helpers.go 18 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796
  1. //TODO: Consider restructuring this file/folder "github.com/gorilla/handlers"
  2. //It may make more sense to split into different files and not call it "helpers"
  3. package functions
  4. import (
  5. "encoding/base64"
  6. "encoding/json"
  7. "errors"
  8. "fmt"
  9. "log"
  10. "math/rand"
  11. "net"
  12. "strings"
  13. "time"
  14. "github.com/gravitl/netmaker/database"
  15. "github.com/gravitl/netmaker/models"
  16. "github.com/gravitl/netmaker/servercfg"
  17. )
  18. func CheckEndpoint(endpoint string) bool {
  19. endpointarr := strings.Split(endpoint, ":")
  20. return len(endpointarr) == 2
  21. }
  22. func PrintUserLog(username string, message string, loglevel int) {
  23. log.SetFlags(log.Flags() &^ (log.Llongfile | log.Lshortfile))
  24. if int32(loglevel) <= servercfg.GetVerbose() && servercfg.GetVerbose() != 0 {
  25. log.Println(username, message)
  26. }
  27. }
  28. func ParseNetwork(value string) (models.Network, error) {
  29. var network models.Network
  30. err := json.Unmarshal([]byte(value), &network)
  31. return network, err
  32. }
  33. func ParseNode(value string) (models.Node, error) {
  34. var node models.Node
  35. err := json.Unmarshal([]byte(value), &node)
  36. return node, err
  37. }
  38. func ParseExtClient(value string) (models.ExtClient, error) {
  39. var extClient models.ExtClient
  40. err := json.Unmarshal([]byte(value), &extClient)
  41. return extClient, err
  42. }
  43. func ParseIntClient(value string) (models.IntClient, error) {
  44. var intClient models.IntClient
  45. err := json.Unmarshal([]byte(value), &intClient)
  46. return intClient, err
  47. }
  48. //Takes in an arbitrary field and value for field and checks to see if any other
  49. //node has that value for the same field within the network
  50. func GetUser(username string) (models.User, error) {
  51. var user models.User
  52. record, err := database.FetchRecord(database.USERS_TABLE_NAME, username)
  53. if err != nil {
  54. return user, err
  55. }
  56. if err = json.Unmarshal([]byte(record), &user); err != nil {
  57. return models.User{}, err
  58. }
  59. return user, err
  60. }
  61. func SliceContains(slice []string, item string) bool {
  62. set := make(map[string]struct{}, len(slice))
  63. for _, s := range slice {
  64. set[s] = struct{}{}
  65. }
  66. _, ok := set[item]
  67. return ok
  68. }
  69. func CreateServerToken(netID string) (string, error) {
  70. var network models.Network
  71. var accesskey models.AccessKey
  72. network, err := GetParentNetwork(netID)
  73. if err != nil {
  74. return "", err
  75. }
  76. var accessToken models.AccessToken
  77. servervals := models.ServerConfig{
  78. APIConnString: "127.0.0.1:" + servercfg.GetAPIPort(),
  79. GRPCConnString: "127.0.0.1:" + servercfg.GetGRPCPort(),
  80. GRPCSSL: "off",
  81. }
  82. accessToken.ServerConfig = servervals
  83. accessToken.ClientConfig.Network = netID
  84. accessToken.ClientConfig.Key = GenKey()
  85. accesskey.Name = GenKeyName()
  86. accesskey.Value = accessToken.ClientConfig.Key
  87. accesskey.Uses = 1
  88. tokenjson, err := json.Marshal(accessToken)
  89. if err != nil {
  90. return accesskey.AccessString, err
  91. }
  92. accesskey.AccessString = base64.StdEncoding.EncodeToString([]byte(tokenjson))
  93. network.AccessKeys = append(network.AccessKeys, accesskey)
  94. if data, err := json.Marshal(network); err != nil {
  95. return "", err
  96. } else {
  97. database.Insert(netID, string(data), database.NETWORKS_TABLE_NAME)
  98. }
  99. return accesskey.AccessString, nil
  100. }
  101. func GetPeersList(networkName string) ([]models.PeersResponse, error) {
  102. var peers []models.PeersResponse
  103. collection, err := database.FetchRecords(database.NODES_TABLE_NAME)
  104. if err != nil {
  105. return peers, err
  106. }
  107. for _, value := range collection {
  108. var peer models.PeersResponse
  109. err := json.Unmarshal([]byte(value), &peer)
  110. if err != nil {
  111. continue // try the rest
  112. }
  113. peers = append(peers, peer)
  114. }
  115. return peers, err
  116. }
  117. func GetIntPeersList() ([]models.PeersResponse, error) {
  118. var peers []models.PeersResponse
  119. records, err := database.FetchRecords(database.INT_CLIENTS_TABLE_NAME)
  120. if err != nil {
  121. return peers, err
  122. }
  123. // parse the peers
  124. for _, value := range records {
  125. var peer models.PeersResponse
  126. err := json.Unmarshal([]byte(value), &peer)
  127. if err != nil {
  128. log.Fatal(err)
  129. }
  130. // add the node to our node array
  131. //maybe better to just return this? But then that's just GetNodes...
  132. peers = append(peers, peer)
  133. }
  134. return peers, err
  135. }
  136. func GetServerIntClient() (*models.IntClient, error) {
  137. intClients, err := database.FetchRecords(database.INT_CLIENTS_TABLE_NAME)
  138. for _, value := range intClients {
  139. var intClient models.IntClient
  140. err = json.Unmarshal([]byte(value), &intClient)
  141. if err != nil {
  142. return nil, err
  143. }
  144. if intClient.IsServer == "yes" && intClient.Network == "comms" {
  145. return &intClient, nil
  146. }
  147. }
  148. return nil, err
  149. }
  150. func NetworkExists(name string) (bool, error) {
  151. var network string
  152. var err error
  153. if network, err = database.FetchRecord(database.NETWORKS_TABLE_NAME, name); err != nil {
  154. return false, err
  155. }
  156. return len(network) > 0, nil
  157. }
  158. func GetRecordKey(id string, network string) (string, error) {
  159. if id == "" || network == "" {
  160. return "", errors.New("unable to get record key")
  161. }
  162. return id + "###" + network, nil
  163. }
  164. func UpdateNetworkNodeAddresses(networkName string) error {
  165. collections, err := database.FetchRecords(database.NODES_TABLE_NAME)
  166. if err != nil {
  167. return err
  168. }
  169. for _, value := range collections {
  170. var node models.Node
  171. err := json.Unmarshal([]byte(value), &node)
  172. if err != nil {
  173. fmt.Println("error in node address assignment!")
  174. return err
  175. }
  176. if node.Network == networkName {
  177. ipaddr, iperr := UniqueAddress(networkName)
  178. if iperr != nil {
  179. fmt.Println("error in node address assignment!")
  180. return iperr
  181. }
  182. node.Address = ipaddr
  183. data, err := json.Marshal(&node)
  184. if err != nil {
  185. return err
  186. }
  187. node.SetID()
  188. database.Insert(node.ID, string(data), database.NODES_TABLE_NAME)
  189. }
  190. }
  191. return nil
  192. }
  193. func NetworkNodesUpdateAction(networkName string, action string) error {
  194. collections, err := database.FetchRecords(database.NODES_TABLE_NAME)
  195. if err != nil {
  196. if database.IsEmptyRecord(err) {
  197. return nil
  198. }
  199. return err
  200. }
  201. for _, value := range collections {
  202. var node models.Node
  203. err := json.Unmarshal([]byte(value), &node)
  204. if err != nil {
  205. fmt.Println("error in node address assignment!")
  206. return err
  207. }
  208. if action == models.NODE_UPDATE_KEY && node.StaticPubKey == "yes" {
  209. continue
  210. }
  211. if node.Network == networkName {
  212. node.Action = action
  213. data, err := json.Marshal(&node)
  214. if err != nil {
  215. return err
  216. }
  217. node.SetID()
  218. database.Insert(node.ID, string(data), database.NODES_TABLE_NAME)
  219. }
  220. }
  221. return nil
  222. }
  223. func NetworkNodesUpdatePullChanges(networkName string) error {
  224. collections, err := database.FetchRecords(database.NODES_TABLE_NAME)
  225. if err != nil {
  226. if database.IsEmptyRecord(err) {
  227. return nil
  228. }
  229. return err
  230. }
  231. for _, value := range collections {
  232. var node models.Node
  233. err := json.Unmarshal([]byte(value), &node)
  234. if err != nil {
  235. fmt.Println("error in node address assignment!")
  236. return err
  237. }
  238. if node.Network == networkName {
  239. node.PullChanges = "yes"
  240. data, err := json.Marshal(&node)
  241. if err != nil {
  242. return err
  243. }
  244. node.SetID()
  245. database.Insert(node.ID, string(data), database.NODES_TABLE_NAME)
  246. }
  247. }
  248. return nil
  249. }
  250. func UpdateNetworkLocalAddresses(networkName string) error {
  251. collection, err := database.FetchRecords(database.NODES_TABLE_NAME)
  252. if err != nil {
  253. return err
  254. }
  255. for _, value := range collection {
  256. var node models.Node
  257. err := json.Unmarshal([]byte(value), &node)
  258. if err != nil {
  259. fmt.Println("error in node address assignment!")
  260. return err
  261. }
  262. if node.Network == networkName {
  263. ipaddr, iperr := UniqueAddress(networkName)
  264. if iperr != nil {
  265. fmt.Println("error in node address assignment!")
  266. return iperr
  267. }
  268. node.Address = ipaddr
  269. newNodeData, err := json.Marshal(&node)
  270. if err != nil {
  271. fmt.Println("error in node address assignment!")
  272. return err
  273. }
  274. node.SetID()
  275. database.Insert(node.ID, string(newNodeData), database.NODES_TABLE_NAME)
  276. }
  277. }
  278. return nil
  279. }
  280. func IsNetworkDisplayNameUnique(name string) (bool, error) {
  281. isunique := true
  282. dbs, err := models.GetNetworks()
  283. if err != nil {
  284. return database.IsEmptyRecord(err), err
  285. }
  286. for i := 0; i < len(dbs); i++ {
  287. if name == dbs[i].DisplayName {
  288. isunique = false
  289. }
  290. }
  291. return isunique, nil
  292. }
  293. func IsMacAddressUnique(macaddress string, networkName string) (bool, error) {
  294. _, err := database.FetchRecord(database.NODES_TABLE_NAME, macaddress+"###"+networkName)
  295. if err != nil {
  296. return database.IsEmptyRecord(err), err
  297. }
  298. return true, nil
  299. }
  300. func GetNetworkNodeCount(networkName string) (int, error) {
  301. collection, err := database.FetchRecords(database.NODES_TABLE_NAME)
  302. count := 0
  303. if err != nil && !database.IsEmptyRecord(err) {
  304. return count, err
  305. }
  306. for _, value := range collection {
  307. var node models.Node
  308. if err = json.Unmarshal([]byte(value), &node); err != nil {
  309. return count, err
  310. } else {
  311. if node.Network == networkName {
  312. count++
  313. }
  314. }
  315. }
  316. return count, nil
  317. }
  318. //Checks to see if access key is valid
  319. //Does so by checking against all keys and seeing if any have the same value
  320. //may want to hash values before comparing...consider this
  321. //TODO: No error handling!!!!
  322. func IsKeyValid(networkname string, keyvalue string) bool {
  323. network, _ := GetParentNetwork(networkname)
  324. var key models.AccessKey
  325. foundkey := false
  326. isvalid := false
  327. for i := len(network.AccessKeys) - 1; i >= 0; i-- {
  328. currentkey := network.AccessKeys[i]
  329. if currentkey.Value == keyvalue {
  330. key = currentkey
  331. foundkey = true
  332. }
  333. }
  334. if foundkey {
  335. if key.Uses > 0 {
  336. isvalid = true
  337. }
  338. }
  339. return isvalid
  340. }
  341. func IsKeyValidGlobal(keyvalue string) bool {
  342. networks, _ := models.GetNetworks()
  343. var key models.AccessKey
  344. foundkey := false
  345. isvalid := false
  346. for _, network := range networks {
  347. for i := len(network.AccessKeys) - 1; i >= 0; i-- {
  348. currentkey := network.AccessKeys[i]
  349. if currentkey.Value == keyvalue {
  350. key = currentkey
  351. foundkey = true
  352. break
  353. }
  354. }
  355. if foundkey {
  356. break
  357. }
  358. }
  359. if foundkey {
  360. if key.Uses > 0 {
  361. isvalid = true
  362. }
  363. }
  364. return isvalid
  365. }
  366. //TODO: Contains a fatal error return. Need to change
  367. //This just gets a network object from a network name
  368. //Should probably just be GetNetwork. kind of a dumb name.
  369. //Used in contexts where it's not the Parent network.
  370. func GetParentNetwork(networkname string) (models.Network, error) {
  371. var network models.Network
  372. networkData, err := database.FetchRecord(database.NETWORKS_TABLE_NAME, networkname)
  373. if err != nil {
  374. return network, err
  375. }
  376. if err = json.Unmarshal([]byte(networkData), &network); err != nil {
  377. return models.Network{}, err
  378. }
  379. return network, nil
  380. }
  381. func IsIpNet(host string) bool {
  382. return net.ParseIP(host) != nil
  383. }
  384. //Similar to above but checks if Cidr range is valid
  385. //At least this guy's got some print statements
  386. //still not good error handling
  387. func IsIpCIDR(host string) bool {
  388. ip, ipnet, err := net.ParseCIDR(host)
  389. if err != nil {
  390. fmt.Println(err)
  391. fmt.Println("Address Range is not valid!")
  392. return false
  393. }
  394. return ip != nil && ipnet != nil
  395. }
  396. //This is used to validate public keys (make sure they're base64 encoded like all public keys should be).
  397. func IsBase64(s string) bool {
  398. _, err := base64.StdEncoding.DecodeString(s)
  399. return err == nil
  400. }
  401. //This checks to make sure a network name is valid.
  402. //Switch to REGEX?
  403. func NameInNetworkCharSet(name string) bool {
  404. charset := "abcdefghijklmnopqrstuvwxyz1234567890-_."
  405. for _, char := range name {
  406. if !strings.Contains(charset, strings.ToLower(string(char))) {
  407. return false
  408. }
  409. }
  410. return true
  411. }
  412. func NameInDNSCharSet(name string) bool {
  413. charset := "abcdefghijklmnopqrstuvwxyz1234567890-."
  414. for _, char := range name {
  415. if !strings.Contains(charset, strings.ToLower(string(char))) {
  416. return false
  417. }
  418. }
  419. return true
  420. }
  421. func NameInNodeCharSet(name string) bool {
  422. charset := "abcdefghijklmnopqrstuvwxyz1234567890-"
  423. for _, char := range name {
  424. if !strings.Contains(charset, strings.ToLower(string(char))) {
  425. return false
  426. }
  427. }
  428. return true
  429. }
  430. //This returns a node based on its mac address.
  431. //The mac address acts as the Unique ID for nodes.
  432. //Is this a dumb thing to do? I thought it was cool but maybe it's dumb.
  433. //It doesn't really provide a tangible benefit over a random ID
  434. func GetNodeByMacAddress(network string, macaddress string) (models.Node, error) {
  435. var node models.Node
  436. key, err := GetRecordKey(macaddress, network)
  437. if err != nil {
  438. return node, err
  439. }
  440. record, err := database.FetchRecord(database.NODES_TABLE_NAME, key)
  441. if err != nil {
  442. return models.Node{}, err
  443. }
  444. if err = json.Unmarshal([]byte(record), &node); err != nil {
  445. return models.Node{}, err
  446. }
  447. return node, nil
  448. }
  449. func DeleteAllIntClients() error {
  450. err := database.DeleteAllRecords(database.INT_CLIENTS_TABLE_NAME)
  451. if err != nil {
  452. return err
  453. }
  454. return nil
  455. }
  456. func GetAllIntClients() ([]models.IntClient, error) {
  457. var clients []models.IntClient
  458. collection, err := database.FetchRecords(database.INT_CLIENTS_TABLE_NAME)
  459. if err != nil {
  460. return clients, err
  461. }
  462. for _, value := range collection {
  463. var client models.IntClient
  464. err := json.Unmarshal([]byte(value), &client)
  465. if err != nil {
  466. return []models.IntClient{}, err
  467. }
  468. // add node to our array
  469. clients = append(clients, client)
  470. }
  471. return clients, nil
  472. }
  473. func GetAllExtClients() ([]models.ExtClient, error) {
  474. var extclients []models.ExtClient
  475. collection, err := database.FetchRecords(database.EXT_CLIENT_TABLE_NAME)
  476. if err != nil {
  477. return extclients, err
  478. }
  479. for _, value := range collection {
  480. var extclient models.ExtClient
  481. err := json.Unmarshal([]byte(value), &extclient)
  482. if err != nil {
  483. return []models.ExtClient{}, err
  484. }
  485. // add node to our array
  486. extclients = append(extclients, extclient)
  487. }
  488. return extclients, nil
  489. }
  490. //This returns a unique address for a node to use
  491. //it iterates through the list of IP's in the subnet
  492. //and checks against all nodes to see if it's taken, until it finds one.
  493. //TODO: We do not handle a case where we run out of addresses.
  494. //We will need to handle that eventually
  495. func UniqueAddress(networkName string) (string, error) {
  496. var network models.Network
  497. network, err := GetParentNetwork(networkName)
  498. if err != nil {
  499. fmt.Println("UniqueAddress encountered an error")
  500. return "666", err
  501. }
  502. offset := true
  503. ip, ipnet, err := net.ParseCIDR(network.AddressRange)
  504. if err != nil {
  505. fmt.Println("UniqueAddress encountered an error")
  506. return "666", err
  507. }
  508. for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); Inc(ip) {
  509. if offset {
  510. offset = false
  511. continue
  512. }
  513. if networkName == "comms" {
  514. if IsIPUnique(networkName, ip.String(), database.INT_CLIENTS_TABLE_NAME, false) {
  515. return ip.String(), err
  516. }
  517. } else {
  518. if IsIPUnique(networkName, ip.String(), database.NODES_TABLE_NAME, false) && IsIPUnique(networkName, ip.String(), database.EXT_CLIENT_TABLE_NAME, false) {
  519. return ip.String(), err
  520. }
  521. }
  522. }
  523. //TODO
  524. err1 := errors.New("ERROR: No unique addresses available. Check network subnet.")
  525. return "W1R3: NO UNIQUE ADDRESSES AVAILABLE", err1
  526. }
  527. func UniqueAddress6(networkName string) (string, error) {
  528. var network models.Network
  529. network, err := GetParentNetwork(networkName)
  530. if err != nil {
  531. fmt.Println("Network Not Found")
  532. return "", err
  533. }
  534. if network.IsDualStack == "no" {
  535. if networkName != "comms" {
  536. return "", nil
  537. }
  538. }
  539. offset := true
  540. ip, ipnet, err := net.ParseCIDR(network.AddressRange6)
  541. if err != nil {
  542. fmt.Println("UniqueAddress6 encountered an error")
  543. return "666", err
  544. }
  545. for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); Inc(ip) {
  546. if offset {
  547. offset = false
  548. continue
  549. }
  550. if networkName == "comms" {
  551. if IsIPUnique(networkName, ip.String(), database.INT_CLIENTS_TABLE_NAME, true) {
  552. return ip.String(), err
  553. }
  554. } else {
  555. if IsIPUnique(networkName, ip.String(), database.NODES_TABLE_NAME, true) {
  556. return ip.String(), err
  557. }
  558. }
  559. }
  560. //TODO
  561. err1 := errors.New("ERROR: No unique addresses available. Check network subnet.")
  562. return "W1R3: NO UNIQUE ADDRESSES AVAILABLE", err1
  563. }
  564. //generate an access key value
  565. func GenKey() string {
  566. var seededRand *rand.Rand = rand.New(
  567. rand.NewSource(time.Now().UnixNano()))
  568. length := 16
  569. charset := "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
  570. b := make([]byte, length)
  571. for i := range b {
  572. b[i] = charset[seededRand.Intn(len(charset))]
  573. }
  574. return string(b)
  575. }
  576. //generate a key value
  577. //we should probably just have 1 random string generator
  578. //that can be used across all functions
  579. //have a "base string" a "length" and a "charset"
  580. func GenKeyName() string {
  581. var seededRand *rand.Rand = rand.New(
  582. rand.NewSource(time.Now().UnixNano()))
  583. length := 5
  584. charset := "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
  585. b := make([]byte, length)
  586. for i := range b {
  587. b[i] = charset[seededRand.Intn(len(charset))]
  588. }
  589. return "key" + string(b)
  590. }
  591. func IsIPUnique(network string, ip string, tableName string, isIpv6 bool) bool {
  592. isunique := true
  593. collection, err := database.FetchRecords(tableName)
  594. if err != nil {
  595. return isunique
  596. }
  597. for _, value := range collection { // filter
  598. var node models.Node
  599. if err = json.Unmarshal([]byte(value), &node); err != nil {
  600. continue
  601. }
  602. if isIpv6 {
  603. if node.Address6 == ip && node.Network == network {
  604. return false
  605. }
  606. } else {
  607. if node.Address == ip && node.Network == network {
  608. return false
  609. }
  610. }
  611. }
  612. return isunique
  613. }
  614. //called once key has been used by createNode
  615. //reduces value by one and deletes if necessary
  616. func DecrimentKey(networkName string, keyvalue string) {
  617. var network models.Network
  618. network, err := GetParentNetwork(networkName)
  619. if err != nil {
  620. return
  621. }
  622. for i := len(network.AccessKeys) - 1; i >= 0; i-- {
  623. currentkey := network.AccessKeys[i]
  624. if currentkey.Value == keyvalue {
  625. network.AccessKeys[i].Uses--
  626. if network.AccessKeys[i].Uses < 1 {
  627. network.AccessKeys = append(network.AccessKeys[:i],
  628. network.AccessKeys[i+1:]...)
  629. break
  630. }
  631. }
  632. }
  633. if newNetworkData, err := json.Marshal(&network); err != nil {
  634. PrintUserLog(models.NODE_SERVER_NAME, "failed to decrement key", 2)
  635. return
  636. } else {
  637. database.Insert(network.NetID, string(newNetworkData), database.NETWORKS_TABLE_NAME)
  638. }
  639. }
  640. //takes the logic from controllers.deleteKey
  641. func DeleteKey(network models.Network, i int) {
  642. network.AccessKeys = append(network.AccessKeys[:i],
  643. network.AccessKeys[i+1:]...)
  644. if networkData, err := json.Marshal(&network); err != nil {
  645. return
  646. } else {
  647. database.Insert(network.NetID, string(networkData), database.NETWORKS_TABLE_NAME)
  648. }
  649. }
  650. //increments an IP over the previous
  651. func Inc(ip net.IP) {
  652. for j := len(ip) - 1; j >= 0; j-- {
  653. ip[j]++
  654. if ip[j] > 0 {
  655. break
  656. }
  657. }
  658. }