[downloader] Update image URI in response to a redirection

Update the image's recorded URI when a download redirection occurs.
This ensures that URIs relative to a redirected download are resolved
correctly.

In particular, this allows for the use of relative URIs in scripts
that are themselves downloaded via a redirection, such as the HTTP 301
redirection used to fix up URIs pointing to directories but omitting
the trailing slash (e.g. "http://boot.ipxe.org/demo", which will be
redirected to "http://boot.ipxe.org/demo/").

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/core/downloader.c b/src/core/downloader.c
index d745f36170b37d54e33f4884cd7a751e5445bf14..ba678f868a92ee8b8da211f03b1d278eda30598e 100644 (file)
--- a/src/core/downloader.c
+++ b/src/core/downloader.c
@@ -136,9 +136,9 @@ static int downloader_progress ( struct downloader *downloader,
  * @v meta             Data transfer metadata
  * @ret rc             Return status code
  */
-static int downloader_xfer_deliver ( struct downloader *downloader,
-                                    struct io_buffer *iobuf,
-                                    struct xfer_metadata *meta ) {
+static int downloader_deliver ( struct downloader *downloader,
+                               struct io_buffer *iobuf,
+                               struct xfer_metadata *meta ) {
        int rc;
 
        /* Add data to buffer */
@@ -160,16 +160,51 @@ static int downloader_xfer_deliver ( struct downloader *downloader,
  * @ret xferbuf                Data transfer buffer, or NULL on error
  */
 static struct xfer_buffer *
-downloader_xfer_buffer ( struct downloader *downloader ) {
+downloader_buffer ( struct downloader *downloader ) {
 
        /* Provide direct access to underlying data transfer buffer */
        return &downloader->buffer;
 }
 
+/**
+ * Redirect data transfer interface
+ *
+ * @v downloader       Downloader
+ * @v type             New location type
+ * @v args             Remaining arguments depend upon location type
+ * @ret rc             Return status code
+ */
+static int downloader_vredirect ( struct downloader *downloader, int type,
+                                 va_list args ) {
+       va_list tmp;
+       struct uri *uri;
+       int rc;
+
+       /* Intercept redirects to a LOCATION_URI and update the image URI */
+       if ( type == LOCATION_URI ) {
+
+               /* Extract URI argument */
+               va_copy ( tmp, args );
+               uri = va_arg ( tmp, struct uri * );
+               va_end ( tmp );
+
+               /* Set image URI */
+               if ( ( rc = image_set_uri ( downloader->image, uri ) ) != 0 )
+                       return rc;
+       }
+
+       /* Redirect to new location */
+       if ( ( rc = xfer_vreopen ( &downloader->xfer, type, args ) ) != 0 )
+               return rc;
+
+       return 0;
+}
+
 /** Downloader data transfer interface operations */
 static struct interface_operation downloader_xfer_operations[] = {
-       INTF_OP ( xfer_deliver, struct downloader *, downloader_xfer_deliver ),
-       INTF_OP ( xfer_buffer, struct downloader *, downloader_xfer_buffer ),
+       INTF_OP ( xfer_deliver, struct downloader *, downloader_deliver ),
+       INTF_OP ( xfer_buffer, struct downloader *, downloader_buffer ),
+       INTF_OP ( xfer_vredirect, struct downloader *, downloader_vredirect ),
        INTF_OP ( intf_close, struct downloader *, downloader_finished ),
 };