![Patrick McHardy](/assets/img/avatar_default.png)
Split the expression ops into two parts and support overloading of the runtime expression ops based on the requested function through a ->select_ops() callback. This can be used to provide optimized implementations, for instance for loading small aligned amounts of data from the packet or inlining frequently used operations into the main evaluation loop. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
142 lines
3.6 KiB
C
142 lines
3.6 KiB
C
/*
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* Copyright (c) 2009 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/rbtree.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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struct nft_lookup {
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struct nft_set *set;
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enum nft_registers sreg:8;
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enum nft_registers dreg:8;
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struct nft_set_binding binding;
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};
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static void nft_lookup_eval(const struct nft_expr *expr,
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struct nft_data data[NFT_REG_MAX + 1],
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const struct nft_pktinfo *pkt)
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{
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const struct nft_lookup *priv = nft_expr_priv(expr);
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const struct nft_set *set = priv->set;
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if (set->ops->lookup(set, &data[priv->sreg], &data[priv->dreg]))
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return;
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data[NFT_REG_VERDICT].verdict = NFT_BREAK;
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}
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static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = {
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[NFTA_LOOKUP_SET] = { .type = NLA_STRING },
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[NFTA_LOOKUP_SREG] = { .type = NLA_U32 },
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[NFTA_LOOKUP_DREG] = { .type = NLA_U32 },
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};
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static int nft_lookup_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_lookup *priv = nft_expr_priv(expr);
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struct nft_set *set;
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int err;
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if (tb[NFTA_LOOKUP_SET] == NULL ||
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tb[NFTA_LOOKUP_SREG] == NULL)
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return -EINVAL;
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set = nf_tables_set_lookup(ctx->table, tb[NFTA_LOOKUP_SET]);
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if (IS_ERR(set))
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return PTR_ERR(set);
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priv->sreg = ntohl(nla_get_be32(tb[NFTA_LOOKUP_SREG]));
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err = nft_validate_input_register(priv->sreg);
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if (err < 0)
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return err;
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if (tb[NFTA_LOOKUP_DREG] != NULL) {
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if (!(set->flags & NFT_SET_MAP))
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return -EINVAL;
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priv->dreg = ntohl(nla_get_be32(tb[NFTA_LOOKUP_DREG]));
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err = nft_validate_output_register(priv->dreg);
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if (err < 0)
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return err;
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if (priv->dreg == NFT_REG_VERDICT) {
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if (set->dtype != NFT_DATA_VERDICT)
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return -EINVAL;
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} else if (set->dtype == NFT_DATA_VERDICT)
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return -EINVAL;
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} else if (set->flags & NFT_SET_MAP)
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return -EINVAL;
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err = nf_tables_bind_set(ctx, set, &priv->binding);
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if (err < 0)
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return err;
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priv->set = set;
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return 0;
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}
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static void nft_lookup_destroy(const struct nft_expr *expr)
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{
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struct nft_lookup *priv = nft_expr_priv(expr);
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nf_tables_unbind_set(NULL, priv->set, &priv->binding);
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}
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static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_lookup *priv = nft_expr_priv(expr);
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if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_LOOKUP_SREG, htonl(priv->sreg)))
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goto nla_put_failure;
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if (priv->set->flags & NFT_SET_MAP)
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if (nla_put_be32(skb, NFTA_LOOKUP_DREG, htonl(priv->dreg)))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static struct nft_expr_type nft_lookup_type;
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static const struct nft_expr_ops nft_lookup_ops = {
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.type = &nft_lookup_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
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.eval = nft_lookup_eval,
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.init = nft_lookup_init,
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.destroy = nft_lookup_destroy,
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.dump = nft_lookup_dump,
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};
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static struct nft_expr_type nft_lookup_type __read_mostly = {
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.name = "lookup",
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.ops = &nft_lookup_ops,
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.policy = nft_lookup_policy,
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.maxattr = NFTA_LOOKUP_MAX,
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.owner = THIS_MODULE,
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};
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int __init nft_lookup_module_init(void)
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{
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return nft_register_expr(&nft_lookup_type);
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}
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void nft_lookup_module_exit(void)
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{
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nft_unregister_expr(&nft_lookup_type);
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}
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