1 /* $Id: platform.c,v 1.22 2014/07/18 04:11:26 djm Exp $ */
2
3 /*
4 * Copyright (c) 2006 Darren Tucker. All rights reserved.
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include "includes.h"
20
21 #include <stdarg.h>
22 #include <unistd.h>
23
24 #include "log.h"
25 #include "buffer.h"
26 #include "misc.h"
27 #include "servconf.h"
28 #include "key.h"
29 #include "hostfile.h"
30 #include "auth.h"
31 #include "auth-pam.h"
32 #include "platform.h"
33
34 #include "openbsd-compat/openbsd-compat.h"
35
36 extern int use_privsep;
37 extern ServerOptions options;
38
39 void
platform_pre_listen(void)40 platform_pre_listen(void)
41 {
42 #ifdef LINUX_OOM_ADJUST
43 /* Adjust out-of-memory killer so listening process is not killed */
44 oom_adjust_setup();
45 #endif
46 }
47
48 void
platform_pre_fork(void)49 platform_pre_fork(void)
50 {
51 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
52 solaris_contract_pre_fork();
53 #endif
54 }
55
56 void
platform_pre_restart(void)57 platform_pre_restart(void)
58 {
59 #ifdef LINUX_OOM_ADJUST
60 oom_adjust_restore();
61 #endif
62 }
63
64 void
platform_post_fork_parent(pid_t child_pid)65 platform_post_fork_parent(pid_t child_pid)
66 {
67 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
68 solaris_contract_post_fork_parent(child_pid);
69 #endif
70 }
71
72 void
platform_post_fork_child(void)73 platform_post_fork_child(void)
74 {
75 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
76 solaris_contract_post_fork_child();
77 #endif
78 #ifdef LINUX_OOM_ADJUST
79 oom_adjust_restore();
80 #endif
81 }
82
83 /* return 1 if we are running with privilege to swap UIDs, 0 otherwise */
84 int
platform_privileged_uidswap(void)85 platform_privileged_uidswap(void)
86 {
87 #ifdef HAVE_CYGWIN
88 /* uid 0 is not special on Cygwin so always try */
89 return 1;
90 #else
91 return (getuid() == 0 || geteuid() == 0);
92 #endif
93 }
94
95 /*
96 * This gets called before switching UIDs, and is called even when sshd is
97 * not running as root.
98 */
99 void
platform_setusercontext(struct passwd * pw)100 platform_setusercontext(struct passwd *pw)
101 {
102 #ifdef WITH_SELINUX
103 /* Cache selinux status for later use */
104 (void)ssh_selinux_enabled();
105 #endif
106
107 #ifdef USE_SOLARIS_PROJECTS
108 /*
109 * If solaris projects were detected, set the default now, unless
110 * we are using PAM in which case it is the responsibility of the
111 * PAM stack.
112 */
113 if (!options.use_pam && (getuid() == 0 || geteuid() == 0))
114 solaris_set_default_project(pw);
115 #endif
116
117 #if defined(HAVE_LOGIN_CAP) && defined (__bsdi__)
118 if (getuid() == 0 || geteuid() == 0)
119 setpgid(0, 0);
120 # endif
121
122 #if defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
123 /*
124 * If we have both LOGIN_CAP and PAM, we want to establish creds
125 * before calling setusercontext (in session.c:do_setusercontext).
126 */
127 if (getuid() == 0 || geteuid() == 0) {
128 if (options.use_pam) {
129 do_pam_setcred(use_privsep);
130 }
131 }
132 # endif /* USE_PAM */
133
134 #if !defined(HAVE_LOGIN_CAP) && defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
135 if (getuid() == 0 || geteuid() == 0) {
136 /* Sets login uid for accounting */
137 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
138 error("setluid: %s", strerror(errno));
139 }
140 #endif
141 }
142
143 /*
144 * This gets called after we've established the user's groups, and is only
145 * called if sshd is running as root.
146 */
147 void
platform_setusercontext_post_groups(struct passwd * pw)148 platform_setusercontext_post_groups(struct passwd *pw)
149 {
150 #if !defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
151 /*
152 * PAM credentials may take the form of supplementary groups.
153 * These will have been wiped by the above initgroups() call.
154 * Reestablish them here.
155 */
156 if (options.use_pam) {
157 do_pam_setcred(use_privsep);
158 }
159 #endif /* USE_PAM */
160
161 #if !defined(HAVE_LOGIN_CAP) && (defined(WITH_IRIX_PROJECT) || \
162 defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY))
163 irix_setusercontext(pw);
164 #endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
165
166 #ifdef _AIX
167 aix_usrinfo(pw);
168 #endif /* _AIX */
169
170 #ifdef HAVE_SETPCRED
171 /*
172 * If we have a chroot directory, we set all creds except real
173 * uid which we will need for chroot. If we don't have a
174 * chroot directory, we don't override anything.
175 */
176 {
177 char **creds = NULL, *chroot_creds[] =
178 { "REAL_USER=root", NULL };
179
180 if (options.chroot_directory != NULL &&
181 strcasecmp(options.chroot_directory, "none") != 0)
182 creds = chroot_creds;
183
184 if (setpcred(pw->pw_name, creds) == -1)
185 fatal("Failed to set process credentials");
186 }
187 #endif /* HAVE_SETPCRED */
188 #ifdef WITH_SELINUX
189 ssh_selinux_setup_exec_context(pw->pw_name);
190 #endif
191 }
192
193 char *
platform_krb5_get_principal_name(const char * pw_name)194 platform_krb5_get_principal_name(const char *pw_name)
195 {
196 #ifdef USE_AIX_KRB_NAME
197 return aix_krb5_get_principal_name(pw_name);
198 #else
199 return NULL;
200 #endif
201 }
202
203 /*
204 * return 1 if the specified uid is a uid that may own a system directory
205 * otherwise 0.
206 */
207 int
platform_sys_dir_uid(uid_t uid)208 platform_sys_dir_uid(uid_t uid)
209 {
210 if (uid == 0)
211 return 1;
212 #ifdef PLATFORM_SYS_DIR_UID
213 if (uid == PLATFORM_SYS_DIR_UID)
214 return 1;
215 #endif
216 return 0;
217 }
218