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/*
* $smu-mark$
* $name: sendtcp.c$
* $author: Salvatore Sanfilippo <antirez@invece.org>$
* $copyright: Copyright (C) 1999 by Salvatore Sanfilippo$
* $license: This software is under GPL version 2 of license$
* $date: Fri Nov 5 11:55:49 MET 1999$
* $rev: 8$
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <time.h>
#include "hping2.h"
#include "globals.h"
void send_tcp(void)
{
int packet_size;
int tcp_opt_size = 0;
char *packet, *data;
struct mytcphdr *tcp;
struct pseudohdr *pseudoheader;
unsigned char *tstamp;
if (opt_tcp_timestamp)
tcp_opt_size = 12;
packet_size = TCPHDR_SIZE + tcp_opt_size + data_size;
packet = malloc(PSEUDOHDR_SIZE + packet_size);
if (packet == NULL) {
perror("[send_tcphdr] malloc()");
return;
}
pseudoheader = (struct pseudohdr*) packet;
tcp = (struct mytcphdr*) (packet+PSEUDOHDR_SIZE);
tstamp = (unsigned char*) (packet+PSEUDOHDR_SIZE+TCPHDR_SIZE);
data = (char*) (packet+PSEUDOHDR_SIZE+TCPHDR_SIZE+tcp_opt_size);
memset(packet, 0, PSEUDOHDR_SIZE+packet_size);
/* tcp pseudo header */
memcpy(&pseudoheader->saddr, &local.sin_addr.s_addr, 4);
memcpy(&pseudoheader->daddr, &remote.sin_addr.s_addr, 4);
pseudoheader->protocol = 6; /* tcp */
pseudoheader->lenght = htons(TCPHDR_SIZE+tcp_opt_size+data_size);
/* tcp header */
tcp->th_dport = htons(dst_port);
tcp->th_sport = htons(src_port);
/* sequence number and ack are random if not set */
tcp->th_seq = (set_seqnum) ? htonl(tcp_seqnum) : htonl(rand());
tcp->th_ack = (set_ack) ? htonl(tcp_ack) : htonl(rand());
tcp->th_off = src_thoff + (tcp_opt_size >> 2);
tcp->th_win = htons(src_winsize);
tcp->th_flags = tcp_th_flags;
/* tcp timestamp option */
if (opt_tcp_timestamp) {
__u32 randts = rand() ^ (rand() << 16);
tstamp[0] = tstamp[1] = 1; /* NOOP */
tstamp[2] = 8;
tstamp[3] = 10; /* 10 bytes, kind+len+T1+T2 */
memcpy(tstamp+4, &randts, 4); /* random */
memset(tstamp+8, 0, 4); /* zero */
}
/* data */
data_handler(data, data_size);
/* compute checksum */
#ifdef STUPID_SOLARIS_CHECKSUM_BUG
tcp->th_sum = packet_size;
#else
tcp->th_sum = cksum((u_short*) packet, PSEUDOHDR_SIZE +
packet_size);
#endif
/* adds this pkt in delaytable */
delaytable_add(sequence, src_port, time(NULL), get_usec(), S_SENT);
/* send packet */
send_ip_handler(packet+PSEUDOHDR_SIZE, packet_size);
free(packet);
sequence++; /* next sequence number */
if (!opt_keepstill)
src_port = (sequence + initsport) % 65536;
if (opt_force_incdport)
dst_port++;
}
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