Commit 5d41346b authored by Roger Dingledine's avatar Roger Dingledine
Browse files

prevent servers from publishing an internal IP as their address 


svn:r1272
parent f55ff5b8

src/or/config.c

+45 −33
Original line number Diff line number Diff line
@@ -345,6 +345,49 @@ static void print_usage(void) { 
         );

}



int resolve_my_address(or_options_t *options) {

  struct in_addr in;

  struct hostent *rent;

  char localhostname[256];



  if(!options->Address) { /* then we need to guess our address */



    if(gethostname(localhostname,sizeof(localhostname)) < 0) {

      log_fn(LOG_WARN,"Error obtaining local hostname");

      return -1;

    }

#if 0 /* don't worry about complaining, as long as it resolves */

    if(!strchr(localhostname,'.')) {

      log_fn(LOG_WARN,"fqdn '%s' has only one element. Misconfigured machine?",address);

      log_fn(LOG_WARN,"Try setting the Address line in your config file.");

      return -1;

    }

#endif

    options->Address = tor_strdup(localhostname);

    log_fn(LOG_DEBUG,"Guessed local host name as '%s'",options->Address);

  }



  /* now we know options->Address is set. resolve it and keep only the IP */



  rent = (struct hostent *)gethostbyname(options->Address);

  if (!rent) {

    log_fn(LOG_WARN,"Could not resolve Address %s. Failing.", options->Address);

    return -1;

  }

  assert(rent->h_length == 4);

  memcpy(&in.s_addr, rent->h_addr,rent->h_length);

  if(is_internal_IP(in.s_addr)) {

    log_fn(LOG_WARN,"Address '%s' resolves to '%s'. "

           "Please set the Address config option to be your public IP.",

           options->Address, inet_ntoa(in));

    return -1;

  }

  tor_free(options->Address);

  options->Address = tor_strdup(inet_ntoa(in));

  log_fn(LOG_DEBUG,"Resolved Address to %s.", options->Address);

  return 0;

}



static void free_options(or_options_t *options) {

  tor_free(options->LogLevel);

  tor_free(options->LogFile);
@@ -525,39 +568,8 @@ int getconfig(int argc, char **argv, or_options_t *options) { 
  }



  if(options->ORPort) { /* get an IP for ourselves */

    struct in_addr in;

    struct hostent *rent;

    char localhostname[256];



    if(!options->Address) { /* then we need to guess our address */



      if(gethostname(localhostname,sizeof(localhostname)) < 0) {

        log_fn(LOG_WARN,"Error obtaining local hostname");

        return -1;

      }

#if 0 /* don't worry about complaining, as long as it resolves */

      if(!strchr(localhostname,'.')) {

        log_fn(LOG_WARN,"fqdn '%s' has only one element. Misconfigured machine?",address);

        log_fn(LOG_WARN,"Try setting the Address line in your config file.");

        return -1;

      }

#endif

      options->Address = tor_strdup(localhostname);

      log_fn(LOG_DEBUG,"Guessed local host name as '%s'",options->Address);

    }



    /* now we know options->Address is set. resolve it and keep only the IP */



    rent = (struct hostent *)gethostbyname(options->Address);

    if (!rent) {

      log_fn(LOG_WARN,"Could not resolve Address %s. Failing.", options->Address);

      return -1;

    }

    assert(rent->h_length == 4);

    memcpy(&in.s_addr, rent->h_addr,rent->h_length);

    tor_free(options->Address);

    options->Address = tor_strdup(inet_ntoa(in));

    log_fn(LOG_DEBUG,"Resolved Address to %s.", options->Address);

    if(resolve_my_address(options) < 0)

      result = -1;

  }



  if(options->SocksPort < 0) {