UDP.rar_UDP socket_UDP文件_nsp upd_python udp_文件传输系统

# -*- coding:utf-8 -*- import os import random import socket import struct import _thread import sys # 长度限制常量 FILEPATH_MAX_LEN = 256 # 文件路径最大长度 BLOCK_MAX_SIZE = 1464 # 数据报中所能包含的最大分片数据长度 DGRAM_MAX_SIZE = 1472 # 数据报载荷的最大长度 DGRAM_MIN_SIZE = 5 # 数据报载荷的最小长度 # 超时和重传常量 SHACKHANDS_TIMEOUT = 5 # 握手阶段超时时间 DATA_TRAN_TIMEOUT = 2 # 数据传输阶段超时时间 DATA_TRAN_RESEND = 5 # 数据传输阶段超时重传次数 SERVER_TIMEOUT = 30 # 服务端超时时间 # 数据报类型 SHACKHANDS_MSG = 0x00 SHACKHANDS_ACK_MSG = 0x01 DATA_TRAN_MSG = 0x02 DATA_TRAN_ACK_MSG = 0x03 # 客户端状态 SHAKEHANDS_STATUS = 0 DATA_TRAN_STATUS = 1 # 服务端监听握手请求的端口 SERVER_PORT = 44444 # 隐写类型 TYPE1 = 0x00 # 文件不包含隐写信息 TYPE2 = 0x01 TYPE3 = 0x02 TYPE4 = 0x03 TYPE5 = 0x04 TYPE6 = 0x05 TYPE7 = 0x06 TYPE8 = 0x07 TYPE9 = 0x08 # 客户端 class Client(object): def __init__(self): self.dgram_flag = random.randint(0, 10000) # 数据报标识，初始化时选择随机值 self.status = SHAKEHANDS_STATUS # 客户端状态 self.server_ip = '127.0.0.1' # 服务端ip，默认为本地环回ip self.server_port = SERVER_PORT # 服务端端口 self.server_addr = None # 服务端地址信息 self.sock = None # 客户端套接字 self.filepath = None # 要传输的文件路径 # 服务端 class Server(object): class ClientInfo(object): # 客户端信息 def __init__(self): self.address = None self.dgram_flag = None self.sock = None self.file = None def __init__(self): self.status = SHAKEHANDS_STATUS # 当前所处状态 self.local_ip = sys.argv[1] # 服务端绑定的ip self.local_port = SERVER_PORT # 服务端绑定的监听握手请求的端口 self.local_addr = None # 服务端绑定的地址信息 self.sock = None # 服务端监听握手请求的套接字 # 每次调用从文件中依次读取一个block的数据 def get_file_block(filepath): with open(filepath, 'rb') as f: while True: block = f.read(BLOCK_MAX_SIZE) if block: yield block else: yield None # 构造数据报中的数据载荷 def create_dgram( dgram_flag, dgram_type, filename = None, recv_port = None, split_flag = None, split_index = None, data = None, data_len = None): if dgram_type == SHACKHANDS_MSG: dgram = struct.pack('!HB256s', dgram_flag, SHACKHANDS_MSG, filename.encode('UTF-8')) elif dgram_type == SHACKHANDS_ACK_MSG: dgram = struct.pack('!HBH', dgram_flag, SHACKHANDS_ACK_MSG, recv_port) elif dgram_type == DATA_TRAN_MSG: dgram = struct.pack('!HBBI' + str(data_len) + 's', dgram_flag, DATA_TRAN_MSG, split_flag, split_index, data) elif dgram_type == DATA_TRAN_ACK_MSG: dgram = struct.pack('!HBI', dgram_flag, DATA_TRAN_ACK_MSG, split_index) else: dgram = '' return dgram # 解析数据报中的数据载荷 def resolv_dgram(dgram, dgram_flag = None): # 载荷长度不足DGRAM_MIN_SIZE视为错误数据 dgram_len = len(dgram) if dgram_len < DGRAM_MIN_SIZE: return None # 载荷的数据报标识和参数中的不一致，视为错误数据，参数为None表示忽略该判断 recv_dgram_flag, recv_dgram_type = struct.unpack('!HB', dgram[0:3]) if dgram_flag != None and recv_dgram_flag != dgram_flag: return None # 根据载荷中的数据报类型不同作出相应的解析 if recv_dgram_type == SHACKHANDS_MSG: # 服务端提取数据报标识，文件名称 filename, = struct.unpack('!256s', dgram[3:]) return SHACKHANDS_MSG, recv_dgram_flag, filename elif recv_dgram_type == SHACKHANDS_ACK_MSG: # 客户端提取数据传输阶段的服务器端口 recv_port, = struct.unpack('!H', dgram[3:]) return SHACKHANDS_ACK_MSG, recv_port elif recv_dgram_type == DATA_TRAN_MSG: # 服务端提取分片标志，分片编号和数据内容 content_len = dgram_len - 8 split_flag, split_index, content = struct.unpack('!BI' + str(content_len) + 's', dgram[3:]) return DATA_TRAN_MSG, split_flag, split_index, content elif recv_dgram_type == DATA_TRAN_ACK_MSG: # 客户端提取收到的分片编号 split_index, = struct.unpack('!I', dgram[3:]) return DATA_TRAN_ACK_MSG, split_index else: return None # 客户端线程 def t_client(): client = Client() while True: if client.status == SHAKEHANDS_STATUS: client_shakehands(client) elif client.status == DATA_TRAN_STATUS: client_data_tran(client) else: pass # 客户端握手阶段 def client_shakehands(client): # 初始化client client.server_ip = input('please input ip address: ') client.filepath = input('please input filepath: ') client.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) client.server_port = SERVER_PORT client.server_addr = (client.server_ip, client.server_port) # 发送握手消息 dgram = create_dgram( client.dgram_flag, SHACKHANDS_MSG, filename = os.path.basename(client.filepath)) ret = client.sock.sendto(dgram, client.server_addr) print('client: send shakehand packet length: ' + str(ret) + '\n') # 接收握手确认消息 client.sock.settimeout(SHACKHANDS_TIMEOUT) try: while True: # 循环接收数据 data, _ = client.sock.recvfrom(DGRAM_MAX_SIZE) result = resolv_dgram(data, client.dgram_flag) # 收到的是握手确认消息，更新服务端端口，进入数据传输阶段 if result != None and result[0] == SHACKHANDS_ACK_MSG: print('client: recv shakehand ack port:' + str(result[1]) + '\n') client.server_port = result[1] client.server_addr = (client.server_ip, client.server_port) break except socket.timeout: # 超时则停止握手，放弃本次文件传输 print('client: shakehand connect timeout\n') client.sock.close() client.dgram_flag += 1 return #except socket.error: # 捕获其他错误，主要是服务端未上线时导致的icmp不可达错误，因为会导致后续的接收逻辑出现问题 # print 'client: shakehand socket error\n' # client.sock.close() # client.dgram_flag += 1 # return # 进入数据传输阶段，更新客户端状态，并更改超时时间 client.status = DATA_TRAN_STATUS client.sock.settimeout(DATA_TRAN_TIMEOUT) # 客户端数据传输阶段 def client_data_tran(client): block_getter = get_file_block(client.filepath) # 获取读取文件内容的生成器 split_index = 0 # 初始化分片编号 # 循环发送分片数据 # 采取停等方式：发送编号为index的数据，等收到相应的回复后才发送编号为index+1的数据 while True: # 读取文件数据并构造数据报载荷 block = next(block_getter) # 读取下一个block split_flag = 1 if block == None: # 表示文件已读取完毕 block = ''.encode('UTF-8') split_flag = 0 dgram = create_dgram( client.dgram_flag, DATA_TRAN_MSG, split_flag = split_flag, split_index = split_index, data = block, data_len = len(block)) # 发�