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1 | /* | |
2 | * Copyright (C) 2008 Karel Zak <kzak@redhat.com> | |
3 | * | |
4 | * This file is part of util-linux. | |
5 | * | |
6 | * This file is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This file is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * The original namei(1) was written by: | |
17 | * Roger S. Southwick (May 2, 1990) | |
18 | * Steve Tell (March 28, 1991) | |
19 | * Arkadiusz MiĆkiewicz (1999-02-22) | |
20 | * Li Zefan (2007-09-10). | |
21 | */ | |
22 | #include <stdio.h> | |
23 | #include <unistd.h> | |
24 | #include <getopt.h> | |
25 | #include <string.h> | |
26 | #include <stdlib.h> | |
27 | #include <errno.h> | |
28 | #include <sys/types.h> | |
29 | #include <sys/stat.h> | |
30 | #include <sys/param.h> | |
31 | #include <pwd.h> | |
32 | #include <grp.h> | |
33 | ||
34 | #ifdef HAVE_LIBSELINUX | |
35 | # include <selinux/selinux.h> | |
36 | #endif | |
37 | ||
38 | #include "c.h" | |
39 | #include "xalloc.h" | |
40 | #include "nls.h" | |
41 | #include "widechar.h" | |
42 | #include "strutils.h" | |
43 | #include "closestream.h" | |
44 | #include "idcache.h" | |
45 | ||
46 | #ifndef MAXSYMLINKS | |
47 | #define MAXSYMLINKS 256 | |
48 | #endif | |
49 | ||
50 | #define NAMEI_NOLINKS (1 << 1) | |
51 | #define NAMEI_MODES (1 << 2) | |
52 | #define NAMEI_MNTS (1 << 3) | |
53 | #define NAMEI_OWNERS (1 << 4) | |
54 | #define NAMEI_VERTICAL (1 << 5) | |
55 | #define NAMEI_CONTEXT (1 << 6) | |
56 | ||
57 | ||
58 | struct namei { | |
59 | struct stat st; /* item lstat() */ | |
60 | char *name; /* item name */ | |
61 | char *abslink; /* absolute symlink path */ | |
62 | int relstart; /* offset of relative path in 'abslink' */ | |
63 | struct namei *next; /* next item */ | |
64 | int level; | |
65 | int mountpoint; /* is mount point */ | |
66 | int noent; /* this item not existing (stores errno from stat()) */ | |
67 | #ifdef HAVE_LIBSELINUX | |
68 | int context_len; /* length of selinux contexts, as returned by lgetfilecon(3) */ | |
69 | char *context; /* selinux contexts, as set by lgetfilecon(3) */ | |
70 | #endif | |
71 | }; | |
72 | ||
73 | static int flags; | |
74 | static struct idcache *gcache; /* groupnames */ | |
75 | static struct idcache *ucache; /* usernames */ | |
76 | ||
77 | static void | |
78 | free_namei(struct namei *nm) | |
79 | { | |
80 | while (nm) { | |
81 | struct namei *next = nm->next; | |
82 | #ifdef HAVE_LIBSELINUX | |
83 | free(nm->context); | |
84 | #endif | |
85 | free(nm->name); | |
86 | free(nm->abslink); | |
87 | free(nm); | |
88 | nm = next; | |
89 | } | |
90 | } | |
91 | ||
92 | static void | |
93 | readlink_to_namei(struct namei *nm, const char *path) | |
94 | { | |
95 | char sym[PATH_MAX]; | |
96 | ssize_t sz; | |
97 | int isrel = 0; | |
98 | ||
99 | sz = readlink(path, sym, sizeof(sym)); | |
100 | if (sz < 1) | |
101 | err(EXIT_FAILURE, _("failed to read symlink: %s"), path); | |
102 | if (*sym != '/') { | |
103 | char *p = strrchr(path, '/'); | |
104 | ||
105 | if (p) { | |
106 | isrel = 1; | |
107 | nm->relstart = p - path; | |
108 | sz += nm->relstart + 1; | |
109 | } | |
110 | } | |
111 | nm->abslink = xmalloc(sz + 1); | |
112 | ||
113 | if (isrel) { | |
114 | /* create the absolute path from the relative symlink */ | |
115 | memcpy(nm->abslink, path, nm->relstart); | |
116 | *(nm->abslink + nm->relstart) = '/'; | |
117 | nm->relstart++; | |
118 | memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart); | |
119 | } else | |
120 | /* - absolute link (foo -> /path/bar) | |
121 | * - or link without any subdir (foo -> bar) | |
122 | */ | |
123 | memcpy(nm->abslink, sym, sz); | |
124 | ||
125 | nm->abslink[sz] = '\0'; | |
126 | } | |
127 | ||
128 | static struct stat * | |
129 | dotdot_stat(const char *dirname, struct stat *st) | |
130 | { | |
131 | char *path; | |
132 | size_t len; | |
133 | ||
134 | #define DOTDOTDIR "/.." | |
135 | ||
136 | if (!dirname) | |
137 | return NULL; | |
138 | ||
139 | len = strlen(dirname); | |
140 | path = xmalloc(len + sizeof(DOTDOTDIR)); | |
141 | ||
142 | memcpy(path, dirname, len); | |
143 | memcpy(path + len, DOTDOTDIR, sizeof(DOTDOTDIR)); | |
144 | ||
145 | if (stat(path, st)) | |
146 | err(EXIT_FAILURE, _("stat of %s failed"), path); | |
147 | free(path); | |
148 | return st; | |
149 | } | |
150 | ||
151 | static struct namei * | |
152 | new_namei(struct namei *parent, const char *path, const char *fname, int lev) | |
153 | { | |
154 | struct namei *nm; | |
155 | ||
156 | if (!fname) | |
157 | return NULL; | |
158 | nm = xcalloc(1, sizeof(*nm)); | |
159 | if (parent) | |
160 | parent->next = nm; | |
161 | ||
162 | nm->level = lev; | |
163 | nm->name = xstrdup(fname); | |
164 | ||
165 | #ifdef HAVE_LIBSELINUX | |
166 | /* Don't use is_selinux_enabled() here. We need info about a context | |
167 | * also on systems where SELinux is (temporary) disabled */ | |
168 | nm->context_len = lgetfilecon(path, &nm->context); | |
169 | #endif | |
170 | if (lstat(path, &nm->st) != 0) { | |
171 | nm->noent = errno; | |
172 | return nm; | |
173 | } | |
174 | ||
175 | if (S_ISLNK(nm->st.st_mode)) | |
176 | readlink_to_namei(nm, path); | |
177 | if (flags & NAMEI_OWNERS) { | |
178 | add_uid(ucache, nm->st.st_uid); | |
179 | add_gid(gcache, nm->st.st_gid); | |
180 | } | |
181 | ||
182 | if ((flags & NAMEI_MNTS) && S_ISDIR(nm->st.st_mode)) { | |
183 | struct stat stbuf, *sb = NULL; | |
184 | ||
185 | if (parent && S_ISDIR(parent->st.st_mode)) | |
186 | sb = &parent->st; | |
187 | else if (!parent || S_ISLNK(parent->st.st_mode)) | |
188 | sb = dotdot_stat(path, &stbuf); | |
189 | ||
190 | if (sb && (sb->st_dev != nm->st.st_dev || /* different device */ | |
191 | sb->st_ino == nm->st.st_ino)) /* root directory */ | |
192 | nm->mountpoint = 1; | |
193 | } | |
194 | ||
195 | return nm; | |
196 | } | |
197 | ||
198 | static struct namei * | |
199 | add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last) | |
200 | { | |
201 | struct namei *nm = NULL, *first = NULL; | |
202 | char *fname, *end, *path; | |
203 | int level = 0; | |
204 | ||
205 | if (!orgpath) | |
206 | return NULL; | |
207 | if (parent) { | |
208 | nm = parent; | |
209 | level = parent->level + 1; | |
210 | } | |
211 | path = xstrdup(orgpath); | |
212 | fname = path + start; | |
213 | ||
214 | /* root directory */ | |
215 | if (*fname == '/') { | |
216 | while (*fname == '/') | |
217 | fname++; /* eat extra '/' */ | |
218 | first = nm = new_namei(nm, "/", "/", level); | |
219 | } | |
220 | ||
221 | for (end = fname; fname && end; ) { | |
222 | /* set end of filename */ | |
223 | if (*fname) { | |
224 | end = strchr(fname, '/'); | |
225 | if (end) | |
226 | *end = '\0'; | |
227 | ||
228 | /* create a new entry */ | |
229 | nm = new_namei(nm, path, fname, level); | |
230 | } else | |
231 | end = NULL; | |
232 | if (!first) | |
233 | first = nm; | |
234 | /* set begin of the next filename */ | |
235 | if (end) { | |
236 | *end++ = '/'; | |
237 | while (*end == '/') | |
238 | end++; /* eat extra '/' */ | |
239 | } | |
240 | fname = end; | |
241 | } | |
242 | ||
243 | if (last) | |
244 | *last = nm; | |
245 | ||
246 | free(path); | |
247 | ||
248 | return first; | |
249 | } | |
250 | ||
251 | static int | |
252 | follow_symlinks(struct namei *nm) | |
253 | { | |
254 | int symcount = 0; | |
255 | ||
256 | for (; nm; nm = nm->next) { | |
257 | struct namei *next, *last; | |
258 | ||
259 | if (nm->noent) | |
260 | continue; | |
261 | if (!S_ISLNK(nm->st.st_mode)) | |
262 | continue; | |
263 | if (++symcount > MAXSYMLINKS) { | |
264 | /* drop the rest of the list */ | |
265 | free_namei(nm->next); | |
266 | nm->next = NULL; | |
267 | return -1; | |
268 | } | |
269 | next = nm->next; | |
270 | nm->next = add_namei(nm, nm->abslink, nm->relstart, &last); | |
271 | if (last) | |
272 | last->next = next; | |
273 | else | |
274 | nm->next = next; | |
275 | } | |
276 | return 0; | |
277 | } | |
278 | ||
279 | static int | |
280 | print_namei(struct namei *nm, char *path) | |
281 | { | |
282 | int i; | |
283 | ||
284 | if (path) | |
285 | printf("f: %s\n", path); | |
286 | ||
287 | for (; nm; nm = nm->next) { | |
288 | char md[11]; | |
289 | ||
290 | if (nm->noent) { | |
291 | int blanks = 1; | |
292 | if (flags & NAMEI_MODES) | |
293 | blanks += 9; | |
294 | if (flags & NAMEI_OWNERS) | |
295 | blanks += ucache->width + gcache->width + 2; | |
296 | if (!(flags & NAMEI_VERTICAL)) | |
297 | blanks += 1; | |
298 | if (!(flags & NAMEI_CONTEXT)) | |
299 | blanks += 1; | |
300 | blanks += nm->level * 2; | |
301 | printf("%*s ", blanks, ""); | |
302 | printf("%s - %s\n", nm->name, strerror(nm->noent)); | |
303 | return -1; | |
304 | } | |
305 | ||
306 | xstrmode(nm->st.st_mode, md); | |
307 | ||
308 | if (nm->mountpoint) | |
309 | md[0] = 'D'; | |
310 | ||
311 | if (!(flags & NAMEI_VERTICAL)) { | |
312 | for (i = 0; i < nm->level; i++) | |
313 | fputs(" ", stdout); | |
314 | fputc(' ', stdout); | |
315 | } | |
316 | ||
317 | if (flags & NAMEI_MODES) | |
318 | printf("%s", md); | |
319 | else | |
320 | printf("%c", md[0]); | |
321 | ||
322 | if (flags & NAMEI_OWNERS) { | |
323 | printf(" %-*s", ucache->width, | |
324 | get_id(ucache, nm->st.st_uid)->name); | |
325 | printf(" %-*s", gcache->width, | |
326 | get_id(gcache, nm->st.st_gid)->name); | |
327 | } | |
328 | #ifdef HAVE_LIBSELINUX | |
329 | if (flags & NAMEI_CONTEXT) { | |
330 | if (nm->context) | |
331 | printf(" %-*s", nm->context_len, nm->context); | |
332 | else | |
333 | printf(" ?"); | |
334 | } | |
335 | #endif | |
336 | if (flags & NAMEI_VERTICAL) | |
337 | for (i = 0; i < nm->level; i++) | |
338 | fputs(" ", stdout); | |
339 | ||
340 | if (S_ISLNK(nm->st.st_mode)) | |
341 | printf(" %s -> %s\n", nm->name, | |
342 | nm->abslink + nm->relstart); | |
343 | else | |
344 | printf(" %s\n", nm->name); | |
345 | } | |
346 | return 0; | |
347 | } | |
348 | ||
349 | static void __attribute__((__noreturn__)) usage(void) | |
350 | { | |
351 | const char *p = program_invocation_short_name; | |
352 | FILE *out = stdout; | |
353 | ||
354 | if (!*p) | |
355 | p = "namei"; | |
356 | ||
357 | fputs(USAGE_HEADER, out); | |
358 | fprintf(out, | |
359 | _(" %s [options] <pathname>...\n"), p); | |
360 | ||
361 | fputs(USAGE_SEPARATOR, out); | |
362 | fputs(_("Follow a pathname until a terminal point is found.\n"), out); | |
363 | ||
364 | fputs(USAGE_OPTIONS, out); | |
365 | fputs(_( | |
366 | " -x, --mountpoints show mount point directories with a 'D'\n" | |
367 | " -m, --modes show the mode bits of each file\n" | |
368 | " -o, --owners show owner and group name of each file\n" | |
369 | " -l, --long use a long listing format (-m -o -v) \n" | |
370 | " -n, --nosymlinks don't follow symlinks\n" | |
371 | " -v, --vertical vertical align of modes and owners\n"), out); | |
372 | #ifdef HAVE_LIBSELINUX | |
373 | fputs(_( " -Z, --context print any security context of each file \n"), out); | |
374 | #endif | |
375 | ||
376 | fprintf(out, USAGE_HELP_OPTIONS(21)); | |
377 | ||
378 | fprintf(out, USAGE_MAN_TAIL("namei(1)")); | |
379 | exit(EXIT_SUCCESS); | |
380 | } | |
381 | ||
382 | static const struct option longopts[] = | |
383 | { | |
384 | { "help", no_argument, NULL, 'h' }, | |
385 | { "version", no_argument, NULL, 'V' }, | |
386 | { "mountpoints", no_argument, NULL, 'x' }, | |
387 | { "modes", no_argument, NULL, 'm' }, | |
388 | { "owners", no_argument, NULL, 'o' }, | |
389 | { "long", no_argument, NULL, 'l' }, | |
390 | { "nolinks", no_argument, NULL, 'n' }, | |
391 | { "vertical", no_argument, NULL, 'v' }, | |
392 | #ifdef HAVE_LIBSELINUX | |
393 | { "context", no_argument, NULL, 'Z' }, | |
394 | #endif | |
395 | { NULL, 0, NULL, 0 }, | |
396 | }; | |
397 | ||
398 | int | |
399 | main(int argc, char **argv) | |
400 | { | |
401 | int c; | |
402 | int rc = EXIT_SUCCESS; | |
403 | static const char *shortopts = | |
404 | #ifdef HAVE_LIBSELINUX | |
405 | "Z" | |
406 | #endif | |
407 | "hVlmnovx"; | |
408 | ||
409 | setlocale(LC_ALL, ""); | |
410 | bindtextdomain(PACKAGE, LOCALEDIR); | |
411 | textdomain(PACKAGE); | |
412 | close_stdout_atexit(); | |
413 | ||
414 | while ((c = getopt_long(argc, argv, shortopts, longopts, NULL)) != -1) { | |
415 | switch(c) { | |
416 | case 'l': | |
417 | flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL); | |
418 | break; | |
419 | case 'm': | |
420 | flags |= NAMEI_MODES; | |
421 | break; | |
422 | case 'n': | |
423 | flags |= NAMEI_NOLINKS; | |
424 | break; | |
425 | case 'o': | |
426 | flags |= NAMEI_OWNERS; | |
427 | break; | |
428 | case 'x': | |
429 | flags |= NAMEI_MNTS; | |
430 | break; | |
431 | case 'v': | |
432 | flags |= NAMEI_VERTICAL; | |
433 | break; | |
434 | #ifdef HAVE_LIBSELINUX | |
435 | case 'Z': | |
436 | flags |= NAMEI_CONTEXT; | |
437 | break; | |
438 | #endif | |
439 | case 'h': | |
440 | usage(); | |
441 | case 'V': | |
442 | print_version(EXIT_SUCCESS); | |
443 | default: | |
444 | errtryhelp(EXIT_FAILURE); | |
445 | } | |
446 | } | |
447 | ||
448 | if (optind == argc) { | |
449 | warnx(_("pathname argument is missing")); | |
450 | errtryhelp(EXIT_FAILURE); | |
451 | } | |
452 | ||
453 | ucache = new_idcache(); | |
454 | if (!ucache) | |
455 | err(EXIT_FAILURE, _("failed to allocate UID cache")); | |
456 | gcache = new_idcache(); | |
457 | if (!gcache) | |
458 | err(EXIT_FAILURE, _("failed to allocate GID cache")); | |
459 | ||
460 | for(; optind < argc; optind++) { | |
461 | char *path = argv[optind]; | |
462 | struct namei *nm = NULL; | |
463 | struct stat st; | |
464 | ||
465 | if (stat(path, &st) != 0) | |
466 | rc = EXIT_FAILURE; | |
467 | ||
468 | nm = add_namei(NULL, path, 0, NULL); | |
469 | if (nm) { | |
470 | int sml = 0; | |
471 | if (!(flags & NAMEI_NOLINKS)) | |
472 | sml = follow_symlinks(nm); | |
473 | if (print_namei(nm, path)) { | |
474 | rc = EXIT_FAILURE; | |
475 | continue; | |
476 | } | |
477 | free_namei(nm); | |
478 | if (sml == -1) { | |
479 | rc = EXIT_FAILURE; | |
480 | warnx(_("%s: exceeded limit of symlinks"), path); | |
481 | continue; | |
482 | } | |
483 | } | |
484 | } | |
485 | ||
486 | free_idcache(ucache); | |
487 | free_idcache(gcache); | |
488 | ||
489 | return rc; | |
490 | } |