misc.c

   1 /* $OpenBSD: misc.c,v 1.73 2009/11/20 03:24:07 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/param.h>
  33
  34 #include <stdarg.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39
  40 #include <netinet/in.h>
  41 #include <netinet/tcp.h>
  42
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <netdb.h>
  46 #ifdef HAVE_PATHS_H
  47 # include <paths.h>
  48 #include <pwd.h>
  49 #endif
  50 #ifdef SSH_TUN_OPENBSD
  51 #include <net/if.h>
  52 #endif
  53
  54 #include "xmalloc.h"
  55 #include "misc.h"
  56 #include "log.h"
  57 #include "ssh.h"
  58
  59 /* remove newline at end of string */
  60 char *
  61 chop(char *s)
  62 {
  63         char *t = s;
  64         while (*t) {
  65                 if (*t == '\n' || *t == '\r') {
  66                         *t = '\0';
  67                         return s;
  68                 }
  69                 t++;
  70         }
  71         return s;
  72
  73 }
  74
  75 /* set/unset filedescriptor to non-blocking */
  76 int
  77 set_nonblock(int fd)
  78 {
  79         int val;
  80
  81         val = fcntl(fd, F_GETFL, 0);
  82         if (val < 0) {
  83                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
  84                 return (-1);
  85         }
  86         if (val & O_NONBLOCK) {
  87                 debug3("fd %d is O_NONBLOCK", fd);
  88                 return (0);
  89         }
  90         debug2("fd %d setting O_NONBLOCK", fd);
  91         val |= O_NONBLOCK;
  92         if (fcntl(fd, F_SETFL, val) == -1) {
  93                 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
  94                     strerror(errno));
  95                 return (-1);
  96         }
  97         return (0);
  98 }
  99
 100 int
 101 unset_nonblock(int fd)
 102 {
 103         int val;
 104
 105         val = fcntl(fd, F_GETFL, 0);
 106         if (val < 0) {
 107                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
 108                 return (-1);
 109         }
 110         if (!(val & O_NONBLOCK)) {
 111                 debug3("fd %d is not O_NONBLOCK", fd);
 112                 return (0);
 113         }
 114         debug("fd %d clearing O_NONBLOCK", fd);
 115         val &= ~O_NONBLOCK;
 116         if (fcntl(fd, F_SETFL, val) == -1) {
 117                 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
 118                     fd, strerror(errno));
 119                 return (-1);
 120         }
 121         return (0);
 122 }
 123
 124 const char *
 125 ssh_gai_strerror(int gaierr)
 126 {
 127         if (gaierr == EAI_SYSTEM)
 128                 return strerror(errno);
 129         return gai_strerror(gaierr);
 130 }
 131
 132 /* disable nagle on socket */
 133 void
 134 set_nodelay(int fd)
 135 {
 136         int opt;
 137         socklen_t optlen;
 138
 139         optlen = sizeof opt;
 140         if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
 141                 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
 142                 return;
 143         }
 144         if (opt == 1) {
 145                 debug2("fd %d is TCP_NODELAY", fd);
 146                 return;
 147         }
 148         opt = 1;
 149         debug2("fd %d setting TCP_NODELAY", fd);
 150         if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
 151                 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
 152 }
 153
 154 /* open a socket in the specified routing domain */
 155 int
 156 socket_rdomain(int domain, int type, int protocol, int rdomain)
 157 {
 158         int sock, ipproto = IPPROTO_IP;
 159
 160         if ((sock = socket(domain, type, protocol)) == -1)
 161                 return (-1);
 162
 163         if (rdomain == -1)
 164                 return (sock);
 165
 166         switch (domain) {
 167         case AF_INET6:
 168                 ipproto = IPPROTO_IPV6;
 169                 /* FALLTHROUGH */
 170         case AF_INET:
 171                 debug2("socket %d af %d setting rdomain %d",
 172                     sock, domain, rdomain);
 173                 if (setsockopt(sock, ipproto, SO_RDOMAIN, &rdomain,
 174                     sizeof(rdomain)) == -1) {
 175                         debug("setsockopt SO_RDOMAIN: %.100s",
 176                             strerror(errno));
 177                         close(sock);
 178                         return (-1);
 179                 }
 180                 break;
 181         default:
 182                 debug("socket %d af %d does not support rdomain %d",
 183                     sock, domain, rdomain);
 184                 close(sock);
 185                 return (-1);
 186         }
 187
 188         return (sock);
 189 }
 190
 191 /* Characters considered whitespace in strsep calls. */
 192 #define WHITESPACE " \t\r\n"
 193 #define QUOTE   "\""
 194
 195 /* return next token in configuration line */
 196 char *
 197 strdelim(char **s)
 198 {
 199         char *old;
 200         int wspace = 0;
 201
 202         if (*s == NULL)
 203                 return NULL;
 204
 205         old = *s;
 206
 207         *s = strpbrk(*s, WHITESPACE QUOTE "=");
 208         if (*s == NULL)
 209                 return (old);
 210
 211         if (*s[0] == '\"') {
 212                 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
 213                 /* Find matching quote */
 214                 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
 215                         return (NULL);          /* no matching quote */
 216                 } else {
 217                         *s[0] = '\0';
 218                         return (old);
 219                 }
 220         }
 221
 222         /* Allow only one '=' to be skipped */
 223         if (*s[0] == '=')
 224                 wspace = 1;
 225         *s[0] = '\0';
 226
 227         /* Skip any extra whitespace after first token */
 228         *s += strspn(*s + 1, WHITESPACE) + 1;
 229         if (*s[0] == '=' && !wspace)
 230                 *s += strspn(*s + 1, WHITESPACE) + 1;
 231
 232         return (old);
 233 }
 234
 235 struct passwd *
 236 pwcopy(struct passwd *pw)
 237 {
 238         struct passwd *copy = xcalloc(1, sizeof(*copy));
 239
 240         copy->pw_name = xstrdup(pw->pw_name);
 241         copy->pw_passwd = xstrdup(pw->pw_passwd);
 242         copy->pw_gecos = xstrdup(pw->pw_gecos);
 243         copy->pw_uid = pw->pw_uid;
 244         copy->pw_gid = pw->pw_gid;
 245 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
 246         copy->pw_expire = pw->pw_expire;
 247 #endif
 248 #ifdef HAVE_PW_CHANGE_IN_PASSWD
 249         copy->pw_change = pw->pw_change;
 250 #endif
 251 #ifdef HAVE_PW_CLASS_IN_PASSWD
 252         copy->pw_class = xstrdup(pw->pw_class);
 253 #endif
 254         copy->pw_dir = xstrdup(pw->pw_dir);
 255         copy->pw_shell = xstrdup(pw->pw_shell);
 256         return copy;
 257 }
 258
 259 /*
 260  * Convert ASCII string to TCP/IP port number.
 261  * Port must be >=0 and <=65535.
 262  * Return -1 if invalid.
 263  */
 264 int
 265 a2port(const char *s)
 266 {
 267         long long port;
 268         const char *errstr;
 269
 270         port = strtonum(s, 0, 65535, &errstr);
 271         if (errstr != NULL)
 272                 return -1;
 273         return (int)port;
 274 }
 275
 276 int
 277 a2tun(const char *s, int *remote)
 278 {
 279         const char *errstr = NULL;
 280         char *sp, *ep;
 281         int tun;
 282
 283         if (remote != NULL) {
 284                 *remote = SSH_TUNID_ANY;
 285                 sp = xstrdup(s);
 286                 if ((ep = strchr(sp, ':')) == NULL) {
 287                         xfree(sp);
 288                         return (a2tun(s, NULL));
 289                 }
 290                 ep[0] = '\0'; ep++;
 291                 *remote = a2tun(ep, NULL);
 292                 tun = a2tun(sp, NULL);
 293                 xfree(sp);
 294                 return (*remote == SSH_TUNID_ERR ? *remote : tun);
 295         }
 296
 297         if (strcasecmp(s, "any") == 0)
 298                 return (SSH_TUNID_ANY);
 299
 300         tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
 301         if (errstr != NULL)
 302                 return (SSH_TUNID_ERR);
 303
 304         return (tun);
 305 }
 306
 307 #define SECONDS         1
 308 #define MINUTES         (SECONDS * 60)
 309 #define HOURS           (MINUTES * 60)
 310 #define DAYS            (HOURS * 24)
 311 #define WEEKS           (DAYS * 7)
 312
 313 /*
 314  * Convert a time string into seconds; format is
 315  * a sequence of:
 316  *      time[qualifier]
 317  *
 318  * Valid time qualifiers are:
 319  *      <none>  seconds
 320  *      s|S     seconds
 321  *      m|M     minutes
 322  *      h|H     hours
 323  *      d|D     days
 324  *      w|W     weeks
 325  *
 326  * Examples:
 327  *      90m     90 minutes
 328  *      1h30m   90 minutes
 329  *      2d      2 days
 330  *      1w      1 week
 331  *
 332  * Return -1 if time string is invalid.
 333  */
 334 long
 335 convtime(const char *s)
 336 {
 337         long total, secs;
 338         const char *p;
 339         char *endp;
 340
 341         errno = 0;
 342         total = 0;
 343         p = s;
 344
 345         if (p == NULL || *p == '\0')
 346                 return -1;
 347
 348         while (*p) {
 349                 secs = strtol(p, &endp, 10);
 350                 if (p == endp ||
 351                     (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
 352                     secs < 0)
 353                         return -1;
 354
 355                 switch (*endp++) {
 356                 case '\0':
 357                         endp--;
 358                         break;
 359                 case 's':
 360                 case 'S':
 361                         break;
 362                 case 'm':
 363                 case 'M':
 364                         secs *= MINUTES;
 365                         break;
 366                 case 'h':
 367                 case 'H':
 368                         secs *= HOURS;
 369                         break;
 370                 case 'd':
 371                 case 'D':
 372                         secs *= DAYS;
 373                         break;
 374                 case 'w':
 375                 case 'W':
 376                         secs *= WEEKS;
 377                         break;
 378                 default:
 379                         return -1;
 380                 }
 381                 total += secs;
 382                 if (total < 0)
 383                         return -1;
 384                 p = endp;
 385         }
 386
 387         return total;
 388 }
 389
 390 /*
 391  * Returns a standardized host+port identifier string.
 392  * Caller must free returned string.
 393  */
 394 char *
 395 put_host_port(const char *host, u_short port)
 396 {
 397         char *hoststr;
 398
 399         if (port == 0 || port == SSH_DEFAULT_PORT)
 400                 return(xstrdup(host));
 401         if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
 402                 fatal("put_host_port: asprintf: %s", strerror(errno));
 403         debug3("put_host_port: %s", hoststr);
 404         return hoststr;
 405 }
 406
 407 /*
 408  * Search for next delimiter between hostnames/addresses and ports.
 409  * Argument may be modified (for termination).
 410  * Returns *cp if parsing succeeds.
 411  * *cp is set to the start of the next delimiter, if one was found.
 412  * If this is the last field, *cp is set to NULL.
 413  */
 414 char *
 415 hpdelim(char **cp)
 416 {
 417         char *s, *old;
 418
 419         if (cp == NULL || *cp == NULL)
 420                 return NULL;
 421
 422         old = s = *cp;
 423         if (*s == '[') {
 424                 if ((s = strchr(s, ']')) == NULL)
 425                         return NULL;
 426                 else
 427                         s++;
 428         } else if ((s = strpbrk(s, ":/")) == NULL)
 429                 s = *cp + strlen(*cp); /* skip to end (see first case below) */
 430
 431         switch (*s) {
 432         case '\0':
 433                 *cp = NULL;     /* no more fields*/
 434                 break;
 435
 436         case ':':
 437         case '/':
 438                 *s = '\0';      /* terminate */
 439                 *cp = s + 1;
 440                 break;
 441
 442         default:
 443                 return NULL;
 444         }
 445
 446         return old;
 447 }
 448
 449 char *
 450 cleanhostname(char *host)
 451 {
 452         if (*host == '[' && host[strlen(host) - 1] == ']') {
 453                 host[strlen(host) - 1] = '\0';
 454                 return (host + 1);
 455         } else
 456                 return host;
 457 }
 458
 459 char *
 460 colon(char *cp)
 461 {
 462         int flag = 0;
 463
 464         if (*cp == ':')         /* Leading colon is part of file name. */
 465                 return (0);
 466         if (*cp == '[')
 467                 flag = 1;
 468
 469         for (; *cp; ++cp) {
 470                 if (*cp == '@' && *(cp+1) == '[')
 471                         flag = 1;
 472                 if (*cp == ']' && *(cp+1) == ':' && flag)
 473                         return (cp+1);
 474                 if (*cp == ':' && !flag)
 475                         return (cp);
 476                 if (*cp == '/')
 477                         return (0);
 478         }
 479         return (0);
 480 }
 481
 482 /* function to assist building execv() arguments */
 483 void
 484 addargs(arglist *args, char *fmt, ...)
 485 {
 486         va_list ap;
 487         char *cp;
 488         u_int nalloc;
 489         int r;
 490
 491         va_start(ap, fmt);
 492         r = vasprintf(&cp, fmt, ap);
 493         va_end(ap);
 494         if (r == -1)
 495                 fatal("addargs: argument too long");
 496
 497         nalloc = args->nalloc;
 498         if (args->list == NULL) {
 499                 nalloc = 32;
 500                 args->num = 0;
 501         } else if (args->num+2 >= nalloc)
 502                 nalloc *= 2;
 503
 504         args->list = xrealloc(args->list, nalloc, sizeof(char *));
 505         args->nalloc = nalloc;
 506         args->list[args->num++] = cp;
 507         args->list[args->num] = NULL;
 508 }
 509
 510 void
 511 replacearg(arglist *args, u_int which, char *fmt, ...)
 512 {
 513         va_list ap;
 514         char *cp;
 515         int r;
 516
 517         va_start(ap, fmt);
 518         r = vasprintf(&cp, fmt, ap);
 519         va_end(ap);
 520         if (r == -1)
 521                 fatal("replacearg: argument too long");
 522
 523         if (which >= args->num)
 524                 fatal("replacearg: tried to replace invalid arg %d >= %d",
 525                     which, args->num);
 526         xfree(args->list[which]);
 527         args->list[which] = cp;
 528 }
 529
 530 void
 531 freeargs(arglist *args)
 532 {
 533         u_int i;
 534
 535         if (args->list != NULL) {
 536                 for (i = 0; i < args->num; i++)
 537                         xfree(args->list[i]);
 538                 xfree(args->list);
 539                 args->nalloc = args->num = 0;
 540                 args->list = NULL;
 541         }
 542 }
 543
 544 /*
 545  * Expands tildes in the file name.  Returns data allocated by xmalloc.
 546  * Warning: this calls getpw*.
 547  */
 548 char *
 549 tilde_expand_filename(const char *filename, uid_t uid)
 550 {
 551         const char *path;
 552         char user[128], ret[MAXPATHLEN];
 553         struct passwd *pw;
 554         u_int len, slash;
 555
 556         if (*filename != '~')
 557                 return (xstrdup(filename));
 558         filename++;
 559
 560         path = strchr(filename, '/');
 561         if (path != NULL && path > filename) {          /* ~user/path */
 562                 slash = path - filename;
 563                 if (slash > sizeof(user) - 1)
 564                         fatal("tilde_expand_filename: ~username too long");
 565                 memcpy(user, filename, slash);
 566                 user[slash] = '\0';
 567                 if ((pw = getpwnam(user)) == NULL)
 568                         fatal("tilde_expand_filename: No such user %s", user);
 569         } else if ((pw = getpwuid(uid)) == NULL)        /* ~/path */
 570                 fatal("tilde_expand_filename: No such uid %ld", (long)uid);
 571
 572         if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
 573                 fatal("tilde_expand_filename: Path too long");
 574
 575         /* Make sure directory has a trailing '/' */
 576         len = strlen(pw->pw_dir);
 577         if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
 578             strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
 579                 fatal("tilde_expand_filename: Path too long");
 580
 581         /* Skip leading '/' from specified path */
 582         if (path != NULL)
 583                 filename = path + 1;
 584         if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
 585                 fatal("tilde_expand_filename: Path too long");
 586
 587         return (xstrdup(ret));
 588 }
 589
 590 /*
 591  * Expand a string with a set of %[char] escapes. A number of escapes may be
 592  * specified as (char *escape_chars, char *replacement) pairs. The list must
 593  * be terminated by a NULL escape_char. Returns replaced string in memory
 594  * allocated by xmalloc.
 595  */
 596 char *
 597 percent_expand(const char *string, ...)
 598 {
 599 #define EXPAND_MAX_KEYS 16
 600         u_int num_keys, i, j;
 601         struct {
 602                 const char *key;
 603                 const char *repl;
 604         } keys[EXPAND_MAX_KEYS];
 605         char buf[4096];
 606         va_list ap;
 607
 608         /* Gather keys */
 609         va_start(ap, string);
 610         for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
 611                 keys[num_keys].key = va_arg(ap, char *);
 612                 if (keys[num_keys].key == NULL)
 613                         break;
 614                 keys[num_keys].repl = va_arg(ap, char *);
 615                 if (keys[num_keys].repl == NULL)
 616                         fatal("%s: NULL replacement", __func__);
 617         }
 618         if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
 619                 fatal("%s: too many keys", __func__);
 620         va_end(ap);
 621
 622         /* Expand string */
 623         *buf = '\0';
 624         for (i = 0; *string != '\0'; string++) {
 625                 if (*string != '%') {
 626  append:
 627                         buf[i++] = *string;
 628                         if (i >= sizeof(buf))
 629                                 fatal("%s: string too long", __func__);
 630                         buf[i] = '\0';
 631                         continue;
 632                 }
 633                 string++;
 634                 /* %% case */
 635                 if (*string == '%')
 636                         goto append;
 637                 for (j = 0; j < num_keys; j++) {
 638                         if (strchr(keys[j].key, *string) != NULL) {
 639                                 i = strlcat(buf, keys[j].repl, sizeof(buf));
 640                                 if (i >= sizeof(buf))
 641                                         fatal("%s: string too long", __func__);
 642                                 break;
 643                         }
 644                 }
 645                 if (j >= num_keys)
 646                         fatal("%s: unknown key %%%c", __func__, *string);
 647         }
 648         return (xstrdup(buf));
 649 #undef EXPAND_MAX_KEYS
 650 }
 651
 652 /*
 653  * Read an entire line from a public key file into a static buffer, discarding
 654  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 655  */
 656 int
 657 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 658    u_long *lineno)
 659 {
 660         while (fgets(buf, bufsz, f) != NULL) {
 661                 if (buf[0] == '\0')
 662                         continue;
 663                 (*lineno)++;
 664                 if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
 665                         return 0;
 666                 } else {
 667                         debug("%s: %s line %lu exceeds size limit", __func__,
 668                             filename, *lineno);
 669                         /* discard remainder of line */
 670                         while (fgetc(f) != '\n' && !feof(f))
 671                                 ;       /* nothing */
 672                 }
 673         }
 674         return -1;
 675 }
 676
 677 int
 678 tun_open(int tun, int mode)
 679 {
 680 #if defined(CUSTOM_SYS_TUN_OPEN)
 681         return (sys_tun_open(tun, mode));
 682 #elif defined(SSH_TUN_OPENBSD)
 683         struct ifreq ifr;
 684         char name[100];
 685         int fd = -1, sock;
 686
 687         /* Open the tunnel device */
 688         if (tun <= SSH_TUNID_MAX) {
 689                 snprintf(name, sizeof(name), "/dev/tun%d", tun);
 690                 fd = open(name, O_RDWR);
 691         } else if (tun == SSH_TUNID_ANY) {
 692                 for (tun = 100; tun >= 0; tun--) {
 693                         snprintf(name, sizeof(name), "/dev/tun%d", tun);
 694                         if ((fd = open(name, O_RDWR)) >= 0)
 695                                 break;
 696                 }
 697         } else {
 698                 debug("%s: invalid tunnel %u", __func__, tun);
 699                 return (-1);
 700         }
 701
 702         if (fd < 0) {
 703                 debug("%s: %s open failed: %s", __func__, name, strerror(errno));
 704                 return (-1);
 705         }
 706
 707         debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 708
 709         /* Set the tunnel device operation mode */
 710         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
 711         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
 712                 goto failed;
 713
 714         if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
 715                 goto failed;
 716
 717         /* Set interface mode */
 718         ifr.ifr_flags &= ~IFF_UP;
 719         if (mode == SSH_TUNMODE_ETHERNET)
 720                 ifr.ifr_flags |= IFF_LINK0;
 721         else
 722                 ifr.ifr_flags &= ~IFF_LINK0;
 723         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 724                 goto failed;
 725
 726         /* Bring interface up */
 727         ifr.ifr_flags |= IFF_UP;
 728         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 729                 goto failed;
 730
 731         close(sock);
 732         return (fd);
 733
 734  failed:
 735         if (fd >= 0)
 736                 close(fd);
 737         if (sock >= 0)
 738                 close(sock);
 739         debug("%s: failed to set %s mode %d: %s", __func__, name,
 740             mode, strerror(errno));
 741         return (-1);
 742 #else
 743         error("Tunnel interfaces are not supported on this platform");
 744         return (-1);
 745 #endif
 746 }
 747
 748 void
 749 sanitise_stdfd(void)
 750 {
 751         int nullfd, dupfd;
 752
 753         if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
 754                 fprintf(stderr, "Couldn't open /dev/null: %s\n",
 755                     strerror(errno));
 756                 exit(1);
 757         }
 758         while (++dupfd <= 2) {
 759                 /* Only clobber closed fds */
 760                 if (fcntl(dupfd, F_GETFL, 0) >= 0)
 761                         continue;
 762                 if (dup2(nullfd, dupfd) == -1) {
 763                         fprintf(stderr, "dup2: %s\n", strerror(errno));
 764                         exit(1);
 765                 }
 766         }
 767         if (nullfd > 2)
 768                 close(nullfd);
 769 }
 770
 771 char *
 772 tohex(const void *vp, size_t l)
 773 {
 774         const u_char *p = (const u_char *)vp;
 775         char b[3], *r;
 776         size_t i, hl;
 777
 778         if (l > 65536)
 779                 return xstrdup("tohex: length > 65536");
 780
 781         hl = l * 2 + 1;
 782         r = xcalloc(1, hl);
 783         for (i = 0; i < l; i++) {
 784                 snprintf(b, sizeof(b), "%02x", p[i]);
 785                 strlcat(r, b, hl);
 786         }
 787         return (r);
 788 }
 789
 790 u_int64_t
 791 get_u64(const void *vp)
 792 {
 793         const u_char *p = (const u_char *)vp;
 794         u_int64_t v;
 795
 796         v  = (u_int64_t)p[0] << 56;
 797         v |= (u_int64_t)p[1] << 48;
 798         v |= (u_int64_t)p[2] << 40;
 799         v |= (u_int64_t)p[3] << 32;
 800         v |= (u_int64_t)p[4] << 24;
 801         v |= (u_int64_t)p[5] << 16;
 802         v |= (u_int64_t)p[6] << 8;
 803         v |= (u_int64_t)p[7];
 804
 805         return (v);
 806 }
 807
 808 u_int32_t
 809 get_u32(const void *vp)
 810 {
 811         const u_char *p = (const u_char *)vp;
 812         u_int32_t v;
 813
 814         v  = (u_int32_t)p[0] << 24;
 815         v |= (u_int32_t)p[1] << 16;
 816         v |= (u_int32_t)p[2] << 8;
 817         v |= (u_int32_t)p[3];
 818
 819         return (v);
 820 }
 821
 822 u_int16_t
 823 get_u16(const void *vp)
 824 {
 825         const u_char *p = (const u_char *)vp;
 826         u_int16_t v;
 827
 828         v  = (u_int16_t)p[0] << 8;
 829         v |= (u_int16_t)p[1];
 830
 831         return (v);
 832 }
 833
 834 void
 835 put_u64(void *vp, u_int64_t v)
 836 {
 837         u_char *p = (u_char *)vp;
 838
 839         p[0] = (u_char)(v >> 56) & 0xff;
 840         p[1] = (u_char)(v >> 48) & 0xff;
 841         p[2] = (u_char)(v >> 40) & 0xff;
 842         p[3] = (u_char)(v >> 32) & 0xff;
 843         p[4] = (u_char)(v >> 24) & 0xff;
 844         p[5] = (u_char)(v >> 16) & 0xff;
 845         p[6] = (u_char)(v >> 8) & 0xff;
 846         p[7] = (u_char)v & 0xff;
 847 }
 848
 849 void
 850 put_u32(void *vp, u_int32_t v)
 851 {
 852         u_char *p = (u_char *)vp;
 853
 854         p[0] = (u_char)(v >> 24) & 0xff;
 855         p[1] = (u_char)(v >> 16) & 0xff;
 856         p[2] = (u_char)(v >> 8) & 0xff;
 857         p[3] = (u_char)v & 0xff;
 858 }
 859
 860
 861 void
 862 put_u16(void *vp, u_int16_t v)
 863 {
 864         u_char *p = (u_char *)vp;
 865
 866         p[0] = (u_char)(v >> 8) & 0xff;
 867         p[1] = (u_char)v & 0xff;
 868 }
 869
 870 void
 871 ms_subtract_diff(struct timeval *start, int *ms)
 872 {
 873         struct timeval diff, finish;
 874
 875         gettimeofday(&finish, NULL);
 876         timersub(&finish, start, &diff);
 877         *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
 878 }
 879
 880 void
 881 ms_to_timeval(struct timeval *tv, int ms)
 882 {
 883         if (ms < 0)
 884                 ms = 0;
 885         tv->tv_sec = ms / 1000;
 886         tv->tv_usec = (ms % 1000) * 1000;
 887 }
 888
 889 void
 890 sock_set_v6only(int s)
 891 {
 892 #ifdef IPV6_V6ONLY
 893         int on = 1;
 894
 895         debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
 896         if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
 897                 error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
 898 #endif
 899 }