wireshark/epan/dissectors/packet-lmi.c

245 lines
7.2 KiB
C

/* packet-lmi.c
* Routines for Frame Relay Local Management Interface (LMI) disassembly
* Copyright 2001, Jeffrey C. Foster <jfoste@woodward.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* ToDo:
*
* References:
*
* http://www.techfest.com/networking/wan/frrel.htm
* https://www.broadband-forum.org/technical/download/FRF.1.2/frf1_2.pdf
* http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/frame.htm#xtocid18
* http://www.net.aapt.com.au/techref/lmimess.htm
* http://www.raleigh.ibm.com:80/cgi-bin/bookmgr/BOOKS/EZ305800/1.2.4.4
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/nlpid.h>
void proto_register_lmi(void);
void proto_reg_handoff_lmi(void);
static int proto_lmi = -1;
static int hf_lmi_call_ref = -1;
static int hf_lmi_msg_type = -1;
static int hf_lmi_inf_ele = -1;
static int hf_lmi_inf_len = -1;
static int hf_lmi_rcd_type = -1;
static int hf_lmi_send_seq = -1;
static int hf_lmi_recv_seq = -1;
static int hf_lmi_dlci_high = -1;
static int hf_lmi_dlci_low = -1;
static int hf_lmi_new = -1;
static int hf_lmi_act = -1;
static gint ett_lmi = -1;
static gint ett_lmi_ele = -1;
#ifdef _OLD_
/*
* Bits in the address field.
*/
#define LMI_CMD 0xf000 /* LMI Command */
#define LMI_SEQ 0x0fff /* LMI Sequence number */
#endif
static const value_string msg_type_str[] = {
{0x75, "Status Enquiry"},
{0x7D, "Status"},
{ 0, NULL }
};
static const value_string element_type_str[] = {
/*** These are the ANSI values ***/
{0x01, "Report"},
{0x03, "Keep Alive"},
{0x07, "PVC Status"},
/*** These are the ITU values ***/
{0x51, "Report"},
{0x53, "Keep Alive"},
{0x07, "PVC Status"},
{0, NULL }
};
static const value_string record_type_str[] = {
{0x00, "Full Status"},
{0x01, "Link Integrity Verification Only"},
{0x02, "Single PVC"},
{0, NULL }
};
static const value_string pvc_status_new_str[] = {
{0x00, "PVC already present"},
{0x01, "PVC is new"},
{0, NULL }
};
static const value_string pvc_status_act_str[] = {
{0x00, "PVC is Inactive"},
{0x01, "PVC is Active"},
{0, NULL }
};
static void
dissect_lmi_report_type(tvbuff_t *tvb, int offset, proto_tree *tree)
{
proto_tree_add_item(tree, hf_lmi_rcd_type, tvb, offset, 1, ENC_NA);
}
static void
dissect_lmi_link_int(tvbuff_t *tvb, int offset, proto_tree *tree)
{
proto_tree_add_item(tree, hf_lmi_send_seq, tvb, offset, 1, ENC_NA);
++offset;
proto_tree_add_item(tree, hf_lmi_recv_seq, tvb, offset, 1, ENC_NA);
}
static void
dissect_lmi_pvc_status(tvbuff_t *tvb, int offset, proto_tree *tree)
{
proto_tree_add_item(tree, hf_lmi_dlci_high, tvb, offset, 1, ENC_NA);
++offset;
proto_tree_add_item(tree, hf_lmi_dlci_low, tvb, offset, 1, ENC_NA);
++offset;
proto_tree_add_item(tree, hf_lmi_new, tvb, offset, 1, ENC_NA);
proto_tree_add_item(tree, hf_lmi_act, tvb, offset, 1, ENC_NA);
}
static int
dissect_lmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *lmi_tree, *lmi_subtree;
proto_item *ti;
int offset = 2, len;
guint8 msg_type;
guint8 ele_id;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "LMI");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_lmi, tvb, 0, 3, ENC_NA);
lmi_tree = proto_item_add_subtree(ti, ett_lmi_ele);
proto_tree_add_item(lmi_tree, hf_lmi_call_ref, tvb, 0, 1, ENC_BIG_ENDIAN);
msg_type = tvb_get_guint8( tvb, 1);
col_add_str(pinfo->cinfo, COL_INFO,
val_to_str(msg_type, msg_type_str, "Unknown message type (0x%02x)"));
proto_tree_add_uint(lmi_tree, hf_lmi_msg_type, tvb, 1, 1, msg_type);
/* Display the LMI elements */
while (tvb_reported_length_remaining(tvb, offset) > 0) {
ele_id = tvb_get_guint8( tvb, offset);
len = tvb_get_guint8( tvb, offset + 1);
lmi_subtree = proto_tree_add_subtree_format(lmi_tree, tvb, offset, len + 2,
ett_lmi_ele, NULL, "Information Element: %s",
val_to_str(ele_id, element_type_str, "Unknown (%u)"));
proto_tree_add_uint(lmi_subtree, hf_lmi_inf_ele, tvb, offset, 1,
ele_id);
++offset;
proto_tree_add_uint(lmi_subtree, hf_lmi_inf_len, tvb, offset, 1, len);
++offset;
if (( ele_id == 1) || (ele_id == 51))
dissect_lmi_report_type( tvb, offset, lmi_subtree);
else if (( ele_id == 3) || (ele_id == 53))
dissect_lmi_link_int( tvb, offset, lmi_subtree);
else if (( ele_id == 7) || (ele_id == 57))
dissect_lmi_pvc_status( tvb, offset, lmi_subtree);
offset += len;
}
return tvb_captured_length(tvb);
}
void
proto_register_lmi(void)
{
static hf_register_info hf[] = {
{ &hf_lmi_call_ref,
{ "Call reference", "lmi.cmd", FT_UINT8, BASE_HEX, NULL, 0,
NULL, HFILL }},
{ &hf_lmi_msg_type,
{ "Message Type", "lmi.msg_type", FT_UINT8, BASE_HEX, VALS(msg_type_str), 0,
NULL, HFILL }},
{ &hf_lmi_inf_ele,
{ "Type", "lmi.inf_ele_type", FT_UINT8, BASE_DEC, VALS(element_type_str), 0,
"Information Element Type", HFILL }},
{ &hf_lmi_inf_len,
{ "Length", "lmi.inf_ele_len", FT_UINT8, BASE_DEC, NULL, 0,
"Information Element Length", HFILL }},
{ &hf_lmi_rcd_type,
{ "Record Type", "lmi.ele_rcd_type", FT_UINT8, BASE_DEC, VALS(record_type_str), 0,
NULL, HFILL }},
{ &hf_lmi_send_seq,
{ "Send Seq", "lmi.send_seq", FT_UINT8, BASE_DEC, NULL, 0,
"Send Sequence", HFILL }},
{ &hf_lmi_recv_seq,
{ "Recv Seq", "lmi.recv_seq", FT_UINT8, BASE_DEC, NULL, 0,
"Receive Sequence", HFILL }},
{ &hf_lmi_dlci_high,
{ "DLCI High", "lmi.dlci_hi", FT_UINT8, BASE_DEC, NULL, 0x3f,
"DLCI High bits", HFILL }},
{ &hf_lmi_dlci_low,
{ "DLCI Low", "lmi.dlci_low", FT_UINT8, BASE_DEC, NULL, 0x78,
"DLCI Low bits", HFILL }},
{ &hf_lmi_new,
{ "DLCI New", "lmi.dlci_new", FT_UINT8, BASE_DEC, VALS(pvc_status_new_str), 0x08,
"DLCI New Flag", HFILL }},
{ &hf_lmi_act,
{ "DLCI Active","lmi.dlci_act", FT_UINT8, BASE_DEC, VALS(pvc_status_act_str), 0x02,
"DLCI Active Flag", HFILL }},
};
static gint *ett[] = {
&ett_lmi,
&ett_lmi_ele,
};
proto_lmi = proto_register_protocol ("Local Management Interface", "LMI", "lmi");
proto_register_field_array (proto_lmi, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_lmi(void)
{
dissector_handle_t lmi_handle;
lmi_handle = create_dissector_handle(dissect_lmi, proto_lmi);
dissector_add_uint("fr.nlpid", NLPID_LMI, lmi_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/