java.lang.Object
net.i2p.addressbook.HostChecker
public class HostCheckerextends Object
Ping tester for address book entries. Tests I2P destinations for reachability and stores results.

  • Field Details

    • PING_TIMESTAMP_COMPARATOR

      private static final Comparator<Map.Entry<String, HostChecker.PingResult>> PING_TIMESTAMP_COMPARATOR
      Sorts ping results by timestamp, oldest first.

    • _context

      private final I2PAppContext _context
      The app context.

    • _log

      private final Log _log
      Logger for the host checks.

    • _namingService

      private final NamingService _namingService
      Naming service holding the hosts to check.

    • _scheduler

      private final ScheduledExecutorService _scheduler
      Executor running the ping cycles.

    • _pingResults

      private final Map<String, HostChecker.PingResult> _pingResults
      Latest ping result by host name.

    • _hostCategories

      private Map<String,String> _hostCategories
      Category assigned to each host.

    • _running

      private final AtomicBoolean _running
      True while the checker is running.

    • _categoriesDownloaded

      private final AtomicBoolean _categoriesDownloaded
      Whether the category list has been downloaded.

    • _categoriesDownloadSuccessful

      private final AtomicBoolean _categoriesDownloadSuccessful
      Whether the last category download succeeded.

    • _cycleInProgress

      private final AtomicBoolean _cycleInProgress
      True while a ping cycle is running.

    • _hostsCheckFile

      private final File _hostsCheckFile
      File storing the ping results.

    • _categoriesFile

      private final File _categoriesFile
      File storing the host categories.

    • _blacklistFile

      private final File _blacklistFile
      File listing hosts never to ping.

    • _configFile

      private final File _configFile
      File holding the checker's settings.

    • _pingSemaphore

      private final HostChecker.DynamicSemaphore _pingSemaphore
      Limits how many hosts ping at once.

    • _sharedPingSocketManager

      private volatile I2PSocketManager _sharedPingSocketManager
      Shared socket manager for the pings.

    • _blacklistedHosts

      private Set<String> _blacklistedHosts
      Hosts excluded from checking.

    • _blacklistLastModified

      private volatile long _blacklistLastModified
      Modification time of the blacklist file.

    • _configLastModified

      private volatile long _configLastModified
      Modification time of the config file.

    • _pingTaskFuture

      private volatile ScheduledFuture<?> _pingTaskFuture
      The scheduled ping task, kept for cancellation.

    • _categoryRetryCount

      private int _categoryRetryCount
      Category download attempts so far.

    • _DATE_FORMAT

      private static final ThreadLocal<DateFormat> _DATE_FORMAT
      Per-thread date format for the result display.

    • DEFAULT_PING_INTERVAL

      private static final long DEFAULT_PING_INTERVAL
      Default interval between ping cycles, four hours.
      See Also:

    • DEFAULT_PING_TIMEOUT

      private static final long DEFAULT_PING_TIMEOUT
      Default timeout for one ping is 60 seconds.
      See Also:

    • DEFAULT_MAX_CONCURRENT

      private static final int DEFAULT_MAX_CONCURRENT
      Default hosts pinged at once.
      See Also:

    • MAX_SHARED_PING_TUNNELS

      private static final int MAX_SHARED_PING_TUNNELS
      Cap on outbound tunnels for the shared ping session; pings are a bonus check, each tunnel costs a network build.
      See Also:

    • KEEP_UP_MS

      private static final long KEEP_UP_MS
      A host confirmed up within this window stays up when its LeaseSet can't be fetched this cycle.
      See Also:

    • PROP_PING_INTERVAL

      private static final String PROP_PING_INTERVAL
      Config key for the ping cycle interval.
      See Also:

    • PROP_MAX_CONCURRENT

      private static final String PROP_MAX_CONCURRENT
      Config key for the concurrent ping limit.
      See Also:

    • STARTUP_DELAY_MS

      private static final long STARTUP_DELAY_MS
      Wait after startup before the first ping cycle.
      See Also:

    • CATEGORY_DOWNLOAD_DELAY_MS

      private static final long CATEGORY_DOWNLOAD_DELAY_MS
      Wait before downloading the category list.
      See Also:

    • CATEGORY_CONNECT_TIMEOUT

      private static final int CATEGORY_CONNECT_TIMEOUT
      Connect timeout for the category download.
      See Also:

    • CATEGORY_INACTIVITY_TIMEOUT

      private static final int CATEGORY_INACTIVITY_TIMEOUT
      Inactivity timeout for the category download.
      See Also:

    • CATEGORY_TOTAL_TIMEOUT

      private static final int CATEGORY_TOTAL_TIMEOUT
      Total timeout for the category download.
      See Also:

    • CATEGORY_RETRY_INTERVAL

      private static final long CATEGORY_RETRY_INTERVAL
      Wait before retrying a failed category download.
      See Also:

    • COMMA_SPLIT

      private static final Pattern COMMA_SPLIT
      Splits a category line on commas.

    • PING_TASK_TIMEOUT

      private static final long PING_TASK_TIMEOUT
      Limit on one ping cycle before it is cancelled.
      See Also:

    • _pingInterval

      private volatile long _pingInterval
      Ping cycle interval in effect right now.

    • _pingTimeout

      private long _pingTimeout
      Timeout for one ping, in effect right now.

    • _maxConcurrent

      private volatile int _maxConcurrent
      Hosts pinged at once, in effect right now.

    • _useLeaseSetCheck

      private boolean _useLeaseSetCheck
      Whether a lease set reply counts as a successful ping.

  • Constructor Details

    • HostChecker

      public HostChecker()
      Construct a HostChecker that uses the default naming service This works with the blockfile format (hostsdb.blockfile).

    • HostChecker

      public HostChecker(NamingService namingService)
      Construct a HostChecker for given naming service.
      Parameters:
      namingService - naming service to test entries from

  • Method Details

    • loadConfiguration

      private void loadConfiguration()
      Load configuration from addressbook/config.txt file Reads pingInterval and maxConcurrent properties if present.

    • parseConfigFile

      private void parseConfigFile()
      Parse addressbook/config.txt and update the ping interval and concurrency fields. Invalid values leave the current settings untouched.

    • refreshConfiguration

      private void refreshConfiguration()
      Re-read addressbook/config.txt when it changed and apply the new values live. A new interval reschedules the cycle task (next cycle only); a new concurrency limit takes effect in the in-progress cycle immediately.

    • reschedulePingTask

      private void reschedulePingTask()
      Cancel the current cycle schedule and restart it with the current interval. A cycle already in progress keeps running; the single-flight guard skips the next scheduled run if it would overlap.

    • start

      public void start()
      Start periodic ping testing.

    • stop

      public void stop()
      Stop periodic ping testing.

    • runCheckNow

      public void runCheckNow()
      Run a host check cycle immediately, unless one is already in progress. The periodic cycle schedule is unaffected.

    • isScanRunning

      public boolean isScanRunning()
      Whether a host check cycle is currently in progress.
      Returns:
      true if a cycle is running

    • performLeaseSetLookup

      private HostChecker.PingResult performLeaseSetLookup(String hostname, Destination destination)
      Perform LeaseSet lookup as the first check Any cached LeaseSet marks the host up directly — even an expired one proves the host exists. Only when no LeaseSet is cached locally do we trigger a fresh remote fetch. If the lookup fails, responseTime is set to -1 and we skip ping/eephead.
      Parameters:
      hostname - hostname to test
      destination - destination for the hostname
      Returns:
      PingResult; responseTime preserves the existing value on success, -1 if the lookup failed

    • testDestination

      public HostChecker.PingResult testDestination(String hostname)
      Test a single destination immediately If LeaseSet lookup succeeds, we don't overwrite the result with failed ping/eephead.
      Parameters:
      hostname - hostname to test
      Returns:
      the result recorded for this host, blacklisted hosts never pinged

    • lookupLeaseSetRemotely

      private HostChecker.PingResult lookupLeaseSetRemotely(String hostname, Hash destHash, long startTime, long existingResponseTime)
      Perform remote LeaseSet lookup via floodfill network and record the result. A found LeaseSet marks the host up, keeping the previously known response time; a failed lookup retains a recent up-result or records a down-result with response time -1.
      Parameters:
      hostname - the host being checked, used as the result cache key
      destHash - hash of the destination whose LeaseSet is fetched
      startTime - test start time in ms, used as the result timestamp
      existingResponseTime - last known response time in ms, or -1 if never measured
      Returns:
      the recorded PingResult: up if a LeaseSet was found or a recent up-result retained, down otherwise

    • retainRecentUp

      private HostChecker.PingResult retainRecentUp(String hostname, long now)
      If the host was confirmed up within the last 24h, keep it up when the current cycle can't fetch its LeaseSet - an unverifiable host is not a confirmed-down host.
      Parameters:
      hostname - the host to check
      now - current time for the age comparison and result timestamp
      Returns:
      a fresh up-result retaining the last response time and LeaseSet types, or null when there is nothing to retain

    • removeFromClientTracking

      private void removeFromClientTracking(Hash destHash)
      Remove LeaseSet from client refresh tracking after HostChecker is done with it. This prevents unnecessary refreshes of LeaseSets that were only looked up for ping checking.
      Parameters:
      destHash - the destination to untrack; a null value, or a context that is not a router context, makes this a no-op

    • createPingSessionOptions

      private static Properties createPingSessionOptions(String nickname, int inboundQuantity, int outboundQuantity)
      Build the I2CP options for a HostChecker ping session. Inbound tunnels only carry tiny pong replies; inboundQuantity of 1 is enough, 2 adds redundancy if a tunnel drops. The outbound quantity is caller-controlled since it scales with ping concurrency.
      Parameters:
      nickname - nickname for the inbound and outbound pools
      inboundQuantity - number of inbound tunnels to build
      outboundQuantity - number of outbound tunnels to build
      Returns:
      a fresh Properties object holding the I2CP session options, including the fixed localhost connection and LS3 encryption settings

    • pingDestination

      private HostChecker.PingResult pingDestination(String hostname, Destination destination)
      Ping destination using single tunnel and I2Ping-style retry handling Falls back to EepHead HTTP HEAD request if ping fails, accepts leaseSetTypes parameter.
      Parameters:
      hostname - the host to ping, used as the result cache key
      destination - the destination to ping
      Returns:
      the PingResult from the ping, or from the EepHead fallback if the ping failed

    • pingDestination

      private HostChecker.PingResult pingDestination(String hostname, Destination destination, String leaseSetTypes)
      Ping destination using single tunnel and I2Ping-style retry handling Falls back to EepHead HTTP HEAD request if ping fails, accepts leaseSetTypes parameter.
      Parameters:
      hostname - the host to ping, used as the result cache key
      destination - the destination to ping
      leaseSetTypes - LeaseSet types string to carry into the result, or null for "[]"
      Returns:
      the PingResult from the ping, or from the EepHead fallback if the ping failed

    • pingDestination

      private HostChecker.PingResult pingDestination(String hostname, Destination destination, String leaseSetTypes, boolean saveResult)
      Ping destination using single tunnel and I2Ping-style retry handling Falls back to EepHead HTTP HEAD request if ping fails, accepts leaseSetTypes parameter.
      Parameters:
      hostname - the host to ping, used as the result cache key
      destination - the destination to ping
      leaseSetTypes - LeaseSet types string to carry into the result, or null for "[]"
      saveResult - whether to save the result to _pingResults (false when LeaseSet lookup already succeeded)
      Returns:
      the PingResult from the ping, or from the EepHead fallback when the ping failed and the result was saved

    • fallbackToEepHead

      private HostChecker.PingResult fallbackToEepHead(String hostname, long startTime)
      Fallback method to use EepHead for HTTP HEAD request testing Marks site as up if any response is received.
      Parameters:
      hostname - the host to probe, used as the result cache key
      startTime - test start time in ms, used as the result timestamp
      Returns:
      the PingResult: up with the HEAD round-trip time if any response was received, down with response time -1 otherwise

    • fallbackToEepHead

      private HostChecker.PingResult fallbackToEepHead(String hostname, long startTime, String leaseSetTypes, boolean saveResult)
      Fallback method to use EepHead for HTTP HEAD request testing Marks site as up if any response is received.
      Parameters:
      hostname - the host to probe, used as the result cache key
      startTime - test start time in ms, used as the result timestamp
      leaseSetTypes - LeaseSet types string to carry into the result, or null for "[]"
      saveResult - whether to save the result to _pingResults (false when LeaseSet lookup already succeeded)
      Returns:
      the PingResult: up with the HEAD round-trip time if any response was received, down with response time -1 otherwise

    • getPingResult

      public HostChecker.PingResult getPingResult(String hostname)
      Get ping result for a hostname.
      Parameters:
      hostname - the hostname whose stored ping result is wanted
      Returns:
      ping result, or null if no test has been performed

    • getAllPingResults

      public Map<String, HostChecker.PingResult> getAllPingResults()
      Get all ping results.
      Returns:
      map of hostname to ping result

    • setUseLeaseSetCheck

      public void setUseLeaseSetCheck(boolean useLeaseSetCheck)
      Set whether to use LeaseSet checking.
      Parameters:
      useLeaseSetCheck - true to use LeaseSet lookup first

    • getUseLeaseSetCheck

      public boolean getUseLeaseSetCheck()
      Get whether to use LeaseSet checking.
      Returns:
      true if LeaseSet checking is enabled

    • isRunning

      public boolean isRunning()
      Check if ping tester is running.
      Returns:
      true if running

    • loadPingResults

      private void loadPingResults()
      Load ping results from hosts_check.txt file.

    • savePingResults

      private void savePingResults()
      Save ping results to hosts_check.txt file.

    • writeCleanHostsCheckFile

      private void writeCleanHostsCheckFile(List<String> validLines) throws IOException
      Write cleaned hosts_check.txt file with only valid entries.
      Parameters:
      validLines - the cleaned lines to write, in order, headers included
      Throws:
      IOException - if the hosts_check.txt file cannot be opened or written

    • getDestination

      private Destination getDestination(String hostname)
      Get destination for a hostname from naming service.
      Parameters:
      hostname - the host name to look up
      Returns:
      the destination, or null if the naming service has no entry

    • getAllHostnames

      private Set<String> getAllHostnames()
      Get all hostnames from the naming service.
      Returns:
      the all hostnames

    • cleanupStaleHosts

      private void cleanupStaleHosts()
      Remove hosts from _pingResults that are no longer in the address book This prevents stale entries from accumulating in hosts_check.txt.

    • downloadCategories

      private void downloadCategories()
      Download categories file from notbob.i2p Falls back to existing stale categories.txt if download fails.

    • writeCleanCategoriesFile

      private void writeCleanCategoriesFile(List<String> validLines) throws IOException
      Write cleaned categories.txt file with only valid entries (no empty lines).
      Parameters:
      validLines - the cleaned lines to write, in order, headers included
      Throws:
      IOException - if the categories.txt file cannot be opened or written

    • loadCategories

      private void loadCategories()
      Load categories from categories.txt file.

    • getCategory

      public String getCategory(String hostname)
      Get category for a hostname.
      Parameters:
      hostname - the host to look up, as spelled in the categories file
      Returns:
      the category name, or null if the host is uncategorized

    • getCategoryDescription

      public String getCategoryDescription(String category)
      Get description for a category.
      Parameters:
      category - the category name
      Returns:
      the category description, or the category itself if unknown

    • createPingResult

      private HostChecker.PingResult createPingResult(boolean reachable, long timestamp, long responseTime, String hostname)
      Helper method to create PingResult with category.
      Parameters:
      reachable - true if the host was found reachable
      timestamp - time the result was recorded, in Java ms
      responseTime - round-trip time in ms, or -1 when not measured
      hostname - used to look up the category from _hostCategories
      Returns:
      PingResult with category (or null if unknown) and no leaseSetTypes

    • createPingResult

      private HostChecker.PingResult createPingResult(boolean reachable, long timestamp, long responseTime, String hostname, String leaseSetTypes)
      Helper method to create PingResult with category and leaseSetTypes. An existing non-empty leaseSetTypes string is kept when the new lookup brings nothing or the same value, so a transient failure cannot erase known-good types.
      Parameters:
      reachable - true if the host was found reachable
      timestamp - time the result was recorded, in Java ms
      responseTime - round-trip time in ms, or -1 when not measured
      hostname - used to look up the category from _hostCategories
      leaseSetTypes - LeaseSet types string like "[6,4]", or null or "[]" to keep any previously recorded value
      Returns:
      a new PingResult with the category (or null if unknown) and the effective leaseSetTypes

    • getAllCategories

      public Map<String,String> getAllCategories()
      Get all host categories.
      Returns:
      the all categories

    • scheduleCategoryRetries

      private void scheduleCategoryRetries()
      Schedule periodic category download retries.

    • attemptCategoryDownload

      private boolean attemptCategoryDownload()
      Attempt to download categories file Returns true if successful, false otherwise.
      Returns:
      true if the fetch produced at least one data line and the categories file was rewritten with it, false on any fetch, validation, or write failure

    • refreshCategories

      private void refreshCategories()
      Refresh categories at the start of each HostChecker cycle Attempts to download fresh categories from notbob.i2p, falls back to existing file.

    • updateHostsWithCategories

      private void updateHostsWithCategories()
      Update hosts_check.txt with category information after successful category download.

    • loadBlacklist

      private void loadBlacklist()
      Reads the blacklisted hosts from the file.

    • isHostBlacklisted

      private boolean isHostBlacklisted(String hostname)
      Checks whether a host is excluded from checking.
      Parameters:
      hostname - the host to check
      Returns:
      true if the host is blacklisted

    • formatLeaseSetTypes

      private static String formatLeaseSetTypes(LeaseSet leaseSet)
      Format LeaseSet encryption types as a string like "[0]" or "[4,0]".
      Parameters:
      leaseSet - the LeaseSet to inspect, v1 or v2; a null value, or one whose encryption keys cannot be read, yields "[]"
      Returns:
      the encryption type codes joined without spaces inside square brackets, or "[]" when no types were found

    • _t

      private static String _t(String s)
      Looks up a localized string in the message bundle.
      Parameters:
      s - the message key in the addressbook bundle
      Returns:
      the translated string, or s itself if no translation exists

    • main

      public static void main(String[] args) throws Exception
      Test method.
      Parameters:
      args - command line arguments, unused
      Throws:
      Exception - if the test run cannot be started or stopped