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Commit 0f75b09c authored by Phil Sutter's avatar Phil Sutter Committed by David S. Miller
Browse files

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: default avatarPhil Sutter <phil@nwl.cc>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d27fc782

net/packet/af_packet.c

+11 −2
Original line number Diff line number Diff line
@@ -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;