LSM: Introduce inode_getsecid and ipc_getsecid hooks

Introduce inode_getsecid(inode, secid) and ipc_getsecid(ipcp, secid)
LSM hooks. These hooks will be used instead of similar exported
SELinux interfaces.

Let {inode,ipc,task}_getsecid hooks set the secid to 0 by default
if CONFIG_SECURITY is not defined or if the hook is set to
NULL (dummy). This is done to notify the caller that no valid
secid exists.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Reviewed-by: Paul Moore <paul.moore@hp.com>

2 files changed, 25 insertions, 1 deletions

diff --git a/security/dummy.c b/security/dummy.c
index 78d8f92310a4..fb2e942efbb6 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -424,6 +424,11 @@ static int dummy_inode_listsecurity(struct inode *inode, char *buffer, size_t bu
 	return 0;
 }
 
+static void dummy_inode_getsecid(const struct inode *inode, u32 *secid)
+{
+	*secid = 0;
+}
+
 static int dummy_file_permission (struct file *file, int mask)
 {
 	return 0;
@@ -542,7 +547,9 @@ static int dummy_task_getsid (struct task_struct *p)
 }
 
 static void dummy_task_getsecid (struct task_struct *p, u32 *secid)
-{ }
+{
+	*secid = 0;
+}
 
 static int dummy_task_setgroups (struct group_info *group_info)
 {
@@ -616,6 +623,11 @@ static int dummy_ipc_permission (struct kern_ipc_perm *ipcp, short flag)
 	return 0;
 }
 
+static void dummy_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+{
+	*secid = 0;
+}
+
 static int dummy_msg_msg_alloc_security (struct msg_msg *msg)
 {
 	return 0;
@@ -1058,6 +1070,7 @@ void security_fixup_ops (struct security_operations *ops)
 	set_to_dummy_if_null(ops, inode_getsecurity);
 	set_to_dummy_if_null(ops, inode_setsecurity);
 	set_to_dummy_if_null(ops, inode_listsecurity);
+	set_to_dummy_if_null(ops, inode_getsecid);
 	set_to_dummy_if_null(ops, file_permission);
 	set_to_dummy_if_null(ops, file_alloc_security);
 	set_to_dummy_if_null(ops, file_free_security);
@@ -1094,6 +1107,7 @@ void security_fixup_ops (struct security_operations *ops)
 	set_to_dummy_if_null(ops, task_reparent_to_init);
  	set_to_dummy_if_null(ops, task_to_inode);
 	set_to_dummy_if_null(ops, ipc_permission);
+	set_to_dummy_if_null(ops, ipc_getsecid);
 	set_to_dummy_if_null(ops, msg_msg_alloc_security);
 	set_to_dummy_if_null(ops, msg_msg_free_security);
 	set_to_dummy_if_null(ops, msg_queue_alloc_security);
diff --git a/security/security.c b/security/security.c
index 9beecac933b4..290482bdbbb0 100644
--- a/security/security.c
+++ b/security/security.c
@@ -523,6 +523,11 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
 	return security_ops->inode_listsecurity(inode, buffer, buffer_size);
 }
 
+void security_inode_getsecid(const struct inode *inode, u32 *secid)
+{
+	security_ops->inode_getsecid(inode, secid);
+}
+
 int security_file_permission(struct file *file, int mask)
 {
 	return security_ops->file_permission(file, mask);
@@ -712,6 +717,11 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
 	return security_ops->ipc_permission(ipcp, flag);
 }
 
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+{
+	security_ops->ipc_getsecid(ipcp, secid);
+}
+
 int security_msg_msg_alloc(struct msg_msg *msg)
 {
 	return security_ops->msg_msg_alloc_security(msg);