From: Kristian Evensen <kristian.evensen@xxxxxxxxx>
This patch adds kernel support for setting properties of tracked connections.
Currently, only connmark is supported. One use-case for this feature is to
provide the same functionality as -j CONNMARK --save-mark in iptables.
Some restructuring was needed to implement the set op. The new structure follows
that of nft_meta.
v1->v2:
Check if mark changes value before updating, to prevent event storm.
Signed-off-by: Kristian Evensen <kristian.evensen@xxxxxxxxx>
---
include/uapi/linux/netfilter/nf_tables.h | 2 +
net/netfilter/nft_ct.c | 163 +++++++++++++++++++++++++------
2 files changed, 134 insertions(+), 31 deletions(-)
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index aa86a152..ead57b1 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -605,12 +605,14 @@ enum nft_ct_keys {
* @NFTA_CT_DREG: destination register (NLA_U32)
* @NFTA_CT_KEY: conntrack data item to load (NLA_U32: nft_ct_keys)
* @NFTA_CT_DIRECTION: direction in case of directional keys (NLA_U8)
+ * @NFTA_CT_SREG: source register (NLA_U32)
*/
enum nft_ct_attributes {
NFTA_CT_UNSPEC,
NFTA_CT_DREG,
NFTA_CT_KEY,
NFTA_CT_DIRECTION,
+ NFTA_CT_SREG,
__NFTA_CT_MAX
};
#define NFTA_CT_MAX (__NFTA_CT_MAX - 1)
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 955f4e6..8936c01 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -18,17 +18,21 @@
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
struct nft_ct {
enum nft_ct_keys key:8;
enum ip_conntrack_dir dir:8;
- enum nft_registers dreg:8;
+ union{
+ enum nft_registers dreg:8;
+ enum nft_registers sreg:8;
+ };
uint8_t family;
};
-static void nft_ct_eval(const struct nft_expr *expr,
- struct nft_data data[NFT_REG_MAX + 1],
- const struct nft_pktinfo *pkt)
+static void nft_ct_get_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
{
const struct nft_ct *priv = nft_expr_priv(expr);
struct nft_data *dest = &data[priv->dreg];
@@ -123,24 +127,45 @@ err:
data[NFT_REG_VERDICT].verdict = NFT_BREAK;
}
+static void nft_ct_set_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_ct *priv = nft_expr_priv(expr);
+ struct sk_buff *skb = pkt->skb;
+ u32 value = data[priv->sreg].data[0];
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+
+ ct = nf_ct_get(skb, &ctinfo);
+
+ if (ct == NULL)
+ return;
+
+ switch (priv->key) {
+#ifdef CONFIG_NF_CONNTRACK_MARK
+ case NFT_CT_MARK:
+ if (ct->mark != value) {
+ ct->mark = value;
+ nf_conntrack_event_cache(IPCT_MARK, ct);
+ }
+ break;
+#endif
+ }
+}
+
static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = {
[NFTA_CT_DREG] = { .type = NLA_U32 },
[NFTA_CT_KEY] = { .type = NLA_U32 },
[NFTA_CT_DIRECTION] = { .type = NLA_U8 },
+ [NFTA_CT_SREG] = { .type = NLA_U32 },
};
-static int nft_ct_init(const struct nft_ctx *ctx,
- const struct nft_expr *expr,
- const struct nlattr * const tb[])
+static int nft_ct_init_validate_get(const struct nft_expr *expr,
+ const struct nlattr * const tb[])
{
struct nft_ct *priv = nft_expr_priv(expr);
- int err;
- if (tb[NFTA_CT_DREG] == NULL ||
- tb[NFTA_CT_KEY] == NULL)
- return -EINVAL;
-
- priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
if (tb[NFTA_CT_DIRECTION] != NULL) {
priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]);
switch (priv->dir) {
@@ -179,24 +204,56 @@ static int nft_ct_init(const struct nft_ctx *ctx,
return -EOPNOTSUPP;
}
- err = nf_ct_l3proto_try_module_get(ctx->afi->family);
- if (err < 0)
- return err;
+ return 0;
+}
+
+static int nft_ct_init_validate_set(uint32_t key) {
+ switch (key) {
+ case NFT_CT_MARK:
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int nft_ct_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_ct *priv = nft_expr_priv(expr);
+ int err;
+
+ priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
priv->family = ctx->afi->family;
- priv->dreg = ntohl(nla_get_be32(tb[NFTA_CT_DREG]));
- err = nft_validate_output_register(priv->dreg);
- if (err < 0)
- goto err1;
+ if (tb[NFTA_CT_DREG]) {
+ err = nft_ct_init_validate_get(expr, tb);
+ if (err < 0)
+ return err;
+
+ priv->dreg = ntohl(nla_get_be32(tb[NFTA_CT_DREG]));
+ err = nft_validate_output_register(priv->dreg);
+ if (err < 0)
+ return err;
+
+ err = nft_validate_data_load(ctx, priv->dreg, NULL,
+ NFT_DATA_VALUE);
+ if (err < 0)
+ return err;
+ } else {
+ err = nft_ct_init_validate_set(priv->key);
+ if (err < 0)
+ return err;
- err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
+ priv->sreg = ntohl(nla_get_be32(tb[NFTA_CT_SREG]));
+ }
+
+ err = nf_ct_l3proto_try_module_get(ctx->afi->family);
if (err < 0)
- goto err1;
- return 0;
+ return err;
-err1:
- nf_ct_l3proto_module_put(ctx->afi->family);
- return err;
+ return 0;
}
static void nft_ct_destroy(const struct nft_expr *expr)
@@ -206,7 +263,7 @@ static void nft_ct_destroy(const struct nft_expr *expr)
nf_ct_l3proto_module_put(priv->family);
}
-static int nft_ct_dump(struct sk_buff *skb, const struct nft_expr *expr)
+static int nft_ct_get_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_ct *priv = nft_expr_priv(expr);
@@ -222,19 +279,63 @@ nla_put_failure:
return -1;
}
+static int nft_ct_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_ct *priv = nft_expr_priv(expr);
+
+ if (nla_put_be32(skb, NFTA_CT_SREG, htonl(priv->sreg)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key)))
+ goto nla_put_failure;
+ if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
static struct nft_expr_type nft_ct_type;
-static const struct nft_expr_ops nft_ct_ops = {
+static const struct nft_expr_ops nft_ct_get_ops = {
.type = &nft_ct_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_ct)),
- .eval = nft_ct_eval,
+ .eval = nft_ct_get_eval,
.init = nft_ct_init,
.destroy = nft_ct_destroy,
- .dump = nft_ct_dump,
+ .dump = nft_ct_get_dump,
};
+static const struct nft_expr_ops nft_ct_set_ops = {
+ .type = &nft_ct_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)),
+ .eval = nft_ct_set_eval,
+ .init = nft_ct_init,
+ .destroy = nft_ct_destroy,
+ .dump = nft_ct_set_dump,
+};
+
+static const struct nft_expr_ops *
+nft_ct_select_ops(const struct nft_ctx *ctx,
+ const struct nlattr * const tb[])
+{
+ if (tb[NFTA_CT_KEY] == NULL)
+ return ERR_PTR(-EINVAL);
+
+ if (tb[NFTA_CT_DREG] && tb[NFTA_CT_SREG])
+ return ERR_PTR(-EINVAL);
+
+ if (tb[NFTA_CT_DREG])
+ return &nft_ct_get_ops;
+
+ if (tb[NFTA_CT_SREG])
+ return &nft_ct_set_ops;
+
+ return ERR_PTR(-EINVAL);
+}
+
static struct nft_expr_type nft_ct_type __read_mostly = {
.name = "ct",
- .ops = &nft_ct_ops,
+ .select_ops = &nft_ct_select_ops,
.policy = nft_ct_policy,
.maxattr = NFTA_CT_MAX,
.owner = THIS_MODULE,
--
1.8.3.2
--
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