libsemanage: Use pp module name instead of filename

When a user installs a module, the filename is used as the module name.
This change was introduced with CIL language where a module name is not
stored in the module itself. It means that when a pp module has
different filename and stored module name, the filename is used instead
of the stored module name. It brings problems with compatibility for
scripts and modules which were built and used on older system and were
migrated to the new userspace.

This patch changes the behavior of semanage_direct_install_file() which
is used by 'semodule -i' so that when a module with pp language
extension is installed, it tries to get and use a stored module name
instead of a filename. A warning message is provided.

The warning message in policycoreutils/hll/pp is updated to reflect this
change:

$ semodule -X 400 -i /root/testfile.pp
Warning: SELinux userspace will refer to the module from /root/testfile.pp as testmod rather than testfile

$ /usr/libexec/selinux/hll/pp /root/testfile.pp testfile.cil
Warning: SELinux userspace will refer to the module from /root/testfile.pp as testmod rather than testfile

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>

libsemanage/src/direct_api.c

@@ -363,6 +363,48 @@ static int semanage_direct_begintrans(semanage_handle_t * sh)
 
 /********************* utility functions *********************/
 
+/* Takes a module stored in 'module_data' and parses its headers.
+ * Sets reference variables 'module_name' to module's name, and
+ * 'version' to module's version.  The caller is responsible for
+ * free()ing 'module_name', and 'version'; they will be
+ * set to NULL upon entering this function.  Returns 0 on success, -1
+ * if out of memory, or -2 if data did not represent a module.
+ */
+static int parse_module_headers(semanage_handle_t * sh, char *module_data,
+                               size_t data_len, char **module_name,
+                               char **version)
+{
+       struct sepol_policy_file *pf;
+       int file_type;
+       *module_name = *version = NULL;
+
+       if (sepol_policy_file_create(&pf)) {
+               ERR(sh, "Out of memory!");
+               return -1;
+       }
+       sepol_policy_file_set_mem(pf, module_data, data_len);
+       sepol_policy_file_set_handle(pf, sh->sepolh);
+       if (module_data == NULL ||
+           data_len == 0 ||
+           sepol_module_package_info(pf, &file_type, module_name,
+                                     version) == -1) {
+               sepol_policy_file_free(pf);
+               ERR(sh, "Could not parse module data.");
+               return -2;
+       }
+       sepol_policy_file_free(pf);
+       if (file_type != SEPOL_POLICY_MOD) {
+               if (file_type == SEPOL_POLICY_BASE)
+                       ERR(sh,
+                           "Received a base module, expected a non-base module.");
+               else
+                       ERR(sh, "Data did not represent a module.");
+               return -2;
+       }
+
+       return 0;
+}
+
 #include <stdlib.h>
 #include <bzlib.h>
 #include <string.h>
@@ -1524,7 +1566,9 @@ static int semanage_direct_install_file(semanage_handle_t * sh,
 	char *path = NULL;
 	char *filename;
 	char *lang_ext = NULL;
+	char *module_name = NULL;
 	char *separator;
+	char *version = NULL;
 
 	if ((data_len = map_file(sh, install_filename, &data, &compressed)) <= 0) {
 		ERR(sh, "Unable to read file %s\n", install_filename);
@@ -1564,10 +1608,25 @@ static int semanage_direct_install_file(semanage_handle_t * sh,
 		lang_ext = separator + 1;
 	}
 
-	retval = semanage_direct_install(sh, data, data_len, filename, lang_ext);
+	if (strcmp(lang_ext, "pp") != 0) {
+		module_name = strdup(filename);
+		if (module_name == NULL) {
+			ERR(sh, "No memory available for module_name.\n");
+			retval = -1;
+			goto cleanup;
+		}
+	} else {
+		if ((retval = parse_module_headers(sh, data, data_len, &module_name, &version)) != 0)
+			goto cleanup;
+
+		fprintf(stderr, "Warning: SELinux userspace will refer to the module from %s as %s rather than %s\n", install_filename, module_name, filename);
+		free(version);
+	}
+	retval = semanage_direct_install(sh, data, data_len, module_name, lang_ext);
 
 cleanup:
 	if (data_len > 0) munmap(data, data_len);
+	free(module_name);
 	free(path);
 
 	return retval;

policycoreutils/hll/pp/pp.c

@@ -142,7 +142,7 @@ int main(int argc, char **argv)
 			*separator = '\0';
 		}
 		if (strcmp(mod_name, cil_name) != 0) {
-			fprintf(stderr,	"Warning: SELinux userspace will refer to the module from %s as %s rather than %s\n", ifile, cil_name, mod_name);
+			fprintf(stderr,	"Warning: SELinux userspace will refer to the module from %s as %s rather than %s\n", ifile, mod_name, cil_name);
 		}
 		free(cil_path);
 	}