kern_ntptime.c revision 1.13.2.2
1 /* $NetBSD: kern_ntptime.c,v 1.13.2.2 2001/09/21 22:36:25 nathanw Exp $ */ 2 3 /****************************************************************************** 4 * * 5 * Copyright (c) David L. Mills 1993, 1994 * 6 * * 7 * Permission to use, copy, modify, and distribute this software and its * 8 * documentation for any purpose and without fee is hereby granted, provided * 9 * that the above copyright notice appears in all copies and that both the * 10 * copyright notice and this permission notice appear in supporting * 11 * documentation, and that the name University of Delaware not be used in * 12 * advertising or publicity pertaining to distribution of the software * 13 * without specific, written prior permission. The University of Delaware * 14 * makes no representations about the suitability this software for any * 15 * purpose. It is provided "as is" without express or implied warranty. * 16 * * 17 ******************************************************************************/ 18 19 /* 20 * Modification history kern_ntptime.c 21 * 22 * 24 Sep 94 David L. Mills 23 * Tightened code at exits. 24 * 25 * 24 Mar 94 David L. Mills 26 * Revised syscall interface to include new variables for PPS 27 * time discipline. 28 * 29 * 14 Feb 94 David L. Mills 30 * Added code for external clock 31 * 32 * 28 Nov 93 David L. Mills 33 * Revised frequency scaling to conform with adjusted parameters 34 * 35 * 17 Sep 93 David L. Mills 36 * Created file 37 */ 38 /* 39 * ntp_gettime(), ntp_adjtime() - precision time interface for SunOS 40 * V4.1.1 and V4.1.3 41 * 42 * These routines consitute the Network Time Protocol (NTP) interfaces 43 * for user and daemon application programs. The ntp_gettime() routine 44 * provides the time, maximum error (synch distance) and estimated error 45 * (dispersion) to client user application programs. The ntp_adjtime() 46 * routine is used by the NTP daemon to adjust the system clock to an 47 * externally derived time. The time offset and related variables set by 48 * this routine are used by hardclock() to adjust the phase and 49 * frequency of the phase-lock loop which controls the system clock. 50 */ 51 #include "opt_ntp.h" 52 53 #include <sys/param.h> 54 #include <sys/resourcevar.h> 55 #include <sys/systm.h> 56 #include <sys/kernel.h> 57 #include <sys/lwp.h> 58 #include <sys/proc.h> 59 #include <sys/timex.h> 60 #include <sys/vnode.h> 61 62 #include <sys/mount.h> 63 #include <sys/syscallargs.h> 64 65 #include <machine/cpu.h> 66 67 #include <uvm/uvm_extern.h> 68 #include <sys/sysctl.h> 69 70 #ifdef NTP 71 72 /* 73 * The following variables are used by the hardclock() routine in the 74 * kern_clock.c module and are described in that module. 75 */ 76 extern int time_state; /* clock state */ 77 extern int time_status; /* clock status bits */ 78 extern long time_offset; /* time adjustment (us) */ 79 extern long time_freq; /* frequency offset (scaled ppm) */ 80 extern long time_maxerror; /* maximum error (us) */ 81 extern long time_esterror; /* estimated error (us) */ 82 extern long time_constant; /* pll time constant */ 83 extern long time_precision; /* clock precision (us) */ 84 extern long time_tolerance; /* frequency tolerance (scaled ppm) */ 85 86 #ifdef PPS_SYNC 87 /* 88 * The following variables are used only if the PPS signal discipline 89 * is configured in the kernel. 90 */ 91 extern int pps_shift; /* interval duration (s) (shift) */ 92 extern long pps_freq; /* pps frequency offset (scaled ppm) */ 93 extern long pps_jitter; /* pps jitter (us) */ 94 extern long pps_stabil; /* pps stability (scaled ppm) */ 95 extern long pps_jitcnt; /* jitter limit exceeded */ 96 extern long pps_calcnt; /* calibration intervals */ 97 extern long pps_errcnt; /* calibration errors */ 98 extern long pps_stbcnt; /* stability limit exceeded */ 99 #endif /* PPS_SYNC */ 100 101 102 103 /*ARGSUSED*/ 104 /* 105 * ntp_gettime() - NTP user application interface 106 */ 107 int 108 sys_ntp_gettime(l, v, retval) 109 struct lwp *l; 110 void *v; 111 register_t *retval; 112 113 { 114 struct sys_ntp_gettime_args /* { 115 syscallarg(struct ntptimeval *) ntvp; 116 } */ *uap = v; 117 struct timeval atv; 118 struct ntptimeval ntv; 119 int error = 0; 120 int s; 121 122 if (SCARG(uap, ntvp)) { 123 s = splclock(); 124 #ifdef EXT_CLOCK 125 /* 126 * The microtime() external clock routine returns a 127 * status code. If less than zero, we declare an error 128 * in the clock status word and return the kernel 129 * (software) time variable. While there are other 130 * places that call microtime(), this is the only place 131 * that matters from an application point of view. 132 */ 133 if (microtime(&atv) < 0) { 134 time_status |= STA_CLOCKERR; 135 ntv.time = time; 136 } else 137 time_status &= ~STA_CLOCKERR; 138 #else /* EXT_CLOCK */ 139 microtime(&atv); 140 #endif /* EXT_CLOCK */ 141 ntv.time = atv; 142 ntv.maxerror = time_maxerror; 143 ntv.esterror = time_esterror; 144 (void) splx(s); 145 146 error = copyout((caddr_t)&ntv, (caddr_t)SCARG(uap, ntvp), 147 sizeof(ntv)); 148 } 149 if (!error) { 150 151 /* 152 * Status word error decode. If any of these conditions 153 * occur, an error is returned, instead of the status 154 * word. Most applications will care only about the fact 155 * the system clock may not be trusted, not about the 156 * details. 157 * 158 * Hardware or software error 159 */ 160 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 161 162 /* 163 * PPS signal lost when either time or frequency 164 * synchronization requested 165 */ 166 (time_status & (STA_PPSFREQ | STA_PPSTIME) && 167 !(time_status & STA_PPSSIGNAL)) || 168 169 /* 170 * PPS jitter exceeded when time synchronization 171 * requested 172 */ 173 (time_status & STA_PPSTIME && 174 time_status & STA_PPSJITTER) || 175 176 /* 177 * PPS wander exceeded or calibration error when 178 * frequency synchronization requested 179 */ 180 (time_status & STA_PPSFREQ && 181 time_status & (STA_PPSWANDER | STA_PPSERROR))) 182 *retval = TIME_ERROR; 183 else 184 *retval = (register_t)time_state; 185 } 186 return(error); 187 } 188 189 190 /* ARGSUSED */ 191 /* 192 * ntp_adjtime() - NTP daemon application interface 193 */ 194 int 195 sys_ntp_adjtime(l, v, retval) 196 struct lwp *l; 197 void *v; 198 register_t *retval; 199 { 200 struct sys_ntp_adjtime_args /* { 201 syscallarg(struct timex *) tp; 202 } */ *uap = v; 203 struct proc *p = l->l_proc; 204 struct timex ntv; 205 int error = 0; 206 207 if ((error = copyin((caddr_t)SCARG(uap, tp), (caddr_t)&ntv, 208 sizeof(ntv))) != 0) 209 return (error); 210 211 212 if (ntv.modes != 0 && (error = suser(p->p_ucred, &p->p_acflag)) != 0) 213 return (error); 214 215 return (ntp_adjtime1(&ntv, v, retval)); 216 } 217 218 int 219 ntp_adjtime1(ntv, v, retval) 220 struct timex *ntv; 221 void *v; 222 register_t *retval; 223 { 224 struct sys_ntp_adjtime_args /* { 225 syscallarg(struct timex *) tp; 226 } */ *uap = v; 227 int error = 0; 228 int modes; 229 int s; 230 231 /* 232 * Update selected clock variables. Note that there is no error 233 * checking here on the assumption the superuser should know 234 * what it is doing. 235 */ 236 modes = ntv->modes; 237 s = splclock(); 238 if (modes & MOD_FREQUENCY) 239 #ifdef PPS_SYNC 240 time_freq = ntv->freq - pps_freq; 241 #else /* PPS_SYNC */ 242 time_freq = ntv->freq; 243 #endif /* PPS_SYNC */ 244 if (modes & MOD_MAXERROR) 245 time_maxerror = ntv->maxerror; 246 if (modes & MOD_ESTERROR) 247 time_esterror = ntv->esterror; 248 if (modes & MOD_STATUS) { 249 time_status &= STA_RONLY; 250 time_status |= ntv->status & ~STA_RONLY; 251 } 252 if (modes & MOD_TIMECONST) 253 time_constant = ntv->constant; 254 if (modes & MOD_OFFSET) 255 hardupdate(ntv->offset); 256 257 /* 258 * Retrieve all clock variables 259 */ 260 if (time_offset < 0) 261 ntv->offset = -(-time_offset >> SHIFT_UPDATE); 262 else 263 ntv->offset = time_offset >> SHIFT_UPDATE; 264 #ifdef PPS_SYNC 265 ntv->freq = time_freq + pps_freq; 266 #else /* PPS_SYNC */ 267 ntv->freq = time_freq; 268 #endif /* PPS_SYNC */ 269 ntv->maxerror = time_maxerror; 270 ntv->esterror = time_esterror; 271 ntv->status = time_status; 272 ntv->constant = time_constant; 273 ntv->precision = time_precision; 274 ntv->tolerance = time_tolerance; 275 #ifdef PPS_SYNC 276 ntv->shift = pps_shift; 277 ntv->ppsfreq = pps_freq; 278 ntv->jitter = pps_jitter >> PPS_AVG; 279 ntv->stabil = pps_stabil; 280 ntv->calcnt = pps_calcnt; 281 ntv->errcnt = pps_errcnt; 282 ntv->jitcnt = pps_jitcnt; 283 ntv->stbcnt = pps_stbcnt; 284 #endif /* PPS_SYNC */ 285 (void)splx(s); 286 287 error = copyout((caddr_t)ntv, (caddr_t)SCARG(uap, tp), sizeof(*ntv)); 288 if (!error) { 289 290 /* 291 * Status word error decode. See comments in 292 * ntp_gettime() routine. 293 */ 294 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 295 (time_status & (STA_PPSFREQ | STA_PPSTIME) && 296 !(time_status & STA_PPSSIGNAL)) || 297 (time_status & STA_PPSTIME && 298 time_status & STA_PPSJITTER) || 299 (time_status & STA_PPSFREQ && 300 time_status & (STA_PPSWANDER | STA_PPSERROR))) 301 *retval = TIME_ERROR; 302 else 303 *retval = (register_t)time_state; 304 } 305 return error; 306 } 307 308 309 310 /* 311 * return information about kernel precision timekeeping 312 */ 313 int 314 sysctl_ntptime(where, sizep) 315 void *where; 316 size_t *sizep; 317 { 318 struct timeval atv; 319 struct ntptimeval ntv; 320 int s; 321 322 /* 323 * Construct ntp_timeval. 324 */ 325 326 s = splclock(); 327 #ifdef EXT_CLOCK 328 /* 329 * The microtime() external clock routine returns a 330 * status code. If less than zero, we declare an error 331 * in the clock status word and return the kernel 332 * (software) time variable. While there are other 333 * places that call microtime(), this is the only place 334 * that matters from an application point of view. 335 */ 336 if (microtime(&atv) < 0) { 337 time_status |= STA_CLOCKERR; 338 ntv.time = time; 339 } else { 340 time_status &= ~STA_CLOCKERR; 341 } 342 #else /* EXT_CLOCK */ 343 microtime(&atv); 344 #endif /* EXT_CLOCK */ 345 ntv.time = atv; 346 ntv.maxerror = time_maxerror; 347 ntv.esterror = time_esterror; 348 splx(s); 349 350 #ifdef notyet 351 /* 352 * Status word error decode. If any of these conditions 353 * occur, an error is returned, instead of the status 354 * word. Most applications will care only about the fact 355 * the system clock may not be trusted, not about the 356 * details. 357 * 358 * Hardware or software error 359 */ 360 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 361 ntv.time_state = TIME_ERROR; 362 363 /* 364 * PPS signal lost when either time or frequency 365 * synchronization requested 366 */ 367 (time_status & (STA_PPSFREQ | STA_PPSTIME) && 368 !(time_status & STA_PPSSIGNAL)) || 369 370 /* 371 * PPS jitter exceeded when time synchronization 372 * requested 373 */ 374 (time_status & STA_PPSTIME && 375 time_status & STA_PPSJITTER) || 376 377 /* 378 * PPS wander exceeded or calibration error when 379 * frequency synchronization requested 380 */ 381 (time_status & STA_PPSFREQ && 382 time_status & (STA_PPSWANDER | STA_PPSERROR))) 383 ntv.time_state = TIME_ERROR; 384 else 385 ntv.time_state = time_state; 386 #endif /* notyet */ 387 return (sysctl_rdstruct(where, sizep, NULL, &ntv, sizeof(ntv))); 388 } 389 390 #else /* !NTP */ 391 392 /* For some reason, raising SIGSYS (as sys_nosys would) is problematic. */ 393 394 int 395 sys_ntp_gettime(l, v, retval) 396 struct lwp *l; 397 void *v; 398 register_t *retval; 399 { 400 return(ENOSYS); 401 } 402 403 #endif /* !NTP */ 404
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