#define	NGROUPS		10	/* number of mpx files permitted at one time */#define	NCHANS		20	/* number of channel structures */#define	NPORTS		30	/* number of channels to i/o ports */#define	CNTLSIZ		10#define	NLEVELS		4#define	NMSIZE		50	/* max size of mxlstn file name *//* * header returned on read of mpx */struct	rh {	short	index;	short	count;	short	ccount;};/* * head expected on write of mpx */struct	wh {	short	index;	short	count;	short	ccount;	char	*data;};struct	mx_args {	char	*m_name;	int	m_cmd;	int	m_arg[3];};#ifdef KERNEL/* * internal structure for channel */struct chan {	short	c_flags;	char	c_index;	char	c_line;	struct	group	*c_group;	struct	file	*c_fy;	struct	tty	*c_ttyp;	struct	clist	c_ctlx;	int	c_pgrp;	struct	tty	*c_ottyp;	char	c_oline;	union {		struct	clist	datq;	} cx;	union {		struct	clist	datq;		struct	chan	*c_chan;	} cy;	struct	clist	c_ctly;};struct schan {	short	c_flags;	char	c_index;	char	c_line;	struct	group	*c_group;	struct	file	*c_fy;	struct	tty	*c_ttyp;	struct	clist	c_ctlx;	int	c_pgrp;};/* * flags */#define	INUSE	01#define COPEN	02#define	XGRP	04#define	YGRP	010#define	WCLOSE	020#define	ISGRP	0100#define	BLOCK	0200#define	EOTMARK	0400#define	SIGBLK	01000#define	BLKMSG	01000#define	ENAMSG	02000#define	WFLUSH	04000#define	NMBUF	010000#define	PORT	020000#define	ALT	040000#endif/* * mpxchan command codes */#define	MPX	5#define	MPXN	6#define	CHAN	1#define JOIN	2#define EXTR	3#define	ATTACH	4#define	CONNECT	7#define	DETACH	8#define	DISCON	9#define DEBUG	10#define	NPGRP	11#define	CSIG	12#define PACK	13#define NDEBUGS	30/* * control channel message codes */#define M_WATCH 1#define M_CLOSE 2#define	M_EOT	3#define	M_OPEN	4#define	M_BLK	5#define	M_UBLK	6#define	DO_BLK	7#define	DO_UBLK	8#define	M_IOCTL	12#define	M_SIG	14/* * debug codes other than mpxchan cmds */#define MCCLOSE 29#define MCOPEN	28#define	ALL	27#define SCON	26#define	MSREAD	25#define	SDATA	24#define	MCREAD	23#define MCWRITE	22