netlink: Improve returned error codes

Make nlmsg_trim(), nlmsg_cancel(), genlmsg_cancel(), and
nla_nest_cancel() void functions.

Return -EMSGSIZE instead of -1 if the provided message buffer is not
big enough.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 11 deletions

diff --git a/include/net/netlink.h b/include/net/netlink.h
index 112dcdf7e34e..dfc3701dfcc3 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -556,14 +556,12 @@ static inline void *nlmsg_get_pos(struct sk_buff *skb)
  * @skb: socket buffer the message is stored in
  * @mark: mark to trim to
  *
- * Trims the message to the provided mark. Returns -1.
+ * Trims the message to the provided mark.
  */
-static inline int nlmsg_trim(struct sk_buff *skb, const void *mark)
+static inline void nlmsg_trim(struct sk_buff *skb, const void *mark)
 {
 	if (mark)
 		skb_trim(skb, (unsigned char *) mark - skb->data);
-
-	return -1;
 }
 
 /**
@@ -572,11 +570,11 @@ static inline int nlmsg_trim(struct sk_buff *skb, const void *mark)
  * @nlh: netlink message header
  *
  * Removes the complete netlink message including all
- * attributes from the socket buffer again. Returns -1.
+ * attributes from the socket buffer again.
  */
-static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
+static inline void nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
-	return nlmsg_trim(skb, nlh);
+	nlmsg_trim(skb, nlh);
 }
 
 /**
@@ -775,7 +773,7 @@ static inline int __nla_parse_nested_compat(struct nlattr *tb[], int maxtype,
 	int nested_len = nla_len(nla) - NLA_ALIGN(len);
 
 	if (nested_len < 0)
-		return -1;
+		return -EINVAL;
 	if (nested_len >= nla_attr_size(0))
 		return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
 				 nested_len, policy);
@@ -1080,11 +1078,11 @@ static inline int nla_nest_compat_end(struct sk_buff *skb, struct nlattr *start)
  * @start: container attribute
  *
  * Removes the container attribute and including all nested
- * attributes. Returns -1.
+ * attributes. Returns -EMSGSIZE
  */
-static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
+static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
 {
-	return nlmsg_trim(skb, start);
+	nlmsg_trim(skb, start);
 }
 
 /**