Implement congestion control parameter negotiation

src/core/mainloop/cpuworker.c

@@ -21,6 +21,8 @@
 #include "core/or/channel.h"
 #include "core/or/circuitlist.h"
 #include "core/or/connection_or.h"
+#include "core/or/congestion_control_common.h"
+#include "core/or/congestion_control_flow.h"
 #include "app/config/config.h"
 #include "core/mainloop/cpuworker.h"
 #include "lib/crypt_ops/crypto_rand.h"
@@ -126,6 +128,11 @@ typedef struct cpuworker_request_t {
   /** A create cell for the cpuworker to process. */
   create_cell_t create_cell;
 
+  /**
+   * A copy of this relay's consensus params that are relevant to
+   * the circuit, for use in negotiation. */
+  circuit_params_t circ_ns_params;
+
   /* Turn the above into a tagged union if needed. */
 } cpuworker_request_t;
 
@@ -381,6 +388,12 @@ cpuworker_onion_handshake_replyfn(void *work_)
     goto done_processing;
   }
 
+  /* If the client asked for congestion control, if our consensus parameter
+   * allowed it to negotiate as enabled, allocate a congestion control obj. */
+  if (rpl.circ_params.cc_enabled) {
+    TO_CIRCUIT(circ)->ccontrol = congestion_control_new(&rpl.circ_params);
+  }
+
   if (onionskin_answer(circ,
                        &rpl.created_cell,
                        (const char*)rpl.keys, sizeof(rpl.keys),
@@ -390,9 +403,6 @@ cpuworker_onion_handshake_replyfn(void *work_)
     goto done_processing;
   }
 
-  /* TODO-324! We need to use rpl.circ_params here to initialize the congestion
-     control parameters of the circuit. */
-
   log_debug(LD_OR,"onionskin_answer succeeded. Yay.");
 
  done_processing:
@@ -431,6 +441,7 @@ cpuworker_onion_handshake_threadfn(void *state_, void *work_)
   n = onion_skin_server_handshake(cc->handshake_type,
                                   cc->onionskin, cc->handshake_len,
                                   onion_keys,
+                                  &req.circ_ns_params,
                                   cell_out->reply,
                                   sizeof(cell_out->reply),
                                   rpl.keys, CPATH_KEY_MATERIAL_LEN,
@@ -559,6 +570,11 @@ assign_onionskin_to_cpuworker(or_circuit_t *circ,
   if (should_time)
     tor_gettimeofday(&req.started_at);
 
+  /* Copy the current cached consensus params relevant to
+   * circuit negotiation into the CPU worker context */
+  req.circ_ns_params.cc_enabled = congestion_control_enabled();
+  req.circ_ns_params.sendme_inc_cells = congestion_control_sendme_inc();
+
   job = tor_malloc_zero(sizeof(cpuworker_job_t));
   job->circ = circ;
   memcpy(&job->u.request, &req, sizeof(req));