/*- * Copyright (c) 1982, 1986, 1990, 1991, 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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.c 8.8 (Berkeley) 1/21/94 * $FreeBSD$ */ /*- * TODO: * o Fix races for sending the start char in ttyflush(). * o Handle inter-byte timeout for "MIN > 0, TIME > 0" in ttyselect(). * With luck, there will be MIN chars before select() returns(). * o Handle CLOCAL consistently for ptys. Perhaps disallow setting it. * o Don't allow input in TS_ZOMBIE case. It would be visible through * FIONREAD. * o Do the new sio locking stuff here and use it to avoid special * case for EXTPROC? * o Lock PENDIN too? * o Move EXTPROC and/or PENDIN to t_state? * o Wrap most of ttioctl in spltty/splx. * o Implement TIOCNOTTY or remove it from . * o Send STOP if IXOFF is toggled off while TS_TBLOCK is set. * o Don't allow certain termios flags to affect disciplines other * than TTYDISC. Cancel their effects before switch disciplines * and ignore them if they are set while we are in another * discipline. * o Now that historical speed conversions are handled here, don't * do them in drivers. * o Check for TS_CARR_ON being set while everything is closed and not * waiting for carrier. TS_CARR_ON isn't cleared if nothing is open, * so it would live until the next open even if carrier drops. * o Restore TS_WOPEN since it is useful in pstat. It must be cleared * only when _all_ openers leave open(). */ #include "opt_compat.h" #include #include #include #include #include #include #include #if defined(COMPAT_43) || defined(COMPAT_SUNOS) #include #endif #include #define TTYDEFCHARS #include #undef TTYDEFCHARS #include #include #include #include #include #include #include #include #include #include #include #include #include #include MALLOC_DEFINE(M_TTYS, "ttys", "tty data structures"); static int proc_compare(struct proc *p1, struct proc *p2); static int ttnread(struct tty *tp); static void ttyecho(int c, struct tty *tp); static int ttyoutput(int c, register struct tty *tp); static void ttypend(struct tty *tp); static void ttyretype(struct tty *tp); static void ttyrub(int c, struct tty *tp); static void ttyrubo(struct tty *tp, int cnt); static void ttyunblock(struct tty *tp); static int ttywflush(struct tty *tp); static int filt_ttyread(struct knote *kn, long hint); static void filt_ttyrdetach(struct knote *kn); static int filt_ttywrite(struct knote *kn, long hint); static void filt_ttywdetach(struct knote *kn); /* * Table with character classes and parity. The 8th bit indicates parity, * the 7th bit indicates the character is an alphameric or underscore (for * ALTWERASE), and the low 6 bits indicate delay type. If the low 6 bits * are 0 then the character needs no special processing on output; classes * other than 0 might be translated or (not currently) require delays. */ #define E 0x00 /* Even parity. */ #define O 0x80 /* Odd parity. */ #define PARITY(c) (char_type[c] & O) #define ALPHA 0x40 /* Alpha or underscore. */ #define ISALPHA(c) (char_type[(c) & TTY_CHARMASK] & ALPHA) #define CCLASSMASK 0x3f #define CCLASS(c) (char_type[c] & CCLASSMASK) #define BS BACKSPACE #define CC CONTROL #define CR RETURN #define NA ORDINARY | ALPHA #define NL NEWLINE #define NO ORDINARY #define TB TAB #define VT VTAB static u_char const char_type[] = { E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* nul - bel */ O|BS, E|TB, E|NL, O|CC, E|VT, O|CR, O|CC, E|CC, /* bs - si */ O|CC, E|CC, E|CC, O|CC, E|CC, O|CC, O|CC, E|CC, /* dle - etb */ E|CC, O|CC, O|CC, E|CC, O|CC, E|CC, E|CC, O|CC, /* can - us */ O|NO, E|NO, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* sp - ' */ E|NO, O|NO, O|NO, E|NO, O|NO, E|NO, E|NO, O|NO, /* ( - / */ E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* 0 - 7 */ O|NA, E|NA, E|NO, O|NO, E|NO, O|NO, O|NO, E|NO, /* 8 - ? */ O|NO, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* @ - G */ E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* H - O */ E|NA, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* P - W */ O|NA, E|NA, E|NA, O|NO, E|NO, O|NO, O|NO, O|NA, /* X - _ */ E|NO, O|NA, O|NA, E|NA, O|NA, E|NA, E|NA, O|NA, /* ` - g */ O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* h - o */ O|NA, E|NA, E|NA, O|NA, E|NA, O|NA, O|NA, E|NA, /* p - w */ E|NA, O|NA, O|NA, E|NO, O|NO, E|NO, E|NO, O|CC, /* x - del */ /* * Meta chars; should be settable per character set; * for now, treat them all as normal characters. */ NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, }; #undef BS #undef CC #undef CR #undef NA #undef NL #undef NO #undef TB #undef VT /* Macros to clear/set/test flags. */ #define SET(t, f) (t) |= (f) #define CLR(t, f) (t) &= ~(f) #define ISSET(t, f) ((t) & (f)) #undef MAX_INPUT /* XXX wrong in */ #define MAX_INPUT TTYHOG /* XXX limit is usually larger for !ICANON */ /* * list of struct tty where pstat(8) can pick it up with sysctl */ static SLIST_HEAD(, tty) tty_list; static int drainwait = 5*60; SYSCTL_INT(_kern, OID_AUTO, drainwait, CTLFLAG_RW, &drainwait, 0, "Output drain timeout in seconds"); /* * Initial open of tty, or (re)entry to standard tty line discipline. */ int ttyopen(device, tp) dev_t device; register struct tty *tp; { int s; s = spltty(); tp->t_dev = device; if (!ISSET(tp->t_state, TS_ISOPEN)) { SET(tp->t_state, TS_ISOPEN); if (ISSET(tp->t_cflag, CLOCAL)) SET(tp->t_state, TS_CONNECTED); bzero(&tp->t_winsize, sizeof(tp->t_winsize)); } /* XXX don't hang forever on output */ if (tp->t_timeout < 0) tp->t_timeout = drainwait*hz; ttsetwater(tp); splx(s); return (0); } /* * Handle close() on a tty line: flush and set to initial state, * bumping generation number so that pending read/write calls * can detect recycling of the tty. * XXX our caller should have done `spltty(); l_close(); ttyclose();' * and l_close() should have flushed, but we repeat the spltty() and * the flush in case there are buggy callers. */ int ttyclose(tp) register struct tty *tp; { int s; funsetown(tp->t_sigio); s = spltty(); if (constty == tp) constty = NULL; ttyflush(tp, FREAD | FWRITE); clist_free_cblocks(&tp->t_canq); clist_free_cblocks(&tp->t_outq); clist_free_cblocks(&tp->t_rawq); tp->t_gen++; tp->t_line = TTYDISC; tp->t_pgrp = NULL; tp->t_session = NULL; tp->t_state = 0; splx(s); return (0); } #define FLUSHQ(q) { \ if ((q)->c_cc) \ ndflush(q, (q)->c_cc); \ } /* Is 'c' a line delimiter ("break" character)? */ #define TTBREAKC(c, lflag) \ ((c) == '\n' || (((c) == cc[VEOF] || \ (c) == cc[VEOL] || ((c) == cc[VEOL2] && lflag & IEXTEN)) && \ (c) != _POSIX_VDISABLE)) /* * Process input of a single character received on a tty. */ int ttyinput(c, tp) register int c; register struct tty *tp; { register tcflag_t iflag, lflag; register cc_t *cc; int i, err; /* * If input is pending take it first. */ lflag = tp->t_lflag; if (ISSET(lflag, PENDIN)) ttypend(tp); /* * Gather stats. */ if (ISSET(lflag, ICANON)) { ++tk_cancc; ++tp->t_cancc; } else { ++tk_rawcc; ++tp->t_rawcc; } ++tk_nin; /* * Block further input iff: * current input > threshold AND input is available to user program * AND input flow control is enabled and not yet invoked. * The 3 is slop for PARMRK. */ iflag = tp->t_iflag; if (tp->t_rawq.c_cc + tp->t_canq.c_cc > tp->t_ihiwat - 3 && (!ISSET(lflag, ICANON) || tp->t_canq.c_cc != 0) && (ISSET(tp->t_cflag, CRTS_IFLOW) || ISSET(iflag, IXOFF)) && !ISSET(tp->t_state, TS_TBLOCK)) ttyblock(tp); /* Handle exceptional conditions (break, parity, framing). */ cc = tp->t_cc; err = (ISSET(c, TTY_ERRORMASK)); if (err) { CLR(c, TTY_ERRORMASK); if (ISSET(err, TTY_BI)) { if (ISSET(iflag, IGNBRK)) return (0); if (ISSET(iflag, BRKINT)) { ttyflush(tp, FREAD | FWRITE); if (tp->t_pgrp != NULL) { PGRP_LOCK(tp->t_pgrp); pgsignal(tp->t_pgrp, SIGINT, 1); PGRP_UNLOCK(tp->t_pgrp); } goto endcase; } if (ISSET(iflag, PARMRK)) goto parmrk; } else if ((ISSET(err, TTY_PE) && ISSET(iflag, INPCK)) || ISSET(err, TTY_FE)) { if (ISSET(iflag, IGNPAR)) return (0); else if (ISSET(iflag, PARMRK)) { parmrk: if (tp->t_rawq.c_cc + tp->t_canq.c_cc > MAX_INPUT - 3) goto input_overflow; (void)putc(0377 | TTY_QUOTE, &tp->t_rawq); (void)putc(0 | TTY_QUOTE, &tp->t_rawq); (void)putc(c | TTY_QUOTE, &tp->t_rawq); goto endcase; } else c = 0; } } if (!ISSET(tp->t_state, TS_TYPEN) && ISSET(iflag, ISTRIP)) CLR(c, 0x80); if (!ISSET(lflag, EXTPROC)) { /* * Check for literal nexting very first */ if (ISSET(tp->t_state, TS_LNCH)) { SET(c, TTY_QUOTE); CLR(tp->t_state, TS_LNCH); } /* * Scan for special characters. This code * is really just a big case statement with * non-constant cases. The bottom of the * case statement is labeled ``endcase'', so goto * it after a case match, or similar. */ /* * Control chars which aren't controlled * by ICANON, ISIG, or IXON. */ if (ISSET(lflag, IEXTEN)) { if (CCEQ(cc[VLNEXT], c)) { if (ISSET(lflag, ECHO)) { if (ISSET(lflag, ECHOE)) { (void)ttyoutput('^', tp); (void)ttyoutput('\b', tp); } else ttyecho(c, tp); } SET(tp->t_state, TS_LNCH); goto endcase; } if (CCEQ(cc[VDISCARD], c)) { if (ISSET(lflag, FLUSHO)) CLR(tp->t_lflag, FLUSHO); else { ttyflush(tp, FWRITE); ttyecho(c, tp); if (tp->t_rawq.c_cc + tp->t_canq.c_cc) ttyretype(tp); SET(tp->t_lflag, FLUSHO); } goto startoutput; } } /* * Signals. */ if (ISSET(lflag, ISIG)) { if (CCEQ(cc[VINTR], c) || CCEQ(cc[VQUIT], c)) { if (!ISSET(lflag, NOFLSH)) ttyflush(tp, FREAD | FWRITE); ttyecho(c, tp); if (tp->t_pgrp != NULL) { PGRP_LOCK(tp->t_pgrp); pgsignal(tp->t_pgrp, CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1); PGRP_UNLOCK(tp->t_pgrp); } goto endcase; } if (CCEQ(cc[VSUSP], c)) { if (!ISSET(lflag, NOFLSH)) ttyflush(tp, FREAD); ttyecho(c, tp); if (tp->t_pgrp != NULL) { PGRP_LOCK(tp->t_pgrp); pgsignal(tp->t_pgrp, SIGTSTP, 1); PGRP_UNLOCK(tp->t_pgrp); } goto endcase; } } /* * Handle start/stop characters. */ if (ISSET(iflag, IXON)) { if (CCEQ(cc[VSTOP], c)) { if (!ISSET(tp->t_state, TS_TTSTOP)) { SET(tp->t_state, TS_TTSTOP); (*tp->t_stop)(tp, 0); return (0); } if (!CCEQ(cc[VSTART], c)) return (0); /* * if VSTART == VSTOP then toggle */ goto endcase; } if (CCEQ(cc[VSTART], c)) goto restartoutput; } /* * IGNCR, ICRNL, & INLCR */ if (c == '\r') { if (ISSET(iflag, IGNCR)) return (0); else if (ISSET(iflag, ICRNL)) c = '\n'; } else if (c == '\n' && ISSET(iflag, INLCR)) c = '\r'; } if (!ISSET(tp->t_lflag, EXTPROC) && ISSET(lflag, ICANON)) { /* * From here on down canonical mode character * processing takes place. */ /* * erase or erase2 (^H / ^?) */ if (CCEQ(cc[VERASE], c) || CCEQ(cc[VERASE2], c) ) { if (tp->t_rawq.c_cc) ttyrub(unputc(&tp->t_rawq), tp); goto endcase; } /* * kill (^U) */ if (CCEQ(cc[VKILL], c)) { if (ISSET(lflag, ECHOKE) && tp->t_rawq.c_cc == tp->t_rocount && !ISSET(lflag, ECHOPRT)) while (tp->t_rawq.c_cc) ttyrub(unputc(&tp->t_rawq), tp); else { ttyecho(c, tp); if (ISSET(lflag, ECHOK) || ISSET(lflag, ECHOKE)) ttyecho('\n', tp); FLUSHQ(&tp->t_rawq); tp->t_rocount = 0; } CLR(tp->t_state, TS_LOCAL); goto endcase; } /* * word erase (^W) */ if (CCEQ(cc[VWERASE], c) && ISSET(lflag, IEXTEN)) { int ctype; /* * erase whitespace */ while ((c = unputc(&tp->t_rawq)) == ' ' || c == '\t') ttyrub(c, tp); if (c == -1) goto endcase; /* * erase last char of word and remember the * next chars type (for ALTWERASE) */ ttyrub(c, tp); c = unputc(&tp->t_rawq); if (c == -1) goto endcase; if (c == ' ' || c == '\t') { (void)putc(c, &tp->t_rawq); goto endcase; } ctype = ISALPHA(c); /* * erase rest of word */ do { ttyrub(c, tp); c = unputc(&tp->t_rawq); if (c == -1) goto endcase; } while (c != ' ' && c != '\t' && (!ISSET(lflag, ALTWERASE) || ISALPHA(c) == ctype)); (void)putc(c, &tp->t_rawq); goto endcase; } /* * reprint line (^R) */ if (CCEQ(cc[VREPRINT], c) && ISSET(lflag, IEXTEN)) { ttyretype(tp); goto endcase; } /* * ^T - kernel info and generate SIGINFO */ if (CCEQ(cc[VSTATUS], c) && ISSET(lflag, IEXTEN)) { if (ISSET(lflag, ISIG) && tp->t_pgrp != NULL) { PGRP_LOCK(tp->t_pgrp); pgsignal(tp->t_pgrp, SIGINFO, 1); PGRP_UNLOCK(tp->t_pgrp); } if (!ISSET(lflag, NOKERNINFO)) ttyinfo(tp); goto endcase; } } /* * Check for input buffer overflow */ if (tp->t_rawq.c_cc + tp->t_canq.c_cc >= MAX_INPUT) { input_overflow: if (ISSET(iflag, IMAXBEL)) { if (tp->t_outq.c_cc < tp->t_ohiwat) (void)ttyoutput(CTRL('g'), tp); } goto endcase; } if ( c == 0377 && ISSET(iflag, PARMRK) && !ISSET(iflag, ISTRIP) && ISSET(iflag, IGNBRK|IGNPAR) != (IGNBRK|IGNPAR)) (void)putc(0377 | TTY_QUOTE, &tp->t_rawq); /* * Put data char in q for user and * wakeup on seeing a line delimiter. */ if (putc(c, &tp->t_rawq) >= 0) { if (!ISSET(lflag, ICANON)) { ttwakeup(tp); ttyecho(c, tp); goto endcase; } if (TTBREAKC(c, lflag)) { tp->t_rocount = 0; catq(&tp->t_rawq, &tp->t_canq); ttwakeup(tp); } else if (tp->t_rocount++ == 0) tp->t_rocol = tp->t_column; if (ISSET(tp->t_state, TS_ERASE)) { /* * end of prterase \.../ */ CLR(tp->t_state, TS_ERASE); (void)ttyoutput('/', tp); } i = tp->t_column; ttyecho(c, tp); if (CCEQ(cc[VEOF], c) && ISSET(lflag, ECHO)) { /* * Place the cursor over the '^' of the ^D. */ i = imin(2, tp->t_column - i); while (i > 0) { (void)ttyoutput('\b', tp); i--; } } } endcase: /* * IXANY means allow any character to restart output. */ if (ISSET(tp->t_state, TS_TTSTOP) && !ISSET(iflag, IXANY) && cc[VSTART] != cc[VSTOP]) return (0); restartoutput: CLR(tp->t_lflag, FLUSHO); CLR(tp->t_state, TS_TTSTOP); startoutput: return (ttstart(tp)); } /* * Output a single character on a tty, doing output processing * as needed (expanding tabs, newline processing, etc.). * Returns < 0 if succeeds, otherwise returns char to resend. * Must be recursive. */ static int ttyoutput(c, tp) register int c; register struct tty *tp; { register tcflag_t oflag; register int col, s; oflag = tp->t_oflag; if (!ISSET(oflag, OPOST)) { if (ISSET(tp->t_lflag, FLUSHO)) return (-1); if (putc(c, &tp->t_outq)) return (c); tk_nout++; tp->t_outcc++; return (-1); } /* * Do tab expansion if OXTABS is set. Special case if we external * processing, we don't do the tab expansion because we'll probably * get it wrong. If tab expansion needs to be done, let it happen * externally. */ CLR(c, ~TTY_CHARMASK); if (c == '\t' && ISSET(oflag, OXTABS) && !ISSET(tp->t_lflag, EXTPROC)) { c = 8 - (tp->t_column & 7); if (!ISSET(tp->t_lflag, FLUSHO)) { s = spltty(); /* Don't interrupt tabs. */ c -= b_to_q(" ", c, &tp->t_outq); tk_nout += c; tp->t_outcc += c; splx(s); } tp->t_column += c; return (c ? -1 : '\t'); } if (c == CEOT && ISSET(oflag, ONOEOT)) return (-1); /* * Newline translation: if ONLCR is set, * translate newline into "\r\n". */ if (c == '\n' && ISSET(tp->t_oflag, ONLCR)) { tk_nout++; tp->t_outcc++; if (!ISSET(tp->t_lflag, FLUSHO) && putc('\r', &tp->t_outq)) return (c); } /* If OCRNL is set, translate "\r" into "\n". */ else if (c == '\r' && ISSET(tp->t_oflag, OCRNL)) c = '\n'; /* If ONOCR is set, don't transmit CRs when on column 0. */ else if (c == '\r' && ISSET(tp->t_oflag, ONOCR) && tp->t_column == 0) return (-1); tk_nout++; tp->t_outcc++; if (!ISSET(tp->t_lflag, FLUSHO) && putc(c, &tp->t_outq)) return (c); col = tp->t_column; switch (CCLASS(c)) { case BACKSPACE: if (col > 0) --col; break; case CONTROL: break; case NEWLINE: if (ISSET(tp->t_oflag, ONLCR | ONLRET)) col = 0; break; case RETURN: col = 0; break; case ORDINARY: ++col; break; case TAB: col = (col + 8) & ~7; break; } tp->t_column = col; return (-1); } /* * Ioctls for all tty devices. Called after line-discipline specific ioctl * has been called to do discipline-specific functions and/or reject any * of these ioctl commands. */ /* ARGSUSED */ int ttioctl(tp, cmd, data, flag) register struct tty *tp; u_long cmd; int flag; void *data; { register struct proc *p; struct thread *td; struct pgrp *pgrp; int s, error; td = curthread; /* XXX */ p = td->td_proc; /* If the ioctl involves modification, hang if in the background. */ switch (cmd) { case TIOCCBRK: case TIOCCONS: case TIOCDRAIN: case TIOCEXCL: case TIOCFLUSH: #ifdef TIOCHPCL case TIOCHPCL: #endif case TIOCNXCL: case TIOCSBRK: case TIOCSCTTY: case TIOCSDRAINWAIT: case TIOCSETA: case TIOCSETAF: case TIOCSETAW: case TIOCSETD: case TIOCSPGRP: case TIOCSTART: case TIOCSTAT: case TIOCSTI: case TIOCSTOP: case TIOCSWINSZ: #if defined(COMPAT_43) || defined(COMPAT_SUNOS) case TIOCLBIC: case TIOCLBIS: case TIOCLSET: case TIOCSETC: case OTIOCSETD: case TIOCSETN: case TIOCSETP: case TIOCSLTC: #endif sx_slock(&proctree_lock); PROC_LOCK(p); while (isbackground(p, tp) && !(p->p_flag & P_PPWAIT) && !SIGISMEMBER(p->p_sigignore, SIGTTOU) && !SIGISMEMBER(p->p_sigmask, SIGTTOU)) { pgrp = p->p_pgrp; PROC_UNLOCK(p); if (pgrp->pg_jobc == 0) { sx_sunlock(&proctree_lock); return (EIO); } PGRP_LOCK(pgrp); sx_sunlock(&proctree_lock); pgsignal(pgrp, SIGTTOU, 1); PGRP_UNLOCK(pgrp); error = ttysleep(tp, &lbolt, TTOPRI | PCATCH, "ttybg1", 0); if (error) return (error); sx_slock(&proctree_lock); PROC_LOCK(p); } PROC_UNLOCK(p); sx_sunlock(&proctree_lock); break; } switch (cmd) { /* Process the ioctl. */ case FIOASYNC: /* set/clear async i/o */ s = spltty(); if (*(int *)data) SET(tp->t_state, TS_ASYNC); else CLR(tp->t_state, TS_ASYNC); splx(s); break; case FIONBIO: /* set/clear non-blocking i/o */ break; /* XXX: delete. */ case FIONREAD: /* get # bytes to read */ s = spltty(); *(int *)data = ttnread(tp); splx(s); break; case FIOSETOWN: /* * Policy -- Don't allow FIOSETOWN on someone else's * controlling tty */ if (tp->t_session != NULL && !isctty(p, tp)) return (ENOTTY); error = fsetown(*(int *)data, &tp->t_sigio); if (error) return (error); break; case FIOGETOWN: if (tp->t_session != NULL && !isctty(p, tp)) return (ENOTTY); *(int *)data = fgetown(tp->t_sigio); break; case TIOCEXCL: /* set exclusive use of tty */ s = spltty(); SET(tp->t_state, TS_XCLUDE); splx(s); break; case TIOCFLUSH: { /* flush buffers */ register int flags = *(int *)data; if (flags == 0) flags = FREAD | FWRITE; else flags &= FREAD | FWRITE; ttyflush(tp, flags); break; } case TIOCCONS: /* become virtual console */ if (*(int *)data) { struct nameidata nid; if (constty && constty != tp && ISSET(constty->t_state, TS_CONNECTED)) return (EBUSY); /* Ensure user can open the real console. */ NDINIT(&nid, LOOKUP, LOCKLEAF | FOLLOW, UIO_SYSSPACE, "/dev/console", td); if ((error = namei(&nid)) != 0) return (error); NDFREE(&nid, NDF_ONLY_PNBUF); error = VOP_ACCESS(nid.ni_vp, VREAD, td->td_ucred, td); vput(nid.ni_vp); if (error) return (error); constty = tp; } else if (tp == constty) constty = NULL; break; case TIOCDRAIN: /* wait till output drained */ error = ttywait(tp); if (error) return (error); break; case TIOCGETA: { /* get termios struct */ struct termios *t = (struct termios *)data; bcopy(&tp->t_termios, t, sizeof(struct termios)); break; } case TIOCGETD: /* get line discipline */ *(int *)data = tp->t_line; break; case TIOCGWINSZ: /* get window size */ *(struct winsize *)data = tp->t_winsize; break; case TIOCGPGRP: /* get pgrp of tty */ if (!isctty(p, tp)) return (ENOTTY); *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID; break; #ifdef TIOCHPCL case TIOCHPCL: /* hang up on last close */ s = spltty(); SET(tp->t_cflag, HUPCL); splx(s); break; #endif case TIOCNXCL: /* reset exclusive use of tty */ s = spltty(); CLR(tp->t_state, TS_XCLUDE); splx(s); break; case TIOCOUTQ: /* output queue size */ *(int *)data = tp->t_outq.c_cc; break; case TIOCSETA: /* set termios struct */ case TIOCSETAW: /* drain output, set */ case TIOCSETAF: { /* drn out, fls in, set */ register struct termios *t = (struct termios *)data; if (t->c_ispeed == 0) t->c_ispeed = t->c_ospeed; if (t->c_ispeed == 0) t->c_ispeed = tp->t_ospeed; if (t->c_ispeed == 0) return (EINVAL); s = spltty(); if (cmd == TIOCSETAW || cmd == TIOCSETAF) { error = ttywait(tp); if (error) { splx(s); return (error); } if (cmd == TIOCSETAF) ttyflush(tp, FREAD); } if (!ISSET(t->c_cflag, CIGNORE)) { /* * Set device hardware. */ if (tp->t_param && (error = (*tp->t_param)(tp, t))) { splx(s); return (error); } if (ISSET(t->c_cflag, CLOCAL) && !ISSET(tp->t_cflag, CLOCAL)) { /* * XXX disconnections would be too hard to * get rid of without this kludge. The only * way to get rid of controlling terminals * is to exit from the session leader. */ CLR(tp->t_state, TS_ZOMBIE); wakeup(TSA_CARR_ON(tp)); ttwakeup(tp); ttwwakeup(tp); } if ((ISSET(tp->t_state, TS_CARR_ON) || ISSET(t->c_cflag, CLOCAL)) && !ISSET(tp->t_state, TS_ZOMBIE)) SET(tp->t_state, TS_CONNECTED); else CLR(tp->t_state, TS_CONNECTED); tp->t_cflag = t->c_cflag; tp->t_ispeed = t->c_ispeed; if (t->c_ospeed != 0) tp->t_ospeed = t->c_ospeed; ttsetwater(tp); } if (ISSET(t->c_lflag, ICANON) != ISSET(tp->t_lflag, ICANON) && cmd != TIOCSETAF) { if (ISSET(t->c_lflag, ICANON)) SET(tp->t_lflag, PENDIN); else { /* * XXX we really shouldn't allow toggling * ICANON while we're in a non-termios line * discipline. Now we have to worry about * panicing for a null queue. */ if (tp->t_canq.c_cbreserved > 0 && tp->t_rawq.c_cbreserved > 0) { catq(&tp->t_rawq, &tp->t_canq); /* * XXX the queue limits may be * different, so the old queue * swapping method no longer works. */ catq(&tp->t_canq, &tp->t_rawq); } CLR(tp->t_lflag, PENDIN); } ttwakeup(tp); } tp->t_iflag = t->c_iflag; tp->t_oflag = t->c_oflag; /* * Make the EXTPROC bit read only. */ if (ISSET(tp->t_lflag, EXTPROC)) SET(t->c_lflag, EXTPROC); else CLR(t->c_lflag, EXTPROC); tp->t_lflag = t->c_lflag | ISSET(tp->t_lflag, PENDIN); if (t->c_cc[VMIN] != tp->t_cc[VMIN] || t->c_cc[VTIME] != tp->t_cc[VTIME]) ttwakeup(tp); bcopy(t->c_cc, tp->t_cc, sizeof(t->c_cc)); splx(s); break; } case TIOCSETD: { /* set line discipline */ register int t = *(int *)data; dev_t device = tp->t_dev; if ((u_int)t >= nlinesw) return (ENXIO); if (t != tp->t_line) { s = spltty(); (*linesw[tp->t_line].l_close)(tp, flag); error = (*linesw[t].l_open)(device, tp); if (error) { (void)(*linesw[tp->t_line].l_open)(device, tp); splx(s); return (error); } tp->t_line = t; splx(s); } break; } case TIOCSTART: /* start output, like ^Q */ s = spltty(); if (ISSET(tp->t_state, TS_TTSTOP) || ISSET(tp->t_lflag, FLUSHO)) { CLR(tp->t_lflag, FLUSHO); CLR(tp->t_state, TS_TTSTOP); ttstart(tp); } splx(s); break; case TIOCSTI: /* simulate terminal input */ if ((flag & FREAD) == 0 && suser(td)) return (EPERM); if (!isctty(p, tp) && suser(td)) return (EACCES); s = spltty(); (*linesw[tp->t_line].l_rint)(*(u_char *)data, tp); splx(s); break; case TIOCSTOP: /* stop output, like ^S */ s = spltty(); if (!ISSET(tp->t_state, TS_TTSTOP)) { SET(tp->t_state, TS_TTSTOP); (*tp->t_stop)(tp, 0); } splx(s); break; case TIOCSCTTY: /* become controlling tty */ /* Session ctty vnode pointer set in vnode layer. */ sx_slock(&proctree_lock); if (!SESS_LEADER(p) || ((p->p_session->s_ttyvp || tp->t_session) && (tp->t_session != p->p_session))) { sx_sunlock(&proctree_lock); return (EPERM); } tp->t_session = p->p_session; tp->t_pgrp = p->p_pgrp; SESS_LOCK(p->p_session); p->p_session->s_ttyp = tp; SESS_UNLOCK(p->p_session); PROC_LOCK(p); p->p_flag |= P_CONTROLT; PROC_UNLOCK(p); sx_sunlock(&proctree_lock); break; case TIOCSPGRP: { /* set pgrp of tty */ sx_slock(&proctree_lock); pgrp = pgfind(*(int *)data); if (!isctty(p, tp)) { if (pgrp != NULL) PGRP_UNLOCK(pgrp); sx_sunlock(&proctree_lock); return (ENOTTY); } if (pgrp == NULL) { sx_sunlock(&proctree_lock); return (EPERM); } PGRP_UNLOCK(pgrp); if (pgrp->pg_session != p->p_session) { sx_sunlock(&proctree_lock); return (EPERM); } sx_sunlock(&proctree_lock); tp->t_pgrp = pgrp; break; } case TIOCSTAT: /* simulate control-T */ s = spltty(); ttyinfo(tp); splx(s); break; case TIOCSWINSZ: /* set window size */ if (bcmp((caddr_t)&tp->t_winsize, data, sizeof (struct winsize))) { tp->t_winsize = *(struct winsize *)data; if (tp->t_pgrp != NULL) { PGRP_LOCK(tp->t_pgrp); pgsignal(tp->t_pgrp, SIGWINCH, 1); PGRP_UNLOCK(tp->t_pgrp); } } break; case TIOCSDRAINWAIT: error = suser(td); if (error) return (error); tp->t_timeout = *(int *)data * hz; wakeup(TSA_OCOMPLETE(tp)); wakeup(TSA_OLOWAT(tp)); break; case TIOCGDRAINWAIT: *(int *)data = tp->t_timeout / hz; break; default: #if defined(COMPAT_43) || defined(COMPAT_SUNOS) return (ttcompat(tp, cmd, data, flag)); #else return (ENOIOCTL); #endif } return (0); } int ttypoll(dev, events, td) dev_t dev; int events; struct thread *td; { int s; int revents = 0; struct tty *tp; tp = dev->si_tty; if (tp == NULL) /* XXX used to return ENXIO, but that means true! */ return ((events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)) | POLLHUP); s = spltty(); if (events & (POLLIN | POLLRDNORM)) { if (ttnread(tp) > 0 || ISSET(tp->t_state, TS_ZOMBIE)) revents |= events & (POLLIN | POLLRDNORM); else selrecord(td, &tp->t_rsel); } if (events & (POLLOUT | POLLWRNORM)) { if ((tp->t_outq.c_cc <= tp->t_olowat && ISSET(tp->t_state, TS_CONNECTED)) || ISSET(tp->t_state, TS_ZOMBIE)) revents |= events & (POLLOUT | POLLWRNORM); else selrecord(td, &tp->t_wsel); } splx(s); return (revents); } static struct filterops ttyread_filtops = { 1, NULL, filt_ttyrdetach, filt_ttyread }; static struct filterops ttywrite_filtops = { 1, NULL, filt_ttywdetach, filt_ttywrite }; int ttykqfilter(dev, kn) dev_t dev; struct knote *kn; { struct tty *tp = dev->si_tty; struct klist *klist; int s; switch (kn->kn_filter) { case EVFILT_READ: klist = &tp->t_rsel.si_note; kn->kn_fop = &ttyread_filtops; break; case EVFILT_WRITE: klist = &tp->t_wsel.si_note; kn->kn_fop = &ttywrite_filtops; break; default: return (1); } kn->kn_hook = (caddr_t)dev; s = spltty(); SLIST_INSERT_HEAD(klist, kn, kn_selnext); splx(s); return (0); } static void filt_ttyrdetach(struct knote *kn) { struct tty *tp = ((dev_t)kn->kn_hook)->si_tty; int s = spltty(); SLIST_REMOVE(&tp->t_rsel.si_note, kn, knote, kn_selnext); splx(s); } static int filt_ttyread(struct knote *kn, long hint) { struct tty *tp = ((dev_t)kn->kn_hook)->si_tty; kn->kn_data = ttnread(tp); if (ISSET(tp->t_state, TS_ZOMBIE)) { kn->kn_flags |= EV_EOF; return (1); } return (kn->kn_data > 0); } static void filt_ttywdetach(struct knote *kn) { struct tty *tp = ((dev_t)kn->kn_hook)->si_tty; int s = spltty(); SLIST_REMOVE(&tp->t_wsel.si_note, kn, knote, kn_selnext); splx(s); } static int filt_ttywrite(kn, hint) struct knote *kn; long hint; { struct tty *tp = ((dev_t)kn->kn_hook)->si_tty; kn->kn_data = tp->t_outq.c_cc; if (ISSET(tp->t_state, TS_ZOMBIE)) return (1); return (kn->kn_data <= tp->t_olowat && ISSET(tp->t_state, TS_CONNECTED)); } /* * Must be called at spltty(). */ static int ttnread(tp) struct tty *tp; { int nread; if (ISSET(tp->t_lflag, PENDIN)) ttypend(tp); nread = tp->t_canq.c_cc; if (!ISSET(tp->t_lflag, ICANON)) { nread += tp->t_rawq.c_cc; if (nread < tp->t_cc[VMIN] && tp->t_cc[VTIME] == 0) nread = 0; } return (nread); } /* * Wait for output to drain. */ int ttywait(tp) register struct tty *tp; { int error, s; error = 0; s = spltty(); while ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) && ISSET(tp->t_state, TS_CONNECTED) && tp->t_oproc) { (*tp->t_oproc)(tp); if ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) && ISSET(tp->t_state, TS_CONNECTED)) { SET(tp->t_state, TS_SO_OCOMPLETE); error = ttysleep(tp, TSA_OCOMPLETE(tp), TTOPRI | PCATCH, "ttywai", tp->t_timeout); if (error) { if (error == EWOULDBLOCK) error = EIO; break; } } else break; } if (!error && (tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY))) error = EIO; splx(s); return (error); } /* * Flush if successfully wait. */ static int ttywflush(tp) struct tty *tp; { int error; if ((error = ttywait(tp)) == 0) ttyflush(tp, FREAD); return (error); } /* * Flush tty read and/or write queues, notifying anyone waiting. */ void ttyflush(tp, rw) register struct tty *tp; int rw; { register int s; s = spltty(); #if 0 again: #endif if (rw & FWRITE) { FLUSHQ(&tp->t_outq); CLR(tp->t_state, TS_TTSTOP); } (*tp->t_stop)(tp, rw); if (rw & FREAD) { FLUSHQ(&tp->t_canq); FLUSHQ(&tp->t_rawq); CLR(tp->t_lflag, PENDIN); tp->t_rocount = 0; tp->t_rocol = 0; CLR(tp->t_state, TS_LOCAL); ttwakeup(tp); if (ISSET(tp->t_state, TS_TBLOCK)) { if (rw & FWRITE) FLUSHQ(&tp->t_outq); ttyunblock(tp); /* * Don't let leave any state that might clobber the * next line discipline (although we should do more * to send the START char). Not clearing the state * may have caused the "putc to a clist with no * reserved cblocks" panic/printf. */ CLR(tp->t_state, TS_TBLOCK); #if 0 /* forget it, sleeping isn't always safe and we don't know when it is */ if (ISSET(tp->t_iflag, IXOFF)) { /* * XXX wait a bit in the hope that the stop * character (if any) will go out. Waiting * isn't good since it allows races. This * will be fixed when the stop character is * put in a special queue. Don't bother with * the checks in ttywait() since the timeout * will save us. */ SET(tp->t_state, TS_SO_OCOMPLETE); ttysleep(tp, TSA_OCOMPLETE(tp), TTOPRI, "ttyfls", hz / 10); /* * Don't try sending the stop character again. */ CLR(tp->t_state, TS_TBLOCK); goto again; } #endif } } if (rw & FWRITE) { FLUSHQ(&tp->t_outq); ttwwakeup(tp); } splx(s); } /* * Copy in the default termios characters. */ void termioschars(t) struct termios *t; { bcopy(ttydefchars, t->c_cc, sizeof t->c_cc); } /* * Old interface. */ void ttychars(tp) struct tty *tp; { termioschars(&tp->t_termios); } /* * Handle input high water. Send stop character for the IXOFF case. Turn * on our input flow control bit and propagate the changes to the driver. * XXX the stop character should be put in a special high priority queue. */ void ttyblock(tp) struct tty *tp; { SET(tp->t_state, TS_TBLOCK); if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTOP] != _POSIX_VDISABLE && putc(tp->t_cc[VSTOP], &tp->t_outq) != 0) CLR(tp->t_state, TS_TBLOCK); /* try again later */ ttstart(tp); } /* * Handle input low water. Send start character for the IXOFF case. Turn * off our input flow control bit and propagate the changes to the driver. * XXX the start character should be put in a special high priority queue. */ static void ttyunblock(tp) struct tty *tp; { CLR(tp->t_state, TS_TBLOCK); if (ISSET(tp->t_iflag, IXOFF) && tp->t_cc[VSTART] != _POSIX_VDISABLE && putc(tp->t_cc[VSTART], &tp->t_outq) != 0) SET(tp->t_state, TS_TBLOCK); /* try again later */ ttstart(tp); } #ifdef notyet /* Not used by any current (i386) drivers. */ /* * Restart after an inter-char delay. */ void ttrstrt(tp_arg) void *tp_arg; { struct tty *tp; int s; KASSERT(tp_arg != NULL, ("ttrstrt")); tp = tp_arg; s = spltty(); CLR(tp->t_state, TS_TIMEOUT); ttstart(tp); splx(s); } #endif int ttstart(tp) struct tty *tp; { if (tp->t_oproc != NULL) /* XXX: Kludge for pty. */ (*tp->t_oproc)(tp); return (0); } /* * "close" a line discipline */ int ttylclose(tp, flag) struct tty *tp; int flag; { if (flag & FNONBLOCK || ttywflush(tp)) ttyflush(tp, FREAD | FWRITE); return (0); } /* * Handle modem control transition on a tty. * Flag indicates new state of carrier. * Returns 0 if the line should be turned off, otherwise 1. */ int ttymodem(tp, flag) register struct tty *tp; int flag; { if (ISSET(tp->t_state, TS_CARR_ON) && ISSET(tp->t_cflag, MDMBUF)) { /* * MDMBUF: do flow control according to carrier flag * XXX TS_CAR_OFLOW doesn't do anything yet. TS_TTSTOP * works if IXON and IXANY are clear. */ if (flag) { CLR(tp->t_state, TS_CAR_OFLOW); CLR(tp->t_state, TS_TTSTOP); ttstart(tp); } else if (!ISSET(tp->t_state, TS_CAR_OFLOW)) { SET(tp->t_state, TS_CAR_OFLOW); SET(tp->t_state, TS_TTSTOP); (*tp->t_stop)(tp, 0); } } else if (flag == 0) { /* * Lost carrier. */ CLR(tp->t_state, TS_CARR_ON); if (ISSET(tp->t_state, TS_ISOPEN) && !ISSET(tp->t_cflag, CLOCAL)) { SET(tp->t_state, TS_ZOMBIE); CLR(tp->t_state, TS_CONNECTED); if (tp->t_session) { sx_slock(&proctree_lock); if (tp->t_session->s_leader) { struct proc *p; p = tp->t_session->s_leader; PROC_LOCK(p); psignal(p, SIGHUP); PROC_UNLOCK(p); } sx_sunlock(&proctree_lock); } ttyflush(tp, FREAD | FWRITE); return (0); } } else { /* * Carrier now on. */ SET(tp->t_state, TS_CARR_ON); if (!ISSET(tp->t_state, TS_ZOMBIE)) SET(tp->t_state, TS_CONNECTED); wakeup(TSA_CARR_ON(tp)); ttwakeup(tp); ttwwakeup(tp); } return (1); } /* * Reinput pending characters after state switch * call at spltty(). */ static void ttypend(tp) register struct tty *tp; { struct clist tq; register int c; CLR(tp->t_lflag, PENDIN); SET(tp->t_state, TS_TYPEN); /* * XXX this assumes too much about clist internals. It may even * fail if the cblock slush pool is empty. We can't allocate more * cblocks here because we are called from an interrupt handler * and clist_alloc_cblocks() can wait. */ tq = tp->t_rawq; bzero(&tp->t_rawq, sizeof tp->t_rawq); tp->t_rawq.c_cbmax = tq.c_cbmax; tp->t_rawq.c_cbreserved = tq.c_cbreserved; while ((c = getc(&tq)) >= 0) ttyinput(c, tp); CLR(tp->t_state, TS_TYPEN); } /* * Process a read call on a tty device. */ int ttread(tp, uio, flag) register struct tty *tp; struct uio *uio; int flag; { register struct clist *qp; register int c; register tcflag_t lflag; register cc_t *cc = tp->t_cc; register struct proc *p = curproc; int s, first, error = 0; int has_stime = 0, last_cc = 0; long slp = 0; /* XXX this should be renamed `timo'. */ struct timeval stime; struct pgrp *pg; loop: s = spltty(); lflag = tp->t_lflag; /* * take pending input first */ if (ISSET(lflag, PENDIN)) { ttypend(tp); splx(s); /* reduce latency */ s = spltty(); lflag = tp->t_lflag; /* XXX ttypend() clobbers it */ } /* * Hang process if it's in the background. */ if (isbackground(p, tp)) { splx(s); sx_slock(&proctree_lock); PROC_LOCK(p); if (SIGISMEMBER(p->p_sigignore, SIGTTIN) || SIGISMEMBER(p->p_sigmask, SIGTTIN) || (p->p_flag & P_PPWAIT) || p->p_pgrp->pg_jobc == 0) { PROC_UNLOCK(p); sx_sunlock(&proctree_lock); return (EIO); } pg = p->p_pgrp; PROC_UNLOCK(p); PGRP_LOCK(pg); sx_sunlock(&proctree_lock); pgsignal(pg, SIGTTIN, 1); PGRP_UNLOCK(pg); error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, "ttybg2", 0); if (error) return (error); goto loop; } if (ISSET(tp->t_state, TS_ZOMBIE)) { splx(s); return (0); /* EOF */ } /* * If canonical, use the canonical queue, * else use the raw queue. * * (should get rid of clists...) */ qp = ISSET(lflag, ICANON) ? &tp->t_canq : &tp->t_rawq; if (flag & IO_NDELAY) { if (qp->c_cc > 0) goto read; if (!ISSET(lflag, ICANON) && cc[VMIN] == 0) { splx(s); return (0); } splx(s); return (EWOULDBLOCK); } if (!ISSET(lflag, ICANON)) { int m = cc[VMIN]; long t = cc[VTIME]; struct timeval timecopy; /* * Check each of the four combinations. * (m > 0 && t == 0) is the normal read case. * It should be fairly efficient, so we check that and its * companion case (m == 0 && t == 0) first. * For the other two cases, we compute the target sleep time * into slp. */ if (t == 0) { if (qp->c_cc < m) goto sleep; if (qp->c_cc > 0) goto read; /* m, t and qp->c_cc are all 0. 0 is enough input. */ splx(s); return (0); } t *= 100000; /* time in us */ #define diff(t1, t2) (((t1).tv_sec - (t2).tv_sec) * 1000000 + \ ((t1).tv_usec - (t2).tv_usec)) if (m > 0) { if (qp->c_cc <= 0) goto sleep; if (qp->c_cc >= m) goto read; getmicrotime(&timecopy); if (!has_stime) { /* first character, start timer */ has_stime = 1; stime = timecopy; slp = t; } else if (qp->c_cc > last_cc) { /* got a character, restart timer */ stime = timecopy; slp = t; } else { /* nothing, check expiration */ slp = t - diff(timecopy, stime); if (slp <= 0) goto read; } last_cc = qp->c_cc; } else { /* m == 0 */ if (qp->c_cc > 0) goto read; getmicrotime(&timecopy); if (!has_stime) { has_stime = 1; stime = timecopy; slp = t; } else { slp = t - diff(timecopy, stime); if (slp <= 0) { /* Timed out, but 0 is enough input. */ splx(s); return (0); } } } #undef diff /* * Rounding down may make us wake up just short * of the target, so we round up. * The formula is ceiling(slp * hz/1000000). * 32-bit arithmetic is enough for hz < 169. * XXX see tvtohz() for how to avoid overflow if hz * is large (divide by `tick' and/or arrange to * use tvtohz() if hz is large). */ slp = (long) (((u_long)slp * hz) + 999999) / 1000000; goto sleep; } if (qp->c_cc <= 0) { sleep: /* * There is no input, or not enough input and we can block. */ error = ttysleep(tp, TSA_HUP_OR_INPUT(tp), TTIPRI | PCATCH, ISSET(tp->t_state, TS_CONNECTED) ? "ttyin" : "ttyhup", (int)slp); splx(s); if (error == EWOULDBLOCK) error = 0; else if (error) return (error); /* * XXX what happens if another process eats some input * while we are asleep (not just here)? It would be * safest to detect changes and reset our state variables * (has_stime and last_cc). */ slp = 0; goto loop; } read: splx(s); /* * Input present, check for input mapping and processing. */ first = 1; if (ISSET(lflag, ICANON | ISIG)) goto slowcase; for (;;) { char ibuf[IBUFSIZ]; int icc; icc = imin(uio->uio_resid, IBUFSIZ); icc = q_to_b(qp, ibuf, icc); if (icc <= 0) { if (first) goto loop; break; } error = uiomove(ibuf, icc, uio); /* * XXX if there was an error then we should ungetc() the * unmoved chars and reduce icc here. */ if (error) break; if (uio->uio_resid == 0) break; first = 0; } goto out; slowcase: for (;;) { c = getc(qp); if (c < 0) { if (first) goto loop; break; } /* * delayed suspend (^Y) */ if (CCEQ(cc[VDSUSP], c) && ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG)) { if (tp->t_pgrp != NULL) { PGRP_LOCK(tp->t_pgrp); pgsignal(tp->t_pgrp, SIGTSTP, 1); PGRP_UNLOCK(tp->t_pgrp); } if (first) { error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, "ttybg3", 0); if (error) break; goto loop; } break; } /* * Interpret EOF only in canonical mode. */ if (CCEQ(cc[VEOF], c) && ISSET(lflag, ICANON)) break; /* * Give user character. */ error = ureadc(c, uio); if (error) /* XXX should ungetc(c, qp). */ break; if (uio->uio_resid == 0) break; /* * In canonical mode check for a "break character" * marking the end of a "line of input". */ if (ISSET(lflag, ICANON) && TTBREAKC(c, lflag)) break; first = 0; } out: /* * Look to unblock input now that (presumably) * the input queue has gone down. */ s = spltty(); if (ISSET(tp->t_state, TS_TBLOCK) && tp->t_rawq.c_cc + tp->t_canq.c_cc <= tp->t_ilowat) ttyunblock(tp); splx(s); return (error); } /* * Check the output queue on tp for space for a kernel message (from uprintf * or tprintf). Allow some space over the normal hiwater mark so we don't * lose messages due to normal flow control, but don't let the tty run amok. * Sleeps here are not interruptible, but we return prematurely if new signals * arrive. */ int ttycheckoutq(tp, wait) register struct tty *tp; int wait; { int hiwat, s; sigset_t oldmask; hiwat = tp->t_ohiwat; SIGEMPTYSET(oldmask); s = spltty(); if (wait) oldmask = curproc->p_siglist; if (tp->t_outq.c_cc > hiwat + OBUFSIZ + 100) while (tp->t_outq.c_cc > hiwat) { ttstart(tp); if (tp->t_outq.c_cc <= hiwat) break; if (!(wait && SIGSETEQ(curproc->p_siglist, oldmask))) { splx(s); return (0); } SET(tp->t_state, TS_SO_OLOWAT); tsleep(TSA_OLOWAT(tp), PZERO - 1, "ttoutq", hz); } splx(s); return (1); } /* * Process a write call on a tty device. */ int ttwrite(tp, uio, flag) register struct tty *tp; register struct uio *uio; int flag; { register char *cp = NULL; register int cc, ce; register struct proc *p; int i, hiwat, cnt, error, s; char obuf[OBUFSIZ]; hiwat = tp->t_ohiwat; cnt = uio->uio_resid; error = 0; cc = 0; loop: s = spltty(); if (ISSET(tp->t_state, TS_ZOMBIE)) { splx(s); if (uio->uio_resid == cnt) error = EIO; goto out; } if (!ISSET(tp->t_state, TS_CONNECTED)) { if (flag & IO_NDELAY) { splx(s); error = EWOULDBLOCK; goto out; } error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH, "ttydcd", 0); splx(s); if (error) goto out; goto loop; } splx(s); /* * Hang the process if it's in the background. */ p = curproc; sx_slock(&proctree_lock); PROC_LOCK(p); if (isbackground(p, tp) && ISSET(tp->t_lflag, TOSTOP) && !(p->p_flag & P_PPWAIT) && !SIGISMEMBER(p->p_sigignore, SIGTTOU) && !SIGISMEMBER(p->p_sigmask, SIGTTOU)) { if (p->p_pgrp->pg_jobc == 0) { PROC_UNLOCK(p); sx_sunlock(&proctree_lock); error = EIO; goto out; } PROC_UNLOCK(p); PGRP_LOCK(p->p_pgrp); sx_sunlock(&proctree_lock); pgsignal(p->p_pgrp, SIGTTOU, 1); PGRP_UNLOCK(p->p_pgrp); error = ttysleep(tp, &lbolt, TTIPRI | PCATCH, "ttybg4", 0); if (error) goto out; goto loop; } else { PROC_UNLOCK(p); sx_sunlock(&proctree_lock); } /* * Process the user's data in at most OBUFSIZ chunks. Perform any * output translation. Keep track of high water mark, sleep on * overflow awaiting device aid in acquiring new space. */ while (uio->uio_resid > 0 || cc > 0) { if (ISSET(tp->t_lflag, FLUSHO)) { uio->uio_resid = 0; return (0); } if (tp->t_outq.c_cc > hiwat) goto ovhiwat; /* * Grab a hunk of data from the user, unless we have some * leftover from last time. */ if (cc == 0) { cc = imin(uio->uio_resid, OBUFSIZ); cp = obuf; error = uiomove(cp, cc, uio); if (error) { cc = 0; break; } } /* * If nothing fancy need be done, grab those characters we * can handle without any of ttyoutput's processing and * just transfer them to the output q. For those chars * which require special processing (as indicated by the * bits in char_type), call ttyoutput. After processing * a hunk of data, look for FLUSHO so ^O's will take effect * immediately. */ while (cc > 0) { if (!ISSET(tp->t_oflag, OPOST)) ce = cc; else { ce = cc - scanc((u_int)cc, (u_char *)cp, char_type, CCLASSMASK); /* * If ce is zero, then we're processing * a special character through ttyoutput. */ if (ce == 0) { tp->t_rocount = 0; if (ttyoutput(*cp, tp) >= 0) { /* No Clists, wait a bit. */ ttstart(tp); if (flag & IO_NDELAY) { error = EWOULDBLOCK; goto out; } error = ttysleep(tp, &lbolt, TTOPRI|PCATCH, "ttybf1", 0); if (error) goto out; goto loop; } cp++; cc--; if (ISSET(tp->t_lflag, FLUSHO) || tp->t_outq.c_cc > hiwat) goto ovhiwat; continue; } } /* * A bunch of normal characters have been found. * Transfer them en masse to the output queue and * continue processing at the top of the loop. * If there are any further characters in this * <= OBUFSIZ chunk, the first should be a character * requiring special handling by ttyoutput. */ tp->t_rocount = 0; i = b_to_q(cp, ce, &tp->t_outq); ce -= i; tp->t_column += ce; cp += ce, cc -= ce, tk_nout += ce; tp->t_outcc += ce; if (i > 0) { /* No Clists, wait a bit. */ ttstart(tp); if (flag & IO_NDELAY) { error = EWOULDBLOCK; goto out; } error = ttysleep(tp, &lbolt, TTOPRI | PCATCH, "ttybf2", 0); if (error) goto out; goto loop; } if (ISSET(tp->t_lflag, FLUSHO) || tp->t_outq.c_cc > hiwat) break; } ttstart(tp); } out: /* * If cc is nonzero, we leave the uio structure inconsistent, as the * offset and iov pointers have moved forward, but it doesn't matter * (the call will either return short or restart with a new uio). */ uio->uio_resid += cc; return (error); ovhiwat: ttstart(tp); s = spltty(); /* * This can only occur if FLUSHO is set in t_lflag, * or if ttstart/oproc is synchronous (or very fast). */ if (tp->t_outq.c_cc <= hiwat) { splx(s); goto loop; } if (flag & IO_NDELAY) { splx(s); uio->uio_resid += cc; return (uio->uio_resid == cnt ? EWOULDBLOCK : 0); } SET(tp->t_state, TS_SO_OLOWAT); error = ttysleep(tp, TSA_OLOWAT(tp), TTOPRI | PCATCH, "ttywri", tp->t_timeout); splx(s); if (error == EWOULDBLOCK) error = EIO; if (error) goto out; goto loop; } /* * Rubout one character from the rawq of tp * as cleanly as possible. */ static void ttyrub(c, tp) register int c; register struct tty *tp; { register char *cp; register int savecol; int tabc, s; if (!ISSET(tp->t_lflag, ECHO) || ISSET(tp->t_lflag, EXTPROC)) return; CLR(tp->t_lflag, FLUSHO); if (ISSET(tp->t_lflag, ECHOE)) { if (tp->t_rocount == 0) { /* * Screwed by ttwrite; retype */ ttyretype(tp); return; } if (c == ('\t' | TTY_QUOTE) || c == ('\n' | TTY_QUOTE)) ttyrubo(tp, 2); else { CLR(c, ~TTY_CHARMASK); switch (CCLASS(c)) { case ORDINARY: ttyrubo(tp, 1); break; case BACKSPACE: case CONTROL: case NEWLINE: case RETURN: case VTAB: if (ISSET(tp->t_lflag, ECHOCTL)) ttyrubo(tp, 2); break; case TAB: if (tp->t_rocount < tp->t_rawq.c_cc) { ttyretype(tp); return; } s = spltty(); savecol = tp->t_column; SET(tp->t_state, TS_CNTTB); SET(tp->t_lflag, FLUSHO); tp->t_column = tp->t_rocol; cp = tp->t_rawq.c_cf; if (cp) tabc = *cp; /* XXX FIX NEXTC */ for (; cp; cp = nextc(&tp->t_rawq, cp, &tabc)) ttyecho(tabc, tp); CLR(tp->t_lflag, FLUSHO); CLR(tp->t_state, TS_CNTTB); splx(s); /* savecol will now be length of the tab. */ savecol -= tp->t_column; tp->t_column += savecol; if (savecol > 8) savecol = 8; /* overflow screw */ while (--savecol >= 0) (void)ttyoutput('\b', tp); break; default: /* XXX */ #define PANICSTR "ttyrub: would panic c = %d, val = %d\n" (void)printf(PANICSTR, c, CCLASS(c)); #ifdef notdef panic(PANICSTR, c, CCLASS(c)); #endif } } } else if (ISSET(tp->t_lflag, ECHOPRT)) { if (!ISSET(tp->t_state, TS_ERASE)) { SET(tp->t_state, TS_ERASE); (void)ttyoutput('\\', tp); } ttyecho(c, tp); } else { ttyecho(tp->t_cc[VERASE], tp); /* * This code may be executed not only when an ERASE key * is pressed, but also when ^U (KILL) or ^W (WERASE) are. * So, I didn't think it was worthwhile to pass the extra * information (which would need an extra parameter, * changing every call) needed to distinguish the ERASE2 * case from the ERASE. */ } --tp->t_rocount; } /* * Back over cnt characters, erasing them. */ static void ttyrubo(tp, cnt) register struct tty *tp; int cnt; { while (cnt-- > 0) { (void)ttyoutput('\b', tp); (void)ttyoutput(' ', tp); (void)ttyoutput('\b', tp); } } /* * ttyretype -- * Reprint the rawq line. Note, it is assumed that c_cc has already * been checked. */ static void ttyretype(tp) register struct tty *tp; { register char *cp; int s, c; /* Echo the reprint character. */ if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE) ttyecho(tp->t_cc[VREPRINT], tp); (void)ttyoutput('\n', tp); /* * XXX * FIX: NEXTC IS BROKEN - DOESN'T CHECK QUOTE * BIT OF FIRST CHAR. */ s = spltty(); for (cp = tp->t_canq.c_cf, c = (cp != NULL ? *cp : 0); cp != NULL; cp = nextc(&tp->t_canq, cp, &c)) ttyecho(c, tp); for (cp = tp->t_rawq.c_cf, c = (cp != NULL ? *cp : 0); cp != NULL; cp = nextc(&tp->t_rawq, cp, &c)) ttyecho(c, tp); CLR(tp->t_state, TS_ERASE); splx(s); tp->t_rocount = tp->t_rawq.c_cc; tp->t_rocol = 0; } /* * Echo a typed character to the terminal. */ static void ttyecho(c, tp) register int c; register struct tty *tp; { if (!ISSET(tp->t_state, TS_CNTTB)) CLR(tp->t_lflag, FLUSHO); if ((!ISSET(tp->t_lflag, ECHO) && (c != '\n' || !ISSET(tp->t_lflag, ECHONL))) || ISSET(tp->t_lflag, EXTPROC)) return; if (ISSET(tp->t_lflag, ECHOCTL) && ((ISSET(c, TTY_CHARMASK) <= 037 && c != '\t' && c != '\n') || ISSET(c, TTY_CHARMASK) == 0177)) { (void)ttyoutput('^', tp); CLR(c, ~TTY_CHARMASK); if (c == 0177) c = '?'; else c += 'A' - 1; } (void)ttyoutput(c, tp); } /* * Wake up any readers on a tty. */ void ttwakeup(tp) register struct tty *tp; { if (SEL_WAITING(&tp->t_rsel)) selwakeup(&tp->t_rsel); if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL) pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL)); wakeup(TSA_HUP_OR_INPUT(tp)); KNOTE(&tp->t_rsel.si_note, 0); } /* * Wake up any writers on a tty. */ void ttwwakeup(tp) register struct tty *tp; { if (SEL_WAITING(&tp->t_wsel) && tp->t_outq.c_cc <= tp->t_olowat) selwakeup(&tp->t_wsel); if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL) pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL)); if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) == TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) { CLR(tp->t_state, TS_SO_OCOMPLETE); wakeup(TSA_OCOMPLETE(tp)); } if (ISSET(tp->t_state, TS_SO_OLOWAT) && tp->t_outq.c_cc <= tp->t_olowat) { CLR(tp->t_state, TS_SO_OLOWAT); wakeup(TSA_OLOWAT(tp)); } KNOTE(&tp->t_wsel.si_note, 0); } /* * Look up a code for a specified speed in a conversion table; * used by drivers to map software speed values to hardware parameters. */ int ttspeedtab(speed, table) int speed; register struct speedtab *table; { for ( ; table->sp_speed != -1; table++) if (table->sp_speed == speed) return (table->sp_code); return (-1); } /* * Set input and output watermarks and buffer sizes. For input, the * high watermark is about one second's worth of input above empty, the * low watermark is slightly below high water, and the buffer size is a * driver-dependent amount above high water. For output, the watermarks * are near the ends of the buffer, with about 1 second's worth of input * between them. All this only applies to the standard line discipline. */ void ttsetwater(tp) struct tty *tp; { register int cps, ttmaxhiwat, x; /* Input. */ clist_alloc_cblocks(&tp->t_canq, TTYHOG, 512); switch (tp->t_ispeedwat) { case (speed_t)-1: cps = tp->t_ispeed / 10; break; case 0: /* * This case is for old drivers that don't know about * t_ispeedwat. Arrange for them to get the old buffer * sizes and watermarks. */ cps = TTYHOG - 2 * 256; tp->t_ififosize = 2 * 256; break; default: cps = tp->t_ispeedwat / 10; break; } tp->t_ihiwat = cps; tp->t_ilowat = 7 * cps / 8; x = cps + tp->t_ififosize; clist_alloc_cblocks(&tp->t_rawq, x, x); /* Output. */ switch (tp->t_ospeedwat) { case (speed_t)-1: cps = tp->t_ospeed / 10; ttmaxhiwat = 2 * TTMAXHIWAT; break; case 0: cps = tp->t_ospeed / 10; ttmaxhiwat = TTMAXHIWAT; break; default: cps = tp->t_ospeedwat / 10; ttmaxhiwat = 8 * TTMAXHIWAT; break; } #define CLAMP(x, h, l) ((x) > h ? h : ((x) < l) ? l : (x)) tp->t_olowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT); x += cps; x = CLAMP(x, ttmaxhiwat, TTMINHIWAT); /* XXX clamps are too magic */ tp->t_ohiwat = roundup(x, CBSIZE); /* XXX for compat */ x = imax(tp->t_ohiwat, TTMAXHIWAT); /* XXX for compat/safety */ x += OBUFSIZ + 100; clist_alloc_cblocks(&tp->t_outq, x, x); #undef CLAMP } /* * Report on state of foreground process group. */ void ttyinfo(tp) register struct tty *tp; { register struct proc *p, *pick; struct timeval utime, stime; const char *stmp; long ltmp; int tmp; struct thread *td; if (ttycheckoutq(tp,0) == 0) return; /* Print load average. */ tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT; ttyprintf(tp, "load: %d.%02d ", tmp / 100, tmp % 100); if (tp->t_session == NULL) ttyprintf(tp, "not a controlling terminal\n"); else if (tp->t_pgrp == NULL) ttyprintf(tp, "no foreground process group\n"); else { PGRP_LOCK(tp->t_pgrp); if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == 0) { PGRP_UNLOCK(tp->t_pgrp); ttyprintf(tp, "empty foreground process group\n"); } else { mtx_lock_spin(&sched_lock); /* Pick interesting process. */ for (pick = NULL; p != 0; p = LIST_NEXT(p, p_pglist)) if (proc_compare(pick, p)) pick = p; PGRP_UNLOCK(tp->t_pgrp); td = FIRST_THREAD_IN_PROC(pick); stmp = pick->p_stat == SRUN ? "running" : /* XXXKSE */ td->td_wmesg ? td->td_wmesg : "iowait"; calcru(pick, &utime, &stime, NULL); ltmp = pick->p_stat == SIDL || pick->p_stat == SWAIT || pick->p_stat == SZOMB ? 0 : pgtok(vmspace_resident_count(pick->p_vmspace)); mtx_unlock_spin(&sched_lock); ttyprintf(tp, " cmd: %s %d [%s] ", pick->p_comm, pick->p_pid, stmp); /* Print user time. */ ttyprintf(tp, "%ld.%02ldu ", utime.tv_sec, utime.tv_usec / 10000); /* Print system time. */ ttyprintf(tp, "%ld.%02lds ", (long)stime.tv_sec, stime.tv_usec / 10000); /* Print percentage cpu, resident set size. */ ttyprintf(tp, "%d%% %ldk\n", tmp / 100, ltmp); } } tp->t_rocount = 0; /* so pending input will be retyped if BS */ } /* * Returns 1 if p2 is "better" than p1 * * The algorithm for picking the "interesting" process is thus: * * 1) Only foreground processes are eligible - implied. * 2) Runnable processes are favored over anything else. The runner * with the highest cpu utilization is picked (p_estcpu). Ties are * broken by picking the highest pid. * 3) The sleeper with the shortest sleep time is next. With ties, * we pick out just "short-term" sleepers (P_SINTR == 0). * 4) Further ties are broken by picking the highest pid. */ #define ISRUN(p) (((p)->p_stat == SRUN) || ((p)->p_stat == SIDL)) #define TESTAB(a, b) ((a)<<1 | (b)) #define ONLYA 2 #define ONLYB 1 #define BOTH 3 static int proc_compare(p1, p2) register struct proc *p1, *p2; { int esta, estb; struct ksegrp *kg; mtx_assert(&sched_lock, MA_OWNED); if (p1 == NULL) return (1); /* * see if at least one of them is runnable */ switch (TESTAB(ISRUN(p1), ISRUN(p2))) { case ONLYA: return (0); case ONLYB: return (1); case BOTH: /* * tie - favor one with highest recent cpu utilization */ esta = estb = 0; FOREACH_KSEGRP_IN_PROC(p1,kg) { esta += kg->kg_estcpu; } FOREACH_KSEGRP_IN_PROC(p2,kg) { estb += kg->kg_estcpu; } if (estb > esta) return (1); if (esta > estb) return (0); return (p2->p_pid > p1->p_pid); /* tie - return highest pid */ } /* * weed out zombies */ switch (TESTAB(p1->p_stat == SZOMB, p2->p_stat == SZOMB)) { case ONLYA: return (1); case ONLYB: return (0); case BOTH: return (p2->p_pid > p1->p_pid); /* tie - return highest pid */ } #if 0 /* XXXKSE */ /* * pick the one with the smallest sleep time */ if (p2->p_slptime > p1->p_slptime) return (0); if (p1->p_slptime > p2->p_slptime) return (1); /* * favor one sleeping in a non-interruptible sleep */ if (p1->p_sflag & PS_SINTR && (p2->p_sflag & PS_SINTR) == 0) return (1); if (p2->p_sflag & PS_SINTR && (p1->p_sflag & PS_SINTR) == 0) return (0); #endif return (p2->p_pid > p1->p_pid); /* tie - return highest pid */ } /* * Output char to tty; console putchar style. */ int tputchar(c, tp) int c; struct tty *tp; { register int s; s = spltty(); if (!ISSET(tp->t_state, TS_CONNECTED)) { splx(s); return (-1); } if (c == '\n') (void)ttyoutput('\r', tp); (void)ttyoutput(c, tp); ttstart(tp); splx(s); return (0); } /* * Sleep on chan, returning ERESTART if tty changed while we napped and * returning any errors (e.g. EINTR/EWOULDBLOCK) reported by tsleep. If * the tty is revoked, restarting a pending call will redo validation done * at the start of the call. */ int ttysleep(tp, chan, pri, wmesg, timo) struct tty *tp; void *chan; int pri, timo; char *wmesg; { int error; int gen; gen = tp->t_gen; error = tsleep(chan, pri, wmesg, timo); if (error) return (error); return (tp->t_gen == gen ? 0 : ERESTART); } /* * Allocate a tty struct. Clists in the struct will be allocated by * ttyopen(). */ struct tty * ttymalloc(tp) struct tty *tp; { if (tp) return(tp); tp = malloc(sizeof *tp, M_TTYS, M_WAITOK | M_ZERO); ttyregister(tp); return (tp); } #if 0 /* XXX not yet usable: session leader holds a ref (see kern_exit.c). */ /* * Free a tty struct. Clists in the struct should have been freed by * ttyclose(). */ void ttyfree(tp) struct tty *tp; { free(tp, M_TTYS); } #endif /* 0 */ void ttyregister(tp) struct tty *tp; { tp->t_timeout = -1; SLIST_INSERT_HEAD(&tty_list, tp, t_list); } static int sysctl_kern_ttys(SYSCTL_HANDLER_ARGS) { int error; struct tty *tp, t; SLIST_FOREACH(tp, &tty_list, t_list) { t = *tp; if (t.t_dev) t.ttyu.t_udev = dev2udev(t.t_dev); error = SYSCTL_OUT(req, (caddr_t)&t, sizeof(t)); if (error) return (error); } return (0); } SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0, sysctl_kern_ttys, "S,tty", "All struct ttys"); SYSCTL_LONG(_kern, OID_AUTO, tty_nin, CTLFLAG_RD, &tk_nin, 0, "Total TTY in characters"); SYSCTL_LONG(_kern, OID_AUTO, tty_nout, CTLFLAG_RD, &tk_nout, 0, "Total TTY out characters"); void nottystop(tp, rw) struct tty *tp; int rw; { return; } int ttyread(dev, uio, flag) dev_t dev; struct uio *uio; int flag; { struct tty *tp; tp = dev->si_tty; if (tp == NULL) return (ENODEV); return ((*linesw[tp->t_line].l_read)(tp, uio, flag)); } int ttywrite(dev, uio, flag) dev_t dev; struct uio *uio; int flag; { struct tty *tp; tp = dev->si_tty; if (tp == NULL) return (ENODEV); return ((*linesw[tp->t_line].l_write)(tp, uio, flag)); }