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Commit d2497e12 authored by Al Viro's avatar Al Viro
Browse files

smack: rewrite smack_sb_eat_lsm_opts() 



make it use smack_add_opt() and avoid separate copies - gather
non-LSM options by memmove() in place

Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent c3300aaf

security/smack/smack_lsm.c

+23 −85
Original line number Diff line number Diff line
@@ -599,53 +599,6 @@ static void smack_free_mnt_opts(void *mnt_opts) 
	kfree(opts);

}



/**

 * smack_sb_copy_data - copy mount options data for processing

 * @orig: where to start

 * @smackopts: mount options string

 *

 * Returns 0 on success or -ENOMEM on error.

 *

 * Copy the Smack specific mount options out of the mount

 * options list.

 */

static int smack_sb_copy_data(char *orig, char *smackopts)

{

	char *cp, *commap, *otheropts, *dp;



	otheropts = (char *)get_zeroed_page(GFP_KERNEL);

	if (otheropts == NULL)

		return -ENOMEM;



	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {

		if (strstr(cp, SMK_FSDEFAULT) == cp)

			dp = smackopts;

		else if (strstr(cp, SMK_FSFLOOR) == cp)

			dp = smackopts;

		else if (strstr(cp, SMK_FSHAT) == cp)

			dp = smackopts;

		else if (strstr(cp, SMK_FSROOT) == cp)

			dp = smackopts;

		else if (strstr(cp, SMK_FSTRANS) == cp)

			dp = smackopts;

		else

			dp = otheropts;



		commap = strchr(cp, ',');

		if (commap != NULL)

			*commap = '\0';



		if (*dp != '\0')

			strcat(dp, ",");

		strcat(dp, cp);

	}



	strcpy(orig, otheropts);

	free_page((unsigned long)otheropts);



	return 0;

}



static int smack_add_opt(int token, const char *s, void **mnt_opts)

{

	struct smack_mnt_opts *opts = *mnt_opts;
@@ -656,7 +609,6 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts) 
			return -ENOMEM;

		*mnt_opts = opts;

	}



	if (!s)

		return -ENOMEM;
@@ -694,22 +646,10 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts) 
	return -EINVAL;

}



/**

 * smack_parse_opts_str - parse Smack specific mount options

 * @options: mount options string

 * @opts: where to store converted mount opts

 *

 * Returns 0 on success or -ENOMEM on error.

 *

 * converts Smack specific mount options to generic security option format

 */

static int smack_parse_opts_str(char *options,

		void **mnt_opts)

static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)

{

	char *from = options;



	if (!options)

		return 0;

	char *from = options, *to = options;

	bool first = true;



	while (1) {

		char *next = strchr(from, ',');
@@ -722,6 +662,7 @@ static int smack_parse_opts_str(char *options, 
			len = strlen(from);



		token = match_opt_prefix(from, len, &arg);

		if (token != Opt_error) {

			arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);

			rc = smack_add_opt(token, arg, mnt_opts);

			if (unlikely(rc)) {
@@ -731,27 +672,24 @@ static int smack_parse_opts_str(char *options, 
				*mnt_opts = NULL;

				return rc;

			}

		} else {

			if (!first) {	// copy with preceding comma

				from--;

				len++;

			}

			if (to != from)

				memmove(to, from, len);

			to += len;

			first = false;

		}

		if (!from[len])

			break;

		from += len + 1;

	}

	*to = '\0';

	return 0;

}



static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)

{

	char *s = (char *)get_zeroed_page(GFP_KERNEL);

	int err;



	if (!s)

		return -ENOMEM;

	err = smack_sb_copy_data(options, s);

	if (!err)

		err = smack_parse_opts_str(s, mnt_opts);

	free_page((unsigned long)s);

	return err;

}



/**

 * smack_set_mnt_opts - set Smack specific mount options

 * @sb: the file system superblock