linux/net/bridge/br_mst.c
Tobias Waldekranz f54fd0e163 net: bridge: mst: Add helper to query a port's MST state
This is useful for switchdev drivers who are offloading MST states
into hardware. As an example, a driver may wish to flush the FDB for a
port when it transitions from forwarding to blocking - which means
that the previous state must be discoverable.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 16:49:58 -07:00

358 lines
7.6 KiB
C

// 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;
}