From 4c7741a337000094398bf361a981ff3387545e08 Mon Sep 17 00:00:00 2001
From: Michael Stapelberg <stapelberg@google.com>
Date: Tue, 26 Jun 2018 18:01:01 +0200
Subject: [PATCH] add backupd

---
 cmd/backupd/backupd.go          | 56 ++++++++++++++++++++++++++++
 internal/backup/backup.go       | 66 +++++++++++++++++++++++++++++++++
 internal/backup/backup_test.go  | 55 +++++++++++++++++++++++++++
 internal/netconfig/netconfig.go |  6 ++-
 4 files changed, 181 insertions(+), 2 deletions(-)
 create mode 100644 cmd/backupd/backupd.go
 create mode 100644 internal/backup/backup.go
 create mode 100644 internal/backup/backup_test.go

diff --git a/cmd/backupd/backupd.go b/cmd/backupd/backupd.go
new file mode 100644
index 0000000..0e95787
--- /dev/null
+++ b/cmd/backupd/backupd.go
@@ -0,0 +1,56 @@
+// Binary backupd provides tarballs of /perm.
+package main
+
+import (
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/gokrazy/gokrazy"
+
+	"router7/internal/backup"
+	"router7/internal/multilisten"
+	"router7/internal/teelogger"
+)
+
+var log = teelogger.NewConsole()
+
+var httpListeners = multilisten.NewPool()
+
+func updateListeners() error {
+	hosts, err := gokrazy.PrivateInterfaceAddrs()
+	if err != nil {
+		return err
+	}
+
+	httpListeners.ListenAndServe(hosts, func(host string) multilisten.Listener {
+		return &http.Server{Addr: net.JoinHostPort(host, "8077")}
+	})
+	return nil
+}
+
+func logic() error {
+	http.HandleFunc("/backup.tar.gz", func(w http.ResponseWriter, r *http.Request) {
+		if err := backup.Archive(w, "/perm"); err != nil {
+			log.Printf("backup.tar.gz: %v", err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+	})
+	updateListeners()
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch, syscall.SIGUSR1)
+	for range ch {
+		if err := updateListeners(); err != nil {
+			log.Printf("updateListeners: %v", err)
+		}
+	}
+	return nil
+}
+
+func main() {
+	if err := logic(); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/internal/backup/backup.go b/internal/backup/backup.go
new file mode 100644
index 0000000..cf9c403
--- /dev/null
+++ b/internal/backup/backup.go
@@ -0,0 +1,66 @@
+// Package backup generates tarballs of /perm.
+package backup
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+func Archive(w io.Writer, dir string) error {
+	gw, err := gzip.NewWriterLevel(w, gzip.BestSpeed)
+	if err != nil {
+		return err
+	}
+	defer gw.Close()
+	tw := tar.NewWriter(gw)
+
+	err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info == nil {
+			return fmt.Errorf("filepath.Walk: nil os.FileInfo")
+		}
+		if !info.Mode().IsRegular() && !info.Mode().IsDir() {
+			return nil // skip non-regular files/directories
+		}
+		if path == dir {
+			return nil // skip root
+		}
+		rel, err := filepath.Rel(dir, path)
+		if err != nil {
+			return err
+		}
+		hdr, err := tar.FileInfoHeader(info, "")
+		if err != nil {
+			return err
+		}
+		hdr.Name = rel
+		if err := tw.WriteHeader(hdr); err != nil {
+			return err
+		}
+		if !info.Mode().IsDir() {
+			b, err := ioutil.ReadFile(path)
+			if err != nil {
+				return err
+			}
+			if _, err := tw.Write(b); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	if err := tw.Close(); err != nil {
+		return err
+	}
+	return gw.Close()
+}
diff --git a/internal/backup/backup_test.go b/internal/backup/backup_test.go
new file mode 100644
index 0000000..9ff3f90
--- /dev/null
+++ b/internal/backup/backup_test.go
@@ -0,0 +1,55 @@
+package backup_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"router7/internal/backup"
+	"testing"
+)
+
+func TestArchive(t *testing.T) {
+	tmpin, err := ioutil.TempDir("", "backuptest")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpin)
+
+	if err := ioutil.WriteFile(filepath.Join(tmpin, "random.seed"), []byte{0xaa, 0xbb}, 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := os.MkdirAll(filepath.Join(tmpin, "dhcp4d"), 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(tmpin, "dhcp4d", "leases.json"), []byte("{}"), 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	var buf bytes.Buffer
+	if err := backup.Archive(&buf, tmpin); err != nil {
+		t.Fatal(err)
+	}
+
+	tmpout, err := ioutil.TempDir("", "backuptest")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpout)
+	tar := exec.Command("tar", "xzf", "-", "-C", tmpout)
+	tar.Stdin = &buf
+	tar.Stderr = os.Stderr
+	if err := tar.Run(); err != nil {
+		t.Fatal(err)
+	}
+
+	diff := exec.Command("diff", "-ur", tmpin, tmpout)
+	diff.Stdout = os.Stdout
+	diff.Stderr = os.Stderr
+	if err := diff.Run(); err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/internal/netconfig/netconfig.go b/internal/netconfig/netconfig.go
index 02b1fa0..ddd2a76 100644
--- a/internal/netconfig/netconfig.go
+++ b/internal/netconfig/netconfig.go
@@ -600,8 +600,10 @@ func Apply(dir, root string) error {
 	}
 
 	for _, process := range []string{
-		"dyndns", // depends on the public IPv4 address
-		"dnsd",   // listens on private IPv4/IPv6 and public IPv6Net1
+		"dyndns",  // depends on the public IPv4 address
+		"dnsd",    // listens on private IPv4/IPv6
+		"diagd",   // listens on private IPv4/IPv6
+		"backupd", // listens on private IPv4/IPv6
 	} {
 		if err := notify.Process("/user/"+process, syscall.SIGUSR1); err != nil {
 			log.Printf("notifying %s: %v", process, err)