daemon: allow to specify hostapd interfaces

Allow specification of hostapd interface names. This allows to set the
diagnostic vendor element only on a subset of VIFs, ptentially
conserving airtime in case multiple VIFs are operating on the same
radio.

Signed-off-by: David Bauer <mail@david-bauer.net>

openwrt/node-whisperer/files/node-whisperer.init

@@ -23,6 +23,13 @@ uci_nw() {
 	config_list_foreach "$cfg" "information" uci_nw_add_json_string
 	json_close_array
 	ubus call node_whisperer set_sources "$(json_dump)"
+
+	# Enabled interfaces
+	json_init
+	json_add_array interfaces
+	config_list_foreach "$cfg" "interface" uci_nw_add_json_string
+	json_close_array
+	ubus call node_whisperer set_interfaces "$(json_dump)"
 }
 
 load_config() {

openwrt/node-whisperer/files/node-whisperer.uci

@@ -10,3 +10,5 @@ config settings 'settings'
 	list information 'system_load'
 	list information 'firmware_version'
 	list information 'batman_adv'
+	list interface 'client0'
+	list interface 'client1'

src/daemon.c

@@ -130,7 +130,7 @@ static void nw_daemon_collect_information(struct uloop_timeout *timeout) {
 
 	/* Update nodes */
 	log_debug("Update %s", buf_hex);
-	nw_interface_update(instance->ubus_ctx, (char *)buf_hex);
+	nw_interface_update(&instance->ubus_ctx, (char *)buf_hex);
 
 	instance->statistics.update_count++;
 
@@ -141,18 +141,19 @@ static void nw_daemon_collect_information(struct uloop_timeout *timeout) {
 
 static int start_daemon() {
 	struct nw instance = {};
+
+	INIT_LIST_HEAD(&instance.enabled_interfaces);
 
 	uloop_init();
 
-	instance.ubus_ctx = ubus_connect(NULL);
-	if (!instance.ubus_ctx) {
-		fprintf(stderr, "Failed to connect to ubus");
+	if (ubus_connect_ctx(&instance.ubus_ctx, NULL)) {
+		log_error("Failed to connect to ubus");
 		return -1;
 	}
 
 	/* Init ubus */
-	ubus_add_uloop(instance.ubus_ctx);
-	nw_ubus_init(instance.ubus_ctx);
+	ubus_add_uloop(&instance.ubus_ctx);
+	nw_ubus_init(&instance.ubus_ctx);
 
 	/* Add Information gathering timer */
 	instance.update_timeout.cb = nw_daemon_collect_information;

src/daemon.h

@@ -2,9 +2,15 @@
 
 #include "node-whisperer.h"
 
+struct nw_enabled_interface {
+	struct list_head list;
+	char *name;
+};
+
 struct nw {
-	struct ubus_context *ubus_ctx;
+	struct ubus_context ubus_ctx;
 	struct uloop_timeout update_timeout;
+	struct list_head enabled_interfaces;
 
 	struct {
 		uint8_t *buf;

src/interface.c

@@ -1,4 +1,7 @@
 #include "node-whisperer.h"
+#include "daemon.h"
+
+#define UBUS_HOSTAPD_PREFIX "hostapd."
 
 static LIST_HEAD(nw_interfaces);
 static struct blob_buf b;
@@ -23,15 +26,45 @@ static void nw_interface_handle_remove(struct ubus_context *ctx,
 	nw_interface_remove(ctx, iface);
 }
 
+static int nw_interface_enabled(struct nw *instance, const char *name)
+{
+	struct nw_enabled_interface *iface;
+	const char *hostapd_name;
+
+	/* Always enabled when list of enabled interfaces empty */
+	if (list_empty(&instance->enabled_interfaces)) {
+		return 1;
+	}
+
+	if (strlen(name) <= strlen(UBUS_HOSTAPD_PREFIX)) {
+		return 0;
+	}
+
+	hostapd_name = (char *)name + strlen(UBUS_HOSTAPD_PREFIX);
+
+	list_for_each_entry(iface, &instance->enabled_interfaces, list) {
+		if (!strcmp(hostapd_name, iface->name)) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 int nw_interface_update(struct ubus_context *ctx, char *vendor_elements)
 {
+	struct nw *instance = container_of(ctx, struct nw, ubus_ctx);
 	struct nw_interface *iface;
 	int ret;
 
 	list_for_each_entry(iface, &nw_interfaces, list) {
 		blob_buf_init(&b, 0);
 		blobmsg_add_string(&b, "vendor_elements", vendor_elements);
 
+		if (!nw_interface_enabled(instance, iface->ubus.name)) {
+			continue;
+		}
+
 		log_debug("Sending vendor elements to id=%d name=%s", iface->ubus.id, iface->ubus.name);
 		ret = ubus_invoke(ctx, iface->ubus.id, "set_vendor_elements", b.head, NULL, NULL, 1000);
 		if (ret) {
@@ -40,6 +73,7 @@ int nw_interface_update(struct ubus_context *ctx, char *vendor_elements)
 			/* Delete element */
 			blob_buf_init(&b, 0);
 			blobmsg_add_string(&b, "vendor_elements", "");
+
 			ret = ubus_invoke(ctx, iface->ubus.id, "set_vendor_elements", b.head, NULL, NULL, 1000);
 			if (ret) {
 				log_error("Failed to reset vendor elements for id=%d name=%s code=%d", iface->ubus.id, iface->ubus.name, ret);

src/ubus.c

@@ -1,10 +1,73 @@
+#include <string.h>
+
 #include "node-whisperer.h"
 #include "daemon.h"
 
 extern struct nw_information_source information_sources[];
 
 static struct blob_buf b;
 
+static struct blobmsg_policy set_interfaces_policy[] = {
+	{ .name = "interfaces", .type = BLOBMSG_TYPE_ARRAY, },
+};
+
+static int nw_ubus_set_interfaces(struct ubus_context *ctx, struct ubus_object *obj,
+				  struct ubus_request_data *req, const char *method,
+				  struct blob_attr *msg)
+{
+	struct nw *nw = container_of(ctx, struct nw, ubus_ctx);
+	struct nw_enabled_interface *iface;
+	const char *ifname;
+	struct blob_attr *cur;
+	struct blob_attr *tb = NULL;
+	size_t rem;
+
+	/* Parse message */
+	blobmsg_parse(set_interfaces_policy, 1, &tb, blob_data(msg), blob_len(msg));
+	if (!tb)
+		return UBUS_STATUS_INVALID_ARGUMENT;
+
+	log_debug("Setting new interface list\n");
+
+	/* Clear list */
+	while (!list_empty(&nw->enabled_interfaces)) {
+		log_debug("Clearing interface list\n");
+		iface = list_first_entry(&nw->enabled_interfaces, struct nw_enabled_interface, list);
+		list_del(&iface->list);
+		free(iface->name);
+		free(iface);
+	}
+
+	log_debug("Setting interface list\n");
+
+	/* Add new interfaces */
+	blobmsg_for_each_attr(cur, tb, rem) {
+		if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
+			return UBUS_STATUS_INVALID_ARGUMENT;
+
+		ifname = blobmsg_get_string(cur);
+		if (!ifname)
+			return UBUS_STATUS_INVALID_ARGUMENT;
+
+		log_debug("Add interface %s\n", ifname);
+
+		iface = calloc(1, sizeof(*iface));
+		if (!iface)
+			return UBUS_STATUS_UNKNOWN_ERROR;
+
+		iface->name = strdup(ifname);
+		if (!iface->name) {
+			free(iface);
+			return UBUS_STATUS_UNKNOWN_ERROR;
+		}
+
+		list_add_tail(&iface->list, &nw->enabled_interfaces);
+	}
+
+	return 0;
+}
+
+
 static struct blobmsg_policy source_toggle_arg[] = {
 	{ .name = "information_sources", .type = BLOBMSG_TYPE_ARRAY, },
 };
@@ -109,6 +172,7 @@ static int nw_ubus_statistics(struct ubus_context *ctx, struct ubus_object *obj,
 }
 
 static const struct ubus_method nw_methods[] = {
+	UBUS_METHOD("set_interfaces", nw_ubus_set_interfaces, set_interfaces_policy),
 	UBUS_METHOD("set_sources", nw_ubus_enable_source, source_toggle_arg),
 	UBUS_METHOD_NOARG("get_sources", nw_ubus_get_sources),
 	UBUS_METHOD_NOARG("statistics", nw_ubus_statistics),