initial commit

utils/dns_utils.go

@@ -0,0 +1,31 @@
+// dns utils
+package utils
+
+import (
+	"github.com/miekg/dns"
+)
+
+// build the question section of a dns packet
+func QuestionMaker(domain string, qclass uint16, qtype uint16) *dns.Question {
+	return &dns.Question{Name: dns.Fqdn(domain), Qtype: qtype, Qclass: qclass}
+}
+
+// build a specific query message
+func QueryMaker(domain string, rd bool, qclass uint16, qtype uint16, edns bool) *dns.Msg {
+	msg := new(dns.Msg)
+	msg.Id = dns.Id()
+	msg.RecursionDesired = rd
+	msg.Question = make([]dns.Question, 1)
+	msg.Question[0] = *QuestionMaker(domain, qclass, qtype)
+	if edns {
+		msg = msg.SetEdns0(4096, false)
+	}
+	return msg
+}
+
+// query and receive the response
+func DNSQuery(addr string, domain string, rd bool, qclass uint16, qtype uint16, edns bool) (*dns.Msg, error) {
+	msg := QueryMaker(domain, rd, qclass, qtype, edns)
+	res, err := dns.Exchange(msg, addr)
+	return res, err
+}

utils/other_utils.go

@@ -0,0 +1,68 @@
+package utils
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+type ResolverBehavior struct {
+	Dnssec        bool  `json:"dnssec"`
+	QnameEncode   bool  `json:"0x20"`
+	QueryMerge    int   `json:"merge_dup"`
+	MaxNsDepth    int   `json:"max_ns_depth"`
+	MaxCnameDepth int   `json:"max_cname_depth"`
+	RetryLimit    int   `json:"retry_limit"`
+	FetchLimit    int   `json:"fetch_limit"`
+	TimeoutStart  int64 `json:"timeout_start"`
+	TimeoutEnd    int64 `json:"timeout_end"`
+}
+
+func IsValidIP(ip string) bool {
+	res := net.ParseIP(ip)
+	return res != nil
+}
+
+func IPv4ToInt(ip string) (uint32, error) {
+	if !IsValidIP(ip) {
+		return 0, fmt.Errorf("invalid IP address: %s", ip)
+	}
+	labels := strings.Split(ip, ".")
+	var result uint32
+	for _, label := range labels {
+		label_val, _ := strconv.Atoi(label)
+		result = (result << 8) | uint32(label_val)
+	}
+	return result, nil
+}
+
+func GetResult(addr string, token int) (*ResolverBehavior, error) {
+	data := new(ResolverBehavior)
+	url := "http://" + addr + "/results/" + strconv.Itoa(token)
+	response, err := http.Get(url)
+	if err != nil {
+		return data, err
+	}
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		return data, fmt.Errorf("wrong HTTP status code : %v", response.StatusCode)
+	}
+
+	err = json.NewDecoder(response.Body).Decode(data)
+	if err != nil {
+		return data, err
+	}
+	return data, nil
+}
+
+func OutputJson(data interface{}) (string, error) {
+	json_byte, err := json.Marshal(data)
+	if err != nil {
+		return "", err
+	}
+	return string(json_byte), nil
+}