[PATCH v5 net-next 03/15] net: bridge: mst: Support setting and reporting MST port states

Tobias Waldekranz
2022-03-16T15:09:31Z

Make it possible to change the port state in a given MSTI by extending
the bridge port netlink interface (RTM_SETLINK on PF_BRIDGE).The
proposed iproute2 interface would be:

bridge mst set dev <PORT> msti <MSTI> state <STATE>

Current states in all applicable MSTIs can also be dumped via a
corresponding RTM_GETLINK. The proposed iproute interface looks like
this:

$ bridge mst
port msti
vb1 0
state forwarding
100
state disabled
vb2 0
state forwarding
100
state forwarding

The preexisting per-VLAN states are still valid in the MST
mode (although they are read-only), and can be queried as usual if one
is interested in knowing a particular VLAN's state without having to
care about the VID to MSTI mapping (in this example VLAN 20 and 30 are
bound to MSTI 100):

$ bridge -d vlan
port vlan-id
vb1 10
state forwarding mcast_router 1
20
state disabled mcast_router 1
30
state disabled mcast_router 1
40
state forwarding mcast_router 1
vb2 10
state forwarding mcast_router 1
20
state forwarding mcast_router 1
30
state forwarding mcast_router 1
40
state forwarding mcast_router 1

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
---
include/uapi/linux/if_bridge.h | 16 +++++
include/uapi/linux/rtnetlink.h | 1 +
net/bridge/br_mst.c | 126 +++++++++++++++++++++++++++++++++
net/bridge/br_netlink.c | 44 +++++++++++-
net/bridge/br_private.h | 23 ++++++
5 files changed, 209 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index f60244b747ae..a86a7e7b811f 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -122,6 +122,7 @@ enum {
IFLA_BRIDGE_VLAN_TUNNEL_INFO,
IFLA_BRIDGE_MRP,
IFLA_BRIDGE_CFM,
+ IFLA_BRIDGE_MST,
__IFLA_BRIDGE_MAX,
};
#define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)
@@ -453,6 +454,21 @@ enum {

#define IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX (__IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX - 1)

+enum {
+ IFLA_BRIDGE_MST_UNSPEC,
+ IFLA_BRIDGE_MST_ENTRY,
+ __IFLA_BRIDGE_MST_MAX,
+};
+#define IFLA_BRIDGE_MST_MAX (__IFLA_BRIDGE_MST_MAX - 1)
+
+enum {
+ IFLA_BRIDGE_MST_ENTRY_UNSPEC,
+ IFLA_BRIDGE_MST_ENTRY_MSTI,
+ IFLA_BRIDGE_MST_ENTRY_STATE,
+ __IFLA_BRIDGE_MST_ENTRY_MAX,
+};
+#define IFLA_BRIDGE_MST_ENTRY_MAX (__IFLA_BRIDGE_MST_ENTRY_MAX - 1)
+
struct bridge_stp_xstats {
__u64 transition_blk;
__u64 transition_fwd;
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 51530aade46e..83849a37db5b 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -817,6 +817,7 @@ enum {
#define RTEXT_FILTER_MRP (1 << 4)
#define RTEXT_FILTER_CFM_CONFIG (1 << 5)
#define RTEXT_FILTER_CFM_STATUS (1 << 6)
+#define RTEXT_FILTER_MST (1 << 7)

/* End of information exported to user level */

diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index d7a7b5d7ddb3..5c1831c73fc2 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -127,3 +127,129 @@ int br_mst_set_enabled(struct net_bridge *br, bool on,
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;
+}
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 7d4432ca9a20..a8d90fa8621e 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -119,6 +119,9 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
/* Each VLAN is returned in bridge_vlan_info along with flags */
vinfo_sz += num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));

+ if (filter_mask & RTEXT_FILTER_MST)
+ vinfo_sz += br_mst_info_size(vg);
+
if (!(filter_mask & RTEXT_FILTER_CFM_STATUS))
return vinfo_sz;

@@ -485,7 +488,8 @@ static int br_fill_ifinfo(struct sk_buff *skb,
RTEXT_FILTER_BRVLAN_COMPRESSED |
RTEXT_FILTER_MRP |
RTEXT_FILTER_CFM_CONFIG |
- RTEXT_FILTER_CFM_STATUS)) {
+ RTEXT_FILTER_CFM_STATUS |
+ RTEXT_FILTER_MST)) {
af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
if (!af)
goto nla_put_failure;
@@ -564,7 +568,28 @@ static int br_fill_ifinfo(struct sk_buff *skb,
nla_nest_end(skb, cfm_nest);
}

+ if ((filter_mask & RTEXT_FILTER_MST) &&
+ br_opt_get(br, BROPT_MST_ENABLED) && port) {
+ const struct net_bridge_vlan_group *vg = nbp_vlan_group(port);
+ struct nlattr *mst_nest;
+ int err;
+
+ if (!vg || !vg->num_vlans)
+ goto done;
+
+ mst_nest = nla_nest_start(skb, IFLA_BRIDGE_MST);
+ if (!mst_nest)
+ goto nla_put_failure;
+
+ err = br_mst_fill_info(skb, vg);
+ if (err)
+ goto nla_put_failure;
+
+ nla_nest_end(skb, mst_nest);
+ }
+
done:
+
if (af)
nla_nest_end(skb, af);
nlmsg_end(skb, nlh);
@@ -803,6 +828,23 @@ static int br_afspec(struct net_bridge *br,
if (err)
return err;
break;
+ case IFLA_BRIDGE_MST:
+ if (!p) {
+ NL_SET_ERR_MSG(extack,
+ "MST states can only be set on bridge ports");
+ return -EINVAL;
+ }
+
+ if (cmd != RTM_SETLINK) {
+ NL_SET_ERR_MSG(extack,
+ "MST states can only be set through RTM_SETLINK");
+ return -EINVAL;
+ }
+
+ err = br_mst_process(p, attr, extack);
+ if (err)
+ return err;
+ break;
}
}

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3978e1d9ffb5..18ccc3d5d296 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1784,6 +1784,11 @@ 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);
+size_t br_mst_info_size(const struct net_bridge_vlan_group *vg);
+int br_mst_fill_info(struct sk_buff *skb,
+ const struct net_bridge_vlan_group *vg);
+int br_mst_process(struct net_bridge_port *p, const struct nlattr *mst_attr,
+ struct netlink_ext_ack *extack);
#else
static inline bool br_mst_is_enabled(struct net_bridge *br)
{
@@ -1801,6 +1806,24 @@ static inline int br_mst_set_enabled(struct net_bridge *br, bool on,
{
return -EOPNOTSUPP;
}
+
+static inline size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
+{
+ return 0;
+}
+
+static inline int br_mst_fill_info(struct sk_buff *skb,
+ const struct net_bridge_vlan_group *vg)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int br_mst_process(struct net_bridge_port *p,
+ const struct nlattr *mst_attr,
+ struct netlink_ext_ack *extack)
+{
+ return -EOPNOTSUPP;
+}
#endif

struct nf_br_ops {
--
2.25.1