fix: validate the IP address

Author: Wojteek

internal/app/ip/external_ip.go

@@ -2,6 +2,7 @@ package ip
 
 import (
 	log "github.com/sirupsen/logrus"
+	"net"
 )
 
 // Providers - the structure of the providers for fetching the external IP address
@@ -35,13 +36,13 @@ func NewExternalIP() *ExternalIP {
 }
 
 // IP gets the external IP address
-func (e *ExternalIP) IP() []byte {
+func (e *ExternalIP) IP() string {
 	for _, provider := range e.providers {
 		log.WithFields(log.Fields{
 			"provider": provider.name,
 		}).Debug("Checking an external IP address")
 
-		currentIP, err := request(provider.url)
+		responseProvider, err := request(provider.url)
 
 		if err != nil {
 			log.WithFields(log.Fields{
@@ -51,8 +52,19 @@ func (e *ExternalIP) IP() []byte {
 			continue
 		}
 
-		return currentIP
+		currentIP := net.ParseIP(string(responseProvider))
+
+		if currentIP == nil {
+			log.WithFields(log.Fields{
+				"provider": provider.name,
+				"response": responseProvider,
+			}).Error("The IP address has invalid format")
+
+			continue
+		}
+
+		return currentIP.String()
 	}
 
-	return nil
+	return ""
 }

internal/app/ip/request.go

@@ -1,7 +1,6 @@
 package ip
 
 import (
-	"io"
 	"io/ioutil"
 	"net/http"
 	"time"
@@ -23,11 +22,7 @@ func request(url string) ([]byte, error) {
 		return nil, err
 	}
 
-	defer func(r io.ReadCloser) {
-		if errReq := r.Close(); errReq != nil {
-			err = errReq
-		}
-	}(r.Body)
+	defer r.Body.Close()
 
 	return ioutil.ReadAll(r.Body)
 }

internal/app/service/cloudflare.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"net/http"
 )
@@ -72,6 +71,7 @@ func (c *Cloudflare) UpdateRecordRequest() ([]byte, error) {
 	}
 
 	body, err := c.sendRequest(data)
+
 	var payload CFRequestUpdatePayload
 
 	if err := json.Unmarshal(body, &payload); err != nil {
@@ -101,11 +101,7 @@ func (c *Cloudflare) sendRequest(data []byte) ([]byte, error) {
 		return nil, err
 	}
 
-	defer func(r io.ReadCloser) {
-		if errReq := r.Close(); errReq != nil {
-			err = errReq
-		}
-	}(r.Body)
+	defer r.Body.Close()
 
 	return ioutil.ReadAll(r.Body)
 }

internal/app/service/ovh.go

@@ -3,7 +3,6 @@ package service
 import (
 	"encoding/base64"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -38,18 +37,20 @@ func (o *OVH) UpdateRecordRequest() ([]byte, error) {
 		return nil, err
 	}
 
-	req.Header.Add("Authorization", fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", o.Credentials.Username, o.Credentials.Password)))))
+	credentials := []byte(fmt.Sprintf("%s:%s", o.Credentials.Username, o.Credentials.Password))
+
+	req.Header.Add(
+		"Authorization",
+		fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString(credentials)),
+	)
+
 	r, err := client.Do(req)
 
 	if err != nil {
 		return nil, err
 	}
 
-	defer func(r io.ReadCloser) {
-		if errReq := r.Close(); errReq != nil {
-			err = errReq
-		}
-	}(r.Body)
+	defer r.Body.Close()
 
 	if err := r.Header.Get("WWW-Authenticate"); r.StatusCode == http.StatusUnauthorized {
 		return nil, fmt.Errorf("OVH [%d]: %s", r.StatusCode, err)

internal/app/update_ip.go

@@ -3,15 +3,14 @@ package app
 import (
 	"github.com/Wojteek/dynhost/internal/app/ip"
 	log "github.com/sirupsen/logrus"
-	"strings"
 	"time"
 )
 
 // UpdateIP fetches and updates the IP when the IP was changed
 func UpdateIP(p *ServiceCommand, IPChangedFn IPChangedCallback) func() error {
 	return func() error {
 		data, _ := GetData(p.DataPath)
-		externalIP := strings.TrimSpace(string(ip.NewExternalIP().IP()))
+		externalIP := ip.NewExternalIP().IP()
 
 		if len(externalIP) == 0 {
 			return nil
@@ -25,13 +24,13 @@ func UpdateIP(p *ServiceCommand, IPChangedFn IPChangedCallback) func() error {
 			return err
 		}
 
-		var d interface{} = &Data{
+		d := &Data{
 			CurrentIP: externalIP,
 			PrevIP:    data.CurrentIP,
 			ChangedAt: time.Now(),
 		}
 
-		if _, err := d.(*Data).SaveData(p.DataPath); err != nil {
+		if _, err := d.SaveData(p.DataPath); err != nil {
 			return err
 		}