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v2fly/proxy/socks/client.go
2022-01-03 15:55:18 +00:00

232 lines
7.0 KiB
Go

package socks
import (
"context"
"time"
"github.com/v2fly/v2ray-core/v5/common/net/packetaddr"
"github.com/v2fly/v2ray-core/v5/transport/internet/udp"
core "github.com/v2fly/v2ray-core/v5"
"github.com/v2fly/v2ray-core/v5/common"
"github.com/v2fly/v2ray-core/v5/common/buf"
"github.com/v2fly/v2ray-core/v5/common/net"
"github.com/v2fly/v2ray-core/v5/common/protocol"
"github.com/v2fly/v2ray-core/v5/common/retry"
"github.com/v2fly/v2ray-core/v5/common/session"
"github.com/v2fly/v2ray-core/v5/common/signal"
"github.com/v2fly/v2ray-core/v5/common/task"
"github.com/v2fly/v2ray-core/v5/features/dns"
"github.com/v2fly/v2ray-core/v5/features/policy"
"github.com/v2fly/v2ray-core/v5/transport"
"github.com/v2fly/v2ray-core/v5/transport/internet"
)
// Client is a Socks5 client.
type Client struct {
serverPicker protocol.ServerPicker
policyManager policy.Manager
version Version
dns dns.Client
}
// NewClient create a new Socks5 client based on the given config.
func NewClient(ctx context.Context, config *ClientConfig) (*Client, error) {
serverList := protocol.NewServerList()
for _, rec := range config.Server {
s, err := protocol.NewServerSpecFromPB(rec)
if err != nil {
return nil, newError("failed to get server spec").Base(err)
}
serverList.AddServer(s)
}
if serverList.Size() == 0 {
return nil, newError("0 target server")
}
v := core.MustFromContext(ctx)
c := &Client{
serverPicker: protocol.NewRoundRobinServerPicker(serverList),
policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
version: config.Version,
}
if config.Version == Version_SOCKS4 {
c.dns = v.GetFeature(dns.ClientType()).(dns.Client)
}
return c, nil
}
// Process implements proxy.Outbound.Process.
func (c *Client) Process(ctx context.Context, link *transport.Link, dialer internet.Dialer) error {
outbound := session.OutboundFromContext(ctx)
if outbound == nil || !outbound.Target.IsValid() {
return newError("target not specified.")
}
// Destination of the inner request.
destination := outbound.Target
// Outbound server.
var server *protocol.ServerSpec
// Outbound server's destination.
var dest net.Destination
// Connection to the outbound server.
var conn internet.Connection
if err := retry.ExponentialBackoff(5, 100).On(func() error {
server = c.serverPicker.PickServer()
dest = server.Destination()
rawConn, err := dialer.Dial(ctx, dest)
if err != nil {
return err
}
conn = rawConn
return nil
}); err != nil {
return newError("failed to find an available destination").Base(err)
}
defer func() {
if err := conn.Close(); err != nil {
newError("failed to closed connection").Base(err).WriteToLog(session.ExportIDToError(ctx))
}
}()
p := c.policyManager.ForLevel(0)
request := &protocol.RequestHeader{
Version: socks5Version,
Command: protocol.RequestCommandTCP,
Address: destination.Address,
Port: destination.Port,
}
switch c.version {
case Version_SOCKS4:
if request.Address.Family().IsDomain() {
if d, ok := c.dns.(dns.ClientWithIPOption); ok {
d.SetFakeDNSOption(false) // Skip FakeDNS
} else {
newError("DNS client doesn't implement ClientWithIPOption")
}
lookupFunc := c.dns.LookupIP
if lookupIPv4, ok := c.dns.(dns.IPv4Lookup); ok {
lookupFunc = lookupIPv4.LookupIPv4
}
ips, err := lookupFunc(request.Address.Domain())
if err != nil {
return err
} else if len(ips) == 0 {
return dns.ErrEmptyResponse
}
request.Address = net.IPAddress(ips[0])
}
fallthrough
case Version_SOCKS4A:
request.Version = socks4Version
if destination.Network == net.Network_UDP {
return newError("udp is not supported in socks4")
} else if destination.Address.Family().IsIPv6() {
return newError("ipv6 is not supported in socks4")
}
}
if destination.Network == net.Network_UDP {
request.Command = protocol.RequestCommandUDP
}
user := server.PickUser()
if user != nil {
request.User = user
p = c.policyManager.ForLevel(user.Level)
}
if err := conn.SetDeadline(time.Now().Add(p.Timeouts.Handshake)); err != nil {
newError("failed to set deadline for handshake").Base(err).WriteToLog(session.ExportIDToError(ctx))
}
udpRequest, err := ClientHandshake(request, conn, conn)
if err != nil {
return newError("failed to establish connection to server").AtWarning().Base(err)
}
if udpRequest != nil {
if udpRequest.Address == net.AnyIP || udpRequest.Address == net.AnyIPv6 {
udpRequest.Address = dest.Address
}
}
if err := conn.SetDeadline(time.Time{}); err != nil {
newError("failed to clear deadline after handshake").Base(err).WriteToLog(session.ExportIDToError(ctx))
}
ctx, cancel := context.WithCancel(ctx)
timer := signal.CancelAfterInactivity(ctx, cancel, p.Timeouts.ConnectionIdle)
if packetConn, err := packetaddr.ToPacketAddrConn(link, destination); err == nil {
udpConn, err := dialer.Dial(ctx, udpRequest.Destination())
if err != nil {
return newError("failed to create UDP connection").Base(err)
}
defer udpConn.Close()
requestDone := func() error {
protocolWriter := NewUDPWriter(request, udpConn)
return udp.CopyPacketConn(protocolWriter, packetConn, udp.UpdateActivity(timer))
}
responseDone := func() error {
protocolReader := &UDPReader{
reader: udpConn,
}
return udp.CopyPacketConn(packetConn, protocolReader, udp.UpdateActivity(timer))
}
responseDoneAndCloseWriter := task.OnSuccess(responseDone, task.Close(link.Writer))
if err := task.Run(ctx, requestDone, responseDoneAndCloseWriter); err != nil {
return newError("connection ends").Base(err)
}
return nil
}
var requestFunc func() error
var responseFunc func() error
if request.Command == protocol.RequestCommandTCP {
requestFunc = func() error {
defer timer.SetTimeout(p.Timeouts.DownlinkOnly)
return buf.Copy(link.Reader, buf.NewWriter(conn), buf.UpdateActivity(timer))
}
responseFunc = func() error {
defer timer.SetTimeout(p.Timeouts.UplinkOnly)
return buf.Copy(buf.NewReader(conn), link.Writer, buf.UpdateActivity(timer))
}
} else if request.Command == protocol.RequestCommandUDP {
udpConn, err := dialer.Dial(ctx, udpRequest.Destination())
if err != nil {
return newError("failed to create UDP connection").Base(err)
}
defer udpConn.Close()
requestFunc = func() error {
defer timer.SetTimeout(p.Timeouts.DownlinkOnly)
return buf.Copy(link.Reader, &buf.SequentialWriter{Writer: NewUDPWriter(request, udpConn)}, buf.UpdateActivity(timer))
}
responseFunc = func() error {
defer timer.SetTimeout(p.Timeouts.UplinkOnly)
reader := &UDPReader{reader: udpConn}
return buf.Copy(reader, link.Writer, buf.UpdateActivity(timer))
}
}
responseDonePost := task.OnSuccess(responseFunc, task.Close(link.Writer))
if err := task.Run(ctx, requestFunc, responseDonePost); err != nil {
return newError("connection ends").Base(err)
}
return nil
}
func init() {
common.Must(common.RegisterConfig((*ClientConfig)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
return NewClient(ctx, config.(*ClientConfig))
}))
}