Annotation of embedaddon/sudo/plugins/sudoers/visudo.c, revision 1.1.1.1
1.1 misho 1: /*
2: * Copyright (c) 1996, 1998-2005, 2007-2011
3: * Todd C. Miller <Todd.Miller@courtesan.com>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: *
17: * Sponsored in part by the Defense Advanced Research Projects
18: * Agency (DARPA) and Air Force Research Laboratory, Air Force
19: * Materiel Command, USAF, under agreement number F39502-99-1-0512.
20: */
21:
22: /*
23: * Lock the sudoers file for safe editing (ala vipw) and check for parse errors.
24: */
25:
26: #define _SUDO_MAIN
27:
28: #ifdef __TANDEM
29: # include <floss.h>
30: #endif
31:
32: #include <config.h>
33:
34: #include <sys/types.h>
35: #include <sys/param.h>
36: #include <sys/stat.h>
37: #include <sys/socket.h>
38: #include <sys/time.h>
39: #ifndef __TANDEM
40: # include <sys/file.h>
41: #endif
42: #include <sys/wait.h>
43: #include <stdio.h>
44: #ifdef STDC_HEADERS
45: # include <stdlib.h>
46: # include <stddef.h>
47: #else
48: # ifdef HAVE_STDLIB_H
49: # include <stdlib.h>
50: # endif
51: #endif /* STDC_HEADERS */
52: #ifdef HAVE_STRING_H
53: # include <string.h>
54: #endif /* HAVE_STRING_H */
55: #ifdef HAVE_STRINGS_H
56: # include <strings.h>
57: #endif /* HAVE_STRINGS_H */
58: #ifdef HAVE_UNISTD_H
59: #include <unistd.h>
60: #endif /* HAVE_UNISTD_H */
61: #include <stdarg.h>
62: #include <ctype.h>
63: #include <pwd.h>
64: #include <grp.h>
65: #include <signal.h>
66: #include <errno.h>
67: #include <fcntl.h>
68: #include <netinet/in.h>
69: #include <arpa/inet.h>
70: #include <netdb.h>
71: #if TIME_WITH_SYS_TIME
72: # include <time.h>
73: #endif
74: #ifdef HAVE_SETLOCALE
75: # include <locale.h>
76: #endif
77:
78: #include "sudoers.h"
79: #include "interfaces.h"
80: #include "parse.h"
81: #include "redblack.h"
82: #include "gettext.h"
83: #include "sudoers_version.h"
84: #include <gram.h>
85:
86: struct sudoersfile {
87: struct sudoersfile *prev, *next;
88: char *path;
89: char *tpath;
90: int fd;
91: int modified;
92: int doedit;
93: };
94: TQ_DECLARE(sudoersfile)
95:
96: /*
97: * Function prototypes
98: */
99: static void quit(int);
100: static char *get_args(char *);
101: static char *get_editor(char **);
102: static void get_hostname(void);
103: static char whatnow(void);
104: static int check_aliases(int, int);
105: static int check_syntax(char *, int, int);
106: static int edit_sudoers(struct sudoersfile *, char *, char *, int);
107: static int install_sudoers(struct sudoersfile *, int);
108: static int print_unused(void *, void *);
109: static int reparse_sudoers(char *, char *, int, int);
110: static int run_command(char *, char **);
111: static int visudo_printf(int msg_type, const char *fmt, ...);
112: static void setup_signals(void);
113: static void help(void) __attribute__((__noreturn__));
114: static void usage(int);
115:
116: void cleanup(int);
117:
118: extern void yyerror(const char *);
119: extern void yyrestart(FILE *);
120:
121: /*
122: * External globals exported by the parser
123: */
124: extern struct rbtree *aliases;
125: extern FILE *yyin;
126: extern char *sudoers, *errorfile;
127: extern int errorlineno, parse_error;
128: /* For getopt(3) */
129: extern char *optarg;
130: extern int optind;
131:
132: /*
133: * Globals
134: */
135: struct interface *interfaces;
136: struct sudo_user sudo_user;
137: struct passwd *list_pw;
138: sudo_printf_t sudo_printf = visudo_printf;
139: static struct sudoersfile_list sudoerslist;
140: static struct rbtree *alias_freelist;
141:
142: int
143: main(int argc, char *argv[])
144: {
145: struct sudoersfile *sp;
146: char *args, *editor, *sudoers_path;
147: int ch, checkonly, quiet, strict, oldperms;
148: #if defined(SUDO_DEVEL) && defined(__OpenBSD__)
149: extern char *malloc_options;
150: malloc_options = "AFGJPR";
151: #endif
152:
153: #if !defined(HAVE_GETPROGNAME) && !defined(HAVE___PROGNAME)
154: setprogname(argc > 0 ? argv[0] : "visudo");
155: #endif
156:
157: #ifdef HAVE_SETLOCALE
158: setlocale(LC_ALL, "");
159: #endif
160: bindtextdomain("sudoers", LOCALEDIR); /* XXX - should have visudo domain */
161: textdomain("sudoers");
162:
163: if (argc < 1)
164: usage(1);
165:
166: /*
167: * Arg handling.
168: */
169: checkonly = oldperms = quiet = strict = FALSE;
170: sudoers_path = _PATH_SUDOERS;
171: while ((ch = getopt(argc, argv, "Vcf:sq")) != -1) {
172: switch (ch) {
173: case 'V':
174: (void) printf(_("%s version %s\n"), getprogname(), PACKAGE_VERSION);
175: (void) printf(_("%s grammar version %d\n"), getprogname(), SUDOERS_GRAMMAR_VERSION);
176: exit(0);
177: case 'c':
178: checkonly++; /* check mode */
179: break;
180: case 'f':
181: sudoers_path = optarg; /* sudoers file path */
182: oldperms = TRUE;
183: break;
184: case 'h':
185: help();
186: break;
187: case 's':
188: strict++; /* strict mode */
189: break;
190: case 'q':
191: quiet++; /* quiet mode */
192: break;
193: default:
194: usage(1);
195: }
196: }
197: argc -= optind;
198: argv += optind;
199: if (argc)
200: usage(1);
201:
202: sudo_setpwent();
203: sudo_setgrent();
204:
205: /* Mock up a fake sudo_user struct. */
206: user_cmnd = "";
207: if ((sudo_user.pw = sudo_getpwuid(getuid())) == NULL)
208: errorx(1, _("you do not exist in the %s database"), "passwd");
209: get_hostname();
210:
211: /* Setup defaults data structures. */
212: init_defaults();
213:
214: if (checkonly)
215: exit(check_syntax(sudoers_path, quiet, strict));
216:
217: /*
218: * Parse the existing sudoers file(s) in quiet mode to highlight any
219: * existing errors and to pull in editor and env_editor conf values.
220: */
221: if ((yyin = open_sudoers(sudoers_path, TRUE, NULL)) == NULL) {
222: error(1, "%s", sudoers_path);
223: }
224: init_parser(sudoers_path, 0);
225: yyparse();
226: (void) update_defaults(SETDEF_GENERIC|SETDEF_HOST|SETDEF_USER);
227:
228: editor = get_editor(&args);
229:
230: /* Install signal handlers to clean up temp files if we are killed. */
231: setup_signals();
232:
233: /* Edit the sudoers file(s) */
234: tq_foreach_fwd(&sudoerslist, sp) {
235: if (!sp->doedit)
236: continue;
237: if (sp != tq_first(&sudoerslist)) {
238: printf(_("press return to edit %s: "), sp->path);
239: while ((ch = getchar()) != EOF && ch != '\n')
240: continue;
241: }
242: edit_sudoers(sp, editor, args, -1);
243: }
244:
245: /* Check edited files for a parse error and re-edit any that fail. */
246: reparse_sudoers(editor, args, strict, quiet);
247:
248: /* Install the sudoers temp files. */
249: tq_foreach_fwd(&sudoerslist, sp) {
250: if (!sp->modified)
251: (void) unlink(sp->tpath);
252: else
253: (void) install_sudoers(sp, oldperms);
254: }
255:
256: exit(0);
257: }
258:
259: /*
260: * List of editors that support the "+lineno" command line syntax.
261: * If an entry starts with '*' the tail end of the string is matched.
262: * No other wild cards are supported.
263: */
264: static char *lineno_editors[] = {
265: "ex",
266: "nex",
267: "vi",
268: "nvi",
269: "vim",
270: "elvis",
271: "*macs",
272: "mg",
273: "vile",
274: "jove",
275: "pico",
276: "nano",
277: "ee",
278: "joe",
279: "zile",
280: NULL
281: };
282:
283: /*
284: * Edit each sudoers file.
285: * Returns TRUE on success, else FALSE.
286: */
287: static int
288: edit_sudoers(struct sudoersfile *sp, char *editor, char *args, int lineno)
289: {
290: int tfd; /* sudoers temp file descriptor */
291: int modified; /* was the file modified? */
292: int ac; /* argument count */
293: char **av; /* argument vector for run_command */
294: char *cp; /* scratch char pointer */
295: char buf[PATH_MAX*2]; /* buffer used for copying files */
296: char linestr[64]; /* string version of lineno */
297: struct timeval tv, tv1, tv2; /* time before and after edit */
298: struct timeval orig_mtim; /* starting mtime of sudoers file */
299: off_t orig_size; /* starting size of sudoers file */
300: ssize_t nread; /* number of bytes read */
301: struct stat sb; /* stat buffer */
302:
303: if (fstat(sp->fd, &sb) == -1)
304: error(1, _("unable to stat %s"), sp->path);
305: orig_size = sb.st_size;
306: mtim_get(&sb, &orig_mtim);
307:
308: /* Create the temp file if needed and set timestamp. */
309: if (sp->tpath == NULL) {
310: easprintf(&sp->tpath, "%s.tmp", sp->path);
311: tfd = open(sp->tpath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
312: if (tfd < 0)
313: error(1, "%s", sp->tpath);
314:
315: /* Copy sp->path -> sp->tpath and reset the mtime. */
316: if (orig_size != 0) {
317: (void) lseek(sp->fd, (off_t)0, SEEK_SET);
318: while ((nread = read(sp->fd, buf, sizeof(buf))) > 0)
319: if (write(tfd, buf, nread) != nread)
320: error(1, _("write error"));
321:
322: /* Add missing newline at EOF if needed. */
323: if (nread > 0 && buf[nread - 1] != '\n') {
324: buf[0] = '\n';
325: if (write(tfd, buf, 1) != 1)
326: error(1, _("write error"));
327: }
328: }
329: (void) close(tfd);
330: }
331: (void) touch(-1, sp->tpath, &orig_mtim);
332:
333: /* Does the editor support +lineno? */
334: if (lineno > 0)
335: {
336: char *editor_base = strrchr(editor, '/');
337: if (editor_base != NULL)
338: editor_base++;
339: else
340: editor_base = editor;
341: if (*editor_base == 'r')
342: editor_base++;
343:
344: for (av = lineno_editors; (cp = *av) != NULL; av++) {
345: /* We only handle a leading '*' wildcard. */
346: if (*cp == '*') {
347: size_t blen = strlen(editor_base);
348: size_t clen = strlen(++cp);
349: if (blen >= clen) {
350: if (strcmp(cp, editor_base + blen - clen) == 0)
351: break;
352: }
353: } else if (strcmp(cp, editor_base) == 0)
354: break;
355: }
356: /* Disable +lineno if editor doesn't support it. */
357: if (cp == NULL)
358: lineno = -1;
359: }
360:
361: /* Find the length of the argument vector */
362: ac = 3 + (lineno > 0);
363: if (args) {
364: int wasblank;
365:
366: ac++;
367: for (wasblank = FALSE, cp = args; *cp; cp++) {
368: if (isblank((unsigned char) *cp))
369: wasblank = TRUE;
370: else if (wasblank) {
371: wasblank = FALSE;
372: ac++;
373: }
374: }
375: }
376:
377: /* Build up argument vector for the command */
378: av = emalloc2(ac, sizeof(char *));
379: if ((av[0] = strrchr(editor, '/')) != NULL)
380: av[0]++;
381: else
382: av[0] = editor;
383: ac = 1;
384: if (lineno > 0) {
385: (void) snprintf(linestr, sizeof(linestr), "+%d", lineno);
386: av[ac++] = linestr;
387: }
388: if (args) {
389: for ((cp = strtok(args, " \t")); cp; (cp = strtok(NULL, " \t")))
390: av[ac++] = cp;
391: }
392: av[ac++] = sp->tpath;
393: av[ac++] = NULL;
394:
395: /*
396: * Do the edit:
397: * We cannot check the editor's exit value against 0 since
398: * XPG4 specifies that vi's exit value is a function of the
399: * number of errors during editing (?!?!).
400: */
401: gettimeofday(&tv1, NULL);
402: if (run_command(editor, av) != -1) {
403: gettimeofday(&tv2, NULL);
404: /*
405: * Sanity checks.
406: */
407: if (stat(sp->tpath, &sb) < 0) {
408: warningx(_("unable to stat temporary file (%s), %s unchanged"),
409: sp->tpath, sp->path);
410: return FALSE;
411: }
412: if (sb.st_size == 0 && orig_size != 0) {
413: warningx(_("zero length temporary file (%s), %s unchanged"),
414: sp->tpath, sp->path);
415: sp->modified = TRUE;
416: return FALSE;
417: }
418: } else {
419: warningx(_("editor (%s) failed, %s unchanged"), editor, sp->path);
420: return FALSE;
421: }
422:
423: /* Set modified bit if use changed the file. */
424: modified = TRUE;
425: mtim_get(&sb, &tv);
426: if (orig_size == sb.st_size && timevalcmp(&orig_mtim, &tv, ==)) {
427: /*
428: * If mtime and size match but the user spent no measurable
429: * time in the editor we can't tell if the file was changed.
430: */
431: timevalsub(&tv1, &tv2);
432: if (timevalisset(&tv2))
433: modified = FALSE;
434: }
435:
436: /*
437: * If modified in this edit session, mark as modified.
438: */
439: if (modified)
440: sp->modified = modified;
441: else
442: warningx(_("%s unchanged"), sp->tpath);
443:
444: return TRUE;
445: }
446:
447: /*
448: * Parse sudoers after editing and re-edit any ones that caused a parse error.
449: * Returns TRUE on success, else FALSE.
450: */
451: static int
452: reparse_sudoers(char *editor, char *args, int strict, int quiet)
453: {
454: struct sudoersfile *sp, *last;
455: FILE *fp;
456: int ch;
457:
458: /*
459: * Parse the edited sudoers files and do sanity checking
460: */
461: do {
462: sp = tq_first(&sudoerslist);
463: last = tq_last(&sudoerslist);
464: fp = fopen(sp->tpath, "r+");
465: if (fp == NULL)
466: errorx(1, _("unable to re-open temporary file (%s), %s unchanged."),
467: sp->tpath, sp->path);
468:
469: /* Clean slate for each parse */
470: init_defaults();
471: init_parser(sp->path, quiet);
472:
473: /* Parse the sudoers temp file */
474: yyrestart(fp);
475: if (yyparse() && !parse_error) {
476: warningx(_("unabled to parse temporary file (%s), unknown error"),
477: sp->tpath);
478: parse_error = TRUE;
479: errorfile = sp->path;
480: }
481: fclose(yyin);
482: if (!parse_error) {
483: if (!update_defaults(SETDEF_GENERIC|SETDEF_HOST|SETDEF_USER) ||
484: check_aliases(strict, quiet) != 0) {
485: parse_error = TRUE;
486: errorfile = sp->path;
487: }
488: }
489:
490: /*
491: * Got an error, prompt the user for what to do now
492: */
493: if (parse_error) {
494: switch (whatnow()) {
495: case 'Q' : parse_error = FALSE; /* ignore parse error */
496: break;
497: case 'x' : cleanup(0);
498: exit(0);
499: break;
500: }
501: }
502: if (parse_error) {
503: /* Edit file with the parse error */
504: tq_foreach_fwd(&sudoerslist, sp) {
505: if (errorfile == NULL || strcmp(sp->path, errorfile) == 0) {
506: edit_sudoers(sp, editor, args, errorlineno);
507: break;
508: }
509: }
510: if (sp == NULL) {
511: errorx(1, _("internal error, unable to find %s in list!"),
512: sudoers);
513: }
514: }
515:
516: /* If any new #include directives were added, edit them too. */
517: for (sp = last->next; sp != NULL; sp = sp->next) {
518: printf(_("press return to edit %s: "), sp->path);
519: while ((ch = getchar()) != EOF && ch != '\n')
520: continue;
521: edit_sudoers(sp, editor, args, errorlineno);
522: }
523: } while (parse_error);
524:
525: return TRUE;
526: }
527:
528: /*
529: * Set the owner and mode on a sudoers temp file and
530: * move it into place. Returns TRUE on success, else FALSE.
531: */
532: static int
533: install_sudoers(struct sudoersfile *sp, int oldperms)
534: {
535: struct stat sb;
536:
537: /*
538: * Change mode and ownership of temp file so when
539: * we move it to sp->path things are kosher.
540: */
541: if (oldperms) {
542: /* Use perms of the existing file. */
543: if (fstat(sp->fd, &sb) == -1)
544: error(1, _("unable to stat %s"), sp->path);
545: if (chown(sp->tpath, sb.st_uid, sb.st_gid) != 0) {
546: warning(_("unable to set (uid, gid) of %s to (%u, %u)"),
547: sp->tpath, (unsigned int)sb.st_uid, (unsigned int)sb.st_gid);
548: }
549: if (chmod(sp->tpath, sb.st_mode & 0777) != 0) {
550: warning(_("unable to change mode of %s to 0%o"), sp->tpath,
551: (unsigned int)(sb.st_mode & 0777));
552: }
553: } else {
554: if (chown(sp->tpath, SUDOERS_UID, SUDOERS_GID) != 0) {
555: warning(_("unable to set (uid, gid) of %s to (%u, %u)"),
556: sp->tpath, SUDOERS_UID, SUDOERS_GID);
557: return FALSE;
558: }
559: if (chmod(sp->tpath, SUDOERS_MODE) != 0) {
560: warning(_("unable to change mode of %s to 0%o"), sp->tpath,
561: SUDOERS_MODE);
562: return FALSE;
563: }
564: }
565:
566: /*
567: * Now that sp->tpath is sane (parses ok) it needs to be
568: * rename(2)'d to sp->path. If the rename(2) fails we try using
569: * mv(1) in case sp->tpath and sp->path are on different file systems.
570: */
571: if (rename(sp->tpath, sp->path) == 0) {
572: efree(sp->tpath);
573: sp->tpath = NULL;
574: } else {
575: if (errno == EXDEV) {
576: char *av[4];
577: warningx(_("%s and %s not on the same file system, using mv to rename"),
578: sp->tpath, sp->path);
579:
580: /* Build up argument vector for the command */
581: if ((av[0] = strrchr(_PATH_MV, '/')) != NULL)
582: av[0]++;
583: else
584: av[0] = _PATH_MV;
585: av[1] = sp->tpath;
586: av[2] = sp->path;
587: av[3] = NULL;
588:
589: /* And run it... */
590: if (run_command(_PATH_MV, av)) {
591: warningx(_("command failed: '%s %s %s', %s unchanged"),
592: _PATH_MV, sp->tpath, sp->path, sp->path);
593: (void) unlink(sp->tpath);
594: efree(sp->tpath);
595: sp->tpath = NULL;
596: return FALSE;
597: }
598: efree(sp->tpath);
599: sp->tpath = NULL;
600: } else {
601: warning(_("error renaming %s, %s unchanged"), sp->tpath, sp->path);
602: (void) unlink(sp->tpath);
603: return FALSE;
604: }
605: }
606: return TRUE;
607: }
608:
609: /* STUB */
610: void
611: set_fqdn(void)
612: {
613: return;
614: }
615:
616: /* STUB */
617: void
618: init_envtables(void)
619: {
620: return;
621: }
622:
623: /* STUB */
624: int
625: user_is_exempt(void)
626: {
627: return FALSE;
628: }
629:
630: /* STUB */
631: void
632: sudo_setspent(void)
633: {
634: return;
635: }
636:
637: /* STUB */
638: void
639: sudo_endspent(void)
640: {
641: return;
642: }
643:
644: /* STUB */
645: int
646: group_plugin_query(const char *user, const char *group, const struct passwd *pw)
647: {
648: return FALSE;
649: }
650:
651: /*
652: * Assuming a parse error occurred, prompt the user for what they want
653: * to do now. Returns the first letter of their choice.
654: */
655: static char
656: whatnow(void)
657: {
658: int choice, c;
659:
660: for (;;) {
661: (void) fputs(_("What now? "), stdout);
662: choice = getchar();
663: for (c = choice; c != '\n' && c != EOF;)
664: c = getchar();
665:
666: switch (choice) {
667: case EOF:
668: choice = 'x';
669: /* FALLTHROUGH */
670: case 'e':
671: case 'x':
672: case 'Q':
673: return choice;
674: default:
675: (void) puts(_("Options are:\n"
676: " (e)dit sudoers file again\n"
677: " e(x)it without saving changes to sudoers file\n"
678: " (Q)uit and save changes to sudoers file (DANGER!)\n"));
679: }
680: }
681: }
682:
683: /*
684: * Install signal handlers for visudo.
685: */
686: static void
687: setup_signals(void)
688: {
689: sigaction_t sa;
690:
691: /*
692: * Setup signal handlers to cleanup nicely.
693: */
694: zero_bytes(&sa, sizeof(sa));
695: sigemptyset(&sa.sa_mask);
696: sa.sa_flags = SA_RESTART;
697: sa.sa_handler = quit;
698: (void) sigaction(SIGTERM, &sa, NULL);
699: (void) sigaction(SIGHUP, &sa, NULL);
700: (void) sigaction(SIGINT, &sa, NULL);
701: (void) sigaction(SIGQUIT, &sa, NULL);
702: }
703:
704: static int
705: run_command(char *path, char **argv)
706: {
707: int status;
708: pid_t pid, rv;
709:
710: switch (pid = fork()) {
711: case -1:
712: error(1, _("unable to execute %s"), path);
713: break; /* NOTREACHED */
714: case 0:
715: sudo_endpwent();
716: sudo_endgrent();
717: closefrom(STDERR_FILENO + 1);
718: execv(path, argv);
719: warning(_("unable to run %s"), path);
720: _exit(127);
721: break; /* NOTREACHED */
722: }
723:
724: do {
725: rv = waitpid(pid, &status, 0);
726: } while (rv == -1 && errno == EINTR);
727:
728: if (rv == -1 || !WIFEXITED(status))
729: return -1;
730: return WEXITSTATUS(status);
731: }
732:
733: static int
734: check_syntax(char *sudoers_path, int quiet, int strict)
735: {
736: struct stat sb;
737: int error;
738:
739: if (strcmp(sudoers_path, "-") == 0) {
740: yyin = stdin;
741: sudoers_path = "stdin";
742: } else if ((yyin = fopen(sudoers_path, "r")) == NULL) {
743: if (!quiet)
744: warning(_("unable to open %s"), sudoers_path);
745: exit(1);
746: }
747: init_parser(sudoers_path, quiet);
748: if (yyparse() && !parse_error) {
749: if (!quiet)
750: warningx(_("failed to parse %s file, unknown error"), sudoers_path);
751: parse_error = TRUE;
752: errorfile = sudoers_path;
753: }
754: if (!parse_error && check_aliases(strict, quiet) != 0) {
755: parse_error = TRUE;
756: errorfile = sudoers_path;
757: }
758: error = parse_error;
759: if (!quiet) {
760: if (parse_error) {
761: if (errorlineno != -1)
762: (void) printf(_("parse error in %s near line %d\n"),
763: errorfile, errorlineno);
764: else
765: (void) printf(_("parse error in %s\n"), errorfile);
766: } else {
767: (void) printf(_("%s: parsed OK\n"), sudoers_path);
768: }
769: }
770: /* Check mode and owner in strict mode. */
771: if (strict && yyin != stdin && fstat(fileno(yyin), &sb) == 0) {
772: if (sb.st_uid != SUDOERS_UID || sb.st_gid != SUDOERS_GID) {
773: error = TRUE;
774: if (!quiet) {
775: fprintf(stderr,
776: _("%s: wrong owner (uid, gid) should be (%u, %u)\n"),
777: sudoers_path, SUDOERS_UID, SUDOERS_GID);
778: }
779: }
780: if ((sb.st_mode & 07777) != SUDOERS_MODE) {
781: error = TRUE;
782: if (!quiet) {
783: fprintf(stderr, _("%s: bad permissions, should be mode 0%o\n"),
784: sudoers_path, SUDOERS_MODE);
785: }
786: }
787: }
788:
789: return error;
790: }
791:
792: /*
793: * Used to open (and lock) the initial sudoers file and to also open
794: * any subsequent files #included via a callback from the parser.
795: */
796: FILE *
797: open_sudoers(const char *path, int doedit, int *keepopen)
798: {
799: struct sudoersfile *entry;
800: FILE *fp;
801:
802: /* Check for existing entry */
803: tq_foreach_fwd(&sudoerslist, entry) {
804: if (strcmp(path, entry->path) == 0)
805: break;
806: }
807: if (entry == NULL) {
808: entry = emalloc(sizeof(*entry));
809: entry->path = estrdup(path);
810: entry->modified = 0;
811: entry->prev = entry;
812: entry->next = NULL;
813: entry->fd = open(entry->path, O_RDWR | O_CREAT, SUDOERS_MODE);
814: entry->tpath = NULL;
815: entry->doedit = doedit;
816: if (entry->fd == -1) {
817: warning("%s", entry->path);
818: efree(entry);
819: return NULL;
820: }
821: if (!lock_file(entry->fd, SUDO_TLOCK))
822: errorx(1, _("%s busy, try again later"), entry->path);
823: if ((fp = fdopen(entry->fd, "r")) == NULL)
824: error(1, "%s", entry->path);
825: tq_append(&sudoerslist, entry);
826: } else {
827: /* Already exists, open .tmp version if there is one. */
828: if (entry->tpath != NULL) {
829: if ((fp = fopen(entry->tpath, "r")) == NULL)
830: error(1, "%s", entry->tpath);
831: } else {
832: if ((fp = fdopen(entry->fd, "r")) == NULL)
833: error(1, "%s", entry->path);
834: rewind(fp);
835: }
836: }
837: if (keepopen != NULL)
838: *keepopen = TRUE;
839: return fp;
840: }
841:
842: static char *
843: get_editor(char **args)
844: {
845: char *Editor, *EditorArgs, *EditorPath, *UserEditor, *UserEditorArgs;
846:
847: /*
848: * Check VISUAL and EDITOR environment variables to see which editor
849: * the user wants to use (we may not end up using it though).
850: * If the path is not fully-qualified, make it so and check that
851: * the specified executable actually exists.
852: */
853: UserEditorArgs = NULL;
854: if ((UserEditor = getenv("VISUAL")) == NULL || *UserEditor == '\0')
855: UserEditor = getenv("EDITOR");
856: if (UserEditor && *UserEditor == '\0')
857: UserEditor = NULL;
858: else if (UserEditor) {
859: UserEditorArgs = get_args(UserEditor);
860: if (find_path(UserEditor, &Editor, NULL, getenv("PATH"), 0) == FOUND) {
861: UserEditor = Editor;
862: } else {
863: if (def_env_editor) {
864: /* If we are honoring $EDITOR this is a fatal error. */
865: errorx(1, _("specified editor (%s) doesn't exist"), UserEditor);
866: } else {
867: /* Otherwise, just ignore $EDITOR. */
868: UserEditor = NULL;
869: }
870: }
871: }
872:
873: /*
874: * See if we can use the user's choice of editors either because
875: * we allow any $EDITOR or because $EDITOR is in the allowable list.
876: */
877: Editor = EditorArgs = EditorPath = NULL;
878: if (def_env_editor && UserEditor) {
879: Editor = UserEditor;
880: EditorArgs = UserEditorArgs;
881: } else if (UserEditor) {
882: struct stat editor_sb;
883: struct stat user_editor_sb;
884: char *base, *userbase;
885:
886: if (stat(UserEditor, &user_editor_sb) != 0) {
887: /* Should never happen since we already checked above. */
888: error(1, _("unable to stat editor (%s)"), UserEditor);
889: }
890: EditorPath = estrdup(def_editor);
891: Editor = strtok(EditorPath, ":");
892: do {
893: EditorArgs = get_args(Editor);
894: /*
895: * Both Editor and UserEditor should be fully qualified but
896: * check anyway...
897: */
898: if ((base = strrchr(Editor, '/')) == NULL)
899: continue;
900: if ((userbase = strrchr(UserEditor, '/')) == NULL) {
901: Editor = NULL;
902: break;
903: }
904: base++, userbase++;
905:
906: /*
907: * We compare the basenames first and then use stat to match
908: * for sure.
909: */
910: if (strcmp(base, userbase) == 0) {
911: if (stat(Editor, &editor_sb) == 0 && S_ISREG(editor_sb.st_mode)
912: && (editor_sb.st_mode & 0000111) &&
913: editor_sb.st_dev == user_editor_sb.st_dev &&
914: editor_sb.st_ino == user_editor_sb.st_ino)
915: break;
916: }
917: } while ((Editor = strtok(NULL, ":")));
918: }
919:
920: /*
921: * Can't use $EDITOR, try each element of def_editor until we
922: * find one that exists, is regular, and is executable.
923: */
924: if (Editor == NULL || *Editor == '\0') {
925: efree(EditorPath);
926: EditorPath = estrdup(def_editor);
927: Editor = strtok(EditorPath, ":");
928: do {
929: EditorArgs = get_args(Editor);
930: if (sudo_goodpath(Editor, NULL))
931: break;
932: } while ((Editor = strtok(NULL, ":")));
933:
934: /* Bleah, none of the editors existed! */
935: if (Editor == NULL || *Editor == '\0')
936: errorx(1, _("no editor found (editor path = %s)"), def_editor);
937: }
938: *args = EditorArgs;
939: return Editor;
940: }
941:
942: /*
943: * Split out any command line arguments and return them.
944: */
945: static char *
946: get_args(char *cmnd)
947: {
948: char *args;
949:
950: args = cmnd;
951: while (*args && !isblank((unsigned char) *args))
952: args++;
953: if (*args) {
954: *args++ = '\0';
955: while (*args && isblank((unsigned char) *args))
956: args++;
957: }
958: return *args ? args : NULL;
959: }
960:
961: /*
962: * Look up the hostname and set user_host and user_shost.
963: */
964: static void
965: get_hostname(void)
966: {
967: char *p, thost[MAXHOSTNAMELEN + 1];
968:
969: if (gethostname(thost, sizeof(thost)) != 0) {
970: user_host = user_shost = "localhost";
971: return;
972: }
973: thost[sizeof(thost) - 1] = '\0';
974: user_host = estrdup(thost);
975:
976: if ((p = strchr(user_host, '.'))) {
977: *p = '\0';
978: user_shost = estrdup(user_host);
979: *p = '.';
980: } else {
981: user_shost = user_host;
982: }
983: }
984:
985: static int
986: alias_remove_recursive(char *name, int type, int strict, int quiet)
987: {
988: struct member *m;
989: struct alias *a;
990: int error = 0;
991:
992: if ((a = alias_find(name, type)) != NULL) {
993: tq_foreach_fwd(&a->members, m) {
994: if (m->type == ALIAS) {
995: if (!alias_remove_recursive(m->name, type, strict, quiet))
996: error = 1;
997: }
998: }
999: }
1000: alias_seqno++;
1001: a = alias_remove(name, type);
1002: if (a)
1003: rbinsert(alias_freelist, a);
1004: return error;
1005: }
1006:
1007: static int
1008: check_alias(char *name, int type, int strict, int quiet)
1009: {
1010: struct member *m;
1011: struct alias *a;
1012: int error = 0;
1013:
1014: if ((a = alias_find(name, type)) != NULL) {
1015: /* check alias contents */
1016: tq_foreach_fwd(&a->members, m) {
1017: if (m->type == ALIAS)
1018: error += check_alias(m->name, type, strict, quiet);
1019: }
1020: } else {
1021: if (!quiet) {
1022: char *fmt;
1023: if (errno == ELOOP) {
1024: fmt = strict ?
1025: _("Error: cycle in %s_Alias `%s'") :
1026: _("Warning: cycle in %s_Alias `%s'");
1027: } else {
1028: fmt = strict ?
1029: _("Error: %s_Alias `%s' referenced but not defined") :
1030: _("Warning: %s_Alias `%s' referenced but not defined");
1031: }
1032: warningx(fmt,
1033: type == HOSTALIAS ? "Host" : type == CMNDALIAS ? "Cmnd" :
1034: type == USERALIAS ? "User" : type == RUNASALIAS ? "Runas" :
1035: "Unknown", name);
1036: }
1037: error++;
1038: }
1039:
1040: return error;
1041: }
1042:
1043: /*
1044: * Iterate through the sudoers datastructures looking for undefined
1045: * aliases or unused aliases.
1046: */
1047: static int
1048: check_aliases(int strict, int quiet)
1049: {
1050: struct cmndspec *cs;
1051: struct member *m, *binding;
1052: struct privilege *priv;
1053: struct userspec *us;
1054: struct defaults *d;
1055: int atype, error = 0;
1056:
1057: alias_freelist = rbcreate(alias_compare);
1058:
1059: /* Forward check. */
1060: tq_foreach_fwd(&userspecs, us) {
1061: tq_foreach_fwd(&us->users, m) {
1062: if (m->type == ALIAS) {
1063: alias_seqno++;
1064: error += check_alias(m->name, USERALIAS, strict, quiet);
1065: }
1066: }
1067: tq_foreach_fwd(&us->privileges, priv) {
1068: tq_foreach_fwd(&priv->hostlist, m) {
1069: if (m->type == ALIAS) {
1070: alias_seqno++;
1071: error += check_alias(m->name, HOSTALIAS, strict, quiet);
1072: }
1073: }
1074: tq_foreach_fwd(&priv->cmndlist, cs) {
1075: tq_foreach_fwd(&cs->runasuserlist, m) {
1076: if (m->type == ALIAS) {
1077: alias_seqno++;
1078: error += check_alias(m->name, RUNASALIAS, strict, quiet);
1079: }
1080: }
1081: if ((m = cs->cmnd)->type == ALIAS) {
1082: alias_seqno++;
1083: error += check_alias(m->name, CMNDALIAS, strict, quiet);
1084: }
1085: }
1086: }
1087: }
1088:
1089: /* Reverse check (destructive) */
1090: tq_foreach_fwd(&userspecs, us) {
1091: tq_foreach_fwd(&us->users, m) {
1092: if (m->type == ALIAS) {
1093: alias_seqno++;
1094: if (!alias_remove_recursive(m->name, USERALIAS, strict, quiet))
1095: error++;
1096: }
1097: }
1098: tq_foreach_fwd(&us->privileges, priv) {
1099: tq_foreach_fwd(&priv->hostlist, m) {
1100: if (m->type == ALIAS) {
1101: alias_seqno++;
1102: if (!alias_remove_recursive(m->name, HOSTALIAS, strict,
1103: quiet))
1104: error++;
1105: }
1106: }
1107: tq_foreach_fwd(&priv->cmndlist, cs) {
1108: tq_foreach_fwd(&cs->runasuserlist, m) {
1109: if (m->type == ALIAS) {
1110: alias_seqno++;
1111: if (!alias_remove_recursive(m->name, RUNASALIAS,
1112: strict, quiet))
1113: error++;
1114: }
1115: }
1116: if ((m = cs->cmnd)->type == ALIAS) {
1117: alias_seqno++;
1118: if (!alias_remove_recursive(m->name, CMNDALIAS, strict,
1119: quiet))
1120: error++;
1121: }
1122: }
1123: }
1124: }
1125: tq_foreach_fwd(&defaults, d) {
1126: switch (d->type) {
1127: case DEFAULTS_HOST:
1128: atype = HOSTALIAS;
1129: break;
1130: case DEFAULTS_USER:
1131: atype = USERALIAS;
1132: break;
1133: case DEFAULTS_RUNAS:
1134: atype = RUNASALIAS;
1135: break;
1136: case DEFAULTS_CMND:
1137: atype = CMNDALIAS;
1138: break;
1139: default:
1140: continue; /* not an alias */
1141: }
1142: tq_foreach_fwd(&d->binding, binding) {
1143: for (m = binding; m != NULL; m = m->next) {
1144: if (m->type == ALIAS) {
1145: alias_seqno++;
1146: if (!alias_remove_recursive(m->name, atype, strict, quiet))
1147: error++;
1148: }
1149: }
1150: }
1151: }
1152: rbdestroy(alias_freelist, alias_free);
1153:
1154: /* If all aliases were referenced we will have an empty tree. */
1155: if (!no_aliases() && !quiet)
1156: alias_apply(print_unused, strict ? "Error" : "Warning");
1157:
1158: return strict ? error : 0;
1159: }
1160:
1161: static int
1162: print_unused(void *v1, void *v2)
1163: {
1164: struct alias *a = (struct alias *)v1;
1165: char *prefix = (char *)v2;
1166:
1167: warningx(_("%s: unused %s_Alias %s"), prefix,
1168: a->type == HOSTALIAS ? "Host" : a->type == CMNDALIAS ? "Cmnd" :
1169: a->type == USERALIAS ? "User" : a->type == RUNASALIAS ? "Runas" :
1170: "Unknown", a->name);
1171: return 0;
1172: }
1173:
1174: /*
1175: * Unlink any sudoers temp files that remain.
1176: */
1177: void
1178: cleanup(int gotsignal)
1179: {
1180: struct sudoersfile *sp;
1181:
1182: tq_foreach_fwd(&sudoerslist, sp) {
1183: if (sp->tpath != NULL)
1184: (void) unlink(sp->tpath);
1185: }
1186: if (!gotsignal) {
1187: sudo_endpwent();
1188: sudo_endgrent();
1189: }
1190: }
1191:
1192: /*
1193: * Unlink sudoers temp files (if any) and exit.
1194: */
1195: static void
1196: quit(int signo)
1197: {
1198: const char *signame, *myname;
1199:
1200: cleanup(signo);
1201: #define emsg " exiting due to signal: "
1202: myname = getprogname();
1203: signame = strsignal(signo);
1204: if (write(STDERR_FILENO, myname, strlen(myname)) == -1 ||
1205: write(STDERR_FILENO, emsg, sizeof(emsg) - 1) == -1 ||
1206: write(STDERR_FILENO, signame, strlen(signame)) == -1 ||
1207: write(STDERR_FILENO, "\n", 1) == -1)
1208: /* shut up glibc */;
1209: _exit(signo);
1210: }
1211:
1212: static void
1213: usage(int fatal)
1214: {
1215: (void) fprintf(fatal ? stderr : stdout,
1216: "usage: %s [-chqsV] [-f sudoers]\n", getprogname());
1217: if (fatal)
1218: exit(1);
1219: }
1220:
1221: static void
1222: help(void)
1223: {
1224: (void) printf(_("%s - safely edit the sudoers file\n\n"), getprogname());
1225: usage(0);
1226: (void) puts(_("\nOptions:\n"
1227: " -c check-only mode\n"
1228: " -f sudoers specify sudoers file location\n"
1229: " -h display help message and exit\n"
1230: " -q less verbose (quiet) syntax error messages\n"
1231: " -s strict syntax checking\n"
1232: " -V display version information and exit"));
1233: exit(0);
1234: }
1235:
1236: static int
1237: visudo_printf(int msg_type, const char *fmt, ...)
1238: {
1239: va_list ap;
1240: FILE *fp;
1241:
1242: switch (msg_type) {
1243: case SUDO_CONV_INFO_MSG:
1244: fp = stdout;
1245: break;
1246: case SUDO_CONV_ERROR_MSG:
1247: fp = stderr;
1248: break;
1249: default:
1250: errno = EINVAL;
1251: return -1;
1252: }
1253:
1254: va_start(ap, fmt);
1255: vfprintf(fp, fmt, ap);
1256: va_end(ap);
1257:
1258: return 0;
1259: }
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