1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 */ 5 6 #include <stdlib.h> 7 #include <unistd.h> 8 #include <errno.h> 9 #include <fcntl.h> 10 #include <kern_util.h> 11 #include <os.h> 12 13 struct grantpt_info { 14 int fd; 15 int res; 16 int err; 17 }; 18 19 static void grantpt_cb(void *arg) 20 { 21 struct grantpt_info *info = arg; 22 23 info->res = grantpt(info->fd); 24 info->err = errno; 25 } 26 27 int get_pty(void) 28 { 29 struct grantpt_info info; 30 int fd, err; 31 32 fd = open("/dev/ptmx", O_RDWR); 33 if (fd < 0) { 34 err = -errno; 35 printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - " 36 "err = %d\n", errno); 37 return err; 38 } 39 40 info.fd = fd; 41 initial_thread_cb(grantpt_cb, &info); 42 43 if (info.res < 0) { 44 err = -info.err; 45 printk(UM_KERN_ERR "get_pty : Couldn't grant pty - " 46 "errno = %d\n", -info.err); 47 goto out; 48 } 49 50 if (unlockpt(fd) < 0) { 51 err = -errno; 52 printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - " 53 "errno = %d\n", errno); 54 goto out; 55 } 56 return fd; 57 out: 58 close(fd); 59 return err; 60 } 61