From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 16 Mar 2023 11:35:50 +0100
Subject: [PATCH] hostapd: add experimental radius server

This can be used to run a standalone EAP server that can be used from
other APs. It uses json as user database format and can automatically
handle reload.

--- a/hostapd/Makefile
+++ b/hostapd/Makefile
@@ -63,6 +63,10 @@ endif
 OBJS += main.o
 OBJS += config_file.o
 
+ifdef CONFIG_RADIUS_SERVER
+OBJS += radius.o
+endif
+
 OBJS += ../src/ap/hostapd.o
 OBJS += ../src/ap/wpa_auth_glue.o
 OBJS += ../src/ap/drv_callbacks.o
--- a/hostapd/main.c
+++ b/hostapd/main.c
@@ -40,6 +40,7 @@ struct hapd_global {
 
 static struct hapd_global global;
 
+extern int radius_main(int argc, char **argv);
 
 #ifndef CONFIG_NO_HOSTAPD_LOGGER
 static void hostapd_logger_cb(void *ctx, const u8 *addr, unsigned int module,
@@ -793,6 +794,11 @@ int main(int argc, char *argv[])
 	if (os_program_init())
 		return -1;
 
+#ifdef RADIUS_SERVER
+	if (strstr(argv[0], "radius"))
+		return radius_main(argc, argv);
+#endif
+
 	os_memset(&interfaces, 0, sizeof(interfaces));
 	interfaces.reload_config = hostapd_reload_config;
 	interfaces.config_read_cb = hostapd_config_read;
--- a/src/radius/radius_server.c
+++ b/src/radius/radius_server.c
@@ -63,6 +63,12 @@ struct radius_server_counters {
 	u32 unknown_acct_types;
 };
 
+struct radius_accept_attr {
+	u8 type;
+	u16 len;
+	void *data;
+};
+
 /**
  * struct radius_session - Internal RADIUS server data for a session
  */
@@ -90,7 +96,7 @@ struct radius_session {
 	unsigned int macacl:1;
 	unsigned int t_c_filtering:1;
 
-	struct hostapd_radius_attr *accept_attr;
+	struct radius_accept_attr *accept_attr;
 
 	u32 t_c_timestamp; /* Last read T&C timestamp from user DB */
 };
@@ -394,6 +400,7 @@ static void radius_server_session_free(s
 	radius_msg_free(sess->last_reply);
 	os_free(sess->username);
 	os_free(sess->nas_ip);
+	os_free(sess->accept_attr);
 	os_free(sess);
 	data->num_sess--;
 }
@@ -554,6 +561,36 @@ radius_server_erp_find_key(struct radius
 }
 #endif /* CONFIG_ERP */
 
+static struct radius_accept_attr *
+radius_server_copy_attr(const struct hostapd_radius_attr *data)
+{
+	const struct hostapd_radius_attr *attr;
+	struct radius_accept_attr *attr_new;
+	size_t data_size = 0;
+	void *data_buf;
+	int n_attr = 1;
+
+	for (attr = data; attr; attr = attr->next) {
+		n_attr++;
+		data_size += wpabuf_len(attr->val);
+	}
+
+	attr_new = os_zalloc(n_attr * sizeof(*attr) + data_size);
+	if (!attr_new)
+		return NULL;
+
+	data_buf = &attr_new[n_attr];
+	for (n_attr = 0, attr = data; attr; attr = attr->next) {
+		struct radius_accept_attr *cur = &attr_new[n_attr++];
+
+		cur->type = attr->type;
+		cur->len = wpabuf_len(attr->val);
+		cur->data = memcpy(data_buf, wpabuf_head(attr->val), cur->len);
+		data_buf += cur->len;
+	}
+
+	return attr_new;
+}
 
 static struct radius_session *
 radius_server_get_new_session(struct radius_server_data *data,
@@ -607,7 +644,7 @@ radius_server_get_new_session(struct rad
 		eap_user_free(tmp);
 		return NULL;
 	}
-	sess->accept_attr = tmp->accept_attr;
+	sess->accept_attr = radius_server_copy_attr(tmp->accept_attr);
 	sess->macacl = tmp->macacl;
 	eap_user_free(tmp);
 
@@ -1123,11 +1160,10 @@ radius_server_encapsulate_eap(struct rad
 	}
 
 	if (code == RADIUS_CODE_ACCESS_ACCEPT) {
-		struct hostapd_radius_attr *attr;
-		for (attr = sess->accept_attr; attr; attr = attr->next) {
-			if (!radius_msg_add_attr(msg, attr->type,
-						 wpabuf_head(attr->val),
-						 wpabuf_len(attr->val))) {
+		struct radius_accept_attr *attr;
+		for (attr = sess->accept_attr; attr->data; attr++) {
+			if (!radius_msg_add_attr(msg, attr->type, attr->data,
+						 attr->len)) {
 				wpa_printf(MSG_ERROR, "Could not add RADIUS attribute");
 				radius_msg_free(msg);
 				return NULL;
@@ -1221,11 +1257,10 @@ radius_server_macacl(struct radius_serve
 	}
 
 	if (code == RADIUS_CODE_ACCESS_ACCEPT) {
-		struct hostapd_radius_attr *attr;
-		for (attr = sess->accept_attr; attr; attr = attr->next) {
-			if (!radius_msg_add_attr(msg, attr->type,
-						 wpabuf_head(attr->val),
-						 wpabuf_len(attr->val))) {
+		struct radius_accept_attr *attr;
+		for (attr = sess->accept_attr; attr->data; attr++) {
+			if (!radius_msg_add_attr(msg, attr->type, attr->data,
+						 attr->len)) {
 				wpa_printf(MSG_ERROR, "Could not add RADIUS attribute");
 				radius_msg_free(msg);
 				return NULL;
@@ -2527,7 +2562,7 @@ static int radius_server_get_eap_user(vo
 	ret = data->get_eap_user(data->conf_ctx, identity, identity_len,
 				 phase2, user);
 	if (ret == 0 && user) {
-		sess->accept_attr = user->accept_attr;
+		sess->accept_attr = radius_server_copy_attr(user->accept_attr);
 		sess->remediation = user->remediation;
 		sess->macacl = user->macacl;
 		sess->t_c_timestamp = user->t_c_timestamp;