gost_software/obfs4.go
2017-07-23 00:08:25 +08:00

115 lines
2.4 KiB
Go

// obfs4 connection wrappers
package gost
import (
"fmt"
"net"
"net/url"
"git.torproject.org/pluggable-transports/goptlib.git" // package pt
"git.torproject.org/pluggable-transports/obfs4.git/transports/base"
"git.torproject.org/pluggable-transports/obfs4.git/transports/obfs4"
)
// Factories are stored per node since some arguments reside in them.
// For simplicity, c & s variables are packed together.
type obfs4Context struct {
cf base.ClientFactory
cargs interface{} // type obfs4ClientArgs
sf base.ServerFactory
sargs *pt.Args
}
var obfs4Map = make(map[string]obfs4Context)
func (node *ProxyNode) obfs4GetContext() (obfs4Context, error) {
if node.Transport != "obfs4" {
return obfs4Context{}, fmt.Errorf("non-obfs4 node has no obfs4 context")
}
ctx, ok := obfs4Map[node.Addr]
if !ok {
return obfs4Context{}, fmt.Errorf("obfs4 context not inited")
}
return ctx, nil
}
func (node *ProxyNode) Obfs4Init(isServeNode bool) error {
if _, ok := obfs4Map[node.Addr]; ok {
return fmt.Errorf("obfs4 context already inited")
}
t := new(obfs4.Transport)
stateDir := node.values.Get("state-dir")
if stateDir == "" {
stateDir = "."
}
ptArgs := pt.Args(node.values)
if !isServeNode {
cf, err := t.ClientFactory(stateDir)
if err != nil {
return err
}
cargs, err := cf.ParseArgs(&ptArgs)
if err != nil {
return err
}
obfs4Map[node.Addr] = obfs4Context{cf: cf, cargs: cargs}
} else {
sf, err := t.ServerFactory(stateDir, &ptArgs)
if err != nil {
return err
}
sargs := sf.Args()
obfs4Map[node.Addr] = obfs4Context{sf: sf, sargs: sargs}
fmt.Println("[obfs4 server inited]", node.Obfs4ServerURL())
}
return nil
}
func (node *ProxyNode) Obfs4ClientConn(conn net.Conn) (net.Conn, error) {
ctx, err := node.obfs4GetContext()
if err != nil {
return nil, err
}
pseudoDial := func (a, b string) (net.Conn, error) {return conn, nil}
return ctx.cf.Dial("tcp", "", pseudoDial, ctx.cargs)
}
func (node *ProxyNode) Obfs4ServerConn(conn net.Conn) (net.Conn, error) {
ctx, err := node.obfs4GetContext()
if err != nil {
return nil, err
}
return ctx.sf.WrapConn(conn)
}
func (node *ProxyNode) Obfs4ServerURL() string {
ctx, err := node.obfs4GetContext()
if err != nil {
return ""
}
values := (*url.Values)(ctx.sargs)
query := values.Encode()
return fmt.Sprintf(
"%s+%s://%s/?%s", //obfs4-cert=%s&iat-mode=%s",
node.Protocol,
node.Transport,
node.Addr,
query,
)
}