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 gnutls_transport_set_fastopen(3)  gnutls   gnutls_transport_set_fastopen(3)
 gnutls                                                               gnutls

                                    3.6.6



 NAME
      gnutls_transport_set_fastopen - API function

 SYNOPSIS
      #include <gnutls/socket.h>

      void gnutls_transport_set_fastopen(gnutls_session_t session, int fd,
      struct sockaddr * connect_addr

 ARGUMENTS
      gnutls_session_t session
                  is a gnutls_session_t type.

      int fd      is the session's socket descriptor

      struct sockaddr * connect_addr
                  is the address we want to connect to

      socklen_t connect_addrlen
                  is the length of  connect_addr

      unsigned int flags
                  must be zero

 DESCRIPTION
      Enables TCP Fast Open (TFO) for the specified TLS client session.
      That means that TCP connection establishment and the transmission of
      the first TLS client hello packet are combined. The peer's address
      must be  specified in  connect_addr and  connect_addrlen , and the
      socket specified by  fd should not be connected.

      TFO only works for TCP sockets of type AF_INET and AF_INET6.  If the
      OS doesn't support TCP fast open this function will result to gnutls
      using connect() transparently during the first write.

 NOTE
      This function overrides all the transport callback functions.  If this
      is undesirable, TCP Fast Open must be implemented on the user callback
      functions without calling this function. When using this function,
      transport callbacks must not be set, and gnutls_transport_set_ptr() or
      gnutls_transport_set_int() must not be called.

      On GNU/Linux TFO has to be enabled at the system layer, that is in
      /proc/sys/net/ipv4/tcp_fastopen, bit 0 has to be set.

      This function has no effect on server sessions.

 SINCE
      3.5.3



                                    - 1 -      Formatted:  February 25, 2020






 gnutls_transport_set_fastopen(3)  gnutls   gnutls_transport_set_fastopen(3)
 gnutls                                                               gnutls

                                    3.6.6



 REPORTING BUGS
      Report bugs to <bugs@gnutls.org>.
      Home page: http://www.gnutls.org


 COPYRIGHT
      Copyright c 2001-2020 Free Software Foundation, Inc., and others.
      Copying and distribution of this file, with or without modification,
      are permitted in any medium without royalty provided the copyright
      notice and this notice are preserved.

 SEE ALSO
      The full documentation for gnutls is maintained as a Texinfo manual.
      If the /usr/share/doc/gnutls/ directory does not contain the HTML form
      visit

      http://www.gnutls.org/manual/
































                                    - 2 -      Formatted:  February 25, 2020