From d877f07112f1e5a247c6b585c971a93895c9f738 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 31 May 2015 18:04:11 +0200 Subject: netfilter: nf_tables: add nft_dup expression This new expression uses the nf_dup engine to clone packets to a given gateway. Unlike xt_TEE, we use an index to indicate output interface which should be fine at this stage. Moreover, change to the preemtion-safe this_cpu_read(nf_skb_duplicated) from nf_dup_ipv{4,6} to silence a lockdep splat. Based on the original tee expression from Arturo Borrero Gonzalez, although this patch has diverted quite a bit from this initial effort due to the change to support maps. Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/Kconfig | 6 +++ net/ipv4/netfilter/Makefile | 1 + net/ipv4/netfilter/nf_dup_ipv4.c | 2 +- net/ipv4/netfilter/nft_dup_ipv4.c | 110 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 118 insertions(+), 1 deletion(-) create mode 100644 net/ipv4/netfilter/nft_dup_ipv4.c (limited to 'net/ipv4/netfilter') diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index 0142ea259d7d..690d27d3f2f9 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -58,6 +58,12 @@ config NFT_REJECT_IPV4 default NFT_REJECT tristate +config NFT_DUP_IPV4 + tristate "IPv4 nf_tables packet duplication support" + select NF_DUP_IPV4 + help + This module enables IPv4 packet duplication support for nf_tables. + endif # NF_TABLES_IPV4 config NF_TABLES_ARP diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 9136ffc2d474..87b073da14c9 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -41,6 +41,7 @@ obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o obj-$(CONFIG_NFT_MASQ_IPV4) += nft_masq_ipv4.o obj-$(CONFIG_NFT_REDIR_IPV4) += nft_redir_ipv4.o +obj-$(CONFIG_NFT_DUP_IPV4) += nft_dup_ipv4.o obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o # generic IP tables diff --git a/net/ipv4/netfilter/nf_dup_ipv4.c b/net/ipv4/netfilter/nf_dup_ipv4.c index eff85ab3f47d..b5bb37564b0e 100644 --- a/net/ipv4/netfilter/nf_dup_ipv4.c +++ b/net/ipv4/netfilter/nf_dup_ipv4.c @@ -69,7 +69,7 @@ void nf_dup_ipv4(struct sk_buff *skb, unsigned int hooknum, { struct iphdr *iph; - if (__this_cpu_read(nf_skb_duplicated)) + if (this_cpu_read(nf_skb_duplicated)) return; /* * Copy the skb, and route the copy. Will later return %XT_CONTINUE for diff --git a/net/ipv4/netfilter/nft_dup_ipv4.c b/net/ipv4/netfilter/nft_dup_ipv4.c new file mode 100644 index 000000000000..25419fbddcb6 --- /dev/null +++ b/net/ipv4/netfilter/nft_dup_ipv4.c @@ -0,0 +1,110 @@ +/* + * Copyright (c) 2015 Pablo Neira Ayuso + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +struct nft_dup_ipv4 { + enum nft_registers sreg_addr:8; + enum nft_registers sreg_dev:8; +}; + +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 = regs->data[priv->sreg_addr], + }; + int oif = regs->data[priv->sreg_dev]; + + nf_dup_ipv4(pkt->skb, pkt->ops->hooknum, &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; + + priv->sreg_addr = nft_parse_register(tb[NFTA_DUP_SREG_ADDR]); + err = nft_validate_register_load(priv->sreg_addr, sizeof(struct in_addr)); + if (err < 0) + return err; + + if (tb[NFTA_DUP_SREG_DEV] != NULL) { + priv->sreg_dev = nft_parse_register(tb[NFTA_DUP_SREG_DEV]); + return nft_validate_register_load(priv->sreg_dev, sizeof(int)); + } + return 0; +} + +static int nft_dup_ipv4_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + struct nft_dup_ipv4 *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_DUP_SREG_ADDR, priv->sreg_addr) || + 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, +}; + +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 "); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup"); -- cgit