drivers/atm/atmtcp.c

   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
  17 extern 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
  23 struct 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
  42 static 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
  88 static 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
 113 static void atmtcp_v_dev_close(struct atm_dev *dev)
 114 {
 115         /* Nothing.... Isn't this simple :-)  -- REW */
 116 }
 117
 118
 119 static 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
 143 static 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
 156 static 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
 190 static 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
 234 static 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
 245 static 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
 262 static 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
 282 static 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                 result = -EUNATCH;
 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);
 317 done:
 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
 329 static 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
 345 static struct atmdev_ops atmtcp_c_dev_ops = {
 346         .close          = atmtcp_c_close,
 347         .send           = atmtcp_c_send
 348 };
 349
 350
 351 static 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
 359 static 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,NULL,&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
 383 static 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) {
 395                         atm_dev_put(dev);
 396                         return -EBUSY;
 397                 }
 398         }
 399         else {
 400                 int error;
 401
 402                 error = atmtcp_create(itf,0,&dev);
 403                 if (error) return error;
 404         }
 405         PRIV(dev)->vcc = vcc;
 406         vcc->dev = &atmtcp_control_dev;
 407         vcc_insert_socket(sk_atm(vcc));
 408         set_bit(ATM_VF_META,&vcc->flags);
 409         set_bit(ATM_VF_READY,&vcc->flags);
 410         vcc->dev_data = dev;
 411         (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
 412         vcc->stats = &atmtcp_control_dev.stats.aal5;
 413         return dev->number;
 414 }
 415
 416
 417 static int atmtcp_create_persistent(int itf)
 418 {
 419         return atmtcp_create(itf,1,NULL);
 420 }
 421
 422
 423 static int atmtcp_remove_persistent(int itf)
 424 {
 425         struct atm_dev *dev;
 426         struct atmtcp_dev_data *dev_data;
 427
 428         dev = atm_dev_lookup(itf);
 429         if (!dev) return -ENODEV;
 430         if (dev->ops != &atmtcp_v_dev_ops) {
 431                 atm_dev_put(dev);
 432                 return -EMEDIUMTYPE;
 433         }
 434         dev_data = PRIV(dev);
 435         if (!dev_data->persist) return 0;
 436         dev_data->persist = 0;
 437         if (PRIV(dev)->vcc) return 0;
 438         kfree(dev_data);
 439         atm_dev_put(dev);
 440         atm_dev_deregister(dev);
 441         return 0;
 442 }
 443
 444 static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 445 {
 446         int err = 0;
 447         struct atm_vcc *vcc = ATM_SD(sock);
 448
 449         if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
 450                 return -ENOIOCTLCMD;
 451
 452         if (!capable(CAP_NET_ADMIN))
 453                 return -EPERM;
 454
 455         switch (cmd) {
 456                 case SIOCSIFATMTCP:
 457                         err = atmtcp_attach(vcc, (int) arg);
 458                         if (err >= 0) {
 459                                 sock->state = SS_CONNECTED;
 460                                 __module_get(THIS_MODULE);
 461                         }
 462                         break;
 463                 case ATMTCP_CREATE:
 464                         err = atmtcp_create_persistent((int) arg);
 465                         break;
 466                 case ATMTCP_REMOVE:
 467                         err = atmtcp_remove_persistent((int) arg);
 468                         break;
 469         }
 470         return err;
 471 }
 472
 473 static struct atm_ioctl atmtcp_ioctl_ops = {
 474         .owner  = THIS_MODULE,
 475         .ioctl  = atmtcp_ioctl,
 476 };
 477
 478 static __init int atmtcp_init(void)
 479 {
 480         register_atm_ioctl(&atmtcp_ioctl_ops);
 481         return 0;
 482 }
 483
 484
 485 static void __exit atmtcp_exit(void)
 486 {
 487         deregister_atm_ioctl(&atmtcp_ioctl_ops);
 488 }
 489
 490 MODULE_LICENSE("GPL");
 491 module_init(atmtcp_init);
 492 module_exit(atmtcp_exit);