parser: Don't use the basedir global in setup_cache()

Require the caller of setup_cache() to pass in a valid cache location
string. This removes the use of the basedir global from the
policy_cache.c file.

Additionally, it is no longer necessary to return the "cache dir" path
from setup_cache() since it will always be the same as the input path.
The return value is changed to an int so an error code can be returned
instead of using exit().

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>

parser/parser_main.c

@@ -877,7 +877,6 @@ static void setup_flags(void)
 
 int main(int argc, char *argv[])
 {
-	autofree char *cachedir = NULL;
 	int retval, last_error;
 	int i;
 	int optind;
@@ -910,7 +909,17 @@ int main(int argc, char *argv[])
 
 	setup_flags();
 
-	cachedir = setup_cache(cacheloc);
+	if (!cacheloc && asprintf(&cacheloc, "%s/cache", basedir) == -1) {
+		PERROR(_("Memory allocation error."));
+		return 1;
+	}
+
+	retval = setup_cache(cacheloc);
+	if (retval) {
+		PERROR(_("Failed setting up policy cache (%s): %s\n"),
+		       cacheloc, strerror(errno));
+		return 1;
+	}
 
 	retval = last_error = 0;
 	for (i = optind; i <= argc; i++) {
@@ -938,7 +947,7 @@ int main(int argc, char *argv[])
 			struct dir_cb_data cb_data;
 
 			cb_data.dirname = profilename;
-			cb_data.cachedir = cachedir;
+			cb_data.cachedir = cacheloc;
 			cb = binary_input ? binary_dir_cb : profile_dir_cb;
 			if ((retval = dirat_for_each(NULL, profilename,
 						     &cb_data, cb))) {
@@ -948,7 +957,7 @@ int main(int argc, char *argv[])
 		} else if (binary_input) {
 			retval = process_binary(option, profilename);
 		} else {
-			retval = process_profile(option, profilename, cachedir);
+			retval = process_profile(option, profilename, cacheloc);
 		}
 
 		if (profilename) free(profilename);

parser/policy_cache.c

@@ -228,27 +228,18 @@ void install_cache(const char *cachetmpname, const char *cachename)
 	}
 }
 
-char *setup_cache(const char *cacheloc)
+int setup_cache(const char *cacheloc)
 {
 	autofree char *cache_features_path = NULL;
 	autofree char *cache_flags = NULL;
-	char *cachedir;
 
-	if (cacheloc) {
+	if (!cacheloc) {
-		cachedir = strdup(cacheloc);
+		errno = EINVAL;
-		if (!cachedir) {
+		return -1;
-			PERROR(_("Memory allocation error."));
-			exit(1);
-		}
-	} else {
-		if (asprintf(&cachedir, "%s/cache", basedir) == -1) {
-			PERROR(_("Memory allocation error."));
-			exit(1);
-		}
 	}
 
 	if (force_clear_cache)
-		exit(clear_cache_files(cachedir));
+		exit(clear_cache_files(cacheloc));
 
 	/*
          * Deal with cache directory versioning:
@@ -256,16 +247,17 @@ char *setup_cache(const char *cacheloc)
          *  - If cache/.features exists, and does not match features_string,
          *    force cache reading/writing off.
          */
-	if (asprintf(&cache_features_path, "%s/.features", cachedir) == -1) {
+	if (asprintf(&cache_features_path, "%s/.features", cacheloc) == -1) {
 		PERROR(_("Memory allocation error."));
-		exit(1);
+		errno = ENOMEM;
+		return -1;
 	}
 
 	cache_flags = load_features_file(cache_features_path);
 	if (cache_flags) {
 		if (strcmp(features_string, cache_flags) != 0) {
 			if (write_cache && cond_clear_cache) {
-				if (create_cache(cachedir, cache_features_path,
+				if (create_cache(cacheloc, cache_features_path,
 						 features_string))
 					skip_read_cache = 1;
 			} else {
@@ -276,8 +268,8 @@ char *setup_cache(const char *cacheloc)
 			}
 		}
 	} else if (write_cache) {
-		create_cache(cachedir, cache_features_path, features_string);
+		create_cache(cacheloc, cache_features_path, features_string);
 	}
 
-	return cachedir;
+	return 0;
 }

parser/policy_cache.h

@@ -46,6 +46,6 @@ void valid_read_cache(const char *cachename);
 int cache_hit(const char *cachename);
 int setup_cache_tmp(const char **cachetmpname, const char *cachename);
 void install_cache(const char *cachetmpname, const char *cachename);
-char *setup_cache(const char *cacheloc);
+int setup_cache(const char *cacheloc);
 
 #endif /* __AA_POLICY_CACHE_H */