133 lines
2.8 KiB
Go
133 lines
2.8 KiB
Go
package udp
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import (
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"context"
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"net"
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"github.com/anacrolix/log"
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"github.com/anacrolix/missinggo/v2"
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)
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type listenPacketFunc func(network, addr string) (net.PacketConn, error)
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type NewConnClientOpts struct {
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// The network to operate to use, such as "udp4", "udp", "udp6".
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Network string
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// Tracker address
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Host string
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// If non-nil, forces either IPv4 or IPv6 in the UDP tracker wire protocol.
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Ipv6 *bool
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// Logger to use for internal errors.
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Logger log.Logger
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// Custom function to use as a substitute for net.ListenPacket
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ListenPacket listenPacketFunc
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}
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// Manages a Client with a specific connection.
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type ConnClient struct {
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Client Client
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conn net.PacketConn
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d Dispatcher
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readErr error
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closed bool
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newOpts NewConnClientOpts
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}
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func (cc *ConnClient) reader() {
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b := make([]byte, 0x800)
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for {
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n, addr, err := cc.conn.ReadFrom(b)
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if err != nil {
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// TODO: Do bad things to the dispatcher, and incoming calls to the client if we have a
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// read error.
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cc.readErr = err
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if !cc.closed {
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panic(err)
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}
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break
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}
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err = cc.d.Dispatch(b[:n], addr)
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if err != nil {
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cc.newOpts.Logger.Levelf(log.Debug, "dispatching packet received on %v: %v", cc.conn.LocalAddr(), err)
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}
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}
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}
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func ipv6(opt *bool, network string, remoteAddr net.Addr) bool {
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if opt != nil {
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return *opt
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}
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switch network {
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case "udp4":
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return false
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case "udp6":
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return true
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}
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rip := missinggo.AddrIP(remoteAddr)
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return rip.To16() != nil && rip.To4() == nil
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}
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// Allows a UDP Client to write packets to an endpoint without knowing about the network specifics.
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type clientWriter struct {
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pc net.PacketConn
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network string
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address string
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}
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func (me clientWriter) Write(p []byte) (n int, err error) {
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addr, err := net.ResolveUDPAddr(me.network, me.address)
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if err != nil {
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return
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}
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return me.pc.WriteTo(p, addr)
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}
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func NewConnClient(opts NewConnClientOpts) (cc *ConnClient, err error) {
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var conn net.PacketConn
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if opts.ListenPacket != nil {
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conn, err = opts.ListenPacket(opts.Network, ":0")
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} else {
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conn, err = net.ListenPacket(opts.Network, ":0")
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}
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if err != nil {
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return
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}
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if opts.Logger.IsZero() {
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opts.Logger = log.Default
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}
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cc = &ConnClient{
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Client: Client{
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Writer: clientWriter{
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pc: conn,
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network: opts.Network,
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address: opts.Host,
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},
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},
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conn: conn,
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newOpts: opts,
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}
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cc.Client.Dispatcher = &cc.d
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go cc.reader()
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return
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}
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func (cc *ConnClient) Close() error {
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cc.closed = true
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return cc.conn.Close()
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}
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func (cc *ConnClient) Announce(
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ctx context.Context, req AnnounceRequest, opts Options,
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) (
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h AnnounceResponseHeader, nas AnnounceResponsePeers, err error,
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) {
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return cc.Client.Announce(ctx, req, opts, func(addr net.Addr) bool {
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return ipv6(cc.newOpts.Ipv6, cc.newOpts.Network, addr)
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})
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}
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func (cc *ConnClient) LocalAddr() net.Addr {
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return cc.conn.LocalAddr()
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}
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