Client-Server interaction

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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