static prop_area* map_prop_area(const char* filename, bool is_legacy) {
int fd = open(filename, O_CLOEXEC | O_NOFOLLOW | O_RDONLY);
bool close_fd = true;
if (fd == -1 && errno == ENOENT && is_legacy) {
/*
* For backwards compatibility, if the file doesn't
* exist, we use the environment to get the file descriptor.
* For security reasons, we only use this backup if the kernel
* returns ENOENT. We don't want to use the backup if the kernel
* returns other errors such as ENOMEM or ENFILE, since it
* might be possible for an external program to trigger this
* condition.
* Only do this for the legacy prop file, secured prop files
* do not have a backup
*/
fd = get_fd_from_env();
close_fd = false;
}
if (fd < 0) {
return nullptr;
}
prop_area* map_result = map_fd_ro(fd);
if (close_fd) {
close(fd);
}
return map_result;
}
static int map_prop_area()
{
int fd = open(property_filename, O_CLOEXEC | O_NOFOLLOW | O_RDONLY);
bool close_fd = true;
if (fd == -1 && errno == ENOENT) {
/*
* For backwards compatibility, if the file doesn't
* exist, we use the environment to get the file descriptor.
* For security reasons, we only use this backup if the kernel
* returns ENOENT. We don't want to use the backup if the kernel
* returns other errors such as ENOMEM or ENFILE, since it
* might be possible for an external program to trigger this
* condition.
*/
fd = get_fd_from_env();
close_fd = false;
}
if (fd < 0) {
return -1;
}
const int map_result = map_fd_ro(fd);
if (close_fd) {
close(fd);
}
return map_result;
}
static prop_area* map_prop_area(const char* filename
#if MB_ENABLE_COMPAT_PROPERTIES
, bool is_legacy
#endif
) {
int fd = open(filename, O_CLOEXEC | O_NOFOLLOW |
#if MB_ALLOW_DIRECT_CLIENT_WRITES
O_RDWR
#else
O_RDONLY
#endif
);
#if MB_ENABLE_COMPAT_PROPERTIES
bool close_fd = true;
if (fd == -1 && errno == ENOENT && is_legacy) {
/*
* For backwards compatibility, if the file doesn't
* exist, we use the environment to get the file descriptor.
* For security reasons, we only use this backup if the kernel
* returns ENOENT. We don't want to use the backup if the kernel
* returns other errors such as ENOMEM or ENFILE, since it
* might be possible for an external program to trigger this
* condition.
* Only do this for the legacy prop file, secured prop files
* do not have a backup
*/
fd = get_fd_from_env();
close_fd = false;
}
#endif
if (fd == -1) return nullptr;
prop_area* map_result = map_fd_ro(fd);
#if MB_ENABLE_COMPAT_PROPERTIES
if (close_fd) {
#endif
close(fd);
#if MB_ENABLE_COMPAT_PROPERTIES
}
#endif
return map_result;
}
