Protocol: changes to interface and some re-implementation.

Most functions exposed in protocol.h take a connection descriptor
(cd_t) as first argument. This allows for multiple connections. Device
gets only one connection which means that cd_t is effectively 0 all
the time.

Additionaly, any function that actually does anything with a
connection descriptor instead of just passing it to another function
must be implemented separately in device and daemon.

Signed-off-by: Ramūnas Mažeikis <ramunasnezinomas@gmail.com>

1 files changed, 43 insertions, 15 deletions

diff --git a/include/protocol.h b/include/protocol.h
index ac83154..60d31ea 100644
--- a/include/protocol.h
+++ b/include/protocol.h
@@ -23,9 +23,17 @@
 
 #include <errno.h>
 
-#define	E_TLV_OVERFLOW	(1 << 0)
-#define E_UNKNOWN_TYPE	(1 << 1)
+#define	E_TLV_OVERFLOW	        (1 << 0)
+#define E_UNKNOWN_TYPE	        (1 << 1)
+#define E_IVALID_DESCRIPTOR     (1 << 2)
 
+/**
+ * Regular packets contain tlv's defined by tlv_type.
+ *
+ * Hearbeat packet tell daemon that device is still alive and listening.
+ *
+ * Discovery packets are used for what they say.
+ */
 enum packet_type {
 	REGURAL,
 	HEARTBEAT,
@@ -33,6 +41,11 @@ enum packet_type {
 };
 
 /**
+ * Connection descriptor.
+ */
+typedef unsigned int cd_t;
+
+/**
  * Message sequence number since beggining of sesssion.
  *
  * Mainly used for identifying lost messages.
@@ -40,13 +53,16 @@ enum packet_type {
 typedef unsigned int msg_idx_t;
 
 enum tlv_type {
-	/** NULL-terminated string. */
+	/**
+	 * NULL-terminated string. To be put in a queue to display on the
+	 * screen.
+	 */
 	TEXT,
 
 	/** Fixed point. 1 decimal digit of precision. */
 	FPI1,
 
-	/** Literally time_t*/
+	/** Literally time_t */
 	TIMESTAMP,
 
 	/** Represents a request for lost message. Data is unsigned integer
@@ -54,51 +70,63 @@ enum tlv_type {
 	 */
 	REQUEST,
 
-	/** Response to request. Begins with unsigned integer that represents
+	/**
+	 * Response to request. Begins with unsigned integer that represents
 	 * which message is being repeated and the actual null-terminated
 	 * message after that.
 	 */
 	REPLY,
 
-	/** UUID that represents a particular device.
+	/**
+	 * UUID that represents a particular device.
 	 */
 	UUID
 };
 
+/**
+ * Packet data itself is a special type of tlv. A packet is either regular,
+ * hearbeat or discovery.
+ */
 struct packet_data {
 	enum packet_type type;
 	size_t packet_size;
 	char *data;	/* Bytes representing tlv's */
 };
 
+/**
+ * Literally type-length-value
+ * */
 struct tlv {
 	enum tlv_type type;
 	size_t length;
 	void *data;
 };
 
-/*
+/**
  * Reads last packets received, parses and stores them to be later retreived
  * via get_tlv.
  * */
-void get_last_data(void);
+void get_last_data(cd_t connection);
 
-/* Returns tlv's parsed by get_last_data. Returned tlv is only valid until
+/** Returns tlv's parsed by get_last_data. Returned tlv is only valid until
  * next call to get_tlv.
  * */
 struct tlv * get_tlv(void);
 
-/* Any modifications made to the pending outgoing packet are nullified.
+/**
+ * Any modifications made to the pending outgoing packet are nullified.
  * */
-void clear_data(void);
+void clear_data(cd_t connection);
 
-/* Appends data to the next packet to be sent. Type of data is determined by
+/**
+ * Appends data to the next packet to be sent. Type of data is determined by
  * enum tlv_type.
  * */
-int push_data(const char *data, enum tlv_type);
+int push_data(cd_t connection, const char *data, enum tlv_type);
 
-/* Sends packet towards the other end.
+/**
+ * Sends packet towards the other end.
  * */
-void flush_data(void);
+void flush_data(cd_t connection);
 
 #endif /* PROTOCOL_H_INCLUDED */