MTP: Add fuzzer dict & corpus loader

Moved and modified from libFuzzer/mtp_fuzzer

Bug: 140904260
Test: mtp_fuzzer -dict=mtp_fuzzer.dict corpus
Change-Id: I8e063c9b4eaa2b834fc8759e43865d81cea3d8c5
diff --git a/media/mtp/tests/MtpFuzzer/MtpMockHandle.h b/media/mtp/tests/MtpFuzzer/MtpMockHandle.h
new file mode 100644
index 0000000..111485c
--- /dev/null
+++ b/media/mtp/tests/MtpFuzzer/MtpMockHandle.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _MTP_MOCK_HANDLE_H
+#define _MTP_MOCK_HANDLE_H
+
+#include <vector>
+
+typedef std::vector<uint8_t> packet_t;
+
+namespace android {
+class MtpMockHandle : public IMtpHandle {
+private:
+    size_t mPacketNumber;
+    size_t mPacketOffset;
+    std::vector<packet_t> mPackets;
+
+public:
+    MtpMockHandle() : mPacketNumber(0), mPacketOffset(0) {}
+
+    void add_packet(packet_t pkt) { mPackets.push_back(pkt); }
+
+    // Return number of bytes read/written, or -1 and errno is set
+    int read(void *data, size_t len) {
+        if (mPacketNumber >= mPackets.size()) {
+            return 0;
+        } else {
+            int readAmt = 0;
+            packet_t pkt = mPackets[mPacketNumber];
+
+            ALOGD("%s: sz %zu, pkt %zu+%zu/%zu\n", __func__, len, mPacketNumber, mPacketOffset,
+                  pkt.size());
+
+            // packet is bigger than what the caller can handle,
+            if (pkt.size() > len) {
+                memcpy(data, pkt.data() + mPacketOffset, len);
+
+                mPacketOffset += len;
+                readAmt = len;
+                // packet is equal or smaller than the caller buffer
+            } else {
+                memcpy(data, pkt.data() + mPacketOffset, pkt.size());
+
+                mPacketNumber++;
+                mPacketOffset = 0;
+                readAmt = pkt.size();
+            }
+
+            return readAmt;
+        }
+    }
+    int write(const void *data, size_t len) {
+        ALOGD("MockHandle %s: len=%zu\n", __func__, len);
+        // fake the write
+        return len;
+    }
+
+    // Return 0 if send/receive is successful, or -1 and errno is set
+    int receiveFile(mtp_file_range mfr, bool zero_packet) {
+        ALOGD("MockHandle %s\n", __func__);
+        return 0;
+    }
+    int sendFile(mtp_file_range mfr) {
+        ALOGD("MockHandle %s\n", __func__);
+        return 0;
+    }
+    int sendEvent(mtp_event me) {
+        ALOGD("MockHandle %s: len=%zu\n", __func__, me.length);
+        return 0;
+    }
+
+    // Return 0 if operation is successful, or -1 else
+    int start(bool ptp) { return 0; }
+
+    void close() {}
+
+    virtual ~MtpMockHandle() {}
+};
+}; // namespace android
+
+#endif // _MTP_MOCK_HANDLE_H