newlib-cygwin/winsup/cygwin/fhandler_termios.cc

537 lines
13 KiB
C++

/* fhandler_termios.cc
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <stdlib.h>
#include <ctype.h>
#include "cygerrno.h"
#include "path.h"
#include "fhandler.h"
#include "sigproc.h"
#include "pinfo.h"
#include "tty.h"
#include "cygtls.h"
#include "dtable.h"
#include "cygheap.h"
#include "child_info.h"
#include "ntdll.h"
/* Common functions shared by tty/console */
void
fhandler_termios::tcinit (bool is_pty_master)
{
/* Initial termios values */
if (is_pty_master || !tc ()->initialized ())
{
tc ()->ti.c_iflag = BRKINT | ICRNL | IXON | IUTF8;
tc ()->ti.c_oflag = OPOST | ONLCR;
tc ()->ti.c_cflag = B38400 | CS8 | CREAD;
tc ()->ti.c_lflag = ISIG | ICANON | ECHO | IEXTEN
| ECHOE | ECHOK | ECHOCTL | ECHOKE;
tc ()->ti.c_cc[VDISCARD] = CFLUSH;
tc ()->ti.c_cc[VEOL] = CEOL;
tc ()->ti.c_cc[VEOL2] = CEOL2;
tc ()->ti.c_cc[VEOF] = CEOF;
tc ()->ti.c_cc[VERASE] = CERASE;
tc ()->ti.c_cc[VINTR] = CINTR;
tc ()->ti.c_cc[VKILL] = CKILL;
tc ()->ti.c_cc[VLNEXT] = CLNEXT;
tc ()->ti.c_cc[VMIN] = CMIN;
tc ()->ti.c_cc[VQUIT] = CQUIT;
tc ()->ti.c_cc[VREPRINT] = CRPRNT;
tc ()->ti.c_cc[VSTART] = CSTART;
tc ()->ti.c_cc[VSTOP] = CSTOP;
tc ()->ti.c_cc[VSUSP] = CSUSP;
tc ()->ti.c_cc[VSWTC] = CSWTCH;
tc ()->ti.c_cc[VTIME] = CTIME;
tc ()->ti.c_cc[VWERASE] = CWERASE;
tc ()->ti.c_ispeed = tc ()->ti.c_ospeed = B38400;
tc ()->pgid = is_pty_master ? 0 : myself->pgid;
tc ()->initialized (true);
}
}
int
fhandler_termios::tcsetpgrp (const pid_t pgid)
{
termios_printf ("%s, pgid %d, sid %d, tsid %d", tc ()->ttyname (), pgid,
myself->sid, tc ()->getsid ());
if (myself->sid != tc ()->getsid ())
{
set_errno (EPERM);
return -1;
}
else if (pgid < 0)
{
set_errno (EINVAL);
return -1;
}
int res;
while (1)
{
res = bg_check (-SIGTTOU);
switch (res)
{
case bg_ok:
tc ()->setpgid (pgid);
if (tc ()->is_console && (strace.active () || !being_debugged ()))
tc ()->kill_pgrp (__SIGSETPGRP);
res = 0;
break;
case bg_signalled:
if (_my_tls.call_signal_handler ())
continue;
set_errno (EINTR);
fallthrough;
default:
res = -1;
break;
}
break;
}
return res;
}
int
fhandler_termios::tcgetpgrp ()
{
if (myself->ctty > 0 && myself->ctty == tc ()->ntty)
return tc ()->pgid;
set_errno (ENOTTY);
return -1;
}
int
fhandler_pty_master::tcgetpgrp ()
{
return tc ()->pgid;
}
static inline bool
is_flush_sig (int sig)
{
return sig == SIGINT || sig == SIGQUIT || sig == SIGTSTP;
}
void
tty_min::kill_pgrp (int sig)
{
bool killself = false;
if (is_flush_sig (sig) && cygheap->ctty)
cygheap->ctty->sigflush ();
winpids pids ((DWORD) PID_MAP_RW);
siginfo_t si = {0};
si.si_signo = sig;
si.si_code = SI_KERNEL;
for (unsigned i = 0; i < pids.npids; i++)
{
_pinfo *p = pids[i];
if (!p || !p->exists () || p->ctty != ntty || p->pgid != pgid)
continue;
if (p == myself)
killself = sig != __SIGSETPGRP && !exit_state;
else
sig_send (p, si);
}
if (killself)
sig_send (myself, si);
}
int
tty_min::is_orphaned_process_group (int pgid)
{
/* An orphaned process group is a process group in which the parent
of every member is either itself a member of the group or is not
a member of the group's session. */
termios_printf ("checking pgid %d, my sid %d, my parent %d", pgid, myself->sid, myself->ppid);
winpids pids ((DWORD) 0);
for (unsigned i = 0; i < pids.npids; i++)
{
_pinfo *p = pids[i];
termios_printf ("checking pid %d - has pgid %d\n", p->pid, p->pgid);
if (!p || !p->exists () || p->pgid != pgid)
continue;
pinfo ppid (p->ppid);
if (!ppid)
continue;
termios_printf ("ppid->pgid %d, ppid->sid %d", ppid->pgid, ppid->sid);
if (ppid->pgid != pgid && ppid->sid == myself->sid)
return 0;
}
return 1;
}
/*
bg_check: check that this process is either in the foreground process group,
or if the terminal operation is allowed for processes which are in a
background process group.
If the operation is not permitted by the terminal configuration for processes
which are a member of a background process group, return an error or raise a
signal as appropriate.
This handles the following terminal operations:
write: sig = SIGTTOU
read: sig = SIGTTIN
change terminal settings: sig = -SIGTTOU
(tcsetattr, tcsetpgrp, etc.)
peek (poll, select): sig = SIGTTIN, dontsignal = TRUE
*/
bg_check_types
fhandler_termios::bg_check (int sig, bool dontsignal)
{
/* Ignore errors:
- this process isn't in a process group
- tty is invalid
Everything is ok if:
- this process is in the foreground process group, or
- this tty is not the controlling tty for this process (???), or
- writing, when TOSTOP TTY mode is not set on this tty
*/
if (!myself->pgid || !tc () || tc ()->getpgid () == myself->pgid ||
myself->ctty != tc ()->ntty ||
((sig == SIGTTOU) && !(tc ()->ti.c_lflag & TOSTOP)))
return bg_ok;
/* sig -SIGTTOU is used to indicate a change to terminal settings, where
TOSTOP TTY mode isn't considered when determining if we need to send a
signal. */
if (sig < 0)
sig = -sig;
termios_printf ("%s, bg I/O pgid %d, tpgid %d, myctty %s", tc ()->ttyname (),
myself->pgid, tc ()->getpgid (), myctty ());
if (tc ()->getsid () == 0)
{
/* The pty has been closed by the master. Return an EOF
indication. FIXME: There is nothing to stop somebody
from reallocating this pty. I think this is the case
which is handled by unlockpt on a Unix system. */
termios_printf ("closed by master");
return bg_eof;
}
threadlist_t *tl_entry;
tl_entry = cygheap->find_tls (_main_tls);
int sigs_ignored =
((void *) global_sigs[sig].sa_handler == (void *) SIG_IGN) ||
(_main_tls->sigmask & SIGTOMASK (sig));
cygheap->unlock_tls (tl_entry);
/* If the process is blocking or ignoring SIGTT*, then signals are not sent
and background IO is allowed */
if (sigs_ignored)
return bg_ok; /* Just allow the IO */
/* If the process group of the process is orphaned, return EIO */
else if (tc ()->is_orphaned_process_group (myself->pgid))
{
termios_printf ("process group is orphaned");
set_errno (EIO); /* This is an IO error */
return bg_error;
}
/* Otherwise, if signalling is desired, the signal is sent to all processes in
the process group */
else if (!dontsignal)
{
/* Don't raise a SIGTT* signal if we have already been
interrupted by another signal. */
if (cygwait ((DWORD) 0) != WAIT_SIGNALED)
{
siginfo_t si = {0};
si.si_signo = sig;
si.si_code = SI_KERNEL;
kill_pgrp (myself->pgid, si);
}
return bg_signalled;
}
return bg_ok;
}
#define set_input_done(x) input_done = input_done || (x)
int
fhandler_termios::eat_readahead (int n)
{
int oralen = ralen ();
if (n < 0)
n = ralen () - raixget ();
if (n > 0 && ralen () > raixget ())
{
if ((int) (ralen () -= n) < (int) raixget ())
ralen () = raixget ();
/* If IUTF8 is set, the terminal is in UTF-8 mode. If so, we erase
a complete UTF-8 multibyte sequence on VERASE/VWERASE. Otherwise,
if we only erase a single byte, invalid unicode chars are left in
the input. */
if (tc ()->ti.c_iflag & IUTF8)
while (ralen () > raixget () &&
((unsigned char) rabuf ()[ralen ()] & 0xc0) == 0x80)
--ralen ();
}
oralen = oralen - ralen ();
if (raixget () >= ralen ())
raixget () = raixput () = ralen () = 0;
else if (raixput () > ralen ())
raixput () = ralen ();
return oralen;
}
inline void
fhandler_termios::echo_erase (int force)
{
if (force || tc ()->ti.c_lflag & ECHO)
doecho ("\b \b", 3);
}
line_edit_status
fhandler_termios::line_edit (const char *rptr, size_t nread, termios& ti,
ssize_t *bytes_read)
{
line_edit_status ret = line_edit_ok;
char c;
int input_done = 0;
bool sawsig = false;
int iscanon = ti.c_lflag & ICANON;
if (bytes_read)
*bytes_read = nread;
while (nread-- > 0)
{
c = *rptr++;
paranoid_printf ("char %0o", c);
if (ti.c_iflag & ISTRIP)
c &= 0x7f;
if (ti.c_lflag & ISIG)
{
int sig;
if (CCEQ (ti.c_cc[VINTR], c))
sig = SIGINT;
else if (CCEQ (ti.c_cc[VQUIT], c))
sig = SIGQUIT;
else if (CCEQ (ti.c_cc[VSUSP], c))
sig = SIGTSTP;
else
goto not_a_sig;
termios_printf ("got interrupt %d, sending signal %d", c, sig);
eat_readahead (-1);
release_input_mutex_if_necessary ();
tc ()->kill_pgrp (sig);
acquire_input_mutex_if_necessary (INFINITE);
ti.c_lflag &= ~FLUSHO;
sawsig = true;
goto restart_output;
}
not_a_sig:
if (ti.c_iflag & IXON)
{
if (CCEQ (ti.c_cc[VSTOP], c))
{
if (!tc ()->output_stopped)
tc ()->output_stopped = true;
continue;
}
else if (CCEQ (ti.c_cc[VSTART], c))
{
restart_output:
tc ()->output_stopped = false;
continue;
}
else if ((ti.c_iflag & IXANY) && tc ()->output_stopped)
goto restart_output;
}
/* Check for special chars */
if (c == '\r')
{
if (ti.c_iflag & IGNCR)
continue;
if (ti.c_iflag & ICRNL)
{
c = '\n';
set_input_done (iscanon);
}
}
else if (c == '\n')
{
if (ti.c_iflag & INLCR)
c = '\r';
else
set_input_done (iscanon);
}
if (iscanon && ti.c_lflag & IEXTEN && CCEQ (ti.c_cc[VDISCARD], c))
{
ti.c_lflag ^= FLUSHO;
continue;
}
if (!iscanon)
/* nothing */;
else if (CCEQ (ti.c_cc[VERASE], c))
{
if (eat_readahead (1))
echo_erase ();
continue;
}
else if (CCEQ (ti.c_cc[VWERASE], c))
{
int ch;
do
if (!eat_readahead (1))
break;
else
echo_erase ();
while ((ch = peek_readahead (1)) >= 0 && !isspace (ch));
continue;
}
else if (CCEQ (ti.c_cc[VKILL], c))
{
int nchars = eat_readahead (-1);
if (ti.c_lflag & ECHO)
while (nchars--)
echo_erase (1);
continue;
}
else if (CCEQ (ti.c_cc[VREPRINT], c))
{
if (ti.c_lflag & ECHO)
{
doecho ("\n\r", 2);
doecho (rabuf (), ralen ());
}
continue;
}
else if (CCEQ (ti.c_cc[VEOF], c))
{
termios_printf ("EOF");
accept_input ();
ret = line_edit_input_done;
continue;
}
else if (CCEQ (ti.c_cc[VEOL], c) ||
CCEQ (ti.c_cc[VEOL2], c) ||
c == '\n')
{
set_input_done (1);
termios_printf ("EOL");
}
if (ti.c_iflag & IUCLC && isupper (c))
c = cyg_tolower (c);
put_readahead (c);
if (ti.c_lflag & ECHO)
doecho (&c, 1);
/* Write in chunks of 32 bytes to reduce the number of WriteFile calls
in non-canonical mode. */
if ((!iscanon && ralen () >= 32) || input_done)
{
int status = accept_input ();
if (status != 1)
{
ret = status ? line_edit_error : line_edit_pipe_full;
nread += ralen ();
break;
}
ret = line_edit_input_done;
input_done = 0;
}
}
/* If we didn't write all bytes in non-canonical mode, write them now. */
if (!iscanon && ralen () > 0
&& (ret == line_edit_ok || ret == line_edit_input_done))
{
int status = accept_input ();
if (status != 1)
{
ret = status ? line_edit_error : line_edit_pipe_full;
nread += ralen ();
}
else
ret = line_edit_input_done;
}
/* Adding one compensates for the postdecrement in the above loop. */
if (bytes_read)
*bytes_read -= (nread + 1);
if (sawsig)
ret = line_edit_signalled;
return ret;
}
off_t
fhandler_termios::lseek (off_t, int)
{
set_errno (ESPIPE);
return -1;
}
void
fhandler_termios::sigflush ()
{
/* FIXME: Checking get_ttyp() for NULL is not right since it should not
be NULL while this is alive. However, we can conceivably close a
ctty while exiting and that will zero this. */
if ((!have_execed || have_execed_cygwin) && tc ()
&& (tc ()->getpgid () == myself->pgid)
&& !(tc ()->ti.c_lflag & NOFLSH))
tcflush (TCIFLUSH);
}
pid_t
fhandler_termios::tcgetsid ()
{
if (myself->ctty > 0 && myself->ctty == tc ()->ntty)
return tc ()->getsid ();
set_errno (ENOTTY);
return -1;
}
int
fhandler_termios::ioctl (int cmd, void *varg)
{
if (cmd != TIOCSCTTY)
return 1; /* Not handled by this function */
int arg = (int) (intptr_t) varg;
if (arg != 0 && arg != 1)
{
set_errno (EINVAL);
return -1;
}
termios_printf ("myself->ctty %d, myself->sid %d, myself->pid %d, arg %d, tc()->getsid () %d\n",
myself->ctty, myself->sid, myself->pid, arg, tc ()->getsid ());
if (myself->ctty > 0 || myself->sid != myself->pid || (!arg && tc ()->getsid () > 0))
{
set_errno (EPERM);
return -1;
}
myself->ctty = -1;
myself->set_ctty (this, 0);
return 0;
}