Пример #1
0
// StoreServerEntry adds the server entry to the data store.
// A newly stored (or re-stored) server entry is assigned the next-to-top
// rank for iteration order (the previous top ranked entry is promoted). The
// purpose of inserting at next-to-top is to keep the last selected server
// as the top ranked server.
// When replaceIfExists is true, an existing server entry record is
// overwritten; otherwise, the existing record is unchanged.
// If the server entry data is malformed, an alert notice is issued and
// the entry is skipped; no error is returned.
func StoreServerEntry(serverEntry *protocol.ServerEntry, replaceIfExists bool) error {
	checkInitDataStore()

	// Server entries should already be validated before this point,
	// so instead of skipping we fail with an error.
	err := protocol.ValidateServerEntry(serverEntry)
	if err != nil {
		return common.ContextError(errors.New("invalid server entry"))
	}

	// BoltDB implementation note:
	// For simplicity, we don't maintain indexes on server entry
	// region or supported protocols. Instead, we perform full-bucket
	// scans with a filter. With a small enough database (thousands or
	// even tens of thousand of server entries) and common enough
	// values (e.g., many servers support all protocols), performance
	// is expected to be acceptable.

	err = singleton.db.Update(func(tx *bolt.Tx) error {

		serverEntries := tx.Bucket([]byte(serverEntriesBucket))

		// Check not only that the entry exists, but is valid. This
		// will replace in the rare case where the data is corrupt.
		existingServerEntryValid := false
		existingData := serverEntries.Get([]byte(serverEntry.IpAddress))
		if existingData != nil {
			existingServerEntry := new(protocol.ServerEntry)
			if json.Unmarshal(existingData, existingServerEntry) == nil {
				existingServerEntryValid = true
			}
		}

		if existingServerEntryValid && !replaceIfExists {
			// Disabling this notice, for now, as it generates too much noise
			// in diagnostics with clients that always submit embedded servers
			// to the core on each run.
			// NoticeInfo("ignored update for server %s", serverEntry.IpAddress)
			return nil
		}

		data, err := json.Marshal(serverEntry)
		if err != nil {
			return common.ContextError(err)
		}
		err = serverEntries.Put([]byte(serverEntry.IpAddress), data)
		if err != nil {
			return common.ContextError(err)
		}

		err = insertRankedServerEntry(tx, serverEntry.IpAddress, 1)
		if err != nil {
			return common.ContextError(err)
		}

		NoticeInfo("updated server %s", serverEntry.IpAddress)

		return nil
	})
	if err != nil {
		return common.ContextError(err)
	}

	return nil
}
Пример #2
0
// doHandshakeRequest performs the "handshake" API request. The handshake
// returns upgrade info, newly discovered server entries -- which are
// stored -- and sponsor info (home pages, stat regexes).
func (serverContext *ServerContext) doHandshakeRequest() error {

	params := serverContext.getBaseParams()

	// *TODO*: this is obsolete?
	/*
		serverEntryIpAddresses, err := GetServerEntryIpAddresses()
		if err != nil {
			return common.ContextError(err)
		}

		// Submit a list of known servers -- this will be used for
		// discovery statistics.
		for _, ipAddress := range serverEntryIpAddresses {
			params = append(params, requestParam{"known_server", ipAddress})
		}
	*/

	var response []byte
	if serverContext.psiphonHttpsClient == nil {

		request, err := makeSSHAPIRequestPayload(params)
		if err != nil {
			return common.ContextError(err)
		}

		response, err = serverContext.tunnel.SendAPIRequest(
			protocol.PSIPHON_API_HANDSHAKE_REQUEST_NAME, request)
		if err != nil {
			return common.ContextError(err)
		}

	} else {

		// Legacy web service API request

		responseBody, err := serverContext.doGetRequest(
			makeRequestUrl(serverContext.tunnel, "", "handshake", params))
		if err != nil {
			return common.ContextError(err)
		}
		// Skip legacy format lines and just parse the JSON config line
		configLinePrefix := []byte("Config: ")
		for _, line := range bytes.Split(responseBody, []byte("\n")) {
			if bytes.HasPrefix(line, configLinePrefix) {
				response = line[len(configLinePrefix):]
				break
			}
		}
		if len(response) == 0 {
			return common.ContextError(errors.New("no config line found"))
		}
	}

	// Legacy fields:
	// - 'preemptive_reconnect_lifetime_milliseconds' is unused and ignored
	// - 'ssh_session_id' is ignored; client session ID is used instead

	var handshakeResponse protocol.HandshakeResponse
	err := json.Unmarshal(response, &handshakeResponse)
	if err != nil {
		return common.ContextError(err)
	}

	serverContext.clientRegion = handshakeResponse.ClientRegion
	NoticeClientRegion(serverContext.clientRegion)

	var decodedServerEntries []*protocol.ServerEntry

	// Store discovered server entries
	// We use the server's time, as it's available here, for the server entry
	// timestamp since this is more reliable than the client time.
	for _, encodedServerEntry := range handshakeResponse.EncodedServerList {

		serverEntry, err := protocol.DecodeServerEntry(
			encodedServerEntry,
			common.TruncateTimestampToHour(handshakeResponse.ServerTimestamp),
			protocol.SERVER_ENTRY_SOURCE_DISCOVERY)
		if err != nil {
			return common.ContextError(err)
		}

		err = protocol.ValidateServerEntry(serverEntry)
		if err != nil {
			// Skip this entry and continue with the next one
			NoticeAlert("invalid server entry: %s", err)
			continue
		}

		decodedServerEntries = append(decodedServerEntries, serverEntry)
	}

	// The reason we are storing the entire array of server entries at once rather
	// than one at a time is that some desirable side-effects get triggered by
	// StoreServerEntries that don't get triggered by StoreServerEntry.
	err = StoreServerEntries(decodedServerEntries, true)
	if err != nil {
		return common.ContextError(err)
	}

	// TODO: formally communicate the sponsor and upgrade info to an
	// outer client via some control interface.
	for _, homepage := range handshakeResponse.Homepages {
		NoticeHomepage(homepage)
	}

	serverContext.clientUpgradeVersion = handshakeResponse.UpgradeClientVersion
	if handshakeResponse.UpgradeClientVersion != "" {
		NoticeClientUpgradeAvailable(handshakeResponse.UpgradeClientVersion)
	} else {
		NoticeClientIsLatestVersion("")
	}

	var regexpsNotices []string
	serverContext.statsRegexps, regexpsNotices = transferstats.MakeRegexps(
		handshakeResponse.PageViewRegexes,
		handshakeResponse.HttpsRequestRegexes)

	for _, notice := range regexpsNotices {
		NoticeAlert(notice)
	}

	serverContext.serverHandshakeTimestamp = handshakeResponse.ServerTimestamp

	return nil
}