1 /* $Id: platform.c,v 1.18 2011/01/11 06:02:25 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 <sys/types.h>
22
23 #include <stdarg.h>
24 #include <unistd.h>
25
26 #include "log.h"
27 #include "buffer.h"
28 #include "servconf.h"
29 #include "key.h"
30 #include "hostfile.h"
31 #include "auth.h"
32 #include "auth-pam.h"
33 #include "platform.h"
34
35 #include "openbsd-compat/openbsd-compat.h"
36
37 extern int use_privsep;
38 extern ServerOptions options;
39
40 void
platform_pre_listen(void)41 platform_pre_listen(void)
42 {
43 #ifdef LINUX_OOM_ADJUST
44 /* Adjust out-of-memory killer so listening process is not killed */
45 oom_adjust_setup();
46 #endif
47 }
48
49 void
platform_pre_fork(void)50 platform_pre_fork(void)
51 {
52 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
53 solaris_contract_pre_fork();
54 #endif
55 }
56
57 void
platform_post_fork_parent(pid_t child_pid)58 platform_post_fork_parent(pid_t child_pid)
59 {
60 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
61 solaris_contract_post_fork_parent(child_pid);
62 #endif
63 }
64
65 void
platform_post_fork_child(void)66 platform_post_fork_child(void)
67 {
68 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
69 solaris_contract_post_fork_child();
70 #endif
71 #ifdef LINUX_OOM_ADJUST
72 oom_adjust_restore();
73 #endif
74 }
75
76 /* return 1 if we are running with privilege to swap UIDs, 0 otherwise */
77 int
platform_privileged_uidswap(void)78 platform_privileged_uidswap(void)
79 {
80 #ifdef HAVE_CYGWIN
81 /* uid 0 is not special on Cygwin so always try */
82 return 1;
83 #else
84 return (getuid() == 0 || geteuid() == 0);
85 #endif
86 }
87
88 /*
89 * This gets called before switching UIDs, and is called even when sshd is
90 * not running as root.
91 */
92 void
platform_setusercontext(struct passwd * pw)93 platform_setusercontext(struct passwd *pw)
94 {
95 #ifdef WITH_SELINUX
96 /* Cache selinux status for later use */
97 (void)ssh_selinux_enabled();
98 #endif
99
100 #ifdef USE_SOLARIS_PROJECTS
101 /* if solaris projects were detected, set the default now */
102 if (getuid() == 0 || geteuid() == 0)
103 solaris_set_default_project(pw);
104 #endif
105
106 #if defined(HAVE_LOGIN_CAP) && defined (__bsdi__)
107 if (getuid() == 0 || geteuid() == 0)
108 setpgid(0, 0);
109 # endif
110
111 #if defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
112 /*
113 * If we have both LOGIN_CAP and PAM, we want to establish creds
114 * before calling setusercontext (in session.c:do_setusercontext).
115 */
116 if (getuid() == 0 || geteuid() == 0) {
117 if (options.use_pam) {
118 do_pam_setcred(use_privsep);
119 }
120 }
121 # endif /* USE_PAM */
122
123 #if !defined(HAVE_LOGIN_CAP) && defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
124 if (getuid() == 0 || geteuid() == 0) {
125 /* Sets login uid for accounting */
126 if (getluid() == -1 && setluid(pw->pw_uid) == -1)
127 error("setluid: %s", strerror(errno));
128 }
129 #endif
130 }
131
132 /*
133 * This gets called after we've established the user's groups, and is only
134 * called if sshd is running as root.
135 */
136 void
platform_setusercontext_post_groups(struct passwd * pw)137 platform_setusercontext_post_groups(struct passwd *pw)
138 {
139 #if !defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
140 /*
141 * PAM credentials may take the form of supplementary groups.
142 * These will have been wiped by the above initgroups() call.
143 * Reestablish them here.
144 */
145 if (options.use_pam) {
146 do_pam_setcred(use_privsep);
147 }
148 #endif /* USE_PAM */
149
150 #if !defined(HAVE_LOGIN_CAP) && (defined(WITH_IRIX_PROJECT) || \
151 defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY))
152 irix_setusercontext(pw);
153 #endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
154
155 #ifdef _AIX
156 aix_usrinfo(pw);
157 #endif /* _AIX */
158
159 #if !defined(HAVE_LOGIN_CAP) && defined(USE_LIBIAF)
160 if (set_id(pw->pw_name) != 0) {
161 exit(1);
162 }
163 # endif /* USE_LIBIAF */
164
165 #ifdef HAVE_SETPCRED
166 /*
167 * If we have a chroot directory, we set all creds except real
168 * uid which we will need for chroot. If we don't have a
169 * chroot directory, we don't override anything.
170 */
171 {
172 char **creds = NULL, *chroot_creds[] =
173 { "REAL_USER=root", NULL };
174
175 if (options.chroot_directory != NULL &&
176 strcasecmp(options.chroot_directory, "none") != 0)
177 creds = chroot_creds;
178
179 if (setpcred(pw->pw_name, creds) == -1)
180 fatal("Failed to set process credentials");
181 }
182 #endif /* HAVE_SETPCRED */
183 #ifdef WITH_SELINUX
184 ssh_selinux_setup_exec_context(pw->pw_name);
185 #endif
186 }
187
188 char *
platform_krb5_get_principal_name(const char * pw_name)189 platform_krb5_get_principal_name(const char *pw_name)
190 {
191 #ifdef USE_AIX_KRB_NAME
192 return aix_krb5_get_principal_name(pw_name);
193 #else
194 return NULL;
195 #endif
196 }
197