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Cannot connect to some MQTT server when the connect packet sent in chunk instead of full packet at once #123

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@gazsiazasz

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@gazsiazasz

I am trying to connect to an MQTT server over websocket(was actually, but I think it doesn't matter).
But the connection attempt fails, because the client sends the connect packet in little chunks:

stream.write(protocol.CONNECT_HEADER)
// Generate length
writeVarByteInt(stream, length)
// Generate protocol ID
writeStringOrBuffer(stream, protocolId)
if (settings.bridgeMode) {
protocolVersion += 128
}
stream.write(
protocolVersion === 131
? protocol.VERSION131
: protocolVersion === 132
? protocol.VERSION132
: protocolVersion === 4
? protocol.VERSION4
: protocolVersion === 5
? protocol.VERSION5
: protocol.VERSION3
)
// Connect flags
let flags = 0
flags |= (username != null) ? protocol.USERNAME_MASK : 0
flags |= (password != null) ? protocol.PASSWORD_MASK : 0
flags |= (will && will.retain) ? protocol.WILL_RETAIN_MASK : 0
flags |= (will && will.qos) ? will.qos << protocol.WILL_QOS_SHIFT : 0
flags |= will ? protocol.WILL_FLAG_MASK : 0
flags |= clean ? protocol.CLEAN_SESSION_MASK : 0
stream.write(Buffer.from([flags]))
// Keepalive
writeNumber(stream, keepalive)
// Properties
if (protocolVersion === 5) {
propertiesData.write()
}
// Client ID
writeStringOrBuffer(stream, clientId)
// Will
if (will) {
if (protocolVersion === 5) {
willProperties.write()
}
writeString(stream, will.topic)
writeStringOrBuffer(stream, will.payload)
}
// Username and password
if (username != null) {
writeStringOrBuffer(stream, username)
}
if (password != null) {
writeStringOrBuffer(stream, password)
}

I tried to connect with replacing the whole packet generation with a hardcoded one, and it immediately succeeds to connect:

conbuf = Buffer.from([0x10, 0x38, 0x00, 0x04, 0x4d, 0x51, 0x54, 0x54, 0x04, 0xc2, 0x00, 0x1e, 0x00, 0x20, 0x36, 0x37, 0x61, 0x64, 0x33, 0x63, 0x63, 0x35, 0x63, 0x31, 0x31, 0x33, 0x34, 0x35, 0x63, 0x31, 0x39, 0x37, 0x64, 0x38, 0x33, 0x36, 0x31, 0x39, 0x61, 0x63, 0x64, 0x37, 0x30, 0x66, 0x31, 0x63, 0x00, 0x04, 0x74, 0x65, 0x73, 0x74, 0x00, 0x04, 0x74, 0x65, 0x73, 0x74]) stream.write(conbuf)

The same problem appears with the subscribe command.

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