netfilter: nft_synproxy: add synproxy stateful object support

Register a new synproxy stateful object type into the stateful object
infrastructure.

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 0ff932dadc8e3d943d78acd6124d7953dd4f7a0f..ed8881ad18edd07ad799c387e0c76b754fd54c0f 100644 (file)
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1481,7 +1481,8 @@ enum nft_ct_expectation_attributes {
 #define NFT_OBJECT_CT_TIMEOUT  7
 #define NFT_OBJECT_SECMARK     8
 #define NFT_OBJECT_CT_EXPECT   9
-#define __NFT_OBJECT_MAX       10
+#define NFT_OBJECT_SYNPROXY    10
+#define __NFT_OBJECT_MAX       11
 #define NFT_OBJECT_MAX         (__NFT_OBJECT_MAX - 1)
 
 /**

diff --git a/net/netfilter/nft_synproxy.c b/net/netfilter/nft_synproxy.c
index db4c23f5dfcbd9490d53ddd71907381ed060c70f..e2c1fc608841221ed7ee475857c3e0b20226f30d 100644 (file)
--- a/net/netfilter/nft_synproxy.c
+++ b/net/netfilter/nft_synproxy.c
@@ -24,7 +24,7 @@ static void nft_synproxy_tcp_options(struct synproxy_options *opts,
                                     const struct tcphdr *tcp,
                                     struct synproxy_net *snet,
                                     struct nf_synproxy_info *info,
-                                    struct nft_synproxy *priv)
+                                    const struct nft_synproxy *priv)
 {
        this_cpu_inc(snet->stats->syn_received);
        if (tcp->ece && tcp->cwr)
@@ -41,14 +41,13 @@ static void nft_synproxy_tcp_options(struct synproxy_options *opts,
                                   NF_SYNPROXY_OPT_ECN);
 }
 
-static void nft_synproxy_eval_v4(const struct nft_expr *expr,
+static void nft_synproxy_eval_v4(const struct nft_synproxy *priv,
                                 struct nft_regs *regs,
                                 const struct nft_pktinfo *pkt,
                                 const struct tcphdr *tcp,
                                 struct tcphdr *_tcph,
                                 struct synproxy_options *opts)
 {
-       struct nft_synproxy *priv = nft_expr_priv(expr);
        struct nf_synproxy_info info = priv->info;
        struct net *net = nft_net(pkt);
        struct synproxy_net *snet = synproxy_pernet(net);
@@ -73,14 +72,13 @@ static void nft_synproxy_eval_v4(const struct nft_expr *expr,
 }
 
 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
-static void nft_synproxy_eval_v6(const struct nft_expr *expr,
+static void nft_synproxy_eval_v6(const struct nft_synproxy *priv,
                                 struct nft_regs *regs,
                                 const struct nft_pktinfo *pkt,
                                 const struct tcphdr *tcp,
                                 struct tcphdr *_tcph,
                                 struct synproxy_options *opts)
 {
-       struct nft_synproxy *priv = nft_expr_priv(expr);
        struct nf_synproxy_info info = priv->info;
        struct net *net = nft_net(pkt);
        struct synproxy_net *snet = synproxy_pernet(net);
@@ -105,9 +103,9 @@ static void nft_synproxy_eval_v6(const struct nft_expr *expr,
 }
 #endif /* CONFIG_NF_TABLES_IPV6*/
 
-static void nft_synproxy_eval(const struct nft_expr *expr,
-                             struct nft_regs *regs,
-                             const struct nft_pktinfo *pkt)
+static void nft_synproxy_do_eval(const struct nft_synproxy *priv,
+                                struct nft_regs *regs,
+                                const struct nft_pktinfo *pkt)
 {
        struct synproxy_options opts = {};
        struct sk_buff *skb = pkt->skb;
@@ -140,23 +138,22 @@ static void nft_synproxy_eval(const struct nft_expr *expr,
 
        switch (skb->protocol) {
        case htons(ETH_P_IP):
-               nft_synproxy_eval_v4(expr, regs, pkt, tcp, &_tcph, &opts);
+               nft_synproxy_eval_v4(priv, regs, pkt, tcp, &_tcph, &opts);
                return;
 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
        case htons(ETH_P_IPV6):
-               nft_synproxy_eval_v6(expr, regs, pkt, tcp, &_tcph, &opts);
+               nft_synproxy_eval_v6(priv, regs, pkt, tcp, &_tcph, &opts);
                return;
 #endif
        }
        regs->verdict.code = NFT_BREAK;
 }
 
-static int nft_synproxy_init(const struct nft_ctx *ctx,
-                            const struct nft_expr *expr,
-                            const struct nlattr * const tb[])
+static int nft_synproxy_do_init(const struct nft_ctx *ctx,
+                               const struct nlattr * const tb[],
+                               struct nft_synproxy *priv)
 {
        struct synproxy_net *snet = synproxy_pernet(ctx->net);
-       struct nft_synproxy *priv = nft_expr_priv(expr);
        u32 flags;
        int err;
 
@@ -206,8 +203,7 @@ nf_ct_failure:
        return err;
 }
 
-static void nft_synproxy_destroy(const struct nft_ctx *ctx,
-                                const struct nft_expr *expr)
+static void nft_synproxy_do_destroy(const struct nft_ctx *ctx)
 {
        struct synproxy_net *snet = synproxy_pernet(ctx->net);
 
@@ -229,10 +225,8 @@ static void nft_synproxy_destroy(const struct nft_ctx *ctx,
        nf_ct_netns_put(ctx->net, ctx->family);
 }
 
-static int nft_synproxy_dump(struct sk_buff *skb, const struct nft_expr *expr)
+static int nft_synproxy_do_dump(struct sk_buff *skb, struct nft_synproxy *priv)
 {
-       const struct nft_synproxy *priv = nft_expr_priv(expr);
-
        if (nla_put_be16(skb, NFTA_SYNPROXY_MSS, htons(priv->info.mss)) ||
            nla_put_u8(skb, NFTA_SYNPROXY_WSCALE, priv->info.wscale) ||
            nla_put_be32(skb, NFTA_SYNPROXY_FLAGS, htonl(priv->info.options)))
@@ -244,6 +238,15 @@ nla_put_failure:
        return -1;
 }
 
+static void nft_synproxy_eval(const struct nft_expr *expr,
+                             struct nft_regs *regs,
+                             const struct nft_pktinfo *pkt)
+{
+       const struct nft_synproxy *priv = nft_expr_priv(expr);
+
+       nft_synproxy_do_eval(priv, regs, pkt);
+}
+
 static int nft_synproxy_validate(const struct nft_ctx *ctx,
                                 const struct nft_expr *expr,
                                 const struct nft_data **data)
@@ -252,6 +255,28 @@ static int nft_synproxy_validate(const struct nft_ctx *ctx,
                                                    (1 << NF_INET_FORWARD));
 }
 
+static int nft_synproxy_init(const struct nft_ctx *ctx,
+                            const struct nft_expr *expr,
+                            const struct nlattr * const tb[])
+{
+       struct nft_synproxy *priv = nft_expr_priv(expr);
+
+       return nft_synproxy_do_init(ctx, tb, priv);
+}
+
+static void nft_synproxy_destroy(const struct nft_ctx *ctx,
+                                const struct nft_expr *expr)
+{
+       nft_synproxy_do_destroy(ctx);
+}
+
+static int nft_synproxy_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+       struct nft_synproxy *priv = nft_expr_priv(expr);
+
+       return nft_synproxy_do_dump(skb, priv);
+}
+
 static struct nft_expr_type nft_synproxy_type;
 static const struct nft_expr_ops nft_synproxy_ops = {
        .eval           = nft_synproxy_eval,
@@ -271,14 +296,89 @@ static struct nft_expr_type nft_synproxy_type __read_mostly = {
        .maxattr        = NFTA_SYNPROXY_MAX,
 };
 
+static int nft_synproxy_obj_init(const struct nft_ctx *ctx,
+                                const struct nlattr * const tb[],
+                                struct nft_object *obj)
+{
+       struct nft_synproxy *priv = nft_obj_data(obj);
+
+       return nft_synproxy_do_init(ctx, tb, priv);
+}
+
+static void nft_synproxy_obj_destroy(const struct nft_ctx *ctx,
+                                    struct nft_object *obj)
+{
+       nft_synproxy_do_destroy(ctx);
+}
+
+static int nft_synproxy_obj_dump(struct sk_buff *skb,
+                                struct nft_object *obj, bool reset)
+{
+       struct nft_synproxy *priv = nft_obj_data(obj);
+
+       return nft_synproxy_do_dump(skb, priv);
+}
+
+static void nft_synproxy_obj_eval(struct nft_object *obj,
+                                 struct nft_regs *regs,
+                                 const struct nft_pktinfo *pkt)
+{
+       const struct nft_synproxy *priv = nft_obj_data(obj);
+
+       nft_synproxy_do_eval(priv, regs, pkt);
+}
+
+static void nft_synproxy_obj_update(struct nft_object *obj,
+                                   struct nft_object *newobj)
+{
+       struct nft_synproxy *newpriv = nft_obj_data(newobj);
+       struct nft_synproxy *priv = nft_obj_data(obj);
+
+       priv->info = newpriv->info;
+}
+
+static struct nft_object_type nft_synproxy_obj_type;
+static const struct nft_object_ops nft_synproxy_obj_ops = {
+       .type           = &nft_synproxy_obj_type,
+       .size           = sizeof(struct nft_synproxy),
+       .init           = nft_synproxy_obj_init,
+       .destroy        = nft_synproxy_obj_destroy,
+       .dump           = nft_synproxy_obj_dump,
+       .eval           = nft_synproxy_obj_eval,
+       .update         = nft_synproxy_obj_update,
+};
+
+static struct nft_object_type nft_synproxy_obj_type __read_mostly = {
+       .type           = NFT_OBJECT_SYNPROXY,
+       .ops            = &nft_synproxy_obj_ops,
+       .maxattr        = NFTA_SYNPROXY_MAX,
+       .policy         = nft_synproxy_policy,
+       .owner          = THIS_MODULE,
+};
+
 static int __init nft_synproxy_module_init(void)
 {
-       return nft_register_expr(&nft_synproxy_type);
+       int err;
+
+       err = nft_register_obj(&nft_synproxy_obj_type);
+       if (err < 0)
+               return err;
+
+       err = nft_register_expr(&nft_synproxy_type);
+       if (err < 0)
+               goto err;
+
+       return 0;
+
+err:
+       nft_unregister_obj(&nft_synproxy_obj_type);
+       return err;
 }
 
 static void __exit nft_synproxy_module_exit(void)
 {
-       return nft_unregister_expr(&nft_synproxy_type);
+       nft_unregister_expr(&nft_synproxy_type);
+       nft_unregister_obj(&nft_synproxy_obj_type);
 }
 
 module_init(nft_synproxy_module_init);
@@ -287,3 +387,4 @@ module_exit(nft_synproxy_module_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Fernando Fernandez <ffmancera@riseup.net>");
 MODULE_ALIAS_NFT_EXPR("synproxy");
+MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_SYNPROXY);