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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-11-16 01:17:30 -05:00
v2fly/proxy/socks/udp.go
2015-09-28 14:57:43 +02:00

103 lines
2.1 KiB
Go

package socks
import (
"math"
"math/rand"
"net"
"sync"
"github.com/v2ray/v2ray-core/common/collect"
"github.com/v2ray/v2ray-core/common/log"
v2net "github.com/v2ray/v2ray-core/common/net"
"github.com/v2ray/v2ray-core/proxy/socks/protocol"
)
const (
bufferSize = 2 * 1024
)
type portMap struct {
access sync.Mutex
data map[uint16]*net.UDPAddr
removedPorts *collect.TimedQueue
}
func newPortMap() *portMap {
m := &portMap{
access: sync.Mutex{},
data: make(map[uint16]*net.UDPAddr),
removedPorts: collect.NewTimedQueue(1),
}
go m.removePorts(m.removedPorts.RemovedEntries())
return m
}
func (m *portMap) assignAddressToken(addr *net.UDPAddr) uint16 {
for {
token := uint16(rand.Intn(math.MaxUint16))
if _, used := m.data[token]; !used {
m.access.Lock()
if _, used = m.data[token]; !used {
m.data[token] = addr
m.access.Unlock()
return token
}
m.access.Unlock()
}
}
}
func (m *portMap) removePorts(removedPorts <-chan interface{}) {
for {
rawToken := <-removedPorts
m.access.Lock()
delete(m.data, rawToken.(uint16))
m.access.Unlock()
}
}
var (
ports = newPortMap()
)
func (server *SocksServer) ListenUDP(port uint16) error {
addr := &net.UDPAddr{
IP: net.IP{0, 0, 0, 0},
Port: int(port),
Zone: "",
}
conn, err := net.ListenUDP("udp", addr)
if err != nil {
log.Error("Socks failed to listen UDP on port %d: %v", port, err)
return err
}
go server.AcceptPackets(conn)
return nil
}
func (server *SocksServer) AcceptPackets(conn *net.UDPConn) error {
for {
buffer := make([]byte, 0, bufferSize)
nBytes, addr, err := conn.ReadFromUDP(buffer)
if err != nil {
log.Error("Socks failed to read UDP packets: %v", err)
return err
}
request, err := protocol.ReadUDPRequest(buffer[:nBytes])
if err != nil {
log.Error("Socks failed to parse UDP request: %v", err)
return err
}
if request.Fragment != 0 {
// TODO handle fragments
continue
}
token := ports.assignAddressToken(addr)
udpPacket := v2net.NewUDPPacket(request.Destination(), request.Data, token)
server.vPoint.DispatchToOutbound(udpPacket)
}
}