downloader.c

Go to the documentation of this file.

/*
 * 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 );
FILE_SECBOOT ( PERMITTED );

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <syslog.h>
#include <ipxe/iobuf.h>
#include <ipxe/xfer.h>
#include <ipxe/open.h>
#include <ipxe/job.h>
#include <ipxe/umalloc.h>
#include <ipxe/image.h>
#include <ipxe/xferbuf.h>
#include <ipxe/downloader.h>

/** @file
 *
 * Image downloader
 *
 */

/** A downloader */
struct downloader {
        /** Reference count for this object */
        struct refcnt refcnt;

        /** Job control interface */
        struct interface job;
        /** Data transfer interface */
        struct interface xfer;

        /** Image to contain downloaded file */
        struct image *image;
        /** Data transfer buffer */
        struct xfer_buffer buffer;
};

/**
 * Free downloader object
 *
 * @v refcnt            Downloader reference counter
 */
static void downloader_free ( struct refcnt *refcnt ) {
        struct downloader *downloader =
                container_of ( refcnt, struct downloader, refcnt );

        xferbuf_free ( &downloader->buffer );
        image_put ( downloader->image );
        free ( downloader );
}

/**
 * Terminate download
 *
 * @v downloader        Downloader
 * @v rc                Reason for termination
 */
static void downloader_finished ( struct downloader *downloader, int rc ) {
        struct xfer_buffer *buffer = &downloader->buffer;
        struct image *image = downloader->image;

        /* Log download status */
        if ( rc == 0 ) {
                syslog ( LOG_NOTICE, "Downloaded \"%s\"\n", image->name );
        } else {
                syslog ( LOG_ERR, "Download of \"%s\" failed: %s\n",
                         image->name, strerror ( rc ) );
        }

        /* Transfer ownership from data transfer buffer to image */
        image->data = buffer->data;
        image->len = buffer->len;
        xferbuf_detach ( buffer );

        /* Shut down interfaces */
        intf_shutdown ( &downloader->xfer, rc );
        intf_shutdown ( &downloader->job, rc );
}

/****************************************************************************
 *
 * Job control interface
 *
 */

/**
 * Report progress of download job
 *
 * @v downloader        Downloader
 * @v progress          Progress report to fill in
 * @ret ongoing_rc      Ongoing job status code (if known)
 */
static int downloader_progress ( struct downloader *downloader,
                                 struct job_progress *progress ) {
        int rc;

        /* Allow data transfer to provide an accurate description */
        if ( ( rc = job_progress ( &downloader->xfer, progress ) ) != 0 )
                return rc;

        /* This is not entirely accurate, since downloaded data may
         * arrive out of order (e.g. with multicast protocols), but
         * it's a reasonable first approximation.
         */
        if ( ! progress->total ) {
                progress->completed = downloader->buffer.pos;
                progress->total = downloader->buffer.len;
        }

        return 0;
}

/****************************************************************************
 *
 * Data transfer interface
 *
 */

/**
 * Handle received data
 *
 * @v downloader        Downloader
 * @v iobuf             Datagram I/O buffer
 * @v meta              Data transfer metadata
 * @ret rc              Return status code
 */
static int downloader_deliver ( struct downloader *downloader,
                                struct io_buffer *iobuf,
                                struct xfer_metadata *meta ) {
        int rc;

        /* Add data to buffer */
        if ( ( rc = xferbuf_deliver ( &downloader->buffer, iob_disown ( iobuf ),
                                      meta ) ) != 0 )
                goto err_deliver;

        return 0;

 err_deliver:
        downloader_finished ( downloader, rc );
        return rc;
}

/**
 * Get underlying data transfer buffer
 *
 * @v downloader        Downloader
 * @ret xferbuf         Data transfer buffer, or NULL on error
 */
static struct xfer_buffer *
downloader_buffer ( struct downloader *downloader ) {

        /* Provide direct access to underlying data transfer buffer */
        return &downloader->buffer;
}

/**
 * Redirect data transfer interface
 *
 * @v downloader        Downloader
 * @v type              New location type
 * @v args              Remaining arguments depend upon location type
 * @ret rc              Return status code
 */
static int downloader_vredirect ( struct downloader *downloader, int type,
                                  va_list args ) {
        va_list tmp;
        struct uri *uri;
        int rc;

        /* Intercept redirects to a LOCATION_URI and update the image URI */
        if ( type == LOCATION_URI ) {

                /* Extract URI argument */
                va_copy ( tmp, args );
                uri = va_arg ( tmp, struct uri * );
                va_end ( tmp );

                /* Set image URI */
                if ( ( rc = image_set_uri ( downloader->image, uri ) ) != 0 )
                        goto err;
        }

        /* Redirect to new location */
        if ( ( rc = xfer_vreopen ( &downloader->xfer, type, args ) ) != 0 )
                goto err;

        return 0;

 err:
        downloader_finished ( downloader, rc );
        return rc;
}

/** Downloader data transfer interface operations */
static struct interface_operation downloader_xfer_operations[] = {
        INTF_OP ( xfer_deliver, struct downloader *, downloader_deliver ),
        INTF_OP ( xfer_buffer, struct downloader *, downloader_buffer ),
        INTF_OP ( xfer_vredirect, struct downloader *, downloader_vredirect ),
        INTF_OP ( intf_close, struct downloader *, downloader_finished ),
};

/** Downloader data transfer interface descriptor */
static struct interface_descriptor downloader_xfer_desc =
        INTF_DESC ( struct downloader, xfer, downloader_xfer_operations );

/****************************************************************************
 *
 * Job control interface
 *
 */

/** Downloader job control interface operations */
static struct interface_operation downloader_job_op[] = {
        INTF_OP ( job_progress, struct downloader *, downloader_progress ),
        INTF_OP ( intf_close, struct downloader *, downloader_finished ),
};

/** Downloader job control interface descriptor */
static struct interface_descriptor downloader_job_desc =
        INTF_DESC ( struct downloader, job, downloader_job_op );

/****************************************************************************
 *
 * Instantiator
 *
 */

/**
 * Instantiate a downloader
 *
 * @v job               Job control interface
 * @v image             Image to fill with downloaded file
 * @ret rc              Return status code
 *
 * Instantiates a downloader object to download the content of the
 * specified image from its URI.
 */
int create_downloader ( struct interface *job, struct image *image ) {
        struct downloader *downloader;
        int rc;

        /* Allocate and initialise structure */
        downloader = zalloc ( sizeof ( *downloader ) );
        if ( ! downloader )
                return -ENOMEM;
        ref_init ( &downloader->refcnt, downloader_free );
        intf_init ( &downloader->job, &downloader_job_desc,
                    &downloader->refcnt );
        intf_init ( &downloader->xfer, &downloader_xfer_desc,
                    &downloader->refcnt );
        downloader->image = image_get ( image );
        xferbuf_umalloc_init ( &downloader->buffer );

        /* Instantiate child objects and attach to our interfaces */
        if ( ( rc = xfer_open_uri ( &downloader->xfer, image->uri ) ) != 0 )
                goto err;

        /* Attach parent interface, mortalise self, and return */
        intf_plug_plug ( &downloader->job, job );
        ref_put ( &downloader->refcnt );
        return 0;

 err:
        downloader_finished ( downloader, rc );
        ref_put ( &downloader->refcnt );
        return rc;
}