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authorstephen hemminger <shemminger@vyatta.com>2012-11-13 07:53:07 (GMT)
committerDavid S. Miller <davem@davemloft.net>2012-11-15 01:20:44 (GMT)
commita2e01a65cd7135dab26d27d4b589b2e5358bec99 (patch)
tree3b51f10fa3e17cb734daba83b94d7466ac348a67 /net
parentcd7537326e617e71b5a84b205b755bc86bee8d06 (diff)
downloadlinux-a2e01a65cd7135dab26d27d4b589b2e5358bec99.tar.xz
bridge: implement BPDU blocking
This is Linux bridge implementation of STP protection (Cisco BPDU guard/Juniper BPDU block). BPDU block disables the bridge port if a STP BPDU packet is received. Why would you want to do this? If running Spanning Tree on bridge, hostile devices on the network may send BPDU and cause network failure. Enabling bpdu block will detect and stop this. How to recover the port? The port will be restarted if link is brought down, or removed and reattached. For example: # ip li set dev eth0 down; ip li set dev eth0 up Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/bridge/br_netlink.c6
-rw-r--r--net/bridge/br_private.h1
-rw-r--r--net/bridge/br_stp_bpdu.c7
-rw-r--r--net/bridge/br_sysfs_if.c2
4 files changed, 15 insertions, 1 deletions
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 0188a2f..c331e28 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -26,6 +26,7 @@ static inline size_t br_port_info_size(void)
+ nla_total_size(2) /* IFLA_BRPORT_PRIORITY */
+ nla_total_size(4) /* IFLA_BRPORT_COST */
+ nla_total_size(1) /* IFLA_BRPORT_MODE */
+ + nla_total_size(1) /* IFLA_BRPORT_GUARD */
+ 0;
}
@@ -49,7 +50,8 @@ static int br_port_fill_attrs(struct sk_buff *skb,
if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
- nla_put_u8(skb, IFLA_BRPORT_MODE, mode))
+ nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
+ nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)))
return -EMSGSIZE;
return 0;
@@ -162,6 +164,7 @@ static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
[IFLA_BRPORT_COST] = { .type = NLA_U32 },
[IFLA_BRPORT_PRIORITY] = { .type = NLA_U16 },
[IFLA_BRPORT_MODE] = { .type = NLA_U8 },
+ [IFLA_BRPORT_GUARD] = { .type = NLA_U8 },
};
/* Change the state of the port and notify spanning tree */
@@ -203,6 +206,7 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
int err;
br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
+ br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
if (tb[IFLA_BRPORT_COST]) {
err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 22111ff..c92b080 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -135,6 +135,7 @@ struct net_bridge_port
unsigned long flags;
#define BR_HAIRPIN_MODE 0x00000001
+#define BR_BPDU_GUARD 0x00000002
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
u32 multicast_startup_queries_sent;
diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index fd30a60..7f884e3 100644
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -170,6 +170,13 @@ void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
if (!ether_addr_equal(dest, br->group_addr))
goto out;
+ if (p->flags & BR_BPDU_GUARD) {
+ br_notice(br, "BPDU received on blocked port %u(%s)\n",
+ (unsigned int) p->port_no, p->dev->name);
+ br_stp_disable_port(p);
+ goto out;
+ }
+
buf = skb_pull(skb, 3);
if (buf[0] == BPDU_TYPE_CONFIG) {
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index f26173d3..d1dfa40 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c
@@ -156,6 +156,7 @@ static int store_flush(struct net_bridge_port *p, unsigned long v)
static BRPORT_ATTR(flush, S_IWUSR, NULL, store_flush);
BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE);
+BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD);
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
@@ -189,6 +190,7 @@ static const struct brport_attribute *brport_attrs[] = {
&brport_attr_hold_timer,
&brport_attr_flush,
&brport_attr_hairpin_mode,
+ &brport_attr_bpdu_guard,
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
&brport_attr_multicast_router,
#endif