ircd::net: Use "service" string in net::hostport.

include/ircd/net/hostport.h

@@ -26,9 +26,13 @@ namespace ircd::net
 {
 	struct hostport;
 
-	uint16_t port(const hostport &);
+	const uint16_t &port(const hostport &);
 	const string_view &host(const hostport &);
+	const string_view &service(const hostport &);
+
+	uint16_t &port(hostport &);
 	string_view &host(hostport &);
+
 	string_view string(const mutable_buffer &out, const hostport &);
 }
 
@@ -38,42 +42,63 @@ namespace ircd
 	using net::host;
 }
 
-/// This structure holds a hostname and port usually fresh from user input
-/// intended for resolution.
+/// This structure holds a hostname and service or port usually fresh from
+/// user input intended for resolution.
 ///
-/// The host can be specified as a hostname or hostname:port string. If no
-/// port argument is specified and no port is present in the host string
-/// then 8448 is assumed.
+/// The host can be passed to the constructor as a hostname or hostname:port
+/// string.
+///
+/// The service field is a string which will trigger an SRV query during
+/// resolution and/or be used to figure out the port number. If it is omitted
+/// then the numerical port should be specified directly. If it exists then
+/// the numerical port will only be used as a fallback, and an SRV response
+/// with an alternative port may even override both the host and given
+/// numerical port here.
 ///
 struct ircd::net::hostport
 {
 	string_view host {"0.0.0.0"};
-	string_view port {"8448"};
-	uint16_t portnum {0};
+	string_view service {"matrix"};
+	uint16_t port {8448};
 
 	bool operator!() const;
 
-	hostport(const string_view &host, const string_view &port)
-	:host{host}
-	,port{port}
-	{}
-
-	hostport(const string_view &host, const uint16_t &portnum)
-	:host{host}
-	,port{}
-	,portnum{portnum}
-	{}
-
-	hostport(const string_view &amalgam)
-	:host{rsplit(amalgam, ':').first}
-	,port{amalgam != host? rsplit(amalgam, ':').second : "8448"}
-	{}
-
+	hostport(const string_view &host, const string_view &service);
+	hostport(const string_view &host, const uint16_t &port);
+	hostport(const string_view &amalgam);
 	hostport() = default;
 
 	friend std::ostream &operator<<(std::ostream &, const hostport &);
 };
 
+inline
+ircd::net::hostport::hostport(const string_view &host,
+                              const string_view &service)
+:host{host}
+,service{service}
+{}
+
+inline
+ircd::net::hostport::hostport(const string_view &host,
+                              const uint16_t &port)
+:host{host}
+,service{}
+,port{port}
+{}
+
+inline
+ircd::net::hostport::hostport(const string_view &amalgam)
+:host
+{
+	rsplit(amalgam, ':').first
+}
+,service{}
+,port
+{
+	amalgam != host? lex_cast<uint16_t>(rsplit(amalgam, ':').second) : uint16_t(0)
+}
+{}
+
 inline bool
 ircd::net::hostport::operator!()
 const
@@ -88,16 +113,26 @@ ircd::net::host(hostport &hp)
 	return hp.host;
 }
 
+inline uint16_t &
+ircd::net::port(hostport &hp)
+{
+	return hp.port;
+}
+
+inline const ircd::string_view &
+ircd::net::service(const hostport &hp)
+{
+	return hp.service;
+}
+
 inline const ircd::string_view &
 ircd::net::host(const hostport &hp)
 {
 	return hp.host;
 }
 
-inline uint16_t
+inline const uint16_t &
 ircd::net::port(const hostport &hp)
 {
-	return hp.portnum? hp.portnum:
-	       hp.port?    lex_cast<uint16_t>(hp.port):
-	       0;
+	return hp.port;
 }

ircd/net.cc

@@ -2850,15 +2850,22 @@ ircd::string_view
 ircd::net::string(const mutable_buffer &buf,
                   const hostport &hp)
 {
-	const auto len
-	{
-		fmt::sprintf
+	if(empty(service(hp)))
+		return fmt::sprintf
 		{
 			buf, "%s:%u", host(hp), port(hp)
-		}
-	};
+		};
 
-	return { data(buf), size_t(len) };
+	if(port(hp) == 0)
+		return fmt::sprintf
+		{
+			buf, "%s (%s)", host(hp), service(hp)
+		};
+
+	return fmt::sprintf
+	{
+		buf, "%s:%u (%s)", host(hp), port(hp), service(hp)
+	};
 }
 
 ///////////////////////////////////////////////////////////////////////////////