/*      $OpenBSD: ip_gre.c,v 1.90 2025/07/08 00:47:41 jsg Exp $ */
/*      $NetBSD: ip_gre.c,v 1.9 1999/10/25 19:18:11 drochner Exp $ */

/*
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Heiko W.Rupp <hwr@pilhuhn.de>
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * decapsulate tunneled packets and send them on
 * output half is in net/if_gre.[ch]
 * This currently handles IPPROTO_GRE, IPPROTO_MOBILE
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>

#include <net/if.h>
#include <net/if_var.h>

#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_gre.h>
#include <netinet/ip_var.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>

#ifdef PIPEX
#include <net/pipex.h>
#endif

const struct pr_usrreqs gre_usrreqs = {
        .pru_attach     = rip_attach,
        .pru_detach     = rip_detach,
        .pru_bind       = rip_bind,
        .pru_connect    = rip_connect,
        .pru_disconnect = rip_disconnect,
        .pru_shutdown   = rip_shutdown,
        .pru_send       = gre_send,
        .pru_control    = in_control,
        .pru_sockaddr   = in_sockaddr,
        .pru_peeraddr   = in_peeraddr,
};

int
gre_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
    struct mbuf *control)
{
#ifdef PIPEX
        struct inpcb *inp = sotoinpcb(so);

        if (inp->inp_pipex) {
                struct sockaddr_in *sin4;
                const struct in_addr *ina_dst;

                ina_dst = NULL;
                if ((so->so_state & SS_ISCONNECTED) != 0)
                        ina_dst = &inp->inp_laddr;
                else if (nam) {
                        if (in_nam2sin(nam, &sin4) == 0)
                                ina_dst = &sin4->sin_addr;
                }
                if (ina_dst != NULL) {
                        struct pipex_session *session;

                        session = pipex_pptp_userland_lookup_session_ipv4(m,
                            *ina_dst);

                        if(session != NULL) {
                                m = pipex_pptp_userland_output(m, session);
                                pipex_rele_session(session);
                        }
                }

                if (m == NULL) {
                        m_freem(control);
                        return (ENOMEM);
                }
        }
#endif
        return rip_send(so, m, nam, control);
}