network: attach device to DHCP clients

The attached sd_device object will be used later.

src/network/networkd-dhcp4.c

@@ -1357,6 +1357,10 @@ static int dhcp4_configure(Link *link) {
         if (r < 0)
                 return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed to attach event to DHCPv4 client: %m");
 
+        r = sd_dhcp_client_attach_device(link->dhcp_client, link->dev);
+        if (r < 0)
+                return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed to attach device: %m");
+
         r = sd_dhcp_client_set_mac(link->dhcp_client,
                                    link->hw_addr.bytes,
                                    link->bcast_addr.length > 0 ? link->bcast_addr.bytes : NULL,

src/network/networkd-dhcp6.c

@@ -594,6 +594,10 @@ static int dhcp6_configure(Link *link) {
         if (r < 0)
                 return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to attach event: %m");
 
+        r = sd_dhcp6_client_attach_device(client, link->dev);
+        if (r < 0)
+                return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to attach device: %m");
+
         r = dhcp6_set_identifier(link, client);
         if (r < 0)
                 return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to set identifier: %m");

src/network/networkd-link.c

@@ -1410,6 +1410,18 @@ static int link_initialized(Link *link, sd_device *device) {
          * or sysattrs) may be outdated. */
         device_unref_and_replace(link->dev, device);
 
+        if (link->dhcp_client) {
+                r = sd_dhcp_client_attach_device(link->dhcp_client, link->dev);
+                if (r < 0)
+                        log_link_warning_errno(link, r, "Failed to attach device to DHCPv4 client, ignoring: %m");
+        }
+
+        if (link->dhcp6_client) {
+                r = sd_dhcp6_client_attach_device(link->dhcp6_client, link->dev);
+                if (r < 0)
+                        log_link_warning_errno(link, r, "Failed to attach device to DHCPv6 client, ignoring: %m");
+        }
+
         r = link_set_sr_iov_ifindices(link);
         if (r < 0)
                 log_link_warning_errno(link, r, "Failed to manage SR-IOV PF and VF ports, ignoring: %m");