arch/um/os-Linux/tty.c

   1 /*
   2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdlib.h>
   7 #include <unistd.h>
   8 #include <errno.h>
   9 #include <fcntl.h>
  10 #include "kern_constants.h"
  11 #include "kern_util.h"
  12 #include "os.h"
  13 #include "user.h"
  14
  15 struct grantpt_info {
  16         int fd;
  17         int res;
  18         int err;
  19 };
  20
  21 static void grantpt_cb(void *arg)
  22 {
  23         struct grantpt_info *info = arg;
  24
  25         info->res = grantpt(info->fd);
  26         info->err = errno;
  27 }
  28
  29 int get_pty(void)
  30 {
  31         struct grantpt_info info;
  32         int fd, err;
  33
  34         fd = open("/dev/ptmx", O_RDWR);
  35         if (fd < 0) {
  36                 err = -errno;
  37                 printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
  38                        "err = %d\n", errno);
  39                 return err;
  40         }
  41
  42         info.fd = fd;
  43         initial_thread_cb(grantpt_cb, &info);
  44
  45         if (info.res < 0) {
  46                 err = -info.err;
  47                 printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
  48                        "errno = %d\n", -info.err);
  49                 goto out;
  50         }
  51
  52         if (unlockpt(fd) < 0) {
  53                 err = -errno;
  54                 printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
  55                        "errno = %d\n", errno);
  56                 goto out;
  57         }
  58         return fd;
  59 out:
  60         close(fd);
  61         return err;
  62 }