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 <stdlib.h>
  28 #include <errno.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <sys/param.h>
  32 #include <pwd.h>
  33 #include <grp.h>
  34
  35 #include "c.h"
  36 #include "xalloc.h"
  37 #include "nls.h"
  38 #include "widechar.h"
  39 #include "strutils.h"
  40 #include "closestream.h"
  41
  42 #ifndef MAXSYMLINKS
  43 #define MAXSYMLINKS 256
  44 #endif
  45
  46 #ifndef LOGIN_NAME_MAX
  47 #define LOGIN_NAME_MAX 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
  56
  57 struct namei {
  58         struct stat     st;             /* item lstat() */
  59         char            *name;          /* item name */
  60         char            *abslink;       /* absolute symlink path */
  61         int             relstart;       /* offset of relative path in 'abslink' */
  62         struct namei    *next;          /* next item */
  63         int             level;
  64         int             mountpoint;     /* is mount point */
  65         int             noent;          /* is this item not existing */
  66 };
  67
  68 struct idcache {
  69         unsigned long int       id;
  70         char                    *name;
  71         struct idcache          *next;
  72 };
  73
  74 static int flags;
  75 static int uwidth;              /* maximal width of username */
  76 static int gwidth;              /* maximal width of groupname */
  77 static struct idcache *gcache;  /* groupnames */
  78 static struct idcache *ucache;  /* usernames */
  79
  80 static struct idcache *
  81 get_id(struct idcache *ic, unsigned long int id)
  82 {
  83         while(ic) {
  84                 if (ic->id == id)
  85                         return ic;
  86                 ic = ic->next;
  87         }
  88         return NULL;
  89 }
  90
  91 static void
  92 free_idcache(struct idcache *ic)
  93 {
  94         while(ic) {
  95                 struct idcache *next = ic->next;
  96                 free(ic->name);
  97                 free(ic);
  98                 ic = next;
  99         }
 100 }
 101
 102 static void
 103 add_id(struct idcache **ic, char *name, unsigned long int id, int *width)
 104 {
 105         struct idcache *nc, *x;
 106         int w = 0;
 107
 108         nc = xcalloc(1, sizeof(*nc));
 109         nc->id = id;
 110
 111         if (name) {
 112 #ifdef HAVE_WIDECHAR
 113                 wchar_t wc[LOGIN_NAME_MAX + 1];
 114
 115                 if (mbstowcs(wc, name, LOGIN_NAME_MAX) > 0) {
 116                         wc[LOGIN_NAME_MAX] = '\0';
 117                         w = wcswidth(wc, LOGIN_NAME_MAX);
 118                 }
 119                 else
 120 #endif
 121                         w = strlen(name);
 122         }
 123         /* note, we ignore names with non-printable widechars */
 124         if (w > 0)
 125                 nc->name = xstrdup(name);
 126         else
 127                 xasprintf(&nc->name, "%lu", id);
 128
 129         for (x = *ic; x && x->next; x = x->next);
 130
 131         /* add 'nc' at end of the 'ic' list */
 132         if (x)
 133                 x->next = nc;
 134         else
 135                 *ic = nc;
 136         if (w <= 0)
 137                 w = nc->name ? strlen(nc->name) : 0;
 138
 139         *width = *width < w ? w : *width;
 140         return;
 141 }
 142
 143 static void
 144 add_uid(unsigned long int id)
 145 {
 146         struct idcache *ic = get_id(ucache, id);
 147
 148         if (!ic) {
 149                 struct passwd *pw = getpwuid((uid_t) id);
 150                 add_id(&ucache, pw ? pw->pw_name : NULL, id, &uwidth);
 151         }
 152 }
 153
 154 static void
 155 add_gid(unsigned long int id)
 156 {
 157         struct idcache *ic = get_id(gcache, id);
 158
 159         if (!ic) {
 160                 struct group *gr = getgrgid((gid_t) id);
 161                 add_id(&gcache, gr ? gr->gr_name : NULL, id, &gwidth);
 162         }
 163 }
 164
 165 static void
 166 free_namei(struct namei *nm)
 167 {
 168         while (nm) {
 169                 struct namei *next = nm->next;
 170                 free(nm->name);
 171                 free(nm->abslink);
 172                 free(nm);
 173                 nm = next;
 174         }
 175 }
 176
 177 static void
 178 readlink_to_namei(struct namei *nm, const char *path)
 179 {
 180         char sym[PATH_MAX];
 181         ssize_t sz;
 182         int isrel = 0;
 183
 184         sz = readlink(path, sym, sizeof(sym));
 185         if (sz < 1)
 186                 err(EXIT_FAILURE, _("failed to read symlink: %s"), path);
 187         if (*sym != '/') {
 188                 char *p = strrchr(path, '/');
 189
 190                 if (p) {
 191                         isrel = 1;
 192                         nm->relstart = p - path;
 193                         sz += nm->relstart + 1;
 194                 }
 195         }
 196         nm->abslink = xmalloc(sz + 1);
 197
 198         if (*sym != '/' && isrel) {
 199                 /* create the absolute path from the relative symlink */
 200                 memcpy(nm->abslink, path, nm->relstart);
 201                 *(nm->abslink + nm->relstart) = '/';
 202                 nm->relstart++;
 203                 memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart);
 204         } else
 205                 /* - absolute link (foo -> /path/bar)
 206                  * - or link without any subdir (foo -> bar)
 207                  */
 208                 memcpy(nm->abslink, sym, sz);
 209
 210         nm->abslink[sz] = '\0';
 211 }
 212
 213 static struct stat *
 214 dotdot_stat(const char *dirname, struct stat *st)
 215 {
 216         char *path;
 217         size_t len;
 218
 219 #define DOTDOTDIR       "/.."
 220
 221         if (!dirname)
 222                 return NULL;
 223
 224         len = strlen(dirname);
 225         path = xmalloc(len + sizeof(DOTDOTDIR));
 226
 227         memcpy(path, dirname, len);
 228         memcpy(path + len, DOTDOTDIR, sizeof(DOTDOTDIR));
 229
 230         if (stat(path, st))
 231                 err(EXIT_FAILURE, _("stat failed %s"), path);
 232         free(path);
 233         return st;
 234 }
 235
 236 static struct namei *
 237 new_namei(struct namei *parent, const char *path, const char *fname, int lev)
 238 {
 239         struct namei *nm;
 240
 241         if (!fname)
 242                 return NULL;
 243         nm = xcalloc(1, sizeof(*nm));
 244         if (parent)
 245                 parent->next = nm;
 246
 247         nm->level = lev;
 248         nm->name = xstrdup(fname);
 249
 250         nm->noent = (lstat(path, &nm->st) == -1);
 251         if (nm->noent)
 252                 return nm;
 253
 254         if (S_ISLNK(nm->st.st_mode))
 255                 readlink_to_namei(nm, path);
 256         if (flags & NAMEI_OWNERS) {
 257                 add_uid(nm->st.st_uid);
 258                 add_gid(nm->st.st_gid);
 259         }
 260
 261         if ((flags & NAMEI_MNTS) && S_ISDIR(nm->st.st_mode)) {
 262                 struct stat stbuf, *sb = NULL;
 263
 264                 if (parent && S_ISDIR(parent->st.st_mode))
 265                         sb = &parent->st;
 266                 else if (!parent || S_ISLNK(parent->st.st_mode))
 267                         sb = dotdot_stat(path, &stbuf);
 268
 269                 if (sb && (sb->st_dev != nm->st.st_dev ||   /* different device */
 270                            sb->st_ino == nm->st.st_ino))    /* root directory */
 271                         nm->mountpoint = 1;
 272         }
 273
 274         return nm;
 275 }
 276
 277 static struct namei *
 278 add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last)
 279 {
 280         struct namei *nm = NULL, *first = NULL;
 281         char *fname, *end, *path;
 282         int level = 0;
 283
 284         if (!orgpath)
 285                 return NULL;
 286         if (parent) {
 287                 nm = parent;
 288                 level = parent->level + 1;
 289         }
 290         path = xstrdup(orgpath);
 291         fname = path + start;
 292
 293         /* root directory */
 294         if (*fname == '/') {
 295                 while (*fname == '/')
 296                         fname++; /* eat extra '/' */
 297                 first = nm = new_namei(nm, "/", "/", level);
 298         }
 299
 300         for (end = fname; fname && end; ) {
 301                 /* set end of filename */
 302                 if (*fname) {
 303                         end = strchr(fname, '/');
 304                         if (end)
 305                                 *end = '\0';
 306
 307                         /* create a new entry */
 308                         nm = new_namei(nm, path, fname, level);
 309                 } else
 310                         end = NULL;
 311                 if (!first)
 312                         first = nm;
 313                 /* set begin of the next filename */
 314                 if (end) {
 315                         *end++ = '/';
 316                         while (*end == '/')
 317                                 end++; /* eat extra '/' */
 318                 }
 319                 fname = end;
 320         }
 321
 322         if (last)
 323                 *last = nm;
 324
 325         free(path);
 326
 327         return first;
 328 }
 329
 330 static int
 331 follow_symlinks(struct namei *nm)
 332 {
 333         int symcount = 0;
 334
 335         for (; nm; nm = nm->next) {
 336                 struct namei *next, *last;
 337
 338                 if (nm->noent)
 339                         continue;
 340                 if (!S_ISLNK(nm->st.st_mode))
 341                         continue;
 342                 if (++symcount > MAXSYMLINKS) {
 343                         /* drop the rest of the list */
 344                         free_namei(nm->next);
 345                         nm->next = NULL;
 346                         return -1;
 347                 }
 348                 next = nm->next;
 349                 nm->next = add_namei(nm, nm->abslink, nm->relstart, &last);
 350                 if (last)
 351                         last->next = next;
 352                 else
 353                         nm->next = next;
 354         }
 355         return 0;
 356 }
 357
 358 static int
 359 print_namei(struct namei *nm, char *path)
 360 {
 361         int i;
 362
 363         if (path)
 364                 printf("f: %s\n", path);
 365
 366         for (; nm; nm = nm->next) {
 367                 char md[11];
 368
 369                 if (nm->noent) {
 370                         printf(_("%s - No such file or directory\n"), nm->name);
 371                         return -1;
 372                 }
 373
 374                 strmode(nm->st.st_mode, md);
 375
 376                 if (nm->mountpoint)
 377                         md[0] = 'D';
 378
 379                 if (!(flags & NAMEI_VERTICAL)) {
 380                         for (i = 0; i < nm->level; i++)
 381                                 fputs("  ", stdout);
 382                         fputc(' ', stdout);
 383                 }
 384
 385                 if (flags & NAMEI_MODES)
 386                         printf("%s", md);
 387                 else
 388                         printf("%c", md[0]);
 389
 390                 if (flags & NAMEI_OWNERS) {
 391                         printf(" %-*s", uwidth,
 392                                 get_id(ucache, nm->st.st_uid)->name);
 393                         printf(" %-*s", gwidth,
 394                                 get_id(gcache, nm->st.st_gid)->name);
 395                 }
 396
 397                 if (flags & NAMEI_VERTICAL)
 398                         for (i = 0; i < nm->level; i++)
 399                                 fputs("  ", stdout);
 400
 401                 if (S_ISLNK(nm->st.st_mode))
 402                         printf(" %s -> %s\n", nm->name,
 403                                         nm->abslink + nm->relstart);
 404                 else
 405                         printf(" %s\n", nm->name);
 406         }
 407         return 0;
 408 }
 409
 410 static void usage(int rc)
 411 {
 412         const char *p = program_invocation_short_name;
 413         FILE *out = rc == EXIT_FAILURE ? stderr : stdout;
 414
 415         if (!*p)
 416                 p = "namei";
 417
 418         fputs(_("\nUsage:\n"), out);
 419         fprintf(out,
 420               _(" %s [options] pathname [pathname ...]\n"), p);
 421
 422         fputs(_("\nOptions:\n"), out);
 423         fputs(_(" -h, --help          displays this help text\n"
 424                 " -V, --version       output version information and exit\n"
 425                 " -x, --mountpoints   show mount point directories with a 'D'\n"
 426                 " -m, --modes         show the mode bits of each file\n"
 427                 " -o, --owners        show owner and group name of each file\n"
 428                 " -l, --long          use a long listing format (-m -o -v) \n"
 429                 " -n, --nosymlinks    don't follow symlinks\n"
 430                 " -v, --vertical      vertical align of modes and owners\n"), out);
 431
 432         fputs(_("\nFor more information see namei(1).\n"), out);
 433         exit(rc);
 434 }
 435
 436 static const struct option longopts[] =
 437 {
 438         { "help",       0, 0, 'h' },
 439         { "version",    0, 0, 'V' },
 440         { "mountpoints",0, 0, 'x' },
 441         { "modes",      0, 0, 'm' },
 442         { "owners",     0, 0, 'o' },
 443         { "long",       0, 0, 'l' },
 444         { "nolinks",    0, 0, 'n' },
 445         { "vertical",   0, 0, 'v' },
 446         { NULL,         0, 0, 0 },
 447 };
 448
 449 int
 450 main(int argc, char **argv)
 451 {
 452         int c;
 453         int rc = EXIT_SUCCESS;
 454
 455         setlocale(LC_ALL, "");
 456         bindtextdomain(PACKAGE, LOCALEDIR);
 457         textdomain(PACKAGE);
 458         atexit(close_stdout);
 459
 460         while ((c = getopt_long(argc, argv, "hVlmnovx", longopts, NULL)) != -1) {
 461                 switch(c) {
 462                 case 'h':
 463                         usage(EXIT_SUCCESS);
 464                         break;
 465                 case 'V':
 466                         printf(UTIL_LINUX_VERSION);
 467                         return EXIT_SUCCESS;
 468                 case 'l':
 469                         flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL);
 470                         break;
 471                 case 'm':
 472                         flags |= NAMEI_MODES;
 473                         break;
 474                 case 'n':
 475                         flags |= NAMEI_NOLINKS;
 476                         break;
 477                 case 'o':
 478                         flags |= NAMEI_OWNERS;
 479                         break;
 480                 case 'x':
 481                         flags |= NAMEI_MNTS;
 482                         break;
 483                 case 'v':
 484                         flags |= NAMEI_VERTICAL;
 485                         break;
 486                 default:
 487                         usage(EXIT_FAILURE);
 488                 }
 489         }
 490
 491         if (optind == argc) {
 492                 warnx(_("pathname argument is missing"));
 493                 usage(EXIT_FAILURE);
 494         }
 495
 496         for(; optind < argc; optind++) {
 497                 char *path = argv[optind];
 498                 struct namei *nm = NULL;
 499                 struct stat st;
 500
 501                 if (stat(path, &st) != 0)
 502                         rc = EXIT_FAILURE;
 503
 504                 nm = add_namei(NULL, path, 0, NULL);
 505                 if (nm) {
 506                         int sml = 0;
 507                         if (!(flags & NAMEI_NOLINKS))
 508                                 sml = follow_symlinks(nm);
 509                         if (print_namei(nm, path)) {
 510                                 rc = EXIT_FAILURE;
 511                                 continue;
 512                         }
 513                         free_namei(nm);
 514                         if (sml == -1) {
 515                                 rc = EXIT_FAILURE;
 516                                 warnx(_("%s: exceeded limit of symlinks"), path);
 517                                 continue;
 518                         }
 519                 }
 520         }
 521
 522         free_idcache(ucache);
 523         free_idcache(gcache);
 524
 525         return rc;
 526 }
 527