To restrict IPMI commands

[P. K. Lee (李柏寬)]

> On Mar 27, 2019, at 22:39, Brad Bishop <bradleyb at fuzziesquirrel.com> wrote:
> 
> On Sat, Mar 16, 2019 at 01:04:53PM +0000, P. K. Lee (李柏寬) wrote:
>> Hi Vernon,
>> 
>> Thank you for providing a new filtering mechanism that looks very
>> flexible, but I have a question.  I have tried the filter that allows
>> filtering of commands by whitelistFilter, but the channel of request
>> must be channelSystemIfac to check the contents of the whitelist.  What
>> puzzles me is why channelSystemIfac is in the constraint? This
>> constraint will cause the whitelist to fail when the user calls the
>> IPMI command via the LAN.  If the user wants to use the whitelist vis
>> the LAN, 
> 
> Hi P.K.
> 
> If I understand correctly, you want to have a system that operates in
> one of two modes - restricted or un-restricted.  When the system is in
> restricted mode, only whitelisted commands will be processed from _any_
> channel.  Do I understand correctly?

Yes, we need to use the whitelist mechanism to restrict IPMI commands 
from any channel.

> How do you restore the system to unrestricted mode?  Some side-band (non
> IPMI) mechanism?

For us, it can use the REST to change the restriction mode as well.

> If you are able to share, I'm curious to know more about the usage
> pattern driving the need for this.

I thought that the configuration can be modified the format of 
<NetFn>:<Command>:<Channel> to apply the whitelist with multiple channels, 
where <Channel> uses 2 bytes to map the channel using a bit array.

For example:
0x06:0x01:0xFFFE  // The 0xFFFE is used 2 bytes to represent the channel 1~15

However, in order to be compatible with the current design, the <NetFn>:<Command> still only uses the system interface.

Best,
P.K.