Merge pull request #3756 from brauner/2021-03-30/fixes_3

src/lxc/confile_utils.c

@@ -667,13 +667,13 @@ int set_config_string_item_max(char **conf_item, const char *value, size_t max)
 
 int set_config_path_item(char **conf_item, const char *value)
 {
-	__do_free char *normalized = NULL;
+	__do_free char *valdup = NULL;
 
-	normalized = lxc_deslashify(value);
-	if (!normalized)
-		return syserror_set(-ENOMEM, "Failed to normalize path config item");
+	valdup = path_simplify(value);
+	if (!valdup)
+		return -ENOMEM;
 
-	return set_config_string_item_max(conf_item, normalized, PATH_MAX);
+	return set_config_string_item_max(conf_item, valdup, PATH_MAX);
 }
 
 int set_config_bool_item(bool *conf_item, const char *value, bool empty_conf_action)

src/lxc/criu.c

@@ -319,7 +319,7 @@ static int exec_criu(struct cgroup_ops *cgroup_ops, struct lxc_conf *conf,
 				return log_error_errno(-ENOMEM, ENOMEM, "Failed to duplicate limit cgroup path");
 		}
 
-		tmp = lxc_deslashify(cgroup_base_path);
+		tmp = path_simplify(cgroup_base_path);
 		if (!tmp)
 			return log_error_errno(-ENOMEM, ENOMEM, "Failed to remove extraneous slashes from \"%s\"", tmp);
 		free_move_ptr(cgroup_base_path, tmp);

src/lxc/storage/overlay.c

@@ -192,11 +192,11 @@ int ovl_clonepaths(struct lxc_storage *orig, struct lxc_storage *new, const char
 		 * don't need to record a dependency. If we would restore would
 		 * also fail.
 		 */
-		clean_old_path = lxc_deslashify(oldpath);
+		clean_old_path = path_simplify(oldpath);
 		if (!clean_old_path)
 			return log_error_errno(-ENOMEM, ENOMEM, "Failed to create clean path for \"%s\"", oldpath);
 
-		clean_new_path = lxc_deslashify(lxcpath);
+		clean_new_path = path_simplify(lxcpath);
 		if (!clean_new_path)
 			return log_error_errno(-ENOMEM, ENOMEM, "Failed to create clean path for \"%s\"", lxcpath);
 

src/lxc/string_utils.c

@@ -195,7 +195,6 @@ char *lxc_string_join(const char *sep, const char **parts, bool use_as_prefix)
 char **lxc_normalize_path(const char *path)
 {
 	char **components;
-	char **p;
 	size_t components_len = 0;
 	size_t pos = 0;
 
@@ -203,9 +202,6 @@ char **lxc_normalize_path(const char *path)
 	if (!components)
 		return NULL;
 
-	for (p = components; *p; p++)
-		components_len++;
-
 	/* resolve '.' and '..' */
 	for (pos = 0; pos < components_len;) {
 		if (strequal(components[pos], ".") ||
@@ -231,47 +227,58 @@ char **lxc_normalize_path(const char *path)
 	return components;
 }
 
-char *lxc_deslashify(const char *path)
+/* taken from systemd */
+char *path_simplify(const char *path)
 {
-	char *dup, *p;
-	char **parts = NULL;
-	size_t n, len;
+	__do_free char *path_new = NULL;
+	char *f, *t;
+	bool slash = false, ignore_slash = false, absolute;
 
-	dup = strdup(path);
-	if (!dup)
+	path_new = strdup(path);
+	if (!path_new)
 		return NULL;
 
-	parts = lxc_normalize_path(dup);
-	if (!parts) {
-		free(dup);
-		return NULL;
+	if (is_empty_string(path_new))
+		return move_ptr(path_new);
+
+	absolute = abspath(path_new);
+
+	f = path_new;
+	if (*f == '.' && IN_SET(f[1], 0, '/')) {
+		ignore_slash = true;
+		f++;
 	}
 
-	/* We'll end up here if path == "///" or path == "". */
-	if (!*parts) {
-		len = strlen(dup);
-		if (!len) {
-			lxc_free_array((void **)parts, free);
-			return dup;
-		}
+	for (t = path_new; *f; f++) {
 
-		n = strcspn(dup, "/");
-		if (n == len) {
-			free(dup);
-			lxc_free_array((void **)parts, free);
+		if (*f == '/') {
+			slash = true;
+			continue;
+		}
 
-			p = strdup("/");
-			if (!p)
-				return NULL;
+		if (slash) {
+			if (*f == '.' && IN_SET(f[1], 0, '/'))
+				continue;
 
-			return p;
+			slash = false;
+			if (ignore_slash)
+				ignore_slash = false;
+			else
+				*(t++) = '/';
 		}
+
+		*(t++) = *f;
+	}
+
+	if (t == path_new) {
+		if (absolute)
+			*(t++) = '/';
+		else
+			*(t++) = '.';
 	}
 
-	p = lxc_string_join("/", (const char **)parts, *dup == '/');
-	free(dup);
-	lxc_free_array((void **)parts, free);
-	return p;
+	*t = 0;
+	return move_ptr(path_new);
 }
 
 char *lxc_append_paths(const char *first, const char *second)

src/lxc/string_utils.h

@@ -196,4 +196,6 @@ static inline const char *fdstr(int fd)
 	     (__iterator = __it);                                               \
 	     __iterator = __it = strtok_r(NULL, __separators, &__p))
 
+__hidden extern char *path_simplify(const char *path);
+
 #endif /* __LXC_STRING_UTILS_H */

src/tests/lxc-test-utils.c

@@ -43,12 +43,12 @@
 #include "macro.h"
 #include "utils.h"
 
-void test_lxc_deslashify(void)
+void test_path_simplify(void)
 {
 	char *s = "/A///B//C/D/E/";
 	char *t;
 
-	t = lxc_deslashify(s);
+	t = path_simplify(s);
 	if (!t)
 		exit(EXIT_FAILURE);
 
@@ -57,7 +57,7 @@ void test_lxc_deslashify(void)
 
 	s = "/A";
 
-	t = lxc_deslashify(s);
+	t = path_simplify(s);
 	if (!t)
 		exit(EXIT_FAILURE);
 
@@ -65,7 +65,7 @@ void test_lxc_deslashify(void)
 	free(t);
 
 	s = "";
-	t = lxc_deslashify(s);
+	t = path_simplify(s);
 	if (!t)
 		exit(EXIT_FAILURE);
 
@@ -74,7 +74,7 @@ void test_lxc_deslashify(void)
 
 	s = "//";
 
-	t = lxc_deslashify(s);
+	t = path_simplify(s);
 	if (!t)
 		exit(EXIT_FAILURE);
 
@@ -598,7 +598,7 @@ int main(int argc, char *argv[])
 {
 	test_lxc_string_replace();
 	test_lxc_string_in_array();
-	test_lxc_deslashify();
+	test_path_simplify();
 	test_detect_ramfs_rootfs();
 	test_lxc_safe_uint();
 	test_lxc_safe_int();