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NetBSD/sys/kern/tty.c

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/* $NetBSD: tty.c,v 1.198 2007/09/25 14:04:07 ad Exp $ */
/*-
* 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. 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 8.13 (Berkeley) 1/9/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tty.c,v 1.198 2007/09/25 14:04:07 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#define TTYDEFCHARS
#include <sys/tty.h>
#undef TTYDEFCHARS
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/dkstat.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/poll.h>
#include <sys/kprintf.h>
#include <sys/namei.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <machine/stdarg.h>
static int ttnread(struct tty *);
static void ttyblock(struct tty *);
static void ttyecho(int, struct tty *);
static void ttyrubo(struct tty *, int);
static void ttyprintf_nolock(struct tty *, const char *fmt, ...)
__attribute__((__format__(__printf__,2,3)));
static int proc_compare(struct proc *, struct proc *);
/* Symbolic sleep message strings. */
const char ttclos[] = "ttycls";
const char ttopen[] = "ttyopn";
const char ttybg[] = "ttybg";
const char ttyin[] = "ttyin";
const char ttyout[] = "ttyout";
/*
* Used to determine whether we still have a connection. This is true in
* one of 3 cases:
* 1) We have carrier.
* 2) It's a locally attached terminal, and we are therefore ignoring carrier.
* 3) We're using a flow control mechanism that overloads the carrier signal.
*/
#define CONNECTED(tp) (ISSET(tp->t_state, TS_CARR_ON) || \
ISSET(tp->t_cflag, CLOCAL | MDMBUF))
/*
* 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
unsigned 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
kmutex_t ttylist_lock;
struct ttylist_head ttylist = TAILQ_HEAD_INITIALIZER(ttylist);
int tty_count;
POOL_INIT(tty_pool, sizeof(struct tty), 0, 0, 0, "ttypl",
&pool_allocator_nointr, IPL_NONE);
uint64_t tk_cancc;
uint64_t tk_nin;
uint64_t tk_nout;
uint64_t tk_rawcc;
SYSCTL_SETUP(sysctl_kern_tkstat_setup, "sysctl kern.tkstat subtree setup")
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "kern", NULL,
NULL, 0, NULL, 0,
CTL_KERN, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "tkstat",
SYSCTL_DESCR("Number of characters sent and and "
"received on ttys"),
NULL, 0, NULL, 0,
CTL_KERN, KERN_TKSTAT, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "nin",
SYSCTL_DESCR("Total number of tty input characters"),
NULL, 0, &tk_nin, 0,
CTL_KERN, KERN_TKSTAT, KERN_TKSTAT_NIN, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "nout",
SYSCTL_DESCR("Total number of tty output characters"),
NULL, 0, &tk_nout, 0,
CTL_KERN, KERN_TKSTAT, KERN_TKSTAT_NOUT, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "cancc",
SYSCTL_DESCR("Number of canonical tty input characters"),
NULL, 0, &tk_cancc, 0,
CTL_KERN, KERN_TKSTAT, KERN_TKSTAT_CANCC, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_QUAD, "rawcc",
SYSCTL_DESCR("Number of raw tty input characters"),
NULL, 0, &tk_rawcc, 0,
CTL_KERN, KERN_TKSTAT, KERN_TKSTAT_RAWCC, CTL_EOL);
}
int
ttyopen(struct tty *tp, int dialout, int nonblock)
{
int s, error;
error = 0;
s = spltty();
TTY_LOCK(tp);
if (dialout) {
/*
* If the device is already open for non-dialout, fail.
* Otherwise, set TS_DIALOUT to block any pending non-dialout
* opens.
*/
if (ISSET(tp->t_state, TS_ISOPEN) &&
!ISSET(tp->t_state, TS_DIALOUT)) {
error = EBUSY;
goto out;
}
SET(tp->t_state, TS_DIALOUT);
} else {
if (!nonblock) {
/*
* Wait for carrier. Also wait for any dialout
* processes to close the tty first.
*/
while (ISSET(tp->t_state, TS_DIALOUT) ||
!CONNECTED(tp)) {
tp->t_wopen++;
error = ttysleep(tp, &tp->t_rawq,
TTIPRI | PCATCH, ttopen, 0);
tp->t_wopen--;
if (error)
goto out;
}
} else {
/*
* Don't allow a non-blocking non-dialout open if the
* device is already open for dialout.
*/
if (ISSET(tp->t_state, TS_DIALOUT)) {
error = EBUSY;
goto out;
}
}
}
out:
TTY_UNLOCK(tp);
splx(s);
return (error);
}
/*
* Initial open of tty, or (re)entry to standard tty line discipline.
*/
int
ttylopen(dev_t device, struct tty *tp)
{
int s;
s = spltty();
TTY_LOCK(tp);
tp->t_dev = device;
if (!ISSET(tp->t_state, TS_ISOPEN)) {
SET(tp->t_state, TS_ISOPEN);
memset(&tp->t_winsize, 0, sizeof(tp->t_winsize));
#ifdef COMPAT_OLDTTY
tp->t_flags = 0;
#endif
}
TTY_UNLOCK(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.
*/
int
ttyclose(struct tty *tp)
{
extern struct tty *constty; /* Temporary virtual console. */
int s;
s = spltty();
TTY_LOCK(tp);
if (constty == tp)
constty = NULL;
ttyflush(tp, FREAD | FWRITE);
tp->t_gen++;
tp->t_pgrp = NULL;
tp->t_state = 0;
TTY_UNLOCK(tp);
splx(s);
mutex_enter(&proclist_lock);
s = spltty();
TTY_LOCK(tp);
if (tp->t_session != NULL) {
SESSRELE(tp->t_session);
tp->t_session = NULL;
}
TTY_UNLOCK(tp);
splx(s);
mutex_exit(&proclist_lock);
return (0);
}
#define FLUSHQ(q) { \
if ((q)->c_cc) \
ndflush(q, (q)->c_cc); \
}
/*
* This macro is used in canonical mode input processing, where a read
* request shall not return unless a 'line delimiter' ('\n') or 'break'
* (EOF, EOL, EOL2) character (or a signal) has been received. As EOL2
* is an extension to the POSIX.1 defined set of special characters,
* recognize it only if IEXTEN is set in the set of local flags.
*/
#define TTBREAKC(c, lflg) \
((c) == '\n' || (((c) == cc[VEOF] || (c) == cc[VEOL] || \
((c) == cc[VEOL2] && ISSET(lflg, IEXTEN))) && (c) != _POSIX_VDISABLE))
/*
* ttyinput() helper.
* Call at spltty() and with the tty slock held.
*/
static int
ttyinput_wlock(int c, struct tty *tp)
{
const struct cdevsw *cdev;
int iflag, lflag, i, error;
u_char *cc;
/*
* 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;
cc = tp->t_cc;
/*
* Handle exceptional conditions (break, parity, framing).
*/
iflag = tp->t_iflag;
if ((error = (ISSET(c, TTY_ERRORMASK))) != 0) {
CLR(c, TTY_ERRORMASK);
if (ISSET(error, TTY_FE) && c == 0) { /* Break. */
if (ISSET(iflag, IGNBRK))
return (0);
else if (ISSET(iflag, BRKINT)) {
ttyflush(tp, FREAD | FWRITE);
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp, SIGINT, 1);
mutex_exit(&proclist_mutex);
return (0);
} else if (ISSET(iflag, PARMRK))
goto parmrk;
} else if ((ISSET(error, TTY_PE) && ISSET(iflag, INPCK)) ||
ISSET(error, TTY_FE)) {
if (ISSET(iflag, IGNPAR))
return (0);
else if (ISSET(iflag, PARMRK)) {
parmrk: (void)putc(0377 | TTY_QUOTE, &tp->t_rawq);
(void)putc(0 | TTY_QUOTE, &tp->t_rawq);
(void)putc(c | TTY_QUOTE, &tp->t_rawq);
return (0);
} else
c = 0;
}
} else if (c == 0377 &&
ISSET(iflag, ISTRIP|IGNPAR|INPCK|PARMRK) == (INPCK|PARMRK)) {
/* "Escape" a valid character of '\377'. */
(void)putc(0377 | TTY_QUOTE, &tp->t_rawq);
(void)putc(0377 | TTY_QUOTE, &tp->t_rawq);
goto endcase;
}
/*
* In tandem mode, check high water mark.
*/
if (ISSET(iflag, IXOFF) || ISSET(tp->t_cflag, CHWFLOW))
ttyblock(tp);
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);
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp,
CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
mutex_exit(&proclist_mutex);
goto endcase;
}
if (CCEQ(cc[VSUSP], c)) {
if (!ISSET(lflag, NOFLSH))
ttyflush(tp, FREAD);
ttyecho(c, tp);
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp, SIGTSTP, 1);
mutex_exit(&proclist_mutex);
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);
cdev = cdevsw_lookup(tp->t_dev);
if (cdev != NULL)
(*cdev->d_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))
goto endcase;
else if (ISSET(iflag, ICRNL))
c = '\n';
} else if (c == '\n' && ISSET(iflag, INLCR))
c = '\r';
}
if (!ISSET(lflag, EXTPROC) && ISSET(lflag, ICANON)) {
/*
* From here on down canonical mode character
* processing takes place.
*/
/*
* erase (^H / ^?)
*/
if (CCEQ(cc[VERASE], 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;
}
/*
* Extensions to the POSIX.1 GTI set of functions.
*/
if (ISSET(lflag, IEXTEN)) {
/*
* word erase (^W)
*/
if (CCEQ(cc[VWERASE], c)) {
int alt = ISSET(lflag, ALTWERASE);
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' &&
(alt == 0 || ISALPHA(c) == ctype));
(void)putc(c, &tp->t_rawq);
goto endcase;
}
/*
* reprint line (^R)
*/
if (CCEQ(cc[VREPRINT], c)) {
ttyretype(tp);
goto endcase;
}
/*
* ^T - kernel info and generate SIGINFO
*/
if (CCEQ(cc[VSTATUS], c)) {
if (!ISSET(lflag, NOKERNINFO))
ttyinfo(tp, 1);
if (ISSET(lflag, ISIG)) {
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp, SIGINFO, 1);
mutex_exit(&proclist_mutex);
}
goto endcase;
}
}
}
/*
* Check for input buffer overflow
*/
if (tp->t_rawq.c_cc + tp->t_canq.c_cc >= TTYHOG) {
if (ISSET(iflag, IMAXBEL)) {
if (tp->t_outq.c_cc < tp->t_hiwat)
(void)ttyoutput(CTRL('g'), tp);
} else
ttyflush(tp, FREAD | FWRITE);
goto endcase;
}
/*
* 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 = min(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));
}
/*
* Process input of a single character received on a tty.
* Must be called at spltty().
*
* XXX - this is a hack, all drivers must changed to acquire the
* lock before calling linesw->l_rint()
*/
int
ttyinput(int c, struct tty *tp)
{
int error;
int s;
/*
* Unless the receiver is enabled, drop incoming data.
*/
if (!ISSET(tp->t_cflag, CREAD))
return (0);
s = spltty();
TTY_LOCK(tp);
error = ttyinput_wlock(c, tp);
TTY_UNLOCK(tp);
splx(s);
return (error);
}
/*
* 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.
* Call with tty slock held.
*/
int
ttyoutput(int c, struct tty *tp)
{
long oflag;
int col, notout, s;
oflag = tp->t_oflag;
if (!ISSET(oflag, OPOST)) {
tk_nout++;
tp->t_outcc++;
if (!ISSET(tp->t_lflag, FLUSHO) && putc(c, &tp->t_outq))
return (c);
return (-1);
}
/*
* Do tab expansion if OXTABS is set. Special case if we do 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)) {
notout = 0;
} else {
s = spltty(); /* Don't interrupt tabs. */
notout = b_to_q(" ", c, &tp->t_outq);
c -= notout;
tk_nout += c;
tp->t_outcc += c;
splx(s);
}
tp->t_column += c;
return (notout ? '\t' : -1);
}
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(struct tty *tp, u_long cmd, void *data, int flag, struct lwp *l)
{
extern struct tty *constty; /* Temporary virtual console. */
struct proc *p = l ? l->l_proc : NULL;
struct linesw *lp;
int s, error;
struct nameidata nd;
/* If the ioctl involves modification, hang if in the background. */
switch (cmd) {
case TIOCFLUSH:
case TIOCDRAIN:
case TIOCSBRK:
case TIOCCBRK:
case TIOCSTART:
case TIOCSETA:
case TIOCSETD:
case TIOCSLINED:
case TIOCSETAF:
case TIOCSETAW:
#ifdef notdef
case TIOCSPGRP:
case FIOSETOWN:
#endif
case TIOCSTAT:
case TIOCSTI:
case TIOCSWINSZ:
#ifdef COMPAT_OLDTTY
case TIOCLBIC:
case TIOCLBIS:
case TIOCLSET:
case TIOCSETC:
case OTIOCSETD:
case TIOCSETN:
case TIOCSETP:
case TIOCSLTC:
#endif
/* XXXSMP */
while (isbackground(curproc, tp) &&
p->p_pgrp->pg_jobc && (p->p_sflag & PS_PPWAIT) == 0 &&
!sigismasked(l, SIGTTOU)) {
mutex_enter(&proclist_mutex);
pgsignal(p->p_pgrp, SIGTTOU, 1);
mutex_exit(&proclist_mutex);
s = spltty();
TTY_LOCK(tp);
error = ttysleep(tp, &lbolt,
TTOPRI | PCATCH | PNORELOCK, ttybg, 0);
splx(s);
if (error) {
return (error);
}
}
break;
}
switch (cmd) { /* Process the ioctl. */
case FIOASYNC: /* set/clear async i/o */
s = spltty();
TTY_LOCK(tp);
if (*(int *)data)
SET(tp->t_state, TS_ASYNC);
else
CLR(tp->t_state, TS_ASYNC);
TTY_UNLOCK(tp);
splx(s);
break;
case FIONBIO: /* set/clear non-blocking i/o */
break; /* XXX: delete. */
case FIONREAD: /* get # bytes to read */
s = spltty();
TTY_LOCK(tp);
*(int *)data = ttnread(tp);
TTY_UNLOCK(tp);
splx(s);
break;
case FIONWRITE: /* get # bytes to written & unsent */
s = spltty();
TTY_LOCK(tp);
*(int *)data = tp->t_outq.c_cc;
TTY_UNLOCK(tp);
splx(s);
break;
case FIONSPACE: /* get # bytes to written & unsent */
s = spltty();
TTY_LOCK(tp);
*(int *)data = tp->t_outq.c_cn - tp->t_outq.c_cc;
TTY_UNLOCK(tp);
splx(s);
break;
case TIOCEXCL: /* set exclusive use of tty */
s = spltty();
TTY_LOCK(tp);
SET(tp->t_state, TS_XCLUDE);
splx(s);
TTY_UNLOCK(tp);
break;
case TIOCFLUSH: { /* flush buffers */
int flags = *(int *)data;
if (flags == 0)
flags = FREAD | FWRITE;
else
flags &= FREAD | FWRITE;
s = spltty();
TTY_LOCK(tp);
ttyflush(tp, flags);
TTY_UNLOCK(tp);
splx(s);
break;
}
case TIOCCONS: /* become virtual console */
if (*(int *)data) {
if (constty && constty != tp &&
ISSET(constty->t_state, TS_CARR_ON | TS_ISOPEN) ==
(TS_CARR_ON | TS_ISOPEN))
return EBUSY;
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
"/dev/console", l);
if ((error = namei(&nd)) != 0)
return error;
error = VOP_ACCESS(nd.ni_vp, VREAD, l->l_cred, l);
vput(nd.ni_vp);
if (error)
return error;
constty = tp;
} else if (tp == constty)
constty = NULL;
break;
case TIOCDRAIN: /* wait till output drained */
if ((error = ttywait(tp)) != 0)
return (error);
break;
case TIOCGETA: { /* get termios struct */
struct termios *t = (struct termios *)data;
memcpy(t, &tp->t_termios, sizeof(struct termios));
break;
}
case TIOCGETD: /* get line discipline (old) */
*(int *)data = tp->t_linesw->l_no;
break;
case TIOCGLINED: /* get line discipline (new) */
(void)strncpy((char *)data, tp->t_linesw->l_name,
TTLINEDNAMELEN - 1);
break;
case TIOCGWINSZ: /* get window size */
*(struct winsize *)data = tp->t_winsize;
break;
case FIOGETOWN:
if (tp->t_session != NULL && !isctty(p, tp))
return (ENOTTY);
*(int *)data = tp->t_pgrp ? -tp->t_pgrp->pg_id : 0;
break;
case TIOCGPGRP: /* get pgrp of tty */
if (!isctty(p, tp))
return (ENOTTY);
*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PGID;
break;
case TIOCGSID: /* get sid of tty */
if (!isctty(p, tp))
return (ENOTTY);
*(int *)data = tp->t_session->s_sid;
break;
#ifdef TIOCHPCL
case TIOCHPCL: /* hang up on last close */
s = spltty();
TTY_LOCK(tp);
SET(tp->t_cflag, HUPCL);
TTY_UNLOCK(tp);
splx(s);
break;
#endif
case TIOCNXCL: /* reset exclusive use of tty */
s = spltty();
TTY_LOCK(tp);
CLR(tp->t_state, TS_XCLUDE);
TTY_UNLOCK(tp);
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 */
struct termios *t = (struct termios *)data;
if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
if ((error = ttywait(tp)) != 0)
return (error);
if (cmd == TIOCSETAF) {
s = spltty();
TTY_LOCK(tp);
ttyflush(tp, FREAD);
TTY_UNLOCK(tp);
splx(s);
}
}
s = spltty();
/*
* XXXSMP - some drivers call back on us from t_param(), so
* don't take the tty spin lock here.
* require t_param() to unlock upon callback?
*/
/* wanted here: TTY_LOCK(tp); */
if (!ISSET(t->c_cflag, CIGNORE)) {
/*
* Set device hardware.
*/
if (tp->t_param && (error = (*tp->t_param)(tp, t))) {
/* wanted here: TTY_UNLOCK(tp); */
splx(s);
return (error);
} else {
tp->t_cflag = t->c_cflag;
tp->t_ispeed = t->c_ispeed;
tp->t_ospeed = t->c_ospeed;
if (t->c_ospeed == 0 && tp->t_session &&
tp->t_session->s_leader) {
mutex_enter(&proclist_mutex);
psignal(tp->t_session->s_leader,
SIGHUP);
mutex_exit(&proclist_mutex);
}
}
ttsetwater(tp);
}
/* delayed lock acquiring */TTY_LOCK(tp);
if (cmd != TIOCSETAF) {
if (ISSET(t->c_lflag, ICANON) !=
ISSET(tp->t_lflag, ICANON)) {
if (ISSET(t->c_lflag, ICANON)) {
SET(tp->t_lflag, PENDIN);
ttwakeup(tp);
} else {
struct clist tq;
catq(&tp->t_rawq, &tp->t_canq);
tq = tp->t_rawq;
tp->t_rawq = tp->t_canq;
tp->t_canq = tq;
CLR(tp->t_lflag, PENDIN);
}
}
}
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);
memcpy(tp->t_cc, t->c_cc, sizeof(t->c_cc));
TTY_UNLOCK(tp);
splx(s);
break;
}
case TIOCSETD: /* set line discipline (old) */
lp = ttyldisc_lookup_bynum(*(int *)data);
goto setldisc;
case TIOCSLINED: { /* set line discipline (new) */
char *name = (char *)data;
dev_t device;
/* Null terminate to prevent buffer overflow */
name[TTLINEDNAMELEN - 1] = '\0';
lp = ttyldisc_lookup(name);
setldisc:
if (lp == NULL)
return (ENXIO);
if (lp != tp->t_linesw) {
device = tp->t_dev;
s = spltty();
(*tp->t_linesw->l_close)(tp, flag);
error = (*lp->l_open)(device, tp);
if (error) {
(void)(*tp->t_linesw->l_open)(device, tp);
splx(s);
ttyldisc_release(lp);
return (error);
}
ttyldisc_release(tp->t_linesw);
tp->t_linesw = lp;
splx(s);
} else {
/* Drop extra reference. */
ttyldisc_release(lp);
}
break;
}
case TIOCSTART: /* start output, like ^Q */
s = spltty();
TTY_LOCK(tp);
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);
}
TTY_UNLOCK(tp);
splx(s);
break;
case TIOCSTI: /* simulate terminal input */
if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
NULL) != 0) {
if (!ISSET(flag, FREAD))
return (EPERM);
if (!isctty(p, tp))
return (EACCES);
}
(*tp->t_linesw->l_rint)(*(u_char *)data, tp);
break;
case TIOCSTOP: /* stop output, like ^S */
{
const struct cdevsw *cdev;
s = spltty();
TTY_LOCK(tp);
if (!ISSET(tp->t_state, TS_TTSTOP)) {
SET(tp->t_state, TS_TTSTOP);
cdev = cdevsw_lookup(tp->t_dev);
if (cdev != NULL)
(*cdev->d_stop)(tp, 0);
}
TTY_UNLOCK(tp);
splx(s);
break;
}
case TIOCSCTTY: /* become controlling tty */
mutex_enter(&proclist_lock);
/* Session ctty vnode pointer set in vnode layer. */
if (!SESS_LEADER(p) ||
((p->p_session->s_ttyvp || tp->t_session) &&
(tp->t_session != p->p_session))) {
mutex_exit(&proclist_lock);
return (EPERM);
}
/*
* `p_session' acquires a reference.
* But note that if `t_session' is set at this point,
* it must equal `p_session', in which case the session
* already has the correct reference count.
*/
if (tp->t_session == NULL)
SESSHOLD(p->p_session);
tp->t_session = p->p_session;
tp->t_pgrp = p->p_pgrp;
p->p_session->s_ttyp = tp;
p->p_lflag |= PL_CONTROLT;
mutex_exit(&proclist_lock);
break;
case FIOSETOWN: { /* set pgrp of tty */
pid_t pgid = *(int *)data;
struct pgrp *pgrp;
if (tp->t_session != NULL && !isctty(p, tp))
return (ENOTTY);
mutex_enter(&proclist_lock);
if (pgid < 0) {
pgrp = pg_find(-pgid, PFIND_LOCKED | PFIND_UNLOCK_FAIL);
if (pgrp == NULL)
return (EINVAL);
} else {
struct proc *p1;
p1 = p_find(pgid, PFIND_LOCKED | PFIND_UNLOCK_FAIL);
if (!p1)
return (ESRCH);
pgrp = p1->p_pgrp;
}
if (pgrp->pg_session != p->p_session) {
mutex_exit(&proclist_lock);
return (EPERM);
}
tp->t_pgrp = pgrp;
mutex_exit(&proclist_lock);
break;
}
case TIOCSPGRP: { /* set pgrp of tty */
struct pgrp *pgrp;
if (!isctty(p, tp))
return (ENOTTY);
mutex_enter(&proclist_lock);
pgrp = pg_find(*(int *)data, PFIND_LOCKED | PFIND_UNLOCK_FAIL);
if (pgrp == NULL)
return (EINVAL);
if (pgrp->pg_session != p->p_session) {
mutex_exit(&proclist_lock);
return (EPERM);
}
tp->t_pgrp = pgrp;
mutex_exit(&proclist_lock);
break;
}
case TIOCSTAT: /* get load avg stats */
s = spltty();
TTY_LOCK(tp);
ttyinfo(tp, 0);
TTY_UNLOCK(tp);
splx(s);
break;
case TIOCSWINSZ: /* set window size */
if (memcmp((void *)&tp->t_winsize, data,
sizeof(struct winsize))) {
tp->t_winsize = *(struct winsize *)data;
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp, SIGWINCH, 1);
mutex_exit(&proclist_mutex);
}
break;
default:
#ifdef COMPAT_OLDTTY
return (ttcompat(tp, cmd, data, flag, l));
#else
return (EPASSTHROUGH);
#endif
}
return (0);
}
int
ttpoll(struct tty *tp, int events, struct lwp *l)
{
int revents, s;
revents = 0;
s = spltty();
TTY_LOCK(tp);
if (events & (POLLIN | POLLRDNORM))
if (ttnread(tp) > 0)
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (tp->t_outq.c_cc <= tp->t_lowat)
revents |= events & (POLLOUT | POLLWRNORM);
if (events & POLLHUP)
if (!CONNECTED(tp))
revents |= POLLHUP;
if (revents == 0) {
if (events & (POLLIN | POLLHUP | POLLRDNORM))
selrecord(l, &tp->t_rsel);
if (events & (POLLOUT | POLLWRNORM))
selrecord(l, &tp->t_wsel);
}
TTY_UNLOCK(tp);
splx(s);
return (revents);
}
static void
filt_ttyrdetach(struct knote *kn)
{
struct tty *tp;
int s;
tp = kn->kn_hook;
s = spltty();
TTY_LOCK(tp);
SLIST_REMOVE(&tp->t_rsel.sel_klist, kn, knote, kn_selnext);
TTY_UNLOCK(tp);
splx(s);
}
static int
filt_ttyread(struct knote *kn, long hint)
{
struct tty *tp;
int s;
tp = kn->kn_hook;
s = spltty();
if ((hint & NOTE_SUBMIT) == 0)
TTY_LOCK(tp);
kn->kn_data = ttnread(tp);
if ((hint & NOTE_SUBMIT) == 0)
TTY_UNLOCK(tp);
splx(s);
return (kn->kn_data > 0);
}
static void
filt_ttywdetach(struct knote *kn)
{
struct tty *tp;
int s;
tp = kn->kn_hook;
s = spltty();
TTY_LOCK(tp);
SLIST_REMOVE(&tp->t_wsel.sel_klist, kn, knote, kn_selnext);
TTY_UNLOCK(tp);
splx(s);
}
static int
filt_ttywrite(struct knote *kn, long hint)
{
struct tty *tp;
int canwrite, s;
tp = kn->kn_hook;
s = spltty();
if ((hint & NOTE_SUBMIT) == 0)
TTY_LOCK(tp);
kn->kn_data = tp->t_outq.c_cn - tp->t_outq.c_cc;
canwrite = (tp->t_outq.c_cc <= tp->t_lowat) && CONNECTED(tp);
if ((hint & NOTE_SUBMIT) == 0)
TTY_UNLOCK(tp);
splx(s);
return (canwrite);
}
static const struct filterops ttyread_filtops =
{ 1, NULL, filt_ttyrdetach, filt_ttyread };
static const struct filterops ttywrite_filtops =
{ 1, NULL, filt_ttywdetach, filt_ttywrite };
int
ttykqfilter(dev_t dev, struct knote *kn)
{
struct tty *tp;
struct klist *klist;
int s;
const struct cdevsw *cdev;
if (((cdev = cdevsw_lookup(dev)) == NULL) ||
(cdev->d_tty == NULL) ||
((tp = (*cdev->d_tty)(dev)) == NULL))
return (ENXIO);
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &tp->t_rsel.sel_klist;
kn->kn_fop = &ttyread_filtops;
break;
case EVFILT_WRITE:
klist = &tp->t_wsel.sel_klist;
kn->kn_fop = &ttywrite_filtops;
break;
default:
return EINVAL;
}
kn->kn_hook = tp;
s = spltty();
TTY_LOCK(tp);
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
TTY_UNLOCK(tp);
splx(s);
return (0);
}
/*
* Find the number of chars ready to be read from this tty.
* Call at spltty() and with the tty slock held.
*/
static int
ttnread(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])
nread = 0;
}
return (nread);
}
/*
* Wait for output to drain.
*/
int
ttywait(struct tty *tp)
{
int error, s;
error = 0;
s = spltty();
TTY_LOCK(tp);
while ((tp->t_outq.c_cc || ISSET(tp->t_state, TS_BUSY)) &&
CONNECTED(tp) && tp->t_oproc) {
(*tp->t_oproc)(tp);
SET(tp->t_state, TS_ASLEEP);
error = ttysleep(tp, &tp->t_outq, TTOPRI | PCATCH, ttyout, 0);
if (error)
break;
}
TTY_UNLOCK(tp);
splx(s);
return (error);
}
/*
* Flush if successfully wait.
*/
int
ttywflush(struct tty *tp)
{
int error;
int s;
if ((error = ttywait(tp)) == 0) {
s = spltty();
TTY_LOCK(tp);
ttyflush(tp, FREAD);
TTY_UNLOCK(tp);
splx(s);
}
return (error);
}
/*
* Flush tty read and/or write queues, notifying anyone waiting.
* Call at spltty() and with the tty slock held.
*/
void
ttyflush(struct tty *tp, int rw)
{
const struct cdevsw *cdev;
if (rw & FREAD) {
FLUSHQ(&tp->t_canq);
FLUSHQ(&tp->t_rawq);
tp->t_rocount = 0;
tp->t_rocol = 0;
CLR(tp->t_state, TS_LOCAL);
ttwakeup(tp);
}
if (rw & FWRITE) {
CLR(tp->t_state, TS_TTSTOP);
cdev = cdevsw_lookup(tp->t_dev);
if (cdev != NULL)
(*cdev->d_stop)(tp, rw);
FLUSHQ(&tp->t_outq);
wakeup((void *)&tp->t_outq);
selnotify(&tp->t_wsel, NOTE_SUBMIT);
}
}
/*
* Copy in the default termios characters.
*/
void
ttychars(struct tty *tp)
{
memcpy(tp->t_cc, ttydefchars, sizeof(ttydefchars));
}
/*
* Send stop character on input overflow.
* Call at spltty() and with the tty slock held.
*/
static void
ttyblock(struct tty *tp)
{
int total;
total = tp->t_rawq.c_cc + tp->t_canq.c_cc;
if (tp->t_rawq.c_cc > TTYHOG) {
ttyflush(tp, FREAD | FWRITE);
CLR(tp->t_state, TS_TBLOCK);
}
/*
* Block further input iff: current input > threshold
* AND input is available to user program.
*/
if (total >= TTYHOG / 2 &&
!ISSET(tp->t_state, TS_TBLOCK) &&
(!ISSET(tp->t_lflag, ICANON) || tp->t_canq.c_cc > 0)) {
if (ISSET(tp->t_iflag, IXOFF) &&
tp->t_cc[VSTOP] != _POSIX_VDISABLE &&
putc(tp->t_cc[VSTOP], &tp->t_outq) == 0) {
SET(tp->t_state, TS_TBLOCK);
ttstart(tp);
}
/* Try to block remote output via hardware flow control. */
if (ISSET(tp->t_cflag, CHWFLOW) && tp->t_hwiflow &&
(*tp->t_hwiflow)(tp, 1) != 0)
SET(tp->t_state, TS_TBLOCK);
}
}
/*
* Delayed line discipline output
*/
void
ttrstrt(void *tp_arg)
{
struct tty *tp;
int s;
#ifdef DIAGNOSTIC
if (tp_arg == NULL)
panic("ttrstrt");
#endif
tp = tp_arg;
s = spltty();
TTY_LOCK(tp);
CLR(tp->t_state, TS_TIMEOUT);
ttstart(tp); /* XXX - Shouldn't this be tp->l_start(tp)? */
TTY_UNLOCK(tp);
splx(s);
}
/*
* start a line discipline
* Always call at spltty() and with tty slock held?
*/
int
ttstart(struct tty *tp)
{
if (tp->t_oproc != NULL) /* XXX: Kludge for pty. */
(*tp->t_oproc)(tp);
return (0);
}
/*
* "close" a line discipline
*/
int
ttylclose(struct tty *tp, int flag)
{
int s;
if (flag & FNONBLOCK) {
s = spltty();
TTY_LOCK(tp);
ttyflush(tp, FREAD | FWRITE);
TTY_UNLOCK(tp);
splx(s);
} else
ttywflush(tp);
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.
*
* Must be called at spltty().
* XXX except that it is often isn't, which should be fixed.
*/
int
ttymodem(struct tty *tp, int flag)
{
int s;
s = spltty();
TTY_LOCK(tp);
if (flag == 0) {
if (ISSET(tp->t_state, TS_CARR_ON)) {
/*
* Lost carrier.
*/
CLR(tp->t_state, TS_CARR_ON);
if (ISSET(tp->t_state, TS_ISOPEN) && !CONNECTED(tp)) {
if (tp->t_session && tp->t_session->s_leader) {
mutex_enter(&proclist_mutex);
psignal(tp->t_session->s_leader,
SIGHUP);
mutex_exit(&proclist_mutex);
}
ttyflush(tp, FREAD | FWRITE);
TTY_UNLOCK(tp);
splx(s);
return (0);
}
}
} else {
if (!ISSET(tp->t_state, TS_CARR_ON)) {
/*
* Carrier now on.
*/
SET(tp->t_state, TS_CARR_ON);
ttwakeup(tp);
}
}
TTY_UNLOCK(tp);
splx(s);
return (1);
}
/*
* Default modem control routine (for other line disciplines).
* Return argument flag, to turn off device on carrier drop.
*
* Must be called at spltty().
* XXX except that it is often isn't, which should be fixed.
*/
int
nullmodem(struct tty *tp, int flag)
{
int s;
s = spltty();
TTY_LOCK(tp);
if (flag)
SET(tp->t_state, TS_CARR_ON);
else {
CLR(tp->t_state, TS_CARR_ON);
if (!CONNECTED(tp)) {
if (tp->t_session && tp->t_session->s_leader) {
mutex_enter(&proclist_mutex);
psignal(tp->t_session->s_leader, SIGHUP);
mutex_exit(&proclist_mutex);
}
TTY_UNLOCK(tp);
splx(s);
return (0);
}
}
TTY_UNLOCK(tp);
splx(s);
return (1);
}
/*
* Reinput pending characters after state switch.
* Call at spltty() and with the tty slock held.
*/
void
ttypend(struct tty *tp)
{
struct clist tq;
int c;
CLR(tp->t_lflag, PENDIN);
SET(tp->t_state, TS_TYPEN);
tq = tp->t_rawq;
tp->t_rawq.c_cc = 0;
tp->t_rawq.c_cf = tp->t_rawq.c_cl = 0;
while ((c = getc(&tq)) >= 0)
ttyinput_wlock(c, tp);
CLR(tp->t_state, TS_TYPEN);
}
/*
* Process a read call on a tty device.
*/
int
ttread(struct tty *tp, struct uio *uio, int flag)
{
struct clist *qp;
u_char *cc;
struct proc *p;
int c, s, first, error, has_stime, last_cc;
long lflag, slp;
struct timeval now, stime;
stime.tv_usec = 0; /* XXX gcc */
stime.tv_sec = 0; /* XXX gcc */
cc = tp->t_cc;
p = curproc;
error = 0;
has_stime = 0;
last_cc = 0;
slp = 0;
loop:
s = spltty();
TTY_LOCK(tp);
lflag = tp->t_lflag;
/*
* take pending input first
*/
if (ISSET(lflag, PENDIN))
ttypend(tp);
/*
* Hang process if it's in the background. XXXSMP
*/
if (isbackground(p, tp)) {
if (sigismember(&p->p_sigctx.ps_sigignore, SIGTTIN) ||
sigismember(&curlwp->l_sigmask, SIGTTIN) ||
p->p_sflag & PS_PPWAIT || p->p_pgrp->pg_jobc == 0) {
TTY_UNLOCK(tp);
splx(s);
return (EIO);
}
mutex_enter(&proclist_mutex);
pgsignal(p->p_pgrp, SIGTTIN, 1);
mutex_exit(&proclist_mutex);
error = ttysleep(tp, &lbolt, TTIPRI | PCATCH | PNORELOCK, ttybg, 0);
splx(s);
if (error)
return (error);
goto loop;
}
if (!ISSET(lflag, ICANON)) {
int m = cc[VMIN];
long t = cc[VTIME];
qp = &tp->t_rawq;
/*
* 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;
goto read;
}
t *= hz; /* time in deca-ticks */
/*
* Time difference in deca-ticks, split division to avoid numeric overflow.
* Ok for hz < ~200kHz
*/
#define diff(t1, t2) (((t1).tv_sec - (t2).tv_sec) * 10 * hz + \
((t1).tv_usec - (t2).tv_usec) / 100 * hz / 1000)
if (m > 0) {
if (qp->c_cc <= 0)
goto sleep;
if (qp->c_cc >= m)
goto read;
if (!has_stime) {
/* first character, start timer */
has_stime = 1;
getmicrotime(&stime);
slp = t;
} else if (qp->c_cc > last_cc) {
/* got a character, restart timer */
getmicrotime(&stime);
slp = t;
} else {
/* nothing, check expiration */
getmicrotime(&now);
slp = t - diff(now, stime);
}
} else { /* m == 0 */
if (qp->c_cc > 0)
goto read;
if (!has_stime) {
has_stime = 1;
getmicrotime(&stime);
slp = t;
} else {
getmicrotime(&now);
slp = t - diff(now, stime);
}
}
last_cc = qp->c_cc;
#undef diff
if (slp > 0) {
/*
* Convert deca-ticks back to ticks.
* Rounding down may make us wake up just short
* of the target, so we round up.
* Maybe we should do 'slp/10 + 1' because the
* first tick maybe almost immediate.
* However it is more useful for a program that sets
* VTIME=10 to wakeup every second not every 1.01
* seconds (if hz=100).
*/
slp = (slp + 9)/ 10;
goto sleep;
}
} else if ((qp = &tp->t_canq)->c_cc <= 0) {
int carrier;
sleep:
/*
* If there is no input, sleep on rawq
* awaiting hardware receipt and notification.
* If we have data, we don't need to check for carrier.
*/
carrier = CONNECTED(tp);
if (!carrier && ISSET(tp->t_state, TS_ISOPEN)) {
TTY_UNLOCK(tp);
splx(s);
return (0); /* EOF */
}
if (flag & IO_NDELAY) {
TTY_UNLOCK(tp);
splx(s);
return (EWOULDBLOCK);
}
error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH | PNORELOCK,
carrier ? ttyin : ttopen, slp);
splx(s);
/* VMIN == 0: any quantity read satisfies */
if (cc[VMIN] == 0 && error == EWOULDBLOCK)
return (0);
if (error && error != EWOULDBLOCK)
return (error);
goto loop;
}
read:
TTY_UNLOCK(tp);
splx(s);
/*
* Input present, check for input mapping and processing.
*/
first = 1;
while ((c = getc(qp)) >= 0) {
/*
* delayed suspend (^Y)
*/
if (CCEQ(cc[VDSUSP], c) &&
ISSET(lflag, IEXTEN|ISIG) == (IEXTEN|ISIG)) {
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp, SIGTSTP, 1);
mutex_exit(&proclist_mutex);
if (first) {
s = spltty();
TTY_LOCK(tp);
error = ttysleep(tp, &lbolt,
TTIPRI | PCATCH | PNORELOCK, ttybg, 0);
splx(s);
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)
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;
}
/*
* Look to unblock output now that (presumably)
* the input queue has gone down.
*/
s = spltty();
TTY_LOCK(tp);
if (ISSET(tp->t_state, TS_TBLOCK) && tp->t_rawq.c_cc < TTYHOG / 5) {
if (ISSET(tp->t_iflag, IXOFF) &&
cc[VSTART] != _POSIX_VDISABLE &&
putc(cc[VSTART], &tp->t_outq) == 0) {
CLR(tp->t_state, TS_TBLOCK);
ttstart(tp);
}
/* Try to unblock remote output via hardware flow control. */
if (ISSET(tp->t_cflag, CHWFLOW) && tp->t_hwiflow &&
(*tp->t_hwiflow)(tp, 0) != 0)
CLR(tp->t_state, TS_TBLOCK);
}
TTY_UNLOCK(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.
* Call with tty slock held.
*/
static int
ttycheckoutq_wlock(struct tty *tp, int wait)
{
int hiwat, s, error;
hiwat = tp->t_hiwat;
s = spltty();
if (tp->t_outq.c_cc > hiwat + 200)
while (tp->t_outq.c_cc > hiwat) {
ttstart(tp);
if (wait == 0) {
splx(s);
return (0);
}
SET(tp->t_state, TS_ASLEEP);
error = ltsleep(&tp->t_outq, (PZERO - 1) | PCATCH,
"ttckoutq", hz, &tp->t_slock);
if (error == EINTR)
wait = 0;
}
splx(s);
return (1);
}
int
ttycheckoutq(struct tty *tp, int wait)
{
int r, s;
s = spltty();
TTY_LOCK(tp);
r = ttycheckoutq_wlock(tp, wait);
TTY_UNLOCK(tp);
splx(s);
return (r);
}
/*
* Process a write call on a tty device.
*/
int
ttwrite(struct tty *tp, struct uio *uio, int flag)
{
u_char *cp;
struct proc *p;
int cc, ce, i, hiwat, error, s;
size_t cnt;
u_char obuf[OBUFSIZ];
cp = NULL;
hiwat = tp->t_hiwat;
cnt = uio->uio_resid;
error = 0;
cc = 0;
loop:
s = spltty();
TTY_LOCK(tp);
if (!CONNECTED(tp)) {
if (ISSET(tp->t_state, TS_ISOPEN)) {
TTY_UNLOCK(tp);
splx(s);
return (EIO);
} else if (flag & IO_NDELAY) {
TTY_UNLOCK(tp);
splx(s);
error = EWOULDBLOCK;
goto out;
} else {
/* Sleep awaiting carrier. */
error = ttysleep(tp,
&tp->t_rawq, TTIPRI | PCATCH | PNORELOCK, ttopen, 0);
splx(s);
if (error)
goto out;
goto loop;
}
}
TTY_UNLOCK(tp);
splx(s);
/*
* Hang the process if it's in the background. XXXSMP
*/
p = curproc;
if (isbackground(p, tp) &&
ISSET(tp->t_lflag, TOSTOP) && (p->p_sflag & PS_PPWAIT) == 0 &&
!sigismember(&p->p_sigctx.ps_sigignore, SIGTTOU) &&
!sigismember(&curlwp->l_sigmask, SIGTTOU)) {
if (p->p_pgrp->pg_jobc == 0) {
error = EIO;
goto out;
}
mutex_enter(&proclist_mutex);
pgsignal(p->p_pgrp, SIGTTOU, 1);
mutex_exit(&proclist_mutex);
s = spltty();
TTY_LOCK(tp);
error = ttysleep(tp, &lbolt, TTIPRI | PCATCH | PNORELOCK, ttybg, 0);
splx(s);
if (error)
goto out;
goto loop;
}
/*
* 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 = min(uio->uio_resid, OBUFSIZ);
cp = obuf;
error = uiomove(cp, cc, uio);
if (error) {
cc = 0;
goto out;
}
}
/*
* 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.
*/
s = spltty();
TTY_LOCK(tp);
while (cc > 0) {
if (!ISSET(tp->t_oflag, OPOST))
ce = cc;
else {
ce = cc - scanc((u_int)cc, 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) {
/* out of space */
TTY_UNLOCK(tp);
splx(s);
goto overfull;
}
cp++;
cc--;
if (ISSET(tp->t_lflag, FLUSHO) ||
tp->t_outq.c_cc > hiwat) {
TTY_UNLOCK(tp);
splx(s);
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) {
/* out of space */
TTY_UNLOCK(tp);
splx(s);
goto overfull;
}
if (ISSET(tp->t_lflag, FLUSHO) ||
tp->t_outq.c_cc > hiwat)
break;
}
TTY_UNLOCK(tp);
splx(s);
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);
overfull:
/*
* Since we are using ring buffers, if we can't insert any more into
* the output queue, we can assume the ring is full and that someone
* forgot to set the high water mark correctly. We set it and then
* proceed as normal.
*/
hiwat = tp->t_outq.c_cc - 1;
ovhiwat:
ttstart(tp);
s = spltty();
TTY_LOCK(tp);
/*
* 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) {
TTY_UNLOCK(tp);
splx(s);
goto loop;
}
if (flag & IO_NDELAY) {
TTY_UNLOCK(tp);
splx(s);
error = EWOULDBLOCK;
goto out;
}
SET(tp->t_state, TS_ASLEEP);
error = ttysleep(tp, &tp->t_outq, TTOPRI | PCATCH | PNORELOCK, ttyout, 0);
splx(s);
if (error)
goto out;
goto loop;
}
/*
* Rubout one character from the rawq of tp
* as cleanly as possible.
* Called with tty slock held.
*/
void
ttyrub(int c, struct tty *tp)
{
u_char *cp;
int savecol, 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;
for (cp = firstc(&tp->t_rawq, &tabc); 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 */
(void)printf("ttyrub: would panic c = %d, "
"val = %d\n", c, CCLASS(c));
}
}
} 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);
--tp->t_rocount;
}
/*
* Back over cnt characters, erasing them.
* Called with tty slock held.
*/
static void
ttyrubo(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.
*
* Called with tty slock held.
*/
void
ttyretype(struct tty *tp)
{
u_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);
s = spltty();
for (cp = firstc(&tp->t_canq, &c); cp; cp = nextc(&tp->t_canq, cp, &c))
ttyecho(c, tp);
for (cp = firstc(&tp->t_rawq, &c); cp; 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.
* Called with tty slock held.
*/
static void
ttyecho(int c, struct tty *tp)
{
if (!ISSET(tp->t_state, TS_CNTTB))
CLR(tp->t_lflag, FLUSHO);
if ((!ISSET(tp->t_lflag, ECHO) &&
(!ISSET(tp->t_lflag, ECHONL) || c != '\n')) ||
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.
* Called with tty slock held.
*/
void
ttwakeup(struct tty *tp)
{
selnotify(&tp->t_rsel, NOTE_SUBMIT);
if (ISSET(tp->t_state, TS_ASYNC)) {
mutex_enter(&proclist_mutex);
pgsignal(tp->t_pgrp, SIGIO, tp->t_session != NULL);
mutex_exit(&proclist_mutex);
}
wakeup((void *)&tp->t_rawq);
}
/*
* 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(int speed, const struct speedtab *table)
{
for (; table->sp_speed != -1; table++)
if (table->sp_speed == speed)
return (table->sp_code);
return (-1);
}
/*
* Set tty hi and low water marks.
*
* Try to arrange the dynamics so there's about one second
* from hi to low water.
*/
void
ttsetwater(struct tty *tp)
{
int cps, x;
#define CLAMP(x, h, l) ((x) > h ? h : ((x) < l) ? l : (x))
cps = tp->t_ospeed / 10;
tp->t_lowat = x = CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
x += cps;
x = CLAMP(x, TTMAXHIWAT, TTMINHIWAT);
tp->t_hiwat = roundup(x, CBSIZE);
#undef CLAMP
}
/*
* Report on state of foreground process group.
* Call with tty slock held.
* XXXSMP locking.
*/
void
ttyinfo(struct tty *tp, int fromsig)
{
struct lwp *l;
struct proc *p, *pick = NULL;
struct timeval utime, stime;
int tmp;
fixpt_t pctcpu = 0;
const char *msg;
if (ttycheckoutq_wlock(tp, 0) == 0)
return;
if (tp->t_session == NULL)
msg = "not a controlling terminal\n";
else if (tp->t_pgrp == NULL)
msg = "no foreground process group\n";
else if ((p = LIST_FIRST(&tp->t_pgrp->pg_members)) == NULL)
msg = "empty foreground process group\n";
else {
/* Pick interesting process. */
for (; p != NULL; p = LIST_NEXT(p, p_pglist))
if (proc_compare(pick, p))
pick = p;
if (fromsig &&
(SIGACTION_PS(pick->p_sigacts, SIGINFO).sa_flags &
SA_NOKERNINFO))
return;
msg = NULL;
}
/* Print load average. */
tmp = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
ttyprintf_nolock(tp, "load: %d.%02d ", tmp / 100, tmp % 100);
if (pick == NULL) {
ttyprintf_nolock(tp, msg);
tp->t_rocount = 0; /* so pending input will be retyped if BS */
return;
}
ttyprintf_nolock(tp, " cmd: %s %d [", pick->p_comm, pick->p_pid);
LIST_FOREACH(l, &pick->p_lwps, l_sibling) {
ttyprintf_nolock(tp, "%s%s",
l->l_stat == LSONPROC ? "running" :
l->l_stat == LSRUN ? "runnable" :
l->l_wmesg ? l->l_wmesg : "iowait",
(LIST_NEXT(l, l_sibling) != NULL) ? " " : "] ");
pctcpu += l->l_pctcpu;
}
pctcpu += pick->p_pctcpu;
mutex_enter(&pick->p_smutex);
calcru(pick, &utime, &stime, NULL, NULL);
mutex_exit(&pick->p_smutex);
/* Round up and print user time. */
utime.tv_usec += 5000;
if (utime.tv_usec >= 1000000) {
utime.tv_sec += 1;
utime.tv_usec -= 1000000;
}
ttyprintf_nolock(tp, "%ld.%02ldu ", (long int)utime.tv_sec,
(long int)utime.tv_usec / 10000);
/* Round up and print system time. */
stime.tv_usec += 5000;
if (stime.tv_usec >= 1000000) {
stime.tv_sec += 1;
stime.tv_usec -= 1000000;
}
ttyprintf_nolock(tp, "%ld.%02lds ", (long int)stime.tv_sec,
(long int)stime.tv_usec / 10000);
#define pgtok(a) (((u_long) ((a) * PAGE_SIZE) / 1024))
/* Print percentage CPU. */
tmp = (pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
ttyprintf_nolock(tp, "%d%% ", tmp / 100);
/* Print resident set size. */
if (pick->p_stat == SIDL || P_ZOMBIE(pick))
tmp = 0;
else {
struct vmspace *vm = pick->p_vmspace;
tmp = pgtok(vm_resident_count(vm));
}
ttyprintf_nolock(tp, "%dk\n", tmp);
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.
*
* XXXSMP
*/
#define ISRUN(p) ((p)->p_nrlwps > 0)
#define TESTAB(a, b) ((a)<<1 | (b))
#define ONLYA 2
#define ONLYB 1
#define BOTH 3
static int
proc_compare(struct proc *p1, struct proc *p2)
{
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
*/
if (p2->p_estcpu > p1->p_estcpu)
return (1);
if (p1->p_estcpu > p2->p_estcpu)
return (0);
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
/*
* weed out zombies
*/
switch (TESTAB(P_ZOMBIE(p1), P_ZOMBIE(p2))) {
case ONLYA:
return (1);
case ONLYB:
return (0);
case BOTH:
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
#if 0 /* XXX NJWLWP */
/*
* 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_flag & P_SINTR && (p2->p_flag & P_SINTR) == 0)
return (1);
if (p2->p_flag & P_SINTR && (p1->p_flag & P_SINTR) == 0)
return (0);
#endif
return (p2->p_pid > p1->p_pid); /* tie - return highest pid */
}
/*
* Output char to tty; console putchar style.
* Can be called with tty lock held through kprintf() machinery..
*/
int
tputchar(int c, int flags, struct tty *tp)
{
int s, r = 0;
s = spltty();
if ((flags & NOLOCK) == 0)
simple_lock(&tp->t_slock);
if (!CONNECTED(tp)) {
r = -1;
goto out;
}
if (c == '\n')
(void)ttyoutput('\r', tp);
(void)ttyoutput(c, tp);
ttstart(tp);
out:
if ((flags & NOLOCK) == 0)
TTY_UNLOCK(tp);
splx(s);
return (r);
}
/*
* Sleep on chan, returning ERESTART if tty changed while we napped and
* returning any errors (e.g. EINTR/ETIMEDOUT) reported by tsleep. If
* the tty is revoked, restarting a pending call will redo validation done
* at the start of the call.
*
* Must be called with the tty slock held.
*/
int
ttysleep(struct tty *tp, void *chan, int pri, const char *wmesg, int timo)
{
int error;
short gen;
gen = tp->t_gen;
if ((error = ltsleep(chan, pri, wmesg, timo, &tp->t_slock)) != 0)
return (error);
return (tp->t_gen == gen ? 0 : ERESTART);
}
/*
* Attach a tty to the tty list.
*
* This should be called ONLY once per real tty (including pty's).
* eg, on the sparc, the keyboard and mouse have struct tty's that are
* distinctly NOT usable as tty's, and thus should not be attached to
* the ttylist. This is why this call is not done from ttymalloc().
*
* Device drivers should attach tty's at a similar time that they are
* ttymalloc()'ed, or, for the case of statically allocated struct tty's
* either in the attach or (first) open routine.
*/
void
tty_attach(struct tty *tp)
{
static bool again;
if (!again) {
again = true;
mutex_init(&ttylist_lock, MUTEX_DEFAULT, IPL_NONE);
}
mutex_enter(&ttylist_lock);
TAILQ_INSERT_TAIL(&ttylist, tp, tty_link);
++tty_count;
mutex_exit(&ttylist_lock);
}
/*
* Remove a tty from the tty list.
*/
void
tty_detach(struct tty *tp)
{
mutex_enter(&ttylist_lock);
--tty_count;
#ifdef DIAGNOSTIC
if (tty_count < 0)
panic("tty_detach: tty_count < 0");
#endif
TAILQ_REMOVE(&ttylist, tp, tty_link);
mutex_exit(&ttylist_lock);
}
/*
* Allocate a tty structure and its associated buffers.
*/
struct tty *
ttymalloc(void)
{
struct tty *tp;
tp = pool_get(&tty_pool, PR_WAITOK);
memset(tp, 0, sizeof(*tp));
simple_lock_init(&tp->t_slock);
callout_init(&tp->t_rstrt_ch, 0);
/* XXX: default to 1024 chars for now */
clalloc(&tp->t_rawq, 1024, 1);
clalloc(&tp->t_canq, 1024, 1);
/* output queue doesn't need quoting */
clalloc(&tp->t_outq, 1024, 0);
/* Set default line discipline. */
tp->t_linesw = ttyldisc_default();
selinit(&tp->t_rsel);
selinit(&tp->t_wsel);
return (tp);
}
/*
* Free a tty structure and its buffers.
*
* Be sure to call tty_detach() for any tty that has been
* tty_attach()ed.
*/
void
ttyfree(struct tty *tp)
{
callout_stop(&tp->t_rstrt_ch);
ttyldisc_release(tp->t_linesw);
clfree(&tp->t_rawq);
clfree(&tp->t_canq);
clfree(&tp->t_outq);
seldestroy(&tp->t_rsel);
seldestroy(&tp->t_wsel);
pool_put(&tty_pool, tp);
}
/*
* ttyprintf_nolock: send a message to a specific tty, without locking.
*
* => should be used only by tty driver or anything that knows the
* underlying tty will not be revoked(2)'d away. [otherwise,
* use tprintf]
*/
static void
ttyprintf_nolock(struct tty *tp, const char *fmt, ...)
{
va_list ap;
/* No mutex needed; going to process TTY. */
va_start(ap, fmt);
kprintf(fmt, TOTTY|NOLOCK, tp, NULL, ap);
va_end(ap);
}
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