0903编写ssh实现远程执行命令 并解决粘包问题

粘包问题的来源:

　　粘包问题的根源源于tcp协议是一种流的协议,在使用该协议进行通信时会应为tcp流的形式而没能分辨什么是每一个文件,从而会使文件粘在一起,这就是粘包问题
解决粘包问题的思路:

　　在接收每一包是自设定报头,从而区分每一个文件,并且在接收文件时将每一个文件都接收干净

　　用代码实现ssh远程执行命令,并且解决粘包问题

服务端代码:

from socket import *
import subprocess
import struct
import json

phone = socket(AF_INET , SOCK_STREAM)
phone.bind(('127.0.0.1',8081))
phone.listen(5)

while True:
    conn,adr = phone.accept()
    while True:
        try:
            msg = conn.recv(1024).decode('utf-8')
            res = subprocess.Popen(msg,shell=True,stdout=subprocess.PIPE,stderr=subprocess.PIPE)
            stdout = res.stdout.read()
            stderr = res.stderr.read()

            header_dic = {
                'file_name':'a.txt',
                'md5':'adsfaf',
                'total_size':len(stdout)+len(stderr)
            }

            header_dic_json = json.dumps(header_dic)
            header_dic_b = header_dic_json.encode('utf-8')

            header = struct.pack('i',len(header_dic_b))

            conn.send(header)
            conn.send(header_dic_b)
            conn.send(stdout)
            conn.send(stderr)
        except Exception:
            break
    conn.close()

客户端代码:

import struct
from socket import *
import json

phone = socket(AF_INET,SOCK_STREAM)

phone.connect(('127.0.0.1',8081))

while True:
    msg = input('>>>>>:').strip()
    if not msg :
        continue
    if msg == 'q':
        break
    phone.send(msg.encode('utf-8'))
    header = phone.recv(4)
    header_dic_l = struct.unpack('i',header)[0]
    header_dic_json = phone.recv(header_dic_l).decode('utf-8')
    header_dic = json.loads(header_dic_json)
    total_size = header_dic['total_size']
    recv_size = 0
    total_msg = b''
    while recv_size < total_size:
        msg = phone.recv(1024)
        recv_size +=len(msg)
        total_msg +=msg
    print(total_msg.decode('gbk'))

phone.close()