freebsd-skq/contrib/ntp/include/ntp_fp.h
2017-03-23 22:06:06 +00:00

424 lines
13 KiB
C

/*
* ntp_fp.h - definitions for NTP fixed/floating-point arithmetic
*/
#ifndef NTP_FP_H
#define NTP_FP_H
#include "ntp_types.h"
/*
* NTP uses two fixed point formats. The first (l_fp) is the "long"
* format and is 64 bits long with the decimal between bits 31 and 32.
* This is used for time stamps in the NTP packet header (in network
* byte order) and for internal computations of offsets (in local host
* byte order). We use the same structure for both signed and unsigned
* values, which is a big hack but saves rewriting all the operators
* twice. Just to confuse this, we also sometimes just carry the
* fractional part in calculations, in both signed and unsigned forms.
* Anyway, an l_fp looks like:
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Integral Part |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Fractional Part |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
typedef struct {
union {
u_int32 Xl_ui;
int32 Xl_i;
} Ul_i;
u_int32 l_uf;
} l_fp;
#define l_ui Ul_i.Xl_ui /* unsigned integral part */
#define l_i Ul_i.Xl_i /* signed integral part */
/*
* Fractional precision (of an l_fp) is actually the number of
* bits in a long.
*/
#define FRACTION_PREC (32)
/*
* The second fixed point format is 32 bits, with the decimal between
* bits 15 and 16. There is a signed version (s_fp) and an unsigned
* version (u_fp). This is used to represent synchronizing distance
* and synchronizing dispersion in the NTP packet header (again, in
* network byte order) and internally to hold both distance and
* dispersion values (in local byte order). In network byte order
* it looks like:
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Integer Part | Fraction Part |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
typedef int32 s_fp;
typedef u_int32 u_fp;
/*
* A unit second in fp format. Actually 2**(half_the_bits_in_a_long)
*/
#define FP_SECOND (0x10000)
/*
* Byte order conversions
*/
#define HTONS_FP(x) (htonl(x))
#define NTOHS_FP(x) (ntohl(x))
#define NTOHL_MFP(ni, nf, hi, hf) \
do { \
(hi) = ntohl(ni); \
(hf) = ntohl(nf); \
} while (FALSE)
#define HTONL_MFP(hi, hf, ni, nf) \
do { \
(ni) = htonl(hi); \
(nf) = htonl(hf); \
} while (FALSE)
#define HTONL_FP(h, n) \
HTONL_MFP((h)->l_ui, (h)->l_uf, (n)->l_ui, (n)->l_uf)
#define NTOHL_FP(n, h) \
NTOHL_MFP((n)->l_ui, (n)->l_uf, (h)->l_ui, (h)->l_uf)
/* Convert unsigned ts fraction to net order ts */
#define HTONL_UF(uf, nts) \
do { \
(nts)->l_ui = 0; \
(nts)->l_uf = htonl(uf); \
} while (FALSE)
/*
* Conversions between the two fixed point types
*/
#define MFPTOFP(x_i, x_f) (((x_i) >= 0x00010000) ? 0x7fffffff : \
(((x_i) <= -0x00010000) ? 0x80000000 : \
(((x_i)<<16) | (((x_f)>>16)&0xffff))))
#define LFPTOFP(v) MFPTOFP((v)->l_i, (v)->l_uf)
#define UFPTOLFP(x, v) ((v)->l_ui = (u_fp)(x)>>16, (v)->l_uf = (x)<<16)
#define FPTOLFP(x, v) (UFPTOLFP((x), (v)), (x) < 0 ? (v)->l_ui -= 0x10000 : 0)
#define MAXLFP(v) ((v)->l_ui = 0x7fffffffu, (v)->l_uf = 0xffffffffu)
#define MINLFP(v) ((v)->l_ui = 0x80000000u, (v)->l_uf = 0u)
/*
* Primitive operations on long fixed point values. If these are
* reminiscent of assembler op codes it's only because some may
* be replaced by inline assembler for particular machines someday.
* These are the (kind of inefficient) run-anywhere versions.
*/
#define M_NEG(v_i, v_f) /* v = -v */ \
do { \
(v_f) = ~(v_f) + 1u; \
(v_i) = ~(v_i) + ((v_f) == 0); \
} while (FALSE)
#define M_NEGM(r_i, r_f, a_i, a_f) /* r = -a */ \
do { \
(r_f) = ~(a_f) + 1u; \
(r_i) = ~(a_i) + ((r_f) == 0); \
} while (FALSE)
#define M_ADD(r_i, r_f, a_i, a_f) /* r += a */ \
do { \
u_int32 add_t = (r_f); \
(r_f) += (a_f); \
(r_i) += (a_i) + ((u_int32)(r_f) < add_t); \
} while (FALSE)
#define M_ADD3(r_o, r_i, r_f, a_o, a_i, a_f) /* r += a, three word */ \
do { \
u_int32 add_t, add_c; \
add_t = (r_f); \
(r_f) += (a_f); \
add_c = ((u_int32)(r_f) < add_t); \
(r_i) += add_c; \
add_c = ((u_int32)(r_i) < add_c); \
add_t = (r_i); \
(r_i) += (a_i); \
add_c |= ((u_int32)(r_i) < add_t); \
(r_o) += (a_o) + add_c; \
} while (FALSE)
#define M_SUB(r_i, r_f, a_i, a_f) /* r -= a */ \
do { \
u_int32 sub_t = (r_f); \
(r_f) -= (a_f); \
(r_i) -= (a_i) + ((u_int32)(r_f) > sub_t); \
} while (FALSE)
#define M_RSHIFTU(v_i, v_f) /* v >>= 1, v is unsigned */ \
do { \
(v_f) = ((u_int32)(v_f) >> 1) | ((u_int32)(v_i) << 31); \
(v_i) = ((u_int32)(v_i) >> 1); \
} while (FALSE)
#define M_RSHIFT(v_i, v_f) /* v >>= 1, v is signed */ \
do { \
(v_f) = ((u_int32)(v_f) >> 1) | ((u_int32)(v_i) << 31); \
(v_i) = ((u_int32)(v_i) >> 1) | ((u_int32)(v_i) & 0x80000000); \
} while (FALSE)
#define M_LSHIFT(v_i, v_f) /* v <<= 1 */ \
do { \
(v_i) = ((u_int32)(v_i) << 1) | ((u_int32)(v_f) >> 31); \
(v_f) = ((u_int32)(v_f) << 1); \
} while (FALSE)
#define M_LSHIFT3(v_o, v_i, v_f) /* v <<= 1, with overflow */ \
do { \
(v_o) = ((u_int32)(v_o) << 1) | ((u_int32)(v_i) >> 31); \
(v_i) = ((u_int32)(v_i) << 1) | ((u_int32)(v_f) >> 31); \
(v_f) = ((u_int32)(v_f) << 1); \
} while (FALSE)
#define M_ADDUF(r_i, r_f, uf) /* r += uf, uf is u_int32 fraction */ \
M_ADD((r_i), (r_f), 0, (uf)) /* let optimizer worry about it */
#define M_SUBUF(r_i, r_f, uf) /* r -= uf, uf is u_int32 fraction */ \
M_SUB((r_i), (r_f), 0, (uf)) /* let optimizer worry about it */
#define M_ADDF(r_i, r_f, f) /* r += f, f is a int32 fraction */ \
do { \
int32 add_f = (int32)(f); \
if (add_f >= 0) \
M_ADD((r_i), (r_f), 0, (uint32)( add_f)); \
else \
M_SUB((r_i), (r_f), 0, (uint32)(-add_f)); \
} while(0)
#define M_ISNEG(v_i) /* v < 0 */ \
(((v_i) & 0x80000000) != 0)
#define M_ISGT(a_i, a_f, b_i, b_f) /* a > b signed */ \
(((u_int32)((a_i) ^ 0x80000000) > (u_int32)((b_i) ^ 0x80000000)) || \
((a_i) == (b_i) && ((u_int32)(a_f)) > ((u_int32)(b_f))))
#define M_ISGTU(a_i, a_f, b_i, b_f) /* a > b unsigned */ \
(((u_int32)(a_i)) > ((u_int32)(b_i)) || \
((a_i) == (b_i) && ((u_int32)(a_f)) > ((u_int32)(b_f))))
#define M_ISHIS(a_i, a_f, b_i, b_f) /* a >= b unsigned */ \
(((u_int32)(a_i)) > ((u_int32)(b_i)) || \
((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f))))
#define M_ISGEQ(a_i, a_f, b_i, b_f) /* a >= b signed */ \
(((u_int32)((a_i) ^ 0x80000000) > (u_int32)((b_i) ^ 0x80000000)) || \
((a_i) == (b_i) && (u_int32)(a_f) >= (u_int32)(b_f)))
#define M_ISEQU(a_i, a_f, b_i, b_f) /* a == b unsigned */ \
((u_int32)(a_i) == (u_int32)(b_i) && (u_int32)(a_f) == (u_int32)(b_f))
/*
* Operations on the long fp format
*/
#define L_ADD(r, a) M_ADD((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf)
#define L_SUB(r, a) M_SUB((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf)
#define L_NEG(v) M_NEG((v)->l_ui, (v)->l_uf)
#define L_ADDUF(r, uf) M_ADDUF((r)->l_ui, (r)->l_uf, (uf))
#define L_SUBUF(r, uf) M_SUBUF((r)->l_ui, (r)->l_uf, (uf))
#define L_ADDF(r, f) M_ADDF((r)->l_ui, (r)->l_uf, (f))
#define L_RSHIFT(v) M_RSHIFT((v)->l_i, (v)->l_uf)
#define L_RSHIFTU(v) M_RSHIFTU((v)->l_ui, (v)->l_uf)
#define L_LSHIFT(v) M_LSHIFT((v)->l_ui, (v)->l_uf)
#define L_CLR(v) ((v)->l_ui = (v)->l_uf = 0)
#define L_ISNEG(v) M_ISNEG((v)->l_ui)
#define L_ISZERO(v) (((v)->l_ui | (v)->l_uf) == 0)
#define L_ISGT(a, b) M_ISGT((a)->l_i, (a)->l_uf, (b)->l_i, (b)->l_uf)
#define L_ISGTU(a, b) M_ISGTU((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf)
#define L_ISHIS(a, b) M_ISHIS((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf)
#define L_ISGEQ(a, b) M_ISGEQ((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf)
#define L_ISEQU(a, b) M_ISEQU((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf)
/*
* s_fp/double and u_fp/double conversions
*/
#define FRIC 65536.0 /* 2^16 as a double */
#define DTOFP(r) ((s_fp)((r) * FRIC))
#define DTOUFP(r) ((u_fp)((r) * FRIC))
#define FPTOD(r) ((double)(r) / FRIC)
/*
* l_fp/double conversions
*/
#define FRAC 4294967296.0 /* 2^32 as a double */
/*
* Use 64 bit integers if available. Solaris on SPARC has a problem
* compiling parsesolaris.c if ntp_fp.h includes math.h, due to
* archaic gets() and printf() prototypes used in Solaris kernel
* headers. So far the problem has only been seen with gcc, but it
* may also affect Sun compilers, in which case the defined(__GNUC__)
* term should be removed.
* XSCALE also generates bad code for these, at least with GCC 3.3.5.
* This is unrelated to math.h, but the same solution applies.
*/
#if defined(HAVE_U_INT64) && \
!(defined(__SVR4) && defined(__sun) && \
defined(sparc) && defined(__GNUC__) || \
defined(__arm__) && defined(__XSCALE__) && defined(__GNUC__))
#include <math.h> /* ldexp() */
#define M_DTOLFP(d, r_ui, r_uf) /* double to l_fp */ \
do { \
double d_tmp; \
u_int64 q_tmp; \
int M_isneg; \
\
d_tmp = (d); \
M_isneg = (d_tmp < 0.); \
if (M_isneg) { \
d_tmp = -d_tmp; \
} \
q_tmp = (u_int64)ldexp(d_tmp, 32); \
if (M_isneg) { \
q_tmp = ~q_tmp + 1; \
} \
(r_uf) = (u_int32)q_tmp; \
(r_ui) = (u_int32)(q_tmp >> 32); \
} while (FALSE)
#define M_LFPTOD(r_ui, r_uf, d) /* l_fp to double */ \
do { \
double d_tmp; \
u_int64 q_tmp; \
int M_isneg; \
\
q_tmp = ((u_int64)(r_ui) << 32) + (r_uf); \
M_isneg = M_ISNEG(r_ui); \
if (M_isneg) { \
q_tmp = ~q_tmp + 1; \
} \
d_tmp = ldexp((double)q_tmp, -32); \
if (M_isneg) { \
d_tmp = -d_tmp; \
} \
(d) = d_tmp; \
} while (FALSE)
#else /* use only 32 bit unsigned values */
#define M_DTOLFP(d, r_ui, r_uf) /* double to l_fp */ \
do { \
double d_tmp; \
if ((d_tmp = (d)) < 0) { \
(r_ui) = (u_int32)(-d_tmp); \
(r_uf) = (u_int32)(-(d_tmp + (double)(r_ui)) * FRAC); \
M_NEG((r_ui), (r_uf)); \
} else { \
(r_ui) = (u_int32)d_tmp; \
(r_uf) = (u_int32)((d_tmp - (double)(r_ui)) * FRAC); \
} \
} while (0)
#define M_LFPTOD(r_ui, r_uf, d) /* l_fp to double */ \
do { \
u_int32 l_thi, l_tlo; \
l_thi = (r_ui); l_tlo = (r_uf); \
if (M_ISNEG(l_thi)) { \
M_NEG(l_thi, l_tlo); \
(d) = -((double)l_thi + (double)l_tlo / FRAC); \
} else { \
(d) = (double)l_thi + (double)l_tlo / FRAC; \
} \
} while (0)
#endif
#define DTOLFP(d, v) M_DTOLFP((d), (v)->l_ui, (v)->l_uf)
#define LFPTOD(v, d) M_LFPTOD((v)->l_ui, (v)->l_uf, (d))
/*
* Prototypes
*/
extern char * dofptoa (u_fp, int, short, int);
extern char * dolfptoa (u_int32, u_int32, int, short, int);
extern int atolfp (const char *, l_fp *);
extern int buftvtots (const char *, l_fp *);
extern char * fptoa (s_fp, short);
extern char * fptoms (s_fp, short);
extern int hextolfp (const char *, l_fp *);
extern void gpstolfp (u_int, u_int, unsigned long, l_fp *);
extern int mstolfp (const char *, l_fp *);
extern char * prettydate (l_fp *);
extern char * gmprettydate (l_fp *);
extern char * uglydate (l_fp *);
extern void mfp_mul (int32 *, u_int32 *, int32, u_int32, int32, u_int32);
extern void set_sys_fuzz (double);
extern void init_systime (void);
extern void get_systime (l_fp *);
extern int step_systime (double);
extern int adj_systime (double);
extern struct tm * ntp2unix_tm (u_int32 ntp, int local);
#define lfptoa(fpv, ndec) mfptoa((fpv)->l_ui, (fpv)->l_uf, (ndec))
#define lfptoms(fpv, ndec) mfptoms((fpv)->l_ui, (fpv)->l_uf, (ndec))
#define stoa(addr) socktoa(addr)
#define ntoa(addr) stoa(addr)
#define sptoa(addr) sockporttoa(addr)
#define stohost(addr) socktohost(addr)
#define ufptoa(fpv, ndec) dofptoa((fpv), 0, (ndec), 0)
#define ufptoms(fpv, ndec) dofptoa((fpv), 0, (ndec), 1)
#define ulfptoa(fpv, ndec) dolfptoa((fpv)->l_ui, (fpv)->l_uf, 0, (ndec), 0)
#define ulfptoms(fpv, ndec) dolfptoa((fpv)->l_ui, (fpv)->l_uf, 0, (ndec), 1)
#define umfptoa(fpi, fpf, ndec) dolfptoa((fpi), (fpf), 0, (ndec), 0)
/*
* Optional callback from libntp step_systime() to ntpd. Optional
* because other libntp clients like ntpdate don't use it.
*/
typedef void (*time_stepped_callback)(void);
extern time_stepped_callback step_callback;
/*
* Multi-thread locking for get_systime()
*
* On most systems, get_systime() is used solely by the main ntpd
* thread, but on Windows it's also used by the dedicated I/O thread.
* The [Bug 2037] changes to get_systime() have it keep state between
* calls to ensure time moves in only one direction, which means its
* use on Windows needs to be protected against simultaneous execution
* to avoid falsely detecting Lamport violations by ensuring only one
* thread at a time is in get_systime().
*/
#ifdef SYS_WINNT
extern CRITICAL_SECTION get_systime_cs;
# define INIT_GET_SYSTIME_CRITSEC() \
InitializeCriticalSection(&get_systime_cs)
# define ENTER_GET_SYSTIME_CRITSEC() \
EnterCriticalSection(&get_systime_cs)
# define LEAVE_GET_SYSTIME_CRITSEC() \
LeaveCriticalSection(&get_systime_cs)
# define INIT_WIN_PRECISE_TIME() \
init_win_precise_time()
#else /* !SYS_WINNT follows */
# define INIT_GET_SYSTIME_CRITSEC() \
do {} while (FALSE)
# define ENTER_GET_SYSTIME_CRITSEC() \
do {} while (FALSE)
# define LEAVE_GET_SYSTIME_CRITSEC() \
do {} while (FALSE)
# define INIT_WIN_PRECISE_TIME() \
do {} while (FALSE)
#endif
#endif /* NTP_FP_H */