xref: /netbsd-src/libexec/ftpd/popen.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: popen.c,v 1.8 1997/06/18 19:05:52 christos 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 #include <sys/cdefs.h>
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
44 #else
45 __RCSID("$NetBSD: popen.c,v 1.8 1997/06/18 19:05:52 christos Exp $");
46 #endif
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 #include <sys/wait.h>
51 
52 #include <errno.h>
53 #include <glob.h>
54 #include <signal.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 
60 #include "extern.h"
61 
62 #define INCR	100
63 /*
64  * Special version of popen which avoids call to shell.  This ensures noone
65  * may create a pipe to a hidden program as a side effect of a list or dir
66  * command.
67  */
68 static int *pids;
69 static int fds;
70 
71 FILE *
72 ftpd_popen(program, type, nostderr)
73 	char *program, *type;
74 	int nostderr;
75 {
76 	char *cp;
77 	FILE *iop = NULL;
78 	int argc, gargc, pdes[2], pid;
79 	char **pop, **np;
80 	char **argv = NULL, **gargv = NULL;
81 	size_t nargc = 100, ngargc = 100;
82 #ifdef __GNUC__
83 	(void) &iop;
84 	(void) &gargc;
85 	(void) &gargv;
86 	(void) &argv;
87 #endif
88 
89 	if ((*type != 'r' && *type != 'w') || type[1])
90 		return (NULL);
91 
92 	if (!pids) {
93 		if ((fds = getdtablesize()) <= 0)
94 			return (NULL);
95 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
96 			return (NULL);
97 		memset(pids, 0, fds * sizeof(int));
98 	}
99 	if (pipe(pdes) < 0)
100 		return (NULL);
101 
102 	if ((argv = malloc(nargc * sizeof(char *))) == NULL)
103 		return NULL;
104 
105 #define CHECKMORE(c, v, n) \
106 	if (c >= n + 2) { \
107 		n += INCR; \
108 		if ((np = realloc(v, n * sizeof(char *))) == NULL) \
109 			goto pfree; \
110 		else \
111 			v = np; \
112 	}
113 
114 	/* break up string into pieces */
115 	for (argc = 0, cp = program;; cp = NULL) {
116 		CHECKMORE(argc, argv, nargc)
117 		if (!(argv[argc++] = strtok(cp, " \t\n")))
118 			break;
119 	}
120 
121 	if ((gargv = malloc(ngargc * sizeof(char *))) == NULL)
122 		goto pfree;
123 
124 	/* glob each piece */
125 	gargv[0] = argv[0];
126 	for (gargc = argc = 1; argv[argc]; argc++) {
127 		glob_t gl;
128 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
129 
130 		memset(&gl, 0, sizeof(gl));
131 		if (glob(argv[argc], flags, NULL, &gl)) {
132 			CHECKMORE(gargc, gargv, ngargc)
133 			if ((gargv[gargc++] = strdup(argv[argc])) == NULL)
134 				goto pfree;
135 		}
136 		else
137 			for (pop = gl.gl_pathv; *pop; pop++) {
138 				CHECKMORE(gargc, gargv, ngargc)
139 				if ((gargv[gargc++] = strdup(*pop)) == NULL)
140 					goto pfree;
141 			}
142 		globfree(&gl);
143 	}
144 	gargv[gargc] = NULL;
145 
146 	switch(pid = vfork()) {
147 	case -1:			/* error */
148 		(void)close(pdes[0]);
149 		(void)close(pdes[1]);
150 		goto pfree;
151 		/* NOTREACHED */
152 	case 0:				/* child */
153 		if (*type == 'r') {
154 			if (pdes[1] != STDOUT_FILENO) {
155 				dup2(pdes[1], STDOUT_FILENO);
156 				(void)close(pdes[1]);
157 			}
158 			if (nostderr)
159 				(void)close(STDERR_FILENO);
160 			else		/* stderr too! */
161 				dup2(STDOUT_FILENO, STDERR_FILENO);
162 			(void)close(pdes[0]);
163 		} else {
164 			if (pdes[0] != STDIN_FILENO) {
165 				dup2(pdes[0], STDIN_FILENO);
166 				(void)close(pdes[0]);
167 			}
168 			(void)close(pdes[1]);
169 		}
170 		execv(gargv[0], gargv);
171 		_exit(1);
172 	}
173 	/* parent; assume fdopen can't fail...  */
174 	if (*type == 'r') {
175 		iop = fdopen(pdes[0], type);
176 		(void)close(pdes[1]);
177 	} else {
178 		iop = fdopen(pdes[1], type);
179 		(void)close(pdes[0]);
180 	}
181 	pids[fileno(iop)] = pid;
182 
183 pfree:	if (gargv) {
184 		for (argc = 1; argc < gargc; argc++)
185 			free(gargv[argc]);
186 		free(gargv);
187 	}
188 	if (argv)
189 		free(argv);
190 
191 	return (iop);
192 }
193 
194 int
195 ftpd_pclose(iop)
196 	FILE *iop;
197 {
198 	int fdes, status;
199 	pid_t pid;
200 	sigset_t sigset, osigset;
201 
202 	/*
203 	 * pclose returns -1 if stream is not associated with a
204 	 * `popened' command, or, if already `pclosed'.
205 	 */
206 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
207 		return (-1);
208 	(void)fclose(iop);
209 	sigemptyset(&sigset);
210 	sigaddset(&sigset, SIGINT);
211 	sigaddset(&sigset, SIGQUIT);
212 	sigaddset(&sigset, SIGHUP);
213 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
214 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
215 		continue;
216 	sigprocmask(SIG_SETMASK, &osigset, NULL);
217 	pids[fdes] = 0;
218 	if (pid < 0)
219 		return (pid);
220 	if (WIFEXITED(status))
221 		return (WEXITSTATUS(status));
222 	return (1);
223 }
224