/*      $OpenBSD: tty.h,v 1.45 2025/09/25 08:46:50 mvs Exp $    */
/*      $NetBSD: tty.h,v 1.30.4.1 1996/06/02 09:08:13 mrg Exp $ */

/*-
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)tty.h       8.6 (Berkeley) 1/21/94
 */

#include <sys/termios.h>
#include <sys/queue.h>
#include <sys/selinfo.h>                /* For struct selinfo. */
#include <sys/timeout.h>

#define KERN_TTY_TKNIN          1       /* quad: input chars */
#define KERN_TTY_TKNOUT         2       /* quad: output chars */
#define KERN_TTY_TKRAWCC        3       /* quad: input chars, raw mode */
#define KERN_TTY_TKCANCC        4       /* quad: input char, cooked mode */
#define KERN_TTY_INFO           5       /* struct: tty stats */
/* was KERN_TTY_MAXPTYS         6 */
/* was KERN_TTY_NPTYS           7 */
#define KERN_TTY_MAXID          8

#define CTL_KERN_TTY_NAMES { \
        { 0, 0 }, \
        { "tk_nin", CTLTYPE_QUAD }, \
        { "tk_nout", CTLTYPE_QUAD }, \
        { "tk_rawcc", CTLTYPE_QUAD }, \
        { "tk_cancc", CTLTYPE_QUAD }, \
        { "ttyinfo", CTLTYPE_STRUCT }, \
        { "gap", 0 }, \
        { "gap", 0 }, \
}

/* ptmget, for /dev/ptm pty getting ioctl PTMGET */

struct ptmget {
        int     cfd;
        int     sfd;
        char    cn[16];
        char    sn[16];
};
#define PTMGET _IOR('t', 1, struct ptmget) /* get ptys */
#define PATH_PTMDEV     "/dev/ptm"
#define TTY_GID         4       /* XXX evil hardcoding of tty gid */

/*
 * Clists are actually ring buffers. The c_cc, c_cf, c_cl fields have
 * exactly the same behaviour as in true clists.
 * if c_cq is NULL, the ring buffer has no TTY_QUOTE functionality
 * (but, saves memory and cpu time)
 *
 * *DON'T* play with c_cs, c_ce, c_cq, or c_cl outside tty_subr.c!!!
 */
struct clist {
        int     c_cc;           /* count of characters in queue */
        int     c_cn;           /* total ring buffer length */
        u_char  *c_cf;          /* points to first character */
        u_char  *c_cl;          /* points to next open character */
        u_char  *c_cs;          /* start of ring buffer */
        u_char  *c_ce;          /* c_ce + c_len */
        u_char  *c_cq;          /* N bits/bytes long, see tty_subr.c */
};

/*
 * Per-tty structure.
 *
 * Should be split in two, into device and tty drivers.
 * Glue could be masks of what to echo and circular buffer
 * (low, high, timeout).
 */
struct tty {
        TAILQ_ENTRY(tty) tty_link;      /* Link in global tty list. */
        struct  clist t_rawq;           /* Device raw input queue. */
        long    t_rawcc;                /* Raw input queue statistics. */
        struct  clist t_canq;           /* Device canonical queue. */
        long    t_cancc;                /* Canonical queue statistics. */
        struct  clist t_outq;           /* Device output queue. */
        long    t_outcc;                /* Output queue statistics. */
        int     t_qlen;                 /* Length of above queues */
        u_char  t_line;                 /* Interface to device drivers. */
        dev_t   t_dev;                  /* Device. */
        int     t_state;                /* Device and driver (TS*) state. */
        int     t_flags;                /* Tty flags. */
        struct  pgrp *t_pgrp;           /* Foreground process group. */
        struct  session *t_session;     /* Enclosing session. */
        struct  selinfo t_rsel;         /* Tty read/oob select. */
        struct  selinfo t_wsel;         /* Tty write select. */
        struct  termios t_termios;      /* Termios state. */
        struct  winsize t_winsize;      /* Window size. */
                                        /* Start output. */
        void    (*t_oproc)(struct tty *);
                                        /* Set hardware state. */
        int     (*t_param)(struct tty *, struct termios *);
                                        /* Set hardware flow control. */
        int     (*t_hwiflow)(struct tty *tp, int flag);
        void    *t_sc;                  /* XXX: net/if_sl.c:sl_softc. */
        short   t_column;               /* Tty output column. */
        short   t_rocount, t_rocol;     /* Tty. */
        short   t_hiwat;                /* High water mark. */
        short   t_lowat;                /* Low water mark. */
        short   t_gen;                  /* Generation number. */
        struct timeout t_rstrt_to;      /* restart timeout */
        struct timeval t_tv;            /* timestamp */
};

/*
 * Small version of struct tty exported via sysctl KERN_TTY_INFO
 */
struct itty {
        dev_t   t_dev;
        int t_rawq_c_cc;
        int t_canq_c_cc;
        int t_outq_c_cc;
        short t_hiwat;
        short t_lowat;
        short t_column;
        int t_state;
        struct session *t_session;
        pid_t t_pgrp_pg_id;
        u_char t_line;
};

#define t_cc            t_termios.c_cc
#define t_cflag         t_termios.c_cflag
#define t_iflag         t_termios.c_iflag
#define t_ispeed        t_termios.c_ispeed
#define t_lflag         t_termios.c_lflag
#define t_min           t_termios.c_min
#define t_oflag         t_termios.c_oflag
#define t_ospeed        t_termios.c_ospeed
#define t_time          t_termios.c_time

#define TTIPRI  25                      /* Sleep priority for tty reads. */
#define TTOPRI  26                      /* Sleep priority for tty writes. */

#define OBUFSIZ 512
#define TTYHOG(tp)      (tp)->t_qlen

#ifdef _KERNEL
#define TTMAXLOWAT      256
#define TTMINLOWAT      32
#define TTMINHIWAT      100
#define TTHIWATMINSPACE 200             /* Min space above hiwat */
#endif

/* These flags are kept in t_state. */
#define TS_ASLEEP       0x00001         /* Process waiting for tty. */
#define TS_ASYNC        0x00002         /* Tty in async I/O mode. */
#define TS_BUSY         0x00004         /* Draining output. */
#define TS_CARR_ON      0x00008         /* Carrier is present. */
#define TS_FLUSH        0x00010         /* Outq has been flushed during DMA. */
#define TS_ISOPEN       0x00020         /* Open has completed. */
#define TS_TBLOCK       0x00040         /* Further input blocked. */
#define TS_TIMEOUT      0x00080         /* Wait for output char processing. */
#define TS_TTSTOP       0x00100         /* Output paused. */
#define TS_WOPEN        0x00200         /* Open in progress. */
#define TS_XCLUDE       0x00400         /* Tty requires exclusivity. */

/* State for intra-line fancy editing work. */
#define TS_BKSL         0x00800         /* State for lowercase \ work. */
#define TS_CNTTB        0x01000         /* Counting tab width, ignore FLUSHO. */
#define TS_ERASE        0x02000         /* Within a \.../ for PRTRUB. */
#define TS_LNCH         0x04000         /* Next character is literal. */
#define TS_TYPEN        0x08000         /* Retyping suspended input (PENDIN). */
#define TS_LOCAL        (TS_BKSL | TS_CNTTB | TS_ERASE | TS_LNCH | TS_TYPEN)

#define TS_TSTAMPDCDSET 0x10000         /* update timestamp on DCD set */
#define TS_TSTAMPDCDCLR 0x20000         /* update timestamp on DCD clr */
#define TS_TSTAMPCTSSET 0x40000         /* update timestamp on CTS set */
#define TS_TSTAMPCTSCLR 0x80000         /* update timestamp on CTS clr */

/* Character type information. */
#define ORDINARY        0
#define CONTROL         1
#define BACKSPACE       2
#define NEWLINE         3
#define TAB             4
#define VTAB            5
#define RETURN          6

struct speedtab {
        int sp_speed;                   /* Speed. */
        int sp_code;                    /* Code. */
};

/* Modem control commands (driver). */
#define DMSET           0
#define DMBIS           1
#define DMBIC           2
#define DMGET           3

/* Flags on a character passed to ttyinput. */
#define TTY_CHARMASK    0x000000ff      /* Character mask */
#define TTY_QUOTE       0x00000100      /* Character quoted */
#define TTY_ERRORMASK   0xff000000      /* Error mask */
#define TTY_FE          0x01000000      /* Framing error or BREAK condition */
#define TTY_PE          0x02000000      /* Parity error */

/* Is tp controlling terminal for pr? */
#define isctty(pr, tp)                                                  \
        ((pr)->ps_session == (tp)->t_session && (pr)->ps_flags & PS_CONTROLT)

/* Is pr in background of tp? */
#define isbackground(pr, tp)                                            \
        (isctty((pr), (tp)) && (pr)->ps_pgrp != (tp)->t_pgrp)

/*
 * ttylist_head is defined here so that user-land has access to it.
 */
TAILQ_HEAD(ttylist_head, tty);          /* the ttylist is a TAILQ */

#ifdef _KERNEL

extern  int tty_count;                  /* number of ttys in global ttylist */

/* Symbolic sleep message strings. */
extern   char ttyin[], ttyout[], ttopen[], ttclos[], ttybg[];

extern int64_t tk_cancc, tk_nin, tk_nout, tk_rawcc;

int     sysctl_tty(int *, u_int, void *, size_t *, void *, size_t);
int     sysctl_pty(int *, u_int, void *, size_t *, void *, size_t);

int      b_to_q(u_char *cp, int cc, struct clist *q);
void     catq(struct clist *from, struct clist *to);
int      getc(struct clist *q);
void     ndflush(struct clist *q, int cc);
int      ndqb(struct clist *q, int flag);
u_char  *firstc(struct clist *clp, int *c, int *cc);
u_char  *nextc(struct clist *q, u_char *cp, int *c, int *cc);
int      putc(int c, struct clist *q);
int      q_to_b(struct clist *q, u_char *cp, int cc);
int      unputc(struct clist *q);

int      nullmodem(struct tty *tp, int flag);
int      tputchar(int c, struct tty *tp);
int      ttioctl(struct tty *tp, u_long com, caddr_t data, int flag,
            struct proc *p);
int      ttread(struct tty *tp, struct uio *uio, int flag);
void     ttrstrt(void *tp);
int      ttkqfilter(dev_t dev, struct knote *kn);
void     ttsetwater(struct tty *tp);
int      ttspeedtab(int speed, const struct speedtab *table);
int      ttstart(struct tty *tp);
void     ttwakeupwr(struct tty *tp);
void     ttwakeup(struct tty *tp);
int      ttwrite(struct tty *tp, struct uio *uio, int flag);
void     ttychars(struct tty *tp);
int      ttycheckoutq(struct tty *tp, int wait);
int      ttyclose(struct tty *tp);
void     ttyflush(struct tty *tp, int rw);
void     ttyinfo(struct tty *tp);
int      ttyinput(int c, struct tty *tp);
int      ttylclose(struct tty *tp, int flag, struct proc *p);
int      ttymodem(struct tty *tp, int flag);
int      ttyopen(dev_t device, struct tty *tp, struct proc *p);
int      ttyoutput(int c, struct tty *tp);
void     ttypend(struct tty *tp);
int      ttyretype(struct tty *tp);
int      ttyrub(int c, struct tty *tp);
int      ttysleep(struct tty *tp, void *chan, int pri, char *wmesg);
int      ttysleep_nsec(struct tty *, void *, int, char *, uint64_t);
int      ttywait(struct tty *tp);
int      ttywflush(struct tty *tp);
void     ttytstamp(struct tty *tp, int octs, int ncts, int odcd, int ndcd);

void    tty_init(void);
struct tty *ttymalloc(int);
void     ttyfree(struct tty *);

int     cttyopen(dev_t, int, int, struct proc *);
int     cttyread(dev_t, struct uio *, int);
int     cttywrite(dev_t, struct uio *, int);
int     cttyioctl(dev_t, u_long, caddr_t, int, struct proc *);

void    clalloc(struct clist *, int, int);
void    clfree(struct clist *);

int     nullioctl(struct tty *, u_long, caddr_t, int, struct proc *);

int     pppopen(dev_t dev, struct tty *, struct proc *);
int     pppclose(struct tty *, int, struct proc *);
int     ppptioctl(struct tty *, u_long, caddr_t, int, struct proc *);
int     pppinput(int c, struct tty *);
int     pppstart(struct tty *);
int     pppread(struct tty *, struct uio *, int);
int     pppwrite(struct tty *, struct uio *, int);

int     nmeaopen(dev_t, struct tty *, struct proc *);
int     nmeaclose(struct tty *, int, struct proc *);
int     nmeainput(int, struct tty *);

int     mstsopen(dev_t, struct tty *, struct proc *);
int     mstsclose(struct tty *, int, struct proc *);
int     mstsinput(int, struct tty *);

int     endrunopen(dev_t, struct tty *, struct proc *);
int     endrunclose(struct tty *, int, struct proc *);
int     endruninput(int, struct tty *);

#endif /* _KERNEL */