blob: 6eb21a4f5698921ee73487b14a6d0097d5e053af [file] [log] [blame]
// 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(&regs->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 *)&reg->mask, reg->len);
data = (u8 *)&_data;
datamask = (u8 *)&_datamask;
} else {
data = (u8 *)&priv->data;
datamask = (u8 *)&reg->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,
};