diff options
Diffstat (limited to 'net/ipv4/netfilter/nft_dup_ipv4.c')
-rw-r--r-- | net/ipv4/netfilter/nft_dup_ipv4.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/nft_dup_ipv4.c b/net/ipv4/netfilter/nft_dup_ipv4.c new file mode 100644 index 0000000000..a522c3a3be --- /dev/null +++ b/net/ipv4/netfilter/nft_dup_ipv4.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org> + */ + +#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> +#include <net/netfilter/ipv4/nf_dup_ipv4.h> + +struct nft_dup_ipv4 { + u8 sreg_addr; + u8 sreg_dev; +}; + +static void nft_dup_ipv4_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + struct in_addr gw = { + .s_addr = (__force __be32)regs->data[priv->sreg_addr], + }; + int oif = priv->sreg_dev ? regs->data[priv->sreg_dev] : -1; + + nf_dup_ipv4(nft_net(pkt), pkt->skb, nft_hook(pkt), &gw, oif); +} + +static int nft_dup_ipv4_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + int err; + + if (tb[NFTA_DUP_SREG_ADDR] == NULL) + return -EINVAL; + + err = nft_parse_register_load(tb[NFTA_DUP_SREG_ADDR], &priv->sreg_addr, + sizeof(struct in_addr)); + if (err < 0) + return err; + + if (tb[NFTA_DUP_SREG_DEV]) + err = nft_parse_register_load(tb[NFTA_DUP_SREG_DEV], + &priv->sreg_dev, sizeof(int)); + + return err; +} + +static int nft_dup_ipv4_dump(struct sk_buff *skb, + const struct nft_expr *expr, bool reset) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr)) + goto nla_put_failure; + if (priv->sreg_dev && + nft_dump_register(skb, NFTA_DUP_SREG_DEV, priv->sreg_dev)) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_dup_ipv4_type; +static const struct nft_expr_ops nft_dup_ipv4_ops = { + .type = &nft_dup_ipv4_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv4)), + .eval = nft_dup_ipv4_eval, + .init = nft_dup_ipv4_init, + .dump = nft_dup_ipv4_dump, + .reduce = NFT_REDUCE_READONLY, +}; + +static const struct nla_policy nft_dup_ipv4_policy[NFTA_DUP_MAX + 1] = { + [NFTA_DUP_SREG_ADDR] = { .type = NLA_U32 }, + [NFTA_DUP_SREG_DEV] = { .type = NLA_U32 }, +}; + +static struct nft_expr_type nft_dup_ipv4_type __read_mostly = { + .family = NFPROTO_IPV4, + .name = "dup", + .ops = &nft_dup_ipv4_ops, + .policy = nft_dup_ipv4_policy, + .maxattr = NFTA_DUP_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_dup_ipv4_module_init(void) +{ + return nft_register_expr(&nft_dup_ipv4_type); +} + +static void __exit nft_dup_ipv4_module_exit(void) +{ + nft_unregister_expr(&nft_dup_ipv4_type); +} + +module_init(nft_dup_ipv4_module_init); +module_exit(nft_dup_ipv4_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup"); +MODULE_DESCRIPTION("IPv4 nftables packet duplication support"); |