feat: Handle NAT64 address query (#200)

We can query the NAT64 address by the IPv4 address part of the NAT64 address. This is useful when we want to know the NAT64 address of a specific IPv4 address. We also add a new regex pattern to match the NAT64 address like 64:ff9b::1.1.1.1 . Signed-off-by: Yangyu Chen <[email protected]>
zu1k · Dec 30, 2024 · 8c17abb · 8c17abb
1 parent 2e758d3
commit 8c17abb
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diff --git a/internal/db/db.go b/internal/db/db.go
@@ -2,6 +2,7 @@ package db
 
 import (
 	"log"
+	"net"
 
 	"github.com/spf13/viper"
 
@@ -72,6 +73,19 @@ func Find(typ dbif.QueryType, query string) *Result {
 	if result, found := queryCache.Load(query); found {
 		return result.(*Result)
 	}
+	// Convert NAT64 64:ff9b::/96 to IPv4
+	if typ == dbif.TypeIPv6 {
+		ip := net.ParseIP(query)
+		if ip != nil {
+			_, NAT64, _ := net.ParseCIDR("64:ff9b::/96")
+			if NAT64.Contains(ip) {
+				ip4 := make(net.IP, 4)
+				copy(ip4, ip[12:16])
+				query = ip4.String()
+				typ = dbif.TypeIPv4
+			}
+		}
+	}
 	db := GetDB(typ)
 	result, err := db.Find(query)
 	if err != nil {

diff --git a/pkg/re/re.go b/pkg/re/re.go
@@ -9,7 +9,7 @@ var (
 	DomainRe = regexp.MustCompile(`([a-zA-Z0-9][-a-zA-Z0-9]{0,62}\.)+([a-zA-Z][-a-zA-Z]{0,62})`)
 
 	IPv4Re = regexp.MustCompile(`(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}`)
-	IPv6Re = regexp.MustCompile(`fe80:(:[0-9a-fA-F]{1,4}){0,4}(%\w+)?|([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|::[fF]{4}:(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}|(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?::(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?`)
+	IPv6Re = regexp.MustCompile(`fe80:(:[0-9a-fA-F]{1,4}){0,4}(%\w+)?|([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}|64:ff9b::(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}|::[fF]{4}:(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}|(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?::(([0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4})?`)
 )
 
 func MaybeRegexp(s string) bool {