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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 */
19struct 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};
38struct 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 */
55static 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
62static 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 */
83static 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. */
97static 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 */
112static 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 */
135static 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 */
162static 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 */
194static void w1_netlink_send_error(struct cn_msg *cn, struct w1_netlink_msg *msg,
195 int portid, int error)
196{
197 struct {
198 struct cn_msg cn;
199 struct w1_netlink_msg msg;
200 } packet;
201 memcpy(&packet.cn, cn, sizeof(packet.cn));
202 memcpy(&packet.msg, msg, sizeof(packet.msg));
203 packet.cn.len = sizeof(packet.msg);
204 packet.msg.len = 0;
205 packet.msg.status = (u8)-error;
206 cn_netlink_send(&packet.cn, 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 */
216void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
217{
218 struct {
219 struct cn_msg cn;
220 struct w1_netlink_msg msg;
221 } packet;
222 memset(&packet, 0, sizeof(packet));
223
224 packet.cn.id.idx = CN_W1_IDX;
225 packet.cn.id.val = CN_W1_VAL;
226
227 packet.cn.seq = dev->seq++;
228 packet.cn.len = sizeof(*msg);
229
230 memcpy(&packet.msg, msg, sizeof(*msg));
231 packet.msg.len = 0;
232
233 cn_netlink_send(&packet.cn, 0, 0, GFP_KERNEL);
234}
235
236static void w1_send_slave(struct w1_master *dev, u64 rn)
237{
238 struct w1_cb_block *block = dev->priv;
239 struct w1_netlink_cmd *cache_cmd = block->cmd;
240 u64 *data;
241
242 w1_reply_make_space(block, sizeof(*data));
243
244 /* Add cmd back if the packet was sent */
245 if (!block->cmd) {
246 cache_cmd->len = 0;
247 w1_netlink_queue_cmd(block, cache_cmd);
248 }
249
250 data = (u64 *)(block->cmd->data + block->cmd->len);
251
252 *data = rn;
253 block->cn->len += sizeof(*data);
254 block->msg->len += sizeof(*data);
255 block->cmd->len += sizeof(*data);
256}
257
258static void w1_found_send_slave(struct w1_master *dev, u64 rn)
259{
260 /* update kernel slave list */
261 w1_slave_found(dev, rn);
262
263 w1_send_slave(dev, rn);
264}
265
266/* Get the current slave list, or search (with or without alarm) */
267static int w1_get_slaves(struct w1_master *dev, struct w1_netlink_cmd *req_cmd)
268{
269 struct w1_slave *sl;
270
271 req_cmd->len = 0;
272 w1_netlink_queue_cmd(dev->priv, req_cmd);
273
274 if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
275 u64 rn;
276 mutex_lock(&dev->list_mutex);
277 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
278 memcpy(&rn, &sl->reg_num, sizeof(rn));
279 w1_send_slave(dev, rn);
280 }
281 mutex_unlock(&dev->list_mutex);
282 } else {
283 w1_search_process_cb(dev, req_cmd->cmd == W1_CMD_ALARM_SEARCH ?
284 W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave);
285 }
286
287 return 0;
288}
289
290static int w1_process_command_io(struct w1_master *dev,
291 struct w1_netlink_cmd *cmd)
292{
293 int err = 0;
294
295 switch (cmd->cmd) {
296 case W1_CMD_TOUCH:
297 w1_touch_block(dev, cmd->data, cmd->len);
298 w1_netlink_queue_cmd(dev->priv, cmd);
299 break;
300 case W1_CMD_READ:
301 w1_read_block(dev, cmd->data, cmd->len);
302 w1_netlink_queue_cmd(dev->priv, cmd);
303 break;
304 case W1_CMD_WRITE:
305 w1_write_block(dev, cmd->data, cmd->len);
306 break;
307 default:
308 err = -EINVAL;
309 break;
310 }
311
312 return err;
313}
314
315static int w1_process_command_addremove(struct w1_master *dev,
316 struct w1_netlink_cmd *cmd)
317{
318 struct w1_slave *sl;
319 int err = 0;
320 struct w1_reg_num *id;
321
322 if (cmd->len != sizeof(*id))
323 return -EINVAL;
324
325 id = (struct w1_reg_num *)cmd->data;
326
327 sl = w1_slave_search_device(dev, id);
328 switch (cmd->cmd) {
329 case W1_CMD_SLAVE_ADD:
330 if (sl)
331 err = -EINVAL;
332 else
333 err = w1_attach_slave_device(dev, id);
334 break;
335 case W1_CMD_SLAVE_REMOVE:
336 if (sl)
337 w1_slave_detach(sl);
338 else
339 err = -EINVAL;
340 break;
341 default:
342 err = -EINVAL;
343 break;
344 }
345
346 return err;
347}
348
349static int w1_process_command_master(struct w1_master *dev,
350 struct w1_netlink_cmd *req_cmd)
351{
352 int err = -EINVAL;
353
354 /* drop bus_mutex for search (does it's own locking), and add/remove
355 * which doesn't use the bus
356 */
357 switch (req_cmd->cmd) {
358 case W1_CMD_SEARCH:
359 case W1_CMD_ALARM_SEARCH:
360 case W1_CMD_LIST_SLAVES:
361 mutex_unlock(&dev->bus_mutex);
362 err = w1_get_slaves(dev, req_cmd);
363 mutex_lock(&dev->bus_mutex);
364 break;
365 case W1_CMD_READ:
366 case W1_CMD_WRITE:
367 case W1_CMD_TOUCH:
368 err = w1_process_command_io(dev, req_cmd);
369 break;
370 case W1_CMD_RESET:
371 err = w1_reset_bus(dev);
372 break;
373 case W1_CMD_SLAVE_ADD:
374 case W1_CMD_SLAVE_REMOVE:
375 mutex_unlock(&dev->bus_mutex);
376 mutex_lock(&dev->mutex);
377 err = w1_process_command_addremove(dev, req_cmd);
378 mutex_unlock(&dev->mutex);
379 mutex_lock(&dev->bus_mutex);
380 break;
381 default:
382 err = -EINVAL;
383 break;
384 }
385
386 return err;
387}
388
389static int w1_process_command_slave(struct w1_slave *sl,
390 struct w1_netlink_cmd *cmd)
391{
392 dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
393 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
394 sl->reg_num.crc, cmd->cmd, cmd->len);
395
396 return w1_process_command_io(sl->master, cmd);
397}
398
399static int w1_process_command_root(struct cn_msg *req_cn, u32 portid)
400{
401 struct w1_master *dev;
402 struct cn_msg *cn;
403 struct w1_netlink_msg *msg;
404 u32 *id;
405
406 cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
407 if (!cn)
408 return -ENOMEM;
409
410 cn->id.idx = CN_W1_IDX;
411 cn->id.val = CN_W1_VAL;
412
413 cn->seq = req_cn->seq;
414 cn->ack = req_cn->seq + 1;
415 cn->len = sizeof(struct w1_netlink_msg);
416 msg = (struct w1_netlink_msg *)cn->data;
417
418 msg->type = W1_LIST_MASTERS;
419 msg->status = 0;
420 msg->len = 0;
421 id = (u32 *)msg->data;
422
423 mutex_lock(&w1_mlock);
424 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
425 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
426 cn_netlink_send(cn, portid, 0, GFP_KERNEL);
427 cn->len = sizeof(struct w1_netlink_msg);
428 msg->len = 0;
429 id = (u32 *)msg->data;
430 }
431
432 *id = dev->id;
433 msg->len += sizeof(*id);
434 cn->len += sizeof(*id);
435 id++;
436 }
437 cn_netlink_send(cn, portid, 0, GFP_KERNEL);
438 mutex_unlock(&w1_mlock);
439
440 kfree(cn);
441 return 0;
442}
443
444static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
445{
446 struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node,
447 async);
448 u16 mlen = node->msg->len;
449 u16 len;
450 int err = 0;
451 struct w1_slave *sl = node->sl;
452 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)node->msg->data;
453
454 mutex_lock(&dev->bus_mutex);
455 dev->priv = node->block;
456 if (sl && w1_reset_select_slave(sl))
457 err = -ENODEV;
458 node->block->cur_msg = node->msg;
459
460 while (mlen && !err) {
461 if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
462 err = -E2BIG;
463 break;
464 }
465
466 if (sl)
467 err = w1_process_command_slave(sl, cmd);
468 else
469 err = w1_process_command_master(dev, cmd);
470 w1_netlink_check_send(node->block);
471
472 w1_netlink_queue_status(node->block, node->msg, cmd, err);
473 err = 0;
474
475 len = sizeof(*cmd) + cmd->len;
476 cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
477 mlen -= len;
478 }
479
480 if (!cmd || err)
481 w1_netlink_queue_status(node->block, node->msg, cmd, err);
482
483 /* ref taken in w1_search_slave or w1_search_master_id when building
484 * the block
485 */
486 if (sl)
487 w1_unref_slave(sl);
488 else
489 atomic_dec(&dev->refcnt);
490 dev->priv = NULL;
491 mutex_unlock(&dev->bus_mutex);
492
493 mutex_lock(&dev->list_mutex);
494 list_del(&async_cmd->async_entry);
495 mutex_unlock(&dev->list_mutex);
496
497 w1_unref_block(node->block);
498}
499
500static void w1_list_count_cmds(struct w1_netlink_msg *msg, int *cmd_count,
501 u16 *slave_len)
502{
503 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)msg->data;
504 u16 mlen = msg->len;
505 u16 len;
506 int slave_list = 0;
507 while (mlen) {
508 if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen)
509 break;
510
511 switch (cmd->cmd) {
512 case W1_CMD_SEARCH:
513 case W1_CMD_ALARM_SEARCH:
514 case W1_CMD_LIST_SLAVES:
515 ++slave_list;
516 }
517 ++*cmd_count;
518 len = sizeof(*cmd) + cmd->len;
519 cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
520 mlen -= len;
521 }
522
523 if (slave_list) {
524 struct w1_master *dev = w1_search_master_id(msg->id.mst.id);
525 if (dev) {
526 /* Bytes, and likely an overstimate, and if it isn't
527 * the results can still be split between packets.
528 */
529 *slave_len += sizeof(struct w1_reg_num) * slave_list *
530 (dev->slave_count + dev->max_slave_count);
531 /* search incremented it */
532 atomic_dec(&dev->refcnt);
533 }
534 }
535}
536
537static void w1_cn_callback(struct cn_msg *cn, struct netlink_skb_parms *nsp)
538{
539 struct w1_netlink_msg *msg = (struct w1_netlink_msg *)(cn + 1);
540 struct w1_slave *sl;
541 struct w1_master *dev;
542 u16 msg_len;
543 u16 slave_len = 0;
544 int err = 0;
545 struct w1_cb_block *block = NULL;
546 struct w1_cb_node *node = NULL;
547 int node_count = 0;
548 int cmd_count = 0;
549
550 /* If any unknown flag is set let the application know, that way
551 * applications can detect the absence of features in kernels that
552 * don't know about them. http://lwn.net/Articles/587527/
553 */
554 if (cn->flags & ~(W1_CN_BUNDLE)) {
555 w1_netlink_send_error(cn, msg, nsp->portid, -EINVAL);
556 return;
557 }
558
559 /* Count the number of master or slave commands there are to allocate
560 * space for one cb_node each.
561 */
562 msg_len = cn->len;
563 while (msg_len && !err) {
564 if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
565 err = -E2BIG;
566 break;
567 }
568
569 /* count messages for nodes and allocate any additional space
570 * required for slave lists
571 */
572 if (msg->type == W1_MASTER_CMD || msg->type == W1_SLAVE_CMD) {
573 ++node_count;
574 w1_list_count_cmds(msg, &cmd_count, &slave_len);
575 }
576
577 msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
578 msg = (struct w1_netlink_msg *)(((u8 *)msg) +
579 sizeof(struct w1_netlink_msg) + msg->len);
580 }
581 msg = (struct w1_netlink_msg *)(cn + 1);
582 if (node_count) {
583 int size;
584 int reply_size = sizeof(*cn) + cn->len + slave_len;
585 if (cn->flags & W1_CN_BUNDLE) {
586 /* bundling duplicats some of the messages */
587 reply_size += 2 * cmd_count * (sizeof(struct cn_msg) +
588 sizeof(struct w1_netlink_msg) +
589 sizeof(struct w1_netlink_cmd));
590 }
591 reply_size = min(CONNECTOR_MAX_MSG_SIZE, reply_size);
592
593 /* allocate space for the block, a copy of the original message,
594 * one node per cmd to point into the original message,
595 * space for replies which is the original message size plus
596 * space for any list slave data and status messages
597 * cn->len doesn't include itself which is part of the block
598 * */
599 size = /* block + original message */
600 sizeof(struct w1_cb_block) + sizeof(*cn) + cn->len +
601 /* space for nodes */
602 node_count * sizeof(struct w1_cb_node) +
603 /* replies */
604 sizeof(struct cn_msg) + reply_size;
605 block = kzalloc(size, GFP_KERNEL);
606 if (!block) {
607 /* if the system is already out of memory,
608 * (A) will this work, and (B) would it be better
609 * to not try?
610 */
611 w1_netlink_send_error(cn, msg, nsp->portid, -ENOMEM);
612 return;
613 }
614 atomic_set(&block->refcnt, 1);
615 block->portid = nsp->portid;
616 block->request_cn = *cn;
617 memcpy(block->request_cn.data, cn->data, cn->len);
618 node = (struct w1_cb_node *)(block->request_cn.data + cn->len);
619
620 /* Sneeky, when not bundling, reply_size is the allocated space
621 * required for the reply, cn_msg isn't part of maxlen so
622 * it should be reply_size - sizeof(struct cn_msg), however
623 * when checking if there is enough space, w1_reply_make_space
624 * is called with the full message size including cn_msg,
625 * because it isn't known at that time if an additional cn_msg
626 * will need to be allocated. So an extra cn_msg is added
627 * above in "size".
628 */
629 block->maxlen = reply_size;
630 block->first_cn = (struct cn_msg *)(node + node_count);
631 memset(block->first_cn, 0, sizeof(*block->first_cn));
632 }
633
634 msg_len = cn->len;
635 while (msg_len && !err) {
636
637 dev = NULL;
638 sl = NULL;
639
640 if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
641 err = -E2BIG;
642 break;
643 }
644
645 /* execute on this thread, no need to process later */
646 if (msg->type == W1_LIST_MASTERS) {
647 err = w1_process_command_root(cn, nsp->portid);
648 goto out_cont;
649 }
650
651 /* All following message types require additional data,
652 * check here before references are taken.
653 */
654 if (!msg->len) {
655 err = -EPROTO;
656 goto out_cont;
657 }
658
659 /* both search calls take references */
660 if (msg->type == W1_MASTER_CMD) {
661 dev = w1_search_master_id(msg->id.mst.id);
662 } else if (msg->type == W1_SLAVE_CMD) {
663 sl = w1_search_slave((struct w1_reg_num *)msg->id.id);
664 if (sl)
665 dev = sl->master;
666 } else {
667 pr_notice("%s: cn: %x.%x, wrong type: %u, len: %u.\n",
668 __func__, cn->id.idx, cn->id.val,
669 msg->type, msg->len);
670 err = -EPROTO;
671 goto out_cont;
672 }
673
674 if (!dev) {
675 err = -ENODEV;
676 goto out_cont;
677 }
678
679 err = 0;
680
681 atomic_inc(&block->refcnt);
682 node->async.cb = w1_process_cb;
683 node->block = block;
684 node->msg = (struct w1_netlink_msg *)((u8 *)&block->request_cn +
685 (size_t)((u8 *)msg - (u8 *)cn));
686 node->sl = sl;
687 node->dev = dev;
688
689 mutex_lock(&dev->list_mutex);
690 list_add_tail(&node->async.async_entry, &dev->async_list);
691 wake_up_process(dev->thread);
692 mutex_unlock(&dev->list_mutex);
693 ++node;
694
695out_cont:
696 /* Can't queue because that modifies block and another
697 * thread could be processing the messages by now and
698 * there isn't a lock, send directly.
699 */
700 if (err)
701 w1_netlink_send_error(cn, msg, nsp->portid, err);
702 msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
703 msg = (struct w1_netlink_msg *)(((u8 *)msg) +
704 sizeof(struct w1_netlink_msg) + msg->len);
705
706 /*
707 * Let's allow requests for nonexisting devices.
708 */
709 if (err == -ENODEV)
710 err = 0;
711 }
712 if (block)
713 w1_unref_block(block);
714}
715
716int w1_init_netlink(void)
717{
718 struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
719
720 return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
721}
722
723void w1_fini_netlink(void)
724{
725 struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
726
727 cn_del_callback(&w1_id);
728}
729#else
730void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *cn)
731{
732}
733
734int w1_init_netlink(void)
735{
736 return 0;
737}
738
739void w1_fini_netlink(void)
740{
741}
742#endif
1/*
2 * w1_netlink.c
3 *
4 * Copyright (c) 2003 Evgeniy Polyakov <zbr@ioremap.net>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/slab.h>
23#include <linux/skbuff.h>
24#include <linux/netlink.h>
25#include <linux/connector.h>
26
27#include "w1.h"
28#include "w1_log.h"
29#include "w1_netlink.h"
30
31#if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
32
33#define MIN(a, b) (((a) < (b)) ? (a) : (b))
34
35/* Bundle together everything required to process a request in one memory
36 * allocation.
37 */
38struct w1_cb_block {
39 atomic_t refcnt;
40 u32 portid; /* Sending process port ID */
41 /* maximum value for first_cn->len */
42 u16 maxlen;
43 /* pointers to building up the reply message */
44 struct cn_msg *first_cn; /* fixed once the structure is populated */
45 struct cn_msg *cn; /* advances as cn_msg is appeneded */
46 struct w1_netlink_msg *msg; /* advances as w1_netlink_msg is appened */
47 struct w1_netlink_cmd *cmd; /* advances as cmds are appened */
48 struct w1_netlink_msg *cur_msg; /* currently message being processed */
49 /* copy of the original request follows */
50 struct cn_msg request_cn;
51 /* followed by variable length:
52 * cn_msg, data (w1_netlink_msg and w1_netlink_cmd)
53 * one or more struct w1_cb_node
54 * reply first_cn, data (w1_netlink_msg and w1_netlink_cmd)
55 */
56};
57struct w1_cb_node {
58 struct w1_async_cmd async;
59 /* pointers within w1_cb_block and cn data */
60 struct w1_cb_block *block;
61 struct w1_netlink_msg *msg;
62 struct w1_slave *sl;
63 struct w1_master *dev;
64};
65
66/**
67 * w1_reply_len() - calculate current reply length, compare to maxlen
68 * @block: block to calculate
69 *
70 * Calculates the current message length including possible multiple
71 * cn_msg and data, excludes the first sizeof(struct cn_msg). Direclty
72 * compariable to maxlen and usable to send the message.
73 */
74static u16 w1_reply_len(struct w1_cb_block *block)
75{
76 if (!block->cn)
77 return 0;
78 return (u8 *)block->cn - (u8 *)block->first_cn + block->cn->len;
79}
80
81static void w1_unref_block(struct w1_cb_block *block)
82{
83 if (atomic_sub_return(1, &block->refcnt) == 0) {
84 u16 len = w1_reply_len(block);
85 if (len) {
86 cn_netlink_send_mult(block->first_cn, len,
87 block->portid, 0, GFP_KERNEL);
88 }
89 kfree(block);
90 }
91}
92
93/**
94 * w1_reply_make_space() - send message if needed to make space
95 * @block: block to make space on
96 * @space: how many bytes requested
97 *
98 * Verify there is enough room left for the caller to add "space" bytes to the
99 * message, if there isn't send the message and reset.
100 */
101static void w1_reply_make_space(struct w1_cb_block *block, u16 space)
102{
103 u16 len = w1_reply_len(block);
104 if (len + space >= block->maxlen) {
105 cn_netlink_send_mult(block->first_cn, len, block->portid, 0, GFP_KERNEL);
106 block->first_cn->len = 0;
107 block->cn = NULL;
108 block->msg = NULL;
109 block->cmd = NULL;
110 }
111}
112
113/* Early send when replies aren't bundled. */
114static void w1_netlink_check_send(struct w1_cb_block *block)
115{
116 if (!(block->request_cn.flags & W1_CN_BUNDLE) && block->cn)
117 w1_reply_make_space(block, block->maxlen);
118}
119
120/**
121 * w1_netlink_setup_msg() - prepare to write block->msg
122 * @block: block to operate on
123 * @ack: determines if cn can be reused
124 *
125 * block->cn will be setup with the correct ack, advancing if needed
126 * block->cn->len does not include space for block->msg
127 * block->msg advances but remains uninitialized
128 */
129static void w1_netlink_setup_msg(struct w1_cb_block *block, u32 ack)
130{
131 if (block->cn && block->cn->ack == ack) {
132 block->msg = (struct w1_netlink_msg *)(block->cn->data + block->cn->len);
133 } else {
134 /* advance or set to data */
135 if (block->cn)
136 block->cn = (struct cn_msg *)(block->cn->data +
137 block->cn->len);
138 else
139 block->cn = block->first_cn;
140
141 memcpy(block->cn, &block->request_cn, sizeof(*block->cn));
142 block->cn->len = 0;
143 block->cn->ack = ack;
144 block->msg = (struct w1_netlink_msg *)block->cn->data;
145 }
146}
147
148/* Append cmd to msg, include cmd->data as well. This is because
149 * any following data goes with the command and in the case of a read is
150 * the results.
151 */
152static void w1_netlink_queue_cmd(struct w1_cb_block *block,
153 struct w1_netlink_cmd *cmd)
154{
155 u32 space;
156 w1_reply_make_space(block, sizeof(struct cn_msg) +
157 sizeof(struct w1_netlink_msg) + sizeof(*cmd) + cmd->len);
158
159 /* There's a status message sent after each command, so no point
160 * in trying to bundle this cmd after an existing one, because
161 * there won't be one. Allocate and copy over a new cn_msg.
162 */
163 w1_netlink_setup_msg(block, block->request_cn.seq + 1);
164 memcpy(block->msg, block->cur_msg, sizeof(*block->msg));
165 block->cn->len += sizeof(*block->msg);
166 block->msg->len = 0;
167 block->cmd = (struct w1_netlink_cmd *)(block->msg->data);
168
169 space = sizeof(*cmd) + cmd->len;
170 if (block->cmd != cmd)
171 memcpy(block->cmd, cmd, space);
172 block->cn->len += space;
173 block->msg->len += space;
174}
175
176/* Append req_msg and req_cmd, no other commands and no data from req_cmd are
177 * copied.
178 */
179static void w1_netlink_queue_status(struct w1_cb_block *block,
180 struct w1_netlink_msg *req_msg, struct w1_netlink_cmd *req_cmd,
181 int error)
182{
183 u16 space = sizeof(struct cn_msg) + sizeof(*req_msg) + sizeof(*req_cmd);
184 w1_reply_make_space(block, space);
185 w1_netlink_setup_msg(block, block->request_cn.ack);
186
187 memcpy(block->msg, req_msg, sizeof(*req_msg));
188 block->cn->len += sizeof(*req_msg);
189 block->msg->len = 0;
190 block->msg->status = (u8)-error;
191 if (req_cmd) {
192 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)block->msg->data;
193 memcpy(cmd, req_cmd, sizeof(*cmd));
194 block->cn->len += sizeof(*cmd);
195 block->msg->len += sizeof(*cmd);
196 cmd->len = 0;
197 }
198 w1_netlink_check_send(block);
199}
200
201/**
202 * w1_netlink_send_error() - sends the error message now
203 * @cn: original cn_msg
204 * @msg: original w1_netlink_msg
205 * @portid: where to send it
206 * @error: error status
207 *
208 * Use when a block isn't available to queue the message to and cn, msg
209 * might not be contiguous.
210 */
211static void w1_netlink_send_error(struct cn_msg *cn, struct w1_netlink_msg *msg,
212 int portid, int error)
213{
214 struct {
215 struct cn_msg cn;
216 struct w1_netlink_msg msg;
217 } packet;
218 memcpy(&packet.cn, cn, sizeof(packet.cn));
219 memcpy(&packet.msg, msg, sizeof(packet.msg));
220 packet.cn.len = sizeof(packet.msg);
221 packet.msg.len = 0;
222 packet.msg.status = (u8)-error;
223 cn_netlink_send(&packet.cn, portid, 0, GFP_KERNEL);
224}
225
226/**
227 * w1_netlink_send() - sends w1 netlink notifications
228 * @dev: w1_master the even is associated with or for
229 * @msg: w1_netlink_msg message to be sent
230 *
231 * This are notifications generated from the kernel.
232 */
233void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
234{
235 struct {
236 struct cn_msg cn;
237 struct w1_netlink_msg msg;
238 } packet;
239 memset(&packet, 0, sizeof(packet));
240
241 packet.cn.id.idx = CN_W1_IDX;
242 packet.cn.id.val = CN_W1_VAL;
243
244 packet.cn.seq = dev->seq++;
245 packet.cn.len = sizeof(*msg);
246
247 memcpy(&packet.msg, msg, sizeof(*msg));
248 packet.msg.len = 0;
249
250 cn_netlink_send(&packet.cn, 0, 0, GFP_KERNEL);
251}
252
253static void w1_send_slave(struct w1_master *dev, u64 rn)
254{
255 struct w1_cb_block *block = dev->priv;
256 struct w1_netlink_cmd *cache_cmd = block->cmd;
257 u64 *data;
258
259 w1_reply_make_space(block, sizeof(*data));
260
261 /* Add cmd back if the packet was sent */
262 if (!block->cmd) {
263 cache_cmd->len = 0;
264 w1_netlink_queue_cmd(block, cache_cmd);
265 }
266
267 data = (u64 *)(block->cmd->data + block->cmd->len);
268
269 *data = rn;
270 block->cn->len += sizeof(*data);
271 block->msg->len += sizeof(*data);
272 block->cmd->len += sizeof(*data);
273}
274
275static void w1_found_send_slave(struct w1_master *dev, u64 rn)
276{
277 /* update kernel slave list */
278 w1_slave_found(dev, rn);
279
280 w1_send_slave(dev, rn);
281}
282
283/* Get the current slave list, or search (with or without alarm) */
284static int w1_get_slaves(struct w1_master *dev, struct w1_netlink_cmd *req_cmd)
285{
286 struct w1_slave *sl;
287
288 req_cmd->len = 0;
289 w1_netlink_queue_cmd(dev->priv, req_cmd);
290
291 if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
292 u64 rn;
293 mutex_lock(&dev->list_mutex);
294 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
295 memcpy(&rn, &sl->reg_num, sizeof(rn));
296 w1_send_slave(dev, rn);
297 }
298 mutex_unlock(&dev->list_mutex);
299 } else {
300 w1_search_process_cb(dev, req_cmd->cmd == W1_CMD_ALARM_SEARCH ?
301 W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave);
302 }
303
304 return 0;
305}
306
307static int w1_process_command_io(struct w1_master *dev,
308 struct w1_netlink_cmd *cmd)
309{
310 int err = 0;
311
312 switch (cmd->cmd) {
313 case W1_CMD_TOUCH:
314 w1_touch_block(dev, cmd->data, cmd->len);
315 w1_netlink_queue_cmd(dev->priv, cmd);
316 break;
317 case W1_CMD_READ:
318 w1_read_block(dev, cmd->data, cmd->len);
319 w1_netlink_queue_cmd(dev->priv, cmd);
320 break;
321 case W1_CMD_WRITE:
322 w1_write_block(dev, cmd->data, cmd->len);
323 break;
324 default:
325 err = -EINVAL;
326 break;
327 }
328
329 return err;
330}
331
332static int w1_process_command_addremove(struct w1_master *dev,
333 struct w1_netlink_cmd *cmd)
334{
335 struct w1_slave *sl;
336 int err = 0;
337 struct w1_reg_num *id;
338
339 if (cmd->len != sizeof(*id))
340 return -EINVAL;
341
342 id = (struct w1_reg_num *)cmd->data;
343
344 sl = w1_slave_search_device(dev, id);
345 switch (cmd->cmd) {
346 case W1_CMD_SLAVE_ADD:
347 if (sl)
348 err = -EINVAL;
349 else
350 err = w1_attach_slave_device(dev, id);
351 break;
352 case W1_CMD_SLAVE_REMOVE:
353 if (sl)
354 w1_slave_detach(sl);
355 else
356 err = -EINVAL;
357 break;
358 default:
359 err = -EINVAL;
360 break;
361 }
362
363 return err;
364}
365
366static int w1_process_command_master(struct w1_master *dev,
367 struct w1_netlink_cmd *req_cmd)
368{
369 int err = -EINVAL;
370
371 /* drop bus_mutex for search (does it's own locking), and add/remove
372 * which doesn't use the bus
373 */
374 switch (req_cmd->cmd) {
375 case W1_CMD_SEARCH:
376 case W1_CMD_ALARM_SEARCH:
377 case W1_CMD_LIST_SLAVES:
378 mutex_unlock(&dev->bus_mutex);
379 err = w1_get_slaves(dev, req_cmd);
380 mutex_lock(&dev->bus_mutex);
381 break;
382 case W1_CMD_READ:
383 case W1_CMD_WRITE:
384 case W1_CMD_TOUCH:
385 err = w1_process_command_io(dev, req_cmd);
386 break;
387 case W1_CMD_RESET:
388 err = w1_reset_bus(dev);
389 break;
390 case W1_CMD_SLAVE_ADD:
391 case W1_CMD_SLAVE_REMOVE:
392 mutex_unlock(&dev->bus_mutex);
393 mutex_lock(&dev->mutex);
394 err = w1_process_command_addremove(dev, req_cmd);
395 mutex_unlock(&dev->mutex);
396 mutex_lock(&dev->bus_mutex);
397 break;
398 default:
399 err = -EINVAL;
400 break;
401 }
402
403 return err;
404}
405
406static int w1_process_command_slave(struct w1_slave *sl,
407 struct w1_netlink_cmd *cmd)
408{
409 dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
410 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
411 sl->reg_num.crc, cmd->cmd, cmd->len);
412
413 return w1_process_command_io(sl->master, cmd);
414}
415
416static int w1_process_command_root(struct cn_msg *req_cn, u32 portid)
417{
418 struct w1_master *dev;
419 struct cn_msg *cn;
420 struct w1_netlink_msg *msg;
421 u32 *id;
422
423 cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
424 if (!cn)
425 return -ENOMEM;
426
427 cn->id.idx = CN_W1_IDX;
428 cn->id.val = CN_W1_VAL;
429
430 cn->seq = req_cn->seq;
431 cn->ack = req_cn->seq + 1;
432 cn->len = sizeof(struct w1_netlink_msg);
433 msg = (struct w1_netlink_msg *)cn->data;
434
435 msg->type = W1_LIST_MASTERS;
436 msg->status = 0;
437 msg->len = 0;
438 id = (u32 *)msg->data;
439
440 mutex_lock(&w1_mlock);
441 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
442 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
443 cn_netlink_send(cn, portid, 0, GFP_KERNEL);
444 cn->len = sizeof(struct w1_netlink_msg);
445 msg->len = 0;
446 id = (u32 *)msg->data;
447 }
448
449 *id = dev->id;
450 msg->len += sizeof(*id);
451 cn->len += sizeof(*id);
452 id++;
453 }
454 cn_netlink_send(cn, portid, 0, GFP_KERNEL);
455 mutex_unlock(&w1_mlock);
456
457 kfree(cn);
458 return 0;
459}
460
461static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
462{
463 struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node,
464 async);
465 u16 mlen = node->msg->len;
466 u16 len;
467 int err = 0;
468 struct w1_slave *sl = node->sl;
469 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)node->msg->data;
470
471 mutex_lock(&dev->bus_mutex);
472 dev->priv = node->block;
473 if (sl && w1_reset_select_slave(sl))
474 err = -ENODEV;
475 node->block->cur_msg = node->msg;
476
477 while (mlen && !err) {
478 if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
479 err = -E2BIG;
480 break;
481 }
482
483 if (sl)
484 err = w1_process_command_slave(sl, cmd);
485 else
486 err = w1_process_command_master(dev, cmd);
487 w1_netlink_check_send(node->block);
488
489 w1_netlink_queue_status(node->block, node->msg, cmd, err);
490 err = 0;
491
492 len = sizeof(*cmd) + cmd->len;
493 cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
494 mlen -= len;
495 }
496
497 if (!cmd || err)
498 w1_netlink_queue_status(node->block, node->msg, cmd, err);
499
500 /* ref taken in w1_search_slave or w1_search_master_id when building
501 * the block
502 */
503 if (sl)
504 w1_unref_slave(sl);
505 else
506 atomic_dec(&dev->refcnt);
507 dev->priv = NULL;
508 mutex_unlock(&dev->bus_mutex);
509
510 mutex_lock(&dev->list_mutex);
511 list_del(&async_cmd->async_entry);
512 mutex_unlock(&dev->list_mutex);
513
514 w1_unref_block(node->block);
515}
516
517static void w1_list_count_cmds(struct w1_netlink_msg *msg, int *cmd_count,
518 u16 *slave_len)
519{
520 struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)msg->data;
521 u16 mlen = msg->len;
522 u16 len;
523 int slave_list = 0;
524 while (mlen) {
525 if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen)
526 break;
527
528 switch (cmd->cmd) {
529 case W1_CMD_SEARCH:
530 case W1_CMD_ALARM_SEARCH:
531 case W1_CMD_LIST_SLAVES:
532 ++slave_list;
533 }
534 ++*cmd_count;
535 len = sizeof(*cmd) + cmd->len;
536 cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
537 mlen -= len;
538 }
539
540 if (slave_list) {
541 struct w1_master *dev = w1_search_master_id(msg->id.mst.id);
542 if (dev) {
543 /* Bytes, and likely an overstimate, and if it isn't
544 * the results can still be split between packets.
545 */
546 *slave_len += sizeof(struct w1_reg_num) * slave_list *
547 (dev->slave_count + dev->max_slave_count);
548 /* search incremented it */
549 atomic_dec(&dev->refcnt);
550 }
551 }
552}
553
554static void w1_cn_callback(struct cn_msg *cn, struct netlink_skb_parms *nsp)
555{
556 struct w1_netlink_msg *msg = (struct w1_netlink_msg *)(cn + 1);
557 struct w1_slave *sl;
558 struct w1_master *dev;
559 u16 msg_len;
560 u16 slave_len = 0;
561 int err = 0;
562 struct w1_cb_block *block = NULL;
563 struct w1_cb_node *node = NULL;
564 int node_count = 0;
565 int cmd_count = 0;
566
567 /* If any unknown flag is set let the application know, that way
568 * applications can detect the absence of features in kernels that
569 * don't know about them. http://lwn.net/Articles/587527/
570 */
571 if (cn->flags & ~(W1_CN_BUNDLE)) {
572 w1_netlink_send_error(cn, msg, nsp->portid, -EINVAL);
573 return;
574 }
575
576 /* Count the number of master or slave commands there are to allocate
577 * space for one cb_node each.
578 */
579 msg_len = cn->len;
580 while (msg_len && !err) {
581 if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
582 err = -E2BIG;
583 break;
584 }
585
586 /* count messages for nodes and allocate any additional space
587 * required for slave lists
588 */
589 if (msg->type == W1_MASTER_CMD || msg->type == W1_SLAVE_CMD) {
590 ++node_count;
591 w1_list_count_cmds(msg, &cmd_count, &slave_len);
592 }
593
594 msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
595 msg = (struct w1_netlink_msg *)(((u8 *)msg) +
596 sizeof(struct w1_netlink_msg) + msg->len);
597 }
598 msg = (struct w1_netlink_msg *)(cn + 1);
599 if (node_count) {
600 int size;
601 int reply_size = sizeof(*cn) + cn->len + slave_len;
602 if (cn->flags & W1_CN_BUNDLE) {
603 /* bundling duplicats some of the messages */
604 reply_size += 2 * cmd_count * (sizeof(struct cn_msg) +
605 sizeof(struct w1_netlink_msg) +
606 sizeof(struct w1_netlink_cmd));
607 }
608 reply_size = MIN(CONNECTOR_MAX_MSG_SIZE, reply_size);
609
610 /* allocate space for the block, a copy of the original message,
611 * one node per cmd to point into the original message,
612 * space for replies which is the original message size plus
613 * space for any list slave data and status messages
614 * cn->len doesn't include itself which is part of the block
615 * */
616 size = /* block + original message */
617 sizeof(struct w1_cb_block) + sizeof(*cn) + cn->len +
618 /* space for nodes */
619 node_count * sizeof(struct w1_cb_node) +
620 /* replies */
621 sizeof(struct cn_msg) + reply_size;
622 block = kzalloc(size, GFP_KERNEL);
623 if (!block) {
624 /* if the system is already out of memory,
625 * (A) will this work, and (B) would it be better
626 * to not try?
627 */
628 w1_netlink_send_error(cn, msg, nsp->portid, -ENOMEM);
629 return;
630 }
631 atomic_set(&block->refcnt, 1);
632 block->portid = nsp->portid;
633 memcpy(&block->request_cn, cn, sizeof(*cn) + cn->len);
634 node = (struct w1_cb_node *)(block->request_cn.data + cn->len);
635
636 /* Sneeky, when not bundling, reply_size is the allocated space
637 * required for the reply, cn_msg isn't part of maxlen so
638 * it should be reply_size - sizeof(struct cn_msg), however
639 * when checking if there is enough space, w1_reply_make_space
640 * is called with the full message size including cn_msg,
641 * because it isn't known at that time if an additional cn_msg
642 * will need to be allocated. So an extra cn_msg is added
643 * above in "size".
644 */
645 block->maxlen = reply_size;
646 block->first_cn = (struct cn_msg *)(node + node_count);
647 memset(block->first_cn, 0, sizeof(*block->first_cn));
648 }
649
650 msg_len = cn->len;
651 while (msg_len && !err) {
652
653 dev = NULL;
654 sl = NULL;
655
656 if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
657 err = -E2BIG;
658 break;
659 }
660
661 /* execute on this thread, no need to process later */
662 if (msg->type == W1_LIST_MASTERS) {
663 err = w1_process_command_root(cn, nsp->portid);
664 goto out_cont;
665 }
666
667 /* All following message types require additional data,
668 * check here before references are taken.
669 */
670 if (!msg->len) {
671 err = -EPROTO;
672 goto out_cont;
673 }
674
675 /* both search calls take references */
676 if (msg->type == W1_MASTER_CMD) {
677 dev = w1_search_master_id(msg->id.mst.id);
678 } else if (msg->type == W1_SLAVE_CMD) {
679 sl = w1_search_slave((struct w1_reg_num *)msg->id.id);
680 if (sl)
681 dev = sl->master;
682 } else {
683 pr_notice("%s: cn: %x.%x, wrong type: %u, len: %u.\n",
684 __func__, cn->id.idx, cn->id.val,
685 msg->type, msg->len);
686 err = -EPROTO;
687 goto out_cont;
688 }
689
690 if (!dev) {
691 err = -ENODEV;
692 goto out_cont;
693 }
694
695 err = 0;
696
697 atomic_inc(&block->refcnt);
698 node->async.cb = w1_process_cb;
699 node->block = block;
700 node->msg = (struct w1_netlink_msg *)((u8 *)&block->request_cn +
701 (size_t)((u8 *)msg - (u8 *)cn));
702 node->sl = sl;
703 node->dev = dev;
704
705 mutex_lock(&dev->list_mutex);
706 list_add_tail(&node->async.async_entry, &dev->async_list);
707 wake_up_process(dev->thread);
708 mutex_unlock(&dev->list_mutex);
709 ++node;
710
711out_cont:
712 /* Can't queue because that modifies block and another
713 * thread could be processing the messages by now and
714 * there isn't a lock, send directly.
715 */
716 if (err)
717 w1_netlink_send_error(cn, msg, nsp->portid, err);
718 msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
719 msg = (struct w1_netlink_msg *)(((u8 *)msg) +
720 sizeof(struct w1_netlink_msg) + msg->len);
721
722 /*
723 * Let's allow requests for nonexisting devices.
724 */
725 if (err == -ENODEV)
726 err = 0;
727 }
728 if (block)
729 w1_unref_block(block);
730}
731
732int w1_init_netlink(void)
733{
734 struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
735
736 return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
737}
738
739void w1_fini_netlink(void)
740{
741 struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
742
743 cn_del_callback(&w1_id);
744}
745#else
746void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *cn)
747{
748}
749
750int w1_init_netlink(void)
751{
752 return 0;
753}
754
755void w1_fini_netlink(void)
756{
757}
758#endif