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tailscale/wgengine/wglog/wglog.go

104 lines
3.4 KiB
Go

// Copyright (c) 2020 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.
// Package wglog contains logging helpers for wireguard-go.
package wglog
import (
"encoding/base64"
"fmt"
"strings"
"sync/atomic"
"github.com/tailscale/wireguard-go/device"
"tailscale.com/types/logger"
"tailscale.com/types/wgkey"
"tailscale.com/wgengine/wgcfg"
)
// A Logger is a wireguard-go log wrapper that cleans up and rewrites log lines.
// It can be modified at run time to adjust to new wireguard-go configurations.
type Logger struct {
DeviceLogger *device.Logger
replace atomic.Value // of map[string]string
}
// NewLogger creates a new logger for use with wireguard-go.
// This logger silences repetitive/unhelpful noisy log lines
// and rewrites peer keys from wireguard-go into Tailscale format.
func NewLogger(logf logger.Logf) *Logger {
ret := new(Logger)
wrapper := func(format string, args ...interface{}) {
if strings.Contains(format, "Routine:") && !strings.Contains(format, "receive incoming") {
// wireguard-go logs as it starts and stops routines.
// Drop those; there are a lot of them, and they're just noise.
return
}
if strings.Contains(format, "Failed to send data packet") {
// Drop. See https://github.com/tailscale/tailscale/issues/1239.
return
}
if strings.Contains(format, "Interface up requested") || strings.Contains(format, "Interface down requested") {
// Drop. Logs 1/s constantly while the tun device is open.
// See https://github.com/tailscale/tailscale/issues/1388.
return
}
replace, _ := ret.replace.Load().(map[string]string)
if replace == nil {
// No replacements specified; log as originally planned.
logf(format, args...)
return
}
// Duplicate the args slice so that we can modify it.
// This is not always required, but the code required to avoid it is not worth the complexity.
newargs := make([]interface{}, len(args))
copy(newargs, args)
for i, arg := range newargs {
// We want to replace *device.Peer args with the Tailscale-formatted version of themselves.
// Using *device.Peer directly makes this hard to test, so we string any fmt.Stringers,
// and if the string ends up looking exactly like a known Peer, we replace it.
// This is slightly imprecise, in that we don't check the formatting verb. Oh well.
s, ok := arg.(fmt.Stringer)
if !ok {
continue
}
wgStr := s.String()
tsStr, ok := replace[wgStr]
if !ok {
continue
}
newargs[i] = tsStr
}
logf(format, newargs...)
}
ret.DeviceLogger = &device.Logger{
Verbosef: logger.WithPrefix(wrapper, "[v2] "),
Errorf: wrapper,
}
return ret
}
// SetPeers adjusts x to rewrite the peer public keys found in peers.
// SetPeers is safe for concurrent use.
func (x *Logger) SetPeers(peers []wgcfg.Peer) {
// Construct a new peer public key log rewriter.
replace := make(map[string]string)
for _, peer := range peers {
old := "peer(" + wireguardGoString(peer.PublicKey) + ")"
new := peer.PublicKey.ShortString()
replace[old] = new
}
x.replace.Store(replace)
}
// wireguardGoString prints p in the same format used by wireguard-go.
func wireguardGoString(k wgkey.Key) string {
base64Key := base64.StdEncoding.EncodeToString(k[:])
abbreviatedKey := "invalid"
if len(base64Key) == 44 {
abbreviatedKey = base64Key[0:4] + "…" + base64Key[39:43]
}
return abbreviatedKey
}