xref: /openssh-portable/misc.c (revision 4594c762)
1 /* $OpenBSD: misc.c,v 1.146 2020/01/28 01:49:36 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/stat.h>
33 #include <sys/time.h>
34 #include <sys/wait.h>
35 #include <sys/un.h>
36 
37 #include <limits.h>
38 #ifdef HAVE_LIBGEN_H
39 # include <libgen.h>
40 #endif
41 #ifdef HAVE_POLL_H
42 #include <poll.h>
43 #endif
44 #include <signal.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <time.h>
50 #include <unistd.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/tcp.h>
56 #include <arpa/inet.h>
57 
58 #include <ctype.h>
59 #include <errno.h>
60 #include <fcntl.h>
61 #include <netdb.h>
62 #ifdef HAVE_PATHS_H
63 # include <paths.h>
64 #include <pwd.h>
65 #endif
66 #ifdef SSH_TUN_OPENBSD
67 #include <net/if.h>
68 #endif
69 
70 #include "xmalloc.h"
71 #include "misc.h"
72 #include "log.h"
73 #include "ssh.h"
74 #include "sshbuf.h"
75 #include "ssherr.h"
76 #include "platform.h"
77 
78 /* remove newline at end of string */
79 char *
80 chop(char *s)
81 {
82 	char *t = s;
83 	while (*t) {
84 		if (*t == '\n' || *t == '\r') {
85 			*t = '\0';
86 			return s;
87 		}
88 		t++;
89 	}
90 	return s;
91 
92 }
93 
94 /* set/unset filedescriptor to non-blocking */
95 int
96 set_nonblock(int fd)
97 {
98 	int val;
99 
100 	val = fcntl(fd, F_GETFL);
101 	if (val == -1) {
102 		error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
103 		return (-1);
104 	}
105 	if (val & O_NONBLOCK) {
106 		debug3("fd %d is O_NONBLOCK", fd);
107 		return (0);
108 	}
109 	debug2("fd %d setting O_NONBLOCK", fd);
110 	val |= O_NONBLOCK;
111 	if (fcntl(fd, F_SETFL, val) == -1) {
112 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
113 		    strerror(errno));
114 		return (-1);
115 	}
116 	return (0);
117 }
118 
119 int
120 unset_nonblock(int fd)
121 {
122 	int val;
123 
124 	val = fcntl(fd, F_GETFL);
125 	if (val == -1) {
126 		error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
127 		return (-1);
128 	}
129 	if (!(val & O_NONBLOCK)) {
130 		debug3("fd %d is not O_NONBLOCK", fd);
131 		return (0);
132 	}
133 	debug("fd %d clearing O_NONBLOCK", fd);
134 	val &= ~O_NONBLOCK;
135 	if (fcntl(fd, F_SETFL, val) == -1) {
136 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
137 		    fd, strerror(errno));
138 		return (-1);
139 	}
140 	return (0);
141 }
142 
143 const char *
144 ssh_gai_strerror(int gaierr)
145 {
146 	if (gaierr == EAI_SYSTEM && errno != 0)
147 		return strerror(errno);
148 	return gai_strerror(gaierr);
149 }
150 
151 /* disable nagle on socket */
152 void
153 set_nodelay(int fd)
154 {
155 	int opt;
156 	socklen_t optlen;
157 
158 	optlen = sizeof opt;
159 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
160 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
161 		return;
162 	}
163 	if (opt == 1) {
164 		debug2("fd %d is TCP_NODELAY", fd);
165 		return;
166 	}
167 	opt = 1;
168 	debug2("fd %d setting TCP_NODELAY", fd);
169 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
170 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
171 }
172 
173 /* Allow local port reuse in TIME_WAIT */
174 int
175 set_reuseaddr(int fd)
176 {
177 	int on = 1;
178 
179 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
180 		error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
181 		return -1;
182 	}
183 	return 0;
184 }
185 
186 /* Get/set routing domain */
187 char *
188 get_rdomain(int fd)
189 {
190 #if defined(HAVE_SYS_GET_RDOMAIN)
191 	return sys_get_rdomain(fd);
192 #elif defined(__OpenBSD__)
193 	int rtable;
194 	char *ret;
195 	socklen_t len = sizeof(rtable);
196 
197 	if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) {
198 		error("Failed to get routing domain for fd %d: %s",
199 		    fd, strerror(errno));
200 		return NULL;
201 	}
202 	xasprintf(&ret, "%d", rtable);
203 	return ret;
204 #else /* defined(__OpenBSD__) */
205 	return NULL;
206 #endif
207 }
208 
209 int
210 set_rdomain(int fd, const char *name)
211 {
212 #if defined(HAVE_SYS_SET_RDOMAIN)
213 	return sys_set_rdomain(fd, name);
214 #elif defined(__OpenBSD__)
215 	int rtable;
216 	const char *errstr;
217 
218 	if (name == NULL)
219 		return 0; /* default table */
220 
221 	rtable = (int)strtonum(name, 0, 255, &errstr);
222 	if (errstr != NULL) {
223 		/* Shouldn't happen */
224 		error("Invalid routing domain \"%s\": %s", name, errstr);
225 		return -1;
226 	}
227 	if (setsockopt(fd, SOL_SOCKET, SO_RTABLE,
228 	    &rtable, sizeof(rtable)) == -1) {
229 		error("Failed to set routing domain %d on fd %d: %s",
230 		    rtable, fd, strerror(errno));
231 		return -1;
232 	}
233 	return 0;
234 #else /* defined(__OpenBSD__) */
235 	error("Setting routing domain is not supported on this platform");
236 	return -1;
237 #endif
238 }
239 
240 /*
241  * Wait up to *timeoutp milliseconds for events on fd. Updates
242  * *timeoutp with time remaining.
243  * Returns 0 if fd ready or -1 on timeout or error (see errno).
244  */
245 static int
246 waitfd(int fd, int *timeoutp, short events)
247 {
248 	struct pollfd pfd;
249 	struct timeval t_start;
250 	int oerrno, r;
251 
252 	monotime_tv(&t_start);
253 	pfd.fd = fd;
254 	pfd.events = events;
255 	for (; *timeoutp >= 0;) {
256 		r = poll(&pfd, 1, *timeoutp);
257 		oerrno = errno;
258 		ms_subtract_diff(&t_start, timeoutp);
259 		errno = oerrno;
260 		if (r > 0)
261 			return 0;
262 		else if (r == -1 && errno != EAGAIN)
263 			return -1;
264 		else if (r == 0)
265 			break;
266 	}
267 	/* timeout */
268 	errno = ETIMEDOUT;
269 	return -1;
270 }
271 
272 /*
273  * Wait up to *timeoutp milliseconds for fd to be readable. Updates
274  * *timeoutp with time remaining.
275  * Returns 0 if fd ready or -1 on timeout or error (see errno).
276  */
277 int
278 waitrfd(int fd, int *timeoutp) {
279 	return waitfd(fd, timeoutp, POLLIN);
280 }
281 
282 /*
283  * Attempt a non-blocking connect(2) to the specified address, waiting up to
284  * *timeoutp milliseconds for the connection to complete. If the timeout is
285  * <=0, then wait indefinitely.
286  *
287  * Returns 0 on success or -1 on failure.
288  */
289 int
290 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
291     socklen_t addrlen, int *timeoutp)
292 {
293 	int optval = 0;
294 	socklen_t optlen = sizeof(optval);
295 
296 	/* No timeout: just do a blocking connect() */
297 	if (timeoutp == NULL || *timeoutp <= 0)
298 		return connect(sockfd, serv_addr, addrlen);
299 
300 	set_nonblock(sockfd);
301 	if (connect(sockfd, serv_addr, addrlen) == 0) {
302 		/* Succeeded already? */
303 		unset_nonblock(sockfd);
304 		return 0;
305 	} else if (errno != EINPROGRESS)
306 		return -1;
307 
308 	if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1)
309 		return -1;
310 
311 	/* Completed or failed */
312 	if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) {
313 		debug("getsockopt: %s", strerror(errno));
314 		return -1;
315 	}
316 	if (optval != 0) {
317 		errno = optval;
318 		return -1;
319 	}
320 	unset_nonblock(sockfd);
321 	return 0;
322 }
323 
324 /* Characters considered whitespace in strsep calls. */
325 #define WHITESPACE " \t\r\n"
326 #define QUOTE	"\""
327 
328 /* return next token in configuration line */
329 static char *
330 strdelim_internal(char **s, int split_equals)
331 {
332 	char *old;
333 	int wspace = 0;
334 
335 	if (*s == NULL)
336 		return NULL;
337 
338 	old = *s;
339 
340 	*s = strpbrk(*s,
341 	    split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE);
342 	if (*s == NULL)
343 		return (old);
344 
345 	if (*s[0] == '\"') {
346 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
347 		/* Find matching quote */
348 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
349 			return (NULL);		/* no matching quote */
350 		} else {
351 			*s[0] = '\0';
352 			*s += strspn(*s + 1, WHITESPACE) + 1;
353 			return (old);
354 		}
355 	}
356 
357 	/* Allow only one '=' to be skipped */
358 	if (split_equals && *s[0] == '=')
359 		wspace = 1;
360 	*s[0] = '\0';
361 
362 	/* Skip any extra whitespace after first token */
363 	*s += strspn(*s + 1, WHITESPACE) + 1;
364 	if (split_equals && *s[0] == '=' && !wspace)
365 		*s += strspn(*s + 1, WHITESPACE) + 1;
366 
367 	return (old);
368 }
369 
370 /*
371  * Return next token in configuration line; splts on whitespace or a
372  * single '=' character.
373  */
374 char *
375 strdelim(char **s)
376 {
377 	return strdelim_internal(s, 1);
378 }
379 
380 /*
381  * Return next token in configuration line; splts on whitespace only.
382  */
383 char *
384 strdelimw(char **s)
385 {
386 	return strdelim_internal(s, 0);
387 }
388 
389 struct passwd *
390 pwcopy(struct passwd *pw)
391 {
392 	struct passwd *copy = xcalloc(1, sizeof(*copy));
393 
394 	copy->pw_name = xstrdup(pw->pw_name);
395 	copy->pw_passwd = xstrdup(pw->pw_passwd);
396 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
397 	copy->pw_gecos = xstrdup(pw->pw_gecos);
398 #endif
399 	copy->pw_uid = pw->pw_uid;
400 	copy->pw_gid = pw->pw_gid;
401 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
402 	copy->pw_expire = pw->pw_expire;
403 #endif
404 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
405 	copy->pw_change = pw->pw_change;
406 #endif
407 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
408 	copy->pw_class = xstrdup(pw->pw_class);
409 #endif
410 	copy->pw_dir = xstrdup(pw->pw_dir);
411 	copy->pw_shell = xstrdup(pw->pw_shell);
412 	return copy;
413 }
414 
415 /*
416  * Convert ASCII string to TCP/IP port number.
417  * Port must be >=0 and <=65535.
418  * Return -1 if invalid.
419  */
420 int
421 a2port(const char *s)
422 {
423 	struct servent *se;
424 	long long port;
425 	const char *errstr;
426 
427 	port = strtonum(s, 0, 65535, &errstr);
428 	if (errstr == NULL)
429 		return (int)port;
430 	if ((se = getservbyname(s, "tcp")) != NULL)
431 		return ntohs(se->s_port);
432 	return -1;
433 }
434 
435 int
436 a2tun(const char *s, int *remote)
437 {
438 	const char *errstr = NULL;
439 	char *sp, *ep;
440 	int tun;
441 
442 	if (remote != NULL) {
443 		*remote = SSH_TUNID_ANY;
444 		sp = xstrdup(s);
445 		if ((ep = strchr(sp, ':')) == NULL) {
446 			free(sp);
447 			return (a2tun(s, NULL));
448 		}
449 		ep[0] = '\0'; ep++;
450 		*remote = a2tun(ep, NULL);
451 		tun = a2tun(sp, NULL);
452 		free(sp);
453 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
454 	}
455 
456 	if (strcasecmp(s, "any") == 0)
457 		return (SSH_TUNID_ANY);
458 
459 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
460 	if (errstr != NULL)
461 		return (SSH_TUNID_ERR);
462 
463 	return (tun);
464 }
465 
466 #define SECONDS		1
467 #define MINUTES		(SECONDS * 60)
468 #define HOURS		(MINUTES * 60)
469 #define DAYS		(HOURS * 24)
470 #define WEEKS		(DAYS * 7)
471 
472 /*
473  * Convert a time string into seconds; format is
474  * a sequence of:
475  *      time[qualifier]
476  *
477  * Valid time qualifiers are:
478  *      <none>  seconds
479  *      s|S     seconds
480  *      m|M     minutes
481  *      h|H     hours
482  *      d|D     days
483  *      w|W     weeks
484  *
485  * Examples:
486  *      90m     90 minutes
487  *      1h30m   90 minutes
488  *      2d      2 days
489  *      1w      1 week
490  *
491  * Return -1 if time string is invalid.
492  */
493 long
494 convtime(const char *s)
495 {
496 	long total, secs, multiplier = 1;
497 	const char *p;
498 	char *endp;
499 
500 	errno = 0;
501 	total = 0;
502 	p = s;
503 
504 	if (p == NULL || *p == '\0')
505 		return -1;
506 
507 	while (*p) {
508 		secs = strtol(p, &endp, 10);
509 		if (p == endp ||
510 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
511 		    secs < 0)
512 			return -1;
513 
514 		switch (*endp++) {
515 		case '\0':
516 			endp--;
517 			break;
518 		case 's':
519 		case 'S':
520 			break;
521 		case 'm':
522 		case 'M':
523 			multiplier = MINUTES;
524 			break;
525 		case 'h':
526 		case 'H':
527 			multiplier = HOURS;
528 			break;
529 		case 'd':
530 		case 'D':
531 			multiplier = DAYS;
532 			break;
533 		case 'w':
534 		case 'W':
535 			multiplier = WEEKS;
536 			break;
537 		default:
538 			return -1;
539 		}
540 		if (secs >= LONG_MAX / multiplier)
541 			return -1;
542 		secs *= multiplier;
543 		if  (total >= LONG_MAX - secs)
544 			return -1;
545 		total += secs;
546 		if (total < 0)
547 			return -1;
548 		p = endp;
549 	}
550 
551 	return total;
552 }
553 
554 /*
555  * Returns a standardized host+port identifier string.
556  * Caller must free returned string.
557  */
558 char *
559 put_host_port(const char *host, u_short port)
560 {
561 	char *hoststr;
562 
563 	if (port == 0 || port == SSH_DEFAULT_PORT)
564 		return(xstrdup(host));
565 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1)
566 		fatal("put_host_port: asprintf: %s", strerror(errno));
567 	debug3("put_host_port: %s", hoststr);
568 	return hoststr;
569 }
570 
571 /*
572  * Search for next delimiter between hostnames/addresses and ports.
573  * Argument may be modified (for termination).
574  * Returns *cp if parsing succeeds.
575  * *cp is set to the start of the next field, if one was found.
576  * The delimiter char, if present, is stored in delim.
577  * If this is the last field, *cp is set to NULL.
578  */
579 char *
580 hpdelim2(char **cp, char *delim)
581 {
582 	char *s, *old;
583 
584 	if (cp == NULL || *cp == NULL)
585 		return NULL;
586 
587 	old = s = *cp;
588 	if (*s == '[') {
589 		if ((s = strchr(s, ']')) == NULL)
590 			return NULL;
591 		else
592 			s++;
593 	} else if ((s = strpbrk(s, ":/")) == NULL)
594 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
595 
596 	switch (*s) {
597 	case '\0':
598 		*cp = NULL;	/* no more fields*/
599 		break;
600 
601 	case ':':
602 	case '/':
603 		if (delim != NULL)
604 			*delim = *s;
605 		*s = '\0';	/* terminate */
606 		*cp = s + 1;
607 		break;
608 
609 	default:
610 		return NULL;
611 	}
612 
613 	return old;
614 }
615 
616 char *
617 hpdelim(char **cp)
618 {
619 	return hpdelim2(cp, NULL);
620 }
621 
622 char *
623 cleanhostname(char *host)
624 {
625 	if (*host == '[' && host[strlen(host) - 1] == ']') {
626 		host[strlen(host) - 1] = '\0';
627 		return (host + 1);
628 	} else
629 		return host;
630 }
631 
632 char *
633 colon(char *cp)
634 {
635 	int flag = 0;
636 
637 	if (*cp == ':')		/* Leading colon is part of file name. */
638 		return NULL;
639 	if (*cp == '[')
640 		flag = 1;
641 
642 	for (; *cp; ++cp) {
643 		if (*cp == '@' && *(cp+1) == '[')
644 			flag = 1;
645 		if (*cp == ']' && *(cp+1) == ':' && flag)
646 			return (cp+1);
647 		if (*cp == ':' && !flag)
648 			return (cp);
649 		if (*cp == '/')
650 			return NULL;
651 	}
652 	return NULL;
653 }
654 
655 /*
656  * Parse a [user@]host:[path] string.
657  * Caller must free returned user, host and path.
658  * Any of the pointer return arguments may be NULL (useful for syntax checking).
659  * If user was not specified then *userp will be set to NULL.
660  * If host was not specified then *hostp will be set to NULL.
661  * If path was not specified then *pathp will be set to ".".
662  * Returns 0 on success, -1 on failure.
663  */
664 int
665 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp)
666 {
667 	char *user = NULL, *host = NULL, *path = NULL;
668 	char *sdup, *tmp;
669 	int ret = -1;
670 
671 	if (userp != NULL)
672 		*userp = NULL;
673 	if (hostp != NULL)
674 		*hostp = NULL;
675 	if (pathp != NULL)
676 		*pathp = NULL;
677 
678 	sdup = xstrdup(s);
679 
680 	/* Check for remote syntax: [user@]host:[path] */
681 	if ((tmp = colon(sdup)) == NULL)
682 		goto out;
683 
684 	/* Extract optional path */
685 	*tmp++ = '\0';
686 	if (*tmp == '\0')
687 		tmp = ".";
688 	path = xstrdup(tmp);
689 
690 	/* Extract optional user and mandatory host */
691 	tmp = strrchr(sdup, '@');
692 	if (tmp != NULL) {
693 		*tmp++ = '\0';
694 		host = xstrdup(cleanhostname(tmp));
695 		if (*sdup != '\0')
696 			user = xstrdup(sdup);
697 	} else {
698 		host = xstrdup(cleanhostname(sdup));
699 		user = NULL;
700 	}
701 
702 	/* Success */
703 	if (userp != NULL) {
704 		*userp = user;
705 		user = NULL;
706 	}
707 	if (hostp != NULL) {
708 		*hostp = host;
709 		host = NULL;
710 	}
711 	if (pathp != NULL) {
712 		*pathp = path;
713 		path = NULL;
714 	}
715 	ret = 0;
716 out:
717 	free(sdup);
718 	free(user);
719 	free(host);
720 	free(path);
721 	return ret;
722 }
723 
724 /*
725  * Parse a [user@]host[:port] string.
726  * Caller must free returned user and host.
727  * Any of the pointer return arguments may be NULL (useful for syntax checking).
728  * If user was not specified then *userp will be set to NULL.
729  * If port was not specified then *portp will be -1.
730  * Returns 0 on success, -1 on failure.
731  */
732 int
733 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
734 {
735 	char *sdup, *cp, *tmp;
736 	char *user = NULL, *host = NULL;
737 	int port = -1, ret = -1;
738 
739 	if (userp != NULL)
740 		*userp = NULL;
741 	if (hostp != NULL)
742 		*hostp = NULL;
743 	if (portp != NULL)
744 		*portp = -1;
745 
746 	if ((sdup = tmp = strdup(s)) == NULL)
747 		return -1;
748 	/* Extract optional username */
749 	if ((cp = strrchr(tmp, '@')) != NULL) {
750 		*cp = '\0';
751 		if (*tmp == '\0')
752 			goto out;
753 		if ((user = strdup(tmp)) == NULL)
754 			goto out;
755 		tmp = cp + 1;
756 	}
757 	/* Extract mandatory hostname */
758 	if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0')
759 		goto out;
760 	host = xstrdup(cleanhostname(cp));
761 	/* Convert and verify optional port */
762 	if (tmp != NULL && *tmp != '\0') {
763 		if ((port = a2port(tmp)) <= 0)
764 			goto out;
765 	}
766 	/* Success */
767 	if (userp != NULL) {
768 		*userp = user;
769 		user = NULL;
770 	}
771 	if (hostp != NULL) {
772 		*hostp = host;
773 		host = NULL;
774 	}
775 	if (portp != NULL)
776 		*portp = port;
777 	ret = 0;
778  out:
779 	free(sdup);
780 	free(user);
781 	free(host);
782 	return ret;
783 }
784 
785 /*
786  * Converts a two-byte hex string to decimal.
787  * Returns the decimal value or -1 for invalid input.
788  */
789 static int
790 hexchar(const char *s)
791 {
792 	unsigned char result[2];
793 	int i;
794 
795 	for (i = 0; i < 2; i++) {
796 		if (s[i] >= '0' && s[i] <= '9')
797 			result[i] = (unsigned char)(s[i] - '0');
798 		else if (s[i] >= 'a' && s[i] <= 'f')
799 			result[i] = (unsigned char)(s[i] - 'a') + 10;
800 		else if (s[i] >= 'A' && s[i] <= 'F')
801 			result[i] = (unsigned char)(s[i] - 'A') + 10;
802 		else
803 			return -1;
804 	}
805 	return (result[0] << 4) | result[1];
806 }
807 
808 /*
809  * Decode an url-encoded string.
810  * Returns a newly allocated string on success or NULL on failure.
811  */
812 static char *
813 urldecode(const char *src)
814 {
815 	char *ret, *dst;
816 	int ch;
817 
818 	ret = xmalloc(strlen(src) + 1);
819 	for (dst = ret; *src != '\0'; src++) {
820 		switch (*src) {
821 		case '+':
822 			*dst++ = ' ';
823 			break;
824 		case '%':
825 			if (!isxdigit((unsigned char)src[1]) ||
826 			    !isxdigit((unsigned char)src[2]) ||
827 			    (ch = hexchar(src + 1)) == -1) {
828 				free(ret);
829 				return NULL;
830 			}
831 			*dst++ = ch;
832 			src += 2;
833 			break;
834 		default:
835 			*dst++ = *src;
836 			break;
837 		}
838 	}
839 	*dst = '\0';
840 
841 	return ret;
842 }
843 
844 /*
845  * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI.
846  * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04
847  * Either user or path may be url-encoded (but not host or port).
848  * Caller must free returned user, host and path.
849  * Any of the pointer return arguments may be NULL (useful for syntax checking)
850  * but the scheme must always be specified.
851  * If user was not specified then *userp will be set to NULL.
852  * If port was not specified then *portp will be -1.
853  * If path was not specified then *pathp will be set to NULL.
854  * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri.
855  */
856 int
857 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp,
858     int *portp, char **pathp)
859 {
860 	char *uridup, *cp, *tmp, ch;
861 	char *user = NULL, *host = NULL, *path = NULL;
862 	int port = -1, ret = -1;
863 	size_t len;
864 
865 	len = strlen(scheme);
866 	if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0)
867 		return 1;
868 	uri += len + 3;
869 
870 	if (userp != NULL)
871 		*userp = NULL;
872 	if (hostp != NULL)
873 		*hostp = NULL;
874 	if (portp != NULL)
875 		*portp = -1;
876 	if (pathp != NULL)
877 		*pathp = NULL;
878 
879 	uridup = tmp = xstrdup(uri);
880 
881 	/* Extract optional ssh-info (username + connection params) */
882 	if ((cp = strchr(tmp, '@')) != NULL) {
883 		char *delim;
884 
885 		*cp = '\0';
886 		/* Extract username and connection params */
887 		if ((delim = strchr(tmp, ';')) != NULL) {
888 			/* Just ignore connection params for now */
889 			*delim = '\0';
890 		}
891 		if (*tmp == '\0') {
892 			/* Empty username */
893 			goto out;
894 		}
895 		if ((user = urldecode(tmp)) == NULL)
896 			goto out;
897 		tmp = cp + 1;
898 	}
899 
900 	/* Extract mandatory hostname */
901 	if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0')
902 		goto out;
903 	host = xstrdup(cleanhostname(cp));
904 	if (!valid_domain(host, 0, NULL))
905 		goto out;
906 
907 	if (tmp != NULL && *tmp != '\0') {
908 		if (ch == ':') {
909 			/* Convert and verify port. */
910 			if ((cp = strchr(tmp, '/')) != NULL)
911 				*cp = '\0';
912 			if ((port = a2port(tmp)) <= 0)
913 				goto out;
914 			tmp = cp ? cp + 1 : NULL;
915 		}
916 		if (tmp != NULL && *tmp != '\0') {
917 			/* Extract optional path */
918 			if ((path = urldecode(tmp)) == NULL)
919 				goto out;
920 		}
921 	}
922 
923 	/* Success */
924 	if (userp != NULL) {
925 		*userp = user;
926 		user = NULL;
927 	}
928 	if (hostp != NULL) {
929 		*hostp = host;
930 		host = NULL;
931 	}
932 	if (portp != NULL)
933 		*portp = port;
934 	if (pathp != NULL) {
935 		*pathp = path;
936 		path = NULL;
937 	}
938 	ret = 0;
939  out:
940 	free(uridup);
941 	free(user);
942 	free(host);
943 	free(path);
944 	return ret;
945 }
946 
947 /* function to assist building execv() arguments */
948 void
949 addargs(arglist *args, char *fmt, ...)
950 {
951 	va_list ap;
952 	char *cp;
953 	u_int nalloc;
954 	int r;
955 
956 	va_start(ap, fmt);
957 	r = vasprintf(&cp, fmt, ap);
958 	va_end(ap);
959 	if (r == -1)
960 		fatal("addargs: argument too long");
961 
962 	nalloc = args->nalloc;
963 	if (args->list == NULL) {
964 		nalloc = 32;
965 		args->num = 0;
966 	} else if (args->num+2 >= nalloc)
967 		nalloc *= 2;
968 
969 	args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *));
970 	args->nalloc = nalloc;
971 	args->list[args->num++] = cp;
972 	args->list[args->num] = NULL;
973 }
974 
975 void
976 replacearg(arglist *args, u_int which, char *fmt, ...)
977 {
978 	va_list ap;
979 	char *cp;
980 	int r;
981 
982 	va_start(ap, fmt);
983 	r = vasprintf(&cp, fmt, ap);
984 	va_end(ap);
985 	if (r == -1)
986 		fatal("replacearg: argument too long");
987 
988 	if (which >= args->num)
989 		fatal("replacearg: tried to replace invalid arg %d >= %d",
990 		    which, args->num);
991 	free(args->list[which]);
992 	args->list[which] = cp;
993 }
994 
995 void
996 freeargs(arglist *args)
997 {
998 	u_int i;
999 
1000 	if (args->list != NULL) {
1001 		for (i = 0; i < args->num; i++)
1002 			free(args->list[i]);
1003 		free(args->list);
1004 		args->nalloc = args->num = 0;
1005 		args->list = NULL;
1006 	}
1007 }
1008 
1009 /*
1010  * Expands tildes in the file name.  Returns data allocated by xmalloc.
1011  * Warning: this calls getpw*.
1012  */
1013 char *
1014 tilde_expand_filename(const char *filename, uid_t uid)
1015 {
1016 	const char *path, *sep;
1017 	char user[128], *ret;
1018 	struct passwd *pw;
1019 	u_int len, slash;
1020 
1021 	if (*filename != '~')
1022 		return (xstrdup(filename));
1023 	filename++;
1024 
1025 	path = strchr(filename, '/');
1026 	if (path != NULL && path > filename) {		/* ~user/path */
1027 		slash = path - filename;
1028 		if (slash > sizeof(user) - 1)
1029 			fatal("tilde_expand_filename: ~username too long");
1030 		memcpy(user, filename, slash);
1031 		user[slash] = '\0';
1032 		if ((pw = getpwnam(user)) == NULL)
1033 			fatal("tilde_expand_filename: No such user %s", user);
1034 	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
1035 		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
1036 
1037 	/* Make sure directory has a trailing '/' */
1038 	len = strlen(pw->pw_dir);
1039 	if (len == 0 || pw->pw_dir[len - 1] != '/')
1040 		sep = "/";
1041 	else
1042 		sep = "";
1043 
1044 	/* Skip leading '/' from specified path */
1045 	if (path != NULL)
1046 		filename = path + 1;
1047 
1048 	if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX)
1049 		fatal("tilde_expand_filename: Path too long");
1050 
1051 	return (ret);
1052 }
1053 
1054 /*
1055  * Expand a string with a set of %[char] escapes. A number of escapes may be
1056  * specified as (char *escape_chars, char *replacement) pairs. The list must
1057  * be terminated by a NULL escape_char. Returns replaced string in memory
1058  * allocated by xmalloc.
1059  */
1060 char *
1061 percent_expand(const char *string, ...)
1062 {
1063 #define EXPAND_MAX_KEYS	16
1064 	u_int num_keys, i;
1065 	struct {
1066 		const char *key;
1067 		const char *repl;
1068 	} keys[EXPAND_MAX_KEYS];
1069 	struct sshbuf *buf;
1070 	va_list ap;
1071 	int r;
1072 	char *ret;
1073 
1074 	if ((buf = sshbuf_new()) == NULL)
1075 		fatal("%s: sshbuf_new failed", __func__);
1076 
1077 	/* Gather keys */
1078 	va_start(ap, string);
1079 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
1080 		keys[num_keys].key = va_arg(ap, char *);
1081 		if (keys[num_keys].key == NULL)
1082 			break;
1083 		keys[num_keys].repl = va_arg(ap, char *);
1084 		if (keys[num_keys].repl == NULL)
1085 			fatal("%s: NULL replacement", __func__);
1086 	}
1087 	if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
1088 		fatal("%s: too many keys", __func__);
1089 	va_end(ap);
1090 
1091 	/* Expand string */
1092 	for (i = 0; *string != '\0'; string++) {
1093 		if (*string != '%') {
1094  append:
1095 			if ((r = sshbuf_put_u8(buf, *string)) != 0) {
1096 				fatal("%s: sshbuf_put_u8: %s",
1097 				    __func__, ssh_err(r));
1098 			}
1099 			continue;
1100 		}
1101 		string++;
1102 		/* %% case */
1103 		if (*string == '%')
1104 			goto append;
1105 		if (*string == '\0')
1106 			fatal("%s: invalid format", __func__);
1107 		for (i = 0; i < num_keys; i++) {
1108 			if (strchr(keys[i].key, *string) != NULL) {
1109 				if ((r = sshbuf_put(buf, keys[i].repl,
1110 				    strlen(keys[i].repl))) != 0) {
1111 					fatal("%s: sshbuf_put: %s",
1112 					    __func__, ssh_err(r));
1113 				}
1114 				break;
1115 			}
1116 		}
1117 		if (i >= num_keys)
1118 			fatal("%s: unknown key %%%c", __func__, *string);
1119 	}
1120 	if ((ret = sshbuf_dup_string(buf)) == NULL)
1121 		fatal("%s: sshbuf_dup_string failed", __func__);
1122 	sshbuf_free(buf);
1123 	return ret;
1124 #undef EXPAND_MAX_KEYS
1125 }
1126 
1127 int
1128 tun_open(int tun, int mode, char **ifname)
1129 {
1130 #if defined(CUSTOM_SYS_TUN_OPEN)
1131 	return (sys_tun_open(tun, mode, ifname));
1132 #elif defined(SSH_TUN_OPENBSD)
1133 	struct ifreq ifr;
1134 	char name[100];
1135 	int fd = -1, sock;
1136 	const char *tunbase = "tun";
1137 
1138 	if (ifname != NULL)
1139 		*ifname = NULL;
1140 
1141 	if (mode == SSH_TUNMODE_ETHERNET)
1142 		tunbase = "tap";
1143 
1144 	/* Open the tunnel device */
1145 	if (tun <= SSH_TUNID_MAX) {
1146 		snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
1147 		fd = open(name, O_RDWR);
1148 	} else if (tun == SSH_TUNID_ANY) {
1149 		for (tun = 100; tun >= 0; tun--) {
1150 			snprintf(name, sizeof(name), "/dev/%s%d",
1151 			    tunbase, tun);
1152 			if ((fd = open(name, O_RDWR)) >= 0)
1153 				break;
1154 		}
1155 	} else {
1156 		debug("%s: invalid tunnel %u", __func__, tun);
1157 		return -1;
1158 	}
1159 
1160 	if (fd == -1) {
1161 		debug("%s: %s open: %s", __func__, name, strerror(errno));
1162 		return -1;
1163 	}
1164 
1165 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
1166 
1167 	/* Bring interface up if it is not already */
1168 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
1169 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1170 		goto failed;
1171 
1172 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
1173 		debug("%s: get interface %s flags: %s", __func__,
1174 		    ifr.ifr_name, strerror(errno));
1175 		goto failed;
1176 	}
1177 
1178 	if (!(ifr.ifr_flags & IFF_UP)) {
1179 		ifr.ifr_flags |= IFF_UP;
1180 		if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
1181 			debug("%s: activate interface %s: %s", __func__,
1182 			    ifr.ifr_name, strerror(errno));
1183 			goto failed;
1184 		}
1185 	}
1186 
1187 	if (ifname != NULL)
1188 		*ifname = xstrdup(ifr.ifr_name);
1189 
1190 	close(sock);
1191 	return fd;
1192 
1193  failed:
1194 	if (fd >= 0)
1195 		close(fd);
1196 	if (sock >= 0)
1197 		close(sock);
1198 	return -1;
1199 #else
1200 	error("Tunnel interfaces are not supported on this platform");
1201 	return (-1);
1202 #endif
1203 }
1204 
1205 void
1206 sanitise_stdfd(void)
1207 {
1208 	int nullfd, dupfd;
1209 
1210 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1211 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
1212 		    strerror(errno));
1213 		exit(1);
1214 	}
1215 	while (++dupfd <= STDERR_FILENO) {
1216 		/* Only populate closed fds. */
1217 		if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
1218 			if (dup2(nullfd, dupfd) == -1) {
1219 				fprintf(stderr, "dup2: %s\n", strerror(errno));
1220 				exit(1);
1221 			}
1222 		}
1223 	}
1224 	if (nullfd > STDERR_FILENO)
1225 		close(nullfd);
1226 }
1227 
1228 char *
1229 tohex(const void *vp, size_t l)
1230 {
1231 	const u_char *p = (const u_char *)vp;
1232 	char b[3], *r;
1233 	size_t i, hl;
1234 
1235 	if (l > 65536)
1236 		return xstrdup("tohex: length > 65536");
1237 
1238 	hl = l * 2 + 1;
1239 	r = xcalloc(1, hl);
1240 	for (i = 0; i < l; i++) {
1241 		snprintf(b, sizeof(b), "%02x", p[i]);
1242 		strlcat(r, b, hl);
1243 	}
1244 	return (r);
1245 }
1246 
1247 /*
1248  * Extend string *sp by the specified format. If *sp is not NULL (or empty),
1249  * then the separator 'sep' will be prepended before the formatted arguments.
1250  * Extended strings are heap allocated.
1251  */
1252 void
1253 xextendf(char **sp, const char *sep, const char *fmt, ...)
1254 {
1255 	va_list ap;
1256 	char *tmp1, *tmp2;
1257 
1258 	va_start(ap, fmt);
1259 	xvasprintf(&tmp1, fmt, ap);
1260 	va_end(ap);
1261 
1262 	if (*sp == NULL || **sp == '\0') {
1263 		free(*sp);
1264 		*sp = tmp1;
1265 		return;
1266 	}
1267 	xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1);
1268 	free(tmp1);
1269 	free(*sp);
1270 	*sp = tmp2;
1271 }
1272 
1273 
1274 u_int64_t
1275 get_u64(const void *vp)
1276 {
1277 	const u_char *p = (const u_char *)vp;
1278 	u_int64_t v;
1279 
1280 	v  = (u_int64_t)p[0] << 56;
1281 	v |= (u_int64_t)p[1] << 48;
1282 	v |= (u_int64_t)p[2] << 40;
1283 	v |= (u_int64_t)p[3] << 32;
1284 	v |= (u_int64_t)p[4] << 24;
1285 	v |= (u_int64_t)p[5] << 16;
1286 	v |= (u_int64_t)p[6] << 8;
1287 	v |= (u_int64_t)p[7];
1288 
1289 	return (v);
1290 }
1291 
1292 u_int32_t
1293 get_u32(const void *vp)
1294 {
1295 	const u_char *p = (const u_char *)vp;
1296 	u_int32_t v;
1297 
1298 	v  = (u_int32_t)p[0] << 24;
1299 	v |= (u_int32_t)p[1] << 16;
1300 	v |= (u_int32_t)p[2] << 8;
1301 	v |= (u_int32_t)p[3];
1302 
1303 	return (v);
1304 }
1305 
1306 u_int32_t
1307 get_u32_le(const void *vp)
1308 {
1309 	const u_char *p = (const u_char *)vp;
1310 	u_int32_t v;
1311 
1312 	v  = (u_int32_t)p[0];
1313 	v |= (u_int32_t)p[1] << 8;
1314 	v |= (u_int32_t)p[2] << 16;
1315 	v |= (u_int32_t)p[3] << 24;
1316 
1317 	return (v);
1318 }
1319 
1320 u_int16_t
1321 get_u16(const void *vp)
1322 {
1323 	const u_char *p = (const u_char *)vp;
1324 	u_int16_t v;
1325 
1326 	v  = (u_int16_t)p[0] << 8;
1327 	v |= (u_int16_t)p[1];
1328 
1329 	return (v);
1330 }
1331 
1332 void
1333 put_u64(void *vp, u_int64_t v)
1334 {
1335 	u_char *p = (u_char *)vp;
1336 
1337 	p[0] = (u_char)(v >> 56) & 0xff;
1338 	p[1] = (u_char)(v >> 48) & 0xff;
1339 	p[2] = (u_char)(v >> 40) & 0xff;
1340 	p[3] = (u_char)(v >> 32) & 0xff;
1341 	p[4] = (u_char)(v >> 24) & 0xff;
1342 	p[5] = (u_char)(v >> 16) & 0xff;
1343 	p[6] = (u_char)(v >> 8) & 0xff;
1344 	p[7] = (u_char)v & 0xff;
1345 }
1346 
1347 void
1348 put_u32(void *vp, u_int32_t v)
1349 {
1350 	u_char *p = (u_char *)vp;
1351 
1352 	p[0] = (u_char)(v >> 24) & 0xff;
1353 	p[1] = (u_char)(v >> 16) & 0xff;
1354 	p[2] = (u_char)(v >> 8) & 0xff;
1355 	p[3] = (u_char)v & 0xff;
1356 }
1357 
1358 void
1359 put_u32_le(void *vp, u_int32_t v)
1360 {
1361 	u_char *p = (u_char *)vp;
1362 
1363 	p[0] = (u_char)v & 0xff;
1364 	p[1] = (u_char)(v >> 8) & 0xff;
1365 	p[2] = (u_char)(v >> 16) & 0xff;
1366 	p[3] = (u_char)(v >> 24) & 0xff;
1367 }
1368 
1369 void
1370 put_u16(void *vp, u_int16_t v)
1371 {
1372 	u_char *p = (u_char *)vp;
1373 
1374 	p[0] = (u_char)(v >> 8) & 0xff;
1375 	p[1] = (u_char)v & 0xff;
1376 }
1377 
1378 void
1379 ms_subtract_diff(struct timeval *start, int *ms)
1380 {
1381 	struct timeval diff, finish;
1382 
1383 	monotime_tv(&finish);
1384 	timersub(&finish, start, &diff);
1385 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
1386 }
1387 
1388 void
1389 ms_to_timeval(struct timeval *tv, int ms)
1390 {
1391 	if (ms < 0)
1392 		ms = 0;
1393 	tv->tv_sec = ms / 1000;
1394 	tv->tv_usec = (ms % 1000) * 1000;
1395 }
1396 
1397 void
1398 monotime_ts(struct timespec *ts)
1399 {
1400 	struct timeval tv;
1401 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \
1402     defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME))
1403 	static int gettime_failed = 0;
1404 
1405 	if (!gettime_failed) {
1406 # ifdef CLOCK_BOOTTIME
1407 		if (clock_gettime(CLOCK_BOOTTIME, ts) == 0)
1408 			return;
1409 # endif /* CLOCK_BOOTTIME */
1410 # ifdef CLOCK_MONOTONIC
1411 		if (clock_gettime(CLOCK_MONOTONIC, ts) == 0)
1412 			return;
1413 # endif /* CLOCK_MONOTONIC */
1414 # ifdef CLOCK_REALTIME
1415 		/* Not monotonic, but we're almost out of options here. */
1416 		if (clock_gettime(CLOCK_REALTIME, ts) == 0)
1417 			return;
1418 # endif /* CLOCK_REALTIME */
1419 		debug3("clock_gettime: %s", strerror(errno));
1420 		gettime_failed = 1;
1421 	}
1422 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */
1423 	gettimeofday(&tv, NULL);
1424 	ts->tv_sec = tv.tv_sec;
1425 	ts->tv_nsec = (long)tv.tv_usec * 1000;
1426 }
1427 
1428 void
1429 monotime_tv(struct timeval *tv)
1430 {
1431 	struct timespec ts;
1432 
1433 	monotime_ts(&ts);
1434 	tv->tv_sec = ts.tv_sec;
1435 	tv->tv_usec = ts.tv_nsec / 1000;
1436 }
1437 
1438 time_t
1439 monotime(void)
1440 {
1441 	struct timespec ts;
1442 
1443 	monotime_ts(&ts);
1444 	return ts.tv_sec;
1445 }
1446 
1447 double
1448 monotime_double(void)
1449 {
1450 	struct timespec ts;
1451 
1452 	monotime_ts(&ts);
1453 	return ts.tv_sec + ((double)ts.tv_nsec / 1000000000);
1454 }
1455 
1456 void
1457 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
1458 {
1459 	bw->buflen = buflen;
1460 	bw->rate = kbps;
1461 	bw->thresh = buflen;
1462 	bw->lamt = 0;
1463 	timerclear(&bw->bwstart);
1464 	timerclear(&bw->bwend);
1465 }
1466 
1467 /* Callback from read/write loop to insert bandwidth-limiting delays */
1468 void
1469 bandwidth_limit(struct bwlimit *bw, size_t read_len)
1470 {
1471 	u_int64_t waitlen;
1472 	struct timespec ts, rm;
1473 
1474 	bw->lamt += read_len;
1475 	if (!timerisset(&bw->bwstart)) {
1476 		monotime_tv(&bw->bwstart);
1477 		return;
1478 	}
1479 	if (bw->lamt < bw->thresh)
1480 		return;
1481 
1482 	monotime_tv(&bw->bwend);
1483 	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
1484 	if (!timerisset(&bw->bwend))
1485 		return;
1486 
1487 	bw->lamt *= 8;
1488 	waitlen = (double)1000000L * bw->lamt / bw->rate;
1489 
1490 	bw->bwstart.tv_sec = waitlen / 1000000L;
1491 	bw->bwstart.tv_usec = waitlen % 1000000L;
1492 
1493 	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
1494 		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
1495 
1496 		/* Adjust the wait time */
1497 		if (bw->bwend.tv_sec) {
1498 			bw->thresh /= 2;
1499 			if (bw->thresh < bw->buflen / 4)
1500 				bw->thresh = bw->buflen / 4;
1501 		} else if (bw->bwend.tv_usec < 10000) {
1502 			bw->thresh *= 2;
1503 			if (bw->thresh > bw->buflen * 8)
1504 				bw->thresh = bw->buflen * 8;
1505 		}
1506 
1507 		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
1508 		while (nanosleep(&ts, &rm) == -1) {
1509 			if (errno != EINTR)
1510 				break;
1511 			ts = rm;
1512 		}
1513 	}
1514 
1515 	bw->lamt = 0;
1516 	monotime_tv(&bw->bwstart);
1517 }
1518 
1519 /* Make a template filename for mk[sd]temp() */
1520 void
1521 mktemp_proto(char *s, size_t len)
1522 {
1523 	const char *tmpdir;
1524 	int r;
1525 
1526 	if ((tmpdir = getenv("TMPDIR")) != NULL) {
1527 		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
1528 		if (r > 0 && (size_t)r < len)
1529 			return;
1530 	}
1531 	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
1532 	if (r < 0 || (size_t)r >= len)
1533 		fatal("%s: template string too short", __func__);
1534 }
1535 
1536 static const struct {
1537 	const char *name;
1538 	int value;
1539 } ipqos[] = {
1540 	{ "none", INT_MAX },		/* can't use 0 here; that's CS0 */
1541 	{ "af11", IPTOS_DSCP_AF11 },
1542 	{ "af12", IPTOS_DSCP_AF12 },
1543 	{ "af13", IPTOS_DSCP_AF13 },
1544 	{ "af21", IPTOS_DSCP_AF21 },
1545 	{ "af22", IPTOS_DSCP_AF22 },
1546 	{ "af23", IPTOS_DSCP_AF23 },
1547 	{ "af31", IPTOS_DSCP_AF31 },
1548 	{ "af32", IPTOS_DSCP_AF32 },
1549 	{ "af33", IPTOS_DSCP_AF33 },
1550 	{ "af41", IPTOS_DSCP_AF41 },
1551 	{ "af42", IPTOS_DSCP_AF42 },
1552 	{ "af43", IPTOS_DSCP_AF43 },
1553 	{ "cs0", IPTOS_DSCP_CS0 },
1554 	{ "cs1", IPTOS_DSCP_CS1 },
1555 	{ "cs2", IPTOS_DSCP_CS2 },
1556 	{ "cs3", IPTOS_DSCP_CS3 },
1557 	{ "cs4", IPTOS_DSCP_CS4 },
1558 	{ "cs5", IPTOS_DSCP_CS5 },
1559 	{ "cs6", IPTOS_DSCP_CS6 },
1560 	{ "cs7", IPTOS_DSCP_CS7 },
1561 	{ "ef", IPTOS_DSCP_EF },
1562 	{ "le", IPTOS_DSCP_LE },
1563 	{ "lowdelay", IPTOS_LOWDELAY },
1564 	{ "throughput", IPTOS_THROUGHPUT },
1565 	{ "reliability", IPTOS_RELIABILITY },
1566 	{ NULL, -1 }
1567 };
1568 
1569 int
1570 parse_ipqos(const char *cp)
1571 {
1572 	u_int i;
1573 	char *ep;
1574 	long val;
1575 
1576 	if (cp == NULL)
1577 		return -1;
1578 	for (i = 0; ipqos[i].name != NULL; i++) {
1579 		if (strcasecmp(cp, ipqos[i].name) == 0)
1580 			return ipqos[i].value;
1581 	}
1582 	/* Try parsing as an integer */
1583 	val = strtol(cp, &ep, 0);
1584 	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1585 		return -1;
1586 	return val;
1587 }
1588 
1589 const char *
1590 iptos2str(int iptos)
1591 {
1592 	int i;
1593 	static char iptos_str[sizeof "0xff"];
1594 
1595 	for (i = 0; ipqos[i].name != NULL; i++) {
1596 		if (ipqos[i].value == iptos)
1597 			return ipqos[i].name;
1598 	}
1599 	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1600 	return iptos_str;
1601 }
1602 
1603 void
1604 lowercase(char *s)
1605 {
1606 	for (; *s; s++)
1607 		*s = tolower((u_char)*s);
1608 }
1609 
1610 int
1611 unix_listener(const char *path, int backlog, int unlink_first)
1612 {
1613 	struct sockaddr_un sunaddr;
1614 	int saved_errno, sock;
1615 
1616 	memset(&sunaddr, 0, sizeof(sunaddr));
1617 	sunaddr.sun_family = AF_UNIX;
1618 	if (strlcpy(sunaddr.sun_path, path,
1619 	    sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1620 		error("%s: path \"%s\" too long for Unix domain socket",
1621 		    __func__, path);
1622 		errno = ENAMETOOLONG;
1623 		return -1;
1624 	}
1625 
1626 	sock = socket(PF_UNIX, SOCK_STREAM, 0);
1627 	if (sock == -1) {
1628 		saved_errno = errno;
1629 		error("%s: socket: %.100s", __func__, strerror(errno));
1630 		errno = saved_errno;
1631 		return -1;
1632 	}
1633 	if (unlink_first == 1) {
1634 		if (unlink(path) != 0 && errno != ENOENT)
1635 			error("unlink(%s): %.100s", path, strerror(errno));
1636 	}
1637 	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
1638 		saved_errno = errno;
1639 		error("%s: cannot bind to path %s: %s",
1640 		    __func__, path, strerror(errno));
1641 		close(sock);
1642 		errno = saved_errno;
1643 		return -1;
1644 	}
1645 	if (listen(sock, backlog) == -1) {
1646 		saved_errno = errno;
1647 		error("%s: cannot listen on path %s: %s",
1648 		    __func__, path, strerror(errno));
1649 		close(sock);
1650 		unlink(path);
1651 		errno = saved_errno;
1652 		return -1;
1653 	}
1654 	return sock;
1655 }
1656 
1657 void
1658 sock_set_v6only(int s)
1659 {
1660 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
1661 	int on = 1;
1662 
1663 	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1664 	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1665 		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1666 #endif
1667 }
1668 
1669 /*
1670  * Compares two strings that maybe be NULL. Returns non-zero if strings
1671  * are both NULL or are identical, returns zero otherwise.
1672  */
1673 static int
1674 strcmp_maybe_null(const char *a, const char *b)
1675 {
1676 	if ((a == NULL && b != NULL) || (a != NULL && b == NULL))
1677 		return 0;
1678 	if (a != NULL && strcmp(a, b) != 0)
1679 		return 0;
1680 	return 1;
1681 }
1682 
1683 /*
1684  * Compare two forwards, returning non-zero if they are identical or
1685  * zero otherwise.
1686  */
1687 int
1688 forward_equals(const struct Forward *a, const struct Forward *b)
1689 {
1690 	if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0)
1691 		return 0;
1692 	if (a->listen_port != b->listen_port)
1693 		return 0;
1694 	if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0)
1695 		return 0;
1696 	if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0)
1697 		return 0;
1698 	if (a->connect_port != b->connect_port)
1699 		return 0;
1700 	if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0)
1701 		return 0;
1702 	/* allocated_port and handle are not checked */
1703 	return 1;
1704 }
1705 
1706 /* returns 1 if process is already daemonized, 0 otherwise */
1707 int
1708 daemonized(void)
1709 {
1710 	int fd;
1711 
1712 	if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
1713 		close(fd);
1714 		return 0;	/* have controlling terminal */
1715 	}
1716 	if (getppid() != 1)
1717 		return 0;	/* parent is not init */
1718 	if (getsid(0) != getpid())
1719 		return 0;	/* not session leader */
1720 	debug3("already daemonized");
1721 	return 1;
1722 }
1723 
1724 
1725 /*
1726  * Splits 's' into an argument vector. Handles quoted string and basic
1727  * escape characters (\\, \", \'). Caller must free the argument vector
1728  * and its members.
1729  */
1730 int
1731 argv_split(const char *s, int *argcp, char ***argvp)
1732 {
1733 	int r = SSH_ERR_INTERNAL_ERROR;
1734 	int argc = 0, quote, i, j;
1735 	char *arg, **argv = xcalloc(1, sizeof(*argv));
1736 
1737 	*argvp = NULL;
1738 	*argcp = 0;
1739 
1740 	for (i = 0; s[i] != '\0'; i++) {
1741 		/* Skip leading whitespace */
1742 		if (s[i] == ' ' || s[i] == '\t')
1743 			continue;
1744 
1745 		/* Start of a token */
1746 		quote = 0;
1747 		if (s[i] == '\\' &&
1748 		    (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\'))
1749 			i++;
1750 		else if (s[i] == '\'' || s[i] == '"')
1751 			quote = s[i++];
1752 
1753 		argv = xreallocarray(argv, (argc + 2), sizeof(*argv));
1754 		arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1);
1755 		argv[argc] = NULL;
1756 
1757 		/* Copy the token in, removing escapes */
1758 		for (j = 0; s[i] != '\0'; i++) {
1759 			if (s[i] == '\\') {
1760 				if (s[i + 1] == '\'' ||
1761 				    s[i + 1] == '\"' ||
1762 				    s[i + 1] == '\\') {
1763 					i++; /* Skip '\' */
1764 					arg[j++] = s[i];
1765 				} else {
1766 					/* Unrecognised escape */
1767 					arg[j++] = s[i];
1768 				}
1769 			} else if (quote == 0 && (s[i] == ' ' || s[i] == '\t'))
1770 				break; /* done */
1771 			else if (quote != 0 && s[i] == quote)
1772 				break; /* done */
1773 			else
1774 				arg[j++] = s[i];
1775 		}
1776 		if (s[i] == '\0') {
1777 			if (quote != 0) {
1778 				/* Ran out of string looking for close quote */
1779 				r = SSH_ERR_INVALID_FORMAT;
1780 				goto out;
1781 			}
1782 			break;
1783 		}
1784 	}
1785 	/* Success */
1786 	*argcp = argc;
1787 	*argvp = argv;
1788 	argc = 0;
1789 	argv = NULL;
1790 	r = 0;
1791  out:
1792 	if (argc != 0 && argv != NULL) {
1793 		for (i = 0; i < argc; i++)
1794 			free(argv[i]);
1795 		free(argv);
1796 	}
1797 	return r;
1798 }
1799 
1800 /*
1801  * Reassemble an argument vector into a string, quoting and escaping as
1802  * necessary. Caller must free returned string.
1803  */
1804 char *
1805 argv_assemble(int argc, char **argv)
1806 {
1807 	int i, j, ws, r;
1808 	char c, *ret;
1809 	struct sshbuf *buf, *arg;
1810 
1811 	if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL)
1812 		fatal("%s: sshbuf_new failed", __func__);
1813 
1814 	for (i = 0; i < argc; i++) {
1815 		ws = 0;
1816 		sshbuf_reset(arg);
1817 		for (j = 0; argv[i][j] != '\0'; j++) {
1818 			r = 0;
1819 			c = argv[i][j];
1820 			switch (c) {
1821 			case ' ':
1822 			case '\t':
1823 				ws = 1;
1824 				r = sshbuf_put_u8(arg, c);
1825 				break;
1826 			case '\\':
1827 			case '\'':
1828 			case '"':
1829 				if ((r = sshbuf_put_u8(arg, '\\')) != 0)
1830 					break;
1831 				/* FALLTHROUGH */
1832 			default:
1833 				r = sshbuf_put_u8(arg, c);
1834 				break;
1835 			}
1836 			if (r != 0)
1837 				fatal("%s: sshbuf_put_u8: %s",
1838 				    __func__, ssh_err(r));
1839 		}
1840 		if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) ||
1841 		    (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) ||
1842 		    (r = sshbuf_putb(buf, arg)) != 0 ||
1843 		    (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0))
1844 			fatal("%s: buffer error: %s", __func__, ssh_err(r));
1845 	}
1846 	if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL)
1847 		fatal("%s: malloc failed", __func__);
1848 	memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf));
1849 	ret[sshbuf_len(buf)] = '\0';
1850 	sshbuf_free(buf);
1851 	sshbuf_free(arg);
1852 	return ret;
1853 }
1854 
1855 /* Returns 0 if pid exited cleanly, non-zero otherwise */
1856 int
1857 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)
1858 {
1859 	int status;
1860 
1861 	while (waitpid(pid, &status, 0) == -1) {
1862 		if (errno != EINTR) {
1863 			error("%s: waitpid: %s", tag, strerror(errno));
1864 			return -1;
1865 		}
1866 	}
1867 	if (WIFSIGNALED(status)) {
1868 		error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status));
1869 		return -1;
1870 	} else if (WEXITSTATUS(status) != 0) {
1871 		do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO,
1872 		    "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status));
1873 		return -1;
1874 	}
1875 	return 0;
1876 }
1877 
1878 /*
1879  * Check a given path for security. This is defined as all components
1880  * of the path to the file must be owned by either the owner of
1881  * of the file or root and no directories must be group or world writable.
1882  *
1883  * XXX Should any specific check be done for sym links ?
1884  *
1885  * Takes a file name, its stat information (preferably from fstat() to
1886  * avoid races), the uid of the expected owner, their home directory and an
1887  * error buffer plus max size as arguments.
1888  *
1889  * Returns 0 on success and -1 on failure
1890  */
1891 int
1892 safe_path(const char *name, struct stat *stp, const char *pw_dir,
1893     uid_t uid, char *err, size_t errlen)
1894 {
1895 	char buf[PATH_MAX], homedir[PATH_MAX];
1896 	char *cp;
1897 	int comparehome = 0;
1898 	struct stat st;
1899 
1900 	if (realpath(name, buf) == NULL) {
1901 		snprintf(err, errlen, "realpath %s failed: %s", name,
1902 		    strerror(errno));
1903 		return -1;
1904 	}
1905 	if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
1906 		comparehome = 1;
1907 
1908 	if (!S_ISREG(stp->st_mode)) {
1909 		snprintf(err, errlen, "%s is not a regular file", buf);
1910 		return -1;
1911 	}
1912 	if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) ||
1913 	    (stp->st_mode & 022) != 0) {
1914 		snprintf(err, errlen, "bad ownership or modes for file %s",
1915 		    buf);
1916 		return -1;
1917 	}
1918 
1919 	/* for each component of the canonical path, walking upwards */
1920 	for (;;) {
1921 		if ((cp = dirname(buf)) == NULL) {
1922 			snprintf(err, errlen, "dirname() failed");
1923 			return -1;
1924 		}
1925 		strlcpy(buf, cp, sizeof(buf));
1926 
1927 		if (stat(buf, &st) == -1 ||
1928 		    (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) ||
1929 		    (st.st_mode & 022) != 0) {
1930 			snprintf(err, errlen,
1931 			    "bad ownership or modes for directory %s", buf);
1932 			return -1;
1933 		}
1934 
1935 		/* If are past the homedir then we can stop */
1936 		if (comparehome && strcmp(homedir, buf) == 0)
1937 			break;
1938 
1939 		/*
1940 		 * dirname should always complete with a "/" path,
1941 		 * but we can be paranoid and check for "." too
1942 		 */
1943 		if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
1944 			break;
1945 	}
1946 	return 0;
1947 }
1948 
1949 /*
1950  * Version of safe_path() that accepts an open file descriptor to
1951  * avoid races.
1952  *
1953  * Returns 0 on success and -1 on failure
1954  */
1955 int
1956 safe_path_fd(int fd, const char *file, struct passwd *pw,
1957     char *err, size_t errlen)
1958 {
1959 	struct stat st;
1960 
1961 	/* check the open file to avoid races */
1962 	if (fstat(fd, &st) == -1) {
1963 		snprintf(err, errlen, "cannot stat file %s: %s",
1964 		    file, strerror(errno));
1965 		return -1;
1966 	}
1967 	return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
1968 }
1969 
1970 /*
1971  * Sets the value of the given variable in the environment.  If the variable
1972  * already exists, its value is overridden.
1973  */
1974 void
1975 child_set_env(char ***envp, u_int *envsizep, const char *name,
1976 	const char *value)
1977 {
1978 	char **env;
1979 	u_int envsize;
1980 	u_int i, namelen;
1981 
1982 	if (strchr(name, '=') != NULL) {
1983 		error("Invalid environment variable \"%.100s\"", name);
1984 		return;
1985 	}
1986 
1987 	/*
1988 	 * If we're passed an uninitialized list, allocate a single null
1989 	 * entry before continuing.
1990 	 */
1991 	if (*envp == NULL && *envsizep == 0) {
1992 		*envp = xmalloc(sizeof(char *));
1993 		*envp[0] = NULL;
1994 		*envsizep = 1;
1995 	}
1996 
1997 	/*
1998 	 * Find the slot where the value should be stored.  If the variable
1999 	 * already exists, we reuse the slot; otherwise we append a new slot
2000 	 * at the end of the array, expanding if necessary.
2001 	 */
2002 	env = *envp;
2003 	namelen = strlen(name);
2004 	for (i = 0; env[i]; i++)
2005 		if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
2006 			break;
2007 	if (env[i]) {
2008 		/* Reuse the slot. */
2009 		free(env[i]);
2010 	} else {
2011 		/* New variable.  Expand if necessary. */
2012 		envsize = *envsizep;
2013 		if (i >= envsize - 1) {
2014 			if (envsize >= 1000)
2015 				fatal("child_set_env: too many env vars");
2016 			envsize += 50;
2017 			env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
2018 			*envsizep = envsize;
2019 		}
2020 		/* Need to set the NULL pointer at end of array beyond the new slot. */
2021 		env[i + 1] = NULL;
2022 	}
2023 
2024 	/* Allocate space and format the variable in the appropriate slot. */
2025 	/* XXX xasprintf */
2026 	env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
2027 	snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
2028 }
2029 
2030 /*
2031  * Check and optionally lowercase a domain name, also removes trailing '.'
2032  * Returns 1 on success and 0 on failure, storing an error message in errstr.
2033  */
2034 int
2035 valid_domain(char *name, int makelower, const char **errstr)
2036 {
2037 	size_t i, l = strlen(name);
2038 	u_char c, last = '\0';
2039 	static char errbuf[256];
2040 
2041 	if (l == 0) {
2042 		strlcpy(errbuf, "empty domain name", sizeof(errbuf));
2043 		goto bad;
2044 	}
2045 	if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) {
2046 		snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" "
2047 		    "starts with invalid character", name);
2048 		goto bad;
2049 	}
2050 	for (i = 0; i < l; i++) {
2051 		c = tolower((u_char)name[i]);
2052 		if (makelower)
2053 			name[i] = (char)c;
2054 		if (last == '.' && c == '.') {
2055 			snprintf(errbuf, sizeof(errbuf), "domain name "
2056 			    "\"%.100s\" contains consecutive separators", name);
2057 			goto bad;
2058 		}
2059 		if (c != '.' && c != '-' && !isalnum(c) &&
2060 		    c != '_') /* technically invalid, but common */ {
2061 			snprintf(errbuf, sizeof(errbuf), "domain name "
2062 			    "\"%.100s\" contains invalid characters", name);
2063 			goto bad;
2064 		}
2065 		last = c;
2066 	}
2067 	if (name[l - 1] == '.')
2068 		name[l - 1] = '\0';
2069 	if (errstr != NULL)
2070 		*errstr = NULL;
2071 	return 1;
2072 bad:
2073 	if (errstr != NULL)
2074 		*errstr = errbuf;
2075 	return 0;
2076 }
2077 
2078 /*
2079  * Verify that a environment variable name (not including initial '$') is
2080  * valid; consisting of one or more alphanumeric or underscore characters only.
2081  * Returns 1 on valid, 0 otherwise.
2082  */
2083 int
2084 valid_env_name(const char *name)
2085 {
2086 	const char *cp;
2087 
2088 	if (name[0] == '\0')
2089 		return 0;
2090 	for (cp = name; *cp != '\0'; cp++) {
2091 		if (!isalnum((u_char)*cp) && *cp != '_')
2092 			return 0;
2093 	}
2094 	return 1;
2095 }
2096 
2097 const char *
2098 atoi_err(const char *nptr, int *val)
2099 {
2100 	const char *errstr = NULL;
2101 	long long num;
2102 
2103 	if (nptr == NULL || *nptr == '\0')
2104 		return "missing";
2105 	num = strtonum(nptr, 0, INT_MAX, &errstr);
2106 	if (errstr == NULL)
2107 		*val = (int)num;
2108 	return errstr;
2109 }
2110 
2111 int
2112 parse_absolute_time(const char *s, uint64_t *tp)
2113 {
2114 	struct tm tm;
2115 	time_t tt;
2116 	char buf[32], *fmt;
2117 
2118 	*tp = 0;
2119 
2120 	/*
2121 	 * POSIX strptime says "The application shall ensure that there
2122 	 * is white-space or other non-alphanumeric characters between
2123 	 * any two conversion specifications" so arrange things this way.
2124 	 */
2125 	switch (strlen(s)) {
2126 	case 8: /* YYYYMMDD */
2127 		fmt = "%Y-%m-%d";
2128 		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
2129 		break;
2130 	case 12: /* YYYYMMDDHHMM */
2131 		fmt = "%Y-%m-%dT%H:%M";
2132 		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s",
2133 		    s, s + 4, s + 6, s + 8, s + 10);
2134 		break;
2135 	case 14: /* YYYYMMDDHHMMSS */
2136 		fmt = "%Y-%m-%dT%H:%M:%S";
2137 		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
2138 		    s, s + 4, s + 6, s + 8, s + 10, s + 12);
2139 		break;
2140 	default:
2141 		return SSH_ERR_INVALID_FORMAT;
2142 	}
2143 
2144 	memset(&tm, 0, sizeof(tm));
2145 	if (strptime(buf, fmt, &tm) == NULL)
2146 		return SSH_ERR_INVALID_FORMAT;
2147 	if ((tt = mktime(&tm)) < 0)
2148 		return SSH_ERR_INVALID_FORMAT;
2149 	/* success */
2150 	*tp = (uint64_t)tt;
2151 	return 0;
2152 }
2153 
2154 void
2155 format_absolute_time(uint64_t t, char *buf, size_t len)
2156 {
2157 	time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */
2158 	struct tm tm;
2159 
2160 	localtime_r(&tt, &tm);
2161 	strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
2162 }
2163 
2164 /* check if path is absolute */
2165 int
2166 path_absolute(const char *path)
2167 {
2168 	return (*path == '/') ? 1 : 0;
2169 }
2170 
2171 void
2172 skip_space(char **cpp)
2173 {
2174 	char *cp;
2175 
2176 	for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
2177 		;
2178 	*cpp = cp;
2179 }
2180 
2181 /* authorized_key-style options parsing helpers */
2182 
2183 /*
2184  * Match flag 'opt' in *optsp, and if allow_negate is set then also match
2185  * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0
2186  * if negated option matches.
2187  * If the option or negated option matches, then *optsp is updated to
2188  * point to the first character after the option.
2189  */
2190 int
2191 opt_flag(const char *opt, int allow_negate, const char **optsp)
2192 {
2193 	size_t opt_len = strlen(opt);
2194 	const char *opts = *optsp;
2195 	int negate = 0;
2196 
2197 	if (allow_negate && strncasecmp(opts, "no-", 3) == 0) {
2198 		opts += 3;
2199 		negate = 1;
2200 	}
2201 	if (strncasecmp(opts, opt, opt_len) == 0) {
2202 		*optsp = opts + opt_len;
2203 		return negate ? 0 : 1;
2204 	}
2205 	return -1;
2206 }
2207 
2208 char *
2209 opt_dequote(const char **sp, const char **errstrp)
2210 {
2211 	const char *s = *sp;
2212 	char *ret;
2213 	size_t i;
2214 
2215 	*errstrp = NULL;
2216 	if (*s != '"') {
2217 		*errstrp = "missing start quote";
2218 		return NULL;
2219 	}
2220 	s++;
2221 	if ((ret = malloc(strlen((s)) + 1)) == NULL) {
2222 		*errstrp = "memory allocation failed";
2223 		return NULL;
2224 	}
2225 	for (i = 0; *s != '\0' && *s != '"';) {
2226 		if (s[0] == '\\' && s[1] == '"')
2227 			s++;
2228 		ret[i++] = *s++;
2229 	}
2230 	if (*s == '\0') {
2231 		*errstrp = "missing end quote";
2232 		free(ret);
2233 		return NULL;
2234 	}
2235 	ret[i] = '\0';
2236 	s++;
2237 	*sp = s;
2238 	return ret;
2239 }
2240 
2241 int
2242 opt_match(const char **opts, const char *term)
2243 {
2244 	if (strncasecmp((*opts), term, strlen(term)) == 0 &&
2245 	    (*opts)[strlen(term)] == '=') {
2246 		*opts += strlen(term) + 1;
2247 		return 1;
2248 	}
2249 	return 0;
2250 }
2251 
2252 sshsig_t
2253 ssh_signal(int signum, sshsig_t handler)
2254 {
2255 	struct sigaction sa, osa;
2256 
2257 	/* mask all other signals while in handler */
2258 	bzero(&sa, sizeof(sa));
2259 	sa.sa_handler = handler;
2260 	sigfillset(&sa.sa_mask);
2261 	if (signum != SIGALRM)
2262 		sa.sa_flags = SA_RESTART;
2263 	if (sigaction(signum, &sa, &osa) == -1) {
2264 		debug3("sigaction(%s): %s", strsignal(signum), strerror(errno));
2265 		return SIG_ERR;
2266 	}
2267 	return osa.sa_handler;
2268 }
2269