On Mon, Sep 12, 2016 at 7:55 AM, <kan.li...@intel.com> wrote:
> From: Kan Liang <kan.li...@intel.com>
>
> When the device tries to transmit a packet, netdev_pick_tx is called to
> find the available tx queues. If the net policy is applied, it picks up
> the assigned tx queue from net policy subsystem, and redirect the
> traffic to the assigned queue.
>
> Signed-off-by: Kan Liang <kan.li...@intel.com>
> ---
> include/net/sock.h | 9 +++++++++
> net/core/dev.c | 20 ++++++++++++++++++--
> 2 files changed, 27 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index e1e9e3d..ca97f35 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -2280,4 +2280,13 @@ extern int sysctl_optmem_max;
> extern __u32 sysctl_wmem_default;
> extern __u32 sysctl_rmem_default;
>
> +/* Return netpolicy instance information from socket. */
> +static inline struct netpolicy_instance *netpolicy_find_instance(struct sock
> *sk)
> +{
> +#ifdef CONFIG_NETPOLICY
> + if (is_net_policy_valid(sk->sk_netpolicy.policy))
> + return &sk->sk_netpolicy;
> +#endif
> + return NULL;
> +}
> #endif /* _SOCK_H */
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 34b5322..b9a8044 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -3266,6 +3266,7 @@ struct netdev_queue *netdev_pick_tx(struct net_device
> *dev,
> struct sk_buff *skb,
> void *accel_priv)
> {
> + struct sock *sk = skb->sk;
> int queue_index = 0;
>
> #ifdef CONFIG_XPS
> @@ -3280,8 +3281,23 @@ struct netdev_queue *netdev_pick_tx(struct net_device
> *dev,
> if (ops->ndo_select_queue)
> queue_index = ops->ndo_select_queue(dev, skb,
> accel_priv,
> __netdev_pick_tx);
> - else
> - queue_index = __netdev_pick_tx(dev, skb);
> + else {
> +#ifdef CONFIG_NETPOLICY
> + struct netpolicy_instance *instance;
> +
> + queue_index = -1;
> + if (dev->netpolicy && sk) {
> + instance = netpolicy_find_instance(sk);
> + if (instance) {
> + if (!instance->dev)
> + instance->dev = dev;
> + queue_index =
> netpolicy_pick_queue(instance, false);
> + }
> + }
> + if (queue_index < 0)
> +#endif
I doubt this produces the intended effect. Several drivers use
ndo_select_queue (such as mlx4) where there might do something special
for a few packets but end up called the default handler which
__netdev_pick_tx for most packets. So in such cases the netpolicy path
would be routinely bypassed. Maybe this code should be in
__netdev_pick_tx.
Tom
> + queue_index = __netdev_pick_tx(dev, skb);
> + }
>
> if (!accel_priv)
> queue_index = netdev_cap_txqueue(dev, queue_index);
> --
> 2.5.5
>
