kdc/main.c

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