Use std::filesystem for input event devices scan.

Use std::filesystem directory iterator to scan event devices in EventHub.

Bug: 160010896
Test: atest inputflinger_tests, atest EventHubTest
Change-Id: Ib5658e96783b8a1099fe0a2cb6dda51703045c84
Merged-In: Ib5658e96783b8a1099fe0a2cb6dda51703045c84

4 files changed, 43 insertions, 61 deletions

diff --git a/services/inputflinger/reader/Android.bp b/services/inputflinger/reader/Android.bp
index dadbd0ea83..9846640dcb 100644
--- a/services/inputflinger/reader/Android.bp
+++ b/services/inputflinger/reader/Android.bp
@@ -90,4 +90,7 @@ cc_library_shared {
     export_header_lib_headers: [
         "libinputreader_headers",
     ],
+    static_libs: [
+        "libc++fs"
+    ],
 }
diff --git a/services/inputflinger/reader/EventHub.cpp b/services/inputflinger/reader/EventHub.cpp
index a1514af668..0ff7e95149 100644
--- a/services/inputflinger/reader/EventHub.cpp
+++ b/services/inputflinger/reader/EventHub.cpp
@@ -34,20 +34,20 @@
 #define LOG_TAG "EventHub"
 
 // #define LOG_NDEBUG 0
-
-#include "EventHub.h"
-
 #include <android-base/stringprintf.h>
 #include <cutils/properties.h>
+#include <input/KeyCharacterMap.h>
+#include <input/KeyLayoutMap.h>
+#include <input/VirtualKeyMap.h>
 #include <openssl/sha.h>
 #include <utils/Errors.h>
 #include <utils/Log.h>
 #include <utils/Timers.h>
 #include <utils/threads.h>
 
-#include <input/KeyCharacterMap.h>
-#include <input/KeyLayoutMap.h>
-#include <input/VirtualKeyMap.h>
+#include <filesystem>
+
+#include "EventHub.h"
 
 /* this macro is used to tell if "bit" is set in "array"
  * it selects a byte from the array, and does a boolean AND
@@ -94,8 +94,8 @@ static std::string sha1(const std::string& in) {
 /**
  * Return true if name matches "v4l-touch*"
  */
-static bool isV4lTouchNode(const char* name) {
-    return strstr(name, "v4l-touch") == name;
+static bool isV4lTouchNode(std::string name) {
+    return name.find("v4l-touch") != std::string::npos;
 }
 
 /**
@@ -810,7 +810,7 @@ EventHub::Device* EventHub::getDeviceLocked(int32_t deviceId) const {
     return index >= 0 ? mDevices.valueAt(index) : NULL;
 }
 
-EventHub::Device* EventHub::getDeviceByPathLocked(const char* devicePath) const {
+EventHub::Device* EventHub::getDeviceByPathLocked(const std::string& devicePath) const {
     for (size_t i = 0; i < mDevices.size(); i++) {
         Device* device = mDevices.valueAt(i);
         if (device->path == devicePath) {
@@ -1215,14 +1215,14 @@ void EventHub::unregisterVideoDeviceFromEpollLocked(const TouchVideoDevice& vide
     }
 }
 
-status_t EventHub::openDeviceLocked(const char* devicePath) {
+status_t EventHub::openDeviceLocked(const std::string& devicePath) {
     char buffer[80];
 
-    ALOGV("Opening device: %s", devicePath);
+    ALOGV("Opening device: %s", devicePath.c_str());
 
-    int fd = open(devicePath, O_RDWR | O_CLOEXEC | O_NONBLOCK);
+    int fd = open(devicePath.c_str(), O_RDWR | O_CLOEXEC | O_NONBLOCK);
     if (fd < 0) {
-        ALOGE("could not open %s, %s\n", devicePath, strerror(errno));
+        ALOGE("could not open %s, %s\n", devicePath.c_str(), strerror(errno));
         return -1;
     }
 
@@ -1230,7 +1230,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
 
     // Get device name.
     if (ioctl(fd, EVIOCGNAME(sizeof(buffer) - 1), &buffer) < 1) {
-        ALOGE("Could not get device name for %s: %s", devicePath, strerror(errno));
+        ALOGE("Could not get device name for %s: %s", devicePath.c_str(), strerror(errno));
     } else {
         buffer[sizeof(buffer) - 1] = '\0';
         identifier.name = buffer;
@@ -1240,7 +1240,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
     for (size_t i = 0; i < mExcludedDevices.size(); i++) {
         const std::string& item = mExcludedDevices[i];
         if (identifier.name == item) {
-            ALOGI("ignoring event id %s driver %s\n", devicePath, item.c_str());
+            ALOGI("ignoring event id %s driver %s\n", devicePath.c_str(), item.c_str());
             close(fd);
             return -1;
         }
@@ -1249,7 +1249,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
     // Get device driver version.
     int driverVersion;
     if (ioctl(fd, EVIOCGVERSION, &driverVersion)) {
-        ALOGE("could not get driver version for %s, %s\n", devicePath, strerror(errno));
+        ALOGE("could not get driver version for %s, %s\n", devicePath.c_str(), strerror(errno));
         close(fd);
         return -1;
     }
@@ -1257,7 +1257,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
     // Get device identifier.
     struct input_id inputId;
     if (ioctl(fd, EVIOCGID, &inputId)) {
-        ALOGE("could not get device input id for %s, %s\n", devicePath, strerror(errno));
+        ALOGE("could not get device input id for %s, %s\n", devicePath.c_str(), strerror(errno));
         close(fd);
         return -1;
     }
@@ -1289,7 +1289,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
     int32_t deviceId = mNextDeviceId++;
     Device* device = new Device(fd, deviceId, devicePath, identifier);
 
-    ALOGV("add device %d: %s\n", deviceId, devicePath);
+    ALOGV("add device %d: %s\n", deviceId, devicePath.c_str());
     ALOGV("  bus:        %04x\n"
           "  vendor      %04x\n"
           "  product     %04x\n"
@@ -1446,7 +1446,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
 
     // If the device isn't recognized as something we handle, don't monitor it.
     if (device->classes == 0) {
-        ALOGV("Dropping device: id=%d, path='%s', name='%s'", deviceId, devicePath,
+        ALOGV("Dropping device: id=%d, path='%s', name='%s'", deviceId, devicePath.c_str(),
               device->identifier.name.c_str());
         delete device;
         return -1;
@@ -1492,7 +1492,7 @@ status_t EventHub::openDeviceLocked(const char* devicePath) {
 
     ALOGI("New device: id=%d, fd=%d, path='%s', name='%s', classes=0x%x, "
           "configuration='%s', keyLayout='%s', keyCharacterMap='%s', builtinKeyboard=%s, ",
-          deviceId, fd, devicePath, device->identifier.name.c_str(), device->classes,
+          deviceId, fd, devicePath.c_str(), device->identifier.name.c_str(), device->classes,
           device->configurationFile.c_str(), device->keyMap.keyLayoutFile.c_str(),
           device->keyMap.keyCharacterMapFile.c_str(), toString(mBuiltInKeyboardId == deviceId));
 
@@ -1724,13 +1724,13 @@ status_t EventHub::mapLed(Device* device, int32_t led, int32_t* outScanCode) con
     return NAME_NOT_FOUND;
 }
 
-void EventHub::closeDeviceByPathLocked(const char* devicePath) {
+void EventHub::closeDeviceByPathLocked(const std::string& devicePath) {
     Device* device = getDeviceByPathLocked(devicePath);
     if (device) {
         closeDeviceLocked(device);
         return;
     }
-    ALOGV("Remove device: %s not found, device may already have been removed.", devicePath);
+    ALOGV("Remove device: %s not found, device may already have been removed.", devicePath.c_str());
 }
 
 /**
@@ -1835,16 +1835,16 @@ status_t EventHub::readNotifyLocked() {
         event = (struct inotify_event*)(event_buf + event_pos);
         if (event->len) {
             if (event->wd == mInputWd) {
-                std::string filename = StringPrintf("%s/%s", DEVICE_PATH, event->name);
+                std::string filename = std::string(DEVICE_PATH) + "/" + event->name;
                 if (event->mask & IN_CREATE) {
-                    openDeviceLocked(filename.c_str());
+                    openDeviceLocked(filename);
                 } else {
                     ALOGI("Removing device '%s' due to inotify event\n", filename.c_str());
-                    closeDeviceByPathLocked(filename.c_str());
+                    closeDeviceByPathLocked(filename);
                 }
             } else if (event->wd == mVideoWd) {
                 if (isV4lTouchNode(event->name)) {
-                    std::string filename = StringPrintf("%s/%s", VIDEO_DEVICE_PATH, event->name);
+                    std::string filename = std::string(VIDEO_DEVICE_PATH) + "/" + event->name;
                     if (event->mask & IN_CREATE) {
                         openVideoDeviceLocked(filename);
                     } else {
@@ -1863,24 +1863,10 @@ status_t EventHub::readNotifyLocked() {
     return 0;
 }
 
-status_t EventHub::scanDirLocked(const char* dirname) {
-    char devname[PATH_MAX];
-    char* filename;
-    DIR* dir;
-    struct dirent* de;
-    dir = opendir(dirname);
-    if (dir == nullptr) return -1;
-    strcpy(devname, dirname);
-    filename = devname + strlen(devname);
-    *filename++ = '/';
-    while ((de = readdir(dir))) {
-        if (de->d_name[0] == '.' &&
-            (de->d_name[1] == '\0' || (de->d_name[1] == '.' && de->d_name[2] == '\0')))
-            continue;
-        strcpy(filename, de->d_name);
-        openDeviceLocked(devname);
+status_t EventHub::scanDirLocked(const std::string& dirname) {
+    for (const auto& entry : std::filesystem::directory_iterator(dirname)) {
+        openDeviceLocked(entry.path());
     }
-    closedir(dir);
     return 0;
 }
 
@@ -1888,22 +1874,12 @@ status_t EventHub::scanDirLocked(const char* dirname) {
  * Look for all dirname/v4l-touch* devices, and open them.
  */
 status_t EventHub::scanVideoDirLocked(const std::string& dirname) {
-    DIR* dir;
-    struct dirent* de;
-    dir = opendir(dirname.c_str());
-    if (!dir) {
-        ALOGE("Could not open video directory %s", dirname.c_str());
-        return BAD_VALUE;
-    }
-
-    while ((de = readdir(dir))) {
-        const char* name = de->d_name;
-        if (isV4lTouchNode(name)) {
-            ALOGI("Found touch video device %s", name);
-            openVideoDeviceLocked(dirname + "/" + name);
+    for (const auto& entry : std::filesystem::directory_iterator(dirname)) {
+        if (isV4lTouchNode(entry.path())) {
+            ALOGI("Found touch video device %s", entry.path().c_str());
+            openVideoDeviceLocked(entry.path());
         }
     }
-    closedir(dir);
     return OK;
 }
 
diff --git a/services/inputflinger/reader/include/EventHub.h b/services/inputflinger/reader/include/EventHub.h
index f5451d7fef..d0a6a3fb47 100644
--- a/services/inputflinger/reader/include/EventHub.h
+++ b/services/inputflinger/reader/include/EventHub.h
@@ -373,13 +373,13 @@ private:
         }
     };
 
-    status_t openDeviceLocked(const char* devicePath);
+    status_t openDeviceLocked(const std::string& devicePath);
     void openVideoDeviceLocked(const std::string& devicePath);
     void createVirtualKeyboardLocked();
     void addDeviceLocked(Device* device);
     void assignDescriptorLocked(InputDeviceIdentifier& identifier);
 
-    void closeDeviceByPathLocked(const char* devicePath);
+    void closeDeviceByPathLocked(const std::string& devicePath);
     void closeVideoDeviceByPathLocked(const std::string& devicePath);
     void closeDeviceLocked(Device* device);
     void closeAllDevicesLocked();
@@ -396,14 +396,14 @@ private:
     status_t unregisterDeviceFromEpollLocked(Device* device);
     void unregisterVideoDeviceFromEpollLocked(const TouchVideoDevice& videoDevice);
 
-    status_t scanDirLocked(const char* dirname);
+    status_t scanDirLocked(const std::string& dirname);
     status_t scanVideoDirLocked(const std::string& dirname);
     void scanDevicesLocked();
     status_t readNotifyLocked();
 
     Device* getDeviceByDescriptorLocked(const std::string& descriptor) const;
     Device* getDeviceLocked(int32_t deviceId) const;
-    Device* getDeviceByPathLocked(const char* devicePath) const;
+    Device* getDeviceByPathLocked(const std::string& devicePath) const;
     /**
      * Look through all available fd's (both for input devices and for video devices),
      * and return the device pointer.
diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 86ed60dbcc..24a27cf9b3 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -46,5 +46,8 @@ cc_test {
         "InputReader_test.cpp",
         "UinputDevice.cpp",
     ],
+    static_libs: [
+        "libc++fs"
+    ],
     require_root: true,
 }