--- deliantra/server/socket/lowlevel.C	2007/05/28 21:22:26	1.42
+++ deliantra/server/socket/lowlevel.C	2007/06/09 22:54:04	1.43
@@ -46,10 +46,12 @@
 # include <netinet/tcp.h>
 #endif
 
-// use a really low timeout, as it doesn't cost any bandwidth, and you can
-// easily die in 20 seconds...
-#define SOCKET_TIMEOUT1 10 * 1000
-#define SOCKET_TIMEOUT2 20 * 1000
+// disconnect a socket after this many seconds without an ack
+#define SOCKET_TIMEOUT 8.
+
+// force a packet when idle for more than this many seconds,
+// forcing an ack regularly.
+#define IDLE_PING 2.
 
 void
 client::flush ()
@@ -58,23 +60,27 @@
     return;
 
 #ifdef __linux__
-  // check time of last ack, and, if too old, kill connection
-  struct tcp_info tcpi;
-  socklen_t len = sizeof (tcpi);
-
-  if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
+  // check about once per second, spread evenly over all clients
+  if (!((pticks + fd) & 7))
     {
-      unsigned int diff = tcpi.tcpi_last_ack_recv - tcpi.tcpi_last_data_sent;
-
-      rtt    = tcpi.tcpi_rtt;
-      rttvar = tcpi.tcpi_rttvar;
+      // check time of last ack, and, if too old, kill connection
+      struct tcp_info tcpi;
+      socklen_t len = sizeof (tcpi);
 
-      if (tcpi.tcpi_unacked && SOCKET_TIMEOUT1 < diff && diff < 0x80000000UL   // ack delayed for 20s
-          && SOCKET_TIMEOUT2 < tcpi.tcpi_last_data_sent)       // no data sent for 10s
+      if (!getsockopt (fd, IPPROTO_TCP, TCP_INFO, &tcpi, &len) && len == sizeof (tcpi))
         {
-          LOG (llevDebug, "Connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
-               (unsigned) tcpi.tcpi_last_ack_recv, (unsigned) tcpi.tcpi_last_data_sent, (unsigned) tcpi.tcpi_unacked);
-          destroy ();
+          rtt    = tcpi.tcpi_rtt;
+          rttvar = tcpi.tcpi_rttvar;
+
+          if (tcpi.tcpi_last_ack_recv > int (SOCKET_TIMEOUT * 1000))
+            {
+              send_msg (NDI_RED, "connection-timeout", "safety disconnect due to tcp/ip timeout (no packets received)");
+              write_outputbuffer ();
+
+              LOG (llevDebug, "connection on fd %d closed due to ack timeout (%u/%u/%u)\n", fd,
+                   (unsigned)tcpi.tcpi_last_ack_recv, (unsigned)tcpi.tcpi_last_data_sent, (unsigned)tcpi.tcpi_unacked);
+              destroy ();
+            }
         }
     }
 #endif
@@ -86,9 +92,24 @@
    * is called to write it out.
    */
 
-  if (!outputbuffer.len || socket_ev.poll () & PE_W)
+  // write a nop to the socket at least every IDLE_NOP seconds.
+  if (!outputbuffer.len)
+    {
+      if (last_send + IDLE_PING <= NOW)
+        {
+          // this is a bit ugly, but map1/map1a seem to be the only
+          // nop'able commands and they are quite small.
+          packet sl (mapmode == Map1Cmd ? "map1" : "map1a");
+          send_packet (sl);
+        }
+      else
+        return;
+    }
+
+  if (socket_ev.poll () & PE_W)
     return;
 
+  last_send = NOW;
   write_outputbuffer ();
 }
 
@@ -108,10 +129,6 @@
             outputbuffer.start = 0;
 
           outputbuffer.len -= res;
-#ifdef CS_LOGSTATS
-          cst_tot.obytes += res;
-          cst_lst.obytes += res;
-#endif
         }
       else if (res == 0)
         {
@@ -378,9 +395,6 @@
         {
           inbuf_len += amount;
 
-          cst_tot.ibytes += amount;
-          cst_lst.ibytes += amount;
-
           cmd_ev.start ();
         }
     }
@@ -608,38 +622,3 @@
   cur += len;
 }
 
-/******************************************************************************
- *
- * statistics logging functions.
- *
- ******************************************************************************/
-
-#ifdef CS_LOGSTATS
-
-/* cst_tot is for the life of the server, cst_last is for the last series of
- * stats
- */
-CS_Stats cst_tot, cst_lst;
-
-/**
- * Writes out the gathered stats.  We clear cst_lst.
- */
-void
-write_cs_stats (void)
-{
-  time_t now = time (NULL);
-
-  /* If no connections recently, don't both to log anything */
-  if (cst_lst.ibytes == 0 && cst_lst.obytes == 0)
-    return;
-
-  /* CSSTAT is put in so scripts can easily find the line */
-  LOG (llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
-       ctime (&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
-       now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes, cst_lst.max_conn, now - cst_lst.time_start);
-  cst_lst.ibytes = 0;
-  cst_lst.obytes = 0;
-  cst_lst.time_start = now;
-}
-#endif
-