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Commit e487eb99 authored by Holger Eitzenberger's avatar Holger Eitzenberger Committed by Patrick McHardy
Browse files

netlink: add nla_policy_len() 



It calculates the max. length of a Netlink policy, which is usefull
for allocating Netlink buffers roughly the size of the actual
message.

Signed-off-by: default avatarHolger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent d0dba725

include/net/netlink.h

+1 −0
Original line number Diff line number Diff line
@@ -230,6 +230,7 @@ extern int nla_validate(struct nlattr *head, int len, int maxtype, 
extern int		nla_parse(struct nlattr *tb[], int maxtype,

				  struct nlattr *head, int len,

				  const struct nla_policy *policy);

extern int		nla_policy_len(const struct nla_policy *, int);

extern struct nlattr *	nla_find(struct nlattr *head, int len, int attrtype);

extern size_t		nla_strlcpy(char *dst, const struct nlattr *nla,

				    size_t dstsize);

net/netlink/attr.c

+27 −0
Original line number Diff line number Diff line
@@ -132,6 +132,32 @@ int nla_validate(struct nlattr *head, int len, int maxtype, 
	return err;

}



/**

 * nla_policy_len - Determin the max. length of a policy

 * @policy: policy to use

 * @n: number of policies

 *

 * Determines the max. length of the policy.  It is currently used

 * to allocated Netlink buffers roughly the size of the actual

 * message.

 *

 * Returns 0 on success or a negative error code.

 */

int

nla_policy_len(const struct nla_policy *p, int n)

{

	int i, len = 0;



	for (i = 0; i < n; i++) {

		if (p->len)

			len += nla_total_size(p->len);

		else if (nla_attr_minlen[p->type])

			len += nla_total_size(nla_attr_minlen[p->type]);

	}



	return len;

}



/**

 * nla_parse - Parse a stream of attributes into a tb buffer

 * @tb: destination array with maxtype+1 elements
@@ -456,6 +482,7 @@ int nla_append(struct sk_buff *skb, int attrlen, const void *data) 
}



EXPORT_SYMBOL(nla_validate);

EXPORT_SYMBOL(nla_policy_len);

EXPORT_SYMBOL(nla_parse);

EXPORT_SYMBOL(nla_find);

EXPORT_SYMBOL(nla_strlcpy);