[xfer] Generalise metadata "whence" field to "flags" field

iPXE has never supported SEEK_END; the usage of "whence" offers only
the options of SEEK_SET and SEEK_CUR and so is effectively a boolean
flag.  Further flags will be required to support additional metadata
required by the Fibre Channel network model, so repurpose the "whence"
field as a generic "flags" field.

xfer_seek() has always been used with SEEK_SET, so remove the "whence"
field altogether from its argument list.

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

diff --git a/src/arch/i386/interface/pxe/pxe_tftp.c b/src/arch/i386/interface/pxe/pxe_tftp.c
index 7eaa63e5474d8ce93c3067a10b0b4735d0bf8b47..7f0af7a61e1e2682af365984862dc51c0562223e 100644 (file)
--- a/src/arch/i386/interface/pxe/pxe_tftp.c
+++ b/src/arch/i386/interface/pxe/pxe_tftp.c
@@ -85,7 +85,7 @@ static int pxe_tftp_xfer_deliver ( struct pxe_tftp_connection *pxe_tftp,
        int rc = 0;
 
        /* Calculate new buffer position */
-       if ( meta->whence != SEEK_CUR )
+       if ( meta->flags & XFER_FL_ABS_OFFSET )
                pxe_tftp->offset = 0;
        pxe_tftp->offset += meta->offset;
 

diff --git a/src/core/downloader.c b/src/core/downloader.c
index 488c86d9c4ea7cf677ba3b405eb5deec52e666a3..3e21ee9a3f315057eeda984c6d5de666f031cd9c 100644 (file)
--- a/src/core/downloader.c
+++ b/src/core/downloader.c
@@ -160,7 +160,7 @@ static int downloader_xfer_deliver ( struct downloader *downloader,
        int rc;
 
        /* Calculate new buffer position */
-       if ( meta->whence != SEEK_CUR )
+       if ( meta->flags & XFER_FL_ABS_OFFSET )
                downloader->pos = 0;
        downloader->pos += meta->offset;
 

diff --git a/src/core/posix_io.c b/src/core/posix_io.c
index f7ca3f0dbd25449b86d31b30f67d977223ce1682..38bd727b0263d396407df178d81db8e3540f165d 100644 (file)
--- a/src/core/posix_io.c
+++ b/src/core/posix_io.c
@@ -105,7 +105,7 @@ static int posix_file_xfer_deliver ( struct posix_file *file,
                                     struct xfer_metadata *meta ) {
 
        /* Keep track of file position solely for the filesize */
-       if ( meta->whence != SEEK_CUR )
+       if ( meta->flags & XFER_FL_ABS_OFFSET )
                file->pos = 0;
        file->pos += meta->offset;
        if ( file->filesize < file->pos )

diff --git a/src/core/xfer.c b/src/core/xfer.c
index dce245f9ced6de58b76a019d50fc7178f1f06aa3..112adfcba0cfff3d009514268848bc4fa80e4f8a 100644 (file)
--- a/src/core/xfer.c
+++ b/src/core/xfer.c
@@ -276,18 +276,17 @@ int xfer_printf ( struct interface *intf, const char *format, ... ) {
  *
  * @v intf             Data transfer interface
  * @v offset           Offset to new position
- * @v whence           Basis for new position
  * @ret rc             Return status code
  */
-int xfer_seek ( struct interface *intf, off_t offset, int whence ) {
+int xfer_seek ( struct interface *intf, off_t offset ) {
        struct io_buffer *iobuf;
        struct xfer_metadata meta = {
+               .flags = XFER_FL_ABS_OFFSET,
                .offset = offset,
-               .whence = whence,
        };
 
-       DBGC ( INTF_COL ( intf ), "INTF " INTF_FMT " seek %s+%ld\n",
-              INTF_DBG ( intf ), whence_text ( whence ), offset );
+       DBGC ( INTF_COL ( intf ), "INTF " INTF_FMT " seek to %ld\n",
+              INTF_DBG ( intf ), offset );
 
        /* Allocate and send a zero-length data buffer */
        iobuf = xfer_alloc_iob ( intf, 0 );

diff --git a/src/include/ipxe/xfer.h b/src/include/ipxe/xfer.h
index 67da15f1647e380b0bae552eb6c6c2c5a3b13d65..21614284bb2dd99dd1d68e25a053ea7a5facf05d 100644 (file)
--- a/src/include/ipxe/xfer.h
+++ b/src/include/ipxe/xfer.h
@@ -18,21 +18,23 @@ struct io_buffer;
 struct sockaddr;
 struct net_device;
 
-/** Basis positions for seek() events */
-enum seek_whence {
-       SEEK_CUR = 0,
-       SEEK_SET,
-};
-
 /** Data transfer metadata */
 struct xfer_metadata {
-       /** Position of data within stream */
-       off_t offset;
-       /** Basis for data position
+       /** Flags
+        *
+        * This is the bitwise OR of zero or more @c XFER_FL_XXX
+        * constants.
+        */
+       unsigned int flags;
+       /** Offset of data within stream
         *
-        * Must be one of @c SEEK_CUR or @c SEEK_SET.
+        * This is an absolute offset if the @c XFER_FL_ABS_OFFSET
+        * flag is set, otherwise a relative offset.  (A freshly
+        * zeroed @c xfer_metadata structure therefore represents a
+        * relative offset of zero, i.e. no offset from the current
+        * position.)
         */
-       int whence;
+       off_t offset;
        /** Source socket address, or NULL */
        struct sockaddr *src;
        /** Destination socket address, or NULL */
@@ -41,19 +43,8 @@ struct xfer_metadata {
        struct net_device *netdev;
 };
 
-/**
- * Describe seek basis
- *
- * @v whence           Basis for new position
- */
-static inline __attribute__ (( always_inline )) const char *
-whence_text ( int whence ) {
-       switch ( whence ) {
-       case SEEK_CUR:  return "CUR";
-       case SEEK_SET:  return "SET";
-       default:        return "INVALID";
-       }
-}
+/** Offset is absolute */
+#define XFER_FL_ABS_OFFSET 0x0001
 
 /* Data transfer interface operations */
 
@@ -89,6 +80,6 @@ extern int xfer_vprintf ( struct interface *intf,
                          const char *format, va_list args );
 extern int __attribute__ (( format ( printf, 2, 3 ) ))
 xfer_printf ( struct interface *intf, const char *format, ... );
-extern int xfer_seek ( struct interface *intf, off_t offset, int whence );
+extern int xfer_seek ( struct interface *intf, off_t offset );
 
 #endif /* _IPXE_XFER_H */

diff --git a/src/net/tcp/http.c b/src/net/tcp/http.c
index 3b59ed9f276faea4f0f9eb265acf1f2ccb90d3f8..20f14e680898779331f4f30da35373dd6465599b 100644 (file)
--- a/src/net/tcp/http.c
+++ b/src/net/tcp/http.c
@@ -223,8 +223,8 @@ static int http_rx_content_length ( struct http_request *http,
        }
 
        /* Use seek() to notify recipient of filesize */
-       xfer_seek ( &http->xfer, http->content_length, SEEK_SET );
-       xfer_seek ( &http->xfer, 0, SEEK_SET );
+       xfer_seek ( &http->xfer, http->content_length );
+       xfer_seek ( &http->xfer, 0 );
 
        return 0;
 }

diff --git a/src/net/udp/slam.c b/src/net/udp/slam.c
index 84bb9cba3599706f485bbfa18b2d43de1cf31b16..026bc1797cbfae6fd233ba1ee01a3169c4a90914 100644 (file)
--- a/src/net/udp/slam.c
+++ b/src/net/udp/slam.c
@@ -462,7 +462,7 @@ static int slam_pull_header ( struct slam_request *slam,
        }
 
        /* Notify recipient of file size */
-       xfer_seek ( &slam->xfer, slam->total_bytes, SEEK_SET );
+       xfer_seek ( &slam->xfer, slam->total_bytes );
 
        return 0;
 }
@@ -526,7 +526,7 @@ static int slam_mc_socket_deliver ( struct slam_request *slam,
 
        /* Pass to recipient */
        memset ( &meta, 0, sizeof ( meta ) );
-       meta.whence = SEEK_SET;
+       meta.flags = XFER_FL_ABS_OFFSET;
        meta.offset = ( packet * slam->block_size );
        if ( ( rc = xfer_deliver ( &slam->xfer, iobuf, &meta ) ) != 0 )
                goto err;

diff --git a/src/net/udp/tftp.c b/src/net/udp/tftp.c
index 3bcd0a258c9cb5ae60dc5538b50201a05c5d43d3..e8223c99cd57f6b1083d9d1e5a1f70f639780170 100644 (file)
--- a/src/net/udp/tftp.c
+++ b/src/net/udp/tftp.c
@@ -269,8 +269,8 @@ static int tftp_presize ( struct tftp_request *tftp, size_t filesize ) {
        tftp->filesize = filesize;
 
        /* Notify recipient of file size */
-       xfer_seek ( &tftp->xfer, filesize, SEEK_SET );
-       xfer_seek ( &tftp->xfer, 0, SEEK_SET );
+       xfer_seek ( &tftp->xfer, filesize );
+       xfer_seek ( &tftp->xfer, 0 );
 
        /* Calculate expected number of blocks.  Note that files whose
         * length is an exact multiple of the blocksize will have a
@@ -854,7 +854,7 @@ static int tftp_rx_data ( struct tftp_request *tftp,
 
        /* Deliver data */
        memset ( &meta, 0, sizeof ( meta ) );
-       meta.whence = SEEK_SET;
+       meta.flags = XFER_FL_ABS_OFFSET;
        meta.offset = offset;
        if ( ( rc = xfer_deliver ( &tftp->xfer, iob_disown ( iobuf ),
                                   &meta ) ) != 0 ) {