1 /* $NetBSD: misc.c,v 1.33 2023/07/26 17:58:15 christos Exp $ */ 2 /* $OpenBSD: misc.c,v 1.181 2023/03/03 02:37:58 dtucker Exp $ */ 3 /* 4 * Copyright (c) 2000 Markus Friedl. All rights reserved. 5 * Copyright (c) 2005-2020 Damien Miller. All rights reserved. 6 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org> 7 * 8 * Permission to use, copy, modify, and distribute this software for any 9 * purpose with or without fee is hereby granted, provided that the above 10 * copyright notice and this permission notice appear in all copies. 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 19 */ 20 21 #include "includes.h" 22 __RCSID("$NetBSD: misc.c,v 1.33 2023/07/26 17:58:15 christos Exp $"); 23 24 #include <sys/types.h> 25 #include <sys/ioctl.h> 26 #include <sys/socket.h> 27 #include <sys/stat.h> 28 #include <sys/time.h> 29 #include <sys/wait.h> 30 #include <sys/un.h> 31 32 #include <net/if.h> 33 #include <net/if_tun.h> 34 #include <netinet/in.h> 35 #include <netinet/ip.h> 36 #include <netinet/tcp.h> 37 #include <arpa/inet.h> 38 39 #include <ctype.h> 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <netdb.h> 43 #include <paths.h> 44 #include <pwd.h> 45 #include <libgen.h> 46 #include <limits.h> 47 #include <poll.h> 48 #include <signal.h> 49 #include <stdarg.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 #include "xmalloc.h" 56 #include "misc.h" 57 #include "log.h" 58 #include "ssh.h" 59 #include "sshbuf.h" 60 #include "ssherr.h" 61 62 /* remove newline at end of string */ 63 char * 64 chop(char *s) 65 { 66 char *t = s; 67 while (*t) { 68 if (*t == '\n' || *t == '\r') { 69 *t = '\0'; 70 return s; 71 } 72 t++; 73 } 74 return s; 75 76 } 77 78 /* remove whitespace from end of string */ 79 void 80 rtrim(char *s) 81 { 82 size_t i; 83 84 if ((i = strlen(s)) == 0) 85 return; 86 for (i--; i > 0; i--) { 87 if (isspace((unsigned char)s[i])) 88 s[i] = '\0'; 89 } 90 } 91 92 /* set/unset filedescriptor to non-blocking */ 93 int 94 set_nonblock(int fd) 95 { 96 int val; 97 98 val = fcntl(fd, F_GETFL); 99 if (val == -1) { 100 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 101 return (-1); 102 } 103 if (val & O_NONBLOCK) { 104 debug3("fd %d is O_NONBLOCK", fd); 105 return (0); 106 } 107 debug2("fd %d setting O_NONBLOCK", fd); 108 val |= O_NONBLOCK; 109 if (fcntl(fd, F_SETFL, val) == -1) { 110 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 111 strerror(errno)); 112 return (-1); 113 } 114 return (0); 115 } 116 117 int 118 unset_nonblock(int fd) 119 { 120 int val; 121 122 val = fcntl(fd, F_GETFL); 123 if (val == -1) { 124 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 125 return (-1); 126 } 127 if (!(val & O_NONBLOCK)) { 128 debug3("fd %d is not O_NONBLOCK", fd); 129 return (0); 130 } 131 debug("fd %d clearing O_NONBLOCK", fd); 132 val &= ~O_NONBLOCK; 133 if (fcntl(fd, F_SETFL, val) == -1) { 134 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 135 fd, strerror(errno)); 136 return (-1); 137 } 138 return (0); 139 } 140 141 const char * 142 ssh_gai_strerror(int gaierr) 143 { 144 if (gaierr == EAI_SYSTEM && errno != 0) 145 return strerror(errno); 146 return gai_strerror(gaierr); 147 } 148 149 /* disable nagle on socket */ 150 void 151 set_nodelay(int fd) 152 { 153 int opt; 154 socklen_t optlen; 155 156 optlen = sizeof opt; 157 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 158 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 159 return; 160 } 161 if (opt == 1) { 162 debug2("fd %d is TCP_NODELAY", fd); 163 return; 164 } 165 opt = 1; 166 debug2("fd %d setting TCP_NODELAY", fd); 167 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 168 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 169 } 170 171 /* Allow local port reuse in TIME_WAIT */ 172 int 173 set_reuseaddr(int fd) 174 { 175 int on = 1; 176 177 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 178 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 179 return -1; 180 } 181 return 0; 182 } 183 184 /* Get/set routing domain */ 185 char * 186 get_rdomain(int fd) 187 { 188 #ifdef SO_RTABLE 189 int rtable; 190 char *ret; 191 socklen_t len = sizeof(rtable); 192 193 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 194 error("Failed to get routing domain for fd %d: %s", 195 fd, strerror(errno)); 196 return NULL; 197 } 198 xasprintf(&ret, "%d", rtable); 199 return ret; 200 #else 201 return NULL; 202 #endif 203 } 204 205 int 206 set_rdomain(int fd, const char *name) 207 { 208 #ifdef SO_RTABLE 209 int rtable; 210 const char *errstr; 211 212 if (name == NULL) 213 return 0; /* default table */ 214 215 rtable = (int)strtonum(name, 0, 255, &errstr); 216 if (errstr != NULL) { 217 /* Shouldn't happen */ 218 error("Invalid routing domain \"%s\": %s", name, errstr); 219 return -1; 220 } 221 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 222 &rtable, sizeof(rtable)) == -1) { 223 error("Failed to set routing domain %d on fd %d: %s", 224 rtable, fd, strerror(errno)); 225 return -1; 226 } 227 return 0; 228 #else 229 return -1; 230 #endif 231 } 232 233 int 234 get_sock_af(int fd) 235 { 236 struct sockaddr_storage to; 237 socklen_t tolen = sizeof(to); 238 239 memset(&to, 0, sizeof(to)); 240 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 241 return -1; 242 return to.ss_family; 243 } 244 245 void 246 set_sock_tos(int fd, int tos) 247 { 248 int af; 249 250 switch ((af = get_sock_af(fd))) { 251 case -1: 252 /* assume not a socket */ 253 break; 254 case AF_INET: 255 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 256 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 257 &tos, sizeof(tos)) == -1) { 258 error("setsockopt socket %d IP_TOS %d: %s", 259 fd, tos, strerror(errno)); 260 } 261 break; 262 case AF_INET6: 263 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 264 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 265 &tos, sizeof(tos)) == -1) { 266 error("setsockopt socket %d IPV6_TCLASS %d: %s", 267 fd, tos, strerror(errno)); 268 } 269 break; 270 default: 271 debug2_f("unsupported socket family %d", af); 272 break; 273 } 274 } 275 276 /* 277 * Wait up to *timeoutp milliseconds for events on fd. Updates 278 * *timeoutp with time remaining. 279 * Returns 0 if fd ready or -1 on timeout or error (see errno). 280 */ 281 static int 282 waitfd(int fd, int *timeoutp, short events) 283 { 284 struct pollfd pfd; 285 struct timeval t_start; 286 int oerrno, r; 287 288 pfd.fd = fd; 289 pfd.events = events; 290 for (; *timeoutp >= 0;) { 291 monotime_tv(&t_start); 292 r = poll(&pfd, 1, *timeoutp); 293 oerrno = errno; 294 ms_subtract_diff(&t_start, timeoutp); 295 errno = oerrno; 296 if (r > 0) 297 return 0; 298 else if (r == -1 && errno != EAGAIN && errno != EINTR) 299 return -1; 300 else if (r == 0) 301 break; 302 } 303 /* timeout */ 304 errno = ETIMEDOUT; 305 return -1; 306 } 307 308 /* 309 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 310 * *timeoutp with time remaining. 311 * Returns 0 if fd ready or -1 on timeout or error (see errno). 312 */ 313 int 314 waitrfd(int fd, int *timeoutp) { 315 return waitfd(fd, timeoutp, POLLIN); 316 } 317 318 /* 319 * Attempt a non-blocking connect(2) to the specified address, waiting up to 320 * *timeoutp milliseconds for the connection to complete. If the timeout is 321 * <=0, then wait indefinitely. 322 * 323 * Returns 0 on success or -1 on failure. 324 */ 325 int 326 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 327 socklen_t addrlen, int *timeoutp) 328 { 329 int optval = 0; 330 socklen_t optlen = sizeof(optval); 331 332 /* No timeout: just do a blocking connect() */ 333 if (timeoutp == NULL || *timeoutp <= 0) 334 return connect(sockfd, serv_addr, addrlen); 335 336 set_nonblock(sockfd); 337 for (;;) { 338 if (connect(sockfd, serv_addr, addrlen) == 0) { 339 /* Succeeded already? */ 340 unset_nonblock(sockfd); 341 return 0; 342 } else if (errno == EINTR) 343 continue; 344 else if (errno != EINPROGRESS) 345 return -1; 346 break; 347 } 348 349 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) 350 return -1; 351 352 /* Completed or failed */ 353 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 354 debug("getsockopt: %s", strerror(errno)); 355 return -1; 356 } 357 if (optval != 0) { 358 errno = optval; 359 return -1; 360 } 361 unset_nonblock(sockfd); 362 return 0; 363 } 364 365 /* Characters considered whitespace in strsep calls. */ 366 #define WHITESPACE " \t\r\n" 367 #define QUOTE "\"" 368 369 /* return next token in configuration line */ 370 static char * 371 strdelim_internal(char **s, int split_equals) 372 { 373 char *old; 374 int wspace = 0; 375 376 if (*s == NULL) 377 return NULL; 378 379 old = *s; 380 381 *s = strpbrk(*s, 382 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 383 if (*s == NULL) 384 return (old); 385 386 if (*s[0] == '\"') { 387 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 388 /* Find matching quote */ 389 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 390 return (NULL); /* no matching quote */ 391 } else { 392 *s[0] = '\0'; 393 *s += strspn(*s + 1, WHITESPACE) + 1; 394 return (old); 395 } 396 } 397 398 /* Allow only one '=' to be skipped */ 399 if (split_equals && *s[0] == '=') 400 wspace = 1; 401 *s[0] = '\0'; 402 403 /* Skip any extra whitespace after first token */ 404 *s += strspn(*s + 1, WHITESPACE) + 1; 405 if (split_equals && *s[0] == '=' && !wspace) 406 *s += strspn(*s + 1, WHITESPACE) + 1; 407 408 return (old); 409 } 410 411 /* 412 * Return next token in configuration line; splts on whitespace or a 413 * single '=' character. 414 */ 415 char * 416 strdelim(char **s) 417 { 418 return strdelim_internal(s, 1); 419 } 420 421 /* 422 * Return next token in configuration line; splts on whitespace only. 423 */ 424 char * 425 strdelimw(char **s) 426 { 427 return strdelim_internal(s, 0); 428 } 429 430 struct passwd * 431 pwcopy(struct passwd *pw) 432 { 433 struct passwd *copy = xcalloc(1, sizeof(*copy)); 434 435 copy->pw_name = xstrdup(pw->pw_name); 436 copy->pw_passwd = xstrdup(pw->pw_passwd); 437 copy->pw_gecos = xstrdup(pw->pw_gecos); 438 copy->pw_uid = pw->pw_uid; 439 copy->pw_gid = pw->pw_gid; 440 copy->pw_expire = pw->pw_expire; 441 copy->pw_change = pw->pw_change; 442 copy->pw_class = xstrdup(pw->pw_class); 443 copy->pw_dir = xstrdup(pw->pw_dir); 444 copy->pw_shell = xstrdup(pw->pw_shell); 445 return copy; 446 } 447 448 /* 449 * Convert ASCII string to TCP/IP port number. 450 * Port must be >=0 and <=65535. 451 * Return -1 if invalid. 452 */ 453 int 454 a2port(const char *s) 455 { 456 struct servent *se; 457 long long port; 458 const char *errstr; 459 460 port = strtonum(s, 0, 65535, &errstr); 461 if (errstr == NULL) 462 return (int)port; 463 if ((se = getservbyname(s, "tcp")) != NULL) 464 return ntohs(se->s_port); 465 return -1; 466 } 467 468 int 469 a2tun(const char *s, int *remote) 470 { 471 const char *errstr = NULL; 472 char *sp, *ep; 473 int tun; 474 475 if (remote != NULL) { 476 *remote = SSH_TUNID_ANY; 477 sp = xstrdup(s); 478 if ((ep = strchr(sp, ':')) == NULL) { 479 free(sp); 480 return (a2tun(s, NULL)); 481 } 482 ep[0] = '\0'; ep++; 483 *remote = a2tun(ep, NULL); 484 tun = a2tun(sp, NULL); 485 free(sp); 486 return (*remote == SSH_TUNID_ERR ? *remote : tun); 487 } 488 489 if (strcasecmp(s, "any") == 0) 490 return (SSH_TUNID_ANY); 491 492 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 493 if (errstr != NULL) 494 return (SSH_TUNID_ERR); 495 496 return (tun); 497 } 498 499 #define SECONDS 1 500 #define MINUTES (SECONDS * 60) 501 #define HOURS (MINUTES * 60) 502 #define DAYS (HOURS * 24) 503 #define WEEKS (DAYS * 7) 504 505 /* 506 * Convert a time string into seconds; format is 507 * a sequence of: 508 * time[qualifier] 509 * 510 * Valid time qualifiers are: 511 * <none> seconds 512 * s|S seconds 513 * m|M minutes 514 * h|H hours 515 * d|D days 516 * w|W weeks 517 * 518 * Examples: 519 * 90m 90 minutes 520 * 1h30m 90 minutes 521 * 2d 2 days 522 * 1w 1 week 523 * 524 * Return -1 if time string is invalid. 525 */ 526 int 527 convtime(const char *s) 528 { 529 long total, secs, multiplier; 530 const char *p; 531 char *endp; 532 533 errno = 0; 534 total = 0; 535 p = s; 536 537 if (p == NULL || *p == '\0') 538 return -1; 539 540 while (*p) { 541 secs = strtol(p, &endp, 10); 542 if (p == endp || 543 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || 544 secs < 0) 545 return -1; 546 547 multiplier = 1; 548 switch (*endp++) { 549 case '\0': 550 endp--; 551 break; 552 case 's': 553 case 'S': 554 break; 555 case 'm': 556 case 'M': 557 multiplier = MINUTES; 558 break; 559 case 'h': 560 case 'H': 561 multiplier = HOURS; 562 break; 563 case 'd': 564 case 'D': 565 multiplier = DAYS; 566 break; 567 case 'w': 568 case 'W': 569 multiplier = WEEKS; 570 break; 571 default: 572 return -1; 573 } 574 if (secs > INT_MAX / multiplier) 575 return -1; 576 secs *= multiplier; 577 if (total > INT_MAX - secs) 578 return -1; 579 total += secs; 580 if (total < 0) 581 return -1; 582 p = endp; 583 } 584 585 return total; 586 } 587 588 #define TF_BUFS 8 589 #define TF_LEN 21 590 591 const char * 592 fmt_timeframe(time_t t) 593 { 594 char *buf; 595 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 596 static int idx = 0; 597 unsigned int sec, min, hrs, day; 598 unsigned long long week; 599 600 buf = tfbuf[idx++]; 601 if (idx == TF_BUFS) 602 idx = 0; 603 604 week = t; 605 606 sec = week % 60; 607 week /= 60; 608 min = week % 60; 609 week /= 60; 610 hrs = week % 24; 611 week /= 24; 612 day = week % 7; 613 week /= 7; 614 615 if (week > 0) 616 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 617 else if (day > 0) 618 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 619 else 620 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 621 622 return (buf); 623 } 624 625 /* 626 * Returns a standardized host+port identifier string. 627 * Caller must free returned string. 628 */ 629 char * 630 put_host_port(const char *host, u_short port) 631 { 632 char *hoststr; 633 634 if (port == 0 || port == SSH_DEFAULT_PORT) 635 return(xstrdup(host)); 636 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 637 fatal("put_host_port: asprintf: %s", strerror(errno)); 638 debug3("put_host_port: %s", hoststr); 639 return hoststr; 640 } 641 642 /* 643 * Search for next delimiter between hostnames/addresses and ports. 644 * Argument may be modified (for termination). 645 * Returns *cp if parsing succeeds. 646 * *cp is set to the start of the next field, if one was found. 647 * The delimiter char, if present, is stored in delim. 648 * If this is the last field, *cp is set to NULL. 649 */ 650 char * 651 hpdelim2(char **cp, char *delim) 652 { 653 char *s, *old; 654 655 if (cp == NULL || *cp == NULL) 656 return NULL; 657 658 old = s = *cp; 659 if (*s == '[') { 660 if ((s = strchr(s, ']')) == NULL) 661 return NULL; 662 else 663 s++; 664 } else if ((s = strpbrk(s, ":/")) == NULL) 665 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 666 667 switch (*s) { 668 case '\0': 669 *cp = NULL; /* no more fields*/ 670 break; 671 672 case ':': 673 case '/': 674 if (delim != NULL) 675 *delim = *s; 676 *s = '\0'; /* terminate */ 677 *cp = s + 1; 678 break; 679 680 default: 681 return NULL; 682 } 683 684 return old; 685 } 686 687 /* The common case: only accept colon as delimiter. */ 688 char * 689 hpdelim(char **cp) 690 { 691 char *r, delim = '\0'; 692 693 r = hpdelim2(cp, &delim); 694 if (delim == '/') 695 return NULL; 696 return r; 697 } 698 699 char * 700 cleanhostname(char *host) 701 { 702 if (*host == '[' && host[strlen(host) - 1] == ']') { 703 host[strlen(host) - 1] = '\0'; 704 return (host + 1); 705 } else 706 return host; 707 } 708 709 char * 710 colon(char *cp) 711 { 712 int flag = 0; 713 714 if (*cp == ':') /* Leading colon is part of file name. */ 715 return NULL; 716 if (*cp == '[') 717 flag = 1; 718 719 for (; *cp; ++cp) { 720 if (*cp == '@' && *(cp+1) == '[') 721 flag = 1; 722 if (*cp == ']' && *(cp+1) == ':' && flag) 723 return (cp+1); 724 if (*cp == ':' && !flag) 725 return (cp); 726 if (*cp == '/') 727 return NULL; 728 } 729 return NULL; 730 } 731 732 /* 733 * Parse a [user@]host:[path] string. 734 * Caller must free returned user, host and path. 735 * Any of the pointer return arguments may be NULL (useful for syntax checking). 736 * If user was not specified then *userp will be set to NULL. 737 * If host was not specified then *hostp will be set to NULL. 738 * If path was not specified then *pathp will be set to ".". 739 * Returns 0 on success, -1 on failure. 740 */ 741 int 742 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 743 { 744 char *user = NULL, *host = NULL, *path = NULL; 745 char *sdup, *tmp; 746 int ret = -1; 747 748 if (userp != NULL) 749 *userp = NULL; 750 if (hostp != NULL) 751 *hostp = NULL; 752 if (pathp != NULL) 753 *pathp = NULL; 754 755 sdup = xstrdup(s); 756 757 /* Check for remote syntax: [user@]host:[path] */ 758 if ((tmp = colon(sdup)) == NULL) 759 goto out; 760 761 /* Extract optional path */ 762 *tmp++ = '\0'; 763 if (*tmp == '\0') 764 tmp = __UNCONST("."); 765 path = xstrdup(tmp); 766 767 /* Extract optional user and mandatory host */ 768 tmp = strrchr(sdup, '@'); 769 if (tmp != NULL) { 770 *tmp++ = '\0'; 771 host = xstrdup(cleanhostname(tmp)); 772 if (*sdup != '\0') 773 user = xstrdup(sdup); 774 } else { 775 host = xstrdup(cleanhostname(sdup)); 776 user = NULL; 777 } 778 779 /* Success */ 780 if (userp != NULL) { 781 *userp = user; 782 user = NULL; 783 } 784 if (hostp != NULL) { 785 *hostp = host; 786 host = NULL; 787 } 788 if (pathp != NULL) { 789 *pathp = path; 790 path = NULL; 791 } 792 ret = 0; 793 out: 794 free(sdup); 795 free(user); 796 free(host); 797 free(path); 798 return ret; 799 } 800 801 /* 802 * Parse a [user@]host[:port] string. 803 * Caller must free returned user and host. 804 * Any of the pointer return arguments may be NULL (useful for syntax checking). 805 * If user was not specified then *userp will be set to NULL. 806 * If port was not specified then *portp will be -1. 807 * Returns 0 on success, -1 on failure. 808 */ 809 int 810 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 811 { 812 char *sdup, *cp, *tmp; 813 char *user = NULL, *host = NULL; 814 int port = -1, ret = -1; 815 816 if (userp != NULL) 817 *userp = NULL; 818 if (hostp != NULL) 819 *hostp = NULL; 820 if (portp != NULL) 821 *portp = -1; 822 823 if ((sdup = tmp = strdup(s)) == NULL) 824 return -1; 825 /* Extract optional username */ 826 if ((cp = strrchr(tmp, '@')) != NULL) { 827 *cp = '\0'; 828 if (*tmp == '\0') 829 goto out; 830 if ((user = strdup(tmp)) == NULL) 831 goto out; 832 tmp = cp + 1; 833 } 834 /* Extract mandatory hostname */ 835 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 836 goto out; 837 host = xstrdup(cleanhostname(cp)); 838 /* Convert and verify optional port */ 839 if (tmp != NULL && *tmp != '\0') { 840 if ((port = a2port(tmp)) <= 0) 841 goto out; 842 } 843 /* Success */ 844 if (userp != NULL) { 845 *userp = user; 846 user = NULL; 847 } 848 if (hostp != NULL) { 849 *hostp = host; 850 host = NULL; 851 } 852 if (portp != NULL) 853 *portp = port; 854 ret = 0; 855 out: 856 free(sdup); 857 free(user); 858 free(host); 859 return ret; 860 } 861 862 /* 863 * Converts a two-byte hex string to decimal. 864 * Returns the decimal value or -1 for invalid input. 865 */ 866 static int 867 hexchar(const char *s) 868 { 869 unsigned char result[2]; 870 int i; 871 872 for (i = 0; i < 2; i++) { 873 if (s[i] >= '0' && s[i] <= '9') 874 result[i] = (unsigned char)(s[i] - '0'); 875 else if (s[i] >= 'a' && s[i] <= 'f') 876 result[i] = (unsigned char)(s[i] - 'a') + 10; 877 else if (s[i] >= 'A' && s[i] <= 'F') 878 result[i] = (unsigned char)(s[i] - 'A') + 10; 879 else 880 return -1; 881 } 882 return (result[0] << 4) | result[1]; 883 } 884 885 /* 886 * Decode an url-encoded string. 887 * Returns a newly allocated string on success or NULL on failure. 888 */ 889 static char * 890 urldecode(const char *src) 891 { 892 char *ret, *dst; 893 int ch; 894 895 ret = xmalloc(strlen(src) + 1); 896 for (dst = ret; *src != '\0'; src++) { 897 switch (*src) { 898 case '+': 899 *dst++ = ' '; 900 break; 901 case '%': 902 if (!isxdigit((unsigned char)src[1]) || 903 !isxdigit((unsigned char)src[2]) || 904 (ch = hexchar(src + 1)) == -1) { 905 free(ret); 906 return NULL; 907 } 908 *dst++ = ch; 909 src += 2; 910 break; 911 default: 912 *dst++ = *src; 913 break; 914 } 915 } 916 *dst = '\0'; 917 918 return ret; 919 } 920 921 /* 922 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 923 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 924 * Either user or path may be url-encoded (but not host or port). 925 * Caller must free returned user, host and path. 926 * Any of the pointer return arguments may be NULL (useful for syntax checking) 927 * but the scheme must always be specified. 928 * If user was not specified then *userp will be set to NULL. 929 * If port was not specified then *portp will be -1. 930 * If path was not specified then *pathp will be set to NULL. 931 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 932 */ 933 int 934 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 935 int *portp, char **pathp) 936 { 937 char *uridup, *cp, *tmp, ch; 938 char *user = NULL, *host = NULL, *path = NULL; 939 int port = -1, ret = -1; 940 size_t len; 941 942 len = strlen(scheme); 943 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 944 return 1; 945 uri += len + 3; 946 947 if (userp != NULL) 948 *userp = NULL; 949 if (hostp != NULL) 950 *hostp = NULL; 951 if (portp != NULL) 952 *portp = -1; 953 if (pathp != NULL) 954 *pathp = NULL; 955 956 uridup = tmp = xstrdup(uri); 957 958 /* Extract optional ssh-info (username + connection params) */ 959 if ((cp = strchr(tmp, '@')) != NULL) { 960 char *delim; 961 962 *cp = '\0'; 963 /* Extract username and connection params */ 964 if ((delim = strchr(tmp, ';')) != NULL) { 965 /* Just ignore connection params for now */ 966 *delim = '\0'; 967 } 968 if (*tmp == '\0') { 969 /* Empty username */ 970 goto out; 971 } 972 if ((user = urldecode(tmp)) == NULL) 973 goto out; 974 tmp = cp + 1; 975 } 976 977 /* Extract mandatory hostname */ 978 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 979 goto out; 980 host = xstrdup(cleanhostname(cp)); 981 if (!valid_domain(host, 0, NULL)) 982 goto out; 983 984 if (tmp != NULL && *tmp != '\0') { 985 if (ch == ':') { 986 /* Convert and verify port. */ 987 if ((cp = strchr(tmp, '/')) != NULL) 988 *cp = '\0'; 989 if ((port = a2port(tmp)) <= 0) 990 goto out; 991 tmp = cp ? cp + 1 : NULL; 992 } 993 if (tmp != NULL && *tmp != '\0') { 994 /* Extract optional path */ 995 if ((path = urldecode(tmp)) == NULL) 996 goto out; 997 } 998 } 999 1000 /* Success */ 1001 if (userp != NULL) { 1002 *userp = user; 1003 user = NULL; 1004 } 1005 if (hostp != NULL) { 1006 *hostp = host; 1007 host = NULL; 1008 } 1009 if (portp != NULL) 1010 *portp = port; 1011 if (pathp != NULL) { 1012 *pathp = path; 1013 path = NULL; 1014 } 1015 ret = 0; 1016 out: 1017 free(uridup); 1018 free(user); 1019 free(host); 1020 free(path); 1021 return ret; 1022 } 1023 1024 /* function to assist building execv() arguments */ 1025 void 1026 addargs(arglist *args, const char *fmt, ...) 1027 { 1028 va_list ap; 1029 char *cp; 1030 u_int nalloc; 1031 int r; 1032 1033 va_start(ap, fmt); 1034 r = vasprintf(&cp, fmt, ap); 1035 va_end(ap); 1036 if (r == -1) 1037 fatal_f("argument too long"); 1038 1039 nalloc = args->nalloc; 1040 if (args->list == NULL) { 1041 nalloc = 32; 1042 args->num = 0; 1043 } else if (args->num > (256 * 1024)) 1044 fatal_f("too many arguments"); 1045 else if (args->num >= args->nalloc) 1046 fatal_f("arglist corrupt"); 1047 else if (args->num+2 >= nalloc) 1048 nalloc *= 2; 1049 1050 args->list = xrecallocarray(args->list, args->nalloc, 1051 nalloc, sizeof(char *)); 1052 args->nalloc = nalloc; 1053 args->list[args->num++] = cp; 1054 args->list[args->num] = NULL; 1055 } 1056 1057 void 1058 replacearg(arglist *args, u_int which, const char *fmt, ...) 1059 { 1060 va_list ap; 1061 char *cp; 1062 int r; 1063 1064 va_start(ap, fmt); 1065 r = vasprintf(&cp, fmt, ap); 1066 va_end(ap); 1067 if (r == -1) 1068 fatal_f("argument too long"); 1069 if (args->list == NULL || args->num >= args->nalloc) 1070 fatal_f("arglist corrupt"); 1071 1072 if (which >= args->num) 1073 fatal_f("tried to replace invalid arg %d >= %d", 1074 which, args->num); 1075 free(args->list[which]); 1076 args->list[which] = cp; 1077 } 1078 1079 void 1080 freeargs(arglist *args) 1081 { 1082 u_int i; 1083 1084 if (args == NULL) 1085 return; 1086 if (args->list != NULL && args->num < args->nalloc) { 1087 for (i = 0; i < args->num; i++) 1088 free(args->list[i]); 1089 free(args->list); 1090 } 1091 args->nalloc = args->num = 0; 1092 args->list = NULL; 1093 } 1094 1095 /* 1096 * Expands tildes in the file name. Returns data allocated by xmalloc. 1097 * Warning: this calls getpw*. 1098 */ 1099 int 1100 tilde_expand(const char *filename, uid_t uid, char **retp) 1101 { 1102 char *ocopy = NULL, *copy, *s = NULL; 1103 const char *path = NULL, *user = NULL; 1104 struct passwd *pw; 1105 size_t len; 1106 int ret = -1, r, slash; 1107 1108 *retp = NULL; 1109 if (*filename != '~') { 1110 *retp = xstrdup(filename); 1111 return 0; 1112 } 1113 ocopy = copy = xstrdup(filename + 1); 1114 1115 if (*copy == '\0') /* ~ */ 1116 path = NULL; 1117 else if (*copy == '/') { 1118 copy += strspn(copy, "/"); 1119 if (*copy == '\0') 1120 path = NULL; /* ~/ */ 1121 else 1122 path = copy; /* ~/path */ 1123 } else { 1124 user = copy; 1125 if ((path = strchr(copy, '/')) != NULL) { 1126 copy[path - copy] = '\0'; 1127 path++; 1128 path += strspn(path, "/"); 1129 if (*path == '\0') /* ~user/ */ 1130 path = NULL; 1131 /* else ~user/path */ 1132 } 1133 /* else ~user */ 1134 } 1135 if (user != NULL) { 1136 if ((pw = getpwnam(user)) == NULL) { 1137 error_f("No such user %s", user); 1138 goto out; 1139 } 1140 } else if ((pw = getpwuid(uid)) == NULL) { 1141 error_f("No such uid %ld", (long)uid); 1142 goto out; 1143 } 1144 1145 /* Make sure directory has a trailing '/' */ 1146 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1147 1148 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1149 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1150 error_f("xasprintf failed"); 1151 goto out; 1152 } 1153 if (r >= PATH_MAX) { 1154 error_f("Path too long"); 1155 goto out; 1156 } 1157 /* success */ 1158 ret = 0; 1159 *retp = s; 1160 s = NULL; 1161 out: 1162 free(s); 1163 free(ocopy); 1164 return ret; 1165 } 1166 1167 char * 1168 tilde_expand_filename(const char *filename, uid_t uid) 1169 { 1170 char *ret; 1171 1172 if (tilde_expand(filename, uid, &ret) != 0) 1173 cleanup_exit(255); 1174 return ret; 1175 } 1176 1177 /* 1178 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1179 * substitutions. A number of escapes may be specified as 1180 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1181 * by a NULL escape_char. Returns replaced string in memory allocated by 1182 * xmalloc which the caller must free. 1183 */ 1184 static char * 1185 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1186 const char *string, va_list ap) 1187 { 1188 #define EXPAND_MAX_KEYS 16 1189 u_int num_keys = 0, i; 1190 struct { 1191 const char *key; 1192 const char *repl; 1193 } keys[EXPAND_MAX_KEYS]; 1194 struct sshbuf *buf; 1195 int r, missingvar = 0; 1196 char *ret = NULL, *var, *varend, *val; 1197 size_t len; 1198 1199 if ((buf = sshbuf_new()) == NULL) 1200 fatal_f("sshbuf_new failed"); 1201 if (parseerror == NULL) 1202 fatal_f("null parseerror arg"); 1203 *parseerror = 1; 1204 1205 /* Gather keys if we're doing percent expansion. */ 1206 if (percent) { 1207 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1208 keys[num_keys].key = va_arg(ap, char *); 1209 if (keys[num_keys].key == NULL) 1210 break; 1211 keys[num_keys].repl = va_arg(ap, char *); 1212 if (keys[num_keys].repl == NULL) { 1213 fatal_f("NULL replacement for token %s", 1214 keys[num_keys].key); 1215 } 1216 } 1217 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1218 fatal_f("too many keys"); 1219 if (num_keys == 0) 1220 fatal_f("percent expansion without token list"); 1221 } 1222 1223 /* Expand string */ 1224 for (i = 0; *string != '\0'; string++) { 1225 /* Optionally process ${ENVIRONMENT} expansions. */ 1226 if (dollar && string[0] == '$' && string[1] == '{') { 1227 string += 2; /* skip over '${' */ 1228 if ((varend = strchr(string, '}')) == NULL) { 1229 error_f("environment variable '%s' missing " 1230 "closing '}'", string); 1231 goto out; 1232 } 1233 len = varend - string; 1234 if (len == 0) { 1235 error_f("zero-length environment variable"); 1236 goto out; 1237 } 1238 var = xmalloc(len + 1); 1239 (void)strlcpy(var, string, len + 1); 1240 if ((val = getenv(var)) == NULL) { 1241 error_f("env var ${%s} has no value", var); 1242 missingvar = 1; 1243 } else { 1244 debug3_f("expand ${%s} -> '%s'", var, val); 1245 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1246 fatal_fr(r, "sshbuf_put ${}"); 1247 } 1248 free(var); 1249 string += len; 1250 continue; 1251 } 1252 1253 /* 1254 * Process percent expansions if we have a list of TOKENs. 1255 * If we're not doing percent expansion everything just gets 1256 * appended here. 1257 */ 1258 if (*string != '%' || !percent) { 1259 append: 1260 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1261 fatal_fr(r, "sshbuf_put_u8 %%"); 1262 continue; 1263 } 1264 string++; 1265 /* %% case */ 1266 if (*string == '%') 1267 goto append; 1268 if (*string == '\0') { 1269 error_f("invalid format"); 1270 goto out; 1271 } 1272 for (i = 0; i < num_keys; i++) { 1273 if (strchr(keys[i].key, *string) != NULL) { 1274 if ((r = sshbuf_put(buf, keys[i].repl, 1275 strlen(keys[i].repl))) != 0) 1276 fatal_fr(r, "sshbuf_put %%-repl"); 1277 break; 1278 } 1279 } 1280 if (i >= num_keys) { 1281 error_f("unknown key %%%c", *string); 1282 goto out; 1283 } 1284 } 1285 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1286 fatal_f("sshbuf_dup_string failed"); 1287 *parseerror = 0; 1288 out: 1289 sshbuf_free(buf); 1290 return *parseerror ? NULL : ret; 1291 #undef EXPAND_MAX_KEYS 1292 } 1293 1294 /* 1295 * Expand only environment variables. 1296 * Note that although this function is variadic like the other similar 1297 * functions, any such arguments will be unused. 1298 */ 1299 1300 char * 1301 dollar_expand(int *parseerr, const char *string, ...) 1302 { 1303 char *ret; 1304 int err; 1305 va_list ap; 1306 1307 va_start(ap, string); 1308 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1309 va_end(ap); 1310 if (parseerr != NULL) 1311 *parseerr = err; 1312 return ret; 1313 } 1314 1315 /* 1316 * Returns expanded string or NULL if a specified environment variable is 1317 * not defined, or calls fatal if the string is invalid. 1318 */ 1319 char * 1320 percent_expand(const char *string, ...) 1321 { 1322 char *ret; 1323 int err; 1324 va_list ap; 1325 1326 va_start(ap, string); 1327 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1328 va_end(ap); 1329 if (err) 1330 fatal_f("failed"); 1331 return ret; 1332 } 1333 1334 /* 1335 * Returns expanded string or NULL if a specified environment variable is 1336 * not defined, or calls fatal if the string is invalid. 1337 */ 1338 char * 1339 percent_dollar_expand(const char *string, ...) 1340 { 1341 char *ret; 1342 int err; 1343 va_list ap; 1344 1345 va_start(ap, string); 1346 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1347 va_end(ap); 1348 if (err) 1349 fatal_f("failed"); 1350 return ret; 1351 } 1352 1353 int 1354 tun_open(int tun, int mode, char **ifname) 1355 { 1356 struct ifreq ifr; 1357 char name[100]; 1358 int fd = -1, sock; 1359 const char *tunbase = "tun"; 1360 1361 if (ifname != NULL) 1362 *ifname = NULL; 1363 1364 if (mode == SSH_TUNMODE_ETHERNET) 1365 tunbase = "tap"; 1366 1367 /* Open the tunnel device */ 1368 if (tun <= SSH_TUNID_MAX) { 1369 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1370 fd = open(name, O_RDWR); 1371 } else if (tun == SSH_TUNID_ANY) { 1372 for (tun = 100; tun >= 0; tun--) { 1373 snprintf(name, sizeof(name), "/dev/%s%d", 1374 tunbase, tun); 1375 if ((fd = open(name, O_RDWR)) >= 0) 1376 break; 1377 } 1378 } else { 1379 debug_f("invalid tunnel %u", tun); 1380 return -1; 1381 } 1382 1383 if (fd == -1) { 1384 debug_f("%s open: %s", name, strerror(errno)); 1385 return -1; 1386 } 1387 1388 debug_f("%s mode %d fd %d", name, mode, fd); 1389 1390 #ifdef TUNSIFHEAD 1391 /* Turn on tunnel headers */ 1392 int flag = 1; 1393 if (mode != SSH_TUNMODE_ETHERNET && 1394 ioctl(fd, TUNSIFHEAD, &flag) == -1) { 1395 debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd, 1396 strerror(errno)); 1397 close(fd); 1398 return -1; 1399 } 1400 #endif 1401 1402 debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd); 1403 /* Bring interface up if it is not already */ 1404 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1405 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1406 goto failed; 1407 1408 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1409 debug_f("get interface %s flags: %s", ifr.ifr_name, 1410 strerror(errno)); 1411 goto failed; 1412 } 1413 1414 if (!(ifr.ifr_flags & IFF_UP)) { 1415 ifr.ifr_flags |= IFF_UP; 1416 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1417 debug_f("activate interface %s: %s", ifr.ifr_name, 1418 strerror(errno)); 1419 goto failed; 1420 } 1421 } 1422 1423 if (ifname != NULL) 1424 *ifname = xstrdup(ifr.ifr_name); 1425 1426 close(sock); 1427 return fd; 1428 1429 failed: 1430 if (fd >= 0) 1431 close(fd); 1432 if (sock >= 0) 1433 close(sock); 1434 debug("%s: failed to set %s mode %d: %s", __func__, ifr.ifr_name, 1435 mode, strerror(errno)); 1436 return -1; 1437 } 1438 1439 void 1440 sanitise_stdfd(void) 1441 { 1442 int nullfd, dupfd; 1443 1444 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1445 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1446 strerror(errno)); 1447 exit(1); 1448 } 1449 while (++dupfd <= STDERR_FILENO) { 1450 /* Only populate closed fds. */ 1451 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1452 if (dup2(nullfd, dupfd) == -1) { 1453 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1454 exit(1); 1455 } 1456 } 1457 } 1458 if (nullfd > STDERR_FILENO) 1459 close(nullfd); 1460 } 1461 1462 char * 1463 tohex(const void *vp, size_t l) 1464 { 1465 const u_char *p = (const u_char *)vp; 1466 char b[3], *r; 1467 size_t i, hl; 1468 1469 if (l > 65536) 1470 return xstrdup("tohex: length > 65536"); 1471 1472 hl = l * 2 + 1; 1473 r = xcalloc(1, hl); 1474 for (i = 0; i < l; i++) { 1475 snprintf(b, sizeof(b), "%02x", p[i]); 1476 strlcat(r, b, hl); 1477 } 1478 return (r); 1479 } 1480 1481 /* 1482 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1483 * then the separator 'sep' will be prepended before the formatted arguments. 1484 * Extended strings are heap allocated. 1485 */ 1486 void 1487 xextendf(char **sp, const char *sep, const char *fmt, ...) 1488 { 1489 va_list ap; 1490 char *tmp1, *tmp2; 1491 1492 va_start(ap, fmt); 1493 xvasprintf(&tmp1, fmt, ap); 1494 va_end(ap); 1495 1496 if (*sp == NULL || **sp == '\0') { 1497 free(*sp); 1498 *sp = tmp1; 1499 return; 1500 } 1501 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1502 free(tmp1); 1503 free(*sp); 1504 *sp = tmp2; 1505 } 1506 1507 1508 u_int64_t 1509 get_u64(const void *vp) 1510 { 1511 const u_char *p = (const u_char *)vp; 1512 u_int64_t v; 1513 1514 v = (u_int64_t)p[0] << 56; 1515 v |= (u_int64_t)p[1] << 48; 1516 v |= (u_int64_t)p[2] << 40; 1517 v |= (u_int64_t)p[3] << 32; 1518 v |= (u_int64_t)p[4] << 24; 1519 v |= (u_int64_t)p[5] << 16; 1520 v |= (u_int64_t)p[6] << 8; 1521 v |= (u_int64_t)p[7]; 1522 1523 return (v); 1524 } 1525 1526 u_int32_t 1527 get_u32(const void *vp) 1528 { 1529 const u_char *p = (const u_char *)vp; 1530 u_int32_t v; 1531 1532 v = (u_int32_t)p[0] << 24; 1533 v |= (u_int32_t)p[1] << 16; 1534 v |= (u_int32_t)p[2] << 8; 1535 v |= (u_int32_t)p[3]; 1536 1537 return (v); 1538 } 1539 1540 u_int32_t 1541 get_u32_le(const void *vp) 1542 { 1543 const u_char *p = (const u_char *)vp; 1544 u_int32_t v; 1545 1546 v = (u_int32_t)p[0]; 1547 v |= (u_int32_t)p[1] << 8; 1548 v |= (u_int32_t)p[2] << 16; 1549 v |= (u_int32_t)p[3] << 24; 1550 1551 return (v); 1552 } 1553 1554 u_int16_t 1555 get_u16(const void *vp) 1556 { 1557 const u_char *p = (const u_char *)vp; 1558 u_int16_t v; 1559 1560 v = (u_int16_t)p[0] << 8; 1561 v |= (u_int16_t)p[1]; 1562 1563 return (v); 1564 } 1565 1566 void 1567 put_u64(void *vp, u_int64_t v) 1568 { 1569 u_char *p = (u_char *)vp; 1570 1571 p[0] = (u_char)(v >> 56) & 0xff; 1572 p[1] = (u_char)(v >> 48) & 0xff; 1573 p[2] = (u_char)(v >> 40) & 0xff; 1574 p[3] = (u_char)(v >> 32) & 0xff; 1575 p[4] = (u_char)(v >> 24) & 0xff; 1576 p[5] = (u_char)(v >> 16) & 0xff; 1577 p[6] = (u_char)(v >> 8) & 0xff; 1578 p[7] = (u_char)v & 0xff; 1579 } 1580 1581 void 1582 put_u32(void *vp, u_int32_t v) 1583 { 1584 u_char *p = (u_char *)vp; 1585 1586 p[0] = (u_char)(v >> 24) & 0xff; 1587 p[1] = (u_char)(v >> 16) & 0xff; 1588 p[2] = (u_char)(v >> 8) & 0xff; 1589 p[3] = (u_char)v & 0xff; 1590 } 1591 1592 void 1593 put_u32_le(void *vp, u_int32_t v) 1594 { 1595 u_char *p = (u_char *)vp; 1596 1597 p[0] = (u_char)v & 0xff; 1598 p[1] = (u_char)(v >> 8) & 0xff; 1599 p[2] = (u_char)(v >> 16) & 0xff; 1600 p[3] = (u_char)(v >> 24) & 0xff; 1601 } 1602 1603 void 1604 put_u16(void *vp, u_int16_t v) 1605 { 1606 u_char *p = (u_char *)vp; 1607 1608 p[0] = (u_char)(v >> 8) & 0xff; 1609 p[1] = (u_char)v & 0xff; 1610 } 1611 1612 void 1613 ms_subtract_diff(struct timeval *start, int *ms) 1614 { 1615 struct timeval diff, finish; 1616 1617 monotime_tv(&finish); 1618 timersub(&finish, start, &diff); 1619 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1620 } 1621 1622 void 1623 ms_to_timespec(struct timespec *ts, int ms) 1624 { 1625 if (ms < 0) 1626 ms = 0; 1627 ts->tv_sec = ms / 1000; 1628 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1629 } 1630 1631 void 1632 monotime_ts(struct timespec *ts) 1633 { 1634 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1635 fatal("clock_gettime: %s", strerror(errno)); 1636 } 1637 1638 void 1639 monotime_tv(struct timeval *tv) 1640 { 1641 struct timespec ts; 1642 1643 monotime_ts(&ts); 1644 tv->tv_sec = ts.tv_sec; 1645 tv->tv_usec = ts.tv_nsec / 1000; 1646 } 1647 1648 time_t 1649 monotime(void) 1650 { 1651 struct timespec ts; 1652 1653 monotime_ts(&ts); 1654 return (ts.tv_sec); 1655 } 1656 1657 double 1658 monotime_double(void) 1659 { 1660 struct timespec ts; 1661 1662 monotime_ts(&ts); 1663 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1664 } 1665 1666 void 1667 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1668 { 1669 bw->buflen = buflen; 1670 bw->rate = kbps; 1671 bw->thresh = buflen; 1672 bw->lamt = 0; 1673 timerclear(&bw->bwstart); 1674 timerclear(&bw->bwend); 1675 } 1676 1677 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1678 void 1679 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1680 { 1681 u_int64_t waitlen; 1682 struct timespec ts, rm; 1683 1684 bw->lamt += read_len; 1685 if (!timerisset(&bw->bwstart)) { 1686 monotime_tv(&bw->bwstart); 1687 return; 1688 } 1689 if (bw->lamt < bw->thresh) 1690 return; 1691 1692 monotime_tv(&bw->bwend); 1693 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1694 if (!timerisset(&bw->bwend)) 1695 return; 1696 1697 bw->lamt *= 8; 1698 waitlen = (double)1000000L * bw->lamt / bw->rate; 1699 1700 bw->bwstart.tv_sec = waitlen / 1000000L; 1701 bw->bwstart.tv_usec = waitlen % 1000000L; 1702 1703 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1704 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1705 1706 /* Adjust the wait time */ 1707 if (bw->bwend.tv_sec) { 1708 bw->thresh /= 2; 1709 if (bw->thresh < bw->buflen / 4) 1710 bw->thresh = bw->buflen / 4; 1711 } else if (bw->bwend.tv_usec < 10000) { 1712 bw->thresh *= 2; 1713 if (bw->thresh > bw->buflen * 8) 1714 bw->thresh = bw->buflen * 8; 1715 } 1716 1717 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1718 while (nanosleep(&ts, &rm) == -1) { 1719 if (errno != EINTR) 1720 break; 1721 ts = rm; 1722 } 1723 } 1724 1725 bw->lamt = 0; 1726 monotime_tv(&bw->bwstart); 1727 } 1728 1729 /* Make a template filename for mk[sd]temp() */ 1730 void 1731 mktemp_proto(char *s, size_t len) 1732 { 1733 const char *tmpdir; 1734 int r; 1735 1736 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1737 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1738 if (r > 0 && (size_t)r < len) 1739 return; 1740 } 1741 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1742 if (r < 0 || (size_t)r >= len) 1743 fatal_f("template string too short"); 1744 } 1745 1746 static const struct { 1747 const char *name; 1748 int value; 1749 } ipqos[] = { 1750 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1751 { "af11", IPTOS_DSCP_AF11 }, 1752 { "af12", IPTOS_DSCP_AF12 }, 1753 { "af13", IPTOS_DSCP_AF13 }, 1754 { "af21", IPTOS_DSCP_AF21 }, 1755 { "af22", IPTOS_DSCP_AF22 }, 1756 { "af23", IPTOS_DSCP_AF23 }, 1757 { "af31", IPTOS_DSCP_AF31 }, 1758 { "af32", IPTOS_DSCP_AF32 }, 1759 { "af33", IPTOS_DSCP_AF33 }, 1760 { "af41", IPTOS_DSCP_AF41 }, 1761 { "af42", IPTOS_DSCP_AF42 }, 1762 { "af43", IPTOS_DSCP_AF43 }, 1763 { "cs0", IPTOS_DSCP_CS0 }, 1764 { "cs1", IPTOS_DSCP_CS1 }, 1765 { "cs2", IPTOS_DSCP_CS2 }, 1766 { "cs3", IPTOS_DSCP_CS3 }, 1767 { "cs4", IPTOS_DSCP_CS4 }, 1768 { "cs5", IPTOS_DSCP_CS5 }, 1769 { "cs6", IPTOS_DSCP_CS6 }, 1770 { "cs7", IPTOS_DSCP_CS7 }, 1771 { "ef", IPTOS_DSCP_EF }, 1772 #ifdef IPTOS_DSCP_LE 1773 { "le", IPTOS_DSCP_LE }, 1774 #endif 1775 { "lowdelay", IPTOS_LOWDELAY }, 1776 { "throughput", IPTOS_THROUGHPUT }, 1777 { "reliability", IPTOS_RELIABILITY }, 1778 { NULL, -1 } 1779 }; 1780 1781 int 1782 parse_ipqos(const char *cp) 1783 { 1784 u_int i; 1785 char *ep; 1786 long val; 1787 1788 if (cp == NULL) 1789 return -1; 1790 for (i = 0; ipqos[i].name != NULL; i++) { 1791 if (strcasecmp(cp, ipqos[i].name) == 0) 1792 return ipqos[i].value; 1793 } 1794 /* Try parsing as an integer */ 1795 val = strtol(cp, &ep, 0); 1796 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1797 return -1; 1798 return val; 1799 } 1800 1801 const char * 1802 iptos2str(int iptos) 1803 { 1804 int i; 1805 static char iptos_str[sizeof "0xff"]; 1806 1807 for (i = 0; ipqos[i].name != NULL; i++) { 1808 if (ipqos[i].value == iptos) 1809 return ipqos[i].name; 1810 } 1811 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1812 return iptos_str; 1813 } 1814 1815 void 1816 lowercase(char *s) 1817 { 1818 for (; *s; s++) 1819 *s = tolower((u_char)*s); 1820 } 1821 1822 int 1823 unix_listener(const char *path, int backlog, int unlink_first) 1824 { 1825 struct sockaddr_un sunaddr; 1826 int saved_errno, sock; 1827 1828 memset(&sunaddr, 0, sizeof(sunaddr)); 1829 sunaddr.sun_family = AF_UNIX; 1830 if (strlcpy(sunaddr.sun_path, path, 1831 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1832 error_f("path \"%s\" too long for Unix domain socket", path); 1833 errno = ENAMETOOLONG; 1834 return -1; 1835 } 1836 1837 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1838 if (sock == -1) { 1839 saved_errno = errno; 1840 error_f("socket: %.100s", strerror(errno)); 1841 errno = saved_errno; 1842 return -1; 1843 } 1844 if (unlink_first == 1) { 1845 if (unlink(path) != 0 && errno != ENOENT) 1846 error("unlink(%s): %.100s", path, strerror(errno)); 1847 } 1848 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1849 saved_errno = errno; 1850 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1851 close(sock); 1852 errno = saved_errno; 1853 return -1; 1854 } 1855 if (listen(sock, backlog) == -1) { 1856 saved_errno = errno; 1857 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1858 close(sock); 1859 unlink(path); 1860 errno = saved_errno; 1861 return -1; 1862 } 1863 return sock; 1864 } 1865 1866 /* 1867 * Compares two strings that maybe be NULL. Returns non-zero if strings 1868 * are both NULL or are identical, returns zero otherwise. 1869 */ 1870 static int 1871 strcmp_maybe_null(const char *a, const char *b) 1872 { 1873 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1874 return 0; 1875 if (a != NULL && strcmp(a, b) != 0) 1876 return 0; 1877 return 1; 1878 } 1879 1880 /* 1881 * Compare two forwards, returning non-zero if they are identical or 1882 * zero otherwise. 1883 */ 1884 int 1885 forward_equals(const struct Forward *a, const struct Forward *b) 1886 { 1887 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1888 return 0; 1889 if (a->listen_port != b->listen_port) 1890 return 0; 1891 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1892 return 0; 1893 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1894 return 0; 1895 if (a->connect_port != b->connect_port) 1896 return 0; 1897 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1898 return 0; 1899 /* allocated_port and handle are not checked */ 1900 return 1; 1901 } 1902 1903 /* returns 1 if process is already daemonized, 0 otherwise */ 1904 int 1905 daemonized(void) 1906 { 1907 int fd; 1908 1909 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1910 close(fd); 1911 return 0; /* have controlling terminal */ 1912 } 1913 if (getppid() != 1) 1914 return 0; /* parent is not init */ 1915 if (getsid(0) != getpid()) 1916 return 0; /* not session leader */ 1917 debug3("already daemonized"); 1918 return 1; 1919 } 1920 1921 /* 1922 * Splits 's' into an argument vector. Handles quoted string and basic 1923 * escape characters (\\, \", \'). Caller must free the argument vector 1924 * and its members. 1925 */ 1926 int 1927 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1928 { 1929 int r = SSH_ERR_INTERNAL_ERROR; 1930 int argc = 0, quote, i, j; 1931 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1932 1933 *argvp = NULL; 1934 *argcp = 0; 1935 1936 for (i = 0; s[i] != '\0'; i++) { 1937 /* Skip leading whitespace */ 1938 if (s[i] == ' ' || s[i] == '\t') 1939 continue; 1940 if (terminate_on_comment && s[i] == '#') 1941 break; 1942 /* Start of a token */ 1943 quote = 0; 1944 1945 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1946 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1947 argv[argc] = NULL; 1948 1949 /* Copy the token in, removing escapes */ 1950 for (j = 0; s[i] != '\0'; i++) { 1951 if (s[i] == '\\') { 1952 if (s[i + 1] == '\'' || 1953 s[i + 1] == '\"' || 1954 s[i + 1] == '\\' || 1955 (quote == 0 && s[i + 1] == ' ')) { 1956 i++; /* Skip '\' */ 1957 arg[j++] = s[i]; 1958 } else { 1959 /* Unrecognised escape */ 1960 arg[j++] = s[i]; 1961 } 1962 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1963 break; /* done */ 1964 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1965 quote = s[i]; /* quote start */ 1966 else if (quote != 0 && s[i] == quote) 1967 quote = 0; /* quote end */ 1968 else 1969 arg[j++] = s[i]; 1970 } 1971 if (s[i] == '\0') { 1972 if (quote != 0) { 1973 /* Ran out of string looking for close quote */ 1974 r = SSH_ERR_INVALID_FORMAT; 1975 goto out; 1976 } 1977 break; 1978 } 1979 } 1980 /* Success */ 1981 *argcp = argc; 1982 *argvp = argv; 1983 argc = 0; 1984 argv = NULL; 1985 r = 0; 1986 out: 1987 if (argc != 0 && argv != NULL) { 1988 for (i = 0; i < argc; i++) 1989 free(argv[i]); 1990 free(argv); 1991 } 1992 return r; 1993 } 1994 1995 /* 1996 * Reassemble an argument vector into a string, quoting and escaping as 1997 * necessary. Caller must free returned string. 1998 */ 1999 char * 2000 argv_assemble(int argc, char **argv) 2001 { 2002 int i, j, ws, r; 2003 char c, *ret; 2004 struct sshbuf *buf, *arg; 2005 2006 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2007 fatal_f("sshbuf_new failed"); 2008 2009 for (i = 0; i < argc; i++) { 2010 ws = 0; 2011 sshbuf_reset(arg); 2012 for (j = 0; argv[i][j] != '\0'; j++) { 2013 r = 0; 2014 c = argv[i][j]; 2015 switch (c) { 2016 case ' ': 2017 case '\t': 2018 ws = 1; 2019 r = sshbuf_put_u8(arg, c); 2020 break; 2021 case '\\': 2022 case '\'': 2023 case '"': 2024 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2025 break; 2026 /* FALLTHROUGH */ 2027 default: 2028 r = sshbuf_put_u8(arg, c); 2029 break; 2030 } 2031 if (r != 0) 2032 fatal_fr(r, "sshbuf_put_u8"); 2033 } 2034 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2035 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2036 (r = sshbuf_putb(buf, arg)) != 0 || 2037 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2038 fatal_fr(r, "assemble"); 2039 } 2040 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2041 fatal_f("malloc failed"); 2042 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2043 ret[sshbuf_len(buf)] = '\0'; 2044 sshbuf_free(buf); 2045 sshbuf_free(arg); 2046 return ret; 2047 } 2048 2049 char * 2050 argv_next(int *argcp, char ***argvp) 2051 { 2052 char *ret = (*argvp)[0]; 2053 2054 if (*argcp > 0 && ret != NULL) { 2055 (*argcp)--; 2056 (*argvp)++; 2057 } 2058 return ret; 2059 } 2060 2061 void 2062 argv_consume(int *argcp) 2063 { 2064 *argcp = 0; 2065 } 2066 2067 void 2068 argv_free(char **av, int ac) 2069 { 2070 int i; 2071 2072 if (av == NULL) 2073 return; 2074 for (i = 0; i < ac; i++) 2075 free(av[i]); 2076 free(av); 2077 } 2078 2079 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2080 int 2081 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2082 { 2083 int status; 2084 2085 while (waitpid(pid, &status, 0) == -1) { 2086 if (errno != EINTR) { 2087 error("%s waitpid: %s", tag, strerror(errno)); 2088 return -1; 2089 } 2090 } 2091 if (WIFSIGNALED(status)) { 2092 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2093 return -1; 2094 } else if (WEXITSTATUS(status) != 0) { 2095 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2096 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2097 return -1; 2098 } 2099 return 0; 2100 } 2101 2102 /* 2103 * Check a given path for security. This is defined as all components 2104 * of the path to the file must be owned by either the owner of 2105 * of the file or root and no directories must be group or world writable. 2106 * 2107 * XXX Should any specific check be done for sym links ? 2108 * 2109 * Takes a file name, its stat information (preferably from fstat() to 2110 * avoid races), the uid of the expected owner, their home directory and an 2111 * error buffer plus max size as arguments. 2112 * 2113 * Returns 0 on success and -1 on failure 2114 */ 2115 int 2116 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2117 uid_t uid, char *err, size_t errlen) 2118 { 2119 char buf[PATH_MAX], homedir[PATH_MAX]; 2120 char *cp; 2121 int comparehome = 0; 2122 struct stat st; 2123 2124 if (realpath(name, buf) == NULL) { 2125 snprintf(err, errlen, "realpath %s failed: %s", name, 2126 strerror(errno)); 2127 return -1; 2128 } 2129 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2130 comparehome = 1; 2131 2132 if (!S_ISREG(stp->st_mode)) { 2133 snprintf(err, errlen, "%s is not a regular file", buf); 2134 return -1; 2135 } 2136 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2137 (stp->st_mode & 022) != 0) { 2138 snprintf(err, errlen, "bad ownership or modes for file %s", 2139 buf); 2140 return -1; 2141 } 2142 2143 /* for each component of the canonical path, walking upwards */ 2144 for (;;) { 2145 if ((cp = dirname(buf)) == NULL) { 2146 snprintf(err, errlen, "dirname() failed"); 2147 return -1; 2148 } 2149 strlcpy(buf, cp, sizeof(buf)); 2150 2151 if (stat(buf, &st) == -1 || 2152 (st.st_uid != 0 && st.st_uid != uid) || 2153 (st.st_mode & 022) != 0) { 2154 snprintf(err, errlen, 2155 "bad ownership or modes for directory %s", buf); 2156 return -1; 2157 } 2158 2159 /* If are past the homedir then we can stop */ 2160 if (comparehome && strcmp(homedir, buf) == 0) 2161 break; 2162 2163 /* 2164 * dirname should always complete with a "/" path, 2165 * but we can be paranoid and check for "." too 2166 */ 2167 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2168 break; 2169 } 2170 return 0; 2171 } 2172 2173 /* 2174 * Version of safe_path() that accepts an open file descriptor to 2175 * avoid races. 2176 * 2177 * Returns 0 on success and -1 on failure 2178 */ 2179 int 2180 safe_path_fd(int fd, const char *file, struct passwd *pw, 2181 char *err, size_t errlen) 2182 { 2183 struct stat st; 2184 2185 /* check the open file to avoid races */ 2186 if (fstat(fd, &st) == -1) { 2187 snprintf(err, errlen, "cannot stat file %s: %s", 2188 file, strerror(errno)); 2189 return -1; 2190 } 2191 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2192 } 2193 2194 /* 2195 * Sets the value of the given variable in the environment. If the variable 2196 * already exists, its value is overridden. 2197 */ 2198 void 2199 child_set_env(char ***envp, u_int *envsizep, const char *name, 2200 const char *value) 2201 { 2202 char **env; 2203 u_int envsize; 2204 u_int i, namelen; 2205 2206 if (strchr(name, '=') != NULL) { 2207 error("Invalid environment variable \"%.100s\"", name); 2208 return; 2209 } 2210 2211 /* 2212 * Find the slot where the value should be stored. If the variable 2213 * already exists, we reuse the slot; otherwise we append a new slot 2214 * at the end of the array, expanding if necessary. 2215 */ 2216 env = *envp; 2217 namelen = strlen(name); 2218 for (i = 0; env[i]; i++) 2219 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2220 break; 2221 if (env[i]) { 2222 /* Reuse the slot. */ 2223 free(env[i]); 2224 } else { 2225 /* New variable. Expand if necessary. */ 2226 envsize = *envsizep; 2227 if (i >= envsize - 1) { 2228 if (envsize >= 1000) 2229 fatal("child_set_env: too many env vars"); 2230 envsize += 50; 2231 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2232 *envsizep = envsize; 2233 } 2234 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2235 env[i + 1] = NULL; 2236 } 2237 2238 /* Allocate space and format the variable in the appropriate slot. */ 2239 /* XXX xasprintf */ 2240 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2241 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2242 } 2243 2244 /* 2245 * Check and optionally lowercase a domain name, also removes trailing '.' 2246 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2247 */ 2248 int 2249 valid_domain(char *name, int makelower, const char **errstr) 2250 { 2251 size_t i, l = strlen(name); 2252 u_char c, last = '\0'; 2253 static char errbuf[256]; 2254 2255 if (l == 0) { 2256 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2257 goto bad; 2258 } 2259 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2260 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2261 "starts with invalid character", name); 2262 goto bad; 2263 } 2264 for (i = 0; i < l; i++) { 2265 c = tolower((u_char)name[i]); 2266 if (makelower) 2267 name[i] = (char)c; 2268 if (last == '.' && c == '.') { 2269 snprintf(errbuf, sizeof(errbuf), "domain name " 2270 "\"%.100s\" contains consecutive separators", name); 2271 goto bad; 2272 } 2273 if (c != '.' && c != '-' && !isalnum(c) && 2274 c != '_') /* technically invalid, but common */ { 2275 snprintf(errbuf, sizeof(errbuf), "domain name " 2276 "\"%.100s\" contains invalid characters", name); 2277 goto bad; 2278 } 2279 last = c; 2280 } 2281 if (name[l - 1] == '.') 2282 name[l - 1] = '\0'; 2283 if (errstr != NULL) 2284 *errstr = NULL; 2285 return 1; 2286 bad: 2287 if (errstr != NULL) 2288 *errstr = errbuf; 2289 return 0; 2290 } 2291 2292 /* 2293 * Verify that a environment variable name (not including initial '$') is 2294 * valid; consisting of one or more alphanumeric or underscore characters only. 2295 * Returns 1 on valid, 0 otherwise. 2296 */ 2297 int 2298 valid_env_name(const char *name) 2299 { 2300 const char *cp; 2301 2302 if (name[0] == '\0') 2303 return 0; 2304 for (cp = name; *cp != '\0'; cp++) { 2305 if (!isalnum((u_char)*cp) && *cp != '_') 2306 return 0; 2307 } 2308 return 1; 2309 } 2310 2311 const char * 2312 atoi_err(const char *nptr, int *val) 2313 { 2314 const char *errstr = NULL; 2315 long long num; 2316 2317 if (nptr == NULL || *nptr == '\0') 2318 return "missing"; 2319 num = strtonum(nptr, 0, INT_MAX, &errstr); 2320 if (errstr == NULL) 2321 *val = (int)num; 2322 return errstr; 2323 } 2324 2325 int 2326 parse_absolute_time(const char *s, uint64_t *tp) 2327 { 2328 struct tm tm; 2329 time_t tt; 2330 char buf[32]; 2331 const char *fmt, *cp; 2332 size_t l; 2333 int is_utc = 0; 2334 2335 *tp = 0; 2336 2337 l = strlen(s); 2338 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) { 2339 is_utc = 1; 2340 l--; 2341 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) { 2342 is_utc = 1; 2343 l -= 3; 2344 } 2345 /* 2346 * POSIX strptime says "The application shall ensure that there 2347 * is white-space or other non-alphanumeric characters between 2348 * any two conversion specifications" so arrange things this way. 2349 */ 2350 switch (l) { 2351 case 8: /* YYYYMMDD */ 2352 fmt = "%Y-%m-%d"; 2353 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2354 break; 2355 case 12: /* YYYYMMDDHHMM */ 2356 fmt = "%Y-%m-%dT%H:%M"; 2357 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2358 s, s + 4, s + 6, s + 8, s + 10); 2359 break; 2360 case 14: /* YYYYMMDDHHMMSS */ 2361 fmt = "%Y-%m-%dT%H:%M:%S"; 2362 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2363 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2364 break; 2365 default: 2366 return SSH_ERR_INVALID_FORMAT; 2367 } 2368 2369 memset(&tm, 0, sizeof(tm)); 2370 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0') 2371 return SSH_ERR_INVALID_FORMAT; 2372 if (is_utc) { 2373 if ((tt = timegm(&tm)) < 0) 2374 return SSH_ERR_INVALID_FORMAT; 2375 } else { 2376 if ((tt = mktime(&tm)) < 0) 2377 return SSH_ERR_INVALID_FORMAT; 2378 } 2379 /* success */ 2380 *tp = (uint64_t)tt; 2381 return 0; 2382 } 2383 2384 void 2385 format_absolute_time(uint64_t t, char *buf, size_t len) 2386 { 2387 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2388 struct tm tm; 2389 2390 localtime_r(&tt, &tm); 2391 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2392 } 2393 2394 /* check if path is absolute */ 2395 int 2396 path_absolute(const char *path) 2397 { 2398 return (*path == '/') ? 1 : 0; 2399 } 2400 2401 void 2402 skip_space(char **cpp) 2403 { 2404 char *cp; 2405 2406 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2407 ; 2408 *cpp = cp; 2409 } 2410 2411 /* authorized_key-style options parsing helpers */ 2412 2413 /* 2414 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2415 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2416 * if negated option matches. 2417 * If the option or negated option matches, then *optsp is updated to 2418 * point to the first character after the option. 2419 */ 2420 int 2421 opt_flag(const char *opt, int allow_negate, const char **optsp) 2422 { 2423 size_t opt_len = strlen(opt); 2424 const char *opts = *optsp; 2425 int negate = 0; 2426 2427 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2428 opts += 3; 2429 negate = 1; 2430 } 2431 if (strncasecmp(opts, opt, opt_len) == 0) { 2432 *optsp = opts + opt_len; 2433 return negate ? 0 : 1; 2434 } 2435 return -1; 2436 } 2437 2438 char * 2439 opt_dequote(const char **sp, const char **errstrp) 2440 { 2441 const char *s = *sp; 2442 char *ret; 2443 size_t i; 2444 2445 *errstrp = NULL; 2446 if (*s != '"') { 2447 *errstrp = "missing start quote"; 2448 return NULL; 2449 } 2450 s++; 2451 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2452 *errstrp = "memory allocation failed"; 2453 return NULL; 2454 } 2455 for (i = 0; *s != '\0' && *s != '"';) { 2456 if (s[0] == '\\' && s[1] == '"') 2457 s++; 2458 ret[i++] = *s++; 2459 } 2460 if (*s == '\0') { 2461 *errstrp = "missing end quote"; 2462 free(ret); 2463 return NULL; 2464 } 2465 ret[i] = '\0'; 2466 s++; 2467 *sp = s; 2468 return ret; 2469 } 2470 2471 int 2472 opt_match(const char **opts, const char *term) 2473 { 2474 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2475 (*opts)[strlen(term)] == '=') { 2476 *opts += strlen(term) + 1; 2477 return 1; 2478 } 2479 return 0; 2480 } 2481 2482 void 2483 opt_array_append2(const char *file, const int line, const char *directive, 2484 char ***array, int **iarray, u_int *lp, const char *s, int i) 2485 { 2486 2487 if (*lp >= INT_MAX) 2488 fatal("%s line %d: Too many %s entries", file, line, directive); 2489 2490 if (iarray != NULL) { 2491 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2492 sizeof(**iarray)); 2493 (*iarray)[*lp] = i; 2494 } 2495 2496 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2497 (*array)[*lp] = xstrdup(s); 2498 (*lp)++; 2499 } 2500 2501 void 2502 opt_array_append(const char *file, const int line, const char *directive, 2503 char ***array, u_int *lp, const char *s) 2504 { 2505 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2506 } 2507 2508 sshsig_t 2509 ssh_signal(int signum, sshsig_t handler) 2510 { 2511 struct sigaction sa, osa; 2512 2513 /* mask all other signals while in handler */ 2514 memset(&sa, 0, sizeof(sa)); 2515 sa.sa_handler = handler; 2516 sigfillset(&sa.sa_mask); 2517 if (signum != SIGALRM) 2518 sa.sa_flags = SA_RESTART; 2519 if (sigaction(signum, &sa, &osa) == -1) { 2520 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2521 return SIG_ERR; 2522 } 2523 return osa.sa_handler; 2524 } 2525 2526 int 2527 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2528 { 2529 int devnull, ret = 0; 2530 2531 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2532 error_f("open %s: %s", _PATH_DEVNULL, 2533 strerror(errno)); 2534 return -1; 2535 } 2536 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2537 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2538 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2539 error_f("dup2: %s", strerror(errno)); 2540 ret = -1; 2541 } 2542 if (devnull > STDERR_FILENO) 2543 close(devnull); 2544 return ret; 2545 } 2546 2547 /* 2548 * Runs command in a subprocess with a minimal environment. 2549 * Returns pid on success, 0 on failure. 2550 * The child stdout and stderr maybe captured, left attached or sent to 2551 * /dev/null depending on the contents of flags. 2552 * "tag" is prepended to log messages. 2553 * NB. "command" is only used for logging; the actual command executed is 2554 * av[0]. 2555 */ 2556 pid_t 2557 subprocess(const char *tag, const char *command, 2558 int ac, char **av, FILE **child, u_int flags, 2559 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2560 { 2561 FILE *f = NULL; 2562 struct stat st; 2563 int fd, devnull, p[2], i; 2564 pid_t pid; 2565 char *cp, errmsg[512]; 2566 u_int nenv = 0; 2567 char **env = NULL; 2568 2569 /* If dropping privs, then must specify user and restore function */ 2570 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2571 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2572 return 0; 2573 } 2574 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2575 error("%s: no user for current uid", tag); 2576 return 0; 2577 } 2578 if (child != NULL) 2579 *child = NULL; 2580 2581 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2582 tag, command, pw->pw_name, flags); 2583 2584 /* Check consistency */ 2585 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2586 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2587 error_f("inconsistent flags"); 2588 return 0; 2589 } 2590 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2591 error_f("inconsistent flags/output"); 2592 return 0; 2593 } 2594 2595 /* 2596 * If executing an explicit binary, then verify the it exists 2597 * and appears safe-ish to execute 2598 */ 2599 if (!path_absolute(av[0])) { 2600 error("%s path is not absolute", tag); 2601 return 0; 2602 } 2603 if (drop_privs != NULL) 2604 drop_privs(pw); 2605 if (stat(av[0], &st) == -1) { 2606 error("Could not stat %s \"%s\": %s", tag, 2607 av[0], strerror(errno)); 2608 goto restore_return; 2609 } 2610 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2611 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2612 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2613 goto restore_return; 2614 } 2615 /* Prepare to keep the child's stdout if requested */ 2616 if (pipe(p) == -1) { 2617 error("%s: pipe: %s", tag, strerror(errno)); 2618 restore_return: 2619 if (restore_privs != NULL) 2620 restore_privs(); 2621 return 0; 2622 } 2623 if (restore_privs != NULL) 2624 restore_privs(); 2625 2626 switch ((pid = fork())) { 2627 case -1: /* error */ 2628 error("%s: fork: %s", tag, strerror(errno)); 2629 close(p[0]); 2630 close(p[1]); 2631 return 0; 2632 case 0: /* child */ 2633 /* Prepare a minimal environment for the child. */ 2634 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2635 nenv = 5; 2636 env = xcalloc(sizeof(*env), nenv); 2637 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2638 child_set_env(&env, &nenv, "USER", pw->pw_name); 2639 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2640 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2641 if ((cp = getenv("LANG")) != NULL) 2642 child_set_env(&env, &nenv, "LANG", cp); 2643 } 2644 2645 for (i = 1; i < NSIG; i++) 2646 ssh_signal(i, SIG_DFL); 2647 2648 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2649 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2650 strerror(errno)); 2651 _exit(1); 2652 } 2653 if (dup2(devnull, STDIN_FILENO) == -1) { 2654 error("%s: dup2: %s", tag, strerror(errno)); 2655 _exit(1); 2656 } 2657 2658 /* Set up stdout as requested; leave stderr in place for now. */ 2659 fd = -1; 2660 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2661 fd = p[1]; 2662 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2663 fd = devnull; 2664 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2665 error("%s: dup2: %s", tag, strerror(errno)); 2666 _exit(1); 2667 } 2668 closefrom(STDERR_FILENO + 1); 2669 2670 #ifdef __NetBSD__ 2671 #define setresgid(a, b, c) setgid(a) 2672 #define setresuid(a, b, c) setuid(a) 2673 #endif 2674 2675 if (geteuid() == 0 && 2676 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2677 error("%s: initgroups(%s, %u): %s", tag, 2678 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2679 _exit(1); 2680 } 2681 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2682 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2683 strerror(errno)); 2684 _exit(1); 2685 } 2686 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2687 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2688 strerror(errno)); 2689 _exit(1); 2690 } 2691 /* stdin is pointed to /dev/null at this point */ 2692 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2693 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2694 error("%s: dup2: %s", tag, strerror(errno)); 2695 _exit(1); 2696 } 2697 if (env != NULL) 2698 execve(av[0], av, env); 2699 else 2700 execv(av[0], av); 2701 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2702 command, strerror(errno)); 2703 _exit(127); 2704 default: /* parent */ 2705 break; 2706 } 2707 2708 close(p[1]); 2709 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2710 close(p[0]); 2711 else if ((f = fdopen(p[0], "r")) == NULL) { 2712 error("%s: fdopen: %s", tag, strerror(errno)); 2713 close(p[0]); 2714 /* Don't leave zombie child */ 2715 kill(pid, SIGTERM); 2716 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2717 ; 2718 return 0; 2719 } 2720 /* Success */ 2721 debug3_f("%s pid %ld", tag, (long)pid); 2722 if (child != NULL) 2723 *child = f; 2724 return pid; 2725 } 2726 2727 const char * 2728 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2729 { 2730 size_t i, envlen; 2731 2732 envlen = strlen(env); 2733 for (i = 0; i < nenvs; i++) { 2734 if (strncmp(envs[i], env, envlen) == 0 && 2735 envs[i][envlen] == '=') { 2736 return envs[i] + envlen + 1; 2737 } 2738 } 2739 return NULL; 2740 } 2741 2742 const char * 2743 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs) 2744 { 2745 char *name, *cp; 2746 const char *ret; 2747 2748 name = xstrdup(env); 2749 if ((cp = strchr(name, '=')) == NULL) { 2750 free(name); 2751 return NULL; /* not env=val */ 2752 } 2753 *cp = '\0'; 2754 ret = lookup_env_in_list(name, envs, nenvs); 2755 free(name); 2756 return ret; 2757 } 2758 2759 /* 2760 * Helpers for managing poll(2)/ppoll(2) timeouts 2761 * Will remember the earliest deadline and return it for use in poll/ppoll. 2762 */ 2763 2764 /* Initialise a poll/ppoll timeout with an indefinite deadline */ 2765 void 2766 ptimeout_init(struct timespec *pt) 2767 { 2768 /* 2769 * Deliberately invalid for ppoll(2). 2770 * Will be converted to NULL in ptimeout_get_tspec() later. 2771 */ 2772 pt->tv_sec = -1; 2773 pt->tv_nsec = 0; 2774 } 2775 2776 /* Specify a poll/ppoll deadline of at most 'sec' seconds */ 2777 void 2778 ptimeout_deadline_sec(struct timespec *pt, long sec) 2779 { 2780 if (pt->tv_sec == -1 || pt->tv_sec >= sec) { 2781 pt->tv_sec = sec; 2782 pt->tv_nsec = 0; 2783 } 2784 } 2785 2786 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */ 2787 static void 2788 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p) 2789 { 2790 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=)) 2791 *pt = *p; 2792 } 2793 2794 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */ 2795 void 2796 ptimeout_deadline_ms(struct timespec *pt, long ms) 2797 { 2798 struct timespec p; 2799 2800 p.tv_sec = ms / 1000; 2801 p.tv_nsec = (ms % 1000) * 1000000; 2802 ptimeout_deadline_tsp(pt, &p); 2803 } 2804 2805 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */ 2806 void 2807 ptimeout_deadline_monotime(struct timespec *pt, time_t when) 2808 { 2809 struct timespec now, t; 2810 2811 t.tv_sec = when; 2812 t.tv_nsec = 0; 2813 monotime_ts(&now); 2814 2815 if (timespeccmp(&now, &t, >=)) 2816 ptimeout_deadline_sec(pt, 0); 2817 else { 2818 timespecsub(&t, &now, &t); 2819 ptimeout_deadline_tsp(pt, &t); 2820 } 2821 } 2822 2823 /* Get a poll(2) timeout value in milliseconds */ 2824 int 2825 ptimeout_get_ms(struct timespec *pt) 2826 { 2827 if (pt->tv_sec == -1) 2828 return -1; 2829 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000) 2830 return INT_MAX; 2831 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000); 2832 } 2833 2834 /* Get a ppoll(2) timeout value as a timespec pointer */ 2835 struct timespec * 2836 ptimeout_get_tsp(struct timespec *pt) 2837 { 2838 return pt->tv_sec == -1 ? NULL : pt; 2839 } 2840 2841 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */ 2842 int 2843 ptimeout_isset(struct timespec *pt) 2844 { 2845 return pt->tv_sec != -1; 2846 } 2847