[MLSXFRM]: Add security sid to sock

This adds security for IP sockets at the sock level. Security at the
sock level is needed to enforce the SELinux security policy for
security associations even when a sock is orphaned (such as in the TCP
LAST_ACK state).

This will also be used to enforce SELinux controls over data arriving
at or leaving a child socket while it's still waiting to be accepted.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 6bc2aad494ff..4d7fb59996b0 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -812,6 +812,8 @@ struct swap_info_struct;
  *      which is used to copy security attributes between local stream sockets.
  * @sk_free_security:
  *      Deallocate security structure.
+ * @sk_clone_security:
+ *      Clone/copy security structure.
  * @sk_getsid:
  *      Retrieve the LSM-specific sid for the sock to enable caching of network
  *      authorizations.
@@ -1332,6 +1334,7 @@ struct security_operations {
         int (*socket_getpeersec_dgram) (struct socket *sock, struct sk_buff *skb, u32 *secid);
         int (*sk_alloc_security) (struct sock *sk, int family, gfp_t priority);
         void (*sk_free_security) (struct sock *sk);
+        void (*sk_clone_security) (const struct sock *sk, struct sock *newsk);
         unsigned int (*sk_getsid) (struct sock *sk, struct flowi *fl, u8 dir);
 #endif  /* CONFIG_SECURITY_NETWORK */
 
@@ -2885,6 +2888,11 @@ static inline void security_sk_free(struct sock *sk)
         return security_ops->sk_free_security(sk);
 }
 
+static inline void security_sk_clone(const struct sock *sk, struct sock *newsk)
+{
+        return security_ops->sk_clone_security(sk, newsk);
+}
+
 static inline unsigned int security_sk_sid(struct sock *sk, struct flowi *fl, u8 dir)
 {
         return security_ops->sk_getsid(sk, fl, dir);
@@ -3011,6 +3019,10 @@ static inline void security_sk_free(struct sock *sk)
 {
 }
 
+static inline void security_sk_clone(const struct sock *sk, struct sock *newsk)
+{
+}
+
 static inline unsigned int security_sk_sid(struct sock *sk, struct flowi *fl, u8 dir)
 {
         return 0;
diff --git a/include/net/sock.h b/include/net/sock.h
index 324b3ea233d6..91cdceb3c028 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -972,6 +972,19 @@ static inline void sock_graft(struct sock *sk, struct socket *parent)
         write_unlock_bh(&sk->sk_callback_lock);
 }
 
+static inline void sock_copy(struct sock *nsk, const struct sock *osk)
+{
+#ifdef CONFIG_SECURITY_NETWORK
+        void *sptr = nsk->sk_security;
+#endif
+
+        memcpy(nsk, osk, osk->sk_prot->obj_size);
+#ifdef CONFIG_SECURITY_NETWORK
+        nsk->sk_security = sptr;
+        security_sk_clone(osk, nsk);
+#endif
+}
+
 extern int sock_i_uid(struct sock *sk);
 extern unsigned long sock_i_ino(struct sock *sk);