[PATCH usteer v2] New aggressive roaming to support Intel Wifi Cards

Nils Hendrik Rottgardt n.rottgardt at gmail.com
Sun Oct 20 11:47:32 PDT 2024


Intel Wifi Cards (and based on OpenWRT forum posts also some other devices) does not understand the actual transition request frame because of missing disassociation_timer combined with disassociation_imminent = true. So they and other devices send a BSS-TM-RESP with status=1 (error).
This patch will add some new options and also fix the inconsistent disassocition_timer/_imminent call to bss_transition_request.

- Added aggressive roaming (disaccociation_timer)
- Added 3 new options in config to enable aggressive roaming for all or specific MAC addresses
- Calling bss_transition_request with disassociation_imminent = false as new default
- Using abridged flag to put priority on neighbor provided

Signed-off-by: Nils Hendrik Rottgardt <n.rottgardt at gmail.com>
---
 band_steering.c                        | 10 ++++--
 local_node.c                           | 21 ++++++++++--
 main.c                                 |  2 ++
 openwrt/usteer/files/etc/config/usteer |  9 ++++++
 openwrt/usteer/files/etc/init.d/usteer |  4 ++-
 policy.c                               | 17 ++++++++--
 sta.c                                  | 24 ++++++++++++++
 ubus.c                                 | 45 +++++++++++++++++++-------
 usteer.h                               | 30 +++++++++++++----
 9 files changed, 134 insertions(+), 28 deletions(-)

diff --git a/band_steering.c b/band_steering.c
index 7fce1df..d7ff8cf 100644
--- a/band_steering.c
+++ b/band_steering.c
@@ -81,6 +81,8 @@ void usteer_band_steering_perform_steer(struct usteer_local_node *ln)
 	ln->band_steering_interval = 0;
 
 	list_for_each_entry(si, &ln->node.sta_info, node_list) {
+		/* TODO: Steer only if Client supports > 4000 Frequency */
+
 		/* Check if client is eligable to be steerd */
 		if (!usteer_policy_can_perform_roam(si))
 			continue;
@@ -91,8 +93,12 @@ void usteer_band_steering_perform_steer(struct usteer_local_node *ln)
 			continue;
 		}
 
-		if (si->bss_transition)
-			usteer_ubus_band_steering_request(si);
+		if (si->bss_transition) {
+			if (si->sta->aggressive)
+				usteer_ubus_band_steering_request(si, 0, true, config.aggressive_disassoc_timer, true, config.aggressive_disassoc_timer);
+			else
+				usteer_ubus_band_steering_request(si, 0, false, 0, true, 100);
+		}
 
 		si->band_steering.below_snr = false;
 	}
diff --git a/local_node.c b/local_node.c
index e74d945..6aa7008 100644
--- a/local_node.c
+++ b/local_node.c
@@ -748,7 +748,7 @@ usteer_local_node_process_bss_tm_queries(struct uloop_timeout *timeout)
 		if (!si)
 			continue;
 
-		usteer_ubus_bss_transition_request(si, query->dialog_token, false, false, validity_period, NULL);
+		usteer_ubus_bss_transition_request(si, query->dialog_token, config.aggressive_all, validity_period, true, validity_period, NULL);
 	}
 
 	/* Free pending queries we can not handle */
@@ -977,8 +977,23 @@ void config_get_ssid_list(struct blob_buf *buf)
 		blobmsg_add_blob(buf, config.ssid_list);
 }
 
-void
-usteer_local_nodes_init(struct ubus_context *ctx)
+void config_set_aggressive_mac_list(struct blob_attr *data)
+{
+	free(config.aggressive_mac_list);
+
+	if (data && blobmsg_len(data))
+		config.aggressive_mac_list = blob_memdup(data);
+	else
+		config.aggressive_mac_list = NULL;
+}
+
+void config_get_aggressive_mac_list(struct blob_buf *buf)
+{
+	if (config.aggressive_mac_list)
+		blobmsg_add_blob(buf, config.aggressive_mac_list);
+}
+
+void usteer_local_nodes_init(struct ubus_context *ctx)
 {
 	usteer_register_events(ctx);
 	ubus_lookup(ctx, "hostapd.*", node_list_cb, NULL);
diff --git a/main.c b/main.c
index 99aa6ad..b07b624 100644
--- a/main.c
+++ b/main.c
@@ -96,6 +96,8 @@ void usteer_init_defaults(void)
 	config.remote_update_interval = 1000;
 	config.initial_connect_delay = 0;
 	config.remote_node_timeout = 10;
+	config.aggressive_all = false;
+	config.aggressive_disassoc_timer = 100;
 
 	config.steer_reject_timeout = 60000;
 
diff --git a/openwrt/usteer/files/etc/config/usteer b/openwrt/usteer/files/etc/config/usteer
index f53c338..2fe47f3 100644
--- a/openwrt/usteer/files/etc/config/usteer
+++ b/openwrt/usteer/files/etc/config/usteer
@@ -71,6 +71,15 @@ config usteer
 	# Timeout (ms) for which a client will not be steered after rejecting a BSS-transition-request
 	#option steer_reject_timeout 60000
 
+	# Use aggressvice roaming to push clients to another AP
+	#option aggressive_all 0
+
+	# List of MACs to enable aggressive roaming on. If not set all macs will handled aggressive
+	#list aggressive_mac_list ''
+
+	# Disassociation imminent tuner - in aggresive mode the time a client has to roam away before disconnected hardly
+	#option aggressive_disassoc_timer 100
+
 	# Timeout (in ms) after which a association following a disassociation is not seen
 	# as a roam
 	#option roam_process_timeout 5000
diff --git a/openwrt/usteer/files/etc/init.d/usteer b/openwrt/usteer/files/etc/init.d/usteer
index 07fd99e..fdc8211 100755
--- a/openwrt/usteer/files/etc/init.d/usteer
+++ b/openwrt/usteer/files/etc/init.d/usteer
@@ -69,8 +69,10 @@ uci_usteer() {
 	uci_option_to_json_bool "$cfg" local_mode
 	uci_option_to_json_bool "$cfg" load_kick_enabled
 	uci_option_to_json_bool "$cfg" assoc_steering
+	uci_option_to_json_bool "$cfg" aggressive_all
 	uci_option_to_json_string "$cfg" node_up_script
 	uci_option_to_json_string_array "$cfg" ssid_list
+	uci_option_to_json_string_array "$cfg" aggressive_mac_list
 	uci_option_to_json_string_array "$cfg" event_log_types
 
 	for opt in \
@@ -84,7 +86,7 @@ uci_usteer() {
 		initial_connect_delay steer_reject_timeout roam_process_timeout\
 		roam_kick_delay roam_scan_tries roam_scan_timeout \
 		roam_scan_snr roam_scan_interval \
-		roam_trigger_snr roam_trigger_interval \
+		roam_trigger_snr roam_trigger_interval aggressive_disassoc_timer\
 		band_steering_interval band_steering_min_snr link_measurement_interval \
 		load_kick_threshold load_kick_delay load_kick_min_clients \
 		load_kick_reason_code
diff --git a/policy.c b/policy.c
index 8c5d244..e66f2d4 100644
--- a/policy.c
+++ b/policy.c
@@ -370,8 +370,15 @@ usteer_roam_trigger_sm(struct usteer_local_node *ln, struct sta_info *si)
 			break;
 		}
 
-		usteer_ubus_bss_transition_request(si, 1, false, false, 100, candidate->node);
-		si->kick_time = current_time + config.roam_kick_delay;
+		if (si->sta->aggressive) {
+			// TODO: Disaccociation Timer noch konfigurierbar machen
+			usteer_ubus_bss_transition_request(si, 1, true, config.aggressive_disassoc_timer, true, config.aggressive_disassoc_timer, candidate->node);
+			si->roam_disassoc_time = current_time + (100 * 100);
+		} else {
+			usteer_ubus_bss_transition_request(si, 1, false, 0, true, 100, candidate->node);
+			si->kick_time = current_time + config.roam_kick_delay;
+		}
+
 		usteer_roam_set_state(si, ROAM_TRIGGER_IDLE, &ev);
 		break;
 	}
@@ -400,7 +407,11 @@ bool usteer_policy_can_perform_roam(struct sta_info *si)
 	/* Skip if connection is established shorter than the trigger-interval */
 	if (current_time - si->connected_since < config.roam_trigger_interval)
 		return false;
-	
+
+	/* Skip on aggressive roaming in progress - wait 10s after disassociation event*/
+	if (current_time - si->roam_disassoc_time < 10000)
+		return false;
+
 	return true;
 }
 
diff --git a/sta.c b/sta.c
index ed7e40e..6cce149 100644
--- a/sta.c
+++ b/sta.c
@@ -76,6 +76,28 @@ usteer_sta_info_timeout(struct usteer_timeout_queue *q, struct usteer_timeout *t
 	usteer_sta_info_del(si);
 }
 
+static void
+usteer_sta_update_aggressive(struct sta *sta)
+{
+	struct blob_attr *cur;
+	int rem;
+	char sta_mac[18];
+	sprintf(sta_mac, MAC_ADDR_FMT, MAC_ADDR_DATA(sta->addr));
+
+	if (config.aggressive_all)
+		sta->aggressive = true;
+	else {
+		sta->aggressive = false;
+		blobmsg_for_each_attr(cur, config.aggressive_mac_list, rem) {
+			if (strcmp(blobmsg_get_string(cur), sta_mac) != 0)
+				continue;
+
+			sta->aggressive = true;
+			break;
+		}
+	}
+}
+
 struct sta_info *
 usteer_sta_info_get(struct sta *sta, struct usteer_node *node, bool *create)
 {
@@ -105,6 +127,8 @@ usteer_sta_info_get(struct sta *sta, struct usteer_node *node, bool *create)
 	si->created = current_time;
 	*create = true;
 
+	usteer_sta_update_aggressive(sta);
+
 	/* Node is by default not connected. */
 	usteer_sta_disconnected(si);
 
diff --git a/ubus.c b/ubus.c
index 40daf74..fd6e224 100644
--- a/ubus.c
+++ b/ubus.c
@@ -162,6 +162,9 @@ struct cfg_item {
 	_cfg(U32, remote_update_interval), \
 	_cfg(U32, remote_node_timeout), \
 	_cfg(BOOL, assoc_steering), \
+	_cfg(BOOL, aggressive_all), \
+	_cfg(ARRAY_CB, aggressive_mac_list), \
+	_cfg(U32, aggressive_disassoc_timer), \
 	_cfg(I32, min_connect_snr), \
 	_cfg(I32, min_snr), \
 	_cfg(U32, min_snr_kick_delay), \
@@ -668,11 +671,12 @@ usteer_ubus_disassoc_add_neighbors(struct sta_info *si)
 }
 
 int usteer_ubus_bss_transition_request(struct sta_info *si,
-				       uint8_t dialog_token,
-				       bool disassoc_imminent,
-				       bool abridged,
-				       uint8_t validity_period,
-				       struct usteer_node *target_node)
+                                       uint8_t dialog_token,
+                                       bool disassoc_imminent,
+                                       uint8_t disassoc_timer,
+                                       bool abridged,
+                                       uint8_t validity_period,
+                                       struct usteer_node *target_node)
 {
 	struct usteer_local_node *ln = container_of(si->node, struct usteer_local_node, node);
 
@@ -680,17 +684,28 @@ int usteer_ubus_bss_transition_request(struct sta_info *si,
 	blobmsg_printf(&b, "addr", MAC_ADDR_FMT, MAC_ADDR_DATA(si->sta->addr));
 	blobmsg_add_u32(&b, "dialog_token", dialog_token);
 	blobmsg_add_u8(&b, "disassociation_imminent", disassoc_imminent);
+	if (disassoc_imminent) {
+		blobmsg_add_u32(&b, "disassociation_timer", disassoc_timer);
+	}
 	blobmsg_add_u8(&b, "abridged", abridged);
 	blobmsg_add_u32(&b, "validity_period", validity_period);
 	if (!target_node) {
+		// Add all known neighbors if no specific target set
+		MSG(DEBUG, "ROAMING requested for sta=" MAC_ADDR_FMT " without target\n", MAC_ADDR_DATA(si->sta->addr));
 		usteer_ubus_disassoc_add_neighbors(si);
 	} else {
+		MSG(DEBUG, "ROAMING requested for sta=" MAC_ADDR_FMT " to %s with disassociation timer %i\n", MAC_ADDR_DATA(si->sta->addr), usteer_node_name(target_node), disassoc_timer);
 		usteer_ubus_disassoc_add_neighbor(si, target_node);
 	}
 	return ubus_invoke(ubus_ctx, ln->obj_id, "bss_transition_request", b.head, NULL, 0, 100);
 }
 
-int usteer_ubus_band_steering_request(struct sta_info *si)
+int usteer_ubus_band_steering_request(struct sta_info *si,
+                                      uint8_t dialog_token,
+                                      bool disassoc_imminent,
+                                      uint8_t disassoc_timer,
+                                      bool abridged,
+                                      uint8_t validity_period)
 {
 	struct usteer_local_node *ln = container_of(si->node, struct usteer_local_node, node);
 	struct usteer_node *node;
@@ -698,10 +713,13 @@ int usteer_ubus_band_steering_request(struct sta_info *si)
 
 	blob_buf_init(&b, 0);
 	blobmsg_printf(&b, "addr", MAC_ADDR_FMT, MAC_ADDR_DATA(si->sta->addr));
-	blobmsg_add_u32(&b, "dialog_token", 0);
-	blobmsg_add_u8(&b, "disassociation_imminent", false);
-	blobmsg_add_u8(&b, "abridged", false);
-	blobmsg_add_u32(&b, "validity_period", 100);
+	blobmsg_add_u32(&b, "dialog_token", dialog_token);
+	blobmsg_add_u8(&b, "disassociation_imminent", disassoc_imminent);
+	if (disassoc_imminent) {
+		blobmsg_add_u32(&b, "disassociation_timer", disassoc_timer);
+	}
+	blobmsg_add_u8(&b, "abridged", abridged);
+	blobmsg_add_u32(&b, "validity_period", validity_period);
 
 	c = blobmsg_open_array(&b, "neighbors");
 	for_each_local_node(node) {
@@ -711,8 +729,11 @@ int usteer_ubus_band_steering_request(struct sta_info *si)
 		usteer_add_nr_entry(si->node, node);
 	}
 	blobmsg_close_array(&b, c);
-
-	return ubus_invoke(ubus_ctx, ln->obj_id, "bss_transition_request", b.head, NULL, 0, 100);
+	if (sizeof(si->node) > 0) {
+		MSG(DEBUG, "BAND STEERING requested for sta=" MAC_ADDR_FMT " with disassociation timer %i\n", MAC_ADDR_DATA(si->sta->addr), disassoc_timer);
+		return ubus_invoke(ubus_ctx, ln->obj_id, "bss_transition_request", b.head, NULL, 0, 100);
+	} else
+		MSG(DEBUG, "BAND STEERING no targets found for sta=" MAC_ADDR_FMT "\n", MAC_ADDR_DATA(si->sta->addr));
 }
 
 int usteer_ubus_trigger_link_measurement(struct sta_info *si)
diff --git a/usteer.h b/usteer.h
index f692fb8..f771c37 100644
--- a/usteer.h
+++ b/usteer.h
@@ -170,6 +170,10 @@ struct usteer_config {
 	uint32_t remote_update_interval;
 	uint32_t remote_node_timeout;
 
+	bool aggressive_all;
+	struct blob_attr *aggressive_mac_list;
+	uint32_t aggressive_disassoc_timer;
+
 	int32_t min_snr;
 	uint32_t min_snr_kick_delay;
 	int32_t min_connect_snr;
@@ -190,7 +194,7 @@ struct usteer_config {
 	uint32_t roam_kick_delay;
 
 	uint32_t band_steering_interval;
-	int32_t band_steering_min_snr; 
+	int32_t band_steering_min_snr;
 
 	uint32_t link_measurement_interval;
 
@@ -255,6 +259,7 @@ struct sta_info {
 	uint8_t roam_tries;
 	uint64_t roam_event;
 	uint64_t roam_kick;
+	uint64_t roam_disassoc_time;
 	uint64_t roam_scan_start;
 	uint64_t roam_scan_timeout_start;
 
@@ -285,6 +290,8 @@ struct sta {
 	uint8_t seen_2ghz : 1;
 	uint8_t seen_5ghz : 1;
 
+	bool aggressive;
+
 	uint8_t addr[6];
 };
 
@@ -336,13 +343,19 @@ bool usteer_band_steering_is_target(struct usteer_local_node *ln, struct usteer_
 void usteer_ubus_init(struct ubus_context *ctx);
 void usteer_ubus_kick_client(struct sta_info *si);
 int usteer_ubus_trigger_client_scan(struct sta_info *si);
-int usteer_ubus_band_steering_request(struct sta_info *si);
+int usteer_ubus_band_steering_request(struct sta_info *si,
+                                      uint8_t dialog_token,
+                                      bool disassoc_imminent,
+                                      uint8_t disassoc_timer,
+                                      bool abridged,
+                                      uint8_t validity_period);
 int usteer_ubus_bss_transition_request(struct sta_info *si,
-				       uint8_t dialog_token,
-				       bool disassoc_imminent,
-				       bool abridged,
-				       uint8_t validity_period,
-				       struct usteer_node *target_node);
+                                       uint8_t dialog_token,
+                                       bool disassoc_imminent,
+                                       uint8_t disassoc_timer,
+                                       bool abridged,
+                                       uint8_t validity_period,
+                                       struct usteer_node *target_node);
 
 struct sta *usteer_sta_get(const uint8_t *addr, bool create);
 struct sta_info *usteer_sta_info_get(struct sta *sta, struct usteer_node *node, bool *create);
@@ -376,6 +389,9 @@ void config_get_node_up_script(struct blob_buf *buf);
 void config_set_ssid_list(struct blob_attr *data);
 void config_get_ssid_list(struct blob_buf *buf);
 
+void config_set_aggressive_mac_list(struct blob_attr *data);
+void config_get_aggressive_mac_list(struct blob_buf *buf);
+
 int usteer_interface_init(void);
 void usteer_interface_add(const char *name);
 void usteer_sta_node_cleanup(struct usteer_node *node);
-- 
2.39.5




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