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Commit 99dbbb59 authored by Al Viro's avatar Al Viro
Browse files

selinux: rewrite selinux_sb_eat_lsm_opts()



make it use selinux_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 da3d76ab
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+54 −92
Original line number Original line Diff line number Diff line
@@ -2606,109 +2606,71 @@ static void selinux_sb_free_security(struct super_block *sb)
	superblock_free_security(sb);
	superblock_free_security(sb);
}
}


static inline int match_prefix(char *prefix, int plen, char *option, int olen)
static inline int opt_len(const char *s)
{
{
	if (plen > olen)
	bool open_quote = false;
		return 0;
	int len;
	char c;


	return !memcmp(prefix, option, plen);
	for (len = 0; (c = s[len]) != '\0'; len++) {
		if (c == '"')
			open_quote = !open_quote;
		if (c == ',' && !open_quote)
			break;
	}
	}

	return len;
static inline int selinux_option(char *option, int len)
{
	return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
		match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
		match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
}
}


static inline void take_option(char **to, char *from, int *first, int len)
static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
{
{
	if (!*first) {
	char *from = options;
		**to = ',';
	char *to = options;
		*to += 1;
	bool first = true;
	} else
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}


static inline void take_selinux_option(char **to, char *from, int *first,
	while (1) {
				       int len)
		int len = opt_len(from);
{
		int token, rc;
	int current_size = 0;
		char *arg = NULL;


	if (!*first) {
		token = match_opt_prefix(from, len, &arg);
		**to = '|';

		*to += 1;
		if (token != Opt_error) {
	} else
			char *p, *q;
		*first = 0;


	while (current_size < len) {
			/* strip quotes */
		if (*from != '"') {
			if (arg) {
			**to = *from;
				for (p = q = arg; p < from + len; p++) {
			*to += 1;
					char c = *p;
					if (c != '"')
						*q++ = c;
				}
				}
		from += 1;
				arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
		current_size += 1;
			}
			}
			rc = selinux_add_opt(token, arg, mnt_opts);
			if (unlikely(rc)) {
				kfree(arg);
				if (*mnt_opts) {
					selinux_free_mnt_opts(*mnt_opts);
					*mnt_opts = NULL;
				}
				}

				return rc;
static int selinux_sb_copy_data(char *orig, char *copy)
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
	int open_quote = 0;

	in_curr = orig;
	sec_curr = copy;

	nosec = (char *)get_zeroed_page(GFP_KERNEL);
	if (!nosec) {
		rc = -ENOMEM;
		goto out;
			}
			}

		} else {
	nosec_save = nosec;
			if (!first) {	// copy with preceding comma
	fnosec = fsec = 1;
				from--;
	in_save = in_end = orig;
				len++;

	do {
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
			else
				take_option(&nosec, in_curr, &fnosec, len);

			in_curr = in_end + 1;
			}
			}
	} while (*in_end++);
			if (to != from)

				memmove(to, from, len);
	strcpy(in_save, nosec_save);
			to += len;
	free_page((unsigned long)nosec_save);
			first = false;
out:
	return rc;
		}
		}

		if (!from[len])
static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
			break;
{
		from += len + 1;
	char *s = (char *)get_zeroed_page(GFP_KERNEL);
	}
	int err;
	*to = '\0';

	return 0;
	if (!s)
		return -ENOMEM;
	err = selinux_sb_copy_data(options, s);
	if (!err)
		err = selinux_parse_opts_str(s, mnt_opts);
	free_page((unsigned long)s);
	return err;
}
}


static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)