1 /* $OpenBSD: misc.c,v 1.109 2017/03/14 00:55:37 dtucker 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/sysctl.h> 33 #include <sys/time.h> 34 #include <sys/un.h> 35 36 #include <limits.h> 37 #include <stdarg.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <time.h> 42 #include <unistd.h> 43 44 #include <netinet/in.h> 45 #include <netinet/in_systm.h> 46 #include <netinet/ip.h> 47 #include <netinet/tcp.h> 48 49 #include <ctype.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <netdb.h> 53 #ifdef HAVE_PATHS_H 54 # include <paths.h> 55 #include <pwd.h> 56 #endif 57 #ifdef SSH_TUN_OPENBSD 58 #include <net/if.h> 59 #endif 60 61 #include "xmalloc.h" 62 #include "misc.h" 63 #include "log.h" 64 #include "ssh.h" 65 66 /* remove newline at end of string */ 67 char * 68 chop(char *s) 69 { 70 char *t = s; 71 while (*t) { 72 if (*t == '\n' || *t == '\r') { 73 *t = '\0'; 74 return s; 75 } 76 t++; 77 } 78 return s; 79 80 } 81 82 /* set/unset filedescriptor to non-blocking */ 83 int 84 set_nonblock(int fd) 85 { 86 int val; 87 88 val = fcntl(fd, F_GETFL); 89 if (val < 0) { 90 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 91 return (-1); 92 } 93 if (val & O_NONBLOCK) { 94 debug3("fd %d is O_NONBLOCK", fd); 95 return (0); 96 } 97 debug2("fd %d setting O_NONBLOCK", fd); 98 val |= O_NONBLOCK; 99 if (fcntl(fd, F_SETFL, val) == -1) { 100 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 101 strerror(errno)); 102 return (-1); 103 } 104 return (0); 105 } 106 107 int 108 unset_nonblock(int fd) 109 { 110 int val; 111 112 val = fcntl(fd, F_GETFL); 113 if (val < 0) { 114 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 115 return (-1); 116 } 117 if (!(val & O_NONBLOCK)) { 118 debug3("fd %d is not O_NONBLOCK", fd); 119 return (0); 120 } 121 debug("fd %d clearing O_NONBLOCK", fd); 122 val &= ~O_NONBLOCK; 123 if (fcntl(fd, F_SETFL, val) == -1) { 124 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 125 fd, strerror(errno)); 126 return (-1); 127 } 128 return (0); 129 } 130 131 const char * 132 ssh_gai_strerror(int gaierr) 133 { 134 if (gaierr == EAI_SYSTEM && errno != 0) 135 return strerror(errno); 136 return gai_strerror(gaierr); 137 } 138 139 /* disable nagle on socket */ 140 void 141 set_nodelay(int fd) 142 { 143 int opt; 144 socklen_t optlen; 145 146 optlen = sizeof opt; 147 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 148 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 149 return; 150 } 151 if (opt == 1) { 152 debug2("fd %d is TCP_NODELAY", fd); 153 return; 154 } 155 opt = 1; 156 debug2("fd %d setting TCP_NODELAY", fd); 157 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 158 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 159 } 160 161 /* Characters considered whitespace in strsep calls. */ 162 #define WHITESPACE " \t\r\n" 163 #define QUOTE "\"" 164 165 /* return next token in configuration line */ 166 char * 167 strdelim(char **s) 168 { 169 char *old; 170 int wspace = 0; 171 172 if (*s == NULL) 173 return NULL; 174 175 old = *s; 176 177 *s = strpbrk(*s, WHITESPACE QUOTE "="); 178 if (*s == NULL) 179 return (old); 180 181 if (*s[0] == '\"') { 182 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 183 /* Find matching quote */ 184 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 185 return (NULL); /* no matching quote */ 186 } else { 187 *s[0] = '\0'; 188 *s += strspn(*s + 1, WHITESPACE) + 1; 189 return (old); 190 } 191 } 192 193 /* Allow only one '=' to be skipped */ 194 if (*s[0] == '=') 195 wspace = 1; 196 *s[0] = '\0'; 197 198 /* Skip any extra whitespace after first token */ 199 *s += strspn(*s + 1, WHITESPACE) + 1; 200 if (*s[0] == '=' && !wspace) 201 *s += strspn(*s + 1, WHITESPACE) + 1; 202 203 return (old); 204 } 205 206 struct passwd * 207 pwcopy(struct passwd *pw) 208 { 209 struct passwd *copy = xcalloc(1, sizeof(*copy)); 210 211 copy->pw_name = xstrdup(pw->pw_name); 212 copy->pw_passwd = xstrdup(pw->pw_passwd); 213 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 214 copy->pw_gecos = xstrdup(pw->pw_gecos); 215 #endif 216 copy->pw_uid = pw->pw_uid; 217 copy->pw_gid = pw->pw_gid; 218 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE 219 copy->pw_expire = pw->pw_expire; 220 #endif 221 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE 222 copy->pw_change = pw->pw_change; 223 #endif 224 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 225 copy->pw_class = xstrdup(pw->pw_class); 226 #endif 227 copy->pw_dir = xstrdup(pw->pw_dir); 228 copy->pw_shell = xstrdup(pw->pw_shell); 229 return copy; 230 } 231 232 /* 233 * Convert ASCII string to TCP/IP port number. 234 * Port must be >=0 and <=65535. 235 * Return -1 if invalid. 236 */ 237 int 238 a2port(const char *s) 239 { 240 long long port; 241 const char *errstr; 242 243 port = strtonum(s, 0, 65535, &errstr); 244 if (errstr != NULL) 245 return -1; 246 return (int)port; 247 } 248 249 int 250 a2tun(const char *s, int *remote) 251 { 252 const char *errstr = NULL; 253 char *sp, *ep; 254 int tun; 255 256 if (remote != NULL) { 257 *remote = SSH_TUNID_ANY; 258 sp = xstrdup(s); 259 if ((ep = strchr(sp, ':')) == NULL) { 260 free(sp); 261 return (a2tun(s, NULL)); 262 } 263 ep[0] = '\0'; ep++; 264 *remote = a2tun(ep, NULL); 265 tun = a2tun(sp, NULL); 266 free(sp); 267 return (*remote == SSH_TUNID_ERR ? *remote : tun); 268 } 269 270 if (strcasecmp(s, "any") == 0) 271 return (SSH_TUNID_ANY); 272 273 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 274 if (errstr != NULL) 275 return (SSH_TUNID_ERR); 276 277 return (tun); 278 } 279 280 #define SECONDS 1 281 #define MINUTES (SECONDS * 60) 282 #define HOURS (MINUTES * 60) 283 #define DAYS (HOURS * 24) 284 #define WEEKS (DAYS * 7) 285 286 /* 287 * Convert a time string into seconds; format is 288 * a sequence of: 289 * time[qualifier] 290 * 291 * Valid time qualifiers are: 292 * <none> seconds 293 * s|S seconds 294 * m|M minutes 295 * h|H hours 296 * d|D days 297 * w|W weeks 298 * 299 * Examples: 300 * 90m 90 minutes 301 * 1h30m 90 minutes 302 * 2d 2 days 303 * 1w 1 week 304 * 305 * Return -1 if time string is invalid. 306 */ 307 long 308 convtime(const char *s) 309 { 310 long total, secs, multiplier = 1; 311 const char *p; 312 char *endp; 313 314 errno = 0; 315 total = 0; 316 p = s; 317 318 if (p == NULL || *p == '\0') 319 return -1; 320 321 while (*p) { 322 secs = strtol(p, &endp, 10); 323 if (p == endp || 324 (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) || 325 secs < 0) 326 return -1; 327 328 switch (*endp++) { 329 case '\0': 330 endp--; 331 break; 332 case 's': 333 case 'S': 334 break; 335 case 'm': 336 case 'M': 337 multiplier = MINUTES; 338 break; 339 case 'h': 340 case 'H': 341 multiplier = HOURS; 342 break; 343 case 'd': 344 case 'D': 345 multiplier = DAYS; 346 break; 347 case 'w': 348 case 'W': 349 multiplier = WEEKS; 350 break; 351 default: 352 return -1; 353 } 354 if (secs >= LONG_MAX / multiplier) 355 return -1; 356 secs *= multiplier; 357 if (total >= LONG_MAX - secs) 358 return -1; 359 total += secs; 360 if (total < 0) 361 return -1; 362 p = endp; 363 } 364 365 return total; 366 } 367 368 /* 369 * Returns a standardized host+port identifier string. 370 * Caller must free returned string. 371 */ 372 char * 373 put_host_port(const char *host, u_short port) 374 { 375 char *hoststr; 376 377 if (port == 0 || port == SSH_DEFAULT_PORT) 378 return(xstrdup(host)); 379 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0) 380 fatal("put_host_port: asprintf: %s", strerror(errno)); 381 debug3("put_host_port: %s", hoststr); 382 return hoststr; 383 } 384 385 /* 386 * Search for next delimiter between hostnames/addresses and ports. 387 * Argument may be modified (for termination). 388 * Returns *cp if parsing succeeds. 389 * *cp is set to the start of the next delimiter, if one was found. 390 * If this is the last field, *cp is set to NULL. 391 */ 392 char * 393 hpdelim(char **cp) 394 { 395 char *s, *old; 396 397 if (cp == NULL || *cp == NULL) 398 return NULL; 399 400 old = s = *cp; 401 if (*s == '[') { 402 if ((s = strchr(s, ']')) == NULL) 403 return NULL; 404 else 405 s++; 406 } else if ((s = strpbrk(s, ":/")) == NULL) 407 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 408 409 switch (*s) { 410 case '\0': 411 *cp = NULL; /* no more fields*/ 412 break; 413 414 case ':': 415 case '/': 416 *s = '\0'; /* terminate */ 417 *cp = s + 1; 418 break; 419 420 default: 421 return NULL; 422 } 423 424 return old; 425 } 426 427 char * 428 cleanhostname(char *host) 429 { 430 if (*host == '[' && host[strlen(host) - 1] == ']') { 431 host[strlen(host) - 1] = '\0'; 432 return (host + 1); 433 } else 434 return host; 435 } 436 437 char * 438 colon(char *cp) 439 { 440 int flag = 0; 441 442 if (*cp == ':') /* Leading colon is part of file name. */ 443 return NULL; 444 if (*cp == '[') 445 flag = 1; 446 447 for (; *cp; ++cp) { 448 if (*cp == '@' && *(cp+1) == '[') 449 flag = 1; 450 if (*cp == ']' && *(cp+1) == ':' && flag) 451 return (cp+1); 452 if (*cp == ':' && !flag) 453 return (cp); 454 if (*cp == '/') 455 return NULL; 456 } 457 return NULL; 458 } 459 460 /* 461 * Parse a [user@]host[:port] string. 462 * Caller must free returned user and host. 463 * Any of the pointer return arguments may be NULL (useful for syntax checking). 464 * If user was not specified then *userp will be set to NULL. 465 * If port was not specified then *portp will be -1. 466 * Returns 0 on success, -1 on failure. 467 */ 468 int 469 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 470 { 471 char *sdup, *cp, *tmp; 472 char *user = NULL, *host = NULL; 473 int port = -1, ret = -1; 474 475 if (userp != NULL) 476 *userp = NULL; 477 if (hostp != NULL) 478 *hostp = NULL; 479 if (portp != NULL) 480 *portp = -1; 481 482 if ((sdup = tmp = strdup(s)) == NULL) 483 return -1; 484 /* Extract optional username */ 485 if ((cp = strchr(tmp, '@')) != NULL) { 486 *cp = '\0'; 487 if (*tmp == '\0') 488 goto out; 489 if ((user = strdup(tmp)) == NULL) 490 goto out; 491 tmp = cp + 1; 492 } 493 /* Extract mandatory hostname */ 494 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 495 goto out; 496 host = xstrdup(cleanhostname(cp)); 497 /* Convert and verify optional port */ 498 if (tmp != NULL && *tmp != '\0') { 499 if ((port = a2port(tmp)) <= 0) 500 goto out; 501 } 502 /* Success */ 503 if (userp != NULL) { 504 *userp = user; 505 user = NULL; 506 } 507 if (hostp != NULL) { 508 *hostp = host; 509 host = NULL; 510 } 511 if (portp != NULL) 512 *portp = port; 513 ret = 0; 514 out: 515 free(sdup); 516 free(user); 517 free(host); 518 return ret; 519 } 520 521 /* function to assist building execv() arguments */ 522 void 523 addargs(arglist *args, char *fmt, ...) 524 { 525 va_list ap; 526 char *cp; 527 u_int nalloc; 528 int r; 529 530 va_start(ap, fmt); 531 r = vasprintf(&cp, fmt, ap); 532 va_end(ap); 533 if (r == -1) 534 fatal("addargs: argument too long"); 535 536 nalloc = args->nalloc; 537 if (args->list == NULL) { 538 nalloc = 32; 539 args->num = 0; 540 } else if (args->num+2 >= nalloc) 541 nalloc *= 2; 542 543 args->list = xreallocarray(args->list, nalloc, sizeof(char *)); 544 args->nalloc = nalloc; 545 args->list[args->num++] = cp; 546 args->list[args->num] = NULL; 547 } 548 549 void 550 replacearg(arglist *args, u_int which, char *fmt, ...) 551 { 552 va_list ap; 553 char *cp; 554 int r; 555 556 va_start(ap, fmt); 557 r = vasprintf(&cp, fmt, ap); 558 va_end(ap); 559 if (r == -1) 560 fatal("replacearg: argument too long"); 561 562 if (which >= args->num) 563 fatal("replacearg: tried to replace invalid arg %d >= %d", 564 which, args->num); 565 free(args->list[which]); 566 args->list[which] = cp; 567 } 568 569 void 570 freeargs(arglist *args) 571 { 572 u_int i; 573 574 if (args->list != NULL) { 575 for (i = 0; i < args->num; i++) 576 free(args->list[i]); 577 free(args->list); 578 args->nalloc = args->num = 0; 579 args->list = NULL; 580 } 581 } 582 583 /* 584 * Expands tildes in the file name. Returns data allocated by xmalloc. 585 * Warning: this calls getpw*. 586 */ 587 char * 588 tilde_expand_filename(const char *filename, uid_t uid) 589 { 590 const char *path, *sep; 591 char user[128], *ret; 592 struct passwd *pw; 593 u_int len, slash; 594 595 if (*filename != '~') 596 return (xstrdup(filename)); 597 filename++; 598 599 path = strchr(filename, '/'); 600 if (path != NULL && path > filename) { /* ~user/path */ 601 slash = path - filename; 602 if (slash > sizeof(user) - 1) 603 fatal("tilde_expand_filename: ~username too long"); 604 memcpy(user, filename, slash); 605 user[slash] = '\0'; 606 if ((pw = getpwnam(user)) == NULL) 607 fatal("tilde_expand_filename: No such user %s", user); 608 } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ 609 fatal("tilde_expand_filename: No such uid %ld", (long)uid); 610 611 /* Make sure directory has a trailing '/' */ 612 len = strlen(pw->pw_dir); 613 if (len == 0 || pw->pw_dir[len - 1] != '/') 614 sep = "/"; 615 else 616 sep = ""; 617 618 /* Skip leading '/' from specified path */ 619 if (path != NULL) 620 filename = path + 1; 621 622 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) 623 fatal("tilde_expand_filename: Path too long"); 624 625 return (ret); 626 } 627 628 /* 629 * Expand a string with a set of %[char] escapes. A number of escapes may be 630 * specified as (char *escape_chars, char *replacement) pairs. The list must 631 * be terminated by a NULL escape_char. Returns replaced string in memory 632 * allocated by xmalloc. 633 */ 634 char * 635 percent_expand(const char *string, ...) 636 { 637 #define EXPAND_MAX_KEYS 16 638 u_int num_keys, i, j; 639 struct { 640 const char *key; 641 const char *repl; 642 } keys[EXPAND_MAX_KEYS]; 643 char buf[4096]; 644 va_list ap; 645 646 /* Gather keys */ 647 va_start(ap, string); 648 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 649 keys[num_keys].key = va_arg(ap, char *); 650 if (keys[num_keys].key == NULL) 651 break; 652 keys[num_keys].repl = va_arg(ap, char *); 653 if (keys[num_keys].repl == NULL) 654 fatal("%s: NULL replacement", __func__); 655 } 656 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 657 fatal("%s: too many keys", __func__); 658 va_end(ap); 659 660 /* Expand string */ 661 *buf = '\0'; 662 for (i = 0; *string != '\0'; string++) { 663 if (*string != '%') { 664 append: 665 buf[i++] = *string; 666 if (i >= sizeof(buf)) 667 fatal("%s: string too long", __func__); 668 buf[i] = '\0'; 669 continue; 670 } 671 string++; 672 /* %% case */ 673 if (*string == '%') 674 goto append; 675 if (*string == '\0') 676 fatal("%s: invalid format", __func__); 677 for (j = 0; j < num_keys; j++) { 678 if (strchr(keys[j].key, *string) != NULL) { 679 i = strlcat(buf, keys[j].repl, sizeof(buf)); 680 if (i >= sizeof(buf)) 681 fatal("%s: string too long", __func__); 682 break; 683 } 684 } 685 if (j >= num_keys) 686 fatal("%s: unknown key %%%c", __func__, *string); 687 } 688 return (xstrdup(buf)); 689 #undef EXPAND_MAX_KEYS 690 } 691 692 /* 693 * Read an entire line from a public key file into a static buffer, discarding 694 * lines that exceed the buffer size. Returns 0 on success, -1 on failure. 695 */ 696 int 697 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz, 698 u_long *lineno) 699 { 700 while (fgets(buf, bufsz, f) != NULL) { 701 if (buf[0] == '\0') 702 continue; 703 (*lineno)++; 704 if (buf[strlen(buf) - 1] == '\n' || feof(f)) { 705 return 0; 706 } else { 707 debug("%s: %s line %lu exceeds size limit", __func__, 708 filename, *lineno); 709 /* discard remainder of line */ 710 while (fgetc(f) != '\n' && !feof(f)) 711 ; /* nothing */ 712 } 713 } 714 return -1; 715 } 716 717 int 718 tun_open(int tun, int mode) 719 { 720 #if defined(CUSTOM_SYS_TUN_OPEN) 721 return (sys_tun_open(tun, mode)); 722 #elif defined(SSH_TUN_OPENBSD) 723 struct ifreq ifr; 724 char name[100]; 725 int fd = -1, sock; 726 const char *tunbase = "tun"; 727 728 if (mode == SSH_TUNMODE_ETHERNET) 729 tunbase = "tap"; 730 731 /* Open the tunnel device */ 732 if (tun <= SSH_TUNID_MAX) { 733 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 734 fd = open(name, O_RDWR); 735 } else if (tun == SSH_TUNID_ANY) { 736 for (tun = 100; tun >= 0; tun--) { 737 snprintf(name, sizeof(name), "/dev/%s%d", 738 tunbase, tun); 739 if ((fd = open(name, O_RDWR)) >= 0) 740 break; 741 } 742 } else { 743 debug("%s: invalid tunnel %u", __func__, tun); 744 return -1; 745 } 746 747 if (fd < 0) { 748 debug("%s: %s open: %s", __func__, name, strerror(errno)); 749 return -1; 750 } 751 752 debug("%s: %s mode %d fd %d", __func__, name, mode, fd); 753 754 /* Bring interface up if it is not already */ 755 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 756 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 757 goto failed; 758 759 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 760 debug("%s: get interface %s flags: %s", __func__, 761 ifr.ifr_name, strerror(errno)); 762 goto failed; 763 } 764 765 if (!(ifr.ifr_flags & IFF_UP)) { 766 ifr.ifr_flags |= IFF_UP; 767 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 768 debug("%s: activate interface %s: %s", __func__, 769 ifr.ifr_name, strerror(errno)); 770 goto failed; 771 } 772 } 773 774 close(sock); 775 return fd; 776 777 failed: 778 if (fd >= 0) 779 close(fd); 780 if (sock >= 0) 781 close(sock); 782 return -1; 783 #else 784 error("Tunnel interfaces are not supported on this platform"); 785 return (-1); 786 #endif 787 } 788 789 void 790 sanitise_stdfd(void) 791 { 792 int nullfd, dupfd; 793 794 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 795 fprintf(stderr, "Couldn't open /dev/null: %s\n", 796 strerror(errno)); 797 exit(1); 798 } 799 while (++dupfd <= STDERR_FILENO) { 800 /* Only populate closed fds. */ 801 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 802 if (dup2(nullfd, dupfd) == -1) { 803 fprintf(stderr, "dup2: %s\n", strerror(errno)); 804 exit(1); 805 } 806 } 807 } 808 if (nullfd > STDERR_FILENO) 809 close(nullfd); 810 } 811 812 char * 813 tohex(const void *vp, size_t l) 814 { 815 const u_char *p = (const u_char *)vp; 816 char b[3], *r; 817 size_t i, hl; 818 819 if (l > 65536) 820 return xstrdup("tohex: length > 65536"); 821 822 hl = l * 2 + 1; 823 r = xcalloc(1, hl); 824 for (i = 0; i < l; i++) { 825 snprintf(b, sizeof(b), "%02x", p[i]); 826 strlcat(r, b, hl); 827 } 828 return (r); 829 } 830 831 u_int64_t 832 get_u64(const void *vp) 833 { 834 const u_char *p = (const u_char *)vp; 835 u_int64_t v; 836 837 v = (u_int64_t)p[0] << 56; 838 v |= (u_int64_t)p[1] << 48; 839 v |= (u_int64_t)p[2] << 40; 840 v |= (u_int64_t)p[3] << 32; 841 v |= (u_int64_t)p[4] << 24; 842 v |= (u_int64_t)p[5] << 16; 843 v |= (u_int64_t)p[6] << 8; 844 v |= (u_int64_t)p[7]; 845 846 return (v); 847 } 848 849 u_int32_t 850 get_u32(const void *vp) 851 { 852 const u_char *p = (const u_char *)vp; 853 u_int32_t v; 854 855 v = (u_int32_t)p[0] << 24; 856 v |= (u_int32_t)p[1] << 16; 857 v |= (u_int32_t)p[2] << 8; 858 v |= (u_int32_t)p[3]; 859 860 return (v); 861 } 862 863 u_int32_t 864 get_u32_le(const void *vp) 865 { 866 const u_char *p = (const u_char *)vp; 867 u_int32_t v; 868 869 v = (u_int32_t)p[0]; 870 v |= (u_int32_t)p[1] << 8; 871 v |= (u_int32_t)p[2] << 16; 872 v |= (u_int32_t)p[3] << 24; 873 874 return (v); 875 } 876 877 u_int16_t 878 get_u16(const void *vp) 879 { 880 const u_char *p = (const u_char *)vp; 881 u_int16_t v; 882 883 v = (u_int16_t)p[0] << 8; 884 v |= (u_int16_t)p[1]; 885 886 return (v); 887 } 888 889 void 890 put_u64(void *vp, u_int64_t v) 891 { 892 u_char *p = (u_char *)vp; 893 894 p[0] = (u_char)(v >> 56) & 0xff; 895 p[1] = (u_char)(v >> 48) & 0xff; 896 p[2] = (u_char)(v >> 40) & 0xff; 897 p[3] = (u_char)(v >> 32) & 0xff; 898 p[4] = (u_char)(v >> 24) & 0xff; 899 p[5] = (u_char)(v >> 16) & 0xff; 900 p[6] = (u_char)(v >> 8) & 0xff; 901 p[7] = (u_char)v & 0xff; 902 } 903 904 void 905 put_u32(void *vp, u_int32_t v) 906 { 907 u_char *p = (u_char *)vp; 908 909 p[0] = (u_char)(v >> 24) & 0xff; 910 p[1] = (u_char)(v >> 16) & 0xff; 911 p[2] = (u_char)(v >> 8) & 0xff; 912 p[3] = (u_char)v & 0xff; 913 } 914 915 void 916 put_u32_le(void *vp, u_int32_t v) 917 { 918 u_char *p = (u_char *)vp; 919 920 p[0] = (u_char)v & 0xff; 921 p[1] = (u_char)(v >> 8) & 0xff; 922 p[2] = (u_char)(v >> 16) & 0xff; 923 p[3] = (u_char)(v >> 24) & 0xff; 924 } 925 926 void 927 put_u16(void *vp, u_int16_t v) 928 { 929 u_char *p = (u_char *)vp; 930 931 p[0] = (u_char)(v >> 8) & 0xff; 932 p[1] = (u_char)v & 0xff; 933 } 934 935 void 936 ms_subtract_diff(struct timeval *start, int *ms) 937 { 938 struct timeval diff, finish; 939 940 gettimeofday(&finish, NULL); 941 timersub(&finish, start, &diff); 942 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 943 } 944 945 void 946 ms_to_timeval(struct timeval *tv, int ms) 947 { 948 if (ms < 0) 949 ms = 0; 950 tv->tv_sec = ms / 1000; 951 tv->tv_usec = (ms % 1000) * 1000; 952 } 953 954 time_t 955 monotime(void) 956 { 957 #if defined(HAVE_CLOCK_GETTIME) && \ 958 (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME)) 959 struct timespec ts; 960 static int gettime_failed = 0; 961 962 if (!gettime_failed) { 963 #if defined(CLOCK_BOOTTIME) 964 if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0) 965 return (ts.tv_sec); 966 #endif 967 #if defined(CLOCK_MONOTONIC) 968 if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) 969 return (ts.tv_sec); 970 #endif 971 debug3("clock_gettime: %s", strerror(errno)); 972 gettime_failed = 1; 973 } 974 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */ 975 976 return time(NULL); 977 } 978 979 double 980 monotime_double(void) 981 { 982 #if defined(HAVE_CLOCK_GETTIME) && \ 983 (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME)) 984 struct timespec ts; 985 static int gettime_failed = 0; 986 987 if (!gettime_failed) { 988 #if defined(CLOCK_BOOTTIME) 989 if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0) 990 return (ts.tv_sec + (double)ts.tv_nsec / 1000000000); 991 #endif 992 #if defined(CLOCK_MONOTONIC) 993 if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) 994 return (ts.tv_sec + (double)ts.tv_nsec / 1000000000); 995 #endif 996 debug3("clock_gettime: %s", strerror(errno)); 997 gettime_failed = 1; 998 } 999 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */ 1000 1001 return (double)time(NULL); 1002 } 1003 1004 void 1005 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1006 { 1007 bw->buflen = buflen; 1008 bw->rate = kbps; 1009 bw->thresh = bw->rate; 1010 bw->lamt = 0; 1011 timerclear(&bw->bwstart); 1012 timerclear(&bw->bwend); 1013 } 1014 1015 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1016 void 1017 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1018 { 1019 u_int64_t waitlen; 1020 struct timespec ts, rm; 1021 1022 if (!timerisset(&bw->bwstart)) { 1023 gettimeofday(&bw->bwstart, NULL); 1024 return; 1025 } 1026 1027 bw->lamt += read_len; 1028 if (bw->lamt < bw->thresh) 1029 return; 1030 1031 gettimeofday(&bw->bwend, NULL); 1032 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1033 if (!timerisset(&bw->bwend)) 1034 return; 1035 1036 bw->lamt *= 8; 1037 waitlen = (double)1000000L * bw->lamt / bw->rate; 1038 1039 bw->bwstart.tv_sec = waitlen / 1000000L; 1040 bw->bwstart.tv_usec = waitlen % 1000000L; 1041 1042 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1043 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1044 1045 /* Adjust the wait time */ 1046 if (bw->bwend.tv_sec) { 1047 bw->thresh /= 2; 1048 if (bw->thresh < bw->buflen / 4) 1049 bw->thresh = bw->buflen / 4; 1050 } else if (bw->bwend.tv_usec < 10000) { 1051 bw->thresh *= 2; 1052 if (bw->thresh > bw->buflen * 8) 1053 bw->thresh = bw->buflen * 8; 1054 } 1055 1056 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1057 while (nanosleep(&ts, &rm) == -1) { 1058 if (errno != EINTR) 1059 break; 1060 ts = rm; 1061 } 1062 } 1063 1064 bw->lamt = 0; 1065 gettimeofday(&bw->bwstart, NULL); 1066 } 1067 1068 /* Make a template filename for mk[sd]temp() */ 1069 void 1070 mktemp_proto(char *s, size_t len) 1071 { 1072 const char *tmpdir; 1073 int r; 1074 1075 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1076 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1077 if (r > 0 && (size_t)r < len) 1078 return; 1079 } 1080 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1081 if (r < 0 || (size_t)r >= len) 1082 fatal("%s: template string too short", __func__); 1083 } 1084 1085 static const struct { 1086 const char *name; 1087 int value; 1088 } ipqos[] = { 1089 { "af11", IPTOS_DSCP_AF11 }, 1090 { "af12", IPTOS_DSCP_AF12 }, 1091 { "af13", IPTOS_DSCP_AF13 }, 1092 { "af21", IPTOS_DSCP_AF21 }, 1093 { "af22", IPTOS_DSCP_AF22 }, 1094 { "af23", IPTOS_DSCP_AF23 }, 1095 { "af31", IPTOS_DSCP_AF31 }, 1096 { "af32", IPTOS_DSCP_AF32 }, 1097 { "af33", IPTOS_DSCP_AF33 }, 1098 { "af41", IPTOS_DSCP_AF41 }, 1099 { "af42", IPTOS_DSCP_AF42 }, 1100 { "af43", IPTOS_DSCP_AF43 }, 1101 { "cs0", IPTOS_DSCP_CS0 }, 1102 { "cs1", IPTOS_DSCP_CS1 }, 1103 { "cs2", IPTOS_DSCP_CS2 }, 1104 { "cs3", IPTOS_DSCP_CS3 }, 1105 { "cs4", IPTOS_DSCP_CS4 }, 1106 { "cs5", IPTOS_DSCP_CS5 }, 1107 { "cs6", IPTOS_DSCP_CS6 }, 1108 { "cs7", IPTOS_DSCP_CS7 }, 1109 { "ef", IPTOS_DSCP_EF }, 1110 { "lowdelay", IPTOS_LOWDELAY }, 1111 { "throughput", IPTOS_THROUGHPUT }, 1112 { "reliability", IPTOS_RELIABILITY }, 1113 { NULL, -1 } 1114 }; 1115 1116 int 1117 parse_ipqos(const char *cp) 1118 { 1119 u_int i; 1120 char *ep; 1121 long val; 1122 1123 if (cp == NULL) 1124 return -1; 1125 for (i = 0; ipqos[i].name != NULL; i++) { 1126 if (strcasecmp(cp, ipqos[i].name) == 0) 1127 return ipqos[i].value; 1128 } 1129 /* Try parsing as an integer */ 1130 val = strtol(cp, &ep, 0); 1131 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) 1132 return -1; 1133 return val; 1134 } 1135 1136 const char * 1137 iptos2str(int iptos) 1138 { 1139 int i; 1140 static char iptos_str[sizeof "0xff"]; 1141 1142 for (i = 0; ipqos[i].name != NULL; i++) { 1143 if (ipqos[i].value == iptos) 1144 return ipqos[i].name; 1145 } 1146 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1147 return iptos_str; 1148 } 1149 1150 void 1151 lowercase(char *s) 1152 { 1153 for (; *s; s++) 1154 *s = tolower((u_char)*s); 1155 } 1156 1157 int 1158 unix_listener(const char *path, int backlog, int unlink_first) 1159 { 1160 struct sockaddr_un sunaddr; 1161 int saved_errno, sock; 1162 1163 memset(&sunaddr, 0, sizeof(sunaddr)); 1164 sunaddr.sun_family = AF_UNIX; 1165 if (strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1166 error("%s: \"%s\" too long for Unix domain socket", __func__, 1167 path); 1168 errno = ENAMETOOLONG; 1169 return -1; 1170 } 1171 1172 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1173 if (sock < 0) { 1174 saved_errno = errno; 1175 error("socket: %.100s", strerror(errno)); 1176 errno = saved_errno; 1177 return -1; 1178 } 1179 if (unlink_first == 1) { 1180 if (unlink(path) != 0 && errno != ENOENT) 1181 error("unlink(%s): %.100s", path, strerror(errno)); 1182 } 1183 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) { 1184 saved_errno = errno; 1185 error("bind: %.100s", strerror(errno)); 1186 close(sock); 1187 error("%s: cannot bind to path: %s", __func__, path); 1188 errno = saved_errno; 1189 return -1; 1190 } 1191 if (listen(sock, backlog) < 0) { 1192 saved_errno = errno; 1193 error("listen: %.100s", strerror(errno)); 1194 close(sock); 1195 unlink(path); 1196 error("%s: cannot listen on path: %s", __func__, path); 1197 errno = saved_errno; 1198 return -1; 1199 } 1200 return sock; 1201 } 1202 1203 void 1204 sock_set_v6only(int s) 1205 { 1206 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__) 1207 int on = 1; 1208 1209 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s); 1210 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) 1211 error("setsockopt IPV6_V6ONLY: %s", strerror(errno)); 1212 #endif 1213 } 1214 1215 /* 1216 * Compares two strings that maybe be NULL. Returns non-zero if strings 1217 * are both NULL or are identical, returns zero otherwise. 1218 */ 1219 static int 1220 strcmp_maybe_null(const char *a, const char *b) 1221 { 1222 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1223 return 0; 1224 if (a != NULL && strcmp(a, b) != 0) 1225 return 0; 1226 return 1; 1227 } 1228 1229 /* 1230 * Compare two forwards, returning non-zero if they are identical or 1231 * zero otherwise. 1232 */ 1233 int 1234 forward_equals(const struct Forward *a, const struct Forward *b) 1235 { 1236 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1237 return 0; 1238 if (a->listen_port != b->listen_port) 1239 return 0; 1240 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1241 return 0; 1242 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1243 return 0; 1244 if (a->connect_port != b->connect_port) 1245 return 0; 1246 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1247 return 0; 1248 /* allocated_port and handle are not checked */ 1249 return 1; 1250 } 1251 1252 static int 1253 ipport_reserved(void) 1254 { 1255 #if __FreeBSD__ 1256 int old, ret; 1257 size_t len = sizeof(old); 1258 1259 ret = sysctlbyname("net.inet.ip.portrange.reservedhigh", 1260 &old, &len, NULL, 0); 1261 if (ret == 0) 1262 return (old + 1); 1263 #endif 1264 return (IPPORT_RESERVED); 1265 } 1266 1267 /* returns 1 if bind to specified port by specified user is permitted */ 1268 int 1269 bind_permitted(int port, uid_t uid) 1270 { 1271 1272 if (port < ipport_reserved() && uid != 0) 1273 return 0; 1274 return 1; 1275 } 1276 1277 /* returns 1 if process is already daemonized, 0 otherwise */ 1278 int 1279 daemonized(void) 1280 { 1281 int fd; 1282 1283 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1284 close(fd); 1285 return 0; /* have controlling terminal */ 1286 } 1287 if (getppid() != 1) 1288 return 0; /* parent is not init */ 1289 if (getsid(0) != getpid()) 1290 return 0; /* not session leader */ 1291 debug3("already daemonized"); 1292 return 1; 1293 } 1294