Applications can submit a set of commands in one packet to the kernel, and in some cases it is required such as reading the temperature sensor results. This adds an option W1_CN_BUNDLE to the flags of cn_msg to request the kernel to reply in one packet for efficiency.
The cn_msg flags now check for unknown flag values and return an error if one is seen. See "Proper handling of unknown flags in system calls" http://lwn.net/Articles/588444/ This corrects the ack values returned as per the protocol standard, namely the original ack for status messages and seq + 1 for all others such as the data returned from a read. Signed-off-by: David Fries <da...@fries.net> Some of the common variable names have been standardized as follows. struct cn_msg *cn struct w1_netlink_msg *msg struct w1_netlink_cmd *cmd struct w1_master *dev When an argument and a function scope variable would collide, add req_ to the argument. --- Documentation/connector/connector.txt | 2 +- Documentation/w1/w1.generic | 2 +- Documentation/w1/w1.netlink | 13 +- drivers/w1/w1.h | 8 - drivers/w1/w1_netlink.c | 649 ++++++++++++++++++++------------- drivers/w1/w1_netlink.h | 36 ++ 6 files changed, 447 insertions(+), 263 deletions(-) diff --git a/Documentation/connector/connector.txt b/Documentation/connector/connector.txt index e56abdb..f6215f9 100644 --- a/Documentation/connector/connector.txt +++ b/Documentation/connector/connector.txt @@ -118,7 +118,7 @@ acknowledge number MUST be the same + 1. If we receive a message and its sequence number is not equal to one we are expecting, then it is a new message. If we receive a message and its sequence number is the same as one we are expecting, but its -acknowledge is not equal to the acknowledge number in the original +acknowledge is not equal to the sequence number in the original message + 1, then it is a new message. Obviously, the protocol header contains the above id. diff --git a/Documentation/w1/w1.generic b/Documentation/w1/w1.generic index a31c5a2..b2033c6 100644 --- a/Documentation/w1/w1.generic +++ b/Documentation/w1/w1.generic @@ -82,7 +82,7 @@ driver - (standard) symlink to the w1 driver w1_master_add - Manually register a slave device w1_master_attempts - the number of times a search was attempted w1_master_max_slave_count - - the maximum slaves that may be attached to a master + - maximum number of slaves to search for at a time w1_master_name - the name of the device (w1_bus_masterX) w1_master_pullup - 5V strong pullup 0 enabled, 1 disabled w1_master_remove - Manually remove a slave device diff --git a/Documentation/w1/w1.netlink b/Documentation/w1/w1.netlink index 927a52c..ef27271 100644 --- a/Documentation/w1/w1.netlink +++ b/Documentation/w1/w1.netlink @@ -30,7 +30,7 @@ Protocol. W1_SLAVE_CMD userspace command for slave device (read/write/touch) - __u8 res - reserved + __u8 status - error indication from kernel __u16 len - size of data attached to this header data union { __u8 id[8]; - slave unique device id @@ -44,10 +44,14 @@ Protocol. __u8 cmd - command opcode. W1_CMD_READ - read command W1_CMD_WRITE - write command - W1_CMD_TOUCH - touch command - (write and sample data back to userspace) W1_CMD_SEARCH - search command W1_CMD_ALARM_SEARCH - alarm search command + W1_CMD_TOUCH - touch command + (write and sample data back to userspace) + W1_CMD_RESET - send bus reset + W1_CMD_SLAVE_ADD - add slave to kernel list + W1_CMD_SLAVE_REMOVE - remove slave from kernel list + W1_CMD_LIST_SLAVES - get slaves list from kernel __u8 res - reserved __u16 len - length of data for this command For read command data must be allocated like for write command @@ -87,8 +91,7 @@ format: id0 ... idN Each message is at most 4k in size, so if number of master devices - exceeds this, it will be split into several messages, - cn.seq will be increased for each one. + exceeds this, it will be split into several messages. W1 search and alarm search commands. request: diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h index 734dab7..56a49ba 100644 --- a/drivers/w1/w1.h +++ b/drivers/w1/w1.h @@ -203,7 +203,6 @@ enum w1_master_flags { * @search_id: allows continuing a search * @refcnt: reference count * @priv: private data storage - * @priv_size: size allocated * @enable_pullup: allows a strong pullup * @pullup_duration: time for the next strong pullup * @flags: one of w1_master_flags @@ -214,7 +213,6 @@ enum w1_master_flags { * @dev: sysfs device * @bus_master: io operations available * @seq: sequence number used for netlink broadcasts - * @portid: destination for the current netlink command */ struct w1_master { @@ -241,7 +239,6 @@ struct w1_master atomic_t refcnt; void *priv; - int priv_size; /** 5V strong pullup enabled flag, 1 enabled, zero disabled. */ int enable_pullup; @@ -260,11 +257,6 @@ struct w1_master struct w1_bus_master *bus_master; u32 seq; - /* port id to send netlink responses to. The value is temporarily - * stored here while processing a message, set after locking the - * mutex, zero before unlocking the mutex. - */ - u32 portid; }; /** diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c index a02704a..351a297 100644 --- a/drivers/w1/w1_netlink.c +++ b/drivers/w1/w1_netlink.c @@ -29,51 +29,247 @@ #include "w1_netlink.h" #if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE))) -void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg) + +#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) { - 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); + 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); +} - memset(buf, 0, sizeof(buf)); +/** + * 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)); - m->id.idx = CN_W1_IDX; - m->id.val = CN_W1_VAL; + packet.cn.id.idx = CN_W1_IDX; + packet.cn.id.val = CN_W1_VAL; - m->seq = dev->seq++; - m->len = sizeof(struct w1_netlink_msg); + packet.cn.seq = dev->seq++; + packet.cn.len = sizeof(*msg); - memcpy(w, msg, sizeof(struct w1_netlink_msg)); + memcpy(&packet.msg, msg, sizeof(*msg)); + packet.msg.len = 0; - cn_netlink_send(m, dev->portid, 0, GFP_KERNEL); + cn_netlink_send(&packet.cn, 0, 0, GFP_KERNEL); } static void w1_send_slave(struct w1_master *dev, u64 rn) { - struct cn_msg *msg = dev->priv; - struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1); - struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1); - int avail; + struct w1_cb_block *block = dev->priv; + struct w1_netlink_cmd *cache_cmd = block->cmd; u64 *data; - avail = dev->priv_size - cmd->len; + w1_reply_make_space(block, sizeof(*data)); - if (avail < 8) { - msg->ack++; - cn_netlink_send(msg, dev->portid, 0, GFP_KERNEL); - - msg->len = sizeof(struct w1_netlink_msg) + - sizeof(struct w1_netlink_cmd); - hdr->len = sizeof(struct w1_netlink_cmd); - cmd->len = 0; + /* Add cmd back if the packet was sent */ + if (!block->cmd) { + cache_cmd->len = 0; + w1_netlink_queue_cmd(block, cache_cmd); } - data = (void *)(cmd + 1) + cmd->len; + data = (u64 *)(block->cmd->data + block->cmd->len); *data = rn; - cmd->len += 8; - hdr->len += 8; - msg->len += 8; + 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) @@ -85,40 +281,15 @@ static void w1_found_send_slave(struct w1_master *dev, u64 rn) } /* Get the current slave list, or search (with or without alarm) */ -static int w1_get_slaves(struct w1_master *dev, - struct cn_msg *req_msg, struct w1_netlink_msg *req_hdr, - struct w1_netlink_cmd *req_cmd) +static int w1_get_slaves(struct w1_master *dev, struct w1_netlink_cmd *req_cmd) { - struct cn_msg *msg; - struct w1_netlink_msg *hdr; - struct w1_netlink_cmd *cmd; struct w1_slave *sl; - msg = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!msg) - return -ENOMEM; - - msg->id = req_msg->id; - msg->seq = req_msg->seq; - msg->ack = 0; - msg->len = sizeof(struct w1_netlink_msg) + - sizeof(struct w1_netlink_cmd); - - hdr = (struct w1_netlink_msg *)(msg + 1); - cmd = (struct w1_netlink_cmd *)(hdr + 1); - - hdr->type = W1_MASTER_CMD; - hdr->id = req_hdr->id; - hdr->len = sizeof(struct w1_netlink_cmd); - - cmd->cmd = req_cmd->cmd; - cmd->len = 0; - - dev->priv = msg; - dev->priv_size = PAGE_SIZE - msg->len - sizeof(struct cn_msg); + req_cmd->len = 0; + w1_netlink_queue_cmd(dev->priv, req_cmd); if (req_cmd->cmd == W1_CMD_LIST_SLAVES) { - __u64 rn; + u64 rn; mutex_lock(&dev->list_mutex); list_for_each_entry(sl, &dev->slist, w1_slave_entry) { memcpy(&rn, &sl->reg_num, sizeof(rn)); @@ -126,73 +297,26 @@ static int w1_get_slaves(struct w1_master *dev, } mutex_unlock(&dev->list_mutex); } else { - w1_search_process_cb(dev, cmd->cmd == W1_CMD_ALARM_SEARCH ? + w1_search_process_cb(dev, req_cmd->cmd == W1_CMD_ALARM_SEARCH ? W1_ALARM_SEARCH : W1_SEARCH, w1_found_send_slave); } - msg->ack = 0; - cn_netlink_send(msg, dev->portid, 0, GFP_KERNEL); - - dev->priv = NULL; - dev->priv_size = 0; - - kfree(msg); - return 0; } -static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr, - struct w1_netlink_cmd *cmd, u32 portid) -{ - 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, portid, 0, GFP_KERNEL); - - kfree(data); - - return err; -} - -static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg, - struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd) +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_send_read_reply(msg, hdr, cmd, dev->portid); + w1_netlink_queue_cmd(dev->priv, cmd); break; case W1_CMD_READ: w1_read_block(dev, cmd->data, cmd->len); - w1_send_read_reply(msg, hdr, cmd, dev->portid); + w1_netlink_queue_cmd(dev->priv, cmd); break; case W1_CMD_WRITE: w1_write_block(dev, cmd->data, cmd->len); @@ -206,14 +330,13 @@ static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg, } static int w1_process_command_addremove(struct w1_master *dev, - struct cn_msg *msg, struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd) { struct w1_slave *sl; int err = 0; struct w1_reg_num *id; - if (cmd->len != 8) + if (cmd->len != sizeof(*id)) return -EINVAL; id = (struct w1_reg_num *)cmd->data; @@ -241,7 +364,6 @@ static int w1_process_command_addremove(struct w1_master *dev, } static int w1_process_command_master(struct w1_master *dev, - struct cn_msg *req_msg, struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd) { int err = -EINVAL; @@ -254,13 +376,13 @@ static int w1_process_command_master(struct w1_master *dev, case W1_CMD_ALARM_SEARCH: case W1_CMD_LIST_SLAVES: mutex_unlock(&dev->bus_mutex); - err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd); + 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_msg, req_hdr, req_cmd); + err = w1_process_command_io(dev, req_cmd); break; case W1_CMD_RESET: err = w1_reset_bus(dev); @@ -269,8 +391,7 @@ static int w1_process_command_master(struct w1_master *dev, case W1_CMD_SLAVE_REMOVE: mutex_unlock(&dev->bus_mutex); mutex_lock(&dev->mutex); - err = w1_process_command_addremove(dev, req_msg, req_hdr, - req_cmd); + err = w1_process_command_addremove(dev, req_cmd); mutex_unlock(&dev->mutex); mutex_lock(&dev->bus_mutex); break; @@ -282,22 +403,21 @@ static int w1_process_command_master(struct w1_master *dev, 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) +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, msg, hdr, cmd); + return w1_process_command_io(sl->master, cmd); } -static int w1_process_command_root(struct cn_msg *msg, - struct w1_netlink_msg *mcmd, u32 portid) +static int w1_process_command_root(struct cn_msg *req_cn, u32 portid) { - struct w1_master *m; + struct w1_master *dev; struct cn_msg *cn; - struct w1_netlink_msg *w; + struct w1_netlink_msg *msg; u32 *id; cn = kmalloc(PAGE_SIZE, GFP_KERNEL); @@ -307,32 +427,30 @@ static int w1_process_command_root(struct cn_msg *msg, cn->id.idx = CN_W1_IDX; cn->id.val = CN_W1_VAL; - cn->seq = msg->seq; - cn->ack = 1; + cn->seq = req_cn->seq; + cn->ack = req_cn->seq + 1; cn->len = sizeof(struct w1_netlink_msg); - w = (struct w1_netlink_msg *)(cn + 1); + msg = (struct w1_netlink_msg *)cn->data; - w->type = W1_LIST_MASTERS; - w->status = 0; - w->len = 0; - id = (u32 *)(w + 1); + msg->type = W1_LIST_MASTERS; + msg->status = 0; + msg->len = 0; + id = (u32 *)msg->data; mutex_lock(&w1_mlock); - list_for_each_entry(m, &w1_masters, w1_master_entry) { + 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->ack++; cn->len = sizeof(struct w1_netlink_msg); - w->len = 0; - id = (u32 *)(w + 1); + msg->len = 0; + id = (u32 *)msg->data; } - *id = m->id; - w->len += sizeof(*id); + *id = dev->id; + msg->len += sizeof(*id); cn->len += sizeof(*id); id++; } - cn->ack = 0; cn_netlink_send(cn, portid, 0, GFP_KERNEL); mutex_unlock(&w1_mlock); @@ -340,100 +458,44 @@ static int w1_process_command_root(struct cn_msg *msg, return 0; } -static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg, - struct w1_netlink_cmd *rcmd, int portid, 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, portid, 0, GFP_KERNEL); - kfree(cmsg); - - return error; -} - -/* Bundle together a reference count, the full message, and broken out - * commands to be executed on each w1 master kthread in one memory allocation. - */ -struct w1_cb_block { - atomic_t refcnt; - u32 portid; /* Sending process port ID */ - struct cn_msg msg; - /* cn_msg data */ - /* one or more variable length struct w1_cb_node */ -}; -struct w1_cb_node { - struct w1_async_cmd async; - /* pointers within w1_cb_block and msg data */ - struct w1_cb_block *block; - struct w1_netlink_msg *m; - struct w1_slave *sl; - struct w1_master *dev; -}; - 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->m->len; - u8 *cmd_data = node->m->data; + u16 mlen = node->msg->len; + u16 len; int err = 0; struct w1_slave *sl = node->sl; - struct w1_netlink_cmd *cmd = NULL; + struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)node->msg->data; mutex_lock(&dev->bus_mutex); - dev->portid = node->block->portid; + dev->priv = node->block; if (sl && w1_reset_select_slave(sl)) err = -ENODEV; + node->block->cur_msg = node->msg; while (mlen && !err) { - cmd = (struct w1_netlink_cmd *)cmd_data; - if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) { err = -E2BIG; break; } if (sl) - err = w1_process_command_slave(sl, &node->block->msg, - node->m, cmd); + err = w1_process_command_slave(sl, cmd); else - err = w1_process_command_master(dev, &node->block->msg, - node->m, cmd); + err = w1_process_command_master(dev, cmd); + w1_netlink_check_send(node->block); - w1_netlink_send_error(&node->block->msg, node->m, cmd, - node->block->portid, err); + w1_netlink_queue_status(node->block, node->msg, cmd, err); err = 0; - cmd_data += cmd->len + sizeof(struct w1_netlink_cmd); - mlen -= cmd->len + sizeof(struct w1_netlink_cmd); + len = sizeof(*cmd) + cmd->len; + cmd = (struct w1_netlink_cmd *)((u8 *)cmd + len); + mlen -= len; } if (!cmd || err) - w1_netlink_send_error(&node->block->msg, node->m, cmd, - node->block->portid, 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 @@ -442,99 +504,186 @@ static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd) w1_unref_slave(sl); else atomic_dec(&dev->refcnt); - dev->portid = 0; + dev->priv = NULL; mutex_unlock(&dev->bus_mutex); mutex_lock(&dev->list_mutex); list_del(&async_cmd->async_entry); mutex_unlock(&dev->list_mutex); - if (atomic_sub_return(1, &node->block->refcnt) == 0) - kfree(node->block); + 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 *msg, struct netlink_skb_parms *nsp) +static void w1_cn_callback(struct cn_msg *cn, struct netlink_skb_parms *nsp) { - struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1); + 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 = msg->len; + msg_len = cn->len; while (msg_len && !err) { - if (m->len + sizeof(struct w1_netlink_msg) > msg_len) { + if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) { err = -E2BIG; break; } - if (m->type == W1_MASTER_CMD || m->type == W1_SLAVE_CMD) + /* 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) + m->len; - m = (struct w1_netlink_msg *)(((u8 *)m) + - sizeof(struct w1_netlink_msg) + m->len); + msg_len -= sizeof(struct w1_netlink_msg) + msg->len; + msg = (struct w1_netlink_msg *)(((u8 *)msg) + + sizeof(struct w1_netlink_msg) + msg->len); } - m = (struct w1_netlink_msg *)(msg + 1); + msg = (struct w1_netlink_msg *)(cn + 1); if (node_count) { - /* msg->len doesn't include itself */ - long size = sizeof(struct w1_cb_block) + msg->len + - node_count*sizeof(struct w1_cb_node); - block = kmalloc(size, GFP_KERNEL); + int size; + u16 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) { - w1_netlink_send_error(msg, m, NULL, nsp->portid, - -ENOMEM); + /* 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->msg, msg, sizeof(*msg) + msg->len); - node = (struct w1_cb_node *)((u8 *)block->msg.data + msg->len); + 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 = msg->len; + msg_len = cn->len; while (msg_len && !err) { dev = NULL; sl = NULL; - if (m->len + sizeof(struct w1_netlink_msg) > msg_len) { + if (msg->len + sizeof(struct w1_netlink_msg) > msg_len) { err = -E2BIG; break; } /* execute on this thread, no need to process later */ - if (m->type == W1_LIST_MASTERS) { - err = w1_process_command_root(msg, m, nsp->portid); + 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 (!m->len) { + if (!msg->len) { err = -EPROTO; goto out_cont; } - /* both search calls take reference counts */ - 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((struct w1_reg_num *)m->id.id); + /* 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 { printk(KERN_NOTICE - "%s: msg: %x.%x, wrong type: %u, len: %u.\n", - __func__, msg->id.idx, msg->id.val, - m->type, m->len); + "%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; } @@ -549,8 +698,8 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) atomic_inc(&block->refcnt); node->async.cb = w1_process_cb; node->block = block; - node->m = (struct w1_netlink_msg *)((u8 *)&block->msg + - (size_t)((u8 *)m - (u8 *)msg)); + node->msg = (struct w1_netlink_msg *)((u8 *)&block->request_cn + + (size_t)((u8 *)msg - (u8 *)cn)); node->sl = sl; node->dev = dev; @@ -561,11 +710,15 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) ++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(msg, m, NULL, nsp->portid, err); - msg_len -= sizeof(struct w1_netlink_msg) + m->len; - m = (struct w1_netlink_msg *)(((u8 *)m) + - sizeof(struct w1_netlink_msg) + m->len); + 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. @@ -573,8 +726,8 @@ out_cont: if (err == -ENODEV) err = 0; } - if (block && atomic_sub_return(1, &block->refcnt) == 0) - kfree(block); + if (block) + w1_unref_block(block); } int w1_init_netlink(void) @@ -591,7 +744,7 @@ void w1_fini_netlink(void) cn_del_callback(&w1_id); } #else -void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg) +void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *cn) { } diff --git a/drivers/w1/w1_netlink.h b/drivers/w1/w1_netlink.h index 1e9504e..c99a9ce 100644 --- a/drivers/w1/w1_netlink.h +++ b/drivers/w1/w1_netlink.h @@ -28,6 +28,17 @@ #include "w1.h" /** + * enum w1_cn_msg_flags - bitfield flags for struct cn_msg.flags + * + * @W1_CN_BUNDLE: Request bundling replies into fewer messagse. Be prepared + * to handle multiple struct cn_msg, struct w1_netlink_msg, and + * struct w1_netlink_cmd in one packet. + */ +enum w1_cn_msg_flags { + W1_CN_BUNDLE = 1, +}; + +/** * enum w1_netlink_message_types - message type * * @W1_SLAVE_ADD: notification that a slave device was added @@ -49,6 +60,19 @@ enum w1_netlink_message_types { W1_LIST_MASTERS, }; +/** + * struct w1_netlink_msg - holds w1 message type, id, and result + * + * @type: one of enum w1_netlink_message_types + * @status: kernel feedback for success 0 or errno failure value + * @len: length of data following w1_netlink_msg + * @id: union holding master bus id (msg.id) and slave device id (id[8]). + * @data: start address of any following data + * + * The base message structure for w1 messages over netlink. + * The netlink connector data sequence is, struct nlmsghdr, struct cn_msg, + * then one or more struct w1_netlink_msg (each with optional data). + */ struct w1_netlink_msg { __u8 type; @@ -66,6 +90,7 @@ struct w1_netlink_msg /** * enum w1_commands - commands available for master or slave operations + * * @W1_CMD_READ: read len bytes * @W1_CMD_WRITE: write len bytes * @W1_CMD_SEARCH: initiate a standard search, returns only the slave @@ -93,6 +118,17 @@ enum w1_commands { W1_CMD_MAX }; +/** + * struct w1_netlink_cmd - holds the command and data + * + * @cmd: one of enum w1_commands + * @res: reserved + * @len: length of data following w1_netlink_cmd + * @data: start address of any following data + * + * One or more struct w1_netlink_cmd is placed starting at w1_netlink_msg.data + * each with optional data. + */ struct w1_netlink_cmd { __u8 cmd; -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
