ng_gif_demux.c

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/*
 * ng_gif_demux.c
 */
 
/*-
 * SPDX-License-Identifier: BSD-3-Clause AND BSD-2-Clause
 *
 * Copyright 2001 The Aerospace Corporation.  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.
 * 3. The name of The Aerospace Corporation may not be used to endorse or
 *    promote products derived from this software.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AEROSPACE CORPORATION ``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 AEROSPACE CORPORATION 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.
 *
 *
 * 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.
 *
 * $FreeBSD$
 */
 
/*
 * ng_gif_demux(4) netgraph node type
 *
 * Packets received on the "gif" hook have their type header removed
 * and are passed to the appropriate hook protocol hook.  Packets
 * received on a protocol hook have a type header added back and are
 * passed out the gif hook. The currently supported protocol hooks are:
 */
 
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/ctype.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/socket.h>
 
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_gif_demux.h>
 
#ifdef NG_SEPARATE_MALLOC
static MALLOC_DEFINE(M_NETGRAPH_GIF_DEMUX, "netgraph_gif_demux",
    "netgraph gif demux node");
#else
#define M_NETGRAPH_GIF_DEMUX M_NETGRAPH
#endif
 
/* This struct describes one address family */
struct iffam {
        sa_family_t     family;         /* Address family */
        const char      *hookname;      /* Name for hook */
};
typedef const struct iffam *iffam_p;
 
/* List of address families supported by our interface */
const static struct iffam gFamilies[] = {
        { AF_INET,      NG_GIF_DEMUX_HOOK_INET  },
        { AF_INET6,     NG_GIF_DEMUX_HOOK_INET6 },
        { AF_APPLETALK, NG_GIF_DEMUX_HOOK_ATALK },
        { AF_IPX,       NG_GIF_DEMUX_HOOK_IPX   },
        { AF_ATM,       NG_GIF_DEMUX_HOOK_ATM   },
        { AF_NATM,      NG_GIF_DEMUX_HOOK_NATM  },
};
#define NUM_FAMILIES            nitems(gFamilies)
 
/* Per-node private data */
struct ng_gif_demux_private {
        node_p  node;                   /* Our netgraph node */
        hook_p  gif;                    /* The gif hook */
        hook_p  hooks[NUM_FAMILIES];    /* The protocol hooks */
};
typedef struct ng_gif_demux_private *priv_p;
 
/* Netgraph node methods */
static ng_constructor_t ng_gif_demux_constructor;
static ng_rcvmsg_t      ng_gif_demux_rcvmsg;
static ng_shutdown_t    ng_gif_demux_shutdown;
static ng_newhook_t     ng_gif_demux_newhook;
static ng_rcvdata_t     ng_gif_demux_rcvdata;
static ng_disconnect_t  ng_gif_demux_disconnect;
 
/* Helper stuff */
static iffam_p  get_iffam_from_af(sa_family_t family);
static iffam_p  get_iffam_from_hook(priv_p priv, hook_p hook);
static iffam_p  get_iffam_from_name(const char *name);
static hook_p   *get_hook_from_iffam(priv_p priv, iffam_p iffam);
 
/******************************************************************
                    NETGRAPH PARSE TYPES
******************************************************************/
 
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_gif_demux_cmdlist[] = {
        { 0 }
};
 
/* Node type descriptor */
static struct ng_type ng_gif_demux_typestruct = {
        .version =      NG_ABI_VERSION,
        .name =         NG_GIF_DEMUX_NODE_TYPE,
        .constructor =  ng_gif_demux_constructor,
        .rcvmsg =       ng_gif_demux_rcvmsg,
        .shutdown =     ng_gif_demux_shutdown,
        .newhook =      ng_gif_demux_newhook,
        .rcvdata =      ng_gif_demux_rcvdata,
        .disconnect =   ng_gif_demux_disconnect,
        .cmdlist =      ng_gif_demux_cmdlist,
};
NETGRAPH_INIT(gif_demux, &ng_gif_demux_typestruct);
 
/************************************************************************
                    HELPER STUFF
 ************************************************************************/
 
/*
 * Get the family descriptor from the family ID
 */
static __inline iffam_p
get_iffam_from_af(sa_family_t family)
{
        iffam_p iffam;
        int k;
 
        for (k = 0; k < NUM_FAMILIES; k++) {
                iffam = &gFamilies[k];
                if (iffam->family == family)
                        return (iffam);
        }
        return (NULL);
}
 
/*
 * Get the family descriptor from the hook
 */
static __inline iffam_p
get_iffam_from_hook(priv_p priv, hook_p hook)
{
        int k;
 
        for (k = 0; k < NUM_FAMILIES; k++)
                if (priv->hooks[k] == hook)
                        return (&gFamilies[k]);
        return (NULL);
}
 
/*
 * Get the hook from the iffam descriptor
 */
 
static __inline hook_p *
get_hook_from_iffam(priv_p priv, iffam_p iffam)
{
        return (&priv->hooks[iffam - gFamilies]);
}
 
/*
 * Get the iffam descriptor from the name
 */
static __inline iffam_p
get_iffam_from_name(const char *name)
{
        iffam_p iffam;
        int k;
 
        for (k = 0; k < NUM_FAMILIES; k++) {
                iffam = &gFamilies[k];
                if (!strcmp(iffam->hookname, name))
                        return (iffam);
        }
        return (NULL);
}
 
/******************************************************************
                    NETGRAPH NODE METHODS
******************************************************************/
 
/*
 * Node constructor
 */
static int
ng_gif_demux_constructor(node_p node)
{
        priv_p priv;
 
        /* Allocate and initialize private info */
        priv = malloc(sizeof(*priv), M_NETGRAPH_GIF_DEMUX, M_WAITOK | M_ZERO);
        priv->node = node;
 
        NG_NODE_SET_PRIVATE(node, priv);
 
        /* Done */
        return (0);
}
 
/*
 * Method for attaching a new hook
 */
static  int
ng_gif_demux_newhook(node_p node, hook_p hook, const char *name)
{
        const priv_p priv = NG_NODE_PRIVATE(node);
        iffam_p iffam;
        hook_p *hookptr;
 
        if (strcmp(NG_GIF_DEMUX_HOOK_GIF, name) == 0)
                hookptr = &priv->gif;
        else {
                iffam = get_iffam_from_name(name);
                if (iffam == NULL)
                        return (EPFNOSUPPORT);
                hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
        }
        if (*hookptr != NULL)
                return (EISCONN);
        *hookptr = hook;
        return (0);
}
 
/*
 * Receive a control message
 */
static int
ng_gif_demux_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        struct ng_mesg *resp = NULL;
        int error = 0;
        struct ng_mesg *msg;
 
        NGI_GET_MSG(item, msg);
        switch (msg->header.typecookie) {
        case NGM_GIF_DEMUX_COOKIE:
                switch (msg->header.cmd) {
                /* XXX: Add commands here. */
                default:
                        error = EINVAL;
                        break;
                }
                break;
        default:
                error = EINVAL;
                break;
        }
 
        /* Done */
        NG_RESPOND_MSG(error, node, item, resp);
        NG_FREE_MSG(msg);
        return (error);
}
 
/*
 * Receive data on a hook
 */
static int
ng_gif_demux_rcvdata(hook_p hook, item_p item)
{
        const node_p node = NG_HOOK_NODE(hook);
        const priv_p priv = NG_NODE_PRIVATE(node);
        iffam_p iffam;
        hook_p outhook;
        int error = 0;
        struct mbuf *m;
 
        /* Pull the mbuf out of the item for processing. */
        NGI_GET_M(item, m);
 
        if (hook == priv->gif) {
                /*
                 * Pull off the address family header and find the
                 * output hook.
                 */
                if (m->m_pkthdr.len < sizeof(sa_family_t)) {
                        NG_FREE_M(m);
                        NG_FREE_ITEM(item);
                        return (EINVAL);
                }
                if (m->m_len < sizeof(sa_family_t)
                    && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
                        NG_FREE_ITEM(item);
                        return (ENOBUFS);
                }
                iffam = get_iffam_from_af(*mtod(m, sa_family_t *));
                if (iffam == NULL) {
                        NG_FREE_M(m);
                        NG_FREE_ITEM(item);
                        return (EINVAL);
                }
                outhook = *get_hook_from_iffam(priv, iffam);
                m_adj(m, sizeof(sa_family_t));
        } else {
                /*
                 * Add address family header and set the output hook.
                 */
                iffam = get_iffam_from_hook(priv, hook);
                M_PREPEND(m, sizeof (iffam->family), M_NOWAIT);
                if (m == NULL) {
                        NG_FREE_M(m);
                        NG_FREE_ITEM(item);
                        return (ENOBUFS);
                }
                bcopy(&iffam->family, mtod(m, sa_family_t *),
                    sizeof(iffam->family));
                outhook = priv->gif;
        }
 
        /* Stuff the mbuf back in. */
        NGI_M(item) = m;
 
        /* Deliver packet */
        NG_FWD_ITEM_HOOK(error, item, outhook);
        return (error);
}
 
/*
 * Shutdown node
 */
static int
ng_gif_demux_shutdown(node_p node)
{
        const priv_p priv = NG_NODE_PRIVATE(node);
 
        free(priv, M_NETGRAPH_GIF_DEMUX);
        NG_NODE_SET_PRIVATE(node, NULL);
        NG_NODE_UNREF(node);
        return (0);
}
 
/*
 * Hook disconnection.
 */
static int
ng_gif_demux_disconnect(hook_p hook)
{
        const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        iffam_p iffam;
 
        if (hook == priv->gif)
                priv->gif = NULL;
        else {
                iffam = get_iffam_from_hook(priv, hook);
                if (iffam == NULL)
                        panic("%s", __func__);
                *get_hook_from_iffam(priv, iffam) = NULL;
        }
 
        return (0);
}