xref: /dragonfly/crypto/openssh/misc.c (revision e9778795)
1 /* $OpenBSD: misc.c,v 1.105 2016/07/15 00:24:30 djm Exp $ */
2 /*
3  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
4  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "includes.h"
28 
29 #include <sys/types.h>
30 #include <sys/ioctl.h>
31 #include <sys/socket.h>
32 #include <sys/time.h>
33 #include <sys/un.h>
34 
35 #include <limits.h>
36 #include <stdarg.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <time.h>
41 #include <unistd.h>
42 
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #include <netinet/tcp.h>
47 
48 #include <ctype.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <netdb.h>
52 #ifdef HAVE_PATHS_H
53 # include <paths.h>
54 #include <pwd.h>
55 #endif
56 #ifdef SSH_TUN_OPENBSD
57 #include <net/if.h>
58 #endif
59 
60 #include "xmalloc.h"
61 #include "misc.h"
62 #include "log.h"
63 #include "ssh.h"
64 
65 /* remove newline at end of string */
66 char *
67 chop(char *s)
68 {
69 	char *t = s;
70 	while (*t) {
71 		if (*t == '\n' || *t == '\r') {
72 			*t = '\0';
73 			return s;
74 		}
75 		t++;
76 	}
77 	return s;
78 
79 }
80 
81 /* set/unset filedescriptor to non-blocking */
82 int
83 set_nonblock(int fd)
84 {
85 	int val;
86 
87 	val = fcntl(fd, F_GETFL);
88 	if (val < 0) {
89 		error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
90 		return (-1);
91 	}
92 	if (val & O_NONBLOCK) {
93 		debug3("fd %d is O_NONBLOCK", fd);
94 		return (0);
95 	}
96 	debug2("fd %d setting O_NONBLOCK", fd);
97 	val |= O_NONBLOCK;
98 	if (fcntl(fd, F_SETFL, val) == -1) {
99 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
100 		    strerror(errno));
101 		return (-1);
102 	}
103 	return (0);
104 }
105 
106 int
107 unset_nonblock(int fd)
108 {
109 	int val;
110 
111 	val = fcntl(fd, F_GETFL);
112 	if (val < 0) {
113 		error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
114 		return (-1);
115 	}
116 	if (!(val & O_NONBLOCK)) {
117 		debug3("fd %d is not O_NONBLOCK", fd);
118 		return (0);
119 	}
120 	debug("fd %d clearing O_NONBLOCK", fd);
121 	val &= ~O_NONBLOCK;
122 	if (fcntl(fd, F_SETFL, val) == -1) {
123 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
124 		    fd, strerror(errno));
125 		return (-1);
126 	}
127 	return (0);
128 }
129 
130 const char *
131 ssh_gai_strerror(int gaierr)
132 {
133 	if (gaierr == EAI_SYSTEM && errno != 0)
134 		return strerror(errno);
135 	return gai_strerror(gaierr);
136 }
137 
138 /* disable nagle on socket */
139 void
140 set_nodelay(int fd)
141 {
142 	int opt;
143 	socklen_t optlen;
144 
145 	optlen = sizeof opt;
146 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
147 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
148 		return;
149 	}
150 	if (opt == 1) {
151 		debug2("fd %d is TCP_NODELAY", fd);
152 		return;
153 	}
154 	opt = 1;
155 	debug2("fd %d setting TCP_NODELAY", fd);
156 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
157 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
158 }
159 
160 /* Characters considered whitespace in strsep calls. */
161 #define WHITESPACE " \t\r\n"
162 #define QUOTE	"\""
163 
164 /* return next token in configuration line */
165 char *
166 strdelim(char **s)
167 {
168 	char *old;
169 	int wspace = 0;
170 
171 	if (*s == NULL)
172 		return NULL;
173 
174 	old = *s;
175 
176 	*s = strpbrk(*s, WHITESPACE QUOTE "=");
177 	if (*s == NULL)
178 		return (old);
179 
180 	if (*s[0] == '\"') {
181 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
182 		/* Find matching quote */
183 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
184 			return (NULL);		/* no matching quote */
185 		} else {
186 			*s[0] = '\0';
187 			*s += strspn(*s + 1, WHITESPACE) + 1;
188 			return (old);
189 		}
190 	}
191 
192 	/* Allow only one '=' to be skipped */
193 	if (*s[0] == '=')
194 		wspace = 1;
195 	*s[0] = '\0';
196 
197 	/* Skip any extra whitespace after first token */
198 	*s += strspn(*s + 1, WHITESPACE) + 1;
199 	if (*s[0] == '=' && !wspace)
200 		*s += strspn(*s + 1, WHITESPACE) + 1;
201 
202 	return (old);
203 }
204 
205 struct passwd *
206 pwcopy(struct passwd *pw)
207 {
208 	struct passwd *copy = xcalloc(1, sizeof(*copy));
209 
210 	copy->pw_name = xstrdup(pw->pw_name);
211 	copy->pw_passwd = xstrdup(pw->pw_passwd);
212 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
213 	copy->pw_gecos = xstrdup(pw->pw_gecos);
214 #endif
215 	copy->pw_uid = pw->pw_uid;
216 	copy->pw_gid = pw->pw_gid;
217 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
218 	copy->pw_expire = pw->pw_expire;
219 #endif
220 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
221 	copy->pw_change = pw->pw_change;
222 #endif
223 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
224 	copy->pw_class = xstrdup(pw->pw_class);
225 #endif
226 	copy->pw_dir = xstrdup(pw->pw_dir);
227 	copy->pw_shell = xstrdup(pw->pw_shell);
228 	return copy;
229 }
230 
231 /*
232  * Convert ASCII string to TCP/IP port number.
233  * Port must be >=0 and <=65535.
234  * Return -1 if invalid.
235  */
236 int
237 a2port(const char *s)
238 {
239 	long long port;
240 	const char *errstr;
241 
242 	port = strtonum(s, 0, 65535, &errstr);
243 	if (errstr != NULL)
244 		return -1;
245 	return (int)port;
246 }
247 
248 int
249 a2tun(const char *s, int *remote)
250 {
251 	const char *errstr = NULL;
252 	char *sp, *ep;
253 	int tun;
254 
255 	if (remote != NULL) {
256 		*remote = SSH_TUNID_ANY;
257 		sp = xstrdup(s);
258 		if ((ep = strchr(sp, ':')) == NULL) {
259 			free(sp);
260 			return (a2tun(s, NULL));
261 		}
262 		ep[0] = '\0'; ep++;
263 		*remote = a2tun(ep, NULL);
264 		tun = a2tun(sp, NULL);
265 		free(sp);
266 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
267 	}
268 
269 	if (strcasecmp(s, "any") == 0)
270 		return (SSH_TUNID_ANY);
271 
272 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
273 	if (errstr != NULL)
274 		return (SSH_TUNID_ERR);
275 
276 	return (tun);
277 }
278 
279 #define SECONDS		1
280 #define MINUTES		(SECONDS * 60)
281 #define HOURS		(MINUTES * 60)
282 #define DAYS		(HOURS * 24)
283 #define WEEKS		(DAYS * 7)
284 
285 /*
286  * Convert a time string into seconds; format is
287  * a sequence of:
288  *      time[qualifier]
289  *
290  * Valid time qualifiers are:
291  *      <none>  seconds
292  *      s|S     seconds
293  *      m|M     minutes
294  *      h|H     hours
295  *      d|D     days
296  *      w|W     weeks
297  *
298  * Examples:
299  *      90m     90 minutes
300  *      1h30m   90 minutes
301  *      2d      2 days
302  *      1w      1 week
303  *
304  * Return -1 if time string is invalid.
305  */
306 long
307 convtime(const char *s)
308 {
309 	long total, secs;
310 	const char *p;
311 	char *endp;
312 
313 	errno = 0;
314 	total = 0;
315 	p = s;
316 
317 	if (p == NULL || *p == '\0')
318 		return -1;
319 
320 	while (*p) {
321 		secs = strtol(p, &endp, 10);
322 		if (p == endp ||
323 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
324 		    secs < 0)
325 			return -1;
326 
327 		switch (*endp++) {
328 		case '\0':
329 			endp--;
330 			break;
331 		case 's':
332 		case 'S':
333 			break;
334 		case 'm':
335 		case 'M':
336 			secs *= MINUTES;
337 			break;
338 		case 'h':
339 		case 'H':
340 			secs *= HOURS;
341 			break;
342 		case 'd':
343 		case 'D':
344 			secs *= DAYS;
345 			break;
346 		case 'w':
347 		case 'W':
348 			secs *= WEEKS;
349 			break;
350 		default:
351 			return -1;
352 		}
353 		total += secs;
354 		if (total < 0)
355 			return -1;
356 		p = endp;
357 	}
358 
359 	return total;
360 }
361 
362 /*
363  * Returns a standardized host+port identifier string.
364  * Caller must free returned string.
365  */
366 char *
367 put_host_port(const char *host, u_short port)
368 {
369 	char *hoststr;
370 
371 	if (port == 0 || port == SSH_DEFAULT_PORT)
372 		return(xstrdup(host));
373 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
374 		fatal("put_host_port: asprintf: %s", strerror(errno));
375 	debug3("put_host_port: %s", hoststr);
376 	return hoststr;
377 }
378 
379 /*
380  * Search for next delimiter between hostnames/addresses and ports.
381  * Argument may be modified (for termination).
382  * Returns *cp if parsing succeeds.
383  * *cp is set to the start of the next delimiter, if one was found.
384  * If this is the last field, *cp is set to NULL.
385  */
386 char *
387 hpdelim(char **cp)
388 {
389 	char *s, *old;
390 
391 	if (cp == NULL || *cp == NULL)
392 		return NULL;
393 
394 	old = s = *cp;
395 	if (*s == '[') {
396 		if ((s = strchr(s, ']')) == NULL)
397 			return NULL;
398 		else
399 			s++;
400 	} else if ((s = strpbrk(s, ":/")) == NULL)
401 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
402 
403 	switch (*s) {
404 	case '\0':
405 		*cp = NULL;	/* no more fields*/
406 		break;
407 
408 	case ':':
409 	case '/':
410 		*s = '\0';	/* terminate */
411 		*cp = s + 1;
412 		break;
413 
414 	default:
415 		return NULL;
416 	}
417 
418 	return old;
419 }
420 
421 char *
422 cleanhostname(char *host)
423 {
424 	if (*host == '[' && host[strlen(host) - 1] == ']') {
425 		host[strlen(host) - 1] = '\0';
426 		return (host + 1);
427 	} else
428 		return host;
429 }
430 
431 char *
432 colon(char *cp)
433 {
434 	int flag = 0;
435 
436 	if (*cp == ':')		/* Leading colon is part of file name. */
437 		return NULL;
438 	if (*cp == '[')
439 		flag = 1;
440 
441 	for (; *cp; ++cp) {
442 		if (*cp == '@' && *(cp+1) == '[')
443 			flag = 1;
444 		if (*cp == ']' && *(cp+1) == ':' && flag)
445 			return (cp+1);
446 		if (*cp == ':' && !flag)
447 			return (cp);
448 		if (*cp == '/')
449 			return NULL;
450 	}
451 	return NULL;
452 }
453 
454 /*
455  * Parse a [user@]host[:port] string.
456  * Caller must free returned user and host.
457  * Any of the pointer return arguments may be NULL (useful for syntax checking).
458  * If user was not specified then *userp will be set to NULL.
459  * If port was not specified then *portp will be -1.
460  * Returns 0 on success, -1 on failure.
461  */
462 int
463 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
464 {
465 	char *sdup, *cp, *tmp;
466 	char *user = NULL, *host = NULL;
467 	int port = -1, ret = -1;
468 
469 	if (userp != NULL)
470 		*userp = NULL;
471 	if (hostp != NULL)
472 		*hostp = NULL;
473 	if (portp != NULL)
474 		*portp = -1;
475 
476 	if ((sdup = tmp = strdup(s)) == NULL)
477 		return -1;
478 	/* Extract optional username */
479 	if ((cp = strchr(tmp, '@')) != NULL) {
480 		*cp = '\0';
481 		if (*tmp == '\0')
482 			goto out;
483 		if ((user = strdup(tmp)) == NULL)
484 			goto out;
485 		tmp = cp + 1;
486 	}
487 	/* Extract mandatory hostname */
488 	if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0')
489 		goto out;
490 	host = xstrdup(cleanhostname(cp));
491 	/* Convert and verify optional port */
492 	if (tmp != NULL && *tmp != '\0') {
493 		if ((port = a2port(tmp)) <= 0)
494 			goto out;
495 	}
496 	/* Success */
497 	if (userp != NULL) {
498 		*userp = user;
499 		user = NULL;
500 	}
501 	if (hostp != NULL) {
502 		*hostp = host;
503 		host = NULL;
504 	}
505 	if (portp != NULL)
506 		*portp = port;
507 	ret = 0;
508  out:
509 	free(sdup);
510 	free(user);
511 	free(host);
512 	return ret;
513 }
514 
515 /* function to assist building execv() arguments */
516 void
517 addargs(arglist *args, char *fmt, ...)
518 {
519 	va_list ap;
520 	char *cp;
521 	u_int nalloc;
522 	int r;
523 
524 	va_start(ap, fmt);
525 	r = vasprintf(&cp, fmt, ap);
526 	va_end(ap);
527 	if (r == -1)
528 		fatal("addargs: argument too long");
529 
530 	nalloc = args->nalloc;
531 	if (args->list == NULL) {
532 		nalloc = 32;
533 		args->num = 0;
534 	} else if (args->num+2 >= nalloc)
535 		nalloc *= 2;
536 
537 	args->list = xreallocarray(args->list, nalloc, sizeof(char *));
538 	args->nalloc = nalloc;
539 	args->list[args->num++] = cp;
540 	args->list[args->num] = NULL;
541 }
542 
543 void
544 replacearg(arglist *args, u_int which, char *fmt, ...)
545 {
546 	va_list ap;
547 	char *cp;
548 	int r;
549 
550 	va_start(ap, fmt);
551 	r = vasprintf(&cp, fmt, ap);
552 	va_end(ap);
553 	if (r == -1)
554 		fatal("replacearg: argument too long");
555 
556 	if (which >= args->num)
557 		fatal("replacearg: tried to replace invalid arg %d >= %d",
558 		    which, args->num);
559 	free(args->list[which]);
560 	args->list[which] = cp;
561 }
562 
563 void
564 freeargs(arglist *args)
565 {
566 	u_int i;
567 
568 	if (args->list != NULL) {
569 		for (i = 0; i < args->num; i++)
570 			free(args->list[i]);
571 		free(args->list);
572 		args->nalloc = args->num = 0;
573 		args->list = NULL;
574 	}
575 }
576 
577 /*
578  * Expands tildes in the file name.  Returns data allocated by xmalloc.
579  * Warning: this calls getpw*.
580  */
581 char *
582 tilde_expand_filename(const char *filename, uid_t uid)
583 {
584 	const char *path, *sep;
585 	char user[128], *ret;
586 	struct passwd *pw;
587 	u_int len, slash;
588 
589 	if (*filename != '~')
590 		return (xstrdup(filename));
591 	filename++;
592 
593 	path = strchr(filename, '/');
594 	if (path != NULL && path > filename) {		/* ~user/path */
595 		slash = path - filename;
596 		if (slash > sizeof(user) - 1)
597 			fatal("tilde_expand_filename: ~username too long");
598 		memcpy(user, filename, slash);
599 		user[slash] = '\0';
600 		if ((pw = getpwnam(user)) == NULL)
601 			fatal("tilde_expand_filename: No such user %s", user);
602 	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
603 		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
604 
605 	/* Make sure directory has a trailing '/' */
606 	len = strlen(pw->pw_dir);
607 	if (len == 0 || pw->pw_dir[len - 1] != '/')
608 		sep = "/";
609 	else
610 		sep = "";
611 
612 	/* Skip leading '/' from specified path */
613 	if (path != NULL)
614 		filename = path + 1;
615 
616 	if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX)
617 		fatal("tilde_expand_filename: Path too long");
618 
619 	return (ret);
620 }
621 
622 /*
623  * Expand a string with a set of %[char] escapes. A number of escapes may be
624  * specified as (char *escape_chars, char *replacement) pairs. The list must
625  * be terminated by a NULL escape_char. Returns replaced string in memory
626  * allocated by xmalloc.
627  */
628 char *
629 percent_expand(const char *string, ...)
630 {
631 #define EXPAND_MAX_KEYS	16
632 	u_int num_keys, i, j;
633 	struct {
634 		const char *key;
635 		const char *repl;
636 	} keys[EXPAND_MAX_KEYS];
637 	char buf[4096];
638 	va_list ap;
639 
640 	/* Gather keys */
641 	va_start(ap, string);
642 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
643 		keys[num_keys].key = va_arg(ap, char *);
644 		if (keys[num_keys].key == NULL)
645 			break;
646 		keys[num_keys].repl = va_arg(ap, char *);
647 		if (keys[num_keys].repl == NULL)
648 			fatal("%s: NULL replacement", __func__);
649 	}
650 	if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
651 		fatal("%s: too many keys", __func__);
652 	va_end(ap);
653 
654 	/* Expand string */
655 	*buf = '\0';
656 	for (i = 0; *string != '\0'; string++) {
657 		if (*string != '%') {
658  append:
659 			buf[i++] = *string;
660 			if (i >= sizeof(buf))
661 				fatal("%s: string too long", __func__);
662 			buf[i] = '\0';
663 			continue;
664 		}
665 		string++;
666 		/* %% case */
667 		if (*string == '%')
668 			goto append;
669 		if (*string == '\0')
670 			fatal("%s: invalid format", __func__);
671 		for (j = 0; j < num_keys; j++) {
672 			if (strchr(keys[j].key, *string) != NULL) {
673 				i = strlcat(buf, keys[j].repl, sizeof(buf));
674 				if (i >= sizeof(buf))
675 					fatal("%s: string too long", __func__);
676 				break;
677 			}
678 		}
679 		if (j >= num_keys)
680 			fatal("%s: unknown key %%%c", __func__, *string);
681 	}
682 	return (xstrdup(buf));
683 #undef EXPAND_MAX_KEYS
684 }
685 
686 /*
687  * Read an entire line from a public key file into a static buffer, discarding
688  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
689  */
690 int
691 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
692    u_long *lineno)
693 {
694 	while (fgets(buf, bufsz, f) != NULL) {
695 		if (buf[0] == '\0')
696 			continue;
697 		(*lineno)++;
698 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
699 			return 0;
700 		} else {
701 			debug("%s: %s line %lu exceeds size limit", __func__,
702 			    filename, *lineno);
703 			/* discard remainder of line */
704 			while (fgetc(f) != '\n' && !feof(f))
705 				;	/* nothing */
706 		}
707 	}
708 	return -1;
709 }
710 
711 int
712 tun_open(int tun, int mode)
713 {
714 #if defined(CUSTOM_SYS_TUN_OPEN)
715 	return (sys_tun_open(tun, mode));
716 #elif defined(SSH_TUN_OPENBSD)
717 	struct ifreq ifr;
718 	char name[100];
719 	int fd = -1, sock;
720 	const char *tunbase = "tun";
721 
722 	if (mode == SSH_TUNMODE_ETHERNET)
723 		tunbase = "tap";
724 
725 	/* Open the tunnel device */
726 	if (tun <= SSH_TUNID_MAX) {
727 		snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
728 		fd = open(name, O_RDWR);
729 	} else if (tun == SSH_TUNID_ANY) {
730 		for (tun = 100; tun >= 0; tun--) {
731 			snprintf(name, sizeof(name), "/dev/%s%d",
732 			    tunbase, tun);
733 			if ((fd = open(name, O_RDWR)) >= 0)
734 				break;
735 		}
736 	} else {
737 		debug("%s: invalid tunnel %u", __func__, tun);
738 		return -1;
739 	}
740 
741 	if (fd < 0) {
742 		debug("%s: %s open: %s", __func__, name, strerror(errno));
743 		return -1;
744 	}
745 
746 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
747 
748 	/* Bring interface up if it is not already */
749 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
750 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
751 		goto failed;
752 
753 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
754 		debug("%s: get interface %s flags: %s", __func__,
755 		    ifr.ifr_name, strerror(errno));
756 		goto failed;
757 	}
758 
759 	if (!(ifr.ifr_flags & IFF_UP)) {
760 		ifr.ifr_flags |= IFF_UP;
761 		if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
762 			debug("%s: activate interface %s: %s", __func__,
763 			    ifr.ifr_name, strerror(errno));
764 			goto failed;
765 		}
766 	}
767 
768 	close(sock);
769 	return fd;
770 
771  failed:
772 	if (fd >= 0)
773 		close(fd);
774 	if (sock >= 0)
775 		close(sock);
776 	return -1;
777 #else
778 	error("Tunnel interfaces are not supported on this platform");
779 	return (-1);
780 #endif
781 }
782 
783 void
784 sanitise_stdfd(void)
785 {
786 	int nullfd, dupfd;
787 
788 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
789 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
790 		    strerror(errno));
791 		exit(1);
792 	}
793 	while (++dupfd <= STDERR_FILENO) {
794 		/* Only populate closed fds. */
795 		if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
796 			if (dup2(nullfd, dupfd) == -1) {
797 				fprintf(stderr, "dup2: %s\n", strerror(errno));
798 				exit(1);
799 			}
800 		}
801 	}
802 	if (nullfd > STDERR_FILENO)
803 		close(nullfd);
804 }
805 
806 char *
807 tohex(const void *vp, size_t l)
808 {
809 	const u_char *p = (const u_char *)vp;
810 	char b[3], *r;
811 	size_t i, hl;
812 
813 	if (l > 65536)
814 		return xstrdup("tohex: length > 65536");
815 
816 	hl = l * 2 + 1;
817 	r = xcalloc(1, hl);
818 	for (i = 0; i < l; i++) {
819 		snprintf(b, sizeof(b), "%02x", p[i]);
820 		strlcat(r, b, hl);
821 	}
822 	return (r);
823 }
824 
825 u_int64_t
826 get_u64(const void *vp)
827 {
828 	const u_char *p = (const u_char *)vp;
829 	u_int64_t v;
830 
831 	v  = (u_int64_t)p[0] << 56;
832 	v |= (u_int64_t)p[1] << 48;
833 	v |= (u_int64_t)p[2] << 40;
834 	v |= (u_int64_t)p[3] << 32;
835 	v |= (u_int64_t)p[4] << 24;
836 	v |= (u_int64_t)p[5] << 16;
837 	v |= (u_int64_t)p[6] << 8;
838 	v |= (u_int64_t)p[7];
839 
840 	return (v);
841 }
842 
843 u_int32_t
844 get_u32(const void *vp)
845 {
846 	const u_char *p = (const u_char *)vp;
847 	u_int32_t v;
848 
849 	v  = (u_int32_t)p[0] << 24;
850 	v |= (u_int32_t)p[1] << 16;
851 	v |= (u_int32_t)p[2] << 8;
852 	v |= (u_int32_t)p[3];
853 
854 	return (v);
855 }
856 
857 u_int32_t
858 get_u32_le(const void *vp)
859 {
860 	const u_char *p = (const u_char *)vp;
861 	u_int32_t v;
862 
863 	v  = (u_int32_t)p[0];
864 	v |= (u_int32_t)p[1] << 8;
865 	v |= (u_int32_t)p[2] << 16;
866 	v |= (u_int32_t)p[3] << 24;
867 
868 	return (v);
869 }
870 
871 u_int16_t
872 get_u16(const void *vp)
873 {
874 	const u_char *p = (const u_char *)vp;
875 	u_int16_t v;
876 
877 	v  = (u_int16_t)p[0] << 8;
878 	v |= (u_int16_t)p[1];
879 
880 	return (v);
881 }
882 
883 void
884 put_u64(void *vp, u_int64_t v)
885 {
886 	u_char *p = (u_char *)vp;
887 
888 	p[0] = (u_char)(v >> 56) & 0xff;
889 	p[1] = (u_char)(v >> 48) & 0xff;
890 	p[2] = (u_char)(v >> 40) & 0xff;
891 	p[3] = (u_char)(v >> 32) & 0xff;
892 	p[4] = (u_char)(v >> 24) & 0xff;
893 	p[5] = (u_char)(v >> 16) & 0xff;
894 	p[6] = (u_char)(v >> 8) & 0xff;
895 	p[7] = (u_char)v & 0xff;
896 }
897 
898 void
899 put_u32(void *vp, u_int32_t v)
900 {
901 	u_char *p = (u_char *)vp;
902 
903 	p[0] = (u_char)(v >> 24) & 0xff;
904 	p[1] = (u_char)(v >> 16) & 0xff;
905 	p[2] = (u_char)(v >> 8) & 0xff;
906 	p[3] = (u_char)v & 0xff;
907 }
908 
909 void
910 put_u32_le(void *vp, u_int32_t v)
911 {
912 	u_char *p = (u_char *)vp;
913 
914 	p[0] = (u_char)v & 0xff;
915 	p[1] = (u_char)(v >> 8) & 0xff;
916 	p[2] = (u_char)(v >> 16) & 0xff;
917 	p[3] = (u_char)(v >> 24) & 0xff;
918 }
919 
920 void
921 put_u16(void *vp, u_int16_t v)
922 {
923 	u_char *p = (u_char *)vp;
924 
925 	p[0] = (u_char)(v >> 8) & 0xff;
926 	p[1] = (u_char)v & 0xff;
927 }
928 
929 void
930 ms_subtract_diff(struct timeval *start, int *ms)
931 {
932 	struct timeval diff, finish;
933 
934 	gettimeofday(&finish, NULL);
935 	timersub(&finish, start, &diff);
936 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
937 }
938 
939 void
940 ms_to_timeval(struct timeval *tv, int ms)
941 {
942 	if (ms < 0)
943 		ms = 0;
944 	tv->tv_sec = ms / 1000;
945 	tv->tv_usec = (ms % 1000) * 1000;
946 }
947 
948 time_t
949 monotime(void)
950 {
951 #if defined(HAVE_CLOCK_GETTIME) && \
952     (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
953 	struct timespec ts;
954 	static int gettime_failed = 0;
955 
956 	if (!gettime_failed) {
957 #if defined(CLOCK_BOOTTIME)
958 		if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
959 			return (ts.tv_sec);
960 #endif
961 #if defined(CLOCK_MONOTONIC)
962 		if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
963 			return (ts.tv_sec);
964 #endif
965 		debug3("clock_gettime: %s", strerror(errno));
966 		gettime_failed = 1;
967 	}
968 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
969 
970 	return time(NULL);
971 }
972 
973 double
974 monotime_double(void)
975 {
976 #if defined(HAVE_CLOCK_GETTIME) && \
977     (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
978 	struct timespec ts;
979 	static int gettime_failed = 0;
980 
981 	if (!gettime_failed) {
982 #if defined(CLOCK_BOOTTIME)
983 		if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
984 			return (ts.tv_sec + (double)ts.tv_nsec / 1000000000);
985 #endif
986 #if defined(CLOCK_MONOTONIC)
987 		if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
988 			return (ts.tv_sec + (double)ts.tv_nsec / 1000000000);
989 #endif
990 		debug3("clock_gettime: %s", strerror(errno));
991 		gettime_failed = 1;
992 	}
993 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
994 
995 	return (double)time(NULL);
996 }
997 
998 void
999 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
1000 {
1001 	bw->buflen = buflen;
1002 	bw->rate = kbps;
1003 	bw->thresh = bw->rate;
1004 	bw->lamt = 0;
1005 	timerclear(&bw->bwstart);
1006 	timerclear(&bw->bwend);
1007 }
1008 
1009 /* Callback from read/write loop to insert bandwidth-limiting delays */
1010 void
1011 bandwidth_limit(struct bwlimit *bw, size_t read_len)
1012 {
1013 	u_int64_t waitlen;
1014 	struct timespec ts, rm;
1015 
1016 	if (!timerisset(&bw->bwstart)) {
1017 		gettimeofday(&bw->bwstart, NULL);
1018 		return;
1019 	}
1020 
1021 	bw->lamt += read_len;
1022 	if (bw->lamt < bw->thresh)
1023 		return;
1024 
1025 	gettimeofday(&bw->bwend, NULL);
1026 	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
1027 	if (!timerisset(&bw->bwend))
1028 		return;
1029 
1030 	bw->lamt *= 8;
1031 	waitlen = (double)1000000L * bw->lamt / bw->rate;
1032 
1033 	bw->bwstart.tv_sec = waitlen / 1000000L;
1034 	bw->bwstart.tv_usec = waitlen % 1000000L;
1035 
1036 	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
1037 		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
1038 
1039 		/* Adjust the wait time */
1040 		if (bw->bwend.tv_sec) {
1041 			bw->thresh /= 2;
1042 			if (bw->thresh < bw->buflen / 4)
1043 				bw->thresh = bw->buflen / 4;
1044 		} else if (bw->bwend.tv_usec < 10000) {
1045 			bw->thresh *= 2;
1046 			if (bw->thresh > bw->buflen * 8)
1047 				bw->thresh = bw->buflen * 8;
1048 		}
1049 
1050 		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
1051 		while (nanosleep(&ts, &rm) == -1) {
1052 			if (errno != EINTR)
1053 				break;
1054 			ts = rm;
1055 		}
1056 	}
1057 
1058 	bw->lamt = 0;
1059 	gettimeofday(&bw->bwstart, NULL);
1060 }
1061 
1062 /* Make a template filename for mk[sd]temp() */
1063 void
1064 mktemp_proto(char *s, size_t len)
1065 {
1066 	const char *tmpdir;
1067 	int r;
1068 
1069 	if ((tmpdir = getenv("TMPDIR")) != NULL) {
1070 		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
1071 		if (r > 0 && (size_t)r < len)
1072 			return;
1073 	}
1074 	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
1075 	if (r < 0 || (size_t)r >= len)
1076 		fatal("%s: template string too short", __func__);
1077 }
1078 
1079 static const struct {
1080 	const char *name;
1081 	int value;
1082 } ipqos[] = {
1083 	{ "af11", IPTOS_DSCP_AF11 },
1084 	{ "af12", IPTOS_DSCP_AF12 },
1085 	{ "af13", IPTOS_DSCP_AF13 },
1086 	{ "af21", IPTOS_DSCP_AF21 },
1087 	{ "af22", IPTOS_DSCP_AF22 },
1088 	{ "af23", IPTOS_DSCP_AF23 },
1089 	{ "af31", IPTOS_DSCP_AF31 },
1090 	{ "af32", IPTOS_DSCP_AF32 },
1091 	{ "af33", IPTOS_DSCP_AF33 },
1092 	{ "af41", IPTOS_DSCP_AF41 },
1093 	{ "af42", IPTOS_DSCP_AF42 },
1094 	{ "af43", IPTOS_DSCP_AF43 },
1095 	{ "cs0", IPTOS_DSCP_CS0 },
1096 	{ "cs1", IPTOS_DSCP_CS1 },
1097 	{ "cs2", IPTOS_DSCP_CS2 },
1098 	{ "cs3", IPTOS_DSCP_CS3 },
1099 	{ "cs4", IPTOS_DSCP_CS4 },
1100 	{ "cs5", IPTOS_DSCP_CS5 },
1101 	{ "cs6", IPTOS_DSCP_CS6 },
1102 	{ "cs7", IPTOS_DSCP_CS7 },
1103 	{ "ef", IPTOS_DSCP_EF },
1104 	{ "lowdelay", IPTOS_LOWDELAY },
1105 	{ "throughput", IPTOS_THROUGHPUT },
1106 	{ "reliability", IPTOS_RELIABILITY },
1107 	{ NULL, -1 }
1108 };
1109 
1110 int
1111 parse_ipqos(const char *cp)
1112 {
1113 	u_int i;
1114 	char *ep;
1115 	long val;
1116 
1117 	if (cp == NULL)
1118 		return -1;
1119 	for (i = 0; ipqos[i].name != NULL; i++) {
1120 		if (strcasecmp(cp, ipqos[i].name) == 0)
1121 			return ipqos[i].value;
1122 	}
1123 	/* Try parsing as an integer */
1124 	val = strtol(cp, &ep, 0);
1125 	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1126 		return -1;
1127 	return val;
1128 }
1129 
1130 const char *
1131 iptos2str(int iptos)
1132 {
1133 	int i;
1134 	static char iptos_str[sizeof "0xff"];
1135 
1136 	for (i = 0; ipqos[i].name != NULL; i++) {
1137 		if (ipqos[i].value == iptos)
1138 			return ipqos[i].name;
1139 	}
1140 	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1141 	return iptos_str;
1142 }
1143 
1144 void
1145 lowercase(char *s)
1146 {
1147 	for (; *s; s++)
1148 		*s = tolower((u_char)*s);
1149 }
1150 
1151 int
1152 unix_listener(const char *path, int backlog, int unlink_first)
1153 {
1154 	struct sockaddr_un sunaddr;
1155 	int saved_errno, sock;
1156 
1157 	memset(&sunaddr, 0, sizeof(sunaddr));
1158 	sunaddr.sun_family = AF_UNIX;
1159 	if (strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1160 		error("%s: \"%s\" too long for Unix domain socket", __func__,
1161 		    path);
1162 		errno = ENAMETOOLONG;
1163 		return -1;
1164 	}
1165 
1166 	sock = socket(PF_UNIX, SOCK_STREAM, 0);
1167 	if (sock < 0) {
1168 		saved_errno = errno;
1169 		error("socket: %.100s", strerror(errno));
1170 		errno = saved_errno;
1171 		return -1;
1172 	}
1173 	if (unlink_first == 1) {
1174 		if (unlink(path) != 0 && errno != ENOENT)
1175 			error("unlink(%s): %.100s", path, strerror(errno));
1176 	}
1177 	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
1178 		saved_errno = errno;
1179 		error("bind: %.100s", strerror(errno));
1180 		close(sock);
1181 		error("%s: cannot bind to path: %s", __func__, path);
1182 		errno = saved_errno;
1183 		return -1;
1184 	}
1185 	if (listen(sock, backlog) < 0) {
1186 		saved_errno = errno;
1187 		error("listen: %.100s", strerror(errno));
1188 		close(sock);
1189 		unlink(path);
1190 		error("%s: cannot listen on path: %s", __func__, path);
1191 		errno = saved_errno;
1192 		return -1;
1193 	}
1194 	return sock;
1195 }
1196 
1197 void
1198 sock_set_v6only(int s)
1199 {
1200 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
1201 	int on = 1;
1202 
1203 	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1204 	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1205 		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1206 #endif
1207 }
1208 
1209 /*
1210  * Compares two strings that maybe be NULL. Returns non-zero if strings
1211  * are both NULL or are identical, returns zero otherwise.
1212  */
1213 static int
1214 strcmp_maybe_null(const char *a, const char *b)
1215 {
1216 	if ((a == NULL && b != NULL) || (a != NULL && b == NULL))
1217 		return 0;
1218 	if (a != NULL && strcmp(a, b) != 0)
1219 		return 0;
1220 	return 1;
1221 }
1222 
1223 /*
1224  * Compare two forwards, returning non-zero if they are identical or
1225  * zero otherwise.
1226  */
1227 int
1228 forward_equals(const struct Forward *a, const struct Forward *b)
1229 {
1230 	if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0)
1231 		return 0;
1232 	if (a->listen_port != b->listen_port)
1233 		return 0;
1234 	if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0)
1235 		return 0;
1236 	if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0)
1237 		return 0;
1238 	if (a->connect_port != b->connect_port)
1239 		return 0;
1240 	if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0)
1241 		return 0;
1242 	/* allocated_port and handle are not checked */
1243 	return 1;
1244 }
1245 
1246