Linux Ethernet Bridging - Jul 2020 - [Bridge] [PATCH net-next v3 2/3] bridge: mrp: Add br_mrp_fill_info

This patch series extends the MRP netlink interface to allow the userspace
daemon to get the status of the MRP instances in the kernel.

v3:
  - remove misleading comment
  - fix to use correctly the RCU

v2:
  - fix sparse warnings

Horatiu Vultur (3):
  bridge: uapi: mrp: Extend MRP attributes to get the status
  bridge: mrp: Add br_mrp_fill_info
  bridge: Extend br_fill_ifinfo to return MPR status

 include/uapi/linux/if_bridge.h | 17 +++++++++
 include/uapi/linux/rtnetlink.h |  1 +
 net/bridge/br_mrp_netlink.c    | 64 ++++++++++++++++++++++++++++++++++
 net/bridge/br_netlink.c        | 25 ++++++++++++-
 net/bridge/br_private.h        |  7 ++++
 5 files changed, 113 insertions(+), 1 deletion(-)

-- 
2.27.0

Add MRP attribute IFLA_BRIDGE_MRP_INFO to allow the userspace to get the
current state of the MRP instances. This is a nested attribute that
contains other attributes like, ring id, index of primary and secondary
port, priority, ring state, ring role.

Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
---
 include/uapi/linux/if_bridge.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index caa6914a3e53a..c114c1c2bd533 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -166,6 +166,7 @@ enum {
 	IFLA_BRIDGE_MRP_RING_STATE,
 	IFLA_BRIDGE_MRP_RING_ROLE,
 	IFLA_BRIDGE_MRP_START_TEST,
+	IFLA_BRIDGE_MRP_INFO,
 	__IFLA_BRIDGE_MRP_MAX,
 };
 
@@ -228,6 +229,22 @@ enum {
 
 #define IFLA_BRIDGE_MRP_START_TEST_MAX (__IFLA_BRIDGE_MRP_START_TEST_MAX - 1)
 
+enum {
+	IFLA_BRIDGE_MRP_INFO_UNSPEC,
+	IFLA_BRIDGE_MRP_INFO_RING_ID,
+	IFLA_BRIDGE_MRP_INFO_P_IFINDEX,
+	IFLA_BRIDGE_MRP_INFO_S_IFINDEX,
+	IFLA_BRIDGE_MRP_INFO_PRIO,
+	IFLA_BRIDGE_MRP_INFO_RING_STATE,
+	IFLA_BRIDGE_MRP_INFO_RING_ROLE,
+	IFLA_BRIDGE_MRP_INFO_TEST_INTERVAL,
+	IFLA_BRIDGE_MRP_INFO_TEST_MAX_MISS,
+	IFLA_BRIDGE_MRP_INFO_TEST_MONITOR,
+	__IFLA_BRIDGE_MRP_INFO_MAX,
+};
+
+#define IFLA_BRIDGE_MRP_INFO_MAX (__IFLA_BRIDGE_MRP_INFO_MAX - 1)
+
 struct br_mrp_instance {
 	__u32 ring_id;
 	__u32 p_ifindex;
-- 
2.27.0

Add the function br_mrp_fill_info which populates the MRP attributes
regarding the status of each MRP instance.

Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
---
 net/bridge/br_mrp_netlink.c | 64 +++++++++++++++++++++++++++++++++++++
 net/bridge/br_private.h     |  7 ++++
 2 files changed, 71 insertions(+)

diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
index 34b3a8776991f..c4f5c356811f3 100644
--- a/net/bridge/br_mrp_netlink.c
+++ b/net/bridge/br_mrp_netlink.c
@@ -304,6 +304,70 @@ int br_mrp_parse(struct net_bridge *br, struct
net_bridge_port *p,
 	return 0;
 }
 
+int br_mrp_fill_info(struct sk_buff *skb, struct net_bridge *br)
+{
+	struct nlattr *tb, *mrp_tb;
+	struct br_mrp *mrp;
+
+	mrp_tb = nla_nest_start_noflag(skb, IFLA_BRIDGE_MRP);
+	if (!mrp_tb)
+		return -EMSGSIZE;
+
+	list_for_each_entry_rcu(mrp, &br->mrp_list, list) {
+		struct net_bridge_port *p;
+
+		tb = nla_nest_start_noflag(skb, IFLA_BRIDGE_MRP_INFO);
+		if (!tb)
+			goto nla_info_failure;
+
+		if (nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_RING_ID,
+				mrp->ring_id))
+			goto nla_put_failure;
+
+		p = rcu_dereference(mrp->p_port);
+		if (p && nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_P_IFINDEX,
+				     p->dev->ifindex))
+			goto nla_put_failure;
+
+		p = rcu_dereference(mrp->s_port);
+		if (p && nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_S_IFINDEX,
+				     p->dev->ifindex))
+			goto nla_put_failure;
+
+		if (nla_put_u16(skb, IFLA_BRIDGE_MRP_INFO_PRIO,
+				mrp->prio))
+			goto nla_put_failure;
+		if (nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_RING_STATE,
+				mrp->ring_state))
+			goto nla_put_failure;
+		if (nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_RING_ROLE,
+				mrp->ring_role))
+			goto nla_put_failure;
+		if (nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_TEST_INTERVAL,
+				mrp->test_interval))
+			goto nla_put_failure;
+		if (nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_TEST_MAX_MISS,
+				mrp->test_max_miss))
+			goto nla_put_failure;
+		if (nla_put_u32(skb, IFLA_BRIDGE_MRP_INFO_TEST_MONITOR,
+				mrp->test_monitor))
+			goto nla_put_failure;
+
+		nla_nest_end(skb, tb);
+	}
+	nla_nest_end(skb, mrp_tb);
+
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(skb, tb);
+
+nla_info_failure:
+	nla_nest_cancel(skb, mrp_tb);
+
+	return -EMSGSIZE;
+}
+
 int br_mrp_port_open(struct net_device *dev, u8 loc)
 {
 	struct net_bridge_port *p;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 6a7d8e218ae7e..65d2c163a24ab 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1317,6 +1317,7 @@ int br_mrp_parse(struct net_bridge *br, struct
net_bridge_port *p,
 int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb);
 bool br_mrp_enabled(struct net_bridge *br);
 void br_mrp_port_del(struct net_bridge *br, struct net_bridge_port *p);
+int br_mrp_fill_info(struct sk_buff *skb, struct net_bridge *br);
 #else
 static inline int br_mrp_parse(struct net_bridge *br, struct net_bridge_port
*p,
 			       struct nlattr *attr, int cmd,
@@ -1339,6 +1340,12 @@ static inline void br_mrp_port_del(struct net_bridge *br,
 				   struct net_bridge_port *p)
 {
 }
+
+static inline int br_mrp_fill_info(struct sk_buff *skb, struct net_bridge *br)
+{
+	return 0;
+}
+
 #endif
 
 /* br_netlink.c */
-- 
2.27.0

This patch extends the function br_fill_ifinfo to return also the MRP
status for each instance on a bridge. It also adds a new filter
RTEXT_FILTER_MRP to return the MRP status only when this is set, not to
interfer with the vlans. The MRP status is return only on the bridge
interfaces.

Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
---
 include/uapi/linux/rtnetlink.h |  1 +
 net/bridge/br_netlink.c        | 25 ++++++++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 879e64950a0a2..9b814c92de123 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -778,6 +778,7 @@ enum {
 #define RTEXT_FILTER_BRVLAN	(1 << 1)
 #define RTEXT_FILTER_BRVLAN_COMPRESSED	(1 << 2)
 #define	RTEXT_FILTER_SKIP_STATS	(1 << 3)
+#define RTEXT_FILTER_MRP	(1 << 4)
 
 /* End of information exported to user level */
 
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 240e260e3461c..c532fa65c9834 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -453,6 +453,28 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 		rcu_read_unlock();
 		if (err)
 			goto nla_put_failure;
+
+		nla_nest_end(skb, af);
+	}
+
+	if (filter_mask & RTEXT_FILTER_MRP) {
+		struct nlattr *af;
+		int err;
+
+		if (!br_mrp_enabled(br) || port)
+			goto done;
+
+		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
+		if (!af)
+			goto nla_put_failure;
+
+		rcu_read_lock();
+		err = br_mrp_fill_info(skb, br);
+		rcu_read_unlock();
+
+		if (err)
+			goto nla_put_failure;
+
 		nla_nest_end(skb, af);
 	}
 
@@ -516,7 +538,8 @@ int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 	struct net_bridge_port *port = br_port_get_rtnl(dev);
 
 	if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN) &&
-	    !(filter_mask & RTEXT_FILTER_BRVLAN_COMPRESSED))
+	    !(filter_mask & RTEXT_FILTER_BRVLAN_COMPRESSED) &&
+	    !(filter_mask & RTEXT_FILTER_MRP))
 		return 0;
 
 	return br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, nlflags,
-- 
2.27.0

From: Horatiu Vultur <horatiu.vultur at microchip.com>
Date: Thu, 2 Jul 2020 10:13:04 +0200
> This patch series extends the MRP netlink interface to allow the userspace
> daemon to get the status of the MRP instances in the kernel.
> 
> v3:
>   - remove misleading comment
>   - fix to use correctly the RCU
> 
> v2:
>   - fix sparse warnings
Series applied, thank you.