Add options to control dormant-client feature.

The DormantClientTimeout option controls how long Tor will wait before
going dormant.  It also provides a way to disable the feature by setting
DormantClientTimeout to e.g. "50 years".

The DormantTimeoutDisabledByIdleStreams option controls whether open but
inactive streams count as "client activity".  To implement it, I had to
make it so that reading or writing on a client stream *always* counts as
activity.

Closes ticket 28429.

2 files changed, 16 insertions, 0 deletions

diff --git a/src/app/config/config.c b/src/app/config/config.c
index 8aa0c1f4bd..90eae50fdd 100644
--- a/src/app/config/config.c
+++ b/src/app/config/config.c
@@ -389,6 +389,8 @@ static config_var_t option_vars_[] = {
   OBSOLETE("DynamicDHGroups"),
   VPORT(DNSPort),
   OBSOLETE("DNSListenAddress"),
+  V(DormantClientTimeout,         INTERVAL, "24 hours"),
+  V(DormantTimeoutDisabledByIdleStreams, BOOL,     "1"),
   /* DoS circuit creation options. */
   V(DoSCircuitCreationEnabled,   AUTOBOOL, "auto"),
   V(DoSCircuitCreationMinConnections,      UINT, "0"),
@@ -3836,6 +3838,10 @@ options_validate(or_options_t *old_options, or_options_t *options,
            "default.");
   }
 
+  if (options->DormantClientTimeout < 10*60 && !options->TestingTorNetwork) {
+    REJECT("DormantClientTimeout is too low. It must be at least 10 minutes.");
+  }
+
   if (options->PathBiasNoticeRate > 1.0) {
     tor_asprintf(msg,
               "PathBiasNoticeRate is too high. "
diff --git a/src/app/config/or_options_st.h b/src/app/config/or_options_st.h
index 3524b99b53..6cbc86ec18 100644
--- a/src/app/config/or_options_st.h
+++ b/src/app/config/or_options_st.h
@@ -1072,6 +1072,16 @@ struct or_options_t {
 
   /** Autobool: Do we refuse single hop client rendezvous? */
   int DoSRefuseSingleHopClientRendezvous;
+
+  /** Interval: how long without activity does it take for a client
+   * to become dormant?
+   **/
+  int DormantClientTimeout;
+
+  /** Boolean: true if having an idle stream is sufficient to prevent a client
+   * from becoming dormant.
+   **/
+  int DormantTimeoutDisabledByIdleStreams;
 };
 
 #endif