TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2024-11-25 11:05:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

types/result, util/lineiter: add package for a result type, use it

Browse Source 
This adds a new generic result type (motivated by golang/go#70084) to
try it out, and uses it in the new lineutil package (replacing the old
lineread package), changing that package to return iterators:
sometimes over []byte (when the input is all in memory), but sometimes
iterators over results of []byte, if errors might happen at runtime.

Updates #12912
Updates golang/go#70084

Change-Id: Iacdc1070e661b5fb163907b1e8b07ac7d51d3f83
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2024-11-04 20:49:40 -08:00 committed by Brad Fitzpatrick
parent 809a6eba80
commit 01185e436f
20 changed files with 290 additions and 139 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
cmd/derper/depaware.txt
View File

@ -140,6 +140,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
tailscale.com/types/persist from tailscale.com/ipn
tailscale.com/types/preftype from tailscale.com/ipn
tailscale.com/types/ptr from tailscale.com/hostinfo+
tailscale.com/types/result from tailscale.com/util/lineiter
tailscale.com/types/structs from tailscale.com/ipn+
tailscale.com/types/tkatype from tailscale.com/client/tailscale+
tailscale.com/types/views from tailscale.com/ipn+
@ -154,7 +155,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
tailscale.com/util/fastuuid from tailscale.com/tsweb
💣 tailscale.com/util/hashx from tailscale.com/util/deephash
tailscale.com/util/httpm from tailscale.com/client/tailscale
tailscale.com/util/lineread from tailscale.com/hostinfo+
tailscale.com/util/lineiter from tailscale.com/hostinfo+
L tailscale.com/util/linuxfw from tailscale.com/net/netns
tailscale.com/util/mak from tailscale.com/health+
tailscale.com/util/multierr from tailscale.com/health+

3
cmd/k8s-operator/depaware.txt
View File

@ -775,6 +775,7 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
tailscale.com/types/persist from tailscale.com/control/controlclient+
tailscale.com/types/preftype from tailscale.com/ipn+
tailscale.com/types/ptr from tailscale.com/cmd/k8s-operator+
tailscale.com/types/result from tailscale.com/util/lineiter
tailscale.com/types/structs from tailscale.com/control/controlclient+
tailscale.com/types/tkatype from tailscale.com/client/tailscale+
tailscale.com/types/views from tailscale.com/appc+
@ -792,7 +793,7 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
💣 tailscale.com/util/hashx from tailscale.com/util/deephash
tailscale.com/util/httphdr from tailscale.com/ipn/ipnlocal+
tailscale.com/util/httpm from tailscale.com/client/tailscale+
tailscale.com/util/lineread from tailscale.com/hostinfo+
tailscale.com/util/lineiter from tailscale.com/hostinfo+
L tailscale.com/util/linuxfw from tailscale.com/net/netns+
tailscale.com/util/mak from tailscale.com/appc+
tailscale.com/util/multierr from tailscale.com/control/controlclient+

3
cmd/stund/depaware.txt
View File

@ -67,6 +67,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
tailscale.com/types/logger from tailscale.com/tsweb
tailscale.com/types/opt from tailscale.com/envknob+
tailscale.com/types/ptr from tailscale.com/tailcfg+
tailscale.com/types/result from tailscale.com/util/lineiter
tailscale.com/types/structs from tailscale.com/tailcfg+
tailscale.com/types/tkatype from tailscale.com/tailcfg+
tailscale.com/types/views from tailscale.com/net/tsaddr+
@ -74,7 +75,7 @@ tailscale.com/cmd/stund dependencies: (generated by github.com/tailscale/depawar
L 💣 tailscale.com/util/dirwalk from tailscale.com/metrics
tailscale.com/util/dnsname from tailscale.com/tailcfg
tailscale.com/util/fastuuid from tailscale.com/tsweb
tailscale.com/util/lineread from tailscale.com/version/distro
tailscale.com/util/lineiter from tailscale.com/version/distro
tailscale.com/util/nocasemaps from tailscale.com/types/ipproto
tailscale.com/util/slicesx from tailscale.com/tailcfg
tailscale.com/util/vizerror from tailscale.com/tailcfg+

3
cmd/tailscale/depaware.txt
View File

@ -148,6 +148,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
tailscale.com/types/persist from tailscale.com/ipn
tailscale.com/types/preftype from tailscale.com/cmd/tailscale/cli+
tailscale.com/types/ptr from tailscale.com/hostinfo+
tailscale.com/types/result from tailscale.com/util/lineiter
tailscale.com/types/structs from tailscale.com/ipn+
tailscale.com/types/tkatype from tailscale.com/types/key+
tailscale.com/types/views from tailscale.com/tailcfg+
@ -162,7 +163,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
tailscale.com/util/groupmember from tailscale.com/client/web
💣 tailscale.com/util/hashx from tailscale.com/util/deephash
tailscale.com/util/httpm from tailscale.com/client/tailscale+
tailscale.com/util/lineread from tailscale.com/hostinfo+
tailscale.com/util/lineiter from tailscale.com/hostinfo+
L tailscale.com/util/linuxfw from tailscale.com/net/netns
tailscale.com/util/mak from tailscale.com/cmd/tailscale/cli+
tailscale.com/util/multierr from tailscale.com/control/controlhttp+

3
cmd/tailscaled/depaware.txt
View File

@ -364,6 +364,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
tailscale.com/types/persist from tailscale.com/control/controlclient+
tailscale.com/types/preftype from tailscale.com/ipn+
tailscale.com/types/ptr from tailscale.com/control/controlclient+
tailscale.com/types/result from tailscale.com/util/lineiter
tailscale.com/types/structs from tailscale.com/control/controlclient+
tailscale.com/types/tkatype from tailscale.com/tka+
tailscale.com/types/views from tailscale.com/ipn/ipnlocal+
@ -381,7 +382,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
💣 tailscale.com/util/hashx from tailscale.com/util/deephash
tailscale.com/util/httphdr from tailscale.com/ipn/ipnlocal+
tailscale.com/util/httpm from tailscale.com/client/tailscale+
tailscale.com/util/lineread from tailscale.com/hostinfo+
tailscale.com/util/lineiter from tailscale.com/hostinfo+
L tailscale.com/util/linuxfw from tailscale.com/net/netns+
tailscale.com/util/mak from tailscale.com/control/controlclient+
tailscale.com/util/multierr from tailscale.com/cmd/tailscaled+

24
hostinfo/hostinfo.go
View File

@ -25,7 +25,7 @@
"tailscale.com/types/ptr"
"tailscale.com/util/cloudenv"
"tailscale.com/util/dnsname"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
"tailscale.com/version"
"tailscale.com/version/distro"
)
@ -231,12 +231,12 @@ func desktop() (ret opt.Bool) {
}
seenDesktop := false
lineread.File("/proc/net/unix", func(line []byte) error {
for lr := range lineiter.File("/proc/net/unix") {
line, _ := lr.Value()
seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S(" @/tmp/dbus-"))
seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S(".X11-unix"))
seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S("/wayland-1"))
return nil
})
}
ret.Set(seenDesktop)
// Only cache after a minute - compositors might not have started yet.
@ -305,21 +305,21 @@ func inContainer() opt.Bool {
ret.Set(true)
return ret
}
lineread.File("/proc/1/cgroup", func(line []byte) error {
for lr := range lineiter.File("/proc/1/cgroup") {
line, _ := lr.Value()
if mem.Contains(mem.B(line), mem.S("/docker/")) ||
mem.Contains(mem.B(line), mem.S("/lxc/")) {
ret.Set(true)
return io.EOF // arbitrary non-nil error to stop loop
break
}
return nil
})
lineread.File("/proc/mounts", func(line []byte) error {
}
for lr := range lineiter.File("/proc/mounts") {
line, _ := lr.Value()
if mem.Contains(mem.B(line), mem.S("lxcfs /proc/cpuinfo fuse.lxcfs")) {
ret.Set(true)
return io.EOF
break
}
}
return nil
})
return ret
}

13
hostinfo/hostinfo_linux.go
View File

@ -12,7 +12,7 @@
"golang.org/x/sys/unix"
"tailscale.com/types/ptr"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
"tailscale.com/version/distro"
)
@ -106,15 +106,18 @@ func linuxVersionMeta() (meta versionMeta) {
}
m := map[string]string{}
lineread.File(propFile, func(line []byte) error {
for lr := range lineiter.File(propFile) {
line, err := lr.Value()
if err != nil {
break
}
eq := bytes.IndexByte(line, '=')
if eq == -1 {
return nil
continue
}
k, v := string(line[:eq]), strings.Trim(string(line[eq+1:]), `"'`)
m[k] = v
return nil
})
}
if v := m["VERSION_CODENAME"]; v != "" {
meta.DistroCodeName = v

22
ipn/ipnlocal/ssh.go
View File

@ -27,7 +27,7 @@
"github.com/tailscale/golang-x-crypto/ssh"
"go4.org/mem"
"tailscale.com/tailcfg"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
"tailscale.com/util/mak"
)
@ -80,30 +80,32 @@ func (b *LocalBackend) getSSHUsernames(req *tailcfg.C2NSSHUsernamesRequest) (*ta
if err != nil {
return nil, err
}
lineread.Reader(bytes.NewReader(out), func(line []byte) error {
for line := range lineiter.Bytes(out) {
line = bytes.TrimSpace(line)
if len(line) == 0 || line[0] == '_' {
return nil
continue
}
add(string(line))
return nil
})
}
default:
lineread.File("/etc/passwd", func(line []byte) error {
for lr := range lineiter.File("/etc/passwd") {
line, err := lr.Value()
if err != nil {
break
}
line = bytes.TrimSpace(line)
if len(line) == 0 || line[0] == '#' || line[0] == '_' {
return nil
continue
}
if mem.HasSuffix(mem.B(line), mem.S("/nologin")) ||
mem.HasSuffix(mem.B(line), mem.S("/false")) {
return nil
continue
}
colon := bytes.IndexByte(line, ':')
if colon != -1 {
add(string(line[:colon]))
}
return nil
})
}
}
return res, nil
}

51
net/netmon/interfaces_android.go
View File

@ -5,7 +5,6 @@
import (
"bytes"
"errors"
"log"
"net/netip"
"os/exec"
@ -15,7 +14,7 @@
"golang.org/x/sys/unix"
"tailscale.com/net/netaddr"
"tailscale.com/syncs"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
)
var (
@ -34,11 +33,6 @@ func init() {
var procNetRouteErr atomic.Bool
// errStopReading is a sentinel error value used internally by
// lineread.File callers to stop reading. It doesn't escape to
// callers/users.
var errStopReading = errors.New("stop reading")
/*
Parse 10.0.0.1 out of:
@ -54,44 +48,42 @@ func likelyHomeRouterIPAndroid() (ret netip.Addr, myIP netip.Addr, ok bool) {
}
lineNum := 0
var f []mem.RO
err := lineread.File(procNetRoutePath, func(line []byte) error {
for lr := range lineiter.File(procNetRoutePath) {
line, err := lr.Value()
if err != nil {
procNetRouteErr.Store(true)
return likelyHomeRouterIP()
}
lineNum++
if lineNum == 1 {
// Skip header line.
return nil
continue
}
if lineNum > maxProcNetRouteRead {
return errStopReading
break
}
f = mem.AppendFields(f[:0], mem.B(line))
if len(f) < 4 {
return nil
continue
}
gwHex, flagsHex := f[2], f[3]
flags, err := mem.ParseUint(flagsHex, 16, 16)
if err != nil {
return nil // ignore error, skip line and keep going
continue // ignore error, skip line and keep going
}
if flags&(unix.RTF_UP|unix.RTF_GATEWAY) != unix.RTF_UP|unix.RTF_GATEWAY {
return nil
continue
}
ipu32, err := mem.ParseUint(gwHex, 16, 32)
if err != nil {
return nil // ignore error, skip line and keep going
continue // ignore error, skip line and keep going
}
ip := netaddr.IPv4(byte(ipu32), byte(ipu32>>8), byte(ipu32>>16), byte(ipu32>>24))
if ip.IsPrivate() {
ret = ip
return errStopReading
break
}
return nil
})
if errors.Is(err, errStopReading) {
err = nil
}
if err != nil {
procNetRouteErr.Store(true)
return likelyHomeRouterIP()
}
if ret.IsValid() {
// Try to get the local IP of the interface associated with
@ -144,23 +136,26 @@ func likelyHomeRouterIPHelper() (ret netip.Addr, _ netip.Addr, ok bool) {
return
}
// Search for line like "default via 10.0.2.2 dev radio0 table 1016 proto static mtu 1500 "
lineread.Reader(out, func(line []byte) error {
for lr := range lineiter.Reader(out) {
line, err := lr.Value()
if err != nil {
break
}
const pfx = "default via "
if !mem.HasPrefix(mem.B(line), mem.S(pfx)) {
return nil
continue
}
line = line[len(pfx):]
sp := bytes.IndexByte(line, ' ')
if sp == -1 {
return nil
continue
}
ipb := line[:sp]
if ip, err := netip.ParseAddr(string(ipb)); err == nil && ip.Is4() {
ret = ip
log.Printf("interfaces: found Android default route %v", ip)
}
return nil
})
}
cmd.Process.Kill()
cmd.Wait()
return ret, netip.Addr{}, ret.IsValid()

24
net/netmon/interfaces_darwin_test.go
View File

@ -4,14 +4,13 @@
package netmon
import (
"errors"
"io"
"net/netip"
"os/exec"
"testing"
"go4.org/mem"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
"tailscale.com/version"
)
@ -73,31 +72,34 @@ func likelyHomeRouterIPDarwinExec() (ret netip.Addr, netif string, ok bool) {
defer io.Copy(io.Discard, stdout) // clear the pipe to prevent hangs
var f []mem.RO
lineread.Reader(stdout, func(lineb []byte) error {
for lr := range lineiter.Reader(stdout) {
lineb, err := lr.Value()
if err != nil {
break
}
line := mem.B(lineb)
if !mem.Contains(line, mem.S("default")) {
return nil
continue
}
f = mem.AppendFields(f[:0], line)
if len(f) < 4 || !f[0].EqualString("default") {
return nil
continue
}
ipm, flagsm, netifm := f[1], f[2], f[3]
if !mem.Contains(flagsm, mem.S("G")) {
return nil
continue
}
if mem.Contains(flagsm, mem.S("I")) {
return nil
continue
}
ip, err := netip.ParseAddr(string(mem.Append(nil, ipm)))
if err == nil && ip.IsPrivate() {
ret = ip
netif = netifm.StringCopy()
// We've found what we're looking for.
return errStopReadingNetstatTable
break
}
}
return nil
})
return ret, netif, ret.IsValid()
}
@ -110,5 +112,3 @@ func TestFetchRoutingTable(t *testing.T) {
}
}
}
var errStopReadingNetstatTable = errors.New("found private gateway")

37
net/netmon/interfaces_linux.go
View File

@ -23,7 +23,7 @@
"go4.org/mem"
"golang.org/x/sys/unix"
"tailscale.com/net/netaddr"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
)
func init() {
@ -32,11 +32,6 @@ func init() {
var procNetRouteErr atomic.Bool
// errStopReading is a sentinel error value used internally by
// lineread.File callers to stop reading. It doesn't escape to
// callers/users.
var errStopReading = errors.New("stop reading")
/*
Parse 10.0.0.1 out of:
@ -52,44 +47,42 @@ func likelyHomeRouterIPLinux() (ret netip.Addr, myIP netip.Addr, ok bool) {
}
lineNum := 0
var f []mem.RO
err := lineread.File(procNetRoutePath, func(line []byte) error {
for lr := range lineiter.File(procNetRoutePath) {
line, err := lr.Value()
if err != nil {
procNetRouteErr.Store(true)
log.Printf("interfaces: failed to read /proc/net/route: %v", err)
return ret, myIP, false
}
lineNum++
if lineNum == 1 {
// Skip header line.
return nil
continue
}
if lineNum > maxProcNetRouteRead {
return errStopReading
break
}
f = mem.AppendFields(f[:0], mem.B(line))
if len(f) < 4 {
return nil
continue
}
gwHex, flagsHex := f[2], f[3]
flags, err := mem.ParseUint(flagsHex, 16, 16)
if err != nil {
return nil // ignore error, skip line and keep going
continue // ignore error, skip line and keep going
}
if flags&(unix.RTF_UP|unix.RTF_GATEWAY) != unix.RTF_UP|unix.RTF_GATEWAY {
return nil
continue
}
ipu32, err := mem.ParseUint(gwHex, 16, 32)
if err != nil {
return nil // ignore error, skip line and keep going
continue // ignore error, skip line and keep going
}
ip := netaddr.IPv4(byte(ipu32), byte(ipu32>>8), byte(ipu32>>16), byte(ipu32>>24))
if ip.IsPrivate() {
ret = ip
return errStopReading
break
}
return nil
})
if errors.Is(err, errStopReading) {
err = nil
}
if err != nil {
procNetRouteErr.Store(true)
log.Printf("interfaces: failed to read /proc/net/route: %v", err)
}
if ret.IsValid() {
// Try to get the local IP of the interface associated with

2
net/netmon/netmon_linux_test.go
View File

@ -1,6 +1,8 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux && !android
package netmon
import (

15
net/tshttpproxy/tshttpproxy_synology.go
View File

@ -17,7 +17,7 @@
"sync"
"time"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
)
// These vars are overridden for tests.
@ -76,21 +76,22 @@ func synologyProxiesFromConfig() (*url.URL, *url.URL, error) {
func parseSynologyConfig(r io.Reader) (*url.URL, *url.URL, error) {
cfg := map[string]string{}
if err := lineread.Reader(r, func(line []byte) error {
for lr := range lineiter.Reader(r) {
line, err := lr.Value()
if err != nil {
return nil, nil, err
}
// accept and skip over empty lines
line = bytes.TrimSpace(line)
if len(line) == 0 {
return nil
continue
}
key, value, ok := strings.Cut(string(line), "=")
if !ok {
return fmt.Errorf("missing \"=\" in proxy.conf line: %q", line)
return nil, nil, 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" {

13
ssh/tailssh/tailssh_test.go
View File

@ -48,7 +48,7 @@
"tailscale.com/types/netmap"
"tailscale.com/types/ptr"
"tailscale.com/util/cibuild"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
"tailscale.com/util/must"
"tailscale.com/version/distro"
"tailscale.com/wgengine"
@ -1123,14 +1123,11 @@ func TestSSH(t *testing.T) {
func parseEnv(out []byte) map[string]string {
e := map[string]string{}
lineread.Reader(bytes.NewReader(out), func(line []byte) error {
i := bytes.IndexByte(line, '=')
if i == -1 {
return nil
}
for line := range lineiter.Bytes(out) {
if i := bytes.IndexByte(line, '='); i != -1 {
e[string(line[:i])] = string(line[i+1:])
return nil
})
}
}
return e
}

20
ssh/tailssh/user.go
View File

@ -6,7 +6,6 @@
package tailssh
import (
"io"
"os"
"os/exec"
"os/user"
@ -18,7 +17,7 @@
"go4.org/mem"
"tailscale.com/envknob"
"tailscale.com/hostinfo"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
"tailscale.com/util/osuser"
"tailscale.com/version/distro"
)
@ -110,15 +109,16 @@ func defaultPathForUser(u *user.User) string {
}
func defaultPathForUserOnNixOS(u *user.User) string {
var path string
lineread.File("/etc/pam/environment", func(lineb []byte) error {
if v := pathFromPAMEnvLine(lineb, u); v != "" {
path = v
return io.EOF // stop iteration
for lr := range lineiter.File("/etc/pam/environment") {
lineb, err := lr.Value()
if err != nil {
return ""
}
return nil
})
return path
if v := pathFromPAMEnvLine(lineb, u); v != "" {
return v
}
}
return ""
}
func pathFromPAMEnvLine(line []byte, u *user.User) (path string) {

49
types/result/result.go Normal file
View File

@ -0,0 +1,49 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// Package result contains the Of result type, which is
// either a value or an error.
package result
// Of is either a T value or an error.
//
// Think of it like Rust or Swift's result types.
// It's named "Of" because the fully qualified name
// for callers reads result.Of[T].
type Of[T any] struct {
v T // valid if Err is nil; invalid if Err is non-nil
err error
}
// Value returns a new result with value v,
// without an error.
func Value[T any](v T) Of[T] {
return Of[T]{v: v}
}
// Error returns a new result with error err.
// If err is nil, the returned result is equivalent
// to calling Value with T's zero value.
func Error[T any](err error) Of[T] {
return Of[T]{err: err}
}
// MustValue returns r's result value.
// It panics if r.Err returns non-nil.
func (r Of[T]) MustValue() T {
if r.err != nil {
panic(r.err)
}
return r.v
}
// Value returns r's result value and error.
func (r Of[T]) Value() (T, error) {
return r.v, r.err
}
// Err returns r's error, if any.
// When r.Err returns nil, it's safe to call r.MustValue without it panicking.
func (r Of[T]) Err() error {
return r.err
}

72
util/lineiter/lineiter.go Normal file
View File

@ -0,0 +1,72 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// Package lineiter iterates over lines in things.
package lineiter
import (
"bufio"
"bytes"
"io"
"iter"
"os"
"tailscale.com/types/result"
)
// File returns an iterator that reads lines from the named file.
//
// The returned substrings don't include the trailing newline.
// Lines may be empty.
func File(name string) iter.Seq[result.Of[[]byte]] {
f, err := os.Open(name)
return reader(f, f, err)
}
// Bytes returns an iterator over the lines in bs.
// The returned substrings don't include the trailing newline.
// Lines may be empty.
func Bytes(bs []byte) iter.Seq[[]byte] {
return func(yield func([]byte) bool) {
for len(bs) > 0 {
i := bytes.IndexByte(bs, '\n')
if i < 0 {
yield(bs)
return
}
if !yield(bs[:i]) {
return
}
bs = bs[i+1:]
}
}
}
// Reader returns an iterator over the lines in r.
//
// The returned substrings don't include the trailing newline.
// Lines may be empty.
func Reader(r io.Reader) iter.Seq[result.Of[[]byte]] {
return reader(r, nil, nil)
}
func reader(r io.Reader, c io.Closer, err error) iter.Seq[result.Of[[]byte]] {
return func(yield func(result.Of[[]byte]) bool) {
if err != nil {
yield(result.Error[[]byte](err))
return
}
if c != nil {
defer c.Close()
}
bs := bufio.NewScanner(r)
for bs.Scan() {
if !yield(result.Value(bs.Bytes())) {
return
}
}
if err := bs.Err(); err != nil {
yield(result.Error[[]byte](err))
}
}
}

32
util/lineiter/lineiter_test.go Normal file
View File

@ -0,0 +1,32 @@
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package lineiter
import (
"slices"
"strings"
"testing"
)
func TestBytesLines(t *testing.T) {
var got []string
for line := range Bytes([]byte("foo\n\nbar\nbaz")) {
got = append(got, string(line))
}
want := []string{"foo", "", "bar", "baz"}
if !slices.Equal(got, want) {
t.Errorf("got %q; want %q", got, want)
}
}
func TestReader(t *testing.T) {
var got []string
for line := range Reader(strings.NewReader("foo\n\nbar\nbaz")) {
got = append(got, string(line.MustValue()))
}
want := []string{"foo", "", "bar", "baz"}
if !slices.Equal(got, want) {
t.Errorf("got %q; want %q", got, want)
}
}

20
util/pidowner/pidowner_linux.go
View File

@ -8,26 +8,26 @@
"os"
"strings"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
)
func ownerOfPID(pid int) (userID string, err error) {
file := fmt.Sprintf("/proc/%d/status", pid)
err = lineread.File(file, func(line []byte) error {
for lr := range lineiter.File(file) {
line, err := lr.Value()
if err != nil {
if os.IsNotExist(err) {
return "", ErrProcessNotFound
}
return "", err
}
if len(line) < 4 || string(line[:4]) != "Uid:" {
return nil
continue
}
f := strings.Fields(string(line))
if len(f) >= 2 {
userID = f[1] // real userid
}
return nil
})
if os.IsNotExist(err) {
return "", ErrProcessNotFound
}
if err != nil {
return
}
if userID == "" {
return "", fmt.Errorf("missing Uid line in %s", file)

20
version/distro/distro.go
View File

@ -6,13 +6,12 @@
import (
"bytes"
"io"
"os"
"runtime"
"strconv"
"tailscale.com/types/lazy"
"tailscale.com/util/lineread"
"tailscale.com/util/lineiter"
)
type Distro string
@ -132,18 +131,19 @@ func DSMVersion() int {
return v
}
// But when run from the command line, we have to read it from the file:
lineread.File("/etc/VERSION", func(line []byte) error {
for lr := range lineiter.File("/etc/VERSION") {
line, err := lr.Value()
if err != nil {
break // but otherwise ignore
}
line = bytes.TrimSpace(line)
if string(line) == `majorversion="7"` {
v = 7
return io.EOF
return 7
}
if string(line) == `majorversion="6"` {
v = 6
return io.EOF
return 6
}
return nil
})
return v
}
return 0
})
}