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
atmtcp_send_control(struct atm_vcc * vcc,int type,const struct atmtcp_control * msg,int flag)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
atmtcp_recv_control(const struct atmtcp_control * msg)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
atmtcp_v_dev_close(struct atm_dev * dev)114 static void atmtcp_v_dev_close(struct atm_dev *dev)
115 {
116 /* Nothing.... Isn't this simple :-) -- REW */
117 }
118
119
atmtcp_v_open(struct atm_vcc * vcc)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
atmtcp_v_close(struct atm_vcc * vcc)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
atmtcp_v_ioctl(struct atm_dev * dev,unsigned int cmd,void __user * arg)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
atmtcp_v_send(struct atm_vcc * vcc,struct sk_buff * skb)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
atmtcp_v_proc(struct atm_dev * dev,loff_t * pos,char * page)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
atmtcp_c_close(struct atm_vcc * vcc)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
find_vcc(struct atm_dev * dev,short vpi,int vci)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
atmtcp_c_send(struct atm_vcc * vcc,struct sk_buff * skb)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 < sizeof(struct atmtcp_hdr))
292 goto done;
293
294 dev = vcc->dev_data;
295 hdr = (struct atmtcp_hdr *) skb->data;
296 if (hdr->length == ATMTCP_HDR_MAGIC) {
297 result = atmtcp_recv_control(
298 (struct atmtcp_control *) skb->data);
299 goto done;
300 }
301 read_lock(&vcc_sklist_lock);
302 out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
303 read_unlock(&vcc_sklist_lock);
304 if (!out_vcc) {
305 result = -EUNATCH;
306 atomic_inc(&vcc->stats->tx_err);
307 goto done;
308 }
309 skb_pull(skb,sizeof(struct atmtcp_hdr));
310 new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
311 if (!new_skb) {
312 result = -ENOBUFS;
313 goto done;
314 }
315 __net_timestamp(new_skb);
316 skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
317 out_vcc->push(out_vcc,new_skb);
318 atomic_inc(&vcc->stats->tx);
319 atomic_inc(&out_vcc->stats->rx);
320 done:
321 if (vcc->pop) vcc->pop(vcc,skb);
322 else dev_kfree_skb(skb);
323 return result;
324 }
325
326
327 /*
328 * Device operations for the virtual ATM devices created by ATMTCP.
329 */
330
331
332 static const struct atmdev_ops atmtcp_v_dev_ops = {
333 .dev_close = atmtcp_v_dev_close,
334 .open = atmtcp_v_open,
335 .close = atmtcp_v_close,
336 .ioctl = atmtcp_v_ioctl,
337 .send = atmtcp_v_send,
338 .proc_read = atmtcp_v_proc,
339 .owner = THIS_MODULE
340 };
341
342
343 /*
344 * Device operations for the ATMTCP control device.
345 */
346
347
348 static const struct atmdev_ops atmtcp_c_dev_ops = {
349 .close = atmtcp_c_close,
350 .send = atmtcp_c_send
351 };
352
353
354 static struct atm_dev atmtcp_control_dev = {
355 .ops = &atmtcp_c_dev_ops,
356 .type = "atmtcp",
357 .number = 999,
358 .lock = __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
359 };
360
361
atmtcp_create(int itf,int persist,struct atm_dev ** result)362 static int atmtcp_create(int itf,int persist,struct atm_dev **result)
363 {
364 struct atmtcp_dev_data *dev_data;
365 struct atm_dev *dev;
366
367 dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
368 if (!dev_data)
369 return -ENOMEM;
370
371 dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
372 if (!dev) {
373 kfree(dev_data);
374 return itf == -1 ? -ENOMEM : -EBUSY;
375 }
376 dev->ci_range.vpi_bits = MAX_VPI_BITS;
377 dev->ci_range.vci_bits = MAX_VCI_BITS;
378 dev->dev_data = dev_data;
379 PRIV(dev)->vcc = NULL;
380 PRIV(dev)->persist = persist;
381 if (result) *result = dev;
382 return 0;
383 }
384
385
atmtcp_attach(struct atm_vcc * vcc,int itf)386 static int atmtcp_attach(struct atm_vcc *vcc,int itf)
387 {
388 struct atm_dev *dev;
389
390 dev = NULL;
391 if (itf != -1) dev = atm_dev_lookup(itf);
392 if (dev) {
393 if (dev->ops != &atmtcp_v_dev_ops) {
394 atm_dev_put(dev);
395 return -EMEDIUMTYPE;
396 }
397 if (PRIV(dev)->vcc) {
398 atm_dev_put(dev);
399 return -EBUSY;
400 }
401 }
402 else {
403 int error;
404
405 error = atmtcp_create(itf,0,&dev);
406 if (error) return error;
407 }
408 PRIV(dev)->vcc = vcc;
409 vcc->dev = &atmtcp_control_dev;
410 vcc_insert_socket(sk_atm(vcc));
411 set_bit(ATM_VF_META,&vcc->flags);
412 set_bit(ATM_VF_READY,&vcc->flags);
413 vcc->dev_data = dev;
414 (void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
415 vcc->stats = &atmtcp_control_dev.stats.aal5;
416 return dev->number;
417 }
418
419
atmtcp_create_persistent(int itf)420 static int atmtcp_create_persistent(int itf)
421 {
422 return atmtcp_create(itf,1,NULL);
423 }
424
425
atmtcp_remove_persistent(int itf)426 static int atmtcp_remove_persistent(int itf)
427 {
428 struct atm_dev *dev;
429 struct atmtcp_dev_data *dev_data;
430
431 dev = atm_dev_lookup(itf);
432 if (!dev) return -ENODEV;
433 if (dev->ops != &atmtcp_v_dev_ops) {
434 atm_dev_put(dev);
435 return -EMEDIUMTYPE;
436 }
437 dev_data = PRIV(dev);
438 if (!dev_data->persist) {
439 atm_dev_put(dev);
440 return 0;
441 }
442 dev_data->persist = 0;
443 if (PRIV(dev)->vcc) {
444 atm_dev_put(dev);
445 return 0;
446 }
447 kfree(dev_data);
448 atm_dev_put(dev);
449 atm_dev_deregister(dev);
450 return 0;
451 }
452
atmtcp_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)453 static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
454 {
455 int err = 0;
456 struct atm_vcc *vcc = ATM_SD(sock);
457
458 if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
459 return -ENOIOCTLCMD;
460
461 if (!capable(CAP_NET_ADMIN))
462 return -EPERM;
463
464 switch (cmd) {
465 case SIOCSIFATMTCP:
466 err = atmtcp_attach(vcc, (int) arg);
467 if (err >= 0) {
468 sock->state = SS_CONNECTED;
469 __module_get(THIS_MODULE);
470 }
471 break;
472 case ATMTCP_CREATE:
473 err = atmtcp_create_persistent((int) arg);
474 break;
475 case ATMTCP_REMOVE:
476 err = atmtcp_remove_persistent((int) arg);
477 break;
478 }
479 return err;
480 }
481
482 static struct atm_ioctl atmtcp_ioctl_ops = {
483 .owner = THIS_MODULE,
484 .ioctl = atmtcp_ioctl,
485 };
486
atmtcp_init(void)487 static __init int atmtcp_init(void)
488 {
489 register_atm_ioctl(&atmtcp_ioctl_ops);
490 return 0;
491 }
492
493
atmtcp_exit(void)494 static void __exit atmtcp_exit(void)
495 {
496 deregister_atm_ioctl(&atmtcp_ioctl_ops);
497 }
498
499 MODULE_DESCRIPTION("ATM over TCP");
500 MODULE_LICENSE("GPL");
501 module_init(atmtcp_init);
502 module_exit(atmtcp_exit);
503