clientmain.cpp

由于linux作服务器运行时,时常会出现系统时间不正确现象,现提供完整的时间服务器和客户端程序,由window提供时间服务器端供多台Linux服务器获取window上时间并做出时间调整.

#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <netdb.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <iostream>

typedef int SOCKLEN;
typedef unsigned long DWORD;
typedef unsigned long long ULONGLONG;
typedef struct _FILETIME{
    DWORD dwLowDateTime;
    DWORD dwHighDateTime;
} FILETIME;
typedef union _ULARGE_INTEGER {
  struct {
    DWORD LowPart;
    DWORD HighPart;
  };
  struct {
    DWORD LowPart;
    DWORD HighPart;
  } u;
  ULONGLONG QuadPart;
} ULARGE_INTEGER;

time_t FileTimeToTime_t(FILETIME* pFileTime)
{
    time_t ret;
    ULARGE_INTEGER uli;

    uli.LowPart = pFileTime->dwLowDateTime;
    uli.HighPart = pFileTime->dwHighDateTime;

    ULONGLONG offset = 116444736;
    ret = (uli.QuadPart - (offset * 1000000000)) / 10000000;

    return ret;
}

// recive
static int Receive(int fd, char* szText, int len)
{
    int cnt;
    int rc;
    
    cnt = len;
    while (cnt>0){
        rc = recv(fd, szText, cnt, 0);

        if (rc < 0)
            return -1;
        if (rc ==0 )
            return len - cnt;
 
        szText += rc;
        cnt -= rc;
    }
    return len;
}

// send
static int Send(int fd, char* szText, int len)
{
    int cnt;
    int rc;


    cnt = len;
    while (cnt > 0){
        rc = send(fd, szText, cnt, 0);
   
        if (rc < 0)
            return -1;
        if (rc == 0)
            return len - cnt;

        szText += rc;
        cnt -= rc;
    }
   
    return len;
}

int update_time_from_server(const char* serverIP, int serverPort)
{
    int fd;
   
    std::cout << "Create socket...";
    fd = socket(AF_INET, SOCK_STREAM, 0);
    if (fd < 0){
        std::cout << "[fail]!" << std::endl;
        return -1;
    }
    std::cout << "[sucess]!" << std::endl;

    sockaddr_in local;
    memset(&local, 0, sizeof(local));

    // setup the server data
    local.sin_family = AF_INET;
    local.sin_port = htons(serverPort);
    local.sin_addr.s_addr = inet_addr(serverIP);

    // try to connect to server...
    std::cout << "Connect to server...";  
    if (connect(fd, (sockaddr*)&local, sizeof(local)) < 0){
        close(fd);

        std::cout << "[fail]!" << std::endl;
        return -1;
    }
    std::cout << "[sucess]!" << std::endl;

    // send the data to server, 
    std::string data;
    data.resize(48);
    data[0] = 0x1B;

    std::cout << "Send test data to server...";
    if (48 != Send(fd, &data[0], data.size())){
        std::cout << "[fail]!" << std::endl;
        close(fd);
        return -1;
    }
    std::cout << "[sucess]!" << std::endl;

    std::cout << "Recive data from server...";
    if (48 != Receive(fd, &data[0], data.size())){
        std::cout << "[fail]!" << std:: endl;
        close(fd);
        return -1;
    }
    std::cout << "[success]!" << std::endl;

    std::cout << "Checking the data..." << std::endl;
    if (data[0] == 0x1C){
        std::cout << "Data from server is valide!" << std::endl;

        FILETIME t2, t3;
        memcpy(&t2, &data[32], sizeof(FILETIME));
        memcpy(&t3, &data[40], sizeof(FILETIME));
#if 0
        time_t* prawtime = (time_t*)&data[32];
        tm* ptm = gmtime(prawtime);
        if (ptm != NULL){
            std::cout << "[year/month/day/hour]: [" 
                      << ptm->tm_year << "/"
                      << ptm->tm_mon << "/"
                      << ptm->tm_mday << "/"
                      << ptm->tm_hour << "]";
        }

#else
        time_t rawtime = FileTimeToTime_t(&t2);
        tm* ptm = gmtime(&rawtime);
        if (ptm != NULL){
            std::cout << "[year/month/day hour:minut:second]: [" 
                      << ptm->tm_year + 1900 << "/"
                      << ptm->tm_mon + 1 << "/"
                      << ptm->tm_mday << " "
                      << ptm->tm_hour+8 << ":"
                      << ptm->tm_min << ":"
                      << ptm->tm_sec << "]" << std::endl;
        }
        if (stime(&rawtime)){
            std::cout << "Setting time error!" << std::endl;
        }
#endif
    }
    else{
        std::cout << "Data from server is invalide!" << std::endl;
        close(fd);
        return -1;
    }
 
    std::cout << "Done sucess!!!" << std::endl;   
    close(fd);
    return 0;
}

int main(int argc, char* argv[])
{
    const unsigned int checkTime = 600;
    const char* serverIP = "127.0.0.1";
    int serverPort = 19872;
    int checkNum = 1;
    
    bool daemonMode = false;
	if ( argc == 2 && strcmp (argv[1], "-d") == 0)
	{
		daemonMode = true;
	}
#ifndef  WIN32
	signal (SIGPIPE, SIG_IGN );
	signal (SIGSEGV, SIG_IGN );
	signal (SIGALRM, SIG_IGN );
	if (daemonMode) 
	{
		daemon (1, 0);
	}
#endif
    while (true) {
        std::cout << "Connect to server " << serverIP << " : " << serverPort << std::endl;
        update_time_from_server(serverIP, serverPort);
        checkNum ++;

        std::cout << "Try again " << checkTime << " seconds later..." << std::endl;
        sleep(checkTime);
    }
    return 0;
}