--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlib/conv_layers/IPConvergenceLayer.cc	Thu Apr 21 14:57:45 2011 +0100
@@ -0,0 +1,78 @@
+/*
+ *    Copyright 2004-2006 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 <oasys/io/NetUtils.h>
+#include "IPConvergenceLayer.h"
+
+namespace dtn {
+
+/**
+ * Parse a next hop address specification of the form
+ * HOST[:PORT?].
+ *
+ * @return true if the conversion was successful, false
+ */
+bool
+IPConvergenceLayer::parse_nexthop(const char* nexthop,
+                                  in_addr_t* addr, u_int16_t* port)
+{
+    const char* host;
+    std::string tmp;
+
+    *addr = INADDR_NONE;
+    *port = 0;
+
+    // first see if there's a colon in the string -- if so, it should
+    // separate the hostname and port, if not, then the whole string
+    // should be a hostname.
+    //
+    // note that it is invalid to have more than one colon in the
+    // string, as caught by the check after calling strtoul
+    const char* colon = strchr(nexthop, ':');
+    if (colon != NULL) {
+        char* endstr;
+        u_int32_t portval = strtoul(colon + 1, &endstr, 10);
+        
+        if (*endstr != '\0' || portval > 65535) {
+            log_warn("invalid port %s in next hop '%s'",
+                     colon + 1, nexthop);
+            return false;
+        }
+
+        *port = (u_int16_t)portval;
+        
+        tmp.assign(nexthop, colon - nexthop);
+        host = tmp.c_str();
+    } else {
+        host = nexthop;
+    }
+
+    // now look up the hostname
+    if (oasys::gethostbyname(host, addr) != 0) {
+        log_warn("can't lookup hostname '%s' in next hop %s",
+                 host, nexthop);
+        return false;
+    }
+    
+    return true;
+}
+    
+
+} // namespace dtn