app/dbus: manage dbus proxy and pass address to child

This commit adds code that starts and registers the D-Bus proxy, as well as cleanup code that tracks and closes the daemon once our child exits. A few more flags were added to pass D-Bus config to xdg-dbus-proxy.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>
This commit is contained in:
Ophestra 2024-09-09 03:16:54 +09:00
parent 357cc4ce4d
commit 38ef2b4d0c
Signed by: cat
SSH Key Fingerprint: SHA256:gQ67O0enBZ7UdZypgtspB2FDM1g3GVw8nX0XSdcFw8Q
6 changed files with 142 additions and 7 deletions

8
cli.go
View File

@ -8,6 +8,9 @@ import (
var (
userName string
dbusConfig string
dbusID string
mpris bool
mustWayland bool
mustX bool
@ -19,7 +22,10 @@ var (
)
func init() {
flag.StringVar(&userName, "u", "chronos", "Specify a username")
flag.StringVar(&userName, "u", "chronos", "Passwd name of user to run as")
flag.StringVar(&dbusConfig, "dbus-config", "builtin", "Path to D-Bus proxy config file, or \"builtin\" for defaults")
flag.StringVar(&dbusID, "dbus-id", "", "D-Bus ID of application, leave empty to disable own paths, has no effect if custom config is available")
flag.BoolVar(&mpris, "mpris", false, "Allow owning MPRIS D-Bus path, has no effect if custom config is available")
flag.BoolVar(&mustWayland, "wayland", false, "Share Wayland socket")
flag.BoolVar(&mustX, "X", false, "Share X11 socket and allow connection")

View File

@ -1,14 +1,92 @@
package app
import (
"errors"
"fmt"
"os"
"path"
"strconv"
"git.ophivana.moe/cat/fortify/dbus"
"git.ophivana.moe/cat/fortify/internal/acl"
"git.ophivana.moe/cat/fortify/internal/state"
"git.ophivana.moe/cat/fortify/internal/system"
"git.ophivana.moe/cat/fortify/internal/util"
)
func (a *App) ShareDBus() {
const dbusSessionBusAddress = "DBUS_SESSION_BUS_ADDRESS"
var dbusAddress string
func (a *App) ShareDBus(c *dbus.Config) {
a.setEnablement(state.EnableDBus)
// TODO: start xdg-dbus-proxy
fmt.Println("warn: dbus proxy not implemented")
var binPath, address string
target := path.Join(system.V.Share, strconv.Itoa(os.Getpid()))
if b, ok := util.Which("xdg-dbus-proxy"); !ok {
state.Fatal("D-Bus: Did not find 'xdg-dbus-proxy' in PATH")
} else {
binPath = b
}
if addr, ok := os.LookupEnv(dbusSessionBusAddress); !ok {
state.Fatal("D-Bus: DBUS_SESSION_BUS_ADDRESS not set")
} else {
address = addr
}
c.Log = system.V.Verbose
p := dbus.New(binPath, address, target)
if system.V.Verbose {
fmt.Println("D-Bus: sealing proxy", c.Args(address, target))
}
if err := p.Seal(c); err != nil {
state.Fatal("D-Bus: invalid config when sealing proxy,", err)
}
ready := make(chan bool, 1)
done := make(chan struct{})
if system.V.Verbose {
fmt.Printf("Starting session bus proxy '%s' for address '%s'\n", dbusAddress, address)
}
if err := p.Start(&ready); err != nil {
state.Fatal("D-Bus: error starting proxy,", err)
}
if system.V.Verbose {
fmt.Println("D-Bus proxy launch:", p)
}
go func() {
if err := p.Wait(); err != nil {
fmt.Println("warn: D-Bus proxy returned error,", err)
} else {
if system.V.Verbose {
fmt.Println("D-Bus proxy uneventful wait")
}
}
if err := os.Remove(target); err != nil && !errors.Is(err, os.ErrNotExist) {
fmt.Println("Error removing dangling D-Bus socket:", err)
}
done <- struct{}{}
}()
// register early to enable Fatal cleanup
state.RegisterDBus(p, &done)
dbusAddress = "unix:path=" + target
if !<-ready {
state.Fatal("D-Bus: proxy did not start correctly")
}
a.AppendEnv(dbusSessionBusAddress, dbusAddress)
if err := acl.UpdatePerm(target, a.UID(), acl.Read, acl.Write); err != nil {
state.Fatal(fmt.Sprintf("Error preparing D-Bus proxy '%s':", dbusAddress), err)
} else {
state.RegisterRevertPath(target)
}
if system.V.Verbose {
fmt.Printf("Session bus proxy '%s' for address '%s' configured\n", dbusAddress, address)
}
}

View File

@ -166,6 +166,9 @@ func (a *App) commandBuilderMachineCtl() (args []string) {
if executable, err := os.Executable(); err != nil {
state.Fatal("Error reading executable path:", err)
} else {
if a.enablements.Has(state.EnableDBus) {
innerCommand.WriteString(dbusSessionBusAddress + "=" + "'" + dbusAddress + "' ")
}
innerCommand.WriteString("exec " + executable + " -V")
}
args = append(args, innerCommand.String())

View File

@ -65,4 +65,23 @@ func BeforeExit() {
fmt.Printf("Stripped ACL entry for user '%s' from '%s'\n", u.Username, candidate)
}
}
if dbusProxy != nil {
if system.V.Verbose {
fmt.Println("D-Bus proxy registered, cleaning up")
}
if err := dbusProxy.Close(); err != nil {
if errors.Is(err, os.ErrClosed) {
if system.V.Verbose {
fmt.Println("D-Bus proxy already closed")
}
} else {
fmt.Println("Error closing D-Bus proxy:", err)
}
}
// wait for Proxy.Wait to return
<-*dbusDone
}
}

View File

@ -1,9 +1,14 @@
package state
import "git.ophivana.moe/cat/fortify/dbus"
var (
cleanupCandidate []string
enablements *Enablements
xcbActionComplete bool
dbusProxy *dbus.Proxy
dbusDone *chan struct{}
)
func RegisterRevertPath(p string) {
@ -23,3 +28,8 @@ func XcbActionComplete() {
}
xcbActionComplete = true
}
func RegisterDBus(p *dbus.Proxy, done *chan struct{}) {
dbusProxy = p
dbusDone = done
}

21
main.go
View File

@ -1,6 +1,7 @@
package main
import (
"encoding/json"
"errors"
"flag"
"fmt"
@ -9,6 +10,7 @@ import (
"strconv"
"syscall"
"git.ophivana.moe/cat/fortify/dbus"
"git.ophivana.moe/cat/fortify/internal/acl"
"git.ophivana.moe/cat/fortify/internal/app"
"git.ophivana.moe/cat/fortify/internal/state"
@ -17,7 +19,9 @@ import (
var (
Version = "impure"
a *app.App
c *dbus.Config
)
func tryVersion() {
@ -41,6 +45,21 @@ func main() {
a = app.New(userName, flag.Args())
state.Set(*a.User, a.Command(), a.UID())
// parse D-Bus config file if applicable
if mustDBus {
if dbusConfig == "builtin" {
c = dbus.NewConfig(dbusID, true, mpris)
} else {
if f, err := os.Open(dbusConfig); err != nil {
state.Fatal("Error opening D-Bus proxy config file:", err)
} else {
if err = json.NewDecoder(f).Decode(&c); err != nil {
state.Fatal("Error parsing D-Bus proxy config file:", err)
}
}
}
}
// ensure RunDir (e.g. `/run/user/%d/fortify`)
if err := os.Mkdir(system.V.RunDir, 0700); err != nil && !errors.Is(err, fs.ErrExist) {
state.Fatal("Error creating runtime directory:", err)
@ -103,7 +122,7 @@ func main() {
}
if mustDBus {
a.ShareDBus()
a.ShareDBus(c)
}
if mustPulse {