1/*
2 * Copyright (c) 2010, Oracle America, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 * * Neither the name of the "Oracle America, Inc." nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
25 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * Open two pipes to a child process, one for reading, one for writing.
34 * The pipes are accessed by FILE pointers. This is NOT a public
35 * interface, but for internal use only!
36 */
37#include <stdio.h>
38#include <stdlib.h>
39#include <unistd.h>
40#include <string.h>
41#include <rpc/rpc.h>
42#include <rpc/clnt.h>
43
44#include <libio/iolibio.h>
45#define fflush(s) _IO_fflush (s)
46#define __fdopen(fd,m) _IO_fdopen (fd,m)
47
48/*
49 * returns pid, or -1 for failure
50 */
51int
52_openchild (const char *command, FILE ** fto, FILE ** ffrom)
53{
54 int i;
55 int pid;
56 int pdto[2];
57 int pdfrom[2];
58
59 if (__pipe (pdto) < 0)
60 goto error1;
61 if (__pipe (pdfrom) < 0)
62 goto error2;
63 switch (pid = __fork ())
64 {
65 case -1:
66 goto error3;
67
68 case 0:
69 /*
70 * child: read from pdto[0], write into pdfrom[1]
71 */
72 __close (0);
73 __dup (pdto[0]);
74 __close (1);
75 __dup (pdfrom[1]);
76 fflush (stderr);
77 for (i = _rpc_dtablesize () - 1; i >= 3; i--)
78 __close (i);
79 fflush (stderr);
80 execlp (command, command, NULL);
81 perror ("exec");
82 _exit (~0);
83
84 default:
85 /*
86 * parent: write into pdto[1], read from pdfrom[0]
87 */
88 *fto = __fdopen (pdto[1], "w");
89 __close (pdto[0]);
90 *ffrom = __fdopen (pdfrom[0], "r");
91 __close (pdfrom[1]);
92 break;
93 }
94 return pid;
95
96 /*
97 * error cleanup and return
98 */
99error3:
100 __close (pdfrom[0]);
101 __close (pdfrom[1]);
102error2:
103 __close (pdto[0]);
104 __close (pdto[1]);
105error1:
106 return -1;
107}
108