crypto/openssh/misc.c

   1 /* $OpenBSD: misc.c,v 1.71 2009/02/21 19:32:04 tobias 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 /* Characters considered whitespace in strsep calls. */
 155 #define WHITESPACE " \t\r\n"
 156 #define QUOTE   "\""
 157
 158 /* return next token in configuration line */
 159 char *
 160 strdelim(char **s)
 161 {
 162         char *old;
 163         int wspace = 0;
 164
 165         if (*s == NULL)
 166                 return NULL;
 167
 168         old = *s;
 169
 170         *s = strpbrk(*s, WHITESPACE QUOTE "=");
 171         if (*s == NULL)
 172                 return (old);
 173
 174         if (*s[0] == '\"') {
 175                 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
 176                 /* Find matching quote */
 177                 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
 178                         return (NULL);          /* no matching quote */
 179                 } else {
 180                         *s[0] = '\0';
 181                         return (old);
 182                 }
 183         }
 184
 185         /* Allow only one '=' to be skipped */
 186         if (*s[0] == '=')
 187                 wspace = 1;
 188         *s[0] = '\0';
 189
 190         /* Skip any extra whitespace after first token */
 191         *s += strspn(*s + 1, WHITESPACE) + 1;
 192         if (*s[0] == '=' && !wspace)
 193                 *s += strspn(*s + 1, WHITESPACE) + 1;
 194
 195         return (old);
 196 }
 197
 198 struct passwd *
 199 pwcopy(struct passwd *pw)
 200 {
 201         struct passwd *copy = xcalloc(1, sizeof(*copy));
 202
 203         copy->pw_name = xstrdup(pw->pw_name);
 204         copy->pw_passwd = xstrdup(pw->pw_passwd);
 205         copy->pw_gecos = xstrdup(pw->pw_gecos);
 206         copy->pw_uid = pw->pw_uid;
 207         copy->pw_gid = pw->pw_gid;
 208 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
 209         copy->pw_expire = pw->pw_expire;
 210 #endif
 211 #ifdef HAVE_PW_CHANGE_IN_PASSWD
 212         copy->pw_change = pw->pw_change;
 213 #endif
 214 #ifdef HAVE_PW_CLASS_IN_PASSWD
 215         copy->pw_class = xstrdup(pw->pw_class);
 216 #endif
 217         copy->pw_dir = xstrdup(pw->pw_dir);
 218         copy->pw_shell = xstrdup(pw->pw_shell);
 219         return copy;
 220 }
 221
 222 /*
 223  * Convert ASCII string to TCP/IP port number.
 224  * Port must be >=0 and <=65535.
 225  * Return -1 if invalid.
 226  */
 227 int
 228 a2port(const char *s)
 229 {
 230         long long port;
 231         const char *errstr;
 232
 233         port = strtonum(s, 0, 65535, &errstr);
 234         if (errstr != NULL)
 235                 return -1;
 236         return (int)port;
 237 }
 238
 239 int
 240 a2tun(const char *s, int *remote)
 241 {
 242         const char *errstr = NULL;
 243         char *sp, *ep;
 244         int tun;
 245
 246         if (remote != NULL) {
 247                 *remote = SSH_TUNID_ANY;
 248                 sp = xstrdup(s);
 249                 if ((ep = strchr(sp, ':')) == NULL) {
 250                         xfree(sp);
 251                         return (a2tun(s, NULL));
 252                 }
 253                 ep[0] = '\0'; ep++;
 254                 *remote = a2tun(ep, NULL);
 255                 tun = a2tun(sp, NULL);
 256                 xfree(sp);
 257                 return (*remote == SSH_TUNID_ERR ? *remote : tun);
 258         }
 259
 260         if (strcasecmp(s, "any") == 0)
 261                 return (SSH_TUNID_ANY);
 262
 263         tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
 264         if (errstr != NULL)
 265                 return (SSH_TUNID_ERR);
 266
 267         return (tun);
 268 }
 269
 270 #define SECONDS         1
 271 #define MINUTES         (SECONDS * 60)
 272 #define HOURS           (MINUTES * 60)
 273 #define DAYS            (HOURS * 24)
 274 #define WEEKS           (DAYS * 7)
 275
 276 /*
 277  * Convert a time string into seconds; format is
 278  * a sequence of:
 279  *      time[qualifier]
 280  *
 281  * Valid time qualifiers are:
 282  *      <none>  seconds
 283  *      s|S     seconds
 284  *      m|M     minutes
 285  *      h|H     hours
 286  *      d|D     days
 287  *      w|W     weeks
 288  *
 289  * Examples:
 290  *      90m     90 minutes
 291  *      1h30m   90 minutes
 292  *      2d      2 days
 293  *      1w      1 week
 294  *
 295  * Return -1 if time string is invalid.
 296  */
 297 long
 298 convtime(const char *s)
 299 {
 300         long total, secs;
 301         const char *p;
 302         char *endp;
 303
 304         errno = 0;
 305         total = 0;
 306         p = s;
 307
 308         if (p == NULL || *p == '\0')
 309                 return -1;
 310
 311         while (*p) {
 312                 secs = strtol(p, &endp, 10);
 313                 if (p == endp ||
 314                     (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
 315                     secs < 0)
 316                         return -1;
 317
 318                 switch (*endp++) {
 319                 case '\0':
 320                         endp--;
 321                         break;
 322                 case 's':
 323                 case 'S':
 324                         break;
 325                 case 'm':
 326                 case 'M':
 327                         secs *= MINUTES;
 328                         break;
 329                 case 'h':
 330                 case 'H':
 331                         secs *= HOURS;
 332                         break;
 333                 case 'd':
 334                 case 'D':
 335                         secs *= DAYS;
 336                         break;
 337                 case 'w':
 338                 case 'W':
 339                         secs *= WEEKS;
 340                         break;
 341                 default:
 342                         return -1;
 343                 }
 344                 total += secs;
 345                 if (total < 0)
 346                         return -1;
 347                 p = endp;
 348         }
 349
 350         return total;
 351 }
 352
 353 /*
 354  * Returns a standardized host+port identifier string.
 355  * Caller must free returned string.
 356  */
 357 char *
 358 put_host_port(const char *host, u_short port)
 359 {
 360         char *hoststr;
 361
 362         if (port == 0 || port == SSH_DEFAULT_PORT)
 363                 return(xstrdup(host));
 364         if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
 365                 fatal("put_host_port: asprintf: %s", strerror(errno));
 366         debug3("put_host_port: %s", hoststr);
 367         return hoststr;
 368 }
 369
 370 /*
 371  * Search for next delimiter between hostnames/addresses and ports.
 372  * Argument may be modified (for termination).
 373  * Returns *cp if parsing succeeds.
 374  * *cp is set to the start of the next delimiter, if one was found.
 375  * If this is the last field, *cp is set to NULL.
 376  */
 377 char *
 378 hpdelim(char **cp)
 379 {
 380         char *s, *old;
 381
 382         if (cp == NULL || *cp == NULL)
 383                 return NULL;
 384
 385         old = s = *cp;
 386         if (*s == '[') {
 387                 if ((s = strchr(s, ']')) == NULL)
 388                         return NULL;
 389                 else
 390                         s++;
 391         } else if ((s = strpbrk(s, ":/")) == NULL)
 392                 s = *cp + strlen(*cp); /* skip to end (see first case below) */
 393
 394         switch (*s) {
 395         case '\0':
 396                 *cp = NULL;     /* no more fields*/
 397                 break;
 398
 399         case ':':
 400         case '/':
 401                 *s = '\0';      /* terminate */
 402                 *cp = s + 1;
 403                 break;
 404
 405         default:
 406                 return NULL;
 407         }
 408
 409         return old;
 410 }
 411
 412 char *
 413 cleanhostname(char *host)
 414 {
 415         if (*host == '[' && host[strlen(host) - 1] == ']') {
 416                 host[strlen(host) - 1] = '\0';
 417                 return (host + 1);
 418         } else
 419                 return host;
 420 }
 421
 422 char *
 423 colon(char *cp)
 424 {
 425         int flag = 0;
 426
 427         if (*cp == ':')         /* Leading colon is part of file name. */
 428                 return (0);
 429         if (*cp == '[')
 430                 flag = 1;
 431
 432         for (; *cp; ++cp) {
 433                 if (*cp == '@' && *(cp+1) == '[')
 434                         flag = 1;
 435                 if (*cp == ']' && *(cp+1) == ':' && flag)
 436                         return (cp+1);
 437                 if (*cp == ':' && !flag)
 438                         return (cp);
 439                 if (*cp == '/')
 440                         return (0);
 441         }
 442         return (0);
 443 }
 444
 445 /* function to assist building execv() arguments */
 446 void
 447 addargs(arglist *args, char *fmt, ...)
 448 {
 449         va_list ap;
 450         char *cp;
 451         u_int nalloc;
 452         int r;
 453
 454         va_start(ap, fmt);
 455         r = vasprintf(&cp, fmt, ap);
 456         va_end(ap);
 457         if (r == -1)
 458                 fatal("addargs: argument too long");
 459
 460         nalloc = args->nalloc;
 461         if (args->list == NULL) {
 462                 nalloc = 32;
 463                 args->num = 0;
 464         } else if (args->num+2 >= nalloc)
 465                 nalloc *= 2;
 466
 467         args->list = xrealloc(args->list, nalloc, sizeof(char *));
 468         args->nalloc = nalloc;
 469         args->list[args->num++] = cp;
 470         args->list[args->num] = NULL;
 471 }
 472
 473 void
 474 replacearg(arglist *args, u_int which, char *fmt, ...)
 475 {
 476         va_list ap;
 477         char *cp;
 478         int r;
 479
 480         va_start(ap, fmt);
 481         r = vasprintf(&cp, fmt, ap);
 482         va_end(ap);
 483         if (r == -1)
 484                 fatal("replacearg: argument too long");
 485
 486         if (which >= args->num)
 487                 fatal("replacearg: tried to replace invalid arg %d >= %d",
 488                     which, args->num);
 489         xfree(args->list[which]);
 490         args->list[which] = cp;
 491 }
 492
 493 void
 494 freeargs(arglist *args)
 495 {
 496         u_int i;
 497
 498         if (args->list != NULL) {
 499                 for (i = 0; i < args->num; i++)
 500                         xfree(args->list[i]);
 501                 xfree(args->list);
 502                 args->nalloc = args->num = 0;
 503                 args->list = NULL;
 504         }
 505 }
 506
 507 /*
 508  * Expands tildes in the file name.  Returns data allocated by xmalloc.
 509  * Warning: this calls getpw*.
 510  */
 511 char *
 512 tilde_expand_filename(const char *filename, uid_t uid)
 513 {
 514         const char *path;
 515         char user[128], ret[MAXPATHLEN];
 516         struct passwd *pw;
 517         u_int len, slash;
 518
 519         if (*filename != '~')
 520                 return (xstrdup(filename));
 521         filename++;
 522
 523         path = strchr(filename, '/');
 524         if (path != NULL && path > filename) {          /* ~user/path */
 525                 slash = path - filename;
 526                 if (slash > sizeof(user) - 1)
 527                         fatal("tilde_expand_filename: ~username too long");
 528                 memcpy(user, filename, slash);
 529                 user[slash] = '\0';
 530                 if ((pw = getpwnam(user)) == NULL)
 531                         fatal("tilde_expand_filename: No such user %s", user);
 532         } else if ((pw = getpwuid(uid)) == NULL)        /* ~/path */
 533                 fatal("tilde_expand_filename: No such uid %ld", (long)uid);
 534
 535         if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
 536                 fatal("tilde_expand_filename: Path too long");
 537
 538         /* Make sure directory has a trailing '/' */
 539         len = strlen(pw->pw_dir);
 540         if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
 541             strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
 542                 fatal("tilde_expand_filename: Path too long");
 543
 544         /* Skip leading '/' from specified path */
 545         if (path != NULL)
 546                 filename = path + 1;
 547         if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
 548                 fatal("tilde_expand_filename: Path too long");
 549
 550         return (xstrdup(ret));
 551 }
 552
 553 /*
 554  * Expand a string with a set of %[char] escapes. A number of escapes may be
 555  * specified as (char *escape_chars, char *replacement) pairs. The list must
 556  * be terminated by a NULL escape_char. Returns replaced string in memory
 557  * allocated by xmalloc.
 558  */
 559 char *
 560 percent_expand(const char *string, ...)
 561 {
 562 #define EXPAND_MAX_KEYS 16
 563         struct {
 564                 const char *key;
 565                 const char *repl;
 566         } keys[EXPAND_MAX_KEYS];
 567         u_int num_keys, i, j;
 568         char buf[4096];
 569         va_list ap;
 570
 571         /* Gather keys */
 572         va_start(ap, string);
 573         for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
 574                 keys[num_keys].key = va_arg(ap, char *);
 575                 if (keys[num_keys].key == NULL)
 576                         break;
 577                 keys[num_keys].repl = va_arg(ap, char *);
 578                 if (keys[num_keys].repl == NULL)
 579                         fatal("percent_expand: NULL replacement");
 580         }
 581         va_end(ap);
 582
 583         if (num_keys >= EXPAND_MAX_KEYS)
 584                 fatal("percent_expand: too many keys");
 585
 586         /* Expand string */
 587         *buf = '\0';
 588         for (i = 0; *string != '\0'; string++) {
 589                 if (*string != '%') {
 590  append:
 591                         buf[i++] = *string;
 592                         if (i >= sizeof(buf))
 593                                 fatal("percent_expand: string too long");
 594                         buf[i] = '\0';
 595                         continue;
 596                 }
 597                 string++;
 598                 if (*string == '%')
 599                         goto append;
 600                 for (j = 0; j < num_keys; j++) {
 601                         if (strchr(keys[j].key, *string) != NULL) {
 602                                 i = strlcat(buf, keys[j].repl, sizeof(buf));
 603                                 if (i >= sizeof(buf))
 604                                         fatal("percent_expand: string too long");
 605                                 break;
 606                         }
 607                 }
 608                 if (j >= num_keys)
 609                         fatal("percent_expand: unknown key %%%c", *string);
 610         }
 611         return (xstrdup(buf));
 612 #undef EXPAND_MAX_KEYS
 613 }
 614
 615 /*
 616  * Read an entire line from a public key file into a static buffer, discarding
 617  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 618  */
 619 int
 620 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 621    u_long *lineno)
 622 {
 623         while (fgets(buf, bufsz, f) != NULL) {
 624                 if (buf[0] == '\0')
 625                         continue;
 626                 (*lineno)++;
 627                 if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
 628                         return 0;
 629                 } else {
 630                         debug("%s: %s line %lu exceeds size limit", __func__,
 631                             filename, *lineno);
 632                         /* discard remainder of line */
 633                         while (fgetc(f) != '\n' && !feof(f))
 634                                 ;       /* nothing */
 635                 }
 636         }
 637         return -1;
 638 }
 639
 640 int
 641 tun_open(int tun, int mode)
 642 {
 643 #if defined(CUSTOM_SYS_TUN_OPEN)
 644         return (sys_tun_open(tun, mode));
 645 #elif defined(SSH_TUN_OPENBSD)
 646         struct ifreq ifr;
 647         char name[100];
 648         int fd = -1, sock;
 649
 650         /* Open the tunnel device */
 651         if (tun <= SSH_TUNID_MAX) {
 652                 snprintf(name, sizeof(name), "/dev/tun%d", tun);
 653                 fd = open(name, O_RDWR);
 654         } else if (tun == SSH_TUNID_ANY) {
 655                 for (tun = 100; tun >= 0; tun--) {
 656                         snprintf(name, sizeof(name), "/dev/tun%d", tun);
 657                         if ((fd = open(name, O_RDWR)) >= 0)
 658                                 break;
 659                 }
 660         } else {
 661                 debug("%s: invalid tunnel %u", __func__, tun);
 662                 return (-1);
 663         }
 664
 665         if (fd < 0) {
 666                 debug("%s: %s open failed: %s", __func__, name, strerror(errno));
 667                 return (-1);
 668         }
 669
 670         debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 671
 672         /* Set the tunnel device operation mode */
 673         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
 674         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
 675                 goto failed;
 676
 677         if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
 678                 goto failed;
 679
 680         /* Set interface mode */
 681         ifr.ifr_flags &= ~IFF_UP;
 682         if (mode == SSH_TUNMODE_ETHERNET)
 683                 ifr.ifr_flags |= IFF_LINK0;
 684         else
 685                 ifr.ifr_flags &= ~IFF_LINK0;
 686         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 687                 goto failed;
 688
 689         /* Bring interface up */
 690         ifr.ifr_flags |= IFF_UP;
 691         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 692                 goto failed;
 693
 694         close(sock);
 695         return (fd);
 696
 697  failed:
 698         if (fd >= 0)
 699                 close(fd);
 700         if (sock >= 0)
 701                 close(sock);
 702         debug("%s: failed to set %s mode %d: %s", __func__, name,
 703             mode, strerror(errno));
 704         return (-1);
 705 #else
 706         error("Tunnel interfaces are not supported on this platform");
 707         return (-1);
 708 #endif
 709 }
 710
 711 void
 712 sanitise_stdfd(void)
 713 {
 714         int nullfd, dupfd;
 715
 716         if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
 717                 fprintf(stderr, "Couldn't open /dev/null: %s\n",
 718                     strerror(errno));
 719                 exit(1);
 720         }
 721         while (++dupfd <= 2) {
 722                 /* Only clobber closed fds */
 723                 if (fcntl(dupfd, F_GETFL, 0) >= 0)
 724                         continue;
 725                 if (dup2(nullfd, dupfd) == -1) {
 726                         fprintf(stderr, "dup2: %s\n", strerror(errno));
 727                         exit(1);
 728                 }
 729         }
 730         if (nullfd > 2)
 731                 close(nullfd);
 732 }
 733
 734 char *
 735 tohex(const void *vp, size_t l)
 736 {
 737         const u_char *p = (const u_char *)vp;
 738         char b[3], *r;
 739         size_t i, hl;
 740
 741         if (l > 65536)
 742                 return xstrdup("tohex: length > 65536");
 743
 744         hl = l * 2 + 1;
 745         r = xcalloc(1, hl);
 746         for (i = 0; i < l; i++) {
 747                 snprintf(b, sizeof(b), "%02x", p[i]);
 748                 strlcat(r, b, hl);
 749         }
 750         return (r);
 751 }
 752
 753 u_int64_t
 754 get_u64(const void *vp)
 755 {
 756         const u_char *p = (const u_char *)vp;
 757         u_int64_t v;
 758
 759         v  = (u_int64_t)p[0] << 56;
 760         v |= (u_int64_t)p[1] << 48;
 761         v |= (u_int64_t)p[2] << 40;
 762         v |= (u_int64_t)p[3] << 32;
 763         v |= (u_int64_t)p[4] << 24;
 764         v |= (u_int64_t)p[5] << 16;
 765         v |= (u_int64_t)p[6] << 8;
 766         v |= (u_int64_t)p[7];
 767
 768         return (v);
 769 }
 770
 771 u_int32_t
 772 get_u32(const void *vp)
 773 {
 774         const u_char *p = (const u_char *)vp;
 775         u_int32_t v;
 776
 777         v  = (u_int32_t)p[0] << 24;
 778         v |= (u_int32_t)p[1] << 16;
 779         v |= (u_int32_t)p[2] << 8;
 780         v |= (u_int32_t)p[3];
 781
 782         return (v);
 783 }
 784
 785 u_int16_t
 786 get_u16(const void *vp)
 787 {
 788         const u_char *p = (const u_char *)vp;
 789         u_int16_t v;
 790
 791         v  = (u_int16_t)p[0] << 8;
 792         v |= (u_int16_t)p[1];
 793
 794         return (v);
 795 }
 796
 797 void
 798 put_u64(void *vp, u_int64_t v)
 799 {
 800         u_char *p = (u_char *)vp;
 801
 802         p[0] = (u_char)(v >> 56) & 0xff;
 803         p[1] = (u_char)(v >> 48) & 0xff;
 804         p[2] = (u_char)(v >> 40) & 0xff;
 805         p[3] = (u_char)(v >> 32) & 0xff;
 806         p[4] = (u_char)(v >> 24) & 0xff;
 807         p[5] = (u_char)(v >> 16) & 0xff;
 808         p[6] = (u_char)(v >> 8) & 0xff;
 809         p[7] = (u_char)v & 0xff;
 810 }
 811
 812 void
 813 put_u32(void *vp, u_int32_t v)
 814 {
 815         u_char *p = (u_char *)vp;
 816
 817         p[0] = (u_char)(v >> 24) & 0xff;
 818         p[1] = (u_char)(v >> 16) & 0xff;
 819         p[2] = (u_char)(v >> 8) & 0xff;
 820         p[3] = (u_char)v & 0xff;
 821 }
 822
 823
 824 void
 825 put_u16(void *vp, u_int16_t v)
 826 {
 827         u_char *p = (u_char *)vp;
 828
 829         p[0] = (u_char)(v >> 8) & 0xff;
 830         p[1] = (u_char)v & 0xff;
 831 }
 832
 833 void
 834 ms_subtract_diff(struct timeval *start, int *ms)
 835 {
 836         struct timeval diff, finish;
 837
 838         gettimeofday(&finish, NULL);
 839         timersub(&finish, start, &diff);
 840         *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
 841 }
 842
 843 void
 844 ms_to_timeval(struct timeval *tv, int ms)
 845 {
 846         if (ms < 0)
 847                 ms = 0;
 848         tv->tv_sec = ms / 1000;
 849         tv->tv_usec = (ms % 1000) * 1000;
 850 }
 851