| // 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; |
| u8 sreg; |
| 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 = { |
| .type = NFT_DATA_VALUE, |
| .size = sizeof(priv->data), |
| }; |
| int err; |
| |
| err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); |
| if (err < 0) |
| return err; |
| |
| err = nft_parse_register_load(tb[NFTA_CMP_SREG], &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, bool reset) |
| { |
| 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(*((__be16 *)val)); |
| break; |
| case 4: |
| data->val32 = ntohl(*((__be32 *)val)); |
| break; |
| case 8: |
| data->val64 = be64_to_cpu(*((__be64 *)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, |
| .reduce = NFT_REDUCE_READONLY, |
| .offload = nft_cmp_offload, |
| }; |
| |
| /* Calculate the mask for the nft_cmp_fast expression. On big endian the |
| * mask needs to include the *upper* bytes when interpreting that data as |
| * something smaller than the full u32, therefore a cpu_to_le32 is done. |
| */ |
| static u32 nft_cmp_fast_mask(unsigned int len) |
| { |
| __le32 mask = cpu_to_le32(~0U >> (sizeof_field(struct nft_cmp_fast_expr, |
| data) * BITS_PER_BYTE - len)); |
| |
| return (__force u32)mask; |
| } |
| |
| 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 data; |
| struct nft_data_desc desc = { |
| .type = NFT_DATA_VALUE, |
| .size = sizeof(data), |
| }; |
| int err; |
| |
| err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); |
| if (err < 0) |
| return err; |
| |
| err = nft_parse_register_load(tb[NFTA_CMP_SREG], &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, bool reset) |
| { |
| 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, |
| .reduce = NFT_REDUCE_READONLY, |
| .offload = nft_cmp_fast_offload, |
| }; |
| |
| static u32 nft_cmp_mask(u32 bitlen) |
| { |
| return (__force u32)cpu_to_le32(~0U >> (sizeof(u32) * BITS_PER_BYTE - bitlen)); |
| } |
| |
| static void nft_cmp16_fast_mask(struct nft_data *data, unsigned int bitlen) |
| { |
| int len = bitlen / BITS_PER_BYTE; |
| int i, words = len / sizeof(u32); |
| |
| for (i = 0; i < words; i++) { |
| data->data[i] = 0xffffffff; |
| bitlen -= sizeof(u32) * BITS_PER_BYTE; |
| } |
| |
| if (len % sizeof(u32)) |
| data->data[i++] = nft_cmp_mask(bitlen); |
| |
| for (; i < 4; i++) |
| data->data[i] = 0; |
| } |
| |
| static int nft_cmp16_fast_init(const struct nft_ctx *ctx, |
| const struct nft_expr *expr, |
| const struct nlattr * const tb[]) |
| { |
| struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); |
| struct nft_data_desc desc = { |
| .type = NFT_DATA_VALUE, |
| .size = sizeof(priv->data), |
| }; |
| int err; |
| |
| err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); |
| if (err < 0) |
| return err; |
| |
| err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); |
| if (err < 0) |
| return err; |
| |
| nft_cmp16_fast_mask(&priv->mask, desc.len * BITS_PER_BYTE); |
| priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ; |
| priv->len = desc.len; |
| |
| return 0; |
| } |
| |
| static int nft_cmp16_fast_offload(struct nft_offload_ctx *ctx, |
| struct nft_flow_rule *flow, |
| const struct nft_expr *expr) |
| { |
| const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); |
| struct nft_cmp_expr cmp = { |
| .data = priv->data, |
| .sreg = priv->sreg, |
| .len = priv->len, |
| .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ, |
| }; |
| |
| return __nft_cmp_offload(ctx, flow, &cmp); |
| } |
| |
| static int nft_cmp16_fast_dump(struct sk_buff *skb, |
| const struct nft_expr *expr, bool reset) |
| { |
| const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); |
| enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ; |
| |
| 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; |
| |
| 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; |
| } |
| |
| |
| const struct nft_expr_ops nft_cmp16_fast_ops = { |
| .type = &nft_cmp_type, |
| .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp16_fast_expr)), |
| .eval = NULL, /* inlined */ |
| .init = nft_cmp16_fast_init, |
| .dump = nft_cmp16_fast_dump, |
| .reduce = NFT_REDUCE_READONLY, |
| .offload = nft_cmp16_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 data; |
| struct nft_data_desc desc = { |
| .type = NFT_DATA_VALUE, |
| .size = sizeof(data), |
| }; |
| enum nft_cmp_ops op; |
| u8 sreg; |
| 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, &desc, tb[NFTA_CMP_DATA]); |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); |
| |
| if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) { |
| if (desc.len <= sizeof(u32)) |
| return &nft_cmp_fast_ops; |
| else if (desc.len <= sizeof(data) && |
| ((sreg >= NFT_REG_1 && sreg <= NFT_REG_4) || |
| (sreg >= NFT_REG32_00 && sreg <= NFT_REG32_12 && sreg % 2 == 0))) |
| return &nft_cmp16_fast_ops; |
| } |
| return &nft_cmp_ops; |
| } |
| |
| 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, |
| }; |
