netfilter: nft_xfrm: track register operations

Check if the destination register already contains the data that this
xfrm expression performs. This allows to skip this redundant operation.
If the destination contains a different selector, update the register
tracking information.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2022-03-14 18:23:10 +01:00
parent d77a721d21
commit 48f1910326
1 changed files with 28 additions and 0 deletions

View File

@ -27,6 +27,7 @@ struct nft_xfrm {
u8 dreg;
u8 dir;
u8 spnum;
u8 len;
};
static int nft_xfrm_get_init(const struct nft_ctx *ctx,
@ -86,6 +87,7 @@ static int nft_xfrm_get_init(const struct nft_ctx *ctx,
priv->spnum = spnum;
priv->len = len;
return nft_parse_register_store(ctx, tb[NFTA_XFRM_DREG], &priv->dreg,
NULL, NFT_DATA_VALUE, len);
}
@ -252,6 +254,31 @@ static int nft_xfrm_validate(const struct nft_ctx *ctx, const struct nft_expr *e
return nft_chain_validate_hooks(ctx->chain, hooks);
}
static bool nft_xfrm_reduce(struct nft_regs_track *track,
const struct nft_expr *expr)
{
const struct nft_xfrm *priv = nft_expr_priv(expr);
const struct nft_xfrm *xfrm;
if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
nft_reg_track_update(track, expr, priv->dreg, priv->len);
return false;
}
xfrm = nft_expr_priv(track->regs[priv->dreg].selector);
if (priv->key != xfrm->key ||
priv->dreg != xfrm->dreg ||
priv->dir != xfrm->dir ||
priv->spnum != xfrm->spnum) {
nft_reg_track_update(track, expr, priv->dreg, priv->len);
return false;
}
if (!track->regs[priv->dreg].bitwise)
return true;
return nft_expr_reduce_bitwise(track, expr);
}
static struct nft_expr_type nft_xfrm_type;
static const struct nft_expr_ops nft_xfrm_get_ops = {
@ -261,6 +288,7 @@ static const struct nft_expr_ops nft_xfrm_get_ops = {
.init = nft_xfrm_get_init,
.dump = nft_xfrm_get_dump,
.validate = nft_xfrm_validate,
.reduce = nft_xfrm_reduce,
};
static struct nft_expr_type nft_xfrm_type __read_mostly = {