linux/drivers/net/wan/dlci.c
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   1/*
   2 * DLCI         Implementation of Frame Relay protocol for Linux, according to
   3 *              RFC 1490.  This generic device provides en/decapsulation for an
   4 *              underlying hardware driver.  Routes & IPs are assigned to these
   5 *              interfaces.  Requires 'dlcicfg' program to create usable 
   6 *              interfaces, the initial one, 'dlci' is for IOCTL use only.
   7 *
   8 * Version:     @(#)dlci.c      0.35    4 Jan 1997
   9 *
  10 * Author:      Mike McLagan <mike.mclagan@linux.org>
  11 *
  12 * Changes:
  13 *
  14 *              0.15    Mike Mclagan    Packet freeing, bug in kmalloc call
  15 *                                      DLCI_RET handling
  16 *              0.20    Mike McLagan    More conservative on which packets
  17 *                                      are returned for retry and which are
  18 *                                      are dropped.  If DLCI_RET_DROP is
  19 *                                      returned from the FRAD, the packet is
  20 *                                      sent back to Linux for re-transmission
  21 *              0.25    Mike McLagan    Converted to use SIOC IOCTL calls
  22 *              0.30    Jim Freeman     Fixed to allow IPX traffic
  23 *              0.35    Michael Elizabeth       Fixed incorrect memcpy_fromfs
  24 *
  25 *              This program is free software; you can redistribute it and/or
  26 *              modify it under the terms of the GNU General Public License
  27 *              as published by the Free Software Foundation; either version
  28 *              2 of the License, or (at your option) any later version.
  29 */
  30
  31#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  32
  33#include <linux/module.h>
  34#include <linux/kernel.h>
  35#include <linux/types.h>
  36#include <linux/fcntl.h>
  37#include <linux/interrupt.h>
  38#include <linux/ptrace.h>
  39#include <linux/ioport.h>
  40#include <linux/in.h>
  41#include <linux/init.h>
  42#include <linux/slab.h>
  43#include <linux/string.h>
  44#include <linux/errno.h>
  45#include <linux/netdevice.h>
  46#include <linux/skbuff.h>
  47#include <linux/if_arp.h>
  48#include <linux/if_frad.h>
  49#include <linux/bitops.h>
  50
  51#include <net/sock.h>
  52
  53#include <asm/io.h>
  54#include <asm/dma.h>
  55#include <asm/uaccess.h>
  56
  57static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
  58
  59static LIST_HEAD(dlci_devs);
  60
  61static void dlci_setup(struct net_device *);
  62
  63/* 
  64 * these encapsulate the RFC 1490 requirements as well as 
  65 * deal with packet transmission and reception, working with
  66 * the upper network layers 
  67 */
  68
  69static int dlci_header(struct sk_buff *skb, struct net_device *dev, 
  70                       unsigned short type, const void *daddr,
  71                       const void *saddr, unsigned len)
  72{
  73        struct frhdr            hdr;
  74        unsigned int            hlen;
  75        char                    *dest;
  76
  77        hdr.control = FRAD_I_UI;
  78        switch (type)
  79        {
  80                case ETH_P_IP:
  81                        hdr.IP_NLPID = FRAD_P_IP;
  82                        hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
  83                        break;
  84
  85                /* feel free to add other types, if necessary */
  86
  87                default:
  88                        hdr.pad = FRAD_P_PADDING;
  89                        hdr.NLPID = FRAD_P_SNAP;
  90                        memset(hdr.OUI, 0, sizeof(hdr.OUI));
  91                        hdr.PID = htons(type);
  92                        hlen = sizeof(hdr);
  93                        break;
  94        }
  95
  96        dest = skb_push(skb, hlen);
  97        if (!dest)
  98                return 0;
  99
 100        memcpy(dest, &hdr, hlen);
 101
 102        return hlen;
 103}
 104
 105static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
 106{
 107        struct frhdr            *hdr;
 108        int                                     process, header;
 109
 110        if (!pskb_may_pull(skb, sizeof(*hdr))) {
 111                netdev_notice(dev, "invalid data no header\n");
 112                dev->stats.rx_errors++;
 113                kfree_skb(skb);
 114                return;
 115        }
 116
 117        hdr = (struct frhdr *) skb->data;
 118        process = 0;
 119        header = 0;
 120        skb->dev = dev;
 121
 122        if (hdr->control != FRAD_I_UI)
 123        {
 124                netdev_notice(dev, "Invalid header flag 0x%02X\n",
 125                              hdr->control);
 126                dev->stats.rx_errors++;
 127        }
 128        else
 129                switch (hdr->IP_NLPID)
 130                {
 131                        case FRAD_P_PADDING:
 132                                if (hdr->NLPID != FRAD_P_SNAP)
 133                                {
 134                                        netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 135                                                      hdr->NLPID);
 136                                        dev->stats.rx_errors++;
 137                                        break;
 138                                }
 139         
 140                                if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
 141                                {
 142                                        netdev_notice(dev, "Unsupported organizationally unique identifier 0x%02X-%02X-%02X\n",
 143                                                      hdr->OUI[0],
 144                                                      hdr->OUI[1],
 145                                                      hdr->OUI[2]);
 146                                        dev->stats.rx_errors++;
 147                                        break;
 148                                }
 149
 150                                /* at this point, it's an EtherType frame */
 151                                header = sizeof(struct frhdr);
 152                                /* Already in network order ! */
 153                                skb->protocol = hdr->PID;
 154                                process = 1;
 155                                break;
 156
 157                        case FRAD_P_IP:
 158                                header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
 159                                skb->protocol = htons(ETH_P_IP);
 160                                process = 1;
 161                                break;
 162
 163                        case FRAD_P_SNAP:
 164                        case FRAD_P_Q933:
 165                        case FRAD_P_CLNP:
 166                                netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 167                                              hdr->pad);
 168                                dev->stats.rx_errors++;
 169                                break;
 170
 171                        default:
 172                                netdev_notice(dev, "Invalid pad byte 0x%02X\n",
 173                                              hdr->pad);
 174                                dev->stats.rx_errors++;
 175                                break;                          
 176                }
 177
 178        if (process)
 179        {
 180                /* we've set up the protocol, so discard the header */
 181                skb_reset_mac_header(skb);
 182                skb_pull(skb, header);
 183                dev->stats.rx_bytes += skb->len;
 184                netif_rx(skb);
 185                dev->stats.rx_packets++;
 186        }
 187        else
 188                dev_kfree_skb(skb);
 189}
 190
 191static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 192{
 193        struct dlci_local *dlp = netdev_priv(dev);
 194
 195        if (skb) {
 196                struct netdev_queue *txq = skb_get_tx_queue(dev, skb);
 197                netdev_start_xmit(skb, dlp->slave, txq, false);
 198        }
 199        return NETDEV_TX_OK;
 200}
 201
 202static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 203{
 204        struct dlci_conf        config;
 205        struct dlci_local       *dlp;
 206        struct frad_local       *flp;
 207        int                     err;
 208
 209        dlp = netdev_priv(dev);
 210
 211        flp = netdev_priv(dlp->slave);
 212
 213        if (!get)
 214        {
 215                if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 216                        return -EFAULT;
 217                if (config.flags & ~DLCI_VALID_FLAGS)
 218                        return -EINVAL;
 219                memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 220                dlp->configured = 1;
 221        }
 222
 223        err = (*flp->dlci_conf)(dlp->slave, dev, get);
 224        if (err)
 225                return err;
 226
 227        if (get)
 228        {
 229                if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 230                        return -EFAULT;
 231        }
 232
 233        return 0;
 234}
 235
 236static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 237{
 238        struct dlci_local *dlp;
 239
 240        if (!capable(CAP_NET_ADMIN))
 241                return -EPERM;
 242
 243        dlp = netdev_priv(dev);
 244
 245        switch (cmd)
 246        {
 247                case DLCI_GET_SLAVE:
 248                        if (!*(short *)(dev->dev_addr))
 249                                return -EINVAL;
 250
 251                        strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 252                        break;
 253
 254                case DLCI_GET_CONF:
 255                case DLCI_SET_CONF:
 256                        if (!*(short *)(dev->dev_addr))
 257                                return -EINVAL;
 258
 259                        return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
 260
 261                default: 
 262                        return -EOPNOTSUPP;
 263        }
 264        return 0;
 265}
 266
 267static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 268{
 269        struct dlci_local *dlp = netdev_priv(dev);
 270
 271        return dev_set_mtu(dlp->slave, new_mtu);
 272}
 273
 274static int dlci_open(struct net_device *dev)
 275{
 276        struct dlci_local       *dlp;
 277        struct frad_local       *flp;
 278        int                     err;
 279
 280        dlp = netdev_priv(dev);
 281
 282        if (!*(short *)(dev->dev_addr))
 283                return -EINVAL;
 284
 285        if (!netif_running(dlp->slave))
 286                return -ENOTCONN;
 287
 288        flp = netdev_priv(dlp->slave);
 289        err = (*flp->activate)(dlp->slave, dev);
 290        if (err)
 291                return err;
 292
 293        netif_start_queue(dev);
 294
 295        return 0;
 296}
 297
 298static int dlci_close(struct net_device *dev)
 299{
 300        struct dlci_local       *dlp;
 301        struct frad_local       *flp;
 302        int                     err;
 303
 304        netif_stop_queue(dev);
 305
 306        dlp = netdev_priv(dev);
 307
 308        flp = netdev_priv(dlp->slave);
 309        err = (*flp->deactivate)(dlp->slave, dev);
 310
 311        return 0;
 312}
 313
 314static int dlci_add(struct dlci_add *dlci)
 315{
 316        struct net_device       *master, *slave;
 317        struct dlci_local       *dlp;
 318        struct frad_local       *flp;
 319        int                     err = -EINVAL;
 320
 321
 322        /* validate slave device */
 323        slave = dev_get_by_name(&init_net, dlci->devname);
 324        if (!slave)
 325                return -ENODEV;
 326
 327        if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 328                goto err1;
 329
 330        /* create device name */
 331        master = alloc_netdev(sizeof(struct dlci_local), "dlci%d",
 332                              NET_NAME_UNKNOWN, dlci_setup);
 333        if (!master) {
 334                err = -ENOMEM;
 335                goto err1;
 336        }
 337
 338        /* make sure same slave not already registered */
 339        rtnl_lock();
 340        list_for_each_entry(dlp, &dlci_devs, list) {
 341                if (dlp->slave == slave) {
 342                        err = -EBUSY;
 343                        goto err2;
 344                }
 345        }
 346
 347        *(short *)(master->dev_addr) = dlci->dlci;
 348
 349        dlp = netdev_priv(master);
 350        dlp->slave = slave;
 351        dlp->master = master;
 352
 353        flp = netdev_priv(slave);
 354        err = (*flp->assoc)(slave, master);
 355        if (err < 0)
 356                goto err2;
 357
 358        err = register_netdevice(master);
 359        if (err < 0) 
 360                goto err2;
 361
 362        strcpy(dlci->devname, master->name);
 363
 364        list_add(&dlp->list, &dlci_devs);
 365        rtnl_unlock();
 366
 367        return 0;
 368
 369 err2:
 370        rtnl_unlock();
 371        free_netdev(master);
 372 err1:
 373        dev_put(slave);
 374        return err;
 375}
 376
 377static int dlci_del(struct dlci_add *dlci)
 378{
 379        struct dlci_local       *dlp;
 380        struct frad_local       *flp;
 381        struct net_device       *master, *slave;
 382        int                     err;
 383        bool                    found = false;
 384
 385        rtnl_lock();
 386
 387        /* validate slave device */
 388        master = __dev_get_by_name(&init_net, dlci->devname);
 389        if (!master) {
 390                err = -ENODEV;
 391                goto out;
 392        }
 393
 394        list_for_each_entry(dlp, &dlci_devs, list) {
 395                if (dlp->master == master) {
 396                        found = true;
 397                        break;
 398                }
 399        }
 400        if (!found) {
 401                err = -ENODEV;
 402                goto out;
 403        }
 404
 405        if (netif_running(master)) {
 406                err = -EBUSY;
 407                goto out;
 408        }
 409
 410        dlp = netdev_priv(master);
 411        slave = dlp->slave;
 412        flp = netdev_priv(slave);
 413
 414        err = (*flp->deassoc)(slave, master);
 415        if (!err) {
 416                list_del(&dlp->list);
 417
 418                unregister_netdevice(master);
 419
 420                dev_put(slave);
 421        }
 422out:
 423        rtnl_unlock();
 424        return err;
 425}
 426
 427static int dlci_ioctl(unsigned int cmd, void __user *arg)
 428{
 429        struct dlci_add add;
 430        int err;
 431        
 432        if (!capable(CAP_NET_ADMIN))
 433                return -EPERM;
 434
 435        if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
 436                return -EFAULT;
 437
 438        switch (cmd)
 439        {
 440                case SIOCADDDLCI:
 441                        err = dlci_add(&add);
 442
 443                        if (!err)
 444                                if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
 445                                        return -EFAULT;
 446                        break;
 447
 448                case SIOCDELDLCI:
 449                        err = dlci_del(&add);
 450                        break;
 451
 452                default:
 453                        err = -EINVAL;
 454        }
 455
 456        return err;
 457}
 458
 459static const struct header_ops dlci_header_ops = {
 460        .create = dlci_header,
 461};
 462
 463static const struct net_device_ops dlci_netdev_ops = {
 464        .ndo_open       = dlci_open,
 465        .ndo_stop       = dlci_close,
 466        .ndo_do_ioctl   = dlci_dev_ioctl,
 467        .ndo_start_xmit = dlci_transmit,
 468        .ndo_change_mtu = dlci_change_mtu,
 469};
 470
 471static void dlci_setup(struct net_device *dev)
 472{
 473        struct dlci_local *dlp = netdev_priv(dev);
 474
 475        dev->flags              = 0;
 476        dev->header_ops         = &dlci_header_ops;
 477        dev->netdev_ops         = &dlci_netdev_ops;
 478        dev->destructor         = free_netdev;
 479
 480        dlp->receive            = dlci_receive;
 481
 482        dev->type               = ARPHRD_DLCI;
 483        dev->hard_header_len    = sizeof(struct frhdr);
 484        dev->addr_len           = sizeof(short);
 485
 486}
 487
 488/* if slave is unregistering, then cleanup master */
 489static int dlci_dev_event(struct notifier_block *unused,
 490                          unsigned long event, void *ptr)
 491{
 492        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 493
 494        if (dev_net(dev) != &init_net)
 495                return NOTIFY_DONE;
 496
 497        if (event == NETDEV_UNREGISTER) {
 498                struct dlci_local *dlp;
 499
 500                list_for_each_entry(dlp, &dlci_devs, list) {
 501                        if (dlp->slave == dev) {
 502                                list_del(&dlp->list);
 503                                unregister_netdevice(dlp->master);
 504                                dev_put(dlp->slave);
 505                                break;
 506                        }
 507                }
 508        }
 509        return NOTIFY_DONE;
 510}
 511
 512static struct notifier_block dlci_notifier = {
 513        .notifier_call = dlci_dev_event,
 514};
 515
 516static int __init init_dlci(void)
 517{
 518        dlci_ioctl_set(dlci_ioctl);
 519        register_netdevice_notifier(&dlci_notifier);
 520
 521        printk("%s.\n", version);
 522
 523        return 0;
 524}
 525
 526static void __exit dlci_exit(void)
 527{
 528        struct dlci_local       *dlp, *nxt;
 529        
 530        dlci_ioctl_set(NULL);
 531        unregister_netdevice_notifier(&dlci_notifier);
 532
 533        rtnl_lock();
 534        list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 535                unregister_netdevice(dlp->master);
 536                dev_put(dlp->slave);
 537        }
 538        rtnl_unlock();
 539}
 540
 541module_init(init_dlci);
 542module_exit(dlci_exit);
 543
 544MODULE_AUTHOR("Mike McLagan");
 545MODULE_DESCRIPTION("Frame Relay DLCI layer");
 546MODULE_LICENSE("GPL");
 547