Merge branch 'maint-0.2.2'

Conflicts:
	src/or/dirserv.c

7 files changed, 62 insertions, 14 deletions

diff --git a/changes/bug4518 b/changes/bug4518
new file mode 100644
index 0000000000..8dcb93bf72
--- /dev/null
+++ b/changes/bug4518
@@ -0,0 +1,4 @@
+  o Minor bugfixes (performance):
+    - Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
+      function. This was eating up hideously large amounts of time on some
+      busy servers. Fixes bug 4518.
diff --git a/changes/feature4484 b/changes/feature4484
new file mode 100644
index 0000000000..78154e9649
--- /dev/null
+++ b/changes/feature4484
@@ -0,0 +1,8 @@
+  o Minor features:
+    - Add two new config options for directory authorities:
+      AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
+      Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
+      that is always sufficient to satisfy the bandwidth requirement for
+      the Guard flag. Now it will be easier for researchers to simulate
+      Tor networks with different values. Resolves ticket 4484.
+
diff --git a/doc/tor.1.txt b/doc/tor.1.txt
index b54735d383..bc0435d4d9 100644
--- a/doc/tor.1.txt
+++ b/doc/tor.1.txt
@@ -1406,6 +1406,16 @@ DIRECTORY AUTHORITY SERVER OPTIONS
     Authoritative directories only. Like AuthDirMaxServersPerAddr, but applies
     to addresses shared with directory authorities. (Default: 5)
 
+**AuthDirFastGuarantee** __N__ **bytes**|**KB**|**MB**|**GB**::
+    Authoritative directories only. If non-zero, always vote the
+    Fast flag for any relay advertising this amount of capacity or
+    more. (Default: 20 KB)
+
+**AuthDirGuardBWGuarantee** __N__ **bytes**|**KB**|**MB**|**GB**::
+    Authoritative directories only. If non-zero, this advertised capacity
+    or more is always sufficient to satisfy the bandwidth requirement
+    for the Guard flag. (Default: 250 KB)
+
 **BridgePassword** __Password__::
     If set, contains an HTTP authenticator that tells a bridge authority to
     serve all requested bridge information.  Used for debugging.  (Default:
diff --git a/src/or/config.c b/src/or/config.c
index afccf2e84e..7cbadc25c3 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -184,6 +184,8 @@ static config_var_t _option_vars[] = {
   V(AuthDirBadDir,               LINELIST, NULL),
   V(AuthDirBadExit,              LINELIST, NULL),
   V(AuthDirInvalid,              LINELIST, NULL),
+  V(AuthDirFastGuarantee,        MEMUNIT,  "20 KB"),
+  V(AuthDirGuardBWGuarantee,     MEMUNIT,  "250 KB"),
   V(AuthDirReject,               LINELIST, NULL),
   V(AuthDirRejectUnlisted,       BOOL,     "0"),
   V(AuthDirListBadDirs,          BOOL,     "0"),
@@ -3544,6 +3546,12 @@ options_validate(or_options_t *old_options, or_options_t *options,
   if (ensure_bandwidth_cap(&options->PerConnBWBurst,
                            "PerConnBWBurst", msg) < 0)
     return -1;
+  if (ensure_bandwidth_cap(&options->AuthDirFastGuarantee,
+                           "AuthDirFastGuarantee", msg) < 0)
+    return -1;
+  if (ensure_bandwidth_cap(&options->AuthDirGuardBWGuarantee,
+                           "AuthDirGuardBWGuarantee", msg) < 0)
+    return -1;
 
   if (options->RelayBandwidthRate && !options->RelayBandwidthBurst)
     options->RelayBandwidthBurst = options->RelayBandwidthRate;
diff --git a/src/or/cpuworker.c b/src/or/cpuworker.c
index bf8964c29c..914003790a 100644
--- a/src/or/cpuworker.c
+++ b/src/or/cpuworker.c
@@ -445,9 +445,19 @@ assign_onionskin_to_cpuworker(connection_t *cpuworker,
 {
   char qbuf[1];
   char tag[TAG_LEN];
+  time_t now = approx_time();
+  static time_t last_culled_cpuworkers = 0;
 
-  cull_wedged_cpuworkers();
-  spawn_enough_cpuworkers();
+  /* Checking for wedged cpuworkers requires a linear search over all
+   * connections, so let's do it only once a minute.
+   */
+#define CULL_CPUWORKERS_INTERVAL 60
+
+  if (last_culled_cpuworkers + CULL_CPUWORKERS_INTERVAL <= now) {
+    cull_wedged_cpuworkers();
+    spawn_enough_cpuworkers();
+    last_culled_cpuworkers = now;
+  }
 
   if (1) {
     if (num_cpuworkers_busy == num_cpuworkers) {
diff --git a/src/or/dirserv.c b/src/or/dirserv.c
index e4cbcaaded..64db94df31 100644
--- a/src/or/dirserv.c
+++ b/src/or/dirserv.c
@@ -1720,12 +1720,6 @@ should_generate_v2_networkstatus(void)
 /** If a router's MTBF is at least this value, then it is always stable.
  * See above.  (Corresponds to about 7 days for current decay rates.) */
 #define MTBF_TO_GUARANTEE_STABLE (60*60*24*5)
-/** Similarly, we protect sufficiently fast nodes from being pushed
- * out of the set of Fast nodes. */
-#define BANDWIDTH_TO_GUARANTEE_FAST ROUTER_REQUIRED_MIN_BANDWIDTH
-/** Similarly, every node with sufficient bandwidth can be considered
- * for Guard status. */
-#define BANDWIDTH_TO_GUARANTEE_GUARD (250*1024)
 /** Similarly, every node with at least this much weighted time known can be
  * considered familiar enough to be a guard.  Corresponds to about 20 days for
  * current decay rates.
@@ -1870,6 +1864,7 @@ dirserv_compute_performance_thresholds(routerlist_t *rl)
   long *tks;
   double *mtbfs, *wfus;
   time_t now = time(NULL);
+  or_options_t *options = get_options();
 
   /* initialize these all here, in case there are no routers */
   stable_uptime = 0;
@@ -1942,8 +1937,11 @@ dirserv_compute_performance_thresholds(routerlist_t *rl)
   if (guard_tk > TIME_KNOWN_TO_GUARANTEE_FAMILIAR)
     guard_tk = TIME_KNOWN_TO_GUARANTEE_FAMILIAR;
 
-  if (fast_bandwidth > BANDWIDTH_TO_GUARANTEE_FAST)
-    fast_bandwidth = BANDWIDTH_TO_GUARANTEE_FAST;
+  /* Protect sufficiently fast nodes from being pushed out of the set
+   * of Fast nodes. */
+  if (options->AuthDirFastGuarantee &&
+      fast_bandwidth > options->AuthDirFastGuarantee)
+    fast_bandwidth = options->AuthDirFastGuarantee;
 
   /* Now that we have a time-known that 7/8 routers are known longer than,
    * fill wfus with the wfu of every such "familiar" router. */
@@ -2375,6 +2373,8 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs,
   const or_options_t *options = get_options();
   int unstable_version =
     !tor_version_as_new_as(ri->platform,"0.1.1.16-rc-cvs");
+  uint32_t routerbw = router_get_advertised_bandwidth(ri);
+
   memset(rs, 0, sizeof(routerstatus_t));
 
   rs->is_authority =
@@ -2400,10 +2400,10 @@ set_routerstatus_from_routerinfo(routerstatus_t *rs,
   rs->is_valid = node->is_valid;
 
   if (node->is_fast &&
-      (router_get_advertised_bandwidth(ri) >= BANDWIDTH_TO_GUARANTEE_GUARD ||
-       router_get_advertised_bandwidth(ri) >=
-                              MIN(guard_bandwidth_including_exits,
-                                  guard_bandwidth_excluding_exits)) &&
+      ((options->AuthDirGuardBWGuarantee &&
+        routerbw >= options->AuthDirGuardBWGuarantee) ||
+       routerbw >= MIN(guard_bandwidth_including_exits,
+                       guard_bandwidth_excluding_exits)) &&
       (options->GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays ||
        is_router_version_good_for_possible_guard(ri->platform))) {
     long tk = rep_hist_get_weighted_time_known(
diff --git a/src/or/or.h b/src/or/or.h
index 259ae5c989..67ba62bdd6 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3162,6 +3162,14 @@ typedef struct {
    * exploitation of CVE-2011-2768 against their clients? */
   int GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays;
 
+  /** If non-zero, always vote the Fast flag for any relay advertising
+   * this amount of capacity or more. */
+  uint64_t AuthDirFastGuarantee;
+
+  /** If non-zero, this advertised capacity or more is always sufficient
+   * to satisfy the bandwidth requirement for the Guard flag. */
+  uint64_t AuthDirGuardBWGuarantee;
+
   char *AccountingStart; /**< How long is the accounting interval, and when
                           * does it start? */
   uint64_t AccountingMax; /**< How many bytes do we allow per accounting