From 0f75b09c798ed00c30d7d5551b896be883bc2aeb Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@nwl.cc>
Date: Fri, 2 Aug 2013 11:37:39 +0200
Subject: [PATCH] af_packet: when sending ethernet frames, parse header for
skb->protocol
This may be necessary when the SKB is passed to other layers on the go,
which check the protocol field on their own. An example is a VLAN packet
sent out using AF_PACKET on a bridge interface. The bridging code checks
the SKB size, accounting for any VLAN header only if the protocol field
is set accordingly.
Note that eth_type_trans() sets skb->dev to the passed argument, so this
can be skipped in packet_snd() for ethernet frames, as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/packet/af_packet.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 4cb28a7f639bc..71db35ecba394 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -88,6 +88,7 @@
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
+#include <linux/if_arp.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -2005,6 +2006,9 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
if (unlikely(err))
return err;
+ if (dev->type == ARPHRD_ETHER)
+ skb->protocol = eth_type_trans(skb, dev);
+
data += dev->hard_header_len;
to_write -= dev->hard_header_len;
}
@@ -2324,6 +2328,13 @@ static int packet_snd(struct socket *sock,
sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
+ if (dev->type == ARPHRD_ETHER) {
+ skb->protocol = eth_type_trans(skb, dev);
+ } else {
+ skb->protocol = proto;
+ skb->dev = dev;
+ }
+
if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
/* Earlier code assumed this would be a VLAN pkt,
* double-check this now that we have the actual
@@ -2338,8 +2349,6 @@ static int packet_snd(struct socket *sock,
}
}
- skb->protocol = proto;
- skb->dev = dev;
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
--
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