xref: /netbsd-src/libexec/ftpd/popen.c (revision 4b896b232495b7a9b8b94a1cf1e21873296d53b8)
1 /*	$NetBSD: popen.c,v 1.29 2003/08/07 09:46:40 agc 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. Neither the name of the University nor the names of its contributors
55  *    may be used to endorse or promote products derived from this software
56  *    without specific prior written permission.
57  *
58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68  * SUCH DAMAGE.
69  *
70  */
71 
72 #include <sys/cdefs.h>
73 #ifndef lint
74 #if 0
75 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
76 #else
77 __RCSID("$NetBSD: popen.c,v 1.29 2003/08/07 09:46:40 agc Exp $");
78 #endif
79 #endif /* not lint */
80 
81 #include <sys/types.h>
82 #include <sys/param.h>
83 #include <sys/wait.h>
84 
85 #include <errno.h>
86 #include <glob.h>
87 #include <setjmp.h>
88 #include <signal.h>
89 #include <stdio.h>
90 #include <stdlib.h>
91 #include <string.h>
92 #include <stringlist.h>
93 #include <syslog.h>
94 #include <unistd.h>
95 
96 #ifdef KERBEROS5
97 #include <krb5/krb5.h>
98 #endif
99 
100 #include "extern.h"
101 
102 #define INCR	100
103 /*
104  * Special version of popen which avoids call to shell.  This ensures no-one
105  * may create a pipe to a hidden program as a side effect of a list or dir
106  * command.
107  * If stderrfd != -1, then send stderr of a read command there,
108  * otherwise close stderr.
109  */
110 static int *pids;
111 static int fds;
112 
113 extern int ls_main(int, char *[]);
114 
115 FILE *
116 ftpd_popen(char *argv[], const char *ptype, int stderrfd)
117 {
118 	FILE *iop;
119 	int argc, pdes[2], pid, isls;
120 	char **pop;
121 	StringList *sl;
122 
123 	iop = NULL;
124 	isls = 0;
125 	if ((*ptype != 'r' && *ptype != 'w') || ptype[1])
126 		return (NULL);
127 
128 	if (!pids) {
129 		if ((fds = getdtablesize()) <= 0)
130 			return (NULL);
131 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
132 			return (NULL);
133 		memset(pids, 0, fds * sizeof(int));
134 	}
135 	if (pipe(pdes) < 0)
136 		return (NULL);
137 
138 	if ((sl = sl_init()) == NULL)
139 		goto pfree;
140 
141 					/* glob each piece */
142 	if (sl_add(sl, xstrdup(argv[0])) == -1)
143 		goto pfree;
144 	for (argc = 1; argv[argc]; argc++) {
145 		glob_t gl;
146 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE|GLOB_LIMIT;
147 
148 		memset(&gl, 0, sizeof(gl));
149 		if (glob(argv[argc], flags, NULL, &gl)) {
150 			if (sl_add(sl, xstrdup(argv[argc])) == -1) {
151 				globfree(&gl);
152 				goto pfree;
153 			}
154 		} else {
155 			for (pop = gl.gl_pathv; *pop; pop++) {
156 				if (sl_add(sl, xstrdup(*pop)) == -1) {
157 					globfree(&gl);
158 					goto pfree;
159 				}
160 			}
161 		}
162 		globfree(&gl);
163 	}
164 	if (sl_add(sl, NULL) == -1)
165 		goto pfree;
166 
167 #ifndef NO_INTERNAL_LS
168 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
169 #endif
170 
171 	pid = isls ? fork() : vfork();
172 	switch (pid) {
173 	case -1:			/* error */
174 		(void)close(pdes[0]);
175 		(void)close(pdes[1]);
176 		goto pfree;
177 		/* NOTREACHED */
178 	case 0:				/* child */
179 		if (*ptype == 'r') {
180 			if (pdes[1] != STDOUT_FILENO) {
181 				dup2(pdes[1], STDOUT_FILENO);
182 				(void)close(pdes[1]);
183 			}
184 			if (stderrfd == -1)
185 				(void)close(STDERR_FILENO);
186 			else
187 				dup2(stderrfd, STDERR_FILENO);
188 			(void)close(pdes[0]);
189 		} else {
190 			if (pdes[0] != STDIN_FILENO) {
191 				dup2(pdes[0], STDIN_FILENO);
192 				(void)close(pdes[0]);
193 			}
194 			(void)close(pdes[1]);
195 		}
196 #ifndef NO_INTERNAL_LS
197 		if (isls) {	/* use internal ls */
198 			optreset = optind = optopt = 1;
199 			closelog();
200 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
201 		}
202 #endif
203 
204 		execv(sl->sl_str[0], sl->sl_str);
205 		_exit(1);
206 	}
207 	/* parent; assume fdopen can't fail...  */
208 	if (*ptype == 'r') {
209 		iop = fdopen(pdes[0], ptype);
210 		(void)close(pdes[1]);
211 	} else {
212 		iop = fdopen(pdes[1], ptype);
213 		(void)close(pdes[0]);
214 	}
215 	pids[fileno(iop)] = pid;
216 
217  pfree:
218 	if (sl)
219 		sl_free(sl, 1);
220 	return (iop);
221 }
222 
223 int
224 ftpd_pclose(FILE *iop)
225 {
226 	int fdes, status;
227 	pid_t pid;
228 	sigset_t nsigset, osigset;
229 
230 	/*
231 	 * pclose returns -1 if stream is not associated with a
232 	 * `popened' command, or, if already `pclosed'.
233 	 */
234 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
235 		return (-1);
236 	(void)fclose(iop);
237 	sigemptyset(&nsigset);
238 	sigaddset(&nsigset, SIGINT);
239 	sigaddset(&nsigset, SIGQUIT);
240 	sigaddset(&nsigset, SIGHUP);
241 	sigprocmask(SIG_BLOCK, &nsigset, &osigset);
242 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
243 		continue;
244 	sigprocmask(SIG_SETMASK, &osigset, NULL);
245 	pids[fdes] = 0;
246 	if (pid < 0)
247 		return (pid);
248 	if (WIFEXITED(status))
249 		return (WEXITSTATUS(status));
250 	return (1);
251 }
252