[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>
diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c
index 328645d..d48f3ac 100644
--- a/drivers/w1/w1_netlink.c
+++ b/drivers/w1/w1_netlink.c
@@ -21,6 +21,7 @@
#include <linux/skbuff.h>
#include <linux/netlink.h>
+#include <linux/connector.h>
#include "w1.h"
#include "w1_log.h"
@@ -29,50 +30,204 @@
#ifndef NETLINK_DISABLED
void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
{
- unsigned int size;
- struct sk_buff *skb;
- struct w1_netlink_msg *data;
- struct nlmsghdr *nlh;
+ char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
+ struct cn_msg *m = (struct cn_msg *)buf;
+ struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);
- if (!dev->nls)
- return;
+ memset(buf, 0, sizeof(buf));
- size = NLMSG_SPACE(sizeof(struct w1_netlink_msg));
+ m->id.idx = CN_W1_IDX;
+ m->id.val = CN_W1_VAL;
- skb = alloc_skb(size, GFP_ATOMIC);
- if (!skb) {
- dev_err(&dev->dev, "skb_alloc() failed.\n");
- return;
- }
+ m->seq = dev->seq++;
+ m->len = sizeof(struct w1_netlink_msg);
- nlh = NLMSG_PUT(skb, 0, dev->seq++, NLMSG_DONE, size - sizeof(*nlh));
+ memcpy(w, msg, sizeof(struct w1_netlink_msg));
- data = (struct w1_netlink_msg *)NLMSG_DATA(nlh);
-
- memcpy(data, msg, sizeof(struct w1_netlink_msg));
-
- NETLINK_CB(skb).dst_group = dev->groups;
- netlink_broadcast(dev->nls, skb, 0, dev->groups, GFP_ATOMIC);
-
-nlmsg_failure:
- return;
+ cn_netlink_send(m, 0, GFP_KERNEL);
}
-int dev_init_netlink(struct w1_master *dev)
+static int w1_process_command_master(struct w1_master *dev, struct cn_msg *msg,
+ struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
{
- dev->nls = netlink_kernel_create(NETLINK_W1, 1, NULL, THIS_MODULE);
- if (!dev->nls) {
- printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n",
- NETLINK_W1, dev->dev.bus_id);
- }
+ dev_dbg(&dev->dev, "%s: %s: cmd=%02x, len=%u.\n",
+ __func__, dev->name, cmd->cmd, cmd->len);
+ if (cmd->cmd != W1_CMD_SEARCH && cmd->cmd != W1_CMD_ALARM_SEARCH)
+ return -EINVAL;
+
+ w1_search_process(dev, (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
return 0;
}
-void dev_fini_netlink(struct w1_master *dev)
+static int w1_send_read_reply(struct w1_slave *sl, struct cn_msg *msg,
+ struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
{
- if (dev->nls && dev->nls->sk_socket)
- sock_release(dev->nls->sk_socket);
+ void *data;
+ struct w1_netlink_msg *h;
+ struct w1_netlink_cmd *c;
+ struct cn_msg *cm;
+ int err;
+
+ data = kzalloc(sizeof(struct cn_msg) +
+ sizeof(struct w1_netlink_msg) +
+ sizeof(struct w1_netlink_cmd) +
+ cmd->len, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ cm = (struct cn_msg *)(data);
+ h = (struct w1_netlink_msg *)(cm + 1);
+ c = (struct w1_netlink_cmd *)(h + 1);
+
+ memcpy(cm, msg, sizeof(struct cn_msg));
+ memcpy(h, hdr, sizeof(struct w1_netlink_msg));
+ memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
+
+ cm->ack = msg->seq+1;
+ cm->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + cmd->len;
+
+ h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
+
+ memcpy(c->data, cmd->data, c->len);
+
+ err = cn_netlink_send(cm, 0, GFP_KERNEL);
+
+ kfree(data);
+
+ return err;
+}
+
+static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
+ struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
+{
+ int err = 0;
+
+ 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);
+
+ switch (cmd->cmd) {
+ case W1_CMD_READ:
+ w1_read_block(sl->master, cmd->data, cmd->len);
+ w1_send_read_reply(sl, msg, hdr, cmd);
+ break;
+ case W1_CMD_WRITE:
+ w1_write_block(sl->master, cmd->data, cmd->len);
+ break;
+ case W1_CMD_SEARCH:
+ case W1_CMD_ALARM_SEARCH:
+ w1_search_process(sl->master,
+ (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
+ break;
+ default:
+ err = -1;
+ break;
+ }
+
+ return err;
+}
+
+static void w1_cn_callback(void *data)
+{
+ struct cn_msg *msg = data;
+ struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
+ struct w1_netlink_cmd *cmd;
+ struct w1_slave *sl;
+ struct w1_master *dev;
+ int err = 0;
+
+ while (msg->len && !err) {
+ struct w1_reg_num id;
+ u16 mlen = m->len;
+ u8 *cmd_data = m->data;
+
+ dev = NULL;
+ sl = NULL;
+
+ memcpy(&id, m->id.id, sizeof(id));
+#if 0
+ printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
+ __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
+#endif
+ if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
+ err = -E2BIG;
+ break;
+ }
+
+ if (!mlen)
+ goto out_cont;
+
+ if (m->type == W1_MASTER_CMD) {
+ dev = w1_search_master_id(m->id.mst.id);
+ } else if (m->type == W1_SLAVE_CMD) {
+ sl = w1_search_slave(&id);
+ if (sl)
+ dev = sl->master;
+ }
+
+ if (!dev) {
+ err = -ENODEV;
+ goto out_cont;
+ }
+
+ down(&dev->mutex);
+
+ if (sl && w1_reset_select_slave(sl)) {
+ err = -ENODEV;
+ goto out_up;
+ }
+
+ while (mlen) {
+ cmd = (struct w1_netlink_cmd *)cmd_data;
+
+ if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
+ err = -E2BIG;
+ break;
+ }
+
+ if (sl)
+ w1_process_command_slave(sl, msg, m, cmd);
+ else
+ w1_process_command_master(dev, msg, m, cmd);
+
+ cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
+ mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
+ }
+out_up:
+ atomic_dec(&dev->refcnt);
+ if (sl)
+ atomic_dec(&sl->refcnt);
+ up(&dev->mutex);
+out_cont:
+ msg->len -= sizeof(struct w1_netlink_msg) + m->len;
+ m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
+
+ /*
+ * Let's allow requests for nonexisting devices.
+ */
+ if (err == -ENODEV)
+ err = 0;
+ }
+#if 0
+ if (err) {
+ printk("%s: malformed message. Dropping.\n", __func__);
+ }
+#endif
+}
+
+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
#warning Netlink support is disabled. Please compile with NET support enabled.
@@ -81,12 +236,12 @@
{
}
-int dev_init_netlink(struct w1_master *dev)
+int w1_init_netlink(void)
{
return 0;
}
-void dev_fini_netlink(struct w1_master *dev)
+void w1_fini_netlink(void)
{
}
#endif
