brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

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 <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2015-05-31 18:04:11 +02:00
parent bbde9fc182
commit d877f07112
10 changed files with 257 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/net/netfilter/nft_dup.h Normal file
View File

@ -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_ */

14
include/uapi/linux/netfilter/nf_tables.h
View File

@ -935,6 +935,20 @@ 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
*

6
net/ipv4/netfilter/Kconfig
View File

@ -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

1
net/ipv4/netfilter/Makefile
View File

@ -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

2
net/ipv4/netfilter/nf_dup_ipv4.c
View File

@ -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

110
net/ipv4/netfilter/nft_dup_ipv4.c Normal file
View File

@ -0,0 +1,110 @@
/*
* Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
*
* 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@netfilter.org>");
MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "dup");

6
net/ipv6/netfilter/Kconfig
View File

@ -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

1
net/ipv6/netfilter/Makefile
View File

@ -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

2
net/ipv6/netfilter/nf_dup_ipv6.c
View File

@ -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)

108
net/ipv6/netfilter/nft_dup_ipv6.c Normal file
View File

@ -0,0 +1,108 @@
/*
* Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
*
* 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 *)&regs->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@netfilter.org>");
MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "dup");