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 sock *s;
 161        int i;
 162
 163        if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
 164        if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;
 165        if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
 166        if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
 167        if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
 168            ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
 169        read_lock(&vcc_sklist_lock);
 170        for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
 171                struct hlist_head *head = &vcc_hash[i];
 172
 173                sk_for_each(s, head) {
 174                        vcc = atm_sk(s);
 175                        if (vcc->dev != dev)
 176                                continue;
 177                        if ((vcc->vpi >> ci.vpi_bits) ||
 178                            (vcc->vci >> ci.vci_bits)) {
 179                                read_unlock(&vcc_sklist_lock);
 180                                return -EBUSY;
 181                        }
 182                }
 183        }
 184        read_unlock(&vcc_sklist_lock);
 185        dev->ci_range = ci;
 186        return 0;
 187}
 188
 189
 190static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
 191{
 192        struct atmtcp_dev_data *dev_data;
 193        struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */
 194        struct sk_buff *new_skb;
 195        struct atmtcp_hdr *hdr;
 196        int size;
 197
 198        if (vcc->qos.txtp.traffic_class == ATM_NONE) {
 199                if (vcc->pop) vcc->pop(vcc,skb);
 200                else dev_kfree_skb(skb);
 201                return -EINVAL;
 202        }
 203        dev_data = PRIV(vcc->dev);
 204        if (dev_data) out_vcc = dev_data->vcc;
 205        if (!dev_data || !out_vcc) {
 206                if (vcc->pop) vcc->pop(vcc,skb);
 207                else dev_kfree_skb(skb);
 208                if (dev_data) return 0;
 209                atomic_inc(&vcc->stats->tx_err);
 210                return -ENOLINK;
 211        }
 212        size = skb->len+sizeof(struct atmtcp_hdr);
 213        new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
 214        if (!new_skb) {
 215                if (vcc->pop) vcc->pop(vcc,skb);
 216                else dev_kfree_skb(skb);
 217                atomic_inc(&vcc->stats->tx_err);
 218                return -ENOBUFS;
 219        }
 220        hdr = (void *) skb_put(new_skb,sizeof(struct atmtcp_hdr));
 221        hdr->vpi = htons(vcc->vpi);
 222        hdr->vci = htons(vcc->vci);
 223        hdr->length = htonl(skb->len);
 224        skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
 225        if (vcc->pop) vcc->pop(vcc,skb);
 226        else dev_kfree_skb(skb);
 227        out_vcc->push(out_vcc,new_skb);
 228        atomic_inc(&vcc->stats->tx);
 229        atomic_inc(&out_vcc->stats->rx);
 230        return 0;
 231}
 232
 233
 234static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
 235{
 236        struct atmtcp_dev_data *dev_data = PRIV(dev);
 237
 238        if (*pos) return 0;
 239        if (!dev_data->persist) return sprintf(page,"ephemeral\n");
 240        return sprintf(page,"persistent, %sconnected\n",
 241            dev_data->vcc ? "" : "dis");
 242}
 243
 244
 245static void atmtcp_c_close(struct atm_vcc *vcc)
 246{
 247        struct atm_dev *atmtcp_dev;
 248        struct atmtcp_dev_data *dev_data;
 249
 250        atmtcp_dev = (struct atm_dev *) vcc->dev_data;
 251        dev_data = PRIV(atmtcp_dev);
 252        dev_data->vcc = NULL;
 253        if (dev_data->persist) return;
 254        atmtcp_dev->dev_data = NULL;
 255        kfree(dev_data);
 256        atm_dev_deregister(atmtcp_dev);
 257        vcc->dev_data = NULL;
 258        module_put(THIS_MODULE);
 259}
 260
 261
 262static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
 263{
 264        struct hlist_head *head;
 265        struct atm_vcc *vcc;
 266        struct sock *s;
 267
 268        head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
 269
 270        sk_for_each(s, head) {
 271                vcc = atm_sk(s);
 272                if (vcc->dev == dev &&
 273                    vcc->vci == vci && vcc->vpi == vpi &&
 274                    vcc->qos.rxtp.traffic_class != ATM_NONE) {
 275                                return vcc;
 276                }
 277        }
 278        return NULL;
 279}
 280
 281
 282static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 283{
 284        struct atm_dev *dev;
 285        struct atmtcp_hdr *hdr;
 286        struct atm_vcc *out_vcc;
 287        struct sk_buff *new_skb;
 288        int result = 0;
 289
 290        if (!skb->len) return 0;
 291        dev = vcc->dev_data;
 292        hdr = (struct atmtcp_hdr *) skb->data;
 293        if (hdr->length == ATMTCP_HDR_MAGIC) {
 294                result = atmtcp_recv_control(
 295                    (struct atmtcp_control *) skb->data);
 296                goto done;
 297        }
 298        read_lock(&vcc_sklist_lock);
 299        out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
 300        read_unlock(&vcc_sklist_lock);
 301        if (!out_vcc) {
 302                atomic_inc(&vcc->stats->tx_err);
 303                goto done;
 304        }
 305        skb_pull(skb,sizeof(struct atmtcp_hdr));
 306        new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
 307        if (!new_skb) {
 308                result = -ENOBUFS;
 309                goto done;
 310        }
 311        __net_timestamp(new_skb);
 312        skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
 313        out_vcc->push(out_vcc,new_skb);
 314        atomic_inc(&vcc->stats->tx);
 315        atomic_inc(&out_vcc->stats->rx);
 316done:
 317        if (vcc->pop) vcc->pop(vcc,skb);
 318        else dev_kfree_skb(skb);
 319        return result;
 320}
 321
 322
 323/*
 324 * Device operations for the virtual ATM devices created by ATMTCP.
 325 */
 326
 327
 328static struct atmdev_ops atmtcp_v_dev_ops = {
 329        .dev_close      = atmtcp_v_dev_close,
 330        .open           = atmtcp_v_open,
 331        .close          = atmtcp_v_close,
 332        .ioctl          = atmtcp_v_ioctl,
 333        .send           = atmtcp_v_send,
 334        .proc_read      = atmtcp_v_proc,
 335        .owner          = THIS_MODULE
 336};
 337
 338
 339/*
 340 * Device operations for the ATMTCP control device.
 341 */
 342
 343
 344static struct atmdev_ops atmtcp_c_dev_ops = {
 345        .close          = atmtcp_c_close,
 346        .send           = atmtcp_c_send
 347};
 348
 349
 350static struct atm_dev atmtcp_control_dev = {
 351        .ops            = &atmtcp_c_dev_ops,
 352        .type           = "atmtcp",
 353        .number         = 999,
 354        .lock           = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
 355};
 356
 357
 358static int atmtcp_create(int itf,int persist,struct atm_dev **result)
 359{
 360        struct atmtcp_dev_data *dev_data;
 361        struct atm_dev *dev;
 362
 363        dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
 364        if (!dev_data)
 365                return -ENOMEM;
 366
 367        dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
 368        if (!dev) {
 369                kfree(dev_data);
 370                return itf == -1 ? -ENOMEM : -EBUSY;
 371        }
 372        dev->ci_range.vpi_bits = MAX_VPI_BITS;
 373        dev->ci_range.vci_bits = MAX_VCI_BITS;
 374        dev->dev_data = dev_data;
 375        PRIV(dev)->vcc = NULL;
 376        PRIV(dev)->persist = persist;
 377        if (result) *result = dev;
 378        return 0;
 379}
 380
 381
 382static int atmtcp_attach(struct atm_vcc *vcc,int itf)
 383{
 384        struct atm_dev *dev;
 385
 386        dev = NULL;
 387        if (itf != -1) dev = atm_dev_lookup(itf);
 388        if (dev) {
 389                if (dev->ops != &atmtcp_v_dev_ops) {
 390                        atm_dev_put(dev);
 391                        return -EMEDIUMTYPE;
 392                }
 393                if (PRIV(dev)->vcc) {
 394                        atm_dev_put(dev);
 395                        return -EBUSY;
 396                }
 397        }
 398        else {
 399                int error;
 400
 401                error = atmtcp_create(itf,0,&dev);
 402                if (error) return error;
 403        }
 404        PRIV(dev)->vcc = vcc;
 405        vcc->dev = &atmtcp_control_dev;
 406        vcc_insert_socket(sk_atm(vcc));
 407        set_bit(ATM_VF_META,&vcc->flags);
 408        set_bit(ATM_VF_READY,&vcc->flags);
 409        vcc->dev_data = dev;
 410        (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
 411        vcc->stats = &atmtcp_control_dev.stats.aal5;
 412        return dev->number;
 413}
 414
 415
 416static int atmtcp_create_persistent(int itf)
 417{
 418        return atmtcp_create(itf,1,NULL);
 419}
 420
 421
 422static int atmtcp_remove_persistent(int itf)
 423{
 424        struct atm_dev *dev;
 425        struct atmtcp_dev_data *dev_data;
 426
 427        dev = atm_dev_lookup(itf);
 428        if (!dev) return -ENODEV;
 429        if (dev->ops != &atmtcp_v_dev_ops) {
 430                atm_dev_put(dev);
 431                return -EMEDIUMTYPE;
 432        }
 433        dev_data = PRIV(dev);
 434        if (!dev_data->persist) return 0;
 435        dev_data->persist = 0;
 436        if (PRIV(dev)->vcc) return 0;
 437        kfree(dev_data);
 438        atm_dev_put(dev);
 439        atm_dev_deregister(dev);
 440        return 0;
 441}
 442
 443static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 444{
 445        int err = 0;
 446        struct atm_vcc *vcc = ATM_SD(sock);
 447
 448        if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
 449                return -ENOIOCTLCMD;
 450
 451        if (!capable(CAP_NET_ADMIN))
 452                return -EPERM;
 453
 454        switch (cmd) {
 455                case SIOCSIFATMTCP:
 456                        err = atmtcp_attach(vcc, (int) arg);
 457                        if (err >= 0) {
 458                                sock->state = SS_CONNECTED;
 459                                __module_get(THIS_MODULE);
 460                        }
 461                        break;
 462                case ATMTCP_CREATE:
 463                        err = atmtcp_create_persistent((int) arg);
 464                        break;
 465                case ATMTCP_REMOVE:
 466                        err = atmtcp_remove_persistent((int) arg);
 467                        break;
 468        }
 469        return err;
 470}
 471
 472static struct atm_ioctl atmtcp_ioctl_ops = {
 473        .owner  = THIS_MODULE,
 474        .ioctl  = atmtcp_ioctl,
 475};
 476
 477static __init int atmtcp_init(void)
 478{
 479        register_atm_ioctl(&atmtcp_ioctl_ops);
 480        return 0;
 481}
 482
 483
 484static void __exit atmtcp_exit(void)
 485{
 486        deregister_atm_ioctl(&atmtcp_ioctl_ops);
 487}
 488
 489MODULE_LICENSE("GPL");
 490module_init(atmtcp_init);
 491module_exit(atmtcp_exit);
 492
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