[PATCH v2 1/3] af_packet: when sending ethernet frames, parse header for skb->protocol
From: Phil Sutter <phil@nwl.cc>
Date: 2013-08-02 09:38:08
Subsystem:
networking [general], packet sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Willem de Bruijn, Linus Torvalds
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> --- Changes since V1: - minor lingual review of the comment - added note about setting skb->dev for non-ethernet frames only --- 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 20a1bd0..e549e17 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;
--
1.8.1.5