misc-utils/namei.c

   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 writtent by:
  17  *      Roger S. Southwick (May 2, 1990)
  18  *      Steve Tell (March 28, 1991)
  19  *      Arkadiusz Mikiewicz (1999-02-22)
  20  *      Li Zefan (2007-09-10).
  21  */
  22
  23 #include <stdio.h>
  24 #include <unistd.h>
  25 #include <getopt.h>
  26 #include <string.h>
  27 #include <strings.h>
  28 #include <stdlib.h>
  29 #include <errno.h>
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32 #include <sys/param.h>
  33 #include <pwd.h>
  34 #include <grp.h>
  35
  36 #include "c.h"
  37 #include "xalloc.h"
  38 #include "nls.h"
  39 #include "widechar.h"
  40 #include "strutils.h"
  41 #include "closestream.h"
  42
  43 #ifndef MAXSYMLINKS
  44 #define MAXSYMLINKS 256
  45 #endif
  46
  47 #ifndef LOGIN_NAME_MAX
  48 #define LOGIN_NAME_MAX 256
  49 #endif
  50
  51 #define NAMEI_NOLINKS   (1 << 1)
  52 #define NAMEI_MODES     (1 << 2)
  53 #define NAMEI_MNTS      (1 << 3)
  54 #define NAMEI_OWNERS    (1 << 4)
  55 #define NAMEI_VERTICAL  (1 << 5)
  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;          /* is this item not existing */
  67 };
  68
  69 struct idcache {
  70         unsigned long int       id;
  71         char                    *name;
  72         struct idcache          *next;
  73 };
  74
  75 static int flags;
  76 static int uwidth;              /* maximal width of username */
  77 static int gwidth;              /* maximal width of groupname */
  78 static struct idcache *gcache;  /* groupnames */
  79 static struct idcache *ucache;  /* usernames */
  80
  81 static struct idcache *
  82 get_id(struct idcache *ic, unsigned long int id)
  83 {
  84         while(ic) {
  85                 if (ic->id == id)
  86                         return ic;
  87                 ic = ic->next;
  88         }
  89         return NULL;
  90 }
  91
  92 static void
  93 free_idcache(struct idcache *ic)
  94 {
  95         while(ic) {
  96                 struct idcache *next = ic->next;
  97                 free(ic->name);
  98                 free(ic);
  99                 ic = next;
 100         }
 101 }
 102
 103 static void
 104 add_id(struct idcache **ic, char *name, unsigned long int id, int *width)
 105 {
 106         struct idcache *nc, *x;
 107         int w = 0;
 108
 109         nc = xcalloc(1, sizeof(*nc));
 110         nc->id = id;
 111
 112         if (name) {
 113 #ifdef HAVE_WIDECHAR
 114                 wchar_t wc[LOGIN_NAME_MAX + 1];
 115
 116                 if (mbstowcs(wc, name, LOGIN_NAME_MAX) > 0) {
 117                         wc[LOGIN_NAME_MAX] = '\0';
 118                         w = wcswidth(wc, LOGIN_NAME_MAX);
 119                 }
 120                 else
 121 #endif
 122                         w = strlen(name);
 123         }
 124         /* note, we ignore names with non-printable widechars */
 125         if (w > 0)
 126                 nc->name = xstrdup(name);
 127         else if (xasprintf(&nc->name, "%lu", id) == -1)
 128                 nc->name = NULL;
 129
 130         for (x = *ic; x && x->next; x = x->next);
 131
 132         /* add 'nc' at end of the 'ic' list */
 133         if (x)
 134                 x->next = nc;
 135         else
 136                 *ic = nc;
 137         if (w <= 0)
 138                 w = nc->name ? strlen(nc->name) : 0;
 139
 140         *width = *width < w ? w : *width;
 141         return;
 142 }
 143
 144 static void
 145 add_uid(unsigned long int id)
 146 {
 147         struct idcache *ic = get_id(ucache, id);
 148
 149         if (!ic) {
 150                 struct passwd *pw = getpwuid((uid_t) id);
 151                 add_id(&ucache, pw ? pw->pw_name : NULL, id, &uwidth);
 152         }
 153 }
 154
 155 static void
 156 add_gid(unsigned long int id)
 157 {
 158         struct idcache *ic = get_id(gcache, id);
 159
 160         if (!ic) {
 161                 struct group *gr = getgrgid((gid_t) id);
 162                 add_id(&gcache, gr ? gr->gr_name : NULL, id, &gwidth);
 163         }
 164 }
 165
 166 static void
 167 free_namei(struct namei *nm)
 168 {
 169         while (nm) {
 170                 struct namei *next = nm->next;
 171                 free(nm->name);
 172                 free(nm->abslink);
 173                 free(nm);
 174                 nm = next;
 175         }
 176 }
 177
 178 static void
 179 readlink_to_namei(struct namei *nm, const char *path)
 180 {
 181         char sym[PATH_MAX];
 182         ssize_t sz;
 183         int isrel = 0;
 184
 185         sz = readlink(path, sym, sizeof(sym));
 186         if (sz < 1)
 187                 err(EXIT_FAILURE, _("failed to read symlink: %s"), path);
 188         if (*sym != '/') {
 189                 char *p = strrchr(path, '/');
 190
 191                 if (p) {
 192                         isrel = 1;
 193                         nm->relstart = p ? p - path : 0;
 194                         sz += nm->relstart + 1;
 195                 }
 196         }
 197         nm->abslink = xmalloc(sz + 1);
 198
 199         if (*sym != '/' && isrel) {
 200                 /* create the absolute path from the relative symlink */
 201                 memcpy(nm->abslink, path, nm->relstart);
 202                 *(nm->abslink + nm->relstart) = '/';
 203                 nm->relstart++;
 204                 memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart);
 205         } else
 206                 /* - absolute link (foo -> /path/bar)
 207                  * - or link without any subdir (foo -> bar)
 208                  */
 209                 memcpy(nm->abslink, sym, sz);
 210
 211         nm->abslink[sz] = '\0';
 212 }
 213
 214 static struct stat *
 215 dotdot_stat(const char *dirname, struct stat *st)
 216 {
 217         char *path;
 218         size_t len;
 219
 220 #define DOTDOTDIR       "/.."
 221
 222         if (!dirname)
 223                 return NULL;
 224
 225         len = strlen(dirname);
 226         path = xmalloc(len + sizeof(DOTDOTDIR));
 227
 228         memcpy(path, dirname, len);
 229         memcpy(path + len, DOTDOTDIR, sizeof(DOTDOTDIR));
 230
 231         if (stat(path, st))
 232                 err(EXIT_FAILURE, _("could not stat '%s'"), path);
 233         free(path);
 234         return st;
 235 }
 236
 237 static struct namei *
 238 new_namei(struct namei *parent, const char *path, const char *fname, int lev)
 239 {
 240         struct namei *nm;
 241
 242         if (!fname)
 243                 return NULL;
 244         nm = xcalloc(1, sizeof(*nm));
 245         if (parent)
 246                 parent->next = nm;
 247
 248         nm->level = lev;
 249         nm->name = xstrdup(fname);
 250
 251         nm->noent = (lstat(path, &nm->st) == -1);
 252         if (nm->noent)
 253                 return nm;
 254
 255         if (S_ISLNK(nm->st.st_mode))
 256                 readlink_to_namei(nm, path);
 257         if (flags & NAMEI_OWNERS) {
 258                 add_uid(nm->st.st_uid);
 259                 add_gid(nm->st.st_gid);
 260         }
 261
 262         if ((flags & NAMEI_MNTS) && S_ISDIR(nm->st.st_mode)) {
 263                 struct stat stbuf, *sb = NULL;
 264
 265                 if (parent && S_ISDIR(parent->st.st_mode))
 266                         sb = &parent->st;
 267                 else if (!parent || S_ISLNK(parent->st.st_mode))
 268                         sb = dotdot_stat(path, &stbuf);
 269
 270                 if (sb && (sb->st_dev != nm->st.st_dev ||   /* different device */
 271                            sb->st_ino == nm->st.st_ino))    /* root directory */
 272                         nm->mountpoint = 1;
 273         }
 274
 275         return nm;
 276 }
 277
 278 static struct namei *
 279 add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last)
 280 {
 281         struct namei *nm = NULL, *first = NULL;
 282         char *fname, *end, *path;
 283         int level = 0;
 284
 285         if (!orgpath)
 286                 return NULL;
 287         if (parent) {
 288                 nm = parent;
 289                 level = parent->level + 1;
 290         }
 291         path = xstrdup(orgpath);
 292         fname = path + start;
 293
 294         /* root directory */
 295         if (*fname == '/') {
 296                 while (*fname == '/')
 297                         fname++; /* eat extra '/' */
 298                 first = nm = new_namei(nm, "/", "/", level);
 299         }
 300
 301         for (end = fname; fname && end; ) {
 302                 /* set end of filename */
 303                 if (*fname) {
 304                         end = strchr(fname, '/');
 305                         if (end)
 306                                 *end = '\0';
 307
 308                         /* create a new entry */
 309                         nm = new_namei(nm, path, fname, level);
 310                 } else
 311                         end = NULL;
 312                 if (!first)
 313                         first = nm;
 314                 /* set begin of the next filename */
 315                 if (end) {
 316                         *end++ = '/';
 317                         while (*end == '/')
 318                                 end++; /* eat extra '/' */
 319                 }
 320                 fname = end;
 321         }
 322
 323         if (last)
 324                 *last = nm;
 325
 326         free(path);
 327
 328         return first;
 329 }
 330
 331 static int
 332 follow_symlinks(struct namei *nm)
 333 {
 334         int symcount = 0;
 335
 336         for (; nm; nm = nm->next) {
 337                 struct namei *next, *last;
 338
 339                 if (nm->noent)
 340                         continue;
 341                 if (!S_ISLNK(nm->st.st_mode))
 342                         continue;
 343                 if (++symcount > MAXSYMLINKS) {
 344                         /* drop the rest of the list */
 345                         free_namei(nm->next);
 346                         nm->next = NULL;
 347                         return -1;
 348                 }
 349                 next = nm->next;
 350                 nm->next = add_namei(nm, nm->abslink, nm->relstart, &last);
 351                 if (last)
 352                         last->next = next;
 353                 else
 354                         nm->next = next;
 355         }
 356         return 0;
 357 }
 358
 359 static int
 360 print_namei(struct namei *nm, char *path)
 361 {
 362         int i;
 363
 364         if (path)
 365                 printf("f: %s\n", path);
 366
 367         for (; nm; nm = nm->next) {
 368                 char md[11];
 369
 370                 if (nm->noent) {
 371                         printf(_("%s - No such file or directory\n"), nm->name);
 372                         return -1;
 373                 }
 374
 375                 strmode(nm->st.st_mode, md);
 376
 377                 if (nm->mountpoint)
 378                         md[0] = 'D';
 379
 380                 if (!(flags & NAMEI_VERTICAL)) {
 381                         for (i = 0; i < nm->level; i++)
 382                                 fputs("  ", stdout);
 383                         fputc(' ', stdout);
 384                 }
 385
 386                 if (flags & NAMEI_MODES)
 387                         printf("%s", md);
 388                 else
 389                         printf("%c", md[0]);
 390
 391                 if (flags & NAMEI_OWNERS) {
 392                         printf(" %-*s", uwidth,
 393                                 get_id(ucache, nm->st.st_uid)->name);
 394                         printf(" %-*s", gwidth,
 395                                 get_id(gcache, nm->st.st_gid)->name);
 396                 }
 397
 398                 if (flags & NAMEI_VERTICAL)
 399                         for (i = 0; i < nm->level; i++)
 400                                 fputs("  ", stdout);
 401
 402                 if (S_ISLNK(nm->st.st_mode))
 403                         printf(" %s -> %s\n", nm->name,
 404                                         nm->abslink + nm->relstart);
 405                 else
 406                         printf(" %s\n", nm->name);
 407         }
 408         return 0;
 409 }
 410
 411 static void usage(int rc)
 412 {
 413         const char *p = program_invocation_short_name;
 414         FILE *out = rc == EXIT_FAILURE ? stderr : stdout;
 415
 416         if (!*p)
 417                 p = "namei";
 418
 419         fputs(_("\nUsage:\n"), out);
 420         fprintf(out,
 421               _(" %s [options] pathname [pathname ...]\n"), p);
 422
 423         fputs(_("\nOptions:\n"), out);
 424         fputs(_(" -h, --help          displays this help text\n"
 425                 " -V, --version       output version information and exit\n"
 426                 " -x, --mountpoints   show mount point directories with a 'D'\n"
 427                 " -m, --modes         show the mode bits of each file\n"
 428                 " -o, --owners        show owner and group name of each file\n"
 429                 " -l, --long          use a long listing format (-m -o -v) \n"
 430                 " -n, --nosymlinks    don't follow symlinks\n"
 431                 " -v, --vertical      vertical align of modes and owners\n"), out);
 432
 433         fputs(_("\nFor more information see namei(1).\n"), out);
 434         exit(rc);
 435 }
 436
 437 static const struct option longopts[] =
 438 {
 439         { "help",       0, 0, 'h' },
 440         { "version",    0, 0, 'V' },
 441         { "mountpoints",0, 0, 'x' },
 442         { "modes",      0, 0, 'm' },
 443         { "owners",     0, 0, 'o' },
 444         { "long",       0, 0, 'l' },
 445         { "nolinks",    0, 0, 'n' },
 446         { "vertical",   0, 0, 'v' },
 447         { NULL,         0, 0, 0 },
 448 };
 449
 450 int
 451 main(int argc, char **argv)
 452 {
 453         int c;
 454         int rc = EXIT_SUCCESS;
 455
 456         setlocale(LC_ALL, "");
 457         bindtextdomain(PACKAGE, LOCALEDIR);
 458         textdomain(PACKAGE);
 459         atexit(close_stdout);
 460
 461         while ((c = getopt_long(argc, argv, "hVlmnovx", longopts, NULL)) != -1) {
 462                 switch(c) {
 463                 case 'h':
 464                         usage(EXIT_SUCCESS);
 465                         break;
 466                 case 'V':
 467                         printf(_("%s from %s\n"), program_invocation_short_name,
 468                                                   PACKAGE_STRING);
 469                         return EXIT_SUCCESS;
 470                 case 'l':
 471                         flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL);
 472                         break;
 473                 case 'm':
 474                         flags |= NAMEI_MODES;
 475                         break;
 476                 case 'n':
 477                         flags |= NAMEI_NOLINKS;
 478                         break;
 479                 case 'o':
 480                         flags |= NAMEI_OWNERS;
 481                         break;
 482                 case 'x':
 483                         flags |= NAMEI_MNTS;
 484                         break;
 485                 case 'v':
 486                         flags |= NAMEI_VERTICAL;
 487                         break;
 488                 default:
 489                         usage(EXIT_FAILURE);
 490                 }
 491         }
 492
 493         if (optind == argc) {
 494                 warnx(_("pathname argument is missing"));
 495                 usage(EXIT_FAILURE);
 496         }
 497
 498         for(; optind < argc; optind++) {
 499                 char *path = argv[optind];
 500                 struct namei *nm = NULL;
 501                 struct stat st;
 502
 503                 if (stat(path, &st) != 0)
 504                         rc = EXIT_FAILURE;
 505
 506                 nm = add_namei(NULL, path, 0, NULL);
 507                 if (nm) {
 508                         int sml = 0;
 509                         if (!(flags & NAMEI_NOLINKS))
 510                                 sml = follow_symlinks(nm);
 511                         if (print_namei(nm, path)) {
 512                                 rc = EXIT_FAILURE;
 513                                 continue;
 514                         }
 515                         free_namei(nm);
 516                         if (sml == -1) {
 517                                 rc = EXIT_FAILURE;
 518                                 warnx(_("%s: exceeded limit of symlinks"), path);
 519                                 continue;
 520                         }
 521                 }
 522         }
 523
 524         free_idcache(ucache);
 525         free_idcache(gcache);
 526
 527         return rc;
 528 }
 529