1 /* $OpenBSD: misc.c,v 1.170 2021/09/26 14:01:03 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 #include <grp.h> 60 #endif 61 #ifdef SSH_TUN_OPENBSD 62 #include <net/if.h> 63 #endif 64 65 #include "xmalloc.h" 66 #include "misc.h" 67 #include "log.h" 68 #include "ssh.h" 69 #include "sshbuf.h" 70 #include "ssherr.h" 71 #include "platform.h" 72 73 /* remove newline at end of string */ 74 char * 75 chop(char *s) 76 { 77 char *t = s; 78 while (*t) { 79 if (*t == '\n' || *t == '\r') { 80 *t = '\0'; 81 return s; 82 } 83 t++; 84 } 85 return s; 86 87 } 88 89 /* remove whitespace from end of string */ 90 void 91 rtrim(char *s) 92 { 93 size_t i; 94 95 if ((i = strlen(s)) == 0) 96 return; 97 for (i--; i > 0; i--) { 98 if (isspace((int)s[i])) 99 s[i] = '\0'; 100 } 101 } 102 103 /* set/unset filedescriptor to non-blocking */ 104 int 105 set_nonblock(int fd) 106 { 107 int val; 108 109 val = fcntl(fd, F_GETFL); 110 if (val == -1) { 111 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 112 return (-1); 113 } 114 if (val & O_NONBLOCK) { 115 debug3("fd %d is O_NONBLOCK", fd); 116 return (0); 117 } 118 debug2("fd %d setting O_NONBLOCK", fd); 119 val |= O_NONBLOCK; 120 if (fcntl(fd, F_SETFL, val) == -1) { 121 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 122 strerror(errno)); 123 return (-1); 124 } 125 return (0); 126 } 127 128 int 129 unset_nonblock(int fd) 130 { 131 int val; 132 133 val = fcntl(fd, F_GETFL); 134 if (val == -1) { 135 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 136 return (-1); 137 } 138 if (!(val & O_NONBLOCK)) { 139 debug3("fd %d is not O_NONBLOCK", fd); 140 return (0); 141 } 142 debug("fd %d clearing O_NONBLOCK", fd); 143 val &= ~O_NONBLOCK; 144 if (fcntl(fd, F_SETFL, val) == -1) { 145 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 146 fd, strerror(errno)); 147 return (-1); 148 } 149 return (0); 150 } 151 152 const char * 153 ssh_gai_strerror(int gaierr) 154 { 155 if (gaierr == EAI_SYSTEM && errno != 0) 156 return strerror(errno); 157 return gai_strerror(gaierr); 158 } 159 160 /* disable nagle on socket */ 161 void 162 set_nodelay(int fd) 163 { 164 int opt; 165 socklen_t optlen; 166 167 optlen = sizeof opt; 168 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 169 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 170 return; 171 } 172 if (opt == 1) { 173 debug2("fd %d is TCP_NODELAY", fd); 174 return; 175 } 176 opt = 1; 177 debug2("fd %d setting TCP_NODELAY", fd); 178 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 179 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 180 } 181 182 /* Allow local port reuse in TIME_WAIT */ 183 int 184 set_reuseaddr(int fd) 185 { 186 int on = 1; 187 188 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 189 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 190 return -1; 191 } 192 return 0; 193 } 194 195 /* Get/set routing domain */ 196 char * 197 get_rdomain(int fd) 198 { 199 #if defined(HAVE_SYS_GET_RDOMAIN) 200 return sys_get_rdomain(fd); 201 #elif defined(__OpenBSD__) 202 int rtable; 203 char *ret; 204 socklen_t len = sizeof(rtable); 205 206 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 207 error("Failed to get routing domain for fd %d: %s", 208 fd, strerror(errno)); 209 return NULL; 210 } 211 xasprintf(&ret, "%d", rtable); 212 return ret; 213 #else /* defined(__OpenBSD__) */ 214 return NULL; 215 #endif 216 } 217 218 int 219 set_rdomain(int fd, const char *name) 220 { 221 #if defined(HAVE_SYS_SET_RDOMAIN) 222 return sys_set_rdomain(fd, name); 223 #elif defined(__OpenBSD__) 224 int rtable; 225 const char *errstr; 226 227 if (name == NULL) 228 return 0; /* default table */ 229 230 rtable = (int)strtonum(name, 0, 255, &errstr); 231 if (errstr != NULL) { 232 /* Shouldn't happen */ 233 error("Invalid routing domain \"%s\": %s", name, errstr); 234 return -1; 235 } 236 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 237 &rtable, sizeof(rtable)) == -1) { 238 error("Failed to set routing domain %d on fd %d: %s", 239 rtable, fd, strerror(errno)); 240 return -1; 241 } 242 return 0; 243 #else /* defined(__OpenBSD__) */ 244 error("Setting routing domain is not supported on this platform"); 245 return -1; 246 #endif 247 } 248 249 int 250 get_sock_af(int fd) 251 { 252 struct sockaddr_storage to; 253 socklen_t tolen = sizeof(to); 254 255 memset(&to, 0, sizeof(to)); 256 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 257 return -1; 258 #ifdef IPV4_IN_IPV6 259 if (to.ss_family == AF_INET6 && 260 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) 261 return AF_INET; 262 #endif 263 return to.ss_family; 264 } 265 266 void 267 set_sock_tos(int fd, int tos) 268 { 269 #ifndef IP_TOS_IS_BROKEN 270 int af; 271 272 switch ((af = get_sock_af(fd))) { 273 case -1: 274 /* assume not a socket */ 275 break; 276 case AF_INET: 277 # ifdef IP_TOS 278 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 279 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 280 &tos, sizeof(tos)) == -1) { 281 error("setsockopt socket %d IP_TOS %d: %s:", 282 fd, tos, strerror(errno)); 283 } 284 # endif /* IP_TOS */ 285 break; 286 case AF_INET6: 287 # ifdef IPV6_TCLASS 288 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 289 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 290 &tos, sizeof(tos)) == -1) { 291 error("setsockopt socket %d IPV6_TCLASS %d: %.100s:", 292 fd, tos, strerror(errno)); 293 } 294 # endif /* IPV6_TCLASS */ 295 break; 296 default: 297 debug2_f("unsupported socket family %d", af); 298 break; 299 } 300 #endif /* IP_TOS_IS_BROKEN */ 301 } 302 303 /* 304 * Wait up to *timeoutp milliseconds for events on fd. Updates 305 * *timeoutp with time remaining. 306 * Returns 0 if fd ready or -1 on timeout or error (see errno). 307 */ 308 static int 309 waitfd(int fd, int *timeoutp, short events) 310 { 311 struct pollfd pfd; 312 struct timeval t_start; 313 int oerrno, r; 314 315 pfd.fd = fd; 316 pfd.events = events; 317 for (; *timeoutp >= 0;) { 318 monotime_tv(&t_start); 319 r = poll(&pfd, 1, *timeoutp); 320 oerrno = errno; 321 ms_subtract_diff(&t_start, timeoutp); 322 errno = oerrno; 323 if (r > 0) 324 return 0; 325 else if (r == -1 && errno != EAGAIN && errno != EINTR) 326 return -1; 327 else if (r == 0) 328 break; 329 } 330 /* timeout */ 331 errno = ETIMEDOUT; 332 return -1; 333 } 334 335 /* 336 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 337 * *timeoutp with time remaining. 338 * Returns 0 if fd ready or -1 on timeout or error (see errno). 339 */ 340 int 341 waitrfd(int fd, int *timeoutp) { 342 return waitfd(fd, timeoutp, POLLIN); 343 } 344 345 /* 346 * Attempt a non-blocking connect(2) to the specified address, waiting up to 347 * *timeoutp milliseconds for the connection to complete. If the timeout is 348 * <=0, then wait indefinitely. 349 * 350 * Returns 0 on success or -1 on failure. 351 */ 352 int 353 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 354 socklen_t addrlen, int *timeoutp) 355 { 356 int optval = 0; 357 socklen_t optlen = sizeof(optval); 358 359 /* No timeout: just do a blocking connect() */ 360 if (timeoutp == NULL || *timeoutp <= 0) 361 return connect(sockfd, serv_addr, addrlen); 362 363 set_nonblock(sockfd); 364 for (;;) { 365 if (connect(sockfd, serv_addr, addrlen) == 0) { 366 /* Succeeded already? */ 367 unset_nonblock(sockfd); 368 return 0; 369 } else if (errno == EINTR) 370 continue; 371 else if (errno != EINPROGRESS) 372 return -1; 373 break; 374 } 375 376 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) 377 return -1; 378 379 /* Completed or failed */ 380 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 381 debug("getsockopt: %s", strerror(errno)); 382 return -1; 383 } 384 if (optval != 0) { 385 errno = optval; 386 return -1; 387 } 388 unset_nonblock(sockfd); 389 return 0; 390 } 391 392 /* Characters considered whitespace in strsep calls. */ 393 #define WHITESPACE " \t\r\n" 394 #define QUOTE "\"" 395 396 /* return next token in configuration line */ 397 static char * 398 strdelim_internal(char **s, int split_equals) 399 { 400 char *old; 401 int wspace = 0; 402 403 if (*s == NULL) 404 return NULL; 405 406 old = *s; 407 408 *s = strpbrk(*s, 409 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 410 if (*s == NULL) 411 return (old); 412 413 if (*s[0] == '\"') { 414 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 415 /* Find matching quote */ 416 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 417 return (NULL); /* no matching quote */ 418 } else { 419 *s[0] = '\0'; 420 *s += strspn(*s + 1, WHITESPACE) + 1; 421 return (old); 422 } 423 } 424 425 /* Allow only one '=' to be skipped */ 426 if (split_equals && *s[0] == '=') 427 wspace = 1; 428 *s[0] = '\0'; 429 430 /* Skip any extra whitespace after first token */ 431 *s += strspn(*s + 1, WHITESPACE) + 1; 432 if (split_equals && *s[0] == '=' && !wspace) 433 *s += strspn(*s + 1, WHITESPACE) + 1; 434 435 return (old); 436 } 437 438 /* 439 * Return next token in configuration line; splts on whitespace or a 440 * single '=' character. 441 */ 442 char * 443 strdelim(char **s) 444 { 445 return strdelim_internal(s, 1); 446 } 447 448 /* 449 * Return next token in configuration line; splts on whitespace only. 450 */ 451 char * 452 strdelimw(char **s) 453 { 454 return strdelim_internal(s, 0); 455 } 456 457 struct passwd * 458 pwcopy(struct passwd *pw) 459 { 460 struct passwd *copy = xcalloc(1, sizeof(*copy)); 461 462 copy->pw_name = xstrdup(pw->pw_name); 463 copy->pw_passwd = xstrdup(pw->pw_passwd == NULL ? "*" : pw->pw_passwd); 464 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 465 copy->pw_gecos = xstrdup(pw->pw_gecos); 466 #endif 467 copy->pw_uid = pw->pw_uid; 468 copy->pw_gid = pw->pw_gid; 469 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE 470 copy->pw_expire = pw->pw_expire; 471 #endif 472 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE 473 copy->pw_change = pw->pw_change; 474 #endif 475 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 476 copy->pw_class = xstrdup(pw->pw_class); 477 #endif 478 copy->pw_dir = xstrdup(pw->pw_dir); 479 copy->pw_shell = xstrdup(pw->pw_shell); 480 return copy; 481 } 482 483 /* 484 * Convert ASCII string to TCP/IP port number. 485 * Port must be >=0 and <=65535. 486 * Return -1 if invalid. 487 */ 488 int 489 a2port(const char *s) 490 { 491 struct servent *se; 492 long long port; 493 const char *errstr; 494 495 port = strtonum(s, 0, 65535, &errstr); 496 if (errstr == NULL) 497 return (int)port; 498 if ((se = getservbyname(s, "tcp")) != NULL) 499 return ntohs(se->s_port); 500 return -1; 501 } 502 503 int 504 a2tun(const char *s, int *remote) 505 { 506 const char *errstr = NULL; 507 char *sp, *ep; 508 int tun; 509 510 if (remote != NULL) { 511 *remote = SSH_TUNID_ANY; 512 sp = xstrdup(s); 513 if ((ep = strchr(sp, ':')) == NULL) { 514 free(sp); 515 return (a2tun(s, NULL)); 516 } 517 ep[0] = '\0'; ep++; 518 *remote = a2tun(ep, NULL); 519 tun = a2tun(sp, NULL); 520 free(sp); 521 return (*remote == SSH_TUNID_ERR ? *remote : tun); 522 } 523 524 if (strcasecmp(s, "any") == 0) 525 return (SSH_TUNID_ANY); 526 527 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 528 if (errstr != NULL) 529 return (SSH_TUNID_ERR); 530 531 return (tun); 532 } 533 534 #define SECONDS 1 535 #define MINUTES (SECONDS * 60) 536 #define HOURS (MINUTES * 60) 537 #define DAYS (HOURS * 24) 538 #define WEEKS (DAYS * 7) 539 540 /* 541 * Convert a time string into seconds; format is 542 * a sequence of: 543 * time[qualifier] 544 * 545 * Valid time qualifiers are: 546 * <none> seconds 547 * s|S seconds 548 * m|M minutes 549 * h|H hours 550 * d|D days 551 * w|W weeks 552 * 553 * Examples: 554 * 90m 90 minutes 555 * 1h30m 90 minutes 556 * 2d 2 days 557 * 1w 1 week 558 * 559 * Return -1 if time string is invalid. 560 */ 561 int 562 convtime(const char *s) 563 { 564 long total, secs, multiplier; 565 const char *p; 566 char *endp; 567 568 errno = 0; 569 total = 0; 570 p = s; 571 572 if (p == NULL || *p == '\0') 573 return -1; 574 575 while (*p) { 576 secs = strtol(p, &endp, 10); 577 if (p == endp || 578 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 579 secs < 0) 580 return -1; 581 582 multiplier = 1; 583 switch (*endp++) { 584 case '\0': 585 endp--; 586 break; 587 case 's': 588 case 'S': 589 break; 590 case 'm': 591 case 'M': 592 multiplier = MINUTES; 593 break; 594 case 'h': 595 case 'H': 596 multiplier = HOURS; 597 break; 598 case 'd': 599 case 'D': 600 multiplier = DAYS; 601 break; 602 case 'w': 603 case 'W': 604 multiplier = WEEKS; 605 break; 606 default: 607 return -1; 608 } 609 if (secs > INT_MAX / multiplier) 610 return -1; 611 secs *= multiplier; 612 if (total > INT_MAX - secs) 613 return -1; 614 total += secs; 615 if (total < 0) 616 return -1; 617 p = endp; 618 } 619 620 return total; 621 } 622 623 #define TF_BUFS 8 624 #define TF_LEN 9 625 626 const char * 627 fmt_timeframe(time_t t) 628 { 629 char *buf; 630 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 631 static int idx = 0; 632 unsigned int sec, min, hrs, day; 633 unsigned long long week; 634 635 buf = tfbuf[idx++]; 636 if (idx == TF_BUFS) 637 idx = 0; 638 639 week = t; 640 641 sec = week % 60; 642 week /= 60; 643 min = week % 60; 644 week /= 60; 645 hrs = week % 24; 646 week /= 24; 647 day = week % 7; 648 week /= 7; 649 650 if (week > 0) 651 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 652 else if (day > 0) 653 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 654 else 655 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 656 657 return (buf); 658 } 659 660 /* 661 * Returns a standardized host+port identifier string. 662 * Caller must free returned string. 663 */ 664 char * 665 put_host_port(const char *host, u_short port) 666 { 667 char *hoststr; 668 669 if (port == 0 || port == SSH_DEFAULT_PORT) 670 return(xstrdup(host)); 671 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 672 fatal("put_host_port: asprintf: %s", strerror(errno)); 673 debug3("put_host_port: %s", hoststr); 674 return hoststr; 675 } 676 677 /* 678 * Search for next delimiter between hostnames/addresses and ports. 679 * Argument may be modified (for termination). 680 * Returns *cp if parsing succeeds. 681 * *cp is set to the start of the next field, if one was found. 682 * The delimiter char, if present, is stored in delim. 683 * If this is the last field, *cp is set to NULL. 684 */ 685 char * 686 hpdelim2(char **cp, char *delim) 687 { 688 char *s, *old; 689 690 if (cp == NULL || *cp == NULL) 691 return NULL; 692 693 old = s = *cp; 694 if (*s == '[') { 695 if ((s = strchr(s, ']')) == NULL) 696 return NULL; 697 else 698 s++; 699 } else if ((s = strpbrk(s, ":/")) == NULL) 700 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 701 702 switch (*s) { 703 case '\0': 704 *cp = NULL; /* no more fields*/ 705 break; 706 707 case ':': 708 case '/': 709 if (delim != NULL) 710 *delim = *s; 711 *s = '\0'; /* terminate */ 712 *cp = s + 1; 713 break; 714 715 default: 716 return NULL; 717 } 718 719 return old; 720 } 721 722 char * 723 hpdelim(char **cp) 724 { 725 return hpdelim2(cp, NULL); 726 } 727 728 char * 729 cleanhostname(char *host) 730 { 731 if (*host == '[' && host[strlen(host) - 1] == ']') { 732 host[strlen(host) - 1] = '\0'; 733 return (host + 1); 734 } else 735 return host; 736 } 737 738 char * 739 colon(char *cp) 740 { 741 int flag = 0; 742 743 if (*cp == ':') /* Leading colon is part of file name. */ 744 return NULL; 745 if (*cp == '[') 746 flag = 1; 747 748 for (; *cp; ++cp) { 749 if (*cp == '@' && *(cp+1) == '[') 750 flag = 1; 751 if (*cp == ']' && *(cp+1) == ':' && flag) 752 return (cp+1); 753 if (*cp == ':' && !flag) 754 return (cp); 755 if (*cp == '/') 756 return NULL; 757 } 758 return NULL; 759 } 760 761 /* 762 * Parse a [user@]host:[path] string. 763 * Caller must free returned user, host and path. 764 * Any of the pointer return arguments may be NULL (useful for syntax checking). 765 * If user was not specified then *userp will be set to NULL. 766 * If host was not specified then *hostp will be set to NULL. 767 * If path was not specified then *pathp will be set to ".". 768 * Returns 0 on success, -1 on failure. 769 */ 770 int 771 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 772 { 773 char *user = NULL, *host = NULL, *path = NULL; 774 char *sdup, *tmp; 775 int ret = -1; 776 777 if (userp != NULL) 778 *userp = NULL; 779 if (hostp != NULL) 780 *hostp = NULL; 781 if (pathp != NULL) 782 *pathp = NULL; 783 784 sdup = xstrdup(s); 785 786 /* Check for remote syntax: [user@]host:[path] */ 787 if ((tmp = colon(sdup)) == NULL) 788 goto out; 789 790 /* Extract optional path */ 791 *tmp++ = '\0'; 792 if (*tmp == '\0') 793 tmp = "."; 794 path = xstrdup(tmp); 795 796 /* Extract optional user and mandatory host */ 797 tmp = strrchr(sdup, '@'); 798 if (tmp != NULL) { 799 *tmp++ = '\0'; 800 host = xstrdup(cleanhostname(tmp)); 801 if (*sdup != '\0') 802 user = xstrdup(sdup); 803 } else { 804 host = xstrdup(cleanhostname(sdup)); 805 user = NULL; 806 } 807 808 /* Success */ 809 if (userp != NULL) { 810 *userp = user; 811 user = NULL; 812 } 813 if (hostp != NULL) { 814 *hostp = host; 815 host = NULL; 816 } 817 if (pathp != NULL) { 818 *pathp = path; 819 path = NULL; 820 } 821 ret = 0; 822 out: 823 free(sdup); 824 free(user); 825 free(host); 826 free(path); 827 return ret; 828 } 829 830 /* 831 * Parse a [user@]host[:port] string. 832 * Caller must free returned user and host. 833 * Any of the pointer return arguments may be NULL (useful for syntax checking). 834 * If user was not specified then *userp will be set to NULL. 835 * If port was not specified then *portp will be -1. 836 * Returns 0 on success, -1 on failure. 837 */ 838 int 839 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 840 { 841 char *sdup, *cp, *tmp; 842 char *user = NULL, *host = NULL; 843 int port = -1, ret = -1; 844 845 if (userp != NULL) 846 *userp = NULL; 847 if (hostp != NULL) 848 *hostp = NULL; 849 if (portp != NULL) 850 *portp = -1; 851 852 if ((sdup = tmp = strdup(s)) == NULL) 853 return -1; 854 /* Extract optional username */ 855 if ((cp = strrchr(tmp, '@')) != NULL) { 856 *cp = '\0'; 857 if (*tmp == '\0') 858 goto out; 859 if ((user = strdup(tmp)) == NULL) 860 goto out; 861 tmp = cp + 1; 862 } 863 /* Extract mandatory hostname */ 864 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 865 goto out; 866 host = xstrdup(cleanhostname(cp)); 867 /* Convert and verify optional port */ 868 if (tmp != NULL && *tmp != '\0') { 869 if ((port = a2port(tmp)) <= 0) 870 goto out; 871 } 872 /* Success */ 873 if (userp != NULL) { 874 *userp = user; 875 user = NULL; 876 } 877 if (hostp != NULL) { 878 *hostp = host; 879 host = NULL; 880 } 881 if (portp != NULL) 882 *portp = port; 883 ret = 0; 884 out: 885 free(sdup); 886 free(user); 887 free(host); 888 return ret; 889 } 890 891 /* 892 * Converts a two-byte hex string to decimal. 893 * Returns the decimal value or -1 for invalid input. 894 */ 895 static int 896 hexchar(const char *s) 897 { 898 unsigned char result[2]; 899 int i; 900 901 for (i = 0; i < 2; i++) { 902 if (s[i] >= '0' && s[i] <= '9') 903 result[i] = (unsigned char)(s[i] - '0'); 904 else if (s[i] >= 'a' && s[i] <= 'f') 905 result[i] = (unsigned char)(s[i] - 'a') + 10; 906 else if (s[i] >= 'A' && s[i] <= 'F') 907 result[i] = (unsigned char)(s[i] - 'A') + 10; 908 else 909 return -1; 910 } 911 return (result[0] << 4) | result[1]; 912 } 913 914 /* 915 * Decode an url-encoded string. 916 * Returns a newly allocated string on success or NULL on failure. 917 */ 918 static char * 919 urldecode(const char *src) 920 { 921 char *ret, *dst; 922 int ch; 923 924 ret = xmalloc(strlen(src) + 1); 925 for (dst = ret; *src != '\0'; src++) { 926 switch (*src) { 927 case '+': 928 *dst++ = ' '; 929 break; 930 case '%': 931 if (!isxdigit((unsigned char)src[1]) || 932 !isxdigit((unsigned char)src[2]) || 933 (ch = hexchar(src + 1)) == -1) { 934 free(ret); 935 return NULL; 936 } 937 *dst++ = ch; 938 src += 2; 939 break; 940 default: 941 *dst++ = *src; 942 break; 943 } 944 } 945 *dst = '\0'; 946 947 return ret; 948 } 949 950 /* 951 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 952 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 953 * Either user or path may be url-encoded (but not host or port). 954 * Caller must free returned user, host and path. 955 * Any of the pointer return arguments may be NULL (useful for syntax checking) 956 * but the scheme must always be specified. 957 * If user was not specified then *userp will be set to NULL. 958 * If port was not specified then *portp will be -1. 959 * If path was not specified then *pathp will be set to NULL. 960 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 961 */ 962 int 963 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 964 int *portp, char **pathp) 965 { 966 char *uridup, *cp, *tmp, ch; 967 char *user = NULL, *host = NULL, *path = NULL; 968 int port = -1, ret = -1; 969 size_t len; 970 971 len = strlen(scheme); 972 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 973 return 1; 974 uri += len + 3; 975 976 if (userp != NULL) 977 *userp = NULL; 978 if (hostp != NULL) 979 *hostp = NULL; 980 if (portp != NULL) 981 *portp = -1; 982 if (pathp != NULL) 983 *pathp = NULL; 984 985 uridup = tmp = xstrdup(uri); 986 987 /* Extract optional ssh-info (username + connection params) */ 988 if ((cp = strchr(tmp, '@')) != NULL) { 989 char *delim; 990 991 *cp = '\0'; 992 /* Extract username and connection params */ 993 if ((delim = strchr(tmp, ';')) != NULL) { 994 /* Just ignore connection params for now */ 995 *delim = '\0'; 996 } 997 if (*tmp == '\0') { 998 /* Empty username */ 999 goto out; 1000 } 1001 if ((user = urldecode(tmp)) == NULL) 1002 goto out; 1003 tmp = cp + 1; 1004 } 1005 1006 /* Extract mandatory hostname */ 1007 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 1008 goto out; 1009 host = xstrdup(cleanhostname(cp)); 1010 if (!valid_domain(host, 0, NULL)) 1011 goto out; 1012 1013 if (tmp != NULL && *tmp != '\0') { 1014 if (ch == ':') { 1015 /* Convert and verify port. */ 1016 if ((cp = strchr(tmp, '/')) != NULL) 1017 *cp = '\0'; 1018 if ((port = a2port(tmp)) <= 0) 1019 goto out; 1020 tmp = cp ? cp + 1 : NULL; 1021 } 1022 if (tmp != NULL && *tmp != '\0') { 1023 /* Extract optional path */ 1024 if ((path = urldecode(tmp)) == NULL) 1025 goto out; 1026 } 1027 } 1028 1029 /* Success */ 1030 if (userp != NULL) { 1031 *userp = user; 1032 user = NULL; 1033 } 1034 if (hostp != NULL) { 1035 *hostp = host; 1036 host = NULL; 1037 } 1038 if (portp != NULL) 1039 *portp = port; 1040 if (pathp != NULL) { 1041 *pathp = path; 1042 path = NULL; 1043 } 1044 ret = 0; 1045 out: 1046 free(uridup); 1047 free(user); 1048 free(host); 1049 free(path); 1050 return ret; 1051 } 1052 1053 /* function to assist building execv() arguments */ 1054 void 1055 addargs(arglist *args, char *fmt, ...) 1056 { 1057 va_list ap; 1058 char *cp; 1059 u_int nalloc; 1060 int r; 1061 1062 va_start(ap, fmt); 1063 r = vasprintf(&cp, fmt, ap); 1064 va_end(ap); 1065 if (r == -1) 1066 fatal("addargs: argument too long"); 1067 1068 nalloc = args->nalloc; 1069 if (args->list == NULL) { 1070 nalloc = 32; 1071 args->num = 0; 1072 } else if (args->num+2 >= nalloc) 1073 nalloc *= 2; 1074 1075 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 1076 args->nalloc = nalloc; 1077 args->list[args->num++] = cp; 1078 args->list[args->num] = NULL; 1079 } 1080 1081 void 1082 replacearg(arglist *args, u_int which, char *fmt, ...) 1083 { 1084 va_list ap; 1085 char *cp; 1086 int r; 1087 1088 va_start(ap, fmt); 1089 r = vasprintf(&cp, fmt, ap); 1090 va_end(ap); 1091 if (r == -1) 1092 fatal("replacearg: argument too long"); 1093 1094 if (which >= args->num) 1095 fatal("replacearg: tried to replace invalid arg %d >= %d", 1096 which, args->num); 1097 free(args->list[which]); 1098 args->list[which] = cp; 1099 } 1100 1101 void 1102 freeargs(arglist *args) 1103 { 1104 u_int i; 1105 1106 if (args->list != NULL) { 1107 for (i = 0; i < args->num; i++) 1108 free(args->list[i]); 1109 free(args->list); 1110 args->nalloc = args->num = 0; 1111 args->list = NULL; 1112 } 1113 } 1114 1115 /* 1116 * Expands tildes in the file name. Returns data allocated by xmalloc. 1117 * Warning: this calls getpw*. 1118 */ 1119 int 1120 tilde_expand(const char *filename, uid_t uid, char **retp) 1121 { 1122 const char *path, *sep; 1123 char user[128], *ret; 1124 struct passwd *pw; 1125 u_int len, slash; 1126 1127 if (*filename != '~') { 1128 *retp = xstrdup(filename); 1129 return 0; 1130 } 1131 filename++; 1132 1133 path = strchr(filename, '/'); 1134 if (path != NULL && path > filename) { /* ~user/path */ 1135 slash = path - filename; 1136 if (slash > sizeof(user) - 1) { 1137 error_f("~username too long"); 1138 return -1; 1139 } 1140 memcpy(user, filename, slash); 1141 user[slash] = '\0'; 1142 if ((pw = getpwnam(user)) == NULL) { 1143 error_f("No such user %s", user); 1144 return -1; 1145 } 1146 } else if ((pw = getpwuid(uid)) == NULL) { /* ~/path */ 1147 error_f("No such uid %ld", (long)uid); 1148 return -1; 1149 } 1150 1151 /* Make sure directory has a trailing '/' */ 1152 len = strlen(pw->pw_dir); 1153 if (len == 0 || pw->pw_dir[len - 1] != '/') 1154 sep = "/"; 1155 else 1156 sep = ""; 1157 1158 /* Skip leading '/' from specified path */ 1159 if (path != NULL) 1160 filename = path + 1; 1161 1162 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) { 1163 error_f("Path too long"); 1164 return -1; 1165 } 1166 1167 *retp = ret; 1168 return 0; 1169 } 1170 1171 char * 1172 tilde_expand_filename(const char *filename, uid_t uid) 1173 { 1174 char *ret; 1175 1176 if (tilde_expand(filename, uid, &ret) != 0) 1177 cleanup_exit(255); 1178 return ret; 1179 } 1180 1181 /* 1182 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1183 * substitutions. A number of escapes may be specified as 1184 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1185 * by a NULL escape_char. Returns replaced string in memory allocated by 1186 * xmalloc which the caller must free. 1187 */ 1188 static char * 1189 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1190 const char *string, va_list ap) 1191 { 1192 #define EXPAND_MAX_KEYS 16 1193 u_int num_keys = 0, i; 1194 struct { 1195 const char *key; 1196 const char *repl; 1197 } keys[EXPAND_MAX_KEYS]; 1198 struct sshbuf *buf; 1199 int r, missingvar = 0; 1200 char *ret = NULL, *var, *varend, *val; 1201 size_t len; 1202 1203 if ((buf = sshbuf_new()) == NULL) 1204 fatal_f("sshbuf_new failed"); 1205 if (parseerror == NULL) 1206 fatal_f("null parseerror arg"); 1207 *parseerror = 1; 1208 1209 /* Gather keys if we're doing percent expansion. */ 1210 if (percent) { 1211 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1212 keys[num_keys].key = va_arg(ap, char *); 1213 if (keys[num_keys].key == NULL) 1214 break; 1215 keys[num_keys].repl = va_arg(ap, char *); 1216 if (keys[num_keys].repl == NULL) { 1217 fatal_f("NULL replacement for token %s", 1218 keys[num_keys].key); 1219 } 1220 } 1221 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1222 fatal_f("too many keys"); 1223 if (num_keys == 0) 1224 fatal_f("percent expansion without token list"); 1225 } 1226 1227 /* Expand string */ 1228 for (i = 0; *string != '\0'; string++) { 1229 /* Optionally process ${ENVIRONMENT} expansions. */ 1230 if (dollar && string[0] == '$' && string[1] == '{') { 1231 string += 2; /* skip over '${' */ 1232 if ((varend = strchr(string, '}')) == NULL) { 1233 error_f("environment variable '%s' missing " 1234 "closing '}'", string); 1235 goto out; 1236 } 1237 len = varend - string; 1238 if (len == 0) { 1239 error_f("zero-length environment variable"); 1240 goto out; 1241 } 1242 var = xmalloc(len + 1); 1243 (void)strlcpy(var, string, len + 1); 1244 if ((val = getenv(var)) == NULL) { 1245 error_f("env var ${%s} has no value", var); 1246 missingvar = 1; 1247 } else { 1248 debug3_f("expand ${%s} -> '%s'", var, val); 1249 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1250 fatal_fr(r, "sshbuf_put ${}"); 1251 } 1252 free(var); 1253 string += len; 1254 continue; 1255 } 1256 1257 /* 1258 * Process percent expansions if we have a list of TOKENs. 1259 * If we're not doing percent expansion everything just gets 1260 * appended here. 1261 */ 1262 if (*string != '%' || !percent) { 1263 append: 1264 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1265 fatal_fr(r, "sshbuf_put_u8 %%"); 1266 continue; 1267 } 1268 string++; 1269 /* %% case */ 1270 if (*string == '%') 1271 goto append; 1272 if (*string == '\0') { 1273 error_f("invalid format"); 1274 goto out; 1275 } 1276 for (i = 0; i < num_keys; i++) { 1277 if (strchr(keys[i].key, *string) != NULL) { 1278 if ((r = sshbuf_put(buf, keys[i].repl, 1279 strlen(keys[i].repl))) != 0) 1280 fatal_fr(r, "sshbuf_put %%-repl"); 1281 break; 1282 } 1283 } 1284 if (i >= num_keys) { 1285 error_f("unknown key %%%c", *string); 1286 goto out; 1287 } 1288 } 1289 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1290 fatal_f("sshbuf_dup_string failed"); 1291 *parseerror = 0; 1292 out: 1293 sshbuf_free(buf); 1294 return *parseerror ? NULL : ret; 1295 #undef EXPAND_MAX_KEYS 1296 } 1297 1298 /* 1299 * Expand only environment variables. 1300 * Note that although this function is variadic like the other similar 1301 * functions, any such arguments will be unused. 1302 */ 1303 1304 char * 1305 dollar_expand(int *parseerr, const char *string, ...) 1306 { 1307 char *ret; 1308 int err; 1309 va_list ap; 1310 1311 va_start(ap, string); 1312 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1313 va_end(ap); 1314 if (parseerr != NULL) 1315 *parseerr = err; 1316 return ret; 1317 } 1318 1319 /* 1320 * Returns expanded string or NULL if a specified environment variable is 1321 * not defined, or calls fatal if the string is invalid. 1322 */ 1323 char * 1324 percent_expand(const char *string, ...) 1325 { 1326 char *ret; 1327 int err; 1328 va_list ap; 1329 1330 va_start(ap, string); 1331 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1332 va_end(ap); 1333 if (err) 1334 fatal_f("failed"); 1335 return ret; 1336 } 1337 1338 /* 1339 * Returns expanded string or NULL if a specified environment variable is 1340 * not defined, or calls fatal if the string is invalid. 1341 */ 1342 char * 1343 percent_dollar_expand(const char *string, ...) 1344 { 1345 char *ret; 1346 int err; 1347 va_list ap; 1348 1349 va_start(ap, string); 1350 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1351 va_end(ap); 1352 if (err) 1353 fatal_f("failed"); 1354 return ret; 1355 } 1356 1357 int 1358 tun_open(int tun, int mode, char **ifname) 1359 { 1360 #if defined(CUSTOM_SYS_TUN_OPEN) 1361 return (sys_tun_open(tun, mode, ifname)); 1362 #elif defined(SSH_TUN_OPENBSD) 1363 struct ifreq ifr; 1364 char name[100]; 1365 int fd = -1, sock; 1366 const char *tunbase = "tun"; 1367 1368 if (ifname != NULL) 1369 *ifname = NULL; 1370 1371 if (mode == SSH_TUNMODE_ETHERNET) 1372 tunbase = "tap"; 1373 1374 /* Open the tunnel device */ 1375 if (tun <= SSH_TUNID_MAX) { 1376 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1377 fd = open(name, O_RDWR); 1378 } else if (tun == SSH_TUNID_ANY) { 1379 for (tun = 100; tun >= 0; tun--) { 1380 snprintf(name, sizeof(name), "/dev/%s%d", 1381 tunbase, tun); 1382 if ((fd = open(name, O_RDWR)) >= 0) 1383 break; 1384 } 1385 } else { 1386 debug_f("invalid tunnel %u", tun); 1387 return -1; 1388 } 1389 1390 if (fd == -1) { 1391 debug_f("%s open: %s", name, strerror(errno)); 1392 return -1; 1393 } 1394 1395 debug_f("%s mode %d fd %d", name, mode, fd); 1396 1397 /* Bring interface up if it is not already */ 1398 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1399 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1400 goto failed; 1401 1402 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1403 debug_f("get interface %s flags: %s", ifr.ifr_name, 1404 strerror(errno)); 1405 goto failed; 1406 } 1407 1408 if (!(ifr.ifr_flags & IFF_UP)) { 1409 ifr.ifr_flags |= IFF_UP; 1410 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1411 debug_f("activate interface %s: %s", ifr.ifr_name, 1412 strerror(errno)); 1413 goto failed; 1414 } 1415 } 1416 1417 if (ifname != NULL) 1418 *ifname = xstrdup(ifr.ifr_name); 1419 1420 close(sock); 1421 return fd; 1422 1423 failed: 1424 if (fd >= 0) 1425 close(fd); 1426 if (sock >= 0) 1427 close(sock); 1428 return -1; 1429 #else 1430 error("Tunnel interfaces are not supported on this platform"); 1431 return (-1); 1432 #endif 1433 } 1434 1435 void 1436 sanitise_stdfd(void) 1437 { 1438 int nullfd, dupfd; 1439 1440 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1441 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1442 strerror(errno)); 1443 exit(1); 1444 } 1445 while (++dupfd <= STDERR_FILENO) { 1446 /* Only populate closed fds. */ 1447 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1448 if (dup2(nullfd, dupfd) == -1) { 1449 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1450 exit(1); 1451 } 1452 } 1453 } 1454 if (nullfd > STDERR_FILENO) 1455 close(nullfd); 1456 } 1457 1458 char * 1459 tohex(const void *vp, size_t l) 1460 { 1461 const u_char *p = (const u_char *)vp; 1462 char b[3], *r; 1463 size_t i, hl; 1464 1465 if (l > 65536) 1466 return xstrdup("tohex: length > 65536"); 1467 1468 hl = l * 2 + 1; 1469 r = xcalloc(1, hl); 1470 for (i = 0; i < l; i++) { 1471 snprintf(b, sizeof(b), "%02x", p[i]); 1472 strlcat(r, b, hl); 1473 } 1474 return (r); 1475 } 1476 1477 /* 1478 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1479 * then the separator 'sep' will be prepended before the formatted arguments. 1480 * Extended strings are heap allocated. 1481 */ 1482 void 1483 xextendf(char **sp, const char *sep, const char *fmt, ...) 1484 { 1485 va_list ap; 1486 char *tmp1, *tmp2; 1487 1488 va_start(ap, fmt); 1489 xvasprintf(&tmp1, fmt, ap); 1490 va_end(ap); 1491 1492 if (*sp == NULL || **sp == '\0') { 1493 free(*sp); 1494 *sp = tmp1; 1495 return; 1496 } 1497 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1498 free(tmp1); 1499 free(*sp); 1500 *sp = tmp2; 1501 } 1502 1503 1504 u_int64_t 1505 get_u64(const void *vp) 1506 { 1507 const u_char *p = (const u_char *)vp; 1508 u_int64_t v; 1509 1510 v = (u_int64_t)p[0] << 56; 1511 v |= (u_int64_t)p[1] << 48; 1512 v |= (u_int64_t)p[2] << 40; 1513 v |= (u_int64_t)p[3] << 32; 1514 v |= (u_int64_t)p[4] << 24; 1515 v |= (u_int64_t)p[5] << 16; 1516 v |= (u_int64_t)p[6] << 8; 1517 v |= (u_int64_t)p[7]; 1518 1519 return (v); 1520 } 1521 1522 u_int32_t 1523 get_u32(const void *vp) 1524 { 1525 const u_char *p = (const u_char *)vp; 1526 u_int32_t v; 1527 1528 v = (u_int32_t)p[0] << 24; 1529 v |= (u_int32_t)p[1] << 16; 1530 v |= (u_int32_t)p[2] << 8; 1531 v |= (u_int32_t)p[3]; 1532 1533 return (v); 1534 } 1535 1536 u_int32_t 1537 get_u32_le(const void *vp) 1538 { 1539 const u_char *p = (const u_char *)vp; 1540 u_int32_t v; 1541 1542 v = (u_int32_t)p[0]; 1543 v |= (u_int32_t)p[1] << 8; 1544 v |= (u_int32_t)p[2] << 16; 1545 v |= (u_int32_t)p[3] << 24; 1546 1547 return (v); 1548 } 1549 1550 u_int16_t 1551 get_u16(const void *vp) 1552 { 1553 const u_char *p = (const u_char *)vp; 1554 u_int16_t v; 1555 1556 v = (u_int16_t)p[0] << 8; 1557 v |= (u_int16_t)p[1]; 1558 1559 return (v); 1560 } 1561 1562 void 1563 put_u64(void *vp, u_int64_t v) 1564 { 1565 u_char *p = (u_char *)vp; 1566 1567 p[0] = (u_char)(v >> 56) & 0xff; 1568 p[1] = (u_char)(v >> 48) & 0xff; 1569 p[2] = (u_char)(v >> 40) & 0xff; 1570 p[3] = (u_char)(v >> 32) & 0xff; 1571 p[4] = (u_char)(v >> 24) & 0xff; 1572 p[5] = (u_char)(v >> 16) & 0xff; 1573 p[6] = (u_char)(v >> 8) & 0xff; 1574 p[7] = (u_char)v & 0xff; 1575 } 1576 1577 void 1578 put_u32(void *vp, u_int32_t v) 1579 { 1580 u_char *p = (u_char *)vp; 1581 1582 p[0] = (u_char)(v >> 24) & 0xff; 1583 p[1] = (u_char)(v >> 16) & 0xff; 1584 p[2] = (u_char)(v >> 8) & 0xff; 1585 p[3] = (u_char)v & 0xff; 1586 } 1587 1588 void 1589 put_u32_le(void *vp, u_int32_t v) 1590 { 1591 u_char *p = (u_char *)vp; 1592 1593 p[0] = (u_char)v & 0xff; 1594 p[1] = (u_char)(v >> 8) & 0xff; 1595 p[2] = (u_char)(v >> 16) & 0xff; 1596 p[3] = (u_char)(v >> 24) & 0xff; 1597 } 1598 1599 void 1600 put_u16(void *vp, u_int16_t v) 1601 { 1602 u_char *p = (u_char *)vp; 1603 1604 p[0] = (u_char)(v >> 8) & 0xff; 1605 p[1] = (u_char)v & 0xff; 1606 } 1607 1608 void 1609 ms_subtract_diff(struct timeval *start, int *ms) 1610 { 1611 struct timeval diff, finish; 1612 1613 monotime_tv(&finish); 1614 timersub(&finish, start, &diff); 1615 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1616 } 1617 1618 void 1619 ms_to_timeval(struct timeval *tv, int ms) 1620 { 1621 if (ms < 0) 1622 ms = 0; 1623 tv->tv_sec = ms / 1000; 1624 tv->tv_usec = (ms % 1000) * 1000; 1625 } 1626 1627 void 1628 monotime_ts(struct timespec *ts) 1629 { 1630 struct timeval tv; 1631 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \ 1632 defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME)) 1633 static int gettime_failed = 0; 1634 1635 if (!gettime_failed) { 1636 # ifdef CLOCK_BOOTTIME 1637 if (clock_gettime(CLOCK_BOOTTIME, ts) == 0) 1638 return; 1639 # endif /* CLOCK_BOOTTIME */ 1640 # ifdef CLOCK_MONOTONIC 1641 if (clock_gettime(CLOCK_MONOTONIC, ts) == 0) 1642 return; 1643 # endif /* CLOCK_MONOTONIC */ 1644 # ifdef CLOCK_REALTIME 1645 /* Not monotonic, but we're almost out of options here. */ 1646 if (clock_gettime(CLOCK_REALTIME, ts) == 0) 1647 return; 1648 # endif /* CLOCK_REALTIME */ 1649 debug3("clock_gettime: %s", strerror(errno)); 1650 gettime_failed = 1; 1651 } 1652 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */ 1653 gettimeofday(&tv, NULL); 1654 ts->tv_sec = tv.tv_sec; 1655 ts->tv_nsec = (long)tv.tv_usec * 1000; 1656 } 1657 1658 void 1659 monotime_tv(struct timeval *tv) 1660 { 1661 struct timespec ts; 1662 1663 monotime_ts(&ts); 1664 tv->tv_sec = ts.tv_sec; 1665 tv->tv_usec = ts.tv_nsec / 1000; 1666 } 1667 1668 time_t 1669 monotime(void) 1670 { 1671 struct timespec ts; 1672 1673 monotime_ts(&ts); 1674 return ts.tv_sec; 1675 } 1676 1677 double 1678 monotime_double(void) 1679 { 1680 struct timespec ts; 1681 1682 monotime_ts(&ts); 1683 return ts.tv_sec + ((double)ts.tv_nsec / 1000000000); 1684 } 1685 1686 void 1687 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1688 { 1689 bw->buflen = buflen; 1690 bw->rate = kbps; 1691 bw->thresh = buflen; 1692 bw->lamt = 0; 1693 timerclear(&bw->bwstart); 1694 timerclear(&bw->bwend); 1695 } 1696 1697 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1698 void 1699 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1700 { 1701 u_int64_t waitlen; 1702 struct timespec ts, rm; 1703 1704 bw->lamt += read_len; 1705 if (!timerisset(&bw->bwstart)) { 1706 monotime_tv(&bw->bwstart); 1707 return; 1708 } 1709 if (bw->lamt < bw->thresh) 1710 return; 1711 1712 monotime_tv(&bw->bwend); 1713 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1714 if (!timerisset(&bw->bwend)) 1715 return; 1716 1717 bw->lamt *= 8; 1718 waitlen = (double)1000000L * bw->lamt / bw->rate; 1719 1720 bw->bwstart.tv_sec = waitlen / 1000000L; 1721 bw->bwstart.tv_usec = waitlen % 1000000L; 1722 1723 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1724 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1725 1726 /* Adjust the wait time */ 1727 if (bw->bwend.tv_sec) { 1728 bw->thresh /= 2; 1729 if (bw->thresh < bw->buflen / 4) 1730 bw->thresh = bw->buflen / 4; 1731 } else if (bw->bwend.tv_usec < 10000) { 1732 bw->thresh *= 2; 1733 if (bw->thresh > bw->buflen * 8) 1734 bw->thresh = bw->buflen * 8; 1735 } 1736 1737 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1738 while (nanosleep(&ts, &rm) == -1) { 1739 if (errno != EINTR) 1740 break; 1741 ts = rm; 1742 } 1743 } 1744 1745 bw->lamt = 0; 1746 monotime_tv(&bw->bwstart); 1747 } 1748 1749 /* Make a template filename for mk[sd]temp() */ 1750 void 1751 mktemp_proto(char *s, size_t len) 1752 { 1753 const char *tmpdir; 1754 int r; 1755 1756 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1757 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1758 if (r > 0 && (size_t)r < len) 1759 return; 1760 } 1761 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1762 if (r < 0 || (size_t)r >= len) 1763 fatal_f("template string too short"); 1764 } 1765 1766 static const struct { 1767 const char *name; 1768 int value; 1769 } ipqos[] = { 1770 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1771 { "af11", IPTOS_DSCP_AF11 }, 1772 { "af12", IPTOS_DSCP_AF12 }, 1773 { "af13", IPTOS_DSCP_AF13 }, 1774 { "af21", IPTOS_DSCP_AF21 }, 1775 { "af22", IPTOS_DSCP_AF22 }, 1776 { "af23", IPTOS_DSCP_AF23 }, 1777 { "af31", IPTOS_DSCP_AF31 }, 1778 { "af32", IPTOS_DSCP_AF32 }, 1779 { "af33", IPTOS_DSCP_AF33 }, 1780 { "af41", IPTOS_DSCP_AF41 }, 1781 { "af42", IPTOS_DSCP_AF42 }, 1782 { "af43", IPTOS_DSCP_AF43 }, 1783 { "cs0", IPTOS_DSCP_CS0 }, 1784 { "cs1", IPTOS_DSCP_CS1 }, 1785 { "cs2", IPTOS_DSCP_CS2 }, 1786 { "cs3", IPTOS_DSCP_CS3 }, 1787 { "cs4", IPTOS_DSCP_CS4 }, 1788 { "cs5", IPTOS_DSCP_CS5 }, 1789 { "cs6", IPTOS_DSCP_CS6 }, 1790 { "cs7", IPTOS_DSCP_CS7 }, 1791 { "ef", IPTOS_DSCP_EF }, 1792 { "le", IPTOS_DSCP_LE }, 1793 { "lowdelay", IPTOS_LOWDELAY }, 1794 { "throughput", IPTOS_THROUGHPUT }, 1795 { "reliability", IPTOS_RELIABILITY }, 1796 { NULL, -1 } 1797 }; 1798 1799 int 1800 parse_ipqos(const char *cp) 1801 { 1802 u_int i; 1803 char *ep; 1804 long val; 1805 1806 if (cp == NULL) 1807 return -1; 1808 for (i = 0; ipqos[i].name != NULL; i++) { 1809 if (strcasecmp(cp, ipqos[i].name) == 0) 1810 return ipqos[i].value; 1811 } 1812 /* Try parsing as an integer */ 1813 val = strtol(cp, &ep, 0); 1814 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1815 return -1; 1816 return val; 1817 } 1818 1819 const char * 1820 iptos2str(int iptos) 1821 { 1822 int i; 1823 static char iptos_str[sizeof "0xff"]; 1824 1825 for (i = 0; ipqos[i].name != NULL; i++) { 1826 if (ipqos[i].value == iptos) 1827 return ipqos[i].name; 1828 } 1829 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1830 return iptos_str; 1831 } 1832 1833 void 1834 lowercase(char *s) 1835 { 1836 for (; *s; s++) 1837 *s = tolower((u_char)*s); 1838 } 1839 1840 int 1841 unix_listener(const char *path, int backlog, int unlink_first) 1842 { 1843 struct sockaddr_un sunaddr; 1844 int saved_errno, sock; 1845 1846 memset(&sunaddr, 0, sizeof(sunaddr)); 1847 sunaddr.sun_family = AF_UNIX; 1848 if (strlcpy(sunaddr.sun_path, path, 1849 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1850 error_f("path \"%s\" too long for Unix domain socket", path); 1851 errno = ENAMETOOLONG; 1852 return -1; 1853 } 1854 1855 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1856 if (sock == -1) { 1857 saved_errno = errno; 1858 error_f("socket: %.100s", strerror(errno)); 1859 errno = saved_errno; 1860 return -1; 1861 } 1862 if (unlink_first == 1) { 1863 if (unlink(path) != 0 && errno != ENOENT) 1864 error("unlink(%s): %.100s", path, strerror(errno)); 1865 } 1866 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1867 saved_errno = errno; 1868 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1869 close(sock); 1870 errno = saved_errno; 1871 return -1; 1872 } 1873 if (listen(sock, backlog) == -1) { 1874 saved_errno = errno; 1875 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1876 close(sock); 1877 unlink(path); 1878 errno = saved_errno; 1879 return -1; 1880 } 1881 return sock; 1882 } 1883 1884 void 1885 sock_set_v6only(int s) 1886 { 1887 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__) 1888 int on = 1; 1889 1890 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s); 1891 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) 1892 error("setsockopt IPV6_V6ONLY: %s", strerror(errno)); 1893 #endif 1894 } 1895 1896 /* 1897 * Compares two strings that maybe be NULL. Returns non-zero if strings 1898 * are both NULL or are identical, returns zero otherwise. 1899 */ 1900 static int 1901 strcmp_maybe_null(const char *a, const char *b) 1902 { 1903 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1904 return 0; 1905 if (a != NULL && strcmp(a, b) != 0) 1906 return 0; 1907 return 1; 1908 } 1909 1910 /* 1911 * Compare two forwards, returning non-zero if they are identical or 1912 * zero otherwise. 1913 */ 1914 int 1915 forward_equals(const struct Forward *a, const struct Forward *b) 1916 { 1917 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1918 return 0; 1919 if (a->listen_port != b->listen_port) 1920 return 0; 1921 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1922 return 0; 1923 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1924 return 0; 1925 if (a->connect_port != b->connect_port) 1926 return 0; 1927 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1928 return 0; 1929 /* allocated_port and handle are not checked */ 1930 return 1; 1931 } 1932 1933 /* returns 1 if process is already daemonized, 0 otherwise */ 1934 int 1935 daemonized(void) 1936 { 1937 int fd; 1938 1939 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1940 close(fd); 1941 return 0; /* have controlling terminal */ 1942 } 1943 if (getppid() != 1) 1944 return 0; /* parent is not init */ 1945 if (getsid(0) != getpid()) 1946 return 0; /* not session leader */ 1947 debug3("already daemonized"); 1948 return 1; 1949 } 1950 1951 /* 1952 * Splits 's' into an argument vector. Handles quoted string and basic 1953 * escape characters (\\, \", \'). Caller must free the argument vector 1954 * and its members. 1955 */ 1956 int 1957 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1958 { 1959 int r = SSH_ERR_INTERNAL_ERROR; 1960 int argc = 0, quote, i, j; 1961 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1962 1963 *argvp = NULL; 1964 *argcp = 0; 1965 1966 for (i = 0; s[i] != '\0'; i++) { 1967 /* Skip leading whitespace */ 1968 if (s[i] == ' ' || s[i] == '\t') 1969 continue; 1970 if (terminate_on_comment && s[i] == '#') 1971 break; 1972 /* Start of a token */ 1973 quote = 0; 1974 1975 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1976 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1977 argv[argc] = NULL; 1978 1979 /* Copy the token in, removing escapes */ 1980 for (j = 0; s[i] != '\0'; i++) { 1981 if (s[i] == '\\') { 1982 if (s[i + 1] == '\'' || 1983 s[i + 1] == '\"' || 1984 s[i + 1] == '\\' || 1985 (quote == 0 && s[i + 1] == ' ')) { 1986 i++; /* Skip '\' */ 1987 arg[j++] = s[i]; 1988 } else { 1989 /* Unrecognised escape */ 1990 arg[j++] = s[i]; 1991 } 1992 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1993 break; /* done */ 1994 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1995 quote = s[i]; /* quote start */ 1996 else if (quote != 0 && s[i] == quote) 1997 quote = 0; /* quote end */ 1998 else 1999 arg[j++] = s[i]; 2000 } 2001 if (s[i] == '\0') { 2002 if (quote != 0) { 2003 /* Ran out of string looking for close quote */ 2004 r = SSH_ERR_INVALID_FORMAT; 2005 goto out; 2006 } 2007 break; 2008 } 2009 } 2010 /* Success */ 2011 *argcp = argc; 2012 *argvp = argv; 2013 argc = 0; 2014 argv = NULL; 2015 r = 0; 2016 out: 2017 if (argc != 0 && argv != NULL) { 2018 for (i = 0; i < argc; i++) 2019 free(argv[i]); 2020 free(argv); 2021 } 2022 return r; 2023 } 2024 2025 /* 2026 * Reassemble an argument vector into a string, quoting and escaping as 2027 * necessary. Caller must free returned string. 2028 */ 2029 char * 2030 argv_assemble(int argc, char **argv) 2031 { 2032 int i, j, ws, r; 2033 char c, *ret; 2034 struct sshbuf *buf, *arg; 2035 2036 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2037 fatal_f("sshbuf_new failed"); 2038 2039 for (i = 0; i < argc; i++) { 2040 ws = 0; 2041 sshbuf_reset(arg); 2042 for (j = 0; argv[i][j] != '\0'; j++) { 2043 r = 0; 2044 c = argv[i][j]; 2045 switch (c) { 2046 case ' ': 2047 case '\t': 2048 ws = 1; 2049 r = sshbuf_put_u8(arg, c); 2050 break; 2051 case '\\': 2052 case '\'': 2053 case '"': 2054 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2055 break; 2056 /* FALLTHROUGH */ 2057 default: 2058 r = sshbuf_put_u8(arg, c); 2059 break; 2060 } 2061 if (r != 0) 2062 fatal_fr(r, "sshbuf_put_u8"); 2063 } 2064 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2065 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2066 (r = sshbuf_putb(buf, arg)) != 0 || 2067 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2068 fatal_fr(r, "assemble"); 2069 } 2070 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2071 fatal_f("malloc failed"); 2072 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2073 ret[sshbuf_len(buf)] = '\0'; 2074 sshbuf_free(buf); 2075 sshbuf_free(arg); 2076 return ret; 2077 } 2078 2079 char * 2080 argv_next(int *argcp, char ***argvp) 2081 { 2082 char *ret = (*argvp)[0]; 2083 2084 if (*argcp > 0 && ret != NULL) { 2085 (*argcp)--; 2086 (*argvp)++; 2087 } 2088 return ret; 2089 } 2090 2091 void 2092 argv_consume(int *argcp) 2093 { 2094 *argcp = 0; 2095 } 2096 2097 void 2098 argv_free(char **av, int ac) 2099 { 2100 int i; 2101 2102 if (av == NULL) 2103 return; 2104 for (i = 0; i < ac; i++) 2105 free(av[i]); 2106 free(av); 2107 } 2108 2109 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2110 int 2111 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2112 { 2113 int status; 2114 2115 while (waitpid(pid, &status, 0) == -1) { 2116 if (errno != EINTR) { 2117 error("%s waitpid: %s", tag, strerror(errno)); 2118 return -1; 2119 } 2120 } 2121 if (WIFSIGNALED(status)) { 2122 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2123 return -1; 2124 } else if (WEXITSTATUS(status) != 0) { 2125 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2126 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2127 return -1; 2128 } 2129 return 0; 2130 } 2131 2132 /* 2133 * Check a given path for security. This is defined as all components 2134 * of the path to the file must be owned by either the owner of 2135 * of the file or root and no directories must be group or world writable. 2136 * 2137 * XXX Should any specific check be done for sym links ? 2138 * 2139 * Takes a file name, its stat information (preferably from fstat() to 2140 * avoid races), the uid of the expected owner, their home directory and an 2141 * error buffer plus max size as arguments. 2142 * 2143 * Returns 0 on success and -1 on failure 2144 */ 2145 int 2146 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2147 uid_t uid, char *err, size_t errlen) 2148 { 2149 char buf[PATH_MAX], homedir[PATH_MAX]; 2150 char *cp; 2151 int comparehome = 0; 2152 struct stat st; 2153 2154 if (realpath(name, buf) == NULL) { 2155 snprintf(err, errlen, "realpath %s failed: %s", name, 2156 strerror(errno)); 2157 return -1; 2158 } 2159 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2160 comparehome = 1; 2161 2162 if (!S_ISREG(stp->st_mode)) { 2163 snprintf(err, errlen, "%s is not a regular file", buf); 2164 return -1; 2165 } 2166 if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || 2167 (stp->st_mode & 022) != 0) { 2168 snprintf(err, errlen, "bad ownership or modes for file %s", 2169 buf); 2170 return -1; 2171 } 2172 2173 /* for each component of the canonical path, walking upwards */ 2174 for (;;) { 2175 if ((cp = dirname(buf)) == NULL) { 2176 snprintf(err, errlen, "dirname() failed"); 2177 return -1; 2178 } 2179 strlcpy(buf, cp, sizeof(buf)); 2180 2181 if (stat(buf, &st) == -1 || 2182 (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || 2183 (st.st_mode & 022) != 0) { 2184 snprintf(err, errlen, 2185 "bad ownership or modes for directory %s", buf); 2186 return -1; 2187 } 2188 2189 /* If are past the homedir then we can stop */ 2190 if (comparehome && strcmp(homedir, buf) == 0) 2191 break; 2192 2193 /* 2194 * dirname should always complete with a "/" path, 2195 * but we can be paranoid and check for "." too 2196 */ 2197 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2198 break; 2199 } 2200 return 0; 2201 } 2202 2203 /* 2204 * Version of safe_path() that accepts an open file descriptor to 2205 * avoid races. 2206 * 2207 * Returns 0 on success and -1 on failure 2208 */ 2209 int 2210 safe_path_fd(int fd, const char *file, struct passwd *pw, 2211 char *err, size_t errlen) 2212 { 2213 struct stat st; 2214 2215 /* check the open file to avoid races */ 2216 if (fstat(fd, &st) == -1) { 2217 snprintf(err, errlen, "cannot stat file %s: %s", 2218 file, strerror(errno)); 2219 return -1; 2220 } 2221 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2222 } 2223 2224 /* 2225 * Sets the value of the given variable in the environment. If the variable 2226 * already exists, its value is overridden. 2227 */ 2228 void 2229 child_set_env(char ***envp, u_int *envsizep, const char *name, 2230 const char *value) 2231 { 2232 char **env; 2233 u_int envsize; 2234 u_int i, namelen; 2235 2236 if (strchr(name, '=') != NULL) { 2237 error("Invalid environment variable \"%.100s\"", name); 2238 return; 2239 } 2240 2241 /* 2242 * If we're passed an uninitialized list, allocate a single null 2243 * entry before continuing. 2244 */ 2245 if (*envp == NULL && *envsizep == 0) { 2246 *envp = xmalloc(sizeof(char *)); 2247 *envp[0] = NULL; 2248 *envsizep = 1; 2249 } 2250 2251 /* 2252 * Find the slot where the value should be stored. If the variable 2253 * already exists, we reuse the slot; otherwise we append a new slot 2254 * at the end of the array, expanding if necessary. 2255 */ 2256 env = *envp; 2257 namelen = strlen(name); 2258 for (i = 0; env[i]; i++) 2259 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2260 break; 2261 if (env[i]) { 2262 /* Reuse the slot. */ 2263 free(env[i]); 2264 } else { 2265 /* New variable. Expand if necessary. */ 2266 envsize = *envsizep; 2267 if (i >= envsize - 1) { 2268 if (envsize >= 1000) 2269 fatal("child_set_env: too many env vars"); 2270 envsize += 50; 2271 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2272 *envsizep = envsize; 2273 } 2274 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2275 env[i + 1] = NULL; 2276 } 2277 2278 /* Allocate space and format the variable in the appropriate slot. */ 2279 /* XXX xasprintf */ 2280 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2281 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2282 } 2283 2284 /* 2285 * Check and optionally lowercase a domain name, also removes trailing '.' 2286 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2287 */ 2288 int 2289 valid_domain(char *name, int makelower, const char **errstr) 2290 { 2291 size_t i, l = strlen(name); 2292 u_char c, last = '\0'; 2293 static char errbuf[256]; 2294 2295 if (l == 0) { 2296 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2297 goto bad; 2298 } 2299 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2300 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2301 "starts with invalid character", name); 2302 goto bad; 2303 } 2304 for (i = 0; i < l; i++) { 2305 c = tolower((u_char)name[i]); 2306 if (makelower) 2307 name[i] = (char)c; 2308 if (last == '.' && c == '.') { 2309 snprintf(errbuf, sizeof(errbuf), "domain name " 2310 "\"%.100s\" contains consecutive separators", name); 2311 goto bad; 2312 } 2313 if (c != '.' && c != '-' && !isalnum(c) && 2314 c != '_') /* technically invalid, but common */ { 2315 snprintf(errbuf, sizeof(errbuf), "domain name " 2316 "\"%.100s\" contains invalid characters", name); 2317 goto bad; 2318 } 2319 last = c; 2320 } 2321 if (name[l - 1] == '.') 2322 name[l - 1] = '\0'; 2323 if (errstr != NULL) 2324 *errstr = NULL; 2325 return 1; 2326 bad: 2327 if (errstr != NULL) 2328 *errstr = errbuf; 2329 return 0; 2330 } 2331 2332 /* 2333 * Verify that a environment variable name (not including initial '$') is 2334 * valid; consisting of one or more alphanumeric or underscore characters only. 2335 * Returns 1 on valid, 0 otherwise. 2336 */ 2337 int 2338 valid_env_name(const char *name) 2339 { 2340 const char *cp; 2341 2342 if (name[0] == '\0') 2343 return 0; 2344 for (cp = name; *cp != '\0'; cp++) { 2345 if (!isalnum((u_char)*cp) && *cp != '_') 2346 return 0; 2347 } 2348 return 1; 2349 } 2350 2351 const char * 2352 atoi_err(const char *nptr, int *val) 2353 { 2354 const char *errstr = NULL; 2355 long long num; 2356 2357 if (nptr == NULL || *nptr == '\0') 2358 return "missing"; 2359 num = strtonum(nptr, 0, INT_MAX, &errstr); 2360 if (errstr == NULL) 2361 *val = (int)num; 2362 return errstr; 2363 } 2364 2365 int 2366 parse_absolute_time(const char *s, uint64_t *tp) 2367 { 2368 struct tm tm; 2369 time_t tt; 2370 char buf[32], *fmt; 2371 2372 *tp = 0; 2373 2374 /* 2375 * POSIX strptime says "The application shall ensure that there 2376 * is white-space or other non-alphanumeric characters between 2377 * any two conversion specifications" so arrange things this way. 2378 */ 2379 switch (strlen(s)) { 2380 case 8: /* YYYYMMDD */ 2381 fmt = "%Y-%m-%d"; 2382 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2383 break; 2384 case 12: /* YYYYMMDDHHMM */ 2385 fmt = "%Y-%m-%dT%H:%M"; 2386 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2387 s, s + 4, s + 6, s + 8, s + 10); 2388 break; 2389 case 14: /* YYYYMMDDHHMMSS */ 2390 fmt = "%Y-%m-%dT%H:%M:%S"; 2391 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2392 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2393 break; 2394 default: 2395 return SSH_ERR_INVALID_FORMAT; 2396 } 2397 2398 memset(&tm, 0, sizeof(tm)); 2399 if (strptime(buf, fmt, &tm) == NULL) 2400 return SSH_ERR_INVALID_FORMAT; 2401 if ((tt = mktime(&tm)) < 0) 2402 return SSH_ERR_INVALID_FORMAT; 2403 /* success */ 2404 *tp = (uint64_t)tt; 2405 return 0; 2406 } 2407 2408 /* On OpenBSD time_t is int64_t which is long long. */ 2409 /* #define SSH_TIME_T_MAX LLONG_MAX */ 2410 2411 void 2412 format_absolute_time(uint64_t t, char *buf, size_t len) 2413 { 2414 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2415 struct tm tm; 2416 2417 localtime_r(&tt, &tm); 2418 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2419 } 2420 2421 /* check if path is absolute */ 2422 int 2423 path_absolute(const char *path) 2424 { 2425 return (*path == '/') ? 1 : 0; 2426 } 2427 2428 void 2429 skip_space(char **cpp) 2430 { 2431 char *cp; 2432 2433 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2434 ; 2435 *cpp = cp; 2436 } 2437 2438 /* authorized_key-style options parsing helpers */ 2439 2440 /* 2441 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2442 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2443 * if negated option matches. 2444 * If the option or negated option matches, then *optsp is updated to 2445 * point to the first character after the option. 2446 */ 2447 int 2448 opt_flag(const char *opt, int allow_negate, const char **optsp) 2449 { 2450 size_t opt_len = strlen(opt); 2451 const char *opts = *optsp; 2452 int negate = 0; 2453 2454 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2455 opts += 3; 2456 negate = 1; 2457 } 2458 if (strncasecmp(opts, opt, opt_len) == 0) { 2459 *optsp = opts + opt_len; 2460 return negate ? 0 : 1; 2461 } 2462 return -1; 2463 } 2464 2465 char * 2466 opt_dequote(const char **sp, const char **errstrp) 2467 { 2468 const char *s = *sp; 2469 char *ret; 2470 size_t i; 2471 2472 *errstrp = NULL; 2473 if (*s != '"') { 2474 *errstrp = "missing start quote"; 2475 return NULL; 2476 } 2477 s++; 2478 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2479 *errstrp = "memory allocation failed"; 2480 return NULL; 2481 } 2482 for (i = 0; *s != '\0' && *s != '"';) { 2483 if (s[0] == '\\' && s[1] == '"') 2484 s++; 2485 ret[i++] = *s++; 2486 } 2487 if (*s == '\0') { 2488 *errstrp = "missing end quote"; 2489 free(ret); 2490 return NULL; 2491 } 2492 ret[i] = '\0'; 2493 s++; 2494 *sp = s; 2495 return ret; 2496 } 2497 2498 int 2499 opt_match(const char **opts, const char *term) 2500 { 2501 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2502 (*opts)[strlen(term)] == '=') { 2503 *opts += strlen(term) + 1; 2504 return 1; 2505 } 2506 return 0; 2507 } 2508 2509 void 2510 opt_array_append2(const char *file, const int line, const char *directive, 2511 char ***array, int **iarray, u_int *lp, const char *s, int i) 2512 { 2513 2514 if (*lp >= INT_MAX) 2515 fatal("%s line %d: Too many %s entries", file, line, directive); 2516 2517 if (iarray != NULL) { 2518 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2519 sizeof(**iarray)); 2520 (*iarray)[*lp] = i; 2521 } 2522 2523 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2524 (*array)[*lp] = xstrdup(s); 2525 (*lp)++; 2526 } 2527 2528 void 2529 opt_array_append(const char *file, const int line, const char *directive, 2530 char ***array, u_int *lp, const char *s) 2531 { 2532 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2533 } 2534 2535 sshsig_t 2536 ssh_signal(int signum, sshsig_t handler) 2537 { 2538 struct sigaction sa, osa; 2539 2540 /* mask all other signals while in handler */ 2541 memset(&sa, 0, sizeof(sa)); 2542 sa.sa_handler = handler; 2543 sigfillset(&sa.sa_mask); 2544 #if defined(SA_RESTART) && !defined(NO_SA_RESTART) 2545 if (signum != SIGALRM) 2546 sa.sa_flags = SA_RESTART; 2547 #endif 2548 if (sigaction(signum, &sa, &osa) == -1) { 2549 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2550 return SIG_ERR; 2551 } 2552 return osa.sa_handler; 2553 } 2554 2555 int 2556 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2557 { 2558 int devnull, ret = 0; 2559 2560 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2561 error_f("open %s: %s", _PATH_DEVNULL, 2562 strerror(errno)); 2563 return -1; 2564 } 2565 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2566 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2567 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2568 error_f("dup2: %s", strerror(errno)); 2569 ret = -1; 2570 } 2571 if (devnull > STDERR_FILENO) 2572 close(devnull); 2573 return ret; 2574 } 2575 2576 /* 2577 * Runs command in a subprocess with a minimal environment. 2578 * Returns pid on success, 0 on failure. 2579 * The child stdout and stderr maybe captured, left attached or sent to 2580 * /dev/null depending on the contents of flags. 2581 * "tag" is prepended to log messages. 2582 * NB. "command" is only used for logging; the actual command executed is 2583 * av[0]. 2584 */ 2585 pid_t 2586 subprocess(const char *tag, const char *command, 2587 int ac, char **av, FILE **child, u_int flags, 2588 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2589 { 2590 FILE *f = NULL; 2591 struct stat st; 2592 int fd, devnull, p[2], i; 2593 pid_t pid; 2594 char *cp, errmsg[512]; 2595 u_int nenv = 0; 2596 char **env = NULL; 2597 2598 /* If dropping privs, then must specify user and restore function */ 2599 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2600 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2601 return 0; 2602 } 2603 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2604 error("%s: no user for current uid", tag); 2605 return 0; 2606 } 2607 if (child != NULL) 2608 *child = NULL; 2609 2610 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2611 tag, command, pw->pw_name, flags); 2612 2613 /* Check consistency */ 2614 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2615 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2616 error_f("inconsistent flags"); 2617 return 0; 2618 } 2619 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2620 error_f("inconsistent flags/output"); 2621 return 0; 2622 } 2623 2624 /* 2625 * If executing an explicit binary, then verify the it exists 2626 * and appears safe-ish to execute 2627 */ 2628 if (!path_absolute(av[0])) { 2629 error("%s path is not absolute", tag); 2630 return 0; 2631 } 2632 if (drop_privs != NULL) 2633 drop_privs(pw); 2634 if (stat(av[0], &st) == -1) { 2635 error("Could not stat %s \"%s\": %s", tag, 2636 av[0], strerror(errno)); 2637 goto restore_return; 2638 } 2639 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2640 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2641 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2642 goto restore_return; 2643 } 2644 /* Prepare to keep the child's stdout if requested */ 2645 if (pipe(p) == -1) { 2646 error("%s: pipe: %s", tag, strerror(errno)); 2647 restore_return: 2648 if (restore_privs != NULL) 2649 restore_privs(); 2650 return 0; 2651 } 2652 if (restore_privs != NULL) 2653 restore_privs(); 2654 2655 switch ((pid = fork())) { 2656 case -1: /* error */ 2657 error("%s: fork: %s", tag, strerror(errno)); 2658 close(p[0]); 2659 close(p[1]); 2660 return 0; 2661 case 0: /* child */ 2662 /* Prepare a minimal environment for the child. */ 2663 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2664 nenv = 5; 2665 env = xcalloc(sizeof(*env), nenv); 2666 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2667 child_set_env(&env, &nenv, "USER", pw->pw_name); 2668 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2669 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2670 if ((cp = getenv("LANG")) != NULL) 2671 child_set_env(&env, &nenv, "LANG", cp); 2672 } 2673 2674 for (i = 1; i < NSIG; i++) 2675 ssh_signal(i, SIG_DFL); 2676 2677 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2678 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2679 strerror(errno)); 2680 _exit(1); 2681 } 2682 if (dup2(devnull, STDIN_FILENO) == -1) { 2683 error("%s: dup2: %s", tag, strerror(errno)); 2684 _exit(1); 2685 } 2686 2687 /* Set up stdout as requested; leave stderr in place for now. */ 2688 fd = -1; 2689 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2690 fd = p[1]; 2691 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2692 fd = devnull; 2693 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2694 error("%s: dup2: %s", tag, strerror(errno)); 2695 _exit(1); 2696 } 2697 closefrom(STDERR_FILENO + 1); 2698 2699 if (geteuid() == 0 && 2700 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2701 error("%s: initgroups(%s, %u): %s", tag, 2702 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2703 _exit(1); 2704 } 2705 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2706 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2707 strerror(errno)); 2708 _exit(1); 2709 } 2710 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2711 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2712 strerror(errno)); 2713 _exit(1); 2714 } 2715 /* stdin is pointed to /dev/null at this point */ 2716 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2717 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2718 error("%s: dup2: %s", tag, strerror(errno)); 2719 _exit(1); 2720 } 2721 if (env != NULL) 2722 execve(av[0], av, env); 2723 else 2724 execv(av[0], av); 2725 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2726 command, strerror(errno)); 2727 _exit(127); 2728 default: /* parent */ 2729 break; 2730 } 2731 2732 close(p[1]); 2733 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2734 close(p[0]); 2735 else if ((f = fdopen(p[0], "r")) == NULL) { 2736 error("%s: fdopen: %s", tag, strerror(errno)); 2737 close(p[0]); 2738 /* Don't leave zombie child */ 2739 kill(pid, SIGTERM); 2740 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2741 ; 2742 return 0; 2743 } 2744 /* Success */ 2745 debug3_f("%s pid %ld", tag, (long)pid); 2746 if (child != NULL) 2747 *child = f; 2748 return pid; 2749 } 2750 2751 const char * 2752 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2753 { 2754 size_t i, envlen; 2755 2756 envlen = strlen(env); 2757 for (i = 0; i < nenvs; i++) { 2758 if (strncmp(envs[i], env, envlen) == 0 && 2759 envs[i][envlen] == '=') { 2760 return envs[i] + envlen + 1; 2761 } 2762 } 2763 return NULL; 2764 } 2765