blob: f1b0ebb99a82711edb607e938e9359eb376a967e [file] [log] [blame]
/*
* Author: Mary Garvin <mgarvin@tresys.com>
*
* Copyright (C) 2007-2008 Tresys Technology, LLC
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "test-downgrade.h"
#include "parse_util.h"
#include "helpers.h"
#include <sepol/debug.h>
#include <sepol/handle.h>
#include <sepol/policydb/policydb.h>
#include <sepol/policydb/link.h>
#include <sepol/policydb/expand.h>
#include <sepol/policydb/conditional.h>
#include <limits.h>
#include <CUnit/Basic.h>
#define POLICY_BIN_HI "policies/test-downgrade/policy.hi"
#define POLICY_BIN_LO "policies/test-downgrade/policy.lo"
static policydb_t policydb;
/*
* Function Name: downgrade_test_init
*
* Input: None
*
* Output: None
*
* Description: Initialize the policydb (policy data base structure)
*/
int downgrade_test_init(void)
{
/* Initialize the policydb_t structure */
if (policydb_init(&policydb)) {
fprintf(stderr, "%s: Out of memory!\n", __FUNCTION__);
return -1;
}
return 0;
}
/*
* Function Name: downgrade_test_cleanup
*
* Input: None
*
* Output: None
*
* Description: Destroys policydb structure
*/
int downgrade_test_cleanup(void)
{
policydb_destroy(&policydb);
return 0;
}
/*
* Function Name: downgrade_add_tests
*
* Input: CU_pSuite
*
* Output: Returns 0 upon success. Returns a CUnit error value on failure.
*
* Description: Add the given downgrade tests to the downgrade suite.
*/
int downgrade_add_tests(CU_pSuite suite)
{
if (CU_add_test(suite, "downgrade", test_downgrade) == NULL)
return CU_get_error();
return 0;
}
/*
* Function Name: test_downgrade_possible
*
* Input: None
*
* Output: None
*
* Description:
* Tests the backward compatibility of MLS and Non-MLS binary policy versions.
*/
void test_downgrade(void)
{
if (do_downgrade_test(0) < 0)
fprintf(stderr,
"\nError during downgrade testing of Non-MLS policy\n");
if (do_downgrade_test(1) < 0)
fprintf(stderr,
"\nError during downgrade testing of MLS policy\n");
}
/*
* Function Name: do_downgrade_test
*
* Input: 0 for Non-MLS policy and 1 for MLS policy downgrade testing
*
* Output: 0 on success, negative number upon failure
*
* Description: This function handles the downgrade testing.
* A binary policy is read into the policydb structure, the
* policy version is decreased by a specific amount, written
* back out and then read back in again. The process is
* repeated until the minimum policy version is reached.
*/
int do_downgrade_test(int mls)
{
policydb_t policydb_tmp;
int hi, lo, version;
/* Reset policydb for re-use */
policydb_destroy(&policydb);
downgrade_test_init();
/* Read in the hi policy from file */
if (read_binary_policy(POLICY_BIN_HI, &policydb) != 0) {
fprintf(stderr, "error reading %spolicy binary\n", mls ? "mls " : "");
CU_FAIL("Unable to read the binary policy");
return -1;
}
/* Change MLS value based on parameter */
policydb.mls = mls ? 1 : 0;
for (hi = policydb.policyvers; hi >= POLICYDB_VERSION_MIN; hi--) {
/* Stash old version number */
version = policydb.policyvers;
/* Try downgrading to each possible version. */
for (lo = hi - 1; lo >= POLICYDB_VERSION_MIN; lo--) {
/* Reduce policy version */
policydb.policyvers = lo;
/* Write out modified binary policy */
if (write_binary_policy(POLICY_BIN_LO, &policydb) != 0) {
/*
* Error from MLS to pre-MLS is expected due
* to MLS re-implementation in version 19.
*/
if (mls && lo < POLICYDB_VERSION_MLS)
continue;
fprintf(stderr, "error writing %spolicy binary, version %d (downgraded from %d)\n", mls ? "mls " : "", lo, hi);
CU_FAIL("Failed to write downgraded binary policy");
return -1;
}
/* Make sure we can read back what we wrote. */
if (policydb_init(&policydb_tmp)) {
fprintf(stderr, "%s: Out of memory!\n",
__FUNCTION__);
return -1;
}
if (read_binary_policy(POLICY_BIN_LO, &policydb_tmp) != 0) {
fprintf(stderr, "error reading %spolicy binary, version %d (downgraded from %d)\n", mls ? "mls " : "", lo, hi);
CU_FAIL("Unable to read downgraded binary policy");
return -1;
}
policydb_destroy(&policydb_tmp);
}
/* Restore version number */
policydb.policyvers = version;
}
return 0;
}
/*
* Function Name: read_binary_policy
*
* Input: char * which is the path to the file containing the binary policy
*
* Output: Returns 0 upon success. Upon failure, -1 is returned.
* Possible failures are, filename with given path does not exist,
* a failure to open the file, or a failure from prolicydb_read
* function call.
*
* Description: Get a filename, open file and read binary policy into policydb
* structure.
*/
int read_binary_policy(const char *path, policydb_t *p)
{
FILE *in_fp = NULL;
struct policy_file f;
int rc;
/* Open the binary policy file */
if ((in_fp = fopen(path, "rb")) == NULL) {
fprintf(stderr, "Unable to open %s: %s\n", path,
strerror(errno));
return -1;
}
/* Read in the binary policy. */
memset(&f, 0, sizeof(struct policy_file));
f.type = PF_USE_STDIO;
f.fp = in_fp;
rc = policydb_read(p, &f, 0);
fclose(in_fp);
return rc;
}
/*
* Function Name: write_binary_policy
*
* Input: char * which is the path to the file containing the binary policy
*
* Output: Returns 0 upon success. Upon failure, -1 is returned.
* Possible failures are, filename with given path does not exist,
* a failure to open the file, or a failure from prolicydb_read
* function call.
*
* Description: open file and write the binary policy from policydb structure.
*/
int write_binary_policy(const char *path, policydb_t *p)
{
FILE *out_fp = NULL;
struct policy_file f;
sepol_handle_t *handle;
int rc;
/* We don't want libsepol to print warnings to stderr */
handle = sepol_handle_create();
if (handle == NULL) {
fprintf(stderr, "Out of memory!\n");
return -1;
}
sepol_msg_set_callback(handle, NULL, NULL);
/* Open the binary policy file for writing */
if ((out_fp = fopen(path, "w" )) == NULL) {
fprintf(stderr, "Unable to open %s: %s\n", path,
strerror(errno));
sepol_handle_destroy(handle);
return -1;
}
/* Write the binary policy */
memset(&f, 0, sizeof(struct policy_file));
f.type = PF_USE_STDIO;
f.fp = out_fp;
f.handle = handle;
rc = policydb_write(p, &f);
sepol_handle_destroy(f.handle);
fclose(out_fp);
return rc;
}