v4.19.13 snapshot.
diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
new file mode 100644
index 0000000..7c87a2f
--- /dev/null
+++ b/net/bridge/br_sysfs_if.c
@@ -0,0 +1,409 @@
+/*
+ *	Sysfs attributes of bridge ports
+ *	Linux ethernet bridge
+ *
+ *	Authors:
+ *	Stephen Hemminger		<shemminger@osdl.org>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/capability.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/if_bridge.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/sched/signal.h>
+
+#include "br_private.h"
+
+struct brport_attribute {
+	struct attribute	attr;
+	ssize_t (*show)(struct net_bridge_port *, char *);
+	int (*store)(struct net_bridge_port *, unsigned long);
+	int (*store_raw)(struct net_bridge_port *, char *);
+};
+
+#define BRPORT_ATTR_RAW(_name, _mode, _show, _store)			\
+const struct brport_attribute brport_attr_##_name = {			\
+	.attr		= {.name = __stringify(_name),			\
+			   .mode = _mode },				\
+	.show		= _show,					\
+	.store_raw	= _store,					\
+};
+
+#define BRPORT_ATTR(_name, _mode, _show, _store)		\
+const struct brport_attribute brport_attr_##_name = { 	        \
+	.attr = {.name = __stringify(_name), 			\
+		 .mode = _mode },				\
+	.show	= _show,					\
+	.store	= _store,					\
+};
+
+#define BRPORT_ATTR_FLAG(_name, _mask)				\
+static ssize_t show_##_name(struct net_bridge_port *p, char *buf) \
+{								\
+	return sprintf(buf, "%d\n", !!(p->flags & _mask));	\
+}								\
+static int store_##_name(struct net_bridge_port *p, unsigned long v) \
+{								\
+	return store_flag(p, v, _mask);				\
+}								\
+static BRPORT_ATTR(_name, 0644,					\
+		   show_##_name, store_##_name)
+
+static int store_flag(struct net_bridge_port *p, unsigned long v,
+		      unsigned long mask)
+{
+	unsigned long flags;
+
+	flags = p->flags;
+
+	if (v)
+		flags |= mask;
+	else
+		flags &= ~mask;
+
+	if (flags != p->flags) {
+		p->flags = flags;
+		br_port_flags_change(p, mask);
+	}
+	return 0;
+}
+
+static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->path_cost);
+}
+
+static BRPORT_ATTR(path_cost, 0644,
+		   show_path_cost, br_stp_set_path_cost);
+
+static ssize_t show_priority(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->priority);
+}
+
+static BRPORT_ATTR(priority, 0644,
+			 show_priority, br_stp_set_port_priority);
+
+static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
+{
+	return br_show_bridge_id(buf, &p->designated_root);
+}
+static BRPORT_ATTR(designated_root, 0444, show_designated_root, NULL);
+
+static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
+{
+	return br_show_bridge_id(buf, &p->designated_bridge);
+}
+static BRPORT_ATTR(designated_bridge, 0444, show_designated_bridge, NULL);
+
+static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->designated_port);
+}
+static BRPORT_ATTR(designated_port, 0444, show_designated_port, NULL);
+
+static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->designated_cost);
+}
+static BRPORT_ATTR(designated_cost, 0444, show_designated_cost, NULL);
+
+static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "0x%x\n", p->port_id);
+}
+static BRPORT_ATTR(port_id, 0444, show_port_id, NULL);
+
+static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "0x%x\n", p->port_no);
+}
+
+static BRPORT_ATTR(port_no, 0444, show_port_no, NULL);
+
+static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->topology_change_ack);
+}
+static BRPORT_ATTR(change_ack, 0444, show_change_ack, NULL);
+
+static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->config_pending);
+}
+static BRPORT_ATTR(config_pending, 0444, show_config_pending, NULL);
+
+static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->state);
+}
+static BRPORT_ATTR(state, 0444, show_port_state, NULL);
+
+static ssize_t show_message_age_timer(struct net_bridge_port *p,
+					    char *buf)
+{
+	return sprintf(buf, "%ld\n", br_timer_value(&p->message_age_timer));
+}
+static BRPORT_ATTR(message_age_timer, 0444, show_message_age_timer, NULL);
+
+static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
+					    char *buf)
+{
+	return sprintf(buf, "%ld\n", br_timer_value(&p->forward_delay_timer));
+}
+static BRPORT_ATTR(forward_delay_timer, 0444, show_forward_delay_timer, NULL);
+
+static ssize_t show_hold_timer(struct net_bridge_port *p,
+					    char *buf)
+{
+	return sprintf(buf, "%ld\n", br_timer_value(&p->hold_timer));
+}
+static BRPORT_ATTR(hold_timer, 0444, show_hold_timer, NULL);
+
+static int store_flush(struct net_bridge_port *p, unsigned long v)
+{
+	br_fdb_delete_by_port(p->br, p, 0, 0); // Don't delete local entry
+	return 0;
+}
+static BRPORT_ATTR(flush, 0200, NULL, store_flush);
+
+static ssize_t show_group_fwd_mask(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%#x\n", p->group_fwd_mask);
+}
+
+static int store_group_fwd_mask(struct net_bridge_port *p,
+				unsigned long v)
+{
+	if (v & BR_GROUPFWD_MACPAUSE)
+		return -EINVAL;
+	p->group_fwd_mask = v;
+
+	return 0;
+}
+static BRPORT_ATTR(group_fwd_mask, 0644, show_group_fwd_mask,
+		   store_group_fwd_mask);
+
+static ssize_t show_backup_port(struct net_bridge_port *p, char *buf)
+{
+	struct net_bridge_port *backup_p;
+	int ret = 0;
+
+	rcu_read_lock();
+	backup_p = rcu_dereference(p->backup_port);
+	if (backup_p)
+		ret = sprintf(buf, "%s\n", backup_p->dev->name);
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static int store_backup_port(struct net_bridge_port *p, char *buf)
+{
+	struct net_device *backup_dev = NULL;
+	char *nl = strchr(buf, '\n');
+
+	if (nl)
+		*nl = '\0';
+
+	if (strlen(buf) > 0) {
+		backup_dev = __dev_get_by_name(dev_net(p->dev), buf);
+		if (!backup_dev)
+			return -ENOENT;
+	}
+
+	return nbp_backup_change(p, backup_dev);
+}
+static BRPORT_ATTR_RAW(backup_port, 0644, show_backup_port, store_backup_port);
+
+BRPORT_ATTR_FLAG(hairpin_mode, BR_HAIRPIN_MODE);
+BRPORT_ATTR_FLAG(bpdu_guard, BR_BPDU_GUARD);
+BRPORT_ATTR_FLAG(root_block, BR_ROOT_BLOCK);
+BRPORT_ATTR_FLAG(learning, BR_LEARNING);
+BRPORT_ATTR_FLAG(unicast_flood, BR_FLOOD);
+BRPORT_ATTR_FLAG(proxyarp, BR_PROXYARP);
+BRPORT_ATTR_FLAG(proxyarp_wifi, BR_PROXYARP_WIFI);
+BRPORT_ATTR_FLAG(multicast_flood, BR_MCAST_FLOOD);
+BRPORT_ATTR_FLAG(broadcast_flood, BR_BCAST_FLOOD);
+BRPORT_ATTR_FLAG(neigh_suppress, BR_NEIGH_SUPPRESS);
+BRPORT_ATTR_FLAG(isolated, BR_ISOLATED);
+
+#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
+static ssize_t show_multicast_router(struct net_bridge_port *p, char *buf)
+{
+	return sprintf(buf, "%d\n", p->multicast_router);
+}
+
+static int store_multicast_router(struct net_bridge_port *p,
+				      unsigned long v)
+{
+	return br_multicast_set_port_router(p, v);
+}
+static BRPORT_ATTR(multicast_router, 0644, show_multicast_router,
+		   store_multicast_router);
+
+BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
+BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UNICAST);
+#endif
+
+static const struct brport_attribute *brport_attrs[] = {
+	&brport_attr_path_cost,
+	&brport_attr_priority,
+	&brport_attr_port_id,
+	&brport_attr_port_no,
+	&brport_attr_designated_root,
+	&brport_attr_designated_bridge,
+	&brport_attr_designated_port,
+	&brport_attr_designated_cost,
+	&brport_attr_state,
+	&brport_attr_change_ack,
+	&brport_attr_config_pending,
+	&brport_attr_message_age_timer,
+	&brport_attr_forward_delay_timer,
+	&brport_attr_hold_timer,
+	&brport_attr_flush,
+	&brport_attr_hairpin_mode,
+	&brport_attr_bpdu_guard,
+	&brport_attr_root_block,
+	&brport_attr_learning,
+	&brport_attr_unicast_flood,
+#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
+	&brport_attr_multicast_router,
+	&brport_attr_multicast_fast_leave,
+	&brport_attr_multicast_to_unicast,
+#endif
+	&brport_attr_proxyarp,
+	&brport_attr_proxyarp_wifi,
+	&brport_attr_multicast_flood,
+	&brport_attr_broadcast_flood,
+	&brport_attr_group_fwd_mask,
+	&brport_attr_neigh_suppress,
+	&brport_attr_isolated,
+	&brport_attr_backup_port,
+	NULL
+};
+
+#define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
+
+static ssize_t brport_show(struct kobject *kobj,
+			   struct attribute *attr, char *buf)
+{
+	struct brport_attribute *brport_attr = to_brport_attr(attr);
+	struct net_bridge_port *p = kobj_to_brport(kobj);
+
+	if (!brport_attr->show)
+		return -EINVAL;
+
+	return brport_attr->show(p, buf);
+}
+
+static ssize_t brport_store(struct kobject *kobj,
+			    struct attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct brport_attribute *brport_attr = to_brport_attr(attr);
+	struct net_bridge_port *p = kobj_to_brport(kobj);
+	ssize_t ret = -EINVAL;
+	unsigned long val;
+	char *endp;
+
+	if (!ns_capable(dev_net(p->dev)->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (!rtnl_trylock())
+		return restart_syscall();
+
+	if (!p->dev || !p->br)
+		goto out_unlock;
+
+	if (brport_attr->store_raw) {
+		char *buf_copy;
+
+		buf_copy = kstrndup(buf, count, GFP_KERNEL);
+		if (!buf_copy) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+		spin_lock_bh(&p->br->lock);
+		ret = brport_attr->store_raw(p, buf_copy);
+		spin_unlock_bh(&p->br->lock);
+		kfree(buf_copy);
+	} else if (brport_attr->store) {
+		val = simple_strtoul(buf, &endp, 0);
+		if (endp == buf)
+			goto out_unlock;
+		spin_lock_bh(&p->br->lock);
+		ret = brport_attr->store(p, val);
+		spin_unlock_bh(&p->br->lock);
+	}
+
+	if (!ret) {
+		br_ifinfo_notify(RTM_NEWLINK, NULL, p);
+		ret = count;
+	}
+out_unlock:
+	rtnl_unlock();
+
+	return ret;
+}
+
+const struct sysfs_ops brport_sysfs_ops = {
+	.show = brport_show,
+	.store = brport_store,
+};
+
+/*
+ * Add sysfs entries to ethernet device added to a bridge.
+ * Creates a brport subdirectory with bridge attributes.
+ * Puts symlink in bridge's brif subdirectory
+ */
+int br_sysfs_addif(struct net_bridge_port *p)
+{
+	struct net_bridge *br = p->br;
+	const struct brport_attribute **a;
+	int err;
+
+	err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,
+				SYSFS_BRIDGE_PORT_LINK);
+	if (err)
+		return err;
+
+	for (a = brport_attrs; *a; ++a) {
+		err = sysfs_create_file(&p->kobj, &((*a)->attr));
+		if (err)
+			return err;
+	}
+
+	strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
+	return sysfs_create_link(br->ifobj, &p->kobj, p->sysfs_name);
+}
+
+/* Rename bridge's brif symlink */
+int br_sysfs_renameif(struct net_bridge_port *p)
+{
+	struct net_bridge *br = p->br;
+	int err;
+
+	/* If a rename fails, the rollback will cause another
+	 * rename call with the existing name.
+	 */
+	if (!strncmp(p->sysfs_name, p->dev->name, IFNAMSIZ))
+		return 0;
+
+	err = sysfs_rename_link(br->ifobj, &p->kobj,
+				p->sysfs_name, p->dev->name);
+	if (err)
+		netdev_notice(br->dev, "unable to rename link %s to %s",
+			      p->sysfs_name, p->dev->name);
+	else
+		strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
+
+	return err;
+}