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      1 /* $OpenBSD: misc.c,v 1.85 2011/03/29 18:54:17 stevesk 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 <time.h>
     39 #include <unistd.h>
     40 
     41 #include <netinet/in.h>
     42 #include <netinet/in_systm.h>
     43 #include <netinet/ip.h>
     44 #include <netinet/tcp.h>
     45 
     46 #include <errno.h>
     47 #include <fcntl.h>
     48 #include <netdb.h>
     49 #ifdef HAVE_PATHS_H
     50 # include <paths.h>
     51 #include <pwd.h>
     52 #endif
     53 #ifdef SSH_TUN_OPENBSD
     54 #include <net/if.h>
     55 #endif
     56 
     57 #include "xmalloc.h"
     58 #include "misc.h"
     59 #include "log.h"
     60 #include "ssh.h"
     61 
     62 /* remove newline at end of string */
     63 char *
     64 chop(char *s)
     65 {
     66 	char *t = s;
     67 	while (*t) {
     68 		if (*t == '\n' || *t == '\r') {
     69 			*t = '\0';
     70 			return s;
     71 		}
     72 		t++;
     73 	}
     74 	return s;
     75 
     76 }
     77 
     78 /* set/unset filedescriptor to non-blocking */
     79 int
     80 set_nonblock(int fd)
     81 {
     82 	int val;
     83 
     84 	val = fcntl(fd, F_GETFL, 0);
     85 	if (val < 0) {
     86 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
     87 		return (-1);
     88 	}
     89 	if (val & O_NONBLOCK) {
     90 		debug3("fd %d is O_NONBLOCK", fd);
     91 		return (0);
     92 	}
     93 	debug2("fd %d setting O_NONBLOCK", fd);
     94 	val |= O_NONBLOCK;
     95 	if (fcntl(fd, F_SETFL, val) == -1) {
     96 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
     97 		    strerror(errno));
     98 		return (-1);
     99 	}
    100 	return (0);
    101 }
    102 
    103 int
    104 unset_nonblock(int fd)
    105 {
    106 	int val;
    107 
    108 	val = fcntl(fd, F_GETFL, 0);
    109 	if (val < 0) {
    110 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
    111 		return (-1);
    112 	}
    113 	if (!(val & O_NONBLOCK)) {
    114 		debug3("fd %d is not O_NONBLOCK", fd);
    115 		return (0);
    116 	}
    117 	debug("fd %d clearing O_NONBLOCK", fd);
    118 	val &= ~O_NONBLOCK;
    119 	if (fcntl(fd, F_SETFL, val) == -1) {
    120 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
    121 		    fd, strerror(errno));
    122 		return (-1);
    123 	}
    124 	return (0);
    125 }
    126 
    127 const char *
    128 ssh_gai_strerror(int gaierr)
    129 {
    130 	if (gaierr == EAI_SYSTEM)
    131 		return strerror(errno);
    132 	return gai_strerror(gaierr);
    133 }
    134 
    135 /* disable nagle on socket */
    136 void
    137 set_nodelay(int fd)
    138 {
    139 	int opt;
    140 	socklen_t optlen;
    141 
    142 	optlen = sizeof opt;
    143 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
    144 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
    145 		return;
    146 	}
    147 	if (opt == 1) {
    148 		debug2("fd %d is TCP_NODELAY", fd);
    149 		return;
    150 	}
    151 	opt = 1;
    152 	debug2("fd %d setting TCP_NODELAY", fd);
    153 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
    154 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
    155 }
    156 
    157 /* Characters considered whitespace in strsep calls. */
    158 #define WHITESPACE " \t\r\n"
    159 #define QUOTE	"\""
    160 
    161 /* return next token in configuration line */
    162 char *
    163 strdelim(char **s)
    164 {
    165 	char *old;
    166 	int wspace = 0;
    167 
    168 	if (*s == NULL)
    169 		return NULL;
    170 
    171 	old = *s;
    172 
    173 	*s = strpbrk(*s, WHITESPACE QUOTE "=");
    174 	if (*s == NULL)
    175 		return (old);
    176 
    177 	if (*s[0] == '\"') {
    178 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
    179 		/* Find matching quote */
    180 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
    181 			return (NULL);		/* no matching quote */
    182 		} else {
    183 			*s[0] = '\0';
    184 			*s += strspn(*s + 1, WHITESPACE) + 1;
    185 			return (old);
    186 		}
    187 	}
    188 
    189 	/* Allow only one '=' to be skipped */
    190 	if (*s[0] == '=')
    191 		wspace = 1;
    192 	*s[0] = '\0';
    193 
    194 	/* Skip any extra whitespace after first token */
    195 	*s += strspn(*s + 1, WHITESPACE) + 1;
    196 	if (*s[0] == '=' && !wspace)
    197 		*s += strspn(*s + 1, WHITESPACE) + 1;
    198 
    199 	return (old);
    200 }
    201 
    202 struct passwd *
    203 pwcopy(struct passwd *pw)
    204 {
    205 	struct passwd *copy = xcalloc(1, sizeof(*copy));
    206 
    207 	copy->pw_name = xstrdup(pw->pw_name);
    208 	copy->pw_passwd = pw->pw_passwd ? xstrdup(pw->pw_passwd) : NULL;
    209 #ifdef HAVE_PW_GECOS_IN_PASSWD
    210 	copy->pw_gecos = xstrdup(pw->pw_gecos);
    211 #endif
    212 	copy->pw_uid = pw->pw_uid;
    213 	copy->pw_gid = pw->pw_gid;
    214 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
    215 	copy->pw_expire = pw->pw_expire;
    216 #endif
    217 #ifdef HAVE_PW_CHANGE_IN_PASSWD
    218 	copy->pw_change = pw->pw_change;
    219 #endif
    220 #ifdef HAVE_PW_CLASS_IN_PASSWD
    221 	copy->pw_class = xstrdup(pw->pw_class);
    222 #endif
    223 	copy->pw_dir = xstrdup(pw->pw_dir);
    224 	copy->pw_shell = xstrdup(pw->pw_shell);
    225 	return copy;
    226 }
    227 
    228 /*
    229  * Convert ASCII string to TCP/IP port number.
    230  * Port must be >=0 and <=65535.
    231  * Return -1 if invalid.
    232  */
    233 int
    234 a2port(const char *s)
    235 {
    236 	long long port;
    237 	const char *errstr;
    238 
    239 	port = strtonum(s, 0, 65535, &errstr);
    240 	if (errstr != NULL)
    241 		return -1;
    242 	return (int)port;
    243 }
    244 
    245 int
    246 a2tun(const char *s, int *remote)
    247 {
    248 	const char *errstr = NULL;
    249 	char *sp, *ep;
    250 	int tun;
    251 
    252 	if (remote != NULL) {
    253 		*remote = SSH_TUNID_ANY;
    254 		sp = xstrdup(s);
    255 		if ((ep = strchr(sp, ':')) == NULL) {
    256 			xfree(sp);
    257 			return (a2tun(s, NULL));
    258 		}
    259 		ep[0] = '\0'; ep++;
    260 		*remote = a2tun(ep, NULL);
    261 		tun = a2tun(sp, NULL);
    262 		xfree(sp);
    263 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
    264 	}
    265 
    266 	if (strcasecmp(s, "any") == 0)
    267 		return (SSH_TUNID_ANY);
    268 
    269 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
    270 	if (errstr != NULL)
    271 		return (SSH_TUNID_ERR);
    272 
    273 	return (tun);
    274 }
    275 
    276 #define SECONDS		1
    277 #define MINUTES		(SECONDS * 60)
    278 #define HOURS		(MINUTES * 60)
    279 #define DAYS		(HOURS * 24)
    280 #define WEEKS		(DAYS * 7)
    281 
    282 /*
    283  * Convert a time string into seconds; format is
    284  * a sequence of:
    285  *      time[qualifier]
    286  *
    287  * Valid time qualifiers are:
    288  *      <none>  seconds
    289  *      s|S     seconds
    290  *      m|M     minutes
    291  *      h|H     hours
    292  *      d|D     days
    293  *      w|W     weeks
    294  *
    295  * Examples:
    296  *      90m     90 minutes
    297  *      1h30m   90 minutes
    298  *      2d      2 days
    299  *      1w      1 week
    300  *
    301  * Return -1 if time string is invalid.
    302  */
    303 long
    304 convtime(const char *s)
    305 {
    306 	long total, secs;
    307 	const char *p;
    308 	char *endp;
    309 
    310 	errno = 0;
    311 	total = 0;
    312 	p = s;
    313 
    314 	if (p == NULL || *p == '\0')
    315 		return -1;
    316 
    317 	while (*p) {
    318 		secs = strtol(p, &endp, 10);
    319 		if (p == endp ||
    320 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
    321 		    secs < 0)
    322 			return -1;
    323 
    324 		switch (*endp++) {
    325 		case '\0':
    326 			endp--;
    327 			break;
    328 		case 's':
    329 		case 'S':
    330 			break;
    331 		case 'm':
    332 		case 'M':
    333 			secs *= MINUTES;
    334 			break;
    335 		case 'h':
    336 		case 'H':
    337 			secs *= HOURS;
    338 			break;
    339 		case 'd':
    340 		case 'D':
    341 			secs *= DAYS;
    342 			break;
    343 		case 'w':
    344 		case 'W':
    345 			secs *= WEEKS;
    346 			break;
    347 		default:
    348 			return -1;
    349 		}
    350 		total += secs;
    351 		if (total < 0)
    352 			return -1;
    353 		p = endp;
    354 	}
    355 
    356 	return total;
    357 }
    358 
    359 /*
    360  * Returns a standardized host+port identifier string.
    361  * Caller must free returned string.
    362  */
    363 char *
    364 put_host_port(const char *host, u_short port)
    365 {
    366 	char *hoststr;
    367 
    368 	if (port == 0 || port == SSH_DEFAULT_PORT)
    369 		return(xstrdup(host));
    370 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
    371 		fatal("put_host_port: asprintf: %s", strerror(errno));
    372 	debug3("put_host_port: %s", hoststr);
    373 	return hoststr;
    374 }
    375 
    376 /*
    377  * Search for next delimiter between hostnames/addresses and ports.
    378  * Argument may be modified (for termination).
    379  * Returns *cp if parsing succeeds.
    380  * *cp is set to the start of the next delimiter, if one was found.
    381  * If this is the last field, *cp is set to NULL.
    382  */
    383 char *
    384 hpdelim(char **cp)
    385 {
    386 	char *s, *old;
    387 
    388 	if (cp == NULL || *cp == NULL)
    389 		return NULL;
    390 
    391 	old = s = *cp;
    392 	if (*s == '[') {
    393 		if ((s = strchr(s, ']')) == NULL)
    394 			return NULL;
    395 		else
    396 			s++;
    397 	} else if ((s = strpbrk(s, ":/")) == NULL)
    398 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
    399 
    400 	switch (*s) {
    401 	case '\0':
    402 		*cp = NULL;	/* no more fields*/
    403 		break;
    404 
    405 	case ':':
    406 	case '/':
    407 		*s = '\0';	/* terminate */
    408 		*cp = s + 1;
    409 		break;
    410 
    411 	default:
    412 		return NULL;
    413 	}
    414 
    415 	return old;
    416 }
    417 
    418 char *
    419 cleanhostname(char *host)
    420 {
    421 	if (*host == '[' && host[strlen(host) - 1] == ']') {
    422 		host[strlen(host) - 1] = '\0';
    423 		return (host + 1);
    424 	} else
    425 		return host;
    426 }
    427 
    428 char *
    429 colon(char *cp)
    430 {
    431 	int flag = 0;
    432 
    433 	if (*cp == ':')		/* Leading colon is part of file name. */
    434 		return NULL;
    435 	if (*cp == '[')
    436 		flag = 1;
    437 
    438 	for (; *cp; ++cp) {
    439 		if (*cp == '@' && *(cp+1) == '[')
    440 			flag = 1;
    441 		if (*cp == ']' && *(cp+1) == ':' && flag)
    442 			return (cp+1);
    443 		if (*cp == ':' && !flag)
    444 			return (cp);
    445 		if (*cp == '/')
    446 			return NULL;
    447 	}
    448 	return NULL;
    449 }
    450 
    451 /* function to assist building execv() arguments */
    452 void
    453 addargs(arglist *args, char *fmt, ...)
    454 {
    455 	va_list ap;
    456 	char *cp;
    457 	u_int nalloc;
    458 	int r;
    459 
    460 	va_start(ap, fmt);
    461 	r = vasprintf(&cp, fmt, ap);
    462 	va_end(ap);
    463 	if (r == -1)
    464 		fatal("addargs: argument too long");
    465 
    466 	nalloc = args->nalloc;
    467 	if (args->list == NULL) {
    468 		nalloc = 32;
    469 		args->num = 0;
    470 	} else if (args->num+2 >= nalloc)
    471 		nalloc *= 2;
    472 
    473 	args->list = xrealloc(args->list, nalloc, sizeof(char *));
    474 	args->nalloc = nalloc;
    475 	args->list[args->num++] = cp;
    476 	args->list[args->num] = NULL;
    477 }
    478 
    479 void
    480 replacearg(arglist *args, u_int which, char *fmt, ...)
    481 {
    482 	va_list ap;
    483 	char *cp;
    484 	int r;
    485 
    486 	va_start(ap, fmt);
    487 	r = vasprintf(&cp, fmt, ap);
    488 	va_end(ap);
    489 	if (r == -1)
    490 		fatal("replacearg: argument too long");
    491 
    492 	if (which >= args->num)
    493 		fatal("replacearg: tried to replace invalid arg %d >= %d",
    494 		    which, args->num);
    495 	xfree(args->list[which]);
    496 	args->list[which] = cp;
    497 }
    498 
    499 void
    500 freeargs(arglist *args)
    501 {
    502 	u_int i;
    503 
    504 	if (args->list != NULL) {
    505 		for (i = 0; i < args->num; i++)
    506 			xfree(args->list[i]);
    507 		xfree(args->list);
    508 		args->nalloc = args->num = 0;
    509 		args->list = NULL;
    510 	}
    511 }
    512 
    513 /*
    514  * Expands tildes in the file name.  Returns data allocated by xmalloc.
    515  * Warning: this calls getpw*.
    516  */
    517 char *
    518 tilde_expand_filename(const char *filename, uid_t uid)
    519 {
    520 	const char *path;
    521 	char user[128], ret[MAXPATHLEN];
    522 	struct passwd *pw;
    523 	u_int len, slash;
    524 
    525 	if (*filename != '~')
    526 		return (xstrdup(filename));
    527 	filename++;
    528 
    529 	path = strchr(filename, '/');
    530 	if (path != NULL && path > filename) {		/* ~user/path */
    531 		slash = path - filename;
    532 		if (slash > sizeof(user) - 1)
    533 			fatal("tilde_expand_filename: ~username too long");
    534 		memcpy(user, filename, slash);
    535 		user[slash] = '\0';
    536 		if ((pw = getpwnam(user)) == NULL)
    537 			fatal("tilde_expand_filename: No such user %s", user);
    538 	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
    539 		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
    540 
    541 	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
    542 		fatal("tilde_expand_filename: Path too long");
    543 
    544 	/* Make sure directory has a trailing '/' */
    545 	len = strlen(pw->pw_dir);
    546 	if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
    547 	    strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
    548 		fatal("tilde_expand_filename: Path too long");
    549 
    550 	/* Skip leading '/' from specified path */
    551 	if (path != NULL)
    552 		filename = path + 1;
    553 	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
    554 		fatal("tilde_expand_filename: Path too long");
    555 
    556 	return (xstrdup(ret));
    557 }
    558 
    559 /*
    560  * Expand a string with a set of %[char] escapes. A number of escapes may be
    561  * specified as (char *escape_chars, char *replacement) pairs. The list must
    562  * be terminated by a NULL escape_char. Returns replaced string in memory
    563  * allocated by xmalloc.
    564  */
    565 char *
    566 percent_expand(const char *string, ...)
    567 {
    568 #define EXPAND_MAX_KEYS	16
    569 	u_int num_keys, i, j;
    570 	struct {
    571 		const char *key;
    572 		const char *repl;
    573 	} keys[EXPAND_MAX_KEYS];
    574 	char buf[4096];
    575 	va_list ap;
    576 
    577 	/* Gather keys */
    578 	va_start(ap, string);
    579 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
    580 		keys[num_keys].key = va_arg(ap, char *);
    581 		if (keys[num_keys].key == NULL)
    582 			break;
    583 		keys[num_keys].repl = va_arg(ap, char *);
    584 		if (keys[num_keys].repl == NULL)
    585 			fatal("%s: NULL replacement", __func__);
    586 	}
    587 	if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
    588 		fatal("%s: too many keys", __func__);
    589 	va_end(ap);
    590 
    591 	/* Expand string */
    592 	*buf = '\0';
    593 	for (i = 0; *string != '\0'; string++) {
    594 		if (*string != '%') {
    595  append:
    596 			buf[i++] = *string;
    597 			if (i >= sizeof(buf))
    598 				fatal("%s: string too long", __func__);
    599 			buf[i] = '\0';
    600 			continue;
    601 		}
    602 		string++;
    603 		/* %% case */
    604 		if (*string == '%')
    605 			goto append;
    606 		for (j = 0; j < num_keys; j++) {
    607 			if (strchr(keys[j].key, *string) != NULL) {
    608 				i = strlcat(buf, keys[j].repl, sizeof(buf));
    609 				if (i >= sizeof(buf))
    610 					fatal("%s: string too long", __func__);
    611 				break;
    612 			}
    613 		}
    614 		if (j >= num_keys)
    615 			fatal("%s: unknown key %%%c", __func__, *string);
    616 	}
    617 	return (xstrdup(buf));
    618 #undef EXPAND_MAX_KEYS
    619 }
    620 
    621 /*
    622  * Read an entire line from a public key file into a static buffer, discarding
    623  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
    624  */
    625 int
    626 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
    627    u_long *lineno)
    628 {
    629 	while (fgets(buf, bufsz, f) != NULL) {
    630 		if (buf[0] == '\0')
    631 			continue;
    632 		(*lineno)++;
    633 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
    634 			return 0;
    635 		} else {
    636 			debug("%s: %s line %lu exceeds size limit", __func__,
    637 			    filename, *lineno);
    638 			/* discard remainder of line */
    639 			while (fgetc(f) != '\n' && !feof(f))
    640 				;	/* nothing */
    641 		}
    642 	}
    643 	return -1;
    644 }
    645 
    646 int
    647 tun_open(int tun, int mode)
    648 {
    649 #if defined(CUSTOM_SYS_TUN_OPEN)
    650 	return (sys_tun_open(tun, mode));
    651 #elif defined(SSH_TUN_OPENBSD)
    652 	struct ifreq ifr;
    653 	char name[100];
    654 	int fd = -1, sock;
    655 
    656 	/* Open the tunnel device */
    657 	if (tun <= SSH_TUNID_MAX) {
    658 		snprintf(name, sizeof(name), "/dev/tun%d", tun);
    659 		fd = open(name, O_RDWR);
    660 	} else if (tun == SSH_TUNID_ANY) {
    661 		for (tun = 100; tun >= 0; tun--) {
    662 			snprintf(name, sizeof(name), "/dev/tun%d", tun);
    663 			if ((fd = open(name, O_RDWR)) >= 0)
    664 				break;
    665 		}
    666 	} else {
    667 		debug("%s: invalid tunnel %u", __func__, tun);
    668 		return (-1);
    669 	}
    670 
    671 	if (fd < 0) {
    672 		debug("%s: %s open failed: %s", __func__, name, strerror(errno));
    673 		return (-1);
    674 	}
    675 
    676 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
    677 
    678 	/* Set the tunnel device operation mode */
    679 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
    680 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
    681 		goto failed;
    682 
    683 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
    684 		goto failed;
    685 
    686 	/* Set interface mode */
    687 	ifr.ifr_flags &= ~IFF_UP;
    688 	if (mode == SSH_TUNMODE_ETHERNET)
    689 		ifr.ifr_flags |= IFF_LINK0;
    690 	else
    691 		ifr.ifr_flags &= ~IFF_LINK0;
    692 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
    693 		goto failed;
    694 
    695 	/* Bring interface up */
    696 	ifr.ifr_flags |= IFF_UP;
    697 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
    698 		goto failed;
    699 
    700 	close(sock);
    701 	return (fd);
    702 
    703  failed:
    704 	if (fd >= 0)
    705 		close(fd);
    706 	if (sock >= 0)
    707 		close(sock);
    708 	debug("%s: failed to set %s mode %d: %s", __func__, name,
    709 	    mode, strerror(errno));
    710 	return (-1);
    711 #else
    712 	error("Tunnel interfaces are not supported on this platform");
    713 	return (-1);
    714 #endif
    715 }
    716 
    717 void
    718 sanitise_stdfd(void)
    719 {
    720 	int nullfd, dupfd;
    721 
    722 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
    723 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
    724 		    strerror(errno));
    725 		exit(1);
    726 	}
    727 	while (++dupfd <= 2) {
    728 		/* Only clobber closed fds */
    729 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
    730 			continue;
    731 		if (dup2(nullfd, dupfd) == -1) {
    732 			fprintf(stderr, "dup2: %s\n", strerror(errno));
    733 			exit(1);
    734 		}
    735 	}
    736 	if (nullfd > 2)
    737 		close(nullfd);
    738 }
    739 
    740 char *
    741 tohex(const void *vp, size_t l)
    742 {
    743 	const u_char *p = (const u_char *)vp;
    744 	char b[3], *r;
    745 	size_t i, hl;
    746 
    747 	if (l > 65536)
    748 		return xstrdup("tohex: length > 65536");
    749 
    750 	hl = l * 2 + 1;
    751 	r = xcalloc(1, hl);
    752 	for (i = 0; i < l; i++) {
    753 		snprintf(b, sizeof(b), "%02x", p[i]);
    754 		strlcat(r, b, hl);
    755 	}
    756 	return (r);
    757 }
    758 
    759 u_int64_t
    760 get_u64(const void *vp)
    761 {
    762 	const u_char *p = (const u_char *)vp;
    763 	u_int64_t v;
    764 
    765 	v  = (u_int64_t)p[0] << 56;
    766 	v |= (u_int64_t)p[1] << 48;
    767 	v |= (u_int64_t)p[2] << 40;
    768 	v |= (u_int64_t)p[3] << 32;
    769 	v |= (u_int64_t)p[4] << 24;
    770 	v |= (u_int64_t)p[5] << 16;
    771 	v |= (u_int64_t)p[6] << 8;
    772 	v |= (u_int64_t)p[7];
    773 
    774 	return (v);
    775 }
    776 
    777 u_int32_t
    778 get_u32(const void *vp)
    779 {
    780 	const u_char *p = (const u_char *)vp;
    781 	u_int32_t v;
    782 
    783 	v  = (u_int32_t)p[0] << 24;
    784 	v |= (u_int32_t)p[1] << 16;
    785 	v |= (u_int32_t)p[2] << 8;
    786 	v |= (u_int32_t)p[3];
    787 
    788 	return (v);
    789 }
    790 
    791 u_int16_t
    792 get_u16(const void *vp)
    793 {
    794 	const u_char *p = (const u_char *)vp;
    795 	u_int16_t v;
    796 
    797 	v  = (u_int16_t)p[0] << 8;
    798 	v |= (u_int16_t)p[1];
    799 
    800 	return (v);
    801 }
    802 
    803 void
    804 put_u64(void *vp, u_int64_t v)
    805 {
    806 	u_char *p = (u_char *)vp;
    807 
    808 	p[0] = (u_char)(v >> 56) & 0xff;
    809 	p[1] = (u_char)(v >> 48) & 0xff;
    810 	p[2] = (u_char)(v >> 40) & 0xff;
    811 	p[3] = (u_char)(v >> 32) & 0xff;
    812 	p[4] = (u_char)(v >> 24) & 0xff;
    813 	p[5] = (u_char)(v >> 16) & 0xff;
    814 	p[6] = (u_char)(v >> 8) & 0xff;
    815 	p[7] = (u_char)v & 0xff;
    816 }
    817 
    818 void
    819 put_u32(void *vp, u_int32_t v)
    820 {
    821 	u_char *p = (u_char *)vp;
    822 
    823 	p[0] = (u_char)(v >> 24) & 0xff;
    824 	p[1] = (u_char)(v >> 16) & 0xff;
    825 	p[2] = (u_char)(v >> 8) & 0xff;
    826 	p[3] = (u_char)v & 0xff;
    827 }
    828 
    829 
    830 void
    831 put_u16(void *vp, u_int16_t v)
    832 {
    833 	u_char *p = (u_char *)vp;
    834 
    835 	p[0] = (u_char)(v >> 8) & 0xff;
    836 	p[1] = (u_char)v & 0xff;
    837 }
    838 
    839 void
    840 ms_subtract_diff(struct timeval *start, int *ms)
    841 {
    842 	struct timeval diff, finish;
    843 
    844 	gettimeofday(&finish, NULL);
    845 	timersub(&finish, start, &diff);
    846 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
    847 }
    848 
    849 void
    850 ms_to_timeval(struct timeval *tv, int ms)
    851 {
    852 	if (ms < 0)
    853 		ms = 0;
    854 	tv->tv_sec = ms / 1000;
    855 	tv->tv_usec = (ms % 1000) * 1000;
    856 }
    857 
    858 void
    859 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
    860 {
    861 	bw->buflen = buflen;
    862 	bw->rate = kbps;
    863 	bw->thresh = bw->rate;
    864 	bw->lamt = 0;
    865 	timerclear(&bw->bwstart);
    866 	timerclear(&bw->bwend);
    867 }
    868 
    869 /* Callback from read/write loop to insert bandwidth-limiting delays */
    870 void
    871 bandwidth_limit(struct bwlimit *bw, size_t read_len)
    872 {
    873 	u_int64_t waitlen;
    874 	struct timespec ts, rm;
    875 
    876 	if (!timerisset(&bw->bwstart)) {
    877 		gettimeofday(&bw->bwstart, NULL);
    878 		return;
    879 	}
    880 
    881 	bw->lamt += read_len;
    882 	if (bw->lamt < bw->thresh)
    883 		return;
    884 
    885 	gettimeofday(&bw->bwend, NULL);
    886 	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
    887 	if (!timerisset(&bw->bwend))
    888 		return;
    889 
    890 	bw->lamt *= 8;
    891 	waitlen = (double)1000000L * bw->lamt / bw->rate;
    892 
    893 	bw->bwstart.tv_sec = waitlen / 1000000L;
    894 	bw->bwstart.tv_usec = waitlen % 1000000L;
    895 
    896 	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
    897 		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
    898 
    899 		/* Adjust the wait time */
    900 		if (bw->bwend.tv_sec) {
    901 			bw->thresh /= 2;
    902 			if (bw->thresh < bw->buflen / 4)
    903 				bw->thresh = bw->buflen / 4;
    904 		} else if (bw->bwend.tv_usec < 10000) {
    905 			bw->thresh *= 2;
    906 			if (bw->thresh > bw->buflen * 8)
    907 				bw->thresh = bw->buflen * 8;
    908 		}
    909 
    910 		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
    911 		while (nanosleep(&ts, &rm) == -1) {
    912 			if (errno != EINTR)
    913 				break;
    914 			ts = rm;
    915 		}
    916 	}
    917 
    918 	bw->lamt = 0;
    919 	gettimeofday(&bw->bwstart, NULL);
    920 }
    921 
    922 /* Make a template filename for mk[sd]temp() */
    923 void
    924 mktemp_proto(char *s, size_t len)
    925 {
    926 	const char *tmpdir;
    927 	int r;
    928 
    929 	if ((tmpdir = getenv("TMPDIR")) != NULL) {
    930 		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
    931 		if (r > 0 && (size_t)r < len)
    932 			return;
    933 	}
    934 	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
    935 	if (r < 0 || (size_t)r >= len)
    936 		fatal("%s: template string too short", __func__);
    937 }
    938 
    939 static const struct {
    940 	const char *name;
    941 	int value;
    942 } ipqos[] = {
    943 	{ "af11", IPTOS_DSCP_AF11 },
    944 	{ "af12", IPTOS_DSCP_AF12 },
    945 	{ "af13", IPTOS_DSCP_AF13 },
    946 	{ "af14", IPTOS_DSCP_AF21 },
    947 	{ "af22", IPTOS_DSCP_AF22 },
    948 	{ "af23", IPTOS_DSCP_AF23 },
    949 	{ "af31", IPTOS_DSCP_AF31 },
    950 	{ "af32", IPTOS_DSCP_AF32 },
    951 	{ "af33", IPTOS_DSCP_AF33 },
    952 	{ "af41", IPTOS_DSCP_AF41 },
    953 	{ "af42", IPTOS_DSCP_AF42 },
    954 	{ "af43", IPTOS_DSCP_AF43 },
    955 	{ "cs0", IPTOS_DSCP_CS0 },
    956 	{ "cs1", IPTOS_DSCP_CS1 },
    957 	{ "cs2", IPTOS_DSCP_CS2 },
    958 	{ "cs3", IPTOS_DSCP_CS3 },
    959 	{ "cs4", IPTOS_DSCP_CS4 },
    960 	{ "cs5", IPTOS_DSCP_CS5 },
    961 	{ "cs6", IPTOS_DSCP_CS6 },
    962 	{ "cs7", IPTOS_DSCP_CS7 },
    963 	{ "ef", IPTOS_DSCP_EF },
    964 	{ "lowdelay", IPTOS_LOWDELAY },
    965 	{ "throughput", IPTOS_THROUGHPUT },
    966 	{ "reliability", IPTOS_RELIABILITY },
    967 	{ NULL, -1 }
    968 };
    969 
    970 int
    971 parse_ipqos(const char *cp)
    972 {
    973 	u_int i;
    974 	char *ep;
    975 	long val;
    976 
    977 	if (cp == NULL)
    978 		return -1;
    979 	for (i = 0; ipqos[i].name != NULL; i++) {
    980 		if (strcasecmp(cp, ipqos[i].name) == 0)
    981 			return ipqos[i].value;
    982 	}
    983 	/* Try parsing as an integer */
    984 	val = strtol(cp, &ep, 0);
    985 	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
    986 		return -1;
    987 	return val;
    988 }
    989 
    990 const char *
    991 iptos2str(int iptos)
    992 {
    993 	int i;
    994 	static char iptos_str[sizeof "0xff"];
    995 
    996 	for (i = 0; ipqos[i].name != NULL; i++) {
    997 		if (ipqos[i].value == iptos)
    998 			return ipqos[i].name;
    999 	}
   1000 	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
   1001 	return iptos_str;
   1002 }
   1003 void
   1004 sock_set_v6only(int s)
   1005 {
   1006 #ifdef IPV6_V6ONLY
   1007 	int on = 1;
   1008 
   1009 	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
   1010 	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
   1011 		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
   1012 #endif
   1013 }
   1014