Sockets from kernel space?

Sockets from kernel space?

[John Richard Moser]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Is it possible to create socket connections (AF_UNIX for example) from
the kernel to local user processes that are listen()ing?

A good link to somewhere to help with this would be nice.

- --
All content of all messages exchanged herein are left in the
Public Domain, unless otherwise explicitly stated.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.6 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFBwOcfhDd4aOud5P8RAkuYAJ0fvVUPHI5Wg3jn2ZNp0Y/2wSIRMgCfZDDb
jJ+HOC9hbvTj8a/niubR2Dc=
=ONFE
-----END PGP SIGNATURE-----

Re: Sockets from kernel space?

[Arnaldo Carvalho de Melo]

John Richard Moser wrote:
> -----BEGIN PGP SIGNED MESSAGE----- 
> Is it possible to create socket connections (AF_UNIX for example) from
> the kernel to local user processes that are listen()ing?
> 
> A good link to somewhere to help with this would be nice.

Please send networking development related messages to netdev@oss.sgi.com,
there are several networking hackers that don't even subscribe lkml.

Having said that, look at the svc_makesock and svc_create_socket functions
in net/sunrpc/svcsock.c as a starting point.

- Arnaldo

Re: Sockets from kernel space?

[John Richard Moser]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Thanks.  I'll look at those.

I'm aiming at potentially writing an LSM that allows a process to attach
to the kernel, which will then be sent messages through an AF_UNIX
(these are the app<->app sockets right?) socket with the details of any
listen(2) or connect(2) calls made.  I was going to do it in userspace,
but realized it was easily avoidable that way.

If this works, I can pretty much securely create a host firewall that
regulates based on network operations, user, and program.  This would
allow the creation of discressionary firewalls, like Zone Alarm, Norton
PF, McAffee PF, etc.  The daemon sits in userspace, the kernel asks it
for policy decisions, it asks connected/authenticated clients about
unknown policy, and makes them re-authenticate to get an answer.  The
authentication is in userspace (PAM), hence the daemon.

Arnaldo Carvalho de Melo wrote:
[...]
|
| Please send networking development related messages to netdev@oss.sgi.com,
| there are several networking hackers that don't even subscribe lkml.
|
| Having said that, look at the svc_makesock and svc_create_socket functions
| in net/sunrpc/svcsock.c as a starting point.
|
| - Arnaldo

- --
All content of all messages exchanged herein are left in the
Public Domain, unless otherwise explicitly stated.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.6 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFBwP26hDd4aOud5P8RAhSjAJ956RdBt9deoh3RgW7UKWdEgNeLMACeOR+b
nVFR/uA/ZNXkv2b6HYcRczw=
=VUfC
-----END PGP SIGNATURE-----

Re: Sockets from kernel space?

[Martin Waitz]

[-- Attachment #1: Type: text/plain, Size: 361 bytes --]

hoi :)

On Wed, Dec 15, 2004 at 08:38:40PM -0500, John Richard Moser wrote:
> Is it possible to create socket connections (AF_UNIX for example) from
> the kernel to local user processes that are listen()ing?

AF_NETLINK is made for exactly that purpose.

look at linux/netlink.h and net/ipv4/netfilter/ipt_ULOG.c for example code.

-- 
Martin Waitz

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 189 bytes --]