ts_uinput: input device check

woaidr · Jan 17, 2017 · c5f26c0 · c5f26c0
1 parent 71f1511
commit c5f26c0
Showing 1 changed file with 21 additions and 0 deletions.
diff --git a/tools/ts_uinput.c b/tools/ts_uinput.c
@@ -52,6 +52,15 @@
 #define UI_GET_SYSNAME(len)     _IOC(_IOC_READ, UINPUT_IOCTL_BASE, 44, len)
 #endif
 
+#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
+#define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
+#define BITS_PER_BYTE           8
+#define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
+#ifndef ABS_CNT
+# define ABS_CNT (ABS_MAX+1)
+#endif
+
 /* TODO user-option: read non-MT events off fd_input and send them in a seperate sync-frame */
 
 struct data_t {
@@ -447,6 +456,7 @@ static void cleanup(struct data_t *data)
 
 int main(int argc, char **argv)
 {
+	long absbit[BITS_TO_LONGS(ABS_CNT)];
 	struct data_t data = {
 		.fd_uinput = 0,
 		.fd_input = 0,
@@ -573,6 +583,17 @@ int main(int argc, char **argv)
 		perror("open");
 		goto out;
 	}
+
+	if ((ioctl(data.fd_input, EVIOCGBIT(EV_ABS, sizeof(absbit)), absbit)) < 0 ||
+	    !(absbit[BIT_WORD(ABS_X)] & BIT_MASK(ABS_X)) ||
+	    !(absbit[BIT_WORD(ABS_Y)] & BIT_MASK(ABS_Y))) {
+		if (!(absbit[BIT_WORD(ABS_MT_POSITION_X)] & BIT_MASK(ABS_MT_POSITION_X)) ||
+		    !(absbit[BIT_WORD(ABS_MT_POSITION_Y)] & BIT_MASK(ABS_MT_POSITION_Y))) {
+			fprintf(stderr, "ts_uinput: device is not a touchscreen (must support ABS_X/Y or ABS_MT_POSITION_X/Y events)\n");
+			goto out;
+		}
+        }
+
 	data.ts = ts_open(data.input_name, 0 /* blocking */);
 	if (!data.ts) {
 		perror("ts_open");