* [PATCH 2/2 v2] network: Allow af_packet to transmit +4 bytes for VLAN packets.
@ 2011-02-11 19:35 greearb
2011-02-11 22:18 ` Eric Dumazet
0 siblings, 1 reply; 3+ messages in thread
From: greearb @ 2011-02-11 19:35 UTC (permalink / raw)
To: netdev; +Cc: Ben Greear
From: Ben Greear <greearb@candelatech.com>
This allows user-space to send a '1500' MTU VLAN packet on a
1500 MTU ethernet frame. The extra 4 bytes of a VLAN header is
not usually charged against the MTU when other parts of the
network stack is transmitting vlans...
Signed-off-by: Ben Greear <greearb@candelatech.com>
---
v2: Fix ETH_HLEN to be VLAN_HLEN
:100644 100644 91cb1d7... eb39d70... M net/packet/af_packet.c
net/packet/af_packet.c | 31 +++++++++++++++++++++++++++++--
1 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 91cb1d7..eb39d70 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -466,7 +466,7 @@ retry:
*/
err = -EMSGSIZE;
- if (len > dev->mtu + dev->hard_header_len)
+ if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN)
goto out_unlock;
if (!skb) {
@@ -497,6 +497,19 @@ retry:
goto retry;
}
+ if (len > (dev->mtu + dev->hard_header_len)) {
+ /* Earlier code assumed this would be a VLAN pkt,
+ * double-check this now that we have the actual
+ * packet in hand.
+ */
+ struct ethhdr *ehdr;
+ skb_reset_mac_header(skb);
+ ehdr = eth_hdr(skb);
+ if (ehdr->h_proto != htons(ETH_P_8021Q)) {
+ err = -EMSGSIZE;
+ goto out_unlock;
+ }
+ }
skb->protocol = proto;
skb->dev = dev;
@@ -1200,7 +1213,7 @@ static int packet_snd(struct socket *sock,
}
err = -EMSGSIZE;
- if (!gso_type && (len > dev->mtu+reserve))
+ if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN))
goto out_unlock;
err = -ENOBUFS;
@@ -1225,6 +1238,20 @@ static int packet_snd(struct socket *sock,
if (err < 0)
goto out_free;
+ if (!gso_type && (len > dev->mtu + reserve)) {
+ /* Earlier code assumed this would be a VLAN pkt,
+ * double-check this now that we have the actual
+ * packet in hand.
+ */
+ struct ethhdr *ehdr;
+ skb_reset_mac_header(skb);
+ ehdr = eth_hdr(skb);
+ if (ehdr->h_proto != htons(ETH_P_8021Q)) {
+ err = -EMSGSIZE;
+ goto out_free;
+ }
+ }
+
skb->protocol = proto;
skb->dev = dev;
skb->priority = sk->sk_priority;
--
1.7.2.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2 v2] network: Allow af_packet to transmit +4 bytes for VLAN packets.
2011-02-11 19:35 [PATCH 2/2 v2] network: Allow af_packet to transmit +4 bytes for VLAN packets greearb
@ 2011-02-11 22:18 ` Eric Dumazet
2011-02-12 5:26 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2011-02-11 22:18 UTC (permalink / raw)
To: greearb; +Cc: netdev
Le vendredi 11 février 2011 à 11:35 -0800, greearb@candelatech.com a
écrit :
> From: Ben Greear <greearb@candelatech.com>
>
> This allows user-space to send a '1500' MTU VLAN packet on a
> 1500 MTU ethernet frame. The extra 4 bytes of a VLAN header is
> not usually charged against the MTU when other parts of the
> network stack is transmitting vlans...
>
> Signed-off-by: Ben Greear <greearb@candelatech.com>
> ---
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2 v2] network: Allow af_packet to transmit +4 bytes for VLAN packets.
2011-02-11 22:18 ` Eric Dumazet
@ 2011-02-12 5:26 ` David Miller
0 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2011-02-12 5:26 UTC (permalink / raw)
To: eric.dumazet; +Cc: greearb, netdev
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 11 Feb 2011 23:18:38 +0100
> Le vendredi 11 février 2011 à 11:35 -0800, greearb@candelatech.com a
> écrit :
>> From: Ben Greear <greearb@candelatech.com>
>>
>> This allows user-space to send a '1500' MTU VLAN packet on a
>> 1500 MTU ethernet frame. The extra 4 bytes of a VLAN header is
>> not usually charged against the MTU when other parts of the
>> network stack is transmitting vlans...
>>
>> Signed-off-by: Ben Greear <greearb@candelatech.com>
>> ---
>
> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Applied to net-next-2.6, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-02-11 19:35 [PATCH 2/2 v2] network: Allow af_packet to transmit +4 bytes for VLAN packets greearb
2011-02-11 22:18 ` Eric Dumazet
2011-02-12 5:26 ` David Miller
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