linux/arch/um/drivers/net_kern.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
   5 * James Leu (jleu@mindspring.net).
   6 * Copyright (C) 2001 by various other people who didn't put their name here.
   7 */
   8
   9#include <linux/memblock.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
  30static DEFINE_SPINLOCK(opened_lock);
  31static 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 */
  41static DEFINE_SPINLOCK(drop_lock);
  42static struct sk_buff *drop_skb;
  43static int drop_max;
  44
  45static 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;
  67out:
  68        spin_unlock_irqrestore(&drop_lock, flags);
  69
  70        return err;
  71}
  72
  73static 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
 108static 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
 115static 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        }
 140out:
 141        spin_unlock(&lp->lock);
 142        return IRQ_HANDLED;
 143}
 144
 145static int uml_net_open(struct net_device *dev)
 146{
 147        struct uml_net_private *lp = netdev_priv(dev);
 148        int err;
 149
 150        if (lp->fd >= 0) {
 151                err = -ENXIO;
 152                goto out;
 153        }
 154
 155        lp->fd = (*lp->open)(&lp->user);
 156        if (lp->fd < 0) {
 157                err = lp->fd;
 158                goto out;
 159        }
 160
 161        err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
 162                             IRQF_SHARED, dev->name, dev);
 163        if (err != 0) {
 164                printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
 165                err = -ENETUNREACH;
 166                goto out_close;
 167        }
 168
 169        netif_start_queue(dev);
 170
 171        /* clear buffer - it can happen that the host side of the interface
 172         * is full when we get here.  In this case, new data is never queued,
 173         * SIGIOs never arrive, and the net never works.
 174         */
 175        while ((err = uml_net_rx(dev)) > 0) ;
 176
 177        spin_lock(&opened_lock);
 178        list_add(&lp->list, &opened);
 179        spin_unlock(&opened_lock);
 180
 181        return 0;
 182out_close:
 183        if (lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
 184        lp->fd = -1;
 185out:
 186        return err;
 187}
 188
 189static int uml_net_close(struct net_device *dev)
 190{
 191        struct uml_net_private *lp = netdev_priv(dev);
 192
 193        netif_stop_queue(dev);
 194
 195        um_free_irq(dev->irq, dev);
 196        if (lp->close != NULL)
 197                (*lp->close)(lp->fd, &lp->user);
 198        lp->fd = -1;
 199
 200        spin_lock(&opened_lock);
 201        list_del(&lp->list);
 202        spin_unlock(&opened_lock);
 203
 204        return 0;
 205}
 206
 207static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 208{
 209        struct uml_net_private *lp = netdev_priv(dev);
 210        unsigned long flags;
 211        int len;
 212
 213        netif_stop_queue(dev);
 214
 215        spin_lock_irqsave(&lp->lock, flags);
 216
 217        len = (*lp->write)(lp->fd, skb, lp);
 218        skb_tx_timestamp(skb);
 219
 220        if (len == skb->len) {
 221                dev->stats.tx_packets++;
 222                dev->stats.tx_bytes += skb->len;
 223                netif_trans_update(dev);
 224                netif_start_queue(dev);
 225
 226                /* this is normally done in the interrupt when tx finishes */
 227                netif_wake_queue(dev);
 228        }
 229        else if (len == 0) {
 230                netif_start_queue(dev);
 231                dev->stats.tx_dropped++;
 232        }
 233        else {
 234                netif_start_queue(dev);
 235                printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
 236        }
 237
 238        spin_unlock_irqrestore(&lp->lock, flags);
 239
 240        dev_consume_skb_any(skb);
 241
 242        return NETDEV_TX_OK;
 243}
 244
 245static void uml_net_set_multicast_list(struct net_device *dev)
 246{
 247        return;
 248}
 249
 250static void uml_net_tx_timeout(struct net_device *dev, unsigned int txqueue)
 251{
 252        netif_trans_update(dev);
 253        netif_wake_queue(dev);
 254}
 255
 256#ifdef CONFIG_NET_POLL_CONTROLLER
 257static void uml_net_poll_controller(struct net_device *dev)
 258{
 259        disable_irq(dev->irq);
 260        uml_net_interrupt(dev->irq, dev);
 261        enable_irq(dev->irq);
 262}
 263#endif
 264
 265static void uml_net_get_drvinfo(struct net_device *dev,
 266                                struct ethtool_drvinfo *info)
 267{
 268        strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
 269}
 270
 271static const struct ethtool_ops uml_net_ethtool_ops = {
 272        .get_drvinfo    = uml_net_get_drvinfo,
 273        .get_link       = ethtool_op_get_link,
 274        .get_ts_info    = ethtool_op_get_ts_info,
 275};
 276
 277void uml_net_setup_etheraddr(struct net_device *dev, char *str)
 278{
 279        unsigned char *addr = dev->dev_addr;
 280        char *end;
 281        int i;
 282
 283        if (str == NULL)
 284                goto random;
 285
 286        for (i = 0; i < 6; i++) {
 287                addr[i] = simple_strtoul(str, &end, 16);
 288                if ((end == str) ||
 289                   ((*end != ':') && (*end != ',') && (*end != '\0'))) {
 290                        printk(KERN_ERR
 291                               "setup_etheraddr: failed to parse '%s' "
 292                               "as an ethernet address\n", str);
 293                        goto random;
 294                }
 295                str = end + 1;
 296        }
 297        if (is_multicast_ether_addr(addr)) {
 298                printk(KERN_ERR
 299                       "Attempt to assign a multicast ethernet address to a "
 300                       "device disallowed\n");
 301                goto random;
 302        }
 303        if (!is_valid_ether_addr(addr)) {
 304                printk(KERN_ERR
 305                       "Attempt to assign an invalid ethernet address to a "
 306                       "device disallowed\n");
 307                goto random;
 308        }
 309        if (!is_local_ether_addr(addr)) {
 310                printk(KERN_WARNING
 311                       "Warning: Assigning a globally valid ethernet "
 312                       "address to a device\n");
 313                printk(KERN_WARNING "You should set the 2nd rightmost bit in "
 314                       "the first byte of the MAC,\n");
 315                printk(KERN_WARNING "i.e. %02x:%02x:%02x:%02x:%02x:%02x\n",
 316                       addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4],
 317                       addr[5]);
 318        }
 319        return;
 320
 321random:
 322        printk(KERN_INFO
 323               "Choosing a random ethernet address for device %s\n", dev->name);
 324        eth_hw_addr_random(dev);
 325}
 326
 327static DEFINE_SPINLOCK(devices_lock);
 328static LIST_HEAD(devices);
 329
 330static struct platform_driver uml_net_driver = {
 331        .driver = {
 332                .name  = DRIVER_NAME,
 333        },
 334};
 335
 336static void net_device_release(struct device *dev)
 337{
 338        struct uml_net *device = dev_get_drvdata(dev);
 339        struct net_device *netdev = device->dev;
 340        struct uml_net_private *lp = netdev_priv(netdev);
 341
 342        if (lp->remove != NULL)
 343                (*lp->remove)(&lp->user);
 344        list_del(&device->list);
 345        kfree(device);
 346        free_netdev(netdev);
 347}
 348
 349static const struct net_device_ops uml_netdev_ops = {
 350        .ndo_open               = uml_net_open,
 351        .ndo_stop               = uml_net_close,
 352        .ndo_start_xmit         = uml_net_start_xmit,
 353        .ndo_set_rx_mode        = uml_net_set_multicast_list,
 354        .ndo_tx_timeout         = uml_net_tx_timeout,
 355        .ndo_set_mac_address    = eth_mac_addr,
 356        .ndo_validate_addr      = eth_validate_addr,
 357#ifdef CONFIG_NET_POLL_CONTROLLER
 358        .ndo_poll_controller = uml_net_poll_controller,
 359#endif
 360};
 361
 362/*
 363 * Ensures that platform_driver_register is called only once by
 364 * eth_configure.  Will be set in an initcall.
 365 */
 366static int driver_registered;
 367
 368static void eth_configure(int n, void *init, char *mac,
 369                          struct transport *transport, gfp_t gfp_mask)
 370{
 371        struct uml_net *device;
 372        struct net_device *dev;
 373        struct uml_net_private *lp;
 374        int err, size;
 375
 376        size = transport->private_size + sizeof(struct uml_net_private);
 377
 378        device = kzalloc(sizeof(*device), gfp_mask);
 379        if (device == NULL) {
 380                printk(KERN_ERR "eth_configure failed to allocate struct "
 381                       "uml_net\n");
 382                return;
 383        }
 384
 385        dev = alloc_etherdev(size);
 386        if (dev == NULL) {
 387                printk(KERN_ERR "eth_configure: failed to allocate struct "
 388                       "net_device for eth%d\n", n);
 389                goto out_free_device;
 390        }
 391
 392        INIT_LIST_HEAD(&device->list);
 393        device->index = n;
 394
 395        /* If this name ends up conflicting with an existing registered
 396         * netdevice, that is OK, register_netdev{,ice}() will notice this
 397         * and fail.
 398         */
 399        snprintf(dev->name, sizeof(dev->name), "eth%d", n);
 400
 401        uml_net_setup_etheraddr(dev, mac);
 402
 403        printk(KERN_INFO "Netdevice %d (%pM) : ", n, dev->dev_addr);
 404
 405        lp = netdev_priv(dev);
 406        /* This points to the transport private data. It's still clear, but we
 407         * must memset it to 0 *now*. Let's help the drivers. */
 408        memset(lp, 0, size);
 409        INIT_WORK(&lp->work, uml_dev_close);
 410
 411        /* sysfs register */
 412        if (!driver_registered) {
 413                platform_driver_register(&uml_net_driver);
 414                driver_registered = 1;
 415        }
 416        device->pdev.id = n;
 417        device->pdev.name = DRIVER_NAME;
 418        device->pdev.dev.release = net_device_release;
 419        dev_set_drvdata(&device->pdev.dev, device);
 420        if (platform_device_register(&device->pdev))
 421                goto out_free_netdev;
 422        SET_NETDEV_DEV(dev,&device->pdev.dev);
 423
 424        device->dev = dev;
 425
 426        /*
 427         * These just fill in a data structure, so there's no failure
 428         * to be worried about.
 429         */
 430        (*transport->kern->init)(dev, init);
 431
 432        *lp = ((struct uml_net_private)
 433                { .list                 = LIST_HEAD_INIT(lp->list),
 434                  .dev                  = dev,
 435                  .fd                   = -1,
 436                  .mac                  = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
 437                  .max_packet           = transport->user->max_packet,
 438                  .protocol             = transport->kern->protocol,
 439                  .open                 = transport->user->open,
 440                  .close                = transport->user->close,
 441                  .remove               = transport->user->remove,
 442                  .read                 = transport->kern->read,
 443                  .write                = transport->kern->write,
 444                  .add_address          = transport->user->add_address,
 445                  .delete_address       = transport->user->delete_address });
 446
 447        spin_lock_init(&lp->lock);
 448        memcpy(lp->mac, dev->dev_addr, sizeof(lp->mac));
 449
 450        if ((transport->user->init != NULL) &&
 451            ((*transport->user->init)(&lp->user, dev) != 0))
 452                goto out_unregister;
 453
 454        dev->mtu = transport->user->mtu;
 455        dev->netdev_ops = &uml_netdev_ops;
 456        dev->ethtool_ops = &uml_net_ethtool_ops;
 457        dev->watchdog_timeo = (HZ >> 1);
 458        dev->irq = UM_ETH_IRQ;
 459
 460        err = update_drop_skb(lp->max_packet);
 461        if (err)
 462                goto out_undo_user_init;
 463
 464        rtnl_lock();
 465        err = register_netdevice(dev);
 466        rtnl_unlock();
 467        if (err)
 468                goto out_undo_user_init;
 469
 470        spin_lock(&devices_lock);
 471        list_add(&device->list, &devices);
 472        spin_unlock(&devices_lock);
 473
 474        return;
 475
 476out_undo_user_init:
 477        if (transport->user->remove != NULL)
 478                (*transport->user->remove)(&lp->user);
 479out_unregister:
 480        platform_device_unregister(&device->pdev);
 481        return; /* platform_device_unregister frees dev and device */
 482out_free_netdev:
 483        free_netdev(dev);
 484out_free_device:
 485        kfree(device);
 486}
 487
 488static struct uml_net *find_device(int n)
 489{
 490        struct uml_net *device;
 491        struct list_head *ele;
 492
 493        spin_lock(&devices_lock);
 494        list_for_each(ele, &devices) {
 495                device = list_entry(ele, struct uml_net, list);
 496                if (device->index == n)
 497                        goto out;
 498        }
 499        device = NULL;
 500 out:
 501        spin_unlock(&devices_lock);
 502        return device;
 503}
 504
 505static int eth_parse(char *str, int *index_out, char **str_out,
 506                     char **error_out)
 507{
 508        char *end;
 509        int n, err = -EINVAL;
 510
 511        n = simple_strtoul(str, &end, 0);
 512        if (end == str) {
 513                *error_out = "Bad device number";
 514                return err;
 515        }
 516
 517        str = end;
 518        if (*str != '=') {
 519                *error_out = "Expected '=' after device number";
 520                return err;
 521        }
 522
 523        str++;
 524        if (find_device(n)) {
 525                *error_out = "Device already configured";
 526                return err;
 527        }
 528
 529        *index_out = n;
 530        *str_out = str;
 531        return 0;
 532}
 533
 534struct eth_init {
 535        struct list_head list;
 536        char *init;
 537        int index;
 538};
 539
 540static DEFINE_SPINLOCK(transports_lock);
 541static LIST_HEAD(transports);
 542
 543/* Filled in during early boot */
 544static LIST_HEAD(eth_cmd_line);
 545
 546static int check_transport(struct transport *transport, char *eth, int n,
 547                           void **init_out, char **mac_out, gfp_t gfp_mask)
 548{
 549        int len;
 550
 551        len = strlen(transport->name);
 552        if (strncmp(eth, transport->name, len))
 553                return 0;
 554
 555        eth += len;
 556        if (*eth == ',')
 557                eth++;
 558        else if (*eth != '\0')
 559                return 0;
 560
 561        *init_out = kmalloc(transport->setup_size, gfp_mask);
 562        if (*init_out == NULL)
 563                return 1;
 564
 565        if (!transport->setup(eth, mac_out, *init_out)) {
 566                kfree(*init_out);
 567                *init_out = NULL;
 568        }
 569        return 1;
 570}
 571
 572void register_transport(struct transport *new)
 573{
 574        struct list_head *ele, *next;
 575        struct eth_init *eth;
 576        void *init;
 577        char *mac = NULL;
 578        int match;
 579
 580        spin_lock(&transports_lock);
 581        BUG_ON(!list_empty(&new->list));
 582        list_add(&new->list, &transports);
 583        spin_unlock(&transports_lock);
 584
 585        list_for_each_safe(ele, next, &eth_cmd_line) {
 586                eth = list_entry(ele, struct eth_init, list);
 587                match = check_transport(new, eth->init, eth->index, &init,
 588                                        &mac, GFP_KERNEL);
 589                if (!match)
 590                        continue;
 591                else if (init != NULL) {
 592                        eth_configure(eth->index, init, mac, new, GFP_KERNEL);
 593                        kfree(init);
 594                }
 595                list_del(&eth->list);
 596        }
 597}
 598
 599static int eth_setup_common(char *str, int index)
 600{
 601        struct list_head *ele;
 602        struct transport *transport;
 603        void *init;
 604        char *mac = NULL;
 605        int found = 0;
 606
 607        spin_lock(&transports_lock);
 608        list_for_each(ele, &transports) {
 609                transport = list_entry(ele, struct transport, list);
 610                if (!check_transport(transport, str, index, &init,
 611                                        &mac, GFP_ATOMIC))
 612                        continue;
 613                if (init != NULL) {
 614                        eth_configure(index, init, mac, transport, GFP_ATOMIC);
 615                        kfree(init);
 616                }
 617                found = 1;
 618                break;
 619        }
 620
 621        spin_unlock(&transports_lock);
 622        return found;
 623}
 624
 625static int __init eth_setup(char *str)
 626{
 627        struct eth_init *new;
 628        char *error;
 629        int n, err;
 630
 631        err = eth_parse(str, &n, &str, &error);
 632        if (err) {
 633                printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
 634                       str, error);
 635                return 1;
 636        }
 637
 638        new = memblock_alloc(sizeof(*new), SMP_CACHE_BYTES);
 639        if (!new)
 640                panic("%s: Failed to allocate %zu bytes\n", __func__,
 641                      sizeof(*new));
 642
 643        INIT_LIST_HEAD(&new->list);
 644        new->index = n;
 645        new->init = str;
 646
 647        list_add_tail(&new->list, &eth_cmd_line);
 648        return 1;
 649}
 650
 651__setup("eth", eth_setup);
 652__uml_help(eth_setup,
 653"eth[0-9]+=<transport>,<options>\n"
 654"    Configure a network device.\n\n"
 655);
 656
 657static int net_config(char *str, char **error_out)
 658{
 659        int n, err;
 660
 661        err = eth_parse(str, &n, &str, error_out);
 662        if (err)
 663                return err;
 664
 665        /* This string is broken up and the pieces used by the underlying
 666         * driver.  So, it is freed only if eth_setup_common fails.
 667         */
 668        str = kstrdup(str, GFP_KERNEL);
 669        if (str == NULL) {
 670                *error_out = "net_config failed to strdup string";
 671                return -ENOMEM;
 672        }
 673        err = !eth_setup_common(str, n);
 674        if (err)
 675                kfree(str);
 676        return err;
 677}
 678
 679static int net_id(char **str, int *start_out, int *end_out)
 680{
 681        char *end;
 682        int n;
 683
 684        n = simple_strtoul(*str, &end, 0);
 685        if ((*end != '\0') || (end == *str))
 686                return -1;
 687
 688        *start_out = n;
 689        *end_out = n;
 690        *str = end;
 691        return n;
 692}
 693
 694static int net_remove(int n, char **error_out)
 695{
 696        struct uml_net *device;
 697        struct net_device *dev;
 698        struct uml_net_private *lp;
 699
 700        device = find_device(n);
 701        if (device == NULL)
 702                return -ENODEV;
 703
 704        dev = device->dev;
 705        lp = netdev_priv(dev);
 706        if (lp->fd > 0)
 707                return -EBUSY;
 708        unregister_netdev(dev);
 709        platform_device_unregister(&device->pdev);
 710
 711        return 0;
 712}
 713
 714static struct mc_device net_mc = {
 715        .list           = LIST_HEAD_INIT(net_mc.list),
 716        .name           = "eth",
 717        .config         = net_config,
 718        .get_config     = NULL,
 719        .id             = net_id,
 720        .remove         = net_remove,
 721};
 722
 723#ifdef CONFIG_INET
 724static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
 725                              void *ptr)
 726{
 727        struct in_ifaddr *ifa = ptr;
 728        struct net_device *dev = ifa->ifa_dev->dev;
 729        struct uml_net_private *lp;
 730        void (*proc)(unsigned char *, unsigned char *, void *);
 731        unsigned char addr_buf[4], netmask_buf[4];
 732
 733        if (dev->netdev_ops->ndo_open != uml_net_open)
 734                return NOTIFY_DONE;
 735
 736        lp = netdev_priv(dev);
 737
 738        proc = NULL;
 739        switch (event) {
 740        case NETDEV_UP:
 741                proc = lp->add_address;
 742                break;
 743        case NETDEV_DOWN:
 744                proc = lp->delete_address;
 745                break;
 746        }
 747        if (proc != NULL) {
 748                memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
 749                memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
 750                (*proc)(addr_buf, netmask_buf, &lp->user);
 751        }
 752        return NOTIFY_DONE;
 753}
 754
 755/* uml_net_init shouldn't be called twice on two CPUs at the same time */
 756static struct notifier_block uml_inetaddr_notifier = {
 757        .notifier_call          = uml_inetaddr_event,
 758};
 759
 760static void inet_register(void)
 761{
 762        struct list_head *ele;
 763        struct uml_net_private *lp;
 764        struct in_device *ip;
 765        struct in_ifaddr *in;
 766
 767        register_inetaddr_notifier(&uml_inetaddr_notifier);
 768
 769        /* Devices may have been opened already, so the uml_inetaddr_notifier
 770         * didn't get a chance to run for them.  This fakes it so that
 771         * addresses which have already been set up get handled properly.
 772         */
 773        spin_lock(&opened_lock);
 774        list_for_each(ele, &opened) {
 775                lp = list_entry(ele, struct uml_net_private, list);
 776                ip = lp->dev->ip_ptr;
 777                if (ip == NULL)
 778                        continue;
 779                in = ip->ifa_list;
 780                while (in != NULL) {
 781                        uml_inetaddr_event(NULL, NETDEV_UP, in);
 782                        in = in->ifa_next;
 783                }
 784        }
 785        spin_unlock(&opened_lock);
 786}
 787#else
 788static inline void inet_register(void)
 789{
 790}
 791#endif
 792
 793static int uml_net_init(void)
 794{
 795        mconsole_register_dev(&net_mc);
 796        inet_register();
 797        return 0;
 798}
 799
 800__initcall(uml_net_init);
 801
 802static void close_devices(void)
 803{
 804        struct list_head *ele;
 805        struct uml_net_private *lp;
 806
 807        spin_lock(&opened_lock);
 808        list_for_each(ele, &opened) {
 809                lp = list_entry(ele, struct uml_net_private, list);
 810                um_free_irq(lp->dev->irq, lp->dev);
 811                if ((lp->close != NULL) && (lp->fd >= 0))
 812                        (*lp->close)(lp->fd, &lp->user);
 813                if (lp->remove != NULL)
 814                        (*lp->remove)(&lp->user);
 815        }
 816        spin_unlock(&opened_lock);
 817}
 818
 819__uml_exitcall(close_devices);
 820
 821void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
 822                                        void *),
 823                    void *arg)
 824{
 825        struct net_device *dev = d;
 826        struct in_device *ip = dev->ip_ptr;
 827        struct in_ifaddr *in;
 828        unsigned char address[4], netmask[4];
 829
 830        if (ip == NULL) return;
 831        in = ip->ifa_list;
 832        while (in != NULL) {
 833                memcpy(address, &in->ifa_address, sizeof(address));
 834                memcpy(netmask, &in->ifa_mask, sizeof(netmask));
 835                (*cb)(address, netmask, arg);
 836                in = in->ifa_next;
 837        }
 838}
 839
 840int dev_netmask(void *d, void *m)
 841{
 842        struct net_device *dev = d;
 843        struct in_device *ip = dev->ip_ptr;
 844        struct in_ifaddr *in;
 845        __be32 *mask_out = m;
 846
 847        if (ip == NULL)
 848                return 1;
 849
 850        in = ip->ifa_list;
 851        if (in == NULL)
 852                return 1;
 853
 854        *mask_out = in->ifa_mask;
 855        return 0;
 856}
 857
 858void *get_output_buffer(int *len_out)
 859{
 860        void *ret;
 861
 862        ret = (void *) __get_free_pages(GFP_KERNEL, 0);
 863        if (ret) *len_out = PAGE_SIZE;
 864        else *len_out = 0;
 865        return ret;
 866}
 867
 868void free_output_buffer(void *buffer)
 869{
 870        free_pages((unsigned long) buffer, 0);
 871}
 872
 873int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
 874                     char **gate_addr)
 875{
 876        char *remain;
 877
 878        remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
 879        if (remain != NULL) {
 880                printk(KERN_ERR "tap_setup_common - Extra garbage on "
 881                       "specification : '%s'\n", remain);
 882                return 1;
 883        }
 884
 885        return 0;
 886}
 887
 888unsigned short eth_protocol(struct sk_buff *skb)
 889{
 890        return eth_type_trans(skb, skb->dev);
 891}
 892