xref: /titanic_41/usr/src/cmd/fm/fmd/common/fmd_main.c (revision 726fad2a65f16c200a03969c29cb5c86c2d427db)
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  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <sys/wait.h>
29 #include <sys/corectl.h>
30 #include <sys/resource.h>
31 
32 #include <priv_utils.h>
33 #include <signal.h>
34 #include <unistd.h>
35 #include <limits.h>
36 #include <fcntl.h>
37 #include <strings.h>
38 #include <stdlib.h>
39 #include <stdio.h>
40 
41 #include <fmd_error.h>
42 #include <fmd_string.h>
43 #include <fmd_conf.h>
44 #include <fmd_dispq.h>
45 #include <fmd_subr.h>
46 #include <fmd.h>
47 
48 fmd_t fmd;
49 
50 /*
51  * For DEBUG builds, we define a set of hooks for libumem that provide useful
52  * default settings for the allocator's debugging facilities.
53  */
54 #ifdef	DEBUG
55 const char *
56 _umem_debug_init()
57 {
58 	return ("default,verbose"); /* $UMEM_DEBUG setting */
59 }
60 
61 const char *
62 _umem_logging_init(void)
63 {
64 	return ("fail,contents"); /* $UMEM_LOGGING setting */
65 }
66 #endif	/* DEBUG */
67 
68 /*
69  * We use a two-phase algorithm for becoming a daemon because we want the
70  * daemon process (the child) to do the work of becoming MT-hot and opening our
71  * event transport.  Since these operations can fail and need to result in the
72  * daemon failing to start, the parent must wait until fmd_run() completes to
73  * know whether it can return zero or non-zero status to the invoking command.
74  * The parent waits on a pipe inside this function to read the exit status.
75  * The child gets the write-end of the pipe returned by daemonize_init() and
76  * then fmd_run() uses the pipe to set the exit status and detach the parent.
77  */
78 static int
79 daemonize_init(void)
80 {
81 	int status, pfds[2];
82 	sigset_t set, oset;
83 	struct rlimit rlim;
84 	char path[PATH_MAX];
85 	pid_t pid;
86 
87 	/*
88 	 * Set our per-process core file path to leave core files in our
89 	 * var/fm/fmd directory, named after the PID to aid in debugging,
90 	 * and make sure that there is no restriction on core file size.
91 	 */
92 	(void) snprintf(path, sizeof (path),
93 	    "%s/var/fm/fmd/core.%s.%%p", fmd.d_rootdir, fmd.d_pname);
94 
95 	(void) core_set_process_path(path, strlen(path) + 1, fmd.d_pid);
96 
97 	rlim.rlim_cur = RLIM_INFINITY;
98 	rlim.rlim_max = RLIM_INFINITY;
99 
100 	(void) setrlimit(RLIMIT_CORE, &rlim);
101 
102 	/*
103 	 * Claim all the file descriptors we can.
104 	 */
105 	if (getrlimit(RLIMIT_NOFILE, &rlim) == 0) {
106 		rlim.rlim_cur = rlim.rlim_max;
107 		(void) setrlimit(RLIMIT_NOFILE, &rlim);
108 	}
109 
110 	/*
111 	 * Reset all of our privilege sets to the minimum set of required
112 	 * privileges.  We continue to run as root so that files we create
113 	 * such as logs and checkpoints are secured in the /var filesystem.
114 	 */
115 	if (__init_daemon_priv(PU_RESETGROUPS | PU_LIMITPRIVS | PU_INHERITPRIVS,
116 	    0, 0, /* run as uid 0 and gid 0 */
117 	    PRIV_FILE_DAC_EXECUTE, PRIV_FILE_DAC_READ, PRIV_FILE_DAC_SEARCH,
118 	    PRIV_FILE_DAC_WRITE, PRIV_FILE_OWNER, PRIV_PROC_OWNER,
119 	    PRIV_PROC_PRIOCNTL, PRIV_SYS_ADMIN, PRIV_SYS_CONFIG,
120 	    PRIV_SYS_DEVICES, PRIV_SYS_RES_CONFIG, PRIV_NET_PRIVADDR,
121 	    PRIV_SYS_NET_CONFIG, NULL) != 0)
122 		fmd_error(EFMD_EXIT, "additional privileges required to run\n");
123 
124 	/*
125 	 * Block all signals prior to the fork and leave them blocked in the
126 	 * parent so we don't get in a situation where the parent gets SIGINT
127 	 * and returns non-zero exit status and the child is actually running.
128 	 * In the child, restore the signal mask once we've done our setsid().
129 	 */
130 	(void) sigfillset(&set);
131 	(void) sigdelset(&set, SIGABRT);
132 	(void) sigprocmask(SIG_BLOCK, &set, &oset);
133 
134 	if (pipe(pfds) == -1)
135 		fmd_error(EFMD_EXIT, "failed to create pipe for daemonize");
136 
137 	if ((pid = fork()) == -1)
138 		fmd_error(EFMD_EXIT, "failed to fork into background");
139 
140 	/*
141 	 * If we're the parent process, wait for either the child to send us
142 	 * the appropriate exit status over the pipe or for the read to fail
143 	 * (presumably with 0 for EOF if our child terminated abnormally).
144 	 * If the read fails, exit with either the child's exit status if it
145 	 * exited or with FMD_EXIT_ERROR if it died from a fatal signal.
146 	 */
147 	if (pid != 0) {
148 		(void) close(pfds[1]);
149 
150 		if (read(pfds[0], &status, sizeof (status)) == sizeof (status))
151 			_exit(status);
152 
153 		if (waitpid(pid, &status, 0) == pid && WIFEXITED(status))
154 			_exit(WEXITSTATUS(status));
155 
156 		_exit(FMD_EXIT_ERROR);
157 	}
158 
159 	fmd.d_pid = getpid();
160 	(void) setsid();
161 	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
162 	(void) chdir("/");
163 	(void) umask(022);
164 	(void) close(pfds[0]);
165 
166 	return (pfds[1]);
167 }
168 
169 static void
170 daemonize_fini(int fd)
171 {
172 	(void) close(fd);
173 
174 	if ((fd = open("/dev/null", O_RDWR)) >= 0) {
175 		(void) fcntl(fd, F_DUP2FD, STDIN_FILENO);
176 		(void) fcntl(fd, F_DUP2FD, STDOUT_FILENO);
177 		(void) fcntl(fd, F_DUP2FD, STDERR_FILENO);
178 		(void) close(fd);
179 	}
180 }
181 
182 static void
183 handler(int sig)
184 {
185 	if (fmd.d_signal == 0)
186 		fmd.d_signal = sig;
187 }
188 
189 static int
190 usage(const char *arg0, FILE *fp)
191 {
192 	(void) fprintf(fp,
193 	    "Usage: %s [-V] [-f file] [-o opt=val] [-R dir]\n", arg0);
194 
195 	return (FMD_EXIT_USAGE);
196 }
197 
198 int
199 main(int argc, char *argv[])
200 {
201 	const char *opt_f = NULL, *opt_R = NULL;
202 	const char optstr[] = "f:o:R:V";
203 	int c, pfd = -1, opt_V = 0;
204 	char *p;
205 
206 	struct sigaction act;
207 	sigset_t set;
208 
209 	/*
210 	 * Parse the command-line once to validate all options and retrieve
211 	 * any overrides for our configuration file and root directory.
212 	 */
213 	while ((c = getopt(argc, argv, optstr)) != EOF) {
214 		switch (c) {
215 		case 'f':
216 			opt_f = optarg;
217 			break;
218 		case 'o':
219 			break; /* handle -o below */
220 		case 'R':
221 			opt_R = optarg;
222 			break;
223 		case 'V':
224 			opt_V++;
225 			break;
226 		default:
227 			return (usage(argv[0], stderr));
228 		}
229 	}
230 
231 	if (optind < argc)
232 		return (usage(argv[0], stderr));
233 
234 	if (opt_V) {
235 #ifdef DEBUG
236 		const char *debug = " (DEBUG)";
237 #else
238 		const char *debug = "";
239 #endif
240 		(void) printf("%s: version %s%s\n",
241 		    argv[0], _fmd_version, debug);
242 		return (FMD_EXIT_SUCCESS);
243 	}
244 
245 	closefrom(STDERR_FILENO + 1);
246 	fmd_create(&fmd, argv[0], opt_R, opt_f);
247 
248 	/*
249 	 * Now that we've initialized our global state, parse the command-line
250 	 * again for any configuration options specified using -o and set them.
251 	 */
252 	for (optind = 1; (c = getopt(argc, argv, optstr)) != EOF; ) {
253 		if (c == 'o') {
254 			if ((p = strchr(optarg, '=')) == NULL) {
255 				(void) fprintf(stderr, "%s: failed to set "
256 				    "option -o %s: option requires value\n",
257 				    fmd.d_pname, optarg);
258 				return (FMD_EXIT_USAGE);
259 			}
260 
261 			*p++ = '\0'; /* strike out the delimiter */
262 
263 			if (p[0] == '"' && p[strlen(p) - 1] == '"') {
264 				p[strlen(p) - 1] = '\0';
265 				(void) fmd_stresc2chr(++p);
266 			}
267 
268 			if (fmd_conf_setprop(fmd.d_conf, optarg, p) != 0) {
269 				(void) fprintf(stderr,
270 				    "%s: failed to set option -o %s: %s\n",
271 				    fmd.d_pname, optarg, fmd_strerror(errno));
272 				return (FMD_EXIT_USAGE);
273 			}
274 		}
275 	}
276 
277 	if (fmd.d_fmd_debug & FMD_DBG_HELP) {
278 		fmd_help(&fmd);
279 		fmd_destroy(&fmd);
280 		return (FMD_EXIT_SUCCESS);
281 	}
282 
283 	/*
284 	 * Update the value of fmd.d_fg based on "fg" in case it changed.  We
285 	 * use this property to decide whether to daemonize below.
286 	 */
287 	(void) fmd_conf_getprop(fmd.d_conf, "fg", &fmd.d_fg);
288 
289 	/*
290 	 * Once we're done setting our global state up, set up signal handlers
291 	 * for ensuring orderly termination on SIGTERM.  If we are starting in
292 	 * the foreground, we also use the same handler for SIGINT and SIGHUP.
293 	 */
294 	(void) sigfillset(&set);
295 	(void) sigdelset(&set, SIGABRT); /* always unblocked for ASSERT() */
296 
297 	(void) sigfillset(&act.sa_mask);
298 	act.sa_handler = handler;
299 	act.sa_flags = 0;
300 
301 	(void) sigaction(SIGTERM, &act, NULL);
302 	(void) sigdelset(&set, SIGTERM);
303 
304 	if (fmd.d_fg) {
305 		(void) sigaction(SIGHUP, &act, NULL);
306 		(void) sigdelset(&set, SIGHUP);
307 		(void) sigaction(SIGINT, &act, NULL);
308 		(void) sigdelset(&set, SIGINT);
309 
310 		(void) sigdelset(&set, SIGTSTP);
311 		(void) sigdelset(&set, SIGTTIN);
312 		(void) sigdelset(&set, SIGTTOU);
313 
314 		(void) printf("%s: [ loading modules ... ", fmd.d_pname);
315 		(void) fflush(stdout);
316 	} else
317 		pfd = daemonize_init();
318 
319 	/*
320 	 * Prior to this point, we are single-threaded.  Once fmd_run() is
321 	 * called, we will be multi-threaded from this point on.  The daemon's
322 	 * main thread will wait at the end of this function for signals.
323 	 */
324 	fmd_run(&fmd, pfd);
325 
326 	if (fmd.d_fg) {
327 		(void) printf("done ]\n");
328 		(void) printf("%s: [ awaiting events ]\n", fmd.d_pname);
329 	} else
330 		daemonize_fini(pfd);
331 
332 	while (!fmd.d_signal)
333 		(void) sigsuspend(&set);
334 
335 	fmd_destroy(&fmd);
336 	return (FMD_EXIT_SUCCESS);
337 }
338