[RFC v4 00/11] snet: Security for NETwork syscalls

From: y
Date: Thu May 05 2011 - 10:11:09 EST

From: Samir Bellabes <sam@xxxxxxxxx>

Hello lsm and netdev people,
This set of patches is the version 4 of snet, which I would like to submit as a
RFC.

snet is a linux security module. It provides a mecanism defering syscall
security hooks and decision (verdict) to userspace.

snet has some subsystems :
- snet_core : init and exit the system
- snet_hooks : LSM hooks
- snet_netlink : kernel-user communication (genetlink)
- snet_event : manages the list of protected syscalls
- snet_verdict : provides a waitqueue for syscalls and manage verdicts
- snet_ticket : provides a granted-access ticket mecanism

I believe that snet will help to get over the classical configuration
complexity of others security modules, by providing interactivity to users.
I also think that monolithic strategy is broken with snet, as we can provide
security for others syscall's categories:
- sfs : security for filesystem,
- stask: security for task,
- smem : security for memory
..

In this way, and by putting abstraction on how this subsystems can talk to each
others, we may use the security combinaison we want: choose to run sfs,
stask, but not snet nor smem. Better, developpers may investigated how to build
another security subsystem for tasks, and use others existing (smem, snet..)
which they don't want to modify

I think that interactivity is very usefull for users, as they may be notify when
something is wrong and take decision, and from userspace, the decision may be
defered to another box. In this way, snet also have a advantage for mobile
devices as the policy decision will be push to a distant server, mobile device
will then wait for verdicts and as policy strategies are centralized.

Interactivity is *not* only clicking a Yes/No question, as said, we
can centralised previous locals LSM security subsytems, and make the
network aware of events occuring on it.

Finally, and a important point: snet integration respects the LSM framework idea
of using LSM hooks.

New feature from the previous version:
* Building a ticket mecanism for each task_struct using pointer void *security
Use the pointer (void*) security related to task_struct to provides
granted-acces tickets: if two identical requests are coming, ask the user
for the first one, store the result in a ticket and for the second request,
just look in the tickets owned by the task-struct
* send data buffer of sendmsg to userspace
this may provide a way to look inside the data (as a anti-virus do)

roadmap:
* find a way to send data buffer of sendmsg to userspace (using netfilter)
* adding other security systems
we can think about adding fork(), exec(), open(), close()..

I'm Ccing netfilter-devel, as snet may be seen as a way to do filtering.

v2..v3
* using kmem_cache instead of kmalloc
* remove attempt to send buffer socker to userspace

v3..v4
* add some statistics to count events in /proc/snet/snet_stats

Samir Bellabes (11):
lsm: add security_socket_closed()
lsm: reintroduce security_socket_post_accept()
snet: introduce snet_core
snet: introduce snet_event
snet: introduce snet_hooks
snet: introduce snet_netlink
snet: introduce snet_verdict
snet: introduce snet_ticket
snet: introduce snet_utils
snet: introduce snet_stats
snet: introduce security/snet, Makefile and Kconfig changes

include/linux/security.h | 23 +
include/linux/snet.h | 117 ++++++
net/socket.c | 3 +
security/Kconfig | 6 +
security/Makefile | 2 +
security/capability.c | 10 +
security/security.c | 10 +
security/snet/Kconfig | 11 +
security/snet/Makefile | 15 +
security/snet/snet_core.c | 84 ++++
security/snet/snet_event.c | 201 +++++++++
security/snet/snet_event.h | 21 +
security/snet/snet_hooks.c | 764 +++++++++++++++++++++++++++++++++++
security/snet/snet_hooks.h | 10 +
security/snet/snet_netlink.c | 442 ++++++++++++++++++++
security/snet/snet_netlink.h | 17 +
security/snet/snet_netlink_helper.c | 220 ++++++++++
security/snet/snet_netlink_helper.h | 7 +
security/snet/snet_stats.c | 65 +++
security/snet/snet_stats.h | 57 +++
security/snet/snet_ticket.c | 195 +++++++++
security/snet/snet_ticket.h | 37 ++
security/snet/snet_ticket_helper.c | 127 ++++++
security/snet/snet_ticket_helper.h | 8 +
security/snet/snet_utils.c | 39 ++
security/snet/snet_utils.h | 9 +
security/snet/snet_verdict.c | 203 ++++++++++
security/snet/snet_verdict.h | 23 +
28 files changed, 2726 insertions(+), 0 deletions(-)
create mode 100644 include/linux/snet.h
create mode 100644 security/snet/Kconfig
create mode 100644 security/snet/Makefile
create mode 100644 security/snet/snet_core.c
create mode 100644 security/snet/snet_event.c
create mode 100644 security/snet/snet_event.h
create mode 100644 security/snet/snet_hooks.c
create mode 100644 security/snet/snet_hooks.h
create mode 100644 security/snet/snet_netlink.c
create mode 100644 security/snet/snet_netlink.h
create mode 100644 security/snet/snet_netlink_helper.c
create mode 100644 security/snet/snet_netlink_helper.h
create mode 100644 security/snet/snet_stats.c
create mode 100644 security/snet/snet_stats.h
create mode 100644 security/snet/snet_ticket.c
create mode 100644 security/snet/snet_ticket.h
create mode 100644 security/snet/snet_ticket_helper.c
create mode 100644 security/snet/snet_ticket_helper.h
create mode 100644 security/snet/snet_utils.c
create mode 100644 security/snet/snet_utils.h
create mode 100644 security/snet/snet_verdict.c
create mode 100644 security/snet/snet_verdict.h

--
1.7.4.1

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