entry.c revision 81778
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) 19static const char rcsid[] = 20 "$FreeBSD: head/usr.sbin/cron/lib/entry.c 81778 2001-08-16 14:23:59Z mikeh $"; 21#endif 22 23/* vix 26jan87 [RCS'd; rest of log is in RCS file] 24 * vix 01jan87 [added line-level error recovery] 25 * vix 31dec86 [added /step to the from-to range, per bob@acornrc] 26 * vix 30dec86 [written] 27 */ 28 29 30#include "cron.h" 31#include <grp.h> 32#ifdef LOGIN_CAP 33#include <login_cap.h> 34#endif 35 36typedef enum ecode { 37 e_none, e_minute, e_hour, e_dom, e_month, e_dow, 38 e_cmd, e_timespec, e_username, e_group, e_mem 39#ifdef LOGIN_CAP 40 , e_class 41#endif 42} ecode_e; 43 44static char get_list __P((bitstr_t *, int, int, char *[], int, FILE *)), 45 get_range __P((bitstr_t *, int, int, char *[], int, FILE *)), 46 get_number __P((int *, int, char *[], int, FILE *)); 47static int set_element __P((bitstr_t *, int, int, int)); 48 49static char *ecodes[] = 50 { 51 "no error", 52 "bad minute", 53 "bad hour", 54 "bad day-of-month", 55 "bad month", 56 "bad day-of-week", 57 "bad command", 58 "bad time specifier", 59 "bad username", 60 "bad group name", 61 "out of memory", 62#ifdef LOGIN_CAP 63 "bad class name", 64#endif 65 }; 66 67 68void 69free_entry(e) 70 entry *e; 71{ 72#ifdef LOGIN_CAP 73 if (e->class != NULL) 74 free(e->class); 75#endif 76 if (e->cmd != NULL) 77 free(e->cmd); 78 if (e->envp != NULL) 79 env_free(e->envp); 80 free(e); 81} 82 83 84/* return NULL if eof or syntax error occurs; 85 * otherwise return a pointer to a new entry. 86 */ 87entry * 88load_entry(file, error_func, pw, envp) 89 FILE *file; 90 void (*error_func)(); 91 struct passwd *pw; 92 char **envp; 93{ 94 /* this function reads one crontab entry -- the next -- from a file. 95 * it skips any leading blank lines, ignores comments, and returns 96 * EOF if for any reason the entry can't be read and parsed. 97 * 98 * the entry is also parsed here. 99 * 100 * syntax: 101 * user crontab: 102 * minutes hours doms months dows cmd\n 103 * system crontab (/etc/crontab): 104 * minutes hours doms months dows USERNAME cmd\n 105 */ 106 107 ecode_e ecode = e_none; 108 entry *e; 109 int ch; 110 char cmd[MAX_COMMAND]; 111 char envstr[MAX_ENVSTR]; 112 char **prev_env; 113 114 Debug(DPARS, ("load_entry()...about to eat comments\n")) 115 116 skip_comments(file); 117 118 ch = get_char(file); 119 if (ch == EOF) 120 return NULL; 121 122 /* ch is now the first useful character of a useful line. 123 * it may be an @special or it may be the first character 124 * of a list of minutes. 125 */ 126 127 e = (entry *) calloc(sizeof(entry), sizeof(char)); 128 129 if (e == NULL) { 130 warn("load_entry: calloc failed"); 131 return NULL; 132 } 133 134 if (ch == '@') { 135 /* all of these should be flagged and load-limited; i.e., 136 * instead of @hourly meaning "0 * * * *" it should mean 137 * "close to the front of every hour but not 'til the 138 * system load is low". Problems are: how do you know 139 * what "low" means? (save me from /etc/cron.conf!) and: 140 * how to guarantee low variance (how low is low?), which 141 * means how to we run roughly every hour -- seems like 142 * we need to keep a history or let the first hour set 143 * the schedule, which means we aren't load-limited 144 * anymore. too much for my overloaded brain. (vix, jan90) 145 * HINT 146 */ 147 Debug(DPARS, ("load_entry()...about to test shortcuts\n")) 148 ch = get_string(cmd, MAX_COMMAND, file, " \t\n"); 149 if (!strcmp("reboot", cmd)) { 150 Debug(DPARS, ("load_entry()...reboot shortcut\n")) 151 e->flags |= WHEN_REBOOT; 152 } else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){ 153 Debug(DPARS, ("load_entry()...yearly shortcut\n")) 154 bit_set(e->minute, 0); 155 bit_set(e->hour, 0); 156 bit_set(e->dom, 0); 157 bit_set(e->month, 0); 158 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 159 e->flags |= DOW_STAR; 160 } else if (!strcmp("monthly", cmd)) { 161 Debug(DPARS, ("load_entry()...monthly shortcut\n")) 162 bit_set(e->minute, 0); 163 bit_set(e->hour, 0); 164 bit_set(e->dom, 0); 165 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 166 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 167 e->flags |= DOW_STAR; 168 } else if (!strcmp("weekly", cmd)) { 169 Debug(DPARS, ("load_entry()...weekly shortcut\n")) 170 bit_set(e->minute, 0); 171 bit_set(e->hour, 0); 172 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1)); 173 e->flags |= DOM_STAR; 174 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 175 bit_set(e->dow, 0); 176 } else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) { 177 Debug(DPARS, ("load_entry()...daily shortcut\n")) 178 bit_set(e->minute, 0); 179 bit_set(e->hour, 0); 180 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1)); 181 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 182 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 183 } else if (!strcmp("hourly", cmd)) { 184 Debug(DPARS, ("load_entry()...hourly shortcut\n")) 185 bit_set(e->minute, 0); 186 bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1)); 187 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1)); 188 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 189 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 190 } else { 191 ecode = e_timespec; 192 goto eof; 193 } 194 /* Advance past whitespace between shortcut and 195 * username/command. 196 */ 197 Skip_Blanks(ch, file); 198 if (ch == EOF) { 199 ecode = e_cmd; 200 goto eof; 201 } 202 } else { 203 Debug(DPARS, ("load_entry()...about to parse numerics\n")) 204 205 ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE, 206 PPC_NULL, ch, file); 207 if (ch == EOF) { 208 ecode = e_minute; 209 goto eof; 210 } 211 212 /* hours 213 */ 214 215 ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR, 216 PPC_NULL, ch, file); 217 if (ch == EOF) { 218 ecode = e_hour; 219 goto eof; 220 } 221 222 /* DOM (days of month) 223 */ 224 225 if (ch == '*') 226 e->flags |= DOM_STAR; 227 ch = get_list(e->dom, FIRST_DOM, LAST_DOM, 228 PPC_NULL, ch, file); 229 if (ch == EOF) { 230 ecode = e_dom; 231 goto eof; 232 } 233 234 /* month 235 */ 236 237 ch = get_list(e->month, FIRST_MONTH, LAST_MONTH, 238 MonthNames, ch, file); 239 if (ch == EOF) { 240 ecode = e_month; 241 goto eof; 242 } 243 244 /* DOW (days of week) 245 */ 246 247 if (ch == '*') 248 e->flags |= DOW_STAR; 249 ch = get_list(e->dow, FIRST_DOW, LAST_DOW, 250 DowNames, ch, file); 251 if (ch == EOF) { 252 ecode = e_dow; 253 goto eof; 254 } 255 } 256 257 /* make sundays equivilent */ 258 if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) { 259 bit_set(e->dow, 0); 260 bit_set(e->dow, 7); 261 } 262 263 /* ch is the first character of a command, or a username */ 264 unget_char(ch, file); 265 266 if (!pw) { 267 char *username = cmd; /* temp buffer */ 268 char *s; 269 struct group *grp; 270#ifdef LOGIN_CAP 271 login_cap_t *lc; 272#endif 273 274 Debug(DPARS, ("load_entry()...about to parse username\n")) 275 ch = get_string(username, MAX_COMMAND, file, " \t"); 276 277 Debug(DPARS, ("load_entry()...got %s\n",username)) 278 if (ch == EOF) { 279 ecode = e_cmd; 280 goto eof; 281 } 282 283#ifdef LOGIN_CAP 284 if ((s = strrchr(username, '/')) != NULL) { 285 *s = '\0'; 286 e->class = strdup(s + 1); 287 if (e->class == NULL) 288 warn("strdup(\"%s\")", s + 1); 289 } else { 290 e->class = strdup(RESOURCE_RC); 291 if (e->class == NULL) 292 warn("strdup(\"%s\")", RESOURCE_RC); 293 } 294 if (e->class == NULL) { 295 ecode = e_mem; 296 goto eof; 297 } 298 if ((lc = login_getclass(e->class)) == NULL) { 299 ecode = e_class; 300 goto eof; 301 } 302 login_close(lc); 303#endif 304 grp = NULL; 305 if ((s = strrchr(username, ':')) != NULL) { 306 *s = '\0'; 307 if ((grp = getgrnam(s + 1)) == NULL) { 308 ecode = e_group; 309 goto eof; 310 } 311 } 312 313 pw = getpwnam(username); 314 if (pw == NULL) { 315 ecode = e_username; 316 goto eof; 317 } 318 if (grp != NULL) 319 pw->pw_gid = grp->gr_gid; 320 Debug(DPARS, ("load_entry()...uid %d, gid %d\n",pw->pw_uid,pw->pw_gid)) 321#ifdef LOGIN_CAP 322 Debug(DPARS, ("load_entry()...class %s\n",e->class)) 323#endif 324 } 325 326 if (pw->pw_expire && time(NULL) >= pw->pw_expire) { 327 ecode = e_username; 328 goto eof; 329 } 330 331 e->uid = pw->pw_uid; 332 e->gid = pw->pw_gid; 333 334 /* copy and fix up environment. some variables are just defaults and 335 * others are overrides. 336 */ 337 e->envp = env_copy(envp); 338 if (e->envp == NULL) { 339 warn("env_copy"); 340 ecode = e_mem; 341 goto eof; 342 } 343 if (!env_get("SHELL", e->envp)) { 344 prev_env = e->envp; 345 sprintf(envstr, "SHELL=%s", _PATH_BSHELL); 346 e->envp = env_set(e->envp, envstr); 347 if (e->envp == NULL) { 348 warn("env_set(%s)", envstr); 349 env_free(prev_env); 350 ecode = e_mem; 351 goto eof; 352 } 353 } 354 prev_env = e->envp; 355 sprintf(envstr, "HOME=%s", pw->pw_dir); 356 e->envp = env_set(e->envp, envstr); 357 if (e->envp == NULL) { 358 warn("env_set(%s)", envstr); 359 env_free(prev_env); 360 ecode = e_mem; 361 goto eof; 362 } 363 if (!env_get("PATH", e->envp)) { 364 prev_env = e->envp; 365 sprintf(envstr, "PATH=%s", _PATH_DEFPATH); 366 e->envp = env_set(e->envp, envstr); 367 if (e->envp == NULL) { 368 warn("env_set(%s)", envstr); 369 env_free(prev_env); 370 ecode = e_mem; 371 goto eof; 372 } 373 } 374 prev_env = e->envp; 375 sprintf(envstr, "%s=%s", "LOGNAME", pw->pw_name); 376 e->envp = env_set(e->envp, envstr); 377 if (e->envp == NULL) { 378 warn("env_set(%s)", envstr); 379 env_free(prev_env); 380 ecode = e_mem; 381 goto eof; 382 } 383#if defined(BSD) 384 prev_env = e->envp; 385 sprintf(envstr, "%s=%s", "USER", pw->pw_name); 386 e->envp = env_set(e->envp, envstr); 387 if (e->envp == NULL) { 388 warn("env_set(%s)", envstr); 389 env_free(prev_env); 390 ecode = e_mem; 391 goto eof; 392 } 393#endif 394 395 Debug(DPARS, ("load_entry()...about to parse command\n")) 396 397 /* Everything up to the next \n or EOF is part of the command... 398 * too bad we don't know in advance how long it will be, since we 399 * need to malloc a string for it... so, we limit it to MAX_COMMAND. 400 * XXX - should use realloc(). 401 */ 402 ch = get_string(cmd, MAX_COMMAND, file, "\n"); 403 404 /* a file without a \n before the EOF is rude, so we'll complain... 405 */ 406 if (ch == EOF) { 407 ecode = e_cmd; 408 goto eof; 409 } 410 411 /* got the command in the 'cmd' string; save it in *e. 412 */ 413 e->cmd = strdup(cmd); 414 if (e->cmd == NULL) { 415 warn("strdup(\"%s\")", cmd); 416 ecode = e_mem; 417 goto eof; 418 } 419 Debug(DPARS, ("load_entry()...returning successfully\n")) 420 421 /* success, fini, return pointer to the entry we just created... 422 */ 423 return e; 424 425 eof: 426 free_entry(e); 427 if (ecode != e_none && error_func) 428 (*error_func)(ecodes[(int)ecode]); 429 while (ch != EOF && ch != '\n') 430 ch = get_char(file); 431 return NULL; 432} 433 434 435static char 436get_list(bits, low, high, names, ch, file) 437 bitstr_t *bits; /* one bit per flag, default=FALSE */ 438 int low, high; /* bounds, impl. offset for bitstr */ 439 char *names[]; /* NULL or *[] of names for these elements */ 440 int ch; /* current character being processed */ 441 FILE *file; /* file being read */ 442{ 443 register int done; 444 445 /* we know that we point to a non-blank character here; 446 * must do a Skip_Blanks before we exit, so that the 447 * next call (or the code that picks up the cmd) can 448 * assume the same thing. 449 */ 450 451 Debug(DPARS|DEXT, ("get_list()...entered\n")) 452 453 /* list = range {"," range} 454 */ 455 456 /* clear the bit string, since the default is 'off'. 457 */ 458 bit_nclear(bits, 0, (high-low+1)); 459 460 /* process all ranges 461 */ 462 done = FALSE; 463 while (!done) { 464 ch = get_range(bits, low, high, names, ch, file); 465 if (ch == ',') 466 ch = get_char(file); 467 else 468 done = TRUE; 469 } 470 471 /* exiting. skip to some blanks, then skip over the blanks. 472 */ 473 Skip_Nonblanks(ch, file) 474 Skip_Blanks(ch, file) 475 476 Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch)) 477 478 return ch; 479} 480 481 482static char 483get_range(bits, low, high, names, ch, file) 484 bitstr_t *bits; /* one bit per flag, default=FALSE */ 485 int low, high; /* bounds, impl. offset for bitstr */ 486 char *names[]; /* NULL or names of elements */ 487 int ch; /* current character being processed */ 488 FILE *file; /* file being read */ 489{ 490 /* range = number | number "-" number [ "/" number ] 491 */ 492 493 register int i; 494 auto int num1, num2, num3; 495 496 Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n")) 497 498 if (ch == '*') { 499 /* '*' means "first-last" but can still be modified by /step 500 */ 501 num1 = low; 502 num2 = high; 503 ch = get_char(file); 504 if (ch == EOF) 505 return EOF; 506 } else { 507 if (EOF == (ch = get_number(&num1, low, names, ch, file))) 508 return EOF; 509 510 if (ch != '-') { 511 /* not a range, it's a single number. 512 */ 513 if (EOF == set_element(bits, low, high, num1)) 514 return EOF; 515 return ch; 516 } else { 517 /* eat the dash 518 */ 519 ch = get_char(file); 520 if (ch == EOF) 521 return EOF; 522 523 /* get the number following the dash 524 */ 525 ch = get_number(&num2, low, names, ch, file); 526 if (ch == EOF) 527 return EOF; 528 } 529 } 530 531 /* check for step size 532 */ 533 if (ch == '/') { 534 /* eat the slash 535 */ 536 ch = get_char(file); 537 if (ch == EOF) 538 return EOF; 539 540 /* get the step size -- note: we don't pass the 541 * names here, because the number is not an 542 * element id, it's a step size. 'low' is 543 * sent as a 0 since there is no offset either. 544 */ 545 ch = get_number(&num3, 0, PPC_NULL, ch, file); 546 if (ch == EOF) 547 return EOF; 548 } else { 549 /* no step. default==1. 550 */ 551 num3 = 1; 552 } 553 554 /* range. set all elements from num1 to num2, stepping 555 * by num3. (the step is a downward-compatible extension 556 * proposed conceptually by bob@acornrc, syntactically 557 * designed then implmented by paul vixie). 558 */ 559 for (i = num1; i <= num2; i += num3) 560 if (EOF == set_element(bits, low, high, i)) 561 return EOF; 562 563 return ch; 564} 565 566 567static char 568get_number(numptr, low, names, ch, file) 569 int *numptr; /* where does the result go? */ 570 int low; /* offset applied to result if symbolic enum used */ 571 char *names[]; /* symbolic names, if any, for enums */ 572 int ch; /* current character */ 573 FILE *file; /* source */ 574{ 575 char temp[MAX_TEMPSTR], *pc; 576 int len, i, all_digits; 577 578 /* collect alphanumerics into our fixed-size temp array 579 */ 580 pc = temp; 581 len = 0; 582 all_digits = TRUE; 583 while (isalnum(ch)) { 584 if (++len >= MAX_TEMPSTR) 585 return EOF; 586 587 *pc++ = ch; 588 589 if (!isdigit(ch)) 590 all_digits = FALSE; 591 592 ch = get_char(file); 593 } 594 *pc = '\0'; 595 596 /* try to find the name in the name list 597 */ 598 if (names) { 599 for (i = 0; names[i] != NULL; i++) { 600 Debug(DPARS|DEXT, 601 ("get_num, compare(%s,%s)\n", names[i], temp)) 602 if (!strcasecmp(names[i], temp)) { 603 *numptr = i+low; 604 return ch; 605 } 606 } 607 } 608 609 /* no name list specified, or there is one and our string isn't 610 * in it. either way: if it's all digits, use its magnitude. 611 * otherwise, it's an error. 612 */ 613 if (all_digits) { 614 *numptr = atoi(temp); 615 return ch; 616 } 617 618 return EOF; 619} 620 621 622static int 623set_element(bits, low, high, number) 624 bitstr_t *bits; /* one bit per flag, default=FALSE */ 625 int low; 626 int high; 627 int number; 628{ 629 Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number)) 630 631 if (number < low || number > high) 632 return EOF; 633 634 bit_set(bits, (number-low)); 635 return OK; 636} 637