forked from osmocom/wireshark
378 lines
11 KiB
C
378 lines
11 KiB
C
/* packet-udp.c
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* Routines for UDP packet disassembly
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*
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* $Id: packet-udp.c,v 1.47 2000/02/01 04:13:47 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998 Gerald Combs
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*
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* Richard Sharpe, 13-Feb-1999, added dispatch table support and
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* support for tftp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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# include <netinet/in.h>
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <glib.h>
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#include "globals.h"
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#include "resolv.h"
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#include "plugins.h"
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static int proto_udp = -1;
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static int hf_udp_srcport = -1;
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static int hf_udp_dstport = -1;
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static int hf_udp_port = -1;
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static int hf_udp_length = -1;
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static int hf_udp_checksum = -1;
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static gint ett_udp = -1;
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/* UDP structs and definitions */
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typedef struct _e_udphdr {
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guint16 uh_sport;
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guint16 uh_dport;
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guint16 uh_ulen;
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guint16 uh_sum;
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} e_udphdr;
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/* UDP Ports -> should go in packet-udp.h */
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#define UDP_PORT_TACACS 49
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#define UDP_PORT_DNS 53
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#define UDP_PORT_BOOTPS 67
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#define UDP_PORT_TFTP 69
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#define UDP_PORT_IPX 213
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#define UDP_PORT_NTP 123
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#define UDP_PORT_NBNS 137
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#define UDP_PORT_NBDGM 138
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#define UDP_PORT_SNMP 161
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#define UDP_PORT_SNMP_TRAP 162
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#define UDP_PORT_SRVLOC 427
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#define UDP_PORT_PIM_RP_DISC 496
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#define UDP_PORT_ISAKMP 500
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#define UDP_PORT_WHO 513
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#define UDP_PORT_RIP 520
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#define UDP_PORT_RIPNG 521
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#define UDP_PORT_NCP 524
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#define UDP_PORT_VINES 573
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#define UDP_PORT_RADIUS 1645
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#define UDP_PORT_L2TP 1701
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#define UDP_PORT_RADIUS_NEW 1812
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#define UDP_PORT_RADACCT 1646
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#define UDP_PORT_RADACCT_NEW 1813
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#define UDP_PORT_HSRP 1985
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#define UDP_PORT_ICP 3130
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#define UDP_PORT_ICQ 4000
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#define UDP_PORT_SAP 9875
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#define UDP_PORT_RX_LOW 7000
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#define UDP_PORT_RX_HIGH 7009
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#define UDP_PORT_RX_AFS_BACKUPS 7021
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#define UDP_PORT_WCCP 2048
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struct hash_struct {
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guint16 proto;
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void (*dissect)(const u_char *, int, frame_data *, proto_tree *);
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struct hash_struct *next;
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};
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static struct hash_struct *hash_table[256];
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/*
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* These routines are for UDP, will be generalized soon: RJS
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*
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* XXX - note that they should probably check the IP address as well as
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* the port number, so that we don't mistakenly identify packets as, say,
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* TFTP, merely because they have a source or destination port number
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* equal to the port being used by a TFTP daemon on some machine other
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* than the one they're going to or from.
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*/
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struct hash_struct *udp_find_hash_ent(guint16 proto) {
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int idx = proto % 256;
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struct hash_struct *hash_ent = hash_table[idx];
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while (hash_ent != NULL) {
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if (hash_ent -> proto == proto)
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return hash_ent;
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hash_ent = hash_ent -> next;
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}
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return NULL;
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}
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void udp_hash_add(guint16 proto,
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void (*dissect)(const u_char *, int, frame_data *, proto_tree *)) {
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int idx = proto % 256; /* Simply take the remainder, hope for no collisions */
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struct hash_struct *hash_ent = (struct hash_struct *)malloc(sizeof(struct hash_struct));
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struct hash_struct *hash_ent2;
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hash_ent -> proto = proto;
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hash_ent -> dissect = dissect;
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hash_ent -> next = NULL;
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if (hash_ent == NULL) {
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fprintf(stderr, "Could not allocate space for hash structure in dissect_udp\n");
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exit(1);
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}
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if (hash_table[idx]) { /* Something, add on end */
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hash_ent2 = hash_table[idx];
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while (hash_ent2 -> next != NULL)
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hash_ent2 = hash_ent2 -> next;
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hash_ent2 -> next = hash_ent; /* Bad in pathalogical cases */
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}
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else {
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hash_table[idx] = hash_ent;
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}
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}
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void init_dissect_udp(void) {
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int i;
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for (i = 0; i < 256; i++) {
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hash_table[i] = NULL;
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}
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/* Now add the protocols we know about */
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udp_hash_add(UDP_PORT_BOOTPS, dissect_bootp);
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udp_hash_add(UDP_PORT_TFTP, dissect_tftp);
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udp_hash_add(UDP_PORT_SAP, dissect_sap);
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udp_hash_add(UDP_PORT_HSRP, dissect_hsrp);
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udp_hash_add(UDP_PORT_PIM_RP_DISC, dissect_auto_rp);
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udp_hash_add(UDP_PORT_TACACS, dissect_tacacs);
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}
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void
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dissect_udp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
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e_udphdr uh;
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guint16 uh_sport, uh_dport, uh_ulen, uh_sum;
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struct hash_struct *dissect_routine = NULL;
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proto_tree *udp_tree;
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proto_item *ti;
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if (!BYTES_ARE_IN_FRAME(offset, sizeof(e_udphdr))) {
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dissect_data(pd, offset, fd, tree);
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return;
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}
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/* Avoids alignment problems on many architectures. */
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memcpy(&uh, &pd[offset], sizeof(e_udphdr));
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uh_sport = ntohs(uh.uh_sport);
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uh_dport = ntohs(uh.uh_dport);
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uh_ulen = ntohs(uh.uh_ulen);
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uh_sum = ntohs(uh.uh_sum);
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if (check_col(fd, COL_PROTOCOL))
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col_add_str(fd, COL_PROTOCOL, "UDP");
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if (check_col(fd, COL_INFO))
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col_add_fstr(fd, COL_INFO, "Source port: %s Destination port: %s",
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get_udp_port(uh_sport), get_udp_port(uh_dport));
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if (tree) {
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ti = proto_tree_add_item(tree, proto_udp, offset, 8);
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udp_tree = proto_item_add_subtree(ti, ett_udp);
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proto_tree_add_item_format(udp_tree, hf_udp_srcport, offset, 2, uh_sport,
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"Source port: %s (%u)", get_udp_port(uh_sport), uh_sport);
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proto_tree_add_item_format(udp_tree, hf_udp_dstport, offset + 2, 2, uh_dport,
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"Destination port: %s (%u)", get_udp_port(uh_dport), uh_dport);
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proto_tree_add_item_hidden(udp_tree, hf_udp_port, offset, 2, uh_sport);
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proto_tree_add_item_hidden(udp_tree, hf_udp_port, offset+2, 2, uh_dport);
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proto_tree_add_item(udp_tree, hf_udp_length, offset + 4, 2, uh_ulen);
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proto_tree_add_item_format(udp_tree, hf_udp_checksum, offset + 6, 2, uh_sum,
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"Checksum: 0x%04x", uh_sum);
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}
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/* Skip over header */
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offset += 8;
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pi.ptype = PT_UDP;
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pi.srcport = uh_sport;
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pi.destport = uh_dport;
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/* ONC RPC. We can't base this on anything in the UDP header; we have
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to look at the payload. If "dissect_rpc()" returns TRUE, it was
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an RPC packet, otherwise it's some other type of packet. */
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if (dissect_rpc(pd, offset, fd, tree))
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return;
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/* try to apply the plugins */
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#ifdef HAVE_PLUGINS
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{
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plugin *pt_plug = plugin_list;
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if (pt_plug) {
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while (pt_plug) {
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if (pt_plug->enabled && !strcmp(pt_plug->protocol, "udp") &&
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tree && dfilter_apply(pt_plug->filter, tree, pd)) {
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pt_plug->dissector(pd, offset, fd, tree);
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return;
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}
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pt_plug = pt_plug->next;
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}
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}
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}
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#endif
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/* XXX - we should do all of this through the table of ports. */
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#define PORT_IS(port) (uh_sport == port || uh_dport == port)
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if (PORT_IS(UDP_PORT_BOOTPS))
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dissect_bootp(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_DNS))
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dissect_dns(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_SRVLOC))
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dissect_srvloc(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_ISAKMP))
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dissect_isakmp(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_RIP)) {
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/* we should check the source port too (RIP: UDP src and dst port 520) */
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dissect_rip(pd, offset, fd, tree);
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} else if (PORT_IS(UDP_PORT_RIPNG))
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dissect_ripng(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_NCP))
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dissect_ncp(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_NBNS))
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dissect_nbns(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_NBDGM))
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dissect_nbdgm(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_NTP))
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dissect_ntp(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_WHO))
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dissect_who(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_IPX)) /* RFC 1234 */
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dissect_ipx(pd, offset, fd, tree);
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else if ((uh_sport >= UDP_PORT_RX_LOW && uh_sport <= UDP_PORT_RX_HIGH) ||
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(uh_dport >= UDP_PORT_RX_LOW && uh_dport <= UDP_PORT_RX_HIGH) ||
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PORT_IS(UDP_PORT_RX_AFS_BACKUPS))
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dissect_rx(pd, offset, fd, tree); /* transarc AFS's RX protocol */
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else if (PORT_IS(UDP_PORT_SNMP) || PORT_IS(UDP_PORT_SNMP_TRAP))
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dissect_snmp(pd, offset, fd, tree);
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else if (PORT_IS(UDP_PORT_VINES)) {
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/* FIXME: AFAIK, src and dst port must be the same */
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dissect_vines_frp(pd, offset, fd, tree);
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} else if (PORT_IS(UDP_PORT_TFTP)) {
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/* This is the first point of call, but it adds a dynamic call */
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udp_hash_add(MAX(uh_sport, uh_dport), dissect_tftp); /* Add to table */
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dissect_tftp(pd, offset, fd, tree);
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} else if (PORT_IS(UDP_PORT_RADIUS) ||
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PORT_IS(UDP_PORT_RADACCT) ||
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PORT_IS(UDP_PORT_RADIUS_NEW) ||
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PORT_IS(UDP_PORT_RADACCT_NEW) ) {
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dissect_radius(pd, offset, fd, tree);
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} else if ( PORT_IS(UDP_PORT_L2TP)) {
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dissect_l2tp(pd,offset,fd,tree);
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} else if ( PORT_IS(UDP_PORT_ICP)) {
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dissect_icp(pd,offset,fd,tree);
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} else if ( PORT_IS(UDP_PORT_ICQ)) {
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dissect_icq(pd,offset,fd,tree);
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} else if (PORT_IS(UDP_PORT_WCCP) ) {
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dissect_wccp(pd, offset, fd, tree);
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} else {
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/* OK, find a routine in the table, else use the default */
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if ((dissect_routine = udp_find_hash_ent(uh_sport))) {
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struct hash_struct *dr2 = udp_find_hash_ent(uh_dport);
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if (dr2 == NULL) { /* Not in the table, add */
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udp_hash_add(uh_dport, dissect_tftp);
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}
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dissect_routine -> dissect(pd, offset, fd, tree);
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}
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else if ((dissect_routine = udp_find_hash_ent(uh_dport))) {
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dissect_routine -> dissect(pd, offset, fd, tree);
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}
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else {
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dissect_data(pd, offset, fd, tree);
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}
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}
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}
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void
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proto_register_udp(void)
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{
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static hf_register_info hf[] = {
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{ &hf_udp_srcport,
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{ "Source Port", "udp.srcport", FT_UINT16, BASE_DEC, NULL, 0x0,
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"" }},
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{ &hf_udp_dstport,
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{ "Destination Port", "udp.dstport", FT_UINT16, BASE_DEC, NULL, 0x0,
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"" }},
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{ &hf_udp_port,
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{ "Source or Destination Port", "udp.port", FT_UINT16, BASE_DEC, NULL, 0x0,
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"" }},
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{ &hf_udp_length,
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{ "Length", "udp.length", FT_UINT16, BASE_DEC, NULL, 0x0,
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"" }},
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{ &hf_udp_checksum,
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{ "Checksum", "udp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
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"" }},
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};
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static gint *ett[] = {
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&ett_udp,
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};
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proto_udp = proto_register_protocol("User Datagram Protocol", "udp");
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proto_register_field_array(proto_udp, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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