in6_gif.c

来自「eCos操作系统源码」· C语言 代码 · 共 662 行 · 第 1/2 页

//==========================================================================
//
//      src/sys/netinet6/in6_gif.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

/*	$KAME: in6_gif.c,v 1.88 2001/12/21 03:32:34 itojun Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
 */

/* define it if you want to use encap_attach_func (it helps *BSD merge) */
/*#define USE_ENCAPCHECK*/

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
#include <sys/ioctl.h>
#endif
#include <sys/queue.h>
#include <sys/protosw.h>

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
#include <sys/malloc.h>
#endif

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

#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET
#include <netinet/ip.h>
#endif
#include <netinet/ip_encap.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_gif.h>
#include <netinet6/in6_var.h>
#endif
#include <netinet6/ip6protosw.h>
#include <netinet/ip_ecn.h>
#ifdef __OpenBSD__
#include <netinet/ip_ipsp.h>
#endif

#include <net/if_gif.h>

#ifdef __OpenBSD__
#include "bridge.h"
#endif

static int gif_validate6 __P((const struct ip6_hdr *, struct gif_softc *,
	struct ifnet *));
static int in6_gif_rtcachettl = 300; /* XXX see in_gif.c */

int	ip6_gif_hlim = GIF_HLIM;

extern struct domain inet6domain;
struct ip6protosw in6_gif_protosw =
{ SOCK_RAW,	&inet6domain,	0/* IPPROTO_IPV[46] */,	PR_ATOMIC|PR_ADDR,
  in6_gif_input, rip6_output,	in6_gif_ctlinput, rip6_ctloutput,
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
  0,
#else
  rip6_usrreq,
#endif
  0,            0,              0,              0,
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
  &rip6_usrreqs
#endif
};

extern LIST_HEAD(, gif_softc) gif_softc_list;

#ifndef offsetof
#define offsetof(s, e) ((int)&((s *)0)->e)
#endif

int
in6_gif_output(ifp, family, m)
	struct ifnet *ifp;
	int family; /* family of the packet to be encapsulate. */
	struct mbuf *m;
{
#ifdef __OpenBSD__
	struct gif_softc *sc = (struct gif_softc*)ifp;
        struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
	struct tdb tdb;
	struct xformsw xfs;
	int error;
	int hlen, poff;
	struct mbuf *mp;
	long time_second;

	if (sin6_src == NULL || sin6_dst == NULL ||
	    sin6_src->sin6_family != AF_INET6 ||
	    sin6_dst->sin6_family != AF_INET6) {
		m_freem(m);
		return EAFNOSUPPORT;
	}

	/* setup dummy tdb.  it highly depends on ipip_output() code. */
	bzero(&tdb, sizeof(tdb));
	bzero(&xfs, sizeof(xfs));
	tdb.tdb_src.sin6.sin6_family = AF_INET6;
	tdb.tdb_src.sin6.sin6_len = sizeof(struct sockaddr_in6);
	tdb.tdb_src.sin6.sin6_addr = sin6_src->sin6_addr;
	tdb.tdb_dst.sin6.sin6_family = AF_INET6;
	tdb.tdb_dst.sin6.sin6_len = sizeof(struct sockaddr_in6);
	tdb.tdb_dst.sin6.sin6_addr = sin6_dst->sin6_addr;
	tdb.tdb_xform = &xfs;
	xfs.xf_type = -1;	/* not XF_IP4 */

	switch (family) {
#ifdef INET
	case AF_INET:
	    {
		if (m->m_len < sizeof(struct ip)) {
			m = m_pullup(m, sizeof(struct ip));
			if (!m)
				return ENOBUFS;
		}
		hlen = (mtod(m, struct ip *)->ip_hl) << 2;
		poff = offsetof(struct ip, ip_p);
		break;
	    }
#endif
#ifdef INET6
	case AF_INET6:
	    {
		hlen = sizeof(struct ip6_hdr);
		poff = offsetof(struct ip6_hdr, ip6_nxt);
		break;
	    }
#endif
#if NBRIDGE > 0
	case AF_LINK:
		break;
#endif /* NBRIDGE */
	default:
#ifdef DEBUG
		printf("in6_gif_output: warning: unknown family %d passed\n",
			family);
#endif
		m_freem(m);
		return EAFNOSUPPORT;
	}
	
#if NBRIDGE > 0
	if (family == AF_LINK) {
	        mp = NULL;
		error = etherip_output(m, &tdb, &mp, 0, 0);
		if (error)
		        return error;
		else if (mp == NULL)
		        return EFAULT;

		m = mp;
		goto sendit;
	}
#endif /* NBRIDGE */

	/* encapsulate into IPv6 packet */
	mp = NULL;
	error = ipip_output(m, &tdb, &mp, hlen, poff);
	if (error)
	        return error;
	else if (mp == NULL)
	        return EFAULT;

	m = mp;

#if NBRIDGE > 0
 sendit:
#endif /* NBRIDGE */
	/*
	 * compare address family just for safety.  other validity checks
	 * are made in in6_selectsrc() called from ip6_output().
	 */
	if (sc->gif_ro6.ro_rt && (dst->sin6_family != sin6_dst->sin6_family ||
				  sc->rtcache_expire == 0 ||
				  time_second >= sc->rtcache_expire)) {
		RTFREE(sc->gif_ro6.ro_rt);
		sc->gif_ro6.ro_rt = NULL;
	}

#ifdef IPV6_MINMTU
	/*
	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
	 * it is too painful to ask for resend of inner packet, to achieve
	 * path MTU discovery for encapsulated packets.
	 */
	error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL);
#else
	error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL);
#endif

	if (sc->gif_ro6.ro_rt && time_second >= sc->rtcache_expire)
		sc->rtcache_expire = time_second + in6_gif_rtcachettl;

	return(error);
#else	/* !__OpenBSD__ */
	struct gif_softc *sc = (struct gif_softc*)ifp;
	struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
	struct ip6_hdr *ip6;
	int proto, error;
	u_int8_t itos, otos;
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
	long time_second;
#endif

	if (sin6_src == NULL || sin6_dst == NULL ||
	    sin6_src->sin6_family != AF_INET6 ||
	    sin6_dst->sin6_family != AF_INET6) {
		m_freem(m);
		return EAFNOSUPPORT;
	}

	switch (family) {
#ifdef INET
	case AF_INET:
	    {
		struct ip *ip;

		proto = IPPROTO_IPV4;
		if (m->m_len < sizeof(*ip)) {
			m = m_pullup(m, sizeof(*ip));
			if (!m)
				return ENOBUFS;
		}
		ip = mtod(m, struct ip *);
		itos = ip->ip_tos;
		break;
	    }
#endif
#ifdef INET6
	case AF_INET6:
	    {
		struct ip6_hdr *ip6;
		proto = IPPROTO_IPV6;
		if (m->m_len < sizeof(*ip6)) {
			m = m_pullup(m, sizeof(*ip6));
			if (!m)
				return ENOBUFS;
		}
		ip6 = mtod(m, struct ip6_hdr *);
		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
		break;
	    }
#endif
#if defined(__NetBSD__) && defined(ISO)
	case AF_ISO:
		proto = IPPROTO_EON;
		itos = 0;
		break;
#endif
	default:
#ifdef DEBUG
		printf("in6_gif_output: warning: unknown family %d passed\n",
			family);
#endif
		m_freem(m);
		return EAFNOSUPPORT;
	}
	
	/* prepend new IP header */
	M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
	if (m && m->m_len < sizeof(struct ip6_hdr))
		m = m_pullup(m, sizeof(struct ip6_hdr));
	if (m == NULL)
		return ENOBUFS;

	ip6 = mtod(m, struct ip6_hdr *);
	ip6->ip6_flow	= 0;
	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
	ip6->ip6_vfc	|= IPV6_VERSION;
	ip6->ip6_plen	= htons((u_short)m->m_pkthdr.len);
	ip6->ip6_nxt	= proto;
	ip6->ip6_hlim	= ip6_gif_hlim;
	ip6->ip6_src	= sin6_src->sin6_addr;
	/* bidirectional configured tunnel mode */