static ssize_t
idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
{
struct rpc_inode *rpci = RPC_I(file_inode(filp));
struct idmap *idmap = (struct idmap *)rpci->private;
struct key_construction *cons;
struct idmap_msg im;
size_t namelen_in;
int ret = -ENOKEY;
/* If instantiation is successful, anyone waiting for key construction
* will have been woken up and someone else may now have used
* idmap_key_cons - so after this point we may no longer touch it.
*/
if (idmap->idmap_upcall_data == NULL)
goto out_noupcall;
cons = idmap->idmap_upcall_data->key_cons;
if (mlen != sizeof(im)) {
ret = -ENOSPC;
goto out;
}
if (copy_from_user(&im, src, mlen) != 0) {
ret = -EFAULT;
goto out;
}
if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
ret = -ENOKEY;
goto out;
}
namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
ret = -EINVAL;
goto out;
}
ret = nfs_idmap_read_and_verify_message(&im,
&idmap->idmap_upcall_data->idmap_msg,
cons->key, cons->authkey);
if (ret >= 0) {
key_set_timeout(cons->key, nfs_idmap_cache_timeout);
ret = mlen;
}
out:
nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
out_noupcall:
return ret;
}
/*
* Get the persistent keyring for a specific UID and link it to the nominated
* keyring.
*/
static long key_get_persistent(struct user_namespace *ns, kuid_t uid,
key_ref_t dest_ref)
{
struct keyring_index_key index_key;
struct key *persistent;
key_ref_t reg_ref, persistent_ref;
char buf[32];
long ret;
/* Look in the register if it exists */
index_key.type = &key_type_keyring;
index_key.description = buf;
index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid));
if (ns->persistent_keyring_register) {
reg_ref = make_key_ref(ns->persistent_keyring_register, true);
down_read(&ns->persistent_keyring_register_sem);
persistent_ref = find_key_to_update(reg_ref, &index_key);
up_read(&ns->persistent_keyring_register_sem);
if (persistent_ref)
goto found;
}
/* It wasn't in the register, so we'll need to create it. We might
* also need to create the register.
*/
down_write(&ns->persistent_keyring_register_sem);
persistent_ref = key_create_persistent(ns, uid, &index_key);
up_write(&ns->persistent_keyring_register_sem);
if (!IS_ERR(persistent_ref))
goto found;
return PTR_ERR(persistent_ref);
found:
ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK);
if (ret == 0) {
persistent = key_ref_to_ptr(persistent_ref);
ret = key_link(key_ref_to_ptr(dest_ref), persistent);
if (ret == 0) {
key_set_timeout(persistent, persistent_keyring_expiry);
ret = persistent->serial;
}
}
key_ref_put(persistent_ref);
return ret;
}
