Make previous_uuid an input-only argument to hal_rpc_pkey_match().

In retrospect it's obvious that this never needed to be an
input/output argument, as its value will always be the same as the
last value in the returned array.  Doh.  So simplify the RPC and call
sequence slightly by removing the unnecessary output value.

1 files changed, 12 insertions, 5 deletions

diff --git a/rpc_client.c b/rpc_client.c
index e7e5567..959e26a 100644
--- a/rpc_client.c
+++ b/rpc_client.c
@@ -101,6 +101,16 @@ static hal_error_t read_matching_packet(const rpc_func_num_t expected_func,
 
 /*
  * RPC calls.
+ *
+ * In reading these, it helps to know that every call takes a minimum
+ * of two arguments (function code and client handle, even if the
+ * latter is just a dummy), and that every call returns a minimum of
+ * three values (function code, client handle, and return status).
+ * This may seem a bit redundant, but There Are Reasons:
+ * read_matching_packet() wants to make sure the result we're getting
+ * is from the function we thought we called, and having the client
+ * handle always present in a known place vastly simplifies the task
+ * of the client-side MUX daemon.
  */
 
 static hal_error_t get_version(uint32_t *version)
@@ -800,7 +810,7 @@ static hal_error_t pkey_remote_match(const hal_client_handle_t client,
                                      hal_uuid_t *result,
                                      unsigned *result_len,
                                      const unsigned result_max,
-                                     hal_uuid_t *previous_uuid)
+                                     const hal_uuid_t * const previous_uuid)
 {
   size_t attributes_buffer_len = 0;
   if (attributes != NULL)
@@ -809,7 +819,7 @@ static hal_error_t pkey_remote_match(const hal_client_handle_t client,
 
   uint8_t outbuf[nargs(9 + attributes_len * 2) + pad(attributes_buffer_len) + pad(sizeof(hal_uuid_t))];
   uint8_t *optr = outbuf, *olimit = outbuf + sizeof(outbuf);
-  uint8_t inbuf[nargs(5) + pad(result_max * sizeof(hal_uuid_t)) + pad(sizeof(hal_uuid_t))];
+  uint8_t inbuf[nargs(4) + pad(result_max * sizeof(hal_uuid_t))];
   const uint8_t *iptr = inbuf, *ilimit = inbuf + sizeof(inbuf);
   hal_error_t rpc_ret;
 
@@ -842,9 +852,6 @@ static hal_error_t pkey_remote_match(const hal_client_handle_t client,
       if (uuid_len != sizeof(result[i].uuid))
         return HAL_ERROR_KEY_NAME_TOO_LONG;
     }
-    check(hal_xdr_decode_buffer(&iptr, ilimit, previous_uuid->uuid, &uuid_len));
-    if (uuid_len != sizeof(previous_uuid->uuid))
-      return HAL_ERROR_KEY_NAME_TOO_LONG;
     *result_len = array_len;
   }
   return rpc_ret;