Second try to move crc routines to libwsutil.

This time keep the tvb routines in epan.

Now we can use common crc routines outside epan.

svn path=/trunk/; revision=38810

1 files changed, 106 insertions, 0 deletions

diff --git a/epan/crc16-tvb.c b/epan/crc16-tvb.c
new file mode 100644
index 0000000000..d0271626f7
--- /dev/null
+++ b/epan/crc16-tvb.c
@@ -0,0 +1,106 @@
+/* crc16-tvb.c
+ * CRC-16 tvb routines
+ *
+ * 2004 Richard van der Hoff <richardv@mxtelecom.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * References:
+ *  "A Painless Guide to CRC Error Detection Algorithms", Ross Williams
+ *      http://www.repairfaq.org/filipg/LINK/F_crc_v3.html
+ *
+ *  ITU-T Recommendation V.42 (2002), "Error-Correcting Procedures for
+ *      DCEs using asynchronous-to-synchronous conversion", Para. 8.1.1.6.1
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include <epan/tvbuff.h>
+#include <wsutil/crc16.h>
+#include <wsutil/crc16-plain.h>
+
+
+guint16 crc16_ccitt_tvb(tvbuff_t *tvb, guint len)
+{
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, 0, len);
+
+    return crc16_ccitt(buf, len);
+}
+
+guint16 crc16_x25_ccitt_tvb(tvbuff_t *tvb, guint len)
+{
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, 0, len);
+
+    return crc16_x25_ccitt(buf, len);
+}
+
+guint16 crc16_ccitt_tvb_offset(tvbuff_t *tvb, guint offset, guint len)
+{
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, offset, len);
+
+    return crc16_ccitt(buf, len);
+}
+
+guint16 crc16_ccitt_tvb_seed(tvbuff_t *tvb, guint len, guint16 seed)
+{
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, 0, len);
+
+    return crc16_ccitt_seed(buf, len, seed);
+}
+
+guint16 crc16_ccitt_tvb_offset_seed(tvbuff_t *tvb, guint offset, guint len, guint16 seed)
+{
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, offset, len);
+
+    return crc16_ccitt_seed(buf, len, seed);
+}
+
+guint16 crc16_plain_tvb_offset(tvbuff_t *tvb, guint offset, guint len)
+{
+    guint16 crc = crc16_plain_init();
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, offset, len);
+
+    crc = crc16_plain_update(crc, buf, len);
+    
+    return crc16_plain_finalize(crc);
+}
+