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author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/ipxe/src/core/posix_io.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/ipxe/src/core/posix_io.c')
-rw-r--r-- | qemu/roms/ipxe/src/core/posix_io.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/core/posix_io.c b/qemu/roms/ipxe/src/core/posix_io.c new file mode 100644 index 000000000..8460d0f51 --- /dev/null +++ b/qemu/roms/ipxe/src/core/posix_io.c @@ -0,0 +1,339 @@ +/* + * 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. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <ipxe/list.h> +#include <ipxe/iobuf.h> +#include <ipxe/xfer.h> +#include <ipxe/open.h> +#include <ipxe/process.h> +#include <ipxe/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 iPXE 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 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 ) { + intf_shutdown ( &file->xfer, rc ); + file->rc = rc; +} + +/** + * Handle deliver_iob() event + * + * @v file POSIX file + * @v iobuf I/O buffer + * @v meta Data transfer metadata + * @ret rc Return status code + */ +static int posix_file_xfer_deliver ( struct posix_file *file, + struct io_buffer *iobuf, + struct xfer_metadata *meta ) { + + /* Keep track of file position solely for the filesize */ + if ( meta->flags & XFER_FL_ABS_OFFSET ) + 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 interface_operation posix_file_xfer_operations[] = { + INTF_OP ( xfer_deliver, struct posix_file *, posix_file_xfer_deliver ), + INTF_OP ( intf_close, struct posix_file *, posix_file_finished ), +}; + +/** POSIX file data transfer interface descriptor */ +static struct interface_descriptor posix_file_xfer_desc = + INTF_DESC ( struct posix_file, xfer, posix_file_xfer_operations ); + +/** + * 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; + ref_init ( &file->refcnt, posix_file_free ); + file->fd = fd; + file->rc = -EINPROGRESS; + intf_init ( &file->xfer, &posix_file_xfer_desc, &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; +} |