![Gilbert Ramirez](/assets/img/avatar_default.png)
be initialized in gtk/follow_dlg.c In gtk/follow_dlg.c, declare data_out_file as 'extern'. In tethereal.c, no longer define 'data_out_file', as the storage for it is now in follow.c. svn path=/trunk/; revision=4830
323 lines
8.9 KiB
C
323 lines
8.9 KiB
C
/* follow.c
|
|
*
|
|
* $Id: follow.c,v 1.29 2002/02/28 19:35:08 gram Exp $
|
|
*
|
|
* 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
|
|
|
|
#ifdef HAVE_SYS_TYPES_H
|
|
# include <sys/types.h>
|
|
#endif
|
|
|
|
#include <glib.h>
|
|
#include <epan/packet.h>
|
|
#include "follow.h"
|
|
|
|
FILE* data_out_file = NULL;
|
|
|
|
gboolean incomplete_tcp_stream = FALSE;
|
|
|
|
static guint8 ip_address[2][MAX_IPADDR_LEN];
|
|
static u_int tcp_port[2];
|
|
static u_int 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((struct e_in6_addr *)pi->net_src.data),
|
|
ip6_to_str((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 u_long seq[2];
|
|
static guint8 src_addr[2][MAX_IPADDR_LEN];
|
|
static u_int src_port[2] = { 0, 0 };
|
|
|
|
void
|
|
reassemble_tcp( u_long sequence, u_long length, const char* data,
|
|
u_long data_length, int synflag, address *net_src,
|
|
address *net_dst, u_int srcport, u_int dstport) {
|
|
guint8 srcx[MAX_IPADDR_LEN], dstx[MAX_IPADDR_LEN];
|
|
int src_index, j, first = 0, len;
|
|
u_long 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(srcx, ip_address[1], len) != 0) ||
|
|
(memcmp(dstx, ip_address[0], len) != 0 &&
|
|
memcmp(dstx, ip_address[1], len) != 0) ||
|
|
(srcport != tcp_port[0] && srcport != tcp_port[1]) ||
|
|
(dstport != tcp_port[0] && dstport != tcp_port[1]))
|
|
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] ) {
|
|
u_long 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 = (u_char *)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;
|
|
}
|