--- /dev/null
+/* packet-sdlc.c
+ * Routines for SDLC frame disassembly
+ *
+ * $Id: packet-sdlc.c,v 1.1 2003/01/03 22:31:24 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdio.h>
+#include <glib.h>
+#include <string.h>
+#include <epan/packet.h>
+#include "xdlc.h"
+
+/*
+ * See
+ *
+ * http://www.protocols.com/pbook/sna.htm
+ */
+
+static int proto_sdlc = -1;
+static int hf_sdlc_address = -1;
+static int hf_sdlc_control = -1;
+
+static gint ett_sdlc = -1;
+static gint ett_sdlc_control = -1;
+
+static dissector_handle_t sna_handle;
+static dissector_handle_t data_handle;
+
+static void
+dissect_sdlc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+ proto_tree *sdlc_tree;
+ proto_item *sdlc_ti;
+ guint8 address;
+ guint16 control;
+ int sdlc_header_len;
+ gboolean is_response;
+ tvbuff_t *next_tvb;
+
+ if (check_col(pinfo->cinfo, COL_PROTOCOL))
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "SDLC");
+ if (check_col(pinfo->cinfo, COL_INFO))
+ col_clear(pinfo->cinfo, COL_INFO);
+
+ address = tvb_get_guint8(tvb, 0);
+ sdlc_header_len = 1; /* address */
+
+ /*
+ * XXX - is there something in the SDLC header that indicates
+ * how to interpret "command vs. response" based on the
+ * direction?
+ */
+ if (pinfo->p2p_dir == P2P_DIR_SENT) {
+ is_response = FALSE;
+ if (check_col(pinfo->cinfo, COL_RES_DL_DST))
+ col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
+ if (check_col(pinfo->cinfo, COL_RES_DL_SRC))
+ col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
+ }
+ else {
+ /* XXX - what if the direction is unknown? */
+ is_response = TRUE;
+ if (check_col(pinfo->cinfo, COL_RES_DL_DST))
+ col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
+ if (check_col(pinfo->cinfo, COL_RES_DL_SRC))
+ col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
+ }
+
+ if (tree) {
+ sdlc_ti = proto_tree_add_item(tree, proto_sdlc, tvb, 0, -1,
+ FALSE);
+ sdlc_tree = proto_item_add_subtree(sdlc_ti, ett_sdlc);
+
+ proto_tree_add_uint(sdlc_tree, hf_sdlc_address, tvb, 0, 1,
+ address);
+ } else {
+ sdlc_ti = NULL;
+ sdlc_tree = NULL;
+ }
+
+ /*
+ * XXX - SDLC has a mod-128 mode as well as a mod-7 mode.
+ * We can infer the mode from an SNRM/SRME frame, but if
+ * we don't see one of them, we may have to have a preference
+ * to control what to use.
+ */
+ control = dissect_xdlc_control(tvb, 1, pinfo, sdlc_tree, hf_sdlc_control,
+ ett_sdlc_control, is_response, FALSE);
+ sdlc_header_len += XDLC_CONTROL_LEN(control, FALSE);
+
+ if (tree)
+ proto_item_set_len(sdlc_ti, sdlc_header_len);
+
+ /*
+ * XXX - is there an FCS at the end, at least in Sniffer
+ * captures? (There doesn't appear to be.)
+ */
+ next_tvb = tvb_new_subset(tvb, sdlc_header_len, -1, -1);
+ if (XDLC_IS_INFORMATION(control)) {
+ /* call the SNA dissector */
+ call_dissector(sna_handle, next_tvb, pinfo, tree);
+ } else
+ call_dissector(data_handle, next_tvb, pinfo, tree);
+}
+
+void
+proto_register_sdlc(void)
+{
+ static hf_register_info hf[] = {
+ { &hf_sdlc_address,
+ { "Address Field", "sdlc.address", FT_UINT8, BASE_HEX,
+ NULL, 0x0, "Address", HFILL }},
+
+ { &hf_sdlc_control,
+ { "Control Field", "sdlc.control", FT_UINT16, BASE_HEX,
+ NULL, 0x0, "Control field", HFILL }},
+ };
+ static gint *ett[] = {
+ &ett_sdlc,
+ &ett_sdlc_control,
+ };
+
+ proto_sdlc = proto_register_protocol(
+ "Synchronous Data Link Control (SDLC)", "SDLC", "sdlc");
+ proto_register_field_array(proto_sdlc, hf, array_length(hf));
+ proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_sdlc(void)
+{
+ dissector_handle_t sdlc_handle;
+
+ /*
+ * Get handle for the SNA dissector.
+ */
+ sna_handle = find_dissector("sna");
+ data_handle = find_dissector("data");
+
+ sdlc_handle = create_dissector_handle(dissect_sdlc, proto_sdlc);
+ dissector_add("wtap_encap", WTAP_ENCAP_SDLC, sdlc_handle);
+}
git.samba.org / obnox / wireshark / wip.git / commitdiff