Merge pull request #4977 from ipfs/fix/4973-1

only resolve dnslinks once in the gateway

core/corehttp/gateway_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"io/ioutil"
+	"math"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -31,11 +32,25 @@ var emptyDir = "/ipfs/QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn"
 type mockNamesys map[string]path.Path
 
 func (m mockNamesys) Resolve(ctx context.Context, name string, opts ...nsopts.ResolveOpt) (value path.Path, err error) {
-	p, ok := m[name]
-	if !ok {
-		return "", namesys.ErrResolveFailed
+	cfg := nsopts.DefaultResolveOpts()
+	for _, o := range opts {
+		o(cfg)
 	}
-	return p, nil
+	depth := cfg.Depth
+	if depth == nsopts.UnlimitedDepth {
+		depth = math.MaxUint64
+	}
+	for depth > 0 && strings.HasPrefix(name, "/ipns/") {
+		depth--
+
+		var ok bool
+		value, ok = m[name]
+		if !ok {
+			return "", namesys.ErrResolveFailed
+		}
+		name = value.String()
+	}
+	return value, nil
 }
 
 func (m mockNamesys) Publish(ctx context.Context, name ci.PrivKey, value path.Path) error {
@@ -130,6 +145,10 @@ func TestGatewayGet(t *testing.T) {
 		t.Fatal(err)
 	}
 	ns["/ipns/example.com"] = path.FromString("/ipfs/" + k)
+	ns["/ipns/working.example.com"] = path.FromString("/ipfs/" + k)
+	ns["/ipns/double.example.com"] = path.FromString("/ipns/working.example.com")
+	ns["/ipns/triple.example.com"] = path.FromString("/ipns/double.example.com")
+	ns["/ipns/broken.example.com"] = path.FromString("/ipns/" + k)
 
 	t.Log(ts.URL)
 	for _, test := range []struct {
@@ -145,6 +164,13 @@ func TestGatewayGet(t *testing.T) {
 		{"localhost:5001", "/ipns/%0D%0A%0D%0Ahello", http.StatusNotFound, "ipfs resolve -r /ipns/%0D%0A%0D%0Ahello: " + namesys.ErrResolveFailed.Error() + "\n"},
 		{"localhost:5001", "/ipns/example.com", http.StatusOK, "fnord"},
 		{"example.com", "/", http.StatusOK, "fnord"},
+
+		{"working.example.com", "/", http.StatusOK, "fnord"},
+		{"double.example.com", "/", http.StatusOK, "fnord"},
+		{"triple.example.com", "/", http.StatusOK, "fnord"},
+		{"working.example.com", "/ipfs/" + k, http.StatusNotFound, "ipfs resolve -r /ipns/working.example.com/ipfs/" + k + ": no link named \"ipfs\" under " + k + "\n"},
+		{"broken.example.com", "/", http.StatusNotFound, "ipfs resolve -r /ipns/broken.example.com/: " + namesys.ErrResolveFailed.Error() + "\n"},
+		{"broken.example.com", "/ipfs/" + k, http.StatusNotFound, "ipfs resolve -r /ipns/broken.example.com/ipfs/" + k + ": " + namesys.ErrResolveFailed.Error() + "\n"},
 	} {
 		var c http.Client
 		r, err := http.NewRequest("GET", ts.URL+test.path, nil)

core/corehttp/ipns_hostname.go

@@ -6,7 +6,8 @@ import (
 	"net/http"
 	"strings"
 
-	"github.com/ipfs/go-ipfs/core"
+	core "github.com/ipfs/go-ipfs/core"
+	nsopts "github.com/ipfs/go-ipfs/namesys/opts"
 
 	isd "gx/ipfs/QmZmmuAXgX73UQmX1jRKjTGmjzq24Jinqkq8vzkBtno4uX/go-is-domain"
 )
@@ -24,7 +25,7 @@ func IPNSHostnameOption() ServeOption {
 			host := strings.SplitN(r.Host, ":", 2)[0]
 			if len(host) > 0 && isd.IsDomain(host) {
 				name := "/ipns/" + host
-				if _, err := n.Namesys.Resolve(ctx, name); err == nil {
+				if _, err := n.Namesys.Resolve(ctx, name, nsopts.Depth(1)); err == nil {
 					r.Header["X-Ipns-Original-Path"] = []string{r.URL.Path}
 					r.URL.Path = name + r.URL.Path
 				}