On 2/16/16 1:45 AM, YOSHIFUJI Hideaki wrote:
>> diff --git a/Documentation/networking/ip-sysctl.txt
>> b/Documentation/networking/ip-sysctl.txt
>> index 24ce97f42d35..7ddbbb67f0db 100644
>> --- a/Documentation/networking/ip-sysctl.txt
>> +++ b/Documentation/networking/ip-sysctl.txt
>> @@ -1563,6 +1563,12 @@ temp_prefered_lft - INTEGER
>> Preferred lifetime (in seconds) for temporary addresses.
>> Default: 86400 (1 day)
>>
>> +keep_addr_on_down - BOOLEAN
>> + Keep all IPv6 addresses on an interface down event. If set static
>> + global addresses with no expiration time are not flushed.
>> +
>> + Default: disabled
>> +
>
> How about this:
> 1: enabled
> 0: system default
> -1: disabled
> so that an iterface can override system-wide config?
It is my understanding that the 'all' settings override the individual
interface settings. From Documentation/networking/ip-sysctl.txt +1346:
conf/all/*:
Change all the interface-specific settings.
-----8<-----
>> diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
>> index 1c8b6820b694..01ba6a286a4b 100644
>> --- a/include/net/if_inet6.h
>> +++ b/include/net/if_inet6.h
>> @@ -72,6 +72,7 @@ struct inet6_ifaddr {
>> int regen_count;
>>
>> bool tokenized;
>> + bool user_managed;
>
> Can't we use IFA_F_PERMANENT?
I think so. Will fix.
-----8<-----
>> @@ -3356,7 +3413,9 @@ static int addrconf_ifdown(struct net_device *dev, int
>> how)
>> {
>> struct net *net = dev_net(dev);
>> struct inet6_dev *idev;
>> - struct inet6_ifaddr *ifa;
>> + struct inet6_ifaddr *ifa, *tmp;
>> + struct list_head del_list;
>> + int keep_addr;
>> int state, i;
>>
>> ASSERT_RTNL();
>> @@ -3383,6 +3442,10 @@ static int addrconf_ifdown(struct net_device *dev,
>> int how)
>>
>> }
>>
>> + keep_addr = net->ipv6.devconf_all->keep_addr_on_down;
>> + if (!keep_addr)
>> + keep_addr = idev->cnf.keep_addr_on_down;
>> +
>> /* Step 2: clear hash table */
>> for (i = 0; i < IN6_ADDR_HSIZE; i++) {
>> struct hlist_head *h = &inet6_addr_lst[i];
So what I have here is if the system-wide setting says keep the address
it is kept. Else if the individual interface setting is enabled the
address is kept.
