Re: Sockets from kernel space?

Re: Sockets from kernel space?

[Arnaldo Carvalho de Melo]

John Richard Moser wrote:
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> 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]

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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

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Re: Sockets from kernel space?

[Arnaldo Carvalho de Melo]

John Richard Moser wrote:
> -----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.

Look at the iproute2 code to know how to use netlink 8)

- Arnaldo