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 #include "nls.h"
  36 #include "widechar.h"
  37
  38 #ifndef MAXSYMLINKS
  39 #define MAXSYMLINKS 256
  40 #endif
  41
  42 #ifndef PATH_MAX
  43 #define PATH_MAX 4096
  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 };
  65
  66 struct idcache {
  67         unsigned long int       id;
  68         char                    *name;
  69         struct idcache          *next;
  70 };
  71
  72 static int flags;
  73 static int uwidth;              /* maximal width of username */
  74 static int gwidth;              /* maximal width of groupname */
  75 static struct idcache *gcache;  /* groupnames */
  76 static struct idcache *ucache;  /* usernames */
  77
  78 static struct idcache *
  79 get_id(struct idcache *ic, unsigned long int id)
  80 {
  81         while(ic) {
  82                 if (ic->id == id)
  83                         return ic;
  84                 ic = ic->next;
  85         }
  86         return NULL;
  87 }
  88
  89 static void
  90 free_idcache(struct idcache *ic)
  91 {
  92         while(ic) {
  93                 struct idcache *next = ic->next;
  94                 free(ic->name);
  95                 free(ic);
  96                 ic = next;
  97         }
  98 }
  99
 100 static void
 101 add_id(struct idcache **ic, char *name, unsigned long int id, int *width)
 102 {
 103         struct idcache *nc, *x;
 104         int w = 0;
 105
 106         nc = calloc(1, sizeof(*nc));
 107         if (!nc)
 108                 goto alloc_err;
 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 = strdup(name);
 126         else if (asprintf(&nc->name, "%lu", id) == -1)
 127                 nc->name = NULL;
 128         if (!nc->name)
 129                 goto alloc_err;
 130
 131         for (x = *ic; x && x->next; x = x->next);
 132
 133         /* add 'nc' at end of the 'ic' list */
 134         if (x)
 135                 x->next = nc;
 136         else
 137                 *ic = nc;
 138         if (w <= 0)
 139                 w = strlen(nc->name);
 140         *width = *width < w ? w : *width;
 141
 142         return;
 143 alloc_err:
 144         err(EXIT_FAILURE, _("out of memory?"));
 145 }
 146
 147 static void
 148 add_uid(unsigned long int id)
 149 {
 150         struct idcache *ic = get_id(ucache, id);
 151
 152         if (!ic) {
 153                 struct passwd *pw = getpwuid((uid_t) id);
 154                 add_id(&ucache, pw ? pw->pw_name : NULL, id, &uwidth);
 155         }
 156 }
 157
 158 static void
 159 add_gid(unsigned long int id)
 160 {
 161         struct idcache *ic = get_id(gcache, id);
 162
 163         if (!ic) {
 164                 struct group *gr = getgrgid((gid_t) id);
 165                 add_id(&gcache, gr ? gr->gr_name : NULL, id, &gwidth);
 166         }
 167 }
 168
 169 static void
 170 free_namei(struct namei *nm)
 171 {
 172         while (nm) {
 173                 struct namei *next = nm->next;
 174                 free(nm->name);
 175                 free(nm->abslink);
 176                 free(nm);
 177                 nm = next;
 178         }
 179 }
 180
 181 static void
 182 readlink_to_namei(struct namei *nm, const char *path)
 183 {
 184         char sym[PATH_MAX];
 185         size_t sz;
 186
 187         sz = readlink(path, sym, sizeof(sym));
 188         if (sz < 1)
 189                 err(EXIT_FAILURE, _("failed to read symlink: %s"), path);
 190         if (*sym != '/') {
 191                 char *p = strrchr(path, '/');
 192
 193                 nm->relstart = p ? p - path : 0;
 194                 if (nm->relstart)
 195                         sz += nm->relstart + 1;
 196         }
 197         nm->abslink = malloc(sz + 1);
 198         if (!nm->abslink)
 199                 err(EXIT_FAILURE, _("out of memory?"));
 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 namei *
 213 new_namei(struct namei *parent, const char *path, const char *fname, int lev)
 214 {
 215         struct namei *nm;
 216
 217         if (!fname)
 218                 return NULL;
 219         nm = calloc(1, sizeof(*nm));
 220         if (!nm)
 221                 err(EXIT_FAILURE, _("out of memory?"));
 222         if (parent)
 223                 parent->next = nm;
 224
 225         nm->level = lev;
 226         nm->name = strdup(fname);
 227         if (!nm->name)
 228                 err(EXIT_FAILURE, _("out of memory?"));
 229         if (lstat(path, &nm->st) == -1)
 230                 err(EXIT_FAILURE, _("could not stat '%s'"), path);
 231
 232         if (S_ISLNK(nm->st.st_mode))
 233                 readlink_to_namei(nm, path);
 234         if (flags & NAMEI_OWNERS) {
 235                 add_uid(nm->st.st_uid);
 236                 add_gid(nm->st.st_gid);
 237         }
 238
 239         return nm;
 240 }
 241
 242 static struct namei *
 243 add_namei(struct namei *parent, const char *orgpath, int start, struct namei **last)
 244 {
 245         struct namei *nm = NULL, *first = NULL;
 246         char *fname, *end, *path;
 247         int level = 0;
 248
 249         if (!orgpath)
 250                 return NULL;
 251         if (parent) {
 252                 nm = parent;
 253                 level = parent->level + 1;
 254         }
 255         path = strdup(orgpath);
 256         if (!path)
 257                 err(EXIT_FAILURE, _("out of memory?"));
 258         fname = path + start;
 259
 260         /* root directory */
 261         if (*fname == '/') {
 262                 while (*fname == '/')
 263                         fname++; /* eat extra '/' */
 264                 first = nm = new_namei(nm, "/", "/", level);
 265         }
 266
 267         for (end = fname; fname && end; ) {
 268                 /* set end of filename */
 269                 if (*fname) {
 270                         end = strchr(fname, '/');
 271                         if (end)
 272                                 *end = '\0';
 273
 274                         /* create a new entry */
 275                         nm = new_namei(nm, path, fname, level);
 276                 } else
 277                         end = NULL;
 278                 if (!first)
 279                         first = nm;
 280                 /* set begin of the next filename */
 281                 if (end) {
 282                         *end++ = '/';
 283                         while (*end == '/')
 284                                 end++; /* eat extra '/' */
 285                 }
 286                 fname = end;
 287         }
 288
 289         if (last)
 290                 *last = nm;
 291         return first;
 292 }
 293
 294
 295 static int
 296 follow_symlinks(struct namei *nm)
 297 {
 298         int symcount = 0;
 299
 300         for (; nm; nm = nm->next) {
 301                 struct namei *next, *last;
 302
 303                 if (!S_ISLNK(nm->st.st_mode))
 304                         continue;
 305                 if (++symcount > MAXSYMLINKS) {
 306                         /* drop the rest of the list */
 307                         free_namei(nm->next);
 308                         nm->next = NULL;
 309                         return -1;
 310                 }
 311                 next = nm->next;
 312                 nm->next = add_namei(nm, nm->abslink, nm->relstart, &last);
 313                 if (last)
 314                         last->next = next;
 315                 else
 316                         nm->next = next;
 317         }
 318         return 0;
 319 }
 320
 321 static void
 322 strmode(mode_t mode, char *str)
 323 {
 324         if (S_ISDIR(mode))
 325                 str[0] = 'd';
 326         else if (S_ISLNK(mode))
 327                 str[0] = 'l';
 328         else if (S_ISCHR(mode))
 329                 str[0] = 'c';
 330         else if (S_ISBLK(mode))
 331                 str[0] = 'b';
 332         else if (S_ISSOCK(mode))
 333                 str[0] = 's';
 334         else if (S_ISFIFO(mode))
 335                 str[0] = 'p';
 336         else if (S_ISREG(mode))
 337                 str[0] = '-';
 338
 339         str[1] = mode & S_IRUSR ? 'r' : '-';
 340         str[2] = mode & S_IWUSR ? 'w' : '-';
 341         str[3] = (mode & S_ISUID
 342                 ? (mode & S_IXUSR ? 's' : 'S')
 343                 : (mode & S_IXUSR ? 'x' : '-'));
 344         str[4] = mode & S_IRGRP ? 'r' : '-';
 345         str[5] = mode & S_IWGRP ? 'w' : '-';
 346         str[6] = (mode & S_ISGID
 347                 ? (mode & S_IXGRP ? 's' : 'S')
 348                 : (mode & S_IXGRP ? 'x' : '-'));
 349         str[7] = mode & S_IROTH ? 'r' : '-';
 350         str[8] = mode & S_IWOTH ? 'w' : '-';
 351         str[9] = (mode & S_ISVTX
 352                 ? (mode & S_IXOTH ? 't' : 'T')
 353                 : (mode & S_IXOTH ? 'x' : '-'));
 354         str[10] = '\0';
 355 }
 356
 357 static void
 358 print_namei(struct namei *nm, char *path)
 359 {
 360         struct namei *prev = NULL;
 361         int i;
 362
 363         if (path)
 364                 printf("f: %s\n", path);
 365
 366         for (; nm; prev = nm, nm = nm->next) {
 367                 char md[11];
 368
 369                 strmode(nm->st.st_mode, md);
 370
 371                 if ((flags & NAMEI_MNTS) && prev &&
 372                     S_ISDIR(nm->st.st_mode) && S_ISDIR(prev->st.st_mode) &&
 373                     prev->st.st_dev != nm->st.st_dev)
 374                         md[0] = 'D';
 375
 376                 if (!(flags & NAMEI_VERTICAL)) {
 377                         for (i = 0; i < nm->level; i++)
 378                                 fputs("  ", stdout);
 379                         fputc(' ', stdout);
 380                 }
 381
 382                 if (flags & NAMEI_MODES)
 383                         printf("%s", md);
 384                 else
 385                         printf("%c", md[0]);
 386
 387                 if (flags & NAMEI_OWNERS) {
 388                         printf(" %-*s", uwidth,
 389                                 get_id(ucache, nm->st.st_uid)->name);
 390                         printf(" %-*s", gwidth,
 391                                 get_id(gcache, nm->st.st_gid)->name);
 392                 }
 393
 394                 if (flags & NAMEI_VERTICAL)
 395                         for (i = 0; i < nm->level; i++)
 396                                 fputs("  ", stdout);
 397
 398                 if (S_ISLNK(nm->st.st_mode))
 399                         printf(" %s -> %s\n", nm->name,
 400                                         nm->abslink + nm->relstart);
 401                 else
 402                         printf(" %s\n", nm->name);
 403         }
 404 }
 405
 406 static void
 407 usage(int rc)
 408 {
 409         const char *p = program_invocation_short_name;
 410
 411         if (!*p)
 412                 p = "namei";
 413
 414         printf(_("\nUsage: %s [options] pathname [pathname ...]\n"), p);
 415         printf(_("\nOptions:\n"));
 416
 417         printf(_(
 418         " -h, --help          displays this help text\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"));
 425
 426         printf(_("\nFor more information see namei(1).\n"));
 427         exit(rc);
 428 }
 429
 430 struct option longopts[] =
 431 {
 432         { "help",       0, 0, 'h' },
 433         { "mountpoints",0, 0, 'x' },
 434         { "modes",      0, 0, 'm' },
 435         { "owners",     0, 0, 'o' },
 436         { "long",       0, 0, 'l' },
 437         { "nolinks",    0, 0, 'n' },
 438         { "vertical",   0, 0, 'v' },
 439         { NULL,         0, 0, 0 },
 440 };
 441
 442 int
 443 main(int argc, char **argv)
 444 {
 445         extern int optind;
 446         int c;
 447
 448         setlocale(LC_ALL, "");
 449         bindtextdomain(PACKAGE, LOCALEDIR);
 450         textdomain(PACKAGE);
 451
 452         if (argc < 2)
 453                 usage(EXIT_FAILURE);
 454
 455         while ((c = getopt_long(argc, argv, "+h?lmnovx", longopts, NULL)) != -1) {
 456                 switch(c) {
 457                 case 'h':
 458                 case '?':
 459                         usage(EXIT_SUCCESS);
 460                         break;
 461                 case 'l':
 462                         flags |= (NAMEI_OWNERS | NAMEI_MODES | NAMEI_VERTICAL);
 463                         break;
 464                 case 'm':
 465                         flags |= NAMEI_MODES;
 466                         break;
 467                 case 'n':
 468                         flags |= NAMEI_NOLINKS;
 469                         break;
 470                 case 'o':
 471                         flags |= NAMEI_OWNERS;
 472                         break;
 473                 case 'x':
 474                         flags |= NAMEI_MNTS;
 475                         break;
 476                 case 'v':
 477                         flags |= NAMEI_VERTICAL;
 478                 }
 479         }
 480
 481         for(; optind < argc; optind++) {
 482                 char *path = argv[optind];
 483                 struct namei *nm = NULL;
 484                 struct stat st;
 485
 486                 if (stat(path, &st) != 0)
 487                         err(EXIT_FAILURE, _("failed to stat: %s"), path);
 488
 489                 nm = add_namei(NULL, path, 0, NULL);
 490                 if (nm) {
 491                         int sml = 0;
 492                         if (!(flags & NAMEI_NOLINKS))
 493                                 sml = follow_symlinks(nm);
 494                         print_namei(nm, path);
 495                         free_namei(nm);
 496                         if (sml == -1)
 497                                 errx(EXIT_FAILURE,
 498                                         _("%s: exceeded limit of symlinks"),
 499                                         path);
 500                 }
 501         }
 502
 503         free_idcache(ucache);
 504         free_idcache(gcache);
 505
 506         return EXIT_SUCCESS;
 507 }
 508