Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 973 insertions, 0 deletions

diff --git a/net/ipv4/udp_tunnel_nic.c b/net/ipv4/udp_tunnel_nic.c
new file mode 100644
index 000000000..bc3a043a5
--- /dev/null
+++ b/net/ipv4/udp_tunnel_nic.c
@@ -0,0 +1,973 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2020 Facebook Inc.
+
+#include <linux/ethtool_netlink.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <net/udp_tunnel.h>
+#include <net/vxlan.h>
+
+enum udp_tunnel_nic_table_entry_flags {
+	UDP_TUNNEL_NIC_ENTRY_ADD	= BIT(0),
+	UDP_TUNNEL_NIC_ENTRY_DEL	= BIT(1),
+	UDP_TUNNEL_NIC_ENTRY_OP_FAIL	= BIT(2),
+	UDP_TUNNEL_NIC_ENTRY_FROZEN	= BIT(3),
+};
+
+struct udp_tunnel_nic_table_entry {
+	__be16 port;
+	u8 type;
+	u8 flags;
+	u16 use_cnt;
+#define UDP_TUNNEL_NIC_USE_CNT_MAX	U16_MAX
+	u8 hw_priv;
+};
+
+/**
+ * struct udp_tunnel_nic - UDP tunnel port offload state
+ * @work:	async work for talking to hardware from process context
+ * @dev:	netdev pointer
+ * @need_sync:	at least one port start changed
+ * @need_replay: space was freed, we need a replay of all ports
+ * @work_pending: @work is currently scheduled
+ * @n_tables:	number of tables under @entries
+ * @missed:	bitmap of tables which overflown
+ * @entries:	table of tables of ports currently offloaded
+ */
+struct udp_tunnel_nic {
+	struct work_struct work;
+
+	struct net_device *dev;
+
+	u8 need_sync:1;
+	u8 need_replay:1;
+	u8 work_pending:1;
+
+	unsigned int n_tables;
+	unsigned long missed;
+	struct udp_tunnel_nic_table_entry **entries;
+};
+
+/* We ensure all work structs are done using driver state, but not the code.
+ * We need a workqueue we can flush before module gets removed.
+ */
+static struct workqueue_struct *udp_tunnel_nic_workqueue;
+
+static const char *udp_tunnel_nic_tunnel_type_name(unsigned int type)
+{
+	switch (type) {
+	case UDP_TUNNEL_TYPE_VXLAN:
+		return "vxlan";
+	case UDP_TUNNEL_TYPE_GENEVE:
+		return "geneve";
+	case UDP_TUNNEL_TYPE_VXLAN_GPE:
+		return "vxlan-gpe";
+	default:
+		return "unknown";
+	}
+}
+
+static bool
+udp_tunnel_nic_entry_is_free(struct udp_tunnel_nic_table_entry *entry)
+{
+	return entry->use_cnt == 0 && !entry->flags;
+}
+
+static bool
+udp_tunnel_nic_entry_is_present(struct udp_tunnel_nic_table_entry *entry)
+{
+	return entry->use_cnt && !(entry->flags & ~UDP_TUNNEL_NIC_ENTRY_FROZEN);
+}
+
+static bool
+udp_tunnel_nic_entry_is_frozen(struct udp_tunnel_nic_table_entry *entry)
+{
+	return entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN;
+}
+
+static void
+udp_tunnel_nic_entry_freeze_used(struct udp_tunnel_nic_table_entry *entry)
+{
+	if (!udp_tunnel_nic_entry_is_free(entry))
+		entry->flags |= UDP_TUNNEL_NIC_ENTRY_FROZEN;
+}
+
+static void
+udp_tunnel_nic_entry_unfreeze(struct udp_tunnel_nic_table_entry *entry)
+{
+	entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_FROZEN;
+}
+
+static bool
+udp_tunnel_nic_entry_is_queued(struct udp_tunnel_nic_table_entry *entry)
+{
+	return entry->flags & (UDP_TUNNEL_NIC_ENTRY_ADD |
+			       UDP_TUNNEL_NIC_ENTRY_DEL);
+}
+
+static void
+udp_tunnel_nic_entry_queue(struct udp_tunnel_nic *utn,
+			   struct udp_tunnel_nic_table_entry *entry,
+			   unsigned int flag)
+{
+	entry->flags |= flag;
+	utn->need_sync = 1;
+}
+
+static void
+udp_tunnel_nic_ti_from_entry(struct udp_tunnel_nic_table_entry *entry,
+			     struct udp_tunnel_info *ti)
+{
+	memset(ti, 0, sizeof(*ti));
+	ti->port = entry->port;
+	ti->type = entry->type;
+	ti->hw_priv = entry->hw_priv;
+}
+
+static bool
+udp_tunnel_nic_is_empty(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	unsigned int i, j;
+
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++)
+			if (!udp_tunnel_nic_entry_is_free(&utn->entries[i][j]))
+				return false;
+	return true;
+}
+
+static bool
+udp_tunnel_nic_should_replay(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_table_info *table;
+	unsigned int i, j;
+
+	if (!utn->missed)
+		return false;
+
+	for (i = 0; i < utn->n_tables; i++) {
+		table = &dev->udp_tunnel_nic_info->tables[i];
+		if (!test_bit(i, &utn->missed))
+			continue;
+
+		for (j = 0; j < table->n_entries; j++)
+			if (udp_tunnel_nic_entry_is_free(&utn->entries[i][j]))
+				return true;
+	}
+
+	return false;
+}
+
+static void
+__udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
+			  unsigned int idx, struct udp_tunnel_info *ti)
+{
+	struct udp_tunnel_nic_table_entry *entry;
+	struct udp_tunnel_nic *utn;
+
+	utn = dev->udp_tunnel_nic;
+	entry = &utn->entries[table][idx];
+
+	if (entry->use_cnt)
+		udp_tunnel_nic_ti_from_entry(entry, ti);
+}
+
+static void
+__udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
+			       unsigned int idx, u8 priv)
+{
+	dev->udp_tunnel_nic->entries[table][idx].hw_priv = priv;
+}
+
+static void
+udp_tunnel_nic_entry_update_done(struct udp_tunnel_nic_table_entry *entry,
+				 int err)
+{
+	bool dodgy = entry->flags & UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
+
+	WARN_ON_ONCE(entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD &&
+		     entry->flags & UDP_TUNNEL_NIC_ENTRY_DEL);
+
+	if (entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD &&
+	    (!err || (err == -EEXIST && dodgy)))
+		entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_ADD;
+
+	if (entry->flags & UDP_TUNNEL_NIC_ENTRY_DEL &&
+	    (!err || (err == -ENOENT && dodgy)))
+		entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_DEL;
+
+	if (!err)
+		entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
+	else
+		entry->flags |= UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
+}
+
+static void
+udp_tunnel_nic_device_sync_one(struct net_device *dev,
+			       struct udp_tunnel_nic *utn,
+			       unsigned int table, unsigned int idx)
+{
+	struct udp_tunnel_nic_table_entry *entry;
+	struct udp_tunnel_info ti;
+	int err;
+
+	entry = &utn->entries[table][idx];
+	if (!udp_tunnel_nic_entry_is_queued(entry))
+		return;
+
+	udp_tunnel_nic_ti_from_entry(entry, &ti);
+	if (entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD)
+		err = dev->udp_tunnel_nic_info->set_port(dev, table, idx, &ti);
+	else
+		err = dev->udp_tunnel_nic_info->unset_port(dev, table, idx,
+							   &ti);
+	udp_tunnel_nic_entry_update_done(entry, err);
+
+	if (err)
+		netdev_warn(dev,
+			    "UDP tunnel port sync failed port %d type %s: %d\n",
+			    be16_to_cpu(entry->port),
+			    udp_tunnel_nic_tunnel_type_name(entry->type),
+			    err);
+}
+
+static void
+udp_tunnel_nic_device_sync_by_port(struct net_device *dev,
+				   struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	unsigned int i, j;
+
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++)
+			udp_tunnel_nic_device_sync_one(dev, utn, i, j);
+}
+
+static void
+udp_tunnel_nic_device_sync_by_table(struct net_device *dev,
+				    struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	unsigned int i, j;
+	int err;
+
+	for (i = 0; i < utn->n_tables; i++) {
+		/* Find something that needs sync in this table */
+		for (j = 0; j < info->tables[i].n_entries; j++)
+			if (udp_tunnel_nic_entry_is_queued(&utn->entries[i][j]))
+				break;
+		if (j == info->tables[i].n_entries)
+			continue;
+
+		err = info->sync_table(dev, i);
+		if (err)
+			netdev_warn(dev, "UDP tunnel port sync failed for table %d: %d\n",
+				    i, err);
+
+		for (j = 0; j < info->tables[i].n_entries; j++) {
+			struct udp_tunnel_nic_table_entry *entry;
+
+			entry = &utn->entries[i][j];
+			if (udp_tunnel_nic_entry_is_queued(entry))
+				udp_tunnel_nic_entry_update_done(entry, err);
+		}
+	}
+}
+
+static void
+__udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	if (!utn->need_sync)
+		return;
+
+	if (dev->udp_tunnel_nic_info->sync_table)
+		udp_tunnel_nic_device_sync_by_table(dev, utn);
+	else
+		udp_tunnel_nic_device_sync_by_port(dev, utn);
+
+	utn->need_sync = 0;
+	/* Can't replay directly here, in case we come from the tunnel driver's
+	 * notification - trying to replay may deadlock inside tunnel driver.
+	 */
+	utn->need_replay = udp_tunnel_nic_should_replay(dev, utn);
+}
+
+static void
+udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	bool may_sleep;
+
+	if (!utn->need_sync)
+		return;
+
+	/* Drivers which sleep in the callback need to update from
+	 * the workqueue, if we come from the tunnel driver's notification.
+	 */
+	may_sleep = info->flags & UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
+	if (!may_sleep)
+		__udp_tunnel_nic_device_sync(dev, utn);
+	if (may_sleep || utn->need_replay) {
+		queue_work(udp_tunnel_nic_workqueue, &utn->work);
+		utn->work_pending = 1;
+	}
+}
+
+static bool
+udp_tunnel_nic_table_is_capable(const struct udp_tunnel_nic_table_info *table,
+				struct udp_tunnel_info *ti)
+{
+	return table->tunnel_types & ti->type;
+}
+
+static bool
+udp_tunnel_nic_is_capable(struct net_device *dev, struct udp_tunnel_nic *utn,
+			  struct udp_tunnel_info *ti)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	unsigned int i;
+
+	/* Special case IPv4-only NICs */
+	if (info->flags & UDP_TUNNEL_NIC_INFO_IPV4_ONLY &&
+	    ti->sa_family != AF_INET)
+		return false;
+
+	for (i = 0; i < utn->n_tables; i++)
+		if (udp_tunnel_nic_table_is_capable(&info->tables[i], ti))
+			return true;
+	return false;
+}
+
+static int
+udp_tunnel_nic_has_collision(struct net_device *dev, struct udp_tunnel_nic *utn,
+			     struct udp_tunnel_info *ti)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic_table_entry *entry;
+	unsigned int i, j;
+
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++) {
+			entry =	&utn->entries[i][j];
+
+			if (!udp_tunnel_nic_entry_is_free(entry) &&
+			    entry->port == ti->port &&
+			    entry->type != ti->type) {
+				__set_bit(i, &utn->missed);
+				return true;
+			}
+		}
+	return false;
+}
+
+static void
+udp_tunnel_nic_entry_adj(struct udp_tunnel_nic *utn,
+			 unsigned int table, unsigned int idx, int use_cnt_adj)
+{
+	struct udp_tunnel_nic_table_entry *entry =  &utn->entries[table][idx];
+	bool dodgy = entry->flags & UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
+	unsigned int from, to;
+
+	WARN_ON(entry->use_cnt + (u32)use_cnt_adj > U16_MAX);
+
+	/* If not going from used to unused or vice versa - all done.
+	 * For dodgy entries make sure we try to sync again (queue the entry).
+	 */
+	entry->use_cnt += use_cnt_adj;
+	if (!dodgy && !entry->use_cnt == !(entry->use_cnt - use_cnt_adj))
+		return;
+
+	/* Cancel the op before it was sent to the device, if possible,
+	 * otherwise we'd need to take special care to issue commands
+	 * in the same order the ports arrived.
+	 */
+	if (use_cnt_adj < 0) {
+		from = UDP_TUNNEL_NIC_ENTRY_ADD;
+		to = UDP_TUNNEL_NIC_ENTRY_DEL;
+	} else {
+		from = UDP_TUNNEL_NIC_ENTRY_DEL;
+		to = UDP_TUNNEL_NIC_ENTRY_ADD;
+	}
+
+	if (entry->flags & from) {
+		entry->flags &= ~from;
+		if (!dodgy)
+			return;
+	}
+
+	udp_tunnel_nic_entry_queue(utn, entry, to);
+}
+
+static bool
+udp_tunnel_nic_entry_try_adj(struct udp_tunnel_nic *utn,
+			     unsigned int table, unsigned int idx,
+			     struct udp_tunnel_info *ti, int use_cnt_adj)
+{
+	struct udp_tunnel_nic_table_entry *entry =  &utn->entries[table][idx];
+
+	if (udp_tunnel_nic_entry_is_free(entry) ||
+	    entry->port != ti->port ||
+	    entry->type != ti->type)
+		return false;
+
+	if (udp_tunnel_nic_entry_is_frozen(entry))
+		return true;
+
+	udp_tunnel_nic_entry_adj(utn, table, idx, use_cnt_adj);
+	return true;
+}
+
+/* Try to find existing matching entry and adjust its use count, instead of
+ * adding a new one. Returns true if entry was found. In case of delete the
+ * entry may have gotten removed in the process, in which case it will be
+ * queued for removal.
+ */
+static bool
+udp_tunnel_nic_try_existing(struct net_device *dev, struct udp_tunnel_nic *utn,
+			    struct udp_tunnel_info *ti, int use_cnt_adj)
+{
+	const struct udp_tunnel_nic_table_info *table;
+	unsigned int i, j;
+
+	for (i = 0; i < utn->n_tables; i++) {
+		table = &dev->udp_tunnel_nic_info->tables[i];
+		if (!udp_tunnel_nic_table_is_capable(table, ti))
+			continue;
+
+		for (j = 0; j < table->n_entries; j++)
+			if (udp_tunnel_nic_entry_try_adj(utn, i, j, ti,
+							 use_cnt_adj))
+				return true;
+	}
+
+	return false;
+}
+
+static bool
+udp_tunnel_nic_add_existing(struct net_device *dev, struct udp_tunnel_nic *utn,
+			    struct udp_tunnel_info *ti)
+{
+	return udp_tunnel_nic_try_existing(dev, utn, ti, +1);
+}
+
+static bool
+udp_tunnel_nic_del_existing(struct net_device *dev, struct udp_tunnel_nic *utn,
+			    struct udp_tunnel_info *ti)
+{
+	return udp_tunnel_nic_try_existing(dev, utn, ti, -1);
+}
+
+static bool
+udp_tunnel_nic_add_new(struct net_device *dev, struct udp_tunnel_nic *utn,
+		       struct udp_tunnel_info *ti)
+{
+	const struct udp_tunnel_nic_table_info *table;
+	unsigned int i, j;
+
+	for (i = 0; i < utn->n_tables; i++) {
+		table = &dev->udp_tunnel_nic_info->tables[i];
+		if (!udp_tunnel_nic_table_is_capable(table, ti))
+			continue;
+
+		for (j = 0; j < table->n_entries; j++) {
+			struct udp_tunnel_nic_table_entry *entry;
+
+			entry = &utn->entries[i][j];
+			if (!udp_tunnel_nic_entry_is_free(entry))
+				continue;
+
+			entry->port = ti->port;
+			entry->type = ti->type;
+			entry->use_cnt = 1;
+			udp_tunnel_nic_entry_queue(utn, entry,
+						   UDP_TUNNEL_NIC_ENTRY_ADD);
+			return true;
+		}
+
+		/* The different table may still fit this port in, but there
+		 * are no devices currently which have multiple tables accepting
+		 * the same tunnel type, and false positives are okay.
+		 */
+		__set_bit(i, &utn->missed);
+	}
+
+	return false;
+}
+
+static void
+__udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic *utn;
+
+	utn = dev->udp_tunnel_nic;
+	if (!utn)
+		return;
+	if (!netif_running(dev) && info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY)
+		return;
+	if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN &&
+	    ti->port == htons(IANA_VXLAN_UDP_PORT)) {
+		if (ti->type != UDP_TUNNEL_TYPE_VXLAN)
+			netdev_warn(dev, "device assumes port 4789 will be used by vxlan tunnels\n");
+		return;
+	}
+
+	if (!udp_tunnel_nic_is_capable(dev, utn, ti))
+		return;
+
+	/* It may happen that a tunnel of one type is removed and different
+	 * tunnel type tries to reuse its port before the device was informed.
+	 * Rely on utn->missed to re-add this port later.
+	 */
+	if (udp_tunnel_nic_has_collision(dev, utn, ti))
+		return;
+
+	if (!udp_tunnel_nic_add_existing(dev, utn, ti))
+		udp_tunnel_nic_add_new(dev, utn, ti);
+
+	udp_tunnel_nic_device_sync(dev, utn);
+}
+
+static void
+__udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
+{
+	struct udp_tunnel_nic *utn;
+
+	utn = dev->udp_tunnel_nic;
+	if (!utn)
+		return;
+
+	if (!udp_tunnel_nic_is_capable(dev, utn, ti))
+		return;
+
+	udp_tunnel_nic_del_existing(dev, utn, ti);
+
+	udp_tunnel_nic_device_sync(dev, utn);
+}
+
+static void __udp_tunnel_nic_reset_ntf(struct net_device *dev)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic *utn;
+	unsigned int i, j;
+
+	ASSERT_RTNL();
+
+	utn = dev->udp_tunnel_nic;
+	if (!utn)
+		return;
+
+	utn->need_sync = false;
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++) {
+			struct udp_tunnel_nic_table_entry *entry;
+
+			entry = &utn->entries[i][j];
+
+			entry->flags &= ~(UDP_TUNNEL_NIC_ENTRY_DEL |
+					  UDP_TUNNEL_NIC_ENTRY_OP_FAIL);
+			/* We don't release rtnl across ops */
+			WARN_ON(entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN);
+			if (!entry->use_cnt)
+				continue;
+
+			udp_tunnel_nic_entry_queue(utn, entry,
+						   UDP_TUNNEL_NIC_ENTRY_ADD);
+		}
+
+	__udp_tunnel_nic_device_sync(dev, utn);
+}
+
+static size_t
+__udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic *utn;
+	unsigned int j;
+	size_t size;
+
+	utn = dev->udp_tunnel_nic;
+	if (!utn)
+		return 0;
+
+	size = 0;
+	for (j = 0; j < info->tables[table].n_entries; j++) {
+		if (!udp_tunnel_nic_entry_is_present(&utn->entries[table][j]))
+			continue;
+
+		size += nla_total_size(0) +		 /* _TABLE_ENTRY */
+			nla_total_size(sizeof(__be16)) + /* _ENTRY_PORT */
+			nla_total_size(sizeof(u32));	 /* _ENTRY_TYPE */
+	}
+
+	return size;
+}
+
+static int
+__udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
+			    struct sk_buff *skb)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic *utn;
+	struct nlattr *nest;
+	unsigned int j;
+
+	utn = dev->udp_tunnel_nic;
+	if (!utn)
+		return 0;
+
+	for (j = 0; j < info->tables[table].n_entries; j++) {
+		if (!udp_tunnel_nic_entry_is_present(&utn->entries[table][j]))
+			continue;
+
+		nest = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY);
+
+		if (nla_put_be16(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT,
+				 utn->entries[table][j].port) ||
+		    nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE,
+				ilog2(utn->entries[table][j].type)))
+			goto err_cancel;
+
+		nla_nest_end(skb, nest);
+	}
+
+	return 0;
+
+err_cancel:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
+static const struct udp_tunnel_nic_ops __udp_tunnel_nic_ops = {
+	.get_port	= __udp_tunnel_nic_get_port,
+	.set_port_priv	= __udp_tunnel_nic_set_port_priv,
+	.add_port	= __udp_tunnel_nic_add_port,
+	.del_port	= __udp_tunnel_nic_del_port,
+	.reset_ntf	= __udp_tunnel_nic_reset_ntf,
+	.dump_size	= __udp_tunnel_nic_dump_size,
+	.dump_write	= __udp_tunnel_nic_dump_write,
+};
+
+static void
+udp_tunnel_nic_flush(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	unsigned int i, j;
+
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++) {
+			int adj_cnt = -utn->entries[i][j].use_cnt;
+
+			if (adj_cnt)
+				udp_tunnel_nic_entry_adj(utn, i, j, adj_cnt);
+		}
+
+	__udp_tunnel_nic_device_sync(dev, utn);
+
+	for (i = 0; i < utn->n_tables; i++)
+		memset(utn->entries[i], 0, array_size(info->tables[i].n_entries,
+						      sizeof(**utn->entries)));
+	WARN_ON(utn->need_sync);
+	utn->need_replay = 0;
+}
+
+static void
+udp_tunnel_nic_replay(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic_shared_node *node;
+	unsigned int i, j;
+
+	/* Freeze all the ports we are already tracking so that the replay
+	 * does not double up the refcount.
+	 */
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++)
+			udp_tunnel_nic_entry_freeze_used(&utn->entries[i][j]);
+	utn->missed = 0;
+	utn->need_replay = 0;
+
+	if (!info->shared) {
+		udp_tunnel_get_rx_info(dev);
+	} else {
+		list_for_each_entry(node, &info->shared->devices, list)
+			udp_tunnel_get_rx_info(node->dev);
+	}
+
+	for (i = 0; i < utn->n_tables; i++)
+		for (j = 0; j < info->tables[i].n_entries; j++)
+			udp_tunnel_nic_entry_unfreeze(&utn->entries[i][j]);
+}
+
+static void udp_tunnel_nic_device_sync_work(struct work_struct *work)
+{
+	struct udp_tunnel_nic *utn =
+		container_of(work, struct udp_tunnel_nic, work);
+
+	rtnl_lock();
+	utn->work_pending = 0;
+	__udp_tunnel_nic_device_sync(utn->dev, utn);
+
+	if (utn->need_replay)
+		udp_tunnel_nic_replay(utn->dev, utn);
+	rtnl_unlock();
+}
+
+static struct udp_tunnel_nic *
+udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info,
+		     unsigned int n_tables)
+{
+	struct udp_tunnel_nic *utn;
+	unsigned int i;
+
+	utn = kzalloc(sizeof(*utn), GFP_KERNEL);
+	if (!utn)
+		return NULL;
+	utn->n_tables = n_tables;
+	INIT_WORK(&utn->work, udp_tunnel_nic_device_sync_work);
+
+	utn->entries = kmalloc_array(n_tables, sizeof(void *), GFP_KERNEL);
+	if (!utn->entries)
+		goto err_free_utn;
+
+	for (i = 0; i < n_tables; i++) {
+		utn->entries[i] = kcalloc(info->tables[i].n_entries,
+					  sizeof(*utn->entries[i]), GFP_KERNEL);
+		if (!utn->entries[i])
+			goto err_free_prev_entries;
+	}
+
+	return utn;
+
+err_free_prev_entries:
+	while (i--)
+		kfree(utn->entries[i]);
+	kfree(utn->entries);
+err_free_utn:
+	kfree(utn);
+	return NULL;
+}
+
+static void udp_tunnel_nic_free(struct udp_tunnel_nic *utn)
+{
+	unsigned int i;
+
+	for (i = 0; i < utn->n_tables; i++)
+		kfree(utn->entries[i]);
+	kfree(utn->entries);
+	kfree(utn);
+}
+
+static int udp_tunnel_nic_register(struct net_device *dev)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+	struct udp_tunnel_nic_shared_node *node = NULL;
+	struct udp_tunnel_nic *utn;
+	unsigned int n_tables, i;
+
+	BUILD_BUG_ON(sizeof(utn->missed) * BITS_PER_BYTE <
+		     UDP_TUNNEL_NIC_MAX_TABLES);
+	/* Expect use count of at most 2 (IPv4, IPv6) per device */
+	BUILD_BUG_ON(UDP_TUNNEL_NIC_USE_CNT_MAX <
+		     UDP_TUNNEL_NIC_MAX_SHARING_DEVICES * 2);
+
+	/* Check that the driver info is sane */
+	if (WARN_ON(!info->set_port != !info->unset_port) ||
+	    WARN_ON(!info->set_port == !info->sync_table) ||
+	    WARN_ON(!info->tables[0].n_entries))
+		return -EINVAL;
+
+	if (WARN_ON(info->shared &&
+		    info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
+		return -EINVAL;
+
+	n_tables = 1;
+	for (i = 1; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
+		if (!info->tables[i].n_entries)
+			continue;
+
+		n_tables++;
+		if (WARN_ON(!info->tables[i - 1].n_entries))
+			return -EINVAL;
+	}
+
+	/* Create UDP tunnel state structures */
+	if (info->shared) {
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node)
+			return -ENOMEM;
+
+		node->dev = dev;
+	}
+
+	if (info->shared && info->shared->udp_tunnel_nic_info) {
+		utn = info->shared->udp_tunnel_nic_info;
+	} else {
+		utn = udp_tunnel_nic_alloc(info, n_tables);
+		if (!utn) {
+			kfree(node);
+			return -ENOMEM;
+		}
+	}
+
+	if (info->shared) {
+		if (!info->shared->udp_tunnel_nic_info) {
+			INIT_LIST_HEAD(&info->shared->devices);
+			info->shared->udp_tunnel_nic_info = utn;
+		}
+
+		list_add_tail(&node->list, &info->shared->devices);
+	}
+
+	utn->dev = dev;
+	dev_hold(dev);
+	dev->udp_tunnel_nic = utn;
+
+	if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
+		udp_tunnel_get_rx_info(dev);
+
+	return 0;
+}
+
+static void
+udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn)
+{
+	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
+
+	/* For a shared table remove this dev from the list of sharing devices
+	 * and if there are other devices just detach.
+	 */
+	if (info->shared) {
+		struct udp_tunnel_nic_shared_node *node, *first;
+
+		list_for_each_entry(node, &info->shared->devices, list)
+			if (node->dev == dev)
+				break;
+		if (list_entry_is_head(node, &info->shared->devices, list))
+			return;
+
+		list_del(&node->list);
+		kfree(node);
+
+		first = list_first_entry_or_null(&info->shared->devices,
+						 typeof(*first), list);
+		if (first) {
+			udp_tunnel_drop_rx_info(dev);
+			utn->dev = first->dev;
+			goto release_dev;
+		}
+
+		info->shared->udp_tunnel_nic_info = NULL;
+	}
+
+	/* Flush before we check work, so we don't waste time adding entries
+	 * from the work which we will boot immediately.
+	 */
+	udp_tunnel_nic_flush(dev, utn);
+
+	/* Wait for the work to be done using the state, netdev core will
+	 * retry unregister until we give up our reference on this device.
+	 */
+	if (utn->work_pending)
+		return;
+
+	udp_tunnel_nic_free(utn);
+release_dev:
+	dev->udp_tunnel_nic = NULL;
+	dev_put(dev);
+}
+
+static int
+udp_tunnel_nic_netdevice_event(struct notifier_block *unused,
+			       unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	const struct udp_tunnel_nic_info *info;
+	struct udp_tunnel_nic *utn;
+
+	info = dev->udp_tunnel_nic_info;
+	if (!info)
+		return NOTIFY_DONE;
+
+	if (event == NETDEV_REGISTER) {
+		int err;
+
+		err = udp_tunnel_nic_register(dev);
+		if (err)
+			netdev_WARN(dev, "failed to register for UDP tunnel offloads: %d", err);
+		return notifier_from_errno(err);
+	}
+	/* All other events will need the udp_tunnel_nic state */
+	utn = dev->udp_tunnel_nic;
+	if (!utn)
+		return NOTIFY_DONE;
+
+	if (event == NETDEV_UNREGISTER) {
+		udp_tunnel_nic_unregister(dev, utn);
+		return NOTIFY_OK;
+	}
+
+	/* All other events only matter if NIC has to be programmed open */
+	if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
+		return NOTIFY_DONE;
+
+	if (event == NETDEV_UP) {
+		WARN_ON(!udp_tunnel_nic_is_empty(dev, utn));
+		udp_tunnel_get_rx_info(dev);
+		return NOTIFY_OK;
+	}
+	if (event == NETDEV_GOING_DOWN) {
+		udp_tunnel_nic_flush(dev, utn);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block udp_tunnel_nic_notifier_block __read_mostly = {
+	.notifier_call = udp_tunnel_nic_netdevice_event,
+};
+
+static int __init udp_tunnel_nic_init_module(void)
+{
+	int err;
+
+	udp_tunnel_nic_workqueue = alloc_ordered_workqueue("udp_tunnel_nic", 0);
+	if (!udp_tunnel_nic_workqueue)
+		return -ENOMEM;
+
+	rtnl_lock();
+	udp_tunnel_nic_ops = &__udp_tunnel_nic_ops;
+	rtnl_unlock();
+
+	err = register_netdevice_notifier(&udp_tunnel_nic_notifier_block);
+	if (err)
+		goto err_unset_ops;
+
+	return 0;
+
+err_unset_ops:
+	rtnl_lock();
+	udp_tunnel_nic_ops = NULL;
+	rtnl_unlock();
+	destroy_workqueue(udp_tunnel_nic_workqueue);
+	return err;
+}
+late_initcall(udp_tunnel_nic_init_module);
+
+static void __exit udp_tunnel_nic_cleanup_module(void)
+{
+	unregister_netdevice_notifier(&udp_tunnel_nic_notifier_block);
+
+	rtnl_lock();
+	udp_tunnel_nic_ops = NULL;
+	rtnl_unlock();
+
+	destroy_workqueue(udp_tunnel_nic_workqueue);
+}
+module_exit(udp_tunnel_nic_cleanup_module);
+
+MODULE_LICENSE("GPL");