Re: [Qemu-devel] [PULL 1/9] qapi: Add InetSocketAddress member keep-alive

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

09.09.2019 20:32, Peter Maydell wrote:
> On Thu, 15 Aug 2019 at 19:34, Eric Blake <eblake@redhat.com> wrote:
>>
>> From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>
>> It's needed to provide keepalive for nbd client to track server
>> availability.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> Message-Id: <20190725094937.32454-1-vsementsov@virtuozzo.com>
>> Reviewed-by: Markus Armbruster <armbru@redhat.com>
>> Acked-by: Daniel P. Berrangé <berrange@redhat.com>
>> [eblake: Fix error message typo]
>> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> Hi; Coverity spots a bug in this change (CID 1405300):

Two coverity bugs on my patches, I'm sorry :(

How can I run this coverity locally?

> 
>> @@ -458,6 +464,19 @@ int inet_connect_saddr(InetSocketAddress *saddr, Error **errp)
>>       }
> 
> At this point in the function, we might be in one of
> two cases:
>   (1) sock >= 0 : the connect succeeded
>   (2) sock < 0 : connect failed, we have just called
>       error_propagate() and are using the same end-of-function
>       codepath to free 'res' before returning the error code.
> 
>>
>>       freeaddrinfo(res);
>> +
>> +    if (saddr->keep_alive) {
>> +        int val = 1;
>> +        int ret = qemu_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
>> +                                  &val, sizeof(val));
> 
> ...but here we use 'sock' assuming it is valid.
> 
>> +
>> +        if (ret < 0) {
>> +            error_setg_errno(errp, errno, "Unable to set KEEPALIVE");
>> +            close(sock);
>> +            return -1;
>> +        }
>> +    }
>> +
>>       return sock;
>>   }
> 
> If we want to add more "actual work" at this point in
> the function we should probably separate out the failed-case
> codepath, eg by changing
> 
> 
>      if (sock < 0) {
>          error_propagate(errp, local_err);
>      }
> 
>      freeaddrinfo(res);
> 
> into
> 
>      freeaddrinfo(res);
> 
>      if (sock < 0) {
>          error_propagate(errp, local_err);
>          return sock;
>      }
> 
> 
> 
> thanks
> -- PMM
> 

Thanks, this should work, I'll send a patch soon.

-- 
Best regards,
Vladimir