In some setups multiple hard interfaces with similar link qualities
or throughput values are available. But people have expressed the desire
to consider one of them as a backup only.
Some creative solutions are currently in use: Such people are
configuring multiple batman-adv mesh/soft interfaces, wire them
together with some veth pairs and then tune the hop penalty to achieve
an effect similar to a tunable per interface hop penalty.
This patch introduces a new, configurable, per hard interface hop penalty
to simplify such setups.
Signed-off-by: Linus Lüssing <linus.luess...@c0d3.blue>
---
include/uapi/linux/batman_adv.h | 3 ++-
net/batman-adv/bat_iv_ogm.c | 17 +++++++++--------
net/batman-adv/bat_v_ogm.c | 13 ++++++++++---
net/batman-adv/hard-interface.c | 2 ++
net/batman-adv/netlink.c | 14 ++++++++++++--
net/batman-adv/types.h | 6 ++++++
6 files changed, 41 insertions(+), 14 deletions(-)
diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index 617c180f..dac57936 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -427,7 +427,8 @@ enum batadv_nl_attrs {
/**
* @BATADV_ATTR_HOP_PENALTY: defines the penalty which will be applied
- * to an originator message's tq-field on every hop.
+ * to an originator message's tq-field on every hop and/or per
+ * hard interface
*/
BATADV_ATTR_HOP_PENALTY,
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index e87f19c8..5f7a5c04 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1075,10 +1075,10 @@ static bool batadv_iv_ogm_calc_tq(struct
batadv_orig_node *orig_node,
struct batadv_neigh_ifinfo *neigh_ifinfo;
u8 total_count;
u8 orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
+ unsigned int tq_iface_hop_penalty = BATADV_TQ_MAX_VALUE;
unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
unsigned int tq_asym_penalty, inv_asym_penalty;
unsigned int combined_tq;
- unsigned int tq_iface_penalty;
bool ret = false;
/* find corresponding one hop neighbor */
@@ -1157,31 +1157,32 @@ static bool batadv_iv_ogm_calc_tq(struct
batadv_orig_node *orig_node,
inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
inv_asym_penalty /= neigh_rq_max_cube;
tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
+ tq_iface_hop_penalty -= atomic_read(&if_incoming->hop_penalty);
/* penalize if the OGM is forwarded on the same interface. WiFi
* interfaces and other half duplex devices suffer from throughput
* drops as they can't send and receive at the same time.
*/
- tq_iface_penalty = BATADV_TQ_MAX_VALUE;
if (if_outgoing && if_incoming == if_outgoing &&
batadv_is_wifi_hardif(if_outgoing))
- tq_iface_penalty = batadv_hop_penalty(BATADV_TQ_MAX_VALUE,
- bat_priv);
+ tq_iface_hop_penalty = batadv_hop_penalty(tq_iface_hop_penalty,
+ bat_priv);
combined_tq = batadv_ogm_packet->tq *
tq_own *
tq_asym_penalty *
- tq_iface_penalty;
+ tq_iface_hop_penalty;
combined_tq /= BATADV_TQ_MAX_VALUE *
BATADV_TQ_MAX_VALUE *
BATADV_TQ_MAX_VALUE;
batadv_ogm_packet->tq = combined_tq;
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
- "bidirectional: orig = %pM neigh = %pM => own_bcast = %2i,
real recv = %2i, local tq: %3i, asym_penalty: %3i, iface_penalty: %3i, total
tq: %3i, if_incoming = %s, if_outgoing = %s\n",
+ "bidirectional: orig = %pM neigh = %pM => own_bcast = %2i,
real recv = %2i, local tq: %3i, asym_penalty: %3i, iface_hop_penalty: %3i,
total tq: %3i, if_incoming = %s, if_outgoing = %s\n",
orig_node->orig, orig_neigh_node->orig, total_count,
- neigh_rq_count, tq_own, tq_asym_penalty, tq_iface_penalty,
- batadv_ogm_packet->tq, if_incoming->net_dev->name,
+ neigh_rq_count, tq_own, tq_asym_penalty,
+ tq_iface_hop_penalty, batadv_ogm_packet->tq,
+ if_incoming->net_dev->name,
if_outgoing ? if_outgoing->net_dev->name : "DEFAULT");
/* if link has the minimum required transmission quality
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index 18028b9f..1e84ab99 100644
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -455,15 +455,17 @@ void batadv_v_ogm_primary_iface_set(struct
batadv_hard_iface *primary_iface)
* @throughput: the current throughput
*
* Apply a penalty on the current throughput metric value based on the
- * characteristic of the interface where the OGM has been received. The return
- * value is computed as follows:
+ * characteristic of the interface where the OGM has been received.
+ *
+ * Initially the per hardif hop penalty is applied to the throughput. After
+ * that the return value is then computed as follows:
* - throughput * 50% if the incoming and outgoing interface are the
* same WiFi interface and the throughput is above
* 1MBit/s
* - throughput if the outgoing interface is the default
* interface (i.e. this OGM is processed for the
* internal table and not forwarded)
- * - throughput * hop penalty otherwise
+ * - throughput * node hop penalty otherwise
*
* Return: the penalised throughput metric.
*/
@@ -472,9 +474,14 @@ static u32 batadv_v_forward_penalty(struct batadv_priv
*bat_priv,
struct batadv_hard_iface *if_outgoing,
u32 throughput)
{
+ int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
int hop_penalty = atomic_read(&bat_priv->hop_penalty);
int hop_penalty_max = BATADV_TQ_MAX_VALUE;
+ /* Apply per hardif hop penalty */
+ throughput = throughput * (hop_penalty_max - if_hop_penalty) /
+ hop_penalty_max;
+
/* Don't apply hop penalty in default originator table. */
if (if_outgoing == BATADV_IF_DEFAULT)
return throughput;
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 3a256af9..f8495ff2 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -939,6 +939,8 @@ batadv_hardif_add_interface(struct net_device *net_dev)
if (batadv_is_wifi_hardif(hard_iface))
hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
+ atomic_set(&hard_iface->hop_penalty, 0);
+
batadv_v_hardif_init(hard_iface);
batadv_check_known_mac_addr(hard_iface->net_dev);
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 02ed073f..d4bfc4c5 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -826,6 +826,10 @@ static int batadv_netlink_hardif_fill(struct sk_buff *msg,
goto nla_put_failure;
}
+ if (nla_put_u8(msg, BATADV_ATTR_HOP_PENALTY,
+ atomic_read(&hard_iface->hop_penalty)))
+ goto nla_put_failure;
+
#ifdef CONFIG_BATMAN_ADV_BATMAN_V
if (nla_put_u32(msg, BATADV_ATTR_ELP_INTERVAL,
atomic_read(&hard_iface->bat_v.elp_interval)))
@@ -920,10 +924,16 @@ static int batadv_netlink_set_hardif(struct sk_buff *skb,
{
struct batadv_hard_iface *hard_iface = info->user_ptr[1];
struct batadv_priv *bat_priv = info->user_ptr[0];
-
-#ifdef CONFIG_BATMAN_ADV_BATMAN_V
struct nlattr *attr;
+ if (info->attrs[BATADV_ATTR_HOP_PENALTY]) {
+ attr = info->attrs[BATADV_ATTR_HOP_PENALTY];
+
+ atomic_set(&hard_iface->hop_penalty, nla_get_u8(attr));
+ }
+
+#ifdef CONFIG_BATMAN_ADV_BATMAN_V
+
if (info->attrs[BATADV_ATTR_ELP_INTERVAL]) {
attr = info->attrs[BATADV_ATTR_ELP_INTERVAL];
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index d152b8e8..f7b52426 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -208,6 +208,12 @@ struct batadv_hard_iface {
/** @rcu: struct used for freeing in an RCU-safe manner */
struct rcu_head rcu;
+ /**
+ * @hop_penalty: penalty which will be applied to the tq-field
+ * of an OGM received via this interface
+ */
+ atomic_t hop_penalty;
+
/** @bat_iv: per hard-interface B.A.T.M.A.N. IV data */
struct batadv_hard_iface_bat_iv bat_iv;
--
2.27.0.rc2
