1/*	$NetBSD$	*/
2
3/*
4 * Copyright (c) 1997-2005 Kungliga Tekniska H��gskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 *
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 *
21 * 3. Neither the name of the Institute nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38#include "kdc_locl.h"
39#ifdef HAVE_UTIL_H
40#include <util.h>
41#endif
42
43#ifdef HAVE_CAPNG
44#include <cap-ng.h>
45#endif
46
47sig_atomic_t exit_flag = 0;
48
49#ifdef SUPPORT_DETACH
50int detach_from_console = -1;
51#endif
52
53static RETSIGTYPE
54sigterm(int sig)
55{
56    exit_flag = sig;
57}
58
59/*
60 * Allow dropping root bit, since heimdal reopens the database all the
61 * time the database needs to be owned by the user you are switched
62 * too. A better solution is to split the kdc in to more processes and
63 * run the network facing part with very low privilege.
64 */
65
66static void
67switch_environment(void)
68{
69#ifdef HAVE_GETEUID
70    if ((runas_string || chroot_string) && geteuid() != 0)
71	errx(1, "no running as root, can't switch user/chroot");
72
73    if (chroot_string && chroot(chroot_string) != 0)
74	errx(1, "chroot(%s)", "chroot_string failed");
75
76    if (runas_string) {
77	struct passwd *pw;
78
79	pw = getpwnam(runas_string);
80	if (pw == NULL)
81	    errx(1, "unknown user %s", runas_string);
82
83	if (initgroups(pw->pw_name, pw->pw_gid) < 0)
84	    err(1, "initgroups failed");
85
86#ifndef HAVE_CAPNG
87	if (setgid(pw->pw_gid) < 0)
88	    err(1, "setgid(%s) failed", runas_string);
89
90	if (setuid(pw->pw_uid) < 0)
91	    err(1, "setuid(%s)", runas_string);
92#else
93	capng_clear (CAPNG_EFFECTIVE | CAPNG_PERMITTED);
94	if (capng_updatev (CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
95	                   CAP_NET_BIND_SERVICE, CAP_SETPCAP, -1) < 0)
96	    err(1, "capng_updateev");
97
98	if (capng_change_id(pw->pw_uid, pw->pw_gid,
99	                    CAPNG_CLEAR_BOUNDING) < 0)
100	    err(1, "capng_change_id(%s)", runas_string);
101#endif
102    }
103#endif
104}
105
106
107int
108main(int argc, char **argv)
109{
110    krb5_error_code ret;
111    krb5_context context;
112    krb5_kdc_configuration *config;
113
114    setprogname(argv[0]);
115
116    ret = krb5_init_context(&context);
117    if (ret == KRB5_CONFIG_BADFORMAT)
118	errx (1, "krb5_init_context failed to parse configuration file");
119    else if (ret)
120	errx (1, "krb5_init_context failed: %d", ret);
121
122    ret = krb5_kt_register(context, &hdb_kt_ops);
123    if (ret)
124	errx (1, "krb5_kt_register(HDB) failed: %d", ret);
125
126    config = configure(context, argc, argv);
127
128#ifdef HAVE_SIGACTION
129    {
130	struct sigaction sa;
131
132	sa.sa_flags = 0;
133	sa.sa_handler = sigterm;
134	sigemptyset(&sa.sa_mask);
135
136	sigaction(SIGINT, &sa, NULL);
137	sigaction(SIGTERM, &sa, NULL);
138#ifdef SIGXCPU
139	sigaction(SIGXCPU, &sa, NULL);
140#endif
141
142	sa.sa_handler = SIG_IGN;
143#ifdef SIGPIPE
144	sigaction(SIGPIPE, &sa, NULL);
145#endif
146    }
147#else
148    signal(SIGINT, sigterm);
149    signal(SIGTERM, sigterm);
150#ifdef SIGXCPU
151    signal(SIGXCPU, sigterm);
152#endif
153#ifdef SIGPIPE
154    signal(SIGPIPE, SIG_IGN);
155#endif
156#endif
157#ifdef SUPPORT_DETACH
158    if (detach_from_console)
159	daemon(0, 0);
160#endif
161#ifdef __APPLE__
162    bonjour_announce(context, config);
163#endif
164    pidfile(NULL);
165
166    switch_environment();
167
168    loop(context, config);
169    krb5_free_context(context);
170    return 0;
171}
172