diff options
Diffstat (limited to 'net/802')
| -rw-r--r-- | net/802/Kconfig | 3 | ||||
| -rw-r--r-- | net/802/Makefile | 1 | ||||
| -rw-r--r-- | net/802/stp.c | 102 |
3 files changed, 106 insertions, 0 deletions
diff --git a/net/802/Kconfig b/net/802/Kconfig new file mode 100644 index 000000000000..01cb0943626b --- /dev/null +++ b/net/802/Kconfig @@ -0,0 +1,3 @@ +config STP + tristate + select LLC diff --git a/net/802/Makefile b/net/802/Makefile index 68569ffddea1..c441d895ac25 100644 --- a/net/802/Makefile +++ b/net/802/Makefile @@ -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 diff --git a/net/802/stp.c b/net/802/stp.c new file mode 100644 index 000000000000..0b7a24452d11 --- /dev/null +++ b/net/802/stp.c @@ -0,0 +1,102 @@ +/* + * 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"); |