2 * Routines for Appletalk ARP packet disassembly
4 * $Id: packet-aarp.c,v 1.25 2000/11/19 08:53:54 guy Exp $
6 * Simon Wilkinson <sxw@dcs.ed.ac.uk>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 #ifdef HAVE_SYS_TYPES_H
28 # include <sys/types.h>
37 static int proto_aarp = -1;
38 static int hf_aarp_hard_type = -1;
39 static int hf_aarp_proto_type = -1;
40 static int hf_aarp_hard_size = -1;
41 static int hf_aarp_proto_size = -1;
42 static int hf_aarp_opcode = -1;
43 static int hf_aarp_src_ether = -1;
44 static int hf_aarp_src_id = -1;
45 static int hf_aarp_dst_ether = -1;
46 static int hf_aarp_dst_id = -1;
48 static gint ett_aarp = -1;
51 #define AARP_REQUEST 0x0001
54 #define AARP_REPLY 0x0002
57 #define AARP_PROBE 0x0003
60 /* The following is screwed up shit to deal with the fact that
61 the linux kernel edits the packet inline. */
62 #define AARP_REQUEST_SWAPPED 0x0100
63 #define AARP_REPLY_SWAPPED 0x0200
64 #define AARP_PROBE_SWAPPED 0x0300
66 static const value_string op_vals[] = {
67 {AARP_REQUEST, "request" },
68 {AARP_REPLY, "reply" },
69 {AARP_PROBE, "probe" },
70 {AARP_REQUEST_SWAPPED, "request" },
71 {AARP_REPLY_SWAPPED, "reply" },
72 {AARP_PROBE_SWAPPED, "probe" },
75 /* AARP protocol HARDWARE identifiers. */
76 #define AARPHRD_ETHER 1 /* Ethernet 10Mbps */
77 #define AARPHRD_TR 2 /* Token Ring */
79 static const value_string hrd_vals[] = {
80 {AARPHRD_ETHER, "Ethernet" },
81 {AARPHRD_TR, "Token Ring" },
85 atalkid_to_str(const guint8 *ad) {
87 static gchar str[3][16];
90 if (cur == &str[0][0]) {
92 } else if (cur == &str[1][0]) {
99 sprintf(cur, "%d.%d",node,ad[3]);
104 aarphrdaddr_to_str(guint8 *ad, int ad_len, guint16 type) {
105 if ((type == AARPHRD_ETHER || type == AARPHRD_TR) && ad_len == 6) {
106 /* Ethernet address (or Token Ring address, which is the same type
108 return ether_to_str(ad);
110 return bytes_to_str(ad, ad_len);
114 aarpproaddr_to_str(guint8 *ad, int ad_len, guint16 type) {
115 if (type == ETHERTYPE_ATALK && ad_len == 4) {
117 return atalkid_to_str(ad);
119 return bytes_to_str(ad, ad_len);
122 /* Offsets of fields within an AARP packet. */
128 #define MIN_AARP_HEADER_SIZE 8
131 dissect_aarp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
137 proto_tree *aarp_tree;
140 int sha_offset, spa_offset, tha_offset, tpa_offset;
141 guint8 *sha_val, *spa_val, *tha_val, *tpa_val;
142 gchar *sha_str, *spa_str, *tha_str, *tpa_str;
144 CHECK_DISPLAY_AS_DATA(proto_aarp, tvb, pinfo, tree);
146 pinfo->current_proto = "AARP";
148 ar_hrd = tvb_get_ntohs(tvb, AR_HRD);
149 ar_pro = tvb_get_ntohs(tvb, AR_PRO);
150 ar_hln = tvb_get_guint8(tvb, AR_HLN);
151 ar_pln = tvb_get_guint8(tvb, AR_PLN);
152 ar_op = tvb_get_ntohs(tvb, AR_OP);
154 /* Extract the addresses. */
155 sha_offset = MIN_AARP_HEADER_SIZE;
156 sha_val = tvb_get_ptr(tvb, sha_offset, ar_hln);
157 sha_str = aarphrdaddr_to_str(sha_val, ar_hln, ar_hrd);
159 spa_offset = sha_offset + ar_hln;
160 spa_val = tvb_get_ptr(tvb, spa_offset, ar_pln);
161 spa_str = aarpproaddr_to_str(spa_val, ar_pln, ar_pro);
163 tha_offset = spa_offset + ar_pln;
164 tha_val = tvb_get_ptr(tvb, tha_offset, ar_hln);
165 tha_str = aarphrdaddr_to_str(tha_val, ar_hln, ar_hrd);
167 tpa_offset = tha_offset + ar_hln;
168 tpa_val = tvb_get_ptr(tvb, tpa_offset, ar_pln);
169 tpa_str = aarpproaddr_to_str(tpa_val, ar_pln, ar_pro);
171 if(check_col(pinfo->fd, COL_PROTOCOL))
172 col_set_str(pinfo->fd, COL_PROTOCOL, "AARP");
174 if (check_col(pinfo->fd, COL_INFO)) {
177 case AARP_REQUEST_SWAPPED:
178 col_add_fstr(pinfo->fd, COL_INFO, "Who has %s? Tell %s", tpa_str, spa_str);
181 case AARP_REPLY_SWAPPED:
182 col_add_fstr(pinfo->fd, COL_INFO, "%s is at %s", spa_str, sha_str);
185 case AARP_PROBE_SWAPPED:
186 col_add_fstr(pinfo->fd, COL_INFO, "Is there a %s", tpa_str);
189 col_add_fstr(pinfo->fd, COL_INFO, "Unknown AARP opcode 0x%04x", ar_op);
195 if ((op_str = match_strval(ar_op, op_vals)))
196 ti = proto_tree_add_protocol_format(tree, proto_aarp, tvb, 0,
197 MIN_AARP_HEADER_SIZE + 2*ar_hln +
198 2*ar_pln, "AppleTalk Address Resolution Protocol (%s)", op_str);
200 ti = proto_tree_add_protocol_format(tree, proto_aarp, tvb, 0,
201 MIN_AARP_HEADER_SIZE + 2*ar_hln +
203 "AppleTalk Address Resolution Protocol (opcode 0x%04x)", ar_op);
204 aarp_tree = proto_item_add_subtree(ti, ett_aarp);
205 proto_tree_add_uint(aarp_tree, hf_aarp_hard_type, tvb, AR_HRD, 2,
207 proto_tree_add_uint(aarp_tree, hf_aarp_proto_type, tvb, AR_PRO, 2,
209 proto_tree_add_uint(aarp_tree, hf_aarp_hard_size, tvb, AR_HLN, 1,
211 proto_tree_add_uint(aarp_tree, hf_aarp_proto_size, tvb, AR_PLN, 1,
213 proto_tree_add_uint(aarp_tree, hf_aarp_opcode, tvb, AR_OP, 2,
215 proto_tree_add_bytes_format(aarp_tree, hf_aarp_src_ether, tvb, sha_offset, ar_hln,
217 "Sender hardware address: %s", sha_str);
218 proto_tree_add_bytes_format(aarp_tree, hf_aarp_src_id, tvb, spa_offset, ar_pln,
220 "Sender ID: %s", spa_str);
221 proto_tree_add_bytes_format(aarp_tree, hf_aarp_dst_ether, tvb, tha_offset, ar_hln,
223 "Target hardware address: %s", tha_str);
224 proto_tree_add_bytes_format(aarp_tree, hf_aarp_dst_id, tvb, tpa_offset, ar_pln,
226 "Target ID: %s", tpa_str);
231 proto_register_aarp(void)
233 static hf_register_info hf[] = {
234 { &hf_aarp_hard_type,
235 { "Hardware type", "aarp.hard.type",
236 FT_UINT16, BASE_HEX, VALS(hrd_vals), 0x0,
239 { &hf_aarp_proto_type,
240 { "Protocol type", "aarp.proto.type",
241 FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
244 { &hf_aarp_hard_size,
245 { "Hardware size", "aarp.hard.size",
246 FT_UINT8, BASE_DEC, NULL, 0x0,
249 { &hf_aarp_proto_size,
250 { "Protocol size", "aarp.proto.size",
251 FT_UINT8, BASE_DEC, NULL, 0x0,
255 { "Opcode", "aarp.opcode",
256 FT_UINT16, BASE_DEC, VALS(op_vals), 0x0,
259 { &hf_aarp_src_ether,
260 { "Sender ether", "aarp.src.ether",
261 FT_BYTES, BASE_NONE, NULL, 0x0,
265 { "Sender ID", "aarp.src.id",
266 FT_BYTES, BASE_HEX, NULL, 0x0,
269 { &hf_aarp_dst_ether,
270 { "Target ether", "aarp.dst.ether",
271 FT_BYTES, BASE_NONE, NULL, 0x0,
275 { "Target ID", "aarp.dst.id",
276 FT_BYTES, BASE_HEX, NULL, 0x0,
279 static gint *ett[] = {
283 proto_aarp = proto_register_protocol("Appletalk Address Resolution Protocol",
285 proto_register_field_array(proto_aarp, hf, array_length(hf));
286 proto_register_subtree_array(ett, array_length(ett));
290 proto_reg_handoff_aarp(void)
292 dissector_add("ethertype", ETHERTYPE_AARP, dissect_aarp);