misc-utils/namei.c

   1 /*
   2  * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
   3  *
   4  * This file is part of util-linux-ng.
   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 #include <stdio.h>
  23 #include <unistd.h>
  24 #include <getopt.h>
  25 #include <string.h>
  26 #include <strings.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 <err.h>
  33 #include <pwd.h>
  34 #include <grp.h>
  35
  36 #include "c.h"
  37 #include "nls.h"
  38 #include "widechar.h"
  39
  40 #ifndef MAXSYMLINKS
  41 #define MAXSYMLINKS 256
  42 #endif
  43
  44 #ifndef LOGIN_NAME_MAX
  45 #define LOGIN_NAME_MAX 256
  46 #endif
  47
  48 #define NAMEI_NOLINKS   (1 << 1)
  49 #define NAMEI_MODES     (1 << 2)
  50 #define NAMEI_MNTS      (1 << 3)
  51 #define NAMEI_OWNERS    (1 << 4)
  52 #define NAMEI_VERTICAL  (1 << 5)
  53
  54
  55 struct namei {
  56         struct stat     st;             /* item lstat() */
  57         char            *name;          /* item name */
  58         char            *abslink;       /* absolute symlink path */
  59         int             relstart;       /* offset of relative path in 'abslink' */
  60         struct namei    *next;          /* next item */
  61         int             level;
  62         int             mountpoint;     /* is mount point */
  63 };
  64
  65 struct idcache {
  66         unsigned long int       id;
  67         char                    *name;
  68         struct idcache          *next;
  69 };
  70
  71 static int flags;
  72 static int uwidth;              /* maximal width of username */
  73 static int gwidth;              /* maximal width of groupname */
  74 static struct idcache *gcache;  /* groupnames */
  75 static struct idcache *ucache;  /* usernames */
  76
  77 static struct idcache *
  78 get_id(struct idcache *ic, unsigned long int id)
  79 {
  80         while(ic) {
  81                 if (ic->id == id)
  82                         return ic;
  83                 ic = ic->next;
  84         }
  85         return NULL;
  86 }
  87
  88 static void
  89 free_idcache(struct idcache *ic)
  90 {
  91         while(ic) {
  92                 struct idcache *next = ic->next;
  93                 free(ic->name);
  94                 free(ic);
  95                 ic = next;
  96         }
  97 }
  98
  99 static void
 100 add_id(struct idcache **ic, char *name, unsigned long int id, int *width)
 101 {
 102         struct idcache *nc, *x;
 103         int w = 0;
 104
 105         nc = calloc(1, sizeof(*nc));
 106         if (!nc)
 107                 goto alloc_err;
 108         nc->id = id;
 109
 110         if (name) {
 111 #ifdef HAVE_WIDECHAR
 112                 wchar_t wc[LOGIN_NAME_MAX + 1];
 113
 114                 if (mbstowcs(wc, name, LOGIN_NAME_MAX) > 0) {
 115                         wc[LOGIN_NAME_MAX] = '\0';
 116                         w = wcswidth(wc, LOGIN_NAME_MAX);
 117                 }
 118                 else
 119 #endif
 120                         w = strlen(name);
 121         }
 122         /* note, we ignore names with non-printable widechars */
 123         if (w > 0)
 124                 nc->name = strdup(name);
 125         else if (asprintf(&nc->name, "%lu", id) == -1)
 126                 nc->name = NULL;
 127         if (!nc->name)
 128                 goto alloc_err;
 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 = strlen(nc->name);
 139         *width = *width < w ? w : *width;
 140
 141         return;
 142 alloc_err:
 143         err(EXIT_FAILURE, _("out of memory?"));
 144 }
 145
 146 static void
 147 add_uid(unsigned long int id)
 148 {
 149         struct idcache *ic = get_id(ucache, id);
 150
 151         if (!ic) {
 152                 struct passwd *pw = getpwuid((uid_t) id);
 153                 add_id(&ucache, pw ? pw->pw_name : NULL, id, &uwidth);
 154         }
 155 }
 156
 157 static void
 158 add_gid(unsigned long int id)
 159 {
 160         struct idcache *ic = get_id(gcache, id);
 161
 162         if (!ic) {
 163                 struct group *gr = getgrgid((gid_t) id);
 164                 add_id(&gcache, gr ? gr->gr_name : NULL, id, &gwidth);
 165         }
 166 }
 167
 168 static void
 169 free_namei(struct namei *nm)
 170 {
 171         while (nm) {
 172                 struct namei *next = nm->next;
 173                 free(nm->name);
 174                 free(nm->abslink);
 175                 free(nm);
 176                 nm = next;
 177         }
 178 }
 179
 180 static void
 181 readlink_to_namei(struct namei *nm, const char *path)
 182 {
 183         char sym[PATH_MAX];
 184         size_t sz;
 185
 186         sz = readlink(path, sym, sizeof(sym));
 187         if (sz < 1)
 188                 err(EXIT_FAILURE, _("failed to read symlink: %s"), path);
 189         if (*sym != '/') {
 190                 char *p = strrchr(path, '/');
 191
 192                 nm->relstart = p ? p - path : 0;
 193                 if (nm->relstart)
 194                         sz += nm->relstart + 1;
 195         }
 196         nm->abslink = malloc(sz + 1);
 197         if (!nm->abslink)
 198                 err(EXIT_FAILURE, _("out of memory?"));
 199
 200         if (*sym != '/' && nm->relstart) {
 201                 /* create the absolute path from the relative symlink */
 202                 memcpy(nm->abslink, path, nm->relstart);
 203                 *(nm->abslink + nm->relstart) = '/';
 204                 nm->relstart++;
 205                 memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart);
 206         } else
 207                 memcpy(nm->abslink, sym, sz);
 208         nm->abslink[sz] = '\0';
 209 }
 210
 211 static struct stat *
 212 dotdot_stat(const char *dirname, struct stat *st)
 213 {
 214         char *path;
 215         size_t len;
 216
 217 #define DOTDOTDIR       "/.."
 218
 219         if (!dirname)
 220                 return NULL;
 221
 222         len = strlen(dirname);
 223         path = malloc(len + sizeof(DOTDOTDIR));
 224         if (!path)
 225                 err(EXIT_FAILURE, _("out of memory?"));
 226
 227         memcpy(path, dirname, len);
 228         memcpy(path + len, DOTDOTDIR, sizeof(DOTDOTDIR));
 229
 230         if (stat(path, st))
 231                 err(EXIT_FAILURE, _("could not stat '%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 = calloc(1, sizeof(*nm));
 244         if (!nm)
 245                 err(EXIT_FAILURE, _("out of memory?"));
 246         if (parent)
 247                 parent->next = nm;
 248
 249         nm->level = lev;
 250         nm->name = strdup(fname);
 251         if (!nm->name)
 252                 err(EXIT_FAILURE, _("out of memory?"));
 253         if (lstat(path, &nm->st) == -1)
 254                 err(EXIT_FAILURE, _("could not stat '%s'"), path);
 255
 256         if (S_ISLNK(nm->st.st_mode))
 257                 readlink_to_namei(nm, path);
 258         if (flags & NAMEI_OWNERS) {
 259                 add_uid(nm->st.st_uid);
 260                 add_gid(nm->st.st_gid);
 261         }
 262
 263         if ((flags & NAMEI_MNTS) && S_ISDIR(nm->st.st_mode)) {
 264                 struct stat stbuf, *sb = NULL;
 265
 266                 if (parent && S_ISDIR(parent->st.st_mode))
 267                         sb = &parent->st;
 268                 else if (!parent || S_ISLNK(parent->st.st_mode))
 269                         sb = dotdot_stat(path, &stbuf);
 270
 271                 if (sb && (sb->st_dev != nm->st.st_dev ||   /* different device */
 272                            sb->st_ino == nm->st.st_ino))    /* root directory */
 273                         nm->mountpoint = 1;
 274         }
 275
 276         return nm;
 277 }
 278
 279 static struct namei *
 280 add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last)
 281 {
 282         struct namei *nm = NULL, *first = NULL;
 283         char *fname, *end, *path;
 284         int level = 0;
 285
 286         if (!orgpath)
 287                 return NULL;
 288         if (parent) {
 289                 nm = parent;
 290                 level = parent->level + 1;
 291         }
 292         path = strdup(orgpath);
 293         if (!path)
 294                 err(EXIT_FAILURE, _("out of memory?"));
 295         fname = path + start;
 296
 297         /* root directory */
 298         if (*fname == '/') {
 299                 while (*fname == '/')
 300                         fname++; /* eat extra '/' */
 301                 first = nm = new_namei(nm, "/", "/", level);
 302         }
 303
 304         for (end = fname; fname && end; ) {
 305                 /* set end of filename */
 306                 if (*fname) {
 307                         end = strchr(fname, '/');
 308                         if (end)
 309                                 *end = '\0';
 310
 311                         /* create a new entry */
 312                         nm = new_namei(nm, path, fname, level);
 313                 } else
 314                         end = NULL;
 315                 if (!first)
 316                         first = nm;
 317                 /* set begin of the next filename */
 318                 if (end) {
 319                         *end++ = '/';
 320                         while (*end == '/')
 321                                 end++; /* eat extra '/' */
 322                 }
 323                 fname = end;
 324         }
 325
 326         if (last)
 327                 *last = nm;
 328
 329         free(path);
 330
 331         return first;
 332 }
 333
 334
 335 static int
 336 follow_symlinks(struct namei *nm)
 337 {
 338         int symcount = 0;
 339
 340         for (; nm; nm = nm->next) {
 341                 struct namei *next, *last;
 342
 343                 if (!S_ISLNK(nm->st.st_mode))
 344                         continue;
 345                 if (++symcount > MAXSYMLINKS) {
 346                         /* drop the rest of the list */
 347                         free_namei(nm->next);
 348                         nm->next = NULL;
 349                         return -1;
 350                 }
 351                 next = nm->next;
 352                 nm->next = add_namei(nm, nm->abslink, nm->relstart, &last);
 353                 if (last)
 354                         last->next = next;
 355                 else
 356                         nm->next = next;
 357         }
 358         return 0;
 359 }
 360
 361 static void
 362 strmode(mode_t mode, char *str)
 363 {
 364         if (S_ISDIR(mode))
 365                 str[0] = 'd';
 366         else if (S_ISLNK(mode))
 367                 str[0] = 'l';
 368         else if (S_ISCHR(mode))
 369                 str[0] = 'c';
 370         else if (S_ISBLK(mode))
 371                 str[0] = 'b';
 372         else if (S_ISSOCK(mode))
 373                 str[0] = 's';
 374         else if (S_ISFIFO(mode))
 375                 str[0] = 'p';
 376         else if (S_ISREG(mode))
 377                 str[0] = '-';
 378
 379         str[1] = mode & S_IRUSR ? 'r' : '-';
 380         str[2] = mode & S_IWUSR ? 'w' : '-';
 381         str[3] = (mode & S_ISUID
 382                 ? (mode & S_IXUSR ? 's' : 'S')
 383                 : (mode & S_IXUSR ? 'x' : '-'));
 384         str[4] = mode & S_IRGRP ? 'r' : '-';
 385         str[5] = mode & S_IWGRP ? 'w' : '-';
 386         str[6] = (mode & S_ISGID
 387                 ? (mode & S_IXGRP ? 's' : 'S')
 388                 : (mode & S_IXGRP ? 'x' : '-'));
 389         str[7] = mode & S_IROTH ? 'r' : '-';
 390         str[8] = mode & S_IWOTH ? 'w' : '-';
 391         str[9] = (mode & S_ISVTX
 392                 ? (mode & S_IXOTH ? 't' : 'T')
 393                 : (mode & S_IXOTH ? 'x' : '-'));
 394         str[10] = '\0';
 395 }
 396
 397 static void
 398 print_namei(struct namei *nm, char *path)
 399 {
 400         struct namei *prev = NULL;
 401         int i;
 402
 403         if (path)
 404                 printf("f: %s\n", path);
 405
 406         for (; nm; prev = nm, nm = nm->next) {
 407                 char md[11];
 408
 409                 strmode(nm->st.st_mode, md);
 410
 411                 if (nm->mountpoint)
 412                         md[0] = 'D';
 413
 414                 if (!(flags & NAMEI_VERTICAL)) {
 415                         for (i = 0; i < nm->level; i++)
 416                                 fputs("  ", stdout);
 417                         fputc(' ', stdout);
 418                 }
 419
 420                 if (flags & NAMEI_MODES)
 421                         printf("%s", md);
 422                 else
 423                         printf("%c", md[0]);
 424
 425                 if (flags & NAMEI_OWNERS) {
 426                         printf(" %-*s", uwidth,
 427                                 get_id(ucache, nm->st.st_uid)->name);
 428                         printf(" %-*s", gwidth,
 429                                 get_id(gcache, nm->st.st_gid)->name);
 430                 }
 431
 432                 if (flags & NAMEI_VERTICAL)
 433                         for (i = 0; i < nm->level; i++)
 434                                 fputs("  ", stdout);
 435
 436                 if (S_ISLNK(nm->st.st_mode))
 437                         printf(" %s -> %s\n", nm->name,
 438                                         nm->abslink + nm->relstart);
 439                 else
 440                         printf(" %s\n", nm->name);
 441         }
 442 }
 443
 444 static void
 445 usage(int rc)
 446 {
 447         const char *p = program_invocation_short_name;
 448
 449         if (!*p)
 450                 p = "namei";
 451
 452         printf(_("\nUsage: %s [options] pathname [pathname ...]\n"), p);
 453         printf(_("\nOptions:\n"));
 454
 455         printf(_(
 456         " -h, --help          displays this help text\n"
 457         " -x, --mountpoints   show mount point directories with a 'D'\n"
 458         " -m, --modes         show the mode bits of each file\n"
 459         " -o, --owners        show owner and group name of each file\n"
 460         " -l, --long          use a long listing format (-m -o -v) \n"
 461         " -n, --nosymlinks    don't follow symlinks\n"
 462         " -v, --vertical      vertical align of modes and owners\n"));
 463
 464         printf(_("\nFor more information see namei(1).\n"));
 465         exit(rc);
 466 }
 467
 468 struct option longopts[] =
 469 {
 470         { "help",       0, 0, 'h' },
 471         { "mountpoints",0, 0, 'x' },
 472         { "modes",      0, 0, 'm' },
 473         { "owners",     0, 0, 'o' },
 474         { "long",       0, 0, 'l' },
 475         { "nolinks",    0, 0, 'n' },
 476         { "vertical",   0, 0, 'v' },
 477         { NULL,         0, 0, 0 },
 478 };
 479
 480 int
 481 main(int argc, char **argv)
 482 {
 483         extern int optind;
 484         int c;
 485
 486         setlocale(LC_ALL, "");
 487         bindtextdomain(PACKAGE, LOCALEDIR);
 488         textdomain(PACKAGE);
 489
 490         if (argc < 2)
 491                 usage(EXIT_FAILURE);
 492
 493         while ((c = getopt_long(argc, argv, "+h?lmnovx", longopts, NULL)) != -1) {
 494                 switch(c) {
 495                 case 'h':
 496                 case '?':
 497                         usage(EXIT_SUCCESS);
 498                         break;
 499                 case 'l':
 500                         flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL);
 501                         break;
 502                 case 'm':
 503                         flags |= NAMEI_MODES;
 504                         break;
 505                 case 'n':
 506                         flags |= NAMEI_NOLINKS;
 507                         break;
 508                 case 'o':
 509                         flags |= NAMEI_OWNERS;
 510                         break;
 511                 case 'x':
 512                         flags |= NAMEI_MNTS;
 513                         break;
 514                 case 'v':
 515                         flags |= NAMEI_VERTICAL;
 516                 }
 517         }
 518
 519         for(; optind < argc; optind++) {
 520                 char *path = argv[optind];
 521                 struct namei *nm = NULL;
 522                 struct stat st;
 523
 524                 if (stat(path, &st) != 0)
 525                         err(EXIT_FAILURE, _("failed to stat: %s"), path);
 526
 527                 nm = add_namei(NULL, path, 0, NULL);
 528                 if (nm) {
 529                         int sml = 0;
 530                         if (!(flags & NAMEI_NOLINKS))
 531                                 sml = follow_symlinks(nm);
 532                         print_namei(nm, path);
 533                         free_namei(nm);
 534                         if (sml == -1)
 535                                 errx(EXIT_FAILURE,
 536                                         _("%s: exceeded limit of symlinks"),
 537                                         path);
 538                 }
 539         }
 540
 541         free_idcache(ucache);
 542         free_idcache(gcache);
 543
 544         return EXIT_SUCCESS;
 545 }
 546