From 12464bb8de021a01fa7ec9299c273c247df7f198 Mon Sep 17 00:00:00 2001 From: Toshiaki Makita Date: Thu, 27 Mar 2014 21:46:55 +0900 Subject: bridge: Fix inabillity to retrieve vlan tags when tx offload is disabled Bridge vlan code (br_vlan_get_tag()) assumes that all frames have vlan_tci if they are tagged, but if vlan tx offload is manually disabled on bridge device and frames are sent from vlan device on the bridge device, the tags are embedded in skb->data and they break this assumption. Extract embedded vlan tags and move them to vlan_tci at ingress. Signed-off-by: Toshiaki Makita Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/bridge/br_vlan.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'net/bridge/br_vlan.c') diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index 8249ca76..44f31af 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -174,6 +174,18 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v, if (!v) return false; + /* If vlan tx offload is disabled on bridge device and frame was + * sent from vlan device on the bridge device, it does not have + * HW accelerated vlan tag. + */ + if (unlikely(!vlan_tx_tag_present(skb) && + (skb->protocol == htons(ETH_P_8021Q) || + skb->protocol == htons(ETH_P_8021AD)))) { + skb = vlan_untag(skb); + if (unlikely(!skb)) + return false; + } + err = br_vlan_get_tag(skb, vid); if (!*vid) { u16 pvid = br_get_pvid(v); -- cgit v1.1 From 99b192da9c99284ad3374132e56f66995cadc6b4 Mon Sep 17 00:00:00 2001 From: Toshiaki Makita Date: Thu, 27 Mar 2014 21:46:56 +0900 Subject: bridge: Fix handling stacked vlan tags If a bridge with vlan_filtering enabled receives frames with stacked vlan tags, i.e., they have two vlan tags, br_vlan_untag() strips not only the outer tag but also the inner tag. br_vlan_untag() is called only from br_handle_vlan(), and in this case, it is enough to set skb->vlan_tci to 0 here, because vlan_tci has already been set before calling br_handle_vlan(). Signed-off-by: Toshiaki Makita Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/bridge/br_vlan.c | 18 +----------------- 1 file changed, 1 insertion(+), 17 deletions(-) (limited to 'net/bridge/br_vlan.c') diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index 44f31af..c77eed5 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -119,22 +119,6 @@ static void __vlan_flush(struct net_port_vlans *v) kfree_rcu(v, rcu); } -/* Strip the tag from the packet. Will return skb with tci set 0. */ -static struct sk_buff *br_vlan_untag(struct sk_buff *skb) -{ - if (skb->protocol != htons(ETH_P_8021Q)) { - skb->vlan_tci = 0; - return skb; - } - - skb->vlan_tci = 0; - skb = vlan_untag(skb); - if (skb) - skb->vlan_tci = 0; - - return skb; -} - struct sk_buff *br_handle_vlan(struct net_bridge *br, const struct net_port_vlans *pv, struct sk_buff *skb) @@ -150,7 +134,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br, */ br_vlan_get_tag(skb, &vid); if (test_bit(vid, pv->untagged_bitmap)) - skb = br_vlan_untag(skb); + skb->vlan_tci = 0; out: return skb; -- cgit v1.1 From fc92f745f8d0d3736ce5afb00a905d7cc61f9c46 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Thu, 27 Mar 2014 21:51:18 -0400 Subject: bridge: Fix crash with vlan filtering and tcpdump When the vlan filtering is enabled on the bridge, but the filter is not configured on the bridge device itself, running tcpdump on the bridge device will result in a an Oops with NULL pointer dereference. The reason is that br_pass_frame_up() will bypass the vlan check because promisc flag is set. It will then try to get the table pointer and process the packet based on the table. Since the table pointer is NULL, we oops. Catch this special condition in br_handle_vlan(). Reported-by: Toshiaki Makita CC: Toshiaki Makita Signed-off-by: Vlad Yasevich Acked-by: Toshiaki Makita Signed-off-by: David S. Miller --- net/bridge/br_vlan.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'net/bridge/br_vlan.c') diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index c77eed5..f23c74b 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -128,6 +128,20 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br, if (!br->vlan_enabled) goto out; + /* Vlan filter table must be configured at this point. The + * only exception is the bridge is set in promisc mode and the + * packet is destined for the bridge device. In this case + * pass the packet as is. + */ + if (!pv) { + if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) { + goto out; + } else { + kfree_skb(skb); + return NULL; + } + } + /* At this point, we know that the frame was filtered and contains * a valid vlan id. If the vlan id is set in the untagged bitmap, * send untagged; otherwise, send tagged. -- cgit v1.1