drivers/atm/atmtcp.c

   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
  18 extern 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
  24 struct 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
  43 static 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
  89 static 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
 114 static void atmtcp_v_dev_close(struct atm_dev *dev)
 115 {
 116         /* Nothing.... Isn't this simple :-)  -- REW */
 117 }
 118
 119
 120 static 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
 144 static 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
 157 static 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
 191 static 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
 235 static 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
 246 static 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
 263 static 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
 283 static 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);
 318 done:
 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
 330 static 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
 346 static const struct atmdev_ops atmtcp_c_dev_ops = {
 347         .close          = atmtcp_c_close,
 348         .send           = atmtcp_c_send
 349 };
 350
 351
 352 static 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
 360 static 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
 384 static 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
 418 static int atmtcp_create_persistent(int itf)
 419 {
 420         return atmtcp_create(itf,1,NULL);
 421 }
 422
 423
 424 static 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
 445 static 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
 474 static struct atm_ioctl atmtcp_ioctl_ops = {
 475         .owner  = THIS_MODULE,
 476         .ioctl  = atmtcp_ioctl,
 477 };
 478
 479 static __init int atmtcp_init(void)
 480 {
 481         register_atm_ioctl(&atmtcp_ioctl_ops);
 482         return 0;
 483 }
 484
 485
 486 static void __exit atmtcp_exit(void)
 487 {
 488         deregister_atm_ioctl(&atmtcp_ioctl_ops);
 489 }
 490
 491 MODULE_LICENSE("GPL");
 492 module_init(atmtcp_init);
 493 module_exit(atmtcp_exit);