Re: [PATCH] net: ipv6: Truncate single route when it doesn't fit into dump buffer.

From: Jan Moskyto Matejka
Date: Fri May 12 2017 - 17:41:14 EST


On Fri, May 12, 2017 at 10:26:08AM -0700, David Ahern wrote:
> On 5/12/17 8:24 AM, David Miller wrote:
> > From: Jan Moskyto Matejka <mq@xxxxxx>
> > Date: Fri, 12 May 2017 13:15:10 +0200
> >
> >> -int rt6_dump_route(struct rt6_info *rt, void *p_arg);
> >> +int rt6_dump_route(struct rt6_info *rt, void *p_arg, int truncate);
> >
> > Please use "bool" and "true"/"false" for boolean values.
> >
> > What does ipv4 do in this situation?
> >
> > I'm hesitant to be OK with adding a new nlmsg flag just for this case
> > if we solve this problem differently and using existing mechanisms
> > elsewhere.
> >
>
> I'll take a look at this later today or this weekend; we can't just
> truncate the route returned to userspace.

Agreed. My favourite would be skb realloc somewhere inside the dump loop
... but I don't know whether it's feasible.

MQ