[RFC PATCH v4 01/15] landlock: access mask renaming

[Konstantin Meskhidze <konstantin.meskhidze@huawei.com>]

Currently Landlock supports filesystem
restrictions. To support network type rules,
this modification extends and renames
ruleset's access masks.

Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
---

Changes since v3:
* Split commit.

---
 security/landlock/fs.c       |  4 ++--
 security/landlock/ruleset.c  | 18 +++++++++---------
 security/landlock/ruleset.h  |  8 ++++----
 security/landlock/syscalls.c |  6 +++---
 4 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index 97b8e421f617..d727bdab7840 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -163,7 +163,7 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset,
 		return -EINVAL;

 	/* Transforms relative access rights to absolute ones. */
-	access_rights |= LANDLOCK_MASK_ACCESS_FS & ~ruleset->fs_access_masks[0];
+	access_rights |= LANDLOCK_MASK_ACCESS_FS & ~ruleset->access_masks[0];
 	object = get_inode_object(d_backing_inode(path->dentry));
 	if (IS_ERR(object))
 		return PTR_ERR(object);
@@ -252,7 +252,7 @@ static int check_access_path(const struct landlock_ruleset *const domain,
 	/* Saves all layers handling a subset of requested accesses. */
 	layer_mask = 0;
 	for (i = 0; i < domain->num_layers; i++) {
-		if (domain->fs_access_masks[i] & access_request)
+		if (domain->access_masks[i] & access_request)
 			layer_mask |= BIT_ULL(i);
 	}
 	/* An access request not handled by the domain is allowed. */
diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
index ec72b9262bf3..78341a0538de 100644
--- a/security/landlock/ruleset.c
+++ b/security/landlock/ruleset.c
@@ -28,7 +28,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers)
 {
 	struct landlock_ruleset *new_ruleset;

-	new_ruleset = kzalloc(struct_size(new_ruleset, fs_access_masks,
+	new_ruleset = kzalloc(struct_size(new_ruleset, access_masks,
 				num_layers), GFP_KERNEL_ACCOUNT);
 	if (!new_ruleset)
 		return ERR_PTR(-ENOMEM);
@@ -39,21 +39,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers)
 	/*
 	 * hierarchy = NULL
 	 * num_rules = 0
-	 * fs_access_masks[] = 0
+	 * access_masks[] = 0
 	 */
 	return new_ruleset;
 }

-struct landlock_ruleset *landlock_create_ruleset(const u32 fs_access_mask)
+struct landlock_ruleset *landlock_create_ruleset(const u32 access_mask)
 {
 	struct landlock_ruleset *new_ruleset;

 	/* Informs about useless ruleset. */
-	if (!fs_access_mask)
+	if (!access_mask)
 		return ERR_PTR(-ENOMSG);
 	new_ruleset = create_ruleset(1);
 	if (!IS_ERR(new_ruleset))
-		new_ruleset->fs_access_masks[0] = fs_access_mask;
+		new_ruleset->access_masks[0] = access_mask;
 	return new_ruleset;
 }

@@ -116,7 +116,7 @@ static void build_check_ruleset(void)
 		.num_rules = ~0,
 		.num_layers = ~0,
 	};
-	typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0;
+	typeof(ruleset.access_masks[0]) fs_access_mask = ~0;

 	BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES);
 	BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS);
@@ -279,7 +279,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst,
 		err = -EINVAL;
 		goto out_unlock;
 	}
-	dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0];
+	dst->access_masks[dst->num_layers - 1] = src->access_masks[0];

 	/* Merges the @src tree. */
 	rbtree_postorder_for_each_entry_safe(walker_rule, next_rule,
@@ -337,8 +337,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent,
 		goto out_unlock;
 	}
 	/* Copies the parent layer stack and leaves a space for the new layer. */
-	memcpy(child->fs_access_masks, parent->fs_access_masks,
-			flex_array_size(parent, fs_access_masks, parent->num_layers));
+	memcpy(child->access_masks, parent->access_masks,
+			flex_array_size(parent, access_masks, parent->num_layers));

 	if (WARN_ON_ONCE(!parent->hierarchy)) {
 		err = -EINVAL;
diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
index 2d3ed7ec5a0a..32d90ce72428 100644
--- a/security/landlock/ruleset.h
+++ b/security/landlock/ruleset.h
@@ -97,7 +97,7 @@ struct landlock_ruleset {
 		 * section.  This is only used by
 		 * landlock_put_ruleset_deferred() when @usage reaches zero.
 		 * The fields @lock, @usage, @num_rules, @num_layers and
-		 * @fs_access_masks are then unused.
+		 * @access_masks are then unused.
 		 */
 		struct work_struct work_free;
 		struct {
@@ -124,7 +124,7 @@ struct landlock_ruleset {
 			 */
 			u32 num_layers;
 			/**
-			 * @fs_access_masks: Contains the subset of filesystem
+			 * @access_masks: Contains the subset of filesystem
 			 * actions that are restricted by a ruleset.  A domain
 			 * saves all layers of merged rulesets in a stack
 			 * (FAM), starting from the first layer to the last
@@ -135,12 +135,12 @@ struct landlock_ruleset {
 			 * layers are set once and never changed for the
 			 * lifetime of the ruleset.
 			 */
-			u16 fs_access_masks[];
+			u32 access_masks[];
 		};
 	};
 };

-struct landlock_ruleset *landlock_create_ruleset(const u32 fs_access_mask);
+struct landlock_ruleset *landlock_create_ruleset(const u32 access_mask);

 void landlock_put_ruleset(struct landlock_ruleset *const ruleset);
 void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset);
diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
index 32396962f04d..f1d86311df7e 100644
--- a/security/landlock/syscalls.c
+++ b/security/landlock/syscalls.c
@@ -341,10 +341,10 @@ SYSCALL_DEFINE4(landlock_add_rule,
 	}
 	/*
 	 * Checks that allowed_access matches the @ruleset constraints
-	 * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits).
+	 * (ruleset->access_masks[0] is automatically upgraded to 64-bits).
 	 */
-	if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) !=
-			ruleset->fs_access_masks[0]) {
+	if ((path_beneath_attr.allowed_access | ruleset->access_masks[0]) !=
+			ruleset->access_masks[0]) {
 		err = -EINVAL;
 		goto out_put_ruleset;
 	}
--
2.25.1