/* packet-flip.c * Routines for FLIP packet dissection * * Copyright 2009, Juha Siltanen * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* * FLIP (Flow Layer Internal Protocol) is a proprietary protocol * developed by Nokia Solutions and Networks (previous was 'Nokia Siemens Networks'). */ /* * Version information * * Version 0.0.1, November 23rd, 2009. * * Support for the basic and checksum headers. * * Version 0.0.2, August 26th, 2010. * * Support for payload dissecting. * * Version 0.0.3, September 14th, 2010. * * Bugfix: sorting by protocol didn't always fill in the protocol column. */ #include "config.h" #include #include #include #include #include #include void proto_register_flip(void); void proto_reg_handoff_flip(void); static dissector_handle_t flip_handle; static int proto_flip; /* BASIC */ static int hf_flip_basic_e; static int hf_flip_basic_reserved; static int hf_flip_basic_flowid; static int hf_flip_basic_seqnum; static int hf_flip_basic_len; /* CHECKSUM */ static int hf_flip_chksum_etype; static int hf_flip_chksum_spare; static int hf_flip_chksum_e; static int hf_flip_chksum_chksum; #define FLIP_BASIC (0) #define FLIP_CHKSUM (1) #define FLIP_BASIC_HDR_LEN (8) #define FLIP_CHKSUM_HDR_LEN (4) #define FLIP_EXTENSION_HDR_MIN_LEN (4) static const value_string flip_etype[] = { { FLIP_CHKSUM, "Checksum" }, { 0, NULL } }; static dissector_table_t subdissector_table; static gint ett_flip; static gint ett_flip_basic; static gint ett_flip_chksum; static gint ett_flip_payload; static void flip_prompt(packet_info *pinfo _U_, gchar* result) { snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Decode FLIP payload protocol as"); } /* Dissect the checksum extension header. */ static int dissect_flip_chksum_hdr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint16 computed_chksum, gboolean *ext_hdr_follows_ptr) { proto_tree *chksum_hdr_tree; guint32 dw; guint8 chksum_hdr_etype; guint8 chksum_hdr_ext; guint16 chksum_hdr_chksum; gint bytes_dissected; gint offset; chksum_hdr_tree = NULL; bytes_dissected = 0; offset = 0; dw = tvb_get_ntohl(tvb, offset); chksum_hdr_etype = (guint8) ((dw & 0xFF000000) >> 24); chksum_hdr_ext = (guint8) ((dw & 0x00010000) >> 16); chksum_hdr_chksum = (guint16) (dw & 0x0000FFFF); /* The actually shouldn't be any headers after checksum. */ if (chksum_hdr_ext == 1) { *ext_hdr_follows_ptr = TRUE; } else { *ext_hdr_follows_ptr = FALSE; } if (tree) { chksum_hdr_tree = proto_tree_add_subtree(tree, tvb, offset + 0, 4, ett_flip_chksum, NULL, "Checksum Header"); /* ETYPE: 8 bits */ proto_tree_add_uint_format_value(chksum_hdr_tree, hf_flip_chksum_etype, tvb, offset + 0, 1, dw, "%s", val_to_str_const(chksum_hdr_etype, flip_etype, "Unknown")); /* SPARE: 7 bits */ proto_tree_add_item(chksum_hdr_tree, hf_flip_chksum_spare, tvb, offset, 4, ENC_BIG_ENDIAN); /* EXT HDR: 1 bit */ proto_tree_add_item(chksum_hdr_tree, hf_flip_chksum_e, tvb, offset, 4, ENC_BIG_ENDIAN); /* CHKSUM: 16 bits. */ proto_tree_add_uint_format_value( chksum_hdr_tree, hf_flip_chksum_chksum, tvb, offset + 2, 2, chksum_hdr_chksum, "0x%04x [%s] (computed 0x%04x)", chksum_hdr_chksum, ((chksum_hdr_chksum == computed_chksum) ? "Correct" : "Incorrect"), computed_chksum); } /* Show faulty checksums. */ if (computed_chksum != chksum_hdr_chksum) { col_add_fstr(pinfo->cinfo, COL_INFO, "Checksum 0x%04x [%s] (computed 0x%04x)", chksum_hdr_chksum, "Incorrect", computed_chksum); } bytes_dissected += FLIP_CHKSUM_HDR_LEN; return bytes_dissected; } /* dissect_flip_chksum_hdr() */ /* Protocol dissection */ static int dissect_flip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { proto_item *ti = NULL; proto_tree *flip_tree = NULL; proto_tree *basic_hdr_tree = NULL; tvbuff_t *flip_tvb; guint32 dw1; /* Basic header fields. */ guint8 basic_hdr_ext; guint32 basic_hdr_flow_id; guint16 basic_hdr_len; gboolean ext_hdr = FALSE; gint bytes_dissected = 0; gint payload_len; gint frame_len; gint flip_len; gint offset = 0; /* Error handling for basic header. */ gboolean is_faulty_frame = FALSE; /* Show this protocol as FLIP. */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "FLIP"); /* * The frame can be faulty in several ways: * - too short (even for the basic header) * - length inconsistent (header and frame info different) * - checksum doesn't check out * - extension header is indicated, but the frame is too short for it * - unknown extension header type */ /* Check that there's enough data at least for the basic header. */ frame_len = tvb_captured_length(tvb); if (frame_len < FLIP_BASIC_HDR_LEN) { return 0; } bytes_dissected += FLIP_BASIC_HDR_LEN; /* Process the first 32 bits of the basic header. */ dw1 = tvb_get_ntohl(tvb, offset + 0); basic_hdr_ext = ((dw1 & 0x80000000) >> 31); basic_hdr_flow_id = (dw1 & 0x0FFFFFFF); /* Process the second 32 bits of the basic header. */ basic_hdr_len = (guint16) (tvb_get_ntohl(tvb, offset + 4) & 0x0000FFFF); /* Does the basic header indicate that an extension is next? */ if (basic_hdr_ext == 1) { ext_hdr = TRUE; } flip_len = basic_hdr_len; /* * Check the length value. */ if ((flip_len < FLIP_BASIC_HDR_LEN) || (flip_len > frame_len)) { /* Faulty frame. Show the basic header anyway for debugging. */ is_faulty_frame = TRUE; } /* Fill in the info column. */ col_add_fstr(pinfo->cinfo, COL_INFO, "FlowID %s", val_to_str(basic_hdr_flow_id, NULL, "0x%08x")); flip_tvb = tvb_new_subset_length(tvb, 0, frame_len); /* We are asked for details. */ if (tree) { ti = proto_tree_add_protocol_format( tree, proto_flip, flip_tvb, 0, flip_len, "NSN FLIP, FlowID %s", val_to_str(basic_hdr_flow_id, NULL, "0x%08x")); flip_tree = proto_item_add_subtree(ti, ett_flip); /* basic header */ basic_hdr_tree = proto_tree_add_subtree(flip_tree, flip_tvb, offset, 8, ett_flip_basic, NULL, "Basic Header"); /* Extension header follows? 1 bit. */ proto_tree_add_item(basic_hdr_tree, hf_flip_basic_e, flip_tvb, offset, 4, ENC_BIG_ENDIAN); /* Reserved: 3 bits. */ proto_tree_add_item(basic_hdr_tree, hf_flip_basic_reserved, flip_tvb, offset, 4, ENC_BIG_ENDIAN); /* Flow ID: 28 bits. */ proto_tree_add_item(basic_hdr_tree, hf_flip_basic_flowid, flip_tvb, offset, 4, ENC_BIG_ENDIAN); /* Sequence number: 16 bits. */ proto_tree_add_item(basic_hdr_tree, hf_flip_basic_seqnum, flip_tvb, offset + 4, 2, ENC_BIG_ENDIAN); /* Packet length: 16 bits. */ proto_tree_add_item(basic_hdr_tree, hf_flip_basic_len, flip_tvb, offset + 6, 2, ENC_BIG_ENDIAN); } offset += FLIP_BASIC_HDR_LEN; /* * Process faults found when parsing the basic header. */ if (is_faulty_frame == TRUE) { if (flip_len > frame_len) { col_add_fstr(pinfo->cinfo, COL_INFO, "Length mismatch: frame %d bytes, hdr %d bytes", frame_len, flip_len); } else if (flip_len < FLIP_BASIC_HDR_LEN) { col_add_fstr(pinfo->cinfo, COL_INFO, "Invalid length in basic header: %d bytes", flip_len); } goto DISSECT_FLIP_EXIT; } /* * Now we know that the basic header is sensible. */ payload_len = basic_hdr_len - FLIP_BASIC_HDR_LEN; /* * Dissect extension headers (if any). */ if ((ext_hdr == TRUE) && (payload_len < FLIP_EXTENSION_HDR_MIN_LEN)) { col_add_fstr(pinfo->cinfo, COL_INFO, "Extension header indicated, but not enough data"); goto DISSECT_FLIP_EXIT; } while ((ext_hdr == TRUE) && (payload_len >= FLIP_EXTENSION_HDR_MIN_LEN)) { /* Detect the next header type. */ guint8 ext_hdr_type; gint bytes_handled; guint16 computed_chksum; tvbuff_t *chksum_tvb; ext_hdr_type = tvb_get_guint8(flip_tvb, offset); switch (ext_hdr_type) { case FLIP_CHKSUM: /* Calculate checksum, let the chksum dissector verify it. */ { vec_t vec[2]; SET_CKSUM_VEC_TVB(vec[0], flip_tvb, 0, bytes_dissected + 2); SET_CKSUM_VEC_TVB(vec[1], flip_tvb, bytes_dissected + 4, flip_len - (bytes_dissected + 4)); computed_chksum = in_cksum(&vec[0], 2); /* Checksums handled in network order. */ computed_chksum = g_htons(computed_chksum); } chksum_tvb = tvb_new_subset_length(flip_tvb, offset, FLIP_CHKSUM_HDR_LEN); /* Note that flip_tree is NULL if no details are requested. */ bytes_handled = dissect_flip_chksum_hdr(chksum_tvb, pinfo, flip_tree, computed_chksum, &ext_hdr); bytes_dissected += bytes_handled; payload_len -= bytes_handled; offset += bytes_handled; break; default: /* Unknown header type. */ col_add_fstr(pinfo->cinfo, COL_INFO, "Invalid extension header type 0x%02x", ext_hdr_type); goto DISSECT_FLIP_EXIT; break; } } /* * Show payload (if any) as bytes. */ if (payload_len > 0) { tvbuff_t *payload_tvb; gint data_len; payload_tvb = tvb_new_subset_length(flip_tvb, offset, payload_len); data_len = dissector_try_payload(subdissector_table, payload_tvb, pinfo, tree); if (data_len <= 0) { data_len = call_data_dissector(payload_tvb, pinfo, tree); } bytes_dissected += data_len; } /* if (payload_len > 0) */ DISSECT_FLIP_EXIT: return bytes_dissected; } /* dissect_flip() */ /* Protocol initialization */ void proto_register_flip(void) { static hf_register_info hf[] = { /* * Basic header. */ {&hf_flip_basic_e, {"Extension Header Follows", "flip.basic.e", FT_BOOLEAN, 32, TFS(&tfs_yes_no), 0x80000000, NULL, HFILL} }, {&hf_flip_basic_reserved, {"Reserved", "flip.basic.reserved", FT_UINT32, BASE_DEC, NULL, 0x70000000, "Basic Header Reserved", HFILL} }, {&hf_flip_basic_flowid, {"FlowID", "flip.basic.flowid", FT_UINT32, BASE_HEX, NULL, 0x0FFFFFFF, "Basic Header Flow ID", HFILL} }, {&hf_flip_basic_seqnum, {"Seqnum", "flip.basic.seqnum", FT_UINT16, BASE_DEC_HEX, NULL, 0x0, "Basic Header Sequence Number", HFILL} }, {&hf_flip_basic_len, {"Len", "flip.basic.len", FT_UINT16, BASE_DEC_HEX, NULL, 0x0, "Basic Header Packet Length", HFILL} }, /* * Checksum header. */ {&hf_flip_chksum_etype, {"Extension Type", "flip.chksum.etype", FT_UINT32, BASE_DEC, VALS(flip_etype), 0xFF000000, "Checksum Header Extension Type", HFILL} }, {&hf_flip_chksum_spare, {"Spare", "flip.chksum.spare", FT_UINT32, BASE_DEC_HEX, NULL, 0x00FE0000, "Checksum Header Spare", HFILL} }, {&hf_flip_chksum_e, {"Extension Header Follows", "flip.chksum.e", FT_BOOLEAN, 32, TFS(&tfs_yes_no), 0x00010000, NULL, HFILL} }, {&hf_flip_chksum_chksum, {"Checksum", "flip.chksum.chksum", FT_UINT32, BASE_HEX, NULL, 0x0000FFFF, NULL, HFILL} } }; static gint *ett[] = { &ett_flip, &ett_flip_basic, &ett_flip_chksum, &ett_flip_payload }; module_t *flip_module; proto_flip = proto_register_protocol("NSN FLIP", "FLIP", "flip"); flip_handle = register_dissector("flip", dissect_flip, proto_flip); proto_register_field_array(proto_flip, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); flip_module = prefs_register_protocol_obsolete(proto_flip); /* Register preferences - now obsolete because of Decode As*/ prefs_register_obsolete_preference(flip_module, "decoding_mode"); prefs_register_obsolete_preference(flip_module, "heur_enabled_protocols"); prefs_register_obsolete_preference(flip_module, "heur_decode_rtp"); prefs_register_obsolete_preference(flip_module, "heur_decode_rtcp"); prefs_register_obsolete_preference(flip_module, "forced_protocol"); prefs_register_obsolete_preference(flip_module, "forced_decode"); subdissector_table = register_decode_as_next_proto(proto_flip, "flip.payload", "FLIP payload", flip_prompt); } /* proto_register_flip() */ /* Protocol handoff */ void proto_reg_handoff_flip(void) { dissector_add_uint("ethertype", ETHERTYPE_FLIP, flip_handle); } /* proto_reg_handoff_flip() */ /* * 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: */