x.websocket: move to net.websocket module (#10648)

vlib/net/websocket/handshake.v

@@ -0,0 +1,185 @@
+[manualfree]
+module websocket
+
+import encoding.base64
+import strings
+
+// handshake manages the websocket handshake process
+fn (mut ws Client) handshake() ? {
+	nonce := get_nonce(ws.nonce_size)
+	seckey := base64.encode_str(nonce)
+	mut sb := strings.new_builder(1024)
+	defer {
+		unsafe { sb.free() }
+	}
+	sb.write_string('GET ')
+	sb.write_string(ws.uri.resource)
+	sb.write_string(ws.uri.querystring)
+	sb.write_string(' HTTP/1.1\r\nHost: ')
+	sb.write_string(ws.uri.hostname)
+	sb.write_string(':')
+	sb.write_string(ws.uri.port)
+	sb.write_string('\r\nUpgrade: websocket\r\nConnection: Upgrade\r\n')
+	sb.write_string('Sec-WebSocket-Key: ')
+	sb.write_string(seckey)
+	sb.write_string('\r\nSec-WebSocket-Version: 13')
+	for key in ws.header.keys() {
+		val := ws.header.custom_values(key).join(',')
+		sb.write_string('\r\n$key:$val')
+	}
+	sb.write_string('\r\n\r\n')
+	handshake := sb.str()
+	defer {
+		unsafe { handshake.free() }
+	}
+	handshake_bytes := handshake.bytes()
+	ws.debug_log('sending handshake: $handshake')
+	ws.socket_write(handshake_bytes) ?
+	ws.read_handshake(seckey) ?
+	unsafe { handshake_bytes.free() }
+}
+
+// handle_server_handshake manages websocket server handshake process
+fn (mut s Server) handle_server_handshake(mut c Client) ?(string, &ServerClient) {
+	msg := c.read_handshake_str() ?
+	handshake_response, client := s.parse_client_handshake(msg, mut c) ?
+	unsafe { msg.free() }
+	return handshake_response, client
+}
+
+// parse_client_handshake parses result from handshake process
+fn (mut s Server) parse_client_handshake(client_handshake string, mut c Client) ?(string, &ServerClient) {
+	s.logger.debug('server-> client handshake:\n$client_handshake')
+	lines := client_handshake.split_into_lines()
+	get_tokens := lines[0].split(' ')
+	if get_tokens.len < 3 {
+		return error_with_code('unexpected get operation, $get_tokens', 1)
+	}
+	if get_tokens[0].trim_space() != 'GET' {
+		return error_with_code("unexpected request '${get_tokens[0]}', expected 'GET'",
+			2)
+	}
+	if get_tokens[2].trim_space() != 'HTTP/1.1' {
+		return error_with_code("unexpected request $get_tokens, expected 'HTTP/1.1'",
+			3)
+	}
+	mut seckey := ''
+	mut flags := []Flag{}
+	mut key := ''
+	for i in 1 .. lines.len {
+		if lines[i].len <= 0 || lines[i] == '\r\n' {
+			continue
+		}
+		keys := lines[i].split(':')
+		match keys[0] {
+			'Upgrade', 'upgrade' {
+				flags << .has_upgrade
+			}
+			'Connection', 'connection' {
+				flags << .has_connection
+			}
+			'Sec-WebSocket-Key', 'sec-websocket-key' {
+				key = keys[1].trim_space()
+				s.logger.debug('server-> got key: $key')
+				seckey = create_key_challenge_response(key) ?
+				s.logger.debug('server-> challenge: $seckey, response: ${keys[1]}')
+				flags << .has_accept
+			}
+			else {
+				// we ignore other headers like protocol for now
+			}
+		}
+		unsafe { keys.free() }
+	}
+	if flags.len < 3 {
+		return error_with_code('invalid client handshake, $client_handshake', 4)
+	}
+	server_handshake := 'HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: $seckey\r\n\r\n'
+	server_client := &ServerClient{
+		resource_name: get_tokens[1]
+		client_key: key
+		client: unsafe { c }
+		server: unsafe { s }
+	}
+	unsafe {
+		lines.free()
+		flags.free()
+		get_tokens.free()
+		seckey.free()
+		key.free()
+	}
+	return server_handshake, server_client
+}
+
+// read_handshake_str returns the handshake response
+fn (mut ws Client) read_handshake_str() ?string {
+	mut total_bytes_read := 0
+	mut msg := [1024]byte{}
+	mut buffer := [1]byte{}
+	for total_bytes_read < 1024 {
+		bytes_read := ws.socket_read_ptr(&buffer[0], 1) ?
+		if bytes_read == 0 {
+			return error_with_code('unexpected no response from handshake', 5)
+		}
+		msg[total_bytes_read] = buffer[0]
+		total_bytes_read++
+		if total_bytes_read > 5 && msg[total_bytes_read - 1] == `\n`
+			&& msg[total_bytes_read - 2] == `\r` && msg[total_bytes_read - 3] == `\n`
+			&& msg[total_bytes_read - 4] == `\r` {
+			break
+		}
+	}
+	res := msg[..total_bytes_read].bytestr()
+	return res
+}
+
+// read_handshake reads the handshake result and check if valid
+fn (mut ws Client) read_handshake(seckey string) ? {
+	mut msg := ws.read_handshake_str() ?
+	ws.check_handshake_response(msg, seckey) ?
+	unsafe { msg.free() }
+}
+
+// check_handshake_response checks the response from handshake and returns
+// the response and secure key provided by the websocket client
+fn (mut ws Client) check_handshake_response(handshake_response string, seckey string) ? {
+	ws.debug_log('handshake response:\n$handshake_response')
+	lines := handshake_response.split_into_lines()
+	header := lines[0]
+	if !header.starts_with('HTTP/1.1 101') && !header.starts_with('HTTP/1.0 101') {
+		return error_with_code('handshake_handler: invalid HTTP status response code, $header',
+			6)
+	}
+	for i in 1 .. lines.len {
+		if lines[i].len <= 0 || lines[i] == '\r\n' {
+			continue
+		}
+		keys := lines[i].split(':')
+		match keys[0] {
+			'Upgrade', 'upgrade' {
+				ws.flags << .has_upgrade
+			}
+			'Connection', 'connection' {
+				ws.flags << .has_connection
+			}
+			'Sec-WebSocket-Accept', 'sec-websocket-accept' {
+				ws.debug_log('seckey: $seckey')
+				challenge := create_key_challenge_response(seckey) ?
+				ws.debug_log('challenge: $challenge, response: ${keys[1]}')
+				if keys[1].trim_space() != challenge {
+					return error_with_code('handshake_handler: Sec-WebSocket-Accept header does not match computed sha1/base64 response.',
+						7)
+				}
+				ws.flags << .has_accept
+				unsafe { challenge.free() }
+			}
+			else {}
+		}
+		unsafe { keys.free() }
+	}
+	unsafe { lines.free() }
+	if ws.flags.len < 3 {
+		ws.close(1002, 'invalid websocket HTTP headers') ?
+		return error_with_code('invalid websocket HTTP headers', 8)
+	}
+}