}
/*
- * It would be nice to scramble the ID space, so that the value of the
- * files_struct pointer is not exposed to userspace. Symmetric crypto
- * functions are overkill, since the inverse function doesn't need to
- * be implemented (though it does have to exist). Is there something
- * simpler?
+ * Scramble the ID space with XTEA, so that the value of the files_struct
+ * pointer is not exposed to userspace.
*/
-static inline u64 fuse_lock_owner_id(fl_owner_t id)
+static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
{
- return (unsigned long) id;
+ u32 *k = fc->scramble_key;
+ u64 v = (unsigned long) id;
+ u32 v0 = v;
+ u32 v1 = v >> 32;
+ u32 sum = 0;
+ int i;
+
+ for (i = 0; i < 32; i++) {
+ v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
+ sum += 0x9E3779B9;
+ v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
+ }
+
+ return (u64) v0 + ((u64) v1 << 32);
}
static int fuse_flush(struct file *file, fl_owner_t id)
req = fuse_get_req_nofail(fc, file);
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
- inarg.lock_owner = fuse_lock_owner_id(id);
+ inarg.lock_owner = fuse_lock_owner_id(fc, id);
req->in.h.opcode = FUSE_FLUSH;
req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1;
const struct file_lock *fl, int opcode, pid_t pid)
{
struct inode *inode = file->f_dentry->d_inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_file *ff = file->private_data;
struct fuse_lk_in *arg = &req->misc.lk_in;
arg->fh = ff->fh;
- arg->owner = fuse_lock_owner_id(fl->fl_owner);
+ arg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
arg->lk.start = fl->fl_start;
arg->lk.end = fl->fl_end;
arg->lk.type = fl->fl_type;
/* no mmap and sendfile */
};
-static struct address_space_operations fuse_file_aops = {
+static const struct address_space_operations fuse_file_aops = {
.readpage = fuse_readpage,
.prepare_write = fuse_prepare_write,
.commit_write = fuse_commit_write,