Question

我有一个函数（ANSI C）来检索我们的ntpd服务器的时间。

当我编译32位时，此代码正常工作，但如果我在armv64中编译，则无法正常工作。它适用于iPhone 4,4S，5（32位），在Iphone 5s，6,6S（64bit）上无法正常工作。

我认为问题是：

tmit=ntohl((time_t)buf[10]); //# get transmit time

在armv64中编译时，

time_t现在是8byte .....

在下面你可以找到源代码......

Output Correct with Iphone 5 Simulator (32bit) ---------------------------

xxx.xxx.xxx.xxx PORT 123
sendto-->48
prima recv
recv-->48
tmit=-661900093
tmit=1424078403
1424078403-->Time: Mon Feb 16 10:20:03 2015

10:20:03 --> 37203


---------------------------------------------------------
Output Wrong with Iphone 6 Simulator (64bit) ---------------------------
xxx.xxx.xxx.xxx PORT 123
sendto-->48
prima recv
recv-->48
tmit=19612797
tmit=2105591293
2105591293-->Time: Tue Nov 19 00:47:09     38239
00:47:09 --> 2829
//---------------------------------------------------------------------------
long ntpdate(char *hostname) {

    //ntp1.inrim.it (193.204.114.232)
    //ntp2.inrim.it (193.204.114.233)

    int     portno=NTP_PORT; //NTP is port 123
    int     maxlen=1024;     //check our buffers
    int     i=0;         // misc var i
    unsigned char msg[48]={010,0,0,0,0,0,0,0,0}; // the packet we send
    unsigned long  buf[maxlen]; // the buffer we get back
    //struct in_addr ipaddr; //
    struct protoent *proto; //
    struct sockaddr_in server_addr;
    int s; // socket
    int tmit; // the time -- This is a time_t sort of
    char ora[20]="";


    //
    //#we use the system call to open a UDP socket
    //socket(SOCKET, PF_INET, SOCK_DGRAM, getprotobyname("udp")) or die "socket: $!";
    proto=getprotobyname("udp");
    s=socket(PF_INET, SOCK_DGRAM, proto->p_proto);
    if(s==-1) {
        //printf("ERROR socket=%d\n",s);
        return -1;
    }

    //Setto il timeout per la ricezione --------------------

    struct timeval          tv;

    tv.tv_sec       = TIMEOUT_NTP; //sec
    tv.tv_usec      = 0;

    if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(struct timeval)) != 0)
    {
        //printf("Error assigning socket option");
        return -1;
    }


    memset( &server_addr, 0, sizeof( server_addr ));
    server_addr.sin_family=AF_INET;


    //trasformo il nome in ip
    struct hostent *hp = gethostbyname(hostname);

    if (hp == NULL) {
        return -1;
    } else {
        sprintf(hostname_ip, "%s", inet_ntoa( *( struct in_addr*)( hp -> h_addr_list[0])));

    }
#ifdef LOG_NTP
    printf("%s-->%s PORT %d\n",hostname,hostname_ip,portno);
#endif

    server_addr.sin_addr.s_addr = inet_addr(hostname_ip);
    server_addr.sin_port=htons(portno);

    //printf("ipaddr (in hex): %x\n",server_addr.sin_addr);

    /*
     * build a message.  Our message is all zeros except for a one in the
     * protocol version field
     * msg[] in binary is 00 001 000 00000000
     * it should be a total of 48 bytes long
     */


    // send the data
    i=sendto(s,msg,sizeof(msg),0,(struct sockaddr *)&server_addr,sizeof(server_addr));
#ifdef LOG_NTP
    printf("sendto-->%d\n",i);
#endif

    if (i==-1)
        return -1;

#ifdef LOG_NTP
    printf("prima recv\n");
#endif

    // get the data back
    i=recv(s,buf,sizeof(buf),0);

#ifdef LOG_NTP
    printf("recv-->%d\n",i);

#endif

    if (i==-1)
    {
#ifdef LOG_NTP
        printf("Error: %s (%d)\n", strerror(errno), errno);
#endif
        return -1;
    }

    //printf("recvfr: %d\n",i);

    //We get 12 long words back in Network order

     //for(i=0;i<12;i++)
     //printf("%d\t%-8x\n",i,ntohl(buf[i]));


    /*
     * The high word of transmit time is the 10th word we get back
     * tmit is the time in seconds not accounting for network delays which
     * should be way less than a second if this is a local NTP server
     */

    tmit=ntohl((time_t)buf[10]); //# get transmit time


#ifdef LOG_NTP
    printf("tmit=%d\n",tmit);
#endif
    /*
     * Convert time to unix standard time NTP is number of seconds since 0000
     * UT on 1 January 1900 unix time is seconds since 0000 UT on 1 January
     * 1970 There has been a trend to add a 2 leap seconds every 3 years.
     * Leap seconds are only an issue the last second of the month in June and
     * December if you don't try to set the clock then it can be ignored but
     * this is importaint to people who coordinate times with GPS clock sources.
     */

    tmit-= 2208988800U;

#ifdef LOG_NTP
    printf("tmit=%d\n",tmit);
#endif
    /* use unix library function to show me the local time (it takes care
     * of timezone issues for both north and south of the equator and places
     * that do Summer time/ Daylight savings time.
     */


    //#compare to system time
#ifdef LOG_NTP
    //printf("%d-->Time: %s\n",tmit,ctime((const time_t)&tmit));
    printf("%d-->Time: %s\n",tmit,ctime((const time_t)&tmit));
#endif


    //i=time(0);
   //printf("%d-%d=%d\n",i,tmit,i-tmit);
    //printf("System time is %d seconds off\n",i-tmit);


    //Prendo l'ora e la converto in HH:MM:SS --> Sec
    strftime(ora, 20, "%T", localtime((const time_t)&tmit));

#ifdef LOG_NTP
    printf("%s --> %ld\n",ora, C2TIME(ora));
#endif  
    return C2TIME(ora);

}

iOS 64bit ntpdate与arm64标志无法正常工作

0 个答案: