hostinfo/hostinfo_linux.go
Rama main · réplica de lectura del repositorio original.
// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux && !android
package hostinfo
import (
"bytes"
"context"
"encoding/json"
"os"
"os/exec"
"strings"
"time"
"golang.org/x/sys/unix"
"tailscale.com/util/lineiter"
"tailscale.com/version/distro"
)
func init() {
osVersion = lazyOSVersion.Get
packageType = packageTypeLinux
distroName = distroNameLinux
distroVersion = distroVersionLinux
distroCodeName = distroCodeNameLinux
deviceModel = deviceModelLinux
systemdLogindDesktop = hasLogindDesktop
}
var (
lazyVersionMeta = &lazyAtomicValue[versionMeta]{f: new(linuxVersionMeta)}
lazyOSVersion = &lazyAtomicValue[string]{f: new(osVersionLinux)}
)
type versionMeta struct {
DistroName string
DistroVersion string
DistroCodeName string // "jammy", etc (VERSION_CODENAME from /etc/os-release)
}
func distroNameLinux() string {
return lazyVersionMeta.Get().DistroName
}
func distroVersionLinux() string {
return lazyVersionMeta.Get().DistroVersion
}
func distroCodeNameLinux() string {
return lazyVersionMeta.Get().DistroCodeName
}
func deviceModelLinux() string {
for _, path := range []string{
// First try the Synology-specific location.
// Example: "DS916+-j"
"/proc/sys/kernel/syno_hw_version",
// Otherwise, try the Devicetree model, usually set on
// ARM SBCs, etc.
// Example: "Raspberry Pi 4 Model B Rev 1.2"
// Example: "WD My Cloud Gen2: Marvell Armada 375"
"/sys/firmware/devicetree/base/model", // Raspberry Pi 4 Model B Rev 1.2"
} {
b, _ := os.ReadFile(path)
if s := strings.Trim(string(b), "\x00\r\n\t "); s != "" {
return s
}
}
return ""
}
func getQnapQtsVersion(versionInfo string) string {
for field := range strings.FieldsSeq(versionInfo) {
if suffix, ok := strings.CutPrefix(field, "QTSFW_"); ok {
return suffix
}
}
return ""
}
func osVersionLinux() string {
var un unix.Utsname
unix.Uname(&un)
return unix.ByteSliceToString(un.Release[:])
}
func linuxVersionMeta() (meta versionMeta) {
dist := distro.Get()
meta.DistroName = string(dist)
propFile := "/etc/os-release"
switch dist {
case distro.Synology:
propFile = "/etc.defaults/VERSION"
case distro.OpenWrt:
propFile = "/etc/openwrt_release"
case distro.Unraid:
propFile = "/etc/unraid-version"
case distro.WDMyCloud:
slurp, _ := os.ReadFile("/etc/version")
meta.DistroVersion = string(bytes.TrimSpace(slurp))
return
case distro.QNAP:
slurp, _ := os.ReadFile("/etc/version_info")
meta.DistroVersion = getQnapQtsVersion(string(slurp))
return
}
m := map[string]string{}
for lr := range lineiter.File(propFile) {
line, err := lr.Value()
if err != nil {
break
}
before, after, ok := bytes.Cut(line, []byte{'='})
if !ok {
continue
}
k, v := string(before), strings.Trim(string(after), `"'`)
m[k] = v
}
if v := m["VERSION_CODENAME"]; v != "" {
meta.DistroCodeName = v
}
if v := m["VERSION_ID"]; v != "" {
meta.DistroVersion = v
}
id := m["ID"]
if id != "" {
meta.DistroName = id
}
switch id {
case "debian":
// Debian's VERSION_ID is just like "11". But /etc/debian_version has "11.5" normally.
// Or "bookworm/sid" on sid/testing.
slurp, _ := os.ReadFile("/etc/debian_version")
if v := string(bytes.TrimSpace(slurp)); v != "" {
if '0' <= v[0] && v[0] <= '9' {
meta.DistroVersion = v
} else if meta.DistroCodeName == "" {
meta.DistroCodeName = v
}
}
case "", "centos": // CentOS 6 has no /etc/os-release, so its id is ""
if meta.DistroVersion == "" {
if cr, _ := os.ReadFile("/etc/centos-release"); len(cr) > 0 { // "CentOS release 6.10 (Final)
meta.DistroVersion = string(bytes.TrimSpace(cr))
}
}
}
if v := m["PRETTY_NAME"]; v != "" && meta.DistroVersion == "" && !strings.HasSuffix(v, "/sid") {
meta.DistroVersion = v
}
switch dist {
case distro.Synology:
meta.DistroVersion = m["productversion"]
case distro.OpenWrt:
meta.DistroVersion = m["DISTRIB_RELEASE"]
case distro.Unraid:
meta.DistroVersion = m["version"]
}
return
}
// linuxBuildTagPackageType is set by packagetype_*.go
// build tag guarded files.
var linuxBuildTagPackageType string
func packageTypeLinux() string {
if v := linuxBuildTagPackageType; v != "" {
return v
}
// Report whether this is in a snap.
// See https://snapcraft.io/docs/environment-variables
// We just look at two somewhat arbitrarily.
if os.Getenv("SNAP_NAME") != "" && os.Getenv("SNAP") != "" {
return "snap"
}
return ""
}
// hasLogindDesktop calls [systemdLogindFindDesktop] with a 100 millisecond
// timeout.
func hasLogindDesktop() bool {
ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
defer cancel()
runner := &osLogindRunner{ctx: ctx}
return systemdLogindFindDesktop(runner)
}
// logindConn is the interface for querying systemd-logind session information.
// It exists to be able to swap the backend for testing.
type logindRunner interface {
// listSessions returns the raw JSON output of
// "loginctl list-sessions --json=short", which is a json blob containing
// output like: '[{"session":"8"},{"session":"9"}]'.
listSessions() ([]byte, error)
// getSessionType returns the raw output of
// "loginctl show-session <id> --property=Type", which is a single line of
// the form "Type=<value>".
getSessionType(string) (string, error)
}
// osLogindRunner implements [logindRunner] by shelling out to the
// system logind. The probes drop the systemd service variables.
// loginctl sends sd_notify(3) messages on exit and error. systemd
// rejects these messages because they come from the wrong PID. See
// [EnvironWithoutSystemdServiceVars].
type osLogindRunner struct{ ctx context.Context }
// listSessions implements [logindRunner] using os calls.
func (r *osLogindRunner) listSessions() ([]byte, error) {
path, err := exec.LookPath("loginctl")
if err != nil {
return nil, err
}
cmd := exec.CommandContext(r.ctx, path, "list-sessions", "--json=short")
cmd.Env = EnvironWithoutSystemdServiceVars(nil)
output, err := cmd.Output()
if err != nil {
return nil, err
}
return output, nil
}
// getSessionType implements [logindRunner] using os calls.
func (r *osLogindRunner) getSessionType(session string) (string, error) {
path, err := exec.LookPath("loginctl")
if err != nil {
return "", err
}
cmd := exec.CommandContext(r.ctx,
path, "show-session", session, "--property=Type", "--value")
cmd.Env = EnvironWithoutSystemdServiceVars(nil)
output, err := cmd.Output()
if err != nil {
return "", err
}
return string(output), nil
}
// systemdLogindFindDesktop reports whether any active logind session has a
// graphical desktop type (x11, wayland, or mir). On an error or with no types
// matching the list above, it returns false.
func systemdLogindFindDesktop(logind logindRunner) bool {
sessionJSON, err := logind.listSessions()
if err != nil {
return false
}
type session struct {
Session string `json:"session"`
}
var sessions []session
err = json.Unmarshal(sessionJSON, &sessions)
if err != nil {
return false
}
for _, sess := range sessions {
typeString, err := logind.getSessionType(sess.Session)
if err != nil {
continue
}
switch strings.ToLower(strings.TrimSpace(typeString)) {
case "wayland", "x11", "mir":
return true
}
}
return false
}