From 6a9202851d0df6b47a4eedfa9566fcf6a3b473cb Mon Sep 17 00:00:00 2001
From: Martin Polden <martin.polden@gmail.com>
Date: Wed, 6 Jul 2016 23:44:33 +0200
Subject: [PATCH] Include IP in decimal format

Fixes #19
---
 README.md       |  3 ++-
 api/api.go      | 30 ++++++++++++++++++++++--------
 api/api_test.go | 19 ++++++++++++++++++-
 index.html      |  3 ++-
 4 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index 5958027..3cffea3 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,8 @@ $ http --json ifconfig.co
 {
   "city": "Bornyasherk",
   "country": "Elbonia",
-  "ip": "127.0.0.1"
+  "ip": "127.0.0.1",
+  "ip_decimal": 2130706433
 }
 ```
 
diff --git a/api/api.go b/api/api.go
index 5a6d49e..9f44c0f 100644
--- a/api/api.go
+++ b/api/api.go
@@ -6,6 +6,7 @@ import (
 	"html/template"
 	"io"
 	"log"
+	"math/big"
 	"net"
 	"net/http"
 	"path/filepath"
@@ -29,10 +30,11 @@ type API struct {
 }
 
 type Response struct {
-	IP       net.IP `json:"ip"`
-	Country  string `json:"country,omitempty"`
-	City     string `json:"city,omitempty"`
-	Hostname string `json:"hostname,omitempty"`
+	IP        net.IP   `json:"ip"`
+	IPDecimal *big.Int `json:"ip_decimal"`
+	Country   string   `json:"country,omitempty"`
+	City      string   `json:"city,omitempty"`
+	Hostname  string   `json:"hostname,omitempty"`
 }
 
 type PortResponse struct {
@@ -45,6 +47,16 @@ func New(oracle Oracle) *API {
 	return &API{oracle: oracle}
 }
 
+func ipToDecimal(ip net.IP) *big.Int {
+	i := big.NewInt(0)
+	if to4 := ip.To4(); to4 != nil {
+		i.SetBytes(to4)
+	} else {
+		i.SetBytes(ip)
+	}
+	return i
+}
+
 func ipFromRequest(header string, r *http.Request) (net.IP, error) {
 	remoteIP := r.Header.Get(header)
 	if remoteIP == "" {
@@ -66,6 +78,7 @@ func (a *API) newResponse(r *http.Request) (Response, error) {
 	if err != nil {
 		return Response{}, err
 	}
+	ipDecimal := ipToDecimal(ip)
 	country, err := a.oracle.LookupCountry(ip)
 	if err != nil {
 		log.Print(err)
@@ -79,10 +92,11 @@ func (a *API) newResponse(r *http.Request) (Response, error) {
 		log.Print(err)
 	}
 	return Response{
-		IP:       ip,
-		Country:  country,
-		City:     city,
-		Hostname: strings.Join(hostnames, " "),
+		IP:        ip,
+		IPDecimal: ipDecimal,
+		Country:   country,
+		City:      city,
+		Hostname:  strings.Join(hostnames, " "),
 	}, nil
 }
 
diff --git a/api/api_test.go b/api/api_test.go
index 8de94e2..42e5075 100644
--- a/api/api_test.go
+++ b/api/api_test.go
@@ -3,6 +3,7 @@ package api
 import (
 	"io/ioutil"
 	"log"
+	"math/big"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -84,7 +85,7 @@ func TestJSONHandlers(t *testing.T) {
 		out    string
 		status int
 	}{
-		{s.URL, `{"ip":"127.0.0.1","country":"Elbonia","city":"Bornyasherk","hostname":"localhost"}`, 200},
+		{s.URL, `{"ip":"127.0.0.1","ip_decimal":2130706433,"country":"Elbonia","city":"Bornyasherk","hostname":"localhost"}`, 200},
 		{s.URL + "/port/foo", `{"error":"404 page not found"}`, 404},
 		{s.URL + "/port/0", `{"error":"Invalid port: 0"}`, 400},
 		{s.URL + "/port/65356", `{"error":"Invalid port: 65356"}`, 400},
@@ -161,3 +162,19 @@ func TestCLIMatcher(t *testing.T) {
 		}
 	}
 }
+
+func TestIPToDecimal(t *testing.T) {
+	var tests = []struct {
+		in  string
+		out *big.Int
+	}{
+		{"127.0.0.1", big.NewInt(2130706433)},
+		{"::1", big.NewInt(1)},
+	}
+	for _, tt := range tests {
+		i := ipToDecimal(net.ParseIP(tt.in))
+		if i.Cmp(tt.out) != 0 {
+			t.Errorf("Expected %d, got %d for IP %s", tt.out, i, tt.in)
+		}
+	}
+}
diff --git a/index.html b/index.html
index a0f0d05..44d3a5c 100644
--- a/index.html
+++ b/index.html
@@ -80,7 +80,8 @@ $ http ifconfig.co/json
     "city": "{{ .City }}",{{ end }}{{ if .IsLookupCountryEnabled }}
     "country": "{{ .Country }}",{{ end }}{{ if .IsLookupAddrEnabled }}
     "hostname": "{{ .Hostname }}",{{ end }}
-    "ip": "{{ .IP }}"
+    "ip": "{{ .IP }}",
+    "ip_decimal": {{ .IPDecimal }}
 }
 
 # or set Accept header: