popen.c revision 1.7 
1/*	$OpenBSD: popen.c,v 1.7 1996/10/25 23:59:18 imp 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		} else
113			for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV-1; pop++)
114				gargv[gargc++] = strdup(*pop);
115		globfree(&gl);
116	}
117	gargv[gargc] = NULL;
118
119	iop = NULL;
120	switch(pid = vfork()) {
121	case -1:			/* error */
122		(void)close(pdes[0]);
123		(void)close(pdes[1]);
124		goto pfree;
125		/* NOTREACHED */
126	case 0:				/* child */
127		if (*type == 'r') {
128			if (pdes[1] != STDOUT_FILENO) {
129				dup2(pdes[1], STDOUT_FILENO);
130				(void)close(pdes[1]);
131			}
132			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
133			(void)close(pdes[0]);
134		} else {
135			if (pdes[0] != STDIN_FILENO) {
136				dup2(pdes[0], STDIN_FILENO);
137				(void)close(pdes[0]);
138			}
139			(void)close(pdes[1]);
140		}
141		closelog();
142
143		execv(gargv[0], gargv);
144		_exit(1);
145	}
146	/* parent; assume fdopen can't fail...  */
147	if (*type == 'r') {
148		iop = fdopen(pdes[0], type);
149		(void)close(pdes[1]);
150	} else {
151		iop = fdopen(pdes[1], type);
152		(void)close(pdes[0]);
153	}
154	pids[fileno(iop)] = pid;
155
156pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
157		free(gargv[argc]);
158
159	return (iop);
160}
161
162int
163ftpd_pclose(iop)
164	FILE *iop;
165{
166	int fdes, omask, status;
167	pid_t pid;
168	sigset_t sigset, osigset;
169
170	/*
171	 * pclose returns -1 if stream is not associated with a
172	 * `popened' command, or, if already `pclosed'.
173	 */
174	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
175		return (-1);
176	(void)fclose(iop);
177	sigemptyset(&sigset);
178	sigaddset(&sigset, SIGINT);
179	sigaddset(&sigset, SIGQUIT);
180	sigaddset(&sigset, SIGHUP);
181	sigprocmask(SIG_BLOCK, &sigset, &osigset);
182	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
183		continue;
184	sigprocmask(SIG_SETMASK, &osigset, NULL);
185	pids[fdes] = 0;
186	if (pid < 0)
187		return (pid);
188	if (WIFEXITED(status))
189		return (WEXITSTATUS(status));
190	return (1);
191}
192