[PATCH net 13/14] netfilter: nft_ct: expectation timeouts are passed in milliseconds

[Pablo Neira Ayuso <pablo@netfilter.org>]

From: Florian Westphal <fw@strlen.de>

Userspace passes '5000' in case user asks for 5 seconds.

Allowing for sub-second expectation lifetimes makes sense to me. so
fix up the kernel side instead of munging nft to send a value rounded
up to next second.

Also note that this violates nft convention of passing integers in
network byte order, but we can't change this anymore.

Fixes: 857b46027d6f ("netfilter: nft_ct: add ct expectations support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_ct.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 958054dd2e2e..03a88c77e0f0 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -1215,11 +1215,23 @@ struct nft_ct_expect_obj {
 	u32		timeout;
 };
 
+static int nft_ct_expect_timeout_get(const struct nlattr *attr, u32 *val)
+{
+	unsigned long jiffies_val = msecs_to_jiffies(nla_get_u32(attr));
+
+	if (jiffies_val > UINT_MAX)
+		return -ERANGE;
+
+	*val = jiffies_val;
+	return 0;
+}
+
 static int nft_ct_expect_obj_init(const struct nft_ctx *ctx,
 				  const struct nlattr * const tb[],
 				  struct nft_object *obj)
 {
 	struct nft_ct_expect_obj *priv = nft_obj_data(obj);
+	int err;
 
 	if (!tb[NFTA_CT_EXPECT_L4PROTO] ||
 	    !tb[NFTA_CT_EXPECT_DPORT] ||
@@ -1254,8 +1266,11 @@ static int nft_ct_expect_obj_init(const struct nft_ctx *ctx,
 		return -EOPNOTSUPP;
 	}
 
+	err = nft_ct_expect_timeout_get(tb[NFTA_CT_EXPECT_TIMEOUT], &priv->timeout);
+	if (err)
+		return err;
+
 	priv->dport = nla_get_be16(tb[NFTA_CT_EXPECT_DPORT]);
-	priv->timeout = nla_get_u32(tb[NFTA_CT_EXPECT_TIMEOUT]);
 	priv->size = nla_get_u8(tb[NFTA_CT_EXPECT_SIZE]);
 
 	return nf_ct_netns_get(ctx->net, ctx->family);
@@ -1275,7 +1290,7 @@ static int nft_ct_expect_obj_dump(struct sk_buff *skb,
 	if (nla_put_be16(skb, NFTA_CT_EXPECT_L3PROTO, htons(priv->l3num)) ||
 	    nla_put_u8(skb, NFTA_CT_EXPECT_L4PROTO, priv->l4proto) ||
 	    nla_put_be16(skb, NFTA_CT_EXPECT_DPORT, priv->dport) ||
-	    nla_put_u32(skb, NFTA_CT_EXPECT_TIMEOUT, priv->timeout) ||
+	    nla_put_u32(skb, NFTA_CT_EXPECT_TIMEOUT, jiffies_to_msecs(priv->timeout)) ||
 	    nla_put_u8(skb, NFTA_CT_EXPECT_SIZE, priv->size))
 		return -1;
 
@@ -1325,7 +1340,7 @@ static void nft_ct_expect_obj_eval(struct nft_object *obj,
 		          &ct->tuplehash[!dir].tuple.src.u3,
 		          &ct->tuplehash[!dir].tuple.dst.u3,
 		          priv->l4proto, NULL, &priv->dport);
-	exp->timeout += priv->timeout * HZ;
+	exp->timeout += priv->timeout;
 
 	if (nf_ct_expect_related(exp, 0) != 0)
 		regs->verdict.code = NF_DROP;
-- 
2.47.3