59 lines
1.1 KiB
C
59 lines
1.1 KiB
C
|
#include <config.h>
|
||
|
|
|
||
|
|
#include <ntp.h>
|
||
|
|
#include <ntp_fp.h>
|
||
|
|
#include <refidsmear.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* we want to test a refid format of:
|
||
|
|
* 254.x.y.x
|
||
|
|
*
|
||
|
|
* where x.y.z are 24 bits containing 2 (signed) integer bits
|
||
|
|
* and 22 fractional bits.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
l_fp
|
||
|
|
convertRefIDToLFP(uint32_t r)
|
||
|
|
{
|
||
|
|
l_fp temp;
|
||
|
|
|
||
|
|
r = ntohl(r);
|
||
|
|
|
||
|
|
// printf("%03d %08x: ", (r >> 24) & 0xFF, (r & 0x00FFFFFF) );
|
||
|
|
|
||
|
|
temp.l_uf = (r << 10); /* 22 fractional bits */
|
||
|
|
|
||
|
|
temp.l_ui = (r >> 22) & 0x3;
|
||
|
|
temp.l_ui |= ~(temp.l_ui & 2) + 1;
|
||
|
|
|
||
|
|
return temp;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
uint32_t
|
||
|
|
convertLFPToRefID(l_fp num)
|
||
|
|
{
|
||
|
|
uint32_t temp;
|
||
|
|
|
||
|
|
/* round the input with the highest bit to shift out from the
|
||
|
|
* fraction, then keep just two bits from the integral part.
|
||
|
|
*
|
||
|
|
* TODO: check for overflows; should we clamp/saturate or just
|
||
|
|
* complain?
|
||
|
|
*/
|
||
|
|
L_ADDUF(&num, 0x200);
|
||
|
|
num.l_ui &= 3;
|
||
|
|
|
||
|
|
/* combine integral and fractional part to 24 bits */
|
||
|
|
temp = (num.l_ui << 22) | (num.l_uf >> 10);
|
||
|
|
|
||
|
|
/* put in the leading 254.0.0.0 */
|
||
|
|
temp |= UINT32_C(0xFE000000);
|
||
|
|
|
||
|
|
// printf("%03d %08x: ", (temp >> 24) & 0xFF, (temp & 0x00FFFFFF) );
|
||
|
|
|
||
|
|
return htonl(temp);
|
||
|
|
}
|