xref: /netbsd-src/usr.sbin/sdpd/main.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: main.c,v 1.7 2009/08/30 19:24:40 plunky 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 1.7 2009/08/30 19:24:40 plunky 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 }
252