1 /* 2 * ntp_filegen.c,v 3.12 1994/01/25 19:06:11 kardel Exp 3 * 4 * implements file generations support for NTP 5 * logfiles and statistic files 6 * 7 * 8 * Copyright (C) 1992, 1996 by Rainer Pruy 9 * Friedrich-Alexander Universit�t Erlangen-N�rnberg, Germany 10 * 11 * This code may be modified and used freely 12 * provided credits remain intact. 13 */ 14 15 #ifdef HAVE_CONFIG_H 16 # include <config.h> 17 #endif 18 19 #include <stdio.h> 20 #include <sys/types.h> 21 #include <sys/stat.h> 22 23 #include "ntpd.h" 24 #include "ntp_io.h" 25 #include "ntp_string.h" 26 #include "ntp_calendar.h" 27 #include "ntp_filegen.h" 28 #include "ntp_stdlib.h" 29 30 /* 31 * NTP is intended to run long periods of time without restart. 32 * Thus log and statistic files generated by NTP will grow large. 33 * 34 * this set of routines provides a central interface 35 * to generating files using file generations 36 * 37 * the generation of a file is changed according to file generation type 38 */ 39 40 41 /* 42 * redefine this if your system dislikes filename suffixes like 43 * X.19910101 or X.1992W50 or .... 44 */ 45 #define SUFFIX_SEP '.' 46 47 /* 48 * other constants 49 */ 50 #define FGEN_AGE_SECS (24*60*60) /* life time of FILEGEN_AGE in seconds */ 51 52 static void filegen_open P((FILEGEN *, u_long)); 53 static int valid_fileref P((char *, char *)); 54 #ifdef UNUSED 55 static FILEGEN *filegen_unregister P((char *)); 56 #endif /* UNUSED */ 57 58 static void filegen_init P((char *, const char *, FILEGEN *)); 59 60 /* 61 * filegen_init 62 */ 63 64 static void 65 filegen_init(char *prefix, const char *basename, FILEGEN *fp) 66 { 67 fp->fp = NULL; 68 fp->prefix = prefix; /* Yes, this is TOTALLY lame! */ 69 fp->basename = (char*)emalloc(strlen(basename) + 1); 70 strcpy(fp->basename, basename); 71 fp->id = 0; 72 fp->type = FILEGEN_DAY; 73 fp->flag = FGEN_FLAG_LINK; /* not yet enabled !!*/ 74 } 75 76 77 /* 78 * open a file generation according to the current settings of gen 79 * will also provide a link to basename if requested to do so 80 */ 81 82 static void 83 filegen_open( 84 FILEGEN *gen, 85 u_long newid 86 ) 87 { 88 char *filename; 89 char *basename; 90 u_int len; 91 FILE *fp; 92 struct calendar cal; 93 94 len = strlen(gen->prefix) + strlen(gen->basename) + 1; 95 basename = (char*)emalloc(len); 96 sprintf(basename, "%s%s", gen->prefix, gen->basename); 97 98 switch(gen->type) { 99 default: 100 msyslog(LOG_ERR, "unsupported file generations type %d for \"%s\" - reverting to FILEGEN_NONE", 101 gen->type, basename); 102 gen->type = FILEGEN_NONE; 103 104 /*FALLTHROUGH*/ 105 case FILEGEN_NONE: 106 filename = (char*)emalloc(len); 107 sprintf(filename,"%s", basename); 108 break; 109 110 case FILEGEN_PID: 111 filename = (char*)emalloc(len + 1 + 1 + 10); 112 sprintf(filename,"%s%c#%ld", basename, SUFFIX_SEP, newid); 113 break; 114 115 case FILEGEN_DAY: 116 /* You can argue here in favor of using MJD, but 117 * I would assume it to be easier for humans to interpret dates 118 * in a format they are used to in everyday life. 119 */ 120 caljulian(newid,&cal); 121 filename = (char*)emalloc(len + 1 + 4 + 2 + 2); 122 sprintf(filename, "%s%c%04d%02d%02d", 123 basename, SUFFIX_SEP, cal.year, cal.month, cal.monthday); 124 break; 125 126 case FILEGEN_WEEK: 127 /* 128 * This is still a hack 129 * - the term week is not correlated to week as it is used 130 * normally - it just refers to a period of 7 days 131 * starting at Jan 1 - 'weeks' are counted starting from zero 132 */ 133 caljulian(newid,&cal); 134 filename = (char*)emalloc(len + 1 + 4 + 1 + 2); 135 sprintf(filename, "%s%c%04dw%02d", 136 basename, SUFFIX_SEP, cal.year, cal.yearday / 7); 137 break; 138 139 case FILEGEN_MONTH: 140 caljulian(newid,&cal); 141 filename = (char*)emalloc(len + 1 + 4 + 2); 142 sprintf(filename, "%s%c%04d%02d", 143 basename, SUFFIX_SEP, cal.year, cal.month); 144 break; 145 146 case FILEGEN_YEAR: 147 caljulian(newid,&cal); 148 filename = (char*)emalloc(len + 1 + 4); 149 sprintf(filename, "%s%c%04d", basename, SUFFIX_SEP, cal.year); 150 break; 151 152 case FILEGEN_AGE: 153 filename = (char*)emalloc(len + 1 + 2 + 10); 154 sprintf(filename, "%s%ca%08ld", basename, SUFFIX_SEP, newid); 155 break; 156 } 157 158 if (gen->type != FILEGEN_NONE) { 159 /* 160 * check for existence of a file with name 'basename' 161 * as we disallow such a file 162 * if FGEN_FLAG_LINK is set create a link 163 */ 164 struct stat stats; 165 /* 166 * try to resolve name collisions 167 */ 168 static u_long conflicts = 0; 169 170 #ifndef S_ISREG 171 #define S_ISREG(mode) (((mode) & S_IFREG) == S_IFREG) 172 #endif 173 if (stat(basename, &stats) == 0) { 174 /* Hm, file exists... */ 175 if (S_ISREG(stats.st_mode)) { 176 if (stats.st_nlink <= 1) { 177 /* 178 * Oh, it is not linked - try to save it 179 */ 180 char *savename = (char*)emalloc(len + 1 + 1 + 10 + 10); 181 sprintf(savename, "%s%c%dC%lu", 182 basename, 183 SUFFIX_SEP, 184 (int) getpid(), 185 (u_long)conflicts++); 186 if (rename(basename, savename) != 0) 187 msyslog(LOG_ERR," couldn't save %s: %m", basename); 188 free(savename); 189 } else { 190 /* 191 * there is at least a second link to 192 * this file. 193 * just remove the conflicting one 194 */ 195 if ( 196 #if !defined(VMS) 197 unlink(basename) != 0 198 #else 199 delete(basename) != 0 200 #endif 201 ) 202 msyslog(LOG_ERR, "couldn't unlink %s: %m", basename); 203 } 204 } else { 205 /* 206 * Ehh? Not a regular file ?? strange !!!! 207 */ 208 msyslog(LOG_ERR, "expected regular file for %s (found mode 0%lo)", 209 basename, (unsigned long)stats.st_mode); 210 } 211 } else { 212 /* 213 * stat(..) failed, but it is absolutely correct for 214 * 'basename' not to exist 215 */ 216 if (errno != ENOENT) 217 msyslog(LOG_ERR,"stat(%s) failed: %m", basename); 218 } 219 } 220 221 /* 222 * now, try to open new file generation... 223 */ 224 fp = fopen(filename, "a"); 225 226 #ifdef DEBUG 227 if (debug > 3) 228 printf("opening filegen (type=%d/id=%lu) \"%s\"\n", 229 gen->type, (u_long)newid, filename); 230 #endif 231 232 if (fp == NULL) { 233 /* open failed -- keep previous state 234 * 235 * If the file was open before keep the previous generation. 236 * This will cause output to end up in the 'wrong' file, 237 * but I think this is still better than losing output 238 * 239 * ignore errors due to missing directories 240 */ 241 242 if (errno != ENOENT) 243 msyslog(LOG_ERR, "can't open %s: %m", filename); 244 } else { 245 if (gen->fp != NULL) { 246 fclose(gen->fp); 247 } 248 gen->fp = fp; 249 gen->id = newid; 250 251 if (gen->flag & FGEN_FLAG_LINK) { 252 /* 253 * need to link file to basename 254 * have to use hardlink for now as I want to allow 255 * gen->basename spanning directory levels 256 * this would make it more complex to get the correct 257 * filename for symlink 258 * 259 * Ok, it would just mean taking the part following 260 * the last '/' in the name.... Should add it later.... 261 */ 262 263 /* Windows NT does not support file links -Greg Schueman 1/18/97 */ 264 265 #if defined SYS_WINNT || defined SYS_VXWORKS 266 SetLastError(0); /* On WinNT, don't support FGEN_FLAG_LINK */ 267 #elif defined(VMS) 268 errno = 0; /* On VMS, don't support FGEN_FLAG_LINK */ 269 #else /* not (VMS) / VXWORKS / WINNT ; DO THE LINK) */ 270 if (link(filename, basename) != 0) 271 if (errno != EEXIST) 272 msyslog(LOG_ERR, "can't link(%s, %s): %m", filename, basename); 273 #endif /* SYS_WINNT || VXWORKS */ 274 } /* flags & FGEN_FLAG_LINK */ 275 } /* else fp == NULL */ 276 277 free(basename); 278 free(filename); 279 return; 280 } 281 282 /* 283 * this function sets up gen->fp to point to the correct 284 * generation of the file for the time specified by 'now' 285 * 286 * 'now' usually is interpreted as second part of a l_fp as is in the cal... 287 * library routines 288 */ 289 290 void 291 filegen_setup( 292 FILEGEN *gen, 293 u_long now 294 ) 295 { 296 u_long new_gen = ~ (u_long) 0; 297 struct calendar cal; 298 299 if (!(gen->flag & FGEN_FLAG_ENABLED)) { 300 if (gen->fp != NULL) 301 fclose(gen->fp); 302 return; 303 } 304 305 switch (gen->type) { 306 case FILEGEN_NONE: 307 if (gen->fp != NULL) return; /* file already open */ 308 break; 309 310 case FILEGEN_PID: 311 new_gen = getpid(); 312 break; 313 314 case FILEGEN_DAY: 315 caljulian(now, &cal); 316 cal.hour = cal.minute = cal.second = 0; 317 new_gen = caltontp(&cal); 318 break; 319 320 case FILEGEN_WEEK: 321 /* Would be nice to have a calweekstart() routine */ 322 /* so just use a hack ... */ 323 /* just round time to integral 7 day period for actual year */ 324 new_gen = now - (now - calyearstart(now)) % TIMES7(SECSPERDAY) 325 + 60; 326 /* 327 * just to be sure - 328 * the computation above would fail in the presence of leap seconds 329 * so at least carry the date to the next day (+60 (seconds)) 330 * and go back to the start of the day via calendar computations 331 */ 332 caljulian(new_gen, &cal); 333 cal.hour = cal.minute = cal.second = 0; 334 new_gen = caltontp(&cal); 335 break; 336 337 case FILEGEN_MONTH: 338 caljulian(now, &cal); 339 cal.yearday = (u_short) (cal.yearday - cal.monthday + 1); 340 cal.monthday = 1; 341 cal.hour = cal.minute = cal.second = 0; 342 new_gen = caltontp(&cal); 343 break; 344 345 case FILEGEN_YEAR: 346 new_gen = calyearstart(now); 347 break; 348 349 case FILEGEN_AGE: 350 new_gen = current_time - (current_time % FGEN_AGE_SECS); 351 break; 352 } 353 /* 354 * try to open file if not yet open 355 * reopen new file generation file on change of generation id 356 */ 357 if (gen->fp == NULL || gen->id != new_gen) { 358 #if DEBUG 359 if (debug) 360 printf("filegen %0x %lu %lu %lu\n", gen->type, now, 361 gen->id, new_gen); 362 #endif 363 filegen_open(gen, new_gen); 364 } 365 } 366 367 368 /* 369 * change settings for filegen files 370 */ 371 void 372 filegen_config( 373 FILEGEN *gen, 374 char *basename, 375 u_int type, 376 u_int flag 377 ) 378 { 379 /* 380 * if nothing would be changed... 381 */ 382 if ((basename == gen->basename || strcmp(basename,gen->basename) == 0) && 383 type == gen->type && 384 flag == gen->flag) 385 return; 386 387 /* 388 * validate parameters 389 */ 390 if (!valid_fileref(gen->prefix,basename)) 391 return; 392 393 if (gen->fp != NULL) 394 fclose(gen->fp); 395 396 #ifdef DEBUG 397 if (debug > 2) 398 printf("configuring filegen:\n\tprefix:\t%s\n\tbasename:\t%s -> %s\n\ttype:\t%d -> %d\n\tflag: %x -> %x\n", 399 gen->prefix, gen->basename, basename, gen->type, type, gen->flag, flag); 400 #endif 401 if (gen->basename != basename || strcmp(gen->basename, basename) != 0) { 402 free(gen->basename); 403 gen->basename = (char*)emalloc(strlen(basename) + 1); 404 strcpy(gen->basename, basename); 405 } 406 gen->type = (u_char) type; 407 gen->flag = (u_char) flag; 408 409 /* 410 * make filegen use the new settings 411 * special action is only required when a generation file 412 * is currently open 413 * otherwise the new settings will be used anyway at the next open 414 */ 415 if (gen->fp != NULL) { 416 l_fp now; 417 418 get_systime(&now); 419 filegen_setup(gen, now.l_ui); 420 } 421 } 422 423 424 /* 425 * check whether concatenating prefix and basename 426 * yields a legal filename 427 */ 428 static int 429 valid_fileref( 430 char *prefix, 431 char *basename 432 ) 433 { 434 /* 435 * prefix cannot be changed dynamically 436 * (within the context of filegen) 437 * so just reject basenames containing '..' 438 * 439 * ASSUMPTION: 440 * file system parts 'below' prefix may be 441 * specified without infringement of security 442 * 443 * restricing prefix to legal values 444 * has to be ensured by other means 445 * (however, it would be possible to perform some checks here...) 446 */ 447 register char *p = basename; 448 449 /* 450 * Just to catch, dumb errors opening up the world... 451 */ 452 if (prefix == NULL || *prefix == '\0') 453 return 0; 454 455 if (basename == NULL) 456 return 0; 457 458 for (p = basename; p; p = strchr(p, '/')) { 459 if (*p == '.' && *(p+1) == '.' && (*(p+2) == '\0' || *(p+2) == '/')) 460 return 0; 461 } 462 463 return 1; 464 } 465 466 467 /* 468 * filegen registry 469 */ 470 471 static struct filegen_entry { 472 char *name; 473 FILEGEN *filegen; 474 struct filegen_entry *next; 475 } *filegen_registry = NULL; 476 477 478 FILEGEN * 479 filegen_get( 480 char *name 481 ) 482 { 483 struct filegen_entry *f = filegen_registry; 484 485 while(f) { 486 if (f->name == name || strcmp(name, f->name) == 0) { 487 #ifdef XXX /* this gives the Alpha compiler fits */ 488 if (debug > 3) 489 printf("filegen_get(\"%s\") = %x\n", name, 490 (u_int)f->filegen); 491 #endif 492 return f->filegen; 493 } 494 f = f->next; 495 } 496 #ifdef DEBUG 497 if (debug > 3) 498 printf("filegen_get(\"%s\") = NULL\n", name); 499 #endif 500 return NULL; 501 } 502 503 void 504 filegen_register( 505 char *prefix, 506 const char *name, 507 FILEGEN *filegen 508 ) 509 { 510 struct filegen_entry **f = &filegen_registry; 511 512 #ifdef XXX /* this gives the Alpha compiler fits */ 513 if (debug > 3) 514 printf("filegen_register(\"%s\",%x)\n", name, (u_int)filegen); 515 #endif 516 517 filegen_init(prefix, name, filegen); 518 519 while (*f) { 520 if ((*f)->name == name || strcmp(name, (*f)->name) == 0) { 521 #ifdef XXX /* this gives the Alpha compiler fits */ 522 if (debug > 4) { 523 printf("replacing filegen %x\n", (u_int)(*f)->filegen); 524 } 525 #endif 526 (*f)->filegen = filegen; 527 return; 528 } 529 f = &((*f)->next); 530 } 531 532 *f = (struct filegen_entry *) emalloc(sizeof(struct filegen_entry)); 533 if (*f) { 534 (*f)->next = NULL; 535 (*f)->name = (char*)emalloc(strlen(name) + 1); 536 strcpy((*f)->name, name); 537 (*f)->filegen = filegen; 538 #ifdef DEBUG 539 if (debug > 5) { 540 printf("adding new filegen\n"); 541 } 542 #endif 543 } 544 545 return; 546 } 547 548 #ifdef UNUSED 549 static FILEGEN * 550 filegen_unregister( 551 char *name 552 ) 553 { 554 struct filegen_entry **f = &filegen_registry; 555 556 #ifdef DEBUG 557 if (debug > 3) 558 printf("filegen_unregister(\"%s\")\n", name); 559 #endif 560 561 while (*f) { 562 if (strcmp((*f)->name,name) == 0) { 563 struct filegen_entry *ff = *f; 564 FILEGEN *fg; 565 566 *f = (*f)->next; 567 fg = ff->filegen; 568 free(ff->name); 569 free(ff); 570 return fg; 571 } 572 f = &((*f)->next); 573 } 574 return NULL; 575 } 576 #endif /* UNUSED */ 577