[xferbuf] Generalise to handle umalloc()-based buffers

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

src/core/xferbuf.c

@@ -28,6 +28,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <errno.h>
 #include <ipxe/xfer.h>
 #include <ipxe/iobuf.h>
+#include <ipxe/umalloc.h>
+#include <ipxe/profile.h>
 #include <ipxe/xferbuf.h>
 
 /** @file
@@ -36,14 +38,26 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  *
  */
 
+/** Data delivery profiler */
+static struct profiler xferbuf_deliver_profiler __profiler =
+	{ .name = "xferbuf.deliver" };
+
+/** Data write profiler */
+static struct profiler xferbuf_write_profiler __profiler =
+	{ .name = "xferbuf.write" };
+
+/** Data read profiler */
+static struct profiler xferbuf_read_profiler __profiler =
+	{ .name = "xferbuf.read" };
+
 /**
- * Finish using data transfer buffer
+ * Free data transfer buffer
  *
  * @v xferbuf		Data transfer buffer
  */
-void xferbuf_done ( struct xfer_buffer *xferbuf ) {
+void xferbuf_free ( struct xfer_buffer *xferbuf ) {
-	free ( xferbuf->data );
+
-	xferbuf->data = NULL;
+	xferbuf->op->realloc ( xferbuf, 0 );
 	xferbuf->len = 0;
 	xferbuf->pos = 0;
 }
@@ -56,25 +70,77 @@ void xferbuf_done ( struct xfer_buffer *xferbuf ) {
  * @ret rc		Return status code
  */
 static int xferbuf_ensure_size ( struct xfer_buffer *xferbuf, size_t len ) {
-	void *new_data;
+	int rc;
 
 	/* If buffer is already large enough, do nothing */
 	if ( len <= xferbuf->len )
 		return 0;
 
 	/* Extend buffer */
-	new_data = realloc ( xferbuf->data, len );
+	if ( ( rc = xferbuf->op->realloc ( xferbuf, len ) ) != 0 ) {
-	if ( ! new_data ) {
 		DBGC ( xferbuf, "XFERBUF %p could not extend buffer to "
-		       "%zd bytes\n", xferbuf, len );
+		       "%zd bytes: %s\n", xferbuf, len, strerror ( rc ) );
-		return -ENOSPC;
+		return rc;
 	}
-	xferbuf->data = new_data;
 	xferbuf->len = len;
 
 	return 0;
 }
 
+/**
+ * Write to data transfer buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to write
+ * @v len		Length of data
+ */
+int xferbuf_write ( struct xfer_buffer *xferbuf, size_t offset,
+		    const void *data, size_t len ) {
+	size_t max_len;
+	int rc;
+
+	/* Check for overflow */
+	max_len = ( offset + len );
+	if ( max_len < offset )
+		return -EOVERFLOW;
+
+	/* Ensure buffer is large enough to contain this write */
+	if ( ( rc = xferbuf_ensure_size ( xferbuf, max_len ) ) != 0 )
+		return rc;
+
+	/* Copy data to buffer */
+	profile_start ( &xferbuf_write_profiler );
+	xferbuf->op->write ( xferbuf, offset, data, len );
+	profile_stop ( &xferbuf_write_profiler );
+
+	return 0;
+}
+
+/**
+ * Read from data transfer buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to write
+ * @v len		Length of data
+ */
+int xferbuf_read ( struct xfer_buffer *xferbuf, size_t offset,
+		   void *data, size_t len ) {
+
+	/* Check that read is within buffer range */
+	if ( ( offset > xferbuf->len ) ||
+	     ( len > ( xferbuf->len - offset ) ) )
+		return -ENOENT;
+
+	/* Copy data from buffer */
+	profile_start ( &xferbuf_read_profiler );
+	xferbuf->op->read ( xferbuf, offset, data, len );
+	profile_stop ( &xferbuf_read_profiler );
+
+	return 0;
+}
+
 /**
  * Add received data to data transfer buffer
  *
@@ -85,28 +151,135 @@ static int xferbuf_ensure_size ( struct xfer_buffer *xferbuf, size_t len ) {
  */
 int xferbuf_deliver ( struct xfer_buffer *xferbuf, struct io_buffer *iobuf,
 		      struct xfer_metadata *meta ) {
-	size_t len;
+	size_t len = iob_len ( iobuf );
-	size_t max;
+	size_t pos;
 	int rc;
 
-	/* Calculate new buffer position */
+	/* Start profiling */
-	if ( meta->flags & XFER_FL_ABS_OFFSET )
+	profile_start ( &xferbuf_deliver_profiler );
-		xferbuf->pos = 0;
-	xferbuf->pos += meta->offset;
 
-	/* Ensure that we have enough buffer space for this data */
+	/* Calculate new buffer position */
-	len = iob_len ( iobuf );
+	pos = xferbuf->pos;
-	max = ( xferbuf->pos + len );
+	if ( meta->flags & XFER_FL_ABS_OFFSET )
-	if ( ( rc = xferbuf_ensure_size ( xferbuf, max ) ) != 0 )
+		pos = 0;
+	pos += meta->offset;
+
+	/* Write data to buffer */
+	if ( ( rc = xferbuf_write ( xferbuf, pos, iobuf->data, len ) ) != 0 )
 		goto done;
 
-	/* Copy data to buffer */
-	memcpy ( ( xferbuf->data + xferbuf->pos ), iobuf->data, len );
-
 	/* Update current buffer position */
-	xferbuf->pos += len;
+	xferbuf->pos = ( pos + len );
 
  done:
 	free_iob ( iobuf );
+	profile_stop ( &xferbuf_deliver_profiler );
 	return rc;
 }
+
+/**
+ * Reallocate malloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v len		New length (or zero to free buffer)
+ * @ret rc		Return status code
+ */
+static int xferbuf_malloc_realloc ( struct xfer_buffer *xferbuf, size_t len ) {
+	void *new_data;
+
+	new_data = realloc ( xferbuf->data, len );
+	if ( ! new_data )
+		return -ENOSPC;
+	xferbuf->data = new_data;
+	return 0;
+}
+
+/**
+ * Write data to malloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to copy
+ * @v len		Length of data
+ */
+static void xferbuf_malloc_write ( struct xfer_buffer *xferbuf, size_t offset,
+				   const void *data, size_t len ) {
+
+	memcpy ( ( xferbuf->data + offset ), data, len );
+}
+
+/**
+ * Read data from malloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to read
+ * @v len		Length of data
+ */
+static void xferbuf_malloc_read ( struct xfer_buffer *xferbuf, size_t offset,
+				  void *data, size_t len ) {
+
+	memcpy ( data, ( xferbuf->data + offset ), len );
+}
+
+/** malloc()-based data buffer operations */
+struct xfer_buffer_operations xferbuf_malloc_operations = {
+	.realloc = xferbuf_malloc_realloc,
+	.write = xferbuf_malloc_write,
+	.read = xferbuf_malloc_read,
+};
+
+/**
+ * Reallocate umalloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v len		New length (or zero to free buffer)
+ * @ret rc		Return status code
+ */
+static int xferbuf_umalloc_realloc ( struct xfer_buffer *xferbuf, size_t len ) {
+	userptr_t *udata = xferbuf->data;
+	userptr_t new_udata;
+
+	new_udata = urealloc ( *udata, len );
+	if ( ! new_udata )
+		return -ENOSPC;
+	*udata = new_udata;
+	return 0;
+}
+
+/**
+ * Write data to umalloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to copy
+ * @v len		Length of data
+ */
+static void xferbuf_umalloc_write ( struct xfer_buffer *xferbuf, size_t offset,
+				    const void *data, size_t len ) {
+	userptr_t *udata = xferbuf->data;
+
+	copy_to_user ( *udata, offset, data, len );
+}
+
+/**
+ * Read data from umalloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to read
+ * @v len		Length of data
+ */
+static void xferbuf_umalloc_read ( struct xfer_buffer *xferbuf, size_t offset,
+				   void *data, size_t len ) {
+	userptr_t *udata = xferbuf->data;
+
+	copy_from_user ( data, *udata, offset, len );
+}
+
+/** umalloc()-based data buffer operations */
+struct xfer_buffer_operations xferbuf_umalloc_operations = {
+	.realloc = xferbuf_umalloc_realloc,
+	.write = xferbuf_umalloc_write,
+	.read = xferbuf_umalloc_read,
+};

src/include/ipxe/xferbuf.h

@@ -11,6 +11,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stdint.h>
 #include <ipxe/iobuf.h>
+#include <ipxe/uaccess.h>
 #include <ipxe/xfer.h>
 
 /** A data transfer buffer */
@@ -21,9 +22,77 @@ struct xfer_buffer {
 	size_t len;
 	/** Current offset within data */
 	size_t pos;
+	/** Data transfer buffer operations */
+	struct xfer_buffer_operations *op;
 };
 
-extern void xferbuf_done ( struct xfer_buffer *xferbuf );
+/** Data transfer buffer operations */
+struct xfer_buffer_operations {
+	/** Reallocate data buffer
+	 *
+	 * @v xferbuf		Data transfer buffer
+	 * @v len		New length (or zero to free buffer)
+	 * @ret rc		Return status code
+	 */
+	int ( * realloc ) ( struct xfer_buffer *xferbuf, size_t len );
+	/** Write data to buffer
+	 *
+	 * @v xferbuf		Data transfer buffer
+	 * @v offset		Starting offset
+	 * @v data		Data to write
+	 * @v len		Length of data
+	 *
+	 * This call is simply a wrapper for the appropriate
+	 * memcpy()-like operation: the caller is responsible for
+	 * ensuring that the write does not exceed the buffer length.
+	 */
+	void ( * write ) ( struct xfer_buffer *xferbuf, size_t offset,
+			   const void *data, size_t len );
+	/** Read data from buffer
+	 *
+	 * @v xferbuf		Data transfer buffer
+	 * @v offset		Starting offset
+	 * @v data		Data to read
+	 * @v len		Length of data
+	 *
+	 * This call is simply a wrapper for the appropriate
+	 * memcpy()-like operation: the caller is responsible for
+	 * ensuring that the read does not exceed the buffer length.
+	 */
+	void ( * read ) ( struct xfer_buffer *xferbuf, size_t offset,
+			  void *data, size_t len );
+};
+
+extern struct xfer_buffer_operations xferbuf_malloc_operations;
+extern struct xfer_buffer_operations xferbuf_umalloc_operations;
+
+/**
+ * Initialise malloc()-based data transfer buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ */
+static inline __attribute__ (( always_inline )) void
+xferbuf_malloc_init ( struct xfer_buffer *xferbuf ) {
+	xferbuf->op = &xferbuf_malloc_operations;
+}
+
+/**
+ * Initialise umalloc()-based data transfer buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v data		User pointer
+ */
+static inline __attribute__ (( always_inline )) void
+xferbuf_umalloc_init ( struct xfer_buffer *xferbuf, userptr_t *data ) {
+	xferbuf->data = data;
+	xferbuf->op = &xferbuf_umalloc_operations;
+}
+
+extern void xferbuf_free ( struct xfer_buffer *xferbuf );
+extern int xferbuf_write ( struct xfer_buffer *xferbuf, size_t offset,
+			   const void *data, size_t len );
+extern int xferbuf_read ( struct xfer_buffer *xferbuf, size_t offset,
+			  void *data, size_t len );
 extern int xferbuf_deliver ( struct xfer_buffer *xferbuf,
 			     struct io_buffer *iobuf,
 			     struct xfer_metadata *meta );

src/net/validator.c

@@ -83,7 +83,7 @@ static void validator_free ( struct refcnt *refcnt ) {
 	DBGC2 ( validator, "VALIDATOR %p freed\n", validator );
 	x509_chain_put ( validator->chain );
 	ocsp_put ( validator->ocsp );
-	xferbuf_done ( &validator->buffer );
+	xferbuf_free ( &validator->buffer );
 	free ( validator );
 }
 
@@ -392,7 +392,7 @@ static void validator_xfer_close ( struct validator *validator, int rc ) {
 		goto err_append;
 
 	/* Free downloaded data */
-	xferbuf_done ( &validator->buffer );
+	xferbuf_free ( &validator->buffer );
 
 	/* Resume validation process */
 	process_add ( &validator->process );
@@ -557,6 +557,7 @@ int create_validator ( struct interface *job, struct x509_chain *chain ) {
 	process_init ( &validator->process, &validator_process_desc,
 		       &validator->refcnt );
 	validator->chain = x509_chain_get ( chain );
+	xferbuf_malloc_init ( &validator->buffer );
 
 	/* Attach parent interface, mortalise self, and return */
 	intf_plug_plug ( &validator->job, job );