// 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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u8 sreg;
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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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.type = NFT_DATA_VALUE,
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.size = sizeof(priv->data),
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};
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int err;
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err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);
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if (err < 0)
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return err;
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err = nft_parse_register_load(tb[NFTA_CMP_SREG], &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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union nft_cmp_offload_data {
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u16 val16;
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u32 val32;
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u64 val64;
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};
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static void nft_payload_n2h(union nft_cmp_offload_data *data,
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const u8 *val, u32 len)
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{
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switch (len) {
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case 2:
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data->val16 = ntohs(*((u16 *)val));
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break;
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case 4:
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data->val32 = ntohl(*((u32 *)val));
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break;
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case 8:
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data->val64 = be64_to_cpu(*((u64 *)val));
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break;
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default:
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WARN_ON_ONCE(1);
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break;
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}
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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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union nft_cmp_offload_data _data, _datamask;
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u8 *mask = (u8 *)&flow->match.mask;
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u8 *key = (u8 *)&flow->match.key;
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u8 *data, *datamask;
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if (priv->op != NFT_CMP_EQ || priv->len > reg->len)
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return -EOPNOTSUPP;
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if (reg->flags & NFT_OFFLOAD_F_NETWORK2HOST) {
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nft_payload_n2h(&_data, (u8 *)&priv->data, reg->len);
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nft_payload_n2h(&_datamask, (u8 *)®->mask, reg->len);
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data = (u8 *)&_data;
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datamask = (u8 *)&_datamask;
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} else {
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data = (u8 *)&priv->data;
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datamask = (u8 *)®->mask;
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}
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memcpy(key + reg->offset, data, reg->len);
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memcpy(mask + reg->offset, datamask, 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 data;
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struct nft_data_desc desc = {
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.type = NFT_DATA_VALUE,
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.size = sizeof(data),
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};
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int err;
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err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
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if (err < 0)
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return err;
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err = nft_parse_register_load(tb[NFTA_CMP_SREG], &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 u32 nft_cmp_mask(u32 bitlen)
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{
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return (__force u32)cpu_to_le32(~0U >> (sizeof(u32) * BITS_PER_BYTE - bitlen));
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}
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static void nft_cmp16_fast_mask(struct nft_data *data, unsigned int bitlen)
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{
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int len = bitlen / BITS_PER_BYTE;
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int i, words = len / sizeof(u32);
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for (i = 0; i < words; i++) {
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data->data[i] = 0xffffffff;
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bitlen -= sizeof(u32) * BITS_PER_BYTE;
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}
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if (len % sizeof(u32))
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data->data[i++] = nft_cmp_mask(bitlen);
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for (; i < 4; i++)
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data->data[i] = 0;
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}
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static int nft_cmp16_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_cmp16_fast_expr *priv = nft_expr_priv(expr);
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struct nft_data_desc desc = {
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.type = NFT_DATA_VALUE,
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.size = sizeof(priv->data),
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};
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int err;
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err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);
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if (err < 0)
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return err;
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err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len);
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if (err < 0)
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return err;
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nft_cmp16_fast_mask(&priv->mask, desc.len * BITS_PER_BYTE);
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priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;
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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_cmp16_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_cmp16_fast_expr *priv = nft_expr_priv(expr);
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struct nft_cmp_expr cmp = {
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.data = priv->data,
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.sreg = priv->sreg,
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.len = priv->len,
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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_cmp16_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_cmp16_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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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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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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const struct nft_expr_ops nft_cmp16_fast_ops = {
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.type = &nft_cmp_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_cmp16_fast_expr)),
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.eval = NULL, /* inlined */
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.init = nft_cmp16_fast_init,
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.dump = nft_cmp16_fast_dump,
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.offload = nft_cmp16_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 data;
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struct nft_data_desc desc = {
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.type = NFT_DATA_VALUE,
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.size = sizeof(data),
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};
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enum nft_cmp_ops op;
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u8 sreg;
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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, &desc, tb[NFTA_CMP_DATA]);
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if (err < 0)
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return ERR_PTR(err);
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sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG]));
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if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) {
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if (desc.len <= sizeof(u32))
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return &nft_cmp_fast_ops;
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else if (desc.len <= sizeof(data) &&
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((sreg >= NFT_REG_1 && sreg <= NFT_REG_4) ||
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(sreg >= NFT_REG32_00 && sreg <= NFT_REG32_12 && sreg % 2 == 0)))
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return &nft_cmp16_fast_ops;
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}
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return &nft_cmp_ops;
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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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