Re: [patch net-next 0/2] Fixes for raw diag sockets handling

On 11/2/16 6:36 AM, Cyrill Gorcunov wrote:

Also I have a question about sockets lookup not for raw diag only
(though I didn't modify lookup procedure) but in general: the structure
inet_diag_req_v2 has inet_diag_sockid::idiag_if member which supposed to
carry interface index from userspace request.

Then for example in INET_MATCH (include/net/inet_hashtables.h),
the __dif parameter (which is @idiag_if) compared with @sk_bound_dev_if
*iif* the sk_bound_dev_if has been ever set. Thus if say someone
looks up for paticular device with specified index if the
rest of parameters match and SO_BINDTODEVICE never been called
for this device we return the socket even if idiag_if is not zero.
Is it supposed to be so? Or I miss something obvious?

I mean this snippet


	 (!(__sk)->sk_bound_dev_if	||				\
	   ((__sk)->sk_bound_dev_if == (__dif))) 	&&		\

when someone calls for destory sockets on particular interface and
@__dif != 0 the match may return socket where sk_bound_dev_if = 0
instead of completely matching one. Isn't it?

yes. I recently added an exact_dif to the lookup for listener sockets (see compute_score). Something like that could be added to INET_MATCH.