nft_fib.c
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/*
* 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.
*
* Generic part shared by ipv4 and ipv6 backends.
*/
#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_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_fib.h>
const struct nla_policy nft_fib_policy[NFTA_FIB_MAX + 1] = {
[NFTA_FIB_DREG] = { .type = NLA_U32 },
[NFTA_FIB_RESULT] = { .type = NLA_U32 },
[NFTA_FIB_FLAGS] = { .type = NLA_U32 },
};
EXPORT_SYMBOL(nft_fib_policy);
#define NFTA_FIB_F_ALL (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR | \
NFTA_FIB_F_MARK | NFTA_FIB_F_IIF | NFTA_FIB_F_OIF | \
NFTA_FIB_F_PRESENT)
int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nft_data **data)
{
const struct nft_fib *priv = nft_expr_priv(expr);
unsigned int hooks;
switch (priv->result) {
case NFT_FIB_RESULT_OIF: /* fallthrough */
case NFT_FIB_RESULT_OIFNAME:
hooks = (1 << NF_INET_PRE_ROUTING);
break;
case NFT_FIB_RESULT_ADDRTYPE:
if (priv->flags & NFTA_FIB_F_IIF)
hooks = (1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_LOCAL_IN) |
(1 << NF_INET_FORWARD);
else if (priv->flags & NFTA_FIB_F_OIF)
hooks = (1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_POST_ROUTING) |
(1 << NF_INET_FORWARD);
else
hooks = (1 << NF_INET_LOCAL_IN) |
(1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_FORWARD) |
(1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_POST_ROUTING);
break;
default:
return -EINVAL;
}
return nft_chain_validate_hooks(ctx->chain, hooks);
}
EXPORT_SYMBOL_GPL(nft_fib_validate);
int nft_fib_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_fib *priv = nft_expr_priv(expr);
unsigned int len;
int err;
if (!tb[NFTA_FIB_DREG] || !tb[NFTA_FIB_RESULT] || !tb[NFTA_FIB_FLAGS])
return -EINVAL;
priv->flags = ntohl(nla_get_be32(tb[NFTA_FIB_FLAGS]));
if (priv->flags == 0 || (priv->flags & ~NFTA_FIB_F_ALL))
return -EINVAL;
if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) ==
(NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR))
return -EINVAL;
if ((priv->flags & (NFTA_FIB_F_IIF | NFTA_FIB_F_OIF)) ==
(NFTA_FIB_F_IIF | NFTA_FIB_F_OIF))
return -EINVAL;
if ((priv->flags & (NFTA_FIB_F_SADDR | NFTA_FIB_F_DADDR)) == 0)
return -EINVAL;
priv->result = ntohl(nla_get_be32(tb[NFTA_FIB_RESULT]));
priv->dreg = nft_parse_register(tb[NFTA_FIB_DREG]);
switch (priv->result) {
case NFT_FIB_RESULT_OIF:
if (priv->flags & NFTA_FIB_F_OIF)
return -EINVAL;
len = sizeof(int);
break;
case NFT_FIB_RESULT_OIFNAME:
if (priv->flags & NFTA_FIB_F_OIF)
return -EINVAL;
len = IFNAMSIZ;
break;
case NFT_FIB_RESULT_ADDRTYPE:
len = sizeof(u32);
break;
default:
return -EINVAL;
}
err = nft_validate_register_store(ctx, priv->dreg, NULL,
NFT_DATA_VALUE, len);
if (err < 0)
return err;
return 0;
}
EXPORT_SYMBOL_GPL(nft_fib_init);
int nft_fib_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_fib *priv = nft_expr_priv(expr);
if (nft_dump_register(skb, NFTA_FIB_DREG, priv->dreg))
return -1;
if (nla_put_be32(skb, NFTA_FIB_RESULT, htonl(priv->result)))
return -1;
if (nla_put_be32(skb, NFTA_FIB_FLAGS, htonl(priv->flags)))
return -1;
return 0;
}
EXPORT_SYMBOL_GPL(nft_fib_dump);
void nft_fib_store_result(void *reg, const struct nft_fib *priv,
const struct nft_pktinfo *pkt, int index)
{
struct net_device *dev;
u32 *dreg = reg;
switch (priv->result) {
case NFT_FIB_RESULT_OIF:
*dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index;
break;
case NFT_FIB_RESULT_OIFNAME:
dev = dev_get_by_index_rcu(nft_net(pkt), index);
if (priv->flags & NFTA_FIB_F_PRESENT)
*dreg = !!dev;
else
strncpy(reg, dev ? dev->name : "", IFNAMSIZ);
break;
default:
WARN_ON_ONCE(1);
*dreg = 0;
break;
}
}
EXPORT_SYMBOL_GPL(nft_fib_store_result);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");