/* packet-lapb.c
* Routines for lapb frame disassembly
- * Olivier Abad <abad@daba.dhis.org>
+ * Olivier Abad <oabad@noos.fr>
*
- * $Id: packet-lapb.c,v 1.4 1999/08/20 06:55:07 guy Exp $
+ * $Id: packet-lapb.c,v 1.40 2003/09/26 08:19:55 guy Exp $
*
* Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
* Copyright 1998
*
- *
* 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.
# include "config.h"
#endif
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-
#include <stdio.h>
#include <glib.h>
#include <string.h>
-#include "packet.h"
+#include <epan/packet.h>
#include "xdlc.h"
-#define FROM_DCE 0x80
+static int proto_lapb = -1;
+static int hf_lapb_address = -1;
+static int hf_lapb_control = -1;
-int proto_lapb = -1;
-int hf_lapb_address = -1;
-int hf_lapb_control = -1;
+static gint ett_lapb = -1;
+static gint ett_lapb_control = -1;
-void
-dissect_lapb(const u_char *pd, frame_data *fd, proto_tree *tree)
+static dissector_handle_t x25_dir_handle;
+static dissector_handle_t x25_handle;
+
+static void
+dissect_lapb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
- proto_tree *lapb_tree, *ti;
- int is_response;
-
- if (check_col(fd, COL_PROTOCOL))
- col_add_str(fd, COL_PROTOCOL, "LAPB");
-
- if(check_col(fd, COL_RES_DL_SRC))
- col_add_fstr(fd, COL_RES_DL_SRC, "0x%02X", pd[0]);
- if (fd->pseudo_header.x25.flags & FROM_DCE) {
- if(check_col(fd, COL_RES_DL_DST))
- col_add_str(fd, COL_RES_DL_DST, "DTE");
- if(check_col(fd, COL_RES_DL_SRC))
- col_add_str(fd, COL_RES_DL_SRC, "DCE");
+ proto_tree *lapb_tree, *ti;
+ int is_response;
+ guint8 byte0;
+ tvbuff_t *next_tvb;
+
+ if (check_col(pinfo->cinfo, COL_PROTOCOL))
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "LAPB");
+ if (check_col(pinfo->cinfo, COL_INFO))
+ col_clear(pinfo->cinfo, COL_INFO);
+
+ switch (pinfo->p2p_dir) {
+
+ case P2P_DIR_SENT:
+ if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
+ col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
+ if(check_col(pinfo->cinfo, COL_RES_DL_DST))
+ col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
+ break;
+
+ case P2P_DIR_RECV:
+ if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
+ col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
+ if(check_col(pinfo->cinfo, COL_RES_DL_DST))
+ col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
+ break;
+
+ default:
+ if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
+ col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "N/A");
+ if(check_col(pinfo->cinfo, COL_RES_DL_DST))
+ col_set_str(pinfo->cinfo, COL_RES_DL_DST, "N/A");
+ break;
}
- else {
- if(check_col(fd, COL_RES_DL_DST))
- col_add_str(fd, COL_RES_DL_DST, "DCE");
- if(check_col(fd, COL_RES_DL_SRC))
- col_add_str(fd, COL_RES_DL_SRC, "DTE");
+
+ byte0 = tvb_get_guint8(tvb, 0);
+
+ if (byte0 != 0x01 && byte0 != 0x03) /* invalid LAPB frame */
+ {
+ if (check_col(pinfo->cinfo, COL_INFO))
+ col_set_str(pinfo->cinfo, COL_INFO, "Invalid LAPB frame");
+ if (tree)
+ ti = proto_tree_add_protocol_format(tree, proto_lapb, tvb, 0, -1,
+ "Invalid LAPB frame");
+ return;
}
- if (((fd->pseudo_header.x25.flags & FROM_DCE) && pd[0] == 0x01) ||
- (!(fd->pseudo_header.x25.flags & FROM_DCE) && pd[0] == 0x03))
- is_response = TRUE;
- else
+ switch (pinfo->p2p_dir) {
+
+ case P2P_DIR_SENT:
+ if (byte0 == 0x03)
+ is_response = TRUE;
+ else
+ is_response = FALSE;
+ break;
+
+ case P2P_DIR_RECV:
+ if (byte0 == 0x01)
+ is_response = TRUE;
+ else
+ is_response = FALSE;
+ break;
+
+ default:
+ /*
+ * XXX - should we base this on the source and destination
+ * addresses? The problem is that we can tell one direction
+ * from another with that, but we can't say which is DTE->DCE
+ * and which is DCE->DTE.
+ */
is_response = FALSE;
+ break;
+ }
if (tree) {
- ti = proto_tree_add_item_format(tree, proto_lapb, 0, 2, NULL,
+ ti = proto_tree_add_protocol_format(tree, proto_lapb, tvb, 0, 2,
"LAPB");
- lapb_tree = proto_item_add_subtree(ti, ETT_LAPB);
- proto_tree_add_item_format(lapb_tree, hf_lapb_address, 0, 1, pd[0],
- "Address: 0x%02X", pd[0]);
+ lapb_tree = proto_item_add_subtree(ti, ett_lapb);
+ proto_tree_add_uint_format(lapb_tree, hf_lapb_address, tvb, 0, 1, byte0,
+ "Address: 0x%02X", byte0);
}
else
lapb_tree = NULL;
- dissect_xdlc_control(pd, 1, fd, lapb_tree, hf_lapb_control,
- is_response, FALSE);
+
+ dissect_xdlc_control(tvb, 1, pinfo, lapb_tree, hf_lapb_control,
+ ett_lapb_control, is_response, FALSE, FALSE);
/* not end of frame ==> X.25 */
- if (fd->cap_len > 2) dissect_x25(pd, 2, fd, tree);
+ if (tvb_reported_length(tvb) > 2) {
+ next_tvb = tvb_new_subset(tvb, 2, -1, -1);
+ switch (pinfo->p2p_dir) {
+
+ case P2P_DIR_SENT:
+ case P2P_DIR_RECV:
+ call_dissector(x25_dir_handle, next_tvb, pinfo, tree);
+ break;
+
+ default:
+ call_dissector(x25_handle, next_tvb, pinfo, tree);
+ break;
+ }
+ }
}
void
{
static hf_register_info hf[] = {
{ &hf_lapb_address,
- { "Address Field", "lapb.address", FT_UINT8, NULL} },
+ { "Address Field", "lapb.address", FT_UINT8, BASE_HEX, NULL, 0x0,
+ "Address", HFILL }},
+
{ &hf_lapb_control,
- { "Control Field", "lapb.control", FT_STRING, NULL} },
+ { "Control Field", "lapb.control", FT_UINT8, BASE_HEX, NULL, 0x0,
+ "Control field", HFILL }},
+ };
+ static gint *ett[] = {
+ &ett_lapb,
+ &ett_lapb_control,
};
- proto_lapb = proto_register_protocol ("LAPB", "lapb");
+ proto_lapb = proto_register_protocol("Link Access Procedure Balanced (LAPB)",
+ "LAPB", "lapb");
proto_register_field_array (proto_lapb, hf, array_length(hf));
+ proto_register_subtree_array(ett, array_length(ett));
+
+ register_dissector("lapb", dissect_lapb, proto_lapb);
+}
+
+void
+proto_reg_handoff_lapb(void)
+{
+ dissector_handle_t lapb_handle;
+
+ /*
+ * Get handles for the X.25 dissectors; we don't get an X.25
+ * pseudo-header for LAPB-over-Ethernet, but we do get it
+ * for raw LAPB.
+ */
+ x25_dir_handle = find_dissector("x.25_dir");
+ x25_handle = find_dissector("x.25");
+
+ lapb_handle = find_dissector("lapb");
+ dissector_add("wtap_encap", WTAP_ENCAP_LAPB, lapb_handle);
}
git.samba.org / obnox / wireshark / wip.git / blobdiff