start with the generic protocol state machine

include/account_settings_common.h

@@ -43,6 +43,8 @@ typedef enum _AS_FLAGS
 //! Combination of protocol, socket type & authentication type
 typedef enum _AS_ACCESS
 {
+	AS_ACCESS_UNKNOWN     = 0,        ///< unknown / undetermined authentication type. Used as error value.
+
 	/// protocols
 	AS_PROTO_POP3         = 0x00011,  ///< incoming
 	AS_PROTO_IMAP         = 0x00012,  ///< incoming

src/from_heuristics.cc

@@ -14,21 +14,92 @@ public:
 	{}
 };
 
+
 namespace
 {
+	namespace bio = boost::asio;
+	using bio::ip::tcp;
+
 	// TODO: implement!
 	class Protocol
 	{
 	public:
-		Protocol() = default;
+		Protocol() {}
+		virtual ~Protocol() {}
+		
+		/// (re)initialize the protocol and thet the AS_Server to initial state
+		virtual void init(AS_Server& ass) = 0;
+		
+		/// say something to the server. if nothing to say in this state, it returns empty string
+		virtual std::string put() = 0;
+		
+		/// return true if guessing was successful
+		virtual bool get(const std::string& s) = 0;
 	};
 
 
-	AS_Server probe_server(const std::string& domain, std::initializer_list<std::string> names, Protocol p=Protocol() )
+	class Imap : public Protocol
 	{
-		AS_Server ass { "", -1, AS_ACCESS(-1), "" };
+	public:
+		Imap() {}
+		virtual ~Imap() {}
+		virtual void init(AS_Server& ass) override { /* TODO: implement! */ }
+		virtual std::string put() override { return ""; }
+		virtual bool get(const std::string& s) override { return s.empty(); }
+	};
+
+
+	AS_Server pingpong(const std::string& server, int port, Protocol& p)
+	{
+		AS_Server ass{ "", -1, AS_ACCESS_UNKNOWN, "" };
+		try{
+			std::vector<char> buffer(2048);
+			bio::io_service ios;
+			tcp::resolver res(ios);
+			tcp::resolver::query query( server, std::to_string(port) );
+			for(auto iter = res.resolve(query); iter != tcp::resolver::iterator(); ++iter)
+			{
+				p.init(ass);
+				tcp::socket s(ios);
+				bio::connect(s, iter);
+				boost::system::error_code err;
+				
+				while(ass.access == AS_ACCESS_UNKNOWN)
+				{
+					const std::string output = p.put();
+					if(!output.empty())
+					{
+						bio::write(s, bio::buffer(output), err);
+					}
+					
+					const size_t length = s.read_some( boost::asio::buffer(buffer), err);
+					if(!err || err == bio::error::eof)
+					{
+						if( p.get( std::string( buffer.data(), buffer.data()+length) ) )
+						{
+							return ass;
+						}
+					}
+				}
+			}
+		}catch(std::runtime_error&) { /* just return what we have so far */ }
 		
-		throw protocol_error{};
+		return ass;
+	}
+
+
+	AS_Server probe_server(const std::string& domain, std::initializer_list<std::string> names, std::initializer_list<int> ports, Protocol& p )
+	{
+		for(auto port : ports)
+		for(auto name : names)
+		{
+			const std::string server = domain + "." + name;
+			const AS_Server ass = pingpong(server, port, p);
+			if(ass.access != AS_ACCESS_UNKNOWN)
+				return ass;
+		}
+		
+		return AS_Server{ "", -1, AS_ACCESS_UNKNOWN, "" };
 	}
 
 } //end of anonymous namespace
@@ -43,7 +114,8 @@ AccountSettings* get_settings_from_heuristics(AccountSettings* as, const std::st
 
 //	fprintf(stderr, "== IMAP ==\n");
 	try{
-		as->incoming = probe_server( domain, {"imap", "mail", "imaps", "imapmail", "imap-mail", "mx", "", "mbox",} );
+		Imap imap_protocol;
+		as->incoming = probe_server( domain, {"imap", "mail", "imaps", "imapmail", "imap-mail", "mx", "", "mbox"}, {143, 993}, imap_protocol );
 	}catch( const protocol_error& )
 	{
 		// ignore protocol errors
@@ -51,7 +123,8 @@ AccountSettings* get_settings_from_heuristics(AccountSettings* as, const std::st
 
 //	fprintf(stderr, "== SMTP ==\n");
 	try{
-		as->outgoing = probe_server( domain, {"smtp", "mail", "smtps", "smtpmail", "smtp-mail", "mx", "", "smtpauth",} );
+		Imap smtp_protocol;
+		as->outgoing = probe_server( domain, {"smtp", "mail", "smtps", "smtpmail", "smtp-mail", "mx", "", "smtpauth",}, {25, 587, 465}, smtp_protocol );
 	}catch( const protocol_error& )
 	{
 		// ignore protocol errors