[PATCH net-next v4 0/2] Bare UDP L3 Encapsulation Module

[PATCH net-next v4 0/2] Bare UDP L3 Encapsulation Module

[Martin Varghese]

From: Martin Varghese <martin.varghese@nokia.com>

There are various L3 encapsulation standards using UDP being discussed to
leverage the UDP based load balancing capability of different networks.
MPLSoUDP (__ https://tools.ietf.org/html/rfc7510) is one among them.

The Bareudp tunnel module provides a generic L3 encapsulation tunnelling
support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside
a UDP tunnel.

Special Handling
----------------
The bareudp device supports special handling for MPLS & IP as they can have
multiple ethertypes.
MPLS procotcol can have ethertypes ETH_P_MPLS_UC  (unicast) & ETH_P_MPLS_MC (multicast).
IP protocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6).
This special handling can be enabled only for ethertypes ETH_P_IP & ETH_P_MPLS_UC
with a flag called multiproto mode.

Usage
------

1) Device creation & deletion

    a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype 0x8847.

       This creates a bareudp tunnel device which tunnels L3 traffic with ethertype
       0x8847 (MPLS traffic). The destination port of the UDP header will be set to
       6635.The device will listen on UDP port 6635 to receive traffic.

    b) ip link delete bareudp0

2) Device creation with multiple proto mode enabled

There are two ways to create a bareudp device for MPLS & IP with multiproto mode
enabled.

    a) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype 0x8847 multiproto

    b) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype mpls

3) Device Usage

The bareudp device could be used along with OVS or flower filter in TC.
The OVS or TC flower layer must set the tunnel information in SKB dst field before
sending packet buffer to the bareudp device for transmission. On reception the
bareudp device extracts and stores the tunnel information in SKB dst field before
passing the packet buffer to the network stack.

Why not FOU ?
------------
FOU by design does l4 encapsulation.It maps udp port to ipproto (IP protocol number
for l4 protocol).

Bareudp acheives a generic l3 encapsulation.It maps udp port to l3 ethertype

Martin Varghese (2):
  net: UDP tunnel encapsulation module for  tunnelling different
    protocols like     MPLS,IP,NSH etc.
  net: Special handling for IP & MPLS.

 Documentation/networking/bareudp.rst |  53 +++
 Documentation/networking/index.rst   |   1 +
 drivers/net/Kconfig                  |  13 +
 drivers/net/Makefile                 |   1 +
 drivers/net/bareudp.c                | 801 +++++++++++++++++++++++++++++++++++
 include/net/bareudp.h                |  20 +
 include/net/ip6_tunnel.h             |  50 +++
 include/net/ip_tunnels.h             |  47 ++
 include/uapi/linux/if_link.h         |  12 +
 9 files changed, 998 insertions(+)
 create mode 100644 Documentation/networking/bareudp.rst
 create mode 100644 drivers/net/bareudp.c
 create mode 100644 include/net/bareudp.h

-- 
1.8.3.1

[PATCH net-next v4 1/2] net: UDP tunnel encapsulation module for

[Martin Varghese]

From: Martin Varghese <martin.varghese@nokia.com>

The Bareudp tunnel module provides a generic L3 encapsulation
tunnelling module for tunnelling different protocols like MPLS,
IP,NSH etc inside a UDP tunnel.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
---
Changes in v2:
     - Fixed documentation errors.
     - Converted documentation to rst format.
     - Moved ip tunnel rt lookup code to a common location.
     - Removed seperate v4 and v6 socket.
     - Added call to skb_ensure_writable before updating ethernet header.
     - Simplified bareudp_destroy_tunnels as deleting devices under a
       namespace is taken care be the default pernet exit code.
     - Fixed bareudp_change_mtu.

Changes in v3:
     - Re-sending the patch again.

Changes in v4:
     - Converted bareudp device to l3 device.
     - Removed redundant fields in bareudp device.

 Documentation/networking/bareudp.rst |  35 ++
 Documentation/networking/index.rst   |   1 +
 drivers/net/Kconfig                  |  13 +
 drivers/net/Makefile                 |   1 +
 drivers/net/bareudp.c                | 741 +++++++++++++++++++++++++++++++++++
 include/net/bareudp.h                |  19 +
 include/net/ip6_tunnel.h             |  50 +++
 include/net/ip_tunnels.h             |  47 +++
 include/uapi/linux/if_link.h         |  11 +
 9 files changed, 918 insertions(+)
 create mode 100644 Documentation/networking/bareudp.rst
 create mode 100644 drivers/net/bareudp.c
 create mode 100644 include/net/bareudp.h

diff --git a/Documentation/networking/bareudp.rst b/Documentation/networking/bareudp.rst
new file mode 100644
index 0000000..4087a1b
--- /dev/null
+++ b/Documentation/networking/bareudp.rst
@@ -0,0 +1,35 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========================================
+Bare UDP Tunnelling Module Documentation
+========================================
+
+There are various L3 encapsulation standards using UDP being discussed to
+leverage the UDP based load balancing capability of different networks.
+MPLSoUDP (__ https://tools.ietf.org/html/rfc7510) is one among them.
+
+The Bareudp tunnel module provides a generic L3 encapsulation tunnelling
+support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside
+a UDP tunnel.
+
+Usage
+------
+
+1) Device creation & deletion
+
+    a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype 0x8847.
+
+       This creates a bareudp tunnel device which tunnels L3 traffic with ethertype
+       0x8847 (MPLS traffic). The destination port of the UDP header will be set to
+       6635.The device will listen on UDP port 6635 to receive traffic.
+
+    b) ip link delete bareudp0
+
+2) Device Usage
+
+The bareudp device could be used along with OVS or flower filter in TC.
+The OVS or TC flower layer must set the tunnel information in SKB dst field before
+sending packet buffer to the bareudp device for transmission. On reception the
+bareudp device extracts and stores the tunnel information in SKB dst field before
+passing the packet buffer to the network stack.
+
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index d07d985..ea3d604 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -33,6 +33,7 @@ Contents:
    tls
    tls-offload
    nfc
+   bareudp
 
 .. only::  subproject and html
 
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index dee7958..9726447 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -258,6 +258,19 @@ config GENEVE
 	  To compile this driver as a module, choose M here: the module
 	  will be called geneve.
 
+config BAREUDP
+       tristate "Bare UDP Encapsulation"
+       depends on INET && NET_UDP_TUNNEL
+       depends on IPV6 || !IPV6
+       select NET_IP_TUNNEL
+       select GRO_CELLS
+       help
+          This adds a bare UDP tunnel module for tunnelling different
+          kinds of traffic like MPLS, IP, etc. inside a UDP tunnel.
+
+          To compile this driver as a module, choose M here: the module
+          will be called bareudp.
+
 config GTP
 	tristate "GPRS Tunneling Protocol datapath (GTP-U)"
 	depends on INET
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 953b7c1..567b1aa49 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_VETH) += veth.o
 obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
 obj-$(CONFIG_VXLAN) += vxlan.o
 obj-$(CONFIG_GENEVE) += geneve.o
+obj-$(CONFIG_BAREUDP) += bareudp.o
 obj-$(CONFIG_GTP) += gtp.o
 obj-$(CONFIG_NLMON) += nlmon.o
 obj-$(CONFIG_NET_VRF) += vrf.o
diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
new file mode 100644
index 0000000..a0646e2
--- /dev/null
+++ b/drivers/net/bareudp.c
@@ -0,0 +1,741 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Bareudp: UDP  tunnel encasulation for different Payload types like
+ * MPLS, NSH, IP, etc.
+ * Copyright (c) 2019 Nokia, Inc.
+ * Authors:  Martin Varghese, <martin.varghese@nokia.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <linux/hash.h>
+#include <net/dst_metadata.h>
+#include <net/gro_cells.h>
+#include <net/rtnetlink.h>
+#include <net/protocol.h>
+#include <net/ip6_tunnel.h>
+#include <net/ip_tunnels.h>
+#include <net/udp_tunnel.h>
+#include <net/bareudp.h>
+
+#define BAREUDP_BASE_HLEN sizeof(struct udphdr)
+#define BAREUDP_IPV4_HLEN (sizeof(struct iphdr) + \
+			   sizeof(struct udphdr))
+#define BAREUDP_IPV6_HLEN (sizeof(struct ipv6hdr) + \
+			   sizeof(struct udphdr))
+
+static bool log_ecn_error = true;
+module_param(log_ecn_error, bool, 0644);
+MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
+
+/* per-network namespace private data for this module */
+
+static unsigned int bareudp_net_id;
+
+struct bareudp_net {
+	struct list_head        bareudp_list;
+};
+
+/* Pseudo network device */
+struct bareudp_dev {
+	struct net         *net;        /* netns for packet i/o */
+	struct net_device  *dev;        /* netdev for bareudp tunnel */
+	__be16		   ethertype;
+	__be16             port;
+	u16	           sport_min;
+	struct socket      __rcu *sock;
+	struct list_head   next;        /* bareudp node  on namespace list */
+	struct gro_cells   gro_cells;
+};
+
+static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
+{
+	struct bareudp_dev *bareudp;
+	struct metadata_dst *tun_dst = NULL;
+	struct pcpu_sw_netstats *stats;
+	unsigned int len;
+	int err = 0;
+	void *oiph;
+	u16 proto;
+	unsigned short family;
+
+	if (unlikely(!pskb_may_pull(skb, BAREUDP_BASE_HLEN)))
+		goto drop;
+
+	bareudp = rcu_dereference_sk_user_data(sk);
+	if (!bareudp)
+		goto drop;
+
+	if (skb->protocol ==  htons(ETH_P_IP))
+		family = AF_INET;
+	else
+		family = AF_INET6;
+
+	proto = bareudp->ethertype;
+
+	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
+				 proto,
+				 !net_eq(bareudp->net,
+				 dev_net(bareudp->dev)))) {
+		bareudp->dev->stats.rx_dropped++;
+		goto drop;
+	}
+
+	tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
+	if (!tun_dst) {
+		bareudp->dev->stats.rx_dropped++;
+		goto drop;
+	}
+	skb_dst_set(skb, &tun_dst->dst);
+	skb->dev = bareudp->dev;
+	oiph = skb_network_header(skb);
+	skb_reset_network_header(skb);
+
+	if (family == AF_INET)
+		err = IP_ECN_decapsulate(oiph, skb);
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		err = IP6_ECN_decapsulate(oiph, skb);
+#endif
+
+	if (unlikely(err)) {
+		if (log_ecn_error) {
+			if  (family == AF_INET)
+				net_info_ratelimited("non-ECT from %pI4 "
+						     "with TOS=%#x\n",
+						     &((struct iphdr *)oiph)->saddr,
+						     ((struct iphdr *)oiph)->tos);
+#if IS_ENABLED(CONFIG_IPV6)
+			else
+				net_info_ratelimited("non-ECT from %pI6\n",
+						     &((struct ipv6hdr *)oiph)->saddr);
+#endif
+		}
+		if (err > 1) {
+			++bareudp->dev->stats.rx_frame_errors;
+			++bareudp->dev->stats.rx_errors;
+			goto drop;
+		}
+	}
+
+	len = skb->len;
+	err = gro_cells_receive(&bareudp->gro_cells, skb);
+	if (likely(err == NET_RX_SUCCESS)) {
+		stats = this_cpu_ptr(bareudp->dev->tstats);
+		u64_stats_update_begin(&stats->syncp);
+		stats->rx_packets++;
+		stats->rx_bytes += len;
+		u64_stats_update_end(&stats->syncp);
+	}
+	return 0;
+drop:
+	/* Consume bad packet */
+	kfree_skb(skb);
+
+	return 0;
+}
+
+static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
+{
+	return 0;
+}
+
+static int bareudp_init(struct net_device *dev)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+	int err;
+
+	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+	if (!dev->tstats)
+		return -ENOMEM;
+
+	err = gro_cells_init(&bareudp->gro_cells, dev);
+	if (err) {
+		free_percpu(dev->tstats);
+		return err;
+	}
+	return 0;
+}
+
+static void bareudp_uninit(struct net_device *dev)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+
+	gro_cells_destroy(&bareudp->gro_cells);
+	free_percpu(dev->tstats);
+}
+
+static struct socket *bareudp_create_sock(struct net *net, __be16 port)
+{
+	struct socket *sock;
+	struct udp_port_cfg udp_conf;
+	int err;
+
+	memset(&udp_conf, 0, sizeof(udp_conf));
+#if IS_ENABLED(CONFIG_IPV6)
+	udp_conf.family = AF_INET6;
+#else
+	udp_conf.family = AF_INET;
+#endif
+	udp_conf.local_udp_port = port;
+	/* Open UDP socket */
+	err = udp_sock_create(net, &udp_conf, &sock);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	return sock;
+}
+
+/* Create new listen socket if needed */
+static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
+{
+	struct socket *sock;
+	struct udp_tunnel_sock_cfg tunnel_cfg;
+
+	sock = bareudp_create_sock(bareudp->net, port);
+	if (IS_ERR(sock))
+		return PTR_ERR(sock);
+
+	/* Mark socket as an encapsulation socket */
+	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
+	tunnel_cfg.sk_user_data = bareudp;
+	tunnel_cfg.encap_type = 1;
+	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
+	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
+	tunnel_cfg.encap_destroy = NULL;
+	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
+
+	if (sock->sk->sk_family == AF_INET6)
+		udp_encap_enable();
+
+	rcu_assign_pointer(bareudp->sock, sock);
+	return 0;
+}
+
+static int bareudp_open(struct net_device *dev)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+	int ret = 0;
+
+	ret =  bareudp_socket_create(bareudp, bareudp->port);
+	return ret;
+}
+
+static void bareudp_sock_release(struct bareudp_dev *bareudp)
+{
+	struct socket *sock;
+
+	sock = bareudp->sock;
+	rcu_assign_pointer(bareudp->sock, NULL);
+	synchronize_net();
+	udp_tunnel_sock_release(sock);
+}
+
+static int bareudp_stop(struct net_device *dev)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+
+	bareudp_sock_release(bareudp);
+	return 0;
+}
+
+static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
+			    struct bareudp_dev *bareudp,
+			    const struct ip_tunnel_info *info)
+{
+	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
+	struct socket *sock = rcu_dereference(bareudp->sock);
+	const struct ip_tunnel_key *key = &info->key;
+	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
+	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
+	int err;
+	struct rtable *rt;
+	struct flowi4 fl4;
+	__u8 tos, ttl;
+	__be16 sport;
+	__be16 df;
+	int min_headroom;
+
+	if (!sock)
+		return -ESHUTDOWN;
+
+	rt = iptunnel_get_rt(skb, dev, bareudp->net, &fl4, info,
+			     use_cache);
+	if (IS_ERR(rt))
+		return PTR_ERR(rt);
+
+	skb_tunnel_check_pmtu(skb, &rt->dst,
+			      BAREUDP_IPV4_HLEN + info->options_len);
+
+	sport = udp_flow_src_port(bareudp->net, skb,
+				  bareudp->sport_min, USHRT_MAX,
+				  true);
+	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
+	ttl = key->ttl;
+	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
+	skb_scrub_packet(skb, xnet);
+
+	if (!skb_pull(skb, skb_network_offset(skb)))
+		goto free_dst;
+
+	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
+		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
+
+	err = skb_cow_head(skb, min_headroom);
+	if (unlikely(err))
+		goto free_dst;
+
+	err = udp_tunnel_handle_offloads(skb, udp_sum);
+	if (err)
+		goto free_dst;
+
+	skb_set_inner_protocol(skb, bareudp->ethertype);
+	udp_tunnel_xmit_skb(rt, sock->sk, skb, fl4.saddr, fl4.daddr,
+			    tos, ttl, df, sport, bareudp->port,
+			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
+			    !(info->key.tun_flags & TUNNEL_CSUM));
+	return 0;
+
+free_dst:
+	dst_release(&rt->dst);
+	return err;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
+			     struct bareudp_dev *bareudp,
+			     const struct ip_tunnel_info *info)
+{
+	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
+	struct socket *sock  = rcu_dereference(bareudp->sock);
+	const struct ip_tunnel_key *key = &info->key;
+	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
+	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
+	struct dst_entry *dst = NULL;
+	struct flowi6 fl6;
+	__u8 prio, ttl;
+	__be16 sport;
+	int min_headroom;
+	int err;
+
+	if (!sock)
+		return -ESHUTDOWN;
+
+	dst = ip6tunnel_get_dst(skb, dev, bareudp->net, sock, &fl6, info,
+				use_cache);
+	if (IS_ERR(dst))
+		return PTR_ERR(dst);
+
+	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len);
+
+	sport = udp_flow_src_port(bareudp->net, skb,
+				  bareudp->sport_min, USHRT_MAX,
+				  true);
+	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
+	ttl = key->ttl;
+
+	skb_scrub_packet(skb, xnet);
+
+	if (!skb_pull(skb, skb_network_offset(skb)))
+		goto free_dst;
+
+	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
+		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
+
+	err = skb_cow_head(skb, min_headroom);
+	if (unlikely(err))
+		goto free_dst;
+
+	err = udp_tunnel_handle_offloads(skb, udp_sum);
+	if (err)
+		goto free_dst;
+
+	udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
+			     &fl6.saddr, &fl6.daddr, prio, ttl,
+			     info->key.label, sport, bareudp->port,
+			     !(info->key.tun_flags & TUNNEL_CSUM));
+	return 0;
+
+free_dst:
+	dst_release(dst);
+	return err;
+}
+#endif
+
+static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+	struct ip_tunnel_info *info = NULL;
+	int err;
+
+	if (skb->protocol != bareudp->ethertype) {
+		err = -EINVAL;
+		goto tx_error;
+	}
+
+	info = skb_tunnel_info(skb);
+	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
+		err = -EINVAL;
+		goto tx_error;
+	}
+
+	rcu_read_lock();
+#if IS_ENABLED(CONFIG_IPV6)
+	if (info->mode & IP_TUNNEL_INFO_IPV6)
+		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
+	else
+#endif
+		err = bareudp_xmit_skb(skb, dev, bareudp, info);
+
+	rcu_read_unlock();
+
+	if (likely(!err))
+		return NETDEV_TX_OK;
+tx_error:
+	dev_kfree_skb(skb);
+
+	if (err == -ELOOP)
+		dev->stats.collisions++;
+	else if (err == -ENETUNREACH)
+		dev->stats.tx_carrier_errors++;
+
+	dev->stats.tx_errors++;
+	return NETDEV_TX_OK;
+}
+
+static int bareudp_change_mtu(struct net_device *dev, int new_mtu)
+{
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+static int bareudp_fill_metadata_dst(struct net_device *dev,
+				     struct sk_buff *skb)
+{
+	struct ip_tunnel_info *info = skb_tunnel_info(skb);
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
+	int ret;
+
+	if (ip_tunnel_info_af(info) == AF_INET) {
+		struct rtable *rt;
+		struct flowi4 fl4;
+
+		rt = iptunnel_get_rt(skb, dev, bareudp->net, &fl4, info,
+				     use_cache);
+		if (IS_ERR(rt))
+			return PTR_ERR(rt);
+
+		ip_rt_put(rt);
+		info->key.u.ipv4.src = fl4.saddr;
+#if IS_ENABLED(CONFIG_IPV6)
+	} else if (ip_tunnel_info_af(info) == AF_INET6) {
+		struct dst_entry *dst;
+		struct flowi6 fl6;
+		struct socket *sock = rcu_dereference(bareudp->sock);
+
+		dst = ip6tunnel_get_dst(skb, dev, bareudp->net, sock, &fl6,
+					info, use_cache);
+		if (IS_ERR(dst))
+			return PTR_ERR(dst);
+
+		dst_release(dst);
+		info->key.u.ipv6.src = fl6.saddr;
+#endif
+	} else {
+		return -EINVAL;
+	}
+
+	info->key.tp_src = udp_flow_src_port(bareudp->net, skb,
+					     bareudp->sport_min,
+			USHRT_MAX, true);
+	info->key.tp_dst = bareudp->port;
+	return ret;
+}
+
+static const struct net_device_ops bareudp_netdev_ops = {
+	.ndo_init               = bareudp_init,
+	.ndo_uninit             = bareudp_uninit,
+	.ndo_open               = bareudp_open,
+	.ndo_stop               = bareudp_stop,
+	.ndo_start_xmit         = bareudp_xmit,
+	.ndo_get_stats64        = ip_tunnel_get_stats64,
+	.ndo_change_mtu         = bareudp_change_mtu,
+	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
+};
+
+static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
+	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
+	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
+	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
+};
+
+/* Info for udev, that this is a virtual tunnel endpoint */
+static struct device_type bareudp_type = {
+	.name = "bareudp",
+};
+
+/* Initialize the device structure. */
+static void bareudp_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &bareudp_netdev_ops;
+	dev->needs_free_netdev = true;
+	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
+	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
+	dev->features    |= NETIF_F_RXCSUM;
+	dev->features    |= NETIF_F_GSO_SOFTWARE;
+	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
+	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+	dev->hard_header_len = 0;
+	dev->addr_len = 0;
+	dev->mtu = 1500;
+	dev->min_mtu = IPV4_MIN_MTU;
+	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
+	dev->type = ARPHRD_NONE;
+	netif_keep_dst(dev);
+	dev->priv_flags |= IFF_NO_QUEUE;
+	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+}
+
+static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
+			    struct netlink_ext_ack *extack)
+{
+	if (!data) {
+		NL_SET_ERR_MSG(extack,
+			       "Not enough attributes provided to perform the operation");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf)
+{
+	if (!data[IFLA_BAREUDP_PORT] || !data[IFLA_BAREUDP_ETHERTYPE])
+		return -EINVAL;
+
+	if (data[IFLA_BAREUDP_PORT])
+		conf->port =  nla_get_u16(data[IFLA_BAREUDP_PORT]);
+
+	if (data[IFLA_BAREUDP_ETHERTYPE])
+		conf->ethertype =  nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
+
+	if (data[IFLA_BAREUDP_SRCPORT_MIN])
+		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
+
+	return 0;
+}
+
+static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
+					    const struct bareudp_conf *conf)
+{
+	struct bareudp_dev *bareudp, *t = NULL;
+
+	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
+		if (conf->port == bareudp->port)
+			t = bareudp;
+	}
+	return t;
+}
+
+static int bareudp_configure(struct net *net, struct net_device *dev,
+			     struct bareudp_conf *conf)
+{
+	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
+	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
+	int err;
+
+	bareudp->net = net;
+	bareudp->dev = dev;
+	t = bareudp_find_dev(bn, conf);
+	if (t)
+		return -EBUSY;
+
+	bareudp->port = conf->port;
+	bareudp->ethertype = conf->ethertype;
+	bareudp->sport_min = conf->sport_min;
+	err = register_netdevice(dev);
+	if (err)
+		return err;
+
+	list_add(&bareudp->next, &bn->bareudp_list);
+	return 0;
+}
+
+static void bareudp_link_config(struct net_device *dev,
+				struct nlattr *tb[])
+{
+	if (tb[IFLA_MTU])
+		bareudp_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
+}
+
+static int bareudp_newlink(struct net *net, struct net_device *dev,
+			   struct nlattr *tb[], struct nlattr *data[],
+			   struct netlink_ext_ack *extack)
+{
+	struct bareudp_conf conf;
+	int err;
+
+	err = bareudp2info(data, &conf);
+	if (err)
+		return err;
+
+	err = bareudp_configure(net, dev, &conf);
+	if (err)
+		return err;
+
+	bareudp_link_config(dev, tb);
+	return 0;
+}
+
+static void bareudp_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+
+	list_del(&bareudp->next);
+	unregister_netdevice_queue(dev, head);
+}
+
+static size_t bareudp_get_size(const struct net_device *dev)
+{
+	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
+		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
+		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
+		0;
+}
+
+static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct bareudp_dev *bareudp = netdev_priv(dev);
+
+	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
+		goto nla_put_failure;
+	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
+		goto nla_put_failure;
+	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
+	.kind           = "bareudp",
+	.maxtype        = IFLA_BAREUDP_MAX,
+	.policy         = bareudp_policy,
+	.priv_size      = sizeof(struct bareudp_dev),
+	.setup          = bareudp_setup,
+	.validate       = bareudp_validate,
+	.newlink        = bareudp_newlink,
+	.dellink        = bareudp_dellink,
+	.get_size       = bareudp_get_size,
+	.fill_info      = bareudp_fill_info,
+};
+
+struct net_device *bareudp_dev_create(struct net *net, const char *name,
+				      u8 name_assign_type,
+				      struct bareudp_conf *conf)
+{
+	struct nlattr *tb[IFLA_MAX + 1];
+	struct net_device *dev;
+	LIST_HEAD(list_kill);
+	int err;
+
+	memset(tb, 0, sizeof(tb));
+	dev = rtnl_create_link(net, name, name_assign_type,
+			       &bareudp_link_ops, tb, NULL);
+	if (IS_ERR(dev))
+		return dev;
+
+	err = bareudp_configure(net, dev, conf);
+	if (err) {
+		free_netdev(dev);
+		return ERR_PTR(err);
+	}
+	err = bareudp_change_mtu(dev, IP_MAX_MTU);
+	if (err)
+		goto err;
+
+	err = rtnl_configure_link(dev, NULL);
+	if (err < 0)
+		goto err;
+
+	return dev;
+err:
+	bareudp_dellink(dev, &list_kill);
+	unregister_netdevice_many(&list_kill);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(bareudp_dev_create);
+
+static __net_init int bareudp_init_net(struct net *net)
+{
+	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
+
+	INIT_LIST_HEAD(&bn->bareudp_list);
+	return 0;
+}
+
+static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
+{
+	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
+	struct bareudp_dev *bareudp, *next;
+
+	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
+		unregister_netdevice_queue(bareudp->dev, head);
+}
+
+static void __net_exit bareudp_exit_batch_net(struct list_head *net_list)
+{
+	struct net *net;
+	LIST_HEAD(list);
+
+	rtnl_lock();
+	list_for_each_entry(net, net_list, exit_list)
+		bareudp_destroy_tunnels(net, &list);
+
+	/* unregister the devices gathered above */
+	unregister_netdevice_many(&list);
+	rtnl_unlock();
+}
+
+static struct pernet_operations bareudp_net_ops = {
+	.init = bareudp_init_net,
+	.exit_batch = bareudp_exit_batch_net,
+	.id   = &bareudp_net_id,
+	.size = sizeof(struct bareudp_net),
+};
+
+static int __init bareudp_init_module(void)
+{
+	int rc;
+
+	rc = register_pernet_subsys(&bareudp_net_ops);
+	if (rc)
+		goto out1;
+
+	rc = rtnl_link_register(&bareudp_link_ops);
+	if (rc)
+		goto out2;
+
+	return 0;
+out2:
+	unregister_pernet_subsys(&bareudp_net_ops);
+out1:
+	return rc;
+}
+late_initcall(bareudp_init_module);
+
+static void __exit bareudp_cleanup_module(void)
+{
+	rtnl_link_unregister(&bareudp_link_ops);
+	unregister_pernet_subsys(&bareudp_net_ops);
+}
+module_exit(bareudp_cleanup_module);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
+MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
diff --git a/include/net/bareudp.h b/include/net/bareudp.h
new file mode 100644
index 0000000..513fae6
--- /dev/null
+++ b/include/net/bareudp.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __NET_BAREUDP_H
+#define __NET_BAREUDP_H
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+
+struct bareudp_conf {
+	__be16 ethertype;
+	__be16 port;
+	u16 sport_min;
+};
+
+struct net_device *bareudp_dev_create(struct net *net, const char *name,
+				      u8 name_assign_type,
+				      struct bareudp_conf *info);
+
+#endif
diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h
index 028eaea..8215d1b 100644
--- a/include/net/ip6_tunnel.h
+++ b/include/net/ip6_tunnel.h
@@ -165,5 +165,55 @@ static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
 		iptunnel_xmit_stats(dev, pkt_len);
 	}
 }
+
+static inline struct dst_entry *ip6tunnel_get_dst(struct sk_buff *skb,
+						  struct net_device *dev,
+						  struct net *net,
+						  struct socket *sock,
+						  struct flowi6 *fl6,
+						  const struct ip_tunnel_info *info,
+						  bool use_cache)
+{
+	struct dst_entry *dst = NULL;
+#ifdef CONFIG_DST_CACHE
+	struct dst_cache *dst_cache;
+#endif
+	__u8 prio;
+
+	memset(fl6, 0, sizeof(*fl6));
+	fl6->flowi6_mark = skb->mark;
+	fl6->flowi6_proto = IPPROTO_UDP;
+	fl6->daddr = info->key.u.ipv6.dst;
+	fl6->saddr = info->key.u.ipv6.src;
+	prio = info->key.tos;
+
+	fl6->flowlabel = ip6_make_flowinfo(RT_TOS(prio),
+					   info->key.label);
+#ifdef CONFIG_DST_CACHE
+	dst_cache = (struct dst_cache *)&info->dst_cache;
+	if (use_cache) {
+		dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
+		if (dst)
+			return dst;
+	}
+#endif
+	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, fl6,
+					      NULL);
+	if (IS_ERR(dst)) {
+		netdev_dbg(dev, "no route to %pI6\n", &fl6->daddr);
+		return ERR_PTR(-ENETUNREACH);
+	}
+	if (dst->dev == dev) { /* is this necessary? */
+		netdev_dbg(dev, "circular route to %pI6\n", &fl6->daddr);
+		dst_release(dst);
+		return ERR_PTR(-ELOOP);
+	}
+#ifdef CONFIG_DST_CACHE
+	if (use_cache)
+		dst_cache_set_ip6(dst_cache, dst, &fl6->saddr);
+#endif
+	return dst;
+}
+
 #endif
 #endif
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 236503a..a79c3a6 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -490,6 +490,53 @@ static inline int ip_tunnel_collect_metadata(void)
 	return static_branch_unlikely(&ip_tunnel_metadata_cnt);
 }
 
+static inline  struct rtable *iptunnel_get_rt(struct sk_buff *skb,
+					      struct net_device *dev,
+					      struct net *net,
+					      struct flowi4 *fl4,
+					      const struct ip_tunnel_info *info,
+					      bool  use_cache)
+{
+#ifdef CONFIG_DST_CACHE
+	struct dst_cache *dst_cache;
+#endif
+	struct rtable *rt = NULL;
+	__u8 tos;
+
+	memset(fl4, 0, sizeof(*fl4));
+	fl4->flowi4_mark = skb->mark;
+	fl4->flowi4_proto = IPPROTO_UDP;
+	fl4->daddr = info->key.u.ipv4.dst;
+	fl4->saddr = info->key.u.ipv4.src;
+
+	tos = info->key.tos;
+	fl4->flowi4_tos = RT_TOS(tos);
+
+#ifdef CONFIG_DST_CACHE
+	dst_cache = (struct dst_cache *)&info->dst_cache;
+	if (use_cache) {
+		rt = dst_cache_get_ip4(dst_cache, &fl4->saddr);
+		if (rt)
+			return rt;
+	}
+#endif
+	rt = ip_route_output_key(net, fl4);
+	if (IS_ERR(rt)) {
+		netdev_dbg(dev, "no route to %pI4\n", &fl4->daddr);
+		return ERR_PTR(-ENETUNREACH);
+	}
+	if (rt->dst.dev == dev) { /* is this necessary? */
+		netdev_dbg(dev, "circular route to %pI4\n", &fl4->daddr);
+		ip_rt_put(rt);
+		return ERR_PTR(-ELOOP);
+	}
+#ifdef CONFIG_DST_CACHE
+	if (use_cache)
+		dst_cache_set_ip4(dst_cache, &rt->dst, fl4->saddr);
+#endif
+	return rt;
+}
+
 void __init ip_tunnel_core_init(void);
 
 void ip_tunnel_need_metadata(void);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 024af2d..fb4b33a 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -590,6 +590,17 @@ enum ifla_geneve_df {
 	GENEVE_DF_MAX = __GENEVE_DF_END - 1,
 };
 
+/* Bareudp section  */
+enum {
+	IFLA_BAREUDP_UNSPEC,
+	IFLA_BAREUDP_PORT,
+	IFLA_BAREUDP_ETHERTYPE,
+	IFLA_BAREUDP_SRCPORT_MIN,
+	__IFLA_BAREUDP_MAX
+};
+
+#define IFLA_BAREUDP_MAX (__IFLA_BAREUDP_MAX - 1)
+
 /* PPP section */
 enum {
 	IFLA_PPP_UNSPEC,
-- 
1.8.3.1

[PATCH net-next v4 2/2] net: Special handling for IP & MPLS.

[Martin Varghese]

From: Martin Varghese <martin.varghese@nokia.com>

Special handling is needed in bareudp module for IP & MPLS as they
support more than one ethertypes.

MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
While decapsulating MPLS packet from UDP packet the tunnel destination IP
address is checked to determine the ethertype. The ethertype of the packet
will be set to 0x8848 if the  tunnel destination IP address is a multicast
IP address. The ethertype of the packet will be set to 0x8847 if the
tunnel destination IP address is a unicast IP address.

IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version
field of the IP header tunnelled will be checked to determine the ethertype.

This special handling to tunnel additional ethertypes will be disabled
by default and can be enabled using a flag called ext mode. This flag can
be used only with ethertypes 0x8847 and 0x0800.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
---
Changes in v2:
    - Fixed documentation errors.
    - Changed commit message.

Changes in v3:
    - Re-sending the patch.

Changes in v4:
    - Renamed extmode flag to multiproto
    - Fixed typo in description.

 Documentation/networking/bareudp.rst | 20 ++++++++++-
 drivers/net/bareudp.c                | 68 +++++++++++++++++++++++++++++++++---
 include/net/bareudp.h                |  1 +
 include/uapi/linux/if_link.h         |  1 +
 4 files changed, 85 insertions(+), 5 deletions(-)

diff --git a/Documentation/networking/bareudp.rst b/Documentation/networking/bareudp.rst
index 4087a1b..9794dd8 100644
--- a/Documentation/networking/bareudp.rst
+++ b/Documentation/networking/bareudp.rst
@@ -12,6 +12,15 @@ The Bareudp tunnel module provides a generic L3 encapsulation tunnelling
 support for tunnelling different L3 protocols like MPLS, IP, NSH etc. inside
 a UDP tunnel.
 
+Special Handling
+----------------
+The bareudp device supports special handling for MPLS & IP as they can have
+multiple ethertypes.
+MPLS procotcol can have ethertypes ETH_P_MPLS_UC  (unicast) & ETH_P_MPLS_MC (multicast).
+IP protocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6).
+This special handling can be enabled only for ethertypes ETH_P_IP & ETH_P_MPLS_UC
+with a flag called multiproto mode.
+
 Usage
 ------
 
@@ -25,7 +34,16 @@ Usage
 
     b) ip link delete bareudp0
 
-2) Device Usage
+2) Device creation with multiple proto mode enabled
+
+There are two ways to create a bareudp device for MPLS & IP with multiproto mode
+enabled.
+
+    a) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype 0x8847 multiproto
+
+    b) ip link add dev  bareudp0 type bareudp dstport 6635 ethertype mpls
+
+3) Device Usage
 
 The bareudp device could be used along with OVS or flower filter in TC.
 The OVS or TC flower layer must set the tunnel information in SKB dst field before
diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index a0646e2..0ef1949 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c
@@ -45,6 +45,7 @@ struct bareudp_dev {
 	__be16		   ethertype;
 	__be16             port;
 	u16	           sport_min;
+	bool               multi_proto_mode;
 	struct socket      __rcu *sock;
 	struct list_head   next;        /* bareudp node  on namespace list */
 	struct gro_cells   gro_cells;
@@ -73,7 +74,52 @@ static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	else
 		family = AF_INET6;
 
-	proto = bareudp->ethertype;
+	if (bareudp->ethertype == htons(ETH_P_IP)) {
+		struct iphdr *iphdr;
+
+		iphdr = (struct iphdr *)(skb->data + BAREUDP_BASE_HLEN);
+		if (iphdr->version == 4) {
+			proto = bareudp->ethertype;
+		} else if (bareudp->multi_proto_mode && (iphdr->version == 6)) {
+			proto = htons(ETH_P_IPV6);
+		} else {
+			bareudp->dev->stats.rx_dropped++;
+			goto drop;
+		}
+	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
+		struct iphdr *tunnel_hdr;
+
+		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
+		if (tunnel_hdr->version == 4) {
+			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
+				proto = bareudp->ethertype;
+			} else if (bareudp->multi_proto_mode &&
+				   ipv4_is_multicast(tunnel_hdr->daddr)) {
+				proto = htons(ETH_P_MPLS_MC);
+			} else {
+				bareudp->dev->stats.rx_dropped++;
+				goto drop;
+			}
+		} else {
+			int addr_type;
+			struct ipv6hdr *tunnel_hdr_v6;
+
+			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
+			addr_type =
+			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
+			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
+				proto = bareudp->ethertype;
+			} else if (bareudp->multi_proto_mode &&
+				   (addr_type & IPV6_ADDR_MULTICAST)) {
+				proto = htons(ETH_P_MPLS_MC);
+			} else {
+				bareudp->dev->stats.rx_dropped++;
+				goto drop;
+			}
+		}
+	} else {
+		proto = bareudp->ethertype;
+	}
 
 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
 				 proto,
@@ -371,10 +417,13 @@ static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
 	int err;
 
 	if (skb->protocol != bareudp->ethertype) {
-		err = -EINVAL;
-		goto tx_error;
+		if (!bareudp->multi_proto_mode ||
+		    (skb->protocol !=  htons(ETH_P_MPLS_MC) &&
+		     skb->protocol !=  htons(ETH_P_IPV6))) {
+			err = -EINVAL;
+			goto tx_error;
+		}
 	}
-
 	info = skb_tunnel_info(skb);
 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
 		err = -EINVAL;
@@ -470,6 +519,7 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
+	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
 };
 
 /* Info for udev, that this is a virtual tunnel endpoint */
@@ -552,9 +602,15 @@ static int bareudp_configure(struct net *net, struct net_device *dev,
 	if (t)
 		return -EBUSY;
 
+	if (conf->multi_proto_mode &&
+	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
+	     conf->ethertype != htons(ETH_P_IP)))
+		return -EINVAL;
+
 	bareudp->port = conf->port;
 	bareudp->ethertype = conf->ethertype;
 	bareudp->sport_min = conf->sport_min;
+	bareudp->multi_proto_mode = conf->multi_proto_mode;
 	err = register_netdevice(dev);
 	if (err)
 		return err;
@@ -602,6 +658,7 @@ static size_t bareudp_get_size(const struct net_device *dev)
 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
+		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
 		0;
 }
 
@@ -615,6 +672,9 @@ static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		goto nla_put_failure;
 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
 		goto nla_put_failure;
+	if (bareudp->multi_proto_mode &&
+	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
+		goto nla_put_failure;
 
 	return 0;
 
diff --git a/include/net/bareudp.h b/include/net/bareudp.h
index 513fae6..cb03f6f 100644
--- a/include/net/bareudp.h
+++ b/include/net/bareudp.h
@@ -10,6 +10,7 @@ struct bareudp_conf {
 	__be16 ethertype;
 	__be16 port;
 	u16 sport_min;
+	bool multi_proto_mode;
 };
 
 struct net_device *bareudp_dev_create(struct net *net, const char *name,
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index fb4b33a..61e0801 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -596,6 +596,7 @@ enum {
 	IFLA_BAREUDP_PORT,
 	IFLA_BAREUDP_ETHERTYPE,
 	IFLA_BAREUDP_SRCPORT_MIN,
+	IFLA_BAREUDP_MULTIPROTO_MODE,
 	__IFLA_BAREUDP_MAX
 };
 
-- 
1.8.3.1

Re: [PATCH net-next v4 1/2] net: UDP tunnel encapsulation module for

[Willem de Bruijn]

On Tue, Jan 21, 2020 at 12:51 PM Martin Varghese
<martinvarghesenokia@gmail.com> wrote:
>
> From: Martin Varghese <martin.varghese@nokia.com>
>
> The Bareudp tunnel module provides a generic L3 encapsulation
> tunnelling module for tunnelling different protocols like MPLS,
> IP,NSH etc inside a UDP tunnel.
>
> Signed-off-by: Martin Varghese <martin.varghese@nokia.com>

This addresses the main points I raised. A few small points below,
nothing serious. It could use more eye balls, but beyond those Acked
from me.

> ---
> Changes in v2:
>      - Fixed documentation errors.
>      - Converted documentation to rst format.
>      - Moved ip tunnel rt lookup code to a common location.
>      - Removed seperate v4 and v6 socket.
>      - Added call to skb_ensure_writable before updating ethernet header.
>      - Simplified bareudp_destroy_tunnels as deleting devices under a
>        namespace is taken care be the default pernet exit code.
>      - Fixed bareudp_change_mtu.
>
> Changes in v3:
>      - Re-sending the patch again.
>
> Changes in v4:
>      - Converted bareudp device to l3 device.

I didn't quite get this statement, but it encompasses the change to
ARPHRD_NONE and introduction of gro_cells, I guess?

>      - Removed redundant fields in bareudp device.

> diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
> index d07d985..ea3d604 100644
> --- a/Documentation/networking/index.rst
> +++ b/Documentation/networking/index.rst
> @@ -33,6 +33,7 @@ Contents:
>     tls
>     tls-offload
>     nfc
> +   bareudp

if respinning: this list is mostly alphabetically ordened, perhaps
insert before batman-adv

> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index dee7958..9726447 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -258,6 +258,19 @@ config GENEVE
>           To compile this driver as a module, choose M here: the module
>           will be called geneve.
>
> +config BAREUDP
> +       tristate "Bare UDP Encapsulation"
> +       depends on INET && NET_UDP_TUNNEL
> +       depends on IPV6 || !IPV6
> +       select NET_IP_TUNNEL
> +       select GRO_CELLS

Depends on NET_UDP_TUNNEL plus selects NET_IP_TUNNEL seems odd.

NET_UDP_TUNNEL itself selects NET_IP_TUNNEL, so perhaps just select
NET_UDP_TUNNEL.

I had to make that change to be able to get it in a .config after make
defconfig.


> +static int bareudp_change_mtu(struct net_device *dev, int new_mtu)
> +{
> +       dev->mtu = new_mtu;
> +       return 0;
> +}

If your ndo_change_mtu does nothing special, it can just rely on the
assignment in __dev_set_mtu

> +/* Initialize the device structure. */
> +static void bareudp_setup(struct net_device *dev)
> +{
> +       dev->netdev_ops = &bareudp_netdev_ops;
> +       dev->needs_free_netdev = true;
> +       SET_NETDEV_DEVTYPE(dev, &bareudp_type);
> +       dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
> +       dev->features    |= NETIF_F_RXCSUM;
> +       dev->features    |= NETIF_F_GSO_SOFTWARE;
> +       dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
> +       dev->hw_features |= NETIF_F_GSO_SOFTWARE;
> +       dev->hard_header_len = 0;
> +       dev->addr_len = 0;
> +       dev->mtu = 1500;

ETH_DATA_LEN?

Re: [PATCH net-next v4 2/2] net: Special handling for IP & MPLS.

[Willem de Bruijn]

On Tue, Jan 21, 2020 at 12:51 PM Martin Varghese
<martinvarghesenokia@gmail.com> wrote:
>
> From: Martin Varghese <martin.varghese@nokia.com>
>
> Special handling is needed in bareudp module for IP & MPLS as they
> support more than one ethertypes.
>
> MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
> While decapsulating MPLS packet from UDP packet the tunnel destination IP
> address is checked to determine the ethertype. The ethertype of the packet
> will be set to 0x8848 if the  tunnel destination IP address is a multicast
> IP address. The ethertype of the packet will be set to 0x8847 if the
> tunnel destination IP address is a unicast IP address.
>
> IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version
> field of the IP header tunnelled will be checked to determine the ethertype.
>
> This special handling to tunnel additional ethertypes will be disabled
> by default and can be enabled using a flag called ext mode. This flag can
> be used only with ethertypes 0x8847 and 0x0800.
>
> Signed-off-by: Martin Varghese <martin.varghese@nokia.com>

Acked-by: Willem de Bruijn <willemb@google.com>

Re: [PATCH net-next v4 1/2] net: UDP tunnel encapsulation module for

[Martin Varghese]

On Wed, Jan 22, 2020 at 01:29:32PM -0500, Willem de Bruijn wrote:
> On Tue, Jan 21, 2020 at 12:51 PM Martin Varghese
> <martinvarghesenokia@gmail.com> wrote:
> >
> > From: Martin Varghese <martin.varghese@nokia.com>
> >
> > The Bareudp tunnel module provides a generic L3 encapsulation
> > tunnelling module for tunnelling different protocols like MPLS,
> > IP,NSH etc inside a UDP tunnel.
> >
> > Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
> 
> This addresses the main points I raised. A few small points below,
> nothing serious. It could use more eye balls, but beyond those Acked
> from me.
> 
> > ---
> > Changes in v2:
> >      - Fixed documentation errors.
> >      - Converted documentation to rst format.
> >      - Moved ip tunnel rt lookup code to a common location.
> >      - Removed seperate v4 and v6 socket.
> >      - Added call to skb_ensure_writable before updating ethernet header.
> >      - Simplified bareudp_destroy_tunnels as deleting devices under a
> >        namespace is taken care be the default pernet exit code.
> >      - Fixed bareudp_change_mtu.
> >
> > Changes in v3:
> >      - Re-sending the patch again.
> >
> > Changes in v4:
> >      - Converted bareudp device to l3 device.
> 
> I didn't quite get this statement, but it encompasses the change to
> ARPHRD_NONE and introduction of gro_cells, I guess?
>
The term l3 device is from OVS may be.What i meant is we no longer
needed the dummy ethernet header and the device works with l3 packet.
 
> >      - Removed redundant fields in bareudp device.
> 
> > diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
> > index d07d985..ea3d604 100644
> > --- a/Documentation/networking/index.rst
> > +++ b/Documentation/networking/index.rst
> > @@ -33,6 +33,7 @@ Contents:
> >     tls
> >     tls-offload
> >     nfc
> > +   bareudp
> 
> if respinning: this list is mostly alphabetically ordened, perhaps
> insert before batman-adv
> 
> > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> > index dee7958..9726447 100644
> > --- a/drivers/net/Kconfig
> > +++ b/drivers/net/Kconfig
> > @@ -258,6 +258,19 @@ config GENEVE
> >           To compile this driver as a module, choose M here: the module
> >           will be called geneve.
> >
> > +config BAREUDP
> > +       tristate "Bare UDP Encapsulation"
> > +       depends on INET && NET_UDP_TUNNEL
> > +       depends on IPV6 || !IPV6
> > +       select NET_IP_TUNNEL
> > +       select GRO_CELLS
> 
> Depends on NET_UDP_TUNNEL plus selects NET_IP_TUNNEL seems odd.
> 
> NET_UDP_TUNNEL itself selects NET_IP_TUNNEL, so perhaps just select
> NET_UDP_TUNNEL.
> 
> I had to make that change to be able to get it in a .config after make
> defconfig.
> 
> 
Noted
> > +static int bareudp_change_mtu(struct net_device *dev, int new_mtu)
> > +{
> > +       dev->mtu = new_mtu;
> > +       return 0;
> > +}
> 
> If your ndo_change_mtu does nothing special, it can just rely on the
> assignment in __dev_set_mtu
> 
Yes we could remove the ndo_change_mtu implementation as it is redundant
But i would like to retain bareudp_change_mtu and also to add a validation 
code in the function as no validation is done in the rtnetlink layer during newlink create

> > +/* Initialize the device structure. */
> > +static void bareudp_setup(struct net_device *dev)
> > +{
> > +       dev->netdev_ops = &bareudp_netdev_ops;
> > +       dev->needs_free_netdev = true;
> > +       SET_NETDEV_DEVTYPE(dev, &bareudp_type);
> > +       dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
> > +       dev->features    |= NETIF_F_RXCSUM;
> > +       dev->features    |= NETIF_F_GSO_SOFTWARE;
> > +       dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
> > +       dev->hw_features |= NETIF_F_GSO_SOFTWARE;
> > +       dev->hard_header_len = 0;
> > +       dev->addr_len = 0;
> > +       dev->mtu = 1500;
> 
> ETH_DATA_LEN?
Noted

Thanks for your time.The code look really better from the v1 version.

Re: [PATCH net-next v4 2/2] net: Special handling for IP & MPLS.

[Martin Varghese]

On Wed, Jan 22, 2020 at 01:30:53PM -0500, Willem de Bruijn wrote:
> On Tue, Jan 21, 2020 at 12:51 PM Martin Varghese
> <martinvarghesenokia@gmail.com> wrote:
> >
> > From: Martin Varghese <martin.varghese@nokia.com>
> >
> > Special handling is needed in bareudp module for IP & MPLS as they
> > support more than one ethertypes.
> >
> > MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
> > While decapsulating MPLS packet from UDP packet the tunnel destination IP
> > address is checked to determine the ethertype. The ethertype of the packet
> > will be set to 0x8848 if the  tunnel destination IP address is a multicast
> > IP address. The ethertype of the packet will be set to 0x8847 if the
> > tunnel destination IP address is a unicast IP address.
> >
> > IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version
> > field of the IP header tunnelled will be checked to determine the ethertype.
> >
> > This special handling to tunnel additional ethertypes will be disabled
> > by default and can be enabled using a flag called ext mode. This flag can
> > be used only with ethertypes 0x8847 and 0x0800.
> >
> > Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
> 
> Acked-by: Willem de Bruijn <willemb@google.com>

Thanks for your time.

Re: [PATCH net-next v4 1/2] net: UDP tunnel encapsulation module for

[Martin Varghese]

On Wed, Jan 22, 2020 at 01:29:32PM -0500, Willem de Bruijn wrote:
> On Tue, Jan 21, 2020 at 12:51 PM Martin Varghese
> <martinvarghesenokia@gmail.com> wrote:
> >
> > From: Martin Varghese <martin.varghese@nokia.com>
> >
> > The Bareudp tunnel module provides a generic L3 encapsulation
> > tunnelling module for tunnelling different protocols like MPLS,
> > IP,NSH etc inside a UDP tunnel.
> >
> > Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
> 
> This addresses the main points I raised. A few small points below,
> nothing serious. It could use more eye balls, but beyond those Acked
> from me.
> 
> > ---
> > Changes in v2:
> >      - Fixed documentation errors.
> >      - Converted documentation to rst format.
> >      - Moved ip tunnel rt lookup code to a common location.
> >      - Removed seperate v4 and v6 socket.
> >      - Added call to skb_ensure_writable before updating ethernet header.
> >      - Simplified bareudp_destroy_tunnels as deleting devices under a
> >        namespace is taken care be the default pernet exit code.
> >      - Fixed bareudp_change_mtu.
> >
> > Changes in v3:
> >      - Re-sending the patch again.
> >
> > Changes in v4:
> >      - Converted bareudp device to l3 device.
> 
> I didn't quite get this statement, but it encompasses the change to
> ARPHRD_NONE and introduction of gro_cells, I guess?
> 
> >      - Removed redundant fields in bareudp device.
> 
> > diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
> > index d07d985..ea3d604 100644
> > --- a/Documentation/networking/index.rst
> > +++ b/Documentation/networking/index.rst
> > @@ -33,6 +33,7 @@ Contents:
> >     tls
> >     tls-offload
> >     nfc
> > +   bareudp
> 
> if respinning: this list is mostly alphabetically ordened, perhaps
> insert before batman-adv
> 
> > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> > index dee7958..9726447 100644
> > --- a/drivers/net/Kconfig
> > +++ b/drivers/net/Kconfig
> > @@ -258,6 +258,19 @@ config GENEVE
> >           To compile this driver as a module, choose M here: the module
> >           will be called geneve.
> >
> > +config BAREUDP
> > +       tristate "Bare UDP Encapsulation"
> > +       depends on INET && NET_UDP_TUNNEL
> > +       depends on IPV6 || !IPV6
> > +       select NET_IP_TUNNEL
> > +       select GRO_CELLS
> 
> Depends on NET_UDP_TUNNEL plus selects NET_IP_TUNNEL seems odd.
> 
> NET_UDP_TUNNEL itself selects NET_IP_TUNNEL, so perhaps just select
> NET_UDP_TUNNEL.
> 
> I had to make that change to be able to get it in a .config after make
> defconfig.
> 
> 
> > +static int bareudp_change_mtu(struct net_device *dev, int new_mtu)
> > +{
> > +       dev->mtu = new_mtu;
> > +       return 0;
> > +}
> 
> If your ndo_change_mtu does nothing special, it can just rely on the
> assignment in __dev_set_mtu
>
yes.
we could  set dev_set_mtu in all the cases.ignore my previous reply
> > +/* Initialize the device structure. */
> > +static void bareudp_setup(struct net_device *dev)
> > +{
> > +       dev->netdev_ops = &bareudp_netdev_ops;
> > +       dev->needs_free_netdev = true;
> > +       SET_NETDEV_DEVTYPE(dev, &bareudp_type);
> > +       dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
> > +       dev->features    |= NETIF_F_RXCSUM;
> > +       dev->features    |= NETIF_F_GSO_SOFTWARE;
> > +       dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
> > +       dev->hw_features |= NETIF_F_GSO_SOFTWARE;
> > +       dev->hard_header_len = 0;
> > +       dev->addr_len = 0;
> > +       dev->mtu = 1500;
> 
> ETH_DATA_LEN?

Re: [PATCH net-next v4 1/2] net: UDP tunnel encapsulation module for

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 3116 bytes --]

Hi Martin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]
[also build test WARNING on net/master linus/master v5.5-rc7 next-20200123]
[cannot apply to ipvs/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Martin-Varghese/Bare-UDP-L3-Encapsulation-Module/20200124-103044
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 9bbc8be29d66cc34b650510f2c67b5c55235fe5d
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 7.5.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=sh 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers//net/bareudp.c: In function 'bareudp_fill_metadata_dst':
>> drivers//net/bareudp.c:455:9: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret;
            ^~~

vim +/ret +455 drivers//net/bareudp.c

   413	
   414	static int bareudp_fill_metadata_dst(struct net_device *dev,
   415					     struct sk_buff *skb)
   416	{
   417		struct ip_tunnel_info *info = skb_tunnel_info(skb);
   418		struct bareudp_dev *bareudp = netdev_priv(dev);
   419		bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
   420		int ret;
   421	
   422		if (ip_tunnel_info_af(info) == AF_INET) {
   423			struct rtable *rt;
   424			struct flowi4 fl4;
   425	
   426			rt = iptunnel_get_rt(skb, dev, bareudp->net, &fl4, info,
   427					     use_cache);
   428			if (IS_ERR(rt))
   429				return PTR_ERR(rt);
   430	
   431			ip_rt_put(rt);
   432			info->key.u.ipv4.src = fl4.saddr;
   433	#if IS_ENABLED(CONFIG_IPV6)
   434		} else if (ip_tunnel_info_af(info) == AF_INET6) {
   435			struct dst_entry *dst;
   436			struct flowi6 fl6;
   437			struct socket *sock = rcu_dereference(bareudp->sock);
   438	
   439			dst = ip6tunnel_get_dst(skb, dev, bareudp->net, sock, &fl6,
   440						info, use_cache);
   441			if (IS_ERR(dst))
   442				return PTR_ERR(dst);
   443	
   444			dst_release(dst);
   445			info->key.u.ipv6.src = fl6.saddr;
   446	#endif
   447		} else {
   448			return -EINVAL;
   449		}
   450	
   451		info->key.tp_src = udp_flow_src_port(bareudp->net, skb,
   452						     bareudp->sport_min,
   453				USHRT_MAX, true);
   454		info->key.tp_dst = bareudp->port;
 > 455		return ret;
   456	}
   457	

---
0-DAY kernel test infrastructure                 Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 52846 bytes --]

Re: [PATCH net-next v4 1/2] net: UDP tunnel encapsulation module for

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 3993 bytes --]

Hi Martin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]
[also build test WARNING on net/master linus/master v5.5-rc7 next-20200122]
[cannot apply to ipvs/master]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Martin-Varghese/Bare-UDP-L3-Encapsulation-Module/20200124-103044
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 9bbc8be29d66cc34b650510f2c67b5c55235fe5d
config: openrisc-randconfig-a001-20200124 (attached as .config)
compiler: or1k-linux-gcc (GCC) 9.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=9.2.0 make.cross ARCH=openrisc 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from net/ipv4/ip_tunnel_core.c:27:
   include/net/ip6_tunnel.h: In function 'ip6tunnel_get_dst':
   include/net/ip6_tunnel.h:195:9: error: implicit declaration of function 'dst_cache_get_ip6'; did you mean 'dst_cache_get_ip4'? [-Werror=implicit-function-declaration]
     195 |   dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
         |         ^~~~~~~~~~~~~~~~~
         |         dst_cache_get_ip4
>> include/net/ip6_tunnel.h:195:7: warning: assignment to 'struct dst_entry *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     195 |   dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
         |       ^
   include/net/ip6_tunnel.h:213:3: error: implicit declaration of function 'dst_cache_set_ip6'; did you mean 'dst_cache_set_ip4'? [-Werror=implicit-function-declaration]
     213 |   dst_cache_set_ip6(dst_cache, dst, &fl6->saddr);
         |   ^~~~~~~~~~~~~~~~~
         |   dst_cache_set_ip4
   cc1: some warnings being treated as errors

vim +195 include/net/ip6_tunnel.h

   168	
   169	static inline struct dst_entry *ip6tunnel_get_dst(struct sk_buff *skb,
   170							  struct net_device *dev,
   171							  struct net *net,
   172							  struct socket *sock,
   173							  struct flowi6 *fl6,
   174							  const struct ip_tunnel_info *info,
   175							  bool use_cache)
   176	{
   177		struct dst_entry *dst = NULL;
   178	#ifdef CONFIG_DST_CACHE
   179		struct dst_cache *dst_cache;
   180	#endif
   181		__u8 prio;
   182	
   183		memset(fl6, 0, sizeof(*fl6));
   184		fl6->flowi6_mark = skb->mark;
   185		fl6->flowi6_proto = IPPROTO_UDP;
   186		fl6->daddr = info->key.u.ipv6.dst;
   187		fl6->saddr = info->key.u.ipv6.src;
   188		prio = info->key.tos;
   189	
   190		fl6->flowlabel = ip6_make_flowinfo(RT_TOS(prio),
   191						   info->key.label);
   192	#ifdef CONFIG_DST_CACHE
   193		dst_cache = (struct dst_cache *)&info->dst_cache;
   194		if (use_cache) {
 > 195			dst = dst_cache_get_ip6(dst_cache, &fl6->saddr);
   196			if (dst)
   197				return dst;
   198		}
   199	#endif
   200		dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, fl6,
   201						      NULL);
   202		if (IS_ERR(dst)) {
   203			netdev_dbg(dev, "no route to %pI6\n", &fl6->daddr);
   204			return ERR_PTR(-ENETUNREACH);
   205		}
   206		if (dst->dev == dev) { /* is this necessary? */
   207			netdev_dbg(dev, "circular route to %pI6\n", &fl6->daddr);
   208			dst_release(dst);
   209			return ERR_PTR(-ELOOP);
   210		}
   211	#ifdef CONFIG_DST_CACHE
   212		if (use_cache)
   213			dst_cache_set_ip6(dst_cache, dst, &fl6->saddr);
   214	#endif
   215		return dst;
   216	}
   217	

---
0-DAY kernel test infrastructure                 Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation

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