ircd::m::resource: Obtain version information for request if possible.

Author: jevolk

include/ircd/m/resource.h

@@ -47,6 +47,7 @@ struct ircd::m::resource::request
 	pair<string_view> authorization;   // proffering any
 	string_view access_token;          // proffering user
 	m::request::x_matrix x_matrix;     // proferring server
+	pair<string_view> version;         // enumeration
 
 	string_view node_id;               // authenticated server
 	m::user::id user_id;               // authenticated user or bridge pup

matrix/resource.cc

@@ -14,10 +14,11 @@ namespace ircd::m
 	extern conf::item<bool> x_matrix_verify_origin;
 	extern conf::item<bool> x_matrix_verify_destination;
 
+	static void cache_warm_origin(const resource::request &);
+	static pair<string_view> parse_version(const resource::request &);
 	static string_view authenticate_bridge(const resource::method &, const client &, resource::request &);
 	static user::id authenticate_user(const resource::method &, const client &, resource::request &);
 	static string_view authenticate_node(const resource::method &, const client &, resource::request &);
-	static void cache_warm_origin(const resource::request &);
 }
 
 decltype(ircd::m::cache_warmup_time)
@@ -154,6 +155,10 @@ ircd::m::resource::request::request(const method &method,
 		m::request::x_matrix{authorization.first, authorization.second}:
 		m::request::x_matrix{}
 }
+,version
+{
+	parse_version(*this)
+}
 ,node_id
 {
 	// Server X-Matrix header verified here. Similar to client auth, origin
@@ -391,6 +396,30 @@ catch(const std::exception &e)
 	};
 }
 
+ircd::pair<ircd::string_view>
+ircd::m::parse_version(const m::resource::request &request)
+{
+	const auto &user_agent
+	{
+		request.head.user_agent
+	};
+
+	const auto &[primary, info]
+	{
+		split(user_agent, ' ')
+	};
+
+	const auto &[name, version]
+	{
+		split(primary, '/')
+	};
+
+	return
+	{
+		name, version
+	};
+}
+
 /// We can smoothly warmup some memory caches after daemon startup as the
 /// requests trickle in from remote servers. This function is invoked after
 /// a remote contacts and reveals its identity with the X-Matrix verification.