libutil/login_tty.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /* Make FD be the controlling terminal, stdin, stdout, and stderr;
  31    then close FD.  Returns 0 on success, nonzero on error.  */
  32
  33 #include <sys/param.h>
  34 #include <sys/ioctl.h>
  35 #include <unistd.h>
  36 #include <fcntl.h>
  37 #include <utmp.h>
  38
  39 int login_tty(int fd)
  40 {
  41         (void) setsid();
  42 #ifdef TIOCSCTTY
  43         if (ioctl(fd, TIOCSCTTY, (char *)NULL) == -1)
  44                 return (-1);
  45 #else
  46         {
  47           /* This might work.  */
  48           char *fdname = ttyname (fd);
  49           int newfd;
  50           if (fdname)
  51             {
  52               if (fd != 0)
  53                 (void) close (0);
  54               if (fd != 1)
  55                 (void) close (1);
  56               if (fd != 2)
  57                 (void) close (2);
  58               newfd = open (fdname, O_RDWR);
  59               (void) close (newfd);
  60             }
  61         }
  62 #endif
  63         (void) dup2(fd, 0);
  64         (void) dup2(fd, 1);
  65         (void) dup2(fd, 2);
  66         if (fd > 2)
  67                 (void) close(fd);
  68         return (0);
  69 }
  70 libutil_hidden_def(login_tty)