chenBright commented on code in PR #3350: URL: https://github.com/apache/brpc/pull/3350#discussion_r3608108503
########## src/brpc/policy/rdma_handshake_protocol.h: ########## @@ -0,0 +1,56 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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 BRPC_POLICY_RDMA_HANDSHAKE_PROTOCOL_H +#define BRPC_POLICY_RDMA_HANDSHAKE_PROTOCOL_H + +// NOTE: This file is intentionally INDEPENDENT of BRPC_WITH_RDMA. A server may +// run in TCP mode either because it was built without RDMA, or because RDMA was +// not enabled at runtime. In both cases an RDMA client that connects to it will +// send an RDMA handshake magic ("RDMA" for v2, "RDM3" for v3) first. Without +// special handling the server treats those bytes as an unknown protocol and +// closes the connection, so the client (blocked reading the server hello) only +// sees EOF and cannot fall back to TCP. +// +// To let the client fall back on the SAME connection, the server recognizes the +// RDMA handshake as a "first-class" protocol (magic in the first 4 bytes, +// PROTOCOL_RDMA_HANDSHAKE is ordered before PROTOCOL_HTTP), replies a hello with +// an incompatible version so the client rejects it and downgrades to TCP, then +// drains the client's subsequent ACK and lets normal RPC parsing continue. + +#include "butil/iobuf.h" +#include "brpc/input_message_base.h" +#include "brpc/parse_result.h" +#include "brpc/socket.h" + +namespace brpc { +namespace policy { + +// Parse binary format of rdma handshake. +ParseResult ParseRdmaHandshake(butil::IOBuf* source, Socket* socket, + bool read_eof, const void* arg); + +// Actions to a rdma handshake request, which is left unimplemented. +// All requests are processed in the parsing process. This function +// must be declared since server only enables redis as a server-side Review Comment: done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
