Commit aba7bb70 authored by Nick Mathewson's avatar Nick Mathewson 🐘
Browse files

Set SO_REUSEADDR on all sockets, not just listeners 

See bug 2850 for rationale: it appears that on some busy exits, the OS
decides that every single port is now unusable because they have been
all used too recently.
parent 4126de68

changes/bug2850

0 → 100644
+5 −0
Changes for changes/bug2850: 5 added lines, 0 removed lines.
Original line number Diff line number Diff line 
  - Minor features

    o Set SO_REUSEADDR on all sockets, not just listeners.  This should

      help busy exit nodes avoid running out of useable ports just because

      all the ports have been used in the near past.  Resolves issue 2850.

src/or/connection.c

+23 −11
Changes for src/or/connection.c: 23 added lines, 11 removed lines.
Original line number Diff line number Diff line
@@ -851,6 +851,25 @@ warn_too_many_conns(void) 
  }

}



/** Tell the TCP stack that it shouldn't wait for a long time after

 * <b>sock</b> has closed before reusing its port. */

static void

make_socket_reuseable(int sock)

{

#ifdef MS_WINDOWS

  (void) sock;

#else

  int one=1;



  /* REUSEADDR on normal places means you can rebind to the port

   * right after somebody else has let it go. But REUSEADDR on win32

   * means you can bind to the port _even when somebody else

   * already has it bound_. So, don't do that on Win32. */

  setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &one,

             (socklen_t)sizeof(one));

#endif

}



/** Bind a new non-blocking socket listening to the socket described

 * by <b>listensockaddr</b>.

 *
@@ -873,9 +892,6 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen, 


  if (listensockaddr->sa_family == AF_INET) {

    int is_tcp = (type != CONN_TYPE_AP_DNS_LISTENER);

#ifndef MS_WINDOWS

    int one=1;

#endif

    if (is_tcp)

      start_reading = 1;
@@ -893,14 +909,7 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen, 
      goto err;

    }



#ifndef MS_WINDOWS

    /* REUSEADDR on normal places means you can rebind to the port

     * right after somebody else has let it go. But REUSEADDR on win32

     * means you can bind to the port _even when somebody else

     * already has it bound_. So, don't do that on Win32. */

    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (void*) &one,

               (socklen_t)sizeof(one));

#endif

    make_socket_reuseable(s);



    if (bind(s,listensockaddr,socklen) < 0) {

      const char *helpfulhint = "";
@@ -1088,6 +1097,7 @@ connection_handle_listener_read(connection_t *conn, int new_type) 
            "Connection accepted on socket %d (child of fd %d).",

            news,conn->s);



  make_socket_reuseable(news);

  set_socket_nonblocking(news);



  if (options->ConstrainedSockets)
@@ -1297,6 +1307,8 @@ connection_connect(connection_t *conn, const char *address, 
  log_debug(LD_NET, "Connecting to %s:%u.",

            escaped_safe_str_client(address), port);



  make_socket_reuseable(s);



  if (connect(s, dest_addr, dest_addr_len) < 0) {

    int e = tor_socket_errno(s);

    if (!ERRNO_IS_CONN_EINPROGRESS(e)) {