v4.19.13 snapshot.
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
new file mode 100644
index 0000000..808e2b9
--- /dev/null
+++ b/net/bridge/br_stp_if.c
@@ -0,0 +1,345 @@
+/*
+ * Spanning tree protocol; interface code
+ * Linux ethernet bridge
+ *
+ * Authors:
+ * Lennert Buytenhek <buytenh@gnu.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/kernel.h>
+#include <linux/kmod.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <net/switchdev.h>
+
+#include "br_private.h"
+#include "br_private_stp.h"
+
+
+/* Port id is composed of priority and port number.
+ * NB: some bits of priority are dropped to
+ * make room for more ports.
+ */
+static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
+{
+ return ((u16)priority << BR_PORT_BITS)
+ | (port_no & ((1<<BR_PORT_BITS)-1));
+}
+
+#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
+
+/* called under bridge lock */
+void br_init_port(struct net_bridge_port *p)
+{
+ int err;
+
+ p->port_id = br_make_port_id(p->priority, p->port_no);
+ br_become_designated_port(p);
+ br_set_state(p, BR_STATE_BLOCKING);
+ p->topology_change_ack = 0;
+ p->config_pending = 0;
+
+ err = __set_ageing_time(p->dev, p->br->ageing_time);
+ if (err)
+ netdev_err(p->dev, "failed to offload ageing time\n");
+}
+
+/* NO locks held */
+void br_stp_enable_bridge(struct net_bridge *br)
+{
+ struct net_bridge_port *p;
+
+ spin_lock_bh(&br->lock);
+ if (br->stp_enabled == BR_KERNEL_STP)
+ mod_timer(&br->hello_timer, jiffies + br->hello_time);
+ mod_delayed_work(system_long_wq, &br->gc_work, HZ / 10);
+
+ br_config_bpdu_generation(br);
+
+ list_for_each_entry(p, &br->port_list, list) {
+ if (netif_running(p->dev) && netif_oper_up(p->dev))
+ br_stp_enable_port(p);
+
+ }
+ spin_unlock_bh(&br->lock);
+}
+
+/* NO locks held */
+void br_stp_disable_bridge(struct net_bridge *br)
+{
+ struct net_bridge_port *p;
+
+ spin_lock_bh(&br->lock);
+ list_for_each_entry(p, &br->port_list, list) {
+ if (p->state != BR_STATE_DISABLED)
+ br_stp_disable_port(p);
+
+ }
+
+ __br_set_topology_change(br, 0);
+ br->topology_change_detected = 0;
+ spin_unlock_bh(&br->lock);
+
+ del_timer_sync(&br->hello_timer);
+ del_timer_sync(&br->topology_change_timer);
+ del_timer_sync(&br->tcn_timer);
+ cancel_delayed_work_sync(&br->gc_work);
+}
+
+/* called under bridge lock */
+void br_stp_enable_port(struct net_bridge_port *p)
+{
+ br_init_port(p);
+ br_port_state_selection(p->br);
+ br_ifinfo_notify(RTM_NEWLINK, NULL, p);
+}
+
+/* called under bridge lock */
+void br_stp_disable_port(struct net_bridge_port *p)
+{
+ struct net_bridge *br = p->br;
+ int wasroot;
+
+ wasroot = br_is_root_bridge(br);
+ br_become_designated_port(p);
+ br_set_state(p, BR_STATE_DISABLED);
+ p->topology_change_ack = 0;
+ p->config_pending = 0;
+
+ br_ifinfo_notify(RTM_NEWLINK, NULL, p);
+
+ del_timer(&p->message_age_timer);
+ del_timer(&p->forward_delay_timer);
+ del_timer(&p->hold_timer);
+
+ br_fdb_delete_by_port(br, p, 0, 0);
+ br_multicast_disable_port(p);
+
+ br_configuration_update(br);
+
+ br_port_state_selection(br);
+
+ if (br_is_root_bridge(br) && !wasroot)
+ br_become_root_bridge(br);
+}
+
+static int br_stp_call_user(struct net_bridge *br, char *arg)
+{
+ char *argv[] = { BR_STP_PROG, br->dev->name, arg, NULL };
+ char *envp[] = { NULL };
+ int rc;
+
+ /* call userspace STP and report program errors */
+ rc = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+ if (rc > 0) {
+ if (rc & 0xff)
+ br_debug(br, BR_STP_PROG " received signal %d\n",
+ rc & 0x7f);
+ else
+ br_debug(br, BR_STP_PROG " exited with code %d\n",
+ (rc >> 8) & 0xff);
+ }
+
+ return rc;
+}
+
+static void br_stp_start(struct net_bridge *br)
+{
+ int err = -ENOENT;
+
+ if (net_eq(dev_net(br->dev), &init_net))
+ err = br_stp_call_user(br, "start");
+
+ if (err && err != -ENOENT)
+ br_err(br, "failed to start userspace STP (%d)\n", err);
+
+ spin_lock_bh(&br->lock);
+
+ if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
+ __br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
+ else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
+ __br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
+
+ if (!err) {
+ br->stp_enabled = BR_USER_STP;
+ br_debug(br, "userspace STP started\n");
+ } else {
+ br->stp_enabled = BR_KERNEL_STP;
+ br_debug(br, "using kernel STP\n");
+
+ /* To start timers on any ports left in blocking */
+ if (br->dev->flags & IFF_UP)
+ mod_timer(&br->hello_timer, jiffies + br->hello_time);
+ br_port_state_selection(br);
+ }
+
+ spin_unlock_bh(&br->lock);
+}
+
+static void br_stp_stop(struct net_bridge *br)
+{
+ int err;
+
+ if (br->stp_enabled == BR_USER_STP) {
+ err = br_stp_call_user(br, "stop");
+ if (err)
+ br_err(br, "failed to stop userspace STP (%d)\n", err);
+
+ /* To start timers on any ports left in blocking */
+ spin_lock_bh(&br->lock);
+ br_port_state_selection(br);
+ spin_unlock_bh(&br->lock);
+ }
+
+ br->stp_enabled = BR_NO_STP;
+}
+
+void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
+{
+ ASSERT_RTNL();
+
+ if (val) {
+ if (br->stp_enabled == BR_NO_STP)
+ br_stp_start(br);
+ } else {
+ if (br->stp_enabled != BR_NO_STP)
+ br_stp_stop(br);
+ }
+}
+
+/* called under bridge lock */
+void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
+{
+ /* should be aligned on 2 bytes for ether_addr_equal() */
+ unsigned short oldaddr_aligned[ETH_ALEN >> 1];
+ unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
+ struct net_bridge_port *p;
+ int wasroot;
+
+ wasroot = br_is_root_bridge(br);
+
+ br_fdb_change_mac_address(br, addr);
+
+ memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
+ memcpy(br->bridge_id.addr, addr, ETH_ALEN);
+ memcpy(br->dev->dev_addr, addr, ETH_ALEN);
+
+ list_for_each_entry(p, &br->port_list, list) {
+ if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
+ memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
+
+ if (ether_addr_equal(p->designated_root.addr, oldaddr))
+ memcpy(p->designated_root.addr, addr, ETH_ALEN);
+ }
+
+ br_configuration_update(br);
+ br_port_state_selection(br);
+ if (br_is_root_bridge(br) && !wasroot)
+ br_become_root_bridge(br);
+}
+
+/* should be aligned on 2 bytes for ether_addr_equal() */
+static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
+
+/* called under bridge lock */
+bool br_stp_recalculate_bridge_id(struct net_bridge *br)
+{
+ const unsigned char *br_mac_zero =
+ (const unsigned char *)br_mac_zero_aligned;
+ const unsigned char *addr = br_mac_zero;
+ struct net_bridge_port *p;
+
+ /* user has chosen a value so keep it */
+ if (br->dev->addr_assign_type == NET_ADDR_SET)
+ return false;
+
+ list_for_each_entry(p, &br->port_list, list) {
+ if (addr == br_mac_zero ||
+ memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
+ addr = p->dev->dev_addr;
+
+ }
+
+ if (ether_addr_equal(br->bridge_id.addr, addr))
+ return false; /* no change */
+
+ br_stp_change_bridge_id(br, addr);
+ return true;
+}
+
+/* Acquires and releases bridge lock */
+void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
+{
+ struct net_bridge_port *p;
+ int wasroot;
+
+ spin_lock_bh(&br->lock);
+ wasroot = br_is_root_bridge(br);
+
+ list_for_each_entry(p, &br->port_list, list) {
+ if (p->state != BR_STATE_DISABLED &&
+ br_is_designated_port(p)) {
+ p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
+ p->designated_bridge.prio[1] = newprio & 0xFF;
+ }
+
+ }
+
+ br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
+ br->bridge_id.prio[1] = newprio & 0xFF;
+ br_configuration_update(br);
+ br_port_state_selection(br);
+ if (br_is_root_bridge(br) && !wasroot)
+ br_become_root_bridge(br);
+ spin_unlock_bh(&br->lock);
+}
+
+/* called under bridge lock */
+int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
+{
+ port_id new_port_id;
+
+ if (newprio > BR_MAX_PORT_PRIORITY)
+ return -ERANGE;
+
+ new_port_id = br_make_port_id(newprio, p->port_no);
+ if (br_is_designated_port(p))
+ p->designated_port = new_port_id;
+
+ p->port_id = new_port_id;
+ p->priority = newprio;
+ if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
+ p->port_id < p->designated_port) {
+ br_become_designated_port(p);
+ br_port_state_selection(p->br);
+ }
+
+ return 0;
+}
+
+/* called under bridge lock */
+int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
+{
+ if (path_cost < BR_MIN_PATH_COST ||
+ path_cost > BR_MAX_PATH_COST)
+ return -ERANGE;
+
+ p->flags |= BR_ADMIN_COST;
+ p->path_cost = path_cost;
+ br_configuration_update(p->br);
+ br_port_state_selection(p->br);
+ return 0;
+}
+
+ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
+{
+ return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
+ id->prio[0], id->prio[1],
+ id->addr[0], id->addr[1], id->addr[2],
+ id->addr[3], id->addr[4], id->addr[5]);
+}