xref: /openbsd-src/libexec/ftpd/popen.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: popen.c,v 1.13 2001/03/18 17:20:13 deraadt Exp $	*/
2 /*	$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software written by Ken Arnold and
9  * published in UNIX Review, Vol. 6, No. 8.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
44 #else
45 static char rcsid[] = "$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd 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 <syslog.h>
59 #include <unistd.h>
60 
61 #include <netinet/in.h>
62 #include "extern.h"
63 
64 /*
65  * Special version of popen which avoids call to shell.  This ensures noone
66  * may create a pipe to a hidden program as a side effect of a list or dir
67  * command.
68  */
69 static int *pids;
70 static int fds;
71 
72 #define MAX_ARGV	100
73 #define MAX_GARGV	1000
74 
75 FILE *
76 ftpd_popen(program, type)
77 	char *program, *type;
78 {
79 	char *cp;
80 	FILE *iop;
81 	int argc, gargc, pdes[2], pid;
82 	char **pop, *argv[MAX_ARGV], *gargv[MAX_GARGV];
83 
84 	if ((*type != 'r' && *type != 'w') || type[1])
85 		return (NULL);
86 
87 	if (!pids) {
88 		if ((fds = getdtablesize()) <= 0)
89 			return (NULL);
90 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
91 			return (NULL);
92 		memset(pids, 0, fds * sizeof(int));
93 	}
94 	if (pipe(pdes) < 0)
95 		return (NULL);
96 
97 	/* break up string into pieces */
98 	for (argc = 0, cp = program;argc < MAX_ARGV-1; cp = NULL)
99 		if (!(argv[argc++] = strtok(cp, " \t\n")))
100 			break;
101 	argv[MAX_ARGV-1] = NULL;
102 
103 	/* glob each piece */
104 	gargv[0] = argv[0];
105 	for (gargc = argc = 1; argv[argc]; argc++) {
106 		glob_t gl;
107 
108 		memset(&gl, 0, sizeof(gl));
109 		if (glob(argv[argc],
110 		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
111 		    NULL, &gl)) {
112 			if (gargc < MAX_GARGV-1) {
113 				gargv[gargc++] = strdup(argv[argc]);
114 				if (gargv[gargc -1] == NULL)
115 					fatal ("Out of memory");
116 			}
117 
118 		} else
119 			for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV-1; pop++) {
120 				gargv[gargc++] = strdup(*pop);
121 				if (gargv[gargc - 1] == NULL)
122 					fatal ("Out of memory");
123 			}
124 		globfree(&gl);
125 	}
126 	gargv[gargc] = NULL;
127 
128 	iop = NULL;
129 
130 	switch(pid = fork()) {
131 	case -1:			/* error */
132 		(void)close(pdes[0]);
133 		(void)close(pdes[1]);
134 		goto pfree;
135 		/* NOTREACHED */
136 	case 0:				/* child */
137 		if (*type == 'r') {
138 			if (pdes[1] != STDOUT_FILENO) {
139 				dup2(pdes[1], STDOUT_FILENO);
140 				(void)close(pdes[1]);
141 			}
142 			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
143 			(void)close(pdes[0]);
144 		} else {
145 			if (pdes[0] != STDIN_FILENO) {
146 				dup2(pdes[0], STDIN_FILENO);
147 				(void)close(pdes[0]);
148 			}
149 			(void)close(pdes[1]);
150 		}
151 		closelog();
152 
153 		if (strcmp(gargv[0], "/bin/ls") == 0) {
154 			extern int optreset;
155 			extern int ls_main(int, char **);
156 
157 			/* reset getopt for ls_main */
158 			optreset = optind = 1;
159 			exit(ls_main(gargc, gargv));
160 		}
161 
162 		execv(gargv[0], gargv);
163 		_exit(1);
164 	}
165 	/* parent; assume fdopen can't fail...  */
166 	if (*type == 'r') {
167 		iop = fdopen(pdes[0], type);
168 		(void)close(pdes[1]);
169 	} else {
170 		iop = fdopen(pdes[1], type);
171 		(void)close(pdes[0]);
172 	}
173 	pids[fileno(iop)] = pid;
174 
175 pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
176 		free(gargv[argc]);
177 
178 	return (iop);
179 }
180 
181 int
182 ftpd_pclose(iop)
183 	FILE *iop;
184 {
185 	int fdes, status;
186 	pid_t pid;
187 	sigset_t sigset, osigset;
188 
189 	/*
190 	 * pclose returns -1 if stream is not associated with a
191 	 * `popened' command, or, if already `pclosed'.
192 	 */
193 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
194 		return (-1);
195 	(void)fclose(iop);
196 	sigemptyset(&sigset);
197 	sigaddset(&sigset, SIGINT);
198 	sigaddset(&sigset, SIGQUIT);
199 	sigaddset(&sigset, SIGHUP);
200 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
201 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
202 		continue;
203 	sigprocmask(SIG_SETMASK, &osigset, NULL);
204 	pids[fdes] = 0;
205 	if (pid < 0)
206 		return (pid);
207 	if (WIFEXITED(status))
208 		return (WEXITSTATUS(status));
209 	return (1);
210 }
211