diff options
Diffstat (limited to 'libc/termios/tcsetattr.c')
| -rw-r--r-- | libc/termios/tcsetattr.c | 120 |
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; +} |