1 files changed, 102 insertions, 0 deletions
diff --git a/gr-digital/lib/digital_crc32_bb.cc b/gr-digital/lib/digital_crc32_bb.cc
new file mode 100644
index 0000000000..89d9e42151
--- /dev/null
+++ b/gr-digital/lib/digital_crc32_bb.cc
@@ -0,0 +1,102 @@
+/* -*- c++ -*- */
+/* Copyright 2012 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gr_io_signature.h>
+#include <digital_crc32.h>
+#include "digital_crc32_bb.h"
+
+digital_crc32_bb_sptr
+digital_make_crc32_bb (bool check, const std::string& lengthtagname)
+{
+  return gnuradio::get_initial_sptr (new digital_crc32_bb(check, lengthtagname));
+}
+
+
+digital_crc32_bb::digital_crc32_bb (bool check, const std::string& lengthtagname)
+  : gr_tagged_stream_block ("crc32_bb",
+		   gr_make_io_signature(1, 1, sizeof (char)),
+		   gr_make_io_signature(1, 1, sizeof (char)),
+		   lengthtagname),
+	d_check(check)
+{
+  set_tag_propagation_policy(TPP_DONT);
+}
+
+
+digital_crc32_bb::~digital_crc32_bb()
+{
+}
+
+
+int
+digital_crc32_bb::calculate_output_stream_length(const std::vector<int> &ninput_items)
+{
+  if (d_check) {
+    return ninput_items[0] - 4;
+  } else {
+    return ninput_items[0] + 4;
+  }
+}
+
+
+int
+digital_crc32_bb::work (int noutput_items,
+		       gr_vector_int &ninput_items,
+		       gr_vector_const_void_star &input_items,
+		       gr_vector_void_star &output_items)
+{
+  const unsigned char *in = (const unsigned char *) input_items[0];
+  unsigned char *out = (unsigned char *) output_items[0];
+  long packet_length = ninput_items[0];
+  int packet_size_diff = d_check ? -4 : 4;
+  unsigned int crc;
+
+  if (d_check) {
+    crc = digital_crc32(in, packet_length-4);
+    if (crc != *(unsigned int *)(in+packet_length-4)) { // Drop package
+      return 0;
+    }
+    memcpy((void *) out, (const void *) in, packet_length-4);
+  } else {
+    crc = digital_crc32(in, packet_length);
+    memcpy((void *) out, (const void *) in, packet_length);
+    memcpy((void *) (out + packet_length), &crc, 4); // FIXME big-endian/little-endian, this might be wrong
+  }
+
+  std::vector<gr_tag_t> tags;
+  get_tags_in_range(tags, 0, nitems_read(0), nitems_read(0)+packet_length);
+  for (unsigned i = 0; i < tags.size(); i++) {
+    tags[i].offset -= nitems_read(0);
+    if (d_check && tags[i].offset > packet_length+packet_size_diff) {
+      tags[i].offset = packet_length-5;
+    }
+    add_item_tag(0, nitems_written(0) + tags[i].offset,
+	tags[i].key,
+	tags[i].value);
+  }
+
+  return packet_length + packet_size_diff;
+}
+