Update dependencies

vendor/tailscale.com/net/tshttpproxy/tshttpproxy_synology.go

@@ -0,0 +1,140 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go: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
+	httpProxy  *url.URL
+	httpsProxy *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()
+
+	var err error
+	modtime := mtime(synologyProxyConfigPath)
+
+	if modtime != cache.updated {
+		cache.httpProxy, cache.httpsProxy, err = synologyProxiesFromConfig()
+		cache.updated = modtime
+	}
+
+	if req.URL.Scheme == "https" {
+		return cache.httpsProxy, err
+	}
+	return cache.httpProxy, err
+}
+
+func synologyProxiesFromConfig() (*url.URL, *url.URL, error) {
+	r, err := openSynologyProxyConf()
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil, nil
+		}
+		return nil, nil, err
+	}
+	defer r.Close()
+
+	return parseSynologyConfig(r)
+}
+
+// parseSynologyConfig parses the Synology proxy configuration, and returns any
+// http proxy, and any https proxy respectively, or an error if parsing fails.
+func parseSynologyConfig(r io.Reader) (*url.URL, *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, nil, err
+	}
+
+	if cfg["proxy_enabled"] != "yes" {
+		return nil, nil, nil
+	}
+
+	httpProxyURL := new(url.URL)
+	httpsProxyURL := new(url.URL)
+	if cfg["auth_enabled"] == "yes" {
+		httpProxyURL.User = url.UserPassword(cfg["proxy_user"], cfg["proxy_pwd"])
+		httpsProxyURL.User = url.UserPassword(cfg["proxy_user"], cfg["proxy_pwd"])
+	}
+
+	// As far as we are aware, synology does not support tls proxies.
+	httpProxyURL.Scheme = "http"
+	httpsProxyURL.Scheme = "http"
+
+	httpsProxyURL = addHostPort(httpsProxyURL, cfg["https_host"], cfg["https_port"])
+	httpProxyURL = addHostPort(httpProxyURL, cfg["http_host"], cfg["http_port"])
+
+	return httpProxyURL, httpsProxyURL, nil
+}
+
+// addHostPort adds to u the given host and port and returns the updated url, or
+// if host is empty, it returns nil.
+func addHostPort(u *url.URL, host, port string) *url.URL {
+	if host == "" {
+		return nil
+	}
+
+	if port == "" {
+		u.Host = host
+	} else {
+		u.Host = net.JoinHostPort(host, port)
+	}
+	return u
+}
+
+// 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()
+}