1/*
  2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License version 2 as
  6 * published by the Free Software Foundation.
  7 *
  8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
  9 */
 10
 11#include <linux/kernel.h>
 12#include <linux/init.h>
 13#include <linux/module.h>
 14#include <linux/netlink.h>
 15#include <linux/netfilter.h>
 16#include <linux/netfilter/nf_tables.h>
 17#include <net/netfilter/nf_tables_core.h>
 18#include <net/netfilter/nf_tables.h>
 19
 20struct nft_immediate_expr {
 21	struct nft_data		data;
 22	enum nft_registers	dreg:8;
 23	u8			dlen;
 24};
 25
 26static void nft_immediate_eval(const struct nft_expr *expr,
 27			       struct nft_regs *regs,
 28			       const struct nft_pktinfo *pkt)
 29{
 30	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 31
 32	nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
 33}
 34
 35static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
 36	[NFTA_IMMEDIATE_DREG]	= { .type = NLA_U32 },
 37	[NFTA_IMMEDIATE_DATA]	= { .type = NLA_NESTED },
 38};
 39
 40static int nft_immediate_init(const struct nft_ctx *ctx,
 41			      const struct nft_expr *expr,
 42			      const struct nlattr * const tb[])
 43{
 44	struct nft_immediate_expr *priv = nft_expr_priv(expr);
 45	struct nft_data_desc desc;
 46	int err;
 47
 48	if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
 49	    tb[NFTA_IMMEDIATE_DATA] == NULL)
 50		return -EINVAL;
 51
 52	err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
 53			    tb[NFTA_IMMEDIATE_DATA]);
 54	if (err < 0)
 55		return err;
 56
 57	priv->dlen = desc.len;
 58
 59	priv->dreg = nft_parse_register(tb[NFTA_IMMEDIATE_DREG]);
 60	err = nft_validate_register_store(ctx, priv->dreg, &priv->data,
 61					  desc.type, desc.len);
 62	if (err < 0)
 63		goto err1;
 64
 65	return 0;
 66
 67err1:
 68	nft_data_uninit(&priv->data, desc.type);
 69	return err;
 70}
 71
 72static void nft_immediate_destroy(const struct nft_ctx *ctx,
 73				  const struct nft_expr *expr)
 74{
 75	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 76	return nft_data_uninit(&priv->data, nft_dreg_to_type(priv->dreg));
 77}
 78
 79static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
 80{
 81	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 82
 83	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
 84		goto nla_put_failure;
 85
 86	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
 87			     nft_dreg_to_type(priv->dreg), priv->dlen);
 88
 89nla_put_failure:
 90	return -1;
 91}
 92
 93static int nft_immediate_validate(const struct nft_ctx *ctx,
 94				  const struct nft_expr *expr,
 95				  const struct nft_data **data)
 96{
 97	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 98
 99	if (priv->dreg == NFT_REG_VERDICT)
100		*data = &priv->data;
101
102	return 0;
103}
104
105static const struct nft_expr_ops nft_imm_ops = {
106	.type		= &nft_imm_type,
107	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
108	.eval		= nft_immediate_eval,
109	.init		= nft_immediate_init,
110	.destroy	= nft_immediate_destroy,
111	.dump		= nft_immediate_dump,
112	.validate	= nft_immediate_validate,
113};
114
115struct nft_expr_type nft_imm_type __read_mostly = {
116	.name		= "immediate",
117	.ops		= &nft_imm_ops,
118	.policy		= nft_immediate_policy,
119	.maxattr	= NFTA_IMMEDIATE_MAX,
120	.owner		= THIS_MODULE,
121};