linux/drivers/net/wan/dlci.c
<<
>>
Prefs
   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                dlp->slave->netdev_ops->ndo_start_xmit(skb, dlp->slave);
 197        return NETDEV_TX_OK;
 198}
 199
 200static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 201{
 202        struct dlci_conf        config;
 203        struct dlci_local       *dlp;
 204        struct frad_local       *flp;
 205        int                     err;
 206
 207        dlp = netdev_priv(dev);
 208
 209        flp = netdev_priv(dlp->slave);
 210
 211        if (!get)
 212        {
 213                if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 214                        return -EFAULT;
 215                if (config.flags & ~DLCI_VALID_FLAGS)
 216                        return -EINVAL;
 217                memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 218                dlp->configured = 1;
 219        }
 220
 221        err = (*flp->dlci_conf)(dlp->slave, dev, get);
 222        if (err)
 223                return err;
 224
 225        if (get)
 226        {
 227                if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 228                        return -EFAULT;
 229        }
 230
 231        return 0;
 232}
 233
 234static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 235{
 236        struct dlci_local *dlp;
 237
 238        if (!capable(CAP_NET_ADMIN))
 239                return -EPERM;
 240
 241        dlp = netdev_priv(dev);
 242
 243        switch (cmd)
 244        {
 245                case DLCI_GET_SLAVE:
 246                        if (!*(short *)(dev->dev_addr))
 247                                return -EINVAL;
 248
 249                        strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 250                        break;
 251
 252                case DLCI_GET_CONF:
 253                case DLCI_SET_CONF:
 254                        if (!*(short *)(dev->dev_addr))
 255                                return -EINVAL;
 256
 257                        return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
 258                        break;
 259
 260                default: 
 261                        return -EOPNOTSUPP;
 262        }
 263        return 0;
 264}
 265
 266static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 267{
 268        struct dlci_local *dlp = netdev_priv(dev);
 269
 270        return dev_set_mtu(dlp->slave, new_mtu);
 271}
 272
 273static int dlci_open(struct net_device *dev)
 274{
 275        struct dlci_local       *dlp;
 276        struct frad_local       *flp;
 277        int                     err;
 278
 279        dlp = netdev_priv(dev);
 280
 281        if (!*(short *)(dev->dev_addr))
 282                return -EINVAL;
 283
 284        if (!netif_running(dlp->slave))
 285                return -ENOTCONN;
 286
 287        flp = netdev_priv(dlp->slave);
 288        err = (*flp->activate)(dlp->slave, dev);
 289        if (err)
 290                return err;
 291
 292        netif_start_queue(dev);
 293
 294        return 0;
 295}
 296
 297static int dlci_close(struct net_device *dev)
 298{
 299        struct dlci_local       *dlp;
 300        struct frad_local       *flp;
 301        int                     err;
 302
 303        netif_stop_queue(dev);
 304
 305        dlp = netdev_priv(dev);
 306
 307        flp = netdev_priv(dlp->slave);
 308        err = (*flp->deactivate)(dlp->slave, dev);
 309
 310        return 0;
 311}
 312
 313static int dlci_add(struct dlci_add *dlci)
 314{
 315        struct net_device       *master, *slave;
 316        struct dlci_local       *dlp;
 317        struct frad_local       *flp;
 318        int                     err = -EINVAL;
 319
 320
 321        /* validate slave device */
 322        slave = dev_get_by_name(&init_net, dlci->devname);
 323        if (!slave)
 324                return -ENODEV;
 325
 326        if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 327                goto err1;
 328
 329        /* create device name */
 330        master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 331                              dlci_setup);
 332        if (!master) {
 333                err = -ENOMEM;
 334                goto err1;
 335        }
 336
 337        /* make sure same slave not already registered */
 338        rtnl_lock();
 339        list_for_each_entry(dlp, &dlci_devs, list) {
 340                if (dlp->slave == slave) {
 341                        err = -EBUSY;
 342                        goto err2;
 343                }
 344        }
 345
 346        *(short *)(master->dev_addr) = dlci->dlci;
 347
 348        dlp = netdev_priv(master);
 349        dlp->slave = slave;
 350        dlp->master = master;
 351
 352        flp = netdev_priv(slave);
 353        err = (*flp->assoc)(slave, master);
 354        if (err < 0)
 355                goto err2;
 356
 357        err = register_netdevice(master);
 358        if (err < 0) 
 359                goto err2;
 360
 361        strcpy(dlci->devname, master->name);
 362
 363        list_add(&dlp->list, &dlci_devs);
 364        rtnl_unlock();
 365
 366        return 0;
 367
 368 err2:
 369        rtnl_unlock();
 370        free_netdev(master);
 371 err1:
 372        dev_put(slave);
 373        return err;
 374}
 375
 376static int dlci_del(struct dlci_add *dlci)
 377{
 378        struct dlci_local       *dlp;
 379        struct frad_local       *flp;
 380        struct net_device       *master, *slave;
 381        int                     err;
 382        bool                    found = false;
 383
 384        rtnl_lock();
 385
 386        /* validate slave device */
 387        master = __dev_get_by_name(&init_net, dlci->devname);
 388        if (!master) {
 389                err = -ENODEV;
 390                goto out;
 391        }
 392
 393        list_for_each_entry(dlp, &dlci_devs, list) {
 394                if (dlp->master == master) {
 395                        found = true;
 396                        break;
 397                }
 398        }
 399        if (!found) {
 400                err = -ENODEV;
 401                goto out;
 402        }
 403
 404        if (netif_running(master)) {
 405                err = -EBUSY;
 406                goto out;
 407        }
 408
 409        dlp = netdev_priv(master);
 410        slave = dlp->slave;
 411        flp = netdev_priv(slave);
 412
 413        err = (*flp->deassoc)(slave, master);
 414        if (!err) {
 415                list_del(&dlp->list);
 416
 417                unregister_netdevice(master);
 418
 419                dev_put(slave);
 420        }
 421out:
 422        rtnl_unlock();
 423        return err;
 424}
 425
 426static int dlci_ioctl(unsigned int cmd, void __user *arg)
 427{
 428        struct dlci_add add;
 429        int err;
 430        
 431        if (!capable(CAP_NET_ADMIN))
 432                return -EPERM;
 433
 434        if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
 435                return -EFAULT;
 436
 437        switch (cmd)
 438        {
 439                case SIOCADDDLCI:
 440                        err = dlci_add(&add);
 441
 442                        if (!err)
 443                                if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
 444                                        return -EFAULT;
 445                        break;
 446
 447                case SIOCDELDLCI:
 448                        err = dlci_del(&add);
 449                        break;
 450
 451                default:
 452                        err = -EINVAL;
 453        }
 454
 455        return err;
 456}
 457
 458static const struct header_ops dlci_header_ops = {
 459        .create = dlci_header,
 460};
 461
 462static const struct net_device_ops dlci_netdev_ops = {
 463        .ndo_open       = dlci_open,
 464        .ndo_stop       = dlci_close,
 465        .ndo_do_ioctl   = dlci_dev_ioctl,
 466        .ndo_start_xmit = dlci_transmit,
 467        .ndo_change_mtu = dlci_change_mtu,
 468};
 469
 470static void dlci_setup(struct net_device *dev)
 471{
 472        struct dlci_local *dlp = netdev_priv(dev);
 473
 474        dev->flags              = 0;
 475        dev->header_ops         = &dlci_header_ops;
 476        dev->netdev_ops         = &dlci_netdev_ops;
 477        dev->destructor         = free_netdev;
 478
 479        dlp->receive            = dlci_receive;
 480
 481        dev->type               = ARPHRD_DLCI;
 482        dev->hard_header_len    = sizeof(struct frhdr);
 483        dev->addr_len           = sizeof(short);
 484
 485}
 486
 487/* if slave is unregistering, then cleanup master */
 488static int dlci_dev_event(struct notifier_block *unused,
 489                          unsigned long event, void *ptr)
 490{
 491        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 492
 493        if (dev_net(dev) != &init_net)
 494                return NOTIFY_DONE;
 495
 496        if (event == NETDEV_UNREGISTER) {
 497                struct dlci_local *dlp;
 498
 499                list_for_each_entry(dlp, &dlci_devs, list) {
 500                        if (dlp->slave == dev) {
 501                                list_del(&dlp->list);
 502                                unregister_netdevice(dlp->master);
 503                                dev_put(dlp->slave);
 504                                break;
 505                        }
 506                }
 507        }
 508        return NOTIFY_DONE;
 509}
 510
 511static struct notifier_block dlci_notifier = {
 512        .notifier_call = dlci_dev_event,
 513};
 514
 515static int __init init_dlci(void)
 516{
 517        dlci_ioctl_set(dlci_ioctl);
 518        register_netdevice_notifier(&dlci_notifier);
 519
 520        printk("%s.\n", version);
 521
 522        return 0;
 523}
 524
 525static void __exit dlci_exit(void)
 526{
 527        struct dlci_local       *dlp, *nxt;
 528        
 529        dlci_ioctl_set(NULL);
 530        unregister_netdevice_notifier(&dlci_notifier);
 531
 532        rtnl_lock();
 533        list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 534                unregister_netdevice(dlp->master);
 535                dev_put(dlp->slave);
 536        }
 537        rtnl_unlock();
 538}
 539
 540module_init(init_dlci);
 541module_exit(dlci_exit);
 542
 543MODULE_AUTHOR("Mike McLagan");
 544MODULE_DESCRIPTION("Frame Relay DLCI layer");
 545MODULE_LICENSE("GPL");
 546