xref: /netbsd-src/sbin/devpubd/devpubd.c (revision 31510453944a10501ce606a0b8c7e5d36d433e6e)
1 /*	$NetBSD: devpubd.c,v 1.7 2021/06/21 03:14:12 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2011 Jared D. McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by the NetBSD
18  *        Foundation, Inc. and its contributors.
19  * 4. Neither the name of The NetBSD Foundation nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __COPYRIGHT("@(#) Copyright (c) 2011-2015\
38 Jared D. McNeill <jmcneill@invisible.ca>. All rights reserved.");
39 __RCSID("$NetBSD: devpubd.c,v 1.7 2021/06/21 03:14:12 christos Exp $");
40 
41 #include <sys/queue.h>
42 #include <sys/types.h>
43 #include <sys/ioctl.h>
44 #include <sys/drvctlio.h>
45 #include <sys/wait.h>
46 
47 #include <assert.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <syslog.h>
55 #include <unistd.h>
56 
57 static int drvctl_fd = -1;
58 static const char devpubd_script[] = DEVPUBD_RUN_HOOKS;
59 
60 struct devpubd_probe_event {
61 	char *device;
62 	TAILQ_ENTRY(devpubd_probe_event) entries;
63 };
64 
65 static TAILQ_HEAD(, devpubd_probe_event) devpubd_probe_events;
66 
67 #define	DEVPUBD_ATTACH_EVENT	"device-attach"
68 #define	DEVPUBD_DETACH_EVENT	"device-detach"
69 
70 __dead static void
devpubd_exec(const char * path,char * const * argv)71 devpubd_exec(const char *path, char * const *argv)
72 {
73 	int error;
74 
75 	error = execv(path, argv);
76 	if (error) {
77 		syslog(LOG_ERR, "couldn't exec '%s': %m", path);
78 		exit(EXIT_FAILURE);
79 	}
80 
81 	exit(EXIT_SUCCESS);
82 }
83 
84 static void
devpubd_eventhandler(const char * event,const char ** device)85 devpubd_eventhandler(const char *event, const char **device)
86 {
87 	char **argv;
88 	pid_t pid;
89 	int status;
90 	size_t i, ndevs;
91 
92 	for (ndevs = 0, i = 0; device[i] != NULL; i++) {
93 		++ndevs;
94 		syslog(LOG_DEBUG, "event = '%s', device = '%s'", event,
95 		    device[i]);
96 	}
97 
98 	argv = calloc(3 + ndevs, sizeof(*argv));
99 	argv[0] = __UNCONST(devpubd_script);
100 	argv[1] = __UNCONST(event);
101 	for (i = 0; i < ndevs; i++) {
102 		argv[2 + i] = __UNCONST(device[i]);
103 	}
104 	argv[2 + i] = NULL;
105 
106 	pid = fork();
107 	switch (pid) {
108 	case -1:
109 		syslog(LOG_ERR, "fork failed: %m");
110 		break;
111 	case 0:
112 		devpubd_exec(devpubd_script, argv);
113 		/* NOTREACHED */
114 	default:
115 		if (waitpid(pid, &status, 0) == -1) {
116 			syslog(LOG_ERR, "waitpid(%d) failed: %m", pid);
117 			break;
118 		}
119 		if (WIFEXITED(status) && WEXITSTATUS(status)) {
120 			syslog(LOG_WARNING, "%s exited with status %d",
121 			    devpubd_script, WEXITSTATUS(status));
122 		} else if (WIFSIGNALED(status)) {
123 			syslog(LOG_WARNING, "%s received signal %d",
124 			    devpubd_script, WTERMSIG(status));
125 		}
126 		break;
127 	}
128 
129 	free(argv);
130 }
131 
132 __dead static void
devpubd_eventloop(void)133 devpubd_eventloop(void)
134 {
135 	const char *event, *device[2];
136 	prop_dictionary_t ev;
137 	int res;
138 
139 	assert(drvctl_fd != -1);
140 
141 	device[1] = NULL;
142 
143 	for (;;) {
144 		res = prop_dictionary_recv_ioctl(drvctl_fd, DRVGETEVENT, &ev);
145 		if (res)
146 			err(EXIT_FAILURE, "DRVGETEVENT failed");
147 		prop_dictionary_get_string(ev, "event", &event);
148 		prop_dictionary_get_string(ev, "device", &device[0]);
149 
150 		printf("%s: event='%s', device='%s'\n", __func__,
151 		    event, device[0]);
152 
153 		devpubd_eventhandler(event, device);
154 
155 		prop_object_release(ev);
156 	}
157 }
158 
159 static void
devpubd_probe(const char * device)160 devpubd_probe(const char *device)
161 {
162 	struct devlistargs laa;
163 	size_t len, children, n;
164 	void *p;
165 	int error;
166 
167 	assert(drvctl_fd != -1);
168 
169 	memset(&laa, 0, sizeof(laa));
170 	if (device)
171 		strlcpy(laa.l_devname, device, sizeof(laa.l_devname));
172 
173 	/* Get the child device count for this device */
174 	error = ioctl(drvctl_fd, DRVLISTDEV, &laa);
175 	if (error) {
176 		syslog(LOG_ERR, "DRVLISTDEV failed: %m");
177 		return;
178 	}
179 
180 child_count_changed:
181 	/* If this device has no children, return */
182 	if (laa.l_children == 0)
183 		return;
184 
185 	/* Allocate a buffer large enough to hold the child device names */
186 	p = laa.l_childname;
187 	children = laa.l_children;
188 
189 	len = children * sizeof(laa.l_childname[0]);
190 	laa.l_childname = realloc(laa.l_childname, len);
191 	if (laa.l_childname == NULL) {
192 		syslog(LOG_ERR, "couldn't allocate %zu bytes", len);
193 		laa.l_childname = p;
194 		goto done;
195 	}
196 
197 	/* Get a list of child devices */
198 	error = ioctl(drvctl_fd, DRVLISTDEV, &laa);
199 	if (error) {
200 		syslog(LOG_ERR, "DRVLISTDEV failed: %m");
201 		goto done;
202 	}
203 
204 	/* If the child count changed between DRVLISTDEV calls, retry */
205 	if (children != laa.l_children)
206 		goto child_count_changed;
207 
208 	/*
209 	 * For each child device, queue an attach event and
210 	 * then scan each one for additional devices.
211 	 */
212 	for (n = 0; n < laa.l_children; n++) {
213 		struct devpubd_probe_event *ev = calloc(1, sizeof(*ev));
214 		ev->device = strdup(laa.l_childname[n]);
215 		TAILQ_INSERT_TAIL(&devpubd_probe_events, ev, entries);
216 	}
217 	for (n = 0; n < laa.l_children; n++)
218 		devpubd_probe(laa.l_childname[n]);
219 
220 done:
221 	free(laa.l_childname);
222 	return;
223 }
224 
225 static void
devpubd_init(void)226 devpubd_init(void)
227 {
228 	struct devpubd_probe_event *ev;
229 	const char **devs;
230 	size_t ndevs, i;
231 
232 	TAILQ_INIT(&devpubd_probe_events);
233 	devpubd_probe(NULL);
234 	ndevs = 0;
235 	TAILQ_FOREACH(ev, &devpubd_probe_events, entries) {
236 		++ndevs;
237 	}
238 	devs = calloc(ndevs + 1, sizeof(*devs));
239 	i = 0;
240 	TAILQ_FOREACH(ev, &devpubd_probe_events, entries) {
241 		devs[i++] = ev->device;
242 	}
243 	devpubd_eventhandler(DEVPUBD_ATTACH_EVENT, devs);
244 	free(devs);
245 	while ((ev = TAILQ_FIRST(&devpubd_probe_events)) != NULL) {
246 		TAILQ_REMOVE(&devpubd_probe_events, ev, entries);
247 		free(ev->device);
248 		free(ev);
249 	}
250 }
251 
252 __dead static void
usage(void)253 usage(void)
254 {
255 	fprintf(stderr, "usage: %s [-1f]\n", getprogname());
256 	exit(EXIT_FAILURE);
257 }
258 
259 int
main(int argc,char * argv[])260 main(int argc, char *argv[])
261 {
262 	bool fflag = false;
263 	bool once = false;
264 	int ch;
265 
266 	setprogname(argv[0]);
267 
268 	while ((ch = getopt(argc, argv, "1fh")) != -1) {
269 		switch (ch) {
270 		case '1':
271 			fflag = true;
272 			once = true;
273 			break;
274 		case 'f':
275 			fflag = true;
276 			break;
277 		case 'h':
278 		default:
279 			usage();
280 			/* NOTREACHED */
281 		}
282 	}
283 	argc -= optind;
284 	argv += optind;
285 
286 	if (argc)
287 		usage();
288 		/* NOTREACHED */
289 
290 	drvctl_fd = open(DRVCTLDEV, O_RDWR);
291 	if (drvctl_fd == -1)
292 		err(EXIT_FAILURE, "couldn't open " DRVCTLDEV);
293 
294 	/* Look for devices that are already present */
295 	devpubd_init();
296 
297 	if (!fflag) {
298 		if (daemon(0, 0) == -1) {
299 			err(EXIT_FAILURE, "couldn't fork");
300 		}
301 	}
302 
303 	if (!once)
304 		devpubd_eventloop();
305 
306 	return EXIT_SUCCESS;
307 }
308