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
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
39 struct ssh_sandbox {
40 int junk;
41 };
42
43 struct ssh_sandbox *
ssh_sandbox_init(struct monitor * monitor)44 ssh_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_f("preparing rlimit sandbox");
53 box = xcalloc(1, sizeof(*box));
54 return box;
55 }
56
57 void
ssh_sandbox_child(struct ssh_sandbox * box)58 ssh_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 #ifndef SANDBOX_SKIP_RLIMIT_FSIZE
65 if (setrlimit(RLIMIT_FSIZE, &rl_zero) == -1)
66 fatal_f("setrlimit(RLIMIT_FSIZE, { 0, 0 }): %s",
67 strerror(errno));
68 #endif
69 #ifndef SANDBOX_SKIP_RLIMIT_NOFILE
70 if (setrlimit(RLIMIT_NOFILE, &rl_zero) == -1)
71 fatal_f("setrlimit(RLIMIT_NOFILE, { 0, 0 }): %s",
72 strerror(errno));
73 #endif
74 #ifdef HAVE_RLIMIT_NPROC
75 if (setrlimit(RLIMIT_NPROC, &rl_zero) == -1)
76 fatal_f("setrlimit(RLIMIT_NPROC, { 0, 0 }): %s",
77 strerror(errno));
78 #endif
79 }
80
81 #endif /* SANDBOX_RLIMIT */
82