Cache hashed passphrase in RADIUS-based PSK delivery

Instead of copying the full struct hostapd_sta_wpa_psk_short, share the
existing entry and use reference counting to check when it needs to be
freed. This allows caching of PSKs derived from passphrases to avoid
having to perform the heavy hashing operation multiple times.

Signed-off-by: Michael Braun <michael-dev@fami-braun.de>

diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index 90405b4e3d737c589adc2a1ac27c8c966a215d8f..492df6cc8fdcffecf9191cba35e144f0b9d2d6df 100644 (file)
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -134,6 +134,7 @@ struct hostapd_sta_wpa_psk_short {
        unsigned int is_passphrase:1;
        u8 psk[PMK_LEN];
        char passphrase[MAX_PASSPHRASE_LEN + 1];
+       int ref; /* (number of references held) - 1 */
 };
 
 struct hostapd_wpa_psk {

diff --git a/src/ap/ieee802_11_auth.c b/src/ap/ieee802_11_auth.c
index 6afdc5db2ed6eecb42de0a14adc90587bad995dd..1ed8e7f471e55a4cf81cbbc7a53e6e604d859081 100644 (file)
--- a/src/ap/ieee802_11_auth.c
+++ b/src/ap/ieee802_11_auth.c
@@ -76,23 +76,13 @@ static void hostapd_acl_cache_free(struct hostapd_cached_radius_acl *acl_cache)
 static void copy_psk_list(struct hostapd_sta_wpa_psk_short **psk,
                          struct hostapd_sta_wpa_psk_short *src)
 {
-       struct hostapd_sta_wpa_psk_short **copy_to;
-       struct hostapd_sta_wpa_psk_short *copy_from;
-
-       /* Copy PSK linked list */
-       copy_to = psk;
-       copy_from = src;
-       while (copy_from && copy_to) {
-               *copy_to = os_zalloc(sizeof(struct hostapd_sta_wpa_psk_short));
-               if (*copy_to == NULL)
-                       break;
-               os_memcpy(*copy_to, copy_from,
-                         sizeof(struct hostapd_sta_wpa_psk_short));
-               copy_from = copy_from->next;
-               copy_to = &((*copy_to)->next);
-       }
-       if (copy_to)
-               *copy_to = NULL;
+       if (!psk)
+               return;
+
+       if (src)
+               src->ref++;
+
+       *psk = src;
 }
 
 
@@ -667,6 +657,12 @@ void hostapd_acl_deinit(struct hostapd_data *hapd)
 
 void hostapd_free_psk_list(struct hostapd_sta_wpa_psk_short *psk)
 {
+       if (psk && psk->ref) {
+               /* This will be freed when the last reference is dropped. */
+               psk->ref--;
+               return;
+       }
+
        while (psk) {
                struct hostapd_sta_wpa_psk_short *prev = psk;
                psk = psk->next;