Re: [PATCH v3] net: Require exact match for TCP socket lookups if dif is l3mdev

On 10/15/16 3:46 PM, David Miller wrote:

From: David Ahern <redacted>
Date: Fri, 14 Oct 2016 12:29:19 -0700

quoted

+/* can not be used in TCP layer after tcp_v6_fill_cb */
+static inline bool inet6_exact_dif_match(struct net *net, struct sk_buff *skb)
+{
+#if defined(CONFIG_NET_L3_MASTER_DEV)
+	if (!net->ipv4.sysctl_tcp_l3mdev_accept &&
+	    skb_l3mdev_slave(IP6CB(skb)->flags))
+		return true;
+#endif
+	return false;
+}

 ...

quoted

+static inline bool skb_l3mdev_slave4(u16 flags)
+{
+	return !!(flags & IPSKB_L3SLAVE);
+}

I think this makes the code confusing.

Actually it has been from the beginning, because we have a generically
named "skb_l3mdev_slave()" helper which strictly operates on ipv6
state.

Please do something with the naming of these two helpers,
skb_l3mdev_slave() and skb_l3mdev_slave4(), so that it is clear that
they are ipv6 and ipv4 specific helpers, respectively.

I believe at netconf someone mentioned it would be a great day when something is done for IPv6 first and IPv4 was a follow on. Here you go. :-)

I can rename the existing one to skb_l3mdev_slave_6 and make the new one skb_l3mdev_slave_4.