Re: [PATCH v3] af_netlink: ensure that NLMSG_DONE never fails in dumps

[Jason A. Donenfeld]

On Thu, Nov 9, 2017 at 11:02 AM, Johannes Berg
<johannes@xxxxxxxxxxxxxxxx> wrote:
> nit: I think your line got a little long here :)

Ack. For v4.

> and here

Ack. For v4.

>
>> +     nlk->dump_done_errno = INT_MAX;
>
> I guess positive values aren't really returned from dump?

When a positive value is returned, the API uses this to signify that
the dump is not done, and it should be called again. When 0 or
negative is returned, it means the dump is complete and the return
value should be returned in DONE. We therefore initialize
dump_done_errno to some positive value, so that we can make calling
->dump() conditional on it being positive. When it becomes zero or
negative, it's time to return. This mirrors the semantics of the
actual ->dump() function precisely.