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api.go
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api.go
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/*
* Copyright (c) 2016, Psiphon Inc.
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package server
import (
"crypto/subtle"
"encoding/json"
"errors"
"fmt"
"net"
"regexp"
"runtime/debug"
"strconv"
"strings"
"unicode"
"github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon/common"
"github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon/common/protocol"
"github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon/common/tactics"
)
const (
MAX_API_PARAMS_SIZE = 256 * 1024 // 256KB
PADDING_MAX_BYTES = 16 * 1024
CLIENT_PLATFORM_ANDROID = "Android"
CLIENT_PLATFORM_WINDOWS = "Windows"
CLIENT_PLATFORM_IOS = "iOS"
)
// sshAPIRequestHandler routes Psiphon API requests transported as
// JSON objects via the SSH request mechanism.
//
// The API request handlers, handshakeAPIRequestHandler, etc., are
// reused by webServer which offers the Psiphon API via web transport.
//
// The API request parameters and event log values follow the legacy
// psi_web protocol and naming conventions. The API is compatible with
// all tunnel-core clients but are not backwards compatible with all
// legacy clients.
//
func sshAPIRequestHandler(
support *SupportServices,
geoIPData GeoIPData,
authorizedAccessTypes []string,
name string,
requestPayload []byte) ([]byte, error) {
// Notes:
//
// - For SSH requests, MAX_API_PARAMS_SIZE is implicitly enforced
// by max SSH request packet size.
//
// - The param protocol.PSIPHON_API_HANDSHAKE_AUTHORIZATIONS is an
// array of base64-encoded strings; the base64 representation should
// not be decoded to []byte values. The default behavior of
// https://golang.org/pkg/encoding/json/#Unmarshal for a target of
// type map[string]interface{} will unmarshal a base64-encoded string
// to a string, not a decoded []byte, as required.
var params common.APIParameters
err := json.Unmarshal(requestPayload, ¶ms)
if err != nil {
return nil, common.ContextError(
fmt.Errorf("invalid payload for request name: %s: %s", name, err))
}
return dispatchAPIRequestHandler(
support,
protocol.PSIPHON_SSH_API_PROTOCOL,
geoIPData,
authorizedAccessTypes,
name,
params)
}
// dispatchAPIRequestHandler is the common dispatch point for both
// web and SSH API requests.
func dispatchAPIRequestHandler(
support *SupportServices,
apiProtocol string,
geoIPData GeoIPData,
authorizedAccessTypes []string,
name string,
params common.APIParameters) (response []byte, reterr error) {
// Recover from and log any unexpected panics caused by user input
// handling bugs. User inputs should be properly validated; this
// mechanism is only a last resort to prevent the process from
// terminating in the case of a bug.
defer func() {
if e := recover(); e != nil {
if intentionalPanic, ok := e.(IntentionalPanicError); ok {
panic(intentionalPanic)
} else {
log.LogPanicRecover(e, debug.Stack())
reterr = common.ContextError(errors.New("request handler panic"))
}
}
}()
// Before invoking the handlers, enforce some preconditions:
//
// - A handshake request must precede any other requests.
// - When the handshake results in a traffic rules state where
// the client is immediately exhausted, no requests
// may succeed. This case ensures that blocked clients do
// not log "connected", etc.
//
// Only one handshake request may be made. There is no check here
// to enforce that handshakeAPIRequestHandler will be called at
// most once. The SetHandshakeState call in handshakeAPIRequestHandler
// enforces that only a single handshake is made; enforcing that there
// ensures no race condition even if concurrent requests are
// in flight.
if name != protocol.PSIPHON_API_HANDSHAKE_REQUEST_NAME {
// TODO: same session-ID-lookup TODO in handshakeAPIRequestHandler
// applies here.
sessionID, err := getStringRequestParam(params, "client_session_id")
if err == nil {
// Note: follows/duplicates baseRequestParams validation
if !isHexDigits(support.Config, sessionID) {
err = errors.New("invalid param: client_session_id")
}
}
if err != nil {
return nil, common.ContextError(err)
}
completed, exhausted, err := support.TunnelServer.GetClientHandshaked(sessionID)
if err != nil {
return nil, common.ContextError(err)
}
if !completed {
return nil, common.ContextError(errors.New("handshake not completed"))
}
if exhausted {
return nil, common.ContextError(errors.New("exhausted after handshake"))
}
}
switch name {
case protocol.PSIPHON_API_HANDSHAKE_REQUEST_NAME:
return handshakeAPIRequestHandler(support, apiProtocol, geoIPData, params)
case protocol.PSIPHON_API_CONNECTED_REQUEST_NAME:
return connectedAPIRequestHandler(support, geoIPData, authorizedAccessTypes, params)
case protocol.PSIPHON_API_STATUS_REQUEST_NAME:
return statusAPIRequestHandler(support, geoIPData, authorizedAccessTypes, params)
case protocol.PSIPHON_API_CLIENT_VERIFICATION_REQUEST_NAME:
return clientVerificationAPIRequestHandler(support, geoIPData, authorizedAccessTypes, params)
}
return nil, common.ContextError(fmt.Errorf("invalid request name: %s", name))
}
var handshakeRequestParams = append(
append(
// Note: legacy clients may not send "session_id" in handshake
[]requestParamSpec{{"session_id", isHexDigits, requestParamOptional}},
tacticsParams...),
baseRequestParams...)
// handshakeAPIRequestHandler implements the "handshake" API request.
// Clients make the handshake immediately after establishing a tunnel
// connection; the response tells the client what homepage to open, what
// stats to record, etc.
func handshakeAPIRequestHandler(
support *SupportServices,
apiProtocol string,
geoIPData GeoIPData,
params common.APIParameters) ([]byte, error) {
// Note: ignoring "known_servers" params
err := validateRequestParams(support.Config, params, baseRequestParams)
if err != nil {
return nil, common.ContextError(err)
}
sessionID, _ := getStringRequestParam(params, "client_session_id")
sponsorID, _ := getStringRequestParam(params, "sponsor_id")
clientVersion, _ := getStringRequestParam(params, "client_version")
clientPlatform, _ := getStringRequestParam(params, "client_platform")
isMobile := isMobileClientPlatform(clientPlatform)
normalizedPlatform := normalizeClientPlatform(clientPlatform)
var authorizations []string
if params[protocol.PSIPHON_API_HANDSHAKE_AUTHORIZATIONS] != nil {
authorizations, err = getStringArrayRequestParam(params, protocol.PSIPHON_API_HANDSHAKE_AUTHORIZATIONS)
if err != nil {
return nil, common.ContextError(err)
}
}
// Note: no guarantee that PsinetDatabase won't reload between database calls
db := support.PsinetDatabase
httpsRequestRegexes := db.GetHttpsRequestRegexes(sponsorID)
// Flag the SSH client as having completed its handshake. This
// may reselect traffic rules and starts allowing port forwards.
// TODO: in the case of SSH API requests, the actual sshClient could
// be passed in and used here. The session ID lookup is only strictly
// necessary to support web API requests.
activeAuthorizationIDs, authorizedAccessTypes, err := support.TunnelServer.SetClientHandshakeState(
sessionID,
handshakeState{
completed: true,
apiProtocol: apiProtocol,
apiParams: copyBaseRequestParams(params),
expectDomainBytes: len(httpsRequestRegexes) > 0,
},
authorizations)
if err != nil {
return nil, common.ContextError(err)
}
tacticsPayload, err := support.TacticsServer.GetTacticsPayload(
common.GeoIPData(geoIPData), params)
if err != nil {
return nil, common.ContextError(err)
}
var marshaledTacticsPayload []byte
if tacticsPayload != nil {
marshaledTacticsPayload, err = json.Marshal(tacticsPayload)
if err != nil {
return nil, common.ContextError(err)
}
// Log a metric when new tactics are issued. Logging here indicates that
// the handshake tactics mechanism is active; but logging for every
// handshake creates unneccesary log data.
if len(tacticsPayload.Tactics) > 0 {
logFields := getRequestLogFields(
tactics.TACTICS_METRIC_EVENT_NAME,
geoIPData,
authorizedAccessTypes,
params,
handshakeRequestParams)
logFields[tactics.NEW_TACTICS_TAG_LOG_FIELD_NAME] = tacticsPayload.Tag
logFields[tactics.IS_TACTICS_REQUEST_LOG_FIELD_NAME] = false
log.LogRawFieldsWithTimestamp(logFields)
}
}
// The log comes _after_ SetClientHandshakeState, in case that call rejects
// the state change (for example, if a second handshake is performed)
//
// The handshake event is no longer shipped to log consumers, so this is
// simply a diagnostic log. Since the "server_tunnel" event includes all
// common API parameters and "handshake_completed" flag, this handshake
// log is mostly redundant and set to debug level.
log.WithContextFields(
getRequestLogFields(
"",
geoIPData,
authorizedAccessTypes,
params,
baseRequestParams)).Debug("handshake")
pad_response, _ := getPaddingSizeRequestParam(params, "pad_response")
handshakeResponse := protocol.HandshakeResponse{
SSHSessionID: sessionID,
Homepages: db.GetRandomizedHomepages(sponsorID, geoIPData.Country, isMobile),
UpgradeClientVersion: db.GetUpgradeClientVersion(clientVersion, normalizedPlatform),
PageViewRegexes: make([]map[string]string, 0),
HttpsRequestRegexes: httpsRequestRegexes,
EncodedServerList: db.DiscoverServers(geoIPData.DiscoveryValue),
ClientRegion: geoIPData.Country,
ServerTimestamp: common.GetCurrentTimestamp(),
ActiveAuthorizationIDs: activeAuthorizationIDs,
TacticsPayload: marshaledTacticsPayload,
Padding: strings.Repeat(" ", pad_response),
}
responsePayload, err := json.Marshal(handshakeResponse)
if err != nil {
return nil, common.ContextError(err)
}
return responsePayload, nil
}
var connectedRequestParams = append(
[]requestParamSpec{
{"session_id", isHexDigits, 0},
{"last_connected", isLastConnected, 0},
{"establishment_duration", isIntString, requestParamOptional | requestParamLogStringAsInt}},
baseRequestParams...)
// updateOnConnectedParamNames are connected request parameters which are
// copied to update data logged with server_tunnel: these fields either only
// ship with or ship newer data with connected requests.
var updateOnConnectedParamNames = []string{
"last_connected",
"establishment_duration",
"upstream_bytes_fragmented",
"upstream_min_bytes_written",
"upstream_max_bytes_written",
"upstream_min_delayed",
"upstream_max_delayed",
}
// connectedAPIRequestHandler implements the "connected" API request.
// Clients make the connected request once a tunnel connection has been
// established and at least once per day. The last_connected input value,
// which should be a connected_timestamp output from a previous connected
// response, is used to calculate unique user stats.
// connected_timestamp is truncated as a privacy measure.
func connectedAPIRequestHandler(
support *SupportServices,
geoIPData GeoIPData,
authorizedAccessTypes []string,
params common.APIParameters) ([]byte, error) {
err := validateRequestParams(support.Config, params, connectedRequestParams)
if err != nil {
return nil, common.ContextError(err)
}
// Update, for server_tunnel logging, upstream fragmentor metrics, as the
// client may have performed more upstream fragmentation since the
// previous metrics reported by the handshake request. Also, additional
// fields reported only in the connected request, are added to
// server_tunnel here.
// TODO: same session-ID-lookup TODO in handshakeAPIRequestHandler
// applies here.
sessionID, _ := getStringRequestParam(params, "client_session_id")
err = support.TunnelServer.UpdateClientAPIParameters(
sessionID, copyUpdateOnConnectedParams(params))
if err != nil {
return nil, common.ContextError(err)
}
log.LogRawFieldsWithTimestamp(
getRequestLogFields(
"connected",
geoIPData,
authorizedAccessTypes,
params,
connectedRequestParams))
pad_response, _ := getPaddingSizeRequestParam(params, "pad_response")
connectedResponse := protocol.ConnectedResponse{
ConnectedTimestamp: common.TruncateTimestampToHour(common.GetCurrentTimestamp()),
Padding: strings.Repeat(" ", pad_response),
}
responsePayload, err := json.Marshal(connectedResponse)
if err != nil {
return nil, common.ContextError(err)
}
return responsePayload, nil
}
var statusRequestParams = append(
[]requestParamSpec{
{"session_id", isHexDigits, 0},
{"connected", isBooleanFlag, requestParamLogFlagAsBool}},
baseRequestParams...)
var remoteServerListStatParams = []requestParamSpec{
{"session_id", isHexDigits, requestParamOptional},
{"propagation_channel_id", isHexDigits, requestParamOptional},
{"sponsor_id", isHexDigits, requestParamOptional},
{"client_version", isAnyString, requestParamOptional},
{"client_platform", isAnyString, requestParamOptional},
{"client_build_rev", isAnyString, requestParamOptional},
{"client_download_timestamp", isISO8601Date, 0},
{"url", isAnyString, 0},
{"etag", isAnyString, 0},
}
var failedTunnelStatParams = append(
[]requestParamSpec{
{"server_entry_ip_address", isIPAddress, requestParamNotLogged},
{"session_id", isHexDigits, 0},
{"last_connected", isLastConnected, 0},
{"client_failed_timestamp", isISO8601Date, 0},
{"tunnel_error", isAnyString, 0}},
baseRequestParams...)
// statusAPIRequestHandler implements the "status" API request.
// Clients make periodic status requests which deliver client-side
// recorded data transfer and tunnel duration stats.
// Note from psi_web implementation: no input validation on domains;
// any string is accepted (regex transform may result in arbitrary
// string). Stats processor must handle this input with care.
func statusAPIRequestHandler(
support *SupportServices,
geoIPData GeoIPData,
authorizedAccessTypes []string,
params common.APIParameters) ([]byte, error) {
err := validateRequestParams(support.Config, params, statusRequestParams)
if err != nil {
return nil, common.ContextError(err)
}
sessionID, _ := getStringRequestParam(params, "client_session_id")
statusData, err := getJSONObjectRequestParam(params, "statusData")
if err != nil {
return nil, common.ContextError(err)
}
// Logs are queued until the input is fully validated. Otherwise, stats
// could be double counted if the client has a bug in its request
// formatting: partial stats would be logged (counted), the request would
// fail, and clients would then resend all the same stats again.
logQueue := make([]LogFields, 0)
// Domain bytes transferred stats
// Older clients may not submit this data
// Clients are expected to send host_bytes/domain_bytes stats only when
// configured to do so in the handshake reponse. Legacy clients may still
// report "(OTHER)" host_bytes when no regexes are set. Drop those stats.
domainBytesExpected, err := support.TunnelServer.ExpectClientDomainBytes(sessionID)
if err != nil {
return nil, common.ContextError(err)
}
if domainBytesExpected && statusData["host_bytes"] != nil {
hostBytes, err := getMapStringInt64RequestParam(statusData, "host_bytes")
if err != nil {
return nil, common.ContextError(err)
}
for domain, bytes := range hostBytes {
domainBytesFields := getRequestLogFields(
"domain_bytes",
geoIPData,
authorizedAccessTypes,
params,
statusRequestParams)
domainBytesFields["domain"] = domain
domainBytesFields["bytes"] = bytes
logQueue = append(logQueue, domainBytesFields)
}
}
// Limitation: for "persistent" stats, host_id and geolocation is time-of-sending
// not time-of-recording.
// Remote server list download persistent stats.
// Older clients may not submit this data.
if statusData["remote_server_list_stats"] != nil {
remoteServerListStats, err := getJSONObjectArrayRequestParam(statusData, "remote_server_list_stats")
if err != nil {
return nil, common.ContextError(err)
}
for _, remoteServerListStat := range remoteServerListStats {
err := validateRequestParams(support.Config, remoteServerListStat, remoteServerListStatParams)
if err != nil {
return nil, common.ContextError(err)
}
// remote_server_list defaults to using the common params from the
// outer statusRequestParams
remoteServerListFields := getRequestLogFields(
"remote_server_list",
geoIPData,
authorizedAccessTypes,
params,
statusRequestParams)
for name, value := range remoteServerListStat {
remoteServerListFields[name] = value
}
logQueue = append(logQueue, remoteServerListFields)
}
}
// Failed tunnel persistent stats.
// Older clients may not submit this data.
if statusData["failed_tunnel_stats"] != nil {
failedTunnelStats, err := getJSONObjectArrayRequestParam(statusData, "failed_tunnel_stats")
if err != nil {
return nil, common.ContextError(err)
}
for _, failedTunnelStat := range failedTunnelStats {
// failed_tunnel supplies a full set of common params, but the
// server secret must use the corect value from the outer
// statusRequestParams
failedTunnelStat["server_secret"] = params["server_secret"]
err := validateRequestParams(support.Config, failedTunnelStat, failedTunnelStatParams)
if err != nil {
return nil, common.ContextError(err)
}
failedTunnelFields := getRequestLogFields(
"failed_tunnel",
geoIPData,
authorizedAccessTypes,
failedTunnelStat,
failedTunnelStatParams)
logQueue = append(logQueue, failedTunnelFields)
}
}
for _, logItem := range logQueue {
log.LogRawFieldsWithTimestamp(logItem)
}
pad_response, _ := getPaddingSizeRequestParam(params, "pad_response")
return make([]byte, pad_response), nil
}
// clientVerificationAPIRequestHandler is just a compliance stub
// for older Android clients that still send verification requests
func clientVerificationAPIRequestHandler(
support *SupportServices,
geoIPData GeoIPData,
authorizedAccessTypes []string,
params common.APIParameters) ([]byte, error) {
return make([]byte, 0), nil
}
var tacticsParams = []requestParamSpec{
{tactics.STORED_TACTICS_TAG_PARAMETER_NAME, isAnyString, requestParamOptional},
{tactics.SPEED_TEST_SAMPLES_PARAMETER_NAME, nil, requestParamOptional | requestParamJSON},
}
var tacticsRequestParams = append(
append(
[]requestParamSpec{{"session_id", isHexDigits, 0}},
tacticsParams...),
baseRequestParams...)
func getTacticsAPIParameterValidator(config *Config) common.APIParameterValidator {
return func(params common.APIParameters) error {
return validateRequestParams(config, params, tacticsRequestParams)
}
}
func getTacticsAPIParameterLogFieldFormatter() common.APIParameterLogFieldFormatter {
return func(geoIPData common.GeoIPData, params common.APIParameters) common.LogFields {
logFields := getRequestLogFields(
tactics.TACTICS_METRIC_EVENT_NAME,
GeoIPData(geoIPData),
nil, // authorizedAccessTypes are not known yet
params,
tacticsRequestParams)
return common.LogFields(logFields)
}
}
type requestParamSpec struct {
name string
validator func(*Config, string) bool
flags uint32
}
const (
requestParamOptional = 1
requestParamNotLogged = 1 << 1
requestParamArray = 1 << 2
requestParamJSON = 1 << 3
requestParamLogStringAsInt = 1 << 4
requestParamLogStringLengthAsInt = 1 << 5
requestParamLogFlagAsBool = 1 << 6
requestParamLogOnlyForFrontedMeek = 1 << 7
requestParamNotLoggedForUnfrontedMeekNonTransformedHeader = 1 << 8
)
// baseRequestParams is the list of required and optional
// request parameters; derived from COMMON_INPUTS and
// OPTIONAL_COMMON_INPUTS in psi_web.
// Each param is expected to be a string, unless requestParamArray
// is specified, in which case an array of string is expected.
var baseRequestParams = []requestParamSpec{
{"server_secret", isServerSecret, requestParamNotLogged},
{"client_session_id", isHexDigits, requestParamNotLogged},
{"propagation_channel_id", isHexDigits, 0},
{"sponsor_id", isHexDigits, 0},
{"client_version", isIntString, requestParamLogStringAsInt},
{"client_platform", isClientPlatform, 0},
{"client_build_rev", isHexDigits, requestParamOptional},
{"relay_protocol", isRelayProtocol, 0},
{"tunnel_whole_device", isBooleanFlag, requestParamOptional | requestParamLogFlagAsBool},
{"device_region", isAnyString, requestParamOptional},
{"ssh_client_version", isAnyString, requestParamOptional},
{"upstream_proxy_type", isUpstreamProxyType, requestParamOptional},
{"upstream_proxy_custom_header_names", isAnyString, requestParamOptional | requestParamArray},
{"meek_dial_address", isDialAddress, requestParamOptional | requestParamLogOnlyForFrontedMeek},
{"meek_resolved_ip_address", isIPAddress, requestParamOptional | requestParamLogOnlyForFrontedMeek},
{"meek_sni_server_name", isDomain, requestParamOptional},
{"meek_host_header", isHostHeader, requestParamOptional | requestParamNotLoggedForUnfrontedMeekNonTransformedHeader},
{"meek_transformed_host_name", isBooleanFlag, requestParamOptional | requestParamLogFlagAsBool},
{"user_agent", isAnyString, requestParamOptional},
{"tls_profile", isAnyString, requestParamOptional},
{"server_entry_region", isRegionCode, requestParamOptional},
{"server_entry_source", isServerEntrySource, requestParamOptional},
{"server_entry_timestamp", isISO8601Date, requestParamOptional},
{tactics.APPLIED_TACTICS_TAG_PARAMETER_NAME, isAnyString, requestParamOptional},
{"dial_port_number", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"quic_version", isAnyString, requestParamOptional},
{"quic_dial_sni_address", isAnyString, requestParamOptional},
{"upstream_bytes_fragmented", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"upstream_min_bytes_written", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"upstream_max_bytes_written", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"upstream_min_delayed", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"upstream_max_delayed", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"padding", isAnyString, requestParamOptional | requestParamLogStringLengthAsInt},
{"pad_response", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"is_replay", isBooleanFlag, requestParamOptional | requestParamLogFlagAsBool},
{"egress_region", isRegionCode, requestParamOptional},
{"dial_duration", isIntString, requestParamOptional | requestParamLogStringAsInt},
{"candidate_number", isIntString, requestParamOptional | requestParamLogStringAsInt},
}
func validateRequestParams(
config *Config,
params common.APIParameters,
expectedParams []requestParamSpec) error {
for _, expectedParam := range expectedParams {
value := params[expectedParam.name]
if value == nil {
if expectedParam.flags&requestParamOptional != 0 {
continue
}
return common.ContextError(
fmt.Errorf("missing param: %s", expectedParam.name))
}
var err error
switch {
case expectedParam.flags&requestParamArray != 0:
err = validateStringArrayRequestParam(config, expectedParam, value)
case expectedParam.flags&requestParamJSON != 0:
// No validation: the JSON already unmarshalled; the parameter
// user will validate that the JSON contains the expected
// objects/data.
// TODO: without validation, any valid JSON will be logged
// by getRequestLogFields, even if the parameter user validates
// and rejects the parameter.
default:
err = validateStringRequestParam(config, expectedParam, value)
}
if err != nil {
return common.ContextError(err)
}
}
return nil
}
// copyBaseRequestParams makes a copy of the params which
// includes only the baseRequestParams.
func copyBaseRequestParams(params common.APIParameters) common.APIParameters {
// Note: not a deep copy; assumes baseRequestParams values
// are all scalar types (int, string, etc.)
paramsCopy := make(common.APIParameters)
for _, baseParam := range baseRequestParams {
value := params[baseParam.name]
if value == nil {
continue
}
paramsCopy[baseParam.name] = value
}
return paramsCopy
}
func copyUpdateOnConnectedParams(params common.APIParameters) common.APIParameters {
// Note: not a deep copy
paramsCopy := make(common.APIParameters)
for _, name := range updateOnConnectedParamNames {
value := params[name]
if value == nil {
continue
}
paramsCopy[name] = value
}
return paramsCopy
}
func validateStringRequestParam(
config *Config,
expectedParam requestParamSpec,
value interface{}) error {
strValue, ok := value.(string)
if !ok {
return common.ContextError(
fmt.Errorf("unexpected string param type: %s", expectedParam.name))
}
if !expectedParam.validator(config, strValue) {
return common.ContextError(
fmt.Errorf("invalid param: %s: %s", expectedParam.name, strValue))
}
return nil
}
func validateStringArrayRequestParam(
config *Config,
expectedParam requestParamSpec,
value interface{}) error {
arrayValue, ok := value.([]interface{})
if !ok {
return common.ContextError(
fmt.Errorf("unexpected string param type: %s", expectedParam.name))
}
for _, value := range arrayValue {
err := validateStringRequestParam(config, expectedParam, value)
if err != nil {
return common.ContextError(err)
}
}
return nil
}
// getRequestLogFields makes LogFields to log the API event following
// the legacy psi_web and current ELK naming conventions.
func getRequestLogFields(
eventName string,
geoIPData GeoIPData,
authorizedAccessTypes []string,
params common.APIParameters,
expectedParams []requestParamSpec) LogFields {
logFields := make(LogFields)
if eventName != "" {
logFields["event_name"] = eventName
}
// In psi_web, the space replacement was done to accommodate space
// delimited logging, which is no longer required; we retain the
// transformation so that stats aggregation isn't impacted.
logFields["client_region"] = strings.Replace(geoIPData.Country, " ", "_", -1)
logFields["client_city"] = strings.Replace(geoIPData.City, " ", "_", -1)
logFields["client_isp"] = strings.Replace(geoIPData.ISP, " ", "_", -1)
if len(authorizedAccessTypes) > 0 {
logFields["authorized_access_types"] = authorizedAccessTypes
}
if params == nil {
return logFields
}
for _, expectedParam := range expectedParams {
if expectedParam.flags&requestParamNotLogged != 0 {
continue
}
var tunnelProtocol string
if value, ok := params["relay_protocol"]; ok {
tunnelProtocol, _ = value.(string)
}
if expectedParam.flags&requestParamLogOnlyForFrontedMeek != 0 &&
!protocol.TunnelProtocolUsesFrontedMeek(tunnelProtocol) {
continue
}
if expectedParam.flags&requestParamNotLoggedForUnfrontedMeekNonTransformedHeader != 0 &&
protocol.TunnelProtocolUsesMeek(tunnelProtocol) &&
!protocol.TunnelProtocolUsesFrontedMeek(tunnelProtocol) {
// Non-HTTP unfronted meek protocols never tranform the host header.
if !protocol.TunnelProtocolUsesMeekHTTPS(tunnelProtocol) {
continue
}
var transformedHostName string
if value, ok := params["meek_transformed_host_name"]; ok {
transformedHostName, _ = value.(string)
}
if transformedHostName != "1" {
continue
}
}
value := params[expectedParam.name]
if value == nil {
// Special case: older clients don't send this value,
// so log a default.
if expectedParam.name == "tunnel_whole_device" {
value = "0"
} else {
// Skip omitted, optional params
continue
}
}
switch v := value.(type) {
case string:
strValue := v
// Special cases:
// - Number fields are encoded as integer types.
// - For ELK performance we record certain domain-or-IP
// fields as one of two different values based on type;
// we also omit port from these host:port fields for now.
// - Boolean fields that come into the api as "1"/"0"
// must be logged as actual boolean values
switch expectedParam.name {
case "meek_dial_address":
host, _, _ := net.SplitHostPort(strValue)
if isIPAddress(nil, host) {
logFields["meek_dial_ip_address"] = host
} else {
logFields["meek_dial_domain"] = host
}
case "upstream_proxy_type":
// Submitted value could be e.g., "SOCKS5" or "socks5"; log lowercase
logFields[expectedParam.name] = strings.ToLower(strValue)
case tactics.SPEED_TEST_SAMPLES_PARAMETER_NAME:
// Due to a client bug, clients may deliever an incorrect ""
// value for speed_test_samples via the web API protocol. Omit
// the field in this case.
default:
if expectedParam.flags&requestParamLogStringAsInt != 0 {
intValue, _ := strconv.Atoi(strValue)
logFields[expectedParam.name] = intValue
} else if expectedParam.flags&requestParamLogStringLengthAsInt != 0 {
logFields[expectedParam.name] = len(strValue)
} else if expectedParam.flags&requestParamLogFlagAsBool != 0 {
// Submitted value could be "0" or "1"
// "0" and non "0"/"1" values should be transformed to false
// "1" should be transformed to true
if strValue == "1" {
logFields[expectedParam.name] = true
} else {
logFields[expectedParam.name] = false
}
} else {
logFields[expectedParam.name] = strValue
}
}
case []interface{}:
if expectedParam.name == tactics.SPEED_TEST_SAMPLES_PARAMETER_NAME {
logFields[expectedParam.name] = makeSpeedTestSamplesLogField(v)
} else {
logFields[expectedParam.name] = v
}
default:
logFields[expectedParam.name] = v
}
}
return logFields
}
// makeSpeedTestSamplesLogField renames the tactics.SpeedTestSample json tag
// fields to more verbose names for metrics.
func makeSpeedTestSamplesLogField(samples []interface{}) []interface{} {
// TODO: use reflection and add additional tags, e.g.,
// `json:"s" log:"timestamp"` to remove hard-coded
// tag value dependency?
logSamples := make([]interface{}, len(samples))
for i, sample := range samples {
logSample := make(map[string]interface{})
if m, ok := sample.(map[string]interface{}); ok {
for k, v := range m {
logK := k
switch k {
case "s":
logK = "timestamp"
case "r":
logK = "server_region"
case "p":
logK = "relay_protocol"
case "t":
logK = "round_trip_time_ms"
case "u":
logK = "bytes_up"
case "d":
logK = "bytes_down"
}
logSample[logK] = v
}
}
logSamples[i] = logSample
}
return logSamples
}
func getStringRequestParam(params common.APIParameters, name string) (string, error) {
if params[name] == nil {
return "", common.ContextError(fmt.Errorf("missing param: %s", name))
}
value, ok := params[name].(string)
if !ok {
return "", common.ContextError(fmt.Errorf("invalid param: %s", name))
}
return value, nil
}
func getInt64RequestParam(params common.APIParameters, name string) (int64, error) {
if params[name] == nil {
return 0, common.ContextError(fmt.Errorf("missing param: %s", name))
}
value, ok := params[name].(float64)
if !ok {
return 0, common.ContextError(fmt.Errorf("invalid param: %s", name))
}
return int64(value), nil
}
func getPaddingSizeRequestParam(params common.APIParameters, name string) (int, error) {
value, err := getInt64RequestParam(params, name)
if err != nil {
return 0, common.ContextError(err)
}
if value < 0 {
value = 0
}
if value > PADDING_MAX_BYTES {
value = PADDING_MAX_BYTES
}
return int(value), nil
}
func getJSONObjectRequestParam(params common.APIParameters, name string) (common.APIParameters, error) {
if params[name] == nil {
return nil, common.ContextError(fmt.Errorf("missing param: %s", name))
}
// Note: generic unmarshal of JSON produces map[string]interface{}, not common.APIParameters
value, ok := params[name].(map[string]interface{})
if !ok {
return nil, common.ContextError(fmt.Errorf("invalid param: %s", name))
}
return common.APIParameters(value), nil
}
func getJSONObjectArrayRequestParam(params common.APIParameters, name string) ([]common.APIParameters, error) {
if params[name] == nil {
return nil, common.ContextError(fmt.Errorf("missing param: %s", name))
}
value, ok := params[name].([]interface{})
if !ok {
return nil, common.ContextError(fmt.Errorf("invalid param: %s", name))