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/*
* 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/dst.h>
#include <net/sock.h>
#include <net/tcp_states.h> /* for TCP_TIME_WAIT */
#include <net/netfilter/nf_tables.h>
struct nft_meta {
enum nft_meta_keys key:8;
enum nft_registers dreg:8;
};
static void nft_meta_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
const struct nft_meta *priv = nft_expr_priv(expr);
const struct sk_buff *skb = pkt->skb;
const struct net_device *in = pkt->in, *out = pkt->out;
struct nft_data *dest = &data[priv->dreg];
switch (priv->key) {
case NFT_META_LEN:
dest->data[0] = skb->len;
break;
case NFT_META_PROTOCOL:
*(__be16 *)dest->data = skb->protocol;
break;
case NFT_META_PRIORITY:
dest->data[0] = skb->priority;
break;
case NFT_META_MARK:
dest->data[0] = skb->mark;
break;
case NFT_META_IIF:
if (in == NULL)
goto err;
dest->data[0] = in->ifindex;
break;
case NFT_META_OIF:
if (out == NULL)
goto err;
dest->data[0] = out->ifindex;
break;
case NFT_META_IIFNAME:
if (in == NULL)
goto err;
strncpy((char *)dest->data, in->name, sizeof(dest->data));
break;
case NFT_META_OIFNAME:
if (out == NULL)
goto err;
strncpy((char *)dest->data, out->name, sizeof(dest->data));
break;
case NFT_META_IIFTYPE:
if (in == NULL)
goto err;
*(u16 *)dest->data = in->type;
break;
case NFT_META_OIFTYPE:
if (out == NULL)
goto err;
*(u16 *)dest->data = out->type;
break;
case NFT_META_SKUID:
if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT)
goto err;
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket == NULL ||
skb->sk->sk_socket->file == NULL) {
read_unlock_bh(&skb->sk->sk_callback_lock);
goto err;
}
dest->data[0] =
from_kuid_munged(&init_user_ns,
skb->sk->sk_socket->file->f_cred->fsuid);
read_unlock_bh(&skb->sk->sk_callback_lock);
break;
case NFT_META_SKGID:
if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT)
goto err;
read_lock_bh(&skb->sk->sk_callback_lock);
if (skb->sk->sk_socket == NULL ||
skb->sk->sk_socket->file == NULL) {
read_unlock_bh(&skb->sk->sk_callback_lock);
goto err;
}
dest->data[0] =
from_kgid_munged(&init_user_ns,
skb->sk->sk_socket->file->f_cred->fsgid);
read_unlock_bh(&skb->sk->sk_callback_lock);
break;
#ifdef CONFIG_NET_CLS_ROUTE
case NFT_META_RTCLASSID: {
const struct dst_entry *dst = skb_dst(skb);
if (dst == NULL)
goto err;
dest->data[0] = dst->tclassid;
break;
}
#endif
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
dest->data[0] = skb->secmark;
break;
#endif
default:
WARN_ON(1);
goto err;
}
return;
err:
data[NFT_REG_VERDICT].verdict = NFT_BREAK;
}
static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
[NFTA_META_DREG] = { .type = NLA_U32 },
[NFTA_META_KEY] = { .type = NLA_U32 },
};
static int nft_meta_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_meta *priv = nft_expr_priv(expr);
int err;
if (tb[NFTA_META_DREG] == NULL ||
tb[NFTA_META_KEY] == NULL)
return -EINVAL;
priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
switch (priv->key) {
case NFT_META_LEN:
case NFT_META_PROTOCOL:
case NFT_META_PRIORITY:
case NFT_META_MARK:
case NFT_META_IIF:
case NFT_META_OIF:
case NFT_META_IIFNAME:
case NFT_META_OIFNAME:
case NFT_META_IIFTYPE:
case NFT_META_OIFTYPE:
case NFT_META_SKUID:
case NFT_META_SKGID:
#ifdef CONFIG_NET_CLS_ROUTE
case NFT_META_RTCLASSID:
#endif
#ifdef CONFIG_NETWORK_SECMARK
case NFT_META_SECMARK:
#endif
break;
default:
return -EOPNOTSUPP;
}
priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_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_meta_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_meta *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_META_DREG, htonl(priv->dreg)))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct nft_expr_type nft_meta_type;
static const struct nft_expr_ops nft_meta_ops = {
.type = &nft_meta_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
.eval = nft_meta_eval,
.init = nft_meta_init,
.dump = nft_meta_dump,
};
static struct nft_expr_type nft_meta_type __read_mostly = {
.name = "meta",
.ops = &nft_meta_ops,
.policy = nft_meta_policy,
.maxattr = NFTA_META_MAX,
.owner = THIS_MODULE,
};
static int __init nft_meta_module_init(void)
{
return nft_register_expr(&nft_meta_type);
}
static void __exit nft_meta_module_exit(void)
{
nft_unregister_expr(&nft_meta_type);
}
module_init(nft_meta_module_init);
module_exit(nft_meta_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("meta");
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