InSim Relay source

For more information go to http://www.lfsforum.net/showthread.php?t=30740

// InSimRelay for LFS InSim version 4 (LFS 0.5X and up)
//
// The Relay code below can be seen as an extension to the regular 
// InSim protocol, as the packets are constructed in the same
// manner as regular InSim packets.
//
// Connect your client to isrelay.lfs.net:47474 with TCP
// After you are connected you can request a hostlist, so you can see
// which hosts you can connect to.
// Then you can send a packet to the Relay to select a host. After that
// the Relay will send you all insim data from that host.

// Some hosts require a spectator password in order to be selectable.

// You do not need to specify a spectator password if you use a valid administrator password.

// If you connect with an administrator password, you can send just about every
// regular InSim packet there is available in LFS, just like as if you were connected
// to the host directly. For a full list, see end of document.



// Packet types used for the Relay

#define IRP_ARQ		250	// Send : request if we are host admin (after connecting to a host)
#define IRP_ARP		251	// Receive : replies if you are admin (after connecting to a host)
#define IRP_HLR		252	// Send : To request a hostlist
#define IRP_HOS		253	// Receive : Hostlist info
#define IRP_SEL		254	// Send : To select a host
#define IRP_ERR		255	// Receive : An error number


// To request a hostlist from the Relay, send this packet :

struct IR_HLR // HostList Request
{
	byte	Size;		// 4
	byte	Type;		// IRP_HLR
	byte	ReqI;
	byte	Sp0;
};


// That will return (multiple) packets containing hostnames and some information about them

// The following struct is a subpacket of the IR_HOS packet

struct HInfo // Sub packet for IR_HOS. Contains host information
{
	char	HName[32];	// Name of the host
	
	char	Track[6];	// Short track name
	byte	Flags;		// Info flags about the host - see NOTE 1) below
	byte	NumConns;	// Number of people on the host
};

// NOTE 1)

#define HOS_SPECPASS		1	// Host requires a spectator password
#define HOS_LICENSED		2	// Bit is set if host is licensed
#define HOS_S1		        4	// Bit is set if host is S1
#define HOS_S2		        8	// Bit is set if host is S2
#define HOS_FIRST	        64	// Indicates the first host in the list
#define HOS_LAST	        128	// Indicates the last host in the list


struct IR_HOS // Hostlist (hosts connected to the Relay)
{
	byte	Size;		// 4 + NumHosts * 40
	byte	Type;		// IRP_HOS
	byte	ReqI;		// As given in IR_HLR
	byte	NumHosts;	// Number of hosts described in this packet

	HInfo	Info[6];	// Host info for every host in the Relay. 1 to 6 of these in a IR_HOS
};


// To select a host in the Relay, send this packet :

struct IR_SEL // Relay select - packet to select a host, so relay starts sending you data.
{
	byte	Size;		// 68
	byte	Type;		// IRP_SEL
	byte	ReqI;		// If non-zero Relay will reply with an IS_VER packet
	byte	Zero;		// 0

	char	HName[32];	// Hostname to receive data from - may be colourcode stripped
	char	Admin[16];	// Admin password (to gain admin access to host)
	char	Spec[16];	// Spectator password (if host requires it)

};


// To request if we are an admin send:

struct IR_ARQ // Admin Request
{
    byte    Size;		// 4
    byte    Type;		// IRP_ARQ
    byte    ReqI;
    byte    Sp0;
};


// Relay will reply to admin status request :

struct IR_ARP // Admin Response
 {
	 byte	Size;		// 4
	 byte	Type;		// IRP_ARP
	 byte	ReqI;
	 byte	Admin;		// 0- no admin; 1- admin
 };
 

// If you specify a wrong value, like invalid packet / hostname / adminpass / specpass, 
// the Relay returns an error packet :

struct IR_ERR
{
	byte	Size;		// 4
	byte	Type;		// IRP_ERR
	byte	ReqI;		// As given in RL_SEL, otherwise 0
	byte	ErrNo;		// Error number - see NOTE 2) below
};

// NOTE 2) Error numbers :

#define IR_ERR_PACKET       1   // Invalid packet sent by client (wrong structure / length)
#define IR_ERR_PACKET2 		2	// Invalid packet sent by client (packet was not allowed to be forwarded to host)
#define IR_ERR_HOSTNAME 	3	// Wrong hostname given by client
#define IR_ERR_ADMIN 		4	// Wrong admin pass given by client
#define IR_ERR_SPEC 		5	// Wrong spec pass given by client
#define IR_ERR_NOSPEC          6            // Spectator pass required, but none given

==============================================
Regular insim packets that a relay client can send to host :

For anyone
TINY_VER
TINY_PING
TINY_SCP
TINY_SST
TINY_GTH
TINY_ISM
TINY_NCN
TINY_NPL
TINY_RES
TINY_REO
TINY_RST
TINY_AXI

Admin only
TINY_VTC
ISP_MST
ISP_MSX
ISP_MSL
ISP_MTC
ISP_SCH
ISP_BFN
ISP_BTN

The relay will also accept, but not forward
TINY_NONE    // for relay-connection maintenance