tor/src/or/config.c

/* Copyright 2001 Matej Pfajfar.
 * Copyright 2001-2004 Roger Dingledine.
 * Copyright 2004 Roger Dingledine, Nick Mathewson. */
/* See LICENSE for licensing information */
/* $Id$ */
const char config_c_id[] = "$Id$";

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

#include "or.h"
#ifdef MS_WINDOWS
#include <shlobj.h>
#endif
#include "../common/aes.h"

/** Enumeration of types which option values can take */
typedef enum config_type_t {
  CONFIG_TYPE_STRING = 0,   /**< An arbitrary string. */
  CONFIG_TYPE_UINT,         /**< A non-negative integer less than MAX_INT */
  CONFIG_TYPE_INTERVAL,     /**< A number of seconds, 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_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_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;
} 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 }

/* A list of command-line abbreviations. */
static config_abbrev_t config_abbrevs[] = {
  PLURAL(ExitNode),
  PLURAL(EntryNode),
  PLURAL(ExcludeNode),
  PLURAL(FirewallPort),
  PLURAL(LongLivedPort),
  PLURAL(HiddenServiceNode),
  PLURAL(HiddenServiceExcludeNode),
  PLURAL(RendNode),
  PLURAL(RendExcludeNode),
  PLURAL(StrictEntryNode),
  PLURAL(StrictExitNode),
  { "l", "Log", 1},
  { "BandwidthRateBytes", "BandwidthRate", 0},
  { "BandwidthBurstBytes", "BandwidthBurst", 0},
  { "DirFetchPostPeriod", "StatusFetchPeriod", 0},
  { NULL, NULL , 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;

/** Return the offset of <b>member</b> within the type <b>tp</b>, in bytes */
#define STRUCT_OFFSET(tp, member) ((off_t) (((char*)&((tp*)0)->member)-(char*)0))
/** 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 }
/** 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 config_vars[] = {
  VAR("Address",             STRING,   Address,              NULL),
  VAR("AccountingStart",     STRING,   AccountingStart,      NULL),
  VAR("AllowUnverifiedNodes",CSV,      AllowUnverifiedNodes, "middle,rendezvous"),
  VAR("AuthoritativeDirectory",BOOL,   AuthoritativeDir,     "0"),
  VAR("BandwidthRate",       MEMUNIT,  BandwidthRate,        "1 MB"),
  VAR("BandwidthBurst",      MEMUNIT,  BandwidthBurst,       "5 MB"),
  VAR("ClientOnly",          BOOL,     ClientOnly,           "0"),
  VAR("ContactInfo",         STRING,   ContactInfo,          NULL),
  VAR("ControlPort",         UINT,     ControlPort,          "0"),
  VAR("CookieAuthentication",BOOL,     CookieAuthentication, "0"),
  VAR("DebugLogFile",        STRING,   DebugLogFile,         NULL),
  VAR("DataDirectory",       STRING,   DataDirectory,        NULL),
  VAR("DirAllowPrivateAddresses",BOOL, DirAllowPrivateAddresses, NULL),
  VAR("DirPort",             UINT,     DirPort,              "0"),
  VAR("DirBindAddress",      LINELIST, DirBindAddress,       NULL),
/* XXX we'd like dirfetchperiod to be higher for people with dirport not
 * set, but low for people with dirport set. how to have two defaults? */
  VAR("DirFetchPeriod",      INTERVAL, DirFetchPeriod,       "1 hour"),
  VAR("DirPostPeriod",       INTERVAL, DirPostPeriod,        "20 minutes"),
  VAR("RendPostPeriod",      INTERVAL, RendPostPeriod,       "20 minutes"),
  VAR("DirPolicy",           LINELIST, DirPolicy,            NULL),
  VAR("DirServer",           LINELIST, DirServers,           NULL),
  VAR("ExitNodes",           STRING,   ExitNodes,            NULL),
  VAR("EntryNodes",          STRING,   EntryNodes,           NULL),
  VAR("StrictExitNodes",     BOOL,     StrictExitNodes,      "0"),
  VAR("StrictEntryNodes",    BOOL,     StrictEntryNodes,     "0"),
  VAR("ExitPolicy",          LINELIST, ExitPolicy,           NULL),
  VAR("ExcludeNodes",        STRING,   ExcludeNodes,         NULL),
  VAR("FascistFirewall",     BOOL,     FascistFirewall,      "0"),
  VAR("FirewallPorts",       CSV,      FirewallPorts,        "80,443"),
  VAR("MyFamily",            STRING,   MyFamily,             NULL),
  VAR("NodeFamily",          LINELIST, NodeFamilies,         NULL),
  VAR("Group",               STRING,   Group,                NULL),
  VAR("HashedControlPassword",STRING,  HashedControlPassword, NULL),
  VAR("HttpProxy",           STRING,   HttpProxy,            NULL),
  VAR("HiddenServiceOptions",LINELIST_V, RendConfigLines,    NULL),
  VAR("HiddenServiceDir",    LINELIST_S, RendConfigLines,    NULL),
  VAR("HiddenServicePort",   LINELIST_S, RendConfigLines,    NULL),
  VAR("HiddenServiceNodes",  LINELIST_S, RendConfigLines,    NULL),
  VAR("HiddenServiceExcludeNodes", LINELIST_S, RendConfigLines, NULL),
  VAR("IgnoreVersion",       BOOL,     IgnoreVersion,        "0"),
  VAR("KeepalivePeriod",     INTERVAL, KeepalivePeriod,      "5 minutes"),
  VAR("Log",                 LINELIST, Logs,                 NULL),
  VAR("LogLevel",            LINELIST_S, OldLogOptions,      NULL),
  VAR("LogFile",             LINELIST_S, OldLogOptions,      NULL),
  OBSOLETE("LinkPadding"),
  VAR("MaxConn",             UINT,     MaxConn,              "1024"),
  VAR("MaxOnionsPending",    UINT,     MaxOnionsPending,     "100"),
  VAR("MonthlyAccountingStart",UINT,   _MonthlyAccountingStart,"0"),
  VAR("AccountingMaxKB",     UINT,     _AccountingMaxKB,     "0"),
  VAR("AccountingMax",       MEMUNIT,   AccountingMax,        "0 bytes"),
  VAR("Nickname",            STRING,   Nickname,             NULL),
  VAR("NewCircuitPeriod",    INTERVAL, NewCircuitPeriod,     "30 seconds"),
  VAR("MaxCircuitDirtiness", INTERVAL, MaxCircuitDirtiness,  "10 minutes"),
  VAR("NumCpus",             UINT,     NumCpus,              "1"),
  VAR("ORPort",              UINT,     ORPort,               "0"),
  VAR("ORBindAddress",       LINELIST, ORBindAddress,        NULL),
  VAR("OutboundBindAddress", STRING,   OutboundBindAddress,  NULL),
  VAR("PidFile",             STRING,   PidFile,              NULL),
  VAR("LongLivedPorts",      CSV,      LongLivedPorts,       "21,22,706,1863,5050,5190,5222,5223,6667,8300,8888"),
  VAR("PathlenCoinWeight",   DOUBLE,   PathlenCoinWeight,    "0.3"),
  VAR("RedirectExit",        LINELIST, RedirectExit,         NULL),
  OBSOLETE("RouterFile"),
  VAR("RunAsDaemon",         BOOL,     RunAsDaemon,          "0"),
  VAR("RunTesting",          BOOL,     RunTesting,           "0"),
  VAR("RecommendedVersions", LINELIST, RecommendedVersions,  NULL),
  VAR("RendNodes",           STRING,   RendNodes,            NULL),
  VAR("RendExcludeNodes",    STRING,   RendExcludeNodes,     NULL),
  VAR("SocksPort",           UINT,     SocksPort,            "9050"),
  VAR("SocksBindAddress",    LINELIST, SocksBindAddress,     NULL),
  VAR("SocksPolicy",         LINELIST, SocksPolicy,          NULL),
/* XXX as with dirfetchperiod, we want this to be 15 minutes for people
 * with a dirport open, but higher for people without a dirport open. */
  VAR("StatusFetchPeriod",   INTERVAL, StatusFetchPeriod,    "15 minutes"),
  VAR("SysLog",              LINELIST_S, OldLogOptions,      NULL),
  OBSOLETE("TrafficShaping"),
  VAR("User",                STRING,   User,                 NULL),
  { NULL, CONFIG_TYPE_OBSOLETE, 0, NULL }
};
#undef VAR
#undef OBSOLETE

/** Largest allowed config line */
#define CONFIG_LINE_T_MAXLEN 4096

static void config_line_append(struct config_line_t **lst,
                               const char *key, const char *val);
static void option_reset(or_options_t *options, config_var_t *var);
static void options_free(or_options_t *options);
static int option_is_same(or_options_t *o1, or_options_t *o2,const char *name);
static or_options_t *options_dup(or_options_t *old);
static int options_validate(or_options_t *options);
static int options_transition_allowed(or_options_t *old, or_options_t *new);
static int check_nickname_list(const char *lst, const char *name);

static int parse_dir_server_line(const char *line, int validate_only);
static int parse_redirect_line(smartlist_t *result,
                               struct config_line_t *line);
static int parse_log_severity_range(const char *range, int *min_out,
                                    int *max_out);
static int convert_log_option(or_options_t *options,
                              struct config_line_t *level_opt,
                              struct config_line_t *file_opt, int isDaemon);
static int add_single_log_option(or_options_t *options, int minSeverity,
                                 int maxSeverity,
                                 const char *type, const char *fname);
static int normalize_log_options(or_options_t *options);
static int validate_data_directory(or_options_t *options);
static int write_configuration_file(const char *fname, or_options_t *options);

static uint64_t config_parse_memunit(const char *s, int *ok);
static int config_parse_interval(const char *s, int *ok);
static void print_cvs_version(void);

/*
 * 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 *config_fname = NULL;

/** 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; free the old value as necessary.
 */
void
set_options(or_options_t *new_val) {
  if (global_options)
    options_free(global_options);
  global_options = new_val;
}

/** Fetch the active option list, and take actions based on it. All
 * of the things we do should survive being done repeatedly.
 * Return 0 if all goes well, return -1 if it's time to die.
 *
 * Note 1: <b>new_val</b> must have previously been validated with
 * options_validate(), or Tor may freak out and exit.
 *
 * Note 2: We haven't moved all the "act on new configuration" logic
 * here yet.  Some is still in do_hup() and other places.
 */
int
options_act(void) {
  struct config_line_t *cl;
  or_options_t *options = get_options();
  static int libevent_initialized = 0;

  /* XXXX009 We once had a reason to separate start_daemon and finish_daemon:
   *    It let us have the parent process stick around until we were sure Tor
   *    was started.  Should we make start_daemon get called earlier? -NM */
  if (options->RunAsDaemon) {
    start_daemon(options->DataDirectory);
  }
  if (!libevent_initialized) {
    event_init();
    libevent_initialized = 1;
  }

  clear_trusted_dir_servers();
  for (cl = options->DirServers; cl; cl = cl->next) {
    if (parse_dir_server_line(cl->value, 0)<0) {
      log_fn(LOG_ERR,
             "Bug: Previously validated DirServer line could not be added!");
      return -1;
    }
  }

  if (rend_config_services(options, 0)<0) {
    log_fn(LOG_ERR,
           "Bug: Previously validated hidden services line could not be added!");
    return -1;
  }

  /* Setuid/setgid as appropriate */
  if (options->User || options->Group) {
    if (switch_id(options->User, options->Group) != 0) {
      return -1;
    }
  }

  /* Ensure data directory is private; create if possible. */
  if (check_private_dir(options->DataDirectory, CPD_CREATE) != 0) {
    log_fn(LOG_ERR, "Couldn't access/create private data directory %s",
           options->DataDirectory);
    return -1;
  }

  /* Bail out at this point if we're not going to be a server: we want
   * to not fork, and to log stuff to stderr. */
  if (options->command != CMD_RUN_TOR)
    return 0;

  mark_logs_temp(); /* Close current logs once new logs are open. */
  if (config_init_logs(options, 0)<0) /* Configure the log(s) */
    return -1;
  /* Close the temporary log we used while starting up, if it isn't already
   * gone. */
  close_temp_logs();
  add_callback_log(LOG_NOTICE, LOG_ERR, control_event_logmsg);

  if (set_max_file_descriptors(options->MaxConn) < 0)
    return -1;

  {
    smartlist_t *sl = smartlist_create();
    for (cl = options->RedirectExit; cl; cl = cl->next) {
      if (parse_redirect_line(sl, cl)<0)
        return -1;
    }
    set_exit_redirects(sl);
  }

  /* Start backgrounding the process, if requested. */

  /* Finish backgrounding the process */
  if (options->RunAsDaemon) {
    /* We may be calling this for the n'th time (on SIGHUP), but it's safe. */
    finish_daemon();
  }

  /* Write our pid to the pid file. If we do not have write permissions we
   * will log a warning */
  if (options->PidFile)
    write_pidfile(options->PidFile);

  /* Update address policies. */
  parse_socks_policy();
  parse_dir_policy();

  init_cookie_authentication(options->CookieAuthentication);

  /* reload keys as needed for rendezvous services. */
  if (rend_service_load_keys()<0) {
    log_fn(LOG_ERR,"Error loading rendezvous service keys");
    return -1;
  }

  /* Set up accounting */
  if (accounting_parse_options(options, 0)<0) {
    log_fn(LOG_ERR,"Error in accounting options");
    return -1;
  }
  if (accounting_is_enabled(options))
    configure_accounting(time(NULL));

  if (!we_are_hibernating() && retry_all_listeners(1) < 0) {
    log_fn(LOG_ERR,"Failed to bind one of the listener ports.");
    return -1;
  }

#if 0
  {
    char *smin, *smax;
    smin = config_dump_options(options, 1);
    smax = config_dump_options(options, 0);
    log_fn(LOG_DEBUG, "These are our options:\n%s",smax);
    log_fn(LOG_DEBUG, "We changed these options:\n%s",smin);
    tor_free(smin);
    tor_free(smax);
  }
#endif

  /* Since our options changed, we might need to regenerate and upload our
   * server descriptor.  (We could probably be more clever about only calling
   * this when something significant changed.)
   */
  mark_my_descriptor_dirty();

  return 0;
}

/*
 * Functions to parse config options
 */

/** If <b>option</b> is an official abbreviation for a longer option,
 * return the longer option.  Otherwise return <b>option</b>.
 * If <b>command_line</b> is set, apply all abbreviations.  Otherwise, only
 * apply abbreviations that work for the config file and the command line. */
static const char *
expand_abbrev(const char *option, int command_line)
{
  int i;
  for (i=0; config_abbrevs[i].abbreviated; ++i) {
    /* Abbreviations aren't casei. */
    if (!strcasecmp(option,config_abbrevs[i].abbreviated) &&
        (command_line || !config_abbrevs[i].commandline_only)) {
      return config_abbrevs[i].full;
    }
  }
  return option;
}

/** Helper: Read a list of configuration options from the command line. */
static struct config_line_t *
config_get_commandlines(int argc, char **argv)
{
  struct config_line_t *new;
  struct config_line_t *front = NULL;
  char *s;
  int i = 1;

  while (i < argc-1) {
    if (!strcmp(argv[i],"-f") ||
        !strcmp(argv[i],"--hash-password")) {
      i += 2; /* command-line option with argument. ignore them. */
      continue;
    } else if (!strcmp(argv[i],"--list-fingerprint")) {
      i += 1; /* command-line option. ignore it. */
      continue;
    } else if (!strcmp(argv[i],"--nt-service")) {
      i += 1;
      continue;
    }

    new = tor_malloc(sizeof(struct config_line_t));
    s = argv[i];

    while (*s == '-')
      s++;

    new->key = tor_strdup(expand_abbrev(s, 1));
    new->value = tor_strdup(argv[i+1]);

    log(LOG_DEBUG,"Commandline: parsed keyword '%s', value '%s'",
        new->key, new->value);
    new->next = front;
    front = new;
    i += 2;
  }
  return front;
}

/** Helper: allocate a new configuration option mapping 'key' to 'val',
 * append it to *<b>lst</b>. */
static void
config_line_append(struct config_line_t **lst,
                   const char *key,
                   const char *val)
{
  struct config_line_t *newline;

  newline = tor_malloc(sizeof(struct config_line_t));
  newline->key = tor_strdup(key);
  newline->value = tor_strdup(val);
  newline->next = NULL;
  while (*lst)
    lst = &((*lst)->next);

  (*lst) = newline;
}

/** Helper: parse the config string and strdup into key/value
 * strings. Set *result to the list, or NULL if parsing the string
 * failed.  Return 0 on success, -1 on failure. Warn and ignore any
 * misformatted lines. */
int
config_get_lines(char *string, struct config_line_t **result)
{
  struct config_line_t *list = NULL, **next;
  char *k, *v;

  next = &list;
  do {
    string = parse_line_from_str(string, &k, &v);
    if (!string) {
      config_free_lines(list);
      return -1;
    }
    if (k && v) {
      /* This list can get long, so we keep a pointer to the end of it
       * rather than using config_line_append over and over and getting n^2
       * performance.  This is the only really long list. */
      *next = tor_malloc(sizeof(struct config_line_t));
      (*next)->key = tor_strdup(k);
      (*next)->value = tor_strdup(v);
      (*next)->next = NULL;
      next = &((*next)->next);
    }
  } while (*string);

  *result = list;
  return 0;
}

/**
 * Free all the configuration lines on the linked list <b>front</b>.
 */
void
config_free_lines(struct config_line_t *front)
{
  struct config_line_t *tmp;

  while (front) {
    tmp = front;
    front = tmp->next;

    tor_free(tmp->key);
    tor_free(tmp->value);
    tor_free(tmp);
  }
}

/** If <b>key</b> is a configuration option, return the corresponding
 * config_var_t.  Otherwise, if <b>key</b> is a non-standard abbreviation,
 * warn, and return the corresponding config_var_t.  Otherwise return NULL.
 */
static config_var_t *config_find_option(const char *key)
{
  int i;
  size_t keylen = strlen(key);
  if (!keylen)
    return NULL; /* if they say "--" on the commandline, it's not an option */
  /* First, check for an exact (case-insensitive) match */
  for (i=0; config_vars[i].name; ++i) {
    if (!strcasecmp(key, config_vars[i].name))
      return &config_vars[i];
  }
  /* If none, check for an abbreviated match */
  for (i=0; config_vars[i].name; ++i) {
    if (!strncasecmp(key, config_vars[i].name, keylen)) {
      log_fn(LOG_WARN, "The abbreviation '%s' is deprecated. "
          "Tell Nick and Roger to make it official, or just use '%s' instead",
             key, config_vars[i].name);
      return &config_vars[i];
    }
  }
  /* Okay, unrecognized options */
  return NULL;
}

/** If <b>c</b> is a syntactically valid configuration line, update
 * <b>options</b> with its value and return 0.  Otherwise return -1 for bad key,
 * -2 for bad value.
 *
 * If 'reset' is set, and we get a line containing no value, restore the
 * option to its default value.
 */
static int
config_assign_line(or_options_t *options, struct config_line_t *c, int reset)
{
  int i, ok;
  config_var_t *var;
  void *lvalue;

  var = config_find_option(c->key);
  if (!var) {
    log_fn(LOG_WARN, "Unknown option '%s'.  Failing.", c->key);
    return -1;
  }
  /* Put keyword into canonical case. */
  if (strcmp(var->name, c->key)) {
    tor_free(c->key);
    c->key = tor_strdup(var->name);
  }

  if (reset && !strlen(c->value)) {
    option_reset(options, var);
    return 0;
  }

  lvalue = ((char*)options) + var->var_offset;
  switch (var->type) {

  case CONFIG_TYPE_UINT:
    i = tor_parse_long(c->value, 10, 0, INT_MAX, &ok, NULL);
    if (!ok) {
      log(LOG_WARN, "Int keyword '%s %s' is malformed or out of bounds.",
          c->key,c->value);
      return -2;
    }
    *(int *)lvalue = i;
    break;

  case CONFIG_TYPE_INTERVAL: {
    i = config_parse_interval(c->value, &ok);
    if (!ok) {
      return -2;
    }
    *(int *)lvalue = i;
    break;
  }

  case CONFIG_TYPE_MEMUNIT: {
    uint64_t u64 = config_parse_memunit(c->value, &ok);
    if (!ok) {
      return -2;
    }
    *(uint64_t *)lvalue = u64;
    break;
  }

  case CONFIG_TYPE_BOOL:
    i = tor_parse_long(c->value, 10, 0, 1, &ok, NULL);
    if (!ok) {
      log(LOG_WARN, "Boolean keyword '%s' expects 0 or 1.", c->key);
      return -2;
    }
    *(int *)lvalue = i;
    break;

  case CONFIG_TYPE_STRING:
    tor_free(*(char **)lvalue);
    *(char **)lvalue = tor_strdup(c->value);
    break;

  case CONFIG_TYPE_DOUBLE:
    *(double *)lvalue = atof(c->value);
    break;

  case CONFIG_TYPE_CSV:
    if (*(smartlist_t**)lvalue) {
      SMARTLIST_FOREACH(*(smartlist_t**)lvalue, char *, cp, tor_free(cp));
      smartlist_clear(*(smartlist_t**)lvalue);
    } else {
      *(smartlist_t**)lvalue = smartlist_create();
    }

    smartlist_split_string(*(smartlist_t**)lvalue, c->value, ",",
                           SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
    break;

  case CONFIG_TYPE_LINELIST:
  case CONFIG_TYPE_LINELIST_S:
    config_line_append((struct config_line_t**)lvalue, c->key, c->value);
    break;

  case CONFIG_TYPE_OBSOLETE:
    log_fn(LOG_WARN, "Skipping obsolete configuration option '%s'", c->key);
    break;
  case CONFIG_TYPE_LINELIST_V:
    log_fn(LOG_WARN, "Can't provide value for virtual option '%s'", c->key);
    return -2;
  default:
    tor_assert(0);
    break;
  }
  return 0;
}

/** restore the option named <b>key</b> in options to its default value. */
static void
config_reset_line(or_options_t *options, const char *key)
{
  config_var_t *var;

  var = config_find_option(key);
  if (!var)
    return; /* give error on next pass. */

  option_reset(options, var);
}

/** Return true iff key is a valid configuration option. */
int
config_option_is_recognized(const char *key)
{
  config_var_t *var = config_find_option(key);
  return (var != NULL);
}

/** Return a canonicalized list of the options assigned for key.
 */
struct config_line_t *
config_get_assigned_option(or_options_t *options, const char *key)
{
  config_var_t *var;
  const void *value;
  char buf[32];
  struct config_line_t *result;
  tor_assert(options && key);

  var = config_find_option(key);
  if (!var) {
    log_fn(LOG_WARN, "Unknown option '%s'.  Failing.", key);
    return NULL;
  } else if (var->type == CONFIG_TYPE_LINELIST_S) {
    log_fn(LOG_WARN, "Can't return context-sensitive '%s' on its own", key);
    return NULL;
  }
  value = ((char*)options) + var->var_offset;

  if (var->type == CONFIG_TYPE_LINELIST ||
      var->type == CONFIG_TYPE_LINELIST_V) {
    /* Linelist requires special handling: we just copy and return it. */
    const struct config_line_t *next_in = *(const struct config_line_t**)value;
    struct config_line_t **next_out = &result;
    while (next_in) {
      *next_out = tor_malloc(sizeof(struct config_line_t));
      (*next_out)->key = tor_strdup(next_in->key);
      (*next_out)->value = tor_strdup(next_in->value);
      next_in = next_in->next;
      next_out = &((*next_out)->next);
    }
    (*next_out) = NULL;
    return result;
  }

  result = tor_malloc_zero(sizeof(struct config_line_t));
  result->key = tor_strdup(var->name);
  switch (var->type)
    {
    case CONFIG_TYPE_STRING:
      if (*(char**)value) {
        result->value = tor_strdup(*(char**)value);
      } else {
        tor_free(result->key);
        tor_free(result);
        return NULL;
      }
      break;
    case CONFIG_TYPE_INTERVAL:
    case CONFIG_TYPE_UINT:
      /* This means every or_options_t uint or bool element
       * needs to be an int. Not, say, a uint16_t or char. */
      tor_snprintf(buf, sizeof(buf), "%d", *(int*)value);
      result->value = tor_strdup(buf);
      break;
    case CONFIG_TYPE_MEMUNIT:
      tor_snprintf(buf, sizeof(buf), U64_FORMAT,
                   U64_PRINTF_ARG(*(uint64_t*)value));
      result->value = tor_strdup(buf);
      break;
    case CONFIG_TYPE_DOUBLE:
      tor_snprintf(buf, sizeof(buf), "%f", *(double*)value);
      result->value = tor_strdup(buf);
      break;
    case CONFIG_TYPE_BOOL:
      result->value = tor_strdup(*(int*)value ? "1" : "0");
      break;
    case CONFIG_TYPE_CSV:
      if (*(smartlist_t**)value)
        result->value = smartlist_join_strings(*(smartlist_t**)value,",",0,NULL);
      else
        result->value = tor_strdup("");
      break;
    case CONFIG_TYPE_OBSOLETE:
      log_fn(LOG_WARN,"You asked me for the value of an obsolete config option %s.", key);
      tor_free(result->key);
      tor_free(result);
      return NULL;
    default:
      tor_free(result->key);
      tor_free(result);
      log_fn(LOG_WARN,"Bug: unknown type %d for known key %s", var->type, key);
      return NULL;
    }

  return result;
}

/** Iterate through the linked list of requested options <b>list</b>.
 * For each item, convert as appropriate and assign to <b>options</b>.
 * If an item is unrecognized, return -1 immediately,
 * else return 0 for success.
 *
 * If <b>reset</b>, then interpret empty lines as meaning "restore to
 * default value", and interpret LINELIST* options as replacing (not
 * extending) their previous values.  Return 0 on success, -1 on bad key,
 * -2 on bad value.
 */
static int
config_assign(or_options_t *options, struct config_line_t *list, int reset)
{
  struct config_line_t *p;
  tor_assert(options);

  /* pass 1: normalize keys */
  for (p = list; p; p = p->next) {
    const char *full = expand_abbrev(p->key, 0);
    if (strcmp(full,p->key)) {
      tor_free(p->key);
      p->key = tor_strdup(full);
    }
  }

  /* pass 2: if we're reading from a resetting source, clear all mentioned
   * linelists. */
  if (reset) {
    for (p = list; p; p = p->next)
      config_reset_line(options, p->key);
  }

  /* pass 3: assign. */
  while (list) {
    int r;
    if ((r=config_assign_line(options, list, reset)))
      return r;
    list = list->next;
  }
  return 0;
}

/** Try assigning <b>list</b> to the global options. You do this by duping
 * options, assigning list to the new one, then validating it. If it's
 * ok, then throw out the old one and stick with the new one. Else,
 * revert to old and return failure.  Return 0 on success, -1 on bad
 * keys, -2 on bad values, -3 on bad transition.
 */
int
config_trial_assign(struct config_line_t *list, int reset)
{
  int r;
  or_options_t *trial_options = options_dup(get_options());

  if ((r=config_assign(trial_options, list, reset)) < 0) {
    options_free(trial_options);
    return r;
  }

  if (options_validate(trial_options) < 0) {
    options_free(trial_options);
    return -2;
  }

  if (options_transition_allowed(get_options(), trial_options) < 0) {
    options_free(trial_options);
    return -3;
  }

  set_options(trial_options); /* we liked it. put it in place. */
  return 0;
}

/** Replace the option indexed by <b>var</b> in <b>options</b> with its
 * default value. */
static void
option_reset(or_options_t *options, config_var_t *var)
{
  struct config_line_t *c;
  void *lvalue;

  lvalue = ((char*)options) + var->var_offset;
  switch (var->type) {
    case CONFIG_TYPE_STRING:
      tor_free(*(char**)lvalue);
      break;
    case CONFIG_TYPE_DOUBLE:
      *(double*)lvalue = 0.0;
      break;
    case CONFIG_TYPE_INTERVAL:
    case CONFIG_TYPE_UINT:
    case CONFIG_TYPE_BOOL:
      *(int*)lvalue = 0;
      break;
    case CONFIG_TYPE_MEMUNIT:
      *(uint64_t*)lvalue = 0;
      break;
    case CONFIG_TYPE_CSV:
      if (*(smartlist_t**)lvalue) {
        SMARTLIST_FOREACH(*(smartlist_t **)lvalue, char *, cp, tor_free(cp));
        smartlist_free(*(smartlist_t **)lvalue);
        *(smartlist_t **)lvalue = NULL;
      }
      break;
    case CONFIG_TYPE_LINELIST:
    case CONFIG_TYPE_LINELIST_S:
      config_free_lines(*(struct config_line_t **)lvalue);
      *(struct config_line_t **)lvalue = NULL;
      break;
    case CONFIG_TYPE_LINELIST_V:
      /* handled by linelist_s. */
      break;
    case CONFIG_TYPE_OBSOLETE:
      break;
  }
  if (var->initvalue) {
    c = tor_malloc_zero(sizeof(struct config_line_t));
    c->key = tor_strdup(var->name);
    c->value = tor_strdup(var->initvalue);
    config_assign_line(options,c,0);
    config_free_lines(c);
  }
}

/** Set <b>options</b>-&gt;DirServers to contain the default directory
 * servers. */
static void
add_default_trusted_dirservers(or_options_t *options)
{
  /* moria1 */
  config_line_append(&options->DirServers, "DirServer",
       "18.244.0.188:9031 FFCB 46DB 1339 DA84 674C 70D7 CB58 6434 C437 0441");
  /* moria2 */
  config_line_append(&options->DirServers, "DirServer",
         "18.244.0.114:80 719B E45D E224 B607 C537 07D0 E214 3E2D 423E 74CF");
  /* tor26 */
  config_line_append(&options->DirServers, "DirServer",
     "62.116.124.106:9030 847B 1F85 0344 D787 6491 A548 92F9 0493 4E4E B85D");
//  "tor.noreply.org:9030 847B 1F85 0344 D787 6491 A548 92F9 0493 4E4E B85D");
}

/** Print a usage message for tor. */
static void
print_usage(void)
{
  printf(
"Copyright 2001-2004 Roger Dingledine, Nick Mathewson, Matej Pfajfar.\n\n"
"tor -f <torrc> [args]\n"
"See man page for options, or http://tor.eff.org/ for documentation.\n");
}

/**
 * Based on <b>address</b>, guess our public IP address and put it
 * in <b>addr</b>.
 */
int
resolve_my_address(const char *address, uint32_t *addr)
{
  struct in_addr in;
  struct hostent *rent;
  char hostname[256];
  int explicit_ip=1;

  tor_assert(addr);

  if (address) {
    strlcpy(hostname, address, sizeof(hostname));
  } else { /* then we need to guess our address */
    explicit_ip = 0; /* it's implicit */

    if (gethostname(hostname, sizeof(hostname)) < 0) {
      log_fn(LOG_WARN,"Error obtaining local hostname");
      return -1;
    }
    log_fn(LOG_DEBUG,"Guessed local host name as '%s'",hostname);
  }

  /* now we know hostname. resolve it and keep only the IP */

  if (tor_inet_aton(hostname, &in) == 0) {
    /* then we have to resolve it */
    explicit_ip = 0;
    rent = (struct hostent *)gethostbyname(hostname);
    if (!rent) {
      log_fn(LOG_WARN,"Could not resolve local Address %s. Failing.", hostname);
      return -1;
    }
    tor_assert(rent->h_length == 4);
    memcpy(&in.s_addr, rent->h_addr, rent->h_length);
  }

  if (!explicit_ip && is_internal_IP(htonl(in.s_addr))) {
    log_fn(LOG_WARN,"Address '%s' resolves to private IP '%s'. "
           "Please set the Address config option to be the IP you want to use.",
           hostname, inet_ntoa(in));
    return -1;
  }

  log_fn(LOG_DEBUG, "Resolved Address to %s.", inet_ntoa(in));
  *addr = ntohl(in.s_addr);
  return 0;
}

/** Called when we don't have a nickname set.  Try to guess a good
 * nickname based on the hostname, and return it in a newly allocated string. */
static char *
get_default_nickname(void)
{
  char localhostname[256];
  char *cp, *out, *outp;

  if (gethostname(localhostname, sizeof(localhostname)) < 0) {
    log_fn(LOG_WARN,"Error obtaining local hostname");
    return NULL;
  }

  /* Put it in lowercase; stop at the first dot. */
  for (cp = localhostname; *cp; ++cp) {
    if (*cp == '.') {
      *cp = '\0';
      break;
    }
    *cp = tolower(*cp);
  }

  /* Strip invalid characters. */
  cp = localhostname;
  out = outp = tor_malloc(strlen(localhostname) + 1);
  while (*cp) {
    if (strchr(LEGAL_NICKNAME_CHARACTERS, *cp))
      *outp++ = *cp++;
    else
      cp++;
  }
  *outp = '\0';

  /* Enforce length. */
  if (strlen(out) > MAX_NICKNAME_LEN)
    out[MAX_NICKNAME_LEN]='\0';

  return out;
}

/** Release storage held by <b>options</b> */
static void
options_free(or_options_t *options)
{
  int i;
  void *lvalue;

  tor_assert(options);

  for (i=0; config_vars[i].name; ++i) {
    lvalue = ((char*)options) + config_vars[i].var_offset;
    switch (config_vars[i].type) {
      case CONFIG_TYPE_MEMUNIT:
      case CONFIG_TYPE_INTERVAL:
      case CONFIG_TYPE_UINT:
      case CONFIG_TYPE_BOOL:
      case CONFIG_TYPE_DOUBLE:
      case CONFIG_TYPE_OBSOLETE:
        break; /* nothing to free for these config types */
      case CONFIG_TYPE_STRING:
        tor_free(*(char **)lvalue);
        break;
      case CONFIG_TYPE_LINELIST:
      case CONFIG_TYPE_LINELIST_V:
        config_free_lines(*(struct config_line_t**)lvalue);
        *(struct config_line_t**)lvalue = NULL;
        break;
      case CONFIG_TYPE_CSV:
        if (*(smartlist_t**)lvalue) {
          SMARTLIST_FOREACH(*(smartlist_t**)lvalue, char *, cp, tor_free(cp));
          smartlist_free(*(smartlist_t**)lvalue);
          *(smartlist_t**)lvalue = NULL;
        }
        break;
      case CONFIG_TYPE_LINELIST_S:
        /* will be freed by corresponding LINELIST_V. */
        break;
    }
  }
  tor_free(options);
}

/** Return true iff the option <b>var</b> has the same value in <b>o1</b>
 * and <b>o2</b>.  Must not be called for LINELIST_S or OBSOLETE options.
 */
static int
option_is_same(or_options_t *o1, or_options_t *o2, const char *name)
{
  struct config_line_t *c1, *c2;
  int r = 1;
  c1 = config_get_assigned_option(o1, name);
  c2 = config_get_assigned_option(o2, name);
  while (c1 && c2) {
    if (strcasecmp(c1->key, c2->key) ||
        strcmp(c1->value, c2->value)) {
      r = 0;
      break;
    }
    c1 = c1->next;
    c2 = c2->next;
  }
  if (r && (c1 || c2)) {
    r = 0;
  }
  config_free_lines(c1);
  config_free_lines(c2);
  return r;
}

/** Copy storage held by <b>old</b> into a new or_options_t and return it. */
static or_options_t *
options_dup(or_options_t *old)
{
  or_options_t *newopts;
  int i;
  struct config_line_t *line;

  newopts = tor_malloc_zero(sizeof(or_options_t));
  for (i=0; config_vars[i].name; ++i) {
    if (config_vars[i].type == CONFIG_TYPE_LINELIST_S)
      continue;
    if (config_vars[i].type == CONFIG_TYPE_OBSOLETE)
      continue;
    line = config_get_assigned_option(old, config_vars[i].name);
    if (line) {
      if (config_assign(newopts, line, 0) < 0) {
        log_fn(LOG_WARN,"Bug: config_get_assigned_option() generated "
               "something we couldn't config_assign().");
        tor_assert(0);
      }
    }
    config_free_lines(line);
  }
  return newopts;
}

/** Set <b>options</b> to hold reasonable defaults for most options.
 * Each option defaults to zero. */
void
options_init(or_options_t *options)
{
  int i;
  config_var_t *var;

  for (i=0; config_vars[i].name; ++i) {
    var = &config_vars[i];
    if (!var->initvalue)
      continue; /* defaults to NULL or 0 */
    option_reset(options, var);
  }
}

/** Return a string containing a possible configuration file that would give
 * the configuration in <b>options</b>.  If <b>minimal</b> is true, do not
 * include options that are the same as Tor's defaults.
 */
char *
config_dump_options(or_options_t *options, int minimal)
{
  smartlist_t *elements;
  or_options_t *defaults;
  struct config_line_t *line;
  char *result;
  int i;

  defaults = tor_malloc_zero(sizeof(or_options_t));
  options_init(defaults);
  options_validate(defaults); /* ??? will this work? */

  elements = smartlist_create();
  for (i=0; config_vars[i].name; ++i) {
    if (config_vars[i].type == CONFIG_TYPE_OBSOLETE ||
        config_vars[i].type == CONFIG_TYPE_LINELIST_S)
      continue;
    if (minimal && option_is_same(options, defaults, config_vars[i].name))
      continue;
    line = config_get_assigned_option(options, config_vars[i].name);
    for (; line; line = line->next) {
      size_t len = strlen(line->key) + strlen(line->value) + 3;
      char *tmp;
      tmp = tor_malloc(len);
      if (tor_snprintf(tmp, len, "%s %s\n", line->key, line->value)<0) {
        log_fn(LOG_ERR, "Internal error writing log option");
        tor_assert(0);
      }
      smartlist_add(elements, tmp);
    }
    config_free_lines(line);
  }

  result = smartlist_join_strings(elements, "", 0, NULL);
  SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp));
  smartlist_free(elements);
  return result;
}

static int
validate_ports_csv(smartlist_t *sl, char *name) {
  int i;
  int result = 0;
  tor_assert(name);

  if (!sl)
    return 0;

  SMARTLIST_FOREACH(sl, const char *, cp,
  {
    i = atoi(cp);
    if (i < 1 || i > 65535) {
      log(LOG_WARN, "Port '%s' out of range in %s", cp, name);
      result=-1;
    }
  });
  return result;
}

/** Return 0 if every setting in <b>options</b> is reasonable.  Else
 * warn and return -1.  Should have no side effects, except for
 * normalizing the contents of <b>options</b>. */
static int
options_validate(or_options_t *options)
{
  int result = 0;
  struct config_line_t *cl;
  addr_policy_t *addr_policy=NULL;

  if (options->ORPort < 0 || options->ORPort > 65535) {
    log(LOG_WARN, "ORPort option out of bounds.");
    result = -1;
  }

  /* XXX might similarly want to check the other *BindAddress options */
  if (options->ORPort == 0 && options->ORBindAddress != NULL) {
    log(LOG_WARN, "ORPort must be defined if ORBindAddress is defined.");
    result = -1;
  }

  if (validate_data_directory(options)<0) {
    log(LOG_WARN, "Invalid DataDirectory");
    result = -1;
  }

  if (options->Nickname == NULL) {
    if (server_mode(options)) {
      if (!(options->Nickname = get_default_nickname()))
        return -1;
      log_fn(LOG_NOTICE, "Choosing default nickname %s", options->Nickname);
    }
  } else {
    if (strspn(options->Nickname, LEGAL_NICKNAME_CHARACTERS) !=
        strlen(options->Nickname)) {
      log_fn(LOG_WARN, "Nickname '%s' contains illegal characters.", options->Nickname);
      result = -1;
    }
    if (strlen(options->Nickname) == 0) {
      log_fn(LOG_WARN, "Nickname must have at least one character");
      result = -1;
    }
    if (strlen(options->Nickname) > MAX_NICKNAME_LEN) {
      log_fn(LOG_WARN, "Nickname '%s' has more than %d characters.",
             options->Nickname, MAX_NICKNAME_LEN);
      result = -1;
    }
  }

  if (normalize_log_options(options))
    return -1;

  /* Special case if no options are given. */
  if (!options->Logs) {
    config_line_append(&options->Logs, "Log", "notice stdout");
  }

  if (config_init_logs(options, 1)<0) /* Validate the log(s) */
    return -1;

  if (server_mode(options)) {
    /* confirm that our address isn't broken, so we can complain now */
    uint32_t tmp;
    if (resolve_my_address(options->Address, &tmp) < 0)
      result = -1;
  }

  if (options->SocksPort < 0 || options->SocksPort > 65535) {
    log(LOG_WARN, "SocksPort option out of bounds.");
    result = -1;
  }

  if (options->SocksPort == 0 && options->ORPort == 0) {
    log(LOG_WARN, "SocksPort and ORPort are both undefined? Quitting.");
    result = -1;
  }

  if (options->ControlPort < 0 || options->ControlPort > 65535) {
    log(LOG_WARN, "ControlPort option out of bounds.");
    result = -1;
  }

  if (options->DirPort < 0 || options->DirPort > 65535) {
    log(LOG_WARN, "DirPort option out of bounds.");
    result = -1;
  }

  if (options->StrictExitNodes &&
      (!options->ExitNodes || !strlen(options->ExitNodes))) {
    log(LOG_WARN, "StrictExitNodes set, but no ExitNodes listed.");
  }

  if (options->StrictEntryNodes &&
      (!options->EntryNodes || !strlen(options->EntryNodes))) {
    log(LOG_WARN, "StrictEntryNodes set, but no EntryNodes listed.");
  }

  if (options->AuthoritativeDir && options->RecommendedVersions == NULL) {
    log(LOG_WARN, "Directory servers must configure RecommendedVersions.");
    result = -1;
  }

  if (options->AuthoritativeDir && !options->DirPort) {
    log(LOG_WARN, "Running as authoritative directory, but no DirPort set.");
    result = -1;
  }

  if (options->AuthoritativeDir && !options->ORPort) {
    log(LOG_WARN, "Running as authoritative directory, but no ORPort set.");
    result = -1;
  }

  if (options->AuthoritativeDir && options->ClientOnly) {
    log(LOG_WARN, "Running as authoritative directory, but ClientOnly also set.");
    result = -1;
  }

  if (options->_AccountingMaxKB) {
    log(LOG_WARN, "AccountingMaxKB is deprecated.  Say 'AccountingMax %d KB' instead.", options->_AccountingMaxKB);
    options->AccountingMax = U64_LITERAL(1024)*options->_AccountingMaxKB;
    options->_AccountingMaxKB = 0;
  }

  if (validate_ports_csv(options->FirewallPorts,
                         "FirewallPorts") < 0)
    result = -1;

  if (validate_ports_csv(options->LongLivedPorts,
                         "LongLivedPorts") < 0)
    result = -1;

  options->_AllowUnverified = 0;
  if (options->AllowUnverifiedNodes) {
    SMARTLIST_FOREACH(options->AllowUnverifiedNodes, const char *, cp, {
        if (!strcasecmp(cp, "entry"))
          options->_AllowUnverified |= ALLOW_UNVERIFIED_ENTRY;
        else if (!strcasecmp(cp, "exit"))
          options->_AllowUnverified |= ALLOW_UNVERIFIED_EXIT;
        else if (!strcasecmp(cp, "middle"))
          options->_AllowUnverified |= ALLOW_UNVERIFIED_MIDDLE;
        else if (!strcasecmp(cp, "introduction"))
          options->_AllowUnverified |= ALLOW_UNVERIFIED_INTRODUCTION;
        else if (!strcasecmp(cp, "rendezvous"))
          options->_AllowUnverified |= ALLOW_UNVERIFIED_RENDEZVOUS;
        else {
          log(LOG_WARN, "Unrecognized value '%s' in AllowUnverifiedNodes",
              cp);
          result = -1;
        }
      });
  }

  if (options->SocksPort >= 1 &&
      (options->PathlenCoinWeight < 0.0 || options->PathlenCoinWeight >= 1.0)) {
    log(LOG_WARN, "PathlenCoinWeight option must be >=0.0 and <1.0.");
    result = -1;
  }

  if (options->MaxConn < 1) {
    log(LOG_WARN, "MaxConn option must be a non-zero positive integer.");
    result = -1;
  }

  if (options->MaxConn > MAXCONNECTIONS) {
    log(LOG_WARN, "MaxConn option must be at most %d.", MAXCONNECTIONS);
    result = -1;
  }

#define MIN_DIR_FETCH_PERIOD 600
#define MIN_DIR_POST_PERIOD 300
#define MIN_REND_POST_PERIOD 300
#define MIN_STATUS_FETCH_PERIOD 60

#define MAX_DIR_PERIOD (MIN_ONION_KEY_LIFETIME/2)
#define MAX_CACHE_DIR_FETCH_PERIOD 3600
#define MAX_CACHE_STATUS_FETCH_PERIOD 900

  if (options->DirFetchPeriod < MIN_DIR_FETCH_PERIOD) {
    log(LOG_WARN, "DirFetchPeriod option must be at least %d seconds. Clipping.", MIN_DIR_FETCH_PERIOD);
    options->DirFetchPeriod = MIN_DIR_FETCH_PERIOD;
  }
  if (options->StatusFetchPeriod < MIN_STATUS_FETCH_PERIOD) {
    log(LOG_WARN, "StatusFetchPeriod option must be at least %d seconds. Clipping.", MIN_STATUS_FETCH_PERIOD);
    options->StatusFetchPeriod = MIN_STATUS_FETCH_PERIOD;
  }
  if (options->DirPostPeriod < MIN_DIR_POST_PERIOD) {
    log(LOG_WARN, "DirPostPeriod option must be at least %d seconds. Clipping.",
        MIN_DIR_POST_PERIOD);
    options->DirPostPeriod = MIN_DIR_POST_PERIOD;
  }
  if (options->RendPostPeriod < MIN_REND_POST_PERIOD) {
    log(LOG_WARN,"RendPostPeriod option must be at least %d seconds. Clipping.",
        MIN_REND_POST_PERIOD);
    options->RendPostPeriod = MIN_REND_POST_PERIOD;
  }

  if (options->DirPort && ! options->AuthoritativeDir) {
    if (options->DirFetchPeriod > MAX_CACHE_DIR_FETCH_PERIOD) {
      log(LOG_WARN, "Caching directory servers must have DirFetchPeriod less than %d seconds. Clipping.", MAX_CACHE_DIR_FETCH_PERIOD);
      options->DirFetchPeriod = MAX_CACHE_DIR_FETCH_PERIOD;
    }
    if (options->StatusFetchPeriod > MAX_CACHE_STATUS_FETCH_PERIOD) {
      log(LOG_WARN, "Caching directory servers must have StatusFetchPeriod less than %d seconds. Clipping.", MAX_CACHE_STATUS_FETCH_PERIOD);
      options->StatusFetchPeriod = MAX_CACHE_STATUS_FETCH_PERIOD;
    }
  }

  if (options->DirFetchPeriod > MAX_DIR_PERIOD) {
    log(LOG_WARN, "DirFetchPeriod is too large; clipping.");
    options->DirFetchPeriod = MAX_DIR_PERIOD;
  }
  if (options->DirPostPeriod > MAX_DIR_PERIOD) {
    log(LOG_WARN, "DirPostPeriod is too large; clipping.");
    options->DirPostPeriod = MAX_DIR_PERIOD;
  }
  if (options->StatusFetchPeriod > MAX_DIR_PERIOD) {
    log(LOG_WARN, "StatusFetchPeriod is too large; clipping.");
    options->StatusFetchPeriod = MAX_DIR_PERIOD;
  }
  if (options->RendPostPeriod > MAX_DIR_PERIOD) {
    log(LOG_WARN, "RendPostPeriod is too large; clipping.");
    options->RendPostPeriod = MAX_DIR_PERIOD;
  }

  if (options->KeepalivePeriod < 1) {
    log(LOG_WARN,"KeepalivePeriod option must be positive.");
    result = -1;
  }

  if (options->BandwidthRate > INT_MAX) {
    log(LOG_WARN,"BandwidthRate must be less than %d",INT_MAX);
    result = -1;
  }
  if (options->BandwidthBurst > INT_MAX) {
    log(LOG_WARN,"BandwidthBurst must be less than %d",INT_MAX);
    result = -1;
  }
  if (server_mode(options) &&
      options->BandwidthRate < ROUTER_REQUIRED_MIN_BANDWIDTH*2) {
    log(LOG_WARN,"BandwidthRate is set to %d bytes/second. For servers, it must be at least %d.", (int)options->BandwidthRate, ROUTER_REQUIRED_MIN_BANDWIDTH*2);
    result = -1;
  }
  if (options->BandwidthRate > options->BandwidthBurst) {
    log(LOG_WARN,"BandwidthBurst must be at least equal to BandwidthRate.");
    result = -1;
  }
#if 0
  if (2*options->BandwidthRate > options->BandwidthBurst) {
    log(LOG_NOTICE,"You have chosen a BandwidthBurst less than twice BandwidthRate. Please consider setting your BandwidthBurst higher (at least %d), to provide better service to the Tor network.", (int)(2*options->BandwidthRate));
  }
#endif

  if (options->_MonthlyAccountingStart) {
    if (options->AccountingStart) {
      log(LOG_WARN,"Can't specify AccountingStart and MonthlyAccountingStart");
      result = -1;
    } else {
      options->AccountingStart = tor_malloc(32);
      if (tor_snprintf(options->AccountingStart, 32, "month %d 0:00",
                       options->_MonthlyAccountingStart)<0) {
        log_fn(LOG_WARN,"Error translating MonthlyAccountingStart");
        result = -1;
      } else {
        log_fn(LOG_WARN,"MonthlyAccountingStart is deprecated.  Use 'AccountingStart %s' instead.", options->AccountingStart);
      }
    }
  }

  if (accounting_parse_options(options, 1)<0) {
    result = -1;
  }

  if (options->HttpProxy) { /* parse it now */
    if (parse_addr_port(options->HttpProxy, NULL,
                        &options->HttpProxyAddr, &options->HttpProxyPort) < 0) {
      log(LOG_WARN,"HttpProxy failed to parse or resolve. Please fix.");
      result = -1;
    }
    if (options->HttpProxyPort == 0) { /* give it a default */
      options->HttpProxyPort = 80;
    }
  }

  if (options->HashedControlPassword) {
    if (decode_hashed_password(NULL, options->HashedControlPassword)<0) {
      log_fn(LOG_WARN,"Bad HashedControlPassword: wrong length or bad base64");
      result = -1;
    }
  }
  if (options->HashedControlPassword && options->CookieAuthentication) {
    log_fn(LOG_WARN,"Cannot enable both HashedControlPassword and CookieAuthentication");
    result = -1;
  }

  if (check_nickname_list(options->ExitNodes, "ExitNodes"))
    result = -1;
  if (check_nickname_list(options->EntryNodes, "EntryNodes"))
    result = -1;
  if (check_nickname_list(options->ExcludeNodes, "ExcludeNodes"))
    result = -1;
  if (check_nickname_list(options->RendNodes, "RendNodes"))
    result = -1;
  if (check_nickname_list(options->RendNodes, "RendExcludeNodes"))
    result = -1;
  if (check_nickname_list(options->MyFamily, "MyFamily"))
    result = -1;
  for (cl = options->NodeFamilies; cl; cl = cl->next) {
    if (check_nickname_list(cl->value, "NodeFamily"))
      result = -1;
  }

  if (config_parse_addr_policy(options->ExitPolicy, &addr_policy)) {
    log_fn(LOG_WARN, "Error in Exit Policy entry.");
    result = -1;
  }
  if (server_mode(options)) {
    exit_policy_implicitly_allows_local_networks(addr_policy, 1);
  }
  /* The rest of these calls *append* to addr_policy. So don't actually
   * use the results for anything other than checking if they parse! */
  if (config_parse_addr_policy(options->DirPolicy, &addr_policy)) {
    log_fn(LOG_WARN, "Error in DirPolicy entry.");
    result = -1;
  }
  if (config_parse_addr_policy(options->SocksPolicy, &addr_policy)) {
    log_fn(LOG_WARN, "Error in SocksPolicy entry.");
    result = -1;
  }
  addr_policy_free(addr_policy);

  for (cl = options->RedirectExit; cl; cl = cl->next) {
    if (parse_redirect_line(NULL, cl)<0)
      result = -1;
  }

  if (!options->DirServers) {
    add_default_trusted_dirservers(options);
  } else {
    for (cl = options->DirServers; cl; cl = cl->next) {
      if (parse_dir_server_line(cl->value, 1)<0)
        result = -1;
    }
  }

  if (rend_config_services(options, 1) < 0)
    result = -1;

  return result;
}

/** Helper: return true iff s1 and s2 are both NULL, or both non-NULL
 * equal strings. */
static int
opt_streq(const char *s1, const char *s2)
{
  if (!s1 && !s2)
    return 1;
  else if (s1 && s2 && !strcmp(s1,s2))
    return 1;
  else
    return 0;
}

/** Check if any of the previous options have changed but aren't allowed to. */
static int
options_transition_allowed(or_options_t *old, or_options_t *new_val) {

  if (!old)
    return 0;

  if (!opt_streq(old->PidFile, new_val->PidFile)) {
    log_fn(LOG_WARN,"PidFile is not allowed to change. Failing.");
    return -1;
  }

  if (old->RunAsDaemon && !new_val->RunAsDaemon) {
    log_fn(LOG_WARN,"During reload, change from RunAsDaemon=1 to =0 not allowed. Failing.");
    return -1;
  }

  if (old->ORPort != new_val->ORPort) {
    log_fn(LOG_WARN,"During reload, changing ORPort is not allowed. Failing.");
    return -1;
  }

  if (strcmp(old->DataDirectory,new_val->DataDirectory)!=0) {
    log_fn(LOG_WARN,"During reload, changing DataDirectory (%s->%s) is not allowed. Failing.", old->DataDirectory, new_val->DataDirectory);
    return -1;
  }

  if (!opt_streq(old->User, new_val->User)) {
    log_fn(LOG_WARN,"During reload, changing User is not allowed. Failing.");
    return -1;
  }

  if (!opt_streq(old->Group, new_val->Group)) {
    log_fn(LOG_WARN,"During reload, changing User is not allowed. Failing.");
    return -1;
  }

  return 0;
}

#ifdef MS_WINDOWS
/** Return the directory on windows where we expect to find our application
 * data. */
static char *get_windows_conf_root(void)
{
  static int is_set = 0;
  static char path[MAX_PATH+1];

  LPITEMIDLIST idl;
  IMalloc *m;
  HRESULT result;

  if (is_set)
    return path;

  /* Find X:\documents and settings\username\application data\ .
   * We would use SHGetSpecialFolder path, but that wasn't added until IE4.
   */
  if (!SUCCEEDED(SHGetSpecialFolderLocation(NULL, CSIDL_APPDATA,
                                            &idl))) {
    GetCurrentDirectory(MAX_PATH, path);
    is_set = 1;
    log_fn(LOG_WARN, "I couldn't find your application data folder: are you running an ancient version of Windows 95? Defaulting to '%s'", path);
    return path;
  }
  /* Convert the path from an "ID List" (whatever that is!) to a path. */
  result = SHGetPathFromIDList(idl, path);
  /* Now we need to free the */
  SHGetMalloc(&m);
  if (m) {
    m->lpVtbl->Free(m, idl);
    m->lpVtbl->Release(m);
  }
  if (!SUCCEEDED(result)) {
    return NULL;
  }
  strlcat(path,"\\tor",MAX_PATH);
  is_set = 1;
  return path;
}
#endif

/** Return the default location for our torrc file. */
static char *
get_default_conf_file(void)
{
#ifdef MS_WINDOWS
  char *path = tor_malloc(MAX_PATH);
  strlcpy(path, get_windows_conf_root(), MAX_PATH);
  strlcat(path,"\\torrc",MAX_PATH);
  return path;
#else
  return tor_strdup(CONFDIR "/torrc");
#endif
}

/** Verify whether lst is a string containing valid-looking space-separated
 * nicknames, or NULL. Return 0 on success. Warn and return -1 on failure.
 */
static int check_nickname_list(const char *lst, const char *name)
{
  int r = 0;
  smartlist_t *sl;

  if (!lst)
    return 0;
  sl = smartlist_create();
  smartlist_split_string(sl, lst, ",", SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
  SMARTLIST_FOREACH(sl, const char *, s,
    {
      if (!is_legal_nickname_or_hexdigest(s)) {
        log_fn(LOG_WARN, "Invalid nickname '%s' in %s line", s, name);
        r = -1;
      }
    });
  SMARTLIST_FOREACH(sl, char *, s, tor_free(s));
  smartlist_free(sl);
  return r;
}

/** Read a configuration file into <b>options</b>, finding the configuration
 * file location based on the command line.  After loading the options,
 * validate them for consistency, then take actions based on them.
 * Return 0 if success, -1 if failure. */
int
init_from_config(int argc, char **argv)
{
  or_options_t *oldoptions, *newoptions;
  struct config_line_t *cl;
  char *cf=NULL, *fname=NULL;
  int i, retval;
  int using_default_torrc;
  static char **backup_argv;
  static int backup_argc;

  if (argv) { /* first time we're called. save commandline args */
    backup_argv = argv;
    backup_argc = argc;
    oldoptions = NULL;
  } else { /* we're reloading. need to clean up old options first. */
    argv = backup_argv;
    argc = backup_argc;
    oldoptions = get_options();
  }
  if (argc > 1 && (!strcmp(argv[1], "-h") || !strcmp(argv[1],"--help"))) {
    print_usage();
    exit(0);
  }

  if (argc > 1 && (!strcmp(argv[1],"--version"))) {
    printf("Tor version %s.\n",VERSION);
    if (argc > 2 && (!strcmp(argv[2],"--version"))) {
      print_cvs_version();
    }
    exit(0);
  }

  newoptions = tor_malloc_zero(sizeof(or_options_t));
  options_init(newoptions);

  /* learn config file name, get config lines, assign them */
  fname = NULL;
  using_default_torrc = 1;
  newoptions->command = CMD_RUN_TOR;
  for (i = 1; i < argc; ++i) {
    if (i < argc-1 && !strcmp(argv[i],"-f")) {
      if (fname) {
        log(LOG_WARN, "Duplicate -f options on command line.");
        tor_free(fname);
      }
      fname = tor_strdup(argv[i+1]);
      using_default_torrc = 0;
      ++i;
    } else if (!strcmp(argv[i],"--list-fingerprint")) {
      newoptions->command = CMD_LIST_FINGERPRINT;
    } else if (!strcmp(argv[i],"--hash-password")) {
      newoptions->command = CMD_HASH_PASSWORD;
      newoptions->command_arg = tor_strdup( (i < argc-1) ? argv[i+1] : "");
      ++i;
    }
  }

  if (using_default_torrc) {
    /* didn't find one, try CONFDIR */
    char *fn;
    fn = get_default_conf_file();
    if (fn && file_status(fn) == FN_FILE) {
      fname = fn;
    } else {
      tor_free(fn);
#ifndef MS_WINDOWS
      fn = expand_filename("~/.torrc");
      if (fn && file_status(fn) == FN_FILE) {
        fname = fn;
      } else {
        tor_free(fn);
        fname = get_default_conf_file();
      }
#else
      fname = get_default_conf_file();
#endif
    }
  }
  tor_assert(fname);
  log(LOG_DEBUG, "Opening config file '%s'", fname);

  if (file_status(fname) != FN_FILE ||
      !(cf = read_file_to_str(fname,0))) {
    if (using_default_torrc == 1) {
      log(LOG_NOTICE, "Configuration file '%s' not present, "
          "using reasonable defaults.", fname);
      tor_free(fname); /* sets fname to NULL */
    } else {
      log(LOG_WARN, "Unable to open configuration file '%s'.", fname);
      tor_free(fname);
      goto err;
    }
  } else { /* it opened successfully. use it. */
    retval = config_get_lines(cf, &cl);
    tor_free(cf);
    if (retval < 0)
      goto err;
    retval = config_assign(newoptions, cl, 0);
    config_free_lines(cl);
    if (retval < 0)
      goto err;
  }

  /* Go through command-line variables too */
  cl = config_get_commandlines(argc,argv);
  retval = config_assign(newoptions,cl,0);
  config_free_lines(cl);
  if (retval < 0)
    goto err;

  /* Validate newoptions */
  if (options_validate(newoptions) < 0)
    goto err;

  if (options_transition_allowed(oldoptions, newoptions) < 0)
    goto err;

  set_options(newoptions); /* frees and replaces old options */
  if (options_act() < 0) { /* acting on them failed. die. */
    log_fn(LOG_ERR,"Acting on config options left us in a broken state. Dying.");
    exit(1);
  }
  tor_free(config_fname);
  config_fname = fname;
  return 0;
 err:
  tor_free(fname);
  options_free(newoptions);
  return -1;
}

/** If <b>range</b> is of the form MIN-MAX, for MIN and MAX both
 * recognized log severity levels, set *<b>min_out</b> to MIN and
 * *<b>max_out</b> to MAX and return 0.  Else, if <b>range<b> is of
 * the form MIN, act as if MIN-err had been specified.  Else, warn and
 * return -1.
 */
static int
parse_log_severity_range(const char *range, int *min_out, int *max_out)
{
  int levelMin, levelMax;
  const char *cp;
  cp = strchr(range, '-');
  if (cp) {
    if (cp == range) {
      levelMin = LOG_DEBUG;
    } else {
      char *tmp_sev = tor_strndup(range, cp - range);
      levelMin = parse_log_level(tmp_sev);
      if (levelMin < 0) {
        log_fn(LOG_WARN, "Unrecognized log severity '%s': must be one of "
               "err|warn|notice|info|debug", tmp_sev);
        tor_free(tmp_sev);
        return -1;
      }
      tor_free(tmp_sev);
    }
    if (!*(cp+1)) {
      levelMax = LOG_ERR;
    } else {
      levelMax = parse_log_level(cp+1);
      if (levelMax < 0) {
        log_fn(LOG_WARN, "Unrecognized log severity '%s': must be one of "
               "err|warn|notice|info|debug", cp+1);
        return -1;
      }
    }
  } else {
    levelMin = parse_log_level(range);
    if (levelMin < 0) {
      log_fn(LOG_WARN, "Unrecognized log severity '%s': must be one of "
             "err|warn|notice|info|debug", range);
      return -1;
    }
    levelMax = LOG_ERR;
  }

  *min_out = levelMin;
  *max_out = levelMax;

  return 0;
}

/** Try to convert a pair of old-style logging options [LogLevel, and
 * (LogFile/Syslog)] to a new-style option, and add the new option to
 * options->Logs. */
static int
convert_log_option(or_options_t *options, struct config_line_t *level_opt,
                   struct config_line_t *file_opt, int isDaemon)
{
  int levelMin = -1, levelMax = -1;

  if (level_opt) {
    if (parse_log_severity_range(level_opt->value, &levelMin, &levelMax))
      return -1;
  }
  if (levelMin < 0 && levelMax < 0) {
    levelMin = LOG_NOTICE;
    levelMax = LOG_ERR;
  } else if (levelMin < 0) {
    levelMin = levelMax;
  } else {
    levelMax = LOG_ERR;
  }

  if (file_opt && !strcasecmp(file_opt->key, "LogFile")) {
    if (add_single_log_option(options, levelMin, levelMax, "file", file_opt->value) < 0) {
      log_fn(LOG_WARN, "Cannot write to LogFile '%s': %s.", file_opt->value,
             strerror(errno));
      return -1;
    }
  } else if (file_opt && !strcasecmp(file_opt->key, "SysLog")) {
    if (add_single_log_option(options, levelMin, levelMax, "syslog", NULL) < 0)
      return -1;
  } else if (!isDaemon) {
    add_single_log_option(options, levelMin, levelMax, "stdout", NULL);
  }
  return 0;
}

/**
 * Initialize the logs based on the configuration file.
 */
int
config_init_logs(or_options_t *options, int validate_only)
{
  struct config_line_t *opt;
  int ok;
  smartlist_t *elts;

  ok = 1;
  elts = smartlist_create();
  for (opt = options->Logs; opt; opt = opt->next) {
    int levelMin=LOG_DEBUG, levelMax=LOG_ERR;
    smartlist_split_string(elts, opt->value, NULL,
                           SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 3);
    if (smartlist_len(elts) == 0) {
      log_fn(LOG_WARN, "Bad syntax on Log option 'Log %s'", opt->value);
      ok = 0; goto cleanup;
    }
    if (parse_log_severity_range(smartlist_get(elts,0), &levelMin, &levelMax)) {
      ok = 0; goto cleanup;
    }
    if (smartlist_len(elts) < 2) { /* only loglevels were provided */
      if (!validate_only)
        add_stream_log(levelMin, levelMax, "<stdout>", stdout);
      goto cleanup;
    }
    if (!strcasecmp(smartlist_get(elts,1), "file")) {
      if (smartlist_len(elts) != 3) {
        log_fn(LOG_WARN, "Bad syntax on Log option 'Log %s'", opt->value);
        ok = 0; goto cleanup;
      }
      if (!validate_only)
        add_file_log(levelMin, levelMax, smartlist_get(elts, 2));
      goto cleanup;
    }
    if (smartlist_len(elts) != 2) {
      log_fn(LOG_WARN, "Bad syntax on Log option 'Log %s'", opt->value);
      ok = 0; goto cleanup;
    }
    if (!strcasecmp(smartlist_get(elts,1), "stdout")) {
      if (!validate_only) {
        add_stream_log(levelMin, levelMax, "<stdout>", stdout);
        close_temp_logs();
      }
    } else if (!strcasecmp(smartlist_get(elts,1), "stderr")) {
      if (!validate_only) {
        add_stream_log(levelMin, levelMax, "<stderr>", stderr);
        close_temp_logs();
      }
    } else if (!strcasecmp(smartlist_get(elts,1), "syslog")) {
#ifdef HAVE_SYSLOG_H
      if (!validate_only)
        add_syslog_log(levelMin, levelMax);
#else
      log_fn(LOG_WARN, "Syslog is not supported in this compilation.");
#endif
    } else {
      log_fn(LOG_WARN, "Unrecognized log type %s",
             (const char*)smartlist_get(elts,1));
      if (strchr(smartlist_get(elts,1), '/')) {
        log_fn(LOG_WARN, "Did you mean to say 'Log file %s' ?",
               (const char *)smartlist_get(elts,1));
      }
      ok = 0; goto cleanup;
    }
  cleanup:
    SMARTLIST_FOREACH(elts, char*, cp, tor_free(cp));
    smartlist_clear(elts);
  }
  smartlist_free(elts);
  if (!validate_only)
    close_temp_logs();

  return ok?0:-1;
}

/** Add a single option of the form Log min-max <type> [fname] to options. */
static int
add_single_log_option(or_options_t *options, int minSeverity, int maxSeverity,
                      const char *type, const char *fname)
{
  char buf[512];
  int n;

  n = tor_snprintf(buf, sizeof(buf), "%s%s%s %s%s%s",
                   log_level_to_string(minSeverity),
                   maxSeverity == LOG_ERR ? "" : "-",
                   maxSeverity == LOG_ERR ? "" : log_level_to_string(maxSeverity),
                   type, fname?" ":"", fname?fname:"");
  if (n<0) {
    log_fn(LOG_WARN, "Normalized log option too long.");
    return -1;
  }

  log(LOG_WARN, "The old LogLevel/LogFile/DebugLogFile/SysLog options are deprecated, and will go away soon.  Your new torrc line should be: 'Log %s'", buf);
  config_line_append(&options->Logs, "Log", buf);
  return 0;
}

/** Convert all old-style logging options to new-style Log options. Return 0
 * on success, -1 on failure. */
static int
normalize_log_options(or_options_t *options)
{
  /* The order of options is:  Level? (File Level?)+
   */
  struct config_line_t *opt = options->OldLogOptions;

  /* Special case for if first option is LogLevel. */
  if (opt && !strcasecmp(opt->key, "LogLevel")) {
    if (opt->next && (!strcasecmp(opt->next->key, "LogFile") ||
                      !strcasecmp(opt->next->key, "SysLog"))) {
      if (convert_log_option(options, opt, opt->next, options->RunAsDaemon) < 0)
        return -1;
      opt = opt->next->next;
    } else if (!opt->next) {
      if (convert_log_option(options, opt, NULL, options->RunAsDaemon) < 0)
        return -1;
      opt = opt->next;
    } else {
      ; /* give warning below */
    }
  }

  while (opt) {
    if (!strcasecmp(opt->key, "LogLevel")) {
      log_fn(LOG_WARN, "Two LogLevel options in a row without intervening LogFile or SysLog");
      opt = opt->next;
    } else {
      tor_assert(!strcasecmp(opt->key, "LogFile") ||
                 !strcasecmp(opt->key, "SysLog"));
      if (opt->next && !strcasecmp(opt->next->key, "LogLevel")) {
        /* LogFile/SysLog followed by LogLevel */
        if (convert_log_option(options,opt->next,opt, options->RunAsDaemon) < 0)
          return -1;
        opt = opt->next->next;
      } else {
        /* LogFile/SysLog followed by LogFile/SysLog or end of list. */
        if (convert_log_option(options,NULL, opt, options->RunAsDaemon) < 0)
          return -1;
        opt = opt->next;
      }
    }
  }

  if (options->DebugLogFile) {
    if (add_single_log_option(options, LOG_DEBUG, LOG_ERR, "file", options->DebugLogFile) < 0)
      return -1;
  }

  tor_free(options->DebugLogFile);
  config_free_lines(options->OldLogOptions);
  options->OldLogOptions = NULL;

  return 0;
}

/**
 * Given a linked list of config lines containing "allow" and "deny" tokens,
 * parse them and append the result to <b>dest</b>.  Return -1 if any tokens
 * are malformed, else return 0.
 */
int
config_parse_addr_policy(struct config_line_t *cfg,
                         addr_policy_t **dest)
{
  addr_policy_t **nextp;
  smartlist_t *entries;
  int r = 0;

  if (!cfg)
    return 0;

  nextp = dest;

  while (*nextp)
    nextp = &((*nextp)->next);

  entries = smartlist_create();
  for (; cfg; cfg = cfg->next) {
    smartlist_split_string(entries, cfg->value, ",", SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
    SMARTLIST_FOREACH(entries, const char *, ent,
    {
      log_fn(LOG_DEBUG,"Adding new entry '%s'",ent);
      *nextp = router_parse_addr_policy_from_string(ent);
      if (*nextp) {
        nextp = &((*nextp)->next);
      } else {
        log_fn(LOG_WARN,"Malformed policy %s.", ent);
        r = -1;
      }
    });
    SMARTLIST_FOREACH(entries, char *, ent, tor_free(ent));
    smartlist_clear(entries);
  }
  smartlist_free(entries);
  return r;
}

/** Release all storage held by <b>p</b> */
void
addr_policy_free(addr_policy_t *p) {
  addr_policy_t *e;

  while (p) {
    e = p;
    p = p->next;
    tor_free(e->string);
    tor_free(e);
  }
}

/** Parse a single RedirectExit line's contents from <b>line</b>.  If
 *  they are valid, and <b>result</b> is not NULL, add an element to
 *  <b>result</b> and return 0. Else if they are valid, return 0.
 *  Else return -1. */
static int
parse_redirect_line(smartlist_t *result, struct config_line_t *line)
{
  smartlist_t *elements = NULL;
  exit_redirect_t *r;

  tor_assert(line);

  r = tor_malloc_zero(sizeof(exit_redirect_t));
  elements = smartlist_create();
  smartlist_split_string(elements, line->value, NULL,
                         SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
  if (smartlist_len(elements) != 2) {
    log_fn(LOG_WARN, "Wrong number of elements in RedirectExit line");
    goto err;
  }
  if (parse_addr_and_port_range(smartlist_get(elements,0),&r->addr,&r->mask,
                                &r->port_min,&r->port_max)) {
    log_fn(LOG_WARN, "Error parsing source address in RedirectExit line");
    goto err;
  }
  if (0==strcasecmp(smartlist_get(elements,1), "pass")) {
    r->is_redirect = 0;
  } else {
    if (parse_addr_port(smartlist_get(elements,1),NULL,&r->addr_dest,
                             &r->port_dest)) {
      log_fn(LOG_WARN, "Error parsing dest address in RedirectExit line");
      goto err;
    }
    r->is_redirect = 1;
  }

  goto done;
 err:
  tor_free(r);
 done:
  SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp));
  smartlist_free(elements);
  if (r) {
    if (result)
      smartlist_add(result, r);
    else
      tor_free(r);
    return 0;
  } else {
    return -1;
  }
}

/** Read the contents of a DirServer line from <b>line</b>.  Return 0
 * if the line is well-formed, and 0 if it isn't.  If
 * <b>validate_only</b> is 0, and the line is well-formed, then add
 * the dirserver described in the line as a valid server. */
static int
parse_dir_server_line(const char *line, int validate_only)
{
  smartlist_t *items = NULL;
  int r;
  char *addrport, *address=NULL;
  uint16_t port;
  char digest[DIGEST_LEN];

  items = smartlist_create();
  smartlist_split_string(items, line, NULL,
                         SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 2);
  if (smartlist_len(items) < 2) {
    log_fn(LOG_WARN, "Too few arguments to DirServer line.");
    goto err;
  }
  addrport = smartlist_get(items, 0);
  if (parse_addr_port(addrport, &address, NULL, &port)<0) {
    log_fn(LOG_WARN, "Error parsing DirServer address '%s'", addrport);
    goto err;
  }
  if (!port) {
    log_fn(LOG_WARN, "Missing port in DirServer address '%s'",addrport);
    goto err;
  }

  tor_strstrip(smartlist_get(items, 1), " ");
  if (strlen(smartlist_get(items, 1)) != HEX_DIGEST_LEN) {
    log_fn(LOG_WARN, "Key digest for DirServer is wrong length.");
    goto err;
  }
  if (base16_decode(digest, DIGEST_LEN,
                    smartlist_get(items,1), HEX_DIGEST_LEN)<0) {
    log_fn(LOG_WARN, "Unable to decode DirServer key digest.");
    goto err;
  }

  if (!validate_only) {
    log_fn(LOG_DEBUG, "Trusted dirserver at %s:%d (%s)", address, (int)port,
           (char*)smartlist_get(items,1));
    add_trusted_dir_server(address, port, digest);
  }

  r = 0;
  goto done;

  err:
  r = -1;

  done:
  SMARTLIST_FOREACH(items, char*, s, tor_free(s));
  smartlist_free(items);
  tor_free(address);
  return r;
}

/** Adjust the value of options->DataDirectory, or fill it in if it's
 * absent. Return 0 on success, -1 on failure. */
static int
normalize_data_directory(or_options_t *options) {
#ifdef MS_WINDOWS
  char *p;
  if (options->DataDirectory)
    return 0; /* all set */
  p = tor_malloc(MAX_PATH);
  strlcpy(p,get_windows_conf_root(),MAX_PATH);
  options->DataDirectory = p;
  return 0;
#else
  const char *d = options->DataDirectory;
  if (!d)
    d = "~/.tor";

 if (strncmp(d,"~/",2) == 0) {
   char *fn = expand_filename(d);
   if (!fn) {
     log_fn(LOG_ERR,"Failed to expand filename '%s'.", d);
     return -1;
   }
   if (!options->DataDirectory && !strcmp(fn,"/.tor")) {
     /* If our homedir is /, we probably don't want to use it. */
     /* XXXX Default to /var/lib/tor? */
     log_fn(LOG_WARN, "Defaulting to 'DataDirectory %s', which may not be what you want", fn);
   }
   tor_free(options->DataDirectory);
   options->DataDirectory = fn;
 }
 return 0;
#endif
}

/** Check and normalize the value of options->DataDirectory; return 0 if it
 * sane, -1 otherwise. */
static int
validate_data_directory(or_options_t *options) {
  if (normalize_data_directory(options) < 0)
    return -1;
  tor_assert(options->DataDirectory);
  if (strlen(options->DataDirectory) > (512-128)) {
    log_fn(LOG_ERR, "DataDirectory is too long.");
    return -1;
  }
#if 0
  if (check_private_dir(options->DataDirectory, CPD_CHECK != 0)) {
    log_fn(LOG_WARN, "Can't create directory %s", options->DataDirectory);
    return -1;
  }
#endif
  return 0;
}

#define GENERATED_FILE_PREFIX "# This file was generated by Tor; if you edit it, comments will not be preserved"

/** Save a configuration file for the configuration in <b>options</b>
 * into the file <b>fname</b>.  If the file already exists, and
 * doesn't begin with GENERATED_FILE_PREFIX, rename it.  Otherwise
 * replace it.  Return 0 on success, -1 on failure. */
static int
write_configuration_file(const char *fname, or_options_t *options)
{
  char fn_tmp[1024];
  char *old_val=NULL, *new_val=NULL, *new_conf=NULL;
  int rename_old = 0, r;
  size_t len;

  if (fname) {
    switch (file_status(fname)) {
      case FN_FILE:
        old_val = read_file_to_str(fname, 0);
        if (strcmpstart(old_val, GENERATED_FILE_PREFIX)) {
          rename_old = 1;
        }
        tor_free(old_val);
        break;
      case FN_NOENT:
        break;
      default:
        log_fn(LOG_WARN,"Config file %s is not a file? Failing.", fname);
        return -1;
    }
  }

  if (!(new_conf = config_dump_options(options, 1))) {
    log_fn(LOG_WARN, "Couldn't get configuration string");
    goto err;
  }

  len = strlen(new_conf)+128;
  new_val = tor_malloc(len);
  tor_snprintf(new_val, len, "%s\n\n%s", GENERATED_FILE_PREFIX, new_conf);

  if (rename_old) {
    int i = 1;
    while (1) {
      if (tor_snprintf(fn_tmp, sizeof(fn_tmp), "%s.orig.%d", fname, i)<0) {
        log_fn(LOG_WARN, "Filename too long");
        goto err;
      }
      if (file_status(fn_tmp) == FN_NOENT)
        break;
      ++i;
    }
    log_fn(LOG_NOTICE, "Renaming old configuration file to %s", fn_tmp);
    rename(fname, fn_tmp);
  }

  write_str_to_file(fname, new_val, 0);

  r = 0;
  goto done;
 err:
  r = -1;
 done:
  tor_free(new_val);
  tor_free(new_conf);
  return r;
}

/**
 * Save the current configuration file value to disk.  Return 0 on
 * success, -1 on failure.
 **/
int
save_current_config(void)
{
  char *fn;
  if (config_fname) {
    /* XXX This fails if we can't write to our configuration file.
     *   Arguably, we should try falling back to datadirectory or something.
     *   But just as arguably, we shouldn't. */
    return write_configuration_file(config_fname, get_options());
  }
  fn = get_default_conf_file();
  return write_configuration_file(fn, get_options());
}

struct unit_table_t {
  const char *unit;
  uint64_t multiplier;
};

static struct unit_table_t memory_units[] = {
  { "",          1 },
  { "b",         1<< 0 },
  { "byte",      1<< 0 },
  { "bytes",     1<< 0 },
  { "kb",        1<<10 },
  { "kilobyte",  1<<10 },
  { "kilobytes", 1<<10 },
  { "m",         1<<20 },
  { "mb",        1<<20 },
  { "megabyte",  1<<20 },
  { "megabytes", 1<<20 },
  { "gb",        1<<30 },
  { "gigabyte",  1<<30 },
  { "gigabytes", 1<<30 },
  { "tb",        U64_LITERAL(1)<<40 },
  { "terabyte",  U64_LITERAL(1)<<40 },
  { "terabytes", U64_LITERAL(1)<<40 },
  { NULL, 0 },
};

static struct unit_table_t time_units[] = {
  { "",         1 },
  { "second",   1 },
  { "seconds",  1 },
  { "minute",   60 },
  { "minutes",  60 },
  { "hour",     60*60 },
  { "hours",    60*60 },
  { "day",      24*60*60 },
  { "days",     24*60*60 },
  { "week",     7*24*60*60 },
  { "weeks",    7*24*60*60 },
  { NULL, 0 },
};

/** Parse a string <b>val</b> containing a number, zero or more
 * spaces, and an optional unit string.  If the unit appears in the
 * table <b>u</b>, then multiply the number by the unit multiplier.
 * On success, set *<b>ok</b> to 1 and return this product.
 * Otherwise, set *<b>ok</b> to 0.
 */
static uint64_t
config_parse_units(const char *val, struct unit_table_t *u, int *ok)
{
  uint64_t v;
  char *cp;

  tor_assert(ok);

  v = tor_parse_uint64(val, 10, 0, UINT64_MAX, ok, &cp);
  if (!*ok)
    return 0;
  if (!cp) {
    *ok = 1;
    return v;
  }
  while (TOR_ISSPACE(*cp))
    ++cp;
  for ( ;u->unit;++u) {
    if (!strcasecmp(u->unit, cp)) {
      v *= u->multiplier;
      *ok = 1;
      return v;
    }
  }
  log_fn(LOG_WARN, "Unknown unit '%s'.", cp);
  *ok = 0;
  return 0;
}

/** Parse a string in the format "number unit", where unit is a unit of
 * information (byte, KB, M, etc).  On success, set *<b>ok</b> to true
 * and return the number of bytes specified.  Otherwise, set
 * *<b>ok</b> to false and return 0. */
static uint64_t
config_parse_memunit(const char *s, int *ok) {
  return config_parse_units(s, memory_units, ok);
}

/** Parse a string in the format "number unit", where unit is a unit of time.
 * On success, set *<b>ok</b> to true and return the number of seconds in
 * the provided interval.  Otherwise, set *<b>ok</b> to 0 and return -1.
 */
static int
config_parse_interval(const char *s, int *ok) {
  uint64_t r;
  r = config_parse_units(s, time_units, ok);
  if (!ok)
    return -1;
  if (r > INT_MAX) {
    log_fn(LOG_WARN, "Interval '%s' is too long", s);
    *ok = 0;
    return -1;
  }
  return (int)r;
}

static void
print_cvs_version(void)
{
  extern const char aes_c_id[];
  extern const char compat_c_id[];
  extern const char container_c_id[];
  extern const char crypto_c_id[];
  extern const char log_c_id[];
  extern const char torgzip_c_id[];
  extern const char tortls_c_id[];
  extern const char util_c_id[];

  extern const char buffers_c_id[];
  extern const char circuitbuild_c_id[];
  extern const char circuitlist_c_id[];
  extern const char circuituse_c_id[];
  extern const char command_c_id[];
//  extern const char config_c_id[];
  extern const char connection_c_id[];
  extern const char connection_edge_c_id[];
  extern const char connection_or_c_id[];
  extern const char control_c_id[];
  extern const char cpuworker_c_id[];
  extern const char directory_c_id[];
  extern const char dirserv_c_id[];
  extern const char dns_c_id[];
  extern const char hibernate_c_id[];
  extern const char main_c_id[];
  extern const char onion_c_id[];
  extern const char relay_c_id[];
  extern const char rendclient_c_id[];
  extern const char rendcommon_c_id[];
  extern const char rendmid_c_id[];
  extern const char rendservice_c_id[];
  extern const char rephist_c_id[];
  extern const char router_c_id[];
  extern const char routerlist_c_id[];
  extern const char routerparse_c_id[];

  puts(AES_H_ID);
  puts(COMPAT_H_ID);
  puts(CONTAINER_H_ID);
  puts(CRYPTO_H_ID);
  puts(LOG_H_ID);
  puts(TORGZIP_H_ID);
  puts(TORINT_H_ID);
  puts(TORTLS_H_ID);
  puts(UTIL_H_ID);
  puts(aes_c_id);
  puts(compat_c_id);
  puts(container_c_id);
  puts(crypto_c_id);
  puts(log_c_id);
  puts(torgzip_c_id);
  puts(tortls_c_id);
  puts(util_c_id);

  puts(OR_H_ID);
  puts(buffers_c_id);
  puts(circuitbuild_c_id);
  puts(circuitlist_c_id);
  puts(circuituse_c_id);
  puts(command_c_id);
  puts(config_c_id);
  puts(connection_c_id);
  puts(connection_edge_c_id);
  puts(connection_or_c_id);
  puts(control_c_id);
  puts(cpuworker_c_id);
  puts(directory_c_id);
  puts(dirserv_c_id);
  puts(dns_c_id);
  puts(hibernate_c_id);
  puts(main_c_id);
  puts(onion_c_id);
  puts(relay_c_id);
  puts(rendclient_c_id);
  puts(rendcommon_c_id);
  puts(rendmid_c_id);
  puts(rendservice_c_id);
  puts(rephist_c_id);
  puts(router_c_id);
  puts(routerlist_c_id);
  puts(routerparse_c_id);
}