Make the controller act more usefully when GETINFO fails

Right now it says "552 internal error" because there's no way for
getinfo_helper_*() countries to specify an error message.  This
patch changes the getinfo_helper_*() interface, and makes most of the
getinfo helpers give useful error messages in response to failures.

This should prevent recurrences of bug 1699, where a missing GeoIPFile
line in the torrc made GETINFO ip-to-county/* fail in a "not obvious
how to fix" way.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/or/geoip.c b/src/or/geoip.c
index ad28a77ff..7f6cf79d8 100644
--- a/src/or/geoip.c
+++ b/src/or/geoip.c
@@ -1318,10 +1318,15 @@ geoip_entry_stats_write(time_t now)
 /** Helper used to implement GETINFO ip-to-country/... controller command. */
 int
 getinfo_helper_geoip(control_connection_t *control_conn,
-                     const char *question, char **answer)
+                     const char *question, char **answer,
+                     const char **errmsg)
 {
   (void)control_conn;
-  if (geoip_is_loaded() && !strcmpstart(question, "ip-to-country/")) {
+  if (!geoip_is_loaded()) {
+    *errmsg = "GeoIP data not loaded";
+    return -1;
+  }
+  if (!strcmpstart(question, "ip-to-country/")) {
     int c;
     uint32_t ip;
     struct in_addr in;