HardenedBSD/usr.bin/usbhidaction/usbhidaction.c

/*      $NetBSD: usbhidaction.c,v 1.8 2002/06/11 06:06:21 itojun Exp $ */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000, 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson <lennart@augustsson.net>.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <limits.h>
#include <unistd.h>
#include <sys/types.h>
#include <dev/usb/usbhid.h>
#include <usbhid.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>
#include <sys/stat.h>

static int	verbose = 0;
static int	isdemon = 0;
static int	reparse = 1;
static const char *	pidfile = "/var/run/usbaction.pid";

struct command {
	struct command *next;
	int line;

	struct hid_item item;
	int value;
	int lastseen;
	int lastused;
	int debounce;
	char anyvalue;
	char *name;
	char *action;
};
static struct command *commands;

#define SIZE 4000

void usage(void);
struct command *parse_conf(const char *, report_desc_t, int, int);
void docmd(struct command *, int, const char *, int, char **);
void freecommands(struct command *);

static void
sighup(int sig __unused)
{
	reparse = 1;
}

int
main(int argc, char **argv)
{
	const char *conf = NULL;
	const char *dev = NULL;
	const char *table = NULL;
	int fd, fp, ch, n, val, i;
	size_t sz, sz1;
	int demon, ignore, dieearly;
	report_desc_t repd;
	char buf[100];
	char devnamebuf[PATH_MAX];
	struct command *cmd;
	int reportid = -1;

	demon = 1;
	ignore = 0;
	dieearly = 0;
	while ((ch = getopt(argc, argv, "c:def:ip:r:t:v")) != -1) {
		switch(ch) {
		case 'c':
			conf = optarg;
			break;
		case 'd':
			demon ^= 1;
			break;
		case 'e':
			dieearly = 1;
			break;
		case 'i':
			ignore++;
			break;
		case 'f':
			dev = optarg;
			break;
		case 'p':
			pidfile = optarg;
			break;
		case 'r':
			reportid = atoi(optarg);
			break;
		case 't':
			table = optarg;
			break;
		case 'v':
			demon = 0;
			verbose++;
			break;
		case '?':
		default:
			usage();
		}
	}
	argc -= optind;
	argv += optind;

	if (conf == NULL || dev == NULL)
		usage();

	hid_init(table);

	if (dev[0] != '/') {
		snprintf(devnamebuf, sizeof(devnamebuf), "/dev/%s%s",
			 isdigit(dev[0]) ? "uhid" : "", dev);
		dev = devnamebuf;
	}

	fd = open(dev, O_RDWR);
	if (fd < 0)
		err(1, "%s", dev);
	repd = hid_get_report_desc(fd);
	if (repd == NULL)
		err(1, "hid_get_report_desc() failed");

	commands = parse_conf(conf, repd, reportid, ignore);

	sz = (size_t)hid_report_size(repd, hid_input, -1);

	if (verbose)
		printf("report size %zu\n", sz);
	if (sz > sizeof buf)
		errx(1, "report too large");

	(void)signal(SIGHUP, sighup);

	if (demon) {
		fp = open(pidfile, O_WRONLY|O_CREAT, S_IRUSR|S_IRGRP|S_IROTH);
		if (fp < 0)
			err(1, "%s", pidfile);
		if (daemon(0, 0) < 0)
			err(1, "daemon()");
		snprintf(buf, sizeof(buf), "%ld\n", (long)getpid());
		sz1 = strlen(buf);
		if (write(fp, buf, sz1) < 0)
			err(1, "%s", pidfile);
		close(fp);
		isdemon = 1;
	}

	for(;;) {
		n = read(fd, buf, sz);
		if (verbose > 2) {
			printf("read %d bytes:", n);
			for (i = 0; i < n; i++)
				printf(" %02x", buf[i]);
			printf("\n");
		}
		if (n < 0) {
			if (verbose)
				err(1, "read");
			else
				exit(1);
		}
#if 0
		if (n != sz) {
			err(2, "read size");
		}
#endif
		for (cmd = commands; cmd; cmd = cmd->next) {
			if (cmd->item.report_ID != 0 &&
			    buf[0] != cmd->item.report_ID)
				continue;
			if (cmd->item.flags & HIO_VARIABLE)
				val = hid_get_data(buf, &cmd->item);
			else {
				uint32_t pos = cmd->item.pos;
				for (i = 0; i < cmd->item.report_count; i++) {
					val = hid_get_data(buf, &cmd->item);
					if (val == cmd->value)
						break;
					cmd->item.pos += cmd->item.report_size;
				}
				cmd->item.pos = pos;
				val = (i < cmd->item.report_count) ?
				    cmd->value : -1;
			}
			if (cmd->value != val && cmd->anyvalue == 0)
				goto next;
			if ((cmd->debounce == 0) ||
			    ((cmd->debounce == 1) && ((cmd->lastseen == -1) ||
					       (cmd->lastseen != val)))) {
				docmd(cmd, val, dev, argc, argv);
				goto next;
			}
			if ((cmd->debounce > 1) &&
			    ((cmd->lastused == -1) ||
			     (abs(cmd->lastused - val) >= cmd->debounce))) {
				docmd(cmd, val, dev, argc, argv);
				cmd->lastused = val;
				goto next;
			}
next:
			cmd->lastseen = val;
		}

		if (dieearly)
			exit(0);

		if (reparse) {
			struct command *cmds =
			    parse_conf(conf, repd, reportid, ignore);
			if (cmds) {
				freecommands(commands);
				commands = cmds;
			}
			reparse = 0;
		}
	}

	exit(0);
}

void
usage(void)
{

	fprintf(stderr, "Usage: %s [-deiv] -c config_file -f hid_dev "
		"[-p pidfile] [-t tablefile]\n", getprogname());
	exit(1);
}

static int
peek(FILE *f)
{
	int c;

	c = getc(f);
	if (c != EOF)
		ungetc(c, f);
	return c;
}

struct command *
parse_conf(const char *conf, report_desc_t repd, int reportid, int ignore)
{
	FILE *f;
	char *p;
	int line;
	char buf[SIZE], name[SIZE], value[SIZE], debounce[SIZE], action[SIZE];
	char usbuf[SIZE], coll[SIZE], *tmp;
	struct command *cmd, *cmds;
	struct hid_data *d;
	struct hid_item h;
	int inst, cinst, u, lo, hi, range, t;

	f = fopen(conf, "r");
	if (f == NULL)
		err(1, "%s", conf);

	cmds = NULL;
	for (line = 1; ; line++) {
		if (fgets(buf, sizeof buf, f) == NULL)
			break;
		if (buf[0] == '#' || buf[0] == '\n')
			continue;
		p = strchr(buf, '\n');
		while (p && isspace(peek(f))) {
			if (fgets(p, sizeof buf - strlen(buf), f) == NULL)
				break;
			p = strchr(buf, '\n');
		}
		if (p)
			*p = 0;
		if (sscanf(buf, "%s %s %s %[^\n]",
			   name, value, debounce, action) != 4) {
			if (isdemon) {
				syslog(LOG_WARNING, "config file `%s', line %d"
				       ", syntax error: %s", conf, line, buf);
				freecommands(cmds);
				return (NULL);
			} else {
				errx(1, "config file `%s', line %d,"
				     ", syntax error: %s", conf, line, buf);
			}
		}
		tmp = strchr(name, '#');
		if (tmp != NULL) {
			*tmp = 0;
			inst = atoi(tmp + 1);
		} else
			inst = 0;

		cmd = malloc(sizeof *cmd);
		if (cmd == NULL)
			err(1, "malloc failed");
		cmd->next = cmds;
		cmds = cmd;
		cmd->line = line;

		if (strcmp(value, "*") == 0) {
			cmd->anyvalue = 1;
		} else {
			cmd->anyvalue = 0;
			if (sscanf(value, "%d", &cmd->value) != 1) {
				if (isdemon) {
					syslog(LOG_WARNING,
					       "config file `%s', line %d, "
					       "bad value: %s (should be * or a number)\n",
					       conf, line, value);
					freecommands(cmds);
					return (NULL);
				} else {
					errx(1, "config file `%s', line %d, "
					     "bad value: %s (should be * or a number)\n",
					     conf, line, value);
				}
			}
		}

		if (sscanf(debounce, "%d", &cmd->debounce) != 1) {
			if (isdemon) {
				syslog(LOG_WARNING,
				       "config file `%s', line %d, "
				       "bad value: %s (should be a number >= 0)\n",
				       conf, line, debounce);
				freecommands(cmds);
				return (NULL);
			} else {
				errx(1, "config file `%s', line %d, "
				     "bad value: %s (should be a number >= 0)\n",
				     conf, line, debounce);
			}
		}

		coll[0] = 0;
		cinst = 0;
		for (d = hid_start_parse(repd, 1 << hid_input, reportid);
		     hid_get_item(d, &h); ) {
			if (verbose > 2)
				printf("kind=%d usage=%x\n", h.kind, h.usage);
			if (h.flags & HIO_CONST)
				continue;
			switch (h.kind) {
			case hid_input:
				if (h.usage_minimum != 0 ||
				    h.usage_maximum != 0) {
					lo = h.usage_minimum;
					hi = h.usage_maximum;
					range = 1;
				} else {
					lo = h.usage;
					hi = h.usage;
					range = 0;
				}
				for (u = lo; u <= hi; u++) {
					if (coll[0]) {
						snprintf(usbuf, sizeof usbuf,
						  "%s.%s:%s", coll+1,
						  hid_usage_page(HID_PAGE(u)),
						  hid_usage_in_page(u));
					} else {
						snprintf(usbuf, sizeof usbuf,
						  "%s:%s",
						  hid_usage_page(HID_PAGE(u)),
						  hid_usage_in_page(u));
					}
					if (verbose > 2)
						printf("usage %s\n", usbuf);
					t = strlen(usbuf) - strlen(name);
					if (t > 0) {
						if (strcmp(usbuf + t, name))
							continue;
						if (usbuf[t - 1] != '.')
							continue;
					} else if (strcmp(usbuf, name))
						continue;
					if (inst == cinst++)
						goto foundhid;
				}
				break;
			case hid_collection:
				snprintf(coll + strlen(coll),
				    sizeof coll - strlen(coll),  ".%s:%s",
				    hid_usage_page(HID_PAGE(h.usage)), 
				    hid_usage_in_page(h.usage));
				break;
			case hid_endcollection:
				if (coll[0])
					*strrchr(coll, '.') = 0;
				break;
			default:
				break;
			}
		}
		if (ignore) {
			if (verbose)
				warnx("ignore item '%s'", name);
			continue;
		}
		if (isdemon) {
			syslog(LOG_WARNING, "config file `%s', line %d, HID "
			       "item not found: `%s'\n", conf, line, name);
			freecommands(cmds);
			return (NULL);
		} else {
			errx(1, "config file `%s', line %d, HID item "
			     "not found: `%s'\n", conf, line, name);
		}

	foundhid:
		hid_end_parse(d);
		cmd->lastseen = -1;
		cmd->lastused = -1;
		cmd->item = h;
		cmd->name = strdup(name);
		cmd->action = strdup(action);
		if (range) {
			if (cmd->value == 1)
				cmd->value = u - lo;
			else
				cmd->value = -1;
		}

		if (verbose)
			printf("PARSE:%d %s, %d, '%s'\n", cmd->line, name,
			       cmd->value, cmd->action);
	}
	fclose(f);
	return (cmds);
}

void
docmd(struct command *cmd, int value, const char *hid, int argc, char **argv)
{
	char cmdbuf[SIZE], *p, *q;
	size_t len;
	int n, r;

	for (p = cmd->action, q = cmdbuf; *p && q < &cmdbuf[SIZE-1]; ) {
		if (*p == '$') {
			p++;
			len = &cmdbuf[SIZE-1] - q;
			if (isdigit(*p)) {
				n = strtol(p, &p, 10) - 1;
				if (n >= 0 && n < argc) {
					strncpy(q, argv[n], len);
					q += strlen(q);
				}
			} else if (*p == 'V') {
				p++;
				snprintf(q, len, "%d", value);
				q += strlen(q);
			} else if (*p == 'N') {
				p++;
				strncpy(q, cmd->name, len);
				q += strlen(q);
			} else if (*p == 'H') {
				p++;
				strncpy(q, hid, len);
				q += strlen(q);
			} else if (*p) {
				*q++ = *p++;
			}
		} else {
			*q++ = *p++;
		}
	}
	*q = 0;

	if (verbose)
		printf("system '%s'\n", cmdbuf);
	r = system(cmdbuf);
	if (verbose > 1 && r)
		printf("return code = 0x%x\n", r);
}

void
freecommands(struct command *cmd)
{
	struct command *next;

	while (cmd) {
		next = cmd->next;
		free(cmd);
		cmd = next;
	}
}