Commit 5948ed29 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: ctnetlink: use dump structure instead of raw args 



netlink_dump structure has a union of 'long args[6]' and a context
buffer as scratch space.

Convert ctnetlink to use a structure, its easier to read than the
raw 'args' usage which comes with no type checks and no readable names.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 98eee88b

net/netfilter/nf_conntrack_netlink.c

+24 −12
Original line number Diff line number Diff line
@@ -58,6 +58,12 @@ 


MODULE_LICENSE("GPL");



struct ctnetlink_list_dump_ctx {

	struct nf_conn *last;

	unsigned int cpu;

	bool done;

};



static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,

				const struct nf_conntrack_tuple *tuple,

				const struct nf_conntrack_l4proto *l4proto)
@@ -1694,14 +1700,18 @@ static int ctnetlink_get_conntrack(struct sk_buff *skb, 


static int ctnetlink_done_list(struct netlink_callback *cb)

{

	if (cb->args[1])

		nf_ct_put((struct nf_conn *)cb->args[1]);

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



	if (ctx->last)

		nf_ct_put(ctx->last);



	return 0;

}



static int

ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying)

{

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

	struct nf_conn *ct, *last;

	struct nf_conntrack_tuple_hash *h;

	struct hlist_nulls_node *n;
@@ -1712,12 +1722,12 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying 
	struct hlist_nulls_head *list;

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



	if (cb->args[2])

	if (ctx->done)

		return 0;



	last = (struct nf_conn *)cb->args[1];

	last = ctx->last;



	for (cpu = cb->args[0]; cpu < nr_cpu_ids; cpu++) {

	for (cpu = ctx->cpu; cpu < nr_cpu_ids; cpu++) {

		struct ct_pcpu *pcpu;



		if (!cpu_possible(cpu))
@@ -1731,10 +1741,10 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying 
			ct = nf_ct_tuplehash_to_ctrack(h);

			if (l3proto && nf_ct_l3num(ct) != l3proto)

				continue;

			if (cb->args[1]) {

			if (ctx->last) {

				if (ct != last)

					continue;

				cb->args[1] = 0;

				ctx->last = NULL;

			}



			/* We can't dump extension info for the unconfirmed
@@ -1751,19 +1761,19 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying 
			if (res < 0) {

				if (!refcount_inc_not_zero(&ct->ct_general.use))

					continue;

				cb->args[0] = cpu;

				cb->args[1] = (unsigned long)ct;

				ctx->cpu = cpu;

				ctx->last = ct;

				spin_unlock_bh(&pcpu->lock);

				goto out;

			}

		}

		if (cb->args[1]) {

			cb->args[1] = 0;

		if (ctx->last) {

			ctx->last = NULL;

			goto restart;

		}

		spin_unlock_bh(&pcpu->lock);

	}

	cb->args[2] = 1;

	ctx->done = true;

out:

	if (last)

		nf_ct_put(last);
@@ -3877,6 +3887,8 @@ static int __init ctnetlink_init(void) 
{

	int ret;



	BUILD_BUG_ON(sizeof(struct ctnetlink_list_dump_ctx) > sizeof_field(struct netlink_callback, ctx));



	ret = nfnetlink_subsys_register(&ctnl_subsys);

	if (ret < 0) {

		pr_err("ctnetlink_init: cannot register with nfnetlink.\n");