Re: Getting NM to re-try DHCP

[Jirka Klimes <jklimes redhat com>]

On Saturday 09 of April 2011 02:01:09 Mikhail Efremov wrote:
> On Wed, 06 Apr 2011 17:24:44 -0500 Dan Williams wrote:
> > On Tue, 2011-04-05 at 11:37 -0400, Derek Atkins wrote:
> > > Hey all,
> > > 
> > > I have a strange issue.  I lost power last night and one of my
> > > systems came up before my DHCP server did (which is surprising,
> > > because my DHCP server usually comes up pretty quick!)  This
> > > "client" system was supposed to get itself on the network (it has
> > > an auto-logon system). However, NM didn't succeed because my DHCP
> > > server wasn't responding, yet.
> > > 
> > > This is a hard-wired system (not wireless).  Is there any way to
> > > get NM to periodically retry DHCP if at first it does not succeed?
> > > 
> > > I realize that DHCP has its own retry mechanism, but if the whole
> > > process times out, can I set NM to retry every, say, 5 minutes?
> > 
> > We'd need some code changes in NM; basically for wired connections if
> > the activation attempt fails a certain number of times (currently 3)
> > then the connection is marked "invalid".  What probably should happen
> > is that internally, in nm-policy.c, a timeout handler should be
> > scheduled for the connection (using g_timeout_add_seconds()) that
> > triggers after 5 minutes or so and if the connection isn't currently
> > active (ie check the NMManager's active connection list) then the
> > invalid flag is cleared from the connection, which will let it be
> > automatically retried.
> 
> Not on this issue exactly, but this is reminded me about my old patch
> which was written long time ago (it was just forgotten to submit, sorry).
> If cable was unplugged, then when it is replugged this may be another
> network, so NM should try to reconnect even if the connection was
> early marked as "invalid".
> This patch for the NM_0_8 branch, for master it should be remaked, but
> I have no time to do this right now, sorry. And there may be no
> necessary for a separate function to clear the tag.

Looks good. However, we may want to remove the 'invalid' flag for all 
connections compatible with the device.

Patches both for NM_0_8 and master attached.

Jirka

From fd1fcb95bcd2edc565ff75d21ca7f36f6139018b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ji=C5=99=C3=AD=20Klime=C5=A1?= <jklimes redhat com>
Date: Mon, 23 May 2011 12:23:28 +0200
Subject: [PATCH] core: clear 'invalid' tag when cable is replugged
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When re-plugging we may be in a different network. So remove invalid tag from
compatible connection so that they can be tried again.

Based on a patch from Mikhail Efremov.

Signed-off-by: Jiří Klimeš <jklimes redhat com>
---
 src/nm-policy.c |   33 ++++++++++++++++++++++++++++++++-
 1 files changed, 32 insertions(+), 1 deletions(-)

diff --git a/src/nm-policy.c b/src/nm-policy.c
index da6ce94..78efef0 100644
--- a/src/nm-policy.c
+++ b/src/nm-policy.c
@@ -848,6 +848,32 @@ get_device_connection (NMDevice *device)
 }
 
 static void
+clear_invalid_tag (NMManager *manager, NMDevice *device)
+{
+	GSList *connections, *iter;
+	NMDeviceInterface *dev_iface;
+	GError *error = NULL;
+
+	g_return_if_fail (NM_IS_MANAGER (manager));
+	g_return_if_fail (NM_IS_DEVICE (device));
+
+	dev_iface = NM_DEVICE_INTERFACE (device);
+
+	/* System connections first, then user connections */
+	connections = nm_manager_get_connections (manager, NM_CONNECTION_SCOPE_SYSTEM);
+	connections = g_slist_concat (connections, nm_manager_get_connections (manager, NM_CONNECTION_SCOPE_USER));
+
+	/* Clear INVALID_TAG for all connections compatible with the device */
+	for (iter = connections; iter; iter = g_slist_next (iter)) {
+		if (nm_device_interface_check_connection_compatible (dev_iface, iter->data, &error))
+			g_object_set_data (G_OBJECT (iter->data), INVALID_TAG, NULL);
+		g_object_unref (G_OBJECT (iter->data));
+		g_clear_error (&error);
+	}
+	g_slist_free (connections);
+}
+
+static void
 device_state_changed (NMDevice *device,
                       NMDeviceState new_state,
                       NMDeviceState old_state,
@@ -882,9 +908,14 @@ device_state_changed (NMDevice *device,
 
 		update_routing_and_dns (policy, FALSE);
 		break;
+	case NM_DEVICE_STATE_DISCONNECTED:
+		/* Clear INVALID_TAG when carrier on. If cable was unplugged
+		 * and plugged again, we should try to reconnect */
+		if (reason == NM_DEVICE_STATE_REASON_CARRIER && old_state == NM_DEVICE_STATE_UNAVAILABLE)
+			clear_invalid_tag (policy->manager, device);
+		/* fall through */
 	case NM_DEVICE_STATE_UNMANAGED:
 	case NM_DEVICE_STATE_UNAVAILABLE:
-	case NM_DEVICE_STATE_DISCONNECTED:
 		update_routing_and_dns (policy, FALSE);
 		schedule_activate_check (policy, device, 0);
 		break;
-- 
1.7.4.4

From 15825c119e33b15f5782b6c47c6fff452db9d5a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ji=C5=99=C3=AD=20Klime=C5=A1?= <jklimes redhat com>
Date: Mon, 23 May 2011 12:50:25 +0200
Subject: [PATCH] core: reset auto retries counter when cable is replugged
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When re-plugging we may be in a different network. So we should try the
compatible connections again.

Based on a patch from Mikhail Efremov.

Signed-off-by: Jiří Klimeš <jklimes redhat com>
---
 src/nm-policy.c |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/nm-policy.c b/src/nm-policy.c
index 194d111..b98fe32 100644
--- a/src/nm-policy.c
+++ b/src/nm-policy.c
@@ -817,13 +817,17 @@ hostname_changed (NMManager *manager, GParamSpec *pspec, gpointer user_data)
 }
 
 static void
-reset_retries_all (NMSettings *settings)
+reset_retries_all (NMSettings *settings, NMDevice *device)
 {
 	GSList *connections, *iter;
+	GError *error = NULL;
 
 	connections = nm_settings_get_connections (settings);
-	for (iter = connections; iter; iter = g_slist_next (iter))
-		set_connection_auto_retries (NM_CONNECTION (iter->data), RETRIES_DEFAULT);
+	for (iter = connections; iter; iter = g_slist_next (iter)) {
+		if (!device || nm_device_interface_check_connection_compatible (NM_DEVICE_INTERFACE (device), iter->data, &error))
+			set_connection_auto_retries (NM_CONNECTION (iter->data), RETRIES_DEFAULT);
+		g_clear_error (&error);
+	}
 	g_slist_free (connections);
 }
 
@@ -838,7 +842,7 @@ sleeping_changed (NMManager *manager, GParamSpec *pspec, gpointer user_data)
 
 	/* Reset retries on all connections so they'll checked on wakeup */
 	if (sleeping || !enabled)
-		reset_retries_all (policy->settings);
+		reset_retries_all (policy->settings, NULL);
 }
 
 static void
@@ -932,6 +936,11 @@ device_state_changed (NMDevice *device,
 		update_routing_and_dns (policy, FALSE);
 		break;
 	case NM_DEVICE_STATE_DISCONNECTED:
+		/* Clear INVALID_TAG when carrier on. If cable was unplugged
+		 * and plugged again, we should try to reconnect */
+		if (reason == NM_DEVICE_STATE_REASON_CARRIER && old_state == NM_DEVICE_STATE_UNAVAILABLE)
+			reset_retries_all (policy->settings, device);
+
 		/* Device is now available for auto-activation */
 		update_routing_and_dns (policy, FALSE);
 		schedule_activate_check (policy, device, 0);
@@ -1058,7 +1067,7 @@ connections_loaded (NMSettings *settings, gpointer user_data)
 	// that by calling reset_retries_all() in nm_policy_new()
 	
 	/* Initialize connections' auto-retries */
-	reset_retries_all (settings);
+	reset_retries_all (settings, NULL);
 
 	schedule_activate_all ((NMPolicy *) user_data);
 }
@@ -1188,7 +1197,7 @@ nm_policy_new (NMManager *manager,
 	                          connection_visibility_changed);
 
 	/* Initialize connections' auto-retries */
-	reset_retries_all (policy->settings);
+	reset_retries_all (policy->settings, NULL);
 
 	initialized = TRUE;
 	return policy;
-- 
1.7.4.4