This patch allows to add, list and delete expectations via nft objref
infrastructure and assigning these expectations via nft rule.
Signed-off-by: Stéphane Veyret <sveyret@xxxxxxxxx>
---
include/uapi/linux/netfilter/nf_tables.h | 15 ++-
net/netfilter/nft_ct.c | 124 ++++++++++++++++++++++-
2 files changed, 136 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index f0cf7b0f4f35..0a3452ca684c 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -968,6 +968,7 @@ enum nft_socket_keys {
* @NFT_CT_DST_IP6: conntrack layer 3 protocol destination (IPv6 address)
* @NFT_CT_TIMEOUT: connection tracking timeout policy assigned to conntrack
* @NFT_CT_ID: conntrack id
+ * @NFT_CT_EXPECT: connection tracking expectation
*/
enum nft_ct_keys {
NFT_CT_STATE,
@@ -995,6 +996,7 @@ enum nft_ct_keys {
NFT_CT_DST_IP6,
NFT_CT_TIMEOUT,
NFT_CT_ID,
+ NFT_CT_EXPECT,
__NFT_CT_MAX
};
#define NFT_CT_MAX (__NFT_CT_MAX - 1)
@@ -1447,6 +1449,16 @@ enum nft_ct_timeout_timeout_attributes {
};
#define NFTA_CT_TIMEOUT_MAX (__NFTA_CT_TIMEOUT_MAX - 1)
+enum nft_ct_expectation_attributes {
+ NFTA_CT_EXPECT_UNSPEC,
+ NFTA_CT_EXPECT_L3PROTO,
+ NFTA_CT_EXPECT_L4PROTO,
+ NFTA_CT_EXPECT_DPORT,
+ NFTA_CT_EXPECT_TIMEOUT,
+ __NFTA_CT_EXPECT_MAX,
+};
+#define NFTA_CT_EXPECT_MAX (__NFTA_CT_EXPECT_MAX - 1)
+
#define NFT_OBJECT_UNSPEC 0
#define NFT_OBJECT_COUNTER 1
#define NFT_OBJECT_QUOTA 2
@@ -1456,7 +1468,8 @@ enum nft_ct_timeout_timeout_attributes {
#define NFT_OBJECT_TUNNEL 6
#define NFT_OBJECT_CT_TIMEOUT 7
#define NFT_OBJECT_SECMARK 8
-#define __NFT_OBJECT_MAX 9
+#define NFT_OBJECT_CT_EXPECT 9
+#define __NFT_OBJECT_MAX 10
#define NFT_OBJECT_MAX (__NFT_OBJECT_MAX - 1)
/**
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index f043936763f3..06c13b2dfb78 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -24,6 +24,7 @@
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_timeout.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_expect.h>
struct nft_ct {
enum nft_ct_keys key:8;
@@ -790,6 +791,117 @@ static struct nft_expr_type nft_notrack_type __read_mostly = {
.owner = THIS_MODULE,
};
+struct nft_ct_expect_obj {
+ int l3num;
+ u8 l4proto;
+ __be16 dport;
+ u32 timeout;
+};
+
+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 ret;
+
+ if (!tb[NFTA_CT_EXPECT_L4PROTO] ||
+ !tb[NFTA_CT_EXPECT_DPORT])
+ return -EINVAL;
+
+ priv->l3num = ctx->family;
+ if (tb[NFTA_CT_EXPECT_L3PROTO])
+ priv->l3num = ntohs(nla_get_be16(tb[NFTA_CT_EXPECT_L3PROTO]));
+ priv->l4proto = nla_get_u8(tb[NFTA_CT_EXPECT_L4PROTO]);
+
+ priv->dportmin = nla_get_be16(tb[NFTA_CT_EXPECT_DPORT_MIN]);
+
+ priv->timeout = 0;
+ if (tb[NFTA_CT_EXPECT_TIMEOUT])
+ priv->timeout = nla_get_u32(tb[NFTA_CT_EXPECT_TIMEOUT]);
+
+ ret = nf_ct_netns_get(ctx->net, ctx->family);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static void nft_ct_expect_obj_destroy(const struct nft_ctx *ctx,
+ struct nft_object *obj)
+{
+ nf_ct_netns_put(ctx->net, ctx->family);
+}
+
+static int nft_ct_expect_obj_dump(struct sk_buff *skb,
+ struct nft_object *obj, bool reset)
+{
+ const struct nft_ct_expect_obj *priv = nft_obj_data(obj);
+
+ 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))
+ return -1
+
+ return 0;
+}
+
+static void nft_ct_expect_obj_eval(struct nft_object *obj,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_ct_expect_obj *priv = nft_obj_data(obj);
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct = nf_ct_get(pkt->skb, ctinfo);
+ int dir = CTINFO2DIR(ctinfo);
+ struct nf_conntrack_expect *exp;
+
+ exp = nf_ct_expect_alloc(ct);
+ if (exp == NULL) {
+ nf_ct_helper_log(skb, ct, "cannot allocate expectation");
+ regs->verdict.code = NF_DROP;
+ return;
+ }
+
+ nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, priv->l3num,
+ &ct->tuplehash[!dir].tuple.src.u3, &ct->tuplehash[!dir].tuple.dst.u3,
+ priv->l4proto, NULL, &priv->dport);
+ if (priv->timeout)
+ exp->timeout.expires = jiffies + priv->timeout * HZ;
+
+ if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
+ regs->verdict.code = NF_DROP;
+ }
+}
+
+static const struct nla_policy nft_ct_expect_policy[NFTA_CT_EXPECT_MAX + 1] = {
+ [NFTA_CT_EXPECT_L3PROTO] = {.type = NLA_U16 },
+ [NFTA_CT_EXPECT_L4PROTO] = {.type = NLA_U8 },
+ [NFTA_CT_EXPECT_DPORT] = {.type = NLA_U16 },
+ [NFTA_CT_EXPECT_TIMEOUT] = {.type = NLA_U32 },
+};
+
+static struct nft_object_type nft_ct_expect_obj_type;
+
+static const struct nft_object_ops nft_ct_expect_obj_ops = {
+ .type = &nft_ct_expect_obj_type,
+ .size = sizeof(struct nft_ct_expect_obj),
+ .eval = nft_ct_expect_obj_eval,
+ .init = nft_ct_expect_obj_init,
+ .destroy = nft_ct_expect_obj_destroy,
+ .dump = nft_ct_expect_obj_dump,
+};
+
+static struct nft_object_type nft_ct_expect_obj_type __read_mostly = {
+ .type = NFT_OBJECT_CT_EXPECT,
+ .ops = &nft_ct_expect_obj_ops,
+ .maxattr = NFTA_CT_EXPECT_MAX,
+ .policy = nft_ct_expect_policy,
+ .owner = THIS_MODULE,
+};
+
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
static int
nft_ct_timeout_parse_policy(void *timeouts,
@@ -1173,17 +1285,23 @@ static int __init nft_ct_module_init(void)
err = nft_register_obj(&nft_ct_helper_obj_type);
if (err < 0)
goto err2;
+
+ err = nft_register_obj(&nft_ct_expect_obj_type);
+ if (err < 0)
+ goto err3;
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
err = nft_register_obj(&nft_ct_timeout_obj_type);
if (err < 0)
- goto err3;
+ goto err4;
#endif
return 0;
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+err4:
+ nft_unregister_obj(&nft_ct_expect_obj_type);
+#endif
err3:
nft_unregister_obj(&nft_ct_helper_obj_type);
-#endif
err2:
nft_unregister_expr(&nft_notrack_type);
err1:
@@ -1196,6 +1314,7 @@ static void __exit nft_ct_module_exit(void)
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
nft_unregister_obj(&nft_ct_timeout_obj_type);
#endif
+ nft_unregister_obj(&nft_ct_expect_obj_type);
nft_unregister_obj(&nft_ct_helper_obj_type);
nft_unregister_expr(&nft_notrack_type);
nft_unregister_expr(&nft_ct_type);
@@ -1210,3 +1329,4 @@ MODULE_ALIAS_NFT_EXPR("ct");
MODULE_ALIAS_NFT_EXPR("notrack");
MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_CT_HELPER);
MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_CT_TIMEOUT);
+MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_CT_EXPECT);
--
2.21.0
