config.c

/* Copyright (c) 2001 Matej Pfajfar.
 * Copyright (c) 2001-2004, Roger Dingledine.
 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
 * Copyright (c) 2007-2010, The Tor Project, Inc. */
/* See LICENSE for licensing information */

/**
 * \file config.c
 * \brief Code to parse and interpret configuration files.
 **/

#define CONFIG_PRIVATE

#include "or.h"
#include "circuitbuild.h"
#include "circuitlist.h"
#include "config.h"
#include "connection.h"
#include "connection_edge.h"
#include "connection_or.h"
#include "control.h"
#include "cpuworker.h"
#include "dirserv.h"
#include "dirvote.h"
#include "dns.h"
#include "geoip.h"
#include "hibernate.h"
#include "main.h"
#include "networkstatus.h"
#include "policies.h"
#include "relay.h"
#include "rendclient.h"
#include "rendservice.h"
#include "rephist.h"
#include "router.h"
#include "routerlist.h"
#ifdef MS_WINDOWS
#include <shlobj.h>
#endif

/** Enumeration of types which option values can take */
typedef enum config_type_t {
  CONFIG_TYPE_STRING = 0,   /**< An arbitrary string. */
  CONFIG_TYPE_FILENAME,     /**< A filename: some prefixes get expanded. */
  CONFIG_TYPE_UINT,         /**< A non-negative integer less than MAX_INT */
  CONFIG_TYPE_INTERVAL,     /**< A number of seconds, with optional units*/
  CONFIG_TYPE_MSEC_INTERVAL,/**< A number of milliseconds, with optional
                              * units */
  CONFIG_TYPE_MEMUNIT,      /**< A number of bytes, with optional units*/
  CONFIG_TYPE_DOUBLE,       /**< A floating-point value */
  CONFIG_TYPE_BOOL,         /**< A boolean value, expressed as 0 or 1. */
  CONFIG_TYPE_ISOTIME,      /**< An ISO-formatted time relative to GMT. */
  CONFIG_TYPE_CSV,          /**< A list of strings, separated by commas and
                              * optional whitespace. */
  CONFIG_TYPE_LINELIST,     /**< Uninterpreted config lines */
  CONFIG_TYPE_LINELIST_S,   /**< Uninterpreted, context-sensitive config lines,
                             * mixed with other keywords. */
  CONFIG_TYPE_LINELIST_V,   /**< Catch-all "virtual" option to summarize
                             * context-sensitive config lines when fetching.
                             */
  CONFIG_TYPE_ROUTERSET,    /**< A list of router names, addrs, and fps,
                             * parsed into a routerset_t. */
  CONFIG_TYPE_OBSOLETE,     /**< Obsolete (ignored) option. */
} config_type_t;

/** An abbreviation for a configuration option allowed on the command line. */
typedef struct config_abbrev_t {
  const char *abbreviated;
  const char *full;
  int commandline_only;
  int warn;
} config_abbrev_t;

/* Handy macro for declaring "In the config file or on the command line,
 * you can abbreviate <b>tok</b>s as <b>tok</b>". */
#define PLURAL(tok) { #tok, #tok "s", 0, 0 }

/** A list of abbreviations and aliases to map command-line options, obsolete
 * option names, or alternative option names, to their current values. */
static config_abbrev_t _option_abbrevs[] = {
  PLURAL(ExitNode),
  PLURAL(EntryNode),
  PLURAL(ExcludeNode),
  PLURAL(FirewallPort),
  PLURAL(LongLivedPort),
  PLURAL(HiddenServiceNode),
  PLURAL(HiddenServiceExcludeNode),
  PLURAL(NumCPU),
  PLURAL(RendNode),
  PLURAL(RendExcludeNode),
  PLURAL(StrictEntryNode),
  PLURAL(StrictExitNode),
  PLURAL(StrictNode),
  { "l", "Log", 1, 0},
  { "AllowUnverifiedNodes", "AllowInvalidNodes", 0, 0},
  { "AutomapHostSuffixes", "AutomapHostsSuffixes", 0, 0},
  { "AutomapHostOnResolve", "AutomapHostsOnResolve", 0, 0},
  { "BandwidthRateBytes", "BandwidthRate", 0, 0},
  { "BandwidthBurstBytes", "BandwidthBurst", 0, 0},
  { "DirFetchPostPeriod", "StatusFetchPeriod", 0, 0},
  { "MaxConn", "ConnLimit", 0, 1},
  { "ORBindAddress", "ORListenAddress", 0, 0},
  { "DirBindAddress", "DirListenAddress", 0, 0},
  { "SocksBindAddress", "SocksListenAddress", 0, 0},
  { "UseHelperNodes", "UseEntryGuards", 0, 0},
  { "NumHelperNodes", "NumEntryGuards", 0, 0},
  { "UseEntryNodes", "UseEntryGuards", 0, 0},
  { "NumEntryNodes", "NumEntryGuards", 0, 0},
  { "ResolvConf", "ServerDNSResolvConfFile", 0, 1},
  { "SearchDomains", "ServerDNSSearchDomains", 0, 1},
  { "ServerDNSAllowBrokenResolvConf", "ServerDNSAllowBrokenConfig", 0, 0},
  { "PreferTunnelledDirConns", "PreferTunneledDirConns", 0, 0},
  { "BridgeAuthoritativeDirectory", "BridgeAuthoritativeDir", 0, 0},
  { "HashedControlPassword", "__HashedControlSessionPassword", 1, 0},
  { "StrictEntryNodes", "StrictNodes", 0, 1},
  { "StrictExitNodes", "StrictNodes", 0, 1},
  { NULL, NULL, 0, 0},
};

/** A list of state-file "abbreviations," for compatibility. */
static config_abbrev_t _state_abbrevs[] = {
  { "AccountingBytesReadInterval", "AccountingBytesReadInInterval", 0, 0 },
  { "HelperNode", "EntryGuard", 0, 0 },
  { "HelperNodeDownSince", "EntryGuardDownSince", 0, 0 },
  { "HelperNodeUnlistedSince", "EntryGuardUnlistedSince", 0, 0 },
  { "EntryNode", "EntryGuard", 0, 0 },
  { "EntryNodeDownSince", "EntryGuardDownSince", 0, 0 },
  { "EntryNodeUnlistedSince", "EntryGuardUnlistedSince", 0, 0 },
  { NULL, NULL, 0, 0},
};
#undef PLURAL

/** A variable allowed in the configuration file or on the command line. */
typedef struct config_var_t {
  const char *name; /**< The full keyword (case insensitive). */
  config_type_t type; /**< How to interpret the type and turn it into a
                       * value. */
  off_t var_offset; /**< Offset of the corresponding member of or_options_t. */
  const char *initvalue; /**< String (or null) describing initial value. */
} config_var_t;

/** An entry for config_vars: "The option <b>name</b> has type
 * CONFIG_TYPE_<b>conftype</b>, and corresponds to
 * or_options_t.<b>member</b>"
 */
#define VAR(name,conftype,member,initvalue)                             \
  { name, CONFIG_TYPE_ ## conftype, STRUCT_OFFSET(or_options_t, member), \
      initvalue }
/** As VAR, but the option name and member name are the same. */
#define V(member,conftype,initvalue)                                    \
  VAR(#member, conftype, member, initvalue)
/** An entry for config_vars: "The option <b>name</b> is obsolete." */
#define OBSOLETE(name) { name, CONFIG_TYPE_OBSOLETE, 0, NULL }

/** Array of configuration options.  Until we disallow nonstandard
 * abbreviations, order is significant, since the first matching option will
 * be chosen first.
 */
static config_var_t _option_vars[] = {
  OBSOLETE("AccountingMaxKB"),
  V(AccountingMax,               MEMUNIT,  "0 bytes"),
  V(AccountingStart,             STRING,   NULL),
  V(Address,                     STRING,   NULL),
  V(AllowDotExit,                BOOL,     "0"),
  V(AllowInvalidNodes,           CSV,      "middle,rendezvous"),
  V(AllowNonRFC953Hostnames,     BOOL,     "0"),
  V(AllowSingleHopCircuits,      BOOL,     "0"),
  V(AllowSingleHopExits,         BOOL,     "0"),
  V(AlternateBridgeAuthority,    LINELIST, NULL),
  V(AlternateDirAuthority,       LINELIST, NULL),
  V(AlternateHSAuthority,        LINELIST, NULL),
  V(AssumeReachable,             BOOL,     "0"),
  V(AuthDirBadDir,               LINELIST, NULL),
  V(AuthDirBadExit,              LINELIST, NULL),
  V(AuthDirInvalid,              LINELIST, NULL),
  V(AuthDirReject,               LINELIST, NULL),
  V(AuthDirRejectUnlisted,       BOOL,     "0"),
  V(AuthDirListBadDirs,          BOOL,     "0"),
  V(AuthDirListBadExits,         BOOL,     "0"),
  V(AuthDirMaxServersPerAddr,    UINT,     "2"),
  V(AuthDirMaxServersPerAuthAddr,UINT,     "5"),
  VAR("AuthoritativeDirectory",  BOOL, AuthoritativeDir,    "0"),
  V(AutomapHostsOnResolve,       BOOL,     "0"),
  V(AutomapHostsSuffixes,        CSV,      ".onion,.exit"),
  V(AvoidDiskWrites,             BOOL,     "0"),
  V(BandwidthBurst,              MEMUNIT,  "10 MB"),
  V(BandwidthRate,               MEMUNIT,  "5 MB"),
  V(BridgeAuthoritativeDir,      BOOL,     "0"),
  VAR("Bridge",                  LINELIST, Bridges,    NULL),
  V(BridgePassword,              STRING,   NULL),
  V(BridgeRecordUsageByCountry,  BOOL,     "1"),
  V(BridgeRelay,                 BOOL,     "0"),
  V(CellStatistics,              BOOL,     "0"),
  V(LearnCircuitBuildTimeout,    BOOL,     "1"),
  V(CircuitBuildTimeout,         INTERVAL, "0"),
  V(CircuitIdleTimeout,          INTERVAL, "1 hour"),
  V(CircuitStreamTimeout,        INTERVAL, "0"),
  V(CircuitPriorityHalflife,     DOUBLE,  "-100.0"), /*negative:'Use default'*/
  V(ClientDNSRejectInternalAddresses, BOOL,"1"),
  V(ClientOnly,                  BOOL,     "0"),
  V(ConsensusParams,             STRING,   NULL),
  V(ConnLimit,                   UINT,     "1000"),
  V(ConnStatistics,              BOOL,     "0"),
  V(ConstrainedSockets,          BOOL,     "0"),
  V(ConstrainedSockSize,         MEMUNIT,  "8192"),
  V(ContactInfo,                 STRING,   NULL),
  V(ControlListenAddress,        LINELIST, NULL),
  V(ControlPort,                 UINT,     "0"),
  V(ControlSocket,               LINELIST, NULL),
  V(CookieAuthentication,        BOOL,     "0"),
  V(CookieAuthFileGroupReadable, BOOL,     "0"),
  V(CookieAuthFile,              STRING,   NULL),
  V(DataDirectory,               FILENAME, NULL),
  OBSOLETE("DebugLogFile"),
  V(DirAllowPrivateAddresses,    BOOL,     NULL),
  V(TestingAuthDirTimeToLearnReachability, INTERVAL, "30 minutes"),
  V(DirListenAddress,            LINELIST, NULL),
  OBSOLETE("DirFetchPeriod"),
  V(DirPolicy,                   LINELIST, NULL),
  V(DirPort,                     UINT,     "0"),
  V(DirPortFrontPage,            FILENAME, NULL),
  OBSOLETE("DirPostPeriod"),
  OBSOLETE("DirRecordUsageByCountry"),
  OBSOLETE("DirRecordUsageGranularity"),
  OBSOLETE("DirRecordUsageRetainIPs"),
  OBSOLETE("DirRecordUsageSaveInterval"),
  V(DirReqStatistics,            BOOL,     "0"),
  VAR("DirServer",               LINELIST, DirServers, NULL),
  V(DisableAllSwap,              BOOL,     "0"),
  V(DisableIOCP,                 BOOL,     "1"),
  V(DNSPort,                     UINT,     "0"),
  V(DNSListenAddress,            LINELIST, NULL),
  V(DownloadExtraInfo,           BOOL,     "0"),
  V(EnforceDistinctSubnets,      BOOL,     "1"),
  V(EntryNodes,                  ROUTERSET,   NULL),
  V(EntryStatistics,             BOOL,     "0"),
  V(TestingEstimatedDescriptorPropagationTime, INTERVAL, "10 minutes"),
  V(ExcludeNodes,                ROUTERSET, NULL),
  V(ExcludeExitNodes,            ROUTERSET, NULL),
  V(ExcludeSingleHopRelays,      BOOL,     "1"),
  V(ExitNodes,                   ROUTERSET, NULL),
  V(ExitPolicy,                  LINELIST, NULL),
  V(ExitPolicyRejectPrivate,     BOOL,     "1"),
  V(ExitPortStatistics,          BOOL,     "0"),
  V(ExtraInfoStatistics,         BOOL,     "0"),

#if defined (WINCE)
  V(FallbackNetworkstatusFile,   FILENAME, "fallback-consensus"),
#else
  V(FallbackNetworkstatusFile,   FILENAME,
    SHARE_DATADIR PATH_SEPARATOR "tor" PATH_SEPARATOR "fallback-consensus"),
#endif
  V(FascistFirewall,             BOOL,     "0"),
  V(FirewallPorts,               CSV,      ""),
  V(FastFirstHopPK,              BOOL,     "1"),
  V(FetchDirInfoEarly,           BOOL,     "0"),
  V(FetchDirInfoExtraEarly,      BOOL,     "0"),
  V(FetchServerDescriptors,      BOOL,     "1"),
  V(FetchHidServDescriptors,     BOOL,     "1"),
  V(FetchUselessDescriptors,     BOOL,     "0"),
#ifdef WIN32
  V(GeoIPFile,                   FILENAME, "<default>"),
#else
  V(GeoIPFile,                   FILENAME,
    SHARE_DATADIR PATH_SEPARATOR "tor" PATH_SEPARATOR "geoip"),
#endif
  OBSOLETE("Group"),
  V(HardwareAccel,               BOOL,     "0"),
  V(AccelName,                   STRING,   NULL),
  V(AccelDir,                    FILENAME, NULL),
  V(HashedControlPassword,       LINELIST, NULL),
  V(HidServDirectoryV2,          BOOL,     "1"),
  VAR("HiddenServiceDir",    LINELIST_S, RendConfigLines,    NULL),
  OBSOLETE("HiddenServiceExcludeNodes"),
  OBSOLETE("HiddenServiceNodes"),
  VAR("HiddenServiceOptions",LINELIST_V, RendConfigLines,    NULL),
  VAR("HiddenServicePort",   LINELIST_S, RendConfigLines,    NULL),
  VAR("HiddenServiceVersion",LINELIST_S, RendConfigLines,    NULL),
  VAR("HiddenServiceAuthorizeClient",LINELIST_S,RendConfigLines, NULL),
  V(HidServAuth,                 LINELIST, NULL),
  V(HSAuthoritativeDir,          BOOL,     "0"),
  OBSOLETE("HSAuthorityRecordStats"),
  V(HTTPProxy,                   STRING,   NULL),
  V(HTTPProxyAuthenticator,      STRING,   NULL),
  V(HTTPSProxy,                  STRING,   NULL),
  V(HTTPSProxyAuthenticator,     STRING,   NULL),
  V(Socks4Proxy,                 STRING,   NULL),
  V(Socks5Proxy,                 STRING,   NULL),
  V(Socks5ProxyUsername,         STRING,   NULL),
  V(Socks5ProxyPassword,         STRING,   NULL),
  OBSOLETE("IgnoreVersion"),
  V(KeepalivePeriod,             INTERVAL, "5 minutes"),
  VAR("Log",                     LINELIST, Logs,             NULL),
  OBSOLETE("LinkPadding"),
  OBSOLETE("LogLevel"),
  OBSOLETE("LogFile"),
  V(LogTimeGranularity,          MSEC_INTERVAL, "1 second"),
  V(LongLivedPorts,              CSV,
                         "21,22,706,1863,5050,5190,5222,5223,6667,6697,8300"),
  VAR("MapAddress",              LINELIST, AddressMap,           NULL),
  V(MaxAdvertisedBandwidth,      MEMUNIT,  "1 GB"),
  V(MaxCircuitDirtiness,         INTERVAL, "10 minutes"),
  V(MaxOnionsPending,            UINT,     "100"),
  OBSOLETE("MonthlyAccountingStart"),
  V(MyFamily,                    STRING,   NULL),
  V(NewCircuitPeriod,            INTERVAL, "30 seconds"),
  VAR("NamingAuthoritativeDirectory",BOOL, NamingAuthoritativeDir, "0"),
  V(NATDListenAddress,           LINELIST, NULL),
  V(NATDPort,                    UINT,     "0"),
  V(Nickname,                    STRING,   NULL),
  V(WarnUnsafeSocks,              BOOL,     "1"),
  OBSOLETE("NoPublish"),
  VAR("NodeFamily",              LINELIST, NodeFamilies,         NULL),
  V(NumCPUs,                     UINT,     "0"),
  V(NumEntryGuards,              UINT,     "3"),
  V(ORListenAddress,             LINELIST, NULL),
  V(ORPort,                      UINT,     "0"),
  V(OutboundBindAddress,         STRING,   NULL),
  OBSOLETE("PathlenCoinWeight"),
  V(PerConnBWBurst,              MEMUNIT,  "0"),
  V(PerConnBWRate,               MEMUNIT,  "0"),
  V(PidFile,                     STRING,   NULL),
  V(TestingTorNetwork,           BOOL,     "0"),
  V(PortForwarding,              BOOL,     "0"),
  V(PortForwardingHelper,        FILENAME, "tor-fw-helper"),
  V(PreferTunneledDirConns,      BOOL,     "1"),
  V(ProtocolWarnings,            BOOL,     "0"),
  V(PublishServerDescriptor,     CSV,      "1"),
  V(PublishHidServDescriptors,   BOOL,     "1"),
  V(ReachableAddresses,          LINELIST, NULL),
  V(ReachableDirAddresses,       LINELIST, NULL),
  V(ReachableORAddresses,        LINELIST, NULL),
  V(RecommendedVersions,         LINELIST, NULL),
  V(RecommendedClientVersions,   LINELIST, NULL),
  V(RecommendedServerVersions,   LINELIST, NULL),
  OBSOLETE("RedirectExit"),
  V(RefuseUnknownExits,          STRING,   "auto"),
  V(RejectPlaintextPorts,        CSV,      ""),
  V(RelayBandwidthBurst,         MEMUNIT,  "0"),
  V(RelayBandwidthRate,          MEMUNIT,  "0"),
  OBSOLETE("RendExcludeNodes"),
  OBSOLETE("RendNodes"),
  V(RendPostPeriod,              INTERVAL, "1 hour"),
  V(RephistTrackTime,            INTERVAL, "24 hours"),
  OBSOLETE("RouterFile"),
  V(RunAsDaemon,                 BOOL,     "0"),
//  V(RunTesting,                  BOOL,     "0"),
  OBSOLETE("RunTesting"), // currently unused
  V(SafeLogging,                 STRING,   "1"),
  V(SafeSocks,                   BOOL,     "0"),
  V(ServerDNSAllowBrokenConfig,  BOOL,     "1"),
  V(ServerDNSAllowNonRFC953Hostnames, BOOL,"0"),
  V(ServerDNSDetectHijacking,    BOOL,     "1"),
  V(ServerDNSRandomizeCase,      BOOL,     "1"),
  V(ServerDNSResolvConfFile,     STRING,   NULL),
  V(ServerDNSSearchDomains,      BOOL,     "0"),
  V(ServerDNSTestAddresses,      CSV,
      "www.google.com,www.mit.edu,www.yahoo.com,www.slashdot.org"),
  V(ShutdownWaitLength,          INTERVAL, "30 seconds"),
  V(SocksListenAddress,          LINELIST, NULL),
  V(SocksPolicy,                 LINELIST, NULL),
  V(SocksPort,                   UINT,     "9050"),
  V(SocksTimeout,                INTERVAL, "2 minutes"),
  OBSOLETE("StatusFetchPeriod"),
  V(StrictNodes,                 BOOL,     "0"),
  OBSOLETE("SysLog"),
  V(TestSocks,                   BOOL,     "0"),
  OBSOLETE("TestVia"),
  V(TrackHostExits,              CSV,      NULL),
  V(TrackHostExitsExpire,        INTERVAL, "30 minutes"),
  OBSOLETE("TrafficShaping"),
  V(TransListenAddress,          LINELIST, NULL),
  V(TransPort,                   UINT,     "0"),
  V(TunnelDirConns,              BOOL,     "1"),
  V(UpdateBridgesFromAuthority,  BOOL,     "0"),
  V(UseBridges,                  BOOL,     "0"),
  V(UseEntryGuards,              BOOL,     "1"),
  V(User,                        STRING,   NULL),
  VAR("V1AuthoritativeDirectory",BOOL, V1AuthoritativeDir,   "0"),
  VAR("V2AuthoritativeDirectory",BOOL, V2AuthoritativeDir,   "0"),
  VAR("V3AuthoritativeDirectory",BOOL, V3AuthoritativeDir,   "0"),
  V(TestingV3AuthInitialVotingInterval, INTERVAL, "30 minutes"),
  V(TestingV3AuthInitialVoteDelay, INTERVAL, "5 minutes"),
  V(TestingV3AuthInitialDistDelay, INTERVAL, "5 minutes"),
  V(V3AuthVotingInterval,        INTERVAL, "1 hour"),
  V(V3AuthVoteDelay,             INTERVAL, "5 minutes"),
  V(V3AuthDistDelay,             INTERVAL, "5 minutes"),
  V(V3AuthNIntervalsValid,       UINT,     "3"),
  V(V3AuthUseLegacyKey,          BOOL,     "0"),
  V(V3BandwidthsFile,            FILENAME, NULL),
  VAR("VersioningAuthoritativeDirectory",BOOL,VersioningAuthoritativeDir, "0"),
  V(VirtualAddrNetwork,          STRING,   "127.192.0.0/10"),
  V(WarnPlaintextPorts,          CSV,      "23,109,110,143"),
  V(_UseFilteringSSLBufferevents, BOOL,    "0"),
  VAR("__ReloadTorrcOnSIGHUP",   BOOL,  ReloadTorrcOnSIGHUP,      "1"),
  VAR("__AllDirActionsPrivate",  BOOL,  AllDirActionsPrivate,     "0"),
  VAR("__DisablePredictedCircuits",BOOL,DisablePredictedCircuits, "0"),
  VAR("__LeaveStreamsUnattached",BOOL,  LeaveStreamsUnattached,   "0"),
  VAR("__HashedControlSessionPassword", LINELIST, HashedControlSessionPassword,
      NULL),
  V(MinUptimeHidServDirectoryV2, INTERVAL, "24 hours"),

  { NULL, CONFIG_TYPE_OBSOLETE, 0, NULL }
};

/** Override default values with these if the user sets the TestingTorNetwork
 * option. */
static config_var_t testing_tor_network_defaults[] = {
  V(ServerDNSAllowBrokenConfig,  BOOL,  "1"),
  V(DirAllowPrivateAddresses,    BOOL,     "1"),
  V(EnforceDistinctSubnets,      BOOL,     "0"),
  V(AssumeReachable,             BOOL,     "1"),
  V(AuthDirMaxServersPerAddr,    UINT,     "0"),
  V(AuthDirMaxServersPerAuthAddr,UINT,     "0"),
  V(ClientDNSRejectInternalAddresses, BOOL,"0"),
  V(ExitPolicyRejectPrivate,     BOOL,     "0"),
  V(V3AuthVotingInterval,        INTERVAL, "5 minutes"),
  V(V3AuthVoteDelay,             INTERVAL, "20 seconds"),
  V(V3AuthDistDelay,             INTERVAL, "20 seconds"),
  V(TestingV3AuthInitialVotingInterval, INTERVAL, "5 minutes"),
  V(TestingV3AuthInitialVoteDelay, INTERVAL, "20 seconds"),
  V(TestingV3AuthInitialDistDelay, INTERVAL, "20 seconds"),
  V(TestingAuthDirTimeToLearnReachability, INTERVAL, "0 minutes"),
  V(TestingEstimatedDescriptorPropagationTime, INTERVAL, "0 minutes"),
  V(MinUptimeHidServDirectoryV2, INTERVAL, "0 minutes"),
  { NULL, CONFIG_TYPE_OBSOLETE, 0, NULL }
};
#undef VAR

#define VAR(name,conftype,member,initvalue)                             \
  { name, CONFIG_TYPE_ ## conftype, STRUCT_OFFSET(or_state_t, member),  \
      initvalue }

/** Array of "state" variables saved to the ~/.tor/state file. */
static config_var_t _state_vars[] = {
  V(AccountingBytesReadInInterval,    MEMUNIT,  NULL),
  V(AccountingBytesWrittenInInterval, MEMUNIT,  NULL),
  V(AccountingExpectedUsage,          MEMUNIT,  NULL),
  V(AccountingIntervalStart,          ISOTIME,  NULL),
  V(AccountingSecondsActive,          INTERVAL, NULL),
  V(AccountingSecondsToReachSoftLimit,INTERVAL, NULL),
  V(AccountingSoftLimitHitAt,         ISOTIME,  NULL),
  V(AccountingBytesAtSoftLimit,       MEMUNIT,  NULL),

  VAR("EntryGuard",              LINELIST_S,  EntryGuards,             NULL),
  VAR("EntryGuardDownSince",     LINELIST_S,  EntryGuards,             NULL),
  VAR("EntryGuardUnlistedSince", LINELIST_S,  EntryGuards,             NULL),
  VAR("EntryGuardAddedBy",       LINELIST_S,  EntryGuards,             NULL),
  V(EntryGuards,                 LINELIST_V,  NULL),

  V(BWHistoryReadEnds,                ISOTIME,  NULL),
  V(BWHistoryReadInterval,            UINT,     "900"),
  V(BWHistoryReadValues,              CSV,      ""),
  V(BWHistoryWriteEnds,               ISOTIME,  NULL),
  V(BWHistoryWriteInterval,           UINT,     "900"),
  V(BWHistoryWriteValues,             CSV,      ""),
  V(BWHistoryDirReadEnds,             ISOTIME,  NULL),
  V(BWHistoryDirReadInterval,         UINT,     "900"),
  V(BWHistoryDirReadValues,           CSV,      ""),
  V(BWHistoryDirWriteEnds,            ISOTIME,  NULL),
  V(BWHistoryDirWriteInterval,        UINT,     "900"),
  V(BWHistoryDirWriteValues,          CSV,      ""),

  V(TorVersion,                       STRING,   NULL),

  V(LastRotatedOnionKey,              ISOTIME,  NULL),
  V(LastWritten,                      ISOTIME,  NULL),

  V(TotalBuildTimes,                  UINT,     NULL),
  V(CircuitBuildAbandonedCount,       UINT,     "0"),
  VAR("CircuitBuildTimeBin",          LINELIST_S, BuildtimeHistogram, NULL),
  VAR("BuildtimeHistogram",           LINELIST_V, BuildtimeHistogram, NULL),

  { NULL, CONFIG_TYPE_OBSOLETE, 0, NULL }
};

#undef VAR
#undef V
#undef OBSOLETE

/** Represents an English description of a configuration variable; used when
 * generating configuration file comments. */
typedef struct config_var_description_t {
  const char *name;
  const char *description;
} config_var_description_t;

/** Type of a callback to validate whether a given configuration is
 * well-formed and consistent. See options_trial_assign() for documentation
 * of arguments. */
typedef int (*validate_fn_t)(void*,void*,int,char**);

/** Information on the keys, value types, key-to-struct-member mappings,
 * variable descriptions, validation functions, and abbreviations for a
 * configuration or storage format. */
typedef struct {
  size_t size; /**< Size of the struct that everything gets parsed into. */
  uint32_t magic; /**< Required 'magic value' to make sure we have a struct
                   * of the right type. */
  off_t magic_offset; /**< Offset of the magic value within the struct. */
  config_abbrev_t *abbrevs; /**< List of abbreviations that we expand when
                             * parsing this format. */
  config_var_t *vars; /**< List of variables we recognize, their default
                       * values, and where we stick them in the structure. */
  validate_fn_t validate_fn; /**< Function to validate config. */
  /** If present, extra is a LINELIST variable for unrecognized
   * lines.  Otherwise, unrecognized lines are an error. */
  config_var_t *extra;
} config_format_t;

/** Macro: assert that <b>cfg</b> has the right magic field for format
 * <b>fmt</b>. */
#define CHECK(fmt, cfg) STMT_BEGIN                                      \
    tor_assert(fmt && cfg);                                             \
    tor_assert((fmt)->magic ==                                          \
               *(uint32_t*)STRUCT_VAR_P(cfg,fmt->magic_offset));        \
  STMT_END

#ifdef MS_WINDOWS
static char *get_windows_conf_root(void);
#endif
static void config_line_append(config_line_t **lst,
                               const char *key, const char *val);
static void option_clear(config_format_t *fmt, or_options_t *options,
                         config_var_t *var);
static void option_reset(config_format_t *fmt, or_options_t *options,
                         config_var_t *var, int use_defaults);
static void config_free(config_format_t *fmt, void *options);
static int config_lines_eq(config_line_t *a, config_line_t *b);
static int option_is_same(config_format_t *fmt,
                          or_options_t *o1, or_options_t *o2,
                          const char *name);
static or_options_t *options_dup(config_format_t *fmt, or_options_t *old);
static int options_validate(or_options_t *old_options, or_options_t *options,
                            int from_setconf, char **msg);
static int options_act_reversible(or_options_t *old_options, char **msg);
static int options_act(or_options_t *old_options);
static int options_transition_allowed(or_options_t *old, or_options_t *new,
                                      char **msg);
static int options_transition_affects_workers(or_options_t *old_options,
                                              or_options_t *new_options);
static int options_transition_affects_descriptor(or_options_t *old_options,
                                                 or_options_t *new_options);
static int check_nickname_list(const char *lst, const char *name, char **msg);
static void config_register_addressmaps(or_options_t *options);

static int parse_bridge_line(const char *line, int validate_only);
static int parse_dir_server_line(const char *line,
                                 authority_type_t required_type,
                                 int validate_only);
static int validate_data_directory(or_options_t *options);
static int write_configuration_file(const char *fname, or_options_t *options);
static config_line_t *get_assigned_option(config_format_t *fmt,
                                          void *options, const char *key,
                                          int escape_val);
static void config_init(config_format_t *fmt, void *options);
static int or_state_validate(or_state_t *old_options, or_state_t *options,
                             int from_setconf, char **msg);
static int or_state_load(void);
static int options_init_logs(or_options_t *options, int validate_only);

static int is_listening_on_low_port(uint16_t port_option,
                                    const config_line_t *listen_options);

static uint64_t config_parse_memunit(const char *s, int *ok);
static int config_parse_msec_interval(const char *s, int *ok);
static int config_parse_interval(const char *s, int *ok);
static void init_libevent(const or_options_t *options);
static int opt_streq(const char *s1, const char *s2);

/** Magic value for or_options_t. */
#define OR_OPTIONS_MAGIC 9090909

/** Configuration format for or_options_t. */
static config_format_t options_format = {
  sizeof(or_options_t),
  OR_OPTIONS_MAGIC,
  STRUCT_OFFSET(or_options_t, _magic),
  _option_abbrevs,
  _option_vars,
  (validate_fn_t)options_validate,
  NULL
};

/** Magic value for or_state_t. */
#define OR_STATE_MAGIC 0x57A73f57

/** "Extra" variable in the state that receives lines we can't parse. This
 * lets us preserve options from versions of Tor newer than us. */
static config_var_t state_extra_var = {
  "__extra", CONFIG_TYPE_LINELIST, STRUCT_OFFSET(or_state_t, ExtraLines), NULL
};

/** Configuration format for or_state_t. */
static config_format_t state_format = {
  sizeof(or_state_t),
  OR_STATE_MAGIC,
  STRUCT_OFFSET(or_state_t, _magic),
  _state_abbrevs,
  _state_vars,
  (validate_fn_t)or_state_validate,
  &state_extra_var,
};

/*
 * Functions to read and write the global options pointer.
 */

/** Command-line and config-file options. */
static or_options_t *global_options = NULL;
/** Name of most recently read torrc file. */
static char *torrc_fname = NULL;
/** Persistent serialized state. */
static or_state_t *global_state = NULL;
/** Configuration Options set by command line. */
static config_line_t *global_cmdline_options = NULL;
/** Contents of most recently read DirPortFrontPage file. */
static char *global_dirfrontpagecontents = NULL;

/** Return the contents of our frontpage string, or NULL if not configured. */
const char *
get_dirportfrontpage(void)
{
  return global_dirfrontpagecontents;
}

/** Allocate an empty configuration object of a given format type. */
static void *
config_alloc(config_format_t *fmt)
{
  void *opts = tor_malloc_zero(fmt->size);
  *(uint32_t*)STRUCT_VAR_P(opts, fmt->magic_offset) = fmt->magic;
  CHECK(fmt, opts);
  return opts;
}

/** Return the currently configured options. */
or_options_t *
get_options(void)
{
  tor_assert(global_options);
  return global_options;
}

/** Change the current global options to contain <b>new_val</b> instead of
 * their current value; take action based on the new value; free the old value
 * as necessary.  Returns 0 on success, -1 on failure.
 */
int
set_options(or_options_t *new_val, char **msg)
{
  or_options_t *old_options = global_options;
  global_options = new_val;
  /* Note that we pass the *old* options below, for comparison. It
   * pulls the new options directly out of global_options. */
  if (options_act_reversible(old_options, msg)<0) {
    tor_assert(*msg);
    global_options = old_options;
    return -1;
  }
  if (options_act(old_options) < 0) { /* acting on the options failed. die. */
    log_err(LD_BUG,
            "Acting on config options left us in a broken state. Dying.");
    exit(1);
  }

  config_free(&options_format, old_options);

  return 0;
}

extern const char tor_git_revision[]; /* from tor_main.c */

/** The version of this Tor process, as parsed. */
static char *_version = NULL;

/** Return the current Tor version. */
const char *
get_version(void)
{
  if (_version == NULL) {
    if (strlen(tor_git_revision)) {
      size_t len = strlen(VERSION)+strlen(tor_git_revision)+16;
      _version = tor_malloc(len);
      tor_snprintf(_version, len, "%s (git-%s)", VERSION, tor_git_revision);
    } else {
      _version = tor_strdup(VERSION);
    }
  }
  return _version;
}

/** Release additional memory allocated in options
 */
static void
or_options_free(or_options_t *options)
{
  if (!options)
    return;

  routerset_free(options->_ExcludeExitNodesUnion);
  if (options->NodeFamilySets) {
    SMARTLIST_FOREACH(options->NodeFamilySets, routerset_t *,
                      rs, routerset_free(rs));
    smartlist_free(options->NodeFamilySets);
  }
  config_free(&options_format, options);
}

/** Release all memory and resources held by global configuration structures.
 */
void
config_free_all(void)
{
  or_options_free(global_options);
  global_options = NULL;

  config_free(&state_format, global_state);
  global_state = NULL;

  config_free_lines(global_cmdline_options);
  global_cmdline_options = NULL;

  tor_free(torrc_fname);
  tor_free(_version);
  tor_free(global_dirfrontpagecontents);
}

/** Make <b>address</b> -- a piece of information related to our operation as
 * a client -- safe to log according to the settings in options->SafeLogging,
 * and return it.
 *
 * (We return "[scrubbed]" if SafeLogging is "1", and address otherwise.)
 */
const char *
safe_str_client(const char *address)
{
  tor_assert(address);
  if (get_options()->_SafeLogging == SAFELOG_SCRUB_ALL)
    return "[scrubbed]";
  else
    return address;
}

/** Make <b>address</b> -- a piece of information of unspecified sensitivity
 * -- safe to log according to the settings in options->SafeLogging, and
 * return it.
 *
 * (We return "[scrubbed]" if SafeLogging is anything besides "0", and address
 * otherwise.)
 */
const char *
safe_str(const char *address)
{
  tor_assert(address);
  if (get_options()->_SafeLogging != SAFELOG_SCRUB_NONE)
    return "[scrubbed]";
  else
    return address;
}

/** Equivalent to escaped(safe_str_client(address)).  See reentrancy note on
 * escaped(): don't use this outside the main thread, or twice in the same
 * log statement. */
const char *
escaped_safe_str_client(const char *address)
{
  if (get_options()->_SafeLogging == SAFELOG_SCRUB_ALL)
    return "[scrubbed]";
  else
    return escaped(address);
}

/** Equivalent to escaped(safe_str(address)).  See reentrancy note on
 * escaped(): don't use this outside the main thread, or twice in the same
 * log statement. */
const char *
escaped_safe_str(const char *address)
{
  if (get_options()->_SafeLogging != SAFELOG_SCRUB_NONE)
    return "[scrubbed]";
  else
    return escaped(address);
}

/** Add the default directory authorities directly into the trusted dir list,
 * but only add them insofar as they share bits with <b>type</b>. */
static void
add_default_trusted_dir_authorities(authority_type_t type)
{
  int i;
  const char *dirservers[] = {
    "moria1 orport=9101 no-v2 "
      "v3ident=D586D18309DED4CD6D57C18FDB97EFA96D330566 "
      "128.31.0.39:9131 9695 DFC3 5FFE B861 329B 9F1A B04C 4639 7020 CE31",
    "tor26 v1 orport=443 v3ident=14C131DFC5C6F93646BE72FA1401C02A8DF2E8B4 "