TransportUtil

java.lang.Object

net.i2p.router.transport.TransportUtil

public abstract class TransportUtilextends Object

Utility class providing common transport operations and configurations.

This class contains static methods and constants used throughout the transport system for address validation, port management, IPv6 configuration, and network utility functions.

Key Features:

IPv4 and IPv6 address validation and parsing
Port range validation and assignment
IPv6 configuration options for transports
Firewall and NAT detection utilities
Geographic IP filtering and validation
Transport-specific constants and defaults

IPv6 Support:

Configuration options for NTCP and SSU transports
Address format validation for IPv6
Port assignment and range checking
Compatibility helpers for mixed IPv4/IPv6 environments

Network Utilities:

Port assignment strategies (random vs. configured)
Firewall detection and bypass methods
Transport protocol constants and defaults
Address type detection and validation

Nested Class Summary
Nested Classes
Modifier and Type
Class
Description
static enum
TransportUtil.IPv6Config
IPv6 configuration options for transports.
Field Summary
Modifier and Type
Field
Description
private static final Map<String, TransportUtil.IPv6Config>
BY_NAME
The IPv6 modes, by config value.
static final TransportUtil.IPv6Config
DEFAULT_IPV6_CONFIG
DEFAULT_IPV6_CONFIG.
private static final int
MAX_RANDOM_PORT
Highest port chosen by the random picker.
private static final int
MIN_RANDOM_PORT
8998 is monotone, and 31000 is the wrapper outbound, so let's stay between those Was 9111, increase to skip Tor browser at 9050.
static final String
NTCP_IPV6_CONFIG
NTCP_IPV6_CONFIG.
static final String
PROP_IPV4_FIREWALLED
PROP_IPV4_FIREWALLED.
static final String
PROP_IPV6_FIREWALLED
If true, this router believes its IPv6 address is firewalled.
private static final String
PROP_MAX_PORT_SFX
Suffix of a transport's maximum-port property.
private static final String
PROP_MIN_PORT_SFX
Suffix of a transport's minimum-port property.
private static final String
PROP_PORT_PFX
Config keys for the data port range and minimums.
static final String
SSU_IPV6_CONFIG
SSU_IPV6_CONFIG.
private static final Pattern
YGGDRASIL_PATTERN
Matches an address on the Yggdrasil network.
Constructor Summary
Constructors
Constructor
Description
TransportUtil()
Constructor for subclasses; the operations in this base class are static.
Method Summary
All Methods
Modifier and Type
Method
Description
static TransportUtil.IPv6Config
getIPv6Config(String cfg)
The IPv6 config for the given config string.
static TransportUtil.IPv6Config
getIPv6Config(RouterContext ctx, String transportStyle)
The IPv6 config for the given transport style.
static AddressType
getType(byte[] ip)
Address type of the given IP address.
static AddressType
getType(String host)
Address type of the given host string.
static AddressType
getType(RouterAddress addr)
Address type of the given RouterAddress.
static boolean
hasUsableTransportAddress(RouterInfo ri)
Does this RouterInfo carry at least one address we could still send to?
static boolean
isIPv4Firewalled(RouterContext ctx)
This returns true if the force-firewalled setting is configured, false otherwise.
static boolean
isIPv6(RouterAddress addr)
Addresses without a host (i.e.
static boolean
isIPv6Firewalled(RouterContext ctx)
This returns true if the force-firewalled setting is configured, false otherwise.
static boolean
isPubliclyRoutable(byte[] addr, boolean allowIPv6)
Whether the address is publicly routable, optionally allowing IPv6.
static boolean
isPubliclyRoutable(byte[] addr, boolean allowIPv4, boolean allowIPv6)
Ref: RFC 5735.
static boolean
isUsableRouterAddress(RouterAddress ra)
Is the RouterAddress usable for tunnel building?
static boolean
isValidPort(int port)
Is this a valid port for us or a remote router?
static boolean
isYggdrasil(RouterAddress addr)
Whether the address is an in-network Yggdrasil address.
static void
logInvalidPort(Log log, String transportStyle, int port)
Logs an error for an invalid port.
static int
selectRandomPort(RouterContext ctx, String transportStyle)
Pick a random port between the configured boundaries.
Methods inherited from class Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- NTCP_IPV6_CONFIG
  public static final String NTCP_IPV6_CONFIG
  NTCP_IPV6_CONFIG.
  See Also:
  Constant Field Values
- SSU_IPV6_CONFIG
  public static final String SSU_IPV6_CONFIG
  SSU_IPV6_CONFIG.
  See Also:
  Constant Field Values
- PROP_IPV4_FIREWALLED
  public static final String PROP_IPV4_FIREWALLED
  PROP_IPV4_FIREWALLED.
  See Also:
  Constant Field Values
- PROP_IPV6_FIREWALLED
  public static final String PROP_IPV6_FIREWALLED
  If true, this router believes its IPv6 address is firewalled.
  See Also:
  Constant Field Values
- PROP_PORT_PFX
  private static final String PROP_PORT_PFX
  Config keys for the data port range and minimums.
  See Also:
  Constant Field Values
- PROP_MIN_PORT_SFX
  private static final String PROP_MIN_PORT_SFX
  Suffix of a transport's minimum-port property.
  See Also:
  Constant Field Values
- PROP_MAX_PORT_SFX
  private static final String PROP_MAX_PORT_SFX
  Suffix of a transport's maximum-port property.
  See Also:
  Constant Field Values
- MIN_RANDOM_PORT
  private static final int MIN_RANDOM_PORT
  8998 is monotone, and 31000 is the wrapper outbound, so let's stay between those Was 9111, increase to skip Tor browser at 9050.
  See Also:
  Constant Field Values
- MAX_RANDOM_PORT
  private static final int MAX_RANDOM_PORT
  Highest port chosen by the random picker.
  See Also:
  Constant Field Values
- YGGDRASIL_PATTERN
  private static final Pattern YGGDRASIL_PATTERN
  Matches an address on the Yggdrasil network.
- BY_NAME
  private static final Map<String, TransportUtil.IPv6Config> BY_NAME
  The IPv6 modes, by config value.
- DEFAULT_IPV6_CONFIG
  public static final TransportUtil.IPv6Config DEFAULT_IPV6_CONFIG
  DEFAULT_IPV6_CONFIG.
Constructor Details
- TransportUtil
  public TransportUtil()
  Constructor for subclasses; the operations in this base class are static.
Method Details
- getIPv6Config
  public static TransportUtil.IPv6Config getIPv6Config(RouterContext ctx, String transportStyle)
  The IPv6 config for the given transport style.
  Parameters:
  ctx - the router context
  transportStyle - the transport to read the config for, NTCP or SSU
  Returns:
  the IPv6 config
- getIPv6Config
  public static TransportUtil.IPv6Config getIPv6Config(String cfg)
  The IPv6 config for the given config string.
  Parameters:
  cfg - the config string to look up
  Returns:
  the IPv6 config
- isIPv4Firewalled
  public static boolean isIPv4Firewalled(RouterContext ctx)
  This returns true if the force-firewalled setting is configured, false otherwise.
  Parameters:
  ctx - the router context
  Returns:
  whether i pv4 firewalled
- isIPv6Firewalled
  public static boolean isIPv6Firewalled(RouterContext ctx)
  This returns true if the force-firewalled setting is configured, false otherwise.
  Parameters:
  ctx - the router context
  Returns:
  whether IPv6 firewalled
- isIPv6
  public static boolean isIPv6(RouterAddress addr)
  Addresses without a host (i.e. w/introducers) are assumed to be IPv4 unless a '6' cap is present.
  Parameters:
  addr - non-null
  Returns:
  whether IPv6
- isUsableRouterAddress
  public static boolean isUsableRouterAddress(RouterAddress ra)
  Is the RouterAddress usable for tunnel building?
  SSU requires protocol v2 plus a valid IP/port or an introduction; SSU2 requires a valid IP/port or an introduction; NTCP/NTCP2 require a valid IP/port.
  Lives here rather than in TunnelPeerSelector because both the tunnel selectors and ProfileOrganizer need it, and the latter must not reach into tunnel.pool — that package already depends on peermanager, so the reverse edge would close a cycle.
  Pure decision: no context access, safe for unit tests.
  Parameters:
  ra - the router address to check (non-null)
  Returns:
  true if the address is usable
- hasUsableTransportAddress
  public static boolean hasUsableTransportAddress(RouterInfo ri)
  Does this RouterInfo carry at least one address we could still send to?
  A peer whose addresses have all expired or become unusable cannot be selected for a build and cannot be pre-connected to, so admitting it to a selection tier only produces a candidate that is guaranteed to fail. Gate promotion on this.
  Pure decision: takes the RouterInfo rather than consulting the netdb, so callers holding an entry do not pay for a second lookup.
  Parameters:
  ri - the router info to check (non-null)
  Returns:
  true if at least one address is usable
- isYggdrasil
  public static boolean isYggdrasil(RouterAddress addr)
  Whether the address is an in-network Yggdrasil address.
  Parameters:
  addr - the address to classify
  Returns:
  true if the host string matches the Yggdrasil overlay pattern
- getType
  public static AddressType getType(RouterAddress addr)
  Address type of the given RouterAddress.
  Parameters:
  addr - the address to classify
  Returns:
  null if unknown
- getType
  public static AddressType getType(String host)
  Address type of the given host string.
  Parameters:
  host - the host string to classify
  Returns:
  null if unknown
- getType
  public static AddressType getType(byte[] ip)
  Address type of the given IP address.
  Parameters:
  ip - the raw 4 or 16 byte address to classify
  Returns:
  null if unknown
- isPubliclyRoutable
  public static boolean isPubliclyRoutable(byte[] addr, boolean allowIPv6)
  Whether the address is publicly routable, optionally allowing IPv6.
  Parameters:
  addr - non-null
  allowIPv6 - true to treat global IPv6 addresses as routable
  Returns:
  whether publicly routable
- isPubliclyRoutable
  public static boolean isPubliclyRoutable(byte[] addr, boolean allowIPv4, boolean allowIPv6)
  Ref: RFC 5735.
  Parameters:
  addr - non-null
  allowIPv4 - true to treat global IPv4 addresses as routable
  allowIPv6 - true to treat global IPv6 addresses as routable
  Returns:
  whether publicly routable
- isValidPort
  public static boolean isValidPort(int port)
  Is this a valid port for us or a remote router?
  ref: http://i2p-projekt.i2p/en/docs/ports ref: https://cs.chromium.org/chromium/src/net/base/port_util.cc
  Parameters:
  port - the port to test
  Returns:
  whether valid port
- logInvalidPort
  public static void logInvalidPort(Log log, String transportStyle, int port)
  Logs an error for an invalid port.
  Parameters:
  log - the logger to write to
  transportStyle - the transport that was configured
  port - the rejected port
- selectRandomPort
  public static int selectRandomPort(RouterContext ctx, String transportStyle)
  Pick a random port between the configured boundaries.
  Parameters:
  ctx - the router context
  transportStyle - the transport the port is for, NTCP or SSU
  Returns:
  the port chosen

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class Object

Field Details

NTCP_IPV6_CONFIG

SSU_IPV6_CONFIG

PROP_IPV4_FIREWALLED

PROP_IPV6_FIREWALLED

PROP_PORT_PFX

PROP_MIN_PORT_SFX

PROP_MAX_PORT_SFX

MIN_RANDOM_PORT

MAX_RANDOM_PORT

YGGDRASIL_PATTERN

BY_NAME

DEFAULT_IPV6_CONFIG

Constructor Details

Method Details

getIPv6Config

getIPv6Config

isIPv4Firewalled

isIPv6Firewalled

isIPv6

isUsableRouterAddress

hasUsableTransportAddress

isYggdrasil

getType

getType

getType

isPubliclyRoutable

isPubliclyRoutable

isValidPort

logInvalidPort

selectRandomPort