src/core/downloader.c

   1 /*
   2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #include <stdlib.h>
  20 #include <stdarg.h>
  21 #include <errno.h>
  22 #include <gpxe/xfer.h>
  23 #include <gpxe/open.h>
  24 #include <gpxe/job.h>
  25 #include <gpxe/uaccess.h>
  26 #include <gpxe/umalloc.h>
  27 #include <gpxe/image.h>
  28 #include <gpxe/downloader.h>
  29
  30 /** @file
  31  *
  32  * Image downloader
  33  *
  34  */
  35
  36 /** A downloader */
  37 struct downloader {
  38         /** Reference count for this object */
  39         struct refcnt refcnt;
  40
  41         /** Job control interface */
  42         struct job_interface job;
  43         /** Data transfer interface */
  44         struct xfer_interface xfer;
  45
  46         /** Image to contain downloaded file */
  47         struct image *image;
  48         /** Current position within image buffer */
  49         size_t pos;
  50         /** Image registration routine */
  51         int ( * register_image ) ( struct image *image );
  52 };
  53
  54 /**
  55  * Free downloader object
  56  *
  57  * @v refcnt            Downloader reference counter
  58  */
  59 static void downloader_free ( struct refcnt *refcnt ) {
  60         struct downloader *downloader =
  61                 container_of ( refcnt, struct downloader, refcnt );
  62
  63         image_put ( downloader->image );
  64         free ( downloader );
  65 }
  66
  67 /**
  68  * Terminate download
  69  *
  70  * @v downloader        Downloader
  71  * @v rc                Reason for termination
  72  */
  73 static void downloader_finished ( struct downloader *downloader, int rc ) {
  74
  75         /* Block further incoming messages */
  76         job_nullify ( &downloader->job );
  77         xfer_nullify ( &downloader->xfer );
  78
  79         /* Free resources and close interfaces */
  80         xfer_close ( &downloader->xfer, rc );
  81         job_done ( &downloader->job, rc );
  82 }
  83
  84 /**
  85  * Ensure that download buffer is large enough for the specified size
  86  *
  87  * @v downloader        Downloader
  88  * @v len               Required minimum size
  89  * @ret rc              Return status code
  90  */
  91 static int downloader_ensure_size ( struct downloader *downloader,
  92                                     size_t len ) {
  93         userptr_t new_buffer;
  94
  95         /* If buffer is already large enough, do nothing */
  96         if ( len <= downloader->image->len )
  97                 return 0;
  98
  99         /* Extend buffer */
 100         new_buffer = urealloc ( downloader->image->data, len );
 101         if ( ! new_buffer ) {
 102                 DBGC ( downloader, "Downloader %p could not extend buffer to "
 103                        "%zd bytes\n", downloader, len );
 104                 return -ENOBUFS;
 105         }
 106         downloader->image->data = new_buffer;
 107         downloader->image->len = len;
 108
 109         return 0;
 110 }
 111
 112 /****************************************************************************
 113  *
 114  * Job control interface
 115  *
 116  */
 117
 118 /**
 119  * Handle kill() event received via job control interface
 120  *
 121  * @v job               Downloader job control interface
 122  */
 123 static void downloader_job_kill ( struct job_interface *job ) {
 124         struct downloader *downloader =
 125                 container_of ( job, struct downloader, job );
 126
 127         /* Terminate download */
 128         downloader_finished ( downloader, -ECANCELED );
 129 }
 130
 131 /** Downloader job control interface operations */
 132 static struct job_interface_operations downloader_job_operations = {
 133         .done           = ignore_job_done,
 134         .kill           = downloader_job_kill,
 135         .progress       = ignore_job_progress,
 136 };
 137
 138 /****************************************************************************
 139  *
 140  * Data transfer interface
 141  *
 142  */
 143
 144 /**
 145  * Handle seek() event received via data transfer interface
 146  *
 147  * @v xfer              Downloader data transfer interface
 148  * @v pos               New position
 149  * @ret rc              Return status code
 150  */
 151 static int downloader_xfer_seek ( struct xfer_interface *xfer, off_t offset,
 152                                   int whence ) {
 153         struct downloader *downloader =
 154                 container_of ( xfer, struct downloader, xfer );
 155         off_t new_pos;
 156         int rc;
 157
 158         /* Calculate new buffer position */
 159         switch ( whence ) {
 160         case SEEK_SET:
 161                 new_pos = offset;
 162                 break;
 163         case SEEK_CUR:
 164                 new_pos = ( downloader->pos + offset );
 165                 break;
 166         default:
 167                 assert ( 0 );
 168                 return -EINVAL;
 169         }
 170
 171         /* Ensure that we have enough buffer space for this buffer position */
 172         if ( ( rc = downloader_ensure_size ( downloader, new_pos ) ) != 0 )
 173                 return rc;
 174         downloader->pos = new_pos;
 175
 176         return 0;
 177 }
 178
 179 /**
 180  * Handle deliver_raw() event received via data transfer interface
 181  *
 182  * @v xfer              Downloader data transfer interface
 183  * @v data              Data buffer
 184  * @v len               Length of data buffer
 185  * @ret rc              Return status code
 186  */
 187 static int downloader_xfer_deliver_raw ( struct xfer_interface *xfer,
 188                                          const void *data, size_t len ) {
 189         struct downloader *downloader =
 190                 container_of ( xfer, struct downloader, xfer );
 191         size_t max;
 192         int rc;
 193
 194         /* Ensure that we have enough buffer space for this data */
 195         max = ( downloader->pos + len );
 196         if ( ( rc = downloader_ensure_size ( downloader, max ) ) != 0 )
 197                 return rc;
 198
 199         /* Copy data to buffer */
 200         copy_to_user ( downloader->image->data, downloader->pos, data, len );
 201
 202         /* Update current buffer position */
 203         downloader->pos += len;
 204
 205         return 0;
 206 }
 207
 208 /**
 209  * Handle close() event received via data transfer interface
 210  *
 211  * @v xfer              Downloader data transfer interface
 212  * @v rc                Reason for close
 213  */
 214 static void downloader_xfer_close ( struct xfer_interface *xfer, int rc ) {
 215         struct downloader *downloader =
 216                 container_of ( xfer, struct downloader, xfer );
 217
 218         /* Register image if download was successful */
 219         if ( rc == 0 )
 220                 rc = downloader->register_image ( downloader->image );
 221
 222         /* Terminate download */
 223         downloader_finished ( downloader, rc );
 224 }
 225
 226 /** Downloader data transfer interface operations */
 227 static struct xfer_interface_operations downloader_xfer_operations = {
 228         .close          = downloader_xfer_close,
 229         .vredirect      = xfer_vopen,
 230         .seek           = downloader_xfer_seek,
 231         .window         = unlimited_xfer_window,
 232         .deliver_iob    = xfer_deliver_as_raw,
 233         .deliver_raw    = downloader_xfer_deliver_raw,
 234 };
 235
 236 /****************************************************************************
 237  *
 238  * Instantiator
 239  *
 240  */
 241
 242 /**
 243  * Instantiate a downloader
 244  *
 245  * @v job               Job control interface
 246  * @v image             Image to fill with downloaded file
 247  * @v register_image    Image registration routine
 248  * @v type              Location type to pass to xfer_open()
 249  * @v ...               Remaining arguments to pass to xfer_open()
 250  * @ret rc              Return status code
 251  *
 252  * Instantiates a downloader object to download the specified URI into
 253  * the specified image object.  If the download is successful, the
 254  * image registration routine @c register_image() will be called.
 255  */
 256 int create_downloader ( struct job_interface *job, struct image *image,
 257                         int ( * register_image ) ( struct image *image ),
 258                         int type, ... ) {
 259         struct downloader *downloader;
 260         va_list args;
 261         int rc;
 262
 263         /* Allocate and initialise structure */
 264         downloader = zalloc ( sizeof ( *downloader ) );
 265         if ( ! downloader )
 266                 return -ENOMEM;
 267         downloader->refcnt.free = downloader_free;
 268         job_init ( &downloader->job, &downloader_job_operations,
 269                    &downloader->refcnt );
 270         xfer_init ( &downloader->xfer, &downloader_xfer_operations,
 271                     &downloader->refcnt );
 272         downloader->image = image_get ( image );
 273         downloader->register_image = register_image;
 274         va_start ( args, type );
 275
 276         /* Instantiate child objects and attach to our interfaces */
 277         if ( ( rc = xfer_vopen ( &downloader->xfer, type, args ) ) != 0 )
 278                 goto err;
 279
 280         /* Attach parent interface, mortalise self, and return */
 281         job_plug_plug ( &downloader->job, job );
 282         ref_put ( &downloader->refcnt );
 283         va_end ( args );
 284         return 0;
 285
 286  err:
 287         downloader_finished ( downloader, rc );
 288         ref_put ( &downloader->refcnt );
 289         va_end ( args );
 290         return rc;
 291 }