82 lines
2.7 KiB
Go
82 lines
2.7 KiB
Go
/*
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Copyright © 2021 Arsen Musayelyan
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package main
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import (
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"context"
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"github.com/grandcat/zeroconf"
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"github.com/rs/zerolog"
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"github.com/rs/zerolog/log"
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"os"
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"time"
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)
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// Discover opensend receivers on the network
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func DiscoverReceivers() ([]string, []string) {
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// Use ConsoleWriter logger
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log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stderr}).Hook(FatalHook{})
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// Create zeroconf resolver
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resolver, err := zeroconf.NewResolver(nil)
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if err != nil {
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log.Fatal().Err(err).Msg("Error creating zeroconf resolver")
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}
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// Create channel for zeroconf entries
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entries := make(chan *zeroconf.ServiceEntry)
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// Create slice to store hostnames of discovered receivers
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var discoveredReceivers []string
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// Create slice to store IPs of discovered receivers
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var discoveredReceiverIPs []string
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// Concurrently run mDNS query
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go func(results <-chan *zeroconf.ServiceEntry) {
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// For each entry
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for entry := range results {
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// Append hostname to discoveredReceivers
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discoveredReceivers = append(discoveredReceivers, entry.HostName)
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// Append IP to discoveredReceiverIPs
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discoveredReceiverIPs = append(discoveredReceiverIPs, entry.AddrIPv4[0].String())
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}
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}(entries)
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// Create context with 4 second timeout
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ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
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// Cancel context at the end of this function
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defer cancel()
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// Browse for mDNS entries
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err = resolver.Browse(ctx, "_opensend._tcp", "local.", entries)
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if err != nil {
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log.Fatal().Err(err).Msg("Error browsing zeroconf services")
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}
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// Send Done signal to context
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<-ctx.Done()
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// Return discovered receiver slices
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return discoveredReceivers, discoveredReceiverIPs
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}
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// Register opensend zeroconf service on the network
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func RegisterService() func() {
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// Get computer hostname
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hostname, _ := os.Hostname()
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// Register zeroconf service {hostname}._opensend._tcp.local.
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server, err := zeroconf.Register(hostname, "_opensend._tcp", "local.", 9797, []string{"txtv=0", "lo=1", "la=2"}, nil)
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if err != nil {
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log.Fatal().Err(err).Msg("Error registering zeroconf service")
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}
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// Return server.Shutdown() function to allow for shutdown in main()
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return server.Shutdown
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}
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