freebsd-dev/sys/netgraph/ng_split.c
Julian Elischer cdee49f986 Add a 'splitter' node to separate a bidirectional
packet flow into two unidirectional flows.

Part of a suite of nodes developed for packet flow control.
More to follow as I have time to port them to 5.x or
as others do so. The ipfw node will be the hardest..

Submitted by:	"Vitaly V. Belekhov" <vitaly@riss-telecom.ru>
2001-02-22 17:14:36 +00:00

228 lines
5.5 KiB
C

/*-
*
* Copyright (c) 1999-2000, Vitaly V Belekhov
* 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 unmodified, 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/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_split.h>
/* Netgraph methods */
static ng_constructor_t ng_split_constructor;
static ng_rcvmsg_t ng_split_rcvmsg;
static ng_shutdown_t ng_split_rmnode;
static ng_newhook_t ng_split_newhook;
static ng_rcvdata_t ng_split_rcvdata;
static ng_connect_t ng_split_connect;
static ng_disconnect_t ng_split_disconnect;
/* Node type descriptor */
static struct ng_type typestruct = {
NG_ABI_VERSION,
NG_SPLIT_NODE_TYPE,
NULL,
ng_split_constructor,
ng_split_rcvmsg,
ng_split_rmnode,
ng_split_newhook,
NULL,
ng_split_connect,
ng_split_rcvdata,
ng_split_disconnect,
NULL
};
NETGRAPH_INIT(ng_split, &typestruct);
/* Node private data */
struct ng_split_private {
hook_p outhook;
hook_p inhook;
hook_p mixed;
node_p node; /* Our netgraph node */
};
typedef struct ng_split_private *priv_p;
/************************************************************************
NETGRAPH NODE STUFF
************************************************************************/
/*
* Constructor for a node
*/
static int
ng_split_constructor(node_p node)
{
priv_p priv;
/* Allocate node */
MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_ZERO | M_NOWAIT);
if (priv == NULL)
return (ENOMEM);
bzero(priv, sizeof(*priv));
/* Link together node and private info */
NG_NODE_SET_PRIVATE(node, priv);
priv->node = node;
/* Done */
return (0);
}
/*
* Give our ok for a hook to be added
*/
static int
ng_split_newhook(node_p node, hook_p hook, const char *name)
{
priv_p priv = NG_NODE_PRIVATE(node);
if (strcmp(name, NG_SPLIT_HOOK_MIXED)) {
if (strcmp(name, NG_SPLIT_HOOK_INHOOK)) {
if (strcmp(name, NG_SPLIT_HOOK_OUTHOOK))
return (EPFNOSUPPORT);
else {
if (priv->outhook != NULL)
return (EISCONN);
priv->outhook = hook;
NG_HOOK_SET_PRIVATE(hook, &(priv->outhook));
}
} else {
if (priv->inhook != NULL)
return (EISCONN);
priv->inhook = hook;
NG_HOOK_SET_PRIVATE(hook, &(priv->inhook));
}
} else {
if (priv->mixed != NULL)
return (EISCONN);
priv->mixed = hook;
NG_HOOK_SET_PRIVATE(hook, &(priv->mixed));
}
return (0);
}
/*
* Receive a control message
*/
static int
ng_split_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
NG_FREE_ITEM(item);
return (EINVAL);
}
/*
* Recive data from a hook.
*/
static int
ng_split_rcvdata(hook_p hook, item_p item)
{
meta_p meta;
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
int error = 0;
if (hook == priv->outhook) {
printf("ng_split: got packet from outhook!\n");
NG_FREE_ITEM(item);
return (EINVAL);
}
#if 0 /* should never happen */
if (NGI_M(item) == NULL) {
printf("ng_split: mbuf is null.\n");
NG_FREE_ITEM(item);
return (EINVAL);
}
#endif
/*
* XXX Really here we should just remove metadata we understand.
*/
NGI_GET_META(item, meta);
NG_FREE_META(meta);
if ((hook == priv->inhook) && (priv->mixed)) {
NG_FWD_ITEM_HOOK(error, item, priv->mixed);
} else if ((hook == priv->mixed) && (priv->outhook)) {
NG_FWD_ITEM_HOOK(error, item, priv->outhook);
}
return (error);
}
static int
ng_split_rmnode(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
FREE(priv, M_NETGRAPH);
return (0);
}
/*
* This is called once we've already connected a new hook to the other node.
* It gives us a chance to balk at the last minute.
*/
static int
ng_split_connect(hook_p hook)
{
/* be really amiable and just say "YUP that's OK by me! " */
return (0);
}
/*
* Hook disconnection
*/
static int
ng_split_disconnect(hook_p hook)
{
if (NG_HOOK_PRIVATE(hook)) {
*((hook_p *)NG_HOOK_PRIVATE(hook)) = (hook_p)0;
}
if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
ng_rmnode_self(NG_HOOK_NODE(hook));
}
return (0);
}