Re: [PATCH] can: test size of struct sockaddr

[Kurt Van Dijck <kurt.van.dijck-/BeEPy95v10@public.gmane.org>]

On Sat, Jan 15, 2011 at 06:08:54PM +0100, Oliver Hartkopp wrote:
> On 14.01.2011 18:23, Kurt Van Dijck wrote:
> > I think this patch makes the CAN socket code comform to the
> > manpages of sendmsg & recvmsg.
> 
> Hello Kurt,
> 
> if you check similar code sniplets in the kernel you would see, that in
> recvmsg()-cases the given namelen is not used from userspace.
I went into udp code, but my mind got troubled there.
> 
> If msg->msg_name is not NULL the msg_namelen is just set by the kernel. E.g.
> see af_packet.c, af_econet.c, etc.
I should have looked further ...
Given this, I went up to net/socket.c:__sys_recvmsg.
Within kernel space, a struct sockaddr_storage is used in fact ....
This solves indeed the problem I was trying to address.
> 
> So the code in candump.c setting the msg_namelen before recvmsg() is obviously
> obsolete ...
I think no, since after the socket's recvmsg() has been called, 
since move_addr_to_user() will do checks similar as I tried to reimplement.
> 
> Btw. your two patches below for bcm_sendmsg() and raw_sendmesg() look good.
> 
> If you would like to resubmit these two patches, you may add my Acked-by
Thanks, I will do so.

Kurt