From e487eb99cf9381a4f8254fa01747a85818da612b Mon Sep 17 00:00:00 2001 From: Holger Eitzenberger Date: Wed, 25 Mar 2009 18:26:30 +0100 Subject: [PATCH] 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: Holger Eitzenberger Signed-off-by: Patrick McHardy --- include/net/netlink.h | 1 + net/netlink/attr.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/include/net/netlink.h b/include/net/netlink.h index 8a6150a3f4c7..eddb50289d6d 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -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); diff --git a/net/netlink/attr.c b/net/netlink/attr.c index 56c3ce7fe29a..ae32c573df00 100644 --- a/net/netlink/attr.c +++ b/net/netlink/attr.c @@ -132,6 +132,32 @@ errout: 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); -- 2.20.1