diff -r 000000000000 -r 2b3e5ec03512 apps/tca_admin/libs/gateway_rpc.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/apps/tca_admin/libs/gateway_rpc.c	Thu Apr 21 14:57:45 2011 +0100
@@ -0,0 +1,119 @@
+/*
+ *    Copyright 2006 Intel Corporation
+ * 
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include <dtn-config.h>
+#endif
+
+#include "gateway_rpc.h"
+#include "gateway_prot.h"
+#include <sys/socket.h>             // needed for AF_INET
+#include <netdb.h>                  // needed for gethostbyname
+#include <string.h>
+#include <stdio.h>
+
+static const int DHT_PORT = 5852;
+
+///////////////////////////////////////////////////////////////////////////////
+// Functions for interfacing with OpenDHT
+
+// lookup hostname, store address in addr
+int
+lookup_host(const char* host, int port, struct sockaddr_in* addr)
+{
+    struct hostent* h = gethostbyname (host);
+    if (h == NULL) return 0;
+
+    bzero (addr, sizeof(struct sockaddr_in));
+    addr->sin_family = AF_INET;
+    addr->sin_port = htons(port);
+
+    // demmer: rewrote the following as a memcpy to avoid -Wcast-align bugs
+    //addr->sin_addr = *((struct in_addr *) h->h_addr);
+    memcpy(&addr->sin_addr, h->h_addr, sizeof(struct in_addr));
+    return 1;
+}
+
+
+// try to open connection to given dht node by addr
+CLIENT*
+get_connection(struct sockaddr_in* addr)
+{
+    int sockp = RPC_ANYSOCK;
+    CLIENT * c = clnttcp_create(addr, BAMBOO_DHT_GATEWAY_PROGRAM,
+                        BAMBOO_DHT_GATEWAY_VERSION, &sockp, 0, 0);
+    return c;
+}
+
+
+/*
+// try to open connection to given dht node by hostname
+static CLIENT*
+get_connection(const char* hostname)
+{
+    struct sockaddr_in addr;
+    if(lookup_host(hostname, DHT_PORT, &addr) < 0) return NULL;
+    return get_connection(addr);
+}
+*/
+
+
+// useful for probing a dht node to see if it's alive:
+int
+do_null_op(CLIENT* c)
+{
+    void* null_args = NULL;
+    void* res = bamboo_dht_proc_null_2(&null_args, c);
+    return (res != NULL);
+}
+
+
+// test dht node, printing status messages
+// if successful, addr contains a valid sockaddr_in
+int
+test_node(const char* hostname, struct sockaddr_in* addr)
+{
+    printf("   testing dht node %s... ", hostname);
+
+    // try to get host addr
+    if (!lookup_host(hostname, DHT_PORT, addr))
+    {
+        printf("lookup_host failed\n");
+        return 0;
+    }
+
+    // try to connect to node
+    // Note: This step seems to be insanely slow when it fails. Is there
+    // a way to timeout faster?
+    CLIENT* p_client = get_connection(addr);
+    if (p_client == NULL)
+    {
+        printf("get_connection failed\n");
+        return 0;
+    }
+
+    // try a null op
+    if (!do_null_op(p_client))
+    {
+        printf("null_op failed\n");
+        clnt_destroy(p_client);
+        return 0;
+    }
+
+    printf("succeeded.\n");
+    clnt_destroy(p_client);
+    return 1;
+}