/*
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <ipxe/iobuf.h>
#include <ipxe/xfer.h>
#include <ipxe/open.h>
/** @file
*
* Data transfer interfaces
*
*/
/**
* Dummy transfer metadata
*
* This gets passed to xfer_interface::deliver() and equivalents when
* no metadata is available.
*/
static struct xfer_metadata dummy_metadata;
/*****************************************************************************
*
* Data transfer interface operations
*
*/
/**
* Send redirection event
*
* @v intf Data transfer interface
* @v type New location type
* @v args Remaining arguments depend upon location type
* @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 *dest;
xfer_vredirect_TYPE ( void * ) *op =
intf_get_dest_op_no_passthru ( intf, xfer_vredirect, &dest );
void *object = intf_object ( dest );
int rc;
DBGC ( INTF_COL ( intf ), "INTF " INTF_INTF_FMT " redirect\n",
INTF_INTF_DBG ( intf, dest ) );
if ( op ) {
rc = op ( object, type, args );
} else {
/* Default is to reopen the interface as instructed,
* then send xfer_window_changed() messages to both
* new child and parent interfaces. Since our
* original child interface is likely to be closed and
* unplugged as a result of the call to
* xfer_vreopen(), we create a temporary interface in
* order to be able to send xfer_window_changed() to
* the parent.
*
* If redirection fails, then send intf_close() to the
* parent interface.
*/
intf_plug ( &tmp, dest );
rc = xfer_vreopen ( dest, type, args );
if ( rc == 0 ) {
xfer_window_changed ( dest );
xfer_window_changed ( &tmp );
} else {
intf_close ( &tmp, rc );
}
intf_unplug ( &tmp );
}
if ( rc != 0 ) {
DBGC ( INTF_COL ( intf ), "INTF " INTF_INTF_FMT " redirect "
"failed: %s\n", INTF_INTF_DBG ( intf, dest ),
strerror ( rc ) );
}
intf_put ( dest );
return rc;
}
/**
* Check flow control window
*
* @v intf Data transfer interface
* @ret len Length of window
*/
size_t xfer_window ( struct interface *intf ) {
struct interface *dest;
xfer_window_TYPE ( void * ) *op =
intf_get_dest_op ( intf, xfer_window, &dest );
void *object = intf_object ( dest );
size_t len;
if ( op ) {
len = op ( object );
} else {
/* Default is to provide an unlimited window */
len = ~( ( size_t ) 0 );
}
intf_put ( dest );
return len;
}
/**
* Report change of flow control window
*
* @v intf Data transfer interface
*
* Note that this method is used to indicate only unsolicited changes
* in the flow control window. In particular, this method must not be
* called as part of the response to xfer_deliver(), since that could
* easily lead to an infinite loop. Callers of xfer_deliver() should
* assume that the flow control window will have changed without
* generating an xfer_window_changed() message.
*/
void xfer_window_changed ( struct interface *intf ) {
intf_poke ( intf, xfer_window_changed );
}
/**
* Allocate I/O buffer
*
* @v intf Data transfer interface
* @v len I/O buffer payload length
* @ret iobuf I/O buffer
*/
struct io_buffer * xfer_alloc_iob ( struct interface *intf, size_t len ) {
struct interface *dest;
xfer_alloc_iob_TYPE ( void * ) *op =
intf_get_dest_op ( intf, xfer_alloc_iob, &dest );
void *object = intf_object ( dest );
struct io_buffer *iobuf;
DBGC ( INTF_COL ( intf ), "INTF " INTF_INTF_FMT " alloc_iob %zd\n",
INTF_INTF_DBG ( intf, dest ), len );
if ( op ) {
iobuf = op ( object, len );
} else {
/* Default is to allocate an I/O buffer with no
* reserved space.
*/
iobuf = alloc_iob ( len );
}
if ( ! iobuf ) {
DBGC ( INTF_COL ( intf ), "INTF " INTF_INTF_FMT " alloc_iob "
"failed\n", INTF_INTF_DBG ( intf, dest ) );
}
intf_put ( dest );
return iobuf;
}
/**
* Deliver datagram
*
* @v intf Data transfer interface
* @v iobuf Datagram I/O buffer
* @v meta Data transfer metadata
* @ret rc Return status code
*/
int xfer_deliver ( struct interface *intf,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
struct interface *dest;
xfer_deliver_TYPE ( void * ) *op =
intf_get_dest_op ( intf, xfer_deliver, &dest );
void *object = intf_object ( dest );
int rc;
DBGC ( INTF_COL ( intf ), "INTF " INTF_INTF_FMT " deliver %zd\n",
INTF_INTF_DBG ( intf, dest ), iob_len ( iobuf ) );
if ( op ) {
rc = op ( object, iobuf, meta );
} else {
/* Default is to discard the I/O buffer */
free_iob ( iobuf );
rc = -EPIPE;
}
if ( rc != 0 ) {
DBGC ( INTF_COL ( intf ), "INTF " INTF_INTF_FMT
" deliver failed: %s\n",
INTF_INTF_DBG ( intf, dest ), strerror ( rc ) );
}
intf_put ( dest );
return rc;
}
/*****************************************************************************
*
* Data transfer interface helper functions
*
*/
/**
* Send redirection event
*
* @v intf Data transfer interface
* @v type New location type
* @v ... Remaining arguments depend upon location type
* @ret rc Return status code
*/
int xfer_redirect ( struct interface *intf, int type, ... ) {
va_list args;
int rc;
va_start ( args, type );
rc = xfer_vredirect ( intf, type, args );
va_end ( args );
return rc;
}
/**
* Deliver datagram as I/O buffer without metadata
*
* @v intf Data transfer interface
* @v iobuf Datagram I/O buffer
* @ret rc Return status code
*/
int xfer_deliver_iob ( struct interface *intf, struct io_buffer *iobuf ) {
return xfer_deliver ( intf, iobuf, &dummy_metadata );
}
/**
* Deliver datagram as raw data
*
* @v intf Data transfer interface
* @v data Data
* @v len Length of data
* @v meta Data transfer metadata
* @ret rc Return status code
*/
int xfer_deliver_raw_meta ( struct interface *intf, const void *data,
size_t len, struct xfer_metadata *meta ) {
struct io_buffer *iobuf;
iobuf = xfer_alloc_iob ( intf, len );
if ( ! iobuf )
return -ENOMEM;
memcpy ( iob_put ( iobuf, len ), data, len );
return xfer_deliver ( intf, iobuf, meta );
}
/**
* Deliver datagram as raw data without metadata
*
* @v intf Data transfer interface
* @v data Data
* @v len Length of data
* @ret rc Return status code
*/
int xfer_deliver_raw ( struct interface *intf, const void *data, size_t len ) {
return xfer_deliver_raw_meta ( intf, data, len, &dummy_metadata );
}
/**
* Deliver formatted string
*
* @v intf Data transfer interface
* @v format Format string
* @v args Arguments corresponding to the format string
* @ret rc Return status code
*/
int xfer_vprintf ( struct interface *intf, const char *format,
va_list args ) {
va_list args_tmp;
char *buf;
int len;
int rc;
/* Create temporary string */
va_copy ( args_tmp, args );
len = vasprintf ( &buf, format, args );
va_end ( args_tmp );
if ( len < 0 ) {
rc = len;
goto err_asprintf;
}
/* Transmit string */
if ( ( rc = xfer_deliver_raw ( intf, buf, len ) ) != 0 )
goto err_deliver;
err_deliver:
free ( buf );
err_asprintf:
return rc;
}
/**
* Deliver formatted string
*
* @v intf Data transfer interface
* @v format Format string
* @v ... Arguments corresponding to the format string
* @ret rc Return status code
*/
int xfer_printf ( struct interface *intf, const char *format, ... ) {
va_list args;
int rc;
va_start ( args, format );
rc = xfer_vprintf ( intf, format, args );
va_end ( args );
return rc;
}
/**
* Seek to position
*
* @v intf Data transfer interface
* @v offset Offset to new position
* @ret rc Return status code
*/
int xfer_seek ( struct interface *intf, off_t offset ) {
struct io_buffer *iobuf;
struct xfer_metadata meta = {
.flags = XFER_FL_ABS_OFFSET,
.offset = 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 );
if ( ! iobuf )
return -ENOMEM;
return xfer_deliver ( intf, iobuf, &meta );
}
/**
* Check that data is delivered strictly in order
*
* @v meta Data transfer metadata
* @v pos Current position
* @v len Length of data
* @ret rc Return status code
*/
int xfer_check_order ( struct xfer_metadata *meta, size_t *pos, size_t len ) {
size_t new_pos;
/* Allow out-of-order zero-length packets (as used by xfer_seek()) */
if ( len == 0 )
return 0;
/* Calculate position of this delivery */
new_pos = *pos;
if ( meta->flags & XFER_FL_ABS_OFFSET )
new_pos = 0;
new_pos += meta->offset;
/* Fail if delivery position is not equal to current position */
if ( new_pos != *pos )
return -EPROTO;
/* Update current position */
*pos += len;
return 0;
}
