linux/drivers/atm/atmtcp.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/* drivers/atm/atmtcp.c - ATM over TCP "device" driver */
   3
   4/* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */
   5
   6
   7#include <linux/module.h>
   8#include <linux/wait.h>
   9#include <linux/atmdev.h>
  10#include <linux/atm_tcp.h>
  11#include <linux/bitops.h>
  12#include <linux/init.h>
  13#include <linux/slab.h>
  14#include <linux/uaccess.h>
  15#include <linux/atomic.h>
  16
  17
  18extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
  19
  20
  21#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
  22
  23
  24struct atmtcp_dev_data {
  25        struct atm_vcc *vcc;    /* control VCC; NULL if detached */
  26        int persist;            /* non-zero if persistent */
  27};
  28
  29
  30#define DEV_LABEL    "atmtcp"
  31
  32#define MAX_VPI_BITS  8 /* simplifies life */
  33#define MAX_VCI_BITS 16
  34
  35
  36/*
  37 * Hairy code ahead: the control VCC may be closed while we're still
  38 * waiting for an answer, so we need to re-validate out_vcc every once
  39 * in a while.
  40 */
  41
  42
  43static int atmtcp_send_control(struct atm_vcc *vcc,int type,
  44    const struct atmtcp_control *msg,int flag)
  45{
  46        DECLARE_WAITQUEUE(wait,current);
  47        struct atm_vcc *out_vcc;
  48        struct sk_buff *skb;
  49        struct atmtcp_control *new_msg;
  50        int old_test;
  51        int error = 0;
  52
  53        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  54        if (!out_vcc) return -EUNATCH;
  55        skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
  56        if (!skb) return -ENOMEM;
  57        mb();
  58        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  59        if (!out_vcc) {
  60                dev_kfree_skb(skb);
  61                return -EUNATCH;
  62        }
  63        atm_force_charge(out_vcc,skb->truesize);
  64        new_msg = skb_put(skb, sizeof(*new_msg));
  65        *new_msg = *msg;
  66        new_msg->hdr.length = ATMTCP_HDR_MAGIC;
  67        new_msg->type = type;
  68        memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
  69        *(struct atm_vcc **) &new_msg->vcc = vcc;
  70        old_test = test_bit(flag,&vcc->flags);
  71        out_vcc->push(out_vcc,skb);
  72        add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
  73        while (test_bit(flag,&vcc->flags) == old_test) {
  74                mb();
  75                out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  76                if (!out_vcc) {
  77                        error = -EUNATCH;
  78                        break;
  79                }
  80                set_current_state(TASK_UNINTERRUPTIBLE);
  81                schedule();
  82        }
  83        set_current_state(TASK_RUNNING);
  84        remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
  85        return error;
  86}
  87
  88
  89static int atmtcp_recv_control(const struct atmtcp_control *msg)
  90{
  91        struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
  92
  93        vcc->vpi = msg->addr.sap_addr.vpi;
  94        vcc->vci = msg->addr.sap_addr.vci;
  95        vcc->qos = msg->qos;
  96        sk_atm(vcc)->sk_err = -msg->result;
  97        switch (msg->type) {
  98            case ATMTCP_CTRL_OPEN:
  99                change_bit(ATM_VF_READY,&vcc->flags);
 100                break;
 101            case ATMTCP_CTRL_CLOSE:
 102                change_bit(ATM_VF_ADDR,&vcc->flags);
 103                break;
 104            default:
 105                printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
 106                    msg->type);
 107                return -EINVAL;
 108        }
 109        wake_up(sk_sleep(sk_atm(vcc)));
 110        return 0;
 111}
 112
 113
 114static void atmtcp_v_dev_close(struct atm_dev *dev)
 115{
 116        /* Nothing.... Isn't this simple :-)  -- REW */
 117}
 118
 119
 120static int atmtcp_v_open(struct atm_vcc *vcc)
 121{
 122        struct atmtcp_control msg;
 123        int error;
 124        short vpi = vcc->vpi;
 125        int vci = vcc->vci;
 126
 127        memset(&msg,0,sizeof(msg));
 128        msg.addr.sap_family = AF_ATMPVC;
 129        msg.hdr.vpi = htons(vpi);
 130        msg.addr.sap_addr.vpi = vpi;
 131        msg.hdr.vci = htons(vci);
 132        msg.addr.sap_addr.vci = vci;
 133        if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
 134        msg.type = ATMTCP_CTRL_OPEN;
 135        msg.qos = vcc->qos;
 136        set_bit(ATM_VF_ADDR,&vcc->flags);
 137        clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
 138        error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
 139        if (error) return error;
 140        return -sk_atm(vcc)->sk_err;
 141}
 142
 143
 144static void atmtcp_v_close(struct atm_vcc *vcc)
 145{
 146        struct atmtcp_control msg;
 147
 148        memset(&msg,0,sizeof(msg));
 149        msg.addr.sap_family = AF_ATMPVC;
 150        msg.addr.sap_addr.vpi = vcc->vpi;
 151        msg.addr.sap_addr.vci = vcc->vci;
 152        clear_bit(ATM_VF_READY,&vcc->flags);
 153        (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
 154}
 155
 156
 157static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
 158{
 159        struct atm_cirange ci;
 160        struct atm_vcc *vcc;
 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, 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 = 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 sock *s;
 268
 269        head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
 270
 271        sk_for_each(s, 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                result = -EUNATCH;
 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 const 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