[NETLINK]: Encapsulate eff_cap usage within security framework.

This patch encapsulates the usage of eff_cap (in netlink_skb_params) within
the security framework by extending security_netlink_recv to include a required
capability parameter and converting all direct usage of eff_caps outside
of the lsm modules to use the interface.  It also updates the SELinux
implementation of the security_netlink_send and security_netlink_recv
hooks to take advantage of the sid in the netlink_skb_params struct.
This also enables SELinux to perform auditing of netlink capability checks.
Please apply, for 2.6.18 if possible.

Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by:  James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 6 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 51805806f974..c7ea15716dce 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -67,7 +67,7 @@ struct xfrm_state;
 struct xfrm_user_sec_ctx;
 
 extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
-extern int cap_netlink_recv(struct sk_buff *skb);
+extern int cap_netlink_recv(struct sk_buff *skb, int cap);
 
 /*
  * Values used in the task_security_ops calls
@@ -656,6 +656,7 @@ struct swap_info_struct;
  *      Check permission before processing the received netlink message in
  *      @skb.
  *      @skb contains the sk_buff structure for the netlink message.
+ *      @cap indicates the capability required
  *      Return 0 if permission is granted.
  *
  * Security hooks for Unix domain networking.
@@ -1266,7 +1267,7 @@ struct security_operations {
                           struct sembuf * sops, unsigned nsops, int alter);
 
         int (*netlink_send) (struct sock * sk, struct sk_buff * skb);
-        int (*netlink_recv) (struct sk_buff * skb);
+        int (*netlink_recv) (struct sk_buff * skb, int cap);
 
         /* allow module stacking */
         int (*register_security) (const char *name,
@@ -2032,9 +2033,9 @@ static inline int security_netlink_send(struct sock *sk, struct sk_buff * skb)
         return security_ops->netlink_send(sk, skb);
 }
 
-static inline int security_netlink_recv(struct sk_buff * skb)
+static inline int security_netlink_recv(struct sk_buff * skb, int cap)
 {
-        return security_ops->netlink_recv(skb);
+        return security_ops->netlink_recv(skb, cap);
 }
 
 /* prototypes */
@@ -2670,9 +2671,9 @@ static inline int security_netlink_send (struct sock *sk, struct sk_buff *skb)
         return cap_netlink_send (sk, skb);
 }
 
-static inline int security_netlink_recv (struct sk_buff *skb)
+static inline int security_netlink_recv (struct sk_buff *skb, int cap)
 {
-        return cap_netlink_recv (skb);
+        return cap_netlink_recv (skb, cap);
 }
 
 static inline struct dentry *securityfs_create_dir(const char *name,