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 743