tailscale/net/tshttpproxy/tshttpproxy_synology.go
Maisem Ali eff6a404a6 net/tshttpproxy: use http as the scheme for proxies
Currently we try to use `https://` when we see `https_host`, however
that doesn't work and results in errors like `Received error: fetch
control key: Get "https://controlplane.tailscale.com/key?v=32":
proxyconnect tcp: tls: first record does not look like a TLS handshake`

This indiciates that we are trying to do a HTTPS request to a HTTP
server. Googling suggests that the standard is to use `http` regardless
of `https` or `http` proxy

Updates #4395, #2605

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2022-04-28 10:45:33 -07:00

133 lines
2.4 KiB
Go

// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build linux
// +build linux
package tshttpproxy
import (
"bytes"
"fmt"
"io"
"net"
"net/http"
"net/url"
"os"
"strings"
"sync"
"time"
"tailscale.com/util/lineread"
)
// These vars are overridden for tests.
var (
synologyProxyConfigPath = "/etc/proxy.conf"
openSynologyProxyConf = func() (io.ReadCloser, error) {
return os.Open(synologyProxyConfigPath)
}
)
var cache struct {
sync.Mutex
proxy *url.URL
updated time.Time
}
func synologyProxyFromConfigCached(req *http.Request) (*url.URL, error) {
if req.URL == nil {
return nil, nil
}
cache.Lock()
defer cache.Unlock()
modtime := mtime(synologyProxyConfigPath)
if cache.updated == modtime {
return cache.proxy, nil
}
val, err := synologyProxyFromConfig(req)
cache.proxy = val
cache.updated = modtime
return val, err
}
func synologyProxyFromConfig(req *http.Request) (*url.URL, error) {
r, err := openSynologyProxyConf()
if err != nil {
if os.IsNotExist(err) {
return nil, nil
}
return nil, err
}
defer r.Close()
return parseSynologyConfig(r)
}
func parseSynologyConfig(r io.Reader) (*url.URL, error) {
cfg := map[string]string{}
if err := lineread.Reader(r, func(line []byte) error {
// accept and skip over empty lines
line = bytes.TrimSpace(line)
if len(line) == 0 {
return nil
}
key, value, ok := strings.Cut(string(line), "=")
if !ok {
return fmt.Errorf("missing \"=\" in proxy.conf line: %q", line)
}
cfg[string(key)] = string(value)
return nil
}); err != nil {
return nil, err
}
if cfg["proxy_enabled"] != "yes" {
return nil, nil
}
proxyURL := &url.URL{
Scheme: "http", // regardless of proxy type
}
if cfg["auth_enabled"] == "yes" {
proxyURL.User = url.UserPassword(cfg["proxy_user"], cfg["proxy_pwd"])
}
host, port := cfg["https_host"], cfg["https_port"]
if host == "" {
host, port = cfg["http_host"], cfg["http_port"]
}
if host == "" {
return nil, nil
}
if port != "" {
proxyURL.Host = net.JoinHostPort(host, port)
} else {
proxyURL.Host = host
}
return proxyURL, nil
}
// mtime stat's path and returns its modification time. If path does not exist,
// it returns the unix epoch.
func mtime(path string) time.Time {
fi, err := os.Stat(path)
if err != nil {
return time.Unix(0, 0)
}
return fi.ModTime()
}