net: port over u80211

kernel-src/io/net/u80211/src/bss_cache.c

@@ -0,0 +1,157 @@
+#include <stddef.h>
+
+#include <u80211/bss_cache.h>
+#include <u80211/kernel_interface.h>
+#include <u80211/rbtree.h>
+#include <u80211/status.h>
+#include <u80211/util.h>
+
+static int mac_compare(u80211_mac_address_t *a, u80211_mac_address_t *b) {
+	for (size_t i = 0; i < sizeof(a->bytes); i++) {
+		if (a->bytes[i] < b->bytes[i])
+			return -1;
+		if (a->bytes[i] > b->bytes[i])
+			return 1;
+	}
+
+	return 0;
+}
+
+static int rbtree_mac_compare(u80211_rbtree_t *a, u80211_rbtree_t *b) {
+	u80211_ap_t *ap_a = container_of(a, u80211_ap_t, cache_node);
+	u80211_ap_t *ap_b = container_of(b, u80211_ap_t, cache_node);
+
+	return mac_compare(&ap_a->mac_address, &ap_b->mac_address);
+}
+
+static int rbtree_value_compare(void *a, u80211_rbtree_t *b) {
+	u80211_ap_t *ap_b = container_of(b, u80211_ap_t, cache_node);
+
+	return mac_compare(a, &ap_b->mac_address);
+}
+
+int u80211_bss_cache_init(bss_cache_t *cache) {
+	cache->root = NULL;
+	cache->entry_count = 0;
+	cache->rwlock = u80211_kernel_allocate_rwlock();
+	if (unlikely(cache->rwlock == NULL))
+		return U80211_STATUS_ENOMEM;
+
+	return U80211_STATUS_SUCCESS;
+}
+
+void u80211_bss_cache_deinit(bss_cache_t *cache) {
+	u80211_kernel_acquire_rwlock_exclusive(cache->rwlock);
+
+	u80211_rbtree_t *iterator = cache->root == NULL ? NULL : u80211_rbtree_first(cache->root);
+	while (iterator != NULL) {
+		u80211_rbtree_t *next = u80211_rbtree_successor(iterator);
+		u80211_ap_t *ap = container_of(iterator, u80211_ap_t, cache_node);
+
+		u80211_rbtree_remove(&cache->root, iterator);
+		--cache->entry_count;
+		u80211_ap_release(ap);
+		iterator = next;
+	}
+
+	u80211_kernel_release_rwlock_exclusive(cache->rwlock);
+	u80211_kernel_free_rwlock(cache->rwlock);
+	cache->rwlock = NULL;
+	cache->root = NULL;
+}
+
+void u80211_bss_cache_purge(bss_cache_t *cache) {
+	u80211_kernel_acquire_rwlock_exclusive(cache->rwlock);
+
+	u80211_rbtree_t *iterator = cache->root == NULL ? NULL : u80211_rbtree_first(cache->root);
+	while (iterator != NULL) {
+		u80211_rbtree_t *next = u80211_rbtree_successor(iterator);
+
+		u80211_ap_t *ap = container_of(iterator, u80211_ap_t, cache_node);
+		if (__atomic_load_n(&ap->refcount, __ATOMIC_RELAXED) == 1) {
+			u80211_rbtree_remove(&cache->root, iterator);
+			--cache->entry_count;
+			u80211_ap_release(ap);
+		}
+
+		iterator = next;
+	}
+
+	u80211_kernel_release_rwlock_exclusive(cache->rwlock);
+}
+
+void u80211_bss_cache_insert(bss_cache_t *cache, u80211_ap_t *ap) {
+	u80211_kernel_acquire_rwlock_exclusive(cache->rwlock);
+
+	u80211_rbtree_t *node = u80211_rbtree_lookup(cache->root, &ap->mac_address, rbtree_value_compare);
+	if (node != NULL) {
+		u80211_kernel_release_rwlock_exclusive(cache->rwlock);
+		return;
+	}
+
+	u80211_rbtree_insert(&cache->root, &ap->cache_node, rbtree_mac_compare);
+	u80211_ap_hold(ap);
+	++cache->entry_count;
+
+	u80211_kernel_release_rwlock_exclusive(cache->rwlock);
+}
+
+void u80211_bss_cache_remove(bss_cache_t *cache, u80211_mac_address_t *mac) {
+	u80211_kernel_acquire_rwlock_exclusive(cache->rwlock);
+
+	u80211_rbtree_t *node = u80211_rbtree_lookup(cache->root, mac, rbtree_value_compare);
+	if (node == NULL) {
+		u80211_kernel_release_rwlock_exclusive(cache->rwlock);
+		return;
+	}
+
+	u80211_rbtree_remove(&cache->root, node);
+	--cache->entry_count;
+
+	u80211_ap_t *ap = container_of(node, u80211_ap_t, cache_node);
+	u80211_ap_release(ap);
+
+	u80211_kernel_release_rwlock_exclusive(cache->rwlock);
+}
+
+u80211_ap_t *u80211_bss_cache_find(bss_cache_t *cache, u80211_mac_address_t *mac) {
+	u80211_kernel_acquire_rwlock_shared(cache->rwlock);
+
+	u80211_rbtree_t *node = u80211_rbtree_lookup(cache->root, mac, rbtree_value_compare);
+	if (node == NULL) {
+		u80211_kernel_release_rwlock_shared(cache->rwlock);
+		return NULL;
+	}
+
+	u80211_ap_t *ap = container_of(node, u80211_ap_t, cache_node);
+	u80211_ap_hold(ap);
+
+	u80211_kernel_release_rwlock_shared(cache->rwlock);
+
+	return ap;
+}
+
+size_t u80211_bss_cache_get_aps(bss_cache_t *cache, u80211_ap_t **buffer, size_t capacity) {
+	u80211_kernel_acquire_rwlock_shared(cache->rwlock);
+
+	size_t count = 0;
+	u80211_rbtree_t *iterator = cache->root == NULL ? NULL : u80211_rbtree_first(cache->root);
+	while (iterator != NULL && count < capacity) {
+		u80211_ap_t *ap = container_of(iterator, u80211_ap_t, cache_node);
+		u80211_ap_hold(ap);
+		buffer[count++] = ap;
+		iterator = u80211_rbtree_successor(iterator);
+	}
+
+	u80211_kernel_release_rwlock_shared(cache->rwlock);
+
+	return count;
+}
+
+size_t u80211_bss_cache_get_count(bss_cache_t *cache) {
+	u80211_kernel_acquire_rwlock_shared(cache->rwlock);
+	size_t count = cache->entry_count;
+	u80211_kernel_release_rwlock_shared(cache->rwlock);
+
+	return count;
+}