A new config file option to connect to tcp and udp at once has been added. Also some clarifications have been put into the sample config file.

opentracker.c

@@ -312,6 +312,11 @@ int parse_configfile( char * config_filename ) {
     /* Scan for commands */
     if(!byte_diff(p,15,"tracker.rootdir" ) && isspace(p[15])) {
       set_config_option( &g_serverdir, p+16 );
+    } else if(!byte_diff(p,14,"listen.tcp_udp" ) && isspace(p[14])) {
+      uint16_t tmpport = 6969;
+      if( !scan_ip4_port( p+15, tmpip, &tmpport )) goto parse_error;
+      ot_try_bind( tmpip, tmpport, FLAG_TCP ); ++bound;
+      ot_try_bind( tmpip, tmpport, FLAG_UDP ); ++bound;
     } else if(!byte_diff(p,10,"listen.tcp" ) && isspace(p[10])) {
       uint16_t tmpport = 6969;
       if( !scan_ip4_port( p+11, tmpip, &tmpport )) goto parse_error;

opentracker.conf.sample

@@ -1,29 +1,28 @@
 # opentracker config file
 #
 
-# I)   ip addresses for tcp connections, either bind to INADDR_ANY port 6969
-#      (when no shell option is present)
+# I)   Address opentracker will listen on, using both, tcp AND udp family
+#      (note, that port 6969 is implicite if ommitted).
 #
-# listen.tcp 0.0.0.0
+#      If no listen option is given (here or on the command line), opentracker
+#      listens on 0.0.0.0:6969 tcp and udp.
 #
-#      or specify them one by one (shell option -i 192.168.0.1 -p 6969)
-#      (note, that :6969 is implicite)
+# listen.tcp_udp 0.0.0.0
+# listen.tcp_udp 192.168.0.1:80
+# listen.tcp_udp 10.0.0.5:6969
 #
-# listen.tcp 192.168.0.1
-# listen.tcp 192.168.0.2:6969
-# listen.tcp 192.168.0.3:6969
-
-# II)  the same goes for udp connections (shell option -i 192.168.0.1 -P 6969)
+#      To only listen on tcp or udp family ports, list them this way:
 #
+# listen.tcp 0.0.0.0
 # listen.udp 192.168.0.1:6969
 #
 #      Note, that using 0.0.0.0 for udp sockets may yield surprising results.
 #      An answer packet sent on that socket will not necessarily have the
 #      source address that the requesting client may expect, but any address
-#      on that interface
+#      on that interface.
 #
 
-# III) If opentracker runs in a non-open mode, point it to files containing
+# II)  If opentracker runs in a non-open mode, point it to files containing
 #      all torrent hashes that it will serve (shell option -w)
 #
 # access.whitelist /path/to/whitelist
@@ -33,28 +32,31 @@
 # access.blacklist ./blacklist
 #
 #      It is pointless and hence not possible to compile black AND white
-#      listing, so choose one of those options. File format is straight
-#      forward: "<hex info hash>\n<hex info hash>\n..."
+#      listing, so choose one of those options at compile time. File format
+#      is straight forward: "<hex info hash>\n<hex info hash>\n..."
 #
 
-# IV)  ip address to listen for incoming and sending out outgoing live sync
-#      packets (shell option -i 192.168.0.1 -s 9696), port 9696 is default.
+# III) Live sync uses udp multicast packets to keep a cluster of opentrackers
+#      synchronized. This option tells opentracker which port to listen for
+#      incoming live sync packets. The ip address tells opentracker, on which
+#      interface to join the multicast group, those packets will arrive.
+#      (shell option -i 192.168.0.1 -s 9696), port 9696 is default.
 #
 # livesync.cluster.listen 192.168.0.1:9696
 #
 #      Note that two udp sockets will be opened. One on ip address 0.0.0.0
-#      port 9696, that will join the multicast group 224.23.42.1 for incoming
+#      port 9696, that will join the multicast group 224.0.42.23 for incoming
 #      udp packets and one on ip address 192.168.0.1 port 9696 for outgoing
 #      udp packets.
 #
 #      As of now one and only one ip address must be given, if opentracker
-#      was built with the WANT_SYNC_LIVE feature
+#      was built with the WANT_SYNC_LIVE feature.
 #
 
-# V)   Sync between trackers running in a cluster is restricted to packets
+# IV)  Sync between trackers running in a cluster is restricted to packets
 #      coming from trusted ip addresses. While source ip verification is far
 #      from perfect, the authors of opentracker trust in the correct
-#      application of tunnels, filters and LAN setups (shell option -A)
+#      application of tunnels, filters and LAN setups (shell option -A).
 #
 # livesync.cluster.node_ip 192.168.0.4
 # livesync.cluster.node_ip 192.168.0.5
@@ -66,13 +68,13 @@
 # batchsync.cluster.admin_ip 10.1.1.1
 #
 
-# VI)  Control directory where opentracker will chdir to. So all black/white
-#      list files may be put in that directory. (shell option -d)
+# V)   Control directory where opentracker will chdir to. So all black/white
+#      list files may be put in that directory (shell option -d).
 #
 # tracker.rootdir /usr/local/etc/opentracker
 #
 
-# VII) opentracker can be told to answer to a "GET / HTTP"-request with a
-#      redirect to another location (shell option -r)
+# VI)  opentracker can be told to answer to a "GET / HTTP"-request with a
+#      redirect to another location (shell option -r).
 #
 # tracker.redirect_url https://your.tracker.local/