Fixed geoip lookup to check for invalid IP ranges

The geoip lookup function now returns the empty string for IP addresses
that are not present in the table. New tests for invalid IP address
lookups were added and a bug fix for checking an invalid returned index

broker/geoip.go

@@ -175,6 +175,20 @@ func GeoIPRangeClosure(key net.IP, entry GeoIPEntry) bool {
     return true
 }
 
+func GeoIPCheckRange (key net.IP, entry GeoIPEntry) bool {
+    a := key.To16()
+    b := entry.ipLow.To16()
+    c := entry.ipHigh.To16()
+
+    for i, v := range a {
+        if v < b[i] || v > c[i] {
+            return false
+        }
+    }
+
+    return true
+}
+
 //Returns the country location of an IPv4 or IPv6 address.
 func GetCountryByAddr(table GeoIPTable, addr string) string {
     //translate addr string to IP
@@ -185,7 +199,15 @@ func GetCountryByAddr(table GeoIPTable, addr string) string {
         return GeoIPRangeClosure(ip, table.ElementAt(i))
     })
 
-    if index == -1 {
+    if index == table.Len() {
+        return ""
+    }
+
+    // check to see if addr is in the range specified by the returned index
+    // search on IPs in invalid ranges (e.g., 127.0.0.0/8) will return the
+    //country code of the next highest range
+    log.Println("Checking index ", index)
+    if ! GeoIPCheckRange(ip, table.ElementAt(index)) {
         return ""
     }
 

broker/metrics.go

@@ -43,7 +43,9 @@ func (m Metrics) UpdateCountryStats(addr string) {
     }
 
     //update map of countries and counts
-    m.countryStats.counts[country] = m.countryStats.counts[country] + 1
+    if country != "" {
+        m.countryStats.counts[country] = m.countryStats.counts[country] + 1
+    }
 
 }
 

broker/snowflake-broker_test.go

@@ -278,7 +278,14 @@ func TestGeoip(t *testing.T) {
             err = GeoIPLoadFile(tv6, "./geoip6")
             So(err, ShouldEqual, nil)
 
-            So(GetCountryByAddr(tv4, "129.97.208.23"), ShouldEqual, "CA")
+            So(GetCountryByAddr(tv4, "129.97.208.23"), ShouldEqual, "CA") //University of Waterloo
+            So(GetCountryByAddr(tv4, "127.0.0.1"), ShouldEqual, "")
+            So(GetCountryByAddr(tv4, "0.0.0.0"), ShouldEqual, "")
+            So(GetCountryByAddr(tv4, "255.255.255.255"), ShouldEqual, "")
+
             So(GetCountryByAddr(tv6, "2620:101:f000:0:250:56ff:fe80:168e"), ShouldEqual, "CA")
+            So(GetCountryByAddr(tv6, "fd00:0:0:0:0:0:0:1"), ShouldEqual, "")
+            So(GetCountryByAddr(tv6, "0:0:0:0:0:0:0:0"), ShouldEqual, "")
+            So(GetCountryByAddr(tv6, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"), ShouldEqual, "")
         })
     }