crypto/openssh/misc.c

   1 /* $OpenBSD: misc.c,v 1.94 2014/07/15 15:54:14 millert 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/un.h>
  33 #include <sys/param.h>
  34
  35 #include <stdarg.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <time.h>
  40 #include <unistd.h>
  41
  42 #include <netinet/in.h>
  43 #include <netinet/in_systm.h>
  44 #include <netinet/ip.h>
  45 #include <netinet/tcp.h>
  46
  47 #include <ctype.h>
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <netdb.h>
  51 #ifdef HAVE_PATHS_H
  52 # include <paths.h>
  53 #include <pwd.h>
  54 #endif
  55 #ifdef SSH_TUN_OPENBSD
  56 #include <net/if.h>
  57 #endif
  58
  59 #include "xmalloc.h"
  60 #include "misc.h"
  61 #include "log.h"
  62 #include "ssh.h"
  63
  64 /* remove newline at end of string */
  65 char *
  66 chop(char *s)
  67 {
  68         char *t = s;
  69         while (*t) {
  70                 if (*t == '\n' || *t == '\r') {
  71                         *t = '\0';
  72                         return s;
  73                 }
  74                 t++;
  75         }
  76         return s;
  77
  78 }
  79
  80 /* set/unset filedescriptor to non-blocking */
  81 int
  82 set_nonblock(int fd)
  83 {
  84         int val;
  85
  86         val = fcntl(fd, F_GETFL, 0);
  87         if (val < 0) {
  88                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
  89                 return (-1);
  90         }
  91         if (val & O_NONBLOCK) {
  92                 debug3("fd %d is O_NONBLOCK", fd);
  93                 return (0);
  94         }
  95         debug2("fd %d setting O_NONBLOCK", fd);
  96         val |= O_NONBLOCK;
  97         if (fcntl(fd, F_SETFL, val) == -1) {
  98                 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
  99                     strerror(errno));
 100                 return (-1);
 101         }
 102         return (0);
 103 }
 104
 105 int
 106 unset_nonblock(int fd)
 107 {
 108         int val;
 109
 110         val = fcntl(fd, F_GETFL, 0);
 111         if (val < 0) {
 112                 error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
 113                 return (-1);
 114         }
 115         if (!(val & O_NONBLOCK)) {
 116                 debug3("fd %d is not O_NONBLOCK", fd);
 117                 return (0);
 118         }
 119         debug("fd %d clearing O_NONBLOCK", fd);
 120         val &= ~O_NONBLOCK;
 121         if (fcntl(fd, F_SETFL, val) == -1) {
 122                 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
 123                     fd, strerror(errno));
 124                 return (-1);
 125         }
 126         return (0);
 127 }
 128
 129 const char *
 130 ssh_gai_strerror(int gaierr)
 131 {
 132         if (gaierr == EAI_SYSTEM && errno != 0)
 133                 return strerror(errno);
 134         return gai_strerror(gaierr);
 135 }
 136
 137 /* disable nagle on socket */
 138 void
 139 set_nodelay(int fd)
 140 {
 141         int opt;
 142         socklen_t optlen;
 143
 144         optlen = sizeof opt;
 145         if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
 146                 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
 147                 return;
 148         }
 149         if (opt == 1) {
 150                 debug2("fd %d is TCP_NODELAY", fd);
 151                 return;
 152         }
 153         opt = 1;
 154         debug2("fd %d setting TCP_NODELAY", fd);
 155         if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
 156                 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
 157 }
 158
 159 /* Characters considered whitespace in strsep calls. */
 160 #define WHITESPACE " \t\r\n"
 161 #define QUOTE   "\""
 162
 163 /* return next token in configuration line */
 164 char *
 165 strdelim(char **s)
 166 {
 167         char *old;
 168         int wspace = 0;
 169
 170         if (*s == NULL)
 171                 return NULL;
 172
 173         old = *s;
 174
 175         *s = strpbrk(*s, WHITESPACE QUOTE "=");
 176         if (*s == NULL)
 177                 return (old);
 178
 179         if (*s[0] == '\"') {
 180                 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
 181                 /* Find matching quote */
 182                 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
 183                         return (NULL);          /* no matching quote */
 184                 } else {
 185                         *s[0] = '\0';
 186                         *s += strspn(*s + 1, WHITESPACE) + 1;
 187                         return (old);
 188                 }
 189         }
 190
 191         /* Allow only one '=' to be skipped */
 192         if (*s[0] == '=')
 193                 wspace = 1;
 194         *s[0] = '\0';
 195
 196         /* Skip any extra whitespace after first token */
 197         *s += strspn(*s + 1, WHITESPACE) + 1;
 198         if (*s[0] == '=' && !wspace)
 199                 *s += strspn(*s + 1, WHITESPACE) + 1;
 200
 201         return (old);
 202 }
 203
 204 struct passwd *
 205 pwcopy(struct passwd *pw)
 206 {
 207         struct passwd *copy = xcalloc(1, sizeof(*copy));
 208
 209         copy->pw_name = xstrdup(pw->pw_name);
 210         copy->pw_passwd = xstrdup(pw->pw_passwd);
 211 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
 212         copy->pw_gecos = xstrdup(pw->pw_gecos);
 213 #endif
 214         copy->pw_uid = pw->pw_uid;
 215         copy->pw_gid = pw->pw_gid;
 216 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
 217         copy->pw_expire = pw->pw_expire;
 218 #endif
 219 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
 220         copy->pw_change = pw->pw_change;
 221 #endif
 222 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
 223         copy->pw_class = xstrdup(pw->pw_class);
 224 #endif
 225         copy->pw_dir = xstrdup(pw->pw_dir);
 226         copy->pw_shell = xstrdup(pw->pw_shell);
 227         return copy;
 228 }
 229
 230 /*
 231  * Convert ASCII string to TCP/IP port number.
 232  * Port must be >=0 and <=65535.
 233  * Return -1 if invalid.
 234  */
 235 int
 236 a2port(const char *s)
 237 {
 238         long long port;
 239         const char *errstr;
 240
 241         port = strtonum(s, 0, 65535, &errstr);
 242         if (errstr != NULL)
 243                 return -1;
 244         return (int)port;
 245 }
 246
 247 int
 248 a2tun(const char *s, int *remote)
 249 {
 250         const char *errstr = NULL;
 251         char *sp, *ep;
 252         int tun;
 253
 254         if (remote != NULL) {
 255                 *remote = SSH_TUNID_ANY;
 256                 sp = xstrdup(s);
 257                 if ((ep = strchr(sp, ':')) == NULL) {
 258                         free(sp);
 259                         return (a2tun(s, NULL));
 260                 }
 261                 ep[0] = '\0'; ep++;
 262                 *remote = a2tun(ep, NULL);
 263                 tun = a2tun(sp, NULL);
 264                 free(sp);
 265                 return (*remote == SSH_TUNID_ERR ? *remote : tun);
 266         }
 267
 268         if (strcasecmp(s, "any") == 0)
 269                 return (SSH_TUNID_ANY);
 270
 271         tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
 272         if (errstr != NULL)
 273                 return (SSH_TUNID_ERR);
 274
 275         return (tun);
 276 }
 277
 278 #define SECONDS         1
 279 #define MINUTES         (SECONDS * 60)
 280 #define HOURS           (MINUTES * 60)
 281 #define DAYS            (HOURS * 24)
 282 #define WEEKS           (DAYS * 7)
 283
 284 /*
 285  * Convert a time string into seconds; format is
 286  * a sequence of:
 287  *      time[qualifier]
 288  *
 289  * Valid time qualifiers are:
 290  *      <none>  seconds
 291  *      s|S     seconds
 292  *      m|M     minutes
 293  *      h|H     hours
 294  *      d|D     days
 295  *      w|W     weeks
 296  *
 297  * Examples:
 298  *      90m     90 minutes
 299  *      1h30m   90 minutes
 300  *      2d      2 days
 301  *      1w      1 week
 302  *
 303  * Return -1 if time string is invalid.
 304  */
 305 long
 306 convtime(const char *s)
 307 {
 308         long total, secs;
 309         const char *p;
 310         char *endp;
 311
 312         errno = 0;
 313         total = 0;
 314         p = s;
 315
 316         if (p == NULL || *p == '\0')
 317                 return -1;
 318
 319         while (*p) {
 320                 secs = strtol(p, &endp, 10);
 321                 if (p == endp ||
 322                     (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
 323                     secs < 0)
 324                         return -1;
 325
 326                 switch (*endp++) {
 327                 case '\0':
 328                         endp--;
 329                         break;
 330                 case 's':
 331                 case 'S':
 332                         break;
 333                 case 'm':
 334                 case 'M':
 335                         secs *= MINUTES;
 336                         break;
 337                 case 'h':
 338                 case 'H':
 339                         secs *= HOURS;
 340                         break;
 341                 case 'd':
 342                 case 'D':
 343                         secs *= DAYS;
 344                         break;
 345                 case 'w':
 346                 case 'W':
 347                         secs *= WEEKS;
 348                         break;
 349                 default:
 350                         return -1;
 351                 }
 352                 total += secs;
 353                 if (total < 0)
 354                         return -1;
 355                 p = endp;
 356         }
 357
 358         return total;
 359 }
 360
 361 /*
 362  * Returns a standardized host+port identifier string.
 363  * Caller must free returned string.
 364  */
 365 char *
 366 put_host_port(const char *host, u_short port)
 367 {
 368         char *hoststr;
 369
 370         if (port == 0 || port == SSH_DEFAULT_PORT)
 371                 return(xstrdup(host));
 372         if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
 373                 fatal("put_host_port: asprintf: %s", strerror(errno));
 374         debug3("put_host_port: %s", hoststr);
 375         return hoststr;
 376 }
 377
 378 /*
 379  * Search for next delimiter between hostnames/addresses and ports.
 380  * Argument may be modified (for termination).
 381  * Returns *cp if parsing succeeds.
 382  * *cp is set to the start of the next delimiter, if one was found.
 383  * If this is the last field, *cp is set to NULL.
 384  */
 385 char *
 386 hpdelim(char **cp)
 387 {
 388         char *s, *old;
 389
 390         if (cp == NULL || *cp == NULL)
 391                 return NULL;
 392
 393         old = s = *cp;
 394         if (*s == '[') {
 395                 if ((s = strchr(s, ']')) == NULL)
 396                         return NULL;
 397                 else
 398                         s++;
 399         } else if ((s = strpbrk(s, ":/")) == NULL)
 400                 s = *cp + strlen(*cp); /* skip to end (see first case below) */
 401
 402         switch (*s) {
 403         case '\0':
 404                 *cp = NULL;     /* no more fields*/
 405                 break;
 406
 407         case ':':
 408         case '/':
 409                 *s = '\0';      /* terminate */
 410                 *cp = s + 1;
 411                 break;
 412
 413         default:
 414                 return NULL;
 415         }
 416
 417         return old;
 418 }
 419
 420 char *
 421 cleanhostname(char *host)
 422 {
 423         if (*host == '[' && host[strlen(host) - 1] == ']') {
 424                 host[strlen(host) - 1] = '\0';
 425                 return (host + 1);
 426         } else
 427                 return host;
 428 }
 429
 430 char *
 431 colon(char *cp)
 432 {
 433         int flag = 0;
 434
 435         if (*cp == ':')         /* Leading colon is part of file name. */
 436                 return NULL;
 437         if (*cp == '[')
 438                 flag = 1;
 439
 440         for (; *cp; ++cp) {
 441                 if (*cp == '@' && *(cp+1) == '[')
 442                         flag = 1;
 443                 if (*cp == ']' && *(cp+1) == ':' && flag)
 444                         return (cp+1);
 445                 if (*cp == ':' && !flag)
 446                         return (cp);
 447                 if (*cp == '/')
 448                         return NULL;
 449         }
 450         return NULL;
 451 }
 452
 453 /* function to assist building execv() arguments */
 454 void
 455 addargs(arglist *args, char *fmt, ...)
 456 {
 457         va_list ap;
 458         char *cp;
 459         u_int nalloc;
 460         int r;
 461
 462         va_start(ap, fmt);
 463         r = vasprintf(&cp, fmt, ap);
 464         va_end(ap);
 465         if (r == -1)
 466                 fatal("addargs: argument too long");
 467
 468         nalloc = args->nalloc;
 469         if (args->list == NULL) {
 470                 nalloc = 32;
 471                 args->num = 0;
 472         } else if (args->num+2 >= nalloc)
 473                 nalloc *= 2;
 474
 475         args->list = xrealloc(args->list, nalloc, sizeof(char *));
 476         args->nalloc = nalloc;
 477         args->list[args->num++] = cp;
 478         args->list[args->num] = NULL;
 479 }
 480
 481 void
 482 replacearg(arglist *args, u_int which, char *fmt, ...)
 483 {
 484         va_list ap;
 485         char *cp;
 486         int r;
 487
 488         va_start(ap, fmt);
 489         r = vasprintf(&cp, fmt, ap);
 490         va_end(ap);
 491         if (r == -1)
 492                 fatal("replacearg: argument too long");
 493
 494         if (which >= args->num)
 495                 fatal("replacearg: tried to replace invalid arg %d >= %d",
 496                     which, args->num);
 497         free(args->list[which]);
 498         args->list[which] = cp;
 499 }
 500
 501 void
 502 freeargs(arglist *args)
 503 {
 504         u_int i;
 505
 506         if (args->list != NULL) {
 507                 for (i = 0; i < args->num; i++)
 508                         free(args->list[i]);
 509                 free(args->list);
 510                 args->nalloc = args->num = 0;
 511                 args->list = NULL;
 512         }
 513 }
 514
 515 /*
 516  * Expands tildes in the file name.  Returns data allocated by xmalloc.
 517  * Warning: this calls getpw*.
 518  */
 519 char *
 520 tilde_expand_filename(const char *filename, uid_t uid)
 521 {
 522         const char *path, *sep;
 523         char user[128], *ret;
 524         struct passwd *pw;
 525         u_int len, slash;
 526
 527         if (*filename != '~')
 528                 return (xstrdup(filename));
 529         filename++;
 530
 531         path = strchr(filename, '/');
 532         if (path != NULL && path > filename) {          /* ~user/path */
 533                 slash = path - filename;
 534                 if (slash > sizeof(user) - 1)
 535                         fatal("tilde_expand_filename: ~username too long");
 536                 memcpy(user, filename, slash);
 537                 user[slash] = '\0';
 538                 if ((pw = getpwnam(user)) == NULL)
 539                         fatal("tilde_expand_filename: No such user %s", user);
 540         } else if ((pw = getpwuid(uid)) == NULL)        /* ~/path */
 541                 fatal("tilde_expand_filename: No such uid %ld", (long)uid);
 542
 543         /* Make sure directory has a trailing '/' */
 544         len = strlen(pw->pw_dir);
 545         if (len == 0 || pw->pw_dir[len - 1] != '/')
 546                 sep = "/";
 547         else
 548                 sep = "";
 549
 550         /* Skip leading '/' from specified path */
 551         if (path != NULL)
 552                 filename = path + 1;
 553
 554         if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= MAXPATHLEN)
 555                 fatal("tilde_expand_filename: Path too long");
 556
 557         return (ret);
 558 }
 559
 560 /*
 561  * Expand a string with a set of %[char] escapes. A number of escapes may be
 562  * specified as (char *escape_chars, char *replacement) pairs. The list must
 563  * be terminated by a NULL escape_char. Returns replaced string in memory
 564  * allocated by xmalloc.
 565  */
 566 char *
 567 percent_expand(const char *string, ...)
 568 {
 569 #define EXPAND_MAX_KEYS 16
 570         u_int num_keys, i, j;
 571         struct {
 572                 const char *key;
 573                 const char *repl;
 574         } keys[EXPAND_MAX_KEYS];
 575         char buf[4096];
 576         va_list ap;
 577
 578         /* Gather keys */
 579         va_start(ap, string);
 580         for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
 581                 keys[num_keys].key = va_arg(ap, char *);
 582                 if (keys[num_keys].key == NULL)
 583                         break;
 584                 keys[num_keys].repl = va_arg(ap, char *);
 585                 if (keys[num_keys].repl == NULL)
 586                         fatal("%s: NULL replacement", __func__);
 587         }
 588         if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
 589                 fatal("%s: too many keys", __func__);
 590         va_end(ap);
 591
 592         /* Expand string */
 593         *buf = '\0';
 594         for (i = 0; *string != '\0'; string++) {
 595                 if (*string != '%') {
 596  append:
 597                         buf[i++] = *string;
 598                         if (i >= sizeof(buf))
 599                                 fatal("%s: string too long", __func__);
 600                         buf[i] = '\0';
 601                         continue;
 602                 }
 603                 string++;
 604                 /* %% case */
 605                 if (*string == '%')
 606                         goto append;
 607                 for (j = 0; j < num_keys; j++) {
 608                         if (strchr(keys[j].key, *string) != NULL) {
 609                                 i = strlcat(buf, keys[j].repl, sizeof(buf));
 610                                 if (i >= sizeof(buf))
 611                                         fatal("%s: string too long", __func__);
 612                                 break;
 613                         }
 614                 }
 615                 if (j >= num_keys)
 616                         fatal("%s: unknown key %%%c", __func__, *string);
 617         }
 618         return (xstrdup(buf));
 619 #undef EXPAND_MAX_KEYS
 620 }
 621
 622 /*
 623  * Read an entire line from a public key file into a static buffer, discarding
 624  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 625  */
 626 int
 627 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 628    u_long *lineno)
 629 {
 630         while (fgets(buf, bufsz, f) != NULL) {
 631                 if (buf[0] == '\0')
 632                         continue;
 633                 (*lineno)++;
 634                 if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
 635                         return 0;
 636                 } else {
 637                         debug("%s: %s line %lu exceeds size limit", __func__,
 638                             filename, *lineno);
 639                         /* discard remainder of line */
 640                         while (fgetc(f) != '\n' && !feof(f))
 641                                 ;       /* nothing */
 642                 }
 643         }
 644         return -1;
 645 }
 646
 647 int
 648 tun_open(int tun, int mode)
 649 {
 650 #if defined(CUSTOM_SYS_TUN_OPEN)
 651         return (sys_tun_open(tun, mode));
 652 #elif defined(SSH_TUN_OPENBSD)
 653         struct ifreq ifr;
 654         char name[100];
 655         int fd = -1, sock;
 656
 657         /* Open the tunnel device */
 658         if (tun <= SSH_TUNID_MAX) {
 659                 snprintf(name, sizeof(name), "/dev/tun%d", tun);
 660                 fd = open(name, O_RDWR);
 661         } else if (tun == SSH_TUNID_ANY) {
 662                 for (tun = 100; tun >= 0; tun--) {
 663                         snprintf(name, sizeof(name), "/dev/tun%d", tun);
 664                         if ((fd = open(name, O_RDWR)) >= 0)
 665                                 break;
 666                 }
 667         } else {
 668                 debug("%s: invalid tunnel %u", __func__, tun);
 669                 return (-1);
 670         }
 671
 672         if (fd < 0) {
 673                 debug("%s: %s open failed: %s", __func__, name, strerror(errno));
 674                 return (-1);
 675         }
 676
 677         debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 678
 679         /* Set the tunnel device operation mode */
 680         snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
 681         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
 682                 goto failed;
 683
 684         if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
 685                 goto failed;
 686
 687         /* Set interface mode */
 688         ifr.ifr_flags &= ~IFF_UP;
 689         if (mode == SSH_TUNMODE_ETHERNET)
 690                 ifr.ifr_flags |= IFF_LINK0;
 691         else
 692                 ifr.ifr_flags &= ~IFF_LINK0;
 693         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 694                 goto failed;
 695
 696         /* Bring interface up */
 697         ifr.ifr_flags |= IFF_UP;
 698         if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
 699                 goto failed;
 700
 701         close(sock);
 702         return (fd);
 703
 704  failed:
 705         if (fd >= 0)
 706                 close(fd);
 707         if (sock >= 0)
 708                 close(sock);
 709         debug("%s: failed to set %s mode %d: %s", __func__, name,
 710             mode, strerror(errno));
 711         return (-1);
 712 #else
 713         error("Tunnel interfaces are not supported on this platform");
 714         return (-1);
 715 #endif
 716 }
 717
 718 void
 719 sanitise_stdfd(void)
 720 {
 721         int nullfd, dupfd;
 722
 723         if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
 724                 fprintf(stderr, "Couldn't open /dev/null: %s\n",
 725                     strerror(errno));
 726                 exit(1);
 727         }
 728         while (++dupfd <= 2) {
 729                 /* Only clobber closed fds */
 730                 if (fcntl(dupfd, F_GETFL, 0) >= 0)
 731                         continue;
 732                 if (dup2(nullfd, dupfd) == -1) {
 733                         fprintf(stderr, "dup2: %s\n", strerror(errno));
 734                         exit(1);
 735                 }
 736         }
 737         if (nullfd > 2)
 738                 close(nullfd);
 739 }
 740
 741 char *
 742 tohex(const void *vp, size_t l)
 743 {
 744         const u_char *p = (const u_char *)vp;
 745         char b[3], *r;
 746         size_t i, hl;
 747
 748         if (l > 65536)
 749                 return xstrdup("tohex: length > 65536");
 750
 751         hl = l * 2 + 1;
 752         r = xcalloc(1, hl);
 753         for (i = 0; i < l; i++) {
 754                 snprintf(b, sizeof(b), "%02x", p[i]);
 755                 strlcat(r, b, hl);
 756         }
 757         return (r);
 758 }
 759
 760 u_int64_t
 761 get_u64(const void *vp)
 762 {
 763         const u_char *p = (const u_char *)vp;
 764         u_int64_t v;
 765
 766         v  = (u_int64_t)p[0] << 56;
 767         v |= (u_int64_t)p[1] << 48;
 768         v |= (u_int64_t)p[2] << 40;
 769         v |= (u_int64_t)p[3] << 32;
 770         v |= (u_int64_t)p[4] << 24;
 771         v |= (u_int64_t)p[5] << 16;
 772         v |= (u_int64_t)p[6] << 8;
 773         v |= (u_int64_t)p[7];
 774
 775         return (v);
 776 }
 777
 778 u_int32_t
 779 get_u32(const void *vp)
 780 {
 781         const u_char *p = (const u_char *)vp;
 782         u_int32_t v;
 783
 784         v  = (u_int32_t)p[0] << 24;
 785         v |= (u_int32_t)p[1] << 16;
 786         v |= (u_int32_t)p[2] << 8;
 787         v |= (u_int32_t)p[3];
 788
 789         return (v);
 790 }
 791
 792 u_int32_t
 793 get_u32_le(const void *vp)
 794 {
 795         const u_char *p = (const u_char *)vp;
 796         u_int32_t v;
 797
 798         v  = (u_int32_t)p[0];
 799         v |= (u_int32_t)p[1] << 8;
 800         v |= (u_int32_t)p[2] << 16;
 801         v |= (u_int32_t)p[3] << 24;
 802
 803         return (v);
 804 }
 805
 806 u_int16_t
 807 get_u16(const void *vp)
 808 {
 809         const u_char *p = (const u_char *)vp;
 810         u_int16_t v;
 811
 812         v  = (u_int16_t)p[0] << 8;
 813         v |= (u_int16_t)p[1];
 814
 815         return (v);
 816 }
 817
 818 void
 819 put_u64(void *vp, u_int64_t v)
 820 {
 821         u_char *p = (u_char *)vp;
 822
 823         p[0] = (u_char)(v >> 56) & 0xff;
 824         p[1] = (u_char)(v >> 48) & 0xff;
 825         p[2] = (u_char)(v >> 40) & 0xff;
 826         p[3] = (u_char)(v >> 32) & 0xff;
 827         p[4] = (u_char)(v >> 24) & 0xff;
 828         p[5] = (u_char)(v >> 16) & 0xff;
 829         p[6] = (u_char)(v >> 8) & 0xff;
 830         p[7] = (u_char)v & 0xff;
 831 }
 832
 833 void
 834 put_u32(void *vp, u_int32_t v)
 835 {
 836         u_char *p = (u_char *)vp;
 837
 838         p[0] = (u_char)(v >> 24) & 0xff;
 839         p[1] = (u_char)(v >> 16) & 0xff;
 840         p[2] = (u_char)(v >> 8) & 0xff;
 841         p[3] = (u_char)v & 0xff;
 842 }
 843
 844 void
 845 put_u32_le(void *vp, u_int32_t v)
 846 {
 847         u_char *p = (u_char *)vp;
 848
 849         p[0] = (u_char)v & 0xff;
 850         p[1] = (u_char)(v >> 8) & 0xff;
 851         p[2] = (u_char)(v >> 16) & 0xff;
 852         p[3] = (u_char)(v >> 24) & 0xff;
 853 }
 854
 855 void
 856 put_u16(void *vp, u_int16_t v)
 857 {
 858         u_char *p = (u_char *)vp;
 859
 860         p[0] = (u_char)(v >> 8) & 0xff;
 861         p[1] = (u_char)v & 0xff;
 862 }
 863
 864 void
 865 ms_subtract_diff(struct timeval *start, int *ms)
 866 {
 867         struct timeval diff, finish;
 868
 869         gettimeofday(&finish, NULL);
 870         timersub(&finish, start, &diff);
 871         *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
 872 }
 873
 874 void
 875 ms_to_timeval(struct timeval *tv, int ms)
 876 {
 877         if (ms < 0)
 878                 ms = 0;
 879         tv->tv_sec = ms / 1000;
 880         tv->tv_usec = (ms % 1000) * 1000;
 881 }
 882
 883 time_t
 884 monotime(void)
 885 {
 886 #if defined(HAVE_CLOCK_GETTIME) && \
 887     (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
 888         struct timespec ts;
 889         static int gettime_failed = 0;
 890
 891         if (!gettime_failed) {
 892 #if defined(CLOCK_BOOTTIME)
 893                 if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
 894                         return (ts.tv_sec);
 895 #endif
 896 #if defined(CLOCK_MONOTONIC)
 897                 if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
 898                         return (ts.tv_sec);
 899 #endif
 900                 debug3("clock_gettime: %s", strerror(errno));
 901                 gettime_failed = 1;
 902         }
 903 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
 904
 905         return time(NULL);
 906 }
 907
 908 void
 909 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
 910 {
 911         bw->buflen = buflen;
 912         bw->rate = kbps;
 913         bw->thresh = bw->rate;
 914         bw->lamt = 0;
 915         timerclear(&bw->bwstart);
 916         timerclear(&bw->bwend);
 917 }
 918
 919 /* Callback from read/write loop to insert bandwidth-limiting delays */
 920 void
 921 bandwidth_limit(struct bwlimit *bw, size_t read_len)
 922 {
 923         u_int64_t waitlen;
 924         struct timespec ts, rm;
 925
 926         if (!timerisset(&bw->bwstart)) {
 927                 gettimeofday(&bw->bwstart, NULL);
 928                 return;
 929         }
 930
 931         bw->lamt += read_len;
 932         if (bw->lamt < bw->thresh)
 933                 return;
 934
 935         gettimeofday(&bw->bwend, NULL);
 936         timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
 937         if (!timerisset(&bw->bwend))
 938                 return;
 939
 940         bw->lamt *= 8;
 941         waitlen = (double)1000000L * bw->lamt / bw->rate;
 942
 943         bw->bwstart.tv_sec = waitlen / 1000000L;
 944         bw->bwstart.tv_usec = waitlen % 1000000L;
 945
 946         if (timercmp(&bw->bwstart, &bw->bwend, >)) {
 947                 timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
 948
 949                 /* Adjust the wait time */
 950                 if (bw->bwend.tv_sec) {
 951                         bw->thresh /= 2;
 952                         if (bw->thresh < bw->buflen / 4)
 953                                 bw->thresh = bw->buflen / 4;
 954                 } else if (bw->bwend.tv_usec < 10000) {
 955                         bw->thresh *= 2;
 956                         if (bw->thresh > bw->buflen * 8)
 957                                 bw->thresh = bw->buflen * 8;
 958                 }
 959
 960                 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
 961                 while (nanosleep(&ts, &rm) == -1) {
 962                         if (errno != EINTR)
 963                                 break;
 964                         ts = rm;
 965                 }
 966         }
 967
 968         bw->lamt = 0;
 969         gettimeofday(&bw->bwstart, NULL);
 970 }
 971
 972 /* Make a template filename for mk[sd]temp() */
 973 void
 974 mktemp_proto(char *s, size_t len)
 975 {
 976         const char *tmpdir;
 977         int r;
 978
 979         if ((tmpdir = getenv("TMPDIR")) != NULL) {
 980                 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
 981                 if (r > 0 && (size_t)r < len)
 982                         return;
 983         }
 984         r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
 985         if (r < 0 || (size_t)r >= len)
 986                 fatal("%s: template string too short", __func__);
 987 }
 988
 989 static const struct {
 990         const char *name;
 991         int value;
 992 } ipqos[] = {
 993         { "af11", IPTOS_DSCP_AF11 },
 994         { "af12", IPTOS_DSCP_AF12 },
 995         { "af13", IPTOS_DSCP_AF13 },
 996         { "af21", IPTOS_DSCP_AF21 },
 997         { "af22", IPTOS_DSCP_AF22 },
 998         { "af23", IPTOS_DSCP_AF23 },
 999         { "af31", IPTOS_DSCP_AF31 },
1000         { "af32", IPTOS_DSCP_AF32 },
1001         { "af33", IPTOS_DSCP_AF33 },
1002         { "af41", IPTOS_DSCP_AF41 },
1003         { "af42", IPTOS_DSCP_AF42 },
1004         { "af43", IPTOS_DSCP_AF43 },
1005         { "cs0", IPTOS_DSCP_CS0 },
1006         { "cs1", IPTOS_DSCP_CS1 },
1007         { "cs2", IPTOS_DSCP_CS2 },
1008         { "cs3", IPTOS_DSCP_CS3 },
1009         { "cs4", IPTOS_DSCP_CS4 },
1010         { "cs5", IPTOS_DSCP_CS5 },
1011         { "cs6", IPTOS_DSCP_CS6 },
1012         { "cs7", IPTOS_DSCP_CS7 },
1013         { "ef", IPTOS_DSCP_EF },
1014         { "lowdelay", IPTOS_LOWDELAY },
1015         { "throughput", IPTOS_THROUGHPUT },
1016         { "reliability", IPTOS_RELIABILITY },
1017         { NULL, -1 }
1018 };
1019
1020 int
1021 parse_ipqos(const char *cp)
1022 {
1023         u_int i;
1024         char *ep;
1025         long val;
1026
1027         if (cp == NULL)
1028                 return -1;
1029         for (i = 0; ipqos[i].name != NULL; i++) {
1030                 if (strcasecmp(cp, ipqos[i].name) == 0)
1031                         return ipqos[i].value;
1032         }
1033         /* Try parsing as an integer */
1034         val = strtol(cp, &ep, 0);
1035         if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1036                 return -1;
1037         return val;
1038 }
1039
1040 const char *
1041 iptos2str(int iptos)
1042 {
1043         int i;
1044         static char iptos_str[sizeof "0xff"];
1045
1046         for (i = 0; ipqos[i].name != NULL; i++) {
1047                 if (ipqos[i].value == iptos)
1048                         return ipqos[i].name;
1049         }
1050         snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1051         return iptos_str;
1052 }
1053
1054 void
1055 lowercase(char *s)
1056 {
1057         for (; *s; s++)
1058                 *s = tolower((u_char)*s);
1059 }
1060
1061 int
1062 unix_listener(const char *path, int backlog, int unlink_first)
1063 {
1064         struct sockaddr_un sunaddr;
1065         int saved_errno, sock;
1066
1067         memset(&sunaddr, 0, sizeof(sunaddr));
1068         sunaddr.sun_family = AF_UNIX;
1069         if (strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1070                 error("%s: \"%s\" too long for Unix domain socket", __func__,
1071                     path);
1072                 errno = ENAMETOOLONG;
1073                 return -1;
1074         }
1075
1076         sock = socket(PF_UNIX, SOCK_STREAM, 0);
1077         if (sock < 0) {
1078                 saved_errno = errno;
1079                 error("socket: %.100s", strerror(errno));
1080                 errno = saved_errno;
1081                 return -1;
1082         }
1083         if (unlink_first == 1) {
1084                 if (unlink(path) != 0 && errno != ENOENT)
1085                         error("unlink(%s): %.100s", path, strerror(errno));
1086         }
1087         if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
1088                 saved_errno = errno;
1089                 error("bind: %.100s", strerror(errno));
1090                 close(sock);
1091                 error("%s: cannot bind to path: %s", __func__, path);
1092                 errno = saved_errno;
1093                 return -1;
1094         }
1095         if (listen(sock, backlog) < 0) {
1096                 saved_errno = errno;
1097                 error("listen: %.100s", strerror(errno));
1098                 close(sock);
1099                 unlink(path);
1100                 error("%s: cannot listen on path: %s", __func__, path);
1101                 errno = saved_errno;
1102                 return -1;
1103         }
1104         return sock;
1105 }
1106
1107 void
1108 sock_set_v6only(int s)
1109 {
1110 #ifdef IPV6_V6ONLY
1111         int on = 1;
1112
1113         debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1114         if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1115                 error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1116 #endif
1117 }