Make CacheDirectoryGroupReadable an autobool.

Since the default cache directory is the same as the default data
directory, we don't want the default CacheDirectoryGroupReadable
value (0) to override an explicitly set "DataDirectoryGroupReadable
1".

To fix this, I'm making CacheDirectoryGroupReadable into an
autobool, and having the default (auto) value mean "Use the value of
DataDirectoryGroupReadable if the directories are the same, and 0
otherwise."

Fixes bug 26913; bugfix on 0.3.3.1-alpha when the CacheDirectory
option was introduced.

1 files changed, 19 insertions, 2 deletions

diff --git a/src/or/config.c b/src/or/config.c
index 58080c65e3..e50e6efa20 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -259,7 +259,7 @@ static config_var_t option_vars_[] = {
   V(BridgeRelay,                 BOOL,     "0"),
   V(BridgeDistribution,          STRING,   NULL),
   VAR("CacheDirectory",          FILENAME, CacheDirectory_option, NULL),
-  V(CacheDirectoryGroupReadable, BOOL,     "0"),
+  V(CacheDirectoryGroupReadable, AUTOBOOL,     "auto"),
   V(CellStatistics,              BOOL,     "0"),
   V(PaddingStatistics,           BOOL,     "1"),
   V(LearnCircuitBuildTimeout,    BOOL,     "1"),
@@ -1516,9 +1516,26 @@ options_act_reversible(const or_options_t *old_options, char **msg)
                                       msg) < 0) {
     goto done;
   }
+
+  /* We need to handle the group-readable flag for the cache directory
+   * specially, since the directory defaults to being the same as the
+   * DataDirectory. */
+  int cache_dir_group_readable;
+  if (options->CacheDirectoryGroupReadable != -1) {
+    /* If the user specified a value, use their setting */
+    cache_dir_group_readable = options->CacheDirectoryGroupReadable;
+  } else if (!strcmp(options->CacheDirectory, options->DataDirectory)) {
+    /* If the user left the value as "auto", and the cache is the same as the
+     * datadirectory, use the datadirectory setting.
+     */
+    cache_dir_group_readable = options->DataDirectoryGroupReadable;
+  } else {
+    /* Otherwise, "auto" means "not group readable". */
+    cache_dir_group_readable = 0;
+  }
   if (check_and_create_data_directory(running_tor /* create */,
                                       options->CacheDirectory,
-                                      options->CacheDirectoryGroupReadable,
+                                      cache_dir_group_readable,
                                       options->User,
                                       msg) < 0) {
     goto done;