libc/src/termios/linux/tcgetattr.cpp

   1 //===-- Linux implementation of tcgetattr ---------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/termios/tcgetattr.h"
  10 #include "kernel_termios.h"
  11
  12 #include "src/__support/OSUtil/syscall.h"
  13 #include "src/__support/common.h"
  14 #include "src/__support/macros/config.h"
  15 #include "src/errno/libc_errno.h"
  16
  17 #include <asm/ioctls.h> // Safe to include without the risk of name pollution.
  18 #include <sys/syscall.h> // For syscall numbers
  19 #include <termios.h>
  20
  21 namespace LIBC_NAMESPACE_DECL {
  22
  23 LLVM_LIBC_FUNCTION(int, tcgetattr, (int fd, struct termios *t)) {
  24   LIBC_NAMESPACE::kernel_termios kt;
  25   int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, TCGETS, &kt);
  26   if (ret < 0) {
  27     libc_errno = -ret;
  28     return -1;
  29   }
  30   t->c_iflag = kt.c_iflag;
  31   t->c_oflag = kt.c_oflag;
  32   t->c_cflag = kt.c_cflag;
  33   t->c_lflag = kt.c_lflag;
  34   t->c_ispeed = kt.c_cflag & CBAUD;
  35   t->c_ospeed = kt.c_cflag & CBAUD;
  36
  37   size_t nccs = KERNEL_NCCS <= NCCS ? KERNEL_NCCS : NCCS;
  38   for (size_t i = 0; i < nccs; ++i)
  39     t->c_cc[i] = kt.c_cc[i];
  40   if (NCCS > nccs) {
  41     for (size_t i = nccs; i < NCCS; ++i)
  42       t->c_cc[i] = 0;
  43   }
  44   return 0;
  45 }
  46
  47 } // namespace LIBC_NAMESPACE_DECL