/* packet-udp.c
* Routines for UDP packet disassembly
*
- * $Id: packet-udp.c,v 1.18 1999/06/25 07:15:02 guy Exp $
+ * $Id: packet-udp.c,v 1.100 2001/12/10 00:25:40 guy Exp $
*
* Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* Richard Sharpe, 13-Feb-1999, added dispatch table support and
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <glib.h>
#include "packet.h"
#include "resolv.h"
+#include "ipproto.h"
+#include "in_cksum.h"
+#include "prefs.h"
-extern packet_info pi;
+#include "packet-udp.h"
+
+#include "packet-ip.h"
+#include "conversation.h"
+
+static int proto_udp = -1;
+static int hf_udp_srcport = -1;
+static int hf_udp_dstport = -1;
+static int hf_udp_port = -1;
+static int hf_udp_length = -1;
+static int hf_udp_checksum = -1;
+static int hf_udp_checksum_bad = -1;
+
+static gint ett_udp = -1;
+
+/* Place UDP summary in proto tree */
+static gboolean udp_summary_in_tree = TRUE;
/* UDP structs and definitions */
guint16 uh_sum;
} e_udphdr;
-/* UDP Ports -> should go in packet-udp.h */
-
-#define UDP_PORT_DNS 53
-#define UDP_PORT_BOOTPS 67
-#define UDP_PORT_TFTP 69
-#define UDP_PORT_IPX 213
-#define UDP_PORT_NBNS 137
-#define UDP_PORT_NBDGM 138
-#define UDP_PORT_SNMP 161
-#define UDP_PORT_ISAKMP 500
-#define UDP_PORT_RIP 520
-#define UDP_PORT_VINES 573
-
-
-struct hash_struct {
- guint16 proto;
- void (*dissect)(const u_char *, int, frame_data *, proto_tree *);
- struct hash_struct *next;
-};
-
-struct hash_struct *hash_table[256];
-
-/*
- * These routines are for UDP, will be generalized soon: RJS
- *
- * XXX - note that they should probably check the IP address as well as
- * the port number, so that we don't mistakenly identify packets as, say,
- * TFTP, merely because they have a source or destination port number
- * equal to the port being used by a TFTP daemon on some machine other
- * than the one they're going to or from.
- */
-
-struct hash_struct *udp_find_hash_ent(guint16 proto) {
-
- int idx = proto % 256;
- struct hash_struct *hash_ent = hash_table[idx];
-
- while (hash_ent != NULL) {
+static dissector_table_t udp_dissector_table;
+static heur_dissector_list_t heur_subdissector_list;
+static dissector_handle_t data_handle;
- if (hash_ent -> proto == proto)
- return hash_ent;
-
- hash_ent = hash_ent -> next;
-
- }
-
- return NULL;
-
-}
-
-void udp_hash_add(guint16 proto,
- void (*dissect)(const u_char *, int, frame_data *, proto_tree *)) {
+/* Determine if there is a sub-dissector and call it. This has been */
+/* separated into a stand alone routine to other protocol dissectors */
+/* can call to it, ie. socks */
- int idx = proto % 256; /* Simply take the remainder, hope for no collisions */
- struct hash_struct *hash_ent = (struct hash_struct *)malloc(sizeof(struct hash_struct));
- struct hash_struct *hash_ent2;
-
- hash_ent -> proto = proto;
- hash_ent -> dissect = dissect;
- hash_ent -> next = NULL;
-
- if (hash_ent == NULL) {
-
- fprintf(stderr, "Could not allocate space for hash structure in dissect_udp\n");
- exit(1);
- }
-
- if (hash_table[idx]) { /* Something, add on end */
-
- hash_ent2 = hash_table[idx];
+void
+decode_udp_ports(tvbuff_t *tvb, int offset, packet_info *pinfo,
+ proto_tree *tree, int uh_sport, int uh_dport)
+{
+ tvbuff_t *next_tvb;
- while (hash_ent2 -> next != NULL)
- hash_ent2 = hash_ent2 -> next;
+ next_tvb = tvb_new_subset(tvb, offset, -1, -1);
- hash_ent2 -> next = hash_ent; /* Bad in pathalogical cases */
+/* determine if this packet is part of a conversation and call dissector */
+/* for the conversation if available */
- }
- else {
+ if (try_conversation_dissector(&pinfo->src, &pinfo->dst, PT_UDP,
+ uh_sport, uh_dport, next_tvb, pinfo, tree))
+ return;
- hash_table[idx] = hash_ent;
+ /* do lookup with the subdissector table */
+ if (dissector_try_port(udp_dissector_table, uh_sport, next_tvb, pinfo, tree) ||
+ dissector_try_port(udp_dissector_table, uh_dport, next_tvb, pinfo, tree))
+ return;
- }
+ /* do lookup with the heuristic subdissector table */
+ if (dissector_try_heuristic(heur_subdissector_list, next_tvb, pinfo, tree))
+ return;
+ call_dissector(data_handle,next_tvb, pinfo, tree);
}
-void init_dissect_udp(void) {
-
- int i;
-
- for (i = 0; i < 256; i++) {
-
- hash_table[i] = NULL;
-
- }
-
- /* Now add the protocols we know about */
-
- udp_hash_add(UDP_PORT_BOOTPS, dissect_bootp);
- udp_hash_add(UDP_PORT_TFTP, dissect_tftp);
-
-}
-void
-dissect_udp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
+static void
+dissect_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
e_udphdr uh;
guint16 uh_sport, uh_dport, uh_ulen, uh_sum;
- struct hash_struct *dissect_routine = NULL;
proto_tree *udp_tree;
proto_item *ti;
- guint payload;
+ guint len;
+ guint reported_len;
+ vec_t cksum_vec[4];
+ guint32 phdr[2];
+ guint16 computed_cksum;
+ int offset = 0;
+
+ if (check_col(pinfo->cinfo, COL_PROTOCOL))
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "UDP");
+ if (check_col(pinfo->cinfo, COL_INFO))
+ col_clear(pinfo->cinfo, COL_INFO);
- /* To do: Check for {cap len,pkt len} < struct len */
/* Avoids alignment problems on many architectures. */
- memcpy(&uh, &pd[offset], sizeof(e_udphdr));
+ tvb_memcpy(tvb, (guint8 *)&uh, offset, sizeof(e_udphdr));
uh_sport = ntohs(uh.uh_sport);
uh_dport = ntohs(uh.uh_dport);
uh_ulen = ntohs(uh.uh_ulen);
uh_sum = ntohs(uh.uh_sum);
- payload = pi.payload - sizeof(e_udphdr);
-
- if (check_col(fd, COL_PROTOCOL))
- col_add_str(fd, COL_PROTOCOL, "UDP");
- if (check_col(fd, COL_INFO))
- col_add_fstr(fd, COL_INFO, "Source port: %s Destination port: %s",
+ if (check_col(pinfo->cinfo, COL_INFO))
+ col_add_fstr(pinfo->cinfo, COL_INFO, "Source port: %s Destination port: %s",
get_udp_port(uh_sport), get_udp_port(uh_dport));
- if (check_col(fd, COL_RES_SRC_PORT))
- col_add_str(fd, COL_RES_SRC_PORT, get_udp_port(uh_sport));
- if (check_col(fd, COL_UNRES_SRC_PORT))
- col_add_fstr(fd, COL_UNRES_SRC_PORT, "%u", uh_sport);
- if (check_col(fd, COL_RES_DST_PORT))
- col_add_str(fd, COL_RES_DST_PORT, get_udp_port(uh_dport));
- if (check_col(fd, COL_UNRES_DST_PORT))
- col_add_fstr(fd, COL_UNRES_DST_PORT, "%u", uh_dport);
if (tree) {
- ti = proto_tree_add_item(tree, offset, 8, "User Datagram Protocol");
- udp_tree = proto_tree_new();
- proto_item_add_subtree(ti, udp_tree, ETT_UDP);
- proto_tree_add_item(udp_tree, offset, 2, "Source port: %s (%u)",
- get_udp_port(uh_sport), uh_sport);
- proto_tree_add_item(udp_tree, offset + 2, 2, "Destination port: %s (%u)",
- get_udp_port(uh_dport), uh_dport);
- proto_tree_add_item(udp_tree, offset + 4, 2, "Length: %u", uh_ulen);
- proto_tree_add_item(udp_tree, offset + 6, 2, "Checksum: 0x%04x", uh_sum);
+ if (udp_summary_in_tree) {
+ ti = proto_tree_add_protocol_format(tree, proto_udp, tvb, offset, 8,
+ "User Datagram Protocol, Src Port: %s (%u), Dst Port: %s (%u)",
+ get_udp_port(uh_sport), uh_sport, get_udp_port(uh_dport), uh_dport);
+ } else {
+ ti = proto_tree_add_item(tree, proto_udp, tvb, offset, 8, FALSE);
+ }
+ udp_tree = proto_item_add_subtree(ti, ett_udp);
+
+ proto_tree_add_uint_format(udp_tree, hf_udp_srcport, tvb, offset, 2, uh_sport,
+ "Source port: %s (%u)", get_udp_port(uh_sport), uh_sport);
+ proto_tree_add_uint_format(udp_tree, hf_udp_dstport, tvb, offset + 2, 2, uh_dport,
+ "Destination port: %s (%u)", get_udp_port(uh_dport), uh_dport);
+
+ proto_tree_add_uint_hidden(udp_tree, hf_udp_port, tvb, offset, 2, uh_sport);
+ proto_tree_add_uint_hidden(udp_tree, hf_udp_port, tvb, offset+2, 2, uh_dport);
+
+ proto_tree_add_uint(udp_tree, hf_udp_length, tvb, offset + 4, 2, uh_ulen);
+ reported_len = tvb_reported_length(tvb);
+ len = tvb_length(tvb);
+ if (uh_sum == 0) {
+ /* No checksum supplied in the packet. */
+ proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
+ offset + 6, 2, uh_sum, "Checksum: 0x%04x (none)", uh_sum);
+ } else if (!pinfo->fragmented && len >= reported_len && len >= uh_ulen) {
+ /* The packet isn't part of a fragmented datagram and isn't
+ truncated, so we can checksum it.
+ XXX - make a bigger scatter-gather list once we do fragment
+ reassembly? */
+
+ /* Set up the fields of the pseudo-header. */
+ cksum_vec[0].ptr = pinfo->src.data;
+ cksum_vec[0].len = pinfo->src.len;
+ cksum_vec[1].ptr = pinfo->dst.data;
+ cksum_vec[1].len = pinfo->dst.len;
+ cksum_vec[2].ptr = (const guint8 *)&phdr;
+ switch (pinfo->src.type) {
+
+ case AT_IPv4:
+ phdr[0] = htonl((IP_PROTO_UDP<<16) + reported_len);
+ cksum_vec[2].len = 4;
+ break;
+
+ case AT_IPv6:
+ phdr[0] = htonl(reported_len);
+ phdr[1] = htonl(IP_PROTO_UDP);
+ cksum_vec[2].len = 8;
+ break;
+
+ default:
+ /* TCP runs only atop IPv4 and IPv6.... */
+ g_assert_not_reached();
+ break;
+ }
+ cksum_vec[3].ptr = tvb_get_ptr(tvb, offset, len);
+ cksum_vec[3].len = reported_len;
+ computed_cksum = in_cksum(&cksum_vec[0], 4);
+ if (computed_cksum == 0) {
+ proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
+ offset + 6, 2, uh_sum, "Checksum: 0x%04x (correct)", uh_sum);
+ } else {
+ proto_tree_add_boolean_hidden(udp_tree, hf_udp_checksum_bad, tvb,
+ offset + 6, 2, TRUE);
+ proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
+ offset + 6, 2, uh_sum,
+ "Checksum: 0x%04x (incorrect, should be 0x%04x)", uh_sum,
+ in_cksum_shouldbe(uh_sum, computed_cksum));
+ }
+ } else {
+ proto_tree_add_uint_format(udp_tree, hf_udp_checksum, tvb,
+ offset + 6, 2, uh_sum, "Checksum: 0x%04x", uh_sum);
+ }
}
/* Skip over header */
offset += 8;
- /* XXX - we should do all of this through the table of ports. */
-#define PORT_IS(port) (uh_sport == port || uh_dport == port)
- if (PORT_IS(UDP_PORT_BOOTPS))
- dissect_bootp(pd, offset, fd, tree);
- else if (PORT_IS(UDP_PORT_DNS))
- dissect_dns(pd, offset, fd, tree);
- else if (PORT_IS(UDP_PORT_ISAKMP))
- dissect_isakmp(pd, offset, fd, tree);
- else if (PORT_IS(UDP_PORT_RIP)) {
- /* we should check the source port too (RIP: UDP src and dst port 520) */
- dissect_rip(pd, offset, fd, tree);
- } else if (PORT_IS(UDP_PORT_NBNS))
- dissect_nbns(pd, offset, fd, tree);
- else if (PORT_IS(UDP_PORT_NBDGM))
- dissect_nbdgm(pd, offset, fd, tree, payload);
- else if (PORT_IS(UDP_PORT_IPX)) /* RFC 1234 */
- dissect_ipx(pd, offset, fd, tree);
-#if defined(HAVE_UCD_SNMP_SNMP_H) || defined(HAVE_SNMP_SNMP_H)
- else if (PORT_IS(UDP_PORT_SNMP))
- dissect_snmp(pd, offset, fd, tree);
-#endif
- else if (PORT_IS(UDP_PORT_VINES)) {
- /* FIXME: AFAIK, src and dst port must be the same */
- dissect_vines_frp(pd, offset, fd, tree);
- } else if (PORT_IS(UDP_PORT_TFTP)) {
- /* This is the first point of call, but it adds a dynamic call */
- udp_hash_add(MAX(uh_sport, uh_dport), dissect_tftp); /* Add to table */
- dissect_tftp(pd, offset, fd, tree);
- } else {
- /* OK, find a routine in the table, else use the default */
-
- if ((dissect_routine = udp_find_hash_ent(uh_sport))) {
-
- struct hash_struct *dr2 = udp_find_hash_ent(uh_dport);
+ pinfo->ptype = PT_UDP;
+ pinfo->srcport = uh_sport;
+ pinfo->destport = uh_dport;
- if (dr2 == NULL) { /* Not in the table, add */
+/* call sub-dissectors */
+ decode_udp_ports( tvb, offset, pinfo, tree, uh_sport, uh_dport);
- udp_hash_add(uh_dport, dissect_tftp);
-
- }
-
- dissect_routine -> dissect(pd, offset, fd, tree);
- }
- else if ((dissect_routine = udp_find_hash_ent(uh_dport))) {
+}
- dissect_routine -> dissect(pd, offset, fd, tree);
+void
+proto_register_udp(void)
+{
+ module_t *udp_module;
+ static hf_register_info hf[] = {
+ { &hf_udp_srcport,
+ { "Source Port", "udp.srcport", FT_UINT16, BASE_DEC, NULL, 0x0,
+ "", HFILL }},
+
+ { &hf_udp_dstport,
+ { "Destination Port", "udp.dstport", FT_UINT16, BASE_DEC, NULL, 0x0,
+ "", HFILL }},
+
+ { &hf_udp_port,
+ { "Source or Destination Port", "udp.port", FT_UINT16, BASE_DEC, NULL, 0x0,
+ "", HFILL }},
+
+ { &hf_udp_length,
+ { "Length", "udp.length", FT_UINT16, BASE_DEC, NULL, 0x0,
+ "", HFILL }},
+
+ { &hf_udp_checksum_bad,
+ { "Bad Checksum", "udp.checksum_bad", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+ "", HFILL }},
+
+ { &hf_udp_checksum,
+ { "Checksum", "udp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
+ "", HFILL }},
+ };
+ static gint *ett[] = {
+ &ett_udp,
+ };
+
+ proto_udp = proto_register_protocol("User Datagram Protocol",
+ "UDP", "udp");
+ proto_register_field_array(proto_udp, hf, array_length(hf));
+ proto_register_subtree_array(ett, array_length(ett));
+
+/* subdissector code */
+ udp_dissector_table = register_dissector_table("udp.port",
+ "UDP port", FT_UINT16, BASE_DEC);
+ register_heur_dissector_list("udp", &heur_subdissector_list);
+
+ /* Register configuration preferences */
+ udp_module = prefs_register_protocol(proto_udp, NULL);
+ prefs_register_bool_preference(udp_module, "udp_summary_in_tree",
+ "Show UDP summary in protocol treee",
+ "Whether the UDP summary line should be shown in the protocol tree",
+ &udp_summary_in_tree);
+}
- }
- else {
+void
+proto_reg_handoff_udp(void)
+{
+ dissector_handle_t udp_handle;
- dissect_data(pd, offset, fd, tree);
- }
- }
+ udp_handle = create_dissector_handle(dissect_udp, proto_udp);
+ dissector_add("ip.proto", IP_PROTO_UDP, udp_handle);
+ data_handle = find_dissector("data");
}
git.samba.org / obnox / wireshark / wip.git / blobdiff