diff options
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/Kconfig | 10 | ||||
| -rw-r--r-- | net/netfilter/Makefile | 1 | ||||
| -rw-r--r-- | net/netfilter/nf_nat_redirect.c | 127 | ||||
| -rw-r--r-- | net/netfilter/xt_REDIRECT.c | 3 |
4 files changed, 137 insertions, 4 deletions
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 57f15a9..b02660f 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -411,6 +411,13 @@ config NF_NAT_TFTP depends on NF_CONNTRACK && NF_NAT default NF_NAT && NF_CONNTRACK_TFTP +config NF_NAT_REDIRECT + tristate "IPv4/IPv6 redirect support" + depends on NF_NAT + help + This is the kernel functionality to redirect packets to local + machine through NAT. + config NETFILTER_SYNPROXY tristate @@ -844,8 +851,7 @@ config NETFILTER_XT_TARGET_RATEEST config NETFILTER_XT_TARGET_REDIRECT tristate "REDIRECT target support" depends on NF_NAT - select NF_NAT_REDIRECT_IPV4 if NF_NAT_IPV4 - select NF_NAT_REDIRECT_IPV6 if NF_NAT_IPV6 + select NF_NAT_REDIRECT ---help--- REDIRECT is a special case of NAT: all incoming connections are mapped onto the incoming interface's address, causing the packets to diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index f3eb468..89f73a9 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -51,6 +51,7 @@ nf_nat-y := nf_nat_core.o nf_nat_proto_unknown.o nf_nat_proto_common.o \ obj-$(CONFIG_NF_LOG_COMMON) += nf_log_common.o obj-$(CONFIG_NF_NAT) += nf_nat.o +obj-$(CONFIG_NF_NAT_REDIRECT) += nf_nat_redirect.o # NAT protocols (nf_nat) obj-$(CONFIG_NF_NAT_PROTO_DCCP) += nf_nat_proto_dccp.o diff --git a/net/netfilter/nf_nat_redirect.c b/net/netfilter/nf_nat_redirect.c new file mode 100644 index 0000000..97b75f9 --- /dev/null +++ b/net/netfilter/nf_nat_redirect.c @@ -0,0 +1,127 @@ +/* + * (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> + * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> + * + * 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. + * + * Based on Rusty Russell's IPv4 REDIRECT target. Development of IPv6 + * NAT funded by Astaro. + */ + +#include <linux/if.h> +#include <linux/inetdevice.h> +#include <linux/ip.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/netfilter.h> +#include <linux/types.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/netfilter/x_tables.h> +#include <net/addrconf.h> +#include <net/checksum.h> +#include <net/protocol.h> +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/nf_nat_redirect.h> + +unsigned int +nf_nat_redirect_ipv4(struct sk_buff *skb, + const struct nf_nat_ipv4_multi_range_compat *mr, + unsigned int hooknum) +{ + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + __be32 newdst; + struct nf_nat_range newrange; + + NF_CT_ASSERT(hooknum == NF_INET_PRE_ROUTING || + hooknum == NF_INET_LOCAL_OUT); + + ct = nf_ct_get(skb, &ctinfo); + NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)); + + /* Local packets: make them go to loopback */ + if (hooknum == NF_INET_LOCAL_OUT) { + newdst = htonl(0x7F000001); + } else { + struct in_device *indev; + struct in_ifaddr *ifa; + + newdst = 0; + + rcu_read_lock(); + indev = __in_dev_get_rcu(skb->dev); + if (indev != NULL) { + ifa = indev->ifa_list; + newdst = ifa->ifa_local; + } + rcu_read_unlock(); + + if (!newdst) + return NF_DROP; + } + + /* Transfer from original range. */ + memset(&newrange.min_addr, 0, sizeof(newrange.min_addr)); + memset(&newrange.max_addr, 0, sizeof(newrange.max_addr)); + newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS; + newrange.min_addr.ip = newdst; + newrange.max_addr.ip = newdst; + newrange.min_proto = mr->range[0].min; + newrange.max_proto = mr->range[0].max; + + /* Hand modified range to generic setup. */ + return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST); +} +EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv4); + +static const struct in6_addr loopback_addr = IN6ADDR_LOOPBACK_INIT; + +unsigned int +nf_nat_redirect_ipv6(struct sk_buff *skb, const struct nf_nat_range *range, + unsigned int hooknum) +{ + struct nf_nat_range newrange; + struct in6_addr newdst; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + if (hooknum == NF_INET_LOCAL_OUT) { + newdst = loopback_addr; + } else { + struct inet6_dev *idev; + struct inet6_ifaddr *ifa; + bool addr = false; + + rcu_read_lock(); + idev = __in6_dev_get(skb->dev); + if (idev != NULL) { + list_for_each_entry(ifa, &idev->addr_list, if_list) { + newdst = ifa->addr; + addr = true; + break; + } + } + rcu_read_unlock(); + + if (!addr) + return NF_DROP; + } + + newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; + newrange.min_addr.in6 = newdst; + newrange.max_addr.in6 = newdst; + newrange.min_proto = range->min_proto; + newrange.max_proto = range->max_proto; + + return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_DST); +} +EXPORT_SYMBOL_GPL(nf_nat_redirect_ipv6); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); diff --git a/net/netfilter/xt_REDIRECT.c b/net/netfilter/xt_REDIRECT.c index b6ec67e..03f0b37 100644 --- a/net/netfilter/xt_REDIRECT.c +++ b/net/netfilter/xt_REDIRECT.c @@ -26,8 +26,7 @@ #include <net/checksum.h> #include <net/protocol.h> #include <net/netfilter/nf_nat.h> -#include <net/netfilter/ipv4/nf_nat_redirect.h> -#include <net/netfilter/ipv6/nf_nat_redirect.h> +#include <net/netfilter/nf_nat_redirect.h> static unsigned int redirect_tg6(struct sk_buff *skb, const struct xt_action_param *par) |
