diff options
| -rw-r--r-- | cmd/fpkg/bundle.go | 79 | ||||
| -rw-r--r-- | cmd/fpkg/install.go | 241 | ||||
| -rw-r--r-- | cmd/fpkg/main.go | 48 | ||||
| -rw-r--r-- | cmd/fpkg/paths.go | 71 | ||||
| -rw-r--r-- | cmd/fpkg/proc.go | 64 | ||||
| -rw-r--r-- | cmd/fpkg/start.go | 92 | ||||
| -rwxr-xr-x | dist/install.sh | 1 |
7 files changed, 596 insertions, 0 deletions
diff --git a/cmd/fpkg/bundle.go b/cmd/fpkg/bundle.go new file mode 100644 index 00000000..eb3150bb --- /dev/null +++ b/cmd/fpkg/bundle.go @@ -0,0 +1,79 @@ +package main + +import ( + "encoding/json" + "os" + + "git.gensokyo.uk/security/fortify/dbus" + "git.gensokyo.uk/security/fortify/internal/fmsg" + "git.gensokyo.uk/security/fortify/internal/system" +) + +type bundleInfo struct { + Name string `json:"name"` + Version string `json:"version"` + + // passed through to [fst.Config] + ID string `json:"id"` + // passed through to [fst.Config] + AppID int `json:"app_id"` + // passed through to [fst.Config] + Groups []string `json:"groups,omitempty"` + // passed through to [fst.Config] + UserNS bool `json:"userns,omitempty"` + // passed through to [fst.Config] + Net bool `json:"net,omitempty"` + // passed through to [fst.Config] + Dev bool `json:"dev,omitempty"` + // passed through to [fst.Config] + NoNewSession bool `json:"no_new_session,omitempty"` + // passed through to [fst.Config] + MapRealUID bool `json:"map_real_uid,omitempty"` + // passed through to [fst.Config] + DirectWayland bool `json:"direct_wayland,omitempty"` + // passed through to [fst.Config] + SystemBus *dbus.Config `json:"system_bus,omitempty"` + // passed through to [fst.Config] + SessionBus *dbus.Config `json:"session_bus,omitempty"` + // passed through to [fst.Config] + Enablements system.Enablements `json:"enablements"` + + // allow gpu access within sandbox + GPU bool `json:"gpu"` + // inner nix store path to activate-and-exec script + Launcher string `json:"launcher"` + // store path to /run/current-system + CurrentSystem string `json:"current_system"` + // home-manager activation package + ActivationPackage string `json:"activation_package"` +} + +func loadBundleInfo(name string, beforeFail func()) *bundleInfo { + bundle := new(bundleInfo) + if f, err := os.Open(name); err != nil { + beforeFail() + fmsg.Fatalf("cannot open bundle: %v", err) + } else if err = json.NewDecoder(f).Decode(&bundle); err != nil { + beforeFail() + fmsg.Fatalf("cannot parse bundle metadata: %v", err) + } else if err = f.Close(); err != nil { + fmsg.Printf("cannot close bundle metadata: %v", err) + // not fatal + } + + if bundle.ID == "" { + beforeFail() + fmsg.Fatal("application identifier must not be empty") + } + + return bundle +} + +func formatHostname(name string) string { + if h, err := os.Hostname(); err != nil { + fmsg.Printf("cannot get hostname: %v", err) + return "fortify-" + name + } else { + return h + "-" + name + } +} diff --git a/cmd/fpkg/install.go b/cmd/fpkg/install.go new file mode 100644 index 00000000..2ba2c223 --- /dev/null +++ b/cmd/fpkg/install.go @@ -0,0 +1,241 @@ +package main + +import ( + "encoding/json" + "flag" + "os" + "path" + + "git.gensokyo.uk/security/fortify/fst" + "git.gensokyo.uk/security/fortify/internal/fmsg" +) + +func actionInstall(args []string) { + set := flag.NewFlagSet("install", flag.ExitOnError) + var ( + dropShellInstall bool + dropShellActivate bool + ) + set.BoolVar(&dropShellInstall, "si", false, "Drop to a shell on installation") + set.BoolVar(&dropShellActivate, "sa", false, "Drop to a shell on activation") + + // Ignore errors; set is set for ExitOnError. + _ = set.Parse(args) + + args = set.Args() + + if len(args) != 1 { + fmsg.Fatal("invalid argument") + } + pkgPath := args[0] + if !path.IsAbs(pkgPath) { + if dir, err := os.Getwd(); err != nil { + fmsg.Fatalf("cannot get current directory: %v", err) + } else { + pkgPath = path.Join(dir, pkgPath) + } + } + + /* + Look up paths to programs started by fpkg. + This is done here to ease error handling as cleanup is not yet required. + */ + + var ( + _ = lookPath("zstd") + tar = lookPath("tar") + chmod = lookPath("chmod") + rm = lookPath("rm") + ) + + /* + Extract package and set up for cleanup. + */ + + var workDir string + if p, err := os.MkdirTemp("", "fpkg.*"); err != nil { + fmsg.Fatalf("cannot create temporary directory: %v", err) + } else { + workDir = p + } + cleanup := func() { + // should be faster than a native implementation + mustRun(chmod, "-R", "+w", workDir) + mustRun(rm, "-rf", workDir) + } + beforeRunFail.Store(&cleanup) + + mustRun(tar, "-C", workDir, "-xf", pkgPath) + + /* + Parse bundle and app metadata, do pre-install checks. + */ + + bundle := loadBundleInfo(path.Join(workDir, "bundle.json"), cleanup) + pathSet := pathSetByApp(bundle.ID) + + app := bundle + if s, err := os.Stat(pathSet.metaPath); err != nil { + if !os.IsNotExist(err) { + cleanup() + fmsg.Fatalf("cannot access %q: %v", pathSet.metaPath, err) + panic("unreachable") + } + // did not modify app, clean installation condition met later + } else if s.IsDir() { + cleanup() + fmsg.Fatalf("metadata path %q is not a file", pathSet.metaPath) + panic("unreachable") + } else { + app = loadBundleInfo(pathSet.metaPath, cleanup) + if app.ID != bundle.ID { + cleanup() + fmsg.Fatalf("app %q claims to have identifier %q", bundle.ID, app.ID) + } + // sec: should verify credentials + } + + if app != bundle { + // do not try to re-install + if app.Launcher == bundle.Launcher { + cleanup() + fmsg.Printf("package %q is identical to local application %q", pkgPath, app.ID) + fmsg.Exit(0) + } + + // AppID determines uid + if app.AppID != bundle.AppID { + cleanup() + fmsg.Fatalf("package %q app id %d differs from installed %d", pkgPath, bundle.AppID, app.AppID) + panic("unreachable") + } + + // sec: should compare version string + fmsg.VPrintf("installing application %q version %q over local %q", bundle.ID, bundle.Version, app.Version) + } else { + fmsg.VPrintf("application %q clean installation", bundle.ID) + // sec: should install credentials + } + + /* + Setup steps for files owned by the target user. + */ + + installConfig := &fst.Config{ + ID: bundle.ID, + Command: []string{shell, "-lc", "export BUNDLE=" + fst.Tmp + "/bundle && " + // export inner bundle path in the environment + "mkdir -p etc && chmod -R +w etc && rm -rf etc && cp -dRf $BUNDLE/etc etc && " + // replace inner /etc + "mkdir -p nix && chmod -R +w nix && rm -rf nix && cp -dRf /nix nix && " + // replace inner /nix + "nix copy --offline --no-check-sigs --all --from file://$BUNDLE/res --to $PWD && " + // copy from binary cache + "chmod 0755 .", // make cache directory world-readable for autoetc + }, + Confinement: fst.ConfinementConfig{ + AppID: bundle.AppID, + Username: "nixos", + Inner: path.Join("/data/data", bundle.ID, "cache"), + Outer: pathSet.cacheDir, // this also ensures cacheDir via fshim + Sandbox: &fst.SandboxConfig{ + Hostname: formatHostname(bundle.Name) + "-install", + NoNewSession: dropShellInstall, // nix copy should not need job control + Filesystem: []*fst.FilesystemConfig{ + {Src: path.Join(workDir, "nix"), Dst: "/nix", Must: true}, + {Src: workDir, Dst: path.Join(fst.Tmp, "bundle"), Must: true}, + }, + Link: [][2]string{ + {bundle.CurrentSystem, "/run/current-system"}, + {"/run/current-system/sw/bin", "/bin"}, + {"/run/current-system/sw/bin", "/usr/bin"}, + }, + Etc: path.Join(workDir, "etc"), + AutoEtc: true, + }, + ExtraPerms: []*fst.ExtraPermConfig{ + {Path: dataHome, Execute: true}, + {Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true}, + {Path: workDir, Execute: true}, + }, + }, + } + + if dropShellInstall { + installConfig.Command = []string{shell, "-l"} + fortifyApp(installConfig, cleanup) + cleanup() + fmsg.Exit(0) + } + fortifyApp(installConfig, cleanup) + + /* + Activate home-manager generation. + */ + + activateConfig := &fst.Config{ + ID: bundle.ID, + Command: []string{shell, "-lc", "nix-daemon --store / & " + // start nix-daemon + "(while [ ! -S /nix/var/nix/daemon-socket/socket ]; do sleep 0.01; done) && " + // wait for socket to appear + bundle.ActivationPackage + "/activate && " + // run activation script + "pkill nix-daemon", // terminate nix-daemon + }, + Confinement: fst.ConfinementConfig{ + AppID: bundle.AppID, + Groups: bundle.Groups, + Username: "fortify", + Inner: path.Join("/data/data", bundle.ID), + Outer: pathSet.homeDir, + Sandbox: &fst.SandboxConfig{ + Hostname: formatHostname(bundle.Name) + "-activate", + UserNS: true, // nix sandbox requires userns + NoNewSession: dropShellActivate, // home-manager activation should not need job control + Filesystem: []*fst.FilesystemConfig{ + {Src: pathSet.nixPath, Dst: "/nix", Write: true, Must: true}, + }, + Link: [][2]string{ + {bundle.CurrentSystem, "/run/current-system"}, + {"/run/current-system/sw/bin", "/bin"}, + {"/run/current-system/sw/bin", "/usr/bin"}, + }, + Etc: path.Join(pathSet.cacheDir, "etc"), + AutoEtc: true, + }, + ExtraPerms: []*fst.ExtraPermConfig{ + {Path: dataHome, Execute: true}, + {Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true}, + {Path: workDir, Execute: true}, + }, + }, + } + + if dropShellActivate { + activateConfig.Command = []string{shell, "-l"} + fortifyApp(activateConfig, cleanup) + cleanup() + fmsg.Exit(0) + } + fortifyApp(activateConfig, cleanup) + + /* + Installation complete. Write metadata to block re-installs or downgrades. + */ + + // serialise metadata to ensure consistency + if f, err := os.OpenFile(pathSet.metaPath+"~", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err != nil { + cleanup() + fmsg.Fatalf("cannot create metadata file: %v", err) + panic("unreachable") + } else if err = json.NewEncoder(f).Encode(bundle); err != nil { + cleanup() + fmsg.Fatalf("cannot write metadata: %v", err) + panic("unreachable") + } else if err = f.Close(); err != nil { + fmsg.Printf("cannot close metadata file: %v", err) + // not fatal + } + + if err := os.Rename(pathSet.metaPath+"~", pathSet.metaPath); err != nil { + cleanup() + fmsg.Fatalf("cannot rename metadata file: %v", err) + panic("unreachable") + } + + cleanup() +} diff --git a/cmd/fpkg/main.go b/cmd/fpkg/main.go new file mode 100644 index 00000000..f348cb5e --- /dev/null +++ b/cmd/fpkg/main.go @@ -0,0 +1,48 @@ +package main + +import ( + "flag" + "os" + + "git.gensokyo.uk/security/fortify/internal/fmsg" +) + +const shell = "/run/current-system/sw/bin/bash" + +func init() { + if err := os.Setenv("SHELL", shell); err != nil { + fmsg.Fatalf("cannot set $SHELL: %v", err) + } +} + +var ( + flagVerbose bool +) + +func init() { + flag.BoolVar(&flagVerbose, "v", false, "Verbose output") +} + +func main() { + fmsg.SetPrefix("fpkg") + + flag.Parse() + fmsg.SetVerbose(flagVerbose) + + args := flag.Args() + if len(args) < 1 { + fmsg.Fatal("invalid argument") + } + + switch args[0] { + case "install": + actionInstall(args[1:]) + case "start": + actionStart(args[1:]) + + default: + fmsg.Fatal("invalid argument") + } + + fmsg.Exit(0) +} diff --git a/cmd/fpkg/paths.go b/cmd/fpkg/paths.go new file mode 100644 index 00000000..cf36c096 --- /dev/null +++ b/cmd/fpkg/paths.go @@ -0,0 +1,71 @@ +package main + +import ( + "os" + "os/exec" + "path" + "strconv" + "sync/atomic" + + "git.gensokyo.uk/security/fortify/internal/fmsg" +) + +var ( + dataHome string +) + +func init() { + // dataHome + if p, ok := os.LookupEnv("FORTIFY_DATA_HOME"); ok { + dataHome = p + } else { + dataHome = "/var/lib/fortify/" + strconv.Itoa(os.Getuid()) + } +} + +func lookPath(file string) string { + if p, err := exec.LookPath(file); err != nil { + fmsg.Fatalf("%s: command not found", file) + panic("unreachable") + } else { + return p + } +} + +var beforeRunFail = new(atomic.Pointer[func()]) + +func mustRun(name string, arg ...string) { + fmsg.VPrintf("spawning process: %q %q", name, arg) + cmd := exec.Command(name, arg...) + cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr + if err := cmd.Run(); err != nil { + if f := beforeRunFail.Swap(nil); f != nil { + (*f)() + } + fmsg.Fatalf("%s: %v", name, err) + panic("unreachable") + } +} + +type appPathSet struct { + // ${dataHome}/${id} + baseDir string + // ${baseDir}/app + metaPath string + // ${baseDir}/files + homeDir string + // ${baseDir}/cache + cacheDir string + // ${baseDir}/cache/nix + nixPath string +} + +func pathSetByApp(id string) *appPathSet { + pathSet := new(appPathSet) + pathSet.baseDir = path.Join(dataHome, id) + pathSet.metaPath = path.Join(pathSet.baseDir, "app") + pathSet.homeDir = path.Join(pathSet.baseDir, "files") + pathSet.cacheDir = path.Join(pathSet.baseDir, "cache") + pathSet.nixPath = path.Join(pathSet.cacheDir, "nix") + return pathSet +} diff --git a/cmd/fpkg/proc.go b/cmd/fpkg/proc.go new file mode 100644 index 00000000..a995c9f1 --- /dev/null +++ b/cmd/fpkg/proc.go @@ -0,0 +1,64 @@ +package main + +import ( + "encoding/json" + "errors" + "io" + "os" + "os/exec" + + "git.gensokyo.uk/security/fortify/fst" + "git.gensokyo.uk/security/fortify/internal" + "git.gensokyo.uk/security/fortify/internal/fmsg" +) + +func fortifyApp(config *fst.Config, beforeFail func()) { + var ( + cmd *exec.Cmd + st io.WriteCloser + ) + if p, ok := internal.Check(internal.Fortify); !ok { + beforeFail() + fmsg.Fatal("invalid fortify path, this copy of fpkg is not compiled correctly") + panic("unreachable") + } else if r, w, err := os.Pipe(); err != nil { + beforeFail() + fmsg.Fatalf("cannot pipe: %v", err) + panic("unreachable") + } else { + if fmsg.Verbose() { + cmd = exec.Command(p, "-v", "app", "3") + } else { + cmd = exec.Command(p, "app", "3") + } + cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr + cmd.ExtraFiles = []*os.File{r} + st = w + } + + go func() { + if err := json.NewEncoder(st).Encode(config); err != nil { + beforeFail() + fmsg.Fatalf("cannot send configuration: %v", err) + panic("unreachable") + } + }() + + if err := cmd.Start(); err != nil { + beforeFail() + fmsg.Fatalf("cannot start fortify: %v", err) + panic("unreachable") + } + if err := cmd.Wait(); err != nil { + var exitError *exec.ExitError + if errors.As(err, &exitError) { + beforeFail() + fmsg.Exit(exitError.ExitCode()) + panic("unreachable") + } else { + beforeFail() + fmsg.Fatalf("cannot wait: %v", err) + panic("unreachable") + } + } +} diff --git a/cmd/fpkg/start.go b/cmd/fpkg/start.go new file mode 100644 index 00000000..498a3f35 --- /dev/null +++ b/cmd/fpkg/start.go @@ -0,0 +1,92 @@ +package main + +import ( + "flag" + "path" + + "git.gensokyo.uk/security/fortify/fst" + "git.gensokyo.uk/security/fortify/internal/fmsg" +) + +func actionStart(args []string) { + set := flag.NewFlagSet("start", flag.ExitOnError) + var dropShell bool + set.BoolVar(&dropShell, "s", false, "Drop to a shell on activation") + + // Ignore errors; set is set for ExitOnError. + _ = set.Parse(args) + + args = set.Args() + + if len(args) < 1 { + fmsg.Fatal("invalid argument") + } + id := args[0] + pathSet := pathSetByApp(id) + app := loadBundleInfo(pathSet.metaPath, func() {}) + + if app.ID != id { + fmsg.Fatalf("app %q claims to have identifier %q", id, app.ID) + } + + command := make([]string, 1, len(args)) + if !dropShell { + command[0] = app.Launcher + } else { + command[0] = shell + } + command = append(command, args[1:]...) + + config := &fst.Config{ + ID: app.ID, + Command: command, + Confinement: fst.ConfinementConfig{ + AppID: app.AppID, + Groups: app.Groups, + Username: "fortify", + Inner: path.Join("/data/data", app.ID), + Outer: pathSet.homeDir, + Sandbox: &fst.SandboxConfig{ + Hostname: formatHostname(app.Name), + UserNS: app.UserNS, + Net: app.Net, + Dev: app.Dev, + NoNewSession: app.NoNewSession || dropShell, + MapRealUID: app.MapRealUID, + DirectWayland: app.DirectWayland, + Filesystem: []*fst.FilesystemConfig{ + {Src: path.Join(pathSet.nixPath, "store"), Dst: "/nix/store", Must: true}, + {Src: pathSet.metaPath, Dst: path.Join(fst.Tmp, "app"), Must: true}, + {Src: "/etc/resolv.conf"}, + {Src: "/sys/block"}, + {Src: "/sys/bus"}, + {Src: "/sys/class"}, + {Src: "/sys/dev"}, + {Src: "/sys/devices"}, + }, + Link: [][2]string{ + {app.CurrentSystem, "/run/current-system"}, + {"/run/current-system/sw/bin", "/bin"}, + {"/run/current-system/sw/bin", "/usr/bin"}, + }, + Etc: path.Join(pathSet.cacheDir, "etc"), + AutoEtc: true, + }, + ExtraPerms: []*fst.ExtraPermConfig{ + {Path: dataHome, Execute: true}, + {Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true}, + }, + SystemBus: app.SystemBus, + SessionBus: app.SessionBus, + Enablements: app.Enablements, + }, + } + + if app.GPU { + config.Confinement.Sandbox.Filesystem = append(config.Confinement.Sandbox.Filesystem, + &fst.FilesystemConfig{Src: "/dev/dri", Device: true}) + } + + fortifyApp(config, func() {}) + fmsg.Exit(0) +} diff --git a/dist/install.sh b/dist/install.sh index 96949699..dcb5dc0d 100755 --- a/dist/install.sh +++ b/dist/install.sh @@ -4,6 +4,7 @@ cd "$(dirname -- "$0")" || exit 1 install -vDm0755 "bin/fortify" "${FORTIFY_INSTALL_PREFIX}/usr/bin/fortify" install -vDm0755 "bin/fshim" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/fshim" install -vDm0755 "bin/finit" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/finit" +install -vDm0755 "bin/fpkg" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/fpkg" install -vDm0755 "bin/fuserdb" "${FORTIFY_INSTALL_PREFIX}/usr/libexec/fortify/fuserdb" install -vDm6511 "bin/fsu" "${FORTIFY_INSTALL_PREFIX}/usr/bin/fsu" |