Make resends less aggressive.

We now limit resends to just 3 copies, both for requests and updates,
since there are enough mechanisms in the protocol to handle packet
loss.

resend.c

@@ -104,7 +104,7 @@ record_resend(int kind, const unsigned char *prefix, unsigned char plen,
         else if(delay)
             resend->delay = delay;
         resend->time = now;
-        resend->max = kind == RESEND_REQUEST ? 128 : UPDATE_MAX;
+        resend->max = RESEND_MAX;
         if(id && memcmp(resend->id, id, 8) == 0 &&
            seqno_compare(resend->seqno, seqno) > 0) {
             return 0;
@@ -121,7 +121,7 @@ record_resend(int kind, const unsigned char *prefix, unsigned char plen,
         if(resend == NULL)
             return -1;
         resend->kind = kind;
-        resend->max = kind == RESEND_REQUEST ? 128 : UPDATE_MAX;
+        resend->max = RESEND_MAX;
         resend->delay = delay;
         memcpy(resend->prefix, prefix, 16);
         resend->plen = plen;

resend.h

@@ -21,7 +21,7 @@ THE SOFTWARE.
 */
 
 #define REQUEST_TIMEOUT 65000
-#define UPDATE_MAX 4
+#define RESEND_MAX 3
 
 #define RESEND_REQUEST 1
 #define RESEND_UPDATE 2