4 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
10 #include <linux/mutex.h>
11 #include <linux/skbuff.h>
12 #include <linux/etherdevice.h>
13 #include <linux/llc.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
17 #include <net/llc_pdu.h>
20 /* 01:80:c2:00:00:20 - 01:80:c2:00:00:2F */
21 #define GARP_ADDR_MIN 0x20
22 #define GARP_ADDR_MAX 0x2F
23 #define GARP_ADDR_RANGE (GARP_ADDR_MAX - GARP_ADDR_MIN)
25 static const struct stp_proto __rcu
*garp_protos
[GARP_ADDR_RANGE
+ 1] __read_mostly
;
26 static const struct stp_proto __rcu
*stp_proto __read_mostly
;
28 static struct llc_sap
*sap __read_mostly
;
29 static unsigned int sap_registered
;
30 static DEFINE_MUTEX(stp_proto_mutex
);
32 /* Called under rcu_read_lock from LLC */
33 static int stp_pdu_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
34 struct packet_type
*pt
, struct net_device
*orig_dev
)
36 const struct ethhdr
*eh
= eth_hdr(skb
);
37 const struct llc_pdu_un
*pdu
= llc_pdu_un_hdr(skb
);
38 const struct stp_proto
*proto
;
40 if (pdu
->ssap
!= LLC_SAP_BSPAN
||
41 pdu
->dsap
!= LLC_SAP_BSPAN
||
42 pdu
->ctrl_1
!= LLC_PDU_TYPE_U
)
45 if (eh
->h_dest
[5] >= GARP_ADDR_MIN
&& eh
->h_dest
[5] <= GARP_ADDR_MAX
) {
46 proto
= rcu_dereference(garp_protos
[eh
->h_dest
[5] -
49 !ether_addr_equal(eh
->h_dest
, proto
->group_address
))
52 proto
= rcu_dereference(stp_proto
);
57 proto
->rcv(proto
, skb
, dev
);
65 int stp_proto_register(const struct stp_proto
*proto
)
69 mutex_lock(&stp_proto_mutex
);
70 if (sap_registered
++ == 0) {
71 sap
= llc_sap_open(LLC_SAP_BSPAN
, stp_pdu_rcv
);
77 if (is_zero_ether_addr(proto
->group_address
))
78 rcu_assign_pointer(stp_proto
, proto
);
80 rcu_assign_pointer(garp_protos
[proto
->group_address
[5] -
81 GARP_ADDR_MIN
], proto
);
83 mutex_unlock(&stp_proto_mutex
);
86 EXPORT_SYMBOL_GPL(stp_proto_register
);
88 void stp_proto_unregister(const struct stp_proto
*proto
)
90 mutex_lock(&stp_proto_mutex
);
91 if (is_zero_ether_addr(proto
->group_address
))
92 RCU_INIT_POINTER(stp_proto
, NULL
);
94 RCU_INIT_POINTER(garp_protos
[proto
->group_address
[5] -
95 GARP_ADDR_MIN
], NULL
);
98 if (--sap_registered
== 0)
100 mutex_unlock(&stp_proto_mutex
);
102 EXPORT_SYMBOL_GPL(stp_proto_unregister
);
104 MODULE_LICENSE("GPL");
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