forkpty-aix.c

   1 /*
   2  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
   3  * Copyright (c) 2012 Ross Palmer Mohn <rpmohn@waxandwane.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  14  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  15  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #include <sys/types.h>
  19 #include <sys/ioctl.h>
  20
  21 #include <fcntl.h>
  22 #include <stdlib.h>
  23 #include <stropts.h>
  24 #include <unistd.h>
  25 #include <paths.h>
  26
  27 /* Fatal errors. */
  28 #ifdef NDEBUG
  29  #define debug(format, args...)
  30 #else
  31  #define debug eprint
  32 #endif
  33 #define fatal(msg) debug("%s: %s", __func__, msg);
  34
  35 pid_t
  36 forkpty(int *master, char *name, struct termios *tio, struct winsize *ws)
  37 {
  38         int     slave, fd;
  39         char   *path;
  40         pid_t   pid;
  41         struct termios tio2;
  42
  43         if ((*master = open("/dev/ptc", O_RDWR|O_NOCTTY)) == -1)
  44                 return (-1);
  45
  46         if ((path = ttyname(*master)) == NULL)
  47                 goto out;
  48         if ((slave = open(path, O_RDWR|O_NOCTTY)) == -1)
  49                 goto out;
  50
  51         switch (pid = fork()) {
  52         case -1:
  53                 goto out;
  54         case 0:
  55                 close(*master);
  56
  57                 fd = open(_PATH_TTY, O_RDWR|O_NOCTTY);
  58                 if (fd >= 0) {
  59                         ioctl(fd, TIOCNOTTY, NULL);
  60                         close(fd);
  61                 }
  62
  63                 if (setsid() < 0)
  64                         fatal("setsid");
  65
  66                 fd = open(_PATH_TTY, O_RDWR|O_NOCTTY);
  67                 if (fd >= 0)
  68                         fatal("open succeeded (failed to disconnect)");
  69
  70                 fd = open(path, O_RDWR);
  71                 if (fd < 0)
  72                         fatal("open failed");
  73                 close(fd);
  74
  75                 fd = open("/dev/tty", O_WRONLY);
  76                 if (fd < 0)
  77                         fatal("open failed");
  78                 close(fd);
  79
  80                 if (tcgetattr(slave, &tio2) != 0)
  81                         fatal("tcgetattr failed");
  82                 if (tio != NULL)
  83                         memcpy(tio2.c_cc, tio->c_cc, sizeof tio2.c_cc);
  84                 tio2.c_cc[VERASE] = '\177';
  85                 if (tcsetattr(slave, TCSAFLUSH, &tio2) == -1)
  86                         fatal("tcsetattr failed");
  87                 if (ioctl(slave, TIOCSWINSZ, ws) == -1)
  88                         fatal("ioctl failed");
  89
  90                 dup2(slave, 0);
  91                 dup2(slave, 1);
  92                 dup2(slave, 2);
  93                 if (slave > 2)
  94                         close(slave);
  95                 return (0);
  96         }
  97
  98         close(slave);
  99         return (pid);
 100
 101 out:
 102         if (*master != -1)
 103                 close(*master);
 104         if (slave != -1)
 105                 close(slave);
 106         return (-1);
 107 }