[PATCH v5 net-next 02/15] net: bridge: mst: Allow changing a VLAN's MSTI

Tobias Waldekranz
2022-03-16T15:09:18Z

Allow a VLAN to move out of the CST (MSTI 0), to an independent tree.

The user manages the VID to MSTI mappings via a global VLAN
setting. The proposed iproute2 interface would be:

bridge vlan global set dev br0 vid <VID> msti <MSTI>

Changing the state in non-zero MSTIs is still not supported, but will
be addressed in upcoming changes.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
---
include/uapi/linux/if_bridge.h | 1 +
net/bridge/br_mst.c | 42 ++++++++++++++++++++++++++++++++++
net/bridge/br_private.h | 1 +
net/bridge/br_vlan_options.c | 15 ++++++++++++
4 files changed, 59 insertions(+)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index 30a242195ced..f60244b747ae 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -564,6 +564,7 @@ enum {
BRIDGE_VLANDB_GOPTS_MCAST_QUERIER,
BRIDGE_VLANDB_GOPTS_MCAST_ROUTER_PORTS,
BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_STATE,
+ BRIDGE_VLANDB_GOPTS_MSTI,
__BRIDGE_VLANDB_GOPTS_MAX
};
#define BRIDGE_VLANDB_GOPTS_MAX (__BRIDGE_VLANDB_GOPTS_MAX - 1)
diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index 0f9f596f86bc..d7a7b5d7ddb3 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -46,6 +46,48 @@ int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 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 net_bridge_vlan_group *vg;
+ struct net_bridge_vlan *pv;
+ struct net_bridge_port *p;
+
+ if (mv->msti == msti)
+ return 0;
+
+ 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) */
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index c2190c8841fb..3978e1d9ffb5 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1780,6 +1780,7 @@ static inline bool br_mst_is_enabled(struct net_bridge *br)

int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state,
struct netlink_ext_ack *extack);
+int br_mst_vlan_set_msti(struct net_bridge_vlan *v, u16 msti);
void br_mst_vlan_init_state(struct net_bridge_vlan *v);
int br_mst_set_enabled(struct net_bridge *br, bool on,
struct netlink_ext_ack *extack);
diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c
index 09112b56e79c..a2724d03278c 100644
--- a/net/bridge/br_vlan_options.c
+++ b/net/bridge/br_vlan_options.c
@@ -296,6 +296,7 @@ bool br_vlan_global_opts_can_enter_range(const struct net_bridge_vlan *v_curr,
const struct net_bridge_vlan *r_end)
{
return v_curr->vid - r_end->vid == 1 &&
+ v_curr->msti == r_end->msti &&
((v_curr->priv_flags ^ r_end->priv_flags) &
BR_VLFLAG_GLOBAL_MCAST_ENABLED) == 0 &&
br_multicast_ctx_options_equal(&v_curr->br_mcast_ctx,
@@ -384,6 +385,9 @@ bool br_vlan_global_opts_fill(struct sk_buff *skb, u16 vid, u16 vid_range,
#endif
#endif

+ if (nla_put_u16(skb, BRIDGE_VLANDB_GOPTS_MSTI, v_opts->msti))
+ goto out_err;
+
nla_nest_end(skb, nest);

return true;
@@ -415,6 +419,7 @@ static size_t rtnl_vlan_global_opts_nlmsg_size(const struct net_bridge_vlan *v)
+ nla_total_size(0) /* BRIDGE_VLANDB_GOPTS_MCAST_ROUTER_PORTS */
+ br_rports_size(&v->br_mcast_ctx) /* BRIDGE_VLANDB_GOPTS_MCAST_ROUTER_PORTS */
#endif
+ + nla_total_size(sizeof(u16)) /* BRIDGE_VLANDB_GOPTS_MSTI */
+ nla_total_size(sizeof(u16)); /* BRIDGE_VLANDB_GOPTS_RANGE */
}

@@ -564,6 +569,15 @@ static int br_vlan_process_global_one_opts(const struct net_bridge *br,
}
#endif
#endif
+ if (tb[BRIDGE_VLANDB_GOPTS_MSTI]) {
+ u16 msti;
+
+ msti = nla_get_u16(tb[BRIDGE_VLANDB_GOPTS_MSTI]);
+ err = br_mst_vlan_set_msti(v, msti);
+ if (err)
+ return err;
+ *changed = true;
+ }

return 0;
}
@@ -583,6 +597,7 @@ static const struct nla_policy br_vlan_db_gpol[BRIDGE_VLANDB_GOPTS_MAX + 1] = {
[BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_INTVL] = { .type = NLA_U64 },
[BRIDGE_VLANDB_GOPTS_MCAST_STARTUP_QUERY_INTVL] = { .type = NLA_U64 },
[BRIDGE_VLANDB_GOPTS_MCAST_QUERY_RESPONSE_INTVL] = { .type = NLA_U64 },
+ [BRIDGE_VLANDB_GOPTS_MSTI] = NLA_POLICY_MAX(NLA_U16, VLAN_N_VID - 1),
};

int br_vlan_rtm_process_global_options(struct net_device *dev,
--
2.25.1