popen.c revision 1.25 
1/*	$OpenBSD: popen.c,v 1.25 2015/10/04 11:58:09 tedu 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 <signal.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46#include <syslog.h>
47#include <unistd.h>
48
49#include <netinet/in.h>
50
51#include "monitor.h"
52#include "extern.h"
53
54/*
55 * Special version of popen which avoids call to shell.  This ensures noone
56 * may create a pipe to a hidden program as a side effect of a list or dir
57 * command.
58 */
59#define MAX_ARGV	100
60#define MAX_GARGV	1000
61
62FILE *
63ftpd_popen(char *program, char *type, pid_t *pidptr)
64{
65	char *cp;
66	FILE *iop;
67	int argc, gargc, pdes[2];
68	pid_t pid;
69	char **pop, *argv[MAX_ARGV], *gargv[MAX_GARGV];
70
71	if ((*type != 'r' && *type != 'w') || type[1])
72		return (NULL);
73
74	if (pipe(pdes) < 0)
75		return (NULL);
76
77	/* break up string into pieces */
78	for (argc = 0, cp = program;argc < MAX_ARGV-1; cp = NULL)
79		if (!(argv[argc++] = strtok(cp, " \t\n")))
80			break;
81	argv[MAX_ARGV-1] = NULL;
82
83	/* glob each piece */
84	gargv[0] = argv[0];
85	for (gargc = argc = 1; argv[argc]; argc++) {
86		glob_t gl;
87
88		memset(&gl, 0, sizeof(gl));
89		if (glob(argv[argc],
90		    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
91		    NULL, &gl)) {
92			if (gargc < MAX_GARGV-1) {
93				gargv[gargc++] = strdup(argv[argc]);
94				if (gargv[gargc -1] == NULL)
95					fatal ("Out of memory.");
96			}
97
98		} else if (gl.gl_pathc > 0) {
99			for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV-1; pop++) {
100				gargv[gargc++] = strdup(*pop);
101				if (gargv[gargc - 1] == NULL)
102					fatal ("Out of memory.");
103			}
104		}
105		globfree(&gl);
106	}
107	gargv[gargc] = NULL;
108
109	iop = NULL;
110
111	switch (pid = fork()) {
112	case -1:			/* error */
113		(void)close(pdes[0]);
114		(void)close(pdes[1]);
115		goto pfree;
116		/* NOTREACHED */
117	case 0:				/* child */
118		if (*type == 'r') {
119			if (pdes[1] != STDOUT_FILENO) {
120				dup2(pdes[1], STDOUT_FILENO);
121				(void)close(pdes[1]);
122			}
123			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
124			(void)close(pdes[0]);
125		} else {
126			if (pdes[0] != STDIN_FILENO) {
127				dup2(pdes[0], STDIN_FILENO);
128				(void)close(pdes[0]);
129			}
130			(void)close(pdes[1]);
131		}
132		closelog();
133
134		if (strcmp(gargv[0], "/bin/ls") == 0) {
135			extern int optreset;
136			extern int ls_main(int, char **);
137
138			/* reset getopt for ls_main */
139			optreset = optind = 1;
140			exit(ls_main(gargc, gargv));
141		}
142
143		execv(gargv[0], gargv);
144		_exit(1);
145	}
146	/* parent; assume fdopen can't fail...  */
147	if (*type == 'r') {
148		iop = fdopen(pdes[0], type);
149		(void)close(pdes[1]);
150	} else {
151		iop = fdopen(pdes[1], type);
152		(void)close(pdes[0]);
153	}
154	*pidptr = pid;
155
156pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
157		free(gargv[argc]);
158
159	return (iop);
160}
161
162int
163ftpd_pclose(FILE *iop, pid_t pid)
164{
165	int fdes, status;
166	pid_t rv;
167	sigset_t sigset, osigset;
168
169	(void)fclose(iop);
170	sigemptyset(&sigset);
171	sigaddset(&sigset, SIGINT);
172	sigaddset(&sigset, SIGQUIT);
173	sigaddset(&sigset, SIGHUP);
174	sigprocmask(SIG_BLOCK, &sigset, &osigset);
175	while ((rv = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
176		continue;
177	sigprocmask(SIG_SETMASK, &osigset, NULL);
178	if (rv < 0)
179		return (-1);
180	if (WIFEXITED(status))
181		return (WEXITSTATUS(status));
182	return (1);
183}
184