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[3/9,v4] libsepol/cil: Add cil_tree_node_remove function

Message ID 20230809210157.112275-4-jwcart2@gmail.com (mailing list archive)
State Accepted
Commit 9d5ca92be190
Delegated to: Petr Lautrbach
Headers show
Series Add CIL Deny Rule | expand

Commit Message

James Carter Aug. 9, 2023, 9:01 p.m. UTC 
Add the function cil_tree_node_remove() which takes a node pointer
as an input, finds the parent, walks the list of nodes to the node
prior to the given node, updates that node's next pointer to remove
the given node from the tree, and then destroys the node.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/cil/src/cil_tree.c | 35 +++++++++++++++++++++++++++++++++++
 libsepol/cil/src/cil_tree.h |  1 +
 2 files changed, 36 insertions(+)
diff mbox series

Patch

diff --git a/libsepol/cil/src/cil_tree.c b/libsepol/cil/src/cil_tree.c
index 6376c208..1155e311 100644
--- a/libsepol/cil/src/cil_tree.c
+++ b/libsepol/cil/src/cil_tree.c
@@ -248,6 +248,41 @@  void cil_tree_node_destroy(struct cil_tree_node **node)
 	*node = NULL;
 }
 
+void cil_tree_node_remove(struct cil_tree_node *node)
+{
+	struct cil_tree_node *parent, *curr;
+
+	if (node == NULL || node->parent == NULL) {
+		return;
+	}
+
+	parent = node->parent;
+
+	if (parent->cl_head == node) {
+		if (parent->cl_tail == node) {
+			parent->cl_tail = NULL;
+		}
+		parent->cl_head = node->next;
+		cil_tree_node_destroy(&node);
+		return;
+	}
+
+	curr = parent->cl_head;
+	while (curr && curr->next != node) {
+		curr = curr->next;
+	}
+
+	if (curr == NULL) {
+		return;
+	}
+
+	if (parent->cl_tail == node) {
+		parent->cl_tail = curr;
+	}
+	curr->next = node->next;
+	cil_tree_node_destroy(&node);
+}
+
 /* Perform depth-first walk of the tree
    Parameters:
    start_node:          root node to start walking from
diff --git a/libsepol/cil/src/cil_tree.h b/libsepol/cil/src/cil_tree.h
index 5a98da55..cb6a0d24 100644
--- a/libsepol/cil/src/cil_tree.h
+++ b/libsepol/cil/src/cil_tree.h
@@ -63,6 +63,7 @@  void cil_tree_children_destroy(struct cil_tree_node *node);
 
 void cil_tree_node_init(struct cil_tree_node **node);
 void cil_tree_node_destroy(struct cil_tree_node **node);
+void cil_tree_node_remove(struct cil_tree_node *node);
 
 //finished values
 #define CIL_TREE_SKIP_NOTHING	0