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feature/arm-support
darling-xnu/bsd/kern/tty.c
Thomas A cdbc10b677 Upload xnu-7195.141.2 Source
2023-05-16 21:41:14 -07:00

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/*
* Copyright (c) 1997-2019 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*-
* 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
*/
/*-
* 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 <sys/ioctl.h>.
* 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 Handle c_ispeed = 0 to c_ispeed = c_ospeed conversion here instead
* of in drivers and fix drivers that write to tp->t_termios.
* 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 <sys/param.h>
#define TTYDEFCHARS 1
#include <sys/systm.h>
#undef TTYDEFCHARS
#include <sys/ioctl.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/file_internal.h>
#include <sys/conf.h>
#include <sys/dkstat.h>
#include <sys/uio_internal.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/user.h>
#include <sys/signalvar.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <dev/kmreg_com.h>
#include <machine/cons.h>
#include <sys/resource.h> /* averunnable */
#include <kern/waitq.h>
#include <libkern/section_keywords.h>
static LCK_GRP_DECLARE(tty_lck_grp, "tty");
__private_extern__ int ttnread(struct tty *tp);
static void ttyecho(int c, struct tty *tp);
static int ttyoutput(int c, 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 count);
static void ttystop(struct tty *tp, int rw);
static void ttyunblock(struct tty *tp);
static int ttywflush(struct tty *tp);
static int proc_compare(proc_t p1, proc_t p2);
void ttyhold(struct tty *tp);
static void ttydeallocate(struct tty *tp);
static int isctty(proc_t p, struct tty *tp);
static int isctty_sp(proc_t p, struct tty *tp, struct session *sessp);
__private_extern__ void termios32to64(struct termios32 *in, struct user_termios *out);
__private_extern__ void termios64to32(struct user_termios *in, struct termios32 *out);
/*
* 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)
/* 0b10xxxxxx is the mask for UTF-8 continuations */
#define CCONT(c) ((c & 0xc0) == 0x80)
#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))
/*
* Input control starts when we would not be able to fit the maximum
* contents of the ping-pong buffers and finishes when we would be able
* to fit that much plus 1/8 more.
*/
#define I_HIGH_WATER (TTYHOG - 2 * 256) /* XXX */
#define I_LOW_WATER ((TTYHOG - 2 * 256) * 7 / 8) /* XXX */
__private_extern__ void
termios32to64(struct termios32 *in, struct user_termios *out)
{
out->c_iflag = (user_tcflag_t)in->c_iflag;
out->c_oflag = (user_tcflag_t)in->c_oflag;
out->c_cflag = (user_tcflag_t)in->c_cflag;
out->c_lflag = (user_tcflag_t)in->c_lflag;
/* bcopy is OK, since this type is ILP32/LP64 size invariant */
bcopy(in->c_cc, out->c_cc, sizeof(in->c_cc));
out->c_ispeed = (user_speed_t)in->c_ispeed;
out->c_ospeed = (user_speed_t)in->c_ospeed;
}
__private_extern__ void
termios64to32(struct user_termios *in, struct termios32 *out)
{
out->c_iflag = (uint32_t)in->c_iflag;
out->c_oflag = (uint32_t)in->c_oflag;
out->c_cflag = (uint32_t)in->c_cflag;
out->c_lflag = (uint32_t)in->c_lflag;
/* bcopy is OK, since this type is ILP32/LP64 size invariant */
bcopy(in->c_cc, out->c_cc, sizeof(in->c_cc));
out->c_ispeed = (uint32_t)MIN(in->c_ispeed, UINT32_MAX);
out->c_ospeed = (uint32_t)MIN(in->c_ospeed, UINT32_MAX);
}
/*
* tty_lock
*
* Lock the requested tty structure.
*
* Parameters: tp The tty we want to lock
*
* Returns: void
*
* Locks: On return, tp is locked
*/
void
tty_lock(struct tty *tp)
{
TTY_LOCK_NOTOWNED(tp); /* debug assert */
lck_mtx_lock(&tp->t_lock);
}
/*
* tty_unlock
*
* Unlock the requested tty structure.
*
* Parameters: tp The tty we want to unlock
*
* Returns: void
*
* Locks: On return, tp is unlocked
*/
void
tty_unlock(struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
lck_mtx_unlock(&tp->t_lock);
}
/*
* ttyopen (LDISC)
*
* Initial open of tty, or (re)entry to standard tty line discipline.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttyopen(dev_t device, struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
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));
}
return 0;
}
/*
* ttyclose
*
* 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.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttyclose(struct tty *tp)
{
struct pgrp * oldpg;
struct session * oldsessp;
struct knote *kn;
TTY_LOCK_OWNED(tp); /* debug assert */
if (constty == tp) {
constty = NULL;
/*
* Closing current console tty; disable printing of console
* messages at bottom-level driver.
*/
(*cdevsw[major(tp->t_dev)].d_ioctl)
(tp->t_dev, KMIOCDISABLCONS, NULL, 0, current_proc());
}
ttyflush(tp, FREAD | FWRITE);
tp->t_gen++;
tp->t_line = TTYDISC;
proc_list_lock();
oldpg = tp->t_pgrp;
oldsessp = tp->t_session;
tp->t_pgrp = NULL;
tp->t_session = NULL;
if (oldsessp != SESSION_NULL) {
oldsessp->s_ttypgrpid = NO_PID;
}
proc_list_unlock();
/* drop the reference on prev session and pgrp */
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
if (oldsessp != SESSION_NULL) {
session_rele(oldsessp);
}
if (oldpg != PGRP_NULL) {
pg_rele(oldpg);
}
tty_lock(tp);
tp->t_state = 0;
SLIST_FOREACH(kn, &tp->t_wsel.si_note, kn_selnext) {
KNOTE_DETACH(&tp->t_wsel.si_note, kn);
}
selthreadclear(&tp->t_wsel);
SLIST_FOREACH(kn, &tp->t_rsel.si_note, kn_selnext) {
KNOTE_DETACH(&tp->t_rsel.si_note, kn);
}
selthreadclear(&tp->t_rsel);
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))
/*
* ttyinput (LDISC)
*
* Process input of a single character received on a tty.
*
* Parameters: c The character received
* tp The tty on which it was received
*
* Returns: .
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttyinput(int c, struct tty *tp)
{
tcflag_t iflag, lflag;
cc_t *cc;
int i, err;
int retval = 0; /* default return value */
TTY_LOCK_OWNED(tp); /* debug assert */
/*
* 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 > I_HIGH_WATER - 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)) {
goto out;
}
if (ISSET(iflag, BRKINT)) {
ttyflush(tp, FREAD | FWRITE);
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
tty_pgsignal(tp, SIGINT, 1);
tty_lock(tp);
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)) {
goto out;
} 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);
/*
* SAFE: All callers drop the lock on return;
* SAFE: if we lose a threaded race on change
* SAFE: of the interrupt character, we could
* SAFE: have lost that race anyway due to the
* SAFE: scheduler executing threads in
* SAFE: priority order rather than "last
* SAFE: active thread" order (FEATURE).
*/
tty_unlock(tp);
tty_pgsignal(tp,
CCEQ(cc[VINTR], c) ? SIGINT : SIGQUIT, 1);
tty_lock(tp);
goto endcase;
}
if (CCEQ(cc[VSUSP], c)) {
if (!ISSET(lflag, NOFLSH)) {
ttyflush(tp, FREAD);
}
ttyecho(c, tp);
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
tty_pgsignal(tp, SIGTSTP, 1);
tty_lock(tp);
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);
ttystop(tp, 0);
goto out;
}
if (!CCEQ(cc[VSTART], c)) {
goto out;
}
/*
* 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 out;
} 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 (^H / ^?)
*/
if (CCEQ(cc[VERASE], c)) {
if (tp->t_rawq.c_cc) {
if (ISSET(iflag, IUTF8)) {
do {
ttyrub((c = unputc(&tp->t_rawq)), tp);
} while (tp->t_rawq.c_cc && CCONT(c));
} else {
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)) {
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
tty_pgsignal(tp, SIGINFO, 1);
tty_lock(tp);
}
if (!ISSET(lflag, NOKERNINFO)) {
ttyinfo_locked(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_hiwat) {
(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 = 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]) {
goto out;
}
restartoutput:
CLR(tp->t_lflag, FLUSHO);
CLR(tp->t_state, TS_TTSTOP);
startoutput:
/* Start the output */
retval = ttstart(tp);
out:
return retval;
}
/*
* ttyoutput
*
* Output a single character on a tty, doing output processing
* as needed (expanding tabs, newline processing, etc.).
*
* Parameters: c The character to output
* tp The tty on which to output on the tty
*
* Returns: < 0 Success
* >= 0 Character to resend (failure)
*
* Locks: Assumes tp is locked on entry, remains locked on exit
*
* Notes: Must be recursive.
*/
static int
ttyoutput(int c, struct tty *tp)
{
tcflag_t oflag;
int col;
TTY_LOCK_OWNED(tp); /* debug assert */
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)) {
col = c = 8 - (tp->t_column & 7);
if (!ISSET(tp->t_lflag, FLUSHO)) {
c -= b_to_q((const u_char *)" ", c, &tp->t_outq);
tk_nout += c;
tp->t_outcc += c;
}
tp->t_column += c;
return c == col ? -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 (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:
case RETURN:
col = 0;
break;
case ORDINARY:
++col;
break;
case TAB:
col = (col + 8) & ~7;
break;
}
tp->t_column = col;
return -1;
}
/*
* ttioctl
*
* Identical to ttioctl_locked, only the lock is not held
*
* Parameters: <See ttioctl_locked()>
*
* Returns: <See ttioctl_locked()>
*
* Locks: This function assumes the tty_lock() is not held on entry;
* it takes the lock, and releases it before returning.
*
* Notes: This is supported to ensure the line discipline interfaces
* all have the same locking semantics.
*
* This function is called from
*/
int
ttioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, proc_t p)
{
int retval;
tty_lock(tp);
retval = ttioctl_locked(tp, cmd, data, flag, p);
tty_unlock(tp);
return retval;
}
/*
* ttioctl_locked
*
* Ioctls for all tty devices.
*
* Parameters: tp Tty on which ioctl() is being called
* cmd ioctl() command parameter
* data ioctl() data argument (if any)
* flag fileglob open modes from fcntl.h;
* if called internally, this is usually
* set to 0, rather than something useful
* p Process context for the call; if the
* call is proxied to a worker thread,
* this will not be the current process!!!
*
* Returns: 0 Success
* EIO I/O error (no process group, job
* control, etc.)
* EINTR Interrupted by signal
* EBUSY Attempt to become the console while
* the console is busy
* ENOTTY TIOCGPGRP on a non-controlling tty
* EINVAL Invalid baud rate
* ENXIO TIOCSETD of invalid line discipline
* EPERM TIOCSTI, not root, not open for read
* EACCES TIOCSTI, not root, not your controlling
* tty
* EPERM TIOCSCTTY failed
* ENOTTY/EINVAL/EPERM TIOCSPGRP failed
* EPERM TIOCSDRAINWAIT as non-root user
* suser:EPERM Console control denied
* ttywait:EIO t_timeout too small/expired
* ttywait:ERESTART Upper layer must redrive the call;
* this is usually done by the Libc
* stub in user space
* ttywait:EINTR Interrupted (usually a signal)
* ttcompat:EINVAL
* ttcompat:ENOTTY
* ttcompat:EIOCTL
* ttcompat:ENOTTY TIOCGSID, if no session or session
* leader
* ttcompat:ENOTTY All unrecognized ioctls
* *tp->t_param:? TIOCSETA* underlying function
* *linesw[t].l_open:? TIOCSETD line discipline open failure
*
*
* Locks: This function assumes that the tty_lock() is held for the
* tp at the time of the call. The lock remains held on return.
*
* Notes: This function is called after line-discipline specific ioctl
* has been called to do discipline-specific functions and/or
* reject any of these ioctl() commands.
*
* This function calls ttcompat(), which can re-call ttioctl()
* to a depth of one (FORTRAN style mutual recursion); at some
* point, we should just in-line ttcompat() here.
*/
int
ttioctl_locked(struct tty *tp, u_long cmd, caddr_t data, int flag, proc_t p)
{
int error = 0;
int bogusData = 1;
struct uthread *ut;
struct pgrp *pg, *oldpg;
struct session *sessp, *oldsessp;
struct tty *oldtp;
TTY_LOCK_OWNED(tp); /* debug assert */
ut = (struct uthread *)get_bsdthread_info(current_thread());
/* If the ioctl involves modification, signal if in the background. */
switch (cmd) {
case TIOCIXON:
case TIOCIXOFF:
case TIOCDRAIN:
case TIOCFLUSH:
case TIOCSTOP:
case TIOCSTART:
case TIOCSETA_32:
case TIOCSETA_64:
case TIOCSETD:
case TIOCSETAF_32:
case TIOCSETAF_64:
case TIOCSETAW_32:
case TIOCSETAW_64:
case TIOCSPGRP:
case TIOCSTAT:
case TIOCSTI:
case TIOCSWINSZ:
case TIOCLBIC:
case TIOCLBIS:
case TIOCLSET:
case TIOCSETC:
case OTIOCSETD:
case TIOCSETN:
case TIOCSETP:
case TIOCSLTC:
while (isbackground(p, tp) &&
(p->p_lflag & P_LPPWAIT) == 0 &&
(p->p_sigignore & sigmask(SIGTTOU)) == 0 &&
(ut->uu_sigmask & sigmask(SIGTTOU)) == 0) {
pg = proc_pgrp(p);
if (pg == PGRP_NULL) {
error = EIO;
goto out;
}
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
if (pg->pg_jobc == 0) {
pg_rele(pg);
tty_lock(tp);
error = EIO;
goto out;
}
pgsignal(pg, SIGTTOU, 1);
pg_rele(pg);
tty_lock(tp);
/*
* We signalled ourself, so we need to act as if we
* have been "interrupted" from a "sleep" to act on
* the signal. If it's a signal that stops the
* process, that's handled in the signal sending code.
*/
error = EINTR;
goto out;
}
break;
}
switch (cmd) { /* Process the ioctl. */
case FIOASYNC: /* set/clear async i/o */
if (*(int *)data) {
SET(tp->t_state, TS_ASYNC);
} else {
CLR(tp->t_state, TS_ASYNC);
}
break;
case FIONBIO: /* set/clear non-blocking i/o */
break; /* XXX: delete. */
case FIONREAD: /* get # bytes to read */
*(int *)data = ttnread(tp);
break;
case TIOCEXCL: /* set exclusive use of tty */
SET(tp->t_state, TS_XCLUDE);
break;
case TIOCFLUSH: { /* flush buffers */
int flags = *(int *)data;
if (flags == 0) {
flags = FREAD | FWRITE;
} else {
flags &= FREAD | FWRITE;
}
ttyflush(tp, flags);
break;
}
case TIOCSCONS: {
/* Set current console device to this line */
data = (caddr_t) &bogusData;
}
OS_FALLTHROUGH;
case TIOCCONS: { /* become virtual console */
if (*(int *)data) {
if (constty && constty != tp &&
ISSET(constty->t_state, TS_CONNECTED)) {
error = EBUSY;
goto out;
}
if ((error = suser(kauth_cred_get(), &p->p_acflag))) {
goto out;
}
constty = tp;
} else if (tp == constty) {
constty = NULL;
}
if (constty) {
(*cdevsw[major(constty->t_dev)].d_ioctl)
(constty->t_dev, KMIOCDISABLCONS, NULL, 0, p);
} else {
(*cdevsw[major(tp->t_dev)].d_ioctl)
(tp->t_dev, KMIOCDISABLCONS, NULL, 0, p);
}
break;
}
case TIOCDRAIN: /* wait till output drained */
error = ttywait(tp);
if (error) {
goto out;
}
break;
case TIOCGETA_32: /* get termios struct */
#ifdef __LP64__
termios64to32((struct user_termios *)&tp->t_termios, (struct termios32 *)data);
#else
bcopy(&tp->t_termios, data, sizeof(struct termios));
#endif
break;
case TIOCGETA_64: /* get termios struct */
#ifdef __LP64__
bcopy(&tp->t_termios, data, sizeof(struct termios));
#else
termios32to64((struct termios32 *)&tp->t_termios, (struct user_termios *)data);
#endif
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)) {
error = ENOTTY;
goto out;
}
*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
break;
#ifdef TIOCHPCL
case TIOCHPCL: /* hang up on last close */
SET(tp->t_cflag, HUPCL);
break;
#endif
case TIOCNXCL: /* reset exclusive use of tty */
CLR(tp->t_state, TS_XCLUDE);
break;
case TIOCOUTQ: /* output queue size */
*(int *)data = tp->t_outq.c_cc;
break;
case TIOCSETA_32: /* set termios struct */
case TIOCSETA_64:
case TIOCSETAW_32: /* drain output, set */
case TIOCSETAW_64:
case TIOCSETAF_32: /* drn out, fls in, set */
case TIOCSETAF_64:
{ /* drn out, fls in, set */
struct termios *t = (struct termios *)data;
struct termios lcl_termios;
#ifdef __LP64__
if (cmd == TIOCSETA_32 || cmd == TIOCSETAW_32 || cmd == TIOCSETAF_32) {
termios32to64((struct termios32 *)data, (struct user_termios *)&lcl_termios);
t = &lcl_termios;
}
#else
if (cmd == TIOCSETA_64 || cmd == TIOCSETAW_64 || cmd == TIOCSETAF_64) {
termios64to32((struct user_termios *)data, (struct termios32 *)&lcl_termios);
t = &lcl_termios;
}
#endif
#if 0
/* XXX bogus test; always false */
if (t->c_ispeed < 0 || t->c_ospeed < 0) {
error = EINVAL;
goto out;
}
#endif /* 0 - leave in; may end up being a conformance issue */
if (t->c_ispeed == 0) {
t->c_ispeed = t->c_ospeed;
}
if (cmd == TIOCSETAW_32 || cmd == TIOCSETAF_32 ||
cmd == TIOCSETAW_64 || cmd == TIOCSETAF_64) {
error = ttywait(tp);
if (error) {
goto out;
}
if (cmd == TIOCSETAF_32 || cmd == TIOCSETAF_64) {
ttyflush(tp, FREAD);
}
}
if (!ISSET(t->c_cflag, CIGNORE)) {
/*
* Set device hardware.
*/
if (tp->t_param && (error = (*tp->t_param)(tp, t))) {
goto out;
}
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;
tp->t_ospeed = t->c_ospeed;
ttsetwater(tp);
}
if (ISSET(t->c_lflag, ICANON) != ISSET(tp->t_lflag, ICANON) &&
cmd != TIOCSETAF_32 && cmd != TIOCSETAF_64) {
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_rawq.c_cs && tp->t_canq.c_cs) {
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);
}
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));
break;
}
case TIOCSETD: { /* set line discipline */
int t = *(int *)data;
dev_t device = tp->t_dev;
if (t >= nlinesw || t < 0) {
error = ENXIO;
goto out;
}
/*
* If the new line discipline is not equal to the old one,
* close the old one and open the new one.
*/
if (t != tp->t_line) {
(*linesw[tp->t_line].l_close)(tp, flag);
error = (*linesw[t].l_open)(device, tp);
if (error) {
/* This is racy; it's possible to lose both */
(void)(*linesw[tp->t_line].l_open)(device, tp);
goto out;
}
tp->t_line = t;
}
break;
}
case TIOCSTART: /* start output, like ^Q */
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);
}
break;
case TIOCSTI: /* simulate terminal input */
if (suser(kauth_cred_get(), NULL) && (flag & FREAD) == 0) {
error = EPERM;
goto out;
}
if (suser(kauth_cred_get(), NULL) && !isctty(p, tp)) {
error = EACCES;
goto out;
}
(*linesw[tp->t_line].l_rint)(*(u_char *)data, tp);
break;
case TIOCSTOP: /* stop output, like ^S */
if (!ISSET(tp->t_state, TS_TTSTOP)) {
SET(tp->t_state, TS_TTSTOP);
ttystop(tp, 0);
}
break;
case TIOCIXON:
ttyunblock(tp);
break;
case TIOCIXOFF:
ttyblock(tp);
break;
case TIOCSCTTY: /* become controlling tty */
/* Session ctty vnode pointer set in vnode layer. */
sessp = proc_session(p);
if (sessp == SESSION_NULL) {
error = EPERM;
goto out;
}
/*
* This can only be done by a session leader.
*/
if (!SESS_LEADER(p, sessp)) {
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
session_rele(sessp);
tty_lock(tp);
error = EPERM;
goto out;
}
/*
* If this terminal is already the controlling terminal for the
* session, nothing to do here.
*/
if (tp->t_session == sessp) {
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
session_rele(sessp);
tty_lock(tp);
error = 0;
goto out;
}
pg = proc_pgrp(p);
/*
* Deny if the terminal is already attached to another session or
* the session already has a terminal vnode.
*/
session_lock(sessp);
if (sessp->s_ttyvp || tp->t_session) {
session_unlock(sessp);
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
if (pg != PGRP_NULL) {
pg_rele(pg);
}
session_rele(sessp);
tty_lock(tp);
error = EPERM;
goto out;
}
sessp->s_ttypgrpid = pg->pg_id;
oldtp = sessp->s_ttyp;
ttyhold(tp);
sessp->s_ttyp = tp;
session_unlock(sessp);
proc_list_lock();
oldsessp = tp->t_session;
oldpg = tp->t_pgrp;
if (oldsessp != SESSION_NULL) {
oldsessp->s_ttypgrpid = NO_PID;
}
/* do not drop refs on sessp and pg as tp holds them */
tp->t_session = sessp;
tp->t_pgrp = pg;
proc_list_unlock();
OSBitOrAtomic(P_CONTROLT, &p->p_flag);
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
/* drop the reference on prev session and pgrp */
if (oldsessp != SESSION_NULL) {
session_rele(oldsessp);
}
if (oldpg != PGRP_NULL) {
pg_rele(oldpg);
}
if (NULL != oldtp) {
ttyfree(oldtp);
}
tty_lock(tp);
break;
case TIOCSPGRP: { /* set pgrp of tty */
struct pgrp *pgrp = PGRP_NULL;
sessp = proc_session(p);
if (!isctty_sp(p, tp, sessp)) {
if (sessp != SESSION_NULL) {
session_rele(sessp);
}
error = ENOTTY;
goto out;
} else if ((pgrp = pgfind(*(int *)data)) == PGRP_NULL) {
if (sessp != SESSION_NULL) {
session_rele(sessp);
}
error = EINVAL;
goto out;
} else if (pgrp->pg_session != sessp) {
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
if (sessp != SESSION_NULL) {
session_rele(sessp);
}
pg_rele(pgrp);
tty_lock(tp);
error = EPERM;
goto out;
}
proc_list_lock();
oldpg = tp->t_pgrp;
tp->t_pgrp = pgrp;
sessp->s_ttypgrpid = pgrp->pg_id;
proc_list_unlock();
/*
* Wakeup readers to recheck if they are still the foreground
* process group.
*
* ttwakeup() isn't called because the readers aren't getting
* woken up because there is something to read but to force
* the re-evaluation of their foreground process group status.
*
* Ordinarily leaving these readers waiting wouldn't be an issue
* as launchd would send them a termination signal eventually
* (if nobody else does). But if this terminal happens to be
* /dev/console, launchd itself could get blocked forever behind
* a revoke of /dev/console and leave the system deadlocked.
*/
wakeup(TSA_HUP_OR_INPUT(tp));
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
if (oldpg != PGRP_NULL) {
pg_rele(oldpg);
}
if (sessp != SESSION_NULL) {
session_rele(sessp);
}
tty_lock(tp);
break;
}
case TIOCSTAT: /* simulate control-T */
ttyinfo_locked(tp);
break;
case TIOCSWINSZ: /* set window size */
if (bcmp((caddr_t)&tp->t_winsize, data,
sizeof(struct winsize))) {
tp->t_winsize = *(struct winsize *)data;
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
tty_pgsignal(tp, SIGWINCH, 1);
tty_lock(tp);
}
break;
case TIOCSDRAINWAIT:
error = suser(kauth_cred_get(), &p->p_acflag);
if (error) {
goto out;
}
tp->t_timeout = *(int *)data * hz;
wakeup(TSA_OCOMPLETE(tp));
wakeup(TSA_OLOWAT(tp));
break;
case TIOCGDRAINWAIT:
*(int *)data = tp->t_timeout / hz;
break;
case TIOCREVOKE:
SET(tp->t_state, TS_REVOKE);
tp->t_gen++;
/*
* At this time, only this wait channel is woken up as only
* ttread has been problematic. It is possible we may need
* to add wake up other tty wait addresses as well.
*/
wakeup(TSA_HUP_OR_INPUT(tp));
break;
case TIOCREVOKECLEAR:
CLR(tp->t_state, TS_REVOKE);
break;
default:
error = ttcompat(tp, cmd, data, flag, p);
goto out;
}
error = 0;
out:
return error;
}
/*
* Locks: Assumes tp is locked on entry, remains locked on exit
*/
int
ttyselect(struct tty *tp, int rw, void *wql, proc_t p)
{
int retval = 0;
/*
* Attaching knotes to TTYs needs to call selrecord in order to hook
* up the waitq to the selinfo, regardless of data being ready. See
* filt_ttyattach.
*/
bool needs_selrecord = rw & FMARK;
rw &= ~FMARK;
if (tp == NULL) {
return ENXIO;
}
TTY_LOCK_OWNED(tp);
if (tp->t_state & TS_ZOMBIE) {
retval = 1;
goto out;
}
switch (rw) {
case FREAD:
retval = ttnread(tp);
if (retval > 0) {
break;
}
selrecord(p, &tp->t_rsel, wql);
break;
case FWRITE:
if ((tp->t_outq.c_cc <= tp->t_lowat) &&
(tp->t_state & TS_CONNECTED)) {
retval = tp->t_hiwat - tp->t_outq.c_cc;
break;
}
selrecord(p, &tp->t_wsel, wql);
break;
}
out:
if (retval > 0 && needs_selrecord) {
switch (rw) {
case FREAD:
selrecord(p, &tp->t_rsel, wql);
break;
case FWRITE:
selrecord(p, &tp->t_wsel, wql);
break;
}
}
return retval;
}
/*
* This is a wrapper for compatibility with the select vector used by
* cdevsw. It relies on a proper xxxdevtotty routine.
*
* Locks: Assumes tty_lock() is not held prior to calling.
*/
int
ttselect(dev_t dev, int rw, void *wql, proc_t p)
{
int rv;
struct tty *tp = cdevsw[major(dev)].d_ttys[minor(dev)];
tty_lock(tp);
rv = ttyselect(tp, rw, wql, p);
tty_unlock(tp);
return rv;
}
/*
* Locks: Assumes tp is locked on entry, remains locked on exit
*/
__private_extern__ int
ttnread(struct tty *tp)
{
int nread;
TTY_LOCK_OWNED(tp); /* debug assert */
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;
}
/*
* ttywait
*
* Wait for output to drain.
*
* Parameters: tp Tty on which to wait for output to drain
*
* Returns: 0 Success
* EIO t_timeout too small/expired
* ttysleep:ERESTART Upper layer must redrive the call;
* this is usually done by the Libc
* stub in user space
* ttysleep:EINTR Interrupted (usually a signal)
*
* Notes: Called from proc_exit() and vproc_exit().
*
* Locks: Assumes tp is locked on entry, remains locked on exit
*/
int
ttywait(struct tty *tp)
{
int error;
TTY_LOCK_OWNED(tp); /* debug assert */
error = 0;
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;
}
return error;
}
/*
* Stop the underlying device driver.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
static void
ttystop(struct tty *tp, int rw)
{
TTY_LOCK_OWNED(tp); /* debug assert */
(*cdevsw[major(tp->t_dev)].d_stop)(tp, rw);
}
/*
* Flush if successfully wait.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
static int
ttywflush(struct tty *tp)
{
int error;
TTY_LOCK_OWNED(tp); /* debug assert */
if ((error = ttywait(tp)) == 0) {
ttyflush(tp, FREAD);
}
return error;
}
/*
* Flush tty read and/or write queues, notifying anyone waiting.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
void
ttyflush(struct tty *tp, int rw)
{
TTY_LOCK_OWNED(tp); /* debug assert */
#if 0
again:
#endif
if (rw & FWRITE) {
FLUSHQ(&tp->t_outq);
CLR(tp->t_state, TS_TTSTOP);
}
ttystop(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);
}
}
/*
* Copy in the default termios characters.
*
* Locks: Assumes tty_lock() is held prior to calling.
*
* Notes: No assertion; tp is not in scope.
*/
void
termioschars(struct termios *t)
{
bcopy(ttydefchars, t->c_cc, sizeof t->c_cc);
}
/*
* 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.
*
* Locks: Assumes tty_lock() is held for the call.
*/
void
ttyblock(struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
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.
*
* Locks: Assumes tty_lock() is held for the call.
*/
static void
ttyunblock(struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
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);
}
/*
* ttstart
*
* Start tty output
*
* Parameters: tp tty on which to start output
*
* Returns: 0 Success
*
* Locks: Assumes tty_lock() is held for the call.
*
* Notes: This function might as well be void; it always returns success
*
* Called from ttioctl_locked(), LDISC routines, and
* ttycheckoutq(), ttyblock(), ttyunblock(), and tputchar()
*/
int
ttstart(struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
if (tp->t_oproc != NULL) { /* XXX: Kludge for pty. */
(*tp->t_oproc)(tp);
}
return 0;
}
/*
* ttylclose (LDISC)
*
* "close" a line discipline
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttylclose(struct tty *tp, int flag)
{
TTY_LOCK_OWNED(tp); /* debug assert */
if ((flag & FNONBLOCK) || ttywflush(tp)) {
ttyflush(tp, FREAD | FWRITE);
}
return 0;
}
/*
* ttymodem (LDISC)
*
* Handle modem control transition on a tty.
* Flag indicates new state of carrier.
* Returns 0 if the line should be turned off, otherwise 1.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttymodem(struct tty *tp, int flag)
{
int rval = 1; /* default return value */
TTY_LOCK_OWNED(tp); /* debug assert */
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);
ttystop(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 && tp->t_session->s_leader) {
psignal(tp->t_session->s_leader, SIGHUP);
}
ttyflush(tp, FREAD | FWRITE);
rval = 0;
goto out;
}
} 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);
}
out:
return rval;
}
/*
* Reinput pending characters after state switch
* call at spltty().
*
* Locks: Assumes tty_lock() is held for the call.
*/
static void
ttypend(struct tty *tp)
{
struct clist tq;
int c;
TTY_LOCK_OWNED(tp); /* debug assert */
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 = NULL;
while ((c = getc(&tq)) >= 0) {
ttyinput(c, tp);
}
CLR(tp->t_state, TS_TYPEN);
}
/*
* ttread (LDISC)
*
* Process a read call on a tty device.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttread(struct tty *tp, struct uio *uio, int flag)
{
struct clist *qp;
int c;
tcflag_t lflag;
cc_t *cc = tp->t_cc;
proc_t p = current_proc();
int first, error = 0;
int has_etime = 0, last_cc = 0;
long slp = 0; /* XXX this should be renamed `timo'. */
struct uthread *ut;
struct pgrp * pg;
TTY_LOCK_OWNED(tp); /* debug assert */
ut = (struct uthread *)get_bsdthread_info(current_thread());
loop:
lflag = tp->t_lflag;
/*
* take pending input first
*/
if (ISSET(lflag, PENDIN)) {
ttypend(tp);
lflag = tp->t_lflag; /* XXX ttypend() clobbers it */
}
/*
* Signal the process if it's in the background. If the terminal is
* getting revoked, everybody is in the background.
*/
if (isbackground(p, tp) || ISSET(tp->t_state, TS_REVOKE)) {
if ((p->p_sigignore & sigmask(SIGTTIN)) ||
(ut->uu_sigmask & sigmask(SIGTTIN)) ||
p->p_lflag & P_LPPWAIT) {
error = EIO;
goto err;
}
pg = proc_pgrp(p);
if (pg == PGRP_NULL) {
error = EIO;
goto err;
}
if (pg->pg_jobc == 0) {
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
pg_rele(pg);
tty_lock(tp);
error = EIO;
goto err;
}
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
pgsignal(pg, SIGTTIN, 1);
pg_rele(pg);
tty_lock(tp);
/*
* We signalled ourself, so we need to act as if we
* have been "interrupted" from a "sleep" to act on
* the signal. If it's a signal that stops the
* process, that's handled in the signal sending code.
*/
error = EINTR;
goto err;
}
if (ISSET(tp->t_state, TS_ZOMBIE)) {
/* EOF - returning 0 */
goto err;
}
/*
* 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) {
error = EWOULDBLOCK;
}
/* else polling - returning 0 */
goto err;
}
if (!ISSET(lflag, ICANON)) {
int m = cc[VMIN];
long t = cc[VTIME];
struct timeval timecopy;
struct timeval etime = {.tv_sec = 0, .tv_usec = 0}; /* protected by !has_etime */
/*
* 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. */
goto err;
}
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;
}
microuptime(&timecopy);
if (!has_etime || qp->c_cc > last_cc) {
/* first character or got a character, start timer */
has_etime = 1;
etime.tv_sec = t / 1000000;
etime.tv_usec =
(__darwin_suseconds_t)(t - (etime.tv_sec * 1000000));
timeradd(&etime, &timecopy, &etime);
slp = t;
} else {
/* nothing, check expiration */
if (timercmp(&etime, &timecopy, <=)) {
goto read;
}
slp = diff(etime, timecopy);
}
last_cc = qp->c_cc;
} else { /* m == 0 */
if (qp->c_cc > 0) {
goto read;
}
microuptime(&timecopy);
if (!has_etime) {
has_etime = 1;
etime.tv_sec = t / 1000000;
etime.tv_usec =
(__darwin_suseconds_t)(t - (etime.tv_sec * 1000000));
timeradd(&etime, &timecopy, &etime);
slp = t;
} else {
if (timercmp(&etime, &timecopy, <=)) {
/* Timed out, but 0 is enough input. */
goto err;
}
slp = diff(etime, timecopy);
}
}
#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 hzto() for how to avoid overflow if hz
* is large (divide by `tick' and/or arrange to
* use hzto() if hz is large).
*/
slp = (long) (((u_int32_t)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);
if (error == EWOULDBLOCK) {
error = 0;
} else if (error) {
goto err;
}
/*
* 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:
/*
* Input present, check for input mapping and processing.
*/
first = 1;
if (ISSET(lflag, ICANON)
|| (ISSET(lflag, IEXTEN | ISIG) == (IEXTEN | ISIG))) {
goto slowcase;
}
for (;;) {
char ibuf[IBUFSIZ];
int icc;
ssize_t size = uio_resid(uio);
if (size < 0) {
error = ERANGE;
break;
}
icc = (int)MIN(size, IBUFSIZ);
icc = q_to_b(qp, (u_char *)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_resid(uio) == 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)) {
/*
* SAFE: All callers drop the lock on return and
* SAFE: current thread will not change out from
* SAFE: under us in the "goto loop" case.
*/
tty_unlock(tp);
tty_pgsignal(tp, SIGTSTP, 1);
tty_lock(tp);
if (first) {
error = ttysleep(tp, &ttread, TTIPRI | PCATCH,
"ttybg3", hz);
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_resid(uio) == 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.
*/
if (ISSET(tp->t_state, TS_TBLOCK) &&
tp->t_rawq.c_cc + tp->t_canq.c_cc <= I_LOW_WATER) {
ttyunblock(tp);
}
err:
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.
*
* Locks: Assumes tty_lock() is held before calling
*
* Notes: This function is called from tprintf() in subr_prf.c
*/
int
ttycheckoutq(struct tty *tp, int wait)
{
int hiwat;
sigset_t oldsig;
struct uthread *ut;
TTY_LOCK_OWNED(tp); /* debug assert */
ut = (struct uthread *)get_bsdthread_info(current_thread());
hiwat = tp->t_hiwat;
oldsig = wait ? ut->uu_siglist : 0;
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 == 0 || ut->uu_siglist != oldsig) {
return 0;
}
SET(tp->t_state, TS_SO_OLOWAT);
ttysleep(tp, TSA_OLOWAT(tp), PZERO - 1, "ttoutq", hz);
}
}
return 1;
}
/*
* ttwrite (LDISC)
*
* Process a write call on a tty device.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
ttwrite(struct tty *tp, struct uio *uio, int flag)
{
char *cp = NULL;
int cc, ce;
proc_t p;
int i, hiwat, error;
user_ssize_t count;
char obuf[OBUFSIZ];
struct uthread *ut;
struct pgrp * pg;
TTY_LOCK_OWNED(tp); /* debug assert */
ut = (struct uthread *)get_bsdthread_info(current_thread());
hiwat = tp->t_hiwat;
count = uio_resid(uio);
error = 0;
cc = 0;
loop:
if (ISSET(tp->t_state, TS_ZOMBIE)) {
if (uio_resid(uio) == count) {
error = EIO;
}
goto out;
}
if (!ISSET(tp->t_state, TS_CONNECTED)) {
if (flag & IO_NDELAY) {
error = EWOULDBLOCK;
goto out;
}
error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
"ttydcd", 0);
if (error) {
goto out;
}
goto loop;
}
/*
* Signal the process if it's in the background.
*/
p = current_proc();
if (isbackground(p, tp) &&
ISSET(tp->t_lflag, TOSTOP) && (p->p_lflag & P_LPPWAIT) == 0 &&
(p->p_sigignore & sigmask(SIGTTOU)) == 0 &&
(ut->uu_sigmask & sigmask(SIGTTOU)) == 0) {
pg = proc_pgrp(p);
if (pg == PGRP_NULL) {
error = EIO;
goto out;
}
if (pg->pg_jobc == 0) {
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
pg_rele(pg);
tty_lock(tp);
error = EIO;
goto out;
}
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
pgsignal(pg, SIGTTOU, 1);
pg_rele(pg);
tty_lock(tp);
/*
* We signalled ourself, so we need to act as if we
* have been "interrupted" from a "sleep" to act on
* the signal. If it's a signal that stops the
* process, that's handled in the signal sending code.
*/
error = EINTR;
goto out;
}
/*
* 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_resid(uio) > 0 || cc > 0) {
if (ISSET(tp->t_lflag, FLUSHO)) {
uio_setresid(uio, 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) {
ssize_t size = uio_resid(uio);
if (size < 0) {
error = ERANGE;
break;
}
cc = (int)MIN((size_t)size, 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 = (int)((size_t)cc - scanc((size_t)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) {
/* out of space */
goto overfull;
}
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((u_char *)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 */
goto overfull;
}
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_setresid(uio, (uio_resid(uio) + 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);
/*
* 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) {
goto loop;
}
if (flag & IO_NDELAY) {
uio_setresid(uio, (uio_resid(uio) + cc));
return uio_resid(uio) == count ? EWOULDBLOCK : 0;
}
SET(tp->t_state, TS_SO_OLOWAT);
error = ttysleep(tp, TSA_OLOWAT(tp), TTOPRI | PCATCH, "ttywri",
tp->t_timeout);
if (error == EWOULDBLOCK) {
error = EIO;
}
if (error) {
goto out;
}
goto loop;
}
/*
* Rubout one character from the rawq of tp
* as cleanly as possible.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
static void
ttyrub(int c, struct tty *tp)
{
u_char *cp;
int savecol;
int tabc;
TTY_LOCK_OWNED(tp); /* debug assert */
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) {
/*
* Messed up 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:
if (!(ISSET(tp->t_iflag, IUTF8) && CCONT(c))) {
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;
}
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);
/* savecol will now be length of the tab. */
savecol -= tp->t_column;
tp->t_column += savecol;
if (savecol > 8) {
savecol = 8; /* overflow fixup */
}
while (--savecol >= 0) {
(void)ttyoutput('\b', tp);
}
break;
default: /* XXX */
#define PANICSTR "ttyrub: would panic c = %d, val = %d\n"
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);
}
--tp->t_rocount;
}
/*
* Back over count characters, erasing them.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
static void
ttyrubo(struct tty *tp, int count)
{
TTY_LOCK_OWNED(tp); /* debug assert */
while (count-- > 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.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
static void
ttyretype(struct tty *tp)
{
u_char *cp;
int c;
TTY_LOCK_OWNED(tp); /* debug assert */
/* Echo the reprint character. */
if (tp->t_cc[VREPRINT] != _POSIX_VDISABLE) {
ttyecho(tp->t_cc[VREPRINT], tp);
}
(void)ttyoutput('\n', tp);
/*
* FREEBSD XXX
* FIX: NEXTC IS BROKEN - DOESN'T CHECK QUOTE
* BIT OF FIRST CHAR.
*/
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);
tp->t_rocount = tp->t_rawq.c_cc;
tp->t_rocol = 0;
}
/*
* Echo a typed character to the terminal.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
static void
ttyecho(int c, struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
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);
}
static void
ttwakeup_knote(struct selinfo *sip, long hint)
{
if ((sip->si_flags & SI_KNPOSTING) == 0) {
sip->si_flags |= SI_KNPOSTING;
KNOTE(&sip->si_note, hint);
sip->si_flags &= ~SI_KNPOSTING;
}
}
/*
* Wake up any readers on a tty.
*
* Locks: Assumes tty_lock() is held for the call.
*/
void
ttwakeup(struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
selwakeup(&tp->t_rsel);
ttwakeup_knote(&tp->t_rsel, 0);
if (ISSET(tp->t_state, TS_ASYNC)) {
/*
* XXX: Callers may not revalidate it the tty is closed
* XXX: out from under them by another thread, but we do
* XXX: not support queued signals. This should be safe,
* XXX: since the process we intend to wakeup is in the
* XXX: process group, and will wake up because of the
* XXX: signal anyway.
*/
tty_unlock(tp);
tty_pgsignal(tp, SIGIO, 1);
tty_lock(tp);
}
wakeup(TSA_HUP_OR_INPUT(tp));
}
/*
* ttwwakeup (LDISC)
*
* Wake up any writers on a tty.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
void
ttwwakeup(struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
if (tp->t_outq.c_cc <= tp->t_lowat) {
selwakeup(&tp->t_wsel);
ttwakeup_knote(&tp->t_wsel, 0);
}
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_lowat) {
CLR(tp->t_state, TS_SO_OLOWAT);
wakeup(TSA_OLOWAT(tp));
}
}
/*
* Look up a code for a specified speed in a conversion table;
* used by drivers to map software speed values to hardware parameters.
*
* Notes: No locks are assumed for this function; it does not
* directly access struct tty.
*/
int
ttspeedtab(int speed, 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.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
void
ttsetwater(struct tty *tp)
{
speed_t cps;
unsigned int x;
TTY_LOCK_OWNED(tp); /* debug assert */
#define CLAMP(x, h, l) ((x) > h ? h : ((x) < l) ? l : (x))
cps = tp->t_ospeed / 10;
static_assert(TTMAXLOWAT <= UINT_MAX, "max low water fits in unsigned int");
static_assert(TTMINLOWAT <= UINT_MAX, "min low water fits in unsigned int");
tp->t_lowat = x = (unsigned int)CLAMP(cps / 2, TTMAXLOWAT, TTMINLOWAT);
x += cps;
x = CLAMP(x, TTMAXHIWAT, TTMINHIWAT);
tp->t_hiwat = roundup(x, CBSIZE);
#undef CLAMP
}
/* ttyinfo has been converted to the MACH kernel */
#include <mach/thread_info.h>
/* XXX Should be in Mach header <kern/thread.h>, but doesn't work */
extern kern_return_t thread_info_internal(thread_t thread,
thread_flavor_t flavor,
thread_info_t thread_info_out,
mach_msg_type_number_t *thread_info_count);
/*
* Report on state of foreground process group.
*
* Locks: Assumes tty_lock() is held prior to calling.
*/
void
ttyinfo_locked(struct tty *tp)
{
int load;
thread_t thread;
uthread_t uthread;
proc_t p;
proc_t pick;
pid_t pickpid;
const char *state;
struct timeval utime;
struct timeval stime;
thread_basic_info_data_t basic_info;
mach_msg_type_number_t mmtn = THREAD_BASIC_INFO_COUNT;
struct pgrp * pg;
TTY_LOCK_OWNED(tp); /* debug assert */
if (ttycheckoutq(tp, 0) == 0) {
return;
}
/* Print load average. */
load = (averunnable.ldavg[0] * 100 + FSCALE / 2) >> FSHIFT;
ttyprintf(tp, "load: %d.%02d ", load / 100, load % 100);
/*
* On return following a ttyprintf(), we set tp->t_rocount to 0 so
* that pending input will be retyped on BS.
*/
if (tp->t_session == NULL) {
ttyprintf(tp, "not a controlling terminal\n");
tp->t_rocount = 0;
return;
}
if (tp->t_pgrp == NULL) {
ttyprintf(tp, "no foreground process group\n");
tp->t_rocount = 0;
return;
}
/* first process in process group */
/* XXX is there a need for pgrp lock ? */
if ((p = tp->t_pgrp->pg_members.lh_first) == NULL) {
ttyprintf(tp, "empty foreground process group\n");
tp->t_rocount = 0;
return;
}
/*
* Pick the most interesting process and copy some of its
* state for printing later.
*/
pg = proc_pgrp(p);
pgrp_lock(pg);
/* the proc_compare is non blocking fn, no need to use iterator */
for (pick = NULL; p != NULL; p = p->p_pglist.le_next) {
if (proc_compare(pick, p)) {
pick = p;
pickpid = p->p_pid;
} else {
pickpid = pick->p_pid;
}
}
pgrp_unlock(pg);
/* SAFE: All callers drop the lock on return */
tty_unlock(tp);
pg_rele(pg);
tty_lock(tp);
pick = proc_find(pickpid);
if (pick == PROC_NULL) {
return;
}
if (TAILQ_EMPTY(&pick->p_uthlist) ||
(uthread = TAILQ_FIRST(&pick->p_uthlist)) == NULL ||
(thread = vfs_context_thread(&uthread->uu_context)) == NULL ||
(thread_info_internal(thread, THREAD_BASIC_INFO, (thread_info_t)&basic_info, &mmtn) != KERN_SUCCESS)) {
ttyprintf(tp, "foreground process without thread\n");
tp->t_rocount = 0;
proc_rele(pick);
return;
}
switch (basic_info.run_state) {
case TH_STATE_RUNNING:
state = "running";
break;
case TH_STATE_STOPPED:
state = "stopped";
break;
case TH_STATE_WAITING:
state = "waiting";
break;
case TH_STATE_UNINTERRUPTIBLE:
state = "uninterruptible";
break;
case TH_STATE_HALTED:
state = "halted";
break;
default:
state = "unknown";
break;
}
calcru(pick, &utime, &stime, NULL);
/* Print command, pid, state, utime, and stime */
ttyprintf(tp, " cmd: %s %d %s %ld.%02du %ld.%02ds\n",
pick->p_comm,
pick->p_pid,
state,
(long)utime.tv_sec, utime.tv_usec / 10000,
(long)stime.tv_sec, stime.tv_usec / 10000);
proc_rele(pick);
tp->t_rocount = 0;
}
/*
* 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.
* 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
/*
* Locks: pgrp_lock(p2) held on call to this function
* tty_lock(tp) for p2's tty, for which p2 is the foreground
* process, held on call to this function
*/
static int
proc_compare(proc_t p1, proc_t p2)
{
/* NOTE THIS FN needs to be NON BLOCKING */
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
*/
#ifdef _PROC_HAS_SCHEDINFO_
/* Without the support the fields are always zero */
if (p2->p_estcpu > p1->p_estcpu) {
return 1;
}
if (p1->p_estcpu > p2->p_estcpu) {
return 0;
}
#endif /* _PROC_HAS_SCHEDINFO_ */
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 */
}
/*
* pick the one with the smallest sleep time
*/
#ifdef _PROC_HAS_SCHEDINFO_
/* Without the support the fields are always zero */
if (p2->p_slptime > p1->p_slptime) {
return 0;
}
if (p1->p_slptime > p2->p_slptime) {
return 1;
}
#endif /* _PROC_HAS_SCHEDINFO_ */
return p2->p_pid > p1->p_pid; /* tie - return highest pid */
}
/*
* Output char to tty; console putchar style.
*
* Locks: Assumes tty_lock() is held prior to calling.
*
* Notes: Only ever called from putchar() in subr_prf.c
*/
int
tputchar(int c, struct tty *tp)
{
TTY_LOCK_OWNED(tp); /* debug assert */
if (!ISSET(tp->t_state, TS_CONNECTED)) {
return -1;
}
if (c == '\n') {
(void)ttyoutput('\r', tp);
}
(void)ttyoutput(c, tp);
ttstart(tp);
return 0;
}
/*
* ttysleep
*
* Sleep on a wait channel waiting for an interrupt or a condition to come
* true so that we are woken up.
*
* Parameters: tp Tty going to sleep
* chan The sleep channel (usually an address
* of a structure member)
* pri priority and flags
* wmesg Wait message; shows up in debugger,
* should show up in "ps", but doesn't
* timo Timeout for the sleep
*
* Returns: 0 Condition came true
* ERESTART Upper layer must redrive the call;
* this is usually done by the Libc
* stub in user space
* msleep0:EINTR Interrupted (usually a signal)
* msleep0:ERESTART Interrupted (usually a masked signal)
* msleep0:EWOULDBLOCK Timeout (timo) already expired
*
* Locks: Assumes tty_lock() is held prior to calling.
*
* Sleep on chan, returning ERESTART if tty changed while we napped and
* returning any errors (e.g. EINTR/EWOULDBLOCK) reported by msleep0. If
* the tty is revoked, restarting a pending call will redo validation done
* at the start of the call.
*/
int
ttysleep(struct tty *tp, void *chan, int pri, const char *wmesg, int timo)
{
int error;
int gen;
TTY_LOCK_OWNED(tp);
if (tp->t_state & TS_REVOKE) {
return ERESTART;
}
gen = tp->t_gen;
/* Use of msleep0() avoids conversion timo/timespec/timo */
error = msleep0(chan, &tp->t_lock, pri, wmesg, timo, (int (*)(int))0);
if (error) {
return error;
}
return tp->t_gen == gen ? 0 : ERESTART;
}
/*
* Allocate a tty structure and its associated buffers.
*
* Parameters: void
*
* Returns: !NULL Address of new struct tty
* NULL Error ("ENOMEM")
*
* Locks: The tty_lock() of the returned tty is not held when it
* is returned.
*/
struct tty *
ttymalloc(void)
{
struct tty *tp;
tp = kheap_alloc(KM_TTYS, sizeof(struct tty), Z_WAITOK | Z_ZERO);
if (tp != NULL) {
/* XXX: default to TTYCLSIZE(1024) chars for now */
clalloc(&tp->t_rawq, TTYCLSIZE, 1);
clalloc(&tp->t_canq, TTYCLSIZE, 1);
/* output queue doesn't need quoting */
clalloc(&tp->t_outq, TTYCLSIZE, 0);
lck_mtx_init(&tp->t_lock, &tty_lck_grp, LCK_ATTR_NULL);
klist_init(&tp->t_rsel.si_note);
klist_init(&tp->t_wsel.si_note);
tp->t_refcnt = 1;
}
return tp;
}
/*
* Increment the reference count on a tty.
*/
void
ttyhold(struct tty *tp)
{
TTY_LOCK_OWNED(tp);
tp->t_refcnt++;
}
/*
* Drops a reference count on a tty structure; if the reference count reaches
* zero, then also frees the structure and associated buffers.
*/
void
ttyfree(struct tty *tp)
{
TTY_LOCK_NOTOWNED(tp);
tty_lock(tp);
if (--tp->t_refcnt == 0) {
tty_unlock(tp);
ttydeallocate(tp);
} else if (tp->t_refcnt < 0) {
panic("%s: freeing free tty %p", __func__, tp);
} else {
tty_unlock(tp);
}
}
/*
* Deallocate a tty structure and its buffers.
*
* Locks: The tty_lock() is assumed to not be held at the time of
* the free; this function destroys the mutex.
*/
static void
ttydeallocate(struct tty *tp)
{
TTY_LOCK_NOTOWNED(tp); /* debug assert */
#if DEBUG
if (!(SLIST_EMPTY(&tp->t_rsel.si_note) && SLIST_EMPTY(&tp->t_wsel.si_note))) {
panic("knotes hooked into a tty when the tty is freed.\n");
}
#endif /* DEBUG */
clfree(&tp->t_rawq);
clfree(&tp->t_canq);
clfree(&tp->t_outq);
lck_mtx_destroy(&tp->t_lock, &tty_lck_grp);
kheap_free(KM_TTYS, tp, sizeof(struct tty));
}
/*
* Locks: Assumes tty_lock() is held prior to calling.
*/
int
isbackground(proc_t p, struct tty *tp)
{
TTY_LOCK_OWNED(tp);
return tp->t_session != NULL && p->p_pgrp != NULL && (p->p_pgrp != tp->t_pgrp) && isctty_sp(p, tp, p->p_pgrp->pg_session);
}
static int
isctty(proc_t p, struct tty *tp)
{
int retval;
struct session * sessp;
sessp = proc_session(p);
retval = (sessp == tp->t_session && p->p_flag & P_CONTROLT);
session_rele(sessp);
return retval;
}
static int
isctty_sp(proc_t p, struct tty *tp, struct session *sessp)
{
return sessp == tp->t_session && p->p_flag & P_CONTROLT;
}
static int filt_ttyattach(struct knote *kn, struct kevent_qos_s *kev);
static void filt_ttydetach(struct knote *kn);
static int filt_ttyevent(struct knote *kn, long hint);
static int filt_ttytouch(struct knote *kn, struct kevent_qos_s *kev);
static int filt_ttyprocess(struct knote *kn, struct kevent_qos_s *kev);
SECURITY_READ_ONLY_EARLY(struct filterops) tty_filtops = {
.f_isfd = 1,
.f_attach = filt_ttyattach,
.f_detach = filt_ttydetach,
.f_event = filt_ttyevent,
.f_touch = filt_ttytouch,
.f_process = filt_ttyprocess
};
/*
* Called with struct tty locked. Returns non-zero if there is data to be read
* or written.
*/
static int
filt_tty_common(struct knote *kn, struct kevent_qos_s *kev, struct tty *tp)
{
int retval = 0;
int64_t data = 0;
TTY_LOCK_OWNED(tp); /* debug assert */
switch (kn->kn_filter) {
case EVFILT_READ:
/*
* ttnread can change the tty state,
* hence must be done upfront, before any other check.
*/
data = ttnread(tp);
retval = (data != 0);
break;
case EVFILT_WRITE:
if ((tp->t_outq.c_cc <= tp->t_lowat) &&
(tp->t_state & TS_CONNECTED)) {
data = tp->t_hiwat - tp->t_outq.c_cc;
retval = (data != 0);
}
break;
default:
panic("tty kevent: unexpected filter: %d, kn = %p, tty = %p",
kn->kn_filter, kn, tp);
break;
}
/*
* TODO(mwidmann, jandrus): For native knote low watermark support,
* check the kn_sfflags for NOTE_LOWAT and check against kn_sdata.
*
* res = ((kn->kn_sfflags & NOTE_LOWAT) != 0) ?
* (kn->kn_data >= kn->kn_sdata) : kn->kn_data;
*/
if (tp->t_state & TS_ZOMBIE) {
kn->kn_flags |= EV_EOF;
}
if (kn->kn_flags & EV_EOF) {
retval = 1;
}
if (retval && kev) {
knote_fill_kevent(kn, kev, data);
}
return retval;
}
/*
* Find the struct tty from a waitq, which is a member of one of the two struct
* selinfos inside the struct tty. Use the seltype to determine which selinfo.
*/
static struct tty *
tty_from_waitq(struct waitq *wq, int seltype)
{
struct selinfo *si;
struct tty *tp = NULL;
/*
* The waitq is part of the selinfo structure managed by the driver. For
* certain drivers, we want to hook the knote into the selinfo
* structure's si_note field so selwakeup can call KNOTE.
*
* While 'wq' is not really a queue element, this macro only uses the
* pointer to calculate the offset into a structure given an element
* name.
*/
si = qe_element(wq, struct selinfo, si_waitq);
/*
* For TTY drivers, the selinfo structure is somewhere in the struct
* tty. There are two different selinfo structures, and the one used
* corresponds to the type of filter requested.
*
* While 'si' is not really a queue element, this macro only uses the
* pointer to calculate the offset into a structure given an element
* name.
*/
switch (seltype) {
case FREAD:
tp = qe_element(si, struct tty, t_rsel);
break;
case FWRITE:
tp = qe_element(si, struct tty, t_wsel);
break;
}
return tp;
}
static struct tty *
tty_from_knote(struct knote *kn)
{
return (struct tty *)kn->kn_hook;
}
/*
* Set the knote's struct tty to the kn_hook field.
*
* The idea is to fake a call to select with our own waitq set. If the driver
* calls selrecord, we'll get a link to their waitq and access to the tty
* structure.
*
* Returns -1 on failure, with the error set in the knote, or selres on success.
*/
static int
tty_set_knote_hook(struct knote *kn)
{
uthread_t uth;
vfs_context_t ctx;
vnode_t vp;
kern_return_t kr;
struct waitq *wq = NULL;
struct waitq_set *old_wqs;
struct waitq_set tmp_wqs;
uint64_t rsvd, rsvd_arg;
uint64_t *rlptr = NULL;
int selres = -1;
struct tty *tp;
uth = get_bsdthread_info(current_thread());
ctx = vfs_context_current();
vp = (vnode_t)kn->kn_fp->fp_glob->fg_data;
/*
* Reserve a link element to avoid potential allocation under
* a spinlock.
*/
rsvd = rsvd_arg = waitq_link_reserve(NULL);
rlptr = (void *)&rsvd_arg;
/*
* Trick selrecord into hooking a known waitq set into the device's selinfo
* waitq. Once the link is in place, we can get back into the selinfo from
* the waitq and subsequently the tty (see tty_from_waitq).
*
* We can't use a real waitq set (such as the kqueue's) because wakeups
* might happen before we can unlink it.
*/
kr = waitq_set_init(&tmp_wqs, SYNC_POLICY_FIFO | SYNC_POLICY_PREPOST, NULL,
NULL);
assert(kr == KERN_SUCCESS);
/*
* Lazy allocate the waitqset to avoid potential allocation under
* a spinlock;
*/
waitq_set_lazy_init_link(&tmp_wqs);
old_wqs = uth->uu_wqset;
uth->uu_wqset = &tmp_wqs;
/*
* FMARK forces selects to always call selrecord, even if data is
* available. See ttselect, ptsselect, ptcselect.
*
* selres also contains the data currently available in the tty.
*/
selres = VNOP_SELECT(vp, knote_get_seltype(kn) | FMARK, 0, rlptr, ctx);
uth->uu_wqset = old_wqs;
/*
* Make sure to cleanup the reserved link - this guards against
* drivers that may not actually call selrecord().
*/
waitq_link_release(rsvd);
if (rsvd == rsvd_arg) {
/*
* The driver didn't call selrecord -- there's no tty hooked up so we
* can't attach.
*/
knote_set_error(kn, ENOTTY);
selres = -1;
goto out;
}
/* rlptr may not point to a properly aligned pointer */
memcpy(&wq, rlptr, sizeof(void *));
tp = tty_from_waitq(wq, knote_get_seltype(kn));
assert(tp != NULL);
/*
* Take a reference and stash the tty in the knote.
*/
tty_lock(tp);
ttyhold(tp);
kn->kn_hook = tp;
tty_unlock(tp);
out:
/*
* Cleaning up the wqset will unlink its waitq and clean up any preposts
* that occurred as a result of data coming in while the tty was attached.
*/
waitq_set_deinit(&tmp_wqs);
return selres;
}
static int
filt_ttyattach(struct knote *kn, __unused struct kevent_qos_s *kev)
{
int selres = 0;
struct tty *tp;
/*
* This function should be called from filt_specattach (spec_vnops.c),
* so most of the knote data structure should already be initialized.
*/
/* don't support offsets in ttys or drivers that don't use struct tty */
if (kn->kn_vnode_use_ofst || !kn->kn_vnode_kqok) {
knote_set_error(kn, ENOTSUP);
return 0;
}
/*
* Connect the struct tty to the knote through the selinfo structure
* referenced by the waitq within the selinfo.
*/
selres = tty_set_knote_hook(kn);
if (selres < 0) {
return 0;
}
/*
* Attach the knote to selinfo's klist.
*/
tp = tty_from_knote(kn);
tty_lock(tp);
switch (kn->kn_filter) {
case EVFILT_READ:
KNOTE_ATTACH(&tp->t_rsel.si_note, kn);
break;
case EVFILT_WRITE:
KNOTE_ATTACH(&tp->t_wsel.si_note, kn);
break;
default:
panic("invalid knote %p attach, filter: %d", kn, kn->kn_filter);
}
tty_unlock(tp);
return selres;
}
static void
filt_ttydetach(struct knote *kn)
{
struct tty *tp = tty_from_knote(kn);
tty_lock(tp);
switch (kn->kn_filter) {
case EVFILT_READ:
KNOTE_DETACH(&tp->t_rsel.si_note, kn);
break;
case EVFILT_WRITE:
KNOTE_DETACH(&tp->t_wsel.si_note, kn);
break;
default:
panic("invalid knote %p detach, filter: %d", kn, kn->kn_filter);
break;
}
tty_unlock(tp);
ttyfree(tp);
}
static int
filt_ttyevent(struct knote *kn, long hint)
{
struct tty *tp = tty_from_knote(kn);
int ret;
TTY_LOCK_OWNED(tp);
if (hint & NOTE_REVOKE) {
kn->kn_flags |= EV_EOF | EV_ONESHOT;
ret = 1;
} else {
ret = filt_tty_common(kn, NULL, tp);
}
return ret;
}
static int
filt_ttytouch(struct knote *kn, struct kevent_qos_s *kev)
{
struct tty *tp = tty_from_knote(kn);
int res = 0;
tty_lock(tp);
kn->kn_sdata = kev->data;
kn->kn_sfflags = kev->fflags;
if (kn->kn_vnode_kqok) {
res = filt_tty_common(kn, NULL, tp);
}
tty_unlock(tp);
return res;
}
static int
filt_ttyprocess(struct knote *kn, struct kevent_qos_s *kev)
{
struct tty *tp = tty_from_knote(kn);
int res;
tty_lock(tp);
res = filt_tty_common(kn, kev, tp);
tty_unlock(tp);
return res;
}
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