Merge pull request #27 from multiformats/feat/fqdn-normalization

Normalize domains to fqdn for resolver selection

.travis.yml

@@ -4,7 +4,7 @@ os:
 language: go
 
 go:
-  - 1.12.x
+  - 1.15.x
 
 env:
   global:

go.mod

@@ -1,5 +1,8 @@
 module github.com/multiformats/go-multiaddr-dns
 
-require github.com/multiformats/go-multiaddr v0.2.0
+require (
+	github.com/miekg/dns v1.1.41
+	github.com/multiformats/go-multiaddr v0.2.0
+)
 
-go 1.12
+go 1.15

go.sum

@@ -1,11 +1,11 @@
+github.com/miekg/dns v1.1.41 h1:WMszZWJG0XmzbK9FEmzH2TVcqYzFesusSIB41b8KHxY=
+github.com/miekg/dns v1.1.41/go.mod h1:p6aan82bvRIyn+zDIv9xYNUpwa73JcSh9BKwknJysuI=
 github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1 h1:lYpkrQH5ajf0OXOcUbGjvZxxijuBwbbmlSxLiuofa+g=
 github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1/go.mod h1:pD8RvIylQ358TN4wwqatJ8rNavkEINozVn9DtGI3dfQ=
 github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771 h1:MHkK1uRtFbVqvAgvWxafZe54+5uBxLluGylDiKgdhwo=
 github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771/go.mod h1:B5e1o+1/KgNmWrSQK08Y6Z1Vb5pwIktudl0J58iy0KM=
 github.com/mr-tron/base58 v1.1.2 h1:ZEw4I2EgPKDJ2iEw0cNmLB3ROrEmkOtXIkaG7wZg+78=
 github.com/mr-tron/base58 v1.1.2/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
-github.com/multiformats/go-multiaddr v0.1.1 h1:rVAztJYMhCQ7vEFr8FvxW3mS+HF2eY/oPbOMeS0ZDnE=
-github.com/multiformats/go-multiaddr v0.1.1/go.mod h1:aMKBKNEYmzmDmxfX88/vz+J5IU55txyt0p4aiWVohjo=
 github.com/multiformats/go-multiaddr v0.2.0 h1:lR52sFwcTCuQb6bTfnXF6zA2XfyYvyd+5a9qECv/J90=
 github.com/multiformats/go-multiaddr v0.2.0/go.mod h1:0nO36NvPpyV4QzvTLi/lafl2y95ncPj0vFwVF6k6wJ4=
 github.com/multiformats/go-multihash v0.0.8 h1:wrYcW5yxSi3dU07n5jnuS5PrNwyHy0zRHGVoUugWvXg=
@@ -18,7 +18,16 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 h1:1wopBVtVdWnn03fZelqdXTqk7U7zPQCb+T4rbU9ZEoU=
 golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 h1:qWPm9rbaAMKs8Bq/9LRpbMqxWRVUAQwMI9fVrssnTfw=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210303074136-134d130e1a04 h1:cEhElsAv9LUt9ZUUocxzWe05oFLVd+AA2nstydTeI8g=
+golang.org/x/sys v0.0.0-20210303074136-134d130e1a04/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

resolve.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"strings"
 
+	"github.com/miekg/dns"
 	ma "github.com/multiformats/go-multiaddr"
 )
 
@@ -63,23 +64,31 @@ func WithDomainResolver(domain string, rslv BasicResolver) Option {
 		if r.custom == nil {
 			r.custom = make(map[string]BasicResolver)
 		}
-		r.custom[domain] = rslv
+		fqdn := dns.Fqdn(domain)
+		r.custom[fqdn] = rslv
 		return nil
 	}
 }
 
 func (r *Resolver) getResolver(domain string) BasicResolver {
+	fqdn := dns.Fqdn(domain)
+
 	// we match left-to-right, with more specific resolvers superseding generic ones.
 	// So for a domain a.b.c, we will try a.b,c, b.c, c, and fallback to the default if
 	// there is no match
-	rslv, ok := r.custom[domain]
+	rslv, ok := r.custom[fqdn]
 	if ok {
 		return rslv
 	}
 
-	for i := strings.Index(domain, "."); i != -1; i = strings.Index(domain, ".") {
-		domain = domain[i+1:]
-		rslv, ok = r.custom[domain]
+	for i := strings.Index(fqdn, "."); i != -1; i = strings.Index(fqdn, ".") {
+		fqdn = fqdn[i+1:]
+		if fqdn == "" {
+			// the . is the default resolver
+			break
+		}
+
+		rslv, ok = r.custom[fqdn]
 		if ok {
 			return rslv
 		}