misc.c

   1 /* $OpenBSD: misc.c,v 1.65 2006/11/23 01:35:11 ray 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 #ifdef HAVE_PATHS_H
  46 # include <paths.h>
  47 #include <pwd.h>
  48 #endif
  49 #ifdef SSH_TUN_OPENBSD
  50 #include <net/if.h>
  51 #endif
  52
  53 #include "xmalloc.h"
  54 #include "misc.h"
  55 #include "log.h"
  56 #include "ssh.h"
  57
  58 /* remove newline at end of string */
  59 char *
  60 chop(char *s)
  61 {
  62         char *t = s;
  63         while (*t) {
  64                 if (*t == '\n' || *t == '\r') {
  65                         *t = '\0';
  66                         return s;
  67                 }
  68                 t++;
  69         }
  70         return s;
  71
  72 }
  73
  74 /* set/unset filedescriptor to non-blocking */
  75 int
  76 set_nonblock(int fd)
  77 {
  78         int val;
  79
  80         val = fcntl(fd, F_GETFL, 0);
  81         if (val < 0) {
  82                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
  83                 return (-1);
  84         }
  85         if (val & O_NONBLOCK) {
  86                 debug3("fd %d is O_NONBLOCK", fd);
  87                 return (0);
  88         }
  89         debug2("fd %d setting O_NONBLOCK", fd);
  90         val |= O_NONBLOCK;
  91         if (fcntl(fd, F_SETFL, val) == -1) {
  92                 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
  93                     strerror(errno));
  94                 return (-1);
  95         }
  96         return (0);
  97 }
  98
  99 int
 100 unset_nonblock(int fd)
 101 {
 102         int val;
 103
 104         val = fcntl(fd, F_GETFL, 0);
 105         if (val < 0) {
 106                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
 107                 return (-1);
 108         }
 109         if (!(val & O_NONBLOCK)) {
 110                 debug3("fd %d is not O_NONBLOCK", fd);
 111                 return (0);
 112         }
 113         debug("fd %d clearing O_NONBLOCK", fd);
 114         val &= ~O_NONBLOCK;
 115         if (fcntl(fd, F_SETFL, val) == -1) {
 116                 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
 117                     fd, strerror(errno));
 118                 return (-1);
 119         }
 120         return (0);
 121 }
 122
 123 /* disable nagle on socket */
 124 void
 125 set_nodelay(int fd)
 126 {
 127         int opt;
 128         socklen_t optlen;
 129
 130         optlen = sizeof opt;
 131         if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
 132                 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
 133                 return;
 134         }
 135         if (opt == 1) {
 136                 debug2("fd %d is TCP_NODELAY", fd);
 137                 return;
 138         }
 139         opt = 1;
 140         debug2("fd %d setting TCP_NODELAY", fd);
 141         if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
 142                 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
 143 }
 144
 145 /* Characters considered whitespace in strsep calls. */
 146 #define WHITESPACE " \t\r\n"
 147 #define QUOTE   "\""
 148
 149 /* return next token in configuration line */
 150 char *
 151 strdelim(char **s)
 152 {
 153         char *old;
 154         int wspace = 0;
 155
 156         if (*s == NULL)
 157                 return NULL;
 158
 159         old = *s;
 160
 161         *s = strpbrk(*s, WHITESPACE QUOTE "=");
 162         if (*s == NULL)
 163                 return (old);
 164
 165         if (*s[0] == '\"') {
 166                 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
 167                 /* Find matching quote */
 168                 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
 169                         return (NULL);          /* no matching quote */
 170                 } else {
 171                         *s[0] = '\0';
 172                         return (old);
 173                 }
 174         }
 175
 176         /* Allow only one '=' to be skipped */
 177         if (*s[0] == '=')
 178                 wspace = 1;
 179         *s[0] = '\0';
 180
 181         /* Skip any extra whitespace after first token */
 182         *s += strspn(*s + 1, WHITESPACE) + 1;
 183         if (*s[0] == '=' && !wspace)
 184                 *s += strspn(*s + 1, WHITESPACE) + 1;
 185
 186         return (old);
 187 }
 188
 189 struct passwd *
 190 pwcopy(struct passwd *pw)
 191 {
 192         struct passwd *copy = xcalloc(1, sizeof(*copy));
 193
 194         copy->pw_name = xstrdup(pw->pw_name);
 195         copy->pw_passwd = xstrdup(pw->pw_passwd);
 196         copy->pw_gecos = xstrdup(pw->pw_gecos);
 197         copy->pw_uid = pw->pw_uid;
 198         copy->pw_gid = pw->pw_gid;
 199 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
 200         copy->pw_expire = pw->pw_expire;
 201 #endif
 202 #ifdef HAVE_PW_CHANGE_IN_PASSWD
 203         copy->pw_change = pw->pw_change;
 204 #endif
 205 #ifdef HAVE_PW_CLASS_IN_PASSWD
 206         copy->pw_class = xstrdup(pw->pw_class);
 207 #endif
 208         copy->pw_dir = xstrdup(pw->pw_dir);
 209         copy->pw_shell = xstrdup(pw->pw_shell);
 210         return copy;
 211 }
 212
 213 /*
 214  * Convert ASCII string to TCP/IP port number.
 215  * Port must be >0 and <=65535.
 216  * Return 0 if invalid.
 217  */
 218 int
 219 a2port(const char *s)
 220 {
 221         long port;
 222         char *endp;
 223
 224         errno = 0;
 225         port = strtol(s, &endp, 0);
 226         if (s == endp || *endp != '\0' ||
 227             (errno == ERANGE && (port == LONG_MIN || port == LONG_MAX)) ||
 228             port <= 0 || port > 65535)
 229                 return 0;
 230
 231         return port;
 232 }
 233
 234 int
 235 a2tun(const char *s, int *remote)
 236 {
 237         const char *errstr = NULL;
 238         char *sp, *ep;
 239         int tun;
 240
 241         if (remote != NULL) {
 242                 *remote = SSH_TUNID_ANY;
 243                 sp = xstrdup(s);
 244                 if ((ep = strchr(sp, ':')) == NULL) {
 245                         xfree(sp);
 246                         return (a2tun(s, NULL));
 247                 }
 248                 ep[0] = '\0'; ep++;
 249                 *remote = a2tun(ep, NULL);
 250                 tun = a2tun(sp, NULL);
 251                 xfree(sp);
 252                 return (*remote == SSH_TUNID_ERR ? *remote : tun);
 253         }
 254
 255         if (strcasecmp(s, "any") == 0)
 256                 return (SSH_TUNID_ANY);
 257
 258         tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
 259         if (errstr != NULL)
 260                 return (SSH_TUNID_ERR);
 261
 262         return (tun);
 263 }
 264
 265 #define SECONDS         1
 266 #define MINUTES         (SECONDS * 60)
 267 #define HOURS           (MINUTES * 60)
 268 #define DAYS            (HOURS * 24)
 269 #define WEEKS           (DAYS * 7)
 270
 271 /*
 272  * Convert a time string into seconds; format is
 273  * a sequence of:
 274  *      time[qualifier]
 275  *
 276  * Valid time qualifiers are:
 277  *      <none>  seconds
 278  *      s|S     seconds
 279  *      m|M     minutes
 280  *      h|H     hours
 281  *      d|D     days
 282  *      w|W     weeks
 283  *
 284  * Examples:
 285  *      90m     90 minutes
 286  *      1h30m   90 minutes
 287  *      2d      2 days
 288  *      1w      1 week
 289  *
 290  * Return -1 if time string is invalid.
 291  */
 292 long
 293 convtime(const char *s)
 294 {
 295         long total, secs;
 296         const char *p;
 297         char *endp;
 298
 299         errno = 0;
 300         total = 0;
 301         p = s;
 302
 303         if (p == NULL || *p == '\0')
 304                 return -1;
 305
 306         while (*p) {
 307                 secs = strtol(p, &endp, 10);
 308                 if (p == endp ||
 309                     (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
 310                     secs < 0)
 311                         return -1;
 312
 313                 switch (*endp++) {
 314                 case '\0':
 315                         endp--;
 316                         break;
 317                 case 's':
 318                 case 'S':
 319                         break;
 320                 case 'm':
 321                 case 'M':
 322                         secs *= MINUTES;
 323                         break;
 324                 case 'h':
 325                 case 'H':
 326                         secs *= HOURS;
 327                         break;
 328                 case 'd':
 329                 case 'D':
 330                         secs *= DAYS;
 331                         break;
 332                 case 'w':
 333                 case 'W':
 334                         secs *= WEEKS;
 335                         break;
 336                 default:
 337                         return -1;
 338                 }
 339                 total += secs;
 340                 if (total < 0)
 341                         return -1;
 342                 p = endp;
 343         }
 344
 345         return total;
 346 }
 347
 348 /*
 349  * Returns a standardized host+port identifier string.
 350  * Caller must free returned string.
 351  */
 352 char *
 353 put_host_port(const char *host, u_short port)
 354 {
 355         char *hoststr;
 356
 357         if (port == 0 || port == SSH_DEFAULT_PORT)
 358                 return(xstrdup(host));
 359         if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
 360                 fatal("put_host_port: asprintf: %s", strerror(errno));
 361         debug3("put_host_port: %s", hoststr);
 362         return hoststr;
 363 }
 364
 365 /*
 366  * Search for next delimiter between hostnames/addresses and ports.
 367  * Argument may be modified (for termination).
 368  * Returns *cp if parsing succeeds.
 369  * *cp is set to the start of the next delimiter, if one was found.
 370  * If this is the last field, *cp is set to NULL.
 371  */
 372 char *
 373 hpdelim(char **cp)
 374 {
 375         char *s, *old;
 376
 377         if (cp == NULL || *cp == NULL)
 378                 return NULL;
 379
 380         old = s = *cp;
 381         if (*s == '[') {
 382                 if ((s = strchr(s, ']')) == NULL)
 383                         return NULL;
 384                 else
 385                         s++;
 386         } else if ((s = strpbrk(s, ":/")) == NULL)
 387                 s = *cp + strlen(*cp); /* skip to end (see first case below) */
 388
 389         switch (*s) {
 390         case '\0':
 391                 *cp = NULL;     /* no more fields*/
 392                 break;
 393
 394         case ':':
 395         case '/':
 396                 *s = '\0';      /* terminate */
 397                 *cp = s + 1;
 398                 break;
 399
 400         default:
 401                 return NULL;
 402         }
 403
 404         return old;
 405 }
 406
 407 char *
 408 cleanhostname(char *host)
 409 {
 410         if (*host == '[' && host[strlen(host) - 1] == ']') {
 411                 host[strlen(host) - 1] = '\0';
 412                 return (host + 1);
 413         } else
 414                 return host;
 415 }
 416
 417 char *
 418 colon(char *cp)
 419 {
 420         int flag = 0;
 421
 422         if (*cp == ':')         /* Leading colon is part of file name. */
 423                 return (0);
 424         if (*cp == '[')
 425                 flag = 1;
 426
 427         for (; *cp; ++cp) {
 428                 if (*cp == '@' && *(cp+1) == '[')
 429                         flag = 1;
 430                 if (*cp == ']' && *(cp+1) == ':' && flag)
 431                         return (cp+1);
 432                 if (*cp == ':' && !flag)
 433                         return (cp);
 434                 if (*cp == '/')
 435                         return (0);
 436         }
 437         return (0);
 438 }
 439
 440 /* function to assist building execv() arguments */
 441 void
 442 addargs(arglist *args, char *fmt, ...)
 443 {
 444         va_list ap;
 445         char *cp;
 446         u_int nalloc;
 447         int r;
 448
 449         va_start(ap, fmt);
 450         r = vasprintf(&cp, fmt, ap);
 451         va_end(ap);
 452         if (r == -1)
 453                 fatal("addargs: argument too long");
 454
 455         nalloc = args->nalloc;
 456         if (args->list == NULL) {
 457                 nalloc = 32;
 458                 args->num = 0;
 459         } else if (args->num+2 >= nalloc)
 460                 nalloc *= 2;
 461
 462         args->list = xrealloc(args->list, nalloc, sizeof(char *));
 463         args->nalloc = nalloc;
 464         args->list[args->num++] = cp;
 465         args->list[args->num] = NULL;
 466 }
 467
 468 void
 469 replacearg(arglist *args, u_int which, char *fmt, ...)
 470 {
 471         va_list ap;
 472         char *cp;
 473         int r;
 474
 475         va_start(ap, fmt);
 476         r = vasprintf(&cp, fmt, ap);
 477         va_end(ap);
 478         if (r == -1)
 479                 fatal("replacearg: argument too long");
 480
 481         if (which >= args->num)
 482                 fatal("replacearg: tried to replace invalid arg %d >= %d",
 483                     which, args->num);
 484         xfree(args->list[which]);
 485         args->list[which] = cp;
 486 }
 487
 488 void
 489 freeargs(arglist *args)
 490 {
 491         u_int i;
 492
 493         if (args->list != NULL) {
 494                 for (i = 0; i < args->num; i++)
 495                         xfree(args->list[i]);
 496                 xfree(args->list);
 497                 args->nalloc = args->num = 0;
 498                 args->list = NULL;
 499         }
 500 }
 501
 502 /*
 503  * Expands tildes in the file name.  Returns data allocated by xmalloc.
 504  * Warning: this calls getpw*.
 505  */
 506 char *
 507 tilde_expand_filename(const char *filename, uid_t uid)
 508 {
 509         const char *path;
 510         char user[128], ret[MAXPATHLEN];
 511         struct passwd *pw;
 512         u_int len, slash;
 513
 514         if (*filename != '~')
 515                 return (xstrdup(filename));
 516         filename++;
 517
 518         path = strchr(filename, '/');
 519         if (path != NULL && path > filename) {          /* ~user/path */
 520                 slash = path - filename;
 521                 if (slash > sizeof(user) - 1)
 522                         fatal("tilde_expand_filename: ~username too long");
 523                 memcpy(user, filename, slash);
 524                 user[slash] = '\0';
 525                 if ((pw = getpwnam(user)) == NULL)
 526                         fatal("tilde_expand_filename: No such user %s", user);
 527         } else if ((pw = getpwuid(uid)) == NULL)        /* ~/path */
 528                 fatal("tilde_expand_filename: No such uid %d", uid);
 529
 530         if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
 531                 fatal("tilde_expand_filename: Path too long");
 532
 533         /* Make sure directory has a trailing '/' */
 534         len = strlen(pw->pw_dir);
 535         if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
 536             strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
 537                 fatal("tilde_expand_filename: Path too long");
 538
 539         /* Skip leading '/' from specified path */
 540         if (path != NULL)
 541                 filename = path + 1;
 542         if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
 543                 fatal("tilde_expand_filename: Path too long");
 544
 545         return (xstrdup(ret));
 546 }
 547
 548 /*
 549  * Expand a string with a set of %[char] escapes. A number of escapes may be
 550  * specified as (char *escape_chars, char *replacement) pairs. The list must
 551  * be terminated by a NULL escape_char. Returns replaced string in memory
 552  * allocated by xmalloc.
 553  */
 554 char *
 555 percent_expand(const char *string, ...)
 556 {
 557 #define EXPAND_MAX_KEYS 16
 558         struct {
 559                 const char *key;
 560                 const char *repl;
 561         } keys[EXPAND_MAX_KEYS];
 562         u_int num_keys, i, j;
 563         char buf[4096];
 564         va_list ap;
 565
 566         /* Gather keys */
 567         va_start(ap, string);
 568         for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
 569                 keys[num_keys].key = va_arg(ap, char *);
 570                 if (keys[num_keys].key == NULL)
 571                         break;
 572                 keys[num_keys].repl = va_arg(ap, char *);
 573                 if (keys[num_keys].repl == NULL)
 574                         fatal("percent_expand: NULL replacement");
 575         }
 576         va_end(ap);
 577
 578         if (num_keys >= EXPAND_MAX_KEYS)
 579                 fatal("percent_expand: too many keys");
 580
 581         /* Expand string */
 582         *buf = '\0';
 583         for (i = 0; *string != '\0'; string++) {
 584                 if (*string != '%') {
 585  append:
 586                         buf[i++] = *string;
 587                         if (i >= sizeof(buf))
 588                                 fatal("percent_expand: string too long");
 589                         buf[i] = '\0';
 590                         continue;
 591                 }
 592                 string++;
 593                 if (*string == '%')
 594                         goto append;
 595                 for (j = 0; j < num_keys; j++) {
 596                         if (strchr(keys[j].key, *string) != NULL) {
 597                                 i = strlcat(buf, keys[j].repl, sizeof(buf));
 598                                 if (i >= sizeof(buf))
 599                                         fatal("percent_expand: string too long");
 600                                 break;
 601                         }
 602                 }
 603                 if (j >= num_keys)
 604                         fatal("percent_expand: unknown key %%%c", *string);
 605         }
 606         return (xstrdup(buf));
 607 #undef EXPAND_MAX_KEYS
 608 }
 609
 610 /*
 611  * Read an entire line from a public key file into a static buffer, discarding
 612  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 613  */
 614 int
 615 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 616    u_long *lineno)
 617 {
 618         while (fgets(buf, bufsz, f) != NULL) {
 619                 if (buf[0] == '\0')
 620                         continue;
 621                 (*lineno)++;
 622                 if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
 623                         return 0;
 624                 } else {
 625                         debug("%s: %s line %lu exceeds size limit", __func__,
 626                             filename, *lineno);
 627                         /* discard remainder of line */
 628                         while (fgetc(f) != '\n' && !feof(f))
 629                                 ;       /* nothing */
 630                 }
 631         }
 632         return -1;
 633 }
 634
 635 int
 636 tun_open(int tun, int mode)
 637 {
 638 #if defined(CUSTOM_SYS_TUN_OPEN)
 639         return (sys_tun_open(tun, mode));
 640 #elif defined(SSH_TUN_OPENBSD)
 641         struct ifreq ifr;
 642         char name[100];
 643         int fd = -1, sock;
 644
 645         /* Open the tunnel device */
 646         if (tun <= SSH_TUNID_MAX) {
 647                 snprintf(name, sizeof(name), "/dev/tun%d", tun);
 648                 fd = open(name, O_RDWR);
 649         } else if (tun == SSH_TUNID_ANY) {
 650                 for (tun = 100; tun >= 0; tun--) {
 651                         snprintf(name, sizeof(name), "/dev/tun%d", tun);
 652                         if ((fd = open(name, O_RDWR)) >= 0)
 653                                 break;
 654                 }
 655         } else {
 656                 debug("%s: invalid tunnel %u", __func__, tun);
 657                 return (-1);
 658         }
 659
 660         if (fd < 0) {
 661                 debug("%s: %s open failed: %s", __func__, name, strerror(errno));
 662                 return (-1);
 663         }
 664
 665         debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 666
 667         /* Set the tunnel device operation mode */
 668         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
 669         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
 670                 goto failed;
 671
 672         if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
 673                 goto failed;
 674
 675         /* Set interface mode */
 676         ifr.ifr_flags &= ~IFF_UP;
 677         if (mode == SSH_TUNMODE_ETHERNET)
 678                 ifr.ifr_flags |= IFF_LINK0;
 679         else
 680                 ifr.ifr_flags &= ~IFF_LINK0;
 681         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 682                 goto failed;
 683
 684         /* Bring interface up */
 685         ifr.ifr_flags |= IFF_UP;
 686         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 687                 goto failed;
 688
 689         close(sock);
 690         return (fd);
 691
 692  failed:
 693         if (fd >= 0)
 694                 close(fd);
 695         if (sock >= 0)
 696                 close(sock);
 697         debug("%s: failed to set %s mode %d: %s", __func__, name,
 698             mode, strerror(errno));
 699         return (-1);
 700 #else
 701         error("Tunnel interfaces are not supported on this platform");
 702         return (-1);
 703 #endif
 704 }
 705
 706 void
 707 sanitise_stdfd(void)
 708 {
 709         int nullfd, dupfd;
 710
 711         if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
 712                 fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
 713                 exit(1);
 714         }
 715         while (++dupfd <= 2) {
 716                 /* Only clobber closed fds */
 717                 if (fcntl(dupfd, F_GETFL, 0) >= 0)
 718                         continue;
 719                 if (dup2(nullfd, dupfd) == -1) {
 720                         fprintf(stderr, "dup2: %s", strerror(errno));
 721                         exit(1);
 722                 }
 723         }
 724         if (nullfd > 2)
 725                 close(nullfd);
 726 }
 727
 728 char *
 729 tohex(const void *vp, size_t l)
 730 {
 731         const u_char *p = (const u_char *)vp;
 732         char b[3], *r;
 733         size_t i, hl;
 734
 735         if (l > 65536)
 736                 return xstrdup("tohex: length > 65536");
 737
 738         hl = l * 2 + 1;
 739         r = xcalloc(1, hl);
 740         for (i = 0; i < l; i++) {
 741                 snprintf(b, sizeof(b), "%02x", p[i]);
 742                 strlcat(r, b, hl);
 743         }
 744         return (r);
 745 }
 746
 747 u_int64_t
 748 get_u64(const void *vp)
 749 {
 750         const u_char *p = (const u_char *)vp;
 751         u_int64_t v;
 752
 753         v  = (u_int64_t)p[0] << 56;
 754         v |= (u_int64_t)p[1] << 48;
 755         v |= (u_int64_t)p[2] << 40;
 756         v |= (u_int64_t)p[3] << 32;
 757         v |= (u_int64_t)p[4] << 24;
 758         v |= (u_int64_t)p[5] << 16;
 759         v |= (u_int64_t)p[6] << 8;
 760         v |= (u_int64_t)p[7];
 761
 762         return (v);
 763 }
 764
 765 u_int32_t
 766 get_u32(const void *vp)
 767 {
 768         const u_char *p = (const u_char *)vp;
 769         u_int32_t v;
 770
 771         v  = (u_int32_t)p[0] << 24;
 772         v |= (u_int32_t)p[1] << 16;
 773         v |= (u_int32_t)p[2] << 8;
 774         v |= (u_int32_t)p[3];
 775
 776         return (v);
 777 }
 778
 779 u_int16_t
 780 get_u16(const void *vp)
 781 {
 782         const u_char *p = (const u_char *)vp;
 783         u_int16_t v;
 784
 785         v  = (u_int16_t)p[0] << 8;
 786         v |= (u_int16_t)p[1];
 787
 788         return (v);
 789 }
 790
 791 void
 792 put_u64(void *vp, u_int64_t v)
 793 {
 794         u_char *p = (u_char *)vp;
 795
 796         p[0] = (u_char)(v >> 56) & 0xff;
 797         p[1] = (u_char)(v >> 48) & 0xff;
 798         p[2] = (u_char)(v >> 40) & 0xff;
 799         p[3] = (u_char)(v >> 32) & 0xff;
 800         p[4] = (u_char)(v >> 24) & 0xff;
 801         p[5] = (u_char)(v >> 16) & 0xff;
 802         p[6] = (u_char)(v >> 8) & 0xff;
 803         p[7] = (u_char)v & 0xff;
 804 }
 805
 806 void
 807 put_u32(void *vp, u_int32_t v)
 808 {
 809         u_char *p = (u_char *)vp;
 810
 811         p[0] = (u_char)(v >> 24) & 0xff;
 812         p[1] = (u_char)(v >> 16) & 0xff;
 813         p[2] = (u_char)(v >> 8) & 0xff;
 814         p[3] = (u_char)v & 0xff;
 815 }
 816
 817
 818 void
 819 put_u16(void *vp, u_int16_t v)
 820 {
 821         u_char *p = (u_char *)vp;
 822
 823         p[0] = (u_char)(v >> 8) & 0xff;
 824         p[1] = (u_char)v & 0xff;
 825 }