frostfs-contract/nns/nns_contract.go

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/*
Package nns contains non-divisible non-fungible NEP11-compatible token
implementation. This token is a compatible analogue of C# Neo Name Service
token and is aimed to serve as a domain name service for Neo smart-contracts,
thus it's NeoNameService. This token can be minted with new domain name
registration, the domain name itself is your NFT. Corresponding domain root
must be added by committee before a new domain name can be registered.
*/
package nns
import (
"github.com/nspcc-dev/neo-go/pkg/interop"
"github.com/nspcc-dev/neo-go/pkg/interop/contract"
"github.com/nspcc-dev/neo-go/pkg/interop/iterator"
"github.com/nspcc-dev/neo-go/pkg/interop/native/crypto"
"github.com/nspcc-dev/neo-go/pkg/interop/native/management"
"github.com/nspcc-dev/neo-go/pkg/interop/native/neo"
"github.com/nspcc-dev/neo-go/pkg/interop/native/std"
"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
"github.com/nspcc-dev/neo-go/pkg/interop/storage"
"github.com/nspcc-dev/neo-go/pkg/interop/util"
"github.com/nspcc-dev/neofs-contract/common"
)
// Prefixes used for contract data storage.
const (
// prefixTotalSupply contains total supply of minted domains.
prefixTotalSupply byte = 0x00
// prefixBalance contains map from the owner to their balance.
prefixBalance byte = 0x01
// prefixAccountToken contains map from (owner + token key) to token ID,
// where token key = hash160(token ID) and token ID = domain name.
prefixAccountToken byte = 0x02
// prefixRegisterPrice contains price for new domain name registration.
prefixRegisterPrice byte = 0x10
// prefixRoot contains set of roots (map from root to 0).
prefixRoot byte = 0x20
// prefixName contains map from token key to token where token is domain
// NameState structure.
prefixName byte = 0x21
// prefixRecord contains map from (token key + hash160(token name) + record type)
// to record.
prefixRecord byte = 0x22
)
// Values constraints.
const (
// maxRegisterPrice is the maximum price of register method.
maxRegisterPrice = int64(1_0000_0000_0000)
// maxRootLength is the maximum domain root length.
maxRootLength = 16
// maxDomainNameFragmentLength is the maximum length of the domain name fragment.
maxDomainNameFragmentLength = 63
// minDomainNameLength is minimum domain length.
minDomainNameLength = 3
// maxDomainNameLength is maximum domain length.
maxDomainNameLength = 255
// maxTXTRecordLength is the maximum length of the TXT domain record.
maxTXTRecordLength = 255
)
// Other constants.
const (
// defaultRegisterPrice is the default price for new domain registration.
defaultRegisterPrice = 10_0000_0000
// millisecondsInYear is amount of milliseconds per year.
millisecondsInYear = int64(365 * 24 * 3600 * 1000)
)
// RecordState is a type that registered entities are saved to.
type RecordState struct {
Name string
Type RecordType
Data string
ID byte
}
// Update updates NameService contract.
func Update(nef []byte, manifest string, data interface{}) {
checkCommittee()
// Calculating keys and serializing requires calling
// std and crypto contracts. This can be helpful on update
// thus we provide `AllowCall` to management.Update.
// management.Update(nef, []byte(manifest))
contract.Call(interop.Hash160(management.Hash), "update",
contract.All, nef, manifest, common.AppendVersion(data))
runtime.Log("nns contract updated")
}
// _deploy initializes defaults (total supply and registration price) on contract deploy.
func _deploy(data interface{}, isUpdate bool) {
if isUpdate {
args := data.([]interface{})
common.CheckVersion(args[len(args)-1].(int))
return
}
ctx := storage.GetContext()
storage.Put(ctx, []byte{prefixTotalSupply}, 0)
storage.Put(ctx, []byte{prefixRegisterPrice}, defaultRegisterPrice)
}
// Symbol returns NeoNameService symbol.
func Symbol() string {
return "NNS"
}
// Decimals returns NeoNameService decimals.
func Decimals() int {
return 0
}
// Version returns the version of the contract.
func Version() int {
return common.Version
}
// TotalSupply returns the overall number of domains minted by NeoNameService contract.
func TotalSupply() int {
ctx := storage.GetReadOnlyContext()
return getTotalSupply(ctx)
}
// OwnerOf returns the owner of the specified domain.
func OwnerOf(tokenID []byte) interop.Hash160 {
ctx := storage.GetReadOnlyContext()
ns := getNameState(ctx, tokenID)
return ns.Owner
}
// Properties returns a domain name and an expiration date of the specified domain.
func Properties(tokenID []byte) map[string]interface{} {
ctx := storage.GetReadOnlyContext()
ns := getNameState(ctx, tokenID)
return map[string]interface{}{
"name": ns.Name,
"expiration": ns.Expiration,
}
}
// BalanceOf returns the overall number of domains owned by the specified owner.
func BalanceOf(owner interop.Hash160) int {
if !isValid(owner) {
panic(`invalid owner`)
}
ctx := storage.GetReadOnlyContext()
balance := storage.Get(ctx, append([]byte{prefixBalance}, owner...))
if balance == nil {
return 0
}
return balance.(int)
}
// Tokens returns iterator over a set of all registered domain names.
func Tokens() iterator.Iterator {
ctx := storage.GetReadOnlyContext()
return storage.Find(ctx, []byte{prefixName}, storage.ValuesOnly|storage.DeserializeValues|storage.PickField1)
}
// TokensOf returns iterator over minted domains owned by the specified owner.
func TokensOf(owner interop.Hash160) iterator.Iterator {
if !isValid(owner) {
panic(`invalid owner`)
}
ctx := storage.GetReadOnlyContext()
return storage.Find(ctx, append([]byte{prefixAccountToken}, owner...), storage.ValuesOnly)
}
// Transfer transfers the domain with the specified name to a new owner.
func Transfer(to interop.Hash160, tokenID []byte, data interface{}) bool {
if !isValid(to) {
panic(`invalid receiver`)
}
var (
tokenKey = getTokenKey(tokenID)
ctx = storage.GetContext()
)
ns := getNameStateWithKey(ctx, tokenKey)
from := ns.Owner
if !runtime.CheckWitness(from) {
return false
}
if !util.Equals(from, to) {
// update token info
ns.Owner = to
ns.Admin = nil
putNameStateWithKey(ctx, tokenKey, ns)
// update `from` balance
updateBalance(ctx, tokenID, from, -1)
// update `to` balance
updateBalance(ctx, tokenID, to, +1)
}
postTransfer(from, to, tokenID, data)
return true
}
// Roots returns iterator over a set of NameService roots.
func Roots() iterator.Iterator {
ctx := storage.GetReadOnlyContext()
return storage.Find(ctx, []byte{prefixRoot}, storage.KeysOnly|storage.RemovePrefix)
}
// SetPrice sets the domain registration price.
func SetPrice(price int64) {
checkCommittee()
if price < 0 || price > maxRegisterPrice {
panic("The price is out of range.")
}
ctx := storage.GetContext()
storage.Put(ctx, []byte{prefixRegisterPrice}, price)
}
// GetPrice returns the domain registration price.
func GetPrice() int {
ctx := storage.GetReadOnlyContext()
return storage.Get(ctx, []byte{prefixRegisterPrice}).(int)
}
// IsAvailable checks whether the provided domain name is available.
func IsAvailable(name string) bool {
fragments := splitAndCheck(name, false)
if fragments == nil {
panic("invalid domain name format")
}
ctx := storage.GetReadOnlyContext()
l := len(fragments)
if storage.Get(ctx, append([]byte{prefixRoot}, []byte(fragments[l-1])...)) == nil {
if l != 1 {
panic("TLD not found")
}
return true
}
return parentExpired(ctx, 0, fragments)
}
// parentExpired returns true if any domain from fragments doesn't exist or is expired.
// first denotes the deepest subdomain to check.
func parentExpired(ctx storage.Context, first int, fragments []string) bool {
now := int64(runtime.GetTime())
last := len(fragments) - 1
name := fragments[last]
for i := last; i >= first; i-- {
if i != last {
name = fragments[i] + "." + name
}
nsBytes := storage.Get(ctx, append([]byte{prefixName}, getTokenKey([]byte(name))...))
if nsBytes == nil {
return true
}
ns := std.Deserialize(nsBytes.([]byte)).(NameState)
if now >= ns.Expiration {
return true
}
}
return false
}
// Register registers a new domain with the specified owner and name if it's available.
func Register(name string, owner interop.Hash160, email string, refresh, retry, expire, ttl int) bool {
fragments := splitAndCheck(name, true)
if fragments == nil {
panic("invalid domain name format")
}
l := len(fragments)
tldKey := append([]byte{prefixRoot}, []byte(fragments[l-1])...)
ctx := storage.GetContext()
tldBytes := storage.Get(ctx, tldKey)
if l == 1 {
checkCommittee()
if tldBytes != nil {
panic("TLD already exists")
}
storage.Put(ctx, tldKey, 0)
} else {
if tldBytes == nil {
panic("TLD not found")
}
if parentExpired(ctx, 1, fragments) {
panic("one of the parent domains is not registered")
}
parentKey := getTokenKey([]byte(name[len(fragments[0])+1:]))
nsBytes := storage.Get(ctx, append([]byte{prefixName}, parentKey...))
ns := std.Deserialize(nsBytes.([]byte)).(NameState)
ns.checkAdmin()
parentRecKey := append([]byte{prefixRecord}, parentKey...)
it := storage.Find(ctx, parentRecKey, storage.ValuesOnly|storage.DeserializeValues)
suffix := []byte(name)
for iterator.Next(it) {
r := iterator.Value(it).(RecordState)
ind := std.MemorySearchLastIndex([]byte(r.Name), suffix, len(r.Name))
if ind > 0 && ind+len(suffix) == len(r.Name) {
panic("parent domain has conflicting records: " + r.Name)
}
}
}
if !isValid(owner) {
panic("invalid owner")
}
common.CheckOwnerWitness(owner)
runtime.BurnGas(GetPrice())
var (
tokenKey = getTokenKey([]byte(name))
oldOwner interop.Hash160
)
nsBytes := storage.Get(ctx, append([]byte{prefixName}, tokenKey...))
if nsBytes != nil {
ns := std.Deserialize(nsBytes.([]byte)).(NameState)
if int64(runtime.GetTime()) < ns.Expiration {
return false
}
oldOwner = ns.Owner
updateBalance(ctx, []byte(name), oldOwner, -1)
} else {
updateTotalSupply(ctx, +1)
}
ns := NameState{
Owner: owner,
Name: name,
Expiration: int64(runtime.GetTime()) + millisecondsInYear,
}
putNameStateWithKey(ctx, tokenKey, ns)
putSoaRecord(ctx, name, email, refresh, retry, expire, ttl)
updateBalance(ctx, []byte(name), owner, +1)
postTransfer(oldOwner, owner, []byte(name), nil)
return true
}
// Renew increases domain expiration date.
func Renew(name string) int64 {
if len(name) > maxDomainNameLength {
panic("invalid domain name format")
}
runtime.BurnGas(GetPrice())
ctx := storage.GetContext()
ns := getNameState(ctx, []byte(name))
ns.Expiration += millisecondsInYear
putNameState(ctx, ns)
return ns.Expiration
}
// UpdateSOA updates soa record.
func UpdateSOA(name, email string, refresh, retry, expire, ttl int) {
if len(name) > maxDomainNameLength {
panic("invalid domain name format")
}
ctx := storage.GetContext()
ns := getNameState(ctx, []byte(name))
ns.checkAdmin()
putSoaRecord(ctx, name, email, refresh, retry, expire, ttl)
}
// SetAdmin updates domain admin.
func SetAdmin(name string, admin interop.Hash160) {
if len(name) > maxDomainNameLength {
panic("invalid domain name format")
}
if admin != nil && !runtime.CheckWitness(admin) {
panic("not witnessed by admin")
}
ctx := storage.GetContext()
ns := getNameState(ctx, []byte(name))
common.CheckOwnerWitness(ns.Owner)
ns.Admin = admin
putNameState(ctx, ns)
}
// SetRecord adds a new record of the specified type to the provided domain.
func SetRecord(name string, typ RecordType, id byte, data string) {
tokenID := []byte(tokenIDFromName(name))
if !checkBaseRecords(typ, data) {
panic("invalid record data")
}
ctx := storage.GetContext()
ns := getNameState(ctx, tokenID)
ns.checkAdmin()
putRecord(ctx, tokenID, name, typ, id, data)
updateSoaSerial(ctx, tokenID)
}
func checkBaseRecords(typ RecordType, data string) bool {
switch typ {
case A:
return checkIPv4(data)
case CNAME:
return splitAndCheck(data, true) != nil
case TXT:
return len(data) <= maxTXTRecordLength
case AAAA:
return checkIPv6(data)
default:
panic("unsupported record type")
}
}
// AddRecord adds a new record of the specified type to the provided domain.
func AddRecord(name string, typ RecordType, data string) {
tokenID := []byte(tokenIDFromName(name))
if !checkBaseRecords(typ, data) {
panic("invalid record data")
}
ctx := storage.GetContext()
ns := getNameState(ctx, tokenID)
ns.checkAdmin()
addRecord(ctx, tokenID, name, typ, data)
updateSoaSerial(ctx, tokenID)
}
// GetRecords returns domain record of the specified type if it exists or an empty
// string if not.
func GetRecords(name string, typ RecordType) []string {
tokenID := []byte(tokenIDFromName(name))
ctx := storage.GetReadOnlyContext()
_ = getNameState(ctx, tokenID) // ensure not expired
return getRecordsByType(ctx, tokenID, name, typ)
}
// DeleteRecords removes domain records with the specified type.
func DeleteRecords(name string, typ RecordType) {
if typ == SOA {
panic("you cannot delete soa record")
}
tokenID := []byte(tokenIDFromName(name))
ctx := storage.GetContext()
ns := getNameState(ctx, tokenID)
ns.checkAdmin()
recordsKey := getRecordsKeyByType(tokenID, name, typ)
records := storage.Find(ctx, recordsKey, storage.KeysOnly)
for iterator.Next(records) {
r := iterator.Value(records).(string)
storage.Delete(ctx, r)
}
updateSoaSerial(ctx, tokenID)
}
// Resolve resolves given name (not more then three redirects are allowed).
func Resolve(name string, typ RecordType) []string {
ctx := storage.GetReadOnlyContext()
return resolve(ctx, nil, name, typ, 2)
}
// GetAllRecords returns an Iterator with RecordState items for the given name.
func GetAllRecords(name string) iterator.Iterator {
tokenID := []byte(tokenIDFromName(name))
ctx := storage.GetReadOnlyContext()
_ = getNameState(ctx, tokenID) // ensure not expired
recordsKey := getRecordsKey(tokenID, name)
return storage.Find(ctx, recordsKey, storage.ValuesOnly|storage.DeserializeValues)
}
// updateBalance updates account's balance and account's tokens.
func updateBalance(ctx storage.Context, tokenId []byte, acc interop.Hash160, diff int) {
balanceKey := append([]byte{prefixBalance}, acc...)
var balance int
if b := storage.Get(ctx, balanceKey); b != nil {
balance = b.(int)
}
balance += diff
if balance == 0 {
storage.Delete(ctx, balanceKey)
} else {
storage.Put(ctx, balanceKey, balance)
}
tokenKey := getTokenKey(tokenId)
accountTokenKey := append(append([]byte{prefixAccountToken}, acc...), tokenKey...)
if diff < 0 {
storage.Delete(ctx, accountTokenKey)
} else {
storage.Put(ctx, accountTokenKey, tokenId)
}
}
// postTransfer sends Transfer notification to the network and calls onNEP11Payment
// method.
func postTransfer(from, to interop.Hash160, tokenID []byte, data interface{}) {
runtime.Notify("Transfer", from, to, 1, tokenID)
if management.GetContract(to) != nil {
contract.Call(to, "onNEP11Payment", contract.All, from, 1, tokenID, data)
}
}
// getTotalSupply returns total supply from storage.
func getTotalSupply(ctx storage.Context) int {
val := storage.Get(ctx, []byte{prefixTotalSupply})
return val.(int)
}
// updateTotalSupply adds the specified diff to the total supply.
func updateTotalSupply(ctx storage.Context, diff int) {
tsKey := []byte{prefixTotalSupply}
ts := getTotalSupply(ctx)
storage.Put(ctx, tsKey, ts+diff)
}
// getTokenKey computes hash160 from the given tokenID.
func getTokenKey(tokenID []byte) []byte {
return crypto.Ripemd160(tokenID)
}
// getNameState returns domain name state by the specified tokenID.
func getNameState(ctx storage.Context, tokenID []byte) NameState {
tokenKey := getTokenKey(tokenID)
ns := getNameStateWithKey(ctx, tokenKey)
fragments := std.StringSplit(string(tokenID), ".")
if parentExpired(ctx, 1, fragments) {
panic("parent domain has expired")
}
return ns
}
// getNameStateWithKey returns domain name state by the specified token key.
func getNameStateWithKey(ctx storage.Context, tokenKey []byte) NameState {
nameKey := append([]byte{prefixName}, tokenKey...)
nsBytes := storage.Get(ctx, nameKey)
if nsBytes == nil {
panic("token not found")
}
ns := std.Deserialize(nsBytes.([]byte)).(NameState)
ns.ensureNotExpired()
return ns
}
// putNameState stores domain name state.
func putNameState(ctx storage.Context, ns NameState) {
tokenKey := getTokenKey([]byte(ns.Name))
putNameStateWithKey(ctx, tokenKey, ns)
}
// putNameStateWithKey stores domain name state with the specified token key.
func putNameStateWithKey(ctx storage.Context, tokenKey []byte, ns NameState) {
nameKey := append([]byte{prefixName}, tokenKey...)
nsBytes := std.Serialize(ns)
storage.Put(ctx, nameKey, nsBytes)
}
// getRecordsByType returns domain record.
func getRecordsByType(ctx storage.Context, tokenId []byte, name string, typ RecordType) []string {
recordsKey := getRecordsKeyByType(tokenId, name, typ)
var result []string
records := storage.Find(ctx, recordsKey, storage.ValuesOnly|storage.DeserializeValues)
for iterator.Next(records) {
r := iterator.Value(records).(RecordState)
if r.Type == typ {
result = append(result, r.Data)
}
}
return result
}
// putRecord stores domain record.
func putRecord(ctx storage.Context, tokenId []byte, name string, typ RecordType, id byte, data string) {
recordKey := getIdRecordKey(tokenId, name, typ, id)
recBytes := storage.Get(ctx, recordKey)
if recBytes == nil {
panic("invalid record id")
}
storeRecord(ctx, recordKey, name, typ, id, data)
}
// addRecord stores domain record.
func addRecord(ctx storage.Context, tokenId []byte, name string, typ RecordType, data string) {
recordsKey := getRecordsKeyByType(tokenId, name, typ)
var id byte
records := storage.Find(ctx, recordsKey, storage.ValuesOnly|storage.DeserializeValues)
for iterator.Next(records) {
id++
r := iterator.Value(records).(RecordState)
if r.Name == name && r.Type == typ && r.Data == data {
panic("record already exists")
}
}
if typ == CNAME && id != 0 {
panic("you shouldn't have more than one CNAME record")
}
recordKey := append(recordsKey, id) // the same as getIdRecordKey
storeRecord(ctx, recordKey, name, typ, id, data)
}
// storeRecord puts record to storage.
func storeRecord(ctx storage.Context, recordKey []byte, name string, typ RecordType, id byte, data string) {
rs := RecordState{
Name: name,
Type: typ,
Data: data,
ID: id,
}
recBytes := std.Serialize(rs)
storage.Put(ctx, recordKey, recBytes)
}
// putSoaRecord stores soa domain record.
func putSoaRecord(ctx storage.Context, name, email string, refresh, retry, expire, ttl int) {
var id byte
tokenId := []byte(tokenIDFromName(name))
recordKey := getIdRecordKey(tokenId, name, SOA, id)
rs := RecordState{
Name: name,
Type: SOA,
ID: id,
Data: name + " " + email + " " +
std.Itoa(runtime.GetTime(), 10) + " " +
std.Itoa(refresh, 10) + " " +
std.Itoa(retry, 10) + " " +
std.Itoa(expire, 10) + " " +
std.Itoa(ttl, 10),
}
recBytes := std.Serialize(rs)
storage.Put(ctx, recordKey, recBytes)
}
// updateSoaSerial stores soa domain record.
func updateSoaSerial(ctx storage.Context, tokenId []byte) {
var id byte
recordKey := getIdRecordKey(tokenId, string(tokenId), SOA, id)
recBytes := storage.Get(ctx, recordKey)
if recBytes == nil {
panic("not found soa record")
}
rec := std.Deserialize(recBytes.([]byte)).(RecordState)
split := std.StringSplitNonEmpty(rec.Data, " ")
if len(split) != 7 {
panic("invalid soa record")
}
split[2] = std.Itoa(runtime.GetTime(), 10) // update serial
rec.Data = split[0] + " " + split[1] + " " +
split[2] + " " + split[3] + " " +
split[4] + " " + split[5] + " " +
split[6]
recBytes = std.Serialize(rec)
storage.Put(ctx, recordKey, recBytes)
}
// getRecordsKey returns the prefix used to store domain records of different types.
func getRecordsKey(tokenId []byte, name string) []byte {
recordKey := append([]byte{prefixRecord}, getTokenKey(tokenId)...)
return append(recordKey, getTokenKey([]byte(name))...)
}
// getRecordsKeyByType returns the key used to store domain records.
func getRecordsKeyByType(tokenId []byte, name string, typ RecordType) []byte {
recordKey := getRecordsKey(tokenId, name)
return append(recordKey, byte(typ))
}
// getIdRecordKey returns the key used to store domain records.
func getIdRecordKey(tokenId []byte, name string, typ RecordType, id byte) []byte {
recordKey := getRecordsKey(tokenId, name)
return append(recordKey, byte(typ), id)
}
// isValid returns true if the provided address is a valid Uint160.
func isValid(address interop.Hash160) bool {
return address != nil && len(address) == interop.Hash160Len
}
// checkCommittee panics if the script container is not signed by the committee.
func checkCommittee() {
committee := neo.GetCommittee()
if committee == nil {
panic("failed to get committee")
}
l := len(committee)
committeeMultisig := contract.CreateMultisigAccount(l-(l-1)/2, committee)
if committeeMultisig == nil || !runtime.CheckWitness(committeeMultisig) {
panic("not witnessed by committee")
}
}
// checkFragment validates root or a part of domain name.
// 1. Root domain must start with a letter.
// 2. All other fragments must start and end with a letter or a digit.
func checkFragment(v string, isRoot bool) bool {
maxLength := maxDomainNameFragmentLength
if isRoot {
maxLength = maxRootLength
}
if len(v) == 0 || len(v) > maxLength {
return false
}
c := v[0]
if isRoot {
if !(c >= 'a' && c <= 'z') {
return false
}
} else {
if !isAlNum(c) {
return false
}
}
for i := 1; i < len(v)-1; i++ {
if v[i] != '-' && !isAlNum(v[i]) {
return false
}
}
return isAlNum(v[len(v)-1])
}
// isAlNum checks whether provided char is a lowercase letter or a number.
func isAlNum(c uint8) bool {
return c >= 'a' && c <= 'z' || c >= '0' && c <= '9'
}
// splitAndCheck splits domain name into parts and validates it.
func splitAndCheck(name string, allowMultipleFragments bool) []string {
l := len(name)
if l < minDomainNameLength || maxDomainNameLength < l {
return nil
}
fragments := std.StringSplit(name, ".")
l = len(fragments)
if l > 2 && !allowMultipleFragments {
return nil
}
for i := 0; i < l; i++ {
if !checkFragment(fragments[i], i == l-1) {
return nil
}
}
return fragments
}
// checkIPv4 checks record on IPv4 compliance.
func checkIPv4(data string) bool {
l := len(data)
if l < 7 || 15 < l {
return false
}
fragments := std.StringSplit(data, ".")
if len(fragments) != 4 {
return false
}
numbers := make([]int, 4)
for i, f := range fragments {
if len(f) == 0 {
return false
}
number := std.Atoi10(f)
if number < 0 || 255 < number {
panic("not a byte")
}
if number > 0 && f[0] == '0' {
return false
}
if number == 0 && len(f) > 1 {
return false
}
numbers[i] = number
}
n0 := numbers[0]
n1 := numbers[1]
n3 := numbers[3]
if n0 == 0 ||
n0 == 10 ||
n0 == 127 ||
n0 >= 224 ||
(n0 == 169 && n1 == 254) ||
(n0 == 172 && 16 <= n1 && n1 <= 31) ||
(n0 == 192 && n1 == 168) ||
n3 == 0 ||
n3 == 255 {
return false
}
return true
}
// checkIPv6 checks record on IPv6 compliance.
func checkIPv6(data string) bool {
l := len(data)
if l < 2 || 39 < l {
return false
}
fragments := std.StringSplit(data, ":")
l = len(fragments)
if l < 3 || 8 < l {
return false
}
var hasEmpty bool
nums := make([]int, 8)
for i, f := range fragments {
if len(f) == 0 {
if i == 0 {
if len(fragments[1]) != 0 {
return false
}
nums[i] = 0
} else if i == l-1 {
if len(fragments[i-1]) != 0 {
return false
}
nums[7] = 0
} else if hasEmpty {
return false
} else {
hasEmpty = true
endIndex := 9 - l + i
for j := i; j < endIndex; j++ {
nums[j] = 0
}
}
} else {
if len(f) > 4 {
return false
}
n := std.Atoi(f, 16)
if 65535 < n {
panic("fragment overflows uint16: " + f)
}
idx := i
if hasEmpty {
idx = i + 8 - l
}
nums[idx] = n
}
}
if l < 8 && !hasEmpty {
return false
}
f0 := nums[0]
if f0 < 0x2000 || f0 == 0x2002 || f0 == 0x3ffe || f0 > 0x3fff { // IPv6 Global Unicast https://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.xhtml
return false
}
if f0 == 0x2001 {
f1 := nums[1]
if f1 < 0x200 || f1 == 0xdb8 {
return false
}
}
return true
}
// tokenIDFromName returns token ID (domain.root) from the provided name.
func tokenIDFromName(name string) string {
fragments := splitAndCheck(name, true)
if fragments == nil {
panic("invalid domain name format")
}
ctx := storage.GetReadOnlyContext()
sum := 0
l := len(fragments) - 1
for i := 0; i < l; i++ {
tokenKey := getTokenKey([]byte(name[sum:]))
nameKey := append([]byte{prefixName}, tokenKey...)
nsBytes := storage.Get(ctx, nameKey)
if nsBytes != nil {
ns := std.Deserialize(nsBytes.([]byte)).(NameState)
if int64(runtime.GetTime()) < ns.Expiration {
return name[sum:]
}
}
sum += len(fragments[i]) + 1
}
return name
}
// resolve resolves the provided name using record with the specified type and given
// maximum redirections constraint.
func resolve(ctx storage.Context, res []string, name string, typ RecordType, redirect int) []string {
if redirect < 0 {
panic("invalid redirect")
}
if len(name) == 0 {
panic("invalid name")
}
if name[len(name)-1] == '.' {
name = name[:len(name)-1]
}
records := getAllRecords(ctx, name)
cname := ""
for iterator.Next(records) {
r := iterator.Value(records).(RecordState)
if r.Type == typ {
res = append(res, r.Data)
}
if r.Type == CNAME {
cname = r.Data
}
}
if cname == "" || typ == CNAME {
return res
}
res = append(res, cname)
return resolve(ctx, res, cname, typ, redirect-1)
}
// getAllRecords returns iterator over the set of records corresponded with the
// specified name.
func getAllRecords(ctx storage.Context, name string) iterator.Iterator {
tokenID := []byte(tokenIDFromName(name))
_ = getNameState(ctx, tokenID)
recordsKey := getRecordsKey(tokenID, name)
return storage.Find(ctx, recordsKey, storage.ValuesOnly|storage.DeserializeValues)
}