[B.A.T.M.A.N.] [PATCHv2 1/2] batman-adv: deselect current GW on client mode switch off

[B.A.T.M.A.N.] [PATCHv2 1/2] batman-adv: deselect current GW on client mode switch off

[Antonio Quartulli]

From: Antonio Quartulli <antonio@open-mesh.com>

When switching from gw_mode client to either off or server
the current selected gateway has to be deselected.
In this way when client mode is enabled again a gateway
re-election is forced and a GW_ADD event is consequently
sent.

The current behaviour instead is to keep the current gateway
leading to no GW_ADD event when gw_mode client is selected
for a second time

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
---

Changes from v1:
* Introduce patch 2 to rename batadv_gw_deselect()
* add big fat comment in 1/2 that explain why invoking batadv_gw_deselect() is
  not enough to really deselect the current GW

Cheers,


 gateway_client.c | 4 ++++
 sysfs.c          | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/gateway_client.c b/gateway_client.c
index 2449afa..2903bdb 100644
--- a/gateway_client.c
+++ b/gateway_client.c
@@ -207,6 +207,10 @@ void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
 	if (!curr_gw)
 		return;
 
+	/* deselect the current gateway so that next time that client mode is
+	 * enabled a proper GW_ADD event can be sent */
+	batadv_gw_select(bat_priv, NULL);
+
 	/* if batman-adv is switching the gw client mode off and a gateway was
 	 * already selected, send a DEL uevent
 	 */
diff --git a/sysfs.c b/sysfs.c
index 6335433..d1765fd 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -408,6 +408,15 @@ static ssize_t batadv_store_gw_mode(struct kobject *kobj,
 	batadv_info(net_dev, "Changing gw mode from: %s to: %s\n",
 		    curr_gw_mode_str, buff);
 
+	/* invoking batadv_gw_deselect() is not enough to really de-select the
+	 * current GW. It will only instruct the gateway code to perform a
+	 * re-election the next time that this is needed.
+	 *
+	 * When gw client mode is being switched off the current GW must be
+	 * de-selected explicitly otherwise no GW_ADD uevent is thrown on
+	 * client mode reactivation. This is operation is performed in
+	 * batadv_gw_check_client_stop().
+	 */
 	batadv_gw_deselect(bat_priv);
 	/* always call batadv_gw_check_client_stop() before changing the gateway
 	 * state
-- 
1.8.4

[B.A.T.M.A.N.] [PATCHv2 2/2] batman-adv: rename gw_deselect() to gw_reselect()

[Antonio Quartulli]

From: Antonio Quartulli <antonio@open-mesh.com>

The function batadv_gw_deselect() is actually not deselecting
anything. It is just informing the GW code to perform a
re-election procedure when possible.
The current gateway is not being touched at all and therefore
the name of this function is rather misleading.

Rename it to batadv_gw_reselect() to batadv_gw_reselect()
to make its behaviour easier to grasp.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
---
 gateway_client.c | 35 +++++++++++++++++++++++------------
 gateway_common.c |  2 +-
 sysfs.c          | 10 +++++-----
 3 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/gateway_client.c b/gateway_client.c
index 2903bdb..fcaebec 100644
--- a/gateway_client.c
+++ b/gateway_client.c
@@ -105,7 +105,18 @@ static void batadv_gw_select(struct batadv_priv *bat_priv,
 	spin_unlock_bh(&bat_priv->gw.list_lock);
 }
 
-void batadv_gw_deselect(struct batadv_priv *bat_priv)
+/**
+ * batadv_gw_reselect - force a gateway reselection
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Set a flag to remind the GW component to perform a new gateway reselection.
+ * However this function does not ensure that the current gateway is going to be
+ * deselected. The reselection mechanism may elect the same gateway once again.
+ *
+ * This means that invoking batadv_gw_reselect() does not guarantee a gateway
+ * change and therefore a uevent is not necessarily expected.
+ */
+void batadv_gw_reselect(struct batadv_priv *bat_priv)
 {
 	atomic_set(&bat_priv->gw.reselect, 1);
 }
@@ -243,7 +254,7 @@ void batadv_gw_election(struct batadv_priv *bat_priv)
 
 		router = batadv_orig_node_get_router(next_gw->orig_node);
 		if (!router) {
-			batadv_gw_deselect(bat_priv);
+			batadv_gw_reselect(bat_priv);
 			goto out;
 		}
 	}
@@ -295,11 +306,11 @@ void batadv_gw_check_election(struct batadv_priv *bat_priv,
 
 	curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
 	if (!curr_gw_orig)
-		goto deselect;
+		goto reselect;
 
 	router_gw = batadv_orig_node_get_router(curr_gw_orig);
 	if (!router_gw)
-		goto deselect;
+		goto reselect;
 
 	/* this node already is the gateway */
 	if (curr_gw_orig == orig_node)
@@ -327,8 +338,8 @@ void batadv_gw_check_election(struct batadv_priv *bat_priv,
 		   "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
 		   gw_tq_avg, orig_tq_avg);
 
-deselect:
-	batadv_gw_deselect(bat_priv);
+reselect:
+	batadv_gw_reselect(bat_priv);
 out:
 	if (curr_gw_orig)
 		batadv_orig_node_free_ref(curr_gw_orig);
@@ -458,7 +469,7 @@ void batadv_gw_node_update(struct batadv_priv *bat_priv,
 		 */
 		curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 		if (gw_node == curr_gw)
-			batadv_gw_deselect(bat_priv);
+			batadv_gw_reselect(bat_priv);
 	}
 
 out:
@@ -484,7 +495,7 @@ void batadv_gw_node_purge(struct batadv_priv *bat_priv)
 	struct batadv_gw_node *gw_node, *curr_gw;
 	struct hlist_node *node_tmp;
 	unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
-	int do_deselect = 0;
+	int do_reselect = 0;
 
 	curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
 
@@ -498,7 +509,7 @@ void batadv_gw_node_purge(struct batadv_priv *bat_priv)
 			continue;
 
 		if (curr_gw == gw_node)
-			do_deselect = 1;
+			do_reselect = 1;
 
 		hlist_del_rcu(&gw_node->list);
 		batadv_gw_node_free_ref(gw_node);
@@ -506,9 +517,9 @@ void batadv_gw_node_purge(struct batadv_priv *bat_priv)
 
 	spin_unlock_bh(&bat_priv->gw.list_lock);
 
-	/* gw_deselect() needs to acquire the gw_list_lock */
-	if (do_deselect)
-		batadv_gw_deselect(bat_priv);
+	/* gw_reselect() needs to acquire the gw_list_lock */
+	if (do_reselect)
+		batadv_gw_reselect(bat_priv);
 
 	if (curr_gw)
 		batadv_gw_node_free_ref(curr_gw);
diff --git a/gateway_common.c b/gateway_common.c
index b211b0f..5795d9a 100644
--- a/gateway_common.c
+++ b/gateway_common.c
@@ -164,7 +164,7 @@ ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 	if ((down_curr == down_new) && (up_curr == up_new))
 		return count;
 
-	batadv_gw_deselect(bat_priv);
+	batadv_gw_reselect(bat_priv);
 	batadv_info(net_dev,
 		    "Changing gateway bandwidth from: '%u.%u/%u.%u MBit' to: '%u.%u/%u.%u MBit'\n",
 		    down_curr / 10, down_curr % 10, up_curr / 10, up_curr % 10,
diff --git a/sysfs.c b/sysfs.c
index d1765fd..c686313 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -329,10 +329,10 @@ static ssize_t batadv_show_bat_algo(struct kobject *kobj,
 	return sprintf(buff, "%s\n", bat_priv->bat_algo_ops->name);
 }
 
-static void batadv_post_gw_deselect(struct net_device *net_dev)
+static void batadv_post_gw_reselect(struct net_device *net_dev)
 {
 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
-	batadv_gw_deselect(bat_priv);
+	batadv_gw_reselect(bat_priv);
 }
 
 static ssize_t batadv_show_gw_mode(struct kobject *kobj, struct attribute *attr,
@@ -408,7 +408,7 @@ static ssize_t batadv_store_gw_mode(struct kobject *kobj,
 	batadv_info(net_dev, "Changing gw mode from: %s to: %s\n",
 		    curr_gw_mode_str, buff);
 
-	/* invoking batadv_gw_deselect() is not enough to really de-select the
+	/* invoking batadv_gw_reselect() is not enough to really de-select the
 	 * current GW. It will only instruct the gateway code to perform a
 	 * re-election the next time that this is needed.
 	 *
@@ -417,7 +417,7 @@ static ssize_t batadv_store_gw_mode(struct kobject *kobj,
 	 * client mode reactivation. This is operation is performed in
 	 * batadv_gw_check_client_stop().
 	 */
-	batadv_gw_deselect(bat_priv);
+	batadv_gw_reselect(bat_priv);
 	/* always call batadv_gw_check_client_stop() before changing the gateway
 	 * state
 	 */
@@ -470,7 +470,7 @@ BATADV_ATTR_SIF_UINT(orig_interval, S_IRUGO | S_IWUSR, 2 * BATADV_JITTER,
 BATADV_ATTR_SIF_UINT(hop_penalty, S_IRUGO | S_IWUSR, 0, BATADV_TQ_MAX_VALUE,
 		     NULL);
 BATADV_ATTR_SIF_UINT(gw_sel_class, S_IRUGO | S_IWUSR, 1, BATADV_TQ_MAX_VALUE,
-		     batadv_post_gw_deselect);
+		     batadv_post_gw_reselect);
 static BATADV_ATTR(gw_bandwidth, S_IRUGO | S_IWUSR, batadv_show_gw_bwidth,
 		   batadv_store_gw_bwidth);
 #ifdef CONFIG_BATMAN_ADV_DEBUG
-- 
1.8.4

Re: [B.A.T.M.A.N.] [PATCHv2 2/2] batman-adv: rename gw_deselect() to gw_reselect()

[Antonio Quartulli]

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On Sun, Oct 27, 2013 at 01:02:59PM +0100, Antonio Quartulli wrote:
> From: Antonio Quartulli <antonio@open-mesh.com>
> 
> The function batadv_gw_deselect() is actually not deselecting
> anything. It is just informing the GW code to perform a
> re-election procedure when possible.
> The current gateway is not being touched at all and therefore
> the name of this function is rather misleading.
> 
> Rename it to batadv_gw_reselect() to batadv_gw_reselect()
> to make its behaviour easier to grasp.
> 
> Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
> ---
>  gateway_client.c | 35 +++++++++++++++++++++++------------
>  gateway_common.c |  2 +-
>  sysfs.c          | 10 +++++-----

The declaration of this function is in gw_client.h but I forgot to change it.

v2 will follow.


Cheers,


-- 
Antonio Quartulli

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[B.A.T.M.A.N.] [PATCHv2 1/2] batman-adv: deselect current GW on client mode switch off

[Antonio Quartulli]

From: Antonio Quartulli <antonio@open-mesh.com>

When switching from gw_mode client to either off or server
the current selected gateway has to be deselected.
In this way when client mode is enabled again a gateway
re-election is forced and a GW_ADD event is consequently
sent.

The current behaviour instead is to keep the current gateway
leading to no GW_ADD event when gw_mode client is selected
for a second time

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
---

Patch 2/2:
- rename gw_deselect to gw_reselect in gw_client.h

Cheers,


 gateway_client.c | 4 ++++
 sysfs.c          | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/gateway_client.c b/gateway_client.c
index 2449afa..2903bdb 100644
--- a/gateway_client.c
+++ b/gateway_client.c
@@ -207,6 +207,10 @@ void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
 	if (!curr_gw)
 		return;
 
+	/* deselect the current gateway so that next time that client mode is
+	 * enabled a proper GW_ADD event can be sent */
+	batadv_gw_select(bat_priv, NULL);
+
 	/* if batman-adv is switching the gw client mode off and a gateway was
 	 * already selected, send a DEL uevent
 	 */
diff --git a/sysfs.c b/sysfs.c
index 6335433..d1765fd 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -408,6 +408,15 @@ static ssize_t batadv_store_gw_mode(struct kobject *kobj,
 	batadv_info(net_dev, "Changing gw mode from: %s to: %s\n",
 		    curr_gw_mode_str, buff);
 
+	/* invoking batadv_gw_deselect() is not enough to really de-select the
+	 * current GW. It will only instruct the gateway code to perform a
+	 * re-election the next time that this is needed.
+	 *
+	 * When gw client mode is being switched off the current GW must be
+	 * de-selected explicitly otherwise no GW_ADD uevent is thrown on
+	 * client mode reactivation. This is operation is performed in
+	 * batadv_gw_check_client_stop().
+	 */
 	batadv_gw_deselect(bat_priv);
 	/* always call batadv_gw_check_client_stop() before changing the gateway
 	 * state
-- 
1.8.4.2

Re: [B.A.T.M.A.N.] [PATCHv2 1/2] batman-adv: deselect current GW on client mode switch off

[Marek Lindner]

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On Monday 04 November 2013 20:59:40 Antonio Quartulli wrote:
> From: Antonio Quartulli <antonio@open-mesh.com>
> 
> When switching from gw_mode client to either off or server
> the current selected gateway has to be deselected.
> In this way when client mode is enabled again a gateway
> re-election is forced and a GW_ADD event is consequently
> sent.
> 
> The current behaviour instead is to keep the current gateway
> leading to no GW_ADD event when gw_mode client is selected
> for a second time
> 
> Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
> ---
> 
> Patch 2/2:
> - rename gw_deselect to gw_reselect in gw_client.h
> 
> Cheers,
> 
> 
>  gateway_client.c | 4 ++++
>  sysfs.c          | 9 +++++++++
>  2 files changed, 13 insertions(+)

Applied in revision 99a6eb5.

Thanks,
Marek

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