| // Copyright 2018 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| package main |
| |
| import ( |
| "context" |
| "encoding/json" |
| "errors" |
| "flag" |
| "fmt" |
| "log" |
| "net" |
| "os" |
| |
| "github.com/google/subcommands" |
| |
| "fuchsia.googlesource.com/tools/mdns" |
| ) |
| |
| const ( |
| ipv4AddrLength = 4 |
| ) |
| |
| type resolveCmd struct { |
| devFinderCmd |
| } |
| |
| func (*resolveCmd) Name() string { |
| return "resolve" |
| } |
| |
| func (*resolveCmd) Usage() string { |
| return "resolve [flags...] [domains...]\n\nflags:\n" |
| } |
| |
| func (*resolveCmd) Synopsis() string { |
| return "attempts to resolve all passed Fuchsia domain names on the network" |
| } |
| |
| func (cmd *resolveCmd) SetFlags(f *flag.FlagSet) { |
| cmd.SetCommonFlags(f) |
| } |
| |
| func resolveMDNSHandler(resp mDNSResponse, localResolve bool, devChan chan<- *fuchsiaDevice, errChan chan<- error) { |
| for _, a := range resp.rxPacket.Answers { |
| if a.Class == mdns.IN && a.Type == mdns.A && |
| len(a.Data) == ipv4AddrLength { |
| if localResolve { |
| recvIP, err := resp.getReceiveIP() |
| if err != nil { |
| errChan <- err |
| return |
| } |
| devChan <- &fuchsiaDevice{recvIP, a.Domain} |
| continue |
| } |
| devChan <- &fuchsiaDevice{net.IP(a.Data), a.Domain} |
| } |
| } |
| } |
| |
| func (cmd *resolveCmd) execute(ctx context.Context, domains ...string) error { |
| if len(domains) == 0 { |
| return errors.New("no domains supplied") |
| } |
| |
| var outDevices []*fuchsiaDevice |
| for _, domain := range domains { |
| mDNSDomain := fmt.Sprintf("%s.local", domain) |
| devices, err := cmd.sendMDNSPacket(ctx, mdns.QuestionPacket(mDNSDomain)) |
| if err != nil { |
| return fmt.Errorf("sending/receiving mdns packets during resolve of domain '%s': %v", domain, err) |
| } |
| filteredDevices := make([]*fuchsiaDevice, 0) |
| for _, device := range devices { |
| if device.domain == mDNSDomain { |
| filteredDevices = append(filteredDevices, device) |
| } |
| } |
| if len(filteredDevices) == 0 { |
| return fmt.Errorf("no devices with domain %v", domain) |
| } |
| |
| for _, device := range filteredDevices { |
| outDevices = append(outDevices, device) |
| } |
| } |
| |
| if cmd.json { |
| return cmd.outputJSON(outDevices) |
| } |
| return cmd.outputNormal(outDevices) |
| } |
| |
| func (cmd *resolveCmd) outputNormal(devices []*fuchsiaDevice) error { |
| for _, device := range devices { |
| fmt.Println(device.addr) |
| } |
| return nil |
| } |
| |
| func (cmd *resolveCmd) outputJSON(devices []*fuchsiaDevice) error { |
| jsonOut := jsonOutput{Devices: make([]jsonDevice, 0, len(devices))} |
| for _, device := range devices { |
| jsonOut.Devices = append(jsonOut.Devices, jsonDevice{Addr: device.addr.String()}) |
| } |
| |
| e := json.NewEncoder(os.Stdout) |
| e.SetIndent("", " ") |
| return e.Encode(jsonOut) |
| } |
| |
| func (cmd *resolveCmd) Execute(ctx context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus { |
| cmd.mdnsHandler = resolveMDNSHandler |
| if err := cmd.execute(ctx, f.Args()...); err != nil { |
| log.Print(err) |
| return subcommands.ExitFailure |
| } |
| return subcommands.ExitSuccess |
| } |