--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/protocol.txt	Wed Jan 16 22:39:43 2008 +0100
@@ -0,0 +1,43 @@
+Client-Server interaction
+-------------------------
+
+To execute a server call, the client opens the daemon's UNIX domain
+socket (as specified by SYSCONFDIR/socket-file), and sends across the
+following data:
+
+Size	Type	Description
+1	int	Protocol number (always 2)
+2	int	Total length of all data
+1	int	Number of arguments following the command
+varies	string	Command name
+varies	strings	Arguments
+
+It then receives the following response from the server:
+
+Size	Type	Description
+1	int	Response code: one of the following
+		0: OK -- operation succeeded
+		1: Bad -- error in format or syntax
+		2: Error -- operation failed
+varies	string	Message
+
+
+Strings are encoded as:
+
+Size	Type	Description
+2	int	Length of string
+length	char	String data (no trailing NUL byte)
+
+All integers are unsigned, sent MSB first.
+
+Example:
+0x02                   Protocol version
+0x00 0x2E              Length of everything from this point on
+0x02                   Number of arguments to command
+0x00 0x0A              Length of command name (command name will become a
+                       number later)
+listdomain             Command name
+0x00 0x15              Length of first argument
+mailtest.somesuch.dom  First argument
+0x00 0x08              Length of second argument
+mailtest               Second argument