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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
- *
- * Development of this code funded by Astaro AG (http://www.astaro.com/)
- */
- #include <linux/kernel.h>
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/netlink.h>
- #include <linux/netfilter.h>
- #include <linux/if_arp.h>
- #include <linux/netfilter/nf_tables.h>
- #include <net/netfilter/nf_tables_core.h>
- #include <net/netfilter/nf_tables_offload.h>
- #include <net/netfilter/nf_tables.h>
- struct nft_cmp_expr {
- struct nft_data data;
- enum nft_registers sreg:8;
- u8 len;
- enum nft_cmp_ops op:8;
- };
- void nft_cmp_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_pktinfo *pkt)
- {
- const struct nft_cmp_expr *priv = nft_expr_priv(expr);
- int d;
- d = memcmp(®s->data[priv->sreg], &priv->data, priv->len);
- switch (priv->op) {
- case NFT_CMP_EQ:
- if (d != 0)
- goto mismatch;
- break;
- case NFT_CMP_NEQ:
- if (d == 0)
- goto mismatch;
- break;
- case NFT_CMP_LT:
- if (d == 0)
- goto mismatch;
- fallthrough;
- case NFT_CMP_LTE:
- if (d > 0)
- goto mismatch;
- break;
- case NFT_CMP_GT:
- if (d == 0)
- goto mismatch;
- fallthrough;
- case NFT_CMP_GTE:
- if (d < 0)
- goto mismatch;
- break;
- }
- return;
- mismatch:
- regs->verdict.code = NFT_BREAK;
- }
- static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
- [NFTA_CMP_SREG] = { .type = NLA_U32 },
- [NFTA_CMP_OP] = { .type = NLA_U32 },
- [NFTA_CMP_DATA] = { .type = NLA_NESTED },
- };
- static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
- const struct nlattr * const tb[])
- {
- struct nft_cmp_expr *priv = nft_expr_priv(expr);
- struct nft_data_desc desc;
- int err;
- err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
- tb[NFTA_CMP_DATA]);
- if (err < 0)
- return err;
- if (desc.type != NFT_DATA_VALUE) {
- err = -EINVAL;
- nft_data_release(&priv->data, desc.type);
- return err;
- }
- priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
- err = nft_validate_register_load(priv->sreg, desc.len);
- if (err < 0)
- return err;
- priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
- priv->len = desc.len;
- return 0;
- }
- static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
- {
- const struct nft_cmp_expr *priv = nft_expr_priv(expr);
- if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
- goto nla_put_failure;
- if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
- goto nla_put_failure;
- if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
- NFT_DATA_VALUE, priv->len) < 0)
- goto nla_put_failure;
- return 0;
- nla_put_failure:
- return -1;
- }
- union nft_cmp_offload_data {
- u16 val16;
- u32 val32;
- u64 val64;
- };
- static void nft_payload_n2h(union nft_cmp_offload_data *data,
- const u8 *val, u32 len)
- {
- switch (len) {
- case 2:
- data->val16 = ntohs(*((u16 *)val));
- break;
- case 4:
- data->val32 = ntohl(*((u32 *)val));
- break;
- case 8:
- data->val64 = be64_to_cpu(*((u64 *)val));
- break;
- default:
- WARN_ON_ONCE(1);
- break;
- }
- }
- static int __nft_cmp_offload(struct nft_offload_ctx *ctx,
- struct nft_flow_rule *flow,
- const struct nft_cmp_expr *priv)
- {
- struct nft_offload_reg *reg = &ctx->regs[priv->sreg];
- union nft_cmp_offload_data _data, _datamask;
- u8 *mask = (u8 *)&flow->match.mask;
- u8 *key = (u8 *)&flow->match.key;
- u8 *data, *datamask;
- if (priv->op != NFT_CMP_EQ || priv->len > reg->len)
- return -EOPNOTSUPP;
- if (reg->flags & NFT_OFFLOAD_F_NETWORK2HOST) {
- nft_payload_n2h(&_data, (u8 *)&priv->data, reg->len);
- nft_payload_n2h(&_datamask, (u8 *)®->mask, reg->len);
- data = (u8 *)&_data;
- datamask = (u8 *)&_datamask;
- } else {
- data = (u8 *)&priv->data;
- datamask = (u8 *)®->mask;
- }
- memcpy(key + reg->offset, data, reg->len);
- memcpy(mask + reg->offset, datamask, reg->len);
- flow->match.dissector.used_keys |= BIT(reg->key);
- flow->match.dissector.offset[reg->key] = reg->base_offset;
- if (reg->key == FLOW_DISSECTOR_KEY_META &&
- reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) &&
- nft_reg_load16(priv->data.data) != ARPHRD_ETHER)
- return -EOPNOTSUPP;
- nft_offload_update_dependency(ctx, &priv->data, reg->len);
- return 0;
- }
- static int nft_cmp_offload(struct nft_offload_ctx *ctx,
- struct nft_flow_rule *flow,
- const struct nft_expr *expr)
- {
- const struct nft_cmp_expr *priv = nft_expr_priv(expr);
- return __nft_cmp_offload(ctx, flow, priv);
- }
- static const struct nft_expr_ops nft_cmp_ops = {
- .type = &nft_cmp_type,
- .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
- .eval = nft_cmp_eval,
- .init = nft_cmp_init,
- .dump = nft_cmp_dump,
- .offload = nft_cmp_offload,
- };
- static int nft_cmp_fast_init(const struct nft_ctx *ctx,
- const struct nft_expr *expr,
- const struct nlattr * const tb[])
- {
- struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
- struct nft_data_desc desc;
- struct nft_data data;
- int err;
- err = nft_data_init(NULL, &data, sizeof(data), &desc,
- tb[NFTA_CMP_DATA]);
- if (err < 0)
- return err;
- priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
- err = nft_validate_register_load(priv->sreg, desc.len);
- if (err < 0)
- return err;
- desc.len *= BITS_PER_BYTE;
- priv->mask = nft_cmp_fast_mask(desc.len);
- priv->data = data.data[0] & priv->mask;
- priv->len = desc.len;
- priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ;
- return 0;
- }
- static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx,
- struct nft_flow_rule *flow,
- const struct nft_expr *expr)
- {
- const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
- struct nft_cmp_expr cmp = {
- .data = {
- .data = {
- [0] = priv->data,
- },
- },
- .sreg = priv->sreg,
- .len = priv->len / BITS_PER_BYTE,
- .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ,
- };
- return __nft_cmp_offload(ctx, flow, &cmp);
- }
- static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
- {
- const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
- enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ;
- struct nft_data data;
- if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
- goto nla_put_failure;
- if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op)))
- goto nla_put_failure;
- data.data[0] = priv->data;
- if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
- NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
- goto nla_put_failure;
- return 0;
- nla_put_failure:
- return -1;
- }
- const struct nft_expr_ops nft_cmp_fast_ops = {
- .type = &nft_cmp_type,
- .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
- .eval = NULL, /* inlined */
- .init = nft_cmp_fast_init,
- .dump = nft_cmp_fast_dump,
- .offload = nft_cmp_fast_offload,
- };
- static const struct nft_expr_ops *
- nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
- {
- struct nft_data_desc desc;
- struct nft_data data;
- enum nft_cmp_ops op;
- int err;
- if (tb[NFTA_CMP_SREG] == NULL ||
- tb[NFTA_CMP_OP] == NULL ||
- tb[NFTA_CMP_DATA] == NULL)
- return ERR_PTR(-EINVAL);
- op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
- switch (op) {
- case NFT_CMP_EQ:
- case NFT_CMP_NEQ:
- case NFT_CMP_LT:
- case NFT_CMP_LTE:
- case NFT_CMP_GT:
- case NFT_CMP_GTE:
- break;
- default:
- return ERR_PTR(-EINVAL);
- }
- err = nft_data_init(NULL, &data, sizeof(data), &desc,
- tb[NFTA_CMP_DATA]);
- if (err < 0)
- return ERR_PTR(err);
- if (desc.type != NFT_DATA_VALUE) {
- err = -EINVAL;
- goto err1;
- }
- if (desc.len <= sizeof(u32) && (op == NFT_CMP_EQ || op == NFT_CMP_NEQ))
- return &nft_cmp_fast_ops;
- return &nft_cmp_ops;
- err1:
- nft_data_release(&data, desc.type);
- return ERR_PTR(-EINVAL);
- }
- struct nft_expr_type nft_cmp_type __read_mostly = {
- .name = "cmp",
- .select_ops = nft_cmp_select_ops,
- .policy = nft_cmp_policy,
- .maxattr = NFTA_CMP_MAX,
- .owner = THIS_MODULE,
- };
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