From 1007dd1aa50b0403df370834f647abef1722925c Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Tue, 13 Nov 2012 07:53:08 +0000 Subject: bridge: add root port blocking This is Linux bridge implementation of root port guard. If BPDU is received from a leaf (edge) port, it should not be elected as root port. Why would you want to do this? If using STP on a bridge and the downstream bridges are not fully trusted; this prevents a hostile guest for rerouting traffic. Why not just use netfilter? Netfilter does not track of follow spanning tree decisions. It would be difficult and error prone to try and mirror STP resolution in netfilter module. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/br_netlink.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/bridge/br_netlink.c') diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index c331e28c7880..65429b99a2a3 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -27,6 +27,7 @@ static inline size_t br_port_info_size(void) + nla_total_size(4) /* IFLA_BRPORT_COST */ + nla_total_size(1) /* IFLA_BRPORT_MODE */ + nla_total_size(1) /* IFLA_BRPORT_GUARD */ + + nla_total_size(1) /* IFLA_BRPORT_PROTECT */ + 0; } @@ -51,7 +52,8 @@ static int br_port_fill_attrs(struct sk_buff *skb, 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_GUARD, !!(p->flags & BR_BPDU_GUARD))) + nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) || + nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK))) return -EMSGSIZE; return 0; @@ -165,6 +167,7 @@ static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = { [IFLA_BRPORT_PRIORITY] = { .type = NLA_U16 }, [IFLA_BRPORT_MODE] = { .type = NLA_U8 }, [IFLA_BRPORT_GUARD] = { .type = NLA_U8 }, + [IFLA_BRPORT_PROTECT] = { .type = NLA_U8 }, }; /* Change the state of the port and notify spanning tree */ -- cgit v1.2.1