Add optional steering_ssid allow-list to scope DAWN per SSID

CONFIGURE.md

@@ -288,3 +288,16 @@ grep 'CONFIG-H:' `find . -type f -name "*.[ch]"`|sed 's/^.*CONFIG-.: *\(.*\)$/|\
 |Parameter|Purpose|Notes [Default is bracketed]|
 |---------|-------|-----|
 |hostapd_dir|Path to hostapd runtime information|[/var/run/hostapd]|
+|steering_ssid|SSID that DAWN is allowed to manage (repeatable; empty = all)|[]|
+
+By default DAWN manages every BSS it discovers under `hostapd_dir`. To limit
+DAWN to a subset of your networks, add one `list steering_ssid '<SSID>'` entry
+per SSID you want managed. Any BSS whose SSID is not listed is left entirely
+alone: DAWN never subscribes to it, so it neither steers/kicks its clients nor
+shares their measurements with peer APs. When no `steering_ssid` is configured
+the list is empty and the historic "manage everything" behaviour is preserved.
+
+    config hostapd
+        option hostapd_dir '/var/run/hostapd'
+        list steering_ssid 'MyMainNetwork'
+        list steering_ssid 'MyRoamingNetwork'

dawn-config

@@ -16,6 +16,10 @@ config network
 
 config hostapd
 	option hostapd_dir '/var/run/hostapd'
+	# Optional: restrict DAWN to specific SSIDs. Repeat for each managed
+	# SSID. If no steering_ssid is listed, DAWN manages every BSS (default).
+	#list steering_ssid 'MyMainNetwork'
+	#list steering_ssid 'MyRoamingNetwork'
 
 config times
 	option con_timeout '60'

src/include/dawn_uci.h

@@ -46,6 +46,18 @@ struct network_config_s uci_get_dawn_network();
  */
 bool uci_get_dawn_hostapd_dir();
 
+/**
+ * Load the optional allow-list of SSIDs that DAWN may manage from the config
+ * file. When no 'steering_ssid' entries are present DAWN manages every BSS.
+ */
+void uci_get_dawn_steering_ssids();
+
+/**
+ * Test whether a given SSID is in the configured steering allow-list.
+ * @return true if the SSID may be managed (always true when the list is empty).
+ */
+bool dawn_ssid_is_managed(const char *ssid);
+
 int uci_set_network(char* uci_cmd);
 
 /**

src/main.c

@@ -114,6 +114,7 @@ int main(int argc, char **argv) {
     timeout_config = time_config; // TODO: Refactor...
 
     uci_get_dawn_hostapd_dir();
+    uci_get_dawn_steering_ssids();
 
     init_mutex();
 

src/utils/dawn_uci.c

@@ -468,6 +468,65 @@ bool uci_get_dawn_hostapd_dir() {
     return false;
 }
 
+// Optional allow-list of SSIDs that DAWN is permitted to manage.  When the
+// list is empty DAWN keeps its default behaviour of managing every BSS it
+// finds, so the feature is opt-in and backwards compatible.
+struct steering_ssid_s {
+    char ssid[SSID_MAX_LEN + 1];
+    struct steering_ssid_s *next;
+};
+
+static struct steering_ssid_s *steering_ssid_list = NULL;
+
+void uci_get_dawn_steering_ssids() {
+    dawnlog_debug_func("Entering...");
+
+    // Drop any previously loaded list (e.g. on config reload)
+    while (steering_ssid_list) {
+        struct steering_ssid_s *tmp = steering_ssid_list;
+        steering_ssid_list = steering_ssid_list->next;
+        dawn_free(tmp);
+    }
+
+    struct uci_element *e;
+    uci_foreach_element(&uci_pkg->sections, e)
+    {
+        struct uci_section *s = uci_to_section(e);
+
+        if (strcmp(s->type, "hostapd") == 0) {
+            // CONFIG-H: steering_ssid|SSID that DAWN is allowed to manage (repeatable; empty = all)|[]
+            struct uci_option *o = uci_lookup_option(uci_ctx, s, "steering_ssid");
+            if (o && o->type == UCI_TYPE_LIST) {
+                struct uci_element *le;
+                uci_foreach_element(&o->v.list, le)
+                {
+                    struct steering_ssid_s *entry = dawn_calloc(1, sizeof(struct steering_ssid_s));
+                    if (!entry)
+                        continue;
+                    strncpy(entry->ssid, le->name, SSID_MAX_LEN);
+                    entry->ssid[SSID_MAX_LEN] = '\0';
+                    entry->next = steering_ssid_list;
+                    steering_ssid_list = entry;
+                }
+            }
+            return;
+        }
+    }
+}
+
+bool dawn_ssid_is_managed(const char *ssid) {
+    // Empty allow-list => manage everything (default DAWN behaviour)
+    if (steering_ssid_list == NULL)
+        return true;
+
+    for (struct steering_ssid_s *e = steering_ssid_list; e; e = e->next) {
+        if (strncmp(e->ssid, ssid, SSID_MAX_LEN) == 0)
+            return true;
+    }
+
+    return false;
+}
+
 int uci_reset()
 {
     dawnlog_debug_func("Entering...");

src/utils/ubus.c

@@ -1818,6 +1818,20 @@ void subscribe_to_new_interfaces(const char *hostapd_sock_path) {
                     break;
                 }
             }
+            // Honour the optional steering_ssid allow-list: if we can read the
+            // BSS's SSID and it is not permitted, leave the interface entirely
+            // unmanaged (no subscription, no probes, not shared with peers).
+            // Fail open: if the SSID cannot be determined, manage it as before.
+            if (do_subscribe) {
+                char iface_ssid[SSID_MAX_LEN + 1] = {0};
+                get_ssid(entry->d_name, iface_ssid, SSID_MAX_LEN);
+                if (iface_ssid[0] != '\0' && !dawn_ssid_is_managed(iface_ssid)) {
+                    dawnlog_info("[SUBSCRIBING] Skipping %s: SSID '%s' not in steering_ssid list\n",
+                                 entry->d_name, iface_ssid);
+                    do_subscribe = false;
+                }
+            }
+
             if (do_subscribe) {
                 subscriber_to_interface(entry->d_name);
             }