Commit ee394f96 authored by Fernando Fernandez Mancera's avatar Fernando Fernandez Mancera Committed by Pablo Neira Ayuso
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netfilter: nft_synproxy: add synproxy stateful object support 



Register a new synproxy stateful object type into the stateful object
infrastructure.

Signed-off-by: default avatarFernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 3474a2c6

include/uapi/linux/netfilter/nf_tables.h

+2 −1
Original line number Diff line number Diff line
@@ -1481,7 +1481,8 @@ enum nft_ct_expectation_attributes { 
#define NFT_OBJECT_CT_TIMEOUT	7

#define NFT_OBJECT_SECMARK	8

#define NFT_OBJECT_CT_EXPECT	9

#define __NFT_OBJECT_MAX	10

#define NFT_OBJECT_SYNPROXY	10

#define __NFT_OBJECT_MAX	11

#define NFT_OBJECT_MAX		(__NFT_OBJECT_MAX - 1)



/**

net/netfilter/nft_synproxy.c

+122 −21
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ static void nft_synproxy_tcp_options(struct synproxy_options *opts, 
				     const struct tcphdr *tcp,

				     struct synproxy_net *snet,

				     struct nf_synproxy_info *info,

				     struct nft_synproxy *priv)

				     const struct nft_synproxy *priv)

{

	this_cpu_inc(snet->stats->syn_received);

	if (tcp->ece && tcp->cwr)
@@ -41,14 +41,13 @@ static void nft_synproxy_tcp_options(struct synproxy_options *opts, 
				   NF_SYNPROXY_OPT_ECN);

}



static void nft_synproxy_eval_v4(const struct nft_expr *expr,

static void nft_synproxy_eval_v4(const struct nft_synproxy *priv,

				 struct nft_regs *regs,

				 const struct nft_pktinfo *pkt,

				 const struct tcphdr *tcp,

				 struct tcphdr *_tcph,

				 struct synproxy_options *opts)

{

	struct nft_synproxy *priv = nft_expr_priv(expr);

	struct nf_synproxy_info info = priv->info;

	struct net *net = nft_net(pkt);

	struct synproxy_net *snet = synproxy_pernet(net);
@@ -73,14 +72,13 @@ static void nft_synproxy_eval_v4(const struct nft_expr *expr, 
}



#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)

static void nft_synproxy_eval_v6(const struct nft_expr *expr,

static void nft_synproxy_eval_v6(const struct nft_synproxy *priv,

				 struct nft_regs *regs,

				 const struct nft_pktinfo *pkt,

				 const struct tcphdr *tcp,

				 struct tcphdr *_tcph,

				 struct synproxy_options *opts)

{

	struct nft_synproxy *priv = nft_expr_priv(expr);

	struct nf_synproxy_info info = priv->info;

	struct net *net = nft_net(pkt);

	struct synproxy_net *snet = synproxy_pernet(net);
@@ -105,7 +103,7 @@ static void nft_synproxy_eval_v6(const struct nft_expr *expr, 
}

#endif /* CONFIG_NF_TABLES_IPV6*/



static void nft_synproxy_eval(const struct nft_expr *expr,

static void nft_synproxy_do_eval(const struct nft_synproxy *priv,

				 struct nft_regs *regs,

				 const struct nft_pktinfo *pkt)

{
@@ -140,23 +138,22 @@ static void nft_synproxy_eval(const struct nft_expr *expr, 


	switch (skb->protocol) {

	case htons(ETH_P_IP):

		nft_synproxy_eval_v4(expr, regs, pkt, tcp, &_tcph, &opts);

		nft_synproxy_eval_v4(priv, regs, pkt, tcp, &_tcph, &opts);

		return;

#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)

	case htons(ETH_P_IPV6):

		nft_synproxy_eval_v6(expr, regs, pkt, tcp, &_tcph, &opts);

		nft_synproxy_eval_v6(priv, regs, pkt, tcp, &_tcph, &opts);

		return;

#endif

	}

	regs->verdict.code = NFT_BREAK;

}



static int nft_synproxy_init(const struct nft_ctx *ctx,

			     const struct nft_expr *expr,

			     const struct nlattr * const tb[])

static int nft_synproxy_do_init(const struct nft_ctx *ctx,

				const struct nlattr * const tb[],

				struct nft_synproxy *priv)

{

	struct synproxy_net *snet = synproxy_pernet(ctx->net);

	struct nft_synproxy *priv = nft_expr_priv(expr);

	u32 flags;

	int err;
@@ -206,8 +203,7 @@ static int nft_synproxy_init(const struct nft_ctx *ctx, 
	return err;

}



static void nft_synproxy_destroy(const struct nft_ctx *ctx,

				 const struct nft_expr *expr)

static void nft_synproxy_do_destroy(const struct nft_ctx *ctx)

{

	struct synproxy_net *snet = synproxy_pernet(ctx->net);
@@ -229,10 +225,8 @@ static void nft_synproxy_destroy(const struct nft_ctx *ctx, 
	nf_ct_netns_put(ctx->net, ctx->family);

}



static int nft_synproxy_dump(struct sk_buff *skb, const struct nft_expr *expr)

static int nft_synproxy_do_dump(struct sk_buff *skb, struct nft_synproxy *priv)

{

	const struct nft_synproxy *priv = nft_expr_priv(expr);



	if (nla_put_be16(skb, NFTA_SYNPROXY_MSS, htons(priv->info.mss)) ||

	    nla_put_u8(skb, NFTA_SYNPROXY_WSCALE, priv->info.wscale) ||

	    nla_put_be32(skb, NFTA_SYNPROXY_FLAGS, htonl(priv->info.options)))
@@ -244,6 +238,15 @@ static int nft_synproxy_dump(struct sk_buff *skb, const struct nft_expr *expr) 
	return -1;

}



static void nft_synproxy_eval(const struct nft_expr *expr,

			      struct nft_regs *regs,

			      const struct nft_pktinfo *pkt)

{

	const struct nft_synproxy *priv = nft_expr_priv(expr);



	nft_synproxy_do_eval(priv, regs, pkt);

}



static int nft_synproxy_validate(const struct nft_ctx *ctx,

				 const struct nft_expr *expr,

				 const struct nft_data **data)
@@ -252,6 +255,28 @@ static int nft_synproxy_validate(const struct nft_ctx *ctx, 
						    (1 << NF_INET_FORWARD));

}



static int nft_synproxy_init(const struct nft_ctx *ctx,

			     const struct nft_expr *expr,

			     const struct nlattr * const tb[])

{

	struct nft_synproxy *priv = nft_expr_priv(expr);



	return nft_synproxy_do_init(ctx, tb, priv);

}



static void nft_synproxy_destroy(const struct nft_ctx *ctx,

				 const struct nft_expr *expr)

{

	nft_synproxy_do_destroy(ctx);

}



static int nft_synproxy_dump(struct sk_buff *skb, const struct nft_expr *expr)

{

	struct nft_synproxy *priv = nft_expr_priv(expr);



	return nft_synproxy_do_dump(skb, priv);

}



static struct nft_expr_type nft_synproxy_type;

static const struct nft_expr_ops nft_synproxy_ops = {

	.eval		= nft_synproxy_eval,
@@ -271,14 +296,89 @@ static struct nft_expr_type nft_synproxy_type __read_mostly = { 
	.maxattr	= NFTA_SYNPROXY_MAX,

};



static int nft_synproxy_obj_init(const struct nft_ctx *ctx,

				 const struct nlattr * const tb[],

				 struct nft_object *obj)

{

	struct nft_synproxy *priv = nft_obj_data(obj);



	return nft_synproxy_do_init(ctx, tb, priv);

}



static void nft_synproxy_obj_destroy(const struct nft_ctx *ctx,

				     struct nft_object *obj)

{

	nft_synproxy_do_destroy(ctx);

}



static int nft_synproxy_obj_dump(struct sk_buff *skb,

				 struct nft_object *obj, bool reset)

{

	struct nft_synproxy *priv = nft_obj_data(obj);



	return nft_synproxy_do_dump(skb, priv);

}



static void nft_synproxy_obj_eval(struct nft_object *obj,

				  struct nft_regs *regs,

				  const struct nft_pktinfo *pkt)

{

	const struct nft_synproxy *priv = nft_obj_data(obj);



	nft_synproxy_do_eval(priv, regs, pkt);

}



static void nft_synproxy_obj_update(struct nft_object *obj,

				    struct nft_object *newobj)

{

	struct nft_synproxy *newpriv = nft_obj_data(newobj);

	struct nft_synproxy *priv = nft_obj_data(obj);



	priv->info = newpriv->info;

}



static struct nft_object_type nft_synproxy_obj_type;

static const struct nft_object_ops nft_synproxy_obj_ops = {

	.type		= &nft_synproxy_obj_type,

	.size		= sizeof(struct nft_synproxy),

	.init		= nft_synproxy_obj_init,

	.destroy	= nft_synproxy_obj_destroy,

	.dump		= nft_synproxy_obj_dump,

	.eval		= nft_synproxy_obj_eval,

	.update		= nft_synproxy_obj_update,

};



static struct nft_object_type nft_synproxy_obj_type __read_mostly = {

	.type		= NFT_OBJECT_SYNPROXY,

	.ops		= &nft_synproxy_obj_ops,

	.maxattr	= NFTA_SYNPROXY_MAX,

	.policy		= nft_synproxy_policy,

	.owner		= THIS_MODULE,

};



static int __init nft_synproxy_module_init(void)

{

	return nft_register_expr(&nft_synproxy_type);

	int err;



	err = nft_register_obj(&nft_synproxy_obj_type);

	if (err < 0)

		return err;



	err = nft_register_expr(&nft_synproxy_type);

	if (err < 0)

		goto err;



	return 0;



err:

	nft_unregister_obj(&nft_synproxy_obj_type);

	return err;

}



static void __exit nft_synproxy_module_exit(void)

{

	return nft_unregister_expr(&nft_synproxy_type);

	nft_unregister_expr(&nft_synproxy_type);

	nft_unregister_obj(&nft_synproxy_obj_type);

}



module_init(nft_synproxy_module_init);
@@ -287,3 +387,4 @@ module_exit(nft_synproxy_module_exit); 
MODULE_LICENSE("GPL");

MODULE_AUTHOR("Fernando Fernandez <ffmancera@riseup.net>");

MODULE_ALIAS_NFT_EXPR("synproxy");

MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_SYNPROXY);