net/atm/br2684.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Ethernet netdevice using ATM AAL5 as underlying carrier
   4  * (RFC1483 obsoleted by RFC2684) for Linux
   5  *
   6  * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
   7  *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/list.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/rtnetlink.h>
  20 #include <linux/ip.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/slab.h>
  23 #include <net/arp.h>
  24 #include <linux/atm.h>
  25 #include <linux/atmdev.h>
  26 #include <linux/capability.h>
  27 #include <linux/seq_file.h>
  28
  29 #include <linux/atmbr2684.h>
  30
  31 #include "common.h"
  32
  33 static void skb_debug(const struct sk_buff *skb)
  34 {
  35 #ifdef SKB_DEBUG
  36 #define NUM2PRINT 50
  37         print_hex_dump(KERN_DEBUG, "br2684: skb: ", DUMP_OFFSET,
  38                        16, 1, skb->data, min(NUM2PRINT, skb->len), true);
  39 #endif
  40 }
  41
  42 #define BR2684_ETHERTYPE_LEN    2
  43 #define BR2684_PAD_LEN          2
  44
  45 #define LLC             0xaa, 0xaa, 0x03
  46 #define SNAP_BRIDGED    0x00, 0x80, 0xc2
  47 #define SNAP_ROUTED     0x00, 0x00, 0x00
  48 #define PID_ETHERNET    0x00, 0x07
  49 #define ETHERTYPE_IPV4  0x08, 0x00
  50 #define ETHERTYPE_IPV6  0x86, 0xdd
  51 #define PAD_BRIDGED     0x00, 0x00
  52
  53 static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
  54 static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
  55 static const unsigned char llc_oui_pid_pad[] =
  56                         { LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
  57 static const unsigned char pad[] = { PAD_BRIDGED };
  58 static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
  59 static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
  60
  61 enum br2684_encaps {
  62         e_vc = BR2684_ENCAPS_VC,
  63         e_llc = BR2684_ENCAPS_LLC,
  64 };
  65
  66 struct br2684_vcc {
  67         struct atm_vcc *atmvcc;
  68         struct net_device *device;
  69         /* keep old push, pop functions for chaining */
  70         void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
  71         void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
  72         void (*old_release_cb)(struct atm_vcc *vcc);
  73         struct module *old_owner;
  74         enum br2684_encaps encaps;
  75         struct list_head brvccs;
  76 #ifdef CONFIG_ATM_BR2684_IPFILTER
  77         struct br2684_filter filter;
  78 #endif /* CONFIG_ATM_BR2684_IPFILTER */
  79         unsigned int copies_needed, copies_failed;
  80         atomic_t qspace;
  81 };
  82
  83 struct br2684_dev {
  84         struct net_device *net_dev;
  85         struct list_head br2684_devs;
  86         int number;
  87         struct list_head brvccs;        /* one device <=> one vcc (before xmas) */
  88         int mac_was_set;
  89         enum br2684_payload payload;
  90 };
  91
  92 /*
  93  * This lock should be held for writing any time the list of devices or
  94  * their attached vcc's could be altered.  It should be held for reading
  95  * any time these are being queried.  Note that we sometimes need to
  96  * do read-locking under interrupting context, so write locking must block
  97  * the current CPU's interrupts.
  98  */
  99 static DEFINE_RWLOCK(devs_lock);
 100
 101 static LIST_HEAD(br2684_devs);
 102
 103 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
 104 {
 105         return netdev_priv(net_dev);
 106 }
 107
 108 static inline struct net_device *list_entry_brdev(const struct list_head *le)
 109 {
 110         return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
 111 }
 112
 113 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
 114 {
 115         return (struct br2684_vcc *)(atmvcc->user_back);
 116 }
 117
 118 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
 119 {
 120         return list_entry(le, struct br2684_vcc, brvccs);
 121 }
 122
 123 /* Caller should hold read_lock(&devs_lock) */
 124 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
 125 {
 126         struct list_head *lh;
 127         struct net_device *net_dev;
 128         switch (s->method) {
 129         case BR2684_FIND_BYNUM:
 130                 list_for_each(lh, &br2684_devs) {
 131                         net_dev = list_entry_brdev(lh);
 132                         if (BRPRIV(net_dev)->number == s->spec.devnum)
 133                                 return net_dev;
 134                 }
 135                 break;
 136         case BR2684_FIND_BYIFNAME:
 137                 list_for_each(lh, &br2684_devs) {
 138                         net_dev = list_entry_brdev(lh);
 139                         if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
 140                                 return net_dev;
 141                 }
 142                 break;
 143         }
 144         return NULL;
 145 }
 146
 147 static int atm_dev_event(struct notifier_block *this, unsigned long event,
 148                  void *arg)
 149 {
 150         struct atm_dev *atm_dev = arg;
 151         struct list_head *lh;
 152         struct net_device *net_dev;
 153         struct br2684_vcc *brvcc;
 154         struct atm_vcc *atm_vcc;
 155         unsigned long flags;
 156
 157         pr_debug("event=%ld dev=%p\n", event, atm_dev);
 158
 159         read_lock_irqsave(&devs_lock, flags);
 160         list_for_each(lh, &br2684_devs) {
 161                 net_dev = list_entry_brdev(lh);
 162
 163                 list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
 164                         atm_vcc = brvcc->atmvcc;
 165                         if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
 166
 167                                 if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
 168                                         netif_carrier_off(net_dev);
 169                                 else
 170                                         netif_carrier_on(net_dev);
 171
 172                         }
 173                 }
 174         }
 175         read_unlock_irqrestore(&devs_lock, flags);
 176
 177         return NOTIFY_DONE;
 178 }
 179
 180 static struct notifier_block atm_dev_notifier = {
 181         .notifier_call = atm_dev_event,
 182 };
 183
 184 /* chained vcc->pop function.  Check if we should wake the netif_queue */
 185 static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 186 {
 187         struct br2684_vcc *brvcc = BR2684_VCC(vcc);
 188
 189         pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
 190         brvcc->old_pop(vcc, skb);
 191
 192         /* If the queue space just went up from zero, wake */
 193         if (atomic_inc_return(&brvcc->qspace) == 1)
 194                 netif_wake_queue(brvcc->device);
 195 }
 196
 197 /*
 198  * Send a packet out a particular vcc.  Not to useful right now, but paves
 199  * the way for multiple vcc's per itf.  Returns true if we can send,
 200  * otherwise false
 201  */
 202 static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
 203                            struct br2684_vcc *brvcc)
 204 {
 205         struct br2684_dev *brdev = BRPRIV(dev);
 206         struct atm_vcc *atmvcc;
 207         int minheadroom = (brvcc->encaps == e_llc) ?
 208                 ((brdev->payload == p_bridged) ?
 209                         sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) :
 210                 ((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0);
 211
 212         if (skb_headroom(skb) < minheadroom) {
 213                 struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
 214                 brvcc->copies_needed++;
 215                 dev_kfree_skb(skb);
 216                 if (skb2 == NULL) {
 217                         brvcc->copies_failed++;
 218                         return 0;
 219                 }
 220                 skb = skb2;
 221         }
 222
 223         if (brvcc->encaps == e_llc) {
 224                 if (brdev->payload == p_bridged) {
 225                         skb_push(skb, sizeof(llc_oui_pid_pad));
 226                         skb_copy_to_linear_data(skb, llc_oui_pid_pad,
 227                                                 sizeof(llc_oui_pid_pad));
 228                 } else if (brdev->payload == p_routed) {
 229                         unsigned short prot = ntohs(skb->protocol);
 230
 231                         skb_push(skb, sizeof(llc_oui_ipv4));
 232                         switch (prot) {
 233                         case ETH_P_IP:
 234                                 skb_copy_to_linear_data(skb, llc_oui_ipv4,
 235                                                         sizeof(llc_oui_ipv4));
 236                                 break;
 237                         case ETH_P_IPV6:
 238                                 skb_copy_to_linear_data(skb, llc_oui_ipv6,
 239                                                         sizeof(llc_oui_ipv6));
 240                                 break;
 241                         default:
 242                                 dev_kfree_skb(skb);
 243                                 return 0;
 244                         }
 245                 }
 246         } else { /* e_vc */
 247                 if (brdev->payload == p_bridged) {
 248                         skb_push(skb, 2);
 249                         memset(skb->data, 0, 2);
 250                 }
 251         }
 252         skb_debug(skb);
 253
 254         ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
 255         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
 256         atm_account_tx(atmvcc, skb);
 257         dev->stats.tx_packets++;
 258         dev->stats.tx_bytes += skb->len;
 259
 260         if (atomic_dec_return(&brvcc->qspace) < 1) {
 261                 /* No more please! */
 262                 netif_stop_queue(brvcc->device);
 263                 /* We might have raced with br2684_pop() */
 264                 if (unlikely(atomic_read(&brvcc->qspace) > 0))
 265                         netif_wake_queue(brvcc->device);
 266         }
 267
 268         /* If this fails immediately, the skb will be freed and br2684_pop()
 269            will wake the queue if appropriate. Just return an error so that
 270            the stats are updated correctly */
 271         return !atmvcc->send(atmvcc, skb);
 272 }
 273
 274 static void br2684_release_cb(struct atm_vcc *atmvcc)
 275 {
 276         struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
 277
 278         if (atomic_read(&brvcc->qspace) > 0)
 279                 netif_wake_queue(brvcc->device);
 280
 281         if (brvcc->old_release_cb)
 282                 brvcc->old_release_cb(atmvcc);
 283 }
 284
 285 static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
 286                                                    const struct br2684_dev *brdev)
 287 {
 288         return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);        /* 1 vcc/dev right now */
 289 }
 290
 291 static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
 292                                      struct net_device *dev)
 293 {
 294         struct br2684_dev *brdev = BRPRIV(dev);
 295         struct br2684_vcc *brvcc;
 296         struct atm_vcc *atmvcc;
 297         netdev_tx_t ret = NETDEV_TX_OK;
 298
 299         pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
 300         read_lock(&devs_lock);
 301         brvcc = pick_outgoing_vcc(skb, brdev);
 302         if (brvcc == NULL) {
 303                 pr_debug("no vcc attached to dev %s\n", dev->name);
 304                 dev->stats.tx_errors++;
 305                 dev->stats.tx_carrier_errors++;
 306                 /* netif_stop_queue(dev); */
 307                 dev_kfree_skb(skb);
 308                 goto out_devs;
 309         }
 310         atmvcc = brvcc->atmvcc;
 311
 312         bh_lock_sock(sk_atm(atmvcc));
 313
 314         if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
 315             test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
 316             !test_bit(ATM_VF_READY, &atmvcc->flags)) {
 317                 dev->stats.tx_dropped++;
 318                 dev_kfree_skb(skb);
 319                 goto out;
 320         }
 321
 322         if (sock_owned_by_user(sk_atm(atmvcc))) {
 323                 netif_stop_queue(brvcc->device);
 324                 ret = NETDEV_TX_BUSY;
 325                 goto out;
 326         }
 327
 328         if (!br2684_xmit_vcc(skb, dev, brvcc)) {
 329                 /*
 330                  * We should probably use netif_*_queue() here, but that
 331                  * involves added complication.  We need to walk before
 332                  * we can run.
 333                  *
 334                  * Don't free here! this pointer might be no longer valid!
 335                  */
 336                 dev->stats.tx_errors++;
 337                 dev->stats.tx_fifo_errors++;
 338         }
 339  out:
 340         bh_unlock_sock(sk_atm(atmvcc));
 341  out_devs:
 342         read_unlock(&devs_lock);
 343         return ret;
 344 }
 345
 346 /*
 347  * We remember when the MAC gets set, so we don't override it later with
 348  * the ESI of the ATM card of the first VC
 349  */
 350 static int br2684_mac_addr(struct net_device *dev, void *p)
 351 {
 352         int err = eth_mac_addr(dev, p);
 353         if (!err)
 354                 BRPRIV(dev)->mac_was_set = 1;
 355         return err;
 356 }
 357
 358 #ifdef CONFIG_ATM_BR2684_IPFILTER
 359 /* this IOCTL is experimental. */
 360 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
 361 {
 362         struct br2684_vcc *brvcc;
 363         struct br2684_filter_set fs;
 364
 365         if (copy_from_user(&fs, arg, sizeof fs))
 366                 return -EFAULT;
 367         if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
 368                 /*
 369                  * This is really a per-vcc thing, but we can also search
 370                  * by device.
 371                  */
 372                 struct br2684_dev *brdev;
 373                 read_lock(&devs_lock);
 374                 brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
 375                 if (brdev == NULL || list_empty(&brdev->brvccs) ||
 376                     brdev->brvccs.next != brdev->brvccs.prev)   /* >1 VCC */
 377                         brvcc = NULL;
 378                 else
 379                         brvcc = list_entry_brvcc(brdev->brvccs.next);
 380                 read_unlock(&devs_lock);
 381                 if (brvcc == NULL)
 382                         return -ESRCH;
 383         } else
 384                 brvcc = BR2684_VCC(atmvcc);
 385         memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
 386         return 0;
 387 }
 388
 389 /* Returns 1 if packet should be dropped */
 390 static inline int
 391 packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
 392 {
 393         if (brvcc->filter.netmask == 0)
 394                 return 0;       /* no filter in place */
 395         if (type == htons(ETH_P_IP) &&
 396             (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
 397              netmask) == brvcc->filter.prefix)
 398                 return 0;
 399         if (type == htons(ETH_P_ARP))
 400                 return 0;
 401         /*
 402          * TODO: we should probably filter ARPs too.. don't want to have
 403          * them returning values that don't make sense, or is that ok?
 404          */
 405         return 1;               /* drop */
 406 }
 407 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 408
 409 static void br2684_close_vcc(struct br2684_vcc *brvcc)
 410 {
 411         pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
 412         write_lock_irq(&devs_lock);
 413         list_del(&brvcc->brvccs);
 414         write_unlock_irq(&devs_lock);
 415         brvcc->atmvcc->user_back = NULL;        /* what about vcc->recvq ??? */
 416         brvcc->atmvcc->release_cb = brvcc->old_release_cb;
 417         brvcc->old_push(brvcc->atmvcc, NULL);   /* pass on the bad news */
 418         module_put(brvcc->old_owner);
 419         kfree(brvcc);
 420 }
 421
 422 /* when AAL5 PDU comes in: */
 423 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
 424 {
 425         struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
 426         struct net_device *net_dev = brvcc->device;
 427         struct br2684_dev *brdev = BRPRIV(net_dev);
 428
 429         pr_debug("\n");
 430
 431         if (unlikely(skb == NULL)) {
 432                 /* skb==NULL means VCC is being destroyed */
 433                 br2684_close_vcc(brvcc);
 434                 if (list_empty(&brdev->brvccs)) {
 435                         write_lock_irq(&devs_lock);
 436                         list_del(&brdev->br2684_devs);
 437                         write_unlock_irq(&devs_lock);
 438                         unregister_netdev(net_dev);
 439                         free_netdev(net_dev);
 440                 }
 441                 return;
 442         }
 443
 444         skb_debug(skb);
 445         atm_return(atmvcc, skb->truesize);
 446         pr_debug("skb from brdev %p\n", brdev);
 447         if (brvcc->encaps == e_llc) {
 448
 449                 if (skb->len > 7 && skb->data[7] == 0x01)
 450                         __skb_trim(skb, skb->len - 4);
 451
 452                 /* accept packets that have "ipv[46]" in the snap header */
 453                 if ((skb->len >= (sizeof(llc_oui_ipv4))) &&
 454                     (memcmp(skb->data, llc_oui_ipv4,
 455                             sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
 456                         if (memcmp(skb->data + 6, ethertype_ipv6,
 457                                    sizeof(ethertype_ipv6)) == 0)
 458                                 skb->protocol = htons(ETH_P_IPV6);
 459                         else if (memcmp(skb->data + 6, ethertype_ipv4,
 460                                         sizeof(ethertype_ipv4)) == 0)
 461                                 skb->protocol = htons(ETH_P_IP);
 462                         else
 463                                 goto error;
 464                         skb_pull(skb, sizeof(llc_oui_ipv4));
 465                         skb_reset_network_header(skb);
 466                         skb->pkt_type = PACKET_HOST;
 467                 /*
 468                  * Let us waste some time for checking the encapsulation.
 469                  * Note, that only 7 char is checked so frames with a valid FCS
 470                  * are also accepted (but FCS is not checked of course).
 471                  */
 472                 } else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
 473                            (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
 474                         skb_pull(skb, sizeof(llc_oui_pid_pad));
 475                         skb->protocol = eth_type_trans(skb, net_dev);
 476                 } else
 477                         goto error;
 478
 479         } else { /* e_vc */
 480                 if (brdev->payload == p_routed) {
 481                         struct iphdr *iph;
 482
 483                         skb_reset_network_header(skb);
 484                         iph = ip_hdr(skb);
 485                         if (iph->version == 4)
 486                                 skb->protocol = htons(ETH_P_IP);
 487                         else if (iph->version == 6)
 488                                 skb->protocol = htons(ETH_P_IPV6);
 489                         else
 490                                 goto error;
 491                         skb->pkt_type = PACKET_HOST;
 492                 } else { /* p_bridged */
 493                         /* first 2 chars should be 0 */
 494                         if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0)
 495                                 goto error;
 496                         skb_pull(skb, BR2684_PAD_LEN);
 497                         skb->protocol = eth_type_trans(skb, net_dev);
 498                 }
 499         }
 500
 501 #ifdef CONFIG_ATM_BR2684_IPFILTER
 502         if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
 503                 goto dropped;
 504 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 505         skb->dev = net_dev;
 506         ATM_SKB(skb)->vcc = atmvcc;     /* needed ? */
 507         pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
 508         skb_debug(skb);
 509         /* sigh, interface is down? */
 510         if (unlikely(!(net_dev->flags & IFF_UP)))
 511                 goto dropped;
 512         net_dev->stats.rx_packets++;
 513         net_dev->stats.rx_bytes += skb->len;
 514         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 515         netif_rx(skb);
 516         return;
 517
 518 dropped:
 519         net_dev->stats.rx_dropped++;
 520         goto free_skb;
 521 error:
 522         net_dev->stats.rx_errors++;
 523 free_skb:
 524         dev_kfree_skb(skb);
 525 }
 526
 527 /*
 528  * Assign a vcc to a dev
 529  * Note: we do not have explicit unassign, but look at _push()
 530  */
 531 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 532 {
 533         struct br2684_vcc *brvcc;
 534         struct br2684_dev *brdev;
 535         struct net_device *net_dev;
 536         struct atm_backend_br2684 be;
 537         int err;
 538
 539         if (copy_from_user(&be, arg, sizeof be))
 540                 return -EFAULT;
 541         brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
 542         if (!brvcc)
 543                 return -ENOMEM;
 544         /*
 545          * Allow two packets in the ATM queue. One actually being sent, and one
 546          * for the ATM 'TX done' handler to send. It shouldn't take long to get
 547          * the next one from the netdev queue, when we need it. More than that
 548          * would be bufferbloat.
 549          */
 550         atomic_set(&brvcc->qspace, 2);
 551         write_lock_irq(&devs_lock);
 552         net_dev = br2684_find_dev(&be.ifspec);
 553         if (net_dev == NULL) {
 554                 pr_err("tried to attach to non-existent device\n");
 555                 err = -ENXIO;
 556                 goto error;
 557         }
 558         brdev = BRPRIV(net_dev);
 559         if (atmvcc->push == NULL) {
 560                 err = -EBADFD;
 561                 goto error;
 562         }
 563         if (!list_empty(&brdev->brvccs)) {
 564                 /* Only 1 VCC/dev right now */
 565                 err = -EEXIST;
 566                 goto error;
 567         }
 568         if (be.fcs_in != BR2684_FCSIN_NO ||
 569             be.fcs_out != BR2684_FCSOUT_NO ||
 570             be.fcs_auto || be.has_vpiid || be.send_padding ||
 571             (be.encaps != BR2684_ENCAPS_VC &&
 572              be.encaps != BR2684_ENCAPS_LLC) ||
 573             be.min_size != 0) {
 574                 err = -EINVAL;
 575                 goto error;
 576         }
 577         pr_debug("vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps, brvcc);
 578         if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
 579                 unsigned char *esi = atmvcc->dev->esi;
 580                 if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
 581                         memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
 582                 else
 583                         net_dev->dev_addr[2] = 1;
 584         }
 585         list_add(&brvcc->brvccs, &brdev->brvccs);
 586         write_unlock_irq(&devs_lock);
 587         brvcc->device = net_dev;
 588         brvcc->atmvcc = atmvcc;
 589         atmvcc->user_back = brvcc;
 590         brvcc->encaps = (enum br2684_encaps)be.encaps;
 591         brvcc->old_push = atmvcc->push;
 592         brvcc->old_pop = atmvcc->pop;
 593         brvcc->old_release_cb = atmvcc->release_cb;
 594         brvcc->old_owner = atmvcc->owner;
 595         barrier();
 596         atmvcc->push = br2684_push;
 597         atmvcc->pop = br2684_pop;
 598         atmvcc->release_cb = br2684_release_cb;
 599         atmvcc->owner = THIS_MODULE;
 600
 601         /* initialize netdev carrier state */
 602         if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
 603                 netif_carrier_off(net_dev);
 604         else
 605                 netif_carrier_on(net_dev);
 606
 607         __module_get(THIS_MODULE);
 608
 609         /* re-process everything received between connection setup and
 610            backend setup */
 611         vcc_process_recv_queue(atmvcc);
 612         return 0;
 613
 614 error:
 615         write_unlock_irq(&devs_lock);
 616         kfree(brvcc);
 617         return err;
 618 }
 619
 620 static const struct net_device_ops br2684_netdev_ops = {
 621         .ndo_start_xmit         = br2684_start_xmit,
 622         .ndo_set_mac_address    = br2684_mac_addr,
 623         .ndo_validate_addr      = eth_validate_addr,
 624 };
 625
 626 static const struct net_device_ops br2684_netdev_ops_routed = {
 627         .ndo_start_xmit         = br2684_start_xmit,
 628         .ndo_set_mac_address    = br2684_mac_addr,
 629 };
 630
 631 static void br2684_setup(struct net_device *netdev)
 632 {
 633         struct br2684_dev *brdev = BRPRIV(netdev);
 634
 635         ether_setup(netdev);
 636         netdev->hard_header_len += sizeof(llc_oui_pid_pad); /* worst case */
 637         brdev->net_dev = netdev;
 638
 639         netdev->netdev_ops = &br2684_netdev_ops;
 640
 641         INIT_LIST_HEAD(&brdev->brvccs);
 642 }
 643
 644 static void br2684_setup_routed(struct net_device *netdev)
 645 {
 646         struct br2684_dev *brdev = BRPRIV(netdev);
 647
 648         brdev->net_dev = netdev;
 649         netdev->hard_header_len = sizeof(llc_oui_ipv4); /* worst case */
 650         netdev->netdev_ops = &br2684_netdev_ops_routed;
 651         netdev->addr_len = 0;
 652         netdev->mtu = ETH_DATA_LEN;
 653         netdev->min_mtu = 0;
 654         netdev->max_mtu = ETH_MAX_MTU;
 655         netdev->type = ARPHRD_PPP;
 656         netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 657         netdev->tx_queue_len = 100;
 658         INIT_LIST_HEAD(&brdev->brvccs);
 659 }
 660
 661 static int br2684_create(void __user *arg)
 662 {
 663         int err;
 664         struct net_device *netdev;
 665         struct br2684_dev *brdev;
 666         struct atm_newif_br2684 ni;
 667         enum br2684_payload payload;
 668
 669         pr_debug("\n");
 670
 671         if (copy_from_user(&ni, arg, sizeof ni))
 672                 return -EFAULT;
 673
 674         if (ni.media & BR2684_FLAG_ROUTED)
 675                 payload = p_routed;
 676         else
 677                 payload = p_bridged;
 678         ni.media &= 0xffff;     /* strip flags */
 679
 680         if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500)
 681                 return -EINVAL;
 682
 683         netdev = alloc_netdev(sizeof(struct br2684_dev),
 684                               ni.ifname[0] ? ni.ifname : "nas%d",
 685                               NET_NAME_UNKNOWN,
 686                               (payload == p_routed) ? br2684_setup_routed : br2684_setup);
 687         if (!netdev)
 688                 return -ENOMEM;
 689
 690         brdev = BRPRIV(netdev);
 691
 692         pr_debug("registered netdev %s\n", netdev->name);
 693         /* open, stop, do_ioctl ? */
 694         err = register_netdev(netdev);
 695         if (err < 0) {
 696                 pr_err("register_netdev failed\n");
 697                 free_netdev(netdev);
 698                 return err;
 699         }
 700
 701         write_lock_irq(&devs_lock);
 702
 703         brdev->payload = payload;
 704
 705         if (list_empty(&br2684_devs)) {
 706                 /* 1st br2684 device */
 707                 brdev->number = 1;
 708         } else
 709                 brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
 710
 711         list_add_tail(&brdev->br2684_devs, &br2684_devs);
 712         write_unlock_irq(&devs_lock);
 713         return 0;
 714 }
 715
 716 /*
 717  * This handles ioctls actually performed on our vcc - we must return
 718  * -ENOIOCTLCMD for any unrecognized ioctl
 719  */
 720 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
 721                         unsigned long arg)
 722 {
 723         struct atm_vcc *atmvcc = ATM_SD(sock);
 724         void __user *argp = (void __user *)arg;
 725         atm_backend_t b;
 726
 727         int err;
 728         switch (cmd) {
 729         case ATM_SETBACKEND:
 730         case ATM_NEWBACKENDIF:
 731                 err = get_user(b, (atm_backend_t __user *) argp);
 732                 if (err)
 733                         return -EFAULT;
 734                 if (b != ATM_BACKEND_BR2684)
 735                         return -ENOIOCTLCMD;
 736                 if (!capable(CAP_NET_ADMIN))
 737                         return -EPERM;
 738                 if (cmd == ATM_SETBACKEND) {
 739                         if (sock->state != SS_CONNECTED)
 740                                 return -EINVAL;
 741                         return br2684_regvcc(atmvcc, argp);
 742                 } else {
 743                         return br2684_create(argp);
 744                 }
 745 #ifdef CONFIG_ATM_BR2684_IPFILTER
 746         case BR2684_SETFILT:
 747                 if (atmvcc->push != br2684_push)
 748                         return -ENOIOCTLCMD;
 749                 if (!capable(CAP_NET_ADMIN))
 750                         return -EPERM;
 751                 err = br2684_setfilt(atmvcc, argp);
 752
 753                 return err;
 754 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 755         }
 756         return -ENOIOCTLCMD;
 757 }
 758
 759 static struct atm_ioctl br2684_ioctl_ops = {
 760         .owner = THIS_MODULE,
 761         .ioctl = br2684_ioctl,
 762 };
 763
 764 #ifdef CONFIG_PROC_FS
 765 static void *br2684_seq_start(struct seq_file *seq, loff_t * pos)
 766         __acquires(devs_lock)
 767 {
 768         read_lock(&devs_lock);
 769         return seq_list_start(&br2684_devs, *pos);
 770 }
 771
 772 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t * pos)
 773 {
 774         return seq_list_next(v, &br2684_devs, pos);
 775 }
 776
 777 static void br2684_seq_stop(struct seq_file *seq, void *v)
 778         __releases(devs_lock)
 779 {
 780         read_unlock(&devs_lock);
 781 }
 782
 783 static int br2684_seq_show(struct seq_file *seq, void *v)
 784 {
 785         const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
 786                                                     br2684_devs);
 787         const struct net_device *net_dev = brdev->net_dev;
 788         const struct br2684_vcc *brvcc;
 789
 790         seq_printf(seq, "dev %.16s: num=%d, mac=%pM (%s)\n",
 791                    net_dev->name,
 792                    brdev->number,
 793                    net_dev->dev_addr,
 794                    brdev->mac_was_set ? "set" : "auto");
 795
 796         list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
 797                 seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
 798                            ", failed copies %u/%u"
 799                            "\n", brvcc->atmvcc->dev->number,
 800                            brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
 801                            (brvcc->encaps == e_llc) ? "LLC" : "VC",
 802                            (brdev->payload == p_bridged) ? "bridged" : "routed",
 803                            brvcc->copies_failed, brvcc->copies_needed);
 804 #ifdef CONFIG_ATM_BR2684_IPFILTER
 805                 if (brvcc->filter.netmask != 0)
 806                         seq_printf(seq, "    filter=%pI4/%pI4\n",
 807                                    &brvcc->filter.prefix,
 808                                    &brvcc->filter.netmask);
 809 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 810         }
 811         return 0;
 812 }
 813
 814 static const struct seq_operations br2684_seq_ops = {
 815         .start = br2684_seq_start,
 816         .next = br2684_seq_next,
 817         .stop = br2684_seq_stop,
 818         .show = br2684_seq_show,
 819 };
 820
 821 extern struct proc_dir_entry *atm_proc_root;    /* from proc.c */
 822 #endif /* CONFIG_PROC_FS */
 823
 824 static int __init br2684_init(void)
 825 {
 826 #ifdef CONFIG_PROC_FS
 827         struct proc_dir_entry *p;
 828         p = proc_create_seq("br2684", 0, atm_proc_root, &br2684_seq_ops);
 829         if (p == NULL)
 830                 return -ENOMEM;
 831 #endif
 832         register_atm_ioctl(&br2684_ioctl_ops);
 833         register_atmdevice_notifier(&atm_dev_notifier);
 834         return 0;
 835 }
 836
 837 static void __exit br2684_exit(void)
 838 {
 839         struct net_device *net_dev;
 840         struct br2684_dev *brdev;
 841         struct br2684_vcc *brvcc;
 842         deregister_atm_ioctl(&br2684_ioctl_ops);
 843
 844 #ifdef CONFIG_PROC_FS
 845         remove_proc_entry("br2684", atm_proc_root);
 846 #endif
 847
 848
 849         unregister_atmdevice_notifier(&atm_dev_notifier);
 850
 851         while (!list_empty(&br2684_devs)) {
 852                 net_dev = list_entry_brdev(br2684_devs.next);
 853                 brdev = BRPRIV(net_dev);
 854                 while (!list_empty(&brdev->brvccs)) {
 855                         brvcc = list_entry_brvcc(brdev->brvccs.next);
 856                         br2684_close_vcc(brvcc);
 857                 }
 858
 859                 list_del(&brdev->br2684_devs);
 860                 unregister_netdev(net_dev);
 861                 free_netdev(net_dev);
 862         }
 863 }
 864
 865 module_init(br2684_init);
 866 module_exit(br2684_exit);
 867
 868 MODULE_AUTHOR("Marcell GAL");
 869 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
 870 MODULE_LICENSE("GPL");