dos: Make circuit rate limit per second, not tenths anymore

Because this touches too many commits at once, it is made into one single
commit.

Remove the use of "tenths" for the circuit rate to simplify things. We can
only refill the buckets at best once every second because of the use of
approx_time() and our token system is set to be 1 token = 1 circuit so make
the rate a flat integer of circuit per second.

Signed-off-by: David Goulet <dgoulet@torproject.org>

1 files changed, 8 insertions, 24 deletions

diff --git a/src/or/dos.c b/src/or/dos.c
index 5af75ca57d..a614d12314 100644
--- a/src/or/dos.c
+++ b/src/or/dos.c
@@ -31,7 +31,7 @@ static unsigned int dos_cc_enabled = 0;
 /* Consensus parameters. They can be changed when a new consensus arrives.
  * They are initialized with the hardcoded default values. */
 static uint32_t dos_cc_min_concurrent_conn;
-static uint32_t dos_cc_circuit_rate_tenths;
+static uint32_t dos_cc_circuit_rate;
 static uint32_t dos_cc_circuit_burst;
 static dos_cc_defense_type_t dos_cc_defense_type;
 static int32_t dos_cc_defense_time_period;
@@ -93,14 +93,14 @@ get_param_cc_min_concurrent_connection(const networkstatus_t *ns)
 /* Return the parameter for the time rate that is how many circuits over this
  * time span. */
 static uint32_t
-get_param_cc_circuit_rate_tenths(const networkstatus_t *ns)
+get_param_cc_circuit_rate(const networkstatus_t *ns)
 {
   /* This is in seconds. */
-  if (get_options()->DoSCircuitCreationRateTenths) {
-    return get_options()->DoSCircuitCreationRateTenths;
+  if (get_options()->DoSCircuitCreationRate) {
+    return get_options()->DoSCircuitCreationRate;
   }
-  return networkstatus_get_param(ns, "DoSCircuitCreationRateTenths",
-                                 DOS_CC_CIRCUIT_RATE_TENTHS_DEFAULT,
+  return networkstatus_get_param(ns, "DoSCircuitCreationRate",
+                                 DOS_CC_CIRCUIT_RATE_DEFAULT,
                                  1, INT32_MAX);
 }
 
@@ -189,7 +189,7 @@ set_dos_parameters(const networkstatus_t *ns)
   /* Get the default consensus param values. */
   dos_cc_enabled = get_param_cc_enabled(ns);
   dos_cc_min_concurrent_conn = get_param_cc_min_concurrent_connection(ns);
-  dos_cc_circuit_rate_tenths = get_param_cc_circuit_rate_tenths(ns);
+  dos_cc_circuit_rate = get_param_cc_circuit_rate(ns);
   dos_cc_circuit_burst = get_param_cc_circuit_burst(ns);
   dos_cc_defense_time_period = get_param_cc_defense_time_period(ns);
   dos_cc_defense_type = get_param_cc_defense_type(ns);
@@ -225,23 +225,7 @@ cc_consensus_has_changed(const networkstatus_t *ns)
 STATIC uint32_t
 get_circuit_rate_per_second(void)
 {
-  int64_t circ_rate;
-
-  /* We take the burst divided by the rate which is in tenths of a second so
-   * convert to get a circuit rate per second. */
-  circ_rate = dos_cc_circuit_rate_tenths / 10;
-  if (circ_rate < 0) {
-    /* Safety check, never allow it to go below 0 else the bucket will always
-     * be empty resulting in every address to be detected. */
-    circ_rate = 1;
-  }
-
-  /* Clamp it down to a 32 bit value because a rate of 2^32 circuits per
-   * second is just too much in any circumstances. */
-  if (circ_rate > UINT32_MAX) {
-    circ_rate = UINT32_MAX;
-  }
-  return (uint32_t) circ_rate;
+  return dos_cc_circuit_rate;
 }
 
 /* Given the circuit creation client statistics object, refill the circuit