Commit e847085c authored by Roger Dingledine's avatar Roger Dingledine
Browse files

When a client asks for an old-style directory and our write bucket 

is empty, don't give it to him. This way small servers can continue
to serve the directory *sometimes*, without getting overloaded.


svn:r5968
parent 484a3f3d

src/or/connection.c

+7 −0
Original line number Diff line number Diff line
@@ -1036,6 +1036,13 @@ connection_bucket_write_limit(connection_t *conn) 
  return at_most;

}



/** Return 1 if the global write bucket has no bytes in it,

 * or return 0 if it does. */

int global_write_bucket_empty(void)

{

  return global_write_bucket <= 0;

}



/** We just read num_read onto conn. Decrement buckets appropriately. */

static void

connection_read_bucket_decrement(connection_t *conn, int num_read)

src/or/directory.c

+12 −4
Original line number Diff line number Diff line
@@ -1387,10 +1387,6 @@ directory_handle_command_get(connection_t *conn, char *headers, 
    int deflated = !strcmp(url,"/tor/dir.z");

    dlen = dirserv_get_directory(&cp, deflated);



    note_request(url, dlen);



    tor_free(url);



    if (dlen == 0) {

      notice(LD_DIRSERV,"Client asked for the mirrored directory, but we "

             "don't have a good one yet. Sending 503 Dir not available.");
@@ -1398,9 +1394,21 @@ directory_handle_command_get(connection_t *conn, char *headers, 
      /* try to get a new one now */

      if (!already_fetching_directory(DIR_PURPOSE_FETCH_DIR))

        directory_get_from_dirserver(DIR_PURPOSE_FETCH_DIR, NULL, 1);

      tor_free(url);

      return 0;

    }



    if (global_write_bucket_empty()) {

      info(LD_DIRSERV,

           "Client asked for the mirrored directory, but we've been "

           "writing too many bytes lately. Sending 503 Dir busy.");

      write_http_status_line(conn, 503, "Directory busy, try again later");

      tor_free(url);

      return 0;

    }



    note_request(url, dlen);



    debug(LD_DIRSERV,"Dumping %sdirectory to client.",

          deflated?"deflated ":"");

    format_rfc1123_time(date, time(NULL));

src/or/or.h

+1 −0
Original line number Diff line number Diff line
@@ -1635,6 +1635,7 @@ int retry_all_listeners(int force, smartlist_t *replaced_conns, 
                        smartlist_t *new_conns);



int connection_bucket_write_limit(connection_t *conn);

int global_write_bucket_empty(void);

void connection_bucket_init(void);

void connection_bucket_refill(struct timeval *now);