efi_download.c

Go to the documentation of this file.

/*
 * Copyright (C) 2010 VMware, Inc.  All Rights Reserved.
 *
 * 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 St, Fifth Floor, Boston, MA 02110-1301 USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );
FILE_SECBOOT ( PERMITTED );

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ipxe/open.h>
#include <ipxe/process.h>
#include <ipxe/iobuf.h>
#include <ipxe/xfer.h>
#include <ipxe/efi/efi.h>
#include <ipxe/efi/efi_snp.h>
#include <ipxe/efi/efi_download.h>

/** iPXE download protocol GUID */
static EFI_GUID ipxe_download_protocol_guid
        = IPXE_DOWNLOAD_PROTOCOL_GUID;

/** A single in-progress file */
struct efi_download_file {
        /** Data transfer interface that provides downloaded data */
        struct interface xfer;

        /** Current file position */
        size_t pos;

        /** Data callback */
        IPXE_DOWNLOAD_DATA_CALLBACK data_callback;

        /** Finish callback */
        IPXE_DOWNLOAD_FINISH_CALLBACK finish_callback;

        /** Callback context */
        void *context;
};

/* xfer interface */

/**
 * Transfer finished or was aborted
 *
 * @v file              Data transfer file
 * @v rc                Reason for close
 */
static void efi_download_close ( struct efi_download_file *file, int rc ) {

        file->finish_callback ( file->context, EFIRC ( rc ) );

        intf_shutdown ( &file->xfer, rc );

        efi_snp_release();
}

/**
 * Process received data
 *
 * @v file              Data transfer file
 * @v iobuf             I/O buffer
 * @v meta              Data transfer metadata
 * @ret rc              Return status code
 */
static int efi_download_deliver_iob ( struct efi_download_file *file,
                                      struct io_buffer *iobuf,
                                      struct xfer_metadata *meta ) {
        EFI_STATUS efirc;
        size_t len = iob_len ( iobuf );
        int rc;

        /* Calculate new buffer position */
        if ( meta->flags & XFER_FL_ABS_OFFSET )
                file->pos = 0;
        file->pos += meta->offset;

        /* Call out to the data handler */
        if ( ( efirc = file->data_callback ( file->context, iobuf->data,
                                             len, file->pos ) ) != 0 ) {
                rc = -EEFI ( efirc );
                goto err_callback;
        }

        /* Update current buffer position */
        file->pos += len;

        /* Success */
        rc = 0;

 err_callback:
        free_iob ( iobuf );
        return rc;
}

/** Data transfer interface operations */
static struct interface_operation efi_xfer_operations[] = {
        INTF_OP ( xfer_deliver, struct efi_download_file *, efi_download_deliver_iob ),
        INTF_OP ( intf_close, struct efi_download_file *, efi_download_close ),
};

/** EFI download data transfer interface descriptor */
static struct interface_descriptor efi_download_file_xfer_desc =
        INTF_DESC ( struct efi_download_file, xfer, efi_xfer_operations );

/**
 * Start downloading a file, and register callback functions to handle the
 * download.
 *
 * @v This              iPXE Download Protocol instance
 * @v Url               URL to download from
 * @v DataCallback      Callback that will be invoked when data arrives
 * @v FinishCallback    Callback that will be invoked when the download ends
 * @v Context           Context passed to the Data and Finish callbacks
 * @v File              Token that can be used to abort the download
 * @ret Status          EFI status code
 */
static EFI_STATUS EFIAPI
efi_download_start ( IPXE_DOWNLOAD_PROTOCOL *This __unused,
                     CHAR8 *Url,
                     IPXE_DOWNLOAD_DATA_CALLBACK DataCallback,
                     IPXE_DOWNLOAD_FINISH_CALLBACK FinishCallback,
                     VOID *Context,
                     IPXE_DOWNLOAD_FILE *File ) {
        struct efi_download_file *file;
        int rc;

        efi_snp_claim();

        file = malloc ( sizeof ( struct efi_download_file ) );
        if ( file == NULL ) {
                efi_snp_release();
                return EFI_OUT_OF_RESOURCES;
        }

        intf_init ( &file->xfer, &efi_download_file_xfer_desc, NULL );
        rc = xfer_open ( &file->xfer, LOCATION_URI_STRING, Url );
        if ( rc ) {
                free ( file );
                efi_snp_release();
                return EFIRC ( rc );
        }

        file->pos = 0;
        file->data_callback = DataCallback;
        file->finish_callback = FinishCallback;
        file->context = Context;
        *File = file;
        return EFI_SUCCESS;
}

/**
 * Forcibly abort downloading a file that is currently in progress.
 *
 * It is not safe to call this function after the Finish callback has executed.
 *
 * @v This              iPXE Download Protocol instance
 * @v File              Token obtained from Start
 * @v Status            Reason for aborting the download
 * @ret Status          EFI status code
 */
static EFI_STATUS EFIAPI
efi_download_abort ( IPXE_DOWNLOAD_PROTOCOL *This __unused,
                     IPXE_DOWNLOAD_FILE File,
                     EFI_STATUS Status ) {
        struct efi_download_file *file = File;

        efi_download_close ( file, -EEFI ( Status ) );
        return EFI_SUCCESS;
}

/**
 * Poll for more data from iPXE. This function will invoke the registered
 * callbacks if data is available or if downloads complete.
 *
 * @v This              iPXE Download Protocol instance
 * @ret Status          EFI status code
 */
static EFI_STATUS EFIAPI
efi_download_poll ( IPXE_DOWNLOAD_PROTOCOL *This __unused ) {
        step();
        return EFI_SUCCESS;
}

/** Publicly exposed iPXE download protocol */
static IPXE_DOWNLOAD_PROTOCOL ipxe_download_protocol_interface = {
        .Start = efi_download_start,
        .Abort = efi_download_abort,
        .Poll = efi_download_poll
};

/**
 * Install iPXE download protocol
 *
 * @v handle            EFI handle
 * @ret rc              Return status code
 */
int efi_download_install ( EFI_HANDLE handle ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        EFI_STATUS efirc;
        int rc;

        efirc = bs->InstallMultipleProtocolInterfaces (
                        &handle,
                        &ipxe_download_protocol_guid,
                        &ipxe_download_protocol_interface,
                        NULL );
        if ( efirc ) {
                rc = -EEFI ( efirc );
                DBG ( "Could not install download protocol: %s\n",
                      strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Uninstall iPXE download protocol
 *
 * @v handle            EFI handle
 */
void efi_download_uninstall ( EFI_HANDLE handle ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;

        bs->UninstallMultipleProtocolInterfaces (
                        handle,
                        &ipxe_download_protocol_guid,
                        &ipxe_download_protocol_interface, NULL );
}