[PATCH v2 4/4] semodule_unpackage: update

["Christian Göttsche" <cgzones@googlemail.com>]

Drop unnecessary declarations.
Check closing file for incomplete write.
Rework resource cleanup, so that all files and allocated memory are
released in all branches, useful to minimize reports while debugging
libsepol under valgrind(8) or sanitizers.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
v2:
address comments from Jim
  * drop exit() calls
  * reduce to one final return statement
  * drop global variable progname
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
 .../semodule_package/semodule_unpackage.c     | 129 +++++++++++-------
 1 file changed, 77 insertions(+), 52 deletions(-)

diff --git a/semodule-utils/semodule_package/semodule_unpackage.c b/semodule-utils/semodule_package/semodule_unpackage.c
index b8c4fbce..d5b84068 100644
--- a/semodule-utils/semodule_package/semodule_unpackage.c
+++ b/semodule-utils/semodule_package/semodule_unpackage.c
@@ -11,46 +11,23 @@
 #include <fcntl.h>
 #include <errno.h>
 
-char *progname = NULL;
-extern char *optarg;
-
-static __attribute__((__noreturn__)) void usage(void)
+static void usage(const char *progname)
 {
 	printf("usage: %s ppfile modfile [fcfile]\n", progname);
-	exit(1);
-}
-
-static int file_to_policy_file(const char *filename, struct sepol_policy_file **pf, const char *mode)
-{
-	FILE *f;
-
-	if (sepol_policy_file_create(pf)) {
-		fprintf(stderr, "%s:  Out of memory\n", progname);
-		return -1;
-	}
-
-	f = fopen(filename, mode);
-	if (!f) {
-		fprintf(stderr, "%s:  Could not open file %s:  %s\n", progname, strerror(errno), filename);
-		return -1;
-	}
-	sepol_policy_file_set_fp(*pf, f);
-	return 0;
 }
 
 int main(int argc, char **argv)
 {
-	struct sepol_module_package *pkg;
-	struct sepol_policy_file *in, *out;
-	FILE *fp;
+	struct sepol_module_package *pkg = NULL;
+	struct sepol_policy_file *in = NULL, *out = NULL;
+	FILE *fp = NULL;
 	size_t len;
-	char *ppfile, *modfile, *fcfile = NULL, *fcdata;
-
-	progname = argv[0];
+	const char *ppfile, *modfile, *fcfile = NULL, *fcdata;
+	int ret;
 
 	if (argc < 3) {
-		usage();
-		exit(1);
+		usage(argv[0]);
+		return EXIT_FAILURE;
 	}
 
 	ppfile = argv[1];
@@ -58,46 +35,94 @@ int main(int argc, char **argv)
 	if (argc >= 4)
 		fcfile = argv[3];
 
-	if (file_to_policy_file(ppfile, &in, "r"))
-		exit(1);
-
 	if (sepol_module_package_create(&pkg)) {
-                fprintf(stderr, "%s:  Out of memory\n", progname);
-                exit(1);
+		fprintf(stderr, "%s:  Out of memory\n", argv[0]);
+		goto failure;
 	}
 
-	if (sepol_module_package_read(pkg, in, 0) == -1) {
-                fprintf(stderr, "%s:  Error while reading policy module from %s\n",
-			progname, ppfile);
-                exit(1);
+	if (sepol_policy_file_create(&in)) {
+		fprintf(stderr, "%s:  Out of memory\n", argv[0]);
+		goto failure;
 	}
 
-	if (file_to_policy_file(modfile, &out, "w"))
-		exit(1);
+	fp = fopen(ppfile, "r");
+	if (!fp) {
+		fprintf(stderr, "%s:  Could not open file %s:  %s\n", argv[0], ppfile, strerror(errno));
+		goto failure;
+	}
+	sepol_policy_file_set_fp(in, fp);
 
-        if (sepol_policydb_write(sepol_module_package_get_policy(pkg), out)) {
-                fprintf(stderr, "%s:  Error while writing module to %s\n", progname, modfile);
-                exit(1);
-        }
+	if (sepol_module_package_read(pkg, in, 0) == -1) {
+		fprintf(stderr, "%s:  Error while reading policy module from %s\n",
+			argv[0], ppfile);
+		goto failure;
+	}
 
 	sepol_policy_file_free(in);
+	in = NULL;
+	fclose(fp);
+	fp = NULL;
+
+	if (sepol_policy_file_create(&out)) {
+		fprintf(stderr, "%s:  Out of memory\n", argv[0]);
+		goto failure;
+	}
+
+	fp = fopen(modfile, "w");
+	if (!fp) {
+		fprintf(stderr, "%s:  Could not open file %s:  %s\n", argv[0], modfile, strerror(errno));
+		goto failure;
+	}
+	sepol_policy_file_set_fp(out, fp);
+
+	if (sepol_policydb_write(sepol_module_package_get_policy(pkg), out)) {
+		fprintf(stderr, "%s:  Error while writing module to %s\n", argv[0], modfile);
+		goto failure;
+	}
+
+	ret = fclose(fp);
+	fp = NULL;
+	if (ret) {
+		fprintf(stderr, "%s:  Error while closing file %s:  %s\n", argv[0], modfile, strerror(errno));
+		goto failure;
+	}
+
 	sepol_policy_file_free(out);
+	out = NULL;
 
 	len = sepol_module_package_get_file_contexts_len(pkg);
 	if (fcfile && len) {
 		fp = fopen(fcfile, "w");
 		if (!fp) {
-			fprintf(stderr, "%s:  Could not open file %s:  %s\n", progname, strerror(errno), fcfile);
-			exit(1);
+			fprintf(stderr, "%s:  Could not open file %s:  %s\n", argv[0], fcfile, strerror(errno));
+			goto failure;
 		}
 		fcdata = sepol_module_package_get_file_contexts(pkg);
 		if (fwrite(fcdata, 1, len, fp) != len) {
-			fprintf(stderr, "%s:  Could not write file %s:  %s\n", progname, strerror(errno), fcfile);
-			exit(1);
+			fprintf(stderr, "%s:  Could not write file %s:  %s\n", argv[0], fcfile, strerror(errno));
+			goto failure;
+		}
+
+		ret = fclose(fp);
+		fp = NULL;
+		if (ret) {
+			fprintf(stderr, "%s:  Could not close file %s:  %s\n", argv[0], fcfile, strerror(errno));
+			goto failure;
 		}
-		fclose(fp);
 	}
 
+	ret = EXIT_SUCCESS;
+	goto cleanup;
+
+failure:
+	ret = EXIT_FAILURE;
+
+cleanup:
+	if (fp)
+		fclose(fp);
+	sepol_policy_file_free(out);
 	sepol_module_package_free(pkg);
-	exit(0);
+	sepol_policy_file_free(in);
+
+	return ret;
 }
-- 
2.40.1