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