Commit 1578c328 authored by Phil Sutter's avatar Phil Sutter Committed by Pablo Neira Ayuso
Browse files

netfilter: nf_tables: Introduce nf_tables_getrule_single() 



Outsource the reply skb preparation for non-dump getrule requests into a
distinct function. Prep work for rule reset locking.

Signed-off-by: default avatarPhil Sutter <phil@nwl.cc>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 88773930

net/netfilter/nf_tables_api.c

+43 −31
Original line number Diff line number Diff line
@@ -3586,65 +3586,81 @@ static int nf_tables_dump_rules_done(struct netlink_callback *cb) 
}



/* called with rcu_read_lock held */

static int nf_tables_getrule(struct sk_buff *skb, const struct nfnl_info *info,

			     const struct nlattr * const nla[])

static struct sk_buff *

nf_tables_getrule_single(u32 portid, const struct nfnl_info *info,

			 const struct nlattr * const nla[], bool reset)

{

	struct nftables_pernet *nft_net = nft_pernet(info->net);

	struct netlink_ext_ack *extack = info->extack;

	u8 genmask = nft_genmask_cur(info->net);

	u8 family = info->nfmsg->nfgen_family;

	u32 portid = NETLINK_CB(skb).portid;

	const struct nft_chain *chain;

	const struct nft_rule *rule;

	struct net *net = info->net;

	struct nft_table *table;

	struct sk_buff *skb2;

	bool reset = false;

	char *buf;

	int err;



	if (info->nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start= nf_tables_dump_rules_start,

			.dump = nf_tables_dump_rules,

			.done = nf_tables_dump_rules_done,

			.module = THIS_MODULE,

			.data = (void *)nla,

		};



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

	}



	table = nft_table_lookup(net, nla[NFTA_RULE_TABLE], family, genmask, 0);

	if (IS_ERR(table)) {

		NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_TABLE]);

		return PTR_ERR(table);

		return ERR_CAST(table);

	}



	chain = nft_chain_lookup(net, table, nla[NFTA_RULE_CHAIN], genmask);

	if (IS_ERR(chain)) {

		NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN]);

		return PTR_ERR(chain);

		return ERR_CAST(chain);

	}



	rule = nft_rule_lookup(chain, nla[NFTA_RULE_HANDLE]);

	if (IS_ERR(rule)) {

		NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_HANDLE]);

		return PTR_ERR(rule);

		return ERR_CAST(rule);

	}



	skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);

	if (!skb2)

		return -ENOMEM;



	if (NFNL_MSG_TYPE(info->nlh->nlmsg_type) == NFT_MSG_GETRULE_RESET)

		reset = true;

		return ERR_PTR(-ENOMEM);



	err = nf_tables_fill_rule_info(skb2, net, portid,

				       info->nlh->nlmsg_seq, NFT_MSG_NEWRULE, 0,

				       family, table, chain, rule, 0, reset);

	if (err < 0)

		goto err_fill_rule_info;

	if (err < 0) {

		kfree_skb(skb2);

		return ERR_PTR(err);

	}



	return skb2;

}



static int nf_tables_getrule(struct sk_buff *skb, const struct nfnl_info *info,

			     const struct nlattr * const nla[])

{

	struct nftables_pernet *nft_net = nft_pernet(info->net);

	u32 portid = NETLINK_CB(skb).portid;

	struct net *net = info->net;

	struct sk_buff *skb2;

	bool reset = false;

	char *buf;



	if (info->nlh->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.start= nf_tables_dump_rules_start,

			.dump = nf_tables_dump_rules,

			.done = nf_tables_dump_rules_done,

			.module = THIS_MODULE,

			.data = (void *)nla,

		};



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

	}



	if (NFNL_MSG_TYPE(info->nlh->nlmsg_type) == NFT_MSG_GETRULE_RESET)

		reset = true;



	skb2 = nf_tables_getrule_single(portid, info, nla, reset);

	if (IS_ERR(skb2))

		return PTR_ERR(skb2);



	if (!reset)

		return nfnetlink_unicast(skb2, net, portid);
@@ -3658,10 +3674,6 @@ static int nf_tables_getrule(struct sk_buff *skb, const struct nfnl_info *info, 
	kfree(buf);



	return nfnetlink_unicast(skb2, net, portid);



err_fill_rule_info:

	kfree_skb(skb2);

	return err;

}



void nf_tables_rule_destroy(const struct nft_ctx *ctx, struct nft_rule *rule)