netfilter: nft_meta: move bridge meta keys into nft_meta_bridge

Separate bridge meta key from nft_meta to meta_bridge to avoid a
dependency between the bridge module and nft_meta when using the bridge
API available through include/linux/if_bridge.h

Signed-off-by: wenxu <wenxu@ucloud.cn>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/net/netfilter/nft_meta.h b/include/net/netfilter/nft_meta.h
new file mode 100644 (file)
index 0000000..5c69e9b
--- /dev/null
+++ b/include/net/netfilter/nft_meta.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NFT_META_H_
+#define _NFT_META_H_
+
+struct nft_meta {
+       enum nft_meta_keys      key:8;
+       union {
+               enum nft_registers      dreg:8;
+               enum nft_registers      sreg:8;
+       };
+};
+
+extern const struct nla_policy nft_meta_policy[];
+
+int nft_meta_get_init(const struct nft_ctx *ctx,
+                     const struct nft_expr *expr,
+                     const struct nlattr * const tb[]);
+
+int nft_meta_set_init(const struct nft_ctx *ctx,
+                     const struct nft_expr *expr,
+                     const struct nlattr * const tb[]);
+
+int nft_meta_get_dump(struct sk_buff *skb,
+                     const struct nft_expr *expr);
+
+int nft_meta_set_dump(struct sk_buff *skb,
+                     const struct nft_expr *expr);
+
+void nft_meta_get_eval(const struct nft_expr *expr,
+                      struct nft_regs *regs,
+                      const struct nft_pktinfo *pkt);
+
+void nft_meta_set_eval(const struct nft_expr *expr,
+                      struct nft_regs *regs,
+                      const struct nft_pktinfo *pkt);
+
+void nft_meta_set_destroy(const struct nft_ctx *ctx,
+                         const struct nft_expr *expr);
+
+int nft_meta_set_validate(const struct nft_ctx *ctx,
+                         const struct nft_expr *expr,
+                         const struct nft_data **data);
+
+#endif

diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig
index f4fb0b9..fbc7085 100644 (file)
--- a/net/bridge/netfilter/Kconfig
+++ b/net/bridge/netfilter/Kconfig
@@ -9,6 +9,12 @@ menuconfig NF_TABLES_BRIDGE
        bool "Ethernet Bridge nf_tables support"
 
 if NF_TABLES_BRIDGE
+
+config NFT_BRIDGE_META
+       tristate "Netfilter nf_table bridge meta support"
+       help
+         Add support for bridge dedicated meta key.
+
 config NFT_BRIDGE_REJECT
        tristate "Netfilter nf_tables bridge reject support"
        depends on NFT_REJECT && NFT_REJECT_IPV4 && NFT_REJECT_IPV6

diff --git a/net/bridge/netfilter/Makefile b/net/bridge/netfilter/Makefile
index 9d77673..8e2c575 100644 (file)
--- a/net/bridge/netfilter/Makefile
+++ b/net/bridge/netfilter/Makefile
@@ -3,6 +3,7 @@
 # Makefile for the netfilter modules for Link Layer filtering on a bridge.
 #
 
+obj-$(CONFIG_NFT_BRIDGE_META)  += nft_meta_bridge.o
 obj-$(CONFIG_NFT_BRIDGE_REJECT)  += nft_reject_bridge.o
 
 # connection tracking

diff --git a/net/bridge/netfilter/nft_meta_bridge.c b/net/bridge/netfilter/nft_meta_bridge.c
new file mode 100644 (file)
index 0000000..dde8651
--- /dev/null
+++ b/net/bridge/netfilter/nft_meta_bridge.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nft_meta.h>
+
+#include "../br_private.h"
+
+static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
+                                    struct nft_regs *regs,
+                                    const struct nft_pktinfo *pkt)
+{
+       const struct nft_meta *priv = nft_expr_priv(expr);
+       const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
+       u32 *dest = &regs->data[priv->dreg];
+       const struct net_bridge_port *p;
+
+       switch (priv->key) {
+       case NFT_META_BRI_IIFNAME:
+               if (in == NULL || (p = br_port_get_rcu(in)) == NULL)
+                       goto err;
+               break;
+       case NFT_META_BRI_OIFNAME:
+               if (out == NULL || (p = br_port_get_rcu(out)) == NULL)
+                       goto err;
+               break;
+       default:
+               goto out;
+       }
+
+       strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
+       return;
+out:
+       return nft_meta_get_eval(expr, regs, pkt);
+err:
+       regs->verdict.code = NFT_BREAK;
+}
+
+static int nft_meta_bridge_get_init(const struct nft_ctx *ctx,
+                                   const struct nft_expr *expr,
+                                   const struct nlattr * const tb[])
+{
+       struct nft_meta *priv = nft_expr_priv(expr);
+       unsigned int len;
+
+       priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
+       switch (priv->key) {
+       case NFT_META_BRI_IIFNAME:
+       case NFT_META_BRI_OIFNAME:
+               len = IFNAMSIZ;
+               break;
+       default:
+               return nft_meta_get_init(ctx, expr, tb);
+       }
+
+       priv->dreg = nft_parse_register(tb[NFTA_META_DREG]);
+       return nft_validate_register_store(ctx, priv->dreg, NULL,
+                                          NFT_DATA_VALUE, len);
+}
+
+static struct nft_expr_type nft_meta_bridge_type;
+static const struct nft_expr_ops nft_meta_bridge_get_ops = {
+       .type           = &nft_meta_bridge_type,
+       .size           = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
+       .eval           = nft_meta_bridge_get_eval,
+       .init           = nft_meta_bridge_get_init,
+       .dump           = nft_meta_get_dump,
+};
+
+static const struct nft_expr_ops nft_meta_bridge_set_ops = {
+       .type           = &nft_meta_bridge_type,
+       .size           = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
+       .eval           = nft_meta_set_eval,
+       .init           = nft_meta_set_init,
+       .destroy        = nft_meta_set_destroy,
+       .dump           = nft_meta_set_dump,
+       .validate       = nft_meta_set_validate,
+};
+
+static const struct nft_expr_ops *
+nft_meta_bridge_select_ops(const struct nft_ctx *ctx,
+                          const struct nlattr * const tb[])
+{
+       if (tb[NFTA_META_KEY] == NULL)
+               return ERR_PTR(-EINVAL);
+
+       if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
+               return ERR_PTR(-EINVAL);
+
+       if (tb[NFTA_META_DREG])
+               return &nft_meta_bridge_get_ops;
+
+       if (tb[NFTA_META_SREG])
+               return &nft_meta_bridge_set_ops;
+
+       return ERR_PTR(-EINVAL);
+}
+
+static struct nft_expr_type nft_meta_bridge_type __read_mostly = {
+       .family         = NFPROTO_BRIDGE,
+       .name           = "meta",
+       .select_ops     = nft_meta_bridge_select_ops,
+       .policy         = nft_meta_policy,
+       .maxattr        = NFTA_META_MAX,
+       .owner          = THIS_MODULE,
+};
+
+static int __init nft_meta_bridge_module_init(void)
+{
+       return nft_register_expr(&nft_meta_bridge_type);
+}
+
+static void __exit nft_meta_bridge_module_exit(void)
+{
+       nft_unregister_expr(&nft_meta_bridge_type);
+}
+
+module_init(nft_meta_bridge_module_init);
+module_exit(nft_meta_bridge_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta");

diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index b950cd3..96c74c4 100644 (file)
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -19,6 +19,7 @@
 #include <net/netfilter/nf_tables_core.h>
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nf_log.h>
+#include <net/netfilter/nft_meta.h>
 
 static noinline void __nft_trace_packet(struct nft_traceinfo *info,
                                        const struct nft_chain *chain,

diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index a54329b..18a848b 100644 (file)
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -21,23 +21,12 @@
 #include <net/tcp_states.h> /* for TCP_TIME_WAIT */
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nft_meta.h>
 
 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */
 
-struct nft_meta {
-       enum nft_meta_keys      key:8;
-       union {
-               enum nft_registers      dreg:8;
-               enum nft_registers      sreg:8;
-       };
-};
-
 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);
 
-#ifdef CONFIG_NF_TABLES_BRIDGE
-#include "../bridge/br_private.h"
-#endif
-
 void nft_meta_get_eval(const struct nft_expr *expr,
                       struct nft_regs *regs,
                       const struct nft_pktinfo *pkt)
@@ -47,9 +36,6 @@ void nft_meta_get_eval(const struct nft_expr *expr,
        const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
        struct sock *sk;
        u32 *dest = &regs->data[priv->dreg];
-#ifdef CONFIG_NF_TABLES_BRIDGE
-       const struct net_bridge_port *p;
-#endif
 
        switch (priv->key) {
        case NFT_META_LEN:
@@ -228,18 +214,6 @@ void nft_meta_get_eval(const struct nft_expr *expr,
        case NFT_META_SECPATH:
                nft_reg_store8(dest, secpath_exists(skb));
                break;
-#endif
-#ifdef CONFIG_NF_TABLES_BRIDGE
-       case NFT_META_BRI_IIFNAME:
-               if (in == NULL || (p = br_port_get_rcu(in)) == NULL)
-                       goto err;
-               strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
-               return;
-       case NFT_META_BRI_OIFNAME:
-               if (out == NULL || (p = br_port_get_rcu(out)) == NULL)
-                       goto err;
-               strncpy((char *)dest, p->br->dev->name, IFNAMSIZ);
-               return;
 #endif
        case NFT_META_IIFKIND:
                if (in == NULL || in->rtnl_link_ops == NULL)
@@ -260,10 +234,11 @@ void nft_meta_get_eval(const struct nft_expr *expr,
 err:
        regs->verdict.code = NFT_BREAK;
 }
+EXPORT_SYMBOL_GPL(nft_meta_get_eval);
 
-static void nft_meta_set_eval(const struct nft_expr *expr,
-                             struct nft_regs *regs,
-                              const struct nft_pktinfo *pkt)
+void nft_meta_set_eval(const struct nft_expr *expr,
+                      struct nft_regs *regs,
+                      const struct nft_pktinfo *pkt)
 {
        const struct nft_meta *meta = nft_expr_priv(expr);
        struct sk_buff *skb = pkt->skb;
@@ -300,16 +275,18 @@ static void nft_meta_set_eval(const struct nft_expr *expr,
                WARN_ON(1);
        }
 }
+EXPORT_SYMBOL_GPL(nft_meta_set_eval);
 
-static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
+const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
        [NFTA_META_DREG]        = { .type = NLA_U32 },
        [NFTA_META_KEY]         = { .type = NLA_U32 },
        [NFTA_META_SREG]        = { .type = NLA_U32 },
 };
+EXPORT_SYMBOL_GPL(nft_meta_policy);
 
-static int nft_meta_get_init(const struct nft_ctx *ctx,
-                            const struct nft_expr *expr,
-                            const struct nlattr * const tb[])
+int nft_meta_get_init(const struct nft_ctx *ctx,
+                     const struct nft_expr *expr,
+                     const struct nlattr * const tb[])
 {
        struct nft_meta *priv = nft_expr_priv(expr);
        unsigned int len;
@@ -359,14 +336,6 @@ static int nft_meta_get_init(const struct nft_ctx *ctx,
        case NFT_META_SECPATH:
                len = sizeof(u8);
                break;
-#endif
-#ifdef CONFIG_NF_TABLES_BRIDGE
-       case NFT_META_BRI_IIFNAME:
-       case NFT_META_BRI_OIFNAME:
-               if (ctx->family != NFPROTO_BRIDGE)
-                       return -EOPNOTSUPP;
-               len = IFNAMSIZ;
-               break;
 #endif
        default:
                return -EOPNOTSUPP;
@@ -376,6 +345,7 @@ static int nft_meta_get_init(const struct nft_ctx *ctx,
        return nft_validate_register_store(ctx, priv->dreg, NULL,
                                           NFT_DATA_VALUE, len);
 }
+EXPORT_SYMBOL_GPL(nft_meta_get_init);
 
 static int nft_meta_get_validate(const struct nft_ctx *ctx,
                                 const struct nft_expr *expr,
@@ -409,9 +379,9 @@ static int nft_meta_get_validate(const struct nft_ctx *ctx,
 #endif
 }
 
-static int nft_meta_set_validate(const struct nft_ctx *ctx,
-                                const struct nft_expr *expr,
-                                const struct nft_data **data)
+int nft_meta_set_validate(const struct nft_ctx *ctx,
+                         const struct nft_expr *expr,
+                         const struct nft_data **data)
 {
        struct nft_meta *priv = nft_expr_priv(expr);
        unsigned int hooks;
@@ -437,10 +407,11 @@ static int nft_meta_set_validate(const struct nft_ctx *ctx,
 
        return nft_chain_validate_hooks(ctx->chain, hooks);
 }
+EXPORT_SYMBOL_GPL(nft_meta_set_validate);
 
-static int nft_meta_set_init(const struct nft_ctx *ctx,
-                            const struct nft_expr *expr,
-                            const struct nlattr * const tb[])
+int nft_meta_set_init(const struct nft_ctx *ctx,
+                     const struct nft_expr *expr,
+                     const struct nlattr * const tb[])
 {
        struct nft_meta *priv = nft_expr_priv(expr);
        unsigned int len;
@@ -475,9 +446,10 @@ static int nft_meta_set_init(const struct nft_ctx *ctx,
 
        return 0;
 }
+EXPORT_SYMBOL_GPL(nft_meta_set_init);
 
-static int nft_meta_get_dump(struct sk_buff *skb,
-                            const struct nft_expr *expr)
+int nft_meta_get_dump(struct sk_buff *skb,
+                     const struct nft_expr *expr)
 {
        const struct nft_meta *priv = nft_expr_priv(expr);
 
@@ -490,8 +462,9 @@ static int nft_meta_get_dump(struct sk_buff *skb,
 nla_put_failure:
        return -1;
 }
+EXPORT_SYMBOL_GPL(nft_meta_get_dump);
 
-static int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
+int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
 {
        const struct nft_meta *priv = nft_expr_priv(expr);
 
@@ -505,15 +478,17 @@ static int nft_meta_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
 nla_put_failure:
        return -1;
 }
+EXPORT_SYMBOL_GPL(nft_meta_set_dump);
 
-static void nft_meta_set_destroy(const struct nft_ctx *ctx,
-                                const struct nft_expr *expr)
+void nft_meta_set_destroy(const struct nft_ctx *ctx,
+                         const struct nft_expr *expr)
 {
        const struct nft_meta *priv = nft_expr_priv(expr);
 
        if (priv->key == NFT_META_NFTRACE)
                static_branch_dec(&nft_trace_enabled);
 }
+EXPORT_SYMBOL_GPL(nft_meta_set_destroy);
 
 static const struct nft_expr_ops nft_meta_get_ops = {
        .type           = &nft_meta_type,