[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"
RCSID("$OpenBSD: misc.c,v 1.44 2006/02/08 12:32:49 stevesk Exp $");
 
#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"

/* 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 "=");
	if (*s == NULL)
		return (old);

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

	*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 = xmalloc(sizeof(*copy));

	memset(copy, 0, 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--;
		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 = xmalloc(hl);
	*r = '\0';
	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"
6425cf65	27	RCSID("$OpenBSD: misc.c,v 1.44 2006/02/08 12:32:49 stevesk Exp $");
	28
	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. */
	129	#define WHITESPACE " \t\r\n"
	130
255cabd9	131	/* return next token in configuration line */
6d24277f	132	char *
	133	strdelim(char **s)
	134	{
	135	char *old;
	136	int wspace = 0;
	137
	138	if (*s == NULL)
	139	return NULL;
	140
	141	old = *s;
	142
	143	s = strpbrk(s, WHITESPACE "=");
	144	if (*s == NULL)
	145	return (old);
	146
	147	/* Allow only one '=' to be skipped */
	148	if (*s[0] == '=')
	149	wspace = 1;
	150	*s[0] = '\0';
	151
	152	s += strspn(s + 1, WHITESPACE) + 1;
	153	if (*s[0] == '=' && !wspace)
	154	s += strspn(s + 1, WHITESPACE) + 1;
	155
	156	return (old);
	157	}
1aa00dcb	158
3b1a83df	159	struct passwd *
	160	pwcopy(struct passwd *pw)
	161	{
	162	struct passwd copy = xmalloc(sizeof(copy));
5649fbbe	163
3b1a83df	164	memset(copy, 0, sizeof(*copy));
	165	copy->pw_name = xstrdup(pw->pw_name);
	166	copy->pw_passwd = xstrdup(pw->pw_passwd);
5649fbbe	167	copy->pw_gecos = xstrdup(pw->pw_gecos);
3b1a83df	168	copy->pw_uid = pw->pw_uid;
3b1a83df	169	copy->pw_gid = pw->pw_gid;
7751d4eb	170	#ifdef HAVE_PW_EXPIRE_IN_PASSWD
c4d49b85	171	copy->pw_expire = pw->pw_expire;
7751d4eb	172	#endif
7751d4eb	173	#ifdef HAVE_PW_CHANGE_IN_PASSWD
c4d49b85	174	copy->pw_change = pw->pw_change;
7751d4eb	175	#endif
2605addd	176	#ifdef HAVE_PW_CLASS_IN_PASSWD
3b1a83df	177	copy->pw_class = xstrdup(pw->pw_class);
2605addd	178	#endif
3b1a83df	179	copy->pw_dir = xstrdup(pw->pw_dir);
	180	copy->pw_shell = xstrdup(pw->pw_shell);
	181	return copy;
	182	}
	183
255cabd9	184	/*
	185	* Convert ASCII string to TCP/IP port number.
	186	* Port must be >0 and <=65535.
	187	* Return 0 if invalid.
	188	*/
	189	int
	190	a2port(const char *s)
2d2a2c65	191	{
	192	long port;
	193	char *endp;
	194
	195	errno = 0;
	196	port = strtol(s, &endp, 0);
	197	if (s == endp \|\| *endp != '\0' \|\|
	198	(errno == ERANGE && (port == LONG_MIN \|\| port == LONG_MAX)) \|\|
	199	port <= 0 \|\| port > 65535)
	200	return 0;
	201
	202	return port;
	203	}
	204
d20f3c9e	205	int
	206	a2tun(const char s, int remote)
	207	{
	208	const char *errstr = NULL;
	209	char sp, ep;
	210	int tun;
	211
	212	if (remote != NULL) {
a4f24bf8	213	*remote = SSH_TUNID_ANY;
d20f3c9e	214	sp = xstrdup(s);
	215	if ((ep = strchr(sp, ':')) == NULL) {
	216	xfree(sp);
	217	return (a2tun(s, NULL));
	218	}
	219	ep[0] = '\0'; ep++;
	220	*remote = a2tun(ep, NULL);
	221	tun = a2tun(sp, NULL);
	222	xfree(sp);
a4f24bf8	223	return (remote == SSH_TUNID_ERR ? remote : tun);
d20f3c9e	224	}
	225
	226	if (strcasecmp(s, "any") == 0)
a4f24bf8	227	return (SSH_TUNID_ANY);
d20f3c9e	228
a4f24bf8	229	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
	230	if (errstr != NULL)
	231	return (SSH_TUNID_ERR);
d20f3c9e	232
	233	return (tun);
	234	}
	235
e2b1fb42	236	#define SECONDS 1
	237	#define MINUTES (SECONDS * 60)
	238	#define HOURS (MINUTES * 60)
	239	#define DAYS (HOURS * 24)
	240	#define WEEKS (DAYS * 7)
	241
255cabd9	242	/*
	243	* Convert a time string into seconds; format is
	244	* a sequence of:
	245	* time[qualifier]
	246	*
	247	* Valid time qualifiers are:
	248	* <none> seconds
	249	* s\|S seconds
	250	* m\|M minutes
	251	* h\|H hours
	252	* d\|D days
	253	* w\|W weeks
	254	*
	255	* Examples:
	256	* 90m 90 minutes
	257	* 1h30m 90 minutes
	258	* 2d 2 days
	259	* 1w 1 week
	260	*
	261	* Return -1 if time string is invalid.
	262	*/
	263	long
	264	convtime(const char *s)
e2b1fb42	265	{
	266	long total, secs;
	267	const char *p;
	268	char *endp;
	269
	270	errno = 0;
	271	total = 0;
	272	p = s;
	273
	274	if (p == NULL \|\| *p == '\0')
	275	return -1;
	276
	277	while (*p) {
	278	secs = strtol(p, &endp, 10);
	279	if (p == endp \|\|
	280	(errno == ERANGE && (secs == LONG_MIN \|\| secs == LONG_MAX)) \|\|
	281	secs < 0)
	282	return -1;
	283
	284	switch (*endp++) {
	285	case '\0':
	286	endp--;
	287	case 's':
	288	case 'S':
	289	break;
	290	case 'm':
	291	case 'M':
	292	secs *= MINUTES;
	293	break;
	294	case 'h':
	295	case 'H':
	296	secs *= HOURS;
	297	break;
	298	case 'd':
	299	case 'D':
	300	secs *= DAYS;
	301	break;
	302	case 'w':
	303	case 'W':
	304	secs *= WEEKS;
	305	break;
	306	default:
	307	return -1;
	308	}
	309	total += secs;
	310	if (total < 0)
	311	return -1;
	312	p = endp;
	313	}
	314
	315	return total;
	316	}
	317
3867aa0a	318	/*
	319	* Search for next delimiter between hostnames/addresses and ports.
	320	* Argument may be modified (for termination).
	321	* Returns *cp if parsing succeeds.
	322	* *cp is set to the start of the next delimiter, if one was found.
	323	* If this is the last field, *cp is set to NULL.
	324	*/
	325	char *
	326	hpdelim(char **cp)
	327	{
	328	char s, old;
	329
	330	if (cp == NULL \|\| *cp == NULL)
	331	return NULL;
	332
	333	old = s = *cp;
	334	if (*s == '[') {
	335	if ((s = strchr(s, ']')) == NULL)
	336	return NULL;
	337	else
	338	s++;
	339	} else if ((s = strpbrk(s, ":/")) == NULL)
	340	s = cp + strlen(cp); /* skip to end (see first case below) */
	341
	342	switch (*s) {
	343	case '\0':
	344	cp = NULL; / no more fields*/
	345	break;
f8cc7664	346
3867aa0a	347	case ':':
	348	case '/':
	349	s = '\0'; / terminate */
	350	*cp = s + 1;
	351	break;
f8cc7664	352
3867aa0a	353	default:
	354	return NULL;
	355	}
	356
	357	return old;
	358	}
	359
1fcde3fe	360	char *
	361	cleanhostname(char *host)
	362	{
	363	if (*host == '[' && host[strlen(host) - 1] == ']') {
	364	host[strlen(host) - 1] = '\0';
	365	return (host + 1);
	366	} else
	367	return host;
	368	}
	369
	370	char *
	371	colon(char *cp)
	372	{
	373	int flag = 0;
	374
	375	if (cp == ':') / Leading colon is part of file name. */
	376	return (0);
	377	if (*cp == '[')
	378	flag = 1;
	379
	380	for (; *cp; ++cp) {
	381	if (cp == '@' && (cp+1) == '[')
	382	flag = 1;
	383	if (cp == ']' && (cp+1) == ':' && flag)
	384	return (cp+1);
	385	if (*cp == ':' && !flag)
	386	return (cp);
	387	if (*cp == '/')
	388	return (0);
	389	}
	390	return (0);
	391	}
	392
255cabd9	393	/* function to assist building execv() arguments */
8a624ebf	394	void
	395	addargs(arglist args, char fmt, ...)
	396	{
	397	va_list ap;
4116f5c0	398	char *cp;
9a995072	399	u_int nalloc;
4116f5c0	400	int r;
8a624ebf	401
8a624ebf	402	va_start(ap, fmt);
4116f5c0	403	r = vasprintf(&cp, fmt, ap);
8a624ebf	404	va_end(ap);
4116f5c0	405	if (r == -1)
4116f5c0	406	fatal("addargs: argument too long");
8a624ebf	407
c46e584f	408	nalloc = args->nalloc;
8a624ebf	409	if (args->list == NULL) {
c46e584f	410	nalloc = 32;
8a624ebf	411	args->num = 0;
c46e584f	412	} else if (args->num+2 >= nalloc)
c46e584f	413	nalloc *= 2;
8a624ebf	414
c46e584f	415	args->list = xrealloc(args->list, nalloc * sizeof(char *));
c46e584f	416	args->nalloc = nalloc;
4116f5c0	417	args->list[args->num++] = cp;
8a624ebf	418	args->list[args->num] = NULL;
8a624ebf	419	}
ea067773	420
4116f5c0	421	void
	422	replacearg(arglist args, u_int which, char fmt, ...)
	423	{
	424	va_list ap;
	425	char *cp;
	426	int r;
	427
	428	va_start(ap, fmt);
	429	r = vasprintf(&cp, fmt, ap);
	430	va_end(ap);
	431	if (r == -1)
	432	fatal("replacearg: argument too long");
	433
	434	if (which >= args->num)
	435	fatal("replacearg: tried to replace invalid arg %d >= %d",
	436	which, args->num);
	437	xfree(args->list[which]);
	438	args->list[which] = cp;
	439	}
	440
	441	void
	442	freeargs(arglist *args)
	443	{
	444	u_int i;
	445
	446	if (args->list != NULL) {
	447	for (i = 0; i < args->num; i++)
	448	xfree(args->list[i]);
	449	xfree(args->list);
	450	args->nalloc = args->num = 0;
	451	args->list = NULL;
	452	}
	453	}
	454
49e71137	455	/*
	456	* Expands tildes in the file name. Returns data allocated by xmalloc.
	457	* Warning: this calls getpw*.
	458	*/
	459	char *
	460	tilde_expand_filename(const char *filename, uid_t uid)
	461	{
	462	const char *path;
	463	char user[128], ret[MAXPATHLEN];
	464	struct passwd *pw;
2ceb8101	465	u_int len, slash;
49e71137	466
	467	if (*filename != '~')
	468	return (xstrdup(filename));
	469	filename++;
	470
	471	path = strchr(filename, '/');
	472	if (path != NULL && path > filename) { /* ~user/path */
2ceb8101	473	slash = path - filename;
2ceb8101	474	if (slash > sizeof(user) - 1)
49e71137	475	fatal("tilde_expand_filename: ~username too long");
2ceb8101	476	memcpy(user, filename, slash);
2ceb8101	477	user[slash] = '\0';
49e71137	478	if ((pw = getpwnam(user)) == NULL)
	479	fatal("tilde_expand_filename: No such user %s", user);
	480	} else if ((pw = getpwuid(uid)) == NULL) /* ~/path */
	481	fatal("tilde_expand_filename: No such uid %d", uid);
	482
	483	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
	484	fatal("tilde_expand_filename: Path too long");
	485
	486	/* Make sure directory has a trailing '/' */
	487	len = strlen(pw->pw_dir);
	488	if ((len == 0 \|\| pw->pw_dir[len - 1] != '/') &&
	489	strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
	490	fatal("tilde_expand_filename: Path too long");
	491
	492	/* Skip leading '/' from specified path */
	493	if (path != NULL)
	494	filename = path + 1;
	495	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
	496	fatal("tilde_expand_filename: Path too long");
	497
	498	return (xstrdup(ret));
	499	}
	500
a980cbd7	501	/*
	502	* Expand a string with a set of %[char] escapes. A number of escapes may be
	503	* specified as (char escape_chars, char replacement) pairs. The list must
6381acf0	504	* be terminated by a NULL escape_char. Returns replaced string in memory
a980cbd7	505	* allocated by xmalloc.
	506	*/
	507	char *
	508	percent_expand(const char *string, ...)
	509	{
	510	#define EXPAND_MAX_KEYS 16
	511	struct {
	512	const char *key;
	513	const char *repl;
	514	} keys[EXPAND_MAX_KEYS];
2ceb8101	515	u_int num_keys, i, j;
a980cbd7	516	char buf[4096];
	517	va_list ap;
	518
	519	/* Gather keys */
	520	va_start(ap, string);
	521	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
	522	keys[num_keys].key = va_arg(ap, char *);
	523	if (keys[num_keys].key == NULL)
	524	break;
	525	keys[num_keys].repl = va_arg(ap, char *);
	526	if (keys[num_keys].repl == NULL)
	527	fatal("percent_expand: NULL replacement");
	528	}
	529	va_end(ap);
	530
	531	if (num_keys >= EXPAND_MAX_KEYS)
	532	fatal("percent_expand: too many keys");
	533
	534	/* Expand string */
	535	*buf = '\0';
	536	for (i = 0; *string != '\0'; string++) {
	537	if (*string != '%') {
	538	append:
	539	buf[i++] = *string;
	540	if (i >= sizeof(buf))
	541	fatal("percent_expand: string too long");
	542	buf[i] = '\0';
	543	continue;
	544	}
	545	string++;
	546	if (*string == '%')
	547	goto append;
	548	for (j = 0; j < num_keys; j++) {
	549	if (strchr(keys[j].key, *string) != NULL) {
	550	i = strlcat(buf, keys[j].repl, sizeof(buf));
	551	if (i >= sizeof(buf))
	552	fatal("percent_expand: string too long");
	553	break;
	554	}
	555	}
	556	if (j >= num_keys)
	557	fatal("percent_expand: unknown key %%%c", *string);
	558	}
	559	return (xstrdup(buf));
	560	#undef EXPAND_MAX_KEYS
	561	}
	562
ea067773	563	/*
	564	* Read an entire line from a public key file into a static buffer, discarding
	565	* lines that exceed the buffer size. Returns 0 on success, -1 on failure.
	566	*/
	567	int
	568	read_keyfile_line(FILE f, const char filename, char *buf, size_t bufsz,
41feb690	569	u_long *lineno)
ea067773	570	{
	571	while (fgets(buf, bufsz, f) != NULL) {
	572	(*lineno)++;
	573	if (buf[strlen(buf) - 1] == '\n' \|\| feof(f)) {
	574	return 0;
	575	} else {
41feb690	576	debug("%s: %s line %lu exceeds size limit", __func__,
41feb690	577	filename, *lineno);
ea067773	578	/* discard remainder of line */
f8cc7664	579	while (fgetc(f) != '\n' && !feof(f))
ea067773	580	; /* nothing */
	581	}
	582	}
	583	return -1;
	584	}
ef07103c	585
d20f3c9e	586	int
a4f24bf8	587	tun_open(int tun, int mode)
d20f3c9e	588	{
6306853a	589	#if defined(CUSTOM_SYS_TUN_OPEN)
6306853a	590	return (sys_tun_open(tun, mode));
0f6cb079	591	#elif defined(SSH_TUN_OPENBSD)
a4f24bf8	592	struct ifreq ifr;
d20f3c9e	593	char name[100];
a4f24bf8	594	int fd = -1, sock;
d20f3c9e	595
a4f24bf8	596	/* Open the tunnel device */
a4f24bf8	597	if (tun <= SSH_TUNID_MAX) {
d20f3c9e	598	snprintf(name, sizeof(name), "/dev/tun%d", tun);
a4f24bf8	599	fd = open(name, O_RDWR);
	600	} else if (tun == SSH_TUNID_ANY) {
	601	for (tun = 100; tun >= 0; tun--) {
	602	snprintf(name, sizeof(name), "/dev/tun%d", tun);
	603	if ((fd = open(name, O_RDWR)) >= 0)
	604	break;
d20f3c9e	605	}
d20f3c9e	606	} else {
81c042a3	607	debug("%s: invalid tunnel %u", __func__, tun);
a4f24bf8	608	return (-1);
	609	}
	610
	611	if (fd < 0) {
	612	debug("%s: %s open failed: %s", __func__, name, strerror(errno));
	613	return (-1);
	614	}
	615
	616	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
	617
	618	/* Set the tunnel device operation mode */
	619	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
	620	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
	621	goto failed;
	622
	623	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
	624	goto failed;
b1b65311	625
	626	/* Set interface mode */
	627	ifr.ifr_flags &= ~IFF_UP;
	628	if (mode == SSH_TUNMODE_ETHERNET)
a4f24bf8	629	ifr.ifr_flags \|= IFF_LINK0;
b1b65311	630	else
	631	ifr.ifr_flags &= ~IFF_LINK0;
	632	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	633	goto failed;
	634
	635	/* Bring interface up */
a4f24bf8	636	ifr.ifr_flags \|= IFF_UP;
	637	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	638	goto failed;
	639
	640	close(sock);
	641	return (fd);
	642
	643	failed:
	644	if (fd >= 0)
	645	close(fd);
	646	if (sock >= 0)
	647	close(sock);
	648	debug("%s: failed to set %s mode %d: %s", __func__, name,
	649	mode, strerror(errno));
d20f3c9e	650	return (-1);
6306853a	651	#else
	652	error("Tunnel interfaces are not supported on this platform");
	653	return (-1);
	654	#endif
d20f3c9e	655	}
d20f3c9e	656
fd6168c1	657	void
	658	sanitise_stdfd(void)
	659	{
db382686	660	int nullfd, dupfd;
fd6168c1	661
db382686	662	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
fd6168c1	663	fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
	664	exit(1);
	665	}
db382686	666	while (++dupfd <= 2) {
	667	/* Only clobber closed fds */
	668	if (fcntl(dupfd, F_GETFL, 0) >= 0)
	669	continue;
	670	if (dup2(nullfd, dupfd) == -1) {
fd6168c1	671	fprintf(stderr, "dup2: %s", strerror(errno));
	672	exit(1);
	673	}
fd6168c1	674	}
	675	if (nullfd > 2)
	676	close(nullfd);
	677	}
	678
ef07103c	679	char *
	680	tohex(const u_char *d, u_int l)
	681	{
	682	char b[3], *r;
	683	u_int i, hl;
	684
	685	hl = l * 2 + 1;
	686	r = xmalloc(hl);
	687	*r = '\0';
	688	for (i = 0; i < l; i++) {
	689	snprintf(b, sizeof(b), "%02x", d[i]);
	690	strlcat(r, b, hl);
	691	}
	692	return (r);
	693	}
	694