/*
 * 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>
 *
 * $FreeBSD: src/sys/netgraph/netgraph.h,v 1.6.2.7 2002/04/14 23:31:08 julian Exp $
 * $Whistle: netgraph.h,v 1.29 1999/11/01 07:56:13 julian Exp $
 */

#ifndef _NETGRAPH_NETGRAPH_H_
#define _NETGRAPH_NETGRAPH_H_

#ifndef _SYS_QUEUE_H_
#include <sys/queue.h>
#endif
#ifndef _SYS_MODULE_H_
#include <sys/module.h>
#endif
#ifndef _SYS_MBUF_H_
#include <sys/mbuf.h>
#endif
#ifndef _NETGRAPH_NG_MESSAGE_H_
#include <netgraph/ng_message.h>
#endif

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

#define NG_ABI_VERSION NG_VERSION

/*
 * Structure of a hook
 */
struct ng_hook {
        char   *name;           /* what this node knows this link as */
        void   *private;        /* node dependant ID for this hook */
        int     flags;          /* info about this hook/link */
        int     refs;           /* dont actually free this till 0 */
        struct  ng_hook *peer;  /* the other end of this link */
        struct  ng_node *node;  /* The node this hook is attached to */
        LIST_ENTRY(ng_hook) hooks;      /* linked list of all hooks on node */
};
typedef struct ng_hook *hook_p;

/* Flags for a hook */
#define HK_INVALID              0x0001  /* don't trust it! */

void ng_unref_hook(hook_p hook); /* don't move this */
#define NG_HOOK_REF(hook)       atomic_add_int(&(hook)->refs, 1)
#define NG_HOOK_NAME(hook)      ((hook)->name)
#define NG_HOOK_UNREF(hook)     ng_unref_hook(hook)
#define NG_HOOK_SET_PRIVATE(hook, val)  do {(hook)->private = val;} while (0)
#define NG_HOOK_SET_RCVMSG(hook, val)   do {(hook)->rcvmsg = val;} while (0)
#define NG_HOOK_SET_RCVDATA(hook, val)  do {(hook)->rcvdata = val;} while (0)
#define NG_HOOK_PRIVATE(hook)   ((hook)->private)
#define NG_HOOK_NOT_VALID(hook) ((hook)->flags & HK_INVALID)
#define NG_HOOK_IS_VALID(hook)  (!((hook)->flags & HK_INVALID))
#define NG_HOOK_NODE(hook)      ((hook)->node) /* only rvalue! */
#define NG_HOOK_PEER(hook)      ((hook)->peer) /* only rvalue! */

/* 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))

/*
 * Structure of a node
 */
struct ng_node {
        char   *name;           /* optional globally unique name */
        struct  ng_type *type;  /* the installed 'type' */
        int     flags;          /* see below for bit definitions */
        int     sleepers;       /* #procs sleeping on this node */
        int     refs;           /* number of references to this node */
        int     numhooks;       /* number of hooks */
        int     colour;         /* for graph colouring algorithms */
        void   *private;        /* node type dependant node ID */
        ng_ID_t         ID;     /* Unique per node */
        LIST_HEAD(hooks, ng_hook) hooks;        /* linked list of node hooks */
        LIST_ENTRY(ng_node)       nodes;        /* linked list of all nodes */
        LIST_ENTRY(ng_node)       idnodes;      /* ID hash collision list */
};
typedef struct ng_node *node_p;

/* Flags for a node */
#define NG_INVALID      0x001   /* free when all sleepers and refs go to 0 */
#define NG_BUSY         0x002   /* callers should sleep or wait */
#define NG_TOUCHED      0x004   /* to avoid cycles when 'flooding' */
#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 */

void    ng_unref_node(node_p node); /* don't move this */
#define NG_NODE_NAME(node)      ((node)->name + 0)
#define NG_NODE_HAS_NAME(node)  ((node)->name[0] + 0)
#define NG_NODE_ID(node)        ((node)->ID + 0)
#define NG_NODE_REF(node)       atomic_add_int(&(node)->refs, 1)
#define NG_NODE_UNREF(node)     ng_unref(node)
#define NG_NODE_SET_PRIVATE(node, val)  do {(node)->private = val;} while (0)
#define NG_NODE_PRIVATE(node)   ((node)->private)
#define NG_NODE_IS_VALID(node)  (!((node)->flags & NG_INVALID))
#define NG_NODE_NOT_VALID(node) ((node)->flags & NG_INVALID)
#define NG_NODE_NUMHOOKS(node)  ((node)->numhooks + 0) /* rvalue */

/*
 * The structure that holds meta_data about a data packet (e.g. priority)
 * Nodes might add or subtract options as needed if there is room.
 * They might reallocate the struct to make more room if they need to.
 * Meta-data is still experimental.
 */
struct meta_field_header {
        u_long  cookie;         /* cookie for the field. Skip fields you don't
                                 * know about (same cookie as in messgaes) */
        u_short type;           /* field ID */
        u_short len;            /* total len of this field including extra
                                 * data */
        char    data[0];        /* data starts here */
};

/* To zero out an option 'in place' set it's cookie to this */
#define NGM_INVALID_COOKIE      865455152

/* This part of the metadata is always present if the pointer is non NULL */
struct ng_meta {
        char    priority;       /* -ve is less priority,  0 is default */
        char    discardability; /* higher is less valuable.. discard first */
        u_short allocated_len;  /* amount malloc'd */
        u_short used_len;       /* sum of all fields, options etc. */
        u_short flags;          /* see below.. generic flags */
        struct meta_field_header options[0];    /* add as (if) needed */
};
typedef struct ng_meta *meta_p;

/* Flags for meta-data */
#define NGMF_TEST       0x01    /* discard at the last moment before sending */
#define NGMF_TRACE      0x02    /* trace when handing this data to a node */

/* node method definitions */
typedef int     ng_constructor_t(node_p *node);
typedef int     ng_rcvmsg_t(node_p node, struct ng_mesg *msg,
                        const char *retaddr, struct ng_mesg **resp);
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_rcvdata_t(hook_p hook, struct mbuf *m, meta_p meta);
typedef int     ng_disconnect_t(hook_p hook);

/*
 * 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
 */
struct ng_type {

        u_int32_t       version;        /* must equal NG_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_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;       /* date comes here */
        ng_rcvdata_t    *rcvdataq;      /* or here if being queued */
        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 */
};

/* Send data packet with meta-data */
#define NG_SEND_DATA(error, hook, m, a)                                 \
        do {                                                            \
                (error) = ng_send_data((hook), (m), (a));               \
                (m) = NULL;                                             \
                (a) = NULL;                                             \
        } while (0)

#define NG_SEND_DATA_ONLY(error, hook, m)                               \
        do {                                                            \
                (error) = ng_send_data((hook), (m), NULL);              \
                (m) = NULL;                                             \
        } while (0)

/* Send  queued data packet with meta-data */
#define NG_SEND_DATAQ(error, hook, m, a)                                \
        do {                                                            \
                (error) = ng_send_dataq((hook), (m), (a));              \
                (m) = NULL;                                             \
                (a) = NULL;                                             \
        } while (0)

#define NG_RESPOND_MSG(error, here, retaddr, resp, rptr)                \
        do {                                                            \
                if (rptr) {                                             \
                        *rptr = resp;                                   \
                } else if (resp) {                                      \
                        if (retaddr) {                                  \
                                error = ng_queue_msg(here, resp, retaddr); \
                        } else {                                        \
                                kfree(resp, M_NETGRAPH);                \
                        }                                               \
                }                                                       \
        } while (0)

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

#define NG_FREE_META(a)                                                 \
        do {                                                            \
                if ((a)) {                                              \
                        kfree((a), M_NETGRAPH);                         \
                        (a) = NULL;                                     \
                }                                                       \
        } while (0)

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

/* Free any data packet and/or meta-data */
#define NG_FREE_DATA(m, a)                                              \
        do {                                                            \
                NG_FREE_M((m));                                         \
                NG_FREE_META((a));                                      \
        } while (0)

/*
 * 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. Deivce drivers probably
 * want to use SI_SUB_DRIVERS instead of SI_SUB_PSEUDO.
 */

#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_VERSION(ng_##typename, NG_ABI_VERSION);                          \
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_ANY)

/* Special malloc() type for netgraph structs and ctrl messages */
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_NETGRAPH);
#endif

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

int     ng_bypass(hook_p hook1, hook_p hook2);
void    ng_cutlinks(node_p node);
int     ng_con_nodes(node_p node,
             const char *name, node_p node2, const char *name2);
meta_p  ng_copy_meta(meta_p meta);
void    ng_destroy_hook(hook_p hook);
hook_p  ng_findhook(node_p node, const char *name);
node_p  ng_findname(node_p node, const char *name);
struct  ng_type *ng_findtype(const char *type);
int     ng_make_node(const char *type, node_p *nodepp);
int     ng_make_node_common(struct ng_type *typep, node_p *nodep);
int     ng_mkpeer(node_p node, const char *name, const char *name2, char *type);
int     ng_mod_event(module_t mod, int what, void *arg);
int     ng_name_node(node_p node, const char *name);
int     ng_newtype(struct ng_type *tp);
ng_ID_t ng_node2ID(node_p node);
int     ng_path2node(node_p here, const char *path, node_p *dest, char **rtnp);
int     ng_path_parse(char *addr, char **node, char **path, char **hook);
int     ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta);
int     ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address);
void    ng_release_node(node_p node);
void    ng_rmnode(node_p node);
int     ng_send_data(hook_p hook, struct mbuf *m, meta_p meta);
int     ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta);
int     ng_send_msg(node_p here, struct ng_mesg *msg,
            const char *address, struct ng_mesg **resp);
void    ng_unname(node_p node);
void    ng_unref(node_p node);
int     ng_wait_node(node_p node, char *msg);

#endif  /* _NETGRAPH_NETGRAPH_H_ */