Re: [PATCH v3 net-next 4/4] net/sched: act_mirred: Implement ingress actions

On Thu, Oct 6, 2016 at 6:30 AM, Shmulik Ladkani
[off-list ref] wrote:

Hi,

On Mon, Oct 3, 2016 at 12:45 PM, Cong Wang [off-list ref] wrote:

quoted

On Thu, Sep 29, 2016 at 4:03 AM, Shmulik Ladkani
[off-list ref] wrote:

quoted

        skb2->skb_iif = skb->dev->ifindex;
        skb2->dev = dev;
-       err = dev_queue_xmit(skb2);
+       if (tcf_mirred_act_direction(m_eaction) & AT_EGRESS)
+               err = dev_queue_xmit(skb2);
+       else
+               netif_receive_skb(skb2);

Any reason why not check the return value here?

Rationale: netif_receive_skb returns err if there was no protocol
handler to deliver the skb to.
If skb is not caught by any protocol handler, this should not be
considered an "ingress redirect" error. The redirect action should be
considered successful.

A quick grep shows there are many places returning NET_RX_DROP:
E.g.

net/ipv4/arp.c: return NET_RX_DROP;
net/ipv4/arp.c: return NET_RX_DROP;
net/ipv4/gre_demux.c:   return NET_RX_DROP;
net/ipv4/ip_forward.c:  return NET_RX_DROP;
net/ipv4/ip_input.c:    return NET_RX_DROP;
net/ipv4/ip_input.c:    return NET_RX_DROP;
net/ipv4/ipconfig.c:            return NET_RX_DROP;
net/ipv4/ipconfig.c:            return NET_RX_DROP;
net/ipv4/raw.c:         return NET_RX_DROP;
net/ipv4/raw.c:         return NET_RX_DROP;
net/ipv4/xfrm4_input.c: return NET_RX_DROP;
net/ipv6/ip6_input.c:           return NET_RX_DROP;
net/ipv6/ip6_input.c:                   return NET_RX_DROP;
net/ipv6/ip6_input.c:   return NET_RX_DROP;
net/ipv6/raw.c:         return NET_RX_DROP;
net/ipv6/raw.c:         return NET_RX_DROP;
net/ipv6/raw.c:         return NET_RX_DROP;
net/ipv6/raw.c:                 return NET_RX_DROP;