text: /*-
   * Copyright (c) 2006-2009 University of Zagreb
   * Copyright (c) 2006-2009 FreeBSD Foundation
   * All rights reserved.
   *
   * This software was developed by the University of Zagreb and the
   * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
   * FreeBSD Foundation.
   *
   * 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: src/sys/net/vnet.h,v 1.25.2.8.2.1 2010/12/21 17:09:25 kensmith Exp $
   */
  
  /*-
   * This header file defines several sets of interfaces supporting virtualized
   * network stacks:
   *
   * - Definition of 'struct vnet' and functions and macros to allocate/free/
   *   manipulate it.
   *
   * - 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_
  
  /*
   * struct vnet describes a virtualized network stack, and is primarily a
   * pointer to storage for virtualized global variables.  Expose to userspace
   * as required for libkvm.
   */
  #if defined(_KERNEL) || defined(_WANT_VNET)
  #include <sys/queue.h>
  
  struct vnet {
  	LIST_ENTRY(vnet)	 vnet_le;	/* all vnets list */
  	u_int			 vnet_magic_n;
  	u_int			 vnet_ifcnt;
  	u_int			 vnet_sockcnt;
  	void			*vnet_data_mem;
  	uintptr_t		 vnet_data_base;
  };
  #define	VNET_MAGIC_N	0x3e0d8f29
  
  /*
   * These two virtual network stack allocator definitions are also required
   * for libkvm so that it can evaluate virtualized global variables.
   */
  #define	VNET_SETNAME		"set_vnet"
  #define	VNET_SYMPREFIX		"vnet_entry_"
  #endif
  
  #ifdef _KERNEL
  
  #ifdef VIMAGE
  #include <sys/lock.h>
  #include <sys/proc.h>			/* for struct thread */
  #include <sys/rwlock.h>
  #include <sys/sx.h>
  
  /*
   * Location of the kernel's 'set_vnet' linker set.
   */
  extern uintptr_t	*__start_set_vnet;
  extern uintptr_t	*__stop_set_vnet;
  
  #define	VNET_START	(uintptr_t)&__start_set_vnet
  #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
  
  /*
   * Functions to allocate and destroy virtual network stacks.
   */
  struct vnet *vnet_alloc(void);
  void	vnet_destroy(struct vnet *vnet);
  
  /*
   * The current virtual network stack -- we may wish to move this to struct
   * pcpu in the future.
   */
  #define	curvnet	curthread->td_vnet
  
  /*
   * Various macros -- get and set the current network stack, but also
   * assertions.
   */
  #ifdef VNET_DEBUG
  void vnet_log_recursion(struct vnet *, const char *, int);
  
  #define	VNET_ASSERT(condition)						\
  	if (!(condition)) {						\
  		printf("VNET_ASSERT @ %s:%d %s():\n",			\
  			__FILE__, __LINE__, __FUNCTION__);		\
  		panic(#condition);					\
  	}
  
  #define	CURVNET_SET_QUIET(arg)						\
  	VNET_ASSERT((arg)->vnet_magic_n == VNET_MAGIC_N);		\
  	struct vnet *saved_vnet = curvnet;				\
  	const char *saved_vnet_lpush = curthread->td_vnet_lpush;	\
  	curvnet = arg;							\
  	curthread->td_vnet_lpush = __FUNCTION__;
   
  #define	CURVNET_SET_VERBOSE(arg)					\
  	CURVNET_SET_QUIET(arg)						\
  	if (saved_vnet)							\
  		vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
  
  #define	CURVNET_SET(arg)	CURVNET_SET_VERBOSE(arg)
   
  #define	CURVNET_RESTORE()						\
  	VNET_ASSERT(saved_vnet == NULL ||				\
  		    saved_vnet->vnet_magic_n == VNET_MAGIC_N);		\
  	curvnet = saved_vnet;						\
  	curthread->td_vnet_lpush = saved_vnet_lpush;
  #else /* !VNET_DEBUG */
  #define	VNET_ASSERT(condition)
  
  #define	CURVNET_SET(arg)						\
  	struct vnet *saved_vnet = curvnet;				\
  	curvnet = arg;	
   
  #define	CURVNET_SET_VERBOSE(arg)	CURVNET_SET(arg)
  #define	CURVNET_SET_QUIET(arg)		CURVNET_SET(arg)
   
  #define	CURVNET_RESTORE()						\
  	curvnet = saved_vnet;
  #endif /* VNET_DEBUG */
  
  extern struct vnet *vnet0;
  #define	IS_DEFAULT_VNET(arg)	((arg) == vnet0)
  
  #define	CRED_TO_VNET(cr)	(cr)->cr_prison->pr_vnet
  #define	TD_TO_VNET(td)		CRED_TO_VNET((td)->td_ucred)
  #define	P_TO_VNET(p)		CRED_TO_VNET((p)->p_ucred)
  
  /*
   * Global linked list of all virtual network stacks, along with read locks to
   * access it.  If a caller may sleep while accessing the list, it must use
   * the sleepable lock macros.
   */
  LIST_HEAD(vnet_list_head, vnet);
  extern struct vnet_list_head vnet_head;
  extern struct rwlock vnet_rwlock;
  extern struct sx vnet_sxlock;
  
  #define	VNET_LIST_RLOCK()		sx_slock(&vnet_sxlock)
  #define	VNET_LIST_RLOCK_NOSLEEP()	rw_rlock(&vnet_rwlock)
  #define	VNET_LIST_RUNLOCK()		sx_sunlock(&vnet_sxlock)
  #define	VNET_LIST_RUNLOCK_NOSLEEP()	rw_runlock(&vnet_rwlock)
  
  /*
   * Iteration macros to walk the global list of virtual network stacks.
   */
  #define	VNET_ITERATOR_DECL(arg)	struct vnet *arg
  #define	VNET_FOREACH(arg)	LIST_FOREACH((arg), &vnet_head, vnet_le)
  
  /*
   * Virtual network stack memory allocator, which allows global variables to
   * be automatically instantiated for each network stack instance.
   */
  __asm__(
  #if defined(__arm__)
  	".section " VNET_SETNAME ", \"aw\", %progbits\n"
  #else
  	".section " VNET_SETNAME ", \"aw\", @progbits\n"
  #endif
  	"\t.p2align " __XSTRING(CACHE_LINE_SHIFT) "\n"
  	"\t.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);
  
  /*
   * 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|CTLFLAG_VNET|(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, CTLFLAG_VNET|(access), ptr, arg, 	\
  	    handler, fmt, descr)
  #define	SYSCTL_VNET_OPAQUE(parent, nbr, name, access, ptr, len, fmt,    \
  	    descr)							\
  	SYSCTL_OID(parent, nbr, name,					\
  	    CTLTYPE_OPAQUE|CTLFLAG_VNET|(access), ptr, len, 		\
  	    vnet_sysctl_handle_opaque, fmt, descr)
  #define	SYSCTL_VNET_STRING(parent, nbr, name, access, arg, len, descr)	\
  	SYSCTL_OID(parent, nbr, name,					\
  	    CTLTYPE_STRING|CTLFLAG_VNET|(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|CTLFLAG_VNET|(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|CTLFLAG_VNET|(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);
  
  /*
   * EVENTHANDLER(9) extensions.
   */
  #include <sys/eventhandler.h>
  
  void	vnet_global_eventhandler_iterator_func(void *, ...);
  #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
  do {									\
  	if (IS_DEFAULT_VNET(curvnet)) {					\
  		(tag) = vimage_eventhandler_register(NULL, #name, func,	\
  		    arg, priority,					\
  		    vnet_global_eventhandler_iterator_func);		\
  	}								\
  } while(0)
  #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
  do {									\
  	if (IS_DEFAULT_VNET(curvnet)) {					\
  		vimage_eventhandler_register(NULL, #name, func,		\
  		    arg, priority,					\
  		    vnet_global_eventhandler_iterator_func);		\
  	}								\
  } while(0)
  
  #else /* !VIMAGE */
  
  /*
   * Various virtual network stack macros compile to no-ops without VIMAGE.
   */
  #define	curvnet			NULL
  
  #define	VNET_ASSERT(condition)
  #define	CURVNET_SET(arg)
  #define	CURVNET_SET_QUIET(arg)
  #define	CURVNET_RESTORE()
  
  #define	VNET_LIST_RLOCK()
  #define	VNET_LIST_RLOCK_NOSLEEP()
  #define	VNET_LIST_RUNLOCK()
  #define	VNET_LIST_RUNLOCK_NOSLEEP()
  #define	VNET_ITERATOR_DECL(arg)
  #define	VNET_FOREACH(arg)
  
  #define	IS_DEFAULT_VNET(arg)	1
  #define	CRED_TO_VNET(cr)	NULL
  #define	TD_TO_VNET(td)		NULL
  #define	P_TO_VNET(p)		NULL
  
  /*
   * 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_OPAQUE(parent, nbr, name, access, ptr, len, fmt,    \
  	    descr)							\
  	SYSCTL_OPAQUE(parent, nbr, name, access, ptr, len, 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)
  
  /*
   * Without VIMAGE revert to the default implementation.
   */
  #define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
  	(tag) = eventhandler_register(NULL, #name, func, arg, priority)
  #define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority)	\
  	eventhandler_register(NULL, #name, func, arg, priority)
  #endif /* VIMAGE */
  #endif /* _KERNEL */
  
  #endif /* !_NET_VNET_H_ */
  