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 const 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) { 437 atm_dev_put(dev); 438 return 0; 439 } 440 dev_data->persist = 0; 441 if (PRIV(dev)->vcc) { 442 atm_dev_put(dev); 443 return 0; 444 } 445 kfree(dev_data); 446 atm_dev_put(dev); 447 atm_dev_deregister(dev); 448 return 0; 449 } 450 451 static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 452 { 453 int err = 0; 454 struct atm_vcc *vcc = ATM_SD(sock); 455 456 if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE) 457 return -ENOIOCTLCMD; 458 459 if (!capable(CAP_NET_ADMIN)) 460 return -EPERM; 461 462 switch (cmd) { 463 case SIOCSIFATMTCP: 464 err = atmtcp_attach(vcc, (int) arg); 465 if (err >= 0) { 466 sock->state = SS_CONNECTED; 467 __module_get(THIS_MODULE); 468 } 469 break; 470 case ATMTCP_CREATE: 471 err = atmtcp_create_persistent((int) arg); 472 break; 473 case ATMTCP_REMOVE: 474 err = atmtcp_remove_persistent((int) arg); 475 break; 476 } 477 return err; 478 } 479 480 static struct atm_ioctl atmtcp_ioctl_ops = { 481 .owner = THIS_MODULE, 482 .ioctl = atmtcp_ioctl, 483 }; 484 485 static __init int atmtcp_init(void) 486 { 487 register_atm_ioctl(&atmtcp_ioctl_ops); 488 return 0; 489 } 490 491 492 static void __exit atmtcp_exit(void) 493 { 494 deregister_atm_ioctl(&atmtcp_ioctl_ops); 495 } 496 497 MODULE_DESCRIPTION("ATM over TCP"); 498 MODULE_LICENSE("GPL"); 499 module_init(atmtcp_init); 500 module_exit(atmtcp_exit); 501