Commit ccd4eb49 authored Jul 13, 2017 by Iván Briano Committed by David S. Miller Jul 14, 2017

net/packet: Fix Tx queue selection for AF_PACKET



When PACKET_QDISC_BYPASS is not used, Tx queue selection will be done
before the packet is enqueued, taking into account any mappings set by
a queuing discipline such as mqprio without hardware offloading. This
selection may be affected by a previously saved queue_mapping, either on
the Rx path, or done before the packet reaches the device, as it's
currently the case for AF_PACKET.

In order for queue selection to work as expected when using traffic
control, there can't be another selection done before that point is
reached, so move the call to packet_pick_tx_queue to
packet_direct_xmit, leaving the default xmit path as it was before
PACKET_QDISC_BYPASS was introduced.

A forward declaration of packet_pick_tx_queue() is introduced to avoid
the need to reorder the functions within the file.

Fixes: d346a3fa ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Iván Briano <ivan.briano@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 31a4562d

net/packet/af_packet.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -214,6 +214,7 @@ static void prb_clear_rxhash(struct tpacket_kbdq_core *,
		static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
		struct tpacket3_hdr *);
		static void packet_flush_mclist(struct sock *sk);
		static void packet_pick_tx_queue(struct net_device dev, struct sk_buff skb);

		struct packet_skb_cb {
		union {
		@@ -260,6 +261,7 @@ static int packet_direct_xmit(struct sk_buff *skb)
		if (skb != orig_skb)
		goto drop;

		packet_pick_tx_queue(dev, skb);
		txq = skb_get_tx_queue(dev, skb);

		local_bh_disable();
		@@ -2747,8 +2749,6 @@ tpacket_error:
		goto tpacket_error;
		}

		packet_pick_tx_queue(dev, skb);

		skb->destructor = tpacket_destruct_skb;
		__packet_set_status(po, ph, TP_STATUS_SENDING);
		packet_inc_pending(&po->tx_ring);
		@@ -2931,8 +2931,6 @@ static int packet_snd(struct socket sock, struct msghdr msg, size_t len)
		skb->priority = sk->sk_priority;
		skb->mark = sockc.mark;

		packet_pick_tx_queue(dev, skb);

		if (po->has_vnet_hdr) {
		err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
		if (err)

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