1 /* $OpenBSD: misc.c,v 1.168 2021/07/12 06:22:57 dtucker 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 char * 1073 tilde_expand_filename(const char *filename, uid_t uid) 1074 { 1075 const char *path, *sep; 1076 char user[128], *ret; 1077 struct passwd *pw; 1078 u_int len, slash; 1079 1080 if (*filename != '~') 1081 return (xstrdup(filename)); 1082 filename++; 1083 1084 path = strchr(filename, '/'); 1085 if (path != NULL && path > filename) { /* ~user/path */ 1086 slash = path - filename; 1087 if (slash > sizeof(user) - 1) 1088 fatal("tilde_expand_filename: ~username too long"); 1089 memcpy(user, filename, slash); 1090 user[slash] = '\0'; 1091 if ((pw = getpwnam(user)) == NULL) 1092 fatal("tilde_expand_filename: No such user %s", user); 1093 } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ 1094 fatal("tilde_expand_filename: No such uid %ld", (long)uid); 1095 1096 /* Make sure directory has a trailing '/' */ 1097 len = strlen(pw->pw_dir); 1098 if (len == 0 || pw->pw_dir[len - 1] != '/') 1099 sep = "/"; 1100 else 1101 sep = ""; 1102 1103 /* Skip leading '/' from specified path */ 1104 if (path != NULL) 1105 filename = path + 1; 1106 1107 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) 1108 fatal("tilde_expand_filename: Path too long"); 1109 1110 return (ret); 1111 } 1112 1113 /* 1114 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1115 * substitutions. A number of escapes may be specified as 1116 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1117 * by a NULL escape_char. Returns replaced string in memory allocated by 1118 * xmalloc which the caller must free. 1119 */ 1120 static char * 1121 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1122 const char *string, va_list ap) 1123 { 1124 #define EXPAND_MAX_KEYS 16 1125 u_int num_keys = 0, i; 1126 struct { 1127 const char *key; 1128 const char *repl; 1129 } keys[EXPAND_MAX_KEYS]; 1130 struct sshbuf *buf; 1131 int r, missingvar = 0; 1132 char *ret = NULL, *var, *varend, *val; 1133 size_t len; 1134 1135 if ((buf = sshbuf_new()) == NULL) 1136 fatal_f("sshbuf_new failed"); 1137 if (parseerror == NULL) 1138 fatal_f("null parseerror arg"); 1139 *parseerror = 1; 1140 1141 /* Gather keys if we're doing percent expansion. */ 1142 if (percent) { 1143 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1144 keys[num_keys].key = va_arg(ap, char *); 1145 if (keys[num_keys].key == NULL) 1146 break; 1147 keys[num_keys].repl = va_arg(ap, char *); 1148 if (keys[num_keys].repl == NULL) { 1149 fatal_f("NULL replacement for token %s", 1150 keys[num_keys].key); 1151 } 1152 } 1153 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1154 fatal_f("too many keys"); 1155 if (num_keys == 0) 1156 fatal_f("percent expansion without token list"); 1157 } 1158 1159 /* Expand string */ 1160 for (i = 0; *string != '\0'; string++) { 1161 /* Optionally process ${ENVIRONMENT} expansions. */ 1162 if (dollar && string[0] == '$' && string[1] == '{') { 1163 string += 2; /* skip over '${' */ 1164 if ((varend = strchr(string, '}')) == NULL) { 1165 error_f("environment variable '%s' missing " 1166 "closing '}'", string); 1167 goto out; 1168 } 1169 len = varend - string; 1170 if (len == 0) { 1171 error_f("zero-length environment variable"); 1172 goto out; 1173 } 1174 var = xmalloc(len + 1); 1175 (void)strlcpy(var, string, len + 1); 1176 if ((val = getenv(var)) == NULL) { 1177 error_f("env var ${%s} has no value", var); 1178 missingvar = 1; 1179 } else { 1180 debug3_f("expand ${%s} -> '%s'", var, val); 1181 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1182 fatal_fr(r, "sshbuf_put ${}"); 1183 } 1184 free(var); 1185 string += len; 1186 continue; 1187 } 1188 1189 /* 1190 * Process percent expansions if we have a list of TOKENs. 1191 * If we're not doing percent expansion everything just gets 1192 * appended here. 1193 */ 1194 if (*string != '%' || !percent) { 1195 append: 1196 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1197 fatal_fr(r, "sshbuf_put_u8 %%"); 1198 continue; 1199 } 1200 string++; 1201 /* %% case */ 1202 if (*string == '%') 1203 goto append; 1204 if (*string == '\0') { 1205 error_f("invalid format"); 1206 goto out; 1207 } 1208 for (i = 0; i < num_keys; i++) { 1209 if (strchr(keys[i].key, *string) != NULL) { 1210 if ((r = sshbuf_put(buf, keys[i].repl, 1211 strlen(keys[i].repl))) != 0) 1212 fatal_fr(r, "sshbuf_put %%-repl"); 1213 break; 1214 } 1215 } 1216 if (i >= num_keys) { 1217 error_f("unknown key %%%c", *string); 1218 goto out; 1219 } 1220 } 1221 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1222 fatal_f("sshbuf_dup_string failed"); 1223 *parseerror = 0; 1224 out: 1225 sshbuf_free(buf); 1226 return *parseerror ? NULL : ret; 1227 #undef EXPAND_MAX_KEYS 1228 } 1229 1230 /* 1231 * Expand only environment variables. 1232 * Note that although this function is variadic like the other similar 1233 * functions, any such arguments will be unused. 1234 */ 1235 1236 char * 1237 dollar_expand(int *parseerr, const char *string, ...) 1238 { 1239 char *ret; 1240 int err; 1241 va_list ap; 1242 1243 va_start(ap, string); 1244 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1245 va_end(ap); 1246 if (parseerr != NULL) 1247 *parseerr = err; 1248 return ret; 1249 } 1250 1251 /* 1252 * Returns expanded string or NULL if a specified environment variable is 1253 * not defined, or calls fatal if the string is invalid. 1254 */ 1255 char * 1256 percent_expand(const char *string, ...) 1257 { 1258 char *ret; 1259 int err; 1260 va_list ap; 1261 1262 va_start(ap, string); 1263 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1264 va_end(ap); 1265 if (err) 1266 fatal_f("failed"); 1267 return ret; 1268 } 1269 1270 /* 1271 * Returns expanded string or NULL if a specified environment variable is 1272 * not defined, or calls fatal if the string is invalid. 1273 */ 1274 char * 1275 percent_dollar_expand(const char *string, ...) 1276 { 1277 char *ret; 1278 int err; 1279 va_list ap; 1280 1281 va_start(ap, string); 1282 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1283 va_end(ap); 1284 if (err) 1285 fatal_f("failed"); 1286 return ret; 1287 } 1288 1289 int 1290 tun_open(int tun, int mode, char **ifname) 1291 { 1292 struct ifreq ifr; 1293 char name[100]; 1294 int fd = -1, sock; 1295 const char *tunbase = "tun"; 1296 1297 if (ifname != NULL) 1298 *ifname = NULL; 1299 1300 if (mode == SSH_TUNMODE_ETHERNET) 1301 tunbase = "tap"; 1302 1303 /* Open the tunnel device */ 1304 if (tun <= SSH_TUNID_MAX) { 1305 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1306 fd = open(name, O_RDWR); 1307 } else if (tun == SSH_TUNID_ANY) { 1308 for (tun = 100; tun >= 0; tun--) { 1309 snprintf(name, sizeof(name), "/dev/%s%d", 1310 tunbase, tun); 1311 if ((fd = open(name, O_RDWR)) >= 0) 1312 break; 1313 } 1314 } else { 1315 debug_f("invalid tunnel %u", tun); 1316 return -1; 1317 } 1318 1319 if (fd == -1) { 1320 debug_f("%s open: %s", name, strerror(errno)); 1321 return -1; 1322 } 1323 1324 debug_f("%s mode %d fd %d", name, mode, fd); 1325 1326 /* Bring interface up if it is not already */ 1327 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1328 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1329 goto failed; 1330 1331 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1332 debug_f("get interface %s flags: %s", ifr.ifr_name, 1333 strerror(errno)); 1334 goto failed; 1335 } 1336 1337 if (!(ifr.ifr_flags & IFF_UP)) { 1338 ifr.ifr_flags |= IFF_UP; 1339 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1340 debug_f("activate interface %s: %s", ifr.ifr_name, 1341 strerror(errno)); 1342 goto failed; 1343 } 1344 } 1345 1346 if (ifname != NULL) 1347 *ifname = xstrdup(ifr.ifr_name); 1348 1349 close(sock); 1350 return fd; 1351 1352 failed: 1353 if (fd >= 0) 1354 close(fd); 1355 if (sock >= 0) 1356 close(sock); 1357 return -1; 1358 } 1359 1360 void 1361 sanitise_stdfd(void) 1362 { 1363 int nullfd, dupfd; 1364 1365 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1366 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1367 strerror(errno)); 1368 exit(1); 1369 } 1370 while (++dupfd <= STDERR_FILENO) { 1371 /* Only populate closed fds. */ 1372 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1373 if (dup2(nullfd, dupfd) == -1) { 1374 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1375 exit(1); 1376 } 1377 } 1378 } 1379 if (nullfd > STDERR_FILENO) 1380 close(nullfd); 1381 } 1382 1383 char * 1384 tohex(const void *vp, size_t l) 1385 { 1386 const u_char *p = (const u_char *)vp; 1387 char b[3], *r; 1388 size_t i, hl; 1389 1390 if (l > 65536) 1391 return xstrdup("tohex: length > 65536"); 1392 1393 hl = l * 2 + 1; 1394 r = xcalloc(1, hl); 1395 for (i = 0; i < l; i++) { 1396 snprintf(b, sizeof(b), "%02x", p[i]); 1397 strlcat(r, b, hl); 1398 } 1399 return (r); 1400 } 1401 1402 /* 1403 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1404 * then the separator 'sep' will be prepended before the formatted arguments. 1405 * Extended strings are heap allocated. 1406 */ 1407 void 1408 xextendf(char **sp, const char *sep, const char *fmt, ...) 1409 { 1410 va_list ap; 1411 char *tmp1, *tmp2; 1412 1413 va_start(ap, fmt); 1414 xvasprintf(&tmp1, fmt, ap); 1415 va_end(ap); 1416 1417 if (*sp == NULL || **sp == '\0') { 1418 free(*sp); 1419 *sp = tmp1; 1420 return; 1421 } 1422 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1423 free(tmp1); 1424 free(*sp); 1425 *sp = tmp2; 1426 } 1427 1428 1429 u_int64_t 1430 get_u64(const void *vp) 1431 { 1432 const u_char *p = (const u_char *)vp; 1433 u_int64_t v; 1434 1435 v = (u_int64_t)p[0] << 56; 1436 v |= (u_int64_t)p[1] << 48; 1437 v |= (u_int64_t)p[2] << 40; 1438 v |= (u_int64_t)p[3] << 32; 1439 v |= (u_int64_t)p[4] << 24; 1440 v |= (u_int64_t)p[5] << 16; 1441 v |= (u_int64_t)p[6] << 8; 1442 v |= (u_int64_t)p[7]; 1443 1444 return (v); 1445 } 1446 1447 u_int32_t 1448 get_u32(const void *vp) 1449 { 1450 const u_char *p = (const u_char *)vp; 1451 u_int32_t v; 1452 1453 v = (u_int32_t)p[0] << 24; 1454 v |= (u_int32_t)p[1] << 16; 1455 v |= (u_int32_t)p[2] << 8; 1456 v |= (u_int32_t)p[3]; 1457 1458 return (v); 1459 } 1460 1461 u_int32_t 1462 get_u32_le(const void *vp) 1463 { 1464 const u_char *p = (const u_char *)vp; 1465 u_int32_t v; 1466 1467 v = (u_int32_t)p[0]; 1468 v |= (u_int32_t)p[1] << 8; 1469 v |= (u_int32_t)p[2] << 16; 1470 v |= (u_int32_t)p[3] << 24; 1471 1472 return (v); 1473 } 1474 1475 u_int16_t 1476 get_u16(const void *vp) 1477 { 1478 const u_char *p = (const u_char *)vp; 1479 u_int16_t v; 1480 1481 v = (u_int16_t)p[0] << 8; 1482 v |= (u_int16_t)p[1]; 1483 1484 return (v); 1485 } 1486 1487 void 1488 put_u64(void *vp, u_int64_t v) 1489 { 1490 u_char *p = (u_char *)vp; 1491 1492 p[0] = (u_char)(v >> 56) & 0xff; 1493 p[1] = (u_char)(v >> 48) & 0xff; 1494 p[2] = (u_char)(v >> 40) & 0xff; 1495 p[3] = (u_char)(v >> 32) & 0xff; 1496 p[4] = (u_char)(v >> 24) & 0xff; 1497 p[5] = (u_char)(v >> 16) & 0xff; 1498 p[6] = (u_char)(v >> 8) & 0xff; 1499 p[7] = (u_char)v & 0xff; 1500 } 1501 1502 void 1503 put_u32(void *vp, u_int32_t v) 1504 { 1505 u_char *p = (u_char *)vp; 1506 1507 p[0] = (u_char)(v >> 24) & 0xff; 1508 p[1] = (u_char)(v >> 16) & 0xff; 1509 p[2] = (u_char)(v >> 8) & 0xff; 1510 p[3] = (u_char)v & 0xff; 1511 } 1512 1513 void 1514 put_u32_le(void *vp, u_int32_t v) 1515 { 1516 u_char *p = (u_char *)vp; 1517 1518 p[0] = (u_char)v & 0xff; 1519 p[1] = (u_char)(v >> 8) & 0xff; 1520 p[2] = (u_char)(v >> 16) & 0xff; 1521 p[3] = (u_char)(v >> 24) & 0xff; 1522 } 1523 1524 void 1525 put_u16(void *vp, u_int16_t v) 1526 { 1527 u_char *p = (u_char *)vp; 1528 1529 p[0] = (u_char)(v >> 8) & 0xff; 1530 p[1] = (u_char)v & 0xff; 1531 } 1532 1533 void 1534 ms_subtract_diff(struct timeval *start, int *ms) 1535 { 1536 struct timeval diff, finish; 1537 1538 monotime_tv(&finish); 1539 timersub(&finish, start, &diff); 1540 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1541 } 1542 1543 void 1544 ms_to_timeval(struct timeval *tv, int ms) 1545 { 1546 if (ms < 0) 1547 ms = 0; 1548 tv->tv_sec = ms / 1000; 1549 tv->tv_usec = (ms % 1000) * 1000; 1550 } 1551 1552 void 1553 monotime_ts(struct timespec *ts) 1554 { 1555 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1556 fatal("clock_gettime: %s", strerror(errno)); 1557 } 1558 1559 void 1560 monotime_tv(struct timeval *tv) 1561 { 1562 struct timespec ts; 1563 1564 monotime_ts(&ts); 1565 tv->tv_sec = ts.tv_sec; 1566 tv->tv_usec = ts.tv_nsec / 1000; 1567 } 1568 1569 time_t 1570 monotime(void) 1571 { 1572 struct timespec ts; 1573 1574 monotime_ts(&ts); 1575 return (ts.tv_sec); 1576 } 1577 1578 double 1579 monotime_double(void) 1580 { 1581 struct timespec ts; 1582 1583 monotime_ts(&ts); 1584 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1585 } 1586 1587 void 1588 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1589 { 1590 bw->buflen = buflen; 1591 bw->rate = kbps; 1592 bw->thresh = buflen; 1593 bw->lamt = 0; 1594 timerclear(&bw->bwstart); 1595 timerclear(&bw->bwend); 1596 } 1597 1598 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1599 void 1600 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1601 { 1602 u_int64_t waitlen; 1603 struct timespec ts, rm; 1604 1605 bw->lamt += read_len; 1606 if (!timerisset(&bw->bwstart)) { 1607 monotime_tv(&bw->bwstart); 1608 return; 1609 } 1610 if (bw->lamt < bw->thresh) 1611 return; 1612 1613 monotime_tv(&bw->bwend); 1614 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1615 if (!timerisset(&bw->bwend)) 1616 return; 1617 1618 bw->lamt *= 8; 1619 waitlen = (double)1000000L * bw->lamt / bw->rate; 1620 1621 bw->bwstart.tv_sec = waitlen / 1000000L; 1622 bw->bwstart.tv_usec = waitlen % 1000000L; 1623 1624 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1625 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1626 1627 /* Adjust the wait time */ 1628 if (bw->bwend.tv_sec) { 1629 bw->thresh /= 2; 1630 if (bw->thresh < bw->buflen / 4) 1631 bw->thresh = bw->buflen / 4; 1632 } else if (bw->bwend.tv_usec < 10000) { 1633 bw->thresh *= 2; 1634 if (bw->thresh > bw->buflen * 8) 1635 bw->thresh = bw->buflen * 8; 1636 } 1637 1638 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1639 while (nanosleep(&ts, &rm) == -1) { 1640 if (errno != EINTR) 1641 break; 1642 ts = rm; 1643 } 1644 } 1645 1646 bw->lamt = 0; 1647 monotime_tv(&bw->bwstart); 1648 } 1649 1650 /* Make a template filename for mk[sd]temp() */ 1651 void 1652 mktemp_proto(char *s, size_t len) 1653 { 1654 const char *tmpdir; 1655 int r; 1656 1657 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1658 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1659 if (r > 0 && (size_t)r < len) 1660 return; 1661 } 1662 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1663 if (r < 0 || (size_t)r >= len) 1664 fatal_f("template string too short"); 1665 } 1666 1667 static const struct { 1668 const char *name; 1669 int value; 1670 } ipqos[] = { 1671 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1672 { "af11", IPTOS_DSCP_AF11 }, 1673 { "af12", IPTOS_DSCP_AF12 }, 1674 { "af13", IPTOS_DSCP_AF13 }, 1675 { "af21", IPTOS_DSCP_AF21 }, 1676 { "af22", IPTOS_DSCP_AF22 }, 1677 { "af23", IPTOS_DSCP_AF23 }, 1678 { "af31", IPTOS_DSCP_AF31 }, 1679 { "af32", IPTOS_DSCP_AF32 }, 1680 { "af33", IPTOS_DSCP_AF33 }, 1681 { "af41", IPTOS_DSCP_AF41 }, 1682 { "af42", IPTOS_DSCP_AF42 }, 1683 { "af43", IPTOS_DSCP_AF43 }, 1684 { "cs0", IPTOS_DSCP_CS0 }, 1685 { "cs1", IPTOS_DSCP_CS1 }, 1686 { "cs2", IPTOS_DSCP_CS2 }, 1687 { "cs3", IPTOS_DSCP_CS3 }, 1688 { "cs4", IPTOS_DSCP_CS4 }, 1689 { "cs5", IPTOS_DSCP_CS5 }, 1690 { "cs6", IPTOS_DSCP_CS6 }, 1691 { "cs7", IPTOS_DSCP_CS7 }, 1692 { "ef", IPTOS_DSCP_EF }, 1693 { "le", IPTOS_DSCP_LE }, 1694 { "lowdelay", IPTOS_LOWDELAY }, 1695 { "throughput", IPTOS_THROUGHPUT }, 1696 { "reliability", IPTOS_RELIABILITY }, 1697 { NULL, -1 } 1698 }; 1699 1700 int 1701 parse_ipqos(const char *cp) 1702 { 1703 u_int i; 1704 char *ep; 1705 long val; 1706 1707 if (cp == NULL) 1708 return -1; 1709 for (i = 0; ipqos[i].name != NULL; i++) { 1710 if (strcasecmp(cp, ipqos[i].name) == 0) 1711 return ipqos[i].value; 1712 } 1713 /* Try parsing as an integer */ 1714 val = strtol(cp, &ep, 0); 1715 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1716 return -1; 1717 return val; 1718 } 1719 1720 const char * 1721 iptos2str(int iptos) 1722 { 1723 int i; 1724 static char iptos_str[sizeof "0xff"]; 1725 1726 for (i = 0; ipqos[i].name != NULL; i++) { 1727 if (ipqos[i].value == iptos) 1728 return ipqos[i].name; 1729 } 1730 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1731 return iptos_str; 1732 } 1733 1734 void 1735 lowercase(char *s) 1736 { 1737 for (; *s; s++) 1738 *s = tolower((u_char)*s); 1739 } 1740 1741 int 1742 unix_listener(const char *path, int backlog, int unlink_first) 1743 { 1744 struct sockaddr_un sunaddr; 1745 int saved_errno, sock; 1746 1747 memset(&sunaddr, 0, sizeof(sunaddr)); 1748 sunaddr.sun_family = AF_UNIX; 1749 if (strlcpy(sunaddr.sun_path, path, 1750 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1751 error_f("path \"%s\" too long for Unix domain socket", path); 1752 errno = ENAMETOOLONG; 1753 return -1; 1754 } 1755 1756 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1757 if (sock == -1) { 1758 saved_errno = errno; 1759 error_f("socket: %.100s", strerror(errno)); 1760 errno = saved_errno; 1761 return -1; 1762 } 1763 if (unlink_first == 1) { 1764 if (unlink(path) != 0 && errno != ENOENT) 1765 error("unlink(%s): %.100s", path, strerror(errno)); 1766 } 1767 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1768 saved_errno = errno; 1769 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1770 close(sock); 1771 errno = saved_errno; 1772 return -1; 1773 } 1774 if (listen(sock, backlog) == -1) { 1775 saved_errno = errno; 1776 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1777 close(sock); 1778 unlink(path); 1779 errno = saved_errno; 1780 return -1; 1781 } 1782 return sock; 1783 } 1784 1785 /* 1786 * Compares two strings that maybe be NULL. Returns non-zero if strings 1787 * are both NULL or are identical, returns zero otherwise. 1788 */ 1789 static int 1790 strcmp_maybe_null(const char *a, const char *b) 1791 { 1792 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1793 return 0; 1794 if (a != NULL && strcmp(a, b) != 0) 1795 return 0; 1796 return 1; 1797 } 1798 1799 /* 1800 * Compare two forwards, returning non-zero if they are identical or 1801 * zero otherwise. 1802 */ 1803 int 1804 forward_equals(const struct Forward *a, const struct Forward *b) 1805 { 1806 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1807 return 0; 1808 if (a->listen_port != b->listen_port) 1809 return 0; 1810 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1811 return 0; 1812 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1813 return 0; 1814 if (a->connect_port != b->connect_port) 1815 return 0; 1816 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1817 return 0; 1818 /* allocated_port and handle are not checked */ 1819 return 1; 1820 } 1821 1822 /* returns 1 if process is already daemonized, 0 otherwise */ 1823 int 1824 daemonized(void) 1825 { 1826 int fd; 1827 1828 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1829 close(fd); 1830 return 0; /* have controlling terminal */ 1831 } 1832 if (getppid() != 1) 1833 return 0; /* parent is not init */ 1834 if (getsid(0) != getpid()) 1835 return 0; /* not session leader */ 1836 debug3("already daemonized"); 1837 return 1; 1838 } 1839 1840 /* 1841 * Splits 's' into an argument vector. Handles quoted string and basic 1842 * escape characters (\\, \", \'). Caller must free the argument vector 1843 * and its members. 1844 */ 1845 int 1846 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1847 { 1848 int r = SSH_ERR_INTERNAL_ERROR; 1849 int argc = 0, quote, i, j; 1850 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1851 1852 *argvp = NULL; 1853 *argcp = 0; 1854 1855 for (i = 0; s[i] != '\0'; i++) { 1856 /* Skip leading whitespace */ 1857 if (s[i] == ' ' || s[i] == '\t') 1858 continue; 1859 if (terminate_on_comment && s[i] == '#') 1860 break; 1861 /* Start of a token */ 1862 quote = 0; 1863 1864 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1865 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1866 argv[argc] = NULL; 1867 1868 /* Copy the token in, removing escapes */ 1869 for (j = 0; s[i] != '\0'; i++) { 1870 if (s[i] == '\\') { 1871 if (s[i + 1] == '\'' || 1872 s[i + 1] == '\"' || 1873 s[i + 1] == '\\' || 1874 (quote == 0 && s[i + 1] == ' ')) { 1875 i++; /* Skip '\' */ 1876 arg[j++] = s[i]; 1877 } else { 1878 /* Unrecognised escape */ 1879 arg[j++] = s[i]; 1880 } 1881 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1882 break; /* done */ 1883 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1884 quote = s[i]; /* quote start */ 1885 else if (quote != 0 && s[i] == quote) 1886 quote = 0; /* quote end */ 1887 else 1888 arg[j++] = s[i]; 1889 } 1890 if (s[i] == '\0') { 1891 if (quote != 0) { 1892 /* Ran out of string looking for close quote */ 1893 r = SSH_ERR_INVALID_FORMAT; 1894 goto out; 1895 } 1896 break; 1897 } 1898 } 1899 /* Success */ 1900 *argcp = argc; 1901 *argvp = argv; 1902 argc = 0; 1903 argv = NULL; 1904 r = 0; 1905 out: 1906 if (argc != 0 && argv != NULL) { 1907 for (i = 0; i < argc; i++) 1908 free(argv[i]); 1909 free(argv); 1910 } 1911 return r; 1912 } 1913 1914 /* 1915 * Reassemble an argument vector into a string, quoting and escaping as 1916 * necessary. Caller must free returned string. 1917 */ 1918 char * 1919 argv_assemble(int argc, char **argv) 1920 { 1921 int i, j, ws, r; 1922 char c, *ret; 1923 struct sshbuf *buf, *arg; 1924 1925 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1926 fatal_f("sshbuf_new failed"); 1927 1928 for (i = 0; i < argc; i++) { 1929 ws = 0; 1930 sshbuf_reset(arg); 1931 for (j = 0; argv[i][j] != '\0'; j++) { 1932 r = 0; 1933 c = argv[i][j]; 1934 switch (c) { 1935 case ' ': 1936 case '\t': 1937 ws = 1; 1938 r = sshbuf_put_u8(arg, c); 1939 break; 1940 case '\\': 1941 case '\'': 1942 case '"': 1943 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 1944 break; 1945 /* FALLTHROUGH */ 1946 default: 1947 r = sshbuf_put_u8(arg, c); 1948 break; 1949 } 1950 if (r != 0) 1951 fatal_fr(r, "sshbuf_put_u8"); 1952 } 1953 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 1954 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 1955 (r = sshbuf_putb(buf, arg)) != 0 || 1956 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 1957 fatal_fr(r, "assemble"); 1958 } 1959 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 1960 fatal_f("malloc failed"); 1961 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 1962 ret[sshbuf_len(buf)] = '\0'; 1963 sshbuf_free(buf); 1964 sshbuf_free(arg); 1965 return ret; 1966 } 1967 1968 char * 1969 argv_next(int *argcp, char ***argvp) 1970 { 1971 char *ret = (*argvp)[0]; 1972 1973 if (*argcp > 0 && ret != NULL) { 1974 (*argcp)--; 1975 (*argvp)++; 1976 } 1977 return ret; 1978 } 1979 1980 void 1981 argv_consume(int *argcp) 1982 { 1983 *argcp = 0; 1984 } 1985 1986 void 1987 argv_free(char **av, int ac) 1988 { 1989 int i; 1990 1991 if (av == NULL) 1992 return; 1993 for (i = 0; i < ac; i++) 1994 free(av[i]); 1995 free(av); 1996 } 1997 1998 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 1999 int 2000 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2001 { 2002 int status; 2003 2004 while (waitpid(pid, &status, 0) == -1) { 2005 if (errno != EINTR) { 2006 error("%s waitpid: %s", tag, strerror(errno)); 2007 return -1; 2008 } 2009 } 2010 if (WIFSIGNALED(status)) { 2011 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2012 return -1; 2013 } else if (WEXITSTATUS(status) != 0) { 2014 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2015 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2016 return -1; 2017 } 2018 return 0; 2019 } 2020 2021 /* 2022 * Check a given path for security. This is defined as all components 2023 * of the path to the file must be owned by either the owner of 2024 * of the file or root and no directories must be group or world writable. 2025 * 2026 * XXX Should any specific check be done for sym links ? 2027 * 2028 * Takes a file name, its stat information (preferably from fstat() to 2029 * avoid races), the uid of the expected owner, their home directory and an 2030 * error buffer plus max size as arguments. 2031 * 2032 * Returns 0 on success and -1 on failure 2033 */ 2034 int 2035 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2036 uid_t uid, char *err, size_t errlen) 2037 { 2038 char buf[PATH_MAX], homedir[PATH_MAX]; 2039 char *cp; 2040 int comparehome = 0; 2041 struct stat st; 2042 2043 if (realpath(name, buf) == NULL) { 2044 snprintf(err, errlen, "realpath %s failed: %s", name, 2045 strerror(errno)); 2046 return -1; 2047 } 2048 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2049 comparehome = 1; 2050 2051 if (!S_ISREG(stp->st_mode)) { 2052 snprintf(err, errlen, "%s is not a regular file", buf); 2053 return -1; 2054 } 2055 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2056 (stp->st_mode & 022) != 0) { 2057 snprintf(err, errlen, "bad ownership or modes for file %s", 2058 buf); 2059 return -1; 2060 } 2061 2062 /* for each component of the canonical path, walking upwards */ 2063 for (;;) { 2064 if ((cp = dirname(buf)) == NULL) { 2065 snprintf(err, errlen, "dirname() failed"); 2066 return -1; 2067 } 2068 strlcpy(buf, cp, sizeof(buf)); 2069 2070 if (stat(buf, &st) == -1 || 2071 (st.st_uid != 0 && st.st_uid != uid) || 2072 (st.st_mode & 022) != 0) { 2073 snprintf(err, errlen, 2074 "bad ownership or modes for directory %s", buf); 2075 return -1; 2076 } 2077 2078 /* If are past the homedir then we can stop */ 2079 if (comparehome && strcmp(homedir, buf) == 0) 2080 break; 2081 2082 /* 2083 * dirname should always complete with a "/" path, 2084 * but we can be paranoid and check for "." too 2085 */ 2086 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2087 break; 2088 } 2089 return 0; 2090 } 2091 2092 /* 2093 * Version of safe_path() that accepts an open file descriptor to 2094 * avoid races. 2095 * 2096 * Returns 0 on success and -1 on failure 2097 */ 2098 int 2099 safe_path_fd(int fd, const char *file, struct passwd *pw, 2100 char *err, size_t errlen) 2101 { 2102 struct stat st; 2103 2104 /* check the open file to avoid races */ 2105 if (fstat(fd, &st) == -1) { 2106 snprintf(err, errlen, "cannot stat file %s: %s", 2107 file, strerror(errno)); 2108 return -1; 2109 } 2110 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2111 } 2112 2113 /* 2114 * Sets the value of the given variable in the environment. If the variable 2115 * already exists, its value is overridden. 2116 */ 2117 void 2118 child_set_env(char ***envp, u_int *envsizep, const char *name, 2119 const char *value) 2120 { 2121 char **env; 2122 u_int envsize; 2123 u_int i, namelen; 2124 2125 if (strchr(name, '=') != NULL) { 2126 error("Invalid environment variable \"%.100s\"", name); 2127 return; 2128 } 2129 2130 /* 2131 * Find the slot where the value should be stored. If the variable 2132 * already exists, we reuse the slot; otherwise we append a new slot 2133 * at the end of the array, expanding if necessary. 2134 */ 2135 env = *envp; 2136 namelen = strlen(name); 2137 for (i = 0; env[i]; i++) 2138 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2139 break; 2140 if (env[i]) { 2141 /* Reuse the slot. */ 2142 free(env[i]); 2143 } else { 2144 /* New variable. Expand if necessary. */ 2145 envsize = *envsizep; 2146 if (i >= envsize - 1) { 2147 if (envsize >= 1000) 2148 fatal("child_set_env: too many env vars"); 2149 envsize += 50; 2150 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2151 *envsizep = envsize; 2152 } 2153 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2154 env[i + 1] = NULL; 2155 } 2156 2157 /* Allocate space and format the variable in the appropriate slot. */ 2158 /* XXX xasprintf */ 2159 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2160 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2161 } 2162 2163 /* 2164 * Check and optionally lowercase a domain name, also removes trailing '.' 2165 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2166 */ 2167 int 2168 valid_domain(char *name, int makelower, const char **errstr) 2169 { 2170 size_t i, l = strlen(name); 2171 u_char c, last = '\0'; 2172 static char errbuf[256]; 2173 2174 if (l == 0) { 2175 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2176 goto bad; 2177 } 2178 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2179 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2180 "starts with invalid character", name); 2181 goto bad; 2182 } 2183 for (i = 0; i < l; i++) { 2184 c = tolower((u_char)name[i]); 2185 if (makelower) 2186 name[i] = (char)c; 2187 if (last == '.' && c == '.') { 2188 snprintf(errbuf, sizeof(errbuf), "domain name " 2189 "\"%.100s\" contains consecutive separators", name); 2190 goto bad; 2191 } 2192 if (c != '.' && c != '-' && !isalnum(c) && 2193 c != '_') /* technically invalid, but common */ { 2194 snprintf(errbuf, sizeof(errbuf), "domain name " 2195 "\"%.100s\" contains invalid characters", name); 2196 goto bad; 2197 } 2198 last = c; 2199 } 2200 if (name[l - 1] == '.') 2201 name[l - 1] = '\0'; 2202 if (errstr != NULL) 2203 *errstr = NULL; 2204 return 1; 2205 bad: 2206 if (errstr != NULL) 2207 *errstr = errbuf; 2208 return 0; 2209 } 2210 2211 /* 2212 * Verify that a environment variable name (not including initial '$') is 2213 * valid; consisting of one or more alphanumeric or underscore characters only. 2214 * Returns 1 on valid, 0 otherwise. 2215 */ 2216 int 2217 valid_env_name(const char *name) 2218 { 2219 const char *cp; 2220 2221 if (name[0] == '\0') 2222 return 0; 2223 for (cp = name; *cp != '\0'; cp++) { 2224 if (!isalnum((u_char)*cp) && *cp != '_') 2225 return 0; 2226 } 2227 return 1; 2228 } 2229 2230 const char * 2231 atoi_err(const char *nptr, int *val) 2232 { 2233 const char *errstr = NULL; 2234 long long num; 2235 2236 if (nptr == NULL || *nptr == '\0') 2237 return "missing"; 2238 num = strtonum(nptr, 0, INT_MAX, &errstr); 2239 if (errstr == NULL) 2240 *val = (int)num; 2241 return errstr; 2242 } 2243 2244 int 2245 parse_absolute_time(const char *s, uint64_t *tp) 2246 { 2247 struct tm tm; 2248 time_t tt; 2249 char buf[32], *fmt; 2250 2251 *tp = 0; 2252 2253 /* 2254 * POSIX strptime says "The application shall ensure that there 2255 * is white-space or other non-alphanumeric characters between 2256 * any two conversion specifications" so arrange things this way. 2257 */ 2258 switch (strlen(s)) { 2259 case 8: /* YYYYMMDD */ 2260 fmt = "%Y-%m-%d"; 2261 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2262 break; 2263 case 12: /* YYYYMMDDHHMM */ 2264 fmt = "%Y-%m-%dT%H:%M"; 2265 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2266 s, s + 4, s + 6, s + 8, s + 10); 2267 break; 2268 case 14: /* YYYYMMDDHHMMSS */ 2269 fmt = "%Y-%m-%dT%H:%M:%S"; 2270 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2271 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2272 break; 2273 default: 2274 return SSH_ERR_INVALID_FORMAT; 2275 } 2276 2277 memset(&tm, 0, sizeof(tm)); 2278 if (strptime(buf, fmt, &tm) == NULL) 2279 return SSH_ERR_INVALID_FORMAT; 2280 if ((tt = mktime(&tm)) < 0) 2281 return SSH_ERR_INVALID_FORMAT; 2282 /* success */ 2283 *tp = (uint64_t)tt; 2284 return 0; 2285 } 2286 2287 /* On OpenBSD time_t is int64_t which is long long. */ 2288 #define SSH_TIME_T_MAX LLONG_MAX 2289 2290 void 2291 format_absolute_time(uint64_t t, char *buf, size_t len) 2292 { 2293 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2294 struct tm tm; 2295 2296 localtime_r(&tt, &tm); 2297 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2298 } 2299 2300 /* check if path is absolute */ 2301 int 2302 path_absolute(const char *path) 2303 { 2304 return (*path == '/') ? 1 : 0; 2305 } 2306 2307 void 2308 skip_space(char **cpp) 2309 { 2310 char *cp; 2311 2312 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2313 ; 2314 *cpp = cp; 2315 } 2316 2317 /* authorized_key-style options parsing helpers */ 2318 2319 /* 2320 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2321 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2322 * if negated option matches. 2323 * If the option or negated option matches, then *optsp is updated to 2324 * point to the first character after the option. 2325 */ 2326 int 2327 opt_flag(const char *opt, int allow_negate, const char **optsp) 2328 { 2329 size_t opt_len = strlen(opt); 2330 const char *opts = *optsp; 2331 int negate = 0; 2332 2333 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2334 opts += 3; 2335 negate = 1; 2336 } 2337 if (strncasecmp(opts, opt, opt_len) == 0) { 2338 *optsp = opts + opt_len; 2339 return negate ? 0 : 1; 2340 } 2341 return -1; 2342 } 2343 2344 char * 2345 opt_dequote(const char **sp, const char **errstrp) 2346 { 2347 const char *s = *sp; 2348 char *ret; 2349 size_t i; 2350 2351 *errstrp = NULL; 2352 if (*s != '"') { 2353 *errstrp = "missing start quote"; 2354 return NULL; 2355 } 2356 s++; 2357 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2358 *errstrp = "memory allocation failed"; 2359 return NULL; 2360 } 2361 for (i = 0; *s != '\0' && *s != '"';) { 2362 if (s[0] == '\\' && s[1] == '"') 2363 s++; 2364 ret[i++] = *s++; 2365 } 2366 if (*s == '\0') { 2367 *errstrp = "missing end quote"; 2368 free(ret); 2369 return NULL; 2370 } 2371 ret[i] = '\0'; 2372 s++; 2373 *sp = s; 2374 return ret; 2375 } 2376 2377 int 2378 opt_match(const char **opts, const char *term) 2379 { 2380 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2381 (*opts)[strlen(term)] == '=') { 2382 *opts += strlen(term) + 1; 2383 return 1; 2384 } 2385 return 0; 2386 } 2387 2388 void 2389 opt_array_append2(const char *file, const int line, const char *directive, 2390 char ***array, int **iarray, u_int *lp, const char *s, int i) 2391 { 2392 2393 if (*lp >= INT_MAX) 2394 fatal("%s line %d: Too many %s entries", file, line, directive); 2395 2396 if (iarray != NULL) { 2397 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2398 sizeof(**iarray)); 2399 (*iarray)[*lp] = i; 2400 } 2401 2402 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2403 (*array)[*lp] = xstrdup(s); 2404 (*lp)++; 2405 } 2406 2407 void 2408 opt_array_append(const char *file, const int line, const char *directive, 2409 char ***array, u_int *lp, const char *s) 2410 { 2411 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2412 } 2413 2414 sshsig_t 2415 ssh_signal(int signum, sshsig_t handler) 2416 { 2417 struct sigaction sa, osa; 2418 2419 /* mask all other signals while in handler */ 2420 memset(&sa, 0, sizeof(sa)); 2421 sa.sa_handler = handler; 2422 sigfillset(&sa.sa_mask); 2423 if (signum != SIGALRM) 2424 sa.sa_flags = SA_RESTART; 2425 if (sigaction(signum, &sa, &osa) == -1) { 2426 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2427 return SIG_ERR; 2428 } 2429 return osa.sa_handler; 2430 } 2431 2432 int 2433 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2434 { 2435 int devnull, ret = 0; 2436 2437 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2438 error_f("open %s: %s", _PATH_DEVNULL, 2439 strerror(errno)); 2440 return -1; 2441 } 2442 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2443 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2444 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2445 error_f("dup2: %s", strerror(errno)); 2446 ret = -1; 2447 } 2448 if (devnull > STDERR_FILENO) 2449 close(devnull); 2450 return ret; 2451 } 2452 2453 /* 2454 * Runs command in a subprocess with a minimal environment. 2455 * Returns pid on success, 0 on failure. 2456 * The child stdout and stderr maybe captured, left attached or sent to 2457 * /dev/null depending on the contents of flags. 2458 * "tag" is prepended to log messages. 2459 * NB. "command" is only used for logging; the actual command executed is 2460 * av[0]. 2461 */ 2462 pid_t 2463 subprocess(const char *tag, const char *command, 2464 int ac, char **av, FILE **child, u_int flags, 2465 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2466 { 2467 FILE *f = NULL; 2468 struct stat st; 2469 int fd, devnull, p[2], i; 2470 pid_t pid; 2471 char *cp, errmsg[512]; 2472 u_int nenv = 0; 2473 char **env = NULL; 2474 2475 /* If dropping privs, then must specify user and restore function */ 2476 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2477 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2478 return 0; 2479 } 2480 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2481 error("%s: no user for current uid", tag); 2482 return 0; 2483 } 2484 if (child != NULL) 2485 *child = NULL; 2486 2487 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2488 tag, command, pw->pw_name, flags); 2489 2490 /* Check consistency */ 2491 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2492 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2493 error_f("inconsistent flags"); 2494 return 0; 2495 } 2496 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2497 error_f("inconsistent flags/output"); 2498 return 0; 2499 } 2500 2501 /* 2502 * If executing an explicit binary, then verify the it exists 2503 * and appears safe-ish to execute 2504 */ 2505 if (!path_absolute(av[0])) { 2506 error("%s path is not absolute", tag); 2507 return 0; 2508 } 2509 if (drop_privs != NULL) 2510 drop_privs(pw); 2511 if (stat(av[0], &st) == -1) { 2512 error("Could not stat %s \"%s\": %s", tag, 2513 av[0], strerror(errno)); 2514 goto restore_return; 2515 } 2516 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2517 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2518 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2519 goto restore_return; 2520 } 2521 /* Prepare to keep the child's stdout if requested */ 2522 if (pipe(p) == -1) { 2523 error("%s: pipe: %s", tag, strerror(errno)); 2524 restore_return: 2525 if (restore_privs != NULL) 2526 restore_privs(); 2527 return 0; 2528 } 2529 if (restore_privs != NULL) 2530 restore_privs(); 2531 2532 switch ((pid = fork())) { 2533 case -1: /* error */ 2534 error("%s: fork: %s", tag, strerror(errno)); 2535 close(p[0]); 2536 close(p[1]); 2537 return 0; 2538 case 0: /* child */ 2539 /* Prepare a minimal environment for the child. */ 2540 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2541 nenv = 5; 2542 env = xcalloc(sizeof(*env), nenv); 2543 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2544 child_set_env(&env, &nenv, "USER", pw->pw_name); 2545 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2546 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2547 if ((cp = getenv("LANG")) != NULL) 2548 child_set_env(&env, &nenv, "LANG", cp); 2549 } 2550 2551 for (i = 1; i < NSIG; i++) 2552 ssh_signal(i, SIG_DFL); 2553 2554 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2555 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2556 strerror(errno)); 2557 _exit(1); 2558 } 2559 if (dup2(devnull, STDIN_FILENO) == -1) { 2560 error("%s: dup2: %s", tag, strerror(errno)); 2561 _exit(1); 2562 } 2563 2564 /* Set up stdout as requested; leave stderr in place for now. */ 2565 fd = -1; 2566 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2567 fd = p[1]; 2568 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2569 fd = devnull; 2570 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2571 error("%s: dup2: %s", tag, strerror(errno)); 2572 _exit(1); 2573 } 2574 closefrom(STDERR_FILENO + 1); 2575 2576 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2577 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2578 strerror(errno)); 2579 _exit(1); 2580 } 2581 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2582 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2583 strerror(errno)); 2584 _exit(1); 2585 } 2586 /* stdin is pointed to /dev/null at this point */ 2587 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2588 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2589 error("%s: dup2: %s", tag, strerror(errno)); 2590 _exit(1); 2591 } 2592 if (env != NULL) 2593 execve(av[0], av, env); 2594 else 2595 execv(av[0], av); 2596 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2597 command, strerror(errno)); 2598 _exit(127); 2599 default: /* parent */ 2600 break; 2601 } 2602 2603 close(p[1]); 2604 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2605 close(p[0]); 2606 else if ((f = fdopen(p[0], "r")) == NULL) { 2607 error("%s: fdopen: %s", tag, strerror(errno)); 2608 close(p[0]); 2609 /* Don't leave zombie child */ 2610 kill(pid, SIGTERM); 2611 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2612 ; 2613 return 0; 2614 } 2615 /* Success */ 2616 debug3_f("%s pid %ld", tag, (long)pid); 2617 if (child != NULL) 2618 *child = f; 2619 return pid; 2620 } 2621 2622 const char * 2623 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2624 { 2625 size_t i, envlen; 2626 2627 envlen = strlen(env); 2628 for (i = 0; i < nenvs; i++) { 2629 if (strncmp(envs[i], env, envlen) == 0 && 2630 envs[i][envlen] == '=') { 2631 return envs[i] + envlen + 1; 2632 } 2633 } 2634 return NULL; 2635 } 2636