FastRPC

FastRPC is a small, prototype piece of code that implements a local-only RPC transport. Compared to systems like CORBA or DCOM it sacrifices network transparency, language neutrality and portability to implement a small, fast and easy to use RPC framework for C/C++ programs.

An example of how to use it:

 
static int foo(int a, char **b) { ... }   /* implementation of a function in one C file */
static rpc_call dispatch_table[] = { (rpc_call) &foo, NULL };


RPC_PROXY("foo", 1);  /* define the proxy in another C file (where it's used) */
.....

char *str = NULL;
int result = foo(42, &str);   /* stack access is allowed, and a shared heap is provided */
That's it. There are no IDL compilers and extraneous typing is kept to a minimum. The code, once using RPC, looks much like it did originally. To pull this off various low level tricks are used - this is the reason FastRPC optimises for low code impact over portability.

FastRPC is designed for only one use case - splitting monolithic programs into multiple co-operating processes that can be confined by a kernel security framework like SELinux or AppArmor. For instance, it could be used to separate an image decoder out of an instant messenger so that an attack using corrupted image files would not grant the attacker all the privileges the chat program posesses. A sample showing a simple image viewer program that does this is included. This work was directly inspired by Colin Walters and his IMsep project.

This code suffers many limitations - it was written for a university dissertation and was therefore implemented only as far as necessary to get a good mark. It is not portable at all, not thread safe, not 64 bit safe, and documented only in the example program, header file and accompanying report. It is not "library-ized" in the standard GNU fashion. It has only been tested on Linux with gcc.

The rationale and design of FastRPC is discussed more in the report, "Security oriented fast RPC".

Get the code.

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I don't intend to work on this again. If you find it useful please let me know. This code is GPL licensed.