xref: /dragonfly/libexec/ftpd/popen.c (revision a32bc35d)
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  * @(#)popen.c	8.3 (Berkeley) 4/6/94
37  * $FreeBSD: src/libexec/ftpd/popen.c,v 1.26 2004/11/18 13:46:29 yar Exp $
38  */
39 
40 #include <sys/types.h>
41 #include <sys/wait.h>
42 #include <netinet/in.h>
43 
44 #include <errno.h>
45 #include <glob.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 
52 #include "extern.h"
53 #include "pathnames.h"
54 #include <syslog.h>
55 #include <time.h>
56 
57 #define	MAXUSRARGS	100
58 #define	MAXGLOBARGS	1000
59 
60 /*
61  * Special version of popen which avoids call to shell.  This ensures noone
62  * may create a pipe to a hidden program as a side effect of a list or dir
63  * command.
64  */
65 static int *pids;
66 static int fds;
67 
68 FILE *
69 ftpd_popen(char *program, char *type)
70 {
71 	char *cp;
72 	FILE *iop;
73 	int argc, gargc, pdes[2], pid;
74 	char **pop, *argv[MAXUSRARGS], *gargv[MAXGLOBARGS];
75 
76 	if (((*type != 'r') && (*type != 'w')) || type[1])
77 		return (NULL);
78 
79 	if (!pids) {
80 		if ((fds = getdtablesize()) <= 0)
81 			return (NULL);
82 		if ((pids = malloc(fds * sizeof(int))) == NULL)
83 			return (NULL);
84 		memset(pids, 0, fds * sizeof(int));
85 	}
86 	if (pipe(pdes) < 0)
87 		return (NULL);
88 
89 	/* break up string into pieces */
90 	for (argc = 0, cp = program; argc < MAXUSRARGS; cp = NULL) {
91 		if (!(argv[argc++] = strtok(cp, " \t\n")))
92 			break;
93 	}
94 	argv[argc - 1] = NULL;
95 
96 	/* glob each piece */
97 	gargv[0] = argv[0];
98 	for (gargc = argc = 1; argv[argc] && gargc < (MAXGLOBARGS-1); argc++) {
99 		glob_t gl;
100 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
101 
102 		memset(&gl, 0, sizeof(gl));
103 		gl.gl_matchc = MAXGLOBARGS;
104 		/*flags |= GLOB_LIMIT;*/
105 		if (glob(argv[argc], flags, NULL, &gl))
106 			gargv[gargc++] = strdup(argv[argc]);
107 		else
108 			for (pop = gl.gl_pathv; *pop && gargc < (MAXGLOBARGS-1);
109 			     pop++)
110 				gargv[gargc++] = strdup(*pop);
111 		globfree(&gl);
112 	}
113 	gargv[gargc] = NULL;
114 
115 	iop = NULL;
116 	fflush(NULL);
117 	pid = (strcmp(gargv[0], _PATH_LS) == 0) ? fork() : vfork();
118 	switch(pid) {
119 	case -1:			/* error */
120 		close(pdes[0]);
121 		close(pdes[1]);
122 		goto pfree;
123 		/* NOTREACHED */
124 	case 0:				/* child */
125 		if (*type == 'r') {
126 			if (pdes[1] != STDOUT_FILENO) {
127 				dup2(pdes[1], STDOUT_FILENO);
128 				close(pdes[1]);
129 			}
130 			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
131 			close(pdes[0]);
132 		} else {
133 			if (pdes[0] != STDIN_FILENO) {
134 				dup2(pdes[0], STDIN_FILENO);
135 				close(pdes[0]);
136 			}
137 			close(pdes[1]);
138 		}
139 		if (strcmp(gargv[0], _PATH_LS) == 0) {
140 			/* Reset getopt for ls_main() */
141 			optreset = optind = optopt = 1;
142 			/* Close syslogging to remove pwd.db missing msgs */
143 			closelog();
144 			/* Trigger to sense new /etc/localtime after chroot */
145 			if (getenv("TZ") == NULL) {
146 				if (setenv("TZ", "", 0) == -1)
147 					syslog(LOG_ERR, "setenv: cannot set TZ: %m");
148 				tzset();
149 				unsetenv("TZ");
150 				tzset();
151 			}
152 			exit(ls_main(gargc, gargv));
153 		}
154 		execv(gargv[0], gargv);
155 		_exit(1);
156 	}
157 	/* parent; assume fdopen can't fail...  */
158 	if (*type == 'r') {
159 		iop = fdopen(pdes[0], type);
160 		close(pdes[1]);
161 	} else {
162 		iop = fdopen(pdes[1], type);
163 		close(pdes[0]);
164 	}
165 	pids[fileno(iop)] = pid;
166 
167 pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
168 		free(gargv[argc]);
169 
170 	return (iop);
171 }
172 
173 int
174 ftpd_pclose(FILE *iop)
175 {
176 	int fdes, omask, status;
177 	pid_t pid;
178 
179 	/*
180 	 * pclose returns -1 if stream is not associated with a
181 	 * `popened' command, or, if already `pclosed'.
182 	 */
183 	if (pids == NULL || pids[fdes = fileno(iop)] == 0)
184 		return (-1);
185 	fclose(iop);
186 	omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
187 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
188 		continue;
189 	sigsetmask(omask);
190 	pids[fdes] = 0;
191 	if (pid < 0)
192 		return (pid);
193 	if (WIFEXITED(status))
194 		return (WEXITSTATUS(status));
195 	return (1);
196 }
197