netfilter: nft_reject: support for IPv6 and TCP reset
authorEric Leblond <eric@regit.org>
Sun, 29 Dec 2013 11:28:14 +0000 (12:28 +0100)
committerPablo Neira Ayuso <pablo@netfilter.org>
Mon, 30 Dec 2013 17:15:38 +0000 (18:15 +0100)
This patch moves nft_reject_ipv4 to nft_reject and adds support
for IPv6 protocol. This patch uses functions included in nf_reject.h
to implement reject by TCP reset.

The code has to be build as a module if NF_TABLES_IPV6 is also a
module to avoid compilation error due to usage of IPv6 functions.
This has been done in Kconfig by using the construct:

 depends on NF_TABLES_IPV6 || !NF_TABLES_IPV6

This seems a bit weird in terms of syntax but works perfectly.

Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/ipv4/netfilter/Kconfig
net/ipv4/netfilter/Makefile
net/ipv4/netfilter/nft_reject_ipv4.c [deleted file]
net/netfilter/Kconfig
net/netfilter/Makefile
net/netfilter/nft_reject.c [new file with mode: 0644]

index 40d56073cd19d3b3c27372b7dca255469d7e0068..9d3d69a3204aff6eecdc05bfcfe18fcb1d0d934b 100644 (file)
@@ -40,10 +40,6 @@ config NF_TABLES_IPV4
        depends on NF_TABLES
        tristate "IPv4 nf_tables support"
 
-config NFT_REJECT_IPV4
-       depends on NF_TABLES_IPV4
-       tristate "nf_tables IPv4 reject support"
-
 config NFT_CHAIN_ROUTE_IPV4
        depends on NF_TABLES_IPV4
        tristate "IPv4 nf_tables route chain support"
index 19df72b7ba8810e698bf6d50e8eee5c23033b34a..c16be9d58420dad15b4218ec119b34d184a7ea7e 100644 (file)
@@ -28,7 +28,6 @@ obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o
 obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o
 
 obj-$(CONFIG_NF_TABLES_IPV4) += nf_tables_ipv4.o
-obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o
 obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV4) += nft_chain_route_ipv4.o
 obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o
 obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o
diff --git a/net/ipv4/netfilter/nft_reject_ipv4.c b/net/ipv4/netfilter/nft_reject_ipv4.c
deleted file mode 100644 (file)
index fff5ba1..0000000
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * Development of this code funded by Astaro AG (http://www.astaro.com/)
- */
-
-#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/icmp.h>
-
-struct nft_reject {
-       enum nft_reject_types   type:8;
-       u8                      icmp_code;
-};
-
-static void nft_reject_eval(const struct nft_expr *expr,
-                             struct nft_data data[NFT_REG_MAX + 1],
-                             const struct nft_pktinfo *pkt)
-{
-       struct nft_reject *priv = nft_expr_priv(expr);
-
-       switch (priv->type) {
-       case NFT_REJECT_ICMP_UNREACH:
-               icmp_send(pkt->skb, ICMP_DEST_UNREACH, priv->icmp_code, 0);
-               break;
-       case NFT_REJECT_TCP_RST:
-               break;
-       }
-
-       data[NFT_REG_VERDICT].verdict = NF_DROP;
-}
-
-static const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
-       [NFTA_REJECT_TYPE]              = { .type = NLA_U32 },
-       [NFTA_REJECT_ICMP_CODE]         = { .type = NLA_U8 },
-};
-
-static int nft_reject_init(const struct nft_ctx *ctx,
-                          const struct nft_expr *expr,
-                          const struct nlattr * const tb[])
-{
-       struct nft_reject *priv = nft_expr_priv(expr);
-
-       if (tb[NFTA_REJECT_TYPE] == NULL)
-               return -EINVAL;
-
-       priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
-       switch (priv->type) {
-       case NFT_REJECT_ICMP_UNREACH:
-               if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
-                       return -EINVAL;
-               priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
-       case NFT_REJECT_TCP_RST:
-               break;
-       default:
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-static int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
-{
-       const struct nft_reject *priv = nft_expr_priv(expr);
-
-       if (nla_put_be32(skb, NFTA_REJECT_TYPE, priv->type))
-               goto nla_put_failure;
-
-       switch (priv->type) {
-       case NFT_REJECT_ICMP_UNREACH:
-               if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
-                       goto nla_put_failure;
-               break;
-       }
-
-       return 0;
-
-nla_put_failure:
-       return -1;
-}
-
-static struct nft_expr_type nft_reject_type;
-static const struct nft_expr_ops nft_reject_ops = {
-       .type           = &nft_reject_type,
-       .size           = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
-       .eval           = nft_reject_eval,
-       .init           = nft_reject_init,
-       .dump           = nft_reject_dump,
-};
-
-static struct nft_expr_type nft_reject_type __read_mostly = {
-       .name           = "reject",
-       .ops            = &nft_reject_ops,
-       .policy         = nft_reject_policy,
-       .maxattr        = NFTA_REJECT_MAX,
-       .owner          = THIS_MODULE,
-};
-
-static int __init nft_reject_module_init(void)
-{
-       return nft_register_expr(&nft_reject_type);
-}
-
-static void __exit nft_reject_module_exit(void)
-{
-       nft_unregister_expr(&nft_reject_type);
-}
-
-module_init(nft_reject_module_init);
-module_exit(nft_reject_module_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
-MODULE_ALIAS_NFT_EXPR("reject");
index 01f9f64c4cec0123d0bbe638070a3ed94502efe7..a1dec61a727e45d63e06637adb64022201d032cc 100644 (file)
@@ -465,6 +465,12 @@ config NFT_QUEUE
          This is required if you intend to use the userspace queueing
          infrastructure (also known as NFQUEUE) from nftables.
 
+config NFT_REJECT
+       depends on NF_TABLES
+       depends on NF_TABLES_IPV6 || !NF_TABLES_IPV6
+       default m if NETFILTER_ADVANCED=n
+       tristate "Netfilter nf_tables reject support"
+
 config NFT_COMPAT
        depends on NF_TABLES
        depends on NETFILTER_XTABLES
index dcc818a59ff525965c4805c5cffe4803ae0f429e..39e4a7b78dd9f92dddee2d7ec9bbbdb6d3b0ed3a 100644 (file)
@@ -77,6 +77,7 @@ obj-$(CONFIG_NFT_CT)          += nft_ct.o
 obj-$(CONFIG_NFT_LIMIT)                += nft_limit.o
 obj-$(CONFIG_NFT_NAT)          += nft_nat.o
 obj-$(CONFIG_NFT_QUEUE)                += nft_queue.o
+obj-$(CONFIG_NFT_REJECT)       += nft_reject.o
 obj-$(CONFIG_NFT_RBTREE)       += nft_rbtree.o
 obj-$(CONFIG_NFT_HASH)         += nft_hash.o
 obj-$(CONFIG_NFT_COUNTER)      += nft_counter.o
diff --git a/net/netfilter/nft_reject.c b/net/netfilter/nft_reject.c
new file mode 100644 (file)
index 0000000..0d690d4
--- /dev/null
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
+ * Copyright (c) 2013 Eric Leblond <eric@regit.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ */
+
+#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/icmp.h>
+#include <net/netfilter/ipv4/nf_reject.h>
+
+#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
+#include <net/netfilter/ipv6/nf_reject.h>
+#endif
+
+struct nft_reject {
+       enum nft_reject_types   type:8;
+       u8                      icmp_code;
+       u8                      family;
+};
+
+static void nft_reject_eval(const struct nft_expr *expr,
+                             struct nft_data data[NFT_REG_MAX + 1],
+                             const struct nft_pktinfo *pkt)
+{
+       struct nft_reject *priv = nft_expr_priv(expr);
+       struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
+
+       switch (priv->type) {
+       case NFT_REJECT_ICMP_UNREACH:
+               if (priv->family == NFPROTO_IPV4)
+                       nf_send_unreach(pkt->skb, priv->icmp_code);
+#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
+               else if (priv->family == NFPROTO_IPV6)
+                       nf_send_unreach6(net, pkt->skb, priv->icmp_code,
+                                     pkt->hooknum);
+#endif
+               break;
+       case NFT_REJECT_TCP_RST:
+               if (priv->family == NFPROTO_IPV4)
+                       nf_send_reset(pkt->skb, pkt->hooknum);
+#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
+               else if (priv->family == NFPROTO_IPV6)
+                       nf_send_reset6(net, pkt->skb, pkt->hooknum);
+#endif
+               break;
+       }
+
+       data[NFT_REG_VERDICT].verdict = NF_DROP;
+}
+
+static const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
+       [NFTA_REJECT_TYPE]              = { .type = NLA_U32 },
+       [NFTA_REJECT_ICMP_CODE]         = { .type = NLA_U8 },
+};
+
+static int nft_reject_init(const struct nft_ctx *ctx,
+                          const struct nft_expr *expr,
+                          const struct nlattr * const tb[])
+{
+       struct nft_reject *priv = nft_expr_priv(expr);
+
+       if (tb[NFTA_REJECT_TYPE] == NULL)
+               return -EINVAL;
+
+       priv->family = ctx->afi->family;
+       priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
+       switch (priv->type) {
+       case NFT_REJECT_ICMP_UNREACH:
+               if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
+                       return -EINVAL;
+               priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
+       case NFT_REJECT_TCP_RST:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+       const struct nft_reject *priv = nft_expr_priv(expr);
+
+       if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
+               goto nla_put_failure;
+
+       switch (priv->type) {
+       case NFT_REJECT_ICMP_UNREACH:
+               if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
+                       goto nla_put_failure;
+               break;
+       }
+
+       return 0;
+
+nla_put_failure:
+       return -1;
+}
+
+static struct nft_expr_type nft_reject_type;
+static const struct nft_expr_ops nft_reject_ops = {
+       .type           = &nft_reject_type,
+       .size           = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
+       .eval           = nft_reject_eval,
+       .init           = nft_reject_init,
+       .dump           = nft_reject_dump,
+};
+
+static struct nft_expr_type nft_reject_type __read_mostly = {
+       .name           = "reject",
+       .ops            = &nft_reject_ops,
+       .policy         = nft_reject_policy,
+       .maxattr        = NFTA_REJECT_MAX,
+       .owner          = THIS_MODULE,
+};
+
+static int __init nft_reject_module_init(void)
+{
+       return nft_register_expr(&nft_reject_type);
+}
+
+static void __exit nft_reject_module_exit(void)
+{
+       nft_unregister_expr(&nft_reject_type);
+}
+
+module_init(nft_reject_module_init);
+module_exit(nft_reject_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS_NFT_EXPR("reject");
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