1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2003 Evgeniy Polyakov <zbr@ioremap.net>
4 */
5
6 #include <linux/slab.h>
7 #include <linux/skbuff.h>
8 #include <linux/netlink.h>
9 #include <linux/connector.h>
10
11 #include "w1_internal.h"
12 #include "w1_netlink.h"
13
14 #if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
15
16 /* Bundle together everything required to process a request in one memory
17 * allocation.
18 */
19 struct w1_cb_block {
20 atomic_t refcnt;
21 u32 portid; /* Sending process port ID */
22 /* maximum value for first_cn->len */
23 u16 maxlen;
24 /* pointers to building up the reply message */
25 struct cn_msg *first_cn; /* fixed once the structure is populated */
26 struct cn_msg *cn; /* advances as cn_msg is appeneded */
27 struct w1_netlink_msg *msg; /* advances as w1_netlink_msg is appened */
28 struct w1_netlink_cmd *cmd; /* advances as cmds are appened */
29 struct w1_netlink_msg *cur_msg; /* currently message being processed */
30 /* copy of the original request follows */
31 struct cn_msg request_cn;
32 /* followed by variable length:
33 * cn_msg, data (w1_netlink_msg and w1_netlink_cmd)
34 * one or more struct w1_cb_node
35 * reply first_cn, data (w1_netlink_msg and w1_netlink_cmd)
36 */
37 };
38 struct w1_cb_node {
39 struct w1_async_cmd async;
40 /* pointers within w1_cb_block and cn data */
41 struct w1_cb_block *block;
42 struct w1_netlink_msg *msg;
43 struct w1_slave *sl;
44 struct w1_master *dev;
45 };
46
47 /**
48 * w1_reply_len() - calculate current reply length, compare to maxlen
49 * @block: block to calculate
50 *
51 * Calculates the current message length including possible multiple
52 * cn_msg and data, excludes the first sizeof(struct cn_msg). Direclty
53 * compariable to maxlen and usable to send the message.
54 */
w1_reply_len(struct w1_cb_block * block)55 static u16 w1_reply_len(struct w1_cb_block *block)
56 {
57 if (!block->cn)
58 return 0;
59 return (u8 *)block->cn - (u8 *)block->first_cn + block->cn->len;
60 }
61
w1_unref_block(struct w1_cb_block * block)62 static void w1_unref_block(struct w1_cb_block *block)
63 {
64 if (atomic_sub_return(1, &block->refcnt) == 0) {
65 u16 len = w1_reply_len(block);
66 if (len) {
67 cn_netlink_send_mult(block->first_cn, len,
68 block->portid, 0,
69 GFP_KERNEL, NULL, NULL);
70 }
71 kfree(block);
72 }
73 }
74
75 /**
76 * w1_reply_make_space() - send message if needed to make space
77 * @block: block to make space on
78 * @space: how many bytes requested
79 *
80 * Verify there is enough room left for the caller to add "space" bytes to the
81 * message, if there isn't send the message and reset.
82 */
w1_reply_make_space(struct w1_cb_block * block,u16 space)83 static void w1_reply_make_space(struct w1_cb_block *block, u16 space)
84 {
85 u16 len = w1_reply_len(block);
86 if (len + space >= block->maxlen) {
87 cn_netlink_send_mult(block->first_cn, len, block->portid,
88 0, GFP_KERNEL, NULL, NULL);
89 block->first_cn->len = 0;
90 block->cn = NULL;
91 block->msg = NULL;
92 block->cmd = NULL;
93 }
94 }
95
96 /* Early send when replies aren't bundled. */
w1_netlink_check_send(struct w1_cb_block * block)97 static void w1_netlink_check_send(struct w1_cb_block *block)
98 {
99 if (!(block->request_cn.flags & W1_CN_BUNDLE) && block->cn)
100 w1_reply_make_space(block, block->maxlen);
101 }
102
103 /**
104 * w1_netlink_setup_msg() - prepare to write block->msg
105 * @block: block to operate on
106 * @ack: determines if cn can be reused
107 *
108 * block->cn will be setup with the correct ack, advancing if needed
109 * block->cn->len does not include space for block->msg
110 * block->msg advances but remains uninitialized
111 */
w1_netlink_setup_msg(struct w1_cb_block * block,u32 ack)112 static void w1_netlink_setup_msg(struct w1_cb_block *block, u32 ack)
113 {
114 if (block->cn && block->cn->ack == ack) {
115 block->msg = (struct w1_netlink_msg *)(block->cn->data + block->cn->len);
116 } else {
117 /* advance or set to data */
118 if (block->cn)
119 block->cn = (struct cn_msg *)(block->cn->data +
120 block->cn->len);
121 else
122 block->cn = block->first_cn;
123
124 memcpy(block->cn, &block->request_cn, sizeof(*block->cn));
125 block->cn->len = 0;
126 block->cn->ack = ack;
127 block->msg = (struct w1_netlink_msg *)block->cn->data;
128 }
129 }
130
131 /* Append cmd to msg, include cmd->data as well. This is because
132 * any following data goes with the command and in the case of a read is
133 * the results.
134 */
w1_netlink_queue_cmd(struct w1_cb_block * block,struct w1_netlink_cmd * cmd)135 static void w1_netlink_queue_cmd(struct w1_cb_block *block,
136 struct w1_netlink_cmd *cmd)
137 {
138 u32 space;
139 w1_reply_make_space(block, sizeof(struct cn_msg) +
140 sizeof(struct w1_netlink_msg) + sizeof(*cmd) + cmd->len);
141
142 /* There's a status message sent after each command, so no point
143 * in trying to bundle this cmd after an existing one, because
144 * there won't be one. Allocate and copy over a new cn_msg.
145 */
146 w1_netlink_setup_msg(block, block->request_cn.seq + 1);
147 memcpy(block->msg, block->cur_msg, sizeof(*block->msg));
148 block->cn->len += sizeof(*block->msg);
149 block->msg->len = 0;
150 block->cmd = (struct w1_netlink_cmd *)(block->msg->data);
151
152 space = sizeof(*cmd) + cmd->len;
153 if (block->cmd != cmd)
154 memcpy(block->cmd, cmd, space);
155 block->cn->len += space;
156 block->msg->len += space;
157 }
158
159 /* Append req_msg and req_cmd, no other commands and no data from req_cmd are
160 * copied.
161 */
w1_netlink_queue_status(struct w1_cb_block * block,struct w1_netlink_msg * req_msg,struct w1_netlink_cmd * req_cmd,int error)162 static void w1_netlink_queue_status(struct w1_cb_block *block,
163 struct w1_netlink_msg *req_msg, struct w1_netlink_cmd *req_cmd,
164 int error)
165 {
166 u16 space = sizeof(struct cn_msg) + sizeof(*req_msg) + sizeof(*req_cmd);
167 w1_reply_make_space(block, space);
168 w1_netlink_setup_msg(block, block->request_cn.ack);
169
170 memcpy(block->msg, req_msg, sizeof(*req_msg));
171 block->cn->len += sizeof(*req_msg);
172 block->msg->len = 0;
173 block->msg->status = (u8)-error;
174 if (req_cmd) {
175 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)block->msg->data;
176 memcpy(cmd, req_cmd, sizeof(*cmd));
177 block->cn->len += sizeof(*cmd);
178 block->msg->len += sizeof(*cmd);
179 cmd->len = 0;
180 }
181 w1_netlink_check_send(block);
182 }
183
184 /**
185 * w1_netlink_send_error() - sends the error message now
186 * @cn: original cn_msg
187 * @msg: original w1_netlink_msg
188 * @portid: where to send it
189 * @error: error status
190 *
191 * Use when a block isn't available to queue the message to and cn, msg
192 * might not be contiguous.
193 */
w1_netlink_send_error(struct cn_msg * cn,struct w1_netlink_msg * msg,int portid,int error)194 static void w1_netlink_send_error(struct cn_msg *cn, struct w1_netlink_msg *msg,
195 int portid, int error)
196 {
197 DEFINE_RAW_FLEX(struct cn_msg, packet, data,
198 sizeof(struct w1_netlink_msg));
199 struct w1_netlink_msg *pkt_msg = (struct w1_netlink_msg *)packet->data;
200
201 *packet = *cn;
202 *pkt_msg = *msg;
203 packet->len = sizeof(*pkt_msg);
204 pkt_msg->len = 0;
205 pkt_msg->status = (u8)-error;
206 cn_netlink_send(packet, portid, 0, GFP_KERNEL);
207 }
208
209 /**
210 * w1_netlink_send() - sends w1 netlink notifications
211 * @dev: w1_master the even is associated with or for
212 * @msg: w1_netlink_msg message to be sent
213 *
214 * This are notifications generated from the kernel.
215 */
w1_netlink_send(struct w1_master * dev,struct w1_netlink_msg * msg)216 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
217 {
218 DEFINE_RAW_FLEX(struct cn_msg, packet, data,
219 sizeof(struct w1_netlink_msg));
220 struct w1_netlink_msg *pkt_msg = (struct w1_netlink_msg *)packet->data;
221
222 packet->id.idx = CN_W1_IDX;
223 packet->id.val = CN_W1_VAL;
224
225 packet->seq = dev->seq++;
226 packet->len = sizeof(*msg);
227
228 *pkt_msg = *msg;
229 pkt_msg->len = 0;
230
231 cn_netlink_send(packet, 0, 0, GFP_KERNEL);
232 }
233
w1_send_slave(struct w1_master * dev,u64 rn)234 static void w1_send_slave(struct w1_master *dev, u64 rn)
235 {
236 struct w1_cb_block *block = dev->priv;
237 struct w1_netlink_cmd *cache_cmd = block->cmd;
238 u64 *data;
239
240 w1_reply_make_space(block, sizeof(*data));
241
242 /* Add cmd back if the packet was sent */
243 if (!block->cmd) {
244 cache_cmd->len = 0;
245 w1_netlink_queue_cmd(block, cache_cmd);
246 }
247
248 data = (u64 *)(block->cmd->data + block->cmd->len);
249
250 *data = rn;
251 block->cn->len += sizeof(*data);
252 block->msg->len += sizeof(*data);
253 block->cmd->len += sizeof(*data);
254 }
255
w1_found_send_slave(struct w1_master * dev,u64 rn)256 static void w1_found_send_slave(struct w1_master *dev, u64 rn)
257 {
258 /* update kernel slave list */
259 w1_slave_found(dev, rn);
260
261 w1_send_slave(dev, rn);
262 }
263
264 /* Get the current slave list, or search (with or without alarm) */
w1_get_slaves(struct w1_master * dev,struct w1_netlink_cmd * req_cmd)265 static int w1_get_slaves(struct w1_master *dev, struct w1_netlink_cmd *req_cmd)
266 {
267 struct w1_slave *sl;
268
269 req_cmd->len = 0;
270 w1_netlink_queue_cmd(dev->priv, req_cmd);
271
272 if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
273 u64 rn;
274 mutex_lock(&dev->list_mutex);
275 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
276 memcpy(&rn, &sl->reg_num, sizeof(rn));
277 w1_send_slave(dev, rn);
278 }
279 mutex_unlock(&dev->list_mutex);
280 } else {
281 w1_search_process_cb(dev, req_cmd->cmd == W1_CMD_ALARM_SEARCH ?
282 W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave);
283 }
284
285 return 0;
286 }
287
w1_process_command_io(struct w1_master * dev,struct w1_netlink_cmd * cmd)288 static int w1_process_command_io(struct w1_master *dev,
289 struct w1_netlink_cmd *cmd)
290 {
291 int err = 0;
292
293 switch (cmd->cmd) {
294 case W1_CMD_TOUCH:
295 w1_touch_block(dev, cmd->data, cmd->len);
296 w1_netlink_queue_cmd(dev->priv, cmd);
297 break;
298 case W1_CMD_READ:
299 w1_read_block(dev, cmd->data, cmd->len);
300 w1_netlink_queue_cmd(dev->priv, cmd);
301 break;
302 case W1_CMD_WRITE:
303 w1_write_block(dev, cmd->data, cmd->len);
304 break;
305 default:
306 err = -EINVAL;
307 break;
308 }
309
310 return err;
311 }
312
w1_process_command_addremove(struct w1_master * dev,struct w1_netlink_cmd * cmd)313 static int w1_process_command_addremove(struct w1_master *dev,
314 struct w1_netlink_cmd *cmd)
315 {
316 struct w1_slave *sl;
317 int err = 0;
318 struct w1_reg_num *id;
319
320 if (cmd->len != sizeof(*id))
321 return -EINVAL;
322
323 id = (struct w1_reg_num *)cmd->data;
324
325 sl = w1_slave_search_device(dev, id);
326 switch (cmd->cmd) {
327 case W1_CMD_SLAVE_ADD:
328 if (sl)
329 err = -EINVAL;
330 else
331 err = w1_attach_slave_device(dev, id);
332 break;
333 case W1_CMD_SLAVE_REMOVE:
334 if (sl)
335 w1_slave_detach(sl);
336 else
337 err = -EINVAL;
338 break;
339 default:
340 err = -EINVAL;
341 break;
342 }
343
344 return err;
345 }
346
w1_process_command_master(struct w1_master * dev,struct w1_netlink_cmd * req_cmd)347 static int w1_process_command_master(struct w1_master *dev,
348 struct w1_netlink_cmd *req_cmd)
349 {
350 int err = -EINVAL;
351
352 /* drop bus_mutex for search (does it's own locking), and add/remove
353 * which doesn't use the bus
354 */
355 switch (req_cmd->cmd) {
356 case W1_CMD_SEARCH:
357 case W1_CMD_ALARM_SEARCH:
358 case W1_CMD_LIST_SLAVES:
359 mutex_unlock(&dev->bus_mutex);
360 err = w1_get_slaves(dev, req_cmd);
361 mutex_lock(&dev->bus_mutex);
362 break;
363 case W1_CMD_READ:
364 case W1_CMD_WRITE:
365 case W1_CMD_TOUCH:
366 err = w1_process_command_io(dev, req_cmd);
367 break;
368 case W1_CMD_RESET:
369 err = w1_reset_bus(dev);
370 break;
371 case W1_CMD_SLAVE_ADD:
372 case W1_CMD_SLAVE_REMOVE:
373 mutex_unlock(&dev->bus_mutex);
374 mutex_lock(&dev->mutex);
375 err = w1_process_command_addremove(dev, req_cmd);
376 mutex_unlock(&dev->mutex);
377 mutex_lock(&dev->bus_mutex);
378 break;
379 default:
380 err = -EINVAL;
381 break;
382 }
383
384 return err;
385 }
386
w1_process_command_slave(struct w1_slave * sl,struct w1_netlink_cmd * cmd)387 static int w1_process_command_slave(struct w1_slave *sl,
388 struct w1_netlink_cmd *cmd)
389 {
390 dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
391 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
392 sl->reg_num.crc, cmd->cmd, cmd->len);
393
394 return w1_process_command_io(sl->master, cmd);
395 }
396
w1_process_command_root(struct cn_msg * req_cn,u32 portid)397 static int w1_process_command_root(struct cn_msg *req_cn, u32 portid)
398 {
399 struct w1_master *dev;
400 struct cn_msg *cn;
401 struct w1_netlink_msg *msg;
402 u32 *id;
403
404 cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
405 if (!cn)
406 return -ENOMEM;
407
408 cn->id.idx = CN_W1_IDX;
409 cn->id.val = CN_W1_VAL;
410
411 cn->seq = req_cn->seq;
412 cn->ack = req_cn->seq + 1;
413 cn->len = sizeof(struct w1_netlink_msg);
414 msg = (struct w1_netlink_msg *)cn->data;
415
416 msg->type = W1_LIST_MASTERS;
417 msg->status = 0;
418 msg->len = 0;
419 id = (u32 *)msg->data;
420
421 mutex_lock(&w1_mlock);
422 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
423 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
424 cn_netlink_send(cn, portid, 0, GFP_KERNEL);
425 cn->len = sizeof(struct w1_netlink_msg);
426 msg->len = 0;
427 id = (u32 *)msg->data;
428 }
429
430 *id = dev->id;
431 msg->len += sizeof(*id);
432 cn->len += sizeof(*id);
433 id++;
434 }
435 cn_netlink_send(cn, portid, 0, GFP_KERNEL);
436 mutex_unlock(&w1_mlock);
437
438 kfree(cn);
439 return 0;
440 }
441
w1_process_cb(struct w1_master * dev,struct w1_async_cmd * async_cmd)442 static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
443 {
444 struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node,
445 async);
446 u16 mlen = node->msg->len;
447 u16 len;
448 int err = 0;
449 struct w1_slave *sl = node->sl;
450 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)node->msg->data;
451
452 mutex_lock(&dev->bus_mutex);
453 dev->priv = node->block;
454 if (sl && w1_reset_select_slave(sl))
455 err = -ENODEV;
456 node->block->cur_msg = node->msg;
457
458 while (mlen && !err) {
459 if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
460 err = -E2BIG;
461 break;
462 }
463
464 if (sl)
465 err = w1_process_command_slave(sl, cmd);
466 else
467 err = w1_process_command_master(dev, cmd);
468 w1_netlink_check_send(node->block);
469
470 w1_netlink_queue_status(node->block, node->msg, cmd, err);
471 err = 0;
472
473 len = sizeof(*cmd) + cmd->len;
474 cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
475 mlen -= len;
476 }
477
478 if (!cmd || err)
479 w1_netlink_queue_status(node->block, node->msg, cmd, err);
480
481 /* ref taken in w1_search_slave or w1_search_master_id when building
482 * the block
483 */
484 if (sl)
485 w1_unref_slave(sl);
486 else
487 atomic_dec(&dev->refcnt);
488 dev->priv = NULL;
489 mutex_unlock(&dev->bus_mutex);
490
491 mutex_lock(&dev->list_mutex);
492 list_del(&async_cmd->async_entry);
493 mutex_unlock(&dev->list_mutex);
494
495 w1_unref_block(node->block);
496 }
497
w1_list_count_cmds(struct w1_netlink_msg * msg,int * cmd_count,u16 * slave_len)498 static void w1_list_count_cmds(struct w1_netlink_msg *msg, int *cmd_count,
499 u16 *slave_len)
500 {
501 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)msg->data;
502 u16 mlen = msg->len;
503 u16 len;
504 int slave_list = 0;
505 while (mlen) {
506 if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen)
507 break;
508
509 switch (cmd->cmd) {
510 case W1_CMD_SEARCH:
511 case W1_CMD_ALARM_SEARCH:
512 case W1_CMD_LIST_SLAVES:
513 ++slave_list;
514 }
515 ++*cmd_count;
516 len = sizeof(*cmd) + cmd->len;
517 cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
518 mlen -= len;
519 }
520
521 if (slave_list) {
522 struct w1_master *dev = w1_search_master_id(msg->id.mst.id);
523 if (dev) {
524 /* Bytes, and likely an overstimate, and if it isn't
525 * the results can still be split between packets.
526 */
527 *slave_len += sizeof(struct w1_reg_num) * slave_list *
528 (dev->slave_count + dev->max_slave_count);
529 /* search incremented it */
530 atomic_dec(&dev->refcnt);
531 }
532 }
533 }
534
w1_cn_callback(struct cn_msg * cn,struct netlink_skb_parms * nsp)535 static void w1_cn_callback(struct cn_msg *cn, struct netlink_skb_parms *nsp)
536 {
537 struct w1_netlink_msg *msg = (struct w1_netlink_msg *)(cn + 1);
538 struct w1_slave *sl;
539 struct w1_master *dev;
540 u16 msg_len;
541 u16 slave_len = 0;
542 int err = 0;
543 struct w1_cb_block *block = NULL;
544 struct w1_cb_node *node = NULL;
545 int node_count = 0;
546 int cmd_count = 0;
547
548 /* If any unknown flag is set let the application know, that way
549 * applications can detect the absence of features in kernels that
550 * don't know about them. http://lwn.net/Articles/587527/
551 */
552 if (cn->flags & ~(W1_CN_BUNDLE)) {
553 w1_netlink_send_error(cn, msg, nsp->portid, -EINVAL);
554 return;
555 }
556
557 /* Count the number of master or slave commands there are to allocate
558 * space for one cb_node each.
559 */
560 msg_len = cn->len;
561 while (msg_len && !err) {
562 if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
563 err = -E2BIG;
564 break;
565 }
566
567 /* count messages for nodes and allocate any additional space
568 * required for slave lists
569 */
570 if (msg->type == W1_MASTER_CMD || msg->type == W1_SLAVE_CMD) {
571 ++node_count;
572 w1_list_count_cmds(msg, &cmd_count, &slave_len);
573 }
574
575 msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
576 msg = (struct w1_netlink_msg *)(((u8 *)msg) +
577 sizeof(struct w1_netlink_msg) + msg->len);
578 }
579 msg = (struct w1_netlink_msg *)(cn + 1);
580 if (node_count) {
581 int size;
582 int reply_size = sizeof(*cn) + cn->len + slave_len;
583 if (cn->flags & W1_CN_BUNDLE) {
584 /* bundling duplicats some of the messages */
585 reply_size += 2 * cmd_count * (sizeof(struct cn_msg) +
586 sizeof(struct w1_netlink_msg) +
587 sizeof(struct w1_netlink_cmd));
588 }
589 reply_size = min(CONNECTOR_MAX_MSG_SIZE, reply_size);
590
591 /* allocate space for the block, a copy of the original message,
592 * one node per cmd to point into the original message,
593 * space for replies which is the original message size plus
594 * space for any list slave data and status messages
595 * cn->len doesn't include itself which is part of the block
596 * */
597 size = /* block + original message */
598 sizeof(struct w1_cb_block) + sizeof(*cn) + cn->len +
599 /* space for nodes */
600 node_count * sizeof(struct w1_cb_node) +
601 /* replies */
602 sizeof(struct cn_msg) + reply_size;
603 block = kzalloc(size, GFP_KERNEL);
604 if (!block) {
605 /* if the system is already out of memory,
606 * (A) will this work, and (B) would it be better
607 * to not try?
608 */
609 w1_netlink_send_error(cn, msg, nsp->portid, -ENOMEM);
610 return;
611 }
612 atomic_set(&block->refcnt, 1);
613 block->portid = nsp->portid;
614 block->request_cn = *cn;
615 memcpy(block->request_cn.data, cn->data, cn->len);
616 node = (struct w1_cb_node *)(block->request_cn.data + cn->len);
617
618 /* Sneeky, when not bundling, reply_size is the allocated space
619 * required for the reply, cn_msg isn't part of maxlen so
620 * it should be reply_size - sizeof(struct cn_msg), however
621 * when checking if there is enough space, w1_reply_make_space
622 * is called with the full message size including cn_msg,
623 * because it isn't known at that time if an additional cn_msg
624 * will need to be allocated. So an extra cn_msg is added
625 * above in "size".
626 */
627 block->maxlen = reply_size;
628 block->first_cn = (struct cn_msg *)(node + node_count);
629 memset(block->first_cn, 0, sizeof(*block->first_cn));
630 }
631
632 msg_len = cn->len;
633 while (msg_len && !err) {
634
635 dev = NULL;
636 sl = NULL;
637
638 if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
639 err = -E2BIG;
640 break;
641 }
642
643 /* execute on this thread, no need to process later */
644 if (msg->type == W1_LIST_MASTERS) {
645 err = w1_process_command_root(cn, nsp->portid);
646 goto out_cont;
647 }
648
649 /* All following message types require additional data,
650 * check here before references are taken.
651 */
652 if (!msg->len) {
653 err = -EPROTO;
654 goto out_cont;
655 }
656
657 /* both search calls take references */
658 if (msg->type == W1_MASTER_CMD) {
659 dev = w1_search_master_id(msg->id.mst.id);
660 } else if (msg->type == W1_SLAVE_CMD) {
661 sl = w1_search_slave((struct w1_reg_num *)msg->id.id);
662 if (sl)
663 dev = sl->master;
664 } else {
665 pr_notice("%s: cn: %x.%x, wrong type: %u, len: %u.\n",
666 __func__, cn->id.idx, cn->id.val,
667 msg->type, msg->len);
668 err = -EPROTO;
669 goto out_cont;
670 }
671
672 if (!dev) {
673 err = -ENODEV;
674 goto out_cont;
675 }
676
677 err = 0;
678
679 atomic_inc(&block->refcnt);
680 node->async.cb = w1_process_cb;
681 node->block = block;
682 node->msg = (struct w1_netlink_msg *)((u8 *)&block->request_cn +
683 (size_t)((u8 *)msg - (u8 *)cn));
684 node->sl = sl;
685 node->dev = dev;
686
687 mutex_lock(&dev->list_mutex);
688 list_add_tail(&node->async.async_entry, &dev->async_list);
689 wake_up_process(dev->thread);
690 mutex_unlock(&dev->list_mutex);
691 ++node;
692
693 out_cont:
694 /* Can't queue because that modifies block and another
695 * thread could be processing the messages by now and
696 * there isn't a lock, send directly.
697 */
698 if (err)
699 w1_netlink_send_error(cn, msg, nsp->portid, err);
700 msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
701 msg = (struct w1_netlink_msg *)(((u8 *)msg) +
702 sizeof(struct w1_netlink_msg) + msg->len);
703
704 /*
705 * Let's allow requests for nonexisting devices.
706 */
707 if (err == -ENODEV)
708 err = 0;
709 }
710 if (block)
711 w1_unref_block(block);
712 }
713
w1_init_netlink(void)714 int w1_init_netlink(void)
715 {
716 struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
717
718 return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
719 }
720
w1_fini_netlink(void)721 void w1_fini_netlink(void)
722 {
723 struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
724
725 cn_del_callback(&w1_id);
726 }
727 #else
w1_netlink_send(struct w1_master * dev,struct w1_netlink_msg * cn)728 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *cn)
729 {
730 }
731
w1_init_netlink(void)732 int w1_init_netlink(void)
733 {
734 return 0;
735 }
736
w1_fini_netlink(void)737 void w1_fini_netlink(void)
738 {
739 }
740 #endif
741