1 /* $NetBSD: misc.c,v 1.28 2021/09/27 17:03:13 christos Exp $ */ 2 /* $OpenBSD: misc.c,v 1.170 2021/09/26 14:01:03 djm Exp $ */ 3 4 /* 5 * Copyright (c) 2000 Markus Friedl. All rights reserved. 6 * Copyright (c) 2005-2020 Damien Miller. All rights reserved. 7 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org> 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 20 */ 21 22 #include "includes.h" 23 __RCSID("$NetBSD: misc.c,v 1.28 2021/09/27 17:03:13 christos Exp $"); 24 25 #include <sys/types.h> 26 #include <sys/ioctl.h> 27 #include <sys/socket.h> 28 #include <sys/stat.h> 29 #include <sys/time.h> 30 #include <sys/wait.h> 31 #include <sys/un.h> 32 33 #include <net/if.h> 34 #include <net/if_tun.h> 35 #include <netinet/in.h> 36 #include <netinet/ip.h> 37 #include <netinet/tcp.h> 38 #include <arpa/inet.h> 39 40 #include <ctype.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <netdb.h> 44 #include <paths.h> 45 #include <pwd.h> 46 #include <libgen.h> 47 #include <limits.h> 48 #include <poll.h> 49 #include <signal.h> 50 #include <stdarg.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #include "xmalloc.h" 57 #include "misc.h" 58 #include "log.h" 59 #include "ssh.h" 60 #include "sshbuf.h" 61 #include "ssherr.h" 62 63 /* remove newline at end of string */ 64 char * 65 chop(char *s) 66 { 67 char *t = s; 68 while (*t) { 69 if (*t == '\n' || *t == '\r') { 70 *t = '\0'; 71 return s; 72 } 73 t++; 74 } 75 return s; 76 77 } 78 79 /* remove whitespace from end of string */ 80 void 81 rtrim(char *s) 82 { 83 size_t i; 84 85 if ((i = strlen(s)) == 0) 86 return; 87 for (i--; i > 0; i--) { 88 if (isspace((int)s[i])) 89 s[i] = '\0'; 90 } 91 } 92 93 /* set/unset filedescriptor to non-blocking */ 94 int 95 set_nonblock(int fd) 96 { 97 int val; 98 99 val = fcntl(fd, F_GETFL); 100 if (val == -1) { 101 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 102 return (-1); 103 } 104 if (val & O_NONBLOCK) { 105 debug3("fd %d is O_NONBLOCK", fd); 106 return (0); 107 } 108 debug2("fd %d setting O_NONBLOCK", fd); 109 val |= O_NONBLOCK; 110 if (fcntl(fd, F_SETFL, val) == -1) { 111 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 112 strerror(errno)); 113 return (-1); 114 } 115 return (0); 116 } 117 118 int 119 unset_nonblock(int fd) 120 { 121 int val; 122 123 val = fcntl(fd, F_GETFL); 124 if (val == -1) { 125 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 126 return (-1); 127 } 128 if (!(val & O_NONBLOCK)) { 129 debug3("fd %d is not O_NONBLOCK", fd); 130 return (0); 131 } 132 debug("fd %d clearing O_NONBLOCK", fd); 133 val &= ~O_NONBLOCK; 134 if (fcntl(fd, F_SETFL, val) == -1) { 135 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 136 fd, strerror(errno)); 137 return (-1); 138 } 139 return (0); 140 } 141 142 const char * 143 ssh_gai_strerror(int gaierr) 144 { 145 if (gaierr == EAI_SYSTEM && errno != 0) 146 return strerror(errno); 147 return gai_strerror(gaierr); 148 } 149 150 /* disable nagle on socket */ 151 void 152 set_nodelay(int fd) 153 { 154 int opt; 155 socklen_t optlen; 156 157 optlen = sizeof opt; 158 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 159 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 160 return; 161 } 162 if (opt == 1) { 163 debug2("fd %d is TCP_NODELAY", fd); 164 return; 165 } 166 opt = 1; 167 debug2("fd %d setting TCP_NODELAY", fd); 168 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 169 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 170 } 171 172 /* Allow local port reuse in TIME_WAIT */ 173 int 174 set_reuseaddr(int fd) 175 { 176 int on = 1; 177 178 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 179 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 180 return -1; 181 } 182 return 0; 183 } 184 185 /* Get/set routing domain */ 186 char * 187 get_rdomain(int fd) 188 { 189 #ifdef SO_RTABLE 190 int rtable; 191 char *ret; 192 socklen_t len = sizeof(rtable); 193 194 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 195 error("Failed to get routing domain for fd %d: %s", 196 fd, strerror(errno)); 197 return NULL; 198 } 199 xasprintf(&ret, "%d", rtable); 200 return ret; 201 #else 202 return NULL; 203 #endif 204 } 205 206 int 207 set_rdomain(int fd, const char *name) 208 { 209 #ifdef SO_RTABLE 210 int rtable; 211 const char *errstr; 212 213 if (name == NULL) 214 return 0; /* default table */ 215 216 rtable = (int)strtonum(name, 0, 255, &errstr); 217 if (errstr != NULL) { 218 /* Shouldn't happen */ 219 error("Invalid routing domain \"%s\": %s", name, errstr); 220 return -1; 221 } 222 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 223 &rtable, sizeof(rtable)) == -1) { 224 error("Failed to set routing domain %d on fd %d: %s", 225 rtable, fd, strerror(errno)); 226 return -1; 227 } 228 return 0; 229 #else 230 return -1; 231 #endif 232 } 233 234 int 235 get_sock_af(int fd) 236 { 237 struct sockaddr_storage to; 238 socklen_t tolen = sizeof(to); 239 240 memset(&to, 0, sizeof(to)); 241 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 242 return -1; 243 return to.ss_family; 244 } 245 246 void 247 set_sock_tos(int fd, int tos) 248 { 249 int af; 250 251 switch ((af = get_sock_af(fd))) { 252 case -1: 253 /* assume not a socket */ 254 break; 255 case AF_INET: 256 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 257 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 258 &tos, sizeof(tos)) == -1) { 259 error("setsockopt socket %d IP_TOS %d: %s:", 260 fd, tos, strerror(errno)); 261 } 262 break; 263 case AF_INET6: 264 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 265 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 266 &tos, sizeof(tos)) == -1) { 267 error("setsockopt socket %d IPV6_TCLASS %d: %.100s:", 268 fd, tos, strerror(errno)); 269 } 270 break; 271 default: 272 debug2_f("unsupported socket family %d", af); 273 break; 274 } 275 } 276 277 /* 278 * Wait up to *timeoutp milliseconds for events on fd. Updates 279 * *timeoutp with time remaining. 280 * Returns 0 if fd ready or -1 on timeout or error (see errno). 281 */ 282 static int 283 waitfd(int fd, int *timeoutp, short events) 284 { 285 struct pollfd pfd; 286 struct timeval t_start; 287 int oerrno, r; 288 289 pfd.fd = fd; 290 pfd.events = events; 291 for (; *timeoutp >= 0;) { 292 monotime_tv(&t_start); 293 r = poll(&pfd, 1, *timeoutp); 294 oerrno = errno; 295 ms_subtract_diff(&t_start, timeoutp); 296 errno = oerrno; 297 if (r > 0) 298 return 0; 299 else if (r == -1 && errno != EAGAIN && errno != EINTR) 300 return -1; 301 else if (r == 0) 302 break; 303 } 304 /* timeout */ 305 errno = ETIMEDOUT; 306 return -1; 307 } 308 309 /* 310 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 311 * *timeoutp with time remaining. 312 * Returns 0 if fd ready or -1 on timeout or error (see errno). 313 */ 314 int 315 waitrfd(int fd, int *timeoutp) { 316 return waitfd(fd, timeoutp, POLLIN); 317 } 318 319 /* 320 * Attempt a non-blocking connect(2) to the specified address, waiting up to 321 * *timeoutp milliseconds for the connection to complete. If the timeout is 322 * <=0, then wait indefinitely. 323 * 324 * Returns 0 on success or -1 on failure. 325 */ 326 int 327 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 328 socklen_t addrlen, int *timeoutp) 329 { 330 int optval = 0; 331 socklen_t optlen = sizeof(optval); 332 333 /* No timeout: just do a blocking connect() */ 334 if (timeoutp == NULL || *timeoutp <= 0) 335 return connect(sockfd, serv_addr, addrlen); 336 337 set_nonblock(sockfd); 338 for (;;) { 339 if (connect(sockfd, serv_addr, addrlen) == 0) { 340 /* Succeeded already? */ 341 unset_nonblock(sockfd); 342 return 0; 343 } else if (errno == EINTR) 344 continue; 345 else if (errno != EINPROGRESS) 346 return -1; 347 break; 348 } 349 350 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) 351 return -1; 352 353 /* Completed or failed */ 354 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 355 debug("getsockopt: %s", strerror(errno)); 356 return -1; 357 } 358 if (optval != 0) { 359 errno = optval; 360 return -1; 361 } 362 unset_nonblock(sockfd); 363 return 0; 364 } 365 366 /* Characters considered whitespace in strsep calls. */ 367 #define WHITESPACE " \t\r\n" 368 #define QUOTE "\"" 369 370 /* return next token in configuration line */ 371 static char * 372 strdelim_internal(char **s, int split_equals) 373 { 374 char *old; 375 int wspace = 0; 376 377 if (*s == NULL) 378 return NULL; 379 380 old = *s; 381 382 *s = strpbrk(*s, 383 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 384 if (*s == NULL) 385 return (old); 386 387 if (*s[0] == '\"') { 388 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 389 /* Find matching quote */ 390 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 391 return (NULL); /* no matching quote */ 392 } else { 393 *s[0] = '\0'; 394 *s += strspn(*s + 1, WHITESPACE) + 1; 395 return (old); 396 } 397 } 398 399 /* Allow only one '=' to be skipped */ 400 if (split_equals && *s[0] == '=') 401 wspace = 1; 402 *s[0] = '\0'; 403 404 /* Skip any extra whitespace after first token */ 405 *s += strspn(*s + 1, WHITESPACE) + 1; 406 if (split_equals && *s[0] == '=' && !wspace) 407 *s += strspn(*s + 1, WHITESPACE) + 1; 408 409 return (old); 410 } 411 412 /* 413 * Return next token in configuration line; splts on whitespace or a 414 * single '=' character. 415 */ 416 char * 417 strdelim(char **s) 418 { 419 return strdelim_internal(s, 1); 420 } 421 422 /* 423 * Return next token in configuration line; splts on whitespace only. 424 */ 425 char * 426 strdelimw(char **s) 427 { 428 return strdelim_internal(s, 0); 429 } 430 431 struct passwd * 432 pwcopy(struct passwd *pw) 433 { 434 struct passwd *copy = xcalloc(1, sizeof(*copy)); 435 436 copy->pw_name = xstrdup(pw->pw_name); 437 copy->pw_passwd = xstrdup(pw->pw_passwd); 438 copy->pw_gecos = xstrdup(pw->pw_gecos); 439 copy->pw_uid = pw->pw_uid; 440 copy->pw_gid = pw->pw_gid; 441 copy->pw_expire = pw->pw_expire; 442 copy->pw_change = pw->pw_change; 443 copy->pw_class = xstrdup(pw->pw_class); 444 copy->pw_dir = xstrdup(pw->pw_dir); 445 copy->pw_shell = xstrdup(pw->pw_shell); 446 return copy; 447 } 448 449 /* 450 * Convert ASCII string to TCP/IP port number. 451 * Port must be >=0 and <=65535. 452 * Return -1 if invalid. 453 */ 454 int 455 a2port(const char *s) 456 { 457 struct servent *se; 458 long long port; 459 const char *errstr; 460 461 port = strtonum(s, 0, 65535, &errstr); 462 if (errstr == NULL) 463 return (int)port; 464 if ((se = getservbyname(s, "tcp")) != NULL) 465 return ntohs(se->s_port); 466 return -1; 467 } 468 469 int 470 a2tun(const char *s, int *remote) 471 { 472 const char *errstr = NULL; 473 char *sp, *ep; 474 int tun; 475 476 if (remote != NULL) { 477 *remote = SSH_TUNID_ANY; 478 sp = xstrdup(s); 479 if ((ep = strchr(sp, ':')) == NULL) { 480 free(sp); 481 return (a2tun(s, NULL)); 482 } 483 ep[0] = '\0'; ep++; 484 *remote = a2tun(ep, NULL); 485 tun = a2tun(sp, NULL); 486 free(sp); 487 return (*remote == SSH_TUNID_ERR ? *remote : tun); 488 } 489 490 if (strcasecmp(s, "any") == 0) 491 return (SSH_TUNID_ANY); 492 493 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 494 if (errstr != NULL) 495 return (SSH_TUNID_ERR); 496 497 return (tun); 498 } 499 500 #define SECONDS 1 501 #define MINUTES (SECONDS * 60) 502 #define HOURS (MINUTES * 60) 503 #define DAYS (HOURS * 24) 504 #define WEEKS (DAYS * 7) 505 506 /* 507 * Convert a time string into seconds; format is 508 * a sequence of: 509 * time[qualifier] 510 * 511 * Valid time qualifiers are: 512 * <none> seconds 513 * s|S seconds 514 * m|M minutes 515 * h|H hours 516 * d|D days 517 * w|W weeks 518 * 519 * Examples: 520 * 90m 90 minutes 521 * 1h30m 90 minutes 522 * 2d 2 days 523 * 1w 1 week 524 * 525 * Return -1 if time string is invalid. 526 */ 527 int 528 convtime(const char *s) 529 { 530 long total, secs, multiplier; 531 const char *p; 532 char *endp; 533 534 errno = 0; 535 total = 0; 536 p = s; 537 538 if (p == NULL || *p == '\0') 539 return -1; 540 541 while (*p) { 542 secs = strtol(p, &endp, 10); 543 if (p == endp || 544 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 545 secs < 0) 546 return -1; 547 548 multiplier = 1; 549 switch (*endp++) { 550 case '\0': 551 endp--; 552 break; 553 case 's': 554 case 'S': 555 break; 556 case 'm': 557 case 'M': 558 multiplier = MINUTES; 559 break; 560 case 'h': 561 case 'H': 562 multiplier = HOURS; 563 break; 564 case 'd': 565 case 'D': 566 multiplier = DAYS; 567 break; 568 case 'w': 569 case 'W': 570 multiplier = WEEKS; 571 break; 572 default: 573 return -1; 574 } 575 if (secs > INT_MAX / multiplier) 576 return -1; 577 secs *= multiplier; 578 if (total > INT_MAX - secs) 579 return -1; 580 total += secs; 581 if (total < 0) 582 return -1; 583 p = endp; 584 } 585 586 return total; 587 } 588 589 #define TF_BUFS 8 590 #define TF_LEN 21 591 592 const char * 593 fmt_timeframe(time_t t) 594 { 595 char *buf; 596 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 597 static int idx = 0; 598 unsigned int sec, min, hrs, day; 599 unsigned long long week; 600 601 buf = tfbuf[idx++]; 602 if (idx == TF_BUFS) 603 idx = 0; 604 605 week = t; 606 607 sec = week % 60; 608 week /= 60; 609 min = week % 60; 610 week /= 60; 611 hrs = week % 24; 612 week /= 24; 613 day = week % 7; 614 week /= 7; 615 616 if (week > 0) 617 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 618 else if (day > 0) 619 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 620 else 621 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 622 623 return (buf); 624 } 625 626 /* 627 * Returns a standardized host+port identifier string. 628 * Caller must free returned string. 629 */ 630 char * 631 put_host_port(const char *host, u_short port) 632 { 633 char *hoststr; 634 635 if (port == 0 || port == SSH_DEFAULT_PORT) 636 return(xstrdup(host)); 637 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 638 fatal("put_host_port: asprintf: %s", strerror(errno)); 639 debug3("put_host_port: %s", hoststr); 640 return hoststr; 641 } 642 643 /* 644 * Search for next delimiter between hostnames/addresses and ports. 645 * Argument may be modified (for termination). 646 * Returns *cp if parsing succeeds. 647 * *cp is set to the start of the next field, if one was found. 648 * The delimiter char, if present, is stored in delim. 649 * If this is the last field, *cp is set to NULL. 650 */ 651 char * 652 hpdelim2(char **cp, char *delim) 653 { 654 char *s, *old; 655 656 if (cp == NULL || *cp == NULL) 657 return NULL; 658 659 old = s = *cp; 660 if (*s == '[') { 661 if ((s = strchr(s, ']')) == NULL) 662 return NULL; 663 else 664 s++; 665 } else if ((s = strpbrk(s, ":/")) == NULL) 666 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 667 668 switch (*s) { 669 case '\0': 670 *cp = NULL; /* no more fields*/ 671 break; 672 673 case ':': 674 case '/': 675 if (delim != NULL) 676 *delim = *s; 677 *s = '\0'; /* terminate */ 678 *cp = s + 1; 679 break; 680 681 default: 682 return NULL; 683 } 684 685 return old; 686 } 687 688 char * 689 hpdelim(char **cp) 690 { 691 return hpdelim2(cp, NULL); 692 } 693 694 char * 695 cleanhostname(char *host) 696 { 697 if (*host == '[' && host[strlen(host) - 1] == ']') { 698 host[strlen(host) - 1] = '\0'; 699 return (host + 1); 700 } else 701 return host; 702 } 703 704 char * 705 colon(char *cp) 706 { 707 int flag = 0; 708 709 if (*cp == ':') /* Leading colon is part of file name. */ 710 return NULL; 711 if (*cp == '[') 712 flag = 1; 713 714 for (; *cp; ++cp) { 715 if (*cp == '@' && *(cp+1) == '[') 716 flag = 1; 717 if (*cp == ']' && *(cp+1) == ':' && flag) 718 return (cp+1); 719 if (*cp == ':' && !flag) 720 return (cp); 721 if (*cp == '/') 722 return NULL; 723 } 724 return NULL; 725 } 726 727 /* 728 * Parse a [user@]host:[path] string. 729 * Caller must free returned user, host and path. 730 * Any of the pointer return arguments may be NULL (useful for syntax checking). 731 * If user was not specified then *userp will be set to NULL. 732 * If host was not specified then *hostp will be set to NULL. 733 * If path was not specified then *pathp will be set to ".". 734 * Returns 0 on success, -1 on failure. 735 */ 736 int 737 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 738 { 739 char *user = NULL, *host = NULL, *path = NULL; 740 char *tmp, *sdup; 741 int ret = -1; 742 743 if (userp != NULL) 744 *userp = NULL; 745 if (hostp != NULL) 746 *hostp = NULL; 747 if (pathp != NULL) 748 *pathp = NULL; 749 750 sdup = xstrdup(s); 751 752 /* Check for remote syntax: [user@]host:[path] */ 753 if ((tmp = colon(sdup)) == NULL) 754 goto out; 755 756 /* Extract optional path */ 757 *tmp++ = '\0'; 758 if (*tmp == '\0') 759 tmp = __UNCONST("."); 760 path = xstrdup(tmp); 761 762 /* Extract optional user and mandatory host */ 763 tmp = strrchr(sdup, '@'); 764 if (tmp != NULL) { 765 *tmp++ = '\0'; 766 host = xstrdup(cleanhostname(tmp)); 767 if (*sdup != '\0') 768 user = xstrdup(sdup); 769 } else { 770 host = xstrdup(cleanhostname(sdup)); 771 user = NULL; 772 } 773 774 /* Success */ 775 if (userp != NULL) { 776 *userp = user; 777 user = NULL; 778 } 779 if (hostp != NULL) { 780 *hostp = host; 781 host = NULL; 782 } 783 if (pathp != NULL) { 784 *pathp = path; 785 path = NULL; 786 } 787 ret = 0; 788 out: 789 free(sdup); 790 free(user); 791 free(host); 792 free(path); 793 return ret; 794 } 795 796 /* 797 * Parse a [user@]host[:port] string. 798 * Caller must free returned user and host. 799 * Any of the pointer return arguments may be NULL (useful for syntax checking). 800 * If user was not specified then *userp will be set to NULL. 801 * If port was not specified then *portp will be -1. 802 * Returns 0 on success, -1 on failure. 803 */ 804 int 805 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 806 { 807 char *sdup, *cp, *tmp; 808 char *user = NULL, *host = NULL; 809 int port = -1, ret = -1; 810 811 if (userp != NULL) 812 *userp = NULL; 813 if (hostp != NULL) 814 *hostp = NULL; 815 if (portp != NULL) 816 *portp = -1; 817 818 if ((sdup = tmp = strdup(s)) == NULL) 819 return -1; 820 /* Extract optional username */ 821 if ((cp = strrchr(tmp, '@')) != NULL) { 822 *cp = '\0'; 823 if (*tmp == '\0') 824 goto out; 825 if ((user = strdup(tmp)) == NULL) 826 goto out; 827 tmp = cp + 1; 828 } 829 /* Extract mandatory hostname */ 830 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 831 goto out; 832 host = xstrdup(cleanhostname(cp)); 833 /* Convert and verify optional port */ 834 if (tmp != NULL && *tmp != '\0') { 835 if ((port = a2port(tmp)) <= 0) 836 goto out; 837 } 838 /* Success */ 839 if (userp != NULL) { 840 *userp = user; 841 user = NULL; 842 } 843 if (hostp != NULL) { 844 *hostp = host; 845 host = NULL; 846 } 847 if (portp != NULL) 848 *portp = port; 849 ret = 0; 850 out: 851 free(sdup); 852 free(user); 853 free(host); 854 return ret; 855 } 856 857 /* 858 * Converts a two-byte hex string to decimal. 859 * Returns the decimal value or -1 for invalid input. 860 */ 861 static int 862 hexchar(const char *s) 863 { 864 unsigned char result[2]; 865 int i; 866 867 for (i = 0; i < 2; i++) { 868 if (s[i] >= '0' && s[i] <= '9') 869 result[i] = (unsigned char)(s[i] - '0'); 870 else if (s[i] >= 'a' && s[i] <= 'f') 871 result[i] = (unsigned char)(s[i] - 'a') + 10; 872 else if (s[i] >= 'A' && s[i] <= 'F') 873 result[i] = (unsigned char)(s[i] - 'A') + 10; 874 else 875 return -1; 876 } 877 return (result[0] << 4) | result[1]; 878 } 879 880 /* 881 * Decode an url-encoded string. 882 * Returns a newly allocated string on success or NULL on failure. 883 */ 884 static char * 885 urldecode(const char *src) 886 { 887 char *ret, *dst; 888 int ch; 889 890 ret = xmalloc(strlen(src) + 1); 891 for (dst = ret; *src != '\0'; src++) { 892 switch (*src) { 893 case '+': 894 *dst++ = ' '; 895 break; 896 case '%': 897 if (!isxdigit((unsigned char)src[1]) || 898 !isxdigit((unsigned char)src[2]) || 899 (ch = hexchar(src + 1)) == -1) { 900 free(ret); 901 return NULL; 902 } 903 *dst++ = ch; 904 src += 2; 905 break; 906 default: 907 *dst++ = *src; 908 break; 909 } 910 } 911 *dst = '\0'; 912 913 return ret; 914 } 915 916 /* 917 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 918 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 919 * Either user or path may be url-encoded (but not host or port). 920 * Caller must free returned user, host and path. 921 * Any of the pointer return arguments may be NULL (useful for syntax checking) 922 * but the scheme must always be specified. 923 * If user was not specified then *userp will be set to NULL. 924 * If port was not specified then *portp will be -1. 925 * If path was not specified then *pathp will be set to NULL. 926 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 927 */ 928 int 929 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 930 int *portp, char **pathp) 931 { 932 char *uridup, *cp, *tmp, ch; 933 char *user = NULL, *host = NULL, *path = NULL; 934 int port = -1, ret = -1; 935 size_t len; 936 937 len = strlen(scheme); 938 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 939 return 1; 940 uri += len + 3; 941 942 if (userp != NULL) 943 *userp = NULL; 944 if (hostp != NULL) 945 *hostp = NULL; 946 if (portp != NULL) 947 *portp = -1; 948 if (pathp != NULL) 949 *pathp = NULL; 950 951 uridup = tmp = xstrdup(uri); 952 953 /* Extract optional ssh-info (username + connection params) */ 954 if ((cp = strchr(tmp, '@')) != NULL) { 955 char *delim; 956 957 *cp = '\0'; 958 /* Extract username and connection params */ 959 if ((delim = strchr(tmp, ';')) != NULL) { 960 /* Just ignore connection params for now */ 961 *delim = '\0'; 962 } 963 if (*tmp == '\0') { 964 /* Empty username */ 965 goto out; 966 } 967 if ((user = urldecode(tmp)) == NULL) 968 goto out; 969 tmp = cp + 1; 970 } 971 972 /* Extract mandatory hostname */ 973 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 974 goto out; 975 host = xstrdup(cleanhostname(cp)); 976 if (!valid_domain(host, 0, NULL)) 977 goto out; 978 979 if (tmp != NULL && *tmp != '\0') { 980 if (ch == ':') { 981 /* Convert and verify port. */ 982 if ((cp = strchr(tmp, '/')) != NULL) 983 *cp = '\0'; 984 if ((port = a2port(tmp)) <= 0) 985 goto out; 986 tmp = cp ? cp + 1 : NULL; 987 } 988 if (tmp != NULL && *tmp != '\0') { 989 /* Extract optional path */ 990 if ((path = urldecode(tmp)) == NULL) 991 goto out; 992 } 993 } 994 995 /* Success */ 996 if (userp != NULL) { 997 *userp = user; 998 user = NULL; 999 } 1000 if (hostp != NULL) { 1001 *hostp = host; 1002 host = NULL; 1003 } 1004 if (portp != NULL) 1005 *portp = port; 1006 if (pathp != NULL) { 1007 *pathp = path; 1008 path = NULL; 1009 } 1010 ret = 0; 1011 out: 1012 free(uridup); 1013 free(user); 1014 free(host); 1015 free(path); 1016 return ret; 1017 } 1018 1019 /* function to assist building execv() arguments */ 1020 void 1021 addargs(arglist *args, const char *fmt, ...) 1022 { 1023 va_list ap; 1024 char *cp; 1025 u_int nalloc; 1026 int r; 1027 1028 va_start(ap, fmt); 1029 r = vasprintf(&cp, fmt, ap); 1030 va_end(ap); 1031 if (r == -1) 1032 fatal("addargs: argument too long"); 1033 1034 nalloc = args->nalloc; 1035 if (args->list == NULL) { 1036 nalloc = 32; 1037 args->num = 0; 1038 } else if (args->num+2 >= nalloc) 1039 nalloc *= 2; 1040 1041 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 1042 args->nalloc = nalloc; 1043 args->list[args->num++] = cp; 1044 args->list[args->num] = NULL; 1045 } 1046 1047 void 1048 replacearg(arglist *args, u_int which, const char *fmt, ...) 1049 { 1050 va_list ap; 1051 char *cp; 1052 int r; 1053 1054 va_start(ap, fmt); 1055 r = vasprintf(&cp, fmt, ap); 1056 va_end(ap); 1057 if (r == -1) 1058 fatal("replacearg: argument too long"); 1059 1060 if (which >= args->num) 1061 fatal("replacearg: tried to replace invalid arg %d >= %d", 1062 which, args->num); 1063 free(args->list[which]); 1064 args->list[which] = cp; 1065 } 1066 1067 void 1068 freeargs(arglist *args) 1069 { 1070 u_int i; 1071 1072 if (args->list != NULL) { 1073 for (i = 0; i < args->num; i++) 1074 free(args->list[i]); 1075 free(args->list); 1076 args->nalloc = args->num = 0; 1077 args->list = NULL; 1078 } 1079 } 1080 1081 /* 1082 * Expands tildes in the file name. Returns data allocated by xmalloc. 1083 * Warning: this calls getpw*. 1084 */ 1085 int 1086 tilde_expand(const char *filename, uid_t uid, char **retp) 1087 { 1088 const char *path, *sep; 1089 char user[128], *ret, *homedir; 1090 struct passwd *pw; 1091 u_int len, slash; 1092 1093 if (*filename != '~') { 1094 *retp = xstrdup(filename); 1095 return 0; 1096 } 1097 filename++; 1098 1099 path = strchr(filename, '/'); 1100 if (path != NULL && path > filename) { /* ~user/path */ 1101 slash = path - filename; 1102 if (slash > sizeof(user) - 1) { 1103 error_f("~username too long"); 1104 return -1; 1105 } 1106 memcpy(user, filename, slash); 1107 user[slash] = '\0'; 1108 if ((pw = getpwnam(user)) == NULL) { 1109 error_f("No such user %s", user); 1110 return -1; 1111 } 1112 homedir = pw->pw_dir; 1113 } else { 1114 if ((pw = getpwuid(uid)) == NULL) { /* ~/path */ 1115 error_f("No such uid %ld", (long)uid); 1116 return -1; 1117 } 1118 homedir = pw->pw_dir; 1119 } 1120 1121 /* Make sure directory has a trailing '/' */ 1122 len = strlen(homedir); 1123 if (len == 0 || homedir[len - 1] != '/') 1124 sep = "/"; 1125 else 1126 sep = ""; 1127 1128 /* Skip leading '/' from specified path */ 1129 if (path != NULL) 1130 filename = path + 1; 1131 1132 if (xasprintf(&ret, "%s%s%s", homedir, sep, filename) >= PATH_MAX) { 1133 error_f("Path too long"); 1134 return -1; 1135 } 1136 1137 *retp = ret; 1138 return 0; 1139 } 1140 1141 char * 1142 tilde_expand_filename(const char *filename, uid_t uid) 1143 { 1144 char *ret; 1145 1146 if (tilde_expand(filename, uid, &ret) != 0) 1147 cleanup_exit(255); 1148 return ret; 1149 } 1150 1151 /* 1152 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1153 * substitutions. A number of escapes may be specified as 1154 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1155 * by a NULL escape_char. Returns replaced string in memory allocated by 1156 * xmalloc which the caller must free. 1157 */ 1158 static char * 1159 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1160 const char *string, va_list ap) 1161 { 1162 #define EXPAND_MAX_KEYS 16 1163 u_int num_keys = 0, i; 1164 struct { 1165 const char *key; 1166 const char *repl; 1167 } keys[EXPAND_MAX_KEYS]; 1168 struct sshbuf *buf; 1169 int r, missingvar = 0; 1170 char *ret = NULL, *var, *varend, *val; 1171 size_t len; 1172 1173 if ((buf = sshbuf_new()) == NULL) 1174 fatal_f("sshbuf_new failed"); 1175 if (parseerror == NULL) 1176 fatal_f("null parseerror arg"); 1177 *parseerror = 1; 1178 1179 /* Gather keys if we're doing percent expansion. */ 1180 if (percent) { 1181 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1182 keys[num_keys].key = va_arg(ap, char *); 1183 if (keys[num_keys].key == NULL) 1184 break; 1185 keys[num_keys].repl = va_arg(ap, char *); 1186 if (keys[num_keys].repl == NULL) { 1187 fatal_f("NULL replacement for token %s", 1188 keys[num_keys].key); 1189 } 1190 } 1191 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1192 fatal_f("too many keys"); 1193 if (num_keys == 0) 1194 fatal_f("percent expansion without token list"); 1195 } 1196 1197 /* Expand string */ 1198 for (i = 0; *string != '\0'; string++) { 1199 /* Optionally process ${ENVIRONMENT} expansions. */ 1200 if (dollar && string[0] == '$' && string[1] == '{') { 1201 string += 2; /* skip over '${' */ 1202 if ((varend = strchr(string, '}')) == NULL) { 1203 error_f("environment variable '%s' missing " 1204 "closing '}'", string); 1205 goto out; 1206 } 1207 len = varend - string; 1208 if (len == 0) { 1209 error_f("zero-length environment variable"); 1210 goto out; 1211 } 1212 var = xmalloc(len + 1); 1213 (void)strlcpy(var, string, len + 1); 1214 if ((val = getenv(var)) == NULL) { 1215 error_f("env var ${%s} has no value", var); 1216 missingvar = 1; 1217 } else { 1218 debug3_f("expand ${%s} -> '%s'", var, val); 1219 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1220 fatal_fr(r, "sshbuf_put ${}"); 1221 } 1222 free(var); 1223 string += len; 1224 continue; 1225 } 1226 1227 /* 1228 * Process percent expansions if we have a list of TOKENs. 1229 * If we're not doing percent expansion everything just gets 1230 * appended here. 1231 */ 1232 if (*string != '%' || !percent) { 1233 append: 1234 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1235 fatal_fr(r, "sshbuf_put_u8 %%"); 1236 continue; 1237 } 1238 string++; 1239 /* %% case */ 1240 if (*string == '%') 1241 goto append; 1242 if (*string == '\0') { 1243 error_f("invalid format"); 1244 goto out; 1245 } 1246 for (i = 0; i < num_keys; i++) { 1247 if (strchr(keys[i].key, *string) != NULL) { 1248 if ((r = sshbuf_put(buf, keys[i].repl, 1249 strlen(keys[i].repl))) != 0) 1250 fatal_fr(r, "sshbuf_put %%-repl"); 1251 break; 1252 } 1253 } 1254 if (i >= num_keys) { 1255 error_f("unknown key %%%c", *string); 1256 goto out; 1257 } 1258 } 1259 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1260 fatal_f("sshbuf_dup_string failed"); 1261 *parseerror = 0; 1262 out: 1263 sshbuf_free(buf); 1264 return *parseerror ? NULL : ret; 1265 #undef EXPAND_MAX_KEYS 1266 } 1267 1268 /* 1269 * Expand only environment variables. 1270 * Note that although this function is variadic like the other similar 1271 * functions, any such arguments will be unused. 1272 */ 1273 1274 char * 1275 dollar_expand(int *parseerr, const char *string, ...) 1276 { 1277 char *ret; 1278 int err; 1279 va_list ap; 1280 1281 va_start(ap, string); 1282 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1283 va_end(ap); 1284 if (parseerr != NULL) 1285 *parseerr = err; 1286 return ret; 1287 } 1288 1289 /* 1290 * Returns expanded string or NULL if a specified environment variable is 1291 * not defined, or calls fatal if the string is invalid. 1292 */ 1293 char * 1294 percent_expand(const char *string, ...) 1295 { 1296 char *ret; 1297 int err; 1298 va_list ap; 1299 1300 va_start(ap, string); 1301 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1302 va_end(ap); 1303 if (err) 1304 fatal_f("failed"); 1305 return ret; 1306 } 1307 1308 /* 1309 * Returns expanded string or NULL if a specified environment variable is 1310 * not defined, or calls fatal if the string is invalid. 1311 */ 1312 char * 1313 percent_dollar_expand(const char *string, ...) 1314 { 1315 char *ret; 1316 int err; 1317 va_list ap; 1318 1319 va_start(ap, string); 1320 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1321 va_end(ap); 1322 if (err) 1323 fatal_f("failed"); 1324 return ret; 1325 } 1326 1327 int 1328 tun_open(int tun, int mode, char **ifname) 1329 { 1330 struct ifreq ifr; 1331 char name[100]; 1332 int fd = -1, sock; 1333 const char *tunbase = "tun"; 1334 1335 if (ifname != NULL) 1336 *ifname = NULL; 1337 1338 if (mode == SSH_TUNMODE_ETHERNET) 1339 tunbase = "tap"; 1340 1341 /* Open the tunnel device */ 1342 if (tun <= SSH_TUNID_MAX) { 1343 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1344 fd = open(name, O_RDWR); 1345 } else if (tun == SSH_TUNID_ANY) { 1346 for (tun = 100; tun >= 0; tun--) { 1347 snprintf(name, sizeof(name), "/dev/%s%d", 1348 tunbase, tun); 1349 if ((fd = open(name, O_RDWR)) >= 0) 1350 break; 1351 } 1352 } else { 1353 debug_f("invalid tunnel %u", tun); 1354 return -1; 1355 } 1356 1357 if (fd == -1) { 1358 debug_f("%s open: %s", name, strerror(errno)); 1359 return -1; 1360 } 1361 1362 debug_f("%s mode %d fd %d", name, mode, fd); 1363 1364 #ifdef TUNSIFHEAD 1365 /* Turn on tunnel headers */ 1366 int flag = 1; 1367 if (mode != SSH_TUNMODE_ETHERNET && 1368 ioctl(fd, TUNSIFHEAD, &flag) == -1) { 1369 debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd, 1370 strerror(errno)); 1371 close(fd); 1372 return -1; 1373 } 1374 #endif 1375 1376 debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd); 1377 /* Bring interface up if it is not already */ 1378 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1379 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1380 goto failed; 1381 1382 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1383 debug_f("get interface %s flags: %s", ifr.ifr_name, 1384 strerror(errno)); 1385 goto failed; 1386 } 1387 1388 if (!(ifr.ifr_flags & IFF_UP)) { 1389 ifr.ifr_flags |= IFF_UP; 1390 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1391 debug_f("activate interface %s: %s", ifr.ifr_name, 1392 strerror(errno)); 1393 goto failed; 1394 } 1395 } 1396 1397 if (ifname != NULL) 1398 *ifname = xstrdup(ifr.ifr_name); 1399 1400 close(sock); 1401 return fd; 1402 1403 failed: 1404 if (fd >= 0) 1405 close(fd); 1406 if (sock >= 0) 1407 close(sock); 1408 debug("%s: failed to set %s mode %d: %s", __func__, ifr.ifr_name, 1409 mode, strerror(errno)); 1410 return -1; 1411 } 1412 1413 void 1414 sanitise_stdfd(void) 1415 { 1416 int nullfd, dupfd; 1417 1418 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1419 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1420 strerror(errno)); 1421 exit(1); 1422 } 1423 while (++dupfd <= STDERR_FILENO) { 1424 /* Only populate closed fds. */ 1425 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1426 if (dup2(nullfd, dupfd) == -1) { 1427 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1428 exit(1); 1429 } 1430 } 1431 } 1432 if (nullfd > STDERR_FILENO) 1433 close(nullfd); 1434 } 1435 1436 char * 1437 tohex(const void *vp, size_t l) 1438 { 1439 const u_char *p = (const u_char *)vp; 1440 char b[3], *r; 1441 size_t i, hl; 1442 1443 if (l > 65536) 1444 return xstrdup("tohex: length > 65536"); 1445 1446 hl = l * 2 + 1; 1447 r = xcalloc(1, hl); 1448 for (i = 0; i < l; i++) { 1449 snprintf(b, sizeof(b), "%02x", p[i]); 1450 strlcat(r, b, hl); 1451 } 1452 return (r); 1453 } 1454 1455 /* 1456 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1457 * then the separator 'sep' will be prepended before the formatted arguments. 1458 * Extended strings are heap allocated. 1459 */ 1460 void 1461 xextendf(char **sp, const char *sep, const char *fmt, ...) 1462 { 1463 va_list ap; 1464 char *tmp1, *tmp2; 1465 1466 va_start(ap, fmt); 1467 xvasprintf(&tmp1, fmt, ap); 1468 va_end(ap); 1469 1470 if (*sp == NULL || **sp == '\0') { 1471 free(*sp); 1472 *sp = tmp1; 1473 return; 1474 } 1475 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1476 free(tmp1); 1477 free(*sp); 1478 *sp = tmp2; 1479 } 1480 1481 1482 u_int64_t 1483 get_u64(const void *vp) 1484 { 1485 const u_char *p = (const u_char *)vp; 1486 u_int64_t v; 1487 1488 v = (u_int64_t)p[0] << 56; 1489 v |= (u_int64_t)p[1] << 48; 1490 v |= (u_int64_t)p[2] << 40; 1491 v |= (u_int64_t)p[3] << 32; 1492 v |= (u_int64_t)p[4] << 24; 1493 v |= (u_int64_t)p[5] << 16; 1494 v |= (u_int64_t)p[6] << 8; 1495 v |= (u_int64_t)p[7]; 1496 1497 return (v); 1498 } 1499 1500 u_int32_t 1501 get_u32(const void *vp) 1502 { 1503 const u_char *p = (const u_char *)vp; 1504 u_int32_t v; 1505 1506 v = (u_int32_t)p[0] << 24; 1507 v |= (u_int32_t)p[1] << 16; 1508 v |= (u_int32_t)p[2] << 8; 1509 v |= (u_int32_t)p[3]; 1510 1511 return (v); 1512 } 1513 1514 u_int32_t 1515 get_u32_le(const void *vp) 1516 { 1517 const u_char *p = (const u_char *)vp; 1518 u_int32_t v; 1519 1520 v = (u_int32_t)p[0]; 1521 v |= (u_int32_t)p[1] << 8; 1522 v |= (u_int32_t)p[2] << 16; 1523 v |= (u_int32_t)p[3] << 24; 1524 1525 return (v); 1526 } 1527 1528 u_int16_t 1529 get_u16(const void *vp) 1530 { 1531 const u_char *p = (const u_char *)vp; 1532 u_int16_t v; 1533 1534 v = (u_int16_t)p[0] << 8; 1535 v |= (u_int16_t)p[1]; 1536 1537 return (v); 1538 } 1539 1540 void 1541 put_u64(void *vp, u_int64_t v) 1542 { 1543 u_char *p = (u_char *)vp; 1544 1545 p[0] = (u_char)(v >> 56) & 0xff; 1546 p[1] = (u_char)(v >> 48) & 0xff; 1547 p[2] = (u_char)(v >> 40) & 0xff; 1548 p[3] = (u_char)(v >> 32) & 0xff; 1549 p[4] = (u_char)(v >> 24) & 0xff; 1550 p[5] = (u_char)(v >> 16) & 0xff; 1551 p[6] = (u_char)(v >> 8) & 0xff; 1552 p[7] = (u_char)v & 0xff; 1553 } 1554 1555 void 1556 put_u32(void *vp, u_int32_t v) 1557 { 1558 u_char *p = (u_char *)vp; 1559 1560 p[0] = (u_char)(v >> 24) & 0xff; 1561 p[1] = (u_char)(v >> 16) & 0xff; 1562 p[2] = (u_char)(v >> 8) & 0xff; 1563 p[3] = (u_char)v & 0xff; 1564 } 1565 1566 void 1567 put_u32_le(void *vp, u_int32_t v) 1568 { 1569 u_char *p = (u_char *)vp; 1570 1571 p[0] = (u_char)v & 0xff; 1572 p[1] = (u_char)(v >> 8) & 0xff; 1573 p[2] = (u_char)(v >> 16) & 0xff; 1574 p[3] = (u_char)(v >> 24) & 0xff; 1575 } 1576 1577 void 1578 put_u16(void *vp, u_int16_t v) 1579 { 1580 u_char *p = (u_char *)vp; 1581 1582 p[0] = (u_char)(v >> 8) & 0xff; 1583 p[1] = (u_char)v & 0xff; 1584 } 1585 1586 void 1587 ms_subtract_diff(struct timeval *start, int *ms) 1588 { 1589 struct timeval diff, finish; 1590 1591 monotime_tv(&finish); 1592 timersub(&finish, start, &diff); 1593 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1594 } 1595 1596 void 1597 ms_to_timeval(struct timeval *tv, int ms) 1598 { 1599 if (ms < 0) 1600 ms = 0; 1601 tv->tv_sec = ms / 1000; 1602 tv->tv_usec = (ms % 1000) * 1000; 1603 } 1604 1605 void 1606 monotime_ts(struct timespec *ts) 1607 { 1608 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1609 fatal("clock_gettime: %s", strerror(errno)); 1610 } 1611 1612 void 1613 monotime_tv(struct timeval *tv) 1614 { 1615 struct timespec ts; 1616 1617 monotime_ts(&ts); 1618 tv->tv_sec = ts.tv_sec; 1619 tv->tv_usec = ts.tv_nsec / 1000; 1620 } 1621 1622 time_t 1623 monotime(void) 1624 { 1625 struct timespec ts; 1626 1627 monotime_ts(&ts); 1628 return (ts.tv_sec); 1629 } 1630 1631 double 1632 monotime_double(void) 1633 { 1634 struct timespec ts; 1635 1636 monotime_ts(&ts); 1637 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1638 } 1639 1640 void 1641 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1642 { 1643 bw->buflen = buflen; 1644 bw->rate = kbps; 1645 bw->thresh = buflen; 1646 bw->lamt = 0; 1647 timerclear(&bw->bwstart); 1648 timerclear(&bw->bwend); 1649 } 1650 1651 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1652 void 1653 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1654 { 1655 u_int64_t waitlen; 1656 struct timespec ts, rm; 1657 1658 bw->lamt += read_len; 1659 if (!timerisset(&bw->bwstart)) { 1660 monotime_tv(&bw->bwstart); 1661 return; 1662 } 1663 if (bw->lamt < bw->thresh) 1664 return; 1665 1666 monotime_tv(&bw->bwend); 1667 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1668 if (!timerisset(&bw->bwend)) 1669 return; 1670 1671 bw->lamt *= 8; 1672 waitlen = (double)1000000L * bw->lamt / bw->rate; 1673 1674 bw->bwstart.tv_sec = waitlen / 1000000L; 1675 bw->bwstart.tv_usec = waitlen % 1000000L; 1676 1677 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1678 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1679 1680 /* Adjust the wait time */ 1681 if (bw->bwend.tv_sec) { 1682 bw->thresh /= 2; 1683 if (bw->thresh < bw->buflen / 4) 1684 bw->thresh = bw->buflen / 4; 1685 } else if (bw->bwend.tv_usec < 10000) { 1686 bw->thresh *= 2; 1687 if (bw->thresh > bw->buflen * 8) 1688 bw->thresh = bw->buflen * 8; 1689 } 1690 1691 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1692 while (nanosleep(&ts, &rm) == -1) { 1693 if (errno != EINTR) 1694 break; 1695 ts = rm; 1696 } 1697 } 1698 1699 bw->lamt = 0; 1700 monotime_tv(&bw->bwstart); 1701 } 1702 1703 /* Make a template filename for mk[sd]temp() */ 1704 void 1705 mktemp_proto(char *s, size_t len) 1706 { 1707 const char *tmpdir; 1708 int r; 1709 1710 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1711 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1712 if (r > 0 && (size_t)r < len) 1713 return; 1714 } 1715 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1716 if (r < 0 || (size_t)r >= len) 1717 fatal_f("template string too short"); 1718 } 1719 1720 static const struct { 1721 const char *name; 1722 int value; 1723 } ipqos[] = { 1724 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1725 { "af11", IPTOS_DSCP_AF11 }, 1726 { "af12", IPTOS_DSCP_AF12 }, 1727 { "af13", IPTOS_DSCP_AF13 }, 1728 { "af21", IPTOS_DSCP_AF21 }, 1729 { "af22", IPTOS_DSCP_AF22 }, 1730 { "af23", IPTOS_DSCP_AF23 }, 1731 { "af31", IPTOS_DSCP_AF31 }, 1732 { "af32", IPTOS_DSCP_AF32 }, 1733 { "af33", IPTOS_DSCP_AF33 }, 1734 { "af41", IPTOS_DSCP_AF41 }, 1735 { "af42", IPTOS_DSCP_AF42 }, 1736 { "af43", IPTOS_DSCP_AF43 }, 1737 { "cs0", IPTOS_DSCP_CS0 }, 1738 { "cs1", IPTOS_DSCP_CS1 }, 1739 { "cs2", IPTOS_DSCP_CS2 }, 1740 { "cs3", IPTOS_DSCP_CS3 }, 1741 { "cs4", IPTOS_DSCP_CS4 }, 1742 { "cs5", IPTOS_DSCP_CS5 }, 1743 { "cs6", IPTOS_DSCP_CS6 }, 1744 { "cs7", IPTOS_DSCP_CS7 }, 1745 { "ef", IPTOS_DSCP_EF }, 1746 #ifdef IPTOS_DSCP_LE 1747 { "le", IPTOS_DSCP_LE }, 1748 #endif 1749 { "lowdelay", IPTOS_LOWDELAY }, 1750 { "throughput", IPTOS_THROUGHPUT }, 1751 { "reliability", IPTOS_RELIABILITY }, 1752 { NULL, -1 } 1753 }; 1754 1755 int 1756 parse_ipqos(const char *cp) 1757 { 1758 u_int i; 1759 char *ep; 1760 long val; 1761 1762 if (cp == NULL) 1763 return -1; 1764 for (i = 0; ipqos[i].name != NULL; i++) { 1765 if (strcasecmp(cp, ipqos[i].name) == 0) 1766 return ipqos[i].value; 1767 } 1768 /* Try parsing as an integer */ 1769 val = strtol(cp, &ep, 0); 1770 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1771 return -1; 1772 return val; 1773 } 1774 1775 const char * 1776 iptos2str(int iptos) 1777 { 1778 int i; 1779 static char iptos_str[sizeof "0xff"]; 1780 1781 for (i = 0; ipqos[i].name != NULL; i++) { 1782 if (ipqos[i].value == iptos) 1783 return ipqos[i].name; 1784 } 1785 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1786 return iptos_str; 1787 } 1788 1789 void 1790 lowercase(char *s) 1791 { 1792 for (; *s; s++) 1793 *s = tolower((u_char)*s); 1794 } 1795 1796 int 1797 unix_listener(const char *path, int backlog, int unlink_first) 1798 { 1799 struct sockaddr_un sunaddr; 1800 int saved_errno, sock; 1801 1802 memset(&sunaddr, 0, sizeof(sunaddr)); 1803 sunaddr.sun_family = AF_UNIX; 1804 if (strlcpy(sunaddr.sun_path, path, 1805 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1806 error_f("path \"%s\" too long for Unix domain socket", path); 1807 errno = ENAMETOOLONG; 1808 return -1; 1809 } 1810 1811 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1812 if (sock == -1) { 1813 saved_errno = errno; 1814 error_f("socket: %.100s", strerror(errno)); 1815 errno = saved_errno; 1816 return -1; 1817 } 1818 if (unlink_first == 1) { 1819 if (unlink(path) != 0 && errno != ENOENT) 1820 error("unlink(%s): %.100s", path, strerror(errno)); 1821 } 1822 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1823 saved_errno = errno; 1824 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1825 close(sock); 1826 errno = saved_errno; 1827 return -1; 1828 } 1829 if (listen(sock, backlog) == -1) { 1830 saved_errno = errno; 1831 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1832 close(sock); 1833 unlink(path); 1834 errno = saved_errno; 1835 return -1; 1836 } 1837 return sock; 1838 } 1839 1840 /* 1841 * Compares two strings that maybe be NULL. Returns non-zero if strings 1842 * are both NULL or are identical, returns zero otherwise. 1843 */ 1844 static int 1845 strcmp_maybe_null(const char *a, const char *b) 1846 { 1847 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1848 return 0; 1849 if (a != NULL && strcmp(a, b) != 0) 1850 return 0; 1851 return 1; 1852 } 1853 1854 /* 1855 * Compare two forwards, returning non-zero if they are identical or 1856 * zero otherwise. 1857 */ 1858 int 1859 forward_equals(const struct Forward *a, const struct Forward *b) 1860 { 1861 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1862 return 0; 1863 if (a->listen_port != b->listen_port) 1864 return 0; 1865 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1866 return 0; 1867 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1868 return 0; 1869 if (a->connect_port != b->connect_port) 1870 return 0; 1871 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1872 return 0; 1873 /* allocated_port and handle are not checked */ 1874 return 1; 1875 } 1876 1877 /* returns 1 if process is already daemonized, 0 otherwise */ 1878 int 1879 daemonized(void) 1880 { 1881 int fd; 1882 1883 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1884 close(fd); 1885 return 0; /* have controlling terminal */ 1886 } 1887 if (getppid() != 1) 1888 return 0; /* parent is not init */ 1889 if (getsid(0) != getpid()) 1890 return 0; /* not session leader */ 1891 debug3("already daemonized"); 1892 return 1; 1893 } 1894 1895 /* 1896 * Splits 's' into an argument vector. Handles quoted string and basic 1897 * escape characters (\\, \", \'). Caller must free the argument vector 1898 * and its members. 1899 */ 1900 int 1901 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1902 { 1903 int r = SSH_ERR_INTERNAL_ERROR; 1904 int argc = 0, quote, i, j; 1905 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1906 1907 *argvp = NULL; 1908 *argcp = 0; 1909 1910 for (i = 0; s[i] != '\0'; i++) { 1911 /* Skip leading whitespace */ 1912 if (s[i] == ' ' || s[i] == '\t') 1913 continue; 1914 if (terminate_on_comment && s[i] == '#') 1915 break; 1916 /* Start of a token */ 1917 quote = 0; 1918 1919 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1920 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1921 argv[argc] = NULL; 1922 1923 /* Copy the token in, removing escapes */ 1924 for (j = 0; s[i] != '\0'; i++) { 1925 if (s[i] == '\\') { 1926 if (s[i + 1] == '\'' || 1927 s[i + 1] == '\"' || 1928 s[i + 1] == '\\' || 1929 (quote == 0 && s[i + 1] == ' ')) { 1930 i++; /* Skip '\' */ 1931 arg[j++] = s[i]; 1932 } else { 1933 /* Unrecognised escape */ 1934 arg[j++] = s[i]; 1935 } 1936 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1937 break; /* done */ 1938 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1939 quote = s[i]; /* quote start */ 1940 else if (quote != 0 && s[i] == quote) 1941 quote = 0; /* quote end */ 1942 else 1943 arg[j++] = s[i]; 1944 } 1945 if (s[i] == '\0') { 1946 if (quote != 0) { 1947 /* Ran out of string looking for close quote */ 1948 r = SSH_ERR_INVALID_FORMAT; 1949 goto out; 1950 } 1951 break; 1952 } 1953 } 1954 /* Success */ 1955 *argcp = argc; 1956 *argvp = argv; 1957 argc = 0; 1958 argv = NULL; 1959 r = 0; 1960 out: 1961 if (argc != 0 && argv != NULL) { 1962 for (i = 0; i < argc; i++) 1963 free(argv[i]); 1964 free(argv); 1965 } 1966 return r; 1967 } 1968 1969 /* 1970 * Reassemble an argument vector into a string, quoting and escaping as 1971 * necessary. Caller must free returned string. 1972 */ 1973 char * 1974 argv_assemble(int argc, char **argv) 1975 { 1976 int i, j, ws, r; 1977 char c, *ret; 1978 struct sshbuf *buf, *arg; 1979 1980 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1981 fatal_f("sshbuf_new failed"); 1982 1983 for (i = 0; i < argc; i++) { 1984 ws = 0; 1985 sshbuf_reset(arg); 1986 for (j = 0; argv[i][j] != '\0'; j++) { 1987 r = 0; 1988 c = argv[i][j]; 1989 switch (c) { 1990 case ' ': 1991 case '\t': 1992 ws = 1; 1993 r = sshbuf_put_u8(arg, c); 1994 break; 1995 case '\\': 1996 case '\'': 1997 case '"': 1998 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 1999 break; 2000 /* FALLTHROUGH */ 2001 default: 2002 r = sshbuf_put_u8(arg, c); 2003 break; 2004 } 2005 if (r != 0) 2006 fatal_fr(r, "sshbuf_put_u8"); 2007 } 2008 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2009 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2010 (r = sshbuf_putb(buf, arg)) != 0 || 2011 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2012 fatal_fr(r, "assemble"); 2013 } 2014 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2015 fatal_f("malloc failed"); 2016 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2017 ret[sshbuf_len(buf)] = '\0'; 2018 sshbuf_free(buf); 2019 sshbuf_free(arg); 2020 return ret; 2021 } 2022 2023 char * 2024 argv_next(int *argcp, char ***argvp) 2025 { 2026 char *ret = (*argvp)[0]; 2027 2028 if (*argcp > 0 && ret != NULL) { 2029 (*argcp)--; 2030 (*argvp)++; 2031 } 2032 return ret; 2033 } 2034 2035 void 2036 argv_consume(int *argcp) 2037 { 2038 *argcp = 0; 2039 } 2040 2041 void 2042 argv_free(char **av, int ac) 2043 { 2044 int i; 2045 2046 if (av == NULL) 2047 return; 2048 for (i = 0; i < ac; i++) 2049 free(av[i]); 2050 free(av); 2051 } 2052 2053 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2054 int 2055 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2056 { 2057 int status; 2058 2059 while (waitpid(pid, &status, 0) == -1) { 2060 if (errno != EINTR) { 2061 error("%s waitpid: %s", tag, strerror(errno)); 2062 return -1; 2063 } 2064 } 2065 if (WIFSIGNALED(status)) { 2066 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2067 return -1; 2068 } else if (WEXITSTATUS(status) != 0) { 2069 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2070 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2071 return -1; 2072 } 2073 return 0; 2074 } 2075 2076 /* 2077 * Check a given path for security. This is defined as all components 2078 * of the path to the file must be owned by either the owner of 2079 * of the file or root and no directories must be group or world writable. 2080 * 2081 * XXX Should any specific check be done for sym links ? 2082 * 2083 * Takes a file name, its stat information (preferably from fstat() to 2084 * avoid races), the uid of the expected owner, their home directory and an 2085 * error buffer plus max size as arguments. 2086 * 2087 * Returns 0 on success and -1 on failure 2088 */ 2089 int 2090 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2091 uid_t uid, char *err, size_t errlen) 2092 { 2093 char buf[PATH_MAX], homedir[PATH_MAX]; 2094 char *cp; 2095 int comparehome = 0; 2096 struct stat st; 2097 2098 if (realpath(name, buf) == NULL) { 2099 snprintf(err, errlen, "realpath %s failed: %s", name, 2100 strerror(errno)); 2101 return -1; 2102 } 2103 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2104 comparehome = 1; 2105 2106 if (!S_ISREG(stp->st_mode)) { 2107 snprintf(err, errlen, "%s is not a regular file", buf); 2108 return -1; 2109 } 2110 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2111 (stp->st_mode & 022) != 0) { 2112 snprintf(err, errlen, "bad ownership or modes for file %s", 2113 buf); 2114 return -1; 2115 } 2116 2117 /* for each component of the canonical path, walking upwards */ 2118 for (;;) { 2119 if ((cp = dirname(buf)) == NULL) { 2120 snprintf(err, errlen, "dirname() failed"); 2121 return -1; 2122 } 2123 strlcpy(buf, cp, sizeof(buf)); 2124 2125 if (stat(buf, &st) == -1 || 2126 (st.st_uid != 0 && st.st_uid != uid) || 2127 (st.st_mode & 022) != 0) { 2128 snprintf(err, errlen, 2129 "bad ownership or modes for directory %s", buf); 2130 return -1; 2131 } 2132 2133 /* If are past the homedir then we can stop */ 2134 if (comparehome && strcmp(homedir, buf) == 0) 2135 break; 2136 2137 /* 2138 * dirname should always complete with a "/" path, 2139 * but we can be paranoid and check for "." too 2140 */ 2141 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2142 break; 2143 } 2144 return 0; 2145 } 2146 2147 /* 2148 * Version of safe_path() that accepts an open file descriptor to 2149 * avoid races. 2150 * 2151 * Returns 0 on success and -1 on failure 2152 */ 2153 int 2154 safe_path_fd(int fd, const char *file, struct passwd *pw, 2155 char *err, size_t errlen) 2156 { 2157 struct stat st; 2158 2159 /* check the open file to avoid races */ 2160 if (fstat(fd, &st) == -1) { 2161 snprintf(err, errlen, "cannot stat file %s: %s", 2162 file, strerror(errno)); 2163 return -1; 2164 } 2165 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2166 } 2167 2168 /* 2169 * Sets the value of the given variable in the environment. If the variable 2170 * already exists, its value is overridden. 2171 */ 2172 void 2173 child_set_env(char ***envp, u_int *envsizep, const char *name, 2174 const char *value) 2175 { 2176 char **env; 2177 u_int envsize; 2178 u_int i, namelen; 2179 2180 if (strchr(name, '=') != NULL) { 2181 error("Invalid environment variable \"%.100s\"", name); 2182 return; 2183 } 2184 2185 /* 2186 * Find the slot where the value should be stored. If the variable 2187 * already exists, we reuse the slot; otherwise we append a new slot 2188 * at the end of the array, expanding if necessary. 2189 */ 2190 env = *envp; 2191 namelen = strlen(name); 2192 for (i = 0; env[i]; i++) 2193 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2194 break; 2195 if (env[i]) { 2196 /* Reuse the slot. */ 2197 free(env[i]); 2198 } else { 2199 /* New variable. Expand if necessary. */ 2200 envsize = *envsizep; 2201 if (i >= envsize - 1) { 2202 if (envsize >= 1000) 2203 fatal("child_set_env: too many env vars"); 2204 envsize += 50; 2205 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2206 *envsizep = envsize; 2207 } 2208 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2209 env[i + 1] = NULL; 2210 } 2211 2212 /* Allocate space and format the variable in the appropriate slot. */ 2213 /* XXX xasprintf */ 2214 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2215 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2216 } 2217 2218 /* 2219 * Check and optionally lowercase a domain name, also removes trailing '.' 2220 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2221 */ 2222 int 2223 valid_domain(char *name, int makelower, const char **errstr) 2224 { 2225 size_t i, l = strlen(name); 2226 u_char c, last = '\0'; 2227 static char errbuf[256]; 2228 2229 if (l == 0) { 2230 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2231 goto bad; 2232 } 2233 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2234 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2235 "starts with invalid character", name); 2236 goto bad; 2237 } 2238 for (i = 0; i < l; i++) { 2239 c = tolower((u_char)name[i]); 2240 if (makelower) 2241 name[i] = (char)c; 2242 if (last == '.' && c == '.') { 2243 snprintf(errbuf, sizeof(errbuf), "domain name " 2244 "\"%.100s\" contains consecutive separators", name); 2245 goto bad; 2246 } 2247 if (c != '.' && c != '-' && !isalnum(c) && 2248 c != '_') /* technically invalid, but common */ { 2249 snprintf(errbuf, sizeof(errbuf), "domain name " 2250 "\"%.100s\" contains invalid characters", name); 2251 goto bad; 2252 } 2253 last = c; 2254 } 2255 if (name[l - 1] == '.') 2256 name[l - 1] = '\0'; 2257 if (errstr != NULL) 2258 *errstr = NULL; 2259 return 1; 2260 bad: 2261 if (errstr != NULL) 2262 *errstr = errbuf; 2263 return 0; 2264 } 2265 2266 /* 2267 * Verify that a environment variable name (not including initial '$') is 2268 * valid; consisting of one or more alphanumeric or underscore characters only. 2269 * Returns 1 on valid, 0 otherwise. 2270 */ 2271 int 2272 valid_env_name(const char *name) 2273 { 2274 const char *cp; 2275 2276 if (name[0] == '\0') 2277 return 0; 2278 for (cp = name; *cp != '\0'; cp++) { 2279 if (!isalnum((u_char)*cp) && *cp != '_') 2280 return 0; 2281 } 2282 return 1; 2283 } 2284 2285 const char * 2286 atoi_err(const char *nptr, int *val) 2287 { 2288 const char *errstr = NULL; 2289 long long num; 2290 2291 if (nptr == NULL || *nptr == '\0') 2292 return "missing"; 2293 num = strtonum(nptr, 0, INT_MAX, &errstr); 2294 if (errstr == NULL) 2295 *val = (int)num; 2296 return errstr; 2297 } 2298 2299 int 2300 parse_absolute_time(const char *s, uint64_t *tp) 2301 { 2302 struct tm tm; 2303 time_t tt; 2304 char buf[32]; 2305 const char *fmt; 2306 2307 *tp = 0; 2308 2309 /* 2310 * POSIX strptime says "The application shall ensure that there 2311 * is white-space or other non-alphanumeric characters between 2312 * any two conversion specifications" so arrange things this way. 2313 */ 2314 switch (strlen(s)) { 2315 case 8: /* YYYYMMDD */ 2316 fmt = "%Y-%m-%d"; 2317 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2318 break; 2319 case 12: /* YYYYMMDDHHMM */ 2320 fmt = "%Y-%m-%dT%H:%M"; 2321 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2322 s, s + 4, s + 6, s + 8, s + 10); 2323 break; 2324 case 14: /* YYYYMMDDHHMMSS */ 2325 fmt = "%Y-%m-%dT%H:%M:%S"; 2326 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2327 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2328 break; 2329 default: 2330 return SSH_ERR_INVALID_FORMAT; 2331 } 2332 2333 memset(&tm, 0, sizeof(tm)); 2334 if (strptime(buf, fmt, &tm) == NULL) 2335 return SSH_ERR_INVALID_FORMAT; 2336 if ((tt = mktime(&tm)) < 0) 2337 return SSH_ERR_INVALID_FORMAT; 2338 /* success */ 2339 *tp = (uint64_t)tt; 2340 return 0; 2341 } 2342 2343 /* On OpenBSD time_t is int64_t which is long long. */ 2344 #define SSH_TIME_T_MAX LLONG_MAX 2345 2346 void 2347 format_absolute_time(uint64_t t, char *buf, size_t len) 2348 { 2349 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2350 struct tm tm; 2351 2352 localtime_r(&tt, &tm); 2353 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2354 } 2355 2356 /* check if path is absolute */ 2357 int 2358 path_absolute(const char *path) 2359 { 2360 return (*path == '/') ? 1 : 0; 2361 } 2362 2363 void 2364 skip_space(char **cpp) 2365 { 2366 char *cp; 2367 2368 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2369 ; 2370 *cpp = cp; 2371 } 2372 2373 /* authorized_key-style options parsing helpers */ 2374 2375 /* 2376 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2377 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2378 * if negated option matches. 2379 * If the option or negated option matches, then *optsp is updated to 2380 * point to the first character after the option. 2381 */ 2382 int 2383 opt_flag(const char *opt, int allow_negate, const char **optsp) 2384 { 2385 size_t opt_len = strlen(opt); 2386 const char *opts = *optsp; 2387 int negate = 0; 2388 2389 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2390 opts += 3; 2391 negate = 1; 2392 } 2393 if (strncasecmp(opts, opt, opt_len) == 0) { 2394 *optsp = opts + opt_len; 2395 return negate ? 0 : 1; 2396 } 2397 return -1; 2398 } 2399 2400 char * 2401 opt_dequote(const char **sp, const char **errstrp) 2402 { 2403 const char *s = *sp; 2404 char *ret; 2405 size_t i; 2406 2407 *errstrp = NULL; 2408 if (*s != '"') { 2409 *errstrp = "missing start quote"; 2410 return NULL; 2411 } 2412 s++; 2413 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2414 *errstrp = "memory allocation failed"; 2415 return NULL; 2416 } 2417 for (i = 0; *s != '\0' && *s != '"';) { 2418 if (s[0] == '\\' && s[1] == '"') 2419 s++; 2420 ret[i++] = *s++; 2421 } 2422 if (*s == '\0') { 2423 *errstrp = "missing end quote"; 2424 free(ret); 2425 return NULL; 2426 } 2427 ret[i] = '\0'; 2428 s++; 2429 *sp = s; 2430 return ret; 2431 } 2432 2433 int 2434 opt_match(const char **opts, const char *term) 2435 { 2436 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2437 (*opts)[strlen(term)] == '=') { 2438 *opts += strlen(term) + 1; 2439 return 1; 2440 } 2441 return 0; 2442 } 2443 2444 void 2445 opt_array_append2(const char *file, const int line, const char *directive, 2446 char ***array, int **iarray, u_int *lp, const char *s, int i) 2447 { 2448 2449 if (*lp >= INT_MAX) 2450 fatal("%s line %d: Too many %s entries", file, line, directive); 2451 2452 if (iarray != NULL) { 2453 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2454 sizeof(**iarray)); 2455 (*iarray)[*lp] = i; 2456 } 2457 2458 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2459 (*array)[*lp] = xstrdup(s); 2460 (*lp)++; 2461 } 2462 2463 void 2464 opt_array_append(const char *file, const int line, const char *directive, 2465 char ***array, u_int *lp, const char *s) 2466 { 2467 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2468 } 2469 2470 sshsig_t 2471 ssh_signal(int signum, sshsig_t handler) 2472 { 2473 struct sigaction sa, osa; 2474 2475 /* mask all other signals while in handler */ 2476 memset(&sa, 0, sizeof(sa)); 2477 sa.sa_handler = handler; 2478 sigfillset(&sa.sa_mask); 2479 if (signum != SIGALRM) 2480 sa.sa_flags = SA_RESTART; 2481 if (sigaction(signum, &sa, &osa) == -1) { 2482 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2483 return SIG_ERR; 2484 } 2485 return osa.sa_handler; 2486 } 2487 2488 int 2489 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2490 { 2491 int devnull, ret = 0; 2492 2493 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2494 error_f("open %s: %s", _PATH_DEVNULL, 2495 strerror(errno)); 2496 return -1; 2497 } 2498 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2499 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2500 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2501 error_f("dup2: %s", strerror(errno)); 2502 ret = -1; 2503 } 2504 if (devnull > STDERR_FILENO) 2505 close(devnull); 2506 return ret; 2507 } 2508 2509 /* 2510 * Runs command in a subprocess with a minimal environment. 2511 * Returns pid on success, 0 on failure. 2512 * The child stdout and stderr maybe captured, left attached or sent to 2513 * /dev/null depending on the contents of flags. 2514 * "tag" is prepended to log messages. 2515 * NB. "command" is only used for logging; the actual command executed is 2516 * av[0]. 2517 */ 2518 pid_t 2519 subprocess(const char *tag, const char *command, 2520 int ac, char **av, FILE **child, u_int flags, 2521 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2522 { 2523 FILE *f = NULL; 2524 struct stat st; 2525 int fd, devnull, p[2], i; 2526 pid_t pid; 2527 char *cp, errmsg[512]; 2528 u_int nenv = 0; 2529 char **env = NULL; 2530 2531 /* If dropping privs, then must specify user and restore function */ 2532 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2533 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2534 return 0; 2535 } 2536 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2537 error("%s: no user for current uid", tag); 2538 return 0; 2539 } 2540 if (child != NULL) 2541 *child = NULL; 2542 2543 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2544 tag, command, pw->pw_name, flags); 2545 2546 /* Check consistency */ 2547 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2548 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2549 error_f("inconsistent flags"); 2550 return 0; 2551 } 2552 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2553 error_f("inconsistent flags/output"); 2554 return 0; 2555 } 2556 2557 /* 2558 * If executing an explicit binary, then verify the it exists 2559 * and appears safe-ish to execute 2560 */ 2561 if (!path_absolute(av[0])) { 2562 error("%s path is not absolute", tag); 2563 return 0; 2564 } 2565 if (drop_privs != NULL) 2566 drop_privs(pw); 2567 if (stat(av[0], &st) == -1) { 2568 error("Could not stat %s \"%s\": %s", tag, 2569 av[0], strerror(errno)); 2570 goto restore_return; 2571 } 2572 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2573 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2574 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2575 goto restore_return; 2576 } 2577 /* Prepare to keep the child's stdout if requested */ 2578 if (pipe(p) == -1) { 2579 error("%s: pipe: %s", tag, strerror(errno)); 2580 restore_return: 2581 if (restore_privs != NULL) 2582 restore_privs(); 2583 return 0; 2584 } 2585 if (restore_privs != NULL) 2586 restore_privs(); 2587 2588 switch ((pid = fork())) { 2589 case -1: /* error */ 2590 error("%s: fork: %s", tag, strerror(errno)); 2591 close(p[0]); 2592 close(p[1]); 2593 return 0; 2594 case 0: /* child */ 2595 /* Prepare a minimal environment for the child. */ 2596 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2597 nenv = 5; 2598 env = xcalloc(sizeof(*env), nenv); 2599 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2600 child_set_env(&env, &nenv, "USER", pw->pw_name); 2601 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2602 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2603 if ((cp = getenv("LANG")) != NULL) 2604 child_set_env(&env, &nenv, "LANG", cp); 2605 } 2606 2607 for (i = 1; i < NSIG; i++) 2608 ssh_signal(i, SIG_DFL); 2609 2610 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2611 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2612 strerror(errno)); 2613 _exit(1); 2614 } 2615 if (dup2(devnull, STDIN_FILENO) == -1) { 2616 error("%s: dup2: %s", tag, strerror(errno)); 2617 _exit(1); 2618 } 2619 2620 /* Set up stdout as requested; leave stderr in place for now. */ 2621 fd = -1; 2622 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2623 fd = p[1]; 2624 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2625 fd = devnull; 2626 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2627 error("%s: dup2: %s", tag, strerror(errno)); 2628 _exit(1); 2629 } 2630 closefrom(STDERR_FILENO + 1); 2631 2632 #ifdef __NetBSD__ 2633 #define setresgid(a, b, c) setgid(a) 2634 #define setresuid(a, b, c) setuid(a) 2635 #endif 2636 2637 if (geteuid() == 0 && 2638 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2639 error("%s: initgroups(%s, %u): %s", tag, 2640 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2641 _exit(1); 2642 } 2643 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2644 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2645 strerror(errno)); 2646 _exit(1); 2647 } 2648 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2649 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2650 strerror(errno)); 2651 _exit(1); 2652 } 2653 /* stdin is pointed to /dev/null at this point */ 2654 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2655 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2656 error("%s: dup2: %s", tag, strerror(errno)); 2657 _exit(1); 2658 } 2659 if (env != NULL) 2660 execve(av[0], av, env); 2661 else 2662 execv(av[0], av); 2663 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2664 command, strerror(errno)); 2665 _exit(127); 2666 default: /* parent */ 2667 break; 2668 } 2669 2670 close(p[1]); 2671 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2672 close(p[0]); 2673 else if ((f = fdopen(p[0], "r")) == NULL) { 2674 error("%s: fdopen: %s", tag, strerror(errno)); 2675 close(p[0]); 2676 /* Don't leave zombie child */ 2677 kill(pid, SIGTERM); 2678 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2679 ; 2680 return 0; 2681 } 2682 /* Success */ 2683 debug3_f("%s pid %ld", tag, (long)pid); 2684 if (child != NULL) 2685 *child = f; 2686 return pid; 2687 } 2688 2689 const char * 2690 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2691 { 2692 size_t i, envlen; 2693 2694 envlen = strlen(env); 2695 for (i = 0; i < nenvs; i++) { 2696 if (strncmp(envs[i], env, envlen) == 0 && 2697 envs[i][envlen] == '=') { 2698 return envs[i] + envlen + 1; 2699 } 2700 } 2701 return NULL; 2702 } 2703