On a SELinux disabled system the python call
`selinux.security_policyvers()` will fail.
Move the logic to find a binary policy from the python script
`sepolgen-ifgen` to the C-helper `sepolgen-ifgen-attr-helper`.
Change the helper command line interface to accept an optional policy
path as second argument. If not given try the current loaded policy
(`selinux_current_policy_path`) and if running on a SELinux disabled
system iterate over the default store path appending policy versions
starting at the maximum supported policy version
(`sepol_policy_kern_vers_max`).
This changes the helper command line interface from:
sepolgen-ifgen-attr-helper policy_file out_file
to
sepolgen-ifgen-attr-helper out_file [policy_file]
and adds a linkage to libselinux.
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
v5: - Do not check bare selinux_binary_policy_path()
- Link helper dynamically with libselinux
v4: Improve the behavior on no explicit policy path given:
- Reorder helper's command line interface
- Use loaded policy on SELinux enabled systems
v3: Move the iteration logic from sepolgen-ifgen to
sepolgen-ifgen-attr-helper and use sepol_policy_kern_vers_max()
instead of selinux.security_policyvers(), to work on SELinux
disabled systems
python/audit2allow/Makefile | 2 +-
python/audit2allow/sepolgen-ifgen | 28 ++------------
.../audit2allow/sepolgen-ifgen-attr-helper.c | 38 +++++++++++++++++--
3 files changed, 39 insertions(+), 29 deletions(-)
diff --git a/python/audit2allow/Makefile b/python/audit2allow/Makefile
index 15db5490..025c282a 100644
--- a/python/audit2allow/Makefile
+++ b/python/audit2allow/Makefile
@@ -18,7 +18,7 @@ endif
all: audit2why sepolgen-ifgen-attr-helper
-sepolgen-ifgen-attr-helper: sepolgen-ifgen-attr-helper.o $(LIBSEPOLA)
+sepolgen-ifgen-attr-helper: sepolgen-ifgen-attr-helper.o $(LIBSEPOLA) -lselinux
$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS_LIBSEPOLA)
audit2why:
diff --git a/python/audit2allow/sepolgen-ifgen b/python/audit2allow/sepolgen-ifgen
index 4a71cda4..b7a04c71 100644
--- a/python/audit2allow/sepolgen-ifgen
+++ b/python/audit2allow/sepolgen-ifgen
@@ -27,7 +27,6 @@
import sys
-import os
import tempfile
import subprocess
@@ -65,37 +64,18 @@ def parse_options():
return options
-def get_policy():
- p = selinux.selinux_current_policy_path()
- if p and os.path.exists(p):
- return p
- i = selinux.security_policyvers()
- p = selinux.selinux_binary_policy_path() + "." + str(i)
- while i > 0 and not os.path.exists(p):
- i = i - 1
- p = selinux.selinux_binary_policy_path() + "." + str(i)
- if i > 0:
- return p
- return None
-
-
def get_attrs(policy_path, attr_helper):
try:
- if not policy_path:
- policy_path = get_policy()
- if not policy_path:
- sys.stderr.write("No installed policy to check\n")
- return None
outfile = tempfile.NamedTemporaryFile()
except IOError as e:
sys.stderr.write("could not open attribute output file\n")
return None
- except OSError:
- # SELinux Disabled Machine
- return None
fd = open("/dev/null", "w")
- ret = subprocess.Popen([attr_helper, policy_path, outfile.name], stdout=fd).wait()
+ if policy_path:
+ ret = subprocess.Popen([attr_helper, outfile.name, policy_path], stdout=fd).wait()
+ else:
+ ret = subprocess.Popen([attr_helper, outfile.name], stdout=fd).wait()
fd.close()
if ret != 0:
sys.stderr.write("could not run attribute helper\n")
diff --git a/python/audit2allow/sepolgen-ifgen-attr-helper.c b/python/audit2allow/sepolgen-ifgen-attr-helper.c
index 1ce37b0d..53f20818 100644
--- a/python/audit2allow/sepolgen-ifgen-attr-helper.c
+++ b/python/audit2allow/sepolgen-ifgen-attr-helper.c
@@ -26,6 +26,8 @@
#include <sepol/policydb/avtab.h>
#include <sepol/policydb/util.h>
+#include <selinux/selinux.h>
+
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
@@ -147,8 +149,36 @@ static policydb_t *load_policy(const char *filename)
policydb_t *policydb;
struct policy_file pf;
FILE *fp;
+ char pathname[PATH_MAX];
+ int suffix_ver;
int ret;
+ /* no explicit policy name given, try loaded policy on a SELinux enabled system */
+ if (!filename) {
+ filename = selinux_current_policy_path();
+ }
+
+ /*
+ * Fallback to default store paths with version suffixes,
+ * starting from the maximum supported policy version.
+ */
+ if (!filename) {
+ for (suffix_ver = sepol_policy_kern_vers_max(); suffix_ver > 0; suffix_ver--) {
+ snprintf(pathname, sizeof(pathname), "%s.%d", selinux_binary_policy_path(), suffix_ver);
+
+ if (access(pathname, F_OK) == 0) {
+ filename = pathname;
+ break;
+ }
+ }
+
+ if (!filename) {
+ fprintf(stderr, "Can't find any policy at '%s'\n",
+ selinux_binary_policy_path());
+ return NULL;
+ }
+ }
+
fp = fopen(filename, "r");
if (fp == NULL) {
fprintf(stderr, "Can't open '%s': %s\n",
@@ -188,7 +218,7 @@ static policydb_t *load_policy(const char *filename)
void usage(char *progname)
{
- printf("usage: %s policy_file out_file\n", progname);
+ printf("usage: %s out_file [policy_file]\n", progname);
}
int main(int argc, char **argv)
@@ -197,18 +227,18 @@ int main(int argc, char **argv)
struct callback_data cb_data;
FILE *fp;
- if (argc != 3) {
+ if (argc != 2 && argc != 3) {
usage(argv[0]);
return -1;
}
/* Open the policy. */
- p = load_policy(argv[1]);
+ p = load_policy(argv[2]);
if (p == NULL)
return -1;
/* Open the output policy. */
- fp = fopen(argv[2], "w");
+ fp = fopen(argv[1], "w");
if (fp == NULL) {
fprintf(stderr, "error opening output file\n");
policydb_destroy(p);
--
2.27.0
