[bpt/guile.git] / lib / canonicalize-lgpl.c

/* Return the canonical absolute name of a given file.
   Copyright (C) 1996-2009 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef _LIBC
# include <config.h>
#endif

#if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC

/* Specification.  */
#include <stdlib.h>

#include <alloca.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#if HAVE_SYS_PARAM_H || defined _LIBC
# include <sys/param.h>
#endif
#include <sys/stat.h>
#include <errno.h>
#include <stddef.h>

#ifdef _LIBC
# include <shlib-compat.h>
#else
# define SHLIB_COMPAT(lib, introduced, obsoleted) 0
# define versioned_symbol(lib, local, symbol, version)
# define compat_symbol(lib, local, symbol, version)
# define weak_alias(local, symbol)
# define __canonicalize_file_name canonicalize_file_name
# define __realpath realpath
# include "pathmax.h"
# include "malloca.h"
# if HAVE_GETCWD
#  ifdef VMS
    /* We want the directory in Unix syntax, not in VMS syntax.  */
#   define __getcwd(buf, max) getcwd (buf, max, 0)
#  else
#   define __getcwd getcwd
#  endif
# else
#  define __getcwd(buf, max) getwd (buf)
# endif
# define __readlink readlink
# define __set_errno(e) errno = (e)
# ifndef MAXSYMLINKS
#  ifdef SYMLOOP_MAX
#   define MAXSYMLINKS SYMLOOP_MAX
#  else
#   define MAXSYMLINKS 20
#  endif
# endif
#endif

#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
#endif

#if !FUNC_REALPATH_WORKS || defined _LIBC
/* Return the canonical absolute name of file NAME.  A canonical name
   does not contain any `.', `..' components nor any repeated path
   separators ('/') or symlinks.  All path components must exist.  If
   RESOLVED is null, the result is malloc'd; otherwise, if the
   canonical name is PATH_MAX chars or more, returns null with `errno'
   set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
   returns the name in RESOLVED.  If the name cannot be resolved and
   RESOLVED is non-NULL, it contains the path of the first component
   that cannot be resolved.  If the path can be resolved, RESOLVED
   holds the same value as the value returned.  */

char *
__realpath (const char *name, char *resolved)
{
  char *rpath, *dest, *extra_buf = NULL;
  const char *start, *end, *rpath_limit;
  long int path_max;
  int num_links = 0;

  if (name == NULL)
    {
      /* As per Single Unix Specification V2 we must return an error if
	 either parameter is a null pointer.  We extend this to allow
	 the RESOLVED parameter to be NULL in case the we are expected to
	 allocate the room for the return value.  */
      __set_errno (EINVAL);
      return NULL;
    }

  if (name[0] == '\0')
    {
      /* As per Single Unix Specification V2 we must return an error if
	 the name argument points to an empty string.  */
      __set_errno (ENOENT);
      return NULL;
    }

#ifdef PATH_MAX
  path_max = PATH_MAX;
#else
  path_max = pathconf (name, _PC_PATH_MAX);
  if (path_max <= 0)
    path_max = 1024;
#endif

  if (resolved == NULL)
    {
      rpath = malloc (path_max);
      if (rpath == NULL)
	{
	  /* It's easier to set errno to ENOMEM than to rely on the
	     'malloc-posix' gnulib module.  */
	  errno = ENOMEM;
	  return NULL;
	}
    }
  else
    rpath = resolved;
  rpath_limit = rpath + path_max;

  if (name[0] != '/')
    {
      if (!__getcwd (rpath, path_max))
	{
	  rpath[0] = '\0';
	  goto error;
	}
      dest = strchr (rpath, '\0');
    }
  else
    {
      rpath[0] = '/';
      dest = rpath + 1;
      if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/')
	*dest++ = '/';
    }

  for (start = end = name; *start; start = end)
    {
#ifdef _LIBC
      struct stat64 st;
#else
      struct stat st;
#endif
      int n;

      /* Skip sequence of multiple path-separators.  */
      while (*start == '/')
	++start;

      /* Find end of path component.  */
      for (end = start; *end && *end != '/'; ++end)
	/* Nothing.  */;

      if (end - start == 0)
	break;
      else if (end - start == 1 && start[0] == '.')
	/* nothing */;
      else if (end - start == 2 && start[0] == '.' && start[1] == '.')
	{
	  /* Back up to previous component, ignore if at root already.  */
	  if (dest > rpath + 1)
	    while ((--dest)[-1] != '/');
	  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
	      && *dest == '/')
	    dest++;
	}
      else
	{
	  size_t new_size;

	  if (dest[-1] != '/')
	    *dest++ = '/';

	  if (dest + (end - start) >= rpath_limit)
	    {
	      ptrdiff_t dest_offset = dest - rpath;
	      char *new_rpath;

	      if (resolved)
		{
		  __set_errno (ENAMETOOLONG);
		  if (dest > rpath + 1)
		    dest--;
		  *dest = '\0';
		  goto error;
		}
	      new_size = rpath_limit - rpath;
	      if (end - start + 1 > path_max)
		new_size += end - start + 1;
	      else
		new_size += path_max;
	      new_rpath = (char *) realloc (rpath, new_size);
	      if (new_rpath == NULL)
		{
		  /* It's easier to set errno to ENOMEM than to rely on the
		     'realloc-posix' gnulib module.  */
		  errno = ENOMEM;
		  goto error;
		}
	      rpath = new_rpath;
	      rpath_limit = rpath + new_size;

	      dest = rpath + dest_offset;
	    }

#ifdef _LIBC
	  dest = __mempcpy (dest, start, end - start);
#else
	  memcpy (dest, start, end - start);
	  dest += end - start;
#endif
	  *dest = '\0';

#ifdef _LIBC
	  if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
#else
	  if (lstat (rpath, &st) < 0)
#endif
	    goto error;

	  if (S_ISLNK (st.st_mode))
	    {
	      char *buf;
	      size_t len;

	      if (++num_links > MAXSYMLINKS)
		{
		  __set_errno (ELOOP);
		  goto error;
		}

	      buf = malloca (path_max);
	      if (!buf)
		{
		  errno = ENOMEM;
		  goto error;
		}

	      n = __readlink (rpath, buf, path_max - 1);
	      if (n < 0)
		{
		  int saved_errno = errno;
		  freea (buf);
		  errno = saved_errno;
		  goto error;
		}
	      buf[n] = '\0';

	      if (!extra_buf)
		{
		  extra_buf = malloca (path_max);
		  if (!extra_buf)
		    {
		      freea (buf);
		      errno = ENOMEM;
		      goto error;
		    }
		}

	      len = strlen (end);
	      if ((long int) (n + len) >= path_max)
		{
		  freea (buf);
		  __set_errno (ENAMETOOLONG);
		  goto error;
		}

	      /* Careful here, end may be a pointer into extra_buf... */
	      memmove (&extra_buf[n], end, len + 1);
	      name = end = memcpy (extra_buf, buf, n);

	      if (buf[0] == '/')
		{
		  dest = rpath + 1;	/* It's an absolute symlink */
		  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && buf[1] == '/')
		    *dest++ = '/';
		}
	      else
		{
		  /* Back up to previous component, ignore if at root
		     already: */
		  if (dest > rpath + 1)
		    while ((--dest)[-1] != '/');
		  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
		      && *dest == '/')
		    dest++;
		}
	    }
	  else if (!S_ISDIR (st.st_mode) && *end != '\0')
	    {
	      __set_errno (ENOTDIR);
	      goto error;
	    }
	}
    }
  if (dest > rpath + 1 && dest[-1] == '/')
    --dest;
  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && *dest == '/')
    dest++;
  *dest = '\0';

  if (extra_buf)
    freea (extra_buf);

  return rpath;

error:
  {
    int saved_errno = errno;
    if (extra_buf)
      freea (extra_buf);
    if (resolved == NULL)
      free (rpath);
    errno = saved_errno;
  }
  return NULL;
}
versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
#endif /* !FUNC_REALPATH_WORKS || defined _LIBC */


#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
char *
attribute_compat_text_section
__old_realpath (const char *name, char *resolved)
{
  if (resolved == NULL)
    {
      __set_errno (EINVAL);
      return NULL;
    }

  return __realpath (name, resolved);
}
compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
#endif


char *
__canonicalize_file_name (const char *name)
{
  return __realpath (name, NULL);
}
weak_alias (__canonicalize_file_name, canonicalize_file_name)

#else

/* This declaration is solely to ensure that after preprocessing
   this file is never empty.  */
typedef int dummy;

#endif
Commit	Line	Data
ffca4c22	1	/* Return the canonical absolute name of a given file.
8912421c	2	Copyright (C) 1996-2009 Free Software Foundation, Inc.
ffca4c22 AW	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 Lesser 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 Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public License
	16	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	17
8912421c LC	18	#ifndef _LIBC
	19	# include <config.h>
	20	#endif
ffca4c22	21
8912421c	22	#if !HAVE_CANONICALIZE_FILE_NAME \|\| !FUNC_REALPATH_WORKS \|\| defined _LIBC
ffca4c22 AW	23
ffca4c22 AW	24	/* Specification. */
ffca4c22	25	#include <stdlib.h>
ffca4c22	26
8912421c LC	27	#include <alloca.h>
	28	#include <string.h>
	29	#include <unistd.h>
ffca4c22	30	#include <limits.h>
ffca4c22 AW	31	#if HAVE_SYS_PARAM_H \|\| defined _LIBC
	32	# include <sys/param.h>
	33	#endif
ffca4c22	34	#include <sys/stat.h>
ffca4c22	35	#include <errno.h>
8912421c	36	#include <stddef.h>
ffca4c22 AW	37
	38	#ifdef _LIBC
	39	# include <shlib-compat.h>
	40	#else
	41	# define SHLIB_COMPAT(lib, introduced, obsoleted) 0
	42	# define versioned_symbol(lib, local, symbol, version)
	43	# define compat_symbol(lib, local, symbol, version)
	44	# define weak_alias(local, symbol)
	45	# define __canonicalize_file_name canonicalize_file_name
8912421c	46	# define __realpath realpath
ffca4c22 AW	47	# include "pathmax.h"
	48	# include "malloca.h"
	49	# if HAVE_GETCWD
	50	# ifdef VMS
	51	/* We want the directory in Unix syntax, not in VMS syntax. */
	52	# define __getcwd(buf, max) getcwd (buf, max, 0)
	53	# else
	54	# define __getcwd getcwd
	55	# endif
	56	# else
	57	# define __getcwd(buf, max) getwd (buf)
	58	# endif
	59	# define __readlink readlink
8912421c LC	60	# define __set_errno(e) errno = (e)
	61	# ifndef MAXSYMLINKS
	62	# ifdef SYMLOOP_MAX
	63	# define MAXSYMLINKS SYMLOOP_MAX
	64	# else
	65	# define MAXSYMLINKS 20
	66	# endif
ffca4c22 AW	67	# endif
	68	#endif
	69
8912421c LC	70	#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
	71	# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
	72	#endif
	73
	74	#if !FUNC_REALPATH_WORKS \|\| defined _LIBC
ffca4c22 AW	75	/* Return the canonical absolute name of file NAME. A canonical name
	76	does not contain any `.', `..' components nor any repeated path
	77	separators ('/') or symlinks. All path components must exist. If
	78	RESOLVED is null, the result is malloc'd; otherwise, if the
	79	canonical name is PATH_MAX chars or more, returns null with `errno'
	80	set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars,
	81	returns the name in RESOLVED. If the name cannot be resolved and
	82	RESOLVED is non-NULL, it contains the path of the first component
	83	that cannot be resolved. If the path can be resolved, RESOLVED
	84	holds the same value as the value returned. */
	85
	86	char *
	87	__realpath (const char name, char resolved)
	88	{
	89	char rpath, dest, *extra_buf = NULL;
	90	const char start, end, *rpath_limit;
	91	long int path_max;
ffca4c22	92	int num_links = 0;
ffca4c22 AW	93
	94	if (name == NULL)
	95	{
	96	/* As per Single Unix Specification V2 we must return an error if
	97	either parameter is a null pointer. We extend this to allow
	98	the RESOLVED parameter to be NULL in case the we are expected to
	99	allocate the room for the return value. */
	100	__set_errno (EINVAL);
	101	return NULL;
	102	}
	103
	104	if (name[0] == '\0')
	105	{
	106	/* As per Single Unix Specification V2 we must return an error if
	107	the name argument points to an empty string. */
	108	__set_errno (ENOENT);
	109	return NULL;
	110	}
	111
	112	#ifdef PATH_MAX
	113	path_max = PATH_MAX;
	114	#else
	115	path_max = pathconf (name, _PC_PATH_MAX);
	116	if (path_max <= 0)
	117	path_max = 1024;
	118	#endif
	119
	120	if (resolved == NULL)
	121	{
	122	rpath = malloc (path_max);
	123	if (rpath == NULL)
	124	{
	125	/* It's easier to set errno to ENOMEM than to rely on the
	126	'malloc-posix' gnulib module. */
	127	errno = ENOMEM;
	128	return NULL;
	129	}
	130	}
	131	else
	132	rpath = resolved;
	133	rpath_limit = rpath + path_max;
	134
	135	if (name[0] != '/')
	136	{
	137	if (!__getcwd (rpath, path_max))
	138	{
	139	rpath[0] = '\0';
	140	goto error;
	141	}
	142	dest = strchr (rpath, '\0');
	143	}
	144	else
	145	{
	146	rpath[0] = '/';
	147	dest = rpath + 1;
8912421c LC	148	if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/')
8912421c LC	149	*dest++ = '/';
ffca4c22 AW	150	}
	151
	152	for (start = end = name; *start; start = end)
	153	{
	154	#ifdef _LIBC
	155	struct stat64 st;
	156	#else
	157	struct stat st;
	158	#endif
8912421c	159	int n;
ffca4c22 AW	160
	161	/* Skip sequence of multiple path-separators. */
	162	while (*start == '/')
	163	++start;
	164
	165	/* Find end of path component. */
	166	for (end = start; end && end != '/'; ++end)
	167	/* Nothing. */;
	168
	169	if (end - start == 0)
	170	break;
	171	else if (end - start == 1 && start[0] == '.')
	172	/* nothing */;
	173	else if (end - start == 2 && start[0] == '.' && start[1] == '.')
	174	{
	175	/* Back up to previous component, ignore if at root already. */
	176	if (dest > rpath + 1)
	177	while ((--dest)[-1] != '/');
8912421c LC	178	if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
	179	&& *dest == '/')
	180	dest++;
ffca4c22 AW	181	}
	182	else
	183	{
	184	size_t new_size;
	185
	186	if (dest[-1] != '/')
	187	*dest++ = '/';
	188
	189	if (dest + (end - start) >= rpath_limit)
	190	{
	191	ptrdiff_t dest_offset = dest - rpath;
	192	char *new_rpath;
	193
	194	if (resolved)
	195	{
	196	__set_errno (ENAMETOOLONG);
	197	if (dest > rpath + 1)
	198	dest--;
	199	*dest = '\0';
	200	goto error;
	201	}
	202	new_size = rpath_limit - rpath;
	203	if (end - start + 1 > path_max)
	204	new_size += end - start + 1;
	205	else
	206	new_size += path_max;
	207	new_rpath = (char *) realloc (rpath, new_size);
	208	if (new_rpath == NULL)
	209	{
	210	/* It's easier to set errno to ENOMEM than to rely on the
	211	'realloc-posix' gnulib module. */
	212	errno = ENOMEM;
	213	goto error;
	214	}
	215	rpath = new_rpath;
	216	rpath_limit = rpath + new_size;
	217
	218	dest = rpath + dest_offset;
	219	}
	220
	221	#ifdef _LIBC
	222	dest = __mempcpy (dest, start, end - start);
	223	#else
	224	memcpy (dest, start, end - start);
	225	dest += end - start;
	226	#endif
	227	*dest = '\0';
	228
	229	#ifdef _LIBC
	230	if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
	231	#else
	232	if (lstat (rpath, &st) < 0)
	233	#endif
	234	goto error;
	235
ffca4c22 AW	236	if (S_ISLNK (st.st_mode))
	237	{
	238	char *buf;
	239	size_t len;
ffca4c22 AW	240
	241	if (++num_links > MAXSYMLINKS)
	242	{
	243	__set_errno (ELOOP);
	244	goto error;
	245	}
	246
	247	buf = malloca (path_max);
	248	if (!buf)
	249	{
	250	errno = ENOMEM;
	251	goto error;
	252	}
	253
	254	n = __readlink (rpath, buf, path_max - 1);
	255	if (n < 0)
	256	{
	257	int saved_errno = errno;
	258	freea (buf);
	259	errno = saved_errno;
	260	goto error;
	261	}
	262	buf[n] = '\0';
	263
	264	if (!extra_buf)
	265	{
	266	extra_buf = malloca (path_max);
	267	if (!extra_buf)
	268	{
	269	freea (buf);
	270	errno = ENOMEM;
	271	goto error;
	272	}
	273	}
	274
	275	len = strlen (end);
	276	if ((long int) (n + len) >= path_max)
	277	{
	278	freea (buf);
	279	__set_errno (ENAMETOOLONG);
	280	goto error;
	281	}
	282
	283	/* Careful here, end may be a pointer into extra_buf... */
	284	memmove (&extra_buf[n], end, len + 1);
	285	name = end = memcpy (extra_buf, buf, n);
	286
	287	if (buf[0] == '/')
8912421c LC	288	{
	289	dest = rpath + 1; /* It's an absolute symlink */
	290	if (DOUBLE_SLASH_IS_DISTINCT_ROOT && buf[1] == '/')
	291	*dest++ = '/';
	292	}
ffca4c22	293	else
8912421c LC	294	{
	295	/* Back up to previous component, ignore if at root
	296	already: */
	297	if (dest > rpath + 1)
	298	while ((--dest)[-1] != '/');
	299	if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
	300	&& *dest == '/')
	301	dest++;
	302	}
	303	}
	304	else if (!S_ISDIR (st.st_mode) && *end != '\0')
	305	{
	306	__set_errno (ENOTDIR);
	307	goto error;
ffca4c22	308	}
ffca4c22 AW	309	}
	310	}
	311	if (dest > rpath + 1 && dest[-1] == '/')
	312	--dest;
8912421c LC	313	if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && *dest == '/')
8912421c LC	314	dest++;
ffca4c22 AW	315	*dest = '\0';
	316
	317	if (extra_buf)
	318	freea (extra_buf);
	319
8912421c	320	return rpath;
ffca4c22 AW	321
	322	error:
	323	{
	324	int saved_errno = errno;
	325	if (extra_buf)
	326	freea (extra_buf);
8912421c	327	if (resolved == NULL)
ffca4c22 AW	328	free (rpath);
	329	errno = saved_errno;
	330	}
	331	return NULL;
	332	}
ffca4c22	333	versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
8912421c	334	#endif /* !FUNC_REALPATH_WORKS \|\| defined _LIBC */
ffca4c22 AW	335
	336
	337	#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
	338	char *
8912421c	339	attribute_compat_text_section
ffca4c22 AW	340	__old_realpath (const char name, char resolved)
	341	{
	342	if (resolved == NULL)
	343	{
	344	__set_errno (EINVAL);
	345	return NULL;
	346	}
	347
	348	return __realpath (name, resolved);
	349	}
	350	compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0);
	351	#endif
	352
	353
	354	char *
	355	__canonicalize_file_name (const char *name)
	356	{
	357	return __realpath (name, NULL);
	358	}
	359	weak_alias (__canonicalize_file_name, canonicalize_file_name)
	360
	361	#else
	362
	363	/* This declaration is solely to ensure that after preprocessing
	364	this file is never empty. */
	365	typedef int dummy;
	366
	367	#endif