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