[openssh.git] / misc.c

/*
 * Copyright (c) 2000 Markus Friedl.  All rights reserved.
 * Copyright (c) 2005 Damien Miller.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"

#include <sys/ioctl.h>
#include <netinet/tcp.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#ifdef SSH_TUN_OPENBSD
#include <net/if.h>
#endif

#include "misc.h"
#include "log.h"
#include "xmalloc.h"

/* remove newline at end of string */
char *
chop(char *s)
{
	char *t = s;
	while (*t) {
		if (*t == '\n' || *t == '\r') {
			*t = '\0';
			return s;
		}
		t++;
	}
	return s;

}

/* set/unset filedescriptor to non-blocking */
int
set_nonblock(int fd)
{
	int val;

	val = fcntl(fd, F_GETFL, 0);
	if (val < 0) {
		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
		return (-1);
	}
	if (val & O_NONBLOCK) {
		debug3("fd %d is O_NONBLOCK", fd);
		return (0);
	}
	debug2("fd %d setting O_NONBLOCK", fd);
	val |= O_NONBLOCK;
	if (fcntl(fd, F_SETFL, val) == -1) {
		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
		    strerror(errno));
		return (-1);
	}
	return (0);
}

int
unset_nonblock(int fd)
{
	int val;

	val = fcntl(fd, F_GETFL, 0);
	if (val < 0) {
		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
		return (-1);
	}
	if (!(val & O_NONBLOCK)) {
		debug3("fd %d is not O_NONBLOCK", fd);
		return (0);
	}
	debug("fd %d clearing O_NONBLOCK", fd);
	val &= ~O_NONBLOCK;
	if (fcntl(fd, F_SETFL, val) == -1) {
		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
		    fd, strerror(errno));
		return (-1);
	}
	return (0);
}

/* disable nagle on socket */
void
set_nodelay(int fd)
{
	int opt;
	socklen_t optlen;

	optlen = sizeof opt;
	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
		return;
	}
	if (opt == 1) {
		debug2("fd %d is TCP_NODELAY", fd);
		return;
	}
	opt = 1;
	debug2("fd %d setting TCP_NODELAY", fd);
	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
}

/* Characters considered whitespace in strsep calls. */
#define WHITESPACE " \t\r\n"
#define QUOTE	"\""

/* return next token in configuration line */
char *
strdelim(char **s)
{
	char *old;
	int wspace = 0;

	if (*s == NULL)
		return NULL;

	old = *s;

	*s = strpbrk(*s, WHITESPACE QUOTE "=");
	if (*s == NULL)
		return (old);

	if (*s[0] == '\"') {
		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
		/* Find matching quote */
		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
			return (NULL);		/* no matching quote */
		} else {
			*s[0] = '\0';
			return (old);
		}
	}

	/* Allow only one '=' to be skipped */
	if (*s[0] == '=')
		wspace = 1;
	*s[0] = '\0';

	/* Skip any extra whitespace after first token */
	*s += strspn(*s + 1, WHITESPACE) + 1;
	if (*s[0] == '=' && !wspace)
		*s += strspn(*s + 1, WHITESPACE) + 1;

	return (old);
}

struct passwd *
pwcopy(struct passwd *pw)
{
	struct passwd *copy = xcalloc(1, sizeof(*copy));

	copy->pw_name = xstrdup(pw->pw_name);
	copy->pw_passwd = xstrdup(pw->pw_passwd);
	copy->pw_gecos = xstrdup(pw->pw_gecos);
	copy->pw_uid = pw->pw_uid;
	copy->pw_gid = pw->pw_gid;
#ifdef HAVE_PW_EXPIRE_IN_PASSWD
	copy->pw_expire = pw->pw_expire;
#endif
#ifdef HAVE_PW_CHANGE_IN_PASSWD
	copy->pw_change = pw->pw_change;
#endif
#ifdef HAVE_PW_CLASS_IN_PASSWD
	copy->pw_class = xstrdup(pw->pw_class);
#endif
	copy->pw_dir = xstrdup(pw->pw_dir);
	copy->pw_shell = xstrdup(pw->pw_shell);
	return copy;
}

/*
 * Convert ASCII string to TCP/IP port number.
 * Port must be >0 and <=65535.
 * Return 0 if invalid.
 */
int
a2port(const char *s)
{
	long port;
	char *endp;

	errno = 0;
	port = strtol(s, &endp, 0);
	if (s == endp || *endp != '\0' ||
	    (errno == ERANGE && (port == LONG_MIN || port == LONG_MAX)) ||
	    port <= 0 || port > 65535)
		return 0;

	return port;
}

int
a2tun(const char *s, int *remote)
{
	const char *errstr = NULL;
	char *sp, *ep;
	int tun;

	if (remote != NULL) {
		*remote = SSH_TUNID_ANY;
		sp = xstrdup(s);
		if ((ep = strchr(sp, ':')) == NULL) {
			xfree(sp);
			return (a2tun(s, NULL));
		}
		ep[0] = '\0'; ep++;
		*remote = a2tun(ep, NULL);
		tun = a2tun(sp, NULL);
		xfree(sp);
		return (*remote == SSH_TUNID_ERR ? *remote : tun);
	}

	if (strcasecmp(s, "any") == 0)
		return (SSH_TUNID_ANY);

	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
	if (errstr != NULL)
		return (SSH_TUNID_ERR);

	return (tun);
}

#define SECONDS		1
#define MINUTES		(SECONDS * 60)
#define HOURS		(MINUTES * 60)
#define DAYS		(HOURS * 24)
#define WEEKS		(DAYS * 7)

/*
 * Convert a time string into seconds; format is
 * a sequence of:
 *      time[qualifier]
 *
 * Valid time qualifiers are:
 *      <none>  seconds
 *      s|S     seconds
 *      m|M     minutes
 *      h|H     hours
 *      d|D     days
 *      w|W     weeks
 *
 * Examples:
 *      90m     90 minutes
 *      1h30m   90 minutes
 *      2d      2 days
 *      1w      1 week
 *
 * Return -1 if time string is invalid.
 */
long
convtime(const char *s)
{
	long total, secs;
	const char *p;
	char *endp;

	errno = 0;
	total = 0;
	p = s;

	if (p == NULL || *p == '\0')
		return -1;

	while (*p) {
		secs = strtol(p, &endp, 10);
		if (p == endp ||
		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
		    secs < 0)
			return -1;

		switch (*endp++) {
		case '\0':
			endp--;
			break;
		case 's':
		case 'S':
			break;
		case 'm':
		case 'M':
			secs *= MINUTES;
			break;
		case 'h':
		case 'H':
			secs *= HOURS;
			break;
		case 'd':
		case 'D':
			secs *= DAYS;
			break;
		case 'w':
		case 'W':
			secs *= WEEKS;
			break;
		default:
			return -1;
		}
		total += secs;
		if (total < 0)
			return -1;
		p = endp;
	}

	return total;
}

/*
 * Search for next delimiter between hostnames/addresses and ports.
 * Argument may be modified (for termination).
 * Returns *cp if parsing succeeds.
 * *cp is set to the start of the next delimiter, if one was found.
 * If this is the last field, *cp is set to NULL.
 */
char *
hpdelim(char **cp)
{
	char *s, *old;

	if (cp == NULL || *cp == NULL)
		return NULL;

	old = s = *cp;
	if (*s == '[') {
		if ((s = strchr(s, ']')) == NULL)
			return NULL;
		else
			s++;
	} else if ((s = strpbrk(s, ":/")) == NULL)
		s = *cp + strlen(*cp); /* skip to end (see first case below) */

	switch (*s) {
	case '\0':
		*cp = NULL;	/* no more fields*/
		break;

	case ':':
	case '/':
		*s = '\0';	/* terminate */
		*cp = s + 1;
		break;

	default:
		return NULL;
	}

	return old;
}

char *
cleanhostname(char *host)
{
	if (*host == '[' && host[strlen(host) - 1] == ']') {
		host[strlen(host) - 1] = '\0';
		return (host + 1);
	} else
		return host;
}

char *
colon(char *cp)
{
	int flag = 0;

	if (*cp == ':')		/* Leading colon is part of file name. */
		return (0);
	if (*cp == '[')
		flag = 1;

	for (; *cp; ++cp) {
		if (*cp == '@' && *(cp+1) == '[')
			flag = 1;
		if (*cp == ']' && *(cp+1) == ':' && flag)
			return (cp+1);
		if (*cp == ':' && !flag)
			return (cp);
		if (*cp == '/')
			return (0);
	}
	return (0);
}

/* function to assist building execv() arguments */
void
addargs(arglist *args, char *fmt, ...)
{
	va_list ap;
	char *cp;
	u_int nalloc;
	int r;

	va_start(ap, fmt);
	r = vasprintf(&cp, fmt, ap);
	va_end(ap);
	if (r == -1)
		fatal("addargs: argument too long");

	nalloc = args->nalloc;
	if (args->list == NULL) {
		nalloc = 32;
		args->num = 0;
	} else if (args->num+2 >= nalloc)
		nalloc *= 2;

	args->list = xrealloc(args->list, nalloc, sizeof(char *));
	args->nalloc = nalloc;
	args->list[args->num++] = cp;
	args->list[args->num] = NULL;
}

void
replacearg(arglist *args, u_int which, char *fmt, ...)
{
	va_list ap;
	char *cp;
	int r;

	va_start(ap, fmt);
	r = vasprintf(&cp, fmt, ap);
	va_end(ap);
	if (r == -1)
		fatal("replacearg: argument too long");

	if (which >= args->num)
		fatal("replacearg: tried to replace invalid arg %d >= %d",
		    which, args->num);
	xfree(args->list[which]);
	args->list[which] = cp;
}

void
freeargs(arglist *args)
{
	u_int i;

	if (args->list != NULL) {
		for (i = 0; i < args->num; i++)
			xfree(args->list[i]);
		xfree(args->list);
		args->nalloc = args->num = 0;
		args->list = NULL;
	}
}

/*
 * Expands tildes in the file name.  Returns data allocated by xmalloc.
 * Warning: this calls getpw*.
 */
char *
tilde_expand_filename(const char *filename, uid_t uid)
{
	const char *path;
	char user[128], ret[MAXPATHLEN];
	struct passwd *pw;
	u_int len, slash;

	if (*filename != '~')
		return (xstrdup(filename));
	filename++;

	path = strchr(filename, '/');
	if (path != NULL && path > filename) {		/* ~user/path */
		slash = path - filename;
		if (slash > sizeof(user) - 1)
			fatal("tilde_expand_filename: ~username too long");
		memcpy(user, filename, slash);
		user[slash] = '\0';
		if ((pw = getpwnam(user)) == NULL)
			fatal("tilde_expand_filename: No such user %s", user);
	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
		fatal("tilde_expand_filename: No such uid %d", uid);

	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
		fatal("tilde_expand_filename: Path too long");

	/* Make sure directory has a trailing '/' */
	len = strlen(pw->pw_dir);
	if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
	    strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
		fatal("tilde_expand_filename: Path too long");

	/* Skip leading '/' from specified path */
	if (path != NULL)
		filename = path + 1;
	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
		fatal("tilde_expand_filename: Path too long");

	return (xstrdup(ret));
}

/*
 * Expand a string with a set of %[char] escapes. A number of escapes may be
 * specified as (char *escape_chars, char *replacement) pairs. The list must
 * be terminated by a NULL escape_char. Returns replaced string in memory
 * allocated by xmalloc.
 */
char *
percent_expand(const char *string, ...)
{
#define EXPAND_MAX_KEYS	16
	struct {
		const char *key;
		const char *repl;
	} keys[EXPAND_MAX_KEYS];
	u_int num_keys, i, j;
	char buf[4096];
	va_list ap;

	/* Gather keys */
	va_start(ap, string);
	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
		keys[num_keys].key = va_arg(ap, char *);
		if (keys[num_keys].key == NULL)
			break;
		keys[num_keys].repl = va_arg(ap, char *);
		if (keys[num_keys].repl == NULL)
			fatal("percent_expand: NULL replacement");
	}
	va_end(ap);

	if (num_keys >= EXPAND_MAX_KEYS)
		fatal("percent_expand: too many keys");

	/* Expand string */
	*buf = '\0';
	for (i = 0; *string != '\0'; string++) {
		if (*string != '%') {
 append:
			buf[i++] = *string;
			if (i >= sizeof(buf))
				fatal("percent_expand: string too long");
			buf[i] = '\0';
			continue;
		}
		string++;
		if (*string == '%')
			goto append;
		for (j = 0; j < num_keys; j++) {
			if (strchr(keys[j].key, *string) != NULL) {
				i = strlcat(buf, keys[j].repl, sizeof(buf));
				if (i >= sizeof(buf))
					fatal("percent_expand: string too long");
				break;
			}
		}
		if (j >= num_keys)
			fatal("percent_expand: unknown key %%%c", *string);
	}
	return (xstrdup(buf));
#undef EXPAND_MAX_KEYS
}

/*
 * Read an entire line from a public key file into a static buffer, discarding
 * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
 */
int
read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
   u_long *lineno)
{
	while (fgets(buf, bufsz, f) != NULL) {
		(*lineno)++;
		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
			return 0;
		} else {
			debug("%s: %s line %lu exceeds size limit", __func__,
			    filename, *lineno);
			/* discard remainder of line */
			while (fgetc(f) != '\n' && !feof(f))
				;	/* nothing */
		}
	}
	return -1;
}

int
tun_open(int tun, int mode)
{
#if defined(CUSTOM_SYS_TUN_OPEN)
	return (sys_tun_open(tun, mode));
#elif defined(SSH_TUN_OPENBSD)
	struct ifreq ifr;
	char name[100];
	int fd = -1, sock;

	/* Open the tunnel device */
	if (tun <= SSH_TUNID_MAX) {
		snprintf(name, sizeof(name), "/dev/tun%d", tun);
		fd = open(name, O_RDWR);
	} else if (tun == SSH_TUNID_ANY) {
		for (tun = 100; tun >= 0; tun--) {
			snprintf(name, sizeof(name), "/dev/tun%d", tun);
			if ((fd = open(name, O_RDWR)) >= 0)
				break;
		}
	} else {
		debug("%s: invalid tunnel %u", __func__, tun);
		return (-1);
	}

	if (fd < 0) {
		debug("%s: %s open failed: %s", __func__, name, strerror(errno));
		return (-1);
	}

	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);

	/* Set the tunnel device operation mode */
	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
		goto failed;

	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
		goto failed;

	/* Set interface mode */
	ifr.ifr_flags &= ~IFF_UP;
	if (mode == SSH_TUNMODE_ETHERNET)
		ifr.ifr_flags |= IFF_LINK0;
	else
		ifr.ifr_flags &= ~IFF_LINK0;
	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
		goto failed;

	/* Bring interface up */
	ifr.ifr_flags |= IFF_UP;
	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
		goto failed;

	close(sock);
	return (fd);

 failed:
	if (fd >= 0)
		close(fd);
	if (sock >= 0)
		close(sock);
	debug("%s: failed to set %s mode %d: %s", __func__, name,
	    mode, strerror(errno));
	return (-1);
#else
	error("Tunnel interfaces are not supported on this platform");
	return (-1);
#endif
}

void
sanitise_stdfd(void)
{
	int nullfd, dupfd;

	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
		fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
		exit(1);
	}
	while (++dupfd <= 2) {
		/* Only clobber closed fds */
		if (fcntl(dupfd, F_GETFL, 0) >= 0)
			continue;
		if (dup2(nullfd, dupfd) == -1) {
			fprintf(stderr, "dup2: %s", strerror(errno));
			exit(1);
		}
	}
	if (nullfd > 2)
		close(nullfd);
}

char *
tohex(const u_char *d, u_int l)
{
	char b[3], *r;
	u_int i, hl;

	hl = l * 2 + 1;
	r = xcalloc(1, hl);
	for (i = 0; i < l; i++) {
		snprintf(b, sizeof(b), "%02x", d[i]);
		strlcat(r, b, hl);
	}
	return (r);
}
Commit	Line	Data
bcbf86ec	1	/*
bcbf86ec	2	* Copyright (c) 2000 Markus Friedl. All rights reserved.
a980cbd7	3	* Copyright (c) 2005 Damien Miller. All rights reserved.
bcbf86ec	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	15	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	16	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	17	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	18	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	19	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	20	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	21	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	23	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
6d24277f	26	#include "includes.h"
bd7c69ea	27
bd7c69ea	28	#include <sys/ioctl.h>
6425cf65	29	#include <netinet/tcp.h>
a75f5360	30	#ifdef HAVE_PATHS_H
6f61e0ec	31	# include <paths.h>
a75f5360	32	#endif
1f1fbbd8	33	#ifdef SSH_TUN_OPENBSD
	34	#include <net/if.h>
	35	#endif
6d24277f	36
1aa00dcb	37	#include "misc.h"
42f11eb2	38	#include "log.h"
4ab21f86	39	#include "xmalloc.h"
6d24277f	40
255cabd9	41	/* remove newline at end of string */
6d24277f	42	char *
	43	chop(char *s)
	44	{
	45	char *t = s;
	46	while (*t) {
6aacefa7	47	if (t == '\n' \|\| t == '\r') {
6d24277f	48	*t = '\0';
	49	return s;
	50	}
	51	t++;
	52	}
	53	return s;
	54
	55	}
	56
255cabd9	57	/* set/unset filedescriptor to non-blocking */
170694d7	58	int
6d24277f	59	set_nonblock(int fd)
	60	{
	61	int val;
89aa792b	62
6d24277f	63	val = fcntl(fd, F_GETFL, 0);
	64	if (val < 0) {
	65	error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
170694d7	66	return (-1);
6d24277f	67	}
a22aff1f	68	if (val & O_NONBLOCK) {
170694d7	69	debug3("fd %d is O_NONBLOCK", fd);
170694d7	70	return (0);
a22aff1f	71	}
45c42d58	72	debug2("fd %d setting O_NONBLOCK", fd);
6d24277f	73	val \|= O_NONBLOCK;
170694d7	74	if (fcntl(fd, F_SETFL, val) == -1) {
	75	debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
	76	strerror(errno));
	77	return (-1);
	78	}
	79	return (0);
6d24277f	80	}
6d24277f	81
170694d7	82	int
89aa792b	83	unset_nonblock(int fd)
	84	{
	85	int val;
	86
	87	val = fcntl(fd, F_GETFL, 0);
	88	if (val < 0) {
	89	error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
170694d7	90	return (-1);
89aa792b	91	}
89aa792b	92	if (!(val & O_NONBLOCK)) {
170694d7	93	debug3("fd %d is not O_NONBLOCK", fd);
170694d7	94	return (0);
89aa792b	95	}
e04e7a19	96	debug("fd %d clearing O_NONBLOCK", fd);
89aa792b	97	val &= ~O_NONBLOCK;
170694d7	98	if (fcntl(fd, F_SETFL, val) == -1) {
170694d7	99	debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
c92ec40b	100	fd, strerror(errno));
170694d7	101	return (-1);
	102	}
	103	return (0);
89aa792b	104	}
89aa792b	105
bcc0381e	106	/* disable nagle on socket */
	107	void
	108	set_nodelay(int fd)
	109	{
3c05447a	110	int opt;
3c05447a	111	socklen_t optlen;
bcc0381e	112
811a6342	113	optlen = sizeof opt;
811a6342	114	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
f7fb35fe	115	debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
811a6342	116	return;
	117	}
	118	if (opt == 1) {
	119	debug2("fd %d is TCP_NODELAY", fd);
	120	return;
	121	}
	122	opt = 1;
6226a8f8	123	debug2("fd %d setting TCP_NODELAY", fd);
811a6342	124	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
bcc0381e	125	error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
	126	}
	127
6d24277f	128	/* Characters considered whitespace in strsep calls. */
6d24277f	129	#define WHITESPACE " \t\r\n"
533b9133	130	#define QUOTE "\""
6d24277f	131
255cabd9	132	/* return next token in configuration line */
6d24277f	133	char *
	134	strdelim(char **s)
	135	{
	136	char *old;
	137	int wspace = 0;
	138
	139	if (*s == NULL)
	140	return NULL;
	141
	142	old = *s;
	143
533b9133	144	s = strpbrk(s, WHITESPACE QUOTE "=");
6d24277f	145	if (*s == NULL)
	146	return (old);
	147
533b9133	148	if (*s[0] == '\"') {
	149	memmove(s, s + 1, strlen(s)); / move nul too */
	150	/* Find matching quote */
	151	if ((s = strpbrk(s, QUOTE)) == NULL) {
	152	return (NULL); /* no matching quote */
	153	} else {
	154	*s[0] = '\0';
	155	return (old);
	156	}
	157	}
	158
6d24277f	159	/* Allow only one '=' to be skipped */
	160	if (*s[0] == '=')
	161	wspace = 1;
	162	*s[0] = '\0';
	163
533b9133	164	/* Skip any extra whitespace after first token */
6d24277f	165	s += strspn(s + 1, WHITESPACE) + 1;
	166	if (*s[0] == '=' && !wspace)
	167	s += strspn(s + 1, WHITESPACE) + 1;
	168
	169	return (old);
	170	}
1aa00dcb	171
3b1a83df	172	struct passwd *
	173	pwcopy(struct passwd *pw)
	174	{
52e3daed	175	struct passwd copy = xcalloc(1, sizeof(copy));
5649fbbe	176
3b1a83df	177	copy->pw_name = xstrdup(pw->pw_name);
3b1a83df	178	copy->pw_passwd = xstrdup(pw->pw_passwd);
5649fbbe	179	copy->pw_gecos = xstrdup(pw->pw_gecos);
3b1a83df	180	copy->pw_uid = pw->pw_uid;
3b1a83df	181	copy->pw_gid = pw->pw_gid;
7751d4eb	182	#ifdef HAVE_PW_EXPIRE_IN_PASSWD
c4d49b85	183	copy->pw_expire = pw->pw_expire;
7751d4eb	184	#endif
7751d4eb	185	#ifdef HAVE_PW_CHANGE_IN_PASSWD
c4d49b85	186	copy->pw_change = pw->pw_change;
7751d4eb	187	#endif
2605addd	188	#ifdef HAVE_PW_CLASS_IN_PASSWD
3b1a83df	189	copy->pw_class = xstrdup(pw->pw_class);
2605addd	190	#endif
3b1a83df	191	copy->pw_dir = xstrdup(pw->pw_dir);
	192	copy->pw_shell = xstrdup(pw->pw_shell);
	193	return copy;
	194	}
	195
255cabd9	196	/*
	197	* Convert ASCII string to TCP/IP port number.
	198	* Port must be >0 and <=65535.
	199	* Return 0 if invalid.
	200	*/
	201	int
	202	a2port(const char *s)
2d2a2c65	203	{
	204	long port;
	205	char *endp;
	206
	207	errno = 0;
	208	port = strtol(s, &endp, 0);
	209	if (s == endp \|\| *endp != '\0' \|\|
	210	(errno == ERANGE && (port == LONG_MIN \|\| port == LONG_MAX)) \|\|
	211	port <= 0 \|\| port > 65535)
	212	return 0;
	213
	214	return port;
	215	}
	216
d20f3c9e	217	int
	218	a2tun(const char s, int remote)
	219	{
	220	const char *errstr = NULL;
	221	char sp, ep;
	222	int tun;
	223
	224	if (remote != NULL) {
a4f24bf8	225	*remote = SSH_TUNID_ANY;
d20f3c9e	226	sp = xstrdup(s);
	227	if ((ep = strchr(sp, ':')) == NULL) {
	228	xfree(sp);
	229	return (a2tun(s, NULL));
	230	}
	231	ep[0] = '\0'; ep++;
	232	*remote = a2tun(ep, NULL);
	233	tun = a2tun(sp, NULL);
	234	xfree(sp);
a4f24bf8	235	return (remote == SSH_TUNID_ERR ? remote : tun);
d20f3c9e	236	}
	237
	238	if (strcasecmp(s, "any") == 0)
a4f24bf8	239	return (SSH_TUNID_ANY);
d20f3c9e	240
a4f24bf8	241	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
	242	if (errstr != NULL)
	243	return (SSH_TUNID_ERR);
d20f3c9e	244
	245	return (tun);
	246	}
	247
e2b1fb42	248	#define SECONDS 1
	249	#define MINUTES (SECONDS * 60)
	250	#define HOURS (MINUTES * 60)
	251	#define DAYS (HOURS * 24)
	252	#define WEEKS (DAYS * 7)
	253
255cabd9	254	/*
	255	* Convert a time string into seconds; format is
	256	* a sequence of:
	257	* time[qualifier]
	258	*
	259	* Valid time qualifiers are:
	260	* <none> seconds
	261	* s\|S seconds
	262	* m\|M minutes
	263	* h\|H hours
	264	* d\|D days
	265	* w\|W weeks
	266	*
	267	* Examples:
	268	* 90m 90 minutes
	269	* 1h30m 90 minutes
	270	* 2d 2 days
	271	* 1w 1 week
	272	*
	273	* Return -1 if time string is invalid.
	274	*/
	275	long
	276	convtime(const char *s)
e2b1fb42	277	{
	278	long total, secs;
	279	const char *p;
	280	char *endp;
	281
	282	errno = 0;
	283	total = 0;
	284	p = s;
	285
	286	if (p == NULL \|\| *p == '\0')
	287	return -1;
	288
	289	while (*p) {
	290	secs = strtol(p, &endp, 10);
	291	if (p == endp \|\|
	292	(errno == ERANGE && (secs == LONG_MIN \|\| secs == LONG_MAX)) \|\|
	293	secs < 0)
	294	return -1;
	295
	296	switch (*endp++) {
	297	case '\0':
	298	endp--;
5ef36928	299	break;
e2b1fb42	300	case 's':
	301	case 'S':
	302	break;
	303	case 'm':
	304	case 'M':
	305	secs *= MINUTES;
	306	break;
	307	case 'h':
	308	case 'H':
	309	secs *= HOURS;
	310	break;
	311	case 'd':
	312	case 'D':
	313	secs *= DAYS;
	314	break;
	315	case 'w':
	316	case 'W':
	317	secs *= WEEKS;
	318	break;
	319	default:
	320	return -1;
	321	}
	322	total += secs;
	323	if (total < 0)
	324	return -1;
	325	p = endp;
	326	}
	327
	328	return total;
	329	}
	330
3867aa0a	331	/*
	332	* Search for next delimiter between hostnames/addresses and ports.
	333	* Argument may be modified (for termination).
	334	* Returns *cp if parsing succeeds.
	335	* *cp is set to the start of the next delimiter, if one was found.
	336	* If this is the last field, *cp is set to NULL.
	337	*/
	338	char *
	339	hpdelim(char **cp)
	340	{
	341	char s, old;
	342
	343	if (cp == NULL \|\| *cp == NULL)
	344	return NULL;
	345
	346	old = s = *cp;
	347	if (*s == '[') {
	348	if ((s = strchr(s, ']')) == NULL)
	349	return NULL;
	350	else
	351	s++;
	352	} else if ((s = strpbrk(s, ":/")) == NULL)
	353	s = cp + strlen(cp); /* skip to end (see first case below) */
	354
	355	switch (*s) {
	356	case '\0':
	357	cp = NULL; / no more fields*/
	358	break;
f8cc7664	359
3867aa0a	360	case ':':
	361	case '/':
	362	s = '\0'; / terminate */
	363	*cp = s + 1;
	364	break;
f8cc7664	365
3867aa0a	366	default:
	367	return NULL;
	368	}
	369
	370	return old;
	371	}
	372
1fcde3fe	373	char *
	374	cleanhostname(char *host)
	375	{
	376	if (*host == '[' && host[strlen(host) - 1] == ']') {
	377	host[strlen(host) - 1] = '\0';
	378	return (host + 1);
	379	} else
	380	return host;
	381	}
	382
	383	char *
	384	colon(char *cp)
	385	{
	386	int flag = 0;
	387
	388	if (cp == ':') / Leading colon is part of file name. */
	389	return (0);
	390	if (*cp == '[')
	391	flag = 1;
	392
	393	for (; *cp; ++cp) {
	394	if (cp == '@' && (cp+1) == '[')
	395	flag = 1;
	396	if (cp == ']' && (cp+1) == ':' && flag)
	397	return (cp+1);
	398	if (*cp == ':' && !flag)
	399	return (cp);
	400	if (*cp == '/')
	401	return (0);
	402	}
	403	return (0);
	404	}
	405
255cabd9	406	/* function to assist building execv() arguments */
8a624ebf	407	void
	408	addargs(arglist args, char fmt, ...)
	409	{
	410	va_list ap;
4116f5c0	411	char *cp;
9a995072	412	u_int nalloc;
4116f5c0	413	int r;
8a624ebf	414
8a624ebf	415	va_start(ap, fmt);
4116f5c0	416	r = vasprintf(&cp, fmt, ap);
8a624ebf	417	va_end(ap);
4116f5c0	418	if (r == -1)
4116f5c0	419	fatal("addargs: argument too long");
8a624ebf	420
c46e584f	421	nalloc = args->nalloc;
8a624ebf	422	if (args->list == NULL) {
c46e584f	423	nalloc = 32;
8a624ebf	424	args->num = 0;
c46e584f	425	} else if (args->num+2 >= nalloc)
c46e584f	426	nalloc *= 2;
8a624ebf	427
c5d10563	428	args->list = xrealloc(args->list, nalloc, sizeof(char *));
c46e584f	429	args->nalloc = nalloc;
4116f5c0	430	args->list[args->num++] = cp;
8a624ebf	431	args->list[args->num] = NULL;
8a624ebf	432	}
ea067773	433
4116f5c0	434	void
	435	replacearg(arglist args, u_int which, char fmt, ...)
	436	{
	437	va_list ap;
	438	char *cp;
	439	int r;
	440
	441	va_start(ap, fmt);
	442	r = vasprintf(&cp, fmt, ap);
	443	va_end(ap);
	444	if (r == -1)
	445	fatal("replacearg: argument too long");
	446
	447	if (which >= args->num)
	448	fatal("replacearg: tried to replace invalid arg %d >= %d",
	449	which, args->num);
	450	xfree(args->list[which]);
	451	args->list[which] = cp;
	452	}
	453
	454	void
	455	freeargs(arglist *args)
	456	{
	457	u_int i;
	458
	459	if (args->list != NULL) {
	460	for (i = 0; i < args->num; i++)
	461	xfree(args->list[i]);
	462	xfree(args->list);
	463	args->nalloc = args->num = 0;
	464	args->list = NULL;
	465	}
	466	}
	467
49e71137	468	/*
	469	* Expands tildes in the file name. Returns data allocated by xmalloc.
	470	* Warning: this calls getpw*.
	471	*/
	472	char *
	473	tilde_expand_filename(const char *filename, uid_t uid)
	474	{
	475	const char *path;
	476	char user[128], ret[MAXPATHLEN];
	477	struct passwd *pw;
2ceb8101	478	u_int len, slash;
49e71137	479
	480	if (*filename != '~')
	481	return (xstrdup(filename));
	482	filename++;
	483
	484	path = strchr(filename, '/');
	485	if (path != NULL && path > filename) { /* ~user/path */
2ceb8101	486	slash = path - filename;
2ceb8101	487	if (slash > sizeof(user) - 1)
49e71137	488	fatal("tilde_expand_filename: ~username too long");
2ceb8101	489	memcpy(user, filename, slash);
2ceb8101	490	user[slash] = '\0';
49e71137	491	if ((pw = getpwnam(user)) == NULL)
	492	fatal("tilde_expand_filename: No such user %s", user);
	493	} else if ((pw = getpwuid(uid)) == NULL) /* ~/path */
	494	fatal("tilde_expand_filename: No such uid %d", uid);
	495
	496	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
	497	fatal("tilde_expand_filename: Path too long");
	498
	499	/* Make sure directory has a trailing '/' */
	500	len = strlen(pw->pw_dir);
	501	if ((len == 0 \|\| pw->pw_dir[len - 1] != '/') &&
	502	strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
	503	fatal("tilde_expand_filename: Path too long");
	504
	505	/* Skip leading '/' from specified path */
	506	if (path != NULL)
	507	filename = path + 1;
	508	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
	509	fatal("tilde_expand_filename: Path too long");
	510
	511	return (xstrdup(ret));
	512	}
	513
a980cbd7	514	/*
	515	* Expand a string with a set of %[char] escapes. A number of escapes may be
	516	* specified as (char escape_chars, char replacement) pairs. The list must
6381acf0	517	* be terminated by a NULL escape_char. Returns replaced string in memory
a980cbd7	518	* allocated by xmalloc.
	519	*/
	520	char *
	521	percent_expand(const char *string, ...)
	522	{
	523	#define EXPAND_MAX_KEYS 16
	524	struct {
	525	const char *key;
	526	const char *repl;
	527	} keys[EXPAND_MAX_KEYS];
2ceb8101	528	u_int num_keys, i, j;
a980cbd7	529	char buf[4096];
	530	va_list ap;
	531
	532	/* Gather keys */
	533	va_start(ap, string);
	534	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
	535	keys[num_keys].key = va_arg(ap, char *);
	536	if (keys[num_keys].key == NULL)
	537	break;
	538	keys[num_keys].repl = va_arg(ap, char *);
	539	if (keys[num_keys].repl == NULL)
	540	fatal("percent_expand: NULL replacement");
	541	}
	542	va_end(ap);
	543
	544	if (num_keys >= EXPAND_MAX_KEYS)
	545	fatal("percent_expand: too many keys");
	546
	547	/* Expand string */
	548	*buf = '\0';
	549	for (i = 0; *string != '\0'; string++) {
	550	if (*string != '%') {
	551	append:
	552	buf[i++] = *string;
	553	if (i >= sizeof(buf))
	554	fatal("percent_expand: string too long");
	555	buf[i] = '\0';
	556	continue;
	557	}
	558	string++;
	559	if (*string == '%')
	560	goto append;
	561	for (j = 0; j < num_keys; j++) {
	562	if (strchr(keys[j].key, *string) != NULL) {
	563	i = strlcat(buf, keys[j].repl, sizeof(buf));
	564	if (i >= sizeof(buf))
	565	fatal("percent_expand: string too long");
	566	break;
	567	}
	568	}
	569	if (j >= num_keys)
	570	fatal("percent_expand: unknown key %%%c", *string);
	571	}
	572	return (xstrdup(buf));
	573	#undef EXPAND_MAX_KEYS
	574	}
	575
ea067773	576	/*
	577	* Read an entire line from a public key file into a static buffer, discarding
	578	* lines that exceed the buffer size. Returns 0 on success, -1 on failure.
	579	*/
	580	int
	581	read_keyfile_line(FILE f, const char filename, char *buf, size_t bufsz,
41feb690	582	u_long *lineno)
ea067773	583	{
	584	while (fgets(buf, bufsz, f) != NULL) {
	585	(*lineno)++;
	586	if (buf[strlen(buf) - 1] == '\n' \|\| feof(f)) {
	587	return 0;
	588	} else {
41feb690	589	debug("%s: %s line %lu exceeds size limit", __func__,
41feb690	590	filename, *lineno);
ea067773	591	/* discard remainder of line */
f8cc7664	592	while (fgetc(f) != '\n' && !feof(f))
ea067773	593	; /* nothing */
	594	}
	595	}
	596	return -1;
	597	}
ef07103c	598
d20f3c9e	599	int
a4f24bf8	600	tun_open(int tun, int mode)
d20f3c9e	601	{
6306853a	602	#if defined(CUSTOM_SYS_TUN_OPEN)
6306853a	603	return (sys_tun_open(tun, mode));
0f6cb079	604	#elif defined(SSH_TUN_OPENBSD)
a4f24bf8	605	struct ifreq ifr;
d20f3c9e	606	char name[100];
a4f24bf8	607	int fd = -1, sock;
d20f3c9e	608
a4f24bf8	609	/* Open the tunnel device */
a4f24bf8	610	if (tun <= SSH_TUNID_MAX) {
d20f3c9e	611	snprintf(name, sizeof(name), "/dev/tun%d", tun);
a4f24bf8	612	fd = open(name, O_RDWR);
	613	} else if (tun == SSH_TUNID_ANY) {
	614	for (tun = 100; tun >= 0; tun--) {
	615	snprintf(name, sizeof(name), "/dev/tun%d", tun);
	616	if ((fd = open(name, O_RDWR)) >= 0)
	617	break;
d20f3c9e	618	}
d20f3c9e	619	} else {
81c042a3	620	debug("%s: invalid tunnel %u", __func__, tun);
a4f24bf8	621	return (-1);
	622	}
	623
	624	if (fd < 0) {
	625	debug("%s: %s open failed: %s", __func__, name, strerror(errno));
	626	return (-1);
	627	}
	628
	629	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
	630
	631	/* Set the tunnel device operation mode */
	632	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
	633	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
	634	goto failed;
	635
	636	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
	637	goto failed;
b1b65311	638
	639	/* Set interface mode */
	640	ifr.ifr_flags &= ~IFF_UP;
	641	if (mode == SSH_TUNMODE_ETHERNET)
a4f24bf8	642	ifr.ifr_flags \|= IFF_LINK0;
b1b65311	643	else
	644	ifr.ifr_flags &= ~IFF_LINK0;
	645	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	646	goto failed;
	647
	648	/* Bring interface up */
a4f24bf8	649	ifr.ifr_flags \|= IFF_UP;
	650	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	651	goto failed;
	652
	653	close(sock);
	654	return (fd);
	655
	656	failed:
	657	if (fd >= 0)
	658	close(fd);
	659	if (sock >= 0)
	660	close(sock);
	661	debug("%s: failed to set %s mode %d: %s", __func__, name,
	662	mode, strerror(errno));
d20f3c9e	663	return (-1);
6306853a	664	#else
	665	error("Tunnel interfaces are not supported on this platform");
	666	return (-1);
	667	#endif
d20f3c9e	668	}
d20f3c9e	669
fd6168c1	670	void
	671	sanitise_stdfd(void)
	672	{
db382686	673	int nullfd, dupfd;
fd6168c1	674
db382686	675	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
fd6168c1	676	fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
	677	exit(1);
	678	}
db382686	679	while (++dupfd <= 2) {
	680	/* Only clobber closed fds */
	681	if (fcntl(dupfd, F_GETFL, 0) >= 0)
	682	continue;
	683	if (dup2(nullfd, dupfd) == -1) {
fd6168c1	684	fprintf(stderr, "dup2: %s", strerror(errno));
	685	exit(1);
	686	}
fd6168c1	687	}
	688	if (nullfd > 2)
	689	close(nullfd);
	690	}
	691
ef07103c	692	char *
	693	tohex(const u_char *d, u_int l)
	694	{
	695	char b[3], *r;
	696	u_int i, hl;
	697
	698	hl = l * 2 + 1;
52e3daed	699	r = xcalloc(1, hl);
ef07103c	700	for (i = 0; i < l; i++) {
	701	snprintf(b, sizeof(b), "%02x", d[i]);
	702	strlcat(r, b, hl);
	703	}
	704	return (r);
	705	}
	706