parse: do not escape all non-ascii bytes

g_strescape will transform utf-8 strings in a sequence of escaped octal
numbers in form of a string. That happens because g_strescape will
escape the range from 0x7f to 0xff.

For example, "áéí" will become "\\303\\241\\303\\251\\303\\255". Pure
ASCII strings are not affected by it.

Add all the range 0x7f-0xff to the exception list.

src/parse.c

@@ -59,8 +59,20 @@
  * Quotes are escaped at configuration generation time as needed, as they might be part of passwords for example.
  * Escaping backslashes in the parser affects "netplan set" as it will always escape \'s from
  * the input and update YAMLs with all the \'s escaped again.
+ *
+ * g_strescape will also escape all the non-ascii chars in the range 0x7f-0xff. This affects non-ascii
+ * strings and will break utf-8 strings for example. So we add the entire range to the list of exceptions.
 */
-static char* STRESCAPE_EXCEPTIONS = "\"\\";
+static char* STRESCAPE_EXCEPTIONS =
+    "\"\\"
+    "\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91"
+    "\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3"
+    "\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5"
+    "\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7"
+    "\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9"
+    "\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb"
+    "\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd"
+    "\xfe\xff";
 
 STATIC gboolean
 insert_kv_into_hash(void *key, void *value, void *hash);

tests/ctests/test_netplan_parser.c

@@ -2,6 +2,8 @@
 #include <stdarg.h>
 #include <stddef.h>
 #include <setjmp.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
 
 #include <cmocka.h>
 #include <yaml.h>
@@ -255,6 +257,54 @@ test_nm_device_backend_is_nm_by_default(__unused void** state)
     netplan_state_clear(&np_state);
 }
 
+void
+test_parse_utf8_characters(__unused void** state)
+{
+    NetplanState *np_state = NULL;
+    int fd;
+    int size;
+    int res;
+
+    char* yaml =
+        "network:\n"
+        "  version: 2\n"
+        "  wifis:\n"
+        "    wlan0:\n"
+        "      access-points:\n"
+        "        \"áéíóúÁÉÍÓÚ\":\n"
+        "           password: \"áéíóúÁÉÍÓÚ\"\n";
+
+    char* expected =
+        "network:\n"
+        "  version: 2\n"
+        "  wifis:\n"
+        "    wlan0:\n"
+        "      access-points:\n"
+        "        \"áéíóúÁÉÍÓÚ\":\n"
+        "          auth:\n"
+        "            key-management: \"psk\"\n"
+        "            password: \"áéíóúÁÉÍÓÚ\"\n";
+
+    np_state = load_string_to_netplan_state(yaml);
+
+    fd = memfd_create("netplan-tests", 0);
+
+    netplan_state_dump_yaml(np_state, fd, NULL);
+
+    size = lseek(fd, 0, SEEK_CUR) + 1;
+    yaml = malloc(size);
+    memset(yaml, 0, size);
+    lseek(fd, 0, SEEK_SET);
+    res = read(fd, yaml, size - 1);
+    assert_true(res > 0);
+
+    assert_string_equal(yaml, expected);
+
+    netplan_state_clear(&np_state);
+    close(fd);
+    free(yaml);
+}
+
 int
 setup(__unused void** state)
 {
@@ -284,6 +334,7 @@ main()
            cmocka_unit_test(test_netplan_parser_process_document_proper_error),
            cmocka_unit_test(test_netplan_parser_process_document_missing_interface_error),
            cmocka_unit_test(test_nm_device_backend_is_nm_by_default),
+           cmocka_unit_test(test_parse_utf8_characters),
        };
 
        return cmocka_run_group_tests(tests, setup, tear_down);