由于工作中一些需求，需要完成C++与Python之间的Socket通信，基于自定义协议的通信。
环境：
Centos 6.5+gcc (GCC) 4.8.2+kernel 2.6.32+cmake version 2.8.12.2+Python 3.4.3(windows环境)
Bug修复请参考：
难点：
1:Python Socket Struct解析。
由于C++的Socket开发是基于自定义协议的，通信中加入了结构体，在Python中需要对socket通信中的结构体进行解析。Python中正好有struct模块，所以，可以借助该模块进行自定义协议的通信。
2:Python中自定义协议与服务器端协议统一
客户端协议的解析读取，发送等都要与服务端相同，不然势必无法正常按照协议进行通信。
代码如下：
服务端(基于C语言)：
socket_server.c:
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "msg.h"
#define MAXCONNECTIONS 100
int sockfd;
void sig_handler(int signo) {
if (signo == SIGINT) {
printf("server close\n");
close(sockfd);
exit(1);
}
}
/*输出连接上来的客户端的相关信息*/
void out_addr(struct sockaddr_in *clientaddr) {
//将端口从网络字节序转换成主机字节序
int port = ntohs(clientaddr->sin_port);
char ip[16];
memset(ip, 0, sizeof(ip));
//将ip地址从网络字节序转换成点分十进制
inet_ntop(AF_INET, &clientaddr->sin_addr.s_addr, ip, sizeof(ip));
printf("client: %s(%d) connected\n", ip, port);
}
/*输出服务器端时间*/
void do_service(int fd) {
/*和客户端进行读写操作(双向通信)*/
char buff[1024];
while (1)
{
memset(buff, 0, sizeof(buff));
printf("start read and write...\n");
size_t size;
//printf("sizeof buff is %d = \n", sizeof(buff));
if ((size = read_msg(fd, buff, sizeof(buff))) < 0) {
print("protocal error");
break;
}
else if (size == 0) {
break;
}
else {
printf("Server Received = %s\n", buff);
//printf("socket_server send size = %d \n", strlen(buff));
//printf("socket_server fd = %d \n", fd);
//printf("socket_server send size = %d \n", sizeof(buff));
//printf("socket_server send size = %d \n", strlen(buff));
if (write_msg(fd, buff, sizeof(buff)) < 0) {
printf("errorno = %d", errno);
if (errno == EPIPE) {
break;
}
perror("protocal error");
}
}
}
}
void out_fd(int fd) {
struct sockaddr_in addr;
socklen_t len = sizeof(addr);
//从fd中获取连接的客户端相关信息
if (getpeername(fd, (struct sockaddr *)&addr, &len) < 0) {
perror("getpeername error");
return;
}
char ip[16];
memset(ip, 0, sizeof(ip));
int port = ntohs(addr.sin_port);
inet_ntop(AF_INET, &addr.sin_addr.s_addr, ip, sizeof(ip));
printf("%16s(%5d) closed!\n", ip, port);
}
void *th_fn(void *arg) {
int fd = (int)arg;
do_service(fd);
out_fd(fd);
close(fd);
return (void *)0;
}
int main(int argc, char *argv[]) {
if (argc < 2) {
printf("usage: %s #port\n", argv[0]);
exit(1);
}
if (signal(SIGINT, sig_handler) == SIG_ERR) {
perror("signal sigint error");
exit(1);
}
signal(SIGPIPE, SIG_IGN);
/*步骤1:创建socket(套接字)*/
sockfd = socket(AF_INET, SOCK_STREAM, 0);
/*步骤2:将socket和地址(包括ip,port)进行绑定*/
struct sockaddr_in serveraddr;
memset(&serveraddr, 0, sizeof(serveraddr));
/*向地址中填入ip,port,internet地址簇类型*/
serveraddr.sin_family = AF_INET; //ipv4
serveraddr.sin_port = htons(atoi(argv[1])); //port
serveraddr.sin_addr.s_addr = INADDR_ANY; //接收所有网卡地址
if (bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0) {
perror("bind error");
exit(1);
}
/*步骤3:调用listen函数启动监听(指定port监听)
通知系统去接受来自客户端的连接请求
第二个参数:指定队列的长度*/
if (listen(sockfd, MAXCONNECTIONS) < 0) {
perror("listen error");
exit(1);
}
/*步骤4:调用accept函数从队列中获得一个客户端的连接请求，
并返回新的socket描述符*/
struct sockaddr_in clientaddr;
socklen_t clientaddr_len = sizeof(clientaddr);
/*设置线程的分离属性*/
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
while (1)
{
int fd = accept(sockfd, NULL, NULL);
if (fd < 0) {
perror("accept error");
continue;
}
/*步骤5:启动子线程去调用IO函数(read/write)和连接的客户端进行双向通信*/
pthread_t th;
int err;
/*以分离状态启动子线程*/
if ((err = pthread_create(&th, &attr, th_fn, (void *)fd)) != 0) {
perror("pthread create error");
}
pthread_attr_destroy(&attr);
}
return 0;
}
msg.h:
#ifndef __MSG_H__
#define __MSG_H__
#include
typedef struct {
//协议头部
char head[13];
char checknum; //校验码
//协议体部
char buff[1024]; //数据
} Msg;
/************************************************************************/
/* 发送一个基于自定义协议的message
* 发送的数据存放在buff中*/
/************************************************************************/
extern int write_msg(int sockfd, char *buff, size_t len);
/************************************************************************/
/* 读取一个基于自定义协议的message
* 读取的数据存放在buff中*/
/************************************************************************/
extern int read_msg(int sockfd, char *buff, size_t len);
#endif
msg.c:
#include "msg.h"
#include
#include
#include
#include
/*计算校验码*/
static unsigned char msg_check(Msg *message) {
//unsigned char s = 0;
int s = 0;
int i;
//printf("message head = %s \n", message->head);
//printf("message buff = %s \n", message->buff);
for (i = 0; i < sizeof(message->head); i++) {
//printf("i1 = %c \n", message->head[i]);
s = ((s + message->head[i]) % 255);
//printf("i1 checknum = %d \n", s);
}
for (i = 0; i < sizeof(message->buff); i++) {
//printf("i2 = %c \n", message->buff[i]);
s = ((s + message->buff[i]) % 255);
//printf("i2 checknum = %d \n", s);
}
//printf("msg_check num is %d \n", s);
return s;
}
/************************************************************************/
/* 发送一个基于自定义协议的message
* 发送的数据存放在buff中*/
/************************************************************************/
int write_msg(int sockfd, char *buff, size_t len) {
//printf("write_msg1 \n");
Msg message;
memset(&message, 0, sizeof(message));
strcpy(message.head, "gmqh_sh_2016");
memcpy(message.buff, buff, len);
message.checknum = msg_check(&message);
//printf("write_msg2 \n");
if (write(sockfd, &message, sizeof(message)) != sizeof(message)) {
return -1;
}
}
/************************************************************************/
/* 读取一个基于自定义协议的message
* 读取的数据存放在buff中*/
/************************************************************************/
int read_msg(int sockfd, char *buff, size_t len) {
//printf("read_msg1 \n");
Msg message;
memset(&message, 0, sizeof(message));
size_t size;
//printf("read_msg1-1 \n");
if ((size = read(sockfd, &message, sizeof(message))) < 0) {
//printf("read_msg1-2 \n");
return -1;
}
else if (size == 0) {
return 0;
}
//printf("read_msg2 \n");
//进行校验码验证,判断接收到message是否完整
unsigned char s = msg_check(&message);
//printf("read_msg message.head = %s \n", message.head);
//printf("read_msg message.checknum = %d \n", message.checknum);
//printf("read_msg message.buff = %s \n", message.buff);
//printf("read_msg checknum cal = %d \n", s);
if ((s == (unsigned char)message.checknum) && (!strcmp("gmqh_sh_2016", message.head))) {
//printf("read_msg3 \n");
memcpy(buff, message.buff, len);
return sizeof(message);
}
//printf("read_msg4 \n");
return -1;
}
CMakeLists.txt:
cmake_minimum_required(VERSION 2.8)
#project name
project(multi_thread_socket_demo)
set(CMAKE_CXX_COMPILER "g++")
#set compiler for c++ language
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -lrt -lpthread -D_GLIBCXX_USE_NANOSLEEP")
#source files(can add source files manually)
#set(SOURCE_FILES main.cpp ThostFtdcMdApi.h ThostFtdcTraderApi.h ThostFtdcUserApiDataType.h ThostFtdcUserApiStruct.h MdSpi.cpp MdSpi.h TdSpi.cpp TdSpi.h CTP_Manager.cpp CTP_Manager.h Login.h Order.cpp Order.h User.cpp User.h Utils.cpp Utils.h DBManager.h DBManager.cpp Trader.h Trader.cpp FutureAccount.h FutureAccount.cpp Strategy.h Strategy.cpp Algorithm.h Algorithm.cpp)
#source directory(add source files automatically)
aux_source_directory(. SOURCE_FILES)
find_package(Threads)
#set extern libraries
#set(LIBRARIES libthostmduserapi.so libthosttraderapi.so libmongoclient.so libboost_thread.so libboost_system.so libboost_regex.so)
#add execute file
add_executable(multi-thread-socket-server ${SOURCE_FILES})
#add link library
target_link_libraries(multi-thread-socket-server ${CMAKE_THREAD_LIBS_INIT})
编译方式：
cmake .
make
客户端(基于Python语言)：
socket_client.py:
# -*- coding: utf-8 -*-
from collections import namedtuple
import socket
import sys
import struct
Message = namedtuple("Message", "head checknum buff")
# m = Message("gmqh", 0, "hello, world")
# 计算校验码
def msg_check(message):
#将收到的head以及buff分别累加 % 255
checknum = 0
for i in message.head:
# print("i1 = %c \n" % i)
checknum = ((checknum + ord(i)) % 255)
# print("i1 checknum = %d \n" % checknum)
for i in message.buff:
# print("i2 = %c \n" %i)
checknum = ((checknum + ord(i)) % 255)
# print("i2 checknum = %d \n" % checknum)
return checknum
#发送数据
def write_msg(sockfd, buff):
# print("send buff = ", buff)
# print("send buff len = ", len(buff))
# print("send buff = ", buff.encode())
# print("send buff len = ", len(buff.encode()))
#构造Message
m = Message("gmqh_sh_2016", 0, buff)
#数据发送前,将校验数据填入Message结构体
checknum = msg_check(m)
m = Message("gmqh_sh_2016", checknum, buff)
# print("send m.buff = ", m.buff.encode())
# print("send m.checknum = ", m.checknum)
#打包数据(13位的head,1位校验码,不定长数据段)
data = struct.pack(">13s1B" + str(len(m.buff.encode()) + 1) + "s", m.head.encode(), m.checknum, m.buff.encode());
print("send data = ", data)
#发送数据
size = sockfd.send(data)
# print(size)
return size
#读取数据
def read_msg(sockfd):
try:
#接收数据1038个字节(与服务器端统一:13位head+1位checknum+1024数据段)
data = sockfd.recv(1038)
except socket.error as e:
print(e)
#解包数据
head, checknum, buff = struct.unpack(">13s1B"+ str(len(data) - 14) +"s", data)
# print(head, checknum, buff, '\n')
#将解包的数据封装为Message结构体
m = Message(head.decode().split('\x00')[0], checknum, buff.decode())
tmp_checknum = msg_check(m)
m = Message(head.decode().split('\x00')[0], tmp_checknum, buff.decode())
#将收到的标志位与收到数据重新计算的标志位进行对比+head内容对比
if ((m.checknum == checknum) and (m.head == "gmqh_sh_2016")):
#打印接收到的数据
print("receive data = ", m.buff)
return 1
else:
return -1
if __name__ == '__main__':
#创建socket套接字
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
if s:
# 连接服务器: IP,port
try:
#进行与服务端的连接(ip地址根据实际情况进行更改)
s.connect(("192.168.1.12", 8888))
except socket.error as e:
print("socket error", e)
sys.exit(1)
#输入提示符
prompt = b'->'
while True:
buff = input(prompt)
if buff == "":
continue
#发送数据
if (write_msg(s, buff) < 0):
print("write msg error")
continue
else:
#接收数据
if (read_msg(s) < 0):
print("read msg error")
continue
pass
s.close()
else:
print("socket error")运行效果：
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