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

[Rocco Yue <rocco.yue@mediatek.com>]

On Wed, 2021-06-23 at 23:15 -0600, David Ahern wrote:
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.

Thanks for your reminding, will do.

Thanks,
Rocco