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/* packet-tcp.c
* Routines for TCP packet disassembly
*
* $Id: packet-tcp.c,v 1.3 1998/09/17 03:12:28 gerald Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.org>
* 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 <gtk/gtk.h>
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include "ethereal.h"
#include "packet.h"
extern FILE* data_out_file;
extern packet_info pi;
void
dissect_tcp(const u_char *pd, int offset, frame_data *fd, GtkTree *tree) {
e_tcphdr th;
GtkWidget *tcp_tree, *ti;
gchar flags[64] = "<None>";
gchar *fstr[] = {"FIN", "SYN", "RST", "PSH", "ACK", "URG"};
gint fpos = 0, i;
guint bpos;
/* To do: Check for {cap len,pkt len} < struct len */
/* Avoids alignment problems on many architectures. */
memcpy(&th, &pd[offset], sizeof(e_tcphdr));
th.th_sport = ntohs(th.th_sport);
th.th_dport = ntohs(th.th_dport);
th.th_win = ntohs(th.th_win);
th.th_sum = ntohs(th.th_sum);
th.th_urp = ntohs(th.th_urp);
th.th_seq = ntohl(th.th_seq);
th.th_ack = ntohl(th.th_ack);
for (i = 0; i < 6; i++) {
bpos = 1 << i;
if (th.th_flags & bpos) {
if (fpos) {
strcpy(&flags[fpos], ", ");
fpos += 2;
}
strcpy(&flags[fpos], fstr[i]);
fpos += 3;
}
}
flags[fpos] = '\0';
if (fd->win_info[0]) {
strcpy(fd->win_info[3], "TCP");
sprintf(fd->win_info[4], "Source port: %d Destination port: %d",
th.th_sport, th.th_dport);
}
if (tree) {
ti = add_item_to_tree(GTK_WIDGET(tree), offset, 20,
"Transmission Control Protocol");
tcp_tree = gtk_tree_new();
add_subtree(ti, tcp_tree, ETT_TCP);
add_item_to_tree(tcp_tree, offset, 2, "Source port: %d", th.th_sport);
add_item_to_tree(tcp_tree, offset + 2, 2, "Destination port: %d", th.th_dport);
add_item_to_tree(tcp_tree, offset + 4, 4, "Sequence number: 0x%08x",
th.th_seq);
add_item_to_tree(tcp_tree, offset + 8, 4, "Acknowledgement number: 0x%08x",
th.th_ack);
add_item_to_tree(tcp_tree, offset + 12, 1, "Header length: %d", th.th_off);
add_item_to_tree(tcp_tree, offset + 13, 1, "Flags: %s", flags);
add_item_to_tree(tcp_tree, offset + 14, 2, "Window size: %d", th.th_win);
add_item_to_tree(tcp_tree, offset + 16, 2, "Checksum: 0x%04x", th.th_sum);
add_item_to_tree(tcp_tree, offset + 18, 2, "Urgent pointer: 0x%04x",
th.th_urp);
/* To do: TCP options */
}
/* Skip over header + options */
offset += 4 * th.th_off;
/* until we decode those options, I'll check the packet length
to see if there's more data. -- gilbert */
if (fd->cap_len > offset) {
switch(MIN(th.th_sport, th.th_dport)) {
case TCP_PORT_PRINTER:
dissect_lpd(pd, offset, fd, tree);
break;
default:
dissect_data(pd, offset, fd, tree);
}
}
pi.srcport = th.th_sport;
pi.destport = th.th_dport;
if( data_out_file ) {
reassemble_tcp( th.th_seq, /* sequence number */
( pi.iplen -( pi.iphdrlen * 4 )-( th.th_off * 4 ) ), /* length */
( pd+offset ), /* data */
( th.th_flags & 0x02 ), /* is syn set? */
pi.ip_src ); /* src ip */
}
}
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