![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>
147 lines
3.8 KiB
C
147 lines
3.8 KiB
C
/*
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* Copyright (c) 2008-2009 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/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_bitwise {
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enum nft_registers sreg:8;
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enum nft_registers dreg:8;
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u8 len;
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struct nft_data mask;
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struct nft_data xor;
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};
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void nft_bitwise_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_bitwise *priv = nft_expr_priv(expr);
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const u32 *src = ®s->data[priv->sreg];
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u32 *dst = ®s->data[priv->dreg];
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unsigned int i;
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for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++)
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dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
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}
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static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
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[NFTA_BITWISE_SREG] = { .type = NLA_U32 },
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[NFTA_BITWISE_DREG] = { .type = NLA_U32 },
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[NFTA_BITWISE_LEN] = { .type = NLA_U32 },
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[NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
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[NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
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};
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static int nft_bitwise_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_bitwise *priv = nft_expr_priv(expr);
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struct nft_data_desc d1, d2;
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u32 len;
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int err;
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if (tb[NFTA_BITWISE_SREG] == NULL ||
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tb[NFTA_BITWISE_DREG] == NULL ||
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tb[NFTA_BITWISE_LEN] == NULL ||
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tb[NFTA_BITWISE_MASK] == NULL ||
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tb[NFTA_BITWISE_XOR] == NULL)
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return -EINVAL;
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err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
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if (err < 0)
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return err;
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priv->len = len;
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priv->sreg = nft_parse_register(tb[NFTA_BITWISE_SREG]);
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err = nft_validate_register_load(priv->sreg, priv->len);
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if (err < 0)
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return err;
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priv->dreg = nft_parse_register(tb[NFTA_BITWISE_DREG]);
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err = nft_validate_register_store(ctx, priv->dreg, NULL,
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NFT_DATA_VALUE, priv->len);
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if (err < 0)
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return err;
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err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
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tb[NFTA_BITWISE_MASK]);
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if (err < 0)
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return err;
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if (d1.len != priv->len) {
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err = -EINVAL;
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goto err1;
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}
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err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
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tb[NFTA_BITWISE_XOR]);
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if (err < 0)
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goto err1;
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if (d2.len != priv->len) {
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err = -EINVAL;
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goto err2;
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}
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return 0;
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err2:
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nft_data_release(&priv->xor, d2.type);
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err1:
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nft_data_release(&priv->mask, d1.type);
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return err;
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}
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static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_bitwise *priv = nft_expr_priv(expr);
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if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
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goto nla_put_failure;
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if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
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goto nla_put_failure;
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if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
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NFT_DATA_VALUE, priv->len) < 0)
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goto nla_put_failure;
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if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
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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_bitwise_ops = {
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.type = &nft_bitwise_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
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.eval = nft_bitwise_eval,
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.init = nft_bitwise_init,
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.dump = nft_bitwise_dump,
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};
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struct nft_expr_type nft_bitwise_type __read_mostly = {
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.name = "bitwise",
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.ops = &nft_bitwise_ops,
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.policy = nft_bitwise_policy,
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.maxattr = NFTA_BITWISE_MAX,
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.owner = THIS_MODULE,
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};
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