TOMOYO: Use callback for updating entries.

Use common "struct list_head" + "bool" + "u8" structure and
use common code for elements using that structure.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

security/tomoyo/common.c

@@ -950,8 +950,6 @@ static bool tomoyo_print_mount_acl(struct tomoyo_io_buffer *head,
 				   struct tomoyo_mount_acl *ptr)
 {
 	const int pos = head->read_avail;
-	if (ptr->is_deleted)
-		return true;
 	if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_ALLOW_MOUNT) ||
 	    !tomoyo_print_name_union(head, &ptr->dev_name) ||
 	    !tomoyo_print_name_union(head, &ptr->dir_name) ||
@@ -977,6 +975,8 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
 {
 	const u8 acl_type = ptr->type;
 
+	if (ptr->is_deleted)
+		return true;
 	if (acl_type == TOMOYO_TYPE_PATH_ACL) {
 		struct tomoyo_path_acl *acl
 			= container_of(ptr, struct tomoyo_path_acl, head);

security/tomoyo/common.h

@@ -112,6 +112,8 @@ enum tomoyo_path_acl_index {
 	TOMOYO_MAX_PATH_OPERATION
 };
 
+#define TOMOYO_RW_MASK ((1 << TOMOYO_TYPE_READ) | (1 << TOMOYO_TYPE_WRITE))
+
 enum tomoyo_path_number3_acl_index {
 	TOMOYO_TYPE_MKBLOCK,
 	TOMOYO_TYPE_MKCHAR,
@@ -289,17 +291,19 @@ struct tomoyo_number_group_member {
  *
  *  (1) "list" which is linked to the ->acl_info_list of
  *      "struct tomoyo_domain_info"
- *  (2) "type" which tells type of the entry (either
- *      "struct tomoyo_path_acl" or "struct tomoyo_path2_acl").
+ *  (2) "is_deleted" is a bool which is true if this domain is marked as
+ *      "deleted", false otherwise.
+ *  (3) "type" which tells type of the entry.
  *
  * Packing "struct tomoyo_acl_info" allows
- * "struct tomoyo_path_acl" to embed "u8" + "u16" and
- * "struct tomoyo_path2_acl" to embed "u8"
- * without enlarging their structure size.
+ * "struct tomoyo_path_acl" to embed "u16" and "struct tomoyo_path2_acl"
+ * "struct tomoyo_path_number_acl" "struct tomoyo_path_number3_acl" to embed
+ * "u8" without enlarging their structure size.
  */
 struct tomoyo_acl_info {
 	struct list_head list;
-	u8 type;
+	bool is_deleted;
+	u8 type; /* = one of values in "enum tomoyo_acl_entry_type_index". */
 } __packed;
 
 /*
@@ -438,17 +442,15 @@ struct tomoyo_path2_acl {
  * It has following fields.
  *
  *  (1) "head" which is a "struct tomoyo_acl_info".
- *  (2) "is_deleted" is boolean.
- *  (3) "dev_name" is the device name.
- *  (4) "dir_name" is the mount point.
+ *  (2) "dev_name" is the device name.
+ *  (3) "dir_name" is the mount point.
+ *  (4) "fs_type" is the filesystem type.
  *  (5) "flags" is the mount flags.
  *
- * Directives held by this structure are "allow_rename", "allow_link" and
- * "allow_pivot_root".
+ * Directive held by this structure is "allow_mount".
  */
 struct tomoyo_mount_acl {
 	struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_MOUNT_ACL */
-	bool is_deleted;
 	struct tomoyo_name_union dev_name;
 	struct tomoyo_name_union dir_name;
 	struct tomoyo_name_union fs_type;
@@ -914,6 +916,16 @@ void tomoyo_run_gc(void);
 
 void tomoyo_memory_free(void *ptr);
 
+int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
+			 bool is_delete, struct tomoyo_domain_info *domain,
+			 bool (*check_duplicate) (const struct tomoyo_acl_info
+						  *,
+						  const struct tomoyo_acl_info
+						  *),
+			 bool (*merge_duplicate) (struct tomoyo_acl_info *,
+						  struct tomoyo_acl_info *,
+						  const bool));
+
 /********** External variable definitions. **********/
 
 /* Lock for GC. */
@@ -1042,52 +1054,6 @@ static inline bool tomoyo_is_same_number_union
 		p1->max_type == p2->max_type && p1->is_group == p2->is_group;
 }
 
-static inline bool tomoyo_is_same_path_acl(const struct tomoyo_path_acl *p1,
-					   const struct tomoyo_path_acl *p2)
-{
-	return tomoyo_is_same_acl_head(&p1->head, &p2->head) &&
-		tomoyo_is_same_name_union(&p1->name, &p2->name);
-}
-
-static inline bool tomoyo_is_same_path_number3_acl
-(const struct tomoyo_path_number3_acl *p1,
- const struct tomoyo_path_number3_acl *p2)
-{
-	return tomoyo_is_same_acl_head(&p1->head, &p2->head)
-		&& tomoyo_is_same_name_union(&p1->name, &p2->name)
-		&& tomoyo_is_same_number_union(&p1->mode, &p2->mode)
-		&& tomoyo_is_same_number_union(&p1->major, &p2->major)
-		&& tomoyo_is_same_number_union(&p1->minor, &p2->minor);
-}
-
-
-static inline bool tomoyo_is_same_path2_acl(const struct tomoyo_path2_acl *p1,
-					    const struct tomoyo_path2_acl *p2)
-{
-	return tomoyo_is_same_acl_head(&p1->head, &p2->head) &&
-		tomoyo_is_same_name_union(&p1->name1, &p2->name1) &&
-		tomoyo_is_same_name_union(&p1->name2, &p2->name2);
-}
-
-static inline bool tomoyo_is_same_path_number_acl
-(const struct tomoyo_path_number_acl *p1,
- const struct tomoyo_path_number_acl *p2)
-{
-	return tomoyo_is_same_acl_head(&p1->head, &p2->head)
-		&& tomoyo_is_same_name_union(&p1->name, &p2->name)
-		&& tomoyo_is_same_number_union(&p1->number, &p2->number);
-}
-
-static inline bool tomoyo_is_same_mount_acl(const struct tomoyo_mount_acl *p1,
-					    const struct tomoyo_mount_acl *p2)
-{
-	return tomoyo_is_same_acl_head(&p1->head, &p2->head) &&
-		tomoyo_is_same_name_union(&p1->dev_name, &p2->dev_name) &&
-		tomoyo_is_same_name_union(&p1->dir_name, &p2->dir_name) &&
-		tomoyo_is_same_name_union(&p1->fs_type, &p2->fs_type) &&
-		tomoyo_is_same_number_union(&p1->flags, &p2->flags);
-}
-
 static inline bool tomoyo_is_same_domain_initializer_entry
 (const struct tomoyo_domain_initializer_entry *p1,
  const struct tomoyo_domain_initializer_entry *p2)

security/tomoyo/domain.c

@@ -15,6 +15,57 @@
 /* The initial domain. */
 struct tomoyo_domain_info tomoyo_kernel_domain;
 
+/**
+ * tomoyo_update_domain - Update an entry for domain policy.
+ *
+ * @new_entry:       Pointer to "struct tomoyo_acl_info".
+ * @size:            Size of @new_entry in bytes.
+ * @is_delete:       True if it is a delete request.
+ * @domain:          Pointer to "struct tomoyo_domain_info".
+ * @check_duplicate: Callback function to find duplicated entry.
+ * @merge_duplicate: Callback function to merge duplicated entry.
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
+			 bool is_delete, struct tomoyo_domain_info *domain,
+			 bool (*check_duplicate) (const struct tomoyo_acl_info
+						  *,
+						  const struct tomoyo_acl_info
+						  *),
+			 bool (*merge_duplicate) (struct tomoyo_acl_info *,
+						  struct tomoyo_acl_info *,
+						  const bool))
+{
+	int error = is_delete ? -ENOENT : -ENOMEM;
+	struct tomoyo_acl_info *entry;
+
+	if (mutex_lock_interruptible(&tomoyo_policy_lock))
+		return error;
+	list_for_each_entry_rcu(entry, &domain->acl_info_list, list) {
+		if (!check_duplicate(entry, new_entry))
+			continue;
+		if (merge_duplicate)
+			entry->is_deleted = merge_duplicate(entry, new_entry,
+							    is_delete);
+		else
+			entry->is_deleted = is_delete;
+		error = 0;
+		break;
+	}
+	if (error && !is_delete) {
+		entry = tomoyo_commit_ok(new_entry, size);
+		if (entry) {
+			list_add_tail_rcu(&entry->list, &domain->acl_info_list);
+			error = 0;
+		}
+	}
+	mutex_unlock(&tomoyo_policy_lock);
+	return error;
+}
+
 /*
  * tomoyo_domain_list is used for holding list of domains.
  * The ->acl_info_list of "struct tomoyo_domain_info" is used for holding

security/tomoyo/gc.c

@@ -310,34 +310,8 @@ static void tomoyo_collect_entry(void)
 			struct tomoyo_acl_info *acl;
 			list_for_each_entry_rcu(acl, &domain->acl_info_list,
 						list) {
-				switch (acl->type) {
-				case TOMOYO_TYPE_PATH_ACL:
-					if (container_of(acl,
-					 struct tomoyo_path_acl,
-							 head)->perm)
-						continue;
-					break;
-				case TOMOYO_TYPE_PATH2_ACL:
-					if (container_of(acl,
-					 struct tomoyo_path2_acl,
-							 head)->perm)
-						continue;
-					break;
-				case TOMOYO_TYPE_PATH_NUMBER_ACL:
-					if (container_of(acl,
-					 struct tomoyo_path_number_acl,
-							 head)->perm)
+				if (!acl->is_deleted)
 					continue;
-					break;
-				case TOMOYO_TYPE_PATH_NUMBER3_ACL:
-					if (container_of(acl,
-					 struct tomoyo_path_number3_acl,
-							 head)->perm)
-						continue;
-					break;
-				default:
-					continue;
-				}
 				if (tomoyo_add_to_gc(TOMOYO_ID_ACL, acl))
 					list_del_rcu(&acl->list);
 				else

security/tomoyo/mount.c

@@ -114,11 +114,10 @@ static int tomoyo_mount_acl2(struct tomoyo_request_info *r, char *dev_name,
 	tomoyo_fill_path_info(&rdev);
 	list_for_each_entry_rcu(ptr, &r->domain->acl_info_list, list) {
 		struct tomoyo_mount_acl *acl;
-		if (ptr->type != TOMOYO_TYPE_MOUNT_ACL)
+		if (ptr->is_deleted || ptr->type != TOMOYO_TYPE_MOUNT_ACL)
 			continue;
 		acl = container_of(ptr, struct tomoyo_mount_acl, head);
-		if (acl->is_deleted ||
-		    !tomoyo_compare_number_union(flags, &acl->flags) ||
+		if (!tomoyo_compare_number_union(flags, &acl->flags) ||
 		    !tomoyo_compare_name_union(&rtype, &acl->fs_type) ||
 		    !tomoyo_compare_name_union(&rdir, &acl->dir_name) ||
 		    (need_dev &&
@@ -259,6 +258,18 @@ int tomoyo_mount_permission(char *dev_name, struct path *path, char *type,
 	return error;
 }
 
+static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
+				  const struct tomoyo_acl_info *b)
+{
+	const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head);
+	const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head);
+	return tomoyo_is_same_acl_head(&p1->head, &p2->head) &&
+		tomoyo_is_same_name_union(&p1->dev_name, &p2->dev_name) &&
+		tomoyo_is_same_name_union(&p1->dir_name, &p2->dir_name) &&
+		tomoyo_is_same_name_union(&p1->fs_type, &p2->fs_type) &&
+		tomoyo_is_same_number_union(&p1->flags, &p2->flags);
+}
+
 /**
  * tomoyo_write_mount_policy - Write "struct tomoyo_mount_acl" list.
  *
@@ -267,11 +278,12 @@ int tomoyo_mount_permission(char *dev_name, struct path *path, char *type,
  * @is_delete: True if it is a delete request.
  *
  * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
  */
 int tomoyo_write_mount_policy(char *data, struct tomoyo_domain_info *domain,
 			      const bool is_delete)
 {
-	struct tomoyo_acl_info *ptr;
 	struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
 	int error = is_delete ? -ENOENT : -ENOMEM;
 	char *w[4];
@@ -282,27 +294,8 @@ int tomoyo_write_mount_policy(char *data, struct tomoyo_domain_info *domain,
 	    !tomoyo_parse_name_union(w[2], &e.fs_type) ||
 	    !tomoyo_parse_number_union(w[3], &e.flags))
 		goto out;
-	if (mutex_lock_interruptible(&tomoyo_policy_lock))
-		goto out;
-	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
-		struct tomoyo_mount_acl *acl =
-			container_of(ptr, struct tomoyo_mount_acl, head);
-		if (!tomoyo_is_same_mount_acl(acl, &e))
-			continue;
-		acl->is_deleted = is_delete;
-		error = 0;
-		break;
-	}
-	if (!is_delete && error) {
-		struct tomoyo_mount_acl *entry =
-			tomoyo_commit_ok(&e, sizeof(e));
-		if (entry) {
-			list_add_tail_rcu(&entry->head.list,
-					  &domain->acl_info_list);
-			error = 0;
-		}
-	}
-	mutex_unlock(&tomoyo_policy_lock);
+	error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
+				     tomoyo_same_mount_acl, NULL);
  out:
 	tomoyo_put_name_union(&e.dev_name);
 	tomoyo_put_name_union(&e.dir_name);

security/tomoyo/util.c

@@ -911,6 +911,8 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
 	if (!domain)
 		return true;
 	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
+		if (!ptr->is_deleted)
+			continue;
 		switch (ptr->type) {
 			u16 perm;
 			u8 i;
@@ -944,9 +946,7 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
 				if (perm & (1 << i))
 					count++;
 			break;
-		case TOMOYO_TYPE_MOUNT_ACL:
-			if (!container_of(ptr, struct tomoyo_mount_acl, head)->
-			    is_deleted)
+		default:
 			count++;
 		}
 	}