add receiver loop, service multiplexing, common.h

* Service multiplexing

  Broadcaster call signature is changed to

  broadcaster host service [message]

  to acommodate multiple sevices listening on the same port for
  broadcast information.

* Receiver Loop

  Listener now loops infinitely instead of returning after the first
  packet. For each packet with the content service[,message] the
  programm

  service [message]

  will be executed. Upward directory traversal is prohibited (and
  detected).

  To prevent DoS only one service program runs concurrently.

* Common.h

  Port numbers and maximum message sizes are now stored in
  common.h. Broascaster respects max. message size.

1 files changed, 8 insertions, 0 deletions

diff --git a/common.h b/common.h
new file mode 100644
index 0000000..c64c764
--- /dev/null
+++ b/common.h
@@ -0,0 +1,8 @@
+#ifndef UDP_BROADCAST_COMMON
+#define UDP_BROADCAST_COMMON
+
+#define SERVERPORT 4950    // the port users will be connecting to
+#define SERVERPORT_S "4950"
+#define MAXBUFLEN 100
+
+#endif // UDP_BROADCAST_COMMON