projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| a19800d7 PM |
1 | /* |
| 2 | * STP SAP demux | |
| 3 | * | |
| 4 | * Copyright (c) 2008 Patrick McHardy <[email protected]> | |
| 5 | * | |
| 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. | |
| 9 | */ | |
| 10 | #include <linux/mutex.h> | |
| 11 | #include <linux/skbuff.h> | |
| 12 | #include <linux/etherdevice.h> | |
| 13 | #include <linux/llc.h> | |
| 5a0e3ad6 | 14 | #include <linux/slab.h> |
| 3a9a231d | 15 | #include <linux/module.h> |
| a19800d7 PM |
16 | #include <net/llc.h> |
| 17 | #include <net/llc_pdu.h> | |
| 18 | #include <net/stp.h> | |
| 19 | ||
| 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) | |
| 24 | ||
| 3cc77ec7 ED |
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; | |
| a19800d7 PM |
27 | |
| 28 | static struct llc_sap *sap __read_mostly; | |
| 29 | static unsigned int sap_registered; | |
| 30 | static DEFINE_MUTEX(stp_proto_mutex); | |
| 31 | ||
| 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) | |
| 35 | { | |
| 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; | |
| 39 | ||
| 40 | if (pdu->ssap != LLC_SAP_BSPAN || | |
| 41 | pdu->dsap != LLC_SAP_BSPAN || | |
| 42 | pdu->ctrl_1 != LLC_PDU_TYPE_U) | |
| 43 | goto err; | |
| 44 | ||
| 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] - | |
| 47 | GARP_ADDR_MIN]); | |
| 48 | if (proto && | |
| 28b29801 | 49 | !ether_addr_equal(eh->h_dest, proto->group_address)) |
| a19800d7 PM |
50 | goto err; |
| 51 | } else | |
| 52 | proto = rcu_dereference(stp_proto); | |
| 53 | ||
| 54 | if (!proto) | |
| 55 | goto err; | |
| 56 | ||
| 57 | proto->rcv(proto, skb, dev); | |
| 58 | return 0; | |
| 59 | ||
| 60 | err: | |
| 61 | kfree_skb(skb); | |
| 62 | return 0; | |
| 63 | } | |
| 64 | ||
| 65 | int stp_proto_register(const struct stp_proto *proto) | |
| 66 | { | |
| 67 | int err = 0; | |
| 68 | ||
| 69 | mutex_lock(&stp_proto_mutex); | |
| 70 | if (sap_registered++ == 0) { | |
| 71 | sap = llc_sap_open(LLC_SAP_BSPAN, stp_pdu_rcv); | |
| 72 | if (!sap) { | |
| 73 | err = -ENOMEM; | |
| 74 | goto out; | |
| 75 | } | |
| 76 | } | |
| 77 | if (is_zero_ether_addr(proto->group_address)) | |
| 78 | rcu_assign_pointer(stp_proto, proto); | |
| 79 | else | |
| 80 | rcu_assign_pointer(garp_protos[proto->group_address[5] - | |
| 81 | GARP_ADDR_MIN], proto); | |
| 82 | out: | |
| 83 | mutex_unlock(&stp_proto_mutex); | |
| 84 | return err; | |
| 85 | } | |
| 86 | EXPORT_SYMBOL_GPL(stp_proto_register); | |
| 87 | ||
| 88 | void stp_proto_unregister(const struct stp_proto *proto) | |
| 89 | { | |
| 90 | mutex_lock(&stp_proto_mutex); | |
| 91 | if (is_zero_ether_addr(proto->group_address)) | |
| a9b3cd7f | 92 | RCU_INIT_POINTER(stp_proto, NULL); |
| a19800d7 | 93 | else |
| a9b3cd7f | 94 | RCU_INIT_POINTER(garp_protos[proto->group_address[5] - |
| a19800d7 PM |
95 | GARP_ADDR_MIN], NULL); |
| 96 | synchronize_rcu(); | |
| 97 | ||
| 98 | if (--sap_registered == 0) | |
| 99 | llc_sap_put(sap); | |
| 100 | mutex_unlock(&stp_proto_mutex); | |
| 101 | } | |
| 102 | EXPORT_SYMBOL_GPL(stp_proto_unregister); | |
| 103 | ||
| 104 | MODULE_LICENSE("GPL"); |