From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kurt Van Dijck Subject: Re: [PATCH] can: test size of struct sockaddr Date: Sat, 15 Jan 2011 20:35:27 +0100 Message-ID: <20110115193526.GB463@e-circ.dyndns.org> References: <20110114172321.GB331@e-circ.dyndns.org> <4D31D4A6.4040701@hartkopp.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Oliver Hartkopp Return-path: Content-Disposition: inline In-Reply-To: <4D31D4A6.4040701-fJ+pQTUTwRTk1uMJSBkQmQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.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