net: nexthop: Add ability to enable / disable hardware statistics

JIRA: https://issues.redhat.com/browse/RHEL-59118

commit 746c19a
Author: Ido Schimmel <idosch@nvidia.com>
Date:   Wed Mar 6 13:49:20 2024 +0100

    net: nexthop: Add ability to enable / disable hardware statistics

    Add netlink support for enabling collection of HW statistics on nexthop
    groups.

    Signed-off-by: Ido Schimmel <idosch@nvidia.com>
    Reviewed-by: David Ahern <dsahern@kernel.org>
    Signed-off-by: Petr Machata <petrm@nvidia.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Ivan Vecera <ivecera@redhat.com>

Author: ivecera

include/net/nexthop.h

@@ -49,6 +49,8 @@ struct nh_config {
 	bool		nh_grp_res_has_idle_timer;
 	bool		nh_grp_res_has_unbalanced_timer;
 
+	bool		nh_hw_stats;
+
 	struct nlattr	*nh_encap;
 	u16		nh_encap_type;
 

include/uapi/linux/nexthop.h

@@ -68,6 +68,9 @@ enum {
 	/* nested; nexthop group stats */
 	NHA_GROUP_STATS,
 
+	/* u32; nexthop hardware stats enable */
+	NHA_HW_STATS_ENABLE,
+
 	__NHA_MAX,
 };
 

net/ipv4/nexthop.c

@@ -39,6 +39,7 @@ static const struct nla_policy rtm_nh_policy_new[] = {
 	[NHA_ENCAP]		= { .type = NLA_NESTED },
 	[NHA_FDB]		= { .type = NLA_FLAG },
 	[NHA_RES_GROUP]		= { .type = NLA_NESTED },
+	[NHA_HW_STATS_ENABLE]	= NLA_POLICY_MAX(NLA_U32, true),
 };
 
 static const struct nla_policy rtm_nh_policy_get[] = {
@@ -778,7 +779,8 @@ static int nla_put_nh_group(struct sk_buff *skb, struct nexthop *nh,
 		goto nla_put_failure;
 
 	if (op_flags & NHA_OP_FLAG_DUMP_STATS &&
-	    nla_put_nh_group_stats(skb, nh))
+	    (nla_put_u32(skb, NHA_HW_STATS_ENABLE, nhg->hw_stats) ||
+	     nla_put_nh_group_stats(skb, nh)))
 		goto nla_put_failure;
 
 	return 0;
@@ -1202,6 +1204,7 @@ static int nh_check_attr_group(struct net *net,
 		if (!tb[i])
 			continue;
 		switch (i) {
+		case NHA_HW_STATS_ENABLE:
 		case NHA_FDB:
 			continue;
 		case NHA_RES_GROUP:
@@ -2622,6 +2625,9 @@ static struct nexthop *nexthop_create_group(struct net *net,
 	if (cfg->nh_fdb)
 		nhg->fdb_nh = 1;
 
+	if (cfg->nh_hw_stats)
+		nhg->hw_stats = true;
+
 	rcu_assign_pointer(nh->nh_grp, nhg);
 
 	return nh;
@@ -2962,6 +2968,9 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
 			err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP],
 						       cfg, extack);
 
+		if (tb[NHA_HW_STATS_ENABLE])
+			cfg->nh_hw_stats = nla_get_u32(tb[NHA_HW_STATS_ENABLE]);
+
 		/* no other attributes should be set */
 		goto out;
 	}
@@ -3053,6 +3062,10 @@ static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
 		goto out;
 	}
 
+	if (tb[NHA_HW_STATS_ENABLE]) {
+		NL_SET_ERR_MSG(extack, "Cannot enable nexthop hardware statistics for non-group nexthops");
+		goto out;
+	}
 
 	err = 0;
 out: