1 /* $NetBSD: misc.c,v 1.17 2018/04/06 18:59:00 christos Exp $ */ 2 /* $OpenBSD: misc.c,v 1.127 2018/03/12 00:52:01 djm Exp $ */ 3 /* 4 * Copyright (c) 2000 Markus Friedl. All rights reserved. 5 * Copyright (c) 2005,2006 Damien Miller. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 __RCSID("$NetBSD: misc.c,v 1.17 2018/04/06 18:59:00 christos Exp $"); 30 #include <sys/types.h> 31 #include <sys/ioctl.h> 32 #include <sys/socket.h> 33 #include <sys/stat.h> 34 #include <sys/time.h> 35 #include <sys/wait.h> 36 #include <sys/un.h> 37 38 #include <net/if.h> 39 #include <net/if_tun.h> 40 #include <netinet/in.h> 41 #include <netinet/ip.h> 42 #include <netinet/tcp.h> 43 44 #include <ctype.h> 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <netdb.h> 48 #include <paths.h> 49 #include <pwd.h> 50 #include <libgen.h> 51 #include <limits.h> 52 #include <signal.h> 53 #include <stdarg.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 59 #include "xmalloc.h" 60 #include "misc.h" 61 #include "log.h" 62 #include "ssh.h" 63 #include "sshbuf.h" 64 #include "ssherr.h" 65 #include "uidswap.h" 66 67 /* remove newline at end of string */ 68 char * 69 chop(char *s) 70 { 71 char *t = s; 72 while (*t) { 73 if (*t == '\n' || *t == '\r') { 74 *t = '\0'; 75 return s; 76 } 77 t++; 78 } 79 return s; 80 81 } 82 83 /* set/unset filedescriptor to non-blocking */ 84 int 85 set_nonblock(int fd) 86 { 87 int val; 88 89 val = fcntl(fd, F_GETFL); 90 if (val < 0) { 91 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 92 return (-1); 93 } 94 if (val & O_NONBLOCK) { 95 debug3("fd %d is O_NONBLOCK", fd); 96 return (0); 97 } 98 debug2("fd %d setting O_NONBLOCK", fd); 99 val |= O_NONBLOCK; 100 if (fcntl(fd, F_SETFL, val) == -1) { 101 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 102 strerror(errno)); 103 return (-1); 104 } 105 return (0); 106 } 107 108 int 109 unset_nonblock(int fd) 110 { 111 int val; 112 113 val = fcntl(fd, F_GETFL); 114 if (val < 0) { 115 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 116 return (-1); 117 } 118 if (!(val & O_NONBLOCK)) { 119 debug3("fd %d is not O_NONBLOCK", fd); 120 return (0); 121 } 122 debug("fd %d clearing O_NONBLOCK", fd); 123 val &= ~O_NONBLOCK; 124 if (fcntl(fd, F_SETFL, val) == -1) { 125 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 126 fd, strerror(errno)); 127 return (-1); 128 } 129 return (0); 130 } 131 132 const char * 133 ssh_gai_strerror(int gaierr) 134 { 135 if (gaierr == EAI_SYSTEM && errno != 0) 136 return strerror(errno); 137 return gai_strerror(gaierr); 138 } 139 140 /* disable nagle on socket */ 141 void 142 set_nodelay(int fd) 143 { 144 int opt; 145 socklen_t optlen; 146 147 optlen = sizeof opt; 148 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 149 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 150 return; 151 } 152 if (opt == 1) { 153 debug2("fd %d is TCP_NODELAY", fd); 154 return; 155 } 156 opt = 1; 157 debug2("fd %d setting TCP_NODELAY", fd); 158 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 159 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 160 } 161 162 /* Allow local port reuse in TIME_WAIT */ 163 int 164 set_reuseaddr(int fd) 165 { 166 int on = 1; 167 168 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 169 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 170 return -1; 171 } 172 return 0; 173 } 174 175 /* Get/set routing domain */ 176 char * 177 get_rdomain(int fd) 178 { 179 #ifdef SO_RTABLE 180 int rtable; 181 char *ret; 182 socklen_t len = sizeof(rtable); 183 184 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 185 error("Failed to get routing domain for fd %d: %s", 186 fd, strerror(errno)); 187 return NULL; 188 } 189 xasprintf(&ret, "%d", rtable); 190 return ret; 191 #else 192 return NULL; 193 #endif 194 } 195 196 int 197 set_rdomain(int fd, const char *name) 198 { 199 #ifdef SO_RTABLE 200 int rtable; 201 const char *errstr; 202 203 if (name == NULL) 204 return 0; /* default table */ 205 206 rtable = (int)strtonum(name, 0, 255, &errstr); 207 if (errstr != NULL) { 208 /* Shouldn't happen */ 209 error("Invalid routing domain \"%s\": %s", name, errstr); 210 return -1; 211 } 212 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 213 &rtable, sizeof(rtable)) == -1) { 214 error("Failed to set routing domain %d on fd %d: %s", 215 rtable, fd, strerror(errno)); 216 return -1; 217 } 218 return 0; 219 #else 220 return -1; 221 #endif 222 } 223 224 /* Characters considered whitespace in strsep calls. */ 225 #define WHITESPACE " \t\r\n" 226 #define QUOTE "\"" 227 228 /* return next token in configuration line */ 229 char * 230 strdelim(char **s) 231 { 232 char *old; 233 int wspace = 0; 234 235 if (*s == NULL) 236 return NULL; 237 238 old = *s; 239 240 *s = strpbrk(*s, WHITESPACE QUOTE "="); 241 if (*s == NULL) 242 return (old); 243 244 if (*s[0] == '\"') { 245 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 246 /* Find matching quote */ 247 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 248 return (NULL); /* no matching quote */ 249 } else { 250 *s[0] = '\0'; 251 *s += strspn(*s + 1, WHITESPACE) + 1; 252 return (old); 253 } 254 } 255 256 /* Allow only one '=' to be skipped */ 257 if (*s[0] == '=') 258 wspace = 1; 259 *s[0] = '\0'; 260 261 /* Skip any extra whitespace after first token */ 262 *s += strspn(*s + 1, WHITESPACE) + 1; 263 if (*s[0] == '=' && !wspace) 264 *s += strspn(*s + 1, WHITESPACE) + 1; 265 266 return (old); 267 } 268 269 struct passwd * 270 pwcopy(struct passwd *pw) 271 { 272 struct passwd *copy = xcalloc(1, sizeof(*copy)); 273 274 copy->pw_name = xstrdup(pw->pw_name); 275 copy->pw_passwd = xstrdup(pw->pw_passwd); 276 copy->pw_gecos = xstrdup(pw->pw_gecos); 277 copy->pw_uid = pw->pw_uid; 278 copy->pw_gid = pw->pw_gid; 279 copy->pw_expire = pw->pw_expire; 280 copy->pw_change = pw->pw_change; 281 copy->pw_class = xstrdup(pw->pw_class); 282 copy->pw_dir = xstrdup(pw->pw_dir); 283 copy->pw_shell = xstrdup(pw->pw_shell); 284 return copy; 285 } 286 287 /* 288 * Convert ASCII string to TCP/IP port number. 289 * Port must be >=0 and <=65535. 290 * Return -1 if invalid. 291 */ 292 int 293 a2port(const char *s) 294 { 295 long long port; 296 const char *errstr; 297 298 port = strtonum(s, 0, 65535, &errstr); 299 if (errstr != NULL) 300 return -1; 301 return (int)port; 302 } 303 304 int 305 a2tun(const char *s, int *remote) 306 { 307 const char *errstr = NULL; 308 char *sp, *ep; 309 int tun; 310 311 if (remote != NULL) { 312 *remote = SSH_TUNID_ANY; 313 sp = xstrdup(s); 314 if ((ep = strchr(sp, ':')) == NULL) { 315 free(sp); 316 return (a2tun(s, NULL)); 317 } 318 ep[0] = '\0'; ep++; 319 *remote = a2tun(ep, NULL); 320 tun = a2tun(sp, NULL); 321 free(sp); 322 return (*remote == SSH_TUNID_ERR ? *remote : tun); 323 } 324 325 if (strcasecmp(s, "any") == 0) 326 return (SSH_TUNID_ANY); 327 328 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 329 if (errstr != NULL) 330 return (SSH_TUNID_ERR); 331 332 return (tun); 333 } 334 335 #define SECONDS 1 336 #define MINUTES (SECONDS * 60) 337 #define HOURS (MINUTES * 60) 338 #define DAYS (HOURS * 24) 339 #define WEEKS (DAYS * 7) 340 341 /* 342 * Convert a time string into seconds; format is 343 * a sequence of: 344 * time[qualifier] 345 * 346 * Valid time qualifiers are: 347 * <none> seconds 348 * s|S seconds 349 * m|M minutes 350 * h|H hours 351 * d|D days 352 * w|W weeks 353 * 354 * Examples: 355 * 90m 90 minutes 356 * 1h30m 90 minutes 357 * 2d 2 days 358 * 1w 1 week 359 * 360 * Return -1 if time string is invalid. 361 */ 362 long 363 convtime(const char *s) 364 { 365 long total, secs, multiplier = 1; 366 const char *p; 367 char *endp; 368 369 errno = 0; 370 total = 0; 371 p = s; 372 373 if (p == NULL || *p == '\0') 374 return -1; 375 376 while (*p) { 377 secs = strtol(p, &endp, 10); 378 if (p == endp || 379 (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) || 380 secs < 0) 381 return -1; 382 383 switch (*endp++) { 384 case '\0': 385 endp--; 386 break; 387 case 's': 388 case 'S': 389 break; 390 case 'm': 391 case 'M': 392 multiplier = MINUTES; 393 break; 394 case 'h': 395 case 'H': 396 multiplier = HOURS; 397 break; 398 case 'd': 399 case 'D': 400 multiplier = DAYS; 401 break; 402 case 'w': 403 case 'W': 404 multiplier = WEEKS; 405 break; 406 default: 407 return -1; 408 } 409 if (secs >= LONG_MAX / multiplier) 410 return -1; 411 secs *= multiplier; 412 if (total >= LONG_MAX - secs) 413 return -1; 414 total += secs; 415 if (total < 0) 416 return -1; 417 p = endp; 418 } 419 420 return total; 421 } 422 423 /* 424 * Returns a standardized host+port identifier string. 425 * Caller must free returned string. 426 */ 427 char * 428 put_host_port(const char *host, u_short port) 429 { 430 char *hoststr; 431 432 if (port == 0 || port == SSH_DEFAULT_PORT) 433 return(xstrdup(host)); 434 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0) 435 fatal("put_host_port: asprintf: %s", strerror(errno)); 436 debug3("put_host_port: %s", hoststr); 437 return hoststr; 438 } 439 440 /* 441 * Search for next delimiter between hostnames/addresses and ports. 442 * Argument may be modified (for termination). 443 * Returns *cp if parsing succeeds. 444 * *cp is set to the start of the next field, if one was found. 445 * The delimiter char, if present, is stored in delim. 446 * If this is the last field, *cp is set to NULL. 447 */ 448 static char * 449 hpdelim2(char **cp, char *delim) 450 { 451 char *s, *old; 452 453 if (cp == NULL || *cp == NULL) 454 return NULL; 455 456 old = s = *cp; 457 if (*s == '[') { 458 if ((s = strchr(s, ']')) == NULL) 459 return NULL; 460 else 461 s++; 462 } else if ((s = strpbrk(s, ":/")) == NULL) 463 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 464 465 switch (*s) { 466 case '\0': 467 *cp = NULL; /* no more fields*/ 468 break; 469 470 case ':': 471 case '/': 472 if (delim != NULL) 473 *delim = *s; 474 *s = '\0'; /* terminate */ 475 *cp = s + 1; 476 break; 477 478 default: 479 return NULL; 480 } 481 482 return old; 483 } 484 485 char * 486 hpdelim(char **cp) 487 { 488 return hpdelim2(cp, NULL); 489 } 490 491 char * 492 cleanhostname(char *host) 493 { 494 if (*host == '[' && host[strlen(host) - 1] == ']') { 495 host[strlen(host) - 1] = '\0'; 496 return (host + 1); 497 } else 498 return host; 499 } 500 501 char * 502 colon(char *cp) 503 { 504 int flag = 0; 505 506 if (*cp == ':') /* Leading colon is part of file name. */ 507 return NULL; 508 if (*cp == '[') 509 flag = 1; 510 511 for (; *cp; ++cp) { 512 if (*cp == '@' && *(cp+1) == '[') 513 flag = 1; 514 if (*cp == ']' && *(cp+1) == ':' && flag) 515 return (cp+1); 516 if (*cp == ':' && !flag) 517 return (cp); 518 if (*cp == '/') 519 return NULL; 520 } 521 return NULL; 522 } 523 524 /* 525 * Parse a [user@]host:[path] string. 526 * Caller must free returned user, host and path. 527 * Any of the pointer return arguments may be NULL (useful for syntax checking). 528 * If user was not specified then *userp will be set to NULL. 529 * If host was not specified then *hostp will be set to NULL. 530 * If path was not specified then *pathp will be set to ".". 531 * Returns 0 on success, -1 on failure. 532 */ 533 int 534 parse_user_host_path(const char *s, char **userp, char **hostp, 535 const char **pathp) 536 { 537 char *user = NULL, *host = NULL, *path = NULL; 538 char *tmp, *sdup; 539 int ret = -1; 540 541 if (userp != NULL) 542 *userp = NULL; 543 if (hostp != NULL) 544 *hostp = NULL; 545 if (pathp != NULL) 546 *pathp = NULL; 547 548 sdup = xstrdup(s); 549 550 /* Check for remote syntax: [user@]host:[path] */ 551 if ((tmp = colon(sdup)) == NULL) 552 goto out; 553 554 /* Extract optional path */ 555 *tmp++ = '\0'; 556 if (*tmp == '\0') 557 tmp = __UNCONST("."); 558 path = xstrdup(tmp); 559 560 /* Extract optional user and mandatory host */ 561 tmp = strrchr(sdup, '@'); 562 if (tmp != NULL) { 563 *tmp++ = '\0'; 564 host = xstrdup(cleanhostname(tmp)); 565 if (*sdup != '\0') 566 user = xstrdup(sdup); 567 } else { 568 host = xstrdup(cleanhostname(sdup)); 569 user = NULL; 570 } 571 572 /* Success */ 573 if (userp != NULL) { 574 *userp = user; 575 user = NULL; 576 } 577 if (hostp != NULL) { 578 *hostp = host; 579 host = NULL; 580 } 581 if (pathp != NULL) { 582 *pathp = path; 583 path = NULL; 584 } 585 ret = 0; 586 out: 587 free(sdup); 588 free(user); 589 free(host); 590 free(path); 591 return ret; 592 } 593 594 /* 595 * Parse a [user@]host[:port] string. 596 * Caller must free returned user and host. 597 * Any of the pointer return arguments may be NULL (useful for syntax checking). 598 * If user was not specified then *userp will be set to NULL. 599 * If port was not specified then *portp will be -1. 600 * Returns 0 on success, -1 on failure. 601 */ 602 int 603 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 604 { 605 char *sdup, *cp, *tmp; 606 char *user = NULL, *host = NULL; 607 int port = -1, ret = -1; 608 609 if (userp != NULL) 610 *userp = NULL; 611 if (hostp != NULL) 612 *hostp = NULL; 613 if (portp != NULL) 614 *portp = -1; 615 616 if ((sdup = tmp = strdup(s)) == NULL) 617 return -1; 618 /* Extract optional username */ 619 if ((cp = strrchr(tmp, '@')) != NULL) { 620 *cp = '\0'; 621 if (*tmp == '\0') 622 goto out; 623 if ((user = strdup(tmp)) == NULL) 624 goto out; 625 tmp = cp + 1; 626 } 627 /* Extract mandatory hostname */ 628 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 629 goto out; 630 host = xstrdup(cleanhostname(cp)); 631 /* Convert and verify optional port */ 632 if (tmp != NULL && *tmp != '\0') { 633 if ((port = a2port(tmp)) <= 0) 634 goto out; 635 } 636 /* Success */ 637 if (userp != NULL) { 638 *userp = user; 639 user = NULL; 640 } 641 if (hostp != NULL) { 642 *hostp = host; 643 host = NULL; 644 } 645 if (portp != NULL) 646 *portp = port; 647 ret = 0; 648 out: 649 free(sdup); 650 free(user); 651 free(host); 652 return ret; 653 } 654 655 /* 656 * Converts a two-byte hex string to decimal. 657 * Returns the decimal value or -1 for invalid input. 658 */ 659 static int 660 hexchar(const char *s) 661 { 662 unsigned char result[2]; 663 int i; 664 665 for (i = 0; i < 2; i++) { 666 if (s[i] >= '0' && s[i] <= '9') 667 result[i] = (unsigned char)(s[i] - '0'); 668 else if (s[i] >= 'a' && s[i] <= 'f') 669 result[i] = (unsigned char)(s[i] - 'a') + 10; 670 else if (s[i] >= 'A' && s[i] <= 'F') 671 result[i] = (unsigned char)(s[i] - 'A') + 10; 672 else 673 return -1; 674 } 675 return (result[0] << 4) | result[1]; 676 } 677 678 /* 679 * Decode an url-encoded string. 680 * Returns a newly allocated string on success or NULL on failure. 681 */ 682 static char * 683 urldecode(const char *src) 684 { 685 char *ret, *dst; 686 int ch; 687 688 ret = xmalloc(strlen(src) + 1); 689 for (dst = ret; *src != '\0'; src++) { 690 switch (*src) { 691 case '+': 692 *dst++ = ' '; 693 break; 694 case '%': 695 if (!isxdigit((unsigned char)src[1]) || 696 !isxdigit((unsigned char)src[2]) || 697 (ch = hexchar(src + 1)) == -1) { 698 free(ret); 699 return NULL; 700 } 701 *dst++ = ch; 702 src += 2; 703 break; 704 default: 705 *dst++ = *src; 706 break; 707 } 708 } 709 *dst = '\0'; 710 711 return ret; 712 } 713 714 /* 715 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 716 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 717 * Either user or path may be url-encoded (but not host or port). 718 * Caller must free returned user, host and path. 719 * Any of the pointer return arguments may be NULL (useful for syntax checking) 720 * but the scheme must always be specified. 721 * If user was not specified then *userp will be set to NULL. 722 * If port was not specified then *portp will be -1. 723 * If path was not specified then *pathp will be set to NULL. 724 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 725 */ 726 int 727 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 728 int *portp, const char **pathp) 729 { 730 char *uridup, *cp, *tmp, ch; 731 char *user = NULL, *host = NULL, *path = NULL; 732 int port = -1, ret = -1; 733 size_t len; 734 735 len = strlen(scheme); 736 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 737 return 1; 738 uri += len + 3; 739 740 if (userp != NULL) 741 *userp = NULL; 742 if (hostp != NULL) 743 *hostp = NULL; 744 if (portp != NULL) 745 *portp = -1; 746 if (pathp != NULL) 747 *pathp = NULL; 748 749 uridup = tmp = xstrdup(uri); 750 751 /* Extract optional ssh-info (username + connection params) */ 752 if ((cp = strchr(tmp, '@')) != NULL) { 753 char *delim; 754 755 *cp = '\0'; 756 /* Extract username and connection params */ 757 if ((delim = strchr(tmp, ';')) != NULL) { 758 /* Just ignore connection params for now */ 759 *delim = '\0'; 760 } 761 if (*tmp == '\0') { 762 /* Empty username */ 763 goto out; 764 } 765 if ((user = urldecode(tmp)) == NULL) 766 goto out; 767 tmp = cp + 1; 768 } 769 770 /* Extract mandatory hostname */ 771 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 772 goto out; 773 host = xstrdup(cleanhostname(cp)); 774 if (!valid_domain(host, 0, NULL)) 775 goto out; 776 777 if (tmp != NULL && *tmp != '\0') { 778 if (ch == ':') { 779 /* Convert and verify port. */ 780 if ((cp = strchr(tmp, '/')) != NULL) 781 *cp = '\0'; 782 if ((port = a2port(tmp)) <= 0) 783 goto out; 784 tmp = cp ? cp + 1 : NULL; 785 } 786 if (tmp != NULL && *tmp != '\0') { 787 /* Extract optional path */ 788 if ((path = urldecode(tmp)) == NULL) 789 goto out; 790 } 791 } 792 793 /* Success */ 794 if (userp != NULL) { 795 *userp = user; 796 user = NULL; 797 } 798 if (hostp != NULL) { 799 *hostp = host; 800 host = NULL; 801 } 802 if (portp != NULL) 803 *portp = port; 804 if (pathp != NULL) { 805 *pathp = path; 806 path = NULL; 807 } 808 ret = 0; 809 out: 810 free(uridup); 811 free(user); 812 free(host); 813 free(path); 814 return ret; 815 } 816 817 /* function to assist building execv() arguments */ 818 void 819 addargs(arglist *args, const char *fmt, ...) 820 { 821 va_list ap; 822 char *cp; 823 u_int nalloc; 824 int r; 825 826 va_start(ap, fmt); 827 r = vasprintf(&cp, fmt, ap); 828 va_end(ap); 829 if (r == -1) 830 fatal("addargs: argument too long"); 831 832 nalloc = args->nalloc; 833 if (args->list == NULL) { 834 nalloc = 32; 835 args->num = 0; 836 } else if (args->num+2 >= nalloc) 837 nalloc *= 2; 838 839 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *)); 840 args->nalloc = nalloc; 841 args->list[args->num++] = cp; 842 args->list[args->num] = NULL; 843 } 844 845 void 846 replacearg(arglist *args, u_int which, const char *fmt, ...) 847 { 848 va_list ap; 849 char *cp; 850 int r; 851 852 va_start(ap, fmt); 853 r = vasprintf(&cp, fmt, ap); 854 va_end(ap); 855 if (r == -1) 856 fatal("replacearg: argument too long"); 857 858 if (which >= args->num) 859 fatal("replacearg: tried to replace invalid arg %d >= %d", 860 which, args->num); 861 free(args->list[which]); 862 args->list[which] = cp; 863 } 864 865 void 866 freeargs(arglist *args) 867 { 868 u_int i; 869 870 if (args->list != NULL) { 871 for (i = 0; i < args->num; i++) 872 free(args->list[i]); 873 free(args->list); 874 args->nalloc = args->num = 0; 875 args->list = NULL; 876 } 877 } 878 879 /* 880 * Expands tildes in the file name. Returns data allocated by xmalloc. 881 * Warning: this calls getpw*. 882 */ 883 char * 884 tilde_expand_filename(const char *filename, uid_t uid) 885 { 886 const char *path, *sep; 887 char user[128], *ret, *homedir; 888 struct passwd *pw; 889 u_int len, slash; 890 891 if (*filename != '~') 892 return (xstrdup(filename)); 893 filename++; 894 895 path = strchr(filename, '/'); 896 if (path != NULL && path > filename) { /* ~user/path */ 897 slash = path - filename; 898 if (slash > sizeof(user) - 1) 899 fatal("tilde_expand_filename: ~username too long"); 900 memcpy(user, filename, slash); 901 user[slash] = '\0'; 902 if ((pw = getpwnam(user)) == NULL) 903 fatal("tilde_expand_filename: No such user %s", user); 904 homedir = pw->pw_dir; 905 } else { 906 if ((pw = getpwuid(uid)) == NULL) /* ~/path */ 907 fatal("tilde_expand_filename: No such uid %ld", 908 (long)uid); 909 homedir = pw->pw_dir; 910 } 911 912 /* Make sure directory has a trailing '/' */ 913 len = strlen(homedir); 914 if (len == 0 || homedir[len - 1] != '/') 915 sep = "/"; 916 else 917 sep = ""; 918 919 /* Skip leading '/' from specified path */ 920 if (path != NULL) 921 filename = path + 1; 922 923 if (xasprintf(&ret, "%s%s%s", homedir, sep, filename) >= PATH_MAX) 924 fatal("tilde_expand_filename: Path too long"); 925 926 return (ret); 927 } 928 929 /* 930 * Expand a string with a set of %[char] escapes. A number of escapes may be 931 * specified as (char *escape_chars, char *replacement) pairs. The list must 932 * be terminated by a NULL escape_char. Returns replaced string in memory 933 * allocated by xmalloc. 934 */ 935 char * 936 percent_expand(const char *string, ...) 937 { 938 #define EXPAND_MAX_KEYS 16 939 u_int num_keys, i, j; 940 struct { 941 const char *key; 942 const char *repl; 943 } keys[EXPAND_MAX_KEYS]; 944 char buf[4096]; 945 va_list ap; 946 947 /* Gather keys */ 948 va_start(ap, string); 949 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 950 keys[num_keys].key = va_arg(ap, char *); 951 if (keys[num_keys].key == NULL) 952 break; 953 keys[num_keys].repl = va_arg(ap, char *); 954 if (keys[num_keys].repl == NULL) 955 fatal("%s: NULL replacement", __func__); 956 } 957 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 958 fatal("%s: too many keys", __func__); 959 va_end(ap); 960 961 /* Expand string */ 962 *buf = '\0'; 963 for (i = 0; *string != '\0'; string++) { 964 if (*string != '%') { 965 append: 966 buf[i++] = *string; 967 if (i >= sizeof(buf)) 968 fatal("%s: string too long", __func__); 969 buf[i] = '\0'; 970 continue; 971 } 972 string++; 973 /* %% case */ 974 if (*string == '%') 975 goto append; 976 if (*string == '\0') 977 fatal("%s: invalid format", __func__); 978 for (j = 0; j < num_keys; j++) { 979 if (strchr(keys[j].key, *string) != NULL) { 980 i = strlcat(buf, keys[j].repl, sizeof(buf)); 981 if (i >= sizeof(buf)) 982 fatal("%s: string too long", __func__); 983 break; 984 } 985 } 986 if (j >= num_keys) 987 fatal("%s: unknown key %%%c", __func__, *string); 988 } 989 return (xstrdup(buf)); 990 #undef EXPAND_MAX_KEYS 991 } 992 993 /* 994 * Read an entire line from a public key file into a static buffer, discarding 995 * lines that exceed the buffer size. Returns 0 on success, -1 on failure. 996 */ 997 int 998 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz, 999 u_long *lineno) 1000 { 1001 while (fgets(buf, bufsz, f) != NULL) { 1002 if (buf[0] == '\0') 1003 continue; 1004 (*lineno)++; 1005 if (buf[strlen(buf) - 1] == '\n' || feof(f)) { 1006 return 0; 1007 } else { 1008 debug("%s: %s line %lu exceeds size limit", __func__, 1009 filename, *lineno); 1010 /* discard remainder of line */ 1011 while (fgetc(f) != '\n' && !feof(f)) 1012 ; /* nothing */ 1013 } 1014 } 1015 return -1; 1016 } 1017 1018 int 1019 tun_open(int tun, int mode, char **ifname) 1020 { 1021 struct ifreq ifr; 1022 char name[100]; 1023 int fd = -1, sock; 1024 const char *tunbase = "tun"; 1025 1026 if (ifname != NULL) 1027 *ifname = NULL; 1028 1029 if (mode == SSH_TUNMODE_ETHERNET) 1030 tunbase = "tap"; 1031 1032 /* Open the tunnel device */ 1033 if (tun <= SSH_TUNID_MAX) { 1034 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1035 fd = open(name, O_RDWR); 1036 } else if (tun == SSH_TUNID_ANY) { 1037 for (tun = 100; tun >= 0; tun--) { 1038 snprintf(name, sizeof(name), "/dev/%s%d", 1039 tunbase, tun); 1040 if ((fd = open(name, O_RDWR)) >= 0) 1041 break; 1042 } 1043 } else { 1044 debug("%s: invalid tunnel %u", __func__, tun); 1045 return -1; 1046 } 1047 1048 if (fd < 0) { 1049 debug("%s: %s open: %s", __func__, name, strerror(errno)); 1050 return -1; 1051 } 1052 1053 1054 #ifdef TUNSIFHEAD 1055 /* Turn on tunnel headers */ 1056 int flag = 1; 1057 if (mode != SSH_TUNMODE_ETHERNET && 1058 ioctl(fd, TUNSIFHEAD, &flag) == -1) { 1059 debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd, 1060 strerror(errno)); 1061 close(fd); 1062 return -1; 1063 } 1064 #endif 1065 1066 debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd); 1067 /* Bring interface up if it is not already */ 1068 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1069 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1070 goto failed; 1071 1072 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1073 debug("%s: get interface %s flags: %s", __func__, 1074 ifr.ifr_name, strerror(errno)); 1075 goto failed; 1076 } 1077 1078 if (!(ifr.ifr_flags & IFF_UP)) { 1079 ifr.ifr_flags |= IFF_UP; 1080 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1081 debug("%s: activate interface %s: %s", __func__, 1082 ifr.ifr_name, strerror(errno)); 1083 goto failed; 1084 } 1085 } 1086 1087 if (ifname != NULL) 1088 *ifname = xstrdup(ifr.ifr_name); 1089 1090 close(sock); 1091 return fd; 1092 1093 failed: 1094 if (fd >= 0) 1095 close(fd); 1096 if (sock >= 0) 1097 close(sock); 1098 debug("%s: failed to set %s mode %d: %s", __func__, ifr.ifr_name, 1099 mode, strerror(errno)); 1100 return -1; 1101 } 1102 1103 void 1104 sanitise_stdfd(void) 1105 { 1106 int nullfd, dupfd; 1107 1108 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1109 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1110 strerror(errno)); 1111 exit(1); 1112 } 1113 while (++dupfd <= STDERR_FILENO) { 1114 /* Only populate closed fds. */ 1115 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1116 if (dup2(nullfd, dupfd) == -1) { 1117 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1118 exit(1); 1119 } 1120 } 1121 } 1122 if (nullfd > STDERR_FILENO) 1123 close(nullfd); 1124 } 1125 1126 char * 1127 tohex(const void *vp, size_t l) 1128 { 1129 const u_char *p = (const u_char *)vp; 1130 char b[3], *r; 1131 size_t i, hl; 1132 1133 if (l > 65536) 1134 return xstrdup("tohex: length > 65536"); 1135 1136 hl = l * 2 + 1; 1137 r = xcalloc(1, hl); 1138 for (i = 0; i < l; i++) { 1139 snprintf(b, sizeof(b), "%02x", p[i]); 1140 strlcat(r, b, hl); 1141 } 1142 return (r); 1143 } 1144 1145 u_int64_t 1146 get_u64(const void *vp) 1147 { 1148 const u_char *p = (const u_char *)vp; 1149 u_int64_t v; 1150 1151 v = (u_int64_t)p[0] << 56; 1152 v |= (u_int64_t)p[1] << 48; 1153 v |= (u_int64_t)p[2] << 40; 1154 v |= (u_int64_t)p[3] << 32; 1155 v |= (u_int64_t)p[4] << 24; 1156 v |= (u_int64_t)p[5] << 16; 1157 v |= (u_int64_t)p[6] << 8; 1158 v |= (u_int64_t)p[7]; 1159 1160 return (v); 1161 } 1162 1163 u_int32_t 1164 get_u32(const void *vp) 1165 { 1166 const u_char *p = (const u_char *)vp; 1167 u_int32_t v; 1168 1169 v = (u_int32_t)p[0] << 24; 1170 v |= (u_int32_t)p[1] << 16; 1171 v |= (u_int32_t)p[2] << 8; 1172 v |= (u_int32_t)p[3]; 1173 1174 return (v); 1175 } 1176 1177 u_int32_t 1178 get_u32_le(const void *vp) 1179 { 1180 const u_char *p = (const u_char *)vp; 1181 u_int32_t v; 1182 1183 v = (u_int32_t)p[0]; 1184 v |= (u_int32_t)p[1] << 8; 1185 v |= (u_int32_t)p[2] << 16; 1186 v |= (u_int32_t)p[3] << 24; 1187 1188 return (v); 1189 } 1190 1191 u_int16_t 1192 get_u16(const void *vp) 1193 { 1194 const u_char *p = (const u_char *)vp; 1195 u_int16_t v; 1196 1197 v = (u_int16_t)p[0] << 8; 1198 v |= (u_int16_t)p[1]; 1199 1200 return (v); 1201 } 1202 1203 void 1204 put_u64(void *vp, u_int64_t v) 1205 { 1206 u_char *p = (u_char *)vp; 1207 1208 p[0] = (u_char)(v >> 56) & 0xff; 1209 p[1] = (u_char)(v >> 48) & 0xff; 1210 p[2] = (u_char)(v >> 40) & 0xff; 1211 p[3] = (u_char)(v >> 32) & 0xff; 1212 p[4] = (u_char)(v >> 24) & 0xff; 1213 p[5] = (u_char)(v >> 16) & 0xff; 1214 p[6] = (u_char)(v >> 8) & 0xff; 1215 p[7] = (u_char)v & 0xff; 1216 } 1217 1218 void 1219 put_u32(void *vp, u_int32_t v) 1220 { 1221 u_char *p = (u_char *)vp; 1222 1223 p[0] = (u_char)(v >> 24) & 0xff; 1224 p[1] = (u_char)(v >> 16) & 0xff; 1225 p[2] = (u_char)(v >> 8) & 0xff; 1226 p[3] = (u_char)v & 0xff; 1227 } 1228 1229 void 1230 put_u32_le(void *vp, u_int32_t v) 1231 { 1232 u_char *p = (u_char *)vp; 1233 1234 p[0] = (u_char)v & 0xff; 1235 p[1] = (u_char)(v >> 8) & 0xff; 1236 p[2] = (u_char)(v >> 16) & 0xff; 1237 p[3] = (u_char)(v >> 24) & 0xff; 1238 } 1239 1240 void 1241 put_u16(void *vp, u_int16_t v) 1242 { 1243 u_char *p = (u_char *)vp; 1244 1245 p[0] = (u_char)(v >> 8) & 0xff; 1246 p[1] = (u_char)v & 0xff; 1247 } 1248 1249 void 1250 ms_subtract_diff(struct timeval *start, int *ms) 1251 { 1252 struct timeval diff, finish; 1253 1254 monotime_tv(&finish); 1255 timersub(&finish, start, &diff); 1256 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1257 } 1258 1259 void 1260 ms_to_timeval(struct timeval *tv, int ms) 1261 { 1262 if (ms < 0) 1263 ms = 0; 1264 tv->tv_sec = ms / 1000; 1265 tv->tv_usec = (ms % 1000) * 1000; 1266 } 1267 1268 void 1269 monotime_ts(struct timespec *ts) 1270 { 1271 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1272 fatal("clock_gettime: %s", strerror(errno)); 1273 } 1274 1275 void 1276 monotime_tv(struct timeval *tv) 1277 { 1278 struct timespec ts; 1279 1280 monotime_ts(&ts); 1281 tv->tv_sec = ts.tv_sec; 1282 tv->tv_usec = ts.tv_nsec / 1000; 1283 } 1284 1285 time_t 1286 monotime(void) 1287 { 1288 struct timespec ts; 1289 1290 monotime_ts(&ts); 1291 return (ts.tv_sec); 1292 } 1293 1294 double 1295 monotime_double(void) 1296 { 1297 struct timespec ts; 1298 1299 monotime_ts(&ts); 1300 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1301 } 1302 1303 void 1304 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1305 { 1306 bw->buflen = buflen; 1307 bw->rate = kbps; 1308 bw->thresh = bw->rate; 1309 bw->lamt = 0; 1310 timerclear(&bw->bwstart); 1311 timerclear(&bw->bwend); 1312 } 1313 1314 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1315 void 1316 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1317 { 1318 u_int64_t waitlen; 1319 struct timespec ts, rm; 1320 1321 if (!timerisset(&bw->bwstart)) { 1322 monotime_tv(&bw->bwstart); 1323 return; 1324 } 1325 1326 bw->lamt += read_len; 1327 if (bw->lamt < bw->thresh) 1328 return; 1329 1330 monotime_tv(&bw->bwend); 1331 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1332 if (!timerisset(&bw->bwend)) 1333 return; 1334 1335 bw->lamt *= 8; 1336 waitlen = (double)1000000L * bw->lamt / bw->rate; 1337 1338 bw->bwstart.tv_sec = waitlen / 1000000L; 1339 bw->bwstart.tv_usec = waitlen % 1000000L; 1340 1341 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1342 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1343 1344 /* Adjust the wait time */ 1345 if (bw->bwend.tv_sec) { 1346 bw->thresh /= 2; 1347 if (bw->thresh < bw->buflen / 4) 1348 bw->thresh = bw->buflen / 4; 1349 } else if (bw->bwend.tv_usec < 10000) { 1350 bw->thresh *= 2; 1351 if (bw->thresh > bw->buflen * 8) 1352 bw->thresh = bw->buflen * 8; 1353 } 1354 1355 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1356 while (nanosleep(&ts, &rm) == -1) { 1357 if (errno != EINTR) 1358 break; 1359 ts = rm; 1360 } 1361 } 1362 1363 bw->lamt = 0; 1364 monotime_tv(&bw->bwstart); 1365 } 1366 1367 /* Make a template filename for mk[sd]temp() */ 1368 void 1369 mktemp_proto(char *s, size_t len) 1370 { 1371 const char *tmpdir; 1372 int r; 1373 1374 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1375 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1376 if (r > 0 && (size_t)r < len) 1377 return; 1378 } 1379 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1380 if (r < 0 || (size_t)r >= len) 1381 fatal("%s: template string too short", __func__); 1382 } 1383 1384 static const struct { 1385 const char *name; 1386 int value; 1387 } ipqos[] = { 1388 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1389 { "af11", IPTOS_DSCP_AF11 }, 1390 { "af12", IPTOS_DSCP_AF12 }, 1391 { "af13", IPTOS_DSCP_AF13 }, 1392 { "af21", IPTOS_DSCP_AF21 }, 1393 { "af22", IPTOS_DSCP_AF22 }, 1394 { "af23", IPTOS_DSCP_AF23 }, 1395 { "af31", IPTOS_DSCP_AF31 }, 1396 { "af32", IPTOS_DSCP_AF32 }, 1397 { "af33", IPTOS_DSCP_AF33 }, 1398 { "af41", IPTOS_DSCP_AF41 }, 1399 { "af42", IPTOS_DSCP_AF42 }, 1400 { "af43", IPTOS_DSCP_AF43 }, 1401 { "cs0", IPTOS_DSCP_CS0 }, 1402 { "cs1", IPTOS_DSCP_CS1 }, 1403 { "cs2", IPTOS_DSCP_CS2 }, 1404 { "cs3", IPTOS_DSCP_CS3 }, 1405 { "cs4", IPTOS_DSCP_CS4 }, 1406 { "cs5", IPTOS_DSCP_CS5 }, 1407 { "cs6", IPTOS_DSCP_CS6 }, 1408 { "cs7", IPTOS_DSCP_CS7 }, 1409 { "ef", IPTOS_DSCP_EF }, 1410 { "lowdelay", IPTOS_LOWDELAY }, 1411 { "throughput", IPTOS_THROUGHPUT }, 1412 { "reliability", IPTOS_RELIABILITY }, 1413 { NULL, -1 } 1414 }; 1415 1416 int 1417 parse_ipqos(const char *cp) 1418 { 1419 u_int i; 1420 char *ep; 1421 long val; 1422 1423 if (cp == NULL) 1424 return -1; 1425 for (i = 0; ipqos[i].name != NULL; i++) { 1426 if (strcasecmp(cp, ipqos[i].name) == 0) 1427 return ipqos[i].value; 1428 } 1429 /* Try parsing as an integer */ 1430 val = strtol(cp, &ep, 0); 1431 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1432 return -1; 1433 return val; 1434 } 1435 1436 const char * 1437 iptos2str(int iptos) 1438 { 1439 int i; 1440 static char iptos_str[sizeof "0xff"]; 1441 1442 for (i = 0; ipqos[i].name != NULL; i++) { 1443 if (ipqos[i].value == iptos) 1444 return ipqos[i].name; 1445 } 1446 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1447 return iptos_str; 1448 } 1449 1450 void 1451 lowercase(char *s) 1452 { 1453 for (; *s; s++) 1454 *s = tolower((u_char)*s); 1455 } 1456 1457 int 1458 unix_listener(const char *path, int backlog, int unlink_first) 1459 { 1460 struct sockaddr_un sunaddr; 1461 int saved_errno, sock; 1462 1463 memset(&sunaddr, 0, sizeof(sunaddr)); 1464 sunaddr.sun_family = AF_UNIX; 1465 if (strlcpy(sunaddr.sun_path, path, 1466 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1467 error("%s: path \"%s\" too long for Unix domain socket", 1468 __func__, path); 1469 errno = ENAMETOOLONG; 1470 return -1; 1471 } 1472 1473 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1474 if (sock < 0) { 1475 saved_errno = errno; 1476 error("%s: socket: %.100s", __func__, strerror(errno)); 1477 errno = saved_errno; 1478 return -1; 1479 } 1480 if (unlink_first == 1) { 1481 if (unlink(path) != 0 && errno != ENOENT) 1482 error("unlink(%s): %.100s", path, strerror(errno)); 1483 } 1484 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) { 1485 saved_errno = errno; 1486 error("%s: cannot bind to path %s: %s", 1487 __func__, path, strerror(errno)); 1488 close(sock); 1489 errno = saved_errno; 1490 return -1; 1491 } 1492 if (listen(sock, backlog) < 0) { 1493 saved_errno = errno; 1494 error("%s: cannot listen on path %s: %s", 1495 __func__, path, strerror(errno)); 1496 close(sock); 1497 unlink(path); 1498 errno = saved_errno; 1499 return -1; 1500 } 1501 return sock; 1502 } 1503 1504 /* 1505 * Compares two strings that maybe be NULL. Returns non-zero if strings 1506 * are both NULL or are identical, returns zero otherwise. 1507 */ 1508 static int 1509 strcmp_maybe_null(const char *a, const char *b) 1510 { 1511 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1512 return 0; 1513 if (a != NULL && strcmp(a, b) != 0) 1514 return 0; 1515 return 1; 1516 } 1517 1518 /* 1519 * Compare two forwards, returning non-zero if they are identical or 1520 * zero otherwise. 1521 */ 1522 int 1523 forward_equals(const struct Forward *a, const struct Forward *b) 1524 { 1525 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1526 return 0; 1527 if (a->listen_port != b->listen_port) 1528 return 0; 1529 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1530 return 0; 1531 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1532 return 0; 1533 if (a->connect_port != b->connect_port) 1534 return 0; 1535 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1536 return 0; 1537 /* allocated_port and handle are not checked */ 1538 return 1; 1539 } 1540 1541 /* returns 1 if bind to specified port by specified user is permitted */ 1542 int 1543 bind_permitted(int port, uid_t uid) 1544 { 1545 if (port < IPPORT_RESERVED && uid != 0) 1546 return 0; 1547 return 1; 1548 } 1549 1550 /* returns 1 if process is already daemonized, 0 otherwise */ 1551 int 1552 daemonized(void) 1553 { 1554 int fd; 1555 1556 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1557 close(fd); 1558 return 0; /* have controlling terminal */ 1559 } 1560 if (getppid() != 1) 1561 return 0; /* parent is not init */ 1562 if (getsid(0) != getpid()) 1563 return 0; /* not session leader */ 1564 debug3("already daemonized"); 1565 return 1; 1566 } 1567 1568 1569 /* 1570 * Splits 's' into an argument vector. Handles quoted string and basic 1571 * escape characters (\\, \", \'). Caller must free the argument vector 1572 * and its members. 1573 */ 1574 int 1575 argv_split(const char *s, int *argcp, char ***argvp) 1576 { 1577 int r = SSH_ERR_INTERNAL_ERROR; 1578 int argc = 0, quote, i, j; 1579 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1580 1581 *argvp = NULL; 1582 *argcp = 0; 1583 1584 for (i = 0; s[i] != '\0'; i++) { 1585 /* Skip leading whitespace */ 1586 if (s[i] == ' ' || s[i] == '\t') 1587 continue; 1588 1589 /* Start of a token */ 1590 quote = 0; 1591 if (s[i] == '\\' && 1592 (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\')) 1593 i++; 1594 else if (s[i] == '\'' || s[i] == '"') 1595 quote = s[i++]; 1596 1597 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1598 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1599 argv[argc] = NULL; 1600 1601 /* Copy the token in, removing escapes */ 1602 for (j = 0; s[i] != '\0'; i++) { 1603 if (s[i] == '\\') { 1604 if (s[i + 1] == '\'' || 1605 s[i + 1] == '\"' || 1606 s[i + 1] == '\\') { 1607 i++; /* Skip '\' */ 1608 arg[j++] = s[i]; 1609 } else { 1610 /* Unrecognised escape */ 1611 arg[j++] = s[i]; 1612 } 1613 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1614 break; /* done */ 1615 else if (quote != 0 && s[i] == quote) 1616 break; /* done */ 1617 else 1618 arg[j++] = s[i]; 1619 } 1620 if (s[i] == '\0') { 1621 if (quote != 0) { 1622 /* Ran out of string looking for close quote */ 1623 r = SSH_ERR_INVALID_FORMAT; 1624 goto out; 1625 } 1626 break; 1627 } 1628 } 1629 /* Success */ 1630 *argcp = argc; 1631 *argvp = argv; 1632 argc = 0; 1633 argv = NULL; 1634 r = 0; 1635 out: 1636 if (argc != 0 && argv != NULL) { 1637 for (i = 0; i < argc; i++) 1638 free(argv[i]); 1639 free(argv); 1640 } 1641 return r; 1642 } 1643 1644 /* 1645 * Reassemble an argument vector into a string, quoting and escaping as 1646 * necessary. Caller must free returned string. 1647 */ 1648 char * 1649 argv_assemble(int argc, char **argv) 1650 { 1651 int i, j, ws, r; 1652 char c, *ret; 1653 struct sshbuf *buf, *arg; 1654 1655 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 1656 fatal("%s: sshbuf_new failed", __func__); 1657 1658 for (i = 0; i < argc; i++) { 1659 ws = 0; 1660 sshbuf_reset(arg); 1661 for (j = 0; argv[i][j] != '\0'; j++) { 1662 r = 0; 1663 c = argv[i][j]; 1664 switch (c) { 1665 case ' ': 1666 case '\t': 1667 ws = 1; 1668 r = sshbuf_put_u8(arg, c); 1669 break; 1670 case '\\': 1671 case '\'': 1672 case '"': 1673 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 1674 break; 1675 /* FALLTHROUGH */ 1676 default: 1677 r = sshbuf_put_u8(arg, c); 1678 break; 1679 } 1680 if (r != 0) 1681 fatal("%s: sshbuf_put_u8: %s", 1682 __func__, ssh_err(r)); 1683 } 1684 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 1685 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 1686 (r = sshbuf_putb(buf, arg)) != 0 || 1687 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 1688 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1689 } 1690 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 1691 fatal("%s: malloc failed", __func__); 1692 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 1693 ret[sshbuf_len(buf)] = '\0'; 1694 sshbuf_free(buf); 1695 sshbuf_free(arg); 1696 return ret; 1697 } 1698 1699 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 1700 int 1701 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 1702 { 1703 int status; 1704 1705 while (waitpid(pid, &status, 0) == -1) { 1706 if (errno != EINTR) { 1707 error("%s: waitpid: %s", tag, strerror(errno)); 1708 return -1; 1709 } 1710 } 1711 if (WIFSIGNALED(status)) { 1712 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 1713 return -1; 1714 } else if (WEXITSTATUS(status) != 0) { 1715 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 1716 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 1717 return -1; 1718 } 1719 return 0; 1720 } 1721 1722 /* 1723 * Check a given path for security. This is defined as all components 1724 * of the path to the file must be owned by either the owner of 1725 * of the file or root and no directories must be group or world writable. 1726 * 1727 * XXX Should any specific check be done for sym links ? 1728 * 1729 * Takes a file name, its stat information (preferably from fstat() to 1730 * avoid races), the uid of the expected owner, their home directory and an 1731 * error buffer plus max size as arguments. 1732 * 1733 * Returns 0 on success and -1 on failure 1734 */ 1735 int 1736 safe_path(const char *name, struct stat *stp, const char *pw_dir, 1737 uid_t uid, char *err, size_t errlen) 1738 { 1739 char buf[PATH_MAX], homedir[PATH_MAX]; 1740 char *cp; 1741 int comparehome = 0; 1742 struct stat st; 1743 1744 if (realpath(name, buf) == NULL) { 1745 snprintf(err, errlen, "realpath %s failed: %s", name, 1746 strerror(errno)); 1747 return -1; 1748 } 1749 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 1750 comparehome = 1; 1751 1752 if (!S_ISREG(stp->st_mode)) { 1753 snprintf(err, errlen, "%s is not a regular file", buf); 1754 return -1; 1755 } 1756 if ((stp->st_uid != 0 && stp->st_uid != uid) || 1757 (stp->st_mode & 022) != 0) { 1758 snprintf(err, errlen, "bad ownership or modes for file %s", 1759 buf); 1760 return -1; 1761 } 1762 1763 /* for each component of the canonical path, walking upwards */ 1764 for (;;) { 1765 if ((cp = dirname(buf)) == NULL) { 1766 snprintf(err, errlen, "dirname() failed"); 1767 return -1; 1768 } 1769 strlcpy(buf, cp, sizeof(buf)); 1770 1771 if (stat(buf, &st) < 0 || 1772 (st.st_uid != 0 && st.st_uid != uid) || 1773 (st.st_mode & 022) != 0) { 1774 snprintf(err, errlen, 1775 "bad ownership or modes for directory %s", buf); 1776 return -1; 1777 } 1778 1779 /* If are past the homedir then we can stop */ 1780 if (comparehome && strcmp(homedir, buf) == 0) 1781 break; 1782 1783 /* 1784 * dirname should always complete with a "/" path, 1785 * but we can be paranoid and check for "." too 1786 */ 1787 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 1788 break; 1789 } 1790 return 0; 1791 } 1792 1793 /* 1794 * Version of safe_path() that accepts an open file descriptor to 1795 * avoid races. 1796 * 1797 * Returns 0 on success and -1 on failure 1798 */ 1799 int 1800 safe_path_fd(int fd, const char *file, struct passwd *pw, 1801 char *err, size_t errlen) 1802 { 1803 struct stat st; 1804 1805 /* check the open file to avoid races */ 1806 if (fstat(fd, &st) < 0) { 1807 snprintf(err, errlen, "cannot stat file %s: %s", 1808 file, strerror(errno)); 1809 return -1; 1810 } 1811 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 1812 } 1813 1814 /* 1815 * Sets the value of the given variable in the environment. If the variable 1816 * already exists, its value is overridden. 1817 */ 1818 void 1819 child_set_env(char ***envp, u_int *envsizep, const char *name, 1820 const char *value) 1821 { 1822 char **env; 1823 u_int envsize; 1824 u_int i, namelen; 1825 1826 if (strchr(name, '=') != NULL) { 1827 error("Invalid environment variable \"%.100s\"", name); 1828 return; 1829 } 1830 1831 /* 1832 * Find the slot where the value should be stored. If the variable 1833 * already exists, we reuse the slot; otherwise we append a new slot 1834 * at the end of the array, expanding if necessary. 1835 */ 1836 env = *envp; 1837 namelen = strlen(name); 1838 for (i = 0; env[i]; i++) 1839 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 1840 break; 1841 if (env[i]) { 1842 /* Reuse the slot. */ 1843 free(env[i]); 1844 } else { 1845 /* New variable. Expand if necessary. */ 1846 envsize = *envsizep; 1847 if (i >= envsize - 1) { 1848 if (envsize >= 1000) 1849 fatal("child_set_env: too many env vars"); 1850 envsize += 50; 1851 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 1852 *envsizep = envsize; 1853 } 1854 /* Need to set the NULL pointer at end of array beyond the new slot. */ 1855 env[i + 1] = NULL; 1856 } 1857 1858 /* Allocate space and format the variable in the appropriate slot. */ 1859 /* XXX xasprintf */ 1860 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 1861 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 1862 } 1863 1864 /* 1865 * Check and optionally lowercase a domain name, also removes trailing '.' 1866 * Returns 1 on success and 0 on failure, storing an error message in errstr. 1867 */ 1868 int 1869 valid_domain(char *name, int makelower, const char **errstr) 1870 { 1871 size_t i, l = strlen(name); 1872 u_char c, last = '\0'; 1873 static char errbuf[256]; 1874 1875 if (l == 0) { 1876 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 1877 goto bad; 1878 } 1879 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 1880 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 1881 "starts with invalid character", name); 1882 goto bad; 1883 } 1884 for (i = 0; i < l; i++) { 1885 c = tolower((u_char)name[i]); 1886 if (makelower) 1887 name[i] = (char)c; 1888 if (last == '.' && c == '.') { 1889 snprintf(errbuf, sizeof(errbuf), "domain name " 1890 "\"%.100s\" contains consecutive separators", name); 1891 goto bad; 1892 } 1893 if (c != '.' && c != '-' && !isalnum(c) && 1894 c != '_') /* technically invalid, but common */ { 1895 snprintf(errbuf, sizeof(errbuf), "domain name " 1896 "\"%.100s\" contains invalid characters", name); 1897 goto bad; 1898 } 1899 last = c; 1900 } 1901 if (name[l - 1] == '.') 1902 name[l - 1] = '\0'; 1903 if (errstr != NULL) 1904 *errstr = NULL; 1905 return 1; 1906 bad: 1907 if (errstr != NULL) 1908 *errstr = errbuf; 1909 return 0; 1910 } 1911 1912 const char * 1913 atoi_err(const char *nptr, int *val) 1914 { 1915 const char *errstr = NULL; 1916 long long num; 1917 1918 if (nptr == NULL || *nptr == '\0') 1919 return "missing"; 1920 num = strtonum(nptr, 0, INT_MAX, &errstr); 1921 if (errstr == NULL) 1922 *val = (int)num; 1923 return errstr; 1924 } 1925 1926 int 1927 parse_absolute_time(const char *s, uint64_t *tp) 1928 { 1929 struct tm tm; 1930 time_t tt; 1931 char buf[32]; 1932 const char *fmt; 1933 1934 *tp = 0; 1935 1936 /* 1937 * POSIX strptime says "The application shall ensure that there 1938 * is white-space or other non-alphanumeric characters between 1939 * any two conversion specifications" so arrange things this way. 1940 */ 1941 switch (strlen(s)) { 1942 case 8: /* YYYYMMDD */ 1943 fmt = "%Y-%m-%d"; 1944 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 1945 break; 1946 case 12: /* YYYYMMDDHHMM */ 1947 fmt = "%Y-%m-%dT%H:%M"; 1948 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 1949 s, s + 4, s + 6, s + 8, s + 10); 1950 break; 1951 case 14: /* YYYYMMDDHHMMSS */ 1952 fmt = "%Y-%m-%dT%H:%M:%S"; 1953 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 1954 s, s + 4, s + 6, s + 8, s + 10, s + 12); 1955 break; 1956 default: 1957 return SSH_ERR_INVALID_FORMAT; 1958 } 1959 1960 memset(&tm, 0, sizeof(tm)); 1961 if (strptime(buf, fmt, &tm) == NULL) 1962 return SSH_ERR_INVALID_FORMAT; 1963 if ((tt = mktime(&tm)) < 0) 1964 return SSH_ERR_INVALID_FORMAT; 1965 /* success */ 1966 *tp = (uint64_t)tt; 1967 return 0; 1968 } 1969 1970 void 1971 format_absolute_time(uint64_t t, char *buf, size_t len) 1972 { 1973 time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */ 1974 struct tm tm; 1975 1976 localtime_r(&tt, &tm); 1977 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 1978 } 1979