Control Files

Helpers to implement control file operations. More...

Collaboration diagram for Control Files:

Detailed Description

Helpers to implement control file operations.

A control file is a special file that takes in commands as text input and performs actions based on those commands.

Command Format

Commands should be formatted as follows:

command1 arg1 arg2 arg3 ... && command2 arg1 arg2 ... && ...

Data Structures
struct	ctl_t
	Structure defining a ctl command. More...

Macros
#define	CTL_MAX_BUFFER   0x1000
	Maximum size of the buffer used for argument parsing.
#define	CTL_STANDARD_WRITE_DEFINE(name, ...)
	Helper macro to define a standard ctl write function.
#define	CTL_STANDARD_OPS_DEFINE(name, ...)
	Helper macro to define a standard ctl file operations structure.

Typedefs
typedef uint64_t(*	ctl_func_t) (file_t *file, uint64_t, const char **)
	Type definition for a ctl function.

Functions
uint64_t	ctl_dispatch (ctl_t ctls[], file_t *file, const void *buffer, size_t count)
	Dispatch a ctl command.

Macro Definition Documentation

CTL_MAX_BUFFER

#define CTL_MAX_BUFFER   0x1000

Maximum size of the buffer used for argument parsing.

Definition at line 28 of file ctl.h.

CTL_STANDARD_WRITE_DEFINE

#define CTL_STANDARD_WRITE_DEFINE	(		name,
			...
	)

Value:

    static ctl_t name##ctls[] = __VA_ARGS__; \
    static size_t name(file_t* file, const void* buffer, size_t count, size_t* offset) \
    { \
        UNUSED(offset); \
        return ctl_dispatch(name##ctls, file, buffer, count); \
    }

Helper macro to define a standard ctl write function.

This macro defines a write function that dispatches commands to a given array of ctl_t structures.

Parameters

name	The name of the ctl write function.
...	The ctl array to dispatch commands to.

Definition at line 38 of file ctl.h.

CTL_STANDARD_OPS_DEFINE

#define CTL_STANDARD_OPS_DEFINE	(		name,
			...
	)

Value:

    CTL_STANDARD_WRITE_DEFINE(name##write, __VA_ARGS__) \
    static file_ops_t name = (file_ops_t){ \
        .write = name##write, \
    };

Helper macro to define a standard ctl file operations structure.

This macro defines a file operations structure with all standard ctl operations implemented.

Parameters

name	The name of the ctl file operations structure.
...	The ctl array to dispatch commands to.

Definition at line 54 of file ctl.h.

Typedef Documentation

ctl_func_t

typedef uint64_t(* ctl_func_t) (file_t *file, uint64_t, const char **)

Type definition for a ctl function.

Definition at line 63 of file ctl.h.

Function Documentation

ctl_dispatch()

uint64_t ctl_dispatch	(	ctl_t	ctls[],
		file_t *	file,
		const void *	buffer,
		size_t	count
	)

Dispatch a ctl command.

Parameters

ctls	The array of ctl commands to dispatch to, terminated by an entry with a NULL name.
file	The file the ctl command was sent to.
buffer	The buffer containing the command and its arguments.
count	The number of bytes in the buffer.

Returns

On success, the number of bytes processed (count). On failure, ERR and errno is set.