From 438a0a9ad5287a82b1872c9783cc8fa4b548d49e Mon Sep 17 00:00:00 2001 From: Beniamino Galvani Date: Thu, 12 Sep 2019 17:33:49 +0200 Subject: [PATCH] macsec: update MTU according to parent's one A MACsec connection doesn't have an ordering dependency with its parent connection and so it's possible that the parent gets activated later and sets a greater MTU than the original one. It is reasonable and useful to keep the MACsec MTU configured by default as the maximum allowed by the parent interface, that is the parent MTU minus the encapsulation overhead (32). The user can of course override this by setting an explicit value in the connection. We already do something similar for VLANs. https://bugzilla.redhat.com/show_bug.cgi?id=1723690 --- src/devices/nm-device-macsec.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/src/devices/nm-device-macsec.c b/src/devices/nm-device-macsec.c index 17ee53c56..c9592a497 100644 --- a/src/devices/nm-device-macsec.c +++ b/src/devices/nm-device-macsec.c @@ -52,6 +52,7 @@ NM_GOBJECT_PROPERTIES_DEFINE (NMDeviceMacsec, typedef struct { NMPlatformLnkMacsec props; gulong parent_state_id; + gulong parent_mtu_id; Supplicant supplicant; guint supplicant_timeout_id; NMActRequestGetSecretsCallId *macsec_secrets_id; @@ -99,6 +100,17 @@ parent_state_changed (NMDevice *parent, nm_device_set_unmanaged_by_flags (NM_DEVICE (self), NM_UNMANAGED_PARENT, !nm_device_get_managed (parent, FALSE), reason); } +static void +parent_mtu_maybe_changed (NMDevice *parent, + GParamSpec *pspec, + gpointer user_data) +{ + /* the MTU of a MACsec device is limited by the parent's MTU. + * + * When the parent's MTU changes, try to re-set the MTU. */ + nm_device_commit_mtu (user_data); +} + static void parent_changed_notify (NMDevice *device, int old_ifindex, @@ -119,12 +131,16 @@ parent_changed_notify (NMDevice *device, * because NMDevice's dispose() will unset the parent, which in turn calls * parent_changed_notify(). */ nm_clear_g_signal_handler (old_parent, &priv->parent_state_id); + nm_clear_g_signal_handler (old_parent, &priv->parent_mtu_id); if (new_parent) { priv->parent_state_id = g_signal_connect (new_parent, NM_DEVICE_STATE_CHANGED, G_CALLBACK (parent_state_changed), device); + priv->parent_mtu_id = g_signal_connect (new_parent, "notify::" NM_DEVICE_MTU, + G_CALLBACK (parent_mtu_maybe_changed), device); + /* Set parent-dependent unmanaged flag */ nm_device_set_unmanaged_by_flags (device, @@ -779,11 +795,15 @@ static void dispose (GObject *object) { NMDeviceMacsec *self = NM_DEVICE_MACSEC (object); + NMDeviceMacsecPrivate *priv = NM_DEVICE_MACSEC_GET_PRIVATE (self); macsec_secrets_cancel (self); supplicant_interface_release (self); G_OBJECT_CLASS (nm_device_macsec_parent_class)->dispose (object); + + nm_assert (priv->parent_state_id == 0); + nm_assert (priv->parent_mtu_id == 0); } static const NMDBusInterfaceInfoExtended interface_info_device_macsec = { @@ -826,6 +846,7 @@ nm_device_macsec_class_init (NMDeviceMacsecClass *klass) device_class->connection_type_supported = NM_SETTING_MACSEC_SETTING_NAME; device_class->connection_type_check_compatible = NM_SETTING_MACSEC_SETTING_NAME; device_class->link_types = NM_DEVICE_DEFINE_LINK_TYPES (NM_LINK_TYPE_MACSEC); + device_class->mtu_parent_delta = 32; device_class->act_stage2_config = act_stage2_config; device_class->create_and_realize = create_and_realize; @@ -835,7 +856,7 @@ nm_device_macsec_class_init (NMDeviceMacsecClass *klass) device_class->is_available = is_available; device_class->parent_changed_notify = parent_changed_notify; device_class->state_changed = device_state_changed; - device_class->get_configured_mtu = nm_device_get_configured_mtu_for_wired; + device_class->get_configured_mtu = nm_device_get_configured_mtu_wired_parent; obj_properties[PROP_SCI] = g_param_spec_uint64 (NM_DEVICE_MACSEC_SCI, "", "",