misc.c

   1 /* $OpenBSD: misc.c,v 1.84 2010/11/21 01:01:13 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/in_systm.h>
  42 #include <netinet/ip.h>
  43 #include <netinet/tcp.h>
  44
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <netdb.h>
  48 #ifdef HAVE_PATHS_H
  49 # include <paths.h>
  50 #include <pwd.h>
  51 #endif
  52 #ifdef SSH_TUN_OPENBSD
  53 #include <net/if.h>
  54 #endif
  55
  56 #include "xmalloc.h"
  57 #include "misc.h"
  58 #include "log.h"
  59 #include "ssh.h"
  60
  61 /* remove newline at end of string */
  62 char *
  63 chop(char *s)
  64 {
  65         char *t = s;
  66         while (*t) {
  67                 if (*t == '\n' || *t == '\r') {
  68                         *t = '\0';
  69                         return s;
  70                 }
  71                 t++;
  72         }
  73         return s;
  74
  75 }
  76
  77 /* set/unset filedescriptor to non-blocking */
  78 int
  79 set_nonblock(int fd)
  80 {
  81         int val;
  82
  83         val = fcntl(fd, F_GETFL, 0);
  84         if (val < 0) {
  85                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
  86                 return (-1);
  87         }
  88         if (val & O_NONBLOCK) {
  89                 debug3("fd %d is O_NONBLOCK", fd);
  90                 return (0);
  91         }
  92         debug2("fd %d setting O_NONBLOCK", fd);
  93         val |= O_NONBLOCK;
  94         if (fcntl(fd, F_SETFL, val) == -1) {
  95                 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
  96                     strerror(errno));
  97                 return (-1);
  98         }
  99         return (0);
 100 }
 101
 102 int
 103 unset_nonblock(int fd)
 104 {
 105         int val;
 106
 107         val = fcntl(fd, F_GETFL, 0);
 108         if (val < 0) {
 109                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
 110                 return (-1);
 111         }
 112         if (!(val & O_NONBLOCK)) {
 113                 debug3("fd %d is not O_NONBLOCK", fd);
 114                 return (0);
 115         }
 116         debug("fd %d clearing O_NONBLOCK", fd);
 117         val &= ~O_NONBLOCK;
 118         if (fcntl(fd, F_SETFL, val) == -1) {
 119                 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
 120                     fd, strerror(errno));
 121                 return (-1);
 122         }
 123         return (0);
 124 }
 125
 126 const char *
 127 ssh_gai_strerror(int gaierr)
 128 {
 129         if (gaierr == EAI_SYSTEM)
 130                 return strerror(errno);
 131         return gai_strerror(gaierr);
 132 }
 133
 134 /* disable nagle on socket */
 135 void
 136 set_nodelay(int fd)
 137 {
 138         int opt;
 139         socklen_t optlen;
 140
 141         optlen = sizeof opt;
 142         if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
 143                 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
 144                 return;
 145         }
 146         if (opt == 1) {
 147                 debug2("fd %d is TCP_NODELAY", fd);
 148                 return;
 149         }
 150         opt = 1;
 151         debug2("fd %d setting TCP_NODELAY", fd);
 152         if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
 153                 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
 154 }
 155
 156 /* Characters considered whitespace in strsep calls. */
 157 #define WHITESPACE " \t\r\n"
 158 #define QUOTE   "\""
 159
 160 /* return next token in configuration line */
 161 char *
 162 strdelim(char **s)
 163 {
 164         char *old;
 165         int wspace = 0;
 166
 167         if (*s == NULL)
 168                 return NULL;
 169
 170         old = *s;
 171
 172         *s = strpbrk(*s, WHITESPACE QUOTE "=");
 173         if (*s == NULL)
 174                 return (old);
 175
 176         if (*s[0] == '\"') {
 177                 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
 178                 /* Find matching quote */
 179                 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
 180                         return (NULL);          /* no matching quote */
 181                 } else {
 182                         *s[0] = '\0';
 183                         *s += strspn(*s + 1, WHITESPACE) + 1;
 184                         return (old);
 185                 }
 186         }
 187
 188         /* Allow only one '=' to be skipped */
 189         if (*s[0] == '=')
 190                 wspace = 1;
 191         *s[0] = '\0';
 192
 193         /* Skip any extra whitespace after first token */
 194         *s += strspn(*s + 1, WHITESPACE) + 1;
 195         if (*s[0] == '=' && !wspace)
 196                 *s += strspn(*s + 1, WHITESPACE) + 1;
 197
 198         return (old);
 199 }
 200
 201 struct passwd *
 202 pwcopy(struct passwd *pw)
 203 {
 204         struct passwd *copy = xcalloc(1, sizeof(*copy));
 205
 206         copy->pw_name = xstrdup(pw->pw_name);
 207         copy->pw_passwd = xstrdup(pw->pw_passwd);
 208         copy->pw_gecos = xstrdup(pw->pw_gecos);
 209         copy->pw_uid = pw->pw_uid;
 210         copy->pw_gid = pw->pw_gid;
 211 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
 212         copy->pw_expire = pw->pw_expire;
 213 #endif
 214 #ifdef HAVE_PW_CHANGE_IN_PASSWD
 215         copy->pw_change = pw->pw_change;
 216 #endif
 217 #ifdef HAVE_PW_CLASS_IN_PASSWD
 218         copy->pw_class = xstrdup(pw->pw_class);
 219 #endif
 220         copy->pw_dir = xstrdup(pw->pw_dir);
 221         copy->pw_shell = xstrdup(pw->pw_shell);
 222         return copy;
 223 }
 224
 225 /*
 226  * Convert ASCII string to TCP/IP port number.
 227  * Port must be >=0 and <=65535.
 228  * Return -1 if invalid.
 229  */
 230 int
 231 a2port(const char *s)
 232 {
 233         long long port;
 234         const char *errstr;
 235
 236         port = strtonum(s, 0, 65535, &errstr);
 237         if (errstr != NULL)
 238                 return -1;
 239         return (int)port;
 240 }
 241
 242 int
 243 a2tun(const char *s, int *remote)
 244 {
 245         const char *errstr = NULL;
 246         char *sp, *ep;
 247         int tun;
 248
 249         if (remote != NULL) {
 250                 *remote = SSH_TUNID_ANY;
 251                 sp = xstrdup(s);
 252                 if ((ep = strchr(sp, ':')) == NULL) {
 253                         xfree(sp);
 254                         return (a2tun(s, NULL));
 255                 }
 256                 ep[0] = '\0'; ep++;
 257                 *remote = a2tun(ep, NULL);
 258                 tun = a2tun(sp, NULL);
 259                 xfree(sp);
 260                 return (*remote == SSH_TUNID_ERR ? *remote : tun);
 261         }
 262
 263         if (strcasecmp(s, "any") == 0)
 264                 return (SSH_TUNID_ANY);
 265
 266         tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
 267         if (errstr != NULL)
 268                 return (SSH_TUNID_ERR);
 269
 270         return (tun);
 271 }
 272
 273 #define SECONDS         1
 274 #define MINUTES         (SECONDS * 60)
 275 #define HOURS           (MINUTES * 60)
 276 #define DAYS            (HOURS * 24)
 277 #define WEEKS           (DAYS * 7)
 278
 279 /*
 280  * Convert a time string into seconds; format is
 281  * a sequence of:
 282  *      time[qualifier]
 283  *
 284  * Valid time qualifiers are:
 285  *      <none>  seconds
 286  *      s|S     seconds
 287  *      m|M     minutes
 288  *      h|H     hours
 289  *      d|D     days
 290  *      w|W     weeks
 291  *
 292  * Examples:
 293  *      90m     90 minutes
 294  *      1h30m   90 minutes
 295  *      2d      2 days
 296  *      1w      1 week
 297  *
 298  * Return -1 if time string is invalid.
 299  */
 300 long
 301 convtime(const char *s)
 302 {
 303         long total, secs;
 304         const char *p;
 305         char *endp;
 306
 307         errno = 0;
 308         total = 0;
 309         p = s;
 310
 311         if (p == NULL || *p == '\0')
 312                 return -1;
 313
 314         while (*p) {
 315                 secs = strtol(p, &endp, 10);
 316                 if (p == endp ||
 317                     (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
 318                     secs < 0)
 319                         return -1;
 320
 321                 switch (*endp++) {
 322                 case '\0':
 323                         endp--;
 324                         break;
 325                 case 's':
 326                 case 'S':
 327                         break;
 328                 case 'm':
 329                 case 'M':
 330                         secs *= MINUTES;
 331                         break;
 332                 case 'h':
 333                 case 'H':
 334                         secs *= HOURS;
 335                         break;
 336                 case 'd':
 337                 case 'D':
 338                         secs *= DAYS;
 339                         break;
 340                 case 'w':
 341                 case 'W':
 342                         secs *= WEEKS;
 343                         break;
 344                 default:
 345                         return -1;
 346                 }
 347                 total += secs;
 348                 if (total < 0)
 349                         return -1;
 350                 p = endp;
 351         }
 352
 353         return total;
 354 }
 355
 356 /*
 357  * Returns a standardized host+port identifier string.
 358  * Caller must free returned string.
 359  */
 360 char *
 361 put_host_port(const char *host, u_short port)
 362 {
 363         char *hoststr;
 364
 365         if (port == 0 || port == SSH_DEFAULT_PORT)
 366                 return(xstrdup(host));
 367         if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
 368                 fatal("put_host_port: asprintf: %s", strerror(errno));
 369         debug3("put_host_port: %s", hoststr);
 370         return hoststr;
 371 }
 372
 373 /*
 374  * Search for next delimiter between hostnames/addresses and ports.
 375  * Argument may be modified (for termination).
 376  * Returns *cp if parsing succeeds.
 377  * *cp is set to the start of the next delimiter, if one was found.
 378  * If this is the last field, *cp is set to NULL.
 379  */
 380 char *
 381 hpdelim(char **cp)
 382 {
 383         char *s, *old;
 384
 385         if (cp == NULL || *cp == NULL)
 386                 return NULL;
 387
 388         old = s = *cp;
 389         if (*s == '[') {
 390                 if ((s = strchr(s, ']')) == NULL)
 391                         return NULL;
 392                 else
 393                         s++;
 394         } else if ((s = strpbrk(s, ":/")) == NULL)
 395                 s = *cp + strlen(*cp); /* skip to end (see first case below) */
 396
 397         switch (*s) {
 398         case '\0':
 399                 *cp = NULL;     /* no more fields*/
 400                 break;
 401
 402         case ':':
 403         case '/':
 404                 *s = '\0';      /* terminate */
 405                 *cp = s + 1;
 406                 break;
 407
 408         default:
 409                 return NULL;
 410         }
 411
 412         return old;
 413 }
 414
 415 char *
 416 cleanhostname(char *host)
 417 {
 418         if (*host == '[' && host[strlen(host) - 1] == ']') {
 419                 host[strlen(host) - 1] = '\0';
 420                 return (host + 1);
 421         } else
 422                 return host;
 423 }
 424
 425 char *
 426 colon(char *cp)
 427 {
 428         int flag = 0;
 429
 430         if (*cp == ':')         /* Leading colon is part of file name. */
 431                 return NULL;
 432         if (*cp == '[')
 433                 flag = 1;
 434
 435         for (; *cp; ++cp) {
 436                 if (*cp == '@' && *(cp+1) == '[')
 437                         flag = 1;
 438                 if (*cp == ']' && *(cp+1) == ':' && flag)
 439                         return (cp+1);
 440                 if (*cp == ':' && !flag)
 441                         return (cp);
 442                 if (*cp == '/')
 443                         return NULL;
 444         }
 445         return NULL;
 446 }
 447
 448 /* function to assist building execv() arguments */
 449 void
 450 addargs(arglist *args, char *fmt, ...)
 451 {
 452         va_list ap;
 453         char *cp;
 454         u_int nalloc;
 455         int r;
 456
 457         va_start(ap, fmt);
 458         r = vasprintf(&cp, fmt, ap);
 459         va_end(ap);
 460         if (r == -1)
 461                 fatal("addargs: argument too long");
 462
 463         nalloc = args->nalloc;
 464         if (args->list == NULL) {
 465                 nalloc = 32;
 466                 args->num = 0;
 467         } else if (args->num+2 >= nalloc)
 468                 nalloc *= 2;
 469
 470         args->list = xrealloc(args->list, nalloc, sizeof(char *));
 471         args->nalloc = nalloc;
 472         args->list[args->num++] = cp;
 473         args->list[args->num] = NULL;
 474 }
 475
 476 void
 477 replacearg(arglist *args, u_int which, char *fmt, ...)
 478 {
 479         va_list ap;
 480         char *cp;
 481         int r;
 482
 483         va_start(ap, fmt);
 484         r = vasprintf(&cp, fmt, ap);
 485         va_end(ap);
 486         if (r == -1)
 487                 fatal("replacearg: argument too long");
 488
 489         if (which >= args->num)
 490                 fatal("replacearg: tried to replace invalid arg %d >= %d",
 491                     which, args->num);
 492         xfree(args->list[which]);
 493         args->list[which] = cp;
 494 }
 495
 496 void
 497 freeargs(arglist *args)
 498 {
 499         u_int i;
 500
 501         if (args->list != NULL) {
 502                 for (i = 0; i < args->num; i++)
 503                         xfree(args->list[i]);
 504                 xfree(args->list);
 505                 args->nalloc = args->num = 0;
 506                 args->list = NULL;
 507         }
 508 }
 509
 510 /*
 511  * Expands tildes in the file name.  Returns data allocated by xmalloc.
 512  * Warning: this calls getpw*.
 513  */
 514 char *
 515 tilde_expand_filename(const char *filename, uid_t uid)
 516 {
 517         const char *path;
 518         char user[128], ret[MAXPATHLEN];
 519         struct passwd *pw;
 520         u_int len, slash;
 521
 522         if (*filename != '~')
 523                 return (xstrdup(filename));
 524         filename++;
 525
 526         path = strchr(filename, '/');
 527         if (path != NULL && path > filename) {          /* ~user/path */
 528                 slash = path - filename;
 529                 if (slash > sizeof(user) - 1)
 530                         fatal("tilde_expand_filename: ~username too long");
 531                 memcpy(user, filename, slash);
 532                 user[slash] = '\0';
 533                 if ((pw = getpwnam(user)) == NULL)
 534                         fatal("tilde_expand_filename: No such user %s", user);
 535         } else if ((pw = getpwuid(uid)) == NULL)        /* ~/path */
 536                 fatal("tilde_expand_filename: No such uid %ld", (long)uid);
 537
 538         if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
 539                 fatal("tilde_expand_filename: Path too long");
 540
 541         /* Make sure directory has a trailing '/' */
 542         len = strlen(pw->pw_dir);
 543         if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
 544             strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
 545                 fatal("tilde_expand_filename: Path too long");
 546
 547         /* Skip leading '/' from specified path */
 548         if (path != NULL)
 549                 filename = path + 1;
 550         if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
 551                 fatal("tilde_expand_filename: Path too long");
 552
 553         return (xstrdup(ret));
 554 }
 555
 556 /*
 557  * Expand a string with a set of %[char] escapes. A number of escapes may be
 558  * specified as (char *escape_chars, char *replacement) pairs. The list must
 559  * be terminated by a NULL escape_char. Returns replaced string in memory
 560  * allocated by xmalloc.
 561  */
 562 char *
 563 percent_expand(const char *string, ...)
 564 {
 565 #define EXPAND_MAX_KEYS 16
 566         u_int num_keys, i, j;
 567         struct {
 568                 const char *key;
 569                 const char *repl;
 570         } keys[EXPAND_MAX_KEYS];
 571         char buf[4096];
 572         va_list ap;
 573
 574         /* Gather keys */
 575         va_start(ap, string);
 576         for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
 577                 keys[num_keys].key = va_arg(ap, char *);
 578                 if (keys[num_keys].key == NULL)
 579                         break;
 580                 keys[num_keys].repl = va_arg(ap, char *);
 581                 if (keys[num_keys].repl == NULL)
 582                         fatal("%s: NULL replacement", __func__);
 583         }
 584         if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
 585                 fatal("%s: too many keys", __func__);
 586         va_end(ap);
 587
 588         /* Expand string */
 589         *buf = '\0';
 590         for (i = 0; *string != '\0'; string++) {
 591                 if (*string != '%') {
 592  append:
 593                         buf[i++] = *string;
 594                         if (i >= sizeof(buf))
 595                                 fatal("%s: string too long", __func__);
 596                         buf[i] = '\0';
 597                         continue;
 598                 }
 599                 string++;
 600                 /* %% case */
 601                 if (*string == '%')
 602                         goto append;
 603                 for (j = 0; j < num_keys; j++) {
 604                         if (strchr(keys[j].key, *string) != NULL) {
 605                                 i = strlcat(buf, keys[j].repl, sizeof(buf));
 606                                 if (i >= sizeof(buf))
 607                                         fatal("%s: string too long", __func__);
 608                                 break;
 609                         }
 610                 }
 611                 if (j >= num_keys)
 612                         fatal("%s: unknown key %%%c", __func__, *string);
 613         }
 614         return (xstrdup(buf));
 615 #undef EXPAND_MAX_KEYS
 616 }
 617
 618 /*
 619  * Read an entire line from a public key file into a static buffer, discarding
 620  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 621  */
 622 int
 623 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 624    u_long *lineno)
 625 {
 626         while (fgets(buf, bufsz, f) != NULL) {
 627                 if (buf[0] == '\0')
 628                         continue;
 629                 (*lineno)++;
 630                 if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
 631                         return 0;
 632                 } else {
 633                         debug("%s: %s line %lu exceeds size limit", __func__,
 634                             filename, *lineno);
 635                         /* discard remainder of line */
 636                         while (fgetc(f) != '\n' && !feof(f))
 637                                 ;       /* nothing */
 638                 }
 639         }
 640         return -1;
 641 }
 642
 643 int
 644 tun_open(int tun, int mode)
 645 {
 646 #if defined(CUSTOM_SYS_TUN_OPEN)
 647         return (sys_tun_open(tun, mode));
 648 #elif defined(SSH_TUN_OPENBSD)
 649         struct ifreq ifr;
 650         char name[100];
 651         int fd = -1, sock;
 652
 653         /* Open the tunnel device */
 654         if (tun <= SSH_TUNID_MAX) {
 655                 snprintf(name, sizeof(name), "/dev/tun%d", tun);
 656                 fd = open(name, O_RDWR);
 657         } else if (tun == SSH_TUNID_ANY) {
 658                 for (tun = 100; tun >= 0; tun--) {
 659                         snprintf(name, sizeof(name), "/dev/tun%d", tun);
 660                         if ((fd = open(name, O_RDWR)) >= 0)
 661                                 break;
 662                 }
 663         } else {
 664                 debug("%s: invalid tunnel %u", __func__, tun);
 665                 return (-1);
 666         }
 667
 668         if (fd < 0) {
 669                 debug("%s: %s open failed: %s", __func__, name, strerror(errno));
 670                 return (-1);
 671         }
 672
 673         debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 674
 675         /* Set the tunnel device operation mode */
 676         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
 677         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
 678                 goto failed;
 679
 680         if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
 681                 goto failed;
 682
 683         /* Set interface mode */
 684         ifr.ifr_flags &= ~IFF_UP;
 685         if (mode == SSH_TUNMODE_ETHERNET)
 686                 ifr.ifr_flags |= IFF_LINK0;
 687         else
 688                 ifr.ifr_flags &= ~IFF_LINK0;
 689         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 690                 goto failed;
 691
 692         /* Bring interface up */
 693         ifr.ifr_flags |= IFF_UP;
 694         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 695                 goto failed;
 696
 697         close(sock);
 698         return (fd);
 699
 700  failed:
 701         if (fd >= 0)
 702                 close(fd);
 703         if (sock >= 0)
 704                 close(sock);
 705         debug("%s: failed to set %s mode %d: %s", __func__, name,
 706             mode, strerror(errno));
 707         return (-1);
 708 #else
 709         error("Tunnel interfaces are not supported on this platform");
 710         return (-1);
 711 #endif
 712 }
 713
 714 void
 715 sanitise_stdfd(void)
 716 {
 717         int nullfd, dupfd;
 718
 719         if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
 720                 fprintf(stderr, "Couldn't open /dev/null: %s\n",
 721                     strerror(errno));
 722                 exit(1);
 723         }
 724         while (++dupfd <= 2) {
 725                 /* Only clobber closed fds */
 726                 if (fcntl(dupfd, F_GETFL, 0) >= 0)
 727                         continue;
 728                 if (dup2(nullfd, dupfd) == -1) {
 729                         fprintf(stderr, "dup2: %s\n", strerror(errno));
 730                         exit(1);
 731                 }
 732         }
 733         if (nullfd > 2)
 734                 close(nullfd);
 735 }
 736
 737 char *
 738 tohex(const void *vp, size_t l)
 739 {
 740         const u_char *p = (const u_char *)vp;
 741         char b[3], *r;
 742         size_t i, hl;
 743
 744         if (l > 65536)
 745                 return xstrdup("tohex: length > 65536");
 746
 747         hl = l * 2 + 1;
 748         r = xcalloc(1, hl);
 749         for (i = 0; i < l; i++) {
 750                 snprintf(b, sizeof(b), "%02x", p[i]);
 751                 strlcat(r, b, hl);
 752         }
 753         return (r);
 754 }
 755
 756 u_int64_t
 757 get_u64(const void *vp)
 758 {
 759         const u_char *p = (const u_char *)vp;
 760         u_int64_t v;
 761
 762         v  = (u_int64_t)p[0] << 56;
 763         v |= (u_int64_t)p[1] << 48;
 764         v |= (u_int64_t)p[2] << 40;
 765         v |= (u_int64_t)p[3] << 32;
 766         v |= (u_int64_t)p[4] << 24;
 767         v |= (u_int64_t)p[5] << 16;
 768         v |= (u_int64_t)p[6] << 8;
 769         v |= (u_int64_t)p[7];
 770
 771         return (v);
 772 }
 773
 774 u_int32_t
 775 get_u32(const void *vp)
 776 {
 777         const u_char *p = (const u_char *)vp;
 778         u_int32_t v;
 779
 780         v  = (u_int32_t)p[0] << 24;
 781         v |= (u_int32_t)p[1] << 16;
 782         v |= (u_int32_t)p[2] << 8;
 783         v |= (u_int32_t)p[3];
 784
 785         return (v);
 786 }
 787
 788 u_int16_t
 789 get_u16(const void *vp)
 790 {
 791         const u_char *p = (const u_char *)vp;
 792         u_int16_t v;
 793
 794         v  = (u_int16_t)p[0] << 8;
 795         v |= (u_int16_t)p[1];
 796
 797         return (v);
 798 }
 799
 800 void
 801 put_u64(void *vp, u_int64_t v)
 802 {
 803         u_char *p = (u_char *)vp;
 804
 805         p[0] = (u_char)(v >> 56) & 0xff;
 806         p[1] = (u_char)(v >> 48) & 0xff;
 807         p[2] = (u_char)(v >> 40) & 0xff;
 808         p[3] = (u_char)(v >> 32) & 0xff;
 809         p[4] = (u_char)(v >> 24) & 0xff;
 810         p[5] = (u_char)(v >> 16) & 0xff;
 811         p[6] = (u_char)(v >> 8) & 0xff;
 812         p[7] = (u_char)v & 0xff;
 813 }
 814
 815 void
 816 put_u32(void *vp, u_int32_t v)
 817 {
 818         u_char *p = (u_char *)vp;
 819
 820         p[0] = (u_char)(v >> 24) & 0xff;
 821         p[1] = (u_char)(v >> 16) & 0xff;
 822         p[2] = (u_char)(v >> 8) & 0xff;
 823         p[3] = (u_char)v & 0xff;
 824 }
 825
 826
 827 void
 828 put_u16(void *vp, u_int16_t v)
 829 {
 830         u_char *p = (u_char *)vp;
 831
 832         p[0] = (u_char)(v >> 8) & 0xff;
 833         p[1] = (u_char)v & 0xff;
 834 }
 835
 836 void
 837 ms_subtract_diff(struct timeval *start, int *ms)
 838 {
 839         struct timeval diff, finish;
 840
 841         gettimeofday(&finish, NULL);
 842         timersub(&finish, start, &diff);
 843         *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
 844 }
 845
 846 void
 847 ms_to_timeval(struct timeval *tv, int ms)
 848 {
 849         if (ms < 0)
 850                 ms = 0;
 851         tv->tv_sec = ms / 1000;
 852         tv->tv_usec = (ms % 1000) * 1000;
 853 }
 854
 855 void
 856 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
 857 {
 858         bw->buflen = buflen;
 859         bw->rate = kbps;
 860         bw->thresh = bw->rate;
 861         bw->lamt = 0;
 862         timerclear(&bw->bwstart);
 863         timerclear(&bw->bwend);
 864 }
 865
 866 /* Callback from read/write loop to insert bandwidth-limiting delays */
 867 void
 868 bandwidth_limit(struct bwlimit *bw, size_t read_len)
 869 {
 870         u_int64_t waitlen;
 871         struct timespec ts, rm;
 872
 873         if (!timerisset(&bw->bwstart)) {
 874                 gettimeofday(&bw->bwstart, NULL);
 875                 return;
 876         }
 877
 878         bw->lamt += read_len;
 879         if (bw->lamt < bw->thresh)
 880                 return;
 881
 882         gettimeofday(&bw->bwend, NULL);
 883         timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
 884         if (!timerisset(&bw->bwend))
 885                 return;
 886
 887         bw->lamt *= 8;
 888         waitlen = (double)1000000L * bw->lamt / bw->rate;
 889
 890         bw->bwstart.tv_sec = waitlen / 1000000L;
 891         bw->bwstart.tv_usec = waitlen % 1000000L;
 892
 893         if (timercmp(&bw->bwstart, &bw->bwend, >)) {
 894                 timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
 895
 896                 /* Adjust the wait time */
 897                 if (bw->bwend.tv_sec) {
 898                         bw->thresh /= 2;
 899                         if (bw->thresh < bw->buflen / 4)
 900                                 bw->thresh = bw->buflen / 4;
 901                 } else if (bw->bwend.tv_usec < 10000) {
 902                         bw->thresh *= 2;
 903                         if (bw->thresh > bw->buflen * 8)
 904                                 bw->thresh = bw->buflen * 8;
 905                 }
 906
 907                 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
 908                 while (nanosleep(&ts, &rm) == -1) {
 909                         if (errno != EINTR)
 910                                 break;
 911                         ts = rm;
 912                 }
 913         }
 914
 915         bw->lamt = 0;
 916         gettimeofday(&bw->bwstart, NULL);
 917 }
 918
 919 /* Make a template filename for mk[sd]temp() */
 920 void
 921 mktemp_proto(char *s, size_t len)
 922 {
 923         const char *tmpdir;
 924         int r;
 925
 926         if ((tmpdir = getenv("TMPDIR")) != NULL) {
 927                 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
 928                 if (r > 0 && (size_t)r < len)
 929                         return;
 930         }
 931         r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
 932         if (r < 0 || (size_t)r >= len)
 933                 fatal("%s: template string too short", __func__);
 934 }
 935
 936 static const struct {
 937         const char *name;
 938         int value;
 939 } ipqos[] = {
 940         { "af11", IPTOS_DSCP_AF11 },
 941         { "af12", IPTOS_DSCP_AF12 },
 942         { "af13", IPTOS_DSCP_AF13 },
 943         { "af14", IPTOS_DSCP_AF21 },
 944         { "af22", IPTOS_DSCP_AF22 },
 945         { "af23", IPTOS_DSCP_AF23 },
 946         { "af31", IPTOS_DSCP_AF31 },
 947         { "af32", IPTOS_DSCP_AF32 },
 948         { "af33", IPTOS_DSCP_AF33 },
 949         { "af41", IPTOS_DSCP_AF41 },
 950         { "af42", IPTOS_DSCP_AF42 },
 951         { "af43", IPTOS_DSCP_AF43 },
 952         { "cs0", IPTOS_DSCP_CS0 },
 953         { "cs1", IPTOS_DSCP_CS1 },
 954         { "cs2", IPTOS_DSCP_CS2 },
 955         { "cs3", IPTOS_DSCP_CS3 },
 956         { "cs4", IPTOS_DSCP_CS4 },
 957         { "cs5", IPTOS_DSCP_CS5 },
 958         { "cs6", IPTOS_DSCP_CS6 },
 959         { "cs7", IPTOS_DSCP_CS7 },
 960         { "ef", IPTOS_DSCP_EF },
 961         { "lowdelay", IPTOS_LOWDELAY },
 962         { "throughput", IPTOS_THROUGHPUT },
 963         { "reliability", IPTOS_RELIABILITY },
 964         { NULL, -1 }
 965 };
 966
 967 int
 968 parse_ipqos(const char *cp)
 969 {
 970         u_int i;
 971         char *ep;
 972         long val;
 973
 974         if (cp == NULL)
 975                 return -1;
 976         for (i = 0; ipqos[i].name != NULL; i++) {
 977                 if (strcasecmp(cp, ipqos[i].name) == 0)
 978                         return ipqos[i].value;
 979         }
 980         /* Try parsing as an integer */
 981         val = strtol(cp, &ep, 0);
 982         if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
 983                 return -1;
 984         return val;
 985 }
 986
 987 void
 988 sock_set_v6only(int s)
 989 {
 990 #ifdef IPV6_V6ONLY
 991         int on = 1;
 992
 993         debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
 994         if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
 995                 error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
 996 #endif
 997 }