A DHCP session holds a persistent reference to a network device

diff --git a/src/include/gpxe/dhcp.h b/src/include/gpxe/dhcp.h
index 9ce8113decc9f6aeefa91d88e3fb7b666db933e5..60991e7e8d5fcd934c65b26890651f83755521f2 100644 (file)
--- a/src/include/gpxe/dhcp.h
+++ b/src/include/gpxe/dhcp.h
@@ -13,6 +13,7 @@
 #include <gpxe/udp.h>
 #include <gpxe/async.h>
 #include <gpxe/retry.h>
+#include <gpxe/hotplug.h>
 
 /** BOOTP/DHCP server port */
 #define BOOTPS_PORT 67
@@ -452,6 +453,8 @@ struct dhcp_session {
 
        /** Network device being configured */
        struct net_device *netdev;
+       /** Persistent reference to network device */
+       struct reference netdev_ref;
 
        /** Options obtained from server */
        struct dhcp_option_block *options;

diff --git a/src/net/udp/dhcp.c b/src/net/udp/dhcp.c
index f810777701f6d44f2ba3bfe8238045b7372a44c1..59dc8071414a0fe4941fd386efe078277d6abc94 100644 (file)
--- a/src/net/udp/dhcp.c
+++ b/src/net/udp/dhcp.c
@@ -498,6 +498,7 @@ udp_to_dhcp ( struct udp_connection *conn ) {
  * @v rc               Return status code
  */
 static void dhcp_done ( struct dhcp_session *dhcp, int rc ) {
+
        /* Free up options if we failed */
        if ( rc != 0 ) {
                if ( dhcp->options ) {
@@ -506,9 +507,15 @@ static void dhcp_done ( struct dhcp_session *dhcp, int rc ) {
                }
        }
 
+       /* Stop retry timer */
+       stop_timer ( &dhcp->timer );
+
        /* Close UDP connection */
        udp_close ( &dhcp->udp );
 
+       /* Release reference on net device */
+       ref_del ( &dhcp->netdev_ref );
+
        /* Mark async operation as complete */
        async_done ( &dhcp->aop, rc );
 }
@@ -689,6 +696,19 @@ static struct udp_operations dhcp_udp_operations = {
        .newdata        = dhcp_newdata,
 };
 
+/**
+ * Forget reference to net_device
+ *
+ * @v ref              Persistent reference
+ */
+static void dhcp_forget_netdev ( struct reference *ref ) {
+       struct dhcp_session *dhcp
+               = container_of ( ref, struct dhcp_session, netdev_ref );
+
+       /* Kill DHCP session immediately */
+       dhcp_done ( dhcp, -ENETUNREACH );
+}
+
 /**
  * Initiate DHCP on a network interface
  *
@@ -714,6 +734,10 @@ struct async_operation * start_dhcp ( struct dhcp_session *dhcp ) {
                goto out;
        }
 
+       /* Add persistent reference to net device */
+       dhcp->netdev_ref.forget = dhcp_forget_netdev;
+       ref_add ( &dhcp->netdev_ref, &dhcp->netdev->references );
+
        /* Proof of concept: just send a single DHCPDISCOVER */
        dhcp_send_request ( dhcp );