r14659@catbus: nickm | 2007-08-18 14:19:34 -0400

When we are loading state info from disk, never believe any date in the future.  Doing so can keep us from retrying guards, rotating onion keys, storing bandwidth info, etc.  Fixes bug 434, and others. Backport candidate, once it has been tested.


svn:r11166

ChangeLog

@@ -46,6 +46,13 @@ Changes in version 0.2.0.5-alpha - 2007-??-??
       every time we change any piece of our config.
     - Fix a bug with AutomapHostsOnResolve that would always cause the second
       request to fail.  Bug reported by Kate.  Bugfix on 0.2.0.3-alpha.
+    - When loading bandwidth history, do not believe any information in
+      the future.  Fixes bug 434.
+    - When loading entry guard information, do not believe any information
+      in the future.
+    - When we have our clock set far in the future and generate an onion key,
+      then re-set our clock to be correct, we should not stop the onion
+      key from getting rotated.
 
 
 Changes in version 0.2.0.4-alpha - 2007-08-01

src/or/circuitbuild.c

@@ -2465,6 +2465,7 @@ entry_guards_parse_state(or_state_t *state, int set, char **msg)
   entry_guard_t *node = NULL;
   smartlist_t *new_entry_guards = smartlist_create();
   config_line_t *line;
+  time_t now = time(NULL);
 
   *msg = NULL;
   for (line = state->EntryGuards; line; line = line->next) {
@@ -2507,6 +2508,11 @@ entry_guards_parse_state(or_state_t *state, int set, char **msg)
                           "Bad time in EntryGuardDownSince/UnlistedSince");
         break;
       }
+      if (when > now) {
+        /* It's a bad idea to believe info in the future: you can wind
+         * up with timeouts that aren't allowed to happen for years. */
+        continue;
+      }
       if (strlen(line->value) >= ISO_TIME_LEN+ISO_TIME_LEN+1) {
         /* ignore failure */
         parse_iso_time(line->value+ISO_TIME_LEN+1, &last_try);

src/or/hibernate.c

@@ -696,6 +696,9 @@ read_bandwidth_usage(void)
     goto done;
   }
 
+  /* XXXX020 do something if the interval "starts" far in the future?
+   * or do we alrady handle that. */
+
   n_bytes_read_in_interval = n_read;
   n_bytes_written_in_interval = n_written;
   n_seconds_active_in_interval = n_seconds;

src/or/rephist.c

@@ -993,7 +993,8 @@ rep_hist_load_state(or_state_t *state, char **err)
     s_values =  r?state->BWHistoryReadValues:state->BWHistoryWriteValues;
     if (s_values && s_begins >= now - NUM_SECS_BW_SUM_INTERVAL*NUM_TOTALS) {
       start = s_begins - s_interval*(smartlist_len(s_values));
-
+      if (start > now)
+        continue;
       b->cur_obs_time = start;
       b->next_period = start + NUM_SECS_BW_SUM_INTERVAL;
       SMARTLIST_FOREACH(s_values, char *, cp, {
@@ -1002,8 +1003,10 @@ rep_hist_load_state(or_state_t *state, char **err)
           all_ok=0;
           log_notice(LD_GENERAL, "Could not parse '%s' into a number.'", cp);
         }
-        add_obs(b, start, v);
-        start += NUM_SECS_BW_SUM_INTERVAL;
+        if (start < now) {
+          add_obs(b, start, v);
+          start += NUM_SECS_BW_SUM_INTERVAL;
+        }
       });
     }
 

src/or/router.c

@@ -332,6 +332,7 @@ init_keys(void)
   or_options_t *options = get_options();
   or_state_t *state = get_or_state();
   authority_type_t type;
+  time_t now = time(NULL);
 
   if (!key_lock)
     key_lock = tor_mutex_new();
@@ -389,14 +390,17 @@ init_keys(void)
   prkey = init_key_from_file(keydir, 1, LOG_ERR);
   if (!prkey) return -1;
   set_onion_key(prkey);
-  if (state->LastRotatedOnionKey > 100) { /* allow for some parsing slop. */
+  if (state->LastRotatedOnionKey > 100 && state->LastRotatedOnionKey < now) {
+    /* We allow for some parsing slop, but we don't want to risk accepting
+     * values in the distant future.  If we did, we might never rotate the
+     * onion key. */
     onionkey_set_at = state->LastRotatedOnionKey;
   } else {
     /* We have no LastRotatedOnionKey set; either we just created the key
      * or it's a holdover from 0.1.2.4-alpha-dev or earlier.  In either case,
      * start the clock ticking now so that we will eventually rotate it even
      * if we don't stay up for a full MIN_ONION_KEY_LIFETIME. */
-    state->LastRotatedOnionKey = onionkey_set_at = time(NULL);
+    state->LastRotatedOnionKey = onionkey_set_at = now;
     or_state_mark_dirty(state, options->AvoidDiskWrites ? time(NULL)+3600 : 0);
   }