ng_hub.c

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/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2004 Ruslan Ermilov
 * 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.
 *
 * $FreeBSD$
 */
 
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
 
#include <netgraph/ng_message.h>
#include <netgraph/ng_hub.h>
#include <netgraph/netgraph.h>
 
#ifdef NG_SEPARATE_MALLOC
static MALLOC_DEFINE(M_NETGRAPH_HUB, "netgraph_hub", "netgraph hub node");
#else
#define M_NETGRAPH_HUB M_NETGRAPH
#endif
 
/* Per-node private data */
struct ng_hub_private {
        int             persistent;     /* can exist w/o hooks */
};
typedef struct ng_hub_private *priv_p;
 
/* Netgraph node methods */
static ng_constructor_t ng_hub_constructor;
static ng_rcvmsg_t      ng_hub_rcvmsg;
static ng_shutdown_t    ng_hub_shutdown;
static ng_rcvdata_t     ng_hub_rcvdata;
static ng_disconnect_t  ng_hub_disconnect;
 
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_hub_cmdlist[] = {
        {
                NGM_HUB_COOKIE,
                NGM_HUB_SET_PERSISTENT,
                "setpersistent",
                NULL,
                NULL
        },
        { 0 }
};
 
static struct ng_type ng_hub_typestruct = {
        .version =      NG_ABI_VERSION,
        .name =         NG_HUB_NODE_TYPE,
        .constructor =  ng_hub_constructor,
        .rcvmsg =       ng_hub_rcvmsg,
        .shutdown =     ng_hub_shutdown,
        .rcvdata =      ng_hub_rcvdata,
        .disconnect =   ng_hub_disconnect,
        .cmdlist =      ng_hub_cmdlist,
};
NETGRAPH_INIT(hub, &ng_hub_typestruct);
 
static int
ng_hub_constructor(node_p node)
{
        priv_p priv;
 
        /* Allocate and initialize private info */
        priv = malloc(sizeof(*priv), M_NETGRAPH_HUB, M_WAITOK | M_ZERO);
 
        NG_NODE_SET_PRIVATE(node, priv);
        return (0);
}
 
/*
 * Receive a control message
 */
static int
ng_hub_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        const priv_p priv = NG_NODE_PRIVATE(node);
        int error = 0;
        struct ng_mesg *msg;
 
        NGI_GET_MSG(item, msg);
        if (msg->header.typecookie == NGM_HUB_COOKIE &&
            msg->header.cmd == NGM_HUB_SET_PERSISTENT) {
                priv->persistent = 1;
        } else {
                error = EINVAL;
        }
 
        NG_FREE_MSG(msg);
        return (error);
}
 
static int
ng_hub_rcvdata(hook_p hook, item_p item)
{
        const node_p node = NG_HOOK_NODE(hook);
        int error = 0;
        hook_p hook2;
        struct mbuf * const m = NGI_M(item), *m2;
        int nhooks;
 
        if ((nhooks = NG_NODE_NUMHOOKS(node)) == 1) {
                NG_FREE_ITEM(item);
                return (0);
        }
        LIST_FOREACH(hook2, &node->nd_hooks, hk_hooks) {
                if (hook2 == hook)
                        continue;
                if (--nhooks == 1)
                        NG_FWD_ITEM_HOOK(error, item, hook2);
                else {
                        if ((m2 = m_dup(m, M_NOWAIT)) == NULL) {
                                NG_FREE_ITEM(item);
                                return (ENOBUFS);
                        }
                        NG_SEND_DATA_ONLY(error, hook2, m2);
                        if (error)
                                continue;       /* don't give up */
                }
        }
 
        return (error);
}
 
/*
 * Shutdown node
 */
static int
ng_hub_shutdown(node_p node)
{
        const priv_p priv = NG_NODE_PRIVATE(node);
 
        free(priv, M_NETGRAPH_HUB);
        NG_NODE_SET_PRIVATE(node, NULL);
        NG_NODE_UNREF(node);
        return (0);
}
 
static int
ng_hub_disconnect(hook_p hook)
{
        const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 
        if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
            NG_NODE_IS_VALID(NG_HOOK_NODE(hook)) && !priv->persistent)
                ng_rmnode_self(NG_HOOK_NODE(hook));
        return (0);
}