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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/w1/w1_netlink.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/w1/w1_netlink.c')
-rw-r--r--kernel/drivers/w1/w1_netlink.c758
1 files changed, 758 insertions, 0 deletions
diff --git a/kernel/drivers/w1/w1_netlink.c b/kernel/drivers/w1/w1_netlink.c
new file mode 100644
index 000000000..881597a19
--- /dev/null
+++ b/kernel/drivers/w1/w1_netlink.c
@@ -0,0 +1,758 @@
+/*
+ * w1_netlink.c
+ *
+ * Copyright (c) 2003 Evgeniy Polyakov <zbr@ioremap.net>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/connector.h>
+
+#include "w1.h"
+#include "w1_log.h"
+#include "w1_netlink.h"
+
+#if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
+
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+
+/* Bundle together everything required to process a request in one memory
+ * allocation.
+ */
+struct w1_cb_block {
+ atomic_t refcnt;
+ u32 portid; /* Sending process port ID */
+ /* maximum value for first_cn->len */
+ u16 maxlen;
+ /* pointers to building up the reply message */
+ struct cn_msg *first_cn; /* fixed once the structure is populated */
+ struct cn_msg *cn; /* advances as cn_msg is appeneded */
+ struct w1_netlink_msg *msg; /* advances as w1_netlink_msg is appened */
+ struct w1_netlink_cmd *cmd; /* advances as cmds are appened */
+ struct w1_netlink_msg *cur_msg; /* currently message being processed */
+ /* copy of the original request follows */
+ struct cn_msg request_cn;
+ /* followed by variable length:
+ * cn_msg, data (w1_netlink_msg and w1_netlink_cmd)
+ * one or more struct w1_cb_node
+ * reply first_cn, data (w1_netlink_msg and w1_netlink_cmd)
+ */
+};
+struct w1_cb_node {
+ struct w1_async_cmd async;
+ /* pointers within w1_cb_block and cn data */
+ struct w1_cb_block *block;
+ struct w1_netlink_msg *msg;
+ struct w1_slave *sl;
+ struct w1_master *dev;
+};
+
+/**
+ * w1_reply_len() - calculate current reply length, compare to maxlen
+ * @block: block to calculate
+ *
+ * Calculates the current message length including possible multiple
+ * cn_msg and data, excludes the first sizeof(struct cn_msg). Direclty
+ * compariable to maxlen and usable to send the message.
+ */
+static u16 w1_reply_len(struct w1_cb_block *block)
+{
+ if (!block->cn)
+ return 0;
+ return (u8 *)block->cn - (u8 *)block->first_cn + block->cn->len;
+}
+
+static void w1_unref_block(struct w1_cb_block *block)
+{
+ if (atomic_sub_return(1, &block->refcnt) == 0) {
+ u16 len = w1_reply_len(block);
+ if (len) {
+ cn_netlink_send_mult(block->first_cn, len,
+ block->portid, 0, GFP_KERNEL);
+ }
+ kfree(block);
+ }
+}
+
+/**
+ * w1_reply_make_space() - send message if needed to make space
+ * @block: block to make space on
+ * @space: how many bytes requested
+ *
+ * Verify there is enough room left for the caller to add "space" bytes to the
+ * message, if there isn't send the message and reset.
+ */
+static void w1_reply_make_space(struct w1_cb_block *block, u16 space)
+{
+ u16 len = w1_reply_len(block);
+ if (len + space >= block->maxlen) {
+ cn_netlink_send_mult(block->first_cn, len, block->portid, 0, GFP_KERNEL);
+ block->first_cn->len = 0;
+ block->cn = NULL;
+ block->msg = NULL;
+ block->cmd = NULL;
+ }
+}
+
+/* Early send when replies aren't bundled. */
+static void w1_netlink_check_send(struct w1_cb_block *block)
+{
+ if (!(block->request_cn.flags & W1_CN_BUNDLE) && block->cn)
+ w1_reply_make_space(block, block->maxlen);
+}
+
+/**
+ * w1_netlink_setup_msg() - prepare to write block->msg
+ * @block: block to operate on
+ * @ack: determines if cn can be reused
+ *
+ * block->cn will be setup with the correct ack, advancing if needed
+ * block->cn->len does not include space for block->msg
+ * block->msg advances but remains uninitialized
+ */
+static void w1_netlink_setup_msg(struct w1_cb_block *block, u32 ack)
+{
+ if (block->cn && block->cn->ack == ack) {
+ block->msg = (struct w1_netlink_msg *)(block->cn->data + block->cn->len);
+ } else {
+ /* advance or set to data */
+ if (block->cn)
+ block->cn = (struct cn_msg *)(block->cn->data +
+ block->cn->len);
+ else
+ block->cn = block->first_cn;
+
+ memcpy(block->cn, &block->request_cn, sizeof(*block->cn));
+ block->cn->len = 0;
+ block->cn->ack = ack;
+ block->msg = (struct w1_netlink_msg *)block->cn->data;
+ }
+}
+
+/* Append cmd to msg, include cmd->data as well. This is because
+ * any following data goes with the command and in the case of a read is
+ * the results.
+ */
+static void w1_netlink_queue_cmd(struct w1_cb_block *block,
+ struct w1_netlink_cmd *cmd)
+{
+ u32 space;
+ w1_reply_make_space(block, sizeof(struct cn_msg) +
+ sizeof(struct w1_netlink_msg) + sizeof(*cmd) + cmd->len);
+
+ /* There's a status message sent after each command, so no point
+ * in trying to bundle this cmd after an existing one, because
+ * there won't be one. Allocate and copy over a new cn_msg.
+ */
+ w1_netlink_setup_msg(block, block->request_cn.seq + 1);
+ memcpy(block->msg, block->cur_msg, sizeof(*block->msg));
+ block->cn->len += sizeof(*block->msg);
+ block->msg->len = 0;
+ block->cmd = (struct w1_netlink_cmd *)(block->msg->data);
+
+ space = sizeof(*cmd) + cmd->len;
+ if (block->cmd != cmd)
+ memcpy(block->cmd, cmd, space);
+ block->cn->len += space;
+ block->msg->len += space;
+}
+
+/* Append req_msg and req_cmd, no other commands and no data from req_cmd are
+ * copied.
+ */
+static void w1_netlink_queue_status(struct w1_cb_block *block,
+ struct w1_netlink_msg *req_msg, struct w1_netlink_cmd *req_cmd,
+ int error)
+{
+ u16 space = sizeof(struct cn_msg) + sizeof(*req_msg) + sizeof(*req_cmd);
+ w1_reply_make_space(block, space);
+ w1_netlink_setup_msg(block, block->request_cn.ack);
+
+ memcpy(block->msg, req_msg, sizeof(*req_msg));
+ block->cn->len += sizeof(*req_msg);
+ block->msg->len = 0;
+ block->msg->status = (u8)-error;
+ if (req_cmd) {
+ struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)block->msg->data;
+ memcpy(cmd, req_cmd, sizeof(*cmd));
+ block->cn->len += sizeof(*cmd);
+ block->msg->len += sizeof(*cmd);
+ cmd->len = 0;
+ }
+ w1_netlink_check_send(block);
+}
+
+/**
+ * w1_netlink_send_error() - sends the error message now
+ * @cn: original cn_msg
+ * @msg: original w1_netlink_msg
+ * @portid: where to send it
+ * @error: error status
+ *
+ * Use when a block isn't available to queue the message to and cn, msg
+ * might not be contiguous.
+ */
+static void w1_netlink_send_error(struct cn_msg *cn, struct w1_netlink_msg *msg,
+ int portid, int error)
+{
+ struct {
+ struct cn_msg cn;
+ struct w1_netlink_msg msg;
+ } packet;
+ memcpy(&packet.cn, cn, sizeof(packet.cn));
+ memcpy(&packet.msg, msg, sizeof(packet.msg));
+ packet.cn.len = sizeof(packet.msg);
+ packet.msg.len = 0;
+ packet.msg.status = (u8)-error;
+ cn_netlink_send(&packet.cn, portid, 0, GFP_KERNEL);
+}
+
+/**
+ * w1_netlink_send() - sends w1 netlink notifications
+ * @dev: w1_master the even is associated with or for
+ * @msg: w1_netlink_msg message to be sent
+ *
+ * This are notifications generated from the kernel.
+ */
+void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
+{
+ struct {
+ struct cn_msg cn;
+ struct w1_netlink_msg msg;
+ } packet;
+ memset(&packet, 0, sizeof(packet));
+
+ packet.cn.id.idx = CN_W1_IDX;
+ packet.cn.id.val = CN_W1_VAL;
+
+ packet.cn.seq = dev->seq++;
+ packet.cn.len = sizeof(*msg);
+
+ memcpy(&packet.msg, msg, sizeof(*msg));
+ packet.msg.len = 0;
+
+ cn_netlink_send(&packet.cn, 0, 0, GFP_KERNEL);
+}
+
+static void w1_send_slave(struct w1_master *dev, u64 rn)
+{
+ struct w1_cb_block *block = dev->priv;
+ struct w1_netlink_cmd *cache_cmd = block->cmd;
+ u64 *data;
+
+ w1_reply_make_space(block, sizeof(*data));
+
+ /* Add cmd back if the packet was sent */
+ if (!block->cmd) {
+ cache_cmd->len = 0;
+ w1_netlink_queue_cmd(block, cache_cmd);
+ }
+
+ data = (u64 *)(block->cmd->data + block->cmd->len);
+
+ *data = rn;
+ block->cn->len += sizeof(*data);
+ block->msg->len += sizeof(*data);
+ block->cmd->len += sizeof(*data);
+}
+
+static void w1_found_send_slave(struct w1_master *dev, u64 rn)
+{
+ /* update kernel slave list */
+ w1_slave_found(dev, rn);
+
+ w1_send_slave(dev, rn);
+}
+
+/* Get the current slave list, or search (with or without alarm) */
+static int w1_get_slaves(struct w1_master *dev, struct w1_netlink_cmd *req_cmd)
+{
+ struct w1_slave *sl;
+
+ req_cmd->len = 0;
+ w1_netlink_queue_cmd(dev->priv, req_cmd);
+
+ if (req_cmd->cmd == W1_CMD_LIST_SLAVES) {
+ u64 rn;
+ mutex_lock(&dev->list_mutex);
+ list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
+ memcpy(&rn, &sl->reg_num, sizeof(rn));
+ w1_send_slave(dev, rn);
+ }
+ mutex_unlock(&dev->list_mutex);
+ } else {
+ w1_search_process_cb(dev, req_cmd->cmd == W1_CMD_ALARM_SEARCH ?
+ W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave);
+ }
+
+ return 0;
+}
+
+static int w1_process_command_io(struct w1_master *dev,
+ struct w1_netlink_cmd *cmd)
+{
+ int err = 0;
+
+ switch (cmd->cmd) {
+ case W1_CMD_TOUCH:
+ w1_touch_block(dev, cmd->data, cmd->len);
+ w1_netlink_queue_cmd(dev->priv, cmd);
+ break;
+ case W1_CMD_READ:
+ w1_read_block(dev, cmd->data, cmd->len);
+ w1_netlink_queue_cmd(dev->priv, cmd);
+ break;
+ case W1_CMD_WRITE:
+ w1_write_block(dev, cmd->data, cmd->len);
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+ return err;
+}
+
+static int w1_process_command_addremove(struct w1_master *dev,
+ struct w1_netlink_cmd *cmd)
+{
+ struct w1_slave *sl;
+ int err = 0;
+ struct w1_reg_num *id;
+
+ if (cmd->len != sizeof(*id))
+ return -EINVAL;
+
+ id = (struct w1_reg_num *)cmd->data;
+
+ sl = w1_slave_search_device(dev, id);
+ switch (cmd->cmd) {
+ case W1_CMD_SLAVE_ADD:
+ if (sl)
+ err = -EINVAL;
+ else
+ err = w1_attach_slave_device(dev, id);
+ break;
+ case W1_CMD_SLAVE_REMOVE:
+ if (sl)
+ w1_slave_detach(sl);
+ else
+ err = -EINVAL;
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+ return err;
+}
+
+static int w1_process_command_master(struct w1_master *dev,
+ struct w1_netlink_cmd *req_cmd)
+{
+ int err = -EINVAL;
+
+ /* drop bus_mutex for search (does it's own locking), and add/remove
+ * which doesn't use the bus
+ */
+ switch (req_cmd->cmd) {
+ case W1_CMD_SEARCH:
+ case W1_CMD_ALARM_SEARCH:
+ case W1_CMD_LIST_SLAVES:
+ mutex_unlock(&dev->bus_mutex);
+ err = w1_get_slaves(dev, req_cmd);
+ mutex_lock(&dev->bus_mutex);
+ break;
+ case W1_CMD_READ:
+ case W1_CMD_WRITE:
+ case W1_CMD_TOUCH:
+ err = w1_process_command_io(dev, req_cmd);
+ break;
+ case W1_CMD_RESET:
+ err = w1_reset_bus(dev);
+ break;
+ case W1_CMD_SLAVE_ADD:
+ case W1_CMD_SLAVE_REMOVE:
+ mutex_unlock(&dev->bus_mutex);
+ mutex_lock(&dev->mutex);
+ err = w1_process_command_addremove(dev, req_cmd);
+ mutex_unlock(&dev->mutex);
+ mutex_lock(&dev->bus_mutex);
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+ return err;
+}
+
+static int w1_process_command_slave(struct w1_slave *sl,
+ struct w1_netlink_cmd *cmd)
+{
+ dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
+ __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
+ sl->reg_num.crc, cmd->cmd, cmd->len);
+
+ return w1_process_command_io(sl->master, cmd);
+}
+
+static int w1_process_command_root(struct cn_msg *req_cn, u32 portid)
+{
+ struct w1_master *dev;
+ struct cn_msg *cn;
+ struct w1_netlink_msg *msg;
+ u32 *id;
+
+ cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!cn)
+ return -ENOMEM;
+
+ cn->id.idx = CN_W1_IDX;
+ cn->id.val = CN_W1_VAL;
+
+ cn->seq = req_cn->seq;
+ cn->ack = req_cn->seq + 1;
+ cn->len = sizeof(struct w1_netlink_msg);
+ msg = (struct w1_netlink_msg *)cn->data;
+
+ msg->type = W1_LIST_MASTERS;
+ msg->status = 0;
+ msg->len = 0;
+ id = (u32 *)msg->data;
+
+ mutex_lock(&w1_mlock);
+ list_for_each_entry(dev, &w1_masters, w1_master_entry) {
+ if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
+ cn_netlink_send(cn, portid, 0, GFP_KERNEL);
+ cn->len = sizeof(struct w1_netlink_msg);
+ msg->len = 0;
+ id = (u32 *)msg->data;
+ }
+
+ *id = dev->id;
+ msg->len += sizeof(*id);
+ cn->len += sizeof(*id);
+ id++;
+ }
+ cn_netlink_send(cn, portid, 0, GFP_KERNEL);
+ mutex_unlock(&w1_mlock);
+
+ kfree(cn);
+ return 0;
+}
+
+static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
+{
+ struct w1_cb_node *node = container_of(async_cmd, struct w1_cb_node,
+ async);
+ u16 mlen = node->msg->len;
+ u16 len;
+ int err = 0;
+ struct w1_slave *sl = node->sl;
+ struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)node->msg->data;
+
+ mutex_lock(&dev->bus_mutex);
+ dev->priv = node->block;
+ if (sl && w1_reset_select_slave(sl))
+ err = -ENODEV;
+ node->block->cur_msg = node->msg;
+
+ while (mlen && !err) {
+ if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
+ err = -E2BIG;
+ break;
+ }
+
+ if (sl)
+ err = w1_process_command_slave(sl, cmd);
+ else
+ err = w1_process_command_master(dev, cmd);
+ w1_netlink_check_send(node->block);
+
+ w1_netlink_queue_status(node->block, node->msg, cmd, err);
+ err = 0;
+
+ len = sizeof(*cmd) + cmd->len;
+ cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
+ mlen -= len;
+ }
+
+ if (!cmd || err)
+ w1_netlink_queue_status(node->block, node->msg, cmd, err);
+
+ /* ref taken in w1_search_slave or w1_search_master_id when building
+ * the block
+ */
+ if (sl)
+ w1_unref_slave(sl);
+ else
+ atomic_dec(&dev->refcnt);
+ dev->priv = NULL;
+ mutex_unlock(&dev->bus_mutex);
+
+ mutex_lock(&dev->list_mutex);
+ list_del(&async_cmd->async_entry);
+ mutex_unlock(&dev->list_mutex);
+
+ w1_unref_block(node->block);
+}
+
+static void w1_list_count_cmds(struct w1_netlink_msg *msg, int *cmd_count,
+ u16 *slave_len)
+{
+ struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)msg->data;
+ u16 mlen = msg->len;
+ u16 len;
+ int slave_list = 0;
+ while (mlen) {
+ if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen)
+ break;
+
+ switch (cmd->cmd) {
+ case W1_CMD_SEARCH:
+ case W1_CMD_ALARM_SEARCH:
+ case W1_CMD_LIST_SLAVES:
+ ++slave_list;
+ }
+ ++*cmd_count;
+ len = sizeof(*cmd) + cmd->len;
+ cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len);
+ mlen -= len;
+ }
+
+ if (slave_list) {
+ struct w1_master *dev = w1_search_master_id(msg->id.mst.id);
+ if (dev) {
+ /* Bytes, and likely an overstimate, and if it isn't
+ * the results can still be split between packets.
+ */
+ *slave_len += sizeof(struct w1_reg_num) * slave_list *
+ (dev->slave_count + dev->max_slave_count);
+ /* search incremented it */
+ atomic_dec(&dev->refcnt);
+ }
+ }
+}
+
+static void w1_cn_callback(struct cn_msg *cn, struct netlink_skb_parms *nsp)
+{
+ struct w1_netlink_msg *msg = (struct w1_netlink_msg *)(cn + 1);
+ struct w1_slave *sl;
+ struct w1_master *dev;
+ u16 msg_len;
+ u16 slave_len = 0;
+ int err = 0;
+ struct w1_cb_block *block = NULL;
+ struct w1_cb_node *node = NULL;
+ int node_count = 0;
+ int cmd_count = 0;
+
+ /* If any unknown flag is set let the application know, that way
+ * applications can detect the absence of features in kernels that
+ * don't know about them. http://lwn.net/Articles/587527/
+ */
+ if (cn->flags & ~(W1_CN_BUNDLE)) {
+ w1_netlink_send_error(cn, msg, nsp->portid, -EINVAL);
+ return;
+ }
+
+ /* Count the number of master or slave commands there are to allocate
+ * space for one cb_node each.
+ */
+ msg_len = cn->len;
+ while (msg_len && !err) {
+ if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
+ err = -E2BIG;
+ break;
+ }
+
+ /* count messages for nodes and allocate any additional space
+ * required for slave lists
+ */
+ if (msg->type == W1_MASTER_CMD || msg->type == W1_SLAVE_CMD) {
+ ++node_count;
+ w1_list_count_cmds(msg, &cmd_count, &slave_len);
+ }
+
+ msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
+ msg = (struct w1_netlink_msg *)(((u8 *)msg) +
+ sizeof(struct w1_netlink_msg) + msg->len);
+ }
+ msg = (struct w1_netlink_msg *)(cn + 1);
+ if (node_count) {
+ int size;
+ int reply_size = sizeof(*cn) + cn->len + slave_len;
+ if (cn->flags & W1_CN_BUNDLE) {
+ /* bundling duplicats some of the messages */
+ reply_size += 2 * cmd_count * (sizeof(struct cn_msg) +
+ sizeof(struct w1_netlink_msg) +
+ sizeof(struct w1_netlink_cmd));
+ }
+ reply_size = MIN(CONNECTOR_MAX_MSG_SIZE, reply_size);
+
+ /* allocate space for the block, a copy of the original message,
+ * one node per cmd to point into the original message,
+ * space for replies which is the original message size plus
+ * space for any list slave data and status messages
+ * cn->len doesn't include itself which is part of the block
+ * */
+ size = /* block + original message */
+ sizeof(struct w1_cb_block) + sizeof(*cn) + cn->len +
+ /* space for nodes */
+ node_count * sizeof(struct w1_cb_node) +
+ /* replies */
+ sizeof(struct cn_msg) + reply_size;
+ block = kzalloc(size, GFP_KERNEL);
+ if (!block) {
+ /* if the system is already out of memory,
+ * (A) will this work, and (B) would it be better
+ * to not try?
+ */
+ w1_netlink_send_error(cn, msg, nsp->portid, -ENOMEM);
+ return;
+ }
+ atomic_set(&block->refcnt, 1);
+ block->portid = nsp->portid;
+ memcpy(&block->request_cn, cn, sizeof(*cn) + cn->len);
+ node = (struct w1_cb_node *)(block->request_cn.data + cn->len);
+
+ /* Sneeky, when not bundling, reply_size is the allocated space
+ * required for the reply, cn_msg isn't part of maxlen so
+ * it should be reply_size - sizeof(struct cn_msg), however
+ * when checking if there is enough space, w1_reply_make_space
+ * is called with the full message size including cn_msg,
+ * because it isn't known at that time if an additional cn_msg
+ * will need to be allocated. So an extra cn_msg is added
+ * above in "size".
+ */
+ block->maxlen = reply_size;
+ block->first_cn = (struct cn_msg *)(node + node_count);
+ memset(block->first_cn, 0, sizeof(*block->first_cn));
+ }
+
+ msg_len = cn->len;
+ while (msg_len && !err) {
+
+ dev = NULL;
+ sl = NULL;
+
+ if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) {
+ err = -E2BIG;
+ break;
+ }
+
+ /* execute on this thread, no need to process later */
+ if (msg->type == W1_LIST_MASTERS) {
+ err = w1_process_command_root(cn, nsp->portid);
+ goto out_cont;
+ }
+
+ /* All following message types require additional data,
+ * check here before references are taken.
+ */
+ if (!msg->len) {
+ err = -EPROTO;
+ goto out_cont;
+ }
+
+ /* both search calls take references */
+ if (msg->type == W1_MASTER_CMD) {
+ dev = w1_search_master_id(msg->id.mst.id);
+ } else if (msg->type == W1_SLAVE_CMD) {
+ sl = w1_search_slave((struct w1_reg_num *)msg->id.id);
+ if (sl)
+ dev = sl->master;
+ } else {
+ pr_notice("%s: cn: %x.%x, wrong type: %u, len: %u.\n",
+ __func__, cn->id.idx, cn->id.val,
+ msg->type, msg->len);
+ err = -EPROTO;
+ goto out_cont;
+ }
+
+ if (!dev) {
+ err = -ENODEV;
+ goto out_cont;
+ }
+
+ err = 0;
+
+ atomic_inc(&block->refcnt);
+ node->async.cb = w1_process_cb;
+ node->block = block;
+ node->msg = (struct w1_netlink_msg *)((u8 *)&block->request_cn +
+ (size_t)((u8 *)msg - (u8 *)cn));
+ node->sl = sl;
+ node->dev = dev;
+
+ mutex_lock(&dev->list_mutex);
+ list_add_tail(&node->async.async_entry, &dev->async_list);
+ wake_up_process(dev->thread);
+ mutex_unlock(&dev->list_mutex);
+ ++node;
+
+out_cont:
+ /* Can't queue because that modifies block and another
+ * thread could be processing the messages by now and
+ * there isn't a lock, send directly.
+ */
+ if (err)
+ w1_netlink_send_error(cn, msg, nsp->portid, err);
+ msg_len -= sizeof(struct w1_netlink_msg) + msg->len;
+ msg = (struct w1_netlink_msg *)(((u8 *)msg) +
+ sizeof(struct w1_netlink_msg) + msg->len);
+
+ /*
+ * Let's allow requests for nonexisting devices.
+ */
+ if (err == -ENODEV)
+ err = 0;
+ }
+ if (block)
+ w1_unref_block(block);
+}
+
+int w1_init_netlink(void)
+{
+ struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
+
+ return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
+}
+
+void w1_fini_netlink(void)
+{
+ struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
+
+ cn_del_callback(&w1_id);
+}
+#else
+void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *cn)
+{
+}
+
+int w1_init_netlink(void)
+{
+ return 0;
+}
+
+void w1_fini_netlink(void)
+{
+}
+#endif