and path. 919 * Any of the pointer return arguments may be NULL (useful for syntax checking) 920 * but the scheme must always be specified. 921 * If user was not specified then *userp will be set to NULL. 922 * If port was not specified then *portp will be -1. 923 * If path was not specified then *pathp will be set to NULL. 924 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 925 */ 926 int 927 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 928 int *portp, char **pathp) 929 { 930 char *uridup, *cp, *tmp, ch; 931 char *user = NULL, *host = NULL, *path = NULL; 932 int port = -1, ret = -1; 933 size_t len; 934 935 len = strlen(scheme); 936 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 937 return 1; 938 uri += len + 3; 939 940 if (userp != NULL) 941 *userp = NULL; 942 if (hostp != NULL) 943 *hostp = NULL; 944 if (portp != NULL) 945 *portp = -1; 946 if (pathp != NULL) 947 *pathp = NULL; 948 949 uridup = tmp = xstrdup(uri); 950 951 /* Extract optional ssh-info (username + connection params) */ 952 if ((cp = strchr(tmp, '@')) != NULL) { 953 char *delim; 954 955 *cp = '\0'; 956 /* Extract username and connection params */ 957 if ((delim = strchr(tmp, ';')) != NULL) { 958 /* Just ignore connection params for now */ 959 *delim = '\0'; 960 } 961 if (*tmp == '\0') { 962 /* Empty username */ 963 goto out; 964 } 965 if ((user = urldecode(tmp)) == NULL) 966 goto out; 967 tmp = cp + 1; 968 } 969 970 /* Extract mandatory hostname */ 971 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 972 goto out; 973 host = xstrdup(cleanhostname(cp)); 974 if (!valid_domain(host, 0, NULL)) 975 goto out; 976 977 if (tmp != NULL && *tmp != '\0') { 978 if (ch == ':') { 979 /* Convert and verify port. */ 980 if ((cp = strchr(tmp, '/')) != NULL) 981 *cp = '\0'; 982 if ((port = a2port(tmp)) <= 0) 983 goto out; 984 tmp = cp ? cp + 1 : NULL; 985 } 986 if (tmp != NULL && *tmp != '\0') { 987 /* Extract optional path */ 988 if ((path = urldecode(tmp)) == NULL) 989 goto out; 990 } 991 } 992 993 /* Success */ 994 if (userp != NULL) { 995 *userp = user; 996 user = NULL; 997 } 998 if (hostp != NULL) { 999 *hostp = host; 1000 host = NULL; 1001 } 1002 if (portp != NULL) 1003 *portp = port; 1004 if (pathp != NULL) { 1005 *pathp = path; 1006 path = NULL; 1007 } 1008 ret = 0; 1009 out: 1010 free(uridup); 1011 free(user); 1012 free(host); 1013 free(path); 1014 return ret; 1015 } 1016 1017 /* function to assist building execv() arguments */ 1018 void 1019 addargs(arglist *args, char *fmt, ...) 1020 { 1021 va_list ap; 1022 char *cp; 1023 u_int nalloc; 1024 int r; 1025 1026 va_start(ap, fmt); 1027 r = vasprintf(&cp, fmt, ap); 1028 va_end(ap); 1029 if (r == -1) 1030 fatal_f("argument too long"); 1031 1032 nalloc = args->nalloc; 1033 if (args->list == NULL) { 1034 nalloc = 32; 1035 args->num = 0; 1036 } else if (args->num > (256 * 1024)) 1037 fatal_f("too many arguments"); 1038 else if (args->num >= args->nalloc) 1039 fatal_f("arglist corrupt"); 1040 else if (args->num+2 >= nalloc) 1041 nalloc *= 2; 1042 1043 args->list = xrecallocarray(args->list, args->nalloc, 1044 nalloc, sizeof(char *)); 1045 args->nalloc = nalloc; 1046 args->list[args->num++] = cp; 1047 args->list[args->num] = NULL; 1048 } 1049 1050 void 1051 replacearg(arglist *args, u_int which, char *fmt, ...) 1052 { 1053 va_list ap; 1054 char *cp; 1055 int r; 1056 1057 va_start(ap, fmt); 1058 r = vasprintf(&cp, fmt, ap); 1059 va_end(ap); 1060 if (r == -1) 1061 fatal_f("argument too long"); 1062 if (args->list == NULL || args->num >= args->nalloc) 1063 fatal_f("arglist corrupt"); 1064 1065 if (which >= args->num) 1066 fatal_f("tried to replace invalid arg %d >= %d", 1067 which, args->num); 1068 free(args->list[which]); 1069 args->list[which] = cp; 1070 } 1071 1072 void 1073 freeargs(arglist *args) 1074 { 1075 u_int i; 1076 1077 if (args == NULL) 1078 return; 1079 if (args->list != NULL && args->num < args->nalloc) { 1080 for (i = 0; i < args->num; i++) 1081 free(args->list[i]); 1082 free(args->list); 1083 } 1084 args->nalloc = args->num = 0; 1085 args->list = NULL; 1086 } 1087 1088 /* 1089 * Expands tildes in the file name. Returns data allocated by xmalloc. 1090 * Warning: this calls getpw*. 1091 */ 1092 int 1093 tilde_expand(const char *filename, uid_t uid, char **retp) 1094 { 1095 char *ocopy = NULL, *copy, *s = NULL; 1096 const char *path = NULL, *user = NULL; 1097 struct passwd *pw; 1098 size_t len; 1099 int ret = -1, r, slash; 1100 1101 *retp = NULL; 1102 if (*filename != '~') { 1103 *retp = xstrdup(filename); 1104 return 0; 1105 } 1106 ocopy = copy = xstrdup(filename + 1); 1107 1108 if (*copy == '\0') /* ~ */ 1109 path = NULL; 1110 else if (*copy == '/') { 1111 copy += strspn(copy, "/"); 1112 if (*copy == '\0') 1113 path = NULL; /* ~/ */ 1114 else 1115 path = copy; /* ~/path */ 1116 } else { 1117 user = copy; 1118 if ((path = strchr(copy, '/')) != NULL) { 1119 copy[path - copy] = '\0'; 1120 path++; 1121 path += strspn(path, "/"); 1122 if (*path == '\0') /* ~user/ */ 1123 path = NULL; 1124 /* else ~user/path */ 1125 } 1126 /* else ~user */ 1127 } 1128 if (user != NULL) { 1129 if ((pw = getpwnam(user)) == NULL) { 1130 error_f("No such user %s", user); 1131 goto out; 1132 } 1133 } else if ((pw = getpwuid(uid)) == NULL) { 1134 error_f("No such uid %ld", (long)uid); 1135 goto out; 1136 } 1137 1138 /* Make sure directory has a trailing '/' */ 1139 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1140 1141 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1142 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1143 error_f("xasprintf failed"); 1144 goto out; 1145 } 1146 if (r >= PATH_MAX) { 1147 error_f("Path too long"); 1148 goto out; 1149 } 1150 /* success */ 1151 ret = 0; 1152 *retp = s; 1153 s = NULL; 1154 out: 1155 free(s); 1156 free(ocopy); 1157 return ret; 1158 } 1159 1160 char * 1161 tilde_expand_filename(const char *filename, uid_t uid) 1162 { 1163 char *ret; 1164 1165 if (tilde_expand(filename, uid, &ret) != 0) 1166 cleanup_exit(255); 1167 return ret; 1168 } 1169 1170 /* 1171 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1172 * substitutions. A number of escapes may be specified as 1173 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1174 * by a NULL escape_char. Returns replaced string in memory allocated by 1175 * xmalloc which the caller must free. 1176 */ 1177 static char * 1178 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1179 const char *string, va_list ap) 1180 { 1181 #define EXPAND_MAX_KEYS 16 1182 u_int num_keys = 0, i; 1183 struct { 1184 const char *key; 1185 const char *repl; 1186 } keys[EXPAND_MAX_KEYS]; 1187 struct sshbuf *buf; 1188 int r, missingvar = 0; 1189 char *ret = NULL, *var, *varend, *val; 1190 size_t len; 1191 1192 if ((buf = sshbuf_new()) == NULL) 1193 fatal_f("sshbuf_new failed"); 1194 if (parseerror == NULL) 1195 fatal_f("null parseerror arg"); 1196 *parseerror = 1; 1197 1198 /* Gather keys if we're doing percent expansion. */ 1199 if (percent) { 1200 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1201 keys[num_keys].key = va_arg(ap, char *); 1202 if (keys[num_keys].key == NULL) 1203 break; 1204 keys[num_keys].repl = va_arg(ap, char *); 1205 if (keys[num_keys].repl == NULL) { 1206 fatal_f("NULL replacement for token %s", 1207 keys[num_keys].key); 1208 } 1209 } 1210 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1211 fatal_f("too many keys"); 1212 if (num_keys == 0) 1213 fatal_f("percent expansion without token list"); 1214 } 1215 1216 /* Expand string */ 1217 for (i = 0; *string != '\0'; string++) { 1218 /* Optionally process ${ENVIRONMENT} expansions. */ 1219 if (dollar && string[0] == '$' && string[1] == '{') { 1220 string += 2; /* skip over '${' */ 1221 if ((varend = strchr(string, '}')) == NULL) { 1222 error_f("environment variable '%s' missing " 1223 "closing '}'", string); 1224 goto out; 1225 } 1226 len = varend - string; 1227 if (len == 0) { 1228 error_f("zero-length environment variable"); 1229 goto out; 1230 } 1231 var = xmalloc(len + 1); 1232 (void)strlcpy(var, string, len + 1); 1233 if ((val = getenv(var)) == NULL) { 1234 error_f("env var ${%s} has no value", var); 1235 missingvar = 1; 1236 } else { 1237 debug3_f("expand ${%s} -> '%s'", var, val); 1238 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1239 fatal_fr(r, "sshbuf_put ${}"); 1240 } 1241 free(var); 1242 string += len; 1243 continue; 1244 } 1245 1246 /* 1247 * Process percent expansions if we have a list of TOKENs. 1248 * If we're not doing percent expansion everything just gets 1249 * appended here. 1250 */ 1251 if (*string != '%' || !percent) { 1252 append: 1253 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1254 fatal_fr(r, "sshbuf_put_u8 %%"); 1255 continue; 1256 } 1257 string++; 1258 /* %% case */ 1259 if (*string == '%') 1260 goto append; 1261 if (*string == '\0') { 1262 error_f("invalid format"); 1263 goto out; 1264 } 1265 for (i = 0; i < num_keys; i++) { 1266 if (strchr(keys[i].key, *string) != NULL) { 1267 if ((r = sshbuf_put(buf, keys[i].repl, 1268 strlen(keys[i].repl))) != 0) 1269 fatal_fr(r, "sshbuf_put %%-repl"); 1270 break; 1271 } 1272 } 1273 if (i >= num_keys) { 1274 error_f("unknown key %%%c", *string); 1275 goto out; 1276 } 1277 } 1278 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1279 fatal_f("sshbuf_dup_string failed"); 1280 *parseerror = 0; 1281 out: 1282 sshbuf_free(buf); 1283 return *parseerror ? NULL : ret; 1284 #undef EXPAND_MAX_KEYS 1285 } 1286 1287 /* 1288 * Expand only environment variables. 1289 * Note that although this function is variadic like the other similar 1290 * functions, any such arguments will be unused. 1291 */ 1292 1293 char * 1294 dollar_expand(int *parseerr, const char *string, ...) 1295 { 1296 char *ret; 1297 int err; 1298 va_list ap; 1299 1300 va_start(ap, string); 1301 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1302 va_end(ap); 1303 if (parseerr != NULL) 1304 *parseerr = err; 1305 return ret; 1306 } 1307 1308 /* 1309 * Returns expanded string or NULL if a specified environment variable is 1310 * not defined, or calls fatal if the string is invalid. 1311 */ 1312 char * 1313 percent_expand(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, 0, 1, string, ap); 1321 va_end(ap); 1322 if (err) 1323 fatal_f("failed"); 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_dollar_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, 1, 1, string, ap); 1340 va_end(ap); 1341 if (err) 1342 fatal_f("failed"); 1343 return ret; 1344 } 1345 1346 int 1347 tun_open(int tun, int mode, char **ifname) 1348 { 1349 struct ifreq ifr; 1350 char name[100]; 1351 int fd = -1, sock; 1352 const char *tunbase = "tun"; 1353 1354 if (ifname != NULL) 1355 *ifname = NULL; 1356 1357 if (mode == SSH_TUNMODE_ETHERNET) 1358 tunbase = "tap"; 1359 1360 /* Open the tunnel device */ 1361 if (tun <= SSH_TUNID_MAX) { 1362 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1363 fd = open(name, O_RDWR); 1364 } else if (tun == SSH_TUNID_ANY) { 1365 for (tun = 100; tun >= 0; tun--) { 1366 snprintf(name, sizeof(name), "/dev/%s%d", 1367 tunbase, tun); 1368 if ((fd = open(name, O_RDWR)) >= 0) 1369 break; 1370 } 1371 } else { 1372 debug_f("invalid tunnel %u", tun); 1373 return -1; 1374 } 1375 1376 if (fd == -1) { 1377 debug_f("%s open: %s", name, strerror(errno)); 1378 return -1; 1379 } 1380 1381 debug_f("%s mode %d fd %d", name, mode, fd); 1382 1383 /* Bring interface up if it is not already */ 1384 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1385 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1386 goto failed; 1387 1388 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1389 debug_f("get interface %s flags: %s", ifr.ifr_name, 1390 strerror(errno)); 1391 goto failed; 1392 } 1393 1394 if (!(ifr.ifr_flags & IFF_UP)) { 1395 ifr.ifr_flags |= IFF_UP; 1396 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1397 debug_f("activate interface %s: %s", ifr.ifr_name, 1398 strerror(errno)); 1399 goto failed; 1400 } 1401 } 1402 1403 if (ifname != NULL) 1404 *ifname = xstrdup(ifr.ifr_name); 1405 1406 close(sock); 1407 return fd; 1408 1409 failed: 1410 if (fd >= 0) 1411 close(fd); 1412 if (sock >= 0) 1413 close(sock); 1414 return -1; 1415 } 1416 1417 void 1418 sanitise_stdfd(void) 1419 { 1420 int nullfd, dupfd; 1421 1422 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1423 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1424 strerror(errno)); 1425 exit(1); 1426 } 1427 while (++dupfd <= STDERR_FILENO) { 1428 /* Only populate closed fds. */ 1429 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1430 if (dup2(nullfd, dupfd) == -1) { 1431 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1432 exit(1); 1433 } 1434 } 1435 } 1436 if (nullfd > STDERR_FILENO) 1437 close(nullfd); 1438 } 1439 1440 char * 1441 tohex(const void *vp, size_t l) 1442 { 1443 const u_char *p = (const u_char *)vp; 1444 char b[3], *r; 1445 size_t i, hl; 1446 1447 if (l > 65536) 1448 return xstrdup("tohex: length > 65536"); 1449 1450 hl = l * 2 + 1; 1451 r = xcalloc(1, hl); 1452 for (i = 0; i < l; i++) { 1453 snprintf(b, sizeof(b), "%02x", p[i]); 1454 strlcat(r, b, hl); 1455 } 1456 return (r); 1457 } 1458 1459 /* 1460 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1461 * then the separator 'sep' will be prepended before the formatted arguments. 1462 * Extended strings are heap allocated. 1463 */ 1464 void 1465 xextendf(char **sp, const char *sep, const char *fmt, ...) 1466 { 1467 va_list ap; 1468 char *tmp1, *tmp2; 1469 1470 va_start(ap, fmt); 1471 xvasprintf(&tmp1, fmt, ap); 1472 va_end(ap); 1473 1474 if (*sp == NULL || **sp == '\0') { 1475 free(*sp); 1476 *sp = tmp1; 1477 return; 1478 } 1479 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1480 free(tmp1); 1481 free(*sp); 1482 *sp = tmp2; 1483 } 1484 1485 1486 u_int64_t 1487 get_u64(const void *vp) 1488 { 1489 const u_char *p = (const u_char *)vp; 1490 u_int64_t v; 1491 1492 v = (u_int64_t)p[0] << 56; 1493 v |= (u_int64_t)p[1] << 48; 1494 v |= (u_int64_t)p[2] << 40; 1495 v |= (u_int64_t)p[3] << 32; 1496 v |= (u_int64_t)p[4] << 24; 1497 v |= (u_int64_t)p[5] << 16; 1498 v |= (u_int64_t)p[6] << 8; 1499 v |= (u_int64_t)p[7]; 1500 1501 return (v); 1502 } 1503 1504 u_int32_t 1505 get_u32(const void *vp) 1506 { 1507 const u_char *p = (const u_char *)vp; 1508 u_int32_t v; 1509 1510 v = (u_int32_t)p[0] << 24; 1511 v |= (u_int32_t)p[1] << 16; 1512 v |= (u_int32_t)p[2] << 8; 1513 v |= (u_int32_t)p[3]; 1514 1515 return (v); 1516 } 1517 1518 u_int32_t 1519 get_u32_le(const void *vp) 1520 { 1521 const u_char *p = (const u_char *)vp; 1522 u_int32_t v; 1523 1524 v = (u_int32_t)p[0]; 1525 v |= (u_int32_t)p[1] << 8; 1526 v |= (u_int32_t)p[2] << 16; 1527 v |= (u_int32_t)p[3] << 24; 1528 1529 return (v); 1530 } 1531 1532 u_int16_t 1533 get_u16(const void *vp) 1534 { 1535 const u_char *p = (const u_char *)vp; 1536 u_int16_t v; 1537 1538 v = (u_int16_t)p[0] << 8; 1539 v |= (u_int16_t)p[1]; 1540 1541 return (v); 1542 } 1543 1544 void 1545 put_u64(void *vp, u_int64_t v) 1546 { 1547 u_char *p = (u_char *)vp; 1548 1549 p[0] = (u_char)(v >> 56) & 0xff; 1550 p[1] = (u_char)(v >> 48) & 0xff; 1551 p[2] = (u_char)(v >> 40) & 0xff; 1552 p[3] = (u_char)(v >> 32) & 0xff; 1553 p[4] = (u_char)(v >> 24) & 0xff; 1554 p[5] = (u_char)(v >> 16) & 0xff; 1555 p[6] = (u_char)(v >> 8) & 0xff; 1556 p[7] = (u_char)v & 0xff; 1557 } 1558 1559 void 1560 put_u32(void *vp, u_int32_t v) 1561 { 1562 u_char *p = (u_char *)vp; 1563 1564 p[0] = (u_char)(v >> 24) & 0xff; 1565 p[1] = (u_char)(v >> 16) & 0xff; 1566 p[2] = (u_char)(v >> 8) & 0xff; 1567 p[3] = (u_char)v & 0xff; 1568 } 1569 1570 void 1571 put_u32_le(void *vp, u_int32_t v) 1572 { 1573 u_char *p = (u_char *)vp; 1574 1575 p[0] = (u_char)v & 0xff; 1576 p[1] = (u_char)(v >> 8) & 0xff; 1577 p[2] = (u_char)(v >> 16) & 0xff; 1578 p[3] = (u_char)(v >> 24) & 0xff; 1579 } 1580 1581 void 1582 put_u16(void *vp, u_int16_t v) 1583 { 1584 u_char *p = (u_char *)vp; 1585 1586 p[0] = (u_char)(v >> 8) & 0xff; 1587 p[1] = (u_char)v & 0xff; 1588 } 1589 1590 void 1591 ms_subtract_diff(struct timeval *start, int *ms) 1592 { 1593 struct timeval diff, finish; 1594 1595 monotime_tv(&finish); 1596 timersub(&finish, start, &diff); 1597 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1598 } 1599 1600 void 1601 ms_to_timespec(struct timespec *ts, int ms) 1602 { 1603 if (ms < 0) 1604 ms = 0; 1605 ts->tv_sec = ms / 1000; 1606 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1607 } 1608 1609 void 1610 monotime_ts(struct timespec *ts) 1611 { 1612 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1613 fatal("clock_gettime: %s", strerror(errno)); 1614 } 1615 1616 void 1617 monotime_tv(struct timeval *tv) 1618 { 1619 struct timespec ts; 1620 1621 monotime_ts(&ts); 1622 tv->tv_sec = ts.tv_sec; 1623 tv->tv_usec = ts.tv_nsec / 1000; 1624 } 1625 1626 time_t 1627 monotime(void) 1628 { 1629 struct timespec ts; 1630 1631 monotime_ts(&ts); 1632 return (ts.tv_sec); 1633 } 1634 1635 double 1636 monotime_double(void) 1637 { 1638 struct timespec ts; 1639 1640 monotime_ts(&ts); 1641 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1642 } 1643 1644 void 1645 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1646 { 1647 bw->buflen = buflen; 1648 bw->rate = kbps; 1649 bw->thresh = buflen; 1650 bw->lamt = 0; 1651 timerclear(&bw->bwstart); 1652 timerclear(&bw->bwend); 1653 } 1654 1655 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1656 void 1657 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1658 { 1659 u_int64_t waitlen; 1660 struct timespec ts, rm; 1661 1662 bw->lamt += read_len; 1663 if (!timerisset(&bw->bwstart)) { 1664 monotime_tv(&bw->bwstart); 1665 return; 1666 } 1667 if (bw->lamt < bw->thresh) 1668 return; 1669 1670 monotime_tv(&bw->bwend); 1671 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1672 if (!timerisset(&bw->bwend)) 1673 return; 1674 1675 bw->lamt *= 8; 1676 waitlen = (double)1000000L * bw->lamt / bw->rate; 1677 1678 bw->bwstart.tv_sec = waitlen / 1000000L; 1679 bw->bwstart.tv_usec = waitlen % 1000000L; 1680 1681 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1682 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1683 1684 /* Adjust the wait time */ 1685 if (bw->bwend.tv_sec) { 1686 bw->thresh /= 2; 1687 if (bw->thresh < bw->buflen / 4) 1688 bw->thresh = bw->buflen / 4; 1689 } else if (bw->bwend.tv_usec < 10000) { 1690 bw->thresh *= 2; 1691 if (bw->thresh > bw->buflen * 8) 1692 bw->thresh = bw->buflen * 8; 1693 } 1694 1695 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1696 while (nanosleep(&ts, &rm) == -1) { 1697 if (errno != EINTR) 1698 break; 1699 ts = rm; 1700 } 1701 } 1702 1703 bw->lamt = 0; 1704 monotime_tv(&bw->bwstart); 1705 } 1706 1707 /* Make a template filename for mk[sd]temp() */ 1708 void 1709 mktemp_proto(char *s, size_t len) 1710 { 1711 const char *tmpdir; 1712 int r; 1713 1714 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1715 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1716 if (r > 0 && (size_t)r < len) 1717 return; 1718 } 1719 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1720 if (r < 0 || (size_t)r >= len) 1721 fatal_f("template string too short"); 1722 } 1723 1724 static const struct { 1725 const char *name; 1726 int value; 1727 } ipqos[] = { 1728 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1729 { "af11", IPTOS_DSCP_AF11 }, 1730 { "af12", IPTOS_DSCP_AF12 }, 1731 { "af13", IPTOS_DSCP_AF13 }, 1732 { "af21", IPTOS_DSCP_AF21 }, 1733 { "af22", IPTOS_DSCP_AF22 }, 1734 { "af23", IPTOS_DSCP_AF23 }, 1735 { "af31", IPTOS_DSCP_AF31 }, 1736 { "af32", IPTOS_DSCP_AF32 }, 1737 { "af33", IPTOS_DSCP_AF33 }, 1738 { "af41", IPTOS_DSCP_AF41 }, 1739 { "af42", IPTOS_DSCP_AF42 }, 1740 { "af43", IPTOS_DSCP_AF43 }, 1741 { "cs0", IPTOS_DSCP_CS0 }, 1742 { "cs1", IPTOS_DSCP_CS1 }, 1743 { "cs2", IPTOS_DSCP_CS2 }, 1744 { "cs3", IPTOS_DSCP_CS3 }, 1745 { "cs4", IPTOS_DSCP_CS4 }, 1746 { "cs5", IPTOS_DSCP_CS5 }, 1747 { "cs6", IPTOS_DSCP_CS6 }, 1748 { "cs7", IPTOS_DSCP_CS7 }, 1749 { "ef", IPTOS_DSCP_EF }, 1750 { "le", IPTOS_DSCP_LE }, 1751 { "lowdelay", IPTOS_LOWDELAY }, 1752 { "throughput", IPTOS_THROUGHPUT }, 1753 { "reliability", IPTOS_RELIABILITY }, 1754 { NULL, -1 } 1755 }; 1756 1757 int 1758 parse_ipqos(const char *cp) 1759 { 1760 u_int i; 1761 char *ep; 1762 long val; 1763 1764 if (cp == NULL) 1765 return -1; 1766 for (i = 0; ipqos[i].name != NULL; i++) { 1767 if (strcasecmp(cp, ipqos[i].name) == 0) 1768 return ipqos[i].value; 1769 } 1770 /* Try parsing as an integer */ 1771 val = strtol(cp, &ep, 0); 1772 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1773 return -1; 1774 return val; 1775 } 1776 1777 const char * 1778 iptos2str(int iptos) 1779 { 1780 int i; 1781 static char iptos_str[sizeof "0xff"]; 1782 1783 for (i = 0; ipqos[i].name != NULL; i++) { 1784 if (ipqos[i].value == iptos) 1785 return ipqos[i].name; 1786 } 1787 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1788 return iptos_str; 1789 } 1790 1791 void 1792 lowercase(char *s) 1793 { 1794 for (; *s; s++) 1795 *s = tolower((u_char)*s); 1796 } 1797 1798 int 1799 unix_listener(const char *path, int backlog, int unlink_first) 1800 { 1801 struct sockaddr_un sunaddr; 1802 int saved_errno, sock; 1803 1804 memset(&sunaddr, 0, sizeof(sunaddr)); 1805 sunaddr.sun_family = AF_UNIX; 1806 if (strlcpy(sunaddr.sun_path, path, 1807 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1808 error_f("path \"%s\" too long for Unix domain socket", path); 1809 errno = ENAMETOOLONG; 1810 return -1; 1811 } 1812 1813 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1814 if (sock == -1) { 1815 saved_errno = errno; 1816 error_f("socket: %.100s", strerror(errno)); 1817 errno = saved_errno; 1818 return -1; 1819 } 1820 if (unlink_first == 1) { 1821 if (unlink(path) != 0 && errno != ENOENT) 1822 error("unlink(%s): %.100s", path, strerror(errno)); 1823 } 1824 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1825 saved_errno = errno; 1826 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1827 close(sock); 1828 errno = saved_errno; 1829 return -1; 1830 } 1831 if (listen(sock, backlog) == -1) { 1832 saved_errno = errno; 1833 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1834 close(sock); 1835 unlink(path); 1836 errno = saved_errno; 1837 return -1; 1838 } 1839 return sock; 1840 } 1841 1842 /* 1843 * Compares two strings that maybe be NULL. Returns non-zero if strings 1844 * are both NULL or are identical, returns zero otherwise. 1845 */ 1846 static int 1847 strcmp_maybe_null(const char *a, const char *b) 1848 { 1849 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1850 return 0; 1851 if (a != NULL && strcmp(a, b) != 0) 1852 return 0; 1853 return 1; 1854 } 1855 1856 /* 1857 * Compare two forwards, returning non-zero if they are identical or 1858 * zero otherwise. 1859 */ 1860 int 1861 forward_equals(const struct Forward *a, const struct Forward *b) 1862 { 1863 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1864 return 0; 1865 if (a->listen_port != b->listen_port) 1866 return 0; 1867 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1868 return 0; 1869 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1870 return 0; 1871 if (a->connect_port != b->connect_port) 1872 return 0; 1873 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1874 return 0; 1875 /* allocated_port and handle are not checked */ 1876 return 1; 1877 } 1878 1879 /* returns 1 if process is already daemonized, 0 otherwise */ 1880 int 1881 daemonized(void) 1882 { 1883 int fd; 1884 1885 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1886 close(fd); 1887 return 0; /* have controlling terminal */ 1888 } 1889 if (getppid() != 1) 1890 return 0; /* parent is not init */ 1891 if (getsid(0) != getpid()) 1892 return 0; /* not session leader */ 1893 debug3("already daemonized"); 1894 return 1; 1895 } 1896 1897 /* 1898 * Splits 's' into an argument vector. Handles quoted string and basic 1899 * escape characters (\\, \", \'). Caller must free the argument vector 1900 * and its members. 1901 */ 1902 int 1903 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1904 { 1905 int r = SSH_ERR_INTERNAL_ERROR; 1906 int argc = 0, quote, i, j; 1907 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1908 1909 *argvp = NULL; 1910 *argcp = 0; 1911 1912 for (i = 0; s[i] != '\0'; i++) { 1913 /* Skip leading whitespace */ 1914 if (s[i] == ' ' || s[i] == '\t') 1915 continue; 1916 if (terminate_on_comment && s[i] == '#') 1917 break; 1918 /* Start of a token */ 1919 quote = 0; 1920 1921 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1922 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1923 argv[argc] = NULL; 1924 1925 /* Copy the token in, removing escapes */ 1926 for (j = 0; s[i] != '\0'; i++) { 1927 if (s[i] == '\\') { 1928 if (s[i + 1] == '\'' || 1929 s[i + 1] == '\"' || 1930 s[i + 1] == '\\' || 1931 (quote == 0 && s[i + 1] == ' ')) { 1932 i++; /* Skip '\' */ 1933 arg[j++] = s[i]; 1934 } else { 1935 /* Unrecognised escape */ 1936 arg[j++] = s[i]; 1937 } 1938 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1939 break; /* done */ 1940 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1941 quote = s[i]; /* quote start */ 1942 else if (quote != 0 && s[i] == quote) 1943 quote = 0; /* quote end */ 1944 else 1945 arg[j++] = s[i]; 1946 } 1947 if (s[i] == '\0') { 1948 if (quote != 0) { 1949 /* Ran out of string looking for close quote */ 1950 r = SSH_ERR_INVALID_FORMAT; 1951 goto out; 1952 } 1953 break; 1954 } 1955 } 1956 /* Success */ 1957 *argcp = argc; 1958 *argvp = argv; 1959 argc = 0; 1960 argv = NULL; 1961 r = 0; 1962 out: 1963 if (argc != 0 && argv != NULL) { 1964 for (i = 0; i < argc; i++) 1965 free(argv[i]); 1966 free(argv); 1967 } 1968 return r; 1969 } 1970 1971 /* 1972 * Reassemble an argument vector into a string, quoting and escaping as 1973 * necessary. Caller must free returned string. 1974 */ 1975 char * 1976 argv_assemble(int argc, char **argv) 1977 { 1978 int i, j, ws, r; 1979 char c, *ret; 1980 struct sshbuf *buf, *arg; 1981 1982 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1983 fatal_f("sshbuf_new failed"); 1984 1985 for (i = 0; i < argc; i++) { 1986 ws = 0; 1987 sshbuf_reset(arg); 1988 for (j = 0; argv[i][j] != '\0'; j++) { 1989 r = 0; 1990 c = argv[i][j]; 1991 switch (c) { 1992 case ' ': 1993 case '\t': 1994 ws = 1; 1995 r = sshbuf_put_u8(arg, c); 1996 break; 1997 case '\\': 1998 case '\'': 1999 case '"': 2000 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2001 break; 2002 /* FALLTHROUGH */ 2003 default: 2004 r = sshbuf_put_u8(arg, c); 2005 break; 2006 } 2007 if (r != 0) 2008 fatal_fr(r, "sshbuf_put_u8"); 2009 } 2010 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2011 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2012 (r = sshbuf_putb(buf, arg)) != 0 || 2013 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2014 fatal_fr(r, "assemble"); 2015 } 2016 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2017 fatal_f("malloc failed"); 2018 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2019 ret[sshbuf_len(buf)] = '\0'; 2020 sshbuf_free(buf); 2021 sshbuf_free(arg); 2022 return ret; 2023 } 2024 2025 char * 2026 argv_next(int *argcp, char ***argvp) 2027 { 2028 char *ret = (*argvp)[0]; 2029 2030 if (*argcp > 0 && ret != NULL) { 2031 (*argcp)--; 2032 (*argvp)++; 2033 } 2034 return ret; 2035 } 2036 2037 void 2038 argv_consume(int *argcp) 2039 { 2040 *argcp = 0; 2041 } 2042 2043 void 2044 argv_free(char **av, int ac) 2045 { 2046 int i; 2047 2048 if (av == NULL) 2049 return; 2050 for (i = 0; i < ac; i++) 2051 free(av[i]); 2052 free(av); 2053 } 2054 2055 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2056 int 2057 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2058 { 2059 int status; 2060 2061 while (waitpid(pid, &status, 0) == -1) { 2062 if (errno != EINTR) { 2063 error("%s waitpid: %s", tag, strerror(errno)); 2064 return -1; 2065 } 2066 } 2067 if (WIFSIGNALED(status)) { 2068 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2069 return -1; 2070 } else if (WEXITSTATUS(status) != 0) { 2071 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2072 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2073 return -1; 2074 } 2075 return 0; 2076 } 2077 2078 /* 2079 * Check a given path for security. This is defined as all components 2080 * of the path to the file must be owned by either the owner of 2081 * of the file or root and no directories must be group or world writable. 2082 * 2083 * XXX Should any specific check be done for sym links ? 2084 * 2085 * Takes a file name, its stat information (preferably from fstat() to 2086 * avoid races), the uid of the expected owner, their home directory and an 2087 * error buffer plus max size as arguments. 2088 * 2089 * Returns 0 on success and -1 on failure 2090 */ 2091 int 2092 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2093 uid_t uid, char *err, size_t errlen) 2094 { 2095 char buf[PATH_MAX], homedir[PATH_MAX]; 2096 char *cp; 2097 int comparehome = 0; 2098 struct stat st; 2099 2100 if (realpath(name, buf) == NULL) { 2101 snprintf(err, errlen, "realpath %s failed: %s", name, 2102 strerror(errno)); 2103 return -1; 2104 } 2105 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2106 comparehome = 1; 2107 2108 if (!S_ISREG(stp->st_mode)) { 2109 snprintf(err, errlen, "%s is not a regular file", buf); 2110 return -1; 2111 } 2112 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2113 (stp->st_mode & 022) != 0) { 2114 snprintf(err, errlen, "bad ownership or modes for file %s", 2115 buf); 2116 return -1; 2117 } 2118 2119 /* for each component of the canonical path, walking upwards */ 2120 for (;;) { 2121 if ((cp = dirname(buf)) == NULL) { 2122 snprintf(err, errlen, "dirname() failed"); 2123 return -1; 2124 } 2125 strlcpy(buf, cp, sizeof(buf)); 2126 2127 if (stat(buf, &st) == -1 || 2128 (st.st_uid != 0 && st.st_uid != uid) || 2129 (st.st_mode & 022) != 0) { 2130 snprintf(err, errlen, 2131 "bad ownership or modes for directory %s", buf); 2132 return -1; 2133 } 2134 2135 /* If are past the homedir then we can stop */ 2136 if (comparehome && strcmp(homedir, buf) == 0) 2137 break; 2138 2139 /* 2140 * dirname should always complete with a "/" path, 2141 * but we can be paranoid and check for "." too 2142 */ 2143 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2144 break; 2145 } 2146 return 0; 2147 } 2148 2149 /* 2150 * Version of safe_path() that accepts an open file descriptor to 2151 * avoid races. 2152 * 2153 * Returns 0 on success and -1 on failure 2154 */ 2155 int 2156 safe_path_fd(int fd, const char *file, struct passwd *pw, 2157 char *err, size_t errlen) 2158 { 2159 struct stat st; 2160 2161 /* check the open file to avoid races */ 2162 if (fstat(fd, &st) == -1) { 2163 snprintf(err, errlen, "cannot stat file %s: %s", 2164 file, strerror(errno)); 2165 return -1; 2166 } 2167 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2168 } 2169 2170 /* 2171 * Sets the value of the given variable in the environment. If the variable 2172 * already exists, its value is overridden. 2173 */ 2174 void 2175 child_set_env(char ***envp, u_int *envsizep, const char *name, 2176 const char *value) 2177 { 2178 char **env; 2179 u_int envsize; 2180 u_int i, namelen; 2181 2182 if (strchr(name, '=') != NULL) { 2183 error("Invalid environment variable \"%.100s\"", name); 2184 return; 2185 } 2186 2187 /* 2188 * Find the slot where the value should be stored. If the variable 2189 * already exists, we reuse the slot; otherwise we append a new slot 2190 * at the end of the array, expanding if necessary. 2191 */ 2192 env = *envp; 2193 namelen = strlen(name); 2194 for (i = 0; env[i]; i++) 2195 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2196 break; 2197 if (env[i]) { 2198 /* Reuse the slot. */ 2199 free(env[i]); 2200 } else { 2201 /* New variable. Expand if necessary. */ 2202 envsize = *envsizep; 2203 if (i >= envsize - 1) { 2204 if (envsize >= 1000) 2205 fatal("child_set_env: too many env vars"); 2206 envsize += 50; 2207 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2208 *envsizep = envsize; 2209 } 2210 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2211 env[i + 1] = NULL; 2212 } 2213 2214 /* Allocate space and format the variable in the appropriate slot. */ 2215 /* XXX xasprintf */ 2216 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2217 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2218 } 2219 2220 /* 2221 * Check and optionally lowercase a domain name, also removes trailing '.' 2222 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2223 */ 2224 int 2225 valid_domain(char *name, int makelower, const char **errstr) 2226 { 2227 size_t i, l = strlen(name); 2228 u_char c, last = '\0'; 2229 static char errbuf[256]; 2230 2231 if (l == 0) { 2232 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2233 goto bad; 2234 } 2235 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2236 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2237 "starts with invalid character", name); 2238 goto bad; 2239 } 2240 for (i = 0; i < l; i++) { 2241 c = tolower((u_char)name[i]); 2242 if (makelower) 2243 name[i] = (char)c; 2244 if (last == '.' && c == '.') { 2245 snprintf(errbuf, sizeof(errbuf), "domain name " 2246 "\"%.100s\" contains consecutive separators", name); 2247 goto bad; 2248 } 2249 if (c != '.' && c != '-' && !isalnum(c) && 2250 c != '_') /* technically invalid, but common */ { 2251 snprintf(errbuf, sizeof(errbuf), "domain name " 2252 "\"%.100s\" contains invalid characters", name); 2253 goto bad; 2254 } 2255 last = c; 2256 } 2257 if (name[l - 1] == '.') 2258 name[l - 1] = '\0'; 2259 if (errstr != NULL) 2260 *errstr = NULL; 2261 return 1; 2262 bad: 2263 if (errstr != NULL) 2264 *errstr = errbuf; 2265 return 0; 2266 } 2267 2268 /* 2269 * Verify that a environment variable name (not including initial '$') is 2270 * valid; consisting of one or more alphanumeric or underscore characters only. 2271 * Returns 1 on valid, 0 otherwise. 2272 */ 2273 int 2274 valid_env_name(const char *name) 2275 { 2276 const char *cp; 2277 2278 if (name[0] == '\0') 2279 return 0; 2280 for (cp = name; *cp != '\0'; cp++) { 2281 if (!isalnum((u_char)*cp) && *cp != '_') 2282 return 0; 2283 } 2284 return 1; 2285 } 2286 2287 const char * 2288 atoi_err(const char *nptr, int *val) 2289 { 2290 const char *errstr = NULL; 2291 long long num; 2292 2293 if (nptr == NULL || *nptr == '\0') 2294 return "missing"; 2295 num = strtonum(nptr, 0, INT_MAX, &errstr); 2296 if (errstr == NULL) 2297 *val = (int)num; 2298 return errstr; 2299 } 2300 2301 int 2302 parse_absolute_time(const char *s, uint64_t *tp) 2303 { 2304 struct tm tm; 2305 time_t tt; 2306 char buf[32], *fmt; 2307 const char *cp; 2308 size_t l; 2309 int is_utc = 0; 2310 2311 *tp = 0; 2312 2313 l = strlen(s); 2314 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) { 2315 is_utc = 1; 2316 l--; 2317 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) { 2318 is_utc = 1; 2319 l -= 3; 2320 } 2321 /* 2322 * POSIX strptime says "The application shall ensure that there 2323 * is white-space or other non-alphanumeric characters between 2324 * any two conversion specifications" so arrange things this way. 2325 */ 2326 switch (l) { 2327 case 8: /* YYYYMMDD */ 2328 fmt = "%Y-%m-%d"; 2329 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2330 break; 2331 case 12: /* YYYYMMDDHHMM */ 2332 fmt = "%Y-%m-%dT%H:%M"; 2333 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2334 s, s + 4, s + 6, s + 8, s + 10); 2335 break; 2336 case 14: /* YYYYMMDDHHMMSS */ 2337 fmt = "%Y-%m-%dT%H:%M:%S"; 2338 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2339 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2340 break; 2341 default: 2342 return SSH_ERR_INVALID_FORMAT; 2343 } 2344 2345 memset(&tm, 0, sizeof(tm)); 2346 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0') 2347 return SSH_ERR_INVALID_FORMAT; 2348 if (is_utc) { 2349 if ((tt = timegm(&tm)) < 0) 2350 return SSH_ERR_INVALID_FORMAT; 2351 } else { 2352 if ((tt = mktime(&tm)) < 0) 2353 return SSH_ERR_INVALID_FORMAT; 2354 } 2355 /* success */ 2356 *tp = (uint64_t)tt; 2357 return 0; 2358 } 2359 2360 void 2361 format_absolute_time(uint64_t t, char *buf, size_t len) 2362 { 2363 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2364 struct tm tm; 2365 2366 localtime_r(&tt, &tm); 2367 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2368 } 2369 2370 /* check if path is absolute */ 2371 int 2372 path_absolute(const char *path) 2373 { 2374 return (*path == '/') ? 1 : 0; 2375 } 2376 2377 void 2378 skip_space(char **cpp) 2379 { 2380 char *cp; 2381 2382 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2383 ; 2384 *cpp = cp; 2385 } 2386 2387 /* authorized_key-style options parsing helpers */ 2388 2389 /* 2390 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2391 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2392 * if negated option matches. 2393 * If the option or negated option matches, then *optsp is updated to 2394 * point to the first character after the option. 2395 */ 2396 int 2397 opt_flag(const char *opt, int allow_negate, const char **optsp) 2398 { 2399 size_t opt_len = strlen(opt); 2400 const char *opts = *optsp; 2401 int negate = 0; 2402 2403 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2404 opts += 3; 2405 negate = 1; 2406 } 2407 if (strncasecmp(opts, opt, opt_len) == 0) { 2408 *optsp = opts + opt_len; 2409 return negate ? 0 : 1; 2410 } 2411 return -1; 2412 } 2413 2414 char * 2415 opt_dequote(const char **sp, const char **errstrp) 2416 { 2417 const char *s = *sp; 2418 char *ret; 2419 size_t i; 2420 2421 *errstrp = NULL; 2422 if (*s != '"') { 2423 *errstrp = "missing start quote"; 2424 return NULL; 2425 } 2426 s++; 2427 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2428 *errstrp = "memory allocation failed"; 2429 return NULL; 2430 } 2431 for (i = 0; *s != '\0' && *s != '"';) { 2432 if (s[0] == '\\' && s[1] == '"') 2433 s++; 2434 ret[i++] = *s++; 2435 } 2436 if (*s == '\0') { 2437 *errstrp = "missing end quote"; 2438 free(ret); 2439 return NULL; 2440 } 2441 ret[i] = '\0'; 2442 s++; 2443 *sp = s; 2444 return ret; 2445 } 2446 2447 int 2448 opt_match(const char **opts, const char *term) 2449 { 2450 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2451 (*opts)[strlen(term)] == '=') { 2452 *opts += strlen(term) + 1; 2453 return 1; 2454 } 2455 return 0; 2456 } 2457 2458 void 2459 opt_array_append2(const char *file, const int line, const char *directive, 2460 char ***array, int **iarray, u_int *lp, const char *s, int i) 2461 { 2462 2463 if (*lp >= INT_MAX) 2464 fatal("%s line %d: Too many %s entries", file, line, directive); 2465 2466 if (iarray != NULL) { 2467 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2468 sizeof(**iarray)); 2469 (*iarray)[*lp] = i; 2470 } 2471 2472 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2473 (*array)[*lp] = xstrdup(s); 2474 (*lp)++; 2475 } 2476 2477 void 2478 opt_array_append(const char *file, const int line, const char *directive, 2479 char ***array, u_int *lp, const char *s) 2480 { 2481 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2482 } 2483 2484 sshsig_t 2485 ssh_signal(int signum, sshsig_t handler) 2486 { 2487 struct sigaction sa, osa; 2488 2489 /* mask all other signals while in handler */ 2490 memset(&sa, 0, sizeof(sa)); 2491 sa.sa_handler = handler; 2492 sigfillset(&sa.sa_mask); 2493 if (signum != SIGALRM) 2494 sa.sa_flags = SA_RESTART; 2495 if (sigaction(signum, &sa, &osa) == -1) { 2496 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2497 return SIG_ERR; 2498 } 2499 return osa.sa_handler; 2500 } 2501 2502 int 2503 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2504 { 2505 int devnull, ret = 0; 2506 2507 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2508 error_f("open %s: %s", _PATH_DEVNULL, 2509 strerror(errno)); 2510 return -1; 2511 } 2512 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2513 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2514 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2515 error_f("dup2: %s", strerror(errno)); 2516 ret = -1; 2517 } 2518 if (devnull > STDERR_FILENO) 2519 close(devnull); 2520 return ret; 2521 } 2522 2523 /* 2524 * Runs command in a subprocess with a minimal environment. 2525 * Returns pid on success, 0 on failure. 2526 * The child stdout and stderr maybe captured, left attached or sent to 2527 * /dev/null depending on the contents of flags. 2528 * "tag" is prepended to log messages. 2529 * NB. "command" is only used for logging; the actual command executed is 2530 * av[0]. 2531 */ 2532 pid_t 2533 subprocess(const char *tag, const char *command, 2534 int ac, char **av, FILE **child, u_int flags, 2535 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2536 { 2537 FILE *f = NULL; 2538 struct stat st; 2539 int fd, devnull, p[2], i; 2540 pid_t pid; 2541 char *cp, errmsg[512]; 2542 u_int nenv = 0; 2543 char **env = NULL; 2544 2545 /* If dropping privs, then must specify user and restore function */ 2546 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2547 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2548 return 0; 2549 } 2550 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2551 error("%s: no user for current uid", tag); 2552 return 0; 2553 } 2554 if (child != NULL) 2555 *child = NULL; 2556 2557 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2558 tag, command, pw->pw_name, flags); 2559 2560 /* Check consistency */ 2561 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2562 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2563 error_f("inconsistent flags"); 2564 return 0; 2565 } 2566 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2567 error_f("inconsistent flags/output"); 2568 return 0; 2569 } 2570 2571 /* 2572 * If executing an explicit binary, then verify the it exists 2573 * and appears safe-ish to execute 2574 */ 2575 if (!path_absolute(av[0])) { 2576 error("%s path is not absolute", tag); 2577 return 0; 2578 } 2579 if (drop_privs != NULL) 2580 drop_privs(pw); 2581 if (stat(av[0], &st) == -1) { 2582 error("Could not stat %s \"%s\": %s", tag, 2583 av[0], strerror(errno)); 2584 goto restore_return; 2585 } 2586 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2587 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2588 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2589 goto restore_return; 2590 } 2591 /* Prepare to keep the child's stdout if requested */ 2592 if (pipe(p) == -1) { 2593 error("%s: pipe: %s", tag, strerror(errno)); 2594 restore_return: 2595 if (restore_privs != NULL) 2596 restore_privs(); 2597 return 0; 2598 } 2599 if (restore_privs != NULL) 2600 restore_privs(); 2601 2602 switch ((pid = fork())) { 2603 case -1: /* error */ 2604 error("%s: fork: %s", tag, strerror(errno)); 2605 close(p[0]); 2606 close(p[1]); 2607 return 0; 2608 case 0: /* child */ 2609 /* Prepare a minimal environment for the child. */ 2610 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2611 nenv = 5; 2612 env = xcalloc(sizeof(*env), nenv); 2613 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2614 child_set_env(&env, &nenv, "USER", pw->pw_name); 2615 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2616 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2617 if ((cp = getenv("LANG")) != NULL) 2618 child_set_env(&env, &nenv, "LANG", cp); 2619 } 2620 2621 for (i = 1; i < NSIG; i++) 2622 ssh_signal(i, SIG_DFL); 2623 2624 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2625 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2626 strerror(errno)); 2627 _exit(1); 2628 } 2629 if (dup2(devnull, STDIN_FILENO) == -1) { 2630 error("%s: dup2: %s", tag, strerror(errno)); 2631 _exit(1); 2632 } 2633 2634 /* Set up stdout as requested; leave stderr in place for now. */ 2635 fd = -1; 2636 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2637 fd = p[1]; 2638 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2639 fd = devnull; 2640 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2641 error("%s: dup2: %s", tag, strerror(errno)); 2642 _exit(1); 2643 } 2644 closefrom(STDERR_FILENO + 1); 2645 2646 if (geteuid() == 0 && 2647 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2648 error("%s: initgroups(%s, %u): %s", tag, 2649 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2650 _exit(1); 2651 } 2652 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2653 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2654 strerror(errno)); 2655 _exit(1); 2656 } 2657 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2658 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2659 strerror(errno)); 2660 _exit(1); 2661 } 2662 /* stdin is pointed to /dev/null at this point */ 2663 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2664 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2665 error("%s: dup2: %s", tag, strerror(errno)); 2666 _exit(1); 2667 } 2668 if (env != NULL) 2669 execve(av[0], av, env); 2670 else 2671 execv(av[0], av); 2672 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2673 command, strerror(errno)); 2674 _exit(127); 2675 default: /* parent */ 2676 break; 2677 } 2678 2679 close(p[1]); 2680 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2681 close(p[0]); 2682 else if ((f = fdopen(p[0], "r")) == NULL) { 2683 error("%s: fdopen: %s", tag, strerror(errno)); 2684 close(p[0]); 2685 /* Don't leave zombie child */ 2686 kill(pid, SIGTERM); 2687 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2688 ; 2689 return 0; 2690 } 2691 /* Success */ 2692 debug3_f("%s pid %ld", tag, (long)pid); 2693 if (child != NULL) 2694 *child = f; 2695 return pid; 2696 } 2697 2698 const char * 2699 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2700 { 2701 size_t i, envlen; 2702 2703 envlen = strlen(env); 2704 for (i = 0; i < nenvs; i++) { 2705 if (strncmp(envs[i], env, envlen) == 0 && 2706 envs[i][envlen] == '=') { 2707 return envs[i] + envlen + 1; 2708 } 2709 } 2710 return NULL; 2711 } 2712 2713 const char * 2714 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs) 2715 { 2716 char *name, *cp; 2717 const char *ret; 2718 2719 name = xstrdup(env); 2720 if ((cp = strchr(name, '=')) == NULL) { 2721 free(name); 2722 return NULL; /* not env=val */ 2723 } 2724 *cp = '\0'; 2725 ret = lookup_env_in_list(name, envs, nenvs); 2726 free(name); 2727 return ret; 2728 } 2729 2730 /* 2731 * Helpers for managing poll(2)/ppoll(2) timeouts 2732 * Will remember the earliest deadline and return it for use in poll/ppoll. 2733 */ 2734 2735 /* Initialise a poll/ppoll timeout with an indefinite deadline */ 2736 void 2737 ptimeout_init(struct timespec *pt) 2738 { 2739 /* 2740 * Deliberately invalid for ppoll(2). 2741 * Will be converted to NULL in ptimeout_get_tspec() later. 2742 */ 2743 pt->tv_sec = -1; 2744 pt->tv_nsec = 0; 2745 } 2746 2747 /* Specify a poll/ppoll deadline of at most 'sec' seconds */ 2748 void 2749 ptimeout_deadline_sec(struct timespec *pt, long sec) 2750 { 2751 if (pt->tv_sec == -1 || pt->tv_sec >= sec) { 2752 pt->tv_sec = sec; 2753 pt->tv_nsec = 0; 2754 } 2755 } 2756 2757 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */ 2758 static void 2759 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p) 2760 { 2761 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=)) 2762 *pt = *p; 2763 } 2764 2765 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */ 2766 void 2767 ptimeout_deadline_ms(struct timespec *pt, long ms) 2768 { 2769 struct timespec p; 2770 2771 p.tv_sec = ms / 1000; 2772 p.tv_nsec = (ms % 1000) * 1000000; 2773 ptimeout_deadline_tsp(pt, &p); 2774 } 2775 2776 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */ 2777 void 2778 ptimeout_deadline_monotime(struct timespec *pt, time_t when) 2779 { 2780 struct timespec now, t; 2781 2782 t.tv_sec = when; 2783 t.tv_nsec = 0; 2784 monotime_ts(&now); 2785 2786 if (timespeccmp(&now, &t, >=)) 2787 ptimeout_deadline_sec(pt, 0); 2788 else { 2789 timespecsub(&t, &now, &t); 2790 ptimeout_deadline_tsp(pt, &t); 2791 } 2792 } 2793 2794 /* Get a poll(2) timeout value in milliseconds */ 2795 int 2796 ptimeout_get_ms(struct timespec *pt) 2797 { 2798 if (pt->tv_sec == -1) 2799 return -1; 2800 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000) 2801 return INT_MAX; 2802 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000); 2803 } 2804 2805 /* Get a ppoll(2) timeout value as a timespec pointer */ 2806 struct timespec * 2807 ptimeout_get_tsp(struct timespec *pt) 2808 { 2809 return pt->tv_sec == -1 ? NULL : pt; 2810 } 2811 2812 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */ 2813 int 2814 ptimeout_isset(struct timespec *pt) 2815 { 2816 return pt->tv_sec != -1; 2817 } 2818 2819 /* 2820 * Returns zero if the library at 'path' contains symbol 's', nonzero 2821 * otherwise. 2822 */ 2823 int 2824 lib_contains_symbol(const char *path, const char *s) 2825 { 2826 struct nlist nl[2]; 2827 int ret = -1, r; 2828 2829 memset(nl, 0, sizeof(nl)); 2830 nl[0].n_name = xstrdup(s); 2831 nl[1].n_name = NULL; 2832 if ((r = nlist(path, nl)) == -1) { 2833 error_f("nlist failed for %s", path); 2834 goto out; 2835 } 2836 if (r != 0 || nl[0].n_value == 0 || nl[0].n_type == 0) { 2837 error_f("library %s does not contain symbol %s", path, s); 2838 goto out; 2839 } 2840 /* success */ 2841 ret = 0; 2842 out: 2843 free(nl[0].n_name); 2844 return ret; 2845 } 2846