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* eina: fix possible race condition between opendir/readdir_r/pathconf. 

See http://womble.decadent.org.uk/readdir_r-advisory.html .


SVN revision: 54117
This commit is contained in:
Cedric BAIL 2010-11-03 10:19:55 +00:00
parent be6cf01bb8
commit c40d642b02
2 changed files with 44 additions and 4 deletions
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1
legacy/eina/configure.ac
View File

@ -530,6 +530,7 @@ if test "x${dirfd}" = "xyes"; then
fi
AC_CHECK_FUNCS([openat], [AC_DEFINE(HAVE_OPENAT)], [])
AC_CHECK_FUNCS([statat], [AC_DEFINE(HAVE_STATAT)], [])
AC_CHECK_FUNCS([fpathconf], [AC_DEFINE(HAVE_FPATHCONF)], [])
### Modules

47
legacy/eina/src/lib/eina_file.c
View File

@ -81,6 +81,45 @@ struct _Eina_File_Iterator
char dir[1];
};
/*
* This complex piece of code is needed due to possible race condition.
* The code and description of the issue can be found at :
* http://womble.decadent.org.uk/readdir_r-advisory.html
*/
static size_t
_eina_dirent_buffer_size(DIR * dirp)
{
long name_max;
size_t name_end;
#if defined(HAVE_FPATHCONF) && defined(HAVE_DIRFD) && defined(_PC_NAME_MAX)
name_max = fpathconf(dirfd(dirp), _PC_NAME_MAX);
if (name_max == -1)
{
# if defined(NAME_MAX)
name_max = (NAME_MAX > 255) ? NAME_MAX : 255;
# else
return PATH_MAX;
# endif
}
#else
# if defined(NAME_MAX)
name_max = (NAME_MAX > 255) ? NAME_MAX : 255;
# else
# ifdef _PC_NAME_MAX
# warning "buffer size for readdir_r cannot be determined safely, best effort, but racy"
name_max = pathconf(dirp, _PC_NAME_MAX);
# else
# error "buffer size for readdir_r cannot be determined safely"
# endif
# endif
#endif
name_end = (size_t) offsetof(struct dirent, d_name) + name_max + 1;
return (name_end > sizeof (struct dirent) ? name_end : sizeof (struct dirent));
}
static Eina_Bool
_eina_file_ls_iterator_next(Eina_File_Iterator *it, void **data)
{
@ -88,7 +127,7 @@ _eina_file_ls_iterator_next(Eina_File_Iterator *it, void **data)
char *name;
size_t length;
dp = alloca(offsetof(struct dirent, d_name) + pathconf(it->dir, _PC_NAME_MAX) + 1);
dp = alloca(_eina_dirent_buffer_size(it->dirp));
do
{
@ -150,7 +189,7 @@ _eina_file_direct_ls_iterator_next(Eina_File_Direct_Iterator *it, void **data)
struct dirent *dp;
size_t length;
dp = alloca(offsetof(struct dirent, d_name) + pathconf(it->dir, _PC_NAME_MAX) + 1);
dp = alloca(_eina_dirent_buffer_size(it->dir));
do
{
@ -336,8 +375,8 @@ eina_file_dir_list(const char *dir,
return EINA_FALSE;
dlength = strlen(dir);
de = alloca(offsetof(struct dirent, d_name) + pathconf(dir, _PC_NAME_MAX) + 1);
de = alloca(_eina_dirent_buffer_size(dir));
while ((!readdir_r(d, de, &de) && de))
{
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))