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 <asm/uaccess.h>
  12 #include <asm/atomic.h>
  13
  14
  15 extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
  16
  17
  18 #define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
  19
  20
  21 struct atmtcp_dev_data {
  22         struct atm_vcc *vcc;    /* control VCC; NULL if detached */
  23         int persist;            /* non-zero if persistent */
  24 };
  25
  26
  27 #define DEV_LABEL    "atmtcp"
  28
  29 #define MAX_VPI_BITS  8 /* simplifies life */
  30 #define MAX_VCI_BITS 16
  31
  32
  33 /*
  34  * Hairy code ahead: the control VCC may be closed while we're still
  35  * waiting for an answer, so we need to re-validate out_vcc every once
  36  * in a while.
  37  */
  38
  39
  40 static int atmtcp_send_control(struct atm_vcc *vcc,int type,
  41     const struct atmtcp_control *msg,int flag)
  42 {
  43         DECLARE_WAITQUEUE(wait,current);
  44         struct atm_vcc *out_vcc;
  45         struct sk_buff *skb;
  46         struct atmtcp_control *new_msg;
  47         int old_test;
  48         int error = 0;
  49
  50         out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  51         if (!out_vcc) return -EUNATCH;
  52         skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
  53         if (!skb) return -ENOMEM;
  54         mb();
  55         out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  56         if (!out_vcc) {
  57                 dev_kfree_skb(skb);
  58                 return -EUNATCH;
  59         }
  60         atm_force_charge(out_vcc,skb->truesize);
  61         new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
  62         *new_msg = *msg;
  63         new_msg->hdr.length = ATMTCP_HDR_MAGIC;
  64         new_msg->type = type;
  65         memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
  66         *(struct atm_vcc **) &new_msg->vcc = vcc;
  67         old_test = test_bit(flag,&vcc->flags);
  68         out_vcc->push(out_vcc,skb);
  69         add_wait_queue(&vcc->sleep,&wait);
  70         while (test_bit(flag,&vcc->flags) == old_test) {
  71                 mb();
  72                 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  73                 if (!out_vcc) {
  74                         error = -EUNATCH;
  75                         break;
  76                 }
  77                 set_current_state(TASK_UNINTERRUPTIBLE);
  78                 schedule();
  79         }
  80         current->state = TASK_RUNNING;
  81         remove_wait_queue(&vcc->sleep,&wait);
  82         return error;
  83 }
  84
  85
  86 static int atmtcp_recv_control(const struct atmtcp_control *msg)
  87 {
  88         struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
  89
  90         vcc->vpi = msg->addr.sap_addr.vpi;
  91         vcc->vci = msg->addr.sap_addr.vci;
  92         vcc->qos = msg->qos;
  93         vcc->reply = msg->result;
  94         switch (msg->type) {
  95             case ATMTCP_CTRL_OPEN:
  96                 change_bit(ATM_VF_READY,&vcc->flags);
  97                 break;
  98             case ATMTCP_CTRL_CLOSE:
  99                 change_bit(ATM_VF_ADDR,&vcc->flags);
 100                 break;
 101             default:
 102                 printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
 103                     msg->type);
 104                 return -EINVAL;
 105         }
 106         wake_up(&vcc->sleep);
 107         return 0;
 108 }
 109
 110
 111 static void atmtcp_v_dev_close(struct atm_dev *dev)
 112 {
 113         /* Nothing.... Isn't this simple :-)  -- REW */
 114 }
 115
 116
 117 static int atmtcp_v_open(struct atm_vcc *vcc,short vpi,int vci)
 118 {
 119         struct atmtcp_control msg;
 120         int error;
 121
 122         memset(&msg,0,sizeof(msg));
 123         msg.addr.sap_family = AF_ATMPVC;
 124         msg.hdr.vpi = htons(vpi);
 125         msg.addr.sap_addr.vpi = vpi;
 126         msg.hdr.vci = htons(vci);
 127         msg.addr.sap_addr.vci = vci;
 128         error = atm_find_ci(vcc,&msg.addr.sap_addr.vpi,&msg.addr.sap_addr.vci);
 129         if (error) return error;
 130         if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
 131         msg.type = ATMTCP_CTRL_OPEN;
 132         msg.qos = vcc->qos;
 133         set_bit(ATM_VF_ADDR,&vcc->flags);
 134         clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
 135         error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
 136         if (error) return error;
 137         return vcc->reply;
 138 }
 139
 140
 141 static void atmtcp_v_close(struct atm_vcc *vcc)
 142 {
 143         struct atmtcp_control msg;
 144
 145         memset(&msg,0,sizeof(msg));
 146         msg.addr.sap_family = AF_ATMPVC;
 147         msg.addr.sap_addr.vpi = vcc->vpi;
 148         msg.addr.sap_addr.vci = vcc->vci;
 149         clear_bit(ATM_VF_READY,&vcc->flags);
 150         (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
 151 }
 152
 153
 154 static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void *arg)
 155 {
 156         struct atm_cirange ci;
 157         struct atm_vcc *vcc;
 158
 159         if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
 160         if (copy_from_user(&ci,(void *) arg,sizeof(ci))) return -EFAULT;
 161         if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
 162         if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
 163         if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
 164             ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
 165         for (vcc = dev->vccs; vcc; vcc = vcc->next)
 166                 if ((vcc->vpi >> ci.vpi_bits) ||
 167                     (vcc->vci >> ci.vci_bits)) return -EBUSY;
 168         dev->ci_range = ci;
 169         return 0;
 170 }
 171
 172
 173 static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
 174 {
 175         struct atmtcp_dev_data *dev_data;
 176         struct atm_vcc *out_vcc;
 177         struct sk_buff *new_skb;
 178         struct atmtcp_hdr *hdr;
 179         int size;
 180
 181         if (vcc->qos.txtp.traffic_class == ATM_NONE) {
 182                 if (vcc->pop) vcc->pop(vcc,skb);
 183                 else dev_kfree_skb(skb);
 184                 return -EINVAL;
 185         }
 186         dev_data = PRIV(vcc->dev);
 187         if (dev_data) out_vcc = dev_data->vcc;
 188         if (!dev_data || !out_vcc) {
 189                 if (vcc->pop) vcc->pop(vcc,skb);
 190                 else dev_kfree_skb(skb);
 191                 if (dev_data) return 0;
 192                 atomic_inc(&vcc->stats->tx_err);
 193                 return -ENOLINK;
 194         }
 195         size = skb->len+sizeof(struct atmtcp_hdr);
 196         new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
 197         if (!new_skb) {
 198                 if (vcc->pop) vcc->pop(vcc,skb);
 199                 else dev_kfree_skb(skb);
 200                 atomic_inc(&vcc->stats->tx_err);
 201                 return -ENOBUFS;
 202         }
 203         hdr = (void *) skb_put(new_skb,sizeof(struct atmtcp_hdr));
 204         hdr->vpi = htons(vcc->vpi);
 205         hdr->vci = htons(vcc->vci);
 206         hdr->length = htonl(skb->len);
 207         memcpy(skb_put(new_skb,skb->len),skb->data,skb->len);
 208         if (vcc->pop) vcc->pop(vcc,skb);
 209         else dev_kfree_skb(skb);
 210         out_vcc->push(out_vcc,new_skb);
 211         atomic_inc(&vcc->stats->tx);
 212         atomic_inc(&out_vcc->stats->rx);
 213         return 0;
 214 }
 215
 216
 217 static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
 218 {
 219         struct atmtcp_dev_data *dev_data = PRIV(dev);
 220
 221         if (*pos) return 0;
 222         if (!dev_data->persist) return sprintf(page,"ephemeral\n");
 223         return sprintf(page,"persistent, %sconnected\n",
 224             dev_data->vcc ? "" : "dis");
 225 }
 226
 227
 228 static void atmtcp_c_close(struct atm_vcc *vcc)
 229 {
 230         struct atm_dev *atmtcp_dev;
 231         struct atmtcp_dev_data *dev_data;
 232         struct atm_vcc *walk;
 233
 234         atmtcp_dev = (struct atm_dev *) vcc->dev_data;
 235         dev_data = PRIV(atmtcp_dev);
 236         dev_data->vcc = NULL;
 237         if (dev_data->persist) return;
 238         PRIV(atmtcp_dev) = NULL;
 239         kfree(dev_data);
 240         shutdown_atm_dev(atmtcp_dev);
 241         vcc->dev_data = NULL;
 242         for (walk = atmtcp_dev->vccs; walk; walk = walk->next)
 243                 wake_up(&walk->sleep);
 244 }
 245
 246
 247 static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 248 {
 249         struct atm_dev *dev;
 250         struct atmtcp_hdr *hdr;
 251         struct atm_vcc *out_vcc;
 252         struct sk_buff *new_skb;
 253         int result = 0;
 254
 255         if (!skb->len) return 0;
 256         dev = vcc->dev_data;
 257         hdr = (struct atmtcp_hdr *) skb->data;
 258         if (hdr->length == ATMTCP_HDR_MAGIC) {
 259                 result = atmtcp_recv_control(
 260                     (struct atmtcp_control *) skb->data);
 261                 goto done;
 262         }
 263         for (out_vcc = dev->vccs; out_vcc; out_vcc = out_vcc->next)
 264                 if (out_vcc->vpi == ntohs(hdr->vpi) &&
 265                     out_vcc->vci == ntohs(hdr->vci) &&
 266                     out_vcc->qos.rxtp.traffic_class != ATM_NONE)
 267                         break;
 268         if (!out_vcc) {
 269                 atomic_inc(&vcc->stats->tx_err);
 270                 goto done;
 271         }
 272         skb_pull(skb,sizeof(struct atmtcp_hdr));
 273         new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
 274         if (!new_skb) {
 275                 result = -ENOBUFS;
 276                 goto done;
 277         }
 278         new_skb->stamp = xtime;
 279         memcpy(skb_put(new_skb,skb->len),skb->data,skb->len);
 280         out_vcc->push(out_vcc,new_skb);
 281         atomic_inc(&vcc->stats->tx);
 282         atomic_inc(&out_vcc->stats->rx);
 283 done:
 284         if (vcc->pop) vcc->pop(vcc,skb);
 285         else dev_kfree_skb(skb);
 286         return result;
 287 }
 288
 289
 290 /*
 291  * Device operations for the virtual ATM devices created by ATMTCP.
 292  */
 293
 294
 295 static struct atmdev_ops atmtcp_v_dev_ops = {
 296         dev_close:      atmtcp_v_dev_close,
 297         open:           atmtcp_v_open,
 298         close:          atmtcp_v_close,
 299         ioctl:          atmtcp_v_ioctl,
 300         send:           atmtcp_v_send,
 301         proc_read:      atmtcp_v_proc,
 302         owner:          THIS_MODULE
 303 };
 304
 305
 306 /*
 307  * Device operations for the ATMTCP control device.
 308  */
 309
 310
 311 static struct atmdev_ops atmtcp_c_dev_ops = {
 312         close:          atmtcp_c_close,
 313         send:           atmtcp_c_send
 314 };
 315
 316
 317 static struct atm_dev atmtcp_control_dev = {
 318         &atmtcp_c_dev_ops,
 319         NULL,           /* no PHY */
 320         "atmtcp",       /* type */
 321         999,            /* dummy device number */
 322         NULL,NULL,      /* pretend not to have any VCCs */
 323         NULL,NULL,      /* no data */
 324         { 0 },          /* no flags */
 325         NULL,           /* no local address */
 326         { 0 }           /* no ESI, no statistics */
 327 };
 328
 329
 330 static int atmtcp_create(int itf,int persist,struct atm_dev **result)
 331 {
 332         struct atmtcp_dev_data *dev_data;
 333         struct atm_dev *dev;
 334
 335         dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
 336         if (!dev_data)
 337                 return -ENOMEM;
 338
 339         dev = atm_dev_register(DEV_LABEL,&atmtcp_v_dev_ops,itf,NULL);
 340         if (!dev) {
 341                 kfree(dev_data);
 342                 return itf == -1 ? -ENOMEM : -EBUSY;
 343         }
 344         dev->ci_range.vpi_bits = MAX_VPI_BITS;
 345         dev->ci_range.vci_bits = MAX_VCI_BITS;
 346         PRIV(dev) = dev_data;
 347         PRIV(dev)->vcc = NULL;
 348         PRIV(dev)->persist = persist;
 349         if (result) *result = dev;
 350         return 0;
 351 }
 352
 353
 354 int atmtcp_attach(struct atm_vcc *vcc,int itf)
 355 {
 356         struct atm_dev *dev;
 357
 358         dev = NULL;
 359         if (itf != -1) dev = atm_find_dev(itf);
 360         if (dev) {
 361                 if (dev->ops != &atmtcp_v_dev_ops) return -EMEDIUMTYPE;
 362                 if (PRIV(dev)->vcc) return -EBUSY;
 363         }
 364         else {
 365                 int error;
 366
 367                 error = atmtcp_create(itf,0,&dev);
 368                 if (error) return error;
 369         }
 370         PRIV(dev)->vcc = vcc;
 371         bind_vcc(vcc,&atmtcp_control_dev);
 372         set_bit(ATM_VF_META,&vcc->flags);
 373         set_bit(ATM_VF_READY,&vcc->flags);
 374         vcc->dev_data = dev;
 375         (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
 376         vcc->stats = &atmtcp_control_dev.stats.aal5;
 377         return dev->number;
 378 }
 379
 380
 381 int atmtcp_create_persistent(int itf)
 382 {
 383         return atmtcp_create(itf,1,NULL);
 384 }
 385
 386
 387 int atmtcp_remove_persistent(int itf)
 388 {
 389         struct atm_dev *dev;
 390         struct atmtcp_dev_data *dev_data;
 391
 392         dev = atm_find_dev(itf);
 393         if (!dev) return -ENODEV;
 394         if (dev->ops != &atmtcp_v_dev_ops) return -EMEDIUMTYPE;
 395         dev_data = PRIV(dev);
 396         if (!dev_data->persist) return 0;
 397         dev_data->persist = 0;
 398         if (PRIV(dev)->vcc) return 0;
 399         kfree(dev_data);
 400         shutdown_atm_dev(dev);
 401         return 0;
 402 }
 403
 404
 405 #ifdef MODULE
 406
 407 int init_module(void)
 408 {
 409         atm_tcp_ops.attach = atmtcp_attach;
 410         atm_tcp_ops.create_persistent = atmtcp_create_persistent;
 411         atm_tcp_ops.remove_persistent = atmtcp_remove_persistent;
 412         return 0;
 413 }
 414
 415
 416 void cleanup_module(void)
 417 {
 418         atm_tcp_ops.attach = NULL;
 419         atm_tcp_ops.create_persistent = NULL;
 420         atm_tcp_ops.remove_persistent = NULL;
 421 }
 422
 423 #else
 424
 425 struct atm_tcp_ops atm_tcp_ops = {
 426         atmtcp_attach,                  /* attach */
 427         atmtcp_create_persistent,       /* create_persistent */
 428         atmtcp_remove_persistent        /* remove_persistent */
 429 };
 430
 431 #endif