/*
* ng_UI.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 Elischer <julian@freebsd.org>
*
* $FreeBSD$
* $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $
*/
#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 <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_UI.h>
/*
* DEFINITIONS
*/
/* Everything, starting with sdlc on has defined UI as 0x03 */
#define HDLC_UI 0x03
/* Node private data */
struct ng_UI_private {
hook_p downlink;
hook_p uplink;
};
typedef struct ng_UI_private *priv_p;
/* Netgraph node methods */
static ng_constructor_t ng_UI_constructor;
static ng_rcvmsg_t ng_UI_rcvmsg;
static ng_shutdown_t ng_UI_shutdown;
static ng_newhook_t ng_UI_newhook;
static ng_rcvdata_t ng_UI_rcvdata;
static ng_disconnect_t ng_UI_disconnect;
/* Node type descriptor */
static struct ng_type typestruct = {
NG_ABI_VERSION,
NG_UI_NODE_TYPE,
NULL,
ng_UI_constructor,
ng_UI_rcvmsg,
ng_UI_shutdown,
ng_UI_newhook,
NULL,
NULL,
ng_UI_rcvdata,
ng_UI_disconnect,
NULL
};
NETGRAPH_INIT(UI, &typestruct);
/************************************************************************
NETGRAPH NODE STUFF
************************************************************************/
/*
* Create a newborn node. We start with an implicit reference.
*/
static int
ng_UI_constructor(node_p node)
{
priv_p priv;
/* Allocate private structure */
MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
if (priv == NULL) {
return (ENOMEM);
}
NG_NODE_SET_PRIVATE(node, priv);
return (0);
}
/*
* Give our ok for a hook to be added
*/
static int
ng_UI_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = NG_NODE_PRIVATE(node);
if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) {
if (priv->downlink)
return (EISCONN);
priv->downlink = hook;
} else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) {
if (priv->uplink)
return (EISCONN);
priv->uplink = hook;
} else
return (EINVAL);
return (0);
}
/*
* Receive a control message
*/
static int
ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
int error;
const priv_p priv = NG_NODE_PRIVATE(node);
struct ng_mesg *msg;
msg = NGI_MSG(item); /* only peeking */
if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) {
if (lasthook == priv->downlink) {
if (priv->uplink) {
NG_FWD_ITEM_HOOK(error, item, priv->uplink);
return (error);
}
} else {
if (priv->downlink) {
NG_FWD_ITEM_HOOK(error, item, priv->downlink);
return (error);
}
}
}
NG_FREE_ITEM(item);
return (EINVAL);
}
#define MAX_ENCAPS_HDR 1
#define ERROUT(x) do { error = (x); goto done; } while (0)
/*
* Receive a data frame
*/
static int
ng_UI_rcvdata(hook_p hook, item_p item)
{
const node_p node = NG_HOOK_NODE(hook);
const priv_p priv = NG_NODE_PRIVATE(node);
struct mbuf *m;
int error = 0;
NGI_GET_M(item, m);
if (hook == priv->downlink) {
u_char *start, *ptr;
if (!m || (m->m_len < MAX_ENCAPS_HDR
&& !(m = m_pullup(m, MAX_ENCAPS_HDR))))
ERROUT(ENOBUFS);
ptr = start = mtod(m, u_char *);
/* Must be UI frame */
if (*ptr++ != HDLC_UI)
ERROUT(0);
m_adj(m, ptr - start);
NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */
} else if (hook == priv->uplink) {
M_PREPEND(m, 1, M_DONTWAIT); /* Prepend IP NLPID */
if (!m)
ERROUT(ENOBUFS);
mtod(m, u_char *)[0] = HDLC_UI;
NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */
} else
panic(__func__);
done:
NG_FREE_M(m); /* does nothing if m == NULL */
if (item)
NG_FREE_ITEM(item);
return (error);
}
/*
* Shutdown node
*/
static int
ng_UI_shutdown(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
/* Take down netgraph node */
FREE(priv, M_NETGRAPH);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
return (0);
}
/*
* Hook disconnection
*/
static int
ng_UI_disconnect(hook_p hook)
{
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
if (hook == priv->downlink)
priv->downlink = NULL;
else if (hook == priv->uplink)
priv->uplink = NULL;
else
panic(__func__);
/*
* If we are not already shutting down,
* and we have no more hooks, then DO shut down.
*/
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);
}
