security: Add Linux Security Modules hook for AF_BUS sockets

AF_BUS implements a security hook bus_connect() to be used by LSM
to enforce connectivity security policies.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>

3 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 673afbb8238a..fa26c6d07002 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1578,6 +1578,8 @@ struct security_operations {
 
 #ifdef CONFIG_SECURITY_NETWORK
 	int (*unix_stream_connect) (struct sock *sock, struct sock *other, struct sock *newsk);
+	int (*bus_connect) (struct sock *sock, struct sock *other,
+			    struct sock *newsk);
 	int (*unix_may_send) (struct socket *sock, struct socket *other);
 
 	int (*socket_create) (int family, int type, int protocol, int kern);
@@ -2517,6 +2519,8 @@ static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32
 #ifdef CONFIG_SECURITY_NETWORK
 
 int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk);
+int security_bus_connect(struct sock *sock, struct sock *other,
+			 struct sock *newsk);
 int security_unix_may_send(struct socket *sock,  struct socket *other);
 int security_socket_create(int family, int type, int protocol, int kern);
 int security_socket_post_create(struct socket *sock, int family,
@@ -2564,6 +2568,13 @@ static inline int security_unix_stream_connect(struct sock *sock,
 	return 0;
 }
 
+static inline int security_bus_connect(struct socket *sock,
+				       struct sock *other,
+				       struct sock *newsk)
+{
+	return 0;
+}
+
 static inline int security_unix_may_send(struct socket *sock,
 					 struct socket *other)
 {
diff --git a/security/capability.c b/security/capability.c
index 5bb21b1c448c..5b966a60a4c0 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -563,6 +563,12 @@ static int cap_unix_may_send(struct socket *sock, struct socket *other)
 	return 0;
 }
 
+static int cap_bus_connect(struct sock *sock, struct sock *other,
+			   struct sock *newsk)
+{
+	return 0;
+}
+
 static int cap_socket_create(int family, int type, int protocol, int kern)
 {
 	return 0;
@@ -1015,6 +1021,7 @@ void __init security_fixup_ops(struct security_operations *ops)
 #ifdef CONFIG_SECURITY_NETWORK
 	set_to_cap_if_null(ops, unix_stream_connect);
 	set_to_cap_if_null(ops, unix_may_send);
+	set_to_cap_if_null(ops, bus_connect);
 	set_to_cap_if_null(ops, socket_create);
 	set_to_cap_if_null(ops, socket_post_create);
 	set_to_cap_if_null(ops, socket_bind);
diff --git a/security/security.c b/security/security.c
index bf619ffc9a4d..54582ea2f70d 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1018,6 +1018,13 @@ int security_unix_may_send(struct socket *sock,  struct socket *other)
 }
 EXPORT_SYMBOL(security_unix_may_send);
 
+int security_bus_connect(struct sock *sock, struct sock *other,
+				struct sock *newsk)
+{
+	return security_ops->bus_connect(sock, other, newsk);
+}
+EXPORT_SYMBOL(security_bus_connect);
+
 int security_socket_create(int family, int type, int protocol, int kern)
 {
 	return security_ops->socket_create(family, type, protocol, kern);