minix/minix/drivers/tty/pty/tty.h

/*	tty.h - Terminals	*/

#include <minix/chardriver.h>
#include <minix/timers.h>

/* First minor numbers for the various classes of TTY devices. */
#define PTMX_MINOR	   0	/* minor of the Unix98 clone device */
#define TTYPX_MINOR	 128
#define PTYPX_MINOR	 192
#define UNIX98_MINOR	 256	/* start of Unix98 pairs */

#define TTY_IN_BYTES     256	/* tty input queue size */
#define TTY_OUT_BYTES   2048	/* tty output queue size */
#define TAB_SIZE           8	/* distance between tab stops */
#define TAB_MASK           7	/* mask to compute a tab stop position */

#define ESC             '\33'	/* escape */

struct tty;
typedef int (*devfun_t)(struct tty *tp, int try_only);
typedef void (*devfunarg_t)(struct tty *tp, int c);
typedef int (*devfunline_t)(struct tty *tp, devminor_t line);

typedef struct tty {
  int tty_events;		/* set when TTY should inspect this line */
  int tty_index;		/* index into TTY table */

  /* Input queue.  Typed characters are stored here until read by a program. */
  u16_t *tty_inhead;		/* pointer to place where next char goes */
  u16_t *tty_intail;		/* pointer to next char to be given to prog */
  int tty_incount;		/* # chars in the input queue */
  int tty_eotct;		/* number of "line breaks" in input queue */
  devfun_t tty_devread;		/* routine to read from low level buffers */
  devfun_t tty_icancel;		/* cancel any device input */
  int tty_min;			/* minimum requested #chars in input queue */
  minix_timer_t tty_tmr;		/* the timer for this tty */

  /* Output section. */
  devfun_t tty_devwrite;	/* routine to start actual device output */
  devfunarg_t tty_echo;		/* routine to echo characters input */
  devfun_t tty_ocancel;		/* cancel any ongoing device output */
  devfun_t tty_break_on;	/* let the device assert a break */
  devfun_t tty_break_off;	/* let the device de-assert a break */

  /* Terminal parameters and status. */
  int tty_position;		/* current position on the screen for echoing */
  char tty_reprint;		/* 1 when echoed input messed up, else 0 */
  char tty_escaped;		/* 1 when LNEXT (^V) just seen, else 0 */
  char tty_inhibited;		/* 1 when STOP (^S) just seen (stops output) */
  endpoint_t tty_pgrp;		/* endpoint of controlling process */
  char tty_openct;		/* count of number of opens of this tty */

  /* Information about incomplete I/O requests is stored here. */
  endpoint_t tty_incaller;	/* process that made the call, or NONE */
  cdev_id_t tty_inid;		/* ID of suspended read request */
  cp_grant_id_t tty_ingrant;	/* grant where data is to go */
  size_t tty_inleft;		/* how many chars are still needed */
  size_t tty_incum;		/* # chars input so far */
  endpoint_t tty_outcaller;	/* process that made the call, or NONE */
  cdev_id_t tty_outid;		/* ID of suspended write request */
  cp_grant_id_t tty_outgrant;	/* grant where data comes from */
  size_t tty_outleft;		/* # chars yet to be output */
  size_t tty_outcum;		/* # chars output so far */
  endpoint_t tty_iocaller;	/* process that made the call, or NONE */
  cdev_id_t tty_ioid;		/* ID of suspended ioctl request */
  unsigned int tty_ioreq;	/* ioctl request code */
  cp_grant_id_t tty_iogrant;	/* virtual address of ioctl buffer or grant */

  /* select() data */
  unsigned int tty_select_ops;	/* which operations are interesting */
  endpoint_t tty_select_proc;	/* which process wants notification */
  devminor_t tty_select_minor;	/* minor used to start select query */

  /* Miscellaneous. */
  devfunline_t tty_mayopen;	/* check whether this tty may be opened */
  devfun_t tty_open;		/* tell the device that the tty is opened */ 
  devfun_t tty_close;		/* tell the device that the tty is closed */
  void *tty_priv;		/* pointer to per device private data */
  struct termios tty_termios;	/* terminal attributes */
  struct winsize tty_winsize;	/* window size (#lines and #columns) */

  u16_t tty_inbuf[TTY_IN_BYTES];/* tty input buffer */

} tty_t;

/* Memory allocated in tty.c, so extern here. */
extern tty_t tty_table[NR_PTYS];
extern u32_t system_hz;		/* system clock frequency */
extern int tty_gid;		/* group ID of the "tty" group */

/* Values for the fields. */
#define NOT_ESCAPED        0	/* previous character is not LNEXT (^V) */
#define ESCAPED            1	/* previous character was LNEXT (^V) */
#define RUNNING            0	/* no STOP (^S) has been typed to stop output */
#define STOPPED            1	/* STOP (^S) has been typed to stop output */

/* Fields and flags on characters in the input queue. */
#define IN_CHAR       0x00FF	/* low 8 bits are the character itself */
#define IN_LEN        0x0F00	/* length of char if it has been echoed */
#define IN_LSHIFT          8	/* length = (c & IN_LEN) >> IN_LSHIFT */
#define IN_EOT        0x1000	/* char is a line break (^D, LF) */
#define IN_EOF        0x2000	/* char is EOF (^D), do not return to user */
#define IN_ESC        0x4000	/* escaped by LNEXT (^V), no interpretation */

/* Number of elements and limit of a buffer. */
#define buflen(buf)	(sizeof(buf) / sizeof((buf)[0]))
#define bufend(buf)	((buf) + buflen(buf))

/* Function prototypes for TTY driver. */
/* tty.c */
void handle_events(struct tty *tp);
void sigchar(struct tty *tp, int sig, int mayflush);
void tty_task(void);
tty_t *line2tty(devminor_t minor);
int in_process(struct tty *tp, char *buf, int count);
void out_process(struct tty *tp, char *bstart, char *bpos, char *bend,
	int *icount, int *ocount);
void tty_wakeup(clock_t now);
int select_try(struct tty *tp, int ops);
int select_retry(struct tty *tp);
int tty_ioctl(devminor_t minor, unsigned long request, endpoint_t endpt,
	cp_grant_id_t grant, int flags, endpoint_t user_endpt, cdev_id_t id);

/* pty.c */
void do_pty(message *m_ptr, int ipc_status);
void pty_init(struct tty *tp);
void select_retry_pty(struct tty *tp);