linux/drivers/atm/atmtcp.c
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   1/* drivers/atm/atmtcp.c - ATM over TCP "device" driver */
   2
   3/* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */
   4
   5
   6#include <linux/module.h>
   7#include <linux/wait.h>
   8#include <linux/atmdev.h>
   9#include <linux/atm_tcp.h>
  10#include <linux/bitops.h>
  11#include <linux/init.h>
  12#include <linux/slab.h>
  13#include <asm/uaccess.h>
  14#include <linux/atomic.h>
  15
  16
  17extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
  18
  19
  20#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
  21
  22
  23struct atmtcp_dev_data {
  24        struct atm_vcc *vcc;    /* control VCC; NULL if detached */
  25        int persist;            /* non-zero if persistent */
  26};
  27
  28
  29#define DEV_LABEL    "atmtcp"
  30
  31#define MAX_VPI_BITS  8 /* simplifies life */
  32#define MAX_VCI_BITS 16
  33
  34
  35/*
  36 * Hairy code ahead: the control VCC may be closed while we're still
  37 * waiting for an answer, so we need to re-validate out_vcc every once
  38 * in a while.
  39 */
  40
  41
  42static int atmtcp_send_control(struct atm_vcc *vcc,int type,
  43    const struct atmtcp_control *msg,int flag)
  44{
  45        DECLARE_WAITQUEUE(wait,current);
  46        struct atm_vcc *out_vcc;
  47        struct sk_buff *skb;
  48        struct atmtcp_control *new_msg;
  49        int old_test;
  50        int error = 0;
  51
  52        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  53        if (!out_vcc) return -EUNATCH;
  54        skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
  55        if (!skb) return -ENOMEM;
  56        mb();
  57        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  58        if (!out_vcc) {
  59                dev_kfree_skb(skb);
  60                return -EUNATCH;
  61        }
  62        atm_force_charge(out_vcc,skb->truesize);
  63        new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
  64        *new_msg = *msg;
  65        new_msg->hdr.length = ATMTCP_HDR_MAGIC;
  66        new_msg->type = type;
  67        memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
  68        *(struct atm_vcc **) &new_msg->vcc = vcc;
  69        old_test = test_bit(flag,&vcc->flags);
  70        out_vcc->push(out_vcc,skb);
  71        add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
  72        while (test_bit(flag,&vcc->flags) == old_test) {
  73                mb();
  74                out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  75                if (!out_vcc) {
  76                        error = -EUNATCH;
  77                        break;
  78                }
  79                set_current_state(TASK_UNINTERRUPTIBLE);
  80                schedule();
  81        }
  82        set_current_state(TASK_RUNNING);
  83        remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
  84        return error;
  85}
  86
  87
  88static int atmtcp_recv_control(const struct atmtcp_control *msg)
  89{
  90        struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
  91
  92        vcc->vpi = msg->addr.sap_addr.vpi;
  93        vcc->vci = msg->addr.sap_addr.vci;
  94        vcc->qos = msg->qos;
  95        sk_atm(vcc)->sk_err = -msg->result;
  96        switch (msg->type) {
  97            case ATMTCP_CTRL_OPEN:
  98                change_bit(ATM_VF_READY,&vcc->flags);
  99                break;
 100            case ATMTCP_CTRL_CLOSE:
 101                change_bit(ATM_VF_ADDR,&vcc->flags);
 102                break;
 103            default:
 104                printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
 105                    msg->type);
 106                return -EINVAL;
 107        }
 108        wake_up(sk_sleep(sk_atm(vcc)));
 109        return 0;
 110}
 111
 112
 113static void atmtcp_v_dev_close(struct atm_dev *dev)
 114{
 115        /* Nothing.... Isn't this simple :-)  -- REW */
 116}
 117
 118
 119static int atmtcp_v_open(struct atm_vcc *vcc)
 120{
 121        struct atmtcp_control msg;
 122        int error;
 123        short vpi = vcc->vpi;
 124        int vci = vcc->vci;
 125
 126        memset(&msg,0,sizeof(msg));
 127        msg.addr.sap_family = AF_ATMPVC;
 128        msg.hdr.vpi = htons(vpi);
 129        msg.addr.sap_addr.vpi = vpi;
 130        msg.hdr.vci = htons(vci);
 131        msg.addr.sap_addr.vci = vci;
 132        if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
 133        msg.type = ATMTCP_CTRL_OPEN;
 134        msg.qos = vcc->qos;
 135        set_bit(ATM_VF_ADDR,&vcc->flags);
 136        clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
 137        error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
 138        if (error) return error;
 139        return -sk_atm(vcc)->sk_err;
 140}
 141
 142
 143static void atmtcp_v_close(struct atm_vcc *vcc)
 144{
 145        struct atmtcp_control msg;
 146
 147        memset(&msg,0,sizeof(msg));
 148        msg.addr.sap_family = AF_ATMPVC;
 149        msg.addr.sap_addr.vpi = vcc->vpi;
 150        msg.addr.sap_addr.vci = vcc->vci;
 151        clear_bit(ATM_VF_READY,&vcc->flags);
 152        (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
 153}
 154
 155
 156static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
 157{
 158        struct atm_cirange ci;
 159        struct atm_vcc *vcc;
 160        struct hlist_node *node;
 161        struct sock *s;
 162        int i;
 163
 164        if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
 165        if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;
 166        if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
 167        if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
 168        if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
 169            ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
 170        read_lock(&vcc_sklist_lock);
 171        for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
 172                struct hlist_head *head = &vcc_hash[i];
 173
 174                sk_for_each(s, node, head) {
 175                        vcc = atm_sk(s);
 176                        if (vcc->dev != dev)
 177                                continue;
 178                        if ((vcc->vpi >> ci.vpi_bits) ||
 179                            (vcc->vci >> ci.vci_bits)) {
 180                                read_unlock(&vcc_sklist_lock);
 181                                return -EBUSY;
 182                        }
 183                }
 184        }
 185        read_unlock(&vcc_sklist_lock);
 186        dev->ci_range = ci;
 187        return 0;
 188}
 189
 190
 191static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
 192{
 193        struct atmtcp_dev_data *dev_data;
 194        struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */
 195        struct sk_buff *new_skb;
 196        struct atmtcp_hdr *hdr;
 197        int size;
 198
 199        if (vcc->qos.txtp.traffic_class == ATM_NONE) {
 200                if (vcc->pop) vcc->pop(vcc,skb);
 201                else dev_kfree_skb(skb);
 202                return -EINVAL;
 203        }
 204        dev_data = PRIV(vcc->dev);
 205        if (dev_data) out_vcc = dev_data->vcc;
 206        if (!dev_data || !out_vcc) {
 207                if (vcc->pop) vcc->pop(vcc,skb);
 208                else dev_kfree_skb(skb);
 209                if (dev_data) return 0;
 210                atomic_inc(&vcc->stats->tx_err);
 211                return -ENOLINK;
 212        }
 213        size = skb->len+sizeof(struct atmtcp_hdr);
 214        new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
 215        if (!new_skb) {
 216                if (vcc->pop) vcc->pop(vcc,skb);
 217                else dev_kfree_skb(skb);
 218                atomic_inc(&vcc->stats->tx_err);
 219                return -ENOBUFS;
 220        }
 221        hdr = (void *) skb_put(new_skb,sizeof(struct atmtcp_hdr));
 222        hdr->vpi = htons(vcc->vpi);
 223        hdr->vci = htons(vcc->vci);
 224        hdr->length = htonl(skb->len);
 225        skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
 226        if (vcc->pop) vcc->pop(vcc,skb);
 227        else dev_kfree_skb(skb);
 228        out_vcc->push(out_vcc,new_skb);
 229        atomic_inc(&vcc->stats->tx);
 230        atomic_inc(&out_vcc->stats->rx);
 231        return 0;
 232}
 233
 234
 235static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
 236{
 237        struct atmtcp_dev_data *dev_data = PRIV(dev);
 238
 239        if (*pos) return 0;
 240        if (!dev_data->persist) return sprintf(page,"ephemeral\n");
 241        return sprintf(page,"persistent, %sconnected\n",
 242            dev_data->vcc ? "" : "dis");
 243}
 244
 245
 246static void atmtcp_c_close(struct atm_vcc *vcc)
 247{
 248        struct atm_dev *atmtcp_dev;
 249        struct atmtcp_dev_data *dev_data;
 250
 251        atmtcp_dev = (struct atm_dev *) vcc->dev_data;
 252        dev_data = PRIV(atmtcp_dev);
 253        dev_data->vcc = NULL;
 254        if (dev_data->persist) return;
 255        atmtcp_dev->dev_data = NULL;
 256        kfree(dev_data);
 257        atm_dev_deregister(atmtcp_dev);
 258        vcc->dev_data = NULL;
 259        module_put(THIS_MODULE);
 260}
 261
 262
 263static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
 264{
 265        struct hlist_head *head;
 266        struct atm_vcc *vcc;
 267        struct hlist_node *node;
 268        struct sock *s;
 269
 270        head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
 271
 272        sk_for_each(s, node, head) {
 273                vcc = atm_sk(s);
 274                if (vcc->dev == dev &&
 275                    vcc->vci == vci && vcc->vpi == vpi &&
 276                    vcc->qos.rxtp.traffic_class != ATM_NONE) {
 277                                return vcc;
 278                }
 279        }
 280        return NULL;
 281}
 282
 283
 284static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 285{
 286        struct atm_dev *dev;
 287        struct atmtcp_hdr *hdr;
 288        struct atm_vcc *out_vcc;
 289        struct sk_buff *new_skb;
 290        int result = 0;
 291
 292        if (!skb->len) return 0;
 293        dev = vcc->dev_data;
 294        hdr = (struct atmtcp_hdr *) skb->data;
 295        if (hdr->length == ATMTCP_HDR_MAGIC) {
 296                result = atmtcp_recv_control(
 297                    (struct atmtcp_control *) skb->data);
 298                goto done;
 299        }
 300        read_lock(&vcc_sklist_lock);
 301        out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
 302        read_unlock(&vcc_sklist_lock);
 303        if (!out_vcc) {
 304                atomic_inc(&vcc->stats->tx_err);
 305                goto done;
 306        }
 307        skb_pull(skb,sizeof(struct atmtcp_hdr));
 308        new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
 309        if (!new_skb) {
 310                result = -ENOBUFS;
 311                goto done;
 312        }
 313        __net_timestamp(new_skb);
 314        skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
 315        out_vcc->push(out_vcc,new_skb);
 316        atomic_inc(&vcc->stats->tx);
 317        atomic_inc(&out_vcc->stats->rx);
 318done:
 319        if (vcc->pop) vcc->pop(vcc,skb);
 320        else dev_kfree_skb(skb);
 321        return result;
 322}
 323
 324
 325/*
 326 * Device operations for the virtual ATM devices created by ATMTCP.
 327 */
 328
 329
 330static struct atmdev_ops atmtcp_v_dev_ops = {
 331        .dev_close      = atmtcp_v_dev_close,
 332        .open           = atmtcp_v_open,
 333        .close          = atmtcp_v_close,
 334        .ioctl          = atmtcp_v_ioctl,
 335        .send           = atmtcp_v_send,
 336        .proc_read      = atmtcp_v_proc,
 337        .owner          = THIS_MODULE
 338};
 339
 340
 341/*
 342 * Device operations for the ATMTCP control device.
 343 */
 344
 345
 346static struct atmdev_ops atmtcp_c_dev_ops = {
 347        .close          = atmtcp_c_close,
 348        .send           = atmtcp_c_send
 349};
 350
 351
 352static struct atm_dev atmtcp_control_dev = {
 353        .ops            = &atmtcp_c_dev_ops,
 354        .type           = "atmtcp",
 355        .number         = 999,
 356        .lock           = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
 357};
 358
 359
 360static int atmtcp_create(int itf,int persist,struct atm_dev **result)
 361{
 362        struct atmtcp_dev_data *dev_data;
 363        struct atm_dev *dev;
 364
 365        dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
 366        if (!dev_data)
 367                return -ENOMEM;
 368
 369        dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
 370        if (!dev) {
 371                kfree(dev_data);
 372                return itf == -1 ? -ENOMEM : -EBUSY;
 373        }
 374        dev->ci_range.vpi_bits = MAX_VPI_BITS;
 375        dev->ci_range.vci_bits = MAX_VCI_BITS;
 376        dev->dev_data = dev_data;
 377        PRIV(dev)->vcc = NULL;
 378        PRIV(dev)->persist = persist;
 379        if (result) *result = dev;
 380        return 0;
 381}
 382
 383
 384static int atmtcp_attach(struct atm_vcc *vcc,int itf)
 385{
 386        struct atm_dev *dev;
 387
 388        dev = NULL;
 389        if (itf != -1) dev = atm_dev_lookup(itf);
 390        if (dev) {
 391                if (dev->ops != &atmtcp_v_dev_ops) {
 392                        atm_dev_put(dev);
 393                        return -EMEDIUMTYPE;
 394                }
 395                if (PRIV(dev)->vcc) {
 396                        atm_dev_put(dev);
 397                        return -EBUSY;
 398                }
 399        }
 400        else {
 401                int error;
 402
 403                error = atmtcp_create(itf,0,&dev);
 404                if (error) return error;
 405        }
 406        PRIV(dev)->vcc = vcc;
 407        vcc->dev = &atmtcp_control_dev;
 408        vcc_insert_socket(sk_atm(vcc));
 409        set_bit(ATM_VF_META,&vcc->flags);
 410        set_bit(ATM_VF_READY,&vcc->flags);
 411        vcc->dev_data = dev;
 412        (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
 413        vcc->stats = &atmtcp_control_dev.stats.aal5;
 414        return dev->number;
 415}
 416
 417
 418static int atmtcp_create_persistent(int itf)
 419{
 420        return atmtcp_create(itf,1,NULL);
 421}
 422
 423
 424static int atmtcp_remove_persistent(int itf)
 425{
 426        struct atm_dev *dev;
 427        struct atmtcp_dev_data *dev_data;
 428
 429        dev = atm_dev_lookup(itf);
 430        if (!dev) return -ENODEV;
 431        if (dev->ops != &atmtcp_v_dev_ops) {
 432                atm_dev_put(dev);
 433                return -EMEDIUMTYPE;
 434        }
 435        dev_data = PRIV(dev);
 436        if (!dev_data->persist) return 0;
 437        dev_data->persist = 0;
 438        if (PRIV(dev)->vcc) return 0;
 439        kfree(dev_data);
 440        atm_dev_put(dev);
 441        atm_dev_deregister(dev);
 442        return 0;
 443}
 444
 445static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 446{
 447        int err = 0;
 448        struct atm_vcc *vcc = ATM_SD(sock);
 449
 450        if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
 451                return -ENOIOCTLCMD;
 452
 453        if (!capable(CAP_NET_ADMIN))
 454                return -EPERM;
 455
 456        switch (cmd) {
 457                case SIOCSIFATMTCP:
 458                        err = atmtcp_attach(vcc, (int) arg);
 459                        if (err >= 0) {
 460                                sock->state = SS_CONNECTED;
 461                                __module_get(THIS_MODULE);
 462                        }
 463                        break;
 464                case ATMTCP_CREATE:
 465                        err = atmtcp_create_persistent((int) arg);
 466                        break;
 467                case ATMTCP_REMOVE:
 468                        err = atmtcp_remove_persistent((int) arg);
 469                        break;
 470        }
 471        return err;
 472}
 473
 474static struct atm_ioctl atmtcp_ioctl_ops = {
 475        .owner  = THIS_MODULE,
 476        .ioctl  = atmtcp_ioctl,
 477};
 478
 479static __init int atmtcp_init(void)
 480{
 481        register_atm_ioctl(&atmtcp_ioctl_ops);
 482        return 0;
 483}
 484
 485
 486static void __exit atmtcp_exit(void)
 487{
 488        deregister_atm_ioctl(&atmtcp_ioctl_ops);
 489}
 490
 491MODULE_LICENSE("GPL");
 492module_init(atmtcp_init);
 493module_exit(atmtcp_exit);
 494
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