maxmind

server.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+)
+
+var invalidIPBytes = []byte("Please provide a valid IP address.")
+
+// Struct to hold IP data
+type dataStruct struct {
+	IP        *string `json:"ip"`
+	Hostname  *string `json:"hostname"`
+	ASN       *string `json:"asn"`
+	Org       *string `json:"org"`
+	City      *string `json:"city"`
+	Region    *string `json:"region"`
+	Country   *string `json:"country"`
+	Continent *string `json:"continent"`
+	Loc       *string `json:"loc"`
+}
+
+type bogonDataStruct struct {
+	IP    string `json:"ip"`
+	Bogon bool   `json:"bogon"`
+}
+
+func startServer() {
+	log.Println("Server listening on :3000")
+	http.HandleFunc("/", handler)
+	log.Fatal(http.ListenAndServe(":3000", nil))
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	requestedThings := strings.Split(r.URL.Path, "/")
+
+	var IPAddress, field string
+	if len(requestedThings) > 1 && net.ParseIP(requestedThings[1]) != nil {
+		IPAddress = requestedThings[1]
+		if len(requestedThings) > 2 {
+			field = requestedThings[2]
+		}
+	} else if len(requestedThings) > 1 {
+		field = requestedThings[1]
+	}
+
+	if IPAddress == "" || IPAddress == "self" {
+		IPAddress = getRealIP(r)
+	}
+	ip := net.ParseIP(IPAddress)
+	if ip == nil {
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		w.Write(invalidIPBytes)
+		return
+	}
+
+	if isBogon(ip) {
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		bogonData := bogonDataStruct{
+			IP:    ip.String(),
+			Bogon: true,
+		}
+		json.NewEncoder(w).Encode(bogonData)
+		return
+	}
+
+	data := lookupIPData(ip)
+	if data == nil {
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		w.Write(invalidIPBytes)
+		return
+	}
+
+	if field != "" {
+		value := getField(data, field)
+		if value != nil {
+			w.Header().Set("Content-Type", "application/json; charset=utf-8")
+			json.NewEncoder(w).Encode(map[string]*string{field: value})
+			return
+		} else {
+			w.Header().Set("Content-Type", "application/json; charset=utf-8")
+			json.NewEncoder(w).Encode(map[string]*string{field: nil})
+			return
+		}
+	}
+
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	callback := r.URL.Query().Get("callback")
+	enableJSONP := callback != "" && len(callback) < 2000 && callbackJSONP.MatchString(callback)
+	if enableJSONP {
+		jsonData, _ := json.MarshalIndent(data, "", "  ")
+		response := fmt.Sprintf("/**/ typeof %s === 'function' && %s(%s);", callback, callback, jsonData)
+		w.Write([]byte(response))
+	} else {
+		enc := json.NewEncoder(w)
+		enc.SetIndent("", "  ")
+		if r.URL.Query().Get("compact") == "true" {
+			enc.SetIndent("", "")
+		}
+		enc.Encode(data)
+	}
+}
+
+// Get specific field from dataStruct
+func getField(data *dataStruct, field string) *string {
+	switch field {
+	case "ip":
+		return data.IP
+	case "hostname":
+		return data.Hostname
+	case "asn":
+		return data.ASN
+	case "org":
+		return data.Org
+	case "city":
+		return data.City
+	case "region":
+		return data.Region
+	case "country":
+		return data.Country
+	case "continent":
+		return data.Continent
+	case "loc":
+		return data.Loc
+	default:
+		return nil
+	}
+}