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