netfilter: nft_exthdr: Allow checking TCP option presence, too

Honor NFT_EXTHDR_F_PRESENT flag so we check if the TCP option is
present.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Phil Sutter 2017-02-20 17:52:27 +01:00 committed by Pablo Neira Ayuso
parent 8d70eeb84a
commit 3c1fece881
1 changed files with 10 additions and 3 deletions

View File

@ -98,14 +98,21 @@ static void nft_exthdr_tcp_eval(const struct nft_expr *expr,
goto err;
offset = i + priv->offset;
dest[priv->len / NFT_REG32_SIZE] = 0;
memcpy(dest, opt + offset, priv->len);
if (priv->flags & NFT_EXTHDR_F_PRESENT) {
*dest = 1;
} else {
dest[priv->len / NFT_REG32_SIZE] = 0;
memcpy(dest, opt + offset, priv->len);
}
return;
}
err:
regs->verdict.code = NFT_BREAK;
if (priv->flags & NFT_EXTHDR_F_PRESENT)
*dest = 0;
else
regs->verdict.code = NFT_BREAK;
}
static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {