examples: Update connection handling

Add function for removing connection.

Author: LukasWoodtli

transport/tinydtls/connection.c

@@ -564,3 +564,27 @@ uint8_t lwm2m_buffer_send(void *sessionH, uint8_t *buffer, size_t length, void *
 }
 
 bool lwm2m_session_is_equal(void *session1, void *session2, void *userData) { return (session1 == session2); }
+
+void lwm2m_session_remove(void *sessionH) {
+    lwm2m_dtls_connection_t *connP = (lwm2m_dtls_connection_t *)sessionH;
+    dtls_app_context_t *appContext = (dtls_app_context_t *)connP->dtlsContext;
+    lwm2m_dtls_connection_t *connIter;
+
+    connIter = appContext->connList;
+
+    if (connIter == NULL) {
+        return;
+    }
+    if (connIter == sessionH) {
+        /* First element */
+        free(sessionH);
+        appContext->connList = NULL;
+        return;
+    }
+
+    while (connIter->next != connP)
+        ;
+    connIter->next = connP->next;
+
+    free(connP);
+}

transport/udp/connection.c

@@ -26,6 +26,8 @@
 #include <sys/socket.h>
 #include <sys/types.h>
 
+static lwm2m_connection_t *connectionList = NULL;
+
 static int find_and_bind_to_address(struct addrinfo *res) {
     int s = -1;
     for (struct addrinfo *p = res; p != NULL && s == -1; p = p->ai_next) {
@@ -80,7 +82,7 @@ int lwm2m_create_socket(const char *portStr, int addressFamily) {
 lwm2m_connection_t *lwm2m_connection_find(lwm2m_connection_t *connList, struct sockaddr_storage *addr, size_t addrLen) {
     lwm2m_connection_t *connP;
 
-    connP = connList;
+    connP = connectionList;
     while (connP != NULL) {
         if ((connP->addrLen == addrLen) && (memcmp(&(connP->addr), addr, addrLen) == 0)) { // NOSONAR
             return connP;
@@ -100,7 +102,9 @@ lwm2m_connection_t *lwm2m_connection_new_incoming(lwm2m_connection_t *connList,
         connP->sock = sock;
         memcpy(&(connP->addr), addr, addrLen);
         connP->addrLen = addrLen;
-        connP->next = connList;
+        connP->next = connectionList;
+
+        connectionList = connP;
     }
 
     return connP;
@@ -139,10 +143,10 @@ void lwm2m_connection_free(lwm2m_connection_t *connList) {
     while (connList != NULL) {
         lwm2m_connection_t *nextP;
 
-        nextP = connList->next;
-        lwm2m_free(connList);
+        nextP = connectionList->next;
+        lwm2m_free(connectionList);
 
-        connList = nextP;
+        connectionList = nextP;
     }
 }
 
@@ -214,4 +218,25 @@ bool lwm2m_session_is_equal(void *session1, void *session2, void *userData) {
     return (session1 == session2);
 }
 
-void lwm2m_session_remove(void *session_h) { (void)session_h; /* unused */ }
+void lwm2m_session_remove(void *sessionH) {
+    lwm2m_connection_t *connP = (lwm2m_connection_t *)sessionH;
+    lwm2m_connection_t *connIter;
+
+    connIter = connectionList;
+
+    if (connIter == NULL) {
+        return;
+    }
+    if (connIter == sessionH) {
+        /* First element */
+        free(sessionH);
+        connectionList = NULL;
+        return;
+    }
+
+    while (connIter->next != connP)
+        ;
+    connIter->next = connP->next;
+
+    free(connP);
+}