Fix termios handling. Now synced with behavior of GNU libc.

 -Erik

1 files changed, 120 insertions, 0 deletions

diff --git a/libc/termios/tcsetattr.c b/libc/termios/tcsetattr.c
new file mode 100644
index 000000000..30ea46f4c
--- /dev/null
+++ b/libc/termios/tcsetattr.c
@@ -0,0 +1,120 @@
+/* Copyright (C) 1993, 1996, 1997, 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <string.h>
+#include <termios.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+
+/* The difference here is that the termios structure used in the
+   kernel is not the same as we use in the libc.  Therefore we must
+   translate it here.  */
+#include <kernel_termios.h>
+
+
+/* This is a gross hack around a kernel bug.  If the cfsetispeed functions
+   is called with the SPEED argument set to zero this means use the same
+   speed as for output.  But we don't have independent input and output
+   speeds and therefore cannot record this.
+
+   We use an unused bit in the `c_iflag' field to keep track of this
+   use of `cfsetispeed'.  The value here must correspond to the one used
+   in `speed.c'.  */
+#if !defined _HAVE_C_ISPEED || !defined _HAVE_C_OSPEED
+# define IBAUD0	020000000000
+#else
+/* If we have separate values for input and output speed don't bother
+   with this.  Define the value as zero so the compiler sees we don't
+   have to do the AND below.  */
+# define IBAUD0	0
+#endif
+
+
+/* Set the state of FD to *TERMIOS_P.  */
+int
+tcsetattr (fd, optional_actions, termios_p)
+     int fd;
+     int optional_actions;
+     const struct termios *termios_p;
+{
+  struct __kernel_termios k_termios;
+  unsigned long int cmd;
+  int retval;
+
+  switch (optional_actions)
+    {
+    case TCSANOW:
+      cmd = TCSETS;
+      break;
+    case TCSADRAIN:
+      cmd = TCSETSW;
+      break;
+    case TCSAFLUSH:
+      cmd = TCSETSF;
+      break;
+    default:
+      errno=EINVAL;
+      return -1;
+    }
+
+  k_termios.c_iflag = termios_p->c_iflag & ~IBAUD0;
+  k_termios.c_oflag = termios_p->c_oflag;
+  k_termios.c_cflag = termios_p->c_cflag;
+  k_termios.c_lflag = termios_p->c_lflag;
+  k_termios.c_line = termios_p->c_line;
+#ifdef _HAVE_C_ISPEED
+  k_termios.c_ispeed = termios_p->c_ispeed;
+#endif
+#ifdef _HAVE_C_OSPEED
+  k_termios.c_ospeed = termios_p->c_ospeed;
+#endif
+  memcpy (&k_termios.c_cc[0], &termios_p->c_cc[0],
+	  __KERNEL_NCCS * sizeof (cc_t));
+
+  retval = ioctl (fd, cmd, &k_termios);
+
+  if (retval == 0 && cmd == TCSETS)
+    {
+      /* The Linux kernel has a bug which silently ignore the invalid
+	 c_cflag on pty. We have to check it here. */
+      int save = errno;
+      retval = ioctl (fd, TCGETS, &k_termios);
+      if (retval)
+	{
+	  /* We cannot verify if the setting is ok. We don't return
+	     an error (?). */
+	  errno=save;
+	  retval = 0;
+	}
+      else if ((termios_p->c_cflag & (PARENB | CREAD))
+	       != (k_termios.c_cflag & (PARENB | CREAD))
+	       || ((termios_p->c_cflag & CSIZE)
+		   && ((termios_p->c_cflag & CSIZE)
+		       != (k_termios.c_cflag & CSIZE))))
+	{
+	  /* It looks like the Linux kernel silently changed the
+	     PARENB/CREAD/CSIZE bits in c_cflag. Report it as an
+	     error. */
+	  errno=EINVAL;
+	  retval = -1;
+	}
+    }
+
+  return retval;
+}