freebsd-dev/sys/netgraph/ng_rfc1490.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

346 lines
9.4 KiB
C

/*
* ng_rfc1490.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_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
*/
/*
* This node does RFC 1490 multiplexing.
*
* NOTE: RFC 1490 is updated by RFC 2427.
*/
#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/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_rfc1490.h>
/*
* DEFINITIONS
*/
/* Q.922 stuff -- see RFC 1490 */
#define HDLC_UI 0x03
#define NLPID_IP 0xCC
#define NLPID_PPP 0xCF
#define NLPID_SNAP 0x80
#define NLPID_Q933 0x08
#define NLPID_CLNP 0x81
#define NLPID_ESIS 0x82
#define NLPID_ISIS 0x83
/* Node private data */
struct ng_rfc1490_private {
hook_p downlink;
hook_p ppp;
hook_p inet;
};
typedef struct ng_rfc1490_private *priv_p;
/* Netgraph node methods */
static ng_constructor_t ng_rfc1490_constructor;
static ng_rcvmsg_t ng_rfc1490_rcvmsg;
static ng_shutdown_t ng_rfc1490_rmnode;
static ng_newhook_t ng_rfc1490_newhook;
static ng_rcvdata_t ng_rfc1490_rcvdata;
static ng_disconnect_t ng_rfc1490_disconnect;
/* Node type descriptor */
static struct ng_type typestruct = {
NG_ABI_VERSION,
NG_RFC1490_NODE_TYPE,
NULL,
ng_rfc1490_constructor,
ng_rfc1490_rcvmsg,
ng_rfc1490_rmnode,
ng_rfc1490_newhook,
NULL,
NULL,
ng_rfc1490_rcvdata,
ng_rfc1490_disconnect,
NULL
};
NETGRAPH_INIT(rfc1490, &typestruct);
/************************************************************************
NETGRAPH NODE STUFF
************************************************************************/
/*
* Node constructor
*/
static int
ng_rfc1490_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_rfc1490_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = node->private;
if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
if (priv->downlink)
return (EISCONN);
priv->downlink = hook;
} else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
if (priv->ppp)
return (EISCONN);
priv->ppp = hook;
} else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
if (priv->inet)
return (EISCONN);
priv->inet = hook;
} else
return (EINVAL);
return (0);
}
/*
* Receive a control message. We don't support any special ones.
*/
static int
ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg,
const char *raddr, struct ng_mesg **rp, hook_p lasthook)
{
FREE(msg, M_NETGRAPH);
return (EINVAL);
}
/*
* Receive data on a hook and encapsulate according to RFC 1490.
* Only those nodes marked (*) are supported by this routine so far.
*
* Q.922 control
* |
* |
* --------------------------------------------
* | 0x03 |
* UI I Frame
* | |
* --------------------------------- --------------
* | 0x08 | 0x81 |0xCC |0xCF | 0x00 |..01.... |..10....
* | | | | | 0x80 | |
* Q.933 CLNP IP(*) PPP(*) SNAP ISO 8208 ISO 8208
* | (rfc1973) | Modulo 8 Modulo 128
* | |
* -------------------- OUI
* | | |
* L2 ID L3 ID -------------------------
* | User |00-80-C2 |00-00-00
* | specified | |
* | 0x70 PID Ethertype
* | | |
* ------------------- --------------... ----------
* |0x51 |0x4E | |0x4C |0x1 |0xB | |0x806 |
* | | | | | | | | |
* 7776 Q.922 Others 802.2 802.3 802.6 Others ARP(*) Others
*
*
*/
#define MAX_ENCAPS_HDR 8
#define ERROUT(x) do { error = (x); goto done; } while (0)
#define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
static int
ng_rfc1490_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);
/* Eat optional zero pad byte */
if (*ptr == 0x00)
ptr++;
/* Multiplex on NLPID */
switch (*ptr++) {
case NLPID_SNAP:
if (OUICMP(ptr, 0, 0, 0)) { /* It's an ethertype */
u_int16_t etype;
ptr += 3;
etype = ntohs(*((u_int16_t *) ptr));
ptr += 2;
m_adj(m, ptr - start);
switch (etype) {
case ETHERTYPE_IP:
NG_SEND_DATA(error,
priv->inet, m, meta);
break;
case ETHERTYPE_ARP:
case ETHERTYPE_REVARP:
default:
ERROUT(0);
}
} else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) /* 802.1 bridging */
ERROUT(0);
else /* Other weird stuff... */
ERROUT(0);
break;
case NLPID_IP:
m_adj(m, ptr - start);
NG_SEND_DATA(error, priv->inet, m, meta);
break;
case NLPID_PPP:
m_adj(m, ptr - start);
NG_SEND_DATA(error, priv->ppp, m, meta);
break;
case NLPID_Q933:
case NLPID_CLNP:
case NLPID_ESIS:
case NLPID_ISIS:
ERROUT(0);
default: /* Try PPP (see RFC 1973) */
ptr--; /* NLPID becomes PPP proto */
if ((*ptr & 0x01) == 0x01)
ERROUT(0);
m_adj(m, ptr - start);
NG_SEND_DATA(error, priv->ppp, m, meta);
break;
}
} else if (hook == priv->ppp) {
M_PREPEND(m, 2, M_DONTWAIT); /* Prepend PPP NLPID */
if (!m)
ERROUT(ENOBUFS);
mtod(m, u_char *)[0] = HDLC_UI;
mtod(m, u_char *)[1] = NLPID_PPP;
NG_SEND_DATA(error, priv->downlink, m, meta);
} else if (hook == priv->inet) {
M_PREPEND(m, 2, M_DONTWAIT); /* Prepend IP NLPID */
if (!m)
ERROUT(ENOBUFS);
mtod(m, u_char *)[0] = HDLC_UI;
mtod(m, u_char *)[1] = NLPID_IP;
NG_SEND_DATA(error, priv->downlink, m, meta);
} else
panic(__FUNCTION__);
done:
NG_FREE_DATA(m, meta);
return (error);
}
/*
* Nuke node
*/
static int
ng_rfc1490_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));
node->private = NULL;
ng_unref(node); /* let the node escape */
return (0);
}
/*
* Hook disconnection
*/
static int
ng_rfc1490_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->inet)
priv->inet = NULL;
else if (hook == priv->ppp)
priv->ppp = NULL;
else
panic(__FUNCTION__);
return (0);
}