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Horatiu Vultur

2020-Jun-24 08:05 UTC

[Bridge] [PATCH net-next] bridge: mrp: Extend MRP netlink interface with IFLA_BRIDGE_MRP_CLEAR

In case the userspace daemon dies, then when is restarted it doesn't
know if there are any MRP instances in the kernel. Therefore extend the
netlink interface to allow the daemon to clear all MRP instances when is
started.

Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
---
 include/uapi/linux/if_bridge.h |  8 ++++++++
 net/bridge/br_mrp.c            | 15 +++++++++++++++
 net/bridge/br_mrp_netlink.c    | 26 ++++++++++++++++++++++++++
 net/bridge/br_private_mrp.h    |  1 +
 4 files changed, 50 insertions(+)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index caa6914a3e53a..2ae7d0c0d46b8 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_CLEAR,
 	__IFLA_BRIDGE_MRP_MAX,
 };
 
@@ -228,6 +229,13 @@ enum {
 
 #define IFLA_BRIDGE_MRP_START_TEST_MAX (__IFLA_BRIDGE_MRP_START_TEST_MAX - 1)
 
+enum {
+	IFLA_BRIDGE_MRP_CLEAR_UNSPEC,
+	__IFLA_BRIDGE_MRP_CLEAR_MAX,
+};
+
+#define IFLA_BRIDGE_MRP_CLEAR_MAX (__IFLA_BRIDGE_MRP_CLEAR_MAX - 1)
+
 struct br_mrp_instance {
 	__u32 ring_id;
 	__u32 p_ifindex;
diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
index 24986ec7d38cc..02d102edaaaad 100644
--- a/net/bridge/br_mrp.c
+++ b/net/bridge/br_mrp.c
@@ -372,6 +372,21 @@ int br_mrp_del(struct net_bridge *br, struct
br_mrp_instance *instance)
 	return 0;
 }
 
+/* Deletes all MRP instances on the bridge
+ * note: called under rtnl_lock
+ */
+int br_mrp_clear(struct net_bridge *br)
+{
+	struct br_mrp *mrp;
+
+	list_for_each_entry_rcu(mrp, &br->mrp_list, list,
+				lockdep_rtnl_is_held()) {
+		br_mrp_del_impl(br, mrp);
+	}
+
+	return 0;
+}
+
 /* Set port state, port state can be forwarding, blocked or disabled
  * note: already called with rtnl_lock
  */
diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
index 34b3a8776991f..5e743538464f6 100644
--- a/net/bridge/br_mrp_netlink.c
+++ b/net/bridge/br_mrp_netlink.c
@@ -14,6 +14,7 @@ static const struct nla_policy
br_mrp_policy[IFLA_BRIDGE_MRP_MAX + 1] = {
 	[IFLA_BRIDGE_MRP_RING_STATE]	= { .type = NLA_NESTED },
 	[IFLA_BRIDGE_MRP_RING_ROLE]	= { .type = NLA_NESTED },
 	[IFLA_BRIDGE_MRP_START_TEST]	= { .type = NLA_NESTED },
+	[IFLA_BRIDGE_MRP_CLEAR]		= { .type = NLA_NESTED },
 };
 
 static const struct nla_policy
@@ -235,6 +236,25 @@ static int br_mrp_start_test_parse(struct net_bridge *br,
struct nlattr *attr,
 	return br_mrp_start_test(br, &test);
 }
 
+static const struct nla_policy
+br_mrp_clear_policy[IFLA_BRIDGE_MRP_CLEAR_MAX + 1] = {
+	[IFLA_BRIDGE_MRP_CLEAR_UNSPEC]		= { .type = NLA_REJECT },
+};
+
+static int br_mrp_clear_parse(struct net_bridge *br, struct nlattr *attr,
+			      struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[IFLA_BRIDGE_MRP_START_TEST_MAX + 1];
+	int err;
+
+	err = nla_parse_nested(tb, IFLA_BRIDGE_MRP_CLEAR_MAX, attr,
+			       br_mrp_clear_policy, extack);
+	if (err)
+		return err;
+
+	return br_mrp_clear(br);
+}
+
 int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
 		 struct nlattr *attr, int cmd, struct netlink_ext_ack *extack)
 {
@@ -301,6 +321,12 @@ int br_mrp_parse(struct net_bridge *br, struct
net_bridge_port *p,
 			return err;
 	}
 
+	if (tb[IFLA_BRIDGE_MRP_CLEAR]) {
+		err = br_mrp_clear_parse(br, tb[IFLA_BRIDGE_MRP_CLEAR], extack);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
diff --git a/net/bridge/br_private_mrp.h b/net/bridge/br_private_mrp.h
index 33b255e38ffec..25c3b8596c25b 100644
--- a/net/bridge/br_private_mrp.h
+++ b/net/bridge/br_private_mrp.h
@@ -36,6 +36,7 @@ struct br_mrp {
 /* br_mrp.c */
 int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance);
 int br_mrp_del(struct net_bridge *br, struct br_mrp_instance *instance);
+int br_mrp_clear(struct net_bridge *br);
 int br_mrp_set_port_state(struct net_bridge_port *p,
 			  enum br_mrp_port_state_type state);
 int br_mrp_set_port_role(struct net_bridge_port *p,
-- 
2.26.2

Nikolay Aleksandrov

2020-Jun-24 08:19 UTC

head link

[Bridge] [PATCH net-next] bridge: mrp: Extend MRP netlink interface with IFLA_BRIDGE_MRP_CLEAR

On 24/06/2020 11:05, Horatiu Vultur wrote:> In case the userspace daemon dies, then when is restarted it doesn't
> know if there are any MRP instances in the kernel. Therefore extend the
> netlink interface to allow the daemon to clear all MRP instances when is
> started.
> 
> Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
> ---
>  include/uapi/linux/if_bridge.h |  8 ++++++++
>  net/bridge/br_mrp.c            | 15 +++++++++++++++
>  net/bridge/br_mrp_netlink.c    | 26 ++++++++++++++++++++++++++
>  net/bridge/br_private_mrp.h    |  1 +
>  4 files changed, 50 insertions(+)
> 
> diff --git a/include/uapi/linux/if_bridge.h
b/include/uapi/linux/if_bridge.h
> index caa6914a3e53a..2ae7d0c0d46b8 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_CLEAR,
>  	__IFLA_BRIDGE_MRP_MAX,
>  };
>  
> @@ -228,6 +229,13 @@ enum {
>  
>  #define IFLA_BRIDGE_MRP_START_TEST_MAX (__IFLA_BRIDGE_MRP_START_TEST_MAX -
1)
>  
> +enum {
> +	IFLA_BRIDGE_MRP_CLEAR_UNSPEC,
> +	__IFLA_BRIDGE_MRP_CLEAR_MAX,
> +};
Out of curiousity - do you plan to have any clean attributes?
In case you don't this can simply be a flag that clears the MRP instances
instead
of a nested attribute.
> +
> +#define IFLA_BRIDGE_MRP_CLEAR_MAX (__IFLA_BRIDGE_MRP_CLEAR_MAX - 1)
> +
>  struct br_mrp_instance {
>  	__u32 ring_id;
>  	__u32 p_ifindex;
> diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
> index 24986ec7d38cc..02d102edaaaad 100644
> --- a/net/bridge/br_mrp.c
> +++ b/net/bridge/br_mrp.c
> @@ -372,6 +372,21 @@ int br_mrp_del(struct net_bridge *br, struct
br_mrp_instance *instance)
>  	return 0;
>  }
>  
> +/* Deletes all MRP instances on the bridge
> + * note: called under rtnl_lock
> + */
> +int br_mrp_clear(struct net_bridge *br)
> +{
> +	struct br_mrp *mrp;
> +
> +	list_for_each_entry_rcu(mrp, &br->mrp_list, list,
> +				lockdep_rtnl_is_held()) {
> +		br_mrp_del_impl(br, mrp);
I don't think you're in RCU-protected region here, as the lockdep above
confirms, which
means br_mrp_del_impl() can free mrp and you can access freed memory while
walking the list
(trying to access of the next element).

You should be using list_for_each_entry_safe() to delete elements while walking
the list.

Cheers,
 Nik
> +	}
> +
> +	return 0;
> +}
> +
>  /* Set port state, port state can be forwarding, blocked or disabled
>   * note: already called with rtnl_lock
>   */
> diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
> index 34b3a8776991f..5e743538464f6 100644
> --- a/net/bridge/br_mrp_netlink.c
> +++ b/net/bridge/br_mrp_netlink.c
> @@ -14,6 +14,7 @@ static const struct nla_policy
br_mrp_policy[IFLA_BRIDGE_MRP_MAX + 1] = {
>  	[IFLA_BRIDGE_MRP_RING_STATE]	= { .type = NLA_NESTED },
>  	[IFLA_BRIDGE_MRP_RING_ROLE]	= { .type = NLA_NESTED },
>  	[IFLA_BRIDGE_MRP_START_TEST]	= { .type = NLA_NESTED },
> +	[IFLA_BRIDGE_MRP_CLEAR]		= { .type = NLA_NESTED },
>  };
>  
>  static const struct nla_policy
> @@ -235,6 +236,25 @@ static int br_mrp_start_test_parse(struct net_bridge
*br, struct nlattr *attr,
>  	return br_mrp_start_test(br, &test);
>  }
>  
> +static const struct nla_policy
> +br_mrp_clear_policy[IFLA_BRIDGE_MRP_CLEAR_MAX + 1] = {
> +	[IFLA_BRIDGE_MRP_CLEAR_UNSPEC]		= { .type = NLA_REJECT },
> +};
> +
> +static int br_mrp_clear_parse(struct net_bridge *br, struct nlattr *attr,
> +			      struct netlink_ext_ack *extack)
> +{
> +	struct nlattr *tb[IFLA_BRIDGE_MRP_START_TEST_MAX + 1];
> +	int err;
> +
> +	err = nla_parse_nested(tb, IFLA_BRIDGE_MRP_CLEAR_MAX, attr,
> +			       br_mrp_clear_policy, extack);
> +	if (err)
> +		return err;
> +
> +	return br_mrp_clear(br);
> +}
> +
>  int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
>  		 struct nlattr *attr, int cmd, struct netlink_ext_ack *extack)
>  {
> @@ -301,6 +321,12 @@ int br_mrp_parse(struct net_bridge *br, struct
net_bridge_port *p,
>  			return err;
>  	}
>  
> +	if (tb[IFLA_BRIDGE_MRP_CLEAR]) {
> +		err = br_mrp_clear_parse(br, tb[IFLA_BRIDGE_MRP_CLEAR], extack);
> +		if (err)
> +			return err;
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/net/bridge/br_private_mrp.h b/net/bridge/br_private_mrp.h
> index 33b255e38ffec..25c3b8596c25b 100644
> --- a/net/bridge/br_private_mrp.h
> +++ b/net/bridge/br_private_mrp.h
> @@ -36,6 +36,7 @@ struct br_mrp {
>  /* br_mrp.c */
>  int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance);
>  int br_mrp_del(struct net_bridge *br, struct br_mrp_instance *instance);
> +int br_mrp_clear(struct net_bridge *br);
>  int br_mrp_set_port_state(struct net_bridge_port *p,
>  			  enum br_mrp_port_state_type state);
>  int br_mrp_set_port_role(struct net_bridge_port *p,
>

Linux Ethernet Bridging - Jun 2020 - [Bridge] [PATCH net-next] bridge: mrp: Extend MRP netlink interface with IFLA_BRIDGE_MRP_CLEAR

[Bridge] [PATCH net-next] bridge: mrp: Extend MRP netlink interface with IFLA_BRIDGE_MRP_CLEAR

[Bridge] [PATCH net-next] bridge: mrp: Extend MRP netlink interface with IFLA_BRIDGE_MRP_CLEAR