Move protocol-specific functions out of buffers.c

This commit does not change the implementation of any function: it
only moves code and adds new includes as necessary.  Part of #23149.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/or/proto_control0.c b/src/or/proto_control0.c
new file mode 100644
index 0000000000..4c505fa6f9
--- /dev/null
+++ b/src/or/proto_control0.c
@@ -0,0 +1,27 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2017, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#define BUFFERS_PRIVATE // XXXX remove.
+#include "or.h"
+#include "buffers.h"
+#include "proto_control0.h"
+
+/** Return 1 iff buf looks more like it has an (obsolete) v0 controller
+ * command on it than any valid v1 controller command. */
+int
+peek_buf_has_control0_command(buf_t *buf)
+{
+  if (buf->datalen >= 4) {
+    char header[4];
+    uint16_t cmd;
+    peek_from_buf(header, sizeof(header), buf);
+    cmd = ntohs(get_uint16(header+2));
+    if (cmd <= 0x14)
+      return 1; /* This is definitely not a v1 control command. */
+  }
+  return 0;
+}
+