原文鏈接:http://wyb0.com/posts/2019/python-coroutine-fast-port-scan/
0x00 協(xié)程的優(yōu)勢
協(xié)程擁有極高的執(zhí)行效率,因為子程序切換不是線程切換,而是由程序自身控制,因此沒有線程切換的開銷请契。和多線程比青责,線程數(shù)量越多麸塞,協(xié)程的性能優(yōu)勢就越明顯么夫。
不需要多線程的鎖機制,因為只有一個線程无宿,也不存在同時寫變量沖突,在協(xié)程中控制共享資源不加鎖枢里,只需要判斷狀態(tài)就好了孽鸡,所以執(zhí)行效率比多線程高很多
0x01 Python中的協(xié)程
協(xié)程也就是微線程,python 的 generator(生成器) 中的 yield 可以一定程度上實現(xiàn)協(xié)程
在 generator 中栏豺,我們不但可以通過 for 循環(huán)來迭代彬碱,還可以不斷調(diào)用 next() 函數(shù)獲取由 yield 語句返回的下一個值。
但是 Python 的 yield 不但可以返回一個值奥洼,它還可以接收調(diào)用者發(fā)出的參數(shù)巷疼。
0x02 使用 gevent
python 中可以通過 generator 實現(xiàn)協(xié)程,但是不完全灵奖,第三方的 gevent 為 Python 提供了比較完善的協(xié)程支持嚼沿,gevent 可以通過 monkey patch 動態(tài)的修改 Python 自帶的一些標準庫
由于 IO 操作(比如訪問網(wǎng)絡)非常耗時估盘,經(jīng)常使程序處于等待狀態(tài),而 gevent 可以為我們自動切換協(xié)程骡尽,再在適當?shù)臅r候切換回來繼續(xù)執(zhí)行遣妥,這就保證總有 greenlet 在運行,而不是等待 IO
使用 gevent 可以獲得極高的并發(fā)性能攀细,但 gevent 只能在 Unix/Linux 下運行箫踩,在 Windows 下不保證正常安裝和運行
下面 3 個網(wǎng)絡操作是并發(fā)執(zhí)行的,且結(jié)束順序不同谭贪,但只有一個線程
from gevent import monkey; monkey.patch_all()
import requests
import gevent
def get_resp_size(url):
print('GET: %s' % url)
html = requests.get(url).content
print('%d bytes received from %s.' % (len(html), url))
def gevent_test(urls):
job_list = [gevent.spawn(get_resp_size, url) for url in urls]
gevent.joinall(job_list)
urls = [
'https://www.python.org/',
'https://www.yahoo.com/',
'https://github.com/',
]
gevent_test(urls)
0x03 asyncio
在 python 3.4 時引入了 asyncio 這個模塊班套,asyncio 專門被用來實現(xiàn)異步IO操作。
通過使用 <f>yield from</f> 和 asyncio 模塊中的 <f>@asyncio.coroutine</f> 可以實現(xiàn)協(xié)程
對于簡單的迭代器故河,yield from iterable 本質(zhì)上等于 for item in iterable: yield item 的縮寫版
- hello world 示例
@asyncio.coroutine
def hello():
print("Hello world!")
r = yield from asyncio.sleep(1)
print("Hello again!")
- 請求web網(wǎng)頁
import asyncio
@asyncio.coroutine
def wget(host):
print('wget %s...' % host)
connect = asyncio.open_connection(host, 80)
reader, writer = yield from connect
header = 'GET / HTTP/1.0\r\nHost: %s\r\n\r\n' % host
writer.write(header.encode('utf-8'))
yield from writer.drain()
while True:
line = yield from reader.readline()
if line == b'\r\n':
break
print('%s header > %s' % (host, line.decode('utf-8').rstrip()))
# Ignore the body, close the socket
writer.close()
loop = asyncio.get_event_loop()
tasks = [wget(host) for host in ['www.sina.com.cn', 'www.sohu.com', 'www.163.com']]
loop.run_until_complete(asyncio.wait(tasks))
loop.close()
0x04 async/await
在 python 3.5 時引入了 async/await
-
關于asyncio的一些關鍵字的說明
- event_loop
事件循環(huán):程序開啟一個無限循環(huán)吱韭,把一些函數(shù)注冊到事件循環(huán)上,當滿足事件發(fā)生的時候鱼的,調(diào)用相應的協(xié)程函數(shù) - coroutine
協(xié)程對象理盆,指一個使用async關鍵字定義的函數(shù),它的調(diào)用不會立即執(zhí)行函數(shù)凑阶,而是會返回一個協(xié)程對象猿规。協(xié)程對象需要注冊到事件循環(huán),由事件循環(huán)調(diào)用宙橱。 - task
一個協(xié)程對象就是一個原生可以掛起的函數(shù)姨俩,任務則是對協(xié)程進一步封裝,其中包含了任務的各種狀態(tài) - future
代表將來執(zhí)行或沒有執(zhí)行的任務的結(jié)果师郑。它和task沒有本質(zhì)上的區(qū)別 - async/await
async定義一個協(xié)程环葵,await就像生成器里的yield一樣用于掛起阻塞的異步調(diào)用接口。
- event_loop
-
async和await是針對coroutine的新語法宝冕,要使用新的語法张遭,只需要做兩步簡單的替換:
- 把@asyncio.coroutine替換為async;
- 把yield from替換為await地梨。
- hello world 示例
@asyncio.coroutine
def hello():
print("Hello world!")
r = yield from asyncio.sleep(1)
print("Hello again!")
# 改為如下代碼:
async def hello():
print("Hello world!")
r = await asyncio.sleep(1)
print("Hello again!")
- 使用asyncio創(chuàng)建任務運行菊卷,并給task指定callback得到執(zhí)行結(jié)果
import asyncio
async def do_some_work(x):
print("waiting:", x)
return "Done after {}s".format(x)
def callback(future):
result = future.result()
print('callback:',result)
def run1():
loop = asyncio.get_event_loop() # 定義一個事件loop
coroutine = do_some_work(2) # 定義協(xié)程對象,它不能直接運行
# run_unitl_complete() 需要傳入一個 Future 對象
# 若傳入?yún)f(xié)程的話 run_unitl_complete 內(nèi)部會將協(xié)程包裝成一個任務(task)對象
# task 對象是 Future 類的子類宝剖,保存了協(xié)程運行后的狀態(tài)洁闰,用于未來獲取協(xié)程的結(jié)果
result = loop.run_until_complete(coroutine)
print(result)
loop.close()
def run2():
loop = asyncio.get_event_loop() # 定義一個事件loop
coroutine = do_some_work(1) # 定義協(xié)程對象,它不能直接運行
task = loop.create_task(coroutine) # 創(chuàng)建協(xié)程 task
# task = asyncio.ensure_future(coroutine) # 也可以使用 ensure_future() 直接創(chuàng)建 Future 對象
task.add_done_callback(callback) # 回調(diào)函數(shù)万细,獲取task的返回值
loop.run_until_complete(task) # 將task加入到事件循環(huán) loop
loop.close()
- 使用 asyncio 并發(fā)執(zhí)行協(xié)程
異步和并發(fā)與并行并沒有關系扑眉,異步用于表示并發(fā)或并行任務的印象
import asyncio
async def do_some_work(x):
print("waiting:", x)
await asyncio.sleep(x)
return "Done after {}s".format(x)
def callback(future):
print('callback',future.result())
def run1():
# 4s 后結(jié)果同時返回
tasks = [asyncio.ensure_future(do_some_work(x)) for x in [2, 1, 4]]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))
for task in tasks:
result = task.result()
print(result)
loop.close()
def run2():
# 1s、2s、4s 分別返回結(jié)果
tasks = [asyncio.ensure_future(do_some_work(x)) for x in [2,1,4]]
for task in tasks:
task.add_done_callback(callback)
loop = asyncio.get_event_loop()
# wait 返回完成的和未完成的任務
done, pending = loop.run_until_complete(asyncio.wait(tasks))
# results = loop.run_until_complete(asyncio.gather(*tasks))
loop.close()
- 停止協(xié)程
import asyncio
async def do_some_work(x):
print("waiting:", x)
await asyncio.sleep(x)
return "Done after {}s".format(x)
def callback(future):
print('callback',future.result())
def run():
# 1s襟雷、2s刃滓、4s 分別返回結(jié)果
tasks = [asyncio.ensure_future(do_some_work(x)) for x in [2,1,4]]
for task in tasks:
task.add_done_callback(callback)
loop = asyncio.get_event_loop()
try:
loop.run_until_complete(asyncio.wait(tasks))
except KeyboardInterrupt as e:
for task in asyncio.Task.all_tasks():
print(task.cancel())
loop.stop()
# loop stop 之后還需要再次開啟事件循環(huán),最后再 close耸弄,不然還會拋出異常
loop.run_forever()
finally:
loop.close()
0x05 協(xié)程與線程配合使用
import asyncio
import threading
async def do_some_work(x):
print("waiting:", x)
await asyncio.sleep(x)
return "Done after {}s".format(x)
def callback(future):
print('callback',future.result())
def start_loop(loop):
asyncio.set_event_loop(loop)
loop.run_forever() # 和 run_until_complete 作用一樣咧虎,不過這個在協(xié)程運行完后不會停止
def run():
# 在子線程中運行協(xié)程loop
sub_loop = asyncio.new_event_loop()
thread = threading.Thread(target=start_loop, args=(sub_loop,))
thread.start()
# 在主線程給子線程的 loop 添加協(xié)程任務
futures = [asyncio.run_coroutine_threadsafe(do_some_work(x), sub_loop) for x in [2,1,4]]
for future in futures:
future.add_done_callback(callback)
print('test...')
try:
while True:pass
except KeyboardInterrupt as e:
import sys;sys.exit('user aborted!')
finally:
sub_loop.call_soon_threadsafe(sub_loop.stop)
run()
? python3 tmp.py
waiting: 2
test...
waiting: 1
waiting: 4
callback Done after 1s
callback Done after 2s
callback Done after 4s
^Cuser aborted!
0x06 通過協(xié)程實現(xiàn)全端口 tcp 快速掃描
import time
import asyncio
import threading
class PortScan(object):
"""docstring for PortScan"""
def __init__(self, ip_list=["127.0.0.1"], all_ports=False, rate=2000):
super(PortScan, self).__init__()
self.ip_list = ip_list
self.rate = rate
self.all_ports = all_ports
self.open_list = {}
self.common_port = "21,22,23,25,53,69,80,81,82,83,84,85,86,87,88,89,110,111,135,139,143,161,389,443,445,465,513,873,993,995,1080,1099,1158,1433,1521,1533,1863,2049,2100,2181,3128,3306,3307,3308,3389,3690,5000,5432,5900,6379,7001,8000,8001,8002,8003,8004,8005,8006,8007,8008,8009,8010,8011,8012,8013,8014,8015,8016,8017,8018,8019,8020,8021,8022,8023,8024,8025,8026,8027,8028,8029,8030,8031,8032,8033,8034,8035,8036,8037,8038,8039,8040,8041,8042,8043,8044,8045,8046,8047,8048,8049,8050,8051,8052,8053,8054,8055,8056,8057,8058,8059,8060,8061,8062,8063,8064,8065,8066,8067,8068,8069,8070,8071,8072,8073,8074,8075,8076,8077,8078,8079,8080,8081,8082,8083,8084,8085,8086,8087,8088,8089,8090,8888,9000,9080,9090,9200,9300,9418,11211,27017,27018,27019,50060"
async def async_port_check(self, semaphore, ip_port):
async with semaphore:
ip,port = ip_port
conn = asyncio.open_connection(ip, port)
try:
reader, writer = await asyncio.wait_for(conn, timeout=10)
return (ip, port, 'open')
except Exception as e:
# print(e)
return (ip, port, 'close')
def callback(self, future):
ip,port,status = future.result()
if status == "open":
print(ip,port,status)
try:
if ip in self.open_list:
self.open_list[ip].append(port)
else:
self.open_list[ip] = [port]
except Exception as e:
print(e)
else:
pass
def async_tcp_port_scan(self):
ports = [port for port in range(11,65535)] if self.all_ports else self.common_port.split(',')
ip_port_list = [(ip,int(port)) for ip in self.ip_list for port in ports]
sem = asyncio.Semaphore(self.rate) # 限制并發(fā)量
loop = asyncio.get_event_loop()
tasks = list()
for ip_port in ip_port_list:
task = asyncio.ensure_future(self.async_port_check(sem, ip_port))
task.add_done_callback(self.callback)
tasks.append(task)
loop.run_until_complete(asyncio.wait(tasks))
print(self.open_list)
if __name__ == '__main__':
ip_list = ["59.108.35.198"]
now = time.time
start = now()
ps = PortScan(ip_list,True,2000)
ps.async_tcp_port_scan()
print("Time:",now()-start)
? python3 tmp.py
59.108.35.198 22 open
59.108.35.198 80 open
59.108.35.198 8888 open
59.108.35.198 50050 open
{'59.108.35.198': [22, 80, 8888, 50050]}
Time: 49.96410322189331