/*      $NetBSD: in_offload.h,v 1.12 2018/12/12 01:40:20 rin Exp $      */

/*
* Copyright (c)2005, 2006 YAMAMOTO Takashi,
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef _NETINET_IN_OFFLOAD_H_
#define _NETINET_IN_OFFLOAD_H_

/*
* Subroutines to do software-only equivalent of h/w offloading.
*/
struct mbuf *tcp4_segment(struct mbuf *, int);
int ip_tso_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
   struct rtentry *);
void in_undefer_cksum(struct mbuf *, size_t, int);
void in_undefer_cksum_tcpudp(struct mbuf *);

/*
* Offloading-related sysctl variables.
*
* They are here because it violates protocol layering in unusual way.
* ie. while they are TCP/UDP sysctls, they are used by IP layer.
*/
extern int tcp_do_loopback_cksum; /* do TCP checksum on loopback? */
extern int udp_do_loopback_cksum; /* do UDP checksum on loopback? */

#define IN_LOOPBACK_NEED_CHECKSUM(csum_flags) \
       ((((csum_flags) & M_CSUM_UDPv4) != 0 && udp_do_loopback_cksum) || \
       (((csum_flags) & M_CSUM_TCPv4) != 0 && tcp_do_loopback_cksum) || \
       (((csum_flags) & M_CSUM_IPv4) != 0 && ip_do_loopback_cksum))

#define IN_NEED_CHECKSUM(ifp, csum_flags) \
       (__predict_true(((ifp)->if_flags & IFF_LOOPBACK) == 0 || \
       IN_LOOPBACK_NEED_CHECKSUM(csum_flags)))

#endif /* !_NETINET_IN_OFFLOAD_H_ */