summaryrefslogtreecommitdiff
path: root/kdc/main.c
blob: f5355ed5babe313795ff129dbe2178eddaf99fcc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
/*
 * Copyright (c) 1997-2005 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "kdc_locl.h"
#ifdef HAVE_UTIL_H
#include <util.h>
#endif

#ifdef HAVE_CAPNG
#include <cap-ng.h>
#endif

sig_atomic_t exit_flag = 0;

int detach_from_console = -1;
int daemon_child = -1;
int do_bonjour = -1;

static RETSIGTYPE
sigchld(int sig)
{
}

static RETSIGTYPE
sigterm(int sig)
{
    exit_flag = sig;
}

/*
 * Allow dropping root bit, since heimdal reopens the database all the
 * time the database needs to be owned by the user you are switched
 * too. A better solution is to split the kdc in to more processes and
 * run the network facing part with very low privilege.
 */

static void
switch_environment(void)
{
#ifdef HAVE_GETEUID
    if ((runas_string || chroot_string) && geteuid() != 0)
	errx(1, "no running as root, can't switch user/chroot");

    if (chroot_string) {
	if (chroot(chroot_string))
	    err(1, "chroot(%s) failed", chroot_string);
	if (chdir("/"))
	    err(1, "chdir(/) after chroot failed");
    }

    if (runas_string) {
	struct passwd *pw;

	pw = getpwnam(runas_string);
	if (pw == NULL)
	    errx(1, "unknown user %s", runas_string);

	if (initgroups(pw->pw_name, pw->pw_gid) < 0)
	    err(1, "initgroups failed");

#ifndef HAVE_CAPNG
	if (setgid(pw->pw_gid) < 0)
	    err(1, "setgid(%s) failed", runas_string);

	if (setuid(pw->pw_uid) < 0)
	    err(1, "setuid(%s)", runas_string);
#else
	capng_clear (CAPNG_EFFECTIVE | CAPNG_PERMITTED);
	if (capng_updatev (CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
	                   CAP_NET_BIND_SERVICE, CAP_SETPCAP, -1) < 0)
	    err(1, "capng_updateev");

	if (capng_change_id(pw->pw_uid, pw->pw_gid,
	                    CAPNG_CLEAR_BOUNDING) < 0)
	    err(1, "capng_change_id(%s)", runas_string);
#endif
    }
#endif
}

int
main(int argc, char **argv)
{
    krb5_error_code ret;
    krb5_context context;
    krb5_kdc_configuration *config;
    int optidx = 0;

    setprogname(argv[0]);

    ret = krb5_init_context(&context);
    if (ret == KRB5_CONFIG_BADFORMAT)
	errx (1, "krb5_init_context failed to parse configuration file");
    else if (ret)
	errx (1, "krb5_init_context failed: %d", ret);

    ret = krb5_kt_register(context, &hdb_get_kt_ops);
    if (ret)
	errx (1, "krb5_kt_register(HDB) failed: %d", ret);

    config = configure(context, argc, argv, &optidx);

#ifdef HAVE_SIGACTION
    {
	struct sigaction sa;

	sa.sa_flags = 0;
	sa.sa_handler = sigterm;
	sigemptyset(&sa.sa_mask);

	sigaction(SIGINT, &sa, NULL);
	sigaction(SIGTERM, &sa, NULL);
#ifdef SIGXCPU
	sigaction(SIGXCPU, &sa, NULL);
#endif

#ifdef SIGCHLD
	sa.sa_handler = sigchld;
	sigaction(SIGCHLD, &sa, NULL);
#endif

	sa.sa_handler = SIG_IGN;
#ifdef SIGPIPE
	sigaction(SIGPIPE, &sa, NULL);
#endif
    }
#else
    signal(SIGINT, sigterm);
    signal(SIGTERM, sigterm);
#ifdef SIGCHLD
    signal(SIGCHLD, sigchld);
#endif
#ifdef SIGXCPU
    signal(SIGXCPU, sigterm);
#endif
#ifdef SIGPIPE
    signal(SIGPIPE, SIG_IGN);
#endif
#endif
    rk_pidfile(NULL);

    switch_environment();

    start_kdc(context, config, argv[0]);
    krb5_free_context(context);
    return 0;
}