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 <asm/uaccess.h>
  13#include <asm/atomic.h>
  14
  15
  16extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
  17
  18
  19#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
  20
  21
  22struct atmtcp_dev_data {
  23        struct atm_vcc *vcc;    /* control VCC; NULL if detached */
  24        int persist;            /* non-zero if persistent */
  25};
  26
  27
  28#define DEV_LABEL    "atmtcp"
  29
  30#define MAX_VPI_BITS  8 /* simplifies life */
  31#define MAX_VCI_BITS 16
  32
  33
  34/*
  35 * Hairy code ahead: the control VCC may be closed while we're still
  36 * waiting for an answer, so we need to re-validate out_vcc every once
  37 * in a while.
  38 */
  39
  40
  41static int atmtcp_send_control(struct atm_vcc *vcc,int type,
  42    const struct atmtcp_control *msg,int flag)
  43{
  44        DECLARE_WAITQUEUE(wait,current);
  45        struct atm_vcc *out_vcc;
  46        struct sk_buff *skb;
  47        struct atmtcp_control *new_msg;
  48        int old_test;
  49        int error = 0;
  50
  51        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  52        if (!out_vcc) return -EUNATCH;
  53        skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
  54        if (!skb) return -ENOMEM;
  55        mb();
  56        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  57        if (!out_vcc) {
  58                dev_kfree_skb(skb);
  59                return -EUNATCH;
  60        }
  61        atm_force_charge(out_vcc,skb->truesize);
  62        new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
  63        *new_msg = *msg;
  64        new_msg->hdr.length = ATMTCP_HDR_MAGIC;
  65        new_msg->type = type;
  66        memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
  67        *(struct atm_vcc **) &new_msg->vcc = vcc;
  68        old_test = test_bit(flag,&vcc->flags);
  69        out_vcc->push(out_vcc,skb);
  70        add_wait_queue(sk_atm(vcc)->sk_sleep, &wait);
  71        while (test_bit(flag,&vcc->flags) == old_test) {
  72                mb();
  73                out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  74                if (!out_vcc) {
  75                        error = -EUNATCH;
  76                        break;
  77                }
  78                set_current_state(TASK_UNINTERRUPTIBLE);
  79                schedule();
  80        }
  81        set_current_state(TASK_RUNNING);
  82        remove_wait_queue(sk_atm(vcc)->sk_sleep, &wait);
  83        return error;
  84}
  85
  86
  87static int atmtcp_recv_control(const struct atmtcp_control *msg)
  88{
  89        struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
  90
  91        vcc->vpi = msg->addr.sap_addr.vpi;
  92        vcc->vci = msg->addr.sap_addr.vci;
  93        vcc->qos = msg->qos;
  94        sk_atm(vcc)->sk_err = -msg->result;
  95        switch (msg->type) {
  96            case ATMTCP_CTRL_OPEN:
  97                change_bit(ATM_VF_READY,&vcc->flags);
  98                break;
  99            case ATMTCP_CTRL_CLOSE:
 100                change_bit(ATM_VF_ADDR,&vcc->flags);
 101                break;
 102            default:
 103                printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
 104                    msg->type);
 105                return -EINVAL;
 106        }
 107        wake_up(sk_atm(vcc)->sk_sleep);
 108        return 0;
 109}
 110
 111
 112static void atmtcp_v_dev_close(struct atm_dev *dev)
 113{
 114        /* Nothing.... Isn't this simple :-)  -- REW */
 115}
 116
 117
 118static int atmtcp_v_open(struct atm_vcc *vcc)
 119{
 120        struct atmtcp_control msg;
 121        int error;
 122        short vpi = vcc->vpi;
 123        int vci = vcc->vci;
 124
 125        memset(&msg,0,sizeof(msg));
 126        msg.addr.sap_family = AF_ATMPVC;
 127        msg.hdr.vpi = htons(vpi);
 128        msg.addr.sap_addr.vpi = vpi;
 129        msg.hdr.vci = htons(vci);
 130        msg.addr.sap_addr.vci = vci;
 131        if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
 132        msg.type = ATMTCP_CTRL_OPEN;
 133        msg.qos = vcc->qos;
 134        set_bit(ATM_VF_ADDR,&vcc->flags);
 135        clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
 136        error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
 137        if (error) return error;
 138        return -sk_atm(vcc)->sk_err;
 139}
 140
 141
 142static void atmtcp_v_close(struct atm_vcc *vcc)
 143{
 144        struct atmtcp_control msg;
 145
 146        memset(&msg,0,sizeof(msg));
 147        msg.addr.sap_family = AF_ATMPVC;
 148        msg.addr.sap_addr.vpi = vcc->vpi;
 149        msg.addr.sap_addr.vci = vcc->vci;
 150        clear_bit(ATM_VF_READY,&vcc->flags);
 151        (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
 152}
 153
 154
 155static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
 156{
 157        struct atm_cirange ci;
 158        struct atm_vcc *vcc;
 159        struct hlist_node *node;
 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, node, 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 hlist_node *node;
 267        struct sock *s;
 268
 269        head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
 270
 271        sk_for_each(s, node, head) {
 272                vcc = atm_sk(s);
 273                if (vcc->dev == dev &&
 274                    vcc->vci == vci && vcc->vpi == vpi &&
 275                    vcc->qos.rxtp.traffic_class != ATM_NONE) {
 276                                return vcc;
 277                }
 278        }
 279        return NULL;
 280}
 281
 282
 283static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 284{
 285        struct atm_dev *dev;
 286        struct atmtcp_hdr *hdr;
 287        struct atm_vcc *out_vcc;
 288        struct sk_buff *new_skb;
 289        int result = 0;
 290
 291        if (!skb->len) return 0;
 292        dev = vcc->dev_data;
 293        hdr = (struct atmtcp_hdr *) skb->data;
 294        if (hdr->length == ATMTCP_HDR_MAGIC) {
 295                result = atmtcp_recv_control(
 296                    (struct atmtcp_control *) skb->data);
 297                goto done;
 298        }
 299        read_lock(&vcc_sklist_lock);
 300        out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
 301        read_unlock(&vcc_sklist_lock);
 302        if (!out_vcc) {
 303                atomic_inc(&vcc->stats->tx_err);
 304                goto done;
 305        }
 306        skb_pull(skb,sizeof(struct atmtcp_hdr));
 307        new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
 308        if (!new_skb) {
 309                result = -ENOBUFS;
 310                goto done;
 311        }
 312        __net_timestamp(new_skb);
 313        skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
 314        out_vcc->push(out_vcc,new_skb);
 315        atomic_inc(&vcc->stats->tx);
 316        atomic_inc(&out_vcc->stats->rx);
 317done:
 318        if (vcc->pop) vcc->pop(vcc,skb);
 319        else dev_kfree_skb(skb);
 320        return result;
 321}
 322
 323
 324/*
 325 * Device operations for the virtual ATM devices created by ATMTCP.
 326 */
 327
 328
 329static struct atmdev_ops atmtcp_v_dev_ops = {
 330        .dev_close      = atmtcp_v_dev_close,
 331        .open           = atmtcp_v_open,
 332        .close          = atmtcp_v_close,
 333        .ioctl          = atmtcp_v_ioctl,
 334        .send           = atmtcp_v_send,
 335        .proc_read      = atmtcp_v_proc,
 336        .owner          = THIS_MODULE
 337};
 338
 339
 340/*
 341 * Device operations for the ATMTCP control device.
 342 */
 343
 344
 345static struct atmdev_ops atmtcp_c_dev_ops = {
 346        .close          = atmtcp_c_close,
 347        .send           = atmtcp_c_send
 348};
 349
 350
 351static struct atm_dev atmtcp_control_dev = {
 352        .ops            = &atmtcp_c_dev_ops,
 353        .type           = "atmtcp",
 354        .number         = 999,
 355        .lock           = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
 356};
 357
 358
 359static int atmtcp_create(int itf,int persist,struct atm_dev **result)
 360{
 361        struct atmtcp_dev_data *dev_data;
 362        struct atm_dev *dev;
 363
 364        dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
 365        if (!dev_data)
 366                return -ENOMEM;
 367
 368        dev = atm_dev_register(DEV_LABEL,&atmtcp_v_dev_ops,itf,NULL);
 369        if (!dev) {
 370                kfree(dev_data);
 371                return itf == -1 ? -ENOMEM : -EBUSY;
 372        }
 373        dev->ci_range.vpi_bits = MAX_VPI_BITS;
 374        dev->ci_range.vci_bits = MAX_VCI_BITS;
 375        dev->dev_data = dev_data;
 376        PRIV(dev)->vcc = NULL;
 377        PRIV(dev)->persist = persist;
 378        if (result) *result = dev;
 379        return 0;
 380}
 381
 382
 383static int atmtcp_attach(struct atm_vcc *vcc,int itf)
 384{
 385        struct atm_dev *dev;
 386
 387        dev = NULL;
 388        if (itf != -1) dev = atm_dev_lookup(itf);
 389        if (dev) {
 390                if (dev->ops != &atmtcp_v_dev_ops) {
 391                        atm_dev_put(dev);
 392                        return -EMEDIUMTYPE;
 393                }
 394                if (PRIV(dev)->vcc) return -EBUSY;
 395        }
 396        else {
 397                int error;
 398
 399                error = atmtcp_create(itf,0,&dev);
 400                if (error) return error;
 401        }
 402        PRIV(dev)->vcc = vcc;
 403        vcc->dev = &atmtcp_control_dev;
 404        vcc_insert_socket(sk_atm(vcc));
 405        set_bit(ATM_VF_META,&vcc->flags);
 406        set_bit(ATM_VF_READY,&vcc->flags);
 407        vcc->dev_data = dev;
 408        (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
 409        vcc->stats = &atmtcp_control_dev.stats.aal5;
 410        return dev->number;
 411}
 412
 413
 414static int atmtcp_create_persistent(int itf)
 415{
 416        return atmtcp_create(itf,1,NULL);
 417}
 418
 419
 420static int atmtcp_remove_persistent(int itf)
 421{
 422        struct atm_dev *dev;
 423        struct atmtcp_dev_data *dev_data;
 424
 425        dev = atm_dev_lookup(itf);
 426        if (!dev) return -ENODEV;
 427        if (dev->ops != &atmtcp_v_dev_ops) {
 428                atm_dev_put(dev);
 429                return -EMEDIUMTYPE;
 430        }
 431        dev_data = PRIV(dev);
 432        if (!dev_data->persist) return 0;
 433        dev_data->persist = 0;
 434        if (PRIV(dev)->vcc) return 0;
 435        kfree(dev_data);
 436        atm_dev_put(dev);
 437        atm_dev_deregister(dev);
 438        return 0;
 439}
 440
 441static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 442{
 443        int err = 0;
 444        struct atm_vcc *vcc = ATM_SD(sock);
 445
 446        if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
 447                return -ENOIOCTLCMD;
 448
 449        if (!capable(CAP_NET_ADMIN))
 450                return -EPERM;
 451
 452        switch (cmd) {
 453                case SIOCSIFATMTCP:
 454                        err = atmtcp_attach(vcc, (int) arg);
 455                        if (err >= 0) {
 456                                sock->state = SS_CONNECTED;
 457                                __module_get(THIS_MODULE);
 458                        }
 459                        break;
 460                case ATMTCP_CREATE:
 461                        err = atmtcp_create_persistent((int) arg);
 462                        break;
 463                case ATMTCP_REMOVE:
 464                        err = atmtcp_remove_persistent((int) arg);
 465                        break;
 466        }
 467        return err;
 468}
 469
 470static struct atm_ioctl atmtcp_ioctl_ops = {
 471        .owner  = THIS_MODULE,
 472        .ioctl  = atmtcp_ioctl,
 473};
 474
 475static __init int atmtcp_init(void)
 476{
 477        register_atm_ioctl(&atmtcp_ioctl_ops);
 478        return 0;
 479}
 480
 481
 482static void __exit atmtcp_exit(void)
 483{
 484        deregister_atm_ioctl(&atmtcp_ioctl_ops);
 485}
 486
 487MODULE_LICENSE("GPL");
 488module_init(atmtcp_init);
 489module_exit(atmtcp_exit);
 490