[src/trunk]: src/bin/sh Ensure that fd 0, 1 and 2 are not used for the local ...

[dsl <dsl%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ea3ab920526f
branches:  trunk
changeset: 566189:ea3ab920526f
user:      dsl <dsl%NetBSD.org@localhost>
date:      Fri Apr 30 06:27:59 2004 +0000

description:
Ensure that fd 0, 1 and 2 are not used for the local end of pipelines.
Fixes PR bin/25395

diffstat:

 bin/sh/eval.c |  36 +++++++++++++++++++++++++++++++-----
 1 files changed, 31 insertions(+), 5 deletions(-)

diffs (85 lines):

diff -r 381b8fa8611c -r ea3ab920526f bin/sh/eval.c
--- a/bin/sh/eval.c     Fri Apr 30 05:14:23 2004 +0000
+++ b/bin/sh/eval.c     Fri Apr 30 06:27:59 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: eval.c,v 1.75 2003/11/14 10:27:10 dsl Exp $    */
+/*     $NetBSD: eval.c,v 1.76 2004/04/30 06:27:59 dsl Exp $    */
 
 /*-
  * Copyright (c) 1993
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)eval.c     8.9 (Berkeley) 6/8/95";
 #else
-__RCSID("$NetBSD: eval.c,v 1.75 2003/11/14 10:27:10 dsl Exp $");
+__RCSID("$NetBSD: eval.c,v 1.76 2004/04/30 06:27:59 dsl Exp $");
 #endif
 #endif /* not lint */
 
@@ -45,6 +45,7 @@
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
+#include <sys/fcntl.h>
 #include <sys/times.h>
 #include <sys/param.h>
 #include <sys/types.h>
@@ -125,6 +126,31 @@
 }
 #endif
 
+static int
+sh_pipe(int fds[2])
+{
+       int nfd;
+
+       if (pipe(fds))
+               return -1;
+
+       if (fds[0] < 3) {
+               nfd = fcntl(fds[0], F_DUPFD, 3);
+               if (nfd != -1) {
+                       close(fds[0]);
+                       fds[0] = nfd;
+               }
+       }
+
+       if (fds[1] < 3) {
+               nfd = fcntl(fds[1], F_DUPFD, 3);
+               if (nfd != -1) {
+                       close(fds[1]);
+                       fds[1] = nfd;
+               }
+       }
+       return 0;
+}
 
 
 /*
@@ -476,7 +502,7 @@
                prehash(lp->n);
                pip[1] = -1;
                if (lp->next) {
-                       if (pipe(pip) < 0) {
+                       if (sh_pipe(pip) < 0) {
                                close(prevfd);
                                error("Pipe call failed");
                        }
@@ -548,7 +574,7 @@
 #endif
        {
                INTOFF;
-               if (pipe(pip) < 0)
+               if (sh_pipe(pip) < 0)
                        error("Pipe call failed");
                jp = makejob(n, 1);
                if (forkshell(jp, n, FORK_NOJOB) == 0) {
@@ -800,7 +826,7 @@
                mode = cmd->ncmd.backgnd;
                if (flags & EV_BACKCMD) {
                        mode = FORK_NOJOB;
-                       if (pipe(pip) < 0)
+                       if (sh_pipe(pip) < 0)
                                error("Pipe call failed");
                }
 #ifdef DO_SHAREDVFORK