batman-adv: Introduce a configurable per interface hop penalty

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.

Linus Lüssing committed 6 years ago

Commit 3bda14d1 parent bccb48c6 files · +40 −13Browse files

Unified · Split

6 files

include/uapi/linux/batman_adv.h +2 −1
net/batman-adv/bat_iv_ogm.c +9 −8
net/batman-adv/bat_v_ogm.c +10 −3
net/batman-adv/hard-interface.c +2 −0
net/batman-adv/netlink.c +11 −1
net/batman-adv/types.h +6 −0

include/uapi/linux/batman_adv.h+2−1

@@ -427,7 +427,8 @@ enum batadv_nl_attrs { · 426 unmodified lines
427	427
428	428	/**
429	429	* @BATADV_ATTR_HOP_PENALTY: defines the penalty which will be applied
430		− * to an originator message's tq-field on every hop.
	430	+ * to an originator message's tq-field on every hop and/or per
	431	+ * hard interface
431	432	*/
432	433	BATADV_ATTR_HOP_PENALTY,
433	434

net/batman-adv/bat_iv_ogm.c+9−8

@@ -1075,10 +1075,10 @@ static bool batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node, · 1074 unmodified lines
1075	1075	struct batadv_neigh_ifinfo *neigh_ifinfo;
1076	1076	u8 total_count;
1077	1077	u8 orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
	1078	+ unsigned int tq_iface_hop_penalty = BATADV_TQ_MAX_VALUE;
1078	1079	unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
1079	1080	unsigned int tq_asym_penalty, inv_asym_penalty;
1080	1081	unsigned int combined_tq;
1081		− unsigned int tq_iface_penalty;
1082	1082	bool ret = false;
1083	1083
1084	1084	/* find corresponding one hop neighbor */
@@ -1157,31 +1157,32 @@ static bool batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node, · 72 unmodified lines
1157	1157	inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
1158	1158	inv_asym_penalty /= neigh_rq_max_cube;
1159	1159	tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
	1160	+ tq_iface_hop_penalty -= atomic_read(&if_incoming->hop_penalty);
1160	1161
1161	1162	/* penalize if the OGM is forwarded on the same interface. WiFi
1162	1163	* interfaces and other half duplex devices suffer from throughput
1163	1164	* drops as they can't send and receive at the same time.
1164	1165	*/
1165		− tq_iface_penalty = BATADV_TQ_MAX_VALUE;
1166	1166	if (if_outgoing && if_incoming == if_outgoing &&
1167	1167	batadv_is_wifi_hardif(if_outgoing))
1168		− tq_iface_penalty = batadv_hop_penalty(BATADV_TQ_MAX_VALUE,
1169		− bat_priv);
	1168	+ tq_iface_hop_penalty = batadv_hop_penalty(tq_iface_hop_penalty,
	1169	+ bat_priv);
1170	1170
1171	1171	combined_tq = batadv_ogm_packet->tq *
1172	1172	tq_own *
1173	1173	tq_asym_penalty *
1174		− tq_iface_penalty;
	1174	+ tq_iface_hop_penalty;
1175	1175	combined_tq /= BATADV_TQ_MAX_VALUE *
1176	1176	BATADV_TQ_MAX_VALUE *
1177	1177	BATADV_TQ_MAX_VALUE;
1178	1178	batadv_ogm_packet->tq = combined_tq;
1179	1179
1180	1180	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1181		− "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",
	1181	+ "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",
1182	1182	orig_node->orig, orig_neigh_node->orig, total_count,
1183		− neigh_rq_count, tq_own, tq_asym_penalty, tq_iface_penalty,
1184		− batadv_ogm_packet->tq, if_incoming->net_dev->name,
	1183	+ neigh_rq_count, tq_own, tq_asym_penalty,
	1184	+ tq_iface_hop_penalty, batadv_ogm_packet->tq,
	1185	+ if_incoming->net_dev->name,
1185	1186	if_outgoing ? if_outgoing->net_dev->name : "DEFAULT");
1186	1187
1187	1188	/* if link has the minimum required transmission quality

net/batman-adv/bat_v_ogm.c+10−3

@@ -455,15 +455,17 @@ unlock: · 454 unmodified lines
455	455	* @throughput: the current throughput
456	456	*
457	457	* Apply a penalty on the current throughput metric value based on the
458		− * characteristic of the interface where the OGM has been received. The return
459		− * value is computed as follows:
	458	+ * characteristic of the interface where the OGM has been received.
	459	+ *
	460	+ * Initially the per hardif hop penalty is applied to the throughput. After
	461	+ * that the return value is then computed as follows:
460	462	* - throughput * 50% if the incoming and outgoing interface are the
461	463	* same WiFi interface and the throughput is above
462	464	* 1MBit/s
463	465	* - throughput if the outgoing interface is the default
464	466	* interface (i.e. this OGM is processed for the
465	467	* internal table and not forwarded)
466		− * - throughput * hop penalty otherwise
	468	+ * - throughput * node hop penalty otherwise
467	469	*
468	470	* Return: the penalised throughput metric.
469	471	*/
@@ -472,9 +474,14 @@ static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, · 2 unmodified lines
472	474	struct batadv_hard_iface *if_outgoing,
473	475	u32 throughput)
474	476	{
	477	+ int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
475	478	int hop_penalty = atomic_read(&bat_priv->hop_penalty);
476	479	int hop_penalty_max = BATADV_TQ_MAX_VALUE;
477	480
	481	+ /* Apply per hardif hop penalty */
	482	+ throughput = throughput * (hop_penalty_max - if_hop_penalty) /
	483	+ hop_penalty_max;
	484	+
478	485	/* Don't apply hop penalty in default originator table. */
479	486	if (if_outgoing == BATADV_IF_DEFAULT)
480	487	return throughput;

net/batman-adv/hard-interface.c+2−0

@@ -939,6 +939,8 @@ batadv_hardif_add_interface(struct net_device *net_dev) · 938 unmodified lines
939	939	if (batadv_is_wifi_hardif(hard_iface))
940	940	hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
941	941
	942	+ atomic_set(&hard_iface->hop_penalty, 0);
	943	+
942	944	batadv_v_hardif_init(hard_iface);
943	945
944	946	batadv_check_known_mac_addr(hard_iface->net_dev);

net/batman-adv/netlink.c+11−1

@@ -826,6 +826,10 @@ static int batadv_netlink_hardif_fill(struct sk_buff *msg, · 825 unmodified lines
826	826	goto nla_put_failure;
827	827	}
828	828
	829	+ if (nla_put_u8(msg, BATADV_ATTR_HOP_PENALTY,
	830	+ atomic_read(&hard_iface->hop_penalty)))
	831	+ goto nla_put_failure;
	832	+
829	833	#ifdef CONFIG_BATMAN_ADV_BATMAN_V
830	834	if (nla_put_u32(msg, BATADV_ATTR_ELP_INTERVAL,
831	835	atomic_read(&hard_iface->bat_v.elp_interval)))
@@ -920,9 +924,15 @@ static int batadv_netlink_set_hardif(struct sk_buff *skb, · 88 unmodified lines
920	924	{
921	925	struct batadv_hard_iface *hard_iface = info->user_ptr[1];
922	926	struct batadv_priv *bat_priv = info->user_ptr[0];
	927	+ struct nlattr *attr;
	928	+
	929	+ if (info->attrs[BATADV_ATTR_HOP_PENALTY]) {
	930	+ attr = info->attrs[BATADV_ATTR_HOP_PENALTY];
	931	+
	932	+ atomic_set(&hard_iface->hop_penalty, nla_get_u8(attr));
	933	+ }
923	934
924	935	#ifdef CONFIG_BATMAN_ADV_BATMAN_V
925		− struct nlattr *attr;
926	936
927	937	if (info->attrs[BATADV_ATTR_ELP_INTERVAL]) {
928	938	attr = info->attrs[BATADV_ATTR_ELP_INTERVAL];

net/batman-adv/types.h+6−0

@@ -208,6 +208,12 @@ struct batadv_hard_iface { · 207 unmodified lines
208	208	/** @rcu: struct used for freeing in an RCU-safe manner */
209	209	struct rcu_head rcu;
210	210
	211	+ /**
	212	+ * @hop_penalty: penalty which will be applied to the tq-field
	213	+ * of an OGM received via this interface
	214	+ */
	215	+ atomic_t hop_penalty;
	216	+
211	217	/** @bat_iv: per hard-interface B.A.T.M.A.N. IV data */
212	218	struct batadv_hard_iface_bat_iv bat_iv;
213	219