/* packet-mpls.c * Routines for MPLS data packet disassembly * RFC 3032 * * (c) Copyright Ashok Narayanan * * (c) Copyright 2006, _FF_ Francesco Fondelli * added MPLS OAM support, ITU-T Y.1711 * * $Id$ * * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* * NOTES * * This module defines routines to handle Ethernet-encapsulated MPLS IP packets. * It should implement all the functionality in * Multicast MPLS support is not tested yet */ /* FF NOTES * * The OAM patch should dissect OAM pdus as described in ITU-T Y.1711 */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include "packet-ppp.h" #include "packet-mpls.h" static gint proto_mpls = -1; static gint ett_mpls = -1; static gint ett_mpls_control = -1; static gint ett_mpls_oam = -1; const value_string special_labels[] = { {LABEL_IP4_EXPLICIT_NULL, "IPv4 Explicit-Null"}, {LABEL_ROUTER_ALERT, "Router Alert"}, {LABEL_IP6_EXPLICIT_NULL, "IPv6 Explicit-Null"}, {LABEL_IMPLICIT_NULL, "Implicit-Null"}, {LABEL_OAM_ALERT, "OAM Alert"}, {0, NULL } }; /* MPLS filter values */ enum mpls_filter_keys { /* Is the packet MPLS-encapsulated? */ /* MPLSF_PACKET,*/ /* MPLS encap properties */ MPLSF_LABEL, MPLSF_EXP, MPLSF_BOTTOM_OF_STACK, MPLSF_TTL, MPLSF_MAX }; static int mpls_filter[MPLSF_MAX]; static int hf_mpls_control_control = -1; static int hf_mpls_control_res = -1; static int hf_mpls_oam_function_type = -1; static int hf_mpls_oam_ttsi = -1; static int hf_mpls_oam_frequency = -1; static int hf_mpls_oam_defect_type = -1; static int hf_mpls_oam_defect_location = -1; static int hf_mpls_oam_bip16 = -1; static const value_string oam_function_type_vals[] = { {0x00, "Reserved"}, {0x01, "CV (Connectivity Verification)"}, {0x02, "FDI (Forward Defect Indicator)"}, {0x03, "BDI (Backward Defect Indicator)"}, {0x04, "Reserved for Performance packets"}, {0x05, "Reserved for LB-Req (Loopback Request)"}, {0x06, "Reserved for LB-Rsp (Loopback Response)"}, {0x07, "FDD (Fast Failure Detection)"}, {0, NULL } }; static const value_string oam_frequency_vals[] = { {0x00, "Reserved"}, {0x01, "10 ms"}, {0x02, "20 ms"}, {0x03, "50 ms (default value)"}, {0x04, "100 ms"}, {0x05, "200 ms"}, {0x06, "500 ms"}, /* 7-255 Reserved */ {0, NULL } }; static const value_string oam_defect_type_vals[] = { {0x0000, "Reserved"}, {0x0101, "dServer"}, {0x0102, "dPeerME"}, {0x0201, "dLOCV"}, {0x0202, "dTTSI_Mismatch"}, {0x0203, "dTTSI_Mismerge"}, {0x0204, "dExcess"}, {0x02FF, "dUnknown"}, {0xFFFF, "Reserved"}, {0, NULL } }; static hf_register_info mplsf_info[] = { /* {&mpls_filter[MPLSF_PACKET], {"MPLS Label Switched Packet", "mpls", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }},*/ {&mpls_filter[MPLSF_LABEL], {"MPLS Label", "mpls.label", FT_UINT32, BASE_DEC, VALS(special_labels), 0x0, "", HFILL }}, {&mpls_filter[MPLSF_EXP], {"MPLS Experimental Bits", "mpls.exp", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, {&mpls_filter[MPLSF_BOTTOM_OF_STACK], {"MPLS Bottom Of Label Stack", "mpls.bottom", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, {&mpls_filter[MPLSF_TTL], {"MPLS TTL", "mpls.ttl", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, {&hf_mpls_control_control, {"MPLS Control Channel", "mpls.cw.control", FT_UINT8, BASE_DEC, NULL, 0xF0, "First nibble", HFILL }}, {&hf_mpls_control_res, {"Reserved", "mpls.cw.res", FT_UINT16, BASE_HEX, NULL, 0xFFF, "Reserved", HFILL }}, /* OAM header fields */ {&hf_mpls_oam_function_type, {"Function Type", "mpls.oam.function_type", FT_UINT8, BASE_HEX, VALS(oam_function_type_vals), 0x0, "Function Type codepoint", HFILL }}, {&hf_mpls_oam_ttsi, {"Trail Termination Source Identifier", "mpls.oam.ttsi", FT_UINT32, BASE_HEX, NULL, 0x0, "Trail Termination Source Identifier", HFILL }}, {&hf_mpls_oam_frequency, {"Frequency", "mpls.oam.frequency", FT_UINT8, BASE_HEX, VALS(oam_frequency_vals), 0x0, "Frequency of probe injection", HFILL }}, {&hf_mpls_oam_defect_type, {"Defect Type", "mpls.oam.defect_type", FT_UINT16, BASE_HEX, VALS(oam_defect_type_vals), 0x0, "Defect Type", HFILL }}, {&hf_mpls_oam_defect_location, {"Defect Location (AS)", "mpls.oam.defect_location", FT_UINT32, BASE_DEC, NULL, 0x0, "Defect Location", HFILL }}, {&hf_mpls_oam_bip16, {"BIP16", "mpls.oam.bip16", FT_UINT16, BASE_HEX, NULL, 0x0, "BIP16", HFILL }}, }; static dissector_handle_t ipv4_handle; static dissector_handle_t ipv6_handle; static dissector_handle_t eth_withoutfcs_handle; static dissector_handle_t data_handle; static dissector_table_t ppp_subdissector_table; /* * Given a 4-byte MPLS label starting at offset "offset", in tvbuff "tvb", * decode it. * Return the label in "label", EXP bits in "exp", * bottom_of_stack in "bos", and TTL in "ttl" */ void decode_mpls_label(tvbuff_t *tvb, int offset, guint32 *label, guint8 *exp, guint8 *bos, guint8 *ttl) { guint8 octet0 = tvb_get_guint8(tvb, offset+0); guint8 octet1 = tvb_get_guint8(tvb, offset+1); guint8 octet2 = tvb_get_guint8(tvb, offset+2); *label = (octet0 << 12) + (octet1 << 4) + ((octet2 >> 4) & 0xff); *exp = (octet2 >> 1) & 0x7; *bos = (octet2 & 0x1); *ttl = tvb_get_guint8(tvb, offset+3); } static void dissect_mpls_control(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_tree *mpls_control_tree = NULL; proto_item *ti; tvbuff_t *next_tvb; guint8 ctrl; guint16 res, ppp_proto; if (tvb_reported_length_remaining(tvb, 0) < 4){ if(tree) proto_tree_add_text(tree, tvb, 0, -1, "Error processing Message"); return; } ctrl = (tvb_get_guint8(tvb, 0) & 0xF0) >> 4; res = tvb_get_ntohs(tvb, 0) & 0x0FFF; ppp_proto = tvb_get_ntohs(tvb, 2); if (tree) { ti = proto_tree_add_text(tree, tvb, 0, 4, "MPLS PW Control Channel Header"); mpls_control_tree = proto_item_add_subtree(ti, ett_mpls_control); if(mpls_control_tree == NULL) return; proto_tree_add_uint_format(mpls_control_tree, hf_mpls_control_control, tvb, 0, 1, ctrl, "Control Channel: 0x%1x", ctrl); proto_tree_add_uint_format(mpls_control_tree, hf_mpls_control_res, tvb, 0, 2, res, "Reserved: 0x%03x", res); proto_tree_add_text(mpls_control_tree, tvb, 2, 2, "PPP DLL Protocol Number: %s (0x%04X)", val_to_str(ppp_proto, ppp_vals, "Unknown"), ppp_proto); } next_tvb = tvb_new_subset(tvb, 4, -1, -1); if (!dissector_try_port(ppp_subdissector_table, ppp_proto, next_tvb, pinfo, tree)) { call_dissector(data_handle, next_tvb, pinfo, tree); } } static void dissect_mpls_oam_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_tree *mpls_tree, int offset, guint8 exp, guint8 bos, guint8 ttl) { proto_tree *mpls_oam_tree = NULL; proto_item *ti = NULL; int functype = -1; const guint8 allone[] = { 0xff, 0xff }; const guint8 allzero[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; /* if called with main tree == null just set col info with func type string and return */ if (!tree) { if (check_col(pinfo->cinfo, COL_INFO)) { if (tvb_bytes_exist(tvb, offset, 1)) { functype = tvb_get_guint8(tvb, offset); col_append_fstr(pinfo->cinfo, COL_INFO, " (OAM: %s)", (functype == 0x01) ? "CV" : (functype == 0x02) ? "FDI" : (functype == 0x03) ? "BDI" : (functype == 0x07) ? "FDD" : "reserved/unknown"); } } return; } /* sanity checks */ if (!mpls_tree) return; if (!tvb_bytes_exist(tvb, offset, 44)) { /* ITU-T Y.1711, 5.3: OAM pdus must have a minimum payload length of 44 bytes */ proto_tree_add_text(mpls_tree, tvb, offset, -1, "Error: must have a minimum payload length of 44 bytes"); return; } ti = proto_tree_add_text(mpls_tree, tvb, offset, 44, "MPLS Operation & Maintenance"); mpls_oam_tree = proto_item_add_subtree(ti, ett_mpls_oam); if (!mpls_oam_tree) return; /* checks for exp, bos and ttl encoding */ if (exp!=0) proto_tree_add_text(mpls_oam_tree, tvb, offset - 2, 1, "Warning: Exp bits should be 0 for OAM"); if (bos!=1) proto_tree_add_text(mpls_oam_tree, tvb, offset - 2, 1, "Warning: S bit should be 1 for OAM"); if (ttl!=1) proto_tree_add_text(mpls_oam_tree, tvb, offset - 1, 1, "Warning: TTL should be 1 for OAM"); /* starting dissection */ functype = tvb_get_guint8(tvb, offset); proto_tree_add_item(mpls_oam_tree, hf_mpls_oam_function_type, tvb, offset, 1, TRUE); offset++; switch(functype) { case 0x01: /* CV */ { guint32 lsrid_ipv4addr; /* 3 octets reserved (all 0x00) */ if (tvb_memeql(tvb, offset, allzero, 3) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 3, "Error: these bytes are reserved and must be 0x00"); } offset+=3; /* ttsi (ipv4 flavor as in RFC 2373) */ if (tvb_memeql(tvb, offset, allzero, 10) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 10, "Error: these bytes are padding and must be 0x00"); } offset+=10; if (tvb_memeql(tvb, offset, allone, 2) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 2, "Error: these bytes are padding and must be 0xFF"); } offset+=2; lsrid_ipv4addr = tvb_get_ipv4(tvb, offset); proto_tree_add_text(mpls_oam_tree, tvb, offset, 4, "LSR ID: %s", ip_to_str((guint8 *)&lsrid_ipv4addr)); offset+=4; proto_tree_add_text(mpls_oam_tree, tvb, offset, 4, "LSP ID: %d", tvb_get_ntohl(tvb, offset)); offset+=4; /* 18 octets of padding (all 0x00) */ if (tvb_memeql(tvb, offset, allzero, 18) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 18, "Error: these bytes are padding and must be 0x00"); } offset+=18; } break; case 0x02: /* FDI */ case 0x03: /* BDI */ { guint32 lsrid_ipv4addr; /* 1 octets reserved (all 0x00) */ if (tvb_memeql(tvb, offset, allzero, 1) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 3, "Error: this byte is reserved and must be 0x00"); } offset++; proto_tree_add_item(mpls_oam_tree, hf_mpls_oam_defect_type, tvb, offset, 2, TRUE); offset+=2; /* ttsi (ipv4 flavor as in RFC 2373) is optional if not used must be set to all 0x00 */ if (tvb_memeql(tvb, offset, allzero, 20) == 0) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 20, "TTSI not preset (optional for FDI/BDI)"); offset+=20; } else { if (tvb_memeql(tvb, offset, allzero, 10) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 10, "Error: these bytes are padding and must be 0x00"); } offset+=10; if (tvb_memeql(tvb, offset, allone, 2) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 2, "Error: these bytes are padding and must be 0xFF"); } offset+=2; lsrid_ipv4addr = tvb_get_ipv4(tvb, offset); proto_tree_add_text(mpls_oam_tree, tvb, offset, 4, "LSR ID: %s", ip_to_str((guint8 *)&lsrid_ipv4addr)); offset+=4; proto_tree_add_text(mpls_oam_tree, tvb, offset, 4, "LSP ID: %d", tvb_get_ntohl(tvb, offset)); offset+=4; } /* defect location */ proto_tree_add_item(mpls_oam_tree, hf_mpls_oam_defect_location, tvb, offset, 4, TRUE); offset+=4; /* 14 octets of padding (all 0x00) */ if (tvb_memeql(tvb, offset, allzero, 14) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 14, "Error: these bytes are padding and must be 0x00"); } offset+=14; } break; case 0x07: /* FDD */ { guint32 lsrid_ipv4addr; /* 3 octets reserved (all 0x00) */ if (tvb_memeql(tvb, offset, allzero, 3) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 3, "Error: these bytes are reserved and must be 0x00"); } offset+=3; /* ttsi (ipv4 flavor as in RFC 2373) */ if (tvb_memeql(tvb, offset, allzero, 10) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 10, "Error: these bytes are padding and must be 0x00"); } offset+=10; if (tvb_memeql(tvb, offset, allone, 2) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 2, "Error: these bytes are padding and must be 0xFF"); } offset+=2; lsrid_ipv4addr = tvb_get_ipv4(tvb, offset); proto_tree_add_text(mpls_oam_tree, tvb, offset, 4, "LSR ID: %s", ip_to_str((guint8 *)&lsrid_ipv4addr)); offset+=4; proto_tree_add_text(mpls_oam_tree, tvb, offset, 4, "LSP ID: %d", tvb_get_ntohl(tvb, offset)); offset+=4; proto_tree_add_item(mpls_oam_tree, hf_mpls_oam_frequency, tvb, offset, 1, TRUE); offset++; /* 17 octets of padding (all 0x00) */ if (tvb_memeql(tvb, offset, allzero, 17) == -1) { proto_tree_add_text(mpls_oam_tree, tvb, offset, 17, "Error: these bytes are padding and must be 0x00"); } offset+=17; } break; default: proto_tree_add_text(mpls_oam_tree, tvb, offset - 1, -1, "Unknown MPLS OAM pdu"); return; } /* BIP16 */ proto_tree_add_item(mpls_oam_tree, hf_mpls_oam_bip16, tvb, offset, 2, TRUE); offset+=2; } static void dissect_mpls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { int offset = 0; guint32 label; guint8 exp; guint8 bos; guint8 ttl; guint8 ipvers; proto_tree *mpls_tree = NULL; proto_item *ti; tvbuff_t *next_tvb; if (check_col(pinfo->cinfo, COL_PROTOCOL)) { col_set_str(pinfo->cinfo,COL_PROTOCOL, "MPLS"); } if (check_col(pinfo->cinfo,COL_INFO)) { col_add_fstr(pinfo->cinfo,COL_INFO,"MPLS Label Switched Packet"); } /* Start Decoding Here. */ while (tvb_reported_length_remaining(tvb, offset) > 0) { decode_mpls_label(tvb, offset, &label, &exp, &bos, &ttl); if (tree) { ti = proto_tree_add_item(tree, proto_mpls, tvb, offset, 4, FALSE); mpls_tree = proto_item_add_subtree(ti, ett_mpls); proto_item_append_text(ti, ", Label: %u", label); if (label <= LABEL_MAX_RESERVED){ proto_tree_add_uint_format(mpls_tree, mpls_filter[MPLSF_LABEL], tvb, offset, 3, label, "MPLS Label: %u (%s)", label, val_to_str(label, special_labels, "Reserved - Unknown")); proto_item_append_text(ti, " (%s)", val_to_str(label, special_labels, "Reserved - Unknown")); } else { proto_tree_add_uint_format(mpls_tree, mpls_filter[MPLSF_LABEL], tvb, offset, 3, label, "MPLS Label: %u", label); } proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_EXP], tvb, offset+2,1, exp); proto_item_append_text(ti, ", Exp: %u", exp); proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_BOTTOM_OF_STACK], tvb, offset+2,1, bos); proto_item_append_text(ti, ", S: %u", bos); proto_tree_add_uint(mpls_tree,mpls_filter[MPLSF_TTL], tvb, offset+3,1, ttl); proto_item_append_text(ti, ", TTL: %u", ttl); } if (label == LABEL_OAM_ALERT) { /* OAM pdus are injected in normal data plane flow in order to test a LSP, * they carry no user data. */ dissect_mpls_oam_pdu(tvb, pinfo, tree, mpls_tree, offset + 4, exp, bos, ttl); return; } offset += 4; if (bos) break; } next_tvb = tvb_new_subset(tvb, offset, -1, -1); ipvers = (tvb_get_guint8(tvb, offset) >> 4) & 0x0F; if (ipvers == 6) { call_dissector(ipv6_handle, next_tvb, pinfo, tree); } else if (ipvers == 4) { call_dissector(ipv4_handle, next_tvb, pinfo, tree); } else if (ipvers == 1) { dissect_mpls_control(next_tvb, pinfo, tree); } else { call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree); } } void proto_register_mpls(void) { static gint *ett[] = { &ett_mpls, &ett_mpls_control, &ett_mpls_oam, }; proto_mpls = proto_register_protocol("MultiProtocol Label Switching Header", "MPLS", "mpls"); proto_register_field_array(proto_mpls, mplsf_info, array_length(mplsf_info)); proto_register_subtree_array(ett, array_length(ett)); register_dissector("mpls", dissect_mpls, proto_mpls); } void proto_reg_handoff_mpls(void) { dissector_handle_t mpls_handle; /* * Get a handle for the IPv4 and IPv6 dissectors and PPP protocol dissector table. */ ipv4_handle = find_dissector("ip"); ipv6_handle = find_dissector("ipv6"); eth_withoutfcs_handle = find_dissector("eth_withoutfcs"); data_handle = find_dissector("data"); ppp_subdissector_table = find_dissector_table("ppp.protocol"); mpls_handle = create_dissector_handle(dissect_mpls, proto_mpls); dissector_add("ethertype", ETHERTYPE_MPLS, mpls_handle); dissector_add("ethertype", ETHERTYPE_MPLS_MULTI, mpls_handle); dissector_add("ppp.protocol", PPP_MPLS_UNI, mpls_handle); dissector_add("ppp.protocol", PPP_MPLS_MULTI, mpls_handle); dissector_add("chdlctype", ETHERTYPE_MPLS, mpls_handle); dissector_add("chdlctype", ETHERTYPE_MPLS_MULTI, mpls_handle); dissector_add("gre.proto", ETHERTYPE_MPLS, mpls_handle); dissector_add("gre.proto", ETHERTYPE_MPLS_MULTI, mpls_handle); }