1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * netcfgd - network configuration daemon. At present, this daemon implements
29 * the configuration backend for libnwam (via calls to nwam_backend_init()
30 * and nwam_backend_fini()). Initialization of the backend creates a door
31 * that libnwam calls use to read, update and destroy persistent configuration.
32 *
33 * More long-term, netcfgd will be used to manage other sources of configuration
34 * data and the backend functionality currently contained in libnwam will be
35 * generalized.
36 */
37
38 #include <errno.h>
39 #include <signal.h>
40 #include <stdio.h>
41 #include <stdarg.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <syslog.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <unistd.h>
48 #include <wait.h>
49 #include <libnwam_priv.h>
50 #include <libnwam.h>
51
52 static const char *progname;
53 static boolean_t fg = B_FALSE;
54
55 /*
56 * This function allows you to drop a dtrace probe here and trace
57 * complete strings (not just those containing formatting). It's
58 * important that we actually format the strings so we could trace them
59 * even if we choose not to log them.
60 */
61 static void
log_out(int severity,const char * str)62 log_out(int severity, const char *str)
63 {
64 if (fg) {
65 (void) fprintf(stderr, "%s: %s\n", progname, str);
66 } else {
67 syslog(severity, str);
68 }
69 }
70
71 /* PRINTFLIKE2 */
72 void
nlog(int severity,const char * fmt,...)73 nlog(int severity, const char *fmt, ...)
74 {
75 va_list ap;
76 char *vbuf;
77
78 va_start(ap, fmt);
79 if (vasprintf(&vbuf, fmt, ap) != -1) {
80 log_out(severity, vbuf);
81 free(vbuf);
82 }
83 va_end(ap);
84 }
85
86 static void
start_logging(void)87 start_logging(void)
88 {
89 if (!fg)
90 openlog(progname, LOG_PID, LOG_DAEMON);
91
92 nlog(LOG_DEBUG, "%s started", progname);
93 }
94
95 static void
daemonize(void)96 daemonize(void)
97 {
98 pid_t pid;
99
100 /*
101 * A little bit of magic here. By the first fork+setsid, we
102 * disconnect from our current controlling terminal and become
103 * a session group leader. By forking again without calling
104 * setsid again, we make certain that we are not the session
105 * group leader and can never reacquire a controlling terminal.
106 */
107 if ((pid = fork()) == -1) {
108 nlog(LOG_ERR, "fork 1 failed");
109 exit(EXIT_FAILURE);
110 }
111 if (pid != 0) {
112 (void) wait(NULL);
113 nlog(LOG_DEBUG, "child %ld exited, daemonizing", pid);
114 _exit(0);
115 }
116 if (setsid() == (pid_t)-1) {
117 nlog(LOG_ERR, "setsid");
118 exit(EXIT_FAILURE);
119 }
120 if ((pid = fork()) == -1) {
121 nlog(LOG_ERR, "fork 2 failed");
122 exit(EXIT_FAILURE);
123 }
124 if (pid != 0) {
125 _exit(0);
126 }
127 (void) chdir("/");
128 (void) umask(022);
129 }
130
131 /* ARGSUSED */
132 static void
graceful_shutdown(int signo)133 graceful_shutdown(int signo)
134 {
135 nwam_backend_fini();
136 exit(EXIT_SUCCESS);
137 }
138
139 int
main(int argc,char * argv[])140 main(int argc, char *argv[])
141 {
142 int c;
143 nwam_error_t err;
144
145 if ((progname = strrchr(argv[0], '/')) == NULL)
146 progname = argv[0];
147 else
148 progname++;
149
150 while ((c = getopt(argc, argv, "f")) != -1) {
151 switch (c) {
152 case 'f':
153 fg = B_TRUE;
154 break;
155 default:
156 (void) fprintf(stderr, "%s: unrecognized option %c\n",
157 progname, optopt);
158 exit(EXIT_FAILURE);
159 }
160 }
161 start_logging();
162
163 if (!fg)
164 daemonize();
165
166 (void) signal(SIGTERM, graceful_shutdown);
167 (void) signal(SIGQUIT, graceful_shutdown);
168 (void) signal(SIGPIPE, SIG_IGN);
169 (void) signal(SIGCHLD, SIG_IGN);
170 (void) atexit(nwam_backend_fini);
171
172 if ((err = nwam_backend_init()) != NWAM_SUCCESS) {
173 nlog(LOG_ERR,
174 "couldn't initialize libnwam backend: %s",
175 nwam_strerror(err));
176 exit(EXIT_FAILURE);
177 }
178
179 for (;;)
180 (void) pause();
181
182 /* NOTREACHED */
183 return (EXIT_SUCCESS);
184 }
185