NetBSD/bin/sh/redir.h
christos d18385a5a2 Don't leak redirected rescriptors to exec'ed processes. This is what ksh
does, but bash does not. For example:

    $ cat test1
    #!/bin/sh
    exec 6> out
    echo "test" >&6
    sh ./test2
    exec 6>&-
    $ cat test2
    echo "test2" >&6
    $ ./test1
    ./test2: 6: Bad file descriptor

This fixes by side effect the problem of the rc system leaking file descriptors
7 and 8 to all starting daemons:

    $ fstat -p 1359
    USER     CMD          PID   FD MOUNT       INUM MODE         SZ|DV R/W
    root     powerd      1359   wd /              2 drwxr-xr-x     512 r
    root     powerd      1359    0 /          63029 crw-rw-rw-    null rw
    root     powerd      1359    1 /          63029 crw-rw-rw-    null rw
    root     powerd      1359    2 /          63029 crw-rw-rw-    null rw
    root     powerd      1359    3* kqueue pending 0
    root     powerd      1359    4 /          64463 crw-r-----   power r
    root     powerd      1359    7 flags 0x80034<ISTTY,MPSAFE,LOCKSWORK,CLEAN>
    root     powerd      1359    8 flags 0x80034<ISTTY,MPSAFE,LOCKSWORK,CLEAN>
    root     powerd      1359    9* pipe 0xfffffe815d7bfdc0 -> 0x0 w

Note fd=7,8 pointing to the revoked pty from the parent rc process.
2016-01-04 03:00:24 +00:00

49 lines
2.1 KiB
C

/* $NetBSD: redir.h,v 1.17 2016/01/04 03:00:24 christos Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)redir.h 8.2 (Berkeley) 5/4/95
*/
/* flags passed to redirect */
#define REDIR_PUSH 01 /* save previous values of file descriptors */
#define REDIR_BACKQ 02 /* save the command output in memory */
#define REDIR_VFORK 04 /* running under vfork(2), be careful */
union node;
void redirect(union node *, int);
void popredir(void);
int fd0_redirected_p(void);
void clearredir(int);
int copyfd(int, int, int, int);