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        struct dlci_local       *dlp;
  75        unsigned int            hlen;
  76        char                    *dest;
  77
  78        dlp = netdev_priv(dev);
  79
  80        hdr.control = FRAD_I_UI;
  81        switch (type)
  82        {
  83                case ETH_P_IP:
  84                        hdr.IP_NLPID = FRAD_P_IP;
  85                        hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
  86                        break;
  87
  88                /* feel free to add other types, if necessary */
  89
  90                default:
  91                        hdr.pad = FRAD_P_PADDING;
  92                        hdr.NLPID = FRAD_P_SNAP;
  93                        memset(hdr.OUI, 0, sizeof(hdr.OUI));
  94                        hdr.PID = htons(type);
  95                        hlen = sizeof(hdr);
  96                        break;
  97        }
  98
  99        dest = skb_push(skb, hlen);
 100        if (!dest)
 101                return 0;
 102
 103        memcpy(dest, &hdr, hlen);
 104
 105        return hlen;
 106}
 107
 108static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
 109{
 110        struct dlci_local *dlp;
 111        struct frhdr            *hdr;
 112        int                                     process, header;
 113
 114        dlp = netdev_priv(dev);
 115        if (!pskb_may_pull(skb, sizeof(*hdr))) {
 116                netdev_notice(dev, "invalid data no header\n");
 117                dev->stats.rx_errors++;
 118                kfree_skb(skb);
 119                return;
 120        }
 121
 122        hdr = (struct frhdr *) skb->data;
 123        process = 0;
 124        header = 0;
 125        skb->dev = dev;
 126
 127        if (hdr->control != FRAD_I_UI)
 128        {
 129                netdev_notice(dev, "Invalid header flag 0x%02X\n",
 130                              hdr->control);
 131                dev->stats.rx_errors++;
 132        }
 133        else
 134                switch (hdr->IP_NLPID)
 135                {
 136                        case FRAD_P_PADDING:
 137                                if (hdr->NLPID != FRAD_P_SNAP)
 138                                {
 139                                        netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 140                                                      hdr->NLPID);
 141                                        dev->stats.rx_errors++;
 142                                        break;
 143                                }
 144         
 145                                if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
 146                                {
 147                                        netdev_notice(dev, "Unsupported organizationally unique identifier 0x%02X-%02X-%02X\n",
 148                                                      hdr->OUI[0],
 149                                                      hdr->OUI[1],
 150                                                      hdr->OUI[2]);
 151                                        dev->stats.rx_errors++;
 152                                        break;
 153                                }
 154
 155                                /* at this point, it's an EtherType frame */
 156                                header = sizeof(struct frhdr);
 157                                /* Already in network order ! */
 158                                skb->protocol = hdr->PID;
 159                                process = 1;
 160                                break;
 161
 162                        case FRAD_P_IP:
 163                                header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
 164                                skb->protocol = htons(ETH_P_IP);
 165                                process = 1;
 166                                break;
 167
 168                        case FRAD_P_SNAP:
 169                        case FRAD_P_Q933:
 170                        case FRAD_P_CLNP:
 171                                netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 172                                              hdr->pad);
 173                                dev->stats.rx_errors++;
 174                                break;
 175
 176                        default:
 177                                netdev_notice(dev, "Invalid pad byte 0x%02X\n",
 178                                              hdr->pad);
 179                                dev->stats.rx_errors++;
 180                                break;                          
 181                }
 182
 183        if (process)
 184        {
 185                /* we've set up the protocol, so discard the header */
 186                skb_reset_mac_header(skb);
 187                skb_pull(skb, header);
 188                dev->stats.rx_bytes += skb->len;
 189                netif_rx(skb);
 190                dev->stats.rx_packets++;
 191        }
 192        else
 193                dev_kfree_skb(skb);
 194}
 195
 196static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 197{
 198        struct dlci_local *dlp = netdev_priv(dev);
 199
 200        if (skb)
 201                dlp->slave->netdev_ops->ndo_start_xmit(skb, dlp->slave);
 202        return NETDEV_TX_OK;
 203}
 204
 205static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 206{
 207        struct dlci_conf        config;
 208        struct dlci_local       *dlp;
 209        struct frad_local       *flp;
 210        int                     err;
 211
 212        dlp = netdev_priv(dev);
 213
 214        flp = netdev_priv(dlp->slave);
 215
 216        if (!get)
 217        {
 218                if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 219                        return -EFAULT;
 220                if (config.flags & ~DLCI_VALID_FLAGS)
 221                        return -EINVAL;
 222                memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 223                dlp->configured = 1;
 224        }
 225
 226        err = (*flp->dlci_conf)(dlp->slave, dev, get);
 227        if (err)
 228                return err;
 229
 230        if (get)
 231        {
 232                if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 233                        return -EFAULT;
 234        }
 235
 236        return 0;
 237}
 238
 239static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 240{
 241        struct dlci_local *dlp;
 242
 243        if (!capable(CAP_NET_ADMIN))
 244                return -EPERM;
 245
 246        dlp = netdev_priv(dev);
 247
 248        switch (cmd)
 249        {
 250                case DLCI_GET_SLAVE:
 251                        if (!*(short *)(dev->dev_addr))
 252                                return -EINVAL;
 253
 254                        strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 255                        break;
 256
 257                case DLCI_GET_CONF:
 258                case DLCI_SET_CONF:
 259                        if (!*(short *)(dev->dev_addr))
 260                                return -EINVAL;
 261
 262                        return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
 263                        break;
 264
 265                default: 
 266                        return -EOPNOTSUPP;
 267        }
 268        return 0;
 269}
 270
 271static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 272{
 273        struct dlci_local *dlp = netdev_priv(dev);
 274
 275        return dev_set_mtu(dlp->slave, new_mtu);
 276}
 277
 278static int dlci_open(struct net_device *dev)
 279{
 280        struct dlci_local       *dlp;
 281        struct frad_local       *flp;
 282        int                     err;
 283
 284        dlp = netdev_priv(dev);
 285
 286        if (!*(short *)(dev->dev_addr))
 287                return -EINVAL;
 288
 289        if (!netif_running(dlp->slave))
 290                return -ENOTCONN;
 291
 292        flp = netdev_priv(dlp->slave);
 293        err = (*flp->activate)(dlp->slave, dev);
 294        if (err)
 295                return err;
 296
 297        netif_start_queue(dev);
 298
 299        return 0;
 300}
 301
 302static int dlci_close(struct net_device *dev)
 303{
 304        struct dlci_local       *dlp;
 305        struct frad_local       *flp;
 306        int                     err;
 307
 308        netif_stop_queue(dev);
 309
 310        dlp = netdev_priv(dev);
 311
 312        flp = netdev_priv(dlp->slave);
 313        err = (*flp->deactivate)(dlp->slave, dev);
 314
 315        return 0;
 316}
 317
 318static int dlci_add(struct dlci_add *dlci)
 319{
 320        struct net_device       *master, *slave;
 321        struct dlci_local       *dlp;
 322        struct frad_local       *flp;
 323        int                     err = -EINVAL;
 324
 325
 326        /* validate slave device */
 327        slave = dev_get_by_name(&init_net, dlci->devname);
 328        if (!slave)
 329                return -ENODEV;
 330
 331        if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 332                goto err1;
 333
 334        /* create device name */
 335        master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 336                              dlci_setup);
 337        if (!master) {
 338                err = -ENOMEM;
 339                goto err1;
 340        }
 341
 342        /* make sure same slave not already registered */
 343        rtnl_lock();
 344        list_for_each_entry(dlp, &dlci_devs, list) {
 345                if (dlp->slave == slave) {
 346                        err = -EBUSY;
 347                        goto err2;
 348                }
 349        }
 350
 351        *(short *)(master->dev_addr) = dlci->dlci;
 352
 353        dlp = netdev_priv(master);
 354        dlp->slave = slave;
 355        dlp->master = master;
 356
 357        flp = netdev_priv(slave);
 358        err = (*flp->assoc)(slave, master);
 359        if (err < 0)
 360                goto err2;
 361
 362        err = register_netdevice(master);
 363        if (err < 0) 
 364                goto err2;
 365
 366        strcpy(dlci->devname, master->name);
 367
 368        list_add(&dlp->list, &dlci_devs);
 369        rtnl_unlock();
 370
 371        return 0;
 372
 373 err2:
 374        rtnl_unlock();
 375        free_netdev(master);
 376 err1:
 377        dev_put(slave);
 378        return err;
 379}
 380
 381static int dlci_del(struct dlci_add *dlci)
 382{
 383        struct dlci_local       *dlp;
 384        struct frad_local       *flp;
 385        struct net_device       *master, *slave;
 386        int                     err;
 387        bool                    found = false;
 388
 389        rtnl_lock();
 390
 391        /* validate slave device */
 392        master = __dev_get_by_name(&init_net, dlci->devname);
 393        if (!master) {
 394                err = -ENODEV;
 395                goto out;
 396        }
 397
 398        list_for_each_entry(dlp, &dlci_devs, list) {
 399                if (dlp->master == master) {
 400                        found = true;
 401                        break;
 402                }
 403        }
 404        if (!found) {
 405                err = -ENODEV;
 406                goto out;
 407        }
 408
 409        if (netif_running(master)) {
 410                err = -EBUSY;
 411                goto out;
 412        }
 413
 414        dlp = netdev_priv(master);
 415        slave = dlp->slave;
 416        flp = netdev_priv(slave);
 417
 418        err = (*flp->deassoc)(slave, master);
 419        if (!err) {
 420                list_del(&dlp->list);
 421
 422                unregister_netdevice(master);
 423
 424                dev_put(slave);
 425        }
 426out:
 427        rtnl_unlock();
 428        return err;
 429}
 430
 431static int dlci_ioctl(unsigned int cmd, void __user *arg)
 432{
 433        struct dlci_add add;
 434        int err;
 435        
 436        if (!capable(CAP_NET_ADMIN))
 437                return -EPERM;
 438
 439        if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
 440                return -EFAULT;
 441
 442        switch (cmd)
 443        {
 444                case SIOCADDDLCI:
 445                        err = dlci_add(&add);
 446
 447                        if (!err)
 448                                if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
 449                                        return -EFAULT;
 450                        break;
 451
 452                case SIOCDELDLCI:
 453                        err = dlci_del(&add);
 454                        break;
 455
 456                default:
 457                        err = -EINVAL;
 458        }
 459
 460        return err;
 461}
 462
 463static const struct header_ops dlci_header_ops = {
 464        .create = dlci_header,
 465};
 466
 467static const struct net_device_ops dlci_netdev_ops = {
 468        .ndo_open       = dlci_open,
 469        .ndo_stop       = dlci_close,
 470        .ndo_do_ioctl   = dlci_dev_ioctl,
 471        .ndo_start_xmit = dlci_transmit,
 472        .ndo_change_mtu = dlci_change_mtu,
 473};
 474
 475static void dlci_setup(struct net_device *dev)
 476{
 477        struct dlci_local *dlp = netdev_priv(dev);
 478
 479        dev->flags              = 0;
 480        dev->header_ops         = &dlci_header_ops;
 481        dev->netdev_ops         = &dlci_netdev_ops;
 482        dev->destructor         = free_netdev;
 483
 484        dlp->receive            = dlci_receive;
 485
 486        dev->type               = ARPHRD_DLCI;
 487        dev->hard_header_len    = sizeof(struct frhdr);
 488        dev->addr_len           = sizeof(short);
 489
 490}
 491
 492/* if slave is unregistering, then cleanup master */
 493static int dlci_dev_event(struct notifier_block *unused,
 494                          unsigned long event, void *ptr)
 495{
 496        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 497
 498        if (dev_net(dev) != &init_net)
 499                return NOTIFY_DONE;
 500
 501        if (event == NETDEV_UNREGISTER) {
 502                struct dlci_local *dlp;
 503
 504                list_for_each_entry(dlp, &dlci_devs, list) {
 505                        if (dlp->slave == dev) {
 506                                list_del(&dlp->list);
 507                                unregister_netdevice(dlp->master);
 508                                dev_put(dlp->slave);
 509                                break;
 510                        }
 511                }
 512        }
 513        return NOTIFY_DONE;
 514}
 515
 516static struct notifier_block dlci_notifier = {
 517        .notifier_call = dlci_dev_event,
 518};
 519
 520static int __init init_dlci(void)
 521{
 522        dlci_ioctl_set(dlci_ioctl);
 523        register_netdevice_notifier(&dlci_notifier);
 524
 525        printk("%s.\n", version);
 526
 527        return 0;
 528}
 529
 530static void __exit dlci_exit(void)
 531{
 532        struct dlci_local       *dlp, *nxt;
 533        
 534        dlci_ioctl_set(NULL);
 535        unregister_netdevice_notifier(&dlci_notifier);
 536
 537        rtnl_lock();
 538        list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 539                unregister_netdevice(dlp->master);
 540                dev_put(dlp->slave);
 541        }
 542        rtnl_unlock();
 543}
 544
 545module_init(init_dlci);
 546module_exit(dlci_exit);
 547
 548MODULE_AUTHOR("Mike McLagan");
 549MODULE_DESCRIPTION("Frame Relay DLCI layer");
 550MODULE_LICENSE("GPL");
 551