popen.c revision 1.3 
1/*	$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software written by Ken Arnold and
8 * published in UNIX Review, Vol. 6, No. 8.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 */
39
40#ifndef lint
41#if 0
42static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
43#else
44static char rcsid[] = "$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $";
45#endif
46#endif /* not lint */
47
48#include <sys/types.h>
49#include <sys/wait.h>
50
51#include <errno.h>
52#include <glob.h>
53#include <signal.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <syslog.h>
58#include <unistd.h>
59
60#include "extern.h"
61
62/*
63 * Special version of popen which avoids call to shell.  This ensures noone
64 * may create a pipe to a hidden program as a side effect of a list or dir
65 * command.
66 */
67static int *pids;
68static int fds;
69
70FILE *
71ftpd_popen(program, type)
72	char *program, *type;
73{
74	char *cp;
75	FILE *iop;
76	int argc, gargc, pdes[2], pid;
77	char **pop, *argv[100], *gargv[1000];
78
79	if (*type != 'r' && *type != 'w' || type[1])
80		return (NULL);
81
82	if (!pids) {
83		if ((fds = getdtablesize()) <= 0)
84			return (NULL);
85		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
86			return (NULL);
87		memset(pids, 0, fds * sizeof(int));
88	}
89	if (pipe(pdes) < 0)
90		return (NULL);
91
92	/* break up string into pieces */
93	for (argc = 0, cp = program;argc < 100; cp = NULL)
94		if (!(argv[argc++] = strtok(cp, " \t\n")))
95			break;
96
97	/* glob each piece */
98	gargv[0] = argv[0];
99	for (gargc = argc = 1; argv[argc]; argc++) {
100		glob_t gl;
101		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
102
103		memset(&gl, 0, sizeof(gl));
104		if (glob(argv[argc], flags, NULL, &gl))
105			gargv[gargc++] = strdup(argv[argc]);
106		else
107			for (pop = gl.gl_pathv; *pop && gargc < 1000; pop++)
108				gargv[gargc++] = strdup(*pop);
109		globfree(&gl);
110	}
111	gargv[gargc] = NULL;
112
113	iop = NULL;
114	switch(pid = vfork()) {
115	case -1:			/* error */
116		(void)close(pdes[0]);
117		(void)close(pdes[1]);
118		goto pfree;
119		/* NOTREACHED */
120	case 0:				/* child */
121		if (*type == 'r') {
122			if (pdes[1] != STDOUT_FILENO) {
123				dup2(pdes[1], STDOUT_FILENO);
124				(void)close(pdes[1]);
125			}
126			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
127			(void)close(pdes[0]);
128		} else {
129			if (pdes[0] != STDIN_FILENO) {
130				dup2(pdes[0], STDIN_FILENO);
131				(void)close(pdes[0]);
132			}
133			(void)close(pdes[1]);
134		}
135		closelog();
136
137		execv(gargv[0], gargv);
138		_exit(1);
139	}
140	/* parent; assume fdopen can't fail...  */
141	if (*type == 'r') {
142		iop = fdopen(pdes[0], type);
143		(void)close(pdes[1]);
144	} else {
145		iop = fdopen(pdes[1], type);
146		(void)close(pdes[0]);
147	}
148	pids[fileno(iop)] = pid;
149
150pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
151		free(gargv[argc]);
152
153	return (iop);
154}
155
156int
157ftpd_pclose(iop)
158	FILE *iop;
159{
160	int fdes, omask, status;
161	pid_t pid;
162	sigset_t sigset, osigset;
163
164	/*
165	 * pclose returns -1 if stream is not associated with a
166	 * `popened' command, or, if already `pclosed'.
167	 */
168	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
169		return (-1);
170	(void)fclose(iop);
171	sigemptyset(&sigset);
172	sigaddset(&sigset, SIGINT);
173	sigaddset(&sigset, SIGQUIT);
174	sigaddset(&sigset, SIGHUP);
175	sigprocmask(SIG_BLOCK, &sigset, &osigset);
176	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
177		continue;
178	sigprocmask(SIG_SETMASK, &osigset, NULL);
179	pids[fdes] = 0;
180	if (pid < 0)
181		return (pid);
182	if (WIFEXITED(status))
183		return (WEXITSTATUS(status));
184	return (1);
185}
186