2 * Routines for UDP packet disassembly
4 * $Id: packet-udp.c,v 1.7 1998/11/17 04:29:07 gerald Exp $
6 * Ethereal - Network traffic analyzer
7 * By Gerald Combs <gerald@zing.org>
8 * Copyright 1998 Gerald Combs
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
34 #ifdef HAVE_SYS_TYPES_H
35 # include <sys/types.h>
38 #ifdef HAVE_NETINET_IN_H
39 # include <netinet/in.h>
47 dissect_udp(const u_char *pd, int offset, frame_data *fd, GtkTree *tree) {
49 guint16 uh_sport, uh_dport, uh_ulen, uh_sum;
50 GtkWidget *udp_tree, *ti;
52 /* To do: Check for {cap len,pkt len} < struct len */
53 /* Avoids alignment problems on many architectures. */
54 memcpy(&uh, &pd[offset], sizeof(e_udphdr));
55 uh_sport = ntohs(uh.uh_sport);
56 uh_dport = ntohs(uh.uh_dport);
57 uh_ulen = ntohs(uh.uh_ulen);
58 uh_sum = ntohs(uh.uh_sum);
60 if (check_col(fd, COL_PROTOCOL))
61 col_add_str(fd, COL_PROTOCOL, "UDP");
62 if (check_col(fd, COL_INFO))
63 col_add_fstr(fd, COL_INFO, "Source port: %s Destination port: %s",
64 get_udp_port(uh_sport), get_udp_port(uh_dport));
67 ti = add_item_to_tree(GTK_WIDGET(tree), offset, 8,
68 "User Datagram Protocol");
69 udp_tree = gtk_tree_new();
70 add_subtree(ti, udp_tree, ETT_UDP);
71 add_item_to_tree(udp_tree, offset, 2, "Source port: %s", get_udp_port(uh_sport));
72 add_item_to_tree(udp_tree, offset + 2, 2, "Destination port: %s", get_udp_port(uh_dport));
73 add_item_to_tree(udp_tree, offset + 4, 2, "Length: %d", uh_ulen);
74 add_item_to_tree(udp_tree, offset + 6, 2, "Checksum: 0x%04x", uh_sum);
77 /* Skip over header */
80 /* To do: make sure we aren't screwing ourselves with the MIN call. */
81 switch (MIN(uh_sport, uh_dport)) {
83 dissect_bootp(pd, offset, fd, tree);
86 dissect_dns(pd, offset, fd, tree);
89 /* we should check the source port too (RIP: UDP src and dst port 520) */
90 dissect_rip(pd, offset, fd, tree);
93 dissect_nbns(pd, offset, fd, tree);
95 case UDP_PORT_IPX: /* RFC 1234 */
96 dissect_ipx(pd, offset, fd, tree);
99 dissect_data(pd, offset, fd, tree);