minor changes in api.go, checkip.go, dns.go, shodan.go

api.go

@@ -24,11 +24,13 @@ func makeAPIcall(apiurl string, headers map[string]string, queryParams map[strin
 	}
 
 	// Set query parameters.
-	vals := url.Values{}
-	for k, v := range queryParams {
-		vals.Add(k, v)
+	if len(queryParams) != 0 {
+		vals := url.Values{}
+		for k, v := range queryParams {
+			vals.Add(k, v)
+		}
+		apiURL.RawQuery = vals.Encode()
 	}
-	apiURL.RawQuery = vals.Encode()
 
 	req, err := http.NewRequest("GET", apiURL.String(), nil)
 	if err != nil {

checkip.go

@@ -3,10 +3,17 @@ package checkip
 
 import (
 	"fmt"
+	"log"
 	"net"
+	"os"
 	"sync"
 )
 
+func init() {
+	log.SetFlags(0)
+	log.SetPrefix(os.Args[0] + ": ")
+}
+
 // Checker checks an IP address. ok is false if it considers the IP address to
 // be suspicious. If the check fails (err != nil), ok must be true - presumption
 // of innocence. Checker can be printed to see what it has found about the IP
@@ -25,13 +32,17 @@ func Run(checkers []Checker, ipaddr net.IP) int {
 	for _, checker := range checkers {
 		wg.Add(1)
 		go func(checker Checker) {
+			defer wg.Done()
 			ok, err := checker.Check(ipaddr)
-			if err == nil && !ok {
+			if err != nil {
+				log.Print(err)
+				return
+			}
+			if !ok {
 				mu.Lock()
 				suspicious++
 				mu.Unlock()
 			}
-			wg.Done()
 		}(checker)
 	}
 	wg.Wait()

dns.go

@@ -13,10 +13,9 @@ type DNS struct {
 
 // Check does a reverse lookup for a given IP address.
 func (d *DNS) Check(ipaddr net.IP) (bool, error) {
-	names, err := net.LookupAddr(ipaddr.String())
-	if err != nil {
-		return true, err
-	}
+	// We are ignoring error. It says: nodename nor servname provided, or
+	// not known
+	names, _ := net.LookupAddr(ipaddr.String())
 	d.Names = names
 	return true, nil
 }

shodan.go

@@ -38,8 +38,9 @@ func (s *Shodan) Check(ipaddr net.IP) (bool, error) {
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode != http.StatusOK {
-		return true, fmt.Errorf("calling API: %s", resp.Status)
+	// StatusNotFound is returned when shodan doesn't know the IP address.
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNotFound {
+		return true, fmt.Errorf("calling %s: %s", apiURL, resp.Status)
 	}
 
 	if err := json.NewDecoder(resp.Body).Decode(&s); err != nil {