drivers/atm/atmtcp.c

   1 /* drivers/atm/atmtcp.c - ATM over TCP "device" driver */
   2
   3 /* Written 1997-1999 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 <asm/uaccess.h>
  11 #include "../../net/atm/protocols.h" /* @@@ fix this */
  12
  13
  14 #define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
  15
  16
  17 struct atmtcp_dev_data {
  18         struct atm_vcc *vcc;    /* control VCC; NULL if detached */
  19         int persist;            /* non-zero if persistent */
  20 };
  21
  22
  23 #define DEV_LABEL    "atmtcp"
  24
  25 #define MAX_VPI_BITS  8 /* simplifies life */
  26 #define MAX_VCI_BITS 16
  27
  28
  29 /*
  30  * Hairy code ahead: the control VCC may be closed while we're still
  31  * waiting for an answer, so we need to re-validate out_vcc every once
  32  * in a while.
  33  */
  34
  35
  36 static int atmtcp_send_control(struct atm_vcc *vcc,int type,
  37     const struct atmtcp_control *msg,unsigned short flag)
  38 {
  39         struct atm_vcc *out_vcc;
  40         struct sk_buff *skb;
  41         struct atmtcp_control *new_msg;
  42         unsigned short old_flags;
  43
  44         out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  45         if (!out_vcc) return -EUNATCH;
  46         skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
  47         if (!skb) return -ENOMEM;
  48         mb();
  49         out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  50         if (!out_vcc) {
  51                 dev_kfree_skb(skb);
  52                 return -EUNATCH;
  53         }
  54         atm_force_charge(out_vcc,skb->truesize);
  55         new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
  56         *new_msg = *msg;
  57         new_msg->hdr.length = ATMTCP_HDR_MAGIC;
  58         new_msg->type = type;
  59         new_msg->vcc = (unsigned long) vcc;
  60         old_flags = vcc->flags;
  61         out_vcc->push(out_vcc,skb);
  62         while (!((vcc->flags ^ old_flags) & flag)) {
  63                 mb();
  64                 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
  65                 if (!out_vcc) return -EUNATCH;
  66                 sleep_on(&vcc->sleep);
  67
  68         }
  69         return 0;
  70 }
  71
  72
  73 static int atmtcp_recv_control(const struct atmtcp_control *msg)
  74 {
  75         struct atm_vcc *vcc = (struct atm_vcc *) msg->vcc;
  76
  77         vcc->vpi = msg->addr.sap_addr.vpi;
  78         vcc->vci = msg->addr.sap_addr.vci;
  79         vcc->qos = msg->qos;
  80         vcc->reply = msg->result;
  81         switch (msg->type) {
  82             case ATMTCP_CTRL_OPEN:
  83                 vcc->flags ^= ATM_VF_READY;
  84                 break;
  85             case ATMTCP_CTRL_CLOSE:
  86                 vcc->flags ^= ATM_VF_ADDR;
  87                 break;
  88             default:
  89                 printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
  90                     msg->type);
  91                 return -EINVAL;
  92         }
  93         wake_up(&vcc->sleep);
  94         return 0;
  95 }
  96
  97
  98 static void atmtcp_v_dev_close(struct atm_dev *dev)
  99 {
 100         MOD_DEC_USE_COUNT;
 101 }
 102
 103
 104 static int atmtcp_v_open(struct atm_vcc *vcc,short vpi,int vci)
 105 {
 106         struct atmtcp_control msg;
 107         int error;
 108
 109         memset(&msg,0,sizeof(msg));
 110         msg.addr.sap_family = AF_ATMPVC;
 111         msg.hdr.vpi = htons(vpi);
 112         msg.addr.sap_addr.vpi = vpi;
 113         msg.hdr.vci = htons(vci);
 114         msg.addr.sap_addr.vci = vci;
 115         error = atm_find_ci(vcc,&msg.addr.sap_addr.vpi,&msg.addr.sap_addr.vci);
 116         if (error) return error;
 117         if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
 118         msg.type = ATMTCP_CTRL_OPEN;
 119         msg.qos = vcc->qos;
 120         vcc->flags |= ATM_VF_ADDR;
 121         vcc->flags &= ~ATM_VF_READY; /* just in case ... */
 122         error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
 123         if (error) return error;
 124         return vcc->reply;
 125 }
 126
 127
 128 static void atmtcp_v_close(struct atm_vcc *vcc)
 129 {
 130         struct atmtcp_control msg;
 131
 132         memset(&msg,0,sizeof(msg));
 133         msg.addr.sap_family = AF_ATMPVC;
 134         msg.addr.sap_addr.vpi = vcc->vpi;
 135         msg.addr.sap_addr.vci = vcc->vci;
 136         vcc->flags &= ~ATM_VF_READY;
 137         (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
 138 }
 139
 140
 141 static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void *arg)
 142 {
 143         struct atm_cirange ci;
 144         struct atm_vcc *vcc;
 145
 146         if (cmd != ATM_SETCIRANGE) return -EINVAL;
 147         if (copy_from_user(&ci,(void *) arg,sizeof(ci))) return -EFAULT;
 148         if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
 149         if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
 150         if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
 151             ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
 152         for (vcc = dev->vccs; vcc; vcc = vcc->next)
 153                 if ((vcc->vpi >> ci.vpi_bits) ||
 154                     (vcc->vci >> ci.vci_bits)) return -EBUSY;
 155         dev->ci_range = ci;
 156         return 0;
 157 }
 158
 159
 160 static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
 161 {
 162         struct atmtcp_dev_data *dev_data;
 163         struct atm_vcc *out_vcc;
 164         struct sk_buff *new_skb;
 165         struct atmtcp_hdr *hdr;
 166         int size;
 167
 168         dev_data = PRIV(vcc->dev);
 169         if (dev_data) out_vcc = dev_data->vcc;
 170         if (!dev_data || !out_vcc) {
 171                 if (vcc->pop) vcc->pop(vcc,skb);
 172                 else dev_kfree_skb(skb);
 173                 if (dev_data) return 0;
 174                 vcc->stats->tx_err++;
 175                 return -ENOLINK;
 176         }
 177         size = skb->len+sizeof(struct atmtcp_hdr);
 178         new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
 179         if (!new_skb) {
 180                 if (vcc->pop) vcc->pop(vcc,skb);
 181                 else dev_kfree_skb(skb);
 182                 vcc->stats->tx_err++;
 183                 return -ENOBUFS;
 184         }
 185         hdr = (void *) skb_put(new_skb,sizeof(struct atmtcp_hdr));
 186         hdr->vpi = htons(vcc->vpi);
 187         hdr->vci = htons(vcc->vci);
 188         hdr->length = htonl(skb->len);
 189         memcpy(skb_put(new_skb,skb->len),skb->data,skb->len);
 190         if (vcc->pop) vcc->pop(vcc,skb);
 191         else dev_kfree_skb(skb);
 192         out_vcc->push(out_vcc,new_skb);
 193         return 0;
 194 }
 195
 196
 197 static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
 198 {
 199         struct atmtcp_dev_data *dev_data = PRIV(dev);
 200
 201         if (*pos) return 0;
 202         if (!dev_data->persist) return sprintf(page,"ephemeral\n");
 203         return sprintf(page,"persistent, %sconnected\n",
 204             dev_data->vcc ? "" : "dis");
 205 }
 206
 207
 208 static void atmtcp_c_close(struct atm_vcc *vcc)
 209 {
 210         struct atm_dev *atmtcp_dev;
 211         struct atmtcp_dev_data *dev_data;
 212         struct atm_vcc *walk;
 213
 214         atmtcp_dev = (struct atm_dev *) vcc->dev_data;
 215         dev_data = PRIV(atmtcp_dev);
 216         dev_data->vcc = NULL;
 217         if (dev_data->persist) return;
 218         PRIV(atmtcp_dev) = NULL;
 219         kfree(dev_data);
 220         shutdown_atm_dev(atmtcp_dev);
 221         vcc->dev_data = NULL;
 222         for (walk = atmtcp_dev->vccs; walk; walk = walk->next)
 223                 wake_up(&walk->sleep);
 224 }
 225
 226
 227 static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
 228 {
 229         struct atm_dev *dev;
 230         struct atmtcp_hdr *hdr;
 231         struct atm_vcc *out_vcc;
 232         struct sk_buff *new_skb;
 233         int result = 0;
 234
 235         if (!skb->len) return 0;
 236         dev = vcc->dev_data;
 237         hdr = (struct atmtcp_hdr *) skb->data;
 238         if (hdr->length == ATMTCP_HDR_MAGIC) {
 239                 result = atmtcp_recv_control(
 240                     (struct atmtcp_control *) skb->data);
 241                 goto done;
 242         }
 243         for (out_vcc = dev->vccs; out_vcc; out_vcc = out_vcc->next)
 244                 if (out_vcc->vpi == ntohs(hdr->vpi) &&
 245                     out_vcc->vci == ntohs(hdr->vci) &&
 246                     out_vcc->qos.rxtp.traffic_class != ATM_NONE)
 247                         break;
 248         if (!out_vcc) {
 249                 vcc->stats->tx_err++;
 250                 goto done;
 251         }
 252         skb_pull(skb,sizeof(struct atmtcp_hdr));
 253         new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
 254         if (!new_skb) {
 255                 result = -ENOBUFS;
 256                 goto done;
 257         }
 258         new_skb->stamp = xtime;
 259         memcpy(skb_put(new_skb,skb->len),skb->data,skb->len);
 260         out_vcc->push(out_vcc,new_skb);
 261 done:
 262         if (vcc->pop) vcc->pop(vcc,skb);
 263         else dev_kfree_skb(skb);
 264         return result;
 265 }
 266
 267
 268 /*
 269  * Device operations for the virtual ATM devices created by ATMTCP.
 270  */
 271
 272
 273 static struct atmdev_ops atmtcp_v_dev_ops = {
 274         atmtcp_v_dev_close,
 275         atmtcp_v_open,
 276         atmtcp_v_close,
 277         atmtcp_v_ioctl,
 278         NULL,           /* no getsockopt */
 279         NULL,           /* no setsockopt */
 280         atmtcp_v_send,
 281         NULL,           /* no direct writes */
 282         NULL,           /* no send_oam */
 283         NULL,           /* no phy_put */
 284         NULL,           /* no phy_get */
 285         NULL,           /* no feedback */
 286         NULL,           /* no change_qos */
 287         NULL,           /* no free_rx_skb */
 288         atmtcp_v_proc   /* proc_read */
 289 };
 290
 291
 292 /*
 293  * Device operations for the ATMTCP control device.
 294  */
 295
 296
 297 static struct atmdev_ops atmtcp_c_dev_ops = {
 298         NULL,           /* no dev_close */
 299         NULL,           /* no open */
 300         atmtcp_c_close,
 301         NULL,           /* no ioctl */
 302         NULL,           /* no getsockopt */
 303         NULL,           /* no setsockopt */
 304         atmtcp_c_send,
 305         NULL,           /* no sg_send */
 306         NULL,           /* no send_oam */
 307         NULL,           /* no phy_put */
 308         NULL,           /* no phy_get */
 309         NULL,           /* no feedback */
 310         NULL,           /* no change_qos */
 311         NULL,           /* no free_rx_skb */
 312         NULL            /* no proc_read */
 313 };
 314
 315
 316 static struct atm_dev atmtcp_control_dev = {
 317         &atmtcp_c_dev_ops,
 318         NULL,           /* no PHY */
 319         "atmtcp",       /* type */
 320         999,            /* dummy device number */
 321         NULL,NULL,      /* pretend not to have any VCCs */
 322         NULL,NULL,      /* no data */
 323         0,              /* no flags */
 324         NULL,           /* no local address */
 325         { 0 }           /* no ESI, no statistics */
 326 };
 327
 328
 329 static int atmtcp_create(int itf,int persist,struct atm_dev **result)
 330 {
 331         struct atmtcp_dev_data *dev_data;
 332         struct atm_dev *dev;
 333
 334         dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
 335         if (!dev_data) return -ENOMEM;
 336         dev = atm_dev_register(DEV_LABEL,&atmtcp_v_dev_ops,itf,0);
 337         if (!dev) {
 338                 kfree(dev_data);
 339                 return itf == -1 ? -ENOMEM : -EBUSY;
 340         }
 341         MOD_INC_USE_COUNT;
 342         dev->ci_range.vpi_bits = MAX_VPI_BITS;
 343         dev->ci_range.vci_bits = MAX_VCI_BITS;
 344         PRIV(dev) = dev_data;
 345         PRIV(dev)->vcc = NULL;
 346         PRIV(dev)->persist = persist;
 347         if (result) *result = dev;
 348         return 0;
 349 }
 350
 351
 352 int atmtcp_attach(struct atm_vcc *vcc,int itf)
 353 {
 354         struct atm_dev *dev;
 355
 356         dev = NULL;
 357         if (itf != -1) dev = atm_find_dev(itf);
 358         if (dev) {
 359                 if (dev->ops != &atmtcp_v_dev_ops) return -EMEDIUMTYPE;
 360                 if (PRIV(dev)->vcc) return -EBUSY;
 361         }
 362         else {
 363                 int error;
 364
 365                 error = atmtcp_create(itf,0,&dev);
 366                 if (error) return error;
 367         }
 368         PRIV(dev)->vcc = vcc;
 369         bind_vcc(vcc,&atmtcp_control_dev);
 370         vcc->flags |= ATM_VF_READY | ATM_VF_META;
 371         vcc->dev_data = dev;
 372         (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
 373         vcc->stats = &atmtcp_control_dev.stats.aal5;
 374         return dev->number;
 375 }
 376
 377
 378 int atmtcp_create_persistent(int itf)
 379 {
 380         return atmtcp_create(itf,1,NULL);
 381 }
 382
 383
 384 int atmtcp_remove_persistent(int itf)
 385 {
 386         struct atm_dev *dev;
 387         struct atmtcp_dev_data *dev_data;
 388
 389         dev = atm_find_dev(itf);
 390         if (!dev) return -ENODEV;
 391         if (dev->ops != &atmtcp_v_dev_ops) return -EMEDIUMTYPE;
 392         dev_data = PRIV(dev);
 393         if (!dev_data->persist) return 0;
 394         dev_data->persist = 0;
 395         if (PRIV(dev)->vcc) return 0;
 396         kfree(dev_data);
 397         shutdown_atm_dev(dev);
 398         return 0;
 399 }
 400
 401
 402 #ifdef MODULE
 403
 404 int init_module(void)
 405 {
 406         atm_tcp_ops.attach = atmtcp_attach;
 407         atm_tcp_ops.create_persistent = atmtcp_create_persistent;
 408         atm_tcp_ops.remove_persistent = atmtcp_remove_persistent;
 409         return 0;
 410 }
 411
 412
 413 void cleanup_module(void)
 414 {
 415         atm_tcp_ops.attach = NULL;
 416         atm_tcp_ops.create_persistent = NULL;
 417         atm_tcp_ops.remove_persistent = NULL;
 418 }
 419
 420 #else
 421
 422 struct atm_tcp_ops atm_tcp_ops = {
 423         atmtcp_attach,                  /* attach */
 424         atmtcp_create_persistent,       /* create_persistent */
 425         atmtcp_remove_persistent        /* remove_persistent */
 426 };
 427
 428 #endif