modemkicker: init

main.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/http/cookiejar"
+	"net/url"
+	"strings"
+)
+
+var (
+	flagAddress  string
+	flagUsername string
+	flagPassword string
+)
+
+const (
+	sessionKey = "SESSION_ID_VIGOR"
+)
+
+func makeAddress(page string) string {
+	u, err := url.Parse(flagAddress)
+	if err != nil {
+		panic(fmt.Sprintf("Invalid address (%q): %v", flagAddress, err))
+	}
+	u = u.JoinPath(page)
+	return u.String()
+}
+
+type client struct {
+	random string
+	jar    *cookiejar.Jar
+}
+
+func (c *client) doRequest(ctx context.Context, body io.Reader, method, url, referer string) (*http.Response, error) {
+	req, err := http.NewRequestWithContext(ctx, method, url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Add("Referer", referer)
+	req.Header.Add("Origin", makeAddress(""))
+
+	client := &http.Client{
+		Jar: c.jar,
+	}
+
+	return client.Do(req)
+}
+
+func (c *client) getSession(ctx context.Context) error {
+	// Get session.
+	c.random = rand.Text()[:15]
+	form := url.Values{}
+	form.Add("aa", base64.StdEncoding.EncodeToString([]byte(flagUsername)))
+	form.Add("ab", base64.StdEncoding.EncodeToString([]byte(flagPassword)))
+	form.Add("sFormAuthStr", c.random)
+
+	res, err := c.doRequest(ctx, strings.NewReader(form.Encode()), "POST", makeAddress("cgi-bin/wlogin.cgi"), makeAddress("weblogin.htm"))
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	body, _ := io.ReadAll(res.Body)
+
+	if strings.Contains(string(body), "Authorization Error") {
+		return fmt.Errorf("authorization error on wlogin.cgi")
+	}
+
+	// Check that auth works.
+	res, err = c.doRequest(ctx, nil, "GET", makeAddress("cgi-bin/cgidashboard.cgi")+fmt.Sprintf("?sFormAuthStr=%s&fid=1", c.random), makeAddress(""))
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	body, _ = io.ReadAll(res.Body)
+
+	if strings.Contains(string(body), "Authorization Error") {
+		return fmt.Errorf("authorization error on cgidashboard.cgi")
+	}
+
+	return nil
+}
+
+func (c *client) reboot(ctx context.Context) error {
+	form := url.Values{}
+	form.Add("sReboot", "Current")
+	form.Add("submitbnt", "Reboot Now")
+	form.Add("nSch1", "0")
+	form.Add("nSch2", "0")
+	form.Add("nSch3", "0")
+	form.Add("nSch4", "0")
+	form.Add("fid", "0")
+	form.Add("webchange", "0")
+	form.Add("sFormAuthStr", c.random)
+
+	res, err := c.doRequest(ctx, strings.NewReader(form.Encode()), "POST", makeAddress("cgi-bin/reboot.cgi"), makeAddress("doc/rebootsys.sht"))
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	body, _ := io.ReadAll(res.Body)
+
+	if strings.Contains(string(body), "Authorization Error") {
+		return fmt.Errorf("authorization error on reboot.cgi")
+	}
+
+	return nil
+}
+
+func main() {
+	flag.StringVar(&flagAddress, "address", "http://192.168.1.1/", "Address of Draytek admin interface")
+	flag.StringVar(&flagUsername, "username", "admin", "Username for authenticating to the Draytek admin interface")
+	flag.StringVar(&flagPassword, "password", "", "Password for authenticating to the Draytek admin interface")
+	flag.Parse()
+
+	if flagPassword == "" {
+		log.Fatalf("-password must be specified")
+	}
+
+	ctx := context.Background()
+
+	jar, _ := cookiejar.New(nil)
+	c := client{
+		jar: jar,
+	}
+	err := c.getSession(ctx)
+	if err != nil {
+		log.Fatalf("Could not get session: %v", err)
+	}
+
+	if err := c.reboot(ctx); err != nil {
+		log.Fatalf("Reboot failed: %v", err)
+	}
+
+	log.Printf("Rebooted!")
+}