[tor-commits] [tor/master] Merge branch 'bug1074_launch_conn_on_skew'

[nickm at torproject.org]

commit a47fdaf9a0563de4b1fff4df8aca69d9a225dd1e
Merge: a2a8ade 22810d7
Author: Nick Mathewson <nickm at torproject.org>
Date:   Fri Feb 25 12:12:44 2011 -0500

    Merge branch 'bug1074_launch_conn_on_skew'
    
    Fixed conflict on rename of router_get_by_digest->router_get_by_id_digest
    
    Conflicts:
    	src/or/command.c

 changes/launch_authcon_on_skew |    7 ++++++
 src/or/command.c               |   42 +++++++++++++++++++++++++++++++--------
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --combined src/or/command.c
index 4b70dee,e026997..a13f9ec
--- a/src/or/command.c
+++ b/src/or/command.c
@@@ -25,7 -25,6 +25,7 @@@
  #include "control.h"
  #include "cpuworker.h"
  #include "hibernate.h"
 +#include "nodelist.h"
  #include "onion.h"
  #include "relay.h"
  #include "router.h"
@@@ -45,6 -44,13 +45,13 @@@ uint64_t stats_n_destroy_cells_processe
  uint64_t stats_n_versions_cells_processed = 0;
  /** How many CELL_NETINFO cells have we received, ever? */
  uint64_t stats_n_netinfo_cells_processed = 0;
+ /** Have we received a NETINFO cell from a trusted dir, ever? Used
+  * to decide what to do about time skew.
+  * 0 == No, and and we haven't tried asking an authority yet
+  * 1 == No, we've launched a query but haven't heard back yet
+  * 2 == Yes
+  **/
+ static int received_netinfo_from_trusted_dir = 0;
  
  /* These are the main functions for processing cells */
  static void command_process_create_cell(cell_t *cell, or_connection_t *conn);
@@@ -268,18 -274,15 +275,18 @@@ command_process_create_cell(cell_t *cel
    }
  
    if (circuit_id_in_use_on_orconn(cell->circ_id, conn)) {
 -    routerinfo_t *router = router_get_by_digest(conn->identity_digest);
 +    const node_t *node = node_get_by_id(conn->identity_digest);
      log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
             "Received CREATE cell (circID %d) for known circ. "
             "Dropping (age %d).",
             cell->circ_id, (int)(time(NULL) - conn->_base.timestamp_created));
 -    if (router)
 +    if (node) {
 +      char *p = esc_for_log(node_get_platform(node));
        log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
               "Details: nickname \"%s\", platform %s.",
 -             router->nickname, escaped(router->platform));
 +             node_get_nickname(node), p);
 +      tor_free(p);
 +    }
      return;
    }
  
@@@ -621,17 -624,16 +628,16 @@@ command_process_netinfo_cell(cell_t *ce
    }
  
    /* Act on apparent skew. */
-   /** Warn when we get a netinfo skew with at least this value. */
+   /** Warn when we get a netinfo skew with at least this value.
+       Ignore if we've already received skew info from a trusted dir */
  #define NETINFO_NOTICE_SKEW 3600
    if (labs(apparent_skew) > NETINFO_NOTICE_SKEW &&
-       router_get_by_id_digest(conn->identity_digest)) {
 -      router_get_by_digest(conn->identity_digest) &&
++      router_get_by_id_digest(conn->identity_digest) &&
+       received_netinfo_from_trusted_dir != 2) {
      char dbuf[64];
-     int severity;
-     /*XXXX be smarter about when everybody says we are skewed. */
-     if (router_digest_is_trusted_dir(conn->identity_digest))
-       severity = LOG_WARN;
-     else
-       severity = LOG_INFO;
+ 
+     int severity = router_digest_is_trusted_dir(conn->identity_digest) ?
+                    LOG_WARN : LOG_INFO;
      format_time_interval(dbuf, sizeof(dbuf), apparent_skew);
      log_fn(severity, LD_GENERAL, "Received NETINFO cell with skewed time from "
             "server at %s:%d.  It seems that our clock is %s by %s, or "
@@@ -640,13 -642,31 +646,31 @@@
             conn->_base.address, (int)conn->_base.port,
             apparent_skew>0 ? "ahead" : "behind", dbuf,
             apparent_skew>0 ? "behind" : "ahead");
-     if (severity == LOG_WARN) /* only tell the controller if an authority */
+     if (severity == LOG_WARN) { /* only tell the controller if an authority */
        control_event_general_status(LOG_WARN,
                            "CLOCK_SKEW SKEW=%ld SOURCE=OR:%s:%d",
                            apparent_skew,
                            conn->_base.address, conn->_base.port);
+       received_netinfo_from_trusted_dir = 2;
+     /* Connect to a trusted dir to trigger a NETINFO cell
+      * only if we haven't already */
+     } else if (received_netinfo_from_trusted_dir == 0) {
+       routerstatus_t *any_trusted_dir =
+         router_pick_trusteddirserver(NO_AUTHORITY, 0);
+       tor_addr_t trusted_dir_addr;
+       tor_addr_from_ipv4h(&trusted_dir_addr, any_trusted_dir->addr);
+       connection_or_connect(&trusted_dir_addr,
+         any_trusted_dir->or_port,
+         any_trusted_dir->identity_digest);
+       received_netinfo_from_trusted_dir = 1;
+     }
    }
  
+   /* Note that we received a good netinfo cell from a trusted directory */
+   if (router_digest_is_trusted_dir(conn->identity_digest) &&
+       labs(apparent_skew) <= NETINFO_NOTICE_SKEW)
+     received_netinfo_from_trusted_dir = 2;
+ 
    /* XXX maybe act on my_apparent_addr, if the source is sufficiently
     * trustworthy. */