1 /* $OpenBSD: misc.c,v 1.174 2022/02/11 00:43:56 dtucker Exp $ */ 2 /* 3 * Copyright (c) 2000 Markus Friedl. All rights reserved. 4 * Copyright (c) 2005-2020 Damien Miller. All rights reserved. 5 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 21 #include "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 /* The common case: only accept colon as delimiter. */ 723 char * 724 hpdelim(char **cp) 725 { 726 char *r, delim = '\0'; 727 728 r = hpdelim2(cp, &delim); 729 if (delim == '/') 730 return NULL; 731 return r; 732 } 733 734 char * 735 cleanhostname(char *host) 736 { 737 if (*host == '[' && host[strlen(host) - 1] == ']') { 738 host[strlen(host) - 1] = '\0'; 739 return (host + 1); 740 } else 741 return host; 742 } 743 744 char * 745 colon(char *cp) 746 { 747 int flag = 0; 748 749 if (*cp == ':') /* Leading colon is part of file name. */ 750 return NULL; 751 if (*cp == '[') 752 flag = 1; 753 754 for (; *cp; ++cp) { 755 if (*cp == '@' && *(cp+1) == '[') 756 flag = 1; 757 if (*cp == ']' && *(cp+1) == ':' && flag) 758 return (cp+1); 759 if (*cp == ':' && !flag) 760 return (cp); 761 if (*cp == '/') 762 return NULL; 763 } 764 return NULL; 765 } 766 767 /* 768 * Parse a [user@]host:[path] string. 769 * Caller must free returned user, host and path. 770 * Any of the pointer return arguments may be NULL (useful for syntax checking). 771 * If user was not specified then *userp will be set to NULL. 772 * If host was not specified then *hostp will be set to NULL. 773 * If path was not specified then *pathp will be set to ".". 774 * Returns 0 on success, -1 on failure. 775 */ 776 int 777 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 778 { 779 char *user = NULL, *host = NULL, *path = NULL; 780 char *sdup, *tmp; 781 int ret = -1; 782 783 if (userp != NULL) 784 *userp = NULL; 785 if (hostp != NULL) 786 *hostp = NULL; 787 if (pathp != NULL) 788 *pathp = NULL; 789 790 sdup = xstrdup(s); 791 792 /* Check for remote syntax: [user@]host:[path] */ 793 if ((tmp = colon(sdup)) == NULL) 794 goto out; 795 796 /* Extract optional path */ 797 *tmp++ = '\0'; 798 if (*tmp == '\0') 799 tmp = "."; 800 path = xstrdup(tmp); 801 802 /* Extract optional user and mandatory host */ 803 tmp = strrchr(sdup, '@'); 804 if (tmp != NULL) { 805 *tmp++ = '\0'; 806 host = xstrdup(cleanhostname(tmp)); 807 if (*sdup != '\0') 808 user = xstrdup(sdup); 809 } else { 810 host = xstrdup(cleanhostname(sdup)); 811 user = NULL; 812 } 813 814 /* Success */ 815 if (userp != NULL) { 816 *userp = user; 817 user = NULL; 818 } 819 if (hostp != NULL) { 820 *hostp = host; 821 host = NULL; 822 } 823 if (pathp != NULL) { 824 *pathp = path; 825 path = NULL; 826 } 827 ret = 0; 828 out: 829 free(sdup); 830 free(user); 831 free(host); 832 free(path); 833 return ret; 834 } 835 836 /* 837 * Parse a [user@]host[:port] string. 838 * Caller must free returned user and host. 839 * Any of the pointer return arguments may be NULL (useful for syntax checking). 840 * If user was not specified then *userp will be set to NULL. 841 * If port was not specified then *portp will be -1. 842 * Returns 0 on success, -1 on failure. 843 */ 844 int 845 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 846 { 847 char *sdup, *cp, *tmp; 848 char *user = NULL, *host = NULL; 849 int port = -1, ret = -1; 850 851 if (userp != NULL) 852 *userp = NULL; 853 if (hostp != NULL) 854 *hostp = NULL; 855 if (portp != NULL) 856 *portp = -1; 857 858 if ((sdup = tmp = strdup(s)) == NULL) 859 return -1; 860 /* Extract optional username */ 861 if ((cp = strrchr(tmp, '@')) != NULL) { 862 *cp = '\0'; 863 if (*tmp == '\0') 864 goto out; 865 if ((user = strdup(tmp)) == NULL) 866 goto out; 867 tmp = cp + 1; 868 } 869 /* Extract mandatory hostname */ 870 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 871 goto out; 872 host = xstrdup(cleanhostname(cp)); 873 /* Convert and verify optional port */ 874 if (tmp != NULL && *tmp != '\0') { 875 if ((port = a2port(tmp)) <= 0) 876 goto out; 877 } 878 /* Success */ 879 if (userp != NULL) { 880 *userp = user; 881 user = NULL; 882 } 883 if (hostp != NULL) { 884 *hostp = host; 885 host = NULL; 886 } 887 if (portp != NULL) 888 *portp = port; 889 ret = 0; 890 out: 891 free(sdup); 892 free(user); 893 free(host); 894 return ret; 895 } 896 897 /* 898 * Converts a two-byte hex string to decimal. 899 * Returns the decimal value or -1 for invalid input. 900 */ 901 static int 902 hexchar(const char *s) 903 { 904 unsigned char result[2]; 905 int i; 906 907 for (i = 0; i < 2; i++) { 908 if (s[i] >= '0' && s[i] <= '9') 909 result[i] = (unsigned char)(s[i] - '0'); 910 else if (s[i] >= 'a' && s[i] <= 'f') 911 result[i] = (unsigned char)(s[i] - 'a') + 10; 912 else if (s[i] >= 'A' && s[i] <= 'F') 913 result[i] = (unsigned char)(s[i] - 'A') + 10; 914 else 915 return -1; 916 } 917 return (result[0] << 4) | result[1]; 918 } 919 920 /* 921 * Decode an url-encoded string. 922 * Returns a newly allocated string on success or NULL on failure. 923 */ 924 static char * 925 urldecode(const char *src) 926 { 927 char *ret, *dst; 928 int ch; 929 930 ret = xmalloc(strlen(src) + 1); 931 for (dst = ret; *src != '\0'; src++) { 932 switch (*src) { 933 case '+': 934 *dst++ = ' '; 935 break; 936 case '%': 937 if (!isxdigit((unsigned char)src[1]) || 938 !isxdigit((unsigned char)src[2]) || 939 (ch = hexchar(src + 1)) == -1) { 940 free(ret); 941 return NULL; 942 } 943 *dst++ = ch; 944 src += 2; 945 break; 946 default: 947 *dst++ = *src; 948 break; 949 } 950 } 951 *dst = '\0'; 952 953 return ret; 954 } 955 956 /* 957 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 958 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 959 * Either user or path may be url-encoded (but not host or port). 960 * Caller must free returned user, host and path. 961 * Any of the pointer return arguments may be NULL (useful for syntax checking) 962 * but the scheme must always be specified. 963 * If user was not specified then *userp will be set to NULL. 964 * If port was not specified then *portp will be -1. 965 * If path was not specified then *pathp will be set to NULL. 966 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 967 */ 968 int 969 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 970 int *portp, char **pathp) 971 { 972 char *uridup, *cp, *tmp, ch; 973 char *user = NULL, *host = NULL, *path = NULL; 974 int port = -1, ret = -1; 975 size_t len; 976 977 len = strlen(scheme); 978 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 979 return 1; 980 uri += len + 3; 981 982 if (userp != NULL) 983 *userp = NULL; 984 if (hostp != NULL) 985 *hostp = NULL; 986 if (portp != NULL) 987 *portp = -1; 988 if (pathp != NULL) 989 *pathp = NULL; 990 991 uridup = tmp = xstrdup(uri); 992 993 /* Extract optional ssh-info (username + connection params) */ 994 if ((cp = strchr(tmp, '@')) != NULL) { 995 char *delim; 996 997 *cp = '\0'; 998 /* Extract username and connection params */ 999 if ((delim = strchr(tmp, ';')) != NULL) { 1000 /* Just ignore connection params for now */ 1001 *delim = '\0'; 1002 } 1003 if (*tmp == '\0') { 1004 /* Empty username */ 1005 goto out; 1006 } 1007 if ((user = urldecode(tmp)) == NULL) 1008 goto out; 1009 tmp = cp + 1; 1010 } 1011 1012 /* Extract mandatory hostname */ 1013 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 1014 goto out; 1015 host = xstrdup(cleanhostname(cp)); 1016 if (!valid_domain(host, 0, NULL)) 1017 goto out; 1018 1019 if (tmp != NULL && *tmp != '\0') { 1020 if (ch == ':') { 1021 /* Convert and verify port. */ 1022 if ((cp = strchr(tmp, '/')) != NULL) 1023 *cp = '\0'; 1024 if ((port = a2port(tmp)) <= 0) 1025 goto out; 1026 tmp = cp ? cp + 1 : NULL; 1027 } 1028 if (tmp != NULL && *tmp != '\0') { 1029 /* Extract optional path */ 1030 if ((path = urldecode(tmp)) == NULL) 1031 goto out; 1032 } 1033 } 1034 1035 /* Success */ 1036 if (userp != NULL) { 1037 *userp = user; 1038 user = NULL; 1039 } 1040 if (hostp != NULL) { 1041 *hostp = host; 1042 host = NULL; 1043 } 1044 if (portp != NULL) 1045 *portp = port; 1046 if (pathp != NULL) { 1047 *pathp = path; 1048 path = NULL; 1049 } 1050 ret = 0; 1051 out: 1052 free(uridup); 1053 free(user); 1054 free(host); 1055 free(path); 1056 return ret; 1057 } 1058 1059 /* function to assist building execv() arguments */ 1060 void 1061 addargs(arglist *args, char *fmt, ...) 1062 { 1063 va_list ap; 1064 char *cp; 1065 u_int nalloc; 1066 int r; 1067 1068 va_start(ap, fmt); 1069 r = vasprintf(&cp, fmt, ap); 1070 va_end(ap); 1071 if (r == -1) 1072 fatal("addargs: argument too long"); 1073 1074 nalloc = args->nalloc; 1075 if (args->list == NULL) { 1076 nalloc = 32; 1077 args->num = 0; 1078 } else if (args->num+2 >= nalloc) 1079 nalloc *= 2; 1080 1081 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 1082 args->nalloc = nalloc; 1083 args->list[args->num++] = cp; 1084 args->list[args->num] = NULL; 1085 } 1086 1087 void 1088 replacearg(arglist *args, u_int which, char *fmt, ...) 1089 { 1090 va_list ap; 1091 char *cp; 1092 int r; 1093 1094 va_start(ap, fmt); 1095 r = vasprintf(&cp, fmt, ap); 1096 va_end(ap); 1097 if (r == -1) 1098 fatal("replacearg: argument too long"); 1099 1100 if (which >= args->num) 1101 fatal("replacearg: tried to replace invalid arg %d >= %d", 1102 which, args->num); 1103 free(args->list[which]); 1104 args->list[which] = cp; 1105 } 1106 1107 void 1108 freeargs(arglist *args) 1109 { 1110 u_int i; 1111 1112 if (args->list != NULL) { 1113 for (i = 0; i < args->num; i++) 1114 free(args->list[i]); 1115 free(args->list); 1116 args->nalloc = args->num = 0; 1117 args->list = NULL; 1118 } 1119 } 1120 1121 /* 1122 * Expands tildes in the file name. Returns data allocated by xmalloc. 1123 * Warning: this calls getpw*. 1124 */ 1125 int 1126 tilde_expand(const char *filename, uid_t uid, char **retp) 1127 { 1128 char *ocopy = NULL, *copy, *s = NULL; 1129 const char *path = NULL, *user = NULL; 1130 struct passwd *pw; 1131 size_t len; 1132 int ret = -1, r, slash; 1133 1134 *retp = NULL; 1135 if (*filename != '~') { 1136 *retp = xstrdup(filename); 1137 return 0; 1138 } 1139 ocopy = copy = xstrdup(filename + 1); 1140 1141 if (*copy == '\0') /* ~ */ 1142 path = NULL; 1143 else if (*copy == '/') { 1144 copy += strspn(copy, "/"); 1145 if (*copy == '\0') 1146 path = NULL; /* ~/ */ 1147 else 1148 path = copy; /* ~/path */ 1149 } else { 1150 user = copy; 1151 if ((path = strchr(copy, '/')) != NULL) { 1152 copy[path - copy] = '\0'; 1153 path++; 1154 path += strspn(path, "/"); 1155 if (*path == '\0') /* ~user/ */ 1156 path = NULL; 1157 /* else ~user/path */ 1158 } 1159 /* else ~user */ 1160 } 1161 if (user != NULL) { 1162 if ((pw = getpwnam(user)) == NULL) { 1163 error_f("No such user %s", user); 1164 goto out; 1165 } 1166 } else if ((pw = getpwuid(uid)) == NULL) { 1167 error_f("No such uid %ld", (long)uid); 1168 goto out; 1169 } 1170 1171 /* Make sure directory has a trailing '/' */ 1172 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1173 1174 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1175 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1176 error_f("xasprintf failed"); 1177 goto out; 1178 } 1179 if (r >= PATH_MAX) { 1180 error_f("Path too long"); 1181 goto out; 1182 } 1183 /* success */ 1184 ret = 0; 1185 *retp = s; 1186 s = NULL; 1187 out: 1188 free(s); 1189 free(ocopy); 1190 return ret; 1191 } 1192 1193 char * 1194 tilde_expand_filename(const char *filename, uid_t uid) 1195 { 1196 char *ret; 1197 1198 if (tilde_expand(filename, uid, &ret) != 0) 1199 cleanup_exit(255); 1200 return ret; 1201 } 1202 1203 /* 1204 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1205 * substitutions. A number of escapes may be specified as 1206 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1207 * by a NULL escape_char. Returns replaced string in memory allocated by 1208 * xmalloc which the caller must free. 1209 */ 1210 static char * 1211 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1212 const char *string, va_list ap) 1213 { 1214 #define EXPAND_MAX_KEYS 16 1215 u_int num_keys = 0, i; 1216 struct { 1217 const char *key; 1218 const char *repl; 1219 } keys[EXPAND_MAX_KEYS]; 1220 struct sshbuf *buf; 1221 int r, missingvar = 0; 1222 char *ret = NULL, *var, *varend, *val; 1223 size_t len; 1224 1225 if ((buf = sshbuf_new()) == NULL) 1226 fatal_f("sshbuf_new failed"); 1227 if (parseerror == NULL) 1228 fatal_f("null parseerror arg"); 1229 *parseerror = 1; 1230 1231 /* Gather keys if we're doing percent expansion. */ 1232 if (percent) { 1233 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1234 keys[num_keys].key = va_arg(ap, char *); 1235 if (keys[num_keys].key == NULL) 1236 break; 1237 keys[num_keys].repl = va_arg(ap, char *); 1238 if (keys[num_keys].repl == NULL) { 1239 fatal_f("NULL replacement for token %s", 1240 keys[num_keys].key); 1241 } 1242 } 1243 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1244 fatal_f("too many keys"); 1245 if (num_keys == 0) 1246 fatal_f("percent expansion without token list"); 1247 } 1248 1249 /* Expand string */ 1250 for (i = 0; *string != '\0'; string++) { 1251 /* Optionally process ${ENVIRONMENT} expansions. */ 1252 if (dollar && string[0] == '$' && string[1] == '{') { 1253 string += 2; /* skip over '${' */ 1254 if ((varend = strchr(string, '}')) == NULL) { 1255 error_f("environment variable '%s' missing " 1256 "closing '}'", string); 1257 goto out; 1258 } 1259 len = varend - string; 1260 if (len == 0) { 1261 error_f("zero-length environment variable"); 1262 goto out; 1263 } 1264 var = xmalloc(len + 1); 1265 (void)strlcpy(var, string, len + 1); 1266 if ((val = getenv(var)) == NULL) { 1267 error_f("env var ${%s} has no value", var); 1268 missingvar = 1; 1269 } else { 1270 debug3_f("expand ${%s} -> '%s'", var, val); 1271 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1272 fatal_fr(r, "sshbuf_put ${}"); 1273 } 1274 free(var); 1275 string += len; 1276 continue; 1277 } 1278 1279 /* 1280 * Process percent expansions if we have a list of TOKENs. 1281 * If we're not doing percent expansion everything just gets 1282 * appended here. 1283 */ 1284 if (*string != '%' || !percent) { 1285 append: 1286 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1287 fatal_fr(r, "sshbuf_put_u8 %%"); 1288 continue; 1289 } 1290 string++; 1291 /* %% case */ 1292 if (*string == '%') 1293 goto append; 1294 if (*string == '\0') { 1295 error_f("invalid format"); 1296 goto out; 1297 } 1298 for (i = 0; i < num_keys; i++) { 1299 if (strchr(keys[i].key, *string) != NULL) { 1300 if ((r = sshbuf_put(buf, keys[i].repl, 1301 strlen(keys[i].repl))) != 0) 1302 fatal_fr(r, "sshbuf_put %%-repl"); 1303 break; 1304 } 1305 } 1306 if (i >= num_keys) { 1307 error_f("unknown key %%%c", *string); 1308 goto out; 1309 } 1310 } 1311 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1312 fatal_f("sshbuf_dup_string failed"); 1313 *parseerror = 0; 1314 out: 1315 sshbuf_free(buf); 1316 return *parseerror ? NULL : ret; 1317 #undef EXPAND_MAX_KEYS 1318 } 1319 1320 /* 1321 * Expand only environment variables. 1322 * Note that although this function is variadic like the other similar 1323 * functions, any such arguments will be unused. 1324 */ 1325 1326 char * 1327 dollar_expand(int *parseerr, const char *string, ...) 1328 { 1329 char *ret; 1330 int err; 1331 va_list ap; 1332 1333 va_start(ap, string); 1334 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1335 va_end(ap); 1336 if (parseerr != NULL) 1337 *parseerr = err; 1338 return ret; 1339 } 1340 1341 /* 1342 * Returns expanded string or NULL if a specified environment variable is 1343 * not defined, or calls fatal if the string is invalid. 1344 */ 1345 char * 1346 percent_expand(const char *string, ...) 1347 { 1348 char *ret; 1349 int err; 1350 va_list ap; 1351 1352 va_start(ap, string); 1353 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1354 va_end(ap); 1355 if (err) 1356 fatal_f("failed"); 1357 return ret; 1358 } 1359 1360 /* 1361 * Returns expanded string or NULL if a specified environment variable is 1362 * not defined, or calls fatal if the string is invalid. 1363 */ 1364 char * 1365 percent_dollar_expand(const char *string, ...) 1366 { 1367 char *ret; 1368 int err; 1369 va_list ap; 1370 1371 va_start(ap, string); 1372 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1373 va_end(ap); 1374 if (err) 1375 fatal_f("failed"); 1376 return ret; 1377 } 1378 1379 int 1380 tun_open(int tun, int mode, char **ifname) 1381 { 1382 #if defined(CUSTOM_SYS_TUN_OPEN) 1383 return (sys_tun_open(tun, mode, ifname)); 1384 #elif defined(SSH_TUN_OPENBSD) 1385 struct ifreq ifr; 1386 char name[100]; 1387 int fd = -1, sock; 1388 const char *tunbase = "tun"; 1389 1390 if (ifname != NULL) 1391 *ifname = NULL; 1392 1393 if (mode == SSH_TUNMODE_ETHERNET) 1394 tunbase = "tap"; 1395 1396 /* Open the tunnel device */ 1397 if (tun <= SSH_TUNID_MAX) { 1398 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1399 fd = open(name, O_RDWR); 1400 } else if (tun == SSH_TUNID_ANY) { 1401 for (tun = 100; tun >= 0; tun--) { 1402 snprintf(name, sizeof(name), "/dev/%s%d", 1403 tunbase, tun); 1404 if ((fd = open(name, O_RDWR)) >= 0) 1405 break; 1406 } 1407 } else { 1408 debug_f("invalid tunnel %u", tun); 1409 return -1; 1410 } 1411 1412 if (fd == -1) { 1413 debug_f("%s open: %s", name, strerror(errno)); 1414 return -1; 1415 } 1416 1417 debug_f("%s mode %d fd %d", name, mode, fd); 1418 1419 /* Bring interface up if it is not already */ 1420 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1421 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1422 goto failed; 1423 1424 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1425 debug_f("get interface %s flags: %s", ifr.ifr_name, 1426 strerror(errno)); 1427 goto failed; 1428 } 1429 1430 if (!(ifr.ifr_flags & IFF_UP)) { 1431 ifr.ifr_flags |= IFF_UP; 1432 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1433 debug_f("activate interface %s: %s", ifr.ifr_name, 1434 strerror(errno)); 1435 goto failed; 1436 } 1437 } 1438 1439 if (ifname != NULL) 1440 *ifname = xstrdup(ifr.ifr_name); 1441 1442 close(sock); 1443 return fd; 1444 1445 failed: 1446 if (fd >= 0) 1447 close(fd); 1448 if (sock >= 0) 1449 close(sock); 1450 return -1; 1451 #else 1452 error("Tunnel interfaces are not supported on this platform"); 1453 return (-1); 1454 #endif 1455 } 1456 1457 void 1458 sanitise_stdfd(void) 1459 { 1460 int nullfd, dupfd; 1461 1462 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1463 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1464 strerror(errno)); 1465 exit(1); 1466 } 1467 while (++dupfd <= STDERR_FILENO) { 1468 /* Only populate closed fds. */ 1469 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1470 if (dup2(nullfd, dupfd) == -1) { 1471 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1472 exit(1); 1473 } 1474 } 1475 } 1476 if (nullfd > STDERR_FILENO) 1477 close(nullfd); 1478 } 1479 1480 char * 1481 tohex(const void *vp, size_t l) 1482 { 1483 const u_char *p = (const u_char *)vp; 1484 char b[3], *r; 1485 size_t i, hl; 1486 1487 if (l > 65536) 1488 return xstrdup("tohex: length > 65536"); 1489 1490 hl = l * 2 + 1; 1491 r = xcalloc(1, hl); 1492 for (i = 0; i < l; i++) { 1493 snprintf(b, sizeof(b), "%02x", p[i]); 1494 strlcat(r, b, hl); 1495 } 1496 return (r); 1497 } 1498 1499 /* 1500 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1501 * then the separator 'sep' will be prepended before the formatted arguments. 1502 * Extended strings are heap allocated. 1503 */ 1504 void 1505 xextendf(char **sp, const char *sep, const char *fmt, ...) 1506 { 1507 va_list ap; 1508 char *tmp1, *tmp2; 1509 1510 va_start(ap, fmt); 1511 xvasprintf(&tmp1, fmt, ap); 1512 va_end(ap); 1513 1514 if (*sp == NULL || **sp == '\0') { 1515 free(*sp); 1516 *sp = tmp1; 1517 return; 1518 } 1519 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1520 free(tmp1); 1521 free(*sp); 1522 *sp = tmp2; 1523 } 1524 1525 1526 u_int64_t 1527 get_u64(const void *vp) 1528 { 1529 const u_char *p = (const u_char *)vp; 1530 u_int64_t v; 1531 1532 v = (u_int64_t)p[0] << 56; 1533 v |= (u_int64_t)p[1] << 48; 1534 v |= (u_int64_t)p[2] << 40; 1535 v |= (u_int64_t)p[3] << 32; 1536 v |= (u_int64_t)p[4] << 24; 1537 v |= (u_int64_t)p[5] << 16; 1538 v |= (u_int64_t)p[6] << 8; 1539 v |= (u_int64_t)p[7]; 1540 1541 return (v); 1542 } 1543 1544 u_int32_t 1545 get_u32(const void *vp) 1546 { 1547 const u_char *p = (const u_char *)vp; 1548 u_int32_t v; 1549 1550 v = (u_int32_t)p[0] << 24; 1551 v |= (u_int32_t)p[1] << 16; 1552 v |= (u_int32_t)p[2] << 8; 1553 v |= (u_int32_t)p[3]; 1554 1555 return (v); 1556 } 1557 1558 u_int32_t 1559 get_u32_le(const void *vp) 1560 { 1561 const u_char *p = (const u_char *)vp; 1562 u_int32_t v; 1563 1564 v = (u_int32_t)p[0]; 1565 v |= (u_int32_t)p[1] << 8; 1566 v |= (u_int32_t)p[2] << 16; 1567 v |= (u_int32_t)p[3] << 24; 1568 1569 return (v); 1570 } 1571 1572 u_int16_t 1573 get_u16(const void *vp) 1574 { 1575 const u_char *p = (const u_char *)vp; 1576 u_int16_t v; 1577 1578 v = (u_int16_t)p[0] << 8; 1579 v |= (u_int16_t)p[1]; 1580 1581 return (v); 1582 } 1583 1584 void 1585 put_u64(void *vp, u_int64_t v) 1586 { 1587 u_char *p = (u_char *)vp; 1588 1589 p[0] = (u_char)(v >> 56) & 0xff; 1590 p[1] = (u_char)(v >> 48) & 0xff; 1591 p[2] = (u_char)(v >> 40) & 0xff; 1592 p[3] = (u_char)(v >> 32) & 0xff; 1593 p[4] = (u_char)(v >> 24) & 0xff; 1594 p[5] = (u_char)(v >> 16) & 0xff; 1595 p[6] = (u_char)(v >> 8) & 0xff; 1596 p[7] = (u_char)v & 0xff; 1597 } 1598 1599 void 1600 put_u32(void *vp, u_int32_t v) 1601 { 1602 u_char *p = (u_char *)vp; 1603 1604 p[0] = (u_char)(v >> 24) & 0xff; 1605 p[1] = (u_char)(v >> 16) & 0xff; 1606 p[2] = (u_char)(v >> 8) & 0xff; 1607 p[3] = (u_char)v & 0xff; 1608 } 1609 1610 void 1611 put_u32_le(void *vp, u_int32_t v) 1612 { 1613 u_char *p = (u_char *)vp; 1614 1615 p[0] = (u_char)v & 0xff; 1616 p[1] = (u_char)(v >> 8) & 0xff; 1617 p[2] = (u_char)(v >> 16) & 0xff; 1618 p[3] = (u_char)(v >> 24) & 0xff; 1619 } 1620 1621 void 1622 put_u16(void *vp, u_int16_t v) 1623 { 1624 u_char *p = (u_char *)vp; 1625 1626 p[0] = (u_char)(v >> 8) & 0xff; 1627 p[1] = (u_char)v & 0xff; 1628 } 1629 1630 void 1631 ms_subtract_diff(struct timeval *start, int *ms) 1632 { 1633 struct timeval diff, finish; 1634 1635 monotime_tv(&finish); 1636 timersub(&finish, start, &diff); 1637 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1638 } 1639 1640 void 1641 ms_to_timespec(struct timespec *ts, int ms) 1642 { 1643 if (ms < 0) 1644 ms = 0; 1645 ts->tv_sec = ms / 1000; 1646 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1647 } 1648 1649 void 1650 monotime_ts(struct timespec *ts) 1651 { 1652 struct timeval tv; 1653 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \ 1654 defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME)) 1655 static int gettime_failed = 0; 1656 1657 if (!gettime_failed) { 1658 # ifdef CLOCK_BOOTTIME 1659 if (clock_gettime(CLOCK_BOOTTIME, ts) == 0) 1660 return; 1661 # endif /* CLOCK_BOOTTIME */ 1662 # ifdef CLOCK_MONOTONIC 1663 if (clock_gettime(CLOCK_MONOTONIC, ts) == 0) 1664 return; 1665 # endif /* CLOCK_MONOTONIC */ 1666 # ifdef CLOCK_REALTIME 1667 /* Not monotonic, but we're almost out of options here. */ 1668 if (clock_gettime(CLOCK_REALTIME, ts) == 0) 1669 return; 1670 # endif /* CLOCK_REALTIME */ 1671 debug3("clock_gettime: %s", strerror(errno)); 1672 gettime_failed = 1; 1673 } 1674 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */ 1675 gettimeofday(&tv, NULL); 1676 ts->tv_sec = tv.tv_sec; 1677 ts->tv_nsec = (long)tv.tv_usec * 1000; 1678 } 1679 1680 void 1681 monotime_tv(struct timeval *tv) 1682 { 1683 struct timespec ts; 1684 1685 monotime_ts(&ts); 1686 tv->tv_sec = ts.tv_sec; 1687 tv->tv_usec = ts.tv_nsec / 1000; 1688 } 1689 1690 time_t 1691 monotime(void) 1692 { 1693 struct timespec ts; 1694 1695 monotime_ts(&ts); 1696 return ts.tv_sec; 1697 } 1698 1699 double 1700 monotime_double(void) 1701 { 1702 struct timespec ts; 1703 1704 monotime_ts(&ts); 1705 return ts.tv_sec + ((double)ts.tv_nsec / 1000000000); 1706 } 1707 1708 void 1709 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1710 { 1711 bw->buflen = buflen; 1712 bw->rate = kbps; 1713 bw->thresh = buflen; 1714 bw->lamt = 0; 1715 timerclear(&bw->bwstart); 1716 timerclear(&bw->bwend); 1717 } 1718 1719 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1720 void 1721 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1722 { 1723 u_int64_t waitlen; 1724 struct timespec ts, rm; 1725 1726 bw->lamt += read_len; 1727 if (!timerisset(&bw->bwstart)) { 1728 monotime_tv(&bw->bwstart); 1729 return; 1730 } 1731 if (bw->lamt < bw->thresh) 1732 return; 1733 1734 monotime_tv(&bw->bwend); 1735 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1736 if (!timerisset(&bw->bwend)) 1737 return; 1738 1739 bw->lamt *= 8; 1740 waitlen = (double)1000000L * bw->lamt / bw->rate; 1741 1742 bw->bwstart.tv_sec = waitlen / 1000000L; 1743 bw->bwstart.tv_usec = waitlen % 1000000L; 1744 1745 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1746 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1747 1748 /* Adjust the wait time */ 1749 if (bw->bwend.tv_sec) { 1750 bw->thresh /= 2; 1751 if (bw->thresh < bw->buflen / 4) 1752 bw->thresh = bw->buflen / 4; 1753 } else if (bw->bwend.tv_usec < 10000) { 1754 bw->thresh *= 2; 1755 if (bw->thresh > bw->buflen * 8) 1756 bw->thresh = bw->buflen * 8; 1757 } 1758 1759 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1760 while (nanosleep(&ts, &rm) == -1) { 1761 if (errno != EINTR) 1762 break; 1763 ts = rm; 1764 } 1765 } 1766 1767 bw->lamt = 0; 1768 monotime_tv(&bw->bwstart); 1769 } 1770 1771 /* Make a template filename for mk[sd]temp() */ 1772 void 1773 mktemp_proto(char *s, size_t len) 1774 { 1775 const char *tmpdir; 1776 int r; 1777 1778 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1779 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1780 if (r > 0 && (size_t)r < len) 1781 return; 1782 } 1783 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1784 if (r < 0 || (size_t)r >= len) 1785 fatal_f("template string too short"); 1786 } 1787 1788 static const struct { 1789 const char *name; 1790 int value; 1791 } ipqos[] = { 1792 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1793 { "af11", IPTOS_DSCP_AF11 }, 1794 { "af12", IPTOS_DSCP_AF12 }, 1795 { "af13", IPTOS_DSCP_AF13 }, 1796 { "af21", IPTOS_DSCP_AF21 }, 1797 { "af22", IPTOS_DSCP_AF22 }, 1798 { "af23", IPTOS_DSCP_AF23 }, 1799 { "af31", IPTOS_DSCP_AF31 }, 1800 { "af32", IPTOS_DSCP_AF32 }, 1801 { "af33", IPTOS_DSCP_AF33 }, 1802 { "af41", IPTOS_DSCP_AF41 }, 1803 { "af42", IPTOS_DSCP_AF42 }, 1804 { "af43", IPTOS_DSCP_AF43 }, 1805 { "cs0", IPTOS_DSCP_CS0 }, 1806 { "cs1", IPTOS_DSCP_CS1 }, 1807 { "cs2", IPTOS_DSCP_CS2 }, 1808 { "cs3", IPTOS_DSCP_CS3 }, 1809 { "cs4", IPTOS_DSCP_CS4 }, 1810 { "cs5", IPTOS_DSCP_CS5 }, 1811 { "cs6", IPTOS_DSCP_CS6 }, 1812 { "cs7", IPTOS_DSCP_CS7 }, 1813 { "ef", IPTOS_DSCP_EF }, 1814 { "le", IPTOS_DSCP_LE }, 1815 { "lowdelay", IPTOS_LOWDELAY }, 1816 { "throughput", IPTOS_THROUGHPUT }, 1817 { "reliability", IPTOS_RELIABILITY }, 1818 { NULL, -1 } 1819 }; 1820 1821 int 1822 parse_ipqos(const char *cp) 1823 { 1824 u_int i; 1825 char *ep; 1826 long val; 1827 1828 if (cp == NULL) 1829 return -1; 1830 for (i = 0; ipqos[i].name != NULL; i++) { 1831 if (strcasecmp(cp, ipqos[i].name) == 0) 1832 return ipqos[i].value; 1833 } 1834 /* Try parsing as an integer */ 1835 val = strtol(cp, &ep, 0); 1836 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1837 return -1; 1838 return val; 1839 } 1840 1841 const char * 1842 iptos2str(int iptos) 1843 { 1844 int i; 1845 static char iptos_str[sizeof "0xff"]; 1846 1847 for (i = 0; ipqos[i].name != NULL; i++) { 1848 if (ipqos[i].value == iptos) 1849 return ipqos[i].name; 1850 } 1851 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1852 return iptos_str; 1853 } 1854 1855 void 1856 lowercase(char *s) 1857 { 1858 for (; *s; s++) 1859 *s = tolower((u_char)*s); 1860 } 1861 1862 int 1863 unix_listener(const char *path, int backlog, int unlink_first) 1864 { 1865 struct sockaddr_un sunaddr; 1866 int saved_errno, sock; 1867 1868 memset(&sunaddr, 0, sizeof(sunaddr)); 1869 sunaddr.sun_family = AF_UNIX; 1870 if (strlcpy(sunaddr.sun_path, path, 1871 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1872 error_f("path \"%s\" too long for Unix domain socket", path); 1873 errno = ENAMETOOLONG; 1874 return -1; 1875 } 1876 1877 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1878 if (sock == -1) { 1879 saved_errno = errno; 1880 error_f("socket: %.100s", strerror(errno)); 1881 errno = saved_errno; 1882 return -1; 1883 } 1884 if (unlink_first == 1) { 1885 if (unlink(path) != 0 && errno != ENOENT) 1886 error("unlink(%s): %.100s", path, strerror(errno)); 1887 } 1888 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1889 saved_errno = errno; 1890 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1891 close(sock); 1892 errno = saved_errno; 1893 return -1; 1894 } 1895 if (listen(sock, backlog) == -1) { 1896 saved_errno = errno; 1897 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1898 close(sock); 1899 unlink(path); 1900 errno = saved_errno; 1901 return -1; 1902 } 1903 return sock; 1904 } 1905 1906 void 1907 sock_set_v6only(int s) 1908 { 1909 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__) 1910 int on = 1; 1911 1912 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s); 1913 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) 1914 error("setsockopt IPV6_V6ONLY: %s", strerror(errno)); 1915 #endif 1916 } 1917 1918 /* 1919 * Compares two strings that maybe be NULL. Returns non-zero if strings 1920 * are both NULL or are identical, returns zero otherwise. 1921 */ 1922 static int 1923 strcmp_maybe_null(const char *a, const char *b) 1924 { 1925 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1926 return 0; 1927 if (a != NULL && strcmp(a, b) != 0) 1928 return 0; 1929 return 1; 1930 } 1931 1932 /* 1933 * Compare two forwards, returning non-zero if they are identical or 1934 * zero otherwise. 1935 */ 1936 int 1937 forward_equals(const struct Forward *a, const struct Forward *b) 1938 { 1939 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1940 return 0; 1941 if (a->listen_port != b->listen_port) 1942 return 0; 1943 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1944 return 0; 1945 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1946 return 0; 1947 if (a->connect_port != b->connect_port) 1948 return 0; 1949 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1950 return 0; 1951 /* allocated_port and handle are not checked */ 1952 return 1; 1953 } 1954 1955 /* returns 1 if process is already daemonized, 0 otherwise */ 1956 int 1957 daemonized(void) 1958 { 1959 int fd; 1960 1961 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1962 close(fd); 1963 return 0; /* have controlling terminal */ 1964 } 1965 if (getppid() != 1) 1966 return 0; /* parent is not init */ 1967 if (getsid(0) != getpid()) 1968 return 0; /* not session leader */ 1969 debug3("already daemonized"); 1970 return 1; 1971 } 1972 1973 /* 1974 * Splits 's' into an argument vector. Handles quoted string and basic 1975 * escape characters (\\, \", \'). Caller must free the argument vector 1976 * and its members. 1977 */ 1978 int 1979 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1980 { 1981 int r = SSH_ERR_INTERNAL_ERROR; 1982 int argc = 0, quote, i, j; 1983 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1984 1985 *argvp = NULL; 1986 *argcp = 0; 1987 1988 for (i = 0; s[i] != '\0'; i++) { 1989 /* Skip leading whitespace */ 1990 if (s[i] == ' ' || s[i] == '\t') 1991 continue; 1992 if (terminate_on_comment && s[i] == '#') 1993 break; 1994 /* Start of a token */ 1995 quote = 0; 1996 1997 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1998 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1999 argv[argc] = NULL; 2000 2001 /* Copy the token in, removing escapes */ 2002 for (j = 0; s[i] != '\0'; i++) { 2003 if (s[i] == '\\') { 2004 if (s[i + 1] == '\'' || 2005 s[i + 1] == '\"' || 2006 s[i + 1] == '\\' || 2007 (quote == 0 && s[i + 1] == ' ')) { 2008 i++; /* Skip '\' */ 2009 arg[j++] = s[i]; 2010 } else { 2011 /* Unrecognised escape */ 2012 arg[j++] = s[i]; 2013 } 2014 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 2015 break; /* done */ 2016 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 2017 quote = s[i]; /* quote start */ 2018 else if (quote != 0 && s[i] == quote) 2019 quote = 0; /* quote end */ 2020 else 2021 arg[j++] = s[i]; 2022 } 2023 if (s[i] == '\0') { 2024 if (quote != 0) { 2025 /* Ran out of string looking for close quote */ 2026 r = SSH_ERR_INVALID_FORMAT; 2027 goto out; 2028 } 2029 break; 2030 } 2031 } 2032 /* Success */ 2033 *argcp = argc; 2034 *argvp = argv; 2035 argc = 0; 2036 argv = NULL; 2037 r = 0; 2038 out: 2039 if (argc != 0 && argv != NULL) { 2040 for (i = 0; i < argc; i++) 2041 free(argv[i]); 2042 free(argv); 2043 } 2044 return r; 2045 } 2046 2047 /* 2048 * Reassemble an argument vector into a string, quoting and escaping as 2049 * necessary. Caller must free returned string. 2050 */ 2051 char * 2052 argv_assemble(int argc, char **argv) 2053 { 2054 int i, j, ws, r; 2055 char c, *ret; 2056 struct sshbuf *buf, *arg; 2057 2058 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2059 fatal_f("sshbuf_new failed"); 2060 2061 for (i = 0; i < argc; i++) { 2062 ws = 0; 2063 sshbuf_reset(arg); 2064 for (j = 0; argv[i][j] != '\0'; j++) { 2065 r = 0; 2066 c = argv[i][j]; 2067 switch (c) { 2068 case ' ': 2069 case '\t': 2070 ws = 1; 2071 r = sshbuf_put_u8(arg, c); 2072 break; 2073 case '\\': 2074 case '\'': 2075 case '"': 2076 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2077 break; 2078 /* FALLTHROUGH */ 2079 default: 2080 r = sshbuf_put_u8(arg, c); 2081 break; 2082 } 2083 if (r != 0) 2084 fatal_fr(r, "sshbuf_put_u8"); 2085 } 2086 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2087 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2088 (r = sshbuf_putb(buf, arg)) != 0 || 2089 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2090 fatal_fr(r, "assemble"); 2091 } 2092 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2093 fatal_f("malloc failed"); 2094 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2095 ret[sshbuf_len(buf)] = '\0'; 2096 sshbuf_free(buf); 2097 sshbuf_free(arg); 2098 return ret; 2099 } 2100 2101 char * 2102 argv_next(int *argcp, char ***argvp) 2103 { 2104 char *ret = (*argvp)[0]; 2105 2106 if (*argcp > 0 && ret != NULL) { 2107 (*argcp)--; 2108 (*argvp)++; 2109 } 2110 return ret; 2111 } 2112 2113 void 2114 argv_consume(int *argcp) 2115 { 2116 *argcp = 0; 2117 } 2118 2119 void 2120 argv_free(char **av, int ac) 2121 { 2122 int i; 2123 2124 if (av == NULL) 2125 return; 2126 for (i = 0; i < ac; i++) 2127 free(av[i]); 2128 free(av); 2129 } 2130 2131 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2132 int 2133 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2134 { 2135 int status; 2136 2137 while (waitpid(pid, &status, 0) == -1) { 2138 if (errno != EINTR) { 2139 error("%s waitpid: %s", tag, strerror(errno)); 2140 return -1; 2141 } 2142 } 2143 if (WIFSIGNALED(status)) { 2144 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2145 return -1; 2146 } else if (WEXITSTATUS(status) != 0) { 2147 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2148 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2149 return -1; 2150 } 2151 return 0; 2152 } 2153 2154 /* 2155 * Check a given path for security. This is defined as all components 2156 * of the path to the file must be owned by either the owner of 2157 * of the file or root and no directories must be group or world writable. 2158 * 2159 * XXX Should any specific check be done for sym links ? 2160 * 2161 * Takes a file name, its stat information (preferably from fstat() to 2162 * avoid races), the uid of the expected owner, their home directory and an 2163 * error buffer plus max size as arguments. 2164 * 2165 * Returns 0 on success and -1 on failure 2166 */ 2167 int 2168 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2169 uid_t uid, char *err, size_t errlen) 2170 { 2171 char buf[PATH_MAX], homedir[PATH_MAX]; 2172 char *cp; 2173 int comparehome = 0; 2174 struct stat st; 2175 2176 if (realpath(name, buf) == NULL) { 2177 snprintf(err, errlen, "realpath %s failed: %s", name, 2178 strerror(errno)); 2179 return -1; 2180 } 2181 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2182 comparehome = 1; 2183 2184 if (!S_ISREG(stp->st_mode)) { 2185 snprintf(err, errlen, "%s is not a regular file", buf); 2186 return -1; 2187 } 2188 if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || 2189 (stp->st_mode & 022) != 0) { 2190 snprintf(err, errlen, "bad ownership or modes for file %s", 2191 buf); 2192 return -1; 2193 } 2194 2195 /* for each component of the canonical path, walking upwards */ 2196 for (;;) { 2197 if ((cp = dirname(buf)) == NULL) { 2198 snprintf(err, errlen, "dirname() failed"); 2199 return -1; 2200 } 2201 strlcpy(buf, cp, sizeof(buf)); 2202 2203 if (stat(buf, &st) == -1 || 2204 (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || 2205 (st.st_mode & 022) != 0) { 2206 snprintf(err, errlen, 2207 "bad ownership or modes for directory %s", buf); 2208 return -1; 2209 } 2210 2211 /* If are past the homedir then we can stop */ 2212 if (comparehome && strcmp(homedir, buf) == 0) 2213 break; 2214 2215 /* 2216 * dirname should always complete with a "/" path, 2217 * but we can be paranoid and check for "." too 2218 */ 2219 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2220 break; 2221 } 2222 return 0; 2223 } 2224 2225 /* 2226 * Version of safe_path() that accepts an open file descriptor to 2227 * avoid races. 2228 * 2229 * Returns 0 on success and -1 on failure 2230 */ 2231 int 2232 safe_path_fd(int fd, const char *file, struct passwd *pw, 2233 char *err, size_t errlen) 2234 { 2235 struct stat st; 2236 2237 /* check the open file to avoid races */ 2238 if (fstat(fd, &st) == -1) { 2239 snprintf(err, errlen, "cannot stat file %s: %s", 2240 file, strerror(errno)); 2241 return -1; 2242 } 2243 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2244 } 2245 2246 /* 2247 * Sets the value of the given variable in the environment. If the variable 2248 * already exists, its value is overridden. 2249 */ 2250 void 2251 child_set_env(char ***envp, u_int *envsizep, const char *name, 2252 const char *value) 2253 { 2254 char **env; 2255 u_int envsize; 2256 u_int i, namelen; 2257 2258 if (strchr(name, '=') != NULL) { 2259 error("Invalid environment variable \"%.100s\"", name); 2260 return; 2261 } 2262 2263 /* 2264 * If we're passed an uninitialized list, allocate a single null 2265 * entry before continuing. 2266 */ 2267 if (*envp == NULL && *envsizep == 0) { 2268 *envp = xmalloc(sizeof(char *)); 2269 *envp[0] = NULL; 2270 *envsizep = 1; 2271 } 2272 2273 /* 2274 * Find the slot where the value should be stored. If the variable 2275 * already exists, we reuse the slot; otherwise we append a new slot 2276 * at the end of the array, expanding if necessary. 2277 */ 2278 env = *envp; 2279 namelen = strlen(name); 2280 for (i = 0; env[i]; i++) 2281 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2282 break; 2283 if (env[i]) { 2284 /* Reuse the slot. */ 2285 free(env[i]); 2286 } else { 2287 /* New variable. Expand if necessary. */ 2288 envsize = *envsizep; 2289 if (i >= envsize - 1) { 2290 if (envsize >= 1000) 2291 fatal("child_set_env: too many env vars"); 2292 envsize += 50; 2293 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2294 *envsizep = envsize; 2295 } 2296 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2297 env[i + 1] = NULL; 2298 } 2299 2300 /* Allocate space and format the variable in the appropriate slot. */ 2301 /* XXX xasprintf */ 2302 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2303 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2304 } 2305 2306 /* 2307 * Check and optionally lowercase a domain name, also removes trailing '.' 2308 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2309 */ 2310 int 2311 valid_domain(char *name, int makelower, const char **errstr) 2312 { 2313 size_t i, l = strlen(name); 2314 u_char c, last = '\0'; 2315 static char errbuf[256]; 2316 2317 if (l == 0) { 2318 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2319 goto bad; 2320 } 2321 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2322 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2323 "starts with invalid character", name); 2324 goto bad; 2325 } 2326 for (i = 0; i < l; i++) { 2327 c = tolower((u_char)name[i]); 2328 if (makelower) 2329 name[i] = (char)c; 2330 if (last == '.' && c == '.') { 2331 snprintf(errbuf, sizeof(errbuf), "domain name " 2332 "\"%.100s\" contains consecutive separators", name); 2333 goto bad; 2334 } 2335 if (c != '.' && c != '-' && !isalnum(c) && 2336 c != '_') /* technically invalid, but common */ { 2337 snprintf(errbuf, sizeof(errbuf), "domain name " 2338 "\"%.100s\" contains invalid characters", name); 2339 goto bad; 2340 } 2341 last = c; 2342 } 2343 if (name[l - 1] == '.') 2344 name[l - 1] = '\0'; 2345 if (errstr != NULL) 2346 *errstr = NULL; 2347 return 1; 2348 bad: 2349 if (errstr != NULL) 2350 *errstr = errbuf; 2351 return 0; 2352 } 2353 2354 /* 2355 * Verify that a environment variable name (not including initial '$') is 2356 * valid; consisting of one or more alphanumeric or underscore characters only. 2357 * Returns 1 on valid, 0 otherwise. 2358 */ 2359 int 2360 valid_env_name(const char *name) 2361 { 2362 const char *cp; 2363 2364 if (name[0] == '\0') 2365 return 0; 2366 for (cp = name; *cp != '\0'; cp++) { 2367 if (!isalnum((u_char)*cp) && *cp != '_') 2368 return 0; 2369 } 2370 return 1; 2371 } 2372 2373 const char * 2374 atoi_err(const char *nptr, int *val) 2375 { 2376 const char *errstr = NULL; 2377 long long num; 2378 2379 if (nptr == NULL || *nptr == '\0') 2380 return "missing"; 2381 num = strtonum(nptr, 0, INT_MAX, &errstr); 2382 if (errstr == NULL) 2383 *val = (int)num; 2384 return errstr; 2385 } 2386 2387 int 2388 parse_absolute_time(const char *s, uint64_t *tp) 2389 { 2390 struct tm tm; 2391 time_t tt; 2392 char buf[32], *fmt; 2393 2394 *tp = 0; 2395 2396 /* 2397 * POSIX strptime says "The application shall ensure that there 2398 * is white-space or other non-alphanumeric characters between 2399 * any two conversion specifications" so arrange things this way. 2400 */ 2401 switch (strlen(s)) { 2402 case 8: /* YYYYMMDD */ 2403 fmt = "%Y-%m-%d"; 2404 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2405 break; 2406 case 12: /* YYYYMMDDHHMM */ 2407 fmt = "%Y-%m-%dT%H:%M"; 2408 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2409 s, s + 4, s + 6, s + 8, s + 10); 2410 break; 2411 case 14: /* YYYYMMDDHHMMSS */ 2412 fmt = "%Y-%m-%dT%H:%M:%S"; 2413 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2414 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2415 break; 2416 default: 2417 return SSH_ERR_INVALID_FORMAT; 2418 } 2419 2420 memset(&tm, 0, sizeof(tm)); 2421 if (strptime(buf, fmt, &tm) == NULL) 2422 return SSH_ERR_INVALID_FORMAT; 2423 if ((tt = mktime(&tm)) < 0) 2424 return SSH_ERR_INVALID_FORMAT; 2425 /* success */ 2426 *tp = (uint64_t)tt; 2427 return 0; 2428 } 2429 2430 /* On OpenBSD time_t is int64_t which is long long. */ 2431 /* #define SSH_TIME_T_MAX LLONG_MAX */ 2432 2433 void 2434 format_absolute_time(uint64_t t, char *buf, size_t len) 2435 { 2436 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2437 struct tm tm; 2438 2439 localtime_r(&tt, &tm); 2440 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2441 } 2442 2443 /* check if path is absolute */ 2444 int 2445 path_absolute(const char *path) 2446 { 2447 return (*path == '/') ? 1 : 0; 2448 } 2449 2450 void 2451 skip_space(char **cpp) 2452 { 2453 char *cp; 2454 2455 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2456 ; 2457 *cpp = cp; 2458 } 2459 2460 /* authorized_key-style options parsing helpers */ 2461 2462 /* 2463 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2464 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2465 * if negated option matches. 2466 * If the option or negated option matches, then *optsp is updated to 2467 * point to the first character after the option. 2468 */ 2469 int 2470 opt_flag(const char *opt, int allow_negate, const char **optsp) 2471 { 2472 size_t opt_len = strlen(opt); 2473 const char *opts = *optsp; 2474 int negate = 0; 2475 2476 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2477 opts += 3; 2478 negate = 1; 2479 } 2480 if (strncasecmp(opts, opt, opt_len) == 0) { 2481 *optsp = opts + opt_len; 2482 return negate ? 0 : 1; 2483 } 2484 return -1; 2485 } 2486 2487 char * 2488 opt_dequote(const char **sp, const char **errstrp) 2489 { 2490 const char *s = *sp; 2491 char *ret; 2492 size_t i; 2493 2494 *errstrp = NULL; 2495 if (*s != '"') { 2496 *errstrp = "missing start quote"; 2497 return NULL; 2498 } 2499 s++; 2500 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2501 *errstrp = "memory allocation failed"; 2502 return NULL; 2503 } 2504 for (i = 0; *s != '\0' && *s != '"';) { 2505 if (s[0] == '\\' && s[1] == '"') 2506 s++; 2507 ret[i++] = *s++; 2508 } 2509 if (*s == '\0') { 2510 *errstrp = "missing end quote"; 2511 free(ret); 2512 return NULL; 2513 } 2514 ret[i] = '\0'; 2515 s++; 2516 *sp = s; 2517 return ret; 2518 } 2519 2520 int 2521 opt_match(const char **opts, const char *term) 2522 { 2523 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2524 (*opts)[strlen(term)] == '=') { 2525 *opts += strlen(term) + 1; 2526 return 1; 2527 } 2528 return 0; 2529 } 2530 2531 void 2532 opt_array_append2(const char *file, const int line, const char *directive, 2533 char ***array, int **iarray, u_int *lp, const char *s, int i) 2534 { 2535 2536 if (*lp >= INT_MAX) 2537 fatal("%s line %d: Too many %s entries", file, line, directive); 2538 2539 if (iarray != NULL) { 2540 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2541 sizeof(**iarray)); 2542 (*iarray)[*lp] = i; 2543 } 2544 2545 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2546 (*array)[*lp] = xstrdup(s); 2547 (*lp)++; 2548 } 2549 2550 void 2551 opt_array_append(const char *file, const int line, const char *directive, 2552 char ***array, u_int *lp, const char *s) 2553 { 2554 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2555 } 2556 2557 sshsig_t 2558 ssh_signal(int signum, sshsig_t handler) 2559 { 2560 struct sigaction sa, osa; 2561 2562 /* mask all other signals while in handler */ 2563 memset(&sa, 0, sizeof(sa)); 2564 sa.sa_handler = handler; 2565 sigfillset(&sa.sa_mask); 2566 #if defined(SA_RESTART) && !defined(NO_SA_RESTART) 2567 if (signum != SIGALRM) 2568 sa.sa_flags = SA_RESTART; 2569 #endif 2570 if (sigaction(signum, &sa, &osa) == -1) { 2571 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2572 return SIG_ERR; 2573 } 2574 return osa.sa_handler; 2575 } 2576 2577 int 2578 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2579 { 2580 int devnull, ret = 0; 2581 2582 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2583 error_f("open %s: %s", _PATH_DEVNULL, 2584 strerror(errno)); 2585 return -1; 2586 } 2587 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2588 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2589 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2590 error_f("dup2: %s", strerror(errno)); 2591 ret = -1; 2592 } 2593 if (devnull > STDERR_FILENO) 2594 close(devnull); 2595 return ret; 2596 } 2597 2598 /* 2599 * Runs command in a subprocess with a minimal environment. 2600 * Returns pid on success, 0 on failure. 2601 * The child stdout and stderr maybe captured, left attached or sent to 2602 * /dev/null depending on the contents of flags. 2603 * "tag" is prepended to log messages. 2604 * NB. "command" is only used for logging; the actual command executed is 2605 * av[0]. 2606 */ 2607 pid_t 2608 subprocess(const char *tag, const char *command, 2609 int ac, char **av, FILE **child, u_int flags, 2610 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2611 { 2612 FILE *f = NULL; 2613 struct stat st; 2614 int fd, devnull, p[2], i; 2615 pid_t pid; 2616 char *cp, errmsg[512]; 2617 u_int nenv = 0; 2618 char **env = NULL; 2619 2620 /* If dropping privs, then must specify user and restore function */ 2621 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2622 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2623 return 0; 2624 } 2625 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2626 error("%s: no user for current uid", tag); 2627 return 0; 2628 } 2629 if (child != NULL) 2630 *child = NULL; 2631 2632 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2633 tag, command, pw->pw_name, flags); 2634 2635 /* Check consistency */ 2636 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2637 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2638 error_f("inconsistent flags"); 2639 return 0; 2640 } 2641 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2642 error_f("inconsistent flags/output"); 2643 return 0; 2644 } 2645 2646 /* 2647 * If executing an explicit binary, then verify the it exists 2648 * and appears safe-ish to execute 2649 */ 2650 if (!path_absolute(av[0])) { 2651 error("%s path is not absolute", tag); 2652 return 0; 2653 } 2654 if (drop_privs != NULL) 2655 drop_privs(pw); 2656 if (stat(av[0], &st) == -1) { 2657 error("Could not stat %s \"%s\": %s", tag, 2658 av[0], strerror(errno)); 2659 goto restore_return; 2660 } 2661 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2662 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2663 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2664 goto restore_return; 2665 } 2666 /* Prepare to keep the child's stdout if requested */ 2667 if (pipe(p) == -1) { 2668 error("%s: pipe: %s", tag, strerror(errno)); 2669 restore_return: 2670 if (restore_privs != NULL) 2671 restore_privs(); 2672 return 0; 2673 } 2674 if (restore_privs != NULL) 2675 restore_privs(); 2676 2677 switch ((pid = fork())) { 2678 case -1: /* error */ 2679 error("%s: fork: %s", tag, strerror(errno)); 2680 close(p[0]); 2681 close(p[1]); 2682 return 0; 2683 case 0: /* child */ 2684 /* Prepare a minimal environment for the child. */ 2685 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2686 nenv = 5; 2687 env = xcalloc(sizeof(*env), nenv); 2688 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2689 child_set_env(&env, &nenv, "USER", pw->pw_name); 2690 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2691 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2692 if ((cp = getenv("LANG")) != NULL) 2693 child_set_env(&env, &nenv, "LANG", cp); 2694 } 2695 2696 for (i = 1; i < NSIG; i++) 2697 ssh_signal(i, SIG_DFL); 2698 2699 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2700 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2701 strerror(errno)); 2702 _exit(1); 2703 } 2704 if (dup2(devnull, STDIN_FILENO) == -1) { 2705 error("%s: dup2: %s", tag, strerror(errno)); 2706 _exit(1); 2707 } 2708 2709 /* Set up stdout as requested; leave stderr in place for now. */ 2710 fd = -1; 2711 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2712 fd = p[1]; 2713 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2714 fd = devnull; 2715 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2716 error("%s: dup2: %s", tag, strerror(errno)); 2717 _exit(1); 2718 } 2719 closefrom(STDERR_FILENO + 1); 2720 2721 if (geteuid() == 0 && 2722 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2723 error("%s: initgroups(%s, %u): %s", tag, 2724 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2725 _exit(1); 2726 } 2727 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2728 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2729 strerror(errno)); 2730 _exit(1); 2731 } 2732 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2733 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2734 strerror(errno)); 2735 _exit(1); 2736 } 2737 /* stdin is pointed to /dev/null at this point */ 2738 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2739 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2740 error("%s: dup2: %s", tag, strerror(errno)); 2741 _exit(1); 2742 } 2743 if (env != NULL) 2744 execve(av[0], av, env); 2745 else 2746 execv(av[0], av); 2747 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2748 command, strerror(errno)); 2749 _exit(127); 2750 default: /* parent */ 2751 break; 2752 } 2753 2754 close(p[1]); 2755 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2756 close(p[0]); 2757 else if ((f = fdopen(p[0], "r")) == NULL) { 2758 error("%s: fdopen: %s", tag, strerror(errno)); 2759 close(p[0]); 2760 /* Don't leave zombie child */ 2761 kill(pid, SIGTERM); 2762 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2763 ; 2764 return 0; 2765 } 2766 /* Success */ 2767 debug3_f("%s pid %ld", tag, (long)pid); 2768 if (child != NULL) 2769 *child = f; 2770 return pid; 2771 } 2772 2773 const char * 2774 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2775 { 2776 size_t i, envlen; 2777 2778 envlen = strlen(env); 2779 for (i = 0; i < nenvs; i++) { 2780 if (strncmp(envs[i], env, envlen) == 0 && 2781 envs[i][envlen] == '=') { 2782 return envs[i] + envlen + 1; 2783 } 2784 } 2785 return NULL; 2786 } 2787