1 /* $NetBSD: misc.c,v 1.2 2010/05/06 18:53:17 christos Exp $ */ 2 3 /* Copyright 1988,1990,1993,1994 by Paul Vixie 4 * All rights reserved 5 */ 6 7 /* 8 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 9 * Copyright (c) 1997,2000 by Internet Software Consortium, Inc. 10 * 11 * Permission to use, copy, modify, and distribute this software for any 12 * purpose with or without fee is hereby granted, provided that the above 13 * copyright notice and this permission notice appear in all copies. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 16 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 17 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 18 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 19 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 20 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 21 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 22 */ 23 #include <sys/cdefs.h> 24 #if !defined(lint) && !defined(LINT) 25 #if 0 26 static char rcsid[] = "Id: misc.c,v 1.16 2004/01/23 18:56:43 vixie Exp"; 27 #else 28 __RCSID("$NetBSD: misc.c,v 1.2 2010/05/06 18:53:17 christos Exp $"); 29 #endif 30 #endif 31 32 /* vix 26jan87 [RCS has the rest of the log] 33 * vix 30dec86 [written] 34 */ 35 36 #include "cron.h" 37 #include <limits.h> 38 #include <vis.h> 39 40 #if defined(SYSLOG) && defined(LOG_FILE) 41 # undef LOG_FILE 42 #endif 43 44 #if defined(LOG_DAEMON) && !defined(LOG_CRON) 45 # define LOG_CRON LOG_DAEMON 46 #endif 47 48 #ifndef FACILITY 49 #define FACILITY LOG_CRON 50 #endif 51 52 static int LogFD = ERR; 53 54 #if defined(SYSLOG) 55 static int syslog_open = FALSE; 56 #endif 57 58 static void mkprint(char *, char *, size_t); 59 60 /* 61 * glue_strings is the overflow-safe equivalent of 62 * sprintf(buffer, "%s%c%s", a, separator, b); 63 * 64 * returns 1 on success, 0 on failure. 'buffer' MUST NOT be used if 65 * glue_strings fails. 66 */ 67 int 68 glue_strings(char *buffer, size_t buffer_size, const char *a, const char *b, 69 char separator) 70 { 71 char *buf; 72 char *buf_end; 73 74 if (buffer_size == 0) 75 return (0); 76 buf_end = buffer + buffer_size; 77 buf = buffer; 78 79 for ( /* nothing */; buf < buf_end && *a != '\0'; buf++, a++ ) 80 *buf = *a; 81 if (buf == buf_end) 82 return (0); 83 if (separator != '/' || buf == buffer || buf[-1] != '/') 84 *buf++ = separator; 85 if (buf == buf_end) 86 return (0); 87 for ( /* nothing */; buf < buf_end && *b != '\0'; buf++, b++ ) 88 *buf = *b; 89 if (buf == buf_end) 90 return (0); 91 *buf = '\0'; 92 return (1); 93 } 94 95 int 96 strcmp_until(const char *left, const char *right, char until) { 97 while (*left && *left != until && *left == *right) { 98 left++; 99 right++; 100 } 101 102 if ((*left=='\0' || *left == until) && 103 (*right=='\0' || *right == until)) { 104 return (0); 105 } 106 return (*left - *right); 107 } 108 109 #ifdef notdef 110 /* strdtb(s) - delete trailing blanks in string 's' and return new length 111 */ 112 int 113 strdtb(char *s) { 114 char *x = s; 115 116 /* scan forward to the null 117 */ 118 while (*x) 119 x++; 120 121 /* scan backward to either the first character before the string, 122 * or the last non-blank in the string, whichever comes first. 123 */ 124 do {x--;} 125 while (x >= s && isspace((unsigned char)*x)); 126 127 /* one character beyond where we stopped above is where the null 128 * goes. 129 */ 130 *++x = '\0'; 131 132 /* the difference between the position of the null character and 133 * the position of the first character of the string is the length. 134 */ 135 return (int)(x - s); 136 } 137 #endif 138 139 int 140 set_debug_flags(const char *flags) { 141 /* debug flags are of the form flag[,flag ...] 142 * 143 * if an error occurs, print a message to stdout and return FALSE. 144 * otherwise return TRUE after setting ERROR_FLAGS. 145 */ 146 147 #if !DEBUGGING 148 149 printf("this program was compiled without debugging enabled\n"); 150 return (FALSE); 151 152 #else /* DEBUGGING */ 153 154 const char *pc = flags; 155 156 DebugFlags = 0; 157 158 while (*pc) { 159 const char * const *test; 160 int mask; 161 162 /* try to find debug flag name in our list. 163 */ 164 for (test = DebugFlagNames, mask = 1; 165 *test != NULL && strcmp_until(*test, pc, ','); 166 test++, mask <<= 1) 167 continue; 168 169 if (!*test) { 170 warnx("unrecognized debug flag <%s> <%s>\n", flags, pc); 171 return (FALSE); 172 } 173 174 DebugFlags |= mask; 175 176 /* skip to the next flag 177 */ 178 while (*pc && *pc != ',') 179 pc++; 180 if (*pc == ',') 181 pc++; 182 } 183 184 if (DebugFlags) { 185 int flag; 186 187 (void)fprintf(stderr, "debug flags enabled:"); 188 189 for (flag = 0; DebugFlagNames[flag]; flag++) 190 if (DebugFlags & (1 << flag)) 191 (void)fprintf(stderr, " %s", DebugFlagNames[flag]); 192 (void)fprintf(stderr, "\n"); 193 } 194 195 return (TRUE); 196 197 #endif /* DEBUGGING */ 198 } 199 200 void 201 set_cron_uid(void) { 202 #if defined(BSD) || defined(POSIX) 203 if (seteuid(ROOT_UID) < OK) { 204 err(ERROR_EXIT, "cannot seteuid"); 205 } 206 #else 207 if (setuid(ROOT_UID) < OK) { 208 err(ERROR_EXIT, "cannot setuid"); 209 } 210 #endif 211 } 212 213 void 214 set_cron_cwd(void) { 215 struct stat sb; 216 struct group *grp = NULL; 217 218 #ifdef CRON_GROUP 219 grp = getgrnam(CRON_GROUP); 220 #endif 221 /* first check for CRONDIR ("/var/cron" or some such) 222 */ 223 if (stat(CRONDIR, &sb) < OK && errno == ENOENT) { 224 warn("Cannot stat `%s'", CRONDIR); 225 if (OK == mkdir(CRONDIR, 0710)) { 226 (void)fprintf(stderr, "%s: created\n", CRONDIR); 227 if (stat(CRONDIR, &sb) == -1) 228 err(ERROR_EXIT, "cannot stat `%s'", CRONDIR); 229 } else { 230 err(ERROR_EXIT, "cannot create `%s'", CRONDIR); 231 } 232 } 233 if (!S_ISDIR(sb.st_mode)) { 234 errx(ERROR_EXIT, "`%s' is not a directory, bailing out.", 235 CRONDIR); 236 } 237 if (chdir(CRONDIR) < OK) { 238 err(ERROR_EXIT, "cannot chdir `%s', bailing out.\n", CRONDIR); 239 } 240 241 /* CRONDIR okay (now==CWD), now look at SPOOL_DIR ("tabs" or some such) 242 */ 243 if (stat(SPOOL_DIR, &sb) < OK && errno == ENOENT) { 244 warn("cannot stat `%s'", SPOOL_DIR); 245 if (OK == mkdir(SPOOL_DIR, 0700)) { 246 (void)fprintf(stderr, "%s: created\n", SPOOL_DIR); 247 if (stat(SPOOL_DIR, &sb) == -1) 248 err(ERROR_EXIT, "cannot stat `%s'", CRONDIR); 249 } else { 250 err(ERROR_EXIT, "cannot create `%s'", SPOOL_DIR); 251 } 252 } 253 if (!S_ISDIR(sb.st_mode)) { 254 errx(ERROR_EXIT, "`%s' is not a directory, bailing out.", 255 SPOOL_DIR); 256 } 257 if (grp != NULL) { 258 if (sb.st_gid != grp->gr_gid) 259 if (chown(SPOOL_DIR, (uid_t)-1, grp->gr_gid) == -1) 260 err(ERROR_EXIT, "cannot chown `%s'", SPOOL_DIR); 261 if (sb.st_mode != 01730) 262 if (chmod(SPOOL_DIR, 01730) == -1) 263 err(ERROR_EXIT, "cannot chmod `%s'", SPOOL_DIR); 264 } 265 } 266 267 /* acquire_daemonlock() - write our PID into /etc/cron.pid, unless 268 * another daemon is already running, which we detect here. 269 * 270 * note: main() calls us twice; once before forking, once after. 271 * we maintain static storage of the file pointer so that we 272 * can rewrite our PID into _PATH_CRON_PID after the fork. 273 */ 274 void 275 acquire_daemonlock(int closeflag) { 276 static int fd = -1; 277 char buf[3*MAX_FNAME]; 278 const char *pidfile; 279 char *ep; 280 long otherpid; 281 ssize_t num; 282 283 if (closeflag) { 284 /* close stashed fd for child so we don't leak it. */ 285 if (fd != -1) { 286 (void)close(fd); 287 fd = -1; 288 } 289 return; 290 } 291 292 if (fd == -1) { 293 pidfile = _PATH_CRON_PID; 294 /* Initial mode is 0600 to prevent flock() race/DoS. */ 295 if ((fd = open(pidfile, O_RDWR|O_CREAT, 0600)) == -1) { 296 (void)snprintf(buf, sizeof(buf), 297 "can't open or create %s: %s", 298 pidfile, strerror(errno)); 299 log_it("CRON", getpid(), "DEATH", buf); 300 errx(ERROR_EXIT, "%s", buf); 301 } 302 303 if (flock(fd, LOCK_EX|LOCK_NB) < OK) { 304 int save_errno = errno; 305 306 memset(buf, 0, sizeof(buf)); 307 if ((num = read(fd, buf, sizeof(buf) - 1)) > 0 && 308 (otherpid = strtol(buf, &ep, 10)) > 0 && 309 ep != buf && *ep == '\n' && otherpid != LONG_MAX) { 310 (void)snprintf(buf, sizeof(buf), 311 "can't lock %s, otherpid may be %ld: %s", 312 pidfile, otherpid, strerror(save_errno)); 313 } else { 314 (void)snprintf(buf, sizeof(buf), 315 "can't lock %s, otherpid unknown: %s", 316 pidfile, strerror(save_errno)); 317 } 318 log_it("CRON", getpid(), "DEATH", buf); 319 errx(ERROR_EXIT, "%s", buf); 320 } 321 (void) fchmod(fd, 0644); 322 (void) fcntl(fd, F_SETFD, 1); 323 } 324 325 (void)snprintf(buf, sizeof(buf), "%ld\n", (long)getpid()); 326 (void) lseek(fd, (off_t)0, SEEK_SET); 327 num = write(fd, buf, strlen(buf)); 328 (void) ftruncate(fd, num); 329 330 /* abandon fd even though the file is open. we need to keep 331 * it open and locked, but we don't need the handles elsewhere. 332 */ 333 } 334 335 /* get_char(file) : like getc() but increment LineNumber on newlines 336 */ 337 int 338 get_char(FILE *file) { 339 int ch; 340 341 ch = getc(file); 342 if (ch == '\n') 343 Set_LineNum(LineNumber + 1); 344 return (ch); 345 } 346 347 /* unget_char(ch, file) : like ungetc but do LineNumber processing 348 */ 349 void 350 unget_char(int ch, FILE *file) { 351 (void)ungetc(ch, file); 352 if (ch == '\n') 353 Set_LineNum(LineNumber - 1); 354 } 355 356 /* get_string(str, max, file, termstr) : like fgets() but 357 * (1) has terminator string which should include \n 358 * (2) will always leave room for the null 359 * (3) uses get_char() so LineNumber will be accurate 360 * (4) returns EOF or terminating character, whichever 361 */ 362 int 363 get_string(char *string, int size, FILE *file, const char *terms) { 364 int ch; 365 366 while (EOF != (ch = get_char(file)) && !strchr(terms, ch)) { 367 if (size > 1) { 368 *string++ = (char) ch; 369 size--; 370 } 371 } 372 373 if (size > 0) 374 *string = '\0'; 375 376 return (ch); 377 } 378 379 /* skip_comments(file) : read past comment (if any) 380 */ 381 void 382 skip_comments(FILE *file) { 383 int ch; 384 385 while (EOF != (ch = get_char(file))) { 386 /* ch is now the first character of a line. 387 */ 388 389 while (ch == ' ' || ch == '\t') 390 ch = get_char(file); 391 392 if (ch == EOF) 393 break; 394 395 /* ch is now the first non-blank character of a line. 396 */ 397 398 if (ch != '\n' && ch != '#') 399 break; 400 401 /* ch must be a newline or comment as first non-blank 402 * character on a line. 403 */ 404 405 while (ch != '\n' && ch != EOF) 406 ch = get_char(file); 407 408 /* ch is now the newline of a line which we're going to 409 * ignore. 410 */ 411 } 412 if (ch != EOF) 413 unget_char(ch, file); 414 } 415 416 void 417 log_it(const char *username, PID_T xpid, const char *event, const char *detail) { 418 #if defined(LOG_FILE) || DEBUGGING 419 PID_T pid = xpid; 420 #endif 421 #if defined(LOG_FILE) 422 char *msg; 423 size_t msglen; 424 TIME_T now = time((TIME_T) 0); 425 struct tm *t = localtime(&now); 426 #endif /*LOG_FILE*/ 427 428 #if defined(LOG_FILE) 429 /* we assume that MAX_TEMPSTR will hold the date, time, &punctuation. 430 */ 431 msglen = strlen(username) + strlen(event) + strlen(detail) + 432 MAX_TEMPSTR); 433 msg = malloc(msglen); 434 if (msg == NULL) 435 return; 436 437 if (LogFD < OK) { 438 LogFD = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600); 439 if (LogFD < OK) { 440 warn("can't open log file `%s'", LOG_FILE); 441 } else { 442 (void) fcntl(LogFD, F_SETFD, FD_CLOEXEC); 443 } 444 } 445 446 /* we have to sprintf() it because fprintf() doesn't always write 447 * everything out in one chunk and this has to be atomically appended 448 * to the log file. 449 */ 450 (void)snprintf(msg, msglen, 451 "%s (%02d/%02d-%02d:%02d:%02d-%d) %s (%s)\n", 452 username, 453 t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, pid, 454 event, detail); 455 456 /* we have to run strlen() because sprintf() returns (char*) on old BSD 457 */ 458 if (LogFD < OK || write(LogFD, msg, strlen(msg)) < OK) { 459 warn("can't write to log file"); 460 write(STDERR, msg, strlen(msg)); 461 } 462 463 free(msg); 464 #endif /*LOG_FILE*/ 465 466 #if defined(SYSLOG) 467 if (!syslog_open) { 468 # ifdef LOG_DAEMON 469 openlog(getprogname(), LOG_PID, FACILITY); 470 # else 471 openlog(getprogname(), LOG_PID); 472 # endif 473 syslog_open = TRUE; /* assume openlog success */ 474 } 475 476 syslog(LOG_INFO, "(%s) %s (%s)", username, event, detail); 477 478 #endif /*SYSLOG*/ 479 480 #if DEBUGGING 481 if (DebugFlags) { 482 (void)fprintf(stderr, "log_it: (%s %ld) %s (%s)\n", 483 username, (long)pid, event, detail); 484 } 485 #endif 486 } 487 488 void 489 log_close(void) { 490 if (LogFD != ERR) { 491 (void)close(LogFD); 492 LogFD = ERR; 493 } 494 #if defined(SYSLOG) 495 closelog(); 496 syslog_open = FALSE; 497 #endif /*SYSLOG*/ 498 } 499 500 /* char *first_word(char *s, char *t) 501 * return pointer to first word 502 * parameters: 503 * s - string we want the first word of 504 * t - terminators, implicitly including \0 505 * warnings: 506 * (1) this routine is fairly slow 507 * (2) it returns a pointer to static storage 508 */ 509 char * 510 first_word(char *s, const char *t) { 511 static char retbuf[2][MAX_TEMPSTR + 1]; /* sure wish C had GC */ 512 static int retsel = 0; 513 char *rb, *rp; 514 515 /* select a return buffer */ 516 retsel = 1-retsel; 517 rb = &retbuf[retsel][0]; 518 rp = rb; 519 520 /* skip any leading terminators */ 521 while (*s && (NULL != strchr(t, *s))) { 522 s++; 523 } 524 525 /* copy until next terminator or full buffer */ 526 while (*s && (NULL == strchr(t, *s)) && (rp < &rb[MAX_TEMPSTR])) { 527 *rp++ = *s++; 528 } 529 530 /* finish the return-string and return it */ 531 *rp = '\0'; 532 return (rb); 533 } 534 535 /* warning: 536 * heavily ascii-dependent. 537 */ 538 static void 539 mkprint(char *dst, char *src, size_t len) 540 { 541 while(len > 0 && isblank((unsigned char) *src)) 542 len--, src++; 543 544 (void)strvisx(dst, src, len, VIS_TAB|VIS_NL); 545 } 546 547 /* warning: 548 * returns a pointer to malloc'd storage, you must call free yourself. 549 */ 550 char * 551 mkprints(char *src, size_t len) 552 { 553 char *dst = malloc(len*4 + 1); 554 555 if (dst) 556 mkprint(dst, src, len); 557 558 return (dst); 559 } 560 561 #ifdef MAIL_DATE 562 /* Sat, 27 Feb 1993 11:44:51 -0800 (CST) 563 * 1234567890123456789012345678901234567 564 */ 565 char * 566 arpadate(time_t *clock) 567 { 568 time_t t = clock ? *clock : time((TIME_T) 0); 569 struct tm tm = *localtime(&t); 570 long gmtoff = get_gmtoff(&t, &tm); 571 int hours = gmtoff / SECONDS_PER_HOUR; 572 int minutes = (gmtoff - (hours * SECONDS_PER_HOUR)) / SECONDS_PER_MINUTE; 573 static char ret[64]; /* zone name might be >3 chars */ 574 575 if (minutes < 0) 576 minutes = -minutes; 577 578 (void)strftime(ret, sizeof(ret), "%a, %e %b %Y %T ????? (%Z)", &tm); 579 (void)snprintf(strchr(ret, '?'), "% .2d%.2d", hours, minutes); 580 ret[sizeof(ret) - 1] = '\0'; 581 return ret; 582 } 583 #endif /*MAIL_DATE*/ 584 585 size_t 586 strlens(const char *last, ...) { 587 va_list ap; 588 size_t ret = 0; 589 const char *str; 590 591 va_start(ap, last); 592 for (str = last; str != NULL; str = va_arg(ap, const char *)) 593 ret += strlen(str); 594 va_end(ap); 595 return (ret); 596 } 597 598 /* Return the offset from GMT in seconds (algorithm taken from sendmail). 599 * 600 * warning: 601 * clobbers the static storage space used by localtime() and gmtime(). 602 * If the local pointer is non-NULL it *must* point to a local copy. 603 */ 604 #ifndef HAVE_TM_GMTOFF 605 long get_gmtoff(time_t *clock, struct tm *local) 606 { 607 struct tm gmt; 608 long offset; 609 610 gmt = *gmtime(clock); 611 if (local == NULL) 612 local = localtime(clock); 613 614 offset = (local->tm_sec - gmt.tm_sec) + 615 ((local->tm_min - gmt.tm_min) * 60) + 616 ((local->tm_hour - gmt.tm_hour) * 3600); 617 618 /* Timezone may cause year rollover to happen on a different day. */ 619 if (local->tm_year < gmt.tm_year) 620 offset -= 24 * 3600; 621 else if (local->tm_year > gmt.tm_year) 622 offset -= 24 * 3600; 623 else if (local->tm_yday < gmt.tm_yday) 624 offset -= 24 * 3600; 625 else if (local->tm_yday > gmt.tm_yday) 626 offset += 24 * 3600; 627 628 return (offset); 629 } 630 #endif /* HAVE_TM_GMTOFF */ 631