Set circuitmux policy on existing active channels when ewma_enabled changes

src/or/config.c

@@ -12,6 +12,7 @@
 #define CONFIG_PRIVATE
 
 #include "or.h"
+#include "channel.h"
 #include "circuitbuild.h"
 #include "circuitlist.h"
 #include "circuitmux.h"
@@ -1169,6 +1170,7 @@ options_act(const or_options_t *old_options)
   char *msg=NULL;
   const int transition_affects_workers =
     old_options && options_transition_affects_workers(old_options, options);
+  int old_ewma_enabled;
 
   /* disable ptrace and later, other basic debugging techniques */
   {
@@ -1376,8 +1378,17 @@ options_act(const or_options_t *old_options)
     connection_bucket_init();
 #endif
 
+  old_ewma_enabled = cell_ewma_enabled();
   /* Change the cell EWMA settings */
   cell_ewma_set_scale_factor(options, networkstatus_get_latest_consensus());
+  /* If we just enabled ewma, set the cmux policy on all active channels */
+  if (cell_ewma_enabled() && !old_ewma_enabled) {
+    channel_set_cmux_policy_everywhere(&ewma_policy);
+  } else if (!cell_ewma_enabled() && old_ewma_enabled) {
+    /* Turn it off everywhere */
+    channel_set_cmux_policy_everywhere(NULL);
+  }
+
 
   /* Update the BridgePassword's hashed version as needed.  We store this as a
    * digest so that we can do side-channel-proof comparisons on it.

src/or/networkstatus.c

@@ -11,6 +11,7 @@
  */
 
 #include "or.h"
+#include "channel.h"
 #include "circuitbuild.h"
 #include "circuitmux.h"
 #include "circuitmux_ewma.h"
@@ -1636,6 +1637,7 @@ networkstatus_set_current_consensus(const char *consensus,
   consensus_waiting_for_certs_t *waiting = NULL;
   time_t current_valid_after = 0;
   int free_consensus = 1; /* Free 'c' at the end of the function */
+  int old_ewma_enabled;
 
   if (flav < 0) {
     /* XXXX we don't handle unrecognized flavors yet. */
@@ -1829,7 +1831,19 @@ networkstatus_set_current_consensus(const char *consensus,
 
     dirvote_recalculate_timing(options, now);
     routerstatus_list_update_named_server_map();
-    cell_ewma_set_scale_factor(options, current_consensus);
+
+    /* Update ewma and adjust policy if needed; first cache the old value */
+    old_ewma_enabled = cell_ewma_enabled();
+    /* Change the cell EWMA settings */
+    cell_ewma_set_scale_factor(options, networkstatus_get_latest_consensus());
+    /* If we just enabled ewma, set the cmux policy on all active channels */
+    if (cell_ewma_enabled() && !old_ewma_enabled) {
+      channel_set_cmux_policy_everywhere(&ewma_policy);
+    } else if (!cell_ewma_enabled() && old_ewma_enabled) {
+      /* Turn it off everywhere */
+      channel_set_cmux_policy_everywhere(NULL);
+    }
+
 
     /* XXXX024 this call might be unnecessary here: can changing the
      * current consensus really alter our view of any OR's rate limits? */