Syscall wrappers


Functions
int	vc_syscall (uint32_t cmd, xid_t xid, void *data)
	The generic vserver syscall This function executes the generic vserver syscall. It uses the correct syscallnumber (which may differ between the different architectures).
int	vc_get_version ()
	Returns the version of the current kernel API.
vc_vci_t	vc_get_vci ()
	Returns the kernel configuration bits.
xid_t	vc_new_s_context (xid_t ctx, unsigned int remove_cap, unsigned int flags)
	Moves current process into a context Puts current process into context ctx, removes the capabilities given in remove_cap and sets flags.
int	vc_set_ipv4root (uint32_t bcast, size_t nb, struct vc_ip_mask_pair const *ips)
	Sets the ipv4root information.
xid_t	vc_ctx_create (xid_t xid, struct vc_ctx_flags *flags)
	Creates a context without starting it. This functions initializes a new context. When already in a freshly created context, this old context will be discarded.
int	vc_ctx_migrate (xid_t xid, uint_least64_t flags)
	Moves the current process into the specified context.
int	vc_ctx_stat (xid_t xid, struct vc_ctx_stat *stat)
	Get some statistics about a context.
int	vc_virt_stat (xid_t xid, struct vc_virt_stat *stat)
	Get more statistics about a context.
int	vc_ctx_kill (xid_t ctx, pid_t pid, int sig)
	Sends a signal to a context/pid Special values for pid are: -1 which means every process in ctx except the init-process 0 which means every process in ctx inclusive the init-process.
xid_t	vc_get_task_xid (pid_t pid)
	Returns the context of the given process.
int	vc_wait_exit (xid_t xid)
	Waits for the end of a context.
int	vc_get_rlimit (xid_t xid, int resource, struct vc_rlimit *lim)
	Returns the limits of resource.
int	vc_set_rlimit (xid_t xid, int resource, struct vc_rlimit const *lim)
	Sets the limits of resource.
int	vc_rlimit_stat (xid_t xid, int resource, struct vc_rlimit_stat *stat)
	Returns the current stats of resource.
int	vc_reset_minmax (xid_t xid)
	Resets the minimum and maximum observed values of all resources.
int	vc_get_iattr (char const filename, xid_t xid, uint_least32_t flags, uint_least32_t mask)
	Returns information about attributes and assigned context of a file. This function returns the VC_IATTR_XXX flags and about the assigned context of a file. To request an information, the appropriate bit in `mask` must be set and the corresponding parameter (xid or flags) must not be NULL.
xid_t	vc_getfilecontext (char const *filename)
	Returns the context of `filename` This function calls vc_get_iattr() with appropriate arguments to determine the context of `filename`. In error-case or when no context is assigned, `VC_NOCTX` will be returned. To differ between both cases, `errno` must be examined.

Detailed Description

Functions which are calling the vserver syscall directly.

Function Documentation

xid_t vc_ctx_create	(	xid_t	xid,
		struct vc_ctx_flags *	flags
	)

Creates a context without starting it.

This functions initializes a new context. When already in a freshly created context, this old context will be discarded.

Parameters:

xid

The new context; special values are:

VC_DYNAMIC_XID which means to create a dynamic context

Returns:: the xid of the created context, or VC_NOCTX on errors. errno will be set appropriately.

int vc_ctx_migrate	(	xid_t	xid,
		uint_least64_t	flags
	)

Moves the current process into the specified context.

Parameters:

	xid	The new context
	flags	The flags, see VC_VXM_*

Returns:: 0 on success, -1 on errors

int vc_ctx_stat	(	xid_t	xid,
		struct vc_ctx_stat *	stat
	)

Get some statistics about a context.

Parameters:

	xid	The context to get stats about
	stat	Where to store the result

Returns:: 0 on success, -1 on errors.

int vc_get_iattr	(	char const *	filename,
		xid_t *	xid,
		uint_least32_t *	flags,
		uint_least32_t *	mask
	)

Returns information about attributes and assigned context of a file.

This function returns the VC_IATTR_XXX flags and about the assigned context of a file. To request an information, the appropriate bit in mask must be set and the corresponding parameter (xid or flags) must not be NULL.

E.g. to receive the assigned context, the VC_IATTR_XID bit must be set in mask, and xid must point to valid memory.

Possible flags are VC_IATTR_ADMIN, VC_IATTR_WATCH , VC_IATTR_HIDE, VC_IATTR_BARRIER, VC_IATTR_IUNLINK and VC_IATTR_IMMUTABLE.

Parameters:

	filename	The name of the file whose attributes shall be determined.
	xid	When non-zero and the VC_IATTR_XID bit is set in mask, the assigned context of filename will be stored there.
	flags	When non-zero, a bitmask of current attributes will be stored there. These attributes must be requested explicitly by setting the appropriate bit in mask
	mask	Points to a bitmask which tells which attributes shall be determined. On return, it will masquerade the attributes which were determined.

Precondition:: mask!=0 && !((*mask&VC_IATTR_XID) && xid==0) && !((*mask&~VC_IATTR_XID) && flags==0)

int vc_get_rlimit	(	xid_t	xid,
		int	resource,
		struct vc_rlimit *	lim
	)

Returns the limits of resource.

Parameters:

	xid	The id of the context
	resource	The resource which will be queried
	lim	The result which will be filled with the limits

Returns:: 0 on success, and -1 on errors.

xid_t vc_get_task_xid ( pid_t pid )

Returns the context of the given process.

Parameters:

pid

the process-id whose xid shall be determined; pid==0 means the current process.

Returns:: the xid of process pid or -1 on errors

vc_vci_t vc_get_vci ( )

Returns the kernel configuration bits.

Returns:: The kernel configuration bits

int vc_get_version ( )

Returns the version of the current kernel API.

Returns:: The versionnumber of the kernel API

xid_t vc_getfilecontext ( char const * filename )

Returns the context of filename

This function calls vc_get_iattr() with appropriate arguments to determine the context of filename. In error-case or when no context is assigned, VC_NOCTX will be returned. To differ between both cases, errno must be examined.

WARNING: this function can modify errno although no error happened.

Parameters:

filename

The file to check

Returns:: The assigned context, or VC_NOCTX when an error occured or no such assignment exists. errno will be 0 in the latter case

xid_t vc_new_s_context	(	xid_t	ctx,
		unsigned int	remove_cap,
		unsigned int	flags
	)

Moves current process into a context

Puts current process into context ctx, removes the capabilities given in remove_cap and sets flags.

Parameters:

	ctx	The new context; special values for are VC_SAMECTX which means the current context (just for changing caps and flags) VC_DYNAMIC_XID which means the next free context; this value can be used by ordinary users also
	remove_cap	The linux capabilities which will be removed.
	flags	Special flags which will be set.

Returns:: The new context-id, or VC_NOCTX on errors; errno will be set appropriately

See http://vserver.13thfloor.at/Stuff/Logic.txt for details

int vc_reset_minmax ( xid_t xid )

Resets the minimum and maximum observed values of all resources.

Parameters:

xid

The id of the context

Returns:: 0 on success, and -1 on errors.

int vc_rlimit_stat	(	xid_t	xid,
		int	resource,
		struct vc_rlimit_stat *	stat
	)

Returns the current stats of resource.

Parameters:

	xid	The id of the context
	resource	The resource which will be queried
	stat	The result which will be filled with the stats

Returns:: 0 on success, and -1 on errors.

int vc_set_ipv4root	(	uint32_t	bcast,
		size_t	nb,
		struct vc_ip_mask_pair const *	ips
	)

Sets the ipv4root information.

Precondition:: nb < NB_IPV4ROOT && ips != 0

int vc_set_rlimit	(	xid_t	xid,
		int	resource,
		struct vc_rlimit const *	lim
	)

Sets the limits of resource.

Parameters:

	xid	The id of the context
	resource	The resource which will be queried
	lim	The new limits

Returns:: 0 on success, and -1 on errors.

int vc_syscall	(	uint32_t	cmd,
		xid_t	xid,
		void *	data
	)

The generic vserver syscall

This function executes the generic vserver syscall. It uses the correct syscallnumber (which may differ between the different architectures).

Parameters:

	cmd	the command to be executed
	xid	the xid on which the cmd shall be applied
	data	additional arguments; depends on `cmd`

Returns:: depends on cmd; usually, -1 stands for an error

int vc_virt_stat	(	xid_t	xid,
		struct vc_virt_stat *	stat
	)

Get more statistics about a context.

Parameters:

	xid	The context to get stats about
	stat	Where to store the result

Returns:: 0 on success, -1 on errors.