[PATCH net-next,v4 0/9] netfilter: flowtable bridge and vlan enhancements

[PATCH net-next,v4 0/9] netfilter: flowtable bridge and vlan enhancements

[Pablo Neira Ayuso]

Hi,

The following patchset augments the Netfilter flowtable fastpath [1] to
support for network topologies that combine IP forwarding, bridge and
VLAN devices.

This v4 includes updates for Patches:
- Patch #3 Check for possible device stack overflow in
  dev_fill_forward_path(), per Jakub Kicinski.
- Patch #3 Remove memset for the net_device_path_ctx structure in
  dev_fill_forward_path() and avoid full memset of struct
  net_device_path_stack.
- Patch #5 Check for valid bridge dst pointer after READ_ONCE, per Nikolay
  Aleksandrov.
- Patch #6 remove initialization of the net_device_path_ctx structure,
  already done from patch #3.

A typical scenario that can benefit from this infrastructure is composed
of several VMs connected to bridge ports where the bridge master device
'br0' has an IP address. A DHCP server is also assumed to be running to
provide connectivity to the VMs. The VMs reach the Internet through
'br0' as default gateway, which makes the packet enter the IP forwarding
path. Then, netfilter is used to NAT the packets before they leave
through the wan device.

Something like this:

                       fast path
                .------------------------.
               /                          \
               |           IP forwarding   |
               |          /             \  .
               |       br0               eth0
               .       / \
               -- veth1  veth2
                   .
                   .
                   .
                 eth0
           ab:cd:ef:ab:cd:ef
                  VM

The idea is to accelerate forwarding by building a fast path that takes
packets from the ingress path of the bridge port and place them in the
egress path of the wan device (and vice versa). Hence, skipping the
classic bridge and IP stack paths.

This patchset is composed of:

Patch #1 adds a placeholder for the hash calculation, instead of using
         the dir field.

Patch #2 adds the transmit path type field to the flow tuple. Two transmit
         paths are supported so far: the neighbour and the xfrm transmit
         paths. This patch comes in preparation to add a new direct ethernet
         transmit path (see patch #7).

Patch #3 adds dev_fill_forward_path() and .ndo_fill_forward_path() to
         netdev_ops. This new function describes the list of netdevice hops
         to reach a given destination MAC address in the local network topology,
         e.g.

                           IP forwarding
                          /             \
                       br0              eth0
                       / \
                   veth1 veth2
                    .
                    .
                    .
                   eth0
             ab:cd:ef:ab:cd:ef

          where veth1 and veth2 are bridge ports and eth0 provides Internet
          connectivity. eth0 is the interface in the VM which is connected to
          the veth1 bridge port. Then, for packets going to br0 whose
          destination MAC address is ab:cd:ef:ab:cd:ef, dev_fill_forward_path()
          provides the following path: br0 -> veth1.

Patch #4 adds .ndo_fill_forward_path for VLAN devices, which provides the next
         device hop via vlan->real_dev. This annotates the VLAN id and protocol.
         This is useful to know what VLAN headers are expected from the ingress
         device. This also provides information regarding the VLAN headers
         to be pushed in the egress path.

Patch #5 adds .ndo_fill_forward_path for bridge devices, which allows to make
         lookups to the FDB to locate the next device hop (bridge port) in the
         forwarding path.

Patch #6 updates the flowtable to use the dev_fill_forward_path()
         infrastructure to obtain the ingress device in the fastpath.

Patch #7 updates the flowtable to use dev_fill_forward_path() to obtain the
         egress device in the forwarding path. This also adds the direct
         ethernet transmit path, which pushes the ethernet header to the
         packet and send it through dev_queue_xmit(). This patch adds
         support for the bridge, so bridge ports use this direct xmit path.

Patch #8 adds ingress VLAN support (up to 2 VLAN tags, QinQ). The VLAN
         information is also provided by dev_fill_forward_path(). Store the
         VLAN id and protocol in the flow tuple for hash lookups. The VLAN
         support in the xmit path is achieved by annotating the first vlan
         device found in the xmit path and by calling dev_hard_header()
         (previous patch #7) before dev_queue_xmit().

Patch #9 extends nft_flowtable.sh selftest: This is adding a test to
         cover bridge and vlan support coming in this patchset.

= Performance numbers

My testbed environment consists of three containers:

  192.168.20.2     .20.1     .10.1   10.141.10.2
         veth0       veth0 veth1      veth0
        ns1 <---------> nsr1 <--------> ns2
                            SNAT
     iperf -c                          iperf -s

where nsr1 is used for forwarding. There is a bridge device br0 in nsr1,
veth0 is a port of br0. SNAT is performed on the veth1 device of nsr1.

- ns2 runs iperf -s
- ns1 runs iperf -c 10.141.10.2 -n 100G

My results are:

- Baseline (no flowtable, classic forwarding path + netfilter): ~16 Gbit/s
- Fastpath (with flowtable, this patchset): ~25 Gbit/s

This is an improvement of ~50% compared to baseline.

Please, apply this patchset.

Thank you.

Pablo Neira Ayuso (9):
  netfilter: flowtable: add hash offset field to tuple
  netfilter: flowtable: add xmit path types
  net: resolve forwarding path from virtual netdevice and HW destination address
  net: 8021q: resolve forwarding path for vlan devices
  bridge: resolve forwarding path for bridge devices
  netfilter: flowtable: use dev_fill_forward_path() to obtain ingress device
  netfilter: flowtable: use dev_fill_forward_path() to obtain egress device
  netfilter: flowtable: add vlan support
  selftests: netfilter: flowtable bridge and VLAN support

 include/linux/netdevice.h                     |  35 +++
 include/net/netfilter/nf_flow_table.h         |  43 +++-
 net/8021q/vlan_dev.c                          |  15 ++
 net/bridge/br_device.c                        |  27 +++
 net/core/dev.c                                |  36 ++++
 net/netfilter/nf_flow_table_core.c            |  51 +++--
 net/netfilter/nf_flow_table_ip.c              | 200 ++++++++++++++----
 net/netfilter/nft_flow_offload.c              | 159 +++++++++++++-
 .../selftests/netfilter/nft_flowtable.sh      |  82 +++++++
 9 files changed, 588 insertions(+), 60 deletions(-)

--
2.20.1

[PATCH net-next,v4 1/9] netfilter: flowtable: add hash offset field to tuple

[Pablo Neira Ayuso]

Add a placeholder field to calculate hash tuple offset. Similar to
2c407aca6497 ("netfilter: conntrack: avoid gcc-10 zero-length-bounds
warning").

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: no changes

 include/net/netfilter/nf_flow_table.h | 4 ++++
 net/netfilter/nf_flow_table_core.c    | 6 +++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 16e8b2f8d006..54c4d5c908a5 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -107,6 +107,10 @@ struct flow_offload_tuple {
 
 	u8				l3proto;
 	u8				l4proto;
+
+	/* All members above are keys for lookups, see flow_offload_hash(). */
+	struct { }			__hash;
+
 	u8				dir;
 
 	u16				mtu;
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 513f78db3cb2..55fca71ace26 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -191,14 +191,14 @@ static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
 {
 	const struct flow_offload_tuple *tuple = data;
 
-	return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
+	return jhash(tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 }
 
 static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
 {
 	const struct flow_offload_tuple_rhash *tuplehash = data;
 
-	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
+	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, __hash), seed);
 }
 
 static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
@@ -207,7 +207,7 @@ static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
 	const struct flow_offload_tuple *tuple = arg->key;
 	const struct flow_offload_tuple_rhash *x = ptr;
 
-	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
+	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, __hash)))
 		return 1;
 
 	return 0;
-- 
2.20.1

[PATCH net-next,v4 2/9] netfilter: flowtable: add xmit path types

[Pablo Neira Ayuso]

Add the xmit_type field that defines the two supported xmit paths in the
flowtable data plane, which are the neighbour and the xfrm xmit paths.
This patch prepares for new flowtable xmit path types to come.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: no changes

 include/net/netfilter/nf_flow_table.h | 11 +++++++--
 net/netfilter/nf_flow_table_core.c    |  1 +
 net/netfilter/nf_flow_table_ip.c      | 32 ++++++++++++++++++---------
 net/netfilter/nft_flow_offload.c      | 20 +++++++++++++++--
 4 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 54c4d5c908a5..7d477be06913 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -89,6 +89,11 @@ enum flow_offload_tuple_dir {
 	FLOW_OFFLOAD_DIR_MAX = IP_CT_DIR_MAX
 };
 
+enum flow_offload_xmit_type {
+	FLOW_OFFLOAD_XMIT_NEIGH		= 0,
+	FLOW_OFFLOAD_XMIT_XFRM,
+};
+
 struct flow_offload_tuple {
 	union {
 		struct in_addr		src_v4;
@@ -111,7 +116,8 @@ struct flow_offload_tuple {
 	/* All members above are keys for lookups, see flow_offload_hash(). */
 	struct { }			__hash;
 
-	u8				dir;
+	u8				dir:6,
+					xmit_type:2;
 
 	u16				mtu;
 
@@ -158,7 +164,8 @@ static inline __s32 nf_flow_timeout_delta(unsigned int timeout)
 
 struct nf_flow_route {
 	struct {
-		struct dst_entry	*dst;
+		struct dst_entry		*dst;
+		enum flow_offload_xmit_type	xmit_type;
 	} tuple[FLOW_OFFLOAD_DIR_MAX];
 };
 
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 55fca71ace26..57dd8e40e474 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -95,6 +95,7 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 	}
 
 	flow_tuple->iifidx = other_dst->dev->ifindex;
+	flow_tuple->xmit_type = route->tuple[dir].xmit_type;
 	flow_tuple->dst_cache = dst;
 
 	return 0;
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index a698dbe28ef5..03314cc06e04 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -220,10 +220,20 @@ static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
 	return true;
 }
 
-static int nf_flow_offload_dst_check(struct dst_entry *dst)
+static inline struct dst_entry *
+nft_flow_dst(struct flow_offload_tuple_rhash *tuplehash)
 {
-	if (unlikely(dst_xfrm(dst)))
+	return tuplehash->tuple.dst_cache;
+}
+
+static int nf_flow_offload_dst_check(struct flow_offload_tuple_rhash *tuplehash)
+{
+	struct dst_entry *dst;
+
+	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
+		dst = nft_flow_dst(tuplehash);
 		return dst_check(dst, 0) ? 0 : -1;
+	}
 
 	return 0;
 }
@@ -265,8 +275,6 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 
 	dir = tuplehash->tuple.dir;
 	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
-	rt = (struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
-	outdev = rt->dst.dev;
 
 	if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
 		return NF_ACCEPT;
@@ -280,7 +288,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 
 	flow_offload_refresh(flow_table, flow);
 
-	if (nf_flow_offload_dst_check(&rt->dst)) {
+	if (nf_flow_offload_dst_check(tuplehash)) {
 		flow_offload_teardown(flow);
 		return NF_ACCEPT;
 	}
@@ -295,13 +303,16 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
 
-	if (unlikely(dst_xfrm(&rt->dst))) {
+	rt = (struct rtable *)tuplehash->tuple.dst_cache;
+
+	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
 		memset(skb->cb, 0, sizeof(struct inet_skb_parm));
 		IPCB(skb)->iif = skb->dev->ifindex;
 		IPCB(skb)->flags = IPSKB_FORWARDED;
 		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
 	}
 
+	outdev = rt->dst.dev;
 	skb->dev = outdev;
 	nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
 	skb_dst_set_noref(skb, &rt->dst);
@@ -506,8 +517,6 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 
 	dir = tuplehash->tuple.dir;
 	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
-	rt = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache;
-	outdev = rt->dst.dev;
 
 	if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
 		return NF_ACCEPT;
@@ -518,7 +527,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 
 	flow_offload_refresh(flow_table, flow);
 
-	if (nf_flow_offload_dst_check(&rt->dst)) {
+	if (nf_flow_offload_dst_check(tuplehash)) {
 		flow_offload_teardown(flow);
 		return NF_ACCEPT;
 	}
@@ -536,13 +545,16 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
 
-	if (unlikely(dst_xfrm(&rt->dst))) {
+	rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
+
+	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH)) {
 		memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 		IP6CB(skb)->iif = skb->dev->ifindex;
 		IP6CB(skb)->flags = IP6SKB_FORWARDED;
 		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
 	}
 
+	outdev = rt->dst.dev;
 	skb->dev = outdev;
 	nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
 	skb_dst_set_noref(skb, &rt->dst);
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 3a6c84fb2c90..1da2bb24f6c0 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -19,6 +19,22 @@ struct nft_flow_offload {
 	struct nft_flowtable	*flowtable;
 };
 
+static enum flow_offload_xmit_type nft_xmit_type(struct dst_entry *dst)
+{
+	if (dst_xfrm(dst))
+		return FLOW_OFFLOAD_XMIT_XFRM;
+
+	return FLOW_OFFLOAD_XMIT_NEIGH;
+}
+
+static void nft_default_forward_path(struct nf_flow_route *route,
+				     struct dst_entry *dst_cache,
+				     enum ip_conntrack_dir dir)
+{
+	route->tuple[dir].dst		= dst_cache;
+	route->tuple[dir].xmit_type	= nft_xmit_type(dst_cache);
+}
+
 static int nft_flow_route(const struct nft_pktinfo *pkt,
 			  const struct nf_conn *ct,
 			  struct nf_flow_route *route,
@@ -44,8 +60,8 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
 	if (!other_dst)
 		return -ENOENT;
 
-	route->tuple[dir].dst		= this_dst;
-	route->tuple[!dir].dst		= other_dst;
+	nft_default_forward_path(route, this_dst, dir);
+	nft_default_forward_path(route, other_dst, !dir);
 
 	return 0;
 }
-- 
2.20.1

[PATCH net-next,v4 3/9] net: resolve forwarding path from virtual netdevice and HW destination address

[Pablo Neira Ayuso]

This patch adds dev_fill_forward_path() which resolves the path to reach
the real netdevice from the IP forwarding side. This function takes as
input the netdevice and the destination hardware address and it walks
down the devices calling .ndo_fill_forward_path() for each device until
the real device is found.

For instance, assuming the following topology:

               IP forwarding
              /             \
           br0              eth0
           / \
       eth1  eth2
        .
        .
        .
       ethX
 ab:cd:ef:ab:cd:ef

where eth1 and eth2 are bridge ports and eth0 provides WAN connectivity.
ethX is the interface in another box which is connected to the eth1
bridge port.

For packets going through IP forwarding to br0 whose destination MAC
address is ab:cd:ef:ab:cd:ef, dev_fill_forward_path() provides the
following path:

	br0 -> eth1

.ndo_fill_forward_path for br0 looks up at the FDB for the bridge port
from the destination MAC address to get the bridge port eth1.

This information allows to create a fast path that bypasses the classic
bridge and IP forwarding paths, so packets go directly from the bridge
port eth1 to eth0 (wan interface) and vice versa.

             fast path
      .------------------------.
     /                          \
    |           IP forwarding   |
    |          /             \  \/
    |       br0               eth0
    .       / \
     -> eth1  eth2
        .
        .
        .
       ethX
 ab:cd:ef:ab:cd:ef

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: - Check for possible device stack overflow in dev_fill_forward_path(),
      per Jakub Kicinski.
    - Remove memset for the net_device_path_ctx structure in
      dev_fill_forward_path() and avoid full memset of struct
      net_device_path_stack.

 include/linux/netdevice.h | 27 +++++++++++++++++++++++++++
 net/core/dev.c            | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 03433a4c929e..ef4fc0eefee0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -833,6 +833,27 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
 				       struct sk_buff *skb,
 				       struct net_device *sb_dev);
 
+enum net_device_path_type {
+	DEV_PATH_ETHERNET = 0,
+};
+
+struct net_device_path {
+	enum net_device_path_type	type;
+	const struct net_device		*dev;
+};
+
+#define NET_DEVICE_PATH_STACK_MAX	5
+
+struct net_device_path_stack {
+	int			num_paths;
+	struct net_device_path	path[NET_DEVICE_PATH_STACK_MAX];
+};
+
+struct net_device_path_ctx {
+	const struct net_device *dev;
+	const u8		*daddr;
+};
+
 enum tc_setup_type {
 	TC_SETUP_QDISC_MQPRIO,
 	TC_SETUP_CLSU32,
@@ -1279,6 +1300,8 @@ struct netdev_net_notifier {
  * struct net_device *(*ndo_get_peer_dev)(struct net_device *dev);
  *	If a device is paired with a peer device, return the peer instance.
  *	The caller must be under RCU read context.
+ * int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, struct net_device_path *path);
+ *	Get the forwarding path to reach the real device from the HW destination address
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1487,6 +1510,8 @@ struct net_device_ops {
 	int			(*ndo_tunnel_ctl)(struct net_device *dev,
 						  struct ip_tunnel_parm *p, int cmd);
 	struct net_device *	(*ndo_get_peer_dev)(struct net_device *dev);
+	int			(*ndo_fill_forward_path)(struct net_device_path_ctx *ctx,
+							 struct net_device_path *path);
 };
 
 /**
@@ -2824,6 +2849,8 @@ void dev_remove_offload(struct packet_offload *po);
 
 int dev_get_iflink(const struct net_device *dev);
 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb);
+int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
+			  struct net_device_path_stack *stack);
 struct net_device *__dev_get_by_flags(struct net *net, unsigned short flags,
 				      unsigned short mask);
 struct net_device *dev_get_by_name(struct net *net, const char *name);
diff --git a/net/core/dev.c b/net/core/dev.c
index 4bfdcd6b20e8..d65bab678485 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -846,6 +846,42 @@ int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 }
 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
 
+int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
+			  struct net_device_path_stack *stack)
+{
+	const struct net_device *last_dev;
+	struct net_device_path_ctx ctx = {
+		.dev	= dev,
+		.daddr	= daddr,
+	};
+	struct net_device_path *path;
+	int ret = 0, k;
+
+	stack->num_paths = 0;
+	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
+		last_dev = ctx.dev;
+		k = stack->num_paths++;
+		if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
+			return -1;
+
+		path = &stack->path[k];
+		memset(path, 0, sizeof(struct net_device_path));
+
+		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
+		if (ret < 0)
+			return -1;
+
+		if (WARN_ON_ONCE(last_dev == ctx.dev))
+			return -1;
+	}
+	path = &stack->path[stack->num_paths++];
+	path->type = DEV_PATH_ETHERNET;
+	path->dev = ctx.dev;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_fill_forward_path);
+
 /**
  *	__dev_get_by_name	- find a device by its name
  *	@net: the applicable net namespace
-- 
2.20.1

[PATCH net-next,v4 4/9] net: 8021q: resolve forwarding path for vlan devices

[Pablo Neira Ayuso]

Add .ndo_fill_forward_path for vlan devices.

For instance, assuming the following topology:

                   IP forwarding
                  /             \
            eth0.100             eth0
            |
            eth0
            .
            .
            .
           ethX
     ab:cd:ef:ab:cd:ef

For packets going through IP forwarding to eth0.100 whose destination
MAC address is ab:cd:ef:ab:cd:ef, dev_fill_forward_path() provides the
following path:

        eth0.100 -> eth0

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: no changes

 include/linux/netdevice.h |  7 +++++++
 net/8021q/vlan_dev.c      | 15 +++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ef4fc0eefee0..e9690e1a6559 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -835,11 +835,18 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
 
 enum net_device_path_type {
 	DEV_PATH_ETHERNET = 0,
+	DEV_PATH_VLAN,
 };
 
 struct net_device_path {
 	enum net_device_path_type	type;
 	const struct net_device		*dev;
+	union {
+		struct {
+			u16		id;
+			__be16		proto;
+		} vlan;
+	};
 };
 
 #define NET_DEVICE_PATH_STACK_MAX	5
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index ec8408d1638f..f06a507557f9 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -767,6 +767,20 @@ static int vlan_dev_get_iflink(const struct net_device *dev)
 	return real_dev->ifindex;
 }
 
+static int vlan_dev_fill_forward_path(struct net_device_path_ctx *ctx,
+				      struct net_device_path *path)
+{
+	struct vlan_dev_priv *vlan = vlan_dev_priv(ctx->dev);
+
+	path->type = DEV_PATH_VLAN;
+	path->vlan.id = vlan->vlan_id;
+	path->vlan.proto = vlan->vlan_proto;
+	path->dev = ctx->dev;
+	ctx->dev = vlan->real_dev;
+
+	return 0;
+}
+
 static const struct ethtool_ops vlan_ethtool_ops = {
 	.get_link_ksettings	= vlan_ethtool_get_link_ksettings,
 	.get_drvinfo	        = vlan_ethtool_get_drvinfo,
@@ -805,6 +819,7 @@ static const struct net_device_ops vlan_netdev_ops = {
 #endif
 	.ndo_fix_features	= vlan_dev_fix_features,
 	.ndo_get_iflink		= vlan_dev_get_iflink,
+	.ndo_fill_forward_path	= vlan_dev_fill_forward_path,
 };
 
 static void vlan_dev_free(struct net_device *dev)
-- 
2.20.1

[PATCH net-next,v4 5/9] bridge: resolve forwarding path for bridge devices

[Pablo Neira Ayuso]

Add .ndo_fill_forward_path for bridge devices.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: - Check for valid bridge dst pointer after READ_ONCE, per Nikolay
      Aleksandrov.

 include/linux/netdevice.h |  1 +
 net/bridge/br_device.c    | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e9690e1a6559..281551c70536 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -836,6 +836,7 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
 enum net_device_path_type {
 	DEV_PATH_ETHERNET = 0,
 	DEV_PATH_VLAN,
+	DEV_PATH_BRIDGE,
 };
 
 struct net_device_path {
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 387403931a63..ce03d82e384a 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -391,6 +391,32 @@ static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 	return br_del_if(br, slave_dev);
 }
 
+static int br_fill_forward_path(struct net_device_path_ctx *ctx,
+				struct net_device_path *path)
+{
+	struct net_bridge_fdb_entry *f;
+	struct net_bridge_port *dst;
+	struct net_bridge *br;
+
+	if (netif_is_bridge_port(ctx->dev))
+		return -1;
+
+	br = netdev_priv(ctx->dev);
+	f = br_fdb_find_rcu(br, ctx->daddr, 0);
+	if (!f || !f->dst)
+		return -1;
+
+	dst = READ_ONCE(f->dst);
+	if (!dst)
+		return -1;
+
+	path->type = DEV_PATH_BRIDGE;
+	path->dev = dst->br->dev;
+	ctx->dev = dst->dev;
+
+	return 0;
+}
+
 static const struct ethtool_ops br_ethtool_ops = {
 	.get_drvinfo		 = br_getinfo,
 	.get_link		 = ethtool_op_get_link,
@@ -425,6 +451,7 @@ static const struct net_device_ops br_netdev_ops = {
 	.ndo_bridge_setlink	 = br_setlink,
 	.ndo_bridge_dellink	 = br_dellink,
 	.ndo_features_check	 = passthru_features_check,
+	.ndo_fill_forward_path	 = br_fill_forward_path,
 };
 
 static struct device_type br_type = {
-- 
2.20.1

[PATCH net-next,v4 6/9] netfilter: flowtable: use dev_fill_forward_path() to obtain ingress device

[Pablo Neira Ayuso]

Obtain the ingress device in the tuple from the route in the reply
direction. Use dev_fill_forward_path() instead to get the real ingress
device for this flow.

Fall back to use the ingress device that the IP forwarding route
provides if:

- dev_fill_forward_path() finds no real ingress device.
- the ingress device that is obtained is not part of the flowtable
  devices.
- this route has a xfrm policy.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: skip initialization of net_device_path_stack in nft_dev_forward_path(),
    already done in patch #3.

 include/net/netfilter/nf_flow_table.h |   3 +
 net/netfilter/nf_flow_table_core.c    |   3 +-
 net/netfilter/nft_flow_offload.c      | 101 +++++++++++++++++++++++++-
 3 files changed, 102 insertions(+), 5 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 7d477be06913..963f99fb1c06 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -165,6 +165,9 @@ static inline __s32 nf_flow_timeout_delta(unsigned int timeout)
 struct nf_flow_route {
 	struct {
 		struct dst_entry		*dst;
+		struct {
+			u32			ifindex;
+		} in;
 		enum flow_offload_xmit_type	xmit_type;
 	} tuple[FLOW_OFFLOAD_DIR_MAX];
 };
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 57dd8e40e474..27b4315d7b96 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -79,7 +79,6 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 				   enum flow_offload_tuple_dir dir)
 {
 	struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
-	struct dst_entry *other_dst = route->tuple[!dir].dst;
 	struct dst_entry *dst = route->tuple[dir].dst;
 
 	if (!dst_hold_safe(route->tuple[dir].dst))
@@ -94,7 +93,7 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 		break;
 	}
 
-	flow_tuple->iifidx = other_dst->dev->ifindex;
+	flow_tuple->iifidx = route->tuple[dir].in.ifindex;
 	flow_tuple->xmit_type = route->tuple[dir].xmit_type;
 	flow_tuple->dst_cache = dst;
 
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 1da2bb24f6c0..15f5a3b38253 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -31,14 +31,103 @@ static void nft_default_forward_path(struct nf_flow_route *route,
 				     struct dst_entry *dst_cache,
 				     enum ip_conntrack_dir dir)
 {
+	route->tuple[!dir].in.ifindex	= dst_cache->dev->ifindex;
 	route->tuple[dir].dst		= dst_cache;
 	route->tuple[dir].xmit_type	= nft_xmit_type(dst_cache);
 }
 
+static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
+				     const struct dst_entry *dst_cache,
+				     const struct nf_conn *ct,
+				     enum ip_conntrack_dir dir,
+				     struct net_device_path_stack *stack)
+{
+	const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
+	struct net_device *dev = dst_cache->dev;
+	unsigned char ha[ETH_ALEN];
+	struct neighbour *n;
+	u8 nud_state;
+
+	n = dst_neigh_lookup(dst_cache, daddr);
+	if (!n)
+		return -1;
+
+	read_lock_bh(&n->lock);
+	nud_state = n->nud_state;
+	ether_addr_copy(ha, n->ha);
+	read_unlock_bh(&n->lock);
+	neigh_release(n);
+
+	if (!(nud_state & NUD_VALID))
+		return -1;
+
+	return dev_fill_forward_path(dev, ha, stack);
+}
+
+struct nft_forward_info {
+	const struct net_device *indev;
+};
+
+static void nft_dev_path_info(const struct net_device_path_stack *stack,
+			      struct nft_forward_info *info)
+{
+	const struct net_device_path *path;
+	int i;
+
+	for (i = stack->num_paths - 1; i >= 0; i--) {
+		path = &stack->path[i];
+		switch (path->type) {
+		case DEV_PATH_ETHERNET:
+			info->indev = path->dev;
+			break;
+		case DEV_PATH_VLAN:
+			break;
+		case DEV_PATH_BRIDGE:
+			break;
+		}
+	}
+}
+
+static bool nft_flowtable_find_dev(const struct net_device *dev,
+				   struct nft_flowtable *ft)
+{
+	struct nft_hook *hook;
+	bool found = false;
+
+	list_for_each_entry_rcu(hook, &ft->hook_list, list) {
+		if (hook->ops.dev != dev)
+			continue;
+
+		found = true;
+		break;
+	}
+
+	return found;
+}
+
+static void nft_dev_forward_path(struct nf_flow_route *route,
+				 const struct nf_conn *ct,
+				 enum ip_conntrack_dir dir,
+				 struct nft_flowtable *ft)
+{
+	const struct dst_entry *dst = route->tuple[dir].dst;
+	struct net_device_path_stack stack;
+	struct nft_forward_info info = {};
+
+	if (nft_dev_fill_forward_path(route, dst, ct, dir, &stack) >= 0)
+		nft_dev_path_info(&stack, &info);
+
+	if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
+		return;
+
+	route->tuple[!dir].in.ifindex = info.indev->ifindex;
+}
+
 static int nft_flow_route(const struct nft_pktinfo *pkt,
 			  const struct nf_conn *ct,
 			  struct nf_flow_route *route,
-			  enum ip_conntrack_dir dir)
+			  enum ip_conntrack_dir dir,
+			  struct nft_flowtable *ft)
 {
 	struct dst_entry *this_dst = skb_dst(pkt->skb);
 	struct dst_entry *other_dst = NULL;
@@ -63,6 +152,12 @@ static int nft_flow_route(const struct nft_pktinfo *pkt,
 	nft_default_forward_path(route, this_dst, dir);
 	nft_default_forward_path(route, other_dst, !dir);
 
+	if (route->tuple[dir].xmit_type	== FLOW_OFFLOAD_XMIT_NEIGH &&
+	    route->tuple[!dir].xmit_type == FLOW_OFFLOAD_XMIT_NEIGH) {
+		nft_dev_forward_path(route, ct, dir, ft);
+		nft_dev_forward_path(route, ct, !dir, ft);
+	}
+
 	return 0;
 }
 
@@ -90,8 +185,8 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
 	struct nft_flow_offload *priv = nft_expr_priv(expr);
 	struct nf_flowtable *flowtable = &priv->flowtable->data;
 	struct tcphdr _tcph, *tcph = NULL;
+	struct nf_flow_route route = {};
 	enum ip_conntrack_info ctinfo;
-	struct nf_flow_route route;
 	struct flow_offload *flow;
 	enum ip_conntrack_dir dir;
 	struct nf_conn *ct;
@@ -128,7 +223,7 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
 		goto out;
 
 	dir = CTINFO2DIR(ctinfo);
-	if (nft_flow_route(pkt, ct, &route, dir) < 0)
+	if (nft_flow_route(pkt, ct, &route, dir, priv->flowtable) < 0)
 		goto err_flow_route;
 
 	flow = flow_offload_alloc(ct);
-- 
2.20.1

[PATCH net-next,v4 7/9] netfilter: flowtable: use dev_fill_forward_path() to obtain egress device

[Pablo Neira Ayuso]

The egress device in the tuple is obtained from route. Use
dev_fill_forward_path() instead to provide the real egress device for
this flow whenever this is available.

The new FLOW_OFFLOAD_XMIT_DIRECT type uses dev_queue_xmit() to transmit
ethernet frames. Cache the source and destination hardware address to
use dev_queue_xmit() to transfer packets.

The FLOW_OFFLOAD_XMIT_DIRECT replaces FLOW_OFFLOAD_XMIT_NEIGH if
dev_fill_forward_path() finds a direct transmit path.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: no changes.

 include/net/netfilter/nf_flow_table.h | 16 +++++-
 net/netfilter/nf_flow_table_core.c    | 35 ++++++++++---
 net/netfilter/nf_flow_table_ip.c      | 72 +++++++++++++++++++++------
 net/netfilter/nft_flow_offload.c      | 25 ++++++++--
 4 files changed, 118 insertions(+), 30 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 963f99fb1c06..83110e4705c0 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -92,6 +92,7 @@ enum flow_offload_tuple_dir {
 enum flow_offload_xmit_type {
 	FLOW_OFFLOAD_XMIT_NEIGH		= 0,
 	FLOW_OFFLOAD_XMIT_XFRM,
+	FLOW_OFFLOAD_XMIT_DIRECT,
 };
 
 struct flow_offload_tuple {
@@ -120,8 +121,14 @@ struct flow_offload_tuple {
 					xmit_type:2;
 
 	u16				mtu;
-
-	struct dst_entry		*dst_cache;
+	union {
+		struct dst_entry	*dst_cache;
+		struct {
+			u32		ifidx;
+			u8		h_source[ETH_ALEN];
+			u8		h_dest[ETH_ALEN];
+		} out;
+	};
 };
 
 struct flow_offload_tuple_rhash {
@@ -168,6 +175,11 @@ struct nf_flow_route {
 		struct {
 			u32			ifindex;
 		} in;
+		struct {
+			u32			ifindex;
+			u8			h_source[ETH_ALEN];
+			u8			h_dest[ETH_ALEN];
+		} out;
 		enum flow_offload_xmit_type	xmit_type;
 	} tuple[FLOW_OFFLOAD_DIR_MAX];
 };
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 27b4315d7b96..751bc1c27c16 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -81,9 +81,6 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 	struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
 	struct dst_entry *dst = route->tuple[dir].dst;
 
-	if (!dst_hold_safe(route->tuple[dir].dst))
-		return -1;
-
 	switch (flow_tuple->l3proto) {
 	case NFPROTO_IPV4:
 		flow_tuple->mtu = ip_dst_mtu_maybe_forward(dst, true);
@@ -94,12 +91,36 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 	}
 
 	flow_tuple->iifidx = route->tuple[dir].in.ifindex;
+
+	switch (route->tuple[dir].xmit_type) {
+	case FLOW_OFFLOAD_XMIT_DIRECT:
+		memcpy(flow_tuple->out.h_dest, route->tuple[dir].out.h_dest,
+		       ETH_ALEN);
+		memcpy(flow_tuple->out.h_source, route->tuple[dir].out.h_source,
+		       ETH_ALEN);
+		flow_tuple->out.ifidx = route->tuple[dir].out.ifindex;
+		break;
+	case FLOW_OFFLOAD_XMIT_XFRM:
+	case FLOW_OFFLOAD_XMIT_NEIGH:
+		if (!dst_hold_safe(route->tuple[dir].dst))
+			return -1;
+
+		flow_tuple->dst_cache = dst;
+		break;
+	}
 	flow_tuple->xmit_type = route->tuple[dir].xmit_type;
-	flow_tuple->dst_cache = dst;
 
 	return 0;
 }
 
+static void nft_flow_dst_release(struct flow_offload *flow,
+				 enum flow_offload_tuple_dir dir)
+{
+	if (flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH ||
+	    flow->tuplehash[dir].tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
+		dst_release(flow->tuplehash[dir].tuple.dst_cache);
+}
+
 int flow_offload_route_init(struct flow_offload *flow,
 			    const struct nf_flow_route *route)
 {
@@ -118,7 +139,7 @@ int flow_offload_route_init(struct flow_offload *flow,
 	return 0;
 
 err_route_reply:
-	dst_release(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst);
+	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
 
 	return err;
 }
@@ -169,8 +190,8 @@ static void flow_offload_fixup_ct(struct nf_conn *ct)
 
 static void flow_offload_route_release(struct flow_offload *flow)
 {
-	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
-	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
+	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_ORIGINAL);
+	nft_flow_dst_release(flow, FLOW_OFFLOAD_DIR_REPLY);
 }
 
 void flow_offload_free(struct flow_offload *flow)
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 03314cc06e04..d10ba09a41b5 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -248,6 +248,24 @@ static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb,
 	return NF_STOLEN;
 }
 
+static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb,
+				       const struct flow_offload_tuple_rhash *tuplehash,
+				       unsigned short type)
+{
+	struct net_device *outdev;
+
+	outdev = dev_get_by_index_rcu(net, tuplehash->tuple.out.ifidx);
+	if (!outdev)
+		return NF_DROP;
+
+	skb->dev = outdev;
+	dev_hard_header(skb, skb->dev, type, tuplehash->tuple.out.h_dest,
+			tuplehash->tuple.out.h_source, skb->len);
+	dev_queue_xmit(skb);
+
+	return NF_STOLEN;
+}
+
 unsigned int
 nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 			const struct nf_hook_state *state)
@@ -262,6 +280,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	unsigned int thoff;
 	struct iphdr *iph;
 	__be32 nexthop;
+	int ret;
 
 	if (skb->protocol != htons(ETH_P_IP))
 		return NF_ACCEPT;
@@ -303,22 +322,32 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
 
-	rt = (struct rtable *)tuplehash->tuple.dst_cache;
-
 	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
+		rt = (struct rtable *)tuplehash->tuple.dst_cache;
 		memset(skb->cb, 0, sizeof(struct inet_skb_parm));
 		IPCB(skb)->iif = skb->dev->ifindex;
 		IPCB(skb)->flags = IPSKB_FORWARDED;
 		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
 	}
 
-	outdev = rt->dst.dev;
-	skb->dev = outdev;
-	nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
-	skb_dst_set_noref(skb, &rt->dst);
-	neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
+	switch (tuplehash->tuple.xmit_type) {
+	case FLOW_OFFLOAD_XMIT_NEIGH:
+		rt = (struct rtable *)tuplehash->tuple.dst_cache;
+		outdev = rt->dst.dev;
+		skb->dev = outdev;
+		nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
+		skb_dst_set_noref(skb, &rt->dst);
+		neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
+		ret = NF_STOLEN;
+		break;
+	case FLOW_OFFLOAD_XMIT_DIRECT:
+		ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IP);
+		if (ret == NF_DROP)
+			flow_offload_teardown(flow);
+		break;
+	}
 
-	return NF_STOLEN;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);
 
@@ -504,6 +533,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	struct net_device *outdev;
 	struct ipv6hdr *ip6h;
 	struct rt6_info *rt;
+	int ret;
 
 	if (skb->protocol != htons(ETH_P_IPV6))
 		return NF_ACCEPT;
@@ -545,21 +575,31 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
 
-	rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
-
 	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH)) {
+		rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
 		memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 		IP6CB(skb)->iif = skb->dev->ifindex;
 		IP6CB(skb)->flags = IP6SKB_FORWARDED;
 		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
 	}
 
-	outdev = rt->dst.dev;
-	skb->dev = outdev;
-	nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
-	skb_dst_set_noref(skb, &rt->dst);
-	neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);
+	switch (tuplehash->tuple.xmit_type) {
+	case FLOW_OFFLOAD_XMIT_NEIGH:
+		rt = (struct rt6_info *)tuplehash->tuple.dst_cache;
+		outdev = rt->dst.dev;
+		skb->dev = outdev;
+		nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
+		skb_dst_set_noref(skb, &rt->dst);
+		neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);
+		ret = NF_STOLEN;
+		break;
+	case FLOW_OFFLOAD_XMIT_DIRECT:
+		ret = nf_flow_queue_xmit(state->net, skb, tuplehash, ETH_P_IPV6);
+		if (ret == NF_DROP)
+			flow_offload_teardown(flow);
+		break;
+	}
 
-	return NF_STOLEN;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook);
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 15f5a3b38253..68d03569c293 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -39,12 +39,11 @@ static void nft_default_forward_path(struct nf_flow_route *route,
 static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
 				     const struct dst_entry *dst_cache,
 				     const struct nf_conn *ct,
-				     enum ip_conntrack_dir dir,
+				     enum ip_conntrack_dir dir, u8 *ha,
 				     struct net_device_path_stack *stack)
 {
 	const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
 	struct net_device *dev = dst_cache->dev;
-	unsigned char ha[ETH_ALEN];
 	struct neighbour *n;
 	u8 nud_state;
 
@@ -66,10 +65,14 @@ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
 
 struct nft_forward_info {
 	const struct net_device *indev;
+	u8 h_source[ETH_ALEN];
+	u8 h_dest[ETH_ALEN];
+	enum flow_offload_xmit_type xmit_type;
 };
 
 static void nft_dev_path_info(const struct net_device_path_stack *stack,
-			      struct nft_forward_info *info)
+			      struct nft_forward_info *info,
+			      unsigned char *ha)
 {
 	const struct net_device_path *path;
 	int i;
@@ -79,10 +82,14 @@ static void nft_dev_path_info(const struct net_device_path_stack *stack,
 		switch (path->type) {
 		case DEV_PATH_ETHERNET:
 			info->indev = path->dev;
+			memcpy(info->h_dest, path->dev->dev_addr, ETH_ALEN);
+			memcpy(info->h_source, ha, ETH_ALEN);
 			break;
 		case DEV_PATH_VLAN:
 			break;
 		case DEV_PATH_BRIDGE:
+			memcpy(info->h_dest, path->dev->dev_addr, ETH_ALEN);
+			info->xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
 			break;
 		}
 	}
@@ -113,14 +120,22 @@ static void nft_dev_forward_path(struct nf_flow_route *route,
 	const struct dst_entry *dst = route->tuple[dir].dst;
 	struct net_device_path_stack stack;
 	struct nft_forward_info info = {};
+	unsigned char ha[ETH_ALEN];
 
-	if (nft_dev_fill_forward_path(route, dst, ct, dir, &stack) >= 0)
-		nft_dev_path_info(&stack, &info);
+	if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
+		nft_dev_path_info(&stack, &info, ha);
 
 	if (!info.indev || !nft_flowtable_find_dev(info.indev, ft))
 		return;
 
 	route->tuple[!dir].in.ifindex = info.indev->ifindex;
+
+	if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
+		memcpy(route->tuple[dir].out.h_dest, info.h_source, ETH_ALEN);
+		memcpy(route->tuple[dir].out.h_source, info.h_dest, ETH_ALEN);
+		route->tuple[dir].out.ifindex = info.indev->ifindex;
+		route->tuple[dir].xmit_type = info.xmit_type;
+	}
 }
 
 static int nft_flow_route(const struct nft_pktinfo *pkt,
-- 
2.20.1

[PATCH net-next,v4 8/9] netfilter: flowtable: add vlan support

[Pablo Neira Ayuso]

Add the vlan id and protocol to the flow tuple to uniquely identify
flows from the receive path. For the transmit path, dev_hard_header() on
the vlan device push the headers. This patch includes support for two
VLAN headers (QinQ) from the ingress path.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: no changes.

 include/net/netfilter/nf_flow_table.h |  15 +++-
 net/netfilter/nf_flow_table_core.c    |   6 ++
 net/netfilter/nf_flow_table_ip.c      | 108 +++++++++++++++++++++-----
 net/netfilter/nft_flow_offload.c      |  25 +++++-
 4 files changed, 131 insertions(+), 23 deletions(-)

diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index 83110e4705c0..e65bbbd982cb 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -95,6 +95,8 @@ enum flow_offload_xmit_type {
 	FLOW_OFFLOAD_XMIT_DIRECT,
 };
 
+#define NF_FLOW_TABLE_VLAN_MAX	2
+
 struct flow_offload_tuple {
 	union {
 		struct in_addr		src_v4;
@@ -113,13 +115,17 @@ struct flow_offload_tuple {
 
 	u8				l3proto;
 	u8				l4proto;
+	struct {
+		u16			id;
+		__be16			proto;
+	} in_vlan[NF_FLOW_TABLE_VLAN_MAX];
 
 	/* All members above are keys for lookups, see flow_offload_hash(). */
 	struct { }			__hash;
 
-	u8				dir:6,
-					xmit_type:2;
-
+	u8				dir:4,
+					xmit_type:2,
+					in_vlan_num:2;
 	u16				mtu;
 	union {
 		struct dst_entry	*dst_cache;
@@ -174,6 +180,9 @@ struct nf_flow_route {
 		struct dst_entry		*dst;
 		struct {
 			u32			ifindex;
+			u16			vid[NF_FLOW_TABLE_VLAN_MAX];
+			__be16			vproto[NF_FLOW_TABLE_VLAN_MAX];
+			u8			num_vlans;
 		} in;
 		struct {
 			u32			ifindex;
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 751bc1c27c16..c4322aeb3557 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -80,6 +80,7 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 {
 	struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
 	struct dst_entry *dst = route->tuple[dir].dst;
+	int i;
 
 	switch (flow_tuple->l3proto) {
 	case NFPROTO_IPV4:
@@ -91,6 +92,11 @@ static int flow_offload_fill_route(struct flow_offload *flow,
 	}
 
 	flow_tuple->iifidx = route->tuple[dir].in.ifindex;
+	for (i = 0; i < route->tuple[dir].in.num_vlans; i++) {
+		flow_tuple->in_vlan[i].id = route->tuple[dir].in.vid[i];
+		flow_tuple->in_vlan[i].proto = route->tuple[dir].in.vproto[i];
+	}
+	flow_tuple->in_vlan_num = route->tuple[dir].in.num_vlans;
 
 	switch (route->tuple[dir].xmit_type) {
 	case FLOW_OFFLOAD_XMIT_DIRECT:
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index d10ba09a41b5..c1604de1612c 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -159,17 +159,35 @@ static bool ip_has_options(unsigned int thoff)
 	return thoff != sizeof(struct iphdr);
 }
 
+static void nf_flow_tuple_vlan(struct sk_buff *skb,
+			       struct flow_offload_tuple *tuple)
+{
+	if (skb_vlan_tag_present(skb)) {
+		tuple->in_vlan[0].id = skb_vlan_tag_get(skb);
+		tuple->in_vlan[0].proto = skb->vlan_proto;
+	}
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb_mac_header(skb);
+
+		tuple->in_vlan[1].id = ntohs(veth->h_vlan_TCI);
+		tuple->in_vlan[1].proto = skb->protocol;
+	}
+}
+
 static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
 			    struct flow_offload_tuple *tuple)
 {
-	unsigned int thoff, hdrsize;
+	unsigned int thoff, hdrsize, offset = 0;
 	struct flow_ports *ports;
 	struct iphdr *iph;
 
-	if (!pskb_may_pull(skb, sizeof(*iph)))
+	if (skb->protocol == htons(ETH_P_8021Q))
+		offset += VLAN_HLEN;
+
+	if (!pskb_may_pull(skb, sizeof(*iph) + offset))
 		return -1;
 
-	iph = ip_hdr(skb);
+	iph = (struct iphdr *)(skb_network_header(skb) + offset);
 	thoff = iph->ihl * 4;
 
 	if (ip_is_fragment(iph) ||
@@ -191,11 +209,11 @@ static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
 		return -1;
 
 	thoff = iph->ihl * 4;
-	if (!pskb_may_pull(skb, thoff + hdrsize))
+	if (!pskb_may_pull(skb, thoff + hdrsize + offset))
 		return -1;
 
-	iph = ip_hdr(skb);
-	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+	iph = (struct iphdr *)(skb_network_header(skb) + offset);
+	ports = (struct flow_ports *)(skb_network_header(skb) + thoff + offset);
 
 	tuple->src_v4.s_addr	= iph->saddr;
 	tuple->dst_v4.s_addr	= iph->daddr;
@@ -204,6 +222,7 @@ static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
 	tuple->l3proto		= AF_INET;
 	tuple->l4proto		= iph->protocol;
 	tuple->iifidx		= dev->ifindex;
+	nf_flow_tuple_vlan(skb, tuple);
 
 	return 0;
 }
@@ -248,6 +267,37 @@ static unsigned int nf_flow_xmit_xfrm(struct sk_buff *skb,
 	return NF_STOLEN;
 }
 
+static bool nf_flow_skb_vlan_protocol(const struct sk_buff *skb, __be16 proto)
+{
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		struct vlan_ethhdr *veth;
+
+		veth = (struct vlan_ethhdr *)skb_mac_header(skb);
+		if (veth->h_vlan_encapsulated_proto == proto)
+			return true;
+	}
+
+	return false;
+}
+
+static void nf_flow_vlan_pop(struct sk_buff *skb,
+			     struct flow_offload_tuple_rhash *tuplehash)
+{
+	struct vlan_hdr *vlan_hdr;
+	int i;
+
+	for (i = 0; i < tuplehash->tuple.in_vlan_num; i++) {
+		if (skb_vlan_tag_present(skb)) {
+			__vlan_hwaccel_clear_tag(skb);
+			continue;
+		}
+		vlan_hdr = (struct vlan_hdr *)skb->data;
+		__skb_pull(skb, VLAN_HLEN);
+		vlan_set_encap_proto(skb, vlan_hdr);
+		skb_reset_network_header(skb);
+	}
+}
+
 static unsigned int nf_flow_queue_xmit(struct net *net, struct sk_buff *skb,
 				       const struct flow_offload_tuple_rhash *tuplehash,
 				       unsigned short type)
@@ -280,9 +330,11 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	unsigned int thoff;
 	struct iphdr *iph;
 	__be32 nexthop;
+	u32 offset = 0;
 	int ret;
 
-	if (skb->protocol != htons(ETH_P_IP))
+	if (skb->protocol != htons(ETH_P_IP) &&
+	    !nf_flow_skb_vlan_protocol(skb, htons(ETH_P_IP)))
 		return NF_ACCEPT;
 
 	if (nf_flow_tuple_ip(skb, state->in, &tuple) < 0)
@@ -298,11 +350,15 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
 		return NF_ACCEPT;
 
-	if (skb_try_make_writable(skb, sizeof(*iph)))
+	if (skb->protocol == htons(ETH_P_8021Q))
+		offset += VLAN_HLEN;
+
+	if (skb_try_make_writable(skb, sizeof(*iph) + offset))
 		return NF_DROP;
 
-	thoff = ip_hdr(skb)->ihl * 4;
-	if (nf_flow_state_check(flow, ip_hdr(skb)->protocol, skb, thoff))
+	iph = (struct iphdr *)(skb_network_header(skb) + offset);
+	thoff = (iph->ihl * 4) + offset;
+	if (nf_flow_state_check(flow, iph->protocol, skb, thoff))
 		return NF_ACCEPT;
 
 	flow_offload_refresh(flow_table, flow);
@@ -312,6 +368,9 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 		return NF_ACCEPT;
 	}
 
+	nf_flow_vlan_pop(skb, tuplehash);
+	thoff -= offset;
+
 	if (nf_flow_nat_ip(flow, skb, thoff, dir) < 0)
 		return NF_DROP;
 
@@ -479,14 +538,17 @@ static int nf_flow_nat_ipv6(const struct flow_offload *flow,
 static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev,
 			      struct flow_offload_tuple *tuple)
 {
-	unsigned int thoff, hdrsize;
+	unsigned int thoff, hdrsize, offset = 0;
 	struct flow_ports *ports;
 	struct ipv6hdr *ip6h;
 
-	if (!pskb_may_pull(skb, sizeof(*ip6h)))
+	if (skb->protocol == htons(ETH_P_8021Q))
+		offset += VLAN_HLEN;
+
+	if (!pskb_may_pull(skb, sizeof(*ip6h) + offset))
 		return -1;
 
-	ip6h = ipv6_hdr(skb);
+	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);
 
 	switch (ip6h->nexthdr) {
 	case IPPROTO_TCP:
@@ -503,11 +565,11 @@ static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev,
 		return -1;
 
 	thoff = sizeof(*ip6h);
-	if (!pskb_may_pull(skb, thoff + hdrsize))
+	if (!pskb_may_pull(skb, thoff + hdrsize + offset))
 		return -1;
 
-	ip6h = ipv6_hdr(skb);
-	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);
+	ports = (struct flow_ports *)(skb_network_header(skb) + thoff + offset);
 
 	tuple->src_v6		= ip6h->saddr;
 	tuple->dst_v6		= ip6h->daddr;
@@ -516,6 +578,7 @@ static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev,
 	tuple->l3proto		= AF_INET6;
 	tuple->l4proto		= ip6h->nexthdr;
 	tuple->iifidx		= dev->ifindex;
+	nf_flow_tuple_vlan(skb, tuple);
 
 	return 0;
 }
@@ -533,9 +596,11 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	struct net_device *outdev;
 	struct ipv6hdr *ip6h;
 	struct rt6_info *rt;
+	u32 offset = 0;
 	int ret;
 
-	if (skb->protocol != htons(ETH_P_IPV6))
+	if (skb->protocol != htons(ETH_P_IPV6) &&
+	    !nf_flow_skb_vlan_protocol(skb, htons(ETH_P_IPV6)))
 		return NF_ACCEPT;
 
 	if (nf_flow_tuple_ipv6(skb, state->in, &tuple) < 0)
@@ -551,8 +616,11 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
 		return NF_ACCEPT;
 
-	if (nf_flow_state_check(flow, ipv6_hdr(skb)->nexthdr, skb,
-				sizeof(*ip6h)))
+	if (skb->protocol == htons(ETH_P_8021Q))
+		offset += VLAN_HLEN;
+
+	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + offset);
+	if (nf_flow_state_check(flow, ip6h->nexthdr, skb, sizeof(*ip6h)))
 		return NF_ACCEPT;
 
 	flow_offload_refresh(flow_table, flow);
@@ -562,6 +630,8 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 		return NF_ACCEPT;
 	}
 
+	nf_flow_vlan_pop(skb, tuplehash);
+
 	if (skb_try_make_writable(skb, sizeof(*ip6h)))
 		return NF_DROP;
 
diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 68d03569c293..7a19cadc7021 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -65,6 +65,10 @@ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
 
 struct nft_forward_info {
 	const struct net_device *indev;
+	const struct net_device *vlandev;
+	__u16 vid[NF_FLOW_TABLE_VLAN_MAX];
+	__be16 vproto[NF_FLOW_TABLE_VLAN_MAX];
+	u8 num_vlans;
 	u8 h_source[ETH_ALEN];
 	u8 h_dest[ETH_ALEN];
 	enum flow_offload_xmit_type xmit_type;
@@ -86,6 +90,16 @@ static void nft_dev_path_info(const struct net_device_path_stack *stack,
 			memcpy(info->h_source, ha, ETH_ALEN);
 			break;
 		case DEV_PATH_VLAN:
+			if (info->num_vlans >= NF_FLOW_TABLE_VLAN_MAX) {
+				info->indev = NULL;
+				break;
+			}
+			if (!info->vlandev)
+				info->vlandev = path->dev;
+
+			info->vid[info->num_vlans] = path->vlan.id;
+			info->vproto[info->num_vlans] = path->vlan.proto;
+			info->num_vlans++;
 			break;
 		case DEV_PATH_BRIDGE:
 			memcpy(info->h_dest, path->dev->dev_addr, ETH_ALEN);
@@ -121,6 +135,7 @@ static void nft_dev_forward_path(struct nf_flow_route *route,
 	struct net_device_path_stack stack;
 	struct nft_forward_info info = {};
 	unsigned char ha[ETH_ALEN];
+	int i;
 
 	if (nft_dev_fill_forward_path(route, dst, ct, dir, ha, &stack) >= 0)
 		nft_dev_path_info(&stack, &info, ha);
@@ -129,11 +144,19 @@ static void nft_dev_forward_path(struct nf_flow_route *route,
 		return;
 
 	route->tuple[!dir].in.ifindex = info.indev->ifindex;
+	for (i = 0; i < info.num_vlans; i++) {
+		route->tuple[!dir].in.vid[i] = info.vid[i];
+		route->tuple[!dir].in.vproto[i] = info.vproto[i];
+	}
+	route->tuple[!dir].in.num_vlans = info.num_vlans;
 
 	if (info.xmit_type == FLOW_OFFLOAD_XMIT_DIRECT) {
 		memcpy(route->tuple[dir].out.h_dest, info.h_source, ETH_ALEN);
 		memcpy(route->tuple[dir].out.h_source, info.h_dest, ETH_ALEN);
-		route->tuple[dir].out.ifindex = info.indev->ifindex;
+		if (info.vlandev)
+			route->tuple[dir].out.ifindex = info.vlandev->ifindex;
+		else
+			route->tuple[dir].out.ifindex = info.indev->ifindex;
 		route->tuple[dir].xmit_type = info.xmit_type;
 	}
 }
-- 
2.20.1

[PATCH net-next,v4 9/9] selftests: netfilter: flowtable bridge and VLAN support

[Pablo Neira Ayuso]

This patch adds two new tests to cover bridge and VLAN support:

- Add a bridge device to the Router1 (nsr1) container and attach the
  veth0 device to the bridge. Set the IP address to the bridge device
  to exercise the bridge forwarding path.

- Add VLAN encapsulation between to the bridge device in the Router1 and
  one of the sender containers (ns1).

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v4: no changes.

 .../selftests/netfilter/nft_flowtable.sh      | 82 +++++++++++++++++++
 1 file changed, 82 insertions(+)

diff --git a/tools/testing/selftests/netfilter/nft_flowtable.sh b/tools/testing/selftests/netfilter/nft_flowtable.sh
index 431296c0f91c..427d94816f2d 100755
--- a/tools/testing/selftests/netfilter/nft_flowtable.sh
+++ b/tools/testing/selftests/netfilter/nft_flowtable.sh
@@ -371,6 +371,88 @@ else
 	ip netns exec nsr1 nft list ruleset
 fi
 
+# Another test:
+# Add bridge interface br0 to Router1, with NAT enabled.
+ip -net nsr1 link add name br0 type bridge
+ip -net nsr1 addr flush dev veth0
+ip -net nsr1 link set up dev veth0
+ip -net nsr1 link set veth0 master br0
+ip -net nsr1 addr add 10.0.1.1/24 dev br0
+ip -net nsr1 addr add dead:1::1/64 dev br0
+ip -net nsr1 link set up dev br0
+
+ip netns exec nsr1 sysctl net.ipv4.conf.br0.forwarding=1 > /dev/null
+
+# br0 with NAT enabled.
+ip netns exec nsr1 nft -f - <<EOF
+flush table ip nat
+table ip nat {
+   chain prerouting {
+      type nat hook prerouting priority 0; policy accept;
+      meta iif "br0" ip daddr 10.6.6.6 tcp dport 1666 counter dnat ip to 10.0.2.99:12345
+   }
+
+   chain postrouting {
+      type nat hook postrouting priority 0; policy accept;
+      meta oifname "veth1" counter masquerade
+   }
+}
+EOF
+
+if test_tcp_forwarding_nat ns1 ns2; then
+	echo "PASS: flow offloaded for ns1/ns2 with bridge NAT"
+else
+	echo "FAIL: flow offload for ns1/ns2 with bridge NAT" 1>&2
+	ip netns exec nsr1 nft list ruleset
+	ret=1
+fi
+
+# Another test:
+# Add bridge interface br0 to Router1, with NAT and VLAN.
+ip -net nsr1 link set veth0 nomaster
+ip -net nsr1 link set down dev veth0
+ip -net nsr1 link add link veth0 name veth0.10 type vlan id 10
+ip -net nsr1 link set up dev veth0
+ip -net nsr1 link set up dev veth0.10
+ip -net nsr1 link set veth0.10 master br0
+
+ip -net ns1 addr flush dev eth0
+ip -net ns1 link add link eth0 name eth0.10 type vlan id 10
+ip -net ns1 link set eth0 up
+ip -net ns1 link set eth0.10 up
+ip -net ns1 addr add 10.0.1.99/24 dev eth0.10
+ip -net ns1 route add default via 10.0.1.1
+ip -net ns1 addr add dead:1::99/64 dev eth0.10
+
+if test_tcp_forwarding_nat ns1 ns2; then
+	echo "PASS: flow offloaded for ns1/ns2 with bridge NAT and VLAN"
+else
+	echo "FAIL: flow offload for ns1/ns2 with bridge NAT and VLAN" 1>&2
+	ip netns exec nsr1 nft list ruleset
+	ret=1
+fi
+
+# restore test topology (remove bridge and VLAN)
+ip -net nsr1 link set veth0 nomaster
+ip -net nsr1 link set veth0 down
+ip -net nsr1 link set veth0.10 down
+ip -net nsr1 link delete veth0.10 type vlan
+ip -net nsr1 link delete br0 type bridge
+ip -net ns1 addr flush dev eth0.10
+ip -net ns1 link set eth0.10 down
+ip -net ns1 link set eth0 down
+ip -net ns1 link delete eth0.10 type vlan
+
+# restore address in ns1 and nsr1
+ip -net ns1 link set eth0 up
+ip -net ns1 addr add 10.0.1.99/24 dev eth0
+ip -net ns1 route add default via 10.0.1.1
+ip -net ns1 addr add dead:1::99/64 dev eth0
+ip -net ns1 route add default via dead:1::1
+ip -net nsr1 addr add 10.0.1.1/24 dev veth0
+ip -net nsr1 addr add dead:1::1/64 dev veth0
+ip -net nsr1 link set up dev veth0
+
 KEY_SHA="0x"$(ps -xaf | sha1sum | cut -d " " -f 1)
 KEY_AES="0x"$(ps -xaf | md5sum | cut -d " " -f 1)
 SPI1=$RANDOM
-- 
2.20.1

Re: [PATCH net-next,v4 3/9] net: resolve forwarding path from virtual netdevice and HW destination address

[Florian Westphal]

Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> +#define NET_DEVICE_PATH_STACK_MAX	5
> +
> +struct net_device_path_stack {
> +	int			num_paths;
> +	struct net_device_path	path[NET_DEVICE_PATH_STACK_MAX];
> +};

[..]

> +int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
> +			  struct net_device_path_stack *stack)
> +{
> +	const struct net_device *last_dev;
> +	struct net_device_path_ctx ctx = {
> +		.dev	= dev,
> +		.daddr	= daddr,
> +	};
> +	struct net_device_path *path;
> +	int ret = 0, k;
> +
> +	stack->num_paths = 0;
> +	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
> +		last_dev = ctx.dev;
> +		k = stack->num_paths++;
> +		if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
> +			return -1;

This guarantees k < NET_DEVICE_PATH_STACK_MAX, so we can fill
entire path[].

> +		path = &stack->path[k];
> +		memset(path, 0, sizeof(struct net_device_path));
> +
> +		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
> +		if (ret < 0)
> +			return -1;
> +
> +		if (WARN_ON_ONCE(last_dev == ctx.dev))
> +			return -1;
> +	}

... but this means that stack->num_paths == NET_DEVICE_PATH_STACK_MAX
is possible, with k being last element.

> +	path = &stack->path[stack->num_paths++];

... so this may result in a off by one?

Re: [PATCH net-next,v4 2/9] netfilter: flowtable: add xmit path types

[Florian Westphal]

Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> -	if (unlikely(dst_xfrm(&rt->dst))) {
> +	rt = (struct rtable *)tuplehash->tuple.dst_cache;
> +
> +	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_XFRM)) {
>  		memset(skb->cb, 0, sizeof(struct inet_skb_parm));
>  		IPCB(skb)->iif = skb->dev->ifindex;
>  		IPCB(skb)->flags = IPSKB_FORWARDED;
>  		return nf_flow_xmit_xfrm(skb, state, &rt->dst);
>  	}
[..]

> +
> +	if (unlikely(tuplehash->tuple.xmit_type == FLOW_OFFLOAD_XMIT_NEIGH))

This needs to be XMIT_XFRM too.