/* packet-ipars.c * Routines for IPARS/ALC (International Passenger Airline Reservation System/Airline Link Control) WAN protocol dissection * Copyright 2007, Fulko Hew, SITA INC Canada, Inc. * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* NOTE: This should be rewritten to be more in line with how packet-uts.c is * written so that there are filterable fields available for IPARS too. */ #include "config.h" #include #include void proto_register_ipars(void); static int proto_ipars; static int ett_ipars; #define S1 (0x00) #define S2 (0x20) #define GA (0x03) #define EOMpb (0x10) #define EOMc (0x11) #define EOMu (0x12) #define EOMi (0x13) #define MAX_EOM_MSG_SIZE (24) /* max size of an EOMx indicator string */ static int dissect_ipars(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { int bytes; uint8_t ia = 0, ta = 0, cmd = 0, la = 0; tvbuff_t *next_tvb; int offset = 0; char *eom_msg; uint8_t ipars_eomtype; eom_msg = (char *)wmem_alloc(pinfo->pool, MAX_EOM_MSG_SIZE); eom_msg[0] = 0; col_clear(pinfo->cinfo, COL_INFO); col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPARS"); if (tvb_captured_length_remaining(tvb, 0) >= 2 ) { ia = tvb_get_uint8(tvb, 0) & 0x3f; ta = tvb_get_uint8(tvb, 1) & 0x3f; if (ia == S1 && ta == S2) { /* if the first two bytes are S1/S2 skip over them */ offset = 2; } } if (tvb_captured_length_remaining(tvb, offset) >= 1) ia = tvb_get_uint8(tvb, offset + 0); if (tvb_captured_length_remaining(tvb, offset) >= 2) ta = tvb_get_uint8(tvb, offset + 1); if (ia == 0x83 || ia == 0x43 || ia == GA) { /* if it's an FPGA or 'corresponsdance code' 'go ahead'... */ if (tvb_captured_length_remaining(tvb, offset) > 2) { /* if the msg is long, it must have been a 'poll' */ col_add_fstr(pinfo->cinfo, COL_INFO, "Poll IA: %2.2X", ta); } else { /* if it's short, then it was a 'no traffic' response */ if (tvb_captured_length_remaining(tvb, offset) >= 2 ) { col_add_fstr(pinfo->cinfo, COL_INFO, "GoAhead NextIA (0x%2.2X)", ta); } else { col_set_str(pinfo->cinfo, COL_INFO, "GoAhead NextIA"); } } } else { /* if it's not a 'go ahead'... it must be some kind of data message */ ia &= 0x3f; ta &= 0x3f; if (ta == 0x20) { col_add_fstr(pinfo->cinfo, COL_INFO, "Reset IA: %2.2X", ia); /* the TA character was the 'reset' command */ } if (tvb_captured_length_remaining(tvb, offset) >= 3) cmd = tvb_get_uint8(tvb, offset + 2) & 0x3f; /* get the first two bytes of the data message */ if (tvb_captured_length_remaining(tvb, offset) >= 4) la = tvb_get_uint8(tvb, offset + 3) & 0x3f; if (cmd == 0x1f && la == 0x38) { col_add_fstr(pinfo->cinfo, COL_INFO, "Please Resend - IA: %2.2X TA: %2.2X", ia, ta); /* light the resend indicator */ } else if (cmd == 0x2a && la == 0x05) { col_add_fstr(pinfo->cinfo, COL_INFO, "Unsolicited Msg Indicator - IA: %2.2X TA: %2.2X", ia, ta); /* light the unsolicited msg indicator */ } else { col_add_fstr(pinfo->cinfo, COL_INFO, "Data Msg - IA: %2.2X TA: %2.2X", ia, ta); /* it was a data message (display or printer */ } } bytes = tvb_captured_length_remaining(tvb, 0); if (bytes > 0) { proto_tree *ipars_tree; proto_item *ti; ia = tvb_get_uint8(tvb, 0) & 0x3f; ti = proto_tree_add_protocol_format(tree, proto_ipars, tvb, 0, -1, "Ipars"); ipars_tree = proto_item_add_subtree(ti, ett_ipars); if (ia == 0x03) { proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 0, 1, "GoAhead Next IA"); col_set_str(pinfo->cinfo, COL_INFO, "GoAhead"); return tvb_captured_length(tvb); } else if (ia != S1) { proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 0, bytes, "Unknown format - Data (%d byte%s)", bytes, plurality(bytes, "", "s")); return tvb_captured_length(tvb); } proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 0, 1, "S1"); ia = tvb_get_uint8(tvb, 1) & 0x3f; if (ia != S2) { proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 0, bytes, "Unknown format - Data (%d byte%s)", bytes, plurality(bytes, "", "s")); return tvb_captured_length(tvb); } proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 1, 1, "S2"); ia = tvb_get_uint8(tvb, 2) & 0x3f; if (ia == GA) { ia = tvb_get_uint8(tvb, 3) & 0x3f; proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 2, 2, "GoAhead IA: %2.2X", ia); ipars_eomtype = tvb_get_uint8(tvb, 4) & 0x3f; switch (ipars_eomtype) { case EOMc: snprintf(eom_msg, MAX_EOM_MSG_SIZE, "EOMc"); break; case EOMi: snprintf(eom_msg, MAX_EOM_MSG_SIZE, "EOMi"); break; case EOMu: snprintf(eom_msg, MAX_EOM_MSG_SIZE, "EOMu"); break; case EOMpb: snprintf(eom_msg, MAX_EOM_MSG_SIZE, "EOMpb"); break; default: snprintf(eom_msg, MAX_EOM_MSG_SIZE, "Unknown EOM type (0x%2.2X)", ia); break; } proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 4, 1, "%s", eom_msg); proto_tree_add_protocol_format(ipars_tree, proto_ipars, tvb, 5, 1, "Good BCC"); } else { next_tvb = tvb_new_subset_remaining(tvb, 3); proto_tree_add_protocol_format(ipars_tree, proto_ipars, next_tvb, 0, bytes, "Data (%d byte%s)", bytes, plurality(bytes, "", "s")); return tvb_captured_length(tvb); } } return tvb_captured_length(tvb); } void proto_register_ipars(void) { static int *ett[] = { &ett_ipars, }; proto_ipars = proto_register_protocol("International Passenger Airline Reservation System", "IPARS", "ipars"); proto_register_subtree_array(ett, array_length(ett)); register_dissector("ipars", dissect_ipars, proto_ipars); } /* * 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: */