[PATCH v4 10/15] driver_nl80211: use nl80211 for mgmt TX/RX in AP mode

Jouni Malinen j at w1.fi
Sat Dec 3 13:39:40 EST 2011


On Mon, Nov 21, 2011 at 11:41:53AM +0100, Johannes Berg wrote:
> To achieve this, multiple things are needed:
>  1) since hostapd needs to handle *all* action frames,
>     make the normal registration only when in a non-AP
>     mode, to be able to do this use the new socket
>  2) store the frequency in each BSS to be able to give
>     the right frequency to nl80211's mgmt-tx operation
>  3) make TX status processing reject non-matched cookie
>     only in non-AP mode

Hmm.. This makes some P2P use cases fail with a kernel that supports the
new functionality. At least group formation without separate group
interface failed on the GO (hwsim) with frame registration:

1322937312.602354: nl80211: Setup AP operations for P2P group (GO)
1322937312.602372: nl80211: Set mode ifindex 3 iftype 9 (P2P_GO)
1322937312.603544: nl80211: Register frame command failed (type=64): ret=-114 (Operation already in progress)
1322937312.603596: nl80211: Register frame match - hexdump(len=0): [NULL]
1322937312.603753: wlan0: Failed to start AP functionality

Just starting up an autonomous GO did not seem to have this issue. In
addition, older kernel without the new functionality did not hit this,
so I would assume that somehow this patch ends up registering to receive
frames multiple times for AP mode.

There were couple of conflicts in the patches, so I'm included the
version that I used in the test below.

 
diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 20eb744..d8400b5 100644
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -194,7 +194,7 @@ struct i802_bss {
 
 	int freq;
 
-	struct nl80211_handles nl_preq;
+	struct nl80211_handles nl_preq, nl_mgmt;
 	struct nl_cb *nl_cb;
 };
 
@@ -238,6 +238,7 @@ struct wpa_driver_nl80211_data {
 	unsigned int device_ap_sme:1;
 	unsigned int poll_command_supported:1;
 	unsigned int data_tx_status:1;
+	unsigned int use_monitor:1;
 
 	u64 remain_on_chan_cookie;
 	u64 send_action_cookie;
@@ -978,26 +979,29 @@ static void mlme_event_mgmt(struct wpa_driver_nl80211_data *drv,
 }
 
 
-static void mlme_event_action_tx_status(struct wpa_driver_nl80211_data *drv,
-					struct nlattr *cookie, const u8 *frame,
-					size_t len, struct nlattr *ack)
+static void mlme_event_mgmt_tx_status(struct wpa_driver_nl80211_data *drv,
+				      struct nlattr *cookie, const u8 *frame,
+				      size_t len, struct nlattr *ack)
 {
 	union wpa_event_data event;
 	const struct ieee80211_hdr *hdr;
 	u16 fc;
-	u64 cookie_val;
 
-	if (!cookie)
-		return;
+	if (!is_ap_interface(drv->nlmode)) {
+		u64 cookie_val;
 
-	cookie_val = nla_get_u64(cookie);
-	wpa_printf(MSG_DEBUG, "nl80211: Action TX status: cookie=0%llx%s "
-		   "(ack=%d)",
-		   (long long unsigned int) cookie_val,
-		   cookie_val == drv->send_action_cookie ?
-		   " (match)" : " (unknown)", ack != NULL);
-	if (cookie_val != drv->send_action_cookie)
-		return;
+		if (!cookie)
+			return;
+
+		cookie_val = nla_get_u64(cookie);
+		wpa_printf(MSG_DEBUG, "nl80211: Action TX status:"
+			   " cookie=0%llx%s (ack=%d)",
+			   (long long unsigned int) cookie_val,
+			   cookie_val == drv->send_action_cookie ?
+			   " (match)" : " (unknown)", ack != NULL);
+		if (cookie_val != drv->send_action_cookie)
+			return;
+	}
 
 	hdr = (const struct ieee80211_hdr *) frame;
 	fc = le_to_host16(hdr->frame_control);
@@ -1142,8 +1146,8 @@ static void mlme_event(struct wpa_driver_nl80211_data *drv,
 		mlme_event_mgmt(drv, freq, nla_data(frame), nla_len(frame));
 		break;
 	case NL80211_CMD_FRAME_TX_STATUS:
-		mlme_event_action_tx_status(drv, cookie, nla_data(frame),
-					    nla_len(frame), ack);
+		mlme_event_mgmt_tx_status(drv, cookie, nla_data(frame),
+					  nla_len(frame), ack);
 		break;
 	case NL80211_CMD_UNPROT_DEAUTHENTICATE:
 		mlme_event_unprot_disconnect(drv, EVENT_UNPROT_DEAUTH,
@@ -1792,7 +1796,6 @@ static int process_drv_event(struct nl_msg *msg, void *arg)
 	case NL80211_CMD_ASSOCIATE:
 	case NL80211_CMD_DEAUTHENTICATE:
 	case NL80211_CMD_DISASSOCIATE:
-	case NL80211_CMD_FRAME:
 	case NL80211_CMD_FRAME_TX_STATUS:
 	case NL80211_CMD_UNPROT_DEAUTHENTICATE:
 	case NL80211_CMD_UNPROT_DISASSOCIATE:
@@ -1865,6 +1868,7 @@ static int process_drv_event(struct nl_msg *msg, void *arg)
 
 static int process_bss_event(struct nl_msg *msg, void *arg)
 {
+	struct i802_bss *bss = arg;
 	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
 	struct nlattr *tb[NL80211_ATTR_MAX + 1];
 
@@ -1872,6 +1876,13 @@ static int process_bss_event(struct nl_msg *msg, void *arg)
 		  genlmsg_attrlen(gnlh, 0), NULL);
 
 	switch (gnlh->cmd) {
+	case NL80211_CMD_FRAME:
+	case NL80211_CMD_FRAME_TX_STATUS:
+		mlme_event(bss->drv, gnlh->cmd, tb[NL80211_ATTR_FRAME],
+			   tb[NL80211_ATTR_MAC], tb[NL80211_ATTR_TIMED_OUT],
+			   tb[NL80211_ATTR_WIPHY_FREQ], tb[NL80211_ATTR_ACK],
+			   tb[NL80211_ATTR_COOKIE]);
+		break;
 	default:
 		wpa_printf(MSG_DEBUG, "nl80211: Ignored unknown event "
 			   "(cmd=%d)", gnlh->cmd);
@@ -2190,6 +2201,20 @@ static int wpa_driver_nl80211_capa(struct wpa_driver_nl80211_data *drv)
 	drv->poll_command_supported = info.poll_command_supported;
 	drv->data_tx_status = info.data_tx_status;
 
+	/*
+	 * If poll command is supported mac80211 is new enough to
+	 * have everything we need to not need monitor interfaces.
+	 */
+	drv->use_monitor = !info.poll_command_supported;
+
+	/*
+	 * If we aren't going to use monitor interfaces, but the
+	 * driver doesn't support data TX status, we won't get TX
+	 * status for EAPOL frames.
+	 */
+	if (!drv->use_monitor && !info.data_tx_status)
+		drv->capa.flags &= ~WPA_DRIVER_FLAGS_EAPOL_TX_STATUS;
+
 	return 0;
 }
 
@@ -2490,6 +2515,9 @@ static void * wpa_driver_nl80211_init(void *ctx, const char *ifname,
 			wpa_printf(MSG_DEBUG,
 				"nl80211: wifi status sockopt failed\n");
 			drv->data_tx_status = 0;
+			if (!drv->use_monitor)
+				drv->capa.flags &=
+					~WPA_DRIVER_FLAGS_EAPOL_TX_STATUS;
 		} else {
 			eloop_register_read_sock(drv->eapol_tx_sock,
 				wpa_driver_nl80211_handle_eapol_tx_status,
@@ -2510,10 +2538,11 @@ failed:
 }
 
 
-static int nl80211_register_frame(struct wpa_driver_nl80211_data *drv,
+static int nl80211_register_frame(struct i802_bss *bss,
 				  struct nl_handle *nl_handle,
 				  u16 type, const u8 *match, size_t match_len)
 {
+	struct wpa_driver_nl80211_data *drv = bss->drv;
 	struct nl_msg *msg;
 	int ret = -1;
 
@@ -2523,7 +2552,7 @@ static int nl80211_register_frame(struct wpa_driver_nl80211_data *drv,
 
 	nl80211_cmd(drv, msg, 0, NL80211_CMD_REGISTER_ACTION);
 
-	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
+	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, bss->ifindex);
 	NLA_PUT_U16(msg, NL80211_ATTR_FRAME_TYPE, type);
 	NLA_PUT(msg, NL80211_ATTR_FRAME_MATCH, match_len, match);
 
@@ -2544,46 +2573,72 @@ nla_put_failure:
 }
 
 
-static int nl80211_register_action_frame(struct wpa_driver_nl80211_data *drv,
+static int nl80211_alloc_mgmt_handle(struct i802_bss *bss)
+{
+	struct wpa_driver_nl80211_data *drv = bss->drv;
+
+	if (bss->nl_mgmt.handle) {
+		wpa_printf(MSG_DEBUG, "nl80211: Mgmt reporting "
+			   "already on!");
+		return -1;
+	}
+
+	if (nl_create_handles(&bss->nl_mgmt, drv->nl_cb, "mgmt"))
+		return -1;
+
+	eloop_register_read_sock(nl_socket_get_fd(bss->nl_mgmt.handle),
+				 wpa_driver_nl80211_event_receive, bss->nl_cb,
+				 bss->nl_mgmt.handle);
+
+	return 0;
+}
+
+
+static int nl80211_register_action_frame(struct i802_bss *bss,
 					 const u8 *match, size_t match_len)
 {
 	u16 type = (WLAN_FC_TYPE_MGMT << 2) | (WLAN_FC_STYPE_ACTION << 4);
-	return nl80211_register_frame(drv, drv->nl_event.handle,
+	return nl80211_register_frame(bss, bss->nl_mgmt.handle,
 				      type, match, match_len);
 }
 
 
-static int nl80211_register_action_frames(struct wpa_driver_nl80211_data *drv)
+static int nl80211_mgmt_subscribe_non_ap(struct i802_bss *bss)
 {
+	struct wpa_driver_nl80211_data *drv = bss->drv;
+
+	if (nl80211_alloc_mgmt_handle(bss))
+		return -1;
+
 #if defined(CONFIG_P2P) || defined(CONFIG_INTERWORKING)
 	/* GAS Initial Request */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x04\x0a", 2) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x04\x0a", 2) < 0)
 		return -1;
 	/* GAS Initial Response */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x04\x0b", 2) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x04\x0b", 2) < 0)
 		return -1;
 	/* GAS Comeback Request */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x04\x0c", 2) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x04\x0c", 2) < 0)
 		return -1;
 	/* GAS Comeback Response */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x04\x0d", 2) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x04\x0d", 2) < 0)
 		return -1;
 #endif /* CONFIG_P2P || CONFIG_INTERWORKING */
 #ifdef CONFIG_P2P
 	/* P2P Public Action */
-	if (nl80211_register_action_frame(drv,
+	if (nl80211_register_action_frame(bss,
 					  (u8 *) "\x04\x09\x50\x6f\x9a\x09",
 					  6) < 0)
 		return -1;
 	/* P2P Action */
-	if (nl80211_register_action_frame(drv,
+	if (nl80211_register_action_frame(bss,
 					  (u8 *) "\x7f\x50\x6f\x9a\x09",
 					  5) < 0)
 		return -1;
 #endif /* CONFIG_P2P */
 #ifdef CONFIG_IEEE80211W
 	/* SA Query Response */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x08\x01", 2) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x08\x01", 2) < 0)
 		return -1;
 #endif /* CONFIG_IEEE80211W */
 #ifdef CONFIG_TDLS
@@ -2596,20 +2651,68 @@ static int nl80211_register_action_frames(struct wpa_driver_nl80211_data *drv)
 #endif /* CONFIG_TDLS */
 
 	/* FT Action frames */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x06", 1) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x06", 1) < 0)
 		return -1;
 	else
 		drv->capa.key_mgmt |= WPA_DRIVER_CAPA_KEY_MGMT_FT |
 			WPA_DRIVER_CAPA_KEY_MGMT_FT_PSK;
 
 	/* WNM - BSS Transition Management Request */
-	if (nl80211_register_action_frame(drv, (u8 *) "\x0a\x07", 2) < 0)
+	if (nl80211_register_action_frame(bss, (u8 *) "\x0a\x07", 2) < 0)
 		return -1;
 
 	return 0;
 }
 
 
+static int nl80211_mgmt_subscribe_ap(struct i802_bss *bss)
+{
+	static const int stypes[] = {
+		WLAN_FC_STYPE_AUTH,
+		WLAN_FC_STYPE_ASSOC_REQ,
+		WLAN_FC_STYPE_REASSOC_REQ,
+		WLAN_FC_STYPE_DISASSOC,
+		WLAN_FC_STYPE_DEAUTH,
+		WLAN_FC_STYPE_ACTION,
+		WLAN_FC_STYPE_PROBE_REQ,
+/* Beacon doesn't work as mac80211 doesn't currently allow it, but it wouldn't
+ * really be the right thing anyway as it isn't per interface... Maybe just
+ * dump the scan results periodically for OLBC?
+ */
+//		WLAN_FC_STYPE_BEACON,
+	};
+	unsigned int i;
+
+	if (nl80211_alloc_mgmt_handle(bss))
+		return -1;
+
+	for (i = 0; i < sizeof(stypes) / sizeof(stypes[0]); i++) {
+		if (nl80211_register_frame(bss, bss->nl_mgmt.handle,
+					   (WLAN_FC_TYPE_MGMT << 2) |
+					   (stypes[i] << 4),
+					   NULL, 0) < 0) {
+			goto out_err;
+		}
+	}
+
+	return 0;
+
+out_err:
+	eloop_unregister_read_sock(nl_socket_get_fd(bss->nl_mgmt.handle));
+	nl_destroy_handles(&bss->nl_mgmt);
+	return -1;
+}
+
+
+static void nl80211_mgmt_unsubscribe(struct i802_bss *bss)
+{
+	if (bss->nl_mgmt.handle == NULL)
+		return;
+	eloop_unregister_read_sock(nl_socket_get_fd(bss->nl_mgmt.handle));
+	nl_destroy_handles(&bss->nl_mgmt);
+}
+
+
 static void wpa_driver_nl80211_send_rfkill(void *eloop_ctx, void *timeout_ctx)
 {
 	wpa_supplicant_event(timeout_ctx, EVENT_INTERFACE_DISABLED, NULL);
@@ -2663,16 +2766,6 @@ wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv)
 			       drv->addr))
 		return -1;
 
-	if (nl80211_register_action_frames(drv) < 0) {
-		wpa_printf(MSG_DEBUG, "nl80211: Failed to register Action "
-			   "frame processing - ignore for now");
-		/*
-		 * Older kernel versions did not support this, so ignore the
-		 * error for now. Some functionality may not be available
-		 * because of this.
-		 */
-	}
-
 	if (send_rfkill_event) {
 		eloop_register_timeout(0, 0, wpa_driver_nl80211_send_rfkill,
 				       drv, drv->ctx);
@@ -2766,6 +2859,7 @@ static void wpa_driver_nl80211_deinit(void *priv)
 
 	(void) linux_set_iface_flags(drv->global->ioctl_sock, bss->ifname, 0);
 	wpa_driver_nl80211_set_mode(bss, NL80211_IFTYPE_STATION);
+	nl80211_mgmt_unsubscribe(bss);
 
 	eloop_unregister_read_sock(nl_socket_get_fd(drv->nl_event.handle));
 	nl_destroy_handles(&drv->nl_event);
@@ -4344,9 +4438,9 @@ wpa_driver_nl80211_get_hw_feature_data(void *priv, u16 *num_modes, u16 *flags)
 }
 
 
-static int wpa_driver_nl80211_send_frame(struct wpa_driver_nl80211_data *drv,
-					 const void *data, size_t len,
-					 int encrypt, int noack)
+static int wpa_driver_nl80211_send_mntr(struct wpa_driver_nl80211_data *drv,
+					const void *data, size_t len,
+					int encrypt, int noack)
 {
 	__u8 rtap_hdr[] = {
 		0x00, 0x00, /* radiotap version */
@@ -4401,6 +4495,22 @@ static int wpa_driver_nl80211_send_frame(struct wpa_driver_nl80211_data *drv,
 }
 
 
+static int wpa_driver_nl80211_send_frame(struct i802_bss *bss,
+					 const void *data, size_t len,
+					 int encrypt, int noack)
+{
+	struct wpa_driver_nl80211_data *drv = bss->drv;
+	u64 cookie;
+
+	if (drv->use_monitor)
+		return wpa_driver_nl80211_send_mntr(drv, data, len,
+						    encrypt, noack);
+
+	return nl80211_send_frame_cmd(bss, bss->freq, 0, data, len,
+				      &cookie, 0, noack, 0);
+}
+
+
 static int wpa_driver_nl80211_send_mlme(void *priv, const u8 *data,
 					size_t data_len, int noack)
 {
@@ -4446,7 +4556,7 @@ static int wpa_driver_nl80211_send_mlme(void *priv, const u8 *data,
 			encrypt = 0;
 	}
 
-	return wpa_driver_nl80211_send_frame(drv, data, data_len, encrypt,
+	return wpa_driver_nl80211_send_frame(bss, data, data_len, encrypt,
 					     noack);
 }
 
@@ -5326,7 +5436,11 @@ static int nl80211_setup_ap(struct i802_bss *bss)
 {
 	struct wpa_driver_nl80211_data *drv = bss->drv;
 
-	if (!drv->device_ap_sme &&
+	if (!drv->device_ap_sme && !drv->use_monitor)
+		if (nl80211_mgmt_subscribe_ap(bss))
+			return -1;
+
+	if (!drv->device_ap_sme && drv->use_monitor &&
 	    nl80211_create_monitor_interface(drv) &&
 	    !drv->device_ap_sme)
 		return -1;
@@ -5348,8 +5462,11 @@ static void nl80211_teardown_ap(struct i802_bss *bss)
 
 	if (drv->device_ap_sme)
 		wpa_driver_nl80211_probe_req_report(bss, 0);
-	else
+	else if (drv->use_monitor)
 		nl80211_remove_monitor_interface(drv);
+	else
+		nl80211_mgmt_unsubscribe(bss);
+
 	bss->beacon_set = 0;
 }
 
@@ -5396,7 +5513,7 @@ static int wpa_driver_nl80211_hapd_send_eapol(
 	int res;
 	int qos = flags & WPA_STA_WMM;
 
-	if (drv->device_ap_sme || drv->data_tx_status)
+	if (drv->device_ap_sme || !drv->use_monitor)
 		return nl80211_send_eapol_data(bss, addr, data, data_len);
 
 	len = sizeof(*hdr) + (qos ? 2 : 0) + sizeof(rfc1042_header) + 2 +
@@ -5436,7 +5553,7 @@ static int wpa_driver_nl80211_hapd_send_eapol(
 	pos += 2;
 	memcpy(pos, data, data_len);
 
-	res = wpa_driver_nl80211_send_frame(drv, (u8 *) hdr, len, encrypt, 0);
+	res = wpa_driver_nl80211_send_frame(bss, (u8 *) hdr, len, encrypt, 0);
 	if (res < 0) {
 		wpa_printf(MSG_ERROR, "i802_send_eapol - packet len: %lu - "
 			   "failed: %d (%s)",
@@ -6083,14 +6200,22 @@ done:
 	}
 
 	if (is_ap_interface(nlmode)) {
+		nl80211_mgmt_unsubscribe(bss);
 		/* Setup additional AP mode functionality if needed */
 		if (nl80211_setup_ap(bss))
 			return -1;
 	} else if (was_ap) {
 		/* Remove additional AP mode functionality */
 		nl80211_teardown_ap(bss);
+	} else {
+		nl80211_mgmt_unsubscribe(bss);
 	}
 
+	if (!is_ap_interface(nlmode) &&
+	    nl80211_mgmt_subscribe_non_ap(bss) < 0)
+		wpa_printf(MSG_DEBUG, "nl80211: Failed to register Action "
+				"frame processing - ignore for now");
+
 	if (!ret && is_p2p_interface(drv->nlmode)) {
 		nl80211_disable_11b_rates(drv, drv->ifindex, 1);
 		drv->disabled_11b_rates = 1;
@@ -7254,14 +7379,14 @@ static int wpa_driver_nl80211_probe_req_report(void *priv, int report)
 	if (nl_create_handles(&bss->nl_preq, drv->global->nl_cb, "preq"))
 		return -1;
 
-	if (nl80211_register_frame(drv, bss->nl_preq.handle,
+	if (nl80211_register_frame(bss, bss->nl_preq.handle,
 				   (WLAN_FC_TYPE_MGMT << 2) |
 				   (WLAN_FC_STYPE_PROBE_REQ << 4),
 				   NULL, 0) < 0)
 		goto out_err;
 
 	eloop_register_read_sock(nl_socket_get_fd(bss->nl_preq.handle),
-				 wpa_driver_nl80211_event_receive, drv->nl_cb,
+				 wpa_driver_nl80211_event_receive, bss->nl_cb,
 				 bss->nl_preq.handle);
 
 	return 0;
@@ -7488,8 +7613,7 @@ static int nl80211_send_frame(void *priv, const u8 *data, size_t data_len,
 			      int encrypt)
 {
 	struct i802_bss *bss = priv;
-	struct wpa_driver_nl80211_data *drv = bss->drv;
-	return wpa_driver_nl80211_send_frame(drv, data, data_len, encrypt, 0);
+	return wpa_driver_nl80211_send_frame(bss, data, data_len, encrypt, 0);
 }
 
 
-- 
Jouni Malinen                                            PGP id EFC895FA


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