+++ /dev/null
-/* follow.c
- *
- * $Id$
- *
- * Copyright 1998 Mike Hall <mlh@io.com>
- *
- * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@ethereal.com>
- * Copyright 1998 Gerald Combs
- *
- * 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 <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-#include <glib.h>
-#include <epan/packet.h>
-#include "follow.h"
-
-#define MAX_IPADDR_LEN 16
-
-typedef struct _tcp_frag {
- gulong seq;
- gulong len;
- gulong data_len;
- gchar *data;
- struct _tcp_frag *next;
-} tcp_frag;
-
-FILE* data_out_file = NULL;
-
-gboolean incomplete_tcp_stream = FALSE;
-
-static guint8 ip_address[2][MAX_IPADDR_LEN];
-static guint tcp_port[2];
-static guint bytes_written[2];
-static gboolean is_ipv6 = FALSE;
-
-static int check_fragments( int, tcp_stream_chunk * );
-static void write_packet_data( int, tcp_stream_chunk *, const char * );
-
-void
-follow_tcp_stats(follow_tcp_stats_t* stats)
-{
- int i;
-
- for (i = 0; i < 2 ; i++) {
- memcpy(stats->ip_address[i], ip_address[i], MAX_IPADDR_LEN);
- stats->tcp_port[i] = tcp_port[i];
- stats->bytes_written[i] = bytes_written[i];
- stats->is_ipv6 = is_ipv6;
- }
-}
-
-/* this will build libpcap filter text that will only
- pass the packets related to the stream. There is a
- chance that two streams could intersect, but not a
- very good one */
-char*
-build_follow_filter( packet_info *pi ) {
- char* buf = g_malloc(1024);
- int len;
- if( pi->net_src.type == AT_IPv4 && pi->net_dst.type == AT_IPv4
- && pi->ipproto == 6 ) {
- /* TCP over IPv4 */
- sprintf( buf,
- "(ip.addr eq %s and ip.addr eq %s) and (tcp.port eq %d and tcp.port eq %d)",
- ip_to_str( pi->net_src.data),
- ip_to_str( pi->net_dst.data),
- pi->srcport, pi->destport );
- len = 4;
- is_ipv6 = FALSE;
- }
- else if( pi->net_src.type == AT_IPv6 && pi->net_dst.type == AT_IPv6
- && pi->ipproto == 6 ) {
- /* TCP over IPv6 */
- sprintf( buf,
- "(ipv6.addr eq %s and ipv6.addr eq %s) and (tcp.port eq %d and tcp.port eq %d)",
- ip6_to_str((const struct e_in6_addr *)pi->net_src.data),
- ip6_to_str((const struct e_in6_addr *)pi->net_dst.data),
- pi->srcport, pi->destport );
- len = 16;
- is_ipv6 = TRUE;
- }
- else {
- g_free( buf );
- return NULL;
- }
- memcpy(ip_address[0], pi->net_src.data, len);
- memcpy(ip_address[1], pi->net_dst.data, len);
- tcp_port[0] = pi->srcport;
- tcp_port[1] = pi->destport;
- return buf;
-}
-
-/* here we are going to try and reconstruct the data portion of a TCP
- session. We will try and handle duplicates, TCP fragments, and out
- of order packets in a smart way. */
-
-static tcp_frag *frags[2] = { 0, 0 };
-static gulong seq[2];
-static guint8 src_addr[2][MAX_IPADDR_LEN];
-static guint src_port[2] = { 0, 0 };
-
-void
-reassemble_tcp( gulong sequence, gulong length, const char* data,
- gulong data_length, int synflag, address *net_src,
- address *net_dst, guint srcport, guint dstport) {
- guint8 srcx[MAX_IPADDR_LEN], dstx[MAX_IPADDR_LEN];
- int src_index, j, first = 0, len;
- gulong newseq;
- tcp_frag *tmp_frag;
- tcp_stream_chunk sc;
-
- src_index = -1;
-
- /* First, check if this packet should be processed. */
-
- if ((net_src->type != AT_IPv4 && net_src->type != AT_IPv6) ||
- (net_dst->type != AT_IPv4 && net_dst->type != AT_IPv6))
- return;
-
- if (net_src->type == AT_IPv4)
- len = 4;
- else
- len = 16;
-
- /* Now check if the packet is for this connection. */
- memcpy(srcx, net_src->data, len);
- memcpy(dstx, net_dst->data, len);
- if (
- ! (
- memcmp(srcx, ip_address[0], len) == 0 &&
- memcmp(dstx, ip_address[1], len) == 0 &&
- srcport == tcp_port[0] &&
- dstport == tcp_port[1]
- ) &&
- ! (
- memcmp(srcx, ip_address[1], len) == 0 &&
- memcmp(dstx, ip_address[0], len) == 0 &&
- srcport == tcp_port[1] &&
- dstport == tcp_port[0]
- )
- )
- return;
-
- /* Initialize our stream chunk. This data gets written to disk. */
- memcpy(sc.src_addr, srcx, len);
- sc.src_port = srcport;
- sc.dlen = data_length;
-
- /* Check to see if we have seen this source IP and port before.
- (Yes, we have to check both source IP and port; the connection
- might be between two different ports on the same machine.) */
- for( j=0; j<2; j++ ) {
- if (memcmp(src_addr[j], srcx, len) == 0 && src_port[j] == srcport ) {
- src_index = j;
- }
- }
- /* we didn't find it if src_index == -1 */
- if( src_index < 0 ) {
- /* assign it to a src_index and get going */
- for( j=0; j<2; j++ ) {
- if( src_port[j] == 0 ) {
- memcpy(src_addr[j], srcx, len);
- src_port[j] = srcport;
- src_index = j;
- first = 1;
- break;
- }
- }
- }
- if( src_index < 0 ) {
- fprintf( stderr, "ERROR in reassemble_tcp: Too many addresses!\n");
- return;
- }
-
- if( data_length < length ) {
- incomplete_tcp_stream = TRUE;
- }
-
- /* now that we have filed away the srcs, lets get the sequence number stuff
- figured out */
- if( first ) {
- /* this is the first time we have seen this src's sequence number */
- seq[src_index] = sequence + length;
- if( synflag ) {
- seq[src_index]++;
- }
- /* write out the packet data */
- write_packet_data( src_index, &sc, data );
- return;
- }
- /* if we are here, we have already seen this src, let's
- try and figure out if this packet is in the right place */
- if( sequence < seq[src_index] ) {
- /* this sequence number seems dated, but
- check the end to make sure it has no more
- info than we have already seen */
- newseq = sequence + length;
- if( newseq > seq[src_index] ) {
- gulong new_len;
-
- /* this one has more than we have seen. let's get the
- payload that we have not seen. */
-
- new_len = seq[src_index] - sequence;
-
- if ( data_length <= new_len ) {
- data = NULL;
- data_length = 0;
- incomplete_tcp_stream = TRUE;
- } else {
- data += new_len;
- data_length -= new_len;
- }
- sc.dlen = data_length;
- sequence = seq[src_index];
- length = newseq - seq[src_index];
-
- /* this will now appear to be right on time :) */
- }
- }
- if ( sequence == seq[src_index] ) {
- /* right on time */
- seq[src_index] += length;
- if( synflag ) seq[src_index]++;
- if( data ) {
- write_packet_data( src_index, &sc, data );
- }
- /* done with the packet, see if it caused a fragment to fit */
- while( check_fragments( src_index, &sc ) )
- ;
- }
- else {
- /* out of order packet */
- if(data_length > 0 && sequence > seq[src_index] ) {
- tmp_frag = (tcp_frag *)malloc( sizeof( tcp_frag ) );
- tmp_frag->data = (guchar *)malloc( data_length );
- tmp_frag->seq = sequence;
- tmp_frag->len = length;
- tmp_frag->data_len = data_length;
- memcpy( tmp_frag->data, data, data_length );
- if( frags[src_index] ) {
- tmp_frag->next = frags[src_index];
- } else {
- tmp_frag->next = NULL;
- }
- frags[src_index] = tmp_frag;
- }
- }
-} /* end reassemble_tcp */
-
-/* here we search through all the frag we have collected to see if
- one fits */
-static int
-check_fragments( int index, tcp_stream_chunk *sc ) {
- tcp_frag *prev = NULL;
- tcp_frag *current;
- current = frags[index];
- while( current ) {
- if( current->seq == seq[index] ) {
- /* this fragment fits the stream */
- if( current->data ) {
- sc->dlen = current->data_len;
- write_packet_data( index, sc, current->data );
- }
- seq[index] += current->len;
- if( prev ) {
- prev->next = current->next;
- } else {
- frags[index] = current->next;
- }
- free( current->data );
- free( current );
- return 1;
- }
- prev = current;
- current = current->next;
- }
- return 0;
-}
-
-/* this should always be called before we start to reassemble a stream */
-void
-reset_tcp_reassembly() {
- tcp_frag *current, *next;
- int i;
- incomplete_tcp_stream = FALSE;
- for( i=0; i<2; i++ ) {
- seq[i] = 0;
- memset(src_addr[i], '\0', MAX_IPADDR_LEN);
- src_port[i] = 0;
- memset(ip_address[i], '\0', MAX_IPADDR_LEN);
- tcp_port[i] = 0;
- bytes_written[i] = 0;
- current = frags[i];
- while( current ) {
- next = current->next;
- free( current->data );
- free( current );
- current = next;
- }
- frags[i] = NULL;
- }
-}
-
-static void
-write_packet_data( int index, tcp_stream_chunk *sc, const char *data )
-{
- fwrite( sc, 1, sizeof(tcp_stream_chunk), data_out_file );
- fwrite( data, 1, sc->dlen, data_out_file );
- bytes_written[index] += sc->dlen;
-}
git.samba.org / obnox / wireshark / wip.git / blobdiff