From 978d8f9055c3a7c35db2ac99cd2580b993396e33 Mon Sep 17 00:00:00 2001 From: Laura Garcia Liebana Date: Fri, 11 May 2018 00:14:17 +0200 Subject: [PATCH] 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 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_numgen.c | 76 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 72 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nft_numgen.c b/net/netfilter/nft_numgen.c index 8a64db8f2e69..cdbc62a53933 100644 --- a/net/netfilter/nft_numgen.c +++ b/net/netfilter/nft_numgen.c @@ -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(®s->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; } -- 2.11.0