kernel/drivers/block/drbd/drbd_nla.c
2024-07-22 17:22:30 +08:00

57 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <net/netlink.h>
#include <linux/drbd_genl_api.h>
#include "drbd_nla.h"
static int drbd_nla_check_mandatory(int maxtype, struct nlattr *nla)
{
struct nlattr *head = nla_data(nla);
int len = nla_len(nla);
int rem;
/*
* validate_nla (called from nla_parse_nested) ignores attributes
* beyond maxtype, and does not understand the DRBD_GENLA_F_MANDATORY flag.
* In order to have it validate attributes with the DRBD_GENLA_F_MANDATORY
* flag set also, check and remove that flag before calling
* nla_parse_nested.
*/
nla_for_each_attr(nla, head, len, rem) {
if (nla->nla_type & DRBD_GENLA_F_MANDATORY) {
nla->nla_type &= ~DRBD_GENLA_F_MANDATORY;
if (nla_type(nla) > maxtype)
return -EOPNOTSUPP;
}
}
return 0;
}
int drbd_nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla,
const struct nla_policy *policy)
{
int err;
err = drbd_nla_check_mandatory(maxtype, nla);
if (!err)
err = nla_parse_nested_deprecated(tb, maxtype, nla, policy,
NULL);
return err;
}
struct nlattr *drbd_nla_find_nested(int maxtype, struct nlattr *nla, int attrtype)
{
int err;
/*
* If any nested attribute has the DRBD_GENLA_F_MANDATORY flag set and
* we don't know about that attribute, reject all the nested
* attributes.
*/
err = drbd_nla_check_mandatory(maxtype, nla);
if (err)
return ERR_PTR(err);
return nla_find_nested(nla, attrtype);
}