1 /* $OpenBSD: misc.c,v 1.132 2018/10/03 06:38:35 djm Exp $ */ 2 /* 3 * Copyright (c) 2000 Markus Friedl. All rights reserved. 4 * Copyright (c) 2005,2006 Damien Miller. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/types.h> 28 #include <sys/ioctl.h> 29 #include <sys/socket.h> 30 #include <sys/stat.h> 31 #include <sys/time.h> 32 #include <sys/wait.h> 33 #include <sys/un.h> 34 35 #include <net/if.h> 36 #include <netinet/in.h> 37 #include <netinet/ip.h> 38 #include <netinet/tcp.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 <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 /* set/unset filedescriptor to non-blocking */ 79 int 80 set_nonblock(int fd) 81 { 82 int val; 83 84 val = fcntl(fd, F_GETFL); 85 if (val < 0) { 86 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 87 return (-1); 88 } 89 if (val & O_NONBLOCK) { 90 debug3("fd %d is O_NONBLOCK", fd); 91 return (0); 92 } 93 debug2("fd %d setting O_NONBLOCK", fd); 94 val |= O_NONBLOCK; 95 if (fcntl(fd, F_SETFL, val) == -1) { 96 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 97 strerror(errno)); 98 return (-1); 99 } 100 return (0); 101 } 102 103 int 104 unset_nonblock(int fd) 105 { 106 int val; 107 108 val = fcntl(fd, F_GETFL); 109 if (val < 0) { 110 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 111 return (-1); 112 } 113 if (!(val & O_NONBLOCK)) { 114 debug3("fd %d is not O_NONBLOCK", fd); 115 return (0); 116 } 117 debug("fd %d clearing O_NONBLOCK", fd); 118 val &= ~O_NONBLOCK; 119 if (fcntl(fd, F_SETFL, val) == -1) { 120 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 121 fd, strerror(errno)); 122 return (-1); 123 } 124 return (0); 125 } 126 127 const char * 128 ssh_gai_strerror(int gaierr) 129 { 130 if (gaierr == EAI_SYSTEM && errno != 0) 131 return strerror(errno); 132 return gai_strerror(gaierr); 133 } 134 135 /* disable nagle on socket */ 136 void 137 set_nodelay(int fd) 138 { 139 int opt; 140 socklen_t optlen; 141 142 optlen = sizeof opt; 143 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 144 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 145 return; 146 } 147 if (opt == 1) { 148 debug2("fd %d is TCP_NODELAY", fd); 149 return; 150 } 151 opt = 1; 152 debug2("fd %d setting TCP_NODELAY", fd); 153 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 154 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 155 } 156 157 /* Allow local port reuse in TIME_WAIT */ 158 int 159 set_reuseaddr(int fd) 160 { 161 int on = 1; 162 163 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 164 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 165 return -1; 166 } 167 return 0; 168 } 169 170 /* Get/set routing domain */ 171 char * 172 get_rdomain(int fd) 173 { 174 int rtable; 175 char *ret; 176 socklen_t len = sizeof(rtable); 177 178 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 179 error("Failed to get routing domain for fd %d: %s", 180 fd, strerror(errno)); 181 return NULL; 182 } 183 xasprintf(&ret, "%d", rtable); 184 return ret; 185 } 186 187 int 188 set_rdomain(int fd, const char *name) 189 { 190 int rtable; 191 const char *errstr; 192 193 if (name == NULL) 194 return 0; /* default table */ 195 196 rtable = (int)strtonum(name, 0, 255, &errstr); 197 if (errstr != NULL) { 198 /* Shouldn't happen */ 199 error("Invalid routing domain \"%s\": %s", name, errstr); 200 return -1; 201 } 202 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 203 &rtable, sizeof(rtable)) == -1) { 204 error("Failed to set routing domain %d on fd %d: %s", 205 rtable, fd, strerror(errno)); 206 return -1; 207 } 208 return 0; 209 } 210 211 /* Characters considered whitespace in strsep calls. */ 212 #define WHITESPACE " \t\r\n" 213 #define QUOTE "\"" 214 215 /* return next token in configuration line */ 216 static char * 217 strdelim_internal(char **s, int split_equals) 218 { 219 char *old; 220 int wspace = 0; 221 222 if (*s == NULL) 223 return NULL; 224 225 old = *s; 226 227 *s = strpbrk(*s, 228 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 229 if (*s == NULL) 230 return (old); 231 232 if (*s[0] == '\"') { 233 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 234 /* Find matching quote */ 235 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 236 return (NULL); /* no matching quote */ 237 } else { 238 *s[0] = '\0'; 239 *s += strspn(*s + 1, WHITESPACE) + 1; 240 return (old); 241 } 242 } 243 244 /* Allow only one '=' to be skipped */ 245 if (split_equals && *s[0] == '=') 246 wspace = 1; 247 *s[0] = '\0'; 248 249 /* Skip any extra whitespace after first token */ 250 *s += strspn(*s + 1, WHITESPACE) + 1; 251 if (split_equals && *s[0] == '=' && !wspace) 252 *s += strspn(*s + 1, WHITESPACE) + 1; 253 254 return (old); 255 } 256 257 /* 258 * Return next token in configuration line; splts on whitespace or a 259 * single '=' character. 260 */ 261 char * 262 strdelim(char **s) 263 { 264 return strdelim_internal(s, 1); 265 } 266 267 /* 268 * Return next token in configuration line; splts on whitespace only. 269 */ 270 char * 271 strdelimw(char **s) 272 { 273 return strdelim_internal(s, 0); 274 } 275 276 struct passwd * 277 pwcopy(struct passwd *pw) 278 { 279 struct passwd *copy = xcalloc(1, sizeof(*copy)); 280 281 copy->pw_name = xstrdup(pw->pw_name); 282 copy->pw_passwd = xstrdup(pw->pw_passwd); 283 copy->pw_gecos = xstrdup(pw->pw_gecos); 284 copy->pw_uid = pw->pw_uid; 285 copy->pw_gid = pw->pw_gid; 286 copy->pw_expire = pw->pw_expire; 287 copy->pw_change = pw->pw_change; 288 copy->pw_class = xstrdup(pw->pw_class); 289 copy->pw_dir = xstrdup(pw->pw_dir); 290 copy->pw_shell = xstrdup(pw->pw_shell); 291 return copy; 292 } 293 294 /* 295 * Convert ASCII string to TCP/IP port number. 296 * Port must be >=0 and <=65535. 297 * Return -1 if invalid. 298 */ 299 int 300 a2port(const char *s) 301 { 302 long long port; 303 const char *errstr; 304 305 port = strtonum(s, 0, 65535, &errstr); 306 if (errstr != NULL) 307 return -1; 308 return (int)port; 309 } 310 311 int 312 a2tun(const char *s, int *remote) 313 { 314 const char *errstr = NULL; 315 char *sp, *ep; 316 int tun; 317 318 if (remote != NULL) { 319 *remote = SSH_TUNID_ANY; 320 sp = xstrdup(s); 321 if ((ep = strchr(sp, ':')) == NULL) { 322 free(sp); 323 return (a2tun(s, NULL)); 324 } 325 ep[0] = '\0'; ep++; 326 *remote = a2tun(ep, NULL); 327 tun = a2tun(sp, NULL); 328 free(sp); 329 return (*remote == SSH_TUNID_ERR ? *remote : tun); 330 } 331 332 if (strcasecmp(s, "any") == 0) 333 return (SSH_TUNID_ANY); 334 335 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 336 if (errstr != NULL) 337 return (SSH_TUNID_ERR); 338 339 return (tun); 340 } 341 342 #define SECONDS 1 343 #define MINUTES (SECONDS * 60) 344 #define HOURS (MINUTES * 60) 345 #define DAYS (HOURS * 24) 346 #define WEEKS (DAYS * 7) 347 348 /* 349 * Convert a time string into seconds; format is 350 * a sequence of: 351 * time[qualifier] 352 * 353 * Valid time qualifiers are: 354 * <none> seconds 355 * s|S seconds 356 * m|M minutes 357 * h|H hours 358 * d|D days 359 * w|W weeks 360 * 361 * Examples: 362 * 90m 90 minutes 363 * 1h30m 90 minutes 364 * 2d 2 days 365 * 1w 1 week 366 * 367 * Return -1 if time string is invalid. 368 */ 369 long 370 convtime(const char *s) 371 { 372 long total, secs, multiplier = 1; 373 const char *p; 374 char *endp; 375 376 errno = 0; 377 total = 0; 378 p = s; 379 380 if (p == NULL || *p == '\0') 381 return -1; 382 383 while (*p) { 384 secs = strtol(p, &endp, 10); 385 if (p == endp || 386 (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) || 387 secs < 0) 388 return -1; 389 390 switch (*endp++) { 391 case '\0': 392 endp--; 393 break; 394 case 's': 395 case 'S': 396 break; 397 case 'm': 398 case 'M': 399 multiplier = MINUTES; 400 break; 401 case 'h': 402 case 'H': 403 multiplier = HOURS; 404 break; 405 case 'd': 406 case 'D': 407 multiplier = DAYS; 408 break; 409 case 'w': 410 case 'W': 411 multiplier = WEEKS; 412 break; 413 default: 414 return -1; 415 } 416 if (secs >= LONG_MAX / multiplier) 417 return -1; 418 secs *= multiplier; 419 if (total >= LONG_MAX - secs) 420 return -1; 421 total += secs; 422 if (total < 0) 423 return -1; 424 p = endp; 425 } 426 427 return total; 428 } 429 430 /* 431 * Returns a standardized host+port identifier string. 432 * Caller must free returned string. 433 */ 434 char * 435 put_host_port(const char *host, u_short port) 436 { 437 char *hoststr; 438 439 if (port == 0 || port == SSH_DEFAULT_PORT) 440 return(xstrdup(host)); 441 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0) 442 fatal("put_host_port: asprintf: %s", strerror(errno)); 443 debug3("put_host_port: %s", hoststr); 444 return hoststr; 445 } 446 447 /* 448 * Search for next delimiter between hostnames/addresses and ports. 449 * Argument may be modified (for termination). 450 * Returns *cp if parsing succeeds. 451 * *cp is set to the start of the next field, if one was found. 452 * The delimiter char, if present, is stored in delim. 453 * If this is the last field, *cp is set to NULL. 454 */ 455 static char * 456 hpdelim2(char **cp, char *delim) 457 { 458 char *s, *old; 459 460 if (cp == NULL || *cp == NULL) 461 return NULL; 462 463 old = s = *cp; 464 if (*s == '[') { 465 if ((s = strchr(s, ']')) == NULL) 466 return NULL; 467 else 468 s++; 469 } else if ((s = strpbrk(s, ":/")) == NULL) 470 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 471 472 switch (*s) { 473 case '\0': 474 *cp = NULL; /* no more fields*/ 475 break; 476 477 case ':': 478 case '/': 479 if (delim != NULL) 480 *delim = *s; 481 *s = '\0'; /* terminate */ 482 *cp = s + 1; 483 break; 484 485 default: 486 return NULL; 487 } 488 489 return old; 490 } 491 492 char * 493 hpdelim(char **cp) 494 { 495 return hpdelim2(cp, NULL); 496 } 497 498 char * 499 cleanhostname(char *host) 500 { 501 if (*host == '[' && host[strlen(host) - 1] == ']') { 502 host[strlen(host) - 1] = '\0'; 503 return (host + 1); 504 } else 505 return host; 506 } 507 508 char * 509 colon(char *cp) 510 { 511 int flag = 0; 512 513 if (*cp == ':') /* Leading colon is part of file name. */ 514 return NULL; 515 if (*cp == '[') 516 flag = 1; 517 518 for (; *cp; ++cp) { 519 if (*cp == '@' && *(cp+1) == '[') 520 flag = 1; 521 if (*cp == ']' && *(cp+1) == ':' && flag) 522 return (cp+1); 523 if (*cp == ':' && !flag) 524 return (cp); 525 if (*cp == '/') 526 return NULL; 527 } 528 return NULL; 529 } 530 531 /* 532 * Parse a [user@]host:[path] string. 533 * Caller must free returned user, host and path. 534 * Any of the pointer return arguments may be NULL (useful for syntax checking). 535 * If user was not specified then *userp will be set to NULL. 536 * If host was not specified then *hostp will be set to NULL. 537 * If path was not specified then *pathp will be set to ".". 538 * Returns 0 on success, -1 on failure. 539 */ 540 int 541 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 542 { 543 char *user = NULL, *host = NULL, *path = NULL; 544 char *sdup, *tmp; 545 int ret = -1; 546 547 if (userp != NULL) 548 *userp = NULL; 549 if (hostp != NULL) 550 *hostp = NULL; 551 if (pathp != NULL) 552 *pathp = NULL; 553 554 sdup = xstrdup(s); 555 556 /* Check for remote syntax: [user@]host:[path] */ 557 if ((tmp = colon(sdup)) == NULL) 558 goto out; 559 560 /* Extract optional path */ 561 *tmp++ = '\0'; 562 if (*tmp == '\0') 563 tmp = "."; 564 path = xstrdup(tmp); 565 566 /* Extract optional user and mandatory host */ 567 tmp = strrchr(sdup, '@'); 568 if (tmp != NULL) { 569 *tmp++ = '\0'; 570 host = xstrdup(cleanhostname(tmp)); 571 if (*sdup != '\0') 572 user = xstrdup(sdup); 573 } else { 574 host = xstrdup(cleanhostname(sdup)); 575 user = NULL; 576 } 577 578 /* Success */ 579 if (userp != NULL) { 580 *userp = user; 581 user = NULL; 582 } 583 if (hostp != NULL) { 584 *hostp = host; 585 host = NULL; 586 } 587 if (pathp != NULL) { 588 *pathp = path; 589 path = NULL; 590 } 591 ret = 0; 592 out: 593 free(sdup); 594 free(user); 595 free(host); 596 free(path); 597 return ret; 598 } 599 600 /* 601 * Parse a [user@]host[:port] string. 602 * Caller must free returned user and host. 603 * Any of the pointer return arguments may be NULL (useful for syntax checking). 604 * If user was not specified then *userp will be set to NULL. 605 * If port was not specified then *portp will be -1. 606 * Returns 0 on success, -1 on failure. 607 */ 608 int 609 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 610 { 611 char *sdup, *cp, *tmp; 612 char *user = NULL, *host = NULL; 613 int port = -1, ret = -1; 614 615 if (userp != NULL) 616 *userp = NULL; 617 if (hostp != NULL) 618 *hostp = NULL; 619 if (portp != NULL) 620 *portp = -1; 621 622 if ((sdup = tmp = strdup(s)) == NULL) 623 return -1; 624 /* Extract optional username */ 625 if ((cp = strrchr(tmp, '@')) != NULL) { 626 *cp = '\0'; 627 if (*tmp == '\0') 628 goto out; 629 if ((user = strdup(tmp)) == NULL) 630 goto out; 631 tmp = cp + 1; 632 } 633 /* Extract mandatory hostname */ 634 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 635 goto out; 636 host = xstrdup(cleanhostname(cp)); 637 /* Convert and verify optional port */ 638 if (tmp != NULL && *tmp != '\0') { 639 if ((port = a2port(tmp)) <= 0) 640 goto out; 641 } 642 /* Success */ 643 if (userp != NULL) { 644 *userp = user; 645 user = NULL; 646 } 647 if (hostp != NULL) { 648 *hostp = host; 649 host = NULL; 650 } 651 if (portp != NULL) 652 *portp = port; 653 ret = 0; 654 out: 655 free(sdup); 656 free(user); 657 free(host); 658 return ret; 659 } 660 661 /* 662 * Converts a two-byte hex string to decimal. 663 * Returns the decimal value or -1 for invalid input. 664 */ 665 static int 666 hexchar(const char *s) 667 { 668 unsigned char result[2]; 669 int i; 670 671 for (i = 0; i < 2; i++) { 672 if (s[i] >= '0' && s[i] <= '9') 673 result[i] = (unsigned char)(s[i] - '0'); 674 else if (s[i] >= 'a' && s[i] <= 'f') 675 result[i] = (unsigned char)(s[i] - 'a') + 10; 676 else if (s[i] >= 'A' && s[i] <= 'F') 677 result[i] = (unsigned char)(s[i] - 'A') + 10; 678 else 679 return -1; 680 } 681 return (result[0] << 4) | result[1]; 682 } 683 684 /* 685 * Decode an url-encoded string. 686 * Returns a newly allocated string on success or NULL on failure. 687 */ 688 static char * 689 urldecode(const char *src) 690 { 691 char *ret, *dst; 692 int ch; 693 694 ret = xmalloc(strlen(src) + 1); 695 for (dst = ret; *src != '\0'; src++) { 696 switch (*src) { 697 case '+': 698 *dst++ = ' '; 699 break; 700 case '%': 701 if (!isxdigit((unsigned char)src[1]) || 702 !isxdigit((unsigned char)src[2]) || 703 (ch = hexchar(src + 1)) == -1) { 704 free(ret); 705 return NULL; 706 } 707 *dst++ = ch; 708 src += 2; 709 break; 710 default: 711 *dst++ = *src; 712 break; 713 } 714 } 715 *dst = '\0'; 716 717 return ret; 718 } 719 720 /* 721 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 722 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 723 * Either user or path may be url-encoded (but not host or port). 724 * Caller must free returned user, host and path. 725 * Any of the pointer return arguments may be NULL (useful for syntax checking) 726 * but the scheme must always be specified. 727 * If user was not specified then *userp will be set to NULL. 728 * If port was not specified then *portp will be -1. 729 * If path was not specified then *pathp will be set to NULL. 730 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 731 */ 732 int 733 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 734 int *portp, char **pathp) 735 { 736 char *uridup, *cp, *tmp, ch; 737 char *user = NULL, *host = NULL, *path = NULL; 738 int port = -1, ret = -1; 739 size_t len; 740 741 len = strlen(scheme); 742 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 743 return 1; 744 uri += len + 3; 745 746 if (userp != NULL) 747 *userp = NULL; 748 if (hostp != NULL) 749 *hostp = NULL; 750 if (portp != NULL) 751 *portp = -1; 752 if (pathp != NULL) 753 *pathp = NULL; 754 755 uridup = tmp = xstrdup(uri); 756 757 /* Extract optional ssh-info (username + connection params) */ 758 if ((cp = strchr(tmp, '@')) != NULL) { 759 char *delim; 760 761 *cp = '\0'; 762 /* Extract username and connection params */ 763 if ((delim = strchr(tmp, ';')) != NULL) { 764 /* Just ignore connection params for now */ 765 *delim = '\0'; 766 } 767 if (*tmp == '\0') { 768 /* Empty username */ 769 goto out; 770 } 771 if ((user = urldecode(tmp)) == NULL) 772 goto out; 773 tmp = cp + 1; 774 } 775 776 /* Extract mandatory hostname */ 777 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 778 goto out; 779 host = xstrdup(cleanhostname(cp)); 780 if (!valid_domain(host, 0, NULL)) 781 goto out; 782 783 if (tmp != NULL && *tmp != '\0') { 784 if (ch == ':') { 785 /* Convert and verify port. */ 786 if ((cp = strchr(tmp, '/')) != NULL) 787 *cp = '\0'; 788 if ((port = a2port(tmp)) <= 0) 789 goto out; 790 tmp = cp ? cp + 1 : NULL; 791 } 792 if (tmp != NULL && *tmp != '\0') { 793 /* Extract optional path */ 794 if ((path = urldecode(tmp)) == NULL) 795 goto out; 796 } 797 } 798 799 /* Success */ 800 if (userp != NULL) { 801 *userp = user; 802 user = NULL; 803 } 804 if (hostp != NULL) { 805 *hostp = host; 806 host = NULL; 807 } 808 if (portp != NULL) 809 *portp = port; 810 if (pathp != NULL) { 811 *pathp = path; 812 path = NULL; 813 } 814 ret = 0; 815 out: 816 free(uridup); 817 free(user); 818 free(host); 819 free(path); 820 return ret; 821 } 822 823 /* function to assist building execv() arguments */ 824 void 825 addargs(arglist *args, char *fmt, ...) 826 { 827 va_list ap; 828 char *cp; 829 u_int nalloc; 830 int r; 831 832 va_start(ap, fmt); 833 r = vasprintf(&cp, fmt, ap); 834 va_end(ap); 835 if (r == -1) 836 fatal("addargs: argument too long"); 837 838 nalloc = args->nalloc; 839 if (args->list == NULL) { 840 nalloc = 32; 841 args->num = 0; 842 } else if (args->num+2 >= nalloc) 843 nalloc *= 2; 844 845 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 846 args->nalloc = nalloc; 847 args->list[args->num++] = cp; 848 args->list[args->num] = NULL; 849 } 850 851 void 852 replacearg(arglist *args, u_int which, char *fmt, ...) 853 { 854 va_list ap; 855 char *cp; 856 int r; 857 858 va_start(ap, fmt); 859 r = vasprintf(&cp, fmt, ap); 860 va_end(ap); 861 if (r == -1) 862 fatal("replacearg: argument too long"); 863 864 if (which >= args->num) 865 fatal("replacearg: tried to replace invalid arg %d >= %d", 866 which, args->num); 867 free(args->list[which]); 868 args->list[which] = cp; 869 } 870 871 void 872 freeargs(arglist *args) 873 { 874 u_int i; 875 876 if (args->list != NULL) { 877 for (i = 0; i < args->num; i++) 878 free(args->list[i]); 879 free(args->list); 880 args->nalloc = args->num = 0; 881 args->list = NULL; 882 } 883 } 884 885 /* 886 * Expands tildes in the file name. Returns data allocated by xmalloc. 887 * Warning: this calls getpw*. 888 */ 889 char * 890 tilde_expand_filename(const char *filename, uid_t uid) 891 { 892 const char *path, *sep; 893 char user[128], *ret; 894 struct passwd *pw; 895 u_int len, slash; 896 897 if (*filename != '~') 898 return (xstrdup(filename)); 899 filename++; 900 901 path = strchr(filename, '/'); 902 if (path != NULL && path > filename) { /* ~user/path */ 903 slash = path - filename; 904 if (slash > sizeof(user) - 1) 905 fatal("tilde_expand_filename: ~username too long"); 906 memcpy(user, filename, slash); 907 user[slash] = '\0'; 908 if ((pw = getpwnam(user)) == NULL) 909 fatal("tilde_expand_filename: No such user %s", user); 910 } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ 911 fatal("tilde_expand_filename: No such uid %ld", (long)uid); 912 913 /* Make sure directory has a trailing '/' */ 914 len = strlen(pw->pw_dir); 915 if (len == 0 || pw->pw_dir[len - 1] != '/') 916 sep = "/"; 917 else 918 sep = ""; 919 920 /* Skip leading '/' from specified path */ 921 if (path != NULL) 922 filename = path + 1; 923 924 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) 925 fatal("tilde_expand_filename: Path too long"); 926 927 return (ret); 928 } 929 930 /* 931 * Expand a string with a set of %[char] escapes. A number of escapes may be 932 * specified as (char *escape_chars, char *replacement) pairs. The list must 933 * be terminated by a NULL escape_char. Returns replaced string in memory 934 * allocated by xmalloc. 935 */ 936 char * 937 percent_expand(const char *string, ...) 938 { 939 #define EXPAND_MAX_KEYS 16 940 u_int num_keys, i, j; 941 struct { 942 const char *key; 943 const char *repl; 944 } keys[EXPAND_MAX_KEYS]; 945 char buf[4096]; 946 va_list ap; 947 948 /* Gather keys */ 949 va_start(ap, string); 950 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 951 keys[num_keys].key = va_arg(ap, char *); 952 if (keys[num_keys].key == NULL) 953 break; 954 keys[num_keys].repl = va_arg(ap, char *); 955 if (keys[num_keys].repl == NULL) 956 fatal("%s: NULL replacement", __func__); 957 } 958 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 959 fatal("%s: too many keys", __func__); 960 va_end(ap); 961 962 /* Expand string */ 963 *buf = '\0'; 964 for (i = 0; *string != '\0'; string++) { 965 if (*string != '%') { 966 append: 967 buf[i++] = *string; 968 if (i >= sizeof(buf)) 969 fatal("%s: string too long", __func__); 970 buf[i] = '\0'; 971 continue; 972 } 973 string++; 974 /* %% case */ 975 if (*string == '%') 976 goto append; 977 if (*string == '\0') 978 fatal("%s: invalid format", __func__); 979 for (j = 0; j < num_keys; j++) { 980 if (strchr(keys[j].key, *string) != NULL) { 981 i = strlcat(buf, keys[j].repl, sizeof(buf)); 982 if (i >= sizeof(buf)) 983 fatal("%s: string too long", __func__); 984 break; 985 } 986 } 987 if (j >= num_keys) 988 fatal("%s: unknown key %%%c", __func__, *string); 989 } 990 return (xstrdup(buf)); 991 #undef EXPAND_MAX_KEYS 992 } 993 994 int 995 tun_open(int tun, int mode, char **ifname) 996 { 997 struct ifreq ifr; 998 char name[100]; 999 int fd = -1, sock; 1000 const char *tunbase = "tun"; 1001 1002 if (ifname != NULL) 1003 *ifname = NULL; 1004 1005 if (mode == SSH_TUNMODE_ETHERNET) 1006 tunbase = "tap"; 1007 1008 /* Open the tunnel device */ 1009 if (tun <= SSH_TUNID_MAX) { 1010 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1011 fd = open(name, O_RDWR); 1012 } else if (tun == SSH_TUNID_ANY) { 1013 for (tun = 100; tun >= 0; tun--) { 1014 snprintf(name, sizeof(name), "/dev/%s%d", 1015 tunbase, tun); 1016 if ((fd = open(name, O_RDWR)) >= 0) 1017 break; 1018 } 1019 } else { 1020 debug("%s: invalid tunnel %u", __func__, tun); 1021 return -1; 1022 } 1023 1024 if (fd < 0) { 1025 debug("%s: %s open: %s", __func__, name, strerror(errno)); 1026 return -1; 1027 } 1028 1029 debug("%s: %s mode %d fd %d", __func__, name, mode, fd); 1030 1031 /* Bring interface up if it is not already */ 1032 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1033 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1034 goto failed; 1035 1036 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1037 debug("%s: get interface %s flags: %s", __func__, 1038 ifr.ifr_name, strerror(errno)); 1039 goto failed; 1040 } 1041 1042 if (!(ifr.ifr_flags & IFF_UP)) { 1043 ifr.ifr_flags |= IFF_UP; 1044 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1045 debug("%s: activate interface %s: %s", __func__, 1046 ifr.ifr_name, strerror(errno)); 1047 goto failed; 1048 } 1049 } 1050 1051 if (ifname != NULL) 1052 *ifname = xstrdup(ifr.ifr_name); 1053 1054 close(sock); 1055 return fd; 1056 1057 failed: 1058 if (fd >= 0) 1059 close(fd); 1060 if (sock >= 0) 1061 close(sock); 1062 return -1; 1063 } 1064 1065 void 1066 sanitise_stdfd(void) 1067 { 1068 int nullfd, dupfd; 1069 1070 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1071 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1072 strerror(errno)); 1073 exit(1); 1074 } 1075 while (++dupfd <= STDERR_FILENO) { 1076 /* Only populate closed fds. */ 1077 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1078 if (dup2(nullfd, dupfd) == -1) { 1079 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1080 exit(1); 1081 } 1082 } 1083 } 1084 if (nullfd > STDERR_FILENO) 1085 close(nullfd); 1086 } 1087 1088 char * 1089 tohex(const void *vp, size_t l) 1090 { 1091 const u_char *p = (const u_char *)vp; 1092 char b[3], *r; 1093 size_t i, hl; 1094 1095 if (l > 65536) 1096 return xstrdup("tohex: length > 65536"); 1097 1098 hl = l * 2 + 1; 1099 r = xcalloc(1, hl); 1100 for (i = 0; i < l; i++) { 1101 snprintf(b, sizeof(b), "%02x", p[i]); 1102 strlcat(r, b, hl); 1103 } 1104 return (r); 1105 } 1106 1107 u_int64_t 1108 get_u64(const void *vp) 1109 { 1110 const u_char *p = (const u_char *)vp; 1111 u_int64_t v; 1112 1113 v = (u_int64_t)p[0] << 56; 1114 v |= (u_int64_t)p[1] << 48; 1115 v |= (u_int64_t)p[2] << 40; 1116 v |= (u_int64_t)p[3] << 32; 1117 v |= (u_int64_t)p[4] << 24; 1118 v |= (u_int64_t)p[5] << 16; 1119 v |= (u_int64_t)p[6] << 8; 1120 v |= (u_int64_t)p[7]; 1121 1122 return (v); 1123 } 1124 1125 u_int32_t 1126 get_u32(const void *vp) 1127 { 1128 const u_char *p = (const u_char *)vp; 1129 u_int32_t v; 1130 1131 v = (u_int32_t)p[0] << 24; 1132 v |= (u_int32_t)p[1] << 16; 1133 v |= (u_int32_t)p[2] << 8; 1134 v |= (u_int32_t)p[3]; 1135 1136 return (v); 1137 } 1138 1139 u_int32_t 1140 get_u32_le(const void *vp) 1141 { 1142 const u_char *p = (const u_char *)vp; 1143 u_int32_t v; 1144 1145 v = (u_int32_t)p[0]; 1146 v |= (u_int32_t)p[1] << 8; 1147 v |= (u_int32_t)p[2] << 16; 1148 v |= (u_int32_t)p[3] << 24; 1149 1150 return (v); 1151 } 1152 1153 u_int16_t 1154 get_u16(const void *vp) 1155 { 1156 const u_char *p = (const u_char *)vp; 1157 u_int16_t v; 1158 1159 v = (u_int16_t)p[0] << 8; 1160 v |= (u_int16_t)p[1]; 1161 1162 return (v); 1163 } 1164 1165 void 1166 put_u64(void *vp, u_int64_t v) 1167 { 1168 u_char *p = (u_char *)vp; 1169 1170 p[0] = (u_char)(v >> 56) & 0xff; 1171 p[1] = (u_char)(v >> 48) & 0xff; 1172 p[2] = (u_char)(v >> 40) & 0xff; 1173 p[3] = (u_char)(v >> 32) & 0xff; 1174 p[4] = (u_char)(v >> 24) & 0xff; 1175 p[5] = (u_char)(v >> 16) & 0xff; 1176 p[6] = (u_char)(v >> 8) & 0xff; 1177 p[7] = (u_char)v & 0xff; 1178 } 1179 1180 void 1181 put_u32(void *vp, u_int32_t v) 1182 { 1183 u_char *p = (u_char *)vp; 1184 1185 p[0] = (u_char)(v >> 24) & 0xff; 1186 p[1] = (u_char)(v >> 16) & 0xff; 1187 p[2] = (u_char)(v >> 8) & 0xff; 1188 p[3] = (u_char)v & 0xff; 1189 } 1190 1191 void 1192 put_u32_le(void *vp, u_int32_t v) 1193 { 1194 u_char *p = (u_char *)vp; 1195 1196 p[0] = (u_char)v & 0xff; 1197 p[1] = (u_char)(v >> 8) & 0xff; 1198 p[2] = (u_char)(v >> 16) & 0xff; 1199 p[3] = (u_char)(v >> 24) & 0xff; 1200 } 1201 1202 void 1203 put_u16(void *vp, u_int16_t v) 1204 { 1205 u_char *p = (u_char *)vp; 1206 1207 p[0] = (u_char)(v >> 8) & 0xff; 1208 p[1] = (u_char)v & 0xff; 1209 } 1210 1211 void 1212 ms_subtract_diff(struct timeval *start, int *ms) 1213 { 1214 struct timeval diff, finish; 1215 1216 monotime_tv(&finish); 1217 timersub(&finish, start, &diff); 1218 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1219 } 1220 1221 void 1222 ms_to_timeval(struct timeval *tv, int ms) 1223 { 1224 if (ms < 0) 1225 ms = 0; 1226 tv->tv_sec = ms / 1000; 1227 tv->tv_usec = (ms % 1000) * 1000; 1228 } 1229 1230 void 1231 monotime_ts(struct timespec *ts) 1232 { 1233 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1234 fatal("clock_gettime: %s", strerror(errno)); 1235 } 1236 1237 void 1238 monotime_tv(struct timeval *tv) 1239 { 1240 struct timespec ts; 1241 1242 monotime_ts(&ts); 1243 tv->tv_sec = ts.tv_sec; 1244 tv->tv_usec = ts.tv_nsec / 1000; 1245 } 1246 1247 time_t 1248 monotime(void) 1249 { 1250 struct timespec ts; 1251 1252 monotime_ts(&ts); 1253 return (ts.tv_sec); 1254 } 1255 1256 double 1257 monotime_double(void) 1258 { 1259 struct timespec ts; 1260 1261 monotime_ts(&ts); 1262 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1263 } 1264 1265 void 1266 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1267 { 1268 bw->buflen = buflen; 1269 bw->rate = kbps; 1270 bw->thresh = bw->rate; 1271 bw->lamt = 0; 1272 timerclear(&bw->bwstart); 1273 timerclear(&bw->bwend); 1274 } 1275 1276 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1277 void 1278 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1279 { 1280 u_int64_t waitlen; 1281 struct timespec ts, rm; 1282 1283 if (!timerisset(&bw->bwstart)) { 1284 monotime_tv(&bw->bwstart); 1285 return; 1286 } 1287 1288 bw->lamt += read_len; 1289 if (bw->lamt < bw->thresh) 1290 return; 1291 1292 monotime_tv(&bw->bwend); 1293 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1294 if (!timerisset(&bw->bwend)) 1295 return; 1296 1297 bw->lamt *= 8; 1298 waitlen = (double)1000000L * bw->lamt / bw->rate; 1299 1300 bw->bwstart.tv_sec = waitlen / 1000000L; 1301 bw->bwstart.tv_usec = waitlen % 1000000L; 1302 1303 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1304 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1305 1306 /* Adjust the wait time */ 1307 if (bw->bwend.tv_sec) { 1308 bw->thresh /= 2; 1309 if (bw->thresh < bw->buflen / 4) 1310 bw->thresh = bw->buflen / 4; 1311 } else if (bw->bwend.tv_usec < 10000) { 1312 bw->thresh *= 2; 1313 if (bw->thresh > bw->buflen * 8) 1314 bw->thresh = bw->buflen * 8; 1315 } 1316 1317 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1318 while (nanosleep(&ts, &rm) == -1) { 1319 if (errno != EINTR) 1320 break; 1321 ts = rm; 1322 } 1323 } 1324 1325 bw->lamt = 0; 1326 monotime_tv(&bw->bwstart); 1327 } 1328 1329 /* Make a template filename for mk[sd]temp() */ 1330 void 1331 mktemp_proto(char *s, size_t len) 1332 { 1333 const char *tmpdir; 1334 int r; 1335 1336 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1337 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1338 if (r > 0 && (size_t)r < len) 1339 return; 1340 } 1341 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1342 if (r < 0 || (size_t)r >= len) 1343 fatal("%s: template string too short", __func__); 1344 } 1345 1346 static const struct { 1347 const char *name; 1348 int value; 1349 } ipqos[] = { 1350 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1351 { "af11", IPTOS_DSCP_AF11 }, 1352 { "af12", IPTOS_DSCP_AF12 }, 1353 { "af13", IPTOS_DSCP_AF13 }, 1354 { "af21", IPTOS_DSCP_AF21 }, 1355 { "af22", IPTOS_DSCP_AF22 }, 1356 { "af23", IPTOS_DSCP_AF23 }, 1357 { "af31", IPTOS_DSCP_AF31 }, 1358 { "af32", IPTOS_DSCP_AF32 }, 1359 { "af33", IPTOS_DSCP_AF33 }, 1360 { "af41", IPTOS_DSCP_AF41 }, 1361 { "af42", IPTOS_DSCP_AF42 }, 1362 { "af43", IPTOS_DSCP_AF43 }, 1363 { "cs0", IPTOS_DSCP_CS0 }, 1364 { "cs1", IPTOS_DSCP_CS1 }, 1365 { "cs2", IPTOS_DSCP_CS2 }, 1366 { "cs3", IPTOS_DSCP_CS3 }, 1367 { "cs4", IPTOS_DSCP_CS4 }, 1368 { "cs5", IPTOS_DSCP_CS5 }, 1369 { "cs6", IPTOS_DSCP_CS6 }, 1370 { "cs7", IPTOS_DSCP_CS7 }, 1371 { "ef", IPTOS_DSCP_EF }, 1372 { "lowdelay", IPTOS_LOWDELAY }, 1373 { "throughput", IPTOS_THROUGHPUT }, 1374 { "reliability", IPTOS_RELIABILITY }, 1375 { NULL, -1 } 1376 }; 1377 1378 int 1379 parse_ipqos(const char *cp) 1380 { 1381 u_int i; 1382 char *ep; 1383 long val; 1384 1385 if (cp == NULL) 1386 return -1; 1387 for (i = 0; ipqos[i].name != NULL; i++) { 1388 if (strcasecmp(cp, ipqos[i].name) == 0) 1389 return ipqos[i].value; 1390 } 1391 /* Try parsing as an integer */ 1392 val = strtol(cp, &ep, 0); 1393 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1394 return -1; 1395 return val; 1396 } 1397 1398 const char * 1399 iptos2str(int iptos) 1400 { 1401 int i; 1402 static char iptos_str[sizeof "0xff"]; 1403 1404 for (i = 0; ipqos[i].name != NULL; i++) { 1405 if (ipqos[i].value == iptos) 1406 return ipqos[i].name; 1407 } 1408 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1409 return iptos_str; 1410 } 1411 1412 void 1413 lowercase(char *s) 1414 { 1415 for (; *s; s++) 1416 *s = tolower((u_char)*s); 1417 } 1418 1419 int 1420 unix_listener(const char *path, int backlog, int unlink_first) 1421 { 1422 struct sockaddr_un sunaddr; 1423 int saved_errno, sock; 1424 1425 memset(&sunaddr, 0, sizeof(sunaddr)); 1426 sunaddr.sun_family = AF_UNIX; 1427 if (strlcpy(sunaddr.sun_path, path, 1428 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1429 error("%s: path \"%s\" too long for Unix domain socket", 1430 __func__, path); 1431 errno = ENAMETOOLONG; 1432 return -1; 1433 } 1434 1435 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1436 if (sock < 0) { 1437 saved_errno = errno; 1438 error("%s: socket: %.100s", __func__, strerror(errno)); 1439 errno = saved_errno; 1440 return -1; 1441 } 1442 if (unlink_first == 1) { 1443 if (unlink(path) != 0 && errno != ENOENT) 1444 error("unlink(%s): %.100s", path, strerror(errno)); 1445 } 1446 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) { 1447 saved_errno = errno; 1448 error("%s: cannot bind to path %s: %s", 1449 __func__, path, strerror(errno)); 1450 close(sock); 1451 errno = saved_errno; 1452 return -1; 1453 } 1454 if (listen(sock, backlog) < 0) { 1455 saved_errno = errno; 1456 error("%s: cannot listen on path %s: %s", 1457 __func__, path, strerror(errno)); 1458 close(sock); 1459 unlink(path); 1460 errno = saved_errno; 1461 return -1; 1462 } 1463 return sock; 1464 } 1465 1466 /* 1467 * Compares two strings that maybe be NULL. Returns non-zero if strings 1468 * are both NULL or are identical, returns zero otherwise. 1469 */ 1470 static int 1471 strcmp_maybe_null(const char *a, const char *b) 1472 { 1473 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1474 return 0; 1475 if (a != NULL && strcmp(a, b) != 0) 1476 return 0; 1477 return 1; 1478 } 1479 1480 /* 1481 * Compare two forwards, returning non-zero if they are identical or 1482 * zero otherwise. 1483 */ 1484 int 1485 forward_equals(const struct Forward *a, const struct Forward *b) 1486 { 1487 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1488 return 0; 1489 if (a->listen_port != b->listen_port) 1490 return 0; 1491 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1492 return 0; 1493 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1494 return 0; 1495 if (a->connect_port != b->connect_port) 1496 return 0; 1497 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1498 return 0; 1499 /* allocated_port and handle are not checked */ 1500 return 1; 1501 } 1502 1503 /* returns 1 if process is already daemonized, 0 otherwise */ 1504 int 1505 daemonized(void) 1506 { 1507 int fd; 1508 1509 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1510 close(fd); 1511 return 0; /* have controlling terminal */ 1512 } 1513 if (getppid() != 1) 1514 return 0; /* parent is not init */ 1515 if (getsid(0) != getpid()) 1516 return 0; /* not session leader */ 1517 debug3("already daemonized"); 1518 return 1; 1519 } 1520 1521 1522 /* 1523 * Splits 's' into an argument vector. Handles quoted string and basic 1524 * escape characters (\\, \", \'). Caller must free the argument vector 1525 * and its members. 1526 */ 1527 int 1528 argv_split(const char *s, int *argcp, char ***argvp) 1529 { 1530 int r = SSH_ERR_INTERNAL_ERROR; 1531 int argc = 0, quote, i, j; 1532 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1533 1534 *argvp = NULL; 1535 *argcp = 0; 1536 1537 for (i = 0; s[i] != '\0'; i++) { 1538 /* Skip leading whitespace */ 1539 if (s[i] == ' ' || s[i] == '\t') 1540 continue; 1541 1542 /* Start of a token */ 1543 quote = 0; 1544 if (s[i] == '\\' && 1545 (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\')) 1546 i++; 1547 else if (s[i] == '\'' || s[i] == '"') 1548 quote = s[i++]; 1549 1550 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1551 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1552 argv[argc] = NULL; 1553 1554 /* Copy the token in, removing escapes */ 1555 for (j = 0; s[i] != '\0'; i++) { 1556 if (s[i] == '\\') { 1557 if (s[i + 1] == '\'' || 1558 s[i + 1] == '\"' || 1559 s[i + 1] == '\\') { 1560 i++; /* Skip '\' */ 1561 arg[j++] = s[i]; 1562 } else { 1563 /* Unrecognised escape */ 1564 arg[j++] = s[i]; 1565 } 1566 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1567 break; /* done */ 1568 else if (quote != 0 && s[i] == quote) 1569 break; /* done */ 1570 else 1571 arg[j++] = s[i]; 1572 } 1573 if (s[i] == '\0') { 1574 if (quote != 0) { 1575 /* Ran out of string looking for close quote */ 1576 r = SSH_ERR_INVALID_FORMAT; 1577 goto out; 1578 } 1579 break; 1580 } 1581 } 1582 /* Success */ 1583 *argcp = argc; 1584 *argvp = argv; 1585 argc = 0; 1586 argv = NULL; 1587 r = 0; 1588 out: 1589 if (argc != 0 && argv != NULL) { 1590 for (i = 0; i < argc; i++) 1591 free(argv[i]); 1592 free(argv); 1593 } 1594 return r; 1595 } 1596 1597 /* 1598 * Reassemble an argument vector into a string, quoting and escaping as 1599 * necessary. Caller must free returned string. 1600 */ 1601 char * 1602 argv_assemble(int argc, char **argv) 1603 { 1604 int i, j, ws, r; 1605 char c, *ret; 1606 struct sshbuf *buf, *arg; 1607 1608 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1609 fatal("%s: sshbuf_new failed", __func__); 1610 1611 for (i = 0; i < argc; i++) { 1612 ws = 0; 1613 sshbuf_reset(arg); 1614 for (j = 0; argv[i][j] != '\0'; j++) { 1615 r = 0; 1616 c = argv[i][j]; 1617 switch (c) { 1618 case ' ': 1619 case '\t': 1620 ws = 1; 1621 r = sshbuf_put_u8(arg, c); 1622 break; 1623 case '\\': 1624 case '\'': 1625 case '"': 1626 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 1627 break; 1628 /* FALLTHROUGH */ 1629 default: 1630 r = sshbuf_put_u8(arg, c); 1631 break; 1632 } 1633 if (r != 0) 1634 fatal("%s: sshbuf_put_u8: %s", 1635 __func__, ssh_err(r)); 1636 } 1637 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 1638 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 1639 (r = sshbuf_putb(buf, arg)) != 0 || 1640 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 1641 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1642 } 1643 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 1644 fatal("%s: malloc failed", __func__); 1645 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 1646 ret[sshbuf_len(buf)] = '\0'; 1647 sshbuf_free(buf); 1648 sshbuf_free(arg); 1649 return ret; 1650 } 1651 1652 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 1653 int 1654 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 1655 { 1656 int status; 1657 1658 while (waitpid(pid, &status, 0) == -1) { 1659 if (errno != EINTR) { 1660 error("%s: waitpid: %s", tag, strerror(errno)); 1661 return -1; 1662 } 1663 } 1664 if (WIFSIGNALED(status)) { 1665 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 1666 return -1; 1667 } else if (WEXITSTATUS(status) != 0) { 1668 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 1669 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 1670 return -1; 1671 } 1672 return 0; 1673 } 1674 1675 /* 1676 * Check a given path for security. This is defined as all components 1677 * of the path to the file must be owned by either the owner of 1678 * of the file or root and no directories must be group or world writable. 1679 * 1680 * XXX Should any specific check be done for sym links ? 1681 * 1682 * Takes a file name, its stat information (preferably from fstat() to 1683 * avoid races), the uid of the expected owner, their home directory and an 1684 * error buffer plus max size as arguments. 1685 * 1686 * Returns 0 on success and -1 on failure 1687 */ 1688 int 1689 safe_path(const char *name, struct stat *stp, const char *pw_dir, 1690 uid_t uid, char *err, size_t errlen) 1691 { 1692 char buf[PATH_MAX], homedir[PATH_MAX]; 1693 char *cp; 1694 int comparehome = 0; 1695 struct stat st; 1696 1697 if (realpath(name, buf) == NULL) { 1698 snprintf(err, errlen, "realpath %s failed: %s", name, 1699 strerror(errno)); 1700 return -1; 1701 } 1702 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 1703 comparehome = 1; 1704 1705 if (!S_ISREG(stp->st_mode)) { 1706 snprintf(err, errlen, "%s is not a regular file", buf); 1707 return -1; 1708 } 1709 if ((stp->st_uid != 0 && stp->st_uid != uid) || 1710 (stp->st_mode & 022) != 0) { 1711 snprintf(err, errlen, "bad ownership or modes for file %s", 1712 buf); 1713 return -1; 1714 } 1715 1716 /* for each component of the canonical path, walking upwards */ 1717 for (;;) { 1718 if ((cp = dirname(buf)) == NULL) { 1719 snprintf(err, errlen, "dirname() failed"); 1720 return -1; 1721 } 1722 strlcpy(buf, cp, sizeof(buf)); 1723 1724 if (stat(buf, &st) < 0 || 1725 (st.st_uid != 0 && st.st_uid != uid) || 1726 (st.st_mode & 022) != 0) { 1727 snprintf(err, errlen, 1728 "bad ownership or modes for directory %s", buf); 1729 return -1; 1730 } 1731 1732 /* If are past the homedir then we can stop */ 1733 if (comparehome && strcmp(homedir, buf) == 0) 1734 break; 1735 1736 /* 1737 * dirname should always complete with a "/" path, 1738 * but we can be paranoid and check for "." too 1739 */ 1740 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 1741 break; 1742 } 1743 return 0; 1744 } 1745 1746 /* 1747 * Version of safe_path() that accepts an open file descriptor to 1748 * avoid races. 1749 * 1750 * Returns 0 on success and -1 on failure 1751 */ 1752 int 1753 safe_path_fd(int fd, const char *file, struct passwd *pw, 1754 char *err, size_t errlen) 1755 { 1756 struct stat st; 1757 1758 /* check the open file to avoid races */ 1759 if (fstat(fd, &st) < 0) { 1760 snprintf(err, errlen, "cannot stat file %s: %s", 1761 file, strerror(errno)); 1762 return -1; 1763 } 1764 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 1765 } 1766 1767 /* 1768 * Sets the value of the given variable in the environment. If the variable 1769 * already exists, its value is overridden. 1770 */ 1771 void 1772 child_set_env(char ***envp, u_int *envsizep, const char *name, 1773 const char *value) 1774 { 1775 char **env; 1776 u_int envsize; 1777 u_int i, namelen; 1778 1779 if (strchr(name, '=') != NULL) { 1780 error("Invalid environment variable \"%.100s\"", name); 1781 return; 1782 } 1783 1784 /* 1785 * Find the slot where the value should be stored. If the variable 1786 * already exists, we reuse the slot; otherwise we append a new slot 1787 * at the end of the array, expanding if necessary. 1788 */ 1789 env = *envp; 1790 namelen = strlen(name); 1791 for (i = 0; env[i]; i++) 1792 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 1793 break; 1794 if (env[i]) { 1795 /* Reuse the slot. */ 1796 free(env[i]); 1797 } else { 1798 /* New variable. Expand if necessary. */ 1799 envsize = *envsizep; 1800 if (i >= envsize - 1) { 1801 if (envsize >= 1000) 1802 fatal("child_set_env: too many env vars"); 1803 envsize += 50; 1804 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 1805 *envsizep = envsize; 1806 } 1807 /* Need to set the NULL pointer at end of array beyond the new slot. */ 1808 env[i + 1] = NULL; 1809 } 1810 1811 /* Allocate space and format the variable in the appropriate slot. */ 1812 /* XXX xasprintf */ 1813 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 1814 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 1815 } 1816 1817 /* 1818 * Check and optionally lowercase a domain name, also removes trailing '.' 1819 * Returns 1 on success and 0 on failure, storing an error message in errstr. 1820 */ 1821 int 1822 valid_domain(char *name, int makelower, const char **errstr) 1823 { 1824 size_t i, l = strlen(name); 1825 u_char c, last = '\0'; 1826 static char errbuf[256]; 1827 1828 if (l == 0) { 1829 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 1830 goto bad; 1831 } 1832 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 1833 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 1834 "starts with invalid character", name); 1835 goto bad; 1836 } 1837 for (i = 0; i < l; i++) { 1838 c = tolower((u_char)name[i]); 1839 if (makelower) 1840 name[i] = (char)c; 1841 if (last == '.' && c == '.') { 1842 snprintf(errbuf, sizeof(errbuf), "domain name " 1843 "\"%.100s\" contains consecutive separators", name); 1844 goto bad; 1845 } 1846 if (c != '.' && c != '-' && !isalnum(c) && 1847 c != '_') /* technically invalid, but common */ { 1848 snprintf(errbuf, sizeof(errbuf), "domain name " 1849 "\"%.100s\" contains invalid characters", name); 1850 goto bad; 1851 } 1852 last = c; 1853 } 1854 if (name[l - 1] == '.') 1855 name[l - 1] = '\0'; 1856 if (errstr != NULL) 1857 *errstr = NULL; 1858 return 1; 1859 bad: 1860 if (errstr != NULL) 1861 *errstr = errbuf; 1862 return 0; 1863 } 1864 1865 /* 1866 * Verify that a environment variable name (not including initial '$') is 1867 * valid; consisting of one or more alphanumeric or underscore characters only. 1868 * Returns 1 on valid, 0 otherwise. 1869 */ 1870 int 1871 valid_env_name(const char *name) 1872 { 1873 const char *cp; 1874 1875 if (name[0] == '\0') 1876 return 0; 1877 for (cp = name; *cp != '\0'; cp++) { 1878 if (!isalnum((u_char)*cp) && *cp != '_') 1879 return 0; 1880 } 1881 return 1; 1882 } 1883 1884 const char * 1885 atoi_err(const char *nptr, int *val) 1886 { 1887 const char *errstr = NULL; 1888 long long num; 1889 1890 if (nptr == NULL || *nptr == '\0') 1891 return "missing"; 1892 num = strtonum(nptr, 0, INT_MAX, &errstr); 1893 if (errstr == NULL) 1894 *val = (int)num; 1895 return errstr; 1896 } 1897 1898 int 1899 parse_absolute_time(const char *s, uint64_t *tp) 1900 { 1901 struct tm tm; 1902 time_t tt; 1903 char buf[32], *fmt; 1904 1905 *tp = 0; 1906 1907 /* 1908 * POSIX strptime says "The application shall ensure that there 1909 * is white-space or other non-alphanumeric characters between 1910 * any two conversion specifications" so arrange things this way. 1911 */ 1912 switch (strlen(s)) { 1913 case 8: /* YYYYMMDD */ 1914 fmt = "%Y-%m-%d"; 1915 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 1916 break; 1917 case 12: /* YYYYMMDDHHMM */ 1918 fmt = "%Y-%m-%dT%H:%M"; 1919 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 1920 s, s + 4, s + 6, s + 8, s + 10); 1921 break; 1922 case 14: /* YYYYMMDDHHMMSS */ 1923 fmt = "%Y-%m-%dT%H:%M:%S"; 1924 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 1925 s, s + 4, s + 6, s + 8, s + 10, s + 12); 1926 break; 1927 default: 1928 return SSH_ERR_INVALID_FORMAT; 1929 } 1930 1931 memset(&tm, 0, sizeof(tm)); 1932 if (strptime(buf, fmt, &tm) == NULL) 1933 return SSH_ERR_INVALID_FORMAT; 1934 if ((tt = mktime(&tm)) < 0) 1935 return SSH_ERR_INVALID_FORMAT; 1936 /* success */ 1937 *tp = (uint64_t)tt; 1938 return 0; 1939 } 1940 1941 void 1942 format_absolute_time(uint64_t t, char *buf, size_t len) 1943 { 1944 time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */ 1945 struct tm tm; 1946 1947 localtime_r(&tt, &tm); 1948 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 1949 } 1950