Break DirFetchPostPeriod into:

  - DirFetchPeriod for fetching full directory,
  - StatusFetchPeriod for fetching running-routers,
  - DirPostPeriod for posting server descriptor,
  - RendPostPeriod for posting hidden service descriptors.

Also make sure the hidden service descriptors are at a random
offset from each other, to hinder linkability.


svn:r2889

4 files changed, 78 insertions, 52 deletions

diff --git a/src/or/config.c b/src/or/config.c
index 5961acd10..cf22ad1f0 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -57,6 +57,7 @@ static config_abbrev_t config_abbrevs[] = {
   { "l", "Log", 1},
   { "BandwidthRate", "BandwidthRateBytes", 0},
   { "BandwidthBurst", "BandwidthBurstBytes", 0},
+  { "DirFetchPostPeriod", "DirFetchPeriod", 0},
   { NULL, NULL , 0},
 };
 #undef PLURAL
@@ -98,7 +99,9 @@ static config_var_t config_vars[] = {
   VAR("DataDirectory",       STRING,   DataDirectory,        NULL),
   VAR("DirPort",             UINT,     DirPort,              "0"),
   VAR("DirBindAddress",      LINELIST, DirBindAddress,       NULL),
-  VAR("DirFetchPostPeriod",  UINT,     DirFetchPostPeriod,   "600"),
+  VAR("DirFetchPeriod",      UINT,     DirFetchPeriod,       "3600"),
+  VAR("DirPostPeriod",       UINT,     DirPostPeriod,        "600"),
+  VAR("RendPostPeriod",      UINT,     RendPostPeriod,       "600"),
   VAR("DirPolicy",           LINELIST, DirPolicy,            NULL),
   VAR("DirServer",           LINELIST, DirServers,           NULL),
   VAR("ExitNodes",           STRING,   ExitNodes,            NULL),
@@ -147,6 +150,7 @@ static config_var_t config_vars[] = {
   VAR("SocksPort",           UINT,     SocksPort,            "9050"),
   VAR("SocksBindAddress",    LINELIST, SocksBindAddress,     NULL),
   VAR("SocksPolicy",         LINELIST, SocksPolicy,          NULL),
+  VAR("StatusFetchPeriod",   UINT,     StatusFetchPeriod,    "1200"),
   VAR("SysLog",              LINELIST_S, OldLogOptions,      NULL),
   OBSOLETE("TrafficShaping"),
   VAR("User",                STRING,   User,                 NULL),
@@ -1227,13 +1231,25 @@ options_validate(or_options_t *options)
   }
 
 #define MIN_DIRFETCHPOSTPERIOD 60
-  if (options->DirFetchPostPeriod < MIN_DIRFETCHPOSTPERIOD) {
-    log(LOG_WARN, "DirFetchPostPeriod option must be at least %d.", MIN_DIRFETCHPOSTPERIOD);
+  if (options->DirFetchPeriod < MIN_DIRFETCHPOSTPERIOD) {
+    log(LOG_WARN, "DirFetchPeriod option must be at least %d.", MIN_DIRFETCHPOSTPERIOD);
     result = -1;
   }
-  if (options->DirFetchPostPeriod > MIN_ONION_KEY_LIFETIME / 2) {
-    log(LOG_WARN, "DirFetchPostPeriod is too large; clipping.");
-    options->DirFetchPostPeriod = MIN_ONION_KEY_LIFETIME / 2;
+  if (options->StatusFetchPeriod < MIN_DIRFETCHPOSTPERIOD) {
+    log(LOG_WARN, "StatusFetchPeriod option must be at least %d.", MIN_DIRFETCHPOSTPERIOD);
+    result = -1;
+  }
+  if (options->DirPostPeriod < MIN_DIRFETCHPOSTPERIOD) {
+    log(LOG_WARN, "DirPostPeriod option must be at least %d.", MIN_DIRFETCHPOSTPERIOD);
+    result = -1;
+  }
+  if (options->DirFetchPeriod > MIN_ONION_KEY_LIFETIME / 2) {
+    log(LOG_WARN, "DirFetchPeriod is too large; clipping.");
+    options->DirFetchPeriod = MIN_ONION_KEY_LIFETIME / 2;
+  }
+  if (options->DirPostPeriod > MIN_ONION_KEY_LIFETIME / 2) {
+    log(LOG_WARN, "DirPostPeriod is too large; clipping.");
+    options->DirPostPeriod = MIN_ONION_KEY_LIFETIME / 2;
   }
 
   if (options->KeepalivePeriod < 1) {
diff --git a/src/or/main.c b/src/or/main.c
index ab3849c73..c3de91c88 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -33,6 +33,10 @@ static uint64_t stats_n_bytes_written = 0;
 long stats_n_seconds_uptime = 0;
 /** When do we next download a directory? */
 static time_t time_to_fetch_directory = 0;
+/** When do we next upload our descriptor? */
+static time_t time_to_force_upload_descriptor = 0;
+/** When do we next download a running-routers summary? */
+static time_t time_to_fetch_running_routers = 0;
 
 /** Array of all open connections; each element corresponds to the element of
  * poll_array in the same position.  The first nfds elements are valid. */
@@ -372,12 +376,17 @@ void directory_has_arrived(time_t now) {
   log_fn(LOG_INFO, "A directory has arrived.");
 
   has_fetched_directory=1;
-  /* Don't try to upload or download anything for DirFetchPostPeriod
-   * seconds after the directory we had when we started.
+  /* Don't try to upload or download anything for a while
+   * after the directory we had when we started.
    */
   if (!time_to_fetch_directory)
-    /*XXX *5 is unreasonable.  We should have separate options for these cases.*/
-    time_to_fetch_directory = now + options->DirFetchPostPeriod*5;
+    time_to_fetch_directory = now + options->DirFetchPeriod;
+
+  if(!time_to_force_upload_descriptor)
+    time_to_force_upload_descriptor = now + options->DirPostPeriod;
+
+  if(!time_to_fetch_running_routers)
+    time_to_fetch_running_routers = now + options->StatusFetchPeriod;
 
   if (server_mode(options) &&
       !we_are_hibernating()) { /* connect to the appropriate routers */
@@ -509,12 +518,9 @@ int proxy_mode(or_options_t *options) {
  * second by prepare_for_poll.
  */
 static void run_scheduled_events(time_t now) {
-  static time_t last_uploaded_services = 0;
   static time_t last_rotated_certificate = 0;
   static time_t time_to_check_listeners = 0;
   static time_t time_to_check_descriptor = 0;
-  static time_t time_to_force_upload_descriptor = 0;
-  static time_t time_to_fetch_running_routers = 0;
   or_options_t *options = get_options();
   int i;
 
@@ -559,9 +565,9 @@ static void run_scheduled_events(time_t now) {
   if (accounting_is_enabled(options))
     accounting_run_housekeeping(now);
 
-  /** 2. Every DirFetchPostPeriod seconds, we get a new directory and
-   *    force-upload our descriptor (if we've passed our internal
-   *    checks). */
+  /** 2. Periodically, we consider getting a new directory, getting a
+   * new running-routers list, and/or force-uploading our descriptor
+   * (if we've passed our internal checks). */
   if(time_to_fetch_directory < now) {
     /* purge obsolete entries */
     routerlist_remove_old_routers(ROUTER_MAX_AGE);
@@ -577,21 +583,20 @@ static void run_scheduled_events(time_t now) {
     }
 
     directory_get_from_dirserver(DIR_PURPOSE_FETCH_DIR, NULL);
-    /*XXX *5 is unreasonable.  We should have separate options for these cases.*/
-    time_to_fetch_directory = now + options->DirFetchPostPeriod*5;
-    time_to_fetch_running_routers = now + options->DirFetchPostPeriod;
+    time_to_fetch_directory = now + options->DirFetchPeriod;
+    if (time_to_fetch_running_routers < now + options->StatusFetchPeriod) {
+      time_to_fetch_running_routers = now + options->StatusFetchPeriod;
+    }
   }
 
   if (time_to_fetch_running_routers < now) {
     if (!authdir_mode(options)) {
       directory_get_from_dirserver(DIR_PURPOSE_FETCH_RUNNING_LIST, NULL);
     }
-    time_to_fetch_running_routers = now + options->DirFetchPostPeriod;
+    time_to_fetch_running_routers = now + options->StatusFetchPeriod;
   }
 
   if (time_to_force_upload_descriptor < now) {
-    /*XXX Separate option for this, too. */
-    time_to_force_upload_descriptor = now + options->DirFetchPostPeriod;
     if(decide_if_publishable_server(now)) {
       server_is_advertised = 1;
       router_rebuild_descriptor(1);
@@ -600,14 +605,9 @@ static void run_scheduled_events(time_t now) {
       server_is_advertised = 0;
     }
 
-    if(!we_are_hibernating()) {
-      /* Force an upload of our rend descriptors every DirFetchPostPeriod seconds. */
-      rend_services_upload(1);
-      last_uploaded_services = now;
-    }
     rend_cache_clean(); /* this should go elsewhere? */
 
-    time_to_force_upload_descriptor = now + options->DirFetchPostPeriod;
+    time_to_force_upload_descriptor = now + options->DirPostPeriod;
   }
 
   /* 2b. Once per minute, regenerate and upload the descriptor if the old
@@ -625,14 +625,14 @@ static void run_scheduled_events(time_t now) {
 
   /** 3a. Every second, we examine pending circuits and prune the
    *    ones which have been pending for more than a few seconds.
-   *    We do this before step 3, so it can try building more if
+   *    We do this before step 4, so it can try building more if
    *    it's not comfortable with the number of available circuits.
    */
   circuit_expire_building(now);
 
   /** 3b. Also look at pending streams and prune the ones that 'began'
    *     a long time ago but haven't gotten a 'connected' yet.
-   *     Do this before step 3, so we can put them back into pending
+   *     Do this before step 4, so we can put them back into pending
    *     state to be picked up by the new circuit.
    */
   connection_ap_expire_beginning();
@@ -663,12 +663,9 @@ static void run_scheduled_events(time_t now) {
   /** 6. And remove any marked circuits... */
   circuit_close_all_marked();
 
-  /** 7. And upload service descriptors for any services whose intro points
-   *    have changed in the last second. */
-  if (last_uploaded_services < now-5) {
-    rend_services_upload(0);
-    last_uploaded_services = now;
-  }
+  /** 7. And upload service descriptors if necessary. */
+  if(!we_are_hibernating())
+    rend_consider_services_upload(now);
 
   /** 8. and blow away any connections that need to die. have to do this now,
    * because if we marked a conn for close and left its socket -1, then
diff --git a/src/or/or.h b/src/or/or.h
index 8ce9e901c..223ea4a84 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -924,9 +924,12 @@ typedef struct {
   int RunAsDaemon; /**< If true, run in the background. (Unix only) */
   int FascistFirewall; /**< Whether to prefer ORs reachable on open ports. */
   smartlist_t *FirewallPorts; /** Which ports our firewall allows. */
-  int DirFetchPostPeriod; /**< How often do we fetch new directories
-                           * and post server descriptros to the directory
-                           * server? */
+  int DirFetchPeriod; /**< How often do we fetch new directories? */
+  int DirPostPeriod; /**< How often do we post our server descriptor to the
+                      * authoritative directory servers? */
+  int RendPostPeriod; /**< How often do we post each rendezvous service
+                       * descriptor? Remember to publish them independently. */
+  int StatusFetchPeriod; /**< How often do we fetch running-routers lists? */
   int KeepalivePeriod; /**< How often do we send padding cells to keep
                         * connections alive? */
   int MaxOnionsPending; /**< How many circuit CREATE requests do we allow
@@ -1480,7 +1483,7 @@ int rend_config_services(or_options_t *options, int validate_only);
 int rend_service_load_keys(void);
 void rend_services_init(void);
 void rend_services_introduce(void);
-void rend_services_upload(int force);
+void rend_consider_services_upload(time_t now);
 
 void rend_service_intro_has_opened(circuit_t *circuit);
 int rend_service_intro_established(circuit_t *circuit, const char *request, size_t request_len);
diff --git a/src/or/rendservice.c b/src/or/rendservice.c
index 3bc1238d3..a38b53660 100644
--- a/src/or/rendservice.c
+++ b/src/or/rendservice.c
@@ -50,6 +50,7 @@ typedef struct rend_service_t {
                                   * established in this period. */
   rend_service_descriptor_t *desc;
   int desc_is_dirty;
+  time_t next_upload_time;
 } rend_service_t;
 
 /** A list of rend_service_t's for services run on this OP.
@@ -759,8 +760,7 @@ find_intro_circuit(routerinfo_t *router, const char *pk_digest)
   return NULL;
 }
 
-/** If the directory servers don't have an up-to-date descriptor for
- * <b>service</b>, encode and sign the service descriptor for <b>service</b>,
+/** Encode and sign an up-to-date service descriptor for <b>service</b>,
  * and upload it to all the dirservers.
  */
 static void
@@ -768,8 +768,6 @@ upload_service_descriptor(rend_service_t *service)
 {
   char *desc;
   size_t desc_len;
-  if (!service->desc_is_dirty)
-    return;
 
   /* Update the descriptor. */
   rend_service_update_descriptor(service);
@@ -893,22 +891,34 @@ void rend_services_introduce(void) {
 }
 
 /** Regenerate and upload rendezvous service descriptors for all
- * services.  If <b>force</b> is false, skip services where we've already
- * uploaded an up-to-date copy; if <b>force</b> is true, regenerate and
- * upload everything.
+ * services, if necessary. If the descriptor has been dirty enough
+ * for long enough, definitely upload; else only upload when the
+ * periodic timeout has expired.
+ *
+ * For the first upload, pick a random time between now and two periods
+ * from now, and pick it independently for each service.
  */
 void
-rend_services_upload(int force)
-{
+rend_consider_services_upload(time_t now) {
   int i;
   rend_service_t *service;
+  int rendpostperiod = get_options()->RendPostPeriod;
 
   for (i=0; i< smartlist_len(rend_service_list); ++i) {
     service = smartlist_get(rend_service_list, i);
-    if (force)
-      service->desc_is_dirty = 1;
-    if (service->desc_is_dirty)
+    if (!service->next_upload_time) { /* never been uploaded yet */
+      service->next_upload_time =
+        now + crypto_pseudo_rand_int(2*rendpostperiod);
+    }
+    if (service->next_upload_time < now ||
+        (service->desc_is_dirty &&
+         service->next_upload_time < now-5)) {
+      /* if it's time, or if the directory servers have a wrong service
+       * descriptor and this has been the case for 5 seconds, upload a
+       * new one. */
       upload_service_descriptor(service);
+      service->next_upload_time = now + rendpostperiod;
+    }
   }
 }