sandbox-rlimit.c revision 323134 
1/* $OpenBSD: sandbox-rlimit.c,v 1.4 2016/09/12 01:22:38 deraadt Exp $ */
2/*
3 * Copyright (c) 2011 Damien Miller <djm@mindrot.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include "includes.h"
19
20#ifdef SANDBOX_RLIMIT
21
22#include <sys/types.h>
23#include <sys/time.h>
24#include <sys/resource.h>
25
26#include <errno.h>
27#include <stdarg.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <string.h>
31#include <unistd.h>
32
33#include "log.h"
34#include "ssh-sandbox.h"
35#include "xmalloc.h"
36
37/* Minimal sandbox that sets zero nfiles, nprocs and filesize rlimits */
38
39struct ssh_sandbox {
40	pid_t child_pid;
41};
42
43struct ssh_sandbox *
44ssh_sandbox_init(struct monitor *monitor)
45{
46	struct ssh_sandbox *box;
47
48	/*
49	 * Strictly, we don't need to maintain any state here but we need
50	 * to return non-NULL to satisfy the API.
51	 */
52	debug3("%s: preparing rlimit sandbox", __func__);
53	box = xcalloc(1, sizeof(*box));
54	box->child_pid = 0;
55
56	return box;
57}
58
59void
60ssh_sandbox_child(struct ssh_sandbox *box)
61{
62	struct rlimit rl_zero;
63
64	rl_zero.rlim_cur = rl_zero.rlim_max = 0;
65
66#ifndef SANDBOX_SKIP_RLIMIT_FSIZE
67	if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1)
68		fatal("%s: setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s",
69			__func__, strerror(errno));
70#endif
71#ifndef SANDBOX_SKIP_RLIMIT_NOFILE
72	if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1)
73		fatal("%s: setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s",
74			__func__, strerror(errno));
75#endif
76#ifdef HAVE_RLIMIT_NPROC
77	if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1)
78		fatal("%s: setrlimit(RLIMIT_NPROC, { 0, 0 }): %s",
79			__func__, strerror(errno));
80#endif
81}
82
83void
84ssh_sandbox_parent_finish(struct ssh_sandbox *box)
85{
86	free(box);
87	debug3("%s: finished", __func__);
88}
89
90void
91ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid)
92{
93	box->child_pid = child_pid;
94}
95
96#endif /* SANDBOX_RLIMIT */
97