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magma_flare.c File Reference

#include "magma.h"

Defines
#define	INCLUDE_FLARE_INTERNALS
#define	reduce_file_descriptors()   dbg(LOG_ERR, DEBUG_ERR, "Define a reduce_file_descriptor() function to manage FD starvation")
#define	STACK_DEPTH   20
Functions
int	magma_getattr (uid_t uid, gid_t gid, const char *path, struct stat *stbuf)
int	magma_stat (uid_t uid, gid_t gid, const char *path, struct stat *stbuf)
int	magma_statfs (uid_t uid, gid_t gid, const char *path, struct statfs *statbuf)
int	magma_mknod (uid_t uid, gid_t gid, const char *path, mode_t mode, dev_t rdev)
int	magma_unlink (uid_t uid, gid_t gid, const char *path)
int	magma_truncate (uid_t uid, gid_t gid, const char *path, off_t offset)
int	magma_utime (uid_t uid, gid_t gid, const char *path, time_t atime, time_t mtime)
int	magma_rename (uid_t uid, gid_t gid, const char *from, const char *to)
int	magma_chmod (uid_t uid, gid_t gid, const char *path, mode_t mode)
int	magma_chown (uid_t uid, gid_t gid, const char *path, uid_t newuid, gid_t newgid)
int	magma_open (uid_t uid, gid_t gid, const char *path, int flags)
int	magma_read (uid_t uid, gid_t gid, const char *path, size_t size, off_t offset, char *buf)
int	magma_write (uid_t uid, gid_t gid, const char *path, size_t size, off_t offset, char *buf)
int	magma_mkdir (uid_t uid, gid_t gid, const char *path, mode_t mode)
int	magma_rmdir (uid_t uid, gid_t gid, const char *path)
int	magma_readlink (uid_t uid, gid_t gid, const char *path, char *buf, size_t size)
int	magma_symlink (uid_t uid, gid_t gid, const char *from, const char *to)
void	magma_sync_cache ()
void	magma_flush_cache ()
magma_DIR_t *	magma_opendir (uid_t uid, gid_t gid, const char *path)
char *	magma_readdir (magma_DIR_t *dirp)
void	magma_seekdir (magma_DIR_t *dirp, off_t offset)
off_t	magma_telldir (magma_DIR_t *dirp)
void	magma_closedir (magma_DIR_t *dirp)
void	magma_cleanup (int s)
void	clean_shutdown ()
void	magma_network_loop (int single_thread)

---

Define Documentation

#define INCLUDE_FLARE_INTERNALS

 

#define reduce_file_descriptors

(

)

dbg(LOG_ERR, DEBUG_ERR, "Define a reduce_file_descriptor() function to manage FD starvation")

#define STACK_DEPTH   20

---

Function Documentation

void clean_shutdown

(

)

perform a clean server shutdown and exits main process

int magma_chmod	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		mode_t	mode
	)

chmod() equivalent. Changes mode to a flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	mode	new flare mode

Returns:

0 on success, -1 on error and sets errno

int magma_chown	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		uid_t	newuid,
		gid_t	newgid
	)

chown() equivalent. Changes ownership to a flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	newuid	new UID to be assigned to the flare
	newgid	new GID to be assigned to the flare

Returns:

0 on success, -1 on error and sets errno

void magma_cleanup

(

int

s

)

hook for signal()

Parameters:

s

signal received

void magma_closedir

(

magma_DIR_t *

dirp

)

close opened directory.

Parameters:

dirp

magma_DIR_t pointer of opened directory

void magma_flush_cache

(

)

write cache on disk and delete it from memory

int magma_getattr	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		struct stat *	stbuf
	)

magma flare system interface mimics as closer as possible libc function interface. every function listed below set errno on its exit.

each function gets a uid and gid to assign the operation to a used and to chek permission lstat() equivalent. Fills struct stat stbuf of informations relating to flare path.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	stbuf	struct stat result buffer

Returns:

0 on success, -1 on error and sets errno

int magma_mkdir	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		mode_t	mode
	)

mkdir() equivalent. Create a new directory flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the directory
	mode	directory permission

Returns:

0 on success, -1 on error and sets errno

int magma_mknod	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		mode_t	mode,
		dev_t	rdev
	)

mknod() equivalent. Create new regular, FIFO char and block dev flares. Returns an error if used to create a directory.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare to be created
	mode	permission and flare type (see mknod(2) for more info)
	rdev	major and minor number if flare is a char or block device

Returns:

0 on success, -1 on error and sets errno

void magma_network_loop

(

int

single_thread

)

This is the core of network event loop provided by magma. So far, it simply accept new connections and spawn a new thread to manage it. If single_thread is true, no new thread is created and network loop serve answers by pipelining them (only for debug purposes).

Parameters:

single_thread

if true, requests are managed in this thread

Todo:

Using a better threading mechanism will provide better performances. New incoming connections should be placed in a queue and serviced by pre started threads. When changing this, change also garbage collector.

int magma_open	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		int	flags
	)

open() equivalent.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	flags	describe the type of open (read, write, ...) (see open(2) for more informations)

Returns:

0 on success, -1 on error and sets errno

magma_DIR_t* magma_opendir	(	uid_t	uid,
		gid_t	gid,
		const char *	path
	)

open a magma directory returning a magma_DIR_t directory pointer. set offset to zero.

Parameters:

	uid	UID of user requesting opendir
	gid	GID of user requesting opendir
	path	the path to be opened

int magma_read	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		size_t	size,
		off_t	offset,
		char *	buf
	)

read() equivalent. Read some data from a regular flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	size	requested data length
	offset	requested data position inside the flare
	buf	memory region to store read data

Returns:

0 on success, -1 on error and sets errno

Todo:

Is present a test to ensure that flare is a regular one?

char* magma_readdir

(

magma_DIR_t *

dirp

)

return next entry in opened directory

Parameters:

dirp

a magma_DIR_t pointer

int magma_readlink	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		char *	buf,
		size_t	size
	)

readlink() equivalent. Read target of a link.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	buf	memory location to store link target
	size	dimension of buffer buf

Returns:

0 on success, -1 on error and sets errno

int magma_rename	(	uid_t	uid,
		gid_t	gid,
		const char *	from,
		const char *	to
	)

rename() equivalent. Change name to a flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	from	original flare path
	to	new flare path

Returns:

0 on success, -1 on error and sets errno

Todo:

So far magma uses a typical errno (EXDEV) which means cross link rename to refuse renaming a flare, since that can involve up to four magma nodes. Can be changed in the future...

int magma_rmdir	(	uid_t	uid,
		gid_t	gid,
		const char *	path
	)

rmdir() equivalent. Delete a directory flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested

Returns:

0 on success, -1 on error and sets errno

Todo:

Is there a test to ensure it's a directory flare?

void magma_seekdir	(	magma_DIR_t *	dirp,
		off_t	offset
	)

seek inside a directory (only if a local one)

Parameters:

	dirp	magma_DIR_t pointer of opened directory
	offset	new off_t offset

int magma_stat	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		struct stat *	stbuf
	)

stat() equivalent. Fills struct stat stbuf of informations relating to flare path.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	stbuf	struct stat result buffer

Returns:

0 on success, -1 on error and sets errno

int magma_statfs	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		struct statfs *	statbuf
	)

statfs() equivalent. Fills struct statfs statbuf of informations relating to share which holds flare path. Since magma preorganize shares and since flare protocol predeclare the share involved in current connection, passing a path is useless. But parameter has been mantained so far.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	statbuf	struct stat result buffer

Returns:

0 on success, -1 on error and sets errno

int magma_symlink	(	uid_t	uid,
		gid_t	gid,
		const char *	from,
		const char *	to
	)

symlink() equivalent. Create a symbolic link.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	from	path of the symbolic link
	to	target path of this link

Returns:

0 on success, -1 on error and sets errno

void magma_sync_cache

(

)

write cache on disk

off_t magma_telldir

(

magma_DIR_t *

dirp

)

return current offset in opened directory

Parameters:

dirp

magma_DIR_t pointer of opened directory

int magma_truncate	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		off_t	offset
	)

truncate() equivalent. Truncate a regular flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	offset	the truncation point

Returns:

0 on success, -1 on error and sets errno

Todo:

There is a check to ensure this flare is a regular one?

int magma_unlink	(	uid_t	uid,
		gid_t	gid,
		const char *	path
	)

unlink() equivalent. Delete a regular, FIFO, char or block dev flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare to be unlinked

Returns:

0 on success, -1 on error and sets errno

int magma_utime	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		time_t	atime,
		time_t	mtime
	)

utime() equivalent. Update access and modification time of a flare.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	atime	access time
	mtime	modification time

Returns:

0 on success, -1 on error and sets errno

int magma_write	(	uid_t	uid,
		gid_t	gid,
		const char *	path,
		size_t	size,
		off_t	offset,
		char *	buf
	)

write() equivalent. Write some data to a regular file. relating to flare path.

Parameters:

	uid	UID requesting the operation
	gid	GID requesting the operation
	path	path of the flare requested
	size	data length
	offset	data position inside the flare
	buf	memory region to store read data

Returns:

0 on success, -1 on error and sets errno

Todo:

Is present a test to ensure that flare is a regular one?

This file last modified Wednesday, 09-Jan-2008 20:02:47 CET

Magma is (c) 2006-2008 Tx0
Magma is free software released under GPL v.2 license