--- gvpe/src/vpn_dns.C	2005/03/16 14:56:32	1.35
+++ gvpe/src/vpn_dns.C	2006/11/22 21:26:41	1.41
@@ -16,9 +16,13 @@
  
     You should have received a copy of the GNU General Public License
     along with gvpe; if not, write to the Free Software
-    Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+    Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+// TODO: EDNS0 option to increase dns mtu?
+// TODO: re-write dns packet parsing/creation using a safe mem-buffer
+//       to ensure no buffer overflows or similar problems.
+
 #include "config.h"
 
 #if ENABLE_DNS
@@ -49,16 +53,11 @@
 #define MAX_POLL_INTERVAL 5.  // how often to poll minimally when the server has no data
 #define ACTIVITY_INTERVAL 5.
 
-#define TIMEOUT_FACTOR 2.
-
 #define INITIAL_TIMEOUT     0.1 // retry timeouts
-#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
+#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
 
-#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
 #define MAX_SEND_INTERVAL 2. // optimistic?
 
-#define LATENCY_FACTOR   0.5 // RTT * LATENCY_FACTOR == sending rate
-#define MAX_OUTSTANDING  100 // max. outstanding requests
 #define MAX_WINDOW      1000 // max. for MAX_OUTSTANDING, and backlog
 #define MAX_BACKLOG     (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
 
@@ -464,6 +463,8 @@
 
 bool dns_cfg::valid ()
 {
+  // although the protocol itself allows for some configurability,
+  // only the following encoding/decoding settings are implemented.
   return id1 == 'G'
       && id2 == 'V'
       && id3 == 'P'
@@ -772,6 +773,7 @@
   for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
     if (SEQNO_EQ (rcvseq, (*i)->seqno))
       {
+        //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
         // enter the packet into our input stream
         r = *i;
 
@@ -779,6 +781,7 @@
         for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
           if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
             {
+              //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
               delete *j;
               rcvpq.erase (j);
               break;
@@ -1016,6 +1019,7 @@
         connection *c = dns->c;
         int seqno = (*i)->seqno;
         u8 data[MAXSIZE], *datap = data;
+        //printf ("rcv pkt %x\n", seqno);//D
 
         if ((*i)->retry)
           {
@@ -1035,11 +1039,11 @@
             if (latency < dns->min_latency)
               dns->min_latency = latency;
 
-            if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
-              dns->send_interval = dns->min_latency * LATENCY_FACTOR;
+            if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
+              dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
 
-            if (dns->send_interval < MIN_SEND_INTERVAL)
-              dns->send_interval = MIN_SEND_INTERVAL;
+            if (dns->send_interval < conf.dns_send_interval)
+              dns->send_interval = conf.dns_send_interval;
           }
 
         delete *i;
@@ -1230,15 +1234,13 @@
               send = r;
 
               r->retry++;
-              r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR);
+              r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
+              //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - NOW);//D
 
               // the following code changes the query section a bit, forcing
               // the forwarder to generate a new request
               if (r->stdhdr)
-                {
-                  //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
-                  //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
-                }
+                encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
             }
         }
       else
@@ -1259,7 +1261,7 @@
               send->gen_syn_req ();
             }
         }
-      else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
+      else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
                && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
         {
           if (last_sent + send_interval <= NOW)
@@ -1273,7 +1275,8 @@
 
               send = new dns_snd (this);
               send->gen_stream_req (sndseq, snddq);
-              send->timeout = NOW + min_latency * TIMEOUT_FACTOR;
+              send->timeout = NOW + min_latency * conf.dns_timeout_factor;
+              //printf ("SEND %x (%f)\n", send->seqno, send->timeout - NOW, min_latency, conf.dns_timeout_factor);//D
 
               sndseq = (sndseq + 1) & SEQNO_MASK;
             }
@@ -1299,6 +1302,7 @@
         rcvpq.size ());
 
   // TODO: no idea when this happens, but when next < NOW, we have a problem
+  // doesn't seem to happen anymore
   if (next < NOW + 0.001)
     next = NOW + 0.1;