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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/router/libiconv-1.14/srclib/
1/* Return the canonical absolute name of a given file.
2   Copyright (C) 1996-2011 Free Software Foundation, Inc.
3   This file is part of the GNU C Library.
4
5   This program is free software: you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 3 of the License, or
8   (at your option) any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18#ifndef _LIBC
19# define _GL_USE_STDLIB_ALLOC 1
20# include <config.h>
21#endif
22
23#if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC
24
25/* Don't use __attribute__ __nonnull__ in this compilation unit.  Otherwise gcc
26   optimizes away the name == NULL test below.  */
27#define _GL_ARG_NONNULL(params)
28
29/* Specification.  */
30#include <stdlib.h>
31
32#include <alloca.h>
33#include <string.h>
34#include <unistd.h>
35#include <limits.h>
36#if HAVE_SYS_PARAM_H || defined _LIBC
37# include <sys/param.h>
38#endif
39#include <sys/stat.h>
40#include <errno.h>
41#include <stddef.h>
42
43#ifdef _LIBC
44# include <shlib-compat.h>
45#else
46# define SHLIB_COMPAT(lib, introduced, obsoleted) 0
47# define versioned_symbol(lib, local, symbol, version) extern int dummy
48# define compat_symbol(lib, local, symbol, version)
49# define weak_alias(local, symbol)
50# define __canonicalize_file_name canonicalize_file_name
51# define __realpath realpath
52# include "pathmax.h"
53# include "malloca.h"
54# if HAVE_GETCWD
55#  if IN_RELOCWRAPPER
56    /* When building the relocatable program wrapper, use the system's getcwd
57       function, not the gnulib override, otherwise we would get a link error.
58     */
59#   undef getcwd
60#  endif
61#  ifdef VMS
62    /* We want the directory in Unix syntax, not in VMS syntax.  */
63#   define __getcwd(buf, max) getcwd (buf, max, 0)
64#  else
65#   define __getcwd getcwd
66#  endif
67# else
68#  define __getcwd(buf, max) getwd (buf)
69# endif
70# define __readlink readlink
71# define __set_errno(e) errno = (e)
72# ifndef MAXSYMLINKS
73#  ifdef SYMLOOP_MAX
74#   define MAXSYMLINKS SYMLOOP_MAX
75#  else
76#   define MAXSYMLINKS 20
77#  endif
78# endif
79#endif
80
81#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
82# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
83#endif
84
85#if !FUNC_REALPATH_WORKS || defined _LIBC
86/* Return the canonical absolute name of file NAME.  A canonical name
87   does not contain any `.', `..' components nor any repeated path
88   separators ('/') or symlinks.  All path components must exist.  If
89   RESOLVED is null, the result is malloc'd; otherwise, if the
90   canonical name is PATH_MAX chars or more, returns null with `errno'
91   set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
92   returns the name in RESOLVED.  If the name cannot be resolved and
93   RESOLVED is non-NULL, it contains the path of the first component
94   that cannot be resolved.  If the path can be resolved, RESOLVED
95   holds the same value as the value returned.  */
96
97char *
98__realpath (const char *name, char *resolved)
99{
100  char *rpath, *dest, *extra_buf = NULL;
101  const char *start, *end, *rpath_limit;
102  long int path_max;
103  int num_links = 0;
104
105  if (name == NULL)
106    {
107      /* As per Single Unix Specification V2 we must return an error if
108         either parameter is a null pointer.  We extend this to allow
109         the RESOLVED parameter to be NULL in case the we are expected to
110         allocate the room for the return value.  */
111      __set_errno (EINVAL);
112      return NULL;
113    }
114
115  if (name[0] == '\0')
116    {
117      /* As per Single Unix Specification V2 we must return an error if
118         the name argument points to an empty string.  */
119      __set_errno (ENOENT);
120      return NULL;
121    }
122
123#ifdef PATH_MAX
124  path_max = PATH_MAX;
125#else
126  path_max = pathconf (name, _PC_PATH_MAX);
127  if (path_max <= 0)
128    path_max = 8192;
129#endif
130
131  if (resolved == NULL)
132    {
133      rpath = malloc (path_max);
134      if (rpath == NULL)
135        {
136          /* It's easier to set errno to ENOMEM than to rely on the
137             'malloc-posix' gnulib module.  */
138          errno = ENOMEM;
139          return NULL;
140        }
141    }
142  else
143    rpath = resolved;
144  rpath_limit = rpath + path_max;
145
146  if (name[0] != '/')
147    {
148      if (!__getcwd (rpath, path_max))
149        {
150          rpath[0] = '\0';
151          goto error;
152        }
153      dest = strchr (rpath, '\0');
154    }
155  else
156    {
157      rpath[0] = '/';
158      dest = rpath + 1;
159      if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/')
160        *dest++ = '/';
161    }
162
163  for (start = end = name; *start; start = end)
164    {
165#ifdef _LIBC
166      struct stat64 st;
167#else
168      struct stat st;
169#endif
170      int n;
171
172      /* Skip sequence of multiple path-separators.  */
173      while (*start == '/')
174        ++start;
175
176      /* Find end of path component.  */
177      for (end = start; *end && *end != '/'; ++end)
178        /* Nothing.  */;
179
180      if (end - start == 0)
181        break;
182      else if (end - start == 1 && start[0] == '.')
183        /* nothing */;
184      else if (end - start == 2 && start[0] == '.' && start[1] == '.')
185        {
186          /* Back up to previous component, ignore if at root already.  */
187          if (dest > rpath + 1)
188            while ((--dest)[-1] != '/');
189          if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
190              && *dest == '/')
191            dest++;
192        }
193      else
194        {
195          size_t new_size;
196
197          if (dest[-1] != '/')
198            *dest++ = '/';
199
200          if (dest + (end - start) >= rpath_limit)
201            {
202              ptrdiff_t dest_offset = dest - rpath;
203              char *new_rpath;
204
205              if (resolved)
206                {
207                  __set_errno (ENAMETOOLONG);
208                  if (dest > rpath + 1)
209                    dest--;
210                  *dest = '\0';
211                  goto error;
212                }
213              new_size = rpath_limit - rpath;
214              if (end - start + 1 > path_max)
215                new_size += end - start + 1;
216              else
217                new_size += path_max;
218              new_rpath = (char *) realloc (rpath, new_size);
219              if (new_rpath == NULL)
220                {
221                  /* It's easier to set errno to ENOMEM than to rely on the
222                     'realloc-posix' gnulib module.  */
223                  errno = ENOMEM;
224                  goto error;
225                }
226              rpath = new_rpath;
227              rpath_limit = rpath + new_size;
228
229              dest = rpath + dest_offset;
230            }
231
232#ifdef _LIBC
233          dest = __mempcpy (dest, start, end - start);
234#else
235          memcpy (dest, start, end - start);
236          dest += end - start;
237#endif
238          *dest = '\0';
239
240#ifdef _LIBC
241          if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
242#else
243          if (lstat (rpath, &st) < 0)
244#endif
245            goto error;
246
247          if (S_ISLNK (st.st_mode))
248            {
249              char *buf;
250              size_t len;
251
252              if (++num_links > MAXSYMLINKS)
253                {
254                  __set_errno (ELOOP);
255                  goto error;
256                }
257
258              buf = malloca (path_max);
259              if (!buf)
260                {
261                  errno = ENOMEM;
262                  goto error;
263                }
264
265              n = __readlink (rpath, buf, path_max - 1);
266              if (n < 0)
267                {
268                  int saved_errno = errno;
269                  freea (buf);
270                  errno = saved_errno;
271                  goto error;
272                }
273              buf[n] = '\0';
274
275              if (!extra_buf)
276                {
277                  extra_buf = malloca (path_max);
278                  if (!extra_buf)
279                    {
280                      freea (buf);
281                      errno = ENOMEM;
282                      goto error;
283                    }
284                }
285
286              len = strlen (end);
287              if ((long int) (n + len) >= path_max)
288                {
289                  freea (buf);
290                  __set_errno (ENAMETOOLONG);
291                  goto error;
292                }
293
294              /* Careful here, end may be a pointer into extra_buf... */
295              memmove (&extra_buf[n], end, len + 1);
296              name = end = memcpy (extra_buf, buf, n);
297
298              if (buf[0] == '/')
299                {
300                  dest = rpath + 1;     /* It's an absolute symlink */
301                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && buf[1] == '/')
302                    *dest++ = '/';
303                }
304              else
305                {
306                  /* Back up to previous component, ignore if at root
307                     already: */
308                  if (dest > rpath + 1)
309                    while ((--dest)[-1] != '/');
310                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
311                      && *dest == '/')
312                    dest++;
313                }
314            }
315          else if (!S_ISDIR (st.st_mode) && *end != '\0')
316            {
317              __set_errno (ENOTDIR);
318              goto error;
319            }
320        }
321    }
322  if (dest > rpath + 1 && dest[-1] == '/')
323    --dest;
324  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && *dest == '/')
325    dest++;
326  *dest = '\0';
327
328  if (extra_buf)
329    freea (extra_buf);
330
331  return rpath;
332
333error:
334  {
335    int saved_errno = errno;
336    if (extra_buf)
337      freea (extra_buf);
338    if (resolved == NULL)
339      free (rpath);
340    errno = saved_errno;
341  }
342  return NULL;
343}
344versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
345#endif /* !FUNC_REALPATH_WORKS || defined _LIBC */
346
347
348#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
349char *
350attribute_compat_text_section
351__old_realpath (const char *name, char *resolved)
352{
353  if (resolved == NULL)
354    {
355      __set_errno (EINVAL);
356      return NULL;
357    }
358
359  return __realpath (name, resolved);
360}
361compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
362#endif
363
364
365char *
366__canonicalize_file_name (const char *name)
367{
368  return __realpath (name, NULL);
369}
370weak_alias (__canonicalize_file_name, canonicalize_file_name)
371
372#else
373
374/* This declaration is solely to ensure that after preprocessing
375   this file is never empty.  */
376typedef int dummy;
377
378#endif
379