lsm: move the AF_UNIX hook comments to security/security.c

This patch relocates the LSM hook function comments to the function
definitions, in keeping with the current kernel conventions.  This
should make the hook descriptions more easily discoverable and easier
to maintain.

While formatting changes have been done to better fit the kernel-doc
style, content changes have been kept to a minimum and limited to
text which was obviously incorrect and/or outdated.  It is expected
the future patches will improve the quality of the function header
comments.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 41 insertions, 1 deletions

diff --git a/security/security.c b/security/security.c
index b5fe49ac564e..9112531e6c2e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -3555,13 +3555,53 @@ int security_watch_key(struct key *key)
 #endif
 
 #ifdef CONFIG_SECURITY_NETWORK
-
+/**
+ * security_unix_stream_connect() - Check if a AF_UNIX stream is allowed
+ * @sock: originating sock
+ * @other: peer sock
+ * @newsk: new sock
+ *
+ * Check permissions before establishing a Unix domain stream connection
+ * between @sock and @other.
+ *
+ * The @unix_stream_connect and @unix_may_send hooks were necessary because
+ * Linux provides an alternative to the conventional file name space for Unix
+ * domain sockets.  Whereas binding and connecting to sockets in the file name
+ * space is mediated by the typical file permissions (and caught by the mknod
+ * and permission hooks in inode_security_ops), binding and connecting to
+ * sockets in the abstract name space is completely unmediated.  Sufficient
+ * control of Unix domain sockets in the abstract name space isn't possible
+ * using only the socket layer hooks, since we need to know the actual target
+ * socket, which is not looked up until we are inside the af_unix code.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
 int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk)
 {
 	return call_int_hook(unix_stream_connect, 0, sock, other, newsk);
 }
 EXPORT_SYMBOL(security_unix_stream_connect);
 
+/**
+ * security_unix_may_send() - Check if AF_UNIX socket can send datagrams
+ * @sock: originating sock
+ * @other: peer sock
+ *
+ * Check permissions before connecting or sending datagrams from @sock to
+ * @other.
+ *
+ * The @unix_stream_connect and @unix_may_send hooks were necessary because
+ * Linux provides an alternative to the conventional file name space for Unix
+ * domain sockets.  Whereas binding and connecting to sockets in the file name
+ * space is mediated by the typical file permissions (and caught by the mknod
+ * and permission hooks in inode_security_ops), binding and connecting to
+ * sockets in the abstract name space is completely unmediated.  Sufficient
+ * control of Unix domain sockets in the abstract name space isn't possible
+ * using only the socket layer hooks, since we need to know the actual target
+ * socket, which is not looked up until we are inside the af_unix code.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
 int security_unix_may_send(struct socket *sock,  struct socket *other)
 {
 	return call_int_hook(unix_may_send, 0, sock, other);