[PATCH] w1: Userspace communication protocol over connector.
There are three types of messages between w1 core and userspace: 1. Events. They are generated each time new master or slave device found either due to automatic or requested search. 2. Userspace commands. Includes read/write and search/alarm search comamnds. 3. Replies to userspace commands. From: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Evgeniy Polyakov
committed by
Greg Kroah-Hartman
Greg Kroah-Hartman
parent
81f6075ebc
commit
12003375ac
@@ -21,6 +21,7 @@
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/connector.h>
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#include "w1.h"
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#include "w1_log.h"
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@@ -29,50 +30,204 @@
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#ifndef NETLINK_DISABLED
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void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
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{
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unsigned int size;
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struct sk_buff *skb;
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struct w1_netlink_msg *data;
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struct nlmsghdr *nlh;
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char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
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struct cn_msg *m = (struct cn_msg *)buf;
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struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);
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if (!dev->nls)
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return;
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memset(buf, 0, sizeof(buf));
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size = NLMSG_SPACE(sizeof(struct w1_netlink_msg));
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m->id.idx = CN_W1_IDX;
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m->id.val = CN_W1_VAL;
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skb = alloc_skb(size, GFP_ATOMIC);
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if (!skb) {
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dev_err(&dev->dev, "skb_alloc() failed.\n");
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return;
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}
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m->seq = dev->seq++;
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m->len = sizeof(struct w1_netlink_msg);
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nlh = NLMSG_PUT(skb, 0, dev->seq++, NLMSG_DONE, size - sizeof(*nlh));
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memcpy(w, msg, sizeof(struct w1_netlink_msg));
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data = (struct w1_netlink_msg *)NLMSG_DATA(nlh);
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memcpy(data, msg, sizeof(struct w1_netlink_msg));
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NETLINK_CB(skb).dst_group = dev->groups;
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netlink_broadcast(dev->nls, skb, 0, dev->groups, GFP_ATOMIC);
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nlmsg_failure:
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return;
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cn_netlink_send(m, 0, GFP_KERNEL);
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}
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int dev_init_netlink(struct w1_master *dev)
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static int w1_process_command_master(struct w1_master *dev, struct cn_msg *msg,
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struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
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{
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dev->nls = netlink_kernel_create(NETLINK_W1, 1, NULL, THIS_MODULE);
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if (!dev->nls) {
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printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n",
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NETLINK_W1, dev->dev.bus_id);
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}
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dev_dbg(&dev->dev, "%s: %s: cmd=%02x, len=%u.\n",
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__func__, dev->name, cmd->cmd, cmd->len);
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if (cmd->cmd != W1_CMD_SEARCH && cmd->cmd != W1_CMD_ALARM_SEARCH)
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return -EINVAL;
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w1_search_process(dev, (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
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return 0;
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}
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void dev_fini_netlink(struct w1_master *dev)
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static int w1_send_read_reply(struct w1_slave *sl, struct cn_msg *msg,
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struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
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{
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if (dev->nls && dev->nls->sk_socket)
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sock_release(dev->nls->sk_socket);
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void *data;
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struct w1_netlink_msg *h;
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struct w1_netlink_cmd *c;
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struct cn_msg *cm;
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int err;
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data = kzalloc(sizeof(struct cn_msg) +
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sizeof(struct w1_netlink_msg) +
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sizeof(struct w1_netlink_cmd) +
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cmd->len, GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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cm = (struct cn_msg *)(data);
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h = (struct w1_netlink_msg *)(cm + 1);
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c = (struct w1_netlink_cmd *)(h + 1);
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memcpy(cm, msg, sizeof(struct cn_msg));
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memcpy(h, hdr, sizeof(struct w1_netlink_msg));
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memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
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cm->ack = msg->seq+1;
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cm->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + cmd->len;
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h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
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memcpy(c->data, cmd->data, c->len);
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err = cn_netlink_send(cm, 0, GFP_KERNEL);
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kfree(data);
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return err;
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}
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static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
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struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
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{
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int err = 0;
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dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
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__func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id, sl->reg_num.crc,
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cmd->cmd, cmd->len);
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switch (cmd->cmd) {
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case W1_CMD_READ:
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w1_read_block(sl->master, cmd->data, cmd->len);
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w1_send_read_reply(sl, msg, hdr, cmd);
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break;
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case W1_CMD_WRITE:
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w1_write_block(sl->master, cmd->data, cmd->len);
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break;
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case W1_CMD_SEARCH:
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case W1_CMD_ALARM_SEARCH:
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w1_search_process(sl->master,
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(cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
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break;
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default:
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err = -1;
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break;
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}
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return err;
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}
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static void w1_cn_callback(void *data)
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{
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struct cn_msg *msg = data;
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struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
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struct w1_netlink_cmd *cmd;
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struct w1_slave *sl;
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struct w1_master *dev;
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int err = 0;
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while (msg->len && !err) {
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struct w1_reg_num id;
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u16 mlen = m->len;
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u8 *cmd_data = m->data;
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dev = NULL;
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sl = NULL;
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memcpy(&id, m->id.id, sizeof(id));
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#if 0
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printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
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__func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
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#endif
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if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
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err = -E2BIG;
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break;
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}
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if (!mlen)
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goto out_cont;
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if (m->type == W1_MASTER_CMD) {
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dev = w1_search_master_id(m->id.mst.id);
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} else if (m->type == W1_SLAVE_CMD) {
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sl = w1_search_slave(&id);
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if (sl)
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dev = sl->master;
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}
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if (!dev) {
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err = -ENODEV;
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goto out_cont;
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}
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down(&dev->mutex);
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if (sl && w1_reset_select_slave(sl)) {
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err = -ENODEV;
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goto out_up;
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}
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while (mlen) {
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cmd = (struct w1_netlink_cmd *)cmd_data;
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if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
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err = -E2BIG;
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break;
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}
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if (sl)
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w1_process_command_slave(sl, msg, m, cmd);
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else
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w1_process_command_master(dev, msg, m, cmd);
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cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
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mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
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}
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out_up:
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atomic_dec(&dev->refcnt);
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if (sl)
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atomic_dec(&sl->refcnt);
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up(&dev->mutex);
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out_cont:
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msg->len -= sizeof(struct w1_netlink_msg) + m->len;
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m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
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/*
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* Let's allow requests for nonexisting devices.
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*/
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if (err == -ENODEV)
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err = 0;
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}
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#if 0
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if (err) {
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printk("%s: malformed message. Dropping.\n", __func__);
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}
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#endif
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}
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int w1_init_netlink(void)
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{
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struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
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return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
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}
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void w1_fini_netlink(void)
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{
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struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
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cn_del_callback(&w1_id);
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}
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#else
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#warning Netlink support is disabled. Please compile with NET support enabled.
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@@ -81,12 +236,12 @@ void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
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{
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}
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int dev_init_netlink(struct w1_master *dev)
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int w1_init_netlink(void)
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{
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return 0;
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}
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void dev_fini_netlink(struct w1_master *dev)
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void w1_fini_netlink(void)
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{
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}
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#endif
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