Serialize text size on 4 bytes

This will allow to send text having a size greater than 65535 bytes.

app/src/control_msg.c

@@ -20,9 +20,9 @@ write_position(uint8_t *buf, const struct position *position) {
 static size_t
 write_string(const char *utf8, size_t max_len, unsigned char *buf) {
     size_t len = utf8_truncation_index(utf8, max_len);
-    buffer_write16be(buf, (uint16_t) len);
-    memcpy(&buf[2], utf8, len);
-    return 2 + len;
+    buffer_write32be(buf, len);
+    memcpy(&buf[4], utf8, len);
+    return 4 + len;
 }
 
 static uint16_t

app/src/control_msg.h

@@ -13,8 +13,8 @@
 #define CONTROL_MSG_MAX_SIZE 4096
 
 #define CONTROL_MSG_INJECT_TEXT_MAX_LENGTH 300
-// type: 1 byte; paste flag: 1 byte; length: 2 bytes
-#define CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH (CONTROL_MSG_MAX_SIZE - 4)
+// type: 1 byte; paste flag: 1 byte; length: 4 bytes
+#define CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH (CONTROL_MSG_MAX_SIZE - 6)
 
 #define POINTER_ID_MOUSE UINT64_C(-1);
 

app/src/device_msg.c

@@ -9,7 +9,7 @@
 ssize_t
 device_msg_deserialize(const unsigned char *buf, size_t len,
                        struct device_msg *msg) {
-    if (len < 3) {
+    if (len < 5) {
         // at least type + empty string length
         return 0; // not available
     }
@@ -17,8 +17,8 @@ device_msg_deserialize(const unsigned char *buf, size_t len,
     msg->type = buf[0];
     switch (msg->type) {
         case DEVICE_MSG_TYPE_CLIPBOARD: {
-            uint16_t clipboard_len = buffer_read16be(&buf[1]);
-            if (clipboard_len > len - 3) {
+            size_t clipboard_len = buffer_read32be(&buf[1]);
+            if (clipboard_len > len - 5) {
                 return 0; // not available
             }
             char *text = SDL_malloc(clipboard_len + 1);
@@ -27,12 +27,12 @@ device_msg_deserialize(const unsigned char *buf, size_t len,
                 return -1;
             }
             if (clipboard_len) {
-                memcpy(text, &buf[3], clipboard_len);
+                memcpy(text, &buf[5], clipboard_len);
             }
             text[clipboard_len] = '\0';
 
             msg->clipboard.text = text;
-            return 3 + clipboard_len;
+            return 5 + clipboard_len;
         }
         default:
             LOGW("Unknown device message type: %d", (int) msg->type);

app/src/device_msg.h

@@ -8,8 +8,8 @@
 #include "config.h"
 
 #define DEVICE_MSG_MAX_SIZE 4096
-// type: 1 byte; length: 2 bytes
-#define DEVICE_MSG_TEXT_MAX_LENGTH (DEVICE_MSG_MAX_SIZE - 3)
+// type: 1 byte; length: 4 bytes
+#define DEVICE_MSG_TEXT_MAX_LENGTH (DEVICE_MSG_MAX_SIZE - 5)
 
 enum device_msg_type {
     DEVICE_MSG_TYPE_CLIPBOARD,

app/tests/test_control_msg_serialize.c

@@ -36,11 +36,11 @@ static void test_serialize_inject_text(void) {
 
     unsigned char buf[CONTROL_MSG_MAX_SIZE];
     int size = control_msg_serialize(&msg, buf);
-    assert(size == 16);
+    assert(size == 18);
 
     const unsigned char expected[] = {
         CONTROL_MSG_TYPE_INJECT_TEXT,
-        0x00, 0x0d, // text length
+        0x00, 0x00, 0x00, 0x0d, // text length
         'h', 'e', 'l', 'l', 'o', ',', ' ', 'w', 'o', 'r', 'l', 'd', '!', // text
     };
     assert(!memcmp(buf, expected, sizeof(expected)));
@@ -56,13 +56,15 @@ static void test_serialize_inject_text_long(void) {
 
     unsigned char buf[CONTROL_MSG_MAX_SIZE];
     int size = control_msg_serialize(&msg, buf);
-    assert(size == 3 + CONTROL_MSG_INJECT_TEXT_MAX_LENGTH);
+    assert(size == 5 + CONTROL_MSG_INJECT_TEXT_MAX_LENGTH);
 
-    unsigned char expected[3 + CONTROL_MSG_INJECT_TEXT_MAX_LENGTH];
+    unsigned char expected[5 + CONTROL_MSG_INJECT_TEXT_MAX_LENGTH];
     expected[0] = CONTROL_MSG_TYPE_INJECT_TEXT;
-    expected[1] = 0x01;
-    expected[2] = 0x2c; // text length (16 bits)
-    memset(&expected[3], 'a', CONTROL_MSG_INJECT_TEXT_MAX_LENGTH);
+    expected[1] = 0x00;
+    expected[2] = 0x00;
+    expected[3] = 0x01;
+    expected[4] = 0x2c; // text length (32 bits)
+    memset(&expected[5], 'a', CONTROL_MSG_INJECT_TEXT_MAX_LENGTH);
 
     assert(!memcmp(buf, expected, sizeof(expected)));
 }
@@ -208,12 +210,12 @@ static void test_serialize_set_clipboard(void) {
 
     unsigned char buf[CONTROL_MSG_MAX_SIZE];
     int size = control_msg_serialize(&msg, buf);
-    assert(size == 17);
+    assert(size == 19);
 
     const unsigned char expected[] = {
         CONTROL_MSG_TYPE_SET_CLIPBOARD,
         1, // paste
-        0x00, 0x0d, // text length
+        0x00, 0x00, 0x00, 0x0d, // text length
         'h', 'e', 'l', 'l', 'o', ',', ' ', 'w', 'o', 'r', 'l', 'd', '!', // text
     };
     assert(!memcmp(buf, expected, sizeof(expected)));

app/tests/test_device_msg_deserialize.c

@@ -8,13 +8,13 @@
 static void test_deserialize_clipboard(void) {
     const unsigned char input[] = {
         DEVICE_MSG_TYPE_CLIPBOARD,
-        0x00, 0x03, // text length
+        0x00, 0x00, 0x00, 0x03, // text length
         0x41, 0x42, 0x43, // "ABC"
     };
 
     struct device_msg msg;
     ssize_t r = device_msg_deserialize(input, sizeof(input), &msg);
-    assert(r == 6);
+    assert(r == 8);
 
     assert(msg.type == DEVICE_MSG_TYPE_CLIPBOARD);
     assert(msg.clipboard.text);
@@ -26,10 +26,12 @@ static void test_deserialize_clipboard(void) {
 static void test_deserialize_clipboard_big(void) {
     unsigned char input[DEVICE_MSG_MAX_SIZE];
     input[0] = DEVICE_MSG_TYPE_CLIPBOARD;
-    input[1] = DEVICE_MSG_TEXT_MAX_LENGTH >> 8; // MSB
-    input[2] = DEVICE_MSG_TEXT_MAX_LENGTH & 0xff; // LSB
+    input[1] = (DEVICE_MSG_TEXT_MAX_LENGTH & 0xff000000u) >> 24;
+    input[2] = (DEVICE_MSG_TEXT_MAX_LENGTH & 0x00ff0000u) >> 16;
+    input[3] = (DEVICE_MSG_TEXT_MAX_LENGTH & 0x0000ff00u) >> 8;
+    input[4] =  DEVICE_MSG_TEXT_MAX_LENGTH & 0x000000ffu;
 
-    memset(input + 3, 'a', DEVICE_MSG_TEXT_MAX_LENGTH);
+    memset(input + 5, 'a', DEVICE_MSG_TEXT_MAX_LENGTH);
 
     struct device_msg msg;
     ssize_t r = device_msg_deserialize(input, sizeof(input), &msg);

server/src/main/java/com/genymobile/scrcpy/ControlMessageReader.java

@@ -16,7 +16,7 @@ public class ControlMessageReader {
 
     private static final int MESSAGE_MAX_SIZE = 4096;
 
-    public static final int CLIPBOARD_TEXT_MAX_LENGTH = MESSAGE_MAX_SIZE - 4; // type: 1 byte; paste flag: 1 byte; length: 2 bytes
+    public static final int CLIPBOARD_TEXT_MAX_LENGTH = MESSAGE_MAX_SIZE - 6; // type: 1 byte; paste flag: 1 byte; length: 4 bytes
     public static final int INJECT_TEXT_MAX_LENGTH = 300;
 
     private final byte[] rawBuffer = new byte[MESSAGE_MAX_SIZE];
@@ -103,10 +103,10 @@ public class ControlMessageReader {
     }
 
     private String parseString() {
-        if (buffer.remaining() < 2) {
+        if (buffer.remaining() < 4) {
             return null;
         }
-        int len = toUnsigned(buffer.getShort());
+        int len = buffer.getInt();
         if (buffer.remaining() < len) {
             return null;
         }

server/src/main/java/com/genymobile/scrcpy/DeviceMessageWriter.java

@@ -8,7 +8,7 @@ import java.nio.charset.StandardCharsets;
 public class DeviceMessageWriter {
 
     private static final int MESSAGE_MAX_SIZE = 4096;
-    public static final int CLIPBOARD_TEXT_MAX_LENGTH = MESSAGE_MAX_SIZE - 3; // type: 1 byte; length: 2 bytes
+    public static final int CLIPBOARD_TEXT_MAX_LENGTH = MESSAGE_MAX_SIZE - 5; // type: 1 byte; length: 4 bytes
 
     private final byte[] rawBuffer = new byte[MESSAGE_MAX_SIZE];
     private final ByteBuffer buffer = ByteBuffer.wrap(rawBuffer);
@@ -21,7 +21,7 @@ public class DeviceMessageWriter {
                 String text = msg.getText();
                 byte[] raw = text.getBytes(StandardCharsets.UTF_8);
                 int len = StringUtils.getUtf8TruncationIndex(raw, CLIPBOARD_TEXT_MAX_LENGTH);
-                buffer.putShort((short) len);
+                buffer.putInt(len);
                 buffer.put(raw, 0, len);
                 output.write(rawBuffer, 0, buffer.position());
                 break;

server/src/test/java/com/genymobile/scrcpy/ControlMessageReaderTest.java

@@ -48,7 +48,7 @@ public class ControlMessageReaderTest {
         DataOutputStream dos = new DataOutputStream(bos);
         dos.writeByte(ControlMessage.TYPE_INJECT_TEXT);
         byte[] text = "testé".getBytes(StandardCharsets.UTF_8);
-        dos.writeShort(text.length);
+        dos.writeInt(text.length);
         dos.write(text);
         byte[] packet = bos.toByteArray();
 
@@ -68,7 +68,7 @@ public class ControlMessageReaderTest {
         dos.writeByte(ControlMessage.TYPE_INJECT_TEXT);
         byte[] text = new byte[ControlMessageReader.INJECT_TEXT_MAX_LENGTH];
         Arrays.fill(text, (byte) 'a');
-        dos.writeShort(text.length);
+        dos.writeInt(text.length);
         dos.write(text);
         byte[] packet = bos.toByteArray();
 
@@ -218,7 +218,7 @@ public class ControlMessageReaderTest {
         dos.writeByte(ControlMessage.TYPE_SET_CLIPBOARD);
         dos.writeByte(1); // paste
         byte[] text = "testé".getBytes(StandardCharsets.UTF_8);
-        dos.writeShort(text.length);
+        dos.writeInt(text.length);
         dos.write(text);
 
         byte[] packet = bos.toByteArray();
@@ -246,7 +246,7 @@ public class ControlMessageReaderTest {
         Arrays.fill(rawText, (byte) 'a');
         String text = new String(rawText, 0, rawText.length);
 
-        dos.writeShort(rawText.length);
+        dos.writeInt(rawText.length);
         dos.write(rawText);
 
         byte[] packet = bos.toByteArray();

server/src/test/java/com/genymobile/scrcpy/DeviceMessageWriterTest.java

@@ -19,7 +19,7 @@ public class DeviceMessageWriterTest {
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         DataOutputStream dos = new DataOutputStream(bos);
         dos.writeByte(DeviceMessage.TYPE_CLIPBOARD);
-        dos.writeShort(data.length);
+        dos.writeInt(data.length);
         dos.write(data);
 
         byte[] expected = bos.toByteArray();