netfilter: nft_reject: support for IPv6 and TCP reset

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>

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 40d5607..9d3d69a 100644 (file)
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -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"

diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 19df72b..c16be9d 100644 (file)
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -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/netfilter/Kconfig b/net/netfilter/Kconfig
index 01f9f64..a1dec61 100644 (file)
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -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

diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index dcc818a..39e4a7b 100644 (file)
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -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/ipv4/netfilter/nft_reject_ipv4.c b/net/netfilter/nft_reject.c
similarity index 77%
rename from net/ipv4/netfilter/nft_reject_ipv4.c
rename to net/netfilter/nft_reject.c
index fff5ba1..0d690d4 100644 (file)
--- a/net/ipv4/netfilter/nft_reject_ipv4.c
+++ b/net/netfilter/nft_reject.c
@@ -1,5 +1,6 @@
 /*
  * 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
@@ -16,10 +17,16 @@
 #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,
@@ -27,12 +34,25 @@ static void nft_reject_eval(const struct nft_expr *expr,
                              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:
-               icmp_send(pkt->skb, ICMP_DEST_UNREACH, priv->icmp_code, 0);
+               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;
        }
 
@@ -53,6 +73,7 @@ static int nft_reject_init(const struct nft_ctx *ctx,
        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:
@@ -72,7 +93,7 @@ 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))
+       if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
                goto nla_put_failure;
 
        switch (priv->type) {