libnl: add more helpers to align attributes on 64-bit
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netlink.h b/include/net/netlink.h
index 3c1fd92..6f51a8a 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -244,13 +244,21 @@
int nla_memcmp(const struct nlattr *nla, const void *data, size_t size);
int nla_strcmp(const struct nlattr *nla, const char *str);
struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
+struct nlattr *__nla_reserve_64bit(struct sk_buff *skb, int attrtype,
+ int attrlen, int padattr);
void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen);
+struct nlattr *nla_reserve_64bit(struct sk_buff *skb, int attrtype,
+ int attrlen, int padattr);
void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen);
void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
const void *data);
+void __nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
+ const void *data, int padattr);
void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data);
+int nla_put_64bit(struct sk_buff *skb, int attrtype, int attrlen,
+ const void *data, int padattr);
int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data);
int nla_append(struct sk_buff *skb, int attrlen, const void *data);
@@ -1231,6 +1239,27 @@
}
/**
+ * nla_need_padding_for_64bit - test 64-bit alignment of the next attribute
+ * @skb: socket buffer the message is stored in
+ *
+ * Return true if padding is needed to align the next attribute (nla_data()) to
+ * a 64-bit aligned area.
+ */
+static inline bool nla_need_padding_for_64bit(struct sk_buff *skb)
+{
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ /* The nlattr header is 4 bytes in size, that's why we test
+ * if the skb->data _is_ aligned. A NOP attribute, plus
+ * nlattr header for next attribute, will make nla_data()
+ * 8-byte aligned.
+ */
+ if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8))
+ return true;
+#endif
+ return false;
+}
+
+/**
* nla_align_64bit - 64-bit align the nla_data() of next attribute
* @skb: socket buffer the message is stored in
* @padattr: attribute type for the padding
@@ -1244,16 +1273,10 @@
*/
static inline int nla_align_64bit(struct sk_buff *skb, int padattr)
{
-#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
- /* The nlattr header is 4 bytes in size, that's why we test
- * if the skb->data _is_ aligned. This NOP attribute, plus
- * nlattr header for next attribute, will make nla_data()
- * 8-byte aligned.
- */
- if (IS_ALIGNED((unsigned long)skb_tail_pointer(skb), 8) &&
+ if (nla_need_padding_for_64bit(skb) &&
!nla_reserve(skb, padattr, 0))
return -EMSGSIZE;
-#endif
+
return 0;
}