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 <asm/uaccess.h>
13#include <asm/atomic.h>
14
15
16extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */
17
18
19#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))
20
21
22struct atmtcp_dev_data {
23	struct atm_vcc *vcc;	/* control VCC; NULL if detached */
24	int persist;		/* non-zero if persistent */
25};
26
27
28#define DEV_LABEL    "atmtcp"
29
30#define MAX_VPI_BITS  8	/* simplifies life */
31#define MAX_VCI_BITS 16
32
33
34/*
35 * Hairy code ahead: the control VCC may be closed while we're still
36 * waiting for an answer, so we need to re-validate out_vcc every once
37 * in a while.
38 */
39
40
41static int atmtcp_send_control(struct atm_vcc *vcc,int type,
42    const struct atmtcp_control *msg,int flag)
43{
44	DECLARE_WAITQUEUE(wait,current);
45	struct atm_vcc *out_vcc;
46	struct sk_buff *skb;
47	struct atmtcp_control *new_msg;
48	int old_test;
49	int error = 0;
50
51	out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
52	if (!out_vcc) return -EUNATCH;
53	skb = alloc_skb(sizeof(*msg),GFP_KERNEL);
54	if (!skb) return -ENOMEM;
55	mb();
56	out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
57	if (!out_vcc) {
58		dev_kfree_skb(skb);
59		return -EUNATCH;
60	}
61	atm_force_charge(out_vcc,skb->truesize);
62	new_msg = (struct atmtcp_control *) skb_put(skb,sizeof(*new_msg));
63	*new_msg = *msg;
64	new_msg->hdr.length = ATMTCP_HDR_MAGIC;
65	new_msg->type = type;
66	memset(&new_msg->vcc,0,sizeof(atm_kptr_t));
67	*(struct atm_vcc **) &new_msg->vcc = vcc;
68	old_test = test_bit(flag,&vcc->flags);
69	out_vcc->push(out_vcc,skb);
70	add_wait_queue(sk_atm(vcc)->sk_sleep, &wait);
71	while (test_bit(flag,&vcc->flags) == old_test) {
72		mb();
73		out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;
74		if (!out_vcc) {
75			error = -EUNATCH;
76			break;
77		}
78		set_current_state(TASK_UNINTERRUPTIBLE);
79		schedule();
80	}
81	set_current_state(TASK_RUNNING);
82	remove_wait_queue(sk_atm(vcc)->sk_sleep, &wait);
83	return error;
84}
85
86
87static int atmtcp_recv_control(const struct atmtcp_control *msg)
88{
89	struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;
90
91	vcc->vpi = msg->addr.sap_addr.vpi;
92	vcc->vci = msg->addr.sap_addr.vci;
93	vcc->qos = msg->qos;
94	sk_atm(vcc)->sk_err = -msg->result;
95	switch (msg->type) {
96	    case ATMTCP_CTRL_OPEN:
97		change_bit(ATM_VF_READY,&vcc->flags);
98		break;
99	    case ATMTCP_CTRL_CLOSE:
100		change_bit(ATM_VF_ADDR,&vcc->flags);
101		break;
102	    default:
103		printk(KERN_ERR "atmtcp_recv_control: unknown type %d\n",
104		    msg->type);
105		return -EINVAL;
106	}
107	wake_up(sk_atm(vcc)->sk_sleep);
108	return 0;
109}
110
111
112static void atmtcp_v_dev_close(struct atm_dev *dev)
113{
114	/* Nothing.... Isn't this simple :-)  -- REW */
115}
116
117
118static int atmtcp_v_open(struct atm_vcc *vcc)
119{
120	struct atmtcp_control msg;
121	int error;
122	short vpi = vcc->vpi;
123	int vci = vcc->vci;
124
125	memset(&msg,0,sizeof(msg));
126	msg.addr.sap_family = AF_ATMPVC;
127	msg.hdr.vpi = htons(vpi);
128	msg.addr.sap_addr.vpi = vpi;
129	msg.hdr.vci = htons(vci);
130	msg.addr.sap_addr.vci = vci;
131	if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) return 0;
132	msg.type = ATMTCP_CTRL_OPEN;
133	msg.qos = vcc->qos;
134	set_bit(ATM_VF_ADDR,&vcc->flags);
135	clear_bit(ATM_VF_READY,&vcc->flags); /* just in case ... */
136	error = atmtcp_send_control(vcc,ATMTCP_CTRL_OPEN,&msg,ATM_VF_READY);
137	if (error) return error;
138	return -sk_atm(vcc)->sk_err;
139}
140
141
142static void atmtcp_v_close(struct atm_vcc *vcc)
143{
144	struct atmtcp_control msg;
145
146	memset(&msg,0,sizeof(msg));
147	msg.addr.sap_family = AF_ATMPVC;
148	msg.addr.sap_addr.vpi = vcc->vpi;
149	msg.addr.sap_addr.vci = vcc->vci;
150	clear_bit(ATM_VF_READY,&vcc->flags);
151	(void) atmtcp_send_control(vcc,ATMTCP_CTRL_CLOSE,&msg,ATM_VF_ADDR);
152}
153
154
155static int atmtcp_v_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg)
156{
157	struct atm_cirange ci;
158	struct atm_vcc *vcc;
159	struct hlist_node *node;
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, node, 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
190static 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 = (void *) 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
234static 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
245static 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
262static 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 hlist_node *node;
267        struct sock *s;
268
269        head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
270
271        sk_for_each(s, node, 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
283static 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		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);
317done:
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
329static 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
345static struct atmdev_ops atmtcp_c_dev_ops = {
346	.close		= atmtcp_c_close,
347	.send		= atmtcp_c_send
348};
349
350
351static 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
359static 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,&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
383static 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) return -EBUSY;
395	}
396	else {
397		int error;
398
399		error = atmtcp_create(itf,0,&dev);
400		if (error) return error;
401	}
402	PRIV(dev)->vcc = vcc;
403	vcc->dev = &atmtcp_control_dev;
404	vcc_insert_socket(sk_atm(vcc));
405	set_bit(ATM_VF_META,&vcc->flags);
406	set_bit(ATM_VF_READY,&vcc->flags);
407	vcc->dev_data = dev;
408	(void) atm_init_aal5(vcc); /* @@@ losing AAL in transit ... */
409	vcc->stats = &atmtcp_control_dev.stats.aal5;
410	return dev->number;
411}
412
413
414static int atmtcp_create_persistent(int itf)
415{
416	return atmtcp_create(itf,1,NULL);
417}
418
419
420static int atmtcp_remove_persistent(int itf)
421{
422	struct atm_dev *dev;
423	struct atmtcp_dev_data *dev_data;
424
425	dev = atm_dev_lookup(itf);
426	if (!dev) return -ENODEV;
427	if (dev->ops != &atmtcp_v_dev_ops) {
428		atm_dev_put(dev);
429		return -EMEDIUMTYPE;
430	}
431	dev_data = PRIV(dev);
432	if (!dev_data->persist) return 0;
433	dev_data->persist = 0;
434	if (PRIV(dev)->vcc) return 0;
435	kfree(dev_data);
436	atm_dev_put(dev);
437	atm_dev_deregister(dev);
438	return 0;
439}
440
441static int atmtcp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
442{
443	int err = 0;
444	struct atm_vcc *vcc = ATM_SD(sock);
445
446	if (cmd != SIOCSIFATMTCP && cmd != ATMTCP_CREATE && cmd != ATMTCP_REMOVE)
447		return -ENOIOCTLCMD;
448
449	if (!capable(CAP_NET_ADMIN))
450		return -EPERM;
451
452	switch (cmd) {
453		case SIOCSIFATMTCP:
454			err = atmtcp_attach(vcc, (int) arg);
455			if (err >= 0) {
456				sock->state = SS_CONNECTED;
457				__module_get(THIS_MODULE);
458			}
459			break;
460		case ATMTCP_CREATE:
461			err = atmtcp_create_persistent((int) arg);
462			break;
463		case ATMTCP_REMOVE:
464			err = atmtcp_remove_persistent((int) arg);
465			break;
466	}
467	return err;
468}
469
470static struct atm_ioctl atmtcp_ioctl_ops = {
471	.owner 	= THIS_MODULE,
472	.ioctl	= atmtcp_ioctl,
473};
474
475static __init int atmtcp_init(void)
476{
477	register_atm_ioctl(&atmtcp_ioctl_ops);
478	return 0;
479}
480
481
482static void __exit atmtcp_exit(void)
483{
484	deregister_atm_ioctl(&atmtcp_ioctl_ops);
485}
486
487MODULE_LICENSE("GPL");
488module_init(atmtcp_init);
489module_exit(atmtcp_exit);
490