xref: /freebsd/libexec/ftpd/popen.c (revision 8e537d168674d6b65869f73c20813001af875738)
1 /*
2  * Copyright (c) 1988, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software written by Ken Arnold and
6  * published in UNIX Review, Vol. 6, No. 8.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	$Id$
37  */
38 
39 #if 0
40 #ifndef lint
41 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
42 #endif /* not lint */
43 #endif
44 
45 #include <sys/types.h>
46 #include <sys/wait.h>
47 
48 #include <errno.h>
49 #include <glob.h>
50 #include <signal.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 #include "extern.h"
57 
58 /*
59  * Special version of popen which avoids call to shell.  This ensures noone
60  * may create a pipe to a hidden program as a side effect of a list or dir
61  * command.
62  */
63 static int *pids;
64 static int fds;
65 
66 FILE *
67 ftpd_popen(program, type)
68 	char *program, *type;
69 {
70 	char *cp;
71 	FILE *iop;
72 	int argc, gargc, pdes[2], pid;
73 	char **pop, *argv[100], *gargv[1000];
74 
75 	if (((*type != 'r') && (*type != 'w')) || type[1])
76 		return (NULL);
77 
78 	if (!pids) {
79 		if ((fds = getdtablesize()) <= 0)
80 			return (NULL);
81 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
82 			return (NULL);
83 		memset(pids, 0, fds * sizeof(int));
84 	}
85 	if (pipe(pdes) < 0)
86 		return (NULL);
87 
88 	/* break up string into pieces */
89 	for (argc = 0, cp = program;; cp = NULL)
90 		if (!(argv[argc++] = strtok(cp, " \t\n")))
91 			break;
92 
93 	/* glob each piece */
94 	gargv[0] = argv[0];
95 	for (gargc = argc = 1; argv[argc]; argc++) {
96 		glob_t gl;
97 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
98 
99 		memset(&gl, 0, sizeof(gl));
100 		if (glob(argv[argc], flags, NULL, &gl))
101 			gargv[gargc++] = strdup(argv[argc]);
102 		else
103 			for (pop = gl.gl_pathv; *pop; pop++)
104 				gargv[gargc++] = strdup(*pop);
105 		globfree(&gl);
106 	}
107 	gargv[gargc] = NULL;
108 
109 	iop = NULL;
110 	switch(pid = vfork()) {
111 	case -1:			/* error */
112 		(void)close(pdes[0]);
113 		(void)close(pdes[1]);
114 		goto pfree;
115 		/* NOTREACHED */
116 	case 0:				/* child */
117 		if (*type == 'r') {
118 			if (pdes[1] != STDOUT_FILENO) {
119 				dup2(pdes[1], STDOUT_FILENO);
120 				(void)close(pdes[1]);
121 			}
122 			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
123 			(void)close(pdes[0]);
124 		} else {
125 			if (pdes[0] != STDIN_FILENO) {
126 				dup2(pdes[0], STDIN_FILENO);
127 				(void)close(pdes[0]);
128 			}
129 			(void)close(pdes[1]);
130 		}
131 		execv(gargv[0], gargv);
132 		_exit(1);
133 	}
134 	/* parent; assume fdopen can't fail...  */
135 	if (*type == 'r') {
136 		iop = fdopen(pdes[0], type);
137 		(void)close(pdes[1]);
138 	} else {
139 		iop = fdopen(pdes[1], type);
140 		(void)close(pdes[0]);
141 	}
142 	pids[fileno(iop)] = pid;
143 
144 pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
145 		free(gargv[argc]);
146 
147 	return (iop);
148 }
149 
150 int
151 ftpd_pclose(iop)
152 	FILE *iop;
153 {
154 	int fdes, omask, status;
155 	pid_t pid;
156 
157 	/*
158 	 * pclose returns -1 if stream is not associated with a
159 	 * `popened' command, or, if already `pclosed'.
160 	 */
161 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
162 		return (-1);
163 	(void)fclose(iop);
164 	omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
165 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
166 		continue;
167 	(void)sigsetmask(omask);
168 	pids[fdes] = 0;
169 	if (pid < 0)
170 		return (pid);
171 	if (WIFEXITED(status))
172 		return (WEXITSTATUS(status));
173 	return (1);
174 }
175