1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Disk protection for HP/DELL machines.
3 *
4 * Copyright 2008 Eric Piel
5 * Copyright 2009 Pavel Machek <pavel@ucw.cz>
6 * Copyright 2012 Sonal Santan
7 * Copyright 2014 Pali Rohár <pali@kernel.org>
8 */
9
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <unistd.h>
13 #include <fcntl.h>
14 #include <sys/stat.h>
15 #include <sys/types.h>
16 #include <string.h>
17 #include <stdint.h>
18 #include <errno.h>
19 #include <signal.h>
20 #include <sys/mman.h>
21 #include <sched.h>
22 #include <syslog.h>
23
24 static int noled;
25 static char unload_heads_path[64];
26 static char device_path[32];
27 static const char app_name[] = "FREE FALL";
28
set_unload_heads_path(char * device)29 static int set_unload_heads_path(char *device)
30 {
31 if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0)
32 return -EINVAL;
33 strncpy(device_path, device, sizeof(device_path) - 1);
34
35 snprintf(unload_heads_path, sizeof(unload_heads_path) - 1,
36 "/sys/block/%s/device/unload_heads", device+5);
37 return 0;
38 }
39
valid_disk(void)40 static int valid_disk(void)
41 {
42 int fd = open(unload_heads_path, O_RDONLY);
43
44 if (fd < 0) {
45 perror(unload_heads_path);
46 return 0;
47 }
48
49 close(fd);
50 return 1;
51 }
52
write_int(char * path,int i)53 static void write_int(char *path, int i)
54 {
55 char buf[1024];
56 int fd = open(path, O_RDWR);
57
58 if (fd < 0) {
59 perror("open");
60 exit(1);
61 }
62
63 sprintf(buf, "%d", i);
64
65 if (write(fd, buf, strlen(buf)) != strlen(buf)) {
66 perror("write");
67 exit(1);
68 }
69
70 close(fd);
71 }
72
set_led(int on)73 static void set_led(int on)
74 {
75 if (noled)
76 return;
77 write_int("/sys/class/leds/hp::hddprotect/brightness", on);
78 }
79
protect(int seconds)80 static void protect(int seconds)
81 {
82 const char *str = (seconds == 0) ? "Unparked" : "Parked";
83
84 write_int(unload_heads_path, seconds*1000);
85 syslog(LOG_INFO, "%s %s disk head\n", str, device_path);
86 }
87
on_ac(void)88 static int on_ac(void)
89 {
90 /* /sys/class/power_supply/AC0/online */
91 return 1;
92 }
93
lid_open(void)94 static int lid_open(void)
95 {
96 /* /proc/acpi/button/lid/LID/state */
97 return 1;
98 }
99
ignore_me(int signum)100 static void ignore_me(int signum)
101 {
102 protect(0);
103 set_led(0);
104 }
105
main(int argc,char ** argv)106 int main(int argc, char **argv)
107 {
108 int fd, ret;
109 struct stat st;
110 struct sched_param param;
111
112 if (argc == 1)
113 ret = set_unload_heads_path("/dev/sda");
114 else if (argc == 2)
115 ret = set_unload_heads_path(argv[1]);
116 else
117 ret = -EINVAL;
118
119 if (ret || !valid_disk()) {
120 fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n",
121 argv[0]);
122 exit(1);
123 }
124
125 fd = open("/dev/freefall", O_RDONLY);
126 if (fd < 0) {
127 perror("/dev/freefall");
128 return EXIT_FAILURE;
129 }
130
131 if (stat("/sys/class/leds/hp::hddprotect/brightness", &st))
132 noled = 1;
133
134 if (daemon(0, 0) != 0) {
135 perror("daemon");
136 return EXIT_FAILURE;
137 }
138
139 openlog(app_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
140
141 param.sched_priority = sched_get_priority_max(SCHED_FIFO);
142 sched_setscheduler(0, SCHED_FIFO, ¶m);
143 mlockall(MCL_CURRENT|MCL_FUTURE);
144
145 signal(SIGALRM, ignore_me);
146
147 for (;;) {
148 unsigned char count;
149
150 ret = read(fd, &count, sizeof(count));
151 alarm(0);
152 if ((ret == -1) && (errno == EINTR)) {
153 /* Alarm expired, time to unpark the heads */
154 continue;
155 }
156
157 if (ret != sizeof(count)) {
158 perror("read");
159 break;
160 }
161
162 protect(21);
163 set_led(1);
164 if (1 || on_ac() || lid_open())
165 alarm(2);
166 else
167 alarm(20);
168 }
169
170 closelog();
171 close(fd);
172 return EXIT_SUCCESS;
173 }
174