Add an exported struct to onion handshakes for circuits params

THis will eventually hold the congestion control parameters that we
negotiated, plus whatever else is relevant.

2 files changed, 19 insertions, 2 deletions

diff --git a/src/core/crypto/onion_crypto.c b/src/core/crypto/onion_crypto.c
index 66c21bf655..f93c2c8c58 100644
--- a/src/core/crypto/onion_crypto.c
+++ b/src/core/crypto/onion_crypto.c
@@ -183,9 +183,11 @@ onion_skin_server_handshake(int type,
                       uint8_t *reply_out,
                       size_t reply_out_maxlen,
                       uint8_t *keys_out, size_t keys_out_len,
-                      uint8_t *rend_nonce_out)
+                      uint8_t *rend_nonce_out,
+                      circuit_params_t *params_out)
 {
   int r = -1;
+  memset(params_out, 0, sizeof(*params_out)); // TODO: actually set.
 
   switch (type) {
   case ONION_HANDSHAKE_TYPE_TAP:
@@ -262,11 +264,14 @@ onion_skin_client_handshake(int type,
                       const uint8_t *reply, size_t reply_len,
                       uint8_t *keys_out, size_t keys_out_len,
                       uint8_t *rend_authenticator_out,
+                      circuit_params_t *params_out,
                       const char **msg_out)
 {
   if (handshake_state->tag != type)
     return -1;
 
+  memset(params_out, 0, sizeof(*params_out)); // TODO: actually set.
+
   switch (type) {
   case ONION_HANDSHAKE_TYPE_TAP:
     if (reply_len != TAP_ONIONSKIN_REPLY_LEN) {
diff --git a/src/core/crypto/onion_crypto.h b/src/core/crypto/onion_crypto.h
index bf25552b83..af8dd1f03f 100644
--- a/src/core/crypto/onion_crypto.h
+++ b/src/core/crypto/onion_crypto.h
@@ -22,6 +22,16 @@ typedef struct server_onion_keys_t {
 
 void onion_handshake_state_release(onion_handshake_state_t *state);
 
+/**
+ * Parameters negotiated as part of a circuit handshake.
+ */
+typedef struct circuit_params_t {
+  /* placeholder field for congestion control algorithm. Right now this
+   * is always set to zero */
+  int cc_algorithm;
+  int cc_window;
+} circuit_params_t;
+
 int onion_skin_create(int type,
                       const extend_info_t *node,
                       onion_handshake_state_t *state_out,
@@ -33,12 +43,14 @@ int onion_skin_server_handshake(int type,
                       uint8_t *reply_out,
                       size_t reply_out_maxlen,
                       uint8_t *keys_out, size_t key_out_len,
-                      uint8_t *rend_nonce_out);
+                      uint8_t *rend_nonce_out,
+                      circuit_params_t *negotiated_params_out);
 int onion_skin_client_handshake(int type,
                       const onion_handshake_state_t *handshake_state,
                       const uint8_t *reply, size_t reply_len,
                       uint8_t *keys_out, size_t key_out_len,
                       uint8_t *rend_authenticator_out,
+                      circuit_params_t *negotiated_params_out,
                       const char **msg_out);
 
 server_onion_keys_t *server_onion_keys_new(void);