Restricting access by using custom buffer extension

Question

Hi,
I have a problem and a possible solution. Before I start implementing it, I would like to ask for your opinion about this.
The problem has to do with security. We have two kinds of services.
1) Primary services: The client accesses these services directly. Tuxedo does the authentication and the service performs a custom autorisation.
2) Secondary services: These services are accessed only by other services. Since other services are trusted, no autorisation is done. But one has to guarantee that no client accesses these services directly. This is where the problem is.
We currently have a solution. We do a call to the .TMIB to find out whether the acessor is a service or a client. But this solution doesn't scale because the .TMIB-service is implemented by the BBL, which is a single process.
Therefore I'm thinking about another solution. Clients use the WSL to access Tuxedo. Local clients can be regarded as trusted in our environment. We use only XOCTET-buffers as buffer-type. It is possible to implement custom-buffers and link the buffer-type-definitions to a custom WSH (see buildwsh).
I'm thinking on extending the definitions of the XOCTET buffer type and implement a custom routing-function. When the routing-type of a service is "secondary-service", then the routing fails. This extension will be linked only to the WSH, so the WSH denies routing to secondary-services but the rest of the system allows them.
Do you think this would work? Do you see problems? Is there a better/simpler solution?
Regards
Erhard

Answer 1

Hi Erhard,
I would suggest you another way. Ok, the question here is how to know the client is a local client or workstation client. You can take advantage of the data structure in tpsvcinfo.
The "cltid" structure of tpsvcinfo contains some client related information, though it is unofficial published. You can use clientdata[2] to get the client's slot number in Tuxedo bulletin board. Tuxedo has a logic to generate the slot number. For example, your MAXACCESSER is 200 and MAXWSCLTS is 10, the tuxedo will allocate workstation client from 190 (200 - 10). The local client and server will use from 0. So you can write your code like,
TOUPPER(TPSVCINFO *rqst)
     if ( rqst->cltid.clientdata[2] >= 190) {
userlog(" it is a workstation client");
tpreturn(TPFAIL);
The limitations are 1) if MAXACCESSERS and MAXWSCLTS changed, you have to tune the judge condition 2) it is un-offiicial interface, it is subject to Oracle to change. I think if your UBBCONFIG is stable you may take a try. The advantage is obvious, simple and no performance impact. You may try this first in a test environment.
Wayne