usr.sbin/sdpd/main.c

   1 /*      $NetBSD: main.c,v 1.6 2009/08/13 17:50:41 drochner Exp $        */
   2
   3 /*-
   4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
   5  * Copyright (c) 2004 Maksim Yevmenkin <m_evmenkin@yahoo.com>
   6  * 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  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  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  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/usr.sbin/bluetooth/sdpd/main.c,v 1.1 2004/01/20 20:48:26 emax Exp $
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __COPYRIGHT("@(#) Copyright (c) 2009 The NetBSD Foundation, Inc.\
  34   Copyright (c) 2006 Itronix, Inc.\
  35   Copyright (c) 2004 Maksim Yevmenkin m_evmenkin@yahoo.com.\
  36   All rights reserved.");
  37 __RCSID("$NetBSD: main.c,v 1.6 2009/08/13 17:50:41 drochner Exp $");
  38
  39 #include <errno.h>
  40 #include <grp.h>
  41 #include <pwd.h>
  42 #include <signal.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47
  48 #include "sdpd.h"
  49
  50 #define SDPD                    "sdpd"
  51
  52 static bool     drop_root       (char const *user, char const *group);
  53 static void     sighandler      (int s);
  54 static void     usage           (void);
  55
  56 static bool     done;
  57
  58 /*
  59  * Bluetooth Service Discovery Procotol (SDP) daemon
  60  */
  61
  62 int
  63 main(int argc, char *argv[])
  64 {
  65         server_t                 server;
  66         char const              *control = SDP_LOCAL_PATH;
  67         char const              *user = "_sdpd", *group = "_sdpd";
  68         char const              *sgroup = NULL;
  69         int                      opt;
  70         bool                     detach = true;
  71         struct sigaction         sa;
  72
  73         while ((opt = getopt(argc, argv, "c:dG:g:hu:")) != -1) {
  74                 switch (opt) {
  75                 case 'c': /* control */
  76                         control = optarg;
  77                         break;
  78
  79                 case 'd': /* do not detach */
  80                         detach = false;
  81                         break;
  82
  83                 case 'G': /* super group */
  84                         sgroup = optarg;
  85                         break;
  86
  87                 case 'g': /* group */
  88                         group = optarg;
  89                         break;
  90
  91                 case 'u': /* user */
  92                         user = optarg;
  93                         break;
  94
  95                 case 'h':
  96                 default:
  97                         usage();
  98                         /* NOT REACHED */
  99                 }
 100         }
 101
 102         log_open(SDPD, !detach);
 103
 104         /* Become daemon if required */
 105         if (detach && daemon(0, 0) < 0) {
 106                 log_crit("Could not become daemon. %s (%d)",
 107                     strerror(errno), errno);
 108
 109                 exit(EXIT_FAILURE);
 110         }
 111
 112         /* Set signal handlers */
 113         memset(&sa, 0, sizeof(sa));
 114         sa.sa_handler = sighandler;
 115
 116         if (sigaction(SIGTERM, &sa, NULL) < 0
 117             || sigaction(SIGHUP,  &sa, NULL) < 0
 118             || sigaction(SIGINT,  &sa, NULL) < 0) {
 119                 log_crit("Could not install signal handlers. %s (%d)",
 120                     strerror(errno), errno);
 121
 122                 exit(EXIT_FAILURE);
 123         }
 124
 125         sa.sa_handler = SIG_IGN;
 126         if (sigaction(SIGPIPE, &sa, NULL) < 0) {
 127                 log_crit("Could not install signal handlers. %s (%d)",
 128                     strerror(errno), errno);
 129
 130                 exit(EXIT_FAILURE);
 131         }
 132
 133         /* Initialize server */
 134         if (!server_init(&server, control, sgroup))
 135                 exit(EXIT_FAILURE);
 136
 137         if ((user != NULL || group != NULL) && !drop_root(user, group))
 138                 exit(EXIT_FAILURE);
 139
 140         for (done = 0; !done; ) {
 141                 if (!server_do(&server))
 142                         done++;
 143         }
 144
 145         server_shutdown(&server);
 146         log_close();
 147
 148         exit(EXIT_SUCCESS);
 149 }
 150
 151 /*
 152  * Drop root
 153  */
 154
 155 static bool
 156 drop_root(char const *user, char const *group)
 157 {
 158         int      uid, gid;
 159         char    *ep;
 160
 161         if ((uid = getuid()) != 0) {
 162                 log_notice("Cannot set uid/gid. Not a superuser");
 163                 return true; /* dont do anything unless root */
 164         }
 165
 166         gid = getgid();
 167
 168         if (user != NULL) {
 169                 uid = strtol(user, &ep, 10);
 170                 if (*ep != '\0') {
 171                         struct passwd   *pwd = getpwnam(user);
 172
 173                         if (pwd == NULL) {
 174                                 log_err("No passwd entry for user %s", user);
 175                                 return false;
 176                         }
 177
 178                         uid = pwd->pw_uid;
 179                 }
 180         }
 181
 182         if (group != NULL) {
 183                 gid = strtol(group, &ep, 10);
 184                 if (*ep != '\0') {
 185                         struct group    *grp = getgrnam(group);
 186
 187                         if (grp == NULL) {
 188                                 log_err("No group entry for group %s", group);
 189                                 return false;
 190                         }
 191
 192                         gid = grp->gr_gid;
 193                 }
 194         }
 195
 196         if (setgid(gid) < 0) {
 197                 log_err("Could not setgid(%s). %s (%d)", group,
 198                     strerror(errno), errno);
 199
 200                 return false;
 201         }
 202
 203         if (setgroups(0, NULL) < 0) {
 204                 log_err("Could not setgroups(0). %s (%d)",
 205                     strerror(errno), errno);
 206
 207                 return false;
 208         }
 209
 210         if (setuid(uid) < 0) {
 211                 log_err("Could not setuid(%s). %s (%d)", user,
 212                     strerror(errno), errno);
 213
 214                 return false;
 215         }
 216
 217         return true;
 218 }
 219
 220 /*
 221  * Signal handler
 222  */
 223
 224 static void
 225 sighandler(int s)
 226 {
 227
 228         log_notice("Got signal %d. Total number of signals received %d",
 229                 s, ++done);
 230 }
 231
 232 /*
 233  * Display usage information and quit
 234  */
 235
 236 static void
 237 usage(void)
 238 {
 239
 240         fprintf(stderr, "Usage: %s [options]\n"
 241                         "Where options are:\n"
 242                         "\t-c       specify control socket name (default %s)\n"
 243                         "\t-d       do not detach (run in foreground)\n"
 244                         "\t-G grp   allow privileges to group\n"
 245                         "\t-g grp   specify group\n"
 246                         "\t-h       display usage and exit\n"
 247                         "\t-u usr   specify user\n"
 248                         "", SDPD, SDP_LOCAL_PATH);
 249
 250         exit(EXIT_FAILURE);
 251 }