/*
 * netgraph.h
 */

/*-
 * Copyright (c) 1996-1999 Whistle Communications, Inc.
 * All rights reserved.
 * 
 * Subject to the following obligations and disclaimer of warranty, use and
 * redistribution of this software, in source or object code forms, with or
 * without modifications are expressly permitted by Whistle Communications;
 * provided, however, that:
 * 1. Any and all reproductions of the source or object code must include the
 *    copyright notice above and the following disclaimer of warranties; and
 * 2. No rights are granted, in any manner or form, to use Whistle
 *    Communications, Inc. trademarks, including the mark "WHISTLE
 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
 *    such appears in the above copyright notice or in the software.
 * 
 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * Author: Julian Elischer <julian@freebsd.org>
 * $Whistle: netgraph.h,v 1.29 1999/11/01 07:56:13 julian Exp $
 */

#ifndef _NETGRAPH_NETGRAPH_H_
#define _NETGRAPH_NETGRAPH_H_

#ifndef _KERNEL
#error "This file should not be included in user level programs"
#endif

#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/refcount.h>

#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_netgraph.h"
#include "opt_kdb.h"
#endif

/* debugging options */
#define NG_SEPARATE_MALLOC      /* make modules use their own malloc types */

/*
 * This defines the in-kernel binary interface version.
 * It is possible to change this but leave the external message
 * API the same. Each type also has it's own cookies for versioning as well.
 * Change it for NETGRAPH_DEBUG version so we cannot mix debug and non debug
 * modules.
 */
#define _NG_ABI_VERSION 12

#ifdef  NETGRAPH_DEBUG
#define _NG_ABI_PREFIX1 0x10000
#else
#define _NG_ABI_PREFIX1 0
#endif

#ifdef  INVARIANTS
#define _NG_ABI_PREFIX2 0x20000
#else
#define _NG_ABI_PREFIX2 0
#endif

#define NG_ABI_VERSION  (_NG_ABI_PREFIX1 + _NG_ABI_PREFIX2 + _NG_ABI_VERSION)

/*
 * Forward references for the basic structures so we can
 * define the typedefs and use them in the structures themselves.
 */
struct ng_hook ;
struct ng_node ;
struct ng_item ;
typedef struct ng_item *item_p;
typedef struct ng_node *node_p;
typedef struct ng_hook *hook_p;
typedef struct ng_item const *item_cp;
typedef struct ng_hook const *hook_cp;
#ifdef  NETGRAPH_DEBUG
typedef struct ng_node       *node_cp; /* annotated during debug */
#else   /* NETGRAPH_DEBUG */
typedef struct ng_node const *node_cp;
#endif  /* NETGRAPH_DEBUG */

/* node method definitions */
typedef int     ng_constructor_t(node_p node);
typedef int     ng_close_t(node_p node);
typedef int     ng_shutdown_t(node_p node);
typedef int     ng_newhook_t(node_p node, hook_p hook, const char *name);
typedef hook_p  ng_findhook_t(node_p node, const char *name);
typedef int     ng_connect_t(hook_p hook);
typedef int     ng_rcvmsg_t(node_p node, item_p item, hook_p lasthook);
typedef int     ng_rcvdata_t(hook_p hook, item_p item);
typedef int     ng_disconnect_t(hook_p hook);
typedef int     ng_rcvitem (node_p node, hook_p hook, item_p item);

/***********************************************************************
 ***************** Hook Structure and Methods **************************
 ***********************************************************************
 *
 * Structure of a hook
 */
struct ng_hook {
        char    hk_name[NG_HOOKSIZ];    /* what this node knows this link as */
        void   *hk_private;             /* node dependent ID for this hook */
        int     hk_flags;               /* info about this hook/link */
        int     hk_type;                /* tbd: hook data link type */
        struct  ng_hook *hk_peer;       /* the other end of this link */
        struct  ng_node *hk_node;       /* The node this hook is attached to */
        LIST_ENTRY(ng_hook) hk_hooks;   /* linked list of all hooks on node */
        ng_rcvmsg_t     *hk_rcvmsg;     /* control messages come here */
        ng_rcvdata_t    *hk_rcvdata;    /* data comes here */
        int     hk_refs;                /* dont actually free this till 0 */
#ifdef  NETGRAPH_DEBUG /*----------------------------------------------*/
#define HK_MAGIC 0x78573011
        int     hk_magic;
        char    *lastfile;
        int     lastline;
        SLIST_ENTRY(ng_hook)      hk_all;               /* all existing items */
#endif  /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
};
/* Flags for a hook */
#define HK_INVALID              0x0001  /* don't trust it! */
#define HK_QUEUE                0x0002  /* queue for later delivery */
#define HK_FORCE_WRITER         0x0004  /* Incoming data queued as a writer */
#define HK_DEAD                 0x0008  /* This is the dead hook.. don't free */
#define HK_HI_STACK             0x0010  /* Hook has hi stack usage */
#define HK_TO_INBOUND           0x0020  /* Hook on ntw. stack inbound path. */

/*
 * Public Methods for hook
 * If you can't do it with these you probably shouldn;t be doing it.
 */
void ng_unref_hook(hook_p hook); /* don't move this */
#define _NG_HOOK_REF(hook)      refcount_acquire(&(hook)->hk_refs)
#define _NG_HOOK_NAME(hook)     ((hook)->hk_name)
#define _NG_HOOK_UNREF(hook)    ng_unref_hook(hook)
#define _NG_HOOK_SET_PRIVATE(hook, val) do {(hook)->hk_private = val;} while (0)
#define _NG_HOOK_SET_RCVMSG(hook, val)  do {(hook)->hk_rcvmsg = val;} while (0)
#define _NG_HOOK_SET_RCVDATA(hook, val) do {(hook)->hk_rcvdata = val;} while (0)
#define _NG_HOOK_PRIVATE(hook)  ((hook)->hk_private)
#define _NG_HOOK_NOT_VALID(hook)        ((hook)->hk_flags & HK_INVALID)
#define _NG_HOOK_IS_VALID(hook) (!((hook)->hk_flags & HK_INVALID))
#define _NG_HOOK_NODE(hook)     ((hook)->hk_node) /* only rvalue! */
#define _NG_HOOK_PEER(hook)     ((hook)->hk_peer) /* only rvalue! */
#define _NG_HOOK_FORCE_WRITER(hook)                             \
                do { hook->hk_flags |= HK_FORCE_WRITER; } while (0)
#define _NG_HOOK_FORCE_QUEUE(hook) do { hook->hk_flags |= HK_QUEUE; } while (0)
#define _NG_HOOK_SET_TO_INBOUND(hook)                           \
                do { hook->hk_flags |= HK_TO_INBOUND; } while (0)
#define _NG_HOOK_HI_STACK(hook) do { hook->hk_flags |= HK_HI_STACK; } while (0)

/* Some shortcuts */
#define NG_PEER_NODE(hook)      NG_HOOK_NODE(NG_HOOK_PEER(hook))
#define NG_PEER_HOOK_NAME(hook) NG_HOOK_NAME(NG_HOOK_PEER(hook))
#define NG_PEER_NODE_NAME(hook) NG_NODE_NAME(NG_PEER_NODE(hook))

#ifdef  NETGRAPH_DEBUG /*----------------------------------------------*/
#define _NN_ __FILE__,__LINE__
void    dumphook (hook_p hook, char *file, int line);
static __inline void    _chkhook(hook_p hook, char *file, int line);
static __inline void    _ng_hook_ref(hook_p hook, char * file, int line);
static __inline char *  _ng_hook_name(hook_p hook, char * file, int line);
static __inline void    _ng_hook_unref(hook_p hook, char * file, int line);
static __inline void    _ng_hook_set_private(hook_p hook,
                                void * val, char * file, int line);
static __inline void    _ng_hook_set_rcvmsg(hook_p hook,
                                ng_rcvmsg_t *val, char * file, int line);
static __inline void    _ng_hook_set_rcvdata(hook_p hook,
                                ng_rcvdata_t *val, char * file, int line);
static __inline void *  _ng_hook_private(hook_p hook, char * file, int line);
static __inline int     _ng_hook_not_valid(hook_p hook, char * file, int line);
static __inline int     _ng_hook_is_valid(hook_p hook, char * file, int line);
static __inline node_p  _ng_hook_node(hook_p hook, char * file, int line);
static __inline hook_p  _ng_hook_peer(hook_p hook, char * file, int line);
static __inline void    _ng_hook_force_writer(hook_p hook, char * file,
                                int line);
static __inline void    _ng_hook_force_queue(hook_p hook, char * file,
                                int line);
static __inline void    _ng_hook_set_to_inbound(hook_p hook, char * file,
                                int line);

static __inline void
_chkhook(hook_p hook, char *file, int line)
{
        if (hook->hk_magic != HK_MAGIC) {
                printf("Accessing freed ");
                dumphook(hook, file, line);
        }
        hook->lastline = line;
        hook->lastfile = file;
}

static __inline void
_ng_hook_ref(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_REF(hook);
}

static __inline char *
_ng_hook_name(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        return (_NG_HOOK_NAME(hook));
}

static __inline void
_ng_hook_unref(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_UNREF(hook);
}

static __inline void
_ng_hook_set_private(hook_p hook, void *val, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_SET_PRIVATE(hook, val);
}

static __inline void
_ng_hook_set_rcvmsg(hook_p hook, ng_rcvmsg_t *val, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_SET_RCVMSG(hook, val);
}

static __inline void
_ng_hook_set_rcvdata(hook_p hook, ng_rcvdata_t *val, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_SET_RCVDATA(hook, val);
}

static __inline void *
_ng_hook_private(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        return (_NG_HOOK_PRIVATE(hook));
}

static __inline int
_ng_hook_not_valid(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        return (_NG_HOOK_NOT_VALID(hook));
}

static __inline int
_ng_hook_is_valid(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        return (_NG_HOOK_IS_VALID(hook));
}

static __inline node_p
_ng_hook_node(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        return (_NG_HOOK_NODE(hook));
}

static __inline hook_p
_ng_hook_peer(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        return (_NG_HOOK_PEER(hook));
}

static __inline void
_ng_hook_force_writer(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_FORCE_WRITER(hook);
}

static __inline void
_ng_hook_force_queue(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_FORCE_QUEUE(hook);
}

static __inline void
_ng_hook_set_to_inbound(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_SET_TO_INBOUND(hook);
}

static __inline void
_ng_hook_hi_stack(hook_p hook, char * file, int line)
{
        _chkhook(hook, file, line);
        _NG_HOOK_HI_STACK(hook);
}

#define NG_HOOK_REF(hook)               _ng_hook_ref(hook, _NN_)
#define NG_HOOK_NAME(hook)              _ng_hook_name(hook, _NN_)
#define NG_HOOK_UNREF(hook)             _ng_hook_unref(hook, _NN_)
#define NG_HOOK_SET_PRIVATE(hook, val)  _ng_hook_set_private(hook, val, _NN_)
#define NG_HOOK_SET_RCVMSG(hook, val)   _ng_hook_set_rcvmsg(hook, val, _NN_)
#define NG_HOOK_SET_RCVDATA(hook, val)  _ng_hook_set_rcvdata(hook, val, _NN_)
#define NG_HOOK_PRIVATE(hook)           _ng_hook_private(hook, _NN_)
#define NG_HOOK_NOT_VALID(hook)         _ng_hook_not_valid(hook, _NN_)
#define NG_HOOK_IS_VALID(hook)          _ng_hook_is_valid(hook, _NN_)
#define NG_HOOK_NODE(hook)              _ng_hook_node(hook, _NN_)
#define NG_HOOK_PEER(hook)              _ng_hook_peer(hook, _NN_)
#define NG_HOOK_FORCE_WRITER(hook)      _ng_hook_force_writer(hook, _NN_)
#define NG_HOOK_FORCE_QUEUE(hook)       _ng_hook_force_queue(hook, _NN_)
#define NG_HOOK_SET_TO_INBOUND(hook)    _ng_hook_set_to_inbound(hook, _NN_)
#define NG_HOOK_HI_STACK(hook)          _ng_hook_hi_stack(hook, _NN_)

#else   /* NETGRAPH_DEBUG */ /*----------------------------------------------*/

#define NG_HOOK_REF(hook)               _NG_HOOK_REF(hook)
#define NG_HOOK_NAME(hook)              _NG_HOOK_NAME(hook)
#define NG_HOOK_UNREF(hook)             _NG_HOOK_UNREF(hook)
#define NG_HOOK_SET_PRIVATE(hook, val)  _NG_HOOK_SET_PRIVATE(hook, val)
#define NG_HOOK_SET_RCVMSG(hook, val)   _NG_HOOK_SET_RCVMSG(hook, val)
#define NG_HOOK_SET_RCVDATA(hook, val)  _NG_HOOK_SET_RCVDATA(hook, val)
#define NG_HOOK_PRIVATE(hook)           _NG_HOOK_PRIVATE(hook)
#define NG_HOOK_NOT_VALID(hook)         _NG_HOOK_NOT_VALID(hook)
#define NG_HOOK_IS_VALID(hook)          _NG_HOOK_IS_VALID(hook)
#define NG_HOOK_NODE(hook)              _NG_HOOK_NODE(hook)
#define NG_HOOK_PEER(hook)              _NG_HOOK_PEER(hook)
#define NG_HOOK_FORCE_WRITER(hook)      _NG_HOOK_FORCE_WRITER(hook)
#define NG_HOOK_FORCE_QUEUE(hook)       _NG_HOOK_FORCE_QUEUE(hook)
#define NG_HOOK_SET_TO_INBOUND(hook)    _NG_HOOK_SET_TO_INBOUND(hook)
#define NG_HOOK_HI_STACK(hook)          _NG_HOOK_HI_STACK(hook)

#endif  /* NETGRAPH_DEBUG */ /*----------------------------------------------*/

/***********************************************************************
 ***************** Node Structure and Methods **************************
 ***********************************************************************
 * Structure of a node
 * including the eembedded queue structure.
 *
 * The structure for queueing Netgraph request items
 * embedded in the node structure
 */
struct ng_queue {
        u_int           q_flags;        /* Current r/w/q lock flags */
        u_int           q_flags2;       /* Other queue flags */
        struct mtx      q_mtx;
        STAILQ_ENTRY(ng_node)   q_work; /* nodes with work to do */
        STAILQ_HEAD(, ng_item)  queue;  /* actually items queue */
};

struct ng_node {
        char    nd_name[NG_NODESIZ];    /* optional globally unique name */
        struct  ng_type *nd_type;       /* the installed 'type' */
        int     nd_flags;               /* see below for bit definitions */
        int     nd_numhooks;            /* number of hooks */
        void   *nd_private;             /* node type dependent node ID */
        ng_ID_t nd_ID;                  /* Unique per node */
        LIST_HEAD(hooks, ng_hook) nd_hooks;     /* linked list of node hooks */
        LIST_ENTRY(ng_node)       nd_nodes;     /* name hash collision list */
        LIST_ENTRY(ng_node)       nd_idnodes;   /* ID hash collision list */
        struct  ng_queue          nd_input_queue; /* input queue for locking */
        int     nd_refs;                /* # of references to this node */
        struct  vnet             *nd_vnet;      /* network stack instance */
#ifdef  NETGRAPH_DEBUG /*----------------------------------------------*/
#define ND_MAGIC 0x59264837
        int     nd_magic;
        char    *lastfile;
        int     lastline;
        SLIST_ENTRY(ng_node)      nd_all;       /* all existing nodes */
#endif  /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
};

/* Flags for a node */
#define NGF_INVALID     0x00000001      /* free when refs go to 0 */
#define NG_INVALID      NGF_INVALID     /* compat for old code */
#define NGF_FORCE_WRITER        0x00000004      /* Never multithread this node */
#define NG_FORCE_WRITER NGF_FORCE_WRITER /* compat for old code */
#define NGF_CLOSING     0x00000008      /* ng_rmnode() at work */
#define NG_CLOSING      NGF_CLOSING     /* compat for old code */
#define NGF_REALLY_DIE  0x00000010      /* "persistent" node is unloading */
#define NG_REALLY_DIE   NGF_REALLY_DIE  /* compat for old code */
#define NGF_HI_STACK    0x00000020      /* node has hi stack usage */
#define NGF_TYPE1       0x10000000      /* reserved for type specific storage */
#define NGF_TYPE2       0x20000000      /* reserved for type specific storage */
#define NGF_TYPE3       0x40000000      /* reserved for type specific storage */
#define NGF_TYPE4       0x80000000      /* reserved for type specific storage */

/*
 * Public methods for nodes.
 * If you can't do it with these you probably shouldn't be doing it.
 */
void    ng_unref_node(node_p node); /* don't move this */
#define _NG_NODE_NAME(node)     ((node)->nd_name + 0)
#define _NG_NODE_HAS_NAME(node) ((node)->nd_name[0] + 0)
#define _NG_NODE_ID(node)       ((node)->nd_ID + 0)
#define _NG_NODE_REF(node)      refcount_acquire(&(node)->nd_refs)
#define _NG_NODE_UNREF(node)    ng_unref_node(node)
#define _NG_NODE_SET_PRIVATE(node, val) do {(node)->nd_private = val;} while (0)
#define _NG_NODE_PRIVATE(node)  ((node)->nd_private)
#define _NG_NODE_IS_VALID(node) (!((node)->nd_flags & NGF_INVALID))
#define _NG_NODE_NOT_VALID(node)        ((node)->nd_flags & NGF_INVALID)
#define _NG_NODE_NUMHOOKS(node) ((node)->nd_numhooks + 0) /* rvalue */
#define _NG_NODE_FORCE_WRITER(node)                                     \
        do{ node->nd_flags |= NGF_FORCE_WRITER; }while (0)
#define _NG_NODE_HI_STACK(node)                                         \
        do{ node->nd_flags |= NGF_HI_STACK; }while (0)
#define _NG_NODE_REALLY_DIE(node)                                       \
        do{ node->nd_flags |= (NGF_REALLY_DIE|NGF_INVALID); }while (0)
#define _NG_NODE_REVIVE(node) \
        do { node->nd_flags &= ~NGF_INVALID; } while (0)
/*
 * The hook iterator.
 * This macro will call a function of type ng_fn_eachhook for each
 * hook attached to the node. If the function returns 0, then the
 * iterator will stop and return a pointer to the hook that returned 0.
 */
typedef int     ng_fn_eachhook(hook_p hook, void* arg);
#define _NG_NODE_FOREACH_HOOK(node, fn, arg)                            \
        do {                                                            \
                hook_p _hook;                                           \
                LIST_FOREACH(_hook, &((node)->nd_hooks), hk_hooks) {    \
                        if ((fn)(_hook, arg) == 0) {                    \
                                break;                                  \
                        }                                               \
                }                                                       \
        } while (0)

#ifdef  NETGRAPH_DEBUG /*----------------------------------------------*/
void    dumpnode(node_p node, char *file, int line);
static __inline void _chknode(node_p node, char *file, int line);
static __inline char * _ng_node_name(node_p node, char *file, int line);
static __inline int _ng_node_has_name(node_p node, char *file, int line);
static __inline ng_ID_t _ng_node_id(node_p node, char *file, int line);
static __inline void _ng_node_ref(node_p node, char *file, int line);
static __inline void _ng_node_unref(node_p node, char *file, int line);
static __inline void _ng_node_set_private(node_p node, void * val,
                                                        char *file, int line);
static __inline void * _ng_node_private(node_p node, char *file, int line);
static __inline int _ng_node_is_valid(node_p node, char *file, int line);
static __inline int _ng_node_not_valid(node_p node, char *file, int line);
static __inline int _ng_node_numhooks(node_p node, char *file, int line);
static __inline void _ng_node_force_writer(node_p node, char *file, int line);
static __inline void _ng_node_foreach_hook(node_p node,
                        ng_fn_eachhook *fn, void *arg, char *file, int line);
static __inline void _ng_node_revive(node_p node, char *file, int line);

static __inline void
_chknode(node_p node, char *file, int line)
{
        if (node->nd_magic != ND_MAGIC) {
                printf("Accessing freed ");
                dumpnode(node, file, line);
        }
        node->lastline = line;
        node->lastfile = file;
}

static __inline char *
_ng_node_name(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return(_NG_NODE_NAME(node));
}

static __inline int
_ng_node_has_name(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return(_NG_NODE_HAS_NAME(node));
}

static __inline ng_ID_t
_ng_node_id(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return(_NG_NODE_ID(node));
}

static __inline void
_ng_node_ref(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_REF(node);
}

static __inline void
_ng_node_unref(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_UNREF(node);
}

static __inline void
_ng_node_set_private(node_p node, void * val, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_SET_PRIVATE(node, val);
}

static __inline void *
_ng_node_private(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return (_NG_NODE_PRIVATE(node));
}

static __inline int
_ng_node_is_valid(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return(_NG_NODE_IS_VALID(node));
}

static __inline int
_ng_node_not_valid(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return(_NG_NODE_NOT_VALID(node));
}

static __inline int
_ng_node_numhooks(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        return(_NG_NODE_NUMHOOKS(node));
}

static __inline void
_ng_node_force_writer(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_FORCE_WRITER(node);
}

static __inline void
_ng_node_hi_stack(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_HI_STACK(node);
}

static __inline void
_ng_node_really_die(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_REALLY_DIE(node);
}

static __inline void
_ng_node_revive(node_p node, char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_REVIVE(node);
}

static __inline void
_ng_node_foreach_hook(node_p node, ng_fn_eachhook *fn, void *arg,
                                                char *file, int line)
{
        _chknode(node, file, line);
        _NG_NODE_FOREACH_HOOK(node, fn, arg);
}

#define NG_NODE_NAME(node)              _ng_node_name(node, _NN_)       
#define NG_NODE_HAS_NAME(node)          _ng_node_has_name(node, _NN_)   
#define NG_NODE_ID(node)                _ng_node_id(node, _NN_)
#define NG_NODE_REF(node)               _ng_node_ref(node, _NN_)
#define NG_NODE_UNREF(node)             _ng_node_unref(node, _NN_)
#define NG_NODE_SET_PRIVATE(node, val)  _ng_node_set_private(node, val, _NN_)
#define NG_NODE_PRIVATE(node)           _ng_node_private(node, _NN_)
#define NG_NODE_IS_VALID(node)          _ng_node_is_valid(node, _NN_)
#define NG_NODE_NOT_VALID(node)         _ng_node_not_valid(node, _NN_)
#define NG_NODE_FORCE_WRITER(node)      _ng_node_force_writer(node, _NN_)
#define NG_NODE_HI_STACK(node)          _ng_node_hi_stack(node, _NN_)
#define NG_NODE_REALLY_DIE(node)        _ng_node_really_die(node, _NN_)
#define NG_NODE_NUMHOOKS(node)          _ng_node_numhooks(node, _NN_)
#define NG_NODE_REVIVE(node)            _ng_node_revive(node, _NN_)
#define NG_NODE_FOREACH_HOOK(node, fn, arg)                             \
        _ng_node_foreach_hook(node, fn, (void *)arg, _NN_)

#else   /* NETGRAPH_DEBUG */ /*----------------------------------------------*/

#define NG_NODE_NAME(node)              _NG_NODE_NAME(node)     
#define NG_NODE_HAS_NAME(node)          _NG_NODE_HAS_NAME(node) 
#define NG_NODE_ID(node)                _NG_NODE_ID(node)       
#define NG_NODE_REF(node)               _NG_NODE_REF(node)      
#define NG_NODE_UNREF(node)             _NG_NODE_UNREF(node)    
#define NG_NODE_SET_PRIVATE(node, val)  _NG_NODE_SET_PRIVATE(node, val) 
#define NG_NODE_PRIVATE(node)           _NG_NODE_PRIVATE(node)  
#define NG_NODE_IS_VALID(node)          _NG_NODE_IS_VALID(node) 
#define NG_NODE_NOT_VALID(node)         _NG_NODE_NOT_VALID(node)        
#define NG_NODE_FORCE_WRITER(node)      _NG_NODE_FORCE_WRITER(node)
#define NG_NODE_HI_STACK(node)          _NG_NODE_HI_STACK(node)
#define NG_NODE_REALLY_DIE(node)        _NG_NODE_REALLY_DIE(node)
#define NG_NODE_NUMHOOKS(node)          _NG_NODE_NUMHOOKS(node) 
#define NG_NODE_REVIVE(node)            _NG_NODE_REVIVE(node)
#define NG_NODE_FOREACH_HOOK(node, fn, arg)                             \
        _NG_NODE_FOREACH_HOOK(node, fn, arg)
#endif  /* NETGRAPH_DEBUG */ /*----------------------------------------------*/

/***********************************************************************
 ************* Node Queue and Item Structures and Methods **************
 ***********************************************************************
 *
 */
typedef void    ng_item_fn(node_p node, hook_p hook, void *arg1, int arg2);
typedef int     ng_item_fn2(node_p node, struct ng_item *item, hook_p hook);
typedef void    ng_apply_t(void *context, int error);
struct ng_apply_info {
        ng_apply_t      *apply;
        void            *context;
        int             refs;
        int             error;
};
struct ng_item {
        u_long  el_flags;
        STAILQ_ENTRY(ng_item)   el_next;
        node_p  el_dest; /* The node it will be applied against (or NULL) */
        hook_p  el_hook; /* Entering hook. Optional in Control messages */
        union {
                struct mbuf     *da_m;
                struct {
                        struct ng_mesg  *msg_msg;
                        ng_ID_t         msg_retaddr;
                } msg;
                struct {
                        union {
                                ng_item_fn      *fn_fn;
                                ng_item_fn2     *fn_fn2;
                        } fn_fn;
                        void            *fn_arg1;
                        int             fn_arg2;
                } fn;
        } body;
        /*
         * Optional callback called when item is being applied,
         * and its context.
         */
        struct ng_apply_info    *apply;
        u_int   depth;
#ifdef  NETGRAPH_DEBUG /*----------------------------------------------*/
        char *lastfile;
        int  lastline;
        TAILQ_ENTRY(ng_item)      all;          /* all existing items */
#endif  /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
};

#define NGQF_TYPE       0x03            /* MASK of content definition */
#define NGQF_MESG       0x00            /* the queue element is a message */
#define NGQF_DATA       0x01            /* the queue element is data */
#define NGQF_FN         0x02            /* the queue element is a function */
#define NGQF_FN2        0x03            /* the queue element is a new function */

#define NGQF_RW         0x04            /* MASK for wanted queue mode */
#define NGQF_READER     0x04            /* wants to be a reader */
#define NGQF_WRITER     0x00            /* wants to be a writer */

#define NGQF_QMODE      0x08            /* MASK for how it was queued */
#define NGQF_QREADER    0x08            /* was queued as a reader */
#define NGQF_QWRITER    0x00            /* was queued as a writer */

/*
 * Get the mbuf (etc) out of an item.
 * Sets the value in the item to NULL in case we need to call NG_FREE_ITEM()
 * with it, (to avoid freeing the things twice).
 * If you don't want to zero out the item then realise that the
 * item still owns it.
 * Retaddr is different. There are no references on that. It's just a number.
 * The debug versions must be either all used everywhere or not at all.
 */

#define _NGI_M(i) ((i)->body.da_m)
#define _NGI_MSG(i) ((i)->body.msg.msg_msg)
#define _NGI_RETADDR(i) ((i)->body.msg.msg_retaddr)
#define _NGI_FN(i) ((i)->body.fn.fn_fn.fn_fn)
#define _NGI_FN2(i) ((i)->body.fn.fn_fn.fn_fn2)
#define _NGI_ARG1(i) ((i)->body.fn.fn_arg1)
#define _NGI_ARG2(i) ((i)->body.fn.fn_arg2)
#define _NGI_NODE(i) ((i)->el_dest)
#define _NGI_HOOK(i) ((i)->el_hook)
#define _NGI_SET_HOOK(i,h) do { _NGI_HOOK(i) = h; h = NULL;} while (0)
#define _NGI_CLR_HOOK(i)   do {                                         \
                hook_p _hook = _NGI_HOOK(i);                            \
                if (_hook) {                                            \
                        _NG_HOOK_UNREF(_hook);                          \
                        _NGI_HOOK(i) = NULL;                            \
                }                                                       \
        } while (0)
#define _NGI_SET_NODE(i,n) do { _NGI_NODE(i) = n; n = NULL;} while (0)
#define _NGI_CLR_NODE(i)   do {                                         \
                node_p _node = _NGI_NODE(i);                            \
                if (_node) {                                            \
                        _NG_NODE_UNREF(_node);                          \
                        _NGI_NODE(i) = NULL;                            \
                }                                                       \
        } while (0)

#ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
void                            dumpitem(item_p item, char *file, int line);
static __inline void            _ngi_check(item_p item, char *file, int line) ;
static __inline struct mbuf **  _ngi_m(item_p item, char *file, int line) ;
static __inline ng_ID_t *       _ngi_retaddr(item_p item, char *file, int line);
static __inline struct ng_mesg ** _ngi_msg(item_p item, char *file, int line) ;
static __inline ng_item_fn **   _ngi_fn(item_p item, char *file, int line) ;
static __inline ng_item_fn2 **  _ngi_fn2(item_p item, char *file, int line) ;
static __inline void **         _ngi_arg1(item_p item, char *file, int line) ;
static __inline int *           _ngi_arg2(item_p item, char *file, int line) ;
static __inline node_p          _ngi_node(item_p item, char *file, int line);
static __inline hook_p          _ngi_hook(item_p item, char *file, int line);

static __inline void
_ngi_check(item_p item, char *file, int line)
{
        (item)->lastline = line;
        (item)->lastfile = file;
}

static __inline struct mbuf **
_ngi_m(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_M(item));
}

static __inline struct ng_mesg **
_ngi_msg(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_MSG(item));
}

static __inline ng_ID_t *
_ngi_retaddr(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_RETADDR(item));
}

static __inline ng_item_fn **
_ngi_fn(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_FN(item));
}

static __inline ng_item_fn2 **
_ngi_fn2(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_FN2(item));
}

static __inline void **
_ngi_arg1(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_ARG1(item));
}

static __inline int *
_ngi_arg2(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (&_NGI_ARG2(item));
}

static __inline node_p
_ngi_node(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (_NGI_NODE(item));
}

static __inline hook_p
_ngi_hook(item_p item, char *file, int line)
{
        _ngi_check(item, file, line);
        return (_NGI_HOOK(item));
}

#define NGI_M(i)        (*_ngi_m(i, _NN_))
#define NGI_MSG(i)      (*_ngi_msg(i, _NN_))
#define NGI_RETADDR(i)  (*_ngi_retaddr(i, _NN_))
#define NGI_FN(i)       (*_ngi_fn(i, _NN_))
#define NGI_FN2(i)      (*_ngi_fn2(i, _NN_))
#define NGI_ARG1(i)     (*_ngi_arg1(i, _NN_))
#define NGI_ARG2(i)     (*_ngi_arg2(i, _NN_))
#define NGI_HOOK(i)     _ngi_hook(i, _NN_)
#define NGI_NODE(i)     _ngi_node(i, _NN_)
#define NGI_SET_HOOK(i,h)                                               \
        do { _ngi_check(i, _NN_); _NGI_SET_HOOK(i, h); } while (0)
#define NGI_CLR_HOOK(i)                                                 \
        do { _ngi_check(i, _NN_); _NGI_CLR_HOOK(i); } while (0)
#define NGI_SET_NODE(i,n)                                               \
        do { _ngi_check(i, _NN_); _NGI_SET_NODE(i, n); } while (0)
#define NGI_CLR_NODE(i)                                                 \
        do { _ngi_check(i, _NN_); _NGI_CLR_NODE(i); } while (0)

#define NG_FREE_ITEM(item)                                              \
        do {                                                            \
                _ngi_check(item, _NN_);                                 \
                ng_free_item((item));                                   \
        } while (0)

#define SAVE_LINE(item)                                                 \
        do {                                                            \
                (item)->lastline = __LINE__;                            \
                (item)->lastfile = __FILE__;                            \
        } while (0)

#else   /* NETGRAPH_DEBUG */ /*----------------------------------------------*/

#define NGI_M(i)        _NGI_M(i)
#define NGI_MSG(i)      _NGI_MSG(i)
#define NGI_RETADDR(i)  _NGI_RETADDR(i)
#define NGI_FN(i)       _NGI_FN(i)
#define NGI_FN2(i)      _NGI_FN2(i)
#define NGI_ARG1(i)     _NGI_ARG1(i)
#define NGI_ARG2(i)     _NGI_ARG2(i)
#define NGI_NODE(i)     _NGI_NODE(i)
#define NGI_HOOK(i)     _NGI_HOOK(i)
#define NGI_SET_HOOK(i,h) _NGI_SET_HOOK(i,h)
#define NGI_CLR_HOOK(i)   _NGI_CLR_HOOK(i)
#define NGI_SET_NODE(i,n) _NGI_SET_NODE(i,n)
#define NGI_CLR_NODE(i)   _NGI_CLR_NODE(i)

#define NG_FREE_ITEM(item)      ng_free_item((item))
#define SAVE_LINE(item)         do {} while (0)

#endif  /* NETGRAPH_DEBUG */ /*----------------------------------------------*/

#define NGI_GET_M(i,m)                                                  \
        do {                                                            \
                (m) = NGI_M(i);                                         \
                _NGI_M(i) = NULL;                                       \
        } while (0)

#define NGI_GET_MSG(i,m)                                                \
        do {                                                            \
                (m) = NGI_MSG(i);                                       \
                _NGI_MSG(i) = NULL;                                     \
        } while (0)

#define NGI_GET_NODE(i,n)       /* YOU NOW HAVE THE REFERENCE */        \
        do {                                                            \
                (n) = NGI_NODE(i);                                      \
                _NGI_NODE(i) = NULL;                                    \
        } while (0)

#define NGI_GET_HOOK(i,h)                                               \
        do {                                                            \
                (h) = NGI_HOOK(i);                                      \
                _NGI_HOOK(i) = NULL;                                    \
        } while (0)

#define NGI_SET_WRITER(i)       ((i)->el_flags &= ~NGQF_QMODE)
#define NGI_SET_READER(i)       ((i)->el_flags |= NGQF_QREADER)

#define NGI_QUEUED_READER(i)    ((i)->el_flags & NGQF_QREADER)
#define NGI_QUEUED_WRITER(i)    (((i)->el_flags & NGQF_QMODE) == NGQF_QWRITER)

/**********************************************************************
* Data macros.  Send, manipulate and free.
**********************************************************************/
/*
 * Assuming the data is already ok, just set the new address and send
 */
#define NG_FWD_ITEM_HOOK_FLAGS(error, item, hook, flags)                \
        do {                                                            \
                (error) =                                               \
                    ng_address_hook(NULL, (item), (hook), NG_NOFLAGS);  \
                if (error == 0) {                                       \
                        SAVE_LINE(item);                                \
                        (error) = ng_snd_item((item), (flags));         \
                }                                                       \
                (item) = NULL;                                          \
        } while (0)
#define NG_FWD_ITEM_HOOK(error, item, hook)     \
                NG_FWD_ITEM_HOOK_FLAGS(error, item, hook, NG_NOFLAGS)

/*
 * Forward a data packet. Mbuf pointer is updated to new value. We
 * presume you dealt with the old one when you update it to the new one
 * (or it maybe the old one). We got a packet and possibly had to modify
 * the mbuf. You should probably use NGI_GET_M() if you are going to use
 * this too.
 */
#define NG_FWD_NEW_DATA_FLAGS(error, item, hook, m, flags)              \
        do {                                                            \
                NGI_M(item) = (m);                                      \
                (m) = NULL;                                             \
                NG_FWD_ITEM_HOOK_FLAGS(error, item, hook, flags);       \
        } while (0)
#define NG_FWD_NEW_DATA(error, item, hook, m)   \
                NG_FWD_NEW_DATA_FLAGS(error, item, hook, m, NG_NOFLAGS)

/* Send a previously unpackaged mbuf. XXX: This should be called
 * NG_SEND_DATA in future, but this name is kept for compatibility
 * reasons.
 */
#define NG_SEND_DATA_FLAGS(error, hook, m, flags)                       \
        do {                                                            \
                item_p _item;                                           \
                if ((_item = ng_package_data((m), flags))) {            \
                        NG_FWD_ITEM_HOOK_FLAGS(error, _item, hook, flags);\
                } else {                                                \
                        (error) = ENOMEM;                               \
                }                                                       \
                (m) = NULL;                                             \
        } while (0)

#define NG_SEND_DATA_ONLY(error, hook, m)       \
                NG_SEND_DATA_FLAGS(error, hook, m, NG_NOFLAGS)
/* NG_SEND_DATA() compat for meta-data times */
#define NG_SEND_DATA(error, hook, m, x) \
                NG_SEND_DATA_FLAGS(error, hook, m, NG_NOFLAGS)

#define NG_FREE_MSG(msg)                                                \
        do {                                                            \
                if ((msg)) {                                            \
                        free((msg), M_NETGRAPH_MSG);                    \
                        (msg) = NULL;                                   \
                }                                                       \
        } while (0)

#define NG_FREE_M(m)                                                    \
        do {                                                            \
                if ((m)) {                                              \
                        m_freem((m));                                   \
                        (m) = NULL;                                     \
                }                                                       \
        } while (0)

/*****************************************
* Message macros
*****************************************/

#define NG_SEND_MSG_HOOK(error, here, msg, hook, retaddr)               \
        do {                                                            \
                item_p _item;                                           \
                if ((_item = ng_package_msg(msg, NG_NOFLAGS)) == NULL) {\
                        (msg) = NULL;                                   \
                        (error) = ENOMEM;                               \
                        break;                                          \
                }                                                       \
                if (((error) = ng_address_hook((here), (_item),         \
                                        (hook), (retaddr))) == 0) {     \
                        SAVE_LINE(_item);                               \
                        (error) = ng_snd_item((_item), 0);              \
                }                                                       \
                (msg) = NULL;                                           \
        } while (0)

#define NG_SEND_MSG_PATH(error, here, msg, path, retaddr)               \
        do {                                                            \
                item_p _item;                                           \
                if ((_item = ng_package_msg(msg, NG_NOFLAGS)) == NULL) {\
                        (msg) = NULL;                                   \
                        (error) = ENOMEM;                               \
                        break;                                          \
                }                                                       \
                if (((error) = ng_address_path((here), (_item),         \
                                        (path), (retaddr))) == 0) {     \
                        SAVE_LINE(_item);                               \
                        (error) = ng_snd_item((_item), 0);              \
                }                                                       \
                (msg) = NULL;                                           \
        } while (0)

#define NG_SEND_MSG_ID(error, here, msg, ID, retaddr)                   \
        do {                                                            \
                item_p _item;                                           \
                if ((_item = ng_package_msg(msg, NG_NOFLAGS)) == NULL) {\
                        (msg) = NULL;                                   \
                        (error) = ENOMEM;                               \
                        break;                                          \
                }                                                       \
                if (((error) = ng_address_ID((here), (_item),           \
                                        (ID), (retaddr))) == 0) {       \
                        SAVE_LINE(_item);                               \
                        (error) = ng_snd_item((_item), 0);              \
                }                                                       \
                (msg) = NULL;                                           \
        } while (0)

/*
 * Redirect the message to the next hop using the given hook.
 * ng_retarget_msg() frees the item if there is an error
 * and returns an error code.  It returns 0 on success.
 */
#define NG_FWD_MSG_HOOK(error, here, item, hook, retaddr)               \
        do {                                                            \
                if (((error) = ng_address_hook((here), (item),          \
                                        (hook), (retaddr))) == 0) {     \
                        SAVE_LINE(item);                                \
                        (error) = ng_snd_item((item), 0);               \
                }                                                       \
                (item) = NULL;                                          \
        } while (0)

/*
 * Send a queue item back to it's originator with a response message.
 * Assume original message was removed and freed separatly.
 */
#define NG_RESPOND_MSG(error, here, item, resp)                         \
        do {                                                            \
                if (resp) {                                             \
                        ng_ID_t _dest = NGI_RETADDR(item);              \
                        NGI_RETADDR(item) = 0;                          \
                        NGI_MSG(item) = resp;                           \
                        if ((error = ng_address_ID((here), (item),      \
                                        _dest, 0)) == 0) {              \
                                SAVE_LINE(item);                        \
                                (error) = ng_snd_item((item), NG_QUEUE);\
                        }                                               \
                } else                                                  \
                        NG_FREE_ITEM(item);                             \
                (item) = NULL;                                          \
        } while (0)

/***********************************************************************
 ******** Structures Definitions and Macros for defining a node  *******
 ***********************************************************************
 *
 * Here we define the structures needed to actually define a new node
 * type.
 */

/*
 * Command list -- each node type specifies the command that it knows
 * how to convert between ASCII and binary using an array of these.
 * The last element in the array must be a terminator with cookie=0.
 */

struct ng_cmdlist {
        u_int32_t                       cookie;         /* command typecookie */
        int                             cmd;            /* command number */
        const char                      *name;          /* command name */
        const struct ng_parse_type      *mesgType;      /* args if !NGF_RESP */
        const struct ng_parse_type      *respType;      /* args if NGF_RESP */
};

/*
 * Structure of a node type
 * If data is sent to the "rcvdata()" entrypoint then the system
 * may decide to defer it until later by queing it with the normal netgraph
 * input queuing system.  This is decidde by the HK_QUEUE flag being set in
 * the flags word of the peer (receiving) hook. The dequeuing mechanism will
 * ensure it is not requeued again.
 * Note the input queueing system is to allow modules
 * to 'release the stack' or to pass data across spl layers.
 * The data will be redelivered as soon as the NETISR code runs
 * which may be almost immediately.  A node may also do it's own queueing
 * for other reasons (e.g. device output queuing).
 */
struct ng_type {
        u_int32_t       version;        /* must equal NG_API_VERSION */
        const char      *name;          /* Unique type name */
        modeventhand_t  mod_event;      /* Module event handler (optional) */
        ng_constructor_t *constructor;  /* Node constructor */
        ng_rcvmsg_t     *rcvmsg;        /* control messages come here */
        ng_close_t      *close;         /* warn about forthcoming shutdown */
        ng_shutdown_t   *shutdown;      /* reset, and free resources */
        ng_newhook_t    *newhook;       /* first notification of new hook */
        ng_findhook_t   *findhook;      /* only if you have lots of hooks */
        ng_connect_t    *connect;       /* final notification of new hook */
        ng_rcvdata_t    *rcvdata;       /* data comes here */
        ng_disconnect_t *disconnect;    /* notify on disconnect */

        const struct    ng_cmdlist *cmdlist;    /* commands we can convert */

        /* R/W data private to the base netgraph code DON'T TOUCH! */
        LIST_ENTRY(ng_type) types;              /* linked list of all types */
        int                 refs;               /* number of instances */
};

/*
 * Use the NETGRAPH_INIT() macro to link a node type into the
 * netgraph system. This works for types compiled into the kernel
 * as well as KLD modules. The first argument should be the type
 * name (eg, echo) and the second a pointer to the type struct.
 *
 * If a different link time is desired, e.g., a device driver that
 * needs to install its netgraph type before probing, use the
 * NETGRAPH_INIT_ORDERED() macro instead.  Device drivers probably
 * want to use SI_SUB_DRIVERS/SI_ORDER_FIRST.
 */

#define NETGRAPH_INIT_ORDERED(typename, typestructp, sub, order)        \
static moduledata_t ng_##typename##_mod = {                             \
        "ng_" #typename,                                                \
        ng_mod_event,                                                   \
        (typestructp)                                                   \
};                                                                      \
DECLARE_MODULE(ng_##typename, ng_##typename##_mod, sub, order);         \
MODULE_DEPEND(ng_##typename, netgraph,  NG_ABI_VERSION,                 \
                                        NG_ABI_VERSION,                 \
                                        NG_ABI_VERSION)

#define NETGRAPH_INIT(tn, tp)                                           \
        NETGRAPH_INIT_ORDERED(tn, tp, SI_SUB_PSEUDO, SI_ORDER_MIDDLE)

/* Special malloc() type for netgraph structs and ctrl messages */
/* Only these two types should be visible to nodes */
MALLOC_DECLARE(M_NETGRAPH);
MALLOC_DECLARE(M_NETGRAPH_MSG);

/* declare the base of the netgraph sysclt hierarchy */
/* but only if this file cares about sysctls */
#ifdef  SYSCTL_DECL
SYSCTL_DECL(_net_graph);
#endif

/*
 * Methods that the nodes can use.
 * Many of these methods should usually NOT be used directly but via
 * Macros above.
 */
int     ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr);
int     ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr);
int     ng_address_path(node_p here, item_p item, const char *address, ng_ID_t raddr);
int     ng_bypass(hook_p hook1, hook_p hook2);
hook_p  ng_findhook(node_p node, const char *name);
struct  ng_type *ng_findtype(const char *type);
int     ng_make_node_common(struct ng_type *typep, node_p *nodep);
int     ng_name_node(node_p node, const char *name);
node_p  ng_name2noderef(node_p node, const char *name);
int     ng_newtype(struct ng_type *tp);
ng_ID_t ng_node2ID(node_cp node);
item_p  ng_package_data(struct mbuf *m, int flags);
item_p  ng_package_msg(struct ng_mesg *msg, int flags);
item_p  ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg);
void    ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr);
int     ng_rmhook_self(hook_p hook);    /* if a node wants to kill a hook */
int     ng_rmnode_self(node_p here);    /* if a node wants to suicide */
int     ng_rmtype(struct ng_type *tp);
int     ng_snd_item(item_p item, int queue);
int     ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void *arg1,
        int arg2);
int     ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void *arg1,
        int arg2, int flags);
int     ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn,
        void *arg1, int arg2, int flags);
int     ng_uncallout(struct callout *c, node_p node);
int     ng_uncallout_drain(struct callout *c, node_p node);
int     ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
            ng_item_fn *fn, void * arg1, int arg2);
#define ng_callout_init(c)      callout_init(c, 1)

/* Flags for netgraph functions. */
#define NG_NOFLAGS      0x00000000      /* no special options */
#define NG_QUEUE        0x00000001      /* enqueue item, don't dispatch */
#define NG_WAITOK       0x00000002      /* use M_WAITOK, etc. */
/* XXXGL: NG_PROGRESS unused since ng_base.c rev. 1.136. Should be deleted? */
#define NG_PROGRESS     0x00000004      /* return EINPROGRESS if queued */
#define NG_REUSE_ITEM   0x00000008      /* supplied item should be reused */

/*
 * prototypes the user should DEFINITELY not use directly
 */
void    ng_free_item(item_p item); /* Use NG_FREE_ITEM instead */
int     ng_mod_event(module_t mod, int what, void *arg);

/*
 * Tag definitions and constants
 */

#define NG_TAG_PRIO     1

struct ng_tag_prio {
        struct m_tag    tag;
        char    priority;
        char    discardability;
};

#define NG_PRIO_CUTOFF          32
#define NG_PRIO_LINKSTATE       64

/* Macros and declarations to keep compatibility with metadata, which
 * is obsoleted now. To be deleted.
 */
typedef void *meta_p;
#define _NGI_META(i)    NULL
#define NGI_META(i)     NULL
#define NG_FREE_META(meta)
#define NGI_GET_META(i,m)
#define ng_copy_meta(meta) NULL

/*
 * Mark the current thread when called from the outbound path of the
 * network stack, in order to enforce queuing on ng nodes calling into
 * the inbound network stack path.
 */
#define NG_OUTBOUND_THREAD_REF()                                        \
        curthread->td_ng_outbound++
#define NG_OUTBOUND_THREAD_UNREF()                                      \
        do {                                                            \
                curthread->td_ng_outbound--;                            \
                KASSERT(curthread->td_ng_outbound >= 0,                 \
                    ("%s: negative td_ng_outbound", __func__));         \
        } while (0)

#endif /* _NETGRAPH_NETGRAPH_H_ */