端口扫描器原理很简单,无非就是操作socket,能connect就认定这个端口开放着。
import socket def scan(port): s = socket.socket() if s.connect_ex(('localhost', port)) == 0: print port, 'open' s.close() if __name__ == '__main__': map(scan,range(1,65536))这样一个最简单的端口扫描器出来了。
等等喂,半天都没反应,那是因为socket是阻塞的,每次连接要等很久才超时。
我们自己给它加上的超时。
s.settimeout(0.1)
再跑一遍,感觉快多了。
import socket import threading def scan(port): s = socket.socket() s.settimeout(0.1) if s.connect_ex(('localhost', port)) == 0: print port, 'open' s.close() if __name__ == '__main__': threads = [threading.Thread(target=scan, args=(i,)) for i in xrange(1,65536)] map(lambda x:x.start(),threads)运行一下,哇,好快,快到抛出错误了。thread.error: can't start new thread。
想一下,这个进程开启了65535个线程,有两种可能,一种是超过最大线程数了,一种是超过最大socket句柄数了。在linux可以通过ulimit来修改。
如果不修改最大限制,怎么用多线程不报错呢?
加个queue,变成生产者-消费者模式,开固定线程。
import socket import threading from Queue import Queue def scan(port): s = socket.socket() s.settimeout(0.1) if s.connect_ex(('localhost', port)) == 0: print port, 'open' s.close() def worker(): while not q.empty(): port = q.get() try: scan(port) finally: q.task_done() if __name__ == '__main__': q = Queue() map(q.put,xrange(1,65535)) threads = [threading.Thread(target=worker) for i in xrange(500)] map(lambda x:x.start(),threads) q.join()这里开500个线程,不停的从队列取任务来做。
总不能开65535个进程吧?还是用生产者消费者模式
import multiprocessing def scan(port): s = socket.socket() s.settimeout(0.1) if s.connect_ex(('localhost', port)) == 0: print port, 'open' s.close() def worker(q): while not q.empty(): port = q.get() try: scan(port) finally: q.task_done() if __name__ == '__main__': q = multiprocessing.JoinableQueue() map(q.put,xrange(1,65535)) jobs = [multiprocessing.Process(target=worker, args=(q,)) for i in xrange(100)] map(lambda x:x.start(),jobs)
还有用的是JoinableQueue(),顾名思义就是可以join()的。
from gevent import monkey; monkey.patch_all(); import gevent import socket ... if __name__ == '__main__': threads = [gevent.spawn(scan, i) for i in xrange(1,65536)] gevent.joinall(threads)注意monkey patch必须在被patch的东西之前import,不然会Exception KeyError.比如不能先import threading,再monkey patch.
from gevent import monkey; monkey.patch_all(); import socket from gevent.pool import Pool ... if __name__ == '__main__': pool = Pool(500) pool.map(scan,xrange(1,65536)) pool.join()
import socket from Queue import Queue from concurrent.futures import ThreadPoolExecutor ... if __name__ == '__main__': q = Queue() map(q.put,xrange(1,65536)) with ThreadPoolExecutor(max_workers=500) as executor: for i in range(500): executor.submit(worker,q)