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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: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Laura Garcia Liebana 2018-05-11 00:14:17 +02:00 committed by Pablo Neira Ayuso
parent e65eebec9c
commit 978d8f9055
1 changed files with 72 additions and 4 deletions
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76
net/netfilter/nft_numgen.c
View File

@ -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;
}