功能描述

使用socket通信，实现服务端功能和客户端功能，并进行消息的交互，实现跨进程通信。

相关代码

• test_socket.h

#ifndef __TEST_SOCKET_H__
#define __TEST_SOCKET_H__

#define SOCK_ERR(fmt...) do { \
    printf("[SOCK]" fmt);     \
    printf("\r\n");           \
} while(0)

#define VOS_OK 0
#define VOS_ERR 1
#define VOS_TRUE 1
#define VOS_FALSE 0

typedef void VOID;

typedef char CHAR;
typedef int INT32;

typedef unsigned char UINT8;
typedef unsigned short UINT16;
typedef unsigned int UINT32;
typedef unsigned long long UINT64;

#define SOCK_PROCESS_TYPE_NAME_SERVER "server"
#define SOCK_PROCESS_TYPE_NAME_CLIENT "client"

#define SOCK_PROCESS_TYPE_SERVER 0
#define SOCK_PROCESS_TYPE_CLIENT 1

#define SOCK_DEFAULT_DST_ADDR "127.0.0.1"
#define SOCK_DEFAULT_DST_PORT 1500

typedef struct {
    UINT16 family;
    UINT16 port;
    UINT32 addr;
    UINT8  resv[8];
} SOCK_ADDR_S;

typedef struct {
    UINT32 type;
    CHAR*  addr;
    UINT16 port;
} SOCK_PARA_S;

#endif

• test_socket.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "test_socket.h"

VOID SOCK_InitPara(SOCK_PARA_S *pPara, int argc, char *argv[])
{
    argc--;
    argv++;

    if (argc > 0 && strcmp(SOCK_PROCESS_TYPE_NAME_CLIENT, argv[0]) == 0) {
        pPara->type              = SOCK_PROCESS_TYPE_CLIENT;
    } else {
        pPara->type              = SOCK_PROCESS_TYPE_SERVER;
    }
    
    if (argc > 1) {
        pPara->addr              = argv[1];
    } else {
        pPara->addr              = SOCK_DEFAULT_DST_ADDR;
    }

    if (argc > 2) {
        pPara->port              = (UINT16)atol(argv[2]);
    } else {
        pPara->port              = SOCK_DEFAULT_DST_PORT;
    }
}

UINT32 SOCK_MainServer(SOCK_PARA_S *pPara)
{
    INT32 ret;

    // socket

    INT32 serverHandle = socket(AF_INET, SOCK_STREAM, 0);
    if (serverHandle == -1) {
        SOCK_ERR("socket Fail!");
        return VOS_ERR;
    }
    SOCK_ERR("socket(%d) create ok", serverHandle);

    // bind

    SOCK_ADDR_S addr          = {0};
    addr.family               = AF_INET;
    addr.port                 = htons(pPara->port);
    addr.addr                 = inet_addr(pPara->addr);

    ret = bind(serverHandle, (struct sockaddr *)&addr, sizeof(SOCK_ADDR_S));
    if (ret < 0) {
        SOCK_ERR("socket bind Err(%d)!", ret);
        return VOS_ERR;
    }

    // listen

    ret = listen(serverHandle, 5);
    if (ret != VOS_OK) {
        SOCK_ERR("socket listen Err(%d)!", ret);
        return VOS_ERR;
    }

    SOCK_ERR("socket accept ...");

    // accept

    INT32       clientHandle;
    SOCK_ADDR_S clientAddr;
    UINT32      clientAddrLen         = sizeof(SOCK_ADDR_S); // 注意：这里得是有效值

    while (VOS_TRUE) {
        clientHandle = accept(serverHandle, (struct sockaddr *)&clientAddr, &clientAddrLen);
        if (clientHandle == -1) {
            SOCK_ERR("socket accept Fail(%d)", clientHandle);
        } else {
            SOCK_ERR("socket accept Succ");
            ret = send(clientHandle, "Hello World!", 12, 0);
            if (ret == -1) {
                SOCK_ERR("socket send Fail");
            } else {
                SOCK_ERR("socket send Succ");
            }
        }
    }
}

UINT32 SOCK_MainClient(SOCK_PARA_S *pPara)
{
    INT32 ret;

    // socket

    INT32 serverHandle = socket(AF_INET, SOCK_STREAM, 0);
    if (serverHandle == -1) {
        SOCK_ERR("socket Fail!");
        return VOS_ERR;
    }
    SOCK_ERR("socket(%d) create ok", serverHandle);

    // connet

    SOCK_ADDR_S addr          = {0};
    addr.family               = AF_INET;
    addr.port                 = htons(pPara->port);
    addr.addr                 = inet_addr(pPara->addr);

    ret = connect(serverHandle, (struct sockaddr *)&addr, sizeof(SOCK_ADDR_S));
    if (ret == -1) {
        SOCK_ERR("socket connet Fail(%d)!", ret);
        return VOS_ERR;
    }

    char buf[100] = {0};

    ret = recv(serverHandle, buf, 100, 0);
    if (ret == -1) {
        SOCK_ERR("socket recv Fail(%d)!", ret);
        return VOS_ERR;
    }
    SOCK_ERR("socket recv Succ(%s)!", buf);
}

int main(int argc, char *argv[])
{
    SOCK_PARA_S para;
    SOCK_InitPara(&para, argc, argv);

    SOCK_ERR("test socket start");

    if (para.type == SOCK_PROCESS_TYPE_SERVER) {
        (VOID)SOCK_MainServer(&para);
    } else {
        (VOID)SOCK_MainClient(&para);
    }

    SOCK_ERR("test socket end");

    return VOS_OK;
}

功能演示

• 第一步：打开Linux操作窗口，启动Server进程。

./test_socket server 127.0.0.1 1500

• 第二步：打开另一个Linux操作窗口，启动Client进程。可以观察到Client收到Server的消息，同时观察Server日志可以发现发送成功。

./test_socket client 127.0.0.1 1500

• 第三步：查看抓包。可以看到对应的TCP消息报文。