xref: /netbsd-src/libexec/ftpd/popen.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd 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 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
43 #else
44 static char rcsid[] = "$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $";
45 #endif
46 #endif /* not lint */
47 
48 #include <sys/types.h>
49 #include <sys/wait.h>
50 
51 #include <errno.h>
52 #include <glob.h>
53 #include <signal.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
58 
59 #include "extern.h"
60 
61 /*
62  * Special version of popen which avoids call to shell.  This ensures noone
63  * may create a pipe to a hidden program as a side effect of a list or dir
64  * command.
65  */
66 static int *pids;
67 static int fds;
68 
69 FILE *
70 ftpd_popen(program, type)
71 	char *program, *type;
72 {
73 	char *cp;
74 	FILE *iop;
75 	int argc, gargc, pdes[2], pid;
76 	char **pop, *argv[100], *gargv[1000];
77 
78 	if (*type != 'r' && *type != 'w' || type[1])
79 		return (NULL);
80 
81 	if (!pids) {
82 		if ((fds = getdtablesize()) <= 0)
83 			return (NULL);
84 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
85 			return (NULL);
86 		memset(pids, 0, fds * sizeof(int));
87 	}
88 	if (pipe(pdes) < 0)
89 		return (NULL);
90 
91 	/* break up string into pieces */
92 	for (argc = 0, cp = program;; cp = NULL)
93 		if (!(argv[argc++] = strtok(cp, " \t\n")))
94 			break;
95 
96 	/* glob each piece */
97 	gargv[0] = argv[0];
98 	for (gargc = argc = 1; argv[argc]; argc++) {
99 		glob_t gl;
100 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
101 
102 		memset(&gl, 0, sizeof(gl));
103 		if (glob(argv[argc], flags, NULL, &gl))
104 			gargv[gargc++] = strdup(argv[argc]);
105 		else
106 			for (pop = gl.gl_pathv; *pop; pop++)
107 				gargv[gargc++] = strdup(*pop);
108 		globfree(&gl);
109 	}
110 	gargv[gargc] = NULL;
111 
112 	iop = NULL;
113 	switch(pid = vfork()) {
114 	case -1:			/* error */
115 		(void)close(pdes[0]);
116 		(void)close(pdes[1]);
117 		goto pfree;
118 		/* NOTREACHED */
119 	case 0:				/* child */
120 		if (*type == 'r') {
121 			if (pdes[1] != STDOUT_FILENO) {
122 				dup2(pdes[1], STDOUT_FILENO);
123 				(void)close(pdes[1]);
124 			}
125 			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
126 			(void)close(pdes[0]);
127 		} else {
128 			if (pdes[0] != STDIN_FILENO) {
129 				dup2(pdes[0], STDIN_FILENO);
130 				(void)close(pdes[0]);
131 			}
132 			(void)close(pdes[1]);
133 		}
134 		execv(gargv[0], gargv);
135 		_exit(1);
136 	}
137 	/* parent; assume fdopen can't fail...  */
138 	if (*type == 'r') {
139 		iop = fdopen(pdes[0], type);
140 		(void)close(pdes[1]);
141 	} else {
142 		iop = fdopen(pdes[1], type);
143 		(void)close(pdes[0]);
144 	}
145 	pids[fileno(iop)] = pid;
146 
147 pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
148 		free(gargv[argc]);
149 
150 	return (iop);
151 }
152 
153 int
154 ftpd_pclose(iop)
155 	FILE *iop;
156 {
157 	int fdes, omask, status;
158 	pid_t pid;
159 	sigset_t sigset, osigset;
160 
161 	/*
162 	 * pclose returns -1 if stream is not associated with a
163 	 * `popened' command, or, if already `pclosed'.
164 	 */
165 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
166 		return (-1);
167 	(void)fclose(iop);
168 	sigemptyset(&sigset);
169 	sigaddset(&sigset, SIGINT);
170 	sigaddset(&sigset, SIGQUIT);
171 	sigaddset(&sigset, SIGHUP);
172 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
173 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
174 		continue;
175 	sigprocmask(SIG_SETMASK, &osigset, NULL);
176 	pids[fdes] = 0;
177 	if (pid < 0)
178 		return (pid);
179 	if (WIFEXITED(status))
180 		return (WEXITSTATUS(status));
181 	return (1);
182 }
183