From: Michael Tremer <michael.tremer@ipfire.org>
Date: Fri, 29 May 2026 08:41:30 +0000 (+0000)
Subject: netlink: Add a helper function to enumerate all wireless interfaces
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=705be8a98afaa7766629c8486606c3fdafde7cce;p=telemetry.git

netlink: Add a helper function to enumerate all wireless interfaces

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/daemon/netlink.c b/src/daemon/netlink.c
index 2ae14b7..e784743 100644
--- a/src/daemon/netlink.c
+++ b/src/daemon/netlink.c
@@ -21,6 +21,7 @@
 #ifdef HAVE_LIBNL3
 
 #include <errno.h>
+#include <linux/nl80211.h>
 #include <netlink/socket.h>
 #include <stdlib.h>
 
@@ -332,6 +333,60 @@ static int td_netlink_get_nl80211_id(td_netlink* self) {
 
 	return self->nl80211.id;
 }
+
+int td_netlink_enumerate_wireless_interfaces(td_netlink* self,
+		td_netlink_enumerate_wireless_interfaces_callback callback, void* data) {
+	struct nl_sock* sock = NULL;
+	struct nl_msg* msg = NULL;
+	int nl80211_id;
+	int r;
+
+	// Fetch the nl80211 socket
+	sock = td_netlink_get_nl80211_socket(self);
+	if (!sock)
+		return -errno;
+
+	// Fetch the ID
+	nl80211_id = td_netlink_get_nl80211_id(self);
+	if (!nl80211_id)
+		return -errno;
+
+	// Allocate a new message
+	msg = nlmsg_alloc();
+	if (!msg) {
+		ERROR(self->ctx, "Failed to allocate a netlink message: %m\n");
+		r = -errno;
+		goto ERROR;
+	}
+
+	// Request a dump of all wireless interfaces
+	genlmsg_put(msg, 0, 0, nl80211_id, 0, NLM_F_DUMP, NL80211_CMD_GET_INTERFACE, 0);
+
+	// Set the callback and send
+	nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM,
+		NULL, data);
+
+	// Send the message
+	r = nl_send_auto(sock, msg);
+	if (r < 0) {
+		ERROR(self->ctx, "Failed to send nl80211 request: %s\n", nl_geterror(r));
+		goto ERROR;
+	}
+
+	// Receive the response
+	r = nl_recvmsgs_default(sock);
+	if (r < 0) {
+		ERROR(self->ctx, "Failed to receive nl80211 response: %s\n", nl_geterror(r));
+		goto ERROR;
+	}
+
+ERROR:
+	if (msg)
+		nlmsg_free(msg);
+
+	return r;
+}
+
 # endif /* HAVE_LIBNL3_GENL */
 
 #endif /* HAVE_LIBNL3 */
diff --git a/src/daemon/netlink.h b/src/daemon/netlink.h
index 39b895d..85715fe 100644
--- a/src/daemon/netlink.h
+++ b/src/daemon/netlink.h
@@ -46,6 +46,16 @@ int td_netlink_get_default_gateway(td_netlink* self,
 
 #endif /* HAVE_LIBNL3_ROUTE */
 
+#ifdef HAVE_LIBNL3_GENL
+
+typedef int (*td_netlink_enumerate_wireless_interfaces_callback)
+	(td_ctx* ctx, const char* name, struct rtnl_link* link, void* data);
+
+int td_netlink_enumerate_wireless_interfaces(td_netlink* self,
+	td_netlink_enumerate_wireless_interfaces_callback callback, void* data);
+
+#endif /* HAVE_LIBNL3_GENL */
+
 #endif /* HAVE_LIBNL3 */
 
 #endif /* TELEMETRY_NETLINK_H */