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
 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                 nm->relstart = p ? p - path : 0;
 191                 if (nm->relstart)
 192                         sz += nm->relstart + 1;
 193         }
 194         nm->abslink = xmalloc(sz + 1);
 195
 196         if (*sym != '/' && nm->relstart) {
 197                 /* create the absolute path from the relative symlink */
 198                 memcpy(nm->abslink, path, nm->relstart);
 199                 *(nm->abslink + nm->relstart) = '/';
 200                 nm->relstart++;
 201                 memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart);
 202         } else
 203                 memcpy(nm->abslink, sym, sz);
 204         nm->abslink[sz] = '\0';
 205 }
 206
 207 static struct stat *
 208 dotdot_stat(const char *dirname, struct stat *st)
 209 {
 210         char *path;
 211         size_t len;
 212
 213 #define DOTDOTDIR       "/.."
 214
 215         if (!dirname)
 216                 return NULL;
 217
 218         len = strlen(dirname);
 219         path = xmalloc(len + sizeof(DOTDOTDIR));
 220
 221         memcpy(path, dirname, len);
 222         memcpy(path + len, DOTDOTDIR, sizeof(DOTDOTDIR));
 223
 224         if (stat(path, st))
 225                 err(EXIT_FAILURE, _("could not stat '%s'"), path);
 226         free(path);
 227         return st;
 228 }
 229
 230 static struct namei *
 231 new_namei(struct namei *parent, const char *path, const char *fname, int lev)
 232 {
 233         struct namei *nm;
 234
 235         if (!fname)
 236                 return NULL;
 237         nm = xcalloc(1, sizeof(*nm));
 238         if (parent)
 239                 parent->next = nm;
 240
 241         nm->level = lev;
 242         nm->name = xstrdup(fname);
 243
 244         nm->noent = (lstat(path, &nm->st) == -1);
 245         if (nm->noent)
 246                 return nm;
 247
 248         if (S_ISLNK(nm->st.st_mode))
 249                 readlink_to_namei(nm, path);
 250         if (flags & NAMEI_OWNERS) {
 251                 add_uid(nm->st.st_uid);
 252                 add_gid(nm->st.st_gid);
 253         }
 254
 255         if ((flags & NAMEI_MNTS) && S_ISDIR(nm->st.st_mode)) {
 256                 struct stat stbuf, *sb = NULL;
 257
 258                 if (parent && S_ISDIR(parent->st.st_mode))
 259                         sb = &parent->st;
 260                 else if (!parent || S_ISLNK(parent->st.st_mode))
 261                         sb = dotdot_stat(path, &stbuf);
 262
 263                 if (sb && (sb->st_dev != nm->st.st_dev ||   /* different device */
 264                            sb->st_ino == nm->st.st_ino))    /* root directory */
 265                         nm->mountpoint = 1;
 266         }
 267
 268         return nm;
 269 }
 270
 271 static struct namei *
 272 add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last)
 273 {
 274         struct namei *nm = NULL, *first = NULL;
 275         char *fname, *end, *path;
 276         int level = 0;
 277
 278         if (!orgpath)
 279                 return NULL;
 280         if (parent) {
 281                 nm = parent;
 282                 level = parent->level + 1;
 283         }
 284         path = xstrdup(orgpath);
 285         fname = path + start;
 286
 287         /* root directory */
 288         if (*fname == '/') {
 289                 while (*fname == '/')
 290                         fname++; /* eat extra '/' */
 291                 first = nm = new_namei(nm, "/", "/", level);
 292         }
 293
 294         for (end = fname; fname && end; ) {
 295                 /* set end of filename */
 296                 if (*fname) {
 297                         end = strchr(fname, '/');
 298                         if (end)
 299                                 *end = '\0';
 300
 301                         /* create a new entry */
 302                         nm = new_namei(nm, path, fname, level);
 303                 } else
 304                         end = NULL;
 305                 if (!first)
 306                         first = nm;
 307                 /* set begin of the next filename */
 308                 if (end) {
 309                         *end++ = '/';
 310                         while (*end == '/')
 311                                 end++; /* eat extra '/' */
 312                 }
 313                 fname = end;
 314         }
 315
 316         if (last)
 317                 *last = nm;
 318
 319         free(path);
 320
 321         return first;
 322 }
 323
 324 static int
 325 follow_symlinks(struct namei *nm)
 326 {
 327         int symcount = 0;
 328
 329         for (; nm; nm = nm->next) {
 330                 struct namei *next, *last;
 331
 332                 if (nm->noent)
 333                         continue;
 334                 if (!S_ISLNK(nm->st.st_mode))
 335                         continue;
 336                 if (++symcount > MAXSYMLINKS) {
 337                         /* drop the rest of the list */
 338                         free_namei(nm->next);
 339                         nm->next = NULL;
 340                         return -1;
 341                 }
 342                 next = nm->next;
 343                 nm->next = add_namei(nm, nm->abslink, nm->relstart, &last);
 344                 if (last)
 345                         last->next = next;
 346                 else
 347                         nm->next = next;
 348         }
 349         return 0;
 350 }
 351
 352 static int
 353 print_namei(struct namei *nm, char *path)
 354 {
 355         int i;
 356
 357         if (path)
 358                 printf("f: %s\n", path);
 359
 360         for (; nm; nm = nm->next) {
 361                 char md[11];
 362
 363                 if (nm->noent) {
 364                         printf(_("%s - No such file or directory\n"), nm->name);
 365                         return -1;
 366                 }
 367
 368                 strmode(nm->st.st_mode, md);
 369
 370                 if (nm->mountpoint)
 371                         md[0] = 'D';
 372
 373                 if (!(flags & NAMEI_VERTICAL)) {
 374                         for (i = 0; i < nm->level; i++)
 375                                 fputs("  ", stdout);
 376                         fputc(' ', stdout);
 377                 }
 378
 379                 if (flags & NAMEI_MODES)
 380                         printf("%s", md);
 381                 else
 382                         printf("%c", md[0]);
 383
 384                 if (flags & NAMEI_OWNERS) {
 385                         printf(" %-*s", uwidth,
 386                                 get_id(ucache, nm->st.st_uid)->name);
 387                         printf(" %-*s", gwidth,
 388                                 get_id(gcache, nm->st.st_gid)->name);
 389                 }
 390
 391                 if (flags & NAMEI_VERTICAL)
 392                         for (i = 0; i < nm->level; i++)
 393                                 fputs("  ", stdout);
 394
 395                 if (S_ISLNK(nm->st.st_mode))
 396                         printf(" %s -> %s\n", nm->name,
 397                                         nm->abslink + nm->relstart);
 398                 else
 399                         printf(" %s\n", nm->name);
 400         }
 401         return 0;
 402 }
 403
 404 static void usage(int rc)
 405 {
 406         const char *p = program_invocation_short_name;
 407         FILE *out = rc == EXIT_FAILURE ? stderr : stdout;
 408
 409         if (!*p)
 410                 p = "namei";
 411
 412         fputs(_("\nUsage:\n"), out);
 413         fprintf(out,
 414               _(" %s [options] pathname [pathname ...]\n"), p);
 415
 416         fputs(_("\nOptions:\n"), out);
 417         fputs(_(" -h, --help          displays this help text\n"
 418                 " -V, --version       output version information and exit\n"
 419                 " -x, --mountpoints   show mount point directories with a 'D'\n"
 420                 " -m, --modes         show the mode bits of each file\n"
 421                 " -o, --owners        show owner and group name of each file\n"
 422                 " -l, --long          use a long listing format (-m -o -v) \n"
 423                 " -n, --nosymlinks    don't follow symlinks\n"
 424                 " -v, --vertical      vertical align of modes and owners\n"), out);
 425
 426         fputs(_("\nFor more information see namei(1).\n"), out);
 427         exit(rc);
 428 }
 429
 430 static const struct option longopts[] =
 431 {
 432         { "help",       0, 0, 'h' },
 433         { "version",    0, 0, 'V' },
 434         { "mountpoints",0, 0, 'x' },
 435         { "modes",      0, 0, 'm' },
 436         { "owners",     0, 0, 'o' },
 437         { "long",       0, 0, 'l' },
 438         { "nolinks",    0, 0, 'n' },
 439         { "vertical",   0, 0, 'v' },
 440         { NULL,         0, 0, 0 },
 441 };
 442
 443 int
 444 main(int argc, char **argv)
 445 {
 446         int c;
 447         int rc = EXIT_SUCCESS;
 448
 449         setlocale(LC_ALL, "");
 450         bindtextdomain(PACKAGE, LOCALEDIR);
 451         textdomain(PACKAGE);
 452         atexit(close_stdout);
 453
 454         while ((c = getopt_long(argc, argv, "hVlmnovx", longopts, NULL)) != -1) {
 455                 switch(c) {
 456                 case 'h':
 457                         usage(EXIT_SUCCESS);
 458                         break;
 459                 case 'V':
 460                         printf(_("%s from %s\n"), program_invocation_short_name,
 461                                                   PACKAGE_STRING);
 462                         return EXIT_SUCCESS;
 463                 case 'l':
 464                         flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL);
 465                         break;
 466                 case 'm':
 467                         flags |= NAMEI_MODES;
 468                         break;
 469                 case 'n':
 470                         flags |= NAMEI_NOLINKS;
 471                         break;
 472                 case 'o':
 473                         flags |= NAMEI_OWNERS;
 474                         break;
 475                 case 'x':
 476                         flags |= NAMEI_MNTS;
 477                         break;
 478                 case 'v':
 479                         flags |= NAMEI_VERTICAL;
 480                         break;
 481                 default:
 482                         usage(EXIT_FAILURE);
 483                 }
 484         }
 485
 486         if (optind == argc) {
 487                 warnx(_("pathname argument is missing"));
 488                 usage(EXIT_FAILURE);
 489         }
 490
 491         for(; optind < argc; optind++) {
 492                 char *path = argv[optind];
 493                 struct namei *nm = NULL;
 494                 struct stat st;
 495
 496                 if (stat(path, &st) != 0)
 497                         rc = EXIT_FAILURE;
 498
 499                 nm = add_namei(NULL, path, 0, NULL);
 500                 if (nm) {
 501                         int sml = 0;
 502                         if (!(flags & NAMEI_NOLINKS))
 503                                 sml = follow_symlinks(nm);
 504                         if (print_namei(nm, path)) {
 505                                 rc = EXIT_FAILURE;
 506                                 continue;
 507                         }
 508                         free_namei(nm);
 509                         if (sml == -1) {
 510                                 rc = EXIT_FAILURE;
 511                                 warnx(_("%s: exceeded limit of symlinks"), path);
 512                                 continue;
 513                         }
 514                 }
 515         }
 516
 517         free_idcache(ucache);
 518         free_idcache(gcache);
 519
 520         return rc;
 521 }
 522