xref: /freebsd/crypto/openssh/platform-tracing.c (revision 7a8d62cd046942ab34fcf282ecbbb0747a08a4ee)
1 /*
2  * Copyright (c) 2016 Darren Tucker.  All rights reserved.
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "includes.h"
18 
19 #include <sys/types.h>
20 #ifdef HAVE_SYS_PROCCTL_H
21 #include <sys/procctl.h>
22 #endif
23 #if defined(HAVE_SYS_PRCTL_H)
24 #include <sys/prctl.h>	/* For prctl() and PR_SET_DUMPABLE */
25 #endif
26 #ifdef HAVE_SYS_PTRACE_H
27 #include <sys/ptrace.h>
28 #endif
29 #ifdef HAVE_PRIV_H
30 #include <priv.h> /* For setpflags() and __PROC_PROTECT  */
31 #endif
32 #include <stdarg.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 #include "log.h"
38 
39 void
40 platform_disable_tracing(int strict)
41 {
42 #if defined(HAVE_PROCCTL) && defined(PROC_TRACE_CTL)
43 	/* On FreeBSD, we should make this process untraceable */
44 	int disable_trace = PROC_TRACE_CTL_DISABLE;
45 
46 	/*
47 	 * On FreeBSD, we should make this process untraceable.
48 	 * pid=0 means "this process" but some older kernels do not
49 	 * understand that so retry with our own pid before failing.
50 	 */
51 	if (procctl(P_PID, 0, PROC_TRACE_CTL, &disable_trace) == 0)
52 		return;
53 	if (procctl(P_PID, getpid(), PROC_TRACE_CTL, &disable_trace) == 0)
54 		return;
55 	if (strict)
56 		fatal("unable to make the process untraceable: %s",
57 		    strerror(errno));
58 #endif
59 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
60 	/* Disable ptrace on Linux without sgid bit */
61 	if (prctl(PR_SET_DUMPABLE, 0) != 0 && strict)
62 		fatal("unable to make the process undumpable: %s",
63 		    strerror(errno));
64 #endif
65 #if defined(HAVE_SETPFLAGS) && defined(__PROC_PROTECT)
66 	/* On Solaris, we should make this process untraceable */
67 	if (setpflags(__PROC_PROTECT, 1) != 0 && strict)
68 		fatal("unable to make the process untraceable: %s",
69 		    strerror(errno));
70 #endif
71 #ifdef PT_DENY_ATTACH
72 	/* Mac OS X */
73 	if (ptrace(PT_DENY_ATTACH, 0, 0, 0) == -1 && strict)
74 		fatal("unable to set PT_DENY_ATTACH: %s", strerror(errno));
75 #endif
76 }
77