net: context: Add PRIORITY option support

Add context option support and implement PRIORITY option that
can be used to classify the network traffic to different trafic
classes according to said priority value.

Signed-off-by: Jukka Rissanen <[email protected]>

.known-issues/doc/networking.conf

@@ -52,3 +52,9 @@
 ^(?P=filename):(?P=lineno): WARNING: Invalid definition: Expected end of definition. \[error at [0-9]+]
 ^.*ieee802154_req_params.__unnamed__
 ^[- \t]*\^
+#
+# include/net/net_context.h
+#
+^(?P<filename>[-._/\w]+/doc/api/networking.rst):(?P<lineno>[0-9]+): WARNING: Invalid definition: Expected end of definition. \[error at [0-9]+]
+^.*net_context.options
+^[- \t]*\^

include/net/net_context.h

@@ -210,6 +210,14 @@ struct net_context {
 	 */
 	struct sockaddr remote;
 
+	/** Option values */
+	struct {
+#if defined(CONFIG_NET_CONTEXT_PRIORITY)
+		/** Priority of the network data sent via this net_context */
+		u8_t priority;
+#endif
+	} options;
+
 	/** Connection handle */
 	struct net_conn_handle *conn_handler;
 
@@ -769,6 +777,38 @@ int net_context_recv(struct net_context *context,
 int net_context_update_recv_wnd(struct net_context *context,
 				s32_t delta);
 
+enum net_context_option {
+	NET_OPT_PRIORITY = 1,
+};
+
+/**
+ * @brief Set an connection option for this context.
+ *
+ * @param context The network context to use.
+ * @param option Option to set
+ * @param value Option value
+ * @param len Option length
+ *
+ * @return 0 if ok, <0 if error
+ */
+int net_context_set_option(struct net_context *context,
+			   enum net_context_option option,
+			   const void *value, size_t len);
+
+/**
+ * @brief Get connection option value for this context.
+ *
+ * @param context The network context to use.
+ * @param option Option to set
+ * @param value Option value
+ * @param len Option length (returned to caller)
+ *
+ * @return 0 if ok, <0 if error
+ */
+int net_context_get_option(struct net_context *context,
+			   enum net_context_option option,
+			   void *value, size_t *len);
+
 /**
  * @typedef net_context_cb_t
  * @brief Callback used while iterating over network contexts

subsys/net/ip/Kconfig

@@ -262,6 +262,13 @@ config NET_CONTEXT_CHECK
 	  If you know that the options passed to net_context...() functions
 	  are ok, then you can disable the checks to save some memory.
 
+config NET_CONTEXT_PRIORITY
+	bool "Add priority support to net_context"
+	default n
+	help
+	  It is possible to prioritize network traffic. This requires
+	  also traffic class support to work as expected.
+
 config NET_TEST
 	bool "Network Testing"
 	default n

subsys/net/ip/net_context.c

@@ -2462,6 +2462,81 @@ int net_context_update_recv_wnd(struct net_context *context,
 	return -EPROTOTYPE;
 #endif
 }
+
+static int set_context_priority(struct net_context *context,
+				const void *value, size_t len)
+{
+#if defined(CONFIG_NET_CONTEXT_PRIORITY)
+	if (len > sizeof(u8_t)) {
+		return -EINVAL;
+	}
+
+	context->options.priority = *((u8_t *)value);
+
+	return 0;
+#else
+	return -ENOTSUP;
+#endif
+}
+
+static int get_context_priority(struct net_context *context,
+				void *value, size_t *len)
+{
+#if defined(CONFIG_NET_CONTEXT_PRIORITY)
+	*((u8_t *)value) = context->options.priority;
+
+	if (len) {
+		*len = sizeof(u8_t);
+	}
+
+	return 0;
+#else
+	return -ENOTSUP;
+#endif
+}
+
+int net_context_set_option(struct net_context *context,
+			   enum net_context_option option,
+			   const void *value, size_t len)
+{
+	int ret = 0;
+
+	NET_ASSERT(context);
+
+	if (!PART_OF_ARRAY(contexts, context)) {
+		return -EINVAL;
+	}
+
+	switch (option) {
+	case NET_OPT_PRIORITY:
+		ret = set_context_priority(context, value, len);
+		break;
+	}
+
+	return ret;
+}
+
+int net_context_get_option(struct net_context *context,
+			    enum net_context_option option,
+			    void *value, size_t *len)
+{
+	int ret = 0;
+
+	NET_ASSERT(context);
+
+	if (!PART_OF_ARRAY(contexts, context)) {
+		return -EINVAL;
+	}
+
+	switch (option) {
+	case NET_OPT_PRIORITY:
+		ret = get_context_priority(context, value, len);
+		break;
+	}
+
+	return ret;
+}
+
 void net_context_foreach(net_context_cb_t cb, void *user_data)
 {
 	int i;