netfilter: conntrack: split inner loop of list dumping to own function

This allows code re-use in the followup patch.
No functional changes intended.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_netlink.c

@@ -1708,6 +1708,47 @@ static int ctnetlink_done_list(struct netlink_callback *cb)
 	return 0;
 }
 
+static int ctnetlink_dump_one_entry(struct sk_buff *skb,
+				    struct netlink_callback *cb,
+				    struct nf_conn *ct,
+				    bool dying)
+{
+	struct ctnetlink_list_dump_ctx *ctx = (void *)cb->ctx;
+	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
+	u8 l3proto = nfmsg->nfgen_family;
+	int res;
+
+	if (l3proto && nf_ct_l3num(ct) != l3proto)
+		return 0;
+
+	if (ctx->last) {
+		if (ct != ctx->last)
+			return 0;
+
+		ctx->last = NULL;
+	}
+
+	/* We can't dump extension info for the unconfirmed
+	 * list because unconfirmed conntracks can have
+	 * ct->ext reallocated (and thus freed).
+	 *
+	 * In the dying list case ct->ext can't be free'd
+	 * until after we drop pcpu->lock.
+	 */
+	res = ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid,
+				  cb->nlh->nlmsg_seq,
+				  NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
+				  ct, dying, 0);
+	if (res < 0) {
+		if (!refcount_inc_not_zero(&ct->ct_general.use))
+			return 0;
+
+		ctx->last = ct;
+	}
+
+	return res;
+}
+
 static int
 ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying)
 {
@@ -1715,12 +1756,9 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
 	struct nf_conn *ct, *last;
 	struct nf_conntrack_tuple_hash *h;
 	struct hlist_nulls_node *n;
-	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
-	u_int8_t l3proto = nfmsg->nfgen_family;
-	int res;
-	int cpu;
 	struct hlist_nulls_head *list;
 	struct net *net = sock_net(skb->sk);
+	int res, cpu;
 
 	if (ctx->done)
 		return 0;
@@ -1739,30 +1777,10 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
 restart:
 		hlist_nulls_for_each_entry(h, n, list, hnnode) {
 			ct = nf_ct_tuplehash_to_ctrack(h);
-			if (l3proto && nf_ct_l3num(ct) != l3proto)
-				continue;
-			if (ctx->last) {
-				if (ct != last)
-					continue;
-				ctx->last = NULL;
-			}
 
-			/* We can't dump extension info for the unconfirmed
-			 * list because unconfirmed conntracks can have
-			 * ct->ext reallocated (and thus freed).
-			 *
-			 * In the dying list case ct->ext can't be free'd
-			 * until after we drop pcpu->lock.
-			 */
-			res = ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid,
-						  cb->nlh->nlmsg_seq,
-						  NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
-						  ct, dying, 0);
+			res = ctnetlink_dump_one_entry(skb, cb, ct, dying);
 			if (res < 0) {
-				if (!refcount_inc_not_zero(&ct->ct_general.use))
-					continue;
 				ctx->cpu = cpu;
-				ctx->last = ct;
 				spin_unlock_bh(&pcpu->lock);
 				goto out;
 			}