iOS 64bit ntpdate don't work properly with arm64 flag - ios

Question

I have a function (ANSI C) to retrieve time for our ntpd server.
This code work properly when I compile 32bit but doesn't work if I compile in armv64.
It works properly on iPhone 4,4S,5 (32bit), it doesn't work properly on Iphone 5s,6,6S (64bit).
I think that the problem is:
tmit=ntohl((time_t)buf[10]); //# get transmit time
time_t is now 8byte when compiled in armv64.....
Underneath you can find the source code...
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);
}

Answer 1

I Solved the Problem!!!!!!!!!
uint32_t buf[maxlen];
uint32_t tmit;
instead of:
unsigned long buf[maxlen];
int tmit;
Defining a variable of type time_t
time_t tmit_temp=tmit;
printf("%d-->Time: %s\n",tmit,ctime((const time_t)&tmit_temp));
strftime(ora, 20, "%T", localtime((const time_t)&tmit_temp));
This works properly!!! ;-)