[PATCH v7 04/16] LSM: List multiple security attributes in security_inode_listsecurity

[Casey Schaufler <casey@schaufler-ca.com>]

Listing security extended attributes is extended to the case
where there is more than one security module that provides them.
The same format used in other xattr list providers:
	name1\0name2\0name3
is used.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/security.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/security/security.c b/security/security.c
index a58e60970035..87cb3562646b 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1475,9 +1475,34 @@ int security_inode_setsecurity(struct inode *inode, const char *name, const void
 
 int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
 {
+	struct security_hook_list *hp;
+	bool first = true;
+	int finallen = 0;
+	int len;
+
 	if (unlikely(IS_PRIVATE(inode)))
 		return 0;
-	return call_int_hook(inode_listsecurity, 0, inode, buffer, buffer_size);
+
+	hlist_for_each_entry(hp, &security_hook_heads.inode_listsecurity,
+			     list) {
+		len = hp->hook.inode_listsecurity(inode, buffer, buffer_size);
+		if (len < buffer_size) {
+			if (buffer)
+				buffer[len] = '\0';
+			buffer_size -= len + 1;
+		} else {
+			buffer = NULL;
+			buffer_size = 0;
+		}
+		if (first) {
+			finallen = len;
+			first = false;
+		} else
+			finallen += len + 1;
+		if (buffer)
+			buffer += len + 1;
+	}
+	return finallen;
 }
 EXPORT_SYMBOL(security_inode_listsecurity);
 
-- 
2.20.1