diff options
Diffstat (limited to 'epan/dissectors/packet-gprs-llc.c')
| -rw-r--r-- | epan/dissectors/packet-gprs-llc.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/epan/dissectors/packet-gprs-llc.c b/epan/dissectors/packet-gprs-llc.c new file mode 100644 index 0000000000..a3837a9221 --- /dev/null +++ b/epan/dissectors/packet-gprs-llc.c @@ -0,0 +1,388 @@ +/* packet-llcgprs.c + * Routines for Logical Link Control GPRS dissection ETSI 4.64 + * Copyright 2000, Josef Korelus <jkor@quick.cz> + * + * $Id$ + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * 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. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <glib.h> + +#ifdef NEED_SNPRINTF_H +# include "snprintf.h" +#endif + +#include <epan/packet.h> +/* +#include "packet-llcgprs.h" +*/ +#define I_FORMAT 1 +#define S_FORMAT 2 +#define UI_FORMAT 3 +#define U_FORMAT 4 +#define I_SACK 5 +#define S_SACK 6 +#define UI_MASK_FMT 0xe000 +#define UI_MASK_SPB 0x1800 +#define UI_MASK_NU 0x07fc +#define UI_MASK_E 0x0002 +#define UI_MASK_PM 0x0001 + +/* Initialize the protocol and registered fields */ +static int proto_llcgprs = -1; +static int hf_llcgprs_pd = -1; +static int hf_llcgprs_cr = -1; +static int hf_llcgprs_sapi = -1; +static int hf_llcgprs_sapib = -1; +static int hf_llcgprs_U_fmt = -1;/* 3 upper bits in controlfield (UI format) */ +static int hf_llcgprs_sp_bits = -1; /*Spare bits in control field*/ +static int hf_llcgprs_NU = -1; /*Transmited unconfirmed sequence number*/ +static int hf_llcgprs_E_bit = -1;/* Encryption mode bit*/ +static int hf_llcgprs_PM_bit = -1; +static int hf_llcgprs_Un = -1; +static int hf_llcgprs_As = -1; +static int hf_llcgprs_ucom = -1; +static int hf_llcgprs_PF = -1; +static int hf_llcgprs_S_fmt = -1; +static int hf_llcgprs_NR = -1; +static int hf_llcgprs_sjsd = -1; +/*static int hf_llcgprs_pd = -1; +*/ +/* Initialize the subtree pointers */ +static gint ett_llcgprs = -1; +static gint ett_llcgprs_adf = -1; +static gint ett_llcgprs_ctrlf = -1; +static gint ett_ui = -1; +static gint ett_llcgprs_sframe = -1; + +static dissector_handle_t data_handle; +static dissector_table_t llcgprs_subdissector_table; +static const value_string sapi_t[] = { + { 0, "Reserved"}, + { 1, "GPRS Mobility Management" }, + { 2, "Tunnelling of messages 2" }, + { 3, "User data 3"}, + { 4, "Reserved" }, + { 5, "User data 5" }, + { 6, "Reserved" }, + { 7, "SMS" }, + { 8, "Tunneling of messages 8" }, + { 9, "User data 9" }, + { 10, "Reserved" }, + { 11, "User data 11" }, + { 12, "Reserved" }, + { 13, "Reserved" }, + { 14, "Reserved" }, + { 15, "Reserved" }, + { 0, NULL }, +}; + +static const value_string sapi_abrv[] = { + { 0, "0"}, + { 1, "LLGMM" }, + { 2, "TOM2" }, + { 3, "LL3"}, + { 4, "4" }, + { 5, "LL5" }, + { 6, "6" }, + { 7, "LLSMS" }, + { 8, "TOM8" }, + { 9, "LL9" }, + { 10, "10" }, + { 11, "LL11" }, + { 12, "12" }, + { 13, "13" }, + { 14, "14" }, + { 15, "15" }, + { 0, NULL }, +}; +static const true_false_string a_bit = { + "To solicit an acknowledgement from the peer LLE. ", + "The peer LLE is not requested to send an acknowledgment." +}; + +static const true_false_string pd_bit = { + "Invalid frame PD=1", + "OK" +}; +static const true_false_string e_bit = { + " encrypted frame", + " non encrypted frame" +}; +static const true_false_string pm_bit = { + "FCS covers the frame header and information fields", + "FCS covers only the frame header and first N202 octets of the information field" +}; +static const true_false_string cr_bit = { + "DownLink/UpLink = Command/Response", + "DownLink/UpLink = Response/Command" +}; +/* bits are swaped comparing with "Table 3" in ETSI document*/ +static const value_string pme[] = { + { 0, "unprotected,non-ciphered information" }, + { 1, "protected, non-ciphered information" }, + { 2, "unprotected,ciphered information"}, + { 3, "protected, ciphered information" }, + { 0, NULL}, +}; + +static const value_string cr_formats_unnumb[]= { + { 0x1, "DM-response" }, + { 0x4, "DISC-command" }, + { 0x6, "UA-response" }, + { 0x7, "SABM" }, + { 0x8, "FRMR" }, + { 0xb, "XID" }, + { 0, NULL }, +}; +static const value_string cr_formats_ipluss[] = { + { 0x0,"RR" }, + { 0x1,"ACK" }, + { 0x2,"RNR" }, + { 0x3,"SACK" }, + { 0, NULL }, +}; +/* Code to actually dissect the packets */ +static void +dissect_llcgprs(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + guint8 addr_fld=0, sapi=0, ctrl_fld_fb=0, frame_format, tmp=0 ; + guint16 offset=0 , epm = 0, nu=0,ctrl_fld_ui_s=0,crc_start=0 ; + proto_item *ti, *addres_field_item, *ctrl_field_item, *ui_ti; + proto_tree *llcgprs_tree=NULL , *ad_f_tree =NULL, *ctrl_f_tree=NULL, *ui_tree=NULL; + tvbuff_t *next_tvb; +/* Make entries in Protocol column and Info column on summary display */ + if (check_col(pinfo->cinfo, COL_PROTOCOL)) + col_set_str(pinfo->cinfo, COL_PROTOCOL, "GPRS-LLC"); + + crc_start = tvb_length(tvb)-3; + addr_fld = tvb_get_guint8(tvb,offset); + offset++; + if (addr_fld > 128 ) { + if (check_col(pinfo->cinfo,COL_INFO)) + col_add_str(pinfo->cinfo,COL_INFO,"Invalid packet - Protocol Discriminator bit is set to 1"); + return; + } + sapi = addr_fld & 0xF; + if (check_col(pinfo->cinfo, COL_INFO)) + col_add_fstr(pinfo->cinfo, COL_INFO, "SAPI: %s", match_strval(sapi,sapi_abrv)); + + + +/* In the interest of speed, if "tree" is NULL, don't do any work not + necessary to generate protocol tree items. */ + if (tree) { + + ti = proto_tree_add_protocol_format(tree, proto_llcgprs, tvb, 0, -1,"MS-SGSN LLC (Mobile Station - Serving GPRS Support Node Logical Link Control) SAPI: %s", match_strval(sapi,sapi_t)); + + llcgprs_tree = proto_item_add_subtree(ti, ett_llcgprs); + +/* add an item to the subtree, see section 1.6 for more information */ + proto_tree_add_text( llcgprs_tree, tvb, crc_start,3, "CRC of LLC layer" ); + addres_field_item = proto_tree_add_uint_format(llcgprs_tree,hf_llcgprs_sapi, + tvb, 0,1, sapi, "Address field SAPI: %s", match_strval(sapi,sapi_abrv)); + ad_f_tree = proto_item_add_subtree(addres_field_item, ett_llcgprs_adf); + proto_tree_add_boolean(ad_f_tree, hf_llcgprs_pd, tvb,0,1, addr_fld ); + proto_tree_add_boolean(ad_f_tree, hf_llcgprs_cr, tvb,0,1, addr_fld ); + proto_tree_add_uint(ad_f_tree, hf_llcgprs_sapib, tvb, 0, 1, addr_fld ); + } + + ctrl_fld_fb = tvb_get_guint8(tvb,offset); + if ( ctrl_fld_fb < 0xc0 ){ + frame_format = ( ctrl_fld_fb < 0x80)? I_FORMAT : S_FORMAT; + } + else { + frame_format = ( ctrl_fld_fb < 0xe0 )? UI_FORMAT : U_FORMAT; + } + switch (frame_format){ + case I_FORMAT: + if (check_col(pinfo->cinfo,COL_INFO)){ + col_append_str(pinfo->cinfo,COL_INFO, ", I"); + } + + break; + case S_FORMAT: + case UI_FORMAT: + nu = ctrl_fld_ui_s = tvb_get_ntohs(tvb, offset); + offset +=2; + epm = ctrl_fld_ui_s & 0x3; + nu = (nu >>2)&0x01FF; + if (frame_format == S_FORMAT){ + if (check_col(pinfo->cinfo, COL_INFO)){ + col_append_str(pinfo->cinfo, COL_INFO, ", S, "); + col_append_str(pinfo->cinfo, COL_INFO, match_strval(epm,cr_formats_ipluss)); + col_append_fstr(pinfo->cinfo, COL_INFO, ", N(R) = %u", nu); + } + if (tree){ + ctrl_field_item = proto_tree_add_text(llcgprs_tree, tvb, offset-2,2,"Supervisory format: %s: N(R) = %u",match_strval(epm,cr_formats_ipluss), nu); + ctrl_f_tree = proto_item_add_subtree( ctrl_field_item, ett_llcgprs_sframe); + proto_tree_add_uint( ctrl_f_tree, hf_llcgprs_S_fmt, tvb, offset-2,2, ctrl_fld_ui_s ); + proto_tree_add_boolean( ctrl_f_tree, hf_llcgprs_As, tvb, offset-2, 2, ctrl_fld_ui_s ); + proto_tree_add_uint(ctrl_f_tree, hf_llcgprs_NR, tvb, offset-2, 2, ctrl_fld_ui_s ); + proto_tree_add_uint(ctrl_f_tree, hf_llcgprs_sjsd, tvb, offset-2, 2, ctrl_fld_ui_s ); + } + }else{ +/*UI format*/ + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_str(pinfo->cinfo, COL_INFO, ", UI, "); + col_append_str(pinfo->cinfo, COL_INFO, match_strval(epm, pme )); + col_append_fstr(pinfo->cinfo,COL_INFO, ", N(U) = %u", nu); + } + if (tree){ + ctrl_field_item = proto_tree_add_text(llcgprs_tree, tvb, offset-2, 2, "Unnumbered Information format - UI, N(U) = %u", nu); + ctrl_f_tree = proto_item_add_subtree(ctrl_field_item, ett_llcgprs_ctrlf); + proto_tree_add_uint( ctrl_f_tree, hf_llcgprs_U_fmt, tvb, offset-2, 2, ctrl_fld_ui_s); + proto_tree_add_uint( ctrl_f_tree, hf_llcgprs_sp_bits, tvb, offset-2,2,ctrl_fld_ui_s); + proto_tree_add_uint( ctrl_f_tree, hf_llcgprs_NU, tvb, offset-2, 2, ctrl_fld_ui_s); + proto_tree_add_boolean( ctrl_f_tree, hf_llcgprs_E_bit, tvb, offset-2,2,ctrl_fld_ui_s); + proto_tree_add_boolean( ctrl_f_tree, hf_llcgprs_PM_bit, tvb, offset-2,2,ctrl_fld_ui_s); + } + + next_tvb = tvb_new_subset(tvb, offset,crc_start-3, -1 ); + if (epm < 2){ + if (!dissector_try_port(llcgprs_subdissector_table,sapi, next_tvb, pinfo, tree)) + call_dissector(data_handle, next_tvb, pinfo, tree); + } + else call_dissector(data_handle, next_tvb, pinfo, tree); + } + break; + case U_FORMAT: + offset +=1; + tmp = 0; + tmp = ctrl_fld_fb & 0xf; + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_str(pinfo->cinfo, COL_INFO, ", U, "); + col_append_str(pinfo->cinfo, COL_INFO, val_to_str(tmp, cr_formats_unnumb,"Unknown/invalid code:%X")); + } + if(tree){ + ui_ti = proto_tree_add_text(llcgprs_tree,tvb,offset-1,crc_start-1,"Unnumbered frame: %s",val_to_str(tmp,cr_formats_unnumb,"Unknown/invalid code:%X")); + ui_tree = proto_item_add_subtree( ui_ti, ett_ui); + proto_tree_add_uint( ui_tree, hf_llcgprs_Un, tvb, offset-1, 1, ctrl_fld_fb); + proto_tree_add_boolean( ui_tree, hf_llcgprs_PF, tvb, offset-1, 1, ctrl_fld_fb); + proto_tree_add_uint( ui_tree, hf_llcgprs_ucom, tvb, offset-1, 1, ctrl_fld_fb); + } + break; +/* case I_SACK: + break; + case S_SACK: + break; +*/ + } +/* proto_tree_add_item(llcgprs_tree, + hf_llcgprs_FIELDABBREV, tvb, offset, len, FALSE) +*/ +/* Continue adding tree items to process the packet here */ + + + +/* If this protocol has a sub-dissector call it here, see section 1.8 */ +} + + +/* Register the protocol with Ethereal */ + +/* this format is require because a script is used to build the C function + that calls all the protocol registration. +*/ + +void +proto_register_llcgprs(void) +{ + +/* Setup list of header fields See Section 1.6.1 for details*/ + static hf_register_info hf[] = { + { &hf_llcgprs_sapi, + { "SAPI", "llcgprs.sapi", FT_UINT8, BASE_DEC, VALS(sapi_abrv), 0x0,"Service Access Point Identifier", HFILL }}, + { &hf_llcgprs_pd, + { "Protocol Discriminator_bit", "llcgprs.pd", FT_BOOLEAN,8, TFS(&pd_bit), 0x80, " Protocol Discriminator bit (should be 0)", HFILL }}, + {&hf_llcgprs_sjsd, + { "Supervisory function bits","llcgprs.s1s2", FT_UINT16, BASE_HEX, VALS(cr_formats_ipluss),0x3, "Supervisory functions bits",HFILL }}, + { &hf_llcgprs_cr, + { "Command/Response bit", "llcgprs.cr", FT_BOOLEAN, 8, TFS(&cr_bit), 0x40, " Command/Response bit", HFILL}}, + { &hf_llcgprs_sapib, + { "SAPI", "llcgprs.sapib", FT_UINT8, BASE_DEC , VALS(sapi_t), 0xf, "Service Access Point Identifier ",HFILL }}, + { &hf_llcgprs_U_fmt, + { "UI format", "llcgprs.ui", FT_UINT16, BASE_HEX, NULL, UI_MASK_FMT, "UI frame format",HFILL}}, + { &hf_llcgprs_Un, + { "U format", "llcgprs.u", FT_UINT8, BASE_DEC, NULL, 0xe0, " U frame format", HFILL}}, + { &hf_llcgprs_sp_bits, + { "Spare bits", "llcgprs.ui_sp_bit", FT_UINT16, BASE_HEX, NULL, UI_MASK_SPB, "Spare bits", HFILL}}, + { &hf_llcgprs_NU, + { "N(U)", "llcgprs.nu", FT_UINT16, BASE_DEC, NULL, UI_MASK_NU, "Transmited unconfirmed sequence number", HFILL}}, + { &hf_llcgprs_E_bit, + { "E bit", "llcgprs.e", FT_BOOLEAN, 16, TFS(&e_bit), UI_MASK_E,"Encryption mode bit",HFILL }}, + { &hf_llcgprs_PM_bit, + { "PM bit", "llcgprs.pm", FT_BOOLEAN, 16, TFS(&pm_bit), UI_MASK_PM, "Protected mode bit",HFILL}}, + { &hf_llcgprs_As, + { "Ackn request bit", "llcgprs.as", FT_BOOLEAN, 16, TFS(&a_bit), 0x2000 ,"Acknowledgement request bit A", HFILL}}, + { &hf_llcgprs_PF, + { "P/F bit", "llcgprs.pf", FT_BOOLEAN, 8, NULL, 0x10,"Poll /Finall bit", HFILL}}, + { &hf_llcgprs_ucom, + { "Command/Response","llcgprs.ucom", FT_UINT8, BASE_HEX, VALS(cr_formats_unnumb),0xf,"Commands and Responses",HFILL }}, + { &hf_llcgprs_NR, + { "Receive sequence number", "llcgprs.nr",FT_UINT16, BASE_DEC, NULL, UI_MASK_NU,"Receive sequence number N(R)",HFILL }}, + {&hf_llcgprs_S_fmt, + { "S format", "llcgprs.s", FT_UINT16, BASE_DEC, NULL, 0xc000,"Supervisory format S", HFILL}} + }; + +/* Setup protocol subtree array */ + static gint *ett[] = { + &ett_llcgprs, + &ett_llcgprs_adf, + &ett_llcgprs_ctrlf, + &ett_ui, + &ett_llcgprs_sframe, + }; + +/* Register the protocol name and description */ + proto_llcgprs = proto_register_protocol("Logical Link Control GPRS", + "GPRS-LLC", "llcgprs"); + llcgprs_subdissector_table = register_dissector_table("llcgprs.sapi","GPRS LLC SAPI", FT_UINT8,BASE_HEX); +/* Required function calls to register the header fields and subtrees used */ + proto_register_field_array(proto_llcgprs, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + register_dissector( "llcgprs", dissect_llcgprs, proto_llcgprs); +} + + +/* If this dissector uses sub-dissector registration add a registration routine. + This format is required because a script is used to find these routines and + create the code that calls these routines. +*/ +void +proto_reg_handoff_llcgprs(void) +{ + dissector_handle_t llcgprs_handle; + + llcgprs_handle = create_dissector_handle(dissect_llcgprs, + proto_llcgprs); +/* dissector_add("PARENT_SUBFIELD", ID_VALUE, llcgprs_handle); +*/ + data_handle = find_dissector("data"); +} + |