kernel/proc: `process_handle_get` for safely accepting handle ids

1 files changed, 9 insertions, 0 deletions

diff --git a/src/kernel/proc.c b/src/kernel/proc.c
index 79c4ed7..39f9e1f 100644
--- a/src/kernel/proc.c
+++ b/src/kernel/proc.c
@@ -208,6 +208,15 @@ handle_t process_find_handle(struct process *proc, handle_t start_at) {
 	return handle;
 }
 
+struct handle*
+process_handle_get(struct process *p, handle_t id, enum handle_type type) {
+	struct handle *h;
+	if (id < 0 || id >= HANDLE_MAX) return NULL;
+	h = p->handles[id];
+	if (h == NULL || h->type != type) return NULL;
+	return h;
+}
+
 void process_transition(struct process *p, enum process_state state) {
 	enum process_state last = p->state;
 	p->state = state;