Adjusted formatting/conventions to conform to rest of ZT codebase

netcon/NetconEthernetTap.hpp

@@ -46,6 +46,8 @@
 
 #include "netif/etharp.h"
 
+#include "RPC.h"
+
 struct tcp_pcb;
 struct socket_st;
 struct listen_st;
@@ -102,44 +104,312 @@ public:
 
 private:
 	// LWIP callbacks
-	static err_t nc_poll(void* arg, struct tcp_pcb *tpcb);
-	static err_t nc_accept(void *arg, struct tcp_pcb *newpcb, err_t err);
-	static err_t nc_recved(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err);
+	// NOTE: these are called from within LWIP, meaning that lwipstack->_lock is ALREADY
+	// locked in this case!
+
+	/*
+	 * Callback from LWIP for when a connection has been accepted and the PCB has been
+	 * put into an ACCEPT state.
+	 *
+	 * A socketpair is created, one end is kept and wrapped into a PhySocket object
+	 * for use in the main ZT I/O loop, and one end is sent to the client. The client
+	 * is then required to tell the service what new file descriptor it has allocated
+	 * for this connection. After the mapping is complete, the accepted socket can be
+	 * used.
+	 *
+	 * @param associated service state object
+	 * @param newly allocated PCB
+	 * @param error code
+	 * @return ERR_OK if everything is ok, -1 otherwise
+	 *
+	 *	 i := should be implemented in intercept lib
+	 *	 I := is implemented in intercept lib
+	 *	 X := is implemented in service
+	 *	 ? := required treatment Unknown
+	 *	 - := Not needed
+	 *
+	 *	[ ] EAGAIN or EWOULDBLOCK - The socket is marked nonblocking and no connections are present
+	 *													to be accepted. POSIX.1-2001 allows either error to be returned for
+	 *													this case, and does not require these constants to have the same value,
+	 *													so a portable application should check for both possibilities.
+	 *	[I] EBADF - The descriptor is invalid.
+	 *	[I] ECONNABORTED - A connection has been aborted.
+	 *	[i] EFAULT - The addr argument is not in a writable part of the user address space.
+	 *	[-] EINTR - The system call was interrupted by a signal that was caught before a valid connection arrived; see signal(7).
+	 *	[I] EINVAL - Socket is not listening for connections, or addrlen is invalid (e.g., is negative).
+	 *	[I] EINVAL - (accept4()) invalid value in flags.
+	 *	[I] EMFILE - The per-process limit of open file descriptors has been reached.
+	 *	[ ] ENFILE - The system limit on the total number of open files has been reached.
+	 *	[ ] ENOBUFS, ENOMEM - Not enough free memory. This often means that the memory allocation is
+	 *												limited by the socket buffer limits, not by the system memory.
+	 *	[I] ENOTSOCK - The descriptor references a file, not a socket.
+	 *	[I] EOPNOTSUPP - The referenced socket is not of type SOCK_STREAM.
+	 *	[ ] EPROTO - Protocol error.
+	 *
+	 */
+	static err_t nc_accept(void *arg, struct tcp_pcb *newPCB, err_t err);
+
+	/*
+	 * Callback from LWIP for when data is available to be read from the network.
+	 *
+	 * Data is in the form of a linked list of struct pbufs, it is then recombined and
+	 * send to the client over the associated unix socket.
+	 *
+	 * @param associated service state object
+	 * @param allocated PCB
+	 * @param chain of pbufs
+	 * @param error code
+	 * @return ERR_OK if everything is ok, -1 otherwise
+	 *
+	 */
+ 	static err_t nc_recved(void *arg, struct tcp_pcb *PCB, struct pbuf *p, err_t err);
+
+	/*
+	 * Callback from LWIP when an internal error is associtated with the given (arg)
+	 *
+	 * Since the PCB related to this error might no longer exist, only its perviously
+	 * associated (arg) is provided to us.
+	 *
+	 * @param associated service state object
+	 * @param error code
+	 *
+	 */
 	static void nc_err(void *arg, err_t err);
-	static void nc_close(struct tcp_pcb *tpcb);
-	static err_t nc_send(struct tcp_pcb *tpcb);
-	static err_t nc_sent(void *arg, struct tcp_pcb *tpcb, u16_t len);
-	static err_t nc_connected(void *arg, struct tcp_pcb *tpcb, err_t err);
-
-	// RPC handlers (from NetconIntercept)
-	void unload_rpc(void *data, pid_t &pid, pid_t &tid, 
-		int &rpc_count, char (timestamp[20]), char (magic[sizeof(uint64_t)]), char &cmd, void* &payload);
-
-	void handle_getsockname(PhySocket *sock, PhySocket *rpcsock, void **uptr, struct getsockname_st *getsockname_rpc);
-	void handle_bind(PhySocket *sock, PhySocket *rpcsock, void **uptr, struct bind_st *bind_rpc);
-	void handle_listen(PhySocket *sock, PhySocket *rpcsock, void **uptr, struct listen_st *listen_rpc);
-	TcpConnection * handle_socket(PhySocket *sock, void **uptr, struct socket_st* socket_rpc);
-	void handle_connect(PhySocket *sock, PhySocket *rpcsock, TcpConnection *conn, struct connect_st* connect_rpc);
-	void handle_write(TcpConnection *conn);
-
-	int send_return_value(PhySocket *sock, int retval, int _errno);
-	int send_return_value(int fd, int retval, int _errno);
 
+	/*
+	 * Callback from LWIP to do whatever work we might need to do.
+	 *
+	 * @param associated service state object
+	 * @param PCB we're polling on
+	 * @return ERR_OK if everything is ok, -1 otherwise
+	 *
+	 */
+	static err_t nc_poll(void* arg, struct tcp_pcb *PCB);
+
+	/*
+	 * Callback from LWIP to signal that 'len' bytes have successfully been sent.
+	 * As a result, we should put our socket back into a notify-on-readability state
+	 * since there is now room on the PCB buffer to write to.
+	 *
+	 * NOTE: This could be used to track the amount of data sent by a connection.
+	 *
+	 * @param associated service state object
+	 * @param relevant PCB
+	 * @param length of data sent
+	 * @return ERR_OK if everything is ok, -1 otherwise
+	 *
+	 */
+	static err_t nc_sent(void *arg, struct tcp_pcb *PCB, u16_t len);
+
+	/*
+	 * Callback from LWIP which sends a return value to the client to signal that
+	 * a connection was established for this PCB
+	 *
+	 * @param associated service state object
+	 * @param relevant PCB
+	 * @param error code
+	 * @return ERR_OK if everything is ok, -1 otherwise
+	 *
+	 */
+	static err_t nc_connected(void *arg, struct tcp_pcb *PCB, err_t err);
+	
+	//static void nc_close(struct tcp_pcb *PCB);
+	//static err_t nc_send(struct tcp_pcb *PCB);
+
+	/*
+	 * Handles an RPC to bind an LWIP PCB to a given address and port
+	 *
+	 * @param PhySocket associated with this RPC connection
+	 * @param structure containing the data and parameters for this client's RPC
+	 *
+
+	 i := should be implemented in intercept lib
+	 I := is implemented in intercept lib
+	 X := is implemented in service
+	 ? := required treatment Unknown
+	 - := Not needed
+
+	[ ]	EACCES - The address is protected, and the user is not the superuser.
+	[X]	EADDRINUSE - The given address is already in use.
+	[I]	EBADF - sockfd is not a valid descriptor.
+	[X]	EINVAL - The socket is already bound to an address.
+	[I]	ENOTSOCK - sockfd is a descriptor for a file, not a socket.
+
+	[X]	ENOMEM - Insufficient kernel memory was available.
+
+	  - The following errors are specific to UNIX domain (AF_UNIX) sockets:
+
+	[-]	EACCES - Search permission is denied on a component of the path prefix. (See also path_resolution(7).)
+	[-]	EADDRNOTAVAIL - A nonexistent interface was requested or the requested address was not local.
+	[-]	EFAULT - addr points outside the user's accessible address space.
+	[-]	EINVAL - The addrlen is wrong, or the socket was not in the AF_UNIX family.
+	[-]	ELOOP - Too many symbolic links were encountered in resolving addr.
+	[-]	ENAMETOOLONG - s addr is too long.
+	[-]	ENOENT - The file does not exist.
+	[-]	ENOTDIR - A component of the path prefix is not a directory.
+	[-]	EROFS - The socket inode would reside on a read-only file system.
+	 */
+	void handleBind(PhySocket *sock, PhySocket *rpcsock, void **uptr, struct bind_st *bind_rpc);
+	
+	/*
+	 * Handles an RPC to put an LWIP PCB into LISTEN mode
+	 *
+	 * @param PhySocket associated with this RPC connection
+	 * @param structure containing the data and parameters for this client's RPC
+	 *
+
+	 i := should be implemented in intercept lib
+	 I := is implemented in intercept lib
+	 X := is implemented in service
+	 ? := required treatment Unknown
+	 - := Not needed
+
+	[?] EADDRINUSE - Another socket is already listening on the same port.
+	[IX] EBADF - The argument sockfd is not a valid descriptor.
+	[I] ENOTSOCK - The argument sockfd is not a socket.
+	[I] EOPNOTSUPP - The socket is not of a type that supports the listen() operation.
+	 */
+	void handleListen(PhySocket *sock, PhySocket *rpcsock, void **uptr, struct listen_st *listen_rpc);
+	
+	/*
+	 * Handles an RPC to create a socket (LWIP PCB and associated socketpair)
+	 *
+	 * A socketpair is created, one end is kept and wrapped into a PhySocket object
+	 * for use in the main ZT I/O loop, and one end is sent to the client. The client
+	 * is then required to tell the service what new file descriptor it has allocated
+	 * for this connection. After the mapping is complete, the socket can be used.
+	 *
+	 * @param PhySocket associated with this RPC connection
+	 * @param structure containing the data and parameters for this client's RPC
+	 *
+
+	 i := should be implemented in intercept lib
+	 I := is implemented in intercept lib
+	 X := is implemented in service
+	 ? := required treatment Unknown
+	 - := Not needed
+
+	[-] EACCES - Permission to create a socket of the specified type and/or protocol is denied.
+	[I] EAFNOSUPPORT - The implementation does not support the specified address family.
+	[I] EINVAL - Unknown protocol, or protocol family not available.
+	[I] EINVAL - Invalid flags in type.
+	[I] EMFILE - Process file table overflow.
+	[?] ENFILE - The system limit on the total number of open files has been reached.
+	[X] ENOBUFS or ENOMEM - Insufficient memory is available.  The socket cannot be created until sufficient resources are freed.
+	[?] EPROTONOSUPPORT - The protocol type or the specified protocol is not supported within this domain.
+	 */
+	TcpConnection * handleSocket(PhySocket *sock, void **uptr, struct socket_st* socket_rpc);
+	
+	/*
+	 * Handles an RPC to connect to a given address and port
+	 *
+	 * @param PhySocket associated with this RPC connection
+	 * @param structure containing the data and parameters for this client's RPC
+
+	--- Error handling in this method will only catch problems which are immedately
+	    apprent. Some errors will need to be caught in the nc_connected(0 callback
+
+	 i := should be implemented in intercept lib
+ 	 I := is implemented in intercept lib
+ 	 X := is implemented in service
+ 	 ? := required treatment Unknown
+ 	 - := Not needed
+
+	[-] EACCES - For UNIX domain sockets, which are identified by pathname: Write permission is denied ...
+	[?] EACCES, EPERM - The user tried to connect to a broadcast address without having the socket broadcast flag enabled ...
+	[X] EADDRINUSE - Local address is already in use.
+	[I] EAFNOSUPPORT - The passed address didn't have the correct address family in its sa_family field.
+	[X] EAGAIN - No more free local ports or insufficient entries in the routing cache.
+	[ ] EALREADY - The socket is nonblocking and a previous connection attempt has not yet been completed.
+	[IX] EBADF - The file descriptor is not a valid index in the descriptor table.
+	[ ] ECONNREFUSED - No-one listening on the remote address.
+	[i] EFAULT - The socket structure address is outside the user's address space.
+	[ ] EINPROGRESS - The socket is nonblocking and the connection cannot be completed immediately.
+	[-] EINTR - The system call was interrupted by a signal that was caught.
+	[X] EISCONN - The socket is already connected.
+	[X] ENETUNREACH - Network is unreachable.
+	[I] ENOTSOCK - The file descriptor is not associated with a socket.
+	[X] ETIMEDOUT - Timeout while attempting connection.
+
+	[X] EINVAL - Invalid argument, SVr4, generally makes sense to set this
+	 */
+	void handleConnect(PhySocket *sock, PhySocket *rpcsock, TcpConnection *conn, struct connect_st* connect_rpc);
+	
+	/* 
+	 * Return the address that the socket is bound to 
+	 */
+	void handleGetsockname(PhySocket *sock, PhySocket *rpcsock, void **uptr, struct getsockname_st *getsockname_rpc);
+
+	/* 
+ 	 * Writes data from the application's socket to the LWIP connection
+ 	 */
+	void handleWrite(TcpConnection *conn);
+
+	/*
+	 * Sends a return value to the intercepted application
+	 */
+	int sendReturnValue(PhySocket *sock, int retval, int _errno);
+	int sendReturnValue(int fd, int retval, int _errno);
+
+	/* 
+ 	* Unpacks the buffer from an RPC command
+ 	*/
+	void unloadRPC(void *data, pid_t &pid, pid_t &tid, 
+		int &rpc_count, char (timestamp[RPC_TIMESTAMP_SZ]), char (magic[sizeof(uint64_t)]), char &cmd, void* &payload);
+
+	// Unused -- no UDP or TCP from this thread/Phy<>
 	void phyOnDatagram(PhySocket *sock,void **uptr,const struct sockaddr *from,void *data,unsigned long len);
 	void phyOnTcpConnect(PhySocket *sock,void **uptr,bool success);
 	void phyOnTcpAccept(PhySocket *sockL,PhySocket *sockN,void **uptrL,void **uptrN,const struct sockaddr *from);
 	void phyOnTcpClose(PhySocket *sock,void **uptr);
 	void phyOnTcpData(PhySocket *sock,void **uptr,void *data,unsigned long len);
 	void phyOnTcpWritable(PhySocket *sock,void **uptr);
+
+	/*
+ 	 * Add a new PhySocket for the client connections
+ 	 */
 	void phyOnUnixAccept(PhySocket *sockL,PhySocket *sockN,void **uptrL,void **uptrN);
+
+	/*
+ 	 * Signals us to close the TcpConnection associated with this PhySocket
+ 	 */
 	void phyOnUnixClose(PhySocket *sock,void **uptr);
+	
+    /* 
+ 	 * Notifies us that there is data to be read from an application's socket
+ 	 */
 	void phyOnUnixData(PhySocket *sock,void **uptr,void *data,unsigned long len);
+	
+	/* 
+ 	 * Notifies us that we can write to an application's socket
+ 	 */
 	void phyOnUnixWritable(PhySocket *sock,void **uptr);
+	
+	/*
+ 	 * Handles data on a application's data buffer. Data is sent to LWIP to be enqueued.
+ 	 * TODO: This is a candidate for removal now that phyOnUnixData() is used for everything
+ 	 */
 	void phyOnFileDescriptorActivity(PhySocket *sock,void **uptr,bool readable,bool writable);
 
+	/*
+ 	 * Returns a pointer to a TcpConnection associated with a given PhySocket
+ 	 */
 	TcpConnection *getConnection(PhySocket *sock);
-	void addConnection(TcpConnection *conn);
+	
+	/*
+ 	 * Safely adds a new TcpConnection to _TcpConnections
+ 	 */
+	TcpConnection *addConnection(TcpConnection *conn);
+	
+	/*
+ 	 * Safely removes a TcpConnection from _TcpConnections
+ 	 */
 	void removeConnection(TcpConnection *conn);
+
+	/*
+ 	 * Closes a TcpConnection, associated LWIP PCB strcuture, 
+ 	 * PhySocket, and underlying file descriptor
+ 	 */
 	void closeConnection(PhySocket *sock);
 
 	ip_addr_t convert_ip(struct sockaddr_in * addr)
@@ -157,12 +427,10 @@ private:
 	Phy<NetconEthernetTap *> _phy;
 	PhySocket *_unixListenSocket;
 
-	std::vector<TcpConnection*> tcp_connections;
-	std::map<PhySocket*, pid_t> pidmap;
-
+	std::vector<TcpConnection*> _TcpConnections;
 	std::map<uint64_t, std::pair<PhySocket*, void*> > jobmap;
 
-	pid_t rpc_counter;
+	pid_t rpcCounter;
 	netif interface;
 
 	MAC _mac;
@@ -174,7 +442,7 @@ private:
 	Mutex _multicastGroups_m;
 
 	std::vector<InetAddress> _ips;
-	Mutex _ips_m, _tcpconns_m, _rx_buf_m, _tx_buf_m;
+	Mutex _ips_m, _tcpconns_m, _rx_buf_m;
 
 	unsigned int _mtu;
 	volatile bool _enabled;

netcon/RPC.c

@@ -113,22 +113,22 @@ int rpc_join(const char * sockname)
 int rpc_send_command(char *path, int cmd, int forfd, void *data, int len)
 {
   pthread_mutex_lock(&lock);
-  char c, padding[] = {0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89};
-  char cmdbuf[BUF_SZ], CANARY[TOKEN_SIZE], metabuf[BUF_SZ];
-  memcpy(CANARY+CANARY_SIZE, padding, sizeof(padding));
+  char c, padding[] = {PADDING};
+  char cmdbuf[BUF_SZ], CANARY[CANARY_SZ+PADDING_SZ], metabuf[BUF_SZ];
+  memcpy(CANARY+CANARY_SZ, padding, sizeof(padding));
   uint64_t canary_num;
   // ephemeral RPC socket used only for this command
   int rpc_sock = rpc_join(path);
   // Generate token
   int fdrand = open("/dev/urandom", O_RDONLY);
 
-  if(read(fdrand, &CANARY, CANARY_SIZE) < 0) {
+  if(read(fdrand, &CANARY, CANARY_SZ) < 0) {
      fprintf(stderr,"unable to read from /dev/urandom for RPC canary data\n");
      return -1;  
   }
-  memcpy(&canary_num, CANARY, CANARY_SIZE);  
+  memcpy(&canary_num, CANARY, CANARY_SZ);  
   cmdbuf[CMD_ID_IDX] = cmd;
-  memcpy(&cmdbuf[CANARY_IDX], &canary_num, CANARY_SIZE);
+  memcpy(&cmdbuf[CANARY_IDX], &canary_num, CANARY_SZ);
   memcpy(&cmdbuf[STRUCT_IDX], data, len);
 
 #ifdef VERBOSE
@@ -140,7 +140,7 @@ int rpc_send_command(char *path, int cmd, int forfd, void *data, int len)
   time_t timestamp;
   timestamp = time(NULL);
   strftime(timestring, sizeof(timestring), "%H:%M:%S", localtime(&timestamp));
-  memcpy(metabuf, RPC_PHRASE, RPC_PHRASE_SIZE); // Write signal phrase
+  memcpy(metabuf, RPC_PHRASE, RPC_PHRASE_SZ); // Write signal phrase
   
   memcpy(&metabuf[IDX_PID],     &pid,         sizeof(pid_t)      ); /* pid       */
   memcpy(&metabuf[IDX_TID],     &tid,         sizeof(pid_t)      ); /* tid       */
@@ -148,7 +148,7 @@ int rpc_send_command(char *path, int cmd, int forfd, void *data, int len)
   memcpy(&metabuf[IDX_TIME],    &timestring,   20                ); /* timestamp */
 #endif
   /* Combine command flag+payload with RPC metadata */
-  memcpy(&metabuf[IDX_PAYLOAD], cmdbuf, len + 1 + CANARY_SIZE);
+  memcpy(&metabuf[IDX_PAYLOAD], cmdbuf, len + 1 + CANARY_SZ);
   
   // Write RPC
   int n_write = write(rpc_sock, &metabuf, BUF_SZ);
@@ -162,7 +162,7 @@ int rpc_send_command(char *path, int cmd, int forfd, void *data, int len)
     return -1;
   }
   if(c == 'z' && n_write > 0 && forfd > -1){
-    if(send(forfd, &CANARY, TOKEN_SIZE, 0) < 0) {
+    if(send(forfd, &CANARY, CANARY_SZ+PADDING_SZ, 0) < 0) {
       fprintf(stderr,"unable to write canary to stream\n");
       return -1;
     }

netcon/RPC.h

@@ -3,48 +3,43 @@
 
 #include <stdint.h>
 
-#define CANARY_SIZE			sizeof(uint64_t)
-#define CANARY_PADDING_SIZE	12
-#define TOKEN_SIZE			CANARY_SIZE+CANARY_PADDING_SIZE
+#define CANARY_SZ				sizeof(uint64_t)
+#define PADDING_SZ				12
+#define PADDING 				0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89
 
-#define RPC_PHRASE 			"zerotier\0"
-#define RPC_PHRASE_SIZE		9
+#define RPC_PHRASE 				"zerotier\0"
+#define RPC_PHRASE_SZ			9
+#define RPC_TIMESTAMP_SZ		20
 // 1st RPC section (metdata)
-#define IDX_SIGNAL_PHRASE	0
-#define IDX_PID				IDX_SIGNAL_PHRASE + RPC_PHRASE_SIZE
-#define IDX_TID				sizeof(pid_t) + IDX_PID
-#define IDX_COUNT			IDX_TID + sizeof(pid_t)
-#define IDX_TIME			IDX_COUNT + sizeof(int)
-#define IDX_PAYLOAD			IDX_TIME + 20 /* 20 being the length of the timestamp string */
+#define IDX_SIGNAL_PHRASE		0
+#define IDX_PID					IDX_SIGNAL_PHRASE + RPC_PHRASE_SZ
+#define IDX_TID					sizeof(pid_t) + IDX_PID
+#define IDX_COUNT				IDX_TID + sizeof(pid_t)
+#define IDX_TIME				IDX_COUNT + sizeof(int)
+#define IDX_PAYLOAD				IDX_TIME + RPC_TIMESTAMP_SZ
 // 2nd RPC section (payload and canary)
-#define CMD_ID_IDX			0
-#define CANARY_IDX			1
-#define STRUCT_IDX			CANARY_IDX+CANARY_SIZE
+#define CMD_ID_IDX				0
+#define CANARY_IDX				1
+#define STRUCT_IDX				CANARY_IDX+CANARY_SZ
 
-#define BUF_SZ          	512
+#define BUF_SZ          		512
 
-#define ERR_OK          	0
+#define ERR_OK          		0
 
 /* RPC codes */
-#define RPC_UNDEFINED			 	0
-#define RPC_CONNECT				 	1
-#define RPC_CONNECT_SOCKARG		 	2
-#define RPC_CLOSE				 	3
-#define RPC_READ				 	4
-#define RPC_WRITE				 	5
-#define RPC_BIND				 	6
-#define RPC_ACCEPT			 		7
-#define RPC_LISTEN			 		8
-#define RPC_SOCKET			 		9
-#define RPC_SHUTDOWN		 		10
-#define RPC_GETSOCKNAME				11
-
-/* Administration RPC codes */
-#define RPC_MAP						20	/* Give the service the value we "see" for the new buffer fd */
-#define RPC_MAP_REQ					21  /* A call to determine whether an fd is mapped to the service */
-#define RPC_RETVAL					22	/* not RPC per se, but something we should codify */
-#define RPC_KILL_INTERCEPT			23  /* Tells the service we need to shut down all connections */
-
+#define RPC_UNDEFINED			0
+#define RPC_CONNECT				1
+#define RPC_CONNECT_SOCKARG		2
+#define RPC_CLOSE				3
+#define RPC_READ				4
+#define RPC_WRITE				5
+#define RPC_BIND				6
+#define RPC_ACCEPT			 	7
+#define RPC_LISTEN			 	8
+#define RPC_SOCKET			 	9
+#define RPC_SHUTDOWN		 	10
+#define RPC_GETSOCKNAME			11
+#define RPC_RETVAL				22
 
 #ifdef __cplusplus
 extern "C" {

netcon/common.inc.c

@@ -44,11 +44,11 @@
 
 #define DEBUG_LEVEL     0
 
-#define MSG_WARNING     4
-#define MSG_ERROR       1 // Errors
-#define MSG_INFO        2 // Information which is generally useful to any user
-#define MSG_DEBUG       3 // Information which is only useful to someone debugging
-#define MSG_DEBUG_EXTRA 4 // If nothing in your world makes sense
+#define MSG_TRANSFER    1 // RX/TX specific statements
+#define MSG_ERROR       2 // Errors
+#define MSG_INFO        3 // Information which is generally useful to any user
+#define MSG_DEBUG       4 // Information which is only useful to someone debugging
+#define MSG_DEBUG_EXTRA 5 // If nothing in your world makes sense
 
 #ifdef NETCON_INTERCEPT