1 files changed, 355 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/core/posix_io.c b/contrib/syslinux-4.02/gpxe/src/core/posix_io.c
new file mode 100644
index 0000000..e6b1a0f
--- /dev/null
+++ b/contrib/syslinux-4.02/gpxe/src/core/posix_io.c
@@ -0,0 +1,355 @@
+/*
+ * 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <gpxe/list.h>
+#include <gpxe/xfer.h>
+#include <gpxe/open.h>
+#include <gpxe/process.h>
+#include <gpxe/posix_io.h>
+
+/** @file
+ *
+ * POSIX-like I/O
+ *
+ * These functions provide traditional blocking I/O semantics.  They
+ * are designed to be used by the PXE TFTP API.  Because they block,
+ * they may not be used by most other portions of the gPXE codebase.
+ */
+
+/** An open file */
+struct posix_file {
+	/** Reference count for this object */
+	struct refcnt refcnt;
+	/** List of open files */
+	struct list_head list;
+	/** File descriptor */
+	int fd;
+	/** Overall status
+	 *
+	 * Set to -EINPROGRESS while data transfer is in progress.
+	 */
+	int rc;
+	/** Data transfer interface */
+	struct xfer_interface xfer;
+	/** Current seek position */
+	size_t pos;
+	/** File size */
+	size_t filesize;
+	/** Received data queue */
+	struct list_head data;
+};
+
+/** List of open files */
+static LIST_HEAD ( posix_files );
+
+/**
+ * Free open file
+ *
+ * @v refcnt		Reference counter
+ */
+static void posix_file_free ( struct refcnt *refcnt ) {
+	struct posix_file *file =
+		container_of ( refcnt, struct posix_file, refcnt );
+	struct io_buffer *iobuf;
+	struct io_buffer *tmp;
+
+	list_for_each_entry_safe ( iobuf, tmp, &file->data, list ) {
+		list_del ( &iobuf->list );
+		free_iob ( iobuf );
+	}
+	free ( file );
+}
+
+/**
+ * Terminate file data transfer
+ *
+ * @v file		POSIX file
+ * @v rc		Reason for termination
+ */
+static void posix_file_finished ( struct posix_file *file, int rc ) {
+	xfer_nullify ( &file->xfer );
+	xfer_close ( &file->xfer, rc );
+	file->rc = rc;
+}
+
+/**
+ * Handle close() event
+ *
+ * @v xfer		POSIX file data transfer interface
+ * @v rc		Reason for close
+ */
+static void posix_file_xfer_close ( struct xfer_interface *xfer, int rc ) {
+	struct posix_file *file =
+		container_of ( xfer, struct posix_file, xfer );
+
+	posix_file_finished ( file, rc );
+}
+
+/**
+ * Handle deliver_iob() event
+ *
+ * @v xfer		POSIX file data transfer interface
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int
+posix_file_xfer_deliver_iob ( struct xfer_interface *xfer,
+			      struct io_buffer *iobuf,
+			      struct xfer_metadata *meta ) {
+	struct posix_file *file =
+		container_of ( xfer, struct posix_file, xfer );
+
+	/* Keep track of file position solely for the filesize */
+	if ( meta->whence != SEEK_CUR )
+		file->pos = 0;
+	file->pos += meta->offset;
+	if ( file->filesize < file->pos )
+		file->filesize = file->pos;
+
+	if ( iob_len ( iobuf ) ) {
+		list_add_tail ( &iobuf->list, &file->data );
+	} else {
+		free_iob ( iobuf );
+	}
+
+	return 0;
+}
+
+/** POSIX file data transfer interface operations */
+static struct xfer_interface_operations posix_file_xfer_operations = {
+	.close		= posix_file_xfer_close,
+	.vredirect	= xfer_vreopen,
+	.window		= unlimited_xfer_window,
+	.alloc_iob	= default_xfer_alloc_iob,
+	.deliver_iob	= posix_file_xfer_deliver_iob,
+	.deliver_raw	= xfer_deliver_as_iob,
+};
+
+/**
+ * Identify file by file descriptor
+ *
+ * @v fd		File descriptor
+ * @ret file		Corresponding file, or NULL
+ */
+static struct posix_file * posix_fd_to_file ( int fd ) {
+	struct posix_file *file;
+
+	list_for_each_entry ( file, &posix_files, list ) {
+		if ( file->fd == fd )
+			return file;
+	}
+	return NULL;
+}
+
+/**
+ * Find an available file descriptor
+ *
+ * @ret fd		File descriptor, or negative error number
+ */
+static int posix_find_free_fd ( void ) {
+	int fd;
+
+	for ( fd = POSIX_FD_MIN ; fd <= POSIX_FD_MAX ; fd++ ) {
+		if ( ! posix_fd_to_file ( fd ) )
+			return fd;
+	}
+	DBG ( "POSIX could not find free file descriptor\n" );
+	return -ENFILE;
+}
+
+/**
+ * Open file
+ *
+ * @v uri_string	URI string
+ * @ret fd		File descriptor, or negative error number
+ */
+int open ( const char *uri_string ) {
+	struct posix_file *file;
+	int fd;
+	int rc;
+
+	/* Find a free file descriptor to use */
+	fd = posix_find_free_fd();
+	if ( fd < 0 )
+		return fd;
+
+	/* Allocate and initialise structure */
+	file = zalloc ( sizeof ( *file ) );
+	if ( ! file )
+		return -ENOMEM;
+	file->refcnt.free = posix_file_free;
+	file->fd = fd;
+	file->rc = -EINPROGRESS;
+	xfer_init ( &file->xfer, &posix_file_xfer_operations,
+		    &file->refcnt );
+	INIT_LIST_HEAD ( &file->data );
+
+	/* Open URI on data transfer interface */
+	if ( ( rc = xfer_open_uri_string ( &file->xfer, uri_string ) ) != 0 )
+		goto err;
+
+	/* Wait for open to succeed or fail */
+	while ( list_empty ( &file->data ) ) {
+		step();
+		if ( file->rc == 0 )
+			break;
+		if ( file->rc != -EINPROGRESS ) {
+			rc = file->rc;
+			goto err;
+		}
+	}
+
+	/* Add to list of open files.  List takes reference ownership. */
+	list_add ( &file->list, &posix_files );
+	DBG ( "POSIX opened %s as file %d\n", uri_string, fd );
+	return fd;
+
+ err:
+	posix_file_finished ( file, rc );
+	ref_put ( &file->refcnt );
+	return rc;
+}
+
+/**
+ * Check file descriptors for readiness
+ *
+ * @v readfds		File descriptors to check
+ * @v wait		Wait until data is ready
+ * @ret nready		Number of ready file descriptors
+ */
+int select ( fd_set *readfds, int wait ) {
+	struct posix_file *file;
+	int fd;
+
+	do {
+		for ( fd = POSIX_FD_MIN ; fd <= POSIX_FD_MAX ; fd++ ) {
+			if ( ! FD_ISSET ( fd, readfds ) )
+				continue;
+			file = posix_fd_to_file ( fd );
+			if ( ! file )
+				return -EBADF;
+			if ( ( list_empty ( &file->data ) ) &&
+			     ( file->rc == -EINPROGRESS ) )
+				continue;
+			/* Data is available or status has changed */
+			FD_ZERO ( readfds );
+			FD_SET ( fd, readfds );
+			return 1;
+		}
+		step();
+	} while ( wait );
+
+	return 0;
+}
+
+/**
+ * Read data from file
+ *
+ * @v buffer		Data buffer
+ * @v offset		Starting offset within data buffer
+ * @v len		Maximum length to read
+ * @ret len		Actual length read, or negative error number
+ *
+ * This call is non-blocking; if no data is available to read then
+ * -EWOULDBLOCK will be returned.
+ */
+ssize_t read_user ( int fd, userptr_t buffer, off_t offset, size_t max_len ) {
+	struct posix_file *file;
+	struct io_buffer *iobuf;
+	size_t len;
+
+	/* Identify file */
+	file = posix_fd_to_file ( fd );
+	if ( ! file )
+		return -EBADF;
+
+	/* Try to fetch more data if none available */
+	if ( list_empty ( &file->data ) )
+		step();
+
+	/* Dequeue at most one received I/O buffer into user buffer */
+	list_for_each_entry ( iobuf, &file->data, list ) {
+		len = iob_len ( iobuf );
+		if ( len > max_len )
+			len = max_len;
+		copy_to_user ( buffer, offset, iobuf->data, len );
+		iob_pull ( iobuf, len );
+		if ( ! iob_len ( iobuf ) ) {
+			list_del ( &iobuf->list );
+			free_iob ( iobuf );
+		}
+		file->pos += len;
+		assert ( len != 0 );
+		return len;
+	}
+
+	/* If file has completed, return (after returning all data) */
+	if ( file->rc != -EINPROGRESS ) {
+		assert ( list_empty ( &file->data ) );
+		return file->rc;
+	}
+
+	/* No data ready and file still in progress; return -WOULDBLOCK */
+	return -EWOULDBLOCK;
+}
+
+/**
+ * Determine file size
+ *
+ * @v fd		File descriptor
+ * @ret size		File size, or negative error number
+ */
+ssize_t fsize ( int fd ) {
+	struct posix_file *file;
+
+	/* Identify file */
+	file = posix_fd_to_file ( fd );
+	if ( ! file )
+		return -EBADF;
+
+	return file->filesize;
+}
+
+/**
+ * Close file
+ *
+ * @v fd		File descriptor
+ * @ret rc		Return status code
+ */
+int close ( int fd ) {
+	struct posix_file *file;
+
+	/* Identify file */
+	file = posix_fd_to_file ( fd );
+	if ( ! file )
+		return -EBADF;
+
+	/* Terminate data transfer */
+	posix_file_finished ( file, 0 );
+
+	/* Remove from list of open files and drop reference */
+	list_del ( &file->list );
+	ref_put ( &file->refcnt );
+	return 0;
+}