kern_ntptime.c revision 1.17
1 /* $NetBSD: kern_ntptime.c,v 1.17 2001/12/09 16:10:43 manu 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 52 #include <sys/cdefs.h> 53 __KERNEL_RCSID(0, "$NetBSD: kern_ntptime.c,v 1.17 2001/12/09 16:10:43 manu Exp $"); 54 55 #include "opt_ntp.h" 56 57 #include <sys/param.h> 58 #include <sys/resourcevar.h> 59 #include <sys/systm.h> 60 #include <sys/kernel.h> 61 #include <sys/proc.h> 62 #include <sys/timex.h> 63 #include <sys/vnode.h> 64 65 #include <sys/mount.h> 66 #include <sys/syscallargs.h> 67 68 #include <machine/cpu.h> 69 70 #include <uvm/uvm_extern.h> 71 #include <sys/sysctl.h> 72 73 #ifdef NTP 74 75 /* 76 * The following variables are used by the hardclock() routine in the 77 * kern_clock.c module and are described in that module. 78 */ 79 extern int time_state; /* clock state */ 80 extern int time_status; /* clock status bits */ 81 extern long time_offset; /* time adjustment (us) */ 82 extern long time_freq; /* frequency offset (scaled ppm) */ 83 extern long time_maxerror; /* maximum error (us) */ 84 extern long time_esterror; /* estimated error (us) */ 85 extern long time_constant; /* pll time constant */ 86 extern long time_precision; /* clock precision (us) */ 87 extern long time_tolerance; /* frequency tolerance (scaled ppm) */ 88 89 #ifdef PPS_SYNC 90 /* 91 * The following variables are used only if the PPS signal discipline 92 * is configured in the kernel. 93 */ 94 extern int pps_shift; /* interval duration (s) (shift) */ 95 extern long pps_freq; /* pps frequency offset (scaled ppm) */ 96 extern long pps_jitter; /* pps jitter (us) */ 97 extern long pps_stabil; /* pps stability (scaled ppm) */ 98 extern long pps_jitcnt; /* jitter limit exceeded */ 99 extern long pps_calcnt; /* calibration intervals */ 100 extern long pps_errcnt; /* calibration errors */ 101 extern long pps_stbcnt; /* stability limit exceeded */ 102 #endif /* PPS_SYNC */ 103 104 105 106 /*ARGSUSED*/ 107 /* 108 * ntp_gettime() - NTP user application interface 109 */ 110 int 111 sys_ntp_gettime(p, v, retval) 112 struct proc *p; 113 void *v; 114 register_t *retval; 115 116 { 117 struct sys_ntp_gettime_args /* { 118 syscallarg(struct ntptimeval *) ntvp; 119 } */ *uap = v; 120 struct timeval atv; 121 struct ntptimeval ntv; 122 int error = 0; 123 int s; 124 125 if (SCARG(uap, ntvp)) { 126 s = splclock(); 127 #ifdef EXT_CLOCK 128 /* 129 * The microtime() external clock routine returns a 130 * status code. If less than zero, we declare an error 131 * in the clock status word and return the kernel 132 * (software) time variable. While there are other 133 * places that call microtime(), this is the only place 134 * that matters from an application point of view. 135 */ 136 if (microtime(&atv) < 0) { 137 time_status |= STA_CLOCKERR; 138 ntv.time = time; 139 } else 140 time_status &= ~STA_CLOCKERR; 141 #else /* EXT_CLOCK */ 142 microtime(&atv); 143 #endif /* EXT_CLOCK */ 144 ntv.time = atv; 145 ntv.maxerror = time_maxerror; 146 ntv.esterror = time_esterror; 147 (void) splx(s); 148 149 error = copyout((caddr_t)&ntv, (caddr_t)SCARG(uap, ntvp), 150 sizeof(ntv)); 151 } 152 if (!error) { 153 154 /* 155 * Status word error decode. If any of these conditions 156 * occur, an error is returned, instead of the status 157 * word. Most applications will care only about the fact 158 * the system clock may not be trusted, not about the 159 * details. 160 * 161 * Hardware or software error 162 */ 163 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 164 165 /* 166 * PPS signal lost when either time or frequency 167 * synchronization requested 168 */ 169 (time_status & (STA_PPSFREQ | STA_PPSTIME) && 170 !(time_status & STA_PPSSIGNAL)) || 171 172 /* 173 * PPS jitter exceeded when time synchronization 174 * requested 175 */ 176 (time_status & STA_PPSTIME && 177 time_status & STA_PPSJITTER) || 178 179 /* 180 * PPS wander exceeded or calibration error when 181 * frequency synchronization requested 182 */ 183 (time_status & STA_PPSFREQ && 184 time_status & (STA_PPSWANDER | STA_PPSERROR))) 185 *retval = TIME_ERROR; 186 else 187 *retval = (register_t)time_state; 188 } 189 return(error); 190 } 191 192 193 /* ARGSUSED */ 194 /* 195 * ntp_adjtime() - NTP daemon application interface 196 */ 197 int 198 sys_ntp_adjtime(p, v, retval) 199 struct proc *p; 200 void *v; 201 register_t *retval; 202 { 203 struct sys_ntp_adjtime_args /* { 204 syscallarg(struct timex *) tp; 205 } */ *uap = v; 206 struct timex ntv; 207 int error = 0; 208 209 if ((error = copyin((caddr_t)SCARG(uap, tp), (caddr_t)&ntv, 210 sizeof(ntv))) != 0) 211 return (error); 212 213 if (ntv.modes != 0 && (error = suser(p->p_ucred, &p->p_acflag)) != 0) 214 return (error); 215 216 return (ntp_adjtime1(&ntv, v, retval)); 217 } 218 219 int 220 ntp_adjtime1(ntv, v, retval) 221 struct timex *ntv; 222 void *v; 223 register_t *retval; 224 { 225 struct sys_ntp_adjtime_args /* { 226 syscallarg(struct timex *) tp; 227 } */ *uap = v; 228 int error = 0; 229 int modes; 230 int s; 231 232 /* 233 * Update selected clock variables. Note that there is no error 234 * checking here on the assumption the superuser should know 235 * what it is doing. 236 */ 237 modes = ntv->modes; 238 s = splclock(); 239 if (modes & MOD_FREQUENCY) 240 #ifdef PPS_SYNC 241 time_freq = ntv->freq - pps_freq; 242 #else /* PPS_SYNC */ 243 time_freq = ntv->freq; 244 #endif /* PPS_SYNC */ 245 if (modes & MOD_MAXERROR) 246 time_maxerror = ntv->maxerror; 247 if (modes & MOD_ESTERROR) 248 time_esterror = ntv->esterror; 249 if (modes & MOD_STATUS) { 250 time_status &= STA_RONLY; 251 time_status |= ntv->status & ~STA_RONLY; 252 } 253 if (modes & MOD_TIMECONST) 254 time_constant = ntv->constant; 255 if (modes & MOD_OFFSET) 256 hardupdate(ntv->offset); 257 258 /* 259 * Retrieve all clock variables 260 */ 261 if (time_offset < 0) 262 ntv->offset = -(-time_offset >> SHIFT_UPDATE); 263 else 264 ntv->offset = time_offset >> SHIFT_UPDATE; 265 #ifdef PPS_SYNC 266 ntv->freq = time_freq + pps_freq; 267 #else /* PPS_SYNC */ 268 ntv->freq = time_freq; 269 #endif /* PPS_SYNC */ 270 ntv->maxerror = time_maxerror; 271 ntv->esterror = time_esterror; 272 ntv->status = time_status; 273 ntv->constant = time_constant; 274 ntv->precision = time_precision; 275 ntv->tolerance = time_tolerance; 276 #ifdef PPS_SYNC 277 ntv->shift = pps_shift; 278 ntv->ppsfreq = pps_freq; 279 ntv->jitter = pps_jitter >> PPS_AVG; 280 ntv->stabil = pps_stabil; 281 ntv->calcnt = pps_calcnt; 282 ntv->errcnt = pps_errcnt; 283 ntv->jitcnt = pps_jitcnt; 284 ntv->stbcnt = pps_stbcnt; 285 #endif /* PPS_SYNC */ 286 (void)splx(s); 287 288 error = copyout((caddr_t)ntv, (caddr_t)SCARG(uap, tp), sizeof(*ntv)); 289 if (!error) { 290 291 /* 292 * Status word error decode. See comments in 293 * ntp_gettime() routine. 294 */ 295 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 296 (time_status & (STA_PPSFREQ | STA_PPSTIME) && 297 !(time_status & STA_PPSSIGNAL)) || 298 (time_status & STA_PPSTIME && 299 time_status & STA_PPSJITTER) || 300 (time_status & STA_PPSFREQ && 301 time_status & (STA_PPSWANDER | STA_PPSERROR))) 302 *retval = TIME_ERROR; 303 else 304 *retval = (register_t)time_state; 305 } 306 return error; 307 } 308 309 310 311 /* 312 * return information about kernel precision timekeeping 313 */ 314 int 315 sysctl_ntptime(where, sizep) 316 void *where; 317 size_t *sizep; 318 { 319 struct timeval atv; 320 struct ntptimeval ntv; 321 int s; 322 323 /* 324 * Construct ntp_timeval. 325 */ 326 327 s = splclock(); 328 #ifdef EXT_CLOCK 329 /* 330 * The microtime() external clock routine returns a 331 * status code. If less than zero, we declare an error 332 * in the clock status word and return the kernel 333 * (software) time variable. While there are other 334 * places that call microtime(), this is the only place 335 * that matters from an application point of view. 336 */ 337 if (microtime(&atv) < 0) { 338 time_status |= STA_CLOCKERR; 339 ntv.time = time; 340 } else { 341 time_status &= ~STA_CLOCKERR; 342 } 343 #else /* EXT_CLOCK */ 344 microtime(&atv); 345 #endif /* EXT_CLOCK */ 346 ntv.time = atv; 347 ntv.maxerror = time_maxerror; 348 ntv.esterror = time_esterror; 349 splx(s); 350 351 #ifdef notyet 352 /* 353 * Status word error decode. If any of these conditions 354 * occur, an error is returned, instead of the status 355 * word. Most applications will care only about the fact 356 * the system clock may not be trusted, not about the 357 * details. 358 * 359 * Hardware or software error 360 */ 361 if ((time_status & (STA_UNSYNC | STA_CLOCKERR)) || 362 ntv.time_state = TIME_ERROR; 363 364 /* 365 * PPS signal lost when either time or frequency 366 * synchronization requested 367 */ 368 (time_status & (STA_PPSFREQ | STA_PPSTIME) && 369 !(time_status & STA_PPSSIGNAL)) || 370 371 /* 372 * PPS jitter exceeded when time synchronization 373 * requested 374 */ 375 (time_status & STA_PPSTIME && 376 time_status & STA_PPSJITTER) || 377 378 /* 379 * PPS wander exceeded or calibration error when 380 * frequency synchronization requested 381 */ 382 (time_status & STA_PPSFREQ && 383 time_status & (STA_PPSWANDER | STA_PPSERROR))) 384 ntv.time_state = TIME_ERROR; 385 else 386 ntv.time_state = time_state; 387 #endif /* notyet */ 388 return (sysctl_rdstruct(where, sizep, NULL, &ntv, sizeof(ntv))); 389 } 390 391 #else /* !NTP */ 392 393 /* For some reason, raising SIGSYS (as sys_nosys would) is problematic. */ 394 395 int 396 sys_ntp_gettime(p, v, retval) 397 struct proc *p; 398 void *v; 399 register_t *retval; 400 { 401 return(ENOSYS); 402 } 403 404 #endif /* !NTP */ 405
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