Release 4.11 net/802/stp.c

/*
 *      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 <linux/slab.h>
#include <linux/module.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 __rcu *garp_protos[GARP_ADDR_RANGE + 1] __read_mostly;

static const struct stp_proto __rcu *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 &&
		    !ether_addr_equal(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;
}

Contributors
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Patrick McHardy
173
98.86%
1
50.00%
Joe Perches
2
1.14%
1
50.00%
Total
175
100.00%
2
100.00%



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;
}
Contributors
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CommitProp
Patrick McHardy
100
100.00%
1
100.00%
Total
100
100.00%
1
100.00%


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_INIT_POINTER(stp_proto, NULL);
	else
		RCU_INIT_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);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick McHardy
70
97.22%
1
50.00%
Stephen Hemminger
2
2.78%
1
50.00%
Total
72
100.00%
2
100.00%


EXPORT_SYMBOL_GPL(stp_proto_unregister);

MODULE_LICENSE("GPL");
Overall Contributors
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Tokens
Prop
Commits
CommitProp
Patrick McHardy
433
97.30%
1
16.67%
Tejun Heo
3
0.67%
1
16.67%
Paul Gortmaker
3
0.67%
1
16.67%
Joe Perches
2
0.45%
1
16.67%
Stephen Hemminger
2
0.45%
1
16.67%
Eric Dumazet
2
0.45%
1
16.67%
Total
445
100.00%
6
100.00%
Directory: net/802

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