[redhat-lspp] Re: [RFC] [MLSXFRM 02/04] Add enforcement to SE Linux LSM

[Venkat Yekkirala]

> We have flows, sa's, and in some cases, senders and receivers.  On  
> input, we check the socket's access to receive the sa's type in  
> rcv_skb, and on output we check the flow's (indirectly socket's, if  
> present) access to send to the sa's type in flow_state_match.
> 
> The problem is that the types of the flow and policy are required to  
> match in lookup, but that is not a requirement for
> types.

Did you mean to say sockets (instead of types) at the end above or did I
miss something?

>   A socket  
> of type x can use a policy of type y which can be captured on

> input,  

Actually this would be output (albeit indirectly via the flow).

> but not on 

> output in this patch.

You probably meant "input" here?

> 
> I'll think about possible resolutions, but here are some further  
> questions.
> 
> (1) must a flow type match that of the sa it uses (seems so)?

Yes. The flow type must have sendto access to the SA.

> (2) can we do lookup differently for input (where we are told 
> what it  
> should be) versus output (where it is based on what could be  
> authorized)?

I am not getting this question. Please let me know on the side
when would be a good time to call you. Thanks.