From: Grant Erickson <gerickson@nuovations.com>
To: connman@lists.linux.dev
Subject: [PATCH] service: Qualify call to '__connman_timeserver_sync' with default check.
Date: Tue, 19 Dec 2023 17:24:37 -0800 [thread overview]
Message-ID: <20231220012437.2259325-1-gerickson@nuovations.com> (raw)
This qualifies the call to '__connman_timeserver_sync' in
'__connman_service_ipconfig_indicate_state' with a check against
'connman_service_is_default'.
In a multi-technology and -service environment, there may be a senior,
default service that is providing the network service for time-of-day
synchronization.
Without the 'connman_service_is_default' qualification, in a
multi-technology and -service environment, as junior services
transitions to the 'ready' state, each of those service usurp the
senior, default service and start trying to provide time-of-day
synchronization which is NOT what is desired.
So, in a configuration with Ethernet, Wi-Fi, and Cellular in which
they are preferred in that order and in which Ethernet is the default
and becomes 'ready' first, Ethernet will provide the network service
for time-of-day synchronization. Then, once Wi-Fi becomes 'ready', it
will usurp time-of-day synchronization from Ethernet. Similarly, when
Cellular becomes 'ready' it will usurp time-of-day synchronization
from Wi-Fi. In all of those cases, time-of-day synchronization should
have remained with Ethernet until such time as it was/is no longer the
senior, default service.
---
src/service.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/src/service.c b/src/service.c
index b8224e8ff0bc..8e057e051d63 100644
--- a/src/service.c
+++ b/src/service.c
@@ -7773,8 +7773,25 @@ int __connman_service_ipconfig_indicate_state(struct connman_service *service,
if (!is_connected(old_state) && is_connected(new_state)) {
nameserver_add_all(service, type);
- __connman_timeserver_sync(service,
- CONNMAN_TIMESERVER_SYNC_REASON_STATE_UPDATE);
+ /*
+ * Care must be taken here in a multi-technology and -service
+ * environment. In such an environment, there may be a senior,
+ * default service that is providing the network service for
+ * time-of-day synchronization.
+ *
+ * Without an appropriate qualifier here, a junior,
+ * non-default service may come in and usurp the senior,
+ * default service and start trying to provide time-of-day
+ * synchronization which is NOT what is desired.
+ *
+ * However, this qualifier should NOT be moved to the next
+ * most outer block. Otherwise, name servers will not be added
+ * to junior, non-default services and they will be unusable
+ * from a DNS perspective.
+ */
+ if (connman_service_is_default(service))
+ __connman_timeserver_sync(service,
+ CONNMAN_TIMESERVER_SYNC_REASON_STATE_UPDATE);
}
return service_indicate_state(service);
--
2.42.0
next reply other threads:[~2023-12-20 1:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-20 1:24 Grant Erickson [this message]
2023-12-23 12:20 ` [PATCH] service: Qualify call to '__connman_timeserver_sync' with default check Marcel Holtmann
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