mac80211: fils: use cfg80211_find_ext_elem()

Replace the use of cfg80211_find_ext_ie() with the more
structured cfg80211_find_ext_elem().

Link: https://lore.kernel.org/r/20210930131130.17ecf37f0605.I853c2f9c2117a713deca9b8deb3552796d98ffac@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/fils_aead.c b/net/mac80211/fils_aead.c
index a13ae14..e1d4cfd 100644 (file)
--- a/net/mac80211/fils_aead.c
+++ b/net/mac80211/fils_aead.c
@@ -219,7 +219,8 @@ int fils_encrypt_assoc_req(struct sk_buff *skb,
 {
        struct ieee80211_mgmt *mgmt = (void *)skb->data;
        u8 *capab, *ies, *encr;
-       const u8 *addr[5 + 1], *session;
+       const u8 *addr[5 + 1];
+       const struct element *session;
        size_t len[5 + 1];
        size_t crypt_len;
 
@@ -231,12 +232,12 @@ int fils_encrypt_assoc_req(struct sk_buff *skb,
                ies = mgmt->u.assoc_req.variable;
        }
 
-       session = cfg80211_find_ext_ie(WLAN_EID_EXT_FILS_SESSION,
-                                      ies, skb->data + skb->len - ies);
-       if (!session || session[1] != 1 + 8)
+       session = cfg80211_find_ext_elem(WLAN_EID_EXT_FILS_SESSION,
+                                        ies, skb->data + skb->len - ies);
+       if (!session || session->datalen != 1 + 8)
                return -EINVAL;
        /* encrypt after FILS Session element */
-       encr = (u8 *)session + 2 + 1 + 8;
+       encr = (u8 *)session->data + 1 + 8;
 
        /* AES-SIV AAD vectors */
 
@@ -270,7 +271,8 @@ int fils_decrypt_assoc_resp(struct ieee80211_sub_if_data *sdata,
 {
        struct ieee80211_mgmt *mgmt = (void *)frame;
        u8 *capab, *ies, *encr;
-       const u8 *addr[5 + 1], *session;
+       const u8 *addr[5 + 1];
+       const struct element *session;
        size_t len[5 + 1];
        int res;
        size_t crypt_len;
@@ -280,16 +282,16 @@ int fils_decrypt_assoc_resp(struct ieee80211_sub_if_data *sdata,
 
        capab = (u8 *)&mgmt->u.assoc_resp.capab_info;
        ies = mgmt->u.assoc_resp.variable;
-       session = cfg80211_find_ext_ie(WLAN_EID_EXT_FILS_SESSION,
-                                      ies, frame + *frame_len - ies);
-       if (!session || session[1] != 1 + 8) {
+       session = cfg80211_find_ext_elem(WLAN_EID_EXT_FILS_SESSION,
+                                        ies, frame + *frame_len - ies);
+       if (!session || session->datalen != 1 + 8) {
                mlme_dbg(sdata,
                         "No (valid) FILS Session element in (Re)Association Response frame from %pM",
                         mgmt->sa);
                return -EINVAL;
        }
        /* decrypt after FILS Session element */
-       encr = (u8 *)session + 2 + 1 + 8;
+       encr = (u8 *)session->data + 1 + 8;
 
        /* AES-SIV AAD vectors */