Re: [PATCH 1/4] net: if_arp: add ARPHRD_PUREIP type

[David Ahern]

On 6/23/21 9:33 PM, Rocco Yue wrote:
> 
> The difference between RAWIP and PUREIP is that they generate IPv6
> link-local address and IPv6 global address in different ways.
> 
> RAWIP:
> ~~~~~~
> In the ipv6_generate_eui64() function, using RAWIP will always return 0,
> which will cause the kernel to automatically generate an IPv6 link-local
> address in EUI64 format and an IPv6 global address in EUI64 format.
> 
> PUREIP:
> ~~~~~~~
> After this patch set, when using PUREIP, kernel doesn't generate IPv6
> link-local address regardless of which IN6_ADDR_GEN_MODE is used.
> 
> @@  static void addrconf_dev_config(struct net_device *dev)
> +       if (dev->type == ARPHRD_PUREIP)
> +               return;
> 
> And after recving RA message, kernel iterates over the link-local address
> that exists for the interface and uses the low 64bits of the link-local
> address to generate the IPv6 global address.
> The general process is as follows:
> ndisc_router_discovery() -> addrconf_prefix_rcv() -> ipv6_generate_eui64() -> ipv6_inherit_eui64()
> 

please add that to the commit message.