MTP: Better handling of stat

Do some error checking of lstat calls and better handle those
errors.
Use lstat instead of dirent to check if an item is a directory
because dirent does not return the correct item type when using
exfat-fuse.

Change-Id: I0d008aff55a0e0b4fbeae24cf8d0c04453b7b77e
diff --git a/mtp/MtpServer.cpp b/mtp/MtpServer.cpp
index 5dec580..c044cad 100755
--- a/mtp/MtpServer.cpp
+++ b/mtp/MtpServer.cpp
@@ -1132,7 +1132,12 @@
 		strcpy(fileSpot, name);
 
 		int type = entry->d_type;
-		if (entry->d_type == DT_DIR) {
+		struct stat st;
+		if (lstat(pathbuf, &st)) {
+			MTPE("Failed to lstat '%s'\n", pathbuf);
+			continue;
+		}
+		if (st.st_mode & S_IFDIR) {
 			deleteRecursive(pathbuf);
 			rmdir(pathbuf);
 		} else {
diff --git a/mtp/MtpStorage.cpp b/mtp/MtpStorage.cpp
index 7531ac4..57c8774 100755
--- a/mtp/MtpStorage.cpp
+++ b/mtp/MtpStorage.cpp
@@ -185,7 +185,7 @@
 
 int MtpStorage::getObjectInfo(MtpObjectHandle handle, MtpObjectInfo& info) {
 	struct stat st;
-	uint64_t size;
+	uint64_t size = 0;
 	MTPD("MtpStorage::getObjectInfo handle: %d\n", handle);
 	for (iter i = mtpmap.begin(); i != mtpmap.end(); i++) {
 		Node* node = i->second->findNode(handle, i->second->Root());
@@ -196,8 +196,8 @@
 				MTPD("info.mStorageID: %d\n", info.mStorageID);
 				info.mParent = node->getMtpParentId();
 				MTPD("mParent: %d\n", info.mParent);
-				lstat(node->getPath().c_str(), &st);
-				size = st.st_size;
+				if (lstat(node->getPath().c_str(), &st) == 0)
+					size = st.st_size;
 				MTPD("size is: %llu\n", size);
 				info.mCompressedSize = size;//(size > 0xFFFFFFFFLL ? 0xFFFFFFFF : size);
 				info.mDateModified = st.st_mtime;
@@ -283,8 +283,10 @@
 		node = i->second->findNode(handle, i->second->Root());
 		MTPD("node returned: %d\n", node);
 		if (node != NULL) {
-			lstat(node->getPath().c_str(), &st);
-			outFileLength = st.st_size;
+			if (lstat(node->getPath().c_str(), &st) == 0)
+				outFileLength = st.st_size;
+			else
+				outFileLength = 0;
 			outFilePath = strdup(node->getPath().c_str());
 			MTPD("outFilePath: %s\n", node->getPath().c_str());
 			goto end;
@@ -312,11 +314,17 @@
 		closedir(d);
 	}
 	while ((de = readdir(d)) != NULL) {
-		if (de->d_type == DT_DIR && strcmp(de->d_name, ".") == 0)
+		// Because exfat-fuse causes issues with dirent, we will use stat
+		// for some things that dirent should be able to do
+		item = path + "/" + de->d_name;
+		if (lstat(item.c_str(), &st)) {
+			MTPE("Error running lstat on '%s'\n", item.c_str());
+			return -1;
+		}
+		if ((st.st_mode & S_IFDIR) && strcmp(de->d_name, ".") == 0)
 			continue;
-		if (de->d_type == DT_DIR && strcmp(de->d_name, "..") != 0) {
+		if ((st.st_mode & S_IFDIR) && strcmp(de->d_name, "..") != 0) {
 			// Handle dirs
-			item = path + "/" + de->d_name;
 			MTPD("dir: %s\n", item.c_str());
 			mtpParentList.push_back(item);
 			parent = item.substr(0, item.find_last_of('/'));
@@ -540,9 +548,9 @@
 			Node *node = i->second->findNode(handle, i->second->Root());
 			if (node != NULL) {
 				struct stat st;
-				uint64_t size;
-				lstat(node->getPath().c_str(), &st);
-				size = st.st_size;
+				uint64_t size = 0;
+				if (lstat(node->getPath().c_str(), &st) == 0)
+					size = st.st_size;
 				propertyCodes.push_back(MTP_PROPERTY_OBJECT_SIZE);
 				longValues.push_back(size);
 				valueStrs.push_back("");
@@ -705,14 +713,18 @@
 	}
 
 	while ((de = readdir(d)) != NULL) {
-		if (de->d_type != DT_DIR || strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
-			continue;
 		inotifypath = path + "/" + de->d_name;
+		if (lstat(inotifypath.c_str(), &st)) {
+			MTPE("Error using lstat on '%s'\n", inotifypath.c_str());
+			return -1;
+		}
+		if (!(st.st_mode & S_IFDIR) || strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
+			continue;
 		if (addInotifyDirs(inotifypath)) {
 			closedir(d);
 			return -1;
 		}
-		inotify_wd = inotify_add_watch(inotify_fd, inotifypath.c_str(), IN_CREATE | IN_DELETE);
+		inotify_wd = inotify_add_watch(inotify_fd, inotifypath.c_str(), WATCH_FLAGS);
 		inotifymap[inotify_wd] = inotifypath;
 		MTPD("added inotify dir: '%s'\n", inotifypath.c_str());
 	}
@@ -868,8 +880,9 @@
 						if (node != NULL) {
 							uint64_t orig_size = node->getIntProperty(MTP_PROPERTY_OBJECT_SIZE);
 							struct stat st;
-							lstat(item.c_str(), &st);
-							uint64_t new_size = (uint64_t)st.st_size;
+							uint64_t new_size = 0;
+							if (lstat(item.c_str(), &st) == 0)
+								new_size = (uint64_t)st.st_size;
 							if (orig_size != new_size) {
 								MTPD("size changed from %llu to %llu on mtpid: %i\n", orig_size, new_size, node->Mtpid());
 								node->updateProperty(MTP_PROPERTY_OBJECT_SIZE, new_size, "", MTP_TYPE_UINT64);
diff --git a/mtp/node.cpp b/mtp/node.cpp
index 79936c4..1a09c85 100755
--- a/mtp/node.cpp
+++ b/mtp/node.cpp
@@ -103,24 +103,27 @@
 	struct stat st;
 	int mFormat = 0;
 	uint64_t puid;
+	off_t file_size = 0;
+	std::string mtimeStr = "00101T000000";
+	std::string atimeStr = "00101T000000";
 
 	std::string mtpidStr = static_cast<std::ostringstream*>( &(std::ostringstream() << mtpid) )->str();
 	std::string storageIDStr = static_cast<std::ostringstream*>( &(std::ostringstream() << storageID) )->str();
 	std::string puidStr = storageIDStr + mtpidStr;
 	if ( ! (std::istringstream(puidStr) >> puid) ) puid = 0;
-	stat(getPath().c_str(), &st);
-	std::string mtimeStr = static_cast<std::ostringstream*>( &(std::ostringstream() << st.st_mtime) )->str();
-	std::string atimeStr = static_cast<std::ostringstream*>( &(std::ostringstream() << st.st_atime) )->str();
-	if (S_ISDIR(st.st_mode)) {
-		mFormat = MTP_FORMAT_ASSOCIATION; // folder
+	mFormat = MTP_FORMAT_UNDEFINED;   // file
+	if (lstat(getPath().c_str(), &st) == 0) {
+		file_size = st.st_size;
+		if (S_ISDIR(st.st_mode))
+			mFormat = MTP_FORMAT_ASSOCIATION; // folder
+		mtimeStr = static_cast<std::ostringstream*>( &(std::ostringstream() << st.st_mtime) )->str();
+		atimeStr = static_cast<std::ostringstream*>( &(std::ostringstream() << st.st_atime) )->str();
 	}
-	else {
-		mFormat = MTP_FORMAT_UNDEFINED;   // file
-	}
+
 	addProperty(MTP_PROPERTY_STORAGE_ID, storageID, "", MTP_TYPE_UINT32);
 	addProperty(MTP_PROPERTY_OBJECT_FORMAT, mFormat, "", MTP_TYPE_UINT16);
 	addProperty(MTP_PROPERTY_PROTECTION_STATUS, 0, "", MTP_TYPE_UINT16);
-	addProperty(MTP_PROPERTY_OBJECT_SIZE, st.st_size, "", MTP_TYPE_UINT64);
+	addProperty(MTP_PROPERTY_OBJECT_SIZE, file_size, "", MTP_TYPE_UINT64);
 	addProperty(MTP_PROPERTY_OBJECT_FILE_NAME, 0, basename(getPath().c_str()), MTP_TYPE_STR);
 	MTPD("mtpid: %i, filename: '%s', parent object: %i\n", mtpid, basename(getPath().c_str()), parent_object);
 	addProperty(MTP_PROPERTY_DATE_MODIFIED, 0, mtimeStr, MTP_TYPE_STR);