From 12003375acd879e498c6c511faf27531296f9640 Mon Sep 17 00:00:00 2001 From: Evgeniy Polyakov Date: Thu, 23 Mar 2006 19:11:58 +0300 Subject: [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 Signed-off-by: Greg Kroah-Hartman --- drivers/w1/w1_netlink.c | 215 +++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 185 insertions(+), 30 deletions(-) (limited to 'drivers/w1/w1_netlink.c') diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c index 328645da79727f..d48f3acdb8a298 100644 --- a/drivers/w1/w1_netlink.c +++ b/drivers/w1/w1_netlink.c @@ -21,6 +21,7 @@ #include #include +#include #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); + cn_netlink_send(m, 0, GFP_KERNEL); +} - memcpy(data, msg, sizeof(struct w1_netlink_msg)); +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_dbg(&dev->dev, "%s: %s: cmd=%02x, len=%u.\n", + __func__, dev->name, cmd->cmd, cmd->len); - NETLINK_CB(skb).dst_group = dev->groups; - netlink_broadcast(dev->nls, skb, 0, dev->groups, GFP_ATOMIC); + if (cmd->cmd != W1_CMD_SEARCH && cmd->cmd != W1_CMD_ALARM_SEARCH) + return -EINVAL; -nlmsg_failure: - return; + w1_search_process(dev, (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH); + return 0; } -int dev_init_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) { - 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); + 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 0; + 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 } -void dev_fini_netlink(struct w1_master *dev) +int w1_init_netlink(void) { - if (dev->nls && dev->nls->sk_socket) - sock_release(dev->nls->sk_socket); + 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 @@ void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg) { } -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 -- cgit 1.2.3-korg