xref: /openbmc/linux/drivers/tty/ipwireless/network.c (revision 8cb5d748)
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 
37 struct 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 
66 static 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  */
90 static 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() */
155 static 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 
242 static const struct ppp_channel_ops ipwireless_ppp_channel_ops = {
243 	.start_xmit = ipwireless_ppp_start_xmit,
244 	.ioctl      = ipwireless_ppp_ioctl
245 };
246 
247 static 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 
289 static 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 
311 void 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  */
344 static 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 	skb_put_data(skb, data, length);
359 
360 	return skb;
361 }
362 
363 void 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 
415 struct 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 
436 void 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 
450 void 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 
463 void 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 
472 void 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 
479 void 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 
487 int 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 
500 int 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 
513 int ipwireless_ppp_mru(const struct ipw_network *network)
514 {
515 	return network->mru;
516 }
517