TOMOYO: Add policy namespace support.

Mauras Olivier reported that it is difficult to use TOMOYO in LXC environments,
for TOMOYO cannot distinguish between environments outside the container and
environments inside the container since LXC environments are created using
pivot_root(). To address this problem, this patch introduces policy namespace.

Each policy namespace has its own set of domain policy, exception policy and
profiles, which are all independent of other namespaces. This independency
allows users to develop policy without worrying interference among namespaces.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 40 insertions, 33 deletions

diff --git a/security/tomoyo/gc.c b/security/tomoyo/gc.c
index 412ee8309c2..782e844dca7 100644
--- a/security/tomoyo/gc.c
+++ b/security/tomoyo/gc.c
@@ -292,15 +292,12 @@ static bool tomoyo_collect_acl(struct list_head *list)
 static void tomoyo_collect_entry(void)
 {
         int i;
+        enum tomoyo_policy_id id;
+        struct tomoyo_policy_namespace *ns;
+        int idx;
         if (mutex_lock_interruptible(&tomoyo_policy_lock))
                 return;
-        for (i = 0; i < TOMOYO_MAX_POLICY; i++) {
-                if (!tomoyo_collect_member(i, &tomoyo_policy_list[i]))
-                        goto unlock;
-        }
-        for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
-                if (!tomoyo_collect_acl(&tomoyo_acl_group[i]))
-                        goto unlock;
+        idx = tomoyo_read_lock();
         {
                 struct tomoyo_domain_info *domain;
                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
@@ -317,39 +314,49 @@ static void tomoyo_collect_entry(void)
                                 goto unlock;
                 }
         }
-        for (i = 0; i < TOMOYO_MAX_HASH; i++) {
-                struct tomoyo_name *ptr;
-                list_for_each_entry_rcu(ptr, &tomoyo_name_list[i], head.list) {
-                        if (atomic_read(&ptr->head.users))
-                                continue;
-                        if (!tomoyo_add_to_gc(TOMOYO_ID_NAME, &ptr->head.list))
+        list_for_each_entry_rcu(ns, &tomoyo_namespace_list, namespace_list) {
+                for (id = 0; id < TOMOYO_MAX_POLICY; id++)
+                        if (!tomoyo_collect_member(id, &ns->policy_list[id]))
                                 goto unlock;
+                for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
+                        if (!tomoyo_collect_acl(&ns->acl_group[i]))
+                                goto unlock;
+                for (i = 0; i < TOMOYO_MAX_GROUP; i++) {
+                        struct list_head *list = &ns->group_list[i];
+                        struct tomoyo_group *group;
+                        switch (i) {
+                        case 0:
+                                id = TOMOYO_ID_PATH_GROUP;
+                                break;
+                        default:
+                                id = TOMOYO_ID_NUMBER_GROUP;
+                                break;
+                        }
+                        list_for_each_entry(group, list, head.list) {
+                                if (!tomoyo_collect_member
+                                    (id, &group->member_list))
+                                        goto unlock;
+                                if (!list_empty(&group->member_list) ||
+                                    atomic_read(&group->head.users))
+                                        continue;
+                                if (!tomoyo_add_to_gc(TOMOYO_ID_GROUP,
+                                                      &group->head.list))
+                                        goto unlock;
+                        }
                 }
         }
-        for (i = 0; i < TOMOYO_MAX_GROUP; i++) {
-                struct list_head *list = &tomoyo_group_list[i];
-                int id;
-                struct tomoyo_group *group;
-                switch (i) {
-                case 0:
-                        id = TOMOYO_ID_PATH_GROUP;
-                        break;
-                default:
-                        id = TOMOYO_ID_NUMBER_GROUP;
-                        break;
-                }
-                list_for_each_entry(group, list, head.list) {
-                        if (!tomoyo_collect_member(id, &group->member_list))
-                                goto unlock;
-                        if (!list_empty(&group->member_list) ||
-                            atomic_read(&group->head.users))
+        for (i = 0; i < TOMOYO_MAX_HASH; i++) {
+                struct list_head *list = &tomoyo_name_list[i];
+                struct tomoyo_shared_acl_head *ptr;
+                list_for_each_entry(ptr, list, list) {
+                        if (atomic_read(&ptr->users))
                                 continue;
-                        if (!tomoyo_add_to_gc(TOMOYO_ID_GROUP,
-                                              &group->head.list))
+                        if (!tomoyo_add_to_gc(TOMOYO_ID_NAME, &ptr->list))
                                 goto unlock;
                 }
         }
- unlock:
+unlock:
+        tomoyo_read_unlock(idx);
         mutex_unlock(&tomoyo_policy_lock);
 }