[PATCH net-next] [RFC] netns: enable cross-ve Unix sockets

[Cedric Le Goater]

Daniel Lezcano wrote:
> Cedric Le Goater wrote:
>> Pavel Emelyanov wrote:
>>> Daniel Lezcano wrote:
>>>> Pavel Emelyanov wrote:
>>>>>> So there are 2 cases:
>>>>>>   * full isolation : restriction on VPS
>>>>>>   * partial isolation : no restriction but *perhaps* problem when migrating
>>>>>>
>>>>>> Looks like we need an option per namespace to reduce the isolation for 
>>>>>> af_unix sockets :)
>>>>>>   - on (default): current behaviour => full isolation
>>>>>>   - off : partial isolation
>>>>> You mean some sysctl, that enables/disables this check in unix_find_socket_byinode?
>>>> Yes.
>>> OK. Den, please, do :)
>> hmm, would that allow sibling namespaces to connect to each other ? If so, 
>> I'm not in favor of such a solution. 
>>
>> I understand the need. we had a similar issue with the command line tool 
>> pgsl. Could we work something out with the capabilities ? or make an 
>> exception if your ->nsproxy->net_ns == init_net ? 
> 
> Why capabilities is better than a simple sysctl ?

because it depends on the current process privilege and not just some
random process.

> Making an exception for init_net will break the nested containers no ?

may be. I don't know how this is implemented. if we break isolation, my
feeling is that we should only do it for a parent namespace. It just feel 
wrong to allow sibling namespaces to connect to each other. 

C.