xref: /netbsd-src/libexec/ftpd/popen.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: popen.c,v 1.22 2000/05/20 23:34:55 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Luke Mewburn.
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 NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (c) 1988, 1993, 1994
41  *	The Regents of the University of California.  All rights reserved.
42  *
43  * This code is derived from software written by Ken Arnold and
44  * published in UNIX Review, Vol. 6, No. 8.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. All advertising materials mentioning features or use of this software
55  *    must display the following acknowledgement:
56  *	This product includes software developed by the University of
57  *	California, Berkeley and its contributors.
58  * 4. Neither the name of the University nor the names of its contributors
59  *    may be used to endorse or promote products derived from this software
60  *    without specific prior written permission.
61  *
62  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
63  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
64  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
65  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
66  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
67  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
68  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
69  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
70  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
71  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
72  * SUCH DAMAGE.
73  *
74  */
75 
76 #include <sys/cdefs.h>
77 #ifndef lint
78 #if 0
79 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
80 #else
81 __RCSID("$NetBSD: popen.c,v 1.22 2000/05/20 23:34:55 lukem Exp $");
82 #endif
83 #endif /* not lint */
84 
85 #include <sys/types.h>
86 #include <sys/param.h>
87 #include <sys/wait.h>
88 
89 #include <errno.h>
90 #include <glob.h>
91 #include <setjmp.h>
92 #include <signal.h>
93 #include <stdio.h>
94 #include <stdlib.h>
95 #include <string.h>
96 #include <stringlist.h>
97 #include <syslog.h>
98 #include <unistd.h>
99 
100 #ifdef KERBEROS5
101 #include <krb5/krb5.h>
102 #endif
103 
104 #include "extern.h"
105 
106 #define INCR	100
107 /*
108  * Special version of popen which avoids call to shell.  This ensures no-one
109  * may create a pipe to a hidden program as a side effect of a list or dir
110  * command.
111  * If stderrfd != -1, then send stderr of a read command there,
112  * otherwise close stderr.
113  */
114 static int *pids;
115 static int fds;
116 
117 extern int ls_main(int, char *[]);
118 
119 FILE *
120 ftpd_popen(char *argv[], const char *type, int stderrfd)
121 {
122 	FILE *iop;
123 	int argc, pdes[2], pid, isls;
124 	char **pop;
125 	StringList *sl;
126 
127 	iop = NULL;
128 	isls = 0;
129 	if ((*type != 'r' && *type != 'w') || type[1])
130 		return (NULL);
131 
132 	if (!pids) {
133 		if ((fds = getdtablesize()) <= 0)
134 			return (NULL);
135 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
136 			return (NULL);
137 		memset(pids, 0, fds * sizeof(int));
138 	}
139 	if (pipe(pdes) < 0)
140 		return (NULL);
141 
142 	if ((sl = sl_init()) == NULL)
143 		goto pfree;
144 
145 					/* glob each piece */
146 	if (sl_add(sl, xstrdup(argv[0])) == -1)
147 		goto pfree;
148 	for (argc = 1; argv[argc]; argc++) {
149 		glob_t gl;
150 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
151 
152 		memset(&gl, 0, sizeof(gl));
153 		if (glob(argv[argc], flags, NULL, &gl)) {
154 			if (sl_add(sl, xstrdup(argv[argc])) == -1)
155 				goto pfree;
156 		} else
157 			for (pop = gl.gl_pathv; *pop; pop++) {
158 				if (sl_add(sl, xstrdup(*pop)) == -1)
159 					goto pfree;
160 			}
161 		globfree(&gl);
162 	}
163 	if (sl_add(sl, NULL) == -1)
164 		goto pfree;
165 
166 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
167 
168 	pid = isls ? fork() : vfork();
169 	switch (pid) {
170 	case -1:			/* error */
171 		(void)close(pdes[0]);
172 		(void)close(pdes[1]);
173 		goto pfree;
174 		/* NOTREACHED */
175 	case 0:				/* child */
176 		if (*type == 'r') {
177 			if (pdes[1] != STDOUT_FILENO) {
178 				dup2(pdes[1], STDOUT_FILENO);
179 				(void)close(pdes[1]);
180 			}
181 			if (stderrfd == -1)
182 				(void)close(STDERR_FILENO);
183 			else
184 				dup2(stderrfd, STDERR_FILENO);
185 			(void)close(pdes[0]);
186 		} else {
187 			if (pdes[0] != STDIN_FILENO) {
188 				dup2(pdes[0], STDIN_FILENO);
189 				(void)close(pdes[0]);
190 			}
191 			(void)close(pdes[1]);
192 		}
193 		if (isls) {	/* use internal ls */
194 			optreset = optind = optopt = 1;
195 			closelog();
196 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
197 		}
198 		execv(sl->sl_str[0], sl->sl_str);
199 		_exit(1);
200 	}
201 	/* parent; assume fdopen can't fail...  */
202 	if (*type == 'r') {
203 		iop = fdopen(pdes[0], type);
204 		(void)close(pdes[1]);
205 	} else {
206 		iop = fdopen(pdes[1], type);
207 		(void)close(pdes[0]);
208 	}
209 	pids[fileno(iop)] = pid;
210 
211  pfree:
212 	if (sl)
213 		sl_free(sl, 1);
214 	return (iop);
215 }
216 
217 int
218 ftpd_pclose(FILE *iop)
219 {
220 	int fdes, status;
221 	pid_t pid;
222 	sigset_t sigset, osigset;
223 
224 	/*
225 	 * pclose returns -1 if stream is not associated with a
226 	 * `popened' command, or, if already `pclosed'.
227 	 */
228 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
229 		return (-1);
230 	(void)fclose(iop);
231 	sigemptyset(&sigset);
232 	sigaddset(&sigset, SIGINT);
233 	sigaddset(&sigset, SIGQUIT);
234 	sigaddset(&sigset, SIGHUP);
235 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
236 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
237 		continue;
238 	sigprocmask(SIG_SETMASK, &osigset, NULL);
239 	pids[fdes] = 0;
240 	if (pid < 0)
241 		return (pid);
242 	if (WIFEXITED(status))
243 		return (WEXITSTATUS(status));
244 	return (1);
245 }
246