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-rw-r--r--net/bridge/br_mst.c357
1 files changed, 357 insertions, 0 deletions
diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
new file mode 100644
index 000000000..ee680adce
--- /dev/null
+++ b/net/bridge/br_mst.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Bridge Multiple Spanning Tree Support
+ *
+ * Authors:
+ * Tobias Waldekranz <tobias@waldekranz.com>
+ */
+
+#include <linux/kernel.h>
+#include <net/switchdev.h>
+
+#include "br_private.h"
+
+DEFINE_STATIC_KEY_FALSE(br_mst_used);
+
+bool br_mst_enabled(const struct net_device *dev)
+{
+ if (!netif_is_bridge_master(dev))
+ return false;
+
+ return br_opt_get(netdev_priv(dev), BROPT_MST_ENABLED);
+}
+EXPORT_SYMBOL_GPL(br_mst_enabled);
+
+int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids)
+{
+ const struct net_bridge_vlan_group *vg;
+ const struct net_bridge_vlan *v;
+ const struct net_bridge *br;
+
+ ASSERT_RTNL();
+
+ if (!netif_is_bridge_master(dev))
+ return -EINVAL;
+
+ br = netdev_priv(dev);
+ if (!br_opt_get(br, BROPT_MST_ENABLED))
+ return -EINVAL;
+
+ vg = br_vlan_group(br);
+
+ list_for_each_entry(v, &vg->vlan_list, vlist) {
+ if (v->msti == msti)
+ __set_bit(v->vid, vids);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(br_mst_get_info);
+
+int br_mst_get_state(const struct net_device *dev, u16 msti, u8 *state)
+{
+ const struct net_bridge_port *p = NULL;
+ const struct net_bridge_vlan_group *vg;
+ const struct net_bridge_vlan *v;
+
+ ASSERT_RTNL();
+
+ p = br_port_get_check_rtnl(dev);
+ if (!p || !br_opt_get(p->br, BROPT_MST_ENABLED))
+ return -EINVAL;
+
+ vg = nbp_vlan_group(p);
+
+ list_for_each_entry(v, &vg->vlan_list, vlist) {
+ if (v->brvlan->msti == msti) {
+ *state = v->state;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(br_mst_get_state);
+
+static void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,
+ u8 state)
+{
+ struct net_bridge_vlan_group *vg = nbp_vlan_group(p);
+
+ if (v->state == state)
+ return;
+
+ br_vlan_set_state(v, state);
+
+ if (v->vid == vg->pvid)
+ br_vlan_set_pvid_state(vg, state);
+}
+
+int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state,
+ struct netlink_ext_ack *extack)
+{
+ struct switchdev_attr attr = {
+ .id = SWITCHDEV_ATTR_ID_PORT_MST_STATE,
+ .orig_dev = p->dev,
+ .u.mst_state = {
+ .msti = msti,
+ .state = state,
+ },
+ };
+ struct net_bridge_vlan_group *vg;
+ struct net_bridge_vlan *v;
+ int err;
+
+ vg = nbp_vlan_group(p);
+ if (!vg)
+ return 0;
+
+ /* MSTI 0 (CST) state changes are notified via the regular
+ * SWITCHDEV_ATTR_ID_PORT_STP_STATE.
+ */
+ if (msti) {
+ err = switchdev_port_attr_set(p->dev, &attr, extack);
+ if (err && err != -EOPNOTSUPP)
+ return err;
+ }
+
+ list_for_each_entry(v, &vg->vlan_list, vlist) {
+ if (v->brvlan->msti != msti)
+ continue;
+
+ br_mst_vlan_set_state(p, v, state);
+ }
+
+ return 0;
+}
+
+static void br_mst_vlan_sync_state(struct net_bridge_vlan *pv, u16 msti)
+{
+ struct net_bridge_vlan_group *vg = nbp_vlan_group(pv->port);
+ struct net_bridge_vlan *v;
+
+ list_for_each_entry(v, &vg->vlan_list, vlist) {
+ /* If this port already has a defined state in this
+ * MSTI (through some other VLAN membership), inherit
+ * it.
+ */
+ if (v != pv && v->brvlan->msti == msti) {
+ br_mst_vlan_set_state(pv->port, pv, v->state);
+ return;
+ }
+ }
+
+ /* Otherwise, start out in a new MSTI with all ports disabled. */
+ return br_mst_vlan_set_state(pv->port, pv, BR_STATE_DISABLED);
+}
+
+int br_mst_vlan_set_msti(struct net_bridge_vlan *mv, u16 msti)
+{
+ struct switchdev_attr attr = {
+ .id = SWITCHDEV_ATTR_ID_VLAN_MSTI,
+ .orig_dev = mv->br->dev,
+ .u.vlan_msti = {
+ .vid = mv->vid,
+ .msti = msti,
+ },
+ };
+ struct net_bridge_vlan_group *vg;
+ struct net_bridge_vlan *pv;
+ struct net_bridge_port *p;
+ int err;
+
+ if (mv->msti == msti)
+ return 0;
+
+ err = switchdev_port_attr_set(mv->br->dev, &attr, NULL);
+ if (err && err != -EOPNOTSUPP)
+ return err;
+
+ mv->msti = msti;
+
+ list_for_each_entry(p, &mv->br->port_list, list) {
+ vg = nbp_vlan_group(p);
+
+ pv = br_vlan_find(vg, mv->vid);
+ if (pv)
+ br_mst_vlan_sync_state(pv, msti);
+ }
+
+ return 0;
+}
+
+void br_mst_vlan_init_state(struct net_bridge_vlan *v)
+{
+ /* VLANs always start out in MSTI 0 (CST) */
+ v->msti = 0;
+
+ if (br_vlan_is_master(v))
+ v->state = BR_STATE_FORWARDING;
+ else
+ v->state = v->port->state;
+}
+
+int br_mst_set_enabled(struct net_bridge *br, bool on,
+ struct netlink_ext_ack *extack)
+{
+ struct switchdev_attr attr = {
+ .id = SWITCHDEV_ATTR_ID_BRIDGE_MST,
+ .orig_dev = br->dev,
+ .u.mst = on,
+ };
+ struct net_bridge_vlan_group *vg;
+ struct net_bridge_port *p;
+ int err;
+
+ list_for_each_entry(p, &br->port_list, list) {
+ vg = nbp_vlan_group(p);
+
+ if (!vg->num_vlans)
+ continue;
+
+ NL_SET_ERR_MSG(extack,
+ "MST mode can't be changed while VLANs exist");
+ return -EBUSY;
+ }
+
+ if (br_opt_get(br, BROPT_MST_ENABLED) == on)
+ return 0;
+
+ err = switchdev_port_attr_set(br->dev, &attr, extack);
+ if (err && err != -EOPNOTSUPP)
+ return err;
+
+ if (on)
+ static_branch_enable(&br_mst_used);
+ else
+ static_branch_disable(&br_mst_used);
+
+ br_opt_toggle(br, BROPT_MST_ENABLED, on);
+ return 0;
+}
+
+size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
+{
+ DECLARE_BITMAP(seen, VLAN_N_VID) = { 0 };
+ const struct net_bridge_vlan *v;
+ size_t sz;
+
+ /* IFLA_BRIDGE_MST */
+ sz = nla_total_size(0);
+
+ list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
+ if (test_bit(v->brvlan->msti, seen))
+ continue;
+
+ /* IFLA_BRIDGE_MST_ENTRY */
+ sz += nla_total_size(0) +
+ /* IFLA_BRIDGE_MST_ENTRY_MSTI */
+ nla_total_size(sizeof(u16)) +
+ /* IFLA_BRIDGE_MST_ENTRY_STATE */
+ nla_total_size(sizeof(u8));
+
+ __set_bit(v->brvlan->msti, seen);
+ }
+
+ return sz;
+}
+
+int br_mst_fill_info(struct sk_buff *skb,
+ const struct net_bridge_vlan_group *vg)
+{
+ DECLARE_BITMAP(seen, VLAN_N_VID) = { 0 };
+ const struct net_bridge_vlan *v;
+ struct nlattr *nest;
+ int err = 0;
+
+ list_for_each_entry(v, &vg->vlan_list, vlist) {
+ if (test_bit(v->brvlan->msti, seen))
+ continue;
+
+ nest = nla_nest_start_noflag(skb, IFLA_BRIDGE_MST_ENTRY);
+ if (!nest ||
+ nla_put_u16(skb, IFLA_BRIDGE_MST_ENTRY_MSTI, v->brvlan->msti) ||
+ nla_put_u8(skb, IFLA_BRIDGE_MST_ENTRY_STATE, v->state)) {
+ err = -EMSGSIZE;
+ break;
+ }
+ nla_nest_end(skb, nest);
+
+ __set_bit(v->brvlan->msti, seen);
+ }
+
+ return err;
+}
+
+static const struct nla_policy br_mst_nl_policy[IFLA_BRIDGE_MST_ENTRY_MAX + 1] = {
+ [IFLA_BRIDGE_MST_ENTRY_MSTI] = NLA_POLICY_RANGE(NLA_U16,
+ 1, /* 0 reserved for CST */
+ VLAN_N_VID - 1),
+ [IFLA_BRIDGE_MST_ENTRY_STATE] = NLA_POLICY_RANGE(NLA_U8,
+ BR_STATE_DISABLED,
+ BR_STATE_BLOCKING),
+};
+
+static int br_mst_process_one(struct net_bridge_port *p,
+ const struct nlattr *attr,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[IFLA_BRIDGE_MST_ENTRY_MAX + 1];
+ u16 msti;
+ u8 state;
+ int err;
+
+ err = nla_parse_nested(tb, IFLA_BRIDGE_MST_ENTRY_MAX, attr,
+ br_mst_nl_policy, extack);
+ if (err)
+ return err;
+
+ if (!tb[IFLA_BRIDGE_MST_ENTRY_MSTI]) {
+ NL_SET_ERR_MSG_MOD(extack, "MSTI not specified");
+ return -EINVAL;
+ }
+
+ if (!tb[IFLA_BRIDGE_MST_ENTRY_STATE]) {
+ NL_SET_ERR_MSG_MOD(extack, "State not specified");
+ return -EINVAL;
+ }
+
+ msti = nla_get_u16(tb[IFLA_BRIDGE_MST_ENTRY_MSTI]);
+ state = nla_get_u8(tb[IFLA_BRIDGE_MST_ENTRY_STATE]);
+
+ return br_mst_set_state(p, msti, state, extack);
+}
+
+int br_mst_process(struct net_bridge_port *p, const struct nlattr *mst_attr,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *attr;
+ int err, msts = 0;
+ int rem;
+
+ if (!br_opt_get(p->br, BROPT_MST_ENABLED)) {
+ NL_SET_ERR_MSG_MOD(extack, "Can't modify MST state when MST is disabled");
+ return -EBUSY;
+ }
+
+ nla_for_each_nested(attr, mst_attr, rem) {
+ switch (nla_type(attr)) {
+ case IFLA_BRIDGE_MST_ENTRY:
+ err = br_mst_process_one(p, attr, extack);
+ break;
+ default:
+ continue;
+ }
+
+ msts++;
+ if (err)
+ break;
+ }
+
+ if (!msts) {
+ NL_SET_ERR_MSG_MOD(extack, "Found no MST entries to process");
+ err = -EINVAL;
+ }
+
+ return err;
+}