freebsd-skq/sys/net/vnet.h

/*-
 * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
 * Copyright (c) 2009 Robert N. M. Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

/*-
 * This header file defines several sets of interfaces supporting virtualized
 * network stacks:
 *
 * - A virtual network stack memory allocator, which provides support for
 *   virtualized global variables via a special linker set, set_vnet.
 *
 * - Virtualized sysinits/sysuninits, which allow constructors and
 *   destructors to be run for each network stack subsystem as virtual
 *   instances are created and destroyed.
 *
 * If VIMAGE isn't compiled into the kernel, virtualized global variables
 * compile to normal global variables, and virtualized sysinits to regular
 * sysinits.
 */

#ifndef _NET_VNET_H_
#define	_NET_VNET_H_

/*
 * Virtual network stack memory allocator, which allows global variables to
 * be automatically instantiated for each network stack instance.
 */
#if defined(_KERNEL) || defined(_WANT_VNET)
#define	VNET_SETNAME		"set_vnet"
#define	VNET_SYMPREFIX		"vnet_entry_"
#endif

#ifdef _KERNEL
#ifdef VIMAGE

#if defined(__arm__)
__asm__(".section " VNET_SETNAME ", \"aw\", %progbits");
#else
__asm__(".section " VNET_SETNAME ", \"aw\", @progbits");
#endif
__asm__(".previous");

#define	VNET_NAME(n)		vnet_entry_##n
#define	VNET_DECLARE(t, n)	extern t VNET_NAME(n)
#define	VNET_DEFINE(t, n)	t VNET_NAME(n) __section(VNET_SETNAME) __used
#define	_VNET_PTR(b, n)		(__typeof(VNET_NAME(n))*)		\
				    ((b) + (uintptr_t)&VNET_NAME(n))

#define	_VNET(b, n)		(*_VNET_PTR(b, n))

/*
 * Virtualized global variable accessor macros.
 */
#define	VNET_VNET_PTR(vnet, n)		_VNET_PTR((vnet)->vnet_data_base, n)
#define	VNET_VNET(vnet, n)		(*VNET_VNET_PTR((vnet), n))

#define	VNET_PTR(n)		VNET_VNET_PTR(curvnet, n)
#define	VNET(n)			VNET_VNET(curvnet, n)

/*
 * Virtual network stack allocator interfaces from the kernel linker.
 */
void	*vnet_data_alloc(int size);
void	 vnet_data_copy(void *start, int size);
void	 vnet_data_free(void *start_arg, int size);

/*
 * Virtual network stack allocator interfaces for vnet setup/teardown.
 */
struct vnet;
void	 vnet_data_init(struct vnet *vnet);
void	 vnet_data_destroy(struct vnet *vnet);

/*
 * Sysctl variants for vnet-virtualized global variables.  Include
 * <sys/sysctl.h> to expose these definitions.
 *
 * Note: SYSCTL_PROC() handler functions will need to resolve pointer
 * arguments themselves, if required.
 */
#ifdef SYSCTL_OID
int	vnet_sysctl_handle_int(SYSCTL_HANDLER_ARGS);
int	vnet_sysctl_handle_opaque(SYSCTL_HANDLER_ARGS);
int	vnet_sysctl_handle_string(SYSCTL_HANDLER_ARGS);
int	vnet_sysctl_handle_uint(SYSCTL_HANDLER_ARGS);

#define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
	SYSCTL_OID(parent, nbr, name, CTLTYPE_INT|CTLFLAG_MPSAFE|(access), \
	    ptr, val, vnet_sysctl_handle_int, "I", descr)
#define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
	    fmt, descr)							\
	SYSCTL_OID(parent, nbr, name, access, ptr, arg, handler, fmt,	\
	    descr)
#define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
	SYSCTL_OID(parent, nbr, name, CTLTYPE_STRING|(access), arg,	\
	    len, vnet_sysctl_handle_string, "A", descr)
#define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
	SYSCTL_OID(parent, nbr, name, CTLTYPE_OPAQUE|(access), ptr,	\
	    sizeof(struct type), vnet_sysctl_handle_opaque, "S," #type,	\
	    descr)
#define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
	SYSCTL_OID(parent, nbr, name, CTLTYPE_UINT|CTLFLAG_MPSAFE|(access), \
	    ptr, val, vnet_sysctl_handle_uint, "IU", descr)
#define	VNET_SYSCTL_ARG(req, arg1) do {					\
	if (arg1 != NULL)						\
		arg1 = (void *)(TD_TO_VNET((req)->td)->vnet_data_base +	\
		    (uintptr_t)(arg1));					\
} while (0)
#endif /* SYSCTL_OID */

/*
 * Virtual sysinit mechanism, allowing network stack components to declare
 * startup and shutdown methods to be run when virtual network stack
 * instances are created and destroyed.
 */
#include <sys/kernel.h>

/*
 * SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
 * destructors.
 */
struct vnet_sysinit {
	enum sysinit_sub_id	subsystem;
	enum sysinit_elem_order	order;
	sysinit_cfunc_t		func;
	const void		*arg;
	TAILQ_ENTRY(vnet_sysinit) link;
};

#define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
	static struct vnet_sysinit ident ## _vnet_init = {		\
		subsystem,						\
		order,							\
		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
		(arg)							\
	};								\
	SYSINIT(vnet_init_ ## ident, subsystem, order,			\
	    vnet_register_sysinit, &ident ## _vnet_init);		\
	SYSUNINIT(vnet_init_ ## ident, subsystem, order,		\
	    vnet_deregister_sysinit, &ident ## _vnet_init)

#define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
	static struct vnet_sysinit ident ## _vnet_uninit = {		\
		subsystem,						\
		order,							\
		(sysinit_cfunc_t)(sysinit_nfunc_t)func,			\
		(arg)							\
	};								\
	SYSINIT(vnet_uninit_ ## ident, subsystem, order,		\
	    vnet_register_sysuninit, &ident ## _vnet_uninit);		\
	SYSUNINIT(vnet_uninit_ ## ident, subsystem, order,		\
	    vnet_deregister_sysuninit, &ident ## _vnet_uninit)

/*
 * Run per-vnet sysinits or sysuninits during vnet creation/destruction.
 */
void	 vnet_sysinit(void);
void	 vnet_sysuninit(void);

/*
 * Interfaces for managing per-vnet constructors and destructors.
 */
void	vnet_register_sysinit(void *arg);
void	vnet_register_sysuninit(void *arg);
void	vnet_deregister_sysinit(void *arg);
void	vnet_deregister_sysuninit(void *arg);

#else /* !VIMAGE */

/*
 * Versions of the VNET macros that compile to normal global variables and
 * standard sysctl definitions.
 */
#define	VNET_NAME(n)		n
#define	VNET_DECLARE(t, n)	extern t n
#define	VNET_DEFINE(t, n)	t n
#define	_VNET_PTR(b, n)		&VNET_NAME(n)

/*
 * Virtualized global variable accessor macros.
 */
#define	VNET_VNET_PTR(vnet, n)		(&(n))
#define	VNET_VNET(vnet, n)		(n)

#define	VNET_PTR(n)		(&(n))
#define	VNET(n)			(n)

/*
 * When VIMAGE isn't compiled into the kernel, virtaulized SYSCTLs simply
 * become normal SYSCTLs.
 */
#ifdef SYSCTL_OID
#define	SYSCTL_VNET_INT(parent, nbr, name, access, ptr, val, descr)	\
	SYSCTL_INT(parent, nbr, name, access, ptr, val, descr)
#define	SYSCTL_VNET_PROC(parent, nbr, name, access, ptr, arg, handler,	\
	    fmt, descr)							\
	SYSCTL_PROC(parent, nbr, name, access, ptr, arg, handler, fmt,	\
	    descr)
#define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
	SYSCTL_STRING(parent, nbr, name, access, arg, len, descr)
#define	SYSCTL_VNET_STRUCT(parent, nbr, name, access, ptr, type, descr)	\
	SYSCTL_STRUCT(parent, nbr, name, access, ptr, type, descr)
#define	SYSCTL_VNET_UINT(parent, nbr, name, access, ptr, val, descr)	\
	SYSCTL_UINT(parent, nbr, name, access, ptr, val, descr)
#define	VNET_SYSCTL_ARG(req, arg1)
#endif /* SYSCTL_OID */

/*
 * When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
 * map into normal sysinits, which have the same ordering properties.
 */
#define	VNET_SYSINIT(ident, subsystem, order, func, arg)		\
	SYSINIT(ident, subsystem, order, func, arg)
#define	VNET_SYSUNINIT(ident, subsystem, order, func, arg)		\
	SYSUNINIT(ident, subsystem, order, func, arg)

#endif /* VIMAGE */
#endif /* _KERNEL */

#endif /* !_NET_VNET_H_ */