aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/atm/atmtcp.c
blob: 480fa6ffbc090a48ae32496ef788c8e63d92e6be (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
/* drivers/atm/atmtcp.c - ATM over TCP "device" driver */

/* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */


#include <linux/module.h>
#include <linux/wait.h>
#include <linux/atmdev.h>
#include <linux/atm_tcp.h>
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/atomic.h>


extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */


#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))


struct atmtcp_dev_data {
	struct atm_vcc *vcc;	/* control VCC; NULL if detached */
	int persist;		/* non-zero if persistent */
};


#define DEV_LABEL    "atmtcp"

#define MAX_VPI_BITS  8	/* simplifies life */
#define MAX_VCI_BITS 16


/*
 * Hairy code ahead: the control VCC may be closed while we're still
 * waiting for an answer, so we need to re-validate out_vcc every once
 * in a while.
 */


static int atmtcp_send_control(struct atm_vcc *vcc,int type,
    const struct atmtcp_control *msg,int flag)
{
	DECLARE_WAITQUEUE(wait,current);
	struct atm_vcc *out_vcc;
	struct sk_buff *skb;
	struct atmtcp_control *new_msg;
	int old_test;
	int error = 0;

	out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
	if (!out_vcc) return -EUNATCH;
	skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
	if (!skb) return -ENOMEM;
	mb();
	out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
	if (!out_vcc) {
		dev_kfree_skb(skb);
		return -EUNATCH;
	}
	atm_force_charge(out_vcc,skb->truesize);
	new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
	*new_msg = *msg;
	new_msg->hdr.length = ATMTCP_HDR_MAGIC;
	new_msg->type = type;
	memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
	*(struct atm_vcc **) &new_msg->vcc = vcc;
	old_test = test_bit(flag,&vcc->flags);
	out_vcc->push(out_vcc,skb);
	add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
	while (test_bit(flag,&vcc->flags) == old_test) {
		mb();
		out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
		if (!out_vcc) {
			error = -EUNATCH;
			break;
		}
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule();
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);
	return error;
}


static int atmtcp_recv_control(const struct atmtcp_control *msg)
{
	struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;

	vcc->vpi = msg->addr.sap_addr.vpi;
	vcc->vci = msg->addr.sap_addr.vci;
	vcc->qos = msg->qos;
	sk_atm(vcc)->sk_err = -msg->result;
	switch (msg->type) {
	    case ATMTCP_CTRL_OPEN:
		change_bit(ATM_VF_READY,&vcc->flags);
		break;
	    case ATMTCP_CTRL_CLOSE:
		change_bit(ATM_VF_ADDR,&vcc->flags);
		break;
	    default:
		printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
		    msg->type);
		return -EINVAL;
	}
	wake_up(sk_sleep(sk_atm(vcc)));
	return 0;
}


static void atmtcp_v_dev_close(struct atm_dev *dev)
{
	/* Nothing.... Isn't this simple :-)  -- REW */
}


static int atmtcp_v_open(struct atm_vcc *vcc)
{
	struct atmtcp_control msg;
	int error;
	short vpi = vcc->vpi;
	int vci = vcc->vci;

	memset(&msg,0,sizeof(msg));
	msg.addr.sap_family = AF_ATMPVC;
	msg.hdr.vpi = htons(vpi);
	msg.addr.sap_addr.vpi = vpi;
	msg.hdr.vci = htons(vci);
	msg.addr.sap_addr.vci = vci;
	if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
	msg.type = ATMTCP_CTRL_OPEN;
	msg.qos = vcc->qos;
	set_bit(ATM_VF_ADDR,&vcc->flags);
	clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
	error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
	if (error) return error;
	return -sk_atm(vcc)->sk_err;
}


static void atmtcp_v_close(struct atm_vcc *vcc)
{
	struct atmtcp_control msg;

	memset(&msg,0,sizeof(msg));
	msg.addr.sap_family = AF_ATMPVC;
	msg.addr.sap_addr.vpi = vcc->vpi;
	msg.addr.sap_addr.vci = vcc->vci;
	clear_bit(ATM_VF_READY,&vcc->flags);
	(void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
}


static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
{
	struct atm_cirange ci;
	struct atm_vcc *vcc;
	struct sock *s;
	int i;

	if (cmd != ATM_SETCIRANGE) return -ENOIOCTLCMD;
	if (copy_from_user(&ci, arg,sizeof(ci))) return -EFAULT;
	if (ci.vpi_bits == ATM_CI_MAX) ci.vpi_bits = MAX_VPI_BITS;
	if (ci.vci_bits == ATM_CI_MAX) ci.vci_bits = MAX_VCI_BITS;
	if (ci.vpi_bits > MAX_VPI_BITS || ci.vpi_bits < 0 ||
	    ci.vci_bits > MAX_VCI_BITS || ci.vci_bits < 0) return -EINVAL;
	read_lock(&vcc_sklist_lock);
	for(i = 0; i < VCC_HTABLE_SIZE; ++i) {
		struct hlist_head *head = &vcc_hash[i];

		sk_for_each(s, head) {
			vcc = atm_sk(s);
			if (vcc->dev != dev)
				continue;
			if ((vcc->vpi >> ci.vpi_bits) ||
			    (vcc->vci >> ci.vci_bits)) {
				read_unlock(&vcc_sklist_lock);
				return -EBUSY;
			}
		}
	}
	read_unlock(&vcc_sklist_lock);
	dev->ci_range = ci;
	return 0;
}


static int atmtcp_v_send(struct atm_vcc *vcc,struct sk_buff *skb)
{
	struct atmtcp_dev_data *dev_data;
	struct atm_vcc *out_vcc=NULL; /* Initializer quietens GCC warning */
	struct sk_buff *new_skb;
	struct atmtcp_hdr *hdr;
	int size;

	if (vcc->qos.txtp.traffic_class == ATM_NONE) {
		if (vcc->pop) vcc->pop(vcc,skb);
		else dev_kfree_skb(skb);
		return -EINVAL;
	}
	dev_data = PRIV(vcc->dev);
	if (dev_data) out_vcc = dev_data->vcc;
	if (!dev_data || !out_vcc) {
		if (vcc->pop) vcc->pop(vcc,skb);
		else dev_kfree_skb(skb);
		if (dev_data) return 0;
		atomic_inc(&vcc->stats->tx_err);
		return -ENOLINK;
	}
	size = skb->len+sizeof(struct atmtcp_hdr);
	new_skb = atm_alloc_charge(out_vcc,size,GFP_ATOMIC);
	if (!new_skb) {
		if (vcc->pop) vcc->pop(vcc,skb);
		else dev_kfree_skb(skb);
		atomic_inc(&vcc->stats->tx_err);
		return -ENOBUFS;
	}
	hdr = (void *) skb_put(new_skb,sizeof(struct atmtcp_hdr));
	hdr->vpi = htons(vcc->vpi);
	hdr->vci = htons(vcc->vci);
	hdr->length = htonl(skb->len);
	skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
	if (vcc->pop) vcc->pop(vcc,skb);
	else dev_kfree_skb(skb);
	out_vcc->push(out_vcc,new_skb);
	atomic_inc(&vcc->stats->tx);
	atomic_inc(&out_vcc->stats->rx);
	return 0;
}


static int atmtcp_v_proc(struct atm_dev *dev,loff_t *pos,char *page)
{
	struct atmtcp_dev_data *dev_data = PRIV(dev);

	if (*pos) return 0;
	if (!dev_data->persist) return sprintf(page,"ephemeral\n");
	return sprintf(page,"persistent, %sconnected\n",
	    dev_data->vcc ? "" : "dis");
}


static void atmtcp_c_close(struct atm_vcc *vcc)
{
	struct atm_dev *atmtcp_dev;
	struct atmtcp_dev_data *dev_data;

	atmtcp_dev = (struct atm_dev *) vcc->dev_data;
	dev_data = PRIV(atmtcp_dev);
	dev_data->vcc = NULL;
	if (dev_data->persist) return;
	atmtcp_dev->dev_data = NULL;
	kfree(dev_data);
	atm_dev_deregister(atmtcp_dev);
	vcc->dev_data = NULL;
	module_put(THIS_MODULE);
}


static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
{
        struct hlist_head *head;
        struct atm_vcc *vcc;
        struct sock *s;

        head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];

	sk_for_each(s, head) {
                vcc = atm_sk(s);
                if (vcc->dev == dev &&
                    vcc->vci == vci && vcc->vpi == vpi &&
                    vcc->qos.rxtp.traffic_class != ATM_NONE) {
                                return vcc;
                }
        }
        return NULL;
}


static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb)
{
	struct atm_dev *dev;
	struct atmtcp_hdr *hdr;
	struct atm_vcc *out_vcc;
	struct sk_buff *new_skb;
	int result = 0;

	if (!skb->len) return 0;
	dev = vcc->dev_data;
	hdr = (struct atmtcp_hdr *) skb->data;
	if (hdr->length == ATMTCP_HDR_MAGIC) {
		result = atmtcp_recv_control(
		    (struct atmtcp_control *) skb->data);
		goto done;
	}
	read_lock(&vcc_sklist_lock);
	out_vcc = find_vcc(dev, ntohs(hdr->vpi), ntohs(hdr->vci));
	read_unlock(&vcc_sklist_lock);
	if (!out_vcc) {
		result = -EUNATCH;
		atomic_inc(&vcc->stats->tx_err);
		goto done;
	}
	skb_pull(skb,sizeof(struct atmtcp_hdr));
	new_skb = atm_alloc_charge(out_vcc,skb->len,GFP_KERNEL);
	if (!new_skb) {
		result = -ENOBUFS;
		goto done;
	}
	__net_timestamp(new_skb);
	skb_copy_from_linear_data(skb, skb_put(new_skb, skb->len), skb->len);
	out_vcc->push(out_vcc,new_skb);
	atomic_inc(&vcc->stats->tx);
	atomic_inc(&out_vcc->stats->rx);
done:
	if (vcc->pop) vcc->pop(vcc,skb);
	else dev_kfree_skb(skb);
	return result;
}


/*
 * Device operations for the virtual ATM devices created by ATMTCP.
 */


static struct atmdev_ops atmtcp_v_dev_ops = {
	.dev_close	= atmtcp_v_dev_close,
	.open		= atmtcp_v_open,
	.close		= atmtcp_v_close,
	.ioctl		= atmtcp_v_ioctl,
	.send		= atmtcp_v_send,
	.proc_read	= atmtcp_v_proc,
	.owner		= THIS_MODULE
};


/*
 * Device operations for the ATMTCP control device.
 */


static struct atmdev_ops atmtcp_c_dev_ops = {
	.close		= atmtcp_c_close,
	.send		= atmtcp_c_send
};


static struct atm_dev atmtcp_control_dev = {
	.ops		= &atmtcp_c_dev_ops,
	.type		= "atmtcp",
	.number		= 999,
	.lock		= __SPIN_LOCK_UNLOCKED(atmtcp_control_dev.lock)
};


static int atmtcp_create(int itf,int persist,struct atm_dev **result)
{
	struct atmtcp_dev_data *dev_data;
	struct atm_dev *dev;

	dev_data = kmalloc(sizeof(*dev_data),GFP_KERNEL);
	if (!dev_data)
		return -ENOMEM;

	dev = atm_dev_register(DEV_LABEL,NULL,&atmtcp_v_dev_ops,itf,NULL);
	if (!dev) {
		kfree(dev_data);
		return itf == -1 ? -ENOMEM : -EBUSY;
	}
	dev->ci_range.vpi_bits = MAX_VPI_BITS;
	dev->ci_range.vci_bits = MAX_VCI_BITS;
	dev->dev_data = dev_data;
	PRIV(dev)->vcc = NULL;
	PRIV(dev)->persist = persist;
	if (result) *result = dev;
	return 0;
}


static int atmtcp_attach(struct atm_vcc *vcc,int itf)
{
	struct atm_dev *dev;

	dev = NULL;
	if (itf != -1) dev = atm_dev_lookup(itf);
	if (dev) {
		if (dev->ops != &atmtcp_v_dev_ops) {
			atm_dev_put(dev);
			return -EMEDIUMTYPE;
		}
		if (PRIV(dev)->vcc) {
			atm_dev_put(dev);
			return -EBUSY;
		}
	}
	else {
		int error;

		error = atmtcp_create(itf,0,&dev);
		if (error) return error;
	}
	PRIV(dev)->vcc = vcc;
	vcc->dev = &atmtcp_control_dev;
	vcc_insert_socket(sk_atm(vcc));
	set_bit(ATM_VF_META,&vcc->flags);
	set_bit(ATM_VF_READY,&vcc->flags);
	vcc->dev_data = dev;
	(void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
	vcc->stats = &atmtcp_control_dev.stats.aal5;
	return dev->number;
}


static int atmtcp_create_persistent(int itf)
{
	return atmtcp_create(itf,1,NULL);
}


static int atmtcp_remove_persistent(int itf)
{
	struct atm_dev *dev;
	struct atmtcp_dev_data *dev_data;

	dev = atm_dev_lookup(itf);
	if (!dev) return -ENODEV;
	if (dev->ops != &atmtcp_v_dev_ops) {
		atm_dev_put(dev);
		return -EMEDIUMTYPE;
	}
	dev_data = PRIV(dev);
	if (!dev_data->persist) return 0;
	dev_data->persist = 0;
	if (PRIV(dev)->vcc) return 0;
	kfree(dev_data);
	atm_dev_put(dev);
	atm_dev_deregister(dev);
	return 0;
}

static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	int err = 0;
	struct atm_vcc *vcc = ATM_SD(sock);

	if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
		return -ENOIOCTLCMD;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	switch (cmd) {
		case SIOCSIFATMTCP:
			err = atmtcp_attach(vcc, (int) arg);
			if (err >= 0) {
				sock->state = SS_CONNECTED;
				__module_get(THIS_MODULE);
			}
			break;
		case ATMTCP_CREATE:
			err = atmtcp_create_persistent((int) arg);
			break;
		case ATMTCP_REMOVE:
			err = atmtcp_remove_persistent((int) arg);
			break;
	}
	return err;
}

static struct atm_ioctl atmtcp_ioctl_ops = {
	.owner 	= THIS_MODULE,
	.ioctl	= atmtcp_ioctl,
};

static __init int atmtcp_init(void)
{
	register_atm_ioctl(&atmtcp_ioctl_ops);
	return 0;
}


static void __exit atmtcp_exit(void)
{
	deregister_atm_ioctl(&atmtcp_ioctl_ops);
}

MODULE_LICENSE("GPL");
module_init(atmtcp_init);
module_exit(atmtcp_exit);