[interface] Convert all data-xfer interfaces to generic interfaces

Remove data-xfer as an interface type, and replace data-xfer
interfaces with generic interfaces supporting the data-xfer methods.

Filter interfaces (as used by the TLS layer) are handled using the
generic pass-through interface capability.  A side-effect of this is
that deliver_raw() no longer exists as a data-xfer method.  (In
practice this doesn't lose any efficiency, since there are no
instances within the current codebase where xfer_deliver_raw() is used
to pass data to an interface supporting the deliver_raw() method.)

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

9 files changed, 60 insertions, 317 deletions

diff --git a/src/include/ipxe/filter.h b/src/include/ipxe/filter.h
deleted file mode 100644
index b23a98d91..000000000
--- a/src/include/ipxe/filter.h
+++ /dev/null
@@ -1,75 +0,0 @@
-#ifndef _IPXE_FILTER_H
-#define _IPXE_FILTER_H
-
-/** @file
- *
- * Data transfer filters
- *
- */
-
-FILE_LICENCE ( GPL2_OR_LATER );
-
-#include <stddef.h>
-#include <ipxe/xfer.h>
-
-/**
- * Half of a data transfer filter
- *
- * Embed two of these structures within a structure implementing a
- * data transfer filter, and intialise with filter_init().  You can
- * then use the filter_xxx() methods as the data transfer interface
- * methods as required.
- */
-struct xfer_filter_half {
-	/** Data transfer interface */
-	struct xfer_interface xfer;
-	/** Other half of the data transfer filter */
-	struct xfer_filter_half *other;
-};
-
-/**
- * Get data transfer interface for the other half of a data transfer filter
- *
- * @v xfer		Data transfer interface
- * @ret other		Other half's data transfer interface
- */
-static inline __attribute__ (( always_inline )) struct xfer_interface *
-filter_other_half ( struct xfer_interface *xfer ) {
-	struct xfer_filter_half *half = 
-		container_of ( xfer, struct xfer_filter_half, xfer );
-	return &half->other->xfer;
-}
-
-extern void filter_close ( struct xfer_interface *xfer, int rc );
-extern int filter_vredirect ( struct xfer_interface *xfer, int type,
-			      va_list args );
-extern size_t filter_window ( struct xfer_interface *xfer );
-extern struct io_buffer * filter_alloc_iob ( struct xfer_interface *xfer,
-					     size_t len );
-extern int filter_deliver_iob ( struct xfer_interface *xfer,
-				struct io_buffer *iobuf,
-				struct xfer_metadata *meta );
-extern int filter_deliver_raw ( struct xfer_interface *xfer, const void *data,
-				size_t len );
-
-/**
- * Initialise a data transfer filter
- *
- * @v left		"Left" half of the filter
- * @v left_op		Data transfer interface operations for "left" half
- * @v right		"Right" half of the filter
- * @v right_op		Data transfer interface operations for "right" half
- * @v refcnt		Containing object reference counter, or NULL
- */
-static inline void filter_init ( struct xfer_filter_half *left,
-				 struct xfer_interface_operations *left_op,
-				 struct xfer_filter_half *right,
-				 struct xfer_interface_operations *right_op,
-				 struct refcnt *refcnt ) {
-	xfer_init ( &left->xfer, left_op, refcnt );
-	xfer_init ( &right->xfer, right_op, refcnt );
-	left->other = right;
-	right->other = left;
-}
-
-#endif /* _IPXE_FILTER_H */
diff --git a/src/include/ipxe/http.h b/src/include/ipxe/http.h
index 97014d1f4..d8f4ca5ac 100644
--- a/src/include/ipxe/http.h
+++ b/src/include/ipxe/http.h
@@ -15,9 +15,9 @@ FILE_LICENCE ( GPL2_OR_LATER );
 /** HTTPS default port */
 #define HTTPS_PORT 443
 
-extern int http_open_filter ( struct xfer_interface *xfer, struct uri *uri,
+extern int http_open_filter ( struct interface *xfer, struct uri *uri,
 			      unsigned int default_port,
-			      int ( * filter ) ( struct xfer_interface *,
-						 struct xfer_interface ** ) );
+			      int ( * filter ) ( struct interface *,
+						 struct interface ** ) );
 
 #endif /* _IPXE_HTTP_H */
diff --git a/src/include/ipxe/ib_cmrc.h b/src/include/ipxe/ib_cmrc.h
index c02b15dcb..4f2eae69e 100644
--- a/src/include/ipxe/ib_cmrc.h
+++ b/src/include/ipxe/ib_cmrc.h
@@ -12,7 +12,7 @@ FILE_LICENCE ( BSD2 );
 #include <ipxe/infiniband.h>
 #include <ipxe/xfer.h>
 
-extern int ib_cmrc_open ( struct xfer_interface *xfer,
+extern int ib_cmrc_open ( struct interface *xfer,
 			  struct ib_device *ibdev,
 			  struct ib_gid *dgid,
 			  struct ib_gid_half *service_id );
diff --git a/src/include/ipxe/iscsi.h b/src/include/ipxe/iscsi.h
index c5e725154..a604e1e4f 100644
--- a/src/include/ipxe/iscsi.h
+++ b/src/include/ipxe/iscsi.h
@@ -498,7 +498,7 @@ struct iscsi_session {
 	struct refcnt refcnt;
 
 	/** Transport-layer socket */
-	struct xfer_interface socket;
+	struct interface socket;
 
 	/** Target address */
 	char *target_address;
diff --git a/src/include/ipxe/open.h b/src/include/ipxe/open.h
index 04e37e0e6..c000990c0 100644
--- a/src/include/ipxe/open.h
+++ b/src/include/ipxe/open.h
@@ -13,8 +13,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/tables.h>
 #include <ipxe/socket.h>
 
-struct xfer_interface;
 struct uri;
+struct interface;
 
 /** Location types */
 enum {
@@ -53,11 +53,11 @@ struct uri_opener {
 	const char *scheme;
 	/** Open URI
 	 *
-	 * @v xfer		Data transfer interface
+	 * @v intf		Object interface
 	 * @v uri		URI
 	 * @ret rc		Return status code
 	 */
-	int ( * open ) ( struct xfer_interface *xfer, struct uri *uri );
+	int ( * open ) ( struct interface *intf, struct uri *uri );
 };
 
 /** URI opener table */
@@ -74,12 +74,12 @@ struct socket_opener {
 	int family;
 	/** Open socket
 	 *
-	 * @v xfer		Data transfer interface
+	 * @v intf		Object interface
 	 * @v peer		Peer socket address
 	 * @v local		Local socket address, or NULL
 	 * @ret rc		Return status code
 	 */
-	int ( * open ) ( struct xfer_interface *xfer, struct sockaddr *peer,
+	int ( * open ) ( struct interface *intf, struct sockaddr *peer,
 			 struct sockaddr *local );
 };
 
@@ -89,17 +89,17 @@ struct socket_opener {
 /** Register a socket opener */
 #define __socket_opener __table_entry ( SOCKET_OPENERS, 01 )
 
-extern int xfer_open_uri ( struct xfer_interface *xfer, struct uri *uri );
-extern int xfer_open_uri_string ( struct xfer_interface *xfer,
+extern int xfer_open_uri ( struct interface *intf, struct uri *uri );
+extern int xfer_open_uri_string ( struct interface *intf,
 				  const char *uri_string );
-extern int xfer_open_named_socket ( struct xfer_interface *xfer,
-				    int semantics, struct sockaddr *peer,
-				    const char *name, struct sockaddr *local );
-extern int xfer_open_socket ( struct xfer_interface *xfer, int semantics,
+extern int xfer_open_named_socket ( struct interface *intf, int semantics,
+				    struct sockaddr *peer, const char *name,
+				    struct sockaddr *local );
+extern int xfer_open_socket ( struct interface *intf, int semantics,
 			      struct sockaddr *peer, struct sockaddr *local );
-extern int xfer_vopen ( struct xfer_interface *xfer, int type, va_list args );
-extern int xfer_open ( struct xfer_interface *xfer, int type, ... );
-extern int xfer_vreopen ( struct xfer_interface *xfer, int type,
+extern int xfer_vopen ( struct interface *intf, int type, va_list args );
+extern int xfer_open ( struct interface *intf, int type, ... );
+extern int xfer_vreopen ( struct interface *intf, int type,
 			  va_list args );
 
 #endif /* _IPXE_OPEN_H */
diff --git a/src/include/ipxe/srp.h b/src/include/ipxe/srp.h
index 7c0ff4c93..e519838a4 100644
--- a/src/include/ipxe/srp.h
+++ b/src/include/ipxe/srp.h
@@ -832,7 +832,7 @@ struct srp_device {
 	struct scsi_command *command;
 
 	/** Underlying data transfer interface */
-	struct xfer_interface socket;
+	struct interface socket;
 
 	/** Transport type */
 	struct srp_transport_type *transport;
diff --git a/src/include/ipxe/tls.h b/src/include/ipxe/tls.h
index 2cc36dd7c..94cd322c8 100644
--- a/src/include/ipxe/tls.h
+++ b/src/include/ipxe/tls.h
@@ -11,7 +11,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 #include <stdint.h>
 #include <ipxe/refcnt.h>
-#include <ipxe/filter.h>
+#include <ipxe/interface.h>
 #include <ipxe/process.h>
 #include <ipxe/crypto.h>
 #include <ipxe/md5.h>
@@ -134,9 +134,9 @@ struct tls_session {
 	struct refcnt refcnt;
 
 	/** Plaintext stream */
-	struct xfer_filter_half plainstream;
+	struct interface plainstream;
 	/** Ciphertext stream */
-	struct xfer_filter_half cipherstream;
+	struct interface cipherstream;
 
 	/** Current TX cipher specification */
 	struct tls_cipherspec tx_cipherspec;
@@ -181,7 +181,7 @@ struct tls_session {
 	void *rx_data;
 };
 
-extern int add_tls ( struct xfer_interface *xfer,
-		     struct xfer_interface **next );
+extern int add_tls ( struct interface *xfer,
+		     struct interface **next );
 
 #endif /* _IPXE_TLS_H */
diff --git a/src/include/ipxe/udp.h b/src/include/ipxe/udp.h
index 5e55c5e8c..c18a29723 100644
--- a/src/include/ipxe/udp.h
+++ b/src/include/ipxe/udp.h
@@ -16,7 +16,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/tcpip.h>
 #include <ipxe/if_ether.h>
 
-struct xfer_interface;
+struct interface;
+struct sockaddr;
 
 /**
  * UDP constants
@@ -40,8 +41,8 @@ struct udp_header {
 	uint16_t chksum;
 };
 
-extern int udp_open_promisc ( struct xfer_interface *xfer );
-extern int udp_open ( struct xfer_interface *xfer, struct sockaddr *peer,
+extern int udp_open_promisc ( struct interface *xfer );
+extern int udp_open ( struct interface *xfer, struct sockaddr *peer,
 		      struct sockaddr *local );
 
 #endif /* _IPXE_UDP_H */
diff --git a/src/include/ipxe/xfer.h b/src/include/ipxe/xfer.h
index 8a3f9bb1c..67da15f16 100644
--- a/src/include/ipxe/xfer.h
+++ b/src/include/ipxe/xfer.h
@@ -12,88 +12,11 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <stddef.h>
 #include <stdarg.h>
 #include <ipxe/interface.h>
-#include <ipxe/iobuf.h>
 
-struct xfer_interface;
 struct xfer_metadata;
-
-/** Data transfer interface operations */
-struct xfer_interface_operations {
-	/** Close interface
-	 *
-	 * @v xfer		Data transfer interface
-	 * @v rc		Reason for close
-	 */
-	void ( * close ) ( struct xfer_interface *xfer, int rc );
-	/** Redirect to new location
-	 *
-	 * @v xfer		Data transfer interface
-	 * @v type		New location type
-	 * @v args		Remaining arguments depend upon location type
-	 * @ret rc		Return status code
-	 */
-	int ( * vredirect ) ( struct xfer_interface *xfer, int type,
-			      va_list args );
-	/** Check flow control window
-	 *
-	 * @v xfer		Data transfer interface
-	 * @ret len		Length of window
-	 *
-	 * Flow control is regarded as advisory but not mandatory.
-	 * Users who have control over their own rate of data
-	 * generation should perform a flow control check before
-	 * generating new data.  Users who have no control (such as
-	 * NIC drivers or filter layers) are not obliged to check.
-	 *
-	 * Data transfer interfaces must be prepared to accept
-	 * datagrams even if they are advertising a window of zero
-	 * bytes.
-	 */
-	size_t ( * window ) ( struct xfer_interface *xfer );
-	/** Allocate I/O buffer
-	 *
-	 * @v xfer		Data transfer interface
-	 * @v len		I/O buffer payload length
-	 * @ret iobuf		I/O buffer
-	 */
-	struct io_buffer * ( * alloc_iob ) ( struct xfer_interface *xfer,
-					     size_t len );
-	/** Deliver datagram as I/O buffer with metadata
-	 *
-	 * @v xfer		Data transfer interface
-	 * @v iobuf		Datagram I/O buffer
-	 * @v meta		Data transfer metadata
-	 * @ret rc		Return status code
-	 *
-	 * A data transfer interface that wishes to support only raw
-	 * data delivery should set this method to
-	 * xfer_deliver_as_raw().
-	 */
-	int ( * deliver_iob ) ( struct xfer_interface *xfer,
-				struct io_buffer *iobuf,
-				struct xfer_metadata *meta );
-	/** Deliver datagram as raw data
-	 *
-	 * @v xfer		Data transfer interface
-	 * @v data		Data buffer
-	 * @v len		Length of data buffer
-	 * @ret rc		Return status code
-	 *
-	 * A data transfer interface that wishes to support only I/O
-	 * buffer delivery should set this method to
-	 * xfer_deliver_as_iob().
-	 */
-	int ( * deliver_raw ) ( struct xfer_interface *xfer,
-				const void *data, size_t len );
-};
-
-/** A data transfer interface */
-struct xfer_interface {
-	/** Generic object communication interface */
-	struct interface intf;
-	/** Operations for received messages */
-	struct xfer_interface_operations *op;
-};
+struct io_buffer;
+struct sockaddr;
+struct net_device;
 
 /** Basis positions for seek() events */
 enum seek_whence {
@@ -132,146 +55,40 @@ whence_text ( int whence ) {
 	}
 }
 
-extern struct xfer_interface null_xfer;
-extern struct xfer_interface_operations null_xfer_ops;
+/* Data transfer interface operations */
 
-extern void xfer_close ( struct xfer_interface *xfer, int rc );
-extern int xfer_vredirect ( struct xfer_interface *xfer, int type,
+extern int xfer_vredirect ( struct interface *intf, int type,
 			    va_list args );
-extern int xfer_redirect ( struct xfer_interface *xfer, int type, ... );
-extern size_t xfer_window ( struct xfer_interface *xfer );
-extern struct io_buffer * xfer_alloc_iob ( struct xfer_interface *xfer,
-					   size_t len );
-extern int xfer_deliver_iob ( struct xfer_interface *xfer,
-			      struct io_buffer *iobuf );
-extern int xfer_deliver_iob_meta ( struct xfer_interface *xfer,
-				   struct io_buffer *iobuf,
-				   struct xfer_metadata *meta );
-extern int xfer_deliver_raw ( struct xfer_interface *xfer,
-			      const void *data, size_t len );
-extern int xfer_vprintf ( struct xfer_interface *xfer,
-			  const char *format, va_list args );
-extern int __attribute__ (( format ( printf, 2, 3 ) ))
-xfer_printf ( struct xfer_interface *xfer, const char *format, ... );
-extern int xfer_seek ( struct xfer_interface *xfer, off_t offset, int whence );
-
-extern void ignore_xfer_close ( struct xfer_interface *xfer, int rc );
-extern int ignore_xfer_vredirect ( struct xfer_interface *xfer,
-				   int type, va_list args );
-extern size_t unlimited_xfer_window ( struct xfer_interface *xfer );
-extern size_t no_xfer_window ( struct xfer_interface *xfer );
-extern struct io_buffer * default_xfer_alloc_iob ( struct xfer_interface *xfer,
-						   size_t len );
-extern int xfer_deliver_as_raw ( struct xfer_interface *xfer,
-				 struct io_buffer *iobuf,
-				 struct xfer_metadata *meta );
-extern int xfer_deliver_as_iob ( struct xfer_interface *xfer,
-				 const void *data, size_t len );
-extern int ignore_xfer_deliver_raw ( struct xfer_interface *xfer,
-				     const void *data __unused, size_t len );
-
-/**
- * Initialise a data transfer interface
- *
- * @v xfer		Data transfer interface
- * @v op		Data transfer interface operations
- * @v refcnt		Containing object reference counter, or NULL
- */
-static inline void xfer_init ( struct xfer_interface *xfer,
-			       struct xfer_interface_operations *op,
-			       struct refcnt *refcnt ) {
-	xfer->intf.dest = &null_xfer.intf;
-	xfer->intf.refcnt = refcnt;
-	xfer->op = op;
-}
-
-/**
- * Initialise a static data transfer interface
- *
- * @v operations		Data transfer interface operations
- */
-#define XFER_INIT( operations ) {			\
-		.intf = {				\
-			.dest = &null_xfer.intf,	\
-			.refcnt = NULL,			\
-		},					\
-		.op = operations,			\
-	}
+#define xfer_vredirect_TYPE( object_type ) \
+	typeof ( int ( object_type, int type, va_list args ) )
 
-/**
- * Get data transfer interface from generic object communication interface
- *
- * @v intf		Generic object communication interface
- * @ret xfer		Data transfer interface
- */
-static inline __attribute__ (( always_inline )) struct xfer_interface *
-intf_to_xfer ( struct interface *intf ) {
-	return container_of ( intf, struct xfer_interface, intf );
-}
-
-/**
- * Get reference to destination data transfer interface
- *
- * @v xfer		Data transfer interface
- * @ret dest		Destination interface
- */
-static inline __attribute__ (( always_inline )) struct xfer_interface *
-xfer_get_dest ( struct xfer_interface *xfer ) {
-	return intf_to_xfer ( intf_get ( xfer->intf.dest ) );
-}
+extern size_t xfer_window ( struct interface *intf );
+#define xfer_window_TYPE( object_type ) \
+	typeof ( size_t ( object_type ) )
 
-/**
- * Drop reference to data transfer interface
- *
- * @v xfer		Data transfer interface
- */
-static inline __attribute__ (( always_inline )) void
-xfer_put ( struct xfer_interface *xfer ) {
-	intf_put ( &xfer->intf );
-}
-
-/**
- * Plug a data transfer interface into a new destination interface
- *
- * @v xfer		Data transfer interface
- * @v dest		New destination interface
- */
-static inline __attribute__ (( always_inline )) void
-xfer_plug ( struct xfer_interface *xfer, struct xfer_interface *dest ) {
-	intf_plug ( &xfer->intf, &dest->intf );
-}
+extern struct io_buffer * xfer_alloc_iob ( struct interface *intf,
+					   size_t len );
+#define xfer_alloc_iob_TYPE( object_type ) \
+	typeof ( struct io_buffer * ( object_type, size_t len ) )
 
-/**
- * Plug two data transfer interfaces together
- *
- * @v a			Data transfer interface A
- * @v b			Data transfer interface B
- */
-static inline __attribute__ (( always_inline )) void
-xfer_plug_plug ( struct xfer_interface *a, struct xfer_interface *b ) {
-	intf_plug_plug ( &a->intf, &b->intf );
-}
+extern int xfer_deliver ( struct interface *intf,
+			  struct io_buffer *iobuf,
+			  struct xfer_metadata *meta );
+#define xfer_deliver_TYPE( object_type )			\
+	typeof ( int ( object_type, struct io_buffer *iobuf,	\
+		       struct xfer_metadata *meta ) )
 
-/**
- * Unplug a data transfer interface
- *
- * @v xfer		Data transfer interface
- */
-static inline __attribute__ (( always_inline )) void
-xfer_unplug ( struct xfer_interface *xfer ) {
-	intf_plug ( &xfer->intf, &null_xfer.intf );
-}
+/* Data transfer interface helper functions */
 
-/**
- * Stop using a data transfer interface
- *
- * @v xfer		Data transfer interface
- *
- * After calling this method, no further messages will be received via
- * the interface.
- */
-static inline void xfer_nullify ( struct xfer_interface *xfer ) {
-	xfer->op = &null_xfer_ops;
-};
+extern int xfer_redirect ( struct interface *xfer, int type, ... );
+extern int xfer_deliver_iob ( struct interface *intf,
+			      struct io_buffer *iobuf );
+extern int xfer_deliver_raw ( struct interface *intf,
+			      const void *data, size_t len );
+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 );
 
 #endif /* _IPXE_XFER_H */