2002-02-10 Marcus Brinkmann <marcus@gnu.org>

	* term.h: Include `hurd/hurd_types.h'.
	(struct bottomhalf): Change the return types of the following
	members from void to error_t: abandon_physical_output,
	suspend_physical_output, notice_input_flushed, desert_dtr,
	set_break, clear_break, start_output, set_bits (which now takes an
	struct termios * as argument), mdmctl and mdmstate (which now
	takes an int * as argument).  Add new members init and type.
	(bottom): Define as const.
	(devio_bottom, ptyio_bottom): Declare as const.
	(drop_output): Change return type from void to error_t.
	(ptyio_init): Remove prototype.
	* devio.c (devio_abandon_physical_output): Change return value to
	error_t, and return 0.
	(devio_suspend_physical_output): Likewise.
	(devio_notice_input_flushed): Likewise.
	(devio_desert_dtr): Likewise.
	(devio_set_break): Likewise.
	(devio_clear_break): Likewise.
	(devio_start_output): Likewise.
	(devio_set_bits): Likewise.
	(devio_mdmctl): Likewise.
	(devio_mdmstate): Likewise.
        (init_devio): Rename to ...
	(devio_init): ... this.  Do not give constructor attribute.
	Change return type to error_t, and return an error value, rather
	than bailing out.  Declare as static.
	(devio_bottom): Add type TERM_ON_MACHDEV and init function
	devio_init.
	(devio_set_bits): Accept new argument STATE and use that to work
	out the terminal state, rather than changing the global termstate.
	(devio_mdmstate): Accept new argument STATE and use that to return
	the bits.
	* ptyio.c: Do not include `hurd/hurd_types.h'.
	(ptyio_suspend_physical_output): Change return value to error_t,
	and return 0.  Likewise.
	(ptyio_notice_input_flushed): Likewise.
	(ptyio_desert_dtr): Likewise.
	(ptyio_set_bits): Likewise.
	(ptyio_set_break): Likewise.
	(ptyio_clear_break): Likewise.
	(ptyio_mdmctl): Likewise.
	(ptyio_start_output): Likewise.
	(ptyio_abandon_physical_output): Likewise.
	(ptyio_mdmstate): Likewise, and accept new argument STATE.
	(ptyio_init): Declare as static and change return type to error_t.
	(ptyio_bottom): Add type TERM_ON_MASTERPTY and init function
	ptyio_init.
	(ptyio_set_bits): Accept new argument STATE and use that to work
	out the terminal state, rather than changing the global termstate.
	(ptyio_mdmstate): Accept new argument STATE and use that to return
	the bits.
	* munge.c (drop_output): Change return value to error_t.  Only
	clear queue if there was no error.
	* users.c (S_term_get_bottom_type): Just return bottom->type.
	(set_state): Rework logic to take possible errors into account,
	and to delay changing the termstate until we know that we won't
	fail.
	(S_tioctl_tiocflush): Return errors properly, and clear queue only
	if notice_input_flushed succeeded.
	(open_hook): Save error value of set_bits.  Save old termflags and
	restore them if if set_bits failed.  Call set_bits with correct
	arguments.
	(S_tioctl_tiocmods): Set err to result of mdmctl.
	(S_tioctl_tiocmset): Likewise.
	(S_tioctl_tiocmbic): Likewise.
	(S_tioctl_tiocmbis): Likewise.
	(S_tioctl_tioccdtr): Likewise.
	(S_tioctl_tiocsdtr): Likewise.
	(S_tioctl_tioccbrk): Likewise for clear_break.
	(S_tioctl_tiocsbrk): Likewise for set_break.
	(S_tioctl_tiocstart): Likewise for start_output.  Save old
	termflags and restore them if if start_output failed.
	(S_tioctl_tiocstop): Likewise for stop_output.
	(S_trivfs_io_write): Abort the operation if start_output fails.
	Do not call start_output if it just failed, or if there was no
	data to be written.
	* main.c (main): Initialize bottom handler (rather than special
	casing this for ptyio).

	* users.c (open_hook): Use memcpy instead bcopy and memset instead
	bzero.
	(S_tioctl_tiocgeta): Likewise.
	(set_state): Likewise.
	(open_hook): Likewise.
	* munge.c (rescan_inputq): Likewise.

7 files changed, 282 insertions, 164 deletions

diff --git a/term/ChangeLog b/term/ChangeLog
index ecbd117b..c9bfff50 100644
--- a/term/ChangeLog
+++ b/term/ChangeLog
@@ -1,3 +1,91 @@
+2002-02-10  Marcus Brinkmann  <marcus@gnu.org>
+
+	* term.h: Include `hurd/hurd_types.h'.
+	(struct bottomhalf): Change the return types of the following
+	members from void to error_t: abandon_physical_output,
+	suspend_physical_output, notice_input_flushed, desert_dtr,
+	set_break, clear_break, start_output, set_bits (which now takes an
+	struct termios * as argument), mdmctl and mdmstate (which now
+	takes an int * as argument).  Add new members init and type.
+	(bottom): Define as const.
+	(devio_bottom, ptyio_bottom): Declare as const.
+	(drop_output): Change return type from void to error_t.
+	(ptyio_init): Remove prototype.
+	* devio.c (devio_abandon_physical_output): Change return value to
+	error_t, and return 0.
+	(devio_suspend_physical_output): Likewise.
+	(devio_notice_input_flushed): Likewise.
+	(devio_desert_dtr): Likewise.
+	(devio_set_break): Likewise.
+	(devio_clear_break): Likewise.
+	(devio_start_output): Likewise.
+	(devio_set_bits): Likewise.
+	(devio_mdmctl): Likewise.
+	(devio_mdmstate): Likewise.
+        (init_devio): Rename to ...
+	(devio_init): ... this.  Do not give constructor attribute.
+	Change return type to error_t, and return an error value, rather
+	than bailing out.  Declare as static.
+	(devio_bottom): Add type TERM_ON_MACHDEV and init function
+	devio_init.
+	(devio_set_bits): Accept new argument STATE and use that to work
+	out the terminal state, rather than changing the global termstate.
+	(devio_mdmstate): Accept new argument STATE and use that to return
+	the bits.
+	* ptyio.c: Do not include `hurd/hurd_types.h'.
+	(ptyio_suspend_physical_output): Change return value to error_t,
+	and return 0.  Likewise.
+	(ptyio_notice_input_flushed): Likewise.
+	(ptyio_desert_dtr): Likewise.
+	(ptyio_set_bits): Likewise.
+	(ptyio_set_break): Likewise.
+	(ptyio_clear_break): Likewise.
+	(ptyio_mdmctl): Likewise.
+	(ptyio_start_output): Likewise.
+	(ptyio_abandon_physical_output): Likewise.
+	(ptyio_mdmstate): Likewise, and accept new argument STATE.
+	(ptyio_init): Declare as static and change return type to error_t.
+	(ptyio_bottom): Add type TERM_ON_MASTERPTY and init function
+	ptyio_init.
+	(ptyio_set_bits): Accept new argument STATE and use that to work
+	out the terminal state, rather than changing the global termstate.
+	(ptyio_mdmstate): Accept new argument STATE and use that to return
+	the bits.
+	* munge.c (drop_output): Change return value to error_t.  Only
+	clear queue if there was no error.
+	* users.c (S_term_get_bottom_type): Just return bottom->type.
+	(set_state): Rework logic to take possible errors into account,
+	and to delay changing the termstate until we know that we won't
+	fail.
+	(S_tioctl_tiocflush): Return errors properly, and clear queue only
+	if notice_input_flushed succeeded.
+	(open_hook): Save error value of set_bits.  Save old termflags and
+	restore them if if set_bits failed.  Call set_bits with correct
+	arguments.
+	(S_tioctl_tiocmods): Set err to result of mdmctl.
+	(S_tioctl_tiocmset): Likewise.
+	(S_tioctl_tiocmbic): Likewise.
+	(S_tioctl_tiocmbis): Likewise.
+	(S_tioctl_tioccdtr): Likewise.
+	(S_tioctl_tiocsdtr): Likewise.
+	(S_tioctl_tioccbrk): Likewise for clear_break.
+	(S_tioctl_tiocsbrk): Likewise for set_break.
+	(S_tioctl_tiocstart): Likewise for start_output.  Save old
+	termflags and restore them if if start_output failed.
+	(S_tioctl_tiocstop): Likewise for stop_output.
+	(S_trivfs_io_write): Abort the operation if start_output fails.
+	Do not call start_output if it just failed, or if there was no
+	data to be written.
+	* main.c (main): Initialize bottom handler (rather than special
+	casing this for ptyio).
+
+	* users.c (open_hook): Use memcpy instead bcopy and memset instead
+	bzero.
+	(S_tioctl_tiocgeta): Likewise.
+	(set_state): Likewise.
+	(open_hook): Likewise.
+	* munge.c (rescan_inputq): Likewise.
+	
 2002-01-30  Marcus Brinkmann  <marcus@gnu.org>
 
 	* users.c (trivfs_S_io_select): Remove IDTAG argument.
diff --git a/term/devio.c b/term/devio.c
index f1bdab2d..55b26336 100644
--- a/term/devio.c
+++ b/term/devio.c
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1995,96,98,99,2000,01 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,98,99,2000,01,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -98,20 +98,20 @@ static int output_stopped;
 static int char_size_mask_xxx = 0xff;
 
 /* Forward */
-static void devio_desert_dtr ();
+static error_t devio_desert_dtr ();
 
-static void init_devio (void) __attribute__ ((constructor));
-static void
-init_devio ()
+static error_t
+devio_init (void)
 {
   mach_port_t host_priv;
   error_t err;
 
   err = get_privileged_ports (&host_priv, &device_master);
   if (err)
-    error (1, err, "Getting priviliged ports");
+    return err;
   mach_port_deallocate (mach_task_self (), host_priv);
   phys_reply_class = ports_create_class (0, 0);
+  return 0;
 }
 
 /* XXX Convert a real speed to a bogus Mach speed.  Return
@@ -237,7 +237,7 @@ bogus_speed_to_real_speed (int bspeed)
 
 /* If there are characters on the output queue and no
    pending output requests, then send them. */
-static void
+static error_t
 devio_start_output ()
 {
   char *cp;
@@ -247,7 +247,7 @@ devio_start_output ()
   size = qsize (outputq);
 
   if (!size || output_pending || (termflags & USER_OUTPUT_SUSP))
-    return;
+    return 0;
 
   if (output_stopped)
     {
@@ -278,6 +278,7 @@ devio_start_output ()
     devio_desert_dtr ();
   else if (!err)
     output_pending = 1;
+  return 0;
 }
 
 error_t
@@ -368,19 +369,21 @@ device_read_reply_inband (mach_port_t replypt,
   return 0;
 }
 
-static void
+static error_t
 devio_set_break ()
 {
   device_set_status (phys_device, TTY_SET_BREAK, 0, 0);
+  return 0;
 }
 
-static void
+static error_t
 devio_clear_break ()
 {
   device_set_status (phys_device, TTY_CLEAR_BREAK, 0, 0);
+  return 0;
 }
 
-static void
+static error_t
 devio_abandon_physical_output ()
 {
   int val = D_WRITE;
@@ -388,7 +391,7 @@ devio_abandon_physical_output ()
   /* If this variable is clear, then carrier is gone, so we
      have nothing to do. */
   if (!phys_reply_writes_pi)
-    return;
+    return 0;
 
   mach_port_deallocate (mach_task_self (), phys_reply_writes);
   ports_reallocate_port (phys_reply_writes_pi);
@@ -397,9 +400,10 @@ devio_abandon_physical_output ()
   device_set_status (phys_device, TTY_FLUSH, &val, TTY_FLUSH_COUNT);
   npending_output = 0;
   output_pending = 0;
+  return 0;
 }
 
-static void
+static error_t
 devio_suspend_physical_output ()
 {
   if (!output_stopped)
@@ -407,11 +411,13 @@ devio_suspend_physical_output ()
       device_set_status (phys_device, TTY_STOP, 0, 0);
       output_stopped = 1;
     }
+  return 0;
 }
 
-static void
+static error_t
 devio_notice_input_flushed ()
 {
+  return 0;
 }
 
 static int
@@ -460,7 +466,7 @@ initial_open ()
   return err;
 }
 
-static void
+static error_t
 devio_desert_dtr ()
 {
   int bits;
@@ -471,6 +477,7 @@ devio_desert_dtr ()
 		     (dev_status_t) &bits, TTY_MODEM_COUNT);
 
   report_carrier_off ();
+  return 0;
 }
 
 static error_t
@@ -580,20 +587,20 @@ device_open_reply (mach_port_t replyport,
 /* Adjust physical state on the basis of the terminal state.
    Where it isn't possible, mutate terminal state to match
    reality. */
-static void
-devio_set_bits ()
+static error_t
+devio_set_bits (struct termios *state)
 {
-  if (!(termstate.c_cflag & CIGNORE) && phys_device != MACH_PORT_NULL)
+  if (!(state->c_cflag & CIGNORE) && phys_device != MACH_PORT_NULL)
     {
       struct tty_status ttystat;
       int cnt = TTY_STATUS_COUNT;
 
       /* Find the current state. */
       device_get_status (phys_device, TTY_STATUS, (dev_status_t) &ttystat, &cnt);
-      if (termstate.__ispeed)
-	real_speed_to_bogus_speed (termstate.__ispeed, &ttystat.tt_ispeed);
-      if (termstate.__ospeed)
-	real_speed_to_bogus_speed (termstate.__ospeed, &ttystat.tt_ospeed);
+      if (state->__ispeed)
+	real_speed_to_bogus_speed (state->__ispeed, &ttystat.tt_ispeed);
+      if (state->__ospeed)
+	real_speed_to_bogus_speed (state->__ospeed, &ttystat.tt_ospeed);
 
       /* Try and set it. */
       device_set_status (phys_device, TTY_STATUS,
@@ -602,19 +609,19 @@ devio_set_bits ()
       /* And now make termstate match reality. */
       cnt = TTY_STATUS_COUNT;
       device_get_status (phys_device, TTY_STATUS, (dev_status_t) &ttystat, &cnt);
-      termstate.__ispeed = bogus_speed_to_real_speed (ttystat.tt_ispeed);
-      termstate.__ospeed = bogus_speed_to_real_speed (ttystat.tt_ospeed);
+      state->__ispeed = bogus_speed_to_real_speed (ttystat.tt_ispeed);
+      state->__ospeed = bogus_speed_to_real_speed (ttystat.tt_ospeed);
 
       /* Mach forces us to use the normal stop bit convention:
 	 two bits at 110 bps; 1 bit otherwise. */
-      if (termstate.__ispeed == 110)
-	termstate.c_cflag |= CSTOPB;
+      if (state->__ispeed == 110)
+	state->c_cflag |= CSTOPB;
       else
-	termstate.c_cflag &= ~CSTOPB;
+	state->c_cflag &= ~CSTOPB;
 
       /* Figure out how to munge input, since we are unable to actually
 	 affect what the hardware does. */
-      switch (termstate.c_cflag & CSIZE)
+      switch (state->c_cflag & CSIZE)
 	{
 	case CS5:
 	  char_size_mask_xxx = 0x1f;
@@ -633,12 +640,13 @@ devio_set_bits ()
 	  char_size_mask_xxx = 0xff;
 	  break;
 	}
-      if (termstate.c_cflag & PARENB)
+      if (state->c_cflag & PARENB)
 	char_size_mask_xxx |= 0x80;
     }
+  return 0;
 }
 
-static void
+static error_t
 devio_mdmctl (int how, int bits)
 {
   int oldbits, newbits;
@@ -661,21 +669,25 @@ devio_mdmctl (int how, int bits)
 
   device_set_status (phys_device, TTY_MODEM,
 		     (dev_status_t) &newbits, TTY_MODEM_COUNT);
+
+  return 0;
 }
 
-static int
-devio_mdmstate ()
+static error_t
+devio_mdmstate (int *state)
 {
   int bits, cnt;
 
   cnt = TTY_MODEM_COUNT;
   device_get_status (phys_device, TTY_MODEM, (dev_status_t) &bits, &cnt);
-  if (cnt != TTY_MODEM_COUNT)
-    return 0;
+  if (cnt == TTY_MODEM_COUNT)
+    *state = bits;
   else
-    return bits;
+    *state = 0;
+  return 0;
 }
 
+
 /* Unused stubs */
 kern_return_t
 device_read_reply (mach_port_t port,
@@ -747,8 +759,10 @@ ports_do_mach_notify_send_once (mach_port_t notify)
 }
 
 
-struct bottomhalf devio_bottom =
+const struct bottomhalf devio_bottom =
 {
+  TERM_ON_MACHDEV,
+  devio_init,
   devio_start_output,
   devio_set_break,
   devio_clear_break,
diff --git a/term/main.c b/term/main.c
index 8d35a679..c49168c7 100644
--- a/term/main.c
+++ b/term/main.c
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1997, 2000, 2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -194,8 +194,12 @@ main (int argc, char **argv)
   
   outputq = create_queue (256, QUEUE_LOWAT, QUEUE_HIWAT);
   
-  if (bottom == &ptyio_bottom)
-    ptyio_init ();
+  errno = (*bottom->init) ();
+  if (errno)
+    {
+      perror ("Initializing bottom handler");
+      exit (1);
+    }
 
   condition_init (&carrier_alert);
   condition_init (&select_alert);
diff --git a/term/munge.c b/term/munge.c
index 34d2210a..32d87c98 100644
--- a/term/munge.c
+++ b/term/munge.c
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1995, 1996, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1999, 2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -681,20 +681,24 @@ rescan_inputq ()
 
   n = qsize (inputq);
   buf = alloca (n * sizeof (quoted_char));
-  bcopy (inputq->cs, buf, n * sizeof (quoted_char));
+  memcpy (buf, inputq->cs, n * sizeof (quoted_char));
   clear_queue (inputq);
 
   for (i = 0; i < n; i++)
     input_character (unquote_char (buf[i]));
 }
 
-void
+
+error_t
 drop_output ()
 {
-  clear_queue (outputq);
-  (*bottom->abandon_physical_output) ();
+  error_t err = (*bottom->abandon_physical_output) ();
+  if (!err)
+    clear_queue (outputq);
+  return err;
 }
 
+
 error_t
 drain_output ()
 {
diff --git a/term/ptyio.c b/term/ptyio.c
index 9ea632a7..f2ff96e6 100644
--- a/term/ptyio.c
+++ b/term/ptyio.c
@@ -1,5 +1,5 @@
 /* 
-   Copyright (C) 1995, 1996, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1995, 1996, 1999, 2002 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -19,7 +19,6 @@
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
 
 #include <sys/ioctl.h>
-#include <hurd/hurd_types.h>
 #include <string.h>
 #include <hurd/ports.h>
 #include <unistd.h>
@@ -56,11 +55,12 @@ static int ptyopen = 0;
 static int nptyperopens = 0;
 
 
-void
-ptyio_init ()
+static error_t
+ptyio_init (void)
 {
   condition_implies (inputq->wait, &pty_select_wakeup);
   condition_implies (&pty_read_wakeup, &pty_select_wakeup);
+  return 0;
 }
     
 error_t
@@ -138,7 +138,7 @@ wake_reader ()
 
 /* Lower half for tty node */
 
-static void 
+static error_t
 ptyio_start_output ()
 {
   if (packet_mode && output_stopped && (!(termflags & USER_OUTPUT_SUSP)))
@@ -148,9 +148,10 @@ ptyio_start_output ()
       output_stopped = 0;
     }
   wake_reader ();
+  return 0;
 }
 
-static void
+static error_t
 ptyio_abandon_physical_output ()
 {
   if (packet_mode)
@@ -158,9 +159,10 @@ ptyio_abandon_physical_output ()
       control_byte |= TIOCPKT_FLUSHWRITE;
       wake_reader ();
     }
+  return 0;
 }
 
-static void
+static error_t
 ptyio_suspend_physical_output ()
 {
   if (packet_mode)
@@ -170,6 +172,7 @@ ptyio_suspend_physical_output ()
       output_stopped = 1;
       wake_reader ();
     }
+  return 0;
 }
 
 static int 
@@ -179,7 +182,7 @@ ptyio_pending_output_size ()
   return 0;
 }
 
-static void
+static error_t
 ptyio_notice_input_flushed ()
 {
   if (packet_mode)
@@ -187,6 +190,7 @@ ptyio_notice_input_flushed ()
       control_byte |= TIOCPKT_FLUSHREAD;
       wake_reader ();
     }
+  return 0;
 }
 
 static error_t 
@@ -196,22 +200,23 @@ ptyio_assert_dtr ()
   return 0;
 }
 
-static void 
+static error_t 
 ptyio_desert_dtr ()
 {
   dtr_on = 0;
   wake_reader ();
+  return 0;
 }
 
-static void 
-ptyio_set_bits ()
+static error_t 
+ptyio_set_bits (struct termios *state)
 {
   if (packet_mode)
     {
       int wakeup = 0;
-      int stop = ((termstate.c_iflag & IXON) 
-		  && CCEQ (termstate.c_cc[VSTOP], CHAR_DC3)
-		  && CCEQ (termstate.c_cc[VSTART], CHAR_DC1));
+      int stop = ((state->c_iflag & IXON) 
+		  && CCEQ (state->c_cc[VSTOP], CHAR_DC3)
+		  && CCEQ (state->c_cc[VSTART], CHAR_DC1));
   
       if (external_processing)
 	{
@@ -237,33 +242,40 @@ ptyio_set_bits ()
       if (wakeup)
 	wake_reader ();
     }
+  return 0;
 }
 
 /* These do nothing.  In BSD the associated ioctls get errors, but
    I'd rather just ignore them. */
-static void 
+static error_t 
 ptyio_set_break ()
 {
+  return 0;
 }
 
-static void 
+static error_t
 ptyio_clear_break ()
 {
+  return 0;
 }
 
-static void
+static error_t
 ptyio_mdmctl (int a, int b)
 {
+  return 0;
 }
 
-static int
-ptyio_mdmstate ()
+static error_t
+ptyio_mdmstate (int *state)
 {
+  *state = 0;
   return 0;
 }
 
-struct bottomhalf ptyio_bottom =
+const struct bottomhalf ptyio_bottom =
 {
+  TERM_ON_MASTERPTY,
+  ptyio_init,
   ptyio_start_output,
   ptyio_set_break,
   ptyio_clear_break,
diff --git a/term/term.h b/term/term.h
index 565fe2f2..aafc844a 100644
--- a/term/term.h
+++ b/term/term.h
@@ -25,6 +25,7 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <fcntl.h>
+#include <hurd/hurd_types.h>
 
 #undef MDMBUF
 #undef ECHO
@@ -140,22 +141,24 @@ mode_t term_mode;
 /* Functions a bottom half defines */
 struct bottomhalf
 {
-  void (*start_output) (void);
-  void (*set_break) (void);
-  void (*clear_break) (void);
-  void (*abandon_physical_output) (void);
-  void (*suspend_physical_output) (void);
+  enum term_bottom_type type;
+  error_t (*init) (void);
+  error_t (*start_output) (void);
+  error_t (*set_break) (void);
+  error_t (*clear_break) (void);
+  error_t (*abandon_physical_output) (void);
+  error_t (*suspend_physical_output) (void);
   int (*pending_output_size) (void);
-  void (*notice_input_flushed) (void);
+  error_t (*notice_input_flushed) (void);
   error_t (*assert_dtr) (void);
-  void (*desert_dtr) (void);
-  void (*set_bits) (void);
-  void (*mdmctl) (int, int);
-  int (*mdmstate) (void);
+  error_t (*desert_dtr) (void);
+  error_t (*set_bits) (struct termios *state);
+  error_t (*mdmctl) (int how, int bits);
+  error_t (*mdmstate) (int *state);
 };
 
-struct bottomhalf *bottom;
-extern struct bottomhalf devio_bottom, ptyio_bottom;
+const struct bottomhalf *bottom;
+extern const struct bottomhalf devio_bottom, ptyio_bottom;
 
 
 /* Character queues */
@@ -313,7 +316,7 @@ void report_carrier_error (error_t);
 
 
 /* Other decls */
-void drop_output (void);
+error_t drop_output (void);
 void send_signal (int);
 error_t drain_output ();
 void output_character (int);
@@ -322,9 +325,6 @@ void rescan_inputq (void);
 void write_character (int);
 void init_users (void);
 
-/* Call this before using ptyio_bottom.  */
-void ptyio_init (void);
-
 /* kludge--these are pty versions of trivfs_S_io_* functions called by
    the real functions in users.c to do work for ptys.  */
 error_t pty_io_write (struct trivfs_protid *, char *,
diff --git a/term/users.c b/term/users.c
index 77af90d6..0d3297b2 100644
--- a/term/users.c
+++ b/term/users.c
@@ -1,5 +1,5 @@
 /*
-   Copyright (C) 1995,96,97,98,99,2000,01 Free Software Foundation, Inc.
+   Copyright (C) 1995,96,97,98,99,2000,01,02 Free Software Foundation, Inc.
    Written by Michael I. Bushnell, p/BSG.
 
    This file is part of the GNU Hurd.
@@ -152,7 +152,7 @@ open_hook (struct trivfs_control *cntl,
 
   if (!(termflags & TTY_OPEN))
     {
-      bzero (&termstate, sizeof termstate);
+      memset (&termstate, 0, sizeof termstate);
 
       /* This is different from BSD: we don't turn on ISTRIP,
 	 and we use CS8 rather than CS7|PARENB.  */
@@ -162,9 +162,9 @@ open_hook (struct trivfs_control *cntl,
 			    | ECHOE|ECHOKE|ECHOCTL);
       termstate.c_cflag |= CREAD | CS8 | HUPCL;
 
-      bcopy (ttydefchars, termstate.c_cc, NCCS);
+      memcpy (termstate.c_cc, ttydefchars, NCCS);
 
-      bzero (&window_size, sizeof window_size);
+      memset (&window_size, 0, sizeof window_size);
 
       termflags |= NO_OWNER;
     }
@@ -212,8 +212,13 @@ open_hook (struct trivfs_control *cntl,
 
   if (!err)
     {
-      termflags |= TTY_OPEN;
-      (*bottom->set_bits) ();
+      struct termios state = termstate;
+      err = (*bottom->set_bits) (&state);
+      if (!err)
+	{
+	  termstate = state;
+	  termflags |= TTY_OPEN;
+	}
     }
 
   mutex_unlock (&global_lock);
@@ -560,6 +565,7 @@ trivfs_S_io_write (struct trivfs_protid *cred,
 {
   int i;
   int cancel;
+  error_t err = 0;
 
   if (!cred)
     return EOPNOTSUPP;
@@ -595,9 +601,14 @@ trivfs_S_io_write (struct trivfs_protid *cred,
     {
       while (!qavail (outputq) && !cancel)
 	{
-	  (*bottom->start_output) ();
-	  if (!qavail (outputq))
-	    cancel = hurd_condition_wait (outputq->wait, &global_lock);
+	  err = (*bottom->start_output) ();
+	  if (err)
+	    cancel = 1;
+	  else
+	    {
+	      if (!qavail (outputq))
+		cancel = hurd_condition_wait (outputq->wait, &global_lock);
+	    }
 	}
       if (cancel)
 	break;
@@ -607,7 +618,8 @@ trivfs_S_io_write (struct trivfs_protid *cred,
 
   *amt = i;
 
-  (*bottom->start_output) ();
+  if (!err && datalen)
+    (*bottom->start_output) ();
 
   trivfs_set_mtime (termctl);
 
@@ -615,7 +627,7 @@ trivfs_S_io_write (struct trivfs_protid *cred,
 
   mutex_unlock (&global_lock);
 
-  return ((cancel && datalen && !*amt) ? EINTR : 0);
+  return ((cancel && datalen && !*amt) ? (err ?: EINTR) : 0);
 }
 
 /* Called for user reads from the terminal. */
@@ -882,6 +894,8 @@ S_tioctl_tiocmodg (io_t port,
 		   int *state)
 {
   struct trivfs_protid *cred = ports_lookup_port (term_bucket, port, 0);
+  error_t err = 0;
+
   if (!cred)
     return EOPNOTSUPP;
 
@@ -893,11 +907,11 @@ S_tioctl_tiocmodg (io_t port,
     }
 
   mutex_lock (&global_lock);
-  *state = (*bottom->mdmstate) ();
+  err = (*bottom->mdmstate) (state);
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
-  return 0;
+  return err;
 }
 
 /* TIOCMODS ioctl -- Set modem state */
@@ -922,10 +936,7 @@ S_tioctl_tiocmods (io_t port,
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->mdmctl) (MDMCTL_SET, state);
-      err = 0;
-    }
+    err = (*bottom->mdmctl) (MDMCTL_SET, state);
 
   mutex_unlock (&global_lock);
 
@@ -1001,8 +1012,8 @@ S_tioctl_tiocflush (io_t port,
 		    int flags)
 {
   struct trivfs_protid *cred = ports_lookup_port (term_bucket, port, 0);
+  error_t err = 0;
 
-  error_t err;
   if (!cred)
     return EOPNOTSUPP;
 
@@ -1024,14 +1035,13 @@ S_tioctl_tiocflush (io_t port,
 
       if (flags & O_READ)
 	{
-	  clear_queue (inputq);
-	  (*bottom->notice_input_flushed) ();
+	  err = (*bottom->notice_input_flushed) ();
+	  if (!err)
+	    clear_queue (inputq);
 	}
 
-      if (flags & O_WRITE)
-	drop_output ();
-
-      err = 0;
+      if (!err && (flags & O_WRITE))
+	err = drop_output ();
     }
 
   mutex_unlock (&global_lock);
@@ -1063,7 +1073,7 @@ S_tioctl_tiocgeta (io_t port,
   modes[1] = termstate.c_oflag;
   modes[2] = termstate.c_cflag;
   modes[3] = termstate.c_lflag;
-  bcopy (termstate.c_cc, ccs, NCCS);
+  memcpy (ccs, termstate.c_cc, NCCS);
   speeds[0] = termstate.__ispeed;
   speeds[1] = termstate.__ospeed;
   mutex_unlock (&global_lock);
@@ -1084,6 +1094,7 @@ set_state (io_t port,
   struct trivfs_protid *cred = ports_lookup_port (term_bucket, port, 0);
   error_t err;
   int oldlflag;
+  struct termios state;
 
   if (!cred)
     return EOPNOTSUPP;
@@ -1105,42 +1116,47 @@ set_state (io_t port,
     {
       if (cred->pi.class == pty_class)
 	{
+	  err = (*bottom->abandon_physical_output) ();
+	  if (err)
+	    goto leave;
 	  clear_queue (outputq);
-	  (*bottom->abandon_physical_output) ();
 	}
 
       if (draino)
 	{
 	  err = drain_output ();
 	  if (err)
-	    {
-	      mutex_unlock (&global_lock);
-	      ports_port_deref (cred);
-	      return err;
-	    }
+	    goto leave;
 	}
 
       if (flushi)
 	{
+	  err = (*bottom->notice_input_flushed) ();
+	  if (err)
+	    goto leave;
 	  clear_queue (inputq);
-	  (*bottom->notice_input_flushed) ();
 	}
 
-      oldlflag = termstate.c_lflag;
-      termstate.c_iflag = modes[0];
-      termstate.c_oflag = modes[1];
-      termstate.c_cflag = modes[2];
-      termstate.c_lflag = modes[3];
-      bcopy (ccs, termstate.c_cc, NCCS);
-      termstate.__ispeed = speeds[0];
-      termstate.__ospeed = speeds[1];
+      state = termstate;
+      state.c_iflag = modes[0];
+      state.c_oflag = modes[1];
+      state.c_cflag = modes[2];
+      state.c_lflag = modes[3];
+      memcpy (state.c_cc, ccs, NCCS);
+      state.__ispeed = speeds[0];
+      state.__ospeed = speeds[1];
 
       if (external_processing)
-	termstate.c_lflag |= EXTPROC;
+	state.c_lflag |= EXTPROC;
       else
-	termstate.c_lflag &= ~EXTPROC;
+	state.c_lflag &= ~EXTPROC;
+
+      err = (*bottom->set_bits) (&state);
+      if (err)
+	goto leave;
 
-      (*bottom->set_bits) ();
+      oldlflag = termstate.c_lflag;
+      termstate = state;
 
       if (oldlflag & ICANON)
 	{
@@ -1152,17 +1168,15 @@ set_state (io_t port,
 	  if (termstate.c_lflag & ICANON)
 	    rescan_inputq ();
 	}
-      err = 0;
     }
 
+ leave:
   mutex_unlock (&global_lock);
-
   ports_port_deref (cred);
   return err;
 }
 
 
-
 /* TIOCSETA -- Set termios state */
 kern_return_t
 S_tioctl_tiocseta (io_t port,
@@ -1354,6 +1368,7 @@ S_tioctl_tiocmget (io_t port,
 		   int *bits)
 {
   struct trivfs_protid *cred = ports_lookup_port (term_bucket, port, 0);
+  error_t err = 0;
 
   if (!cred)
     return EOPNOTSUPP;
@@ -1366,11 +1381,11 @@ S_tioctl_tiocmget (io_t port,
     }
 
   mutex_lock (&global_lock);
-  *bits = (*bottom->mdmstate) ();
+  err = (*bottom->mdmstate) (bits);
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
-  return 0;
+  return err;
 }
 
 /* TIOCMSET -- Set all modem bits */
@@ -1395,10 +1410,7 @@ S_tioctl_tiocmset (io_t port,
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->mdmctl) (MDMCTL_SET, bits);
-      err = 0;
-    }
+    err = (*bottom->mdmctl) (MDMCTL_SET, bits);
 
   mutex_unlock (&global_lock);
   ports_port_deref (cred);
@@ -1427,10 +1439,7 @@ S_tioctl_tiocmbic (io_t port,
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->mdmctl) (MDMCTL_BIC, bits);
-      err = 0;
-    }
+    err = (*bottom->mdmctl) (MDMCTL_BIC, bits);
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
@@ -1460,10 +1469,7 @@ S_tioctl_tiocmbis (io_t port,
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->mdmctl) (MDMCTL_BIS, bits);
-      err = 0;
-    }
+    err = (*bottom->mdmctl) (MDMCTL_BIS, bits);
   mutex_unlock (&global_lock);
   ports_port_deref (cred);
   return err;
@@ -1492,9 +1498,12 @@ S_tioctl_tiocstart (io_t port)
     err = EBADF;
   else
     {
+      int old_termflags = termflags;
+
       termflags &= ~USER_OUTPUT_SUSP;
-      (*bottom->start_output) ();
-      err = 0;
+      err = (*bottom->start_output) ();
+      if (err)
+	termflags = old_termflags;
     }
   mutex_unlock (&global_lock);
 
@@ -1524,9 +1533,11 @@ S_tioctl_tiocstop (io_t port)
     err = EBADF;
   else
     {
+      int old_termflags = termflags;
       termflags |= USER_OUTPUT_SUSP;
-      (*bottom->suspend_physical_output) ();
-      err = 0;
+      err = (*bottom->suspend_physical_output) ();
+      if (err)
+	termflags = old_termflags;
     }
   mutex_unlock (&global_lock);
 
@@ -1690,10 +1701,7 @@ S_tioctl_tioccdtr (io_t port)
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->mdmctl) (MDMCTL_BIC, TIOCM_DTR);
-      err = 0;
-    }
+    err = (*bottom->mdmctl) (MDMCTL_BIC, TIOCM_DTR);
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
@@ -1721,10 +1729,7 @@ S_tioctl_tiocsdtr (io_t port)
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->mdmctl) (MDMCTL_BIS, TIOCM_DTR);
-      err = 0;
-    }
+    err = (*bottom->mdmctl) (MDMCTL_BIS, TIOCM_DTR);
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
@@ -1752,10 +1757,7 @@ S_tioctl_tioccbrk (io_t port)
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->clear_break) ();
-      err = 0;
-    }
+    err = (*bottom->clear_break) ();
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
@@ -1783,10 +1785,7 @@ S_tioctl_tiocsbrk (io_t port)
   if (!(cred->po->openmodes & (O_READ|O_WRITE)))
     err = EBADF;
   else
-    {
-      (*bottom->set_break) ();
-      err = 0;
-    }
+    err = (*bottom->set_break) ();
   mutex_unlock (&global_lock);
 
   ports_port_deref (cred);
@@ -2237,10 +2236,7 @@ S_term_get_bottom_type (io_t arg,
     return EOPNOTSUPP;
 
   ports_port_deref (cred);
-  if (bottom == &devio_bottom)
-    *ttype = TERM_ON_MACHDEV;
-  else
-    *ttype = TERM_ON_MASTERPTY;
+  *ttype = bottom->type;
   return 0;
 }