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