server

package
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 Go to latest Published: Feb 14, 2017 License: GPL-3.0 Imports: 52 Imported by: 0

Documentation

Overview

Package psiphon/server implements the core tunnel functionality of a Psiphon server. The main function is RunServices, which runs one or all of a Psiphon API web server, a tunneling SSH server, and an Obfuscated SSH protocol server. The server configuration is created by the GenerateConfig function.

Index

Constants

View Source 
const (
	MAX_API_PARAMS_SIZE = 256 * 1024 // 256KB

	CLIENT_VERIFICATION_TTL_SECONDS = 60 * 60 * 24 * 7 // 7 days

	CLIENT_PLATFORM_ANDROID = "Android"
	CLIENT_PLATFORM_WINDOWS = "Windows"
)
View Source 
const (
	SERVER_CONFIG_FILENAME          = "psiphond.config"
	SERVER_TRAFFIC_RULES_FILENAME   = "psiphond-traffic-rules.config"
	SERVER_ENTRY_FILENAME           = "server-entry.dat"
	DEFAULT_SERVER_IP_ADDRESS       = "127.0.0.1"
	WEB_SERVER_SECRET_BYTE_LENGTH   = 32
	DISCOVERY_VALUE_KEY_BYTE_LENGTH = 32
	SSH_USERNAME_SUFFIX_BYTE_LENGTH = 8
	SSH_PASSWORD_BYTE_LENGTH        = 32
	SSH_RSA_HOST_KEY_BITS           = 2048
	SSH_OBFUSCATED_KEY_BYTE_LENGTH  = 32
)
View Source 
const (
	DNS_SYSTEM_CONFIG_FILENAME      = "/etc/resolv.conf"
	DNS_SYSTEM_CONFIG_RELOAD_PERIOD = 5 * time.Second
	DNS_RESOLVER_PORT               = 53
)
View Source 
const (
	GEOIP_SESSION_CACHE_TTL = 60 * time.Minute
	GEOIP_UNKNOWN_VALUE     = "None"
)
View Source 
const (

	// Protocol version 1 clients can handle arbitrary length response bodies. Older clients
	// report no version number and expect at most 64K response bodies.
	MEEK_PROTOCOL_VERSION_1 = 1

	// Protocol version 2 clients initiate a session by sending a encrypted and obfuscated meek
	// cookie with their initial HTTP request. Connection information is contained within the
	// encrypted cookie payload. The server inspects the cookie and establishes a new session and
	// returns a new random session ID back to client via Set-Cookie header. The client uses this
	// session ID on all subsequent requests for the remainder of the session.
	MEEK_PROTOCOL_VERSION_2 = 2

	MEEK_MAX_PAYLOAD_LENGTH           = 0x10000
	MEEK_TURN_AROUND_TIMEOUT          = 20 * time.Millisecond
	MEEK_EXTENDED_TURN_AROUND_TIMEOUT = 100 * time.Millisecond
	MEEK_MAX_SESSION_STALENESS        = 45 * time.Second
	MEEK_HTTP_CLIENT_IO_TIMEOUT       = 45 * time.Second
	MEEK_MIN_SESSION_ID_LENGTH        = 8
	MEEK_MAX_SESSION_ID_LENGTH        = 20
)
View Source 
const (
	DEFAULT_IDLE_TCP_PORT_FORWARD_TIMEOUT_MILLISECONDS = 30000
	DEFAULT_IDLE_UDP_PORT_FORWARD_TIMEOUT_MILLISECONDS = 30000
	DEFAULT_MAX_TCP_PORT_FORWARD_COUNT                 = 512
	DEFAULT_MAX_UDP_PORT_FORWARD_COUNT                 = 32
)
View Source 
const (
	SSH_HANDSHAKE_TIMEOUT                  = 30 * time.Second
	SSH_CONNECTION_READ_DEADLINE           = 5 * time.Minute
	SSH_TCP_PORT_FORWARD_IP_LOOKUP_TIMEOUT = 30 * time.Second
	SSH_TCP_PORT_FORWARD_DIAL_TIMEOUT      = 30 * time.Second
	SSH_TCP_PORT_FORWARD_COPY_BUFFER_SIZE  = 8192
	SSH_SEND_OSL_INITIAL_RETRY_DELAY       = 30 * time.Second
	SSH_SEND_OSL_RETRY_FACTOR              = 2
)
View Source 
const WEB_SERVER_IO_TIMEOUT = 10 * time.Second

Variables

View Source 
var CLIENT_VERIFICATION_REQUIRED = false

Functions

func GenerateConfig 

func GenerateConfig(params *GenerateConfigParams) ([]byte, []byte, []byte, error)

GenerateConfig creates a new Psiphon server config. It returns JSON encoded configs and a client-compatible "server entry" for the server. It generates all necessary secrets and key material, which are emitted in the config file and server entry as necessary. GenerateConfig uses sample values for many fields. The intention is for generated configs to be used for testing or as a template for production setup, not to generate production-ready configurations.

func GenerateWebServerCertificate 

func GenerateWebServerCertificate(commonName string) (string, string, error)

GenerateWebServerCertificate creates a self-signed web server certificate, using the specified host name (commonName). This is primarily intended for use by MeekServer to generate on-the-fly, self-signed TLS certificates for fronted HTTPS mode. In this case, the nature of the certificate is non-circumvention; it only has to be acceptable to the front CDN making connections to meek. The same certificates are used for unfronted HTTPS meek. In this case, the certificates may be a fingerprint used to detect Psiphon servers or traffic. TODO: more effort to mitigate fingerprinting these certificates.

In addition, GenerateWebServerCertificate is used by GenerateConfig to create Psiphon web server certificates for test/example configurations. If these Psiphon web server certificates are used in production, the same caveats about fingerprints apply.

func InitLogging 

func InitLogging(config *Config) (retErr error)

InitLogging configures a logger according to the specified config params. If not called, the default logger set by the package init() is used. Concurrency notes: this should only be called from the main goroutine; InitLogging only has effect on the first call, as the logging facilities it initializes may be in use by other goroutines after that point.

func NewLogWriter 

func NewLogWriter() *io.PipeWriter

NewLogWriter returns an io.PipeWriter that can be used to write to the global logger. Caller must Close() the writer.

func RunServices 

func RunServices(configJSON []byte) error

RunServices initializes support functions including logging and GeoIP services; and then starts the server components and runs them until os.Interrupt or os.Kill signals are received. The config determines which components are run.

func RunWebServer 

func RunWebServer(
	support *SupportServices,
	shutdownBroadcast <-chan struct{}) error

RunWebServer runs a web server which supports tunneled and untunneled Psiphon API requests.

The HTTP request handlers are light wrappers around the base Psiphon API request handlers from the SSH API transport. The SSH API transport is preferred by new clients; however the web API transport is still required for untunneled final status requests. The web API transport may be retired once untunneled final status requests are made obsolete (e.g., by server-side bytes transferred stats, by client-side local storage of stats for retry, or some other future development).

The API is compatible with all tunnel-core clients but not backwards compatible with older clients.

Types

type Config 

type Config struct {

	// LogLevel specifies the log level. Valid values are:
	// panic, fatal, error, warn, info, debug
	LogLevel string

	// LogFilename specifies the path of the file to log
	// to. When blank, logs are written to stderr.
	LogFilename string

	// DiscoveryValueHMACKey is the network-wide secret value
	// used to determine a unique discovery strategy.
	DiscoveryValueHMACKey string

	// GeoIPDatabaseFilenames are paths of GeoIP2/GeoLite2
	// MaxMind database files. When empty, no GeoIP lookups are
	// performed. Each file is queried, in order, for the
	// logged fields: country code, city, and ISP. Multiple
	// file support accomodates the MaxMind distribution where
	// ISP data in a separate file.
	GeoIPDatabaseFilenames []string

	// PsinetDatabaseFilename is the path of the Psiphon automation
	// jsonpickle format Psiphon API data file.
	PsinetDatabaseFilename string

	// HostID is the ID of the server host; this is used for API
	// event logging.
	HostID string

	// ServerIPAddress is the public IP address of the server.
	ServerIPAddress string

	// WebServerPort is the listening port of the web server.
	// When <= 0, no web server component is run.
	WebServerPort int

	// WebServerSecret is the unique secret value that the client
	// must supply to make requests to the web server.
	WebServerSecret string

	// WebServerCertificate is the certificate the client uses to
	// authenticate the web server.
	WebServerCertificate string

	// WebServerPrivateKey is the private key the web server uses to
	// authenticate itself to clients.
	WebServerPrivateKey string

	// WebServerPortForwardAddress specifies the expected network
	// address ("<host>:<port>") specified in a client's port forward
	// HostToConnect and PortToConnect when the client is making a
	// tunneled connection to the web server. This address is always
	// exempted from validation against SSH_DISALLOWED_PORT_FORWARD_HOSTS
	// and AllowTCPPorts.
	WebServerPortForwardAddress string

	// WebServerPortForwardRedirectAddress specifies an alternate
	// destination address to be substituted and dialed instead of
	// the original destination when the port forward destination is
	// WebServerPortForwardAddress.
	WebServerPortForwardRedirectAddress string

	// TunnelProtocolPorts specifies which tunnel protocols to run
	// and which ports to listen on for each protocol. Valid tunnel
	// protocols include: "SSH", "OSSH", "UNFRONTED-MEEK-OSSH",
	// "UNFRONTED-MEEK-HTTPS-OSSH", "FRONTED-MEEK-OSSH",
	// "FRONTED-MEEK-HTTP-OSSH".
	TunnelProtocolPorts map[string]int

	// SSHPrivateKey is the SSH host key. The same key is used for
	// all protocols, run by this server instance, which use SSH.
	SSHPrivateKey string

	// SSHServerVersion is the server version presented in the
	// identification string. The same value is used for all
	// protocols, run by this server instance, which use SSH.
	SSHServerVersion string

	// SSHUserName is the SSH user name to be presented by the
	// the tunnel-core client. The same value is used for all
	// protocols, run by this server instance, which use SSH.
	SSHUserName string

	// SSHPassword is the SSH password to be presented by the
	// the tunnel-core client. The same value is used for all
	// protocols, run by this server instance, which use SSH.
	SSHPassword string

	// ObfuscatedSSHKey is the secret key for use in the Obfuscated
	// SSH protocol. The same secret key is used for all protocols,
	// run by this server instance, which use Obfuscated SSH.
	ObfuscatedSSHKey string

	// MeekCookieEncryptionPrivateKey is the NaCl private key used
	// to decrypt meek cookie payload sent from clients. The same
	// key is used for all meek protocols run by this server instance.
	MeekCookieEncryptionPrivateKey string

	// MeekObfuscatedKey is the secret key used for obfuscating
	// meek cookies sent from clients. The same key is used for all
	// meek protocols run by this server instance.
	MeekObfuscatedKey string

	// MeekProhibitedHeaders is a list of HTTP headers to check for
	// in client requests. If one of these headers is found, the
	// request fails. This is used to defend against abuse.
	MeekProhibitedHeaders []string

	// MeekProxyForwardedForHeaders is a list of HTTP headers which
	// may be added by downstream HTTP proxies or CDNs in front
	// of clients. These headers supply the original client IP
	// address, which is geolocated for stats purposes. Headers
	// include, for example, X-Forwarded-For. The header's value
	// is assumed to be a comma delimted list of IP addresses where
	// the client IP is the first IP address in the list. Meek protocols
	// look for these headers and use the client IP address from
	// the header if any one is present and the value is a valid
	// IP address; otherwise the direct connection remote address is
	// used as the client IP.
	MeekProxyForwardedForHeaders []string

	// UDPInterceptUdpgwServerAddress specifies the network address of
	// a udpgw server which clients may be port forwarding to. When
	// specified, these TCP port forwards are intercepted and handled
	// directly by this server, which parses the SSH channel using the
	// udpgw protocol. Handling includes udpgw transparent DNS: tunneled
	// UDP DNS packets are rerouted to the host's DNS server.
	//
	// The intercept is applied before the port forward destination is
	// validated against SSH_DISALLOWED_PORT_FORWARD_HOSTS and
	// AllowTCPPorts. So the intercept address may be any otherwise
	// prohibited destination.
	UDPInterceptUdpgwServerAddress string

	// DNSResolverIPAddress specifies the IP address of a DNS server
	// to be used when "/etc/resolv.conf" doesn't exist or fails to
	// parse. When blank, "/etc/resolv.conf" must contain a usable
	// "nameserver" entry.
	DNSResolverIPAddress string

	// LoadMonitorPeriodSeconds indicates how frequently to log server
	// load information (number of connected clients per tunnel protocol,
	// number of running goroutines, amount of memory allocated, etc.)
	// The default, 0, disables load logging.
	LoadMonitorPeriodSeconds int

	// ProcessProfileOutputDirectory is the path of a directory to which
	// process profiles will be written when signaled with SIGUSR2. The
	// files are overwritten on each invocation. When set to the default
	// value, blank, no profiles are written on SIGUSR2. Profiles include
	// the default profiles here: https://golang.org/pkg/runtime/pprof/#Profile.
	ProcessProfileOutputDirectory string

	// ProcessBlockProfileDurationSeconds specifies the sample duration for
	// "block" profiling. For the default, 0, no "block" profile is taken.
	ProcessBlockProfileDurationSeconds int

	// ProcessCPUProfileDurationSeconds specifies the sample duration for
	// CPU profiling. For the default, 0, no CPU profile is taken.
	ProcessCPUProfileDurationSeconds int

	// TrafficRulesFilename is the path of a file containing a JSON-encoded
	// TrafficRulesSet, the traffic rules to apply to Psiphon client tunnels.
	TrafficRulesFilename string

	// OSLConfigFilename is the path of a file containing a JSON-encoded
	// OSL Config, the OSL schemes to apply to Psiphon client tunnels.
	OSLConfigFilename string
}

Config specifies the configuration and behavior of a Psiphon server.

func LoadConfig 

func LoadConfig(configJSON []byte) (*Config, error)

LoadConfig loads and validates a JSON encoded server config.

func (*Config) RunLoadMonitor 

func (config *Config) RunLoadMonitor() bool

RunLoadMonitor indicates whether to monitor and log server load.

func (*Config) RunWebServer 

func (config *Config) RunWebServer() bool

RunWebServer indicates whether to run a web server component.

type ContextLogger 

type ContextLogger struct {
	*logrus.Logger
}

ContextLogger adds context logging functionality to the underlying logging packages.

func (*ContextLogger) LogPanicRecover 

func (logger *ContextLogger) LogPanicRecover(recoverValue interface{}, stack []byte)

LogPanicRecover calls LogRawFieldsWithTimestamp with standard fields for logging recovered panics.

func (*ContextLogger) LogRawFieldsWithTimestamp 

func (logger *ContextLogger) LogRawFieldsWithTimestamp(fields LogFields)

LogRawFieldsWithTimestamp directly logs the supplied fields adding only an additional "timestamp" field; and "host_id" and "build_rev" fields identifying this server and build. The stock "msg" and "level" fields are omitted. This log is emitted at the Error level. This function exists to support API logs which have neither a natural message nor severity; and omitting these values here makes it easier to ship these logs to existing API log consumers. Note that any existing "context"/"host_id"/"build_rev" field will be renamed to "field.<name>".

func (*ContextLogger) WithContext 

func (logger *ContextLogger) WithContext() *logrus.Entry

WithContext adds a "context" field containing the caller's function name and source file line number; and "host_id" and "build_rev" fields identifying this server and build. Use this function when the log has no fields.

func (*ContextLogger) WithContextFields 

func (logger *ContextLogger) WithContextFields(fields LogFields) *logrus.Entry

WithContextFields adds a "context" field containing the caller's function name and source file line number; and "host_id" and "build_rev" fields identifying this server and build. Use this function when the log has fields. Note that any existing "context"/"host_id"/"build_rev" field will be renamed to "field.<name>".

type CustomJSONFormatter 

type CustomJSONFormatter struct {
}

CustomJSONFormatter is a customized version of logrus.JSONFormatter

func (*CustomJSONFormatter) Format 

func (f *CustomJSONFormatter) Format(entry *logrus.Entry) ([]byte, error)

Format implements logrus.Formatter. This is a customized version of the standard logrus.JSONFormatter adapted from: https://github.com/Sirupsen/logrus/blob/f1addc29722ba9f7651bc42b4198d0944b66e7c4/json_formatter.go

The changes are: - "time" is renamed to "timestamp" - there's an option to omit the standard "msg" and "level" fields

type DNSResolver 

type DNSResolver struct {
	common.ReloadableFile
	// contains filtered or unexported fields
}

DNSResolver maintains a fresh DNS resolver value, monitoring "/etc/resolv.conf" on platforms where it is available; and otherwise using a default value.

func NewDNSResolver 

func NewDNSResolver(defaultResolver string) (*DNSResolver, error)

NewDNSResolver initializes a new DNSResolver, loading it with a fresh resolver value. The load must succeed, so either "/etc/resolv.conf" must contain a valid "nameserver" line with a DNS server IP address, or a valid "defaultResolver" default value must be provided. On systems without "/etc/resolv.conf", "defaultResolver" is required.

The resolver is considered stale and reloaded if last checked more than 5 seconds before the last Get(), which is similar to frequencies in other implementations:

func (*DNSResolver) Get 

func (dns *DNSResolver) Get() net.IP

Get returns the cached resolver, first updating the cached value if it's stale. If reloading fails, the previous value is used.

type GenerateConfigParams 

type GenerateConfigParams struct {
	LogFilename          string
	LogLevel             string
	ServerIPAddress      string
	WebServerPort        int
	EnableSSHAPIRequests bool
	TunnelProtocolPorts  map[string]int
	TrafficRulesFilename string
}

GenerateConfigParams specifies customizations to be applied to a generated server config.

type GeoIPData 

type GeoIPData struct {
	Country        string
	City           string
	ISP            string
	DiscoveryValue int
}

GeoIPData is GeoIP data for a client session. Individual client IP addresses are neither logged nor explicitly referenced during a session. The GeoIP country, city, and ISP corresponding to a client IP address are resolved and then logged along with usage stats. The DiscoveryValue is a special value derived from the client IP that's used to compartmentalize discoverable servers (see calculateDiscoveryValue for details).

func NewGeoIPData 

func NewGeoIPData() GeoIPData

NewGeoIPData returns a GeoIPData initialized with the expected GEOIP_UNKNOWN_VALUE values to be used when GeoIP lookup fails.

type GeoIPService 

type GeoIPService struct {
	// contains filtered or unexported fields
}

GeoIPService implements GeoIP lookup and session/GeoIP caching. Lookup is via a MaxMind database; the ReloadDatabase function supports hot reloading of MaxMind data while the server is running.

func NewGeoIPService 

func NewGeoIPService(
	databaseFilenames []string,
	discoveryValueHMACKey string) (*GeoIPService, error)

NewGeoIPService initializes a new GeoIPService.

func (*GeoIPService) GetSessionCache 

func (geoIP *GeoIPService) GetSessionCache(sessionID string) GeoIPData

GetSessionCache returns the cached GeoIPData for the specified session ID; a blank GeoIPData is returned if the session ID is not found in the cache.

func (*GeoIPService) Lookup 

func (geoIP *GeoIPService) Lookup(ipAddress string) GeoIPData

Lookup determines a GeoIPData for a given client IP address.

func (*GeoIPService) MarkSessionCacheToExpire 

func (geoIP *GeoIPService) MarkSessionCacheToExpire(sessionID string)

MarkSessionCacheToExpire initiates expiry for an existing session cache entry, if the session ID is found in the cache. Concurrency note: SetSessionCache and MarkSessionCacheToExpire should not be called concurrently for a single session ID.

func (*GeoIPService) Reloaders 

func (geoIP *GeoIPService) Reloaders() []common.Reloader

Reloaders gets the list of reloadable databases in use by the GeoIPService. This list is used to hot reload these databases.

func (*GeoIPService) SetSessionCache 

func (geoIP *GeoIPService) SetSessionCache(sessionID string, geoIPData GeoIPData)

SetSessionCache adds the sessionID/geoIPData pair to the session cache. This value will not expire; the caller must call MarkSessionCacheToExpire to initiate expiry. Calling SetSessionCache for an existing sessionID will replace the previous value and reset any expiry.

type HTTPSServer 

type HTTPSServer struct {
	http.Server
}

HTTPSServer is a wrapper around http.Server which adds the ServeTLS function.

func (*HTTPSServer) ServeTLS 

func (server *HTTPSServer) ServeTLS(listener net.Listener, config *tls.Config) error

ServeTLS is similar to http.Serve, but uses TLS.

The http package has both ListenAndServe and ListenAndServeTLS higher- level interfaces, but only Serve (not TLS) offers a lower-level interface that allows the caller to keep a refererence to the Listener, allowing for external shutdown. ListenAndServeTLS also requires the TLS cert and key to be in files and we avoid that here.

Note that the http.Server.TLSConfig field is ignored and the psiphon/common/tls.Config parameter is used intead.

tcpKeepAliveListener is used in http.ListenAndServeTLS but not exported, so we use a copy from https://golang.org/src/net/http/server.go.

type LogFields 

type LogFields logrus.Fields

LogFields is an alias for the field struct in the underlying logging package.

type MeekServer 

type MeekServer struct {
	// contains filtered or unexported fields
}

MeekServer implements the meek protocol, which tunnels TCP traffic (in the case of Psiphon, Obfusated SSH traffic) over HTTP. Meek may be fronted (through a CDN) or direct and may be HTTP or HTTPS.

Upstream traffic arrives in HTTP request bodies and downstream traffic is sent in response bodies. The sequence of traffic for a given flow is associated using a session ID that's set as a HTTP cookie for the client to submit with each request.

MeekServer hooks into TunnelServer via the net.Conn interface by transforming the HTTP payload traffic for a given session into net.Conn conforming Read()s and Write()s via the meekConn struct.

func NewMeekServer 

func NewMeekServer(
	support *SupportServices,
	listener net.Listener,
	useTLS, useObfuscatedSessionTickets bool,
	clientHandler func(clientConn net.Conn),
	stopBroadcast <-chan struct{}) (*MeekServer, error)

NewMeekServer initializes a new meek server.

func (*MeekServer) Run 

func (server *MeekServer) Run() error

Run runs the meek server; this function blocks while serving HTTP or HTTPS connections on the specified listener. This function also runs a goroutine which cleans up expired meek client sessions.

To stop the meek server, both Close() the listener and set the stopBroadcast signal specified in NewMeekServer.

func (*MeekServer) ServeHTTP 

func (server *MeekServer) ServeHTTP(responseWriter http.ResponseWriter, request *http.Request)

ServeHTTP handles meek client HTTP requests, where the request body contains upstream traffic and the response will contain downstream traffic.

type RateLimits 

type RateLimits struct {
	ReadUnthrottledBytes  *int64
	ReadBytesPerSecond    *int64
	WriteUnthrottledBytes *int64
	WriteBytesPerSecond   *int64
	CloseAfterExhausted   *bool
}

RateLimits is a clone of common.RateLimits with pointers to fields to enable distinguishing between zero values and omitted values in JSON serialized traffic rules. See common.RateLimits for field descriptions.

func (*RateLimits) CommonRateLimits 

func (rateLimits *RateLimits) CommonRateLimits() common.RateLimits

CommonRateLimits converts a RateLimits to a common.RateLimits.

type SupportServices 

type SupportServices struct {
	Config          *Config
	TrafficRulesSet *TrafficRulesSet
	OSLConfig       *osl.Config
	PsinetDatabase  *psinet.Database
	GeoIPService    *GeoIPService
	DNSResolver     *DNSResolver
	TunnelServer    *TunnelServer
}

SupportServices carries common and shared data components across different server components. SupportServices implements a hot reload of traffic rules, psinet database, and geo IP database components, which allows these data components to be refreshed without restarting the server process.

func NewSupportServices 

func NewSupportServices(config *Config) (*SupportServices, error)

NewSupportServices initializes a new SupportServices.

func (*SupportServices) Reload 

func (support *SupportServices) Reload()

Reload reinitializes traffic rules, psinet database, and geo IP database components. If any component fails to reload, an error is logged and Reload proceeds, using the previous state of the component.

type TrafficRules 

type TrafficRules struct {

	// RateLimits specifies data transfer rate limits for the
	// client traffic.
	RateLimits RateLimits

	// IdleTCPPortForwardTimeoutMilliseconds is the timeout period
	// after which idle (no bytes flowing in either direction)
	// client TCP port forwards are preemptively closed.
	// A value of 0 specifies no idle timeout. When omitted in
	// DefaultRules, DEFAULT_IDLE_TCP_PORT_FORWARD_TIMEOUT_MILLISECONDS
	// is used.
	IdleTCPPortForwardTimeoutMilliseconds *int

	// IdleUDPPortForwardTimeoutMilliseconds is the timeout period
	// after which idle (no bytes flowing in either direction)
	// client UDP port forwards are preemptively closed.
	// A value of 0 specifies no idle timeout. When omitted in
	// DefaultRules, DEFAULT_IDLE_UDP_PORT_FORWARD_TIMEOUT_MILLISECONDS
	// is used.
	IdleUDPPortForwardTimeoutMilliseconds *int

	// MaxTCPPortForwardCount is the maximum number of TCP port
	// forwards each client may have open concurrently.
	// A value of 0 specifies no maximum. When omitted in
	// DefaultRules, DEFAULT_MAX_TCP_PORT_FORWARD_COUNT is used.
	MaxTCPPortForwardCount *int

	// MaxUDPPortForwardCount is the maximum number of UDP port
	// forwards each client may have open concurrently.
	// A value of 0 specifies no maximum. When omitted in
	// DefaultRules, DEFAULT_MAX_UDP_PORT_FORWARD_COUNT is used.
	MaxUDPPortForwardCount *int

	// AllowTCPPorts specifies a whitelist of TCP ports that
	// are permitted for port forwarding. When set, only ports
	// in the list are accessible to clients.
	AllowTCPPorts []int

	// AllowUDPPorts specifies a whitelist of UDP ports that
	// are permitted for port forwarding. When set, only ports
	// in the list are accessible to clients.
	AllowUDPPorts []int

	// AllowSubnets specifies a list of IP address subnets for
	// which all TCP and UDP ports are allowed. This list is
	// consulted if a port is disallowed by the AllowTCPPorts
	// or AllowUDPPorts configuration. Each entry is a IP subnet
	// in CIDR notation.
	// Limitation: currently, AllowSubnets only matches port
	// forwards where the client sends an IP address. Domain
	// names aren not resolved before checking AllowSubnets.
	AllowSubnets []string
}

TrafficRules specify the limits placed on client traffic.

type TrafficRulesFilter 

type TrafficRulesFilter struct {

	// TunnelProtocols is a list of client tunnel protocols that must be
	// in use to match this filter. When omitted or empty, any protocol
	// matches.
	TunnelProtocols []string

	// Regions is a list of client GeoIP countries that the client must
	// reolve to to match this filter. When omitted or empty, any client
	// region matches.
	Regions []string

	// APIProtocol specifies whether the client must use the SSH
	// API protocol (when "ssh") or the web API protocol (when "web").
	// When omitted or blank, any API protocol matches.
	APIProtocol string

	// HandshakeParameters specifies handshake API parameter names and
	// a list of values, one of which must be specified to match this
	// filter. Only scalar string API parameters may be filtered.
	HandshakeParameters map[string][]string
}

TrafficRulesFilter defines a filter to match against client attributes.

type TrafficRulesSet 

type TrafficRulesSet struct {
	common.ReloadableFile

	// DefaultRules are the base values to use as defaults for all
	// clients.
	DefaultRules TrafficRules

	// FilteredTrafficRules is an ordered list of filter/rules pairs.
	// For each client, the first matching Filter in FilteredTrafficRules
	// determines the additional Rules that are selected and applied
	// on top of DefaultRules.
	FilteredRules []struct {
		Filter TrafficRulesFilter
		Rules  TrafficRules
	}
}

TrafficRulesSet represents the various traffic rules to apply to Psiphon client tunnels. The Reload function supports hot reloading of rules data while the server is running.

For a given client, the traffic rules are determined by starting with DefaultRules, then finding the first (if any) FilteredTrafficRules match and overriding the defaults with fields set in the selected FilteredTrafficRules.

func NewTrafficRulesSet 

func NewTrafficRulesSet(filename string) (*TrafficRulesSet, error)

NewTrafficRulesSet initializes a TrafficRulesSet with the rules data in the specified config file.

func (*TrafficRulesSet) GetTrafficRules 

func (set *TrafficRulesSet) GetTrafficRules(
	tunnelProtocol string, geoIPData GeoIPData, state handshakeState) TrafficRules

GetTrafficRules determines the traffic rules for a client based on its attributes. For the return value TrafficRules, all pointer and slice fields are initialized, so nil checks are not required. The caller must not modify the returned TrafficRules.

func (*TrafficRulesSet) Validate 

func (set *TrafficRulesSet) Validate() error

Validate checks for correct input formats in a TrafficRulesSet.

type TunnelServer 

type TunnelServer struct {
	// contains filtered or unexported fields
}

TunnelServer is the main server that accepts Psiphon client connections, via various obfuscation protocols, and provides port forwarding (TCP and UDP) services to the Psiphon client. At its core, TunnelServer is an SSH server. SSH is the base protocol that provides port forward multiplexing, and transport security. Layered on top of SSH, optionally, is Obfuscated SSH and meek protocols, which provide further circumvention capabilities.

func NewTunnelServer 

func NewTunnelServer(
	support *SupportServices,
	shutdownBroadcast <-chan struct{}) (*TunnelServer, error)

NewTunnelServer initializes a new tunnel server.

func (*TunnelServer) GetEstablishTunnels 

func (server *TunnelServer) GetEstablishTunnels() bool

GetEstablishTunnels returns whether new tunnels may be established or not.

func (*TunnelServer) GetLoadStats 

func (server *TunnelServer) GetLoadStats() map[string]map[string]int64

GetLoadStats returns load stats for the tunnel server. The stats are broken down by protocol ("SSH", "OSSH", etc.) and type. Types of stats include current connected client count, total number of current port forwards.

func (*TunnelServer) ResetAllClientOSLConfigs 

func (server *TunnelServer) ResetAllClientOSLConfigs()

ResetAllClientOSLConfigs resets all established client OSL state to use the latest OSL config. Any existing OSL state is lost, including partial progress towards SLOKs.

func (*TunnelServer) ResetAllClientTrafficRules 

func (server *TunnelServer) ResetAllClientTrafficRules()

ResetAllClientTrafficRules resets all established client traffic rules to use the latest config and client properties. Any existing traffic rule state is lost, including throttling state.

func (*TunnelServer) Run 

func (server *TunnelServer) Run() error

Run runs the tunnel server; this function blocks while running a selection of listeners that handle connection using various obfuscation protocols.

Run listens on each designated tunnel port and spawns new goroutines to handle each client connection. It halts when shutdownBroadcast is signaled. A list of active clients is maintained, and when halting all clients are cleanly shutdown.

Each client goroutine handles its own obfuscation (optional), SSH handshake, SSH authentication, and then looping on client new channel requests. "direct-tcpip" channels, dynamic port fowards, are supported. When the UDPInterceptUdpgwServerAddress config parameter is configured, UDP port forwards over a TCP stream, following the udpgw protocol, are handled.

A new goroutine is spawned to handle each port forward for each client. Each port forward tracks its bytes transferred. Overall per-client stats for connection duration, GeoIP, number of port forwards, and bytes transferred are tracked and logged when the client shuts down.

Note: client handler goroutines may still be shutting down after Run() returns. See comment in sshClient.stop(). TODO: fully synchronized shutdown.

func (*TunnelServer) SetClientHandshakeState 

func (server *TunnelServer) SetClientHandshakeState(
	sessionID string, state handshakeState) error

SetClientHandshakeState sets the handshake state -- that it completed and what paramaters were passed -- in sshClient. This state is used for allowing port forwards and for future traffic rule selection. SetClientHandshakeState also triggers an immediate traffic rule re-selection, as the rules selected upon tunnel establishment may no longer apply now that handshake values are set.

func (*TunnelServer) SetEstablishTunnels 

func (server *TunnelServer) SetEstablishTunnels(establish bool)

SetEstablishTunnels sets whether new tunnels may be established or not. When not establishing, incoming connections are immediately closed.

type X5C 

type X5C []string

Source Files

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Directories

Path Synopsis
Package psiphon/server/psinet implements psinet database services.
 Package psiphon/server/psinet implements psinet database services.

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