w1: fixes and bundling replies

index 5234964..a02704a 100644
@@ -300,12 +300,6 @@ static int w1_process_command_root(struct cn_msg *msg,
 	struct w1_netlink_msg *w;
 	u32 *id;
 
-	if (mcmd->type != W1_LIST_MASTERS) {
-		printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
-			__func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
-		return -EPROTO;
-	}
-
 	cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!cn)
 		return -ENOMEM;

@@ -441,6 +435,9 @@ static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
 		w1_netlink_send_error(&node->block->msg, node->m, cmd,
 			node->block->portid, err);
 
+	/* ref taken in w1_search_slave or w1_search_master_id when building
+	 * the block
+	 */
 	if (sl)
 		w1_unref_slave(sl);
 	else

@@ -503,30 +500,42 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 
 	msg_len = msg->len;
 	while (msg_len && !err) {
-		struct w1_reg_num id;
-		u16 mlen = m->len;
 
 		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;
 		}
 
+		/* execute on this thread, no need to process later */
+		if (m->type == W1_LIST_MASTERS) {
+			err = w1_process_command_root(msg, m, nsp->portid);
+			goto out_cont;
+		}
+
+		/* All following message types require additional data,
+		 * check here before references are taken.
+		 */
+		if (!m->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(&id);
+			sl = w1_search_slave((struct w1_reg_num *)m->id.id);
 			if (sl)
 				dev = sl->master;
 		} else {
-			err = w1_process_command_root(msg, m, nsp->portid);
+			printk(KERN_NOTICE
+				"%s: msg: %x.%x, wrong type: %u, len: %u.\n",
+				__func__, msg->id.idx, msg->id.val,
+				m->type, m->len);
+			err = -EPROTO;
 			goto out_cont;
 		}
 

@@ -536,8 +545,6 @@ static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 		}
 
 		err = 0;
-		if (!mlen)
-			goto out_cont;
 
 		atomic_inc(&block->refcnt);
 		node->async.cb = w1_process_cb;

@@ -557,7 +564,8 @@ out_cont:
 		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);
+		m = (struct w1_netlink_msg *)(((u8 *)m) +
+			sizeof(struct w1_netlink_msg) + m->len);
 
 		/*
 		 * Let's allow requests for nonexisting devices.

index b14f1d3..f612d68 100644
@@ -43,6 +43,8 @@ static struct cn_dev cdev;
 static int cn_already_initialized;
 
 /*
+ * Sends mult (multiple) cn_msg at a time.
+ *
  * msg->seq and msg->ack are used to determine message genealogy.
  * When someone sends message it puts there locally unique sequence
  * and random acknowledge numbers.  Sequence number may be copied into

@@ -62,10 +64,13 @@ static int cn_already_initialized;
  * the acknowledgement number in the original message + 1, then it is
  * a new message.
  *
+ * If msg->len != len, then additional cn_msg messages are expected following
+ * the first msg.
+ *
  * The message is sent to, the portid if given, the group if given, both if
  * both, or if both are zero then the group is looked up and sent there.
  */
-int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
+int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group,
 	gfp_t gfp_mask)
 {
 	struct cn_callback_entry *__cbq;

@@ -98,7 +103,7 @@ int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
 	if (!portid && !netlink_has_listeners(dev->nls, group))
 		return -ESRCH;
 
-	size = sizeof(*msg) + msg->len;
+	size = sizeof(*msg) + len;
 
 	skb = nlmsg_new(size, gfp_mask);
 	if (!skb)

@@ -121,6 +126,14 @@ int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
 					 gfp_mask);
 	return netlink_unicast(dev->nls, skb, portid, !(gfp_mask&__GFP_WAIT));
 }
+EXPORT_SYMBOL_GPL(cn_netlink_send_mult);
+
+/* same as cn_netlink_send_mult except msg->len is used for len */
+int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
+	gfp_t gfp_mask)
+{
+	return cn_netlink_send_mult(msg, msg->len, portid, __group, gfp_mask);
+}
 EXPORT_SYMBOL_GPL(cn_netlink_send);
 
 /*

index be9c4747..f8fe863 100644
@@ -71,6 +71,7 @@ struct cn_dev {
 int cn_add_callback(struct cb_id *id, const char *name,
 		    void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
 void cn_del_callback(struct cb_id *);
+int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 group, gfp_t gfp_mask);
 int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
 
 int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,

index 734dab7..56a49ba 100644
@@ -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;
 };
 
 /**

894 lines not on this page · raw message

index 1e9504e..c99a9ce 100644
@@ -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;