/*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <gpxe/xfer.h>
/** @file
*
* Data transfer interfaces
*
*/
/**
* Dummy transfer metadata
*
* This gets passed to xfer_interface::deliver_iob() and equivalents
* when no metadata is available.
*/
static struct xfer_metadata dummy_metadata;
/**
* Close data transfer interface
*
* @v xfer Data transfer interface
* @v rc Reason for close
*/
void xfer_close ( struct xfer_interface *xfer, int rc ) {
struct xfer_interface *dest = xfer_get_dest ( xfer );
DBGC ( xfer, "XFER %p->%p close\n", xfer, dest );
xfer_unplug ( xfer );
dest->op->close ( dest, rc );
xfer_put ( dest );
}
/**
* Send redirection event
*
* @v xfer 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 xfer_interface *xfer, int type, va_list args ) {
struct xfer_interface *dest = xfer_get_dest ( xfer );
int rc;
DBGC ( xfer, "XFER %p->%p redirect\n", xfer, dest );
rc = dest->op->vredirect ( dest, type, args );
if ( rc != 0 ) {
DBGC ( xfer, "XFER %p<-%p redirect: %s\n", xfer, dest,
strerror ( rc ) );
}
xfer_put ( dest );
return rc;
}
/**
* Send redirection event
*
* @v xfer Data transfer interface
* @v type New location type
* @v ... Remaining arguments depend upon location type
* @ret rc Return status code
*/
int xfer_redirect ( struct xfer_interface *xfer, int type, ... ) {
va_list args;
int rc;
va_start ( args, type );
rc = xfer_vredirect ( xfer, type, args );
va_end ( args );
return rc;
}
/**
* Check flow control window
*
* @v xfer Data transfer interface
* @ret len Length of window
*/
size_t xfer_window ( struct xfer_interface *xfer ) {
struct xfer_interface *dest = xfer_get_dest ( xfer );
size_t len;
len = dest->op->window ( dest );
xfer_put ( dest );
return len;
}
/**
* Allocate I/O buffer
*
* @v xfer Data transfer interface
* @v len I/O buffer payload length
* @ret iobuf I/O buffer
*/
struct io_buffer * xfer_alloc_iob ( struct xfer_interface *xfer, size_t len ) {
struct xfer_interface *dest = xfer_get_dest ( xfer );
struct io_buffer *iobuf;
DBGC ( xfer, "XFER %p->%p alloc_iob %zd\n", xfer, dest, len );
iobuf = dest->op->alloc_iob ( dest, len );
if ( ! iobuf ) {
DBGC ( xfer, "XFER %p<-%p alloc_iob failed\n", xfer, dest );
}
xfer_put ( dest );
return iobuf;
}
/**
* 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
*/
int xfer_deliver_iob_meta ( struct xfer_interface *xfer,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
struct xfer_interface *dest = xfer_get_dest ( xfer );
int rc;
DBGC ( xfer, "XFER %p->%p deliver_iob %zd\n", xfer, dest,
iob_len ( iobuf ) );
rc = dest->op->deliver_iob ( dest, iobuf, meta );
if ( rc != 0 ) {
DBGC ( xfer, "XFER %p<-%p deliver_iob: %s\n", xfer, dest,
strerror ( rc ) );
}
xfer_put ( dest );
return rc;
}
/**
* Deliver datagram as I/O buffer with metadata
*
* @v xfer Data transfer interface
* @v iobuf Datagram I/O buffer
* @ret rc Return status code
*/
int xfer_deliver_iob ( struct xfer_interface *xfer,
struct io_buffer *iobuf ) {
return xfer_deliver_iob_meta ( xfer, iobuf, &dummy_metadata );
}
/**
* Deliver datagram as raw data
*
* @v xfer Data transfer interface
* @v iobuf Datagram I/O buffer
* @ret rc Return status code
*/
int xfer_deliver_raw ( struct xfer_interface *xfer,
const void *data, size_t len ) {
struct xfer_interface *dest = xfer_get_dest ( xfer );
int rc;
DBGC ( xfer, "XFER %p->%p deliver_raw %p+%zd\n", xfer, dest,
data, len );
rc = dest->op->deliver_raw ( dest, data, len );
if ( rc != 0 ) {
DBGC ( xfer, "XFER %p<-%p deliver_raw: %s\n", xfer, dest,
strerror ( rc ) );
}
xfer_put ( dest );
return rc;
}
/**
* Deliver formatted string
*
* @v xfer Data transfer interface
* @v format Format string
* @v args Arguments corresponding to the format string
* @ret rc Return status code
*/
int xfer_vprintf ( struct xfer_interface *xfer, const char *format,
va_list args ) {
size_t len;
va_list args_tmp;
va_copy ( args_tmp, args );
len = vsnprintf ( NULL, 0, format, args );
{
char buf[len + 1];
vsnprintf ( buf, sizeof ( buf ), format, args_tmp );
va_end ( args_tmp );
return xfer_deliver_raw ( xfer, buf, len );
}
}
/**
* Deliver formatted string
*
* @v xfer Data transfer interface
* @v format Format string
* @v ... Arguments corresponding to the format string
* @ret rc Return status code
*/
int xfer_printf ( struct xfer_interface *xfer, const char *format, ... ) {
va_list args;
int rc;
va_start ( args, format );
rc = xfer_vprintf ( xfer, format, args );
va_end ( args );
return rc;
}
/**
* Seek to position
*
* @v xfer Data transfer interface
* @v offset Offset to new position
* @v whence Basis for new position
* @ret rc Return status code
*/
int xfer_seek ( struct xfer_interface *xfer, off_t offset, int whence ) {
struct io_buffer *iobuf;
struct xfer_metadata meta = {
.offset = offset,
.whence = whence,
};
DBGC ( xfer, "XFER %p seek %s+%ld\n", xfer,
whence_text ( whence ), offset );
/* Allocate and send a zero-length data buffer */
iobuf = xfer_alloc_iob ( xfer, 0 );
if ( ! iobuf )
return -ENOMEM;
return xfer_deliver_iob_meta ( xfer, iobuf, &meta );
}
/****************************************************************************
*
* Helper methods
*
* These functions are designed to be used as methods in the
* xfer_interface_operations table.
*
*/
/**
* Ignore close() event
*
* @v xfer Data transfer interface
* @v rc Reason for close
*/
void ignore_xfer_close ( struct xfer_interface *xfer __unused,
int rc __unused ) {
/* Nothing to do */
}
/**
* Ignore vredirect() event
*
* @v xfer Data transfer interface
* @v type New location type
* @v args Remaining arguments depend upon location type
* @ret rc Return status code
*/
int ignore_xfer_vredirect ( struct xfer_interface *xfer __unused,
int type __unused, va_list args __unused ) {
return 0;
}
/**
* Unlimited flow control window
*
* @v xfer Data transfer interface
* @ret len Length of window
*
* This handler indicates that the interface is always ready to accept
* data.
*/
size_t unlimited_xfer_window ( struct xfer_interface *xfer __unused ) {
return ~( ( size_t ) 0 );
}
/**
* No flow control window
*
* @v xfer Data transfer interface
* @ret len Length of window
*
* This handler indicates that the interface is never ready to accept
* data.
*/
size_t no_xfer_window ( struct xfer_interface *xfer __unused ) {
return 0;
}
/**
* Allocate I/O buffer
*
* @v xfer Data transfer interface
* @v len I/O buffer payload length
* @ret iobuf I/O buffer
*/
struct io_buffer *
default_xfer_alloc_iob ( struct xfer_interface *xfer __unused, size_t len ) {
return alloc_iob ( len );
}
/**
* Deliver datagram as raw data
*
* @v xfer Data transfer interface
* @v iobuf Datagram I/O buffer
* @v meta Data transfer metadata
* @ret rc Return status code
*
* This function is intended to be used as the deliver() method for
* data transfer interfaces that prefer to handle raw data.
*/
int xfer_deliver_as_raw ( struct xfer_interface *xfer,
struct io_buffer *iobuf,
struct xfer_metadata *meta __unused ) {
int rc;
rc = xfer->op->deliver_raw ( xfer, iobuf->data, iob_len ( iobuf ) );
free_iob ( iobuf );
return rc;
}
/**
* Deliver datagram as I/O buffer
*
* @v xfer Data transfer interface
* @v data Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*
* This function is intended to be used as the deliver_raw() method
* for data transfer interfaces that prefer to handle I/O buffers.
*/
int xfer_deliver_as_iob ( struct xfer_interface *xfer,
const void *data, size_t len ) {
struct io_buffer *iobuf;
iobuf = xfer->op->alloc_iob ( xfer, len );
if ( ! iobuf )
return -ENOMEM;
memcpy ( iob_put ( iobuf, len ), data, len );
return xfer->op->deliver_iob ( xfer, iobuf, &dummy_metadata );
}
/**
* Ignore datagram as raw data event
*
* @v xfer Data transfer interface
* @v data Data buffer
* @v len Length of data buffer
* @ret rc Return status code
*/
int ignore_xfer_deliver_raw ( struct xfer_interface *xfer,
const void *data __unused, size_t len ) {
DBGC ( xfer, "XFER %p %zd bytes delivered %s\n", xfer, len,
( ( xfer == &null_xfer ) ?
"before connection" : "after termination" ) );
return 0;
}
/** Null data transfer interface operations */
struct xfer_interface_operations null_xfer_ops = {
.close = ignore_xfer_close,
.vredirect = ignore_xfer_vredirect,
.window = unlimited_xfer_window,
.alloc_iob = default_xfer_alloc_iob,
.deliver_iob = xfer_deliver_as_raw,
.deliver_raw = ignore_xfer_deliver_raw,
};
/**
* Null data transfer interface
*
* This is the interface to which data transfer interfaces are
* connected when unplugged. It will never generate messages, and
* will silently absorb all received messages.
*/
struct xfer_interface null_xfer = XFER_INIT ( &null_xfer_ops );
