在套接字中重新发送数据

Question

所以我试图一遍又一遍地向我的虚拟机发送多个数据包，但在一次尝试之后，我得到了错误：

Traceback (most recent call last):
  File "SMB_Test2.py", line 157, in <module>
    s.sendall(SMB_COM_NEGOTIATE)
  File "C:\Python27\Lib\socket.py", line 228, in meth
    return getattr(self._sock,name)(*args)
socket.error: [Errno 10054] An existing connection was forcibly closed by the remote host

我认为这是由于重复发送格式错误的数据（故意），但我想知道是否以及如何解决这个问题。我本质上是想多次重复发送 SMB_COM_NEGOTIATE 。提前致谢。

import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((addr, port))
s.settimeout(2)

print '[*] Connected to "%s:%d".' % (addr, port)
s.sendall(SMB_COM_NEGOTIATE)
a = 0
while a != 50000:
    print a
    a = a + 1
    s.sendall(SMB_COM_NEGOTIATE)
    print '[*] Sent to "%s:%d".' % (addr, port)

编辑（根据 Jame 的建议）- 仍然直接跳到错误：

a = 0
try:
    print "The value of 'a' is %r." % a
    s.connect((addr, port))
    print '[*] Connected to "%s:%d".' % (addr, port)
    while a != 50000:
        a = a + 1
        s.sendall(SMB_COM_NEGOTIATE)
        print '[*] Sent to "%s:%d".' % (addr, port)
        print "The value 'a' is %r." % a
except:
    print "[-] An error occured!!!"
    s.close()
    exit()

输出：

The value of 'a' is 0.
[*] Connected to "192.168.xxx.xxx:xxx".
[*] Sent to "192.168.xxx.xxx:xxx".
The value 'a' is 1.
[-] An error occured!!!

也试过这个（几乎相同）：

a = 0
print "The value of 'a' is %r." % a
s.connect((addr, port))
print '[*] Connected to "%s:%d".' % (addr, port)
def ok():
    try:
        while a != 50000:
            a = a + 1
            s.sendall(SMB_COM_NEGOTIATE)
            print '[*] Sent to "%s:%d".' % (addr, port)
            print "The value 'a' is %r." % a
    except:
        print "[-] An error occured!!!"
        sleep(0)
        s.close()

有输出（甚至不发送任何东西）：

The value of 'a' is 0.
[*] Connected to "192.168.xxx.xxx:xxx".
[-] An error occurred!!!

Answer 1

这是一个代码片段来说明我的评论。

import socket

def try_connect():
    """Tries to connect and send the SMB_COM_NEGOTIATE bytes.
       Returns the socket object on success and None on failure.
    """
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(2)
    try:
        s.connect((addr, port))
        s.sendall(SMB_COM_NEGOTIATE)
    except socket.timeout as e:
        # got a socket timeout
        return None
    except OSError as e:
        # got some other socket error
        return None
    return s

def try_connect_n_times(n):
    """Try up to n times to connect"""
    for attempt in range(n):
        s = try_connect()
        if s:
            return s
    return None

try_connect_n_times(5000)