Commit a19800d7 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller

net: Add STP demux layer

Add small STP demux layer for demuxing STP PDUs based on MAC address.
This is needed to run both GARP and STP in parallel (or even load the
modules) since both use LLC_SAP_BSPAN.
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ef28d1a2
#ifndef _NET_STP_H
#define _NET_STP_H
struct stp_proto {
unsigned char group_address[ETH_ALEN];
void (*rcv)(const struct stp_proto *, struct sk_buff *,
struct net_device *);
void *data;
};
extern int stp_proto_register(const struct stp_proto *proto);
extern void stp_proto_unregister(const struct stp_proto *proto);
#endif /* _NET_STP_H */
config STP
tristate
select LLC
......@@ -10,3 +10,4 @@ obj-$(CONFIG_FDDI) += fddi.o
obj-$(CONFIG_HIPPI) += hippi.o
obj-$(CONFIG_IPX) += p8022.o psnap.o p8023.o
obj-$(CONFIG_ATALK) += p8022.o psnap.o
obj-$(CONFIG_STP) += stp.o
/*
* STP SAP demux
*
* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#include <linux/mutex.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/llc.h>
#include <net/llc.h>
#include <net/llc_pdu.h>
#include <net/stp.h>
/* 01:80:c2:00:00:20 - 01:80:c2:00:00:2F */
#define GARP_ADDR_MIN 0x20
#define GARP_ADDR_MAX 0x2F
#define GARP_ADDR_RANGE (GARP_ADDR_MAX - GARP_ADDR_MIN)
static const struct stp_proto *garp_protos[GARP_ADDR_RANGE + 1] __read_mostly;
static const struct stp_proto *stp_proto __read_mostly;
static struct llc_sap *sap __read_mostly;
static unsigned int sap_registered;
static DEFINE_MUTEX(stp_proto_mutex);
/* Called under rcu_read_lock from LLC */
static int stp_pdu_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
const struct ethhdr *eh = eth_hdr(skb);
const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
const struct stp_proto *proto;
if (pdu->ssap != LLC_SAP_BSPAN ||
pdu->dsap != LLC_SAP_BSPAN ||
pdu->ctrl_1 != LLC_PDU_TYPE_U)
goto err;
if (eh->h_dest[5] >= GARP_ADDR_MIN && eh->h_dest[5] <= GARP_ADDR_MAX) {
proto = rcu_dereference(garp_protos[eh->h_dest[5] -
GARP_ADDR_MIN]);
if (proto &&
compare_ether_addr(eh->h_dest, proto->group_address))
goto err;
} else
proto = rcu_dereference(stp_proto);
if (!proto)
goto err;
proto->rcv(proto, skb, dev);
return 0;
err:
kfree_skb(skb);
return 0;
}
int stp_proto_register(const struct stp_proto *proto)
{
int err = 0;
mutex_lock(&stp_proto_mutex);
if (sap_registered++ == 0) {
sap = llc_sap_open(LLC_SAP_BSPAN, stp_pdu_rcv);
if (!sap) {
err = -ENOMEM;
goto out;
}
}
if (is_zero_ether_addr(proto->group_address))
rcu_assign_pointer(stp_proto, proto);
else
rcu_assign_pointer(garp_protos[proto->group_address[5] -
GARP_ADDR_MIN], proto);
out:
mutex_unlock(&stp_proto_mutex);
return err;
}
EXPORT_SYMBOL_GPL(stp_proto_register);
void stp_proto_unregister(const struct stp_proto *proto)
{
mutex_lock(&stp_proto_mutex);
if (is_zero_ether_addr(proto->group_address))
rcu_assign_pointer(stp_proto, NULL);
else
rcu_assign_pointer(garp_protos[proto->group_address[5] -
GARP_ADDR_MIN], NULL);
synchronize_rcu();
if (--sap_registered == 0)
llc_sap_put(sap);
mutex_unlock(&stp_proto_mutex);
}
EXPORT_SYMBOL_GPL(stp_proto_unregister);
MODULE_LICENSE("GPL");
......@@ -181,6 +181,7 @@ source "net/dccp/Kconfig"
source "net/sctp/Kconfig"
source "net/tipc/Kconfig"
source "net/atm/Kconfig"
source "net/802/Kconfig"
source "net/bridge/Kconfig"
source "net/8021q/Kconfig"
source "net/decnet/Kconfig"
......
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