Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753071Ab2JHBwN (ORCPT ); Sun, 7 Oct 2012 21:52:13 -0400 Received: from rain.florz.de ([62.216.164.86]:43002 "EHLO rain.florz.dyndns.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750745Ab2JHBwL (ORCPT ); Sun, 7 Oct 2012 21:52:11 -0400 Date: Mon, 8 Oct 2012 03:51:58 +0200 From: Florian Zumbiehl To: Patrick McHardy , "David S. Miller" , eric.dumazet@gmail.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jpirko@redhat.com Subject: [PATCH v2] vlan: don't deliver frames for unknown vlans to protocols Message-ID: <20121008015158.GE25895@florz.florz.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5013 Lines: 136 6a32e4f9dd9219261f8856f817e6655114cfec2f made the vlan code skip marking vlan-tagged frames for not locally configured vlans as PACKET_OTHERHOST if there was an rx_handler, as the rx_handler could cause the frame to be received on a different (virtual) vlan-capable interface where that vlan might be configured. As rx_handlers do not necessarily return RX_HANDLER_ANOTHER, this could cause frames for unknown vlans to be delivered to the protocol stack as if they had been received untagged. For example, if an ipv6 router advertisement that's tagged for a locally not configured vlan is received on an interface with macvlan interfaces attached, macvlan's rx_handler returns RX_HANDLER_PASS after delivering the frame to the macvlan interfaces, which caused it to be passed to the protocol stack, leading to ipv6 addresses for the announced prefix being configured even though those are completely unusable on the underlying interface. The fix moves marking as PACKET_OTHERHOST after the rx_handler so the rx_handler, if there is one, sees the frame unchanged, but afterwards, before the frame is delivered to the protocol stack, it gets marked whether there is an rx_handler or not. Signed-off-by: Florian Zumbiehl --- NOTE: This was tested on 3.5.4, but massaged to apply on a recent stable head--in any case this should be carefully reviewed by someone who knows the code well, in case that wasn't obvious anyhow. This version completely avoids any new state that could need to be spilled to RAM, and instead re-checks existence and non-zeroness of the tag. What do you think? diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index a810987..561e130 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -82,6 +82,8 @@ static inline int is_vlan_dev(struct net_device *dev) } #define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT) +#define vlan_tx_nonzero_tag_present(__skb) \ + (vlan_tx_tag_present(__skb) && ((__skb)->vlan_tci & VLAN_VID_MASK)) #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) @@ -91,7 +93,7 @@ extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); extern u16 vlan_dev_vlan_id(const struct net_device *dev); -extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler); +extern bool vlan_do_receive(struct sk_buff **skb); extern struct sk_buff *vlan_untag(struct sk_buff *skb); extern int vlan_vid_add(struct net_device *dev, unsigned short vid); @@ -120,10 +122,8 @@ static inline u16 vlan_dev_vlan_id(const struct net_device *dev) return 0; } -static inline bool vlan_do_receive(struct sk_buff **skb, bool last_handler) +static inline bool vlan_do_receive(struct sk_buff **skb) { - if (((*skb)->vlan_tci & VLAN_VID_MASK) && last_handler) - (*skb)->pkt_type = PACKET_OTHERHOST; return false; } diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 8ca533c..f981d37 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -5,7 +5,7 @@ #include #include "vlan.h" -bool vlan_do_receive(struct sk_buff **skbp, bool last_handler) +bool vlan_do_receive(struct sk_buff **skbp) { struct sk_buff *skb = *skbp; u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK; @@ -13,14 +13,8 @@ bool vlan_do_receive(struct sk_buff **skbp, bool last_handler) struct vlan_pcpu_stats *rx_stats; vlan_dev = vlan_find_dev(skb->dev, vlan_id); - if (!vlan_dev) { - /* Only the last call to vlan_do_receive() should change - * pkt_type to PACKET_OTHERHOST - */ - if (vlan_id && last_handler) - skb->pkt_type = PACKET_OTHERHOST; + if (!vlan_dev) return false; - } skb = *skbp = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) diff --git a/net/core/dev.c b/net/core/dev.c index 8398836..c580708 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3273,18 +3273,18 @@ ncls: && !skb_pfmemalloc_protocol(skb)) goto drop; - rx_handler = rcu_dereference(skb->dev->rx_handler); if (vlan_tx_tag_present(skb)) { if (pt_prev) { ret = deliver_skb(skb, pt_prev, orig_dev); pt_prev = NULL; } - if (vlan_do_receive(&skb, !rx_handler)) + if (vlan_do_receive(&skb)) goto another_round; else if (unlikely(!skb)) goto unlock; } + rx_handler = rcu_dereference(skb->dev->rx_handler); if (rx_handler) { if (pt_prev) { ret = deliver_skb(skb, pt_prev, orig_dev); @@ -3304,6 +3304,9 @@ ncls: } } + if (vlan_tx_nonzero_tag_present(skb)) + skb->pkt_type = PACKET_OTHERHOST; + /* deliver only exact match when indicated */ null_or_dev = deliver_exact ? skb->dev : NULL; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/