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mirror of https://github.com/v2fly/v2ray-core.git synced 2024-12-22 18:17:52 -05:00
v2fly/proxy/socks/client.go
2018-10-21 10:27:13 +02:00

155 lines
4.6 KiB
Go

package socks
import (
"context"
"time"
"v2ray.com/core/common/session"
"v2ray.com/core/common/task"
"v2ray.com/core/common/vio"
"v2ray.com/core/features/policy"
"v2ray.com/core"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/net"
"v2ray.com/core/common/protocol"
"v2ray.com/core/common/retry"
"v2ray.com/core/common/signal"
"v2ray.com/core/proxy"
"v2ray.com/core/transport/internet"
)
// Client is a Socks5 client.
type Client struct {
serverPicker protocol.ServerPicker
policyManager policy.Manager
}
// 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)
return &Client{
serverPicker: protocol.NewRoundRobinServerPicker(serverList),
policyManager: v.GetFeature(policy.ManagerType()).(policy.Manager),
}, nil
}
// Process implements proxy.Outbound.Process.
func (c *Client) Process(ctx context.Context, link *vio.Link, dialer proxy.Dialer) error {
outbound := session.OutboundFromContext(ctx)
if outbound == nil || !outbound.Target.IsValid() {
return newError("target not specified.")
}
destination := outbound.Target
var server *protocol.ServerSpec
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,
}
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 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)
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() // nolint: errcheck
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))
}
}
var responseDonePost = task.Single(responseFunc, task.OnSuccess(task.Close(link.Writer)))
if err := task.Run(task.WithContext(ctx), task.Parallel(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))
}))
}