Re: [PATCH v3 net-next 01/14] net: bridge: mst: Multiple Spanning Tree (MST) mode
From: Nikolay Aleksandrov <razor@blackwall.org>
Date: 2022-03-14 10:37:55
Also in:
bridge, lkml
On 14/03/2022 11:52, Tobias Waldekranz wrote:
Allow the user to switch from the current per-VLAN STP mode to an MST mode. Up to this point, per-VLAN STP states where always isolated from each other. This is in contrast to the MSTP standard (802.1Q-2018, Clause 13.5), where VLANs are grouped into MST instances (MSTIs), and the state is managed on a per-MSTI level, rather that at the per-VLAN level. Perhaps due to the prevalence of the standard, many switching ASICs are built after the same model. Therefore, add a corresponding MST mode to the bridge, which we can later add offloading support for in a straight-forward way. For now, all VLANs are fixed to MSTI 0, also called the Common Spanning Tree (CST). That is, all VLANs will follow the port-global state. Upcoming changes will make this actually useful by allowing VLANs to be mapped to arbitrary MSTIs and allow individual MSTI states to be changed. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> ---
[snip]
quoted hunk ↗ jump to hunk
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 48bc61ebc211..35b47f6b449a 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h@@ -178,6 +178,7 @@ enum { * @br_mcast_ctx: if MASTER flag set, this is the global vlan multicast context * @port_mcast_ctx: if MASTER flag unset, this is the per-port/vlan multicast * context + * @msti: if MASTER flag set, this holds the VLANs MST instance * @vlist: sorted list of VLAN entries * @rcu: used for entry destruction *@@ -210,6 +211,8 @@ struct net_bridge_vlan { struct net_bridge_mcast_port port_mcast_ctx; }; + u16 msti; + struct list_head vlist; struct rcu_head rcu;@@ -445,6 +448,7 @@ enum net_bridge_opts { BROPT_NO_LL_LEARN, BROPT_VLAN_BRIDGE_BINDING, BROPT_MCAST_VLAN_SNOOPING_ENABLED, + BROPT_MST_ENABLED, }; struct net_bridge {@@ -1765,6 +1769,29 @@ static inline bool br_vlan_state_allowed(u8 state, bool learn_allow) } #endif +/* br_mst.c */ +#ifdef CONFIG_BRIDGE_VLAN_FILTERING
There is already such ifdef, you can embed all MST code inside it.
quoted hunk ↗ jump to hunk
+DECLARE_STATIC_KEY_FALSE(br_mst_used); +static inline bool br_mst_is_enabled(struct net_bridge *br) +{ + return static_branch_unlikely(&br_mst_used) && + br_opt_get(br, BROPT_MST_ENABLED); +} + +void br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state); +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); +#else +static inline bool br_mst_is_enabled(struct net_bridge *br) +{ + return false; +} + +static inline void br_mst_set_state(struct net_bridge_port *p, + u16 msti, u8 state) {} +#endif + struct nf_br_ops { int (*br_dev_xmit_hook)(struct sk_buff *skb); };diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c index 1d80f34a139c..82a97a021a57 100644 --- a/net/bridge/br_stp.c +++ b/net/bridge/br_stp.c@@ -43,6 +43,9 @@ void br_set_state(struct net_bridge_port *p, unsigned int state) return; p->state = state; + if (br_opt_get(p->br, BROPT_MST_ENABLED)) + br_mst_set_state(p, 0, state); + err = switchdev_port_attr_set(p->dev, &attr, NULL); if (err && err != -EOPNOTSUPP) br_warn(p->br, "error setting offload STP state on port %u(%s)\n",diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index 7557e90b60e1..0f5e75ccac79 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c@@ -226,6 +226,24 @@ static void nbp_vlan_rcu_free(struct rcu_head *rcu) kfree(v); } +static void br_vlan_init_state(struct net_bridge_vlan *v) +{ + struct net_bridge *br; + + if (br_vlan_is_master(v)) + br = v->br; + else + br = v->port->br; + + if (br_opt_get(br, BROPT_MST_ENABLED)) { + br_mst_vlan_init_state(v); + return; + } + + v->state = BR_STATE_FORWARDING; + v->msti = 0; +} + /* This is the shared VLAN add function which works for both ports and bridge * devices. There are four possible calls to this function in terms of the * vlan entry type:@@ -322,7 +340,7 @@ static int __vlan_add(struct net_bridge_vlan *v, u16 flags, } /* set the state before publishing */ - v->state = BR_STATE_FORWARDING; + br_vlan_init_state(v); err = rhashtable_lookup_insert_fast(&vg->vlan_hash, &v->vnode, br_vlan_rht_params);diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c index a6382973b3e7..09112b56e79c 100644 --- a/net/bridge/br_vlan_options.c +++ b/net/bridge/br_vlan_options.c@@ -99,6 +99,11 @@ static int br_vlan_modify_state(struct net_bridge_vlan_group *vg, return -EBUSY; } + if (br_opt_get(br, BROPT_MST_ENABLED)) { + NL_SET_ERR_MSG_MOD(extack, "Can't modify vlan state directly when MST is enabled"); + return -EBUSY; + } + if (v->state == state) return 0;