lib/libutil/pty.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   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 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)pty.c       8.3 (Berkeley) 5/16/94";
  36 #endif
  37 #endif /* LIBC_SCCS and not lint */
  38
  39 #include <sys/types.h>
  40 #include <sys/ioctl.h>
  41 #include <sys/stat.h>
  42
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <grp.h>
  46 #include <libutil.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <termios.h>
  50 #include <unistd.h>
  51
  52 int
  53 openpty(int *amaster, int *aslave, char *name, struct termios *termp,
  54     struct winsize *winp)
  55 {
  56         const char *slavename;
  57         int master, slave;
  58
  59         master = posix_openpt(O_RDWR);
  60         if (master == -1)
  61                 return (-1);
  62
  63         if (grantpt(master) == -1) {
  64                 close(master);
  65                 return (-1);
  66         }
  67
  68         slavename = ptsname(master);
  69         if (slavename == NULL) {
  70                 close(master);
  71                 return (-1);
  72         }
  73
  74         if (revoke(slavename) == -1) {
  75                 close(master);
  76                 return (-1);
  77         }
  78
  79         slave = open(slavename, O_RDWR);
  80         if (slave == -1) {
  81                 close(master);
  82                 return (-1);
  83         }
  84
  85         if (unlockpt(master) == -1) {
  86                 close(master);
  87                 close(slave);
  88                 return (-1);
  89         }
  90
  91         *amaster = master;
  92         *aslave = slave;
  93
  94         if (name)
  95                 strcpy(name, slavename);
  96         if (termp)
  97                 tcsetattr(slave, TCSAFLUSH, termp);
  98         if (winp)
  99                 ioctl(slave, TIOCSWINSZ, (char *)winp);
 100
 101         return (0);
 102 }
 103
 104 int
 105 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp)
 106 {
 107         int master, slave, pid;
 108
 109         if (openpty(&master, &slave, name, termp, winp) == -1)
 110                 return (-1);
 111         switch (pid = fork()) {
 112         case -1:
 113                 return (-1);
 114         case 0:
 115                 /*
 116                  * child
 117                  */
 118                 (void) close(master);
 119                 login_tty(slave);
 120                 return (0);
 121         }
 122         /*
 123          * parent
 124          */
 125         *amaster = master;
 126         (void) close(slave);
 127         return (pid);
 128 }