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|
package hook
import (
"bufio"
"errors"
"fmt"
"io"
"regexp"
"tunnel/pkg/server/env"
"tunnel/pkg/server/opts"
"tunnel/pkg/server/queue"
)
var addrRe = regexp.MustCompile("^[0-9a-zA-Z-.]+:[0-9]+$")
var errBadHttpResponse = errors.New("bad HTTP response")
type proxyHook struct {
addr string
}
type proxy struct {
addr string
ok chan struct{}
fail chan struct{}
}
func (p *proxy) Send(rq, wq queue.Q) error {
request := fmt.Sprintf("CONNECT %s HTTP/1.0\r\n\r\n", p.addr)
wq <- []byte(request)
select {
case <-p.fail:
return nil
case <-p.ok:
}
return queue.Copy(rq, wq)
}
func parseProxyResponse(s string) error {
var version string
var code int
var desc string
if _, err := fmt.Sscanf(s, "%s %d %s", &version, &code, &desc); err != nil {
return errBadHttpResponse
}
if version != "HTTP/1.0" && version != "HTTP/1.1" {
return errBadHttpResponse
}
if code != 200 {
return fmt.Errorf("connect failed: %d %s", code, desc)
}
return nil
}
func (p *proxy) Recv(rq, wq queue.Q) (err error) {
defer func() {
if err != nil {
close(p.fail)
}
}()
s := bufio.NewScanner(rq.Reader())
var resp bool
for s.Scan() {
line := s.Text()
if !resp {
if err := parseProxyResponse(line); err != nil {
return err
}
resp = true
continue
}
if line == "" {
break
}
}
if err := s.Err(); err != nil {
return err
} else if !resp {
return io.ErrUnexpectedEOF
}
close(p.ok)
return queue.Copy(rq, wq)
}
func (h *proxyHook) Open(env.Env) (interface{}, error) {
p := &proxy{
addr: h.addr,
ok: make(chan struct{}),
fail: make(chan struct{}),
}
return p, nil
}
func newProxyHook(opts opts.Opts, env env.Env) (hook, error) {
h := &proxyHook{}
if addr, ok := opts["addr"]; !ok {
return nil, errors.New("proxy: missing addr")
} else if !addrRe.MatchString(addr) {
return nil, errors.New("proxy: invalid addr")
} else {
h.addr = addr
}
return h, nil
}
func init() {
register("proxy", newProxyHook)
}
|