security: add a secctx_to_secid() hook

Add a secctx_to_secid() LSM hook to go along with the existing
secid_to_secctx() LSM hook.  This patch also includes the SELinux
implementation for this hook.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index 2e2c63faead7..e4a91cb1b187 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1202,6 +1202,10 @@ struct request_sock;
  *	Convert secid to security context.
  *	@secid contains the security ID.
  *	@secdata contains the pointer that stores the converted security context.
+ * @secctx_to_secid:
+ *      Convert security context to secid.
+ *      @secid contains the pointer to the generated security ID.
+ *      @secdata contains the security context.
  *
  * @release_secctx:
  *	Release the security context.
@@ -1396,6 +1400,7 @@ struct security_operations {
  	int (*getprocattr)(struct task_struct *p, char *name, char **value);
  	int (*setprocattr)(struct task_struct *p, char *name, void *value, size_t size);
 	int (*secid_to_secctx)(u32 secid, char **secdata, u32 *seclen);
+	int (*secctx_to_secid)(char *secdata, u32 seclen, u32 *secid);
 	void (*release_secctx)(char *secdata, u32 seclen);
 
 #ifdef CONFIG_SECURITY_NETWORK
@@ -1634,6 +1639,7 @@ int security_setprocattr(struct task_struct *p, char *name, void *value, size_t
 int security_netlink_send(struct sock *sk, struct sk_buff *skb);
 int security_netlink_recv(struct sk_buff *skb, int cap);
 int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
+int security_secctx_to_secid(char *secdata, u32 seclen, u32 *secid);
 void security_release_secctx(char *secdata, u32 seclen);
 
 #else /* CONFIG_SECURITY */
@@ -2308,6 +2314,13 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
 	return -EOPNOTSUPP;
 }
 
+static inline int security_secctx_to_secid(char *secdata,
+					   u32 seclen,
+					   u32 *secid)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline void security_release_secctx(char *secdata, u32 seclen)
 {
 }