/* packet-vssmonitoring.c * Routines for dissection of VSS-monitoring timestamp and portstamp * * Copyright VSS-Monitoring 2011 * * 20111205 - First edition by Sake Blok (sake.blok@SYN-bit.nl) * * Wireshark - Network traffic analyzer * By Gerald Combs * 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 #include #define VSS_NS_MASK 0x3fffffff #define CLKSRC_SHIFT 30 #define CLKSRC_LOCAL 0 #define CLKSRC_NTP 1 #define CLKSRC_GPS 2 #define CLKSRC_PTP 3 static const value_string clksrc_vals[] = { { CLKSRC_LOCAL, "Not Synced" }, { CLKSRC_NTP, "NTP" }, { CLKSRC_GPS, "GPS" }, { CLKSRC_PTP, "PTP" }, { 0, NULL } }; void proto_register_vssmonitoring(void); void proto_reg_handoff_vssmonitoring(void); static int proto_vssmonitoring = -1; static int hf_vssmonitoring_time = -1; static int hf_vssmonitoring_clksrc = -1; static int hf_vssmonitoring_srcport = -1; static gint ett_vssmonitoring = -1; static int dissect_vssmonitoring(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { proto_tree *ti = NULL; proto_tree *vssmonitoring_tree = NULL; guint offset = 0; guint trailer_len; nstime_t vssmonitoring_time; guint8 vssmonitoring_clksrc = 0; guint16 vssmonitoring_srcport = 0; struct tm *tmp; /* First get the length of the trailer */ trailer_len = tvb_reported_length(tvb); /* The trailer length is a sum (of any combination) of: * timestamp (8 bytes) * port stamp (1 or 2 bytes) * fcs (4 bytes) * * The FCS is dissected by our caller, so we check for a trailer * with a length that includes one or more of a time stamp and * a 1-byte or 2-byte port stamp. * * See * * http://www.vssmonitoring.com/portals/application_note/Port%20and%20Time%20Stamping.pdf * * (although that speaks of 2-byte port stamps as being for a "future * release"). * * This means a trailer length must not be more than 14 bytes, * and: * * must not be 3 modulo 3 (as it can't have both a 1-byte * and a 2-byte port stamp); * * if it's less than 8 bytes, must not be 0 modulo 3 (as * it must have a 1-byte or 2-byte port stamp, given that * it has no timestamp). */ if ( trailer_len > 14 ) return 0; /* ... and also a 1-byte port stamp can not co-exist with a 2-byte * portstamp */ if ( (trailer_len & 3) == 3 ) return 0; /* ... and if you have neither a time stamp nor a port stamp, * you don't have a trailer */ if ( (trailer_len & 3) == 0 && trailer_len < 8 ) return 0; if ( trailer_len >= 8 ) { vssmonitoring_time.secs = tvb_get_ntohl(tvb, offset); vssmonitoring_time.nsecs = tvb_get_ntohl(tvb, offset + 4); vssmonitoring_clksrc = (guint8)(((guint32)vssmonitoring_time.nsecs) >> CLKSRC_SHIFT); vssmonitoring_time.nsecs &= VSS_NS_MASK; /* The timestamp will be based on the uptime until the TAP is completely booted, * this takes about 60s, but use 1 hour to be sure */ /* Probably just null data to fill up a short frame. * FIXME: Should be made even stricter. */ if (vssmonitoring_time.secs == 0) return 0; if (vssmonitoring_time.secs > 3600) { /* Check whether the timestamp in the PCAP header and the VSS-Monitoring * differ less than 30 days, otherwise, this might not be a VSS-Monitoring * timestamp */ if ( vssmonitoring_time.secs > pinfo->abs_ts.secs ) { if ( vssmonitoring_time.secs - pinfo->abs_ts.secs > 2592000 ) /* 30 days */ return 0; } else { if ( pinfo->abs_ts.secs - vssmonitoring_time.secs > 2592000 ) /* 30 days */ return 0; } } /* The nanoseconds field should be less than 1000000000 */ if ( vssmonitoring_time.nsecs >= 1000000000 ) return 0; } /* All systems are go, lets dissect the VSS-Monitoring trailer */ if (tree) { ti = proto_tree_add_item(tree, proto_vssmonitoring, tvb, 0, (trailer_len & 0xb), ENC_NA); vssmonitoring_tree = proto_item_add_subtree(ti, ett_vssmonitoring); } /* Do we have a timestamp? */ if ( trailer_len >= 8 ) { if (tree) { proto_tree_add_time(vssmonitoring_tree, hf_vssmonitoring_time, tvb, offset, 8, &vssmonitoring_time); proto_tree_add_uint(vssmonitoring_tree, hf_vssmonitoring_clksrc, tvb, offset + 4, 1, vssmonitoring_clksrc); tmp = localtime(&vssmonitoring_time.secs); if (tmp) proto_item_append_text(ti, ", Timestamp: %02d:%02d:%02d.%09ld", tmp->tm_hour, tmp->tm_min, tmp->tm_sec,(long)vssmonitoring_time.nsecs); else proto_item_append_text(ti, ", Timestamp: "); } offset += 8; } /* Do we have a portstamp? */ if ( trailer_len & 3) { if ( trailer_len & 1) { vssmonitoring_srcport = (guint16)tvb_get_guint8(tvb, offset); if (tree) proto_tree_add_item(vssmonitoring_tree, hf_vssmonitoring_srcport, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; } else if ( trailer_len & 2) { vssmonitoring_srcport = tvb_get_ntohs(tvb, offset); if (tree) proto_tree_add_item(vssmonitoring_tree, hf_vssmonitoring_srcport, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; } if (tree) proto_item_append_text(ti, ", Source Port: %d", vssmonitoring_srcport); } return offset; } void proto_register_vssmonitoring(void) { static hf_register_info hf[] = { { &hf_vssmonitoring_time, { "Time Stamp", "vssmonitoring.time", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0, "VSS-Monitoring Time Stamp", HFILL }}, { &hf_vssmonitoring_clksrc, { "Clock Source", "vssmonitoring.clksrc", FT_UINT8, BASE_DEC, VALS(clksrc_vals), 0x0, "VSS-Monitoring Clock Source", HFILL }}, { &hf_vssmonitoring_srcport, { "Src Port", "vssmonitoring.srcport", FT_UINT16, BASE_DEC, NULL, 0x0, "VSS-Monitoring Source Port", HFILL }} }; static gint *ett[] = { &ett_vssmonitoring }; module_t *vssmonitoring_module; proto_vssmonitoring = proto_register_protocol("VSS-Monitoring ethernet trailer", "VSS-Monitoring", "vssmonitoring"); proto_register_field_array(proto_vssmonitoring, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); vssmonitoring_module = prefs_register_protocol(proto_vssmonitoring, NULL); prefs_register_obsolete_preference(vssmonitoring_module, "use_heuristics"); } void proto_reg_handoff_vssmonitoring(void) { heur_dissector_add("eth.trailer", dissect_vssmonitoring, "VSS-Monitoring ethernet trailer", "vssmonitoring_eth", proto_vssmonitoring, HEURISTIC_ENABLE); } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local Variables: * c-basic-offset: 2 * tab-width: 8 * indent-tabs-mode: nil * End: * * ex: set shiftwidth=2 tabstop=8 expandtab: * :indentSize=2:tabSize=8:noTabs=true: */