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>

3 files changed, 18 insertions, 0 deletions

diff --git a/security/dummy.c b/security/dummy.c
index 8e34e03415f8..48d4b0a52737 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -946,6 +946,11 @@ static int dummy_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
         return -EOPNOTSUPP;
 }
 
+static int dummy_secctx_to_secid(char *secdata, u32 seclen, u32 *secid)
+{
+        return -EOPNOTSUPP;
+}
+
 static void dummy_release_secctx(char *secdata, u32 seclen)
 {
 }
@@ -1106,6 +1111,7 @@ void security_fixup_ops (struct security_operations *ops)
         set_to_dummy_if_null(ops, getprocattr);
         set_to_dummy_if_null(ops, setprocattr);
         set_to_dummy_if_null(ops, secid_to_secctx);
+        set_to_dummy_if_null(ops, secctx_to_secid);
         set_to_dummy_if_null(ops, release_secctx);
 #ifdef CONFIG_SECURITY_NETWORK
         set_to_dummy_if_null(ops, unix_stream_connect);
diff --git a/security/security.c b/security/security.c
index 5068808343d0..ca475ca206e4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -831,6 +831,12 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
 }
 EXPORT_SYMBOL(security_secid_to_secctx);
 
+int security_secctx_to_secid(char *secdata, u32 seclen, u32 *secid)
+{
+        return security_ops->secctx_to_secid(secdata, seclen, secid);
+}
+EXPORT_SYMBOL(security_secctx_to_secid);
+
 void security_release_secctx(char *secdata, u32 seclen)
 {
         return security_ops->release_secctx(secdata, seclen);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 233c8b97462f..0396354fff95 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4947,6 +4947,11 @@ static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
         return security_sid_to_context(secid, secdata, seclen);
 }
 
+static int selinux_secctx_to_secid(char *secdata, u32 seclen, u32 *secid)
+{
+        return security_context_to_sid(secdata, seclen, secid);
+}
+
 static void selinux_release_secctx(char *secdata, u32 seclen)
 {
         kfree(secdata);
@@ -5138,6 +5143,7 @@ static struct security_operations selinux_ops = {
         .setprocattr =                  selinux_setprocattr,
 
         .secid_to_secctx =              selinux_secid_to_secctx,
+        .secctx_to_secid =              selinux_secctx_to_secid,
         .release_secctx =               selinux_release_secctx,
 
         .unix_stream_connect =          selinux_socket_unix_stream_connect,