[NETLINK]: Remove error pointer from netlink message handler

The error pointer argument in netlink message handlers is used
to signal the special case where processing has to be interrupted
because a dump was started but no error happened. Instead it is
simpler and more clear to return -EINTR and have netlink_run_queue()
deal with getting the queue right.

nfnetlink passed on this error pointer to its subsystem handlers
but only uses it to signal the start of a netlink dump. Therefore
it can be removed there as well.

This patch also cleans up the error handling in the affected
message handlers to be consistent since it had to be touched anyway.

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

1 files changed, 14 insertions, 26 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 4d2f2094e6d..5e52d6275ba 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1852,46 +1852,39 @@ static struct xfrm_link {
 	[XFRM_MSG_MIGRATE     - XFRM_MSG_BASE] = { .doit = xfrm_do_migrate    },
 };
 
-static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
+static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
 	struct rtattr *xfrma[XFRMA_MAX];
 	struct xfrm_link *link;
-	int type, min_len;
+	int type, min_len, err;
 
 	type = nlh->nlmsg_type;
-
-	/* Unknown message: reply with EINVAL */
 	if (type > XFRM_MSG_MAX)
-		goto err_einval;
+		return -EINVAL;
 
 	type -= XFRM_MSG_BASE;
 	link = &xfrm_dispatch[type];
 
 	/* All operations require privileges, even GET */
-	if (security_netlink_recv(skb, CAP_NET_ADMIN)) {
-		*errp = -EPERM;
-		return -1;
-	}
+	if (security_netlink_recv(skb, CAP_NET_ADMIN))
+		return -EPERM;
 
 	if ((type == (XFRM_MSG_GETSA - XFRM_MSG_BASE) ||
 	     type == (XFRM_MSG_GETPOLICY - XFRM_MSG_BASE)) &&
 	    (nlh->nlmsg_flags & NLM_F_DUMP)) {
 		if (link->dump == NULL)
-			goto err_einval;
-
-		if ((*errp = netlink_dump_start(xfrm_nl, skb, nlh,
-						link->dump, NULL)) != 0) {
-			return -1;
-		}
+			return -EINVAL;
 
-		netlink_queue_skip(nlh, skb);
-		return -1;
+		err = netlink_dump_start(xfrm_nl, skb, nlh, link->dump, NULL);
+		if (err == 0)
+			err = -EINTR;
+		return err;
 	}
 
 	memset(xfrma, 0, sizeof(xfrma));
 
 	if (nlh->nlmsg_len < (min_len = xfrm_msg_min[type]))
-		goto err_einval;
+		return -EINVAL;
 
 	if (nlh->nlmsg_len > min_len) {
 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
@@ -1901,7 +1894,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *err
 			unsigned short flavor = attr->rta_type;
 			if (flavor) {
 				if (flavor > XFRMA_MAX)
-					goto err_einval;
+					return -EINVAL;
 				xfrma[flavor - 1] = attr;
 			}
 			attr = RTA_NEXT(attr, attrlen);
@@ -1909,14 +1902,9 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *err
 	}
 
 	if (link->doit == NULL)
-		goto err_einval;
-	*errp = link->doit(skb, nlh, xfrma);
-
-	return *errp;
+		return -EINVAL;
 
-err_einval:
-	*errp = -EINVAL;
-	return -1;
+	return link->doit(skb, nlh, xfrma);
 }
 
 static void xfrm_netlink_rcv(struct sock *sk, int len)