基于python模拟TCP3次握手连接及发送数据
时间：2021-06-15 09:14:53|栏目：Python代码|点击： 次
源码如下
from scapy.all import *
import logging
logging.getLogger('scapy.runtime').setLevel(logging.ERROR)
target_ip = '192.168.1.1'
target_port = 80
data = 'GET / HTTP/1.0 \r\n\r\n'
def start_tcp(target_ip,target_port):
global sport,s_seq,d_seq #主要是用于TCP3此握手建立连接后继续发送数据
try:
#第一次握手，发送SYN包
ans = sr1(IP(dst=target_ip)/TCP(dport=target_port,sport=RandShort(),seq=RandInt(),flags='S'),verbose=False)
sport = ans[TCP].dport #源随机端口
s_seq = ans[TCP].ack #源序列号（其实初始值已经被服务端加1）
d_seq = ans[TCP].seq + 1 #确认号，需要把服务端的序列号加1
#第三次握手，发送ACK确认包
send(IP(dst=target_ip)/TCP(dport=target_port,sport=sport,ack=d_seq,seq=s_seq,flags='A'),verbose=False)
except Exception,e:
print '[-]有错误，请注意检查！'
print e
def trans_data(target_ip,target_port,data):
#先建立TCP连接
start_tcp(target_ip=target_ip,target_port=target_port)
#print sport,s_seq,d_seq
#发起GET请求
ans = sr1(IP(dst=target_ip)/TCP(dport=target_port,sport=sport,seq=s_seq,ack=d_seq,flags=24)/data,verbose=False)
#ans.show()
#读取服务端发来的数据
rcv = ans[Raw]
print rcv
if __name__ == '__main__':
#start_tcp(target_ip,target_port)
trans_data(target_ip,target_port,data)
运行结果如下
# python exp3.py <meta http-equiv="Pragma" content="no-cache"> <meta http-equiv="Expires" content="wed, 26 Feb 1997 08:21:57 GMT"> <html><head><title>505 HTTP Version not supported</title></head><body><center><h1>505 HTTP Version not supported</h1></center></body></html>�p�-1���-1��2��2��D ��o�p�-1��`��D
wireshark抓包截图如下：
