This allows us to reuse the existing code from nf_tables. Based on original
work from Arturo Borrero Gonzalez.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/ipv4/nf_tee_ipv4.h | 9 ++
include/net/netfilter/ipv6/nf_tee_ipv6.h | 9 ++
include/net/netfilter/nf_tee.h | 23 +++
include/uapi/linux/netfilter/xt_TEE.h | 2 +-
net/ipv4/netfilter/Kconfig | 7 +
net/ipv4/netfilter/Makefile | 2 +
net/ipv4/netfilter/nf_tee_ipv4.c | 115 +++++++++++++++
net/ipv6/netfilter/Kconfig | 7 +
net/ipv6/netfilter/Makefile | 2 +
net/ipv6/netfilter/nf_tee_ipv6.c | 89 +++++++++++
net/netfilter/Kconfig | 10 ++
net/netfilter/Makefile | 2 +
net/netfilter/nf_tee.c | 98 +++++++++++++
net/netfilter/xt_TEE.c | 236 ++----------------------------
14 files changed, 388 insertions(+), 223 deletions(-)
create mode 100644 include/net/netfilter/ipv4/nf_tee_ipv4.h
create mode 100644 include/net/netfilter/ipv6/nf_tee_ipv6.h
create mode 100644 include/net/netfilter/nf_tee.h
create mode 100644 net/ipv4/netfilter/nf_tee_ipv4.c
create mode 100644 net/ipv6/netfilter/nf_tee_ipv6.c
create mode 100644 net/netfilter/nf_tee.c
diff --git a/include/net/netfilter/ipv4/nf_tee_ipv4.h b/include/net/netfilter/ipv4/nf_tee_ipv4.h
new file mode 100644
index 0000000..434e561
--- /dev/null
+++ b/include/net/netfilter/ipv4/nf_tee_ipv4.h
@@ -0,0 +1,9 @@
+#ifndef _NF_TEE_IPV4_H_
+#define _NF_TEE_IPV4_H_
+
+#include <net/netfilter/nf_tee.h>
+
+unsigned int nf_tee_ipv4(struct sk_buff *skb, const struct nf_tee *tee,
+ unsigned int hooknum);
+
+#endif /* _NF_TEE_IPV4_H_ */
diff --git a/include/net/netfilter/ipv6/nf_tee_ipv6.h b/include/net/netfilter/ipv6/nf_tee_ipv6.h
new file mode 100644
index 0000000..842cbcf
--- /dev/null
+++ b/include/net/netfilter/ipv6/nf_tee_ipv6.h
@@ -0,0 +1,9 @@
+#ifndef _NF_TEE_IPV6_H_
+#define _NF_TEE_IPV6_H_
+
+#include <net/netfilter/nf_tee.h>
+
+unsigned int nf_tee_ipv6(struct sk_buff *skb, const struct nf_tee *tee,
+ unsigned int hooknum);
+
+#endif /* _NF_TEE_IPV6_H_ */
diff --git a/include/net/netfilter/nf_tee.h b/include/net/netfilter/nf_tee.h
new file mode 100644
index 0000000..7a93cb1
--- /dev/null
+++ b/include/net/netfilter/nf_tee.h
@@ -0,0 +1,23 @@
+#ifndef _NF_TEE_H_
+#define _NF_TEE_H_
+
+#include <linux/netfilter.h>
+#include <linux/if.h>
+
+struct nf_tee {
+ union nf_inet_addr gw;
+ char oifname[IFNAMSIZ];
+ int oif;
+ struct notifier_block notifier;
+};
+
+struct net *nf_tee_pick_net(struct sk_buff *skb);
+int nf_tee_init(struct nf_tee *tee, union nf_inet_addr gw, const char *oifname);
+void nf_tee_fini(struct nf_tee *tee);
+
+static inline bool nf_tee_has_notifier(const struct nf_tee *tee)
+{
+ return tee->notifier.notifier_call != NULL;
+}
+
+#endif
diff --git a/include/uapi/linux/netfilter/xt_TEE.h b/include/uapi/linux/netfilter/xt_TEE.h
index 5c21d5c..754e43f 100644
--- a/include/uapi/linux/netfilter/xt_TEE.h
+++ b/include/uapi/linux/netfilter/xt_TEE.h
@@ -6,7 +6,7 @@ struct xt_tee_tginfo {
char oif[16];
/* used internally by the kernel */
- struct xt_tee_priv *priv __attribute__((aligned(8)));
+ struct nf_tee *priv __attribute__((aligned(8)));
};
#endif /* _XT_TEE_TARGET_H */
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 2199a5d..2153bb2 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -67,6 +67,13 @@ config NF_TABLES_ARP
endif # NF_TABLES
+config NF_TEE_IPV4
+ tristate "Netfilter IPv4 packet cloning to alternate destination"
+ select NF_TEE
+ help
+ This option enables the nf_tee_ipv4 core, which clones an IPv4 packet
+ to be rerouted to another destination.
+
config NF_LOG_ARP
tristate "ARP packet logging"
default m if NETFILTER_ADVANCED=n
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 7fe6c70..6b492de 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -70,3 +70,5 @@ obj-$(CONFIG_IP_NF_ARP_MANGLE) += arpt_mangle.o
# just filtering instance of ARP tables for now
obj-$(CONFIG_IP_NF_ARPFILTER) += arptable_filter.o
+
+obj-$(CONFIG_NF_TEE_IPV4) += nf_tee_ipv4.o
diff --git a/net/ipv4/netfilter/nf_tee_ipv4.c b/net/ipv4/netfilter/nf_tee_ipv4.c
new file mode 100644
index 0000000..2dcc1a8
--- /dev/null
+++ b/net/ipv4/netfilter/nf_tee_ipv4.c
@@ -0,0 +1,115 @@
+/*
+ * (C) 2007 by Sebastian Claßen
+ * (C) 2007-2010 by Jan Engelhardt
+ *
+ * Extracted from xt_TEE.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 or later, as
+ * published by the Free Software Foundation.
+ */
+#include <linux/ip.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/route.h>
+#include <linux/skbuff.h>
+#include <net/checksum.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/netfilter/nf_tee.h>
+#include <net/netfilter/ipv4/nf_tee_ipv4.h>
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+# define WITH_CONNTRACK 1
+# include <net/netfilter/nf_conntrack.h>
+#endif
+
+static DEFINE_PER_CPU(bool, tee_active);
+
+static bool nf_tee_ipv4_route(struct sk_buff *skb, const struct nf_tee *tee)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+ struct net *net = nf_tee_pick_net(skb);
+ struct rtable *rt;
+ struct flowi4 fl4;
+
+ memset(&fl4, 0, sizeof(fl4));
+ if (nf_tee_has_notifier(tee)) {
+ if (tee->oif == -1)
+ return false;
+
+ fl4.flowi4_oif = tee->oif;
+ }
+ fl4.daddr = tee->gw.ip;
+ fl4.flowi4_tos = RT_TOS(iph->tos);
+ fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
+ fl4.flowi4_flags = FLOWI_FLAG_KNOWN_NH;
+ rt = ip_route_output_key(net, &fl4);
+ if (IS_ERR(rt))
+ return false;
+
+ skb_dst_drop(skb);
+ skb_dst_set(skb, &rt->dst);
+ skb->dev = rt->dst.dev;
+ skb->protocol = htons(ETH_P_IP);
+
+ return true;
+}
+
+unsigned int nf_tee_ipv4(struct sk_buff *skb, const struct nf_tee *tee,
+ unsigned int hooknum)
+{
+ struct iphdr *iph;
+
+ if (__this_cpu_read(tee_active))
+ return XT_CONTINUE;
+ /*
+ * Copy the skb, and route the copy. Will later return %XT_CONTINUE for
+ * the original skb, which should continue on its way as if nothing has
+ * happened. The copy should be independently delivered to the TEE
+ * --gateway.
+ */
+ skb = pskb_copy(skb, GFP_ATOMIC);
+ if (skb == NULL)
+ return XT_CONTINUE;
+
+#ifdef WITH_CONNTRACK
+ /* Avoid counting cloned packets towards the original connection. */
+ nf_conntrack_put(skb->nfct);
+ skb->nfct = &nf_ct_untracked_get()->ct_general;
+ skb->nfctinfo = IP_CT_NEW;
+ nf_conntrack_get(skb->nfct);
+#endif
+ /*
+ * If we are in PREROUTING/INPUT, the checksum must be recalculated
+ * since the length could have changed as a result of defragmentation.
+ *
+ * We also decrease the TTL to mitigate potential TEE loops
+ * between two hosts.
+ *
+ * Set %IP_DF so that the original source is notified of a potentially
+ * decreased MTU on the clone route. IPv6 does this too.
+ */
+ iph = ip_hdr(skb);
+ iph->frag_off |= htons(IP_DF);
+ if (hooknum == NF_INET_PRE_ROUTING ||
+ hooknum == NF_INET_LOCAL_IN)
+ --iph->ttl;
+ ip_send_check(iph);
+
+ if (nf_tee_ipv4_route(skb, tee)) {
+ __this_cpu_write(tee_active, true);
+ ip_local_out(skb);
+ __this_cpu_write(tee_active, false);
+ } else {
+ kfree_skb(skb);
+ }
+ return XT_CONTINUE;
+}
+EXPORT_SYMBOL_GPL(nf_tee_ipv4);
+
+MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@xxxxxxxxxx>");
+MODULE_AUTHOR("Jan Engelhardt <jengelh@xxxxxxxxxx>");
+MODULE_DESCRIPTION("nf_tee_ipv4: Reroute IPv4 packet copy");
+MODULE_LICENSE("GPL");
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index b552cf0..92c37bb 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -59,6 +59,13 @@ config NF_LOG_IPV6
default m if NETFILTER_ADVANCED=n
select NF_LOG_COMMON
+config NF_TEE_IPV6
+ tristate "Netfilter IPv6 packet cloning to alternate destination"
+ select NF_TEE
+ help
+ This option enables the nf_tee_ipv6 core, which clone an IPv6 packet
+ to be rerouted to another destination.
+
config NF_NAT_IPV6
tristate "IPv6 NAT"
depends on NF_CONNTRACK_IPV6
diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile
index c36e0a5..b3a2946 100644
--- a/net/ipv6/netfilter/Makefile
+++ b/net/ipv6/netfilter/Makefile
@@ -30,6 +30,8 @@ obj-$(CONFIG_NF_LOG_IPV6) += nf_log_ipv6.o
# reject
obj-$(CONFIG_NF_REJECT_IPV6) += nf_reject_ipv6.o
+obj-$(CONFIG_NF_TEE_IPV6) += nf_tee_ipv6.o
+
# nf_tables
obj-$(CONFIG_NF_TABLES_IPV6) += nf_tables_ipv6.o
obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV6) += nft_chain_route_ipv6.o
diff --git a/net/ipv6/netfilter/nf_tee_ipv6.c b/net/ipv6/netfilter/nf_tee_ipv6.c
new file mode 100644
index 0000000..f13b61f9
--- /dev/null
+++ b/net/ipv6/netfilter/nf_tee_ipv6.c
@@ -0,0 +1,89 @@
+/*
+ * (C) 2007 by Sebastian Claßen
+ * (C) 2007-2010 by Jan Engelhardt
+ *
+ * Extracted from xt_TEE.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 or later, as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/skbuff.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/netfilter/nf_tee.h>
+#include <net/netfilter/ipv6/nf_tee_ipv6.h>
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+# define WITH_CONNTRACK 1
+# include <net/netfilter/nf_conntrack.h>
+#endif
+
+static DEFINE_PER_CPU(bool, tee_active);
+
+static bool nf_tee_ipv6_route(struct sk_buff *skb, const struct nf_tee *tee)
+{
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+ struct net *net = nf_tee_pick_net(skb);
+ struct dst_entry *dst;
+ struct flowi6 fl6;
+
+ memset(&fl6, 0, sizeof(fl6));
+ if (nf_tee_has_notifier(tee)) {
+ if (tee->oif == -1)
+ return false;
+ fl6.flowi6_oif = tee->oif;
+ }
+ fl6.daddr = tee->gw.in6;
+ fl6.flowlabel = ((iph->flow_lbl[0] & 0xF) << 16) |
+ (iph->flow_lbl[1] << 8) | iph->flow_lbl[2];
+ dst = ip6_route_output(net, NULL, &fl6);
+ if (dst->error) {
+ dst_release(dst);
+ return false;
+ }
+ skb_dst_drop(skb);
+ skb_dst_set(skb, dst);
+ skb->dev = dst->dev;
+ skb->protocol = htons(ETH_P_IPV6);
+
+ return true;
+}
+
+unsigned int nf_tee_ipv6(struct sk_buff *skb, const struct nf_tee *tee,
+ unsigned int hooknum)
+{
+ if (__this_cpu_read(tee_active))
+ return XT_CONTINUE;
+ skb = pskb_copy(skb, GFP_ATOMIC);
+ if (skb == NULL)
+ return XT_CONTINUE;
+
+#ifdef WITH_CONNTRACK
+ nf_conntrack_put(skb->nfct);
+ skb->nfct = &nf_ct_untracked_get()->ct_general;
+ skb->nfctinfo = IP_CT_NEW;
+ nf_conntrack_get(skb->nfct);
+#endif
+ if (hooknum == NF_INET_PRE_ROUTING ||
+ hooknum == NF_INET_LOCAL_IN) {
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+ --iph->hop_limit;
+ }
+ if (nf_tee_ipv6_route(skb, tee)) {
+ __this_cpu_write(tee_active, true);
+ ip6_local_out(skb);
+ __this_cpu_write(tee_active, false);
+ } else {
+ kfree_skb(skb);
+ }
+ return XT_CONTINUE;
+}
+EXPORT_SYMBOL_GPL(nf_tee_ipv6);
+
+MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@xxxxxxxxxx>");
+MODULE_AUTHOR("Jan Engelhardt <jengelh@xxxxxxxxxx>");
+MODULE_DESCRIPTION("nf_tee_ipv6: Reroute IPv6 packet copy");
+MODULE_LICENSE("GPL");
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 6eae69a..afdba34 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -564,6 +564,14 @@ config NFT_COMPAT
endif # NF_TABLES
+config NF_TEE
+ tristate "Netfilter nf_tee module"
+ depends on !NF_CONNTRACK || NF_CONNTRACK
+ help
+ This module is the core nf_tee engine, which allows you
+ to copy and redirect packets to another gateway.
+
+
config NETFILTER_XTABLES
tristate "Netfilter Xtables support (required for ip_tables)"
default m if NETFILTER_ADVANCED=n
@@ -867,6 +875,8 @@ config NETFILTER_XT_TARGET_TEE
depends on NETFILTER_ADVANCED
depends on IPV6 || IPV6=n
depends on !NF_CONNTRACK || NF_CONNTRACK
+ select NF_TEE_IPV4
+ select NF_TEE_IPV6 if IP6_NF_IPTABLES
---help---
This option adds a "TEE" target with which a packet can be cloned and
this clone be rerouted to another nexthop.
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 70d026d..9be0e4b 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -47,6 +47,8 @@ obj-$(CONFIG_NF_CONNTRACK_TFTP) += nf_conntrack_tftp.o
nf_nat-y := nf_nat_core.o nf_nat_proto_unknown.o nf_nat_proto_common.o \
nf_nat_proto_udp.o nf_nat_proto_tcp.o nf_nat_helper.o
+obj-$(CONFIG_NF_TEE) += nf_tee.o
+
# generic transport layer logging
obj-$(CONFIG_NF_LOG_COMMON) += nf_log_common.o
diff --git a/net/netfilter/nf_tee.c b/net/netfilter/nf_tee.c
new file mode 100644
index 0000000..a53f351
--- /dev/null
+++ b/net/netfilter/nf_tee.c
@@ -0,0 +1,98 @@
+/*
+ * (C) 2007 by Sebastian Claßen <sebastian.classen@xxxxxxxxxx>
+ * (C) 2007-2010 by Jan Engelhardt <jengelh@xxxxxxxxxx>
+ *
+ * Extracted from xt_TEE.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 or later, as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ip.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/skbuff.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <net/net_namespace.h>
+#include <net/dst.h>
+#include <net/netfilter/nf_tee.h>
+
+struct net *nf_tee_pick_net(struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_NS
+ const struct dst_entry *dst;
+
+ if (skb->dev != NULL)
+ return dev_net(skb->dev);
+ dst = skb_dst(skb);
+ if (dst != NULL && dst->dev != NULL)
+ return dev_net(dst->dev);
+#endif
+ return &init_net;
+}
+EXPORT_SYMBOL_GPL(nf_tee_pick_net);
+
+static int nf_tee_netdev_event(struct notifier_block *this, unsigned long event,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct nf_tee *tee;
+
+ tee = container_of(this, struct nf_tee, notifier);
+ switch (event) {
+ case NETDEV_REGISTER:
+ if (!strcmp(dev->name, tee->oifname))
+ tee->oif = dev->ifindex;
+ break;
+ case NETDEV_UNREGISTER:
+ if (dev->ifindex == tee->oif)
+ tee->oif = -1;
+ break;
+ case NETDEV_CHANGENAME:
+ if (!strcmp(dev->name, tee->oifname))
+ tee->oif = dev->ifindex;
+ else if (dev->ifindex == tee->oif)
+ tee->oif = -1;
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static const union nf_inet_addr tee_zero_address;
+
+int nf_tee_init(struct nf_tee *tee, union nf_inet_addr gw, const char *oifname)
+{
+ /* 0.0.0.0 and :: not allowed */
+ if (memcmp(&gw, &tee_zero_address, sizeof(tee_zero_address)) == 0)
+ return -EOPNOTSUPP;
+
+ memcpy(&tee->gw, &gw, sizeof(gw));
+ tee->oif = -1;
+
+ if (oifname[0]) {
+ if (oifname[sizeof(tee->oifname) - 1] != '\0')
+ return -EINVAL;
+
+ memcpy(tee->oifname, oifname, sizeof(tee->oifname));
+ tee->notifier.notifier_call = nf_tee_netdev_event;
+ register_netdevice_notifier(&tee->notifier);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nf_tee_init);
+
+void nf_tee_fini(struct nf_tee *tee)
+{
+ if (nf_tee_has_notifier(tee))
+ unregister_netdevice_notifier(&tee->notifier);
+}
+EXPORT_SYMBOL_GPL(nf_tee_fini);
+
+MODULE_AUTHOR("Sebastian Claßen <sebastian.classen@xxxxxxxxxx>");
+MODULE_AUTHOR("Jan Engelhardt <jengelh@xxxxxxxxxx>");
+MODULE_DESCRIPTION("nf_tee: Reroute packet copy");
+MODULE_LICENSE("GPL");
diff --git a/net/netfilter/xt_TEE.c b/net/netfilter/xt_TEE.c
index 189ad13..6bd9a4d 100644
--- a/net/netfilter/xt_TEE.c
+++ b/net/netfilter/xt_TEE.c
@@ -10,256 +10,50 @@
* modify it under the terms of the GNU General Public License
* version 2 or later, as published by the Free Software Foundation.
*/
-#include <linux/ip.h>
#include <linux/module.h>
-#include <linux/percpu.h>
-#include <linux/route.h>
#include <linux/skbuff.h>
-#include <linux/notifier.h>
-#include <net/checksum.h>
-#include <net/icmp.h>
-#include <net/ip.h>
-#include <net/ipv6.h>
-#include <net/ip6_route.h>
-#include <net/route.h>
#include <linux/netfilter/x_tables.h>
+#include <net/netfilter/ipv4/nf_tee_ipv4.h>
+#include <net/netfilter/ipv6/nf_tee_ipv6.h>
#include <linux/netfilter/xt_TEE.h>
-#if IS_ENABLED(CONFIG_NF_CONNTRACK)
-# define WITH_CONNTRACK 1
-# include <net/netfilter/nf_conntrack.h>
-#endif
-
-struct xt_tee_priv {
- struct notifier_block notifier;
- struct xt_tee_tginfo *tginfo;
- int oif;
-};
-
-static const union nf_inet_addr tee_zero_address;
-static DEFINE_PER_CPU(bool, tee_active);
-
-static struct net *pick_net(struct sk_buff *skb)
-{
-#ifdef CONFIG_NET_NS
- const struct dst_entry *dst;
-
- if (skb->dev != NULL)
- return dev_net(skb->dev);
- dst = skb_dst(skb);
- if (dst != NULL && dst->dev != NULL)
- return dev_net(dst->dev);
-#endif
- return &init_net;
-}
-
-static inline bool tee_has_notifier(const struct xt_tee_tginfo *info)
-{
- return info->priv->notifier.notifier_call != NULL;
-}
-
-static bool
-tee_tg_route4(struct sk_buff *skb, const struct xt_tee_tginfo *info)
-{
- const struct iphdr *iph = ip_hdr(skb);
- struct net *net = pick_net(skb);
- struct rtable *rt;
- struct flowi4 fl4;
-
- memset(&fl4, 0, sizeof(fl4));
- if (tee_has_notifier(info)) {
- if (info->priv->oif == -1)
- return false;
- fl4.flowi4_oif = info->priv->oif;
- }
- fl4.daddr = info->gw.ip;
- fl4.flowi4_tos = RT_TOS(iph->tos);
- fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
- fl4.flowi4_flags = FLOWI_FLAG_KNOWN_NH;
- rt = ip_route_output_key(net, &fl4);
- if (IS_ERR(rt))
- return false;
-
- skb_dst_drop(skb);
- skb_dst_set(skb, &rt->dst);
- skb->dev = rt->dst.dev;
- skb->protocol = htons(ETH_P_IP);
- return true;
-}
-
static unsigned int
tee_tg4(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_tee_tginfo *info = par->targinfo;
- struct iphdr *iph;
- if (__this_cpu_read(tee_active))
- return XT_CONTINUE;
- /*
- * Copy the skb, and route the copy. Will later return %XT_CONTINUE for
- * the original skb, which should continue on its way as if nothing has
- * happened. The copy should be independently delivered to the TEE
- * --gateway.
- */
- skb = pskb_copy(skb, GFP_ATOMIC);
- if (skb == NULL)
- return XT_CONTINUE;
-
-#ifdef WITH_CONNTRACK
- /* Avoid counting cloned packets towards the original connection. */
- nf_conntrack_put(skb->nfct);
- skb->nfct = &nf_ct_untracked_get()->ct_general;
- skb->nfctinfo = IP_CT_NEW;
- nf_conntrack_get(skb->nfct);
-#endif
- /*
- * If we are in PREROUTING/INPUT, the checksum must be recalculated
- * since the length could have changed as a result of defragmentation.
- *
- * We also decrease the TTL to mitigate potential TEE loops
- * between two hosts.
- *
- * Set %IP_DF so that the original source is notified of a potentially
- * decreased MTU on the clone route. IPv6 does this too.
- */
- iph = ip_hdr(skb);
- iph->frag_off |= htons(IP_DF);
- if (par->hooknum == NF_INET_PRE_ROUTING ||
- par->hooknum == NF_INET_LOCAL_IN)
- --iph->ttl;
- ip_send_check(iph);
-
- if (tee_tg_route4(skb, info)) {
- __this_cpu_write(tee_active, true);
- ip_local_out(skb);
- __this_cpu_write(tee_active, false);
- } else {
- kfree_skb(skb);
- }
- return XT_CONTINUE;
+ return nf_tee_ipv4(skb, info->priv, par->hooknum);
}
#if IS_ENABLED(CONFIG_IPV6)
-static bool
-tee_tg_route6(struct sk_buff *skb, const struct xt_tee_tginfo *info)
-{
- const struct ipv6hdr *iph = ipv6_hdr(skb);
- struct net *net = pick_net(skb);
- struct dst_entry *dst;
- struct flowi6 fl6;
-
- memset(&fl6, 0, sizeof(fl6));
- if (tee_has_notifier(info)) {
- if (info->priv->oif == -1)
- return false;
- fl6.flowi6_oif = info->priv->oif;
- }
- fl6.daddr = info->gw.in6;
- fl6.flowlabel = ((iph->flow_lbl[0] & 0xF) << 16) |
- (iph->flow_lbl[1] << 8) | iph->flow_lbl[2];
- fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
- dst = ip6_route_output(net, NULL, &fl6);
- if (dst->error) {
- dst_release(dst);
- return false;
- }
- skb_dst_drop(skb);
- skb_dst_set(skb, dst);
- skb->dev = dst->dev;
- skb->protocol = htons(ETH_P_IPV6);
- return true;
-}
-
static unsigned int
tee_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_tee_tginfo *info = par->targinfo;
- if (__this_cpu_read(tee_active))
- return XT_CONTINUE;
- skb = pskb_copy(skb, GFP_ATOMIC);
- if (skb == NULL)
- return XT_CONTINUE;
-
-#ifdef WITH_CONNTRACK
- nf_conntrack_put(skb->nfct);
- skb->nfct = &nf_ct_untracked_get()->ct_general;
- skb->nfctinfo = IP_CT_NEW;
- nf_conntrack_get(skb->nfct);
-#endif
- if (par->hooknum == NF_INET_PRE_ROUTING ||
- par->hooknum == NF_INET_LOCAL_IN) {
- struct ipv6hdr *iph = ipv6_hdr(skb);
- --iph->hop_limit;
- }
- if (tee_tg_route6(skb, info)) {
- __this_cpu_write(tee_active, true);
- ip6_local_out(skb);
- __this_cpu_write(tee_active, false);
- } else {
- kfree_skb(skb);
- }
- return XT_CONTINUE;
+ return nf_tee_ipv6(skb, info->priv, par->hooknum);
}
#endif
-static int tee_netdev_event(struct notifier_block *this, unsigned long event,
- void *ptr)
-{
- struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct xt_tee_priv *priv;
-
- priv = container_of(this, struct xt_tee_priv, notifier);
- switch (event) {
- case NETDEV_REGISTER:
- if (!strcmp(dev->name, priv->tginfo->oif))
- priv->oif = dev->ifindex;
- break;
- case NETDEV_UNREGISTER:
- if (dev->ifindex == priv->oif)
- priv->oif = -1;
- break;
- case NETDEV_CHANGENAME:
- if (!strcmp(dev->name, priv->tginfo->oif))
- priv->oif = dev->ifindex;
- else if (dev->ifindex == priv->oif)
- priv->oif = -1;
- break;
- }
-
- return NOTIFY_DONE;
-}
-
static int tee_tg_check(const struct xt_tgchk_param *par)
{
struct xt_tee_tginfo *info = par->targinfo;
- struct xt_tee_priv *priv;
+ struct nf_tee *tee;
+ int ret;
- /* 0.0.0.0 and :: not allowed */
- if (memcmp(&info->gw, &tee_zero_address,
- sizeof(tee_zero_address)) == 0)
- return -EINVAL;
-
- priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (priv == NULL)
+ tee = kzalloc(sizeof(*tee), GFP_KERNEL);
+ if (tee == NULL)
return -ENOMEM;
- priv->tginfo = info;
- priv->oif = -1;
-
- if (info->oif[0]) {
- if (info->oif[sizeof(info->oif)-1] != '\0')
- goto err1;
+ ret = nf_tee_init(tee, info->gw, info->oif);
+ if (ret < 0)
+ goto err1;
- priv->notifier.notifier_call = tee_netdev_event;
- register_netdevice_notifier(&priv->notifier);
- }
-
- info->priv = priv;
+ info->priv = tee;
return 0;
err1:
- kfree(priv);
+ kfree(tee);
return -EINVAL;
}
@@ -267,9 +61,7 @@ static void tee_tg_destroy(const struct xt_tgdtor_param *par)
{
struct xt_tee_tginfo *info = par->targinfo;
- if (tee_has_notifier(info))
- unregister_netdevice_notifier(&info->priv->notifier);
-
+ nf_tee_fini(info->priv);
kfree(info->priv);
}
--
1.7.10.4
--
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