xref: /netbsd-src/libexec/ftpd/popen.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: popen.c,v 1.36 2009/03/18 02:27:41 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999-2009 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1988, 1993, 1994
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * This code is derived from software written by Ken Arnold and
37  * published in UNIX Review, Vol. 6, No. 8.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  */
64 
65 #include <sys/cdefs.h>
66 #ifndef lint
67 #if 0
68 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
69 #else
70 __RCSID("$NetBSD: popen.c,v 1.36 2009/03/18 02:27:41 lukem Exp $");
71 #endif
72 #endif /* not lint */
73 
74 #include <sys/types.h>
75 #include <sys/param.h>
76 #include <sys/wait.h>
77 
78 #include <errno.h>
79 #include <glob.h>
80 #include <signal.h>
81 #include <stdio.h>
82 #include <stdlib.h>
83 #include <string.h>
84 #include <stringlist.h>
85 #include <syslog.h>
86 #include <unistd.h>
87 
88 #ifdef KERBEROS5
89 #include <krb5/krb5.h>
90 #endif
91 
92 #include "extern.h"
93 
94 #define INCR	100
95 /*
96  * Special version of popen which avoids call to shell.  This ensures no-one
97  * may create a pipe to a hidden program as a side effect of a list or dir
98  * command.
99  * If stderrfd != -1, then send stderr of a read command there,
100  * otherwise close stderr.
101  */
102 static int *pids;
103 static int fds;
104 
105 extern int ls_main(int, char *[]);
106 
107 FILE *
108 ftpd_popen(const char *argv[], const char *ptype, int stderrfd)
109 {
110 	FILE *iop;
111 	int argc, pdes[2], pid;
112 	volatile int isls;
113 	char **pop;
114 	StringList *sl;
115 
116 	iop = NULL;
117 	isls = 0;
118 	if ((*ptype != 'r' && *ptype != 'w') || ptype[1])
119 		return (NULL);
120 
121 	if (!pids) {
122 		if ((fds = getdtablesize()) <= 0)
123 			return (NULL);
124 		if ((pids = (int *)malloc((unsigned int)(fds * sizeof(int)))) == NULL)
125 			return (NULL);
126 		memset(pids, 0, fds * sizeof(int));
127 	}
128 	if (pipe(pdes) < 0)
129 		return (NULL);
130 
131 	if ((sl = sl_init()) == NULL)
132 		goto pfree;
133 
134 					/* glob each piece */
135 	if (sl_add(sl, ftpd_strdup(argv[0])) == -1)
136 		goto pfree;
137 	for (argc = 1; argv[argc]; argc++) {
138 		glob_t gl;
139 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE|GLOB_LIMIT;
140 
141 		memset(&gl, 0, sizeof(gl));
142 		if (glob(argv[argc], flags, NULL, &gl)) {
143 			if (sl_add(sl, ftpd_strdup(argv[argc])) == -1) {
144 				globfree(&gl);
145 				goto pfree;
146 			}
147 		} else {
148 			for (pop = gl.gl_pathv; *pop; pop++) {
149 				if (sl_add(sl, ftpd_strdup(*pop)) == -1) {
150 					globfree(&gl);
151 					goto pfree;
152 				}
153 			}
154 		}
155 		globfree(&gl);
156 	}
157 	if (sl_add(sl, NULL) == -1)
158 		goto pfree;
159 
160 #ifndef NO_INTERNAL_LS
161 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
162 #endif
163 
164 	pid = isls ? fork() : vfork();
165 	switch (pid) {
166 	case -1:			/* error */
167 		(void)close(pdes[0]);
168 		(void)close(pdes[1]);
169 		goto pfree;
170 		/* NOTREACHED */
171 	case 0:				/* child */
172 		if (*ptype == 'r') {
173 			if (pdes[1] != STDOUT_FILENO) {
174 				dup2(pdes[1], STDOUT_FILENO);
175 				(void)close(pdes[1]);
176 			}
177 			if (stderrfd == -1)
178 				(void)close(STDERR_FILENO);
179 			else
180 				dup2(stderrfd, STDERR_FILENO);
181 			(void)close(pdes[0]);
182 		} else {
183 			if (pdes[0] != STDIN_FILENO) {
184 				dup2(pdes[0], STDIN_FILENO);
185 				(void)close(pdes[0]);
186 			}
187 			(void)close(pdes[1]);
188 		}
189 #ifndef NO_INTERNAL_LS
190 		if (isls) {	/* use internal ls */
191 			optreset = optind = optopt = 1;
192 			closelog();
193 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
194 		}
195 #endif
196 
197 		execv(sl->sl_str[0], sl->sl_str);
198 		_exit(1);
199 	}
200 	/* parent; assume fdopen can't fail...  */
201 	if (*ptype == 'r') {
202 		iop = fdopen(pdes[0], ptype);
203 		(void)close(pdes[1]);
204 	} else {
205 		iop = fdopen(pdes[1], ptype);
206 		(void)close(pdes[0]);
207 	}
208 	pids[fileno(iop)] = pid;
209 
210  pfree:
211 	if (sl)
212 		sl_free(sl, 1);
213 	return (iop);
214 }
215 
216 int
217 ftpd_pclose(FILE *iop)
218 {
219 	int fdes, status;
220 	pid_t pid;
221 	sigset_t nsigset, osigset;
222 
223 	/*
224 	 * pclose returns -1 if stream is not associated with a
225 	 * `popened' command, or, if already `pclosed'.
226 	 */
227 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
228 		return (-1);
229 	(void)fclose(iop);
230 	sigemptyset(&nsigset);
231 	sigaddset(&nsigset, SIGINT);
232 	sigaddset(&nsigset, SIGQUIT);
233 	sigaddset(&nsigset, SIGHUP);
234 	sigprocmask(SIG_BLOCK, &nsigset, &osigset);
235 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
236 		continue;
237 	sigprocmask(SIG_SETMASK, &osigset, NULL);
238 	pids[fdes] = 0;
239 	if (pid < 0)
240 		return (pid);
241 	if (WIFEXITED(status))
242 		return (WEXITSTATUS(status));
243 	return (1);
244 }
245