model: Returning back support for CCNb wire format

Refs #1008 (http://redmine.named-data.net/)
diff --git a/model/wire/ccnb/ccnb-parser/syntax-tree/attr.cc b/model/wire/ccnb/ccnb-parser/syntax-tree/attr.cc
new file mode 100644
index 0000000..f661186
--- /dev/null
+++ b/model/wire/ccnb/ccnb-parser/syntax-tree/attr.cc
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include "attr.h"
+#include "../common.h"
+
+NDN_NAMESPACE_BEGIN
+
+namespace wire {
+namespace CcnbParser {
+
+// length length in octets of UTF-8 encoding of tag name - 1 (minimum tag name length is 1) 
+Attr::Attr (Buffer::Iterator &start, uint32_t length)
+{
+  m_attr.reserve (length+2); // extra byte for potential \0 at the end
+  uint32_t i = 0;
+  for (; !start.IsEnd () && i < (length+1); i++)
+    {
+      m_attr.push_back (start.ReadU8 ());
+    }
+  if (i < (length+1) && start.IsEnd ())
+    throw CcnbDecodingException ();
+  m_value = DynamicCast<Udata> (Block::ParseBlock (start));
+  if (m_value == 0)
+    throw CcnbDecodingException (); // "ATTR must be followed by UDATA field"
+}
+
+} // namespace CcnbParser
+} // namespace wire
+
+NDN_NAMESPACE_END