1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 26 /* All Rights Reserved */ 27 28 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 #include <sys/types.h> 32 #include <sys/stat.h> 33 #include <sys/types.h> 34 #include <sys/wait.h> 35 #include <errno.h> 36 #include <signal.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <fcntl.h> 41 #include <ctype.h> 42 #include <pwd.h> 43 #include <unistd.h> 44 #include <locale.h> 45 #include <nl_types.h> 46 #include <langinfo.h> 47 #include <libintl.h> 48 #include <spawn.h> 49 #include <security/pam_appl.h> 50 #include "cron.h" 51 #include "getresponse.h" 52 53 #if defined(XPG4) 54 #define VIPATH "/usr/xpg4/bin/vi" 55 #elif defined(XPG6) 56 #define VIPATH "/usr/xpg6/bin/vi" 57 #else 58 #define _XPG_NOTDEFINED 59 #define VIPATH "vi" 60 #endif 61 62 #define TMPFILE "_cron" /* prefix for tmp file */ 63 #define CRMODE 0600 /* mode for creating crontabs */ 64 65 #define BADCREATE \ 66 "can't create your crontab file in the crontab directory." 67 #define BADOPEN "can't open your crontab file." 68 #define BADSHELL \ 69 "because your login shell isn't /usr/bin/sh, you can't use cron." 70 #define WARNSHELL "warning: commands will be executed using /usr/bin/sh\n" 71 #define BADUSAGE \ 72 "usage:\n" \ 73 "\tcrontab [file]\n" \ 74 "\tcrontab -e [username]\n" \ 75 "\tcrontab -l [username]\n" \ 76 "\tcrontab -r [username]" 77 #define INVALIDUSER "you are not a valid user (no entry in /etc/passwd)." 78 #define NOTALLOWED "you are not authorized to use cron. Sorry." 79 #define NOTROOT \ 80 "you must be super-user to access another user's crontab file" 81 #define AUDITREJECT "The audit context for your shell has not been set." 82 #define EOLN "unexpected end of line." 83 #define UNEXPECT "unexpected character found in line." 84 #define OUTOFBOUND "number out of bounds." 85 #define ERRSFND "errors detected in input, no crontab file generated." 86 #define ED_ERROR \ 87 " The editor indicates that an error occurred while you were\n"\ 88 " editing the crontab data - usually a minor typing error.\n\n" 89 #define BADREAD "error reading your crontab file" 90 #define ED_PROMPT \ 91 " Edit again, to ensure crontab information is intact (%s/%s)?\n"\ 92 " ('%s' will discard edits.)" 93 #define NAMETOOLONG "login name too long" 94 95 extern int per_errno; 96 extern char **environ; 97 98 extern int audit_crontab_modify(char *, char *, int); 99 extern int audit_crontab_delete(char *, int); 100 extern int audit_crontab_not_allowed(uid_t, char *); 101 102 int err; 103 int cursor; 104 char *cf; 105 char *tnam; 106 char edtemp[5+13+1]; 107 char line[CTLINESIZE]; 108 static char login[UNAMESIZE]; 109 110 static int next_field(int, int); 111 static void catch(int); 112 static void crabort(char *); 113 static void cerror(char *); 114 static void copycron(FILE *); 115 116 int 117 main(int argc, char **argv) 118 { 119 int c, r; 120 int rflag = 0; 121 int lflag = 0; 122 int eflag = 0; 123 int errflg = 0; 124 char *pp; 125 FILE *fp, *tmpfp; 126 struct stat stbuf; 127 struct passwd *pwp; 128 time_t omodtime; 129 char *editor; 130 uid_t ruid; 131 pid_t pid; 132 int stat_loc; 133 int ret; 134 char real_login[UNAMESIZE]; 135 int tmpfd = -1; 136 pam_handle_t *pamh; 137 int pam_error; 138 pid_t cpid; 139 int cstatus; 140 char *argvec[3]; 141 142 (void) setlocale(LC_ALL, ""); 143 #if !defined(TEXT_DOMAIN) /* Should be defined by cc -D */ 144 #define TEXT_DOMAIN "SYS_TEST" /* Use this only if it weren't */ 145 #endif 146 (void) textdomain(TEXT_DOMAIN); 147 148 if (init_yes() < 0) { 149 (void) fprintf(stderr, gettext(ERR_MSG_INIT_YES), 150 strerror(errno)); 151 exit(1); 152 } 153 154 while ((c = getopt(argc, argv, "elr")) != EOF) 155 switch (c) { 156 case 'e': 157 eflag++; 158 break; 159 case 'l': 160 lflag++; 161 break; 162 case 'r': 163 rflag++; 164 break; 165 case '?': 166 errflg++; 167 break; 168 } 169 170 if (eflag + lflag + rflag > 1) 171 errflg++; 172 173 argc -= optind; 174 argv += optind; 175 if (errflg || argc > 1) 176 crabort(BADUSAGE); 177 178 ruid = getuid(); 179 if ((pwp = getpwuid(ruid)) == NULL) 180 crabort(INVALIDUSER); 181 182 if (strlcpy(real_login, pwp->pw_name, sizeof (real_login)) 183 >= sizeof (real_login)) 184 crabort(NAMETOOLONG); 185 186 if ((eflag || lflag || rflag) && argc == 1) { 187 if ((pwp = getpwnam(*argv)) == NULL) 188 crabort(INVALIDUSER); 189 190 if (!chkauthattr(CRONADMIN_AUTH, real_login)) { 191 if (pwp->pw_uid != ruid) 192 crabort(NOTROOT); 193 else 194 pp = getuser(ruid); 195 } else 196 pp = *argv++; 197 } else { 198 pp = getuser(ruid); 199 } 200 201 if (pp == NULL) { 202 if (per_errno == 2) 203 crabort(BADSHELL); 204 else 205 crabort(INVALIDUSER); 206 } 207 if (strlcpy(login, pp, sizeof (login)) >= sizeof (login)) 208 crabort(NAMETOOLONG); 209 if (!allowed(login, CRONALLOW, CRONDENY)) 210 crabort(NOTALLOWED); 211 212 /* Do account validation check */ 213 pam_error = pam_start("cron", pp, NULL, &pamh); 214 if (pam_error != PAM_SUCCESS) { 215 crabort((char *)pam_strerror(pamh, pam_error)); 216 } 217 pam_error = pam_acct_mgmt(pamh, PAM_SILENT); 218 if (pam_error != PAM_SUCCESS) { 219 (void) fprintf(stderr, gettext("Warning - Invalid account: " 220 "'%s' not allowed to execute cronjobs\n"), pp); 221 } 222 (void) pam_end(pamh, PAM_SUCCESS); 223 224 225 /* check for unaudited shell */ 226 if (audit_crontab_not_allowed(ruid, pp)) 227 crabort(AUDITREJECT); 228 229 cf = xmalloc(strlen(CRONDIR)+strlen(login)+2); 230 strcat(strcat(strcpy(cf, CRONDIR), "/"), login); 231 232 if (rflag) { 233 r = unlink(cf); 234 cron_sendmsg(DELETE, login, login, CRON); 235 audit_crontab_delete(cf, r); 236 exit(0); 237 } 238 if (lflag) { 239 if ((fp = fopen(cf, "r")) == NULL) 240 crabort(BADOPEN); 241 while (fgets(line, CTLINESIZE, fp) != NULL) 242 fputs(line, stdout); 243 fclose(fp); 244 exit(0); 245 } 246 if (eflag) { 247 if ((fp = fopen(cf, "r")) == NULL) { 248 if (errno != ENOENT) 249 crabort(BADOPEN); 250 } 251 (void) strcpy(edtemp, "/tmp/crontabXXXXXX"); 252 tmpfd = mkstemp(edtemp); 253 if (fchown(tmpfd, ruid, -1) == -1) { 254 (void) close(tmpfd); 255 crabort("fchown of temporary file failed"); 256 } 257 (void) close(tmpfd); 258 /* 259 * Fork off a child with user's permissions, 260 * to edit the crontab file 261 */ 262 if ((pid = fork()) == (pid_t)-1) 263 crabort("fork failed"); 264 if (pid == 0) { /* child process */ 265 /* give up super-user privileges. */ 266 setuid(ruid); 267 if ((tmpfp = fopen(edtemp, "w")) == NULL) 268 crabort("can't create temporary file"); 269 if (fp != NULL) { 270 /* 271 * Copy user's crontab file to temporary file. 272 */ 273 while (fgets(line, CTLINESIZE, fp) != NULL) { 274 fputs(line, tmpfp); 275 if (ferror(tmpfp)) { 276 fclose(fp); 277 fclose(tmpfp); 278 crabort("write error on" 279 "temporary file"); 280 } 281 } 282 if (ferror(fp)) { 283 fclose(fp); 284 fclose(tmpfp); 285 crabort(BADREAD); 286 } 287 fclose(fp); 288 } 289 if (fclose(tmpfp) == EOF) 290 crabort("write error on temporary file"); 291 if (stat(edtemp, &stbuf) < 0) 292 crabort("can't stat temporary file"); 293 omodtime = stbuf.st_mtime; 294 #ifdef _XPG_NOTDEFINED 295 editor = getenv("VISUAL"); 296 if (editor == NULL) { 297 #endif 298 editor = getenv("EDITOR"); 299 if (editor == NULL) 300 editor = VIPATH; 301 #ifdef _XPG_NOTDEFINED 302 } 303 #endif 304 argvec[0] = strdup(editor); 305 argvec[1] = strdup(edtemp); 306 argvec[2] = NULL; 307 308 if (argvec[0] == NULL || argvec[1] == NULL) 309 crabort("Insufficient memory"); 310 311 sleep(1); 312 313 while (1) { 314 /* 315 * posix_spawnp() allows the file pointed to 316 * by the 'EDITOR' variable to be searched in 317 * the PATH environment variable 318 */ 319 320 ret = posix_spawnp(&cpid, editor, NULL, NULL, 321 (char *const *)argvec, 322 (char *const *)environ); 323 if (ret) { 324 (void) fprintf(stderr, 325 gettext("crontab: %s: %s\n"), 326 editor, strerror(errno)); 327 cstatus = -1; 328 } else { 329 pid_t wpid = 0; 330 while ((wpid = waitpid(cpid, &cstatus, 331 0)) == -1 && errno == EINTR) 332 ; 333 if (wpid == -1) 334 cstatus = -1; 335 } 336 337 /* sanity checks */ 338 if ((tmpfp = fopen(edtemp, "r")) == NULL) 339 crabort("can't open temporary file"); 340 if (fstat(fileno(tmpfp), &stbuf) < 0) 341 crabort("can't stat temporary file"); 342 if (stbuf.st_size == 0) 343 crabort("temporary file empty"); 344 if (omodtime == stbuf.st_mtime) { 345 (void) unlink(edtemp); 346 fprintf(stderr, gettext( 347 "The crontab file was not" 348 " changed.\n")); 349 exit(1); 350 } 351 if ((cstatus) && (errno != EINTR)) { 352 /* 353 * Some editors (like 'vi') can return 354 * a non-zero exit status even though 355 * everything is okay. Need to check. 356 */ 357 fprintf(stderr, gettext(ED_ERROR)); 358 fflush(stderr); 359 if (isatty(fileno(stdin))) { 360 /* Interactive */ 361 fprintf(stdout, 362 gettext(ED_PROMPT), 363 yesstr, nostr, nostr); 364 fflush(stdout); 365 366 if (yes()) { 367 /* Edit again */ 368 continue; 369 } else { 370 /* Dump changes */ 371 (void) unlink(edtemp); 372 exit(1); 373 } 374 } else { 375 /* 376 * Non-interactive, dump changes 377 */ 378 (void) unlink(edtemp); 379 exit(1); 380 } 381 } 382 exit(0); 383 } /* while (1) */ 384 } 385 386 /* fix for 1125555 - ignore common signals while waiting */ 387 (void) signal(SIGINT, SIG_IGN); 388 (void) signal(SIGHUP, SIG_IGN); 389 (void) signal(SIGQUIT, SIG_IGN); 390 (void) signal(SIGTERM, SIG_IGN); 391 wait(&stat_loc); 392 if ((stat_loc & 0xFF00) != 0) 393 exit(1); 394 395 /* 396 * unlink edtemp as 'ruid'. The file contents will be held 397 * since we open the file descriptor 'tmpfp' before calling 398 * unlink. 399 */ 400 if (((ret = seteuid(ruid)) < 0) || 401 ((tmpfp = fopen(edtemp, "r")) == NULL) || 402 (unlink(edtemp) == -1)) { 403 fprintf(stderr, "crontab: %s: %s\n", 404 edtemp, errmsg(errno)); 405 if ((ret < 0) || (tmpfp == NULL)) 406 (void) unlink(edtemp); 407 exit(1); 408 } else 409 seteuid(0); 410 411 copycron(tmpfp); 412 } else { 413 if (argc == 0) 414 copycron(stdin); 415 else if (seteuid(getuid()) != 0 || (fp = fopen(argv[0], "r")) 416 == NULL) 417 crabort(BADOPEN); 418 else { 419 seteuid(0); 420 copycron(fp); 421 } 422 } 423 cron_sendmsg(ADD, login, login, CRON); 424 /* 425 * if (per_errno == 2) 426 * fprintf(stderr, gettext(WARNSHELL)); 427 */ 428 return (0); 429 } 430 431 static void 432 copycron(fp) 433 FILE *fp; 434 { 435 FILE *tfp; 436 char pid[6], *tnam_end; 437 int t; 438 439 sprintf(pid, "%-5d", getpid()); 440 tnam = xmalloc(strlen(CRONDIR)+strlen(TMPFILE)+7); 441 strcat(strcat(strcat(strcpy(tnam, CRONDIR), "/"), TMPFILE), pid); 442 /* cut trailing blanks */ 443 tnam_end = strchr(tnam, ' '); 444 if (tnam_end != NULL) 445 *tnam_end = 0; 446 /* catch SIGINT, SIGHUP, SIGQUIT signals */ 447 if (signal(SIGINT, catch) == SIG_IGN) 448 signal(SIGINT, SIG_IGN); 449 if (signal(SIGHUP, catch) == SIG_IGN) signal(SIGHUP, SIG_IGN); 450 if (signal(SIGQUIT, catch) == SIG_IGN) signal(SIGQUIT, SIG_IGN); 451 if (signal(SIGTERM, catch) == SIG_IGN) signal(SIGTERM, SIG_IGN); 452 if ((t = creat(tnam, CRMODE)) == -1) crabort(BADCREATE); 453 if ((tfp = fdopen(t, "w")) == NULL) { 454 unlink(tnam); 455 crabort(BADCREATE); 456 } 457 err = 0; /* if errors found, err set to 1 */ 458 while (fgets(line, CTLINESIZE, fp) != NULL) { 459 cursor = 0; 460 while (line[cursor] == ' ' || line[cursor] == '\t') 461 cursor++; 462 /* fix for 1039689 - treat blank line like a comment */ 463 if (line[cursor] == '#' || line[cursor] == '\n') 464 goto cont; 465 if (next_field(0, 59)) continue; 466 if (next_field(0, 23)) continue; 467 if (next_field(1, 31)) continue; 468 if (next_field(1, 12)) continue; 469 if (next_field(0, 06)) continue; 470 if (line[++cursor] == '\0') { 471 cerror(EOLN); 472 continue; 473 } 474 cont: 475 if (fputs(line, tfp) == EOF) { 476 unlink(tnam); 477 crabort(BADCREATE); 478 } 479 } 480 fclose(fp); 481 fclose(tfp); 482 483 /* audit differences between old and new crontabs */ 484 audit_crontab_modify(cf, tnam, err); 485 486 if (!err) { 487 /* make file tfp the new crontab */ 488 unlink(cf); 489 if (link(tnam, cf) == -1) { 490 unlink(tnam); 491 crabort(BADCREATE); 492 } 493 } else 494 fprintf(stderr, "crontab: %s\n", gettext(ERRSFND)); 495 unlink(tnam); 496 } 497 498 static int 499 next_field(lower, upper) 500 int lower, upper; 501 { 502 int num, num2; 503 504 while ((line[cursor] == ' ') || (line[cursor] == '\t')) cursor++; 505 if (line[cursor] == '\0') { 506 cerror(EOLN); 507 return (1); 508 } 509 if (line[cursor] == '*') { 510 cursor++; 511 if ((line[cursor] != ' ') && (line[cursor] != '\t')) { 512 cerror(UNEXPECT); 513 return (1); 514 } 515 return (0); 516 } 517 while (TRUE) { 518 if (!isdigit(line[cursor])) { 519 cerror(UNEXPECT); 520 return (1); 521 } 522 num = 0; 523 do { 524 num = num*10 + (line[cursor]-'0'); 525 } while (isdigit(line[++cursor])); 526 if ((num < lower) || (num > upper)) { 527 cerror(OUTOFBOUND); 528 return (1); 529 } 530 if (line[cursor] == '-') { 531 if (!isdigit(line[++cursor])) { 532 cerror(UNEXPECT); 533 return (1); 534 } 535 num2 = 0; 536 do { 537 num2 = num2*10 + (line[cursor]-'0'); 538 } while (isdigit(line[++cursor])); 539 if ((num2 < lower) || (num2 > upper)) { 540 cerror(OUTOFBOUND); 541 return (1); 542 } 543 } 544 if ((line[cursor] == ' ') || (line[cursor] == '\t')) break; 545 if (line[cursor] == '\0') { 546 cerror(EOLN); 547 return (1); 548 } 549 if (line[cursor++] != ',') { 550 cerror(UNEXPECT); 551 return (1); 552 } 553 } 554 return (0); 555 } 556 557 static void 558 cerror(msg) 559 char *msg; 560 { 561 fprintf(stderr, gettext("%scrontab: error on previous line; %s\n"), 562 line, msg); 563 err = 1; 564 } 565 566 567 static void 568 catch(int x) 569 { 570 unlink(tnam); 571 exit(1); 572 } 573 574 static void 575 crabort(msg) 576 char *msg; 577 { 578 int sverrno; 579 580 if (strcmp(edtemp, "") != 0) { 581 sverrno = errno; 582 (void) unlink(edtemp); 583 errno = sverrno; 584 } 585 if (tnam != NULL) { 586 sverrno = errno; 587 (void) unlink(tnam); 588 errno = sverrno; 589 } 590 fprintf(stderr, "crontab: %s\n", gettext(msg)); 591 exit(1); 592 } 593