nft_ct expression cannot be made builtin to nf_tables without also
forcing the conntrack itself to be builtin.
However, this can be avoided by splitting retrieval of a few
selector keys that only need to access the nf_conn structure,
i.e. no function calls to nf_conntrack code.
Many rulesets start with something like
"ct status established,related accept"
With this change, this no longer requires an indirect call.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
include/net/netfilter/nf_tables_core.h | 12 ++++++
net/netfilter/Makefile | 6 +++
net/netfilter/nf_tables_core.c | 3 ++
net/netfilter/nft_ct.c | 39 ++++++++++++------
net/netfilter/nft_ct_fast.c | 56 ++++++++++++++++++++++++++
5 files changed, 104 insertions(+), 12 deletions(-)
create mode 100644 net/netfilter/nft_ct_fast.c
diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h
index bedef373ec21..780a5f6ad4a6 100644
--- a/include/net/netfilter/nf_tables_core.h
+++ b/include/net/netfilter/nf_tables_core.h
@@ -61,6 +61,16 @@ struct nft_immediate_expr {
extern const struct nft_expr_ops nft_cmp_fast_ops;
extern const struct nft_expr_ops nft_cmp16_fast_ops;
+struct nft_ct {
+ enum nft_ct_keys key:8;
+ enum ip_conntrack_dir dir:8;
+ u8 len;
+ union {
+ u8 dreg;
+ u8 sreg;
+ };
+};
+
struct nft_payload {
enum nft_payload_bases base:8;
u8 offset;
@@ -140,6 +150,8 @@ void nft_rt_get_eval(const struct nft_expr *expr,
struct nft_regs *regs, const struct nft_pktinfo *pkt);
void nft_counter_eval(const struct nft_expr *expr, struct nft_regs *regs,
const struct nft_pktinfo *pkt);
+void nft_ct_get_fast_eval(const struct nft_expr *expr,
+ struct nft_regs *regs, const struct nft_pktinfo *pkt);
enum {
NFT_PAYLOAD_CTX_INNER_TUN = (1 << 0),
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 3754eb06fb41..ba2a6b5e93d9 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -98,6 +98,12 @@ nf_tables-objs += nft_set_pipapo_avx2.o
endif
endif
+ifdef CONFIG_NFT_CT
+ifdef CONFIG_RETPOLINE
+nf_tables-objs += nft_ct_fast.o
+endif
+endif
+
obj-$(CONFIG_NF_TABLES) += nf_tables.o
obj-$(CONFIG_NFT_COMPAT) += nft_compat.o
obj-$(CONFIG_NFT_CONNLIMIT) += nft_connlimit.o
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index d9992906199f..6ecd0ba2e546 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -228,6 +228,9 @@ static void expr_call_ops_eval(const struct nft_expr *expr,
X(e, nft_counter_eval);
X(e, nft_meta_get_eval);
X(e, nft_lookup_eval);
+#if IS_ENABLED(CONFIG_NFT_CT)
+ X(e, nft_ct_get_fast_eval);
+#endif
X(e, nft_range_eval);
X(e, nft_immediate_eval);
X(e, nft_byteorder_eval);
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index c68e2151defe..b9c84499438b 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -12,7 +12,7 @@
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
-#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_tuple.h>
@@ -23,16 +23,6 @@
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_expect.h>
-struct nft_ct {
- enum nft_ct_keys key:8;
- enum ip_conntrack_dir dir:8;
- u8 len;
- union {
- u8 dreg;
- u8 sreg;
- };
-};
-
struct nft_ct_helper_obj {
struct nf_conntrack_helper *helper4;
struct nf_conntrack_helper *helper6;
@@ -759,6 +749,18 @@ static bool nft_ct_set_reduce(struct nft_regs_track *track,
return false;
}
+#ifdef CONFIG_RETPOLINE
+static const struct nft_expr_ops nft_ct_get_fast_ops = {
+ .type = &nft_ct_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)),
+ .eval = nft_ct_get_fast_eval,
+ .init = nft_ct_get_init,
+ .destroy = nft_ct_get_destroy,
+ .dump = nft_ct_get_dump,
+ .reduce = nft_ct_set_reduce,
+};
+#endif
+
static const struct nft_expr_ops nft_ct_set_ops = {
.type = &nft_ct_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_ct)),
@@ -791,8 +793,21 @@ nft_ct_select_ops(const struct nft_ctx *ctx,
if (tb[NFTA_CT_DREG] && tb[NFTA_CT_SREG])
return ERR_PTR(-EINVAL);
- if (tb[NFTA_CT_DREG])
+ if (tb[NFTA_CT_DREG]) {
+#ifdef CONFIG_RETPOLINE
+ u32 k = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
+
+ switch (k) {
+ case NFT_CT_STATE:
+ case NFT_CT_DIRECTION:
+ case NFT_CT_STATUS:
+ case NFT_CT_MARK:
+ case NFT_CT_SECMARK:
+ return &nft_ct_get_fast_ops;
+ }
+#endif
return &nft_ct_get_ops;
+ }
if (tb[NFTA_CT_SREG]) {
#ifdef CONFIG_NF_CONNTRACK_ZONES
diff --git a/net/netfilter/nft_ct_fast.c b/net/netfilter/nft_ct_fast.c
new file mode 100644
index 000000000000..89983b0613fa
--- /dev/null
+++ b/net/netfilter/nft_ct_fast.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#if IS_ENABLED(CONFIG_NFT_CT)
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_conntrack.h>
+
+void nft_ct_get_fast_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_ct *priv = nft_expr_priv(expr);
+ u32 *dest = ®s->data[priv->dreg];
+ enum ip_conntrack_info ctinfo;
+ const struct nf_conn *ct;
+ unsigned int state;
+
+ ct = nf_ct_get(pkt->skb, &ctinfo);
+ if (!ct) {
+ regs->verdict.code = NFT_BREAK;
+ return;
+ }
+
+ switch (priv->key) {
+ case NFT_CT_STATE:
+ if (ct)
+ state = NF_CT_STATE_BIT(ctinfo);
+ else if (ctinfo == IP_CT_UNTRACKED)
+ state = NF_CT_STATE_UNTRACKED_BIT;
+ else
+ state = NF_CT_STATE_INVALID_BIT;
+ *dest = state;
+ return;
+ case NFT_CT_DIRECTION:
+ nft_reg_store8(dest, CTINFO2DIR(ctinfo));
+ return;
+ case NFT_CT_STATUS:
+ *dest = ct->status;
+ return;
+#ifdef CONFIG_NF_CONNTRACK_MARK
+ case NFT_CT_MARK:
+ *dest = ct->mark;
+ return;
+#endif
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+ case NFT_CT_SECMARK:
+ *dest = ct->secmark;
+ return;
+#endif
+ default:
+ WARN_ON_ONCE(1);
+ regs->verdict.code = NFT_BREAK;
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(nft_ct_get_fast_eval);
+#endif
--
2.38.2
