struct security_descriptor *get_file_sd( struct object *obj, struct fd *fd, mode_t *mode,
uid_t *uid )
{
int unix_fd = get_unix_fd( fd );
struct stat st;
struct security_descriptor *sd;
const SID *user, *group;
if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
return obj->sd;
/* mode and uid the same? if so, no need to re-generate security descriptor */
if (obj->sd && (st.st_mode & (S_IRWXU|S_IRWXO)) == (*mode & (S_IRWXU|S_IRWXO)) &&
(st.st_uid == *uid))
return obj->sd;
user = security_unix_uid_to_sid( st.st_uid );
group = token_get_primary_group( current->process->token );
sd = get_xattr_sd( unix_fd );
if (!sd) sd = get_xattr_acls( unix_fd, user, group );
if (sd) convert_generic_sd( sd );
if (!sd) sd = mode_to_sd( st.st_mode, user, group );
if (!sd) return obj->sd;
*mode = st.st_mode;
*uid = st.st_uid;
free( obj->sd );
obj->sd = sd;
return sd;
}
static struct security_descriptor *file_get_sd( struct object *obj )
{
struct file *file = (struct file *)obj;
struct stat st;
int unix_fd;
struct security_descriptor *sd;
assert( obj->ops == &file_ops );
unix_fd = get_file_unix_fd( file );
if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
return obj->sd;
/* mode and uid the same? if so, no need to re-generate security descriptor */
if (obj->sd && (st.st_mode & (S_IRWXU|S_IRWXO)) == (file->mode & (S_IRWXU|S_IRWXO)) &&
(st.st_uid == file->uid))
return obj->sd;
sd = mode_to_sd( st.st_mode,
security_unix_uid_to_sid( st.st_uid ),
token_get_primary_group( current->process->token ));
if (!sd) return obj->sd;
file->mode = st.st_mode;
file->uid = st.st_uid;
free( obj->sd );
obj->sd = sd;
return sd;
}
static struct security_descriptor *file_get_parent_sd( struct fd *root, const char *child_name,
int child_len, int is_dir )
{
struct security_descriptor *parent_sd, *sd = NULL;
mode_t parent_mode = 0555;
char *p, *parent_name;
struct fd *parent_fd;
struct stat st;
int unix_fd;
if (!(parent_name = mem_alloc( child_len + 1 ))) return NULL;
memcpy( parent_name, child_name, child_len );
parent_name[child_len] = 0;
/* skip trailing slashes */
p = parent_name + strlen( parent_name ) - 1;
while (p > parent_name && *p == '/') p--;
/* remove last path component */
if (p == parent_name && *p == '/')
{
free(parent_name);
return NULL;
}
while (p > parent_name && *p != '/') p--;
while (p > parent_name && *p == '/') p--;
p[1] = 0;
parent_fd = open_fd( root, parent_name, O_NONBLOCK | O_LARGEFILE, &parent_mode,
READ_CONTROL|ACCESS_SYSTEM_SECURITY,
FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
FILE_OPEN_FOR_BACKUP_INTENT );
free( parent_name );
if (parent_fd)
{
unix_fd = get_unix_fd( parent_fd );
if (unix_fd != -1)
{
parent_sd = get_xattr_sd( unix_fd );
if (!parent_sd && fstat( unix_fd, &st ) != -1)
parent_sd = get_xattr_acls( unix_fd, security_unix_uid_to_sid( st.st_uid ),
token_get_primary_group( current->process->token ) );
if (parent_sd)
{
sd = inherit_sd( parent_sd, is_dir );
free( parent_sd );
}
}
release_object( parent_fd );
}
return sd;
}
