ir: Add node info attribute uniqueness validation

That is the API restriction. Add this check to the `maddress` validator and
rename in to `structure` validator.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

Author: carpawell

pkg/innerring/innerring.go

@@ -24,8 +24,8 @@ import (
 	"github.com/nspcc-dev/neofs-node/pkg/innerring/processors/netmap"
 	nodevalidator "github.com/nspcc-dev/neofs-node/pkg/innerring/processors/netmap/nodevalidation"
 	availabilityvalidator "github.com/nspcc-dev/neofs-node/pkg/innerring/processors/netmap/nodevalidation/availability"
-	addrvalidator "github.com/nspcc-dev/neofs-node/pkg/innerring/processors/netmap/nodevalidation/maddress"
 	statevalidation "github.com/nspcc-dev/neofs-node/pkg/innerring/processors/netmap/nodevalidation/state"
+	addrvalidator "github.com/nspcc-dev/neofs-node/pkg/innerring/processors/netmap/nodevalidation/structure"
 	"github.com/nspcc-dev/neofs-node/pkg/innerring/processors/reputation"
 	"github.com/nspcc-dev/neofs-node/pkg/innerring/processors/settlement"
 	auditSettlement "github.com/nspcc-dev/neofs-node/pkg/innerring/processors/settlement/audit"

pkg/innerring/processors/netmap/nodevalidation/maddress/calls.go pkg/innerring/processors/netmap/nodevalidation/structure/calls.go

@@ -1,4 +1,4 @@
-package maddress
+package structure
 
 import (
 	"fmt"
@@ -14,5 +14,12 @@ func (v *Validator) VerifyAndUpdate(n *netmap.NodeInfo) error {
 		return fmt.Errorf("could not verify multiaddress: %w", err)
 	}
 
-	return nil
+	attrM := make(map[string]struct{}, n.NumberOfAttributes())
+	n.IterateAttributes(func(key, _ string) {
+		if _, alreadyHave := attrM[key]; alreadyHave {
+			err = fmt.Errorf("repeating node attribute: '%s'", key)
+		}
+	})
+
+	return err
 }

pkg/innerring/processors/netmap/nodevalidation/maddress/validator.go pkg/innerring/processors/netmap/nodevalidation/structure/validator.go

@@ -1,7 +1,7 @@
-package maddress
+package structure
 
-// Validator is an utility that verifies node
-// multiaddress.
+// Validator is a utility that verifies announced node
+// structure.
 //
 // For correct operation, the Validator must be created
 // using the constructor (New). After successful creation,