/* packet-aarp.c * Routines for Appletalk ARP packet disassembly * * $Id$ * * Simon Wilkinson * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 * * 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 #include #include #include #include #include "etypes.h" static int proto_aarp = -1; static int hf_aarp_hard_type = -1; static int hf_aarp_proto_type = -1; static int hf_aarp_hard_size = -1; static int hf_aarp_proto_size = -1; static int hf_aarp_opcode = -1; static int hf_aarp_src_hw = -1; static int hf_aarp_src_hw_mac = -1; static int hf_aarp_src_proto = -1; static int hf_aarp_src_proto_id = -1; static int hf_aarp_dst_hw = -1; static int hf_aarp_dst_hw_mac = -1; static int hf_aarp_dst_proto = -1; static int hf_aarp_dst_proto_id = -1; static gint ett_aarp = -1; #ifndef AARP_REQUEST #define AARP_REQUEST 0x0001 #endif #ifndef AARP_REPLY #define AARP_REPLY 0x0002 #endif #ifndef AARP_PROBE #define AARP_PROBE 0x0003 #endif /* The following is screwed up shit to deal with the fact that the linux kernel edits the packet inline. */ #define AARP_REQUEST_SWAPPED 0x0100 #define AARP_REPLY_SWAPPED 0x0200 #define AARP_PROBE_SWAPPED 0x0300 static const value_string op_vals[] = { {AARP_REQUEST, "request" }, {AARP_REPLY, "reply" }, {AARP_PROBE, "probe" }, {AARP_REQUEST_SWAPPED, "request" }, {AARP_REPLY_SWAPPED, "reply" }, {AARP_PROBE_SWAPPED, "probe" }, {0, NULL } }; /* AARP protocol HARDWARE identifiers. */ #define AARPHRD_ETHER 1 /* Ethernet 10Mbps */ #define AARPHRD_TR 2 /* Token Ring */ static const value_string hrd_vals[] = { {AARPHRD_ETHER, "Ethernet" }, {AARPHRD_TR, "Token Ring" }, {0, NULL } }; /* * Given the hardware address type and length, check whether an address * is an Ethernet address - the address must be of type "Ethernet" or * "Token Ring", and the length must be 6 bytes. */ #define AARP_HW_IS_ETHER(ar_hrd, ar_hln) \ (((ar_hrd) == AARPHRD_ETHER || (ar_hrd) == AARPHRD_TR) \ && (ar_hln) == 6) /* * Given the protocol address type and length, check whether an address * is an Appletalk address - the address must be of type "Appletalk", * and the length must be 4 bytes. */ #define AARP_PRO_IS_ATALK(ar_pro, ar_pln) \ ((ar_pro) == ETHERTYPE_ATALK && (ar_pln) == 4) static gchar * atalkid_to_str(const guint8 *ad) { gint node; static gchar str[3][16]; static gchar *cur; if (cur == &str[0][0]) { cur = &str[1][0]; } else if (cur == &str[1][0]) { cur = &str[2][0]; } else { cur = &str[0][0]; } node=ad[1]<<8|ad[2]; sprintf(cur, "%d.%d",node,ad[3]); return cur; } static gchar * aarphrdaddr_to_str(const guint8 *ad, int ad_len, guint16 type) { if (AARP_HW_IS_ETHER(type, ad_len)) { /* Ethernet address (or Token Ring address, which is the same type of address). */ return ether_to_str(ad); } return bytes_to_str(ad, ad_len); } static gchar * aarpproaddr_to_str(const guint8 *ad, int ad_len, guint16 type) { if (AARP_PRO_IS_ATALK(type, ad_len)) { /* Appletalk address. */ return atalkid_to_str(ad); } return bytes_to_str(ad, ad_len); } /* Offsets of fields within an AARP packet. */ #define AR_HRD 0 #define AR_PRO 2 #define AR_HLN 4 #define AR_PLN 5 #define AR_OP 6 #define MIN_AARP_HEADER_SIZE 8 static void dissect_aarp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { guint16 ar_hrd; guint16 ar_pro; guint8 ar_hln; guint8 ar_pln; guint16 ar_op; proto_tree *aarp_tree; proto_item *ti; gchar *op_str; int sha_offset, spa_offset, tha_offset, tpa_offset; const guint8 *sha_val, *spa_val, *tha_val, *tpa_val; gchar *sha_str, *spa_str, *tha_str, *tpa_str; if(check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "AARP"); if(check_col(pinfo->cinfo, COL_INFO)) col_clear(pinfo->cinfo, COL_INFO); ar_hrd = tvb_get_ntohs(tvb, AR_HRD); ar_pro = tvb_get_ntohs(tvb, AR_PRO); ar_hln = tvb_get_guint8(tvb, AR_HLN); ar_pln = tvb_get_guint8(tvb, AR_PLN); ar_op = tvb_get_ntohs(tvb, AR_OP); /* Get the offsets of the addresses. */ sha_offset = MIN_AARP_HEADER_SIZE; spa_offset = sha_offset + ar_hln; tha_offset = spa_offset + ar_pln; tpa_offset = tha_offset + ar_hln; /* Extract the addresses. */ sha_val = tvb_get_ptr(tvb, sha_offset, ar_hln); sha_str = aarphrdaddr_to_str(sha_val, ar_hln, ar_hrd); spa_val = tvb_get_ptr(tvb, spa_offset, ar_pln); spa_str = aarpproaddr_to_str(spa_val, ar_pln, ar_pro); tha_val = tvb_get_ptr(tvb, tha_offset, ar_hln); tha_str = aarphrdaddr_to_str(tha_val, ar_hln, ar_hrd); tpa_val = tvb_get_ptr(tvb, tpa_offset, ar_pln); tpa_str = aarpproaddr_to_str(tpa_val, ar_pln, ar_pro); if (check_col(pinfo->cinfo, COL_INFO)) { switch (ar_op) { case AARP_REQUEST: case AARP_REQUEST_SWAPPED: col_add_fstr(pinfo->cinfo, COL_INFO, "Who has %s? Tell %s", tpa_str, spa_str); break; case AARP_REPLY: case AARP_REPLY_SWAPPED: col_add_fstr(pinfo->cinfo, COL_INFO, "%s is at %s", spa_str, sha_str); break; case AARP_PROBE: case AARP_PROBE_SWAPPED: col_add_fstr(pinfo->cinfo, COL_INFO, "Is there a %s", tpa_str); break; default: col_add_fstr(pinfo->cinfo, COL_INFO, "Unknown AARP opcode 0x%04x", ar_op); break; } } if (tree) { if ((op_str = match_strval(ar_op, op_vals))) ti = proto_tree_add_protocol_format(tree, proto_aarp, tvb, 0, MIN_AARP_HEADER_SIZE + 2*ar_hln + 2*ar_pln, "AppleTalk Address Resolution Protocol (%s)", op_str); else ti = proto_tree_add_protocol_format(tree, proto_aarp, tvb, 0, MIN_AARP_HEADER_SIZE + 2*ar_hln + 2*ar_pln, "AppleTalk Address Resolution Protocol (opcode 0x%04x)", ar_op); aarp_tree = proto_item_add_subtree(ti, ett_aarp); proto_tree_add_uint(aarp_tree, hf_aarp_hard_type, tvb, AR_HRD, 2, ar_hrd); proto_tree_add_uint(aarp_tree, hf_aarp_proto_type, tvb, AR_PRO, 2, ar_pro); proto_tree_add_uint(aarp_tree, hf_aarp_hard_size, tvb, AR_HLN, 1, ar_hln); proto_tree_add_uint(aarp_tree, hf_aarp_proto_size, tvb, AR_PLN, 1, ar_pln); proto_tree_add_uint(aarp_tree, hf_aarp_opcode, tvb, AR_OP, 2, ar_op); if (ar_hln != 0) { proto_tree_add_item(aarp_tree, AARP_HW_IS_ETHER(ar_hrd, ar_hln) ? hf_aarp_src_hw_mac : hf_aarp_src_hw, tvb, sha_offset, ar_hln, FALSE); } if (ar_pln != 0) { if (AARP_PRO_IS_ATALK(ar_pro, ar_pln)) { proto_tree_add_bytes_format(aarp_tree, hf_aarp_src_proto_id, tvb, spa_offset, ar_pln, spa_val, "Sender ID: %s", spa_str); } else { proto_tree_add_bytes_format(aarp_tree, hf_aarp_src_proto, tvb, spa_offset, ar_pln, spa_val, "Sender protocol address: %s", spa_str); } } if (ar_hln != 0) { proto_tree_add_item(aarp_tree, AARP_HW_IS_ETHER(ar_hrd, ar_hln) ? hf_aarp_dst_hw_mac : hf_aarp_dst_hw, tvb, tha_offset, ar_hln, FALSE); } if (ar_pln != 0) { if (AARP_PRO_IS_ATALK(ar_pro, ar_pln)) { proto_tree_add_bytes_format(aarp_tree, hf_aarp_dst_proto_id, tvb, tpa_offset, ar_pln, tpa_val, "Target ID: %s", tpa_str); } else { proto_tree_add_bytes_format(aarp_tree, hf_aarp_dst_proto, tvb, tpa_offset, ar_pln, tpa_val, "Target protocol address: %s", tpa_str); } } } } void proto_register_aarp(void) { static hf_register_info hf[] = { { &hf_aarp_hard_type, { "Hardware type", "aarp.hard.type", FT_UINT16, BASE_HEX, VALS(hrd_vals), 0x0, "", HFILL }}, { &hf_aarp_proto_type, { "Protocol type", "aarp.proto.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0, "", HFILL }}, { &hf_aarp_hard_size, { "Hardware size", "aarp.hard.size", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_aarp_proto_size, { "Protocol size", "aarp.proto.size", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL }}, { &hf_aarp_opcode, { "Opcode", "aarp.opcode", FT_UINT16, BASE_DEC, VALS(op_vals), 0x0, "", HFILL }}, { &hf_aarp_src_hw, { "Sender hardware address", "aarp.src.hw", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_aarp_src_hw_mac, { "Sender MAC address", "aarp.src.hw_mac", FT_ETHER, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_aarp_src_proto, { "Sender protocol address", "aarp.src.proto", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_aarp_src_proto_id, { "Sender ID", "aarp.src.proto_id", FT_BYTES, BASE_HEX, NULL, 0x0, "", HFILL }}, { &hf_aarp_dst_hw, { "Target hardware address", "aarp.dst.hw", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_aarp_dst_hw_mac, { "Target MAC address", "aarp.dst.hw_mac", FT_ETHER, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_aarp_dst_proto, { "Target protocol address", "aarp.dst.proto", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL }}, { &hf_aarp_dst_proto_id, { "Target ID", "aarp.dst.proto_id", FT_BYTES, BASE_HEX, NULL, 0x0, "", HFILL }}, }; static gint *ett[] = { &ett_aarp, }; proto_aarp = proto_register_protocol("Appletalk Address Resolution Protocol", "AARP", "aarp"); proto_register_field_array(proto_aarp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_aarp(void) { dissector_handle_t aarp_handle; aarp_handle = create_dissector_handle(dissect_aarp, proto_aarp); dissector_add("ethertype", ETHERTYPE_AARP, aarp_handle); dissector_add("chdlctype", ETHERTYPE_AARP, aarp_handle); }