[PATCH 02/11] bridge: Validate that vlan is permitted on ingress
From: Vlad Yasevich <hidden>
Date: 2012-12-12 20:01:27
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
When a frame arrives on a port, if we have VLANs configured, validate that a given VLAN is allowed to ingress on a given port. Signed-off-by: Vlad Yasevich <redacted> --- net/bridge/br_input.c | 23 +++++++++++++++++++++++ net/bridge/br_private.h | 15 +++++++++++++-- 2 files changed, 36 insertions(+), 2 deletions(-)
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 4b34207..54c0894 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c@@ -17,6 +17,7 @@ #include <linux/etherdevice.h> #include <linux/netfilter_bridge.h> #include <linux/export.h> +#include <linux/rculist.h> #include "br_private.h" /* Hook for brouter */
@@ -41,6 +42,25 @@ static int br_pass_frame_up(struct sk_buff *skb) netif_receive_skb); } +static bool br_allowed_ingress(struct net_bridge_port *p, struct sk_buff *skb) +{ + struct net_port_vlan *pve; + u16 vid; + + /* If there are no vlan in the permitted list, all packets are + * permitted. + */ + if (list_empty(&p->vlan_list)) + return true; + + vid = br_get_vlan(skb); + pve = nbp_vlan_find(p, vid); + if (pve) + return true; + + return false; +} + /* note: already called with rcu_read_lock */ int br_handle_frame_finish(struct sk_buff *skb) {
@@ -54,6 +74,9 @@ int br_handle_frame_finish(struct sk_buff *skb) if (!p || p->state == BR_STATE_DISABLED) goto drop; + if (!br_allowed_ingress(p, skb)) + goto drop; + /* insert into forwarding database after filtering to avoid spoofing */ br = p->br; br_fdb_update(br, p, eth_hdr(skb)->h_source);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 1d9e6ce..5f05c16 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h@@ -66,8 +66,6 @@ struct br_ip }; #define BR_INVALID_VID (1<<15) -#define BR_UNTAGGED_VID (1<<14) - #define BR_VID_HASH_SIZE (1<<6) #define br_vlan_hash(vid) ((vid) % (BR_VID_HASH_SIZE - 1))
@@ -197,6 +195,19 @@ static inline struct net_bridge_port *br_port_get_rtnl(struct net_device *dev) rtnl_dereference(dev->rx_handler_data) : NULL; } +static inline u16 br_get_vlan(const struct sk_buff *skb) +{ + u16 tag; + + if (vlan_tx_tag_present(skb)) + return vlan_tx_tag_get(skb) & VLAN_VID_MASK; + + if (vlan_get_tag(skb, &tag)) + return 0; + + return tag & VLAN_VID_MASK; +} + struct br_cpu_netstats { u64 rx_packets; u64 rx_bytes;
--
1.7.7.6