blob: b2d4791498a660618aa6f603db35fd0c0b5a94e7 [file] [log] [blame]
Andreas Gruenbacher01b39b52011-06-10 12:57:26 +02001#include <linux/kernel.h>
2#include <net/netlink.h>
3#include <linux/drbd_genl_api.h>
4#include "drbd_nla.h"
5
6static int drbd_nla_check_mandatory(int maxtype, struct nlattr *nla)
7{
8 struct nlattr *head = nla_data(nla);
9 int len = nla_len(nla);
10 int rem;
11
12 /*
13 * validate_nla (called from nla_parse_nested) ignores attributes
14 * beyond maxtype, and does not understand the DRBD_GENLA_F_MANDATORY flag.
15 * In order to have it validate attributes with the DRBD_GENLA_F_MANDATORY
16 * flag set also, check and remove that flag before calling
17 * nla_parse_nested.
18 */
19
20 nla_for_each_attr(nla, head, len, rem) {
21 if (nla->nla_type & DRBD_GENLA_F_MANDATORY) {
22 nla->nla_type &= ~DRBD_GENLA_F_MANDATORY;
23 if (nla_type(nla) > maxtype)
24 return -EOPNOTSUPP;
25 }
26 }
27 return 0;
28}
29
30int drbd_nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla,
31 const struct nla_policy *policy)
32{
33 int err;
34
35 err = drbd_nla_check_mandatory(maxtype, nla);
36 if (!err)
37 err = nla_parse_nested(tb, maxtype, nla, policy);
38
39 return err;
40}
41
42struct nlattr *drbd_nla_find_nested(int maxtype, struct nlattr *nla, int attrtype)
43{
44 int err;
45 /*
46 * If any nested attribute has the DRBD_GENLA_F_MANDATORY flag set and
47 * we don't know about that attribute, reject all the nested
48 * attributes.
49 */
50 err = drbd_nla_check_mandatory(maxtype, nla);
51 if (err)
52 return ERR_PTR(err);
53 return nla_find_nested(nla, attrtype);
54}