xref: /openbsd/libexec/ftpd/popen.c (revision 3bef86f7)
1 /*	$OpenBSD: popen.c,v 1.31 2023/02/17 17:59:36 miod 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 	FILE *iop;
65 	int argc = 0, pdes[2];
66 	pid_t pid;
67 	char **pop, *argv[_POSIX_ARG_MAX];
68 
69 	if (pipe(pdes) == -1)
70 		return (NULL);
71 
72 	/* break up string into pieces */
73 	argv[argc++] = "/bin/ls";
74 	argv[argc++] = "-lgA";
75 	argv[argc++] = "--";
76 
77 	/* glob that path */
78 	if (path != NULL) {
79 		glob_t gl;
80 
81 		memset(&gl, 0, sizeof(gl));
82 		if (glob(path,
83 		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
84 		    NULL, &gl)) {
85 			fatal ("Glob error.");
86 		} else if (gl.gl_pathc > 0) {
87 			for (pop = gl.gl_pathv; *pop && argc < _POSIX_ARG_MAX-1;
88 			    pop++) {
89 				argv[argc++] = strdup(*pop);
90 				if (argv[argc - 1] == NULL)
91 					fatal ("Out of memory.");
92 			}
93 		}
94 		globfree(&gl);
95 	}
96 	argv[argc] = NULL;
97 
98 	iop = NULL;
99 
100 	switch (pid = fork()) {
101 	case -1:			/* error */
102 		(void)close(pdes[0]);
103 		(void)close(pdes[1]);
104 		goto pfree;
105 		/* NOTREACHED */
106 	case 0:				/* child */
107 		if (pdes[1] != STDOUT_FILENO) {
108 			dup2(pdes[1], STDOUT_FILENO);
109 			(void)close(pdes[1]);
110 		}
111 		dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
112 		(void)close(pdes[0]);
113 		closelog();
114 
115 		extern int ls_main(int, char **);
116 
117 		/* reset getopt for ls_main */
118 		optreset = optind = 1;
119 		exit(ls_main(argc, argv));
120 	}
121 	/* parent; assume fdopen can't fail...  */
122 	iop = fdopen(pdes[0], "r");
123 	(void)close(pdes[1]);
124 	*pidptr = pid;
125 
126  pfree:
127 	for (argc = 3; argv[argc] != NULL; argc++)
128 		free(argv[argc]);
129 
130 	return (iop);
131 }
132 
133 int
134 ftpd_pclose(FILE *iop, pid_t pid)
135 {
136 	int status;
137 	pid_t rv;
138 	sigset_t sigset, osigset;
139 
140 	(void)fclose(iop);
141 	sigemptyset(&sigset);
142 	sigaddset(&sigset, SIGINT);
143 	sigaddset(&sigset, SIGQUIT);
144 	sigaddset(&sigset, SIGHUP);
145 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
146 	while ((rv = waitpid(pid, &status, 0)) == -1 && errno == EINTR)
147 		continue;
148 	sigprocmask(SIG_SETMASK, &osigset, NULL);
149 	if (rv == -1)
150 		return (-1);
151 	if (WIFEXITED(status))
152 		return (WEXITSTATUS(status));
153 	return (1);
154 }
155