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 char rcsid[] = "$Id: entry.c,v 1.2 1995/04/12 19:04:26 ache Exp $"; 20 #endif 21 22 /* vix 26jan87 [RCS'd; rest of log is in RCS file] 23 * vix 01jan87 [added line-level error recovery] 24 * vix 31dec86 [added /step to the from-to range, per bob@acornrc] 25 * vix 30dec86 [written] 26 */ 27 28 29 #include "cron.h" 30 31 32 typedef enum ecode { 33 e_none, e_minute, e_hour, e_dom, e_month, e_dow, 34 e_cmd, e_timespec, e_username 35 } ecode_e; 36 37 static char get_list __P((bitstr_t *, int, int, char *[], int, FILE *)), 38 get_range __P((bitstr_t *, int, int, char *[], int, FILE *)), 39 get_number __P((int *, int, char *[], int, FILE *)); 40 static int set_element __P((bitstr_t *, int, int, int)); 41 42 static char *ecodes[] = 43 { 44 "no error", 45 "bad minute", 46 "bad hour", 47 "bad day-of-month", 48 "bad month", 49 "bad day-of-week", 50 "bad command", 51 "bad time specifier", 52 "bad username", 53 }; 54 55 56 void 57 free_entry(e) 58 entry *e; 59 { 60 free(e->cmd); 61 env_free(e->envp); 62 free(e); 63 } 64 65 66 /* return NULL if eof or syntax error occurs; 67 * otherwise return a pointer to a new entry. 68 */ 69 entry * 70 load_entry(file, error_func, pw, envp) 71 FILE *file; 72 void (*error_func)(); 73 struct passwd *pw; 74 char **envp; 75 { 76 /* this function reads one crontab entry -- the next -- from a file. 77 * it skips any leading blank lines, ignores comments, and returns 78 * EOF if for any reason the entry can't be read and parsed. 79 * 80 * the entry is also parsed here. 81 * 82 * syntax: 83 * user crontab: 84 * minutes hours doms months dows cmd\n 85 * system crontab (/etc/crontab): 86 * minutes hours doms months dows USERNAME cmd\n 87 */ 88 89 ecode_e ecode = e_none; 90 entry *e; 91 int ch; 92 char cmd[MAX_COMMAND]; 93 char envstr[MAX_ENVSTR]; 94 95 Debug(DPARS, ("load_entry()...about to eat comments\n")) 96 97 skip_comments(file); 98 99 ch = get_char(file); 100 if (ch == EOF) 101 return NULL; 102 103 /* ch is now the first useful character of a useful line. 104 * it may be an @special or it may be the first character 105 * of a list of minutes. 106 */ 107 108 e = (entry *) calloc(sizeof(entry), sizeof(char)); 109 110 if (ch == '@') { 111 /* all of these should be flagged and load-limited; i.e., 112 * instead of @hourly meaning "0 * * * *" it should mean 113 * "close to the front of every hour but not 'til the 114 * system load is low". Problems are: how do you know 115 * what "low" means? (save me from /etc/cron.conf!) and: 116 * how to guarantee low variance (how low is low?), which 117 * means how to we run roughly every hour -- seems like 118 * we need to keep a history or let the first hour set 119 * the schedule, which means we aren't load-limited 120 * anymore. too much for my overloaded brain. (vix, jan90) 121 * HINT 122 */ 123 ch = get_string(cmd, MAX_COMMAND, file, " \t\n"); 124 if (!strcmp("reboot", cmd)) { 125 e->flags |= WHEN_REBOOT; 126 } else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){ 127 bit_set(e->minute, 0); 128 bit_set(e->hour, 0); 129 bit_set(e->dom, 0); 130 bit_set(e->month, 0); 131 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 132 } else if (!strcmp("monthly", cmd)) { 133 bit_set(e->minute, 0); 134 bit_set(e->hour, 0); 135 bit_set(e->dom, 0); 136 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 137 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 138 } else if (!strcmp("weekly", cmd)) { 139 bit_set(e->minute, 0); 140 bit_set(e->hour, 0); 141 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1)); 142 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 143 bit_set(e->dow, 0); 144 } else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) { 145 bit_set(e->minute, 0); 146 bit_set(e->hour, 0); 147 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1)); 148 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 149 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 150 } else if (!strcmp("hourly", cmd)) { 151 bit_set(e->minute, 0); 152 bit_set(e->hour, (LAST_HOUR-FIRST_HOUR+1)); 153 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1)); 154 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1)); 155 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1)); 156 } else { 157 ecode = e_timespec; 158 goto eof; 159 } 160 } else { 161 Debug(DPARS, ("load_entry()...about to parse numerics\n")) 162 163 ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE, 164 PPC_NULL, ch, file); 165 if (ch == EOF) { 166 ecode = e_minute; 167 goto eof; 168 } 169 170 /* hours 171 */ 172 173 ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR, 174 PPC_NULL, ch, file); 175 if (ch == EOF) { 176 ecode = e_hour; 177 goto eof; 178 } 179 180 /* DOM (days of month) 181 */ 182 183 if (ch == '*') 184 e->flags |= DOM_STAR; 185 ch = get_list(e->dom, FIRST_DOM, LAST_DOM, 186 PPC_NULL, ch, file); 187 if (ch == EOF) { 188 ecode = e_dom; 189 goto eof; 190 } 191 192 /* month 193 */ 194 195 ch = get_list(e->month, FIRST_MONTH, LAST_MONTH, 196 MonthNames, ch, file); 197 if (ch == EOF) { 198 ecode = e_month; 199 goto eof; 200 } 201 202 /* DOW (days of week) 203 */ 204 205 if (ch == '*') 206 e->flags |= DOW_STAR; 207 ch = get_list(e->dow, FIRST_DOW, LAST_DOW, 208 DowNames, ch, file); 209 if (ch == EOF) { 210 ecode = e_dow; 211 goto eof; 212 } 213 } 214 215 /* make sundays equivilent */ 216 if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) { 217 bit_set(e->dow, 0); 218 bit_set(e->dow, 7); 219 } 220 221 /* ch is the first character of a command, or a username */ 222 unget_char(ch, file); 223 224 if (!pw) { 225 char *username = cmd; /* temp buffer */ 226 227 Debug(DPARS, ("load_entry()...about to parse username\n")) 228 ch = get_string(username, MAX_COMMAND, file, " \t"); 229 230 Debug(DPARS, ("load_entry()...got %s\n",username)) 231 if (ch == EOF) { 232 ecode = e_cmd; 233 goto eof; 234 } 235 236 pw = getpwnam(username); 237 if (pw == NULL) { 238 ecode = e_username; 239 goto eof; 240 } 241 Debug(DPARS, ("load_entry()...uid %d, gid %d\n",e->uid,e->gid)) 242 } 243 244 e->uid = pw->pw_uid; 245 e->gid = pw->pw_gid; 246 247 /* copy and fix up environment. some variables are just defaults and 248 * others are overrides. 249 */ 250 e->envp = env_copy(envp); 251 if (!env_get("SHELL", e->envp)) { 252 sprintf(envstr, "SHELL=%s", _PATH_BSHELL); 253 e->envp = env_set(e->envp, envstr); 254 } 255 sprintf(envstr, "HOME=%s", pw->pw_dir); 256 e->envp = env_set(e->envp, envstr); 257 if (!env_get("PATH", e->envp)) { 258 sprintf(envstr, "PATH=%s", _PATH_DEFPATH); 259 e->envp = env_set(e->envp, envstr); 260 } 261 sprintf(envstr, "%s=%s", "LOGNAME", pw->pw_name); 262 e->envp = env_set(e->envp, envstr); 263 #if defined(BSD) 264 sprintf(envstr, "%s=%s", "USER", pw->pw_name); 265 e->envp = env_set(e->envp, envstr); 266 #endif 267 268 Debug(DPARS, ("load_entry()...about to parse command\n")) 269 270 /* Everything up to the next \n or EOF is part of the command... 271 * too bad we don't know in advance how long it will be, since we 272 * need to malloc a string for it... so, we limit it to MAX_COMMAND. 273 * XXX - should use realloc(). 274 */ 275 ch = get_string(cmd, MAX_COMMAND, file, "\n"); 276 277 /* a file without a \n before the EOF is rude, so we'll complain... 278 */ 279 if (ch == EOF) { 280 ecode = e_cmd; 281 goto eof; 282 } 283 284 /* got the command in the 'cmd' string; save it in *e. 285 */ 286 e->cmd = strdup(cmd); 287 288 Debug(DPARS, ("load_entry()...returning successfully\n")) 289 290 /* success, fini, return pointer to the entry we just created... 291 */ 292 return e; 293 294 eof: 295 free(e); 296 if (ecode != e_none && error_func) 297 (*error_func)(ecodes[(int)ecode]); 298 while (ch != EOF && ch != '\n') 299 ch = get_char(file); 300 return NULL; 301 } 302 303 304 static char 305 get_list(bits, low, high, names, ch, file) 306 bitstr_t *bits; /* one bit per flag, default=FALSE */ 307 int low, high; /* bounds, impl. offset for bitstr */ 308 char *names[]; /* NULL or *[] of names for these elements */ 309 int ch; /* current character being processed */ 310 FILE *file; /* file being read */ 311 { 312 register int done; 313 314 /* we know that we point to a non-blank character here; 315 * must do a Skip_Blanks before we exit, so that the 316 * next call (or the code that picks up the cmd) can 317 * assume the same thing. 318 */ 319 320 Debug(DPARS|DEXT, ("get_list()...entered\n")) 321 322 /* list = range {"," range} 323 */ 324 325 /* clear the bit string, since the default is 'off'. 326 */ 327 bit_nclear(bits, 0, (high-low+1)); 328 329 /* process all ranges 330 */ 331 done = FALSE; 332 while (!done) { 333 ch = get_range(bits, low, high, names, ch, file); 334 if (ch == ',') 335 ch = get_char(file); 336 else 337 done = TRUE; 338 } 339 340 /* exiting. skip to some blanks, then skip over the blanks. 341 */ 342 Skip_Nonblanks(ch, file) 343 Skip_Blanks(ch, file) 344 345 Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch)) 346 347 return ch; 348 } 349 350 351 static char 352 get_range(bits, low, high, names, ch, file) 353 bitstr_t *bits; /* one bit per flag, default=FALSE */ 354 int low, high; /* bounds, impl. offset for bitstr */ 355 char *names[]; /* NULL or names of elements */ 356 int ch; /* current character being processed */ 357 FILE *file; /* file being read */ 358 { 359 /* range = number | number "-" number [ "/" number ] 360 */ 361 362 register int i; 363 auto int num1, num2, num3; 364 365 Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n")) 366 367 if (ch == '*') { 368 /* '*' means "first-last" but can still be modified by /step 369 */ 370 num1 = low; 371 num2 = high; 372 ch = get_char(file); 373 if (ch == EOF) 374 return EOF; 375 } else { 376 if (EOF == (ch = get_number(&num1, low, names, ch, file))) 377 return EOF; 378 379 if (ch != '-') { 380 /* not a range, it's a single number. 381 */ 382 if (EOF == set_element(bits, low, high, num1)) 383 return EOF; 384 return ch; 385 } else { 386 /* eat the dash 387 */ 388 ch = get_char(file); 389 if (ch == EOF) 390 return EOF; 391 392 /* get the number following the dash 393 */ 394 ch = get_number(&num2, low, names, ch, file); 395 if (ch == EOF) 396 return EOF; 397 } 398 } 399 400 /* check for step size 401 */ 402 if (ch == '/') { 403 /* eat the slash 404 */ 405 ch = get_char(file); 406 if (ch == EOF) 407 return EOF; 408 409 /* get the step size -- note: we don't pass the 410 * names here, because the number is not an 411 * element id, it's a step size. 'low' is 412 * sent as a 0 since there is no offset either. 413 */ 414 ch = get_number(&num3, 0, PPC_NULL, ch, file); 415 if (ch == EOF) 416 return EOF; 417 } else { 418 /* no step. default==1. 419 */ 420 num3 = 1; 421 } 422 423 /* range. set all elements from num1 to num2, stepping 424 * by num3. (the step is a downward-compatible extension 425 * proposed conceptually by bob@acornrc, syntactically 426 * designed then implmented by paul vixie). 427 */ 428 for (i = num1; i <= num2; i += num3) 429 if (EOF == set_element(bits, low, high, i)) 430 return EOF; 431 432 return ch; 433 } 434 435 436 static char 437 get_number(numptr, low, names, ch, file) 438 int *numptr; /* where does the result go? */ 439 int low; /* offset applied to result if symbolic enum used */ 440 char *names[]; /* symbolic names, if any, for enums */ 441 int ch; /* current character */ 442 FILE *file; /* source */ 443 { 444 char temp[MAX_TEMPSTR], *pc; 445 int len, i, all_digits; 446 447 /* collect alphanumerics into our fixed-size temp array 448 */ 449 pc = temp; 450 len = 0; 451 all_digits = TRUE; 452 while (isalnum(ch)) { 453 if (++len >= MAX_TEMPSTR) 454 return EOF; 455 456 *pc++ = ch; 457 458 if (!isdigit(ch)) 459 all_digits = FALSE; 460 461 ch = get_char(file); 462 } 463 *pc = '\0'; 464 465 /* try to find the name in the name list 466 */ 467 if (names) { 468 for (i = 0; names[i] != NULL; i++) { 469 Debug(DPARS|DEXT, 470 ("get_num, compare(%s,%s)\n", names[i], temp)) 471 if (!strcasecmp(names[i], temp)) { 472 *numptr = i+low; 473 return ch; 474 } 475 } 476 } 477 478 /* no name list specified, or there is one and our string isn't 479 * in it. either way: if it's all digits, use its magnitude. 480 * otherwise, it's an error. 481 */ 482 if (all_digits) { 483 *numptr = atoi(temp); 484 return ch; 485 } 486 487 return EOF; 488 } 489 490 491 static int 492 set_element(bits, low, high, number) 493 bitstr_t *bits; /* one bit per flag, default=FALSE */ 494 int low; 495 int high; 496 int number; 497 { 498 Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number)) 499 500 if (number < low || number > high) 501 return EOF; 502 503 bit_set(bits, (number-low)); 504 return OK; 505 } 506