1/* $OpenBSD: sandbox-rlimit.c,v 1.5 2020/10/18 11:32:01 djm 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__RCSID("$NetBSD: sandbox-rlimit.c,v 1.7 2021/03/05 17:47:16 christos Exp $");
20#include <sys/types.h>
21#include <sys/time.h>
22#include <sys/resource.h>
23
24#include <errno.h>
25#include <stdarg.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30
31#include "log.h"
32#include "ssh-sandbox.h"
33#include "xmalloc.h"
34
35/* Minimal sandbox that sets zero nfiles, nprocs and filesize rlimits */
36
37struct ssh_sandbox {
38	pid_t child_pid;
39};
40
41struct ssh_sandbox *
42ssh_sandbox_init(void)
43{
44	struct ssh_sandbox *box;
45
46	/*
47	 * Strictly, we don't need to maintain any state here but we need
48	 * to return non-NULL to satisfy the API.
49	 */
50	debug3_f("preparing rlimit sandbox");
51	box = xcalloc(1, sizeof(*box));
52	box->child_pid = 0;
53
54	return box;
55}
56
57void
58ssh_sandbox_child(struct ssh_sandbox *box)
59{
60	struct rlimit rl_zero;
61
62	rl_zero.rlim_cur = rl_zero.rlim_max = 0;
63
64	if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1)
65		fatal_f("setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s",
66			strerror(errno));
67	if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1)
68		fatal_f("setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s",
69			strerror(errno));
70	if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1)
71		fatal_f("setrlimit(RLIMIT_NPROC, { 0, 0 }): %s",
72			strerror(errno));
73}
74
75void
76ssh_sandbox_parent_finish(struct ssh_sandbox *box)
77{
78	free(box);
79	debug3_f("finished");
80}
81
82void
83ssh_sandbox_parent_preauth(struct ssh_sandbox *box, pid_t child_pid)
84{
85	box->child_pid = child_pid;
86	/* Nothing to do here */
87}
88
89