1 /* $OpenBSD: misc.c,v 1.169 2021/08/09 23:47:44 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 "includes.h" 22 23 #include <sys/types.h> 24 #include <sys/ioctl.h> 25 #include <sys/socket.h> 26 #include <sys/stat.h> 27 #include <sys/time.h> 28 #include <sys/wait.h> 29 #include <sys/un.h> 30 31 #include <limits.h> 32 #ifdef HAVE_LIBGEN_H 33 # include <libgen.h> 34 #endif 35 #ifdef HAVE_POLL_H 36 #include <poll.h> 37 #endif 38 #include <signal.h> 39 #include <stdarg.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <time.h> 44 #include <unistd.h> 45 46 #include <netinet/in.h> 47 #include <netinet/in_systm.h> 48 #include <netinet/ip.h> 49 #include <netinet/tcp.h> 50 #include <arpa/inet.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <netdb.h> 56 #ifdef HAVE_PATHS_H 57 # include <paths.h> 58 #include <pwd.h> 59 #endif 60 #ifdef SSH_TUN_OPENBSD 61 #include <net/if.h> 62 #endif 63 64 #include "xmalloc.h" 65 #include "misc.h" 66 #include "log.h" 67 #include "ssh.h" 68 #include "sshbuf.h" 69 #include "ssherr.h" 70 #include "platform.h" 71 72 /* remove newline at end of string */ 73 char * 74 chop(char *s) 75 { 76 char *t = s; 77 while (*t) { 78 if (*t == '\n' || *t == '\r') { 79 *t = '\0'; 80 return s; 81 } 82 t++; 83 } 84 return s; 85 86 } 87 88 /* remove whitespace from end of string */ 89 void 90 rtrim(char *s) 91 { 92 size_t i; 93 94 if ((i = strlen(s)) == 0) 95 return; 96 for (i--; i > 0; i--) { 97 if (isspace((int)s[i])) 98 s[i] = '\0'; 99 } 100 } 101 102 /* set/unset filedescriptor to non-blocking */ 103 int 104 set_nonblock(int fd) 105 { 106 int val; 107 108 val = fcntl(fd, F_GETFL); 109 if (val == -1) { 110 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 111 return (-1); 112 } 113 if (val & O_NONBLOCK) { 114 debug3("fd %d is O_NONBLOCK", fd); 115 return (0); 116 } 117 debug2("fd %d setting O_NONBLOCK", fd); 118 val |= O_NONBLOCK; 119 if (fcntl(fd, F_SETFL, val) == -1) { 120 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 121 strerror(errno)); 122 return (-1); 123 } 124 return (0); 125 } 126 127 int 128 unset_nonblock(int fd) 129 { 130 int val; 131 132 val = fcntl(fd, F_GETFL); 133 if (val == -1) { 134 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 135 return (-1); 136 } 137 if (!(val & O_NONBLOCK)) { 138 debug3("fd %d is not O_NONBLOCK", fd); 139 return (0); 140 } 141 debug("fd %d clearing O_NONBLOCK", fd); 142 val &= ~O_NONBLOCK; 143 if (fcntl(fd, F_SETFL, val) == -1) { 144 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 145 fd, strerror(errno)); 146 return (-1); 147 } 148 return (0); 149 } 150 151 const char * 152 ssh_gai_strerror(int gaierr) 153 { 154 if (gaierr == EAI_SYSTEM && errno != 0) 155 return strerror(errno); 156 return gai_strerror(gaierr); 157 } 158 159 /* disable nagle on socket */ 160 void 161 set_nodelay(int fd) 162 { 163 int opt; 164 socklen_t optlen; 165 166 optlen = sizeof opt; 167 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 168 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 169 return; 170 } 171 if (opt == 1) { 172 debug2("fd %d is TCP_NODELAY", fd); 173 return; 174 } 175 opt = 1; 176 debug2("fd %d setting TCP_NODELAY", fd); 177 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 178 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 179 } 180 181 /* Allow local port reuse in TIME_WAIT */ 182 int 183 set_reuseaddr(int fd) 184 { 185 int on = 1; 186 187 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 188 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 189 return -1; 190 } 191 return 0; 192 } 193 194 /* Get/set routing domain */ 195 char * 196 get_rdomain(int fd) 197 { 198 #if defined(HAVE_SYS_GET_RDOMAIN) 199 return sys_get_rdomain(fd); 200 #elif defined(__OpenBSD__) 201 int rtable; 202 char *ret; 203 socklen_t len = sizeof(rtable); 204 205 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 206 error("Failed to get routing domain for fd %d: %s", 207 fd, strerror(errno)); 208 return NULL; 209 } 210 xasprintf(&ret, "%d", rtable); 211 return ret; 212 #else /* defined(__OpenBSD__) */ 213 return NULL; 214 #endif 215 } 216 217 int 218 set_rdomain(int fd, const char *name) 219 { 220 #if defined(HAVE_SYS_SET_RDOMAIN) 221 return sys_set_rdomain(fd, name); 222 #elif defined(__OpenBSD__) 223 int rtable; 224 const char *errstr; 225 226 if (name == NULL) 227 return 0; /* default table */ 228 229 rtable = (int)strtonum(name, 0, 255, &errstr); 230 if (errstr != NULL) { 231 /* Shouldn't happen */ 232 error("Invalid routing domain \"%s\": %s", name, errstr); 233 return -1; 234 } 235 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 236 &rtable, sizeof(rtable)) == -1) { 237 error("Failed to set routing domain %d on fd %d: %s", 238 rtable, fd, strerror(errno)); 239 return -1; 240 } 241 return 0; 242 #else /* defined(__OpenBSD__) */ 243 error("Setting routing domain is not supported on this platform"); 244 return -1; 245 #endif 246 } 247 248 int 249 get_sock_af(int fd) 250 { 251 struct sockaddr_storage to; 252 socklen_t tolen = sizeof(to); 253 254 memset(&to, 0, sizeof(to)); 255 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 256 return -1; 257 #ifdef IPV4_IN_IPV6 258 if (to.ss_family == AF_INET6 && 259 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) 260 return AF_INET; 261 #endif 262 return to.ss_family; 263 } 264 265 void 266 set_sock_tos(int fd, int tos) 267 { 268 #ifndef IP_TOS_IS_BROKEN 269 int af; 270 271 switch ((af = get_sock_af(fd))) { 272 case -1: 273 /* assume not a socket */ 274 break; 275 case AF_INET: 276 # ifdef IP_TOS 277 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 278 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 279 &tos, sizeof(tos)) == -1) { 280 error("setsockopt socket %d IP_TOS %d: %s:", 281 fd, tos, strerror(errno)); 282 } 283 # endif /* IP_TOS */ 284 break; 285 case AF_INET6: 286 # ifdef IPV6_TCLASS 287 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 288 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 289 &tos, sizeof(tos)) == -1) { 290 error("setsockopt socket %d IPV6_TCLASS %d: %.100s:", 291 fd, tos, strerror(errno)); 292 } 293 # endif /* IPV6_TCLASS */ 294 break; 295 default: 296 debug2_f("unsupported socket family %d", af); 297 break; 298 } 299 #endif /* IP_TOS_IS_BROKEN */ 300 } 301 302 /* 303 * Wait up to *timeoutp milliseconds for events on fd. Updates 304 * *timeoutp with time remaining. 305 * Returns 0 if fd ready or -1 on timeout or error (see errno). 306 */ 307 static int 308 waitfd(int fd, int *timeoutp, short events) 309 { 310 struct pollfd pfd; 311 struct timeval t_start; 312 int oerrno, r; 313 314 pfd.fd = fd; 315 pfd.events = events; 316 for (; *timeoutp >= 0;) { 317 monotime_tv(&t_start); 318 r = poll(&pfd, 1, *timeoutp); 319 oerrno = errno; 320 ms_subtract_diff(&t_start, timeoutp); 321 errno = oerrno; 322 if (r > 0) 323 return 0; 324 else if (r == -1 && errno != EAGAIN && errno != EINTR) 325 return -1; 326 else if (r == 0) 327 break; 328 } 329 /* timeout */ 330 errno = ETIMEDOUT; 331 return -1; 332 } 333 334 /* 335 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 336 * *timeoutp with time remaining. 337 * Returns 0 if fd ready or -1 on timeout or error (see errno). 338 */ 339 int 340 waitrfd(int fd, int *timeoutp) { 341 return waitfd(fd, timeoutp, POLLIN); 342 } 343 344 /* 345 * Attempt a non-blocking connect(2) to the specified address, waiting up to 346 * *timeoutp milliseconds for the connection to complete. If the timeout is 347 * <=0, then wait indefinitely. 348 * 349 * Returns 0 on success or -1 on failure. 350 */ 351 int 352 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 353 socklen_t addrlen, int *timeoutp) 354 { 355 int optval = 0; 356 socklen_t optlen = sizeof(optval); 357 358 /* No timeout: just do a blocking connect() */ 359 if (timeoutp == NULL || *timeoutp <= 0) 360 return connect(sockfd, serv_addr, addrlen); 361 362 set_nonblock(sockfd); 363 for (;;) { 364 if (connect(sockfd, serv_addr, addrlen) == 0) { 365 /* Succeeded already? */ 366 unset_nonblock(sockfd); 367 return 0; 368 } else if (errno == EINTR) 369 continue; 370 else if (errno != EINPROGRESS) 371 return -1; 372 break; 373 } 374 375 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) 376 return -1; 377 378 /* Completed or failed */ 379 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 380 debug("getsockopt: %s", strerror(errno)); 381 return -1; 382 } 383 if (optval != 0) { 384 errno = optval; 385 return -1; 386 } 387 unset_nonblock(sockfd); 388 return 0; 389 } 390 391 /* Characters considered whitespace in strsep calls. */ 392 #define WHITESPACE " \t\r\n" 393 #define QUOTE "\"" 394 395 /* return next token in configuration line */ 396 static char * 397 strdelim_internal(char **s, int split_equals) 398 { 399 char *old; 400 int wspace = 0; 401 402 if (*s == NULL) 403 return NULL; 404 405 old = *s; 406 407 *s = strpbrk(*s, 408 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 409 if (*s == NULL) 410 return (old); 411 412 if (*s[0] == '\"') { 413 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 414 /* Find matching quote */ 415 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 416 return (NULL); /* no matching quote */ 417 } else { 418 *s[0] = '\0'; 419 *s += strspn(*s + 1, WHITESPACE) + 1; 420 return (old); 421 } 422 } 423 424 /* Allow only one '=' to be skipped */ 425 if (split_equals && *s[0] == '=') 426 wspace = 1; 427 *s[0] = '\0'; 428 429 /* Skip any extra whitespace after first token */ 430 *s += strspn(*s + 1, WHITESPACE) + 1; 431 if (split_equals && *s[0] == '=' && !wspace) 432 *s += strspn(*s + 1, WHITESPACE) + 1; 433 434 return (old); 435 } 436 437 /* 438 * Return next token in configuration line; splts on whitespace or a 439 * single '=' character. 440 */ 441 char * 442 strdelim(char **s) 443 { 444 return strdelim_internal(s, 1); 445 } 446 447 /* 448 * Return next token in configuration line; splts on whitespace only. 449 */ 450 char * 451 strdelimw(char **s) 452 { 453 return strdelim_internal(s, 0); 454 } 455 456 struct passwd * 457 pwcopy(struct passwd *pw) 458 { 459 struct passwd *copy = xcalloc(1, sizeof(*copy)); 460 461 copy->pw_name = xstrdup(pw->pw_name); 462 copy->pw_passwd = xstrdup(pw->pw_passwd == NULL ? "*" : pw->pw_passwd); 463 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 464 copy->pw_gecos = xstrdup(pw->pw_gecos); 465 #endif 466 copy->pw_uid = pw->pw_uid; 467 copy->pw_gid = pw->pw_gid; 468 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE 469 copy->pw_expire = pw->pw_expire; 470 #endif 471 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE 472 copy->pw_change = pw->pw_change; 473 #endif 474 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 475 copy->pw_class = xstrdup(pw->pw_class); 476 #endif 477 copy->pw_dir = xstrdup(pw->pw_dir); 478 copy->pw_shell = xstrdup(pw->pw_shell); 479 return copy; 480 } 481 482 /* 483 * Convert ASCII string to TCP/IP port number. 484 * Port must be >=0 and <=65535. 485 * Return -1 if invalid. 486 */ 487 int 488 a2port(const char *s) 489 { 490 struct servent *se; 491 long long port; 492 const char *errstr; 493 494 port = strtonum(s, 0, 65535, &errstr); 495 if (errstr == NULL) 496 return (int)port; 497 if ((se = getservbyname(s, "tcp")) != NULL) 498 return ntohs(se->s_port); 499 return -1; 500 } 501 502 int 503 a2tun(const char *s, int *remote) 504 { 505 const char *errstr = NULL; 506 char *sp, *ep; 507 int tun; 508 509 if (remote != NULL) { 510 *remote = SSH_TUNID_ANY; 511 sp = xstrdup(s); 512 if ((ep = strchr(sp, ':')) == NULL) { 513 free(sp); 514 return (a2tun(s, NULL)); 515 } 516 ep[0] = '\0'; ep++; 517 *remote = a2tun(ep, NULL); 518 tun = a2tun(sp, NULL); 519 free(sp); 520 return (*remote == SSH_TUNID_ERR ? *remote : tun); 521 } 522 523 if (strcasecmp(s, "any") == 0) 524 return (SSH_TUNID_ANY); 525 526 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 527 if (errstr != NULL) 528 return (SSH_TUNID_ERR); 529 530 return (tun); 531 } 532 533 #define SECONDS 1 534 #define MINUTES (SECONDS * 60) 535 #define HOURS (MINUTES * 60) 536 #define DAYS (HOURS * 24) 537 #define WEEKS (DAYS * 7) 538 539 /* 540 * Convert a time string into seconds; format is 541 * a sequence of: 542 * time[qualifier] 543 * 544 * Valid time qualifiers are: 545 * <none> seconds 546 * s|S seconds 547 * m|M minutes 548 * h|H hours 549 * d|D days 550 * w|W weeks 551 * 552 * Examples: 553 * 90m 90 minutes 554 * 1h30m 90 minutes 555 * 2d 2 days 556 * 1w 1 week 557 * 558 * Return -1 if time string is invalid. 559 */ 560 int 561 convtime(const char *s) 562 { 563 long total, secs, multiplier; 564 const char *p; 565 char *endp; 566 567 errno = 0; 568 total = 0; 569 p = s; 570 571 if (p == NULL || *p == '\0') 572 return -1; 573 574 while (*p) { 575 secs = strtol(p, &endp, 10); 576 if (p == endp || 577 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 578 secs < 0) 579 return -1; 580 581 multiplier = 1; 582 switch (*endp++) { 583 case '\0': 584 endp--; 585 break; 586 case 's': 587 case 'S': 588 break; 589 case 'm': 590 case 'M': 591 multiplier = MINUTES; 592 break; 593 case 'h': 594 case 'H': 595 multiplier = HOURS; 596 break; 597 case 'd': 598 case 'D': 599 multiplier = DAYS; 600 break; 601 case 'w': 602 case 'W': 603 multiplier = WEEKS; 604 break; 605 default: 606 return -1; 607 } 608 if (secs > INT_MAX / multiplier) 609 return -1; 610 secs *= multiplier; 611 if (total > INT_MAX - secs) 612 return -1; 613 total += secs; 614 if (total < 0) 615 return -1; 616 p = endp; 617 } 618 619 return total; 620 } 621 622 #define TF_BUFS 8 623 #define TF_LEN 9 624 625 const char * 626 fmt_timeframe(time_t t) 627 { 628 char *buf; 629 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 630 static int idx = 0; 631 unsigned int sec, min, hrs, day; 632 unsigned long long week; 633 634 buf = tfbuf[idx++]; 635 if (idx == TF_BUFS) 636 idx = 0; 637 638 week = t; 639 640 sec = week % 60; 641 week /= 60; 642 min = week % 60; 643 week /= 60; 644 hrs = week % 24; 645 week /= 24; 646 day = week % 7; 647 week /= 7; 648 649 if (week > 0) 650 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 651 else if (day > 0) 652 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 653 else 654 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 655 656 return (buf); 657 } 658 659 /* 660 * Returns a standardized host+port identifier string. 661 * Caller must free returned string. 662 */ 663 char * 664 put_host_port(const char *host, u_short port) 665 { 666 char *hoststr; 667 668 if (port == 0 || port == SSH_DEFAULT_PORT) 669 return(xstrdup(host)); 670 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 671 fatal("put_host_port: asprintf: %s", strerror(errno)); 672 debug3("put_host_port: %s", hoststr); 673 return hoststr; 674 } 675 676 /* 677 * Search for next delimiter between hostnames/addresses and ports. 678 * Argument may be modified (for termination). 679 * Returns *cp if parsing succeeds. 680 * *cp is set to the start of the next field, if one was found. 681 * The delimiter char, if present, is stored in delim. 682 * If this is the last field, *cp is set to NULL. 683 */ 684 char * 685 hpdelim2(char **cp, char *delim) 686 { 687 char *s, *old; 688 689 if (cp == NULL || *cp == NULL) 690 return NULL; 691 692 old = s = *cp; 693 if (*s == '[') { 694 if ((s = strchr(s, ']')) == NULL) 695 return NULL; 696 else 697 s++; 698 } else if ((s = strpbrk(s, ":/")) == NULL) 699 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 700 701 switch (*s) { 702 case '\0': 703 *cp = NULL; /* no more fields*/ 704 break; 705 706 case ':': 707 case '/': 708 if (delim != NULL) 709 *delim = *s; 710 *s = '\0'; /* terminate */ 711 *cp = s + 1; 712 break; 713 714 default: 715 return NULL; 716 } 717 718 return old; 719 } 720 721 char * 722 hpdelim(char **cp) 723 { 724 return hpdelim2(cp, NULL); 725 } 726 727 char * 728 cleanhostname(char *host) 729 { 730 if (*host == '[' && host[strlen(host) - 1] == ']') { 731 host[strlen(host) - 1] = '\0'; 732 return (host + 1); 733 } else 734 return host; 735 } 736 737 char * 738 colon(char *cp) 739 { 740 int flag = 0; 741 742 if (*cp == ':') /* Leading colon is part of file name. */ 743 return NULL; 744 if (*cp == '[') 745 flag = 1; 746 747 for (; *cp; ++cp) { 748 if (*cp == '@' && *(cp+1) == '[') 749 flag = 1; 750 if (*cp == ']' && *(cp+1) == ':' && flag) 751 return (cp+1); 752 if (*cp == ':' && !flag) 753 return (cp); 754 if (*cp == '/') 755 return NULL; 756 } 757 return NULL; 758 } 759 760 /* 761 * Parse a [user@]host:[path] string. 762 * Caller must free returned user, host and path. 763 * Any of the pointer return arguments may be NULL (useful for syntax checking). 764 * If user was not specified then *userp will be set to NULL. 765 * If host was not specified then *hostp will be set to NULL. 766 * If path was not specified then *pathp will be set to ".". 767 * Returns 0 on success, -1 on failure. 768 */ 769 int 770 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 771 { 772 char *user = NULL, *host = NULL, *path = NULL; 773 char *sdup, *tmp; 774 int ret = -1; 775 776 if (userp != NULL) 777 *userp = NULL; 778 if (hostp != NULL) 779 *hostp = NULL; 780 if (pathp != NULL) 781 *pathp = NULL; 782 783 sdup = xstrdup(s); 784 785 /* Check for remote syntax: [user@]host:[path] */ 786 if ((tmp = colon(sdup)) == NULL) 787 goto out; 788 789 /* Extract optional path */ 790 *tmp++ = '\0'; 791 if (*tmp == '\0') 792 tmp = "."; 793 path = xstrdup(tmp); 794 795 /* Extract optional user and mandatory host */ 796 tmp = strrchr(sdup, '@'); 797 if (tmp != NULL) { 798 *tmp++ = '\0'; 799 host = xstrdup(cleanhostname(tmp)); 800 if (*sdup != '\0') 801 user = xstrdup(sdup); 802 } else { 803 host = xstrdup(cleanhostname(sdup)); 804 user = NULL; 805 } 806 807 /* Success */ 808 if (userp != NULL) { 809 *userp = user; 810 user = NULL; 811 } 812 if (hostp != NULL) { 813 *hostp = host; 814 host = NULL; 815 } 816 if (pathp != NULL) { 817 *pathp = path; 818 path = NULL; 819 } 820 ret = 0; 821 out: 822 free(sdup); 823 free(user); 824 free(host); 825 free(path); 826 return ret; 827 } 828 829 /* 830 * Parse a [user@]host[:port] string. 831 * Caller must free returned user and host. 832 * Any of the pointer return arguments may be NULL (useful for syntax checking). 833 * If user was not specified then *userp will be set to NULL. 834 * If port was not specified then *portp will be -1. 835 * Returns 0 on success, -1 on failure. 836 */ 837 int 838 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 839 { 840 char *sdup, *cp, *tmp; 841 char *user = NULL, *host = NULL; 842 int port = -1, ret = -1; 843 844 if (userp != NULL) 845 *userp = NULL; 846 if (hostp != NULL) 847 *hostp = NULL; 848 if (portp != NULL) 849 *portp = -1; 850 851 if ((sdup = tmp = strdup(s)) == NULL) 852 return -1; 853 /* Extract optional username */ 854 if ((cp = strrchr(tmp, '@')) != NULL) { 855 *cp = '\0'; 856 if (*tmp == '\0') 857 goto out; 858 if ((user = strdup(tmp)) == NULL) 859 goto out; 860 tmp = cp + 1; 861 } 862 /* Extract mandatory hostname */ 863 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 864 goto out; 865 host = xstrdup(cleanhostname(cp)); 866 /* Convert and verify optional port */ 867 if (tmp != NULL && *tmp != '\0') { 868 if ((port = a2port(tmp)) <= 0) 869 goto out; 870 } 871 /* Success */ 872 if (userp != NULL) { 873 *userp = user; 874 user = NULL; 875 } 876 if (hostp != NULL) { 877 *hostp = host; 878 host = NULL; 879 } 880 if (portp != NULL) 881 *portp = port; 882 ret = 0; 883 out: 884 free(sdup); 885 free(user); 886 free(host); 887 return ret; 888 } 889 890 /* 891 * Converts a two-byte hex string to decimal. 892 * Returns the decimal value or -1 for invalid input. 893 */ 894 static int 895 hexchar(const char *s) 896 { 897 unsigned char result[2]; 898 int i; 899 900 for (i = 0; i < 2; i++) { 901 if (s[i] >= '0' && s[i] <= '9') 902 result[i] = (unsigned char)(s[i] - '0'); 903 else if (s[i] >= 'a' && s[i] <= 'f') 904 result[i] = (unsigned char)(s[i] - 'a') + 10; 905 else if (s[i] >= 'A' && s[i] <= 'F') 906 result[i] = (unsigned char)(s[i] - 'A') + 10; 907 else 908 return -1; 909 } 910 return (result[0] << 4) | result[1]; 911 } 912 913 /* 914 * Decode an url-encoded string. 915 * Returns a newly allocated string on success or NULL on failure. 916 */ 917 static char * 918 urldecode(const char *src) 919 { 920 char *ret, *dst; 921 int ch; 922 923 ret = xmalloc(strlen(src) + 1); 924 for (dst = ret; *src != '\0'; src++) { 925 switch (*src) { 926 case '+': 927 *dst++ = ' '; 928 break; 929 case '%': 930 if (!isxdigit((unsigned char)src[1]) || 931 !isxdigit((unsigned char)src[2]) || 932 (ch = hexchar(src + 1)) == -1) { 933 free(ret); 934 return NULL; 935 } 936 *dst++ = ch; 937 src += 2; 938 break; 939 default: 940 *dst++ = *src; 941 break; 942 } 943 } 944 *dst = '\0'; 945 946 return ret; 947 } 948 949 /* 950 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 951 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 952 * Either user or path may be url-encoded (but not host or port). 953 * Caller must free returned user, host and path. 954 * Any of the pointer return arguments may be NULL (useful for syntax checking) 955 * but the scheme must always be specified. 956 * If user was not specified then *userp will be set to NULL. 957 * If port was not specified then *portp will be -1. 958 * If path was not specified then *pathp will be set to NULL. 959 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 960 */ 961 int 962 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 963 int *portp, char **pathp) 964 { 965 char *uridup, *cp, *tmp, ch; 966 char *user = NULL, *host = NULL, *path = NULL; 967 int port = -1, ret = -1; 968 size_t len; 969 970 len = strlen(scheme); 971 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 972 return 1; 973 uri += len + 3; 974 975 if (userp != NULL) 976 *userp = NULL; 977 if (hostp != NULL) 978 *hostp = NULL; 979 if (portp != NULL) 980 *portp = -1; 981 if (pathp != NULL) 982 *pathp = NULL; 983 984 uridup = tmp = xstrdup(uri); 985 986 /* Extract optional ssh-info (username + connection params) */ 987 if ((cp = strchr(tmp, '@')) != NULL) { 988 char *delim; 989 990 *cp = '\0'; 991 /* Extract username and connection params */ 992 if ((delim = strchr(tmp, ';')) != NULL) { 993 /* Just ignore connection params for now */ 994 *delim = '\0'; 995 } 996 if (*tmp == '\0') { 997 /* Empty username */ 998 goto out; 999 } 1000 if ((user = urldecode(tmp)) == NULL) 1001 goto out; 1002 tmp = cp + 1; 1003 } 1004 1005 /* Extract mandatory hostname */ 1006 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 1007 goto out; 1008 host = xstrdup(cleanhostname(cp)); 1009 if (!valid_domain(host, 0, NULL)) 1010 goto out; 1011 1012 if (tmp != NULL && *tmp != '\0') { 1013 if (ch == ':') { 1014 /* Convert and verify port. */ 1015 if ((cp = strchr(tmp, '/')) != NULL) 1016 *cp = '\0'; 1017 if ((port = a2port(tmp)) <= 0) 1018 goto out; 1019 tmp = cp ? cp + 1 : NULL; 1020 } 1021 if (tmp != NULL && *tmp != '\0') { 1022 /* Extract optional path */ 1023 if ((path = urldecode(tmp)) == NULL) 1024 goto out; 1025 } 1026 } 1027 1028 /* Success */ 1029 if (userp != NULL) { 1030 *userp = user; 1031 user = NULL; 1032 } 1033 if (hostp != NULL) { 1034 *hostp = host; 1035 host = NULL; 1036 } 1037 if (portp != NULL) 1038 *portp = port; 1039 if (pathp != NULL) { 1040 *pathp = path; 1041 path = NULL; 1042 } 1043 ret = 0; 1044 out: 1045 free(uridup); 1046 free(user); 1047 free(host); 1048 free(path); 1049 return ret; 1050 } 1051 1052 /* function to assist building execv() arguments */ 1053 void 1054 addargs(arglist *args, char *fmt, ...) 1055 { 1056 va_list ap; 1057 char *cp; 1058 u_int nalloc; 1059 int r; 1060 1061 va_start(ap, fmt); 1062 r = vasprintf(&cp, fmt, ap); 1063 va_end(ap); 1064 if (r == -1) 1065 fatal("addargs: argument too long"); 1066 1067 nalloc = args->nalloc; 1068 if (args->list == NULL) { 1069 nalloc = 32; 1070 args->num = 0; 1071 } else if (args->num+2 >= nalloc) 1072 nalloc *= 2; 1073 1074 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 1075 args->nalloc = nalloc; 1076 args->list[args->num++] = cp; 1077 args->list[args->num] = NULL; 1078 } 1079 1080 void 1081 replacearg(arglist *args, u_int which, char *fmt, ...) 1082 { 1083 va_list ap; 1084 char *cp; 1085 int r; 1086 1087 va_start(ap, fmt); 1088 r = vasprintf(&cp, fmt, ap); 1089 va_end(ap); 1090 if (r == -1) 1091 fatal("replacearg: argument too long"); 1092 1093 if (which >= args->num) 1094 fatal("replacearg: tried to replace invalid arg %d >= %d", 1095 which, args->num); 1096 free(args->list[which]); 1097 args->list[which] = cp; 1098 } 1099 1100 void 1101 freeargs(arglist *args) 1102 { 1103 u_int i; 1104 1105 if (args->list != NULL) { 1106 for (i = 0; i < args->num; i++) 1107 free(args->list[i]); 1108 free(args->list); 1109 args->nalloc = args->num = 0; 1110 args->list = NULL; 1111 } 1112 } 1113 1114 /* 1115 * Expands tildes in the file name. Returns data allocated by xmalloc. 1116 * Warning: this calls getpw*. 1117 */ 1118 int 1119 tilde_expand(const char *filename, uid_t uid, char **retp) 1120 { 1121 const char *path, *sep; 1122 char user[128], *ret; 1123 struct passwd *pw; 1124 u_int len, slash; 1125 1126 if (*filename != '~') { 1127 *retp = xstrdup(filename); 1128 return 0; 1129 } 1130 filename++; 1131 1132 path = strchr(filename, '/'); 1133 if (path != NULL && path > filename) { /* ~user/path */ 1134 slash = path - filename; 1135 if (slash > sizeof(user) - 1) { 1136 error_f("~username too long"); 1137 return -1; 1138 } 1139 memcpy(user, filename, slash); 1140 user[slash] = '\0'; 1141 if ((pw = getpwnam(user)) == NULL) { 1142 error_f("No such user %s", user); 1143 return -1; 1144 } 1145 } else if ((pw = getpwuid(uid)) == NULL) { /* ~/path */ 1146 error_f("No such uid %ld", (long)uid); 1147 return -1; 1148 } 1149 1150 /* Make sure directory has a trailing '/' */ 1151 len = strlen(pw->pw_dir); 1152 if (len == 0 || pw->pw_dir[len - 1] != '/') 1153 sep = "/"; 1154 else 1155 sep = ""; 1156 1157 /* Skip leading '/' from specified path */ 1158 if (path != NULL) 1159 filename = path + 1; 1160 1161 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) { 1162 error_f("Path too long"); 1163 return -1; 1164 } 1165 1166 *retp = ret; 1167 return 0; 1168 } 1169 1170 char * 1171 tilde_expand_filename(const char *filename, uid_t uid) 1172 { 1173 char *ret; 1174 1175 if (tilde_expand(filename, uid, &ret) != 0) 1176 cleanup_exit(255); 1177 return ret; 1178 } 1179 1180 /* 1181 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1182 * substitutions. A number of escapes may be specified as 1183 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1184 * by a NULL escape_char. Returns replaced string in memory allocated by 1185 * xmalloc which the caller must free. 1186 */ 1187 static char * 1188 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1189 const char *string, va_list ap) 1190 { 1191 #define EXPAND_MAX_KEYS 16 1192 u_int num_keys = 0, i; 1193 struct { 1194 const char *key; 1195 const char *repl; 1196 } keys[EXPAND_MAX_KEYS]; 1197 struct sshbuf *buf; 1198 int r, missingvar = 0; 1199 char *ret = NULL, *var, *varend, *val; 1200 size_t len; 1201 1202 if ((buf = sshbuf_new()) == NULL) 1203 fatal_f("sshbuf_new failed"); 1204 if (parseerror == NULL) 1205 fatal_f("null parseerror arg"); 1206 *parseerror = 1; 1207 1208 /* Gather keys if we're doing percent expansion. */ 1209 if (percent) { 1210 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1211 keys[num_keys].key = va_arg(ap, char *); 1212 if (keys[num_keys].key == NULL) 1213 break; 1214 keys[num_keys].repl = va_arg(ap, char *); 1215 if (keys[num_keys].repl == NULL) { 1216 fatal_f("NULL replacement for token %s", 1217 keys[num_keys].key); 1218 } 1219 } 1220 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1221 fatal_f("too many keys"); 1222 if (num_keys == 0) 1223 fatal_f("percent expansion without token list"); 1224 } 1225 1226 /* Expand string */ 1227 for (i = 0; *string != '\0'; string++) { 1228 /* Optionally process ${ENVIRONMENT} expansions. */ 1229 if (dollar && string[0] == '$' && string[1] == '{') { 1230 string += 2; /* skip over '${' */ 1231 if ((varend = strchr(string, '}')) == NULL) { 1232 error_f("environment variable '%s' missing " 1233 "closing '}'", string); 1234 goto out; 1235 } 1236 len = varend - string; 1237 if (len == 0) { 1238 error_f("zero-length environment variable"); 1239 goto out; 1240 } 1241 var = xmalloc(len + 1); 1242 (void)strlcpy(var, string, len + 1); 1243 if ((val = getenv(var)) == NULL) { 1244 error_f("env var ${%s} has no value", var); 1245 missingvar = 1; 1246 } else { 1247 debug3_f("expand ${%s} -> '%s'", var, val); 1248 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1249 fatal_fr(r, "sshbuf_put ${}"); 1250 } 1251 free(var); 1252 string += len; 1253 continue; 1254 } 1255 1256 /* 1257 * Process percent expansions if we have a list of TOKENs. 1258 * If we're not doing percent expansion everything just gets 1259 * appended here. 1260 */ 1261 if (*string != '%' || !percent) { 1262 append: 1263 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1264 fatal_fr(r, "sshbuf_put_u8 %%"); 1265 continue; 1266 } 1267 string++; 1268 /* %% case */ 1269 if (*string == '%') 1270 goto append; 1271 if (*string == '\0') { 1272 error_f("invalid format"); 1273 goto out; 1274 } 1275 for (i = 0; i < num_keys; i++) { 1276 if (strchr(keys[i].key, *string) != NULL) { 1277 if ((r = sshbuf_put(buf, keys[i].repl, 1278 strlen(keys[i].repl))) != 0) 1279 fatal_fr(r, "sshbuf_put %%-repl"); 1280 break; 1281 } 1282 } 1283 if (i >= num_keys) { 1284 error_f("unknown key %%%c", *string); 1285 goto out; 1286 } 1287 } 1288 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1289 fatal_f("sshbuf_dup_string failed"); 1290 *parseerror = 0; 1291 out: 1292 sshbuf_free(buf); 1293 return *parseerror ? NULL : ret; 1294 #undef EXPAND_MAX_KEYS 1295 } 1296 1297 /* 1298 * Expand only environment variables. 1299 * Note that although this function is variadic like the other similar 1300 * functions, any such arguments will be unused. 1301 */ 1302 1303 char * 1304 dollar_expand(int *parseerr, const char *string, ...) 1305 { 1306 char *ret; 1307 int err; 1308 va_list ap; 1309 1310 va_start(ap, string); 1311 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1312 va_end(ap); 1313 if (parseerr != NULL) 1314 *parseerr = err; 1315 return ret; 1316 } 1317 1318 /* 1319 * Returns expanded string or NULL if a specified environment variable is 1320 * not defined, or calls fatal if the string is invalid. 1321 */ 1322 char * 1323 percent_expand(const char *string, ...) 1324 { 1325 char *ret; 1326 int err; 1327 va_list ap; 1328 1329 va_start(ap, string); 1330 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1331 va_end(ap); 1332 if (err) 1333 fatal_f("failed"); 1334 return ret; 1335 } 1336 1337 /* 1338 * Returns expanded string or NULL if a specified environment variable is 1339 * not defined, or calls fatal if the string is invalid. 1340 */ 1341 char * 1342 percent_dollar_expand(const char *string, ...) 1343 { 1344 char *ret; 1345 int err; 1346 va_list ap; 1347 1348 va_start(ap, string); 1349 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1350 va_end(ap); 1351 if (err) 1352 fatal_f("failed"); 1353 return ret; 1354 } 1355 1356 int 1357 tun_open(int tun, int mode, char **ifname) 1358 { 1359 #if defined(CUSTOM_SYS_TUN_OPEN) 1360 return (sys_tun_open(tun, mode, ifname)); 1361 #elif defined(SSH_TUN_OPENBSD) 1362 struct ifreq ifr; 1363 char name[100]; 1364 int fd = -1, sock; 1365 const char *tunbase = "tun"; 1366 1367 if (ifname != NULL) 1368 *ifname = NULL; 1369 1370 if (mode == SSH_TUNMODE_ETHERNET) 1371 tunbase = "tap"; 1372 1373 /* Open the tunnel device */ 1374 if (tun <= SSH_TUNID_MAX) { 1375 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1376 fd = open(name, O_RDWR); 1377 } else if (tun == SSH_TUNID_ANY) { 1378 for (tun = 100; tun >= 0; tun--) { 1379 snprintf(name, sizeof(name), "/dev/%s%d", 1380 tunbase, tun); 1381 if ((fd = open(name, O_RDWR)) >= 0) 1382 break; 1383 } 1384 } else { 1385 debug_f("invalid tunnel %u", tun); 1386 return -1; 1387 } 1388 1389 if (fd == -1) { 1390 debug_f("%s open: %s", name, strerror(errno)); 1391 return -1; 1392 } 1393 1394 debug_f("%s mode %d fd %d", name, mode, fd); 1395 1396 /* Bring interface up if it is not already */ 1397 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1398 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1399 goto failed; 1400 1401 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1402 debug_f("get interface %s flags: %s", ifr.ifr_name, 1403 strerror(errno)); 1404 goto failed; 1405 } 1406 1407 if (!(ifr.ifr_flags & IFF_UP)) { 1408 ifr.ifr_flags |= IFF_UP; 1409 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1410 debug_f("activate interface %s: %s", ifr.ifr_name, 1411 strerror(errno)); 1412 goto failed; 1413 } 1414 } 1415 1416 if (ifname != NULL) 1417 *ifname = xstrdup(ifr.ifr_name); 1418 1419 close(sock); 1420 return fd; 1421 1422 failed: 1423 if (fd >= 0) 1424 close(fd); 1425 if (sock >= 0) 1426 close(sock); 1427 return -1; 1428 #else 1429 error("Tunnel interfaces are not supported on this platform"); 1430 return (-1); 1431 #endif 1432 } 1433 1434 void 1435 sanitise_stdfd(void) 1436 { 1437 int nullfd, dupfd; 1438 1439 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1440 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1441 strerror(errno)); 1442 exit(1); 1443 } 1444 while (++dupfd <= STDERR_FILENO) { 1445 /* Only populate closed fds. */ 1446 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1447 if (dup2(nullfd, dupfd) == -1) { 1448 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1449 exit(1); 1450 } 1451 } 1452 } 1453 if (nullfd > STDERR_FILENO) 1454 close(nullfd); 1455 } 1456 1457 char * 1458 tohex(const void *vp, size_t l) 1459 { 1460 const u_char *p = (const u_char *)vp; 1461 char b[3], *r; 1462 size_t i, hl; 1463 1464 if (l > 65536) 1465 return xstrdup("tohex: length > 65536"); 1466 1467 hl = l * 2 + 1; 1468 r = xcalloc(1, hl); 1469 for (i = 0; i < l; i++) { 1470 snprintf(b, sizeof(b), "%02x", p[i]); 1471 strlcat(r, b, hl); 1472 } 1473 return (r); 1474 } 1475 1476 /* 1477 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1478 * then the separator 'sep' will be prepended before the formatted arguments. 1479 * Extended strings are heap allocated. 1480 */ 1481 void 1482 xextendf(char **sp, const char *sep, const char *fmt, ...) 1483 { 1484 va_list ap; 1485 char *tmp1, *tmp2; 1486 1487 va_start(ap, fmt); 1488 xvasprintf(&tmp1, fmt, ap); 1489 va_end(ap); 1490 1491 if (*sp == NULL || **sp == '\0') { 1492 free(*sp); 1493 *sp = tmp1; 1494 return; 1495 } 1496 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1497 free(tmp1); 1498 free(*sp); 1499 *sp = tmp2; 1500 } 1501 1502 1503 u_int64_t 1504 get_u64(const void *vp) 1505 { 1506 const u_char *p = (const u_char *)vp; 1507 u_int64_t v; 1508 1509 v = (u_int64_t)p[0] << 56; 1510 v |= (u_int64_t)p[1] << 48; 1511 v |= (u_int64_t)p[2] << 40; 1512 v |= (u_int64_t)p[3] << 32; 1513 v |= (u_int64_t)p[4] << 24; 1514 v |= (u_int64_t)p[5] << 16; 1515 v |= (u_int64_t)p[6] << 8; 1516 v |= (u_int64_t)p[7]; 1517 1518 return (v); 1519 } 1520 1521 u_int32_t 1522 get_u32(const void *vp) 1523 { 1524 const u_char *p = (const u_char *)vp; 1525 u_int32_t v; 1526 1527 v = (u_int32_t)p[0] << 24; 1528 v |= (u_int32_t)p[1] << 16; 1529 v |= (u_int32_t)p[2] << 8; 1530 v |= (u_int32_t)p[3]; 1531 1532 return (v); 1533 } 1534 1535 u_int32_t 1536 get_u32_le(const void *vp) 1537 { 1538 const u_char *p = (const u_char *)vp; 1539 u_int32_t v; 1540 1541 v = (u_int32_t)p[0]; 1542 v |= (u_int32_t)p[1] << 8; 1543 v |= (u_int32_t)p[2] << 16; 1544 v |= (u_int32_t)p[3] << 24; 1545 1546 return (v); 1547 } 1548 1549 u_int16_t 1550 get_u16(const void *vp) 1551 { 1552 const u_char *p = (const u_char *)vp; 1553 u_int16_t v; 1554 1555 v = (u_int16_t)p[0] << 8; 1556 v |= (u_int16_t)p[1]; 1557 1558 return (v); 1559 } 1560 1561 void 1562 put_u64(void *vp, u_int64_t v) 1563 { 1564 u_char *p = (u_char *)vp; 1565 1566 p[0] = (u_char)(v >> 56) & 0xff; 1567 p[1] = (u_char)(v >> 48) & 0xff; 1568 p[2] = (u_char)(v >> 40) & 0xff; 1569 p[3] = (u_char)(v >> 32) & 0xff; 1570 p[4] = (u_char)(v >> 24) & 0xff; 1571 p[5] = (u_char)(v >> 16) & 0xff; 1572 p[6] = (u_char)(v >> 8) & 0xff; 1573 p[7] = (u_char)v & 0xff; 1574 } 1575 1576 void 1577 put_u32(void *vp, u_int32_t v) 1578 { 1579 u_char *p = (u_char *)vp; 1580 1581 p[0] = (u_char)(v >> 24) & 0xff; 1582 p[1] = (u_char)(v >> 16) & 0xff; 1583 p[2] = (u_char)(v >> 8) & 0xff; 1584 p[3] = (u_char)v & 0xff; 1585 } 1586 1587 void 1588 put_u32_le(void *vp, u_int32_t v) 1589 { 1590 u_char *p = (u_char *)vp; 1591 1592 p[0] = (u_char)v & 0xff; 1593 p[1] = (u_char)(v >> 8) & 0xff; 1594 p[2] = (u_char)(v >> 16) & 0xff; 1595 p[3] = (u_char)(v >> 24) & 0xff; 1596 } 1597 1598 void 1599 put_u16(void *vp, u_int16_t v) 1600 { 1601 u_char *p = (u_char *)vp; 1602 1603 p[0] = (u_char)(v >> 8) & 0xff; 1604 p[1] = (u_char)v & 0xff; 1605 } 1606 1607 void 1608 ms_subtract_diff(struct timeval *start, int *ms) 1609 { 1610 struct timeval diff, finish; 1611 1612 monotime_tv(&finish); 1613 timersub(&finish, start, &diff); 1614 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1615 } 1616 1617 void 1618 ms_to_timeval(struct timeval *tv, int ms) 1619 { 1620 if (ms < 0) 1621 ms = 0; 1622 tv->tv_sec = ms / 1000; 1623 tv->tv_usec = (ms % 1000) * 1000; 1624 } 1625 1626 void 1627 monotime_ts(struct timespec *ts) 1628 { 1629 struct timeval tv; 1630 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \ 1631 defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME)) 1632 static int gettime_failed = 0; 1633 1634 if (!gettime_failed) { 1635 # ifdef CLOCK_BOOTTIME 1636 if (clock_gettime(CLOCK_BOOTTIME, ts) == 0) 1637 return; 1638 # endif /* CLOCK_BOOTTIME */ 1639 # ifdef CLOCK_MONOTONIC 1640 if (clock_gettime(CLOCK_MONOTONIC, ts) == 0) 1641 return; 1642 # endif /* CLOCK_MONOTONIC */ 1643 # ifdef CLOCK_REALTIME 1644 /* Not monotonic, but we're almost out of options here. */ 1645 if (clock_gettime(CLOCK_REALTIME, ts) == 0) 1646 return; 1647 # endif /* CLOCK_REALTIME */ 1648 debug3("clock_gettime: %s", strerror(errno)); 1649 gettime_failed = 1; 1650 } 1651 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */ 1652 gettimeofday(&tv, NULL); 1653 ts->tv_sec = tv.tv_sec; 1654 ts->tv_nsec = (long)tv.tv_usec * 1000; 1655 } 1656 1657 void 1658 monotime_tv(struct timeval *tv) 1659 { 1660 struct timespec ts; 1661 1662 monotime_ts(&ts); 1663 tv->tv_sec = ts.tv_sec; 1664 tv->tv_usec = ts.tv_nsec / 1000; 1665 } 1666 1667 time_t 1668 monotime(void) 1669 { 1670 struct timespec ts; 1671 1672 monotime_ts(&ts); 1673 return ts.tv_sec; 1674 } 1675 1676 double 1677 monotime_double(void) 1678 { 1679 struct timespec ts; 1680 1681 monotime_ts(&ts); 1682 return ts.tv_sec + ((double)ts.tv_nsec / 1000000000); 1683 } 1684 1685 void 1686 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1687 { 1688 bw->buflen = buflen; 1689 bw->rate = kbps; 1690 bw->thresh = buflen; 1691 bw->lamt = 0; 1692 timerclear(&bw->bwstart); 1693 timerclear(&bw->bwend); 1694 } 1695 1696 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1697 void 1698 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1699 { 1700 u_int64_t waitlen; 1701 struct timespec ts, rm; 1702 1703 bw->lamt += read_len; 1704 if (!timerisset(&bw->bwstart)) { 1705 monotime_tv(&bw->bwstart); 1706 return; 1707 } 1708 if (bw->lamt < bw->thresh) 1709 return; 1710 1711 monotime_tv(&bw->bwend); 1712 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1713 if (!timerisset(&bw->bwend)) 1714 return; 1715 1716 bw->lamt *= 8; 1717 waitlen = (double)1000000L * bw->lamt / bw->rate; 1718 1719 bw->bwstart.tv_sec = waitlen / 1000000L; 1720 bw->bwstart.tv_usec = waitlen % 1000000L; 1721 1722 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1723 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1724 1725 /* Adjust the wait time */ 1726 if (bw->bwend.tv_sec) { 1727 bw->thresh /= 2; 1728 if (bw->thresh < bw->buflen / 4) 1729 bw->thresh = bw->buflen / 4; 1730 } else if (bw->bwend.tv_usec < 10000) { 1731 bw->thresh *= 2; 1732 if (bw->thresh > bw->buflen * 8) 1733 bw->thresh = bw->buflen * 8; 1734 } 1735 1736 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1737 while (nanosleep(&ts, &rm) == -1) { 1738 if (errno != EINTR) 1739 break; 1740 ts = rm; 1741 } 1742 } 1743 1744 bw->lamt = 0; 1745 monotime_tv(&bw->bwstart); 1746 } 1747 1748 /* Make a template filename for mk[sd]temp() */ 1749 void 1750 mktemp_proto(char *s, size_t len) 1751 { 1752 const char *tmpdir; 1753 int r; 1754 1755 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1756 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1757 if (r > 0 && (size_t)r < len) 1758 return; 1759 } 1760 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1761 if (r < 0 || (size_t)r >= len) 1762 fatal_f("template string too short"); 1763 } 1764 1765 static const struct { 1766 const char *name; 1767 int value; 1768 } ipqos[] = { 1769 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1770 { "af11", IPTOS_DSCP_AF11 }, 1771 { "af12", IPTOS_DSCP_AF12 }, 1772 { "af13", IPTOS_DSCP_AF13 }, 1773 { "af21", IPTOS_DSCP_AF21 }, 1774 { "af22", IPTOS_DSCP_AF22 }, 1775 { "af23", IPTOS_DSCP_AF23 }, 1776 { "af31", IPTOS_DSCP_AF31 }, 1777 { "af32", IPTOS_DSCP_AF32 }, 1778 { "af33", IPTOS_DSCP_AF33 }, 1779 { "af41", IPTOS_DSCP_AF41 }, 1780 { "af42", IPTOS_DSCP_AF42 }, 1781 { "af43", IPTOS_DSCP_AF43 }, 1782 { "cs0", IPTOS_DSCP_CS0 }, 1783 { "cs1", IPTOS_DSCP_CS1 }, 1784 { "cs2", IPTOS_DSCP_CS2 }, 1785 { "cs3", IPTOS_DSCP_CS3 }, 1786 { "cs4", IPTOS_DSCP_CS4 }, 1787 { "cs5", IPTOS_DSCP_CS5 }, 1788 { "cs6", IPTOS_DSCP_CS6 }, 1789 { "cs7", IPTOS_DSCP_CS7 }, 1790 { "ef", IPTOS_DSCP_EF }, 1791 { "le", IPTOS_DSCP_LE }, 1792 { "lowdelay", IPTOS_LOWDELAY }, 1793 { "throughput", IPTOS_THROUGHPUT }, 1794 { "reliability", IPTOS_RELIABILITY }, 1795 { NULL, -1 } 1796 }; 1797 1798 int 1799 parse_ipqos(const char *cp) 1800 { 1801 u_int i; 1802 char *ep; 1803 long val; 1804 1805 if (cp == NULL) 1806 return -1; 1807 for (i = 0; ipqos[i].name != NULL; i++) { 1808 if (strcasecmp(cp, ipqos[i].name) == 0) 1809 return ipqos[i].value; 1810 } 1811 /* Try parsing as an integer */ 1812 val = strtol(cp, &ep, 0); 1813 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1814 return -1; 1815 return val; 1816 } 1817 1818 const char * 1819 iptos2str(int iptos) 1820 { 1821 int i; 1822 static char iptos_str[sizeof "0xff"]; 1823 1824 for (i = 0; ipqos[i].name != NULL; i++) { 1825 if (ipqos[i].value == iptos) 1826 return ipqos[i].name; 1827 } 1828 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1829 return iptos_str; 1830 } 1831 1832 void 1833 lowercase(char *s) 1834 { 1835 for (; *s; s++) 1836 *s = tolower((u_char)*s); 1837 } 1838 1839 int 1840 unix_listener(const char *path, int backlog, int unlink_first) 1841 { 1842 struct sockaddr_un sunaddr; 1843 int saved_errno, sock; 1844 1845 memset(&sunaddr, 0, sizeof(sunaddr)); 1846 sunaddr.sun_family = AF_UNIX; 1847 if (strlcpy(sunaddr.sun_path, path, 1848 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1849 error_f("path \"%s\" too long for Unix domain socket", path); 1850 errno = ENAMETOOLONG; 1851 return -1; 1852 } 1853 1854 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1855 if (sock == -1) { 1856 saved_errno = errno; 1857 error_f("socket: %.100s", strerror(errno)); 1858 errno = saved_errno; 1859 return -1; 1860 } 1861 if (unlink_first == 1) { 1862 if (unlink(path) != 0 && errno != ENOENT) 1863 error("unlink(%s): %.100s", path, strerror(errno)); 1864 } 1865 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1866 saved_errno = errno; 1867 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1868 close(sock); 1869 errno = saved_errno; 1870 return -1; 1871 } 1872 if (listen(sock, backlog) == -1) { 1873 saved_errno = errno; 1874 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1875 close(sock); 1876 unlink(path); 1877 errno = saved_errno; 1878 return -1; 1879 } 1880 return sock; 1881 } 1882 1883 void 1884 sock_set_v6only(int s) 1885 { 1886 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__) 1887 int on = 1; 1888 1889 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s); 1890 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) 1891 error("setsockopt IPV6_V6ONLY: %s", strerror(errno)); 1892 #endif 1893 } 1894 1895 /* 1896 * Compares two strings that maybe be NULL. Returns non-zero if strings 1897 * are both NULL or are identical, returns zero otherwise. 1898 */ 1899 static int 1900 strcmp_maybe_null(const char *a, const char *b) 1901 { 1902 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1903 return 0; 1904 if (a != NULL && strcmp(a, b) != 0) 1905 return 0; 1906 return 1; 1907 } 1908 1909 /* 1910 * Compare two forwards, returning non-zero if they are identical or 1911 * zero otherwise. 1912 */ 1913 int 1914 forward_equals(const struct Forward *a, const struct Forward *b) 1915 { 1916 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1917 return 0; 1918 if (a->listen_port != b->listen_port) 1919 return 0; 1920 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1921 return 0; 1922 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1923 return 0; 1924 if (a->connect_port != b->connect_port) 1925 return 0; 1926 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1927 return 0; 1928 /* allocated_port and handle are not checked */ 1929 return 1; 1930 } 1931 1932 /* returns 1 if process is already daemonized, 0 otherwise */ 1933 int 1934 daemonized(void) 1935 { 1936 int fd; 1937 1938 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1939 close(fd); 1940 return 0; /* have controlling terminal */ 1941 } 1942 if (getppid() != 1) 1943 return 0; /* parent is not init */ 1944 if (getsid(0) != getpid()) 1945 return 0; /* not session leader */ 1946 debug3("already daemonized"); 1947 return 1; 1948 } 1949 1950 /* 1951 * Splits 's' into an argument vector. Handles quoted string and basic 1952 * escape characters (\\, \", \'). Caller must free the argument vector 1953 * and its members. 1954 */ 1955 int 1956 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1957 { 1958 int r = SSH_ERR_INTERNAL_ERROR; 1959 int argc = 0, quote, i, j; 1960 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1961 1962 *argvp = NULL; 1963 *argcp = 0; 1964 1965 for (i = 0; s[i] != '\0'; i++) { 1966 /* Skip leading whitespace */ 1967 if (s[i] == ' ' || s[i] == '\t') 1968 continue; 1969 if (terminate_on_comment && s[i] == '#') 1970 break; 1971 /* Start of a token */ 1972 quote = 0; 1973 1974 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1975 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1976 argv[argc] = NULL; 1977 1978 /* Copy the token in, removing escapes */ 1979 for (j = 0; s[i] != '\0'; i++) { 1980 if (s[i] == '\\') { 1981 if (s[i + 1] == '\'' || 1982 s[i + 1] == '\"' || 1983 s[i + 1] == '\\' || 1984 (quote == 0 && s[i + 1] == ' ')) { 1985 i++; /* Skip '\' */ 1986 arg[j++] = s[i]; 1987 } else { 1988 /* Unrecognised escape */ 1989 arg[j++] = s[i]; 1990 } 1991 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1992 break; /* done */ 1993 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1994 quote = s[i]; /* quote start */ 1995 else if (quote != 0 && s[i] == quote) 1996 quote = 0; /* quote end */ 1997 else 1998 arg[j++] = s[i]; 1999 } 2000 if (s[i] == '\0') { 2001 if (quote != 0) { 2002 /* Ran out of string looking for close quote */ 2003 r = SSH_ERR_INVALID_FORMAT; 2004 goto out; 2005 } 2006 break; 2007 } 2008 } 2009 /* Success */ 2010 *argcp = argc; 2011 *argvp = argv; 2012 argc = 0; 2013 argv = NULL; 2014 r = 0; 2015 out: 2016 if (argc != 0 && argv != NULL) { 2017 for (i = 0; i < argc; i++) 2018 free(argv[i]); 2019 free(argv); 2020 } 2021 return r; 2022 } 2023 2024 /* 2025 * Reassemble an argument vector into a string, quoting and escaping as 2026 * necessary. Caller must free returned string. 2027 */ 2028 char * 2029 argv_assemble(int argc, char **argv) 2030 { 2031 int i, j, ws, r; 2032 char c, *ret; 2033 struct sshbuf *buf, *arg; 2034 2035 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2036 fatal_f("sshbuf_new failed"); 2037 2038 for (i = 0; i < argc; i++) { 2039 ws = 0; 2040 sshbuf_reset(arg); 2041 for (j = 0; argv[i][j] != '\0'; j++) { 2042 r = 0; 2043 c = argv[i][j]; 2044 switch (c) { 2045 case ' ': 2046 case '\t': 2047 ws = 1; 2048 r = sshbuf_put_u8(arg, c); 2049 break; 2050 case '\\': 2051 case '\'': 2052 case '"': 2053 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2054 break; 2055 /* FALLTHROUGH */ 2056 default: 2057 r = sshbuf_put_u8(arg, c); 2058 break; 2059 } 2060 if (r != 0) 2061 fatal_fr(r, "sshbuf_put_u8"); 2062 } 2063 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2064 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2065 (r = sshbuf_putb(buf, arg)) != 0 || 2066 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2067 fatal_fr(r, "assemble"); 2068 } 2069 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2070 fatal_f("malloc failed"); 2071 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2072 ret[sshbuf_len(buf)] = '\0'; 2073 sshbuf_free(buf); 2074 sshbuf_free(arg); 2075 return ret; 2076 } 2077 2078 char * 2079 argv_next(int *argcp, char ***argvp) 2080 { 2081 char *ret = (*argvp)[0]; 2082 2083 if (*argcp > 0 && ret != NULL) { 2084 (*argcp)--; 2085 (*argvp)++; 2086 } 2087 return ret; 2088 } 2089 2090 void 2091 argv_consume(int *argcp) 2092 { 2093 *argcp = 0; 2094 } 2095 2096 void 2097 argv_free(char **av, int ac) 2098 { 2099 int i; 2100 2101 if (av == NULL) 2102 return; 2103 for (i = 0; i < ac; i++) 2104 free(av[i]); 2105 free(av); 2106 } 2107 2108 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2109 int 2110 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2111 { 2112 int status; 2113 2114 while (waitpid(pid, &status, 0) == -1) { 2115 if (errno != EINTR) { 2116 error("%s waitpid: %s", tag, strerror(errno)); 2117 return -1; 2118 } 2119 } 2120 if (WIFSIGNALED(status)) { 2121 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2122 return -1; 2123 } else if (WEXITSTATUS(status) != 0) { 2124 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2125 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2126 return -1; 2127 } 2128 return 0; 2129 } 2130 2131 /* 2132 * Check a given path for security. This is defined as all components 2133 * of the path to the file must be owned by either the owner of 2134 * of the file or root and no directories must be group or world writable. 2135 * 2136 * XXX Should any specific check be done for sym links ? 2137 * 2138 * Takes a file name, its stat information (preferably from fstat() to 2139 * avoid races), the uid of the expected owner, their home directory and an 2140 * error buffer plus max size as arguments. 2141 * 2142 * Returns 0 on success and -1 on failure 2143 */ 2144 int 2145 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2146 uid_t uid, char *err, size_t errlen) 2147 { 2148 char buf[PATH_MAX], homedir[PATH_MAX]; 2149 char *cp; 2150 int comparehome = 0; 2151 struct stat st; 2152 2153 if (realpath(name, buf) == NULL) { 2154 snprintf(err, errlen, "realpath %s failed: %s", name, 2155 strerror(errno)); 2156 return -1; 2157 } 2158 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2159 comparehome = 1; 2160 2161 if (!S_ISREG(stp->st_mode)) { 2162 snprintf(err, errlen, "%s is not a regular file", buf); 2163 return -1; 2164 } 2165 if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || 2166 (stp->st_mode & 022) != 0) { 2167 snprintf(err, errlen, "bad ownership or modes for file %s", 2168 buf); 2169 return -1; 2170 } 2171 2172 /* for each component of the canonical path, walking upwards */ 2173 for (;;) { 2174 if ((cp = dirname(buf)) == NULL) { 2175 snprintf(err, errlen, "dirname() failed"); 2176 return -1; 2177 } 2178 strlcpy(buf, cp, sizeof(buf)); 2179 2180 if (stat(buf, &st) == -1 || 2181 (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || 2182 (st.st_mode & 022) != 0) { 2183 snprintf(err, errlen, 2184 "bad ownership or modes for directory %s", buf); 2185 return -1; 2186 } 2187 2188 /* If are past the homedir then we can stop */ 2189 if (comparehome && strcmp(homedir, buf) == 0) 2190 break; 2191 2192 /* 2193 * dirname should always complete with a "/" path, 2194 * but we can be paranoid and check for "." too 2195 */ 2196 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2197 break; 2198 } 2199 return 0; 2200 } 2201 2202 /* 2203 * Version of safe_path() that accepts an open file descriptor to 2204 * avoid races. 2205 * 2206 * Returns 0 on success and -1 on failure 2207 */ 2208 int 2209 safe_path_fd(int fd, const char *file, struct passwd *pw, 2210 char *err, size_t errlen) 2211 { 2212 struct stat st; 2213 2214 /* check the open file to avoid races */ 2215 if (fstat(fd, &st) == -1) { 2216 snprintf(err, errlen, "cannot stat file %s: %s", 2217 file, strerror(errno)); 2218 return -1; 2219 } 2220 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2221 } 2222 2223 /* 2224 * Sets the value of the given variable in the environment. If the variable 2225 * already exists, its value is overridden. 2226 */ 2227 void 2228 child_set_env(char ***envp, u_int *envsizep, const char *name, 2229 const char *value) 2230 { 2231 char **env; 2232 u_int envsize; 2233 u_int i, namelen; 2234 2235 if (strchr(name, '=') != NULL) { 2236 error("Invalid environment variable \"%.100s\"", name); 2237 return; 2238 } 2239 2240 /* 2241 * If we're passed an uninitialized list, allocate a single null 2242 * entry before continuing. 2243 */ 2244 if (*envp == NULL && *envsizep == 0) { 2245 *envp = xmalloc(sizeof(char *)); 2246 *envp[0] = NULL; 2247 *envsizep = 1; 2248 } 2249 2250 /* 2251 * Find the slot where the value should be stored. If the variable 2252 * already exists, we reuse the slot; otherwise we append a new slot 2253 * at the end of the array, expanding if necessary. 2254 */ 2255 env = *envp; 2256 namelen = strlen(name); 2257 for (i = 0; env[i]; i++) 2258 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2259 break; 2260 if (env[i]) { 2261 /* Reuse the slot. */ 2262 free(env[i]); 2263 } else { 2264 /* New variable. Expand if necessary. */ 2265 envsize = *envsizep; 2266 if (i >= envsize - 1) { 2267 if (envsize >= 1000) 2268 fatal("child_set_env: too many env vars"); 2269 envsize += 50; 2270 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2271 *envsizep = envsize; 2272 } 2273 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2274 env[i + 1] = NULL; 2275 } 2276 2277 /* Allocate space and format the variable in the appropriate slot. */ 2278 /* XXX xasprintf */ 2279 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2280 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2281 } 2282 2283 /* 2284 * Check and optionally lowercase a domain name, also removes trailing '.' 2285 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2286 */ 2287 int 2288 valid_domain(char *name, int makelower, const char **errstr) 2289 { 2290 size_t i, l = strlen(name); 2291 u_char c, last = '\0'; 2292 static char errbuf[256]; 2293 2294 if (l == 0) { 2295 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2296 goto bad; 2297 } 2298 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2299 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2300 "starts with invalid character", name); 2301 goto bad; 2302 } 2303 for (i = 0; i < l; i++) { 2304 c = tolower((u_char)name[i]); 2305 if (makelower) 2306 name[i] = (char)c; 2307 if (last == '.' && c == '.') { 2308 snprintf(errbuf, sizeof(errbuf), "domain name " 2309 "\"%.100s\" contains consecutive separators", name); 2310 goto bad; 2311 } 2312 if (c != '.' && c != '-' && !isalnum(c) && 2313 c != '_') /* technically invalid, but common */ { 2314 snprintf(errbuf, sizeof(errbuf), "domain name " 2315 "\"%.100s\" contains invalid characters", name); 2316 goto bad; 2317 } 2318 last = c; 2319 } 2320 if (name[l - 1] == '.') 2321 name[l - 1] = '\0'; 2322 if (errstr != NULL) 2323 *errstr = NULL; 2324 return 1; 2325 bad: 2326 if (errstr != NULL) 2327 *errstr = errbuf; 2328 return 0; 2329 } 2330 2331 /* 2332 * Verify that a environment variable name (not including initial '$') is 2333 * valid; consisting of one or more alphanumeric or underscore characters only. 2334 * Returns 1 on valid, 0 otherwise. 2335 */ 2336 int 2337 valid_env_name(const char *name) 2338 { 2339 const char *cp; 2340 2341 if (name[0] == '\0') 2342 return 0; 2343 for (cp = name; *cp != '\0'; cp++) { 2344 if (!isalnum((u_char)*cp) && *cp != '_') 2345 return 0; 2346 } 2347 return 1; 2348 } 2349 2350 const char * 2351 atoi_err(const char *nptr, int *val) 2352 { 2353 const char *errstr = NULL; 2354 long long num; 2355 2356 if (nptr == NULL || *nptr == '\0') 2357 return "missing"; 2358 num = strtonum(nptr, 0, INT_MAX, &errstr); 2359 if (errstr == NULL) 2360 *val = (int)num; 2361 return errstr; 2362 } 2363 2364 int 2365 parse_absolute_time(const char *s, uint64_t *tp) 2366 { 2367 struct tm tm; 2368 time_t tt; 2369 char buf[32], *fmt; 2370 2371 *tp = 0; 2372 2373 /* 2374 * POSIX strptime says "The application shall ensure that there 2375 * is white-space or other non-alphanumeric characters between 2376 * any two conversion specifications" so arrange things this way. 2377 */ 2378 switch (strlen(s)) { 2379 case 8: /* YYYYMMDD */ 2380 fmt = "%Y-%m-%d"; 2381 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2382 break; 2383 case 12: /* YYYYMMDDHHMM */ 2384 fmt = "%Y-%m-%dT%H:%M"; 2385 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2386 s, s + 4, s + 6, s + 8, s + 10); 2387 break; 2388 case 14: /* YYYYMMDDHHMMSS */ 2389 fmt = "%Y-%m-%dT%H:%M:%S"; 2390 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2391 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2392 break; 2393 default: 2394 return SSH_ERR_INVALID_FORMAT; 2395 } 2396 2397 memset(&tm, 0, sizeof(tm)); 2398 if (strptime(buf, fmt, &tm) == NULL) 2399 return SSH_ERR_INVALID_FORMAT; 2400 if ((tt = mktime(&tm)) < 0) 2401 return SSH_ERR_INVALID_FORMAT; 2402 /* success */ 2403 *tp = (uint64_t)tt; 2404 return 0; 2405 } 2406 2407 /* On OpenBSD time_t is int64_t which is long long. */ 2408 /* #define SSH_TIME_T_MAX LLONG_MAX */ 2409 2410 void 2411 format_absolute_time(uint64_t t, char *buf, size_t len) 2412 { 2413 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2414 struct tm tm; 2415 2416 localtime_r(&tt, &tm); 2417 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2418 } 2419 2420 /* check if path is absolute */ 2421 int 2422 path_absolute(const char *path) 2423 { 2424 return (*path == '/') ? 1 : 0; 2425 } 2426 2427 void 2428 skip_space(char **cpp) 2429 { 2430 char *cp; 2431 2432 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2433 ; 2434 *cpp = cp; 2435 } 2436 2437 /* authorized_key-style options parsing helpers */ 2438 2439 /* 2440 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2441 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2442 * if negated option matches. 2443 * If the option or negated option matches, then *optsp is updated to 2444 * point to the first character after the option. 2445 */ 2446 int 2447 opt_flag(const char *opt, int allow_negate, const char **optsp) 2448 { 2449 size_t opt_len = strlen(opt); 2450 const char *opts = *optsp; 2451 int negate = 0; 2452 2453 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2454 opts += 3; 2455 negate = 1; 2456 } 2457 if (strncasecmp(opts, opt, opt_len) == 0) { 2458 *optsp = opts + opt_len; 2459 return negate ? 0 : 1; 2460 } 2461 return -1; 2462 } 2463 2464 char * 2465 opt_dequote(const char **sp, const char **errstrp) 2466 { 2467 const char *s = *sp; 2468 char *ret; 2469 size_t i; 2470 2471 *errstrp = NULL; 2472 if (*s != '"') { 2473 *errstrp = "missing start quote"; 2474 return NULL; 2475 } 2476 s++; 2477 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2478 *errstrp = "memory allocation failed"; 2479 return NULL; 2480 } 2481 for (i = 0; *s != '\0' && *s != '"';) { 2482 if (s[0] == '\\' && s[1] == '"') 2483 s++; 2484 ret[i++] = *s++; 2485 } 2486 if (*s == '\0') { 2487 *errstrp = "missing end quote"; 2488 free(ret); 2489 return NULL; 2490 } 2491 ret[i] = '\0'; 2492 s++; 2493 *sp = s; 2494 return ret; 2495 } 2496 2497 int 2498 opt_match(const char **opts, const char *term) 2499 { 2500 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2501 (*opts)[strlen(term)] == '=') { 2502 *opts += strlen(term) + 1; 2503 return 1; 2504 } 2505 return 0; 2506 } 2507 2508 void 2509 opt_array_append2(const char *file, const int line, const char *directive, 2510 char ***array, int **iarray, u_int *lp, const char *s, int i) 2511 { 2512 2513 if (*lp >= INT_MAX) 2514 fatal("%s line %d: Too many %s entries", file, line, directive); 2515 2516 if (iarray != NULL) { 2517 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2518 sizeof(**iarray)); 2519 (*iarray)[*lp] = i; 2520 } 2521 2522 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2523 (*array)[*lp] = xstrdup(s); 2524 (*lp)++; 2525 } 2526 2527 void 2528 opt_array_append(const char *file, const int line, const char *directive, 2529 char ***array, u_int *lp, const char *s) 2530 { 2531 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2532 } 2533 2534 sshsig_t 2535 ssh_signal(int signum, sshsig_t handler) 2536 { 2537 struct sigaction sa, osa; 2538 2539 /* mask all other signals while in handler */ 2540 memset(&sa, 0, sizeof(sa)); 2541 sa.sa_handler = handler; 2542 sigfillset(&sa.sa_mask); 2543 #if defined(SA_RESTART) && !defined(NO_SA_RESTART) 2544 if (signum != SIGALRM) 2545 sa.sa_flags = SA_RESTART; 2546 #endif 2547 if (sigaction(signum, &sa, &osa) == -1) { 2548 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2549 return SIG_ERR; 2550 } 2551 return osa.sa_handler; 2552 } 2553 2554 int 2555 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2556 { 2557 int devnull, ret = 0; 2558 2559 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2560 error_f("open %s: %s", _PATH_DEVNULL, 2561 strerror(errno)); 2562 return -1; 2563 } 2564 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2565 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2566 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2567 error_f("dup2: %s", strerror(errno)); 2568 ret = -1; 2569 } 2570 if (devnull > STDERR_FILENO) 2571 close(devnull); 2572 return ret; 2573 } 2574 2575 /* 2576 * Runs command in a subprocess with a minimal environment. 2577 * Returns pid on success, 0 on failure. 2578 * The child stdout and stderr maybe captured, left attached or sent to 2579 * /dev/null depending on the contents of flags. 2580 * "tag" is prepended to log messages. 2581 * NB. "command" is only used for logging; the actual command executed is 2582 * av[0]. 2583 */ 2584 pid_t 2585 subprocess(const char *tag, const char *command, 2586 int ac, char **av, FILE **child, u_int flags, 2587 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2588 { 2589 FILE *f = NULL; 2590 struct stat st; 2591 int fd, devnull, p[2], i; 2592 pid_t pid; 2593 char *cp, errmsg[512]; 2594 u_int nenv = 0; 2595 char **env = NULL; 2596 2597 /* If dropping privs, then must specify user and restore function */ 2598 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2599 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2600 return 0; 2601 } 2602 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2603 error("%s: no user for current uid", tag); 2604 return 0; 2605 } 2606 if (child != NULL) 2607 *child = NULL; 2608 2609 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2610 tag, command, pw->pw_name, flags); 2611 2612 /* Check consistency */ 2613 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2614 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2615 error_f("inconsistent flags"); 2616 return 0; 2617 } 2618 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2619 error_f("inconsistent flags/output"); 2620 return 0; 2621 } 2622 2623 /* 2624 * If executing an explicit binary, then verify the it exists 2625 * and appears safe-ish to execute 2626 */ 2627 if (!path_absolute(av[0])) { 2628 error("%s path is not absolute", tag); 2629 return 0; 2630 } 2631 if (drop_privs != NULL) 2632 drop_privs(pw); 2633 if (stat(av[0], &st) == -1) { 2634 error("Could not stat %s \"%s\": %s", tag, 2635 av[0], strerror(errno)); 2636 goto restore_return; 2637 } 2638 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2639 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2640 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2641 goto restore_return; 2642 } 2643 /* Prepare to keep the child's stdout if requested */ 2644 if (pipe(p) == -1) { 2645 error("%s: pipe: %s", tag, strerror(errno)); 2646 restore_return: 2647 if (restore_privs != NULL) 2648 restore_privs(); 2649 return 0; 2650 } 2651 if (restore_privs != NULL) 2652 restore_privs(); 2653 2654 switch ((pid = fork())) { 2655 case -1: /* error */ 2656 error("%s: fork: %s", tag, strerror(errno)); 2657 close(p[0]); 2658 close(p[1]); 2659 return 0; 2660 case 0: /* child */ 2661 /* Prepare a minimal environment for the child. */ 2662 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2663 nenv = 5; 2664 env = xcalloc(sizeof(*env), nenv); 2665 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2666 child_set_env(&env, &nenv, "USER", pw->pw_name); 2667 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2668 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2669 if ((cp = getenv("LANG")) != NULL) 2670 child_set_env(&env, &nenv, "LANG", cp); 2671 } 2672 2673 for (i = 1; i < NSIG; i++) 2674 ssh_signal(i, SIG_DFL); 2675 2676 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2677 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2678 strerror(errno)); 2679 _exit(1); 2680 } 2681 if (dup2(devnull, STDIN_FILENO) == -1) { 2682 error("%s: dup2: %s", tag, strerror(errno)); 2683 _exit(1); 2684 } 2685 2686 /* Set up stdout as requested; leave stderr in place for now. */ 2687 fd = -1; 2688 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2689 fd = p[1]; 2690 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2691 fd = devnull; 2692 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2693 error("%s: dup2: %s", tag, strerror(errno)); 2694 _exit(1); 2695 } 2696 closefrom(STDERR_FILENO + 1); 2697 2698 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2699 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2700 strerror(errno)); 2701 _exit(1); 2702 } 2703 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2704 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2705 strerror(errno)); 2706 _exit(1); 2707 } 2708 /* stdin is pointed to /dev/null at this point */ 2709 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2710 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2711 error("%s: dup2: %s", tag, strerror(errno)); 2712 _exit(1); 2713 } 2714 if (env != NULL) 2715 execve(av[0], av, env); 2716 else 2717 execv(av[0], av); 2718 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2719 command, strerror(errno)); 2720 _exit(127); 2721 default: /* parent */ 2722 break; 2723 } 2724 2725 close(p[1]); 2726 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2727 close(p[0]); 2728 else if ((f = fdopen(p[0], "r")) == NULL) { 2729 error("%s: fdopen: %s", tag, strerror(errno)); 2730 close(p[0]); 2731 /* Don't leave zombie child */ 2732 kill(pid, SIGTERM); 2733 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2734 ; 2735 return 0; 2736 } 2737 /* Success */ 2738 debug3_f("%s pid %ld", tag, (long)pid); 2739 if (child != NULL) 2740 *child = f; 2741 return pid; 2742 } 2743 2744 const char * 2745 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2746 { 2747 size_t i, envlen; 2748 2749 envlen = strlen(env); 2750 for (i = 0; i < nenvs; i++) { 2751 if (strncmp(envs[i], env, envlen) == 0 && 2752 envs[i][envlen] == '=') { 2753 return envs[i] + envlen + 1; 2754 } 2755 } 2756 return NULL; 2757 } 2758