1/*	$NetBSD: main.c,v 1.10 2019/02/04 04:56:35 mrg 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 1.10 2019/02/04 04:56:35 mrg 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
52static bool	drop_root	(char const *user, char const *group);
53static void	sighandler	(int s);
54__dead static void	usage		(void);
55
56static unsigned	done;
57
58/*
59 * Bluetooth Service Discovery Procotol (SDP) daemon
60 */
61
62int
63main(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
155static bool
156drop_root(char const *user, char const *group)
157{
158	gid_t	gid;
159	uid_t	uid;
160	char	*ep;
161
162	if ((uid = getuid()) != 0) {
163		log_notice("Cannot set uid/gid. Not a superuser");
164		return true; /* dont do anything unless root */
165	}
166
167	gid = getgid();
168
169	if (user != NULL) {
170		uid = strtol(user, &ep, 10);
171		if (*ep != '\0') {
172			struct passwd	*pwd = getpwnam(user);
173
174			if (pwd == NULL) {
175				log_err("No passwd entry for user %s", user);
176				return false;
177			}
178
179			uid = pwd->pw_uid;
180		}
181	}
182
183	if (group != NULL) {
184		gid = strtol(group, &ep, 10);
185		if (*ep != '\0') {
186			struct group	*grp = getgrnam(group);
187
188			if (grp == NULL) {
189				log_err("No group entry for group %s", group);
190				return false;
191			}
192
193			gid = grp->gr_gid;
194		}
195	}
196
197	if (setgid(gid) < 0) {
198		log_err("Could not setgid(%s). %s (%d)", group,
199		    strerror(errno), errno);
200
201		return false;
202	}
203
204	if (setgroups(0, NULL) < 0) {
205		log_err("Could not setgroups(0). %s (%d)",
206		    strerror(errno), errno);
207
208		return false;
209	}
210
211	if (setuid(uid) < 0) {
212		log_err("Could not setuid(%s). %s (%d)", user,
213		    strerror(errno), errno);
214
215		return false;
216	}
217
218	return true;
219}
220
221/*
222 * Signal handler
223 */
224
225static void
226sighandler(int s)
227{
228
229	log_notice("Got signal %d. Total number of signals received %d",
230		s, ++done);
231}
232
233/*
234 * Display usage information and quit
235 */
236
237static void
238usage(void)
239{
240
241	fprintf(stderr, "Usage: %s [options]\n"
242			"Where options are:\n"
243			"\t-c       specify control socket name (default %s)\n"
244			"\t-d       do not detach (run in foreground)\n"
245			"\t-G grp   allow privileges to group\n"
246			"\t-g grp   specify group\n"
247			"\t-h       display usage and exit\n"
248			"\t-u usr   specify user\n"
249			"", SDPD, SDP_LOCAL_PATH);
250
251	exit(EXIT_FAILURE);
252}
253