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 2009 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 * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
30 */
31
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35 #include <sys/wait.h>
36 #include <errno.h>
37 #include <signal.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <fcntl.h>
42 #include <ctype.h>
43 #include <pwd.h>
44 #include <unistd.h>
45 #include <locale.h>
46 #include <nl_types.h>
47 #include <langinfo.h>
48 #include <libintl.h>
49 #include <security/pam_appl.h>
50 #include <limits.h>
51 #include <libzoneinfo.h>
52 #include "cron.h"
53 #include "getresponse.h"
54
55 #if defined(XPG4)
56 #define VIPATH "/usr/xpg4/bin/vi"
57 #elif defined(XPG6)
58 #define VIPATH "/usr/xpg6/bin/vi"
59 #else
60 #define _XPG_NOTDEFINED
61 #define VIPATH "vi"
62 #endif
63
64 #define TMPFILE "_cron" /* prefix for tmp file */
65 #define CRMODE 0600 /* mode for creating crontabs */
66
67 #define BADCREATE \
68 "can't create your crontab file in the crontab directory."
69 #define BADOPEN "can't open your crontab file."
70 #define BADSHELL \
71 "because your login shell isn't /usr/bin/sh, you can't use cron."
72 #define WARNSHELL "warning: commands will be executed using /usr/bin/sh\n"
73 #define BADUSAGE \
74 "usage:\n" \
75 "\tcrontab [file]\n" \
76 "\tcrontab -e [username]\n" \
77 "\tcrontab -l [username]\n" \
78 "\tcrontab -r [username]"
79 #define INVALIDUSER "you are not a valid user (no entry in /etc/passwd)."
80 #define NOTALLOWED "you are not authorized to use cron. Sorry."
81 #define NOTROOT \
82 "you must be super-user to access another user's crontab file"
83 #define AUDITREJECT "The audit context for your shell has not been set."
84 #define EOLN "unexpected end of line."
85 #define UNEXPECT "unexpected character found in line."
86 #define OUTOFBOUND "number out of bounds."
87 #define OVERFLOW "too many elements."
88 #define ERRSFND "errors detected in input, no crontab file generated."
89 #define ED_ERROR \
90 " The editor indicates that an error occurred while you were\n"\
91 " editing the crontab data - usually a minor typing error.\n\n"
92 #define BADREAD "error reading your crontab file"
93 #define ED_PROMPT \
94 " Edit again, to ensure crontab information is intact (%s/%s)?\n"\
95 " ('%s' will discard edits.)"
96 #define NAMETOOLONG "login name too long"
97 #define BAD_TZ "Timezone unrecognized in: %s"
98 #define BAD_SHELL "Invalid shell specified: %s"
99 #define BAD_HOME "Unable to access directory: %s\t%s\n"
100
101 extern int per_errno;
102
103 extern int audit_crontab_modify(char *, char *, int);
104 extern int audit_crontab_delete(char *, int);
105 extern int audit_crontab_not_allowed(uid_t, char *);
106
107 int err;
108 int cursor;
109 char *cf;
110 char *tnam;
111 char edtemp[5+13+1];
112 char line[CTLINESIZE];
113 static char login[UNAMESIZE];
114
115 static void catch(int);
116 static void crabort(char *);
117 static void cerror(char *);
118 static void copycron(FILE *);
119
120 int
121 main(int argc, char **argv)
122 {
123 int c, r;
124 int rflag = 0;
125 int lflag = 0;
126 int eflag = 0;
127 int errflg = 0;
128 char *pp;
129 FILE *fp, *tmpfp;
130 struct stat stbuf;
131 struct passwd *pwp;
132 time_t omodtime;
133 char *editor;
134 uid_t ruid;
135 pid_t pid;
136 int stat_loc;
137 int ret;
138 char real_login[UNAMESIZE];
139 int tmpfd = -1;
140 pam_handle_t *pamh;
141 int pam_error;
142 char *buf;
143 size_t buflen;
144
145 (void) setlocale(LC_ALL, "");
146 #if !defined(TEXT_DOMAIN) /* Should be defined by cc -D */
147 #define TEXT_DOMAIN "SYS_TEST" /* Use this only if it weren't */
148 #endif
149 (void) textdomain(TEXT_DOMAIN);
150
151 if (init_yes() < 0) {
152 (void) fprintf(stderr, gettext(ERR_MSG_INIT_YES),
153 strerror(errno));
154 exit(1);
155 }
156
157 while ((c = getopt(argc, argv, "elr")) != EOF)
158 switch (c) {
159 case 'e':
160 eflag++;
161 break;
162 case 'l':
163 lflag++;
164 break;
165 case 'r':
166 rflag++;
167 break;
168 case '?':
169 errflg++;
170 break;
171 }
172
173 if (eflag + lflag + rflag > 1)
174 errflg++;
175
176 argc -= optind;
177 argv += optind;
178 if (errflg || argc > 1)
179 crabort(BADUSAGE);
180
181 ruid = getuid();
182 if ((pwp = getpwuid(ruid)) == NULL)
183 crabort(INVALIDUSER);
184
185 if (strlcpy(real_login, pwp->pw_name, sizeof (real_login))
186 >= sizeof (real_login))
187 crabort(NAMETOOLONG);
188
189 if ((eflag || lflag || rflag) && argc == 1) {
190 if ((pwp = getpwnam(*argv)) == NULL)
191 crabort(INVALIDUSER);
192
193 if (!cron_admin(real_login)) {
194 if (pwp->pw_uid != ruid)
195 crabort(NOTROOT);
196 else
197 pp = getuser(ruid);
198 } else
199 pp = *argv++;
200 } else {
201 pp = getuser(ruid);
202 }
203
204 if (pp == NULL) {
205 if (per_errno == 2)
206 crabort(BADSHELL);
207 else
208 crabort(INVALIDUSER);
209 }
210 if (strlcpy(login, pp, sizeof (login)) >= sizeof (login))
211 crabort(NAMETOOLONG);
212 if (!allowed(login, CRONALLOW, CRONDENY))
213 crabort(NOTALLOWED);
214
215 /* Do account validation check */
216 pam_error = pam_start("cron", pp, NULL, &pamh);
217 if (pam_error != PAM_SUCCESS) {
218 crabort((char *)pam_strerror(pamh, pam_error));
219 }
220 pam_error = pam_acct_mgmt(pamh, PAM_SILENT);
221 if (pam_error != PAM_SUCCESS) {
222 (void) fprintf(stderr, gettext("Warning - Invalid account: "
223 "'%s' not allowed to execute cronjobs\n"), pp);
224 }
225 (void) pam_end(pamh, PAM_SUCCESS);
226
227
228 /* check for unaudited shell */
229 if (audit_crontab_not_allowed(ruid, pp))
230 crabort(AUDITREJECT);
231
232 cf = xmalloc(strlen(CRONDIR)+strlen(login)+2);
233 strcat(strcat(strcpy(cf, CRONDIR), "/"), login);
234
235 if (rflag) {
236 r = unlink(cf);
237 cron_sendmsg(DELETE, login, login, CRON);
238 audit_crontab_delete(cf, r);
239 exit(0);
240 }
241 if (lflag) {
242 if ((fp = fopen(cf, "r")) == NULL)
243 crabort(BADOPEN);
244 while (fgets(line, CTLINESIZE, fp) != NULL)
245 fputs(line, stdout);
246 fclose(fp);
247 exit(0);
248 }
249 if (eflag) {
250 if ((fp = fopen(cf, "r")) == NULL) {
251 if (errno != ENOENT)
252 crabort(BADOPEN);
253 }
254 (void) strcpy(edtemp, "/tmp/crontabXXXXXX");
255 tmpfd = mkstemp(edtemp);
256 if (fchown(tmpfd, ruid, -1) == -1) {
257 (void) close(tmpfd);
258 crabort("fchown of temporary file failed");
259 }
260 (void) close(tmpfd);
261 /*
262 * Fork off a child with user's permissions,
263 * to edit the crontab file
264 */
265 if ((pid = fork()) == (pid_t)-1)
266 crabort("fork failed");
267 if (pid == 0) { /* child process */
268 /* give up super-user privileges. */
269 setuid(ruid);
270 if ((tmpfp = fopen(edtemp, "w")) == NULL)
271 crabort("can't create temporary file");
272 if (fp != NULL) {
273 /*
274 * Copy user's crontab file to temporary file.
275 */
276 while (fgets(line, CTLINESIZE, fp) != NULL) {
277 fputs(line, tmpfp);
278 if (ferror(tmpfp)) {
279 fclose(fp);
280 fclose(tmpfp);
281 crabort("write error on"
282 "temporary file");
283 }
284 }
285 if (ferror(fp)) {
286 fclose(fp);
287 fclose(tmpfp);
288 crabort(BADREAD);
289 }
290 fclose(fp);
291 }
292 if (fclose(tmpfp) == EOF)
293 crabort("write error on temporary file");
294 if (stat(edtemp, &stbuf) < 0)
295 crabort("can't stat temporary file");
296 omodtime = stbuf.st_mtime;
297 #ifdef _XPG_NOTDEFINED
298 editor = getenv("VISUAL");
299 if (editor == NULL) {
300 #endif
301 editor = getenv("EDITOR");
302 if (editor == NULL)
303 editor = VIPATH;
304 #ifdef _XPG_NOTDEFINED
305 }
306 #endif
307 buflen = strlen(editor) + strlen(edtemp) + 2;
308 buf = xmalloc(buflen);
309 (void) snprintf(buf, buflen, "%s %s", editor, edtemp);
310
311 sleep(1);
312
313 while (1) {
314 ret = system(buf);
315
316 /* sanity checks */
317 if ((tmpfp = fopen(edtemp, "r")) == NULL)
318 crabort("can't open temporary file");
319 if (fstat(fileno(tmpfp), &stbuf) < 0)
320 crabort("can't stat temporary file");
321 if (stbuf.st_size == 0)
322 crabort("temporary file empty");
323 if (omodtime == stbuf.st_mtime) {
324 (void) unlink(edtemp);
325 fprintf(stderr, gettext(
326 "The crontab file was not"
327 " changed.\n"));
328 exit(1);
329 }
330 if ((ret) && (errno != EINTR)) {
331 /*
332 * Some editors (like 'vi') can return
333 * a non-zero exit status even though
334 * everything is okay. Need to check.
335 */
336 fprintf(stderr, gettext(ED_ERROR));
337 fflush(stderr);
338 if (isatty(fileno(stdin))) {
339 /* Interactive */
340 fprintf(stdout,
341 gettext(ED_PROMPT),
342 yesstr, nostr, nostr);
343 fflush(stdout);
344
345 if (yes()) {
346 /* Edit again */
347 continue;
348 } else {
349 /* Dump changes */
350 (void) unlink(edtemp);
351 exit(1);
352 }
353 } else {
354 /*
355 * Non-interactive, dump changes
356 */
357 (void) unlink(edtemp);
358 exit(1);
359 }
360 }
361 exit(0);
362 } /* while (1) */
363 }
364
365 /* fix for 1125555 - ignore common signals while waiting */
366 (void) signal(SIGINT, SIG_IGN);
367 (void) signal(SIGHUP, SIG_IGN);
368 (void) signal(SIGQUIT, SIG_IGN);
369 (void) signal(SIGTERM, SIG_IGN);
370 wait(&stat_loc);
371 if ((stat_loc & 0xFF00) != 0)
372 exit(1);
373
374 /*
375 * unlink edtemp as 'ruid'. The file contents will be held
376 * since we open the file descriptor 'tmpfp' before calling
377 * unlink.
378 */
379 if (((ret = seteuid(ruid)) < 0) ||
380 ((tmpfp = fopen(edtemp, "r")) == NULL) ||
381 (unlink(edtemp) == -1)) {
382 fprintf(stderr, "crontab: %s: %s\n",
383 edtemp, errmsg(errno));
384 if ((ret < 0) || (tmpfp == NULL))
385 (void) unlink(edtemp);
386 exit(1);
387 } else
388 seteuid(0);
389
390 copycron(tmpfp);
391 } else {
392 if (argc == 0)
393 copycron(stdin);
394 else if (seteuid(getuid()) != 0 || (fp = fopen(argv[0], "r"))
395 == NULL)
396 crabort(BADOPEN);
397 else {
398 seteuid(0);
399 copycron(fp);
400 }
401 }
402 cron_sendmsg(ADD, login, login, CRON);
403 /*
404 * if (per_errno == 2)
405 * fprintf(stderr, gettext(WARNSHELL));
406 */
407 return (0);
408 }
409
410 static void
411 copycron(FILE *fp)
412 {
413 FILE *tfp;
414 char pid[6], *tnam_end;
415 int t;
416 char buf[LINE_MAX];
417 cferror_t cferr;
418
419 sprintf(pid, "%-5d", getpid());
420 tnam = xmalloc(strlen(CRONDIR)+strlen(TMPFILE)+7);
421 strcat(strcat(strcat(strcpy(tnam, CRONDIR), "/"), TMPFILE), pid);
422 /* cut trailing blanks */
423 tnam_end = strchr(tnam, ' ');
424 if (tnam_end != NULL)
425 *tnam_end = 0;
426 /* catch SIGINT, SIGHUP, SIGQUIT signals */
427 if (signal(SIGINT, catch) == SIG_IGN)
428 signal(SIGINT, SIG_IGN);
429 if (signal(SIGHUP, catch) == SIG_IGN) signal(SIGHUP, SIG_IGN);
430 if (signal(SIGQUIT, catch) == SIG_IGN) signal(SIGQUIT, SIG_IGN);
431 if (signal(SIGTERM, catch) == SIG_IGN) signal(SIGTERM, SIG_IGN);
432 if ((t = creat(tnam, CRMODE)) == -1) crabort(BADCREATE);
433 if ((tfp = fdopen(t, "w")) == NULL) {
434 unlink(tnam);
435 crabort(BADCREATE);
436 }
437 err = 0; /* if errors found, err set to 1 */
438 while (fgets(line, CTLINESIZE, fp) != NULL) {
439 cursor = 0;
440 while (line[cursor] == ' ' || line[cursor] == '\t')
441 cursor++;
442 /* fix for 1039689 - treat blank line like a comment */
443 if (line[cursor] == '#' || line[cursor] == '\n')
444 goto cont;
445
446 if (strncmp(&line[cursor], ENV_TZ, strlen(ENV_TZ)) == 0) {
447 char *x;
448
449 strncpy(buf, &line[cursor + strlen(ENV_TZ)],
450 sizeof (buf));
451 if ((x = strchr(buf, '\n')) != NULL)
452 *x = '\0';
453
454 if (isvalid_tz(buf, NULL, _VTZ_ALL)) {
455 goto cont;
456 } else {
457 err = 1;
458 fprintf(stderr, BAD_TZ, &line[cursor]);
459 continue;
460 }
461 } else if (strncmp(&line[cursor], ENV_SHELL,
462 strlen(ENV_SHELL)) == 0) {
463 char *x;
464
465 strncpy(buf, &line[cursor + strlen(ENV_SHELL)],
466 sizeof (buf));
467 if ((x = strchr(buf, '\n')) != NULL)
468 *x = '\0';
469
470 if (isvalid_shell(buf)) {
471 goto cont;
472 } else {
473 err = 1;
474 fprintf(stderr, BAD_SHELL, &line[cursor]);
475 continue;
476 }
477 } else if (strncmp(&line[cursor], ENV_HOME,
478 strlen(ENV_HOME)) == 0) {
479 char *x;
480
481 strncpy(buf, &line[cursor + strlen(ENV_HOME)],
482 sizeof (buf));
483 if ((x = strchr(buf, '\n')) != NULL)
484 *x = '\0';
485 if (chdir(buf) == 0) {
486 goto cont;
487 } else {
488 err = 1;
489 fprintf(stderr, BAD_HOME, &line[cursor],
490 strerror(errno));
491 continue;
492 }
493 }
494
495 if ((cferr = next_field(0, 59, line, &cursor, NULL)) != CFOK ||
496 (cferr = next_field(0, 23, line, &cursor, NULL)) != CFOK ||
497 (cferr = next_field(1, 31, line, &cursor, NULL)) != CFOK ||
498 (cferr = next_field(1, 12, line, &cursor, NULL)) != CFOK ||
499 (cferr = next_field(0, 6, line, &cursor, NULL)) != CFOK) {
500 switch (cferr) {
501 case CFEOLN:
502 cerror(EOLN);
503 break;
504 case CFUNEXPECT:
505 cerror(UNEXPECT);
506 break;
507 case CFOUTOFBOUND:
508 cerror(OUTOFBOUND);
509 break;
510 case CFEOVERFLOW:
511 cerror(OVERFLOW);
512 break;
513 case CFENOMEM:
514 (void) fprintf(stderr, "Out of memory\n");
515 exit(55);
516 break;
517 default:
518 break;
519 }
520 continue;
521 }
522
523 if (line[++cursor] == '\0') {
524 cerror(EOLN);
525 continue;
526 }
527 cont:
528 if (fputs(line, tfp) == EOF) {
529 unlink(tnam);
530 crabort(BADCREATE);
531 }
532 }
533 fclose(fp);
534 fclose(tfp);
535
536 /* audit differences between old and new crontabs */
537 audit_crontab_modify(cf, tnam, err);
538
539 if (!err) {
540 /* make file tfp the new crontab */
541 unlink(cf);
542 if (link(tnam, cf) == -1) {
543 unlink(tnam);
544 crabort(BADCREATE);
545 }
546 } else {
547 crabort(ERRSFND);
548 }
549 unlink(tnam);
550 }
551
552 static void
553 cerror(char *msg)
554 {
555 fprintf(stderr, gettext("%scrontab: error on previous line; %s\n"),
556 line, msg);
557 err = 1;
558 }
559
560
561 static void
562 catch(int x)
563 {
564 unlink(tnam);
565 exit(1);
566 }
567
568 static void
569 crabort(char *msg)
570 {
571 int sverrno;
572
573 if (strcmp(edtemp, "") != 0) {
574 sverrno = errno;
575 (void) unlink(edtemp);
576 errno = sverrno;
577 }
578 if (tnam != NULL) {
579 sverrno = errno;
580 (void) unlink(tnam);
581 errno = sverrno;
582 }
583 fprintf(stderr, "crontab: %s\n", gettext(msg));
584 exit(1);
585 }