a5d45bc0dc
Userspace might match on prefix bytes of header fields if they are on
the byte boundary, this requires that the mask is adjusted accordingly.
Use NFT_OFFLOAD_MATCH_EXACT() for meta since prefix byte matching is not
allowed for this type of selector.
The bitwise expression might be optimized out by userspace, hence the
kernel needs to infer the prefix from the number of payload bytes to
match on. This patch adds nft_payload_offload_mask() to calculate the
bitmask to match on the prefix.
Fixes: c9626a2cbd ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
292 lines
6.9 KiB
C
292 lines
6.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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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/if_arp.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_offload.h>
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#include <net/netfilter/nf_tables.h>
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struct nft_cmp_expr {
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struct nft_data data;
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enum nft_registers sreg:8;
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u8 len;
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enum nft_cmp_ops op:8;
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};
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void nft_cmp_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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const struct nft_cmp_expr *priv = nft_expr_priv(expr);
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int d;
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d = memcmp(®s->data[priv->sreg], &priv->data, priv->len);
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switch (priv->op) {
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case NFT_CMP_EQ:
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if (d != 0)
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goto mismatch;
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break;
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case NFT_CMP_NEQ:
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if (d == 0)
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goto mismatch;
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break;
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case NFT_CMP_LT:
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if (d == 0)
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goto mismatch;
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fallthrough;
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case NFT_CMP_LTE:
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if (d > 0)
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goto mismatch;
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break;
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case NFT_CMP_GT:
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if (d == 0)
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goto mismatch;
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fallthrough;
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case NFT_CMP_GTE:
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if (d < 0)
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goto mismatch;
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break;
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}
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return;
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mismatch:
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regs->verdict.code = NFT_BREAK;
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}
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static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
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[NFTA_CMP_SREG] = { .type = NLA_U32 },
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[NFTA_CMP_OP] = { .type = NLA_U32 },
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[NFTA_CMP_DATA] = { .type = NLA_NESTED },
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};
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static int nft_cmp_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_cmp_expr *priv = nft_expr_priv(expr);
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struct nft_data_desc desc;
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int err;
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err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
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tb[NFTA_CMP_DATA]);
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if (err < 0)
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return err;
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if (desc.type != NFT_DATA_VALUE) {
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err = -EINVAL;
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nft_data_release(&priv->data, desc.type);
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return err;
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}
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priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
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err = nft_validate_register_load(priv->sreg, desc.len);
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if (err < 0)
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return err;
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priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
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priv->len = desc.len;
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return 0;
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}
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static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_cmp_expr *priv = nft_expr_priv(expr);
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if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
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goto nla_put_failure;
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if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
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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 int __nft_cmp_offload(struct nft_offload_ctx *ctx,
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struct nft_flow_rule *flow,
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const struct nft_cmp_expr *priv)
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{
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struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
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u8 *mask = (u8 *)&flow->match.mask;
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u8 *key = (u8 *)&flow->match.key;
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if (priv->op != NFT_CMP_EQ || priv->len > reg->len)
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return -EOPNOTSUPP;
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memcpy(key + reg->offset, &priv->data, reg->len);
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memcpy(mask + reg->offset, ®->mask, reg->len);
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flow->match.dissector.used_keys |= BIT(reg->key);
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flow->match.dissector.offset[reg->key] = reg->base_offset;
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if (reg->key == FLOW_DISSECTOR_KEY_META &&
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reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&
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nft_reg_load16(priv->data.data) != ARPHRD_ETHER)
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return -EOPNOTSUPP;
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nft_offload_update_dependency(ctx, &priv->data, reg->len);
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return 0;
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}
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static int nft_cmp_offload(struct nft_offload_ctx *ctx,
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struct nft_flow_rule *flow,
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const struct nft_expr *expr)
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{
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const struct nft_cmp_expr *priv = nft_expr_priv(expr);
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return __nft_cmp_offload(ctx, flow, priv);
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}
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static const struct nft_expr_ops nft_cmp_ops = {
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.type = &nft_cmp_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
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.eval = nft_cmp_eval,
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.init = nft_cmp_init,
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.dump = nft_cmp_dump,
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.offload = nft_cmp_offload,
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};
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static int nft_cmp_fast_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_cmp_fast_expr *priv = nft_expr_priv(expr);
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struct nft_data_desc desc;
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struct nft_data data;
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int err;
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err = nft_data_init(NULL, &data, sizeof(data), &desc,
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tb[NFTA_CMP_DATA]);
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if (err < 0)
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return err;
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priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
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err = nft_validate_register_load(priv->sreg, desc.len);
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if (err < 0)
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return err;
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desc.len *= BITS_PER_BYTE;
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priv->mask = nft_cmp_fast_mask(desc.len);
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priv->data = data.data[0] & priv->mask;
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priv->len = desc.len;
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priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;
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return 0;
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}
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static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,
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struct nft_flow_rule *flow,
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const struct nft_expr *expr)
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{
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const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
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struct nft_cmp_expr cmp = {
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.data = {
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.data = {
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[0] = priv->data,
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},
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},
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.sreg = priv->sreg,
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.len = priv->len / BITS_PER_BYTE,
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.op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,
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};
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return __nft_cmp_offload(ctx, flow, &cmp);
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}
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static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
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enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ;
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struct nft_data data;
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if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))
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goto nla_put_failure;
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data.data[0] = priv->data;
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if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
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NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 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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const struct nft_expr_ops nft_cmp_fast_ops = {
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.type = &nft_cmp_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
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.eval = NULL, /* inlined */
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.init = nft_cmp_fast_init,
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.dump = nft_cmp_fast_dump,
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.offload = nft_cmp_fast_offload,
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};
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static const struct nft_expr_ops *
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nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
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{
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struct nft_data_desc desc;
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struct nft_data data;
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enum nft_cmp_ops op;
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int err;
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if (tb[NFTA_CMP_SREG] == NULL ||
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tb[NFTA_CMP_OP] == NULL ||
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tb[NFTA_CMP_DATA] == NULL)
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return ERR_PTR(-EINVAL);
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op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
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switch (op) {
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case NFT_CMP_EQ:
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case NFT_CMP_NEQ:
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case NFT_CMP_LT:
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case NFT_CMP_LTE:
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case NFT_CMP_GT:
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case NFT_CMP_GTE:
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break;
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default:
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return ERR_PTR(-EINVAL);
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}
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err = nft_data_init(NULL, &data, sizeof(data), &desc,
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tb[NFTA_CMP_DATA]);
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if (err < 0)
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return ERR_PTR(err);
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if (desc.type != NFT_DATA_VALUE) {
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err = -EINVAL;
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goto err1;
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}
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if (desc.len <= sizeof(u32) && (op == NFT_CMP_EQ || op == NFT_CMP_NEQ))
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return &nft_cmp_fast_ops;
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return &nft_cmp_ops;
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err1:
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nft_data_release(&data, desc.type);
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return ERR_PTR(-EINVAL);
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}
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struct nft_expr_type nft_cmp_type __read_mostly = {
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.name = "cmp",
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.select_ops = nft_cmp_select_ops,
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.policy = nft_cmp_policy,
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.maxattr = NFTA_CMP_MAX,
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.owner = THIS_MODULE,
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};
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