xref: /netbsd-src/libexec/ftpd/popen.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: popen.c,v 1.27 2001/12/01 10:25:30 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999-2001 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 1.27 2001/12/01 10:25:30 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 *ptype, 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 ((*ptype != 'r' && *ptype != 'w') || ptype[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|GLOB_LIMIT;
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 				globfree(&gl);
156 				goto pfree;
157 			}
158 		} else {
159 			for (pop = gl.gl_pathv; *pop; pop++) {
160 				if (sl_add(sl, xstrdup(*pop)) == -1) {
161 					globfree(&gl);
162 					goto pfree;
163 				}
164 			}
165 		}
166 		globfree(&gl);
167 	}
168 	if (sl_add(sl, NULL) == -1)
169 		goto pfree;
170 
171 #ifndef NO_INTERNAL_LS
172 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
173 #endif
174 
175 	pid = isls ? fork() : vfork();
176 	switch (pid) {
177 	case -1:			/* error */
178 		(void)close(pdes[0]);
179 		(void)close(pdes[1]);
180 		goto pfree;
181 		/* NOTREACHED */
182 	case 0:				/* child */
183 		if (*ptype == 'r') {
184 			if (pdes[1] != STDOUT_FILENO) {
185 				dup2(pdes[1], STDOUT_FILENO);
186 				(void)close(pdes[1]);
187 			}
188 			if (stderrfd == -1)
189 				(void)close(STDERR_FILENO);
190 			else
191 				dup2(stderrfd, STDERR_FILENO);
192 			(void)close(pdes[0]);
193 		} else {
194 			if (pdes[0] != STDIN_FILENO) {
195 				dup2(pdes[0], STDIN_FILENO);
196 				(void)close(pdes[0]);
197 			}
198 			(void)close(pdes[1]);
199 		}
200 #ifndef NO_INTERNAL_LS
201 		if (isls) {	/* use internal ls */
202 			optreset = optind = optopt = 1;
203 			closelog();
204 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
205 		}
206 #endif
207 
208 		execv(sl->sl_str[0], sl->sl_str);
209 		_exit(1);
210 	}
211 	/* parent; assume fdopen can't fail...  */
212 	if (*ptype == 'r') {
213 		iop = fdopen(pdes[0], ptype);
214 		(void)close(pdes[1]);
215 	} else {
216 		iop = fdopen(pdes[1], ptype);
217 		(void)close(pdes[0]);
218 	}
219 	pids[fileno(iop)] = pid;
220 
221  pfree:
222 	if (sl)
223 		sl_free(sl, 1);
224 	return (iop);
225 }
226 
227 int
228 ftpd_pclose(FILE *iop)
229 {
230 	int fdes, status;
231 	pid_t pid;
232 	sigset_t sigset, osigset;
233 
234 	/*
235 	 * pclose returns -1 if stream is not associated with a
236 	 * `popened' command, or, if already `pclosed'.
237 	 */
238 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
239 		return (-1);
240 	(void)fclose(iop);
241 	sigemptyset(&sigset);
242 	sigaddset(&sigset, SIGINT);
243 	sigaddset(&sigset, SIGQUIT);
244 	sigaddset(&sigset, SIGHUP);
245 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
246 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
247 		continue;
248 	sigprocmask(SIG_SETMASK, &osigset, NULL);
249 	pids[fdes] = 0;
250 	if (pid < 0)
251 		return (pid);
252 	if (WIFEXITED(status))
253 		return (WEXITSTATUS(status));
254 	return (1);
255 }
256