r16279@catbus: nickm | 2007-10-30 11:14:29 -0400

 Improved skew reporting:  "You are 365 days in the duture" is more useful than "You are 525600 minutes in the future".  Also, when we get something that proves we are at least an hour in the past, tell the controller "CLOCK_SKEW MIN_SKEW=-3600" rather than just "CLOCK_SKEW"


svn:r12283

4 files changed, 62 insertions, 14 deletions

diff --git a/src/common/util.c b/src/common/util.c
index 27ff0c2ceb..8ee64f4522 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -1250,6 +1250,41 @@ parse_http_time(const char *date, struct tm *tm)
   return 0;
 }
 
+/** DOCDOC */
+int
+format_time_interval(char *out, size_t out_len, long interval)
+{
+  /* We only report seconds if there's no hours. */
+  long sec = 0, min = 0, hour = 0, day = 0;
+  if (interval < 0)
+    interval = -interval;
+
+  if (interval >= 86400) {
+    day = interval / 86400;
+    interval %= 86400;
+  }
+  if (interval >= 3600) {
+    hour = interval / 3600;
+    interval %= 3600;
+  }
+  if (interval >= 60) {
+    min = interval / 60;
+    interval %= 60;
+  }
+  sec = interval;
+
+  if (day) {
+    return tor_snprintf(out, out_len, "%ld days, %ld hours, %ld minutes",
+                        day, hour, min);
+  } else if (hour) {
+    return tor_snprintf(out, out_len, "%ld hours, %ld minutes", hour, min);
+  } else if (min) {
+    return tor_snprintf(out, out_len, "%ld minutes, %ld seconds", min, sec);
+  } else {
+    return tor_snprintf(out, out_len, "%ld seconds", sec);
+  }
+}
+
 /* =====
  * Fuzzy time
  * ===== */
diff --git a/src/common/util.h b/src/common/util.h
index 950de9bacc..43587af72a 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -206,6 +206,7 @@ void format_local_iso_time(char *buf, time_t t);
 void format_iso_time(char *buf, time_t t);
 int parse_iso_time(const char *buf, time_t *t);
 int parse_http_time(const char *buf, struct tm *tm);
+int format_time_interval(char *out, size_t out_len, long interval);
 /* Fuzzy time. */
 void ftime_set_maximum_sloppiness(int seconds);
 void ftime_set_estimated_skew(int seconds);
diff --git a/src/or/directory.c b/src/or/directory.c
index a780c00786..372dd27c5a 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -1250,14 +1250,18 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
      */
     delta = conn->_base.timestamp_lastwritten - date_header;
     if (abs(delta)>ALLOW_DIRECTORY_TIME_SKEW) {
+      char dbuf[64];
       int trusted = router_digest_is_trusted_dir(conn->identity_digest);
+      format_time_interval(dbuf, sizeof(dbuf), delta);
       log_fn(trusted ? LOG_WARN : LOG_INFO,
              LD_HTTP,
              "Received directory with skewed time (server '%s:%d'): "
-             "we are %d minutes %s, or the directory is %d minutes %s.",
+             "It seems that our clock is %s by %s, or that theirs is %s. "
+             "Tor requires an accurate clock to work: please check your time "
+             "and date settings.",
              conn->_base.address, conn->_base.port,
-             abs(delta)/60, delta>0 ? "ahead" : "behind",
-             abs(delta)/60, delta>0 ? "behind" : "ahead");
+             delta>0 ? "ahead" : "behind", dbuf,
+             delta>0 ? "behind" : "ahead");
       skewed = 1; /* don't check the recommended-versions line */
       control_event_general_status(trusted ? LOG_WARN : LOG_NOTICE,
                                "CLOCK_SKEW SKEW=%d SOURCE=DIRSERV:%s:%d",
diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c
index bbcc0ff6d5..7113183112 100644
--- a/src/or/networkstatus.c
+++ b/src/or/networkstatus.c
@@ -559,13 +559,16 @@ router_set_networkstatus_v2(const char *s, time_t arrived_at,
   format_iso_time(published, ns->published_on);
 
   if (ns->published_on > now + NETWORKSTATUS_ALLOW_SKEW) {
-    log_warn(LD_GENERAL, "Network status from %s was published in the future "
-             "(%s GMT). Check your system clock! "
+    char dbuf[64];
+    long delta = now - ns->published_on;
+    format_time_interval(dbuf, sizeof(dbuf), delta);
+    log_warn(LD_GENERAL, "Network status from %s was published %s in the "
+             "future (%s GMT). Check your time and date settings! "
              "Not caching.",
-             source_desc, published);
+             source_desc, dbuf, published);
     control_event_general_status(LOG_WARN,
-                                 "CLOCK_SKEW SOURCE=NETWORKSTATUS:%s:%d",
-                                 ns->source_address, ns->source_dirport);
+                       "CLOCK_SKEW MIN_SKEW=%ld SOURCE=NETWORKSTATUS:%s:%d",
+                       delta, ns->source_address, ns->source_dirport);
     skewed = 1;
   }
 
@@ -1329,12 +1332,17 @@ networkstatus_set_current_consensus(const char *consensus, int from_cache,
                                         current_consensus->valid_after);
 
   if (ftime_definitely_before(now, current_consensus->valid_after)) {
-    char buf[ISO_TIME_LEN+1];
-    format_iso_time(buf, current_consensus->valid_after);
-    log_warn(LD_GENERAL, "Consensus network status document was published "
-             "at some time in the future (%s GMT).  Check your time and date "
-             "settings!", buf);
-    control_event_general_status(LOG_WARN, "CLOCK_SKEW SOURCE=CONSENSUS");
+    char tbuf[ISO_TIME_LEN+1];
+    char dbuf[64];
+    long delta = now - current_consensus->valid_after;
+    format_iso_time(tbuf, current_consensus->valid_after);
+    format_time_interval(dbuf, sizeof(dbuf), delta);
+    log_warn(LD_GENERAL, "Our clock is %s behind the time published in the "
+             "consensus network status document (%s GMT).  Tor needs an "
+             "accurate clock to work correctly. Please check your time and "
+             "date settings!", dbuf, tbuf);
+    control_event_general_status(LOG_WARN,
+                    "CLOCK_SKEW MIN_SKEW=%ld SOURCE=CONSENSUS", delta);
   }
 
   router_dir_info_changed();