oc_tls:fix race between DTLS close and init logic

Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>

security/oc_tls.c

@@ -248,6 +248,35 @@ is_peer_active(oc_tls_peer_t *peer)
 
 static oc_event_callback_retval_t oc_tls_inactive(void *data);
 
+#ifdef OC_CLIENT
+static void
+oc_tls_free_invalid_peer(oc_tls_peer_t *peer)
+{
+  OC_DBG("\noc_tls: removing invalid peer");
+  oc_list_remove(tls_peers, peer);
+
+  oc_ri_remove_timed_event_callback(peer, oc_tls_inactive);
+
+  mbedtls_ssl_free(&peer->ssl_ctx);
+  oc_message_t *message = (oc_message_t *)oc_list_pop(peer->send_q);
+  while (message != NULL) {
+    oc_message_unref(message);
+    message = (oc_message_t *)oc_list_pop(peer->send_q);
+  }
+  message = (oc_message_t *)oc_list_pop(peer->recv_q);
+  while (message != NULL) {
+    oc_message_unref(message);
+    message = (oc_message_t *)oc_list_pop(peer->recv_q);
+  }
+#ifdef OC_PKI
+  oc_free_string(&peer->public_key);
+#endif /* OC_PKI */
+  mbedtls_ssl_config_free(&peer->ssl_conf);
+  oc_etimer_stop(&peer->timer.fin_timer);
+  oc_memb_free(&tls_peers_s, peer);
+}
+#endif /* OC_CLIENT */
+
 static void
 oc_tls_free_peer(oc_tls_peer_t *peer, bool inactivity_cb)
 {
@@ -1573,8 +1602,17 @@ write_application_data(oc_tls_peer_t *peer)
 static void
 oc_tls_init_connection(oc_message_t *message)
 {
-  oc_tls_peer_t *peer =
-    oc_tls_add_peer(&message->endpoint, MBEDTLS_SSL_IS_CLIENT);
+  oc_tls_peer_t *peer = oc_tls_get_peer(&message->endpoint);
+
+  if (peer && peer->role != MBEDTLS_SSL_IS_CLIENT) {
+    oc_tls_free_invalid_peer(peer);
+    peer = NULL;
+  }
+
+  if (!peer) {
+    peer = oc_tls_add_peer(&message->endpoint, MBEDTLS_SSL_IS_CLIENT);
+  }
+
   if (peer) {
     oc_message_t *duplicate = oc_list_head(peer->send_q);
     while (duplicate != NULL) {