Always log error if file cannot be opened

Fixes comment by @wcawijngaards on NLnetLabs/nsd#278.

Author: k0ekk0ek

src/generic/format.h

@@ -251,18 +251,8 @@ static really_inline int32_t parse_dollar_include(
   file_t *file;
   if ((code = take_quoted_or_contiguous(parser, &include, &fields[0], token)) < 0)
     return code;
-
-  switch ((code = zone_open_file(parser, token->data, token->length, &file))) {
-    case ZONE_OUT_OF_MEMORY:
-      OUT_OF_MEMORY(parser, "Cannot open %s (%.*s), out of memory",
-                    NAME(&include), (int)token->length, token->data);
-    case ZONE_NOT_PERMITTED:
-      NOT_PERMITTED(parser, "Cannot open %s (%.*s), access denied",
-                    NAME(&include), (int)token->length, token->data);
-    case ZONE_NOT_A_FILE:
-      NOT_A_FILE(parser, "Cannot open %s (%.*s), no such file",
-                 NAME(&include), (int)token->length, token->data);
-  }
+  if ((code = zone_open_file(parser, token->data, token->length, &file)) < 0)
+    return code;
 
   name_buffer_t name;
   const name_buffer_t *origin = &parser->file->origin;

src/zone.c

@@ -334,9 +334,21 @@ int32_t zone_open_file(
 
   if (!(*file = malloc(sizeof(**file))))
     return ZONE_OUT_OF_MEMORY;
-  if ((code = open_file(parser, *file, path, length)) < 0)
-    return (void)free(*file), code;
-  return 0;
+  if ((code = open_file(parser, *file, path, length)) == 0)
+    return 0;
+
+  free(*file);
+
+  const char *reason = NULL;
+  switch (code) {
+    case ZONE_OUT_OF_MEMORY: reason = "out of memory"; break;
+    case ZONE_NOT_PERMITTED: reason = "access denied"; break;
+    case ZONE_NOT_A_FILE:    reason = "no such file";  break;
+  }
+
+  assert(reason);
+  zone_error(parser, "Cannot open %.*s, %s", (int)length, path, reason);
+  return code;
 }
 
 nonnull_all
@@ -411,9 +423,19 @@ int32_t zone_open(
 
   if ((code = initialize_parser(parser, options, buffers, user_data)) < 0)
     return code;
-  if ((code = open_file(parser, &parser->first, path, strlen(path))) < 0)
-    return code;
-  return 0;
+  if ((code = open_file(parser, &parser->first, path, strlen(path))) == 0)
+    return 0;
+
+  const char *reason = NULL;
+  switch (code) {
+    case ZONE_OUT_OF_MEMORY: reason = "out of memory"; break;
+    case ZONE_NOT_PERMITTED: reason = "access denied"; break;
+    case ZONE_NOT_A_FILE:    reason = "no such file";  break;
+  }
+
+  assert(reason);
+  zone_error(parser, "Cannot open %s, %s", path, reason);
+  return code;
 }
 
 diagnostic_pop()
@@ -468,10 +490,15 @@ static void print_message(
   const char *message,
   void *user_data)
 {
-  FILE *output = priority == ZONE_INFO ? stdout : stderr;
-  const char *format = "%s:%zu: %s\n";
   (void)user_data;
-  fprintf(output, format, parser->file->name, parser->file->line, message);
+
+  assert(parser->file);
+  FILE *output = priority == ZONE_INFO ? stdout : stderr;
+
+  if (parser->file->name)
+    fprintf(output, "%s:%zu: %s\n", parser->file->name, parser->file->line, message);
+  else
+    fprintf(output, "%s\n", message);
 }
 
 void zone_vlog(

tests/include.c

@@ -284,6 +284,39 @@ static void no_such_file_log(
   test->log_count++;
 }
 
+/*!cmocka */
+void the_file_that_wasnt(void **state)
+{
+  // test parsing of nonexistent file is handled gracefully
+  zone_parser_t parser;
+  zone_options_t options;
+  zone_name_buffer_t name;
+  zone_rdata_buffer_t rdata;
+  zone_buffers_t buffers = { 1, &name, &rdata };
+  no_file_test_t test;
+  int32_t code;
+
+  memset(&options, 0, sizeof(options));
+  options.accept.callback = &no_such_file_accept;
+  options.log.callback = &no_such_file_log;
+  options.origin.octets = origin;
+  options.origin.length = sizeof(origin);
+  options.default_ttl = 3600;
+  options.default_class = 1;
+
+  (void)state;
+
+  char *non_file = temporary_name();
+  assert_non_null(non_file);
+
+  memset(&test, 0, sizeof(test));
+  code = zone_parse(&parser, &options, &buffers, non_file, &test);
+  free(non_file);
+  assert_int_equal(code, ZONE_NOT_A_FILE);
+  assert_true(test.log_count == 1);
+  assert_true(test.accept_count == 0);
+}
+
 /*!cmocka */
 void the_include_that_wasnt(void **state)
 {