xref: /openbmc/linux/drivers/atm/atmtcp.c (revision 9be08a27) 
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 <linux/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 
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 = 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 
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 
113 static void atmtcp_v_dev_close(struct atm_dev *dev)
114 {
115 	/* Nothing.... Isn't this simple :-)  -- REW */
116 }
117 
118 
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 
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 
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 sock *s;
161 	int i;
162 
163 	if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
164 	if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;
165 	if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
166 	if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
167 	if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
168 	    ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
169 	read_lock(&vcc_sklist_lock);
170 	for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
171 		struct hlist_head *head = &vcc_hash[i];
172 
173 		sk_for_each(s, head) {
174 			vcc = atm_sk(s);
175 			if (vcc->dev != dev)
176 				continue;
177 			if ((vcc->vpi >> ci.vpi_bits) ||
178 			    (vcc->vci >> ci.vci_bits)) {
179 				read_unlock(&vcc_sklist_lock);
180 				return -EBUSY;
181 			}
182 		}
183 	}
184 	read_unlock(&vcc_sklist_lock);
185 	dev->ci_range = ci;
186 	return 0;
187 }
188 
189 
190 static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
191 {
192 	struct atmtcp_dev_data *dev_data;
193 	struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */
194 	struct sk_buff *new_skb;
195 	struct atmtcp_hdr *hdr;
196 	int size;
197 
198 	if (vcc->qos.txtp.traffic_class == ATM_NONE) {
199 		if (vcc->pop) vcc->pop(vcc,skb);
200 		else dev_kfree_skb(skb);
201 		return -EINVAL;
202 	}
203 	dev_data = PRIV(vcc->dev);
204 	if (dev_data) out_vcc = dev_data->vcc;
205 	if (!dev_data || !out_vcc) {
206 		if (vcc->pop) vcc->pop(vcc,skb);
207 		else dev_kfree_skb(skb);
208 		if (dev_data) return 0;
209 		atomic_inc(&vcc->stats->tx_err);
210 		return -ENOLINK;
211 	}
212 	size = skb->len+sizeof(struct atmtcp_hdr);
213 	new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
214 	if (!new_skb) {
215 		if (vcc->pop) vcc->pop(vcc,skb);
216 		else dev_kfree_skb(skb);
217 		atomic_inc(&vcc->stats->tx_err);
218 		return -ENOBUFS;
219 	}
220 	hdr = skb_put(new_skb, sizeof(struct atmtcp_hdr));
221 	hdr->vpi = htons(vcc->vpi);
222 	hdr->vci = htons(vcc->vci);
223 	hdr->length = htonl(skb->len);
224 	skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
225 	if (vcc->pop) vcc->pop(vcc,skb);
226 	else dev_kfree_skb(skb);
227 	out_vcc->push(out_vcc,new_skb);
228 	atomic_inc(&vcc->stats->tx);
229 	atomic_inc(&out_vcc->stats->rx);
230 	return 0;
231 }
232 
233 
234 static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
235 {
236 	struct atmtcp_dev_data *dev_data = PRIV(dev);
237 
238 	if (*pos) return 0;
239 	if (!dev_data->persist) return sprintf(page,"ephemeral\n");
240 	return sprintf(page,"persistent, %sconnected\n",
241 	    dev_data->vcc ? "" : "dis");
242 }
243 
244 
245 static void atmtcp_c_close(struct atm_vcc *vcc)
246 {
247 	struct atm_dev *atmtcp_dev;
248 	struct atmtcp_dev_data *dev_data;
249 
250 	atmtcp_dev = (struct atm_dev *) vcc->dev_data;
251 	dev_data = PRIV(atmtcp_dev);
252 	dev_data->vcc = NULL;
253 	if (dev_data->persist) return;
254 	atmtcp_dev->dev_data = NULL;
255 	kfree(dev_data);
256 	atm_dev_deregister(atmtcp_dev);
257 	vcc->dev_data = NULL;
258 	module_put(THIS_MODULE);
259 }
260 
261 
262 static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
263 {
264         struct hlist_head *head;
265         struct atm_vcc *vcc;
266         struct sock *s;
267 
268         head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
269 
270 	sk_for_each(s, head) {
271                 vcc = atm_sk(s);
272                 if (vcc->dev == dev &&
273                     vcc->vci == vci && vcc->vpi == vpi &&
274                     vcc->qos.rxtp.traffic_class != ATM_NONE) {
275                                 return vcc;
276                 }
277         }
278         return NULL;
279 }
280 
281 
282 static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
283 {
284 	struct atm_dev *dev;
285 	struct atmtcp_hdr *hdr;
286 	struct atm_vcc *out_vcc;
287 	struct sk_buff *new_skb;
288 	int result = 0;
289 
290 	if (!skb->len) return 0;
291 	dev = vcc->dev_data;
292 	hdr = (struct atmtcp_hdr *) skb->data;
293 	if (hdr->length == ATMTCP_HDR_MAGIC) {
294 		result = atmtcp_recv_control(
295 		    (struct atmtcp_control *) skb->data);
296 		goto done;
297 	}
298 	read_lock(&vcc_sklist_lock);
299 	out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
300 	read_unlock(&vcc_sklist_lock);
301 	if (!out_vcc) {
302 		result = -EUNATCH;
303 		atomic_inc(&vcc->stats->tx_err);
304 		goto done;
305 	}
306 	skb_pull(skb,sizeof(struct atmtcp_hdr));
307 	new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
308 	if (!new_skb) {
309 		result = -ENOBUFS;
310 		goto done;
311 	}
312 	__net_timestamp(new_skb);
313 	skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
314 	out_vcc->push(out_vcc,new_skb);
315 	atomic_inc(&vcc->stats->tx);
316 	atomic_inc(&out_vcc->stats->rx);
317 done:
318 	if (vcc->pop) vcc->pop(vcc,skb);
319 	else dev_kfree_skb(skb);
320 	return result;
321 }
322 
323 
324 /*
325  * Device operations for the virtual ATM devices created by ATMTCP.
326  */
327 
328 
329 static struct atmdev_ops atmtcp_v_dev_ops = {
330 	.dev_close	= atmtcp_v_dev_close,
331 	.open		= atmtcp_v_open,
332 	.close		= atmtcp_v_close,
333 	.ioctl		= atmtcp_v_ioctl,
334 	.send		= atmtcp_v_send,
335 	.proc_read	= atmtcp_v_proc,
336 	.owner		= THIS_MODULE
337 };
338 
339 
340 /*
341  * Device operations for the ATMTCP control device.
342  */
343 
344 
345 static const struct atmdev_ops atmtcp_c_dev_ops = {
346 	.close		= atmtcp_c_close,
347 	.send		= atmtcp_c_send
348 };
349 
350 
351 static struct atm_dev atmtcp_control_dev = {
352 	.ops		= &atmtcp_c_dev_ops,
353 	.type		= "atmtcp",
354 	.number		= 999,
355 	.lock		= __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
356 };
357 
358 
359 static int atmtcp_create(int itf,int persist,struct atm_dev **result)
360 {
361 	struct atmtcp_dev_data *dev_data;
362 	struct atm_dev *dev;
363 
364 	dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
365 	if (!dev_data)
366 		return -ENOMEM;
367 
368 	dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
369 	if (!dev) {
370 		kfree(dev_data);
371 		return itf == -1 ? -ENOMEM : -EBUSY;
372 	}
373 	dev->ci_range.vpi_bits = MAX_VPI_BITS;
374 	dev->ci_range.vci_bits = MAX_VCI_BITS;
375 	dev->dev_data = dev_data;
376 	PRIV(dev)->vcc = NULL;
377 	PRIV(dev)->persist = persist;
378 	if (result) *result = dev;
379 	return 0;
380 }
381 
382 
383 static int atmtcp_attach(struct atm_vcc *vcc,int itf)
384 {
385 	struct atm_dev *dev;
386 
387 	dev = NULL;
388 	if (itf != -1) dev = atm_dev_lookup(itf);
389 	if (dev) {
390 		if (dev->ops != &atmtcp_v_dev_ops) {
391 			atm_dev_put(dev);
392 			return -EMEDIUMTYPE;
393 		}
394 		if (PRIV(dev)->vcc) {
395 			atm_dev_put(dev);
396 			return -EBUSY;
397 		}
398 	}
399 	else {
400 		int error;
401 
402 		error = atmtcp_create(itf,0,&dev);
403 		if (error) return error;
404 	}
405 	PRIV(dev)->vcc = vcc;
406 	vcc->dev = &atmtcp_control_dev;
407 	vcc_insert_socket(sk_atm(vcc));
408 	set_bit(ATM_VF_META,&vcc->flags);
409 	set_bit(ATM_VF_READY,&vcc->flags);
410 	vcc->dev_data = dev;
411 	(void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
412 	vcc->stats = &atmtcp_control_dev.stats.aal5;
413 	return dev->number;
414 }
415 
416 
417 static int atmtcp_create_persistent(int itf)
418 {
419 	return atmtcp_create(itf,1,NULL);
420 }
421 
422 
423 static int atmtcp_remove_persistent(int itf)
424 {
425 	struct atm_dev *dev;
426 	struct atmtcp_dev_data *dev_data;
427 
428 	dev = atm_dev_lookup(itf);
429 	if (!dev) return -ENODEV;
430 	if (dev->ops != &atmtcp_v_dev_ops) {
431 		atm_dev_put(dev);
432 		return -EMEDIUMTYPE;
433 	}
434 	dev_data = PRIV(dev);
435 	if (!dev_data->persist) return 0;
436 	dev_data->persist = 0;
437 	if (PRIV(dev)->vcc) return 0;
438 	kfree(dev_data);
439 	atm_dev_put(dev);
440 	atm_dev_deregister(dev);
441 	return 0;
442 }
443 
444 static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
445 {
446 	int err = 0;
447 	struct atm_vcc *vcc = ATM_SD(sock);
448 
449 	if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
450 		return -ENOIOCTLCMD;
451 
452 	if (!capable(CAP_NET_ADMIN))
453 		return -EPERM;
454 
455 	switch (cmd) {
456 		case SIOCSIFATMTCP:
457 			err = atmtcp_attach(vcc, (int) arg);
458 			if (err >= 0) {
459 				sock->state = SS_CONNECTED;
460 				__module_get(THIS_MODULE);
461 			}
462 			break;
463 		case ATMTCP_CREATE:
464 			err = atmtcp_create_persistent((int) arg);
465 			break;
466 		case ATMTCP_REMOVE:
467 			err = atmtcp_remove_persistent((int) arg);
468 			break;
469 	}
470 	return err;
471 }
472 
473 static struct atm_ioctl atmtcp_ioctl_ops = {
474 	.owner 	= THIS_MODULE,
475 	.ioctl	= atmtcp_ioctl,
476 };
477 
478 static __init int atmtcp_init(void)
479 {
480 	register_atm_ioctl(&atmtcp_ioctl_ops);
481 	return 0;
482 }
483 
484 
485 static void __exit atmtcp_exit(void)
486 {
487 	deregister_atm_ioctl(&atmtcp_ioctl_ops);
488 }
489 
490 MODULE_LICENSE("GPL");
491 module_init(atmtcp_init);
492 module_exit(atmtcp_exit);
493