]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - net/802/stp.c
1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
7 #include <linux/mutex.h>
8 #include <linux/skbuff.h>
9 #include <linux/etherdevice.h>
10 #include <linux/llc.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
14 #include <net/llc_pdu.h>
17 /* 01:80:c2:00:00:20 - 01:80:c2:00:00:2F */
18 #define GARP_ADDR_MIN 0x20
19 #define GARP_ADDR_MAX 0x2F
20 #define GARP_ADDR_RANGE (GARP_ADDR_MAX - GARP_ADDR_MIN)
22 static const struct stp_proto __rcu
*garp_protos
[GARP_ADDR_RANGE
+ 1] __read_mostly
;
23 static const struct stp_proto __rcu
*stp_proto __read_mostly
;
25 static struct llc_sap
*sap __read_mostly
;
26 static unsigned int sap_registered
;
27 static DEFINE_MUTEX(stp_proto_mutex
);
29 /* Called under rcu_read_lock from LLC */
30 static int stp_pdu_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
31 struct packet_type
*pt
, struct net_device
*orig_dev
)
33 const struct ethhdr
*eh
= eth_hdr(skb
);
34 const struct llc_pdu_un
*pdu
= llc_pdu_un_hdr(skb
);
35 const struct stp_proto
*proto
;
37 if (pdu
->ssap
!= LLC_SAP_BSPAN
||
38 pdu
->dsap
!= LLC_SAP_BSPAN
||
39 pdu
->ctrl_1
!= LLC_PDU_TYPE_U
)
42 if (eh
->h_dest
[5] >= GARP_ADDR_MIN
&& eh
->h_dest
[5] <= GARP_ADDR_MAX
) {
43 proto
= rcu_dereference(garp_protos
[eh
->h_dest
[5] -
46 !ether_addr_equal(eh
->h_dest
, proto
->group_address
))
49 proto
= rcu_dereference(stp_proto
);
54 proto
->rcv(proto
, skb
, dev
);
62 int stp_proto_register(const struct stp_proto
*proto
)
66 mutex_lock(&stp_proto_mutex
);
67 if (sap_registered
++ == 0) {
68 sap
= llc_sap_open(LLC_SAP_BSPAN
, stp_pdu_rcv
);
74 if (is_zero_ether_addr(proto
->group_address
))
75 rcu_assign_pointer(stp_proto
, proto
);
77 rcu_assign_pointer(garp_protos
[proto
->group_address
[5] -
78 GARP_ADDR_MIN
], proto
);
80 mutex_unlock(&stp_proto_mutex
);
83 EXPORT_SYMBOL_GPL(stp_proto_register
);
85 void stp_proto_unregister(const struct stp_proto
*proto
)
87 mutex_lock(&stp_proto_mutex
);
88 if (is_zero_ether_addr(proto
->group_address
))
89 RCU_INIT_POINTER(stp_proto
, NULL
);
91 RCU_INIT_POINTER(garp_protos
[proto
->group_address
[5] -
92 GARP_ADDR_MIN
], NULL
);
95 if (--sap_registered
== 0)
97 mutex_unlock(&stp_proto_mutex
);
99 EXPORT_SYMBOL_GPL(stp_proto_unregister
);
101 MODULE_LICENSE("GPL");