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 <linux/init.h>
12 #include <linux/slab.h>
13 #include <asm/uaccess.h>
14 #include <linux/atomic.h>
15
16
17 extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
18
19
20 #define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
21
22
23 struct atmtcp_dev_data {
24 struct atm_vcc *vcc; /* control VCC; NULL if detached */
25 int persist; /* non-zero if persistent */
26 };
27
28
29 #define DEV_LABEL "atmtcp"
30
31 #define MAX_VPI_BITS 8 /* simplifies life */
32 #define MAX_VCI_BITS 16
33
34
35 /*
36 * Hairy code ahead: the control VCC may be closed while we're still
37 * waiting for an answer, so we need to re-validate out_vcc every once
38 * in a while.
39 */
40
41
atmtcp_send_control(struct atm_vcc * vcc,int type,const struct atmtcp_control * msg,int flag)42 static int atmtcp_send_control(struct atm_vcc *vcc,int type,
43 const struct atmtcp_control *msg,int flag)
44 {
45 DECLARE_WAITQUEUE(wait,current);
46 struct atm_vcc *out_vcc;
47 struct sk_buff *skb;
48 struct atmtcp_control *new_msg;
49 int old_test;
50 int error = 0;
51
52 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
53 if (!out_vcc) return -EUNATCH;
54 skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
55 if (!skb) return -ENOMEM;
56 mb();
57 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
58 if (!out_vcc) {
59 dev_kfree_skb(skb);
60 return -EUNATCH;
61 }
62 atm_force_charge(out_vcc,skb->truesize);
63 new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
64 *new_msg = *msg;
65 new_msg->hdr.length = ATMTCP_HDR_MAGIC;
66 new_msg->type = type;
67 memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
68 *(struct atm_vcc **) &new_msg->vcc = vcc;
69 old_test = test_bit(flag,&vcc->flags);
70 out_vcc->push(out_vcc,skb);
71 add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
72 while (test_bit(flag,&vcc->flags) == old_test) {
73 mb();
74 out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
75 if (!out_vcc) {
76 error = -EUNATCH;
77 break;
78 }
79 set_current_state(TASK_UNINTERRUPTIBLE);
80 schedule();
81 }
82 set_current_state(TASK_RUNNING);
83 remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
84 return error;
85 }
86
87
atmtcp_recv_control(const struct atmtcp_control * msg)88 static int atmtcp_recv_control(const struct atmtcp_control *msg)
89 {
90 struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
91
92 vcc->vpi = msg->addr.sap_addr.vpi;
93 vcc->vci = msg->addr.sap_addr.vci;
94 vcc->qos = msg->qos;
95 sk_atm(vcc)->sk_err = -msg->result;
96 switch (msg->type) {
97 case ATMTCP_CTRL_OPEN:
98 change_bit(ATM_VF_READY,&vcc->flags);
99 break;
100 case ATMTCP_CTRL_CLOSE:
101 change_bit(ATM_VF_ADDR,&vcc->flags);
102 break;
103 default:
104 printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
105 msg->type);
106 return -EINVAL;
107 }
108 wake_up(sk_sleep(sk_atm(vcc)));
109 return 0;
110 }
111
112
atmtcp_v_dev_close(struct atm_dev * dev)113 static void atmtcp_v_dev_close(struct atm_dev *dev)
114 {
115 /* Nothing.... Isn't this simple :-) -- REW */
116 }
117
118
atmtcp_v_open(struct atm_vcc * vcc)119 static int atmtcp_v_open(struct atm_vcc *vcc)
120 {
121 struct atmtcp_control msg;
122 int error;
123 short vpi = vcc->vpi;
124 int vci = vcc->vci;
125
126 memset(&msg,0,sizeof(msg));
127 msg.addr.sap_family = AF_ATMPVC;
128 msg.hdr.vpi = htons(vpi);
129 msg.addr.sap_addr.vpi = vpi;
130 msg.hdr.vci = htons(vci);
131 msg.addr.sap_addr.vci = vci;
132 if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
133 msg.type = ATMTCP_CTRL_OPEN;
134 msg.qos = vcc->qos;
135 set_bit(ATM_VF_ADDR,&vcc->flags);
136 clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
137 error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
138 if (error) return error;
139 return -sk_atm(vcc)->sk_err;
140 }
141
142
atmtcp_v_close(struct atm_vcc * vcc)143 static void atmtcp_v_close(struct atm_vcc *vcc)
144 {
145 struct atmtcp_control msg;
146
147 memset(&msg,0,sizeof(msg));
148 msg.addr.sap_family = AF_ATMPVC;
149 msg.addr.sap_addr.vpi = vcc->vpi;
150 msg.addr.sap_addr.vci = vcc->vci;
151 clear_bit(ATM_VF_READY,&vcc->flags);
152 (void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
153 }
154
155
atmtcp_v_ioctl(struct atm_dev * dev,unsigned int cmd,void __user * arg)156 static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
157 {
158 struct atm_cirange ci;
159 struct atm_vcc *vcc;
160 struct hlist_node *node;
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, node, 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 = (void *) 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 hlist_node *node;
268 struct sock *s;
269
270 head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
271
272 sk_for_each(s, node, head) {
273 vcc = atm_sk(s);
274 if (vcc->dev == dev &&
275 vcc->vci == vci && vcc->vpi == vpi &&
276 vcc->qos.rxtp.traffic_class != ATM_NONE) {
277 return vcc;
278 }
279 }
280 return NULL;
281 }
282
283
atmtcp_c_send(struct atm_vcc * vcc,struct sk_buff * skb)284 static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
285 {
286 struct atm_dev *dev;
287 struct atmtcp_hdr *hdr;
288 struct atm_vcc *out_vcc;
289 struct sk_buff *new_skb;
290 int result = 0;
291
292 if (!skb->len) return 0;
293 dev = vcc->dev_data;
294 hdr = (struct atmtcp_hdr *) skb->data;
295 if (hdr->length == ATMTCP_HDR_MAGIC) {
296 result = atmtcp_recv_control(
297 (struct atmtcp_control *) skb->data);
298 goto done;
299 }
300 read_lock(&vcc_sklist_lock);
301 out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
302 read_unlock(&vcc_sklist_lock);
303 if (!out_vcc) {
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 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
atmtcp_create(int itf,int persist,struct atm_dev ** result)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
atmtcp_attach(struct atm_vcc * vcc,int itf)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
atmtcp_create_persistent(int itf)418 static int atmtcp_create_persistent(int itf)
419 {
420 return atmtcp_create(itf,1,NULL);
421 }
422
423
atmtcp_remove_persistent(int itf)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
atmtcp_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)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
atmtcp_init(void)479 static __init int atmtcp_init(void)
480 {
481 register_atm_ioctl(&atmtcp_ioctl_ops);
482 return 0;
483 }
484
485
atmtcp_exit(void)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);
494