Commit 50164d8f authored by Antonio Quartulli's avatar Antonio Quartulli Committed by Simon Wunderlich

batman-adv: B.A.T.M.A.N. V - implement GW selection logic

Since the GW selection logic has been made routing protocol specific
it is now possible for B.A.T.M.A.N V to have its own mechanism by
providing the API implementation.

Implement the GW specific API in the B.A.T.M.A.N. V protocol in
order to provide a working GW selection mechanism.
Signed-off-by: default avatarAntonio Quartulli <a@unstable.cc>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent 34d99cfe
......@@ -25,6 +25,7 @@
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
......@@ -40,6 +41,7 @@
#include "gateway_common.h"
#include "hard-interface.h"
#include "hash.h"
#include "log.h"
#include "originator.h"
#include "packet.h"
......@@ -350,6 +352,213 @@ static ssize_t batadv_v_show_sel_class(struct batadv_priv *bat_priv, char *buff)
return sprintf(buff, "%u.%u MBit\n", class / 10, class % 10);
}
/**
* batadv_v_gw_throughput_get - retrieve the GW-bandwidth for a given GW
* @gw_node: the GW to retrieve the metric for
* @bw: the pointer where the metric will be stored. The metric is computed as
* the minimum between the GW advertised throughput and the path throughput to
* it in the mesh
*
* Return: 0 on success, -1 on failure
*/
static int batadv_v_gw_throughput_get(struct batadv_gw_node *gw_node, u32 *bw)
{
struct batadv_neigh_ifinfo *router_ifinfo = NULL;
struct batadv_orig_node *orig_node;
struct batadv_neigh_node *router;
int ret = -1;
orig_node = gw_node->orig_node;
router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
if (!router)
goto out;
router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
if (!router_ifinfo)
goto out;
/* the GW metric is computed as the minimum between the path throughput
* to reach the GW itself and the advertised bandwidth.
* This gives us an approximation of the effective throughput that the
* client can expect via this particular GW node
*/
*bw = router_ifinfo->bat_v.throughput;
*bw = min_t(u32, *bw, gw_node->bandwidth_down);
ret = 0;
out:
if (router)
batadv_neigh_node_put(router);
if (router_ifinfo)
batadv_neigh_ifinfo_put(router_ifinfo);
return ret;
}
/**
* batadv_v_gw_get_best_gw_node - retrieve the best GW node
* @bat_priv: the bat priv with all the soft interface information
*
* Return: the GW node having the best GW-metric, NULL if no GW is known
*/
static struct batadv_gw_node *
batadv_v_gw_get_best_gw_node(struct batadv_priv *bat_priv)
{
struct batadv_gw_node *gw_node, *curr_gw = NULL;
u32 max_bw = 0, bw;
rcu_read_lock();
hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
if (!kref_get_unless_zero(&gw_node->refcount))
continue;
if (batadv_v_gw_throughput_get(gw_node, &bw) < 0)
goto next;
if (curr_gw && (bw <= max_bw))
goto next;
if (curr_gw)
batadv_gw_node_put(curr_gw);
curr_gw = gw_node;
kref_get(&curr_gw->refcount);
max_bw = bw;
next:
batadv_gw_node_put(gw_node);
}
rcu_read_unlock();
return curr_gw;
}
/**
* batadv_v_gw_is_eligible - check if a originator would be selected as GW
* @bat_priv: the bat priv with all the soft interface information
* @curr_gw_orig: originator representing the currently selected GW
* @orig_node: the originator representing the new candidate
*
* Return: true if orig_node can be selected as current GW, false otherwise
*/
static bool batadv_v_gw_is_eligible(struct batadv_priv *bat_priv,
struct batadv_orig_node *curr_gw_orig,
struct batadv_orig_node *orig_node)
{
struct batadv_gw_node *curr_gw = NULL, *orig_gw = NULL;
u32 gw_throughput, orig_throughput, threshold;
bool ret = false;
threshold = atomic_read(&bat_priv->gw.sel_class);
curr_gw = batadv_gw_node_get(bat_priv, curr_gw_orig);
if (!curr_gw) {
ret = true;
goto out;
}
if (batadv_v_gw_throughput_get(curr_gw, &gw_throughput) < 0) {
ret = true;
goto out;
}
orig_gw = batadv_gw_node_get(bat_priv, orig_node);
if (!orig_node)
goto out;
if (batadv_v_gw_throughput_get(orig_gw, &orig_throughput) < 0)
goto out;
if (orig_throughput < gw_throughput)
goto out;
if ((orig_throughput - gw_throughput) < threshold)
goto out;
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Restarting gateway selection: better gateway found (throughput curr: %u, throughput new: %u)\n",
gw_throughput, orig_throughput);
ret = true;
out:
if (curr_gw)
batadv_gw_node_put(curr_gw);
if (orig_gw)
batadv_gw_node_put(orig_gw);
return ret;
}
/* fails if orig_node has no router */
static int batadv_v_gw_write_buffer_text(struct batadv_priv *bat_priv,
struct seq_file *seq,
const struct batadv_gw_node *gw_node)
{
struct batadv_gw_node *curr_gw;
struct batadv_neigh_node *router;
struct batadv_neigh_ifinfo *router_ifinfo = NULL;
int ret = -1;
router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
if (!router)
goto out;
router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
if (!router_ifinfo)
goto out;
curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
seq_printf(seq, "%s %pM (%9u.%1u) %pM [%10s]: %u.%u/%u.%u MBit\n",
(curr_gw == gw_node ? "=>" : " "),
gw_node->orig_node->orig,
router_ifinfo->bat_v.throughput / 10,
router_ifinfo->bat_v.throughput % 10, router->addr,
router->if_incoming->net_dev->name,
gw_node->bandwidth_down / 10,
gw_node->bandwidth_down % 10,
gw_node->bandwidth_up / 10,
gw_node->bandwidth_up % 10);
ret = seq_has_overflowed(seq) ? -1 : 0;
if (curr_gw)
batadv_gw_node_put(curr_gw);
out:
if (router_ifinfo)
batadv_neigh_ifinfo_put(router_ifinfo);
if (router)
batadv_neigh_node_put(router);
return ret;
}
/**
* batadv_v_gw_print - print the gateway list
* @bat_priv: the bat priv with all the soft interface information
* @seq: gateway table seq_file struct
*/
static void batadv_v_gw_print(struct batadv_priv *bat_priv,
struct seq_file *seq)
{
struct batadv_gw_node *gw_node;
int gw_count = 0;
seq_puts(seq,
" Gateway ( throughput) Nexthop [outgoingIF]: advertised uplink bandwidth\n");
rcu_read_lock();
hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
/* fails if orig_node has no router */
if (batadv_v_gw_write_buffer_text(bat_priv, seq, gw_node) < 0)
continue;
gw_count++;
}
rcu_read_unlock();
if (gw_count == 0)
seq_puts(seq, "No gateways in range ...\n");
}
static struct batadv_algo_ops batadv_batman_v __read_mostly = {
.name = "BATMAN_V",
.iface = {
......@@ -371,6 +580,9 @@ static struct batadv_algo_ops batadv_batman_v __read_mostly = {
.gw = {
.store_sel_class = batadv_v_store_sel_class,
.show_sel_class = batadv_v_show_sel_class,
.get_best_gw_node = batadv_v_gw_get_best_gw_node,
.is_eligible = batadv_v_gw_is_eligible,
.print = batadv_v_gw_print,
},
};
......@@ -397,7 +609,16 @@ void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
*/
int batadv_v_mesh_init(struct batadv_priv *bat_priv)
{
return batadv_v_ogm_init(bat_priv);
int ret = 0;
ret = batadv_v_ogm_init(bat_priv);
if (ret < 0)
return ret;
/* set default throughput difference threshold to 5Mbps */
atomic_set(&bat_priv->gw.sel_class, 50);
return 0;
}
/**
......
......@@ -360,8 +360,7 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
*
* Return: gateway node if found or NULL otherwise.
*/
static struct batadv_gw_node *
batadv_gw_node_get(struct batadv_priv *bat_priv,
struct batadv_gw_node *batadv_gw_node_get(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node)
{
struct batadv_gw_node *gw_node_tmp, *gw_node = NULL;
......
......@@ -47,5 +47,7 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, struct sk_buff *skb);
enum batadv_dhcp_recipient
batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
u8 *chaddr);
struct batadv_gw_node *batadv_gw_node_get(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node);
#endif /* _NET_BATMAN_ADV_GATEWAY_CLIENT_H_ */
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