netfilter: nft_reject: split up reject module into IPv4 and IPv6 specifc parts

Currently the nft_reject module depends on symbols from ipv6. This is
wrong since no generic module should force IPv6 support to be loaded.
Split up the module into AF-specific and a generic part.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 9 insertions, 81 deletions

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index c37467562fd0..ed8b50e62276 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -513,7 +513,6 @@ config NFT_QUEUE
 
 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"
 	help
diff --git a/net/netfilter/nft_reject.c b/net/netfilter/nft_reject.c
index 5e204711d704..f3448c296446 100644
--- a/net/netfilter/nft_reject.c
+++ b/net/netfilter/nft_reject.c
@@ -16,65 +16,23 @@
 #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>
+#include <net/netfilter/nft_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);
-#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
-	struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
-#endif
-	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->ops->hooknum);
-#endif
-		break;
-	case NFT_REJECT_TCP_RST:
-		if (priv->family == NFPROTO_IPV4)
-			nf_send_reset(pkt->skb, pkt->ops->hooknum);
-#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
-		else if (priv->family == NFPROTO_IPV6)
-			nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
-#endif
-		break;
-	}
-
-	data[NFT_REG_VERDICT].verdict = NF_DROP;
-}
-
-static const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
+const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
 	[NFTA_REJECT_TYPE]		= { .type = NLA_U32 },
 	[NFTA_REJECT_ICMP_CODE]		= { .type = NLA_U8 },
 };
+EXPORT_SYMBOL_GPL(nft_reject_policy);
 
-static int nft_reject_init(const struct nft_ctx *ctx,
-			   const struct nft_expr *expr,
-			   const struct nlattr * const tb[])
+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:
@@ -89,8 +47,9 @@ static int nft_reject_init(const struct nft_ctx *ctx,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(nft_reject_init);
 
-static int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
+int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
 {
 	const struct nft_reject *priv = nft_expr_priv(expr);
 
@@ -109,37 +68,7 @@ static int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
 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);
+EXPORT_SYMBOL_GPL(nft_reject_dump);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
-MODULE_ALIAS_NFT_EXPR("reject");