From d3a6d69e9b0d765f4b0d9f9b108cb90c72417947 Mon Sep 17 00:00:00 2001
From: Jingkui Wang <jkwang@google.com>
Date: Wed, 6 Sep 2017 10:13:29 -0700
Subject: [PATCH] Enable safe mode for evtest

This patch enables --safe for evtest. When evtest is called with --safe,
all the sensitive event info will be hidden.
---
 evtest.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 55 insertions(+), 2 deletions(-)

diff --git a/evtest.c b/evtest.c
index 2cf25f0..fa9df4a 100644
--- a/evtest.c
+++ b/evtest.c
@@ -98,6 +98,7 @@ static const struct query_mode {
 };
 
 static int grab_flag = 0;
+static int safe_flag = 0;
 static volatile sig_atomic_t stop = 0;
 
 static void interrupt_handler(int sig)
@@ -595,6 +596,7 @@ static const char * const * const names[EV_MAX + 1] = {
 	[EV_FF] = force,			[EV_FF_STATUS] = forcestatus,
 };
 
+static int cached_absinfo[ABS_MAX][6] = {0};
 /**
  * Convert a string to a specific key/snd/led/sw code. The string can either
  * be the name of the key in question (e.g. "SW_DOCK") or the numerical
@@ -716,6 +718,10 @@ static int usage(void)
 	printf("   %s --query /dev/input/eventX <type> <value>\n",
 		program_invocation_short_name);
 
+	printf("\n");
+	printf(" Safe mode:\n");
+	printf("   %s --safe\n", program_invocation_short_name);
+	printf("     --safe  hide sensitive event information\n");
 	printf("\n");
 	printf("<type> is one of: EV_KEY, EV_SW, EV_LED, EV_SND\n");
 	printf("<value> can either be a numerical value, or the textual name of the\n");
@@ -733,7 +739,7 @@ static int usage(void)
  */
 static void print_absdata(int fd, int axis)
 {
-	int abs[6] = {0};
+	int* abs = cached_absinfo[axis];
 	int k;
 
 	ioctl(fd, EVIOCGABS(axis), abs);
@@ -823,6 +829,47 @@ static int print_device_info(int fd)
 	return 0;
 }
 
+/**
+ * Print event safely and do not print any sensitive infomation.
+ *
+ * @param ev The event to print.
+ */
+static void safe_print_event(struct input_event* ev) {
+	const char* type_str = events[ev->type] ? events[ev->type] : "?";
+	const char* code_str =
+		names[ev->type] ? (names[ev->type][ev->code] ?
+				  names[ev->type][ev->code] : "?") : "?";
+	printf("type %d (%s)", ev->type, type_str);
+	switch (ev->type) {
+		case EV_KEY:
+			printf(", code *, value %d\n", ev->value);
+			break;
+		case EV_REL:
+			printf(", code %d (%s)\n", ev->code, code_str);
+			break;
+		case EV_ABS:
+			printf(", code %d (%s), ", ev->code, code_str);
+			if (ev->value == cached_absinfo[ev->code][1])
+				printf("%s\n", "value = abs_min");
+			else if (ev->value == cached_absinfo[ev->code][2])
+				printf("%s\n", "value = abs_max");
+			else if (ev->value > cached_absinfo[ev->code][2] &&
+				 ev->value < cached_absinfo[ev->code][1])
+				printf("%s\n", "value out of range (min, max)");
+			else
+				printf("%s\n", "value in range (min, max)");
+			break;
+		case EV_MSC:
+			if (ev->code == MSC_TIMESTAMP)
+				printf(", code %d (%s), value %s\n", ev->code,
+				       code_str, ev->value ? "non-zero" : "0");
+			else
+				printf(", code %d (%s)\n", ev->code, code_str);
+		default:
+			break;
+	}
+}
+
 /**
  * Print device events as they come in.
  *
@@ -851,13 +898,18 @@ static int print_events(int fd)
 		}
 
 		for (i = 0; i < rd / sizeof(struct input_event); i++) {
-			printf("Event: time %ld.%06ld, ", ev[i].time.tv_sec, ev[i].time.tv_usec);
+			if (safe_flag)
+				printf("Event: time %ld, ", ev[i].time.tv_sec);
+			else
+				printf("Event: time %ld.%06ld, ", ev[i].time.tv_sec, ev[i].time.tv_usec);
 
 			if (ev[i].type == EV_SYN) {
 				if (ev[i].code == SYN_MT_REPORT)
 					printf("++++++++++++++ %s ++++++++++++\n", syns[ev[i].code]);
 				else
 					printf("-------------- %s ------------\n", syns[ev[i].code]);
+			} else if (safe_flag) {
+				safe_print_event(&ev[i]);
 			} else {
 				printf("type %d (%s), code %d (%s), ",
 					ev[i].type,
@@ -1034,6 +1086,7 @@ static int do_query(const char *device, const char *event_type, const char *keyn
 static const struct option long_options[] = {
 	{ "grab", no_argument, &grab_flag, 1 },
 	{ "query", no_argument, NULL, MODE_QUERY },
+	{ "safe", no_argument, &safe_flag, 1 },
 	{ "version", no_argument, NULL, MODE_VERSION },
 	{ 0, },
 };
-- 
2.14.1.581.gf28d330327-goog