mirror of
https://github.com/tailscale/tailscale.git
synced 2024-12-04 23:45:34 +00:00
ec036b3561
Fixes #3332 Change-Id: Ie45efb448e5508c3ece48dd1d8d7e9a39e2e9dc1 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
644 lines
18 KiB
Go
644 lines
18 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package logpolicy manages the creation or reuse of logtail loggers,
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// caching collection instance state on disk for use on future runs of
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// programs on the same machine.
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package logpolicy
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import (
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"bytes"
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"context"
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"crypto/tls"
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"encoding/json"
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"fmt"
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"io/ioutil"
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"log"
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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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"os/exec"
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"path/filepath"
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"runtime"
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"strconv"
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"strings"
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"sync"
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"time"
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"golang.org/x/term"
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"tailscale.com/atomicfile"
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"tailscale.com/logtail"
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"tailscale.com/logtail/filch"
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"tailscale.com/net/dnscache"
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"tailscale.com/net/dnsfallback"
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"tailscale.com/net/netknob"
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"tailscale.com/net/netns"
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"tailscale.com/net/tlsdial"
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"tailscale.com/net/tshttpproxy"
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"tailscale.com/paths"
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"tailscale.com/smallzstd"
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"tailscale.com/types/logger"
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"tailscale.com/util/clientmetric"
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"tailscale.com/util/racebuild"
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"tailscale.com/util/winutil"
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"tailscale.com/version"
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)
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var getLogTargetOnce struct {
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sync.Once
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v string // URL of logs server, or empty for default
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}
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func getLogTarget() string {
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getLogTargetOnce.Do(func() {
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if val, ok := os.LookupEnv("TS_LOG_TARGET"); ok {
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getLogTargetOnce.v = val
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} else {
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if runtime.GOOS == "windows" {
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getLogTargetOnce.v = winutil.GetRegString("LogTarget", "")
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}
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}
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})
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return getLogTargetOnce.v
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}
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// Config represents an instance of logs in a collection.
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type Config struct {
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Collection string
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PrivateID logtail.PrivateID
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PublicID logtail.PublicID
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}
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// Policy is a logger and its public ID.
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type Policy struct {
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// Logtail is the logger.
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Logtail *logtail.Logger
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// PublicID is the logger's instance identifier.
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PublicID logtail.PublicID
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}
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// ToBytes returns the JSON representation of c.
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func (c *Config) ToBytes() []byte {
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data, err := json.MarshalIndent(c, "", "\t")
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if err != nil {
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log.Fatalf("logpolicy.Config marshal: %v", err)
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}
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return data
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}
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// Save writes the JSON representation of c to stateFile.
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func (c *Config) save(stateFile string) error {
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c.PublicID = c.PrivateID.Public()
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if err := os.MkdirAll(filepath.Dir(stateFile), 0750); err != nil {
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return err
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}
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data := c.ToBytes()
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if err := atomicfile.WriteFile(stateFile, data, 0600); err != nil {
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return err
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}
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return nil
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}
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// ConfigFromBytes parses a a Config from its JSON encoding.
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func ConfigFromBytes(jsonEnc []byte) (*Config, error) {
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c := &Config{}
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if err := json.Unmarshal(jsonEnc, c); err != nil {
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return nil, err
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}
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return c, nil
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}
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// stderrWriter is an io.Writer that always writes to the latest
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// os.Stderr, even if os.Stderr changes during the lifetime of the
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// stderrWriter value.
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type stderrWriter struct{}
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func (stderrWriter) Write(buf []byte) (int, error) {
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return os.Stderr.Write(buf)
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}
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type logWriter struct {
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logger *log.Logger
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}
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func (l logWriter) Write(buf []byte) (int, error) {
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l.logger.Printf("%s", buf)
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return len(buf), nil
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}
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// logsDir returns the directory to use for log configuration and
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// buffer storage.
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func logsDir(logf logger.Logf) string {
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if d := os.Getenv("TS_LOGS_DIR"); d != "" {
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fi, err := os.Stat(d)
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if err == nil && fi.IsDir() {
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return d
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}
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}
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switch runtime.GOOS {
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case "windows":
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if version.CmdName() == "tailscaled" {
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// In the common case, when tailscaled is run as the Local System (as a service),
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// we want to use %ProgramData% (C:\ProgramData\Tailscale), aside the
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// system state config with the machine key, etc. But if that directory's
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// not accessible, then it's probably because the user is running tailscaled
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// as a regular user (perhaps in userspace-networking/SOCK5 mode) and we should
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// just use the %LocalAppData% instead. In a user context, %LocalAppData% isn't
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// subject to random deletions from Windows system updates.
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dir := filepath.Join(os.Getenv("ProgramData"), "Tailscale")
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if winProgramDataAccessible(dir) {
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logf("logpolicy: using dir %v", dir)
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return dir
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}
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}
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dir := filepath.Join(os.Getenv("LocalAppData"), "Tailscale")
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logf("logpolicy: using LocalAppData dir %v", dir)
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return dir
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case "linux":
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// STATE_DIRECTORY is set by systemd 240+ but we support older
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// systems-d. For example, Ubuntu 18.04 (Bionic Beaver) is 237.
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systemdStateDir := os.Getenv("STATE_DIRECTORY")
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if systemdStateDir != "" {
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logf("logpolicy: using $STATE_DIRECTORY, %q", systemdStateDir)
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return systemdStateDir
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}
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}
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// Default to e.g. /var/lib/tailscale or /var/db/tailscale on Unix.
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if d := paths.DefaultTailscaledStateFile(); d != "" {
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d = filepath.Dir(d) // directory of e.g. "/var/lib/tailscale/tailscaled.state"
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if err := os.MkdirAll(d, 0700); err == nil {
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logf("logpolicy: using system state directory %q", d)
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return d
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}
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}
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cacheDir, err := os.UserCacheDir()
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if err == nil {
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d := filepath.Join(cacheDir, "Tailscale")
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logf("logpolicy: using UserCacheDir, %q", d)
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return d
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}
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// Use the current working directory, unless we're being run by a
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// service manager that sets it to /.
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wd, err := os.Getwd()
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if err == nil && wd != "/" {
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logf("logpolicy: using current directory, %q", wd)
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return wd
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}
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// No idea where to put stuff. Try to create a temp dir. It'll
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// mean we might lose some logs and rotate through log IDs, but
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// it's something.
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tmp, err := ioutil.TempDir("", "tailscaled-log-*")
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if err != nil {
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panic("no safe place found to store log state")
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}
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logf("logpolicy: using temp directory, %q", tmp)
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return tmp
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}
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// runningUnderSystemd reports whether we're running under systemd.
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func runningUnderSystemd() bool {
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if runtime.GOOS == "linux" && os.Getppid() == 1 {
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slurp, _ := ioutil.ReadFile("/proc/1/stat")
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return bytes.HasPrefix(slurp, []byte("1 (systemd) "))
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}
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return false
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}
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func redirectStderrToLogPanics() bool {
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return runningUnderSystemd() || os.Getenv("TS_PLEASE_PANIC") != ""
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}
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// winProgramDataAccessible reports whether the directory (assumed to
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// be a Windows %ProgramData% directory) is accessible to the current
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// process. It's created if needed.
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func winProgramDataAccessible(dir string) bool {
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if err := os.MkdirAll(dir, 0700); err != nil {
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// TODO: windows ACLs
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return false
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}
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// The C:\ProgramData\Tailscale directory should be locked down
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// by with ACLs to only be readable by the local system so a
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// regular user shouldn't be able to do this operation:
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if _, err := os.ReadDir(dir); err != nil {
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return false
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}
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return true
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}
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// tryFixLogStateLocation is a temporary fixup for
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// https://github.com/tailscale/tailscale/issues/247 . We accidentally
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// wrote logging state files to /, and then later to $CACHE_DIRECTORY
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// (which is incorrect because the log ID is not reconstructible if
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// deleted - it's state, not cache data).
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//
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// If log state for cmdname exists in / or $CACHE_DIRECTORY, and no
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// log state for that command exists in dir, then the log state is
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// moved from wherever it does exist, into dir. Leftover logs state
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// in / and $CACHE_DIRECTORY is deleted.
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func tryFixLogStateLocation(dir, cmdname string) {
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switch runtime.GOOS {
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case "linux", "freebsd", "openbsd":
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// These are the OSes where we might have written stuff into
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// root. Others use different logic to find the logs storage
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// dir.
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default:
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return
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}
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if cmdname == "" {
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log.Printf("[unexpected] no cmdname given to tryFixLogStateLocation, please file a bug at https://github.com/tailscale/tailscale")
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return
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}
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if dir == "/" {
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// Trying to store things in / still. That's a bug, but don't
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// abort hard.
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log.Printf("[unexpected] storing logging config in /, please file a bug at https://github.com/tailscale/tailscale")
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return
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}
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if os.Getuid() != 0 {
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// Only root could have written log configs to weird places.
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return
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}
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// We stored logs in 2 incorrect places: either /, or CACHE_DIR
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// (aka /var/cache/tailscale). We want to move files into the
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// provided dir, preferring those in CACHE_DIR over those in / if
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// both exist. If files already exist in dir, don't
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// overwrite. Finally, once we've maybe moved files around, we
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// want to delete leftovers in / and CACHE_DIR, to clean up after
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// our past selves.
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files := []string{
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fmt.Sprintf("%s.log.conf", cmdname),
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fmt.Sprintf("%s.log1.txt", cmdname),
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fmt.Sprintf("%s.log2.txt", cmdname),
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}
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// checks if any of the files above exist in d.
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checkExists := func(d string) (bool, error) {
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for _, file := range files {
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p := filepath.Join(d, file)
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_, err := os.Stat(p)
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if os.IsNotExist(err) {
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continue
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} else if err != nil {
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return false, fmt.Errorf("stat %q: %w", p, err)
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}
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return true, nil
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}
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return false, nil
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}
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// move files from d into dir, if they exist.
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moveFiles := func(d string) error {
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for _, file := range files {
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src := filepath.Join(d, file)
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_, err := os.Stat(src)
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if os.IsNotExist(err) {
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continue
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} else if err != nil {
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return fmt.Errorf("stat %q: %v", src, err)
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}
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dst := filepath.Join(dir, file)
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bs, err := exec.Command("mv", src, dst).CombinedOutput()
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if err != nil {
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return fmt.Errorf("mv %q %q: %v (%s)", src, dst, err, bs)
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}
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}
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return nil
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}
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existsInRoot, err := checkExists("/")
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if err != nil {
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log.Printf("checking for configs in /: %v", err)
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return
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}
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existsInCache := false
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cacheDir := os.Getenv("CACHE_DIRECTORY")
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if cacheDir != "" {
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existsInCache, err = checkExists("/var/cache/tailscale")
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if err != nil {
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log.Printf("checking for configs in %s: %v", cacheDir, err)
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}
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}
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existsInDest, err := checkExists(dir)
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if err != nil {
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log.Printf("checking for configs in %s: %v", dir, err)
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return
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}
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switch {
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case !existsInRoot && !existsInCache:
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// No leftover files, nothing to do.
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return
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case existsInDest:
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// Already have "canonical" configs, just delete any remnants
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// (below).
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case existsInCache:
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// CACHE_DIRECTORY takes precedence over /, move files from
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// there.
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if err := moveFiles(cacheDir); err != nil {
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log.Print(err)
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return
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}
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case existsInRoot:
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// Files from root is better than nothing.
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if err := moveFiles("/"); err != nil {
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log.Print(err)
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return
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}
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}
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// If moving succeeded, or we didn't need to move files, try to
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// delete any leftover files, but it's okay if we can't delete
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// them for some reason.
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dirs := []string{}
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if existsInCache {
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dirs = append(dirs, cacheDir)
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}
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if existsInRoot {
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dirs = append(dirs, "/")
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}
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for _, d := range dirs {
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for _, file := range files {
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p := filepath.Join(d, file)
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_, err := os.Stat(p)
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if os.IsNotExist(err) {
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continue
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} else if err != nil {
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log.Printf("stat %q: %v", p, err)
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return
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}
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if err := os.Remove(p); err != nil {
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log.Printf("rm %q: %v", p, err)
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}
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}
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}
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}
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// New returns a new log policy (a logger and its instance ID) for a
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// given collection name.
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func New(collection string) *Policy {
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var lflags int
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if term.IsTerminal(2) || runtime.GOOS == "windows" {
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lflags = 0
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} else {
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lflags = log.LstdFlags
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}
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if v, _ := strconv.ParseBool(os.Getenv("TS_DEBUG_LOG_TIME")); v {
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lflags = log.LstdFlags | log.Lmicroseconds
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}
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if runningUnderSystemd() {
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// If journalctl is going to prepend its own timestamp
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// anyway, no need to add one.
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lflags = 0
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}
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console := log.New(stderrWriter{}, "", lflags)
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var earlyErrBuf bytes.Buffer
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earlyLogf := func(format string, a ...interface{}) {
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fmt.Fprintf(&earlyErrBuf, format, a...)
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earlyErrBuf.WriteByte('\n')
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}
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dir := logsDir(earlyLogf)
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cmdName := version.CmdName()
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tryFixLogStateLocation(dir, cmdName)
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cfgPath := filepath.Join(dir, fmt.Sprintf("%s.log.conf", cmdName))
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if runtime.GOOS == "windows" {
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switch cmdName {
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case "tailscaled":
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// Tailscale 1.14 and before stored state under %LocalAppData%
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// (usually "C:\WINDOWS\system32\config\systemprofile\AppData\Local"
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// when tailscaled.exe is running as a non-user system service).
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// However it is frequently cleared for almost any reason: Windows
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// updates, System Restore, even various System Cleaner utilities.
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//
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// The Windows service previously ran as tailscale-ipn.exe, so
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// machines which ran very old versions might still have their
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// log conf named %LocalAppData%\tailscale-ipn.log.conf
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//
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// Machines which started using Tailscale more recently will have
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// %LocalAppData%\tailscaled.log.conf
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//
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// Attempt to migrate the log conf to C:\ProgramData\Tailscale
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oldDir := filepath.Join(os.Getenv("LocalAppData"), "Tailscale")
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oldPath := filepath.Join(oldDir, "tailscaled.log.conf")
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if fi, err := os.Stat(oldPath); err != nil || !fi.Mode().IsRegular() {
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// *Only* if tailscaled.log.conf does not exist,
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// check for tailscale-ipn.log.conf
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oldPathOldCmd := filepath.Join(oldDir, "tailscale-ipn.log.conf")
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if fi, err := os.Stat(oldPathOldCmd); err == nil && fi.Mode().IsRegular() {
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oldPath = oldPathOldCmd
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}
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}
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cfgPath = paths.TryConfigFileMigration(earlyLogf, oldPath, cfgPath)
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case "tailscale-ipn":
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for _, oldBase := range []string{"wg64.log.conf", "wg32.log.conf"} {
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oldConf := filepath.Join(dir, oldBase)
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if fi, err := os.Stat(oldConf); err == nil && fi.Mode().IsRegular() {
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cfgPath = paths.TryConfigFileMigration(earlyLogf, oldConf, cfgPath)
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break
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}
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}
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}
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}
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var oldc *Config
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data, err := ioutil.ReadFile(cfgPath)
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if err != nil {
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earlyLogf("logpolicy.Read %v: %v", cfgPath, err)
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oldc = &Config{}
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oldc.Collection = collection
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} else {
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oldc, err = ConfigFromBytes(data)
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if err != nil {
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earlyLogf("logpolicy.Config unmarshal: %v", err)
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oldc = &Config{}
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}
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}
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newc := *oldc
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if newc.Collection != collection {
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log.Printf("logpolicy.Config: config collection %q does not match %q", newc.Collection, collection)
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// We picked up an incompatible config file.
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// Regenerate the private ID.
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newc.PrivateID = logtail.PrivateID{}
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newc.Collection = collection
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}
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if newc.PrivateID.IsZero() {
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newc.PrivateID, err = logtail.NewPrivateID()
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if err != nil {
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log.Fatalf("logpolicy: NewPrivateID() should never fail")
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}
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}
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newc.PublicID = newc.PrivateID.Public()
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if newc != *oldc {
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if err := newc.save(cfgPath); err != nil {
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earlyLogf("logpolicy.Config.Save: %v", err)
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}
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}
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c := logtail.Config{
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Collection: newc.Collection,
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PrivateID: newc.PrivateID,
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Stderr: logWriter{console},
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NewZstdEncoder: func() logtail.Encoder {
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w, err := smallzstd.NewEncoder(nil)
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if err != nil {
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panic(err)
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}
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return w
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},
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HTTPC: &http.Client{Transport: newLogtailTransport(logtail.DefaultHost)},
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}
|
|
if collection == logtail.CollectionNode {
|
|
c.MetricsDelta = clientmetric.EncodeLogTailMetricsDelta
|
|
}
|
|
|
|
if val := getLogTarget(); val != "" {
|
|
log.Println("You have enabled a non-default log target. Doing without being told to by Tailscale staff or your network administrator will make getting support difficult.")
|
|
c.BaseURL = val
|
|
u, _ := url.Parse(val)
|
|
c.HTTPC = &http.Client{Transport: newLogtailTransport(u.Host)}
|
|
}
|
|
|
|
filchBuf, filchErr := filch.New(filepath.Join(dir, cmdName), filch.Options{
|
|
ReplaceStderr: redirectStderrToLogPanics(),
|
|
})
|
|
if filchBuf != nil {
|
|
c.Buffer = filchBuf
|
|
if filchBuf.OrigStderr != nil {
|
|
c.Stderr = filchBuf.OrigStderr
|
|
}
|
|
}
|
|
lw := logtail.NewLogger(c, log.Printf)
|
|
log.SetFlags(0) // other logflags are set on console, not here
|
|
log.SetOutput(lw)
|
|
|
|
log.Printf("Program starting: v%v, Go %v: %#v",
|
|
version.Long,
|
|
goVersion(),
|
|
os.Args)
|
|
log.Printf("LogID: %v", newc.PublicID)
|
|
if filchErr != nil {
|
|
log.Printf("filch failed: %v", filchErr)
|
|
}
|
|
if earlyErrBuf.Len() != 0 {
|
|
log.Printf("%s", earlyErrBuf.Bytes())
|
|
}
|
|
|
|
return &Policy{
|
|
Logtail: lw,
|
|
PublicID: newc.PublicID,
|
|
}
|
|
}
|
|
|
|
// SetVerbosityLevel controls the verbosity level that should be
|
|
// written to stderr. 0 is the default (not verbose). Levels 1 or higher
|
|
// are increasingly verbose.
|
|
//
|
|
// It should not be changed concurrently with log writes.
|
|
func (p *Policy) SetVerbosityLevel(level int) {
|
|
p.Logtail.SetVerbosityLevel(level)
|
|
}
|
|
|
|
// Close immediately shuts down the logger.
|
|
func (p *Policy) Close() {
|
|
ctx, cancel := context.WithCancel(context.Background())
|
|
cancel()
|
|
p.Shutdown(ctx)
|
|
}
|
|
|
|
// Shutdown gracefully shuts down the logger, finishing any current
|
|
// log upload if it can be done before ctx is canceled.
|
|
func (p *Policy) Shutdown(ctx context.Context) error {
|
|
if p.Logtail != nil {
|
|
log.Printf("flushing log.")
|
|
return p.Logtail.Shutdown(ctx)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// newLogtailTransport returns the HTTP Transport we use for uploading
|
|
// logs to the given host name.
|
|
func newLogtailTransport(host string) *http.Transport {
|
|
// Start with a copy of http.DefaultTransport and tweak it a bit.
|
|
tr := http.DefaultTransport.(*http.Transport).Clone()
|
|
|
|
tr.Proxy = tshttpproxy.ProxyFromEnvironment
|
|
tshttpproxy.SetTransportGetProxyConnectHeader(tr)
|
|
|
|
// We do our own zstd compression on uploads, and responses never contain any payload,
|
|
// so don't send "Accept-Encoding: gzip" to save a few bytes on the wire, since there
|
|
// will never be any body to decompress:
|
|
tr.DisableCompression = true
|
|
|
|
// Log whenever we dial:
|
|
tr.DialContext = func(ctx context.Context, netw, addr string) (net.Conn, error) {
|
|
nd := netns.FromDialer(&net.Dialer{
|
|
Timeout: 30 * time.Second,
|
|
KeepAlive: netknob.PlatformTCPKeepAlive(),
|
|
})
|
|
t0 := time.Now()
|
|
c, err := nd.DialContext(ctx, netw, addr)
|
|
d := time.Since(t0).Round(time.Millisecond)
|
|
if err == nil {
|
|
log.Printf("logtail: dialed %q in %v", addr, d)
|
|
return c, nil
|
|
}
|
|
|
|
// If we failed to dial, try again with bootstrap DNS.
|
|
log.Printf("logtail: dial %q failed: %v (in %v), trying bootstrap...", addr, err, d)
|
|
dnsCache := &dnscache.Resolver{
|
|
Forward: dnscache.Get().Forward, // use default cache's forwarder
|
|
UseLastGood: true,
|
|
LookupIPFallback: dnsfallback.Lookup,
|
|
}
|
|
dialer := dnscache.Dialer(nd.DialContext, dnsCache)
|
|
c, err = dialer(ctx, netw, addr)
|
|
if err == nil {
|
|
log.Printf("logtail: bootstrap dial succeeded")
|
|
}
|
|
return c, err
|
|
}
|
|
|
|
// We're contacting exactly 1 hostname, so the default's 100
|
|
// max idle conns is very high for our needs. Even 2 is
|
|
// probably double what we need:
|
|
tr.MaxIdleConns = 2
|
|
|
|
// Provide knob to force HTTP/1 for log uploads.
|
|
// TODO(bradfitz): remove this debug knob once we've decided
|
|
// to upload via HTTP/1 or HTTP/2 (probably HTTP/1). Or we might just enforce
|
|
// it server-side.
|
|
if h1, _ := strconv.ParseBool(os.Getenv("TS_DEBUG_FORCE_H1_LOGS")); h1 {
|
|
tr.TLSClientConfig = nil // DefaultTransport's was already initialized w/ h2
|
|
tr.ForceAttemptHTTP2 = false
|
|
tr.TLSNextProto = map[string]func(authority string, c *tls.Conn) http.RoundTripper{}
|
|
}
|
|
|
|
tr.TLSClientConfig = tlsdial.Config(host, tr.TLSClientConfig)
|
|
|
|
return tr
|
|
}
|
|
|
|
func goVersion() string {
|
|
v := strings.TrimPrefix(runtime.Version(), "go")
|
|
if racebuild.On {
|
|
return v + "-race"
|
|
}
|
|
return v
|
|
}
|