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 "$Id: misc.c,v 1.6 1997/09/15 06:39:25 charnier Exp $"; 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 line[strlen(line)-1] = '\0'; 396 if (0 == strcmp(line, string)) 397 return TRUE; 398 } 399 return FALSE; 400 } 401 402 403 /* int allowed(char *username) 404 * returns TRUE if (ALLOW_FILE exists and user is listed) 405 * or (DENY_FILE exists and user is NOT listed) 406 * or (neither file exists but user=="root" so it's okay) 407 */ 408 int 409 allowed(username) 410 char *username; 411 { 412 static int init = FALSE; 413 static FILE *allow, *deny; 414 415 if (!init) { 416 init = TRUE; 417 #if defined(ALLOW_FILE) && defined(DENY_FILE) 418 allow = fopen(ALLOW_FILE, "r"); 419 deny = fopen(DENY_FILE, "r"); 420 Debug(DMISC, ("allow/deny enabled, %d/%d\n", !!allow, !!deny)) 421 #else 422 allow = NULL; 423 deny = NULL; 424 #endif 425 } 426 427 if (allow) 428 return (in_file(username, allow)); 429 if (deny) 430 return (!in_file(username, deny)); 431 432 #if defined(ALLOW_ONLY_ROOT) 433 return (strcmp(username, ROOT_USER) == 0); 434 #else 435 return TRUE; 436 #endif 437 } 438 439 440 void 441 log_it(username, xpid, event, detail) 442 char *username; 443 int xpid; 444 char *event; 445 char *detail; 446 { 447 PID_T pid = xpid; 448 #if defined(LOG_FILE) 449 char *msg; 450 TIME_T now = time((TIME_T) 0); 451 register struct tm *t = localtime(&now); 452 #endif /*LOG_FILE*/ 453 454 #if defined(SYSLOG) 455 static int syslog_open = 0; 456 #endif 457 458 #if defined(LOG_FILE) 459 /* we assume that MAX_TEMPSTR will hold the date, time, &punctuation. 460 */ 461 msg = malloc(strlen(username) 462 + strlen(event) 463 + strlen(detail) 464 + MAX_TEMPSTR); 465 466 if (LogFD < OK) { 467 LogFD = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600); 468 if (LogFD < OK) { 469 warn("can't open log file %s", LOG_FILE); 470 } else { 471 (void) fcntl(LogFD, F_SETFD, 1); 472 } 473 } 474 475 /* we have to sprintf() it because fprintf() doesn't always write 476 * everything out in one chunk and this has to be atomically appended 477 * to the log file. 478 */ 479 sprintf(msg, "%s (%02d/%02d-%02d:%02d:%02d-%d) %s (%s)\n", 480 username, 481 t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, pid, 482 event, detail); 483 484 /* we have to run strlen() because sprintf() returns (char*) on old BSD 485 */ 486 if (LogFD < OK || write(LogFD, msg, strlen(msg)) < OK) { 487 if (LogFD >= OK) 488 warn("%s", LOG_FILE); 489 warnx("can't write to log file"); 490 write(STDERR, msg, strlen(msg)); 491 } 492 493 free(msg); 494 #endif /*LOG_FILE*/ 495 496 #if defined(SYSLOG) 497 if (!syslog_open) { 498 /* we don't use LOG_PID since the pid passed to us by 499 * our client may not be our own. therefore we want to 500 * print the pid ourselves. 501 */ 502 # ifdef LOG_DAEMON 503 openlog(ProgramName, LOG_PID, LOG_CRON); 504 # else 505 openlog(ProgramName, LOG_PID); 506 # endif 507 syslog_open = TRUE; /* assume openlog success */ 508 } 509 510 syslog(LOG_INFO, "(%s) %s (%s)\n", username, event, detail); 511 512 #endif /*SYSLOG*/ 513 514 #if DEBUGGING 515 if (DebugFlags) { 516 fprintf(stderr, "log_it: (%s %d) %s (%s)\n", 517 username, pid, event, detail); 518 } 519 #endif 520 } 521 522 523 void 524 log_close() { 525 if (LogFD != ERR) { 526 close(LogFD); 527 LogFD = ERR; 528 } 529 } 530 531 532 /* two warnings: 533 * (1) this routine is fairly slow 534 * (2) it returns a pointer to static storage 535 */ 536 char * 537 first_word(s, t) 538 register char *s; /* string we want the first word of */ 539 register char *t; /* terminators, implicitly including \0 */ 540 { 541 static char retbuf[2][MAX_TEMPSTR + 1]; /* sure wish C had GC */ 542 static int retsel = 0; 543 register char *rb, *rp; 544 545 /* select a return buffer */ 546 retsel = 1-retsel; 547 rb = &retbuf[retsel][0]; 548 rp = rb; 549 550 /* skip any leading terminators */ 551 while (*s && (NULL != strchr(t, *s))) { 552 s++; 553 } 554 555 /* copy until next terminator or full buffer */ 556 while (*s && (NULL == strchr(t, *s)) && (rp < &rb[MAX_TEMPSTR])) { 557 *rp++ = *s++; 558 } 559 560 /* finish the return-string and return it */ 561 *rp = '\0'; 562 return rb; 563 } 564 565 566 /* warning: 567 * heavily ascii-dependent. 568 */ 569 void 570 mkprint(dst, src, len) 571 register char *dst; 572 register unsigned char *src; 573 register int len; 574 { 575 while (len-- > 0) 576 { 577 register unsigned char ch = *src++; 578 579 if (ch < ' ') { /* control character */ 580 *dst++ = '^'; 581 *dst++ = ch + '@'; 582 } else if (ch < 0177) { /* printable */ 583 *dst++ = ch; 584 } else if (ch == 0177) { /* delete/rubout */ 585 *dst++ = '^'; 586 *dst++ = '?'; 587 } else { /* parity character */ 588 sprintf(dst, "\\%03o", ch); 589 dst += 4; 590 } 591 } 592 *dst = '\0'; 593 } 594 595 596 /* warning: 597 * returns a pointer to malloc'd storage, you must call free yourself. 598 */ 599 char * 600 mkprints(src, len) 601 register unsigned char *src; 602 register unsigned int len; 603 { 604 register char *dst = malloc(len*4 + 1); 605 606 mkprint(dst, src, len); 607 608 return dst; 609 } 610 611 612 #ifdef MAIL_DATE 613 /* Sat, 27 Feb 93 11:44:51 CST 614 * 123456789012345678901234567 615 */ 616 char * 617 arpadate(clock) 618 time_t *clock; 619 { 620 time_t t = clock ?*clock :time(0L); 621 struct tm *tm = localtime(&t); 622 static char ret[32]; /* zone name might be >3 chars */ 623 624 if (tm->tm_year >= 100) 625 tm->tm_year += 1900; 626 627 (void) snprintf(ret, sizeof(ret), "%s, %2d %s %d %02d:%02d:%02d %s", 628 DowNames[tm->tm_wday], 629 tm->tm_mday, 630 MonthNames[tm->tm_mon], 631 tm->tm_year, 632 tm->tm_hour, 633 tm->tm_min, 634 tm->tm_sec, 635 TZONE(*tm)); 636 return ret; 637 } 638 #endif /*MAIL_DATE*/ 639 640 641 #ifdef HAVE_SAVED_UIDS 642 static int save_euid; 643 int swap_uids() { save_euid = geteuid(); return seteuid(getuid()); } 644 int swap_uids_back() { return seteuid(save_euid); } 645 #else /*HAVE_SAVED_UIDS*/ 646 int swap_uids() { return setreuid(geteuid(), getuid()); } 647 int swap_uids_back() { return swap_uids(); } 648 #endif /*HAVE_SAVED_UIDS*/ 649