cmd/swarm: add validation for EnsAPIs configuration parameter

cmd/swarm/config.go

@@ -102,6 +102,8 @@ func buildConfig(ctx *cli.Context) (config *bzzapi.Config, err error) {
 	config = envVarsOverride(config)
 	//override settings provided by command line
 	config = cmdLineOverride(config, ctx)
+	//validate configuration parameters
+	err = validateConfig(config)
 
 	return
 }
@@ -319,6 +321,39 @@ func checkDeprecated(ctx *cli.Context) {
 	}
 }
 
+//validate configuration parameters
+func validateConfig(cfg *bzzapi.Config) (err error) {
+	for _, ensAPI := range cfg.EnsAPIs {
+		if ensAPI != "" {
+			if err := validateEnsAPIs(ensAPI); err != nil {
+				return fmt.Errorf("invalid format [tld:][contract-addr@]url for ENS API endpoint configuration %q: %v", ensAPI, err)
+			}
+		}
+	}
+	return nil
+}
+
+//validate EnsAPIs configuration parameter
+func validateEnsAPIs(s string) (err error) {
+	// missing contract address
+	if strings.HasPrefix(s, "@") {
+		return errors.New("missing contract address")
+	}
+	// missing url
+	if strings.HasSuffix(s, "@") {
+		return errors.New("missing url")
+	}
+	// missing tld
+	if strings.HasPrefix(s, ":") {
+		return errors.New("missing tld")
+	}
+	// missing url
+	if strings.HasSuffix(s, ":") {
+		return errors.New("missing url")
+	}
+	return nil
+}
+
 //print a Config as string
 func printConfig(config *bzzapi.Config) string {
 	out, err := tomlSettings.Marshal(&config)

cmd/swarm/config_test.go

@@ -457,3 +457,98 @@ func TestCmdLineOverridesFile(t *testing.T) {
 
 	node.Shutdown()
 }
+
+func TestValidateConfig(t *testing.T) {
+	for _, c := range []struct {
+		cfg *api.Config
+		err string
+	}{
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"/data/testnet/geth.ipc",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"http://127.0.0.1:1234",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"ws://127.0.0.1:1234",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"test:/data/testnet/geth.ipc",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"test:ws://127.0.0.1:1234",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"314159265dD8dbb310642f98f50C066173C1259b@/data/testnet/geth.ipc",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"314159265dD8dbb310642f98f50C066173C1259b@http://127.0.0.1:1234",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"314159265dD8dbb310642f98f50C066173C1259b@ws://127.0.0.1:1234",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"test:314159265dD8dbb310642f98f50C066173C1259b@/data/testnet/geth.ipc",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"eth:314159265dD8dbb310642f98f50C066173C1259b@http://127.0.0.1:1234",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"eth:314159265dD8dbb310642f98f50C066173C1259b@ws://127.0.0.1:12344",
+			}},
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"eth:",
+			}},
+			err: "invalid format [tld:][contract-addr@]url for ENS API endpoint configuration \"eth:\": missing url",
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"314159265dD8dbb310642f98f50C066173C1259b@",
+			}},
+			err: "invalid format [tld:][contract-addr@]url for ENS API endpoint configuration \"314159265dD8dbb310642f98f50C066173C1259b@\": missing url",
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				":314159265dD8dbb310642f98f50C066173C1259",
+			}},
+			err: "invalid format [tld:][contract-addr@]url for ENS API endpoint configuration \":314159265dD8dbb310642f98f50C066173C1259\": missing tld",
+		},
+		{
+			cfg: &api.Config{EnsAPIs: []string{
+				"@/data/testnet/geth.ipc",
+			}},
+			err: "invalid format [tld:][contract-addr@]url for ENS API endpoint configuration \"@/data/testnet/geth.ipc\": missing contract address",
+		},
+	} {
+		err := validateConfig(c.cfg)
+		if c.err != "" && err.Error() != c.err {
+			t.Errorf("expected error %q, got %q", c.err, err)
+		}
+		if c.err == "" && err != nil {
+			t.Errorf("unexpected error %q", err)
+		}
+	}
+}