1 /* Copyright 1988,1990,1993,1994 by Paul Vixie 2 * All rights reserved 3 * 4 * Distribute freely, except: don't remove my name from the source or 5 * documentation (don't take credit for my work), mark your changes (don't 6 * get me blamed for your possible bugs), don't alter or remove this 7 * notice. May be sold if buildable source is provided to buyer. No 8 * warrantee of any kind, express or implied, is included with this 9 * software; use at your own risk, responsibility for damages (if any) to 10 * anyone resulting from the use of this software rests entirely with the 11 * user. 12 * 13 * Send bug reports, bug fixes, enhancements, requests, flames, etc., and 14 * I'll try to keep a version up to date. I can be reached as follows: 15 * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul 16 */ 17 18 #if !defined(lint) && !defined(LINT) 19 static const char rcsid[] = 20 "$FreeBSD$"; 21 #endif 22 23 /* vix 26jan87 [RCS has the rest of the log] 24 * vix 30dec86 [written] 25 */ 26 27 28 #include "cron.h" 29 #if SYS_TIME_H 30 # include <sys/time.h> 31 #else 32 # include <time.h> 33 #endif 34 #include <sys/file.h> 35 #include <sys/stat.h> 36 #include <err.h> 37 #include <errno.h> 38 #include <string.h> 39 #include <fcntl.h> 40 #if defined(SYSLOG) 41 # include <syslog.h> 42 #endif 43 44 45 #if defined(LOG_DAEMON) && !defined(LOG_CRON) 46 #define LOG_CRON LOG_DAEMON 47 #endif 48 49 50 static int LogFD = ERR; 51 52 53 int 54 strcmp_until(left, right, until) 55 char *left; 56 char *right; 57 int until; 58 { 59 register int diff; 60 61 while (*left && *left != until && *left == *right) { 62 left++; 63 right++; 64 } 65 66 if ((*left=='\0' || *left == until) && 67 (*right=='\0' || *right == until)) { 68 diff = 0; 69 } else { 70 diff = *left - *right; 71 } 72 73 return diff; 74 } 75 76 77 /* strdtb(s) - delete trailing blanks in string 's' and return new length 78 */ 79 int 80 strdtb(s) 81 char *s; 82 { 83 char *x = s; 84 85 /* scan forward to the null 86 */ 87 while (*x) 88 x++; 89 90 /* scan backward to either the first character before the string, 91 * or the last non-blank in the string, whichever comes first. 92 */ 93 do {x--;} 94 while (x >= s && isspace(*x)); 95 96 /* one character beyond where we stopped above is where the null 97 * goes. 98 */ 99 *++x = '\0'; 100 101 /* the difference between the position of the null character and 102 * the position of the first character of the string is the length. 103 */ 104 return x - s; 105 } 106 107 108 int 109 set_debug_flags(flags) 110 char *flags; 111 { 112 /* debug flags are of the form flag[,flag ...] 113 * 114 * if an error occurs, print a message to stdout and return FALSE. 115 * otherwise return TRUE after setting ERROR_FLAGS. 116 */ 117 118 #if !DEBUGGING 119 120 printf("this program was compiled without debugging enabled\n"); 121 return FALSE; 122 123 #else /* DEBUGGING */ 124 125 char *pc = flags; 126 127 DebugFlags = 0; 128 129 while (*pc) { 130 char **test; 131 int mask; 132 133 /* try to find debug flag name in our list. 134 */ 135 for ( test = DebugFlagNames, mask = 1; 136 *test && strcmp_until(*test, pc, ','); 137 test++, mask <<= 1 138 ) 139 ; 140 141 if (!*test) { 142 fprintf(stderr, 143 "unrecognized debug flag <%s> <%s>\n", 144 flags, pc); 145 return FALSE; 146 } 147 148 DebugFlags |= mask; 149 150 /* skip to the next flag 151 */ 152 while (*pc && *pc != ',') 153 pc++; 154 if (*pc == ',') 155 pc++; 156 } 157 158 if (DebugFlags) { 159 int flag; 160 161 fprintf(stderr, "debug flags enabled:"); 162 163 for (flag = 0; DebugFlagNames[flag]; flag++) 164 if (DebugFlags & (1 << flag)) 165 fprintf(stderr, " %s", DebugFlagNames[flag]); 166 fprintf(stderr, "\n"); 167 } 168 169 return TRUE; 170 171 #endif /* DEBUGGING */ 172 } 173 174 175 void 176 set_cron_uid() 177 { 178 #if defined(BSD) || defined(POSIX) 179 if (seteuid(ROOT_UID) < OK) 180 err(ERROR_EXIT, "seteuid"); 181 #else 182 if (setuid(ROOT_UID) < OK) 183 err(ERROR_EXIT, "setuid"); 184 #endif 185 } 186 187 188 void 189 set_cron_cwd() 190 { 191 struct stat sb; 192 193 /* first check for CRONDIR ("/var/cron" or some such) 194 */ 195 if (stat(CRONDIR, &sb) < OK && errno == ENOENT) { 196 warn("%s", CRONDIR); 197 if (OK == mkdir(CRONDIR, 0700)) { 198 warnx("%s: created", CRONDIR); 199 stat(CRONDIR, &sb); 200 } else { 201 err(ERROR_EXIT, "%s: mkdir", CRONDIR); 202 } 203 } 204 if (!(sb.st_mode & S_IFDIR)) 205 err(ERROR_EXIT, "'%s' is not a directory, bailing out", CRONDIR); 206 if (chdir(CRONDIR) < OK) 207 err(ERROR_EXIT, "cannot chdir(%s), bailing out", CRONDIR); 208 209 /* CRONDIR okay (now==CWD), now look at SPOOL_DIR ("tabs" or some such) 210 */ 211 if (stat(SPOOL_DIR, &sb) < OK && errno == ENOENT) { 212 warn("%s", SPOOL_DIR); 213 if (OK == mkdir(SPOOL_DIR, 0700)) { 214 warnx("%s: created", SPOOL_DIR); 215 stat(SPOOL_DIR, &sb); 216 } else { 217 err(ERROR_EXIT, "%s: mkdir", SPOOL_DIR); 218 } 219 } 220 if (!(sb.st_mode & S_IFDIR)) 221 err(ERROR_EXIT, "'%s' is not a directory, bailing out", SPOOL_DIR); 222 } 223 224 225 /* acquire_daemonlock() - write our PID into /etc/cron.pid, unless 226 * another daemon is already running, which we detect here. 227 * 228 * note: main() calls us twice; once before forking, once after. 229 * we maintain static storage of the file pointer so that we 230 * can rewrite our PID into the PIDFILE after the fork. 231 * 232 * it would be great if fflush() disassociated the file buffer. 233 */ 234 void 235 acquire_daemonlock(closeflag) 236 int closeflag; 237 { 238 static FILE *fp = NULL; 239 240 if (closeflag && fp) { 241 fclose(fp); 242 fp = NULL; 243 return; 244 } 245 246 if (!fp) { 247 char pidfile[MAX_FNAME]; 248 char buf[MAX_TEMPSTR]; 249 int fd, otherpid; 250 251 (void) sprintf(pidfile, PIDFILE, PIDDIR); 252 if ((-1 == (fd = open(pidfile, O_RDWR|O_CREAT, 0644))) 253 || (NULL == (fp = fdopen(fd, "r+"))) 254 ) { 255 sprintf(buf, "can't open or create %s: %s", 256 pidfile, strerror(errno)); 257 log_it("CRON", getpid(), "DEATH", buf); 258 errx(ERROR_EXIT, "%s", buf); 259 } 260 261 if (flock(fd, LOCK_EX|LOCK_NB) < OK) { 262 int save_errno = errno; 263 264 fscanf(fp, "%d", &otherpid); 265 sprintf(buf, "can't lock %s, otherpid may be %d: %s", 266 pidfile, otherpid, strerror(save_errno)); 267 log_it("CRON", getpid(), "DEATH", buf); 268 errx(ERROR_EXIT, "%s", buf); 269 } 270 271 (void) fcntl(fd, F_SETFD, 1); 272 } 273 274 rewind(fp); 275 fprintf(fp, "%d\n", getpid()); 276 fflush(fp); 277 (void) ftruncate(fileno(fp), ftell(fp)); 278 279 /* abandon fd and fp even though the file is open. we need to 280 * keep it open and locked, but we don't need the handles elsewhere. 281 */ 282 } 283 284 /* get_char(file) : like getc() but increment LineNumber on newlines 285 */ 286 int 287 get_char(file) 288 FILE *file; 289 { 290 int ch; 291 292 ch = getc(file); 293 if (ch == '\n') 294 Set_LineNum(LineNumber + 1) 295 return ch; 296 } 297 298 299 /* unget_char(ch, file) : like ungetc but do LineNumber processing 300 */ 301 void 302 unget_char(ch, file) 303 int ch; 304 FILE *file; 305 { 306 ungetc(ch, file); 307 if (ch == '\n') 308 Set_LineNum(LineNumber - 1) 309 } 310 311 312 /* get_string(str, max, file, termstr) : like fgets() but 313 * (1) has terminator string which should include \n 314 * (2) will always leave room for the null 315 * (3) uses get_char() so LineNumber will be accurate 316 * (4) returns EOF or terminating character, whichever 317 */ 318 int 319 get_string(string, size, file, terms) 320 char *string; 321 int size; 322 FILE *file; 323 char *terms; 324 { 325 int ch; 326 327 while (EOF != (ch = get_char(file)) && !strchr(terms, ch)) { 328 if (size > 1) { 329 *string++ = (char) ch; 330 size--; 331 } 332 } 333 334 if (size > 0) 335 *string = '\0'; 336 337 return ch; 338 } 339 340 341 /* skip_comments(file) : read past comment (if any) 342 */ 343 void 344 skip_comments(file) 345 FILE *file; 346 { 347 int ch; 348 349 while (EOF != (ch = get_char(file))) { 350 /* ch is now the first character of a line. 351 */ 352 353 while (ch == ' ' || ch == '\t') 354 ch = get_char(file); 355 356 if (ch == EOF) 357 break; 358 359 /* ch is now the first non-blank character of a line. 360 */ 361 362 if (ch != '\n' && ch != '#') 363 break; 364 365 /* ch must be a newline or comment as first non-blank 366 * character on a line. 367 */ 368 369 while (ch != '\n' && ch != EOF) 370 ch = get_char(file); 371 372 /* ch is now the newline of a line which we're going to 373 * ignore. 374 */ 375 } 376 if (ch != EOF) 377 unget_char(ch, file); 378 } 379 380 381 /* int in_file(char *string, FILE *file) 382 * return TRUE if one of the lines in file matches string exactly, 383 * FALSE otherwise. 384 */ 385 static int 386 in_file(string, file) 387 char *string; 388 FILE *file; 389 { 390 char line[MAX_TEMPSTR]; 391 392 rewind(file); 393 while (fgets(line, MAX_TEMPSTR, file)) { 394 if (line[0] != '\0') 395 if (line[strlen(line)-1] == '\n') 396 line[strlen(line)-1] = '\0'; 397 if (0 == strcmp(line, string)) 398 return TRUE; 399 } 400 return FALSE; 401 } 402 403 404 /* int allowed(char *username) 405 * returns TRUE if (ALLOW_FILE exists and user is listed) 406 * or (DENY_FILE exists and user is NOT listed) 407 * or (neither file exists but user=="root" so it's okay) 408 */ 409 int 410 allowed(username) 411 char *username; 412 { 413 FILE *allow, *deny; 414 int isallowed; 415 416 isallowed = FALSE; 417 418 #if defined(ALLOW_FILE) && defined(DENY_FILE) 419 if ((allow = fopen(ALLOW_FILE, "r")) == NULL && errno != ENOENT) 420 goto out; 421 if ((deny = fopen(DENY_FILE, "r")) == NULL && errno != ENOENT) 422 goto out; 423 Debug(DMISC, ("allow/deny enabled, %d/%d\n", !!allow, !!deny)) 424 #else 425 allow = NULL; 426 deny = NULL; 427 #endif 428 429 if (allow) 430 isallowed = in_file(username, allow); 431 else if (deny) 432 isallowed = !in_file(username, deny); 433 else { 434 #if defined(ALLOW_ONLY_ROOT) 435 isallowed = (strcmp(username, ROOT_USER) == 0); 436 #else 437 isallowed = TRUE; 438 #endif 439 } 440 out: if (allow) 441 fclose(allow); 442 if (deny) 443 fclose(deny); 444 return (isallowed); 445 } 446 447 448 void 449 log_it(username, xpid, event, detail) 450 char *username; 451 int xpid; 452 char *event; 453 char *detail; 454 { 455 PID_T pid = xpid; 456 #if defined(LOG_FILE) 457 char *msg; 458 TIME_T now = time((TIME_T) 0); 459 register struct tm *t = localtime(&now); 460 #endif /*LOG_FILE*/ 461 462 #if defined(SYSLOG) 463 static int syslog_open = 0; 464 #endif 465 466 #if defined(LOG_FILE) 467 /* we assume that MAX_TEMPSTR will hold the date, time, &punctuation. 468 */ 469 msg = malloc(strlen(username) 470 + strlen(event) 471 + strlen(detail) 472 + MAX_TEMPSTR); 473 474 if (msg == NULL) 475 warnx("failed to allocate memory for log message"); 476 else { 477 if (LogFD < OK) { 478 LogFD = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600); 479 if (LogFD < OK) { 480 warn("can't open log file %s", LOG_FILE); 481 } else { 482 (void) fcntl(LogFD, F_SETFD, 1); 483 } 484 } 485 486 /* we have to sprintf() it because fprintf() doesn't always 487 * write everything out in one chunk and this has to be 488 * atomically appended to the log file. 489 */ 490 sprintf(msg, "%s (%02d/%02d-%02d:%02d:%02d-%d) %s (%s)\n", 491 username, 492 t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, 493 t->tm_sec, pid, event, detail); 494 495 /* we have to run strlen() because sprintf() returns (char*) 496 * on old BSD. 497 */ 498 if (LogFD < OK || write(LogFD, msg, strlen(msg)) < OK) { 499 if (LogFD >= OK) 500 warn("%s", LOG_FILE); 501 warnx("can't write to log file"); 502 write(STDERR, msg, strlen(msg)); 503 } 504 505 free(msg); 506 } 507 #endif /*LOG_FILE*/ 508 509 #if defined(SYSLOG) 510 if (!syslog_open) { 511 /* we don't use LOG_PID since the pid passed to us by 512 * our client may not be our own. therefore we want to 513 * print the pid ourselves. 514 */ 515 # ifdef LOG_DAEMON 516 openlog(ProgramName, LOG_PID, LOG_CRON); 517 # else 518 openlog(ProgramName, LOG_PID); 519 # endif 520 syslog_open = TRUE; /* assume openlog success */ 521 } 522 523 syslog(LOG_INFO, "(%s) %s (%s)\n", username, event, detail); 524 525 #endif /*SYSLOG*/ 526 527 #if DEBUGGING 528 if (DebugFlags) { 529 fprintf(stderr, "log_it: (%s %d) %s (%s)\n", 530 username, pid, event, detail); 531 } 532 #endif 533 } 534 535 536 void 537 log_close() { 538 if (LogFD != ERR) { 539 close(LogFD); 540 LogFD = ERR; 541 } 542 } 543 544 545 /* two warnings: 546 * (1) this routine is fairly slow 547 * (2) it returns a pointer to static storage 548 */ 549 char * 550 first_word(s, t) 551 register char *s; /* string we want the first word of */ 552 register char *t; /* terminators, implicitly including \0 */ 553 { 554 static char retbuf[2][MAX_TEMPSTR + 1]; /* sure wish C had GC */ 555 static int retsel = 0; 556 register char *rb, *rp; 557 558 /* select a return buffer */ 559 retsel = 1-retsel; 560 rb = &retbuf[retsel][0]; 561 rp = rb; 562 563 /* skip any leading terminators */ 564 while (*s && (NULL != strchr(t, *s))) { 565 s++; 566 } 567 568 /* copy until next terminator or full buffer */ 569 while (*s && (NULL == strchr(t, *s)) && (rp < &rb[MAX_TEMPSTR])) { 570 *rp++ = *s++; 571 } 572 573 /* finish the return-string and return it */ 574 *rp = '\0'; 575 return rb; 576 } 577 578 579 /* warning: 580 * heavily ascii-dependent. 581 */ 582 void 583 mkprint(dst, src, len) 584 register char *dst; 585 register unsigned char *src; 586 register int len; 587 { 588 while (len-- > 0) 589 { 590 register unsigned char ch = *src++; 591 592 if (ch < ' ') { /* control character */ 593 *dst++ = '^'; 594 *dst++ = ch + '@'; 595 } else if (ch < 0177) { /* printable */ 596 *dst++ = ch; 597 } else if (ch == 0177) { /* delete/rubout */ 598 *dst++ = '^'; 599 *dst++ = '?'; 600 } else { /* parity character */ 601 sprintf(dst, "\\%03o", ch); 602 dst += 4; 603 } 604 } 605 *dst = '\0'; 606 } 607 608 609 /* warning: 610 * returns a pointer to malloc'd storage, you must call free yourself. 611 */ 612 char * 613 mkprints(src, len) 614 register unsigned char *src; 615 register unsigned int len; 616 { 617 register char *dst = malloc(len*4 + 1); 618 619 if (dst != NULL) 620 mkprint(dst, src, len); 621 622 return dst; 623 } 624 625 626 #ifdef MAIL_DATE 627 /* Sat, 27 Feb 93 11:44:51 CST 628 * 123456789012345678901234567 629 */ 630 char * 631 arpadate(clock) 632 time_t *clock; 633 { 634 time_t t = clock ?*clock :time(0L); 635 struct tm *tm = localtime(&t); 636 static char ret[32]; /* zone name might be >3 chars */ 637 638 if (tm->tm_year >= 100) 639 tm->tm_year += 1900; 640 641 (void) snprintf(ret, sizeof(ret), "%s, %2d %s %d %02d:%02d:%02d %s", 642 DowNames[tm->tm_wday], 643 tm->tm_mday, 644 MonthNames[tm->tm_mon], 645 tm->tm_year, 646 tm->tm_hour, 647 tm->tm_min, 648 tm->tm_sec, 649 TZONE(*tm)); 650 return ret; 651 } 652 #endif /*MAIL_DATE*/ 653 654 655 #ifdef HAVE_SAVED_UIDS 656 static int save_euid; 657 int swap_uids() { save_euid = geteuid(); return seteuid(getuid()); } 658 int swap_uids_back() { return seteuid(save_euid); } 659 #else /*HAVE_SAVED_UIDS*/ 660 int swap_uids() { return setreuid(geteuid(), getuid()); } 661 int swap_uids_back() { return swap_uids(); } 662 #endif /*HAVE_SAVED_UIDS*/ 663