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-rw-r--r--sysdeps/mach/hurd/dup2.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/dup2.c b/sysdeps/mach/hurd/dup2.c
new file mode 100644
index 0000000000..f4ec623b05
--- /dev/null
+++ b/sysdeps/mach/hurd/dup2.c
@@ -0,0 +1,114 @@
+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <hurd.h>
+#include <hurd/fd.h>
+
+
+/* Duplicate FD to FD2, closing the old FD2 and making FD2 be
+   open on the same file as FD is.  Return FD2 or -1.  */
+int
+DEFUN(__dup2, (fd, fd2), int fd AND int fd2)
+{
+  struct hurd_fd *d;
+
+  /* Extract the ports and flags from FD.  */
+  d = _hurd_fd_get (fd);
+  if (d == NULL)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  HURD_CRITICAL_BEGIN;
+
+  __spin_lock (&d->port.lock);
+  if (d->port.port == MACH_PORT_NULL)
+    {
+      __spin_unlock (&d->port.lock);
+      errno = EBADF;
+      fd2 = -1;
+    }
+  else if (fd2 == fd)
+    /* FD is valid and FD2 is already the same; just return it.  */
+    __spin_unlock (&d->port.lock);
+  else
+    {
+      struct hurd_userlink ulink, ctty_ulink;
+      int flags = d->flags;
+      io_t ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
+      io_t port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D.  */
+
+      __mutex_lock (&_hurd_dtable_lock);
+      if (fd2 < 0 || fd2 >= _hurd_dtablesize)
+	{
+	  errno = EBADF;
+	  fd2 = -1;
+	}
+      else
+	{
+	  /* Get a hold of the destination descriptor.  */
+	  struct hurd_fd *d2 = _hurd_dtable[fd2];
+	  if (d2 == NULL)
+	    {
+	      /* Must allocate a new one.  We don't initialize the port cells
+		 with this call so that if it fails (out of memory), we will
+		 not have already added user references for the ports, which we
+		 would then have to deallocate.  */
+	      d2 = _hurd_dtable[fd2] = _hurd_new_fd (MACH_PORT_NULL,
+						     MACH_PORT_NULL);
+	    }
+	  if (d2 == NULL)
+	    {
+	      fd2 = -1;
+	      if (errno == EINVAL)
+		errno = EBADF;	/* POSIX.1-1990 6.2.1.2 ll 54-55.  */
+	    }
+	  else
+	    {
+	      /* Give the ports each a user ref for the new descriptor.  */
+	      __mach_port_mod_refs (__mach_task_self (), port,
+				    MACH_PORT_RIGHT_SEND, 1);
+	      if (ctty != MACH_PORT_NULL)
+		__mach_port_mod_refs (__mach_task_self (), ctty,
+				      MACH_PORT_RIGHT_SEND, 1);
+
+	      /* Install the ports and flags in the new descriptor slot.  */
+	      __spin_lock (&d2->port.lock);
+	      d2->flags = flags & ~FD_CLOEXEC; /* Dup clears FD_CLOEXEC. */
+	      _hurd_port_set (&d2->ctty, ctty);
+	      _hurd_port_locked_set (&d2->port, port); /* Unlocks D2.  */
+	    }
+	}
+      __mutex_unlock (&_hurd_dtable_lock);
+
+      _hurd_port_free (&d->port, &ulink, port);
+      if (ctty != MACH_PORT_NULL)
+	_hurd_port_free (&d->ctty, &ctty_ulink, port);
+    }
+
+  HURD_CRITICAL_END;
+
+  return fd2;
+}
+
+weak_alias (__dup2, dup2)