1 /* 2 * ntp_fp.h - definitions for NTP fixed/floating-point arithmetic 3 */ 4 5 #ifndef NTP_FP_H 6 #define NTP_FP_H 7 8 #include <sys/types.h> 9 #include <sys/socket.h> 10 #include <netinet/in.h> 11 12 #include "ntp_types.h" 13 14 /* 15 * NTP uses two fixed point formats. The first (l_fp) is the "long" 16 * format and is 64 bits long with the decimal between bits 31 and 32. 17 * This is used for time stamps in the NTP packet header (in network 18 * byte order) and for internal computations of offsets (in local host 19 * byte order). We use the same structure for both signed and unsigned 20 * values, which is a big hack but saves rewriting all the operators 21 * twice. Just to confuse this, we also sometimes just carry the 22 * fractional part in calculations, in both signed and unsigned forms. 23 * Anyway, an l_fp looks like: 24 * 25 * 0 1 2 3 26 * 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 27 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 28 * | Integral Part | 29 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 30 * | Fractional Part | 31 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 32 * 33 */ 34 typedef struct { 35 union { 36 u_int32 Xl_ui; 37 int32 Xl_i; 38 } Ul_i; 39 union { 40 u_int32 Xl_uf; 41 int32 Xl_f; 42 } Ul_f; 43 } l_fp; 44 45 #define l_ui Ul_i.Xl_ui /* unsigned integral part */ 46 #define l_i Ul_i.Xl_i /* signed integral part */ 47 #define l_uf Ul_f.Xl_uf /* unsigned fractional part */ 48 #define l_f Ul_f.Xl_f /* signed fractional part */ 49 50 /* 51 * Fractional precision (of an l_fp) is actually the number of 52 * bits in a long. 53 */ 54 #define FRACTION_PREC (32) 55 56 57 /* 58 * The second fixed point format is 32 bits, with the decimal between 59 * bits 15 and 16. There is a signed version (s_fp) and an unsigned 60 * version (u_fp). This is used to represent synchronizing distance 61 * and synchronizing dispersion in the NTP packet header (again, in 62 * network byte order) and internally to hold both distance and 63 * dispersion values (in local byte order). In network byte order 64 * it looks like: 65 * 66 * 0 1 2 3 67 * 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 68 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 69 * | Integer Part | Fraction Part | 70 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 71 * 72 */ 73 typedef int32 s_fp; 74 typedef u_int32 u_fp; 75 76 /* 77 * A unit second in fp format. Actually 2**(half_the_bits_in_a_long) 78 */ 79 #define FP_SECOND (0x10000) 80 81 /* 82 * Byte order conversions 83 */ 84 #define HTONS_FP(x) (htonl(x)) 85 #define HTONL_FP(h, n) do { (n)->l_ui = htonl((h)->l_ui); \ 86 (n)->l_uf = htonl((h)->l_uf); } while (0) 87 #define NTOHS_FP(x) (ntohl(x)) 88 #define NTOHL_FP(n, h) do { (h)->l_ui = ntohl((n)->l_ui); \ 89 (h)->l_uf = ntohl((n)->l_uf); } while (0) 90 #define NTOHL_MFP(ni, nf, hi, hf) \ 91 do { (hi) = ntohl(ni); (hf) = ntohl(nf); } while (0) 92 #define HTONL_MFP(hi, hf, ni, nf) \ 93 do { (ni) = ntohl(hi); (nf) = ntohl(hf); } while (0) 94 95 /* funny ones. Converts ts fractions to net order ts */ 96 #define HTONL_UF(uf, nts) \ 97 do { (nts)->l_ui = 0; (nts)->l_uf = htonl(uf); } while (0) 98 #define HTONL_F(f, nts) do { (nts)->l_uf = htonl(f); \ 99 if ((f) & 0x80000000) \ 100 (nts)->l_i = -1; \ 101 else \ 102 (nts)->l_i = 0; \ 103 } while (0) 104 105 /* 106 * Conversions between the two fixed point types 107 */ 108 #define MFPTOFP(x_i, x_f) (((x_i) >= 0x00010000) ? 0x7fffffff : \ 109 (((x_i) <= -0x00010000) ? 0x80000000 : \ 110 (((x_i)<<16) | (((x_f)>>16)&0xffff)))) 111 #define LFPTOFP(v) MFPTOFP((v)->l_i, (v)->l_f) 112 113 #define UFPTOLFP(x, v) ((v)->l_ui = (u_fp)(x)>>16, (v)->l_uf = (x)<<16) 114 #define FPTOLFP(x, v) (UFPTOLFP((x), (v)), (x) < 0 ? (v)->l_ui -= 0x10000 : 0) 115 116 #define MAXLFP(v) ((v)->l_ui = 0x7fffffff, (v)->l_uf = 0xffffffff) 117 #define MINLFP(v) ((v)->l_ui = 0x80000000, (v)->l_uf = 0) 118 119 /* 120 * Primitive operations on long fixed point values. If these are 121 * reminiscent of assembler op codes it's only because some may 122 * be replaced by inline assembler for particular machines someday. 123 * These are the (kind of inefficient) run-anywhere versions. 124 */ 125 #define M_NEG(v_i, v_f) /* v = -v */ \ 126 do { \ 127 if ((v_f) == 0) \ 128 (v_i) = -((s_fp)(v_i)); \ 129 else { \ 130 (v_f) = -((s_fp)(v_f)); \ 131 (v_i) = ~(v_i); \ 132 } \ 133 } while(0) 134 135 #define M_NEGM(r_i, r_f, a_i, a_f) /* r = -a */ \ 136 do { \ 137 if ((a_f) == 0) { \ 138 (r_f) = 0; \ 139 (r_i) = -(a_i); \ 140 } else { \ 141 (r_f) = -(a_f); \ 142 (r_i) = ~(a_i); \ 143 } \ 144 } while(0) 145 146 #define M_ADD(r_i, r_f, a_i, a_f) /* r += a */ \ 147 do { \ 148 register u_int32 lo_tmp; \ 149 register u_int32 hi_tmp; \ 150 \ 151 lo_tmp = ((r_f) & 0xffff) + ((a_f) & 0xffff); \ 152 hi_tmp = (((r_f) >> 16) & 0xffff) + (((a_f) >> 16) & 0xffff); \ 153 if (lo_tmp & 0x10000) \ 154 hi_tmp++; \ 155 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \ 156 \ 157 (r_i) += (a_i); \ 158 if (hi_tmp & 0x10000) \ 159 (r_i)++; \ 160 } while (0) 161 162 #define M_ADD3(r_ovr, r_i, r_f, a_ovr, a_i, a_f) /* r += a, three word */ \ 163 do { \ 164 register u_int32 lo_tmp; \ 165 register u_int32 hi_tmp; \ 166 \ 167 lo_tmp = ((r_f) & 0xffff) + ((a_f) & 0xffff); \ 168 hi_tmp = (((r_f) >> 16) & 0xffff) + (((a_f) >> 16) & 0xffff); \ 169 if (lo_tmp & 0x10000) \ 170 hi_tmp++; \ 171 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \ 172 \ 173 lo_tmp = ((r_i) & 0xffff) + ((a_i) & 0xffff); \ 174 if (hi_tmp & 0x10000) \ 175 lo_tmp++; \ 176 hi_tmp = (((r_i) >> 16) & 0xffff) + (((a_i) >> 16) & 0xffff); \ 177 if (lo_tmp & 0x10000) \ 178 hi_tmp++; \ 179 (r_i) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \ 180 \ 181 (r_ovr) += (a_ovr); \ 182 if (hi_tmp & 0x10000) \ 183 (r_ovr)++; \ 184 } while (0) 185 186 #define M_SUB(r_i, r_f, a_i, a_f) /* r -= a */ \ 187 do { \ 188 register u_int32 lo_tmp; \ 189 register u_int32 hi_tmp; \ 190 \ 191 if ((a_f) == 0) { \ 192 (r_i) -= (a_i); \ 193 } else { \ 194 lo_tmp = ((r_f) & 0xffff) + ((-((s_fp)(a_f))) & 0xffff); \ 195 hi_tmp = (((r_f) >> 16) & 0xffff) \ 196 + (((-((s_fp)(a_f))) >> 16) & 0xffff); \ 197 if (lo_tmp & 0x10000) \ 198 hi_tmp++; \ 199 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \ 200 \ 201 (r_i) += ~(a_i); \ 202 if (hi_tmp & 0x10000) \ 203 (r_i)++; \ 204 } \ 205 } while (0) 206 207 #define M_RSHIFTU(v_i, v_f) /* v >>= 1, v is unsigned */ \ 208 do { \ 209 (v_f) = (u_int32)(v_f) >> 1; \ 210 if ((v_i) & 01) \ 211 (v_f) |= 0x80000000; \ 212 (v_i) = (u_int32)(v_i) >> 1; \ 213 } while (0) 214 215 #define M_RSHIFT(v_i, v_f) /* v >>= 1, v is signed */ \ 216 do { \ 217 (v_f) = (u_int32)(v_f) >> 1; \ 218 if ((v_i) & 01) \ 219 (v_f) |= 0x80000000; \ 220 if ((v_i) & 0x80000000) \ 221 (v_i) = ((v_i) >> 1) | 0x80000000; \ 222 else \ 223 (v_i) = (v_i) >> 1; \ 224 } while (0) 225 226 #define M_LSHIFT(v_i, v_f) /* v <<= 1 */ \ 227 do { \ 228 (v_i) <<= 1; \ 229 if ((v_f) & 0x80000000) \ 230 (v_i) |= 0x1; \ 231 (v_f) <<= 1; \ 232 } while (0) 233 234 #define M_LSHIFT3(v_ovr, v_i, v_f) /* v <<= 1, with overflow */ \ 235 do { \ 236 (v_ovr) <<= 1; \ 237 if ((v_i) & 0x80000000) \ 238 (v_ovr) |= 0x1; \ 239 (v_i) <<= 1; \ 240 if ((v_f) & 0x80000000) \ 241 (v_i) |= 0x1; \ 242 (v_f) <<= 1; \ 243 } while (0) 244 245 #define M_ADDUF(r_i, r_f, uf) /* r += uf, uf is u_int32 fraction */ \ 246 M_ADD((r_i), (r_f), 0, (uf)) /* let optimizer worry about it */ 247 248 #define M_SUBUF(r_i, r_f, uf) /* r -= uf, uf is u_int32 fraction */ \ 249 M_SUB((r_i), (r_f), 0, (uf)) /* let optimizer worry about it */ 250 251 #define M_ADDF(r_i, r_f, f) /* r += f, f is a int32 fraction */ \ 252 do { \ 253 if ((f) > 0) \ 254 M_ADD((r_i), (r_f), 0, (f)); \ 255 else if ((f) < 0) \ 256 M_ADD((r_i), (r_f), (-1), (f));\ 257 } while(0) 258 259 #define M_ISNEG(v_i, v_f) /* v < 0 */ \ 260 (((v_i) & 0x80000000) != 0) 261 262 #define M_ISHIS(a_i, a_f, b_i, b_f) /* a >= b unsigned */ \ 263 (((u_int32)(a_i)) > ((u_int32)(b_i)) || \ 264 ((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f)))) 265 266 #define M_ISGEQ(a_i, a_f, b_i, b_f) /* a >= b signed */ \ 267 (((int32)(a_i)) > ((int32)(b_i)) || \ 268 ((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f)))) 269 270 #define M_ISEQU(a_i, a_f, b_i, b_f) /* a == b unsigned */ \ 271 ((a_i) == (b_i) && (a_f) == (b_f)) 272 273 /* 274 * Operations on the long fp format 275 */ 276 #define L_ADD(r, a) M_ADD((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf) 277 #define L_SUB(r, a) M_SUB((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf) 278 #define L_NEG(v) M_NEG((v)->l_ui, (v)->l_uf) 279 #define L_ADDUF(r, uf) M_ADDUF((r)->l_ui, (r)->l_uf, (uf)) 280 #define L_SUBUF(r, uf) M_SUBUF((r)->l_ui, (r)->l_uf, (uf)) 281 #define L_ADDF(r, f) M_ADDF((r)->l_ui, (r)->l_uf, (f)) 282 #define L_RSHIFT(v) M_RSHIFT((v)->l_i, (v)->l_uf) 283 #define L_RSHIFTU(v) M_RSHIFT((v)->l_ui, (v)->l_uf) 284 #define L_LSHIFT(v) M_LSHIFT((v)->l_ui, (v)->l_uf) 285 #define L_CLR(v) ((v)->l_ui = (v)->l_uf = 0) 286 287 #define L_ISNEG(v) (((v)->l_ui & 0x80000000) != 0) 288 #define L_ISZERO(v) ((v)->l_ui == 0 && (v)->l_uf == 0) 289 #define L_ISHIS(a, b) ((a)->l_ui > (b)->l_ui || \ 290 ((a)->l_ui == (b)->l_ui && (a)->l_uf >= (b)->l_uf)) 291 #define L_ISGEQ(a, b) ((a)->l_i > (b)->l_i || \ 292 ((a)->l_i == (b)->l_i && (a)->l_uf >= (b)->l_uf)) 293 #define L_ISEQU(a, b) M_ISEQU((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf) 294 295 /* 296 * s_fp/double and u_fp/double conversions 297 */ 298 #define FRIC 65536. /* 2^16 as a double */ 299 #define DTOFP(r) ((s_fp)((r) * FRIC)) 300 #define DTOUFP(r) ((u_fp)((r) * FRIC)) 301 #define FPTOD(r) ((double)(r) / FRIC) 302 303 /* 304 * l_fp/double conversions 305 */ 306 #define FRAC 4294967296. /* 2^32 as a double */ 307 #define M_DTOLFP(d, r_i, r_uf) /* double to l_fp */ \ 308 do { \ 309 register double d_tmp; \ 310 \ 311 d_tmp = (d); \ 312 if (d_tmp < 0) { \ 313 d_tmp = -d_tmp; \ 314 (r_i) = (int32)(d_tmp); \ 315 (r_uf) = (u_int32)(((d_tmp) - (double)(r_i)) * FRAC); \ 316 M_NEG((r_i), (r_uf)); \ 317 } else { \ 318 (r_i) = (int32)(d_tmp); \ 319 (r_uf) = (u_int32)(((d_tmp) - (double)(r_i)) * FRAC); \ 320 } \ 321 } while (0) 322 #define M_LFPTOD(r_i, r_uf, d) /* l_fp to double */ \ 323 do { \ 324 register l_fp l_tmp; \ 325 \ 326 l_tmp.l_i = (r_i); \ 327 l_tmp.l_f = (r_uf); \ 328 if (l_tmp.l_i < 0) { \ 329 M_NEG(l_tmp.l_i, l_tmp.l_uf); \ 330 (d) = -((double)l_tmp.l_i + ((double)l_tmp.l_uf) / FRAC); \ 331 } else { \ 332 (d) = (double)l_tmp.l_i + ((double)l_tmp.l_uf) / FRAC; \ 333 } \ 334 } while (0) 335 #define DTOLFP(d, v) M_DTOLFP((d), (v)->l_ui, (v)->l_uf) 336 #define LFPTOD(v, d) M_LFPTOD((v)->l_ui, (v)->l_uf, (d)) 337 338 /* 339 * Prototypes 340 */ 341 extern char * dofptoa P((u_fp, int, int, int)); 342 extern char * dolfptoa P((u_long, u_long, int, int, int)); 343 344 extern int atolfp P((const char *, l_fp *)); 345 extern int buftvtots P((const char *, l_fp *)); 346 extern char * fptoa P((s_fp, int)); 347 extern char * fptoms P((s_fp, int)); 348 extern char * fptoms P((s_fp, int)); 349 extern int hextolfp P((const char *, l_fp *)); 350 extern void gpstolfp P((int, int, unsigned long, l_fp *)); 351 extern int mstolfp P((const char *, l_fp *)); 352 extern char * prettydate P((l_fp *)); 353 extern char * gmprettydate P((l_fp *)); 354 extern char * uglydate P((l_fp *)); 355 extern void mfp_mul P((int32 *, u_int32 *, int32, u_int32, int32, u_int32)); 356 357 extern void get_systime P((l_fp *)); 358 extern int step_systime P((double)); 359 extern int adj_systime P((double)); 360 361 #define lfptoa(_fpv, _ndec) mfptoa((_fpv)->l_ui, (_fpv)->l_uf, (_ndec)) 362 #define lfptoms(_fpv, _ndec) mfptoms((_fpv)->l_ui, (_fpv)->l_uf, (_ndec)) 363 364 #define ntoa(_sin) numtoa((_sin)->sin_addr.s_addr) 365 #define ntohost(_sin) numtohost((_sin)->sin_addr.s_addr) 366 367 #define ufptoa(_fpv, _ndec) dofptoa((_fpv), 0, (_ndec), 0) 368 #define ufptoms(_fpv, _ndec) dofptoa((_fpv), 0, (_ndec), 1) 369 #define ulfptoa(_fpv, _ndec) dolfptoa((_fpv)->l_ui, (_fpv)->l_uf, 0, (_ndec), 0) 370 #define ulfptoms(_fpv, _ndec) dolfptoa((_fpv)->l_ui, (_fpv)->l_uf, 0, (_ndec), 1) 371 #define umfptoa(_fpi, _fpf, _ndec) dolfptoa((_fpi), (_fpf), 0, (_ndec), 0) 372 373 #endif /* NTP_FP_H */ 374