142 lines
3.0 KiB
Go
142 lines
3.0 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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//go:build linux
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package tshttpproxy
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import (
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"bytes"
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"fmt"
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"io"
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"net"
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"net/http"
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"net/url"
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"os"
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"strings"
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"sync"
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"time"
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"tailscale.com/util/lineiter"
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)
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// These vars are overridden for tests.
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var (
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synologyProxyConfigPath = "/etc/proxy.conf"
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openSynologyProxyConf = func() (io.ReadCloser, error) {
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return os.Open(synologyProxyConfigPath)
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}
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)
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var cache struct {
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sync.Mutex
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httpProxy *url.URL
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httpsProxy *url.URL
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updated time.Time
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}
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func synologyProxyFromConfigCached(req *http.Request) (*url.URL, error) {
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if req.URL == nil {
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return nil, nil
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}
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cache.Lock()
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defer cache.Unlock()
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var err error
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modtime := mtime(synologyProxyConfigPath)
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if modtime != cache.updated {
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cache.httpProxy, cache.httpsProxy, err = synologyProxiesFromConfig()
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cache.updated = modtime
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}
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if req.URL.Scheme == "https" {
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return cache.httpsProxy, err
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}
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return cache.httpProxy, err
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}
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func synologyProxiesFromConfig() (*url.URL, *url.URL, error) {
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r, err := openSynologyProxyConf()
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if err != nil {
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if os.IsNotExist(err) {
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return nil, nil, nil
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}
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return nil, nil, err
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}
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defer r.Close()
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return parseSynologyConfig(r)
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}
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// parseSynologyConfig parses the Synology proxy configuration, and returns any
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// http proxy, and any https proxy respectively, or an error if parsing fails.
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func parseSynologyConfig(r io.Reader) (*url.URL, *url.URL, error) {
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cfg := map[string]string{}
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for lr := range lineiter.Reader(r) {
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line, err := lr.Value()
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if err != nil {
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return nil, nil, err
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}
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// accept and skip over empty lines
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line = bytes.TrimSpace(line)
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if len(line) == 0 {
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continue
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}
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key, value, ok := strings.Cut(string(line), "=")
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if !ok {
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return nil, nil, fmt.Errorf("missing \"=\" in proxy.conf line: %q", line)
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}
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cfg[string(key)] = string(value)
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}
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if cfg["proxy_enabled"] != "yes" {
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return nil, nil, nil
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}
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httpProxyURL := new(url.URL)
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httpsProxyURL := new(url.URL)
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if cfg["auth_enabled"] == "yes" {
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httpProxyURL.User = url.UserPassword(cfg["proxy_user"], cfg["proxy_pwd"])
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httpsProxyURL.User = url.UserPassword(cfg["proxy_user"], cfg["proxy_pwd"])
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}
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// As far as we are aware, synology does not support tls proxies.
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httpProxyURL.Scheme = "http"
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httpsProxyURL.Scheme = "http"
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httpsProxyURL = addHostPort(httpsProxyURL, cfg["https_host"], cfg["https_port"])
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httpProxyURL = addHostPort(httpProxyURL, cfg["http_host"], cfg["http_port"])
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return httpProxyURL, httpsProxyURL, nil
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}
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// addHostPort adds to u the given host and port and returns the updated url, or
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// if host is empty, it returns nil.
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func addHostPort(u *url.URL, host, port string) *url.URL {
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if host == "" {
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return nil
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}
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if port == "" {
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u.Host = host
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} else {
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u.Host = net.JoinHostPort(host, port)
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}
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return u
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}
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// mtime stat's path and returns its modification time. If path does not exist,
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// it returns the unix epoch.
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func mtime(path string) time.Time {
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fi, err := os.Stat(path)
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if err != nil {
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return time.Unix(0, 0)
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}
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return fi.ModTime()
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}
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