From 4037014e3fb71e998189374e19ca141c59d15323 Mon Sep 17 00:00:00 2001 From: Evgeniy Polyakov Date: Wed, 7 Jan 2009 18:09:05 -0800 Subject: [PATCH] w1: send status messages after command processing Send completion status of the commands to the userspace. Message and protocol are described in the documentation. Signed-off-by: Evgeniy Polyakov Cc: Paul Alfille Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/w1/w1.netlink | 29 ++++++++++++++++++++ drivers/w1/w1_netlink.c | 53 ++++++++++++++++++++++++++++++++----- drivers/w1/w1_netlink.h | 2 +- 3 files changed, 76 insertions(+), 8 deletions(-) diff --git a/Documentation/w1/w1.netlink b/Documentation/w1/w1.netlink index 2756681b6ef5..804445f745ed 100644 --- a/Documentation/w1/w1.netlink +++ b/Documentation/w1/w1.netlink @@ -118,6 +118,35 @@ W1 reset command. id is equal to the bus master id to use for searching] [w1_netlink_cmd cmd = W1_CMD_RESET] + +Command status replies. +====================== + +Each command (either root, master or slave with or without w1_netlink_cmd +structure) will be 'acked' by the w1 core. Format of the reply is the same +as request message except that length parameters do not account for data +requested by the user, i.e. read/write/touch IO requests will not contain +data, so w1_netlink_cmd.len will be 0, w1_netlink_msg.len will be size +of the w1_netlink_cmd structure and cn_msg.len will be equal to the sum +of the sizeof(struct w1_netlink_msg) and sizeof(struct w1_netlink_cmd). +If reply is generated for master or root command (which do not have +w1_netlink_cmd attached), reply will contain only cn_msg and w1_netlink_msg +structires. + +w1_netlink_msg.status field will carry positive error value +(EINVAL for example) or zero in case of success. + +All other fields in every structure will mirror the same parameters in the +request message (except lengths as described above). + +Status reply is generated for every w1_netlink_cmd embedded in the +w1_netlink_msg, if there are no w1_netlink_cmd structures, +reply will be generated for the w1_netlink_msg. + +All w1_netlink_cmd command structures are handled in every w1_netlink_msg, +even if there were errors, only length mismatch interrupts message processing. + + Operation steps in w1 core when new command is received. ======================================================= diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c index f978c7504004..fdf72851c574 100644 --- a/drivers/w1/w1_netlink.c +++ b/drivers/w1/w1_netlink.c @@ -152,7 +152,7 @@ static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg, w1_write_block(dev, cmd->data, cmd->len); break; default: - err = -1; + err = -EINVAL; break; } @@ -195,14 +195,13 @@ static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_m case W1_CMD_READ: case W1_CMD_WRITE: case W1_CMD_TOUCH: - err = w1_process_command_io(dev, msg, hdr, cmd); + err = w1_process_command_io(dev, req_msg, req_hdr, req_cmd); break; case W1_CMD_RESET: err = w1_reset_bus(dev); break; default: - cmd->res = EINVAL; - cn_netlink_send(msg, 0, GFP_KERNEL); + err = -EINVAL; break; } @@ -246,7 +245,7 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc w = (struct w1_netlink_msg *)(cn + 1); w->type = W1_LIST_MASTERS; - w->reserved = 0; + w->status = 0; w->len = 0; id = (u32 *)(w + 1); @@ -273,6 +272,40 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc return 0; } +static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg, + struct w1_netlink_cmd *rcmd, int error) +{ + struct cn_msg *cmsg; + struct w1_netlink_msg *msg; + struct w1_netlink_cmd *cmd; + + cmsg = kzalloc(sizeof(*msg) + sizeof(*cmd) + sizeof(*cmsg), GFP_KERNEL); + if (!cmsg) + return -ENOMEM; + + msg = (struct w1_netlink_msg *)(cmsg + 1); + cmd = (struct w1_netlink_cmd *)(msg + 1); + + memcpy(cmsg, rcmsg, sizeof(*cmsg)); + cmsg->len = sizeof(*msg); + + memcpy(msg, rmsg, sizeof(*msg)); + msg->len = 0; + msg->status = (short)-error; + + if (rcmd) { + memcpy(cmd, rcmd, sizeof(*cmd)); + cmd->len = 0; + msg->len += sizeof(*cmd); + cmsg->len += sizeof(*cmd); + } + + error = cn_netlink_send(cmsg, 0, GFP_KERNEL); + kfree(cmsg); + + return error; +} + static void w1_cn_callback(void *data) { struct cn_msg *msg = data; @@ -289,6 +322,7 @@ static void w1_cn_callback(void *data) dev = NULL; sl = NULL; + cmd = NULL; memcpy(&id, m->id.id, sizeof(id)); #if 0 @@ -336,9 +370,12 @@ static void w1_cn_callback(void *data) } if (sl) - w1_process_command_slave(sl, msg, m, cmd); + err = w1_process_command_slave(sl, msg, m, cmd); else - w1_process_command_master(dev, msg, m, cmd); + err = w1_process_command_master(dev, msg, m, cmd); + + w1_netlink_send_error(msg, m, cmd, err); + err = 0; cmd_data += cmd->len + sizeof(struct w1_netlink_cmd); mlen -= cmd->len + sizeof(struct w1_netlink_cmd); @@ -349,6 +386,8 @@ out_up: atomic_dec(&sl->refcnt); mutex_unlock(&dev->mutex); out_cont: + if (!cmd || err) + w1_netlink_send_error(msg, m, cmd, err); msg->len -= sizeof(struct w1_netlink_msg) + m->len; m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len); diff --git a/drivers/w1/w1_netlink.h b/drivers/w1/w1_netlink.h index 68a4ff46cb96..27e950f935b1 100644 --- a/drivers/w1/w1_netlink.h +++ b/drivers/w1/w1_netlink.h @@ -40,7 +40,7 @@ enum w1_netlink_message_types { struct w1_netlink_msg { __u8 type; - __u8 reserved; + __u8 status; __u16 len; union { __u8 id[8];