C/C++远程开机

// 2C:4D:54:ED:08:F0
#include <stdio.h>
#include <Windows.h>
#include <winsock.h>

#pragma comment(lib,"Ws2_32.lib")

/*
    从文件通过ip获取mac
    ip:欲取ip的mac地址
    成功返回对应mac,否则返回NULL.
*/
unsigned char *GetfileMacforIp(char *ip);
/*
    远程唤醒
    mac:目标mac地址
    ps:在此之前要确保目标主板支持远程唤醒
*/
VOID RemoteStart(unsigned char *mac);

int main(void)
{
    unsigned char *mac = GetfileMacforIp("172.18.1.6");
    if (mac)
    {
        printf("%X-%X-%X-%X-%X-%X
", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
        //free(mac); 为什么无法free?
    }
    system("pause");
    return 0;
}



VOID RemoteStart(unsigned char *mac)
{
    // 存封包数据,格式为：6个0xFF为一组,16个mac地址为一组.mac地址正好是6个字节,封包总大小=6+16*6=102
    unsigned char packet[102] = { 0 };
    struct sockaddr_in addr;
    int sockfd, i, j;
    const char on = 1;
    WSADATA aaa;

    // 填充封包数据
    for (i = 0; i < 6; i++)
        packet[i] = 0xFF;
    for (i = 1; i < 17; i++)
    {
        for (j = 0; j < 6; j++)
        {
            packet[i * 6 + j] = mac[j];
        }
    }
    // 使用socket发送封包前必须初始化socket
    WSAStartup(MAKEWORD(2, 2), &aaa);
    // udp方式
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on));
    if (sockfd < 0)
    {
        printf("setsockopt filed!
");
        return;
    }
    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(10000);
    // 广播地址:255.255.255.255
    addr.sin_addr.S_un.S_addr = inet_addr("255.255.255.255");
    sendto(sockfd, (const char *)packet, sizeof(packet), 0, (struct sockaddr *)&addr, sizeof(addr));
    WSACleanup();
}

unsigned char *GetfileMacforIp(char *ip)
{
    char tmp[255] = { 0 };
    char *pos = NULL;
    char mac[20] = { 0 };
    unsigned char *mac1 = (unsigned char*)malloc(sizeof(unsigned char)*6);
    //unsigned char mac1[6] = { 0 };

    FILE *wj = NULL;
    fopen_s(&wj, "ipmac.txt", "r");
    if (!wj)
    {
        printf("file can`t open!
");
        return 0;
    }
    while (!feof(wj))
    {
        memset(tmp, 0, 255);
        fgets(tmp, 255, wj);
        pos = strstr(tmp, ip);
        if (pos)
        {
            // 文本形式Mac地址
            memmove(mac, tmp + strlen(ip) + 1, 17);
            // 转字节形式Mac地址
            sscanf_s(mac, "%x-%x-%x-%x-%x-%x", &mac1[0], &mac1[1], &mac1[2], &mac1[3], &mac1[4], &mac1[5]);
            //printf("%X %X %X %X %X %X
",mac1[0],mac1[1],mac1[2],mac1[3],mac1[4],mac1[5]);
            break;
        }
    }
    fclose(wj);
    return mac1;
}

核心函数是RemoteStart，GetfileMacforIp是我在本地存放的一个ip和mac地址的数据文件。