1/* $OpenBSD: misc.c,v 1.133 2018/10/05 14:26:09 naddy 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#include <signal.h>
42#include <stdarg.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46#include <time.h>
47#include <unistd.h>
48
49#include <netinet/in.h>
50#include <netinet/in_systm.h>
51#include <netinet/ip.h>
52#include <netinet/tcp.h>
53#include <arpa/inet.h>
54
55#include <ctype.h>
56#include <errno.h>
57#include <fcntl.h>
58#include <netdb.h>
59#ifdef HAVE_PATHS_H
60# include <paths.h>
61#include <pwd.h>
62#endif
63#ifdef SSH_TUN_OPENBSD
64#include <net/if.h>
65#endif
66
67#include "xmalloc.h"
68#include "misc.h"
69#include "log.h"
70#include "ssh.h"
71#include "sshbuf.h"
72#include "ssherr.h"
73#include "platform.h"
74
75/* remove newline at end of string */
76char *
77chop(char *s)
78{
79	char *t = s;
80	while (*t) {
81		if (*t == '\n' || *t == '\r') {
82			*t = '\0';
83			return s;
84		}
85		t++;
86	}
87	return s;
88
89}
90
91/* set/unset filedescriptor to non-blocking */
92int
93set_nonblock(int fd)
94{
95	int val;
96
97	val = fcntl(fd, F_GETFL);
98	if (val < 0) {
99		error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
100		return (-1);
101	}
102	if (val & O_NONBLOCK) {
103		debug3("fd %d is O_NONBLOCK", fd);
104		return (0);
105	}
106	debug2("fd %d setting O_NONBLOCK", fd);
107	val |= O_NONBLOCK;
108	if (fcntl(fd, F_SETFL, val) == -1) {
109		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
110		    strerror(errno));
111		return (-1);
112	}
113	return (0);
114}
115
116int
117unset_nonblock(int fd)
118{
119	int val;
120
121	val = fcntl(fd, F_GETFL);
122	if (val < 0) {
123		error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
124		return (-1);
125	}
126	if (!(val & O_NONBLOCK)) {
127		debug3("fd %d is not O_NONBLOCK", fd);
128		return (0);
129	}
130	debug("fd %d clearing O_NONBLOCK", fd);
131	val &= ~O_NONBLOCK;
132	if (fcntl(fd, F_SETFL, val) == -1) {
133		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
134		    fd, strerror(errno));
135		return (-1);
136	}
137	return (0);
138}
139
140const char *
141ssh_gai_strerror(int gaierr)
142{
143	if (gaierr == EAI_SYSTEM && errno != 0)
144		return strerror(errno);
145	return gai_strerror(gaierr);
146}
147
148/* disable nagle on socket */
149void
150set_nodelay(int fd)
151{
152	int opt;
153	socklen_t optlen;
154
155	optlen = sizeof opt;
156	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
157		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
158		return;
159	}
160	if (opt == 1) {
161		debug2("fd %d is TCP_NODELAY", fd);
162		return;
163	}
164	opt = 1;
165	debug2("fd %d setting TCP_NODELAY", fd);
166	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
167		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
168}
169
170/* Allow local port reuse in TIME_WAIT */
171int
172set_reuseaddr(int fd)
173{
174	int on = 1;
175
176	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
177		error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
178		return -1;
179	}
180	return 0;
181}
182
183/* Get/set routing domain */
184char *
185get_rdomain(int fd)
186{
187#if defined(HAVE_SYS_GET_RDOMAIN)
188	return sys_get_rdomain(fd);
189#elif defined(__OpenBSD__)
190	int rtable;
191	char *ret;
192	socklen_t len = sizeof(rtable);
193
194	if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) {
195		error("Failed to get routing domain for fd %d: %s",
196		    fd, strerror(errno));
197		return NULL;
198	}
199	xasprintf(&ret, "%d", rtable);
200	return ret;
201#else /* defined(__OpenBSD__) */
202	return NULL;
203#endif
204}
205
206int
207set_rdomain(int fd, const char *name)
208{
209#if defined(HAVE_SYS_SET_RDOMAIN)
210	return sys_set_rdomain(fd, name);
211#elif defined(__OpenBSD__)
212	int rtable;
213	const char *errstr;
214
215	if (name == NULL)
216		return 0; /* default table */
217
218	rtable = (int)strtonum(name, 0, 255, &errstr);
219	if (errstr != NULL) {
220		/* Shouldn't happen */
221		error("Invalid routing domain \"%s\": %s", name, errstr);
222		return -1;
223	}
224	if (setsockopt(fd, SOL_SOCKET, SO_RTABLE,
225	    &rtable, sizeof(rtable)) == -1) {
226		error("Failed to set routing domain %d on fd %d: %s",
227		    rtable, fd, strerror(errno));
228		return -1;
229	}
230	return 0;
231#else /* defined(__OpenBSD__) */
232	error("Setting routing domain is not supported on this platform");
233	return -1;
234#endif
235}
236
237/* Characters considered whitespace in strsep calls. */
238#define WHITESPACE " \t\r\n"
239#define QUOTE	"\""
240
241/* return next token in configuration line */
242static char *
243strdelim_internal(char **s, int split_equals)
244{
245	char *old;
246	int wspace = 0;
247
248	if (*s == NULL)
249		return NULL;
250
251	old = *s;
252
253	*s = strpbrk(*s,
254	    split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE);
255	if (*s == NULL)
256		return (old);
257
258	if (*s[0] == '\"') {
259		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
260		/* Find matching quote */
261		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
262			return (NULL);		/* no matching quote */
263		} else {
264			*s[0] = '\0';
265			*s += strspn(*s + 1, WHITESPACE) + 1;
266			return (old);
267		}
268	}
269
270	/* Allow only one '=' to be skipped */
271	if (split_equals && *s[0] == '=')
272		wspace = 1;
273	*s[0] = '\0';
274
275	/* Skip any extra whitespace after first token */
276	*s += strspn(*s + 1, WHITESPACE) + 1;
277	if (split_equals && *s[0] == '=' && !wspace)
278		*s += strspn(*s + 1, WHITESPACE) + 1;
279
280	return (old);
281}
282
283/*
284 * Return next token in configuration line; splts on whitespace or a
285 * single '=' character.
286 */
287char *
288strdelim(char **s)
289{
290	return strdelim_internal(s, 1);
291}
292
293/*
294 * Return next token in configuration line; splts on whitespace only.
295 */
296char *
297strdelimw(char **s)
298{
299	return strdelim_internal(s, 0);
300}
301
302struct passwd *
303pwcopy(struct passwd *pw)
304{
305	struct passwd *copy = xcalloc(1, sizeof(*copy));
306
307	copy->pw_name = xstrdup(pw->pw_name);
308	copy->pw_passwd = xstrdup(pw->pw_passwd);
309#ifdef HAVE_STRUCT_PASSWD_PW_GECOS
310	copy->pw_gecos = xstrdup(pw->pw_gecos);
311#endif
312	copy->pw_uid = pw->pw_uid;
313	copy->pw_gid = pw->pw_gid;
314#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
315	copy->pw_expire = pw->pw_expire;
316#endif
317#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
318	copy->pw_change = pw->pw_change;
319#endif
320#ifdef HAVE_STRUCT_PASSWD_PW_CLASS
321	copy->pw_class = xstrdup(pw->pw_class);
322#endif
323	copy->pw_dir = xstrdup(pw->pw_dir);
324	copy->pw_shell = xstrdup(pw->pw_shell);
325	return copy;
326}
327
328/*
329 * Convert ASCII string to TCP/IP port number.
330 * Port must be >=0 and <=65535.
331 * Return -1 if invalid.
332 */
333int
334a2port(const char *s)
335{
336	struct servent *se;
337	long long port;
338	const char *errstr;
339
340	port = strtonum(s, 0, 65535, &errstr);
341	if (errstr == NULL)
342		return (int)port;
343	if ((se = getservbyname(s, "tcp")) != NULL)
344		return ntohs(se->s_port);
345	return -1;
346}
347
348int
349a2tun(const char *s, int *remote)
350{
351	const char *errstr = NULL;
352	char *sp, *ep;
353	int tun;
354
355	if (remote != NULL) {
356		*remote = SSH_TUNID_ANY;
357		sp = xstrdup(s);
358		if ((ep = strchr(sp, ':')) == NULL) {
359			free(sp);
360			return (a2tun(s, NULL));
361		}
362		ep[0] = '\0'; ep++;
363		*remote = a2tun(ep, NULL);
364		tun = a2tun(sp, NULL);
365		free(sp);
366		return (*remote == SSH_TUNID_ERR ? *remote : tun);
367	}
368
369	if (strcasecmp(s, "any") == 0)
370		return (SSH_TUNID_ANY);
371
372	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
373	if (errstr != NULL)
374		return (SSH_TUNID_ERR);
375
376	return (tun);
377}
378
379#define SECONDS		1
380#define MINUTES		(SECONDS * 60)
381#define HOURS		(MINUTES * 60)
382#define DAYS		(HOURS * 24)
383#define WEEKS		(DAYS * 7)
384
385/*
386 * Convert a time string into seconds; format is
387 * a sequence of:
388 *      time[qualifier]
389 *
390 * Valid time qualifiers are:
391 *      <none>  seconds
392 *      s|S     seconds
393 *      m|M     minutes
394 *      h|H     hours
395 *      d|D     days
396 *      w|W     weeks
397 *
398 * Examples:
399 *      90m     90 minutes
400 *      1h30m   90 minutes
401 *      2d      2 days
402 *      1w      1 week
403 *
404 * Return -1 if time string is invalid.
405 */
406long
407convtime(const char *s)
408{
409	long total, secs, multiplier = 1;
410	const char *p;
411	char *endp;
412
413	errno = 0;
414	total = 0;
415	p = s;
416
417	if (p == NULL || *p == '\0')
418		return -1;
419
420	while (*p) {
421		secs = strtol(p, &endp, 10);
422		if (p == endp ||
423		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
424		    secs < 0)
425			return -1;
426
427		switch (*endp++) {
428		case '\0':
429			endp--;
430			break;
431		case 's':
432		case 'S':
433			break;
434		case 'm':
435		case 'M':
436			multiplier = MINUTES;
437			break;
438		case 'h':
439		case 'H':
440			multiplier = HOURS;
441			break;
442		case 'd':
443		case 'D':
444			multiplier = DAYS;
445			break;
446		case 'w':
447		case 'W':
448			multiplier = WEEKS;
449			break;
450		default:
451			return -1;
452		}
453		if (secs >= LONG_MAX / multiplier)
454			return -1;
455		secs *= multiplier;
456		if  (total >= LONG_MAX - secs)
457			return -1;
458		total += secs;
459		if (total < 0)
460			return -1;
461		p = endp;
462	}
463
464	return total;
465}
466
467/*
468 * Returns a standardized host+port identifier string.
469 * Caller must free returned string.
470 */
471char *
472put_host_port(const char *host, u_short port)
473{
474	char *hoststr;
475
476	if (port == 0 || port == SSH_DEFAULT_PORT)
477		return(xstrdup(host));
478	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
479		fatal("put_host_port: asprintf: %s", strerror(errno));
480	debug3("put_host_port: %s", hoststr);
481	return hoststr;
482}
483
484/*
485 * Search for next delimiter between hostnames/addresses and ports.
486 * Argument may be modified (for termination).
487 * Returns *cp if parsing succeeds.
488 * *cp is set to the start of the next field, if one was found.
489 * The delimiter char, if present, is stored in delim.
490 * If this is the last field, *cp is set to NULL.
491 */
492static char *
493hpdelim2(char **cp, char *delim)
494{
495	char *s, *old;
496
497	if (cp == NULL || *cp == NULL)
498		return NULL;
499
500	old = s = *cp;
501	if (*s == '[') {
502		if ((s = strchr(s, ']')) == NULL)
503			return NULL;
504		else
505			s++;
506	} else if ((s = strpbrk(s, ":/")) == NULL)
507		s = *cp + strlen(*cp); /* skip to end (see first case below) */
508
509	switch (*s) {
510	case '\0':
511		*cp = NULL;	/* no more fields*/
512		break;
513
514	case ':':
515	case '/':
516		if (delim != NULL)
517			*delim = *s;
518		*s = '\0';	/* terminate */
519		*cp = s + 1;
520		break;
521
522	default:
523		return NULL;
524	}
525
526	return old;
527}
528
529char *
530hpdelim(char **cp)
531{
532	return hpdelim2(cp, NULL);
533}
534
535char *
536cleanhostname(char *host)
537{
538	if (*host == '[' && host[strlen(host) - 1] == ']') {
539		host[strlen(host) - 1] = '\0';
540		return (host + 1);
541	} else
542		return host;
543}
544
545char *
546colon(char *cp)
547{
548	int flag = 0;
549
550	if (*cp == ':')		/* Leading colon is part of file name. */
551		return NULL;
552	if (*cp == '[')
553		flag = 1;
554
555	for (; *cp; ++cp) {
556		if (*cp == '@' && *(cp+1) == '[')
557			flag = 1;
558		if (*cp == ']' && *(cp+1) == ':' && flag)
559			return (cp+1);
560		if (*cp == ':' && !flag)
561			return (cp);
562		if (*cp == '/')
563			return NULL;
564	}
565	return NULL;
566}
567
568/*
569 * Parse a [user@]host:[path] string.
570 * Caller must free returned user, host and path.
571 * Any of the pointer return arguments may be NULL (useful for syntax checking).
572 * If user was not specified then *userp will be set to NULL.
573 * If host was not specified then *hostp will be set to NULL.
574 * If path was not specified then *pathp will be set to ".".
575 * Returns 0 on success, -1 on failure.
576 */
577int
578parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp)
579{
580	char *user = NULL, *host = NULL, *path = NULL;
581	char *sdup, *tmp;
582	int ret = -1;
583
584	if (userp != NULL)
585		*userp = NULL;
586	if (hostp != NULL)
587		*hostp = NULL;
588	if (pathp != NULL)
589		*pathp = NULL;
590
591	sdup = xstrdup(s);
592
593	/* Check for remote syntax: [user@]host:[path] */
594	if ((tmp = colon(sdup)) == NULL)
595		goto out;
596
597	/* Extract optional path */
598	*tmp++ = '\0';
599	if (*tmp == '\0')
600		tmp = ".";
601	path = xstrdup(tmp);
602
603	/* Extract optional user and mandatory host */
604	tmp = strrchr(sdup, '@');
605	if (tmp != NULL) {
606		*tmp++ = '\0';
607		host = xstrdup(cleanhostname(tmp));
608		if (*sdup != '\0')
609			user = xstrdup(sdup);
610	} else {
611		host = xstrdup(cleanhostname(sdup));
612		user = NULL;
613	}
614
615	/* Success */
616	if (userp != NULL) {
617		*userp = user;
618		user = NULL;
619	}
620	if (hostp != NULL) {
621		*hostp = host;
622		host = NULL;
623	}
624	if (pathp != NULL) {
625		*pathp = path;
626		path = NULL;
627	}
628	ret = 0;
629out:
630	free(sdup);
631	free(user);
632	free(host);
633	free(path);
634	return ret;
635}
636
637/*
638 * Parse a [user@]host[:port] string.
639 * Caller must free returned user and host.
640 * Any of the pointer return arguments may be NULL (useful for syntax checking).
641 * If user was not specified then *userp will be set to NULL.
642 * If port was not specified then *portp will be -1.
643 * Returns 0 on success, -1 on failure.
644 */
645int
646parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
647{
648	char *sdup, *cp, *tmp;
649	char *user = NULL, *host = NULL;
650	int port = -1, ret = -1;
651
652	if (userp != NULL)
653		*userp = NULL;
654	if (hostp != NULL)
655		*hostp = NULL;
656	if (portp != NULL)
657		*portp = -1;
658
659	if ((sdup = tmp = strdup(s)) == NULL)
660		return -1;
661	/* Extract optional username */
662	if ((cp = strrchr(tmp, '@')) != NULL) {
663		*cp = '\0';
664		if (*tmp == '\0')
665			goto out;
666		if ((user = strdup(tmp)) == NULL)
667			goto out;
668		tmp = cp + 1;
669	}
670	/* Extract mandatory hostname */
671	if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0')
672		goto out;
673	host = xstrdup(cleanhostname(cp));
674	/* Convert and verify optional port */
675	if (tmp != NULL && *tmp != '\0') {
676		if ((port = a2port(tmp)) <= 0)
677			goto out;
678	}
679	/* Success */
680	if (userp != NULL) {
681		*userp = user;
682		user = NULL;
683	}
684	if (hostp != NULL) {
685		*hostp = host;
686		host = NULL;
687	}
688	if (portp != NULL)
689		*portp = port;
690	ret = 0;
691 out:
692	free(sdup);
693	free(user);
694	free(host);
695	return ret;
696}
697
698/*
699 * Converts a two-byte hex string to decimal.
700 * Returns the decimal value or -1 for invalid input.
701 */
702static int
703hexchar(const char *s)
704{
705	unsigned char result[2];
706	int i;
707
708	for (i = 0; i < 2; i++) {
709		if (s[i] >= '0' && s[i] <= '9')
710			result[i] = (unsigned char)(s[i] - '0');
711		else if (s[i] >= 'a' && s[i] <= 'f')
712			result[i] = (unsigned char)(s[i] - 'a') + 10;
713		else if (s[i] >= 'A' && s[i] <= 'F')
714			result[i] = (unsigned char)(s[i] - 'A') + 10;
715		else
716			return -1;
717	}
718	return (result[0] << 4) | result[1];
719}
720
721/*
722 * Decode an url-encoded string.
723 * Returns a newly allocated string on success or NULL on failure.
724 */
725static char *
726urldecode(const char *src)
727{
728	char *ret, *dst;
729	int ch;
730
731	ret = xmalloc(strlen(src) + 1);
732	for (dst = ret; *src != '\0'; src++) {
733		switch (*src) {
734		case '+':
735			*dst++ = ' ';
736			break;
737		case '%':
738			if (!isxdigit((unsigned char)src[1]) ||
739			    !isxdigit((unsigned char)src[2]) ||
740			    (ch = hexchar(src + 1)) == -1) {
741				free(ret);
742				return NULL;
743			}
744			*dst++ = ch;
745			src += 2;
746			break;
747		default:
748			*dst++ = *src;
749			break;
750		}
751	}
752	*dst = '\0';
753
754	return ret;
755}
756
757/*
758 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI.
759 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04
760 * Either user or path may be url-encoded (but not host or port).
761 * Caller must free returned user, host and path.
762 * Any of the pointer return arguments may be NULL (useful for syntax checking)
763 * but the scheme must always be specified.
764 * If user was not specified then *userp will be set to NULL.
765 * If port was not specified then *portp will be -1.
766 * If path was not specified then *pathp will be set to NULL.
767 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri.
768 */
769int
770parse_uri(const char *scheme, const char *uri, char **userp, char **hostp,
771    int *portp, char **pathp)
772{
773	char *uridup, *cp, *tmp, ch;
774	char *user = NULL, *host = NULL, *path = NULL;
775	int port = -1, ret = -1;
776	size_t len;
777
778	len = strlen(scheme);
779	if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0)
780		return 1;
781	uri += len + 3;
782
783	if (userp != NULL)
784		*userp = NULL;
785	if (hostp != NULL)
786		*hostp = NULL;
787	if (portp != NULL)
788		*portp = -1;
789	if (pathp != NULL)
790		*pathp = NULL;
791
792	uridup = tmp = xstrdup(uri);
793
794	/* Extract optional ssh-info (username + connection params) */
795	if ((cp = strchr(tmp, '@')) != NULL) {
796		char *delim;
797
798		*cp = '\0';
799		/* Extract username and connection params */
800		if ((delim = strchr(tmp, ';')) != NULL) {
801			/* Just ignore connection params for now */
802			*delim = '\0';
803		}
804		if (*tmp == '\0') {
805			/* Empty username */
806			goto out;
807		}
808		if ((user = urldecode(tmp)) == NULL)
809			goto out;
810		tmp = cp + 1;
811	}
812
813	/* Extract mandatory hostname */
814	if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0')
815		goto out;
816	host = xstrdup(cleanhostname(cp));
817	if (!valid_domain(host, 0, NULL))
818		goto out;
819
820	if (tmp != NULL && *tmp != '\0') {
821		if (ch == ':') {
822			/* Convert and verify port. */
823			if ((cp = strchr(tmp, '/')) != NULL)
824				*cp = '\0';
825			if ((port = a2port(tmp)) <= 0)
826				goto out;
827			tmp = cp ? cp + 1 : NULL;
828		}
829		if (tmp != NULL && *tmp != '\0') {
830			/* Extract optional path */
831			if ((path = urldecode(tmp)) == NULL)
832				goto out;
833		}
834	}
835
836	/* Success */
837	if (userp != NULL) {
838		*userp = user;
839		user = NULL;
840	}
841	if (hostp != NULL) {
842		*hostp = host;
843		host = NULL;
844	}
845	if (portp != NULL)
846		*portp = port;
847	if (pathp != NULL) {
848		*pathp = path;
849		path = NULL;
850	}
851	ret = 0;
852 out:
853	free(uridup);
854	free(user);
855	free(host);
856	free(path);
857	return ret;
858}
859
860/* function to assist building execv() arguments */
861void
862addargs(arglist *args, char *fmt, ...)
863{
864	va_list ap;
865	char *cp;
866	u_int nalloc;
867	int r;
868
869	va_start(ap, fmt);
870	r = vasprintf(&cp, fmt, ap);
871	va_end(ap);
872	if (r == -1)
873		fatal("addargs: argument too long");
874
875	nalloc = args->nalloc;
876	if (args->list == NULL) {
877		nalloc = 32;
878		args->num = 0;
879	} else if (args->num+2 >= nalloc)
880		nalloc *= 2;
881
882	args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *));
883	args->nalloc = nalloc;
884	args->list[args->num++] = cp;
885	args->list[args->num] = NULL;
886}
887
888void
889replacearg(arglist *args, u_int which, char *fmt, ...)
890{
891	va_list ap;
892	char *cp;
893	int r;
894
895	va_start(ap, fmt);
896	r = vasprintf(&cp, fmt, ap);
897	va_end(ap);
898	if (r == -1)
899		fatal("replacearg: argument too long");
900
901	if (which >= args->num)
902		fatal("replacearg: tried to replace invalid arg %d >= %d",
903		    which, args->num);
904	free(args->list[which]);
905	args->list[which] = cp;
906}
907
908void
909freeargs(arglist *args)
910{
911	u_int i;
912
913	if (args->list != NULL) {
914		for (i = 0; i < args->num; i++)
915			free(args->list[i]);
916		free(args->list);
917		args->nalloc = args->num = 0;
918		args->list = NULL;
919	}
920}
921
922/*
923 * Expands tildes in the file name.  Returns data allocated by xmalloc.
924 * Warning: this calls getpw*.
925 */
926char *
927tilde_expand_filename(const char *filename, uid_t uid)
928{
929	const char *path, *sep;
930	char user[128], *ret;
931	struct passwd *pw;
932	u_int len, slash;
933
934	if (*filename != '~')
935		return (xstrdup(filename));
936	filename++;
937
938	path = strchr(filename, '/');
939	if (path != NULL && path > filename) {		/* ~user/path */
940		slash = path - filename;
941		if (slash > sizeof(user) - 1)
942			fatal("tilde_expand_filename: ~username too long");
943		memcpy(user, filename, slash);
944		user[slash] = '\0';
945		if ((pw = getpwnam(user)) == NULL)
946			fatal("tilde_expand_filename: No such user %s", user);
947	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
948		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
949
950	/* Make sure directory has a trailing '/' */
951	len = strlen(pw->pw_dir);
952	if (len == 0 || pw->pw_dir[len - 1] != '/')
953		sep = "/";
954	else
955		sep = "";
956
957	/* Skip leading '/' from specified path */
958	if (path != NULL)
959		filename = path + 1;
960
961	if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX)
962		fatal("tilde_expand_filename: Path too long");
963
964	return (ret);
965}
966
967/*
968 * Expand a string with a set of %[char] escapes. A number of escapes may be
969 * specified as (char *escape_chars, char *replacement) pairs. The list must
970 * be terminated by a NULL escape_char. Returns replaced string in memory
971 * allocated by xmalloc.
972 */
973char *
974percent_expand(const char *string, ...)
975{
976#define EXPAND_MAX_KEYS	16
977	u_int num_keys, i, j;
978	struct {
979		const char *key;
980		const char *repl;
981	} keys[EXPAND_MAX_KEYS];
982	char buf[4096];
983	va_list ap;
984
985	/* Gather keys */
986	va_start(ap, string);
987	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
988		keys[num_keys].key = va_arg(ap, char *);
989		if (keys[num_keys].key == NULL)
990			break;
991		keys[num_keys].repl = va_arg(ap, char *);
992		if (keys[num_keys].repl == NULL)
993			fatal("%s: NULL replacement", __func__);
994	}
995	if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
996		fatal("%s: too many keys", __func__);
997	va_end(ap);
998
999	/* Expand string */
1000	*buf = '\0';
1001	for (i = 0; *string != '\0'; string++) {
1002		if (*string != '%') {
1003 append:
1004			buf[i++] = *string;
1005			if (i >= sizeof(buf))
1006				fatal("%s: string too long", __func__);
1007			buf[i] = '\0';
1008			continue;
1009		}
1010		string++;
1011		/* %% case */
1012		if (*string == '%')
1013			goto append;
1014		if (*string == '\0')
1015			fatal("%s: invalid format", __func__);
1016		for (j = 0; j < num_keys; j++) {
1017			if (strchr(keys[j].key, *string) != NULL) {
1018				i = strlcat(buf, keys[j].repl, sizeof(buf));
1019				if (i >= sizeof(buf))
1020					fatal("%s: string too long", __func__);
1021				break;
1022			}
1023		}
1024		if (j >= num_keys)
1025			fatal("%s: unknown key %%%c", __func__, *string);
1026	}
1027	return (xstrdup(buf));
1028#undef EXPAND_MAX_KEYS
1029}
1030
1031int
1032tun_open(int tun, int mode, char **ifname)
1033{
1034#if defined(CUSTOM_SYS_TUN_OPEN)
1035	return (sys_tun_open(tun, mode, ifname));
1036#elif defined(SSH_TUN_OPENBSD)
1037	struct ifreq ifr;
1038	char name[100];
1039	int fd = -1, sock;
1040	const char *tunbase = "tun";
1041
1042	if (ifname != NULL)
1043		*ifname = NULL;
1044
1045	if (mode == SSH_TUNMODE_ETHERNET)
1046		tunbase = "tap";
1047
1048	/* Open the tunnel device */
1049	if (tun <= SSH_TUNID_MAX) {
1050		snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
1051		fd = open(name, O_RDWR);
1052	} else if (tun == SSH_TUNID_ANY) {
1053		for (tun = 100; tun >= 0; tun--) {
1054			snprintf(name, sizeof(name), "/dev/%s%d",
1055			    tunbase, tun);
1056			if ((fd = open(name, O_RDWR)) >= 0)
1057				break;
1058		}
1059	} else {
1060		debug("%s: invalid tunnel %u", __func__, tun);
1061		return -1;
1062	}
1063
1064	if (fd < 0) {
1065		debug("%s: %s open: %s", __func__, name, strerror(errno));
1066		return -1;
1067	}
1068
1069	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
1070
1071	/* Bring interface up if it is not already */
1072	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
1073	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1074		goto failed;
1075
1076	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
1077		debug("%s: get interface %s flags: %s", __func__,
1078		    ifr.ifr_name, strerror(errno));
1079		goto failed;
1080	}
1081
1082	if (!(ifr.ifr_flags & IFF_UP)) {
1083		ifr.ifr_flags |= IFF_UP;
1084		if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
1085			debug("%s: activate interface %s: %s", __func__,
1086			    ifr.ifr_name, strerror(errno));
1087			goto failed;
1088		}
1089	}
1090
1091	if (ifname != NULL)
1092		*ifname = xstrdup(ifr.ifr_name);
1093
1094	close(sock);
1095	return fd;
1096
1097 failed:
1098	if (fd >= 0)
1099		close(fd);
1100	if (sock >= 0)
1101		close(sock);
1102	return -1;
1103#else
1104	error("Tunnel interfaces are not supported on this platform");
1105	return (-1);
1106#endif
1107}
1108
1109void
1110sanitise_stdfd(void)
1111{
1112	int nullfd, dupfd;
1113
1114	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1115		fprintf(stderr, "Couldn't open /dev/null: %s\n",
1116		    strerror(errno));
1117		exit(1);
1118	}
1119	while (++dupfd <= STDERR_FILENO) {
1120		/* Only populate closed fds. */
1121		if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
1122			if (dup2(nullfd, dupfd) == -1) {
1123				fprintf(stderr, "dup2: %s\n", strerror(errno));
1124				exit(1);
1125			}
1126		}
1127	}
1128	if (nullfd > STDERR_FILENO)
1129		close(nullfd);
1130}
1131
1132char *
1133tohex(const void *vp, size_t l)
1134{
1135	const u_char *p = (const u_char *)vp;
1136	char b[3], *r;
1137	size_t i, hl;
1138
1139	if (l > 65536)
1140		return xstrdup("tohex: length > 65536");
1141
1142	hl = l * 2 + 1;
1143	r = xcalloc(1, hl);
1144	for (i = 0; i < l; i++) {
1145		snprintf(b, sizeof(b), "%02x", p[i]);
1146		strlcat(r, b, hl);
1147	}
1148	return (r);
1149}
1150
1151u_int64_t
1152get_u64(const void *vp)
1153{
1154	const u_char *p = (const u_char *)vp;
1155	u_int64_t v;
1156
1157	v  = (u_int64_t)p[0] << 56;
1158	v |= (u_int64_t)p[1] << 48;
1159	v |= (u_int64_t)p[2] << 40;
1160	v |= (u_int64_t)p[3] << 32;
1161	v |= (u_int64_t)p[4] << 24;
1162	v |= (u_int64_t)p[5] << 16;
1163	v |= (u_int64_t)p[6] << 8;
1164	v |= (u_int64_t)p[7];
1165
1166	return (v);
1167}
1168
1169u_int32_t
1170get_u32(const void *vp)
1171{
1172	const u_char *p = (const u_char *)vp;
1173	u_int32_t v;
1174
1175	v  = (u_int32_t)p[0] << 24;
1176	v |= (u_int32_t)p[1] << 16;
1177	v |= (u_int32_t)p[2] << 8;
1178	v |= (u_int32_t)p[3];
1179
1180	return (v);
1181}
1182
1183u_int32_t
1184get_u32_le(const void *vp)
1185{
1186	const u_char *p = (const u_char *)vp;
1187	u_int32_t v;
1188
1189	v  = (u_int32_t)p[0];
1190	v |= (u_int32_t)p[1] << 8;
1191	v |= (u_int32_t)p[2] << 16;
1192	v |= (u_int32_t)p[3] << 24;
1193
1194	return (v);
1195}
1196
1197u_int16_t
1198get_u16(const void *vp)
1199{
1200	const u_char *p = (const u_char *)vp;
1201	u_int16_t v;
1202
1203	v  = (u_int16_t)p[0] << 8;
1204	v |= (u_int16_t)p[1];
1205
1206	return (v);
1207}
1208
1209void
1210put_u64(void *vp, u_int64_t v)
1211{
1212	u_char *p = (u_char *)vp;
1213
1214	p[0] = (u_char)(v >> 56) & 0xff;
1215	p[1] = (u_char)(v >> 48) & 0xff;
1216	p[2] = (u_char)(v >> 40) & 0xff;
1217	p[3] = (u_char)(v >> 32) & 0xff;
1218	p[4] = (u_char)(v >> 24) & 0xff;
1219	p[5] = (u_char)(v >> 16) & 0xff;
1220	p[6] = (u_char)(v >> 8) & 0xff;
1221	p[7] = (u_char)v & 0xff;
1222}
1223
1224void
1225put_u32(void *vp, u_int32_t v)
1226{
1227	u_char *p = (u_char *)vp;
1228
1229	p[0] = (u_char)(v >> 24) & 0xff;
1230	p[1] = (u_char)(v >> 16) & 0xff;
1231	p[2] = (u_char)(v >> 8) & 0xff;
1232	p[3] = (u_char)v & 0xff;
1233}
1234
1235void
1236put_u32_le(void *vp, u_int32_t v)
1237{
1238	u_char *p = (u_char *)vp;
1239
1240	p[0] = (u_char)v & 0xff;
1241	p[1] = (u_char)(v >> 8) & 0xff;
1242	p[2] = (u_char)(v >> 16) & 0xff;
1243	p[3] = (u_char)(v >> 24) & 0xff;
1244}
1245
1246void
1247put_u16(void *vp, u_int16_t v)
1248{
1249	u_char *p = (u_char *)vp;
1250
1251	p[0] = (u_char)(v >> 8) & 0xff;
1252	p[1] = (u_char)v & 0xff;
1253}
1254
1255void
1256ms_subtract_diff(struct timeval *start, int *ms)
1257{
1258	struct timeval diff, finish;
1259
1260	monotime_tv(&finish);
1261	timersub(&finish, start, &diff);
1262	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
1263}
1264
1265void
1266ms_to_timeval(struct timeval *tv, int ms)
1267{
1268	if (ms < 0)
1269		ms = 0;
1270	tv->tv_sec = ms / 1000;
1271	tv->tv_usec = (ms % 1000) * 1000;
1272}
1273
1274void
1275monotime_ts(struct timespec *ts)
1276{
1277	struct timeval tv;
1278#if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \
1279    defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME))
1280	static int gettime_failed = 0;
1281
1282	if (!gettime_failed) {
1283# ifdef CLOCK_BOOTTIME
1284		if (clock_gettime(CLOCK_BOOTTIME, ts) == 0)
1285			return;
1286# endif /* CLOCK_BOOTTIME */
1287# ifdef CLOCK_MONOTONIC
1288		if (clock_gettime(CLOCK_MONOTONIC, ts) == 0)
1289			return;
1290# endif /* CLOCK_MONOTONIC */
1291# ifdef CLOCK_REALTIME
1292		/* Not monotonic, but we're almost out of options here. */
1293		if (clock_gettime(CLOCK_REALTIME, ts) == 0)
1294			return;
1295# endif /* CLOCK_REALTIME */
1296		debug3("clock_gettime: %s", strerror(errno));
1297		gettime_failed = 1;
1298	}
1299#endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */
1300	gettimeofday(&tv, NULL);
1301	ts->tv_sec = tv.tv_sec;
1302	ts->tv_nsec = (long)tv.tv_usec * 1000;
1303}
1304
1305void
1306monotime_tv(struct timeval *tv)
1307{
1308	struct timespec ts;
1309
1310	monotime_ts(&ts);
1311	tv->tv_sec = ts.tv_sec;
1312	tv->tv_usec = ts.tv_nsec / 1000;
1313}
1314
1315time_t
1316monotime(void)
1317{
1318	struct timespec ts;
1319
1320	monotime_ts(&ts);
1321	return ts.tv_sec;
1322}
1323
1324double
1325monotime_double(void)
1326{
1327	struct timespec ts;
1328
1329	monotime_ts(&ts);
1330	return ts.tv_sec + ((double)ts.tv_nsec / 1000000000);
1331}
1332
1333void
1334bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
1335{
1336	bw->buflen = buflen;
1337	bw->rate = kbps;
1338	bw->thresh = bw->rate;
1339	bw->lamt = 0;
1340	timerclear(&bw->bwstart);
1341	timerclear(&bw->bwend);
1342}
1343
1344/* Callback from read/write loop to insert bandwidth-limiting delays */
1345void
1346bandwidth_limit(struct bwlimit *bw, size_t read_len)
1347{
1348	u_int64_t waitlen;
1349	struct timespec ts, rm;
1350
1351	if (!timerisset(&bw->bwstart)) {
1352		monotime_tv(&bw->bwstart);
1353		return;
1354	}
1355
1356	bw->lamt += read_len;
1357	if (bw->lamt < bw->thresh)
1358		return;
1359
1360	monotime_tv(&bw->bwend);
1361	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
1362	if (!timerisset(&bw->bwend))
1363		return;
1364
1365	bw->lamt *= 8;
1366	waitlen = (double)1000000L * bw->lamt / bw->rate;
1367
1368	bw->bwstart.tv_sec = waitlen / 1000000L;
1369	bw->bwstart.tv_usec = waitlen % 1000000L;
1370
1371	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
1372		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
1373
1374		/* Adjust the wait time */
1375		if (bw->bwend.tv_sec) {
1376			bw->thresh /= 2;
1377			if (bw->thresh < bw->buflen / 4)
1378				bw->thresh = bw->buflen / 4;
1379		} else if (bw->bwend.tv_usec < 10000) {
1380			bw->thresh *= 2;
1381			if (bw->thresh > bw->buflen * 8)
1382				bw->thresh = bw->buflen * 8;
1383		}
1384
1385		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
1386		while (nanosleep(&ts, &rm) == -1) {
1387			if (errno != EINTR)
1388				break;
1389			ts = rm;
1390		}
1391	}
1392
1393	bw->lamt = 0;
1394	monotime_tv(&bw->bwstart);
1395}
1396
1397/* Make a template filename for mk[sd]temp() */
1398void
1399mktemp_proto(char *s, size_t len)
1400{
1401	const char *tmpdir;
1402	int r;
1403
1404	if ((tmpdir = getenv("TMPDIR")) != NULL) {
1405		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
1406		if (r > 0 && (size_t)r < len)
1407			return;
1408	}
1409	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
1410	if (r < 0 || (size_t)r >= len)
1411		fatal("%s: template string too short", __func__);
1412}
1413
1414static const struct {
1415	const char *name;
1416	int value;
1417} ipqos[] = {
1418	{ "none", INT_MAX },		/* can't use 0 here; that's CS0 */
1419	{ "af11", IPTOS_DSCP_AF11 },
1420	{ "af12", IPTOS_DSCP_AF12 },
1421	{ "af13", IPTOS_DSCP_AF13 },
1422	{ "af21", IPTOS_DSCP_AF21 },
1423	{ "af22", IPTOS_DSCP_AF22 },
1424	{ "af23", IPTOS_DSCP_AF23 },
1425	{ "af31", IPTOS_DSCP_AF31 },
1426	{ "af32", IPTOS_DSCP_AF32 },
1427	{ "af33", IPTOS_DSCP_AF33 },
1428	{ "af41", IPTOS_DSCP_AF41 },
1429	{ "af42", IPTOS_DSCP_AF42 },
1430	{ "af43", IPTOS_DSCP_AF43 },
1431	{ "cs0", IPTOS_DSCP_CS0 },
1432	{ "cs1", IPTOS_DSCP_CS1 },
1433	{ "cs2", IPTOS_DSCP_CS2 },
1434	{ "cs3", IPTOS_DSCP_CS3 },
1435	{ "cs4", IPTOS_DSCP_CS4 },
1436	{ "cs5", IPTOS_DSCP_CS5 },
1437	{ "cs6", IPTOS_DSCP_CS6 },
1438	{ "cs7", IPTOS_DSCP_CS7 },
1439	{ "ef", IPTOS_DSCP_EF },
1440	{ "lowdelay", IPTOS_LOWDELAY },
1441	{ "throughput", IPTOS_THROUGHPUT },
1442	{ "reliability", IPTOS_RELIABILITY },
1443	{ NULL, -1 }
1444};
1445
1446int
1447parse_ipqos(const char *cp)
1448{
1449	u_int i;
1450	char *ep;
1451	long val;
1452
1453	if (cp == NULL)
1454		return -1;
1455	for (i = 0; ipqos[i].name != NULL; i++) {
1456		if (strcasecmp(cp, ipqos[i].name) == 0)
1457			return ipqos[i].value;
1458	}
1459	/* Try parsing as an integer */
1460	val = strtol(cp, &ep, 0);
1461	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1462		return -1;
1463	return val;
1464}
1465
1466const char *
1467iptos2str(int iptos)
1468{
1469	int i;
1470	static char iptos_str[sizeof "0xff"];
1471
1472	for (i = 0; ipqos[i].name != NULL; i++) {
1473		if (ipqos[i].value == iptos)
1474			return ipqos[i].name;
1475	}
1476	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1477	return iptos_str;
1478}
1479
1480void
1481lowercase(char *s)
1482{
1483	for (; *s; s++)
1484		*s = tolower((u_char)*s);
1485}
1486
1487int
1488unix_listener(const char *path, int backlog, int unlink_first)
1489{
1490	struct sockaddr_un sunaddr;
1491	int saved_errno, sock;
1492
1493	memset(&sunaddr, 0, sizeof(sunaddr));
1494	sunaddr.sun_family = AF_UNIX;
1495	if (strlcpy(sunaddr.sun_path, path,
1496	    sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1497		error("%s: path \"%s\" too long for Unix domain socket",
1498		    __func__, path);
1499		errno = ENAMETOOLONG;
1500		return -1;
1501	}
1502
1503	sock = socket(PF_UNIX, SOCK_STREAM, 0);
1504	if (sock < 0) {
1505		saved_errno = errno;
1506		error("%s: socket: %.100s", __func__, strerror(errno));
1507		errno = saved_errno;
1508		return -1;
1509	}
1510	if (unlink_first == 1) {
1511		if (unlink(path) != 0 && errno != ENOENT)
1512			error("unlink(%s): %.100s", path, strerror(errno));
1513	}
1514	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
1515		saved_errno = errno;
1516		error("%s: cannot bind to path %s: %s",
1517		    __func__, path, strerror(errno));
1518		close(sock);
1519		errno = saved_errno;
1520		return -1;
1521	}
1522	if (listen(sock, backlog) < 0) {
1523		saved_errno = errno;
1524		error("%s: cannot listen on path %s: %s",
1525		    __func__, path, strerror(errno));
1526		close(sock);
1527		unlink(path);
1528		errno = saved_errno;
1529		return -1;
1530	}
1531	return sock;
1532}
1533
1534void
1535sock_set_v6only(int s)
1536{
1537#if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
1538	int on = 1;
1539
1540	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1541	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1542		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1543#endif
1544}
1545
1546/*
1547 * Compares two strings that maybe be NULL. Returns non-zero if strings
1548 * are both NULL or are identical, returns zero otherwise.
1549 */
1550static int
1551strcmp_maybe_null(const char *a, const char *b)
1552{
1553	if ((a == NULL && b != NULL) || (a != NULL && b == NULL))
1554		return 0;
1555	if (a != NULL && strcmp(a, b) != 0)
1556		return 0;
1557	return 1;
1558}
1559
1560/*
1561 * Compare two forwards, returning non-zero if they are identical or
1562 * zero otherwise.
1563 */
1564int
1565forward_equals(const struct Forward *a, const struct Forward *b)
1566{
1567	if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0)
1568		return 0;
1569	if (a->listen_port != b->listen_port)
1570		return 0;
1571	if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0)
1572		return 0;
1573	if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0)
1574		return 0;
1575	if (a->connect_port != b->connect_port)
1576		return 0;
1577	if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0)
1578		return 0;
1579	/* allocated_port and handle are not checked */
1580	return 1;
1581}
1582
1583/* returns 1 if process is already daemonized, 0 otherwise */
1584int
1585daemonized(void)
1586{
1587	int fd;
1588
1589	if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
1590		close(fd);
1591		return 0;	/* have controlling terminal */
1592	}
1593	if (getppid() != 1)
1594		return 0;	/* parent is not init */
1595	if (getsid(0) != getpid())
1596		return 0;	/* not session leader */
1597	debug3("already daemonized");
1598	return 1;
1599}
1600
1601
1602/*
1603 * Splits 's' into an argument vector. Handles quoted string and basic
1604 * escape characters (\\, \", \'). Caller must free the argument vector
1605 * and its members.
1606 */
1607int
1608argv_split(const char *s, int *argcp, char ***argvp)
1609{
1610	int r = SSH_ERR_INTERNAL_ERROR;
1611	int argc = 0, quote, i, j;
1612	char *arg, **argv = xcalloc(1, sizeof(*argv));
1613
1614	*argvp = NULL;
1615	*argcp = 0;
1616
1617	for (i = 0; s[i] != '\0'; i++) {
1618		/* Skip leading whitespace */
1619		if (s[i] == ' ' || s[i] == '\t')
1620			continue;
1621
1622		/* Start of a token */
1623		quote = 0;
1624		if (s[i] == '\\' &&
1625		    (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\'))
1626			i++;
1627		else if (s[i] == '\'' || s[i] == '"')
1628			quote = s[i++];
1629
1630		argv = xreallocarray(argv, (argc + 2), sizeof(*argv));
1631		arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1);
1632		argv[argc] = NULL;
1633
1634		/* Copy the token in, removing escapes */
1635		for (j = 0; s[i] != '\0'; i++) {
1636			if (s[i] == '\\') {
1637				if (s[i + 1] == '\'' ||
1638				    s[i + 1] == '\"' ||
1639				    s[i + 1] == '\\') {
1640					i++; /* Skip '\' */
1641					arg[j++] = s[i];
1642				} else {
1643					/* Unrecognised escape */
1644					arg[j++] = s[i];
1645				}
1646			} else if (quote == 0 && (s[i] == ' ' || s[i] == '\t'))
1647				break; /* done */
1648			else if (quote != 0 && s[i] == quote)
1649				break; /* done */
1650			else
1651				arg[j++] = s[i];
1652		}
1653		if (s[i] == '\0') {
1654			if (quote != 0) {
1655				/* Ran out of string looking for close quote */
1656				r = SSH_ERR_INVALID_FORMAT;
1657				goto out;
1658			}
1659			break;
1660		}
1661	}
1662	/* Success */
1663	*argcp = argc;
1664	*argvp = argv;
1665	argc = 0;
1666	argv = NULL;
1667	r = 0;
1668 out:
1669	if (argc != 0 && argv != NULL) {
1670		for (i = 0; i < argc; i++)
1671			free(argv[i]);
1672		free(argv);
1673	}
1674	return r;
1675}
1676
1677/*
1678 * Reassemble an argument vector into a string, quoting and escaping as
1679 * necessary. Caller must free returned string.
1680 */
1681char *
1682argv_assemble(int argc, char **argv)
1683{
1684	int i, j, ws, r;
1685	char c, *ret;
1686	struct sshbuf *buf, *arg;
1687
1688	if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL)
1689		fatal("%s: sshbuf_new failed", __func__);
1690
1691	for (i = 0; i < argc; i++) {
1692		ws = 0;
1693		sshbuf_reset(arg);
1694		for (j = 0; argv[i][j] != '\0'; j++) {
1695			r = 0;
1696			c = argv[i][j];
1697			switch (c) {
1698			case ' ':
1699			case '\t':
1700				ws = 1;
1701				r = sshbuf_put_u8(arg, c);
1702				break;
1703			case '\\':
1704			case '\'':
1705			case '"':
1706				if ((r = sshbuf_put_u8(arg, '\\')) != 0)
1707					break;
1708				/* FALLTHROUGH */
1709			default:
1710				r = sshbuf_put_u8(arg, c);
1711				break;
1712			}
1713			if (r != 0)
1714				fatal("%s: sshbuf_put_u8: %s",
1715				    __func__, ssh_err(r));
1716		}
1717		if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) ||
1718		    (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) ||
1719		    (r = sshbuf_putb(buf, arg)) != 0 ||
1720		    (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0))
1721			fatal("%s: buffer error: %s", __func__, ssh_err(r));
1722	}
1723	if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL)
1724		fatal("%s: malloc failed", __func__);
1725	memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf));
1726	ret[sshbuf_len(buf)] = '\0';
1727	sshbuf_free(buf);
1728	sshbuf_free(arg);
1729	return ret;
1730}
1731
1732/* Returns 0 if pid exited cleanly, non-zero otherwise */
1733int
1734exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)
1735{
1736	int status;
1737
1738	while (waitpid(pid, &status, 0) == -1) {
1739		if (errno != EINTR) {
1740			error("%s: waitpid: %s", tag, strerror(errno));
1741			return -1;
1742		}
1743	}
1744	if (WIFSIGNALED(status)) {
1745		error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status));
1746		return -1;
1747	} else if (WEXITSTATUS(status) != 0) {
1748		do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO,
1749		    "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status));
1750		return -1;
1751	}
1752	return 0;
1753}
1754
1755/*
1756 * Check a given path for security. This is defined as all components
1757 * of the path to the file must be owned by either the owner of
1758 * of the file or root and no directories must be group or world writable.
1759 *
1760 * XXX Should any specific check be done for sym links ?
1761 *
1762 * Takes a file name, its stat information (preferably from fstat() to
1763 * avoid races), the uid of the expected owner, their home directory and an
1764 * error buffer plus max size as arguments.
1765 *
1766 * Returns 0 on success and -1 on failure
1767 */
1768int
1769safe_path(const char *name, struct stat *stp, const char *pw_dir,
1770    uid_t uid, char *err, size_t errlen)
1771{
1772	char buf[PATH_MAX], homedir[PATH_MAX];
1773	char *cp;
1774	int comparehome = 0;
1775	struct stat st;
1776
1777	if (realpath(name, buf) == NULL) {
1778		snprintf(err, errlen, "realpath %s failed: %s", name,
1779		    strerror(errno));
1780		return -1;
1781	}
1782	if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
1783		comparehome = 1;
1784
1785	if (!S_ISREG(stp->st_mode)) {
1786		snprintf(err, errlen, "%s is not a regular file", buf);
1787		return -1;
1788	}
1789	if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) ||
1790	    (stp->st_mode & 022) != 0) {
1791		snprintf(err, errlen, "bad ownership or modes for file %s",
1792		    buf);
1793		return -1;
1794	}
1795
1796	/* for each component of the canonical path, walking upwards */
1797	for (;;) {
1798		if ((cp = dirname(buf)) == NULL) {
1799			snprintf(err, errlen, "dirname() failed");
1800			return -1;
1801		}
1802		strlcpy(buf, cp, sizeof(buf));
1803
1804		if (stat(buf, &st) < 0 ||
1805		    (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) ||
1806		    (st.st_mode & 022) != 0) {
1807			snprintf(err, errlen,
1808			    "bad ownership or modes for directory %s", buf);
1809			return -1;
1810		}
1811
1812		/* If are past the homedir then we can stop */
1813		if (comparehome && strcmp(homedir, buf) == 0)
1814			break;
1815
1816		/*
1817		 * dirname should always complete with a "/" path,
1818		 * but we can be paranoid and check for "." too
1819		 */
1820		if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
1821			break;
1822	}
1823	return 0;
1824}
1825
1826/*
1827 * Version of safe_path() that accepts an open file descriptor to
1828 * avoid races.
1829 *
1830 * Returns 0 on success and -1 on failure
1831 */
1832int
1833safe_path_fd(int fd, const char *file, struct passwd *pw,
1834    char *err, size_t errlen)
1835{
1836	struct stat st;
1837
1838	/* check the open file to avoid races */
1839	if (fstat(fd, &st) < 0) {
1840		snprintf(err, errlen, "cannot stat file %s: %s",
1841		    file, strerror(errno));
1842		return -1;
1843	}
1844	return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
1845}
1846
1847/*
1848 * Sets the value of the given variable in the environment.  If the variable
1849 * already exists, its value is overridden.
1850 */
1851void
1852child_set_env(char ***envp, u_int *envsizep, const char *name,
1853	const char *value)
1854{
1855	char **env;
1856	u_int envsize;
1857	u_int i, namelen;
1858
1859	if (strchr(name, '=') != NULL) {
1860		error("Invalid environment variable \"%.100s\"", name);
1861		return;
1862	}
1863
1864	/*
1865	 * If we're passed an uninitialized list, allocate a single null
1866	 * entry before continuing.
1867	 */
1868	if (*envp == NULL && *envsizep == 0) {
1869		*envp = xmalloc(sizeof(char *));
1870		*envp[0] = NULL;
1871		*envsizep = 1;
1872	}
1873
1874	/*
1875	 * Find the slot where the value should be stored.  If the variable
1876	 * already exists, we reuse the slot; otherwise we append a new slot
1877	 * at the end of the array, expanding if necessary.
1878	 */
1879	env = *envp;
1880	namelen = strlen(name);
1881	for (i = 0; env[i]; i++)
1882		if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
1883			break;
1884	if (env[i]) {
1885		/* Reuse the slot. */
1886		free(env[i]);
1887	} else {
1888		/* New variable.  Expand if necessary. */
1889		envsize = *envsizep;
1890		if (i >= envsize - 1) {
1891			if (envsize >= 1000)
1892				fatal("child_set_env: too many env vars");
1893			envsize += 50;
1894			env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
1895			*envsizep = envsize;
1896		}
1897		/* Need to set the NULL pointer at end of array beyond the new slot. */
1898		env[i + 1] = NULL;
1899	}
1900
1901	/* Allocate space and format the variable in the appropriate slot. */
1902	/* XXX xasprintf */
1903	env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
1904	snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
1905}
1906
1907/*
1908 * Check and optionally lowercase a domain name, also removes trailing '.'
1909 * Returns 1 on success and 0 on failure, storing an error message in errstr.
1910 */
1911int
1912valid_domain(char *name, int makelower, const char **errstr)
1913{
1914	size_t i, l = strlen(name);
1915	u_char c, last = '\0';
1916	static char errbuf[256];
1917
1918	if (l == 0) {
1919		strlcpy(errbuf, "empty domain name", sizeof(errbuf));
1920		goto bad;
1921	}
1922	if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) {
1923		snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" "
1924		    "starts with invalid character", name);
1925		goto bad;
1926	}
1927	for (i = 0; i < l; i++) {
1928		c = tolower((u_char)name[i]);
1929		if (makelower)
1930			name[i] = (char)c;
1931		if (last == '.' && c == '.') {
1932			snprintf(errbuf, sizeof(errbuf), "domain name "
1933			    "\"%.100s\" contains consecutive separators", name);
1934			goto bad;
1935		}
1936		if (c != '.' && c != '-' && !isalnum(c) &&
1937		    c != '_') /* technically invalid, but common */ {
1938			snprintf(errbuf, sizeof(errbuf), "domain name "
1939			    "\"%.100s\" contains invalid characters", name);
1940			goto bad;
1941		}
1942		last = c;
1943	}
1944	if (name[l - 1] == '.')
1945		name[l - 1] = '\0';
1946	if (errstr != NULL)
1947		*errstr = NULL;
1948	return 1;
1949bad:
1950	if (errstr != NULL)
1951		*errstr = errbuf;
1952	return 0;
1953}
1954
1955/*
1956 * Verify that a environment variable name (not including initial '$') is
1957 * valid; consisting of one or more alphanumeric or underscore characters only.
1958 * Returns 1 on valid, 0 otherwise.
1959 */
1960int
1961valid_env_name(const char *name)
1962{
1963	const char *cp;
1964
1965	if (name[0] == '\0')
1966		return 0;
1967	for (cp = name; *cp != '\0'; cp++) {
1968		if (!isalnum((u_char)*cp) && *cp != '_')
1969			return 0;
1970	}
1971	return 1;
1972}
1973
1974const char *
1975atoi_err(const char *nptr, int *val)
1976{
1977	const char *errstr = NULL;
1978	long long num;
1979
1980	if (nptr == NULL || *nptr == '\0')
1981		return "missing";
1982	num = strtonum(nptr, 0, INT_MAX, &errstr);
1983	if (errstr == NULL)
1984		*val = (int)num;
1985	return errstr;
1986}
1987
1988int
1989parse_absolute_time(const char *s, uint64_t *tp)
1990{
1991	struct tm tm;
1992	time_t tt;
1993	char buf[32], *fmt;
1994
1995	*tp = 0;
1996
1997	/*
1998	 * POSIX strptime says "The application shall ensure that there
1999	 * is white-space or other non-alphanumeric characters between
2000	 * any two conversion specifications" so arrange things this way.
2001	 */
2002	switch (strlen(s)) {
2003	case 8: /* YYYYMMDD */
2004		fmt = "%Y-%m-%d";
2005		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
2006		break;
2007	case 12: /* YYYYMMDDHHMM */
2008		fmt = "%Y-%m-%dT%H:%M";
2009		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s",
2010		    s, s + 4, s + 6, s + 8, s + 10);
2011		break;
2012	case 14: /* YYYYMMDDHHMMSS */
2013		fmt = "%Y-%m-%dT%H:%M:%S";
2014		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
2015		    s, s + 4, s + 6, s + 8, s + 10, s + 12);
2016		break;
2017	default:
2018		return SSH_ERR_INVALID_FORMAT;
2019	}
2020
2021	memset(&tm, 0, sizeof(tm));
2022	if (strptime(buf, fmt, &tm) == NULL)
2023		return SSH_ERR_INVALID_FORMAT;
2024	if ((tt = mktime(&tm)) < 0)
2025		return SSH_ERR_INVALID_FORMAT;
2026	/* success */
2027	*tp = (uint64_t)tt;
2028	return 0;
2029}
2030
2031void
2032format_absolute_time(uint64_t t, char *buf, size_t len)
2033{
2034	time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */
2035	struct tm tm;
2036
2037	localtime_r(&tt, &tm);
2038	strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
2039}
2040