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

[Pavel Emelyanov]

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.
>>
> 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