[CRIU] [PATCH 1/3]v3 libcriu: criu_dump_me() and library header

[Ruslan Kuprieiev]

On 08/30/2013 12:04 AM, Pavel Emelyanov wrote:
> On 08/29/2013 11:44 PM, Ruslan Kuprieiev wrote:
>> On 08/29/2013 11:21 PM, Pavel Emelyanov wrote:
>>> On 08/29/2013 11:08 PM, Ruslan Kuprieiev wrote:
>>>> Hi!
>>>>
>>>> Patch 1\3 contains criu_dump_me() for library and library header.
>>>>           -- criu_dump_me() gets an argument of  type struct criu_dump_args
>>>> from user program,
>>>>             processes it and sends request to criu through unix domain
>>>> socket.
>>>>             Then, it gets flag from criu and returns it back to program.
>>>>           -- libcriu.h contains definitions of flags, struct
>>>> criu_dump_args etc.
>>>>              So, it is to be used in user program.
>>>>
>>>> Signed-off-by: Ruslan Kuprieiev <kupruser at gmail.com>
>>>>
>>>> +int criu_dump_me(struct criu_dump_args *arg)
>>>> +{
>>>> +	int socket_fd;
>>>> +	int ret, c;
>>>> +	struct sockaddr_un server_addr;
>>>> +	socklen_t server_addr_len;
>>> I'm trying to imagine how this all should work when a user that has some
>>> 3rd party app linked with v0.7's libcriu.so upgrades criu and has v0.8's
>>> one with criu_dump_args extended.
>>>
>>> In his software the new "tail" of this structure is not seen (as hi had it
>>> compiled against old headers with shorted struct). Thus we'd see uninitialized
>>> data here in the library and have no idea how to check this.
>>>
>>> I think we need the criu_alloc_args() call that will call malloc() with
>>> proper size and zeroify the whole structure.
Maybe, criu_alloc_args() should malloc "struct criu_dump_args *args" and 
return "args" , witch will be like "opts" in crtools?

>> Ok, i will fix it.
>> By the way, maybe i should add version check? (maybe, after i fix what i
>> should fix, and first patch will be applied)
>> Correct me, if i'm mistaken.
>> I should add criu_check_version(), that must be called right after
>> connect to socket.
>> It should send version of library and recv "true" if
>> libversion<=criuversion or "false" if libversion>criuversion.
>> Also add some CRIU_OLD_VERSION macro to return for "false" case.
>>
>> .
>>
>
> yup