kernel/linux/net/atm/br2684.c

   1 /*
   2 Experimental ethernet netdevice using ATM AAL5 as underlying carrier
   3 (RFC1483 obsoleted by RFC2684) for Linux 2.4
   4 Author: Marcell GAL, 2000, XDSL Ltd, Hungary
   5 */
   6
   7 #include <linux/module.h>
   8 #include <linux/config.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/list.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/rtnetlink.h>
  16 #include <linux/ip.h>
  17 #include <asm/uaccess.h>
  18 #include <net/arp.h>
  19 #include <linux/atm.h>
  20 #include <linux/atmdev.h>
  21 #include <linux/seq_file.h>
  22
  23 #include <linux/atmbr2684.h>
  24
  25 #include "common.h"
  26 #include "ipcommon.h"
  27
  28 /*
  29  * Define this to use a version of the code which interacts with the higher
  30  * layers in a more intellegent way, by always reserving enough space for
  31  * our header at the begining of the packet.  However, there may still be
  32  * some problems with programs like tcpdump.  In 2.5 we'll sort out what
  33  * we need to do to get this perfect.  For now we just will copy the packet
  34  * if we need space for the header
  35  */
  36 /* #define FASTER_VERSION */
  37
  38 #ifdef DEBUG
  39 #define DPRINTK(format, args...) printk(KERN_DEBUG "br2684: " format, ##args)
  40 #else
  41 #define DPRINTK(format, args...)
  42 #endif
  43
  44 #ifdef SKB_DEBUG
  45 static void skb_debug(const struct sk_buff *skb)
  46 {
  47 #define NUM2PRINT 50
  48         char buf[NUM2PRINT * 3 + 1];    /* 3 chars per byte */
  49         int i = 0;
  50         for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
  51                 sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
  52         }
  53         printk(KERN_DEBUG "br2684: skb: %s\n", buf);
  54 }
  55 #else
  56 #define skb_debug(skb)  do {} while (0)
  57 #endif
  58
  59 static unsigned char llc_oui_pid_pad[] =
  60     { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
  61 #define PADLEN  (2)
  62
  63 enum br2684_encaps {
  64         e_vc  = BR2684_ENCAPS_VC,
  65         e_llc = BR2684_ENCAPS_LLC,
  66 };
  67
  68 struct br2684_vcc {
  69         struct atm_vcc  *atmvcc;
  70         struct net_device *device;
  71         /* keep old push,pop functions for chaining */
  72         void (*old_push)(struct atm_vcc *vcc,struct sk_buff *skb);
  73         /* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
  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 #ifndef FASTER_VERSION
  80         unsigned copies_needed, copies_failed;
  81 #endif /* FASTER_VERSION */
  82 #if defined(CONFIG_MIPS_BRCM)
  83         /* Protocol filter flag, currently only PPPoE.
  84            When turned on, all non-PPPoE traffic will be dropped
  85            on this PVC */
  86         int proto_filter;
  87 #endif
  88 };
  89
  90 struct br2684_dev {
  91         struct net_device *net_dev;
  92         struct list_head br2684_devs;
  93         int number;
  94         struct list_head brvccs; /* one device <=> one vcc (before xmas) */
  95         struct net_device_stats stats;
  96         int mac_was_set;
  97 };
  98
  99 #if defined(CONFIG_MIPS_BRCM)
 100 #define MIN_PKT_SIZE 70
 101 #endif
 102
 103 /*
 104  * This lock should be held for writing any time the list of devices or
 105  * their attached vcc's could be altered.  It should be held for reading
 106  * any time these are being queried.  Note that we sometimes need to
 107  * do read-locking under interrupt context, so write locking must block
 108  * the current CPU's interrupts
 109  */
 110 static rwlock_t devs_lock = RW_LOCK_UNLOCKED;
 111
 112 static LIST_HEAD(br2684_devs);
 113
 114 static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
 115 {
 116         return (struct br2684_dev *) net_dev->priv;
 117 }
 118
 119 static inline struct net_device *list_entry_brdev(const struct list_head *le)
 120 {
 121         return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
 122 }
 123
 124 static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
 125 {
 126         return (struct br2684_vcc *) (atmvcc->user_back);
 127 }
 128
 129 static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
 130 {
 131         return list_entry(le, struct br2684_vcc, brvccs);
 132 }
 133
 134 /* Caller should hold read_lock(&devs_lock) */
 135 static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
 136 {
 137         struct list_head *lh;
 138         struct net_device *net_dev;
 139         switch (s->method) {
 140         case BR2684_FIND_BYNUM:
 141                 list_for_each(lh, &br2684_devs) {
 142                         net_dev = list_entry_brdev(lh);
 143                         if (BRPRIV(net_dev)->number == s->spec.devnum)
 144                                 return net_dev;
 145                 }
 146                 break;
 147         case BR2684_FIND_BYIFNAME:
 148                 list_for_each(lh, &br2684_devs) {
 149                         net_dev = list_entry_brdev(lh);
 150                         if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
 151                                 return net_dev;
 152                 }
 153                 break;
 154         }
 155         return NULL;
 156 }
 157
 158 /*
 159  * Send a packet out a particular vcc.  Not to useful right now, but paves
 160  * the way for multiple vcc's per itf.  Returns true if we can send,
 161  * otherwise false
 162  */
 163 static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
 164         struct br2684_vcc *brvcc)
 165 {
 166         struct atm_vcc *atmvcc;
 167 #ifdef FASTER_VERSION
 168         if (brvcc->encaps == e_llc)
 169                 memcpy(skb_push(skb, 8), llc_oui_pid_pad, 8);
 170         /* last 2 bytes of llc_oui_pid_pad are managed by header routines;
 171            yes, you got it: 8 + 2 = sizeof(llc_oui_pid_pad)
 172          */
 173 #else
 174         int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
 175         if (skb_headroom(skb) < minheadroom) {
 176                 struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
 177                 brvcc->copies_needed++;
 178                 dev_kfree_skb(skb);
 179                 if (skb2 == NULL) {
 180                         brvcc->copies_failed++;
 181                         return 0;
 182                 }
 183                 skb = skb2;
 184         }
 185         skb_push(skb, minheadroom);
 186         if (brvcc->encaps == e_llc)
 187                 memcpy(skb->data, llc_oui_pid_pad, 10);
 188         else
 189                 memset(skb->data, 0, 2);
 190 #endif /* FASTER_VERSION */
 191
 192 #if defined(CONFIG_MIPS_BRCM)
 193         if (skb->len < MIN_PKT_SIZE)
 194         {
 195                 struct sk_buff *skb2=skb_copy_expand(skb, 0, MIN_PKT_SIZE - skb->len, GFP_ATOMIC);
 196                 dev_kfree_skb(skb);
 197                 if (skb2 == NULL) {
 198                         brvcc->copies_failed++;
 199                         return 0;
 200                 }
 201                 skb = skb2;
 202                 memset(skb->tail, 0, MIN_PKT_SIZE - skb->len);
 203                 skb_put(skb, MIN_PKT_SIZE - skb->len);
 204         }
 205 #endif
 206
 207         skb_debug(skb);
 208
 209         ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
 210         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
 211         if (!atm_may_send(atmvcc, skb->truesize)) {
 212                 /* we free this here for now, because we cannot know in a higher
 213                         layer whether the skb point it supplied wasn't freed yet.
 214                         now, it always is.
 215                 */
 216                 dev_kfree_skb(skb);
 217                 return 0;
 218                 }
 219         atomic_add(skb->truesize, &atmvcc->sk->sk_wmem_alloc);
 220         ATM_SKB(skb)->atm_options = atmvcc->atm_options;
 221         brdev->stats.tx_packets++;
 222         brdev->stats.tx_bytes += skb->len;
 223 #if defined(CONFIG_MIPS_BRCM)
 224         if (atmvcc->send(atmvcc, skb) != 0)
 225             brdev->stats.tx_dropped++;
 226 #else
 227         atmvcc->send(atmvcc, skb);
 228 #endif
 229
 230         return 1;
 231 }
 232
 233 static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb,
 234         struct br2684_dev *brdev)
 235 {
 236         return list_empty(&brdev->brvccs) ? NULL :
 237             list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */
 238 }
 239
 240 static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
 241 {
 242         struct br2684_dev *brdev = BRPRIV(dev);
 243         struct br2684_vcc *brvcc;
 244
 245         DPRINTK("br2684_start_xmit, skb->dst=%p\n", skb->dst);
 246         read_lock(&devs_lock);
 247         brvcc = pick_outgoing_vcc(skb, brdev);
 248         if (brvcc == NULL) {
 249                 DPRINTK("no vcc attached to dev %s\n", dev->name);
 250                 brdev->stats.tx_errors++;
 251                 brdev->stats.tx_carrier_errors++;
 252                 /* netif_stop_queue(dev); */
 253                 dev_kfree_skb(skb);
 254                 read_unlock(&devs_lock);
 255                 return -EUNATCH;
 256         }
 257
 258 #if defined(CONFIG_MIPS_BRCM)
 259         if (brvcc->proto_filter & FILTER_PPPOE) {
 260                 if ((skb->protocol != htons(ETH_P_PPP_DISC)) && (skb->protocol != htons(ETH_P_PPP_SES))) {
 261                         DPRINTK("non-PPPOE packet dropped on TX dev %s\n", dev->name);
 262                         brdev->stats.tx_dropped++;
 263                         dev_kfree_skb(skb);
 264                         read_unlock(&devs_lock);
 265                         return 0;
 266                 }
 267         }
 268 #endif
 269         if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
 270                 /*
 271                  * We should probably use netif_*_queue() here, but that
 272                  * involves added complication.  We need to walk before
 273                  * we can run
 274                  */
 275                 /* don't free here! this pointer might be no longer valid!
 276                 dev_kfree_skb(skb);
 277                 */
 278                 brdev->stats.tx_errors++;
 279                 brdev->stats.tx_fifo_errors++;
 280         }
 281         read_unlock(&devs_lock);
 282         return 0;
 283 }
 284
 285 static struct net_device_stats *br2684_get_stats(struct net_device *dev)
 286 {
 287         DPRINTK("br2684_get_stats\n");
 288         return &BRPRIV(dev)->stats;
 289 }
 290
 291 #ifdef FASTER_VERSION
 292 /*
 293  * These mirror eth_header and eth_header_cache.  They are not usually
 294  * exported for use in modules, so we grab them from net_device
 295  * after ether_setup() is done with it.  Bit of a hack.
 296  */
 297 static int (*my_eth_header)(struct sk_buff *, struct net_device *,
 298         unsigned short, void *, void *, unsigned);
 299 static int (*my_eth_header_cache)(struct neighbour *, struct hh_cache *);
 300
 301 static int
 302 br2684_header(struct sk_buff *skb, struct net_device *dev,
 303               unsigned short type, void *daddr, void *saddr, unsigned len)
 304 {
 305         u16 *pad_before_eth;
 306         int t = my_eth_header(skb, dev, type, daddr, saddr, len);
 307         if (t > 0) {
 308                 pad_before_eth = (u16 *) skb_push(skb, 2);
 309                 *pad_before_eth = 0;
 310                 return dev->hard_header_len;    /* or return 16; ? */
 311         } else
 312                 return t;
 313 }
 314
 315 static int
 316 br2684_header_cache(struct neighbour *neigh, struct hh_cache *hh)
 317 {
 318 /* hh_data is 16 bytes long. if encaps is ether-llc we need 24, so
 319 xmit will add the additional header part in that case */
 320         u16 *pad_before_eth = (u16 *)(hh->hh_data);
 321         int t = my_eth_header_cache(neigh, hh);
 322         DPRINTK("br2684_header_cache, neigh=%p, hh_cache=%p\n", neigh, hh);
 323         if (t < 0)
 324                 return t;
 325         else {
 326                 *pad_before_eth = 0;
 327                 hh->hh_len = PADLEN + ETH_HLEN;
 328         }
 329         return 0;
 330 }
 331
 332 /*
 333  * This is similar to eth_type_trans, which cannot be used because of
 334  * our dev->hard_header_len
 335  */
 336 static inline unsigned short br_type_trans(struct sk_buff *skb,
 337                                                struct net_device *dev)
 338 {
 339         struct ethhdr *eth;
 340         unsigned char *rawp;
 341         eth = skb->mac.ethernet;
 342
 343         if (*eth->h_dest & 1) {
 344                 if (memcmp(eth->h_dest, dev->broadcast, ETH_ALEN) == 0)
 345                         skb->pkt_type = PACKET_BROADCAST;
 346                 else
 347                         skb->pkt_type = PACKET_MULTICAST;
 348         }
 349
 350         else if (memcmp(eth->h_dest, dev->dev_addr, ETH_ALEN))
 351                 skb->pkt_type = PACKET_OTHERHOST;
 352
 353         if (ntohs(eth->h_proto) >= 1536)
 354                 return eth->h_proto;
 355
 356         rawp = skb->data;
 357
 358         /*
 359          * This is a magic hack to spot IPX packets. Older Novell breaks
 360          * the protocol design and runs IPX over 802.3 without an 802.2 LLC
 361          * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
 362          * won't work for fault tolerant netware but does for the rest.
 363          */
 364         if (*(unsigned short *) rawp == 0xFFFF)
 365                 return htons(ETH_P_802_3);
 366
 367         /*
 368          * Real 802.2 LLC
 369          */
 370         return htons(ETH_P_802_2);
 371 }
 372 #endif /* FASTER_VERSION */
 373
 374 /*
 375  * We remember when the MAC gets set, so we don't override it later with
 376  * the ESI of the ATM card of the first VC
 377  */
 378 static int (*my_eth_mac_addr)(struct net_device *, void *);
 379 static int br2684_mac_addr(struct net_device *dev, void *p)
 380 {
 381         int err = my_eth_mac_addr(dev, p);
 382         if (!err)
 383                 BRPRIV(dev)->mac_was_set = 1;
 384         return err;
 385 }
 386
 387 #ifdef CONFIG_ATM_BR2684_IPFILTER
 388 /* this IOCTL is experimental. */
 389 static int br2684_setfilt(struct atm_vcc *atmvcc, void __user *arg)
 390 {
 391         struct br2684_vcc *brvcc;
 392         struct br2684_filter_set fs;
 393
 394         if (copy_from_user(&fs, arg, sizeof fs))
 395                 return -EFAULT;
 396         if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
 397                 /*
 398                  * This is really a per-vcc thing, but we can also search
 399                  * by device
 400                  */
 401                 struct br2684_dev *brdev;
 402                 read_lock(&devs_lock);
 403                 brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
 404                 if (brdev == NULL || list_empty(&brdev->brvccs) ||
 405                     brdev->brvccs.next != brdev->brvccs.prev)  /* >1 VCC */
 406                         brvcc = NULL;
 407                 else
 408                         brvcc = list_entry_brvcc(brdev->brvccs.next);
 409                 read_unlock(&devs_lock);
 410                 if (brvcc == NULL)
 411                         return -ESRCH;
 412         } else
 413                 brvcc = BR2684_VCC(atmvcc);
 414         memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
 415         return 0;
 416 }
 417
 418 /* Returns 1 if packet should be dropped */
 419 static inline int
 420 packet_fails_filter(u16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
 421 {
 422         if (brvcc->filter.netmask == 0)
 423                 return 0;                       /* no filter in place */
 424         if (type == __constant_htons(ETH_P_IP) &&
 425             (((struct iphdr *) (skb->data))->daddr & brvcc->filter.
 426              netmask) == brvcc->filter.prefix)
 427                 return 0;
 428         if (type == __constant_htons(ETH_P_ARP))
 429                 return 0;
 430         /* TODO: we should probably filter ARPs too.. don't want to have
 431          *   them returning values that don't make sense, or is that ok?
 432          */
 433         return 1;               /* drop */
 434 }
 435 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 436
 437 static void br2684_close_vcc(struct br2684_vcc *brvcc)
 438 {
 439         DPRINTK("removing VCC %p from dev %p\n", brvcc, brvcc->device);
 440         write_lock_irq(&devs_lock);
 441         list_del(&brvcc->brvccs);
 442         write_unlock_irq(&devs_lock);
 443         brvcc->atmvcc->user_back = NULL;        /* what about vcc->recvq ??? */
 444         brvcc->old_push(brvcc->atmvcc, NULL);   /* pass on the bad news */
 445         kfree(brvcc);
 446         module_put(THIS_MODULE);
 447 }
 448
 449 /* when AAL5 PDU comes in: */
 450 static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
 451 {
 452         struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
 453         struct net_device *net_dev = brvcc->device;
 454         struct br2684_dev *brdev = BRPRIV(net_dev);
 455         int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
 456
 457         DPRINTK("br2684_push\n");
 458
 459         if (unlikely(skb == NULL)) {
 460                 /* skb==NULL means VCC is being destroyed */
 461                 br2684_close_vcc(brvcc);
 462                 if (list_empty(&brdev->brvccs)) {
 463                         read_lock(&devs_lock);
 464                         list_del(&brdev->br2684_devs);
 465                         read_unlock(&devs_lock);
 466                         unregister_netdev(net_dev);
 467                         free_netdev(net_dev);
 468                 }
 469                 return;
 470         }
 471 #if defined(CONFIG_MIPS_BRCM)
 472         //skb->__unused=FROM_WAN;
 473 #endif
 474
 475         skb_debug(skb);
 476         atm_return(atmvcc, skb->truesize);
 477         DPRINTK("skb from brdev %p\n", brdev);
 478         if (brvcc->encaps == e_llc) {
 479                 /* let us waste some time for checking the encapsulation.
 480                    Note, that only 7 char is checked so frames with a valid FCS
 481                    are also accepted (but FCS is not checked of course) */
 482                 if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
 483                         brdev->stats.rx_errors++;
 484                         dev_kfree_skb(skb);
 485                         return;
 486                 }
 487
 488                 /* Strip FCS if present */
 489                 if (skb->len > 7 && skb->data[7] == 0x01)
 490                         __skb_trim(skb, skb->len - 4);
 491         } else {
 492                 plen = PADLEN + ETH_HLEN;       /* pad, dstmac,srcmac, ethtype */
 493                 /* first 2 chars should be 0 */
 494                 if (*((u16 *) (skb->data)) != 0) {
 495                         brdev->stats.rx_errors++;
 496                         dev_kfree_skb(skb);
 497                         return;
 498                 }
 499         }
 500         if (skb->len < plen) {
 501                 brdev->stats.rx_errors++;
 502                 dev_kfree_skb(skb);     /* dev_ not needed? */
 503                 return;
 504         }
 505
 506 #ifdef FASTER_VERSION
 507         /* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier,
 508            than should be. What else should I set? */
 509         skb_pull(skb, plen);
 510         skb->mac.raw = ((char *) (skb->data)) - ETH_HLEN;
 511         skb->pkt_type = PACKET_HOST;
 512 #ifdef CONFIG_BR2684_FAST_TRANS
 513         skb->protocol = ((u16 *) skb->data)[-1];
 514 #else                           /* some protocols might require this: */
 515         skb->protocol = br_type_trans(skb, net_dev);
 516 #endif /* CONFIG_BR2684_FAST_TRANS */
 517 #else
 518         skb_pull(skb, plen - ETH_HLEN);
 519         skb->protocol = eth_type_trans(skb, net_dev);
 520 #endif /* FASTER_VERSION */
 521 #ifdef CONFIG_ATM_BR2684_IPFILTER
 522         if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
 523                 brdev->stats.rx_dropped++;
 524                 dev_kfree_skb(skb);
 525                 return;
 526         }
 527 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 528 #if defined(CONFIG_MIPS_BRCM)
 529         if (brvcc->proto_filter & FILTER_PPPOE) {
 530                 if ((skb->protocol != htons(ETH_P_PPP_DISC)) && (skb->protocol != htons(ETH_P_PPP_SES))) {
 531                         DPRINTK("non-PPPOE packet dropped on RX dev %s\n", net_dev->name);
 532                         brdev->stats.rx_dropped++;
 533                         dev_kfree_skb(skb);
 534                         return;
 535                 }
 536         }
 537 #endif
 538         skb->dev = net_dev;
 539         ATM_SKB(skb)->vcc = atmvcc;     /* needed ? */
 540         DPRINTK("received packet's protocol: %x\n", ntohs(skb->protocol));
 541         skb_debug(skb);
 542         if (unlikely(!(net_dev->flags & IFF_UP))) {
 543                 /* sigh, interface is down */
 544                 brdev->stats.rx_dropped++;
 545                 dev_kfree_skb(skb);
 546                 return;
 547         }
 548         brdev->stats.rx_packets++;
 549         brdev->stats.rx_bytes += skb->len;
 550         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 551         netif_rx(skb);
 552 }
 553
 554 static int br2684_regvcc(struct atm_vcc *atmvcc, void __user *arg)
 555 {
 556 /* assign a vcc to a dev
 557 Note: we do not have explicit unassign, but look at _push()
 558 */
 559         int err;
 560         struct br2684_vcc *brvcc;
 561         struct sk_buff_head copy;
 562         struct sk_buff *skb;
 563         struct br2684_dev *brdev;
 564         struct net_device *net_dev;
 565         struct atm_backend_br2684 be;
 566
 567         if (copy_from_user(&be, arg, sizeof be))
 568                 return -EFAULT;
 569         brvcc = kmalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
 570         if (!brvcc)
 571                 return -ENOMEM;
 572         memset(brvcc, 0, sizeof(struct br2684_vcc));
 573         write_lock_irq(&devs_lock);
 574         net_dev = br2684_find_dev(&be.ifspec);
 575         if (net_dev == NULL) {
 576                 printk(KERN_ERR
 577                     "br2684: tried to attach to non-existant device\n");
 578                 err = -ENXIO;
 579                 goto error;
 580         }
 581         brdev = BRPRIV(net_dev);
 582         if (atmvcc->push == NULL) {
 583                 err = -EBADFD;
 584                 goto error;
 585         }
 586         if (!list_empty(&brdev->brvccs)) {
 587                 /* Only 1 VCC/dev right now */
 588                 err = -EEXIST;
 589                 goto error;
 590         }
 591         if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
 592             be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
 593             BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
 594             be.min_size != 0) {
 595                 err = -EINVAL;
 596                 goto error;
 597         }
 598         DPRINTK("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
 599                 brvcc);
 600         if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
 601                 unsigned char *esi = atmvcc->dev->esi;
 602                 if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
 603                         memcpy(net_dev->dev_addr, esi, net_dev->addr_len);
 604                 else
 605                         net_dev->dev_addr[2] = 1;
 606         }
 607         list_add(&brvcc->brvccs, &brdev->brvccs);
 608         write_unlock_irq(&devs_lock);
 609         brvcc->device = net_dev;
 610         brvcc->atmvcc = atmvcc;
 611         atmvcc->user_back = brvcc;
 612         brvcc->encaps = (enum br2684_encaps) be.encaps;
 613         brvcc->old_push = atmvcc->push;
 614 #if defined(CONFIG_MIPS_BRCM)
 615         brvcc->proto_filter |= be.proto_filter;
 616 #endif
 617         barrier();
 618         atmvcc->push = br2684_push;
 619         skb_queue_head_init(&copy);
 620         skb_migrate(&atmvcc->sk->sk_receive_queue, &copy);
 621         while ((skb = skb_dequeue(&copy)) != NULL) {
 622                 BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
 623                 BRPRIV(skb->dev)->stats.rx_packets--;
 624                 br2684_push(atmvcc, skb);
 625         }
 626         __module_get(THIS_MODULE);
 627         return 0;
 628     error:
 629         write_unlock_irq(&devs_lock);
 630         kfree(brvcc);
 631         return err;
 632 }
 633
 634 static void br2684_setup(struct net_device *netdev)
 635 {
 636         struct br2684_dev *brdev = BRPRIV(netdev);
 637
 638         ether_setup(netdev);
 639         brdev->net_dev = netdev;
 640
 641 #ifdef FASTER_VERSION
 642         my_eth_header = netdev->hard_header;
 643         netdev->hard_header = br2684_header;
 644         my_eth_header_cache = netdev->hard_header_cache;
 645         netdev->hard_header_cache = br2684_header_cache;
 646         netdev->hard_header_len = sizeof(llc_oui_pid_pad) + ETH_HLEN;   /* 10 + 14 */
 647 #endif
 648         my_eth_mac_addr = netdev->set_mac_address;
 649         netdev->set_mac_address = br2684_mac_addr;
 650         netdev->hard_start_xmit = br2684_start_xmit;
 651         netdev->get_stats = br2684_get_stats;
 652
 653         INIT_LIST_HEAD(&brdev->brvccs);
 654 }
 655
 656 static int br2684_create(void __user *arg)
 657 {
 658         int err;
 659         struct net_device *netdev;
 660         struct br2684_dev *brdev;
 661         struct atm_newif_br2684 ni;
 662
 663         DPRINTK("br2684_create\n");
 664
 665         if (copy_from_user(&ni, arg, sizeof ni)) {
 666                 return -EFAULT;
 667         }
 668         if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
 669                 return -EINVAL;
 670         }
 671
 672         netdev = alloc_netdev(sizeof(struct br2684_dev),
 673                               ni.ifname[0] ? ni.ifname : "nas%d",
 674                               br2684_setup);
 675         if (!netdev)
 676                 return -ENOMEM;
 677
 678         brdev = BRPRIV(netdev);
 679
 680         DPRINTK("registered netdev %s\n", netdev->name);
 681         /* open, stop, do_ioctl ? */
 682         err = register_netdev(netdev);
 683         if (err < 0) {
 684                 printk(KERN_ERR "br2684_create: register_netdev failed\n");
 685                 free_netdev(netdev);
 686                 return err;
 687         }
 688
 689         write_lock_irq(&devs_lock);
 690         brdev->number = list_empty(&br2684_devs) ? 1 :
 691             BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
 692         list_add_tail(&brdev->br2684_devs, &br2684_devs);
 693         write_unlock_irq(&devs_lock);
 694         return 0;
 695 }
 696
 697 /*
 698  * This handles ioctls actually performed on our vcc - we must return
 699  * -ENOIOCTLCMD for any unrecognized ioctl
 700  */
 701 static int br2684_ioctl(struct socket *sock, unsigned int cmd,
 702         unsigned long arg)
 703 {
 704         struct atm_vcc *atmvcc = ATM_SD(sock);
 705         void __user *argp = (void __user *)arg;
 706
 707         int err;
 708         switch(cmd) {
 709         case ATM_SETBACKEND:
 710         case ATM_NEWBACKENDIF: {
 711                 atm_backend_t b;
 712                 err = get_user(b, (atm_backend_t __user *) argp);
 713                 if (err)
 714                         return -EFAULT;
 715                 if (b != ATM_BACKEND_BR2684)
 716                         return -ENOIOCTLCMD;
 717                 if (!capable(CAP_NET_ADMIN))
 718                         return -EPERM;
 719                 if (cmd == ATM_SETBACKEND)
 720                         return br2684_regvcc(atmvcc, argp);
 721                 else
 722                         return br2684_create(argp);
 723                 }
 724 #ifdef CONFIG_ATM_BR2684_IPFILTER
 725         case BR2684_SETFILT:
 726                 if (atmvcc->push != br2684_push)
 727                         return -ENOIOCTLCMD;
 728                 if (!capable(CAP_NET_ADMIN))
 729                         return -EPERM;
 730                 err = br2684_setfilt(atmvcc, argp);
 731                 return err;
 732 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 733         }
 734         return -ENOIOCTLCMD;
 735 }
 736
 737 static struct atm_ioctl br2684_ioctl_ops = {
 738         .owner  = THIS_MODULE,
 739         .ioctl  = br2684_ioctl,
 740 };
 741
 742
 743 #ifdef CONFIG_PROC_FS
 744 static void *br2684_seq_start(struct seq_file *seq, loff_t *pos)
 745 {
 746         loff_t offs = 0;
 747         struct br2684_dev *brd;
 748
 749         read_lock(&devs_lock);
 750
 751         list_for_each_entry(brd, &br2684_devs, br2684_devs) {
 752                 if (offs == *pos)
 753                         return brd;
 754                 ++offs;
 755         }
 756         return NULL;
 757 }
 758
 759 static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 760 {
 761         struct br2684_dev *brd = v;
 762
 763         ++*pos;
 764
 765         brd = list_entry(brd->br2684_devs.next,
 766                          struct br2684_dev, br2684_devs);
 767         return (&brd->br2684_devs != &br2684_devs) ? brd : NULL;
 768 }
 769
 770 static void br2684_seq_stop(struct seq_file *seq, void *v)
 771 {
 772         read_unlock(&devs_lock);
 773 }
 774
 775 static int br2684_seq_show(struct seq_file *seq, void *v)
 776 {
 777         const struct br2684_dev *brdev = v;
 778         const struct net_device *net_dev = brdev->net_dev;
 779         const struct br2684_vcc *brvcc;
 780
 781         seq_printf(seq, "dev %.16s: num=%d, mac=%02X:%02X:"
 782                        "%02X:%02X:%02X:%02X (%s)\n", net_dev->name,
 783                        brdev->number,
 784                        net_dev->dev_addr[0],
 785                        net_dev->dev_addr[1],
 786                        net_dev->dev_addr[2],
 787                        net_dev->dev_addr[3],
 788                        net_dev->dev_addr[4],
 789                        net_dev->dev_addr[5],
 790                        brdev->mac_was_set ? "set" : "auto");
 791
 792         list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
 793                 seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
 794 #ifndef FASTER_VERSION
 795                                     ", failed copies %u/%u"
 796 #endif /* FASTER_VERSION */
 797                                     "\n", brvcc->atmvcc->dev->number,
 798                                     brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
 799                                     (brvcc->encaps == e_llc) ? "LLC" : "VC"
 800 #ifndef FASTER_VERSION
 801                                     , brvcc->copies_failed
 802                                     , brvcc->copies_needed
 803 #endif /* FASTER_VERSION */
 804                                     );
 805 #ifdef CONFIG_ATM_BR2684_IPFILTER
 806 #define b1(var, byte)   ((u8 *) &brvcc->filter.var)[byte]
 807 #define bs(var)         b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
 808                         if (brvcc->filter.netmask != 0)
 809                                 seq_printf(seq, "    filter=%d.%d.%d.%d/"
 810                                                 "%d.%d.%d.%d\n",
 811                                                 bs(prefix), bs(netmask));
 812 #undef bs
 813 #undef b1
 814 #endif /* CONFIG_ATM_BR2684_IPFILTER */
 815         }
 816         return 0;
 817 }
 818
 819 static struct seq_operations br2684_seq_ops = {
 820         .start = br2684_seq_start,
 821         .next  = br2684_seq_next,
 822         .stop  = br2684_seq_stop,
 823         .show  = br2684_seq_show,
 824 };
 825
 826 static int br2684_proc_open(struct inode *inode, struct file *file)
 827 {
 828         return seq_open(file, &br2684_seq_ops);
 829 }
 830
 831 static struct file_operations br2684_proc_ops = {
 832         .owner   = THIS_MODULE,
 833         .open    = br2684_proc_open,
 834         .read    = seq_read,
 835         .llseek  = seq_lseek,
 836         .release = seq_release,
 837 };
 838
 839 extern struct proc_dir_entry *atm_proc_root;    /* from proc.c */
 840 #endif
 841
 842 static int __init br2684_init(void)
 843 {
 844 #ifdef CONFIG_PROC_FS
 845         struct proc_dir_entry *p;
 846         if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
 847                 return -ENOMEM;
 848         p->proc_fops = &br2684_proc_ops;
 849 #endif
 850         register_atm_ioctl(&br2684_ioctl_ops);
 851         return 0;
 852 }
 853
 854 static void __exit br2684_exit(void)
 855 {
 856         struct net_device *net_dev;
 857         struct br2684_dev *brdev;
 858         struct br2684_vcc *brvcc;
 859         deregister_atm_ioctl(&br2684_ioctl_ops);
 860
 861 #ifdef CONFIG_PROC_FS
 862         remove_proc_entry("br2684", atm_proc_root);
 863 #endif
 864
 865         while (!list_empty(&br2684_devs)) {
 866                 net_dev = list_entry_brdev(br2684_devs.next);
 867                 brdev = BRPRIV(net_dev);
 868                 while (!list_empty(&brdev->brvccs)) {
 869                         brvcc = list_entry_brvcc(brdev->brvccs.next);
 870                         br2684_close_vcc(brvcc);
 871                 }
 872
 873                 list_del(&brdev->br2684_devs);
 874                 unregister_netdev(net_dev);
 875                 free_netdev(net_dev);
 876         }
 877 }
 878
 879 module_init(br2684_init);
 880 module_exit(br2684_exit);
 881
 882 MODULE_AUTHOR("Marcell GAL");
 883 MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
 884 MODULE_LICENSE("GPL");