freebsd-dev/sys/netgraph/ng_UI.c
Julian Elischer 589f6ed8ce Divorce the kernel binary ABI version number from the message
format version number. (userland programs should not need to be
recompiled when the netgraph kernel internal ABI is changed.

Also fix modules that don;t handle the fact that a caller may not supply
a return message pointer. (benign at the moment because the calling code
checks, but that will change)
2000-12-18 20:03:32 +00:00

253 lines
6.3 KiB
C

/*
* 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_rmnode;
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_rmnode,
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 *nodep)
{
priv_p priv;
int error;
/* Allocate private structure */
MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
if (priv == NULL)
return (ENOMEM);
/* Call generic node constructor */
if ((error = ng_make_node_common(&typestruct, nodep))) {
FREE(priv, M_NETGRAPH);
return (error);
}
(*nodep)->private = priv;
/* Done */
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 = node->private;
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, struct ng_mesg *msg,
const char *raddr, struct ng_mesg **rp, hook_p lasthook)
{
const priv_p priv = node->private;
if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) {
if (lasthook == priv->downlink) {
if (priv->uplink) {
return (ng_send_msg(node, msg, NULL,
priv->uplink, raddr, rp));
}
} else {
if (priv->downlink) {
return (ng_send_msg(node, msg, NULL,
priv->downlink, raddr, rp));
}
}
}
FREE(msg, M_NETGRAPH);
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, struct mbuf *m, meta_p meta,
struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp)
{
const node_p node = hook->node;
const priv_p priv = node->private;
int error = 0;
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_SEND_DATA(error, priv->uplink, m, meta); /* 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_SEND_DATA(error, priv->downlink, m, meta); /* m -> NULL */
} else
panic(__FUNCTION__);
done:
NG_FREE_DATA(m, meta); /* does nothing if m == NULL */
return (error);
}
/*
* Shutdown node
*/
static int
ng_UI_rmnode(node_p node)
{
const priv_p priv = node->private;
/* Take down netgraph node */
node->flags |= NG_INVALID;
ng_cutlinks(node);
ng_unname(node);
bzero(priv, sizeof(*priv));
FREE(priv, M_NETGRAPH);
node->private = NULL;
ng_unref(node);
return (0);
}
/*
* Hook disconnection
*/
static int
ng_UI_disconnect(hook_p hook)
{
const priv_p priv = hook->node->private;
if (hook->node->numhooks == 0)
ng_rmnode(hook->node);
else if (hook == priv->downlink)
priv->downlink = NULL;
else if (hook == priv->uplink)
priv->uplink = NULL;
else
panic(__FUNCTION__);
return (0);
}