![Florian Westphal](/assets/img/avatar_default.png)
With CONFIG_RETPOLINE its faster to add an if (ptr == &foo_func) check and and use direct calls for all the built-in expressions. ~15% improvement in pathological cases. checkpatch doesn't like the X macro due to the embedded return statement, but the macro has a very limited scope so I don't think its a problem. I would like to avoid bugs of the form If (e->ops->eval == (unsigned long)nft_foo_eval) nft_bar_eval(); and open-coded if ()/else if()/else cascade, thus the macro. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
145 lines
3.6 KiB
C
145 lines
3.6 KiB
C
/*
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* Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
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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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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.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_core.h>
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#include <net/netfilter/nf_tables.h>
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struct nft_range_expr {
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struct nft_data data_from;
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struct nft_data data_to;
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enum nft_registers sreg:8;
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u8 len;
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enum nft_range_ops op:8;
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};
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void nft_range_eval(const struct nft_expr *expr,
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struct nft_regs *regs, const struct nft_pktinfo *pkt)
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{
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const struct nft_range_expr *priv = nft_expr_priv(expr);
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int d1, d2;
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d1 = memcmp(®s->data[priv->sreg], &priv->data_from, priv->len);
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d2 = memcmp(®s->data[priv->sreg], &priv->data_to, priv->len);
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switch (priv->op) {
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case NFT_RANGE_EQ:
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if (d1 < 0 || d2 > 0)
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regs->verdict.code = NFT_BREAK;
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break;
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case NFT_RANGE_NEQ:
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if (d1 >= 0 && d2 <= 0)
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regs->verdict.code = NFT_BREAK;
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break;
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}
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}
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static const struct nla_policy nft_range_policy[NFTA_RANGE_MAX + 1] = {
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[NFTA_RANGE_SREG] = { .type = NLA_U32 },
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[NFTA_RANGE_OP] = { .type = NLA_U32 },
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[NFTA_RANGE_FROM_DATA] = { .type = NLA_NESTED },
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[NFTA_RANGE_TO_DATA] = { .type = NLA_NESTED },
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};
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static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_range_expr *priv = nft_expr_priv(expr);
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struct nft_data_desc desc_from, desc_to;
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int err;
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u32 op;
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if (!tb[NFTA_RANGE_SREG] ||
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!tb[NFTA_RANGE_OP] ||
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!tb[NFTA_RANGE_FROM_DATA] ||
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!tb[NFTA_RANGE_TO_DATA])
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return -EINVAL;
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err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from),
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&desc_from, tb[NFTA_RANGE_FROM_DATA]);
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if (err < 0)
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return err;
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err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to),
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&desc_to, tb[NFTA_RANGE_TO_DATA]);
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if (err < 0)
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goto err1;
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if (desc_from.len != desc_to.len) {
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err = -EINVAL;
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goto err2;
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}
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priv->sreg = nft_parse_register(tb[NFTA_RANGE_SREG]);
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err = nft_validate_register_load(priv->sreg, desc_from.len);
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if (err < 0)
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goto err2;
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err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op);
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if (err < 0)
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goto err2;
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switch (op) {
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case NFT_RANGE_EQ:
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case NFT_RANGE_NEQ:
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break;
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default:
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err = -EINVAL;
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goto err2;
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}
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priv->op = op;
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priv->len = desc_from.len;
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return 0;
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err2:
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nft_data_release(&priv->data_to, desc_to.type);
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err1:
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nft_data_release(&priv->data_from, desc_from.type);
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return err;
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}
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static int nft_range_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_range_expr *priv = nft_expr_priv(expr);
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if (nft_dump_register(skb, NFTA_RANGE_SREG, priv->sreg))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_RANGE_OP, htonl(priv->op)))
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goto nla_put_failure;
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if (nft_data_dump(skb, NFTA_RANGE_FROM_DATA, &priv->data_from,
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NFT_DATA_VALUE, priv->len) < 0 ||
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nft_data_dump(skb, NFTA_RANGE_TO_DATA, &priv->data_to,
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NFT_DATA_VALUE, priv->len) < 0)
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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 const struct nft_expr_ops nft_range_ops = {
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.type = &nft_range_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)),
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.eval = nft_range_eval,
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.init = nft_range_init,
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.dump = nft_range_dump,
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};
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struct nft_expr_type nft_range_type __read_mostly = {
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.name = "range",
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.ops = &nft_range_ops,
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.policy = nft_range_policy,
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.maxattr = NFTA_RANGE_MAX,
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.owner = THIS_MODULE,
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};
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