diff options
Diffstat (limited to 'epan/dissectors/asn1/atn-cpdlc/packet-atn-cpdlc-template.c')
| -rw-r--r-- | epan/dissectors/asn1/atn-cpdlc/packet-atn-cpdlc-template.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/epan/dissectors/asn1/atn-cpdlc/packet-atn-cpdlc-template.c b/epan/dissectors/asn1/atn-cpdlc/packet-atn-cpdlc-template.c new file mode 100644 index 0000000000..500dd3d511 --- /dev/null +++ b/epan/dissectors/asn1/atn-cpdlc/packet-atn-cpdlc-template.c @@ -0,0 +1,367 @@ +/* packet-atn-cpdlc-template.c + * By Mathias Guettler <guettler@web.de> + * Copyright 2013 + * + * Routines for ATN Cpdlcc protocol packet disassembly + + * details see: + * http://en.wikipedia.org/wiki/CPDLC + * http://members.optusnet.com.au/~cjr/introduction.htm + + * standards: + * http://legacy.icao.int/anb/panels/acp/repository.cfm + + * note: + * We are dealing with ATN/CPDLC aka ICAO Doc 9705 Ed2 here + * (CPDLC may also be transmitted via ACARS/AOA aka "FANS-1/A "). + + * + * 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. + */ + +/* + developper comments: + Which CPDLC messages are supported ? + Protected Mode CPDLC (AeQualifier 22) and Plain Old CPDLC (AeQualifier 2) + The dissector has been tested with ICAO doc9705 Edition2 compliant traffic. +*/ + +#include "config.h" + +#include <epan/packet.h> +#include <epan/exceptions.h> +#include <epan/conversation.h> +#include "packet-ber.h" +#include "packet-per.h" +#include "packet-atn-ulcs.h" + +#define ATN_CPDLC_PROTO "ICAO Doc9705 CPDLC" + +void proto_register_atn_cpdlc(void); +void proto_reg_handoff_atn_cpdlc(void); + +static const char *object_identifier_id; + +/* IA5 charset (7-bit) for PER IA5 decoding */ +static const gchar ia5alpha[] = { + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, \ + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, \ + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, \ + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, \ + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, \ + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, \ + 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, \ + 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, \ + 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, '\0' +}; + +/* forward declarations */ +static int dissect_GroundPDUs_PDU( + tvbuff_t *tvb _U_, + packet_info *pinfo _U_, + proto_tree *tree _U_, + void *data _U_); +static int dissect_AircraftPDUs_PDU( + tvbuff_t *tvb _U_, + packet_info *pinfo _U_, + proto_tree *tree _U_, + void *data _U_); +static int dissect_ProtectedGroundPDUs_PDU( + tvbuff_t *tvb _U_, + packet_info *pinfo _U_, + proto_tree *tree _U_, + void *data _U_); +static int dissect_ProtectedAircraftPDUs_PDU( + tvbuff_t *tvb _U_, + packet_info *pinfo _U_, + proto_tree *tree _U_, + void *data _U_); + +#include "packet-atn-cpdlc-hf.c" + +#include "packet-atn-cpdlc-ett.c" +static gint ett_atn_cpdlc = -1; + +#include "packet-atn-cpdlc-fn.c" + +/* Wireshark ID of CPDLC protocol */ +static int proto_atn_cpdlc = -1; + + +static int +dissect_atn_cpdlc( + tvbuff_t *tvb, + packet_info *pinfo, + proto_tree *tree, + void *data _U_) +{ + /* note: */ + /* there are two co-existing applications of CPDLC: */ + /* "plain old" (ae-qualifier 2) and */ + /* "protected mode" (ae-qualifier 22) CPDLC. */ + /* "protected mode" was introduced to cope with a */ + /* safety issue in which a message would sent to the wrong aircraft. */ + + /* note:*/ + /* The protection is an additional checksum and covers the message content, */ + /* the 24-bit address of the aircraft, the current flight id and */ + /* the current ground facility so that an aircraft would be able to reject */ + /* messages which are unexpected (i.e. messages to another flight or */ + /* messages from the wrong center). */ + + /*note:*/ + /* although "plain old" CPDLC is more or less deprecated */ + /* many aircraft cannot perform */ + /* "protected mode" for this largely depends on */ + /* upgraded avionics packages */ + + /*note:*/ + /* The use of CPDLC is *optional* as the pilot */ + /* may always use a voice radio channel to talk to the controller.*/ + + proto_tree *atn_cpdlc_tree = NULL; + atn_conversation_t *atn_cv = NULL; + + /* note: */ + /* we need the ae qualifier stored within the conversation */ + /* to decode "plain old cpdlc" or */ + /* "protected mode cpdlc correctly " */ + + /* DT: dstref present, srcref is always zero */ + if((pinfo->clnp_dstref) && (!pinfo->clnp_srcref)){ + atn_cv = find_atn_conversation( + &pinfo->dst, + pinfo->clnp_dstref, + &pinfo->src ); + } + /* CR: srcref present, dstref is always zero */ + if((!pinfo->clnp_dstref) && (pinfo->clnp_srcref)){ + atn_cv = find_atn_conversation( + &pinfo->src, + pinfo->clnp_srcref, + &pinfo->dst ); + } + /* CC: srcref and dstref present, always use src/srcref & dst */ + if((pinfo->clnp_dstref) && (pinfo->clnp_srcref)){ + atn_cv = find_atn_conversation( + &pinfo->src, + pinfo->clnp_srcref, + &pinfo->dst ); + } + + if(!atn_cv){ /* atn conversation not found */ + return 0; } + + atn_cpdlc_tree = proto_tree_add_subtree( + tree, tvb, 0, -1, ett_atn_cpdlc, NULL, + ATN_CPDLC_PROTO ); + + switch(atn_cv->ae_qualifier){ + case pmcpdlc: + if( check_heur_msg_type(pinfo) == um ) { + /* uplink PDU's = Ground PDU's */ + dissect_ProtectedGroundPDUs_PDU( + tvb, + pinfo, + atn_cpdlc_tree, NULL); + }else { /* downlink PDU's = Aircraft PDU's */ + dissect_ProtectedAircraftPDUs_PDU( + tvb, + pinfo, + atn_cpdlc_tree, NULL); + } + break; + case cpdlc: + if( check_heur_msg_type(pinfo) == um ) { + /* uplink PDU's = Ground PDU's */ + dissect_GroundPDUs_PDU( + tvb, + pinfo, + atn_cpdlc_tree, NULL); + }else { /* downlink PDU's = Aircraft PDU's */ + dissect_AircraftPDUs_PDU( + tvb, + pinfo, + atn_cpdlc_tree, NULL); + } + break; + default: + break; + } + return tvb_reported_length_remaining(tvb, 0); +} + +static gboolean +dissect_atn_cpdlc_heur( + tvbuff_t *tvb, + packet_info *pinfo, + proto_tree *tree, + void *data _U_) +{ + atn_conversation_t *volatile atn_cv = NULL; + volatile gboolean is_atn_cpdlc = FALSE; + volatile gboolean is_pm = FALSE; + int type; + + type = check_heur_msg_type(pinfo); + + switch(type){ + case um: + TRY { + dissect_ProtectedGroundPDUs_PDU(tvb, pinfo, NULL, NULL); + is_atn_cpdlc = TRUE; + is_pm = TRUE;} + CATCH_ALL{ + is_atn_cpdlc = FALSE; + is_pm = FALSE;} + ENDTRY; + if (is_atn_cpdlc) { + break; + } + TRY { + dissect_GroundPDUs_PDU(tvb, pinfo, NULL, NULL); + is_pm = FALSE; + is_atn_cpdlc = TRUE;} + CATCH_ALL{ + is_atn_cpdlc = FALSE; + is_pm = FALSE;} + ENDTRY; + break; + case dm: + TRY { + dissect_ProtectedAircraftPDUs_PDU(tvb, pinfo, NULL, NULL); + is_atn_cpdlc = TRUE; + is_pm = TRUE;} + CATCH_ALL { + is_atn_cpdlc = FALSE; + is_pm = FALSE; } + ENDTRY; + if (is_atn_cpdlc) { + break; + } + TRY{ + dissect_AircraftPDUs_PDU(tvb, pinfo, NULL, NULL); + is_atn_cpdlc = TRUE; + is_pm = FALSE;} + CATCH_ALL{ + is_atn_cpdlc = FALSE; + is_pm = FALSE;} + ENDTRY; + break; + default: + break; + } + + if(is_atn_cpdlc){ + /* note: */ + /* all subsequent PDU's belonging to this conversation */ + /* are considered CPDLC */ + /* if the first CPDLC PDU has been decoded successfully */ + /* (This is done in "atn-ulcs" by using "call_dissector_with_data()") */ + + /* DT: dstref present, srcref is always zero */ + if((pinfo->clnp_dstref) && (!pinfo->clnp_srcref)){ + atn_cv = find_atn_conversation(&pinfo->dst, + pinfo->clnp_dstref, + &pinfo->src ); + } + /* CR: srcref present, dstref is always zero */ + if((!pinfo->clnp_dstref) && (pinfo->clnp_srcref)){ + atn_cv = find_atn_conversation(&pinfo->src, + pinfo->clnp_srcref, + &pinfo->dst ); + } + /* CC: srcref and dstref present, always use src/srcref & dst */ + if((pinfo->clnp_dstref) && (pinfo->clnp_srcref)){ + atn_cv = find_atn_conversation(&pinfo->src, + pinfo->clnp_srcref, + &pinfo->dst ); + } + + if(atn_cv){ /* atn conversation found */ + if(is_pm == TRUE) { + atn_cv->ae_qualifier = pmcpdlc; } + else { + atn_cv->ae_qualifier = cpdlc; } + dissect_atn_cpdlc(tvb, pinfo, tree, NULL); + } + }else { /* there should *always* be an atn conversation */ + is_atn_cpdlc = FALSE; + } + + return is_atn_cpdlc; +} + + + +void proto_register_atn_cpdlc (void) +{ + static hf_register_info hf_atn_cpdlc[] = { + #include "packet-atn-cpdlc-hfarr.c" + }; + + static gint *ett[] = { + #include "packet-atn-cpdlc-ettarr.c" + &ett_atn_cpdlc + }; + + /* register CPDLC */ + proto_atn_cpdlc = proto_register_protocol( + ATN_CPDLC_PROTO , + "ATN-CPDLC", + "atn-cpdlc"); + + proto_register_field_array( + proto_atn_cpdlc, + hf_atn_cpdlc, + array_length(hf_atn_cpdlc)); + + proto_register_subtree_array( + ett, + array_length(ett)); + + register_dissector( + "atn-cpdlc", + dissect_atn_cpdlc, + proto_atn_cpdlc); +} + +void proto_reg_handoff_atn_cpdlc(void) +{ + /* add session dissector to atn dissector list dissector list*/ + heur_dissector_add( + "atn-ulcs", + dissect_atn_cpdlc_heur, + "ATN-CPDLC over ATN-ULCS", + "atn-cpdlc-ulcs", + proto_atn_cpdlc, HEURISTIC_ENABLE); +} + +/* + * Editor modelines - http://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: + */ |