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wireshark/epan/xdlc.c
Evan Huus 37600a157b Rename value string (and similar) functions to use a consistent pattern. This 
was done using textual search+replace, not anything syntax-aware, so presumably
it got most comments as well (except where there were typos).

Use a consistent coding style, and make proper use of the WS_DLL_* defines.

Group the functions appropriately in the header.

I ended up getting rid of most of the explanatory comments since many of them
duplicated what was in the value_string.c file (and were out of sync with the
recent updates I made to those in r48633). Presumably most of the comments
should be in the .h file not the .c file, but there's enough churn ahead that
it's not worth fixing yet.

Part of https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8467

svn path=/trunk/; revision=48634
2013-03-29 00:26:23 +00:00

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/* xdlc.c
* Routines for use by various SDLC-derived protocols, such as HDLC
* and its derivatives LAPB, IEEE 802.2 LLC, etc..
*
* $Id$
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/xdlc.h>
#include <epan/emem.h>
const value_string ftype_vals[] = {
{ XDLC_I, "Information frame" },
{ XDLC_S, "Supervisory frame" },
{ XDLC_U, "Unnumbered frame" },
{ 0, NULL }
};
const value_string stype_vals[] = {
{ XDLC_RR>>2, "Receiver ready" },
{ XDLC_RNR>>2, "Receiver not ready" },
{ XDLC_REJ>>2, "Reject" },
{ XDLC_SREJ>>2, "Selective reject" },
{ 0, NULL }
};
static const value_string modifier_short_vals_cmd[] = {
{ XDLC_UI, "UI" },
{ XDLC_UP, "UP" },
{ XDLC_DISC, "DISC" },
{ XDLC_UA, "UA" },
{ XDLC_SNRM, "SNRM" },
{ XDLC_SNRME, "SNRME" },
{ XDLC_TEST, "TEST" },
{ XDLC_SIM, "SIM" },
{ XDLC_FRMR, "FRMR" },
{ XDLC_CFGR, "CFGR" },
{ XDLC_SARM, "SARM" },
{ XDLC_SABM, "SABM" },
{ XDLC_SARME, "SARME" },
{ XDLC_SABME, "SABME" },
{ XDLC_RESET, "RESET" },
{ XDLC_XID, "XID" },
{ XDLC_SNRME, "SNRME" },
{ XDLC_BCN, "BCN" },
{ 0, NULL }
};
const value_string modifier_vals_cmd[] = {
{ XDLC_UI>>2, "Unnumbered Information" },
{ XDLC_UP>>2, "Unnumbered Poll" },
{ XDLC_DISC>>2, "Disconnect" },
{ XDLC_UA>>2, "Unnumbered Acknowledge" },
{ XDLC_SNRM>>2, "Set Normal Response Mode" },
{ XDLC_TEST>>2, "Test" },
{ XDLC_SIM>>2, "Set Initialization Mode" },
{ XDLC_FRMR>>2, "Frame reject" },
{ XDLC_CFGR>>2, "Configure" },
{ XDLC_SARM>>2, "Set Asynchronous Response Mode" },
{ XDLC_SABM>>2, "Set Asynchronous Balanced Mode" },
{ XDLC_SARME>>2, "Set Asynchronous Response Mode Extended" },
{ XDLC_SABME>>2, "Set Asynchronous Balanced Mode Extended" },
{ XDLC_RESET>>2, "Reset" },
{ XDLC_XID>>2, "Exchange identification" },
{ XDLC_SNRME>>2, "Set Normal Response Mode Extended" },
{ XDLC_BCN>>2, "Beacon" },
{ 0, NULL }
};
static const value_string modifier_short_vals_resp[] = {
{ XDLC_UI, "UI" },
{ XDLC_UP, "UP" },
{ XDLC_RD, "RD" },
{ XDLC_UA, "UA" },
{ XDLC_SNRM, "SNRM" },
{ XDLC_TEST, "TEST" },
{ XDLC_RIM, "RIM" },
{ XDLC_FRMR, "FRMR" },
{ XDLC_CFGR, "CFGR" },
{ XDLC_DM, "DM" },
{ XDLC_SABM, "SABM" },
{ XDLC_SARME, "SARME" },
{ XDLC_SABME, "SABME" },
{ XDLC_RESET, "RESET" },
{ XDLC_XID, "XID" },
{ XDLC_SNRME, "SNRME" },
{ XDLC_BCN, "BCN" },
{ 0, NULL }
};
const value_string modifier_vals_resp[] = {
{ XDLC_UI>>2, "Unnumbered Information" },
{ XDLC_UP>>2, "Unnumbered Poll" },
{ XDLC_RD>>2, "Request Disconnect" },
{ XDLC_UA>>2, "Unnumbered Acknowledge" },
{ XDLC_SNRM>>2, "Set Normal Response Mode" },
{ XDLC_TEST>>2, "Test" },
{ XDLC_RIM>>2, "Request Initialization Mode" },
{ XDLC_FRMR>>2, "Frame reject" },
{ XDLC_CFGR>>2, "Configure" },
{ XDLC_DM>>2, "Disconnected mode" },
{ XDLC_SABM>>2, "Set Asynchronous Balanced Mode" },
{ XDLC_SARME>>2, "Set Asynchronous Response Mode Extended" },
{ XDLC_SABME>>2, "Set Asynchronous Balanced Mode Extended" },
{ XDLC_RESET>>2, "Reset" },
{ XDLC_XID>>2, "Exchange identification" },
{ XDLC_SNRME>>2, "Set Normal Response Mode Extended" },
{ XDLC_BCN>>2, "Beacon" },
{ 0, NULL }
};
int
get_xdlc_control(const guchar *pd, int offset, gboolean is_extended)
{
guint16 control;
switch (pd[offset] & 0x03) {
case XDLC_S:
default:
/*
* Supervisory or Information frame.
*/
if (is_extended)
control = pletohs(&pd[offset]);
else
control = pd[offset];
break;
case XDLC_U:
/*
* Unnumbered frame.
*
* XXX - is this two octets, with a P/F bit, in HDLC extended
* operation? It's one octet in LLC, even though the control
* field of I and S frames is a 2-byte extended-operation field
* in LLC. Given that there are no sequence numbers in the
* control field of a U frame, there doesn't appear to be any
* need for it to be 2 bytes in extended operation.
*/
control = pd[offset];
break;
}
return control;
}
/*
* Check whether the control field of the packet looks valid.
*/
gboolean
check_xdlc_control(tvbuff_t *tvb, int offset,
const value_string *u_modifier_short_vals_cmd,
const value_string *u_modifier_short_vals_resp, gboolean is_response,
gboolean is_extended _U_)
{
guint16 control;
if (!tvb_bytes_exist(tvb, offset, 1))
return FALSE; /* not enough data to check */
switch (tvb_get_guint8(tvb, offset) & 0x03) {
case XDLC_S:
/*
* Supervisory frame.
* No fields to check for validity here.
*/
return TRUE;
case XDLC_U:
/*
* Unnumbered frame.
*
* XXX - is this two octets, with a P/F bit, in HDLC extended
* operation? It's one octet in LLC, even though the control
* field of I and S frames is a 2-byte extended-operation field
* in LLC. Given that there are no sequence numbers in the
* control field of a U frame, there doesn't appear to be any
* need for it to be 2 bytes in extended operation.
*/
if (u_modifier_short_vals_cmd == NULL)
u_modifier_short_vals_cmd = modifier_short_vals_cmd;
if (u_modifier_short_vals_resp == NULL)
u_modifier_short_vals_resp = modifier_short_vals_resp;
control = tvb_get_guint8(tvb, offset);
if (is_response) {
if (try_val_to_str(control & XDLC_U_MODIFIER_MASK,
u_modifier_short_vals_resp) == NULL)
return FALSE; /* unknown modifier */
} else {
if (try_val_to_str(control & XDLC_U_MODIFIER_MASK,
u_modifier_short_vals_cmd) == NULL)
return FALSE; /* unknown modifier */
}
return TRUE;
default:
/*
* Information frame.
* No fields to check for validity here.
*/
return TRUE;
}
}
int
dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control,
const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext,
const value_string *u_modifier_short_vals_cmd,
const value_string *u_modifier_short_vals_resp, gboolean is_response,
gboolean is_extended, gboolean append_info)
{
guint16 control;
int control_len;
const xdlc_cf_items *cf_items;
const char *control_format;
guint16 poll_final;
char *info;
proto_tree *tc, *control_tree;
const gchar *frame_type = NULL;
const gchar *modifier;
info=(char *)ep_alloc(80);
switch (tvb_get_guint8(tvb, offset) & 0x03) {
case XDLC_S:
/*
* Supervisory frame.
*/
if (is_extended) {
control = tvb_get_letohs(tvb, offset);
control_len = 2;
cf_items = cf_items_ext;
control_format = "Control field: %s (0x%04X)";
} else {
control = tvb_get_guint8(tvb, offset);
control_len = 1;
cf_items = cf_items_nonext;
control_format = "Control field: %s (0x%02X)";
}
switch (control & XDLC_S_FTYPE_MASK) {
case XDLC_RR:
frame_type = "RR";
break;
case XDLC_RNR:
frame_type = "RNR";
break;
case XDLC_REJ:
frame_type = "REJ";
break;
case XDLC_SREJ:
frame_type = "SREJ";
break;
}
if (is_extended) {
poll_final = (control & XDLC_P_F_EXT);
g_snprintf(info, 80, "S%s, func=%s, N(R)=%u",
(poll_final ?
(is_response ? " F" : " P") :
""),
frame_type,
(control & XDLC_N_R_EXT_MASK) >> XDLC_N_R_EXT_SHIFT);
} else {
poll_final = (control & XDLC_P_F);
g_snprintf(info, 80, "S%s, func=%s, N(R)=%u",
(poll_final ?
(is_response ? " F" : " P") :
""),
frame_type,
(control & XDLC_N_R_MASK) >> XDLC_N_R_SHIFT);
}
if (check_col(pinfo->cinfo, COL_INFO)) {
if (append_info) {
col_append_str(pinfo->cinfo, COL_INFO, ", ");
col_append_str(pinfo->cinfo, COL_INFO, info);
} else
col_add_str(pinfo->cinfo, COL_INFO, info);
}
if (xdlc_tree) {
tc = proto_tree_add_uint_format(xdlc_tree, hf_xdlc_control, tvb,
offset, control_len, control, control_format, info, control);
control_tree = proto_item_add_subtree(tc, ett_xdlc_control);
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_n_r,
tvb, offset, control_len, control);
if (poll_final) {
proto_tree_add_boolean(control_tree,
(is_response ? *cf_items->hf_xdlc_f :
*cf_items->hf_xdlc_p),
tvb, offset, control_len, control);
}
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_s_ftype,
tvb, offset, control_len, control);
/* This will always say it's a supervisory frame */
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_ftype_s_u,
tvb, offset, control_len, control);
}
break;
case XDLC_U:
/*
* Unnumbered frame.
*
* XXX - is this two octets, with a P/F bit, in HDLC extended
* operation? It's one octet in LLC, even though the control
* field of I and S frames is a 2-byte extended-operation field
* in LLC. Given that there are no sequence numbers in the
* control field of a U frame, there doesn't appear to be any
* need for it to be 2 bytes in extended operation.
*/
if (u_modifier_short_vals_cmd == NULL)
u_modifier_short_vals_cmd = modifier_short_vals_cmd;
if (u_modifier_short_vals_resp == NULL)
u_modifier_short_vals_resp = modifier_short_vals_resp;
control = tvb_get_guint8(tvb, offset);
control_len = 1;
cf_items = cf_items_nonext;
control_format = "Control field: %s (0x%02X)";
if (is_response) {
modifier = val_to_str(control & XDLC_U_MODIFIER_MASK,
u_modifier_short_vals_resp, "Unknown");
} else {
modifier = val_to_str(control & XDLC_U_MODIFIER_MASK,
u_modifier_short_vals_cmd, "Unknown");
}
poll_final = (control & XDLC_P_F);
g_snprintf(info, 80, "U%s, func=%s",
(poll_final ?
(is_response ? " F" : " P") :
""),
modifier);
if (check_col(pinfo->cinfo, COL_INFO)) {
if (append_info) {
col_append_str(pinfo->cinfo, COL_INFO, ", ");
col_append_str(pinfo->cinfo, COL_INFO, info);
} else
col_add_str(pinfo->cinfo, COL_INFO, info);
}
if (xdlc_tree) {
tc = proto_tree_add_uint_format(xdlc_tree, hf_xdlc_control, tvb,
offset, control_len, control, control_format, info, control);
control_tree = proto_item_add_subtree(tc, ett_xdlc_control);
if (poll_final) {
proto_tree_add_boolean(control_tree,
(is_response ? *cf_items->hf_xdlc_f:
*cf_items->hf_xdlc_p),
tvb, offset, control_len, control);
}
proto_tree_add_uint(control_tree,
(is_response ? *cf_items->hf_xdlc_u_modifier_resp :
*cf_items->hf_xdlc_u_modifier_cmd),
tvb, offset, control_len, control);
/* This will always say it's an unnumbered frame */
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_ftype_s_u,
tvb, offset, control_len, control);
}
break;
default:
/*
* Information frame.
*/
if (is_extended) {
control = tvb_get_letohs(tvb, offset);
control_len = 2;
cf_items = cf_items_ext;
control_format = "Control field: %s (0x%04X)";
poll_final = (control & XDLC_P_F_EXT);
g_snprintf(info, 80, "I%s, N(R)=%u, N(S)=%u",
((control & XDLC_P_F_EXT) ? " P" : ""),
(control & XDLC_N_R_EXT_MASK) >> XDLC_N_R_EXT_SHIFT,
(control & XDLC_N_S_EXT_MASK) >> XDLC_N_S_EXT_SHIFT);
} else {
control = tvb_get_guint8(tvb, offset);
control_len = 1;
cf_items = cf_items_nonext;
control_format = "Control field: %s (0x%02X)";
poll_final = (control & XDLC_P_F);
g_snprintf(info, 80, "I%s, N(R)=%u, N(S)=%u",
((control & XDLC_P_F) ? " P" : ""),
(control & XDLC_N_R_MASK) >> XDLC_N_R_SHIFT,
(control & XDLC_N_S_MASK) >> XDLC_N_S_SHIFT);
}
if (check_col(pinfo->cinfo, COL_INFO)) {
if (append_info) {
col_append_str(pinfo->cinfo, COL_INFO, ", ");
col_append_str(pinfo->cinfo, COL_INFO, info);
} else
col_add_str(pinfo->cinfo, COL_INFO, info);
}
if (xdlc_tree) {
tc = proto_tree_add_uint_format(xdlc_tree, hf_xdlc_control, tvb,
offset, control_len, control, control_format, info, control);
control_tree = proto_item_add_subtree(tc, ett_xdlc_control);
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_n_r,
tvb, offset, control_len, control);
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_n_s,
tvb, offset, control_len, control);
if (poll_final) {
proto_tree_add_boolean(control_tree, *cf_items->hf_xdlc_p,
tvb, offset, control_len, control);
}
/* This will always say it's an information frame */
proto_tree_add_uint(control_tree, *cf_items->hf_xdlc_ftype_i,
tvb, offset, control_len, control);
}
break;
}
return control;
}
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