[PATCH net-next] bonding: print churn state via netlink

[PATCH net-next] bonding: print churn state via netlink

[Hangbin Liu]

Currently, the churn state is printed only in sysfs. Add netlink support
so users could get the state via netlink.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 drivers/net/bonding/bond_netlink.c | 9 +++++++++
 include/uapi/linux/if_link.h       | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index 286f11c517f7..ea1a80e658ae 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -29,6 +29,8 @@ static size_t bond_get_slave_size(const struct net_device *bond_dev,
 		nla_total_size(sizeof(u16)) +	/* IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE */
 		nla_total_size(sizeof(s32)) +	/* IFLA_BOND_SLAVE_PRIO */
 		nla_total_size(sizeof(u16)) +	/* IFLA_BOND_SLAVE_ACTOR_PORT_PRIO */
+		nla_total_size(sizeof(u8)) +	/* IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE */
+		nla_total_size(sizeof(u8)) +	/* IFLA_BOND_SLAVE_AD_CHURN_PARTNER_STATE */
 		0;
 }
 
@@ -77,6 +79,13 @@ static int bond_fill_slave_info(struct sk_buff *skb,
 					IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE,
 					ad_port->partner_oper.port_state))
 				goto nla_put_failure;
+
+			if (nla_put_u8(skb, IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE,
+				       ad_port->sm_churn_actor_state))
+				goto nla_put_failure;
+			if (nla_put_u8(skb, IFLA_BOND_SLAVE_AD_CHURN_PARTNER_STATE,
+				       ad_port->sm_churn_partner_state))
+				goto nla_put_failure;
 		}
 
 		if (nla_put_u16(skb, IFLA_BOND_SLAVE_ACTOR_PORT_PRIO,
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index e9b5f79e1ee1..83a96c56b8ca 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -1568,6 +1568,8 @@ enum {
 	IFLA_BOND_SLAVE_AD_PARTNER_OPER_PORT_STATE,
 	IFLA_BOND_SLAVE_PRIO,
 	IFLA_BOND_SLAVE_ACTOR_PORT_PRIO,
+	IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE,
+	IFLA_BOND_SLAVE_AD_CHURN_PARTNER_STATE,
 	__IFLA_BOND_SLAVE_MAX,
 };
 
-- 
2.50.1

[PATCH iproute2-next] iplink: bond_slave: print actor and partner churn state

[Hangbin Liu]

Add ability to print both actor and partner port churn states
(MONITOR/CHURN/NO_CHURN) via netlink attributes. This provides
visibility into the LACP churn detection state for bond slaves.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 ip/iplink_bond_slave.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/ip/iplink_bond_slave.c b/ip/iplink_bond_slave.c
index c88100e248dd..5dfe2970941e 100644
--- a/ip/iplink_bond_slave.c
+++ b/ip/iplink_bond_slave.c
@@ -86,6 +86,12 @@ static void print_slave_oper_state(FILE *fp, const char *name, __u16 state)
 	close_json_array(PRINT_ANY, "> ");
 }
 
+static const char *port_churn_state[] = {
+	"MONITOR",
+	"CHURN",
+	"NO_CHURN",
+};
+
 static void bond_slave_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 {
 	SPRINT_BUF(b1);
@@ -148,6 +154,26 @@ static void bond_slave_print_opt(struct link_util *lu, FILE *f, struct rtattr *t
 		print_slave_oper_state(f, "ad_partner_oper_port_state_str", state);
 	}
 
+	if (tb[IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE]) {
+		__u8 state = rta_getattr_u8(tb[IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE]);
+
+		if (state >= ARRAY_SIZE(port_churn_state))
+			print_int(PRINT_ANY, "churn_actor_state", "churn_actor_state %u ", state);
+		else
+			print_string(PRINT_ANY, "churn_actor_state", "churn_actor_state %s ",
+				     port_churn_state[state]);
+	}
+
+	if (tb[IFLA_BOND_SLAVE_AD_CHURN_PARTNER_STATE]) {
+		__u8 state = rta_getattr_u8(tb[IFLA_BOND_SLAVE_AD_CHURN_PARTNER_STATE]);
+
+		if (state >= ARRAY_SIZE(port_churn_state))
+			print_int(PRINT_ANY, "churn_partner_state", "churn_partner_state %u ", state);
+		else
+			print_string(PRINT_ANY, "churn_partner_state", "churn_partner_state %s ",
+				     port_churn_state[state]);
+	}
+
 	if (tb[IFLA_BOND_SLAVE_ACTOR_PORT_PRIO])
 		print_int(PRINT_ANY,
 			  "actor_port_prio",
-- 
2.50.1

Re: [PATCH iproute2-next] iplink: bond_slave: print actor and partner churn state

[Stephen Hemminger]

On Tue, 24 Feb 2026 02:02:15 +0000
Hangbin Liu <liuhangbin@gmail.com> wrote:

> +	if (tb[IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE]) {
> +		__u8 state = rta_getattr_u8(tb[IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE]);
> +
> +		if (state >= ARRAY_SIZE(port_churn_state))
> +			print_int(PRINT_ANY, "churn_actor_state", "churn_actor_state %u ", state);

You should use print_uint for unsigned values.

Re: [PATCH iproute2-next] iplink: bond_slave: print actor and partner churn state

[Hangbin Liu]

On Wed, Feb 25, 2026 at 01:22:39PM -0800, Stephen Hemminger wrote:
> On Tue, 24 Feb 2026 02:02:15 +0000
> Hangbin Liu <liuhangbin@gmail.com> wrote:
> 
> > +	if (tb[IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE]) {
> > +		__u8 state = rta_getattr_u8(tb[IFLA_BOND_SLAVE_AD_CHURN_ACTOR_STATE]);
> > +
> > +		if (state >= ARRAY_SIZE(port_churn_state))
> > +			print_int(PRINT_ANY, "churn_actor_state", "churn_actor_state %u ", state);
> 
> You should use print_uint for unsigned values.

Thanks, should I post a v2 version for both the kernel and iproute2 patches,
Or just the iproute2 patch?

Hangbin

Re: [PATCH iproute2-next] iplink: bond_slave: print actor and partner churn state

[Jakub Kicinski]

On Thu, 26 Feb 2026 02:10:21 +0000 Hangbin Liu wrote:
> > You should use print_uint for unsigned values.  
> 
> Thanks, should I post a v2 version for both the kernel and iproute2 patches,
> Or just the iproute2 patch?

Just iproute2, they aren't bundled by patchwork (please refer to 
the netdev maintainer faq for the correct way to co-post iproute2)

Re: [PATCH iproute2-next] iplink: bond_slave: print actor and partner churn state

[Hangbin Liu]

On Wed, Feb 25, 2026 at 07:03:33PM -0800, Jakub Kicinski wrote:
> On Thu, 26 Feb 2026 02:10:21 +0000 Hangbin Liu wrote:
> > > You should use print_uint for unsigned values.  
> > 
> > Thanks, should I post a v2 version for both the kernel and iproute2 patches,
> > Or just the iproute2 patch?
> 
> Just iproute2, they aren't bundled by patchwork (please refer to 
> the netdev maintainer faq for the correct way to co-post iproute2)

Got it. I will post the iproute2 as a new series.

Re: [PATCH net-next] bonding: print churn state via netlink

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Tue, 24 Feb 2026 02:02:14 +0000 you wrote:
> Currently, the churn state is printed only in sysfs. Add netlink support
> so users could get the state via netlink.
> 
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  drivers/net/bonding/bond_netlink.c | 9 +++++++++
>  include/uapi/linux/if_link.h       | 2 ++
>  2 files changed, 11 insertions(+)

Here is the summary with links:
  - [net-next] bonding: print churn state via netlink
    https://git.kernel.org/netdev/net-next/c/4916f2e2f3fc

You are awesome, thank you!
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