90 lines
1.9 KiB
Go
90 lines
1.9 KiB
Go
package addrutil
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import (
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"context"
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"fmt"
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"sync"
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"time"
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"github.com/libp2p/go-libp2p-core/peer"
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ma "github.com/multiformats/go-multiaddr"
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madns "github.com/multiformats/go-multiaddr-dns"
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)
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// parseAddresses is a function that takes in a slice of string peer addresses
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// (multiaddr + peerid) and returns a slice of properly constructed peers
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func ParseAddresses(ctx context.Context, addrs []string) ([]peer.AddrInfo, error) {
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// resolve addresses
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maddrs, err := resolveAddresses(ctx, addrs)
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if err != nil {
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return nil, err
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}
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return peer.AddrInfosFromP2pAddrs(maddrs...)
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}
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const (
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dnsResolveTimeout = 10 * time.Second
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)
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// resolveAddresses resolves addresses parallelly
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func resolveAddresses(ctx context.Context, addrs []string) ([]ma.Multiaddr, error) {
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ctx, cancel := context.WithTimeout(ctx, dnsResolveTimeout)
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defer cancel()
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var maddrs []ma.Multiaddr
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var wg sync.WaitGroup
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resolveErrC := make(chan error, len(addrs))
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maddrC := make(chan ma.Multiaddr)
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for _, addr := range addrs {
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maddr, err := ma.NewMultiaddr(addr)
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if err != nil {
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return nil, err
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}
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// check whether address ends in `ipfs/Qm...`
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if _, last := ma.SplitLast(maddr); last.Protocol().Code == ma.P_IPFS {
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maddrs = append(maddrs, maddr)
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continue
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}
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wg.Add(1)
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go func(maddr ma.Multiaddr) {
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defer wg.Done()
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raddrs, err := madns.Resolve(ctx, maddr)
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if err != nil {
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resolveErrC <- err
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return
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}
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// filter out addresses that still doesn't end in `ipfs/Qm...`
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found := 0
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for _, raddr := range raddrs {
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if _, last := ma.SplitLast(raddr); last != nil && last.Protocol().Code == ma.P_IPFS {
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maddrC <- raddr
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found++
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}
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}
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if found == 0 {
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resolveErrC <- fmt.Errorf("found no ipfs peers at %s", maddr)
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}
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}(maddr)
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}
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go func() {
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wg.Wait()
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close(maddrC)
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}()
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for maddr := range maddrC {
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maddrs = append(maddrs, maddr)
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}
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select {
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case err := <-resolveErrC:
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return nil, err
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default:
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}
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return maddrs, nil
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}
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