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Diffstat (limited to 'include/ntp_fp.h')
-rw-r--r-- | include/ntp_fp.h | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/include/ntp_fp.h b/include/ntp_fp.h new file mode 100644 index 0000000..1b97e8b --- /dev/null +++ b/include/ntp_fp.h @@ -0,0 +1,420 @@ +/* + * 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. + */ +#if defined(HAVE_U_INT64) && \ + !(defined(__SVR4) && defined(__sun) && \ + defined(sparc) && 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 (int, 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 */ |