From 34714ff8fff2a4618ce725a3e0c22b0abac00faa Mon Sep 17 00:00:00 2001 From: Beniamino Galvani Date: Wed, 24 Aug 2022 16:52:52 +0200 Subject: [PATCH] device: restart DHCP when the MAC changes If the MAC changes there is the possibility that the DHCP client will not be able to renew the address because it uses the old MAC as CHADDR. Depending on the implementation, the DHCP server might use CHADDR (so, the old address) as the destination MAC for DHCP replies, and those packets will be lost. To avoid this problem, restart the DHCP client when the MAC changes. https://bugzilla.redhat.com/show_bug.cgi?id=2110000 --- src/core/devices/nm-device.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/core/devices/nm-device.c b/src/core/devices/nm-device.c index 96b4a1d26b..16a8e9028a 100644 --- a/src/core/devices/nm-device.c +++ b/src/core/devices/nm-device.c @@ -6637,6 +6637,7 @@ device_link_changed(gpointer user_data) NMDeviceClass *klass = NM_DEVICE_GET_CLASS(self); NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE(self); gboolean ip_ifname_changed = FALSE; + gboolean hw_addr_changed = FALSE; nm_auto_nmpobj const NMPObject *pllink_keep_alive = NULL; const NMPlatformLink *pllink; const char *str; @@ -6684,7 +6685,7 @@ device_link_changed(gpointer user_data) _stats_update_counters_from_pllink(self, pllink); had_hw_addr = (priv->hw_addr != NULL); - nm_device_update_hw_address(self); + hw_addr_changed = nm_device_update_hw_address(self); got_hw_addr = (!had_hw_addr && priv->hw_addr); nm_device_update_permanent_hw_address(self, FALSE); @@ -6736,6 +6737,8 @@ device_link_changed(gpointer user_data) /* Update DHCP, etc, if needed */ if (ip_ifname_changed) nm_device_update_dynamic_ip_setup(self, "IP interface changed"); + else if (hw_addr_changed) + nm_device_update_dynamic_ip_setup(self, "hw-address changed"); was_up = priv->up; priv->up = NM_FLAGS_HAS(pllink->n_ifi_flags, IFF_UP);