On Wed, Sep 21, 2016 at 12:13:43AM +0300, Cyrill Gorcunov wrote:
> On Fri, Sep 16, 2016 at 11:07:22PM +0300, Cyrill Gorcunov wrote:
> > > It may well be a ss bug / problem. As I mentioned I am always seeing 255
> > > for the protocol which
> >
> > It is rather not addressed in ss. I mean, look, when we send out a diag
> > packet
> > the kernel look ups for a handler, which for raw protocol we register as
> >
> > static const struct inet_diag_handler raw_diag_handler = {
> > .dump= raw_diag_dump,
> > .dump_one= raw_diag_dump_one,
> > .idiag_get_info= raw_diag_get_info,
> > .idiag_type= IPPROTO_RAW,
> > .idiag_info_size= 0,
> > #ifdef CONFIG_INET_DIAG_DESTROY
> > .destroy= raw_diag_destroy,
> > #endif
> > };
> >
> > so if we patch ss and ask for IPPROTO_ICMP in netlink packet the
> > kernel simply won't find anything. Thus I think we need (well, I need)
> > to extend the patch and register IPPROTO_ICMP diag type, then
> > extend ss as well. (If only I didn't miss somethin obvious).
> >
> > > is odd since ss does a dump and takes the matches and invokes the kill.
> > > Thanks for taking the time to do the kill piece.
>
> Sorry for delay in reply (I got flu unexpectedly). You know, it eventually
> become uneasy to implement handling for sock-raw because they are special.
> They described as ipproto-ip in net/ipv4/af_inet.c, so it matches any
> protocol specified with the socket call. In turn inet-diag module handled
> predefined protocols only, in particular IPPROTO_RAW in our case. Thus
> to fecth some real protocol sitting in raw sockets hashes we need some
> kind of additional argument passed in the request. I guess we may
> use @idiag_ext field for this sake? Or require @idiag_ext to have
> INET_DIAG_PROTOCOL bit set and then fetch real protocol from
> additional attribute? Sounds ok?
Something like
Index: linux-ml.git/include/uapi/linux/inet_diag.h
===================================================================
--- linux-ml.git.orig/include/uapi/linux/inet_diag.h 2016-09-11
20:56:18.191584145 +0300
+++ linux-ml.git/include/uapi/linux/inet_diag.h 2016-09-27 01:34:08.413172394
+0300
@@ -38,7 +38,7 @@ struct inet_diag_req_v2 {
__u8 sdiag_family;
__u8 sdiag_protocol;
__u8 idiag_ext;
- __u8 pad;
+ __u8 sdiag_raw_protocol; /* SOCK_RAW only, @pad for others */
__u32 idiag_states;
struct inet_diag_sockid id;
};
and in raw-diag module we will use @sdiag_raw_protocol instead of
@sdiag_protocol field. Didn't cover ss tool source code yet but
I think the idea is seen. Still not sure if start using @pad here
is a good idea (it's uapi), maybe beter to ask nla attribute which would
come right afterh the inet_diag_req_v2 message?
Cyrill
