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 int detach_from_console = -1;
  48 int daemon_child = -1;
  49 int do_bonjour = -1;
  50
  51 static RETSIGTYPE
  52 sigchld(int sig)
  53 {
  54 }
  55
  56 static RETSIGTYPE
  57 sigterm(int sig)
  58 {
  59     exit_flag = sig;
  60 }
  61
  62 /*
  63  * Allow dropping root bit, since heimdal reopens the database all the
  64  * time the database needs to be owned by the user you are switched
  65  * too. A better solution is to split the kdc in to more processes and
  66  * run the network facing part with very low privilege.
  67  */
  68
  69 static void
  70 switch_environment(void)
  71 {
  72 #ifdef HAVE_GETEUID
  73     if ((runas_string || chroot_string) && geteuid() != 0)
  74         errx(1, "no running as root, can't switch user/chroot");
  75
  76     if (chroot_string) {
  77         if (chroot(chroot_string))
  78             err(1, "chroot(%s) failed", chroot_string);
  79         if (chdir("/"))
  80             err(1, "chdir(/) after chroot failed");
  81     }
  82
  83     if (runas_string) {
  84         struct passwd *pw;
  85
  86         pw = getpwnam(runas_string);
  87         if (pw == NULL)
  88             errx(1, "unknown user %s", runas_string);
  89
  90         if (initgroups(pw->pw_name, pw->pw_gid) < 0)
  91             err(1, "initgroups failed");
  92
  93 #ifndef HAVE_CAPNG
  94         if (setgid(pw->pw_gid) < 0)
  95             err(1, "setgid(%s) failed", runas_string);
  96
  97         if (setuid(pw->pw_uid) < 0)
  98             err(1, "setuid(%s)", runas_string);
  99 #else
 100         capng_clear (CAPNG_EFFECTIVE | CAPNG_PERMITTED);
 101         if (capng_updatev (CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
 102                            CAP_NET_BIND_SERVICE, CAP_SETPCAP, -1) < 0)
 103             err(1, "capng_updateev");
 104
 105         if (capng_change_id(pw->pw_uid, pw->pw_gid,
 106                             CAPNG_CLEAR_BOUNDING) < 0)
 107             err(1, "capng_change_id(%s)", runas_string);
 108 #endif
 109     }
 110 #endif
 111 }
 112
 113 int
 114 main(int argc, char **argv)
 115 {
 116     krb5_error_code ret;
 117     krb5_context context;
 118     krb5_kdc_configuration *config;
 119     int optidx = 0;
 120
 121     setprogname(argv[0]);
 122
 123     ret = krb5_init_context(&context);
 124     if (ret == KRB5_CONFIG_BADFORMAT)
 125         errx (1, "krb5_init_context failed to parse configuration file");
 126     else if (ret)
 127         errx (1, "krb5_init_context failed: %d", ret);
 128
 129     ret = krb5_kt_register(context, &hdb_get_kt_ops);
 130     if (ret)
 131         errx (1, "krb5_kt_register(HDB) failed: %d", ret);
 132
 133     config = configure(context, argc, argv, &optidx);
 134
 135 #ifdef HAVE_SIGACTION
 136     {
 137         struct sigaction sa;
 138
 139         sa.sa_flags = 0;
 140         sa.sa_handler = sigterm;
 141         sigemptyset(&sa.sa_mask);
 142
 143         sigaction(SIGINT, &sa, NULL);
 144         sigaction(SIGTERM, &sa, NULL);
 145 #ifdef SIGXCPU
 146         sigaction(SIGXCPU, &sa, NULL);
 147 #endif
 148
 149 #ifdef SIGCHLD
 150         sa.sa_handler = sigchld;
 151         sigaction(SIGCHLD, &sa, NULL);
 152 #endif
 153
 154         sa.sa_handler = SIG_IGN;
 155 #ifdef SIGPIPE
 156         sigaction(SIGPIPE, &sa, NULL);
 157 #endif
 158     }
 159 #else
 160     signal(SIGINT, sigterm);
 161     signal(SIGTERM, sigterm);
 162 #ifdef SIGCHLD
 163     signal(SIGCHLD, sigchld);
 164 #endif
 165 #ifdef SIGXCPU
 166     signal(SIGXCPU, sigterm);
 167 #endif
 168 #ifdef SIGPIPE
 169     signal(SIGPIPE, SIG_IGN);
 170 #endif
 171 #endif
 172     pidfile(NULL);
 173
 174     switch_environment();
 175
 176     start_kdc(context, config, argv[0]);
 177     krb5_free_context(context);
 178     return 0;
 179 }