arch/um/drivers/net_kern.c

   1 /*
   2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
   4  * James Leu (jleu@mindspring.net).
   5  * Copyright (C) 2001 by various other people who didn't put their name here.
   6  * Licensed under the GPL.
   7  */
   8
   9 #include <linux/bootmem.h>
  10 #include <linux/etherdevice.h>
  11 #include <linux/ethtool.h>
  12 #include <linux/inetdevice.h>
  13 #include <linux/init.h>
  14 #include <linux/list.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21 #include "init.h"
  22 #include "irq_kern.h"
  23 #include "irq_user.h"
  24 #include "mconsole_kern.h"
  25 #include "net_kern.h"
  26 #include "net_user.h"
  27
  28 static inline void set_ether_mac(struct net_device *dev, unsigned char *addr)
  29 {
  30         memcpy(dev->dev_addr, addr, ETH_ALEN);
  31 }
  32
  33 #define DRIVER_NAME "uml-netdev"
  34
  35 static DEFINE_SPINLOCK(opened_lock);
  36 static LIST_HEAD(opened);
  37
  38 /*
  39  * The drop_skb is used when we can't allocate an skb.  The
  40  * packet is read into drop_skb in order to get the data off the
  41  * connection to the host.
  42  * It is reallocated whenever a maximum packet size is seen which is
  43  * larger than any seen before.  update_drop_skb is called from
  44  * eth_configure when a new interface is added.
  45  */
  46 static DEFINE_SPINLOCK(drop_lock);
  47 static struct sk_buff *drop_skb;
  48 static int drop_max;
  49
  50 static int update_drop_skb(int max)
  51 {
  52         struct sk_buff *new;
  53         unsigned long flags;
  54         int err = 0;
  55
  56         spin_lock_irqsave(&drop_lock, flags);
  57
  58         if (max <= drop_max)
  59                 goto out;
  60
  61         err = -ENOMEM;
  62         new = dev_alloc_skb(max);
  63         if (new == NULL)
  64                 goto out;
  65
  66         skb_put(new, max);
  67
  68         kfree_skb(drop_skb);
  69         drop_skb = new;
  70         drop_max = max;
  71         err = 0;
  72 out:
  73         spin_unlock_irqrestore(&drop_lock, flags);
  74
  75         return err;
  76 }
  77
  78 static int uml_net_rx(struct net_device *dev)
  79 {
  80         struct uml_net_private *lp = netdev_priv(dev);
  81         int pkt_len;
  82         struct sk_buff *skb;
  83
  84         /* If we can't allocate memory, try again next round. */
  85         skb = dev_alloc_skb(lp->max_packet);
  86         if (skb == NULL) {
  87                 drop_skb->dev = dev;
  88                 /* Read a packet into drop_skb and don't do anything with it. */
  89                 (*lp->read)(lp->fd, drop_skb, lp);
  90                 dev->stats.rx_dropped++;
  91                 return 0;
  92         }
  93
  94         skb->dev = dev;
  95         skb_put(skb, lp->max_packet);
  96         skb_reset_mac_header(skb);
  97         pkt_len = (*lp->read)(lp->fd, skb, lp);
  98
  99         if (pkt_len > 0) {
 100                 skb_trim(skb, pkt_len);
 101                 skb->protocol = (*lp->protocol)(skb);
 102
 103                 dev->stats.rx_bytes += skb->len;
 104                 dev->stats.rx_packets++;
 105                 netif_rx(skb);
 106                 return pkt_len;
 107         }
 108
 109         kfree_skb(skb);
 110         return pkt_len;
 111 }
 112
 113 static void uml_dev_close(struct work_struct *work)
 114 {
 115         struct uml_net_private *lp =
 116                 container_of(work, struct uml_net_private, work);
 117         dev_close(lp->dev);
 118 }
 119
 120 static irqreturn_t uml_net_interrupt(int irq, void *dev_id)
 121 {
 122         struct net_device *dev = dev_id;
 123         struct uml_net_private *lp = netdev_priv(dev);
 124         int err;
 125
 126         if (!netif_running(dev))
 127                 return IRQ_NONE;
 128
 129         spin_lock(&lp->lock);
 130         while ((err = uml_net_rx(dev)) > 0) ;
 131         if (err < 0) {
 132                 printk(KERN_ERR
 133                        "Device '%s' read returned %d, shutting it down\n",
 134                        dev->name, err);
 135                 /* dev_close can't be called in interrupt context, and takes
 136                  * again lp->lock.
 137                  * And dev_close() can be safely called multiple times on the
 138                  * same device, since it tests for (dev->flags & IFF_UP). So
 139                  * there's no harm in delaying the device shutdown.
 140                  * Furthermore, the workqueue will not re-enqueue an already
 141                  * enqueued work item. */
 142                 schedule_work(&lp->work);
 143                 goto out;
 144         }
 145         reactivate_fd(lp->fd, UM_ETH_IRQ);
 146
 147 out:
 148         spin_unlock(&lp->lock);
 149         return IRQ_HANDLED;
 150 }
 151
 152 static int uml_net_open(struct net_device *dev)
 153 {
 154         struct uml_net_private *lp = netdev_priv(dev);
 155         int err;
 156
 157         if (lp->fd >= 0) {
 158                 err = -ENXIO;
 159                 goto out;
 160         }
 161
 162         lp->fd = (*lp->open)(&lp->user);
 163         if (lp->fd < 0) {
 164                 err = lp->fd;
 165                 goto out;
 166         }
 167
 168         err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
 169                              IRQF_DISABLED | IRQF_SHARED, dev->name, dev);
 170         if (err != 0) {
 171                 printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
 172                 err = -ENETUNREACH;
 173                 goto out_close;
 174         }
 175
 176         lp->tl.data = (unsigned long) &lp->user;
 177         netif_start_queue(dev);
 178
 179         /* clear buffer - it can happen that the host side of the interface
 180          * is full when we get here.  In this case, new data is never queued,
 181          * SIGIOs never arrive, and the net never works.
 182          */
 183         while ((err = uml_net_rx(dev)) > 0) ;
 184
 185         spin_lock(&opened_lock);
 186         list_add(&lp->list, &opened);
 187         spin_unlock(&opened_lock);
 188
 189         return 0;
 190 out_close:
 191         if (lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
 192         lp->fd = -1;
 193 out:
 194         return err;
 195 }
 196
 197 static int uml_net_close(struct net_device *dev)
 198 {
 199         struct uml_net_private *lp = netdev_priv(dev);
 200
 201         netif_stop_queue(dev);
 202
 203         free_irq(dev->irq, dev);
 204         if (lp->close != NULL)
 205                 (*lp->close)(lp->fd, &lp->user);
 206         lp->fd = -1;
 207
 208         spin_lock(&opened_lock);
 209         list_del(&lp->list);
 210         spin_unlock(&opened_lock);
 211
 212         return 0;
 213 }
 214
 215 static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 216 {
 217         struct uml_net_private *lp = netdev_priv(dev);
 218         unsigned long flags;
 219         int len;
 220
 221         netif_stop_queue(dev);
 222
 223         spin_lock_irqsave(&lp->lock, flags);
 224
 225         len = (*lp->write)(lp->fd, skb, lp);
 226
 227         if (len == skb->len) {
 228                 dev->stats.tx_packets++;
 229                 dev->stats.tx_bytes += skb->len;
 230                 dev->trans_start = jiffies;
 231                 netif_start_queue(dev);
 232
 233                 /* this is normally done in the interrupt when tx finishes */
 234                 netif_wake_queue(dev);
 235         }
 236         else if (len == 0) {
 237                 netif_start_queue(dev);
 238                 dev->stats.tx_dropped++;
 239         }
 240         else {
 241                 netif_start_queue(dev);
 242                 printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
 243         }
 244
 245         spin_unlock_irqrestore(&lp->lock, flags);
 246
 247         dev_kfree_skb(skb);
 248
 249         return NETDEV_TX_OK;
 250 }
 251
 252 static void uml_net_set_multicast_list(struct net_device *dev)
 253 {
 254         return;
 255 }
 256
 257 static void uml_net_tx_timeout(struct net_device *dev)
 258 {
 259         dev->trans_start = jiffies;
 260         netif_wake_queue(dev);
 261 }
 262
 263 static int uml_net_set_mac(struct net_device *dev, void *addr)
 264 {
 265         struct uml_net_private *lp = netdev_priv(dev);
 266         struct sockaddr *hwaddr = addr;
 267
 268         spin_lock_irq(&lp->lock);
 269         set_ether_mac(dev, hwaddr->sa_data);
 270         spin_unlock_irq(&lp->lock);
 271
 272         return 0;
 273 }
 274
 275 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
 276 {
 277         dev->mtu = new_mtu;
 278
 279         return 0;
 280 }
 281
 282 static void uml_net_get_drvinfo(struct net_device *dev,
 283                                 struct ethtool_drvinfo *info)
 284 {
 285         strcpy(info->driver, DRIVER_NAME);
 286         strcpy(info->version, "42");
 287 }
 288
 289 static const struct ethtool_ops uml_net_ethtool_ops = {
 290         .get_drvinfo    = uml_net_get_drvinfo,
 291         .get_link       = ethtool_op_get_link,
 292 };
 293
 294 static void uml_net_user_timer_expire(unsigned long _conn)
 295 {
 296 #ifdef undef
 297         struct connection *conn = (struct connection *)_conn;
 298
 299         dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
 300         do_connect(conn);
 301 #endif
 302 }
 303
 304 static void setup_etheraddr(char *str, unsigned char *addr, char *name)
 305 {
 306         char *end;
 307         int i;
 308
 309         if (str == NULL)
 310                 goto random;
 311
 312         for (i = 0; i < 6; i++) {
 313                 addr[i] = simple_strtoul(str, &end, 16);
 314                 if ((end == str) ||
 315                    ((*end != ':') && (*end != ',') && (*end != '\0'))) {
 316                         printk(KERN_ERR
 317                                "setup_etheraddr: failed to parse '%s' "
 318                                "as an ethernet address\n", str);
 319                         goto random;
 320                 }
 321                 str = end + 1;
 322         }
 323         if (is_multicast_ether_addr(addr)) {
 324                 printk(KERN_ERR
 325                        "Attempt to assign a multicast ethernet address to a "
 326                        "device disallowed\n");
 327                 goto random;
 328         }
 329         if (!is_valid_ether_addr(addr)) {
 330                 printk(KERN_ERR
 331                        "Attempt to assign an invalid ethernet address to a "
 332                        "device disallowed\n");
 333                 goto random;
 334         }
 335         if (!is_local_ether_addr(addr)) {
 336                 printk(KERN_WARNING
 337                        "Warning: Assigning a globally valid ethernet "
 338                        "address to a device\n");
 339                 printk(KERN_WARNING "You should set the 2nd rightmost bit in "
 340                        "the first byte of the MAC,\n");
 341                 printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
 342                        addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
 343                        addr[5]);
 344         }
 345         return;
 346
 347 random:
 348         printk(KERN_INFO
 349                "Choosing a random ethernet address for device %s\n", name);
 350         random_ether_addr(addr);
 351 }
 352
 353 static DEFINE_SPINLOCK(devices_lock);
 354 static LIST_HEAD(devices);
 355
 356 static struct platform_driver uml_net_driver = {
 357         .driver = {
 358                 .name  = DRIVER_NAME,
 359         },
 360 };
 361
 362 static void net_device_release(struct device *dev)
 363 {
 364         struct uml_net *device = dev_get_drvdata(dev);
 365         struct net_device *netdev = device->dev;
 366         struct uml_net_private *lp = netdev_priv(netdev);
 367
 368         if (lp->remove != NULL)
 369                 (*lp->remove)(&lp->user);
 370         list_del(&device->list);
 371         kfree(device);
 372         free_netdev(netdev);
 373 }
 374
 375 static const struct net_device_ops uml_netdev_ops = {
 376         .ndo_open               = uml_net_open,
 377         .ndo_stop               = uml_net_close,
 378         .ndo_start_xmit         = uml_net_start_xmit,
 379         .ndo_set_multicast_list = uml_net_set_multicast_list,
 380         .ndo_tx_timeout         = uml_net_tx_timeout,
 381         .ndo_set_mac_address    = uml_net_set_mac,
 382         .ndo_change_mtu         = uml_net_change_mtu,
 383         .ndo_set_mac_address    = eth_mac_addr,
 384         .ndo_validate_addr      = eth_validate_addr,
 385 };
 386
 387 /*
 388  * Ensures that platform_driver_register is called only once by
 389  * eth_configure.  Will be set in an initcall.
 390  */
 391 static int driver_registered;
 392
 393 static void eth_configure(int n, void *init, char *mac,
 394                           struct transport *transport)
 395 {
 396         struct uml_net *device;
 397         struct net_device *dev;
 398         struct uml_net_private *lp;
 399         int err, size;
 400
 401         size = transport->private_size + sizeof(struct uml_net_private);
 402
 403         device = kzalloc(sizeof(*device), GFP_KERNEL);
 404         if (device == NULL) {
 405                 printk(KERN_ERR "eth_configure failed to allocate struct "
 406                        "uml_net\n");
 407                 return;
 408         }
 409
 410         dev = alloc_etherdev(size);
 411         if (dev == NULL) {
 412                 printk(KERN_ERR "eth_configure: failed to allocate struct "
 413                        "net_device for eth%d\n", n);
 414                 goto out_free_device;
 415         }
 416
 417         INIT_LIST_HEAD(&device->list);
 418         device->index = n;
 419
 420         /* If this name ends up conflicting with an existing registered
 421          * netdevice, that is OK, register_netdev{,ice}() will notice this
 422          * and fail.
 423          */
 424         snprintf(dev->name, sizeof(dev->name), "eth%d", n);
 425
 426         setup_etheraddr(mac, device->mac, dev->name);
 427
 428         printk(KERN_INFO "Netdevice %d (%pM) : ", n, device->mac);
 429
 430         lp = netdev_priv(dev);
 431         /* This points to the transport private data. It's still clear, but we
 432          * must memset it to 0 *now*. Let's help the drivers. */
 433         memset(lp, 0, size);
 434         INIT_WORK(&lp->work, uml_dev_close);
 435
 436         /* sysfs register */
 437         if (!driver_registered) {
 438                 platform_driver_register(&uml_net_driver);
 439                 driver_registered = 1;
 440         }
 441         device->pdev.id = n;
 442         device->pdev.name = DRIVER_NAME;
 443         device->pdev.dev.release = net_device_release;
 444         dev_set_drvdata(&device->pdev.dev, device);
 445         if (platform_device_register(&device->pdev))
 446                 goto out_free_netdev;
 447         SET_NETDEV_DEV(dev,&device->pdev.dev);
 448
 449         device->dev = dev;
 450
 451         /*
 452          * These just fill in a data structure, so there's no failure
 453          * to be worried about.
 454          */
 455         (*transport->kern->init)(dev, init);
 456
 457         *lp = ((struct uml_net_private)
 458                 { .list                 = LIST_HEAD_INIT(lp->list),
 459                   .dev                  = dev,
 460                   .fd                   = -1,
 461                   .mac                  = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
 462                   .max_packet           = transport->user->max_packet,
 463                   .protocol             = transport->kern->protocol,
 464                   .open                 = transport->user->open,
 465                   .close                = transport->user->close,
 466                   .remove               = transport->user->remove,
 467                   .read                 = transport->kern->read,
 468                   .write                = transport->kern->write,
 469                   .add_address          = transport->user->add_address,
 470                   .delete_address       = transport->user->delete_address });
 471
 472         init_timer(&lp->tl);
 473         spin_lock_init(&lp->lock);
 474         lp->tl.function = uml_net_user_timer_expire;
 475         memcpy(lp->mac, device->mac, sizeof(lp->mac));
 476
 477         if ((transport->user->init != NULL) &&
 478             ((*transport->user->init)(&lp->user, dev) != 0))
 479                 goto out_unregister;
 480
 481         set_ether_mac(dev, device->mac);
 482         dev->mtu = transport->user->mtu;
 483         dev->netdev_ops = &uml_netdev_ops;
 484         dev->ethtool_ops = &uml_net_ethtool_ops;
 485         dev->watchdog_timeo = (HZ >> 1);
 486         dev->irq = UM_ETH_IRQ;
 487
 488         err = update_drop_skb(lp->max_packet);
 489         if (err)
 490                 goto out_undo_user_init;
 491
 492         rtnl_lock();
 493         err = register_netdevice(dev);
 494         rtnl_unlock();
 495         if (err)
 496                 goto out_undo_user_init;
 497
 498         spin_lock(&devices_lock);
 499         list_add(&device->list, &devices);
 500         spin_unlock(&devices_lock);
 501
 502         return;
 503
 504 out_undo_user_init:
 505         if (transport->user->remove != NULL)
 506                 (*transport->user->remove)(&lp->user);
 507 out_unregister:
 508         platform_device_unregister(&device->pdev);
 509         return; /* platform_device_unregister frees dev and device */
 510 out_free_netdev:
 511         free_netdev(dev);
 512 out_free_device:
 513         kfree(device);
 514 }
 515
 516 static struct uml_net *find_device(int n)
 517 {
 518         struct uml_net *device;
 519         struct list_head *ele;
 520
 521         spin_lock(&devices_lock);
 522         list_for_each(ele, &devices) {
 523                 device = list_entry(ele, struct uml_net, list);
 524                 if (device->index == n)
 525                         goto out;
 526         }
 527         device = NULL;
 528  out:
 529         spin_unlock(&devices_lock);
 530         return device;
 531 }
 532
 533 static int eth_parse(char *str, int *index_out, char **str_out,
 534                      char **error_out)
 535 {
 536         char *end;
 537         int n, err = -EINVAL;
 538
 539         n = simple_strtoul(str, &end, 0);
 540         if (end == str) {
 541                 *error_out = "Bad device number";
 542                 return err;
 543         }
 544
 545         str = end;
 546         if (*str != '=') {
 547                 *error_out = "Expected '=' after device number";
 548                 return err;
 549         }
 550
 551         str++;
 552         if (find_device(n)) {
 553                 *error_out = "Device already configured";
 554                 return err;
 555         }
 556
 557         *index_out = n;
 558         *str_out = str;
 559         return 0;
 560 }
 561
 562 struct eth_init {
 563         struct list_head list;
 564         char *init;
 565         int index;
 566 };
 567
 568 static DEFINE_SPINLOCK(transports_lock);
 569 static LIST_HEAD(transports);
 570
 571 /* Filled in during early boot */
 572 static LIST_HEAD(eth_cmd_line);
 573
 574 static int check_transport(struct transport *transport, char *eth, int n,
 575                            void **init_out, char **mac_out)
 576 {
 577         int len;
 578
 579         len = strlen(transport->name);
 580         if (strncmp(eth, transport->name, len))
 581                 return 0;
 582
 583         eth += len;
 584         if (*eth == ',')
 585                 eth++;
 586         else if (*eth != '\0')
 587                 return 0;
 588
 589         *init_out = kmalloc(transport->setup_size, GFP_KERNEL);
 590         if (*init_out == NULL)
 591                 return 1;
 592
 593         if (!transport->setup(eth, mac_out, *init_out)) {
 594                 kfree(*init_out);
 595                 *init_out = NULL;
 596         }
 597         return 1;
 598 }
 599
 600 void register_transport(struct transport *new)
 601 {
 602         struct list_head *ele, *next;
 603         struct eth_init *eth;
 604         void *init;
 605         char *mac = NULL;
 606         int match;
 607
 608         spin_lock(&transports_lock);
 609         BUG_ON(!list_empty(&new->list));
 610         list_add(&new->list, &transports);
 611         spin_unlock(&transports_lock);
 612
 613         list_for_each_safe(ele, next, &eth_cmd_line) {
 614                 eth = list_entry(ele, struct eth_init, list);
 615                 match = check_transport(new, eth->init, eth->index, &init,
 616                                         &mac);
 617                 if (!match)
 618                         continue;
 619                 else if (init != NULL) {
 620                         eth_configure(eth->index, init, mac, new);
 621                         kfree(init);
 622                 }
 623                 list_del(&eth->list);
 624         }
 625 }
 626
 627 static int eth_setup_common(char *str, int index)
 628 {
 629         struct list_head *ele;
 630         struct transport *transport;
 631         void *init;
 632         char *mac = NULL;
 633         int found = 0;
 634
 635         spin_lock(&transports_lock);
 636         list_for_each(ele, &transports) {
 637                 transport = list_entry(ele, struct transport, list);
 638                 if (!check_transport(transport, str, index, &init, &mac))
 639                         continue;
 640                 if (init != NULL) {
 641                         eth_configure(index, init, mac, transport);
 642                         kfree(init);
 643                 }
 644                 found = 1;
 645                 break;
 646         }
 647
 648         spin_unlock(&transports_lock);
 649         return found;
 650 }
 651
 652 static int __init eth_setup(char *str)
 653 {
 654         struct eth_init *new;
 655         char *error;
 656         int n, err;
 657
 658         err = eth_parse(str, &n, &str, &error);
 659         if (err) {
 660                 printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
 661                        str, error);
 662                 return 1;
 663         }
 664
 665         new = alloc_bootmem(sizeof(*new));
 666         if (new == NULL) {
 667                 printk(KERN_ERR "eth_init : alloc_bootmem failed\n");
 668                 return 1;
 669         }
 670
 671         INIT_LIST_HEAD(&new->list);
 672         new->index = n;
 673         new->init = str;
 674
 675         list_add_tail(&new->list, &eth_cmd_line);
 676         return 1;
 677 }
 678
 679 __setup("eth", eth_setup);
 680 __uml_help(eth_setup,
 681 "eth[0-9]+=<transport>,<options>\n"
 682 "    Configure a network device.\n\n"
 683 );
 684
 685 static int net_config(char *str, char **error_out)
 686 {
 687         int n, err;
 688
 689         err = eth_parse(str, &n, &str, error_out);
 690         if (err)
 691                 return err;
 692
 693         /* This string is broken up and the pieces used by the underlying
 694          * driver.  So, it is freed only if eth_setup_common fails.
 695          */
 696         str = kstrdup(str, GFP_KERNEL);
 697         if (str == NULL) {
 698                 *error_out = "net_config failed to strdup string";
 699                 return -ENOMEM;
 700         }
 701         err = !eth_setup_common(str, n);
 702         if (err)
 703                 kfree(str);
 704         return err;
 705 }
 706
 707 static int net_id(char **str, int *start_out, int *end_out)
 708 {
 709         char *end;
 710         int n;
 711
 712         n = simple_strtoul(*str, &end, 0);
 713         if ((*end != '\0') || (end == *str))
 714                 return -1;
 715
 716         *start_out = n;
 717         *end_out = n;
 718         *str = end;
 719         return n;
 720 }
 721
 722 static int net_remove(int n, char **error_out)
 723 {
 724         struct uml_net *device;
 725         struct net_device *dev;
 726         struct uml_net_private *lp;
 727
 728         device = find_device(n);
 729         if (device == NULL)
 730                 return -ENODEV;
 731
 732         dev = device->dev;
 733         lp = netdev_priv(dev);
 734         if (lp->fd > 0)
 735                 return -EBUSY;
 736         unregister_netdev(dev);
 737         platform_device_unregister(&device->pdev);
 738
 739         return 0;
 740 }
 741
 742 static struct mc_device net_mc = {
 743         .list           = LIST_HEAD_INIT(net_mc.list),
 744         .name           = "eth",
 745         .config         = net_config,
 746         .get_config     = NULL,
 747         .id             = net_id,
 748         .remove         = net_remove,
 749 };
 750
 751 #ifdef CONFIG_INET
 752 static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
 753                               void *ptr)
 754 {
 755         struct in_ifaddr *ifa = ptr;
 756         struct net_device *dev = ifa->ifa_dev->dev;
 757         struct uml_net_private *lp;
 758         void (*proc)(unsigned char *, unsigned char *, void *);
 759         unsigned char addr_buf[4], netmask_buf[4];
 760
 761         if (dev->netdev_ops->ndo_open != uml_net_open)
 762                 return NOTIFY_DONE;
 763
 764         lp = netdev_priv(dev);
 765
 766         proc = NULL;
 767         switch (event) {
 768         case NETDEV_UP:
 769                 proc = lp->add_address;
 770                 break;
 771         case NETDEV_DOWN:
 772                 proc = lp->delete_address;
 773                 break;
 774         }
 775         if (proc != NULL) {
 776                 memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
 777                 memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
 778                 (*proc)(addr_buf, netmask_buf, &lp->user);
 779         }
 780         return NOTIFY_DONE;
 781 }
 782
 783 /* uml_net_init shouldn't be called twice on two CPUs at the same time */
 784 static struct notifier_block uml_inetaddr_notifier = {
 785         .notifier_call          = uml_inetaddr_event,
 786 };
 787
 788 static void inet_register(void)
 789 {
 790         struct list_head *ele;
 791         struct uml_net_private *lp;
 792         struct in_device *ip;
 793         struct in_ifaddr *in;
 794
 795         register_inetaddr_notifier(&uml_inetaddr_notifier);
 796
 797         /* Devices may have been opened already, so the uml_inetaddr_notifier
 798          * didn't get a chance to run for them.  This fakes it so that
 799          * addresses which have already been set up get handled properly.
 800          */
 801         spin_lock(&opened_lock);
 802         list_for_each(ele, &opened) {
 803                 lp = list_entry(ele, struct uml_net_private, list);
 804                 ip = lp->dev->ip_ptr;
 805                 if (ip == NULL)
 806                         continue;
 807                 in = ip->ifa_list;
 808                 while (in != NULL) {
 809                         uml_inetaddr_event(NULL, NETDEV_UP, in);
 810                         in = in->ifa_next;
 811                 }
 812         }
 813         spin_unlock(&opened_lock);
 814 }
 815 #else
 816 static inline void inet_register(void)
 817 {
 818 }
 819 #endif
 820
 821 static int uml_net_init(void)
 822 {
 823         mconsole_register_dev(&net_mc);
 824         inet_register();
 825         return 0;
 826 }
 827
 828 __initcall(uml_net_init);
 829
 830 static void close_devices(void)
 831 {
 832         struct list_head *ele;
 833         struct uml_net_private *lp;
 834
 835         spin_lock(&opened_lock);
 836         list_for_each(ele, &opened) {
 837                 lp = list_entry(ele, struct uml_net_private, list);
 838                 free_irq(lp->dev->irq, lp->dev);
 839                 if ((lp->close != NULL) && (lp->fd >= 0))
 840                         (*lp->close)(lp->fd, &lp->user);
 841                 if (lp->remove != NULL)
 842                         (*lp->remove)(&lp->user);
 843         }
 844         spin_unlock(&opened_lock);
 845 }
 846
 847 __uml_exitcall(close_devices);
 848
 849 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
 850                                         void *),
 851                     void *arg)
 852 {
 853         struct net_device *dev = d;
 854         struct in_device *ip = dev->ip_ptr;
 855         struct in_ifaddr *in;
 856         unsigned char address[4], netmask[4];
 857
 858         if (ip == NULL) return;
 859         in = ip->ifa_list;
 860         while (in != NULL) {
 861                 memcpy(address, &in->ifa_address, sizeof(address));
 862                 memcpy(netmask, &in->ifa_mask, sizeof(netmask));
 863                 (*cb)(address, netmask, arg);
 864                 in = in->ifa_next;
 865         }
 866 }
 867
 868 int dev_netmask(void *d, void *m)
 869 {
 870         struct net_device *dev = d;
 871         struct in_device *ip = dev->ip_ptr;
 872         struct in_ifaddr *in;
 873         __be32 *mask_out = m;
 874
 875         if (ip == NULL)
 876                 return 1;
 877
 878         in = ip->ifa_list;
 879         if (in == NULL)
 880                 return 1;
 881
 882         *mask_out = in->ifa_mask;
 883         return 0;
 884 }
 885
 886 void *get_output_buffer(int *len_out)
 887 {
 888         void *ret;
 889
 890         ret = (void *) __get_free_pages(GFP_KERNEL, 0);
 891         if (ret) *len_out = PAGE_SIZE;
 892         else *len_out = 0;
 893         return ret;
 894 }
 895
 896 void free_output_buffer(void *buffer)
 897 {
 898         free_pages((unsigned long) buffer, 0);
 899 }
 900
 901 int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
 902                      char **gate_addr)
 903 {
 904         char *remain;
 905
 906         remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
 907         if (remain != NULL) {
 908                 printk(KERN_ERR "tap_setup_common - Extra garbage on "
 909                        "specification : '%s'\n", remain);
 910                 return 1;
 911         }
 912
 913         return 0;
 914 }
 915
 916 unsigned short eth_protocol(struct sk_buff *skb)
 917 {
 918         return eth_type_trans(skb, skb->dev);
 919 }