/* Copyright 2022 CAcert Inc. SPDX-License-Identifier: Apache-2.0 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. */ // client simulator package main import ( "bytes" "context" "fmt" "os" "sync" "time" "github.com/justincpresley/go-cobs" "github.com/shamaton/msgpackgen/msgpack" "github.com/sirupsen/logrus" "git.cacert.org/cacert-gosigner/pkg/protocol" "git.cacert.org/cacert-gosigner/pkg/messages" ) const cobsDelimiter = 0x00 var cobsConfig = cobs.Config{SpecialByte: cobsDelimiter, Delimiter: true, EndingSave: true} func main() { logger := logrus.New() logger.SetOutput(os.Stderr) logger.SetLevel(logrus.InfoLevel) sim := &clientSimulator{ logger: logger, } err := sim.Run() if err != nil { logger.WithError(err).Error("simulator returned an error") } } type clientSimulator struct { logger *logrus.Logger commands chan *protocol.Command responses chan [][]byte } func (c *clientSimulator) writeTestCommands(ctx context.Context) error { messages.RegisterGeneratedResolver() const healthInterval = 10 * time.Second time.Sleep(healthInterval) c.commands <- &protocol.Command{ Announce: messages.BuildCommandAnnounce(messages.CmdFetchCRL), Command: &messages.FetchCRLCommand{IssuerID: "sub-ecc_person_2022"}, } timer := time.NewTimer(healthInterval) for { select { case <-ctx.Done(): _ = timer.Stop() c.logger.Info("stopping health check loop") return nil case <-timer.C: c.commands <- &protocol.Command{ Announce: messages.BuildCommandAnnounce(messages.CmdHealth), Command: &messages.HealthCommand{}, } } timer.Reset(healthInterval) } } func (c *clientSimulator) handleInput(ctx context.Context) error { const ( bufferSize = 1024 * 1024 readInterval = 50 * time.Millisecond ) buf := make([]byte, bufferSize) type protocolState int8 const ( stAnn protocolState = iota stResp ) state := stAnn var announce []byte reading: for { select { case <-ctx.Done(): return nil default: count, err := os.Stdin.Read(buf) if err != nil { return fmt.Errorf("reading input failed: %w", err) } if count == 0 { time.Sleep(readInterval) continue } data := buf[:count] for _, frame := range bytes.SplitAfter(data, []byte{cobsConfig.SpecialByte}) { if len(frame) == 0 { continue reading } err = cobs.Verify(frame, cobsConfig) if err != nil { return fmt.Errorf("frame verification failed: %w", err) } if state == stAnn { announce = cobs.Decode(frame, cobsConfig) state = stResp } else { c.responses <- [][]byte{announce, cobs.Decode(frame, cobsConfig)} state = stAnn } } } } } func (c *clientSimulator) handleCommands(ctx context.Context) error { for { select { case command := <-c.commands: if err := writeCommandAnnouncement(command); err != nil { return err } if err := writeCommand(command); err != nil { return err } respData := <-c.responses c.logger.WithField("respdata", respData).Trace("read response data") response := &protocol.Response{} if err := msgpack.Unmarshal(respData[0], &response.Announce); err != nil { return fmt.Errorf("could not unmarshal response announcement: %w", err) } if err := c.handleResponse(response, respData[1]); err != nil { return err } case <-ctx.Done(): return nil } } } func (c *clientSimulator) handleResponse(response *protocol.Response, respBytes []byte) error { switch response.Announce.Code { case messages.RespHealth: data := messages.HealthResponse{} if err := msgpack.Unmarshal(respBytes, &data); err != nil { return fmt.Errorf("could not unmarshal health data: %w", err) } c.logger.WithField( "announce", response.Announce, ).WithField( "data", &data, ).Infof("received response") case messages.RespFetchCRL: data := messages.FetchCRLResponse{} if err := msgpack.Unmarshal(respBytes, &data); err != nil { return fmt.Errorf("could not unmarshal fetch CRL data: %w", err) } c.logger.WithField( "announce", response.Announce, ).WithField( "data", &data, ).Infof("received response") case messages.RespError: data := messages.ErrorResponse{} if err := msgpack.Unmarshal(respBytes, &data); err != nil { return fmt.Errorf("could not unmarshal error data: %w", err) } c.logger.WithField( "announce", response.Announce, ).WithField( "data", &data, ).Infof("received response") default: if err := msgpack.Unmarshal(respBytes, &response.Response); err != nil { return fmt.Errorf("could not unmarshal response: %w", err) } c.logger.WithField("response", response).Infof("received response") } return nil } func writeCommandAnnouncement(command *protocol.Command) error { cmdAnnounceBytes, err := msgpack.Marshal(&command.Announce) if err != nil { return fmt.Errorf("could not marshal command announcement bytes: %w", err) } if _, err = os.Stdout.Write(cobs.Encode(cmdAnnounceBytes, cobsConfig)); err != nil { return fmt.Errorf("command announcement write failed: %w", err) } return nil } func writeCommand(command *protocol.Command) error { cmdBytes, err := msgpack.Marshal(&command.Command) if err != nil { return fmt.Errorf("could not marshal command bytes: %w", err) } if _, err = os.Stdout.Write(cobs.Encode(cmdBytes, cobsConfig)); err != nil { return fmt.Errorf("command write failed: %w", err) } return nil } func (c *clientSimulator) Run() error { ctx, cancel := context.WithCancel(context.Background()) c.commands = make(chan *protocol.Command) c.responses = make(chan [][]byte) wg := sync.WaitGroup{} wg.Add(2) go func() { if err := c.handleInput(ctx); err != nil { c.logger.WithError(err).Error("input handling failed") } cancel() wg.Done() }() go func() { if err := c.handleCommands(ctx); err != nil { c.logger.WithError(err).Error("command handling failed") } cancel() wg.Done() }() var result error if err := c.writeTestCommands(ctx); err != nil { c.logger.WithError(err).Error("test commands failed") } cancel() wg.Wait() return result }