Commit 08d07f25 authored by Florian Westphal's avatar Florian Westphal
Browse files

netfilter: ctnetlink: remove refcounting in dying list dumping 



There is no need to keep the object alive via refcount, use a cookie and
then use that as the skip hint for dump resumption.

Unlike the two earlier, similar patches in this file, this is a cleanup
without intended side effects.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
parent 5c69e0b3

net/netfilter/nf_conntrack_netlink.c

+10 −29
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ MODULE_LICENSE("GPL"); 
MODULE_DESCRIPTION("List and change connection tracking table");



struct ctnetlink_list_dump_ctx {

	struct nf_conn *last;

	unsigned long last_id;

	unsigned int cpu;

	bool done;

};
@@ -1733,16 +1733,6 @@ static int ctnetlink_get_conntrack(struct sk_buff *skb, 
	return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);

}



static int ctnetlink_done_list(struct netlink_callback *cb)

{

	struct ctnetlink_list_dump_ctx *ctx = (void *)cb->ctx;



	if (ctx->last)

		nf_ct_put(ctx->last);



	return 0;

}



#ifdef CONFIG_NF_CONNTRACK_EVENTS

static int ctnetlink_dump_one_entry(struct sk_buff *skb,

				    struct netlink_callback *cb,
@@ -1757,11 +1747,11 @@ static int ctnetlink_dump_one_entry(struct sk_buff *skb, 
	if (l3proto && nf_ct_l3num(ct) != l3proto)

		return 0;



	if (ctx->last) {

		if (ct != ctx->last)

	if (ctx->last_id) {

		if (ctnetlink_get_id(ct) != ctx->last_id)

			return 0;



		ctx->last = NULL;

		ctx->last_id = 0;

	}



	/* We can't dump extension info for the unconfirmed
@@ -1775,12 +1765,8 @@ static int ctnetlink_dump_one_entry(struct sk_buff *skb, 
				  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;

	}

	if (res < 0)

		ctx->last_id = ctnetlink_get_id(ct);



	return res;

}
@@ -1796,10 +1782,10 @@ static int 
ctnetlink_dump_dying(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct ctnetlink_list_dump_ctx *ctx = (void *)cb->ctx;

	struct nf_conn *last = ctx->last;

#ifdef CONFIG_NF_CONNTRACK_EVENTS

	const struct net *net = sock_net(skb->sk);

	struct nf_conntrack_net_ecache *ecache_net;

	unsigned long last_id = ctx->last_id;

	struct nf_conntrack_tuple_hash *h;

	struct hlist_nulls_node *n;

#endif
@@ -1807,7 +1793,7 @@ ctnetlink_dump_dying(struct sk_buff *skb, struct netlink_callback *cb) 
	if (ctx->done)

		return 0;



	ctx->last = NULL;

	ctx->last_id = 0;



#ifdef CONFIG_NF_CONNTRACK_EVENTS

	ecache_net = nf_conn_pernet_ecache(net);
@@ -1818,24 +1804,21 @@ ctnetlink_dump_dying(struct sk_buff *skb, struct netlink_callback *cb) 
		int res;



		ct = nf_ct_tuplehash_to_ctrack(h);

		if (last && last != ct)

		if (last_id && last_id != ctnetlink_get_id(ct))

			continue;



		res = ctnetlink_dump_one_entry(skb, cb, ct, true);

		if (res < 0) {

			spin_unlock_bh(&ecache_net->dying_lock);

			nf_ct_put(last);

			return skb->len;

		}



		nf_ct_put(last);

		last = NULL;

		last_id = 0;

	}



	spin_unlock_bh(&ecache_net->dying_lock);

#endif

	ctx->done = true;

	nf_ct_put(last);



	return skb->len;

}
@@ -1847,7 +1830,6 @@ static int ctnetlink_get_ct_dying(struct sk_buff *skb, 
	if (info->nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.dump = ctnetlink_dump_dying,

			.done = ctnetlink_done_list,

		};

		return netlink_dump_start(info->sk, skb, info->nlh, &c);

	}
@@ -1862,7 +1844,6 @@ static int ctnetlink_get_ct_unconfirmed(struct sk_buff *skb, 
	if (info->nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.dump = ctnetlink_dump_unconfirmed,

			.done = ctnetlink_done_list,

		};

		return netlink_dump_start(info->sk, skb, info->nlh, &c);

	}