canonicalize-lgpl.c [plain text]
#include <config.h>
#undef realpath
#if !HAVE_CANONICALIZE_FILE_NAME || defined _LIBC
#include <alloca.h>
#include "canonicalize.h"
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#if HAVE_UNISTD_H || defined _LIBC
# include <unistd.h>
#endif
#include <limits.h>
#if HAVE_SYS_PARAM_H || defined _LIBC
# include <sys/param.h>
#endif
#ifndef MAXSYMLINKS
# define MAXSYMLINKS 20
#endif
#include <sys/stat.h>
#include <errno.h>
#ifndef _LIBC
# define __set_errno(e) errno = (e)
# ifndef ENAMETOOLONG
# define ENAMETOOLONG EINVAL
# endif
#endif
#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 rpl_realpath
# include "pathmax.h"
# include "allocsa.h"
# if HAVE_GETCWD
# ifdef VMS
# define __getcwd(buf, max) getcwd (buf, max, 0)
# else
# define __getcwd getcwd
# endif
# else
# define __getcwd(buf, max) getwd (buf)
# endif
# define __readlink readlink
# if !defined S_ISNLK && !HAVE_READLINK
# define lstat stat
# endif
#endif
char *
__realpath (const char *name, char *resolved)
{
char *rpath, *dest, *extra_buf = NULL;
const char *start, *end, *rpath_limit;
long int path_max;
#if HAVE_READLINK
int num_links = 0;
#endif
if (name == NULL)
{
__set_errno (EINVAL);
return NULL;
}
if (name[0] == '\0')
{
__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)
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;
}
for (start = end = name; *start; start = end)
{
#ifdef _LIBC
struct stat64 st;
#else
struct stat st;
#endif
while (*start == '/')
++start;
for (end = start; *end && *end != '/'; ++end)
;
if (end - start == 0)
break;
else if (end - start == 1 && start[0] == '.')
;
else if (end - start == 2 && start[0] == '.' && start[1] == '.')
{
if (dest > rpath + 1)
while ((--dest)[-1] != '/');
}
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)
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 HAVE_READLINK
if (S_ISLNK (st.st_mode))
{
char *buf;
size_t len;
int n;
if (++num_links > MAXSYMLINKS)
{
__set_errno (ELOOP);
goto error;
}
buf = allocsa (path_max);
if (!buf)
{
errno = ENOMEM;
goto error;
}
n = __readlink (rpath, buf, path_max);
if (n < 0)
{
int saved_errno = errno;
freesa (buf);
errno = saved_errno;
goto error;
}
buf[n] = '\0';
if (!extra_buf)
{
extra_buf = allocsa (path_max);
if (!extra_buf)
{
freesa (buf);
errno = ENOMEM;
goto error;
}
}
len = strlen (end);
if ((long int) (n + len) >= path_max)
{
freesa (buf);
__set_errno (ENAMETOOLONG);
goto error;
}
memmove (&extra_buf[n], end, len + 1);
name = end = memcpy (extra_buf, buf, n);
if (buf[0] == '/')
dest = rpath + 1;
else
if (dest > rpath + 1)
while ((--dest)[-1] != '/');
}
#endif
}
}
if (dest > rpath + 1 && dest[-1] == '/')
--dest;
*dest = '\0';
if (extra_buf)
freesa (extra_buf);
return resolved ? memcpy (resolved, rpath, dest - rpath + 1) : rpath;
error:
{
int saved_errno = errno;
if (extra_buf)
freesa (extra_buf);
if (resolved)
strcpy (resolved, rpath);
else
free (rpath);
errno = saved_errno;
}
return NULL;
}
#ifdef _LIBC
versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
#endif
#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3)
char *
__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
typedef int dummy;
#endif