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
  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 = calloc(1, sizeof(*nc));
 109         if (!nc)
 110                 goto alloc_err;
 111         nc->id = id;
 112
 113         if (name) {
 114 #ifdef HAVE_WIDECHAR
 115                 wchar_t wc[LOGIN_NAME_MAX + 1];
 116
 117                 if (mbstowcs(wc, name, LOGIN_NAME_MAX) > 0) {
 118                         wc[LOGIN_NAME_MAX] = '\0';
 119                         w = wcswidth(wc, LOGIN_NAME_MAX);
 120                 }
 121                 else
 122 #endif
 123                         w = strlen(name);
 124         }
 125         /* note, we ignore names with non-printable widechars */
 126         if (w > 0)
 127                 nc->name = strdup(name);
 128         else if (asprintf(&nc->name, "%lu", id) == -1)
 129                 nc->name = NULL;
 130         if (!nc->name)
 131                 goto alloc_err;
 132
 133         for (x = *ic; x && x->next; x = x->next);
 134
 135         /* add 'nc' at end of the 'ic' list */
 136         if (x)
 137                 x->next = nc;
 138         else
 139                 *ic = nc;
 140         if (w <= 0)
 141                 w = strlen(nc->name);
 142         *width = *width < w ? w : *width;
 143
 144         return;
 145 alloc_err:
 146         err(EXIT_FAILURE, _("out of memory?"));
 147 }
 148
 149 static void
 150 add_uid(unsigned long int id)
 151 {
 152         struct idcache *ic = get_id(ucache, id);
 153
 154         if (!ic) {
 155                 struct passwd *pw = getpwuid((uid_t) id);
 156                 add_id(&ucache, pw ? pw->pw_name : NULL, id, &uwidth);
 157         }
 158 }
 159
 160 static void
 161 add_gid(unsigned long int id)
 162 {
 163         struct idcache *ic = get_id(gcache, id);
 164
 165         if (!ic) {
 166                 struct group *gr = getgrgid((gid_t) id);
 167                 add_id(&gcache, gr ? gr->gr_name : NULL, id, &gwidth);
 168         }
 169 }
 170
 171 static void
 172 free_namei(struct namei *nm)
 173 {
 174         while (nm) {
 175                 struct namei *next = nm->next;
 176                 free(nm->name);
 177                 free(nm->abslink);
 178                 free(nm);
 179                 nm = next;
 180         }
 181 }
 182
 183 static void
 184 readlink_to_namei(struct namei *nm, const char *path)
 185 {
 186         char sym[PATH_MAX];
 187         ssize_t sz;
 188
 189         sz = readlink(path, sym, sizeof(sym));
 190         if (sz < 1)
 191                 err(EXIT_FAILURE, _("failed to read symlink: %s"), path);
 192         if (*sym != '/') {
 193                 char *p = strrchr(path, '/');
 194
 195                 nm->relstart = p ? p - path : 0;
 196                 if (nm->relstart)
 197                         sz += nm->relstart + 1;
 198         }
 199         nm->abslink = xmalloc(sz + 1);
 200
 201         if (*sym != '/' && nm->relstart) {
 202                 /* create the absolute path from the relative symlink */
 203                 memcpy(nm->abslink, path, nm->relstart);
 204                 *(nm->abslink + nm->relstart) = '/';
 205                 nm->relstart++;
 206                 memcpy(nm->abslink + nm->relstart, sym, sz - nm->relstart);
 207         } else
 208                 memcpy(nm->abslink, sym, sz);
 209         nm->abslink[sz] = '\0';
 210 }
 211
 212 static struct stat *
 213 dotdot_stat(const char *dirname, struct stat *st)
 214 {
 215         char *path;
 216         size_t len;
 217
 218 #define DOTDOTDIR       "/.."
 219
 220         if (!dirname)
 221                 return NULL;
 222
 223         len = strlen(dirname);
 224         path = malloc(len + sizeof(DOTDOTDIR));
 225         if (!path)
 226                 err(EXIT_FAILURE, _("out of memory?"));
 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 = calloc(1, sizeof(*nm));
 245         if (!nm)
 246                 err(EXIT_FAILURE, _("out of memory?"));
 247         if (parent)
 248                 parent->next = nm;
 249
 250         nm->level = lev;
 251         nm->name = strdup(fname);
 252         if (!nm->name)
 253                 err(EXIT_FAILURE, _("out of memory?"));
 254
 255         nm->noent = (lstat(path, &nm->st) == -1);
 256         if (nm->noent)
 257                 return nm;
 258
 259         if (S_ISLNK(nm->st.st_mode))
 260                 readlink_to_namei(nm, path);
 261         if (flags & NAMEI_OWNERS) {
 262                 add_uid(nm->st.st_uid);
 263                 add_gid(nm->st.st_gid);
 264         }
 265
 266         if ((flags & NAMEI_MNTS) && S_ISDIR(nm->st.st_mode)) {
 267                 struct stat stbuf, *sb = NULL;
 268
 269                 if (parent && S_ISDIR(parent->st.st_mode))
 270                         sb = &parent->st;
 271                 else if (!parent || S_ISLNK(parent->st.st_mode))
 272                         sb = dotdot_stat(path, &stbuf);
 273
 274                 if (sb && (sb->st_dev != nm->st.st_dev ||   /* different device */
 275                            sb->st_ino == nm->st.st_ino))    /* root directory */
 276                         nm->mountpoint = 1;
 277         }
 278
 279         return nm;
 280 }
 281
 282 static struct namei *
 283 add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last)
 284 {
 285         struct namei *nm = NULL, *first = NULL;
 286         char *fname, *end, *path;
 287         int level = 0;
 288
 289         if (!orgpath)
 290                 return NULL;
 291         if (parent) {
 292                 nm = parent;
 293                 level = parent->level + 1;
 294         }
 295         path = strdup(orgpath);
 296         if (!path)
 297                 err(EXIT_FAILURE, _("out of memory?"));
 298         fname = path + start;
 299
 300         /* root directory */
 301         if (*fname == '/') {
 302                 while (*fname == '/')
 303                         fname++; /* eat extra '/' */
 304                 first = nm = new_namei(nm, "/", "/", level);
 305         }
 306
 307         for (end = fname; fname && end; ) {
 308                 /* set end of filename */
 309                 if (*fname) {
 310                         end = strchr(fname, '/');
 311                         if (end)
 312                                 *end = '\0';
 313
 314                         /* create a new entry */
 315                         nm = new_namei(nm, path, fname, level);
 316                 } else
 317                         end = NULL;
 318                 if (!first)
 319                         first = nm;
 320                 /* set begin of the next filename */
 321                 if (end) {
 322                         *end++ = '/';
 323                         while (*end == '/')
 324                                 end++; /* eat extra '/' */
 325                 }
 326                 fname = end;
 327         }
 328
 329         if (last)
 330                 *last = nm;
 331
 332         free(path);
 333
 334         return first;
 335 }
 336
 337 static int
 338 follow_symlinks(struct namei *nm)
 339 {
 340         int symcount = 0;
 341
 342         for (; nm; nm = nm->next) {
 343                 struct namei *next, *last;
 344
 345                 if (nm->noent)
 346                         continue;
 347                 if (!S_ISLNK(nm->st.st_mode))
 348                         continue;
 349                 if (++symcount > MAXSYMLINKS) {
 350                         /* drop the rest of the list */
 351                         free_namei(nm->next);
 352                         nm->next = NULL;
 353                         return -1;
 354                 }
 355                 next = nm->next;
 356                 nm->next = add_namei(nm, nm->abslink, nm->relstart, &last);
 357                 if (last)
 358                         last->next = next;
 359                 else
 360                         nm->next = next;
 361         }
 362         return 0;
 363 }
 364
 365 static int
 366 print_namei(struct namei *nm, char *path)
 367 {
 368         int i;
 369
 370         if (path)
 371                 printf("f: %s\n", path);
 372
 373         for (; nm; nm = nm->next) {
 374                 char md[11];
 375
 376                 if (nm->noent) {
 377                         printf(_("%s - No such file or directory\n"), nm->name);
 378                         return -1;
 379                 }
 380
 381                 strmode(nm->st.st_mode, md);
 382
 383                 if (nm->mountpoint)
 384                         md[0] = 'D';
 385
 386                 if (!(flags & NAMEI_VERTICAL)) {
 387                         for (i = 0; i < nm->level; i++)
 388                                 fputs("  ", stdout);
 389                         fputc(' ', stdout);
 390                 }
 391
 392                 if (flags & NAMEI_MODES)
 393                         printf("%s", md);
 394                 else
 395                         printf("%c", md[0]);
 396
 397                 if (flags & NAMEI_OWNERS) {
 398                         printf(" %-*s", uwidth,
 399                                 get_id(ucache, nm->st.st_uid)->name);
 400                         printf(" %-*s", gwidth,
 401                                 get_id(gcache, nm->st.st_gid)->name);
 402                 }
 403
 404                 if (flags & NAMEI_VERTICAL)
 405                         for (i = 0; i < nm->level; i++)
 406                                 fputs("  ", stdout);
 407
 408                 if (S_ISLNK(nm->st.st_mode))
 409                         printf(" %s -> %s\n", nm->name,
 410                                         nm->abslink + nm->relstart);
 411                 else
 412                         printf(" %s\n", nm->name);
 413         }
 414         return 0;
 415 }
 416
 417 static void
 418 usage(int rc)
 419 {
 420         const char *p = program_invocation_short_name;
 421
 422         if (!*p)
 423                 p = "namei";
 424
 425         printf(_("\nUsage: %s [options] pathname [pathname ...]\n"), p);
 426         printf(_("\nOptions:\n"));
 427
 428         printf(_(
 429         " -h, --help          displays this help text\n"
 430         " -x, --mountpoints   show mount point directories with a 'D'\n"
 431         " -m, --modes         show the mode bits of each file\n"
 432         " -o, --owners        show owner and group name of each file\n"
 433         " -l, --long          use a long listing format (-m -o -v) \n"
 434         " -n, --nosymlinks    don't follow symlinks\n"
 435         " -v, --vertical      vertical align of modes and owners\n"));
 436
 437         printf(_("\nFor more information see namei(1).\n"));
 438         exit(rc);
 439 }
 440
 441 static const struct option longopts[] =
 442 {
 443         { "help",       0, 0, 'h' },
 444         { "mountpoints",0, 0, 'x' },
 445         { "modes",      0, 0, 'm' },
 446         { "owners",     0, 0, 'o' },
 447         { "long",       0, 0, 'l' },
 448         { "nolinks",    0, 0, 'n' },
 449         { "vertical",   0, 0, 'v' },
 450         { NULL,         0, 0, 0 },
 451 };
 452
 453 int
 454 main(int argc, char **argv)
 455 {
 456         extern int optind;
 457         int c;
 458         int rc = EXIT_SUCCESS;
 459
 460         setlocale(LC_ALL, "");
 461         bindtextdomain(PACKAGE, LOCALEDIR);
 462         textdomain(PACKAGE);
 463
 464         if (argc < 2)
 465                 usage(EXIT_FAILURE);
 466
 467         while ((c = getopt_long(argc, argv, "+h?lmnovx", longopts, NULL)) != -1) {
 468                 switch(c) {
 469                 case 'h':
 470                 case '?':
 471                         usage(EXIT_SUCCESS);
 472                         break;
 473                 case 'l':
 474                         flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL);
 475                         break;
 476                 case 'm':
 477                         flags |= NAMEI_MODES;
 478                         break;
 479                 case 'n':
 480                         flags |= NAMEI_NOLINKS;
 481                         break;
 482                 case 'o':
 483                         flags |= NAMEI_OWNERS;
 484                         break;
 485                 case 'x':
 486                         flags |= NAMEI_MNTS;
 487                         break;
 488                 case 'v':
 489                         flags |= NAMEI_VERTICAL;
 490                 }
 491         }
 492
 493         for(; optind < argc; optind++) {
 494                 char *path = argv[optind];
 495                 struct namei *nm = NULL;
 496                 struct stat st;
 497
 498                 if (stat(path, &st) != 0)
 499                         rc = EXIT_FAILURE;
 500
 501                 nm = add_namei(NULL, path, 0, NULL);
 502                 if (nm) {
 503                         int sml = 0;
 504                         if (!(flags & NAMEI_NOLINKS))
 505                                 sml = follow_symlinks(nm);
 506                         if (print_namei(nm, path)) {
 507                                 rc = EXIT_FAILURE;
 508                                 continue;
 509                         }
 510                         free_namei(nm);
 511                         if (sml == -1) {
 512                                 rc = EXIT_FAILURE;
 513                                 warnx(_("%s: exceeded limit of symlinks"), path);
 514                                 continue;
 515                         }
 516                 }
 517         }
 518
 519         free_idcache(ucache);
 520         free_idcache(gcache);
 521
 522         return rc;
 523 }
 524