core: rework unit name validation and manipulation logic

A variety of changes:

- Make sure all our calls distuingish OOM from other errors if OOM is
  not the only error possible.

- Be much stricter when parsing escaped paths, do not accept trailing or
  leading escaped slashes.

- Change unit validation to take a bit mask for allowing plain names,
  instance names or template names or an combination thereof.

- Refuse manipulating invalid unit name

1 files changed, 42 insertions, 36 deletions

diff --git a/src/shared/unit-name.h b/src/shared/unit-name.h
index 6f139cc4c..057512cbd 100644
--- a/src/shared/unit-name.h
+++ b/src/shared/unit-name.h
@@ -107,61 +107,67 @@ enum UnitDependency {
         _UNIT_DEPENDENCY_INVALID = -1
 };
 
-const char *unit_type_to_string(UnitType i) _const_;
-UnitType unit_type_from_string(const char *s) _pure_;
+typedef enum UnitNameFlags {
+        UNIT_NAME_PLAIN = 1,      /* Allow foo.service */
+        UNIT_NAME_INSTANCE = 2,   /* Allow foo@bar.service */
+        UNIT_NAME_TEMPLATE = 4,   /* Allow foo@.service */
+        UNIT_NAME_ANY = UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE,
+} UnitNameFlags;
+
+bool unit_name_is_valid(const char *n, UnitNameFlags flags) _pure_;
+bool unit_prefix_is_valid(const char *p) _pure_;
+bool unit_instance_is_valid(const char *i) _pure_;
+bool unit_suffix_is_valid(const char *s) _pure_;
 
-const char *unit_load_state_to_string(UnitLoadState i) _const_;
-UnitLoadState unit_load_state_from_string(const char *s) _pure_;
+static inline int unit_prefix_and_instance_is_valid(const char *p) {
+        /* For prefix+instance and instance the same rules apply */
+        return unit_instance_is_valid(p);
+}
 
+int unit_name_to_prefix(const char *n, char **prefix);
 int unit_name_to_instance(const char *n, char **instance);
-char* unit_name_to_prefix(const char *n);
-char* unit_name_to_prefix_and_instance(const char *n);
-
-enum template_valid {
-        TEMPLATE_INVALID,
-        TEMPLATE_VALID,
-};
-
-bool unit_name_is_valid(const char *n, enum template_valid template_ok) _pure_;
-bool unit_prefix_is_valid(const char *p) _pure_;
-bool unit_instance_is_valid(const char *i) _pure_;
+int unit_name_to_prefix_and_instance(const char *n, char **ret);
 
 UnitType unit_name_to_type(const char *n) _pure_;
 
-char *unit_name_change_suffix(const char *n, const char *suffix);
+int unit_name_change_suffix(const char *n, const char *suffix, char **ret);
 
-char *unit_name_build(const char *prefix, const char *instance, const char *suffix);
+int unit_name_build(const char *prefix, const char *instance, const char *suffix, char **ret);
 
 char *unit_name_escape(const char *f);
-char *unit_name_unescape(const char *f);
-char *unit_name_path_escape(const char *f);
-char *unit_name_path_unescape(const char *f);
-
-bool unit_name_is_template(const char *n) _pure_;
-bool unit_name_is_instance(const char *n) _pure_;
+int unit_name_unescape(const char *f, char **ret);
+int unit_name_path_escape(const char *f, char **ret);
+int unit_name_path_unescape(const char *f, char **ret);
 
-char *unit_name_replace_instance(const char *f, const char *i);
+int unit_name_replace_instance(const char *f, const char *i, char **ret);
 
-char *unit_name_template(const char *f);
+int unit_name_template(const char *f, char **ret);
 
-char *unit_name_from_path(const char *path, const char *suffix);
-char *unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix);
-char *unit_name_to_path(const char *name);
+int unit_name_from_path(const char *path, const char *suffix, char **ret);
+int unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix, char **ret);
+int unit_name_to_path(const char *name, char **ret);
 
 char *unit_dbus_path_from_name(const char *name);
 int unit_name_from_dbus_path(const char *path, char **name);
 
-enum unit_name_mangle {
-        MANGLE_NOGLOB,
-        MANGLE_GLOB,
-};
+typedef enum UnitNameMangle {
+        UNIT_NAME_NOGLOB,
+        UNIT_NAME_GLOB,
+} UnitNameMangle;
 
-char *unit_name_mangle_with_suffix(const char *name, enum unit_name_mangle allow_globs, const char *suffix);
-static inline char *unit_name_mangle(const char *name, enum unit_name_mangle allow_globs) {
-        return unit_name_mangle_with_suffix(name, allow_globs, ".service");
+int unit_name_mangle_with_suffix(const char *name, UnitNameMangle allow_globs, const char *suffix, char **ret);
+
+static inline int unit_name_mangle(const char *name, UnitNameMangle allow_globs, char **ret) {
+        return unit_name_mangle_with_suffix(name, allow_globs, ".service", ret);
 }
 
-int build_subslice(const char *slice, const char*name, char **subslice);
+int slice_build_subslice(const char *slice, const char*name, char **subslice);
+
+const char *unit_type_to_string(UnitType i) _const_;
+UnitType unit_type_from_string(const char *s) _pure_;
+
+const char *unit_load_state_to_string(UnitLoadState i) _const_;
+UnitLoadState unit_load_state_from_string(const char *s) _pure_;
 
 const char *unit_dependency_to_string(UnitDependency i) _const_;
 UnitDependency unit_dependency_from_string(const char *s) _pure_;