Initial revision
diff --git a/pty.c b/pty.c
new file mode 100644
index 0000000..440994b
--- /dev/null
+++ b/pty.c
@@ -0,0 +1,264 @@
+/*
+
+pty.c
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+                   All rights reserved
+
+Created: Fri Mar 17 04:37:25 1995 ylo
+
+Allocating a pseudo-terminal, and making it the controlling tty.
+
+*/
+
+#include "includes.h"
+RCSID("$Id: pty.c,v 1.1 1999/10/27 03:42:44 damien Exp $");
+
+#include "pty.h"
+#include "ssh.h"
+
+/* Pty allocated with _getpty gets broken if we do I_PUSH:es to it. */
+#if defined(HAVE__GETPTY) || defined(HAVE_OPENPTY)
+#undef HAVE_DEV_PTMX
+#endif
+
+#ifndef O_NOCTTY
+#define O_NOCTTY 0
+#endif
+
+/* Allocates and opens a pty.  Returns 0 if no pty could be allocated,
+   or nonzero if a pty was successfully allocated.  On success, open file
+   descriptors for the pty and tty sides and the name of the tty side are 
+   returned (the buffer must be able to hold at least 64 characters). */
+
+int pty_allocate(int *ptyfd, int *ttyfd, char *namebuf)
+{
+#ifdef HAVE_OPENPTY
+
+  /* openpty(3) exists in OSF/1 and some other os'es */
+
+  int i;
+
+  i = openpty(ptyfd, ttyfd, namebuf, NULL, NULL);
+
+  if (i < 0) 
+    {
+      error("openpty: %.100s", strerror(errno));
+      return 0;
+    }
+  
+  return 1;
+
+#else /* HAVE_OPENPTY */
+#ifdef HAVE__GETPTY
+
+  /* _getpty(3) exists in SGI Irix 4.x, 5.x & 6.x -- it generates more
+     pty's automagically when needed */
+
+  char *slave;
+
+  slave = _getpty(ptyfd, O_RDWR, 0622, 0);
+  if (slave == NULL)
+    {
+      error("_getpty: %.100s", strerror(errno));
+      return 0;
+    }
+  strcpy(namebuf, slave);
+  /* Open the slave side. */
+  *ttyfd = open(namebuf, O_RDWR|O_NOCTTY);
+  if (*ttyfd < 0)
+    {
+      error("%.200s: %.100s", namebuf, strerror(errno));
+      close(*ptyfd);
+      return 0;
+    }
+  return 1;
+
+#else /* HAVE__GETPTY */
+#ifdef HAVE_DEV_PTMX
+  /* This code is used e.g. on Solaris 2.x.  (Note that Solaris 2.3 also has
+     bsd-style ptys, but they simply do not work.) */
+
+  int ptm;
+  char *pts;
+  
+  ptm = open("/dev/ptmx", O_RDWR|O_NOCTTY);
+  if (ptm < 0)
+    {
+      error("/dev/ptmx: %.100s", strerror(errno));
+      return 0;
+    }
+  if (grantpt(ptm) < 0)
+    {
+      error("grantpt: %.100s", strerror(errno));
+      return 0;
+    }
+  if (unlockpt(ptm) < 0)
+    {
+      error("unlockpt: %.100s", strerror(errno));
+      return 0;
+    }
+  pts = ptsname(ptm);
+  if (pts == NULL)
+    error("Slave pty side name could not be obtained.");
+  strcpy(namebuf, pts);
+  *ptyfd = ptm;
+
+  /* Open the slave side. */
+  *ttyfd = open(namebuf, O_RDWR|O_NOCTTY);
+  if (*ttyfd < 0)
+    {
+      error("%.100s: %.100s", namebuf, strerror(errno));
+      close(*ptyfd);
+      return 0;
+    }
+  /* Push the appropriate streams modules, as described in Solaris pts(7). */
+  if (ioctl(*ttyfd, I_PUSH, "ptem") < 0)
+    error("ioctl I_PUSH ptem: %.100s", strerror(errno));
+  if (ioctl(*ttyfd, I_PUSH, "ldterm") < 0)
+    error("ioctl I_PUSH ldterm: %.100s", strerror(errno));
+  if (ioctl(*ttyfd, I_PUSH, "ttcompat") < 0)
+    error("ioctl I_PUSH ttcompat: %.100s", strerror(errno));
+  return 1;
+
+#else /* HAVE_DEV_PTMX */
+#ifdef HAVE_DEV_PTS_AND_PTC
+
+  /* AIX-style pty code. */
+
+  const char *name;
+
+  *ptyfd = open("/dev/ptc", O_RDWR|O_NOCTTY);
+  if (*ptyfd < 0)
+    {
+      error("Could not open /dev/ptc: %.100s", strerror(errno));
+      return 0;
+    }
+  name = ttyname(*ptyfd);
+  if (!name)
+    fatal("Open of /dev/ptc returns device for which ttyname fails.");
+  strcpy(namebuf, name);
+  *ttyfd = open(name, O_RDWR|O_NOCTTY);
+  if (*ttyfd < 0)
+    {
+      error("Could not open pty slave side %.100s: %.100s", 
+	    name, strerror(errno));
+      close(*ptyfd);
+      return 0;
+    }
+  return 1;
+
+#else /* HAVE_DEV_PTS_AND_PTC */
+  /* BSD-style pty code. */
+
+  char buf[64];
+  int i;
+  const char *ptymajors = 
+    "pqrstuvwxyzabcdefghijklmnoABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  const char *ptyminors = "0123456789abcdef";
+  int num_minors = strlen(ptyminors);
+  int num_ptys = strlen(ptymajors) * num_minors;
+
+  for (i = 0; i < num_ptys; i++)
+    {
+      snprintf(buf, sizeof buf, "/dev/pty%c%c", ptymajors[i / num_minors], 
+	      ptyminors[i % num_minors]);
+      *ptyfd = open(buf, O_RDWR|O_NOCTTY);
+      if (*ptyfd < 0)
+	continue;
+      snprintf(namebuf, sizeof buf, "/dev/tty%c%c", ptymajors[i / num_minors], 
+	      ptyminors[i % num_minors]);
+
+      /* Open the slave side. */
+      *ttyfd = open(namebuf, O_RDWR|O_NOCTTY);
+      if (*ttyfd < 0)
+	{
+	  error("%.100s: %.100s", namebuf, strerror(errno));
+	  close(*ptyfd);
+	  return 0;
+	}
+      return 1;
+    }
+  return 0;
+#endif /* HAVE_DEV_PTS_AND_PTC */
+#endif /* HAVE_DEV_PTMX */
+#endif /* HAVE__GETPTY */
+#endif /* HAVE_OPENPTY */
+}
+
+/* Releases the tty.  Its ownership is returned to root, and permissions to
+   0666. */
+
+void pty_release(const char *ttyname)
+{
+  if (chown(ttyname, (uid_t)0, (gid_t)0) < 0)
+    debug("chown %.100s 0 0 failed: %.100s", ttyname, strerror(errno));
+  if (chmod(ttyname, (mode_t)0666) < 0)
+    debug("chmod %.100s 0666 failed: %.100s", ttyname, strerror(errno));
+}
+
+/* Makes the tty the processes controlling tty and sets it to sane modes. */
+
+void pty_make_controlling_tty(int *ttyfd, const char *ttyname)
+{
+  int fd;
+
+  /* First disconnect from the old controlling tty. */
+#ifdef TIOCNOTTY
+  fd = open("/dev/tty", O_RDWR|O_NOCTTY);
+  if (fd >= 0)
+    {
+      (void)ioctl(fd, TIOCNOTTY, NULL);
+      close(fd);
+    }
+#endif /* TIOCNOTTY */
+  if (setsid() < 0)
+    error("setsid: %.100s", strerror(errno));
+  
+  /* Verify that we are successfully disconnected from the controlling tty. */
+  fd = open("/dev/tty", O_RDWR|O_NOCTTY);
+  if (fd >= 0)
+    {
+      error("Failed to disconnect from controlling tty.");
+      close(fd);
+    }
+
+  /* Make it our controlling tty. */
+#ifdef TIOCSCTTY
+  debug("Setting controlling tty using TIOCSCTTY.");
+  /* We ignore errors from this, because HPSUX defines TIOCSCTTY, but returns
+     EINVAL with these arguments, and there is absolutely no documentation. */
+  ioctl(*ttyfd, TIOCSCTTY, NULL);
+#endif /* TIOCSCTTY */
+  fd = open(ttyname, O_RDWR);
+  if (fd < 0)
+    error("%.100s: %.100s", ttyname, strerror(errno));
+  else
+    close(fd);
+
+  /* Verify that we now have a controlling tty. */
+  fd = open("/dev/tty", O_WRONLY);
+  if (fd < 0)
+    error("open /dev/tty failed - could not set controlling tty: %.100s",
+	  strerror(errno));
+  else
+    {
+      close(fd);
+    }
+}
+
+/* Changes the window size associated with the pty. */
+
+void pty_change_window_size(int ptyfd, int row, int col,
+			    int xpixel, int ypixel)
+{
+  struct winsize w;
+  w.ws_row = row;
+  w.ws_col = col;
+  w.ws_xpixel = xpixel;  
+  w.ws_ypixel = ypixel;
+  (void)ioctl(ptyfd, TIOCSWINSZ, &w);
+}
+