1 /*	$OpenBSD: usbhidaction.c,v 1.27 2023/03/08 04:43:12 guenther Exp $ */
2 /*      $NetBSD: usbhidaction.c,v 1.7 2002/01/18 14:38:59 augustss Exp $ */
3 
4 /*
5  * Copyright (c) 2000, 2002 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Lennart Augustsson <lennart@augustsson.net>.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <ctype.h>
37 #include <err.h>
38 #include <fcntl.h>
39 #include <limits.h>
40 #include <unistd.h>
41 #include <sys/types.h>
42 #include <sys/ioctl.h>
43 #include <dev/usb/usb.h>
44 #include <dev/usb/usbhid.h>
45 #include <usbhid.h>
46 #include <syslog.h>
47 #include <signal.h>
48 #include <paths.h>
49 
50 int verbose = 0;
51 int isdemon = 0;
52 
53 volatile sig_atomic_t reparse = 0;
54 
55 struct command {
56 	struct command *next;
57 	int line;
58 
59 	struct hid_item item;
60 	int value;
61 	char anyvalue;
62 	char *name;
63 	char *action;
64 };
65 struct command *commands;
66 
67 #define SIZE 4000
68 
69 void usage(void);
70 struct command *parse_conf(const char *, report_desc_t, int, int);
71 void docmd(struct command *, int, const char *, int, char **);
72 void freecommands(struct command *);
73 
74 static void
sighup(int signo)75 sighup(int signo)
76 {
77 	reparse = 1;
78 }
79 
80 int
main(int argc,char ** argv)81 main(int argc, char **argv)
82 {
83 	const char *conf = NULL;
84 	const char *dev = NULL;
85 	int fd, ch, sz, n, val, i;
86 	int demon, ignore;
87 	report_desc_t repd;
88 	char buf[100];
89 	char devnamebuf[PATH_MAX];
90 	struct command *cmd;
91 	int reportid;
92 
93 	demon = 1;
94 	ignore = 0;
95 	while ((ch = getopt(argc, argv, "c:df:iv")) != -1) {
96 		switch(ch) {
97 		case 'c':
98 			conf = optarg;
99 			break;
100 		case 'd':
101 			demon ^= 1;
102 			break;
103 		case 'i':
104 			ignore++;
105 			break;
106 		case 'f':
107 			dev = optarg;
108 			break;
109 		case 'v':
110 			demon = 0;
111 			verbose++;
112 			break;
113 		default:
114 			usage();
115 		}
116 	}
117 	argc -= optind;
118 	argv += optind;
119 
120 	if (conf == NULL || dev == NULL)
121 		usage();
122 
123 	if (hid_start(NULL) == -1)
124 		errx(1, "hid_init");
125 
126 	if (dev[0] != '/') {
127 		snprintf(devnamebuf, sizeof(devnamebuf), "/dev/%s%s",
128 		    isdigit((unsigned char)dev[0]) ? "uhid" : "", dev);
129 		dev = devnamebuf;
130 	}
131 
132 	if (demon && conf[0] != '/')
133 		errx(1, "config file must have an absolute path, %s", conf);
134 
135 	fd = open(dev, O_RDWR | O_CLOEXEC);
136 	if (fd == -1)
137 		err(1, "%s", dev);
138 
139 	if (ioctl(fd, USB_GET_REPORT_ID, &reportid) == -1)
140 		reportid = -1;
141 	repd = hid_get_report_desc(fd);
142 	if (repd == NULL)
143 		err(1, "hid_get_report_desc() failed");
144 
145 	commands = parse_conf(conf, repd, reportid, ignore);
146 
147 	sz = hid_report_size(repd, hid_input, reportid);
148 
149 	if (verbose)
150 		printf("report size %d\n", sz);
151 	if (sz > sizeof buf)
152 		errx(1, "report too large");
153 
154 	(void)signal(SIGHUP, sighup);
155 
156 	/* we do not care about the children, so ignore them */
157 	(void)signal(SIGCHLD, SIG_IGN);
158 
159 	if (demon) {
160 		if (daemon(0, 0) == -1)
161 			err(1, "daemon()");
162 		isdemon = 1;
163 	}
164 
165 	if (unveil(conf, "r") == -1)
166 		err(1, "unveil %s", conf);
167 	if (unveil(_PATH_BSHELL, "x") == -1)
168 		err(1, "unveil %s", _PATH_BSHELL);
169 	if (unveil(NULL, NULL) == -1)
170 		err(1, "unveil");
171 
172 	for(;;) {
173 		n = read(fd, buf, sz);
174 		if (verbose > 2) {
175 			printf("read %d bytes:", n);
176 			for (i = 0; i < n; i++)
177 				printf(" %02x", buf[i]);
178 			printf("\n");
179 		}
180 		if (n == -1) {
181 			if (verbose)
182 				err(1, "read");
183 			else
184 				exit(1);
185 		}
186 		if (n != sz) {
187 			err(2, "read size");
188 		}
189 		for (cmd = commands; cmd; cmd = cmd->next) {
190 			val = hid_get_data(buf, &cmd->item);
191 			if (cmd->value == val || cmd->anyvalue)
192 				docmd(cmd, val, dev, argc, argv);
193 		}
194 		if (reparse) {
195 			struct command *cmds =
196 			    parse_conf(conf, repd, reportid, ignore);
197 			if (cmds) {
198 				freecommands(commands);
199 				commands = cmds;
200 			}
201 			reparse = 0;
202 		}
203 	}
204 
205 	exit(0);
206 }
207 
208 void
usage(void)209 usage(void)
210 {
211 	extern char *__progname;
212 
213 	fprintf(stderr, "usage: %s [-div] -c config-file -f device arg ...\n",
214 	    __progname);
215 	exit(1);
216 }
217 
218 static int
peek(FILE * f)219 peek(FILE *f)
220 {
221 	int c;
222 
223 	c = getc(f);
224 	if (c != EOF)
225 		ungetc(c, f);
226 	return c;
227 }
228 
229 struct command *
parse_conf(const char * conf,report_desc_t repd,int reportid,int ignore)230 parse_conf(const char *conf, report_desc_t repd, int reportid, int ignore)
231 {
232 	FILE *f;
233 	char *p;
234 	int line;
235 	char buf[SIZE], name[SIZE], value[SIZE], action[SIZE];
236 	char usage[SIZE], coll[SIZE];
237 	struct command *cmd, *cmds;
238 	struct hid_data *d;
239 	struct hid_item h;
240 	int u, lo, hi, range;
241 
242 	f = fopen(conf, "r");
243 	if (f == NULL)
244 		err(1, "%s", conf);
245 
246 	cmds = NULL;
247 	for (line = 1; ; line++) {
248 		if (fgets(buf, sizeof buf, f) == NULL)
249 			break;
250 		if (buf[0] == '#' || buf[0] == '\n')
251 			continue;
252 		p = strchr(buf, '\n');
253 		while (p && isspace(peek(f))) {
254 			if (fgets(p, sizeof buf - strlen(buf), f) == NULL)
255 				break;
256 			p = strchr(buf, '\n');
257 		}
258 		if (p)
259 			*p = 0;
260 		if (sscanf(buf, "%s %s %[^\n]", name, value, action) != 3) {
261 			if (isdemon) {
262 				syslog(LOG_WARNING, "config file `%s', line %d"
263 				    ", syntax error: %s", conf, line, buf);
264 				freecommands(cmds);
265 				fclose(f);
266 				return (NULL);
267 			} else {
268 				errx(1, "config file `%s', line %d"
269 				    ", syntax error: %s", conf, line, buf);
270 			}
271 		}
272 
273 		cmd = malloc(sizeof *cmd);
274 		if (cmd == NULL)
275 			err(1, "malloc failed");
276 		cmd->next = cmds;
277 		cmds = cmd;
278 		cmd->line = line;
279 
280 		if (strcmp(value, "*") == 0) {
281 			cmd->anyvalue = 1;
282 		} else {
283 			cmd->anyvalue = 0;
284 			if (sscanf(value, "%d", &cmd->value) != 1) {
285 				if (isdemon) {
286 					syslog(LOG_WARNING,
287 					    "config file `%s', line %d, "
288 					    "bad value: %s",
289 					    conf, line, value);
290 					freecommands(cmds);
291 					fclose(f);
292 					return (NULL);
293 				} else {
294 					errx(1, "config file `%s', line %d, "
295 					    "bad value: %s",
296 					    conf, line, value);
297 				}
298 			}
299 		}
300 
301 		coll[0] = 0;
302 		d = hid_start_parse(repd, 1 << hid_input, reportid);
303 		if (d == NULL)
304 			err(1, "hid_start_parse failed");
305 		while (hid_get_item(d, &h)) {
306 			if (verbose > 2)
307 				printf("kind=%d usage=%x\n", h.kind, h.usage);
308 			if (h.flags & HIO_CONST)
309 				continue;
310 			switch (h.kind) {
311 			case hid_input:
312 				if (h.usage_minimum != 0 ||
313 				    h.usage_maximum != 0) {
314 					lo = h.usage_minimum;
315 					hi = h.usage_maximum;
316 					range = 1;
317 				} else {
318 					lo = h.usage;
319 					hi = h.usage;
320 					range = 0;
321 				}
322 				for (u = lo; u <= hi; u++) {
323 					snprintf(usage, sizeof usage,  "%s:%s",
324 						 hid_usage_page(HID_PAGE(u)),
325 						 hid_usage_in_page(u));
326 					if (verbose > 2)
327 						printf("usage %s\n", usage);
328 					if (!strcasecmp(usage, name))
329 						goto foundhid;
330 					if (coll[0]) {
331 						snprintf(usage, sizeof usage,
332 						  "%s.%s:%s", coll+1,
333 						  hid_usage_page(HID_PAGE(u)),
334 						  hid_usage_in_page(u));
335 						if (verbose > 2)
336 							printf("usage %s\n",
337 							    usage);
338 						if (!strcasecmp(usage, name))
339 							goto foundhid;
340 					}
341 				}
342 				break;
343 			case hid_collection:
344 				snprintf(coll + strlen(coll),
345 				    sizeof coll - strlen(coll),  ".%s:%s",
346 				    hid_usage_page(HID_PAGE(h.usage)),
347 				    hid_usage_in_page(h.usage));
348 				break;
349 			case hid_endcollection:
350 				if (coll[0])
351 					*strrchr(coll, '.') = 0;
352 				break;
353 			default:
354 				break;
355 			}
356 		}
357 		hid_end_parse(d);
358 		if (ignore) {
359 			if (verbose)
360 				warnx("ignore item '%s'", name);
361 			/* pop and free this ignored item */
362 			cmds = cmd->next;
363 			free(cmd);
364 			continue;
365 		}
366 		if (isdemon) {
367 			syslog(LOG_WARNING, "config file `%s', line %d, HID "
368 			    "item not found: `%s'", conf, line, name);
369 			freecommands(cmds);
370 			fclose(f);
371 			return (NULL);
372 		} else {
373 			errx(1, "config file `%s', line %d, HID item "
374 			    "not found: `%s'", conf, line, name);
375 		}
376 
377 	foundhid:
378 		hid_end_parse(d);
379 		cmd->item = h;
380 		cmd->name = strdup(name);
381 		cmd->action = strdup(action);
382 		if (range) {
383 			if (cmd->value == 1)
384 				cmd->value = u - lo;
385 			else
386 				cmd->value = -1;
387 		}
388 
389 		if (verbose)
390 			printf("PARSE:%d %s, %d, '%s'\n", cmd->line, name,
391 			    cmd->value, cmd->action);
392 	}
393 	fclose(f);
394 	return (cmds);
395 }
396 
397 void
docmd(struct command * cmd,int value,const char * hid,int argc,char ** argv)398 docmd(struct command *cmd, int value, const char *hid, int argc, char **argv)
399 {
400 	char cmdbuf[SIZE], *p, *q;
401 	size_t len;
402 	int n, r;
403 	pid_t pid;
404 
405 	if (cmd->action == NULL) {
406 		if (verbose)
407 			printf("no action for device %s value %d\n",
408 			    hid, value);
409 		return;
410 	}
411 	for (p = cmd->action, q = cmdbuf; *p && q < &cmdbuf[SIZE-1]; ) {
412 		if (*p == '$') {
413 			p++;
414 			len = &cmdbuf[SIZE-1] - q;
415 			if (isdigit((unsigned char)*p)) {
416 				n = strtol(p, &p, 10) - 1;
417 				if (n >= 0 && n < argc) {
418 					strncpy(q, argv[n], len);
419 					q += strlen(q);
420 				}
421 			} else if (*p == 'V') {
422 				p++;
423 				snprintf(q, len, "%d", value);
424 				q += strlen(q);
425 			} else if (*p == 'N') {
426 				p++;
427 				strncpy(q, cmd->name, len);
428 				q += strlen(q);
429 			} else if (*p == 'H') {
430 				p++;
431 				strncpy(q, hid, len);
432 				q += strlen(q);
433 			} else if (*p) {
434 				*q++ = *p++;
435 			}
436 		} else {
437 			*q++ = *p++;
438 		}
439 	}
440 	*q = 0;
441 
442 	pid = fork();
443 	if (pid == -1)
444 		warn("fork failed");
445 	else if (pid == 0) {
446 		setpgid(0, 0);
447 		if (verbose)
448 			printf("executing '%s'\n", cmdbuf);
449 		r = execl(_PATH_BSHELL, "sh", "-c", cmdbuf, (char *)NULL);
450 		err(1, "execl");
451 	}
452 }
453 
454 void
freecommands(struct command * cmd)455 freecommands(struct command *cmd)
456 {
457 	struct command *next;
458 
459 	while (cmd) {
460 		next = cmd->next;
461 		free(cmd);
462 		cmd = next;
463 	}
464 }
465