void
signal_unblock_winch (void)
{
#if defined (SIGWINCH)
sigwinch_block_count--;
if (sigwinch_block_count == 0)
UNBLOCK_SIGNAL (SIGWINCH);
#endif
}
static int allocate_master(const char ** slave_name, const char** clone) {
int master_fd = -1;
static const char * const clones[] =
/* Different pty master clone devices */
{
"/dev/ptmx", /* Various systems */
"/dev/ptm/clone", /* HPUX */
"/dev/ptc", /* AIX */
"/dev/ptmx_bsd" /* Tru64 */
};
#ifdef HAVE_GETPT /* glibc */
master_fd = getpt ();
if (master_fd >= 0)
return master_fd;
#endif /* HAVE_GETPT */
#if defined(HAVE_OPENPTY) /* BSD, Tru64, glibc */
{
int slave_fd = -1;
int rc;
BLOCK_SIGNAL (SIGCHLD);
rc = openpty (&master_fd, &slave_fd, NULL, NULL, NULL);
UNBLOCK_SIGNAL (SIGCHLD);
if (rc == 0)
{
*slave_name = ttyname (slave_fd);
retry_close (slave_fd);
return master_fd;
}
else
{
if (master_fd >= 0)
retry_close (master_fd);
if (slave_fd >= 0)
retry_close (slave_fd);
}
}
#endif /* HAVE_OPENPTY */
#if defined(HAVE__GETPTY) && defined (O_NDELAY) /* SGI */
master_fd = -1;
BLOCK_SIGNAL (SIGCHLD);
*slave_name = _getpty (&master_fd, O_RDWR | O_NDELAY, 0600, 0);
UNBLOCK_SIGNAL (SIGCHLD);
if (master_fd >= 0 && *slave_name != NULL)
return master_fd;
#endif /* HAVE__GETPTY */
/* Master clone devices are available on most systems */
{
int i;
for (i = 0; i < countof (clones); i++)
{
*clone = clones[i];
master_fd = open ((char *) *clone, // TODO: retry open
O_RDWR | O_NONBLOCK, 0);
if (master_fd >= 0)
return master_fd;
}
*clone = NULL;
}
return -1;
}
/* Open an available pty, returning a file descriptor.
Return -1 on failure. */
s48_ref_t allocate_pty(s48_call_t call) {
/* Unix98 standardized grantpt, unlockpt, and ptsname, but not the
functions required to open a master pty in the first place :-(
Modern Unix systems all seems to have convenience methods to open
a master pty fd in one function call, but there is little
agreement on how to do it.
allocate_pty() tries all the different known easy ways of opening
a pty. In case of failure, we resort to the old BSD-style pty
grovelling code in allocate_pty_the_old_fashioned_way(). */
int master_fd = -1;
const char *slave_name = NULL;
const char* clone = NULL;
int off = 0;
s48_ref_t scm_slave_name = s48_unspecific_2(call);
master_fd = allocate_master(&slave_name, &clone);
if (master_fd == -1)
return s48_false_2(call);
if (slave_name == NULL){
slave_name = allocate_slave_name(master_fd, clone);
if (slave_name == NULL){
retry_close (master_fd);
return s48_false_2(call);
}
}
scm_slave_name = s48_enter_byte_string_2(call, (char *) slave_name);
#ifdef TIOCPKT
/* In some systems (Linux through 2.0.0, at least), packet mode doesn't
get cleared when a pty is closed, so we need to clear it here.
Linux pre2.0.13 contained an attempted fix for this (from Ted Ts'o,
[email protected]), but apparently it messed up rlogind and telnetd, so he
removed the fix in pre2.0.14. - [email protected]
*/
ioctl (master_fd, TIOCPKT, (char *)&off);
#endif /* TIOCPKT */
/* We jump through some hoops to frob the pty.
It's not obvious that checking the return code here is useful. */
/* "The grantpt() function will fail if it is unable to successfully
invoke the setuid root program. It may also fail if the
application has installed a signal handler to catch SIGCHLD
signals." */
#if defined (HAVE_GRANTPT) || defined (HAVE_UNLOCKPT)
BLOCK_SIGNAL (SIGCHLD);
#if defined (HAVE_GRANTPT)
grantpt (master_fd);
#endif /* HAVE_GRANTPT */
#if defined (HAVE_UNLOCKPT)
unlockpt (master_fd);
#endif
UNBLOCK_SIGNAL (SIGCHLD);
#endif /* HAVE_GRANTPT || HAVE_UNLOCKPT */
fcntl(master_fd, F_SETFL, O_NONBLOCK);
return s48_cons_2(call, s48_enter_long_2(call, master_fd), scm_slave_name);
}
static RETSIGTYPE
info_signal_proc (int sig)
{
signal_info *old_signal_handler = NULL;
#if !defined (HAVE_SIGACTION)
/* best effort: first increment this counter and later block signals */
if (term_conf_busy)
return;
term_conf_busy++;
#if defined (HAVE_SIGPROCMASK) || defined (HAVE_SIGSETMASK)
{
sigset_t nvar, ovar;
sigemptyset (&nvar);
mask_termsig (&nvar);
sigprocmask (SIG_BLOCK, &nvar, &ovar);
}
#endif /* HAVE_SIGPROCMASK || HAVE_SIGSETMASK */
#endif /* !HAVE_SIGACTION */
switch (sig)
{
#if defined (SIGTSTP)
case SIGTSTP:
case SIGTTOU:
case SIGTTIN:
#endif
#if defined (SIGQUIT)
case SIGQUIT:
#endif
#if defined (SIGINT)
case SIGINT:
#endif
{
#if defined (SIGTSTP)
if (sig == SIGTSTP)
old_signal_handler = &old_TSTP;
if (sig == SIGTTOU)
old_signal_handler = &old_TTOU;
if (sig == SIGTTIN)
old_signal_handler = &old_TTIN;
#endif /* SIGTSTP */
#if defined (SIGQUIT)
if (sig == SIGQUIT)
old_signal_handler = &old_QUIT;
#endif /* SIGQUIT */
#if defined (SIGINT)
if (sig == SIGINT)
old_signal_handler = &old_INT;
#endif /* SIGINT */
/* For stop signals, restore the terminal IO, leave the cursor
at the bottom of the window, and stop us. */
terminal_goto_xy (0, screenheight - 1);
terminal_clear_to_eol ();
fflush (stdout);
terminal_unprep_terminal ();
restore_termsig (sig, old_signal_handler);
UNBLOCK_SIGNAL (sig);
kill (getpid (), sig);
/* The program is returning now. Restore our signal handler,
turn on terminal handling, redraw the screen, and place the
cursor where it belongs. */
terminal_prep_terminal ();
set_termsig (sig, old_signal_handler);
/* window size might be changed while sleeping */
reset_info_window_sizes ();
}
break;
#if defined (SIGWINCH) || defined (SIGUSR1)
#ifdef SIGWINCH
case SIGWINCH:
#endif
#ifdef SIGUSR1
case SIGUSR1:
#endif
{
/* Turn off terminal IO, tell our parent that the window has changed,
then reinitialize the terminal and rebuild our windows. */
#ifdef SIGWINCH
if (sig == SIGWINCH)
old_signal_handler = &old_WINCH;
#endif
#ifdef SIGUSR1
if (sig == SIGUSR1)
old_signal_handler = &old_USR1;
#endif
terminal_goto_xy (0, 0);
fflush (stdout);
terminal_unprep_terminal (); /* needless? */
restore_termsig (sig, old_signal_handler);
UNBLOCK_SIGNAL (sig);
kill (getpid (), sig);
/* After our old signal handler returns... */
set_termsig (sig, old_signal_handler); /* needless? */
terminal_prep_terminal ();
reset_info_window_sizes ();
}
break;
#endif /* SIGWINCH || SIGUSR1 */
}
#if !defined (HAVE_SIGACTION)
/* at this time it is safer to perform unblock after decrement */
term_conf_busy--;
#if defined (HAVE_SIGPROCMASK) || defined (HAVE_SIGSETMASK)
{
sigset_t nvar, ovar;
sigemptyset (&nvar);
mask_termsig (&nvar);
sigprocmask (SIG_UNBLOCK, &nvar, &ovar);
}
#endif /* HAVE_SIGPROCMASK || HAVE_SIGSETMASK */
#endif /* !HAVE_SIGACTION */
}
