lib/libc_r/uthread/uthread_dup2.c

   1 /*
   2  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
   3  * 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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc_r/uthread/uthread_dup2.c,v 1.9.2.7 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_dup2.c,v 1.2 2003/06/17 04:26:48 dillon Exp $
  34  */
  35 #include <errno.h>
  36 #include <unistd.h>
  37 #include <pthread.h>
  38 #include "pthread_private.h"
  39
  40 int
  41 _dup2(int fd, int newfd)
  42 {
  43         int             ret;
  44         int             newfd_opened;
  45
  46         /* Check if the file descriptor is out of range: */
  47         if (newfd < 0 || newfd >= _thread_dtablesize ||
  48             newfd == _thread_kern_pipe[0] || newfd == _thread_kern_pipe[1]) {
  49                 /* Return a bad file descriptor error: */
  50                 errno = EBADF;
  51                 ret = -1;
  52         }
  53
  54         /* Lock the file descriptor: */
  55         else if ((ret = _FD_LOCK(fd, FD_RDWR, NULL)) == 0) {
  56                 /* Lock the file descriptor: */
  57                 if (!(newfd_opened = (_thread_fd_table[newfd] != NULL)) ||
  58                     (ret = _FD_LOCK(newfd, FD_RDWR, NULL)) == 0) {
  59                         /* Perform the 'dup2' syscall: */
  60                         ret = __sys_dup2(fd, newfd);
  61                         if (ret >= 0) {
  62                                 /*
  63                                  * If we are duplicating one of the standard
  64                                  * file descriptors, update its flags in the
  65                                  * table of pthread stdio descriptor flags.
  66                                  */
  67                                 if (ret < 3) {
  68                                         _pthread_stdio_flags[ret] =
  69                                             _thread_fd_table[fd]->flags;
  70                                 }
  71                                 /* Initialise the file descriptor table entry */
  72                                 if (_thread_fd_table_init(ret) != 0) {
  73                                         /* Quietly close the file: */
  74                                         __sys_close(ret);
  75
  76                                         /* Reset the file descriptor: */
  77                                         ret = -1;
  78                                 } else {
  79                                         /*
  80                                          * Save the file open flags so that
  81                                          * they can be checked later:
  82                                          */
  83                                         _thread_fd_setflags(ret,
  84                                             _thread_fd_getflags(fd));
  85                                 }
  86                         }
  87
  88                         /* Unlock the file descriptor: */
  89                         if (newfd_opened)
  90                                 _FD_UNLOCK(newfd, FD_RDWR);
  91                 }
  92                 /* Unlock the file descriptor: */
  93                 _FD_UNLOCK(fd, FD_RDWR);
  94         }
  95         /* Return the completion status: */
  96         return (ret);
  97 }
  98
  99 __strong_reference(_dup2, dup2);