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1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <stdint.h>
5 #include <dirent.h>
6 #include <fcntl.h>
7 #include <sys/ioctl.h>
8 #include <sys/inotify.h>
9 #include <sys/limits.h>
10 #include <sys/poll.h>
11 #include <linux/input.h>
12 #include <errno.h>
13 #include <cutils/log.h>
14 
15 static struct pollfd *ufds;
16 static char **device_names;
17 static int nfds;
18 
open_device(const char * device)19 static int open_device(const char *device)
20 {
21     int version;
22     int fd;
23     struct pollfd *new_ufds;
24     char **new_device_names;
25     char name[80];
26     char location[80];
27     char idstr[80];
28     struct input_id id;
29 
30     fd = open(device, O_RDWR);
31     if(fd < 0) {
32         return -1;
33     }
34 
35     if(ioctl(fd, EVIOCGVERSION, &version)) {
36         return -1;
37     }
38     if(ioctl(fd, EVIOCGID, &id)) {
39         return -1;
40     }
41     name[sizeof(name) - 1] = '\0';
42     location[sizeof(location) - 1] = '\0';
43     idstr[sizeof(idstr) - 1] = '\0';
44     if(ioctl(fd, EVIOCGNAME(sizeof(name) - 1), &name) < 1) {
45         //fprintf(stderr, "could not get device name for %s, %s\n", device, strerror(errno));
46         name[0] = '\0';
47     }
48     if(ioctl(fd, EVIOCGPHYS(sizeof(location) - 1), &location) < 1) {
49         //fprintf(stderr, "could not get location for %s, %s\n", device, strerror(errno));
50         location[0] = '\0';
51     }
52     if(ioctl(fd, EVIOCGUNIQ(sizeof(idstr) - 1), &idstr) < 1) {
53         //fprintf(stderr, "could not get idstring for %s, %s\n", device, strerror(errno));
54         idstr[0] = '\0';
55     }
56 
57     new_ufds = realloc(ufds, sizeof(ufds[0]) * (nfds + 1));
58     if(new_ufds == NULL) {
59         fprintf(stderr, "out of memory\n");
60         return -1;
61     }
62     ufds = new_ufds;
63     new_device_names = realloc(device_names, sizeof(device_names[0]) * (nfds + 1));
64     if(new_device_names == NULL) {
65         fprintf(stderr, "out of memory\n");
66         return -1;
67     }
68     device_names = new_device_names;
69     ufds[nfds].fd = fd;
70     ufds[nfds].events = POLLIN;
71     device_names[nfds] = strdup(device);
72     nfds++;
73 
74     return 0;
75 }
76 
close_device(const char * device)77 int close_device(const char *device)
78 {
79     int i;
80     for(i = 1; i < nfds; i++) {
81         if(strcmp(device_names[i], device) == 0) {
82             int count = nfds - i - 1;
83             free(device_names[i]);
84             memmove(device_names + i, device_names + i + 1, sizeof(device_names[0]) * count);
85             memmove(ufds + i, ufds + i + 1, sizeof(ufds[0]) * count);
86             nfds--;
87             return 0;
88         }
89     }
90     return -1;
91 }
92 
read_notify(const char * dirname,int nfd)93 static int read_notify(const char *dirname, int nfd)
94 {
95     int res;
96     char devname[PATH_MAX];
97     char *filename;
98     char event_buf[512];
99     int event_size;
100     int event_pos = 0;
101     struct inotify_event *event;
102 
103     res = read(nfd, event_buf, sizeof(event_buf));
104     if(res < (int)sizeof(*event)) {
105         if(errno == EINTR)
106             return 0;
107         fprintf(stderr, "could not get event, %s\n", strerror(errno));
108         return 1;
109     }
110     //printf("got %d bytes of event information\n", res);
111 
112     strcpy(devname, dirname);
113     filename = devname + strlen(devname);
114     *filename++ = '/';
115 
116     while(res >= (int)sizeof(*event)) {
117         event = (struct inotify_event *)(event_buf + event_pos);
118         //printf("%d: %08x \"%s\"\n", event->wd, event->mask, event->len ? event->name : "");
119         if(event->len) {
120             strcpy(filename, event->name);
121             if(event->mask & IN_CREATE) {
122                 open_device(devname);
123             }
124             else {
125                 close_device(devname);
126             }
127         }
128         event_size = sizeof(*event) + event->len;
129         res -= event_size;
130         event_pos += event_size;
131     }
132     return 0;
133 }
134 
scan_dir(const char * dirname)135 static int scan_dir(const char *dirname)
136 {
137     char devname[PATH_MAX];
138     char *filename;
139     DIR *dir;
140     struct dirent *de;
141     dir = opendir(dirname);
142     if(dir == NULL)
143         return -1;
144     strcpy(devname, dirname);
145     filename = devname + strlen(devname);
146     *filename++ = '/';
147     while((de = readdir(dir))) {
148         if(de->d_name[0] == '.' &&
149            (de->d_name[1] == '\0' ||
150             (de->d_name[1] == '.' && de->d_name[2] == '\0')))
151             continue;
152         strcpy(filename, de->d_name);
153         open_device(devname);
154     }
155     closedir(dir);
156     return 0;
157 }
158 
init_getevent()159 int init_getevent()
160 {
161     int res;
162     const char *device_path = "/dev/input";
163 
164     nfds = 1;
165     ufds = calloc(1, sizeof(ufds[0]));
166     ufds[0].fd = inotify_init();
167     ufds[0].events = POLLIN;
168 
169 	res = inotify_add_watch(ufds[0].fd, device_path, IN_DELETE | IN_CREATE);
170     if(res < 0) {
171         return 1;
172     }
173     res = scan_dir(device_path);
174     if(res < 0) {
175         return 1;
176     }
177     return 0;
178 }
179 
uninit_getevent()180 void uninit_getevent()
181 {
182     int i;
183     for(i = 0; i < nfds; i++) {
184         close(ufds[i].fd);
185     }
186     free(ufds);
187     ufds = 0;
188     nfds = 0;
189 }
190 
get_event(struct input_event * event,int timeout)191 int get_event(struct input_event* event, int timeout)
192 {
193     int res;
194     int i;
195     int pollres;
196     const char *device_path = "/dev/input";
197     while(1) {
198         pollres = poll(ufds, nfds, timeout);
199         if (pollres == 0) {
200             return 1;
201         }
202         if(ufds[0].revents & POLLIN) {
203             read_notify(device_path, ufds[0].fd);
204         }
205         for(i = 1; i < nfds; i++) {
206             if(ufds[i].revents) {
207                 if(ufds[i].revents & POLLIN) {
208                     res = read(ufds[i].fd, event, sizeof(*event));
209                     if(res < (int)sizeof(event)) {
210                         fprintf(stderr, "could not get event\n");
211                         return -1;
212                     }
213                     return 0;
214                 }
215             }
216         }
217     }
218     return 0;
219 }
220