batman-adv: ELP - send unicast ELP packets for throughput sampling (8d2d499e) · Commits · 戴 / test

net/batman-adv/bat_v_elp.c

+69 −0

Original line number	Diff line number	Diff line
		@@ -164,6 +164,69 @@ void batadv_v_elp_throughput_metric_update(struct work_struct *work)
		batadv_hardif_neigh_put(neigh);
		}

		/**
		* batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
		* @neigh: the neighbour to probe
		*
		* Sends a predefined number of unicast wifi packets to a given neighbour in
		* order to trigger the throughput estimation on this link by the RC algorithm.
		* Packets are sent only if there there is not enough payload unicast traffic
		* towards this neighbour..
		*
		* Return: True on success and false in case of error during skb preparation.
		*/
		static bool
		batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
		{
		struct batadv_hard_iface *hard_iface = neigh->if_incoming;
		struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
		unsigned long last_tx_diff;
		struct sk_buff *skb;
		int probe_len, i;
		int elp_skb_len;

		/* this probing routine is for Wifi neighbours only */
		if (!batadv_is_wifi_netdev(hard_iface->net_dev))
		return true;

		/* probe the neighbor only if no unicast packets have been sent
		* to it in the last 100 milliseconds: this is the rate control
		* algorithm sampling interval (minstrel). In this way, if not
		* enough traffic has been sent to the neighbor, batman-adv can
		* generate 2 probe packets and push the RC algorithm to perform
		* the sampling
		*/
		last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
		if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
		return true;

		probe_len = max_t(int, sizeof(struct batadv_elp_packet),
		BATADV_ELP_MIN_PROBE_SIZE);

		for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
		elp_skb_len = hard_iface->bat_v.elp_skb->len;
		skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
		probe_len - elp_skb_len,
		GFP_ATOMIC);
		if (!skb)
		return false;

		/* Tell the skb to get as big as the allocated space (we want
		* the packet to be exactly of that size to make the link
		* throughput estimation effective.
		*/
		skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);

		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		"Sending unicast (probe) ELP packet on interface %s to %pM\n",
		hard_iface->net_dev->name, neigh->addr);

		batadv_send_skb_packet(skb, hard_iface, neigh->addr);
		}

		return true;
		}

		/**
		* batadv_v_elp_periodic_work - ELP periodic task per interface
		* @work: work queue item
		@@ -227,6 +290,12 @@ static void batadv_v_elp_periodic_work(struct work_struct *work)
		*/
		rcu_read_lock();
		hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
		if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
		/* if something goes wrong while probing, better to stop
		* sending packets immediately and reschedule the task
		*/
		break;

		if (!kref_get_unless_zero(&hardif_neigh->refcount))
		continue;

net/batman-adv/main.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -63,6 +63,9 @@

		/* B.A.T.M.A.N. V */
		#define BATADV_THROUGHPUT_DEFAULT_VALUE 10 /* 1 Mbps */
		#define BATADV_ELP_PROBES_PER_NODE 2
		#define BATADV_ELP_MIN_PROBE_SIZE 200 /* bytes */
		#define BATADV_ELP_PROBE_MAX_TX_DIFF 100 /* milliseconds */
		#define BATADV_ELP_MAX_AGE 64
		#define BATADV_OGM_MAX_ORIGDIFF 5
		#define BATADV_OGM_MAX_AGE 64

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