1/*
2 * IPWireless 3G PCMCIA Network Driver
3 *
4 * Original code
5 *   by Stephen Blackheath <stephen@blacksapphire.com>,
6 *      Ben Martel <benm@symmetric.co.nz>
7 *
8 * Copyrighted as follows:
9 *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
10 *
11 * Various driver changes and rewrites, port to new kernels
12 *   Copyright (C) 2006-2007 Jiri Kosina
13 *
14 * Misc code cleanups and updates
15 *   Copyright (C) 2007 David Sterba
16 */
17
18#include <linux/interrupt.h>
19#include <linux/kernel.h>
20#include <linux/mutex.h>
21#include <linux/netdevice.h>
22#include <linux/ppp_channel.h>
23#include <linux/ppp_defs.h>
24#include <linux/slab.h>
25#include <linux/ppp-ioctl.h>
26#include <linux/skbuff.h>
27
28#include "network.h"
29#include "hardware.h"
30#include "main.h"
31#include "tty.h"
32
33#define MAX_ASSOCIATED_TTYS 2
34
35#define SC_RCV_BITS     (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP)
36
37struct ipw_network {
38	/* Hardware context, used for calls to hardware layer. */
39	struct ipw_hardware *hardware;
40	/* Context for kernel 'generic_ppp' functionality */
41	struct ppp_channel *ppp_channel;
42	/* tty context connected with IPW console */
43	struct ipw_tty *associated_ttys[NO_OF_IPW_CHANNELS][MAX_ASSOCIATED_TTYS];
44	/* True if ppp needs waking up once we're ready to xmit */
45	int ppp_blocked;
46	/* Number of packets queued up in hardware module. */
47	int outgoing_packets_queued;
48	/* Spinlock to avoid interrupts during shutdown */
49	spinlock_t lock;
50	struct mutex close_lock;
51
52	/* PPP ioctl data, not actually used anywere */
53	unsigned int flags;
54	unsigned int rbits;
55	u32 xaccm[8];
56	u32 raccm;
57	int mru;
58
59	int shutting_down;
60	unsigned int ras_control_lines;
61
62	struct work_struct work_go_online;
63	struct work_struct work_go_offline;
64};
65
66static void notify_packet_sent(void *callback_data, unsigned int packet_length)
67{
68	struct ipw_network *network = callback_data;
69	unsigned long flags;
70
71	spin_lock_irqsave(&network->lock, flags);
72	network->outgoing_packets_queued--;
73	if (network->ppp_channel != NULL) {
74		if (network->ppp_blocked) {
75			network->ppp_blocked = 0;
76			spin_unlock_irqrestore(&network->lock, flags);
77			ppp_output_wakeup(network->ppp_channel);
78			if (ipwireless_debug)
79				printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
80				       ": ppp unblocked\n");
81		} else
82			spin_unlock_irqrestore(&network->lock, flags);
83	} else
84		spin_unlock_irqrestore(&network->lock, flags);
85}
86
87/*
88 * Called by the ppp system when it has a packet to send to the hardware.
89 */
90static int ipwireless_ppp_start_xmit(struct ppp_channel *ppp_channel,
91				     struct sk_buff *skb)
92{
93	struct ipw_network *network = ppp_channel->private;
94	unsigned long flags;
95
96	spin_lock_irqsave(&network->lock, flags);
97	if (network->outgoing_packets_queued < ipwireless_out_queue) {
98		unsigned char *buf;
99		static unsigned char header[] = {
100			PPP_ALLSTATIONS, /* 0xff */
101			PPP_UI,		 /* 0x03 */
102		};
103		int ret;
104
105		network->outgoing_packets_queued++;
106		spin_unlock_irqrestore(&network->lock, flags);
107
108		/*
109		 * If we have the requested amount of headroom in the skb we
110		 * were handed, then we can add the header efficiently.
111		 */
112		if (skb_headroom(skb) >= 2) {
113			memcpy(skb_push(skb, 2), header, 2);
114			ret = ipwireless_send_packet(network->hardware,
115					       IPW_CHANNEL_RAS, skb->data,
116					       skb->len,
117					       notify_packet_sent,
118					       network);
119			if (ret == -1) {
120				skb_pull(skb, 2);
121				return 0;
122			}
123		} else {
124			/* Otherwise (rarely) we do it inefficiently. */
125			buf = kmalloc(skb->len + 2, GFP_ATOMIC);
126			if (!buf)
127				return 0;
128			memcpy(buf + 2, skb->data, skb->len);
129			memcpy(buf, header, 2);
130			ret = ipwireless_send_packet(network->hardware,
131					       IPW_CHANNEL_RAS, buf,
132					       skb->len + 2,
133					       notify_packet_sent,
134					       network);
135			kfree(buf);
136			if (ret == -1)
137				return 0;
138		}
139		kfree_skb(skb);
140		return 1;
141	} else {
142		/*
143		 * Otherwise reject the packet, and flag that the ppp system
144		 * needs to be unblocked once we are ready to send.
145		 */
146		network->ppp_blocked = 1;
147		spin_unlock_irqrestore(&network->lock, flags);
148		if (ipwireless_debug)
149			printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": ppp blocked\n");
150		return 0;
151	}
152}
153
154/* Handle an ioctl call that has come in via ppp. (copy of ppp_async_ioctl() */
155static int ipwireless_ppp_ioctl(struct ppp_channel *ppp_channel,
156				unsigned int cmd, unsigned long arg)
157{
158	struct ipw_network *network = ppp_channel->private;
159	int err, val;
160	u32 accm[8];
161	int __user *user_arg = (int __user *) arg;
162
163	err = -EFAULT;
164	switch (cmd) {
165	case PPPIOCGFLAGS:
166		val = network->flags | network->rbits;
167		if (put_user(val, user_arg))
168			break;
169		err = 0;
170		break;
171
172	case PPPIOCSFLAGS:
173		if (get_user(val, user_arg))
174			break;
175		network->flags = val & ~SC_RCV_BITS;
176		network->rbits = val & SC_RCV_BITS;
177		err = 0;
178		break;
179
180	case PPPIOCGASYNCMAP:
181		if (put_user(network->xaccm[0], user_arg))
182			break;
183		err = 0;
184		break;
185
186	case PPPIOCSASYNCMAP:
187		if (get_user(network->xaccm[0], user_arg))
188			break;
189		err = 0;
190		break;
191
192	case PPPIOCGRASYNCMAP:
193		if (put_user(network->raccm, user_arg))
194			break;
195		err = 0;
196		break;
197
198	case PPPIOCSRASYNCMAP:
199		if (get_user(network->raccm, user_arg))
200			break;
201		err = 0;
202		break;
203
204	case PPPIOCGXASYNCMAP:
205		if (copy_to_user((void __user *) arg, network->xaccm,
206					sizeof(network->xaccm)))
207			break;
208		err = 0;
209		break;
210
211	case PPPIOCSXASYNCMAP:
212		if (copy_from_user(accm, (void __user *) arg, sizeof(accm)))
213			break;
214		accm[2] &= ~0x40000000U;	/* can't escape 0x5e */
215		accm[3] |= 0x60000000U;	/* must escape 0x7d, 0x7e */
216		memcpy(network->xaccm, accm, sizeof(network->xaccm));
217		err = 0;
218		break;
219
220	case PPPIOCGMRU:
221		if (put_user(network->mru, user_arg))
222			break;
223		err = 0;
224		break;
225
226	case PPPIOCSMRU:
227		if (get_user(val, user_arg))
228			break;
229		if (val < PPP_MRU)
230			val = PPP_MRU;
231		network->mru = val;
232		err = 0;
233		break;
234
235	default:
236		err = -ENOTTY;
237	}
238
239	return err;
240}
241
242static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
243	.start_xmit = ipwireless_ppp_start_xmit,
244	.ioctl      = ipwireless_ppp_ioctl
245};
246
247static void do_go_online(struct work_struct *work_go_online)
248{
249	struct ipw_network *network =
250		container_of(work_go_online, struct ipw_network,
251				work_go_online);
252	unsigned long flags;
253
254	spin_lock_irqsave(&network->lock, flags);
255	if (!network->ppp_channel) {
256		struct ppp_channel *channel;
257
258		spin_unlock_irqrestore(&network->lock, flags);
259		channel = kzalloc(sizeof(struct ppp_channel), GFP_KERNEL);
260		if (!channel) {
261			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
262					": unable to allocate PPP channel\n");
263			return;
264		}
265		channel->private = network;
266		channel->mtu = 16384;	/* Wild guess */
267		channel->hdrlen = 2;
268		channel->ops = &ipwireless_ppp_channel_ops;
269
270		network->flags = 0;
271		network->rbits = 0;
272		network->mru = PPP_MRU;
273		memset(network->xaccm, 0, sizeof(network->xaccm));
274		network->xaccm[0] = ~0U;
275		network->xaccm[3] = 0x60000000U;
276		network->raccm = ~0U;
277		if (ppp_register_channel(channel) < 0) {
278			printk(KERN_ERR IPWIRELESS_PCCARD_NAME
279					": unable to register PPP channel\n");
280			kfree(channel);
281			return;
282		}
283		spin_lock_irqsave(&network->lock, flags);
284		network->ppp_channel = channel;
285	}
286	spin_unlock_irqrestore(&network->lock, flags);
287}
288
289static void do_go_offline(struct work_struct *work_go_offline)
290{
291	struct ipw_network *network =
292		container_of(work_go_offline, struct ipw_network,
293				work_go_offline);
294	unsigned long flags;
295
296	mutex_lock(&network->close_lock);
297	spin_lock_irqsave(&network->lock, flags);
298	if (network->ppp_channel != NULL) {
299		struct ppp_channel *channel = network->ppp_channel;
300
301		network->ppp_channel = NULL;
302		spin_unlock_irqrestore(&network->lock, flags);
303		mutex_unlock(&network->close_lock);
304		ppp_unregister_channel(channel);
305	} else {
306		spin_unlock_irqrestore(&network->lock, flags);
307		mutex_unlock(&network->close_lock);
308	}
309}
310
311void ipwireless_network_notify_control_line_change(struct ipw_network *network,
312						   unsigned int channel_idx,
313						   unsigned int control_lines,
314						   unsigned int changed_mask)
315{
316	int i;
317
318	if (channel_idx == IPW_CHANNEL_RAS)
319		network->ras_control_lines = control_lines;
320
321	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
322		struct ipw_tty *tty =
323			network->associated_ttys[channel_idx][i];
324
325		/*
326		 * If it's associated with a tty (other than the RAS channel
327		 * when we're online), then send the data to that tty.  The RAS
328		 * channel's data is handled above - it always goes through
329		 * ppp_generic.
330		 */
331		if (tty)
332			ipwireless_tty_notify_control_line_change(tty,
333								  channel_idx,
334								  control_lines,
335								  changed_mask);
336	}
337}
338
339/*
340 * Some versions of firmware stuff packets with 0xff 0x03 (PPP: ALLSTATIONS, UI)
341 * bytes, which are required on sent packet, but not always present on received
342 * packets
343 */
344static struct sk_buff *ipw_packet_received_skb(unsigned char *data,
345					       unsigned int length)
346{
347	struct sk_buff *skb;
348
349	if (length > 2 && data[0] == PPP_ALLSTATIONS && data[1] == PPP_UI) {
350		length -= 2;
351		data += 2;
352	}
353
354	skb = dev_alloc_skb(length + 4);
355	if (skb == NULL)
356		return NULL;
357	skb_reserve(skb, 2);
358	memcpy(skb_put(skb, length), data, length);
359
360	return skb;
361}
362
363void ipwireless_network_packet_received(struct ipw_network *network,
364					unsigned int channel_idx,
365					unsigned char *data,
366					unsigned int length)
367{
368	int i;
369	unsigned long flags;
370
371	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++) {
372		struct ipw_tty *tty = network->associated_ttys[channel_idx][i];
373
374		if (!tty)
375			continue;
376
377		/*
378		 * If it's associated with a tty (other than the RAS channel
379		 * when we're online), then send the data to that tty.  The RAS
380		 * channel's data is handled above - it always goes through
381		 * ppp_generic.
382		 */
383		if (channel_idx == IPW_CHANNEL_RAS
384				&& (network->ras_control_lines &
385					IPW_CONTROL_LINE_DCD) != 0
386				&& ipwireless_tty_is_modem(tty)) {
387			/*
388			 * If data came in on the RAS channel and this tty is
389			 * the modem tty, and we are online, then we send it to
390			 * the PPP layer.
391			 */
392			mutex_lock(&network->close_lock);
393			spin_lock_irqsave(&network->lock, flags);
394			if (network->ppp_channel != NULL) {
395				struct sk_buff *skb;
396
397				spin_unlock_irqrestore(&network->lock,
398						flags);
399
400				/* Send the data to the ppp_generic module. */
401				skb = ipw_packet_received_skb(data, length);
402				if (skb)
403					ppp_input(network->ppp_channel, skb);
404			} else
405				spin_unlock_irqrestore(&network->lock,
406						flags);
407			mutex_unlock(&network->close_lock);
408		}
409		/* Otherwise we send it out the tty. */
410		else
411			ipwireless_tty_received(tty, data, length);
412	}
413}
414
415struct ipw_network *ipwireless_network_create(struct ipw_hardware *hw)
416{
417	struct ipw_network *network =
418		kzalloc(sizeof(struct ipw_network), GFP_ATOMIC);
419
420	if (!network)
421		return NULL;
422
423	spin_lock_init(&network->lock);
424	mutex_init(&network->close_lock);
425
426	network->hardware = hw;
427
428	INIT_WORK(&network->work_go_online, do_go_online);
429	INIT_WORK(&network->work_go_offline, do_go_offline);
430
431	ipwireless_associate_network(hw, network);
432
433	return network;
434}
435
436void ipwireless_network_free(struct ipw_network *network)
437{
438	network->shutting_down = 1;
439
440	ipwireless_ppp_close(network);
441	flush_work(&network->work_go_online);
442	flush_work(&network->work_go_offline);
443
444	ipwireless_stop_interrupts(network->hardware);
445	ipwireless_associate_network(network->hardware, NULL);
446
447	kfree(network);
448}
449
450void ipwireless_associate_network_tty(struct ipw_network *network,
451				      unsigned int channel_idx,
452				      struct ipw_tty *tty)
453{
454	int i;
455
456	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
457		if (network->associated_ttys[channel_idx][i] == NULL) {
458			network->associated_ttys[channel_idx][i] = tty;
459			break;
460		}
461}
462
463void ipwireless_disassociate_network_ttys(struct ipw_network *network,
464					  unsigned int channel_idx)
465{
466	int i;
467
468	for (i = 0; i < MAX_ASSOCIATED_TTYS; i++)
469		network->associated_ttys[channel_idx][i] = NULL;
470}
471
472void ipwireless_ppp_open(struct ipw_network *network)
473{
474	if (ipwireless_debug)
475		printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": online\n");
476	schedule_work(&network->work_go_online);
477}
478
479void ipwireless_ppp_close(struct ipw_network *network)
480{
481	/* Disconnect from the wireless network. */
482	if (ipwireless_debug)
483		printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME ": offline\n");
484	schedule_work(&network->work_go_offline);
485}
486
487int ipwireless_ppp_channel_index(struct ipw_network *network)
488{
489	int ret = -1;
490	unsigned long flags;
491
492	spin_lock_irqsave(&network->lock, flags);
493	if (network->ppp_channel != NULL)
494		ret = ppp_channel_index(network->ppp_channel);
495	spin_unlock_irqrestore(&network->lock, flags);
496
497	return ret;
498}
499
500int ipwireless_ppp_unit_number(struct ipw_network *network)
501{
502	int ret = -1;
503	unsigned long flags;
504
505	spin_lock_irqsave(&network->lock, flags);
506	if (network->ppp_channel != NULL)
507		ret = ppp_unit_number(network->ppp_channel);
508	spin_unlock_irqrestore(&network->lock, flags);
509
510	return ret;
511}
512
513int ipwireless_ppp_mru(const struct ipw_network *network)
514{
515	return network->mru;
516}
517