Merge pull request #839 from namib-project/server_session_events

Add events for server session state management

examples/coap-client.c

@@ -357,6 +357,8 @@ event_handler(coap_session_t *session COAP_UNUSED,
   case COAP_EVENT_SESSION_CONNECTED:
   case COAP_EVENT_SESSION_FAILED:
   case COAP_EVENT_PARTIAL_BLOCK:
+  case COAP_EVENT_SERVER_SESSION_NEW:
+  case COAP_EVENT_SERVER_SESSION_DEL:
   default:
     break;
   }

examples/coap-server.c

@@ -1632,6 +1632,8 @@ proxy_event_handler(coap_session_t *session,
   case COAP_EVENT_SESSION_CONNECTED:
   case COAP_EVENT_SESSION_FAILED:
   case COAP_EVENT_PARTIAL_BLOCK:
+  case COAP_EVENT_SERVER_SESSION_NEW:
+  case COAP_EVENT_SERVER_SESSION_DEL:
   default:
     break;
   }

include/coap3/coap_event.h

@@ -56,7 +56,32 @@ typedef enum coap_event_t {
 /**
  * (Q-)BLOCK receive errors
  */
-  COAP_EVENT_PARTIAL_BLOCK     = 0x3001
+  COAP_EVENT_PARTIAL_BLOCK     = 0x3001,
+
+/**
+ * @defgroup srv_sess_state_events Server session state management events
+ * @{
+ */
+
+/**
+ * Called in the CoAP IO loop if a new *server-side* session is created due
+ * to an incoming connection.
+ *
+ * Note that the session might not be a fully established connection yet,
+ * it might also refer to, e.g., a DTLS session in a handshake stage.
+ */
+  COAP_EVENT_SERVER_SESSION_NEW = 0x4001,
+
+/**
+ * Called in the CoAP IO loop if a server session is deleted (e.g., due to
+ * inactivity or because the maximum number of idle sessions was exceeded).
+ *
+ * The session will still contain valid data when the event handler is
+ * called.
+ */
+  COAP_EVENT_SERVER_SESSION_DEL = 0x4002
+
+/** @} */
 } coap_event_t;
 
 /**

man/coap_handler.txt.in

@@ -207,6 +207,15 @@ COAP_EVENT_TCP_FAILED         0x1003
 COAP_EVENT_SESSION_CONNECTED  0x2001
 COAP_EVENT_SESSION_CLOSED     0x2002
 COAP_EVENT_SESSION_FAILED     0x2003
+/**
+ * (Q-)BLOCK receive errors
+ */
+COAP_EVENT_PARTIAL_BLOCK      0x3001
+/**
+ * Server session state management events
+ */
+COAP_EVENT_SERVER_SESSION_NEW 0x4001
+COAP_EVENT_SERVER_SESSION_DEL 0x4002
 ----
 
 EXAMPLES

src/coap_io.c

@@ -1121,6 +1121,7 @@ coap_io_prepare_io(coap_context_t *ctx,
           s->delayqueue == NULL &&
           (s->last_rx_tx + session_timeout <= now ||
            s->state == COAP_SESSION_STATE_NONE)) {
+        coap_handle_event(ctx, COAP_EVENT_SERVER_SESSION_DEL, s);
         coap_session_free(s);
       } else {
         if (s->type == COAP_SESSION_TYPE_SERVER && s->ref == 0 && s->delayqueue == NULL) {

src/coap_session.c

@@ -635,11 +635,13 @@ coap_endpoint_get_session(coap_endpoint_t *endpoint,
 
   if (endpoint->context->max_idle_sessions > 0 &&
       num_idle >= endpoint->context->max_idle_sessions) {
+    coap_handle_event(oldest->context, COAP_EVENT_SERVER_SESSION_DEL, oldest);
     coap_session_free(oldest);
   }
   else if (oldest_hs) {
     coap_log(LOG_WARNING, "***%s: Incomplete session timed out\n",
              coap_session_str(oldest_hs));
+    coap_handle_event(oldest_hs->context, COAP_EVENT_SERVER_SESSION_DEL, oldest_hs);
     coap_session_free(oldest_hs);
   }
 
@@ -700,6 +702,7 @@ coap_endpoint_get_session(coap_endpoint_t *endpoint,
       return NULL;
     }
   }
+
   session = coap_make_session(endpoint->proto, COAP_SESSION_TYPE_SERVER,
                               &addr_hash, &packet->addr_info.local,
                               &packet->addr_info.remote,
@@ -714,6 +717,7 @@ coap_endpoint_get_session(coap_endpoint_t *endpoint,
     SESSIONS_ADD(endpoint->sessions, session);
     coap_log(LOG_DEBUG, "***%s: session %p: new incoming session\n",
              coap_session_str(session), (void *)session);
+    coap_handle_event(session->context, COAP_EVENT_SERVER_SESSION_NEW, session);
   }
   return session;
 }
@@ -1251,6 +1255,9 @@ coap_session_t *coap_new_server_session(
              coap_session_str(session), (void *)session);
     /* Returned session may already have been released and is now NULL */
     session = coap_session_accept(session);
+    if(session) {
+      coap_handle_event(session->context, COAP_EVENT_SERVER_SESSION_NEW, session);
+    }
   }
   return session;