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 <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nft_dup.h | 9 +++
include/uapi/linux/netfilter/nf_tables.h | 14 ++++
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 ++++++++++++++++++++++++++++++
net/ipv6/netfilter/Kconfig | 6 ++
net/ipv6/netfilter/Makefile | 1 +
net/ipv6/netfilter/nf_dup_ipv6.c | 2 +-
net/ipv6/netfilter/nft_dup_ipv6.c | 108 +++++++++++++++++++++++++++++
10 files changed, 257 insertions(+), 2 deletions(-)
create mode 100644 include/net/netfilter/nft_dup.h
create mode 100644 net/ipv4/netfilter/nft_dup_ipv4.c
create mode 100644 net/ipv6/netfilter/nft_dup_ipv6.c
diff --git a/include/net/netfilter/nft_dup.h b/include/net/netfilter/nft_dup.h
new file mode 100644
index 0000000..6b84cf6
--- /dev/null
+++ b/include/net/netfilter/nft_dup.h
@@ -0,0 +1,9 @@
+#ifndef _NFT_DUP_H_
+#define _NFT_DUP_H_
+
+struct nft_dup_inet {
+ enum nft_registers sreg_addr:8;
+ enum nft_registers sreg_dev:8;
+};
+
+#endif /* _NFT_DUP_H_ */
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index a99e6a9..2ef35f2 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -936,6 +936,20 @@ enum nft_redir_attributes {
#define NFTA_REDIR_MAX (__NFTA_REDIR_MAX - 1)
/**
+ * enum nft_dup_attributes - nf_tables dup expression netlink attributes
+ *
+ * @NFTA_DUP_SREG_ADDR: source register of address (NLA_U32: nft_registers)
+ * @NFTA_DUP_SREG_DEV: source register of output interface (NLA_U32: nft_register)
+ */
+enum nft_dup_attributes {
+ NFTA_DUP_UNSPEC,
+ NFTA_DUP_SREG_ADDR,
+ NFTA_DUP_SREG_DEV,
+ __NFTA_DUP_MAX
+};
+#define NFTA_DUP_MAX (__NFTA_DUP_MAX - 1)
+
+/**
* enum nft_gen_attributes - nf_tables ruleset generation attributes
*
* @NFTA_GEN_ID: Ruleset generation ID (NLA_U32)
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 0142ea2..690d27d 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 9136ffc..87b073d 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 eff85ab..b5bb375 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 0000000..25419fb
--- /dev/null
+++ b/net/ipv4/netfilter/nft_dup_ipv4.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2015 Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ *
+ * 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 <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 {
+ 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 <pablo@xxxxxxxxxxxxx>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup");
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index 298daf3..96833e4 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -47,6 +47,12 @@ config NFT_REJECT_IPV6
default NFT_REJECT
tristate
+config NFT_DUP_IPV6
+ tristate "IPv6 nf_tables packet duplication support"
+ select NF_DUP_IPV6
+ help
+ This module enables IPv6 packet duplication support for nf_tables.
+
endif # NF_TABLES_IPV6
endif # NF_TABLES
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index dc6c732..b4f7d0b 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_NFT_CHAIN_NAT_IPV6) += nft_chain_nat_ipv6.o
obj-$(CONFIG_NFT_REJECT_IPV6) += nft_reject_ipv6.o
obj-$(CONFIG_NFT_MASQ_IPV6) += nft_masq_ipv6.o
obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redir_ipv6.o
+obj-$(CONFIG_NFT_DUP_IPV6) += nft_dup_ipv6.o
# matches
obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
diff --git a/net/ipv6/netfilter/nf_dup_ipv6.c b/net/ipv6/netfilter/nf_dup_ipv6.c
index 399fdda..d8ab654 100644
--- a/net/ipv6/netfilter/nf_dup_ipv6.c
+++ b/net/ipv6/netfilter/nf_dup_ipv6.c
@@ -63,7 +63,7 @@ static bool nf_dup_ipv6_route(struct sk_buff *skb, const struct in6_addr *gw,
void nf_dup_ipv6(struct sk_buff *skb, unsigned int hooknum,
const struct in6_addr *gw, int oif)
{
- if (__this_cpu_read(nf_skb_duplicated))
+ if (this_cpu_read(nf_skb_duplicated))
return;
skb = pskb_copy(skb, GFP_ATOMIC);
if (skb == NULL)
diff --git a/net/ipv6/netfilter/nft_dup_ipv6.c b/net/ipv6/netfilter/nft_dup_ipv6.c
new file mode 100644
index 0000000..0eaa4f6
--- /dev/null
+++ b/net/ipv6/netfilter/nft_dup_ipv6.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2015 Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ *
+ * 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 <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/ipv6/nf_dup_ipv6.h>
+
+struct nft_dup_ipv6 {
+ enum nft_registers sreg_addr:8;
+ enum nft_registers sreg_dev:8;
+};
+
+static void nft_dup_ipv6_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_dup_ipv6 *priv = nft_expr_priv(expr);
+ struct in6_addr *gw = (struct in6_addr *)®s->data[priv->sreg_addr];
+ int oif = regs->data[priv->sreg_dev];
+
+ nf_dup_ipv6(pkt->skb, pkt->ops->hooknum, gw, oif);
+}
+
+static int nft_dup_ipv6_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_dup_ipv6 *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 in6_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_ipv6_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ struct nft_dup_ipv6 *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_ipv6_type;
+static const struct nft_expr_ops nft_dup_ipv6_ops = {
+ .type = &nft_dup_ipv6_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_dup_ipv6)),
+ .eval = nft_dup_ipv6_eval,
+ .init = nft_dup_ipv6_init,
+ .dump = nft_dup_ipv6_dump,
+};
+
+static const struct nla_policy nft_dup_ipv6_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_ipv6_type __read_mostly = {
+ .family = NFPROTO_IPV6,
+ .name = "dup",
+ .ops = &nft_dup_ipv6_ops,
+ .policy = nft_dup_ipv6_policy,
+ .maxattr = NFTA_DUP_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_dup_ipv6_module_init(void)
+{
+ return nft_register_expr(&nft_dup_ipv6_type);
+}
+
+static void __exit nft_dup_ipv6_module_exit(void)
+{
+ nft_unregister_expr(&nft_dup_ipv6_type);
+}
+
+module_init(nft_dup_ipv6_module_init);
+module_exit(nft_dup_ipv6_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "dup");
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
