[interface] Fix debug message values for temporary interfaces

The interface debug message values constructed by INTF_DBG() et al
rely on the interface being embedded within a containing object.  This
assumption is not valid for the temporary outbound-only interfaces
constructed on the stack by intf_shutdown() and xfer_vredirect().

Formalise the notion of a temporary outbound-only interface as having
a NULL interface descriptor, and overload the "original interface
descriptor" field to contain a pointer to the original interface that
the temporary interface is shadowing.

Originally-fixed-by: Vincent Fazio <vfazio@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/core/interface.c b/src/core/interface.c
index 34a4180a57cf10f823648c4d69c15545d6bcf1fe..ea060689393f9f049de70b3ebb2d18f3de4bdf4e 100644 (file)
--- a/src/core/interface.c
+++ b/src/core/interface.c
@@ -285,6 +285,7 @@ void intf_shutdown ( struct interface *intf, int rc ) {
        intf_nullify ( intf );
 
        /* Transfer destination to temporary interface */
+       intf_temp_init ( &tmp, intf );
        tmp.dest = intf->dest;
        intf->dest = &null_intf;
 

diff --git a/src/core/xfer.c b/src/core/xfer.c
index 0faf3292aa63ae88d0ae908efde28bae1ef68a5f..269359e1538f1086a35103aa729e764ca815304e 100644 (file)
--- a/src/core/xfer.c
+++ b/src/core/xfer.c
@@ -60,7 +60,7 @@ static struct xfer_metadata dummy_metadata;
  * @ret rc             Return status code
  */
 int xfer_vredirect ( struct interface *intf, int type, va_list args ) {
-       struct interface tmp = INTF_INIT ( null_intf_desc );
+       struct interface tmp;
        struct interface *dest;
        xfer_vredirect_TYPE ( void * ) *op =
                intf_get_dest_op_no_passthru ( intf, xfer_vredirect, &dest );
@@ -85,6 +85,7 @@ int xfer_vredirect ( struct interface *intf, int type, va_list args ) {
                 * If redirection fails, then send intf_close() to the
                 * parent interface.
                 */
+               intf_temp_init ( &tmp, intf );
                intf_plug ( &tmp, dest );
                rc = xfer_vreopen ( dest, type, args );
                if ( rc == 0 ) {

diff --git a/src/include/ipxe/interface.h b/src/include/ipxe/interface.h
index 19f58a4b4e961d69549d77ad6fe3164dee7536e8..d2fa8190ca7eedb4a8180c75721392ea142b0701 100644 (file)
--- a/src/include/ipxe/interface.h
+++ b/src/include/ipxe/interface.h
@@ -133,17 +133,30 @@ struct interface {
        struct interface *dest;
        /** Reference counter
         *
-        * If this interface is not part of a reference-counted
-        * object, this field may be NULL.
+        * If this interface is not part of a reference-counted object
+        * then this field is NULL.
         */
        struct refcnt *refcnt;
-       /** Interface descriptor */
-       struct interface_descriptor *desc;
-       /** Original interface descriptor
+       /** Interface descriptor
         *
-        * Used by intf_reinit().
+        * If this is a temporary outbound-only interface created by
+        * intf_temp_init() then this field is NULL.
         */
-       struct interface_descriptor *original;
+       struct interface_descriptor *desc;
+       /** Original interface properties */
+       union {
+               /** Original interface descriptor
+                *
+                * Used by intf_reinit().
+                */
+               struct interface_descriptor *desc;
+               /** Original interface
+                *
+                * Used for temporary outbound-only interfaces created
+                * by intf_temp_init().
+                */
+               struct interface *intf;
+       } original;
 };
 
 extern void intf_plug ( struct interface *intf, struct interface *dest );
@@ -193,7 +206,7 @@ static inline void intf_init ( struct interface *intf,
        intf->dest = &null_intf;
        intf->refcnt = refcnt;
        intf->desc = desc;
-       intf->original = desc;
+       intf->original.desc = desc;
 }
 
 /**
@@ -201,13 +214,38 @@ static inline void intf_init ( struct interface *intf,
  *
  * @v descriptor       Object interface descriptor
  */
-#define INTF_INIT( descriptor ) {              \
-               .dest = &null_intf,             \
-               .refcnt = NULL,                 \
-               .desc = &(descriptor),          \
-               .original = &(descriptor),      \
+#define INTF_INIT( descriptor ) {                                      \
+               .dest = &null_intf,                                     \
+               .refcnt = NULL,                                         \
+               .desc = &(descriptor),                                  \
+               .original = {                                           \
+                       .desc = &(descriptor),                          \
+               },                                                      \
        }
 
+/**
+ * Initialise a temporary outbound-only object interface
+ *
+ * @v intf             Temporary outbound-only object interface
+ * @v original         Original object interface
+ */
+static inline void intf_temp_init ( struct interface *intf,
+                                   struct interface *original ) {
+       intf->dest = &null_intf;
+       intf->desc = NULL;
+       intf->original.intf = original;
+}
+
+/**
+ * Get original interface
+ *
+ * @v intf             Object interface (possibly a temporary interface)
+ * @ret intf           Original object interface
+ */
+static inline struct interface * intf_origin ( struct interface *intf ) {
+       return ( intf->desc ? intf : intf->original.intf );
+}
+
 /**
  * Get object interface destination and operation method (without pass-through)
  *
@@ -240,7 +278,7 @@ static inline void intf_init ( struct interface *intf,
  *
  * Use as the first argument to DBGC() or equivalent macro.
  */
-#define INTF_COL( intf ) intf_object ( intf )
+#define INTF_COL( intf ) intf_object ( intf_origin ( intf ) )
 
 /** printf() format string for INTF_DBG() */
 #define INTF_FMT "%p+%zx"
@@ -251,7 +289,9 @@ static inline void intf_init ( struct interface *intf,
  * @v intf             Object interface
  * @ret args           printf() argument list corresponding to INTF_FMT
  */
-#define INTF_DBG( intf ) intf_object ( intf ), (intf)->desc->offset
+#define INTF_DBG( intf )                                               \
+       intf_object ( intf_origin ( intf ) ),                           \
+       intf_origin ( intf )->desc->offset
 
 /** printf() format string for INTF_INTF_DBG() */
 #define INTF_INTF_FMT INTF_FMT "->" INTF_FMT
@@ -273,7 +313,7 @@ static inline void intf_init ( struct interface *intf,
 static inline void intf_reinit ( struct interface *intf ) {
 
        /* Restore original interface descriptor */
-       intf->desc = intf->original;
+       intf->desc = intf->original.desc;
 }
 
 #endif /* _IPXE_INTERFACE_H */