| Message ID | 1374157166.6097.28.camel@edumazet-glaptop |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2013-07-18 at 07:19 -0700, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > In commit 48cc32d38a52d0b68f91a171a8d00531edc6a46e > ("vlan: don't deliver frames for unknown vlans to protocols") > Florian made sure we set pkt_type to PACKET_OTHERHOST > if the vlan id is set and we could find a vlan device for this > particular id. > > But we also have a problem if prio bits are set. > > Steinar reported an issue on a router receiving IPv6 frames with a > vlan tag of 4000 (id 0, prio 2), and tunneled into a sit device, > because skb->vlan_tci is set. > > Forwarded frame is completely corrupted : We can see (8100:4000) > being inserted in the middle of IPv6 source address : > > 16:48:00.780413 IP6 2001:16d8:8100:4000:ee1c:0:9d9:bc87 > > 9f94:4d95:2001:67c:29f4::: ICMP6, unknown icmp6 type (0), length 64 > 0x0000: 0000 0029 8000 c7c3 7103 0001 a0ae e651 > 0x0010: 0000 0000 ccce 0b00 0000 0000 1011 1213 > 0x0020: 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223 > 0x0030: 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233 > > It seems we are not really ready to properly cope with this right now. > > We can probably do better in future kernels : > vlan_get_ingress_priority() should be a netdev property instead of > a per vlan_dev one. > > For stable kernels, lets clear vlan_tci to fix the bugs. > > Reported-by: Steinar H. Gunderson <sesse@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > --- While looking at the 'future' patches for net-next, I found that vlan_dev_get_egress_qos_mask() uses no protection at all while doing the lookup in hash table. This is racy with concurrent insert/deletes, eventually. This probably needs a bit of RCU care ;) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Thu, 18 Jul 2013 07:19:26 -0700 > From: Eric Dumazet <edumazet@google.com> > > In commit 48cc32d38a52d0b68f91a171a8d00531edc6a46e > ("vlan: don't deliver frames for unknown vlans to protocols") > Florian made sure we set pkt_type to PACKET_OTHERHOST > if the vlan id is set and we could find a vlan device for this > particular id. > > But we also have a problem if prio bits are set. > > Steinar reported an issue on a router receiving IPv6 frames with a > vlan tag of 4000 (id 0, prio 2), and tunneled into a sit device, > because skb->vlan_tci is set. > > Forwarded frame is completely corrupted : We can see (8100:4000) > being inserted in the middle of IPv6 source address : > > 16:48:00.780413 IP6 2001:16d8:8100:4000:ee1c:0:9d9:bc87 > > 9f94:4d95:2001:67c:29f4::: ICMP6, unknown icmp6 type (0), length 64 > 0x0000: 0000 0029 8000 c7c3 7103 0001 a0ae e651 > 0x0010: 0000 0000 ccce 0b00 0000 0000 1011 1213 > 0x0020: 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223 > 0x0030: 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233 > > It seems we are not really ready to properly cope with this right now. > > We can probably do better in future kernels : > vlan_get_ingress_priority() should be a netdev property instead of > a per vlan_dev one. > > For stable kernels, lets clear vlan_tci to fix the bugs. > > Reported-by: Steinar H. Gunderson <sesse@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> Applied and queued up for -stable, thanks Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index cdcbafa..715c343 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -79,9 +79,8 @@ 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) +#define vlan_tx_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK) #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 8a15eaa..4a78c4d 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -9,7 +9,7 @@ bool vlan_do_receive(struct sk_buff **skbp) { struct sk_buff *skb = *skbp; __be16 vlan_proto = skb->vlan_proto; - u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK; + u16 vlan_id = vlan_tx_tag_get_id(skb); struct net_device *vlan_dev; struct vlan_pcpu_stats *rx_stats; diff --git a/net/core/dev.c b/net/core/dev.c index a3d8d44..26755dd 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3580,8 +3580,15 @@ ncls: } } - if (vlan_tx_nonzero_tag_present(skb)) - skb->pkt_type = PACKET_OTHERHOST; + if (unlikely(vlan_tx_tag_present(skb))) { + if (vlan_tx_tag_get_id(skb)) + skb->pkt_type = PACKET_OTHERHOST; + /* Note: we might in the future use prio bits + * and set skb->priority like in vlan_do_receive() + * For the time being, just ignore Priority Code Point + */ + skb->vlan_tci = 0; + } /* deliver only exact match when indicated */ null_or_dev = deliver_exact ? skb->dev : NULL;