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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 | */ | |
38 | struct 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 | }; | |
57 | struct 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 | */ | |
74 | static 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 | ||
81 | static 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 | */ | |
101 | static 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. */ | |
114 | static 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 | */ | |
129 | static 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 | */ | |
152 | static 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 | */ | |
179 | static 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 | */ | |
211 | static 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 | */ | |
233 | void 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 | ||
253 | static 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 | ||
275 | static 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) */ | |
284 | static 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 | ||
307 | static 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 | ||
332 | static 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 | ||
366 | static 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 | ||
406 | static 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 | ||
416 | static 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 | ||
461 | static 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 | ||
517 | static 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 | ||
554 | static 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 | ||
711 | out_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 | ||
732 | int 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 | ||
739 | void 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 | |
746 | void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *cn) | |
747 | { | |
748 | } | |
749 | ||
750 | int w1_init_netlink(void) | |
751 | { | |
752 | return 0; | |
753 | } | |
754 | ||
755 | void w1_fini_netlink(void) | |
756 | { | |
757 | } | |
758 | #endif |