On Wed, Mar 02, 2016 at 06:50:26PM +0200, Eliad Peller wrote:
> There is a race condition in which wpa_supplicant might
> receive the EAPOL-Start frame (from the just-associated
> station) before the tx completion of the assoc response.
What is the point of that wpa_supplicant reference here? Isn't this
supposed to apply to AP side functionality? In other words, this applies
to both hostapd and wpa_supplicant (if using AP mode).
> This in turn will cause the EAPOL-Start frame to get
> dropped, and potentially failing the connection.
What kind of connection fails due to one EAPOL-Start frame being
dropped?
> Solve this by saving EAPOLs from authenticated-but-not-
> associated stations, and handling them during the assoc
> response tx completion processing.
I'm probably fine with this change in general, but couple of comments on
the implementation:
> diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
> @@ -2782,6 +2782,25 @@ static void handle_assoc_cb(struct hostapd_data *hapd,
> + if (sta->pending_eapol_rx) {
> + struct os_reltime now, age;
> + os_get_reltime(&now);
> + os_reltime_sub(&now, &sta->pending_eapol_rx_time, &age);
> + if (age.sec == 0 && age.usec < 200000 &&
> + os_memcmp(sta->pending_eapol_rx_src,
> + mgmt->da, ETH_ALEN) == 0) {
What is the point of comparing sta->pending_eapol_rx_src to mgmt->da?
This is after sta = ap_get_sta(hapd, mgmt->da) and there is not really
any possibility for these to be different..
> diff --git a/src/ap/ieee802_1x.c b/src/ap/ieee802_1x.c
> @@ -891,6 +891,18 @@ void ieee802_1x_receive(struct hostapd_data *hapd, const u8 *sa, const u8 *buf,
> + if (sta && (sta->flags & WLAN_STA_AUTH)) {
> + wpa_printf(MSG_DEBUG, "Saving EAPOL for later use");
> + wpabuf_free(sta->pending_eapol_rx);
> + sta->pending_eapol_rx = wpabuf_alloc_copy(buf, len);
> + if (sta->pending_eapol_rx) {
> + os_get_reltime(&sta->pending_eapol_rx_time);
> + os_memcpy(sta->pending_eapol_rx_src, sa,
> + ETH_ALEN);
Similarly here.. Why is sa copied into sta->pending_eapol_rx_src when
sta->addr already contains the MAC address of the STA which is sa here
after sta = ap_get_sta(hapd, sa).
> diff --git a/src/ap/sta_info.h b/src/ap/sta_info.h
> @@ -113,6 +113,10 @@ struct sta_info {
> + struct wpabuf *pending_eapol_rx;
> + struct os_reltime pending_eapol_rx_time;
> + u8 pending_eapol_rx_src[ETH_ALEN];
pending_eapol_rx_src should go away. One allocation could be used to
store both the pending frame and pending_eapol_rx_time to reduce the
size of struct sta_info due to this type of short-lived data.
--
Jouni Malinen PGP id EFC895FA
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