[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 1.45 2006/02/10 00:27:13 stevesk Exp $");

#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"

/* 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"
bd7c69ea	27	RCSID("$OpenBSD: misc.c,v 1.45 2006/02/10 00:27:13 stevesk Exp $");
	28
	29	#include <sys/ioctl.h>
6425cf65	30	#include <netinet/tcp.h>
a75f5360	31	#ifdef HAVE_PATHS_H
6f61e0ec	32	# include <paths.h>
a75f5360	33	#endif
1f1fbbd8	34	#ifdef SSH_TUN_OPENBSD
	35	#include <net/if.h>
	36	#endif
6d24277f	37
1aa00dcb	38	#include "misc.h"
42f11eb2	39	#include "log.h"
4ab21f86	40	#include "xmalloc.h"
6d24277f	41
255cabd9	42	/* remove newline at end of string */
6d24277f	43	char *
	44	chop(char *s)
	45	{
	46	char *t = s;
	47	while (*t) {
6aacefa7	48	if (t == '\n' \|\| t == '\r') {
6d24277f	49	*t = '\0';
	50	return s;
	51	}
	52	t++;
	53	}
	54	return s;
	55
	56	}
	57
255cabd9	58	/* set/unset filedescriptor to non-blocking */
170694d7	59	int
6d24277f	60	set_nonblock(int fd)
	61	{
	62	int val;
89aa792b	63
6d24277f	64	val = fcntl(fd, F_GETFL, 0);
	65	if (val < 0) {
	66	error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
170694d7	67	return (-1);
6d24277f	68	}
a22aff1f	69	if (val & O_NONBLOCK) {
170694d7	70	debug3("fd %d is O_NONBLOCK", fd);
170694d7	71	return (0);
a22aff1f	72	}
45c42d58	73	debug2("fd %d setting O_NONBLOCK", fd);
6d24277f	74	val \|= O_NONBLOCK;
170694d7	75	if (fcntl(fd, F_SETFL, val) == -1) {
	76	debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
	77	strerror(errno));
	78	return (-1);
	79	}
	80	return (0);
6d24277f	81	}
6d24277f	82
170694d7	83	int
89aa792b	84	unset_nonblock(int fd)
	85	{
	86	int val;
	87
	88	val = fcntl(fd, F_GETFL, 0);
	89	if (val < 0) {
	90	error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
170694d7	91	return (-1);
89aa792b	92	}
89aa792b	93	if (!(val & O_NONBLOCK)) {
170694d7	94	debug3("fd %d is not O_NONBLOCK", fd);
170694d7	95	return (0);
89aa792b	96	}
e04e7a19	97	debug("fd %d clearing O_NONBLOCK", fd);
89aa792b	98	val &= ~O_NONBLOCK;
170694d7	99	if (fcntl(fd, F_SETFL, val) == -1) {
170694d7	100	debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
c92ec40b	101	fd, strerror(errno));
170694d7	102	return (-1);
	103	}
	104	return (0);
89aa792b	105	}
89aa792b	106
bcc0381e	107	/* disable nagle on socket */
	108	void
	109	set_nodelay(int fd)
	110	{
3c05447a	111	int opt;
3c05447a	112	socklen_t optlen;
bcc0381e	113
811a6342	114	optlen = sizeof opt;
811a6342	115	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
f7fb35fe	116	debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
811a6342	117	return;
	118	}
	119	if (opt == 1) {
	120	debug2("fd %d is TCP_NODELAY", fd);
	121	return;
	122	}
	123	opt = 1;
6226a8f8	124	debug2("fd %d setting TCP_NODELAY", fd);
811a6342	125	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
bcc0381e	126	error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
	127	}
	128
6d24277f	129	/* Characters considered whitespace in strsep calls. */
	130	#define WHITESPACE " \t\r\n"
	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
	144	s = strpbrk(s, WHITESPACE "=");
	145	if (*s == NULL)
	146	return (old);
	147
	148	/* Allow only one '=' to be skipped */
	149	if (*s[0] == '=')
	150	wspace = 1;
	151	*s[0] = '\0';
	152
	153	s += strspn(s + 1, WHITESPACE) + 1;
	154	if (*s[0] == '=' && !wspace)
	155	s += strspn(s + 1, WHITESPACE) + 1;
	156
	157	return (old);
	158	}
1aa00dcb	159
3b1a83df	160	struct passwd *
	161	pwcopy(struct passwd *pw)
	162	{
	163	struct passwd copy = xmalloc(sizeof(copy));
5649fbbe	164
3b1a83df	165	memset(copy, 0, sizeof(*copy));
	166	copy->pw_name = xstrdup(pw->pw_name);
	167	copy->pw_passwd = xstrdup(pw->pw_passwd);
5649fbbe	168	copy->pw_gecos = xstrdup(pw->pw_gecos);
3b1a83df	169	copy->pw_uid = pw->pw_uid;
3b1a83df	170	copy->pw_gid = pw->pw_gid;
7751d4eb	171	#ifdef HAVE_PW_EXPIRE_IN_PASSWD
c4d49b85	172	copy->pw_expire = pw->pw_expire;
7751d4eb	173	#endif
7751d4eb	174	#ifdef HAVE_PW_CHANGE_IN_PASSWD
c4d49b85	175	copy->pw_change = pw->pw_change;
7751d4eb	176	#endif
2605addd	177	#ifdef HAVE_PW_CLASS_IN_PASSWD
3b1a83df	178	copy->pw_class = xstrdup(pw->pw_class);
2605addd	179	#endif
3b1a83df	180	copy->pw_dir = xstrdup(pw->pw_dir);
	181	copy->pw_shell = xstrdup(pw->pw_shell);
	182	return copy;
	183	}
	184
255cabd9	185	/*
	186	* Convert ASCII string to TCP/IP port number.
	187	* Port must be >0 and <=65535.
	188	* Return 0 if invalid.
	189	*/
	190	int
	191	a2port(const char *s)
2d2a2c65	192	{
	193	long port;
	194	char *endp;
	195
	196	errno = 0;
	197	port = strtol(s, &endp, 0);
	198	if (s == endp \|\| *endp != '\0' \|\|
	199	(errno == ERANGE && (port == LONG_MIN \|\| port == LONG_MAX)) \|\|
	200	port <= 0 \|\| port > 65535)
	201	return 0;
	202
	203	return port;
	204	}
	205
d20f3c9e	206	int
	207	a2tun(const char s, int remote)
	208	{
	209	const char *errstr = NULL;
	210	char sp, ep;
	211	int tun;
	212
	213	if (remote != NULL) {
a4f24bf8	214	*remote = SSH_TUNID_ANY;
d20f3c9e	215	sp = xstrdup(s);
	216	if ((ep = strchr(sp, ':')) == NULL) {
	217	xfree(sp);
	218	return (a2tun(s, NULL));
	219	}
	220	ep[0] = '\0'; ep++;
	221	*remote = a2tun(ep, NULL);
	222	tun = a2tun(sp, NULL);
	223	xfree(sp);
a4f24bf8	224	return (remote == SSH_TUNID_ERR ? remote : tun);
d20f3c9e	225	}
	226
	227	if (strcasecmp(s, "any") == 0)
a4f24bf8	228	return (SSH_TUNID_ANY);
d20f3c9e	229
a4f24bf8	230	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
	231	if (errstr != NULL)
	232	return (SSH_TUNID_ERR);
d20f3c9e	233
	234	return (tun);
	235	}
	236
e2b1fb42	237	#define SECONDS 1
	238	#define MINUTES (SECONDS * 60)
	239	#define HOURS (MINUTES * 60)
	240	#define DAYS (HOURS * 24)
	241	#define WEEKS (DAYS * 7)
	242
255cabd9	243	/*
	244	* Convert a time string into seconds; format is
	245	* a sequence of:
	246	* time[qualifier]
	247	*
	248	* Valid time qualifiers are:
	249	* <none> seconds
	250	* s\|S seconds
	251	* m\|M minutes
	252	* h\|H hours
	253	* d\|D days
	254	* w\|W weeks
	255	*
	256	* Examples:
	257	* 90m 90 minutes
	258	* 1h30m 90 minutes
	259	* 2d 2 days
	260	* 1w 1 week
	261	*
	262	* Return -1 if time string is invalid.
	263	*/
	264	long
	265	convtime(const char *s)
e2b1fb42	266	{
	267	long total, secs;
	268	const char *p;
	269	char *endp;
	270
	271	errno = 0;
	272	total = 0;
	273	p = s;
	274
	275	if (p == NULL \|\| *p == '\0')
	276	return -1;
	277
	278	while (*p) {
	279	secs = strtol(p, &endp, 10);
	280	if (p == endp \|\|
	281	(errno == ERANGE && (secs == LONG_MIN \|\| secs == LONG_MAX)) \|\|
	282	secs < 0)
	283	return -1;
	284
	285	switch (*endp++) {
	286	case '\0':
	287	endp--;
	288	case 's':
	289	case 'S':
	290	break;
	291	case 'm':
	292	case 'M':
	293	secs *= MINUTES;
	294	break;
	295	case 'h':
	296	case 'H':
	297	secs *= HOURS;
	298	break;
	299	case 'd':
	300	case 'D':
	301	secs *= DAYS;
	302	break;
	303	case 'w':
	304	case 'W':
	305	secs *= WEEKS;
	306	break;
	307	default:
	308	return -1;
	309	}
	310	total += secs;
	311	if (total < 0)
	312	return -1;
	313	p = endp;
	314	}
	315
	316	return total;
	317	}
	318
3867aa0a	319	/*
	320	* Search for next delimiter between hostnames/addresses and ports.
	321	* Argument may be modified (for termination).
	322	* Returns *cp if parsing succeeds.
	323	* *cp is set to the start of the next delimiter, if one was found.
	324	* If this is the last field, *cp is set to NULL.
	325	*/
	326	char *
	327	hpdelim(char **cp)
	328	{
	329	char s, old;
	330
	331	if (cp == NULL \|\| *cp == NULL)
	332	return NULL;
	333
	334	old = s = *cp;
	335	if (*s == '[') {
	336	if ((s = strchr(s, ']')) == NULL)
	337	return NULL;
	338	else
	339	s++;
	340	} else if ((s = strpbrk(s, ":/")) == NULL)
	341	s = cp + strlen(cp); /* skip to end (see first case below) */
	342
	343	switch (*s) {
	344	case '\0':
	345	cp = NULL; / no more fields*/
	346	break;
f8cc7664	347
3867aa0a	348	case ':':
	349	case '/':
	350	s = '\0'; / terminate */
	351	*cp = s + 1;
	352	break;
f8cc7664	353
3867aa0a	354	default:
	355	return NULL;
	356	}
	357
	358	return old;
	359	}
	360
1fcde3fe	361	char *
	362	cleanhostname(char *host)
	363	{
	364	if (*host == '[' && host[strlen(host) - 1] == ']') {
	365	host[strlen(host) - 1] = '\0';
	366	return (host + 1);
	367	} else
	368	return host;
	369	}
	370
	371	char *
	372	colon(char *cp)
	373	{
	374	int flag = 0;
	375
	376	if (cp == ':') / Leading colon is part of file name. */
	377	return (0);
	378	if (*cp == '[')
	379	flag = 1;
	380
	381	for (; *cp; ++cp) {
	382	if (cp == '@' && (cp+1) == '[')
	383	flag = 1;
	384	if (cp == ']' && (cp+1) == ':' && flag)
	385	return (cp+1);
	386	if (*cp == ':' && !flag)
	387	return (cp);
	388	if (*cp == '/')
	389	return (0);
	390	}
	391	return (0);
	392	}
	393
255cabd9	394	/* function to assist building execv() arguments */
8a624ebf	395	void
	396	addargs(arglist args, char fmt, ...)
	397	{
	398	va_list ap;
4116f5c0	399	char *cp;
9a995072	400	u_int nalloc;
4116f5c0	401	int r;
8a624ebf	402
8a624ebf	403	va_start(ap, fmt);
4116f5c0	404	r = vasprintf(&cp, fmt, ap);
8a624ebf	405	va_end(ap);
4116f5c0	406	if (r == -1)
4116f5c0	407	fatal("addargs: argument too long");
8a624ebf	408
c46e584f	409	nalloc = args->nalloc;
8a624ebf	410	if (args->list == NULL) {
c46e584f	411	nalloc = 32;
8a624ebf	412	args->num = 0;
c46e584f	413	} else if (args->num+2 >= nalloc)
c46e584f	414	nalloc *= 2;
8a624ebf	415
c46e584f	416	args->list = xrealloc(args->list, nalloc * sizeof(char *));
c46e584f	417	args->nalloc = nalloc;
4116f5c0	418	args->list[args->num++] = cp;
8a624ebf	419	args->list[args->num] = NULL;
8a624ebf	420	}
ea067773	421
4116f5c0	422	void
	423	replacearg(arglist args, u_int which, char fmt, ...)
	424	{
	425	va_list ap;
	426	char *cp;
	427	int r;
	428
	429	va_start(ap, fmt);
	430	r = vasprintf(&cp, fmt, ap);
	431	va_end(ap);
	432	if (r == -1)
	433	fatal("replacearg: argument too long");
	434
	435	if (which >= args->num)
	436	fatal("replacearg: tried to replace invalid arg %d >= %d",
	437	which, args->num);
	438	xfree(args->list[which]);
	439	args->list[which] = cp;
	440	}
	441
	442	void
	443	freeargs(arglist *args)
	444	{
	445	u_int i;
	446
	447	if (args->list != NULL) {
	448	for (i = 0; i < args->num; i++)
	449	xfree(args->list[i]);
	450	xfree(args->list);
	451	args->nalloc = args->num = 0;
	452	args->list = NULL;
	453	}
	454	}
	455
49e71137	456	/*
	457	* Expands tildes in the file name. Returns data allocated by xmalloc.
	458	* Warning: this calls getpw*.
	459	*/
	460	char *
	461	tilde_expand_filename(const char *filename, uid_t uid)
	462	{
	463	const char *path;
	464	char user[128], ret[MAXPATHLEN];
	465	struct passwd *pw;
2ceb8101	466	u_int len, slash;
49e71137	467
	468	if (*filename != '~')
	469	return (xstrdup(filename));
	470	filename++;
	471
	472	path = strchr(filename, '/');
	473	if (path != NULL && path > filename) { /* ~user/path */
2ceb8101	474	slash = path - filename;
2ceb8101	475	if (slash > sizeof(user) - 1)
49e71137	476	fatal("tilde_expand_filename: ~username too long");
2ceb8101	477	memcpy(user, filename, slash);
2ceb8101	478	user[slash] = '\0';
49e71137	479	if ((pw = getpwnam(user)) == NULL)
	480	fatal("tilde_expand_filename: No such user %s", user);
	481	} else if ((pw = getpwuid(uid)) == NULL) /* ~/path */
	482	fatal("tilde_expand_filename: No such uid %d", uid);
	483
	484	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
	485	fatal("tilde_expand_filename: Path too long");
	486
	487	/* Make sure directory has a trailing '/' */
	488	len = strlen(pw->pw_dir);
	489	if ((len == 0 \|\| pw->pw_dir[len - 1] != '/') &&
	490	strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
	491	fatal("tilde_expand_filename: Path too long");
	492
	493	/* Skip leading '/' from specified path */
	494	if (path != NULL)
	495	filename = path + 1;
	496	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
	497	fatal("tilde_expand_filename: Path too long");
	498
	499	return (xstrdup(ret));
	500	}
	501
a980cbd7	502	/*
	503	* Expand a string with a set of %[char] escapes. A number of escapes may be
	504	* specified as (char escape_chars, char replacement) pairs. The list must
6381acf0	505	* be terminated by a NULL escape_char. Returns replaced string in memory
a980cbd7	506	* allocated by xmalloc.
	507	*/
	508	char *
	509	percent_expand(const char *string, ...)
	510	{
	511	#define EXPAND_MAX_KEYS 16
	512	struct {
	513	const char *key;
	514	const char *repl;
	515	} keys[EXPAND_MAX_KEYS];
2ceb8101	516	u_int num_keys, i, j;
a980cbd7	517	char buf[4096];
	518	va_list ap;
	519
	520	/* Gather keys */
	521	va_start(ap, string);
	522	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
	523	keys[num_keys].key = va_arg(ap, char *);
	524	if (keys[num_keys].key == NULL)
	525	break;
	526	keys[num_keys].repl = va_arg(ap, char *);
	527	if (keys[num_keys].repl == NULL)
	528	fatal("percent_expand: NULL replacement");
	529	}
	530	va_end(ap);
	531
	532	if (num_keys >= EXPAND_MAX_KEYS)
	533	fatal("percent_expand: too many keys");
	534
	535	/* Expand string */
	536	*buf = '\0';
	537	for (i = 0; *string != '\0'; string++) {
	538	if (*string != '%') {
	539	append:
	540	buf[i++] = *string;
	541	if (i >= sizeof(buf))
	542	fatal("percent_expand: string too long");
	543	buf[i] = '\0';
	544	continue;
	545	}
	546	string++;
	547	if (*string == '%')
	548	goto append;
	549	for (j = 0; j < num_keys; j++) {
	550	if (strchr(keys[j].key, *string) != NULL) {
	551	i = strlcat(buf, keys[j].repl, sizeof(buf));
	552	if (i >= sizeof(buf))
	553	fatal("percent_expand: string too long");
	554	break;
	555	}
	556	}
	557	if (j >= num_keys)
	558	fatal("percent_expand: unknown key %%%c", *string);
	559	}
	560	return (xstrdup(buf));
	561	#undef EXPAND_MAX_KEYS
	562	}
	563
ea067773	564	/*
	565	* Read an entire line from a public key file into a static buffer, discarding
	566	* lines that exceed the buffer size. Returns 0 on success, -1 on failure.
	567	*/
	568	int
	569	read_keyfile_line(FILE f, const char filename, char *buf, size_t bufsz,
41feb690	570	u_long *lineno)
ea067773	571	{
	572	while (fgets(buf, bufsz, f) != NULL) {
	573	(*lineno)++;
	574	if (buf[strlen(buf) - 1] == '\n' \|\| feof(f)) {
	575	return 0;
	576	} else {
41feb690	577	debug("%s: %s line %lu exceeds size limit", __func__,
41feb690	578	filename, *lineno);
ea067773	579	/* discard remainder of line */
f8cc7664	580	while (fgetc(f) != '\n' && !feof(f))
ea067773	581	; /* nothing */
	582	}
	583	}
	584	return -1;
	585	}
ef07103c	586
d20f3c9e	587	int
a4f24bf8	588	tun_open(int tun, int mode)
d20f3c9e	589	{
6306853a	590	#if defined(CUSTOM_SYS_TUN_OPEN)
6306853a	591	return (sys_tun_open(tun, mode));
0f6cb079	592	#elif defined(SSH_TUN_OPENBSD)
a4f24bf8	593	struct ifreq ifr;
d20f3c9e	594	char name[100];
a4f24bf8	595	int fd = -1, sock;
d20f3c9e	596
a4f24bf8	597	/* Open the tunnel device */
a4f24bf8	598	if (tun <= SSH_TUNID_MAX) {
d20f3c9e	599	snprintf(name, sizeof(name), "/dev/tun%d", tun);
a4f24bf8	600	fd = open(name, O_RDWR);
	601	} else if (tun == SSH_TUNID_ANY) {
	602	for (tun = 100; tun >= 0; tun--) {
	603	snprintf(name, sizeof(name), "/dev/tun%d", tun);
	604	if ((fd = open(name, O_RDWR)) >= 0)
	605	break;
d20f3c9e	606	}
d20f3c9e	607	} else {
81c042a3	608	debug("%s: invalid tunnel %u", __func__, tun);
a4f24bf8	609	return (-1);
	610	}
	611
	612	if (fd < 0) {
	613	debug("%s: %s open failed: %s", __func__, name, strerror(errno));
	614	return (-1);
	615	}
	616
	617	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
	618
	619	/* Set the tunnel device operation mode */
	620	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
	621	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
	622	goto failed;
	623
	624	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
	625	goto failed;
b1b65311	626
	627	/* Set interface mode */
	628	ifr.ifr_flags &= ~IFF_UP;
	629	if (mode == SSH_TUNMODE_ETHERNET)
a4f24bf8	630	ifr.ifr_flags \|= IFF_LINK0;
b1b65311	631	else
	632	ifr.ifr_flags &= ~IFF_LINK0;
	633	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	634	goto failed;
	635
	636	/* Bring interface up */
a4f24bf8	637	ifr.ifr_flags \|= IFF_UP;
	638	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
	639	goto failed;
	640
	641	close(sock);
	642	return (fd);
	643
	644	failed:
	645	if (fd >= 0)
	646	close(fd);
	647	if (sock >= 0)
	648	close(sock);
	649	debug("%s: failed to set %s mode %d: %s", __func__, name,
	650	mode, strerror(errno));
d20f3c9e	651	return (-1);
6306853a	652	#else
	653	error("Tunnel interfaces are not supported on this platform");
	654	return (-1);
	655	#endif
d20f3c9e	656	}
d20f3c9e	657
fd6168c1	658	void
	659	sanitise_stdfd(void)
	660	{
db382686	661	int nullfd, dupfd;
fd6168c1	662
db382686	663	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
fd6168c1	664	fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
	665	exit(1);
	666	}
db382686	667	while (++dupfd <= 2) {
	668	/* Only clobber closed fds */
	669	if (fcntl(dupfd, F_GETFL, 0) >= 0)
	670	continue;
	671	if (dup2(nullfd, dupfd) == -1) {
fd6168c1	672	fprintf(stderr, "dup2: %s", strerror(errno));
	673	exit(1);
	674	}
fd6168c1	675	}
	676	if (nullfd > 2)
	677	close(nullfd);
	678	}
	679
ef07103c	680	char *
	681	tohex(const u_char *d, u_int l)
	682	{
	683	char b[3], *r;
	684	u_int i, hl;
	685
	686	hl = l * 2 + 1;
	687	r = xmalloc(hl);
	688	*r = '\0';
	689	for (i = 0; i < l; i++) {
	690	snprintf(b, sizeof(b), "%02x", d[i]);
	691	strlcat(r, b, hl);
	692	}
	693	return (r);
	694	}
	695