net/atm/br2684.c

   1 /*
   2  * Ethernet netdevice using ATM AAL5 as underlying carrier
   3  * (RFC1483 obsoleted by RFC2684) for Linux
   4  *
   5  * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
   6  *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/list.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/ip.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/slab.h>
  22 #include <net/arp.h>
  23 #include <linux/atm.h>
  24 #include <linux/atmdev.h>
  25 #include <linux/capability.h>
  26 #include <linux/seq_file.h>
  27
  28 #include <linux/atmbr2684.h>
  29
  30 #include "common.h"
  31
  32 static void skb_debug(const struct sk_buff *skb)
  33 {
  34 #ifdef SKB_DEBUG
  35 #define NUM2PRINT 50
  36         print_hex_dump(KERN_DEBUG, "br2684: skb: ", DUMP_OFFSET,
  37                        16, 1, skb->data, min(NUM2PRINT, skb->len), true);
  38 #endif
  39 }
  40
  41 #define BR2684_ETHERTYPE_LEN    2
  42 #define BR2684_PAD_LEN          2
  43
  44 #define LLC             0xaa, 0xaa, 0x03
  45 #define SNAP_BRIDGED    0x00, 0x80, 0xc2
  46 #define SNAP_ROUTED     0x00, 0x00, 0x00
  47 #define PID_ETHERNET    0x00, 0x07
  48 #define ETHERTYPE_IPV4  0x08, 0x00
  49 #define ETHERTYPE_IPV6  0x86, 0xdd
  50 #define PAD_BRIDGED     0x00, 0x00
  51
  52 static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
  53 static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
  54 static const unsigned char llc_oui_pid_pad[] =
  55                         { LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
  56 static const unsigned char pad[] = { PAD_BRIDGED };
  57 static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
  58 static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
  59
  60 enum br2684_encaps {
  61         e_vc = BR2684_ENCAPS_VC,
  62         e_llc = BR2684_ENCAPS_LLC,
  63 };
  64
  65 struct br2684_vcc {
  66         struct atm_vcc *atmvcc;
  67         struct net_device *device;
  68         /* keep old push, pop functions for chaining */
  69         void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
  70         void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
  71         void (*old_release_cb)(struct atm_vcc *vcc);
  72         struct module *old_owner;
  73         enum br2684_encaps encaps;
  74         struct list_head brvccs;
  75 #ifdef CONFIG_ATM_BR2684_IPFILTER
  76         struct br2684_filter filter;
  77 #endif /* CONFIG_ATM_BR2684_IPFILTER */
  78         unsigned int copies_needed, copies_failed;
  79         atomic_t qspace;
  80 };
  81
  82 struct br2684_dev {
  83         struct net_device *net_dev;
  84         struct list_head br2684_devs;
  85         int number;
  86         struct list_head brvccs;        /* one device <=> one vcc (before xmas) */
  87         int mac_was_set;
  88         enum br2684_payload payload;
  89 };
  90
  91 /*
  92  * This lock should be held for writing any time the list of devices or
  93  * their attached vcc's could be altered.  It should be held for reading
  94  * any time these are being queried.  Note that we sometimes need to
  95  * do read-locking under interrupt context, so write locking must block
  96  * the current CPU's interrupts
  97  */
  98 static DEFINE_RWLOCK(devs_lock);
  99
 100 static LIST_HEAD(br2684_devs);
 101
 102 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
 103 {
 104         return netdev_priv(net_dev);
 105 }
 106
 107 static inline struct net_device *list_entry_brdev(const struct list_head *le)
 108 {
 109         return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
 110 }
 111
 112 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
 113 {
 114         return (struct br2684_vcc *)(atmvcc->user_back);
 115 }
 116
 117 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
 118 {
 119         return list_entry(le, struct br2684_vcc, brvccs);
 120 }
 121
 122 /* Caller should hold read_lock(&devs_lock) */
 123 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
 124 {
 125         struct list_head *lh;
 126         struct net_device *net_dev;
 127         switch (s->method) {
 128         case BR2684_FIND_BYNUM:
 129                 list_for_each(lh, &br2684_devs) {
 130                         net_dev = list_entry_brdev(lh);
 131                         if (BRPRIV(net_dev)->number == s->spec.devnum)
 132                                 return net_dev;
 133                 }
 134                 break;
 135         case BR2684_FIND_BYIFNAME:
 136                 list_for_each(lh, &br2684_devs) {
 137                         net_dev = list_entry_brdev(lh);
 138                         if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
 139                                 return net_dev;
 140                 }
 141                 break;
 142         }
 143         return NULL;
 144 }
 145
 146 static int atm_dev_event(struct notifier_block *this, unsigned long event,
 147                  void *arg)
 148 {
 149         struct atm_dev *atm_dev = arg;
 150         struct list_head *lh;
 151         struct net_device *net_dev;
 152         struct br2684_vcc *brvcc;
 153         struct atm_vcc *atm_vcc;
 154         unsigned long flags;
 155
 156         pr_debug("event=%ld dev=%p\n", event, atm_dev);
 157
 158         read_lock_irqsave(&devs_lock, flags);
 159         list_for_each(lh, &br2684_devs) {
 160                 net_dev = list_entry_brdev(lh);
 161
 162                 list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
 163                         atm_vcc = brvcc->atmvcc;
 164                         if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
 165
 166                                 if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
 167                                         netif_carrier_off(net_dev);
 168                                 else
 169                                         netif_carrier_on(net_dev);
 170
 171                         }
 172                 }
 173         }
 174         read_unlock_irqrestore(&devs_lock, flags);
 175
 176         return NOTIFY_DONE;
 177 }
 178
 179 static struct notifier_block atm_dev_notifier = {
 180         .notifier_call = atm_dev_event,
 181 };
 182
 183 /* chained vcc->pop function.  Check if we should wake the netif_queue */
 184 static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 185 {
 186         struct br2684_vcc *brvcc = BR2684_VCC(vcc);
 187
 188         pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
 189         brvcc->old_pop(vcc, skb);
 190
 191         /* If the queue space just went up from zero, wake */
 192         if (atomic_inc_return(&brvcc->qspace) == 1)
 193                 netif_wake_queue(brvcc->device);
 194 }
 195
 196 /*
 197  * Send a packet out a particular vcc.  Not to useful right now, but paves
 198  * the way for multiple vcc's per itf.  Returns true if we can send,
 199  * otherwise false
 200  */
 201 static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
 202                            struct br2684_vcc *brvcc)
 203 {
 204         struct br2684_dev *brdev = BRPRIV(dev);
 205         struct atm_vcc *atmvcc;
 206         int minheadroom = (brvcc->encaps == e_llc) ?
 207                 ((brdev->payload == p_bridged) ?
 208                         sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) :
 209                 ((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0);
 210
 211         if (skb_headroom(skb) < minheadroom) {
 212                 struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
 213                 brvcc->copies_needed++;
 214                 dev_kfree_skb(skb);
 215                 if (skb2 == NULL) {
 216                         brvcc->copies_failed++;
 217                         return 0;
 218                 }
 219                 skb = skb2;
 220         }
 221
 222         if (brvcc->encaps == e_llc) {
 223                 if (brdev->payload == p_bridged) {
 224                         skb_push(skb, sizeof(llc_oui_pid_pad));
 225                         skb_copy_to_linear_data(skb, llc_oui_pid_pad,
 226                                                 sizeof(llc_oui_pid_pad));
 227                 } else if (brdev->payload == p_routed) {
 228                         unsigned short prot = ntohs(skb->protocol);
 229
 230                         skb_push(skb, sizeof(llc_oui_ipv4));
 231                         switch (prot) {
 232                         case ETH_P_IP:
 233                                 skb_copy_to_linear_data(skb, llc_oui_ipv4,
 234                                                         sizeof(llc_oui_ipv4));
 235                                 break;
 236                         case ETH_P_IPV6:
 237                                 skb_copy_to_linear_data(skb, llc_oui_ipv6,
 238                                                         sizeof(llc_oui_ipv6));
 239                                 break;
 240                         default:
 241                                 dev_kfree_skb(skb);
 242                                 return 0;
 243                         }
 244                 }
 245         } else { /* e_vc */
 246                 if (brdev->payload == p_bridged) {
 247                         skb_push(skb, 2);
 248                         memset(skb->data, 0, 2);
 249                 }
 250         }
 251         skb_debug(skb);
 252
 253         ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
 254         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
 255         atm_account_tx(atmvcc, skb);
 256         dev->stats.tx_packets++;
 257         dev->stats.tx_bytes += skb->len;
 258
 259         if (atomic_dec_return(&brvcc->qspace) < 1) {
 260                 /* No more please! */
 261                 netif_stop_queue(brvcc->device);
 262                 /* We might have raced with br2684_pop() */
 263                 if (unlikely(atomic_read(&brvcc->qspace) > 0))
 264                         netif_wake_queue(brvcc->device);
 265         }
 266
 267         /* If this fails immediately, the skb will be freed and br2684_pop()
 268            will wake the queue if appropriate. Just return an error so that
 269            the stats are updated correctly */
 270         return !atmvcc->send(atmvcc, skb);
 271 }
 272
 273 static void br2684_release_cb(struct atm_vcc *atmvcc)
 274 {
 275         struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
 276
 277         if (atomic_read(&brvcc->qspace) > 0)
 278                 netif_wake_queue(brvcc->device);
 279
 280         if (brvcc->old_release_cb)
 281                 brvcc->old_release_cb(atmvcc);
 282 }
 283
 284 static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
 285                                                    const struct br2684_dev *brdev)
 286 {
 287         return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);        /* 1 vcc/dev right now */
 288 }
 289
 290 static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
 291                                      struct net_device *dev)
 292 {
 293         struct br2684_dev *brdev = BRPRIV(dev);
 294         struct br2684_vcc *brvcc;
 295         struct atm_vcc *atmvcc;
 296         netdev_tx_t ret = NETDEV_TX_OK;
 297
 298         pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
 299         read_lock(&devs_lock);
 300         brvcc = pick_outgoing_vcc(skb, brdev);
 301         if (brvcc == NULL) {
 302                 pr_debug("no vcc attached to dev %s\n", dev->name);
 303                 dev->stats.tx_errors++;
 304                 dev->stats.tx_carrier_errors++;
 305                 /* netif_stop_queue(dev); */
 306                 dev_kfree_skb(skb);
 307                 goto out_devs;
 308         }
 309         atmvcc = brvcc->atmvcc;
 310
 311         bh_lock_sock(sk_atm(atmvcc));
 312
 313         if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
 314             test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
 315             !test_bit(ATM_VF_READY, &atmvcc->flags)) {
 316                 dev->stats.tx_dropped++;
 317                 dev_kfree_skb(skb);
 318                 goto out;
 319         }
 320
 321         if (sock_owned_by_user(sk_atm(atmvcc))) {
 322                 netif_stop_queue(brvcc->device);
 323                 ret = NETDEV_TX_BUSY;
 324                 goto out;
 325         }
 326
 327         if (!br2684_xmit_vcc(skb, dev, brvcc)) {
 328                 /*
 329                  * We should probably use netif_*_queue() here, but that
 330                  * involves added complication.  We need to walk before
 331                  * we can run.
 332                  *
 333                  * Don't free here! this pointer might be no longer valid!
 334                  */
 335                 dev->stats.tx_errors++;
 336                 dev->stats.tx_fifo_errors++;
 337         }
 338  out:
 339         bh_unlock_sock(sk_atm(atmvcc));
 340  out_devs:
 341         read_unlock(&devs_lock);
 342         return ret;
 343 }
 344
 345 /*
 346  * We remember when the MAC gets set, so we don't override it later with
 347  * the ESI of the ATM card of the first VC
 348  */
 349 static int br2684_mac_addr(struct net_device *dev, void *p)
 350 {
 351         int err = eth_mac_addr(dev, p);
 352         if (!err)
 353                 BRPRIV(dev)->mac_was_set = 1;
 354         return err;
 355 }
 356
 357 #ifdef CONFIG_ATM_BR2684_IPFILTER
 358 /* this IOCTL is experimental. */
 359 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
 360 {
 361         struct br2684_vcc *brvcc;
 362         struct br2684_filter_set fs;
 363
 364         if (copy_from_user(&fs, arg, sizeof fs))
 365                 return -EFAULT;
 366         if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
 367                 /*
 368                  * This is really a per-vcc thing, but we can also search
 369                  * by device.
 370                  */
 371                 struct br2684_dev *brdev;
 372                 read_lock(&devs_lock);
 373                 brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
 374                 if (brdev == NULL || list_empty(&brdev->brvccs) ||
 375                     brdev->brvccs.next != brdev->brvccs.prev)   /* >1 VCC */
 376                         brvcc = NULL;
 377                 else
 378                         brvcc = list_entry_brvcc(brdev->brvccs.next);
 379                 read_unlock(&devs_lock);
 380                 if (brvcc == NULL)
 381                         return -ESRCH;
 382         } else
 383                 brvcc = BR2684_VCC(atmvcc);
 384         memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
 385         return 0;
 386 }
 387
 388 /* Returns 1 if packet should be dropped */
 389 static inline int
 390 packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
 391 {
 392         if (brvcc->filter.netmask == 0)
 393                 return 0;       /* no filter in place */
 394         if (type == htons(ETH_P_IP) &&
 395             (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
 396              netmask) == brvcc->filter.prefix)
 397                 return 0;
 398         if (type == htons(ETH_P_ARP))
 399                 return 0;
 400         /*
 401          * TODO: we should probably filter ARPs too.. don't want to have
 402          * them returning values that don't make sense, or is that ok?
 403          */
 404         return 1;               /* drop */
 405 }
 406 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 407
 408 static void br2684_close_vcc(struct br2684_vcc *brvcc)
 409 {
 410         pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
 411         write_lock_irq(&devs_lock);
 412         list_del(&brvcc->brvccs);
 413         write_unlock_irq(&devs_lock);
 414         brvcc->atmvcc->user_back = NULL;        /* what about vcc->recvq ??? */
 415         brvcc->atmvcc->release_cb = brvcc->old_release_cb;
 416         brvcc->old_push(brvcc->atmvcc, NULL);   /* pass on the bad news */
 417         module_put(brvcc->old_owner);
 418         kfree(brvcc);
 419 }
 420
 421 /* when AAL5 PDU comes in: */
 422 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
 423 {
 424         struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
 425         struct net_device *net_dev = brvcc->device;
 426         struct br2684_dev *brdev = BRPRIV(net_dev);
 427
 428         pr_debug("\n");
 429
 430         if (unlikely(skb == NULL)) {
 431                 /* skb==NULL means VCC is being destroyed */
 432                 br2684_close_vcc(brvcc);
 433                 if (list_empty(&brdev->brvccs)) {
 434                         write_lock_irq(&devs_lock);
 435                         list_del(&brdev->br2684_devs);
 436                         write_unlock_irq(&devs_lock);
 437                         unregister_netdev(net_dev);
 438                         free_netdev(net_dev);
 439                 }
 440                 return;
 441         }
 442
 443         skb_debug(skb);
 444         atm_return(atmvcc, skb->truesize);
 445         pr_debug("skb from brdev %p\n", brdev);
 446         if (brvcc->encaps == e_llc) {
 447
 448                 if (skb->len > 7 && skb->data[7] == 0x01)
 449                         __skb_trim(skb, skb->len - 4);
 450
 451                 /* accept packets that have "ipv[46]" in the snap header */
 452                 if ((skb->len >= (sizeof(llc_oui_ipv4))) &&
 453                     (memcmp(skb->data, llc_oui_ipv4,
 454                             sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
 455                         if (memcmp(skb->data + 6, ethertype_ipv6,
 456                                    sizeof(ethertype_ipv6)) == 0)
 457                                 skb->protocol = htons(ETH_P_IPV6);
 458                         else if (memcmp(skb->data + 6, ethertype_ipv4,
 459                                         sizeof(ethertype_ipv4)) == 0)
 460                                 skb->protocol = htons(ETH_P_IP);
 461                         else
 462                                 goto error;
 463                         skb_pull(skb, sizeof(llc_oui_ipv4));
 464                         skb_reset_network_header(skb);
 465                         skb->pkt_type = PACKET_HOST;
 466                 /*
 467                  * Let us waste some time for checking the encapsulation.
 468                  * Note, that only 7 char is checked so frames with a valid FCS
 469                  * are also accepted (but FCS is not checked of course).
 470                  */
 471                 } else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
 472                            (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
 473                         skb_pull(skb, sizeof(llc_oui_pid_pad));
 474                         skb->protocol = eth_type_trans(skb, net_dev);
 475                 } else
 476                         goto error;
 477
 478         } else { /* e_vc */
 479                 if (brdev->payload == p_routed) {
 480                         struct iphdr *iph;
 481
 482                         skb_reset_network_header(skb);
 483                         iph = ip_hdr(skb);
 484                         if (iph->version == 4)
 485                                 skb->protocol = htons(ETH_P_IP);
 486                         else if (iph->version == 6)
 487                                 skb->protocol = htons(ETH_P_IPV6);
 488                         else
 489                                 goto error;
 490                         skb->pkt_type = PACKET_HOST;
 491                 } else { /* p_bridged */
 492                         /* first 2 chars should be 0 */
 493                         if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0)
 494                                 goto error;
 495                         skb_pull(skb, BR2684_PAD_LEN);
 496                         skb->protocol = eth_type_trans(skb, net_dev);
 497                 }
 498         }
 499
 500 #ifdef CONFIG_ATM_BR2684_IPFILTER
 501         if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
 502                 goto dropped;
 503 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 504         skb->dev = net_dev;
 505         ATM_SKB(skb)->vcc = atmvcc;     /* needed ? */
 506         pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
 507         skb_debug(skb);
 508         /* sigh, interface is down? */
 509         if (unlikely(!(net_dev->flags & IFF_UP)))
 510                 goto dropped;
 511         net_dev->stats.rx_packets++;
 512         net_dev->stats.rx_bytes += skb->len;
 513         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 514         netif_rx(skb);
 515         return;
 516
 517 dropped:
 518         net_dev->stats.rx_dropped++;
 519         goto free_skb;
 520 error:
 521         net_dev->stats.rx_errors++;
 522 free_skb:
 523         dev_kfree_skb(skb);
 524 }
 525
 526 /*
 527  * Assign a vcc to a dev
 528  * Note: we do not have explicit unassign, but look at _push()
 529  */
 530 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 531 {
 532         struct br2684_vcc *brvcc;
 533         struct br2684_dev *brdev;
 534         struct net_device *net_dev;
 535         struct atm_backend_br2684 be;
 536         int err;
 537
 538         if (copy_from_user(&be, arg, sizeof be))
 539                 return -EFAULT;
 540         brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
 541         if (!brvcc)
 542                 return -ENOMEM;
 543         /*
 544          * Allow two packets in the ATM queue. One actually being sent, and one
 545          * for the ATM 'TX done' handler to send. It shouldn't take long to get
 546          * the next one from the netdev queue, when we need it. More than that
 547          * would be bufferbloat.
 548          */
 549         atomic_set(&brvcc->qspace, 2);
 550         write_lock_irq(&devs_lock);
 551         net_dev = br2684_find_dev(&be.ifspec);
 552         if (net_dev == NULL) {
 553                 pr_err("tried to attach to non-existent device\n");
 554                 err = -ENXIO;
 555                 goto error;
 556         }
 557         brdev = BRPRIV(net_dev);
 558         if (atmvcc->push == NULL) {
 559                 err = -EBADFD;
 560                 goto error;
 561         }
 562         if (!list_empty(&brdev->brvccs)) {
 563                 /* Only 1 VCC/dev right now */
 564                 err = -EEXIST;
 565                 goto error;
 566         }
 567         if (be.fcs_in != BR2684_FCSIN_NO ||
 568             be.fcs_out != BR2684_FCSOUT_NO ||
 569             be.fcs_auto || be.has_vpiid || be.send_padding ||
 570             (be.encaps != BR2684_ENCAPS_VC &&
 571              be.encaps != BR2684_ENCAPS_LLC) ||
 572             be.min_size != 0) {
 573                 err = -EINVAL;
 574                 goto error;
 575         }
 576         pr_debug("vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps, brvcc);
 577         if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
 578                 unsigned char *esi = atmvcc->dev->esi;
 579                 if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
 580                         memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
 581                 else
 582                         net_dev->dev_addr[2] = 1;
 583         }
 584         list_add(&brvcc->brvccs, &brdev->brvccs);
 585         write_unlock_irq(&devs_lock);
 586         brvcc->device = net_dev;
 587         brvcc->atmvcc = atmvcc;
 588         atmvcc->user_back = brvcc;
 589         brvcc->encaps = (enum br2684_encaps)be.encaps;
 590         brvcc->old_push = atmvcc->push;
 591         brvcc->old_pop = atmvcc->pop;
 592         brvcc->old_release_cb = atmvcc->release_cb;
 593         brvcc->old_owner = atmvcc->owner;
 594         barrier();
 595         atmvcc->push = br2684_push;
 596         atmvcc->pop = br2684_pop;
 597         atmvcc->release_cb = br2684_release_cb;
 598         atmvcc->owner = THIS_MODULE;
 599
 600         /* initialize netdev carrier state */
 601         if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
 602                 netif_carrier_off(net_dev);
 603         else
 604                 netif_carrier_on(net_dev);
 605
 606         __module_get(THIS_MODULE);
 607
 608         /* re-process everything received between connection setup and
 609            backend setup */
 610         vcc_process_recv_queue(atmvcc);
 611         return 0;
 612
 613 error:
 614         write_unlock_irq(&devs_lock);
 615         kfree(brvcc);
 616         return err;
 617 }
 618
 619 static const struct net_device_ops br2684_netdev_ops = {
 620         .ndo_start_xmit         = br2684_start_xmit,
 621         .ndo_set_mac_address    = br2684_mac_addr,
 622         .ndo_validate_addr      = eth_validate_addr,
 623 };
 624
 625 static const struct net_device_ops br2684_netdev_ops_routed = {
 626         .ndo_start_xmit         = br2684_start_xmit,
 627         .ndo_set_mac_address    = br2684_mac_addr,
 628 };
 629
 630 static void br2684_setup(struct net_device *netdev)
 631 {
 632         struct br2684_dev *brdev = BRPRIV(netdev);
 633
 634         ether_setup(netdev);
 635         netdev->hard_header_len += sizeof(llc_oui_pid_pad); /* worst case */
 636         brdev->net_dev = netdev;
 637
 638         netdev->netdev_ops = &br2684_netdev_ops;
 639
 640         INIT_LIST_HEAD(&brdev->brvccs);
 641 }
 642
 643 static void br2684_setup_routed(struct net_device *netdev)
 644 {
 645         struct br2684_dev *brdev = BRPRIV(netdev);
 646
 647         brdev->net_dev = netdev;
 648         netdev->hard_header_len = sizeof(llc_oui_ipv4); /* worst case */
 649         netdev->netdev_ops = &br2684_netdev_ops_routed;
 650         netdev->addr_len = 0;
 651         netdev->mtu = ETH_DATA_LEN;
 652         netdev->min_mtu = 0;
 653         netdev->max_mtu = ETH_MAX_MTU;
 654         netdev->type = ARPHRD_PPP;
 655         netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 656         netdev->tx_queue_len = 100;
 657         INIT_LIST_HEAD(&brdev->brvccs);
 658 }
 659
 660 static int br2684_create(void __user *arg)
 661 {
 662         int err;
 663         struct net_device *netdev;
 664         struct br2684_dev *brdev;
 665         struct atm_newif_br2684 ni;
 666         enum br2684_payload payload;
 667
 668         pr_debug("\n");
 669
 670         if (copy_from_user(&ni, arg, sizeof ni))
 671                 return -EFAULT;
 672
 673         if (ni.media & BR2684_FLAG_ROUTED)
 674                 payload = p_routed;
 675         else
 676                 payload = p_bridged;
 677         ni.media &= 0xffff;     /* strip flags */
 678
 679         if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500)
 680                 return -EINVAL;
 681
 682         netdev = alloc_netdev(sizeof(struct br2684_dev),
 683                               ni.ifname[0] ? ni.ifname : "nas%d",
 684                               NET_NAME_UNKNOWN,
 685                               (payload == p_routed) ? br2684_setup_routed : br2684_setup);
 686         if (!netdev)
 687                 return -ENOMEM;
 688
 689         brdev = BRPRIV(netdev);
 690
 691         pr_debug("registered netdev %s\n", netdev->name);
 692         /* open, stop, do_ioctl ? */
 693         err = register_netdev(netdev);
 694         if (err < 0) {
 695                 pr_err("register_netdev failed\n");
 696                 free_netdev(netdev);
 697                 return err;
 698         }
 699
 700         write_lock_irq(&devs_lock);
 701
 702         brdev->payload = payload;
 703
 704         if (list_empty(&br2684_devs)) {
 705                 /* 1st br2684 device */
 706                 brdev->number = 1;
 707         } else
 708                 brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
 709
 710         list_add_tail(&brdev->br2684_devs, &br2684_devs);
 711         write_unlock_irq(&devs_lock);
 712         return 0;
 713 }
 714
 715 /*
 716  * This handles ioctls actually performed on our vcc - we must return
 717  * -ENOIOCTLCMD for any unrecognized ioctl
 718  */
 719 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
 720                         unsigned long arg)
 721 {
 722         struct atm_vcc *atmvcc = ATM_SD(sock);
 723         void __user *argp = (void __user *)arg;
 724         atm_backend_t b;
 725
 726         int err;
 727         switch (cmd) {
 728         case ATM_SETBACKEND:
 729         case ATM_NEWBACKENDIF:
 730                 err = get_user(b, (atm_backend_t __user *) argp);
 731                 if (err)
 732                         return -EFAULT;
 733                 if (b != ATM_BACKEND_BR2684)
 734                         return -ENOIOCTLCMD;
 735                 if (!capable(CAP_NET_ADMIN))
 736                         return -EPERM;
 737                 if (cmd == ATM_SETBACKEND) {
 738                         if (sock->state != SS_CONNECTED)
 739                                 return -EINVAL;
 740                         return br2684_regvcc(atmvcc, argp);
 741                 } else {
 742                         return br2684_create(argp);
 743                 }
 744 #ifdef CONFIG_ATM_BR2684_IPFILTER
 745         case BR2684_SETFILT:
 746                 if (atmvcc->push != br2684_push)
 747                         return -ENOIOCTLCMD;
 748                 if (!capable(CAP_NET_ADMIN))
 749                         return -EPERM;
 750                 err = br2684_setfilt(atmvcc, argp);
 751
 752                 return err;
 753 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 754         }
 755         return -ENOIOCTLCMD;
 756 }
 757
 758 static struct atm_ioctl br2684_ioctl_ops = {
 759         .owner = THIS_MODULE,
 760         .ioctl = br2684_ioctl,
 761 };
 762
 763 #ifdef CONFIG_PROC_FS
 764 static void *br2684_seq_start(struct seq_file *seq, loff_t * pos)
 765         __acquires(devs_lock)
 766 {
 767         read_lock(&devs_lock);
 768         return seq_list_start(&br2684_devs, *pos);
 769 }
 770
 771 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t * pos)
 772 {
 773         return seq_list_next(v, &br2684_devs, pos);
 774 }
 775
 776 static void br2684_seq_stop(struct seq_file *seq, void *v)
 777         __releases(devs_lock)
 778 {
 779         read_unlock(&devs_lock);
 780 }
 781
 782 static int br2684_seq_show(struct seq_file *seq, void *v)
 783 {
 784         const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
 785                                                     br2684_devs);
 786         const struct net_device *net_dev = brdev->net_dev;
 787         const struct br2684_vcc *brvcc;
 788
 789         seq_printf(seq, "dev %.16s: num=%d, mac=%pM (%s)\n",
 790                    net_dev->name,
 791                    brdev->number,
 792                    net_dev->dev_addr,
 793                    brdev->mac_was_set ? "set" : "auto");
 794
 795         list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
 796                 seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
 797                            ", failed copies %u/%u"
 798                            "\n", brvcc->atmvcc->dev->number,
 799                            brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
 800                            (brvcc->encaps == e_llc) ? "LLC" : "VC",
 801                            (brdev->payload == p_bridged) ? "bridged" : "routed",
 802                            brvcc->copies_failed, brvcc->copies_needed);
 803 #ifdef CONFIG_ATM_BR2684_IPFILTER
 804                 if (brvcc->filter.netmask != 0)
 805                         seq_printf(seq, "    filter=%pI4/%pI4\n",
 806                                    &brvcc->filter.prefix,
 807                                    &brvcc->filter.netmask);
 808 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 809         }
 810         return 0;
 811 }
 812
 813 static const struct seq_operations br2684_seq_ops = {
 814         .start = br2684_seq_start,
 815         .next = br2684_seq_next,
 816         .stop = br2684_seq_stop,
 817         .show = br2684_seq_show,
 818 };
 819
 820 extern struct proc_dir_entry *atm_proc_root;    /* from proc.c */
 821 #endif /* CONFIG_PROC_FS */
 822
 823 static int __init br2684_init(void)
 824 {
 825 #ifdef CONFIG_PROC_FS
 826         struct proc_dir_entry *p;
 827         p = proc_create_seq("br2684", 0, atm_proc_root, &br2684_seq_ops);
 828         if (p == NULL)
 829                 return -ENOMEM;
 830 #endif
 831         register_atm_ioctl(&br2684_ioctl_ops);
 832         register_atmdevice_notifier(&atm_dev_notifier);
 833         return 0;
 834 }
 835
 836 static void __exit br2684_exit(void)
 837 {
 838         struct net_device *net_dev;
 839         struct br2684_dev *brdev;
 840         struct br2684_vcc *brvcc;
 841         deregister_atm_ioctl(&br2684_ioctl_ops);
 842
 843 #ifdef CONFIG_PROC_FS
 844         remove_proc_entry("br2684", atm_proc_root);
 845 #endif
 846
 847
 848         unregister_atmdevice_notifier(&atm_dev_notifier);
 849
 850         while (!list_empty(&br2684_devs)) {
 851                 net_dev = list_entry_brdev(br2684_devs.next);
 852                 brdev = BRPRIV(net_dev);
 853                 while (!list_empty(&brdev->brvccs)) {
 854                         brvcc = list_entry_brvcc(brdev->brvccs.next);
 855                         br2684_close_vcc(brvcc);
 856                 }
 857
 858                 list_del(&brdev->br2684_devs);
 859                 unregister_netdev(net_dev);
 860                 free_netdev(net_dev);
 861         }
 862 }
 863
 864 module_init(br2684_init);
 865 module_exit(br2684_exit);
 866
 867 MODULE_AUTHOR("Marcell GAL");
 868 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
 869 MODULE_LICENSE("GPL");