hostapd: add support for automatically setting RADIUS own-ip dynamically

Some servers use the NAS-IP-Address attribute as a destination address

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/network/services/hostapd/files/hostapd.sh

@@ -687,7 +687,7 @@ hostapd_set_bss_options() {
 			json_get_vars \
 				auth_server auth_secret auth_port \
 				dae_client dae_secret dae_port \
-				ownip radius_client_addr \
+				dynamic_ownip ownip radius_client_addr \
 				eap_reauth_period request_cui \
 				erp_domain mobility_domain \
 				fils_realm fils_dhcp
@@ -695,6 +695,8 @@ hostapd_set_bss_options() {
 			# radius can provide VLAN ID for clients
 			vlan_possible=1
 
+			set_default dynamic_ownip 1
+
 			# legacy compatibility
 			[ -n "$auth_server" ] || json_get_var auth_server server
 			[ -n "$auth_port" ] || json_get_var auth_port port
@@ -743,7 +745,12 @@ hostapd_set_bss_options() {
 			}
 			json_for_each_item append_radius_auth_req_attr radius_auth_req_attr
 
-			[ -n "$ownip" ] && append bss_conf "own_ip_addr=$ownip" "$N"
+			if [ -n "$ownip" ]; then
+				append bss_conf "own_ip_addr=$ownip" "$N"
+			elif [ "$dynamic_ownip" -gt 0 ]; then
+				append bss_conf "dynamic_own_ip_addr=$dynamic_ownip" "$N"
+			fi
+
 			[ -n "$radius_client_addr" ] && append bss_conf "radius_client_addr=$radius_client_addr" "$N"
 			append bss_conf "eapol_key_index_workaround=1" "$N"
 			append bss_conf "ieee8021x=1" "$N"

package/network/services/hostapd/patches/760-dynamic_own_ip.patch

@@ -0,0 +1,109 @@
+--- a/src/ap/ap_config.h
++++ b/src/ap/ap_config.h
+@@ -311,6 +311,7 @@ struct hostapd_bss_config {
+ 	unsigned int eap_sim_db_timeout;
+ 	int eap_server_erp; /* Whether ERP is enabled on internal EAP server */
+ 	struct hostapd_ip_addr own_ip_addr;
++	int dynamic_own_ip_addr;
+ 	char *nas_identifier;
+ 	struct hostapd_radius_servers *radius;
+ 	int acct_interim_interval;
+--- a/src/radius/radius_client.c
++++ b/src/radius/radius_client.c
+@@ -163,6 +163,8 @@ struct radius_client_data {
+ 	 */
+ 	void *ctx;
+ 
++	struct hostapd_ip_addr local_ip;
++
+ 	/**
+ 	 * conf - RADIUS client configuration (list of RADIUS servers to use)
+ 	 */
+@@ -720,6 +722,30 @@ static void radius_client_list_add(struc
+ 
+ 
+ /**
++ * radius_client_send - Get local address for the RADIUS auth socket
++ * @radius: RADIUS client context from radius_client_init()
++ * @addr: pointer to store the address
++ *
++ * This function returns the local address for the connection to the RADIUS
++ * auth server. It also opens the socket if it's not available yet.
++ */
++int radius_client_get_local_addr(struct radius_client_data *radius,
++				 struct hostapd_ip_addr *addr)
++{
++	struct hostapd_radius_servers *conf = radius->conf;
++
++	if (conf->auth_server && radius->auth_sock < 0)
++		radius_client_init_auth(radius);
++
++	if (radius->auth_sock < 0)
++		return -1;
++
++	memcpy(addr, &radius->local_ip, sizeof(*addr));
++
++	return 0;
++}
++
++/**
+  * radius_client_send - Send a RADIUS request
+  * @radius: RADIUS client context from radius_client_init()
+  * @msg: RADIUS message to be sent
+@@ -1238,6 +1264,10 @@ radius_change_server(struct radius_clien
+ 			wpa_printf(MSG_DEBUG, "RADIUS local address: %s:%u",
+ 				   inet_ntoa(claddr.sin_addr),
+ 				   ntohs(claddr.sin_port));
++			if (auth) {
++				radius->local_ip.af = AF_INET;
++				radius->local_ip.u.v4 = claddr.sin_addr;
++			}
+ 		}
+ 		break;
+ #ifdef CONFIG_IPV6
+@@ -1249,6 +1279,10 @@ radius_change_server(struct radius_clien
+ 				   inet_ntop(AF_INET6, &claddr6.sin6_addr,
+ 					     abuf, sizeof(abuf)),
+ 				   ntohs(claddr6.sin6_port));
++			if (auth) {
++				radius->local_ip.af = AF_INET6;
++				radius->local_ip.u.v6 = claddr6.sin6_addr;
++			}
+ 		}
+ 		break;
+ 	}
+--- a/src/radius/radius_client.h
++++ b/src/radius/radius_client.h
+@@ -249,6 +249,8 @@ int radius_client_register(struct radius
+ void radius_client_set_interim_error_cb(struct radius_client_data *radius,
+ 					void (*cb)(const u8 *addr, void *ctx),
+ 					void *ctx);
++int radius_client_get_local_addr(struct radius_client_data *radius,
++				 struct hostapd_ip_addr * addr);
+ int radius_client_send(struct radius_client_data *radius,
+ 		       struct radius_msg *msg,
+ 		       RadiusType msg_type, const u8 *addr);
+--- a/src/ap/ieee802_1x.c
++++ b/src/ap/ieee802_1x.c
+@@ -535,6 +535,10 @@ int add_common_radius_attr(struct hostap
+ 	struct hostapd_radius_attr *attr;
+ 	int len;
+ 
++	if (hapd->conf->dynamic_own_ip_addr)
++		radius_client_get_local_addr(hapd->radius,
++					     &hapd->conf->own_ip_addr);
++
+ 	if (!hostapd_config_get_radius_attr(req_attr,
+ 					    RADIUS_ATTR_NAS_IP_ADDRESS) &&
+ 	    hapd->conf->own_ip_addr.af == AF_INET &&
+--- a/hostapd/config_file.c
++++ b/hostapd/config_file.c
+@@ -2681,6 +2681,8 @@ static int hostapd_config_fill(struct ho
+ 	} else if (os_strcmp(buf, "iapp_interface") == 0) {
+ 		wpa_printf(MSG_INFO, "DEPRECATED: iapp_interface not used");
+ #endif /* CONFIG_IAPP */
++	} else if (os_strcmp(buf, "dynamic_own_ip_addr") == 0) {
++		bss->dynamic_own_ip_addr = atoi(pos);
+ 	} else if (os_strcmp(buf, "own_ip_addr") == 0) {
+ 		if (hostapd_parse_ip_addr(pos, &bss->own_ip_addr)) {
+ 			wpa_printf(MSG_ERROR,