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      1 /* $OpenBSD: misc.c,v 1.97 2015/04/24 01:36:00 deraadt 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 
     34 #include <limits.h>
     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 = pw->pw_passwd ? xstrdup(pw->pw_passwd) : NULL;
    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 = xreallocarray(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) >= PATH_MAX)
    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 }
   1118