freebsd-skq/sys/netgraph/ng_echo.c
julian 49604b4259 Two simple changes to the kernel internal API for netgraph modules,
to support future work in flow-control and 'packet reject/replace'
processing modes.

reviewed by: phk, archie
2000-04-28 17:09:00 +00:00

120 lines
3.4 KiB
C

/*
* ng_echo.c
*
* 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 Elisher <julian@whistle.com>
*
* $FreeBSD$
* $Whistle: ng_echo.c,v 1.13 1999/11/01 09:24:51 julian Exp $
*/
/*
* Netgraph "echo" node
*
* This node simply bounces data and messages back to whence they came.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_echo.h>
/* Netgraph methods */
static ng_rcvmsg_t nge_rcvmsg;
static ng_rcvdata_t nge_rcvdata;
static ng_disconnect_t nge_disconnect;
/* Netgraph type */
static struct ng_type typestruct = {
NG_VERSION,
NG_ECHO_NODE_TYPE,
NULL,
NULL,
nge_rcvmsg,
NULL,
NULL,
NULL,
NULL,
nge_rcvdata,
nge_rcvdata,
nge_disconnect,
NULL
};
NETGRAPH_INIT(echo, &typestruct);
/*
* Receive control message. We just bounce it back as a reply.
*/
static int
nge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
struct ng_mesg **rptr, hook_p lasthook)
{
if (rptr) {
msg->header.flags |= NGF_RESP;
*rptr = msg;
} else {
FREE(msg, M_NETGRAPH);
}
return (0);
}
/*
* Receive data
*/
static int
nge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
struct mbuf **ret_m, meta_p *ret_meta)
{
int error = 0;
NG_SEND_DATA(error, hook, m, meta);
return (error);
}
/*
* Removal of the last link destroys the nodeo
*/
static int
nge_disconnect(hook_p hook)
{
if (hook->node->numhooks == 0)
ng_rmnode(hook->node);
return (0);
}