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freedom.go
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freedom.go
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package freedom
//go:generate errorgen
import (
"context"
"time"
"v2ray.com/core"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/dice"
"v2ray.com/core/common/net"
"v2ray.com/core/common/retry"
"v2ray.com/core/common/session"
"v2ray.com/core/common/signal"
"v2ray.com/core/common/task"
"v2ray.com/core/features/dns"
"v2ray.com/core/features/policy"
"v2ray.com/core/transport"
"v2ray.com/core/transport/internet"
)
func init() {
common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
h := new(Handler)
if err := core.RequireFeatures(ctx, func(pm policy.Manager, d dns.Client) error {
return h.Init(config.(*Config), pm, d)
}); err != nil {
return nil, err
}
return h, nil
}))
}
// Handler handles Freedom connections.
type Handler struct {
policyManager policy.Manager
dns dns.Client
config Config
}
// Init initializes the Handler with necessary parameters.
func (h *Handler) Init(config *Config, pm policy.Manager, d dns.Client) error {
h.config = *config
h.policyManager = pm
h.dns = d
return nil
}
func (h *Handler) policy() policy.Session {
p := h.policyManager.ForLevel(h.config.UserLevel)
if h.config.Timeout > 0 && h.config.UserLevel == 0 {
p.Timeouts.ConnectionIdle = time.Duration(h.config.Timeout) * time.Second
}
return p
}
func (h *Handler) resolveIP(ctx context.Context, domain string, localAddr net.Address) net.Address {
var lookupFunc func(string) ([]net.IP, error) = h.dns.LookupIP
if h.config.DomainStrategy == Config_USE_IP4 || (localAddr != nil && localAddr.Family().IsIPv4()) {
if lookupIPv4, ok := h.dns.(dns.IPv4Lookup); ok {
lookupFunc = lookupIPv4.LookupIPv4
}
} else if h.config.DomainStrategy == Config_USE_IP6 || (localAddr != nil && localAddr.Family().IsIPv6()) {
if lookupIPv6, ok := h.dns.(dns.IPv6Lookup); ok {
lookupFunc = lookupIPv6.LookupIPv6
}
}
ips, err := lookupFunc(domain)
if err != nil {
newError("failed to get IP address for domain ", domain).Base(err).WriteToLog(session.ExportIDToError(ctx))
}
if len(ips) == 0 {
return nil
}
return net.IPAddress(ips[dice.Roll(len(ips))])
}
func isValidAddress(addr *net.IPOrDomain) bool {
if addr == nil {
return false
}
a := addr.AsAddress()
return a != net.AnyIP
}
// Process implements proxy.Outbound.
func (h *Handler) 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 := outbound.Target
if h.config.DestinationOverride != nil {
server := h.config.DestinationOverride.Server
if isValidAddress(server.Address) {
destination.Address = server.Address.AsAddress()
}
if server.Port != 0 {
destination.Port = net.Port(server.Port)
}
}
newError("opening connection to ", destination).WriteToLog(session.ExportIDToError(ctx))
input := link.Reader
output := link.Writer
var conn internet.Connection
err := retry.ExponentialBackoff(5, 100).On(func() error {
dialDest := destination
if h.config.useIP() && dialDest.Address.Family().IsDomain() {
ip := h.resolveIP(ctx, dialDest.Address.Domain(), dialer.Address())
if ip != nil {
dialDest = net.Destination{
Network: dialDest.Network,
Address: ip,
Port: dialDest.Port,
}
newError("dialing to to ", dialDest).WriteToLog(session.ExportIDToError(ctx))
}
}
rawConn, err := dialer.Dial(ctx, dialDest)
if err != nil {
return err
}
conn = rawConn
return nil
})
if err != nil {
return newError("failed to open connection to ", destination).Base(err)
}
defer conn.Close() // nolint: errcheck
plcy := h.policy()
ctx, cancel := context.WithCancel(ctx)
timer := signal.CancelAfterInactivity(ctx, cancel, plcy.Timeouts.ConnectionIdle)
requestDone := func() error {
defer timer.SetTimeout(plcy.Timeouts.DownlinkOnly)
var writer buf.Writer
if destination.Network == net.Network_TCP {
writer = buf.NewWriter(conn)
} else {
writer = &buf.SequentialWriter{Writer: conn}
}
if err := buf.Copy(input, writer, buf.UpdateActivity(timer)); err != nil {
return newError("failed to process request").Base(err)
}
return nil
}
responseDone := func() error {
defer timer.SetTimeout(plcy.Timeouts.UplinkOnly)
var reader buf.Reader
if destination.Network == net.Network_TCP {
reader = buf.NewReader(conn)
} else {
reader = &buf.PacketReader{Reader: conn}
}
if err := buf.Copy(reader, output, buf.UpdateActivity(timer)); err != nil {
return newError("failed to process response").Base(err)
}
return nil
}
if err := task.Run(ctx, requestDone, task.OnSuccess(responseDone, task.Close(output))); err != nil {
return newError("connection ends").Base(err)
}
return nil
}