https://github.com/torvalds/linux
Tip revision: 2241ab53cbb5cdb08a6b2d4688feb13971058f65 authored by Linus Torvalds on 22 January 2023, 00:27:01 UTC
Linux 6.2-rc5
Linux 6.2-rc5
Tip revision: 2241ab5
nft_bitwise.c
// 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/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_offload.h>
struct nft_bitwise {
u8 sreg;
u8 dreg;
enum nft_bitwise_ops op:8;
u8 len;
struct nft_data mask;
struct nft_data xor;
struct nft_data data;
};
static void nft_bitwise_eval_bool(u32 *dst, const u32 *src,
const struct nft_bitwise *priv)
{
unsigned int i;
for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++)
dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i];
}
static void nft_bitwise_eval_lshift(u32 *dst, const u32 *src,
const struct nft_bitwise *priv)
{
u32 shift = priv->data.data[0];
unsigned int i;
u32 carry = 0;
for (i = DIV_ROUND_UP(priv->len, sizeof(u32)); i > 0; i--) {
dst[i - 1] = (src[i - 1] << shift) | carry;
carry = src[i - 1] >> (BITS_PER_TYPE(u32) - shift);
}
}
static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src,
const struct nft_bitwise *priv)
{
u32 shift = priv->data.data[0];
unsigned int i;
u32 carry = 0;
for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) {
dst[i] = carry | (src[i] >> shift);
carry = src[i] << (BITS_PER_TYPE(u32) - shift);
}
}
void nft_bitwise_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
const u32 *src = ®s->data[priv->sreg];
u32 *dst = ®s->data[priv->dreg];
switch (priv->op) {
case NFT_BITWISE_BOOL:
nft_bitwise_eval_bool(dst, src, priv);
break;
case NFT_BITWISE_LSHIFT:
nft_bitwise_eval_lshift(dst, src, priv);
break;
case NFT_BITWISE_RSHIFT:
nft_bitwise_eval_rshift(dst, src, priv);
break;
}
}
static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
[NFTA_BITWISE_SREG] = { .type = NLA_U32 },
[NFTA_BITWISE_DREG] = { .type = NLA_U32 },
[NFTA_BITWISE_LEN] = { .type = NLA_U32 },
[NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
[NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
[NFTA_BITWISE_OP] = { .type = NLA_U32 },
[NFTA_BITWISE_DATA] = { .type = NLA_NESTED },
};
static int nft_bitwise_init_bool(struct nft_bitwise *priv,
const struct nlattr *const tb[])
{
struct nft_data_desc mask = {
.type = NFT_DATA_VALUE,
.size = sizeof(priv->mask),
.len = priv->len,
};
struct nft_data_desc xor = {
.type = NFT_DATA_VALUE,
.size = sizeof(priv->xor),
.len = priv->len,
};
int err;
if (tb[NFTA_BITWISE_DATA])
return -EINVAL;
if (!tb[NFTA_BITWISE_MASK] ||
!tb[NFTA_BITWISE_XOR])
return -EINVAL;
err = nft_data_init(NULL, &priv->mask, &mask, tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
err = nft_data_init(NULL, &priv->xor, &xor, tb[NFTA_BITWISE_XOR]);
if (err < 0)
goto err_xor_err;
return 0;
err_xor_err:
nft_data_release(&priv->mask, mask.type);
return err;
}
static int nft_bitwise_init_shift(struct nft_bitwise *priv,
const struct nlattr *const tb[])
{
struct nft_data_desc desc = {
.type = NFT_DATA_VALUE,
.size = sizeof(priv->data),
.len = sizeof(u32),
};
int err;
if (tb[NFTA_BITWISE_MASK] ||
tb[NFTA_BITWISE_XOR])
return -EINVAL;
if (!tb[NFTA_BITWISE_DATA])
return -EINVAL;
err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_BITWISE_DATA]);
if (err < 0)
return err;
if (priv->data.data[0] >= BITS_PER_TYPE(u32)) {
nft_data_release(&priv->data, desc.type);
return -EINVAL;
}
return 0;
}
static int nft_bitwise_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_bitwise *priv = nft_expr_priv(expr);
u32 len;
int err;
err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
if (err < 0)
return err;
priv->len = len;
err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg,
priv->len);
if (err < 0)
return err;
err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG],
&priv->dreg, NULL, NFT_DATA_VALUE,
priv->len);
if (err < 0)
return err;
if (tb[NFTA_BITWISE_OP]) {
priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP]));
switch (priv->op) {
case NFT_BITWISE_BOOL:
case NFT_BITWISE_LSHIFT:
case NFT_BITWISE_RSHIFT:
break;
default:
return -EOPNOTSUPP;
}
} else {
priv->op = NFT_BITWISE_BOOL;
}
switch(priv->op) {
case NFT_BITWISE_BOOL:
err = nft_bitwise_init_bool(priv, tb);
break;
case NFT_BITWISE_LSHIFT:
case NFT_BITWISE_RSHIFT:
err = nft_bitwise_init_shift(priv, tb);
break;
}
return err;
}
static int nft_bitwise_dump_bool(struct sk_buff *skb,
const struct nft_bitwise *priv)
{
if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
NFT_DATA_VALUE, priv->len) < 0)
return -1;
if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
NFT_DATA_VALUE, priv->len) < 0)
return -1;
return 0;
}
static int nft_bitwise_dump_shift(struct sk_buff *skb,
const struct nft_bitwise *priv)
{
if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data,
NFT_DATA_VALUE, sizeof(u32)) < 0)
return -1;
return 0;
}
static int nft_bitwise_dump(struct sk_buff *skb,
const struct nft_expr *expr, bool reset)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
int err = 0;
if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
return -1;
if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
return -1;
if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
return -1;
if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op)))
return -1;
switch (priv->op) {
case NFT_BITWISE_BOOL:
err = nft_bitwise_dump_bool(skb, priv);
break;
case NFT_BITWISE_LSHIFT:
case NFT_BITWISE_RSHIFT:
err = nft_bitwise_dump_shift(skb, priv);
break;
}
return err;
}
static struct nft_data zero;
static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
struct nft_flow_rule *flow,
const struct nft_expr *expr)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
if (priv->op != NFT_BITWISE_BOOL)
return -EOPNOTSUPP;
if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) ||
priv->sreg != priv->dreg || priv->len != reg->len)
return -EOPNOTSUPP;
memcpy(®->mask, &priv->mask, sizeof(priv->mask));
return 0;
}
static bool nft_bitwise_reduce(struct nft_regs_track *track,
const struct nft_expr *expr)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
const struct nft_bitwise *bitwise;
unsigned int regcount;
u8 dreg;
int i;
if (!track->regs[priv->sreg].selector)
return false;
bitwise = nft_expr_priv(track->regs[priv->dreg].selector);
if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
track->regs[priv->sreg].num_reg == 0 &&
track->regs[priv->dreg].bitwise &&
track->regs[priv->dreg].bitwise->ops == expr->ops &&
priv->sreg == bitwise->sreg &&
priv->dreg == bitwise->dreg &&
priv->op == bitwise->op &&
priv->len == bitwise->len &&
!memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) &&
!memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) &&
!memcmp(&priv->data, &bitwise->data, sizeof(priv->data))) {
track->cur = expr;
return true;
}
if (track->regs[priv->sreg].bitwise ||
track->regs[priv->sreg].num_reg != 0) {
nft_reg_track_cancel(track, priv->dreg, priv->len);
return false;
}
if (priv->sreg != priv->dreg) {
nft_reg_track_update(track, track->regs[priv->sreg].selector,
priv->dreg, priv->len);
}
dreg = priv->dreg;
regcount = DIV_ROUND_UP(priv->len, NFT_REG32_SIZE);
for (i = 0; i < regcount; i++, dreg++)
track->regs[priv->dreg].bitwise = expr;
return false;
}
static const struct nft_expr_ops nft_bitwise_ops = {
.type = &nft_bitwise_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
.eval = nft_bitwise_eval,
.init = nft_bitwise_init,
.dump = nft_bitwise_dump,
.reduce = nft_bitwise_reduce,
.offload = nft_bitwise_offload,
};
static int
nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out)
{
struct nft_data data;
struct nft_data_desc desc = {
.type = NFT_DATA_VALUE,
.size = sizeof(data),
.len = sizeof(u32),
};
int err;
err = nft_data_init(NULL, &data, &desc, tb);
if (err < 0)
return err;
*out = data.data[0];
return 0;
}
static int nft_bitwise_fast_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
int err;
err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg,
sizeof(u32));
if (err < 0)
return err;
err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg,
NULL, NFT_DATA_VALUE, sizeof(u32));
if (err < 0)
return err;
if (tb[NFTA_BITWISE_DATA])
return -EINVAL;
if (!tb[NFTA_BITWISE_MASK] ||
!tb[NFTA_BITWISE_XOR])
return -EINVAL;
err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask);
if (err < 0)
return err;
err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor);
if (err < 0)
return err;
return 0;
}
static int
nft_bitwise_fast_dump(struct sk_buff *skb,
const struct nft_expr *expr, bool reset)
{
const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
struct nft_data data;
if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
return -1;
if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg))
return -1;
if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32))))
return -1;
if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_BOOL)))
return -1;
data.data[0] = priv->mask;
if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data,
NFT_DATA_VALUE, sizeof(u32)) < 0)
return -1;
data.data[0] = priv->xor;
if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data,
NFT_DATA_VALUE, sizeof(u32)) < 0)
return -1;
return 0;
}
static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx,
struct nft_flow_rule *flow,
const struct nft_expr *expr)
{
const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32))
return -EOPNOTSUPP;
reg->mask.data[0] = priv->mask;
return 0;
}
static bool nft_bitwise_fast_reduce(struct nft_regs_track *track,
const struct nft_expr *expr)
{
const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
const struct nft_bitwise_fast_expr *bitwise;
if (!track->regs[priv->sreg].selector)
return false;
bitwise = nft_expr_priv(track->regs[priv->dreg].selector);
if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
track->regs[priv->dreg].bitwise &&
track->regs[priv->dreg].bitwise->ops == expr->ops &&
priv->sreg == bitwise->sreg &&
priv->dreg == bitwise->dreg &&
priv->mask == bitwise->mask &&
priv->xor == bitwise->xor) {
track->cur = expr;
return true;
}
if (track->regs[priv->sreg].bitwise) {
nft_reg_track_cancel(track, priv->dreg, NFT_REG32_SIZE);
return false;
}
if (priv->sreg != priv->dreg) {
track->regs[priv->dreg].selector =
track->regs[priv->sreg].selector;
}
track->regs[priv->dreg].bitwise = expr;
return false;
}
const struct nft_expr_ops nft_bitwise_fast_ops = {
.type = &nft_bitwise_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)),
.eval = NULL, /* inlined */
.init = nft_bitwise_fast_init,
.dump = nft_bitwise_fast_dump,
.reduce = nft_bitwise_fast_reduce,
.offload = nft_bitwise_fast_offload,
};
static const struct nft_expr_ops *
nft_bitwise_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
int err;
u32 len;
if (!tb[NFTA_BITWISE_LEN] ||
!tb[NFTA_BITWISE_SREG] ||
!tb[NFTA_BITWISE_DREG])
return ERR_PTR(-EINVAL);
err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
if (err < 0)
return ERR_PTR(err);
if (len != sizeof(u32))
return &nft_bitwise_ops;
if (tb[NFTA_BITWISE_OP] &&
ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_BOOL)
return &nft_bitwise_ops;
return &nft_bitwise_fast_ops;
}
struct nft_expr_type nft_bitwise_type __read_mostly = {
.name = "bitwise",
.select_ops = nft_bitwise_select_ops,
.policy = nft_bitwise_policy,
.maxattr = NFTA_BITWISE_MAX,
.owner = THIS_MODULE,
};
bool nft_expr_reduce_bitwise(struct nft_regs_track *track,
const struct nft_expr *expr)
{
const struct nft_expr *last = track->last;
const struct nft_expr *next;
if (expr == last)
return false;
next = nft_expr_next(expr);
if (next->ops == &nft_bitwise_ops)
return nft_bitwise_reduce(track, next);
else if (next->ops == &nft_bitwise_fast_ops)
return nft_bitwise_fast_reduce(track, next);
return false;
}
EXPORT_SYMBOL_GPL(nft_expr_reduce_bitwise);