1 files changed, 133 insertions, 0 deletions
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c
new file mode 100644
index 00000000000..55c939f5371
--- /dev/null
+++ b/net/netfilter/nft_exthdr.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2008 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>
+// FIXME:
+#include <net/ipv6.h>
+
+struct nft_exthdr {
+	u8			type;
+	u8			offset;
+	u8			len;
+	enum nft_registers	dreg:8;
+};
+
+static void nft_exthdr_eval(const struct nft_expr *expr,
+			    struct nft_data data[NFT_REG_MAX + 1],
+			    const struct nft_pktinfo *pkt)
+{
+	struct nft_exthdr *priv = nft_expr_priv(expr);
+	struct nft_data *dest = &data[priv->dreg];
+	unsigned int offset = 0;
+	int err;
+
+	err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
+	if (err < 0)
+		goto err;
+	offset += priv->offset;
+
+	if (skb_copy_bits(pkt->skb, offset, dest->data, priv->len) < 0)
+		goto err;
+	return;
+err:
+	data[NFT_REG_VERDICT].verdict = NFT_BREAK;
+}
+
+static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
+	[NFTA_EXTHDR_DREG]		= { .type = NLA_U32 },
+	[NFTA_EXTHDR_TYPE]		= { .type = NLA_U8 },
+	[NFTA_EXTHDR_OFFSET]		= { .type = NLA_U32 },
+	[NFTA_EXTHDR_LEN]		= { .type = NLA_U32 },
+};
+
+static int nft_exthdr_init(const struct nft_ctx *ctx,
+			   const struct nft_expr *expr,
+			   const struct nlattr * const tb[])
+{
+	struct nft_exthdr *priv = nft_expr_priv(expr);
+	int err;
+
+	if (tb[NFTA_EXTHDR_DREG] == NULL ||
+	    tb[NFTA_EXTHDR_TYPE] == NULL ||
+	    tb[NFTA_EXTHDR_OFFSET] == NULL ||
+	    tb[NFTA_EXTHDR_LEN] == NULL)
+		return -EINVAL;
+
+	priv->type   = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
+	priv->offset = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OFFSET]));
+	priv->len    = ntohl(nla_get_be32(tb[NFTA_EXTHDR_LEN]));
+	if (priv->len == 0 ||
+	    priv->len > FIELD_SIZEOF(struct nft_data, data))
+		return -EINVAL;
+
+	priv->dreg = ntohl(nla_get_be32(tb[NFTA_EXTHDR_DREG]));
+	err = nft_validate_output_register(priv->dreg);
+	if (err < 0)
+		return err;
+	return nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
+}
+
+static int nft_exthdr_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+	const struct nft_exthdr *priv = nft_expr_priv(expr);
+
+	if (nla_put_be32(skb, NFTA_EXTHDR_DREG, htonl(priv->dreg)))
+		goto nla_put_failure;
+	if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
+		goto nla_put_failure;
+	if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
+		goto nla_put_failure;
+	if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static struct nft_expr_type nft_exthdr_type;
+static const struct nft_expr_ops nft_exthdr_ops = {
+	.type		= &nft_exthdr_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
+	.eval		= nft_exthdr_eval,
+	.init		= nft_exthdr_init,
+	.dump		= nft_exthdr_dump,
+};
+
+static struct nft_expr_type nft_exthdr_type __read_mostly = {
+	.name		= "exthdr",
+	.ops		= &nft_exthdr_ops,
+	.policy		= nft_exthdr_policy,
+	.maxattr	= NFTA_EXTHDR_MAX,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nft_exthdr_module_init(void)
+{
+	return nft_register_expr(&nft_exthdr_type);
+}
+
+static void __exit nft_exthdr_module_exit(void)
+{
+	nft_unregister_expr(&nft_exthdr_type);
+}
+
+module_init(nft_exthdr_module_init);
+module_exit(nft_exthdr_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS_NFT_EXPR("exthdr");