freebsd-src/tools/regression/security/proc_to_proc

$FreeBSD$

  Inter-Process Authorization Test Suite
  Robert Watson, TrustedBSD Project

This test suite attempts to determine the behavior of inter-process
authorization policy present in the kernel.  It analyzes a series of
important scenarios using specifically crafted process credentials
and a set of operations.  It then reports on any divergence from the
expected results.

Test operations:

ptrace		cred1 attempts ptrace attach to cred2
sighup		cred1 attempts SIGHUP of cred2
sigsegv		cred1 attempts SIGSEGV of cred2
see		cred1 attempts getpriority() on cred2
sched		cred1 attempts setpriority() on cred2

Test scenarioes:

priv on priv		root process on another root process
priv on unpriv1		root process on a non-root process
unpriv1 on priv		non-root process on a root process
unpriv1 on unpriv1	non-root process on a similar non-root process
unpriv1 on unpriv2	non-root process on a different non-root process
unpriv1 on daemon1	non-root process on a root daemon process acting with
			same non-root effective credentials
unpriv1 on daemon2	non-root process on a root daemon process acting with
			different non-root effective credentials
unpriv1 on setuid1	non-root process on a setuid-root process with same
			non-root real credentials
unpriv1 on setuid2	non-root process on a setuid-root process with
			different non-root real credentials

The credential elements supported by the test suite are:

	effective uid
	real uid
	saved uid
	P_SUGID flag

Other untested aspects of interest include groups, as well as session
relationship.  Other test operations that might be of interest are SIGCONT,
and SIGIO.

The current set of tests includes some tests where normally the P_SUGID
flag is set, but isn't in the test.  The result is that some tests fail
that may not reflect real-world software configurations.  However, they
do point to possible changes that could be made in the authorization system
to improve resilience to failure or violation of invariants.

These tests rely on __setugid(), a system call enabled using options
REGRESSION.