1 /* $OpenBSD: misc.c,v 1.172 2022/01/08 07:32:45 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 <poll.h> 44 #include <signal.h> 45 #include <stdarg.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 51 #include "xmalloc.h" 52 #include "misc.h" 53 #include "log.h" 54 #include "ssh.h" 55 #include "sshbuf.h" 56 #include "ssherr.h" 57 58 /* remove newline at end of string */ 59 char * 60 chop(char *s) 61 { 62 char *t = s; 63 while (*t) { 64 if (*t == '\n' || *t == '\r') { 65 *t = '\0'; 66 return s; 67 } 68 t++; 69 } 70 return s; 71 72 } 73 74 /* remove whitespace from end of string */ 75 void 76 rtrim(char *s) 77 { 78 size_t i; 79 80 if ((i = strlen(s)) == 0) 81 return; 82 for (i--; i > 0; i--) { 83 if (isspace((int)s[i])) 84 s[i] = '\0'; 85 } 86 } 87 88 /* set/unset filedescriptor to non-blocking */ 89 int 90 set_nonblock(int fd) 91 { 92 int val; 93 94 val = fcntl(fd, F_GETFL); 95 if (val == -1) { 96 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 97 return (-1); 98 } 99 if (val & O_NONBLOCK) { 100 debug3("fd %d is O_NONBLOCK", fd); 101 return (0); 102 } 103 debug2("fd %d setting O_NONBLOCK", fd); 104 val |= O_NONBLOCK; 105 if (fcntl(fd, F_SETFL, val) == -1) { 106 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 107 strerror(errno)); 108 return (-1); 109 } 110 return (0); 111 } 112 113 int 114 unset_nonblock(int fd) 115 { 116 int val; 117 118 val = fcntl(fd, F_GETFL); 119 if (val == -1) { 120 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 121 return (-1); 122 } 123 if (!(val & O_NONBLOCK)) { 124 debug3("fd %d is not O_NONBLOCK", fd); 125 return (0); 126 } 127 debug("fd %d clearing O_NONBLOCK", fd); 128 val &= ~O_NONBLOCK; 129 if (fcntl(fd, F_SETFL, val) == -1) { 130 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 131 fd, strerror(errno)); 132 return (-1); 133 } 134 return (0); 135 } 136 137 const char * 138 ssh_gai_strerror(int gaierr) 139 { 140 if (gaierr == EAI_SYSTEM && errno != 0) 141 return strerror(errno); 142 return gai_strerror(gaierr); 143 } 144 145 /* disable nagle on socket */ 146 void 147 set_nodelay(int fd) 148 { 149 int opt; 150 socklen_t optlen; 151 152 optlen = sizeof opt; 153 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 154 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 155 return; 156 } 157 if (opt == 1) { 158 debug2("fd %d is TCP_NODELAY", fd); 159 return; 160 } 161 opt = 1; 162 debug2("fd %d setting TCP_NODELAY", fd); 163 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 164 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 165 } 166 167 /* Allow local port reuse in TIME_WAIT */ 168 int 169 set_reuseaddr(int fd) 170 { 171 int on = 1; 172 173 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 174 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 175 return -1; 176 } 177 return 0; 178 } 179 180 /* Get/set routing domain */ 181 char * 182 get_rdomain(int fd) 183 { 184 int rtable; 185 char *ret; 186 socklen_t len = sizeof(rtable); 187 188 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 189 error("Failed to get routing domain for fd %d: %s", 190 fd, strerror(errno)); 191 return NULL; 192 } 193 xasprintf(&ret, "%d", rtable); 194 return ret; 195 } 196 197 int 198 set_rdomain(int fd, const char *name) 199 { 200 int rtable; 201 const char *errstr; 202 203 if (name == NULL) 204 return 0; /* default table */ 205 206 rtable = (int)strtonum(name, 0, 255, &errstr); 207 if (errstr != NULL) { 208 /* Shouldn't happen */ 209 error("Invalid routing domain \"%s\": %s", name, errstr); 210 return -1; 211 } 212 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 213 &rtable, sizeof(rtable)) == -1) { 214 error("Failed to set routing domain %d on fd %d: %s", 215 rtable, fd, strerror(errno)); 216 return -1; 217 } 218 return 0; 219 } 220 221 int 222 get_sock_af(int fd) 223 { 224 struct sockaddr_storage to; 225 socklen_t tolen = sizeof(to); 226 227 memset(&to, 0, sizeof(to)); 228 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 229 return -1; 230 return to.ss_family; 231 } 232 233 void 234 set_sock_tos(int fd, int tos) 235 { 236 int af; 237 238 switch ((af = get_sock_af(fd))) { 239 case -1: 240 /* assume not a socket */ 241 break; 242 case AF_INET: 243 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 244 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 245 &tos, sizeof(tos)) == -1) { 246 error("setsockopt socket %d IP_TOS %d: %s:", 247 fd, tos, strerror(errno)); 248 } 249 break; 250 case AF_INET6: 251 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 252 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 253 &tos, sizeof(tos)) == -1) { 254 error("setsockopt socket %d IPV6_TCLASS %d: %.100s:", 255 fd, tos, strerror(errno)); 256 } 257 break; 258 default: 259 debug2_f("unsupported socket family %d", af); 260 break; 261 } 262 } 263 264 /* 265 * Wait up to *timeoutp milliseconds for events on fd. Updates 266 * *timeoutp with time remaining. 267 * Returns 0 if fd ready or -1 on timeout or error (see errno). 268 */ 269 static int 270 waitfd(int fd, int *timeoutp, short events) 271 { 272 struct pollfd pfd; 273 struct timeval t_start; 274 int oerrno, r; 275 276 pfd.fd = fd; 277 pfd.events = events; 278 for (; *timeoutp >= 0;) { 279 monotime_tv(&t_start); 280 r = poll(&pfd, 1, *timeoutp); 281 oerrno = errno; 282 ms_subtract_diff(&t_start, timeoutp); 283 errno = oerrno; 284 if (r > 0) 285 return 0; 286 else if (r == -1 && errno != EAGAIN && errno != EINTR) 287 return -1; 288 else if (r == 0) 289 break; 290 } 291 /* timeout */ 292 errno = ETIMEDOUT; 293 return -1; 294 } 295 296 /* 297 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 298 * *timeoutp with time remaining. 299 * Returns 0 if fd ready or -1 on timeout or error (see errno). 300 */ 301 int 302 waitrfd(int fd, int *timeoutp) { 303 return waitfd(fd, timeoutp, POLLIN); 304 } 305 306 /* 307 * Attempt a non-blocking connect(2) to the specified address, waiting up to 308 * *timeoutp milliseconds for the connection to complete. If the timeout is 309 * <=0, then wait indefinitely. 310 * 311 * Returns 0 on success or -1 on failure. 312 */ 313 int 314 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 315 socklen_t addrlen, int *timeoutp) 316 { 317 int optval = 0; 318 socklen_t optlen = sizeof(optval); 319 320 /* No timeout: just do a blocking connect() */ 321 if (timeoutp == NULL || *timeoutp <= 0) 322 return connect(sockfd, serv_addr, addrlen); 323 324 set_nonblock(sockfd); 325 for (;;) { 326 if (connect(sockfd, serv_addr, addrlen) == 0) { 327 /* Succeeded already? */ 328 unset_nonblock(sockfd); 329 return 0; 330 } else if (errno == EINTR) 331 continue; 332 else if (errno != EINPROGRESS) 333 return -1; 334 break; 335 } 336 337 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) 338 return -1; 339 340 /* Completed or failed */ 341 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 342 debug("getsockopt: %s", strerror(errno)); 343 return -1; 344 } 345 if (optval != 0) { 346 errno = optval; 347 return -1; 348 } 349 unset_nonblock(sockfd); 350 return 0; 351 } 352 353 /* Characters considered whitespace in strsep calls. */ 354 #define WHITESPACE " \t\r\n" 355 #define QUOTE "\"" 356 357 /* return next token in configuration line */ 358 static char * 359 strdelim_internal(char **s, int split_equals) 360 { 361 char *old; 362 int wspace = 0; 363 364 if (*s == NULL) 365 return NULL; 366 367 old = *s; 368 369 *s = strpbrk(*s, 370 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 371 if (*s == NULL) 372 return (old); 373 374 if (*s[0] == '\"') { 375 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 376 /* Find matching quote */ 377 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 378 return (NULL); /* no matching quote */ 379 } else { 380 *s[0] = '\0'; 381 *s += strspn(*s + 1, WHITESPACE) + 1; 382 return (old); 383 } 384 } 385 386 /* Allow only one '=' to be skipped */ 387 if (split_equals && *s[0] == '=') 388 wspace = 1; 389 *s[0] = '\0'; 390 391 /* Skip any extra whitespace after first token */ 392 *s += strspn(*s + 1, WHITESPACE) + 1; 393 if (split_equals && *s[0] == '=' && !wspace) 394 *s += strspn(*s + 1, WHITESPACE) + 1; 395 396 return (old); 397 } 398 399 /* 400 * Return next token in configuration line; splts on whitespace or a 401 * single '=' character. 402 */ 403 char * 404 strdelim(char **s) 405 { 406 return strdelim_internal(s, 1); 407 } 408 409 /* 410 * Return next token in configuration line; splts on whitespace only. 411 */ 412 char * 413 strdelimw(char **s) 414 { 415 return strdelim_internal(s, 0); 416 } 417 418 struct passwd * 419 pwcopy(struct passwd *pw) 420 { 421 struct passwd *copy = xcalloc(1, sizeof(*copy)); 422 423 copy->pw_name = xstrdup(pw->pw_name); 424 copy->pw_passwd = xstrdup(pw->pw_passwd); 425 copy->pw_gecos = xstrdup(pw->pw_gecos); 426 copy->pw_uid = pw->pw_uid; 427 copy->pw_gid = pw->pw_gid; 428 copy->pw_expire = pw->pw_expire; 429 copy->pw_change = pw->pw_change; 430 copy->pw_class = xstrdup(pw->pw_class); 431 copy->pw_dir = xstrdup(pw->pw_dir); 432 copy->pw_shell = xstrdup(pw->pw_shell); 433 return copy; 434 } 435 436 /* 437 * Convert ASCII string to TCP/IP port number. 438 * Port must be >=0 and <=65535. 439 * Return -1 if invalid. 440 */ 441 int 442 a2port(const char *s) 443 { 444 struct servent *se; 445 long long port; 446 const char *errstr; 447 448 port = strtonum(s, 0, 65535, &errstr); 449 if (errstr == NULL) 450 return (int)port; 451 if ((se = getservbyname(s, "tcp")) != NULL) 452 return ntohs(se->s_port); 453 return -1; 454 } 455 456 int 457 a2tun(const char *s, int *remote) 458 { 459 const char *errstr = NULL; 460 char *sp, *ep; 461 int tun; 462 463 if (remote != NULL) { 464 *remote = SSH_TUNID_ANY; 465 sp = xstrdup(s); 466 if ((ep = strchr(sp, ':')) == NULL) { 467 free(sp); 468 return (a2tun(s, NULL)); 469 } 470 ep[0] = '\0'; ep++; 471 *remote = a2tun(ep, NULL); 472 tun = a2tun(sp, NULL); 473 free(sp); 474 return (*remote == SSH_TUNID_ERR ? *remote : tun); 475 } 476 477 if (strcasecmp(s, "any") == 0) 478 return (SSH_TUNID_ANY); 479 480 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 481 if (errstr != NULL) 482 return (SSH_TUNID_ERR); 483 484 return (tun); 485 } 486 487 #define SECONDS 1 488 #define MINUTES (SECONDS * 60) 489 #define HOURS (MINUTES * 60) 490 #define DAYS (HOURS * 24) 491 #define WEEKS (DAYS * 7) 492 493 /* 494 * Convert a time string into seconds; format is 495 * a sequence of: 496 * time[qualifier] 497 * 498 * Valid time qualifiers are: 499 * <none> seconds 500 * s|S seconds 501 * m|M minutes 502 * h|H hours 503 * d|D days 504 * w|W weeks 505 * 506 * Examples: 507 * 90m 90 minutes 508 * 1h30m 90 minutes 509 * 2d 2 days 510 * 1w 1 week 511 * 512 * Return -1 if time string is invalid. 513 */ 514 int 515 convtime(const char *s) 516 { 517 long total, secs, multiplier; 518 const char *p; 519 char *endp; 520 521 errno = 0; 522 total = 0; 523 p = s; 524 525 if (p == NULL || *p == '\0') 526 return -1; 527 528 while (*p) { 529 secs = strtol(p, &endp, 10); 530 if (p == endp || 531 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 532 secs < 0) 533 return -1; 534 535 multiplier = 1; 536 switch (*endp++) { 537 case '\0': 538 endp--; 539 break; 540 case 's': 541 case 'S': 542 break; 543 case 'm': 544 case 'M': 545 multiplier = MINUTES; 546 break; 547 case 'h': 548 case 'H': 549 multiplier = HOURS; 550 break; 551 case 'd': 552 case 'D': 553 multiplier = DAYS; 554 break; 555 case 'w': 556 case 'W': 557 multiplier = WEEKS; 558 break; 559 default: 560 return -1; 561 } 562 if (secs > INT_MAX / multiplier) 563 return -1; 564 secs *= multiplier; 565 if (total > INT_MAX - secs) 566 return -1; 567 total += secs; 568 if (total < 0) 569 return -1; 570 p = endp; 571 } 572 573 return total; 574 } 575 576 #define TF_BUFS 8 577 #define TF_LEN 9 578 579 const char * 580 fmt_timeframe(time_t t) 581 { 582 char *buf; 583 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 584 static int idx = 0; 585 unsigned int sec, min, hrs, day; 586 unsigned long long week; 587 588 buf = tfbuf[idx++]; 589 if (idx == TF_BUFS) 590 idx = 0; 591 592 week = t; 593 594 sec = week % 60; 595 week /= 60; 596 min = week % 60; 597 week /= 60; 598 hrs = week % 24; 599 week /= 24; 600 day = week % 7; 601 week /= 7; 602 603 if (week > 0) 604 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 605 else if (day > 0) 606 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 607 else 608 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 609 610 return (buf); 611 } 612 613 /* 614 * Returns a standardized host+port identifier string. 615 * Caller must free returned string. 616 */ 617 char * 618 put_host_port(const char *host, u_short port) 619 { 620 char *hoststr; 621 622 if (port == 0 || port == SSH_DEFAULT_PORT) 623 return(xstrdup(host)); 624 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 625 fatal("put_host_port: asprintf: %s", strerror(errno)); 626 debug3("put_host_port: %s", hoststr); 627 return hoststr; 628 } 629 630 /* 631 * Search for next delimiter between hostnames/addresses and ports. 632 * Argument may be modified (for termination). 633 * Returns *cp if parsing succeeds. 634 * *cp is set to the start of the next field, if one was found. 635 * The delimiter char, if present, is stored in delim. 636 * If this is the last field, *cp is set to NULL. 637 */ 638 char * 639 hpdelim2(char **cp, char *delim) 640 { 641 char *s, *old; 642 643 if (cp == NULL || *cp == NULL) 644 return NULL; 645 646 old = s = *cp; 647 if (*s == '[') { 648 if ((s = strchr(s, ']')) == NULL) 649 return NULL; 650 else 651 s++; 652 } else if ((s = strpbrk(s, ":/")) == NULL) 653 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 654 655 switch (*s) { 656 case '\0': 657 *cp = NULL; /* no more fields*/ 658 break; 659 660 case ':': 661 case '/': 662 if (delim != NULL) 663 *delim = *s; 664 *s = '\0'; /* terminate */ 665 *cp = s + 1; 666 break; 667 668 default: 669 return NULL; 670 } 671 672 return old; 673 } 674 675 char * 676 hpdelim(char **cp) 677 { 678 return hpdelim2(cp, NULL); 679 } 680 681 char * 682 cleanhostname(char *host) 683 { 684 if (*host == '[' && host[strlen(host) - 1] == ']') { 685 host[strlen(host) - 1] = '\0'; 686 return (host + 1); 687 } else 688 return host; 689 } 690 691 char * 692 colon(char *cp) 693 { 694 int flag = 0; 695 696 if (*cp == ':') /* Leading colon is part of file name. */ 697 return NULL; 698 if (*cp == '[') 699 flag = 1; 700 701 for (; *cp; ++cp) { 702 if (*cp == '@' && *(cp+1) == '[') 703 flag = 1; 704 if (*cp == ']' && *(cp+1) == ':' && flag) 705 return (cp+1); 706 if (*cp == ':' && !flag) 707 return (cp); 708 if (*cp == '/') 709 return NULL; 710 } 711 return NULL; 712 } 713 714 /* 715 * Parse a [user@]host:[path] string. 716 * Caller must free returned user, host and path. 717 * Any of the pointer return arguments may be NULL (useful for syntax checking). 718 * If user was not specified then *userp will be set to NULL. 719 * If host was not specified then *hostp will be set to NULL. 720 * If path was not specified then *pathp will be set to ".". 721 * Returns 0 on success, -1 on failure. 722 */ 723 int 724 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 725 { 726 char *user = NULL, *host = NULL, *path = NULL; 727 char *sdup, *tmp; 728 int ret = -1; 729 730 if (userp != NULL) 731 *userp = NULL; 732 if (hostp != NULL) 733 *hostp = NULL; 734 if (pathp != NULL) 735 *pathp = NULL; 736 737 sdup = xstrdup(s); 738 739 /* Check for remote syntax: [user@]host:[path] */ 740 if ((tmp = colon(sdup)) == NULL) 741 goto out; 742 743 /* Extract optional path */ 744 *tmp++ = '\0'; 745 if (*tmp == '\0') 746 tmp = "."; 747 path = xstrdup(tmp); 748 749 /* Extract optional user and mandatory host */ 750 tmp = strrchr(sdup, '@'); 751 if (tmp != NULL) { 752 *tmp++ = '\0'; 753 host = xstrdup(cleanhostname(tmp)); 754 if (*sdup != '\0') 755 user = xstrdup(sdup); 756 } else { 757 host = xstrdup(cleanhostname(sdup)); 758 user = NULL; 759 } 760 761 /* Success */ 762 if (userp != NULL) { 763 *userp = user; 764 user = NULL; 765 } 766 if (hostp != NULL) { 767 *hostp = host; 768 host = NULL; 769 } 770 if (pathp != NULL) { 771 *pathp = path; 772 path = NULL; 773 } 774 ret = 0; 775 out: 776 free(sdup); 777 free(user); 778 free(host); 779 free(path); 780 return ret; 781 } 782 783 /* 784 * Parse a [user@]host[:port] string. 785 * Caller must free returned user and host. 786 * Any of the pointer return arguments may be NULL (useful for syntax checking). 787 * If user was not specified then *userp will be set to NULL. 788 * If port was not specified then *portp will be -1. 789 * Returns 0 on success, -1 on failure. 790 */ 791 int 792 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 793 { 794 char *sdup, *cp, *tmp; 795 char *user = NULL, *host = NULL; 796 int port = -1, ret = -1; 797 798 if (userp != NULL) 799 *userp = NULL; 800 if (hostp != NULL) 801 *hostp = NULL; 802 if (portp != NULL) 803 *portp = -1; 804 805 if ((sdup = tmp = strdup(s)) == NULL) 806 return -1; 807 /* Extract optional username */ 808 if ((cp = strrchr(tmp, '@')) != NULL) { 809 *cp = '\0'; 810 if (*tmp == '\0') 811 goto out; 812 if ((user = strdup(tmp)) == NULL) 813 goto out; 814 tmp = cp + 1; 815 } 816 /* Extract mandatory hostname */ 817 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 818 goto out; 819 host = xstrdup(cleanhostname(cp)); 820 /* Convert and verify optional port */ 821 if (tmp != NULL && *tmp != '\0') { 822 if ((port = a2port(tmp)) <= 0) 823 goto out; 824 } 825 /* Success */ 826 if (userp != NULL) { 827 *userp = user; 828 user = NULL; 829 } 830 if (hostp != NULL) { 831 *hostp = host; 832 host = NULL; 833 } 834 if (portp != NULL) 835 *portp = port; 836 ret = 0; 837 out: 838 free(sdup); 839 free(user); 840 free(host); 841 return ret; 842 } 843 844 /* 845 * Converts a two-byte hex string to decimal. 846 * Returns the decimal value or -1 for invalid input. 847 */ 848 static int 849 hexchar(const char *s) 850 { 851 unsigned char result[2]; 852 int i; 853 854 for (i = 0; i < 2; i++) { 855 if (s[i] >= '0' && s[i] <= '9') 856 result[i] = (unsigned char)(s[i] - '0'); 857 else if (s[i] >= 'a' && s[i] <= 'f') 858 result[i] = (unsigned char)(s[i] - 'a') + 10; 859 else if (s[i] >= 'A' && s[i] <= 'F') 860 result[i] = (unsigned char)(s[i] - 'A') + 10; 861 else 862 return -1; 863 } 864 return (result[0] << 4) | result[1]; 865 } 866 867 /* 868 * Decode an url-encoded string. 869 * Returns a newly allocated string on success or NULL on failure. 870 */ 871 static char * 872 urldecode(const char *src) 873 { 874 char *ret, *dst; 875 int ch; 876 877 ret = xmalloc(strlen(src) + 1); 878 for (dst = ret; *src != '\0'; src++) { 879 switch (*src) { 880 case '+': 881 *dst++ = ' '; 882 break; 883 case '%': 884 if (!isxdigit((unsigned char)src[1]) || 885 !isxdigit((unsigned char)src[2]) || 886 (ch = hexchar(src + 1)) == -1) { 887 free(ret); 888 return NULL; 889 } 890 *dst++ = ch; 891 src += 2; 892 break; 893 default: 894 *dst++ = *src; 895 break; 896 } 897 } 898 *dst = '\0'; 899 900 return ret; 901 } 902 903 /* 904 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 905 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 906 * Either user or path may be url-encoded (but not host or port). 907 * Caller must free returned user, host and path. 908 * Any of the pointer return arguments may be NULL (useful for syntax checking) 909 * but the scheme must always be specified. 910 * If user was not specified then *userp will be set to NULL. 911 * If port was not specified then *portp will be -1. 912 * If path was not specified then *pathp will be set to NULL. 913 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 914 */ 915 int 916 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 917 int *portp, char **pathp) 918 { 919 char *uridup, *cp, *tmp, ch; 920 char *user = NULL, *host = NULL, *path = NULL; 921 int port = -1, ret = -1; 922 size_t len; 923 924 len = strlen(scheme); 925 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 926 return 1; 927 uri += len + 3; 928 929 if (userp != NULL) 930 *userp = NULL; 931 if (hostp != NULL) 932 *hostp = NULL; 933 if (portp != NULL) 934 *portp = -1; 935 if (pathp != NULL) 936 *pathp = NULL; 937 938 uridup = tmp = xstrdup(uri); 939 940 /* Extract optional ssh-info (username + connection params) */ 941 if ((cp = strchr(tmp, '@')) != NULL) { 942 char *delim; 943 944 *cp = '\0'; 945 /* Extract username and connection params */ 946 if ((delim = strchr(tmp, ';')) != NULL) { 947 /* Just ignore connection params for now */ 948 *delim = '\0'; 949 } 950 if (*tmp == '\0') { 951 /* Empty username */ 952 goto out; 953 } 954 if ((user = urldecode(tmp)) == NULL) 955 goto out; 956 tmp = cp + 1; 957 } 958 959 /* Extract mandatory hostname */ 960 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 961 goto out; 962 host = xstrdup(cleanhostname(cp)); 963 if (!valid_domain(host, 0, NULL)) 964 goto out; 965 966 if (tmp != NULL && *tmp != '\0') { 967 if (ch == ':') { 968 /* Convert and verify port. */ 969 if ((cp = strchr(tmp, '/')) != NULL) 970 *cp = '\0'; 971 if ((port = a2port(tmp)) <= 0) 972 goto out; 973 tmp = cp ? cp + 1 : NULL; 974 } 975 if (tmp != NULL && *tmp != '\0') { 976 /* Extract optional path */ 977 if ((path = urldecode(tmp)) == NULL) 978 goto out; 979 } 980 } 981 982 /* Success */ 983 if (userp != NULL) { 984 *userp = user; 985 user = NULL; 986 } 987 if (hostp != NULL) { 988 *hostp = host; 989 host = NULL; 990 } 991 if (portp != NULL) 992 *portp = port; 993 if (pathp != NULL) { 994 *pathp = path; 995 path = NULL; 996 } 997 ret = 0; 998 out: 999 free(uridup); 1000 free(user); 1001 free(host); 1002 free(path); 1003 return ret; 1004 } 1005 1006 /* function to assist building execv() arguments */ 1007 void 1008 addargs(arglist *args, char *fmt, ...) 1009 { 1010 va_list ap; 1011 char *cp; 1012 u_int nalloc; 1013 int r; 1014 1015 va_start(ap, fmt); 1016 r = vasprintf(&cp, fmt, ap); 1017 va_end(ap); 1018 if (r == -1) 1019 fatal("addargs: argument too long"); 1020 1021 nalloc = args->nalloc; 1022 if (args->list == NULL) { 1023 nalloc = 32; 1024 args->num = 0; 1025 } else if (args->num+2 >= nalloc) 1026 nalloc *= 2; 1027 1028 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 1029 args->nalloc = nalloc; 1030 args->list[args->num++] = cp; 1031 args->list[args->num] = NULL; 1032 } 1033 1034 void 1035 replacearg(arglist *args, u_int which, char *fmt, ...) 1036 { 1037 va_list ap; 1038 char *cp; 1039 int r; 1040 1041 va_start(ap, fmt); 1042 r = vasprintf(&cp, fmt, ap); 1043 va_end(ap); 1044 if (r == -1) 1045 fatal("replacearg: argument too long"); 1046 1047 if (which >= args->num) 1048 fatal("replacearg: tried to replace invalid arg %d >= %d", 1049 which, args->num); 1050 free(args->list[which]); 1051 args->list[which] = cp; 1052 } 1053 1054 void 1055 freeargs(arglist *args) 1056 { 1057 u_int i; 1058 1059 if (args->list != NULL) { 1060 for (i = 0; i < args->num; i++) 1061 free(args->list[i]); 1062 free(args->list); 1063 args->nalloc = args->num = 0; 1064 args->list = NULL; 1065 } 1066 } 1067 1068 /* 1069 * Expands tildes in the file name. Returns data allocated by xmalloc. 1070 * Warning: this calls getpw*. 1071 */ 1072 int 1073 tilde_expand(const char *filename, uid_t uid, char **retp) 1074 { 1075 char *ocopy = NULL, *copy, *s = NULL; 1076 const char *path = NULL, *user = NULL; 1077 struct passwd *pw; 1078 size_t len; 1079 int ret = -1, r, slash; 1080 1081 *retp = NULL; 1082 if (*filename != '~') { 1083 *retp = xstrdup(filename); 1084 return 0; 1085 } 1086 ocopy = copy = xstrdup(filename + 1); 1087 1088 if (*copy == '\0') /* ~ */ 1089 path = NULL; 1090 else if (*copy == '/') { 1091 copy += strspn(copy, "/"); 1092 if (*copy == '\0') 1093 path = NULL; /* ~/ */ 1094 else 1095 path = copy; /* ~/path */ 1096 } else { 1097 user = copy; 1098 if ((path = strchr(copy, '/')) != NULL) { 1099 copy[path - copy] = '\0'; 1100 path++; 1101 path += strspn(path, "/"); 1102 if (*path == '\0') /* ~user/ */ 1103 path = NULL; 1104 /* else ~user/path */ 1105 } 1106 /* else ~user */ 1107 } 1108 if (user != NULL) { 1109 if ((pw = getpwnam(user)) == NULL) { 1110 error_f("No such user %s", user); 1111 goto out; 1112 } 1113 } else if ((pw = getpwuid(uid)) == NULL) { 1114 error_f("No such uid %ld", (long)uid); 1115 goto out; 1116 } 1117 1118 /* Make sure directory has a trailing '/' */ 1119 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1120 1121 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1122 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1123 error_f("xasprintf failed"); 1124 goto out; 1125 } 1126 if (r >= PATH_MAX) { 1127 error_f("Path too long"); 1128 goto out; 1129 } 1130 /* success */ 1131 ret = 0; 1132 *retp = s; 1133 s = NULL; 1134 out: 1135 free(s); 1136 free(ocopy); 1137 return ret; 1138 } 1139 1140 char * 1141 tilde_expand_filename(const char *filename, uid_t uid) 1142 { 1143 char *ret; 1144 1145 if (tilde_expand(filename, uid, &ret) != 0) 1146 cleanup_exit(255); 1147 return ret; 1148 } 1149 1150 /* 1151 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1152 * substitutions. A number of escapes may be specified as 1153 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1154 * by a NULL escape_char. Returns replaced string in memory allocated by 1155 * xmalloc which the caller must free. 1156 */ 1157 static char * 1158 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1159 const char *string, va_list ap) 1160 { 1161 #define EXPAND_MAX_KEYS 16 1162 u_int num_keys = 0, i; 1163 struct { 1164 const char *key; 1165 const char *repl; 1166 } keys[EXPAND_MAX_KEYS]; 1167 struct sshbuf *buf; 1168 int r, missingvar = 0; 1169 char *ret = NULL, *var, *varend, *val; 1170 size_t len; 1171 1172 if ((buf = sshbuf_new()) == NULL) 1173 fatal_f("sshbuf_new failed"); 1174 if (parseerror == NULL) 1175 fatal_f("null parseerror arg"); 1176 *parseerror = 1; 1177 1178 /* Gather keys if we're doing percent expansion. */ 1179 if (percent) { 1180 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1181 keys[num_keys].key = va_arg(ap, char *); 1182 if (keys[num_keys].key == NULL) 1183 break; 1184 keys[num_keys].repl = va_arg(ap, char *); 1185 if (keys[num_keys].repl == NULL) { 1186 fatal_f("NULL replacement for token %s", 1187 keys[num_keys].key); 1188 } 1189 } 1190 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1191 fatal_f("too many keys"); 1192 if (num_keys == 0) 1193 fatal_f("percent expansion without token list"); 1194 } 1195 1196 /* Expand string */ 1197 for (i = 0; *string != '\0'; string++) { 1198 /* Optionally process ${ENVIRONMENT} expansions. */ 1199 if (dollar && string[0] == '$' && string[1] == '{') { 1200 string += 2; /* skip over '${' */ 1201 if ((varend = strchr(string, '}')) == NULL) { 1202 error_f("environment variable '%s' missing " 1203 "closing '}'", string); 1204 goto out; 1205 } 1206 len = varend - string; 1207 if (len == 0) { 1208 error_f("zero-length environment variable"); 1209 goto out; 1210 } 1211 var = xmalloc(len + 1); 1212 (void)strlcpy(var, string, len + 1); 1213 if ((val = getenv(var)) == NULL) { 1214 error_f("env var ${%s} has no value", var); 1215 missingvar = 1; 1216 } else { 1217 debug3_f("expand ${%s} -> '%s'", var, val); 1218 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1219 fatal_fr(r, "sshbuf_put ${}"); 1220 } 1221 free(var); 1222 string += len; 1223 continue; 1224 } 1225 1226 /* 1227 * Process percent expansions if we have a list of TOKENs. 1228 * If we're not doing percent expansion everything just gets 1229 * appended here. 1230 */ 1231 if (*string != '%' || !percent) { 1232 append: 1233 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1234 fatal_fr(r, "sshbuf_put_u8 %%"); 1235 continue; 1236 } 1237 string++; 1238 /* %% case */ 1239 if (*string == '%') 1240 goto append; 1241 if (*string == '\0') { 1242 error_f("invalid format"); 1243 goto out; 1244 } 1245 for (i = 0; i < num_keys; i++) { 1246 if (strchr(keys[i].key, *string) != NULL) { 1247 if ((r = sshbuf_put(buf, keys[i].repl, 1248 strlen(keys[i].repl))) != 0) 1249 fatal_fr(r, "sshbuf_put %%-repl"); 1250 break; 1251 } 1252 } 1253 if (i >= num_keys) { 1254 error_f("unknown key %%%c", *string); 1255 goto out; 1256 } 1257 } 1258 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1259 fatal_f("sshbuf_dup_string failed"); 1260 *parseerror = 0; 1261 out: 1262 sshbuf_free(buf); 1263 return *parseerror ? NULL : ret; 1264 #undef EXPAND_MAX_KEYS 1265 } 1266 1267 /* 1268 * Expand only environment variables. 1269 * Note that although this function is variadic like the other similar 1270 * functions, any such arguments will be unused. 1271 */ 1272 1273 char * 1274 dollar_expand(int *parseerr, const char *string, ...) 1275 { 1276 char *ret; 1277 int err; 1278 va_list ap; 1279 1280 va_start(ap, string); 1281 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1282 va_end(ap); 1283 if (parseerr != NULL) 1284 *parseerr = err; 1285 return ret; 1286 } 1287 1288 /* 1289 * Returns expanded string or NULL if a specified environment variable is 1290 * not defined, or calls fatal if the string is invalid. 1291 */ 1292 char * 1293 percent_expand(const char *string, ...) 1294 { 1295 char *ret; 1296 int err; 1297 va_list ap; 1298 1299 va_start(ap, string); 1300 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1301 va_end(ap); 1302 if (err) 1303 fatal_f("failed"); 1304 return ret; 1305 } 1306 1307 /* 1308 * Returns expanded string or NULL if a specified environment variable is 1309 * not defined, or calls fatal if the string is invalid. 1310 */ 1311 char * 1312 percent_dollar_expand(const char *string, ...) 1313 { 1314 char *ret; 1315 int err; 1316 va_list ap; 1317 1318 va_start(ap, string); 1319 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1320 va_end(ap); 1321 if (err) 1322 fatal_f("failed"); 1323 return ret; 1324 } 1325 1326 int 1327 tun_open(int tun, int mode, char **ifname) 1328 { 1329 struct ifreq ifr; 1330 char name[100]; 1331 int fd = -1, sock; 1332 const char *tunbase = "tun"; 1333 1334 if (ifname != NULL) 1335 *ifname = NULL; 1336 1337 if (mode == SSH_TUNMODE_ETHERNET) 1338 tunbase = "tap"; 1339 1340 /* Open the tunnel device */ 1341 if (tun <= SSH_TUNID_MAX) { 1342 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1343 fd = open(name, O_RDWR); 1344 } else if (tun == SSH_TUNID_ANY) { 1345 for (tun = 100; tun >= 0; tun--) { 1346 snprintf(name, sizeof(name), "/dev/%s%d", 1347 tunbase, tun); 1348 if ((fd = open(name, O_RDWR)) >= 0) 1349 break; 1350 } 1351 } else { 1352 debug_f("invalid tunnel %u", tun); 1353 return -1; 1354 } 1355 1356 if (fd == -1) { 1357 debug_f("%s open: %s", name, strerror(errno)); 1358 return -1; 1359 } 1360 1361 debug_f("%s mode %d fd %d", name, mode, fd); 1362 1363 /* Bring interface up if it is not already */ 1364 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1365 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1366 goto failed; 1367 1368 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1369 debug_f("get interface %s flags: %s", ifr.ifr_name, 1370 strerror(errno)); 1371 goto failed; 1372 } 1373 1374 if (!(ifr.ifr_flags & IFF_UP)) { 1375 ifr.ifr_flags |= IFF_UP; 1376 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1377 debug_f("activate interface %s: %s", ifr.ifr_name, 1378 strerror(errno)); 1379 goto failed; 1380 } 1381 } 1382 1383 if (ifname != NULL) 1384 *ifname = xstrdup(ifr.ifr_name); 1385 1386 close(sock); 1387 return fd; 1388 1389 failed: 1390 if (fd >= 0) 1391 close(fd); 1392 if (sock >= 0) 1393 close(sock); 1394 return -1; 1395 } 1396 1397 void 1398 sanitise_stdfd(void) 1399 { 1400 int nullfd, dupfd; 1401 1402 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1403 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1404 strerror(errno)); 1405 exit(1); 1406 } 1407 while (++dupfd <= STDERR_FILENO) { 1408 /* Only populate closed fds. */ 1409 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1410 if (dup2(nullfd, dupfd) == -1) { 1411 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1412 exit(1); 1413 } 1414 } 1415 } 1416 if (nullfd > STDERR_FILENO) 1417 close(nullfd); 1418 } 1419 1420 char * 1421 tohex(const void *vp, size_t l) 1422 { 1423 const u_char *p = (const u_char *)vp; 1424 char b[3], *r; 1425 size_t i, hl; 1426 1427 if (l > 65536) 1428 return xstrdup("tohex: length > 65536"); 1429 1430 hl = l * 2 + 1; 1431 r = xcalloc(1, hl); 1432 for (i = 0; i < l; i++) { 1433 snprintf(b, sizeof(b), "%02x", p[i]); 1434 strlcat(r, b, hl); 1435 } 1436 return (r); 1437 } 1438 1439 /* 1440 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1441 * then the separator 'sep' will be prepended before the formatted arguments. 1442 * Extended strings are heap allocated. 1443 */ 1444 void 1445 xextendf(char **sp, const char *sep, const char *fmt, ...) 1446 { 1447 va_list ap; 1448 char *tmp1, *tmp2; 1449 1450 va_start(ap, fmt); 1451 xvasprintf(&tmp1, fmt, ap); 1452 va_end(ap); 1453 1454 if (*sp == NULL || **sp == '\0') { 1455 free(*sp); 1456 *sp = tmp1; 1457 return; 1458 } 1459 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1460 free(tmp1); 1461 free(*sp); 1462 *sp = tmp2; 1463 } 1464 1465 1466 u_int64_t 1467 get_u64(const void *vp) 1468 { 1469 const u_char *p = (const u_char *)vp; 1470 u_int64_t v; 1471 1472 v = (u_int64_t)p[0] << 56; 1473 v |= (u_int64_t)p[1] << 48; 1474 v |= (u_int64_t)p[2] << 40; 1475 v |= (u_int64_t)p[3] << 32; 1476 v |= (u_int64_t)p[4] << 24; 1477 v |= (u_int64_t)p[5] << 16; 1478 v |= (u_int64_t)p[6] << 8; 1479 v |= (u_int64_t)p[7]; 1480 1481 return (v); 1482 } 1483 1484 u_int32_t 1485 get_u32(const void *vp) 1486 { 1487 const u_char *p = (const u_char *)vp; 1488 u_int32_t v; 1489 1490 v = (u_int32_t)p[0] << 24; 1491 v |= (u_int32_t)p[1] << 16; 1492 v |= (u_int32_t)p[2] << 8; 1493 v |= (u_int32_t)p[3]; 1494 1495 return (v); 1496 } 1497 1498 u_int32_t 1499 get_u32_le(const void *vp) 1500 { 1501 const u_char *p = (const u_char *)vp; 1502 u_int32_t v; 1503 1504 v = (u_int32_t)p[0]; 1505 v |= (u_int32_t)p[1] << 8; 1506 v |= (u_int32_t)p[2] << 16; 1507 v |= (u_int32_t)p[3] << 24; 1508 1509 return (v); 1510 } 1511 1512 u_int16_t 1513 get_u16(const void *vp) 1514 { 1515 const u_char *p = (const u_char *)vp; 1516 u_int16_t v; 1517 1518 v = (u_int16_t)p[0] << 8; 1519 v |= (u_int16_t)p[1]; 1520 1521 return (v); 1522 } 1523 1524 void 1525 put_u64(void *vp, u_int64_t v) 1526 { 1527 u_char *p = (u_char *)vp; 1528 1529 p[0] = (u_char)(v >> 56) & 0xff; 1530 p[1] = (u_char)(v >> 48) & 0xff; 1531 p[2] = (u_char)(v >> 40) & 0xff; 1532 p[3] = (u_char)(v >> 32) & 0xff; 1533 p[4] = (u_char)(v >> 24) & 0xff; 1534 p[5] = (u_char)(v >> 16) & 0xff; 1535 p[6] = (u_char)(v >> 8) & 0xff; 1536 p[7] = (u_char)v & 0xff; 1537 } 1538 1539 void 1540 put_u32(void *vp, u_int32_t v) 1541 { 1542 u_char *p = (u_char *)vp; 1543 1544 p[0] = (u_char)(v >> 24) & 0xff; 1545 p[1] = (u_char)(v >> 16) & 0xff; 1546 p[2] = (u_char)(v >> 8) & 0xff; 1547 p[3] = (u_char)v & 0xff; 1548 } 1549 1550 void 1551 put_u32_le(void *vp, u_int32_t v) 1552 { 1553 u_char *p = (u_char *)vp; 1554 1555 p[0] = (u_char)v & 0xff; 1556 p[1] = (u_char)(v >> 8) & 0xff; 1557 p[2] = (u_char)(v >> 16) & 0xff; 1558 p[3] = (u_char)(v >> 24) & 0xff; 1559 } 1560 1561 void 1562 put_u16(void *vp, u_int16_t v) 1563 { 1564 u_char *p = (u_char *)vp; 1565 1566 p[0] = (u_char)(v >> 8) & 0xff; 1567 p[1] = (u_char)v & 0xff; 1568 } 1569 1570 void 1571 ms_subtract_diff(struct timeval *start, int *ms) 1572 { 1573 struct timeval diff, finish; 1574 1575 monotime_tv(&finish); 1576 timersub(&finish, start, &diff); 1577 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1578 } 1579 1580 void 1581 ms_to_timespec(struct timespec *ts, int ms) 1582 { 1583 if (ms < 0) 1584 ms = 0; 1585 ts->tv_sec = ms / 1000; 1586 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1587 } 1588 1589 void 1590 monotime_ts(struct timespec *ts) 1591 { 1592 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1593 fatal("clock_gettime: %s", strerror(errno)); 1594 } 1595 1596 void 1597 monotime_tv(struct timeval *tv) 1598 { 1599 struct timespec ts; 1600 1601 monotime_ts(&ts); 1602 tv->tv_sec = ts.tv_sec; 1603 tv->tv_usec = ts.tv_nsec / 1000; 1604 } 1605 1606 time_t 1607 monotime(void) 1608 { 1609 struct timespec ts; 1610 1611 monotime_ts(&ts); 1612 return (ts.tv_sec); 1613 } 1614 1615 double 1616 monotime_double(void) 1617 { 1618 struct timespec ts; 1619 1620 monotime_ts(&ts); 1621 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1622 } 1623 1624 void 1625 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1626 { 1627 bw->buflen = buflen; 1628 bw->rate = kbps; 1629 bw->thresh = buflen; 1630 bw->lamt = 0; 1631 timerclear(&bw->bwstart); 1632 timerclear(&bw->bwend); 1633 } 1634 1635 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1636 void 1637 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1638 { 1639 u_int64_t waitlen; 1640 struct timespec ts, rm; 1641 1642 bw->lamt += read_len; 1643 if (!timerisset(&bw->bwstart)) { 1644 monotime_tv(&bw->bwstart); 1645 return; 1646 } 1647 if (bw->lamt < bw->thresh) 1648 return; 1649 1650 monotime_tv(&bw->bwend); 1651 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1652 if (!timerisset(&bw->bwend)) 1653 return; 1654 1655 bw->lamt *= 8; 1656 waitlen = (double)1000000L * bw->lamt / bw->rate; 1657 1658 bw->bwstart.tv_sec = waitlen / 1000000L; 1659 bw->bwstart.tv_usec = waitlen % 1000000L; 1660 1661 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1662 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1663 1664 /* Adjust the wait time */ 1665 if (bw->bwend.tv_sec) { 1666 bw->thresh /= 2; 1667 if (bw->thresh < bw->buflen / 4) 1668 bw->thresh = bw->buflen / 4; 1669 } else if (bw->bwend.tv_usec < 10000) { 1670 bw->thresh *= 2; 1671 if (bw->thresh > bw->buflen * 8) 1672 bw->thresh = bw->buflen * 8; 1673 } 1674 1675 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1676 while (nanosleep(&ts, &rm) == -1) { 1677 if (errno != EINTR) 1678 break; 1679 ts = rm; 1680 } 1681 } 1682 1683 bw->lamt = 0; 1684 monotime_tv(&bw->bwstart); 1685 } 1686 1687 /* Make a template filename for mk[sd]temp() */ 1688 void 1689 mktemp_proto(char *s, size_t len) 1690 { 1691 const char *tmpdir; 1692 int r; 1693 1694 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1695 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1696 if (r > 0 && (size_t)r < len) 1697 return; 1698 } 1699 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1700 if (r < 0 || (size_t)r >= len) 1701 fatal_f("template string too short"); 1702 } 1703 1704 static const struct { 1705 const char *name; 1706 int value; 1707 } ipqos[] = { 1708 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1709 { "af11", IPTOS_DSCP_AF11 }, 1710 { "af12", IPTOS_DSCP_AF12 }, 1711 { "af13", IPTOS_DSCP_AF13 }, 1712 { "af21", IPTOS_DSCP_AF21 }, 1713 { "af22", IPTOS_DSCP_AF22 }, 1714 { "af23", IPTOS_DSCP_AF23 }, 1715 { "af31", IPTOS_DSCP_AF31 }, 1716 { "af32", IPTOS_DSCP_AF32 }, 1717 { "af33", IPTOS_DSCP_AF33 }, 1718 { "af41", IPTOS_DSCP_AF41 }, 1719 { "af42", IPTOS_DSCP_AF42 }, 1720 { "af43", IPTOS_DSCP_AF43 }, 1721 { "cs0", IPTOS_DSCP_CS0 }, 1722 { "cs1", IPTOS_DSCP_CS1 }, 1723 { "cs2", IPTOS_DSCP_CS2 }, 1724 { "cs3", IPTOS_DSCP_CS3 }, 1725 { "cs4", IPTOS_DSCP_CS4 }, 1726 { "cs5", IPTOS_DSCP_CS5 }, 1727 { "cs6", IPTOS_DSCP_CS6 }, 1728 { "cs7", IPTOS_DSCP_CS7 }, 1729 { "ef", IPTOS_DSCP_EF }, 1730 { "le", IPTOS_DSCP_LE }, 1731 { "lowdelay", IPTOS_LOWDELAY }, 1732 { "throughput", IPTOS_THROUGHPUT }, 1733 { "reliability", IPTOS_RELIABILITY }, 1734 { NULL, -1 } 1735 }; 1736 1737 int 1738 parse_ipqos(const char *cp) 1739 { 1740 u_int i; 1741 char *ep; 1742 long val; 1743 1744 if (cp == NULL) 1745 return -1; 1746 for (i = 0; ipqos[i].name != NULL; i++) { 1747 if (strcasecmp(cp, ipqos[i].name) == 0) 1748 return ipqos[i].value; 1749 } 1750 /* Try parsing as an integer */ 1751 val = strtol(cp, &ep, 0); 1752 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1753 return -1; 1754 return val; 1755 } 1756 1757 const char * 1758 iptos2str(int iptos) 1759 { 1760 int i; 1761 static char iptos_str[sizeof "0xff"]; 1762 1763 for (i = 0; ipqos[i].name != NULL; i++) { 1764 if (ipqos[i].value == iptos) 1765 return ipqos[i].name; 1766 } 1767 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1768 return iptos_str; 1769 } 1770 1771 void 1772 lowercase(char *s) 1773 { 1774 for (; *s; s++) 1775 *s = tolower((u_char)*s); 1776 } 1777 1778 int 1779 unix_listener(const char *path, int backlog, int unlink_first) 1780 { 1781 struct sockaddr_un sunaddr; 1782 int saved_errno, sock; 1783 1784 memset(&sunaddr, 0, sizeof(sunaddr)); 1785 sunaddr.sun_family = AF_UNIX; 1786 if (strlcpy(sunaddr.sun_path, path, 1787 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1788 error_f("path \"%s\" too long for Unix domain socket", path); 1789 errno = ENAMETOOLONG; 1790 return -1; 1791 } 1792 1793 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1794 if (sock == -1) { 1795 saved_errno = errno; 1796 error_f("socket: %.100s", strerror(errno)); 1797 errno = saved_errno; 1798 return -1; 1799 } 1800 if (unlink_first == 1) { 1801 if (unlink(path) != 0 && errno != ENOENT) 1802 error("unlink(%s): %.100s", path, strerror(errno)); 1803 } 1804 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1805 saved_errno = errno; 1806 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1807 close(sock); 1808 errno = saved_errno; 1809 return -1; 1810 } 1811 if (listen(sock, backlog) == -1) { 1812 saved_errno = errno; 1813 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1814 close(sock); 1815 unlink(path); 1816 errno = saved_errno; 1817 return -1; 1818 } 1819 return sock; 1820 } 1821 1822 /* 1823 * Compares two strings that maybe be NULL. Returns non-zero if strings 1824 * are both NULL or are identical, returns zero otherwise. 1825 */ 1826 static int 1827 strcmp_maybe_null(const char *a, const char *b) 1828 { 1829 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1830 return 0; 1831 if (a != NULL && strcmp(a, b) != 0) 1832 return 0; 1833 return 1; 1834 } 1835 1836 /* 1837 * Compare two forwards, returning non-zero if they are identical or 1838 * zero otherwise. 1839 */ 1840 int 1841 forward_equals(const struct Forward *a, const struct Forward *b) 1842 { 1843 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1844 return 0; 1845 if (a->listen_port != b->listen_port) 1846 return 0; 1847 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1848 return 0; 1849 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1850 return 0; 1851 if (a->connect_port != b->connect_port) 1852 return 0; 1853 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1854 return 0; 1855 /* allocated_port and handle are not checked */ 1856 return 1; 1857 } 1858 1859 /* returns 1 if process is already daemonized, 0 otherwise */ 1860 int 1861 daemonized(void) 1862 { 1863 int fd; 1864 1865 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1866 close(fd); 1867 return 0; /* have controlling terminal */ 1868 } 1869 if (getppid() != 1) 1870 return 0; /* parent is not init */ 1871 if (getsid(0) != getpid()) 1872 return 0; /* not session leader */ 1873 debug3("already daemonized"); 1874 return 1; 1875 } 1876 1877 /* 1878 * Splits 's' into an argument vector. Handles quoted string and basic 1879 * escape characters (\\, \", \'). Caller must free the argument vector 1880 * and its members. 1881 */ 1882 int 1883 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1884 { 1885 int r = SSH_ERR_INTERNAL_ERROR; 1886 int argc = 0, quote, i, j; 1887 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1888 1889 *argvp = NULL; 1890 *argcp = 0; 1891 1892 for (i = 0; s[i] != '\0'; i++) { 1893 /* Skip leading whitespace */ 1894 if (s[i] == ' ' || s[i] == '\t') 1895 continue; 1896 if (terminate_on_comment && s[i] == '#') 1897 break; 1898 /* Start of a token */ 1899 quote = 0; 1900 1901 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1902 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1903 argv[argc] = NULL; 1904 1905 /* Copy the token in, removing escapes */ 1906 for (j = 0; s[i] != '\0'; i++) { 1907 if (s[i] == '\\') { 1908 if (s[i + 1] == '\'' || 1909 s[i + 1] == '\"' || 1910 s[i + 1] == '\\' || 1911 (quote == 0 && s[i + 1] == ' ')) { 1912 i++; /* Skip '\' */ 1913 arg[j++] = s[i]; 1914 } else { 1915 /* Unrecognised escape */ 1916 arg[j++] = s[i]; 1917 } 1918 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1919 break; /* done */ 1920 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1921 quote = s[i]; /* quote start */ 1922 else if (quote != 0 && s[i] == quote) 1923 quote = 0; /* quote end */ 1924 else 1925 arg[j++] = s[i]; 1926 } 1927 if (s[i] == '\0') { 1928 if (quote != 0) { 1929 /* Ran out of string looking for close quote */ 1930 r = SSH_ERR_INVALID_FORMAT; 1931 goto out; 1932 } 1933 break; 1934 } 1935 } 1936 /* Success */ 1937 *argcp = argc; 1938 *argvp = argv; 1939 argc = 0; 1940 argv = NULL; 1941 r = 0; 1942 out: 1943 if (argc != 0 && argv != NULL) { 1944 for (i = 0; i < argc; i++) 1945 free(argv[i]); 1946 free(argv); 1947 } 1948 return r; 1949 } 1950 1951 /* 1952 * Reassemble an argument vector into a string, quoting and escaping as 1953 * necessary. Caller must free returned string. 1954 */ 1955 char * 1956 argv_assemble(int argc, char **argv) 1957 { 1958 int i, j, ws, r; 1959 char c, *ret; 1960 struct sshbuf *buf, *arg; 1961 1962 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1963 fatal_f("sshbuf_new failed"); 1964 1965 for (i = 0; i < argc; i++) { 1966 ws = 0; 1967 sshbuf_reset(arg); 1968 for (j = 0; argv[i][j] != '\0'; j++) { 1969 r = 0; 1970 c = argv[i][j]; 1971 switch (c) { 1972 case ' ': 1973 case '\t': 1974 ws = 1; 1975 r = sshbuf_put_u8(arg, c); 1976 break; 1977 case '\\': 1978 case '\'': 1979 case '"': 1980 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 1981 break; 1982 /* FALLTHROUGH */ 1983 default: 1984 r = sshbuf_put_u8(arg, c); 1985 break; 1986 } 1987 if (r != 0) 1988 fatal_fr(r, "sshbuf_put_u8"); 1989 } 1990 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 1991 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 1992 (r = sshbuf_putb(buf, arg)) != 0 || 1993 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 1994 fatal_fr(r, "assemble"); 1995 } 1996 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 1997 fatal_f("malloc failed"); 1998 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 1999 ret[sshbuf_len(buf)] = '\0'; 2000 sshbuf_free(buf); 2001 sshbuf_free(arg); 2002 return ret; 2003 } 2004 2005 char * 2006 argv_next(int *argcp, char ***argvp) 2007 { 2008 char *ret = (*argvp)[0]; 2009 2010 if (*argcp > 0 && ret != NULL) { 2011 (*argcp)--; 2012 (*argvp)++; 2013 } 2014 return ret; 2015 } 2016 2017 void 2018 argv_consume(int *argcp) 2019 { 2020 *argcp = 0; 2021 } 2022 2023 void 2024 argv_free(char **av, int ac) 2025 { 2026 int i; 2027 2028 if (av == NULL) 2029 return; 2030 for (i = 0; i < ac; i++) 2031 free(av[i]); 2032 free(av); 2033 } 2034 2035 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2036 int 2037 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2038 { 2039 int status; 2040 2041 while (waitpid(pid, &status, 0) == -1) { 2042 if (errno != EINTR) { 2043 error("%s waitpid: %s", tag, strerror(errno)); 2044 return -1; 2045 } 2046 } 2047 if (WIFSIGNALED(status)) { 2048 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2049 return -1; 2050 } else if (WEXITSTATUS(status) != 0) { 2051 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2052 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2053 return -1; 2054 } 2055 return 0; 2056 } 2057 2058 /* 2059 * Check a given path for security. This is defined as all components 2060 * of the path to the file must be owned by either the owner of 2061 * of the file or root and no directories must be group or world writable. 2062 * 2063 * XXX Should any specific check be done for sym links ? 2064 * 2065 * Takes a file name, its stat information (preferably from fstat() to 2066 * avoid races), the uid of the expected owner, their home directory and an 2067 * error buffer plus max size as arguments. 2068 * 2069 * Returns 0 on success and -1 on failure 2070 */ 2071 int 2072 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2073 uid_t uid, char *err, size_t errlen) 2074 { 2075 char buf[PATH_MAX], homedir[PATH_MAX]; 2076 char *cp; 2077 int comparehome = 0; 2078 struct stat st; 2079 2080 if (realpath(name, buf) == NULL) { 2081 snprintf(err, errlen, "realpath %s failed: %s", name, 2082 strerror(errno)); 2083 return -1; 2084 } 2085 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2086 comparehome = 1; 2087 2088 if (!S_ISREG(stp->st_mode)) { 2089 snprintf(err, errlen, "%s is not a regular file", buf); 2090 return -1; 2091 } 2092 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2093 (stp->st_mode & 022) != 0) { 2094 snprintf(err, errlen, "bad ownership or modes for file %s", 2095 buf); 2096 return -1; 2097 } 2098 2099 /* for each component of the canonical path, walking upwards */ 2100 for (;;) { 2101 if ((cp = dirname(buf)) == NULL) { 2102 snprintf(err, errlen, "dirname() failed"); 2103 return -1; 2104 } 2105 strlcpy(buf, cp, sizeof(buf)); 2106 2107 if (stat(buf, &st) == -1 || 2108 (st.st_uid != 0 && st.st_uid != uid) || 2109 (st.st_mode & 022) != 0) { 2110 snprintf(err, errlen, 2111 "bad ownership or modes for directory %s", buf); 2112 return -1; 2113 } 2114 2115 /* If are past the homedir then we can stop */ 2116 if (comparehome && strcmp(homedir, buf) == 0) 2117 break; 2118 2119 /* 2120 * dirname should always complete with a "/" path, 2121 * but we can be paranoid and check for "." too 2122 */ 2123 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2124 break; 2125 } 2126 return 0; 2127 } 2128 2129 /* 2130 * Version of safe_path() that accepts an open file descriptor to 2131 * avoid races. 2132 * 2133 * Returns 0 on success and -1 on failure 2134 */ 2135 int 2136 safe_path_fd(int fd, const char *file, struct passwd *pw, 2137 char *err, size_t errlen) 2138 { 2139 struct stat st; 2140 2141 /* check the open file to avoid races */ 2142 if (fstat(fd, &st) == -1) { 2143 snprintf(err, errlen, "cannot stat file %s: %s", 2144 file, strerror(errno)); 2145 return -1; 2146 } 2147 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2148 } 2149 2150 /* 2151 * Sets the value of the given variable in the environment. If the variable 2152 * already exists, its value is overridden. 2153 */ 2154 void 2155 child_set_env(char ***envp, u_int *envsizep, const char *name, 2156 const char *value) 2157 { 2158 char **env; 2159 u_int envsize; 2160 u_int i, namelen; 2161 2162 if (strchr(name, '=') != NULL) { 2163 error("Invalid environment variable \"%.100s\"", name); 2164 return; 2165 } 2166 2167 /* 2168 * Find the slot where the value should be stored. If the variable 2169 * already exists, we reuse the slot; otherwise we append a new slot 2170 * at the end of the array, expanding if necessary. 2171 */ 2172 env = *envp; 2173 namelen = strlen(name); 2174 for (i = 0; env[i]; i++) 2175 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2176 break; 2177 if (env[i]) { 2178 /* Reuse the slot. */ 2179 free(env[i]); 2180 } else { 2181 /* New variable. Expand if necessary. */ 2182 envsize = *envsizep; 2183 if (i >= envsize - 1) { 2184 if (envsize >= 1000) 2185 fatal("child_set_env: too many env vars"); 2186 envsize += 50; 2187 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2188 *envsizep = envsize; 2189 } 2190 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2191 env[i + 1] = NULL; 2192 } 2193 2194 /* Allocate space and format the variable in the appropriate slot. */ 2195 /* XXX xasprintf */ 2196 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2197 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2198 } 2199 2200 /* 2201 * Check and optionally lowercase a domain name, also removes trailing '.' 2202 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2203 */ 2204 int 2205 valid_domain(char *name, int makelower, const char **errstr) 2206 { 2207 size_t i, l = strlen(name); 2208 u_char c, last = '\0'; 2209 static char errbuf[256]; 2210 2211 if (l == 0) { 2212 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2213 goto bad; 2214 } 2215 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2216 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2217 "starts with invalid character", name); 2218 goto bad; 2219 } 2220 for (i = 0; i < l; i++) { 2221 c = tolower((u_char)name[i]); 2222 if (makelower) 2223 name[i] = (char)c; 2224 if (last == '.' && c == '.') { 2225 snprintf(errbuf, sizeof(errbuf), "domain name " 2226 "\"%.100s\" contains consecutive separators", name); 2227 goto bad; 2228 } 2229 if (c != '.' && c != '-' && !isalnum(c) && 2230 c != '_') /* technically invalid, but common */ { 2231 snprintf(errbuf, sizeof(errbuf), "domain name " 2232 "\"%.100s\" contains invalid characters", name); 2233 goto bad; 2234 } 2235 last = c; 2236 } 2237 if (name[l - 1] == '.') 2238 name[l - 1] = '\0'; 2239 if (errstr != NULL) 2240 *errstr = NULL; 2241 return 1; 2242 bad: 2243 if (errstr != NULL) 2244 *errstr = errbuf; 2245 return 0; 2246 } 2247 2248 /* 2249 * Verify that a environment variable name (not including initial '$') is 2250 * valid; consisting of one or more alphanumeric or underscore characters only. 2251 * Returns 1 on valid, 0 otherwise. 2252 */ 2253 int 2254 valid_env_name(const char *name) 2255 { 2256 const char *cp; 2257 2258 if (name[0] == '\0') 2259 return 0; 2260 for (cp = name; *cp != '\0'; cp++) { 2261 if (!isalnum((u_char)*cp) && *cp != '_') 2262 return 0; 2263 } 2264 return 1; 2265 } 2266 2267 const char * 2268 atoi_err(const char *nptr, int *val) 2269 { 2270 const char *errstr = NULL; 2271 long long num; 2272 2273 if (nptr == NULL || *nptr == '\0') 2274 return "missing"; 2275 num = strtonum(nptr, 0, INT_MAX, &errstr); 2276 if (errstr == NULL) 2277 *val = (int)num; 2278 return errstr; 2279 } 2280 2281 int 2282 parse_absolute_time(const char *s, uint64_t *tp) 2283 { 2284 struct tm tm; 2285 time_t tt; 2286 char buf[32], *fmt; 2287 2288 *tp = 0; 2289 2290 /* 2291 * POSIX strptime says "The application shall ensure that there 2292 * is white-space or other non-alphanumeric characters between 2293 * any two conversion specifications" so arrange things this way. 2294 */ 2295 switch (strlen(s)) { 2296 case 8: /* YYYYMMDD */ 2297 fmt = "%Y-%m-%d"; 2298 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2299 break; 2300 case 12: /* YYYYMMDDHHMM */ 2301 fmt = "%Y-%m-%dT%H:%M"; 2302 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2303 s, s + 4, s + 6, s + 8, s + 10); 2304 break; 2305 case 14: /* YYYYMMDDHHMMSS */ 2306 fmt = "%Y-%m-%dT%H:%M:%S"; 2307 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2308 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2309 break; 2310 default: 2311 return SSH_ERR_INVALID_FORMAT; 2312 } 2313 2314 memset(&tm, 0, sizeof(tm)); 2315 if (strptime(buf, fmt, &tm) == NULL) 2316 return SSH_ERR_INVALID_FORMAT; 2317 if ((tt = mktime(&tm)) < 0) 2318 return SSH_ERR_INVALID_FORMAT; 2319 /* success */ 2320 *tp = (uint64_t)tt; 2321 return 0; 2322 } 2323 2324 /* On OpenBSD time_t is int64_t which is long long. */ 2325 #define SSH_TIME_T_MAX LLONG_MAX 2326 2327 void 2328 format_absolute_time(uint64_t t, char *buf, size_t len) 2329 { 2330 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2331 struct tm tm; 2332 2333 localtime_r(&tt, &tm); 2334 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2335 } 2336 2337 /* check if path is absolute */ 2338 int 2339 path_absolute(const char *path) 2340 { 2341 return (*path == '/') ? 1 : 0; 2342 } 2343 2344 void 2345 skip_space(char **cpp) 2346 { 2347 char *cp; 2348 2349 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2350 ; 2351 *cpp = cp; 2352 } 2353 2354 /* authorized_key-style options parsing helpers */ 2355 2356 /* 2357 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2358 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2359 * if negated option matches. 2360 * If the option or negated option matches, then *optsp is updated to 2361 * point to the first character after the option. 2362 */ 2363 int 2364 opt_flag(const char *opt, int allow_negate, const char **optsp) 2365 { 2366 size_t opt_len = strlen(opt); 2367 const char *opts = *optsp; 2368 int negate = 0; 2369 2370 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2371 opts += 3; 2372 negate = 1; 2373 } 2374 if (strncasecmp(opts, opt, opt_len) == 0) { 2375 *optsp = opts + opt_len; 2376 return negate ? 0 : 1; 2377 } 2378 return -1; 2379 } 2380 2381 char * 2382 opt_dequote(const char **sp, const char **errstrp) 2383 { 2384 const char *s = *sp; 2385 char *ret; 2386 size_t i; 2387 2388 *errstrp = NULL; 2389 if (*s != '"') { 2390 *errstrp = "missing start quote"; 2391 return NULL; 2392 } 2393 s++; 2394 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2395 *errstrp = "memory allocation failed"; 2396 return NULL; 2397 } 2398 for (i = 0; *s != '\0' && *s != '"';) { 2399 if (s[0] == '\\' && s[1] == '"') 2400 s++; 2401 ret[i++] = *s++; 2402 } 2403 if (*s == '\0') { 2404 *errstrp = "missing end quote"; 2405 free(ret); 2406 return NULL; 2407 } 2408 ret[i] = '\0'; 2409 s++; 2410 *sp = s; 2411 return ret; 2412 } 2413 2414 int 2415 opt_match(const char **opts, const char *term) 2416 { 2417 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2418 (*opts)[strlen(term)] == '=') { 2419 *opts += strlen(term) + 1; 2420 return 1; 2421 } 2422 return 0; 2423 } 2424 2425 void 2426 opt_array_append2(const char *file, const int line, const char *directive, 2427 char ***array, int **iarray, u_int *lp, const char *s, int i) 2428 { 2429 2430 if (*lp >= INT_MAX) 2431 fatal("%s line %d: Too many %s entries", file, line, directive); 2432 2433 if (iarray != NULL) { 2434 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2435 sizeof(**iarray)); 2436 (*iarray)[*lp] = i; 2437 } 2438 2439 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2440 (*array)[*lp] = xstrdup(s); 2441 (*lp)++; 2442 } 2443 2444 void 2445 opt_array_append(const char *file, const int line, const char *directive, 2446 char ***array, u_int *lp, const char *s) 2447 { 2448 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2449 } 2450 2451 sshsig_t 2452 ssh_signal(int signum, sshsig_t handler) 2453 { 2454 struct sigaction sa, osa; 2455 2456 /* mask all other signals while in handler */ 2457 memset(&sa, 0, sizeof(sa)); 2458 sa.sa_handler = handler; 2459 sigfillset(&sa.sa_mask); 2460 if (signum != SIGALRM) 2461 sa.sa_flags = SA_RESTART; 2462 if (sigaction(signum, &sa, &osa) == -1) { 2463 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2464 return SIG_ERR; 2465 } 2466 return osa.sa_handler; 2467 } 2468 2469 int 2470 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2471 { 2472 int devnull, ret = 0; 2473 2474 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2475 error_f("open %s: %s", _PATH_DEVNULL, 2476 strerror(errno)); 2477 return -1; 2478 } 2479 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2480 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2481 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2482 error_f("dup2: %s", strerror(errno)); 2483 ret = -1; 2484 } 2485 if (devnull > STDERR_FILENO) 2486 close(devnull); 2487 return ret; 2488 } 2489 2490 /* 2491 * Runs command in a subprocess with a minimal environment. 2492 * Returns pid on success, 0 on failure. 2493 * The child stdout and stderr maybe captured, left attached or sent to 2494 * /dev/null depending on the contents of flags. 2495 * "tag" is prepended to log messages. 2496 * NB. "command" is only used for logging; the actual command executed is 2497 * av[0]. 2498 */ 2499 pid_t 2500 subprocess(const char *tag, const char *command, 2501 int ac, char **av, FILE **child, u_int flags, 2502 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2503 { 2504 FILE *f = NULL; 2505 struct stat st; 2506 int fd, devnull, p[2], i; 2507 pid_t pid; 2508 char *cp, errmsg[512]; 2509 u_int nenv = 0; 2510 char **env = NULL; 2511 2512 /* If dropping privs, then must specify user and restore function */ 2513 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2514 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2515 return 0; 2516 } 2517 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2518 error("%s: no user for current uid", tag); 2519 return 0; 2520 } 2521 if (child != NULL) 2522 *child = NULL; 2523 2524 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2525 tag, command, pw->pw_name, flags); 2526 2527 /* Check consistency */ 2528 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2529 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2530 error_f("inconsistent flags"); 2531 return 0; 2532 } 2533 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2534 error_f("inconsistent flags/output"); 2535 return 0; 2536 } 2537 2538 /* 2539 * If executing an explicit binary, then verify the it exists 2540 * and appears safe-ish to execute 2541 */ 2542 if (!path_absolute(av[0])) { 2543 error("%s path is not absolute", tag); 2544 return 0; 2545 } 2546 if (drop_privs != NULL) 2547 drop_privs(pw); 2548 if (stat(av[0], &st) == -1) { 2549 error("Could not stat %s \"%s\": %s", tag, 2550 av[0], strerror(errno)); 2551 goto restore_return; 2552 } 2553 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2554 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2555 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2556 goto restore_return; 2557 } 2558 /* Prepare to keep the child's stdout if requested */ 2559 if (pipe(p) == -1) { 2560 error("%s: pipe: %s", tag, strerror(errno)); 2561 restore_return: 2562 if (restore_privs != NULL) 2563 restore_privs(); 2564 return 0; 2565 } 2566 if (restore_privs != NULL) 2567 restore_privs(); 2568 2569 switch ((pid = fork())) { 2570 case -1: /* error */ 2571 error("%s: fork: %s", tag, strerror(errno)); 2572 close(p[0]); 2573 close(p[1]); 2574 return 0; 2575 case 0: /* child */ 2576 /* Prepare a minimal environment for the child. */ 2577 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2578 nenv = 5; 2579 env = xcalloc(sizeof(*env), nenv); 2580 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2581 child_set_env(&env, &nenv, "USER", pw->pw_name); 2582 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2583 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2584 if ((cp = getenv("LANG")) != NULL) 2585 child_set_env(&env, &nenv, "LANG", cp); 2586 } 2587 2588 for (i = 1; i < NSIG; i++) 2589 ssh_signal(i, SIG_DFL); 2590 2591 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2592 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2593 strerror(errno)); 2594 _exit(1); 2595 } 2596 if (dup2(devnull, STDIN_FILENO) == -1) { 2597 error("%s: dup2: %s", tag, strerror(errno)); 2598 _exit(1); 2599 } 2600 2601 /* Set up stdout as requested; leave stderr in place for now. */ 2602 fd = -1; 2603 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2604 fd = p[1]; 2605 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2606 fd = devnull; 2607 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2608 error("%s: dup2: %s", tag, strerror(errno)); 2609 _exit(1); 2610 } 2611 closefrom(STDERR_FILENO + 1); 2612 2613 if (geteuid() == 0 && 2614 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2615 error("%s: initgroups(%s, %u): %s", tag, 2616 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2617 _exit(1); 2618 } 2619 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2620 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2621 strerror(errno)); 2622 _exit(1); 2623 } 2624 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2625 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2626 strerror(errno)); 2627 _exit(1); 2628 } 2629 /* stdin is pointed to /dev/null at this point */ 2630 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2631 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2632 error("%s: dup2: %s", tag, strerror(errno)); 2633 _exit(1); 2634 } 2635 if (env != NULL) 2636 execve(av[0], av, env); 2637 else 2638 execv(av[0], av); 2639 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2640 command, strerror(errno)); 2641 _exit(127); 2642 default: /* parent */ 2643 break; 2644 } 2645 2646 close(p[1]); 2647 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2648 close(p[0]); 2649 else if ((f = fdopen(p[0], "r")) == NULL) { 2650 error("%s: fdopen: %s", tag, strerror(errno)); 2651 close(p[0]); 2652 /* Don't leave zombie child */ 2653 kill(pid, SIGTERM); 2654 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2655 ; 2656 return 0; 2657 } 2658 /* Success */ 2659 debug3_f("%s pid %ld", tag, (long)pid); 2660 if (child != NULL) 2661 *child = f; 2662 return pid; 2663 } 2664 2665 const char * 2666 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2667 { 2668 size_t i, envlen; 2669 2670 envlen = strlen(env); 2671 for (i = 0; i < nenvs; i++) { 2672 if (strncmp(envs[i], env, envlen) == 0 && 2673 envs[i][envlen] == '=') { 2674 return envs[i] + envlen + 1; 2675 } 2676 } 2677 return NULL; 2678 } 2679