1/* Disk protection for HP/DELL machines.
2 *
3 * Copyright 2008 Eric Piel
4 * Copyright 2009 Pavel Machek <pavel@ucw.cz>
5 * Copyright 2012 Sonal Santan
6 * Copyright 2014 Pali Rohár <pali.rohar@gmail.com>
7 *
8 * GPLv2.
9 */
10
11#include <stdio.h>
12#include <stdlib.h>
13#include <unistd.h>
14#include <fcntl.h>
15#include <sys/stat.h>
16#include <sys/types.h>
17#include <string.h>
18#include <stdint.h>
19#include <errno.h>
20#include <signal.h>
21#include <sys/mman.h>
22#include <sched.h>
23#include <syslog.h>
24
25static int noled;
26static char unload_heads_path[64];
27static char device_path[32];
28static const char app_name[] = "FREE FALL";
29
30static int set_unload_heads_path(char *device)
31{
32	if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0)
33		return -EINVAL;
34	strncpy(device_path, device, sizeof(device_path) - 1);
35
36	snprintf(unload_heads_path, sizeof(unload_heads_path) - 1,
37				"/sys/block/%s/device/unload_heads", device+5);
38	return 0;
39}
40
41static int valid_disk(void)
42{
43	int fd = open(unload_heads_path, O_RDONLY);
44
45	if (fd < 0) {
46		perror(unload_heads_path);
47		return 0;
48	}
49
50	close(fd);
51	return 1;
52}
53
54static void write_int(char *path, int i)
55{
56	char buf[1024];
57	int fd = open(path, O_RDWR);
58
59	if (fd < 0) {
60		perror("open");
61		exit(1);
62	}
63
64	sprintf(buf, "%d", i);
65
66	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
67		perror("write");
68		exit(1);
69	}
70
71	close(fd);
72}
73
74static void set_led(int on)
75{
76	if (noled)
77		return;
78	write_int("/sys/class/leds/hp::hddprotect/brightness", on);
79}
80
81static void protect(int seconds)
82{
83	const char *str = (seconds == 0) ? "Unparked" : "Parked";
84
85	write_int(unload_heads_path, seconds*1000);
86	syslog(LOG_INFO, "%s %s disk head\n", str, device_path);
87}
88
89static int on_ac(void)
90{
91	/* /sys/class/power_supply/AC0/online */
92	return 1;
93}
94
95static int lid_open(void)
96{
97	/* /proc/acpi/button/lid/LID/state */
98	return 1;
99}
100
101static void ignore_me(int signum)
102{
103	protect(0);
104	set_led(0);
105}
106
107int main(int argc, char **argv)
108{
109	int fd, ret;
110	struct stat st;
111	struct sched_param param;
112
113	if (argc == 1)
114		ret = set_unload_heads_path("/dev/sda");
115	else if (argc == 2)
116		ret = set_unload_heads_path(argv[1]);
117	else
118		ret = -EINVAL;
119
120	if (ret || !valid_disk()) {
121		fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n",
122				argv[0]);
123		exit(1);
124	}
125
126	fd = open("/dev/freefall", O_RDONLY);
127	if (fd < 0) {
128		perror("/dev/freefall");
129		return EXIT_FAILURE;
130	}
131
132	if (stat("/sys/class/leds/hp::hddprotect/brightness", &st))
133		noled = 1;
134
135	if (daemon(0, 0) != 0) {
136		perror("daemon");
137		return EXIT_FAILURE;
138	}
139
140	openlog(app_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
141
142	param.sched_priority = sched_get_priority_max(SCHED_FIFO);
143	sched_setscheduler(0, SCHED_FIFO, &param);
144	mlockall(MCL_CURRENT|MCL_FUTURE);
145
146	signal(SIGALRM, ignore_me);
147
148	for (;;) {
149		unsigned char count;
150
151		ret = read(fd, &count, sizeof(count));
152		alarm(0);
153		if ((ret == -1) && (errno == EINTR)) {
154			/* Alarm expired, time to unpark the heads */
155			continue;
156		}
157
158		if (ret != sizeof(count)) {
159			perror("read");
160			break;
161		}
162
163		protect(21);
164		set_led(1);
165		if (1 || on_ac() || lid_open())
166			alarm(2);
167		else
168			alarm(20);
169	}
170
171	closelog();
172	close(fd);
173	return EXIT_SUCCESS;
174}
175