[#11] Add dns, nns resolver

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

go.sum

@@ -5,9 +5,12 @@ github.com/CityOfZion/neo-go v0.62.1-pre.0.20191114145240-e740fbe708f8/go.mod h1
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@@ -19,8 +22,11 @@ github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRF
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@@ -30,6 +36,7 @@ github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLj
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@@ -45,8 +52,10 @@ github.com/btcsuite/snappy-go v1.0.0/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg
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@@ -66,9 +75,13 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
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@@ -83,6 +96,7 @@ github.com/fatih/color v1.12.0/go.mod h1:ELkj/draVOlAH/xkhN6mQ50Qd0MPOk5AAr3maGE
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@@ -92,6 +106,7 @@ github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9
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@@ -116,6 +131,7 @@ github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaS
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@@ -131,6 +147,7 @@ github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+
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@@ -166,6 +183,7 @@ github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hd
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@@ -204,16 +222,19 @@ github.com/nspcc-dev/neofs-crypto v0.3.0/go.mod h1:8w16GEJbH6791ktVqHN9YRNH3s9BE
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 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.5/go.mod h1:4A/X28fw3Fc593LaREMrKMqOKvUAntwMDaekg4FpcdQ=
 github.com/prometheus/procfs v0.1.3/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
+github.com/prometheus/procfs v0.6.0 h1:mxy4L2jP6qMonqmq+aTtOx1ifVWUgG/TAmntgbh3xv4=
 github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
@@ -269,6 +294,7 @@ github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/syndtr/goleveldb v0.0.0-20180307113352-169b1b37be73/go.mod h1:Z4AUp2Km+PwemOoO/VB5AOx9XSsIItzFjoJlOSiYmn0=
+github.com/syndtr/goleveldb v1.0.1-0.20210305035536-64b5b1c73954 h1:xQdMZ1WLrgkkvOZ/LDQxjVxMLdby7osSh4ZEVa5sIjs=
 github.com/syndtr/goleveldb v1.0.1-0.20210305035536-64b5b1c73954/go.mod h1:u2MKkTVTVJWe5D1rCvame8WqhBd88EuIwODJZ1VHCPM=
 github.com/tinylib/msgp v1.1.5/go.mod h1:eQsjooMTnV42mHu917E26IogZ2930nFyBQdofk10Udg=
 github.com/ttacon/chalk v0.0.0-20160626202418-22c06c80ed31/go.mod h1:onvgF043R+lC5RZ8IT9rBXDaEDnpnw/Cl+HFiw+v/7Q=
@@ -276,15 +302,18 @@ github.com/twmb/murmur3 v1.1.5/go.mod h1:Qq/R7NUyOfr65zD+6Q5IHKsJLwP7exErjN6lyyq
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
 github.com/urfave/cli v1.22.5/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
+github.com/virtuald/go-ordered-json v0.0.0-20170621173500-b18e6e673d74 h1:JwtAtbp7r/7QSyGz8mKUbYJBg2+6Cd7OjM8o/GNOcVo=
 github.com/virtuald/go-ordered-json v0.0.0-20170621173500-b18e6e673d74/go.mod h1:RmMWU37GKR2s6pgrIEB4ixgpVCt/cf7dnJv3fuH1J1c=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/yuin/gopher-lua v0.0.0-20190514113301-1cd887cd7036/go.mod h1:gqRgreBUhTSL0GeU64rtZ3Uq3wtjOa/TB2YfrtkCbVQ=
 github.com/yuin/gopher-lua v0.0.0-20191128022950-c6266f4fe8d7/go.mod h1:gqRgreBUhTSL0GeU64rtZ3Uq3wtjOa/TB2YfrtkCbVQ=
+github.com/yuin/gopher-lua v0.0.0-20200816102855-ee81675732da h1:NimzV1aGyq29m5ukMK0AMWEhFaL/lrEOaephfuoiARg=
 github.com/yuin/gopher-lua v0.0.0-20200816102855-ee81675732da/go.mod h1:E1AXubJBdNmFERAOucpDIxNzeGfLzg0mYh+UfMWdChA=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.etcd.io/bbolt v1.3.4/go.mod h1:G5EMThwa9y8QZGBClrRx5EY+Yw9kAhnjy3bSjsnlVTQ=
+go.etcd.io/bbolt v1.3.6 h1:/ecaJf0sk1l4l6V4awd65v2C3ILy7MSj+s/x1ADCIMU=
 go.etcd.io/bbolt v1.3.6/go.mod h1:qXsaaIqmgQH0T+OPdb99Bf+PKfBBQVAdyD6TY9G8XM4=
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
@@ -348,6 +377,7 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+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 v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -450,6 +480,7 @@ gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

resolver/dns.go

@@ -0,0 +1,41 @@
+package resolver
+
+import (
+	"fmt"
+	"net"
+
+	cid "github.com/nspcc-dev/neofs-sdk-go/container/id"
+)
+
+const (
+	testnetDomain = ".containers.testnet.fs.neo.org"
+	mainnetDomain = ".containers.fs.neo.org"
+)
+
+// ResolveContainerTestnet request txt record name + '.containers.testnet.fs.neo.org' to default dns server.
+func ResolveContainerTestnet(name string) (*cid.ID, error) {
+	return ResolveContainerDomainName(name + testnetDomain)
+}
+
+// ResolveContainerMainnet request txt record name + '.containers.fs.neo.org' to default dns server.
+func ResolveContainerMainnet(name string) (*cid.ID, error) {
+	return ResolveContainerDomainName(name + mainnetDomain)
+}
+
+// ResolveContainerDomainName trys to resolve container domain name to container ID using system dns server.
+func ResolveContainerDomainName(domain string) (*cid.ID, error) {
+	results, err := net.LookupTXT(domain)
+	if err != nil {
+		return nil, err
+	}
+
+	cnrID := cid.New()
+	for _, res := range results {
+		if err = cnrID.Parse(res); err != nil {
+			continue
+		}
+		return cnrID, nil
+	}
+
+	return nil, fmt.Errorf("not found")
+}

resolver/nns.go

@@ -0,0 +1,130 @@
+package resolver
+
+import (
+	"context"
+	"fmt"
+
+	nns "github.com/nspcc-dev/neo-go/examples/nft-nd-nns"
+	"github.com/nspcc-dev/neo-go/pkg/rpc/client"
+	"github.com/nspcc-dev/neo-go/pkg/rpc/response/result"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
+	cid "github.com/nspcc-dev/neofs-sdk-go/container/id"
+)
+
+type NNSResolver interface {
+	// ResolveContainerName get record for domain name+'.container' from NNS contract.
+	ResolveContainerName(name string) (*cid.ID, error)
+}
+
+type nnsResolver struct {
+	rpc     *client.Client
+	nnsHash util.Uint160
+}
+
+const (
+	resolve         = "resolve"
+	containerDomain = ".container"
+)
+
+// NewNNSResolver creates resolver that can get records from NNS contract.
+func NewNNSResolver(ctx context.Context, address string) (NNSResolver, error) {
+	rpc, err := client.New(ctx, address, client.Options{})
+	if err != nil {
+		return nil, err
+	}
+	if err = rpc.Init(); err != nil {
+		return nil, err
+	}
+
+	nnsContract, err := rpc.GetContractStateByID(1)
+	if err != nil {
+		return nil, err
+	}
+
+	return &nnsResolver{
+		rpc:     rpc,
+		nnsHash: nnsContract.Hash,
+	}, nil
+}
+
+func (n *nnsResolver) ResolveContainerName(name string) (*cid.ID, error) {
+	res, err := n.rpc.InvokeFunction(n.nnsHash, resolve, []smartcontract.Parameter{
+		{
+			Type:  smartcontract.StringType,
+			Value: name + containerDomain,
+		},
+		{
+			Type:  smartcontract.IntegerType,
+			Value: int64(nns.TXT),
+		},
+	}, nil)
+	if err != nil {
+		return nil, err
+	}
+	if err = getInvocationError(res); err != nil {
+		return nil, err
+	}
+
+	arr, err := getArrString(res.Stack)
+	if err != nil {
+		return nil, err
+	}
+
+	cnrID := cid.New()
+	for _, rec := range arr {
+		if err = cnrID.Parse(rec); err != nil {
+			continue
+		}
+		return cnrID, nil
+	}
+
+	return nil, fmt.Errorf("not found")
+}
+
+func getArrString(st []stackitem.Item) ([]string, error) {
+	array, err := getArray(st)
+	if err != nil {
+		return nil, err
+	}
+
+	res := make([]string, len(array))
+	for i, item := range array {
+		bs, err := item.TryBytes()
+		if err != nil {
+			return nil, err
+		}
+		res[i] = string(bs)
+	}
+
+	return res, nil
+}
+
+func getArray(st []stackitem.Item) ([]stackitem.Item, error) {
+	index := len(st) - 1 // top stack element is last in the array
+	arr, err := st[index].Convert(stackitem.ArrayT)
+	if err != nil {
+		return nil, err
+	}
+	if _, ok := arr.(stackitem.Null); ok {
+		return nil, nil
+	}
+
+	iterator, ok := arr.Value().([]stackitem.Item)
+	if !ok {
+		return nil, fmt.Errorf("bad conversion")
+	}
+	return iterator, nil
+}
+
+func getInvocationError(result *result.Invoke) error {
+	if result.State != vm.HaltState.String() {
+		return fmt.Errorf("invocation failed: %s", result.FaultException)
+	}
+	if len(result.Stack) == 0 {
+		return fmt.Errorf("result stack is empty")
+	}
+	return nil
+}