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
61FILE *
62ftpd_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
133int
134ftpd_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