1/*
2 * Copyright (c) 2006 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 <stdarg.h>
20#include <unistd.h>
21
22#include "log.h"
23#include "misc.h"
24#include "servconf.h"
25#include "sshkey.h"
26#include "hostfile.h"
27#include "auth.h"
28#include "auth-pam.h"
29#include "platform.h"
30
31#include "openbsd-compat/openbsd-compat.h"
32
33extern int use_privsep;
34extern ServerOptions options;
35
36void
37platform_pre_listen(void)
38{
39#ifdef LINUX_OOM_ADJUST
40	/* Adjust out-of-memory killer so listening process is not killed */
41	oom_adjust_setup();
42#endif
43}
44
45void
46platform_pre_fork(void)
47{
48#ifdef USE_SOLARIS_PROCESS_CONTRACTS
49	solaris_contract_pre_fork();
50#endif
51}
52
53void
54platform_pre_restart(void)
55{
56#ifdef LINUX_OOM_ADJUST
57	oom_adjust_restore();
58#endif
59}
60
61void
62platform_post_fork_parent(pid_t child_pid)
63{
64#ifdef USE_SOLARIS_PROCESS_CONTRACTS
65	solaris_contract_post_fork_parent(child_pid);
66#endif
67}
68
69void
70platform_post_fork_child(void)
71{
72#ifdef USE_SOLARIS_PROCESS_CONTRACTS
73	solaris_contract_post_fork_child();
74#endif
75#ifdef LINUX_OOM_ADJUST
76	oom_adjust_restore();
77#endif
78}
79
80/* return 1 if we are running with privilege to swap UIDs, 0 otherwise */
81int
82platform_privileged_uidswap(void)
83{
84#ifdef HAVE_CYGWIN
85	/* uid 0 is not special on Cygwin so always try */
86	return 1;
87#else
88	return (getuid() == 0 || geteuid() == 0);
89#endif
90}
91
92/*
93 * This gets called before switching UIDs, and is called even when sshd is
94 * not running as root.
95 */
96void
97platform_setusercontext(struct passwd *pw)
98{
99#ifdef WITH_SELINUX
100	/* Cache selinux status for later use */
101	(void)ssh_selinux_enabled();
102#endif
103
104#ifdef USE_SOLARIS_PROJECTS
105	/*
106	 * If solaris projects were detected, set the default now, unless
107	 * we are using PAM in which case it is the responsibility of the
108	 * PAM stack.
109	 */
110	if (!options.use_pam && (getuid() == 0 || geteuid() == 0))
111		solaris_set_default_project(pw);
112#endif
113
114#if defined(HAVE_LOGIN_CAP) && defined (__bsdi__)
115	if (getuid() == 0 || geteuid() == 0)
116		setpgid(0, 0);
117# endif
118
119#if defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
120	/*
121	 * If we have both LOGIN_CAP and PAM, we want to establish creds
122	 * before calling setusercontext (in session.c:do_setusercontext).
123	 */
124	if (getuid() == 0 || geteuid() == 0) {
125		if (options.use_pam) {
126			do_pam_setcred(use_privsep);
127		}
128	}
129# endif /* USE_PAM */
130
131#if !defined(HAVE_LOGIN_CAP) && defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
132	if (getuid() == 0 || geteuid() == 0) {
133		/* Sets login uid for accounting */
134		if (getluid() == -1 && setluid(pw->pw_uid) == -1)
135			error("setluid: %s", strerror(errno));
136	}
137#endif
138}
139
140/*
141 * This gets called after we've established the user's groups, and is only
142 * called if sshd is running as root.
143 */
144void
145platform_setusercontext_post_groups(struct passwd *pw)
146{
147#if !defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
148	/*
149	 * PAM credentials may take the form of supplementary groups.
150	 * These will have been wiped by the above initgroups() call.
151	 * Reestablish them here.
152	 */
153	if (options.use_pam) {
154		do_pam_setcred(use_privsep);
155	}
156#endif /* USE_PAM */
157
158#if !defined(HAVE_LOGIN_CAP) && (defined(WITH_IRIX_PROJECT) || \
159    defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY))
160	irix_setusercontext(pw);
161#endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
162
163#ifdef _AIX
164	aix_usrinfo(pw);
165#endif /* _AIX */
166
167#ifdef HAVE_SETPCRED
168	/*
169	 * If we have a chroot directory, we set all creds except real
170	 * uid which we will need for chroot.  If we don't have a
171	 * chroot directory, we don't override anything.
172	 */
173	{
174		char **creds = NULL, *chroot_creds[] =
175		    { "REAL_USER=root", NULL };
176
177		if (options.chroot_directory != NULL &&
178		    strcasecmp(options.chroot_directory, "none") != 0)
179			creds = chroot_creds;
180
181		if (setpcred(pw->pw_name, creds) == -1)
182			fatal("Failed to set process credentials");
183	}
184#endif /* HAVE_SETPCRED */
185#ifdef WITH_SELINUX
186	ssh_selinux_setup_exec_context(pw->pw_name);
187#endif
188}
189
190char *
191platform_krb5_get_principal_name(const char *pw_name)
192{
193#ifdef USE_AIX_KRB_NAME
194	return aix_krb5_get_principal_name(pw_name);
195#else
196	return NULL;
197#endif
198}
199