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Commit 978d8f90 authored by Laura Garcia Liebana's avatar Laura Garcia Liebana Committed by Pablo Neira Ayuso
Browse files

netfilter: nft_numgen: add map lookups for numgen random operations 



This patch uses the map lookup already included to be applied
for random number generation.

Signed-off-by: default avatarLaura Garcia Liebana <nevola@gmail.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent e65eebec

net/netfilter/nft_numgen.c

+72 −4
Original line number Diff line number Diff line
@@ -166,18 +166,43 @@ struct nft_ng_random { 
	enum nft_registers      dreg:8;

	u32			modulus;

	u32			offset;

	struct nft_set		*map;

};



static u32 nft_ng_random_gen(struct nft_ng_random *priv)

{

	struct rnd_state *state = this_cpu_ptr(&nft_numgen_prandom_state);



	return reciprocal_scale(prandom_u32_state(state), priv->modulus) +

	       priv->offset;

}



static void nft_ng_random_eval(const struct nft_expr *expr,

			       struct nft_regs *regs,

			       const struct nft_pktinfo *pkt)

{

	struct nft_ng_random *priv = nft_expr_priv(expr);

	struct rnd_state *state = this_cpu_ptr(&nft_numgen_prandom_state);

	u32 val;



	val = reciprocal_scale(prandom_u32_state(state), priv->modulus);

	regs->data[priv->dreg] = val + priv->offset;

	regs->data[priv->dreg] = nft_ng_random_gen(priv);

}



static void nft_ng_random_map_eval(const struct nft_expr *expr,

				   struct nft_regs *regs,

				   const struct nft_pktinfo *pkt)

{

	struct nft_ng_random *priv = nft_expr_priv(expr);

	const struct nft_set *map = priv->map;

	const struct nft_set_ext *ext;

	u32 result;

	bool found;



	result = nft_ng_random_gen(priv);

	found = map->ops->lookup(nft_net(pkt), map, &result, &ext);

	if (!found)

		return;



	nft_data_copy(&regs->data[priv->dreg],

		      nft_set_ext_data(ext), map->dlen);

}



static int nft_ng_random_init(const struct nft_ctx *ctx,
@@ -204,6 +229,23 @@ static int nft_ng_random_init(const struct nft_ctx *ctx, 
					   NFT_DATA_VALUE, sizeof(u32));

}



static int nft_ng_random_map_init(const struct nft_ctx *ctx,

				  const struct nft_expr *expr,

				  const struct nlattr * const tb[])

{

	struct nft_ng_random *priv = nft_expr_priv(expr);

	u8 genmask = nft_genmask_next(ctx->net);



	nft_ng_random_init(ctx, expr, tb);

	priv->map = nft_set_lookup_global(ctx->net, ctx->table,

					  tb[NFTA_NG_SET_NAME],

					  tb[NFTA_NG_SET_ID], genmask);

	if (IS_ERR(priv->map))

		return PTR_ERR(priv->map);



	return 0;

}



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

{

	const struct nft_ng_random *priv = nft_expr_priv(expr);
@@ -212,6 +254,22 @@ static int nft_ng_random_dump(struct sk_buff *skb, const struct nft_expr *expr) 
			   priv->offset);

}



static int nft_ng_random_map_dump(struct sk_buff *skb,

				  const struct nft_expr *expr)

{

	const struct nft_ng_random *priv = nft_expr_priv(expr);



	if (nft_ng_dump(skb, priv->dreg, priv->modulus,

			NFT_NG_RANDOM, priv->offset) ||

	    nla_put_string(skb, NFTA_NG_SET_NAME, priv->map->name))

		goto nla_put_failure;



	return 0;



nla_put_failure:

	return -1;

}



static struct nft_expr_type nft_ng_type;

static const struct nft_expr_ops nft_ng_inc_ops = {

	.type		= &nft_ng_type,
@@ -237,6 +295,14 @@ static const struct nft_expr_ops nft_ng_random_ops = { 
	.dump		= nft_ng_random_dump,

};



static const struct nft_expr_ops nft_ng_random_map_ops = {

	.type		= &nft_ng_type,

	.size		= NFT_EXPR_SIZE(sizeof(struct nft_ng_random)),

	.eval		= nft_ng_random_map_eval,

	.init		= nft_ng_random_map_init,

	.dump		= nft_ng_random_map_dump,

};



static const struct nft_expr_ops *

nft_ng_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])

{
@@ -255,6 +321,8 @@ nft_ng_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) 
			return &nft_ng_inc_map_ops;

		return &nft_ng_inc_ops;

	case NFT_NG_RANDOM:

		if (tb[NFTA_NG_SET_NAME])

			return &nft_ng_random_map_ops;

		return &nft_ng_random_ops;

	}