[B.A.T.M.A.N.] [RFC v2 18/19] batman-adv: Add throughput_override hardif genl configuration

[Sven Eckelmann <sven@narfation.org>]

The B.A.T.M.A.N. V implementation tries to estimate the link throughput of
an interface to an originator using different automatic methods. It is
still possible to overwrite it the link throughput for all reachable
originators via this interface.

The BATADV_CMD_SET_HARDIF/BATADV_CMD_GET_HARDIF commands allow to set/get
the configuration of this feature using the u32
BATADV_ATTR_THROUGHPUT_OVERRIDE attribute. The used unit is in 100 Kbit/s.
If the value is set to 0 then batman-adv will try to estimate the
throughput by itself.

Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 include/uapi/linux/batman_adv.h |  8 ++++++++
 net/batman-adv/netlink.c        | 12 ++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index a4ab6bda..49ab118e 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -481,6 +481,14 @@ enum batadv_nl_attrs {
 	 */
 	BATADV_ATTR_ELP_INTERVAL,
 
+	/**
+	 * @BATADV_ATTR_THROUGHPUT_OVERRIDE: defines the throughput value to be
+	 *  used by B.A.T.M.A.N. V when estimating the link throughput using
+	 *  this interface. If the value is set to 0 then batman-adv will try to
+	 *  estimate the throughput by itself.
+	 */
+	BATADV_ATTR_THROUGHPUT_OVERRIDE,
+
 	/* add attributes above here, update the policy in netlink.c */
 
 	/**
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 70ab010e..970490a4 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -160,6 +160,7 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
 	[BATADV_ATTR_NETWORK_CODING]		= { .type = NLA_U8 },
 	[BATADV_ATTR_ORIG_INTERVAL]		= { .type = NLA_U32 },
 	[BATADV_ATTR_ELP_INTERVAL]		= { .type = NLA_U32 },
+	[BATADV_ATTR_THROUGHPUT_OVERRIDE]	= { .type = NLA_U32 },
 };
 
 /**
@@ -828,6 +829,10 @@ static int batadv_netlink_hardif_put(struct sk_buff *msg,
 	if (nla_put_u32(msg, BATADV_ATTR_ELP_INTERVAL,
 			atomic_read(&hard_iface->bat_v.elp_interval)))
 		goto nla_put_failure;
+
+	if (nla_put_u32(msg, BATADV_ATTR_THROUGHPUT_OVERRIDE,
+			atomic_read(&hard_iface->bat_v.throughput_override)))
+		goto nla_put_failure;
 #endif /* CONFIG_BATMAN_ADV_BATMAN_V */
 
 	genlmsg_end(msg, hdr);
@@ -923,6 +928,13 @@ static int batadv_netlink_set_hardif(struct sk_buff *skb,
 
 		atomic_set(&hard_iface->bat_v.elp_interval, nla_get_u32(attr));
 	}
+
+	if (info->attrs[BATADV_ATTR_THROUGHPUT_OVERRIDE]) {
+		attr = info->attrs[BATADV_ATTR_THROUGHPUT_OVERRIDE];
+
+		atomic_set(&hard_iface->bat_v.throughput_override,
+			   nla_get_u32(attr));
+	}
 #endif /* CONFIG_BATMAN_ADV_BATMAN_V */
 
 	batadv_netlink_notify_hardif(bat_priv, hard_iface);
-- 
2.19.1