1 /* $OpenBSD: misc.c,v 1.127 2018/03/12 00:52:01 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 "includes.h" 28 29 #include <sys/types.h> 30 #include <sys/ioctl.h> 31 #include <sys/socket.h> 32 #include <sys/stat.h> 33 #include <sys/sysctl.h> 34 #include <sys/time.h> 35 #include <sys/wait.h> 36 #include <sys/un.h> 37 38 #include <limits.h> 39 #ifdef HAVE_LIBGEN_H 40 # include <libgen.h> 41 #endif 42 #include <signal.h> 43 #include <stdarg.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <time.h> 48 #include <unistd.h> 49 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #include <netinet/ip.h> 53 #include <netinet/tcp.h> 54 55 #include <ctype.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <netdb.h> 59 #ifdef HAVE_PATHS_H 60 # include <paths.h> 61 #include <pwd.h> 62 #endif 63 #ifdef SSH_TUN_OPENBSD 64 #include <net/if.h> 65 #endif 66 67 #include "xmalloc.h" 68 #include "misc.h" 69 #include "log.h" 70 #include "ssh.h" 71 #include "sshbuf.h" 72 #include "ssherr.h" 73 #include "uidswap.h" 74 #include "platform.h" 75 76 /* remove newline at end of string */ 77 char * 78 chop(char *s) 79 { 80 char *t = s; 81 while (*t) { 82 if (*t == '\n' || *t == '\r') { 83 *t = '\0'; 84 return s; 85 } 86 t++; 87 } 88 return s; 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 < 0) { 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 < 0) { 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 #if defined(HAVE_SYS_GET_RDOMAIN) 189 return sys_get_rdomain(fd); 190 #elif defined(__OpenBSD__) 191 int rtable; 192 char *ret; 193 socklen_t len = sizeof(rtable); 194 195 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 196 error("Failed to get routing domain for fd %d: %s", 197 fd, strerror(errno)); 198 return NULL; 199 } 200 xasprintf(&ret, "%d", rtable); 201 return ret; 202 #else /* defined(__OpenBSD__) */ 203 return NULL; 204 #endif 205 } 206 207 int 208 set_rdomain(int fd, const char *name) 209 { 210 #if defined(HAVE_SYS_SET_RDOMAIN) 211 return sys_set_rdomain(fd, name); 212 #elif defined(__OpenBSD__) 213 int rtable; 214 const char *errstr; 215 216 if (name == NULL) 217 return 0; /* default table */ 218 219 rtable = (int)strtonum(name, 0, 255, &errstr); 220 if (errstr != NULL) { 221 /* Shouldn't happen */ 222 error("Invalid routing domain \"%s\": %s", name, errstr); 223 return -1; 224 } 225 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 226 &rtable, sizeof(rtable)) == -1) { 227 error("Failed to set routing domain %d on fd %d: %s", 228 rtable, fd, strerror(errno)); 229 return -1; 230 } 231 return 0; 232 #else /* defined(__OpenBSD__) */ 233 error("Setting routing domain is not supported on this platform"); 234 return -1; 235 #endif 236 } 237 238 /* Characters considered whitespace in strsep calls. */ 239 #define WHITESPACE " \t\r\n" 240 #define QUOTE "\"" 241 242 /* return next token in configuration line */ 243 char * 244 strdelim(char **s) 245 { 246 char *old; 247 int wspace = 0; 248 249 if (*s == NULL) 250 return NULL; 251 252 old = *s; 253 254 *s = strpbrk(*s, WHITESPACE QUOTE "="); 255 if (*s == NULL) 256 return (old); 257 258 if (*s[0] == '\"') { 259 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 260 /* Find matching quote */ 261 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 262 return (NULL); /* no matching quote */ 263 } else { 264 *s[0] = '\0'; 265 *s += strspn(*s + 1, WHITESPACE) + 1; 266 return (old); 267 } 268 } 269 270 /* Allow only one '=' to be skipped */ 271 if (*s[0] == '=') 272 wspace = 1; 273 *s[0] = '\0'; 274 275 /* Skip any extra whitespace after first token */ 276 *s += strspn(*s + 1, WHITESPACE) + 1; 277 if (*s[0] == '=' && !wspace) 278 *s += strspn(*s + 1, WHITESPACE) + 1; 279 280 return (old); 281 } 282 283 struct passwd * 284 pwcopy(struct passwd *pw) 285 { 286 struct passwd *copy = xcalloc(1, sizeof(*copy)); 287 288 copy->pw_name = xstrdup(pw->pw_name); 289 copy->pw_passwd = xstrdup(pw->pw_passwd); 290 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 291 copy->pw_gecos = xstrdup(pw->pw_gecos); 292 #endif 293 copy->pw_uid = pw->pw_uid; 294 copy->pw_gid = pw->pw_gid; 295 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE 296 copy->pw_expire = pw->pw_expire; 297 #endif 298 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE 299 copy->pw_change = pw->pw_change; 300 #endif 301 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 302 copy->pw_class = xstrdup(pw->pw_class); 303 #endif 304 copy->pw_dir = xstrdup(pw->pw_dir); 305 copy->pw_shell = xstrdup(pw->pw_shell); 306 return copy; 307 } 308 309 /* 310 * Convert ASCII string to TCP/IP port number. 311 * Port must be >=0 and <=65535. 312 * Return -1 if invalid. 313 */ 314 int 315 a2port(const char *s) 316 { 317 long long port; 318 const char *errstr; 319 320 port = strtonum(s, 0, 65535, &errstr); 321 if (errstr != NULL) 322 return -1; 323 return (int)port; 324 } 325 326 int 327 a2tun(const char *s, int *remote) 328 { 329 const char *errstr = NULL; 330 char *sp, *ep; 331 int tun; 332 333 if (remote != NULL) { 334 *remote = SSH_TUNID_ANY; 335 sp = xstrdup(s); 336 if ((ep = strchr(sp, ':')) == NULL) { 337 free(sp); 338 return (a2tun(s, NULL)); 339 } 340 ep[0] = '\0'; ep++; 341 *remote = a2tun(ep, NULL); 342 tun = a2tun(sp, NULL); 343 free(sp); 344 return (*remote == SSH_TUNID_ERR ? *remote : tun); 345 } 346 347 if (strcasecmp(s, "any") == 0) 348 return (SSH_TUNID_ANY); 349 350 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 351 if (errstr != NULL) 352 return (SSH_TUNID_ERR); 353 354 return (tun); 355 } 356 357 #define SECONDS 1 358 #define MINUTES (SECONDS * 60) 359 #define HOURS (MINUTES * 60) 360 #define DAYS (HOURS * 24) 361 #define WEEKS (DAYS * 7) 362 363 /* 364 * Convert a time string into seconds; format is 365 * a sequence of: 366 * time[qualifier] 367 * 368 * Valid time qualifiers are: 369 * <none> seconds 370 * s|S seconds 371 * m|M minutes 372 * h|H hours 373 * d|D days 374 * w|W weeks 375 * 376 * Examples: 377 * 90m 90 minutes 378 * 1h30m 90 minutes 379 * 2d 2 days 380 * 1w 1 week 381 * 382 * Return -1 if time string is invalid. 383 */ 384 long 385 convtime(const char *s) 386 { 387 long total, secs, multiplier = 1; 388 const char *p; 389 char *endp; 390 391 errno = 0; 392 total = 0; 393 p = s; 394 395 if (p == NULL || *p == '\0') 396 return -1; 397 398 while (*p) { 399 secs = strtol(p, &endp, 10); 400 if (p == endp || 401 (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) || 402 secs < 0) 403 return -1; 404 405 switch (*endp++) { 406 case '\0': 407 endp--; 408 break; 409 case 's': 410 case 'S': 411 break; 412 case 'm': 413 case 'M': 414 multiplier = MINUTES; 415 break; 416 case 'h': 417 case 'H': 418 multiplier = HOURS; 419 break; 420 case 'd': 421 case 'D': 422 multiplier = DAYS; 423 break; 424 case 'w': 425 case 'W': 426 multiplier = WEEKS; 427 break; 428 default: 429 return -1; 430 } 431 if (secs >= LONG_MAX / multiplier) 432 return -1; 433 secs *= multiplier; 434 if (total >= LONG_MAX - secs) 435 return -1; 436 total += secs; 437 if (total < 0) 438 return -1; 439 p = endp; 440 } 441 442 return total; 443 } 444 445 /* 446 * Returns a standardized host+port identifier string. 447 * Caller must free returned string. 448 */ 449 char * 450 put_host_port(const char *host, u_short port) 451 { 452 char *hoststr; 453 454 if (port == 0 || port == SSH_DEFAULT_PORT) 455 return(xstrdup(host)); 456 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0) 457 fatal("put_host_port: asprintf: %s", strerror(errno)); 458 debug3("put_host_port: %s", hoststr); 459 return hoststr; 460 } 461 462 /* 463 * Search for next delimiter between hostnames/addresses and ports. 464 * Argument may be modified (for termination). 465 * Returns *cp if parsing succeeds. 466 * *cp is set to the start of the next field, if one was found. 467 * The delimiter char, if present, is stored in delim. 468 * If this is the last field, *cp is set to NULL. 469 */ 470 static char * 471 hpdelim2(char **cp, char *delim) 472 { 473 char *s, *old; 474 475 if (cp == NULL || *cp == NULL) 476 return NULL; 477 478 old = s = *cp; 479 if (*s == '[') { 480 if ((s = strchr(s, ']')) == NULL) 481 return NULL; 482 else 483 s++; 484 } else if ((s = strpbrk(s, ":/")) == NULL) 485 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 486 487 switch (*s) { 488 case '\0': 489 *cp = NULL; /* no more fields*/ 490 break; 491 492 case ':': 493 case '/': 494 if (delim != NULL) 495 *delim = *s; 496 *s = '\0'; /* terminate */ 497 *cp = s + 1; 498 break; 499 500 default: 501 return NULL; 502 } 503 504 return old; 505 } 506 507 char * 508 hpdelim(char **cp) 509 { 510 return hpdelim2(cp, NULL); 511 } 512 513 char * 514 cleanhostname(char *host) 515 { 516 if (*host == '[' && host[strlen(host) - 1] == ']') { 517 host[strlen(host) - 1] = '\0'; 518 return (host + 1); 519 } else 520 return host; 521 } 522 523 char * 524 colon(char *cp) 525 { 526 int flag = 0; 527 528 if (*cp == ':') /* Leading colon is part of file name. */ 529 return NULL; 530 if (*cp == '[') 531 flag = 1; 532 533 for (; *cp; ++cp) { 534 if (*cp == '@' && *(cp+1) == '[') 535 flag = 1; 536 if (*cp == ']' && *(cp+1) == ':' && flag) 537 return (cp+1); 538 if (*cp == ':' && !flag) 539 return (cp); 540 if (*cp == '/') 541 return NULL; 542 } 543 return NULL; 544 } 545 546 /* 547 * Parse a [user@]host:[path] string. 548 * Caller must free returned user, host and path. 549 * Any of the pointer return arguments may be NULL (useful for syntax checking). 550 * If user was not specified then *userp will be set to NULL. 551 * If host was not specified then *hostp will be set to NULL. 552 * If path was not specified then *pathp will be set to ".". 553 * Returns 0 on success, -1 on failure. 554 */ 555 int 556 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 557 { 558 char *user = NULL, *host = NULL, *path = NULL; 559 char *sdup, *tmp; 560 int ret = -1; 561 562 if (userp != NULL) 563 *userp = NULL; 564 if (hostp != NULL) 565 *hostp = NULL; 566 if (pathp != NULL) 567 *pathp = NULL; 568 569 sdup = xstrdup(s); 570 571 /* Check for remote syntax: [user@]host:[path] */ 572 if ((tmp = colon(sdup)) == NULL) 573 goto out; 574 575 /* Extract optional path */ 576 *tmp++ = '\0'; 577 if (*tmp == '\0') 578 tmp = "."; 579 path = xstrdup(tmp); 580 581 /* Extract optional user and mandatory host */ 582 tmp = strrchr(sdup, '@'); 583 if (tmp != NULL) { 584 *tmp++ = '\0'; 585 host = xstrdup(cleanhostname(tmp)); 586 if (*sdup != '\0') 587 user = xstrdup(sdup); 588 } else { 589 host = xstrdup(cleanhostname(sdup)); 590 user = NULL; 591 } 592 593 /* Success */ 594 if (userp != NULL) { 595 *userp = user; 596 user = NULL; 597 } 598 if (hostp != NULL) { 599 *hostp = host; 600 host = NULL; 601 } 602 if (pathp != NULL) { 603 *pathp = path; 604 path = NULL; 605 } 606 ret = 0; 607 out: 608 free(sdup); 609 free(user); 610 free(host); 611 free(path); 612 return ret; 613 } 614 615 /* 616 * Parse a [user@]host[:port] string. 617 * Caller must free returned user and host. 618 * Any of the pointer return arguments may be NULL (useful for syntax checking). 619 * If user was not specified then *userp will be set to NULL. 620 * If port was not specified then *portp will be -1. 621 * Returns 0 on success, -1 on failure. 622 */ 623 int 624 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 625 { 626 char *sdup, *cp, *tmp; 627 char *user = NULL, *host = NULL; 628 int port = -1, ret = -1; 629 630 if (userp != NULL) 631 *userp = NULL; 632 if (hostp != NULL) 633 *hostp = NULL; 634 if (portp != NULL) 635 *portp = -1; 636 637 if ((sdup = tmp = strdup(s)) == NULL) 638 return -1; 639 /* Extract optional username */ 640 if ((cp = strrchr(tmp, '@')) != NULL) { 641 *cp = '\0'; 642 if (*tmp == '\0') 643 goto out; 644 if ((user = strdup(tmp)) == NULL) 645 goto out; 646 tmp = cp + 1; 647 } 648 /* Extract mandatory hostname */ 649 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 650 goto out; 651 host = xstrdup(cleanhostname(cp)); 652 /* Convert and verify optional port */ 653 if (tmp != NULL && *tmp != '\0') { 654 if ((port = a2port(tmp)) <= 0) 655 goto out; 656 } 657 /* Success */ 658 if (userp != NULL) { 659 *userp = user; 660 user = NULL; 661 } 662 if (hostp != NULL) { 663 *hostp = host; 664 host = NULL; 665 } 666 if (portp != NULL) 667 *portp = port; 668 ret = 0; 669 out: 670 free(sdup); 671 free(user); 672 free(host); 673 return ret; 674 } 675 676 /* 677 * Converts a two-byte hex string to decimal. 678 * Returns the decimal value or -1 for invalid input. 679 */ 680 static int 681 hexchar(const char *s) 682 { 683 unsigned char result[2]; 684 int i; 685 686 for (i = 0; i < 2; i++) { 687 if (s[i] >= '0' && s[i] <= '9') 688 result[i] = (unsigned char)(s[i] - '0'); 689 else if (s[i] >= 'a' && s[i] <= 'f') 690 result[i] = (unsigned char)(s[i] - 'a') + 10; 691 else if (s[i] >= 'A' && s[i] <= 'F') 692 result[i] = (unsigned char)(s[i] - 'A') + 10; 693 else 694 return -1; 695 } 696 return (result[0] << 4) | result[1]; 697 } 698 699 /* 700 * Decode an url-encoded string. 701 * Returns a newly allocated string on success or NULL on failure. 702 */ 703 static char * 704 urldecode(const char *src) 705 { 706 char *ret, *dst; 707 int ch; 708 709 ret = xmalloc(strlen(src) + 1); 710 for (dst = ret; *src != '\0'; src++) { 711 switch (*src) { 712 case '+': 713 *dst++ = ' '; 714 break; 715 case '%': 716 if (!isxdigit((unsigned char)src[1]) || 717 !isxdigit((unsigned char)src[2]) || 718 (ch = hexchar(src + 1)) == -1) { 719 free(ret); 720 return NULL; 721 } 722 *dst++ = ch; 723 src += 2; 724 break; 725 default: 726 *dst++ = *src; 727 break; 728 } 729 } 730 *dst = '\0'; 731 732 return ret; 733 } 734 735 /* 736 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 737 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 738 * Either user or path may be url-encoded (but not host or port). 739 * Caller must free returned user, host and path. 740 * Any of the pointer return arguments may be NULL (useful for syntax checking) 741 * but the scheme must always be specified. 742 * If user was not specified then *userp will be set to NULL. 743 * If port was not specified then *portp will be -1. 744 * If path was not specified then *pathp will be set to NULL. 745 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 746 */ 747 int 748 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 749 int *portp, char **pathp) 750 { 751 char *uridup, *cp, *tmp, ch; 752 char *user = NULL, *host = NULL, *path = NULL; 753 int port = -1, ret = -1; 754 size_t len; 755 756 len = strlen(scheme); 757 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 758 return 1; 759 uri += len + 3; 760 761 if (userp != NULL) 762 *userp = NULL; 763 if (hostp != NULL) 764 *hostp = NULL; 765 if (portp != NULL) 766 *portp = -1; 767 if (pathp != NULL) 768 *pathp = NULL; 769 770 uridup = tmp = xstrdup(uri); 771 772 /* Extract optional ssh-info (username + connection params) */ 773 if ((cp = strchr(tmp, '@')) != NULL) { 774 char *delim; 775 776 *cp = '\0'; 777 /* Extract username and connection params */ 778 if ((delim = strchr(tmp, ';')) != NULL) { 779 /* Just ignore connection params for now */ 780 *delim = '\0'; 781 } 782 if (*tmp == '\0') { 783 /* Empty username */ 784 goto out; 785 } 786 if ((user = urldecode(tmp)) == NULL) 787 goto out; 788 tmp = cp + 1; 789 } 790 791 /* Extract mandatory hostname */ 792 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 793 goto out; 794 host = xstrdup(cleanhostname(cp)); 795 if (!valid_domain(host, 0, NULL)) 796 goto out; 797 798 if (tmp != NULL && *tmp != '\0') { 799 if (ch == ':') { 800 /* Convert and verify port. */ 801 if ((cp = strchr(tmp, '/')) != NULL) 802 *cp = '\0'; 803 if ((port = a2port(tmp)) <= 0) 804 goto out; 805 tmp = cp ? cp + 1 : NULL; 806 } 807 if (tmp != NULL && *tmp != '\0') { 808 /* Extract optional path */ 809 if ((path = urldecode(tmp)) == NULL) 810 goto out; 811 } 812 } 813 814 /* Success */ 815 if (userp != NULL) { 816 *userp = user; 817 user = NULL; 818 } 819 if (hostp != NULL) { 820 *hostp = host; 821 host = NULL; 822 } 823 if (portp != NULL) 824 *portp = port; 825 if (pathp != NULL) { 826 *pathp = path; 827 path = NULL; 828 } 829 ret = 0; 830 out: 831 free(uridup); 832 free(user); 833 free(host); 834 free(path); 835 return ret; 836 } 837 838 /* function to assist building execv() arguments */ 839 void 840 addargs(arglist *args, char *fmt, ...) 841 { 842 va_list ap; 843 char *cp; 844 u_int nalloc; 845 int r; 846 847 va_start(ap, fmt); 848 r = vasprintf(&cp, fmt, ap); 849 va_end(ap); 850 if (r == -1) 851 fatal("addargs: argument too long"); 852 853 nalloc = args->nalloc; 854 if (args->list == NULL) { 855 nalloc = 32; 856 args->num = 0; 857 } else if (args->num+2 >= nalloc) 858 nalloc *= 2; 859 860 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 861 args->nalloc = nalloc; 862 args->list[args->num++] = cp; 863 args->list[args->num] = NULL; 864 } 865 866 void 867 replacearg(arglist *args, u_int which, char *fmt, ...) 868 { 869 va_list ap; 870 char *cp; 871 int r; 872 873 va_start(ap, fmt); 874 r = vasprintf(&cp, fmt, ap); 875 va_end(ap); 876 if (r == -1) 877 fatal("replacearg: argument too long"); 878 879 if (which >= args->num) 880 fatal("replacearg: tried to replace invalid arg %d >= %d", 881 which, args->num); 882 free(args->list[which]); 883 args->list[which] = cp; 884 } 885 886 void 887 freeargs(arglist *args) 888 { 889 u_int i; 890 891 if (args->list != NULL) { 892 for (i = 0; i < args->num; i++) 893 free(args->list[i]); 894 free(args->list); 895 args->nalloc = args->num = 0; 896 args->list = NULL; 897 } 898 } 899 900 /* 901 * Expands tildes in the file name. Returns data allocated by xmalloc. 902 * Warning: this calls getpw*. 903 */ 904 char * 905 tilde_expand_filename(const char *filename, uid_t uid) 906 { 907 const char *path, *sep; 908 char user[128], *ret; 909 struct passwd *pw; 910 u_int len, slash; 911 912 if (*filename != '~') 913 return (xstrdup(filename)); 914 filename++; 915 916 path = strchr(filename, '/'); 917 if (path != NULL && path > filename) { /* ~user/path */ 918 slash = path - filename; 919 if (slash > sizeof(user) - 1) 920 fatal("tilde_expand_filename: ~username too long"); 921 memcpy(user, filename, slash); 922 user[slash] = '\0'; 923 if ((pw = getpwnam(user)) == NULL) 924 fatal("tilde_expand_filename: No such user %s", user); 925 } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ 926 fatal("tilde_expand_filename: No such uid %ld", (long)uid); 927 928 /* Make sure directory has a trailing '/' */ 929 len = strlen(pw->pw_dir); 930 if (len == 0 || pw->pw_dir[len - 1] != '/') 931 sep = "/"; 932 else 933 sep = ""; 934 935 /* Skip leading '/' from specified path */ 936 if (path != NULL) 937 filename = path + 1; 938 939 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) 940 fatal("tilde_expand_filename: Path too long"); 941 942 return (ret); 943 } 944 945 /* 946 * Expand a string with a set of %[char] escapes. A number of escapes may be 947 * specified as (char *escape_chars, char *replacement) pairs. The list must 948 * be terminated by a NULL escape_char. Returns replaced string in memory 949 * allocated by xmalloc. 950 */ 951 char * 952 percent_expand(const char *string, ...) 953 { 954 #define EXPAND_MAX_KEYS 16 955 u_int num_keys, i, j; 956 struct { 957 const char *key; 958 const char *repl; 959 } keys[EXPAND_MAX_KEYS]; 960 char buf[4096]; 961 va_list ap; 962 963 /* Gather keys */ 964 va_start(ap, string); 965 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 966 keys[num_keys].key = va_arg(ap, char *); 967 if (keys[num_keys].key == NULL) 968 break; 969 keys[num_keys].repl = va_arg(ap, char *); 970 if (keys[num_keys].repl == NULL) 971 fatal("%s: NULL replacement", __func__); 972 } 973 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 974 fatal("%s: too many keys", __func__); 975 va_end(ap); 976 977 /* Expand string */ 978 *buf = '\0'; 979 for (i = 0; *string != '\0'; string++) { 980 if (*string != '%') { 981 append: 982 buf[i++] = *string; 983 if (i >= sizeof(buf)) 984 fatal("%s: string too long", __func__); 985 buf[i] = '\0'; 986 continue; 987 } 988 string++; 989 /* %% case */ 990 if (*string == '%') 991 goto append; 992 if (*string == '\0') 993 fatal("%s: invalid format", __func__); 994 for (j = 0; j < num_keys; j++) { 995 if (strchr(keys[j].key, *string) != NULL) { 996 i = strlcat(buf, keys[j].repl, sizeof(buf)); 997 if (i >= sizeof(buf)) 998 fatal("%s: string too long", __func__); 999 break; 1000 } 1001 } 1002 if (j >= num_keys) 1003 fatal("%s: unknown key %%%c", __func__, *string); 1004 } 1005 return (xstrdup(buf)); 1006 #undef EXPAND_MAX_KEYS 1007 } 1008 1009 /* 1010 * Read an entire line from a public key file into a static buffer, discarding 1011 * lines that exceed the buffer size. Returns 0 on success, -1 on failure. 1012 */ 1013 int 1014 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz, 1015 u_long *lineno) 1016 { 1017 while (fgets(buf, bufsz, f) != NULL) { 1018 if (buf[0] == '\0') 1019 continue; 1020 (*lineno)++; 1021 if (buf[strlen(buf) - 1] == '\n' || feof(f)) { 1022 return 0; 1023 } else { 1024 debug("%s: %s line %lu exceeds size limit", __func__, 1025 filename, *lineno); 1026 /* discard remainder of line */ 1027 while (fgetc(f) != '\n' && !feof(f)) 1028 ; /* nothing */ 1029 } 1030 } 1031 return -1; 1032 } 1033 1034 int 1035 tun_open(int tun, int mode, char **ifname) 1036 { 1037 #if defined(CUSTOM_SYS_TUN_OPEN) 1038 return (sys_tun_open(tun, mode, ifname)); 1039 #elif defined(SSH_TUN_OPENBSD) 1040 struct ifreq ifr; 1041 char name[100]; 1042 int fd = -1, sock; 1043 const char *tunbase = "tun"; 1044 1045 if (ifname != NULL) 1046 *ifname = NULL; 1047 1048 if (mode == SSH_TUNMODE_ETHERNET) 1049 tunbase = "tap"; 1050 1051 /* Open the tunnel device */ 1052 if (tun <= SSH_TUNID_MAX) { 1053 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1054 fd = open(name, O_RDWR); 1055 } else if (tun == SSH_TUNID_ANY) { 1056 for (tun = 100; tun >= 0; tun--) { 1057 snprintf(name, sizeof(name), "/dev/%s%d", 1058 tunbase, tun); 1059 if ((fd = open(name, O_RDWR)) >= 0) 1060 break; 1061 } 1062 } else { 1063 debug("%s: invalid tunnel %u", __func__, tun); 1064 return -1; 1065 } 1066 1067 if (fd < 0) { 1068 debug("%s: %s open: %s", __func__, name, strerror(errno)); 1069 return -1; 1070 } 1071 1072 debug("%s: %s mode %d fd %d", __func__, name, mode, fd); 1073 1074 /* Bring interface up if it is not already */ 1075 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1076 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1077 goto failed; 1078 1079 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1080 debug("%s: get interface %s flags: %s", __func__, 1081 ifr.ifr_name, strerror(errno)); 1082 goto failed; 1083 } 1084 1085 if (!(ifr.ifr_flags & IFF_UP)) { 1086 ifr.ifr_flags |= IFF_UP; 1087 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1088 debug("%s: activate interface %s: %s", __func__, 1089 ifr.ifr_name, strerror(errno)); 1090 goto failed; 1091 } 1092 } 1093 1094 if (ifname != NULL) 1095 *ifname = xstrdup(ifr.ifr_name); 1096 1097 close(sock); 1098 return fd; 1099 1100 failed: 1101 if (fd >= 0) 1102 close(fd); 1103 if (sock >= 0) 1104 close(sock); 1105 return -1; 1106 #else 1107 error("Tunnel interfaces are not supported on this platform"); 1108 return (-1); 1109 #endif 1110 } 1111 1112 void 1113 sanitise_stdfd(void) 1114 { 1115 int nullfd, dupfd; 1116 1117 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1118 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1119 strerror(errno)); 1120 exit(1); 1121 } 1122 while (++dupfd <= STDERR_FILENO) { 1123 /* Only populate closed fds. */ 1124 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1125 if (dup2(nullfd, dupfd) == -1) { 1126 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1127 exit(1); 1128 } 1129 } 1130 } 1131 if (nullfd > STDERR_FILENO) 1132 close(nullfd); 1133 } 1134 1135 char * 1136 tohex(const void *vp, size_t l) 1137 { 1138 const u_char *p = (const u_char *)vp; 1139 char b[3], *r; 1140 size_t i, hl; 1141 1142 if (l > 65536) 1143 return xstrdup("tohex: length > 65536"); 1144 1145 hl = l * 2 + 1; 1146 r = xcalloc(1, hl); 1147 for (i = 0; i < l; i++) { 1148 snprintf(b, sizeof(b), "%02x", p[i]); 1149 strlcat(r, b, hl); 1150 } 1151 return (r); 1152 } 1153 1154 u_int64_t 1155 get_u64(const void *vp) 1156 { 1157 const u_char *p = (const u_char *)vp; 1158 u_int64_t v; 1159 1160 v = (u_int64_t)p[0] << 56; 1161 v |= (u_int64_t)p[1] << 48; 1162 v |= (u_int64_t)p[2] << 40; 1163 v |= (u_int64_t)p[3] << 32; 1164 v |= (u_int64_t)p[4] << 24; 1165 v |= (u_int64_t)p[5] << 16; 1166 v |= (u_int64_t)p[6] << 8; 1167 v |= (u_int64_t)p[7]; 1168 1169 return (v); 1170 } 1171 1172 u_int32_t 1173 get_u32(const void *vp) 1174 { 1175 const u_char *p = (const u_char *)vp; 1176 u_int32_t v; 1177 1178 v = (u_int32_t)p[0] << 24; 1179 v |= (u_int32_t)p[1] << 16; 1180 v |= (u_int32_t)p[2] << 8; 1181 v |= (u_int32_t)p[3]; 1182 1183 return (v); 1184 } 1185 1186 u_int32_t 1187 get_u32_le(const void *vp) 1188 { 1189 const u_char *p = (const u_char *)vp; 1190 u_int32_t v; 1191 1192 v = (u_int32_t)p[0]; 1193 v |= (u_int32_t)p[1] << 8; 1194 v |= (u_int32_t)p[2] << 16; 1195 v |= (u_int32_t)p[3] << 24; 1196 1197 return (v); 1198 } 1199 1200 u_int16_t 1201 get_u16(const void *vp) 1202 { 1203 const u_char *p = (const u_char *)vp; 1204 u_int16_t v; 1205 1206 v = (u_int16_t)p[0] << 8; 1207 v |= (u_int16_t)p[1]; 1208 1209 return (v); 1210 } 1211 1212 void 1213 put_u64(void *vp, u_int64_t v) 1214 { 1215 u_char *p = (u_char *)vp; 1216 1217 p[0] = (u_char)(v >> 56) & 0xff; 1218 p[1] = (u_char)(v >> 48) & 0xff; 1219 p[2] = (u_char)(v >> 40) & 0xff; 1220 p[3] = (u_char)(v >> 32) & 0xff; 1221 p[4] = (u_char)(v >> 24) & 0xff; 1222 p[5] = (u_char)(v >> 16) & 0xff; 1223 p[6] = (u_char)(v >> 8) & 0xff; 1224 p[7] = (u_char)v & 0xff; 1225 } 1226 1227 void 1228 put_u32(void *vp, u_int32_t v) 1229 { 1230 u_char *p = (u_char *)vp; 1231 1232 p[0] = (u_char)(v >> 24) & 0xff; 1233 p[1] = (u_char)(v >> 16) & 0xff; 1234 p[2] = (u_char)(v >> 8) & 0xff; 1235 p[3] = (u_char)v & 0xff; 1236 } 1237 1238 void 1239 put_u32_le(void *vp, u_int32_t v) 1240 { 1241 u_char *p = (u_char *)vp; 1242 1243 p[0] = (u_char)v & 0xff; 1244 p[1] = (u_char)(v >> 8) & 0xff; 1245 p[2] = (u_char)(v >> 16) & 0xff; 1246 p[3] = (u_char)(v >> 24) & 0xff; 1247 } 1248 1249 void 1250 put_u16(void *vp, u_int16_t v) 1251 { 1252 u_char *p = (u_char *)vp; 1253 1254 p[0] = (u_char)(v >> 8) & 0xff; 1255 p[1] = (u_char)v & 0xff; 1256 } 1257 1258 void 1259 ms_subtract_diff(struct timeval *start, int *ms) 1260 { 1261 struct timeval diff, finish; 1262 1263 monotime_tv(&finish); 1264 timersub(&finish, start, &diff); 1265 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1266 } 1267 1268 void 1269 ms_to_timeval(struct timeval *tv, int ms) 1270 { 1271 if (ms < 0) 1272 ms = 0; 1273 tv->tv_sec = ms / 1000; 1274 tv->tv_usec = (ms % 1000) * 1000; 1275 } 1276 1277 void 1278 monotime_ts(struct timespec *ts) 1279 { 1280 struct timeval tv; 1281 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \ 1282 defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME)) 1283 static int gettime_failed = 0; 1284 1285 if (!gettime_failed) { 1286 # ifdef CLOCK_BOOTTIME 1287 if (clock_gettime(CLOCK_BOOTTIME, ts) == 0) 1288 return; 1289 # endif /* CLOCK_BOOTTIME */ 1290 # ifdef CLOCK_MONOTONIC 1291 if (clock_gettime(CLOCK_MONOTONIC, ts) == 0) 1292 return; 1293 # endif /* CLOCK_MONOTONIC */ 1294 # ifdef CLOCK_REALTIME 1295 /* Not monotonic, but we're almost out of options here. */ 1296 if (clock_gettime(CLOCK_REALTIME, ts) == 0) 1297 return; 1298 # endif /* CLOCK_REALTIME */ 1299 debug3("clock_gettime: %s", strerror(errno)); 1300 gettime_failed = 1; 1301 } 1302 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */ 1303 gettimeofday(&tv, NULL); 1304 ts->tv_sec = tv.tv_sec; 1305 ts->tv_nsec = (long)tv.tv_usec * 1000; 1306 } 1307 1308 void 1309 monotime_tv(struct timeval *tv) 1310 { 1311 struct timespec ts; 1312 1313 monotime_ts(&ts); 1314 tv->tv_sec = ts.tv_sec; 1315 tv->tv_usec = ts.tv_nsec / 1000; 1316 } 1317 1318 time_t 1319 monotime(void) 1320 { 1321 struct timespec ts; 1322 1323 monotime_ts(&ts); 1324 return ts.tv_sec; 1325 } 1326 1327 double 1328 monotime_double(void) 1329 { 1330 struct timespec ts; 1331 1332 monotime_ts(&ts); 1333 return ts.tv_sec + ((double)ts.tv_nsec / 1000000000); 1334 } 1335 1336 void 1337 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1338 { 1339 bw->buflen = buflen; 1340 bw->rate = kbps; 1341 bw->thresh = bw->rate; 1342 bw->lamt = 0; 1343 timerclear(&bw->bwstart); 1344 timerclear(&bw->bwend); 1345 } 1346 1347 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1348 void 1349 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1350 { 1351 u_int64_t waitlen; 1352 struct timespec ts, rm; 1353 1354 if (!timerisset(&bw->bwstart)) { 1355 monotime_tv(&bw->bwstart); 1356 return; 1357 } 1358 1359 bw->lamt += read_len; 1360 if (bw->lamt < bw->thresh) 1361 return; 1362 1363 monotime_tv(&bw->bwend); 1364 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1365 if (!timerisset(&bw->bwend)) 1366 return; 1367 1368 bw->lamt *= 8; 1369 waitlen = (double)1000000L * bw->lamt / bw->rate; 1370 1371 bw->bwstart.tv_sec = waitlen / 1000000L; 1372 bw->bwstart.tv_usec = waitlen % 1000000L; 1373 1374 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1375 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1376 1377 /* Adjust the wait time */ 1378 if (bw->bwend.tv_sec) { 1379 bw->thresh /= 2; 1380 if (bw->thresh < bw->buflen / 4) 1381 bw->thresh = bw->buflen / 4; 1382 } else if (bw->bwend.tv_usec < 10000) { 1383 bw->thresh *= 2; 1384 if (bw->thresh > bw->buflen * 8) 1385 bw->thresh = bw->buflen * 8; 1386 } 1387 1388 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1389 while (nanosleep(&ts, &rm) == -1) { 1390 if (errno != EINTR) 1391 break; 1392 ts = rm; 1393 } 1394 } 1395 1396 bw->lamt = 0; 1397 monotime_tv(&bw->bwstart); 1398 } 1399 1400 /* Make a template filename for mk[sd]temp() */ 1401 void 1402 mktemp_proto(char *s, size_t len) 1403 { 1404 const char *tmpdir; 1405 int r; 1406 1407 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1408 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1409 if (r > 0 && (size_t)r < len) 1410 return; 1411 } 1412 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1413 if (r < 0 || (size_t)r >= len) 1414 fatal("%s: template string too short", __func__); 1415 } 1416 1417 static const struct { 1418 const char *name; 1419 int value; 1420 } ipqos[] = { 1421 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1422 { "af11", IPTOS_DSCP_AF11 }, 1423 { "af12", IPTOS_DSCP_AF12 }, 1424 { "af13", IPTOS_DSCP_AF13 }, 1425 { "af21", IPTOS_DSCP_AF21 }, 1426 { "af22", IPTOS_DSCP_AF22 }, 1427 { "af23", IPTOS_DSCP_AF23 }, 1428 { "af31", IPTOS_DSCP_AF31 }, 1429 { "af32", IPTOS_DSCP_AF32 }, 1430 { "af33", IPTOS_DSCP_AF33 }, 1431 { "af41", IPTOS_DSCP_AF41 }, 1432 { "af42", IPTOS_DSCP_AF42 }, 1433 { "af43", IPTOS_DSCP_AF43 }, 1434 { "cs0", IPTOS_DSCP_CS0 }, 1435 { "cs1", IPTOS_DSCP_CS1 }, 1436 { "cs2", IPTOS_DSCP_CS2 }, 1437 { "cs3", IPTOS_DSCP_CS3 }, 1438 { "cs4", IPTOS_DSCP_CS4 }, 1439 { "cs5", IPTOS_DSCP_CS5 }, 1440 { "cs6", IPTOS_DSCP_CS6 }, 1441 { "cs7", IPTOS_DSCP_CS7 }, 1442 { "ef", IPTOS_DSCP_EF }, 1443 { "lowdelay", IPTOS_LOWDELAY }, 1444 { "throughput", IPTOS_THROUGHPUT }, 1445 { "reliability", IPTOS_RELIABILITY }, 1446 { NULL, -1 } 1447 }; 1448 1449 int 1450 parse_ipqos(const char *cp) 1451 { 1452 u_int i; 1453 char *ep; 1454 long val; 1455 1456 if (cp == NULL) 1457 return -1; 1458 for (i = 0; ipqos[i].name != NULL; i++) { 1459 if (strcasecmp(cp, ipqos[i].name) == 0) 1460 return ipqos[i].value; 1461 } 1462 /* Try parsing as an integer */ 1463 val = strtol(cp, &ep, 0); 1464 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1465 return -1; 1466 return val; 1467 } 1468 1469 const char * 1470 iptos2str(int iptos) 1471 { 1472 int i; 1473 static char iptos_str[sizeof "0xff"]; 1474 1475 for (i = 0; ipqos[i].name != NULL; i++) { 1476 if (ipqos[i].value == iptos) 1477 return ipqos[i].name; 1478 } 1479 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1480 return iptos_str; 1481 } 1482 1483 void 1484 lowercase(char *s) 1485 { 1486 for (; *s; s++) 1487 *s = tolower((u_char)*s); 1488 } 1489 1490 int 1491 unix_listener(const char *path, int backlog, int unlink_first) 1492 { 1493 struct sockaddr_un sunaddr; 1494 int saved_errno, sock; 1495 1496 memset(&sunaddr, 0, sizeof(sunaddr)); 1497 sunaddr.sun_family = AF_UNIX; 1498 if (strlcpy(sunaddr.sun_path, path, 1499 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1500 error("%s: path \"%s\" too long for Unix domain socket", 1501 __func__, path); 1502 errno = ENAMETOOLONG; 1503 return -1; 1504 } 1505 1506 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1507 if (sock < 0) { 1508 saved_errno = errno; 1509 error("%s: socket: %.100s", __func__, strerror(errno)); 1510 errno = saved_errno; 1511 return -1; 1512 } 1513 if (unlink_first == 1) { 1514 if (unlink(path) != 0 && errno != ENOENT) 1515 error("unlink(%s): %.100s", path, strerror(errno)); 1516 } 1517 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) { 1518 saved_errno = errno; 1519 error("%s: cannot bind to path %s: %s", 1520 __func__, path, strerror(errno)); 1521 close(sock); 1522 errno = saved_errno; 1523 return -1; 1524 } 1525 if (listen(sock, backlog) < 0) { 1526 saved_errno = errno; 1527 error("%s: cannot listen on path %s: %s", 1528 __func__, path, strerror(errno)); 1529 close(sock); 1530 unlink(path); 1531 errno = saved_errno; 1532 return -1; 1533 } 1534 return sock; 1535 } 1536 1537 void 1538 sock_set_v6only(int s) 1539 { 1540 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__) 1541 int on = 1; 1542 1543 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s); 1544 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) 1545 error("setsockopt IPV6_V6ONLY: %s", strerror(errno)); 1546 #endif 1547 } 1548 1549 /* 1550 * Compares two strings that maybe be NULL. Returns non-zero if strings 1551 * are both NULL or are identical, returns zero otherwise. 1552 */ 1553 static int 1554 strcmp_maybe_null(const char *a, const char *b) 1555 { 1556 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1557 return 0; 1558 if (a != NULL && strcmp(a, b) != 0) 1559 return 0; 1560 return 1; 1561 } 1562 1563 /* 1564 * Compare two forwards, returning non-zero if they are identical or 1565 * zero otherwise. 1566 */ 1567 int 1568 forward_equals(const struct Forward *a, const struct Forward *b) 1569 { 1570 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1571 return 0; 1572 if (a->listen_port != b->listen_port) 1573 return 0; 1574 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1575 return 0; 1576 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1577 return 0; 1578 if (a->connect_port != b->connect_port) 1579 return 0; 1580 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1581 return 0; 1582 /* allocated_port and handle are not checked */ 1583 return 1; 1584 } 1585 1586 static int 1587 ipport_reserved(void) 1588 { 1589 #if __FreeBSD__ 1590 int old, ret; 1591 size_t len = sizeof(old); 1592 1593 ret = sysctlbyname("net.inet.ip.portrange.reservedhigh", 1594 &old, &len, NULL, 0); 1595 if (ret == 0) 1596 return (old + 1); 1597 #endif 1598 return (IPPORT_RESERVED); 1599 } 1600 1601 /* returns 1 if bind to specified port by specified user is permitted */ 1602 int 1603 bind_permitted(int port, uid_t uid) 1604 { 1605 1606 if (port < ipport_reserved() && uid != 0) 1607 return 0; 1608 return 1; 1609 } 1610 1611 /* returns 1 if process is already daemonized, 0 otherwise */ 1612 int 1613 daemonized(void) 1614 { 1615 int fd; 1616 1617 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1618 close(fd); 1619 return 0; /* have controlling terminal */ 1620 } 1621 if (getppid() != 1) 1622 return 0; /* parent is not init */ 1623 if (getsid(0) != getpid()) 1624 return 0; /* not session leader */ 1625 debug3("already daemonized"); 1626 return 1; 1627 } 1628 1629 1630 /* 1631 * Splits 's' into an argument vector. Handles quoted string and basic 1632 * escape characters (\\, \", \'). Caller must free the argument vector 1633 * and its members. 1634 */ 1635 int 1636 argv_split(const char *s, int *argcp, char ***argvp) 1637 { 1638 int r = SSH_ERR_INTERNAL_ERROR; 1639 int argc = 0, quote, i, j; 1640 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1641 1642 *argvp = NULL; 1643 *argcp = 0; 1644 1645 for (i = 0; s[i] != '\0'; i++) { 1646 /* Skip leading whitespace */ 1647 if (s[i] == ' ' || s[i] == '\t') 1648 continue; 1649 1650 /* Start of a token */ 1651 quote = 0; 1652 if (s[i] == '\\' && 1653 (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\')) 1654 i++; 1655 else if (s[i] == '\'' || s[i] == '"') 1656 quote = s[i++]; 1657 1658 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1659 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1660 argv[argc] = NULL; 1661 1662 /* Copy the token in, removing escapes */ 1663 for (j = 0; s[i] != '\0'; i++) { 1664 if (s[i] == '\\') { 1665 if (s[i + 1] == '\'' || 1666 s[i + 1] == '\"' || 1667 s[i + 1] == '\\') { 1668 i++; /* Skip '\' */ 1669 arg[j++] = s[i]; 1670 } else { 1671 /* Unrecognised escape */ 1672 arg[j++] = s[i]; 1673 } 1674 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1675 break; /* done */ 1676 else if (quote != 0 && s[i] == quote) 1677 break; /* done */ 1678 else 1679 arg[j++] = s[i]; 1680 } 1681 if (s[i] == '\0') { 1682 if (quote != 0) { 1683 /* Ran out of string looking for close quote */ 1684 r = SSH_ERR_INVALID_FORMAT; 1685 goto out; 1686 } 1687 break; 1688 } 1689 } 1690 /* Success */ 1691 *argcp = argc; 1692 *argvp = argv; 1693 argc = 0; 1694 argv = NULL; 1695 r = 0; 1696 out: 1697 if (argc != 0 && argv != NULL) { 1698 for (i = 0; i < argc; i++) 1699 free(argv[i]); 1700 free(argv); 1701 } 1702 return r; 1703 } 1704 1705 /* 1706 * Reassemble an argument vector into a string, quoting and escaping as 1707 * necessary. Caller must free returned string. 1708 */ 1709 char * 1710 argv_assemble(int argc, char **argv) 1711 { 1712 int i, j, ws, r; 1713 char c, *ret; 1714 struct sshbuf *buf, *arg; 1715 1716 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1717 fatal("%s: sshbuf_new failed", __func__); 1718 1719 for (i = 0; i < argc; i++) { 1720 ws = 0; 1721 sshbuf_reset(arg); 1722 for (j = 0; argv[i][j] != '\0'; j++) { 1723 r = 0; 1724 c = argv[i][j]; 1725 switch (c) { 1726 case ' ': 1727 case '\t': 1728 ws = 1; 1729 r = sshbuf_put_u8(arg, c); 1730 break; 1731 case '\\': 1732 case '\'': 1733 case '"': 1734 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 1735 break; 1736 /* FALLTHROUGH */ 1737 default: 1738 r = sshbuf_put_u8(arg, c); 1739 break; 1740 } 1741 if (r != 0) 1742 fatal("%s: sshbuf_put_u8: %s", 1743 __func__, ssh_err(r)); 1744 } 1745 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 1746 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 1747 (r = sshbuf_putb(buf, arg)) != 0 || 1748 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 1749 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1750 } 1751 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 1752 fatal("%s: malloc failed", __func__); 1753 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 1754 ret[sshbuf_len(buf)] = '\0'; 1755 sshbuf_free(buf); 1756 sshbuf_free(arg); 1757 return ret; 1758 } 1759 1760 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 1761 int 1762 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 1763 { 1764 int status; 1765 1766 while (waitpid(pid, &status, 0) == -1) { 1767 if (errno != EINTR) { 1768 error("%s: waitpid: %s", tag, strerror(errno)); 1769 return -1; 1770 } 1771 } 1772 if (WIFSIGNALED(status)) { 1773 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 1774 return -1; 1775 } else if (WEXITSTATUS(status) != 0) { 1776 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 1777 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 1778 return -1; 1779 } 1780 return 0; 1781 } 1782 1783 /* 1784 * Check a given path for security. This is defined as all components 1785 * of the path to the file must be owned by either the owner of 1786 * of the file or root and no directories must be group or world writable. 1787 * 1788 * XXX Should any specific check be done for sym links ? 1789 * 1790 * Takes a file name, its stat information (preferably from fstat() to 1791 * avoid races), the uid of the expected owner, their home directory and an 1792 * error buffer plus max size as arguments. 1793 * 1794 * Returns 0 on success and -1 on failure 1795 */ 1796 int 1797 safe_path(const char *name, struct stat *stp, const char *pw_dir, 1798 uid_t uid, char *err, size_t errlen) 1799 { 1800 char buf[PATH_MAX], homedir[PATH_MAX]; 1801 char *cp; 1802 int comparehome = 0; 1803 struct stat st; 1804 1805 if (realpath(name, buf) == NULL) { 1806 snprintf(err, errlen, "realpath %s failed: %s", name, 1807 strerror(errno)); 1808 return -1; 1809 } 1810 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 1811 comparehome = 1; 1812 1813 if (!S_ISREG(stp->st_mode)) { 1814 snprintf(err, errlen, "%s is not a regular file", buf); 1815 return -1; 1816 } 1817 if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || 1818 (stp->st_mode & 022) != 0) { 1819 snprintf(err, errlen, "bad ownership or modes for file %s", 1820 buf); 1821 return -1; 1822 } 1823 1824 /* for each component of the canonical path, walking upwards */ 1825 for (;;) { 1826 if ((cp = dirname(buf)) == NULL) { 1827 snprintf(err, errlen, "dirname() failed"); 1828 return -1; 1829 } 1830 strlcpy(buf, cp, sizeof(buf)); 1831 1832 if (stat(buf, &st) < 0 || 1833 (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || 1834 (st.st_mode & 022) != 0) { 1835 snprintf(err, errlen, 1836 "bad ownership or modes for directory %s", buf); 1837 return -1; 1838 } 1839 1840 /* If are past the homedir then we can stop */ 1841 if (comparehome && strcmp(homedir, buf) == 0) 1842 break; 1843 1844 /* 1845 * dirname should always complete with a "/" path, 1846 * but we can be paranoid and check for "." too 1847 */ 1848 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 1849 break; 1850 } 1851 return 0; 1852 } 1853 1854 /* 1855 * Version of safe_path() that accepts an open file descriptor to 1856 * avoid races. 1857 * 1858 * Returns 0 on success and -1 on failure 1859 */ 1860 int 1861 safe_path_fd(int fd, const char *file, struct passwd *pw, 1862 char *err, size_t errlen) 1863 { 1864 struct stat st; 1865 1866 /* check the open file to avoid races */ 1867 if (fstat(fd, &st) < 0) { 1868 snprintf(err, errlen, "cannot stat file %s: %s", 1869 file, strerror(errno)); 1870 return -1; 1871 } 1872 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 1873 } 1874 1875 /* 1876 * Sets the value of the given variable in the environment. If the variable 1877 * already exists, its value is overridden. 1878 */ 1879 void 1880 child_set_env(char ***envp, u_int *envsizep, const char *name, 1881 const char *value) 1882 { 1883 char **env; 1884 u_int envsize; 1885 u_int i, namelen; 1886 1887 if (strchr(name, '=') != NULL) { 1888 error("Invalid environment variable \"%.100s\"", name); 1889 return; 1890 } 1891 1892 /* 1893 * If we're passed an uninitialized list, allocate a single null 1894 * entry before continuing. 1895 */ 1896 if (*envp == NULL && *envsizep == 0) { 1897 *envp = xmalloc(sizeof(char *)); 1898 *envp[0] = NULL; 1899 *envsizep = 1; 1900 } 1901 1902 /* 1903 * Find the slot where the value should be stored. If the variable 1904 * already exists, we reuse the slot; otherwise we append a new slot 1905 * at the end of the array, expanding if necessary. 1906 */ 1907 env = *envp; 1908 namelen = strlen(name); 1909 for (i = 0; env[i]; i++) 1910 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 1911 break; 1912 if (env[i]) { 1913 /* Reuse the slot. */ 1914 free(env[i]); 1915 } else { 1916 /* New variable. Expand if necessary. */ 1917 envsize = *envsizep; 1918 if (i >= envsize - 1) { 1919 if (envsize >= 1000) 1920 fatal("child_set_env: too many env vars"); 1921 envsize += 50; 1922 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 1923 *envsizep = envsize; 1924 } 1925 /* Need to set the NULL pointer at end of array beyond the new slot. */ 1926 env[i + 1] = NULL; 1927 } 1928 1929 /* Allocate space and format the variable in the appropriate slot. */ 1930 /* XXX xasprintf */ 1931 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 1932 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 1933 } 1934 1935 /* 1936 * Check and optionally lowercase a domain name, also removes trailing '.' 1937 * Returns 1 on success and 0 on failure, storing an error message in errstr. 1938 */ 1939 int 1940 valid_domain(char *name, int makelower, const char **errstr) 1941 { 1942 size_t i, l = strlen(name); 1943 u_char c, last = '\0'; 1944 static char errbuf[256]; 1945 1946 if (l == 0) { 1947 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 1948 goto bad; 1949 } 1950 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 1951 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 1952 "starts with invalid character", name); 1953 goto bad; 1954 } 1955 for (i = 0; i < l; i++) { 1956 c = tolower((u_char)name[i]); 1957 if (makelower) 1958 name[i] = (char)c; 1959 if (last == '.' && c == '.') { 1960 snprintf(errbuf, sizeof(errbuf), "domain name " 1961 "\"%.100s\" contains consecutive separators", name); 1962 goto bad; 1963 } 1964 if (c != '.' && c != '-' && !isalnum(c) && 1965 c != '_') /* technically invalid, but common */ { 1966 snprintf(errbuf, sizeof(errbuf), "domain name " 1967 "\"%.100s\" contains invalid characters", name); 1968 goto bad; 1969 } 1970 last = c; 1971 } 1972 if (name[l - 1] == '.') 1973 name[l - 1] = '\0'; 1974 if (errstr != NULL) 1975 *errstr = NULL; 1976 return 1; 1977 bad: 1978 if (errstr != NULL) 1979 *errstr = errbuf; 1980 return 0; 1981 } 1982 1983 const char * 1984 atoi_err(const char *nptr, int *val) 1985 { 1986 const char *errstr = NULL; 1987 long long num; 1988 1989 if (nptr == NULL || *nptr == '\0') 1990 return "missing"; 1991 num = strtonum(nptr, 0, INT_MAX, &errstr); 1992 if (errstr == NULL) 1993 *val = (int)num; 1994 return errstr; 1995 } 1996 1997 int 1998 parse_absolute_time(const char *s, uint64_t *tp) 1999 { 2000 struct tm tm; 2001 time_t tt; 2002 char buf[32], *fmt; 2003 2004 *tp = 0; 2005 2006 /* 2007 * POSIX strptime says "The application shall ensure that there 2008 * is white-space or other non-alphanumeric characters between 2009 * any two conversion specifications" so arrange things this way. 2010 */ 2011 switch (strlen(s)) { 2012 case 8: /* YYYYMMDD */ 2013 fmt = "%Y-%m-%d"; 2014 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2015 break; 2016 case 12: /* YYYYMMDDHHMM */ 2017 fmt = "%Y-%m-%dT%H:%M"; 2018 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2019 s, s + 4, s + 6, s + 8, s + 10); 2020 break; 2021 case 14: /* YYYYMMDDHHMMSS */ 2022 fmt = "%Y-%m-%dT%H:%M:%S"; 2023 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2024 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2025 break; 2026 default: 2027 return SSH_ERR_INVALID_FORMAT; 2028 } 2029 2030 memset(&tm, 0, sizeof(tm)); 2031 if (strptime(buf, fmt, &tm) == NULL) 2032 return SSH_ERR_INVALID_FORMAT; 2033 if ((tt = mktime(&tm)) < 0) 2034 return SSH_ERR_INVALID_FORMAT; 2035 /* success */ 2036 *tp = (uint64_t)tt; 2037 return 0; 2038 } 2039 2040 void 2041 format_absolute_time(uint64_t t, char *buf, size_t len) 2042 { 2043 time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */ 2044 struct tm tm; 2045 2046 localtime_r(&tt, &tm); 2047 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2048 } 2049