status-go/vendor/github.com/anacrolix/torrent/tracker/udp/conn-client.go

124 lines
2.5 KiB
Go

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