Implement unsatisfied_request.

request.c

@@ -114,6 +114,23 @@ record_request(const unsigned char *prefix, unsigned char plen,
     }
 }
 
+int
+unsatisfied_request(const unsigned char *prefix, unsigned char plen,
+                    unsigned short seqno, unsigned short router_hash)
+{
+    struct request *request;
+
+    request = find_request(prefix, plen, NULL);
+    if(request == NULL)
+        return 0;
+
+    if(request->router_hash != router_hash ||
+       seqno_compare(request->seqno, seqno) <= 0)
+        return 1;
+
+    return 0;
+}
+
 int
 satisfy_request(const unsigned char *prefix, unsigned char plen,
                 unsigned short seqno, unsigned short router_hash,

request.h

@@ -40,6 +40,8 @@ struct request *find_request(const unsigned char *prefix, unsigned char plen,
 int record_request(const unsigned char *prefix, unsigned char plen,
                    unsigned short seqno, unsigned short router_hash,
                    struct network *net, int resend);
+int unsatisfied_request(const unsigned char *prefix, unsigned char plen,
+                        unsigned short seqno, unsigned short router_hash);
 int satisfy_request(const unsigned char *prefix, unsigned char plen,
                     unsigned short seqno, unsigned short router_hash,
                     struct network *net);