/* packet-dhpcv6.c * Routines for DHCPv6 packet disassembly * Jun-ichiro itojun Hagino * * $Id: packet-dhcpv6.c,v 1.4 2002/01/24 09:20:47 guy Exp $ * * The information used comes from: * draft-ietf-dhc-dhcpv6-22.txt * Note that protocol constants are still subject to change, based on IANA * assignment decisions. * * Ethereal - 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. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #ifdef HAVE_SYS_TYPES_H # include #endif #include #include #include #include #include static int proto_dhcpv6 = -1; static int hf_dhcpv6_msgtype = -1; static guint ett_dhcpv6 = -1; static guint ett_dhcpv6_option = -1; #define UDP_PORT_DHCPV6_DOWNSTREAM 546 #define UDP_PORT_DHCPV6_UPSTREAM 547 static const value_string msgtype_vals[] = { { 7, "Reply" }, { 11, "Information request" }, { 0, NULL } }; static const value_string opttype_vals[] = { { 1, "DUID" }, { 11, "DNS servers address" }, { 0, NULL } }; /* Returns the number of bytes consumed by this option. */ static int dhcpv6_option(tvbuff_t *tvb, proto_tree *bp_tree, int off, int eoff, gboolean *at_end) { guint16 opttype; guint16 optlen; proto_item *ti; proto_tree *subtree; int i; struct e_in6_addr in6; guint16 duidtype; /* option type and length must be present */ if (eoff - off < 4) { *at_end = TRUE; return 0; } opttype = tvb_get_ntohs(tvb, off); optlen = tvb_get_ntohs(tvb, off + 2); /* truncated case */ if (eoff - off < 4 + optlen) { *at_end = TRUE; return 0; } ti = proto_tree_add_text(bp_tree, tvb, off, 4 + optlen, "%s", val_to_str(opttype, opttype_vals, "DHCP option %u")); subtree = proto_item_add_subtree(ti, ett_dhcpv6_option); proto_tree_add_text(subtree, tvb, off, 2, "option type: %d", opttype); proto_tree_add_text(subtree, tvb, off + 2, 2, "option length: %d", optlen); off += 4; switch (opttype) { case 1: /* DUID */ if (optlen < 2) { proto_tree_add_text(subtree, tvb, off, optlen, "DUID: malformed option"); break; } duidtype = tvb_get_ntohs(tvb, off); proto_tree_add_text(subtree, tvb, off, 2, "DUID type: %u", duidtype); switch (duidtype) { case 1: if (optlen < 8) { proto_tree_add_text(subtree, tvb, off, optlen, "DUID: malformed option"); break; } /* XXX seconds since Jan 1 2000 */ proto_tree_add_text(subtree, tvb, off + 2, 4, "Time: %u", tvb_get_ntohl(tvb, off + 6)); proto_tree_add_text(subtree, tvb, off + 6, 2, "Hardware type: %u", tvb_get_ntohs(tvb, off + 6)); if (optlen > 8) { proto_tree_add_text(subtree, tvb, off + 8, optlen - 8, "Link-layer address"); } break; case 2: if (optlen < 10) { proto_tree_add_text(subtree, tvb, off, optlen, "DUID: malformed option"); break; } proto_tree_add_text(subtree, tvb, off + 2, 8, "VUID"); if (optlen > 10) { proto_tree_add_text(subtree, tvb, off + 10, optlen - 10, "Domain name"); } break; case 3: if (optlen < 4) { proto_tree_add_text(subtree, tvb, off, optlen, "DUID: malformed option"); break; } proto_tree_add_text(subtree, tvb, off + 2, 2, "Hardware type: %u", tvb_get_ntohs(tvb, off + 10)); if (optlen > 4) { proto_tree_add_text(subtree, tvb, off + 4, optlen - 4, "Link-layer address"); } break; } break; case 11: /* DNS servers address */ if (optlen % 16) { proto_tree_add_text(subtree, tvb, off, optlen, "DNS servers address: malformed option"); break; } for (i = 0; i < optlen; i += 16) { tvb_memcpy(tvb, (guint8 *)&in6, off + i, sizeof(in6)); proto_tree_add_text(subtree, tvb, off + i, sizeof(in6), "DNS servers address: %s", ip6_to_str(&in6)); } break; } return 4 + optlen; } static void dissect_dhcpv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean downstream) { proto_tree *bp_tree = NULL; proto_item *ti; guint8 msgtype; guint32 xid; struct e_in6_addr in6; int off, eoff; gboolean at_end; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "DHCPv6"); if (check_col(pinfo->cinfo, COL_INFO)) col_clear(pinfo->cinfo, COL_INFO); msgtype = tvb_get_guint8(tvb, 0); /* XXX relay agent messages have to be decoded differently */ xid = tvb_get_ntohl(tvb, 0) & 0x00ffffff; if (check_col(pinfo->cinfo, COL_INFO)) { col_set_str(pinfo->cinfo, COL_INFO, downstream ? "DHCPv6 reply" : "DHCPv6 request"); } if (tree) { ti = proto_tree_add_item(tree, proto_dhcpv6, tvb, 0, -1, FALSE); bp_tree = proto_item_add_subtree(ti, ett_dhcpv6); proto_tree_add_uint(bp_tree, hf_dhcpv6_msgtype, tvb, 0, 1, msgtype); proto_tree_add_text(bp_tree, tvb, 1, 3, "XID: 0x%08x", xid); tvb_memcpy(tvb, (guint8 *)&in6, 4, sizeof(in6)); proto_tree_add_text(bp_tree, tvb, 4, sizeof(in6), "Server address: %s", ip6_to_str(&in6)); } off = 20; eoff = tvb_reported_length(tvb); at_end = FALSE; while (off < eoff && !at_end) off += dhcpv6_option(tvb, bp_tree, off, eoff, &at_end); } static void dissect_dhcpv6_downstream(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { dissect_dhcpv6(tvb, pinfo, tree, TRUE); } static void dissect_dhcpv6_upstream(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { dissect_dhcpv6(tvb, pinfo, tree, FALSE); } void proto_register_dhcpv6(void) { static hf_register_info hf[] = { { &hf_dhcpv6_msgtype, { "Message type", "dhcpv6.msgtype", FT_UINT8, BASE_DEC, VALS(msgtype_vals), 0x0, "", HFILL }}, }; static gint *ett[] = { &ett_dhcpv6, &ett_dhcpv6_option, }; proto_dhcpv6 = proto_register_protocol("DHCPv6", "DHCPv6", "dhcpv6"); proto_register_field_array(proto_dhcpv6, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_dhcpv6(void) { dissector_handle_t dhcpv6_handle; dhcpv6_handle = create_dissector_handle(dissect_dhcpv6_downstream, proto_dhcpv6); dissector_add("udp.port", UDP_PORT_DHCPV6_DOWNSTREAM, dhcpv6_handle); dhcpv6_handle = create_dissector_handle(dissect_dhcpv6_upstream, proto_dhcpv6); dissector_add("udp.port", UDP_PORT_DHCPV6_UPSTREAM, dhcpv6_handle); }