eap-radius: Add RADIUS Accounting session ID to Access-Request messages

This allows e.g. associating database entries for IP leases and
accounting directly from the start.

Fixes #2853.

src/libcharon/plugins/eap_radius/eap_radius.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012-2017 Tobias Brunner
+ * Copyright (C) 2012-2018 Tobias Brunner
  * Copyright (C) 2009 Martin Willi
  * HSR Hochschule fuer Technik Rapperswil
  *
@@ -156,7 +156,7 @@ void eap_radius_build_attributes(radius_message_t *request)
 {
 	ike_sa_t *ike_sa;
 	host_t *host;
-	char buf[40], *station_id_fmt;;
+	char buf[40], *station_id_fmt, *session_id;
 	uint32_t value;
 	chunk_t chunk;
 
@@ -202,6 +202,14 @@ void eap_radius_build_attributes(radius_message_t *request)
 		host = ike_sa->get_other_host(ike_sa);
 		snprintf(buf, sizeof(buf), station_id_fmt, host);
 		request->add(request, RAT_CALLING_STATION_ID, chunk_from_str(buf));
+
+		session_id = eap_radius_accounting_session_id(ike_sa);
+		if (session_id)
+		{
+			request->add(request, RAT_ACCT_SESSION_ID,
+						 chunk_from_str(session_id));
+			free(session_id);
+		}
 	}
 }
 

src/libcharon/plugins/eap_radius/eap_radius_accounting.c

@@ -1070,8 +1070,27 @@ eap_radius_accounting_t *eap_radius_accounting_create()
 	return &this->public;
 }
 
-/**
- * See header
+/*
+ * Described in header
+ */
+char *eap_radius_accounting_session_id(ike_sa_t *ike_sa)
+{
+	entry_t *entry;
+	char *sid = NULL;
+
+	if (singleton)
+	{
+		singleton->mutex->lock(singleton->mutex);
+		entry = get_or_create_entry(singleton, ike_sa->get_id(ike_sa),
+									ike_sa->get_unique_id(ike_sa));
+		sid = strdup(entry->sid);
+		singleton->mutex->unlock(singleton->mutex);
+	}
+	return sid;
+}
+
+/*
+ * Described in header
  */
 void eap_radius_accounting_start_interim(ike_sa_t *ike_sa, uint32_t interval)
 {

src/libcharon/plugins/eap_radius/eap_radius_accounting.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Tobias Brunner
+ * Copyright (C) 2017-2018 Tobias Brunner
  * HSR Hochschule fuer Technik Rapperswil
  *
  * Copyright (C) 2012 Martin Willi
@@ -49,6 +49,14 @@ struct eap_radius_accounting_t {
  */
 eap_radius_accounting_t *eap_radius_accounting_create();
 
+/**
+ * Get the Accounting session ID for the given IKE_SA.
+ *
+ * @param ike_sa			IKE_SA for which to determine the session ID
+ * @return					allocated session ID
+ */
+char *eap_radius_accounting_session_id(ike_sa_t *ike_sa);
+
 /**
  * Schedule Accounting interim updates for the given IKE_SA.
  *