aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/w1/w1_netlink.c
blob: 55aabd927c60557e82c01a3eb11d92cd9bcd18c1 (plain)
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
/*
 * w1_netlink.c
 *
 * Copyright (c) 2003 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/connector.h>

#include "w1.h"
#include "w1_log.h"
#include "w1_netlink.h"

#if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
{
	char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
	struct cn_msg *m = (struct cn_msg *)buf;
	struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);

	memset(buf, 0, sizeof(buf));

	m->id.idx = CN_W1_IDX;
	m->id.val = CN_W1_VAL;

	m->seq = dev->seq++;
	m->len = sizeof(struct w1_netlink_msg);

	memcpy(w, msg, sizeof(struct w1_netlink_msg));

	cn_netlink_send(m, 0, GFP_KERNEL);
}

static void w1_send_slave(struct w1_master *dev, u64 rn)
{
	struct cn_msg *msg = dev->priv;
	struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
	struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
	int avail;

	/* update kernel slave list */
	w1_slave_found(dev, rn);

	avail = dev->priv_size - cmd->len;

	if (avail > 8) {
		u64 *data = (void *)(cmd + 1) + cmd->len;

		*data = rn;
		cmd->len += 8;
		hdr->len += 8;
		msg->len += 8;
		return;
	}

	msg->ack++;
	cn_netlink_send(msg, 0, GFP_KERNEL);

	msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
	hdr->len = sizeof(struct w1_netlink_cmd);
	cmd->len = 0;
}

static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,
		unsigned int avail)
{
	struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
	struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
	int search_type = (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH;

	dev->priv = msg;
	dev->priv_size = avail;

	w1_search_process_cb(dev, search_type, w1_send_slave);

	msg->ack = 0;
	cn_netlink_send(msg, 0, GFP_KERNEL);

	dev->priv = NULL;
	dev->priv_size = 0;

	return 0;
}

static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
		struct w1_netlink_cmd *cmd)
{
	void *data;
	struct w1_netlink_msg *h;
	struct w1_netlink_cmd *c;
	struct cn_msg *cm;
	int err;

	data = kzalloc(sizeof(struct cn_msg) +
			sizeof(struct w1_netlink_msg) +
			sizeof(struct w1_netlink_cmd) +
			cmd->len, GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	cm = (struct cn_msg *)(data);
	h = (struct w1_netlink_msg *)(cm + 1);
	c = (struct w1_netlink_cmd *)(h + 1);

	memcpy(cm, msg, sizeof(struct cn_msg));
	memcpy(h, hdr, sizeof(struct w1_netlink_msg));
	memcpy(c, cmd, sizeof(struct w1_netlink_cmd));

	cm->ack = msg->seq+1;
	cm->len = sizeof(struct w1_netlink_msg) +
		sizeof(struct w1_netlink_cmd) + cmd->len;

	h->len = sizeof(struct w1_netlink_cmd) + cmd->len;

	memcpy(c->data, cmd->data, c->len);

	err = cn_netlink_send(cm, 0, GFP_KERNEL);

	kfree(data);

	return err;
}

static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
		struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
{
	int err = 0;

	switch (cmd->cmd) {
	case W1_CMD_TOUCH:
		w1_touch_block(dev, cmd->data, cmd->len);
		w1_send_read_reply(msg, hdr, cmd);
		break;
	case W1_CMD_READ:
		w1_read_block(dev, cmd->data, cmd->len);
		w1_send_read_reply(msg, hdr, cmd);
		break;
	case W1_CMD_WRITE:
		w1_write_block(dev, cmd->data, cmd->len);
		break;
	default:
		err = -EINVAL;
		break;
	}

	return err;
}

static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
		struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
{
	int err = -EINVAL;
	struct cn_msg *msg;
	struct w1_netlink_msg *hdr;
	struct w1_netlink_cmd *cmd;

	msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	msg->id = req_msg->id;
	msg->seq = req_msg->seq;
	msg->ack = 0;
	msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);

	hdr = (struct w1_netlink_msg *)(msg + 1);
	cmd = (struct w1_netlink_cmd *)(hdr + 1);

	hdr->type = W1_MASTER_CMD;
	hdr->id = req_hdr->id;
	hdr->len = sizeof(struct w1_netlink_cmd);

	cmd->cmd = req_cmd->cmd;
	cmd->len = 0;

	switch (cmd->cmd) {
	case W1_CMD_SEARCH:
	case W1_CMD_ALARM_SEARCH:
		err = w1_process_search_command(dev, msg,
				PAGE_SIZE - msg->len - sizeof(struct cn_msg));
		break;
	case W1_CMD_READ:
	case W1_CMD_WRITE:
	case W1_CMD_TOUCH:
		err = w1_process_command_io(dev, req_msg, req_hdr, req_cmd);
		break;
	case W1_CMD_RESET:
		err = w1_reset_bus(dev);
		break;
	default:
		err = -EINVAL;
		break;
	}

	kfree(msg);
	return err;
}

static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
		struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
{
	dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
		__func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
		sl->reg_num.crc, cmd->cmd, cmd->len);

	return w1_process_command_io(sl->master, msg, hdr, cmd);
}

static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
{
	struct w1_master *m;
	struct cn_msg *cn;
	struct w1_netlink_msg *w;
	u32 *id;

	if (mcmd->type != W1_LIST_MASTERS) {
		printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
			__func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
		return -EPROTO;
	}

	cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!cn)
		return -ENOMEM;

	cn->id.idx = CN_W1_IDX;
	cn->id.val = CN_W1_VAL;

	cn->seq = msg->seq;
	cn->ack = 1;
	cn->len = sizeof(struct w1_netlink_msg);
	w = (struct w1_netlink_msg *)(cn + 1);

	w->type = W1_LIST_MASTERS;
	w->status = 0;
	w->len = 0;
	id = (u32 *)(w + 1);

	mutex_lock(&w1_mlock);
	list_for_each_entry(m, &w1_masters, w1_master_entry) {
		if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
			cn_netlink_send(cn, 0, GFP_KERNEL);
			cn->ack++;
			cn->len = sizeof(struct w1_netlink_msg);
			w->len = 0;
			id = (u32 *)(w + 1);
		}

		*id = m->id;
		w->len += sizeof(*id);
		cn->len += sizeof(*id);
		id++;
	}
	cn->ack = 0;
	cn_netlink_send(cn, 0, GFP_KERNEL);
	mutex_unlock(&w1_mlock);

	kfree(cn);
	return 0;
}

static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg,
		struct w1_netlink_cmd *rcmd, int error)
{
	struct cn_msg *cmsg;
	struct w1_netlink_msg *msg;
	struct w1_netlink_cmd *cmd;

	cmsg = kzalloc(sizeof(*msg) + sizeof(*cmd) + sizeof(*cmsg), GFP_KERNEL);
	if (!cmsg)
		return -ENOMEM;

	msg = (struct w1_netlink_msg *)(cmsg + 1);
	cmd = (struct w1_netlink_cmd *)(msg + 1);

	memcpy(cmsg, rcmsg, sizeof(*cmsg));
	cmsg->len = sizeof(*msg);

	memcpy(msg, rmsg, sizeof(*msg));
	msg->len = 0;
	msg->status = (short)-error;

	if (rcmd) {
		memcpy(cmd, rcmd, sizeof(*cmd));
		cmd->len = 0;
		msg->len += sizeof(*cmd);
		cmsg->len += sizeof(*cmd);
	}

	error = cn_netlink_send(cmsg, 0, GFP_KERNEL);
	kfree(cmsg);

	return error;
}

static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
	struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
	struct w1_netlink_cmd *cmd;
	struct w1_slave *sl;
	struct w1_master *dev;
	int err = 0;

	while (msg->len && !err) {
		struct w1_reg_num id;
		u16 mlen = m->len;
		u8 *cmd_data = m->data;

		dev = NULL;
		sl = NULL;
		cmd = NULL;

		memcpy(&id, m->id.id, sizeof(id));
#if 0
		printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
				__func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
#endif
		if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
			err = -E2BIG;
			break;
		}

		if (m->type == W1_MASTER_CMD) {
			dev = w1_search_master_id(m->id.mst.id);
		} else if (m->type == W1_SLAVE_CMD) {
			sl = w1_search_slave(&id);
			if (sl)
				dev = sl->master;
		} else {
			err = w1_process_command_root(msg, m);
			goto out_cont;
		}

		if (!dev) {
			err = -ENODEV;
			goto out_cont;
		}

		err = 0;
		if (!mlen)
			goto out_cont;

		mutex_lock(&dev->mutex);

		if (sl && w1_reset_select_slave(sl)) {
			err = -ENODEV;
			goto out_up;
		}

		while (mlen) {
			cmd = (struct w1_netlink_cmd *)cmd_data;

			if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
				err = -E2BIG;
				break;
			}

			if (sl)
				err = w1_process_command_slave(sl, msg, m, cmd);
			else
				err = w1_process_command_master(dev, msg, m, cmd);

			w1_netlink_send_error(msg, m, cmd, err);
			err = 0;

			cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
			mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
		}
out_up:
		atomic_dec(&dev->refcnt);
		if (sl)
			atomic_dec(&sl->refcnt);
		mutex_unlock(&dev->mutex);
out_cont:
		if (!cmd || err)
			w1_netlink_send_error(msg, m, cmd, err);
		msg->len -= sizeof(struct w1_netlink_msg) + m->len;
		m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);

		/*
		 * Let's allow requests for nonexisting devices.
		 */
		if (err == -ENODEV)
			err = 0;
	}
}

int w1_init_netlink(void)
{
	struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};

	return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
}

void w1_fini_netlink(void)
{
	struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};

	cn_del_callback(&w1_id);
}
#else
void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
{
}

int w1_init_netlink(void)
{
	return 0;
}

void w1_fini_netlink(void)
{
}
#endif