xref: /openbsd/libexec/ftpd/popen.c (revision 097a140d)
1 /*	$OpenBSD: popen.c,v 1.30 2020/12/27 15:11:04 florian 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. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  */
36 
37 #include <sys/types.h>
38 #include <sys/wait.h>
39 
40 #include <errno.h>
41 #include <glob.h>
42 #include <limits.h>
43 #include <signal.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <syslog.h>
48 #include <unistd.h>
49 
50 #include <netinet/in.h>
51 
52 #include "monitor.h"
53 #include "extern.h"
54 
55 /*
56  * Special version of popen which avoids call to shell.  This ensures no one
57  * may create a pipe to a hidden program as a side effect of a list or dir
58  * command.
59  */
60 
61 FILE *
62 ftpd_ls(const char *path, pid_t *pidptr)
63 {
64 	char *cp;
65 	FILE *iop;
66 	int argc = 0, pdes[2];
67 	pid_t pid;
68 	char **pop, *argv[_POSIX_ARG_MAX];
69 
70 	if (pipe(pdes) == -1)
71 		return (NULL);
72 
73 	/* break up string into pieces */
74 	argv[argc++] = "/bin/ls";
75 	argv[argc++] = "-lgA";
76 	argv[argc++] = "--";
77 
78 	/* glob that path */
79 	if (path != NULL) {
80 		glob_t gl;
81 
82 		memset(&gl, 0, sizeof(gl));
83 		if (glob(path,
84 		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
85 		    NULL, &gl)) {
86 			fatal ("Glob error.");
87 		} else if (gl.gl_pathc > 0) {
88 			for (pop = gl.gl_pathv; *pop && argc < _POSIX_ARG_MAX-1;
89 			    pop++) {
90 				argv[argc++] = strdup(*pop);
91 				if (argv[argc - 1] == NULL)
92 					fatal ("Out of memory.");
93 			}
94 		}
95 		globfree(&gl);
96 	}
97 	argv[argc] = NULL;
98 
99 	iop = NULL;
100 
101 	switch (pid = fork()) {
102 	case -1:			/* error */
103 		(void)close(pdes[0]);
104 		(void)close(pdes[1]);
105 		goto pfree;
106 		/* NOTREACHED */
107 	case 0:				/* child */
108 		if (pdes[1] != STDOUT_FILENO) {
109 			dup2(pdes[1], STDOUT_FILENO);
110 			(void)close(pdes[1]);
111 		}
112 		dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
113 		(void)close(pdes[0]);
114 		closelog();
115 
116 		extern int ls_main(int, char **);
117 
118 		/* reset getopt for ls_main */
119 		optreset = optind = 1;
120 		exit(ls_main(argc, argv));
121 	}
122 	/* parent; assume fdopen can't fail...  */
123 	iop = fdopen(pdes[0], "r");
124 	(void)close(pdes[1]);
125 	*pidptr = pid;
126 
127  pfree:
128 	for (argc = 3; argv[argc] != NULL; argc++)
129 		free(argv[argc]);
130 
131 	return (iop);
132 }
133 
134 int
135 ftpd_pclose(FILE *iop, pid_t pid)
136 {
137 	int status;
138 	pid_t rv;
139 	sigset_t sigset, osigset;
140 
141 	(void)fclose(iop);
142 	sigemptyset(&sigset);
143 	sigaddset(&sigset, SIGINT);
144 	sigaddset(&sigset, SIGQUIT);
145 	sigaddset(&sigset, SIGHUP);
146 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
147 	while ((rv = waitpid(pid, &status, 0)) == -1 && errno == EINTR)
148 		continue;
149 	sigprocmask(SIG_SETMASK, &osigset, NULL);
150 	if (rv == -1)
151 		return (-1);
152 	if (WIFEXITED(status))
153 		return (WEXITSTATUS(status));
154 	return (1);
155 }
156