popen.c revision 1.9 
1/*	$OpenBSD: popen.c,v 1.9 1997/06/29 07:35:48 deraadt Exp $	*/
2/*	$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $	*/
3
4/*
5 * Copyright (c) 1988, 1993, 1994
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * This code is derived from software written by Ken Arnold and
9 * published in UNIX Review, Vol. 6, No. 8.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the University of
22 *	California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 */
40
41#ifndef lint
42#if 0
43static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
44#else
45static char rcsid[] = "$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $";
46#endif
47#endif /* not lint */
48
49#include <sys/types.h>
50#include <sys/wait.h>
51
52#include <errno.h>
53#include <glob.h>
54#include <signal.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <syslog.h>
59#include <unistd.h>
60
61#include "extern.h"
62
63/*
64 * Special version of popen which avoids call to shell.  This ensures noone
65 * may create a pipe to a hidden program as a side effect of a list or dir
66 * command.
67 */
68static int *pids;
69static int fds;
70
71#define MAX_ARGV	100
72#define MAX_GARGV	1000
73
74FILE *
75ftpd_popen(program, type)
76	char *program, *type;
77{
78	char *cp;
79	FILE *iop;
80	int argc, gargc, pdes[2], pid;
81	char **pop, *argv[MAX_ARGV], *gargv[MAX_GARGV];
82
83	if ((*type != 'r' && *type != 'w') || type[1])
84		return (NULL);
85
86	if (!pids) {
87		if ((fds = getdtablesize()) <= 0)
88			return (NULL);
89		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
90			return (NULL);
91		memset(pids, 0, fds * sizeof(int));
92	}
93	if (pipe(pdes) < 0)
94		return (NULL);
95
96	/* break up string into pieces */
97	for (argc = 0, cp = program;argc < MAX_ARGV-1; cp = NULL)
98		if (!(argv[argc++] = strtok(cp, " \t\n")))
99			break;
100	argv[MAX_ARGV-1] = NULL;
101
102	/* glob each piece */
103	gargv[0] = argv[0];
104	for (gargc = argc = 1; argv[argc]; argc++) {
105		glob_t gl;
106		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
107
108		memset(&gl, 0, sizeof(gl));
109		if (glob(argv[argc], flags, NULL, &gl)) {
110			if (gargc < MAX_GARGV-1) {
111				gargv[gargc++] = strdup(argv[argc]);
112				if (gargv[gargc -1] == NULL)
113					fatal ("Out of memory");
114			}
115
116		} else
117			for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV-1; pop++) {
118				gargv[gargc++] = strdup(*pop);
119				if (gargv[gargc - 1] == NULL)
120					fatal ("Out of memory");
121			}
122		globfree(&gl);
123	}
124	gargv[gargc] = NULL;
125
126	iop = NULL;
127	switch(pid = vfork()) {
128	case -1:			/* error */
129		(void)close(pdes[0]);
130		(void)close(pdes[1]);
131		goto pfree;
132		/* NOTREACHED */
133	case 0:				/* child */
134		if (*type == 'r') {
135			if (pdes[1] != STDOUT_FILENO) {
136				dup2(pdes[1], STDOUT_FILENO);
137				(void)close(pdes[1]);
138			}
139			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
140			(void)close(pdes[0]);
141		} else {
142			if (pdes[0] != STDIN_FILENO) {
143				dup2(pdes[0], STDIN_FILENO);
144				(void)close(pdes[0]);
145			}
146			(void)close(pdes[1]);
147		}
148		closelog();
149
150		execv(gargv[0], gargv);
151		_exit(1);
152	}
153	/* parent; assume fdopen can't fail...  */
154	if (*type == 'r') {
155		iop = fdopen(pdes[0], type);
156		(void)close(pdes[1]);
157	} else {
158		iop = fdopen(pdes[1], type);
159		(void)close(pdes[0]);
160	}
161	pids[fileno(iop)] = pid;
162
163pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
164		free(gargv[argc]);
165
166	return (iop);
167}
168
169int
170ftpd_pclose(iop)
171	FILE *iop;
172{
173	int fdes, status;
174	pid_t pid;
175	sigset_t sigset, osigset;
176
177	/*
178	 * pclose returns -1 if stream is not associated with a
179	 * `popened' command, or, if already `pclosed'.
180	 */
181	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
182		return (-1);
183	(void)fclose(iop);
184	sigemptyset(&sigset);
185	sigaddset(&sigset, SIGINT);
186	sigaddset(&sigset, SIGQUIT);
187	sigaddset(&sigset, SIGHUP);
188	sigprocmask(SIG_BLOCK, &sigset, &osigset);
189	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
190		continue;
191	sigprocmask(SIG_SETMASK, &osigset, NULL);
192	pids[fdes] = 0;
193	if (pid < 0)
194		return (pid);
195	if (WIFEXITED(status))
196		return (WEXITSTATUS(status));
197	return (1);
198}
199