From c52d913f20ca8b58973037caf260c90661f5fb52 Mon Sep 17 00:00:00 2001
From: James Prestwood <prestwoj@gmail.com>
Date: Thu, 13 Feb 2025 12:18:14 -0800
Subject: [PATCH] pmksa: add driver callbacks and pmksa_cache_free

In order to support fullmac drivers the PMKSA entries must be added
and removed from the kernel. To accomplish this a set of driver
callbacks will be added to the PMKSA module. In addition a new
pmksa_cache_free API will be added whos only purpose is to handle
the removal from the kernel.
---
 src/pmksa.c | 38 ++++++++++++++++++++++++++++++++++++--
 src/pmksa.h |  9 +++++++++
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/pmksa.c b/src/pmksa.c
index bb539b85..a50c8208 100644
--- a/src/pmksa.c
+++ b/src/pmksa.c
@@ -40,6 +40,9 @@
 
 static uint64_t dot11RSNAConfigPMKLifetime = 43200ULL * L_USEC_PER_SEC;
 static uint32_t pmksa_cache_capacity = 255;
+static pmksa_cache_add_func_t driver_add;
+static pmksa_cache_remove_func_t driver_remove;
+static pmksa_cache_flush_func_t driver_flush;
 
 struct min_heap {
 	struct pmksa **data;
@@ -142,7 +145,7 @@ int pmksa_cache_put(struct pmksa *pmksa)
 	l_debug("Adding entry with PMKID: "PMKID, PMKID_STR(pmksa->pmkid));
 
 	if (cache.used == cache.capacity) {
-		l_free(cache.data[0]);
+		pmksa_cache_free(cache.data[0]);
 		cache.data[0] = pmksa;
 		__minheap_sift_down(cache.data, cache.used, 0, &ops);
 		return 0;
@@ -152,6 +155,9 @@ int pmksa_cache_put(struct pmksa *pmksa)
 	__minheap_sift_up(cache.data, cache.used, &ops);
 	cache.used += 1;
 
+	if (driver_add)
+		driver_add(pmksa);
+
 	return 0;
 }
 
@@ -167,7 +173,7 @@ int pmksa_cache_expire(uint64_t cutoff)
 
 	for (i = 0; i < used; i++) {
 		if (cache.data[i]->expiration <= cutoff) {
-			l_free(cache.data[i]);
+			pmksa_cache_free(cache.data[i]);
 			continue;
 		}
 
@@ -190,11 +196,30 @@ int pmksa_cache_flush(void)
 {
 	uint32_t i;
 
+	/*
+	 * The driver flush operation is done via a single kernel API call which
+	 * is why below we use l_free instead of pmksa_cache_free as to not
+	 * induce a DEL_PMKSA kernel call for each entry.
+	 */
+	if (driver_flush)
+		driver_flush();
+
 	for (i = 0; i < cache.used; i++)
 		l_free(cache.data[i]);
 
 	memset(cache.data, 0, cache.capacity * sizeof(struct pmksa *));
 	cache.used = 0;
+
+	return 0;
+}
+
+int pmksa_cache_free(struct pmksa *pmksa)
+{
+	if (driver_remove)
+		driver_remove(pmksa);
+
+	l_free(pmksa);
+
 	return 0;
 }
 
@@ -217,6 +242,15 @@ void __pmksa_set_config(const struct l_settings *config)
 					&pmksa_cache_capacity);
 }
 
+void __pmksa_set_driver_callbacks(pmksa_cache_add_func_t add,
+					pmksa_cache_remove_func_t remove,
+					pmksa_cache_flush_func_t flush)
+{
+	driver_add = add;
+	driver_remove = remove;
+	driver_flush = flush;
+}
+
 static int pmksa_init(void)
 {
 	cache.capacity = pmksa_cache_capacity;
diff --git a/src/pmksa.h b/src/pmksa.h
index 67879309..6a624504 100644
--- a/src/pmksa.h
+++ b/src/pmksa.h
@@ -32,6 +32,10 @@ struct pmksa {
 	size_t pmk_len;
 };
 
+typedef void (*pmksa_cache_add_func_t)(const struct pmksa *pmksa);
+typedef void (*pmksa_cache_remove_func_t)(const struct pmksa *pmksa);
+typedef void (*pmksa_cache_flush_func_t)(void);
+
 struct pmksa **__pmksa_cache_get_all(uint32_t *out_n_entries);
 
 struct pmksa *pmksa_cache_get(const uint8_t spa[static 6],
@@ -41,6 +45,11 @@ struct pmksa *pmksa_cache_get(const uint8_t spa[static 6],
 int pmksa_cache_put(struct pmksa *pmksa);
 int pmksa_cache_expire(uint64_t cutoff);
 int pmksa_cache_flush(void);
+int pmksa_cache_free(struct pmksa *pmksa);
 
 uint64_t pmksa_lifetime(void);
 void __pmksa_set_config(const struct l_settings *config);
+
+void __pmksa_set_driver_callbacks(pmksa_cache_add_func_t add,
+					pmksa_cache_remove_func_t remove,
+					pmksa_cache_flush_func_t flush);