net: tcp: Remove net_tcp_unref()

There is a pending TODO regarding unifying net_tcp_unref() and
net_tcp_put(). Given that net_tcp_unref() is no longer used by the upper
layer (it should only use get/put APIs), the function can be removed
from external TCP API, as referencing/dereferencing is now only used
internally by the TCP stack.

Signed-off-by: Robert Lubos <[email protected]>

Author: rlubos

subsys/net/ip/tcp.c

@@ -463,19 +463,6 @@ static int tcp_conn_unref(struct tcp *conn)
 	return ref_count;
 }
 
-int net_tcp_unref(struct net_context *context)
-{
-	int ref_count = 0;
-
-	NET_DBG("context: %p, conn: %p", context, context->tcp);
-
-	if (context->tcp) {
-		ref_count = tcp_conn_unref(context->tcp);
-	}
-
-	return ref_count;
-}
-
 #if CONFIG_NET_TCP_LOG_LEVEL >= LOG_LEVEL_DBG
 #define tcp_conn_close(conn, status)				\
 	tcp_conn_close_debug(conn, status, __func__, __LINE__)
@@ -2580,7 +2567,7 @@ int net_tcp_put(struct net_context *context)
 
 	k_mutex_unlock(&conn->lock);
 
-	net_tcp_unref(context);
+	tcp_conn_unref(conn);
 
 	return 0;
 }

subsys/net/ip/tcp.h

@@ -52,17 +52,6 @@ int net_tcp_get(struct net_context *context);
  */
 int net_tcp_put(struct net_context *context);
 
-/* TODO: Clarify what happens if the ref count goes to 0 */
-/**
- * @brief Unref a TCP connection
- *
- * @param context Network context
- *
- * @return 0 if successful, < 0 on error
- */
-int net_tcp_unref(struct net_context *context);
-/* TODO: Merge net_tcp_unref() and net_tcp_put() */
-
 /**
  * @brief Listen for an incoming TCP connection
  *

subsys/net/ip/tcp_internal.h

@@ -106,24 +106,6 @@ static inline int net_tcp_get(struct net_context *context)
 }
 #endif
 
-/**
- * @brief Unref TCP parts of a context
- *
- * @param context Network context
- *
- * @return 0 if successful, < 0 on error
- */
-#if defined(CONFIG_NET_NATIVE_TCP)
-int net_tcp_unref(struct net_context *context);
-#else
-static inline int net_tcp_unref(struct net_context *context)
-{
-	ARG_UNUSED(context);
-
-	return -EPROTONOSUPPORT;
-}
-#endif
-
 /**
  * @brief Connect TCP connection
  *